Abstract: In order to improve the microstructure and mechanical properties of the Sn0.5Ag0.7Cu/Cu joint, by adding Zn element to the Sn0.5Ag0.7Cu solder, changed the intermetallic compound (intermetallic compound, IMC) structure at the joint interface, and the joint shear is strengthened. The ductile fracture characteristics of shear fracture improve the joint shear strength.When the addition of Zn element is 0.4%, the joint shear strength reaches the highest 47.81 MPa.The solder joint of Sn0.5Ag0.7Cu-xZn(x=0, 0.1, 0.4, 0.7, 1) /Cu was studied, the result shows that the addition of Zn element has an inhibitory effect on the growth of the IMC layer in the joint after isothermal aging treatment, and with the increase of aging temperature and aging time, the brittle layer Cu₅Zn₈. It will break until it disappears, so it will not change its composition and structure while improving the performance of the IMC at the joint interface.