Study on the microstructure and properties of low-Ag Sn-0.3Ag-0.7Cu-0.5Ga solder alloys bearing Pr

摘要

Effect of Pr element on the wettability, micro-structure, 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 PrSn_3 IMCs could serve as the sites of heterogeneous nucleation, subsequently leading to the refinement of (3-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.