T0301-1-5 Effect of Doped Ag on Pressure-induced Tin Whisker Formation

Abstract

This paper presents the effect of doped Ag on pressure-induced tin whisker formation. Nanoindentation tests were carried out for pure tin and Ag doped tin finishes. Pressure induced tin defects were found near the contact area. Tin whisker formation was mitigated on the surface of Ag doped tin finish. Smaller grain size of Ag doped tin finish make a threshold stress to produce tin whisker high. Creep property was also changed because of doping of Ag. Since stress relaxation occur quickly, lower stresses are generated in the Ag doped tin finish. These two effect can mitigate tin whisker formation. EPMA also revealed that Ag concentrates to the indented area. It suggests that the migration of Ag influences the mitigation of pressure induced tin whiskers.