PB-FREE SOLDER BUMPS WITH IMPROVED MECHANICAL PROPERTIES

摘要

A method of forming a semiconductor device is disclosed. A semiconductor substrate is provided that has a first contact and an undoped electroplated lead-free solder bump (610) formed thereon. A device package substrate is provided that has a second contact and a doped lead-free solder layer (510) on the second contact that includes a dopant. The dopant reduces a solidification undercooling temperature of the undoped lead-free solder bump when the dopant is incorporated into the lead-free solder bump. The undoped electroplated lead-free solder bump and the doped lead-free solder layer are melted thereby incorporating the dopant into the undoped lead-free solder to form a doped solder bump (140). The solder bump provides an electrical connection between the first contact and the second contact.