Planar Geometry Solder Joint Study of Alloying Effects on Sn-Bi Electromigration

Planar geometry solder joints have proven to be a convenient way of studying electromigration and microstructural evolution in low-temperature solder joints, such as those of Sn-Bi alloys, subjected to relatively high electric current densities and temperatures. The metallurgical and electro migration behaviors of planar solder joints are like those of bottom-terminated-component (BTC) solder joins and can be readily observed in-situ in a scanning electron microscope. In this paper, the planar geometry solder joint approach was used to study the effect of small additions of Sb, Ni, Cu and Ag on the electro migration behavior of eutectic and hypo eutectic Sn-Bi alloys.