Microwave sintering of glass-frit containing silver powders

Microwaves at 2.45 GHz frequency have been used to selectively sinter Ag-based mixtures of milled glass frits and Ag powders on a glass substrate. The powders, deposited by screen printing, present much higher microwave absorption than the underlying glass, hence they are preferentially heated. Microwave heating selectivity allows maintaining almost unaltered the glass substrate, thus minimizing unwanted Ag diffusion into the glass. The effect of sintering variables, like microwave forward power and processing time are investigated in terms of Ag diffusion and dimensional changes, with respect to conventional sintering.