Effects of Ni-coated carbon nanotubes addition on the microstructure and mechanical properties of Sn-Ag-Cu solder alloys

Microstructure and mechanical properties including tensile strength as well as creep resistance of Ni-Coated Carbon Nanotube reinforced Sn-Ag-Cu solders were investigated in this study. Addition of 0.05 wt% Ni-Coated Carbon Nanotubes improved the ultimate tensile strength of composite solder slabs (up to 9.80%) and joints (up to 15.95%). The increase in strengthening effect of solder joints can be attributed to the consumption of Ni by interface reaction during soldering. Nanoindentation results revealed that the creep behaviors of composite solders were improved significantly as compared to that of the unreinforced solder alloy. Finite-element modeling showed that load transfer by Carbon Nanotubes took effect but was far smaller than the effect of Ni-Coated Carbon Nanotubes served as obstacles preventing dislocations gliding.