Effects of Mo nanoparticles on growth of compounds layer and strength of Sn3.0Ag0.5Cu/Cu solder joint during thermal cycling

A new type of composite lead-free solder was prepared by adding Mo nanoparticles in Sn3.0Ag0.5Cu solder. The effects of Mo nanoparticles on the growth behavior of interfacial intermetallic compounds (IMC) layer and tensile strength of solder/Cu joint were investigated during thermal cycling from – 40 ℃ to 125 ℃. It was found that Mo nanoparticles exhibited an inhibition effect on the growth of IMC layer between solder and Cu substrate. After undergoing the same thermal cycling cycles, the thickness of IMC layer in composite solder joint was always thinner than that in Sn3.0Ag0.5Cu solder joint. The influence mechanism of Mo nanoparticles on the growth behavior of IMC layer was analyzed. The tensile tests results showed that the tensile strength of composite solder joint was higher than that of Sn3.0Ag0.5Cu solder joints.