Patent ID: 7665202

Claim:
A process for producing a block of low-frequency piezoelectric composite material having rows of superposed ceramic posts embedded in a dielectric material, said processing comprising the following steps: machining a ceramic block so as to form an array of bars of rectangular cross section with parallel axes, held in place by a ceramic layer forming a base; separating the ceramic block into two identical half-blocks by cutting the initial block in a plane perpendicular to the axes of the bars; producing a block of twice the thickness by superposing and assembling the two half-blocks, the superposition being carried out so as to bring the bars of each of the half-blocks face to face, a conducting layer being inserted in the plane of superposition of the two half-blocks; forming rows of ceramic posts from the bars, by making cuts in the ceramic block that are perpendicular to the bars formed during the machining step, the conducting layer lying in the plane of superposition, forming parallel conducting strips connecting all the posts of any one row together; filling empty spaces that separate the ceramic posts with a dielectric material so as to form a block of composite material; eroding the external faces of the block of composite material obtained in the previous step, in order to remove the initially formed ceramic bases; and depositing a layer of conducting material on the external faces of the block of composite material thus produced.