Strain-rate-dependant mechanical properties for Sn-3.8Ag-0.7Cu and SAC-X solder alloy

The mechanical properties of electronic solder materials are highly dependent on test temperature and strain rate. In this paper strain rate dependent elastic modulus and yield strength of Sn-3.8Ag-0.7Cu and Sn-Ag-Cu-X (SAC-X) where, X is a small addition of a fourth element. Nano-indentation tests were conducted from slow to intermediate strain rates, (10^-3 ~10¹) by using the continuous stiffness measurement (CSM) technique. The strain-rate-dependent yield stress is curve fitted to a power law relationship with strain rate. For all the tests conducted, the higher the strain rate the higher the elastic modulus and yield stress of the solder; the higher the temperature the lower the elastic modulus and yield stress.