Reliability studies of surface mount, solder joints-effect of Cu-Sn intermetallic compounds
- 19 November 2002
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 1073-1080
- https://doi.org/10.1109/ectc.1995.517824
Abstract
Cu-Sn intermetallic compounds (IMC), formed at the interface between the solder and the copper substrate are found to play an important role in determining the thermal fatigue life of a surface mount solder joint. In order to predict the growth of this IMC layer during the operating life of the solder joint and its effect on the thermal fatigue life, the formation characteristics of Cu-Sn IMCs in 0805 and 1206 LCCC solder joints fabricated from an IR-reflow process are investigated in this work. Only the stable Cu/sub 6/Sn/sub 5/ /spl eta/-phase intermetallic compound was observed in all as-solidified solder joints. The mean layer thickness was found to increase almost linearly with reflow time. The thickness of the interfacial IMC layer increased with increasing reflow temperature in 0805-type solder joints up to around 250/spl deg/C and reached an equilibrium thickness above this temperature. Further intermetallic formation due to higher reflow temperature or longer reflow time appeared as Cu-Sn whiskers in the bulk solder of the solder joints. The copper land pad size and qualify of component lead metallization were also found to greatly affect the formation of Cu-Sn IMC in surface mount solder joints.Keywords
This publication has 10 references indexed in Scilit:
- Applications of X-Ray Radiography to the Study of Porosities in Surface Mount Solder JointsPublished by Springer Nature ,1994
- Handbook of Fine Pitch Surface Mount TechnologyPublished by Springer Nature ,1994
- The growth of Cu-Sn intermetallics at a pretinned copper-solder interfaceMetallurgical Transactions A, 1992
- Analysis of low-temperature intermetallic growth in copper-tin diffusion couplesMetallurgical Transactions A, 1992
- Solder Paste in Electronics PackagingPublished by Springer Nature ,1989
- Tensile behavior of pb-sn solder/cu jointsJournal of Electronic Materials, 1987
- The effect of Cu6Sn5 whisker precipitates in bulk 60sn-40pb solderJournal of Electronic Materials, 1987
- The formation of Cu3Sn intermetallic on the reaction of cu with 95Pb-5Sn solderJournal of Electronic Materials, 1986
- Kinetics of interfacial reaction in bimetallic CuSn thin filmsActa Metallurgica, 1982
- Interdiffusion and reaction in bimetallic Cu-Sn thin filmsActa Metallurgica, 1973