Epitaxial growth of intermetallic compounds formed at eutectic Sn37Pb/polycrystalline Cu interface during solid-state aging

摘要

Epitaxial growth of intermetallic compounds formed at eutectic Sn37Pb/ polycrystalline Cu interface during solid-state aging. The results show that the interfacial Cu6Sn5 grains exhibit textured growth under solid-state condition and their preferred orientations are affected by the as-soldered joints. Cu6Sn5 grains with [0001] direction normal to the interface are stable in solid and molten Sn37Pb solder at 200 ºC, but will be rapidly consumed at 280 ºC, which leads to the formation of different textures in Cu6Sn5 layer during the solid-state aging treatment to the joints formed at 200 ºC and 280 ºC. Also, the effects of the texture evolution on the growth of interfacial IMCs are evaluated. The results show that Cu diffusion along [0001] direction of Cu6Sn5 is faster and therefore more interfacial IMCs are generated in the joints formed at 200 ºC than those formed at 280 ºC under the same solid-state reaction conditions.