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1、BRITISH STANDARD BS IEC 61163-2:1998 Reliability stress screening Part 2: Electronic components ICS 31.020 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 This British Standard, having been prepared under the direction of
2、 the Management Systems Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 February 1999 BSI 05-1999 ISBN 0 580 30923 1 National foreword This British Standard reproduces verbatim IEC 61163-2:1998 and implements it as the UK national standard.
3、The UK participation in its preparation was entrusted by Technical Committee DS/1, Dependability and terotechnology, to Subcommittee DS/1/1, Dependability, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries
4、 on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. From 1 January 1997, all I
5、EC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references The British Standards
6、 which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard do
7、es not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an ins
8、ide front cover, pages i and ii, the CEI IEC title page, page ii, pages 1 to 24 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication
9、 Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 BSI 05-1999i Contents Page National forewordInside front cover Text of CEI IEC 61163-21 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36
10、 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 ii BSI 05-199
11、9 Contents Page Introduction1 1Scope1 2Normative references1 3Definitions2 4Procedure2 4.1General2 4.2Programme definition4 4.3Establish contact between the two parties involved4 4.4Identify the possible flaws and failure modes for each component4 4.5Select stress types, stress levels and stress seq
12、uence to be used in order to precipitate failures5 4.6Determine the duration of the reliability stress screening process5 4.7Mathematically analyze initial test results5 4.8Perform failure analysis5 4.9Perform stress sequence on the components6 4.10Determine approval or rejection criteria6 4.11Devel
13、op closed-loop corrective action process6 4.12Provide feedback to the component manufacturers6 4.13Discontinue the reliability stress screening process6 Annex A (informative) Examples of tools for identifying failure mechanisms in electronic components8 Annex B (informative) Data analysis10 Annex C
14、(informative) Examples of applications of reliability stress screening processes.18 Figure 1 Component reliability screening process (general flow chart)3 Figure 2 Corrective action process7 Figure B.1 Nomograph of the cumulative binomial distribution (Larson)11 Figure B.2 Estimation of and 13 Figur
15、e B.3 Example of a weibull plot14 Figure C.1 Weibull plot of the bump test22 Figure C.2 Weibull plot of the pull test24 Table A.1 Tools for identifying potential flaws8 Table B.1 Screening test results14 Table B.2 Screening test results for weak populations15 Licensed Copy: sheffieldun sheffieldun,
16、na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 BSI 05-19991 Introduction Although first developed as a tool for designing reliability into systems that operate in harsh environmental conditions, reliability stress screening has emerged as a technique in the el
17、ectrotechnical manufacturing community that is useful if the drive toward zero defect levels in new products is to continue. Reliability stress screening has proved to be an effective tool in a) identifying and removing flaws due to poor component design and manufacturing deficiencies, b) screening
18、parts to a tighter specification than those published, c) providing feedback to enable the streamlining of processes to achieve very tight limits in order to minimize parameter variability. Reliability stress screening should not be considered as a normal procedure to be used in assuring the reliabi
19、lity of electronic components because reliability stress screening cannot improve the reliability of an individual component. Reliability stress screening can, however, improve the actual reliability of a system. The cost and risks generally outweigh the potential benefits since any applied stress m
20、ay have detrimental effects on the lifetime of the components. Greater benefits may be obtainable by tighter manufacturing process control. However, in some cases, this may not be practical, for example with existing components with less than acceptable reliability. Using reliability stress screenin
21、g to upgrade component specifications can also lead to a logistical problem, when similarly screened components are not available at a later date. When performing reliability stress screening on components for use in a particular system, either enough components needed for the repair of the system o
22、ver its entire service life need to be screened initially or the user needs to ensure that system documentation be sufficient to control component procurement so that all replacement components be similarly screened. 1 Scope This part of IEC 61163 provides guidance on reliability stress screening te
23、chniques and procedures for electronic components. This standard is not, and cannot be, exhaustive due to the rapid rate of developments in the electronics industry. This standard is intended for the use of a) component manufacturers as a guideline, b) component users as a guideline to negotiate wit
24、h component manufacturers on stress screening requirements or plan a stress screening process in house due to reliability requirements, c) subcontractors who provide stress screening as a service. This standard is not intended to provide test plans for specific electronic components or for delivery
25、of certificates of conformance for batches of components. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 61163. At the time of publication, the editions indicated were valid. All normative d
26、ocuments are subject to revision, and parties to agreements based on this part of IEC 61163 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standa
27、rds. IEC 60050(191):1990, International Electrotechnical Vocabulary (IEV) Chapter 191: Dependability and quality of service. IEC 60300-1:1993, Dependability management Part 1: Dependability programme management. IEC 60300-2:1995, Dependability management Part 2: Dependability programme elements and
28、tasks. IEC 60300-3-7: , Dependability management Part 3-7: Application guide Reliability stress screening of electronic hardware1). IEC 61163-1:1995, Reliability stress screening Part 1: Repairable items manufactured in lots. IEC 61709:1996, Electronic components Reliability Reference conditions for
29、 failure rates and stress models for conversion. 1) To be published. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 2 BSI 05-1999 3 Definitions For the purpose of this part of IEC 61163, the following definitions as well
30、 as those given in IEC 60050(191) and IEC 60300-3-7 apply: 3.1 reliability screening (process) a process of detection of flaws and removal and repair of weak items for the purpose of reaching as rapidly as possible the reliability level expected during the useful life NOTE 1IEC 60050(191) defines in
31、 191-17-02, the term “burn-in”. This term, however, is used by many manufacturers to describe a so-called “soak-test”, which is only one of many possible ways of screening. Furthermore “burn-in” may include ageing, the purpose of which is to stabilize parameters, and where in many cases no failures
32、occur. NOTE 2IEC 60050(191) defines, in 191-14-09, the term “screening test”. This term, however, is defined too broadly to be applicable in the present context because it encompasses screening of any types of non-conformities. Furthermore, reliability screening is a process, not a test. NOTE 3Repai
33、r is not applicable in the case of electronic components. 3.2 reliability stress screening (process) a process using environmental and/or operational stress as a means of detecting flaws by precipitating them as detectable failures NOTEReliability screening is designed with the intention of precipit
34、ating flaws into detectable failures. An ageing process designed specifically with the intention of stabilizing parameters is not a reliability stress screening process and is therefore outside the scope of this standard. 3.3 weak item an item which has a high probability of failure in the early fai
35、lure period due to a flaw (see also 3.8: early failure period) 3.4 weakness any imperfection (known or unknown) in an item, capable of causing one or more weakness failures NOTE 1Each type of weakness is assumed to be statistically independent of all other such types. NOTE 2A weakness may be either
36、inherent or induced. 3.5 weakness failure a failure due to a weakness in the item itself when subjected to stresses within the stated capabilities of the item IEV 191-04-06 3.6 flaw a weakness in an item which gives rise to early weakness failures 3.7 inherent flaw a flaw in an item related to its t
37、echnology and manufacturing process 3.8 early failure period that early period, if any, in the lifetime of an item, beginning at a given instant of time and during which the instantaneous failure intensity for a repaired item or the instantaneous failure rate for a non-repaired item is considerably
38、higher than that of the subsequent period IEV 191-10-07 NOTEThe early failure period is the period where the weak items fail. 4 Procedure 4.1 General In designing a stress programme, it is important to understand the purpose of the programme as to whether it is: a) to improve the process capability
39、by understanding and eliminating causes of failures; b) to achieve tighter performance on screened devices compared to published specifications; c) to understand and improve reliability of new device technologies; d) to remove weak devices which may fail early. It is important to note that there are
40、 two types of failures: time-dependent failures; the mechanisms that cause these failures are stress-dependent and will cause degradation of the device given sufficient time. The techniques used to accelerate these failure mechanisms should not affect good devices; time-independent failures; these f
41、ailure mechanisms are due to latent flaws that do not affect devices in normal operation unless induced by some external events. Care should be taken when choosing the techniques used to accelerate these failures since damage to good components is possible if the screen is too harsh. In all the abov
42、e cases, the screening will start at 100 %, gradually reduce and finally be eliminated after analysis of failures is made and follow-up actions are taken. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 BSI 05-19993 It is
43、 important that the aim for a reliability stress screening be carefully considered. No reliability stress screening procedure should be used routinely. There is to be a clear reason why reliability stress screening is chosen (for example economic reasons). In order to get the best possible results f
44、rom a stress screen, it is necessary to fully understand the failure mechanisms of the components to be screened and how the application of any particular screen will affect these mechanisms. Care should be taken so that only the failure mechanisms likely to occur while the component is operating in
45、 the field are accelerated by the screen, since it is relatively easy to induce unlikely failure mechanisms by misapplication of screening stress. Before and after any screen is applied, functional testing of each part to be screened should be performed. Firstly, this testing is done so that only th
46、ose parts that fail as a result of the stress screen should be recorded as failing for that reason. Secondly, the stress screen is applied to every component for the specified period of time and under the specified conditions. Thirdly, every component is tested functionally again, in order to remove
47、 any failed parts from the good product population. Functional testing may not be sufficient for components which are particularly delicate or costly, such as lasers. In these cases, a parametric test may be necessary. Figure 1 Component reliability screening process (general flow chart) Licensed Co
48、py: sheffieldun sheffieldun, na, Sun Nov 26 11:53:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61163-2:1998 4 BSI 05-1999 The reliability stress screening performed in this manner can be used to determine the yield of the screen for the lot of components screened. This screen yield data may
49、be compared to data for yield without screen application and both these types of data may be compared in turn to system yield data, and ultimately to system field return data, all in order that the effectiveness of the screen may be monitored. In order to use reliability stress screening of electronic components effectively, the type of failure(s) expected should be understood. Then the details of the stress screen programme, including stress levels and screen durations, should be planned. The reliability stress screening me
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