DEVELOPMENT OF HIGH THERMAL-CONDUCTIVITY ALUMINUM NITRIDE CERAMIC

AlN ceramics with densities varying from 3.18 to 3.30 g/cm3 and room-temperature thermal conductivities varying from 88 to 193 W/m . K were produced. Different sintering conditions, packing powders, AlN powder sources, carbon additive and sintering times were evaluated, and the key processing parameters which cause the differences in density and thermal conductivity were identified. SEM, TEM, and EDS were used to characterize the correlation between thermal conductivity, microstructure, and processing parameters. The important parameters which control the thermal conductivity of AlN ceramics are discussed.