Chip-To-Chip Interconnection by Mechanical Caulking Using Reflowed Sn Bumps

A new chip-to-chip interconnection method utilizing mechanical caulking has been developed recently. In this method, bonding between the chips is achieved by deformation-injection of Au stud bump on a chip into the through via hole in the other chip. In this paper, we introduce a modified caulking technology using reflowed Sn bumps instead Au stud bumps since Sn can be deformed more easily than Au. The chip-to-chip interconnection using reflowed Sn bumps and through via hole electrodes was successfully made at room temperature or at 270degC. The contact resistance of the solder joint was less than 35 mOmega per joint.