Effects of Y2O3-LaF3on the low temperature sintering and thermal conductivity of AlN ceramics

Purpose Aluminum nitride (AlN) ceramics are suitable substrate and package materials for high-power integrated circuits. Design/methodology/approach Dense AlN ceramics with Y 2 O 3 and LaF 3 as sintering additives are prepared. The effects of these additives on the density, phase composition, microstructure and thermal conductivity of AlN ceramics are investigated. Findings Results show that 2 Wt.% Y 2 O 3 -doped additive is insufficient for the samples to achieve the full densification sintered at 1,700°C. When LaF 3 is added with Y 2 O 3 , the samples are perfectly densified at the same sintering condition. The relative density and thermal conductivity of the samples are 97.8-99.07 per cent and 169.104-200.010 W·m-1·K-1, respectively. The density of the samples and their microstructure, especially the content and distribution of secondary phases, is necessary to control the thermal conductivity of AlN ceramics. Originality/value Y 2 O 3 and LaF 3 additives can effectively promote densification and enhance the thermal conductivity of AlN ceramics in a low sintering temperature, and the AlN ceramics added with Y 2 O 3 -LaF 3 might have potential applications in package materials for high-power integrated circuits.