Ceramic/polymer 2-2 composites for high frequency transducers by tape casting

The aim of this research is to produce 2-2 PZT/polymer composite using tape casting technology. PZT tapes were printed with a fugitive phase (carbon) to define voids which were then backfilled with epoxy after the carbon was removed by thermal treatment at 1250/spl deg/C. Final dimensions of the 2-2 composite were in the range of 25 /spl mu/m for the ceramic bar and 5 /spl mu/m for the epoxy-filled kerf. Specific emphasis was placed on achieving uniformity and straightness of the ceramic beam and kerf thicknesses. The composites were fabricated into 20 MHz single element pachymeters and benchmarked against commercial devices fabricated by dice-and-fill. The tape cast material compared favorably with high sensitivity and a little lower bandwidth. Fabrication of a 35 MHz linear array transducer is in progress. Electrode patterning to define individual array elements has been successfully completed.