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Indexed by:会议论文

Date of Publication:2010-01-01

Included Journals:EI、CPCI-S、Scopus

Page Number:1097-1101

Abstract:The eta-eta' transformation of interfacial Cu6Sn5 in solder joints was studied. Two cooling rates were selected to obtain different grain sizes of intermetallic compounds (IMCs). In the case of air cooling, the compounds were tiny and no eta-eta' transformation was detected in the as-soldered state. Under furnace cooling, however, thick and coarse interfacial IMCs were obtained and eta was still stable. After aging 2d at 150 degrees C, eta-eta' transformation was detected no matter what cooling rate. This indicates that effects of IMC thickness and grain size are negligible in some way. It is also shown that aging at 150 degrees C. promoted the interfacial eta-eta' transformation and the time needed was comparatively short to that of long-term aging study of solid/solid growth kinetics. These provide us a significant reference to understand the obtained reliability data and evaluate the possible threats of transformation to the interconnects. For Ni-bearing solder joints, interfacial (Cu, Ni)(6)Sn-5 was detected. Only eta-phase was discovered after soldering and aging.