Ultrasonic transducer with via formed in piezoelectric element and method of fabricating an ultrasonic transducer including milling a piezoelectric substrate

Abstract

An ultrasonic transducer that includes a delay line, an active piezoelectric element, and interposing metal conductive layer between the delay line and active piezoelectric element. The delay line and active piezoelectric element are joined so that ultrasonic waves may be coupled from the active piezoelectric element into the delay line or from the delay line into the active piezoelectric element. A via is formed, using a milling operation, in the active piezoelectric element to expose the edge of the interposing metal conductive layer between the delay line and active piezoelectric element. A conductive layer makes electrical contact between the interposing metal conductive layer and the surface of the active piezoelectric element to allow an electrical connection to be made from the surface of the active piezoelectric element to the interposing metal conductive layer.