The Effect on the Mechanical Properties of P Addition and Bi Content to Sn-Ag-In-Bi Solders and on Their Joint Strength with Cu

Abstract

In order to improve joint reliability of Sn-Ag-In-Bi solder with Bi more than 5%, the effect of Bi addition content and P addition to Sn-Ag-In-Bi lead-free solder on mechanical properties and joint strength has been investigated. The tensile strength increases with Bi addition up to 10%, on the other hand the elongation decreases with Bi addition up to 6%. At Bi addition more than 10% and 6%, the tensile and elongation are constant. There is no P addition effect to mechanical properties of Sn-Ag-In-Bi. The joint strength of Sn-3.5Ag-3In-6Bi decreases by about 20% after annealing at 100°C for 1000h, but the joint strength does not decrease with annealing time by 90-340ppm P addition to Sn-3.5Ag-3In-6Bi. The P addition to Sn-Ag-In-Bi has effect that the growth of reaction layers is inhibited.