Patent ID: 6337228
Filing Date: 2002-01-08
Classification: H01L,H05K,Y10T

Abstract:
A method for fabricating a low-cost printed circuit board having an integral heat sink for use in a semiconductor package, comprising:providing a sheet comprising a composite of a fibrous dielectric material impregnated with a thermosetting resin and having a predetermined thickness and generally parallel top and bottom surfaces; forming an opening through the dielectric sheet, the opening having a periphery and defining interior side walls on the sheet inside of the opening that are generally perpendicular to the top and bottom surfaces of the sheet; forming a heat sink of a thermally conductive material, the heat sink having a thickness that is the about the same as the thickness of the dielectric sheet, generally parallel top and bottom surfaces, a periphery that is about the same size and shape as the periphery of the opening in the sheet, and exterior side walls that are generally perpendicular to the top and bottom surfaces of the heat sink; inserting the heat sink in the opening in the dielectric sheet such that the respective top and bottom surfaces of the heat sink and the dielectric sheet are generally coplanar, with the respective exterior side walls of the heat sink and the interior side walls of the dielectric sheet in spaced opposition to each other; placing the heat sink and the dielectric sheet between the platen of a heated press; and, applying heat and pressure to the top and bottom surfaces of the dielectric sheet and heat sink with the press until molten resin flows from the dielectric sheet into the space between the exterior side walls of the heat sink and the interior side walls of the dielectric sheet and solidifies therein.