Development of Bi-Based Pb-Free Solders for High-Temperature

Abstract

Bi-based alloys were investigated for their potential to replace Pb-based solders for high-temperature applications. It is found that Bi–Ag, Bi–Sn and Bi–Zn alloys improve the mechanical properties of the solder, especially Bi–Zn alloy, which shows good workability for wire extrusion. In addition, Bi–Zn alloy has good wettability on Ag-plated substrates and prevents the surplus Bi–Ni reaction in the soldering process. As a result, Bi–Zn alloys with a solidus temperature of 255C are proposed as Pb-free solders for high-temperature applications.