Patent ID: 7514290

Claim:
A method for chip-to-wafer integration technology for three-dimensional chip stacking, said method comprising: providing one or more chips; providing a substrate; providing one or more shims; preparing array of one or more cavities over said substrate; wherein walls of said array of one or more cavities is made of a cavity material; said one or more shims are made of a shim material; said shim material has a larger coefficient of thermal expansion than that of said cavity material; said cavity material is molybdenum, tungsten, glass, ceramic, or silicon; said shim material is metal, polymer, phosphor bronze, or liquid; stacking said one or more chips on top of each other over said substrate in each of said array of one or more cavities; wherein dimensions of each of said array of one or more cavities are slightly larger than dimensions of said stacked chips; pushing said stacked chips against one or more of said walls of each of said array of one or more cavities; placing said one or more shims in the gaps between said stacked chips and said walls of each of said array of one or more cavities; applying pressure vertically to said stacked chips over said substrate; laminating by heating up said one or more chips, said one or more shims, said array of one or more cavities, and said substrate; bonding said one or more chips to each other and to said substrate at a bonding temperature; expanding and deforming said one or more shims at said bonding temperature; said deformed one or more shims pushing and aligning said one or more chips to said walls of said array of one or more cavities; holding said one or more chips, with one or more molds, wherein said one or more chips in said stacked chips have different sizes; and removing said array of one or more cavities by removing cavity material after said lamination.