SURFACE ACOUSTIC WAVE ELEMENT, SURFACE ACOUSTIC WAVE DEVICE, ELECTRONIC CIRCUIT DEVICE, METHOD OF MANUFACTURING THE ELEMENT, AND METHOD OF MANUFACTURING SURFACE ACOUSTIC WAVE DEVICE

摘要

PROBLEM TO BE SOLVED: To make a surface acoustic device small-sized and thin by suppressing corrosion of interdigital electrodes due to a local battery effect. SOLUTION: The surface acoustic wave device has a surface acoustic wave element 11 and packages 9 and 10. The surface acoustic wave element is provided with a piezoelectric single crystal substrate 1, an interdigital electrode 2 provided on one principal surface of the substrate 1, and a back electrode 3 provided on the other surface of the substrate 1. One principal surface 1a provided with the interdigital electrode 2A is made into a negatively charged surface of spontaneous polarization of the piezoelectric single crystal substrate. Packages 9 and 10 have sealing structure of covering the surface acoustic wave element 1 and of enabling water to pass through the packages. COPYRIGHT: (C)2004,JPO&NCIPI