A Study on Relationship between Orientation Evolution and Coarsening Behavior of Cu6Sn5 Grains Formed on Polycrystalline Cu Substrate

Abstract

The coarsening behavior of Cu6Sn5 grains formed at the Sn37Pb/Polycrystalline Cu interface is investigated in terms of their orientation evolution during solid-state aging. The results show that the coarsening behavior of the interfacial Cu6Sn5 grains during solid-state aging are quite different from that during liquid-state soldering. The occurrence of the coarsening in the solid-sate reaction is caused by the different surface energies between two adjacent grains. In addition, the texture morphologies of the interfacial grains affect their coarsening rates. In particular, the interfacial Cu6Sn5 grains formed at 200 oC exhibit a texture with the [0001] direction normal to the interface after 16 days of aging at 150 oC, and the formation of this texture accelerates the coarsening process of the interfacial Cu6Sn5 grains.