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Indexed by:会议论文

Date of Publication:2014-08-12

Included Journals:EI、CPCI-S、SCIE、Scopus

Page Number:937-939

Key Words:intermetallic compounds (IMC); morphology; growth behavior; Cu6Sn5; solidification; multiple reflows

Abstract:The appearance of IMCs on the Sn/Cu interface plays an important role in the joint reliability. Their growth behavior during solidification of multiple reflows was investigated. Compressed air was employed to blow away the residual liquid solder immediately after heating preservation so that the morphology corresponding to heating preservation would remain unaltered; and then by compared they with samples experienced air cooling, the growth of interfacial Cu6Sn5 grains could be investigated separately. The morphology of Cu6Sn5 grains remained a scallop-type during heating preservations of multiple reflows and they always converted to prism-type after air cooling. The dissolution and precipitation of Cu in liquid Sn with the temperature fluctuations should be responsible to the transformation. Moreover, scalloped Cu6Sn5 grains appeared at heating preservation became larger with the increasing number of reflows due to the ripening reaction. Their growth in dimension induced a change in appearance of those prismatic Cu6Sn5 grains formed on them. Shorter but larger main facets formed on those prismatic Cu6Sn5 grains with the increasing number of reflows.