A method is provided for making a backing layer for an ultrasonic matrix
array transducer useful in medical imaging and the like. A conductive
grid is provided which includes a plurality of micro-contacts each joined
together by a common base so that spaces are provided between the free
ends of the contacts. A mold for the grid is filled with an acoustically
absorbent material such that the absorbent material fills the spaces
between the contacts, so as to produce a block when cured. The common
base is removed so as to separate the contacts from one another within
the block. Further machining exposes the opposite ends of micro-contacts
so that a like number of contact faces or pads are provided at opposed
surfaces of the backing layer. Improved transducer constructions are also
disclosed.