METHOD OF MAKING INTERDIGITAL TRANSDUCERS DEVICE FOR MAKING INTERDIGITAL TRANSDUCERS AND INTERDIGITAL TRANSDUCER

摘要

1455805 Electro-erosion ZAKLADY CERAMIKI RADIOWEJ 13 Jan 1975 [26 Jan 1974] 1299/75 Heading B3V [Also in Divisions H1 and H3] An interdigital transducer is made from a metal layer deposited on a piezoelectric substrate 1 by applying a voltage between a needle 4 applied to the layer and the substrate to vaporize the intervening portion of the metal layer, while causing relative movement between the needle point and the substrate to determine the shape of the elctrodes. As shown, several transducers are made simultaneously by mounting substrates 1, of e.g. lithium iodate with a vacuum deposited layer of gold, on a table 9 movable by screws 5, 6 in mutually perpendicular directions, applying a voltage from a source 8 between the needles 4 and the substrates and moving the table 9 by means of the screws 5, 6 which may be under numerical control. Levers 2 carrying the needles 4 engage pins 3 on a support 10 and a rod 13 connected to the support 10 by links 11 bears on the ends of the levers remote from the needles. The length of the levers is such that the needle point exerts a force of not more than 1 gf. on the substrate. The substrate may comprise other compositions reactive with photochemical substances, such as iodic acid, ethylenediamine tartrate, Seignette's salt or compounds of elements of the groups II and VI with Wurtzite structure.