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.