Abstract: A semiconductor package comprising: (a) at least one semiconductor device; (b) a metal heat spreader that has at least one surface exposed to ambient and the perimeter of that exposed surface having a seal ring border; (c) a leadframe having a plurality of inner and outer leads, said inner leads interconnected to said semiconductor device; and (d) a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and all of the heat spreader except that exposed surface having the seal ring border.

Abstract: There is provided a leadframe assembly for encapsulation in a polymer resin which prevents post-assembly fracture or swelling of the resin. The leadframe is coated with an adhesion enhancing layer that increases the shear stress required for delamination to in excess of about 3.4 MPa. In combination with this adhesion enhancing layer is a compliant die attach adhesive bonding an integrated circuit device to a central die attach paddle. This compliant die attach adhesive has a compliancy factor, E.multidot.a of less than 1.5 MPa/.degree.C. and a thickness of from about 0.01 mm to about 0.08 mm.

Abstract: Composite materials for electronic packages are disclosed. The composite materials comprise a core layer and first and second cladding layers. The core and cladding layer compositions and thicknesses are selected to maximize thermal and electrical conductivity and to minimize the coefficient of thermal expansion of the composite. The composite material may be employed to fashion the package base, the leadframe, a heat spreader or combinations thereof. In one embodiment, a portion of the first cladding layer is removed so that an electronic device may be mounted directly to a high thermal conductivity core.