High Conductivity, Low-Cost Aluminum Composite for Thermal Management

Among composite materials, aluminum/graphite and copper/graphite composites are potentially leading materials for use in high-performance electronic systems. The use of aluminum matrix (Al/Gr) composites for packaging material, however, have been severely limited because of the raw material and fabrication costs of the composite. In order to produce an inexpensive packaging material that exhibits high thermal conductivity and low density, Technical Research Associates, Inc. proposes to economically incorporate natural flake graphite in an aluminum matrix. Flake graphite is inexpensive and exhibits high thermal conductivity and low density. A thin molybdenum coating on the surface of the graphite flake will protect the graphite against aluminum reaction and facilitate wetting. A novel technique will be employed to incorporate the graphite flake in molten aluminum. The resulting composite will be less dense and exhibit higher thermal conductivity than aluminum. The coefficient of thermal expansion of the composite may be tailored for specific applications. The composite may also exhibit exceptionally high corrosion resistance.