Thermal Contact Conductance of Ceramic Substrate Junctions

Abstract

Ceramics have been present within microelectronic packaging since the first integrated circuitry. Ceramics possess an unmatched range of mechanical, electrical, and thermal properties. Due to their low coefficient of thermal expansion and high-temperature stability, metallic oxides, including aluminum oxide and aluminum nitfide, have been used as semiconductor substrates within microelectronic devices. Fletcher and Sparks (1992) conducted an experimental investigation to determine the overall thermal conductance, the thermal contact conductance, and the thermal conductivity of selected porous ceramic materials, including alumina, partially stabilized zirconia, and mullite bonded silicon carbide. At nominal contact pressure, the overall conductance ranged from 15 to 50 W/m2K while the thermal contact conductance data varied from 50 to 110 W/m2K. As the need for more compact integrated circuitry increases, elaborate designs combining ceramic, metallic, and composite materials have been developed. In order to control the thermal dissipation of such devices, the thermal contact conductance of these metallic and