5I-3 Investigation of a Commercial PZT Thick-Film Composition on Various Substrates for High Frequency Ultrasonic Applications

Within the field of high frequency ultrasound there has been a call for a new technology for fabrication of devices working at higher frequencies and suitable for production in large numbers at a low cost. The technique of screen-printed PZT thick film (TF) has been widely studied as a means to produce miniaturised, integrated devices at a low cost. Nevertheless, the technology has not yet taken the leap from the academic to the industrial world. Since essential properties favoured in high frequency applications are inherent features of the PZT thick film, it is a natural development in high frequency ultrasound to adopt this technology. However, the process of screen printing PZT thick films involves potential problems of thermal matching and chemical compatibility at the processing temperatures between the functional film, the substrate and the electrodes. We present InSensor TF2100 as a PZT TF using the relative permittivity as a quality parameter verifying the performance of this material. The results are compared with the density of the film indicating that the reduction of the properties in the PZT TF is due to porosity. The comparison indicates good performance of the thick film and good compatibility between the PZT TF, the electrode and substrate material