A Study of Microstructure and Mechanical Properties of Eutectic In-Sn Solder Added Ag

Abstract

  In this study, effect of Ag addition on microstructure of In-48 wt%Sn solder was investigated to improve mechanical properties. The microstructure of In-Sn-Ag solder was formed by β phase, γ phase and two different intermetallic compounds (IMCs) which are Ag₂In and AgIn₂. Ag₂In in In-Sn-Ag solder improves the mechanical strength but deteriorates the ductility. However, AgIn₂ enhances the ductility but decreases the mechanical strength. To improve the both mechanical strength and ductility, control of the amount of Ag₂In and AgIn₂ was found to be important, and 3 wt% Ag addition was found to improve both mechanical strength and ductility of In-48 wt%Sn solder.