1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationSemiconductor devices Mechanical and climatic testmethods Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture andsoldering heatBS EN 60749-20:2009
2、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:54, Uncontrolled Copy, (c) BSINational forewordThis British Standard is the UK implementation of EN 60749-20:2009. It isidentical to IEC 60749-20:2008. It supersedes BS EN 60749-20:2003 which iswithdrawn.The UK participation in its
3、 preparation was entrusted to Technical CommitteeEPL/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 of acontract. Users are responsible for its correct appli
4、cation. BSI 2010ISBN 978 0 580 59478 6ICS 31.080.01Compliance 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 January 2010Amendments issued since publicationAmd. No. Date
5、Text affectedBRITISH STANDARDBS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:54, Uncontrolled Copy, (c) BSIEUROPEAN STANDARD EN 60749-20 NORME EUROPENNE EUROPISCHE NORM November 2009 CENELEC European Committee for Electrotechnical Standardization Comit Europen
6、 de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: Avenue Marnix 17, B - 1000 Brussels 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60749-20:2009 E ICS 31.080.01 Supers
7、edes EN 60749-20:2003English version Semiconductor devices - Mechanical and climatic test methods - Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat (IEC 60749-20:2008) Dispositifs semiconducteurs - Mthodes dessais mcaniques et climatiques - Part
8、ie 20: Rsistance des CMS botiers plastique leffet combin de lhumidit et de la chaleur de brasage (CEI 60749-20:2008) Halbleiterbauelemente - Mechanische und klimatische Prfverfahren - Teil 20: Bestndigkeit kunststoffverkappter oberflchenmontierbarer Bauelemente (SMD) gegenber der kombinierten Beansp
9、ruchung von Feuchte und Ltwrme (IEC 60749-20:2008) This European Standard was approved by CENELEC on 2009-09-01. 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 an
10、y alteration. Up-to-date lists and bibliographical references concerning such national 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 mad
11、e 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 official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, E
12、stonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA
13、STANDARDS, 13/04/2010 02:54, Uncontrolled Copy, (c) BSIEN 60749-20:2009 2 Foreword The text of document 47/1989/FDIS, future edition 2 of IEC 60749-20, prepared by IEC TC 47, Semiconductor devices, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60749-20 on 2009-09-0
14、1. This European Standard supersedes EN 60749-20:2003. The main changes are as follows: to reconcile certain classifications of EN 60749-20 and those of IPC/JEDEC J-STD-020C; reference EN 60749-35 instead of Annex A of EN 60749-20:2003; update for lead-free solder; correct certain errors in EN 60749
15、-20:2003. 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) 2010-06-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2012-09-01
16、Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60749-20:2008 was approved by CENELEC as a European Standard without any modification. _ BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:54, Uncontrolled Copy,
17、(c) BSI 3 EN 60749-20:2009 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 undat
18、ed references, 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 60068-2-20 2008 Environmental testi
19、ng - Part 2-20: Tests - Test T: Test methods for solderability and resistance to soldering heat of devices with leads EN 60068-2-20 2008 IEC 60749-3 - 1)Semiconductor devices - Mechanical and climatic test methods - Part 3: External visual examination EN 60749-3 2002 2)IEC 60749-35 - 1)Semiconductor
20、 devices - Mechanical and climatic test methods - Part 35: Acoustic microscopy for plastic encapsulated electronic components EN 60749-35 2006 2)1)Undated reference. 2)Valid edition at date of issue. BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:54, Uncontro
21、lled Copy, (c) BSI 2 60749-20 IEC:2008 CONTENTS 1 Scope.6 2 Normative references6 3 General description.6 4 Test apparatus and materials6 4.1 Humidity chamber6 4.2 Reflow soldering apparatus6 4.3 Holder .7 4.4 Wave-soldering apparatus .7 4.5 Solvent for vapour-phase reflow soldering7 4.6 Flux.7 4.7
22、Solder .7 5 Procedure.7 5.1 Initial measurements .7 5.1.1 Visual inspection7 5.1.2 Electrical measurement8 5.1.3 Internal inspection by acoustic tomography 8 5.2 Drying8 5.3 Moisture soak8 5.3.1 General .8 5.3.2 Conditions for non-dry-packed SMDs .8 5.3.3 Moisture soak for dry-packed SMDs.8 5.4 Sold
23、ering heat .10 5.4.1 General .10 5.4.2 Method of heating by infrared convection or convection reflow soldering11 5.4.3 Method of heating by vapour-phase reflow soldering.12 5.4.4 Method of heating by wave-soldering12 5.5 Recovery.13 5.6 Final measurements 14 5.6.1 Visual inspection14 5.6.2 Electrica
24、l measurement14 5.6.3 Internal inspection by acoustic tomography 14 6 Information to be given in the relevant specification.14 Annex A (informative) Details and descriptions of test method on resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat16 Figure 1 Met
25、hod of measuring the temperature profile of a specimen7 Figure 2 Heating by wave-soldering 13 Figure A.1 Process of moisture diffusion at 85 C, 85 % RH17 Figure A.2 Definition of resin thickness and the first interface .17 Figure A.3 Moisture soak time to saturation at 85 C as a function of resin th
26、ickness 18 Figure A.4 Temperature dependence of saturated moisture content of resin18 Figure A.5 Dependence of moisture content of resin at the first interface on resin thickness under various soak conditions19 BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:5
27、4, Uncontrolled Copy, (c) BSI60749-20 IEC:2008 3 Figure A.6 Dependence of moisture content of resin at the first interface on resin thickness related to method A of moisture soak.20 Figure A.7 Dependence of the moisture content of resin at the first interface on resin thickness related to method B o
28、f moisture soak.21 Figure A.8 Dependence of moisture content of resin at the first interface on resin thickness related to condition B2 of method B of moisture soak .21 Figure A.9 Temperature profile of infrared convection and convection reflow soldering for Sn-Pb eutectic assembly23 Figure A.10 Tem
29、perature profile of infrared convection and convection reflow soldering for lead-free assembly23 Figure A.11 Classification profile 25 Figure A.12 Temperature profile of vapour-phase soldering (condition II-A).25 Figure A.13 Immersion method into solder bath 26 Figure A.14 Relation between the infra
30、red convection reflow soldering and wave-soldering.26 Figure A.15 Temperature in the body of the SMD during wave-soldering .27 Table 1 Moisture soak conditions for non-dry-packed SMDs .8 Table 2 Moisture soak conditions for dry-packed SMDs (method A) 9 Table 3 Moisture soak conditions for dry-packed
31、 SMDs (method B) 10 Table 4 SnPb eutectic process Classification reflow temperatures .11 Table 5 Pb-free process Classification reflow temperatures .12 Table 6 Heating condition for vapour-phase soldering.12 Table 7 Immersion conditions for wave-soldering13 Table A.1 Comparison of actual storage con
32、ditions and equivalent moisture soak conditions before soldering heat18 Table A.2 Classification profiles24 BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:54, Uncontrolled Copy, (c) BSI 6 60749-20 IEC:2008 SEMICONDUCTOR DEVICES MECHANICAL AND CLIMATIC TEST ME
33、THODS Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat 1 Scope This part of IEC 60749 provides a means of assessing the resistance to soldering heat of semiconductors packaged as plastic encapsulated surface mount devices (SMDs). This test is des
34、tructive. 2 Normative references The following 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 60068-2-20:2
35、008, Environmental testing Part 2-20: Tests Test T: Test methods for solderability and resistance to soldering heat of devices with leads IEC 60749-3, Semiconductor devices Mechanical and climatic test methods Part 3: External visual inspection IEC 60749-35, Semiconductor devices Mechanical and clim
36、atic test methods Part 35: Acoustic microscopy for plastic encapsulated electronic components 3 General description Package cracking and electrical failure in plastic encapsulated SMDs can result when soldering heat raises the vapour pressure of moisture which has been absorbed into SMDs during stor
37、age. These problems are assessed. In this test method, SMDs are evaluated for heat resistance after being soaked in an environment which simulates moisture being absorbed while under storage in a warehouse or dry pack. 4 Test apparatus and materials 4.1 Humidity chamber The humidity chamber shall pr
38、ovide an environment complying with the temperature and relative humidity defined in 5.3. 4.2 Reflow soldering apparatus The infrared convection, the convection and the vapour-phase reflow soldering apparatus shall provide temperature profiles complying with the conditions of soldering heat defined
39、in 5.4.2 and 5.4.3. The settings of the reflow soldering apparatus shall be adjusted by temperature profiling of the top surface of the specimen while it is undergoing the soldering heat process, measured as shown in Figure 1. BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS,
40、 13/04/2010 02:54, Uncontrolled Copy, (c) BSI60749-20 IEC:2008 7 ThermocoupleHolderResinLead pinsDieAdhesive agent or thin tapeIEC 1746/01NOTE The adhesive agent or thin tape should have good thermal conductivity. Figure 1 Method of measuring the temperature profile of a specimen 4.3 Holder Unless o
41、therwise detailed in the relevant specification, any board material, such as epoxy fibreglass or polyimide, may be used for the holder. The specimen shall be placed on the holder by the usual means and in a position as shown in Figure 1. If the position of the specimen, as shown in Figure 1, necessi
42、tates changing the shape of terminations and results in subsequent electrical measurement anomalies, a position that avoids changing the shape of terminations may be chosen, and this shall be specified in the relevant specification. 4.4 Wave-soldering apparatus The wave-soldering apparatus shall com
43、ply with conditions given in 5.4.4. Molten solder shall usually be flowed. 4.5 Solvent for vapour-phase reflow soldering Perfluorocarbon (perfluoroisobutylene) shall be used. 4.6 Flux Unless otherwise detailed in the relevant specification, the flux shall consist of 25 % by weight of colophony in 75
44、 % by weight of isopropyl alcohol, both as specified in Annex B of IEC 60068-2-20:2008. 4.7 Solder Solder of composition as specified in Table 1 of IEC 60068-2-20:2008 shall be used. 5 Procedure 5.1 Initial measurements 5.1.1 Visual inspection Visual inspection, as specified in IEC 60749-3, shall be
45、 performed before the test. Special attention shall be paid to external cracks and swelling, which will be looked for under a magnification of 40. BS EN 60749-20:2009Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/04/2010 02:54, Uncontrolled Copy, (c) BSI 8 60749-20 IEC:2008 5.1.2 Electric
46、al measurement Electrical testing shall be performed as required by the relevant specification. 5.1.3 Internal inspection by acoustic tomography Unless otherwise detailed in the relevant specification, internal cracks and delamination in the specimen shall be inspected by acoustic tomography in acco
47、rdance with IEC 60749-35. 5.2 Drying Unless otherwise detailed in the relevant specification, the specimen shall be baked at 125 C 5 C for at least 24 h. 5.3 Moisture soak 5.3.1 General Unless otherwise detailed in the relevant specification, moisture soak conditions shall be selected on the basis o
48、f the packing method of the specimen (see A.1.1). If baking the specimen before soldering is detailed in the relevant specification, the specimen shall be baked instead of being subject to moisture soak. 5.3.2 Conditions for non-dry-packed SMDs The moisture soak condition shall be selected from Tabl
49、e 1, in accordance with the permissible limit of actual storage (see A.1.2.1). Table 1 Moisture soak conditions for non-dry-packed SMDs Condition Temperature C Relative humidity % Duration time h Permissible limit on actual storage A1 or B1 85 2 85 5 168 24 2 000 C 10 Method A 20 2,5 Method B 30 250 245 245 5.4.3 Method of heating by vapour-phase reflow soldering 5.4.3.1 Preparation The sp
