Microstructure and properties of SnAgCu solders bearing Al nano-particles

Al nano-particles were added into the SnAgCu solder to improve the properties. The results indicate that adding small amount of nano-particles can enhance the wettability of the SnAgCu solder,and the mechanical properties of the soldered joints can be improved significantly. However,excessive nanoparticles would reduce the wettability of the solder,and the optimum nano-particles content was about 0.1wt% for the SnAgCu solder. Based on the microstructure examination,it was found that adding nano-particles could obviously refine the microstructure and reduce the dendrite-arm spacing of SnAgCu-xAl solders. In addition, the creep tensile test for the joint made with SnAgCu-xAl solder revealed that the nano-particles could significantly improve the creep rupture life by pinning the dislocations.