Plasticity and creep performance of low-Ag SnAgCuBi-xNi/Cu solder joint

In order to study the effect of Ni on plasticity and creep performance of low-Ag SnAgCuBi-xNi/Cu(x=0,0.05,0.1,0.15,0.2) solder joint, the indentation work and indentation creep were measured and analyzed by nanoindentation method. The results show that adding Ni could improve the hardness of solder joint. Adding amounts of 0.05% and 0.1% Ni is helpful to improve the plasticity performance but produce almost no impacts on creep. A further Ni adding amount (0.15% and 0.2%) can improve the creep resistance at the expense of plasticity. It is found that Ni can improve high temperature stability of SnAgCuBi/Cu solder joints. The creep resisting performance of the solder joints is improved with Ni element increasing after 400 h aging at 150℃. The hardness of solder joints is improved with the Ni addition. The plasticity performance of solder joints with 0.1% Ni content is better than others.