Characterisation Of Electroplated Eutectic Sn-Ag Solder

Abstract

This paper discusses the effects of electro-deposition processing conditions on the film composition and surface morphology. The rate of Ag deposition onto the bump depends on various processing parameters like current density, agitation and temperature. Among these parameters, the Ag content in the bump was found to be most sesitive to current plating density. At various Ag content, the morphology of the deposited solder was found to be different. This is due to the different types of drain growth at different Ag content. A high content bump was found with a needle-like Ag3Sn structure. This strcuture is believed to be the cause for the reduction in shear strength.