Thermal and mechanical attachment of a heatspreader to a flip-chip integrated circuit structure using underfill

Abstract

An integrated circuit structure and a method for packaging an integrated circuit are described. The integrated structure includes an integrated circuit that is inverted and solder bump mounted to a substrate. An underfill is used to encapsulate the solder bumps and form a rigid support layer between the integrated circuit and the substrate. A heatspreader, which has larger planar dimensions than the integrated circuit, is centrally attached to an upper surface of the integrated circuit with a thermally conductive material. Lateral portions of the heatspreader extending beyond the edges of the integrated circuit are attached to the substrate and sides of the integrated circuit by a thermally conductive underfill material. The thermally conductive underfill material thus employed, among other things, provides a robust mechanical support to the heatspreader and integrated circuit structure and eliminates the need for additional support structures such as conventional stiffener rings.

Dependencies are inferred from the claim text.