Effect of SAC0307 content on properties of Cu/Zn powder/Al joint by ultrasonic excitation at low temperature

The ultrasonic-assisted soldering joint of Cu/Zn powder+xSAC0307/Al(x=0%, 5%, 10%, 15%, 20%) at low temperature was studied. In this study, 45μm Zn powder were the main solder, and a small amount of 500nm SAC0307 was mixed into it as the final solder, the soldered was heated to 240°C in environmental atmosphere under the ultrasonic-assisted, successfully realized bonding of Cu/Al at low temperature. The results show that a complete and continuous CU 5 Zn 8 compound was formed at the copper side interface, a solid solution bonding was formed between the base metal and Zn at the aluminum side. When there was no SAC0307, the bonding between Zn balls in the sorlder was weak, the gap between Zn balls was obvious, and the shear strength of the joint was only 21MPa. When the content of SAC0307 was 15%, tin was melted and extruded to the interface of base metal under pressure, the Zn balls were bonded tightly without defects, and the shear strength of the joint reached the maximum value of 39.51MPa.