Cobalt is a candidate for under bump metallization of potential integration in electronics interconnection and packaging. Owing to reactive diffusion at interconnection between Co and a Sn-based solder, Co-Sn compounds are formed during soldering, and then gradually grow during energization heating at solid-state temperatures. However, the Co-Sn compounds are brittle and possess high electrical resistivities. Thus, the growth of the compounds deteriorates the electrical and mechanical properties of the interconnection. For application of Co in the electronics industry, reliable information on the growth behavior of the Co-Sn compounds is essentially important. Nevertheless, no such reliable information is available in literatures. In the present study, the reactive diffusion between Co and Sn was experimentally observed at solid-state temperatures of 453-493 K in a metallographical manner. The rate-controlling process of the reactive diffusion was discussed on the basis of the observation.
各種検索
サポート
ヘルプ