# US 10,500,853 B2 · Piezoelectric device, liquid ejecting head, and liquid ejecting apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,500,853 B2 - Document ID: US10500853B2 - Status: Granted - Kind: B2 - Application number: 15/954,860 - Filed: 2018-04-17 - Published: 2018-10-18 - Granted: 2019-12-10 - Earliest claimed: 2017-04-18 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Masao Nakayama; Eiju Hirai; Naoto Yokoyama; Motoki Takabe; Yoichi Naganuma - Web page: https://patentgrep.com/patent/US10500853B2 ## CPC - B41J 2/14201: {Structure of print heads with piezoelectric elements} - B41J 2/045: by pressure, e.g. electromechanical transducers - B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm} - H10N 30/706: {characterised by the underlying bases, e.g. substrates} - H10N 30/87: Electrodes or interconnections, e.g. leads or terminals - B41J 2002/14241: {having a cover around the piezoelectric thin film element} - B41J 2002/14419: {Manifold} - B41J 2202/11: characterised by specific geometrical characteristics - H10N 30/06: Forming electrodes or interconnections, e.g. leads or terminals - H10N 30/082: by etching, e.g. lithography - H10N 30/2047: {Membrane type} - H10N 30/8554: {Lead-zirconium titanate [PZT] based} - H10N 30/877: {Conductive materials} - H10N 30/878: {the principal material being non-metallic, e.g. oxide or carbon based} - H10N 30/883: {Additional insulation means preventing electrical, physical or chemical damage, e.g. protective coatings} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A piezoelectric device including a pressure chamber, a piezoelectric element, and a vibration plate, in which the piezoelectric element is provided with a first electrode, a second electrode, and a piezoelectric layer, the vibration plate has a first portion overlapping the piezoelectric element and a second portion having a thickness smaller than that of the first portion and overlapping an inner peripheral surface of a side wall of the pressure chamber, a side surface of the piezoelectric element which intersects the vibration plate has a first surface inclined at a first angle, the vibration plate has a second surface, between the first portion and the second portion, inclined at a second angle smaller than the first angle, and an end portion of the second surface on the side wall side of the pressure chamber overlaps the side wall of the pressure chamber. ## Claims ### Claim 1 A piezoelectric device comprising: a pressure chamber; a piezoelectric element; and a vibration plate arranged between the pressure chamber and the piezoelectric element and forming a wall surface which intersects a side wall of the pressure chamber, wherein the piezoelectric element is provided with a first electrode on the vibration plate side, a second electrode on an opposite side of the vibration plate with respect to the first electrode, and a piezoelectric layer interposed between the first electrode and the second electrode, the vibration plate has a first portion overlapping the piezoelectric element in a plan view and a second portion having a thickness smaller than that of the first portion and overlapping an inner peripheral surface of the side wall of the pressure chamber in a plan view, a side surface of the piezoelectric element which intersects the vibration plate, has a first surface inclined at a first angle with respect to a surface of the vibration plate on the pressure chamber side, the vibration plate has a second surface, between the first portion and the second portion, inclined at a second angle smaller than the first angle with respect to the surface of the vibration plate on the pressure chamber side, wherein the second angle is greater than zero degrees, and an end portion of the second surface of the vibration plate overlaps the side wall of the pressure chamber in a plan view. ### Claim 2 (depends on 1) The piezoelectric device according to claim 1, wherein the second electrode has a third surface inclined at a third angle with respect to a surface of the vibration plate on the pressure chamber side, and the third angle is smaller than the second angle. ### Claim 3 (depends on 2) A liquid ejecting head comprising: the piezoelectric device according to claim 2, wherein the piezoelectric device changes a pressure of the pressure chamber to eject liquid filled in the pressure chamber from a nozzle. ### Claim 4 (depends on 1) The piezoelectric device according to claim 1, wherein the second electrode has a third surface inclined at a third angle with respect to a surface of the vibration plate on the pressure chamber side, and the third angle is larger than the second angle and smaller than the first angle. ### Claim 5 (depends on 1) The piezoelectric device according to claim 1, wherein the pressure chamber and the piezoelectric element are elongated in a first direction, and a second angle of the second surface is smaller at a central portion side than at an end portion side in the first direction. ### Claim 6 (depends on 1) The piezoelectric device according to claim 1, wherein the pressure chamber and the piezoelectric element are elongated in a first direction and a width of the second surface in a second direction which intersects the first direction is larger at a central portion side than at an end portion side in the first direction. ### Claim 7 (depends on 1) The piezoelectric device according to claim 1, wherein the second electrode overlaps inside the piezoelectric layer from a peripheral portion of a surface on the second electrode side in a plan view. ### Claim 8 (depends on 1) The piezoelectric device according to claim 1, wherein the piezoelectric element and the vibration plate have a protective film. ### Claim 9 (depends on 8) The piezoelectric device according to claim 8, wherein the protective film is continuous so as to cover the end portion of the second electrode and the first surface. ### Claim 10 (depends on 8) The piezoelectric device according to claim 8, wherein the protective film is continuous so as to cover an end portion of the second electrode, the second surface, and the first surface. ### Claim 11 (depends on 1) The piezoelectric device according to claim 1, wherein a portion of the surface of the vibration plate on the pressure chamber side which forms a wall surface of the pressure chamber is flat when the piezoelectric element is not driven. ### Claim 12 (depends on 1) The piezoelectric device according to claim 1, wherein a portion of the surface of the vibration plate on the pressure chamber side which forms the wall surface of the pressure chamber is bent toward the pressure chamber side of the vibration plate when the piezoelectric element is not driven. ### Claim 13 (depends on 1) A liquid ejecting head comprising: the piezoelectric device according to claim 1, wherein the piezoelectric device changes a pressure of the pressure chamber to eject liquid filled in the pressure chamber from a nozzle. ### Claim 14 (depends on 1) A liquid ejecting apparatus comprising: the piezoelectric device according to claim 1, wherein the piezoelectric device changes a pressure of the pressure chamber to eject liquid filled in the pressure chamber from a nozzle. ### Claim 15 A piezoelectric device comprising: a pressure chamber; a piezoelectric element; and a vibration plate arranged between the pressure chamber and the piezoelectric element and forming a wall surface which intersects a side wall of the pressure chamber, wherein the piezoelectric element is provided with a first electrode on the vibration plate side, a second electrode on an opposite side of the vibration plate with respect to the first electrode, and a piezoelectric layer interposed between the first electrode and the second electrode, the vibration plate has a first portion overlapping the piezoelectric element in a plan view and a second portion having a thickness smaller than that of the first portion and overlapping an inner peripheral surface of the side wall of the pressure chamber in a plan view, and a side surface of the piezoelectric layer which intersects the first electrode has a first surface inclined at a first angle with respect to a surface of the vibration plate on the pressure chamber side and a second surface inclined at a second angle smaller than the first angle, wherein the second angle is greater than zero degrees. ### Claim 16 (depends on 15) A liquid ejecting head comprising: the piezoelectric device according to claim 15, wherein the piezoelectric device changes a pressure of the pressure chamber to eject liquid filled in the pressure chamber from a nozzle. ### Claim 17 A piezoelectric device comprising: a pressure chamber; a piezoelectric element; and a vibration plate arranged between the pressure chamber and the piezoelectric element and forming a wall surface which intersects a side wall of the pressure chamber, wherein the piezoelectric element is provided with a first electrode on the vibration plate side, a second electrode on an opposite side of the vibration plate with respect to the first electrode, and a piezoelectric layer interposed between the first electrode and the second electrode, the first electrode has a first portion overlapping the piezoelectric layer in a plan view and a second portion having a thickness smaller than that of the first portion and overlapping an inner peripheral surface of the side wall of the pressure chamber in a plan view, a side surface of the piezoelectric layer which intersects the first electrode has a first surface inclined at a first angle with respect to a surface of the vibration plate on the pressure chamber side, the first electrode has a second surface, between the first portion and the second portion, inclined at a second angle smaller than the first angle with respect to a surface of the vibration plate on the pressure chamber side, and an end portion of the second surface of the vibration plate overlaps the side wall of the pressure chamber in a plan view. ### Claim 18 (depends on 17) A liquid ejecting head comprising: the piezoelectric device according to claim 17, wherein the piezoelectric device changes a pressure of the pressure chamber to eject liquid filled in the pressure chamber from a nozzle. ### Claim 19 A piezoelectric device comprising: a pressure chamber; a piezoelectric element; and a vibration plate arranged between the pressure chamber and the piezoelectric element and forming a wall surface which intersects a side wall of the pressure chamber, wherein the piezoelectric element is provided with a first electrode on the vibration plate side, a second electrode on an opposite side of the vibration plate with respect to the first electrode, and a piezoelectric layer interposed between the first electrode and the second electrode, the first electrode has a first portion overlapping the piezoelectric layer in a plan view and a second portion having a thickness smaller than that of the first portion and overlapping an inner peripheral surface of the side wall of the pressure chamber in a plan view, and a side surface of the piezoelectric layer which intersects the first electrode has a first surface inclined at a first angle with respect to a surface of the vibration plate on the pressure chamber side and a second surface inclined at a second angle smaller than the first angle. ### Claim 20 (depends on 19) A liquid ejecting head comprising: the piezoelectric device according to claim 19, wherein the piezoelectric device changes a pressure of the pressure chamber to eject liquid filled in the pressure chamber from a nozzle.