Ultrasonic-assisted soldering of SAC0307 solder with Nano-particles active-flux

Nano-particles active-flux and ultrasonic were utilized to achieve Cu/Cu joint with low temperature and fast soldering (180s). The shear strength of SAC0307 solder joint can reach 22.15MPa. The thickness of IMCs was not more than 2.5μm in all joints. The micromorphology had no obvious change with the change of ultrasound and NPs. The shear strength of SAC0307 solder joint was increased 47.18% and 34.35% with Nano-Ni particles active-flux and Ni-CNT particles active-flux for ultrasonic time at 3s respectively. The shear strength of all joints was increased first and then decreased with the increase of ultrasonic time. Ultrasound and NPs can improve the shear strength. Ultrasound had greater effects on active-flux joint and Nano-Ni particles active-flux joint, but Ni-CNT particles active-flux joint was the opposite.