1、BSI Standards PublicationEnvironmental acceptance requirements for tin whisker susceptibility of tin and tin alloy surface finishes on semiconductor devicesBS IEC 62483:2013National forewordThis British Standard is the UK implementation of IEC 62483:2013.It supersedes DD IEC/PAS 62483:2006 which is
2、withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/47, Semiconductors.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users
3、are responsible for its correct application. The British Standards Institution 2013Published by BSI Standards Limited 2013ISBN 978 0 580 78828 4ICS 31.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theS
4、tandards Policy and Strategy Committee on 31 October 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS IEC 62483:2013IEC 62483 Edition 1.0 2013-09 INTERNATIONAL STANDARD NORME INTERNATIONALE Environmental acceptance requirements for tin whisker susceptibility of
5、 tin and tin alloy surface finishes on semiconductor devices Exigences de rception environnementale pour la susceptibilit des finis de surface en tain et alliage dtain la trichite dtain sur les dispositifs semiconducteurs INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNAT
6、IONALE X ICS 31.080.01 PRICE CODE CODE PRIX ISBN 978-2-8322-1103-8 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warning! Make sure that you obtained this publication from an authorized distributor. Attention! Veui
7、llez vous assurer que vous avez obtenu cette publication via un distributeur agr. colourinsideBS IEC 62483:2013 2 62483 IEC:2013 CONTENTS 1 Scope . 8 2 Terms and definitions . 8 3 Test method for measuring tin whisker growth 14 3.1 Procedure . 14 3.2 Test samples . 14 3.3 Handling precaution 15 3.4
8、Reflow assembly . 15 4 Acceptance procedure for tin and tin alloy surface finishes . 16 4.1 Determination of whether a technology, manufacturing process, or similarity acceptance test is required 16 4.2 Samples 22 4.2.1 Sample requirements . 22 4.2.2 Sample size for multi-leaded components with 5 or
9、 more leads . 22 4.2.3 Sample size for passive and discrete components with 4 leads or fewer . 22 4.2.4 Additional samples 22 4.3 Test procedures and durations 23 4.3.1 Preconditioning 23 4.3.2 Test conditions 24 4.3.3 Test durations . 24 4.3.4 Whisker inspection 24 4.3.5 Surface corrosion observed
10、during high temperature/humidity testing 24 4.4 Determination of the class level for testing 27 5 Acceptance criteria . 28 5.1 General . 28 5.2 Through-hole lead termination exclusions 28 6 Reporting of results 29 6.1 General requirements 29 6.2 Description of the surface finish, defined by technolo
11、gy and process parameters in Table 2 . 30 6.3 Samples and preconditioning . 30 6.4 Acceptance testing 30 7 On-going tin whisker evaluation 30 Annex A (normative) Test method for measuring whisker growth on tin and tin alloy surface finishes of semiconductor devices 32 A.1 Overview . 32 A.2 Disclaime
12、r . 32 A.3 Apparatus 34 A.3.1 Temperature cycling chambers 34 A.3.2 Temperature humidity chambers 34 A.3.3 Optical stereomicroscope (optional) . 34 A.3.4 Optical microscope (optional) 34 A.3.5 Scanning electron microscope . 34 A.3.6 Convection reflow oven (optional) 34 A.4 Validation of optical micr
13、oscopy equipment . 35 A.4.1 Overall criteria . 35 A.4.2 Capability of whisker detection 35 BS IEC 62483:201362483 IEC:2013 3 A.4.3 Capability of whisker length measurement . 36 A.4.4 Capability of whisker density measurement . 36 A.5 Sample requirements and optional preconditioning 36 A.5.1 Acceptan
14、ce requirements 36 A.5.2 Scientific studies . 37 A.5.3 Test coupons . 37 A.5.4 Optional test sample preconditioning . 37 A.6 Whisker inspection, length measurement and test conditions 39 A.6.1 General principles . 39 A.6.2 Handling 39 A.6.3 General inspection instructions 39 A.6.4 Initial pretest in
15、spection . 40 A.6.5 Test conditions 40 A.6.6 Screening inspection . 41 A.6.7 Detailed inspection 41 A.6.8 Recording procedure for scientific studies . 43 Figure 1 Cross-sectional view of component surface finishes . 8 Figure 2 Typical photographs of termination corrosion . 10 Figure 3 Examples of ti
16、n whiskers 12 Figure 4 Non-whisker surface formations . 13 Figure 5 Whisker length measurement . 13 Figure 6 Minimum lead-to-lead gap 14 Figure 7 Flowchart to determine whether a technology acceptance test, a manufacturing process acceptance test or no testing is required on the basis of similarity
17、. 17 Figure 8 Technology acceptance test flow for multi-leaded components using copper alloy leadframe with post bake mitigation technology Surface finish test sample, technology parameters fixed (1 of 2) . 18 Figure A.1 Process flow for Sn whisker testing . 33 Figure A.2 Optional preconditioning re
18、flow profile 39 Figure A.3 Examples of whiskers in areas of corrosion 40 Figure A.4 A schematic diagram depicting a component lead and the top, 2 sides, and bends of the lead to be inspected . 42 Figure A.5 A schematic drawing depicting a leadless component and the top and 3 sides of the termination
19、s to be inspected 42 Figure A.6 A schematic drawing depicting one possible coupon and three 1,7 mm2areas identified for inspection . 42 Table 1 SMT board assembly process guidance for minimum termination wettingb. 16 Table 2 Surface finish technology and manufacturing process change acceptance param
20、eters . 20 Table 3 Tin and tin alloy surface finish acceptance test matrix . 21 Table 4 Tin and tin alloy surface finish acceptance test sample size requirements per precondition treatment for multi-leaded component . 23 Table 5 Tin and tin alloy surface finish acceptance test sample size requiremen
21、ts per precondition treatment for passive and discrete components with 4 leads or fewer . 23 Table 6 Technology acceptance tests and durations 25 BS IEC 62483:2013 4 62483 IEC:2013 Table 7 Manufacturing process change acceptance tests and durations . 26 Table 8 Preconditioning for technology/ manufa
22、cturing process change acceptance testing 27 Table 9 Technology acceptance criteria for maximum allowable tin whisker length. 29 Table 10 Manufacturing process change acceptance criteria for maximum allowable tin whisker length 29 Table A.1 Test sample size requirements per precondition treatment fo
23、r coupons 37 Table A.2 Optional preconditioning treatments for tin whisker test samples 38 Table A.3 Optional preconditioning reflow profiles a. 38 Table A.4 Tin whisker test conditions . 40 Table A.5 Tin whisker tests standard report formats (general information) . 43 Table A.6 Tin whisker tests st
24、andard report formats (detailed whisker information) 45 Table A.7 Whisker density ranges that can be determined based on the number of whiskers observed per lead, termination, or coupon area 46 BS IEC 62483:201362483 IEC:2013 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ENVIRONMENTAL ACCEPTANCE REQ
25、UIREMENTS FOR TIN WHISKER SUSCEPTIBILITY OF TIN AND TIN ALLOY SURFACE FINISHES ON SEMICONDUCTOR DEVICES FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The o
26、bject of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifica
27、tions (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations lia
28、ising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters expre
29、ss, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committ
30、ees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National
31、 Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not
32、 provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have th
33、e latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever
34、, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications
35、 is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard I
36、EC 62483 has been prepared by IEC technical committee 47: Semiconductor devices. This first edition is based on JEDEC documents JESD201A and JESD22-A121A and replaces IEC/PAS 62483, published in 2006. This first edition constitutes a technical revision. This edition includes the following significan
37、t technical changes with respect to the previous edition: a) The content of IEC/PAS 62483 was added to the content of JESD201A as Annex A. b) A methodology was introduced for environmental acceptance testing of tin-based surface finishes and mitigation practices for tin whiskers. c) A Clause 6 was i
38、ntroduced detailing the reporting requirements of test results. BS IEC 62483:2013 6 62483 IEC:2013 The text of this standard is based on the following documents: FDIS Report on voting 47/2171/FDIS 47/2180/RVD Full information on the voting for the approval of this standard can be found in the report
39、 on voting indicated in the above table. This publication 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 web site under “http:/webstore.iec.ch“ in
40、the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the c
41、orrect understanding of its contents. Users should therefore print this document using a colour printer. BS IEC 62483:201362483 IEC:2013 7 INTRODUCTION Many companies in the electronics industry have adopted tin-based surface finishes as one of the methods to comply with various legislative lead-fre
42、e (Pb-free) initiatives, e.g., the European Unions RoHS directive. However, tin (Sn) and tin alloy surface finishes may be prone to tin whisker formation with associated possible reliability degradation. Appropriate mitigation practices may be incorporated to reduce tin whisker propensity to an acce
43、ptable level. Test conditions in accordance with Annex A and qualification limits presented in this International Standard are based on known Sn whisker data from around the world. These test conditions have not been correlated with longer environmental exposures of components in service. Thus, ther
44、e is at present no way quantitatively to predict whisker lengths over long time periods based on the lengths measured in the short-term tests described in this document. At the time of writing, the fundamental mechanisms of tin whisker growth are not fully understood and acceleration factors have no
45、t been established. Therefore, the testing described in this document does not guarantee that whiskers will or will not grow under field life conditions. BS IEC 62483:2013 8 62483 IEC:2013 ENVIRONMENTAL ACCEPTANCE REQUIREMENTS FOR TIN WHISKER SUSCEPTIBILITY OF TIN AND TIN ALLOY SURFACE FINISHES ON S
46、EMICONDUCTOR DEVICES 1 Scope This International Standard describes the methodology applicable for environmental acceptance testing of tin-based surface finishes and mitigation practices for tin whiskers on semiconductor devices. This methodology may not be sufficient for applications with special re
47、quirements, (i.e. military, aerospace, etc.). Additional requirements may be specified in the appropriate requirements (procurement) documentation. This International Standard does not apply to semiconductor devices with bottom-only terminations where the full plated surface is wetted during assembl
48、y (for example: quad-flat no-leads and ball grid array components, flip chip bump terminations). Adherence to this standard includes meeting the reporting requirements described in Clause 6. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 bas
49、e metal metal alloy residing beneath all surface finish(es) and/or underplate Figure 1 Cross-sectional view of component surface finishes 2.2 tin and tin alloy surface finish tin-based outer surface finish for external component terminations and other exposed metal 2.3 tin whisker mitigation practice process(es) performed during the manufacture of a component to reduce the propensity for tin whisker growth by minimizing the surface finish
