# US 10,870,276 B2 · Droplet ejector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,276 B2 - Document ID: US10870276B2 - Status: Granted - Kind: B2 - Application number: 16/334,922 - Filed: 2017-09-19 - Published: 2019-09-19 - Granted: 2020-12-22 - Earliest claimed: 2016-09-23 - Applicants: Gregory John McAvoy - Inventors: Gregory John McAvoy - Web page: https://patentgrep.com/patent/US10870276B2 ## CPC - B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm} - B41J 2/161: {of film type, deformed by bending and disposed on a diaphragm} - B41J 2/1628: {dry etching} - B41J 2/1642: {thin film formation by CVD [chemical vapor deposition]} - B41J 2/1646: {thin film formation by sputtering} - B41J 2/164: {thin film formation} - B41J 2002/1437: {Back shooter} - B41J 2002/14491: {Electrical connection} - B41J 2202/13: Heads having an integrated circuit - B41J 2202/15: Moving nozzle or nozzle plate - B41J 2202/18: Electrical connection established using vias - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A droplet ejector for a printhead comprises: a substrate having a mounting surface and an opposite nozzle surface; at least one electronic component integrated with the substrate; a nozzle-forming layer formed on at least a portion of the nozzle surface of the substrate; a fluid chamber defined at least in part by the substrate and at least in part by the nozzle-forming layer, the fluid chamber having a fluid chamber outlet defined at least in part by a nozzle portion of the said nozzle-forming layer; a piezoelectric actuator formed on at least a portion of the nozzle portion of the nozzle-forming layer; and a protective layer covering the piezoelectric actuator and the in nozzle forming layer. The piezoelectric actuator comprises a piezoelectric body provided between first and second electrodes. At least one of the said first and second electrodes is electrically connected to the at least one electronic component. The piezoelectric body comprises one or more piezoelectric materials processable at a temperature below 450° C. ## Claims ### Claim 1 A droplet ejector for a printhead, the droplet ejector comprising: a substrate having a mounting surface and an opposite nozzle surface; at least one electronic component integrated with the substrate; a nozzle-forming layer formed on at least a portion of the nozzle surface of the substrate; a fluid chamber defined at least in part by the substrate and at least in part by the nozzle-forming layer, the fluid chamber having a fluid chamber outlet defined at least in part by a nozzle portion of the said nozzle-forming layer; a piezoelectric actuator formed on at least a portion of the nozzle portion of the nozzle-forming layer, the piezoelectric actuator comprising a piezoelectric body provided between first and second electrodes, at least one of the said first and second electrodes being electrically connected to the at least one electronic component, and the piezoelectric body comprising one or more piezoelectric materials processable at a temperature below 450° C.; and a protective layer covering the piezoelectric actuator and the nozzle-forming layer. ### Claim 2 (depends on 1) The droplet ejector according to claim 1, wherein the one or more piezoelectric materials are depositable at a temperature below 450° C. ### Claim 3 (depends on 1) The droplet ejector according to claim 1, wherein the one or more piezoelectric materials are PVD-deposited piezoelectric materials. ### Claim 4 (depends on 1) The droplet ejector according to claim 1, wherein the one or more piezoelectric materials comprise aluminium nitride and/or zinc oxide. ### Claim 5 (depends on 4) The droplet ejector according to claim 4, wherein the aluminium nitride further comprises one or more of the following elements: scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, boron. ### Claim 6 (depends on 1) The droplet ejector according to claim 1, wherein the piezoelectric body is formed from a ceramic material comprising aluminium and nitrogen and optionally one or more elements selected from: scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, boron. ### Claim 7 (depends on 1) The droplet ejector according to claim 1, wherein the one or more piezoelectric materials are non-ferroelectric piezoelectric materials. ### Claim 8 (depends on 1) The droplet ejector according to claim 1, wherein the piezoelectric body has a piezoelectric constant d31 having a magnitude less than 10 pC/N. ### Claim 9 (depends on 1) The droplet ejector according to claim 1, wherein the at least one electronic component integrated with the substrate consists of at least one CMOS electronic component integrated with the substrate. ### Claim 10 (depends on 1) The droplet ejector according to claim 1, wherein said droplet ejector is a monolithic droplet ejector. ### Claim 11 (depends on 1) The droplet ejector according to claim 1, wherein the nozzle-forming layer comprises a nozzle-plate. ### Claim 12 (depends on 1) The droplet ejector according to claim 1, wherein the nozzle-forming layer comprises an electrical interconnect layer. ### Claim 13 (depends on 12) The droplet ejector according to claim 12, wherein the nozzle-forming layer comprises a nozzle-plate and the electrical interconnect layer is provided between the substrate and the nozzle plate. ### Claim 14 (depends on 12) The droplet ejector according to claim 12, wherein a nozzle portion of the electrical interconnect layer which forms at least a part of the nozzle portion of the nozzle-forming layer consists of dielectric material. ### Claim 15 (depends on 1) The droplet ejector according to claim 1, wherein the mounting surface of the substrate comprises a fluid inlet aperture in fluid communication with the fluid chamber. ### Claim 16 (depends on 1) The droplet ejector according to claim 1, wherein the fluid chamber is substantially cylindrical and the nozzle portion of the nozzle-forming layer is substantially annular. ### Claim 17 (depends on 1) A printhead comprising a plurality of droplet ejectors according to claim 1. ### Claim 18 (depends on 17) The printhead according to claim 17, wherein the plurality of droplet ejectors share a common substrate. ### Claim 19 A method of manufacturing a droplet ejector for a printhead, the method comprising: providing a substrate having a first surface and a second surface opposite the first surface; forming at least one electronic component in or on the second surface of the substrate; forming a nozzle-forming layer on the second surface of the substrate; forming a piezoelectric actuator on the nozzle-forming layer at a temperature below 450° C.; forming a protective layer covering the piezoelectric actuator and the nozzle-forming layer; and forming a fluid chamber in the substrate. ### Claim 20 (depends on 19) The method according to claim 19, wherein the step of forming the piezoelectric actuator comprises: forming a first electrode on the nozzle-forming layer; forming at least one layer of one or more piezoelectric materials on the first electrode at a temperature below 450° C.; and forming a second electrode on the at least one layer of one or more piezoelectric materials. ### Claim 21 (depends on 20) The method according to claim 20, wherein the step of forming the at least one layer of one or more piezoelectric materials comprises depositing the at least one layer of one or more piezoelectric materials by physical vapour deposition at a temperature below 450° C. ### Claim 22 (depends on 20) The method according to claim 20, wherein the one or more piezoelectric materials comprise aluminium nitride and/or zinc oxide. ### Claim 23 (depends on 20) The method according to claim 20, wherein the aluminium nitride further comprises one or more of the following elements: scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, boron. ### Claim 24 (depends on 20) The method according to claim 20, wherein the step of forming the piezoelectric actuator comprises forming a piezoelectric body from a ceramic material comprising aluminium and nitrogen and optionally one or more elements selected from: scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, boron. ### Claim 25 (depends on 20) The method according to claim 20, wherein the one or more piezoelectric materials are non-ferroelectric piezoelectric materials. ### Claim 26 (depends on 19) The method according to claim 19, wherein the step of forming at least one electronic component in or on the second surface of the substrate comprises integrally forming at least one CMOS electronic component in or on the substrate. ### Claim 27 (depends on 19) The method according to claim 19 further comprising integrally forming the substrate, the at least one electronic component, the nozzle-forming layer, the piezoelectric actuator, and the protective layer thereby forming a monolithic droplet ejector. ### Claim 28 (depends on 19) The method according to claim 19, wherein the step of forming the nozzle-forming layer comprises forming a nozzle-plate. ### Claim 29 (depends on 19) The method according to claim 19, wherein the step of forming the nozzle-forming layer comprises forming an electrical interconnect layer. ### Claim 30 (depends on 29) The method according to claim 29, wherein the method comprises: forming the electrical interconnect layer on the second surface of the substrate; and then forming the nozzle-plate on the electrical interconnect layer. ### Claim 31 (depends on 19) A method of manufacturing a printhead comprising forming a plurality of droplet ejectors on a common substrate, each droplet ejector being formed by the method according to claim 19.