# US 8,771,531 B2 · Method of producing substrate for liquid ejection head

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- Number: US 8,771,531 B2
- Document ID: US8771531B2
- Status: Granted
- Kind: B2
- Application number: 13/433,806
- Filed: 2012-03-29
- Published: 2012-10-25
- Granted: 2014-07-08
- Earliest claimed: 2011-04-19
- Assignees: Canon Kabushiki Kaisha
- Applicants: Kenta Furusawa; Shuji Koyama; Hiroyuki Abo; Taichi Yonemoto
- Inventors: Kenta Furusawa; Shuji Koyama; Hiroyuki Abo; Taichi Yonemoto
- Web page: https://patentgrep.com/patent/US8771531B2

## CPC

- B41J 2/1603: {of the front shooter type}
- B41J 2/1629: {wet etching}
- B41J 2/1631: {photolithography}
- B41J 2/1639: {sacrificial molding}
- B41J 2/1645: {thin film formation by spincoating}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A substrate for a liquid ejection head, including: forming a sacrifice layer on a first surface of a silicon substrate in a region in which a liquid supply port is to open, the sacrifice layer containing aluminum which is selectively etched with respect to the silicon substrate; forming an etching mask on a second surface which is a rear surface of the first surface of the silicon substrate, the etching mask having an opening corresponding to the sacrifice layer; a first etching step of etching the silicon substrate by using the etching mask as a mask and by using a first etchant containing 8 mass % or more and less than 15 mass % of tetramethylammonium hydroxide; and after the first etching step, a second etching step of removing the sacrifice layer by using a second etchant containing 15 mass % or more and 25 mass % or less of tetramethylammonium hydroxide.

## Claims

### Claim 1

A method of producing a substrate for a liquid ejection head including a liquid supply port formed therein, comprising:
forming a sacrifice layer on a first surface of a silicon substrate in a region in which the liquid supply port is to open, the sacrifice layer containing aluminum which is selectively etched with respect to the silicon substrate;
forming an etching mask on a second surface which is a rear surface of the first surface of the silicon substrate, the etching mask having an opening corresponding to the sacrifice layer;
a first etching step of etching the silicon substrate by use of the etching mask as a mask and by use of a first etchant containing 8 mass % or more and less than 15 mass % of tetramethylammonium hydroxide; and
after the first etching step, a second etching step of removing the sacrifice layer by use of a second etchant containing 15 mass % or more and 25 mass % or less of tetramethylammonium hydroxide.

### Claim 2 (depends on 1)

The method of producing a substrate for a liquid ejection head according to claim 1, wherein the first etchant contains a first silicon compound.

### Claim 3 (depends on 1)

The method of producing a substrate for a liquid ejection head according to claim 1, wherein the first etchant contains an inorganic alkali metal.

### Claim 4 (depends on 2)

The method of producing a substrate for a liquid ejection head according to claim 2, wherein a concentration of the first silicon compound is 0.5 mass % or more and 8 mass % or less in the first etchant.

### Claim 5 (depends on 1)

The method of producing a substrate for a liquid ejection head according to claim 1, wherein the second etchant contains a second silicon compound.

### Claim 6 (depends on 5)

The method of producing a substrate for a liquid ejection head according to claim 5, wherein a concentration of the second silicon compound is 0.1 mass % or more and 12 mass % or less in the second etchant.

### Claim 7 (depends on 3)

The method of producing a substrate for a liquid ejection head according to claim 3, wherein the inorganic alkali metal comprises one of NaOH, KOH, and CsOH.

### Claim 8 (depends on 1)

The method of producing a substrate for a liquid ejection head according to claim 1, wherein the second etchant contains 15 mass % or more and 22 mass % or less of tetramethylammonium hydroxide.

### Claim 9 (depends on 1)

The method of producing a substrate for a liquid ejection head according to claim 1, wherein the second etchant contains 18 mass % or more and 25 mass % or less of tetramethylammonium hydroxide.

### Claim 10 (depends on 2)

The method of producing a substrate for a liquid ejection head according to claim 2, wherein the concentration of the first silicon compound in the first etchant is 0.8 mass % or more and 8 mass % or less.