Patent ID: 7843112

Claim:
An SH wave type surface acoustic wave device, comprising: a piezoelectric substrate; and an IDT electrode provided on the piezoelectric substrate and constituted of Al or an alloy mainly containing Al, wherein: the device uses a SH wave as an excitation wave; the piezoelectric substrate is a crystal plate in which a cut angle θ of a rotary Y cut quartz substrate is set in a range of −64.0°<θ<−49.3° in a counter-clockwise direction from a crystal axis Z and in which a surface acoustic wave propagation direction is set at 90°±5° with respect to a crystal axis and has an etched trace on a surface thereof, the etched trace being formed by wet etching and running from one side to the other side on the surface; an electrode film thickness H/λ standardized by a wavelength of the IDT electrode is 0.04<H/λ<0.12, where λ is a wavelength of the surface acoustic wave to be excited; and the IDT electrode is provided on an etched surface of the piezoelectric substrate.