1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Environmental testingPart 2-20: Tests Test T:Test methods for solderabilityand resistance to solderingheat of dev
2、ices with leadsBS EN 60068-2-20:2008NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LANational forewordThis British Standard is the UK implementation of EN 60068-2-20:2008. Itis identical to IEC 60068-2-20:2008. It supersedes BS 2011-2.1T:1981,which will be withdrawn on 1 August 2
3、011.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/501, Electronic assembly technology.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 provisionsof a contr
4、act. Users are responsible for its correct application. BSI 2009ISBN 978 0 580 55763 7ICS 19.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on Amendments issued s
5、ince publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60068-2-20:200831 January 2009EUROPEAN STANDARD EN 60068-2-20 NORME EUROPENNE EUROPISCHE NORM September 2008 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Ko
6、mitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60068-2-20:2008 E ICS 19.040 Supersedes HD 323.2.20 S3:1988English version Environm
7、ental testing - Part 2-20: Tests - Test T: Test methods for solderability and resistance to soldering heat of devices with leads (IEC 60068-2-20:2008) Essais denvironnement - Partie 2-20: Essais - Essai T: Mthodes dessai pour la brasabilit et la rsistance la chaleur de brasage des dispositifs plombs
8、 (CEI 60068-2-20:2008) Umgebungseinflsse - Teil 2-20: Prfungen - Prfung T: Prfverfahren fr die Ltbarkeit und Ltwrmebestndigkeit von Bauelementen mit herausgefhrten Anschlssen (IEC 60068-2-20:2008) This European Standard was approved by CENELEC on 2008-08-01. CENELEC members are bound to comply with
9、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 national standards may be obtained on application to the Central Secretariat
10、 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 and notified to the Central Secretariat has the same status as the off
11、icial versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portuga
12、l, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60068-2-20:2008EN 60068-2-20:2008 2 Foreword The text of document 91/764/FDIS, future edition 5 of IEC 60068-2-20, prepared by IEC TC 91, Electronics assembly technology, was submitted to the IEC-CENELEC paralle
13、l vote and was approved by CENELEC as EN 60068-2-20 on 2008-08-01. This European Standard supersedes HD 323.2.20 S3:1988. The major technical changes with regard to HD 323.2.20 S3:1988 are the following: the solder globule test is deleted; test conditions and requirements for lead-free solders are a
14、dded. 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) 2009-05-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2011-08-01 Anne
15、x ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60068-2-20:2008 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60
16、068-2-54 NOTE Harmonized as EN 60068-2-54:2006 (not modified). IEC 60068-2-58 NOTE Harmonized as EN 60068-2-58:2004 (not modified). IEC 60068-2-69 NOTE Harmonized as EN 60068-2-69:2007 (not modified). IEC 61190-1-3 NOTE Harmonized as EN 61190-1-3:2007 (not modified). _ BS EN 60068-2-20:2008 3 EN 600
17、68-2-20:2008 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references,
18、 the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60068-1 - 1)Environmental testing - Part 1: Gener
19、al and guidance EN 60068-1 1994 2)IEC 60068-2-2 - 1)Environmental testing - Part 2-2: Tests - Test B: Dry heat EN 60068-2-2 2007 2)IEC 60068-2-66 - 1)Environmental testing - Part 2-66: Test methods - Test Cx: Damp heat, steady state (unsaturated pressurized vapour) EN 60068-2-66 1994 2)IEC 60068-2-7
20、8 - 1)Environmental testing - Part 2-78: Tests - Test Cab: Damp heat, steady state EN 60068-2-78 2001 2)IEC 60194 - 1)Printed board design, manufacture and assembly - Terms and definitions EN 60194 2006 2)IEC 61191-3 - 1)Printed board assemblies - Part 3: Sectional specification - Requirements for t
21、hrough-hole mount soldered assemblies EN 61191-3 1998 2)IEC 61191-4 - 1)Printed board assemblies - Part 4: Sectional specification - Requirements for terminal soldered assemblies EN 61191-4 1998 2)1) Undated reference. 2) Valid edition at date of issue. BS EN 60068-2-20:2008 2 60068-2-20 IEC:2008(E)
22、 CONTENTS 1 Scope and object6 2 Normative references .6 3 Terms and definitions .7 4 Test Ta: Solderability of wire and tag terminations8 4.1 Object and general description of the test8 4.1.1 Test methods.8 4.1.2 Specimen preparation8 4.1.3 Initial measurements .9 4.1.4 Accelerated ageing9 4.2 Metho
23、d 1: Solder bath .9 4.2.1 Description of the solder bath 9 4.2.2 Flux .10 4.2.3 Procedure10 4.2.4 Test conditions 10 4.2.5 Final measurements and requirements 11 4.3 Method 2: Soldering iron at 350 C11 4.3.1 Description of soldering irons 11 4.3.2 Solder and flux 12 4.3.3 Procedure12 4.3.4 Final mea
24、surements and requirements 13 4.4 Information to be given in the relevant specification 13 5 Test Tb: Resistance to soldering heat.13 5.1 Object and general description of the test13 5.1.1 Test methods.13 5.1.2 Initial measurements .14 5.2 Method 1: Solder bath .14 5.2.1 Description of the solder ba
25、th 14 5.2.2 Flux .14 5.2.3 Procedure14 5.2.4 Test conditions 14 5.2.5 De-wetting.15 5.3 Method 2: Soldering iron .15 5.3.1 Description of soldering iron 15 5.3.2 Solder and flux 15 5.3.3 Procedure15 5.4 Recovery.16 5.5 Final measurements and requirements 16 5.6 De-wetting (if applicable).16 5.7 Info
26、rmation to be given in the relevant specification 17 Annex A (informative) Example of apparatus for accelerated steam ageing process .18 Annex B (normative) Specification for flux constituents .19 Bibliography20 Figure 1 Diagram of contact angle .7 BS EN 60068-2-20:200860068-2-20 IEC:2008(E) 3 Figur
27、e 2 Position of soldering iron12 Figure A.1 Example of apparatus .18 Table 1 Solderability, Solder bath method: Test severities (duration and temperature).11 Table 2 Resistance to soldering heat, Solder bath method: Test severities (duration and temperature) 15 BS EN 60068-2-20:2008 6 60068-2-20 IEC
28、:2008(E) ENVIRONMENTAL TESTING Part 2-20: Tests Test T: Test methods for solderability and resistance to soldering heat of devices with leads 1 Scope and object This part of IEC 60068 outlines Test T, applicable to devices with leads. Soldering tests for surface mounting devices (SMD) are described
29、in IEC 60068-2-58. This standard provides procedures for determining the solderability and resistance to soldering heat of devices in applications using solder alloys, which are eutectic or near eutectic tin lead (Pb), or lead-free alloys. The procedures in this standard include the solder bath meth
30、od and soldering iron method. The objective of this standard is to ensure that component lead or termination solderability meets the applicable solder joint requirements of IEC 61191-3 and IEC 61191-4. In addition, test methods are provided to ensure that the component body can resist against the he
31、at load to which it is exposed during soldering. NOTE Information about wetting time and wetting force can be obtained by test methods using a wetting balance. See IEC 60068-2-54 (solder bath method) and IEC 60068-2-69 (solder bath and solder globule method for SMDs). 2 Normative references The foll
32、owing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60068-1, Environmental testing Part 1: General and gu
33、idance IEC 60068-2-2, Environmental testing Part 2-2: Tests Tests B: Dry heat IEC 60068-2-66, Environmental testing Part 2-66: Test methods: Test Cx: Damp heat, steady state (unsaturated pressurized vapour) IEC 60068-2-78, Environmental testing Part 2-78: Tests Test Cab: Damp heat, steady State IEC
34、60194, Printed board design, manufacture and assembly Terms and definitions IEC 61191-3, Printed board assemblies Part 3: Sectional specification Requirements for through-hole mount soldered assemblies IEC 61191-4, Printed board assemblies Part 4: Sectional specification Requirements for terminal so
35、ldered assemblies BS EN 60068-2-20:200860068-2-20 IEC:2008(E) 7 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 colophony natural resin obtained as the residue after removal of turpentine from the oleo-resin of the pine tree, consisting mainl
36、y of abietic acid and related resin acids, the remainder being resin acid esters NOTE “Rosin“ is a synonym for colophony, and is deprecated because of the common confusion with the generic term “resin“. 3.2 contact angle in general the angle enclosed between two planes, tangent to a liquid surface a
37、nd a solid/liquid interface at their intersection (see Figure 1). In particular the contact angle of liquid solder in contact with a solid metal surface Contact angle Liquid Solid IEC 1234/08 Figure 1 Diagram of contact angle 3.3 wetting formation of an adherent coating of solder on a surface. A sma
38、ll contact angle is indicative of wetting 3.4 non-wetting inability to form an adherent coating of solder on a surface. In this case the contact angle is greater than 90 3.5 de-wetting retraction of molten solder on a solid area that it has initially wetted NOTE In some cases an extremely thin film
39、of solder may remain. As the solder retracts the contact angle increases. 3.6 solderability ability of the termination or lead of device to be wetted by solder at the temperature of the termination or lead which is assumed to be the lowest temperature in the soldering process within solderable tempe
40、rature of solder alloy BS EN 60068-2-20:2008 8 60068-2-20 IEC:2008(E) 3.7 soldering time time required for a defined surface area to be wetted under specific conditions 3.8 resistance to soldering heat ability of device to withstand the highest temperature of the termination or lead in soldering pro
41、cess, within applicable temperature range of solder alloy 3.9 lead-free solder alloy that does not contain more than 0,1 % lead (Pb) by weight as its constituent and is used for joining components to substrates or for coating surfaces 75.1904 of IEC 60194 4 Test Ta: Solderability of wire and tag ter
42、minations 4.1 Object and general description of the test 4.1.1 Test methods Test Ta provides two different test methods to determine the solderability of the areas on wire and tag terminations that are required to be wetted by solder. Method 1: Solder bath Method 2: Soldering iron The test method to
43、 be used shall be indicated in the relevant specification. The solder bath method is the one which simulates most closely the soldering procedures of flow soldering and similar soldering processes. The soldering iron method may be used in cases where Method 1 is impracticable. If required by the rel
44、evant specification, the test conditioning may be preceded by accelerated ageing. The following are recommended conditions: Ageing 1a: 1 h steam ageing Ageing 1b: 4 h steam ageing Ageing 2: 10 days damp heat, steady state condition (40 2) C; (93 3) % RH (Test Cab) Ageing 3a: 4 h at 155 C dry heat (T
45、est Bb) Ageing 3b: 16 h at 155 C dry heat (Test Bb). Ageing 4: 4 h unsaturated pressurized vapour (Test Cx) NOTE The test specimens may be introduced into the chamber at any temperature from laboratory temperature to the specified temperature. 4.1.2 Specimen preparation The surface to be tested shal
46、l be in the “as received“ condition and shall not be subsequently touched by the fingers or otherwise contaminated. The specimen shall not be cleaned prior to the application of a solderability test. If required by the relevant specification, the specimen may be degreased by immersion in a neutral o
47、rganic solvent at room temperature. BS EN 60068-2-20:200860068-2-20 IEC:2008(E) 9 4.1.3 Initial measurements The specimens shall be visually examined and, if required by the relevant specification, electrically and mechanically checked. 4.1.4 Accelerated ageing If accelerated ageing is required by t
48、he relevant specification, one of the following procedures shall be adopted. At the end of the conditioning, the specimen shall be subjected to standard atmospheric conditions for testing for not less than 2 h and not more than 24 h. NOTE Terminations may be detached if the ageing temperature is hig
49、her than the components maximum operating or storage temperature, or if the component is likely to degrade considerably at 100 C in steam and thus affect the solderability in a manner which would not normally occur in natural ageing. 4.1.4.1 Ageing 1 The relevant specification shall indicate whether ageing 1a (1 h in steam) or ageing 1b (4 h in steam) is to be used. For these procedures the specimen is suspended, prefe
