Piezoelectric bulk wave device, and method of manufacturing the piezoelectric bulk wave device

摘要

A piezoelectric bulk wave device that includes a piezoelectric thin plate that is made of LiTaO3, and first and second electrodes that are provided in contact with the piezoelectric thin plate. The piezoelectric bulk wave device utilizes the thickness shear mode of the piezoelectric thin plate made of LiTaO3. The first and second electrodes are each formed by a conductor having a specific acoustic impedance higher than the specific acoustic impedance of a transversal wave that propagates in LiTaO3. When the sum of the film thicknesses of the first and second electrodes is defined as an electrode thickness, and the thickness of the piezoelectric thin plate made of LiTaO3 is defined as an LT thickness, the electrode thickness/(electrode thickness+LT thickness) is in the range of not less than 40% and not more than 95%.

主权项

1. A piezoelectric bulk wave device comprising:
a piezoelectric plate that is made of LiTaO3; and first and second electrodes provided in contact with the piezoelectric thin plate, wherein the piezoelectric bulk wave device utilizes a thickness shear mode of the piezoelectric plate made of LiTaO3, wherein the first and second electrodes each comprise a conductor having a specific acoustic impedance higher than a specific acoustic impedance of a transversal wave that propagates in the LiTaO3, wherein, when a sum of film thicknesses of the first and second electrodes is defined as an electrode thickness, and a thickness of the piezoelectric plate made of LiTaO3 is defined as an LT thickness, an electrode thickness/(electrode thickness+LT thickness) is in a range of not less than 40% and not more than 95%, and wherein of Euler Angles (φ, θ, φ) of the LiTaO3, φ is 0°, and θ is in a range of not less than 54° and not more than 107°.