Effects of solder dimension on the interfacial shear strength and fracture behaviors of Cu/Sn–3Cu/Cu joints

Shear fracture behaviors of Cu/Sn–3Cu/Cu joints with different solder dimensions were investigated. The experimental results demonstrate that, with decreasing ratio R of the solder thickness to length, the interfacial shear strength increased and the fracture mode changed from ductile to a mixture of ductile and brittle. Based on the interfacial stress analysis across the solder joint, a hyperbolic formula expressing the relationship between the interfacial shear strength and the ratio R was proposed.