# US 10,873,315 B2 · Piezoelectric vibrating piece and piezoelectric device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,315 B2 - Document ID: US10873315B2 - Status: Granted - Kind: B2 - Application number: 15/867,697 - Filed: 2018-01-11 - Published: 2018-07-19 - Granted: 2020-12-22 - Earliest claimed: 2017-01-17 - Assignees: Nihon Dempa Kogyo Co., Ltd. - Applicants: Nihon Dempa Kogyo Co., Ltd. - Inventors: Shigetaka Kaga; Kazuhiro Hirota - Web page: https://patentgrep.com/patent/US10873315B2 ## CPC - H03H 9/132: {characterized by a particular shape} - H03H 9/02062: {Details relating to the vibration mode} - H03H 9/02157: {Dimensional parameters, e.g. ratio between two dimension parameters, length, width or thickness} - H03H 9/10: Mounting in enclosures {(constructional combinations of enclosure with electromechanical and other electronic elements H03H9/0538)} - H03H 9/1021: {the BAW device being of the cantilever type} - H03H 9/177: {of the energy-trap type} - H03H 9/19: consisting of quartz - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract A piezoelectric vibrating piece includes a piezoelectric substrate and excitation electrodes. The excitation electrode includes a main thickness portion and an inclined portion, the main thickness portion has a constant thickness, the inclined portion is formed on a peripheral area of the main thickness portion, the inclined portion gradually decrease in thickness from a part contacting the main thickness portion toward an outermost periphery of the excitation electrode. The inclined portion has a width as an inclination width in a length of 0.84 times or more and 1.37 times or less of a first flexural wavelength and 2.29 times or more and 3.71 times or less of a second flexural wavelength, the first flexural wavelength is a wavelength of a flexure vibration at a fundamental wave of the thickness-shear vibration, the second flexural wavelength is a wavelength of a flexure vibration at a third harmonic of the thickness-shear vibration. ## Claims ### Claim 1 A piezoelectric vibrating piece, comprising: a piezoelectric substrate, formed in a flat plate shape and vibrated in a thickness-shear vibration; and excitation electrodes, formed on respective both principal surfaces of the piezoelectric substrate, wherein the excitation electrodes each include a main thickness portion and an inclined portion, the main thickness portion is formed to have a constant thickness, the inclined portion is formed on a peripheral area of the main thickness portion, the inclined portion is formed to gradually decrease in thickness from a part contacting the main thickness portion toward an outermost periphery of the excitation electrode, and the inclined portion has a width as an inclination width formed in a length of 0.84 times or more and 1.37 times or less of a first flexural wavelength and 2.29 times or more and 3.71 times or less of a second flexural wavelength, wherein the first flexural wavelength is a wavelength of a flexure vibration at a fundamental wave of the thickness-shear vibration, the second flexural wavelength is a wavelength of a flexure vibration at a third harmonic of the thickness-shear vibration. ### Claim 2 (depends on 1) The piezoelectric vibrating piece according to claim 1, wherein the fundamental wave and the third harmonic are simultaneously oscillated to be used. ### Claim 3 (depends on 1) The piezoelectric vibrating piece according to claim 1, wherein the inclination width as the width of the inclined portion is formed in a length of 1.05 times or more and 1.26 times or less of the first flexural wavelength and 2.86 times or more and 3.43 times or less of the second flexural wavelength. ### Claim 4 (depends on 1) The piezoelectric vibrating piece according to claim 1, wherein the excitation electrode has an outer shape formed in a circular shape or an elliptical shape. ### Claim 5 A piezoelectric vibrating piece, comprising: a piezoelectric substrate, formed in a flat plate shape and vibrated in a thickness-shear vibration; a first excitation electrode, formed on one principal surface of the piezoelectric substrate; and a second excitation electrode, formed on another principal surface of the piezoelectric substrate, wherein the first excitation electrode is formed to have an identical thickness as a whole, the second excitation electrode includes a main thickness portion and an inclined portion, the main thickness portion is formed to have a constant thickness, the inclined portion is formed on a peripheral area of the main thickness portion, the inclined portion is formed to gradually decrease in thickness from a part contacting the main thickness portion toward an outermost periphery of the second excitation electrode, the main thickness portion is formed to be thicker than a thickness of the first excitation electrode, and the inclined portion has a width as an inclination width formed in a length of 0.84 times or more and 1.37 times or less of a first flexural wavelength and 2.29 times or more and 3.71 times or less of a second flexural wavelength, wherein the first flexural wavelength is a wavelength of a flexure vibration at a fundamental wave of the thickness-shear vibration, the second flexural wavelength is a wavelength of a flexure vibration at a third harmonic of the thickness-shear vibration. ### Claim 6 (depends on 5) The piezoelectric vibrating piece according to claim 5, wherein the fundamental wave and the third harmonic are simultaneously oscillated to be used. ### Claim 7 (depends on 5) The piezoelectric vibrating piece according to claim 5, wherein the inclination width as the width of the inclined portion is formed in a length of 1.05 times or more and 1.26 times or less of the first flexural wavelength and 2.86 times or more and 3.43 times or less of the second flexural wavelength. ### Claim 8 (depends on 5) The piezoelectric vibrating piece according to claim 5, wherein the excitation electrode has an outer shape formed in a circular shape or an elliptical shape. ### Claim 9 (depends on 1) A piezoelectric device, comprising: the piezoelectric vibrating piece according to claim 1; and a package, on which the piezoelectric vibrating piece is placed. ### Claim 10 (depends on 5) A piezoelectric device, comprising: the piezoelectric vibrating piece according to claim 5; and a package, on which the piezoelectric vibrating piece is placed.