Low and cryogenic temperature mechanical performance and fracture behavior of micro-scale Cu/Sn–3.0Ag–0.5Cu/Cu joints with the decreasing dimension

摘要

Tensile deformation and fracture behavior of micro-scale Cu/Sn–3.0Ag–0.5Cu/Cu joints with a constant diameter of 400 µm and the decreasing thickness (from 400 to 200 and then to 100 μm) were characterized at low and cryogenic temperatures in this study. Results show that with decreasing temperature and joint thickness the joint tensile strength increases. Fracture behavior of solder joints also exhibits a temperature-dependency. As the temperature decreases, there is a shift in the fracture position from the solder matrix to the interface between solder matrix and interfacial Cu6Sn5 layer, the fracture mode changes from ductile to brittle. Moreover, the temperature corresponding to fracture position transition increases with decreasing joint thickness.