US Patent 7473989 Flip-chip package

A flip-chip package comprises a substrate with an opening. A dummy die is disposed onto the substrate corresponding to the opening so as to form a composite chip carrier with a chip cavity. The dummy die has a redistribution layer which includes a plurality of flip-chip pads for flip-chip connection of a chip and a plurality of connecting pads around the dummy die for connecting the substrate. The dummy die mounts at least a chip by flip chip connection for being an electrical interface medium between the chip and the substrate in order to achieve thinner package thickness, high heat dissipation, fine pitch flip-chip mounting and eliminating flip-chip stress on the chip.