Abstract
This paper treats experimental observation on mechanical behavior such as viscoplastic deformation of both Pb and Pb free solder alloys. The tests conducted in this work are pure tension, cyclic tension-compression loading, creep and stress relaxation. The test results show that the Pb solder alloy has larger time dependent deformation comparing with Pb free solder alloys. The stress relaxation of the Pb solder alloys is, especially, larger than that of the Pb free solder alloy. The smaller stress relaxation of the Pb free solder alloy leads to bending of the substrate. The method to simulate the deformation of Pb free solder alloys is also discussed.
