Enhancement of SAC105 solder for vacuum soldering with Cu substrates through incorporation of activated Ti nanoparticles

Abstract

This study incorporated activated Ti nanoparticles (Ti NPs) into Sn1·0Ag0·5Cu (SAC105) solder for vacuum soldering with Cu substrates. The wettability, microstructure, interfacial, and mechanical properties of SAC105-xTi (x = 0.1, 0.2, 0.3, 0.4, 0.5 wt%) composite solder were systematically investigated. The results showed that adding Ti NPs improved the wettability of SAC105 solder, in which the wetting angle of SAC105-0.3Ti solder was 19.51°. Additionally, Ti NPs helped to refine the microstructure and inhibited the growth of interfacial intermetallic compounds (IMC). The shear strength of SAC105/Cu joints increased and then decreased with increasing Ti NPs content, and the optimum shear strength was obtained for SAC105-0.3Ti/Cu joints at 27.98 MPa. The strength of the solder matrix and the IMC layer was altered by adding Ti NPs, resulting in a modification of the fracture path of the joint, bringing it closer to the IMC layer. Excessive addition of Ti NPs could lead to their agglomeration within the joints and result in damage to the mechanical properties of the joints. Furthermore, adding Ti NPs increased the microhardness of SAC105 solder.

Keywords

• Vacuum soldering
• Mechanical properties
• Fracture path
• Agglomeration