IEC 61709:2017

Electric components - Reliability - Reference conditions for failure rates and stress models for conversion

IEC 61709:2017 gives guidance on the use of failure rate data for reliability prediction of electric components used in equipment. The method presented in this document uses the concept of reference conditions which are the typical values of stresses that are observed by components in the majority of applications. Reference conditions are useful since they provide a known standard basis from which failure rates can be modified to account for differences in environment from the environments taken as reference conditions. Each user can use the reference conditions defined in this document or use their own. When failure rates stated at reference conditions are used it allows realistic reliability predictions to be made in the early design phase. The stress models described herein are generic and can be used as a basis for conversion of failure rate data given at these reference conditions to actual operating conditions when needed and this simplifies the prediction approach. Conversion of failure rate data is only possible within the specified functional limits of the components. This document also gives guidance on how a database of component failure data can be constructed to provide failure rates that can be used with the included stress models. Reference conditions for failure rate data are specified, so that data from different sources can be compared on a uniform basis. If failure rate data are given in accordance with this document then additional information on the specified conditions can be dispensed with. This document does not provide base failure rates for components – rather it provides models that allow failure rates obtained by other means to be converted from one operating condition to another operating condition. The prediction methodology described in this document assumes that the parts are being used within its useful life. The methods in this document have a general application but are specifically applied to a selection of component types as defined in Clauses 6 to 20 and I.2. This third edition cancels and replaces the second edition, published in 2011. This edition constitutes a technical revision. This third edition is a merger of IEC 61709:2011 and IEC TR 62380:2004.
This edition includes the following significant technical changes with respect to the previous edition: addition of 4.5 Components choice, 4.6 Reliability growth during the deployment phase of new equipment, 4.7 How to use this document, and of Clause 19 Printed circuit boards (PCB) and Clause 20 Hybrid circuits with respect to IEC TR 62380; addition of failure modes of components in Annex A; modification of Annex B, Thermal model for semiconductors, adopted and revised from IEC TR 62380; modification of Annex D, Considerations on mission profile; modification of Annex E, Useful life models, adopted and revised from IEC TR 62380; revision of Annex F (former B.2.6.4), Physics of failure; addition of Annex G (former Annex C), Considerations for the design of a data base on failure rates, complemented with parts of IEC 60319; addition of Annex H, Potential sources of failure rate data and methods of selection; addition of Annex J, Presentation of component reliability data, based on IEC 60319.
The contents of the corrigendum of October 2019 have been included in this copy.
Keywords: failure rate data, reliability prediction of electric components

Composants électriques - Fiabilité - Conditions de référence pour les taux de défaillance et modèles de contraintes pour la conversion

IEC 61709:2017 donne des recommandations concernant l'utilisation des données de taux de défaillance pour les prévisions de fiabilité de composants électriques utilisés dans les équipements. La méthode exposée dans le présent document utilise le concept des conditions de référence, qui sont les valeurs typiques des contraintes observées sur les composants dans la plupart des applications. Les conditions de référence sont utiles dans la mesure où elles fournissent une base normalisée connue à partir de laquelle les taux de défaillance peuvent être modifiés afin de prendre en compte les différences observées dans l'environnement en fonction des environnements pris comme conditions de référence. Chaque utilisateur peut appliquer les conditions de référence définies dans le présent document ou bien appliquer ses propres conditions de référence. Lorsque les taux de défaillance indiqués dans les conditions de référence sont utilisés, cela permet de réaliser des prévisions de fiabilité réalistes dès la première phase de conception. Les modèles de contraintes décrits dans le présent document sont génériques et peuvent être utilisés comme base de conversion des données de taux de défaillance dans ces conditions de référence, dans des conditions de fonctionnement réelles si nécessaire, ce qui simplifie l'approche prévisionnelle. La conversion des données de taux de défaillance n'est possible que dans les limites de fonctionnement spécifiées pour les composants. Le présent document donne également des recommandations concernant les méthodes pour constituer une base de données de taux de défaillance des composants afin que les taux fournis puissent être employés avec les modèles de contraintes fournis. Les conditions de référence pour les données de taux de défaillance sont définies, de façon à permettre de comparer, dans des conditions uniformes, des données d'origines différentes. Si les données de taux de défaillance sont fournies conformément au présent document, il est possible de se dispenser d'information supplémentaire sur les conditions définies Le présent document ne fournit pas des taux de défaillance de base pour les composants; elle fournit en revanche des modèles qui permettent de convertir les taux de défaillance obtenus par d'autres moyens d’une condition de fonctionnement à l’autre. La méthodologie de prévision décrite dans le présent document pose comme hypothèse l'utilisation des éléments au cours de leur durée de vie. Les méthodes décrites dans le présent document ont une application générale, mais s’appliquent spécifiquement à une sélection de types de composants définis de l’Article 6 à l’Article 20 et en I.2. Cette troisième édition annule et remplace la deuxième édition, parue en 2011. Cette édition constitue une révision technique. Cette troisième édition constitue une fusion entre l’IEC 61709:2011 et l’IEC TR 62380:2004.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente: ajout de 4.5 Choix des composants, 4.6 Croissance de la fiabilité pendant la phase de déploiement du nouvel équipement, 4.7 Méthode d’utilisation du présent document et de l'Article 19 Circuits imprimés (PCB) et de l' Article 20 Circuits hybrides par rapport à l'IEC TR 62380; ajout des modes de défaillance des composants à l’Annexe A; modification de l'Annexe B, Modèle thermique pour semiconducteurs, adoptée de l’IEC TR 62380 et révisée; modification de l'Annexe D, Considérations sur le profil de mission; modification de l'Annexe E, Modèles de durée de vie, adoptée de l’IEC TR 62380 et révisée; révision de l'Annexe F (ancien Paragraphe B.2.6.4), Physique de défaillance; ajout de l'Annexe G (ancienne Annexe C), Considérations sur la conception d’une base de données de taux de défaillance, complétée par des parties de l’IEC 60319; Ajout de l'Annexe H, Sources potentielles de données de taux de défaillance et méthodes de sélection; Ajout de l'Annexe J, Présentation des données de fiabilité des c

General Information

• Status: Published
• Publication Date: 16-Feb-2017
• ICS: 31.020 - Electronic components in general
• Technical Committee: TC 56 - Dependability
• Drafting Committee: MT 18 - TC 56/MT 18
• Current Stage: PPUB - Publication issued
• Start Date: 17-Feb-2017
• Completion Date: 24-Feb-2017

Relations

• Replaces: IEC TR 62380:2004 - Reliability data handbook - Universal model for reliability prediction of electronics components, PCBs and equipment
• Effective Date: 05-Sep-2023
• Corrected By: IEC 61709:2017/COR1:2019 - Corrigendum 1 - Electric components - Reliability - Reference conditions for failure rates and stress models for conversion
• Effective Date: 05-Sep-2023
• Revises: IEC 61709:2011 - Electric components - Reliability - Reference conditions for failure rates and stress models for conversion
• Effective Date: 05-Sep-2023

Overview

IEC 61709:2017 - Electric components - Reliability - Reference conditions for failure rates and stress models for conversion - provides guidance for using failure rate data in the reliability prediction of electric components. Rather than supplying base failure rates, the standard defines a set of reference conditions (typical stress values seen in most applications) and generic stress models to convert failure rates between reference and actual operating conditions. This allows realistic reliability predictions early in the design cycle and enables consistent comparison of data from different sources. Edition 3 (2017) merges IEC 61709:2011 and IEC TR 62380:2004 and includes corrigenda up to October 2019.

Key Topics and Technical Requirements

• Reference conditions: Defined typical environmental and electrical stresses that form a standardized basis for reporting failure rate data.
• Stress models for conversion: Generic factors for voltage, current, temperature, environment, switching rate and other influences (π factors) to convert failure rates from reference to actual conditions.
• Scope limits: Conversion is valid only within specified functional and useful-life limits of components; predictions assume parts are within their useful life.
• Component-specific guidance: Application of the generic models to component families, including integrated circuits, discrete semiconductors, optoelectronics, capacitors, resistors, connectors, relays, PCBs and hybrid circuits (Clauses 6–20 and I.2).
• Supporting annexes: Informative material on failure modes (Annex A), thermal modelling for semiconductors (Annex B), mission profile and useful-life models (Annex D/E), physics of failure, database design and data presentation (Annexes G–J).
• Data handling: Guidance on constructing and selecting a failure rate database and on presenting component reliability data so that failure rate data from different sources are comparable.

Practical Applications

• Early-stage reliability prediction for electronic equipment using component failure rate conversion to actual operating conditions.
• Design trade-offs: Evaluate how operating temperature, voltage stress or environment affect component reliability.
• Database construction: Create standardized failure rate repositories that enable consistent comparisons and conversions.
• Mission/profile analysis: Incorporate duty cycles, dormancy and storage conditions into reliability estimates.
• Reliability growth and deployment: Guidance on modeling reliability improvement during early deployment phases.

Who Should Use This Standard

• Reliability and systems engineers performing failure rate and MTBF calculations
• Component manufacturers and suppliers preparing failure rate data
• Test laboratories and predictive-analytics teams building failure databases
• Procurement, safety and certification personnel who require consistent reliability data

Related Standards (if applicable)

• IEC TR 62380 (merged into this edition)
• IEC 60319 (used for database and data presentation guidance)
• Other IEC reliability and electronic components guidance documents

Keywords: failure rate data, reliability prediction of electric components, reference conditions, stress models, IEC 61709.

Standards Content (Sample)

IEC 61709 ®
Edition 3.0 2017-02
REDLINE VERSION
INTERNATIONAL
STANDARD
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inside
Electric components – Reliability – Reference conditions for failure rates and
stress models for conversion
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IEC 61709 ®
Edition 3.0 2017-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Electric components – Reliability – Reference conditions for failure rates and

stress models for conversion
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.020 ISBN 978-2-8322-3989-6

– 2 – IEC 61709:2017 RLV © IEC 2017
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 12
3 Terms, definitions and symbols . 13
3.1 Terms and definitions. 13
3.2 Symbols . 16
4 Context and conditions . 18
4.1 Failure modes and mechanisms . 18
4.2 Thermal modelling . 19
4.3 Operating Mission profile considerations . 19
4.3.1 General . 19
4.3.2 Operating and non-operating conditions . 19
4.3.3 Dormancy . 20
4.3.4 Storage conditions . 20
4.4 Environmental conditions . 20
4.5 Components choice . 22
4.6 Reliability growth during the deployment phase of new equipment . 23
4.7 How to use this document . 24
5 Generic reference conditions and stress models . 25
5.1 Recommended generic reference conditions . 25
5.2 Generic stress models . 26
5.2.1 General . 26
5.2.2 Stress factor for voltage dependence, π . 27
U
5.2.3 Stress factor for current dependence, π . 27
I
5.2.4 Stress factor for temperature dependence, π . 27
T
5.2.5 Environmental application factor, π . 29
E
5.2.6 Dependence on switching rate, π . 30
S
5.2.7 Dependence on electrical stress, . 30
π
ES
5.2.8 Other factors of influence . 30
6 Integrated semiconductor circuits . 30
6.1 Specific reference conditions . 30
6.2 Specific stress factors models . 33
6.2.1 Models General . 33
6.2.2 Voltage dependence, factor π . 33
U
6.2.3 Temperature dependence, factor π . 33
T
7 Discrete semiconductors . 36
7.1 Specific reference conditions . 36
7.2 Specific stress factors models . 37
7.2.1 General . 37
7.2.2 Voltage dependence for transistors, factor π . 38
U
7.2.3 Temperature dependence, factor π . 38
T
8 Optoelectronic components . 40

8.1 Specific reference conditions . 40
8.2 Specific stress factors models . 42
8.2.1 General . 42
8.2.2 Voltage dependence, factor π . 42
U
8.2.3 Current dependence, factor π . 42
I
8.2.4 Temperature dependence, factor . 43
π
T
9 Capacitors . 45
9.1 Specific reference conditions . 45
9.2 Specific stress factors models . 45
9.2.1 Models General . 45
9.2.2 Voltage dependence, factor π . 45
U
9.2.3 Temperature dependence, factor π . 47
T
10 Resistors and resistor networks . 48
10.1 Specific reference conditions . 48
10.2 Specific stress factors models . 49
10.2.1 Models General . 49
10.2.2 Temperature dependence, factor π . 49
T
11 Inductors, transformers and coils . 50
11.1 Reference conditions . 50
11.2 Specific stress factors models . 50
11.2.1 Models General . 50
11.2.2 Temperature dependence, factor π . 50
T
12 Microwave devices . 51
12.1 Specific reference conditions . 51
12.2 Specific stress factors models . 52
13 Other passive components . 52
13.1 Specific reference conditions . 52
13.2 Specific stress factors models . 52
14 Electrical connections . 52
14.1 Specific reference conditions . 52
14.2 Specific stress factors models . 53
15 Connectors and sockets . 53
15.1 Reference conditions . 53
15.2 Specific stress factors models . 53
16 Relays . 53
16.1 Reference conditions . 53
16.2 Specific stress factors models . 54
16.2.1 Models General . 54
16.2.2 Dependence on switching rate, factor π . 54
S
16.2.3 Dependence on electrical stress, factor π . 55
ES
16.2.4 Temperature dependence, factor π . 56
T
17 Switches and push-buttons . 56
17.1 Specific reference conditions . 56
17.2 Specific stress factors models . 57
17.2.1 Models General . 57

– 4 – IEC 61709:2017 RLV © IEC 2017
Dependence on electrical stress, factor . 57
17.2.2 π
ES
18 Signal and pilot lamps . 58
18.1 Specific reference conditions . 58
18.2 Specific stress factors models . 58
18.2.1 Models General . 58
π
18.2.2 Voltage dependence, factor . 59
U
19 Printed circuit boards (PCB) . 59
20 Hybrid circuits . 59
Annex A (normative) Failure modes of components . 60
Annex B (informative) Thermal model for semiconductors . 63
B.1 Thermal model . 63
B.2 Junction temperature calculation . 64
B.3 Thermal resistance evaluation . 65
B.4 Power dissipation of an integrated circuit P . 66
Annex C (informative) Failure rate prediction . 69
C.1 General . 69
C.2 Failure rate prediction for assemblies . 69
C.2.1 General . 69
C.2.2 Assumptions and limitations . 70
C.2.3 Process for failure rate prediction . 70
C.2.4 Prediction models . 71
C.2.5 Consideration of operating profiles .
C.2.5 Other methods of reliability prediction . 75
C.2.6 Validity considerations of reliability models and predictions . 76
C.3 Component considerations . 76
C.3.1 Component model . 76
C.3.2 Components classification . 76
C.4 General consideration about failure rate . 77
C.4.1 General . 77
C.4.2 General behaviour of the failure rate of components . 77
C.4.3 Expected values of failure rate. 78
C.4.4 Sources of variation in failure rates . 79
Annex D (informative) Considerations on mission profile . 80
D.1 General . 80
D.2 Dormancy . 80
D.3 Mission profile . 81
D.4 Example of mission profile . 82
Annex E (informative) Useful life models . 83
E.1 General . 83
E.2 Power transistors . 83
E.3 Optocouplers . 83
E.3.1 Useful life L . 83
E.3.2 Factor L . 84
E.3.3 Factor κ . 84
E.3.4 Factor κ . 85
E.3.5 Factor κ . 85
E.3.6 Factor κ . 85
E.4 LED and LED modules . 86
E.4.1 Useful life L . 86
E.4.2 Factor L . 86
E.4.3 Factor κ . 87
E.4.4 Factor κ . 87
E.4.5 Factor κ . 88
E.4.6 Factor κ . 88
E.5 Aluminium, non-solid electrolyte capacitors . 88
E.6 Relays . 89
E.7 Switches and keyboards . 89
E.8 Connectors . 89
Annex F (informative) Physics of failure . 90
F.1 General . 90
F.2 Failure mechanisms of integrated circuits . 91
Annex G (informative) Considerations for the design of a data base on failure rates . 92
G.1 General . 92
G.2 Data collection acquisition – collection process . 92
G.3 Which data to collect and how to collect it . 92
G.4 Calculation and decision making . 93
G.5 Data descriptions . 93
G.6 Identification of components . 94
G.6.1 General . 94
G.6.2 Component identification . 94
G.6.3 Component technology . 94
G.7 Specification of components . 94
G.7.1 General . 94
G.7.2 Electrical specification of components . 94
G.7.3 Environmental specification of components . 95
G.8 Field related issues data . 95
G.8.1 General . 95
G.8.2 Actual field conditions . 95
G.8.3 Data on field failures . 95
G.9 Test related issues data . 96
G.9.1 General . 96
G.9.2 Actual test conditions . 96
G.9.3 Data on test failures . 96
G.10 Failure rate database attributes . 97
Annex H (informative) Potential sources of failure rate data and methods of selection . 99
H.1 General . 99
H.2 Data source selection . 99
H.3 User data . 100
H.4 Manufacturer’s data . 100
H.5 Handbook reliability data . 101
H.5.1 General . 101
H.5.2 Using handbook data with this document . 101
H.5.3 List of available handbooks . 102
Annex I (informative) Overview of component classification . 105
I.1 General . 105

– 6 – IEC 61709:2017 RLV © IEC 2017
I.2 The IEC 61360 system . 105
I.3 Other systems. 113
I.3.1 General . 113
I.3.2 NATO stock numbers . 113
I.3.3 UNSPSC codes . 113
I.3.4 STEP/EXPRESS . 113
I.3.5 IECQ . 113
I.3.6 ECALS . 114
I.3.7 ISO 13584 . 114
I.3.8 MIL specifications . 114
Annex J (informative) Presentation of component reliability data . 115
J.1 General . 115
J.2 Identification of components . 115
J.2.1 General . 115
J.2.2 Component identification . 116
J.2.3 Component technology . 116
J.3 Specification of components . 116
J.3.1 General . 116
J.3.2 Electrical specification of components . 116
J.3.3 Environmental specification of components . 116
J.4 Test related issues data . 116
J.4.1 General . 116
J.4.2 Actual test conditions . 117
J.5 Data on test failures . 117
Annex K (informative) Examples . 119
K.1 Integrated circuit . 119
K.2 Transistor . 119
K.3 Capacitor . 119
K.4 Relay . 120
Bibliography . 121

Figure 1 – Comparison of the temperature dependence of π for CMOS IC. 25
T
Figure 2 – Selection of stress regions in accordance with current and voltage-operating
conditions . 55
Figure 3 – Selection of stress regions in accordance with current and voltage-operating
conditions . 57
Figure B.1 – Stress profile .
Figure B.1 – Temperatures inside equipment . 64
Figure B.2 – Averaging failure rates .
Figure B.2 – Thermal resistance model . 65
Figure D.1 – Mission profile . 82

Table 1 – Basic environments . 21
Table 2 – Values of environmental parameters for basic environments . 22
Table 3 – Recommended reference conditions for environmental and mechanical
stresses . 26
Table 4 – Environmental application factor, π . 29
E
Table 5 – Memory . 31
Table 6 – Microprocessors and peripherals, microcontrollers and signal processors . 31
Table 7 – Digital logic families and bus interfaces, bus driver and receiver circuits . 31
Table 8 – Analog ICs . 32
Table 9 – Application-specific ICs (ASICs) . 32
Table 10 – Constants for voltage dependence . 33
Table 11 – Factor for digital CMOS-family ICs. 33
π
U
Table 12 – Factor π for bipolar analog ICs . 33
U
Table 13 – Constants for temperature dependence . 33
Table 14 – Factor π for ICs (without EPROM; FLASH-EPROM; OTPROM; EEPROM;
T
EAROM) . 35
Table 15 – Factor π for EPROM; FLASH-EPROM; OTPROM; EEPROM; EAROM. 35
T
Table 16 – Transistors common, low frequency. 36
Table 17 – Transistors, microwave, (e.g. RF > 800 MHz) . 36
Table 18 – Diodes . 37
Table 19 – Power semiconductors . 37
Table 20 – Constants for voltage dependence of transistors . 38
Table 21 – Factor π for transistors . 38
U
Table 22 – Constants for temperature dependence of discrete semiconductors . 38
Table 23 – Factor for transistors, reference and microwave diodes . 39
π
T
Table 24 – Factor π for diodes (without reference and microwave diodes) and power
T
semiconductors . 39
Table 25 – Optoelectronic semiconductor signal receivers . 40
Table 26 – LEDs, IREDs, laser diodes and transmitter components . 40
Table 27 – Optocouplers and light barriers. 41
Table 28 – Passive optical components . 41
Table 29 – Transceiver, transponder and optical sub-equipment . 41
Table 30 – Constants for voltage dependence of phototransistors . 42
Table 31 – Factor π for phototransistors . 42
U
Table 32 – Constants for current dependence of LEDs and IREDs . 43
π
Table 33 – Factor for LEDs and IREDs. 43
I
Table 34 – Constants for temperature dependence of optoelectronic components . 43
Table 35 – Factor π for optical components . 44
T
Table 36 – Capacitors . 45
Table 37 – Constants for voltage dependence of capacitors . 46
Table 38 – Factor π for capacitors . 46
U
Table 39 – Constants for temperature dependence of capacitors . 47
Table 40 – Factor π for capacitors . 48
T
Table 41 – Resistors and resistor networks . 49
Table 42 – Constants for temperature dependence of resistors . 49
Table 43 – Factor π for resistors . 50
T
– 8 – IEC 61709:2017 RLV © IEC 2017
Table 44 – Inductors, transformers and coils . 50
Table 45 – Constants for temperature dependence of inductors, transformers and coils . 50
Table 46 – Factor for inductors, transformers and coils . 51
π
T
Table 47 – Microwave devices . 51
Table 48 – Other passive components . 52
Table 49 – Electrical connections. 53
Table 50 – Connectors and sockets . 53
Table 51 – Relays . 54
Table 52 – Factor π for low current relays . 55
ES
Table 53 – Factor π for general purpose relays . 55
ES
Table 54 – Factor π for automotive relays . 56
ES
Table 55 – Constants for temperature dependence of relays . 56
Table 56 – Factor π for relays . 56
T
Table 57 – Switches and push-buttons . 57
Table 58 – Factor π for switches and push-buttons for low electrical stress . 58
ES
Table 59 – Factor π for switches and push-buttons for higher electrical stress . 58
ES
Table 60 – Signal and pilot lamps . 58
π
Table 61 – Factor for signal and pilot lamps . 59
U
Table A.1 – Failure modes: ICs (digital) . 60
Table A.2 – Failure modes: transistors, diodes, optocouplers . 61
Table A.3 – Failure modes: LEDs . 61
Table A.4 – Failure modes: laser diodes and modules . 61
Table A.5 – Failure modes: photodiodes and receiver modules . 61
Table A.6 – Failure modes: capacitors . 62
Table A.7 – Failure modes: Resistors, inductive devices, relays . 62
Table B.1 – Thermal resistance as a function of package type, pin number and airflow
factor . 66
v
Table B.2 – Typical values of are K . 66
Table B.3 – Values of P and P . 67
DC f
Table E.1 – Useful life limitations for switches and keyboards . 89
Table F.1 – Failure mechanism for Integrated circuits . 91
Table G.1 – Reliability prediction database attributes . 98
Table H.1 – Result of calculation for transistors common, low frequency. 102
Table H.2 – Sources of reliability data (in alphabetical order) . 102
Table I.1 – Classification tree (IEC 61360-4) . 106

INTERNATIONAL ELECTROTECHNICAL COMMISSION
_______________
ELECTRIC COMPONENTS –
RELIABILITY –
REFERENCE CONDITIONS FOR FAILURE RATES
AND STRESS MODELS FOR CONVERSION

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– 10 – IEC 61709:2017 RLV © IEC 2017
International Standard IEC 61709 has been prepared by IEC technical committee 56:
Dependability.
This third edition cancels and replaces the second edition, published in 2011. This edition
constitutes a technical revision. This third edition is a merger of IEC 61709:2011 and
IEC TR 62380:2004.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of 4.5 Components choice, 4.6 Reliability growth during the deployment phase of
new equipment, 4.7 How to use this document, and of Clause 19 Printed circuit boards
(PCB) and Clause 20 Hybrid circuits with respect to IEC TR 6
...

IEC 61709 ®
Edition 3.0 2017-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric components – Reliability – Reference conditions for failure rates and
stress models for conversion
Composants électriques – Fiabilité – Conditions de référence pour les taux de
défaillance et modèles de contraintes pour la conversion

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IEC 61709 ®
Edition 3.0 2017-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric components – Reliability – Reference conditions for failure rates and

stress models for conversion
Composants électriques – Fiabilité – Conditions de référence pour les taux de

défaillance et modèles de contraintes pour la conversion

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.020 ISBN 978-2-8322-3902-5

– 2 – IEC 61709:2017 © IEC 2017
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 12
3 Terms, definitions and symbols . 12
3.1 Terms and definitions. 12
3.2 Symbols . 16
4 Context and conditions . 17
4.1 Failure modes and mechanisms . 17
4.2 Thermal modelling . 18
4.3 Mission profile consideration . 18
4.3.1 General . 18
4.3.2 Operating and non-operating conditions . 18
4.3.3 Dormancy . 19
4.3.4 Storage . 19
4.4 Environmental conditions . 19
4.5 Components choice . 21
4.6 Reliability growth during the deployment phase of new equipment . 22
4.7 How to use this document . 23
5 Generic reference conditions and stress models . 24
5.1 Recommended generic reference conditions . 24
5.2 Generic stress models . 25
5.2.1 General . 25
5.2.2 Stress factor for voltage dependence, π . 26
U
5.2.3 Stress factor for current dependence, π . 26
I
5.2.4 Stress factor for temperature dependence, π . 26
T
5.2.5 Environmental application factor, π . 28
E
5.2.6 Dependence on switching rate, π . 28
S
5.2.7 Dependence on electrical stress, . 29
π
ES
5.2.8 Other factors of influence . 29
6 Integrated semiconductor circuits . 29
6.1 Specific reference conditions . 29
6.2 Specific stress models . 31
6.2.1 General . 31
6.2.2 Voltage dependence, factor . 32
π
U
6.2.3 Temperature dependence, factor . 32
π
T
7 Discrete semiconductors . 35
7.1 Specific reference conditions . 35
7.2 Specific stress models . 36
7.2.1 General . 36
7.2.2 Voltage dependence for transistors, factor π . 37
U
7.2.3 Temperature dependence, factor π . 37
T
8 Optoelectronic components . 39

8.1 Specific reference conditions . 39
8.2 Specific stress models . 41
8.2.1 General . 41
8.2.2 Voltage dependence, factor π . 41
U
8.2.3 Current dependence, factor π . 41
I
8.2.4 Temperature dependence, factor π . 42
T
9 Capacitors . 44
9.1 Specific reference conditions . 44
9.2 Specific stress model . 44
9.2.1 General . 44
9.2.2 Voltage dependence, factor π . 44
U
9.2.3 Temperature dependence, factor π . 46
T
10 Resistors and resistor networks . 47
10.1 Specific reference conditions . 47
10.2 Specific stress models . 48
10.2.1 General . 48
10.2.2 Temperature dependence, factor π . 48
T
11 Inductors, transformers and coils . 49
11.1 Reference conditions . 49
11.2 Specific stress model . 49
11.2.1 General . 49
11.2.2 Temperature dependence, factor π . 49
T
12 Microwave devices . 50
12.1 Specific reference conditions . 50
12.2 Specific stress models . 51
13 Other passive components . 51
13.1 Specific reference conditions . 51
13.2 Specific stress models . 51
14 Electrical connections . 51
14.1 Specific reference conditions . 51
14.2 Specific stress models . 52
15 Connectors and sockets . 52
15.1 Reference conditions . 52
15.2 Specific stress models . 52
16 Relays . 52
16.1 Reference conditions . 52
16.2 Specific stress models . 53
16.2.1 General . 53
16.2.2 Dependence on switching rate, factor π . 53
S
16.2.3 Dependence on electrical stress, factor π . 54
ES
16.2.4 Temperature dependence, factor π . 55
T
17 Switches and push-buttons . 55
17.1 Specific reference conditions . 55
17.2 Specific stress model . 56
17.2.1 General . 56

– 4 – IEC 61709:2017 © IEC 2017
17.2.2 Dependence on electrical stress, factor π . 56
ES
18 Signal and pilot lamps . 57
18.1 Specific reference conditions . 57
18.2 Specific stress model . 57
18.2.1 General . 57
18.2.2 Voltage dependence, factor π . 58
U
19 Printed circuit boards (PCB) . 58
20 Hybrid circuits . 58
Annex A (normative) Failure modes of components . 59
Annex B (informative) Thermal model for semiconductors . 62
B.1 Thermal model . 62
B.2 Junction temperature calculation . 63
B.3 Thermal resistance evaluation . 64
B.4 Power dissipation of an integrated circuit P . 65
Annex C (informative) Failure rate prediction . 68
C.1 General . 68
C.2 Failure rate prediction for assemblies . 68
C.2.1 General . 68
C.2.2 Assumptions and limitations . 69
C.2.3 Process for failure rate prediction . 69
C.2.4 Prediction models . 70
C.2.5 Other methods of reliability prediction . 71
C.2.6 Validity considerations of reliability models and predictions . 72
C.3 Component considerations . 73
C.3.1 Component model . 73
C.3.2 Components classification . 73
C.4 General consideration about failure rate . 73
C.4.1 General . 73
C.4.2 General behaviour of the failure rate of components . 74
C.4.3 Expected values of failure rate. 75
C.4.4 Sources of variation in failure rates . 75
Annex D (informative) Considerations on mission profile . 77
D.1 General . 77
D.2 Dormancy . 77
D.3 Mission profile . 78
D.4 Example of mission profile . 79
Annex E (informative) Useful life models . 80
E.1 General . 80
E.2 Power transistors . 80
E.3 Optocouplers . 80
E.3.1 Useful life L . 80
E.3.2 Factor L . 81
E.3.3 Factor κ . 81
E.3.4 Factor κ . 82
E.3.5 Factor κ . 82
E.3.6 Factor κ . 82
E.4 LED and LED modules . 83

E.4.1 Useful life L . 83
E.4.2 Factor L . 83
E.4.3 Factor κ . 84
E.4.4 Factor κ . 84
E.4.5 Factor κ . 85
E.4.6 Factor κ . 85
E.5 Aluminium, non-solid electrolyte capacitors . 85
E.6 Relays . 86
E.7 Switches and keyboards . 86
E.8 Connectors . 86
Annex F (informative) Physics of failure . 87
F.1 General . 87
F.2 Failure mechanisms of integrated circuits . 88
Annex G (informative) Considerations for the design of a data base on failure rates . 89
G.1 General . 89
G.2 Data collection acquisition – collection process . 89
G.3 Which data to collect and how to collect it . 89
G.4 Calculation and decision making . 90
G.5 Data descriptions . 90
G.6 Identification of components . 90
G.6.1 General . 90
G.6.2 Component identification . 91
G.6.3 Component technology . 91
G.7 Specification of components . 91
G.7.1 General . 91
G.7.2 Electrical specification of components . 91
G.7.3 Environmental specification of components . 92
G.8 Field related issues data . 92
G.8.1 General . 92
G.8.2 Actual field conditions . 92
G.8.3 Data on field failures . 92
G.9 Test related issues data . 93
G.9.1 General . 93
G.9.2 Actual test conditions . 93
G.9.3 Data on test failures . 93
G.10 Failure rate database attributes . 94
Annex H (informative) Potential sources of failure rate data and methods of selection . 96
H.1 General . 96
H.2 Data source selection . 96
H.3 User data . 97
H.4 Manufacturer’s data . 97
H.5 Handbook reliability data . 98
H.5.1 General . 98
H.5.2 Using handbook data with this document . 98
H.5.3 List of available handbooks . 99
Annex I (informative) Overview of component classification . 102
I.1 General . 102
I.2 The IEC 61360 system . 102

– 6 – IEC 61709:2017 © IEC 2017
I.3 Other systems. 110
I.3.1 General . 110
I.3.2 NATO stock numbers . 110
I.3.3 UNSPSC codes . 110
I.3.4 STEP/EXPRESS . 110
I.3.5 IECQ . 110
I.3.6 ECALS . 111
I.3.7 ISO 13584 . 111
I.3.8 MIL specifications . 111
Annex J (informative) Presentation of component reliability data . 112
J.1 General . 112
J.2 Identification of components . 112
J.2.1 General . 112
J.2.2 Component identification . 113
J.2.3 Component technology . 113
J.3 Specification of components . 113
J.3.1 General . 113
J.3.2 Electrical specification of components . 113
J.3.3 Environmental specification of components . 113
J.4 Test related issues data . 113
J.4.1 General . 113
J.4.2 Actual test conditions . 114
J.5 Data on test failures . 114
Annex K (informative) Examples . 116
K.1 Integrated circuit . 116
K.2 Transistor . 116
K.3 Capacitor . 116
K.4 Relay . 117
Bibliography . 118

Figure 1 – Comparison of the temperature dependence of π for CMOS IC. 24
T
Figure 2 – Selection of stress regions in accordance with current and voltage-operating
conditions . 54
Figure 3 – Selection of stress regions in accordance with current and voltage-operating
conditions . 56
Figure B.1 – Temperatures inside equipment . 63
Figure B.2 – Thermal resistance model . 64
Figure D.1 – Mission profile . 79

Table 1 – Basic environments . 20
Table 2 – Values of environmental parameters for basic environments . 21
Table 3 – Recommended reference conditions for environmental and mechanical
stresses . 25
Table 4 – Environmental application factor, π . 28
E
Table 5 – Memory . 30
Table 6 – Microprocessors and peripherals, microcontrollers and signal processors . 30
Table 7 – Digital logic families and bus interfaces, bus driver and receiver circuits . 30

Table 8 – Analog ICs . 31
Table 9 – Application-specific ICs (ASICs) . 31
Table 10 – Constants for voltage dependence . 32
Table 11 – Factor for digital CMOS-family ICs . 32
π
U
Table 12 – Factor π for bipolar analog ICs . 32
U
Table 13 – Constants for temperature dependence . 32
Table 14 – Factor π for ICs (without EPROM; FLASH-EPROM; OTPROM; EEPROM;
T
EAROM) . 34
Table 15 – Factor π for EPROM; FLASH-EPROM; OTPROM; EEPROM; EAROM. 34
T
Table 16 – Transistors common, low frequency. 35
Table 17 – Transistors, microwave, (e.g. RF > 800 MHz) . 35
Table 18 – Diodes . 36
Table 19 – Power semiconductors . 36
Table 20 – Constants for voltage dependence of transistors . 37
Table 21 – Factor π for transistors . 37
U
Table 22 – Constants for temperature dependence of discrete semiconductors . 37
Table 23 – Factor π for transistors, reference and microwave diodes . 38
T
Table 24 – Factor π for diodes (without reference and microwave diodes) and power
T
semiconductors . 38
Table 25 – Optoelectronic semiconductor signal receivers . 39
Table 26 – LEDs, IREDs, laser diodes and transmitter components . 39
Table 27 – Optocouplers and light barriers. 40
Table 28 – Passive optical components . 40
Table 29 – Transceiver, transponder and optical sub-equipment . 40
Table 30 – Constants for voltage dependence of phototransistors . 41
Table 31 – Factor π for phototransistors . 41
U
Table 32 – Constants for current dependence of LEDs and IREDs . 42
π
Table 33 – Factor for LEDs and IREDs . 42
I
Table 34 – Constants for temperature dependence of optoelectronic components . 42
Table 35 – Factor π for optical components . 43
T
Table 36 – Capacitors . 44
Table 37 – Constants for voltage dependence of capacitors . 45
Table 38 – Factor π for capacitors . 45
U
Table 39 – Constants for temperature dependence of capacitors . 46
Table 40 – Factor π for capacitors . 47
T
Table 41 – Resistors and resistor networks . 48
Table 42 – Constants for temperature dependence of resistors . 48
Table 43 – Factor π for resistors . 49
T
Table 44 – Inductors, transformers and coils . 49
Table 45 – Constants for temperature dependence of inductors, transformers and coils . 49
Table 46 – Factor π for inductors, transformers and coils . 50
T
– 8 – IEC 61709:2017 © IEC 2017
Table 47 – Microwave devices . 50
Table 48 – Other passive components . 51
Table 49 – Electrical connections. 52
Table 50 – Connectors and sockets . 52
Table 51 – Relays . 53
Table 52 – Factor for low current relays . 54
π
ES
Table 53 – Factor π for general purpose relays . 54
ES
Table 54 – Factor π for automotive relays . 55
ES
Table 55 – Constants for temperature dependence of relays . 55
Table 56 – Factor π for relays . 55
T
Table 57 – Switches and push-buttons . 56
Table 58 – Factor for switches and push-buttons for low electrical stress . 57
π
ES
Table 59 – Factor π for switches and push-buttons for higher electrical stress . 57
ES
Table 60 – Signal and pilot lamps . 57
π
Table 61 – Factor for signal and pilot lamps . 58
U
Table A.1 – Failure modes: ICs (digital) . 59
Table A.2 – Failure modes: transistors, diodes, optocouplers . 60
Table A.3 – Failure modes: LEDs . 60
Table A.4 – Failure modes: laser diodes and modules . 60
Table A.5 – Failure modes: photodiodes and receiver modules . 60
Table A.6 – Failure modes: capacitors . 61
Table A.7 – Failure modes: resistors, inductive devices, relays . 61
Table B.1 – Thermal resistance as a function of package type, pin number and airflow
factor . 65
Table B.2 – Typical values of v are K . 65
Table B.3 – Values of P and P . 66
DC f
Table E.1 – Useful life limitations for switches and keyboards . 86
Table F.1 – Failure mechanism for Integrated circuits . 88
Table G.1 – Reliability prediction database attributes . 95
Table H.1 – Result of calculation for transistors common, low frequency. 99
Table H.2 – Sources of reliability data (in alphabetical order) . 99
Table I.1 – Classification tree (IEC 61360-4) . 103

INTERNATIONAL ELECTROTECHNICAL COMMISSION
_______________
ELECTRIC COMPONENTS –
RELIABILITY –
REFERENCE CONDITIONS FOR FAILURE RATES
AND STRESS MODELS FOR CONVERSION

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