Abstract:

The design, fabrication, and measured results for a prototype, two-dimensional, ultrasonic imaging array will be discussed. The active sensor consists of virtually three layers: (1) a piezoelectric 1-3 composite layer; (2) a flex-circuit component; and (3) a special z-axis conductive adhesive which joins them. The sensor construction utilizes electroplated, injection-molded, 1-3 piezoelectric composite as the active layer. Four acoustically thin, flex circuits provide the electrical connections required for addressing the 468 individual array elements. Of key importance to the fabrication process is the use of a composite, b-stage, adhesive film layer, which combines both conductive and nonconductive regions in a pattern-specific orientation within the plane comprising the bond line interface. The conductive regions of the adhesive film are registered with respect to the electroplated sections on both the flex circuit and the 1-3 piezoelectric composite substrate. The transducer array is a reciprocal device operable in both transmit and receive modes. Measured results will include individual element and array calibrations (i.e., transmit and receive responses, beam patterns, and relative phase). [Work supported by ONR 333, Kam Ng.]