# US 10,766,256 B2 · Liquid ejection head substrate, method of manufacturing same and liquid ejection head > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,766,256 B2 - Document ID: US10766256B2 - Status: Granted - Kind: B2 - Application number: 16/369,287 - Filed: 2019-03-29 - Published: 2019-10-10 - Granted: 2020-09-08 - Earliest claimed: 2018-04-04 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Soichiro Nagamochi; Yuzuru Ishida - Web page: https://patentgrep.com/patent/US10766256B2 ## CPC - B41J 2/14129: {Layer structure} - B41J 2/14072: {Electrical connections, e.g. details on electrodes, connecting the chip to the outside...} - B41J 2/1601: {Production of bubble jet print heads (B41J2/1606, B41J2/162 take precedence)} - B41J 2/1603: {of the front shooter type} - B41J 2/1629: {wet etching} - B41J 2/1642: {thin film formation by CVD [chemical vapor deposition]} - B41J 2/1646: {thin film formation by sputtering} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract Provided is a liquid ejection head substrate having a base, a heat generating resistor layer formed on or above the base and including an electrothermal conversion portion, a wiring electrically connected to the heat generating resistor layer and defining the electrothermal conversion portion and a protecting film covering at least the electrothermal conversion portion and the wiring of the heat generating resistor layer. In the liquid ejection head substrate, the wiring is made of an alloy containing Al as a main component and Cu and having an average crystal grain size of 300 nm or less. ## Claims ### Claim 1 A liquid ejection head substrate comprising: a base; a heat generating resistor layer formed on or above the base and including an electrothermal conversion portion for generating heat and bubbling the liquid for ejection; a wiring electrically connected to the heat generating resistor layer and defining the electrothermal conversion portion; and a protecting film covering at least the electrothermal conversion portion and the wiring of the heat generating resistor layer, wherein the wiring has an alloy containing Al as a main component and Cu and having an average crystal grain size of 300 nm or less. ### Claim 2 (depends on 1) The liquid ejection head substrate according to claim 1, wherein the average crystal grain size is 50 nm or more. ### Claim 3 (depends on 1) The liquid ejection head substrate according to claim 1, wherein an end surface of the wiring adjacent to the electrothermal conversion portion is tapered. ### Claim 4 (depends on 1) The liquid ejection head substrate according to claim 1, wherein the average crystal grain size is 100 nm or less. ### Claim 5 A method of manufacturing a liquid ejection head substrate comprising: a step of forming a heat generating resistor layer including an electrothermal conversion portion for generating heat and bubbling the liquid for ejection on or above a base; a step of forming a wiring to be electrically connected to the heat generating resistor layer and defining the electrothermal conversion portion; and a step of forming a protecting film covering at least the electrothermal conversion portion and the wiring of the heat generating resistor layer, wherein the step of forming a wiring comprises: a step of forming a film for wiring having an alloy containing Al as a main component and Cu and having an average crystal grain size of 300 nm or less; and a step of wet etching the film for wiring into the wiring. ### Claim 6 (depends on 5) The method of manufacturing the liquid ejection head substrate according to claim 5, wherein the average crystal grain size is 50 nm or more. ### Claim 7 (depends on 5) The method of manufacturing the liquid ejection head substrate according to claim 5, wherein in the film forming step, the film for wiring is formed by sputtering and in the sputtering, a stage temperature is set at 100° C. or less. ### Claim 8 (depends on 7) The method of manufacturing the liquid ejection head substrate according to claim 7, wherein the stage temperature is set at 30° C. or more. ### Claim 9 (depends on 5) The method of manufacturing the liquid ejection head substrate according to claim 5, wherein in the film forming step, the film for wiring is formed by sputtering and in the sputtering, a DC power per target unit area is set at 12.6 W/cm2 or less. ### Claim 10 (depends on 9) The method of manufacturing the liquid ejection head substrate according to claim 9, wherein the DC power per target unit area is set at 1.2 W/cm2 or more. ### Claim 11 A liquid ejection head comprising: a liquid ejection head substrate having a base, a heat generating resistor layer formed on or above the base and including an electrothermal conversion portion for generating heat and bubbling the liquid for ejection, a wiring electrically connected to the heat generating resistor layer and defining the electrothermal conversion portion, and a protecting film covering at least the electrothermal conversion portion and the wiring of the heat generating resistor layer; and a member having therein an ejection orifice for ejecting a liquid, wherein the wiring has an alloy containing Al as a main component and Cu and having an average crystal grain size of 300 nm or less. ### Claim 12 (depends on 11) The liquid ejection head according to claim 11, wherein the average crystal grain size is 50 nm or more. ### Claim 13 (depends on 11) The liquid ejection head according to claim 11, wherein an end surface of the wiring adjacent to the electrothermal conversion portion is tapered. ### Claim 14 (depends on 11) The liquid ejection head according to claim 11, wherein the average crystal grain size is 100 nm or less.