Abstract: A printed wiring board structure having at least one chip-carrying layer adjacent a core fabricated of a metal matrix having disposed therein continuous pitch based graphite fibers. The chip carrying layers and the core have an interface therebetween and are integrally connected to each other through vias plated with an electrically and thermally conductive material to thereby provide a plurality of connection sites along this interface. The matrix is preferably fabricated of aluminum. Preferred fibers are fabricated of pitch based graphite. A substantial weight savings over a common molybdenum core printed wiring board is realized due to the significant reduction in density of the core material.