Comparison of Aqueous and Non‐Aqueous Tape Casting of Aluminum Nitride Substrates

A direct comparison of aqueous and non‐aqueous tape casting was investigated. Aqueous and non‐aqueous formulations were developed for tape casting of aluminum nitride (AlN) powder. The oxygen content of the AlN powder in aqueous ball‐milling media had a slight increase, but it did not almost influence the thermal conductivity of AlN substrate. The solid loading of aqueous AlN slurry was higher than that of the non‐aqueous one, but its viscosity was lower than that of non‐aqueous AlN slurry. Under the same burnout program, the residual carbon content in aqueous AlN green sheet was lower than that of the non‐aqueous one. The thermal conductivity of the aqueous AlN substrate sintered at 1850°C for 3 h was 138 W·(m·K) −1 , which was close to 142 W·(m·K) −1 of the non‐aqueous AlN substrate.