An ultrasonic HIFU transducer has a front matching layer formed as a continuous spherical surface. Tiles of spherically curved composite piezoelectric material each having a plurality of acoustic transmit areas are attached to the convex surface of the matching layer to provide a substantially continuous spherical surface of piezoelectric transmitters. A plurality of curved printed circuit boards are mounted behind the piezoelectric material and spaced apart from the back surface of the piezoelectric material to provide an air acoustic backing and an air cooling passageway for the piezoelectric material and the circuit boards. A plurality of compliant metal contacts provide electrical connections between the printed circuit boards and the piezoelectric material and span the passageway. Electrical connections are made to electrodes on the front surface of the piezoelectric material through non- magnetic vias extending through the piezoelectric material.
