Abstract: Provided are heat sink BGA packages with thermally enhanced mold compounds to further facilitate heat transfer from the die out of the package. Packages in accordance with the present invention incorporate mold compounds with ceramic fillers. The ceramic filled mold compound facilitates the heat transfer between the encapsulated die and the heat sink, thereby enhancing the thermal performance of the package.

Abstract: Provided is a heat sink designed to constrain warpage during thermal cycling. The heat sink is composed of a picture frame stiffener and a heat spreader lid. The stiffener has a thickness greater than that of the height of a die bonded on a substrate in the package which the heat sink is or is to be used. The increased thickness of the stiffener beyond conventional designs serves to increase its stiffness and thereby enhance its capacity to constrain the substrate to prevent its warpage during thermal cycling. The thickened stiffener is coupled with an elevated heat spreader lid, that is, a heat spreader lid with a elevated central portion configured for engagement with the picture frame stiffener such that a central portion of at least one side of the heat spreader lid extends into the opening in the picture frame stiffener. As a result, the heat spreader lid is in a position to constrain warpage of the package by applying a counter force against a warping die.