1、BRITISH STANDARDBS EN 61163-1:2006Reliability stress screening Part 1: Repairable assemblies manufactured in lotsThe European Standard EN 61163-1:2006 has the status of a British StandardICS 31.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59
2、g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 61163-1:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2007 BSI 2007ISBN 978 0 580 54071 4National forewordThis British Stan
3、dard is the UK implementation of EN 61163-1:2006. It is identical to IEC 61163-1:2006. It supersedes BS 5760-16-1:1996 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee DS/1, Dependability and terotechnology, to Subcommittee DS/1/1, Dependability.A list
4、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 responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal o
5、bligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARD EN 61163-1 NORME EUROPENNE EUROPISCHE NORM December 2006 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Norm
6、ung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61163-1:2006 E ICS 03.120.01; 03.120.30; 21.020 English version Reliability stress screening Part 1: Repairable as
7、semblies manufactured in lots (IEC 61163-1:2006) Dverminage sous contraintes Partie 1: Assemblages rparables fabriqus en lots (CEI 61163-1:2006) Zuverlssigkeitsvorbehandlung durch Beanspruchung Teil 1: Instandsetzbare Baugruppen, losweise gefertigt (IEC 61163-1:2006) This European Standard was appro
8、ved by CENELEC on 2006-11-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such natio
9、nal standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language
10、 and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania
11、, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of document 56/1102/FDIS, future edition 2 of IEC 61163-1, prepared by IEC TC 56, Dependability, was submitted to the IEC-CENELEC parallel
12、 vote and was approved by CENELEC as EN 61163-1 on 2006-11-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2007-08-01 latest date by which the national standards conflicti
13、ng with the EN have to be withdrawn (dow) 2009-11-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61163-1:2006 was approved by CENELEC as a European Standard without any modification. _ 2 EN 61163-1:2006 3 CONTENTS INTRODUCTION.6 1 Scope 9 2 Nor
14、mative references .9 3 Terms and definitions .11 4 Symbols .13 5 General description 13 5.1 The reliability stress screening principle.13 5.2 Failure categories15 5.3 Time of occurrence of failures16 6 Planning.16 6.1 Stress conditioning 16 6.2 Evaluation of the failure-free period TM18 6.3 Time gra
15、phs for determination of the failure-free period20 7 Pilot-production screening 25 7.1 General .25 7.2 Collection of information 25 7.3 Evaluation of information .25 7.4 Re-evaluating the failure-free period TM.26 8 Mature production screening.27 8.1 General .27 8.2 Collection of information 27 8.3
16、Evaluation of information .27 8.4 Dealing with discrepancies.27 8.5 Eliminating reliability stress screening29 Annex A (informative) Stress conditions General information .30 Annex B (informative) Stress conditions Temperature 33 Annex C (informative) Stress conditions Vibration and bump37 Annex D (
17、informative) Stress conditions Humidity 43 Annex E (informative) Stress conditions Operational stress46 Annex F (informative) Voltage stress48 Annex G (informative) Highly accelerated stress screening .49 Annex H (informative) Bimodal distributions Weibull plotting and analysis 50 Annex I (informati
18、ve) Evaluation of the failure-free period and the average screening duration56 Annex J (informative) Worked example.66 Annex ZA (normative) Normative references to international publications with their corresponding European publications81 Bibliography .80 EN 61163-1:2006 4 Figure 1 Conceptual diffe
19、rence between reliability screening and growth.7 Figure 2 Typical flow for the design and modifications of reliability stress screening processes for repairable assemblies .8 Figure 3 Typical flow of hardware assemblies from the component manufacturer to the end user .10 Figure 4 Reliability stress
20、screening of repairable assemblies.14 Figure 5 Dependency of categories of failures 16 Figure 6 Elements of stress conditioning 16 Figure 7 Assembly showing screening duration.18 Figure 8 Time graphs for the determination of the failure free period 21 Figure 9 Example of an experimentally determined
21、 Weibull curve that is levelling off at p % failures 26 Figure H.1 The S-curve for a bimodal Weibull distribution mixed by and in the proportions 15 % and 85 %, respectively .51 Figure H.2 Estimation of p, 1 and 1 for the purpose of reliability screening optimization52 Figure H.3 The c.d.f. curves f
22、or bimodal exponential distribution.54 Figure H.4 The hazard rate function for bimodal exponential distribution .55 Figure I.1 The basic system .56 Figure I.2 An assembly surviving the screening period TM with REn remaining weak components .58 Figure I.3 Possible states when a component fails during
23、 the stress screening58 Figure I.4 Assembly states after failure and repair 58 Figure I.5 Time graph for evaluation of the failure-free screening period60 Figures I.6a and I.6b Average screening duration versus the normalized failure-free period F1MmT pc= 0,000 5 and pc= 0,001. 62Figures I.6c and I.
24、6d Average screening duration versus the normalized failure-free period F1MmT pc= 0,002 and pc= 0,005 63Figures I.6e and I.6f Average screening duration versus the normalized failure-free period F1MmT pc= 0,015 and pc= 0,02 64 Figures I.6g and I.6h Average screening duration versus the normalized fa
25、ilure-free period F1MmT pc= 0,03 and pc= 0,04 . 65 Figure J.1 Derivation of the failure-free period TM69 Figure J.2 Derivation of the average screening duration71 Figure J.3 Weibull plot of the observed and predicted failure pattern for the pilot production PBAs.74 11)( = etF5,130- t21)( = etF100060
26、- tEN 61163-1:2006 5 Figure J.4 Weibull plot of relevant failures and predicted S-curve for the pilot production screening 76 Figure J.5 Time graph (corrected) for determination of the failure-free period77 Figure J.6 Time graph (corrected) for evaluation of the screening duration78 Table A.1 Stress
27、 types Indication of cost of application31 Table J.1 Relation between sensitivity of flaws and stresses.68 Table J.2 Observed failure ranks and times to first failure for the pilot production 72 Table J.3 Revised rank values75 EN 61163-1:2006 6 INTRODUCTION Quality control and good design are prereq
28、uisites for reliability. However, in cases where an assembly has an unacceptably low reliability in the early failure period, a reliability screening process may be necessary. An unacceptably low reliability level can be different from one customer to another, or can be based on general market requi
29、rements. Reliability stress screening (RSS) and reliability growth programmes both aim at improvements in the reliability found by the user. However, the two methods are different in principle: a reliability growth programme is a development activity, the purpose of which is to improve the inherent
30、reliability performance of the assemblies by effecting changes to the design (see IEC 61014 and IEC 61164); the purpose of reliability stress screening is to detect and remove flaws; it is part of the production process, and should not be relied upon to reveal inadequacies in design. Furthermore, th
31、e two methods affect the reliability performance differently. This is illustrated in Figure 1. In principle, a reliability screening programme “cuts away“ the early failure period (or part thereof), while a reliability growth programme reduces the overall failure rate level. A reliability growth pro
32、gramme may affect the need for a reliability screening programme if the flaws are of such a nature that they can be prevented from being present at all. The user of this standard should be aware that reliability stress screening does not improve the intrinsic reliability of the assemblies under cons
33、ideration and, where possible, should be made unnecessary by reliability growth programmes and/or quality control. In this standard the term “Item” is used when it is not necessary to distinguish between components, assemblies and system(s). The specific purpose of carrying out a reliability screeni
34、ng process is to detect and remove flaws in hardware assemblies before they reach the customer, or are assembled into higher-level products. This means that, in principle, every hardware assembly under consideration should be included when a reliability screening process is introduced into a product
35、ion process. Reliability screening may cover hardware assemblies of different types and at different levels of the manufacturing process. This standard covers composite items assemblies which are intended to be repaired. Once the allowable fraction of weak assemblies has been specified, the methods
36、in this standard lead to the most economical screening process for assemblies that are manufactured in lots. This is because not all types of assemblies need to be subjected to a reliability screening process. Only the types of assemblies likely to contain flaws should be included. Furthermore, the
37、extent (stress conditions, duration, etc.) to which these selected assembly types will be subjected to screening needs to be minimized. In reliability stress screening the flaws are precipitated into failures by exposure of the assemblies to a suitable stress, for example environmental stress, opera
38、tional stress, or a combination of these. Reliability stress screening is often called environmental stress screening (ESS). EN 61163-1:2006 7 If rogue components are known about and proved to originate in the component manufacturing process, it is much more effective to use screening e.g. burn-in o
39、f the rogue components in question instead of the assembly. However screening a component cannot remove flaws introduced in the assembly process (e.g. soldering, handling (ESD) etc.). The typical steps in a reliability stress screening process are illustrated in Figure 2. Equipment version AFailure
40、pattern beforereliability improvementsare introducedFailure rate0 Time to first failure0 Time to first failureEquipment version AFailure pattern afterreliability screening Failure rateRemaining failures are causedby remaining flaws and systematic weaknessesReliability screening IEC 61163 seriesPart
41、“cut“ awayby reliability screeningApplicable to hardwarecontaining flaws0 Time to first failureEquipment version BFailure pattern beforereliability improvementsare introducedFailure rateRemaining failures are caused by residual weakness (including flaws)Overall level reducedby reliability growthReli
42、ability growth IEC 61014Applicable to hardware and software containingsystematic weaknessesNOTE This standard addresses reliability screening only. For reliability growth see IEC 61014 and IEC 61164. Figure 1 Conceptual difference between reliability screening and growth IEC 1026/06 EN 61163-1:2006
43、8 StartSpecify the maximumallowable fraction of weakassembliesJ.2 step 1Evaluate the actualfraction of weakassembliesJ.2 step 2Is the actual fractionof weak assembliesequal to or lower than thespecified value?NoYesReliability stresssrceening is notnecessary8.5 and J.2 step 2StopPerform the reliabili
44、ty stress screening, collect and analyse the failure informationgenerated6.3, 7, 8 and J.3Design of modify (if necessary)the reliability stressscreening6.2 and J.2 step 3 to step 5Reliability stressscreening is necessaryJ.2 step 21)The result of the analysis of the failure causes may be used in a re
45、liability growth and quality control programme. Figure 2 Typical flow for the design and modifications of reliability stress screening processes for repairable assemblies 1) IEC 1027/06 EN 61163-1:2006 9 RELIABILITY STRESS SCREENING Part 1: Repairable assemblies manufactured in lots 1 Scope This par
46、t of IEC 61163 describes particular methods to apply and optimize reliability stress screening processes for lots of repairable hardware assemblies, in cases where the assemblies have an unacceptably low reliability in the early failure period, and when other methods, such as reliability growth prog
47、rammes and quality control techniques, are not applicable. The reasons for using reliability stress screening may be time constraints and/or the very nature of the deficiencies that the reliability stress screening is designed to catch. The processes apply to any stage of a series production of repa
48、irable assemblies (see Figure 3). The methods for setting up a process can be used during production planning, during pilot-production, as well as during well-established running production. A prerequisite for the application of the methods is that a certain level of flaws remaining in the outgoing
49、assembly can be specified. The processes described are general processes for reliability stress screening in cases where no specific process is described in a product standard. They are also intended for use by IEC committees in connection with preparation of product standards. A reliability stress screening process can form part of an overall reliability programme (see IEC 60300-2). 2 Normative references The following r
