Development of glass frit free metallization systems for AIN

Currently only glass bonding thick film conductor systems are commercially available for metallizing AIN-ceramic. The glass phase formed between metallization and ceramic impairs the high thermal conductivity of AIN. A new glass frit free metallization system has been developed utilizing the bonding mechanism of active brazing to provide the adhesion of metallization onto the ceramic. Aspects of paste preparation range from the derivation of the metallic powder to the selection of an appropriate printing vehicle which must decompose completely during the firing process under an inert atmosphere. The adhesion strength of the new paste system with the alternative bonding mechanism has been evaluated and contrasted with that of standard thick film pastes. (C) 1998 Kluwer Academic Publishers.