Wettability and shear strength of Sn-Cu-Ni-xSi3N4 composite solder

Abstract

The wettability and mechanical properties of solder the joint of Sn-Cu-Ni-xSi3N4 had been investigated. In this study, five different silicon nitride (Si3N4) percentage addition were chosen (0 wt. %, 0.25 wt. %, 0.5 wt. %, 0.75 wt. %, and 1.0 wt. %). Contact angle measurement demonstrated that with Si3N4 addition, the wetting perfomances had been improved with the decrease of wettability contact angle. It is believed that the Si3N4 particles suppresses the interfacial IMC growth and thus improves the shear strength. Interfacial IMC thickness measurement and shear strength results showed that with thinner IMC layer (by increasing amount of wt.% of Si3N4), the higher the shear strength of the joint. Fracture surface of sheared samples shows a combination of both brittle and ductile fracture.