This Small Business Innovation Research (SBIR) Phase I project will develop a high thermal conductivity, low coefficient of thermal expansion, and low weight substrate material for optoelectronics packaging. The metal matrix composite (MMC) system uses a high thermal conductivity metallic alloy as the continuous metal matrix and ultra high thermal conductivity particulates as the discrete reinforcement phase. Heat sinks produced using this process are near net shape as fired, requiring minimum machining to meet specifications. The coefficient of thermal expansion (CTE) of the material can be made to match that of the die that will be placed on top. A good match to silicon and to gallium arsenide is obtained by adjusting the composition for the composite. The composite has better properties than other existing MMC substrates systems in the market. It is lighter than Cu/W or Cu/Mo; has better thermal conductivity than Cu/W or Al/SiC; and exhibits a better thermal expansion match to the die than any of them. The uniqueness of this ultra high thermal conductivity metal matrix composite is that the carrier substrates can be better designed to match the thermal expansion characteristics of the chip or other heat-generating components attached to the carrier substrate while also providing improved heat transfer.
Commercially, high thermal conductivity heat sink materials are in high demand in fiber optic components intended for underwater and long haul related applications including amplifiers, receivers, transmitters, tunable lasers, modulators; also for voice and high speed data transmissions and medical and research lasers. Other areas of application include RF power package components that are used in wireless telecommunication infrastructure for cellular phones, base stations, high definition television (HDTV), and satellite communications. The materials also have important applications in advanced automotive or ignition systems intended for aerospace applications, military radar, and guidance systems.
