Method of manufacturing two-dimensional array ultrasonic transducers

摘要

In fabricating a two-dimensional array transducer wherein individual preformed piezoelectric elements are manufactured separately in a high temperature ceramic firing process, a ceramic substrate is provided, having a surface with a plurality of electrodes thereon. A layer of dielectric material is formed on the substrate surface. Holes are formed in the dielectric material layer over the electrodes, defining cavities with metal pads at the bottoms. The individual preformed piezoelectric elements are then inserted into the holes; with one end of each element in contact with a corresponding one of the substrate electrodes. The holes are sized such that the piezoelectric elements are isolated from the dielectric layer. A ground plane conductor is then formed over the dielectric material layer and over the ends of the piezoelectric elements opposite the ends in contact with the piezoelectric elements, and is photolithographically patterned and may be etched to provide a "mesh" structure. The layer of dielectric material may then be removed to provide better isolation between the piezoelectric elements.