Effect of Er2O3 on the properties of AlN ceramics by tape casting

Abstract

AlN is considered to be a promising substrate and packaging material for high power integrated circuits because of its high thermal conductivity, low dielectric constant, and thermal expansion coefficient close to that of silicon. In this paper, AlN green tape was manufactured by tape casting method. The effect of Er2O3 on the phase composition, thermal conductivity, microstructure and mechanical properties of AlN ceramics has been studied. X-ray diffraction was employed to identify the phases formed during sintering. The results showed that Er2O3 promoted the densification of AlN ceramics due to the formation of liquid phase Er3Al5O12 and ErAlO3. As the sintering temperature increased, one of the second phases Er3Al5O12 disappeared, reacting with Er2O3, and left the other second phase ErAlO3. AlN ceramics, sintered at 1820°C for 3h, presented improved thermal conductivity of 181W/(m•K) and bending strength up to 402MPa.