Effect of Dispersed SiC Nano-particles in Eutectic Sn58Bi Solder Micro-Bumps of Wafer Level Package by Electroplating

In this paper, the effect of SiC nano-particles in micro-solder bump was investigated. SiC nano-particles were dispersed by using ultrasonic homogenizer in plating solution of eutectic Sn58Bi solder and codeposited in eutectic Sn58Bi solder bumps. Solder bumps were fabricated on patterned wafer. Prepared samples were aged for 100, 256 and 400 hrs at 100°C respectively, and then the observation of microstructure and shear test were carried out to examine SiC particles effects. There was little effect on the growth of intermetallic compound (IMC) between solder bumps and Cu pad; however, microstructure became fine and the value of shear strength increase as much value as 13% due to the suppression of grain coarsening by SiC particles.