A 2.5 MHz 2D array with Z-axis backing

The design, fabrication and initial testing of a prototype fully /spl lambda//2 sampled, 2500 element 2D phased array is presented. The array utilizes a unique Z-axis electrical conductivity backing layer, to provide both acoustic attenuation and electrical interconnect for the signal channels. The electrical interconnect is designed to be in the acoustic shadow of the transducer elements so as to minimize the foot print of the array. A modular, demountable Pad Grid Array interconnect is used to connect to the backing of the array. Results are presented for measurements of the single element properties of electrical impedance, pulse echo waveform and spectrum, directivity and cross talk.