Experiments on Microstructure, Joint Strength of Sn3Ag0.5Cu, Sn8Zn3Bi versus 63Sn37Pb in High Density Assembly Application

The European community has been finalized to phase out on July 1, 2006 for lead (Pb) in electronic products. This cause the EMS is required to study new materials for replacing the lead in its products. This paper presents the manufacturability and reliability study of two competitive lead-free alternatives. A series experiments are carried out, and the voids, microstructure and joint strength of Sn₃Ag_0.5Cu, Sn₈Zn₃Bi versus traditional ⁶³Sn³⁷Pb are compared and analyzed, which conclude Sn₃Ag_0.5Cu and ⁶³Sn³⁷Pb can be reliable application from leaded soldering process transition to lead-free process and the more voids tendency in Sn₈Zn₃Bi must be under control