Effect of Ti on wettability and interface reaction of Sn0.7Cu lead-free solder

Abstract

The effect of adding Ti in Sn0.7Cu lead-free solder on the wettability and interfacial reaction between the solder and Cu substrate was investigated. The results show that the wettability can be improved by adding Ti in Sn0.7Cu solder, and the spreading area is increased by 5% compared with that of Sn0.7Cu solder. It is also revealed that the growth rate of the interfacial intermetallic compound (IMC) is compressed and the IMC grain size is increased during soldering reaction. With the increase of soldering time, the IMC morphology evolves gradually from scallop-shaped to serration-shaped, and the IMC which dissolves or fractures into the solder bulk is observed.