Effects of nanoparticles on properties and interface reaction of Sn solder for microelectronic packaging

In this study, the effects of Cu nanoparticles on the melting characteristics, wettability, interfacial reaction and mechanical properties of Sn-xCu (x = 0, 0.3, 0.7, 1.0, 1.5, 2.0) composite solders were investigated. Results show that the properties of the composite solder containing Cu nanoparticles were improved effectively. With the addition of Cu nanoparticles, the melting point of Sn-xCu solder decreased significantly, and the spreading area and the shear strength were increased by 10.3% and 23.2%, respectively. For the performance, the optimal addition of Cu nanoparticles was 0.7%. In addition, the growth of interfacial intermetallic compounds in Sn-xCu/Cu solder joints was inhibited by adding Cu nanoparticles.