# US 10,374,141 B2 · Method for producing a piezoelectric multilayer component, piezoelectric multilayer component containing an auxiliary material, and use of an auxiliary material for setting the breaking stress of a piezoelectric multilayer component > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,141 B2 - Document ID: US10374141B2 - Status: Granted - Kind: B2 - Application number: 14/235,441 - Filed: 2012-06-26 - Published: 2014-10-02 - Granted: 2019-08-06 - Earliest claimed: 2011-07-29 - Assignees: Epcos AG - Applicants: Bernhard Döllgast; Wolfgang Athenstaedt; Marion Ottlinger; Marlene Fritz - Inventors: Bernhard Döllgast; Wolfgang Athenstaedt; Marion Ottlinger; Marlene Fritz - Web page: https://patentgrep.com/patent/US10374141B2 ## CPC - H10N 30/508: {adapted for alleviating internal stress, e.g. cracking control layers} - H10N 30/053: by integrally sintering piezoelectric or electrostrictive bodies and electrodes - H10N 30/072: by laminating or bonding of piezoelectric or electrostrictive bodies - H10N 30/852: {Composite materials, e.g. having 1-3 or 2-2 type connectivity} - H10N 30/8554: {Lead-zirconium titanate [PZT] based} - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract Provision is made of a method for producing a piezoelectric multilayer component (1), in which piezoelectric green sheets, at least one ply (21) containing an auxiliary material having a first and a second component and layers (20) containing electrode material are arranged one above another alternately and sintered, wherein, during the sintering, the first and second components of the auxiliary material chemically react, and the at least one ply (21) containing the auxiliary material is degraded. In addition, provision is made of a piezoelectric multilayer component (1) comprising a plurality of alternating layers of electrode material (20) and piezoelectric ceramic and at least one layer (21) of auxiliary material having a breaking load which is reduced compared to the other layers of electrode material, wherein, in addition to the first and second components, the auxiliary material comprises a fifth component, which, at the preferred sintering temperatures for the piezoelectric material, in particular at most 1050° C., at most has a negligible sintering activity and does not react with the piezoelectric material used. Finally, the use of ZrO2, BaTiO3 or a mixture thereof in the auxiliary material layer of a piezoelectric multilayer component for reducing the breaking stress is described. ## Claims ### Claim 1 A method for producing a piezoelectric multilayer component, comprising the steps of: A) providing an electrode material and green sheets containing a piezoelectric material, B) providing an auxiliary material, which contains at least a first and a second component, C) forming a stack (1), in which piezoelectric green sheets, at least one ply containing the auxiliary material and layers containing the electrode material are arranged one above another alternately, D) debinding the stack to produce a low-carbon stack and sintering the low-carbon stack (1), wherein the first and second components of the auxiliary material chemically react during the sintering process of method step D), and the at least one ply is degraded. ### Claim 2 (depends on 1) The method according to claim 1, wherein the electrode material and the auxiliary material are selected in such a way that they contain the same metal, which is present in a smaller proportion in the electrode material than in the auxiliary material. ### Claim 3 (depends on 1, 2) The method according to claim 1 or 2, wherein, in the sintering process of method step D), the first and second components react to form a third component and/or the first component decomposes into a third and a fourth component and the fourth component reacts with the second component to form the first component. ### Claim 4 (depends on 1) The method according to claim 1, wherein, in the sintering process of method step D), the third component and/or the first component diffuse toward at least one of the layers containing electrode material (20). ### Claim 5 (depends on 4) The method according to claim 4, wherein a weakening layer (21) is formed by the diffusion in the region of the ply in the stack (1). ### Claim 6 (depends on 1) The method according to claim 1, wherein CuO is selected as the first component, Cu is selected as the second component and a Cu alloy is selected as the electrode material. ### Claim 7 (depends on 1) The method according to claim 1, wherein the auxiliary material comprises a fifth component, which, at sintering temperatures for the piezoelectric material of at most 1050° C., has no or negligible sintering activity and does not react with the piezoelectric material used. ### Claim 8 (depends on 7) The method according to claim 7, wherein the fifth component is a ceramic material. ### Claim 9 (depends on 7) The method according to claim 7, wherein the fifth component comprises an element selected from the group consisting of zirconium dioxide, barium titanate and a mixture thereof. ### Claim 10 (depends on 7) The method according to claim 7, wherein the fifth component comprises zirconium dioxide. ### Claim 11 (depends on 7) The method according to claim 7, wherein the fifth component has a silicon content of at most 100 ppm. ### Claim 12 (depends on 7) The method according to claim 7, wherein CuO is selected as the first component, Cu is selected as the second component, ZrO2 is selected as the fifth component and a Cu alloy is selected as the electrode material. ### Claim 13 (depends on 7) A piezoelectric multilayer component comprising a plurality of alternating layers of electrode material and piezoelectric ceramic and at least one layer of auxiliary material having a breaking load which is reduced compared to the other layers of electrode material, wherein the auxiliary material is as defined in claim 7. ### Claim 14 (depends on 13) The piezoelectric multilayer component according to claim 13, wherein the multilayer component has a maximum breaking stress of 20 MPa. ### Claim 15 (depends on 13) The piezoelectric multilayer component according to claim 13, wherein the multilayer component has a maximum breaking stress of 10 MPa. ### Claim 16 (depends on 13) The piezoelectric multilayer component according to claim 13, wherein the multilayer component has a maximum breaking stress of 8 MPa.