1、Estimation of the reliability of electrical connectors PD IEC/TS 61586:2017 BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06N a t i o n a l f o r e w o r d T h i s P u b l i s h e d D o c u m e n t i s t h e U K i m p l e m e n t a t i o n o f I E C / T S 6 1 5 8 6
2、: 2 0 1 7 . I t s u p e r s e d e s B S I E C 6 1 5 8 6 : 1 9 9 7 w h i c h i s n o w w i t h d r a w n . T h e U K p a r t i c i p a t i o n i n i t s p r e p a r a t i o n w a s e n t r u s t e d t o T e c h n i c a l C o m m i t t e e E P L / 4 8 , E l e c t r o m e c h a n i c a l c o m p o n e
3、n t s a n d m e c h a n i c a l s t r u c t u r e s f o r e l e c t r o n i c e q u i p m e n t . A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are resp
4、onsible for its correct application. The British Standards Institution 2017. Published by BSI Standards Limited 2017 ISBN 978 0 580 85814 7 ICS 29.120.30 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the
5、 Standards Policy and Strategy Committee on 28 February 2017. Amendments/corrigenda issued since publication Date Te x t a f f e c t e d PUBLISHED DOCUMENT PD IEC/TS 61586:2017 IEC TS 61586 Edition 2.0 2017-01 TECHNICAL SPECIFICATION SPECIFICATION TECHNIQUE Estimation of the reliability of electrica
6、l connectors Estimation de la fiabilit des connecteurs lectriques INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE ICS 31.220.10 ISBN 978-2-8322-3816-5 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechn
7、ique Internationale Warning! Make sure that you obtained this publication from an authorized distributor. Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agr. colour inside PD IEC/TS 61586:2017 2 IEC TS 61586:2017 IEC 2017 CONTENTS FOREWORD . 3 INTRODUCTIO
8、N . 5 1 Scope 7 2 Normative references . 7 3 Terms and definitions. 7 4 General considerations 7 4.1 General . 7 4.2 Intrinsic degradation mechanisms 7 4.3 Extrinsic degradation mechanisms 7 4.4 Control of extrinsic degradation . 8 4.5 Failure effects, failure modes and failure (degradation) mechani
9、sms . 8 4.5.1 General 8 4.5.2 Failure modes 8 4.5.3 Degradation mechanisms . 8 5 Test methods and acceleration factors . 9 6 Basic contact and connector reliability testing protocol . 10 7 Reliability statistics 14 7.1 Basic statistical approach to estimating reliability for variables data . 14 7.2
10、Contact vs. connector reliability . 15 7.3 Estimating contact / connector reliability estimates in terms of MTTF/MTBF . 16 8 Acceptance criteria 16 9 Summary and conclusions . 17 Annex A (informative) Determining the stress relaxation acceleration factor for dry heat test conditions . 18 Annex B (in
11、formative) Using extreme value distributions to estimate reliability for multiple position connectors 20 Bibliography 25 Figure B.1 Contact arrangement in a square 16 pole connector. 20 Figure B.2 Largest R values: reference of maximum allowed change 20 m 21 Figure B.3 Largest R values with confiden
12、ce interval for reliability estimates Largest extreme value probability with 90 % confidence interval Sample size = 10 22 Figure B.4 Largest R values with confidence interval for reliability estimates Largest extreme value probability with 90 % confidence interval Sample size = 5 23 Figure B.5 Large
13、st R values with confidence interval for reliability estimates Largest extreme value probability with 90 % confidence interval Sample size = 20 24 PD IEC/TS 61586:2017IEC TS 61586:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ESTIMATION OF THE RELIABILITY OF ELECTRICAL CONNECTORS FOREW
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25、 may propose the publication of a technical specification when the required support cannot be obtained for the publication of an International Standard, despite repeated efforts, or the subject is still under technical development or where, for any other reason, there is the future but no immediate
26、possibility of an agreement on an International Standard. Technical specifications are subject to review within three years of publication to decide whether they can be transformed into International Standards. IEC TS 61586, which is a technical specification, has been prepared by IEC technical comm
27、ittee 48: Electrical connectors and mechanical structures for electrical and electronic equipment. This second edition cancels and replaces the first edition published in 1997. This edition constitutes a technical revision. PD IEC/TS 61586:2017 4 IEC TS 61586:2017 IEC 2017 The main technical changes
28、 with regard to the previous edition are as follows: A specific “basic” testing protocol is defined which utilizes a single test group subjecting connectors to multiple stresses. Additional information is provided concerning test acceleration factors. A discussion of the limitations of providing MTT
29、F/MTBF estimates for connectors has been added. The bibliography has been expanded. The text of this technical specification is based on the following documents: Enquiry draft Report on voting 48/563/DTS 48/568/RVC Full information on the voting for the approval of this technical specification can b
30、e found in the report on voting indicated in the above table. This document has been drafted in accordance with the ISO/IEC Directives, Part 2. The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/web
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32、 contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer. PD IEC/TS 61586:2017IEC TS 61586:2017 IEC 2017 5 INTRODUCTION The reliability of electronic assemblies depends on the reliability of t
33、he passive electrical connections between the active components, as well as on the reliability of the components themselves. There is a common perception that interconnections, specifically connectors, are a major source of failures, often of the “no fault found“ variety, in electronic assemblies. W
34、hether this perception is true is not the subject of this technical document, but connector reliability is a concern. Much of the increasing attention being given to reliability of electrical connectors focuses on the basic question of how the reliability of electrical contacts and connectors can be
35、 meaningfully determined. The definition of reliability which will be assumed in this document is the following: The probability of a product performing a specific function under defined operating conditions for a specified period of time. Reliability is therefore a function of: a) The expected life
36、time of the part. b) The application stresses (electrical, thermal, mechanical, chemical, etc.) the part will be subjected to during its life. c) The specified failure criteria. Since these factors will be different for every application in which the connector may be used, a given connector will hav
37、e a different reliability for every application in which it may be used. Therefore, a connector manufacturer cannot provide a reliability estimate for a contact or connector until the customer has provided a detailed description of the factors listed above for the application in which the connector
38、will be used. To provide a numerical estimate of connector reliability, the manufacturer will then need to use the information provided by the customer to design a test program to simulate the application intended. Some factors which are to be taken into account in addressing this definition are the
39、 subject of this document. The reliability assessment methodology to be discussed centres on appropriate statistical analysis of test data, based on proper consideration of the following issues. d) The active degradation mechanisms are to be identified and categorized by their importance for the app
40、lication. e) Appropriate environmental tests, with cor responding acceleration factors, where practical and appropriate, and exposures, are to be determined for these degradation mechanisms. f) Use of a test sequence which provides an opportunity for the interaction of the potential degradation mech
41、anisms as is necessary to realistically simulate the effects of the expected application. g) The statistical approach to estimating reliability from the test data is to be agreed upon. h) An acceptance criterion appropriate for the application of interest is to be established. Items d), e and f) rel
42、ate to the ability of the product to continue to perform its designated function under the degradation mechanisms it is subjected to in its operating environment. In addition, the need for an acceleration factor is fundamental to assessing the operating life of the product. Item g) is necessary, sin
43、ce the reliability definition is based on probability which requires statistical treatment of appropriate data. Finally, item h) is a result of the fact that the reliability to be assessed is based on the product performing a defined function. The level of knowledge and understanding available to ad
44、dress these issues varies appreciably. Each topic is considered in a separate subclause. PD IEC/TS 61586:2017 6 IEC TS 61586:2017 IEC 2017 It is to be noted that there are a number of other factors w hich have an effect on connector reliability. Among these are: i) the connector manufacturing proces
45、s; j) assembly/application procedures of the equipment manufacturer; k) abuse/misuse of the equipment by the end user. The importance of these application or extrinsic factors cannot be denied and may well be the final determinants of connector reliability. However, extrinsic factors are highly vari
46、able and, therefore, difficult to account for in any estimation of reliability. For these reasons, this document will focus on intrinsic connector reliability, i.e. the reliability of the design/materials of the connector itself as evaluated by the procedures listed previously. This intrinsic reliab
47、ility represents the greatest reliability which the connector can achieve. Th e extrinsic factors will result in a reduction in reliability. It is also to be noted that the approach to reliability estimation in this document differs significantly from that based on a base failure rate which is modif
48、ied by application- specific factors as, for example, in IEC 60863 or MIL Handbook 217. The two approaches are related in that the base failure rate could be determined by a different statistical treatment from the same data which are used in assessing reliability by the method to be discussed. The
49、test environments and exposures would determine the standard conditions which are defined for the base failure rate. In addition, the derating factors used in the failure rate approach can, in principle, be derived from the same data used to determine acceleration factors in the proposed statistical method. The advantage of the approach recommended in this document is that the standard conditions, acceptance criteria, and statistical treatment are specifically defined for the applicati
