Effect of additive elements on crack propagation behavior for Sn-Bi solders at high temperatures

This paper discusses the effect of additive elements on crack propagation behavior for Sn-Bi solders at high temperatures. Sn-Bi solders are lower melting point materials, so that it is useful for low temperature soldering. Crack initiation and propagation behavior of three kinds of Sn-Bi solders were observed in this study. There were effects of additive elements Ag, Cu, Ni and Ge on crack propagation rate although there was no effect on crack initiation. The crack propagation of Sn57.5Bi0.5AgCuNiGe solder seems to have a slower rate than Sn58Bi and Sn57.5Bi0.5Ag solders. The J-integral range parameter evaluates the crack propagation rate independent of the additive elements at high temperatures.