Influence of the organic vehicle and inorganic additives on the properties of thick film pastes for AlN

New conductor pastes for AlN as substrate material with fired films of a sheet resistance below 25 mOhm/sq were investigated. The pastes consist of AgPd as conductive phase for leach resistance. Other paste ingredients are glasses of matched composition for adhesion and densification properties, little amounts of inorganic additives and organic vehicles for film deposition. The latter has a significant influence on the paste deposition and the resulting film properties as well. In order to shine light into these relation systematic rheological studies of the organic vehicle and the manufactured pastes were performed. The rheological investigations include measurements in rheological steady-state as well as dynamic experiments. In addition, the solder properties of the fired film were studied. FESEM analyses were performed on the surface of the fired films.