Shock Wave Effect on Micromechanics Properties of Sn-Ag-Cu solder (SAC 387) via Nanoindentation

Abstract

A variety of Sn-Ag-Cu solder alloys have been proposed and recommended for use in industrial organizations for example Sn-95.5Ag3.8Cu-0.7 (SAC 387) by the European Consortium Brite-Euram in the European Union. In this study an effect of shock wave on micromechanics properties of SAC 387 solder was investigated via nanoindentation approach. Solder joint of SAC 387 on copper substrate was prepared by hand soldering techniques. Then soldered samples were exposed to shock wave at different distance of 1 m, 2 m and 3 m. The shock wave test was conducted using 500 g of trinitrotoluene (TNT). Hardness value of SAC 387 decreased from 300 MPa to 130 MPa as well as reduced modulus drop from 115 GPa to 43 GPa after exposure. However the hardness and reduced modulus increased with increasing distance of the shock wave. The phenomenon revealed that shock wave deteriorated the micromechanics properties of soldered samples.