1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationConnectors for electronic equipment Tests and measurementsPart 16-21: Mechanical tests on contacts and terminations Test 16u: Whisker test via the application of external mechani
2、cal stressesBS EN 60512-16-21:2012National forewordThis British Standard is the UK implementation of EN 60512-16-21:2012. It isidentical to IEC 60512-16-21:2012.The UK participation in its preparation was entrusted to Technical CommitteeEPL/48, Electromechanical components and mechanical structures
3、for electronic equipment.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 of acontract. Users are responsible for its correct application. The British Standards Institution 2012P
4、ublished by BSI Standards Limited 2012ISBN 978 0 580 69264 2ICS 31.220.10 Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 July 2012.Amendments issued since publ
5、icationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60512-16-21:2012EUROPEAN STANDARD EN 60512-16-21 NORME EUROPENNE EUROPISCHE NORM June 2012 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische
6、Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60512-16-21:2012 E ICS 31.220.10 English version Connectors for electronic equipment - Tests and measurements - Pa
7、rt 16-21: Mechanical tests on contacts and terminations - Test 16u: Whisker test via the application of external mechanical stresses (IEC 60512-16-21:2012) Connecteurs pour quipements lectroniques - Essais et mesures - Partie 16-21: Essais mcaniques des contacts et des sorties - Essai 16u: Essai des
8、 trichites au moyen de lapplication de contraintes mcaniques extrieures (CEI 60512-16-21:2012) Steckverbinder fr elektronische Einrichtungen - Mess- und Prfverfahren - Teil 16-21: Mechanische Prfungen an Kontakten und Anschlssen -Prfung 16u: Whisker-Prfung unter Anwendung uerer mechanischer Beanspru
9、chungen(IEC 60512-16-21:2012) This European Standard was approved by CENELEC on 2012-06-11. 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-d
10、ate lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by transl
11、ation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, De
12、nmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60512-16-21:2012EN 60512-16-21:2012 - 2 -
13、 Foreword The text of document 48B/2284/FDIS, future edition 1 of IEC 60512-16-21, prepared by SC 48B “Connectors”, of IEC/TC 48 “Electromechanical components and mechanical structures for electronic equipment“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60512-16-21:
14、2012. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2013-03-11 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2015
15、-06-11 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60512-16-21:2012
16、was approved by CENELEC as a European Standard without any modification. BS EN 60512-16-21:2012- 3 - EN 60512-16-21:2012 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normativel
17、y referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common
18、modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60050-581 - International Electrotechnical Vocabulary (IEV) - Part 581: Electromechanical components for electronic equipment - - IEC 60068-1 - Environmental testing - Part 1: General and guidance EN
19、 60068-1 - IEC 60068-2-58 2004 Environmental testing - Part 2-58: Tests - Test Td: Test methods for solderability, resistance to dissolution of metallization and to soldering heat of surface mounting devices (SMD) EN 60068-2-58 + corr. December 2004 2004 IEC 60068-2-82 + corr. December 2007 2009 Env
20、ironmental testing - Part 2-82: Tests - Test XW1: Whisker test methods for electronic and electric components EN 60068-2-82 2007 IEC 60512-1 - Connectors for electronic equipment - Tests and measurements - Part 1: General EN 60512-1 - IEC 61760-1 2006 Surface mounting technology - Part 1: Standard m
21、ethod for the specification of surface mounting components (SMDs) EN 61760-1 2006 BS EN 60512-16-21:2012 2 60512-16-21 IEC:2012 CONTENTS 1 Scope and object 5 2 Normative references . 5 3 Terms and definitions . 6 4 Test equipment . 6 Optical microscope 6 4.1Scanning electron microscope (SEM) 6 4.25
22、Preparation of the specimens . 6 General . 6 5.1Handling of the specimens 7 5.2Preconditioning . 7 5.36 Measurement of whisker length 7 7 Test method . 8 Initial measurement . 8 7.1Test . 8 7.2General . 8 7.2.1Test conditions 9 7.2.2Accelerated conditions 9 7.2.3Test duration . 9 7.2.4Final measurem
23、ent 9 7.38 Requirements . 9 9 Information to be recorded 9 10 Details to be specified 10 Annex A (informative) Whisker growth due to mechanical stresses induced by assembly processes and intended usage 11 Figure 1 Whisker length . 8 Figure A.1 Filament whisker . 11 Figure A.2 Whisker on contact . 11
24、 Figure A.3 Whisker on FFC 11 Table 1 Preconditioning heat treatment of specimens for whisker test 7 BS EN 60512-16-21:201260512-16-21 IEC:2012 5 CONNECTORS FOR ELECTRONIC EQUIPMENT TESTS AND MEASUREMENTS Part 16-21: Mechanical tests on contacts and terminations Test 16u: Whisker test via the applic
25、ation of external mechanical stresses 1 Scope and object This part of IEC 60512, when required by the detail specification, is used for testing connectors within the scope of IEC technical committee 48. It may also be used for similar devices when specified in a detail specification. The object of t
26、his standard is to define a standard test method to assess the possibility of whisker growth by external mechanical stress on the tin and tin-alloy plated parts of a connector in its application (after wire termination, after soldering, after mounting, mated with counterpart). This standard does not
27、 cover internal stress type whisker. NOTE 1 The test method dealing with internal stress type whisker, which is caused by the formation of intermetallic compound by diffusion, or by the formation of oxide film of the plating surface, or by the difference between coefficients of thermal expansion, is
28、 specified in IEC 60068-2-82. While for internal stress type whisker, it is possible to apply accelerated test conditions, e.g.: by damp heat or temperature cycling, for the external mechanical stress type whisker covered by this standard, due to the different whisker generation mechanism, there are
29、 no accelerated conditions. The test detailed in this standard shall then be conducted under normal ambient conditions. NOTE 2 Physical changes during the application process may cause changes of the material qualities, so that this test cannot be used as a qualification test of a connector in as pr
30、oduced condition. NOTE 3 The conditions specified in this test may accelerate the growth of tin whiskers in a test specimen, but no correlation has been demonstrated between the extent of whisker growth, which may occur in this test, and the extent of whisker growth which may be expected in actual u
31、se. Whisker growth in actual use may therefore be less than or greater than the extent of whisker growth found when using this test. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated r
32、eferences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-581, International Electrotechnical Vocabulary (IEV) Part 581: Electromechanical components for electronic equipment IEC 60068-68-1, Environm
33、ental testing Part 1: General and guidance IEC 60068-2-58: 2004, Environmental testing Part 2-58: Tests Test Td: Test methods for solderability, resistance to dissolution of metallization and to soldering heat of surface mounting devices (SMD) BS EN 60512-16-21:2012 6 60512-16-21 IEC:2012 IEC 60068-
34、2-82:2007, Environmental testing Part 2-82: Tests Test XW1: Whisker test methods for electronic and electric components IEC 60512-1, Connectors for electronic equipment Tests and measurements Part 1: General IEC 61760-1:2006, Surface mounting technology Part 1: Standard method for the specification
35、of surface mounting components (SMDs) 3 Terms and definitions For the purposes of this document, the terms and definitions of IEC 60050-581, IEC 60512-1, IEC 60068-2-82 and the following additional terms and definitions apply. 3.1whisker metallic protrusion, which spontaneously grows from the surfac
36、e of a plating on a base metal during storage and use Note 1 to entry: For the purpose of this standard, whiskers have the following characteristics: an aspect ratio (length/width) greater than 2; straight, kinked, bent and twisted with a uniform cross-sectional shape. 3.2whisker length the straight
37、-line distance from the point of emergence of the whisker to the most distant point on the whisker (i.e., the radius of a sphere containing the whisker with its centre located at the point of emergence.) 4 Test equipment Optical microscope 4.1An optical stereomicroscope with an appropriate illuminat
38、ion and with at least 50X magnification, capable of detecting whiskers with a minimum length of 10 m shall be provided. For the measurement of whisker length, the microscope shall be equipped with a scale or electronic detection system capable of length measurements with accuracy of at least 5 m. Sc
39、anning electron microscope (SEM) 4.2A SEM capable of at least 250X magnification for investigating the surface of the specimen preferably equipped with a handling system for tilting and rotating the specimen shall be provided. 5 Preparation of the specimens General 5.1The number of specimens shall b
40、e specified in the detail specification or in accordance with IEC 60068-2-82. The specimens shall be directly collected from the manufacturing line. BS EN 60512-16-21:201260512-16-21 IEC:2012 7 The specimens shall be prepared as they are intended to be used in final application. The specimens may ad
41、ditionally require special processing to allow observation of whisker growth, if any, inside the specimens, without affecting the primary function of the connector. Each test shall be performed independently on separate specimens. Handling of the specimens 5.2When handling the specimens, care shall
42、be taken to prevent contamination, external mechanical stress or unexpected damage. In addition, care shall be taken to prevent whisker falling off. Preconditioning 5.3Unmated specimens shall be subjected to heat treatment. Table 1 shows specimens preconditioning heat treatments required before whis
43、ker growth test of Clause 7. After heat treatment, the specimens shall be placed under standard atmospheric conditions for at least 1 h, as specified in IEC 60068-1 to proceed to the next test. While handling specimens, care shall be taken in order to avoid contamination of any soldering area by con
44、tact with naked hand or other objects. Table 1 Preconditioning heat treatment of specimens for whisker test Specimen Heat treatment Remarks SMTaand THRbconnectors Test 1 or test 2 in Table 4 of IEC 60068-2-58 The used reflow profile should be less than the maximum limited reflow profile described in
45、 Table 4 of IEC 60068-2-58 Connectors with dip-solder contacts or for handmade soldering 6.1 of IEC 61760-1, using SnAgCu solder The used soldering profile should be less than the maximum limited soldering profile described in 6.1 of IEC 61760-1 Connectors with solderless contacts Not applicable aSM
46、T: Surface Mount Technology. bTHR: Through Hole Reflow. 6 Measurement of whisker length The whisker length shall be measured according to the following procedure. a) The specimen shall be placed on the stage of the optical microscope according to 4.1. b) The specimen shall be observed as shown in An
47、nex A at an appropriate magnification. c) The length of the whisker shall be measured according to Figure 1. BS EN 60512-16-21:2012 8 60512-16-21 IEC:2012 Whisker Whisker length Figure 1 Whisker length NOTE The length of whisker shall be measured according to its definition given in 3.2, by the stra
48、ight-line distance from the point of emergence of the whisker to the most distant point on the whisker (i.e., the radius of a sphere containing the whisker with its centre located at the point of emergence). For detailed observation, SEM should be used. For SEM observation, low accelerating voltage
49、shall be applied to avoid melting and disappearance of thin whiskers. 7 Test method Initial measurement 7.1Specimens shall be examined for the presence of tin whiskers using an optical microscope. The length of each whisker identified shall be measured according to Clause 6. The number of whiskers with a length as specified in the detail specification shall be recorded according to Clause 10. For detailed measurement, SEM should be used. Test 7.2General 7.2.1Test shall b
