IEC 61709:2017

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
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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
...