Fabrication of Porous AlN from Porous AlN polytypoid

Abstract

Porous AlN was fabricated by carbothermal reduction-nitridation of AlN polytypoid of Si-Al-O-N system. The Thermal conductivity depended on not only the porosity but also the microstructure. In particular, porous AlN ceramics fabricated from the AlN polytypoid with 10wt% SiO₂ addition had high thermal conductivity (50W/mK), high porosity (54%) and low dielectric constant (3.0 at 1MHz). Consequently, this porous AlN ceramics is expected to be used under a high frequency.