AlON phase formation in a tape-cast Al2O3/AlN composite

Whilst the use of Al2O3 substrates by tape casting for multilayer ceramics packaging has been well established, the increasing demand for higher perfo rmance has resulted in a composite approach whereby AlN is added as a compo site phase. The phase transformation in a tape-cast Al2O3/AlN composite sub strate thus forms the subject of this investigation. Experimental results s howed that the reaction of the two phases became significant after 1550 deg rees C, forming a new phase AlON as sintering proceeded. Higher sintering t emperatures induced a greater amount of AlON in the sintered Al2O3/AlN tape s. This third phase was due to the presence of MgO, which promoted the form ation of AlON in sintered tapes even in the presence of purge gases. (C) 19 99 Published by Elsevier Science S.A. All rights reserved.