Hermetic glass sealing of AlN packages for high temperature applications

In this study the feasibility of glass soldering of aluminium nitride (AIN) for the package of silicon carbide semiconductors,vith application temperatures up to 600 degrees C was evaluated. The components used were various commercially available solder glasses and a crystallising three-component glass. Chemical compatibility between the glass and AlN was investigated by means of both thermodynamic calculations and experimental work on solder joints. The Pbo-free three-component glass was stable against AlN. Lead oxide containing glasses showed deleterious reaction with AlN, which can be inhibited by a passivating layer. Additionally the influence of the processing parameters atmosphere and mechanical pressure was investigated Hermeticity of sealed packages could be proved for three glasses allowing high temperature application between 500 and 600 degrees C. (C) 1999 Elsevier Science Limited. All rights reserved.