1、 IEC 61191-6Edition 1.0 2010-01INTERNATIONAL STANDARD NORME INTERNATIONALEPrinted board assemblies Part 6: Evaluation criteria for voids in soldered joints of BGA and LGA and measurement method Ensembles de cartes imprimes Partie 6: Critres dvaluation des vides dans les joints brass des botiers BGA
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16、vous avez des questions, visitez le FAQ du Service clients ou contactez-nous: Email: csciec.ch Tl.: +41 22 919 02 11 Fax: +41 22 919 03 00 IEC 61191-6Edition 1.0 2010-01INTERNATIONAL STANDARD NORME INTERNATIONALEPrinted board assemblies Part 6: Evaluation criteria for voids in soldered joints of BGA
17、 and LGA and measurement method Ensembles de cartes imprimes Partie 6: Critres dvaluation des vides dans les joints brass des botiers BGA et LGA et mthode de mesure INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE WICS 31.180 PRICE CODECODE PRIXISBN 2-8318-1076-3
18、Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale colourinside 2 61191-6 IEC:2010 CONTENTS FOREWORD.4 INTRODUCTION.6 1 Scope.7 2 Normative references .7 3 Terms and definitions .7 4 Voids in solder joints 8 4.1 General
19、 .8 4.2 Sources of voids8 4.3 Impact of voids9 4.4 Void detection .9 4.5 Void classification .9 5 Measurement .10 5.1 X-ray transmission equipment .10 5.2 Measuring environment .10 5.3 Measurement procedure10 5.4 Record of the measured value.11 5.5 Considerations on measurement .11 5.5.1 X-ray inten
20、sity for void detection11 5.5.2 Detection of real edge .11 5.5.3 Verification of measurement results.11 6 Void occupancy 11 6.1 Calculation of void occupancy .11 6.2 Void occupancy for multiple voids14 7 Evaluation 14 7.1 Soldered joints to be evaluated .14 7.2 Evaluation of thermal life cycle decre
21、ased due to voids .14 7.3 Evaluation criteria for voids .15 Annex A (informative) Experimental results and simulation of voids and decrease of life due to thermal stress.16 Annex B (informative) X-ray transmission equipment .20 Annex C (informative) Voids in BGA solder ball .22 Annex D (informative)
22、 Measurement using X-ray transmission imaging34 Bibliography38 Figure 1 Void occupancy13 Figure 2 Voids in a soldered joint.15 Figure A.1 BGA soldered joint, Sn-Ag-Cu.17 Figure A.2 BGA soldered joint, Sn-Zn 17 Figure A.3 LGA soldered joint 18 Figure B.1 Construction of the equipment 20 Figure C.1 Sm
23、all voids clustered in mass at the ball-to-land interface 26 Figure C.2 X-ray image of solder balls with voids.27 Figure C.3 Example of voided area at land and board interface .27 Figure C.4 Voids in BGAs with crack started at corner lead31 61191-6 IEC:2010 3 Figure D.1 X-ray transmission imaging.35
24、 Figure D.2 X-ray transmission imaging of solder joint.36 Figure D.3 Typical X-ray transmission images of solder joint36 Table 1 Void classification .9 Table 2 Examples of Cross-section of joint and void occupancy.14 Table A.1 Fatigue life reduced by voids in soldered joint of BGA17 Table A.2 Fatigu
25、e life reduced by voids in soldered joint of LGA 18 Table A.3 Voids evaluation criteria for soldered joints of BGA19 Table A.4 Voids evaluation criteria for soldered joints of LGA 19 Table C.1 Void classification27 Table C.2 Corrective action indicator for lands used with 1,5 mm, 1,27 mm or 1,0 mm p
26、itch.28 Table C.3 Corrective action indicator for lands used with 0,8 mm, 0,65 mm or 0,5 mm pitch .30 Table C.4 Corrective action indicator for micro-via in-pad lands used with 0,5 mm, 0,4 mm or 0,3 mm pitch 32 Table C.5 Ball-to-void size image comparison for common ball contact diameters .33 Table
27、C.6 C = 0 sampling plan (sample size for specific index value).33 4 61191-6 IEC:2010 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ PRINTED BOARD ASSEMBLIES Part 6: Evaluation criteria for voids in soldered joints of BGA and LGA and measurement method FOREWORD 1) The International Electrotechnical Comm
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37、on or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publicati
38、on may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 61191-6 has been prepared by IEC technical committee 91: Electronics assembly technology. The text of this standard is based on the following documents:
39、 FDIS Report on voting 91/897/FDIS 91/909/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts of the IEC 61191
40、series, under the general title Printed board assemblies, can be found on the IEC website. 61191-6 IEC:2010 5 The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the dat
41、a 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 correct
42、understanding of its contents. Users should therefore print this document using a colour printer. 6 61191-6 IEC:2010 INTRODUCTION The necessity for the evaluation of voids in soldered joints increases in the industry because the voids may affect the reliability of joints as the devices get smaller.
43、As the number of interconnections increases the reliability per joint must also increase. This subject has been discussed in some countries and trade organizations, and specific proposals have been made for classification or evaluation of voids to develop process guidelines. The same subject is also
44、 studied in academia to find correlation between voids and reliability of a joint. Appreciable findings are now available from the reliability study including relation between shapes of voids and degradation of life due to voids in a joint in thermal cycle stress. Based on the information available,
45、 we developed evaluation criteria of voids in soldered joints for BGA (Ball Grid Array) and LGA (Land Grid Array) and a measurement method. 61191-6 IEC:2010 7 PRINTED BOARD ASSEMBLIES Part 6: Evaluation criteria for voids in soldered joints of BGA and LGA and measurement method 1 Scope This part of
46、IEC 61191 specifies the evaluation criteria for voids on the scale of the thermal cycle life, and the measurement method of voids using X-ray observation. This part of IEC 61191 is applicable to the voids generated in the solder joints of BGA and LGA soldered on a board. This part of IEC 61191 is no
47、t applicable to the BGA package itself before it is assembled on a board. This standard is applicable also to devices having joints made by melt and re-solidification, such as flip chip devices and multi-chip modules, in addition to BGA and LGA. This standard is not applicable to joints with under-f
48、ill between a device and a board, or to solder joints within a device package. This standard is applicable to macrovoids of the sizes of from 10 m to several hundred micrometres generated in a soldered joint, but is not applicable to smaller voids (typically, planar microvoids) with a size of smalle
49、r than 10 m in diameter. This standard is intended for evaluation purposes and is applicable to research studies, off-line production process control and reliability assessment of assembly 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. Fo
