High performance piezoceramic films on substrates for high frequency imaging

PZT thick film fabrication process by screen-printing on two substrates (alumina and PZT) is first described. The firing temperature of the PZT layers is only 800/spl deg/C since the composition was modified with lead germanate (PGO). This minimizes lead losses in films during sintering. The characterization of the samples considered as four layer elements (with electrodes) reveals high electromechanical performance of the films (thickness around 40 /spl mu/m) since the measured thickness coupling factor is around 50%. The results are used to simulate single element high frequency transducers with a KLM model where the substrate is directly used as a backing for an integrated device.