Sn which becomes the Pb free solder joint structure

摘要

PROBLEM TO BE SOLVED: To provide a Pb-free solder connection structure that has proper connection strength, a stable interface with time, and can secure whisker- resistance properties or the like, and to provide electronic equipment.;SOLUTION: Sn-Ag-Bi-based solder that is a likely candidate as Pb solder is connected to an electrode, whose surface has an Sn-Bi-based layer. Bi concentration in the Sn-Bi layer should preferably be 1-2 wt.% for improved wetting properties. Furthermore, when highly reliable joint is required, by providing a Cu layer under the Sn-Bi layer, a connection section having sufficient interface strength is obtained.;COPYRIGHT: (C)2002,JPO