LAUSR

Effect of Pr element on the wettability, microstructure, interface morphology and mechanical property of Sn–0.3Ag–0.7Cu–0.5Ga–xPr solder has been studied. The result exhibits that the wettability of solders could significantly be improved by adding an approximate amount of Pr, for the forming of well-distributed PrSn3 IMCs could serve as the sites of heterogeneous nucleation, subsequently leading to the refinement of β-Sn matrix and reducing the growth of IMCs. Therefore, the thickness of the IMC layers at the interface (Cu plate/solder) is reduced, implying that the morphology is optimized. The promotion of mechanical properties is also correlated to the refining of IMC layer.