Patent ID: 8698580
Filing Date: 2014-04-15
Classification: H03H,Y10T

Abstract:
1. A surface acoustic wave device comprising: a piezoelectric substrate; a plurality of IDTs arranged on the piezoelectric substrate, each of which includes a pair of interdigital electrodes including a plurality of electrode fingers interdigitated with each other; a plurality of first interconnections and a plurality of second interconnections arranged on the piezoelectric substrate, electrically connected to the IDTs, and having potential differences; and a plurality of insulating layers arranged on the piezoelectric substrate, including portions that are located in regions in which the plurality of first interconnections three-dimensionally intersect with the plurality of second interconnections, the plurality of insulating layers being arranged between the plurality of first interconnections and the plurality of second interconnections and being made of a thermosetting resin; wherein the pair of interdigital electrodes of each of the plurality of IDTs are films which have six-fold rotational symmetric spots appearing in an XRD pole figure, and which are defined Al—Cu alloy films including Cu in an amount not greater than a solubility limit at about 25° C.; the thermosetting resin has a curing temperature of about 305° C. to about 350° C.; and the Al—Cu alloy films have a Cu content of about 0% to about 0.2% by weight.