The Effects of Ag, Ni, and Ge elements in Lead-free Sn Base Solder Alloy

Sn-Ag-Cu alloys are widely used as lead-free solders. Demand has recently emerged for solder of lower Ag content particularly for flow soldering processes. This paper describes a study of the effects of adding varying amounts of Ag, Ni, and Ge content on the wettability and dissolution of Cu wire. The results indicate wetting times depend primarily on temperature difference from the liquidus line associated with varying Ag content. Solder to which Ni and Ge have been added shows improved spreading characteristics, and Ni content proved to the primary factor with respect to rupture times in Cu erosion tests. A (Cu, Ni)-Sn compound layer was observed to form at the remnant Cu wire surface. "P0563. doc".