Effect of aging temperature on reliability of soldered joint with Sn-0.7Cu-xFe filler metal

The effects of aging temperature on the tensile strength, fracture morphology and microstructures of soldered joints with Sn-0.7Cu and Sn-0.7Cu-0.05Fe filler metals were investigated. The results show that the morphology of Cu6Sn5 compound in the solder is changed from needle-shape to rod-shape with the increase of aging temperature. The addition of Fe particles can decrease the coarsening degree of Cu6Sn5 in the microstructure of joint with Sn-0.7Cu-xFe solder during the aging process. The tensile strength of soldered joint with Sn-0.7Cu-0.05Fe solder is higher than that with Sn-0.7Cu solder at the same aging temperature. The fracture of joints with Sn-0.7Cu and Sn-0.7Cu-0.05Fe solders are mainly composed of dimple and river cleavage pattern. The fracture mechanism of the joint is changed from plastic fracture to brittle fracture during the range of the aging temperature.