Effects of Dy substitution for Sn on the solderability and mechanical property of the standard near eutectic Sn-Ag-Cu alloy

摘要

In this study, the solderability of Sn–3.5Ag–0.5Cu–xDy solders were investigated and the shear strength properties of joints with Cu substrate were investigated. The results indicated that a small amount Dy addition can improve the solderability, and the optimal amount of Dy was 0.025 wt%. The maximum shear strength can be found with 0.025 wt% Dy addition, improved by 74%. With the observation of the fracture morphology, it was found that a small amount Dy can improve the ductility of the solder joints; but excessive amount of Dy would deteriorate the shear strength and form large dimples on the fracture surface.