3.4.3.5. Reliability model proposed for all EEE families#

This section introduces all the models proposed for the different families. These models are mainly based on the models proposed in [NR_EEE_2].

The failure rates calculated with reliability.space are given directly in FITs (failure in time, correspong to failures per billion hours). As for the FIDES methodology, these FRs, if corresponding to modelling over several phases constituting a mission profile, are calendar lambdas, as explained in Section 3.4.3.2.1.

Note

For each family, a table presents the different subfamilies. In the remark column are the reference linked to the subfamily in the FIDES Expertool. This is just given as an information for users willing to model with that tool, in order to make sure that they consider the correct model.

3.4.3.5.1. Capacitors (family 01)#

Capacitors are classified as family 01 in EPPL [BR_EEE_9].

All capacitors used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method (in the 2009 version of FIDES but also in the 2021 version for information).

Table 3.4.19 Groups of capacitors.#
Groups of capacitors Models in FIDES Proposed models in FIDES Remark
2009 2021

01 Ceramic

02 Ceramic chip

10 Feedthrough

p135 p151

“Ceramic capacitor with defined temperature coefficient (Type 1)”

“Ceramic capacitor with non-defined temperature coefficient (Type 2) ”

ECCC_01

….

ECCC_08

03 Tantalum solid

04 Tantalum non-solid

p140 p156 “Tantalum capacitor (solid or gel electrolyte)”

ECTC_08

(ECTC_04 .. 06)

ECTC_07

(ECTC_01..03)

05 Plastic metallized No p158 “Plastic film capacitor”

ECFC_01

…..

ECFC_05

06 Glass

07 Mica

No No NA - No longer used in space applications NA
09 Aluminium Yes p154

“Aluminium liquid electrolyte capacitor”, “Aluminium solid electrolyte capacitor”

Not used in space applications

ECAC_01

ECAC_02

11 Semiconductors No No

“Low power transistors, Silicon MOS < 5W”

Addressed in section

ECDS_19

Note

Type 1 and Type 2 correspond to the two types of ceramic capacitors, Type 1 ceramic capacitors are ceramic capacitors with high stability and low losses compensating the influence of temperature in resonant circuit applications. Their dielectric is paraelectric, Type 2 corresponds to ceramic capacitors with high volumetric efficiency for buffer, by-pass and coupling applications. Their dielectric is ferroelectric.

Here is the generic formula used in FIDES for capacitors:

Equation

(3.4.32)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{LF}}\]

with:

  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered. For Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

3.4.3.5.1.1. Ceramic Capacitors (01 & 02 subfamilies) & Feedthrough (10 subfamily)#

The following table lists the 8 categories that cover the Ceramic Capacitor subfamily based on the CV calculation.

Table 3.4.20 Detail for ceramic capacitors#
ECCC - Ceramic Capacitor
ECCC_01 Ceramic Capacitor Type I - Low CV
ECCC_02 Ceramic Capacitor Type I - Medium
ECCC_03 Ceramic Capacitor Type I - High CV
ECCC_04 Ceramic Capacitor Type II - Low CV
ECCC_05 Ceramic Capacitor Type II - Medium CV
ECCC_06 Ceramic Capacitor Type II - High CV
ECCC_07 Ceramic Capacitor Type II Polymer terminations - Low CV
ECCC_08 Ceramic Capacitor Type II Polymer terminations - High/Medium CV

Note

For the special case of HFRF capacitors, the choice is given in the table hereafter:

Table 3.4.21 Detail for HFRF capacitors#
HFHC - HFRF Capacitor
HFHC_01 HFRF Capacitor Type I - Low CV
HFHC_02 HFRF Capacitor Type I - Medium CV
HFHC_03 HFRF Capacitor Type I - High CV

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.33)#\[\lambda_{\text{Physical}} = \lambda_{0_{\text{capacitor}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

With:

  • \(\lambda_{0_{\text{capacitor}}}\) : Base failure rate for one group of capacitor

  • \(\Pi_{\text{Thermo-electrical}}\) : Thermo-electrical factor

  • \(\Pi_{\text{TCy}}\) : Cycling factor

  • \(\Pi_{\text{Mechanical}}\) : Mechanical factor

  • \(\Pi_{\text{induced}}\) : Induced factor

Physical stresses for ceramic capacitors:

Equation

(3.4.34)#\[\Pi_{\text{Thermal}} = \gamma_{\text{TH}_{\text{EL}}} \cdot \left( \frac{1}{S_{\text{reference}}} \cdot \frac{V_{\text{applied}}}{V_{\text{rated}}} \right)^{3} \cdot \exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{\text{board}_{\text{ref}}} + \text{ΔT}} \right) \right\rbrack\]
(3.4.35)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{\text{cy}_{\text{phase}}}}{t_{\text{phase}}} \right) \cdot \left( \frac{\min\left( \theta_{\text{cy}},2 \right)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\Delta T_{\text{cycling}}}{20} \right)^{1.9} \cdot \exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{\max_{\text{cycling}}}} \right) \right\rbrack\]
(3.4.36)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

With \(\lambda_{0_{\text{capacitor}}}\), \(E_{a}\), \(S_{\text{reference}}\), \(\gamma_{\text{TCy}}\), \(\gamma_{\text{Mech}}\), \(\gamma_{\text{TH}_{\text{EL}}}\) given in Table 3.4.22.

Table 3.4.22 Details of parameters for ceramic capacitors#

Description

Ref

\(\lambda_{0_{\text{capacitor}}}\)

\(E_{a}\)

\(S_{\text{reference}}\)

\(\gamma_{\text{TH}_{\text{EL}}}\)

\(\gamma_{\text{TCy}}\)

\(\gamma_{\text{Mech}}\)

Ceramic Capacitor Type I - Low CV

ECCC_01

0.03

0.1

0.3

0.7

0.28

0.02

Ceramic Capacitor Type I - Medium CV

ECCC_02

0.05

0.1

0.3

0.7

0.28

0.02

Ceramic Capacitor Type I - High CV

ECCC_03

0.40

0.1

0.3

0.69

0.26

0.05

Ceramic Capacitor Type II - Low CV

ECCC_04

0.08

0.1

0.3

0.7

0.28

0.02

Ceramic Capacitor Type II - Medium CV

ECCC_05

0.15

0.1

0.3

0.7

0.28

0.02

Ceramic Capacitor Type II - High CV

ECCC_06

1.20

0.1

0.3

0.44

0.51

0.05

Ceramic Capacitor Type II Polymer terminations - Low CV

ECCC_07

0.08

0.1

0.3

0.7

0.28

0.02

Ceramic Capacitor Type II Polymer terminations - High/Medium CV

ECCC_08

0.15

0.1

0.3

0.7

0.28

0.02

The CV factor mentioned in Table 3.4.20 corresponds to the Capacitance * Voltage Rated value of the component. The level is given in Table 3.4.23 This table differs from the one presented in FIDES 2009 (and presented for information in Annex B: Capacitors) in order to take into account the fact that the actual discrimination between high and medium levels attributed to the technological limits. This table is included in the FIDES 2021 version of the handbook.

Rule

This table is the one that needs to be applied for Space applications.

Note

Technological limit refers to the highest value for some given characteristics for a reference covering a range of values (e.g., if the CC0x0x family corresponds to components with a capacitance between 10pf and 10nF, then the 10nF component is considered as the technological limit for this reference).

Table 3.4.23 Definition of CV product for ceramic capacitors.#
CV product Type I Type II
Low CV product Less than 5.0x10-8V.F Less than 5.0x10-6V.F
Medium CV product

Between 5.0x10-8V.F and 1.0x10-6V.F

or Higher than 1.0x10-6V.F and not in technological limit

Between 5.0x10-6V.F and 1.0x10-4V.F

or Higher than 1.0x10-4V.F and not in technological limit

High CV product Higher than 1.0x10-6V.F and in technological limit Higher than 1.0x10-4V.F and in technological limit

Induced factor \(\Pi_{\text{induced}}\):

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.37)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]
  • \(\Pi_{\text{placement}\_ i}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3. Recommendation for the definition of parameter \(\Pi_{\text{placement}\_ i}\):

Table 3.4.24 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\)#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

  • \(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.25 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#
Criterion Description Levels Examples and comments Weight - POS
User type in the phase considered Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(\text{P}_{\text{os}}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

  • \(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

  • \(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) , presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.26 Coefficient of sensitivity for capacitors.#

Technologies

\(C_{\text{sensitivity}}\)

Ceramic capacitors

6.05

Note

For the 2021 issue of FIDES, the table has been updated, splitting the sensitivity between 5 categories instead of just one (Type I, Type II X5R, Type II X7R, Type II X5R polymer terminations, Type II X7R polymer terminations)

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.38)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.39)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\Pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.27 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for ceramic capacitors.#

Ceramic capacitors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: MIL-PRF-xxxx level T, MIL-PRF-xxxx level S, MIL-PRF-xxxx level R, ESCC 300x, NASDA-QTS-xxxx class I (JAXA-QTS-2040E)

Higher

3

Qualification according to one of the following standards: AEC Q200, MIL-PRF-xxx level P, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards, qualification according to approved CECC standards.

Equivalent

2

Qualification according to one of the following MIL-PRF-xxxx level M, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much lower

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.

3.4.3.5.1.2. Tantalum Capacitors (03 & 04 families)#

The following table lists the 6 categories that cover the Tantalum Capacitor subfamily

Table 3.4.28 Detail for tantalum capacitors#
ECTC - Tantalum capacitors
Wet tantalum capacitor silver case sealed by elastomer ECTC_01
Wet tantalum capacitor silver case sealed by glass beads ECTC_02
Wet tantalum capacitor beads tantalum case sealed by glass beads ECTC_03
Dry tantalum capacitor drop packaging ECTC_04
Dry tantalum capacitor SMD packaging ECTC_05
Dry tantalum axial metal packaging ECTC_06

General model for the capacitors family:

Equation

(3.4.40)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{Film}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}}\]

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation \(\lambda_{\text{Physical}}\)

Equation

\[\lambda_{\text{Physical}} = \lambda_{0_{\text{capacitor}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

Refer to (3.4.33).

Physical stresses for tantalum capacitors:

Equation

(3.4.41)#\[\Pi_{\text{Thermal}} = \gamma_{TH\_ EL} \cdot \left( \frac{1}{S_{\text{reference}}} \cdot \frac{V_{\text{applied}}}{V_{\text{rated}}} \right)^{3} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]
(3.4.42)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\Delta T_{\text{cycling}}}{20} \right)^{1.9} \cdot exp \left \lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right \rbrack\]
(3.4.43)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

With \(\lambda_{0_{\text{capacitor}}}\), \(E_{a}\), \(S_{\text{reference}}\), \(\gamma_{\text{TCy}}\), \(\gamma_{\text{Mech}}\), \(\gamma_{\text{TH}_{\text{EL}}}\) given in Table 3.4.29.

Table 3.4.29 Groups of capacitors#
Description Ref λ0_capacitor Ea (eV) Sreference \(\gamma\)TH_El \(\gamma\)TCy \(\gamma\)Mech
Wet tantalum capacitor (ETCT_07)
Wet tantalum capacitor silver case sealed by elastomer ECTC_01 0.77 0.15 0.6 0.87 0.01 0.12
Wet tantalum capacitor silver case sealed by glass beads ECTC_02 0.33 0.15 0.6 0.81 0.01 0.18
Wet tantalum capacitor beads tantalum case sealed by glass beads ECTC_03 0.05 0.15 0.6 0.88 0.04 0.08
Solid tantalum capacitor (ETCT_08)
Dry tantalum capacitor drop packaging ECTC_04 1.09 0.15 0.4 0.86 0.12 0.02
Dry tantalum capacitor SMD packaging ECTC_05 0.54 0.15 0.4 0.84 0.14 0.02
Dry tantalum axial metal packaging ECTC_06 0.25 0.15 0.4 0.94 0.04 0.02

Induced factor \(\Pi_{\text{induced}}\):

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.44)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

See Section 3.4.3.5.1.1 for details.

The induced factor \(C_{\text{sensitivity}}\) is provided in the following table:

Table 3.4.30 Coefficient of sensitivity for capacitors.#

Technologies

\(C_{\text{sensitivity}}\)

Tantalum capacitors

6.95

Note

For the 2021 issue of FIDES, the value has been updated (to 7.43).

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.45)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.46)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\Pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.31 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for tantalum capacitors.#

tantalum capacitors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200, MIL-PRF-xxxx level T, MIL-PRF-xxxx level B, ESCC 300x, NASDA-QTS-xxxx class I (JAXA-QTS-2040E)

Higher

3

Qualification according to one of the following standards: MIL-PRF-xxxx level C, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards. Qualification according to approved CECC standards.

Equivalent

2

Qualification according to one of the following: MIL-PRF-xxxx level D, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much lower

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.

3.4.3.5.1.3. Plastic Metallized Capacitors (05 family)#

At the time of the FIDES 2009 release, no model existed for plastic films capacitors, but some companies subscribed for the development of such a model which is now included in the FIDES 2021 update.

The following table lists the 5 categories that cover the Plastic Metallized Capacitor subfamily.

Table 3.4.32 Detail for Plastic Metallized capacitors#
ECFC - Plastic Metallized capacitors
Polypropylene film capacitor (PP) ECFC_01
Polyethylene terephtalate film capacitor (PET) ECFC_02
Polyethylene naphtalate film capacitor (PEN) ECFC_03
Polyphenylene sulfide film capacitor (PPS) ECFC_04
Teflon film capacitor (PTFE) ECFC_05

General model for the capacitors family:

Equation

(3.4.47)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{Film}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}}\]

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation \(\lambda_{\text{Physical}}\)

Equation

\[\lambda_{\text{Physical}} = \lambda_{0_{\text{capacitor}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

Physical stresses for plastic film capacitors:

Equation

(3.4.48)#\[\Pi_{\text{Thermal}} = 0.18 \cdot \left( \frac{1}{S_{\text{reference}}} \cdot \frac{V_{\text{applied}}}{V_{\text{rated}}} \right)^{6} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]
(3.4.49)#\[\Pi_{\text{Tcy}} = 0.14 \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]
(3.4.50)#\[\Pi_{\text{Mechanical}} = 0.02 \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]
(3.4.51)#\[\Pi_{\text{RH}} = {0.66 \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)}^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

With \(\lambda_{0_{\text{capacitor}}}\), \(E_{a}\), \(S_{\text{reference}}\) given in the following table. All other parameters are issued from the mission profile.

Table 3.4.33 Parameters for physical stresses of plastic film capacitors.#
Type of plastic film capacitors λ0_capacitor Ea Sreference
Polypropylene film capacitor (PP) 0.02 0.65 0.3
Polyethylene terephtalate film capacitor (PET) 0.06 0.48 0.3
Polyethylene naphtalate film capacitor (PEN) 0.03 0.55 0.3
Polyphenylene sulfide film capacitor (PPS) 0.02 0.55 0.3
Teflon film capacitor (PTFE) 0.03 0.55 0.3

Calculation of \(\Pi_{\text{Film}}\) factor:

For plastic film capacitors: \(\Pi_{\text{Film}}\) factor is calculated from a questionnaire about the environmental conditions which have led to the choice of the plastic film capacitor.

Equation

(3.4.52)#\[\Pi_{\text{Film}} = e^{1.39 \cdot FILM\_ Grade}\]
(3.4.53)#\[FILM\_ Grade = \frac{\sum_{}^{}\text{Values in the following table}}{100}\]

Table 3.4.34 Factors influencing the \(\Pi_{\text{Film}}\) factor.#
Factors influencing FILM_Grade Value
1 Plastic film capacitor used in AC alternative voltage 50
Plastic film capacitor used in DC direct voltage 0
2 Plastic film capacitor used in environment with humidity rate higher than 90%HR without being specifically chosen for this environment 30
Plastic film capacitor used in environment with humidity rate higher than 90%HR and chosen for this environment 15
Plastic film capacitor used in environment with humidity rate comprise between 70%HR and 90%HR without being specifically chosen for this environment 15
Plastic film capacitor used in environment with humidity rate comprise between 70%HR and 90%HR and chosen for this environment 0
Plastic film capacitor used in environment with humidity rate lower than 70%HR 0
3 Plastic film capacitor not specifically developed for current application, not validated by the manufacturer and not validated by derogation. 20
Plastic film capacitor not specifically developed for current application but validated by the manufacturer 10
Plastic film capacitor specifically developed for current application 0

Induced factor \(\Pi_{\text{induced}}\):

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.54)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

See Section 3.4.3.5.1.1 for details.

The induced factor \(C_{\text{sensitivity}}\) is provided in the following table:

Table 3.4.35 Coefficient of sensitivity for capacitors.#

Technologies

\(C_{\text{sensitivity}}\)

Plastic film capacitors

6.05

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.55)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.56)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\Pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.36 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for plastic film capacitors.#

Plastic film capacitors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200, MIL-PRF-xxxx level T, MIL-PRF-xxxx level S, MIL-PRF-xxxx level R, ESCC 400x, NASDA-QTS-xxxx class I (JAXA-QTS-2050D)

Higher

3

Qualification according to one of the following standards: MIL-PRF-xxx level P, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards, qualification according to approved CECC standards.

Equivalent

2

Qualification according to MIL-PRF-xxxx level M, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much lower

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.

Summary for the Capacitors family 01

Section Component types Modifications and adaptations for space applications
01 Capacitors

Addition of the model for plastic film capacitors - FIDES 2021

Modification of the CV product for ceramic capacitors - FIDES 2021

Value of ΠFilm equal to 1 for all capacitors - FIDES 2021

3.4.3.5.2. Connectors (family 02)#

Connectors are classified as family 02 in EPPL [BR_EEE_9].

All connectors used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method (in the 2009 version of FIDES but also in the 2021 version for information).

Table 3.4.37 Groups of connectors.#
Groups of connectors Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Circular p158 p176 “Circular and rectangular connectors” ECCO_01
02 Rectangular p158 p176 “Circular and rectangular connectors” ECCO_01
03 PCB p158 p176 “Connectors for printed circuits (and similar)” ECCO_03
05 RF coaxial p158 p176 “Coaxial connector” ECCO_02
06 Glass fibre No No NA - No longer used in space applications NA
07 Microminiature No/Yes No/Yes “Circular and rectangular connectors” Not modelled directly in FIDES so the recommendation is to use the proposed model
08 RF filter No No NA - No longer used in space applications NA
09 Rack and panel No No NA - No longer used in space applications NA

is the generic formula used in FIDES for connectors:

Equation

(3.4.57)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{LF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.58)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{connector}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} + \Pi_{\text{Chemical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

With:

  • \(\lambda_{0_{\text{connector}}}\) : Base failure rate for one group of connector

  • \(\Pi_{\text{Thermal}}\) : Thermal factor

  • \(\Pi_{\text{TCy}}\) : Cycling factor

  • \(\Pi_{\text{Mechanical}}\) : Mechanical factor = 0 for space industry

  • \(\Pi_{\text{RH}}\) : Humidity factor = 0 for space industry

  • \(\Pi_{\text{Chemical}}\) : Chemical

  • \(\Pi_{\text{induced}}\) : Induced factor

Calculation of \(\lambda_{0_{\text{connector}}}\):

Equation

(3.4.59)#\[\lambda_{O\_ connector} = \lambda_{\text{Type}} \cdot \Pi_{\text{Transfer}} \cdot \Pi_{\text{Contact}} \cdot \Pi_{\text{Cycle}}\]

With:

  • \(\lambda_{\text{Type}}\) equals 0.05 for circular & rectangular connectors, 0.07 for coaxial and 0.1 for PCB connectors.

  • \(\Pi_{\text{Transfer}}\) depends on the soldering method and is defined by Table 3.4.38.

  • \(\Pi_{\text{Contact}}\) depends on the number of contacts (\(N_{\text{contact}}\)) of the connector: \(\pi_{\text{contact}} = \left( N_{\text{contact}} \right)^{0.5}\)

  • \(\Pi_{\text{Cycle}}\) depends on the annual number of cycles (one cycle = one connection + one disconnection): \(\pi_{\text{cycles}} = 0.2 \times \left( N_{annual\_ cycles} \right)^{0.25}\)

Table 3.4.38 Subtypes of connectors.#

Transfer Type

\(\Pi_{\text{Transfer}}\)

Insertion (press fit)

1

ECCO_05

Soldered (through)

6

ECCO_06

Soldered (SMD)

10

ECCO_07

Wrapping (braid)

3

ECCO_08

Wrapping (wire)

2

ECCO_09

Note

For space applications, where the number of cycles (mating/demating) per year is < 1, \(\Pi_{\text{Cycle}}\) = 0.2.

Physical stresses for connectors:

Equation

(3.4.60)#\[\Pi_{\text{Thermal}} = 0.58 \cdot exp\left\lbrack 11604 \cdot 0.1 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

Equation

(3.4.61)#\[\Pi_{\text{Tcy}} = 0.04 \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.62)#\[\Pi_{\text{Mechanical}} = 0.05 \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.63)#\[\Pi_{\text{RH}} = 0.13 \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.8 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

Equation

(3.4.64)#\[\Pi_{\text{Chemical}} = 0.2\]

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.65)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The value of Pi Placement for connectors is 1.

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table:

Table 3.4.39 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.40 Induced factor coefficient of sensitivity for connectors.#

Technologies

\(C_{\text{sensitivity}}\)

Connectors

4.40

Note

For the 2021 issue of FIDES, the value has been updated (to 3.13).

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.66)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.67)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.41 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for connectors.#

Connectors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: ESCC 340x level B, NASDA-QTS-xxxx class 1, MIL-DTL-xxxxx, JAXA-QTS-2060E, GSFC

Higher

3

Qualification according to one of the following standards: Telcordia GR1217-CORE, ARINC 600 and 80x (not space adapted), AECMA, SAE (39029)

Equivalent

2

Qualification according to one of the following standards: EIA, IEC, SAE, BS

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Note

In the 2021 issue of FIDES, a table has been added for gauges of circular sections.

Summary for the Connectors family 02

Section Component types Modifications and adaptations for space applications
02

Value of ΠCycle equal to 0.2

Value of ΠChemical equal to 0.2

3.4.3.5.3. Piezo electric devices (family 03)#

Piezo electric devices are classified as family 03 in the EPPL [BR_EEE_9]. Crystal/Quartz resonators/oscillators can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method.

Table 3.4.42 Groups of piezo electric devices.#
Groups of capacitors Models in FIDES Proposed models in FIDES Remark
2009 2022

01 Crystal resonator

p144 p162

“Quartz resonator (through HCxx type case)”

“Quartz resonator (surface mounted)”

“Quartz oscillator (through XO type case)”

“Quartz oscillator (surface mounted XO, MCSO type case)”

ECPZ_01

ECPZ_02

ECPZ_03

ECPZ_04

General model for the piezo electric devices family:

Equation

(3.4.68)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item.

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.69)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{piezoelectric}}} \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{Thermo\_ electrical} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

With:

  • \(\lambda_{0_{\text{piezoelectric}}}\) : Base failure rate for one group of piezoelectric

  • \(\Pi_{\text{Thermo-electric}}\) : Thermo-electric factor

  • \(\Pi_{\text{TCy}}\) : Cycling factor

  • \(\Pi_{\text{Mechanical}}\) : Mechanical factor = 0 for space industry

  • \(\Pi_{\text{RH}}\) : Humidity factor = 0 for space industry

  • \(\Pi_{\text{induced}}\) : Induced factor

\(\lambda_{0_{\text{piezoelectric}}}\) corresponds to the basic failure rate defined as follow within the mentioned groups:

Table 3.4.43 Basic failure rates for piezo electric devices.#

Component description

\(\lambda_{0_{\text{piezoelectric}}}\)

Oscillator surface, XO, MCSO case type

ECPZ_04

1.63

Oscillator through, XO case type

ECPZ_03

1.60

Resonator through, HCxx case type

ECPZ_01

0.82

Resonator surface mount

ECPZ_02

0.79

Physical stresses for piezo electric devices:

Equation

(3.4.70)#\[\Pi_{Thermo\_ electrical} = \gamma_{TH - EL} \cdot \Pi_{rating\_ TH\_ i} \cdot \Pi_{rating\_ EL\_ i}\]

\(\gamma_{TH - EL}\) depends on the type of piezo electrical devices.

Table 3.4.44 \(\gamma_{TH - EL}\) for piezo electric devices.#

Component description

\(\gamma_{TH - EL}\)

Oscillator surface, XO, MCSO case type

0.31

Oscillator through, XO case type

0.32

Resonator through, HCxx case type

0.16

Resonator surface mount

0.16

\(\Pi_{rating\_ TH\_ i}\) follows the rule:

  • \(\Pi_{rating\_ TH\_ i}\) =1 if \(T_{board\_ ref}\) + \(\Delta T\) < \(T_{max\_ manufacturer}\)- 40°C;

  • \(\Pi_{rating\_ TH\_ i}\) =5 if \(T_{board\_ ref}\) + \(\Delta T\)\(T_{max\_ manufacturer}\)- 40°C;

\(\Pi_{rating\_ EL\_ i}\) follows the rule:

  • \(\Pi_{rating\_ EL\_ i}\) =1 for resonators;

  • \(\Pi_{rating\_ EL\_ i}\) =1 for oscillators if \(I_{output}\) < 0.8·\(I_{max\_ output}\);

  • \(\Pi_{rating\_ EL\_ i}\) =5 for oscillators if \(I_{output}\) ≥ 0.8·\(I_{max\_ output}\).

All other parameters are issued from the mission profile.

Equation

(3.4.71)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(\gamma_{\text{TCy}}\) depends on the type of piezo electrical devices.

Table 3.4.45 \(\gamma_{\text{TCy}}\) for piezo electric devices.#

Component description

\(\gamma_{\text{TCy}}\)

Oscillator surface, XO, MCSO case type

0.53

Oscillator through, XO case type

0.42

Resonator through, HCxx case type

0.46

Resonator surface mount

0.59

All other parameters are issued from the mission profile.

Equation

(3.4.72)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(\gamma_{\text{Mech}}\) depends on the type of piezo electrical devices.

Table 3.4.46 \(\gamma_{\text{Mech}}\) for piezo electric devices.#

Component description

\(\gamma_{\text{Mech}}\)

Oscillator surface, XO, MCSO case type

0.07

Oscillator through, XO case type

0.14

Resonator through, HCxx case type

0.27

Resonator surface mount

0.15

All other parameters are issued from the mission profile.

Equation

(3.4.73)#\[\Pi_{\text{RH}} = \gamma_{\text{RH}} \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(\gamma_{\text{RH}}\) depends on the type of piezo electrical devices.

Table 3.4.47 \(\gamma_{\text{RH}}\) for piezo electric devices.#

Component description

\(\gamma_{\text{RH}}\)

Oscillator surface, XO, MCSO case type

0.09

Oscillator through, XO case type

0.12

Resonator through, HCxx case type

0.11

Resonator surface mount

0.10

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.74)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.48 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table:

Table 3.4.49 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.50 Induced factor coefficient of sensitivity for piezo electric devices.#

Technologies

\(C_{\text{sensitivity}}\)

Resonators

4.55

Quartz

8.10

Note

For the 2021 issue of FIDES, the value has been updated (respectively to 3.95 and 7.25).

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.75)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.76)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.51 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for piezoelectric components.#

Piezoelectric components: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200 (Resonator) MIL-PRF-38534 class K (oscillator), MIL-PRF-55310 class S (Oscillator), ESCC 3503 (oscillator)/3501 (resonator) or equivalent

Higher

3

Qualification according to one of the following standards: MIL-PRF-38534 class H, MIL-PRF-55310 class B

Equivalent

2

Qualification according to one of the following MIL-PRF-xxxx level M

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Crystal resonators family 03

Section Component types Modifications and adaptations for space applications
03 Piezolectric components

-

3.4.3.5.4. Diodes (family 04)#

General diodes and HF/RF diodes are classified as family 04 in EPPL [BR_EEE_9].

All diodes used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.52 Groups of diodes.#
Groups of diodes. Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Switching p120 p133 “Signal diodes up to 1A (PIN, Schottky, signal, varactor)” ECDS_10
02 Rectifier

p120

p120

p133

p133

“Rectifying diodes 1A to 3A”

“Rectifying diodes > 3A”

ECDS_11

ECDS_15

03 Voltage regulator

p120

p120

p133

p133

“Zener regulation diodes up to 1.5W”,

“Zener regulation diodes more than 1,5W”

ECDS_12

ECDS_16

04 Voltage reference / Zener

p120

p120

p133

p133

“Zener regulation diodes up to 1,5W”

“Zener regulation diodes more than 1.5W”

ECDS_12

ECDS_16

05 RF microwave Schottky (Si) p185 p211 “PIN, Schottky, Tunnel, varactor diodes (RF HF)” HFDI_01
06 Pin p185 p211 “PIN, Schottky, Tunnel, varactor diodes (RF HF)” HFDI_01
07 Hot carrier

p120

p185

p133

p211

“Signal diodes up to 1A (PIN, Schottky, signal, varactor)”

“PIN, Schottky, Tunnel, varactor diodes (RF HF)”

ECDS_10

HFDI_01

08 Transient suppression

p120

p120

p133

p133

“Protection diodes up to 3kW (in peak 10ms/100ms) (TVS)”

“Protection diodes more than 3kW (in peak 10ms/100ms) (TVS)”

ECDS_13

ECDS_17

10 High voltage rectifier No/Yes No/Yes Not usually used in space applications, no more present in the EPPL list but recommendation to use “Rectifying diodes > 3A” ECDS_15
11 Microwave varactor (GaAs) No/Yes No/Yes Not usually used in space applications, no more present in the EPPL list but recommendation to use “PIN, Schottky, Tunnel, varactor diodes (RF HF)” HFDI_01
12 Step recovery No No Not usually used in space applications, no more present in the EPPL and not modelled by FIDES 2009 NA
13 RF / microwave varactor (Si) p185 p211 “PIN, Schottky, Tunnel, varactor diodes (RF HF)” HFDI_01
14 Current regulator No No Not usually used in space applications, no more present in the EPPL and not modelled by FIDES 2009 NA
15 Microwave Schottky (GaAs) No/Yes No/Yes Not usually used in space applications, no more present in the EPPL but recommendation to use “PIN, Schottky, Tunnel, varactor diodes (RF HF)” HFDI_01
16 RF / microwave pin p185 p211 “PIN, Schottky, Tunnel, varactor diodes (RF HF)” HFDI_01
17 Microwave gunn (GaAs) No No Not usually used in space applications, no more present in the EPPL NA

3.4.3.5.4.1. HF RF Diodes (05, 06, 11, 13, 15 & 16 families)#

General model for the general diodes and the HF RF diodes family:

Equation

(3.4.77)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{ProcessRFHF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{ProcessRFHF}}\) the quality and technical control over the development, manufacturing and use process for the RFHF item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1 and HF/RF process factor \(\Pi_{\text{ProcessRFHF}}\) according to Section 3.4.3.3.5.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.78)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} + \lambda_{\text{OTCySolderjoints}} \cdot \Pi_{\text{TCySolderjoints}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

Basic failure rate \(\lambda_{\text{OTH}}\) is provided in the following table for RFHF diodes:

Table 3.4.53 Basic failure rates \(\lambda_{\text{OTH}}\) for diodes.#

Diode Type

Subcategory

\(\lambda_{\text{OTH}}\)

Remark

PIN, Schottky, tunnel, varactor (RFHF)

Si and SiGe discrete semiconductor circuit HFDI

0.0120

HFDI_01

PIN, Schottky, tunnel, varactor (RFHF)

Si and SiGe discrete semiconductor circuit HFDA

0.0120

HFDA_01

Basic failure rates \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{OMech}}\) are provided in the following table for the packages SODxx and TOxx specifically used in space applications:

Table 3.4.54 Basic failure rates \(\lambda_{0}\) for diodes.#
Case Equivalent name Description λOTCyCase λOTCySolderjoints λOMech
SOD80 Mini-MELF, DO213AA SMD, Hermetically sealed glass 0.00781 0.03905 0.00078
SOD87 MELF, DO213AB
TO18 TO71, TO72, SOT31, SOT18 Through hole, metal 0.0101 0.0505 0.00101
TO39 SOT5, TO254
TO52

\(\lambda_{\text{OTH}}\) is a fixed value given in another table, depending on the type of components.

Physical stresses for the general diodes and the RF HF diodes family:

Equation

(3.4.79)#\[\Pi_{\text{Thermal}} = \Pi_{\text{El}} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

Equation

(3.4.80)#\[\begin{split}\Pi_{\text{El}}= \begin{cases} \left( \frac{V_{\text{applied}}}{V_{\text{rated}}} \right)^{2.4} &\text{if} \frac{V_{\text{applied}}}{V_{\text{rated}}} > 0.3 \\ 0.056 &\text{if} \frac{V_{\text{applied}}}{V_{\text{rated}}} \leq 0.3. \end{cases}\end{split}\]

for signal diodes up to 1A (PIN, Schottky, signal, varactor) and for HF/RF diodes

for all other diodes, \(\Pi_{\text{El}}\) = 1.

Equation

(3.4.81)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.82)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ annual}}{t_{\text{annual}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.83)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.84)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.55 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.56 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.57 Induced factor coefficient of sensitivity for piezo electric devices.#

Technologies

\(C_{\text{sensitivity}}\)

Si and Ge RF diodes

6.30

GaAs RF diodes

7.40

Note

For the 2021 issue of FIDES, these values have not been updated, except for the addition of data for GaN diodes (6.9).

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.85)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.86)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.58 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for diodes.#

Diodes: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q101, AEC Q102, MIL-PRF-19500 JANS, ESCC 5000, ESCC 5010 level B, NASDA-QTS-xxxx class I, JAXA-QTS Class I (NASDA-QTS-2030)

Higher

3

Qualification according to one of the following standards: MIL-PRF-19500 JANTX or JANTXV, ESCC 5010 level C, NASDA-QTS-xxxx class II, JAXA-QTS Class II

Equivalent

2

Qualification according to one of the following standards: MIL-PRF-19500 JAN or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

3.4.3.5.4.2. Other Diodes (01, 02, 03, 04, 07, 08, 10 families)#

General model for the general diodes family:

Equation

(3.4.87)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{ProcessRFHF}}\]

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.88)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} \lambda_{\text{OTH}} \cdot \Pi_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

Basic failure rates \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{OMech}}\) are provided in the following table for the packages SODxx and TOxx specifically used in space applications:

Table 3.4.59 Basic failure rates \(\lambda_{0}\) for diodes.#
Case Equivalent name Description λOTCyCase λOTCySolderjoints λOMech
SOD80 Mini-MELF, DO213AA SMD, Hermetically sealed glass 0.00781 0.03905 0.00078
SOD87 MELF, DO213AB
TO18 TO71, TO72, SOT31, SOT18 Through hole, metal 0.0101 0.0505 0.00101
TO39 SOT5, TO254
TO52

\(\lambda_{\text{OTH}}\) is a fixed value given in another table, depending on the type of components.

Table 3.4.60 Basic failure rates \(\lambda_{\text{OTH}}\) for diodes.#

Type

Groups

\(\lambda_{\text{OTH}}\)

Power diodes – Protection diodes >3kW

8b

1.4980

Power diodes – Thyristors, triacs > 3A

0.1976

Power diodes – Rectifying diodes >3A

2b/10

0.1574

Power diodes – Zener regulation diodes >1.5W

3b/4b

0.0954

Low power diodes – Protection diodes <3kW

8a

0.0210

Low power diodes – rectifying diodes >1A, <3A

2a

0.0100

Low power diodes – Zener regulation diodes <1.5W

3a/4a

0.0080

Low power diodes – signal diodes <1A

1

0.0044

Physical stresses for the general diodes and the RF HF diodes family:

Equation

(3.4.89)#\[\Pi_{\text{Thermal}} = \Pi_{\text{El}} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

Equation

(3.4.90)#\[\begin{split}\Pi_{\text{El}} = \left\{ \begin{matrix} \left( \frac{V_{\text{applied}}}{V_{\text{rated}}} \right)^{2.4}\ \mathrm{\text{if}}\ \frac{V_{\text{applied}}}{V_{\text{rated}}} > 0.3 \\ \\ 0.056\ \mathrm{\text{if}}\ \frac{V_{\text{applied}}}{V_{\text{rated}}} \leq 0.3 \\ \end{matrix} \right.\ \end{split}\]

for signal diodes up to 1A (PIN, Schottky, signal, varactor) and for HF/RF diodes

for all other diodes, \(\Pi_{\text{El}}\) = 1.

Equation

(3.4.91)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.92)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ annual}}{t_{\text{annual}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.93)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.94)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.61 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.62 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.63 Induced factor coefficient of sensitivity for piezo electric devices.#

Technologies

\(C_{\text{sensitivity}}\)

Regular diodes

5.20

Note

For the 2021 issue of FIDES, the value has been updated (to 6.30).

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.95)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.96)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.64 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for diodes.#

Diodes: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q101, AEC Q102, MIL-PRF-19500 JANS, ESCC 5000, ESCC 5010 level B, NASDA-QTS-xxxx class I, JAXA-QTS Class I (NASDA-QTS-2030)

Higher

3

Qualification according to one of the following standards: MIL-PRF-19500 JANTX or JANTXV, ESCC 5010 level C, NASDA-QTS-xxxx class II, JAXA-QTS Class II

Equivalent

2

Qualification according to one of the following standards: MIL-PRF-19500 JAN or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Diodes family 04

Section Component types Modifications and adaptations for space applications
04 Diodes

Consideration of packages SODxx and TOxx only

Removal of the humidity stress ΠRH

3.4.3.5.5. Filters (family 05)#

Filters are classified as family 05 in EPPL [BR_EEE_9].

The HF/RF filters used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.65 Groups of filters.#
Groups of filters Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Feedthrough p188 p214

“Fixed passive components for microwaves: Attenuator, load (50 Ohm), filter, power divider (combiner, splitter)”

“Variable passive components for microwaves: Variable attenuator, tuneable filter”,

“Passive components with ferrites for microwaves, circulator, isolator, phase shifter”

HFOT_01

HFOT_02

HFOT_03

Surface Acoustic Wave p188 p214

“Fixed passive components for microwaves: Attenuator, load (50 Ohm), filter, power divider (combiner, splitter)”

Note: Model “Passive components for microwaves: Surface wave filters” HFOT_04 is not adequate for space applications

HFOT_01

General model for the filters family:

Equation

(3.4.97)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{ProcessRFHF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{ProcessRFHF}}\)

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1 and RF/HF process factor \(\Pi_{\text{ProcessRFHF}}\) according to Section 3.4.3.3.5. .

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.98)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{PassiveRFHF}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

\(\lambda_{O_{\text{PassiveRFHF}}}\) corresponds to the basic failure rate defined for sub-groups within the mentioned groups:

  • For attenuator, load (50Ω), filter, power divider (combiner, splitter) and surface acoustic wave filter, the value is equal to 0.5;

  • For variable attenuator, tuneable filter, circulator, isolator and phase shifter, the value is equal to 1.0.

Physical stresses for the fuses family:

Equation

(3.4.99)#\[\Pi_{\text{Thermal}} = \eta \cdot 0.01 \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.15eV;

η is the duty cycle during the phase.

All other parameters are issued from the mission profile.

Equation

(3.4.100)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack \]

\(\gamma_{\text{TCy}}\) depends on the type of filters:

  • For circulator, isolator, phase shifter, the value is equal to 0.69;

  • For all other filters, the value is equal to 0.67.

All other parameters are issued from the mission profile.

Equation

(3.4.101)#\[\Pi_{\text{Mechanical}} = 0.30 \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5} \]

All parameters are issued from the mission profile.

Equation

(3.4.102)#\[\Pi_{\text{RH}} = {\gamma_{\text{RH}} \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)}^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack \]

All other parameters are issued from the mission profile.

Table 3.4.66 Basic failure rates \(\lambda_{0}\) for filters.#

Description of the component

\(\lambda_{0\_ PassiveHFRF}\)

\(\gamma_{TH\_ EL}\)

\(\gamma_{TCy}\)

\(\gamma_{Mech}\)

\(\gamma_{RH}\)

“Fixed passive components for microwaves: Attenuator, load (50 Ohm), filter, power divider (combiner, splitter)”

0.5

0.01

0.67

0.30

0.02

“Variable passive components for microwaves: Variable attenuator, tuneable filter”

1

0.01

0.67

0.30

0.02

“Passive components with ferrites for microwaves, circulator, isolator, phase shifter”

1

0.01

0.69

0.30

0

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.103)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.67 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.68 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.69 Induced factor coefficient of sensitivity for filters.#

Technologies

\(C_{\text{sensitivity}}\)

All filters

2.60

Note

For the 2021 issue of FIDES, this value has been updated to 2.40.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.104)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.105)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.70 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for filters.#

Filters: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q100, MIL-PRF-38535 class V/Y, MIL-PRF-38510 class S, ESCC 90xx, NASDA-QTS-xxxx classe I, NPSL NASA level 1

Higher

3

Qualification according to one of the following standards: MIL-PRF-38535 class Q, MIL-PRF-38535 class M, MIL-PRF-38535 class N, MIL-PRF-38510 class B, NASDA-QTSxxxx class II, NPSL NASA levels 2 and 3

Equivalent

2

Qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Filters family 06

Section Component types Modifications and adaptations for space applications
05 Filters

Classification of Irated according to the standards IEC 60127-1 and UL 248-14

Value of ΠChi equal to 0.6

3.4.3.5.6. Fuses (family 06)#

Fuses are classified as family 06 in EPPL [BR_EEE_9]. All fuses used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.71 Groups of fuses.#
Groups of fuses. Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Fuse/td> p133 p149 “Fuse” ECFU

General model for the fuses family:

Equation

(3.4.106)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.107)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{fuse}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} + \Pi_{\text{Chi}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

Basic failure rate \(\lambda_{O_{\text{fuse}}}\) is equal to 0.5 for all fuses.

Physical stresses for the fuses family:

Equation

(3.4.108)#\[\Pi_{\text{Thermal}} = 0.13 \cdot \left( \frac{1}{0.8} \cdot \frac{I_{\text{applied}}}{I_{\text{rated}}} \right)^{1.5} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.15eV;

\(I_{\text{applied}}\) is the current in the fuse during the considered phase

\(I_{\text{rated}}\) is the rated current in the fuse without opening for an ambient temperature of 20°C. This value is equal to:

  • rated current for fuses following standard IEC 60127-1 [BR_EEE_4]

  • 75% of rated current for fuses following standard UL 248-14 [BR_EEE_24]

Equation

(3.4.109)#\[\Pi_{\text{Tcy}} = 0.51 \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\ \]

Equation

(3.4.110)#\[\Pi_{\text{Mechanical}} = 0.06 \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.111)#\[\Pi_{\text{RH}} = 0.24 \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.8 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

As the chemical stresses are low for space applications, the value \(\Pi_{\text{Chi}}\) should be equal to 0.6.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.112)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.72 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.73 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.74 Induced factor coefficient of sensitivity for fuses.#

Technologies

\(C_{\text{sensitivity}}\)

Fuses

5.80

Note

For the 2021 issue of FIDES, this value has been updated to 5.90.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.113)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.114)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.75 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for fuses.#

Diodes: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: ESCC 4008, MIL-PRF-23419/08/12 or equivalent

Higher

3

Qualification according to one of the following standards: IEC 60127 or equivalent

Equivalent

2

Qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Fuses family 06

Section Component types Modifications and adaptations for space applications
06 Fuses

Classification of Irated according to the standards IEC 60127-1 and UL 248-14

Value of ΠChi equal to 0.6

3.4.3.5.7. Inductors (family 07)#

Inductors are classified as family 07 in EPPL [BR_EEE_9].

All inductors used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.76 Groups of inductors.#
Groups of inductors. Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 RF coils

p142

p142

p181

p160

p160

p199

“Low current wirewound inductor”

“High current (or power) wirewound inductor”

“HF RF inductors”

ECIN_01

ECIN_02

HFHI

02 Cores No/Yes No/Yes Not usually used in space applications, no more present in the EPPL but recommendation to use “Multi-layer inductor” ECIN_03
03 Chip

p142

p142

p142

p160

p160

p160

“Low current wirewound inductor”,

“High current (or power) wirewound inductor”,

“Multi-layer inductor”

ECIN_01

ECIN_02

ECIN_03

Ferrite switch No/Yes No/Yes “Low current wirewound inductor” for EEE part only ECIN_01

Note

Core means coil without winding.

General model for the inductors family:

Equation

(3.4.115)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.116)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{Magnetic}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{Thermo\_ electrical} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

\(\lambda_{O_{\text{Magnetic}}}\) corresponds to the basic failure rate defined for sub-groups within the mentioned groups:

  • For low current wirewound inductors, \(\lambda_{O_{\text{Magnetic}}}\)is equal to 0.025;

  • For high current (or power) wirewound inductors and multi-layer inductors, \(\lambda_{O_{\text{Magnetic}}}\) is equal to 0.05.

Physical stresses for the inductors family:

Equation

(3.4.117)#\[\Pi_{Thermo - electrical} = \gamma_{TH\_ EL} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.15eV;

\(\gamma_{TH\_ EL}\) depends on the type of inductors:

  • For low current wirewound inductors, \(\gamma_{TH\_ EL}\) is equal to 0.01;

  • For high current (or power) wirewound inductors, \(\gamma_{TH\_ EL}\) is equal to 0.09;

  • For multi-layer inductors, \(\gamma_{TH\_ EL}\) is equal to 0.71.

All other parameters are issued from the mission profile.

Equation

(3.4.118)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(\Pi_{\text{Tcy}}\) depends on the type of inductors:

  • For low current wirewound inductors,\(\Pi_{\text{Tcy}}\) is equal to 0.73;

  • For high current (or power) wirewound inductors, \(\Pi_{\text{Tcy}}\) is equal to 0.79;

  • For multi-layer inductors, \(\Pi_{\text{Tcy}}\) is equal to 0.28.

All other parameters are issued from the mission profile

Equation

(3.4.119)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(\gamma_{\text{Mech}}\) depends on the type of inductors:

  • For low current wirewound inductors, \(\gamma_{\text{Mech}}\) is equal to 0.26;

  • For high current (or power) wirewound inductors, \(\gamma_{\text{Mech}}\) is equal to 0.12;

  • For multi-layer inductors, \(\gamma_{\text{Mech}}\) is equal to 0.01.

All other parameters are issued from the mission profile.

Table 3.4.77 Basic failure rates \(\lambda_{0}\) for inductors.#

Description of the component

\(\lambda_{0\_ \text{mag}}\)

\(\gamma_{TH\_ EL}\)

\(\gamma_{TCy}\)

\(\gamma_{Mech}\)

\(\Delta Τ \text{(°C)}\)

“Low current wirewound inductor”

0.025

0.01

0.73

0.26

10

“High current (or power) wirewound inductor”

0.05

0.09

0.79

0.12

30

“Multi-layer inductor”

0.05

0.71

0.28

0.01

10

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.120)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.78 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.79 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.80 Induced factor coefficient of sensitivity for fuses.#

Technologies

\(C_{\text{sensitivity}}\)

Low current wirewound inductors

4.05

High current (or power) wirewound inductors

8.05

Multi-layer inductors

4.40

Note

For the 2021 issue of FIDES, these values have been updated to respectively 4.73, 6.58 and 4.30.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.121)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.122)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.81 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for inductors.#

Diodes: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200, MIL-STD-981 class S, MIL-PRF-xxx level T, ESCC 320x, NASDA-QTS-xxxx class I

Higher

3

Qualification according to one of the following standards: MIL-STD-981 class B, MIL-PRF-xxx level M, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards, qualification according to approved CECC standards.

Equivalent

2

Qualification according to one of the following MIL-PRF-xxxx level C, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Inductors family 06

Section Component types Modifications and adaptations for space applications
07 Inductors

-

3.4.3.5.8. Integrated Circuits (Family 08)#

Integrated circuits are classified as family 08 in EPPL [BR_EEE_9].

All integrated circuits used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.82 Groups of integrated circuits.#
Groups of integrated circuits Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
10 Microprocessor / Microcontroller / Peripheral p111 p123 “Microprocessor, Microcontroller, DSP” ECIC_59
20 Memory SRAM p111 p123 “SRAM” ECIC_61
21 Memory DRAM/SDRAM p111 p123 No more present in the EPPL list but recommendation to use “DRAM” ECIC_62
22 Memory PROM p111 p123 Not used in space applications & no more present in the EPPL NA
23 Memory EPROM p111 p123 No more present in the EPPL but recommendation to use “Flash, EEPROM, EPROM” ECIC_60
24 Memory EEPROM p111 p123 No more present in the EPPL but recommendation to use “Flash, EEPROM, EPROM” ECIC_60
30 Programmable Logic p111 p123 No more present in the EPPL but recommendation to use “FPGA, CPLD, FPGA Antifuse, PAL” ECIC_58
40 ASIC Technologies Digital p117 p130

ASIC model

“MOS Silicon, Digital ASIC, simple function”,

“MOS Silicon, Digital ASIC, complex function”,

“Silicon Bipolar, BICMOS Digital ASIC”

ECAS

ECAS_01

ECAS_02

ECAS_04

41 ASIC Technologies Linear p117 p130

No more present in the EPPL but recommendation to use ASIC model

“Silicon bipolar, BICMOS, Mixed, analogue ASIC”

ECAS_05
42 ASIC Technologies Mixed Analog / Digital p117 p130

No more present in the EPPL but recommendation to use ASIC model

“MOS silicon, Analogue, mixed ASIC”,

“Silicon bipolar, BICMOS, Mixed, analogue ASIC”

ECAS_03

ECAS_05

50 Linear Operational Amplifier p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
51 Linear Sample And Hold Amplifier p111 p123 No more present in the EPPL but recommendation to use “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
52 Linear Voltage Reference / Regulator p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
53 Linear Voltage Comparator p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
54 Linear Switching Regulator p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
55 Linear Line Driver p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
56 Linear Line Receiver p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
57 Linear Timer p111 p123 No more present in the EPPL list but recommendation to use “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
58 Linear Multiplier p111 p123 No more present in the EPPL list but recommendation to use “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
59 Linear Switches p111 p123 No more present in the EPPL list but recommendation to use “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
60 Linear Multiplexers / Demultiplexer p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
61 Linear Analog To Digital Converter p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
62 Linear Digital To Analog Converter p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
69 Linear Other Functions p111 p123 “Analogue and hybrid circuit (MOS, bipolar, BiCMOS)” ECIS_58
80 Logic Families p111 p123 “Digital circuit (MOS, bipolar, BiCMOS) ECIC_63
95 Microwave Monolithic Integrated Circuits (MMIC) 182 208

RF HF integrated circuits models

“Si, SiGe integrated circuit”

Si RF and HF (MOS) analogue circuit (power amplifier)

Si, SiGe Analogue and mixed circuit (MOS, Bipolar, BiCMOS, MOSFET, PHEMT, HBT) including RF and HF

Si, SiGe RF and HF digital circuit (MOS, bipolar BiCMOS)

“GaAs integrated circuit”

GaAs, RF and HF analogue circuit (power amplifier)

GaAs Analogue and mixed circuit (MOS, Bipolar, BiCMOS, MOSFET, PHEMT, HBT) including RF and HF

“GaN integrated circuit”*

HFSI

HFSI-02

HFSI_03

HFSI_04

HFAS

HFAS_01

HFAS_03

TBD 2021

Note *

In the 2021 issue of FIDES, a GaN MMIC model has been included. The detail is provided in 4.4.2.3, as it has not yet been assessed and is just a proposition for the user.

3.4.3.5.8.1. MMIC (95 family)#

General model for the HF/RF ICs:

Equation

(3.4.123)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{ProcessHFRF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{ProcessHFRF}}\) the quality and technical control over the development, manufacturing and use process for the RFHF item

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.124)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ {+ \lambda_{\text{ORH}} \cdot \Pi}_{\text{RH}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

\(\lambda_{\text{OTH}}\) is a fixed value given in the following table, depending on the type of components.

Table 3.4.83 Basic failure rates \(\lambda_{\text{OTH}}\) for integrated circuits.#

Type

Groups

\(\lambda_{\text{OTH}}\)

Si, Ge Integrated Circuit

Si RF and HF (MOS) analogue circuit (power amplifier)

0.53

Si, SiGe Analogue and mixed circuit (MOS, Bipolar, BiCMOS, MOSFET, PHEMT, HBT) including RF and HF

0.19

Si, SiGe RF and digital circuit (MOS, bipolar BiCMOS)

0.04

GaAs Integrated Circuit

GaAs, RF and HF analogue circuit (power amplifier)

0.70*

GaAs Analogue and mixed circuit (MOS, Bipolar, BiCMOS, MOSFET, PHEMT, HBT) including RF and HF

0.19

Note *

\(\lambda_{\text{OTH}}\) for Power HF/RF has been updated in the 2021 issue of the FIDES guide to 0.3756.

The basic failure rates \(\lambda_{\text{ORH}}\), \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) are calculated through two constants a and b considering the type of package and the number of pins. The formula to apply is:

Equation

(3.4.125)#\[\lambda_{0_{\text{constraint}}} = exp\left( - a \right) \cdot {N_{p}}^{b}\]

All packages have been split into the following six categories:

  • Plastic PTH;

  • Ceramic PTH;

  • Plastic SMD with leads;

  • Plastic SMD without leads;

  • Ceramic SMD with leads;

  • Ceramic SMD without leads.

Table 3.4.84 Families of packages for plastic PTH.#

Typical name

Description

SDIP

Skinny Dual In Line Package

ZIP

Zig-zag In Line Package

QIP

Quadruple In Line Package

PGA

Pin grid array

SIP, SIPP

Single In Line Package

Table 3.4.85 Families of packages for ceramic PTH.#

Typical name

Description

CERDIP, CDIP, sidebraze

Ceramic dual in line package

CPGA

Ceramic pin grid array

PDIP, TO116

Plastic dual in line package

Table 3.4.86 Families of packages for plastic SMD with leads.#

Typical name

Description

PQFP

Plastic quad flatpack, L lead

SQFP, TQFP, VQFP, LQFP, HLQFP

Plastic shrink quad flatpack, L lead Plastic thin quad flatpack, L lead

Power QFP (RQFP, HQFP, PowerQuad, EdQuad…)

Plastic quad flatpack with heat shink, L lead

BQFP

Bumpered quad flatpack, L lead

BQFPH

Bumpered quad flatpack with heat spreader, L lead

PLCC

Plastic leaded chip carrier, J lead

SOJ

Plastic small outlines, J-lead

SO, SOP, SOL, SOIC, SOW

Plastic small outlines, L lead

TSOP I

Thin small outlines, leads on small edges, L lead

TSOP II

Thin small outlines, leads on long edges, L lead

SSOP, VSOP, QSOP, VSSOP

Plastic shrink (pitch) small outlines, L lead

TSSOP, MSOP, µSOP, µMAX, TVSOP

Thin shrink small outlines, L lead

HSSOP, HVSSOP, HTSSOP

Thermally Enhanced SSOP

ePad, TSSOP, MSOP, SOIC, SSOP, PSOP

exposed TSSOP/MSOP/SOIC/SSOP

CGA, LGA

Column Grid Array

HSOP

Heat Sink Enhanced SOP

Table 3.4.87 Families of packages for plastic SMD with leads.#

Typical name

Description

PBGA WLP 0.3mm

Plastic ball grid array with solder ball pitch = 0.30 mm

PBGA CSP BT 0.8 et 0.75mm

Plastic ball grid array with solder ball pitch = 0.8 et 0.75 mm

PBGA flex 0.8mm

Plastic ball grid array with solder ball pitch = 0.8

PBGA BT 1.00mm

Plastic ball grid array with solder ball pitch = 1.00 mm

PBGA 1.27mm

Plastic ball grid array with solder ball pitch = 1.27 mm

PBGA 1.5mm

Plastic ball grid array with solder ball pitch = 1.5 mm

FPBGA

Fine pitch BGA

FCPBGA

Flip chip plastic BGA

Power BGA (TBGA, SBGA …)

Tape BGABGA, PBGA with heat sink, die top down pitch=1.27mm Super BGA, PBGA with heat sink, die top down pitch=1.27mm

MAPBGA

Moulded Array Process Ball Grid

QFN, aQFN, DFN, MLF, LLP, ODFN, WQFN, VQFN, X2QFN

Quad flat no lead

SON, USON, VSON, WSON, X2SON

Small Outline No Lead

TEPBGA

Thermally Enhanced Plastic Ball Grid Array

Other CSP

Customized leadframe-based CSP

Other CSP

Flexible substrate-based CSP

Other CSP

Rigid substrate-based CSP

Other CSP

Micro CSP

PSvfBGA

Package Stackable Very Thin Fine Pitch BGA (pop)

PSfcCSP

Package Stackable Flip Chip Chip Scale Package (pop)

TMV, SV

Through Mold Via (POP)

WL-CSP, WLP, WLB, WCSP, DSBGA

Wafer-level chip scale package

WLCSP+

Protected Wafer Level Chip Scale Package

WLFO, eWLB

Wafer Level Fan-Out

CABGA, LBGA

ChipArray BGA

CTBGA TFBGA

Thin ChipArray BGA

CVBGA, VFBGA

Very thin ChipArray BGA

Table 3.4.88 Families of packages for plastic SMD with leads.#

Typical name

Description

CERPACK

Ceramic Package

CQFP, Cerquad

Ceramic quad flatpack

CI CGA

Ceramic land GA + interposer, Ceramic column GA

CCGA, CLGA

Ceramic Column Grid Array

Table 3.4.89 Families of packages for plastic SMD with leads.#

Typical name

Description

FCBGA

Flip chip BGA

CBGA

Ceramic ball grid array

J-CLCC

J-lead Ceramic leaded chip carrier

CLCC

Ceramic leadless chip carrier

For specific or complex packages, the general model for Hybrids and Multi Chip Modules should be used.

For each stress \(\lambda_{\text{ORH}}\), \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) corresponding to the stress due to humidity, thermal cycling, thermal cycling of solder joints and mechanical stress, the recommendation for the parameters a and b for estimating the reliability of packages is slightly different according to the number of leads of the components.

For components with 0 to 256 leads, the recommendation for the parameters a and b is the following:

Table 3.4.90 Parameters a and b for components with 0 to 256 leads.#
Family λ0RH λ0TcyCase λ0TcySolderjoints λ0Mech
a b a b a b a b
Plastic PTH 5.88 0.94 9.85 1.35 8.24 1.35 12.85 1.35
Ceramic PTH 0.00 0.00 6.77 1.35 4.47 1.35 7.69 1.35
Plastic SMD with leads 8.48 1.47 12.81 1.92 9.81 1.92 15.20 1.92
Plastic SMD without leads 8.97 1.14 11.20 1.21 7.90 1.14 11.12 1.21
Ceramic SMD with leads 0.00 0.00 12.41 1.46 10.80 1.46 14.02 1.46
Ceramic SMD without leads 0.00 0.00 8.07 0.93 5.42 0.93 8.53 0.93

For components with more than 256 leads, the recommendation for the parameters a and b is the following:

Table 3.4.91 Parameters a and b for components with more than 256 leads.#
Family λ0RH λ0TcyCase λ0TcySolderjoints λ0Mech
a b a b a b a b
Ceramic PTH 0.00 0.00 8.07 0.93 4.85 0.93 7.85 0.93
Plastic SMD with leads 12.66 2.08 13.76 1.71 11.46 1.71 15.37 1.71
Plastic SMD without leads 8.38 1.20 12.25 1.32 9.09 1.32 12.78 1.32
Ceramic SMD with leads 0.00 0.00 12.09 1.59 12.28 1.66 12.11 1.66
Ceramic SMD without leads 0.00 0.00 15.37 1.87 11.68 1.87 14.68 1.87

Note

In the 2021 issue of FIDES, some evolution concerning the inclusing of underfill has been added. Hence, In Note 4 p127 in the Integrated Circuits Section, it is indicated that in case of underfill, \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) should be divided by 3. This needs to be assessed before being recommended in the frame of this handbook.

Physical stresses for the integrated circuits family, except ASIC components:

Equation

(3.4.126)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

All other parameters are issued from the mission profile.

Equation

(3.4.127)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.128)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.129)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.130)#\[\Pi_{\text{RH}} = \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.131)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.92 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.93 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.94 Induced factor coefficient of sensitivity for integrated circuits.#

Technologies

\(C_{\text{sensitivity}}\)

Integrated circuits

6.3

Note

For the 2021 issue of FIDES, this value has been updated to 7.75, and for GaN MMICs, the value of 6.9 has been proposed.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.132)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.133)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.95 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for integrated circuits and ASICs.#

Integrated circuits, ASICs: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q100, MIL-PRF-38535 class V/Y, MIL-PRF-38510 class S, ESCC 90xx, NASDA-QTS-xxxx classe I, NPSL NASA level 1

Higher

3

Qualification according to one of the following standards: MIL-PRF-38535 class Q, MIL-PRF-38535 class M, MIL-PRF-38535 class N, MIL-PRF-38510 class B, NASDA-QTSxxxx class II, NPSL NASA levels 2 and 3

Equivalent

2

Qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

3.4.3.5.8.2. ASIC (40, 41 and 42 families)#

General model for the ASIC components:

Equation

(3.4.134)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{ProcessASIC}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{ProcessASIC}}\) the quality and technical control over the development of ASICs, as defined in 0

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1 and ASIC process factor \(\Pi_{\text{ProcessASIC}}\) according to Section 3.4.3.3.6.

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.135)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ {+ \lambda_{\text{ORH}} \cdot \Pi}_{\text{RH}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

\(\lambda_{\text{OTH}}\) is a fixed value given in the following table, depending on the type of components.

A specific value for the basic failure rate \(\lambda_{\text{OTH}}\) is provided for ASICs, depending on the type of components.

Table 3.4.96 Basic failure rates \(\lambda_{\text{OTH}}\) for ASICs.#
Type Type of ASIC function Groups λ0TH
MOS silicon Digital ASIC, simple function 40 0.021
Digital ASIC, complex function (with IP and/or µP core) 0.075
Analog, mixed ASIC 41 0.075
Bipole silicon, BiCMOS Digital ASIC 40 0.123
Mixed, analog ASIC 42 0.021

The basic failure rates \(\lambda_{\text{ORH}}\), \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) are calculated through two constants a and b considering the type of package and the number of pins. The formula to apply is:

Equation

(3.4.136)#\[\lambda_{0_{\text{constraint}}} = exp\left( - a \right) \cdot {N_{p}}^{b}\]

All packages have been split into the following six categories:

  • Plastic PTH;

  • Ceramic PTH;

  • Plastic SMD with leads;

  • Plastic SMD without leads;

  • Ceramic SMD with leads;

  • Ceramic SMD without leads.

Table 3.4.97 Families of packages for plastic PTH.#

Typical name

Description

SDIP

Skinny Dual In Line Package

ZIP

Zig-zag In Line Package

QIP

Quadruple In Line Package

PGA

Pin grid array

SIP, SIPP

Single In Line Package

Table 3.4.98 Families of packages for ceramic PTH.#

Typical name

Description

CERDIP, CDIP, sidebraze

Ceramic dual in line package

CPGA

Ceramic pin grid array

PDIP, TO116

Plastic dual in line package

Table 3.4.99 Families of packages for plastic SMD with leads.#

Typical name

Description

PQFP

Plastic quad flatpack, L lead

SQFP, TQFP, VQFP, LQFP, HLQFP

Plastic shrink quad flatpack, L lead Plastic thin quad flatpack, L lead

Power QFP (RQFP, HQFP, PowerQuad, EdQuad…)

Plastic quad flatpack with heat shink, L lead

BQFP

Bumpered quad flatpack, L lead

BQFPH

Bumpered quad flatpack with heat spreader, L lead

PLCC

Plastic leaded chip carrier, J lead

SOJ

Plastic small outlines, J-lead

SO, SOP, SOL, SOIC, SOW

Plastic small outlines, L lead

TSOP I

Thin small outlines, leads on small edges, L lead

TSOP II

Thin small outlines, leads on long edges, L lead

SSOP, VSOP, QSOP, VSSOP

Plastic shrink (pitch) small outlines, L lead

TSSOP, MSOP, µSOP, µMAX, TVSOP

Thin shrink small outlines, L lead

HSSOP, HVSSOP, HTSSOP

Thermally Enhanced SSOP

ePad, TSSOP, MSOP, SOIC, SSOP, PSOP

exposed TSSOP/MSOP/SOIC/SSOP

CGA, LGA

Column Grid Array

HSOP

Heat Sink Enhanced SOP

Table 3.4.100 Families of packages for plastic SMD with leads.#

Typical name

Description

PBGA WLP 0.3mm

Plastic ball grid array with solder ball pitch = 0.30 mm

PBGA CSP BT 0.8 et 0.75mm

Plastic ball grid array with solder ball pitch = 0.8 et 0.75 mm

PBGA flex 0.8mm

Plastic ball grid array with solder ball pitch = 0.8

PBGA BT 1.00mm

Plastic ball grid array with solder ball pitch = 1.00 mm

PBGA 1.27mm

Plastic ball grid array with solder ball pitch = 1.27 mm

PBGA 1.5mm

Plastic ball grid array with solder ball pitch = 1.5 mm

FPBGA

Fine pitch BGA

FCPBGA

Flip chip plastic BGA

Power BGA (TBGA, SBGA …)

Tape BGA, PBGA with heat sink, die top down pitch=1.27mm Super BGA, PBGA with heat sink, die top down pitch=1.27mm

MAPBGA

Moulded Array Process Ball Grid

QFN, aQFN, DFN, MLF, LLP, ODFN, WQFN, VQFN, X2QFN

Quad flat no lead

SON, USON, VSON, WSON, X2SON

Small Outline No Lead

TEPBGA

Thermally Enhanced Plastic Ball Grid Array

Other CSP

Customized leadframe-based CSP

Other CSP

Flexible substrate-based CSP

Other CSP

Rigid substrate-based CSP

Other CSP

Micro CSP

PSvfBGA

Package Stackable Very Thin Fine Pitch BGA (pop)

PSfcCSP

Package Stackable Flip Chip Chip Scale Package (pop)

TMV, SV

Through Mold Via (POP)

WL-CSP, WLP, WLB, WCSP, DSBGA

Wafer-level chip scale package

WLCSP+

Protected Wafer Level Chip Scale Package

WLFO, eWLB

Wafer Level Fan-Out

CABGA, LBGA

ChipArray BGA

CTBGA TFBGA

Thin ChipArray BGA

CVBGA, VFBGA

Very thin ChipArray BGA

Table 3.4.101 Families of packages for plastic SMD with leads.#

Typical name

Description

CERPACK

Ceramic Package

CQFP, Cerquad

Ceramic quad flatpack

CI CGA

Ceramic land GA + interposer, Ceramic column GA

CCGA, CLGA

Ceramic Column Grid Array

Table 3.4.102 Families of packages for plastic SMD with leads.#

Typical name

Description

FCBGA

Flip chip BGA

CBGA

Ceramic ball grid array

J-CLCC

J-lead Ceramic leaded chip carrier

CLCC

Ceramic leadless chip carrier

For specific or complex packages, the general model for Hybrids and Multi Chip Modules should be used.

For each stress \(\lambda_{\text{ORH}}\), \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) corresponding to the stress due to humidity, thermal cycling, thermal cycling of solder joints and mechanical stress, the recommendation for the parameters a and b for estimating the reliability of packages is slightly different according to the number of leads of the components.

For components with 0 to 256 leads, the recommendation for the parameters a and b is the following:

Table 3.4.103 Parameters a and b for components with 0 to 256 leads.#
Family λ0RH λ0TcyCase λ0TcySolderjoints λ0Mech
a b a b a b a b
Plastic PTH 5.88 0.94 9.85 1.35 8.24 1.35 12.85 1.35
Ceramic PTH 0.00 0.00 6.77 1.35 4.47 1.35 7.69 1.35
Plastic SMD with leads 8.48 1.47 12.81 1.92 9.81 1.92 15.20 1.92
Plastic SMD without leads 8.97 1.14 11.20 1.21 7.90 1.14 11.12 1.21
Ceramic SMD with leads 0.00 0.00 12.41 1.46 10.80 1.46 14.02 1.46
Ceramic SMD without leads 0.00 0.00 8.07 0.93 5.42 0.93 8.53 0.93

For components with more than 256 leads, the recommendation for the parameters a and b is the following:

Table 3.4.104 Parameters a and b for components with more than 256 leads.#
Family λ0RH λ0TcyCase λ0TcySolderjoints λ0Mech
a b a b a b a b
Ceramic PTH 0.00 0.00 8.07 0.93 4.85 0.93 7.85 0.93
Plastic SMD with leads 12.66 2.08 13.76 1.71 11.46 1.71 15.37 1.71
Plastic SMD without leads 8.38 1.20 12.25 1.32 9.09 1.32 12.78 1.32
Ceramic SMD with leads 0.00 0.00 12.09 1.59 12.28 1.66 12.11 1.66
Ceramic SMD without leads 0.00 0.00 15.37 1.87 11.68 1.87 14.68 1.87

Note

In the 2021 issue of FIDES, some evolution concerning the inclusing of underfill has been added. Hence, In Note 4 p127 in the Integrated Circuits section, it is indicated that in case of underfill, \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) should be divided by 3. This needs to be assessed before being recommended in the frame of this handbook.

Physical stresses for the integrated circuits family, ASIC components:

Equation

(3.4.137)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

All other parameters are issued from the mission profile.

Equation

(3.4.138)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.139)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.140)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.141)#\[\Pi_{\text{RH}} = \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.142)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.105 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.106 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.107 nduced factor coefficient of sensitivity for integrated circuits.#

Technologies

\(C_{\text{sensitivity}}\)

Integrated circuits

6.3

Note

For the 2021 issue of FIDES, this value has been updated to 7.75.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.143)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.144)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.108 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for integrated circuits and ASICs.#

Integrated circuits, ASICs: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q100, MIL-PRF-38535 class V/Y, MIL-PRF-38510 class S, ESCC 90xx, NASDA-QTS-xxxx classe I, NPSL NASA level 1

Higher

3

Qualification according to one of the following standards: MIL-PRF-38535 class Q, MIL-PRF-38535 class M, MIL-PRF-38535 class N, MIL-PRF-38510 class B, NASDA-QTSxxxx class II, NPSL NASA levels 2 and 3

Equivalent

2

Qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

3.4.3.5.8.3. Integrated Circuits (others)#

General model for the integrated circuits family, except ASIC and HF/RF components:

Equation

(3.4.145)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{LF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered. For Space applications, it is equal to 1 (see Section 3.4.3).

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1.

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.146)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ {+ \lambda_{\text{ORH}} \cdot \Pi}_{\text{RH}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

\(\lambda_{\text{OTH}}\) is a fixed value given in the following table, depending on the type of components.

Table 3.4.109 Basic failure rates \(\lambda_{\text{OTH}}\) for integrated circuits.#

Type

Groups

\(\lambda_{\text{OTH}}\)

FPGA, CPLD, FPGA Antifuse, PAL

30

0.166

Analog and Hybrid circuit (MOS, Bipole, BiCMOS)

50-69/80

0.123

Microprocessor, Microcontroller, DSP

10

0.075

Flash, EEPROM, EPROM

23-24

0.060

SRAM

20

0.055

DRAM

21

0.047

Digital circuit (MOS, Bipole, BiCMOS)

80

0.021

The basic failure rate \(\lambda_{\text{OTH}}\) is a fixed value given in the following table, depending on the type of components.

Equation

(3.4.147)#\[\lambda_{0_{\text{constraint}}} = exp\left( - a \right) \cdot {N_{p}}^{b}\]

All packages have been split into the following six categories:

  • Plastic PTH;

  • Ceramic PTH;

  • Plastic SMD with leads;

  • Plastic SMD without leads;

  • Ceramic SMD with leads;

  • Ceramic SMD without leads.

Table 3.4.110 Families of packages for plastic PTH.#

Typical name

Description

SDIP

Skinny Dual In Line Package

ZIP

Zig-zag In Line Package

QIP

Quadruple In Line Package

PGA

Pin grid array

SIP, SIPP

Single In Line Package

Table 3.4.111 Families of packages for ceramic PTH.#

Typical name

Description

CERDIP, CDIP, sidebraze

Ceramic dual in line package

CPGA

Ceramic pin grid array

PDIP, TO116

Plastic dual in line package

Table 3.4.112 Families of packages for plastic SMD with leads.#

Typical name

Description

PQFP

Plastic quad flatpack, L lead

SQFP, TQFP, VQFP, LQFP, HLQFP

Plastic shrink quad flatpack, L lead Plastic thin quad flatpack, L lead

Power QFP (RQFP, HQFP, PowerQuad, EdQuad…)

Plastic quad flatpack with heat shink, L lead

BQFP

Bumpered quad flatpack, L lead

BQFPH

Bumpered quad flatpack with heat spreader, L lead

PLCC

Plastic leaded chip carrier, J lead

SOJ

Plastic small outlines, J-lead

SO, SOP, SOL, SOIC, SOW

Plastic small outlines, L lead

TSOP I

Thin small outlines, leads on small edges, L lead

TSOP II

Thin small outlines, leads on long edges, L lead

SSOP, VSOP, QSOP, VSSOP

Plastic shrink (pitch) small outlines, L lead

TSSOP, MSOP, µSOP, µMAX, TVSOP

Thin shrink small outlines, L lead

HSSOP, HVSSOP, HTSSOP

Thermally Enhanced SSOP

ePad, TSSOP, MSOP, SOIC, SSOP, PSOP

exposed TSSOP/MSOP/SOIC/SSOP

CGA, LGA

Column Grid Array

HSOP

Heat Sink Enhanced SOP

Table 3.4.113 Families of packages for plastic SMD with leads.#

Typical name

Description

PBGA WLP 0.3mm

Plastic ball grid array with solder ball pitch = 0.30 mm

PBGA CSP BT 0.8 et 0.75mm

Plastic ball grid array with solder ball pitch = 0.8 et 0.75 mm

PBGA flex 0.8mm

Plastic ball grid array with solder ball pitch = 0.8

PBGA BT 1.00mm

Plastic ball grid array with solder ball pitch = 1.00 mm

PBGA 1.27mm

Plastic ball grid array with solder ball pitch = 1.27 mm

PBGA 1.5mm

Plastic ball grid array with solder ball pitch = 1.5 mm

FPBGA

Fine pitch BGA

FCPBGA

Flip chip plastic BGA

Power BGA (TBGA, SBGA …)

Tape BGA, PBGA with heat sink, die top down pitch=1.27mm Super BGA, PBGA with heat sink, die top down pitch=1.27mm

MAPBGA

Moulded Array Process Ball Grid

QFN, aQFN, DFN, MLF, LLP, ODFN, WQFN, VQFN, X2QFN

Quad flat no lead

SON, USON, VSON, WSON, X2SON

Small Outline No Lead

TEPBGA

Thermally Enhanced Plastic Ball Grid Array

Other CSP

Customized leadframe-based CSP

Other CSP

Flexible substrate-based CSP

Other CSP

Rigid substrate-based CSP

Other CSP

Micro CSP

PSvfBGA

Package Stackable Very Thin Fine Pitch BGA (pop)

PSfcCSP

Package Stackable Flip Chip Chip Scale Package (pop)

TMV, SV

Through Mold Via (POP)

WL-CSP, WLP, WLB, WCSP, DSBGA

Wafer-level chip scale package

WLCSP+

Protected Wafer Level Chip Scale Package

WLFO, eWLB

Wafer Level Fan-Out

CABGA, LBGA

ChipArray BGA

CTBGA TFBGA

Thin ChipArray BGA

CVBGA, VFBGA

Very thin ChipArray BGA

Table 3.4.114 Families of packages for plastic SMD with leads.#

Typical name

Description

CERPACK

Ceramic Package

CQFP, Cerquad

Ceramic quad flatpack

CI CGA

Ceramic land GA + interposer, Ceramic column GA

CCGA, CLGA

Ceramic Column Grid Array

Table 3.4.115 Families of packages for plastic SMD with leads.#

Typical name

Description

FCBGA

Flip chip BGA

CBGA

Ceramic ball grid array

J-CLCC

J-lead Ceramic leaded chip carrier

CLCC

Ceramic leadless chip carrier

For specific or complex packages, the general model for Hybrids and Multi Chip Modules should be used.

For each stress \(\lambda_{\text{ORH}}\), \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{Mech}}\) corresponding to the stress due to humidity, thermal cycling, thermal cycling of solder joints and mechanical stress, the recommendation for the parameters a and b for estimating the reliability of packages is slightly different according to the number of leads of the components.

For components with 0 to 256 leads, the recommendation for the parameters a and b is the following:

Table 3.4.116 Parameters a and b for components with 0 to 256 leads.#
Family λ0RH λ0TcyCase λ0TcySolderjoints λ0Mech
a b a b a b a b
Plastic PTH 5.88 0.94 9.85 1.35 8.24 1.35 12.85 1.35
Ceramic PTH 0.00 0.00 6.77 1.35 4.47 1.35 7.69 1.35
Plastic SMD with leads 8.48 1.47 12.81 1.92 9.81 1.92 15.20 1.92
Plastic SMD without leads 8.97 1.14 11.20 1.21 7.90 1.14 11.12 1.21
Ceramic SMD with leads 0.00 0.00 12.41 1.46 10.80 1.46 14.02 1.46
Ceramic SMD without leads 0.00 0.00 8.07 0.93 5.42 0.93 8.53 0.93

For components with more than 256 leads, the recommendation for the parameters a and b is the following:

Table 3.4.117 Parameters a and b for components with more than 256 leads.#
Family λ0RH λ0TcyCase λ0TcySolderjoints λ0Mech
a b a b a b a b
Ceramic PTH 0.00 0.00 8.07 0.93 4.85 0.93 7.85 0.93
Plastic SMD with leads 12.66 2.08 13.76 1.71 11.46 1.71 15.37 1.71
Plastic SMD without leads 8.38 1.20 12.25 1.32 9.09 1.32 12.78 1.32
Ceramic SMD with leads 0.00 0.00 12.09 1.59 12.28 1.66 12.11 1.66
Ceramic SMD without leads 0.00 0.00 15.37 1.87 11.68 1.87 14.68 1.87

Physical stresses for integrated circuits:

Equation

(3.4.148)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

All other parameters are issued from the mission profile.

Equation

(3.4.149)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.150)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.151)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.152)#\[\Pi_{\text{RH}} = \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.153)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.118 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.119 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.120 nduced factor coefficient of sensitivity for integrated circuits.#

Technologies

\(C_{\text{sensitivity}}\)

Integrated circuits

6.3

Note

For the 2021 issue of FIDES, this value has been updated to 7.75.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.154)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.155)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.121 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for integrated circuits and ASICs.#

Integrated circuits, ASICs: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q100, MIL-PRF-38535 class V/Y, MIL-PRF-38510 class S, ESCC 90xx, NASDA-QTS-xxxx classe I, NPSL NASA level 1

Higher

3

Qualification according to one of the following standards: MIL-PRF-38535 class Q, MIL-PRF-38535 class M, MIL-PRF-38535 class N, MIL-PRF-38510 class B, NASDA-QTSxxxx class II, NPSL NASA levels 2 and 3

Equivalent

2

Qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Integrated Circuits family 08

Section Component types Modifications and adaptations for space applications
08 Integrated Circuits

Merge of the models for integrated circuits and ASIC components

Consideration of 6 categories of packages

Values of basic failure rates λ0RH, λ0TcyCase, λ0TcySolderjoints and λ0Mech defined according to the 6 categories of packages

2021: Underfill & DSM considerations

2021: GaN MMIC inclusion

Note

In the 2021 issue of FIDES, new types of packages and associated values have been included; the impact needs to be evaluated.

3.4.3.5.9. Relays (family 09)#

Relays are classified as family 09 in EPPL [BR_EEE_9].

All relays used for Space applications can be modelled through FIDES, directly or indirectly.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.122 Groups of relays.#
Groups of relays Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Mono-stable relay (non latching) p148 p164 “Mono-stable relay” ECPL
02 Bi-stable relay (latching) No/Yes No/Yes As “Mono-stable relay” ECPL

General model for the relays family:

Equation

(3.4.156)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.157)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{Relay}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{Electrical}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

\(\lambda_{O_{\text{Relay}}}\) is equal to 1.1.

For space applications, \(\Pi_{\text{Chemical}}\) is equal to 0, \(\Pi_{\text{manoeuvres}}\) is equal to 1.

Physical stresses for the relays family:

Equation

(3.4.158)#\[\Pi_{\text{Thermal}} = 0.29 \cdot \Pi_{\text{TH\ contact}} \cdot \Pi_{\text{TH\ breaking}} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{313} - \frac{1}{273 + T^{'}} \right) \right\rbrack\]

\(E_{a}\) = 0.25eV;

Equation

(3.4.159)#\[\begin{split}T^{'} = \left\{ \begin{matrix} 40 - \frac{85}{55} \cdot \left( T_{board\_ ref} + \Delta T \right) & \mathrm{\text{if}}\ T_{board\_ ref} + \Delta T \leq 0{^\circ}C \\ 40{^\circ}C & \mathrm{\text{if}}\ {0{^\circ}C < T}_{board\_ ref} + \Delta T \leq 40{^\circ}C \\ T_{board\_ ref} + \Delta T & \mathrm{\text{if}}\ T_{board\_ ref} + \Delta T > 40{^\circ}C \\ \end{matrix} \right.\ \end{split}\]

\(\Pi_{\text{TH\ contact}}\) is equal to:

  • 1 for temperatures \(T_{board\_ ref} + \Delta T \leq 125{^\circ}C\);

  • \(\Pi_{\text{MEcontact}} \cdot \Pi_{\text{pole}}\) for temperatures higher than 125°C

  • With \(\Pi_{\text{Pole}}\) depending on the type of relay (for SPST \(\Pi_{\text{Pole}}\)= 1, for DPDT \(\Pi_{\text{Pole}}\)= 3, for 3PDT \(\Pi_{\text{Pole}}\)= 4.25 and for 4PDT \(\Pi_{\text{Pole}}\)= 5.5).

\(\Pi_{\text{ME\ contact}}\) is equal to:

  • 1.5 for gold plated contact;

  • 1.0 for silver plated contact.

\(\Pi_{\text{TH\ breaking}}\) is equal to:

  • 1.8 for a breaking capacity < 2A;

  • 1.2 for a breaking capacity ≥ 2A;

All other parameters are issued from the mission profile.

Equation

(3.4.160)#\[\Pi_{\text{Electrical}} = 0.55 \cdot \Pi_{\text{pole}} \cdot \Pi_{\text{EL\ breaking}} \cdot \Pi_{\text{load\ type}} \cdot {S_{V}}^{m_{1}} \cdot {S_{I}}^{m_{2}} \cdot \left( \frac{U_{\text{nominal}}}{U_{\text{coil}}} \right)\]

\(\Pi_{\text{Pole}}\) depending on the type of relay (for SPST \(\Pi_{\text{Pole}}\)= 1, for DPDT \(\Pi_{\text{Pole}}\)= 3, for 3PDT \(\Pi_{\text{Pole}}\)= 4.25 and for 4PDT \(\Pi_{\text{Pole}}\)= 5.5).

\(\Pi_{\text{EL\ breaking}}\) is equal to:

  • 1.5 for a breaking capacity < 2A;

  • 1.2 for a breaking capacity ≥ 2A;

\(\Pi_{\text{load\ type}}\), \(S_{V}\) and \(S_{I}\) are equal to:

Table 3.4.123 Electrical parameters of relays.#

Load type

\(\Pi_{\text{load\ type}}\)

\(S_{V}\)

\(S_{I}\)

Resistive

0.3

1

\(I_{\text{contact}}/I_{\text{nominal}}\)

Inductive

8

1

\(I_{\text{contact}}/I_{\text{nominal}}\)

Incandescent lamp

4

\(V_{\text{contact}}/V_{\text{nominal}}\)

\(I_{\text{contact}}/I_{\text{nominal}}\)

Capacitive

6

\(V_{\text{contact}}/V_{\text{nominal}}\)

1

\(m_{1}\) and \(m_{2}\) are equal to:

Table 3.4.124 Power parameters of relays.#

\(V_{\text{contact}}/V_{\text{nominal}}\)

\(m_{1}\)

\(I_{\text{contact}}/I_{\text{nominal}}\)

\(m_{2}\)

≤1

3

≤1

3

1

8.8

1

5.9

All other parameters are issued from the mission profile.

Equation

(3.4.161)#\[\Pi_{\text{Tcy}} = 0.02 \cdot \Pi_{\text{prot\ TCY}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(\Pi_{\text{prot\ TCY}}\) depends on the relay protection level:

  • 1 for hermetic relays;

  • 3 for sealed or not sealed relays.

All other parameters are issued from the mission profile.

Equation

(3.4.162)#\[\Pi_{\text{Mechanical}} = 0.05 \cdot \Pi_{\text{pole}} \cdot \Pi_{\text{ME\ contact}} \cdot \Pi_{\text{ME\ breaking}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(\Pi_{\text{pole}}\)= 4.25 and for 4PDT \(\Pi_{\text{pole}}\)= 5.5).

\(\Pi_{\text{ME\ contact}}\) is equal to:

  • 1.5 for gold plated contact;

  • 1 for silver plated contact.

\(\Pi_{\text{ME\ breaking}}\) is equal to:

  • 3 for a breaking capacity < 2A;

  • 1 for a breaking capacity ≥ 2A.

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.163)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.125 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.126 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.127 Induced factor coefficient of sensitivity for relays.#

Technologies

\(C_{\text{sensitivity}}\)

Relays

7.55

Note

For the 2021 issue of FIDES, this value has been updated to 7.43.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.164)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.165)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.128 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for electromechanical relays.#

Electromechanical relays: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: ESCC 360x, NASDA-QTS-39016A or specific manufacturer specifications based on ESCC

Higher

3

Qualification according to one of the following standards: MIL-PRF-39016 (or 83536 or 6106) level R, MIL-PRF-39016 (or 83536 or 6106) level P, NASDA-QTS-6106A

Equivalent

2

Qualification according to one of the following approved EIA, IEC, SAE, BS

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary or the Relays family 09

Section Component types Modifications and adaptations for space applications

Addition of the model for bi-stable relays (identical to the model for mono-stable relays)

Value of ΠChemical equal to 0

Value of Πmanoeuvres equal to 1

Removal of the humidity stress

3.4.3.5.10. Resistors (family 10)#

Resistors are classified as family 10 in EPPL [BR_EEE_9].

All resistors used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.129 Groups of resistors.#
Groups of resistors Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Metal Oxide

p130

p130

p130

p146

p146

p146

No more present in the EPPL but recommendation to use

“High stability bulk metal foil accuracy resistor”,

“Power film resistor” and

“Minimelf high stability (RS) common (RC) low power film resistor”

ECRE_08

ECRE_02

ECRE_01

02 Wirewound Precision (including Surface Mount) p130 p146 No more present in the EPPL but recommendation to use “Power wirewound resistor” ECRE_04
03 Wirewound Chassis Mounted p130 p146 No more present in the EPPL but recommendation to use “Power wirewound resistor” ECRE_04
04 Variables (trimmer) No No As trimmers are not allowed for space applications according to ECSS-Q-60, no model is provided for this group NA
05 Composition No No No more present in the EPPL NA
07 Shunt

p130

p130

p146

p146

For power shunt: “Power wirewound resistor”

For current sensor low power shunt: “High stability bulk metal foil accuracy resistor”

ECRE_04

ECRE_08

08 Metal Film

p130

p130

p130

p146

p146

p146

“High stability bulk metal foil accuracy resistor”,

“Power film resistor” and

“Minimelf high stability (RS) common (RC) low power film resistor”

ECRE_08

ECRE_02

ECRE_01

09 Chip (all) p130 p146 “Resistive chip” ECRE_06
10 Network (all) p130 p146 “SMD resistive network” ECRE_07
11 Heaters, Flexible No No Heaters and flexibles are not modelled in any standard NA

Note

HFRF resistors can also be modelled with FIDES, with the HFRF model.

General model for the resistors family:

Equation

(3.4.166)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.167)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{Resistor}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

\(\lambda_{O_{\text{Resistor}}}\) corresponds to the basic failure rate defined for sub-groups within the mentioned groups:

Table 3.4.130 Basic failure rates for resistors.#

Groups

Type of resistor

\(\lambda_{O_{\text{Resistor}}}\)

1, 8, 9b

Power film

0.4

2, 3

Power wirewound

0.4

1, 8, 9a

High stability

from 0.14 to 0.25 in [NR_EEE_2] page 131

1, 8, 9c

Minimelf

0.1

10

SMD resistive network

0.01 \(\sqrt{N_{R}}\)

With \(N_{R}\) as the number of resistors in the network.

Physical stresses for the resistors family:

Equation

(3.4.168)#\[\Pi_{\text{Thermal}} = \gamma_{TH\_ EL} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + A \cdot \frac{P_{\text{applied}}}{P_{\text{rated}}}} \right) \right\rbrack\]

\(E_{a}\) = 0.15eV;

\(\gamma_{TH\_ EL}\) and \(A\) depend on the type of resistors:

Table 3.4.131 Values of \(\gamma_{TH_ EL}\) for resistors.#

Groups

Type of resistor

\(A\)

\(\gamma_{TH\_ EL}\)

1, 8, 9b

Power film

130

0.04

2, 3

Power wirewound

130

0.01

1, 8, 9a

High stability

85

from 0.07 to 0.18 in [NR_EEE_2] page 131

1, 8, 9c

Minimelf

85

0.04

10

SMD resistive network

70

0.01

All other parameters are issued from the mission profile.

Equation

(3.4.169)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(\gamma_{\text{TCy}}\) depends on the type of resistors:

Table 3.4.132 Values of \(\gamma_{\text{TCy}}\) for resistors.#

Groups

Type of resistor

\(\gamma_{\text{TCy}}\)

1, 8, 9b

Power film

0.89

2, 3

Power wirewound

0.97

1, 8, 9a

High stability

from 0.43 to 0.55 in [NR_EEE_2] page 131

1, 8, 9c

Minimelf

0.89

10

SMD resistive network

0.97

Equation

(3.4.170)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(\gamma_{\text{Mech}}\) depends on the type of resistors:

Table 3.4.133 Values of \(\gamma_{\text{Mech}}\) for resistors.#

Groups

Type of resistor

\(\gamma_{\text{Mech}}\)

1, 8, 9b

Power film

0.01

2, 3

Power wirewound

0.01

1, 8, 9a

High stability

from 0.05 to 0.08 in [NR_EEE_2] page 131

1, 8, 9c

Minimelf

0.01

10

SMD resistive network

0.01

All other parameters are issued from the mission profile.

Equation

(3.4.171)#\[\Pi_{\text{RH}} = {\gamma_{\text{RH}} \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)}^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + A \cdot \frac{P_{\text{applied}}}{P_{\text{rated}}}} \right) \right\rbrack\]

\(\gamma_{\text{RH}}\) depends on the type of resistors:

Table 3.4.134 Values of \(\gamma_{\text{RH}}\) for resistors.#

Groups

Type of resistor

\(\gamma_{\text{RH}}\)

1, 8, 9b

Power film

0.06

2, 3

Power wirewound

0.01

1, 8, 9a

High stability

from 0.26 to 0.41 in [NR_EEE_2] page 131

1, 8, 9c

Minimelf

0.06

10

SMD resistive network

0.01

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.172)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.135 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.136 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.137 Induced factor coefficient of sensitivity for resistors.#

Technologies

\(C_{\text{sensitivity}}\)

Power film

2.25

Power wirewound

2.25

High stability

5.80

Minimelf

3.85

SMD resistive network

4.25

Note

For the 2021 issue of FIDES, these values have been updated, as well the overall denomination of the categories of resistors.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.173)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.174)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.138 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for resistors.#

Resistors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200, MIL-PRF-xxxx level T, MIL-PRF-xxxx level S, MIL-PRF-xxxx level R, ESCC 400x, NASDA-QTS-xxxx class I (JAXA-QTS-2050D)

Higher

3

Qualification according to one of the following standards: MIL-PRF-xxx level P, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards, qualification according to approved CECC standards.

Equivalent

2

Qualification according to MIL-PRF-xxxx level M, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Resistors family 10

Section Component types Modifications and adaptations for space applications
10 Resistors

-

3.4.3.5.11. Thermistors (family 11)#

Thermistors are classified as family 11 in EPPL [BR_EEE_9].

FIDES does not present models for thermistors, hence the models detailed hereafter as based on resistors models. The pages where the models can be found in the two versions of the FIDES guide (2009 & 2021) are provided in the following table.

Table 3.4.139 Groups of thermistors.#
Groups of thermistors Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Temperature compensating

No/Yes

p130

No/Yes

p146

"“Minimelf" high stability (RS) common (RC) low power film resistor”,

“Low power wirewound accuracy resistor”,

“High stability bulk metal foil accuracy resistor”

ECRE_01

ECRE_03

ECRE_08

02 Temperature measuring

No/Yes

p130

No/Yes

p146

"“Minimelf" high stability (RS) common (RC) low power film resistor”,

“Low power wirewound accuracy resistor”,

“High stability bulk metal foil accuracy resistor”

ECRE_01

ECRE_03

ECRE_08

03 Temperature sensor

No/Yes

p130

No/Yes

p146

"“Minimelf" high stability (RS) common (RC) low power film resistor”,

“Low power wirewound accuracy resistor”,

“High stability bulk metal foil accuracy resistor”

ECRE_01

ECRE_03

ECRE_08

General model for the thermistors family

Equation

(3.4.175)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item, see Section 3.4.3.3.1,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.176)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{Thermistor}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

\(\lambda_{O_{\text{Thermistor}}}\) corresponds to the basic failure rate defined for sub-groups within the mentioned groups:

Table 3.4.140 Basic failure rates for thermistors.#

Groups

Type of resistor

\(\lambda_{O_{\text{Thermistor}}}\)

1, 2, 3

Low power wirewound

0.3

1, 2, 3

High stability

from 0.14 to 0.25 in FIDES page 131

1, 2, 3

Minimelf

0.1

Physical stresses for the thermistors family:

Equation

(3.4.177)#\[\Pi_{\text{Thermal}} = \gamma_{TH\_ EL} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + A \cdot \frac{P_{\text{applied}}}{P_{\text{rated}}}} \right) \right\rbrack\]

\(E_{a}\) = 0.15eV;

\(\gamma_{TH\_ EL}\) and \(A\) depend on the type of thermistors:

Table 3.4.141 Values of \(\gamma_{TH_ EL}\) for thermistors.#

Groups

Type of resistor

\(A\)

\(\gamma_{TH\_ EL}\)

1, 2, 3

Low power wirewound

30

0.02

1, 2, 3

High stability

85

from 0.07 to 0.18 in FIDES page 131

1, 2, 3

Minimelf

85

0.04

All other parameters are issued from the mission profile.

Equation

(3.4.178)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(\gamma_{\text{TCy}}\) depends on the type of thermistors:

Table 3.4.142 Values of \(\gamma_{\text{TCy}}\) for thermistors.#

Groups

Type of resistor

\(\gamma_{\text{TCy}}\)

1, 2, 3

Low power wirewound

0.96

1, 2, 3

High stability

from 0.43 to 0.55 in FIDES p131

1, 2, 3

Minimelf

0.89

All other parameters are issued from the mission profile.

Equation

(3.4.179)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(\gamma_{\text{Mech}}\) depends on the type of thermistors:

Table 3.4.143 Values of \(\gamma_{\text{Mech}}\) for thermistors.#

Groups

Type of resistor

\(\gamma_{\text{Mech}}\)

1, 2, 3

Low power wirewound

0.01

1, 2, 3

High stability

from 0.05 to 0.08 in FIDES p131

1, 2, 3

Minimelf

0.01

All other parameters are issued from the mission profile.

Equation

(3.4.180)#\[Pi_{\text{RH}} = {\gamma_{\text{RH}} \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)}^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + A \cdot \frac{P_{\text{applied}}}{P_{\text{rated}}}} \right) \right\rbrack\]

\(\gamma_{\text{RH}}\) depends on the type of thermistors:

Table 3.4.144 Values of \(\gamma_{\text{RH}}\) for thermistors.#

Groups

Type of resistor

\(\gamma_{\text{RH}}\)

1, 2, 3

Low power wirewound

0.01

1, 2, 3

High stability

from 0.26 to 0.41 in FIDES p131

1, 2, 3

Minimelf

0.06

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.181)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.145 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.146 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.147 Induced factor coefficient of sensitivity for thermistors.#

Technologies

\(C_{\text{sensitivity}}\)

Low power wirewound

1.75

High stability

5.80

Minimelf

3.85

Note

For the 2021 issue of FIDES, these values have been updated to 1.83, 4.95 and 3.55.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.182)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.183)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.148 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for thermistors.#

Thermistors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200, MIL-PRF-xxxx level T, MIL-PRF-xxxx level S, MIL-PRF-xxxx level R, ESCC 400x, NASDA-QTS-xxxx class I (JAXA-QTS-2050D)

Higher

3

Qualification according to one of the following standards: MIL-PRF-xxx level P, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards, qualification according to approved CECC standards.

Equivalent

2

Qualification according to MIL-PRF-xxxx level M, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Thermistors family 10

Section Component types Modifications and adaptations for space applications
11 Thermistors

Addition of the model for thermistors

3.4.3.5.12. Transistors (family 12)#

General transistors and RF HF transistors are classified as family 12 in EPPL [BR_EEE_9].

All transistors used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.149 Groups of transistors.#
Groups of transistors Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Low Power, NPN (< 2watts) p120 p133 Low power Transistors “Silicon bipolar < 5W” ECDS_20
02 Low Power, PNP (< 2watts) p120 p133 Low power Transistors “Silicon bipolar < 5W” ECDS_20
03 High Power, NPN (> 2watts) p120 p133 Power Transistors “Silicon bipolar > 5W” ECDS_21
04 High Power, PNP (> 2watts) p120 p133 Power Transistors “Silicon bipolar > 5W” ECDS_21
05 FET N Channel p120 p133

Low power Transistors

“Silicon MOS < 5W”,

“Silicon JFET < 5W”

ECDS_19

ECDS_18

06 FET P Channel p120 p133

Low power Transistors

“Silicon MOS < 5W”,

“Silicon JFET < 5W”

ECDS_19

ECDS_18

10 RF/microwave Npn Low Power / Low Noise p185 p211

RF HF Low power Transistors

“Silicon Bipolar < 5W”,

“SiGe, bipolar < 1W”

HFDI_02

HFDI_03

11 RF/microwave Pnp Low Power / Low Noise p185 p211

RF HF Low power Transistors

“Silicon Bipolar < 5W”,

“SiGe, bipolar < 1W”

HFDI_02

HFDI_03

13 RF/microwave Bipolar Power p185 p211 RF HF Power Transistors “Silicon Bipolar > 5W” HFDI_05
12 RF/microwave FET N-channel/ P-channel No No No more present in the EPPL NA
14 RF/microwave FET Power (Si) p185 p211 No more present in the EPPL but recommendation to use RF HF Power Transistors “Silicon MOS > 5W” HFDI_06
15 Microwave Power (GaAs) p185 p211 No more present in the EPPL but recommendation to use RF HF Power Transistors “GaAs>1W” HFDI_07
16 Microwave Low Noise (GaAs) p185 p211

No more present in the EPPL but recommendation to use

RF HF Low power Transistors “GaAs<1W”,

RF HF Power Transistors “GaAs>1W”

HFDI_04

HFDI_07

08 Multiple No/Yes No/Yes No more present in the EPPL but recommendation to model as the sum of all individual transistors NA
09 Switching p120 p133 No more present in the EPPL but recommendation to use Low power Transistors “Silicon bipolar < 5W” ECDS_20
17 Chopper p120 p133

Low power Transistors

“Silicon bipolar < 5W”,

“Silicon MOS < 5W”,

“Silicon JFET < 5W”

ECDS_20

ECDS_19

ECDS_18

3.4.3.5.12.1. HF/RF Transistors (10, 11, 13, 14, 15 families)#

General model for the general transistors and the HF/RF transistors family:

Equation

(3.4.184)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{ProcessRFHF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{ProcessRFHF}}\) the quality and technical control over the development, manufacturing and use process for the RFHF item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

With process factor \(\Pi_{\text{Process}}\) according to Section 3.4.3.3.1 and HF/RF process factor \(\Pi_{\text{ProcessRFHF}}\) according to Section 3.4.3.3.5.

Note

In the 2021 issue of FIDES, a GaN Transistor model has been included. The detail is provided in Section 3.4.4.2.3, as it has not yet been assessed and is just a proposition for the user.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.185)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

The basic failure rates \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{OMech}}\) are provided in the following table according for the packages SODxx and TOxx specifically used in space applications:

Table 3.4.150 Basic failure rates \(\lambda_{0}\) for transistors.#

Case

Equivalent name

Description

\(\lambda_{\text{OTCyCase}}\)

\(\lambda_{\text{OTCySolderjoints}}\)

\(\lambda_{\text{OMech}}\)

SOD80

Mini-MELF, DO213AA

SMD, Hermetically sealed glass

0.00781

0.03905

0.00078

SOD87

MELF, DO213AB

SMD, Hermetically sealed glass

0.00781

0.03905

0.00078

TO18

TO71, TO72, SOT31, SOT18

Through hole, metal

0.0101

0.0505

0.00101

TO39

SOT5

Through hole, metal

0.0101

0.0505

0.00101

TO52

Through hole, metal

0.0101

0.0505

0.00101

\(\lambda_{\text{OTH}}\) is a fixed value given in another table, depending on the type of components.

Table 3.4.151 Basic failure rates \(\lambda_{\text{OTH}}\) for HF/RF transistors.#

Type

\(\lambda_{\text{OTH}}\)

Power HF/RF transistor – GaAs > 1W

0.0927*

Low power HF/RF transistor – GaAs < 1W

0.0488*

Power HF/RF transistor – Silicon Bipolar > 5W

0.0478

Power HF/RF transistor – Silicon MOS > 5W

0.0202

Low power HF/RF transistor – Silicon, Bipolar <5W / SiGe, Bipolar <1W

0.0138

Note *

\(\lambda_{\text{OTH}}\) for Power HF/RF has been updated in the 2021 issue of the FIDES guide to 0.3756.

Physical stresses for the general transistors and the RF HF transistors family:

Equation

(3.4.186)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

Equation

(3.4.187)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.188)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ annual}}{t_{\text{annual}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.189)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

All parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.190)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.152 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.153 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.154 Induced factor coefficient of sensitivity for thermistors.#

Technologies

\(C_{\text{sensitivity}}\)

Si or SiGe RF transistors

6.30

GaAs RF transistors

7.40

Note

For the 2021 issue of FIDES, these values have not been updated.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.191)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.192)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.155 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for transistors.#

Transistors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q101, AEC Q102, MIL-PRF-19500 JANS, ESCC 5000, ESCC 5010 level B, NASDA-QTS-xxxx class I, JAXA-QTS Class I (NASDA-QTS-2030)

Higher

3

Qualification according to one of the following standards: MIL-PRF-19500 JANTX or JANTXV, ESCC 5010 level C, NASDA-QTS-xxxx class II, JAXA-QTS Class II

Equivalent

2

Qualification according to one of the following standards: MIL-PRF-19500 JAN or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

3.4.3.5.12.2. Transistors (other)#

General model for the general transistors and the transistors family:

Equation

(3.4.193)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

All this being based on a mission profile to be defined for the whole unit.

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.194)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

The basic failure rates \(\lambda_{\text{OTCyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\) and \(\lambda_{\text{OMech}}\) are provided in the following table according for the packages SODxx and TOxx specifically used in space applications:

Table 3.4.156 Basic failure rates \(\lambda_{0}\) for transistors.#

Case

Equivalent name

Description

\(\lambda_{\text{OTCyCase}}\)

\(\lambda_{\text{OTCySolderjoints}}\)

\(\lambda_{\text{OMech}}\)

SOD80

Mini-MELF, DO213AA

SMD, Hermetically sealed glass

0.00781

0.03905

0.00078

SOD87

MELF, DO213AB

SMD, Hermetically sealed glass

0.00781

0.03905

0.00078

TO18

TO71, TO72, SOT31, SOT18

Through hole, metal

0.0101

0.0505

0.00101

TO39

SOT5

Through hole, metal

0.0101

0.0505

0.00101

TO52

Through hole, metal

0.0101

0.0505

0.00101

\(\lambda_{\text{OTH}}\) is a fixed value given in another table, depending on the type of components.

Table 3.4.157 Basic failure rates \(\lambda_{\text{OTH}}\) for other types of transistors.#

Type

\(\lambda_{\text{OTH}}\)

Power transistor – Silicon, Bipolar >5W

0.0478

Power transistor – Silicon MOS > 5W

0.0202

Low power transistor – Silicon MOS < 5W

0.0145

Low power transistor – Silicon JFET < 5W

0.0143

Low power transistor – Silicon Bipolar < 5W

0.0138

Physical stresses for the general transistors and the RF HF transistors family:

Equation

(3.4.195)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV;

Equation

(3.4.196)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.197)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ annual}}{t_{\text{annual}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.198)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

All parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.199)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.158 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.159 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.160 Induced factor coefficient of sensitivity for transistors.#

Technologies

\(C_{\text{sensitivity}}\)

Regular transistors

5.20

Note

Note: For the 2021 issue of FIDES, this value has been updated to 5.20.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.200)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.201)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} + \text{RA}_{\text{component}} \right) \times \varepsilon}{36}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.161 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for thermistors.#

Transistors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q101, AEC Q102, MIL-PRF-19500 JANS, ESCC 5000, ESCC 5010 level B, NASDA-QTS-xxxx class I, JAXA-QTS Class I (NASDA-QTS-2030)

Higher

3

Qualification according to one of the following standards: MIL-PRF-19500 JANTX or JANTXV, ESCC 5010 level C, NASDA-QTS-xxxx class II, JAXA-QTS Class II

Equivalent

2

Qualification according to one of the following standards: MIL-PRF-19500 JAN or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Transistors family 12

Section Component types Modifications and adaptations for space applications
12 Transistors

Consideration of packages SODxx and TOxx only

Removal of the humidity stress ΠRH

3.4.3.5.13. Transformers (family 13)#

Transformers are classified as family 13 in EPPL [BR_EEE_9].

All transformers used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.162 Groups of transformers.#
Groups of transformers Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Power p142 p160 “Transformer, High Power”
02 Signal p142 p160 “Transformer, Low Power (or Low Level)”

General model for the transformers family

Equation

(3.4.202)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{Process}} \cdot \Pi_{\text{LF}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item, see Section 3.4.3.3.1,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.203)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{Magnetic}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

with:

  • \(\lambda_{OTH}\) : Base thermal failure rate

  • \(\Pi_{\text{thermo-electrical}}\) : Thermo-electrical factor

  • \(\Pi_{\text{TCy}}\) : Cycling factor

  • \(\Pi_{\text{Mechanical}}\) : Mechanical factor

  • \(\Pi_{\text{induced}}\) : Induced factor

  • \(\Pi_{\text{PM}}\) : Part Manufacturing factor

  • \(\Pi_{\text{P}}\) : Process factor

\(\lambda_{O_{\text{Magnetic}}}\) mentioned groups:

  • For low power (or low level) transformers (lower than 100W or 100VA), \(\lambda_{O_{\text{Magnetic}}}\) is equal to 0.125;

  • For high power transformers (equal to or higher than 100W or 100VA), \(\lambda_{O_{\text{Magnetic}}}\) is equal to 0.25.

Physical stresses for the thermistors family:

Equation

(3.4.204)#\[\Pi_{\text{Thermal}} = \gamma_{TH\_ EL} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.15eV;

\(\gamma_{TH\_ EL}\) depends on the type of transformers:

  • For low power (or low level) transformers (lower than 100W or 100VA), \(\gamma_{TH\_ EL}\) is equal to 0.01;

  • For high power transformers (equal to or higher than 100W or 100VA), \(\gamma_{TH\_ EL}\) is equal to 0.15.

All other parameters are issued from the mission profile.

Equation

(3.4.205)#\[\Pi_{\text{Tcy}} = \gamma_{\text{TCy}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(\gamma_{\text{TCy}}\) depends on the type of transformers:

  • For low power (or low level) transformers (lower than 100W or 100VA), \(\gamma_{\text{TCy}}\) is equal to 0.73;

  • For high power transformers (equal to or higher than 100W or 100VA), \(\gamma_{\text{TCy}}\) is equal to 0.69.

All other parameters are issued from the mission profile.

Equation

(3.4.206)#\[\Pi_{\text{Mechanical}} = \gamma_{\text{Mech}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(\gamma_{\text{Mech}}\) depends on the type of transformers:

  • For low power (or low level) transformers (lower than 100W or 100VA), \(\gamma_{\text{Mech}}\) is equal to 0.26;

  • For high power transformers (equal to or higher than 100W or 100VA), \(\gamma_{\text{Mech}}\) is equal to 0.16.

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.207)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.163 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.164 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.165 Induced factor coefficient of sensitivity for transformers.#

Technologies

\(C_{\text{sensitivity}}\)

For low power (or low level) transformers (lower than 100W or 100VA)

6.90

For high power transformers (equal to or higher than 100W or 100VA)

6.80

Note

For the 2021 issue of FIDES, these values have been updated to 5.63 and 6.13.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.208)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.209)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.166 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for thermistors.#

Thermistors: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q200, MIL-STD-981 class S, MIL-PRF-xxx level T, ESCC 320x, NASDA-QTS-xxxx class I

Higher

3

Qualification according to one of the following standards: MIL-STD-981 class B, MIL-PRF-xxx level M, NASDA-QTS-xxxx class II with identification of manufacturing sites for these standards, qualification according to approved CECC standards.

Equivalent

2

Qualification according to one of the following MIL-PRF-xxxx level C, or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Transformers family 13

Section Component types Modifications and adaptations for space applications
13 Transformers

Definition of the limit between low power and high power transformers

3.4.3.5.14. Switches (family 14)#

Switches are classified as family 14 in EPPL [BR_EEE_9].

Most of the switches used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.167 Groups of switches.#
Groups of switches Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Standard DC/AC power toggle p150 p168 “Toggle” ECSW
02 Circuit breaker No No Not used in space applications
03 RF switch No No Based on the number of operations of the part
04 Microswitch No/Yes No/Yes Recommendation to use “Toggle” ECSW
05 Reed switch No/Yes No/Yes Recommendation to use “Toggle” ECSW

General model for the switches family

Equation

(3.4.210)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item, see Section 3.4.3.3.1,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.211)#\[\lambda_{\text{Physical}} = \lambda_{O_{\text{Switch}}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{Thermal}} + \Pi_{\text{Electrical}} + \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

\(\lambda_{O_{\text{Switch}}}\) is equal to 0.85 whatever the switch.

For space applications, \(\Pi_{\text{Chemical}}\) is equal to 0, \(\Pi_{\text{manoeuvres}}\) is equal to 1.

Physical stresses for the switches family:

Equation

(3.4.212)#\[\Pi_{\text{Thermal}} = 0.21 \cdot C_{\text{TH}} \cdot \Pi_{\text{TH\ contact}} \cdot exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{313} - \frac{1}{273 + T^{'}} \right) \right\rbrack\]

\(E_{a}\) = 0.25eV; \(C_{\text{TH}}\) = 1.11;

Equation

(3.4.213)#\[\begin{split}T^{'} = \left\{ \begin{matrix} 40 - \frac{85}{55} \cdot \left( T_{board\_ ref} + \Delta T \right) & \mathrm{\text{if}}\ T_{board\_ ref} + \Delta T \leq 0{^\circ}C \\ 40{^\circ}C & \mathrm{\text{if}}\ {0{^\circ}C < T}_{board\_ ref} + \Delta T \leq 40{^\circ}C \\ T_{board\_ ref} + \Delta T & \mathrm{\text{if}}\ T_{board\_ ref} + \Delta T > 40{^\circ}C \\ \end{matrix} \right.\ \end{split}\]

\(\Pi_{\text{TH\ contact}}\) is equal to:

  • 1 for temperatures \(T_{board\_ ref} + \mathrm{\Delta}T \leq 125{^\circ}C\);

  • \(\Pi_{\text{MEcontact}} \cdot \Pi_{\text{pole}}\) for temperatures higher than 125°C;

  • With \(\Pi_{\text{pole}}\) depending on the type of switch (for SPST \(\Pi_{\text{pole}}\)= 1, for DPDT \(\Pi_{\text{pole}}\)= 3, for 3PDT \(\Pi_{\text{pole}}\)= 4.25 and for 4PDT \(\Pi_{\text{pole}}\)= 5.5).

\(\Pi_{\text{ME\ contact}}\) is equal to:

  • 1.5 for gold plated contact;

  • 1.0 for silver plated contact.

All other parameters are issued from the mission profile.

Equation

(3.4.214)#\[\Pi_{\text{Electrical}} = 0.59 \cdot {C_{\text{EL}} \cdot \Pi}_{\text{pole}} \cdot \Pi_{\text{EL\ breaking}} \cdot \Pi_{\text{load\ type}} \cdot {S_{V}}^{m_{1}} \cdot {S_{I}}^{m_{2}}\]

\(C_{\text{EL}}\) = 0.56;

\(\Pi_{\text{pole}}\) depending on the type of switch (for SPST \(\Pi_{\text{pole}}\)= 1, for DPDT \(\Pi_{\text{pole}}\)=3, for 3PDT \(\Pi_{\text{pole}}\)=4.25 and for 4PDT \(\Pi_{\text{pole}}\)=5.5).

\(\Pi_{\text{EL\ breaking}}\) is equal to:

  • 1.5 for a breaking capacity < 2A;

  • 1.2 for a breaking capacity ≥ 2A;

\(\Pi_{\text{load\ type}}\), \(S_{V}\) and \(S_{I}\) are equal to:

Table 3.4.168 Electrical parameters of switches.#

Load type

\(\Pi_{\text{load\ type}}\)

\(S_{V}\)

\(S_{I}\)

Resistive

0.3

1

\(I_{\text{contact}}/I_{\text{nominal}}\)

Inductive

8

1

\(I_{\text{contact}}/I_{\text{nominal}}\)

Incandescent lamp

4

\(V_{\text{contact}}/V_{\text{nominal}}\)

\(I_{\text{contact}}/I_{\text{nominal}}\)

Capacitive

6

\(V_{\text{contact}}/V_{\text{nominal}}\)

1

\(m_{1}\) and \(m_{2}\) are equal to:

Table 3.4.169 Power parameters of switches.#

\(V_{\text{contact}}/V_{\text{nominal}}\)

\(m_{1}\)

\(I_{\text{contact}}/I_{\text{nominal}}\)

\(m_{2}\)

≤1

3

≤1

3

>1

8.8

>1

5.9

All other parameters are issued from the mission profile.

Equation

(3.4.215)#\[\Pi_{\text{Tcy}} = 0.02 \cdot \Pi_{\text{prot\ TCY}} \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

\(C_{\text{TCy}}\) = 0.56;

\(\Pi_{\text{pole}}\) depends on the type of switch (for SPST \(\Pi_{\text{pole}}\)= 1, for DPDT \(\Pi_{\text{pole}}\)= 3, for 3PDT \(\Pi_{\text{pole}}\)= 4.25 and for 4PDT \(\Pi_{\text{pole}}\)= 5.5).

\(\Pi_{\text{prot\ TCY}}\) depends on the switch protection level:

  • 1 for hermetic switch;

  • 3 for sealed or not sealed switch.

All other parameters are issued from the mission profile.

Equation

(3.4.216)#\[\Pi_{\text{Mechanical}} = 0.06 \cdot C_{\text{MECH}} \cdot \Pi_{\text{pole}} \cdot \Pi_{\text{ME\ contact}} \cdot \Pi_{\text{ME\ breaking}} \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

\(C_{\text{MECH}}\) = 1.11;

\(\Pi_{\text{pole}}\) depending on the type of switch (for SPST \(\Pi_{\text{pole}}\)= 1, for DPDT \(\Pi_{\text{pole}}\)= 3, for 3PDT \(\Pi_{\text{pole}}\)= 4.25 and for 4PDT \(\Pi_{\text{pole}}\)= 5.5).

\(\Pi_{\text{ME\ contact}}\) is equal to:

  • 1.5 for gold plated contact;

  • 1 for silver plated contact.

\(\Pi_{\text{ME\ breaking}}\) is equal to:

  • 3 for a breaking capacity < 2A;

  • 1 for a breaking capacity ≥ 2A.

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.217)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.170 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.171 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.172 Induced factor coefficient of sensitivity for switches.#

Technologies

\(C_{\text{sensitivity}}\)

Switches

7.45

Note

For the 2021 issue of FIDES, this value has not updated to 7.38.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.218)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.219)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.173 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for switches.#

Switches: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: ESCC 370x, MIL-PRF-8805

Higher

3

Qualification according to one of the following standards: MIL-PRF-24236, MIL-C-xxxx

Equivalent

2

Qualification according to one of the following approved EIA, IEC, SAE, BS

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Switches family 14

Section Component types Modifications and adaptations for space applications
14 Switches

Parameters for “Toggle” switch only

Value of ΠChemical equal to 0

Value of Πmanoeuvres equal to 1

Removal of the humidity stress ΠRH

3.4.3.5.15. Opto-electronics (family 18)#

Opto-electronics are classified as family 18 in EPPL [BR_EEE_9].

Some of the opto-electronics components used for Space applications can be modelled through FIDES.

The following table presents the different subfamilies and the corresponding models with the FIDES method, giving the pages where it can be found in both versions (2009 & 2021), for information.

Table 3.4.174 Groups of opto-electronics.#
Groups of opto-electronics Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
01 Optocoupler p128 p144

“Optocoupler with photodiode”

“Optocouple with phototransistor”

ECOP_01

ECOP_02

02 LED p125 p141 “LED” but not much used in space applications ECLE
03 Phototransistor No No Telcordia SR-332 : “phototransistor” after investigation and assessment. NA
04 Photodiode No No Telcordia SR-332 : “photodiode” after investigation and assessment. NA
05 Laser diode No No Telcordia SR-332 : “Single LED/LCD Segment” after investigation and assessment. NA
06 CCD No No “ASIC, Silicon bipolar, BiCMOS, Digital ASIC” ECAS
07 LCD screen p206 p232 “LCD screens (TFT, STN)” but not used in space applications NA
Laser detector No No Telcordia SR-332 : “Laser Module - CW Laser” after investigation and assessment. NA
Laser transceiver No No Telcordia SR-332: “Laser Module - CW Laser” after investigation and assessment. NA

Note

Investigation and assessment according to Section 3.4.4.1.

3.4.3.5.15.1. LED#

General model for the opto-electronics family:

Equation

(3.4.220)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item, see Section 3.4.3.3.1,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.221)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \lambda_{\text{OTCySolderjoints}} \cdot \Pi}_{\text{TCySolderjoints}} \\ {+ \lambda_{\text{ORH}} \cdot \Pi}_{\text{RH}} \\ + \lambda_{\text{OMech}} \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

For LEDs, the basic failure rates \(\lambda_{\text{OTH}}\) are fixed values depending on the colour of the LED:

Table 3.4.175 Basic failure rates \(\lambda_{\text{OTH}}\) for LEDs.#

Component description

\(\lambda_{\text{OTH}}\)

White colour

0.05

Other colours

0.01

All other basic failure rates \(\lambda_{\text{ORH}}\), \(\lambda_{\text{0TcyCase}}\), \(\lambda_{\text{0TcySolderJoints}}\) and \(\lambda_{\text{0Mech}}\) depend on the maximum direct current, whether the part is feedthrough or SMD, and on the case type as follows:

Table 3.4.176 Basic failure rates \(\lambda_{\text{ORH}}\), \(\lambda_{\text{0TcyCase}}\), \(\lambda_{\text{0TcySolderJoints}}\) and \(\lambda_{\text{0Mech}}\) for LEDs.#
Direct current IF maximum SMD or Through hole Case type Number of pins λORH λ0TcyCase λ0TcySolderJoint λ0Mech
IF < 150mA Through T1-x Plastic 2 to 4 0.0034 0.0104 0.0520 0.0052
High flux 4
SMD Chip 2
PLCC Min 2
2
3
4
6
Round 2 0.1560 0.0624
LGA Plastic 2 0.2080 0.0832
Ceramic 0.3640 0.1820
Other Plastic In-different 0.1560 0.0624
Ceramic 0.3640 0.1820
IF ≥ 150mA SMD Plastic In-different 0.0031 0.0042 0.0420 0.0064
Ceramic 0.1470 0.0735

Physical stresses for the opto-electronics family:

Equation

(3.4.222)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.4eV for LEDs. All other parameters are issued from the mission profile.

Equation

(3.4.223)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.224)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.225)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.226)#\[\Pi_{\text{RH}} = \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.227)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.177 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.178 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.179 Induced factor coefficient of sensitivity for opto-electronics.#

Technologies

\(C_{\text{sensitivity}}\)

LEDs

4.85

Note

For the 2021 issue of FIDES, this value has been updated to 5.68.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.228)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.229)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.180 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for opto-electronics.#

Optocouplers, LEDs: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q101, AEC Q102, MIL-PRF-19500 JANS, ESCC 5000, ESCC 5010 level B, NASDA-QTS-xxxx class I, JAXA-QTS Class I (NASDA-QTS-2030)

Higher

3

Qualification according to one of the following standards: MIL-PRF-19500 JANTX or JANTXV, ESCC 5010 level C, NASDA-QTS-xxxx class II, JAXA-QTS Class II

Equivalent

2

Qualification according to one of the following standards: MIL-PRF-19500 JAN or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

3.4.3.5.15.2. Opto (other)#

General model for the opto-electronics family:

Equation

(3.4.230)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item, see Section 3.4.3.3.1,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.231)#\[\begin{split}\lambda_{\text{Physical}} = \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \begin{pmatrix} {\lambda_{\text{OTH}} \cdot \Pi}_{\text{Thermal}} \\ {+ \lambda_{\text{OTCyCase}} \cdot \Pi}_{\text{TCyCase}} \\ \begin{matrix} {+ \left( \lambda_{\text{OTCySolderjoints}} + \lambda_{\text{OTCyChip}} \right) \cdot \Pi}_{\text{TCySolderjoints}} \\ {+ \lambda_{\text{ORH}} \cdot \Pi}_{\text{RH}} \\ + \left( \lambda_{\text{OCaseMech}} + \lambda_{\text{OChipMech}} \right) \cdot \Pi_{\text{Mech}} \\ \end{matrix} \\ \end{pmatrix}_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\end{split}\]

For optocouplers, the basic failure rates \(\lambda_{\text{OTH}}\), \(\lambda_{\text{OTCyChip}}\) and \(\lambda_{\text{OCaseMech}}\) are fixed values depending on the type of components:

Table 3.4.181 Basic failure rates \(\lambda_{\text{OTH}}\), \(\lambda_{\text{OTCyChip}}\) and \(\lambda_{\text{OCaseMech}}\) for optocouplers.#

Component description

\(\lambda_{\text{OTH}}\)

\(\lambda_{\text{OTCyChip}}\)

\(\lambda_{\text{OCaseMech}}\)

Optocoupler with photodiode

0.05

0.01

0.005

Optocoupler with phototransistor

0.11

0.021

0.011

According to the different types of packages defined in Table 3.4.84 to Table 3.4.89, the basic failure rates \(\lambda_{\text{0TcyCase}}\), \(\lambda_{\text{OTCySolderjoints}}\), \(\lambda_{\text{OCaseMech}}\) and \(\lambda_{\text{ORH}}\) are similar to the basic failure rates of packages of integrated circuits available in Table 3.4.90.

Physical stresses for the opto-electronics family:

Equation

(3.4.232)#\[\Pi_{\text{Thermal}} = exp\left\lbrack 11604 \cdot E_{a} \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

\(E_{a}\) = 0.7eV for optocouplers; All other parameters are issued from the mission profile.

Equation

(3.4.233)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.234)#\[\Pi_{\text{TcySolderjoints}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.235)#\[\Pi_{\text{Mechanical}} = \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.236)#\[\Pi_{\text{RH}} = \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.9 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.237)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

The induced factor $C_{\text{sensitivity}} is provided in the following table:

Table 3.4.182 Induced factor coefficient of sensitivity for opto-electronics.#

Technologies

\(C_{\text{sensitivity}}\)

Optocouplers

5.20

Note

For the 2021 issue of FIDES, this value has been updated to 5.63.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.238)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.239)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.183 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for opto-electronics.#

Optocouplers, LEDs: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: AEC Q101, AEC Q102, MIL-PRF-19500 JANS, ESCC 5000, ESCC 5010 level B, NASDA-QTS-xxxx class I, JAXA-QTS Class I (NASDA-QTS-2030)

Higher

3

Qualification according to one of the following standards: MIL-PRF-19500 JANTX or JANTXV, ESCC 5010 level C, NASDA-QTS-xxxx class II, JAXA-QTS Class II

Equivalent

2

Qualification according to one of the following standards: MIL-PRF-19500 JAN or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the Opto-electronics family 18

Section Component types Modifications and adaptations for space applications
18 Optoelectronics

Merge of the models of optocouplers and LEDs

3.4.3.5.16. PCB#

PCB are not classified as family in EPPL but as an important part of electronics units modelling, they are considered in this handbook. They are modelled in FIDES as seen in the following table:

Table 3.4.184 Groups of PCBs.#
Groups of PCBs Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
PCB p155 p173 “Printed circuit board (PCB)” ECPC

General model for the PCB family:

Equation

(3.4.240)#\[\lambda = \lambda_{\text{Physical}} \cdot \Pi_{\text{PM}} \cdot \Pi_{\text{LF}} \cdot \Pi_{\text{Process}}\]
  • \(\lambda_{\text{Physical}}\) the physical contribution for each component,

  • \(\Pi_{\text{PM}}\) the quality and technical control over manufacturing of the item,

  • \(\Pi_{\text{Process}}\) the quality and technical control over the development, manufacturing and use process for the product containing the item,

  • \(\Pi_{\text{LF}}\) the factor representing the process to become lead-free if it has to be considered for Space applications, it is equal to 1 (see Section 3.4.3).

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{Physical}}\)

Equation

(3.4.241)#\[\lambda_{\text{Physical}} = \lambda_{\text{OPCB}} \cdot \sum_{i}^{\text{Phases}}{\frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \Pi_{\text{TCy}} + \Pi_{\text{Mechanical}} + \Pi_{\text{RH}} + \Pi_{\text{Chemical}} \right)_{i}} \cdot \left( \Pi_{\text{induced}} \right)_{i}\]

For space applications, \(\Pi_{\text{Chemical}}\) is equal to 0, \(\Pi_{\text{TV}}\) is equal to 1 because the temperature of the board is always lower than 110°C.

\(\lambda_{\text{OPCB}}\) is issued from the following equation:

Equation

(3.4.242)#\[\lambda_{O_{\text{PCB}}} = 5.10^{- 4} \cdot \left( N_{\text{layers}} \right)^{\frac{1}{2}} \cdot \left( \frac{N_{\text{connection}}}{2} \right) \cdot \Pi_{\text{Class}} \cdot \Pi_{Techno\_ PCB}\]

The value \(\Pi_{Techno\_ PCB}\) reflects the effect on reliability prediction of holes and via on the PCB according to this table:

Table 3.4.185 Values of \(\Pi_{Techno_ PCB}\) depending on the technology of holes and via.#

Printed circuit technology identification

Value of \(\Pi_{Techno\_ PCB}\)

Through holes

0.25

Blind holes

0.5

Micro-via technology

1

Pad on via technology

2.5

In case of mixing technologies of holes and via on the same PCB, the calculation can be done either:

  • by considering the value \(\Pi_{Techno\_ PCB}\) as the maximum value of \(\Pi_{Techno\_ PCB}\) corresponding to each different technology,

  • or by doing a specific calculation of \(\lambda_{\text{OPCB}}\) for each different technology and weighting the results with the area on the PCB of each considered technology.

The value \(\Pi_{\text{Class}}\) reflects the effect on the reliability prediction of the distance between conductors. The table defining this value has been modified with additional values of distance from 800µm to 50µm according to this table:

Table 3.4.186 Values of \(\Pi_{\text{Class}}\) depending on the distance between conductors.#

Minimum conductor width (µm)/ Minimum spacing between conductors or pads (µm)

Value of \(\Pi_{\text{Class}}\)

800 / 800

1

500 / 500

1

310 / 310

2

210 / 210

3

150 / 150

4

125 / 125

5

100 / 100

6

80 / 80

7

70 / 70

8

60 / 60

9

50 / 50

10

Physical stresses for the PCB family:

Equation

(3.4.243)#\[\Pi_{\text{Tcy}} = 0.6 \cdot \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{min(\theta_{\text{cy}},2)}{2} \right)^{\frac{1}{3}} \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{1.9} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

Equation

(3.4.244)#\[\Pi_{\text{Mechanical}} = 0.2 \cdot \left( \frac{G_{\text{rms}}}{0.5} \right)^{1.5}\]

Equation

(3.4.245)#\[\Pi_{\text{RH}} = 0.18 \cdot \left( \frac{\text{RH}_{board\_ ref}}{70} \right)^{4.4} \cdot \ exp\left\lbrack 11604 \cdot 0.8 \cdot \left( \frac{1}{293} - \frac{1}{{273 + T}_{board\_ ref} + \Delta T} \right) \right\rbrack\]

All other parameters are issued from the mission profile.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.246)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The Pi Placement depends on the function, there are 6 choices to choose as recalled here from Table 3.4.3:

Table 3.4.187 Recommendation for the definition of parameter \(\Pi_{\text{placement}_ i}\).#

Description of the placement influence

\(\Pi_{\text{placement}\_ i}\)

Digital non-interface function

1.0

Digital interface function

1.6

Analog low-level non-interface function (<1A)

1.3

Analog low-level interface function (<1A)

2.0

Analog power non-interface function (≥1A)

1.6

Analog power interface function (≥1A)

2.5

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.188 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.189 Induced factor coefficient of sensitivity for PCB.#

Technologies

\(C_{\text{sensitivity}}\)

PCB

6.50

Note

For the 2021 issue of FIDES, this value has been updated to 5.55.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.247)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.248)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 with component quality assurance levels \(\text{QA}_{\text{component}}\) defined in the following tables:

Table 3.4.190 Recommendation for definition of parameter \(\text{QA}_{\text{component}}\) for PCB.#

PCB: Component quality assurance level

Position relative to the state of the art

\(\text{QA}_{\text{component}}\)

Qualification according to one of the following standards: MIL-PRF-31032, MIL-PRF-55110, MIL-PRF-50884, ESCC-Q-ST-70-10, JAXA-QTS-2140

Higher

3

Qualification according to following standard: IPC-9701 with identification of manufacturing sites for these standards

Equivalent

2

Qualification according to one of the following standard: BS CECC 23000, IEC 61189-6 or qualification program internal to the manufacturer and unidentified manufacturing sites

Lower

1

No information

Much

0

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for the PCB family

Section Component types Modifications and adaptations for space applications
NA PCB

Definition of a methodology for mixing technologies of holes and via

Consideration of minimum conductor width from 50 to 800µm

Value of ΠChemical equal to 0

Value of ΠTV equal to 1

3.4.3.5.17. Hybrids (family 40)#

Hybrids are classified as family 40 in EPPL [BR_EEE_9].. They can be modelled with FIDES, as presented in the following table, for FIDES 2009 and 2021.

Table 3.4.191 Groups of Hybrids.#
Groups of Hybrids Models in FIDES 2009 Proposed models in FIDES Remarks
2009 2021
Hybrid p161 p180 Hybrids and Multi Chip Modules Hybrid and multichip module

General model for the Hybrids and Multi Chip Modules family:

Equation

(3.4.249)#\[\lambda_{H\& M} = \sum_{\text{µcomponents}}^{}\left( \lambda_{\text{µcomponent}} \cdot \Pi_{PM_{\text{µcomponent}}} \right) \cdot \Pi_{Process\_ H\& M} \cdot \Pi_{\text{Process}} + \left( \lambda_{\text{wiring}} + \lambda_{Case + Substrate} + \lambda_{External\_ connections} \right) \cdot \Pi_{Process\_ H\& M} \cdot \Pi_{\text{Process}}\]

a) Mission profile

In order to model the reliability for each component of a unit, it is necessary to define the mission profile corresponding to the unit under consideration. See Section 3.4.3.2 for details.

b) Calculation of \(\lambda_{\text{element}}\)

For each basic element (microcomponent, wiring, case-substrate, external connections), the general equation is the standard equation:

Equation

(3.4.250)#\[\lambda_{\text{element}} = \sum_{i}^{\text{Phases}}\left\lbrack \frac{\left( t_{\text{phase}} \right)_{i}}{t_{\text{total}}} \cdot \left( \sum_{\text{stresses}}^{}\left( \lambda_{0stress} \cdot \Pi_{\text{stress}} \right) \right)_{i} \cdot \left( \Pi_{\text{induced}} \right)_{i} \right\rbrack\]

with

Equation

(3.4.251)#\[\lambda_{\text{element}} = \lambda_{\text{µcomponent}}\ \mathrm{\text{or}}\ \lambda_{\text{wiring}}\ \mathrm{\text{or}}\ \lambda_{Case + Substrate}\ \mathrm{\text{or}}\ \lambda_{External\_ connections}\]

For microcomponents associated with bare chips (integrated circuits, transistors or diodes), the failure rate is reduced to:

Equation

(3.4.252)#\[\lambda_{\text{µcomponent}} = \lambda_{\text{Chip}} = \left( \lambda_{\text{OTH}} \cdot \Pi_{\text{Thermique}} \right) + \left( C_{\text{moulding}} \cdot C_{chip\_ area} \cdot \lambda_{0\_ Chip\_ TCy} \cdot \Pi_{TCy\_ case} \right)\]

\(\lambda_{\text{OTH}}\) and \(\Pi_{\text{Thermique}}\) are corresponding to the basic thermal failure rates as defined in the models corresponding to the type of chip considered, either integrated circuits in Section 3.4.3.5.8 or discrete semiconductors in Section 3.4.3.5.4 and Section 3.4.3.5.12;

The factor \(C_{\text{moulding}}\) is defined as follows for chips:

Table 3.4.192 Values of \(C_{\text{moulding}}\) for Hybrids and Multi Chip Modules.#

Type of moulding

\(C_{\text{moulding}}\)

Hermetic non-moulded circuit

1.0

Moulded circuit silicon type embedding

1.4

Moulded circuit polyurethane type embedding

1.6

Moulded circuit epoxy type embedding

2.0

The factor \(C_{chip\_ area}\) is defined as follows for chips:

Equation

(3.4.253)#\[C_{Surface\_ chip} = \left( 1 + S^{d} \right)\]

Table 3.4.193 Values of d for Hybrids and Multi Chip Modules.#

Type of chip

\(d\)

Numeric Si integrated circuits (MOS, Bipolar and BiCMOS)

0.35

Analogue Si integrated circuits (MOS, Bipolar and BiCMOS)

0.2

Discrete circuits

0.1

If the surface of the chip is not known, the following default values are used for the factor \(S\):

Table 3.4.194 Values of \(S\) for Hybrids and Multi Chip Modules.#

Type of chip

\(S\) (mm²)

Logical

75

Analogue

4

Weak signal discrete

0.8

Power discrete

3

The factor \(\lambda_{0T\_chip\_TCy}\) is equal to 0.011 for Hybrids and Multi Chip Modules.

Physical stresses for the Hybrids and Multi Chip Modules family:

Equation

(3.4.254)#\[\Pi_{\text{TcyCase}} = \left( \frac{{12 \cdot N}_{cy\_ phase}}{t_{\text{phase}}} \right) \cdot \left( \frac{\text{ΔT}_{\text{cycling}}}{20} \right)^{4} \cdot exp\left\lbrack 1414 \cdot \left( \frac{1}{313} - \frac{1}{{273 + T}_{max\_ cycling}} \right) \right\rbrack\]

The FIDES guide also gives methods to calculate the failure rates for all kind of micro components inside the Multi Chip Modules, such as resistive networks, resistive SMD chips, deposited resistors, capacitors, and multi-layer inductors. It also gives formula for wiring, case, substrate and external connections.

The chemical factor \(\Pi_{\text{Chemical}}\) is calculated for different pollution levels. However, as the Hybrids and Multi Chip Modules are hermetic in space due to the absence of humidity, the chemical factor \(\Pi_{\text{Chemical}}\) is equal to 0.

Induced factor \(\Pi_{\text{induced}}\)

The \(\Pi_{\text{induced}}\) factor allows taking into account the influence of the mission profile as described in Section 3.4.3.2. Its formula is:

Equation

(3.4.255)#\[\Pi_{\text{induced}\_ i} = \left( \Pi_{\text{placement}\_ i} \cdot \Pi_{\text{application}\_ i} \cdot \Pi_{\text{ruggedising}} \right)^{0.511 \cdot ln(C_{\text{sensitivity}})}\]

\(\Pi_{placement}\)

The placement factor \(\Pi_{placement}\) and induced factors \(C_{\text{sensitivity}}\) are provided in the following tables:

Table 3.4.195 Values of \(\Pi_{placement}\) for Hybrids and Multi Chip Modules.#

Placement of the Hybrids / Multi Chip Modules

\(\Pi_{placement}\)

Digital non-interface function

1.0

Digital interface function

1.3

Analog low-level non-interface function (<1A)

1.2

Analog low-level interface function (<1A)

1.5

Analog power non-interface function (≥1A)

1.3

Analog power interface function (≥1A)

1.8

\(\Pi_{\text{application}}\)

\(\Pi_{\text{application}}\) represents the influence of the type of application and the environment of the product containing the part. This factor varies depending on the phase of the profile.

It is evaluated through the questions presented in the following table and addressed in Section 3.4.3.2.19:

Table 3.4.196 Recommended parameters for \(\Pi_{\text{application}_ i}\) for the launch, time to reach orbit and in-orbit#

Criterion

Description

Levels

Examples and comments

Weight

POS

User type in the phase considered

Represents the capability to respect procedures, facing operational constraints.

0: Favourable

1: Moderate

2: Unfavourable

0: Industry

1: General public

2: Military

The most severe level must be adopted for military applications

20

User qualification level in the phase considered

Represents the level of control of the user or the worker regarding an operational context

0: Favourable

1: Moderate

2: Unfavourable

0: Highly qualified

1: Qualified

2: Slightly qualified or with little experience

In some phases, the user to be considered is the person who does the maintenance or servicing

10

System mobility

Represents contingencies related to possibilities of the system being moved

0:Non aggressive

1: Moderate

2: Severe

0: Few contingencies (fixed or stable environment)

1: Moderate contingencies

2: Severe contingencies, large variability (automobile)

4

Product manipulation

Represents the possibility of false manipulations, shocks, drops, etc .

0:Non aggressive

1: Moderate

2: Severe

0: Not manipulated

1: Manipulation without displacement or disassembly

2: Manipulation with displacement or disassembly

The severe level should be adopted if maintenance on the product is possible in the phase considered

15

Type of electrical network for the system

Represents the level of electrical disturbance expected on power supplies, signals and electrical lines: power on, switching, power supply, connection/disconnection

0:Non aggressive

1: Moderate

2: Severe

0: Undisturbed network (dedicated regulated power supply)

1: Slightly disturbed network

2: Network subject to disturbances (on board network)

The network type is a system data but that can be broken down and related to specific products

4

Product exposure to human activity

Represents exposure to contingencies related to human activity: shock, change in final use, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Uninhabitable zone

1: Possible activity in the product zone

2: Normal activity in the product zone

The product can be exposed to human activity even if it is not handled itself during normal use

8

Product exposure to machine disturbances

Represents contingencies related to operation of machines, engines, actuators: shock, overheating, electrical disturbances, pollutants, etc.

0:Non aggressive

1: Moderate

2: Severe

0: Null (telephone)

1: Indirect exposure (product in compartment)

2: Strong or direct exposure (product in engine area)

3

Product exposure to the weather

Represents exposure to rain, hail, frost, sandstorm, lightning, dust

0:Non aggressive

1: Moderate

2: Severe

0: Null (home)

1: Indirect exposure (compartment, station hall)

2: Outdoors (automobile engine)

2

A mark is given for each level: 1 for level 0, 3.2 for level 1 and 10 for level 2. This mark is multiplied by the weight (\(P_{os}\)) and the sum of all the products is divided by 66. For the present application here, we consider \(\Pi_{\text{application}}\) = 1.1, the value determined in the frame of an Airbus Defence & Space observation project, for all in flight phases.

Note

In bold in the table are the levels considered for the space environment (orbit raising and orbit keeping). They represent the typical environment met in space for satellites, hence the figure can be used for all in flight phases for all projects provided they don’t present a specific application; in that case, it has to be re-evaluated.

\(\Pi_{\text{ruggedising}}\)

The ruggedising factor is determined through a 16 questions audit ensuring the evaluation of the procedures established to guarantee the safety and maintenance of the product and that the procedures are indeed applied. See Section 3.4.3.2.17.

\(C_{\text{sensitivity}}\)

The induced factor \(C_{\text{sensitivity}}\) presented in Section 3.4.3.2.21 is provided in the following table:

Table 3.4.197 Induced factor coefficient of sensitivity for Hybrids and Multi Chip Modules.#

Type of Hybrids / Multi Chip Modules

\(C_{\text{sensitivity}}\)

Metal case, Ceramic case, Ceramic substrate

5.5

Glass-epoxy substrate with moulding

4.1

Glass-epoxy substrate without moulding

4.8

Note

For the 2021 issue of FIDES, these values have not been updated.

c) Component manufacturing factor \(\Pi_{\text{PM}}\)

The Part_Manufacturing factor presented in Section 3.4.3.4 represents the quality of the component. This factor transcribes the confidence that can be attributed to the way the part has been manufactured, through factors quantifying the manufacturing process of the part, the tests ran and the confidence in the manufacturer.

Its high level formula is

Equation

(3.4.256)#\[{\pi_{\text{PM}} = e}^{1.39*\left( 1 - Part_{\text{Grade}} \right) - 0.69}\]

with

(3.4.257)#\[Part\_ Grade = \ \frac{\left( \text{QA}_{\text{manufacturer}} + \text{QA}_{\text{component}} \right) \times \varepsilon}{24}\]

These parameters are determined through tables available in FIDES.

Component manufacturing factor \(\pi_{\text{PM}}\) according to Section 3.4.3.4 and calculated using the calculation method described to determinate the \(\pi_{\text{PM}}\) of the corresponding components (integrated circuits and discrete semiconductors, resistors, capacitors, inductors).

d) Determination of the \(\Pi_{\text{Process}}\) factor

The \(\Pi_{\text{Process}}\) factor is determined according to the formula presented in Section 3.4.3.3.3.

Summary for Hybrids

Section Component types Modifications and adaptations for space applications
40 Hybrids

Value of ΠChemical equal to 0

3.4.3.5.18. Model of COTS boards for space applications#

COTS board are electronic and off-the-shelf boards generally supplied from specific manufacturers with very little to no information provided on their content. These COTS boards are generally designed to perform a generic or standard functionality such as input / output, memory storage, specific signal data processing or communication protocols. For space applications, they are currently only used for on-ground systems. However, with the development of nanosatellites for “new space”, the request to use these boards is increasing to minimize costs and to reduce development time.

There is presently no existing reliability prediction model for COTS boards adapted to space applications. The methodology proposed in the following is based on the data from manufacturer and especially datasheet and parts list of the boards. In case of no information available from the manufacturers, a possible solution is to perform a reverse engineering of the board and to use the families or part count method to estimate the reliability prediction. This method is clearly not recommended. In fact, only life tests on a sufficiently large amount of COTS boards are suitable to estimate the COTS board reliability when no data are available from the manufacturer.

3.4.3.5.19. Reliability prediction of COTS boards done by manufacturers#

Some manufacturers of COTS boards do provide a reliability prediction for their COTS boards and publish this information inside the datasheet. An assessment of this estimation could be made to appreciate its applicability to space applications. Elements, such as the level of confidence, the methodology applied, number of tested boards, number of failed boards and root cause of failure analysis should be provided by the manufacturers of COTS boards to justify their estimations and to provide rationales of their confidence.

3.4.3.5.20. Reliability prediction of COTS boards with raw data provided by manufacturers#

If the manufacturer agrees to provide a datasheet and a parts list, the best solution is to perform a complete reliability calculation with the methodology provided in this handbook based on this data. This data could provide references of the EEE components, manufacturers of the EEE components, and derating computed by the manufacturer. In the unlikely event that the manufacturers fill the Pi Process questionnaire themselves, the resulting Π~Process~ issued from the questionnaire is used to complete the reliability prediction. If not, as it is difficult to fill in the questionnaire for the manufacturer, an alternate solution is to use a recommended value for Π~Process~ of 4.0 if suppliers of COTS boards have no experience with space applications. In case of manufacturers of COTS boards applying the quality process of space industry and having experience with satellites in orbit, this recommended value can be reduced to 2.5. Consequently, it is difficult to justify a value lower than 2.5 without justified rationales from the COTS boards’ manufacturers.

3.4.3.5.21. Reliability prediction of COTS boards without data provided by manufacturers#

Unfortunately, manufacturers of COTS boards usually do not provide any information. One possible solution to overcome this situation is to identify the EEE components of the board and to reconstruct the parts list by reverse engineering, through visual inspection for instance. As it is not possible to identify all characteristics of the components and to estimate the deratings, a simple and fast calculation based on a families count or part count methods is suggested instead of doing a complete part stress calculation.

The families count prediction method considers all the components without distinguishing the different technologies. The part count prediction method considers all types of components with their various technologies. The method for calculating the reliability prediction of COTS boards with the families count and part count method is provided in Section 3.4.3.6.

If it is not possible to apply the families or part count method due to specific concerns such as boards with potting or boards encapsulated in other systems, a reliability prediction based on calculation is not possible. The alternative is to perform the reliability prediction based on life tests of the COTS boards.

The determination of the number of boards to be tested is done from the χ² law:

Equation

(3.4.258)#\[\lambda = \frac{\chi_{2n_{f} + 2,1 - CL}^{2}}{2 \cdot t \cdot AF \cdot n}\]

where:

  • \(\lambda\): objective failure rate of the COTS board in FIT;

  • \(CL\): confidence level in %;

  • \(n_{f}\): number of failed parts;

  • \(t\): test duration in hours;

  • AF: acceleration factor defined depending on the acceleration law;

  • \(n\): quantity of tested parts.

From a fixed failure rate objective \(\lambda\) and with a test with no failure \(n_{f}\)=0, two possible ways to determine the parameters can be followed:

  • If a fixed number of parts \(n\) is available, the test duration \(t\) is determined from the χ² law; by similarity with other industrial domains and to avoid a too long test duration, a minimum of \(n\)=30 parts is requested for the tests;

  • If the test duration \(t\) is fixed, the quantity of parts \(n\) to be tested is determined from the χ² law.

For space applications as for other type of applications, the minimum confidence level to use is 60%. With this confidence level, the test duration can last several years or the quantity of parts to test can be huge. So, there is often a compromise to find in order to get an acceptable quantity of parts to test and an acceptable duration of the test.