Ultrasound transducer with reduced cross-talk and method of manufacture

A method for manufacturing an ultrasound transducer device, comprising the steps of:

• mounting a bottom surface of a bulk material layer to a substrate;
• cutting into a top surface of the bulk material layer to create an array of pillars separated by a first set of kerfs that extend partly through a thickness of the bulk material layer, the bulk material layer comprising an acoustically active material;
• filling the first set of kerfs with a low impedance filler to form a composite layer, the low impedance filler having a lower acoustic impedance than the acoustically active material, and then lapping the top surface of the bulk material layer to form a composite layer in the bulk material layer;
• forming a first electrode layer on the top surface of the bulk material layer by patterning electrodes in the first electrode layer and providing an electrical connection for each electrode to an electrical device;
• forming a backing layer on an opposite side of the first electrode layer relative to the bulk material layer, the backing layer being formed such that an outer surface of the backing layer opposite the first electrode layer is substantially parallel to the bottom surface of the bulk material layer;
• removing the substrate from the bulk material layer and lapping the bottom surface of the bulk material until a bottom surface of the composite layer is exposed and is substantially parallel to the outer surface of the backing layer;
• forming a second electrode layer on the bottom surface of the composite layer, patterning electrodes in the second electrode layer and providing an electrical connection for each electrode;
• and
• connecting the second electrodes to an electrical device.

An ultrasonic transducer device, comprising:

• an acoustic layer comprising a two-dimensional array of acoustically active elements;
• a first electrode layer on a first side of the acoustic layer and a second electrode layer on a second side of the acoustic layer, the first electrode layer and the second electrode layer comprising non-parallel electrodes that permit each acoustically active element in the two-dimensional array to be separately addressable by a controller;
• and
• a series of kerfs that separate adjacent acoustically active elements in the two-dimensional array of acoustically active elements of acoustically active elements, the series of kerfs being filled with a low dielectric, low acoustic impedance filler.