Growth mechanism of Cu-Sn full IMC joints on polycrystalline and single crystal Cu substrate

Rui Zhang,Baolei Liu,Chunjin Hang,Yanhong Tian

doi:10.1109/icept.2013.6756690

Abstract

Growth mechanisms of Cu-Sn IMC joints bonded at 300°C on polycrystalline and single crystal Cu substrates were investigated by Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction (EBSD) technology. The results showed that the prism-type Cu 6 Sn 5 grains formed on single crystal Cu substrate in the initial stage grew into the scallop-type Cu 6 Sn 5 grains by grain rotation and merge mechanism with the proceeding of the bonding. In addition, the scallop-type Cu 6 Sn 5 grains didn't have preferred orientation. The columnar Cu 3 Sn grains grew in clusters at the expense of Cu 6 Sn 5 along direction of the adjacent Cu 6 Sn 5 grains grain boundaries. The orientation of Cu 3 Sn was unrelated to that of Cu or Cu 6 Sn 5 , but had preferred orientations of Cu 3 Sn (100) parallel to the Cu substrate.

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