Patent ID: 8471435
Filing Date: 2013-06-25
Classification: H01L,H03H,Y10T

Abstract:
1. A boundary acoustic wave device comprising: a piezoelectric substrate; an IDT electrode located on the piezoelectric substrate; a first dielectric layer arranged to cover the IDT electrode and made of a deposited film; and a second dielectric layer located on the first dielectric layer; wherein assuming a wavelength of a boundary acoustic wave to be λ, a normalized film thickness of the IDT electrode is about 10% or more of λ, and a difference between a height of the first dielectric layer, measured from an upper surface of the piezoelectric substrate, above a center of an electrode finger of the IDT electrode and a height of the first dielectric layer, measured from the upper surface of the piezoelectric substrate, above a center of a gap between adjacent electrode fingers is about 5% or less of the wavelength λ.