Two-dimensional array transducers using hybrid connection technology

A new electrical connection technique for 2-D array transducers is reported. It consists of 16*16=256 PZT 5H elements operating at 2.5 MHz fabricated by hand wiring. The connection technique employs a multilayer ceramic (MLC) connector (thick-film hybrid microelectronic technology) consisting of 20 thick films of alumina and screen printed metallization with customized interconnections between the layers called vias. Ten ground layers are interleaved between ten signal layers to reduce electrical cross-talk. A lambda /4 mismatching layer of conductive epoxy is bonded between each PZT element and the silver metal pad of the MLC connector to provide a low impedance backing. Vector impedance, sensitivity, and bandwidth are all in good agreement between conventional fabrication and the MLC connector. Interelement cross-talk is improved by 10 dB.<>