Cu/SnAg Pillar Bump Joints on Ni-Less Surface Finish in Laser Assisted Bonding (LAB)

In this study, interconnects between Ni-less surface-finished Cu pads and Cu/SnAg pillar bumps were formed via a laser assisted bonding (LAB) and the bond properties of the interconnects were evaluated. The LAB process is influenced by the time and power conditions of the laser, affecting the bonding quality and mechanical strength. Under the optimized conditions of the LAB process, it exhibited a higher bonding strength compared to the TCB process. The impact of the Ni-less surface finish on the LAB joint quality was also analyzed.