Abstract：Electrochemical deposition is a good method for preparing high-performance and high-reliability Au-30 at% Sn eutectic alloy packaging materials. In this paper, the constant current method was used to deposit Au-Sn eutectic alloy film from a cyanide-free Au-Sn electroplating bath. Through electrochemical testing, alloy film composition and morphology analysis, and multiple batch reproducibility experiments, it was determined that Au-30 at% Sn eutectic alloy film with a smooth and compact surface and a stable Sn atom content of about 30 at% can be deposited at a current density of -2.0 mA/cm2. The differential thermal analysis curve (DSC) showed that the eutectic point temperature of the Au-Sn eutectic alloy film was 277.4 ℃, which was consistent with the theoretical value. In addition, the deposition rate of the Au-Sn eutectic alloy film was about 5.0 μm/h, and the cyanide-free Au-Sn electroplating solution had a good storage life.
2022, Vol. 29 