Patent ID: 10355668

Abstract:
An acoustic wave device includes: a Y-cut X-propagation lithium tantalate substrate having a cut angle of 20° or more and 48° or less; and a grating electrode that is composed of one or more metal films laminated on the substrate, and excites an acoustic wave, wherein when a density of each metal film in the one or more metal films is represented by ρi, a Poisson's ratio of each metal film is represented by Pi, a film thickness of each metal film is represented by hi, a density of Cu is represented by ρ0, a Poisson's ratio of Cu is represented by P0 and a pitch is represented by λ, a total value of “(hi/λ)×(ρi/ρ0)×(Pi/P0)” for each metal film with respect to the one or more metal films is more than 0.08.