HPMA modified aluminium nitride powder for aqueous tape casting of AlN ceramic substrates

Aluminum nitride (AlN) is considered one of the most desirable materials for integrated circuits and electronic packaging substrates. However, raw AlN powder reacts easily with water, forming Al(OH)3 or AlOOH on surface hindering development aqueous tape casting process preparing ceramic In this study, hydrolyzed polymaleic anhydride (HPMA) was used to modify powder, which has good water solubility dispersibility. The modified 5 wt.% HPMA remained stable in at least 90 h under magnetic stirring condition 24 ball milling condition, indicating that HPMA-modified resistance hydrolysis. action mechanism revealed. Firstly, -COOH polymer oxide layer underwent a dehydration condensation reaction form compound. Secondly, long chains further coated an anti-hydration thickness about 7.0 nm particles. addition, green sheets were successfully prepared by using without additional dispersants. Subsequently, substrates obtained sintering 1750 ℃ 4 N2 atmosphere pressure 0.2 MPa. relative density thermal conductivity tested be 97.3 % 122 W·m-1·K-1, respectively.