Diffusion bonded interconnect

摘要

A method of interconnecting integrated circuit chips to a substrate during the assembly of a multi-chip module. Instead of forming an electrical and physical bond by reflowing solder bumps attached to the pads of the chips and the substrate, as in flip-chip bonding, thin pads of specially selected dissimilar metals placed on the chips and substrate are connected by a solid-state diffusion bonding process. In one embodiment, the I/O pads on a chip are formed from aluminum or an aluminum alloy and are aligned and placed into physical contact with corresponding metal pads or metal layered pads on a substrate, where the metal is capable of being diffusion bonded to aluminum. The combination of chip(s) and substrate are then heated in a controlled atmosphere at a temperature and for a time sufficient to cause solid-state diffusion bonding to occur.