Interfacial reaction and properties of Sn0.3Ag0.7Cu containing nano-TiN solder joints

Ultra-low silver Sn0.3Ag0.7Cu (SAC0307) solder is arousing widespread attention because of its low cost. In this paper, the morphology of interfacial intermetallic compounds, microstructure, melting point, wettability and mechanical property of SAC0307 containing nano-TiN solders were investigated using scanning electricity microscope, transmission electron microscopy, micro-joints strength tester and differential scanning calorimetry. Results show that the addition of trace nano-TiN into SAC0307 solder can restrict the growth behavior of interfacial IMC and refine the microstructure of the solder joints. When 0.2 wt% nano-TiN particles were added, the interfacial thickness of SAC0307 solder joint dropped from 2.1 to 1.92 μm. Moreover, the wettability and mechanical property of SAC0307 solder joints were also significantly enhanced, but it has little influence on the melting characteristics of the solder.