# US 10,479,094 B2 · Energy efficient printheads

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- Number: US 10,479,094 B2
- Document ID: US10479094B2
- Status: Granted
- Kind: B2
- Application number: 15/765,255
- Filed: 2016-01-20
- Published: 2018-10-04
- Granted: 2019-11-19
- Earliest claimed: 2016-01-20
- Assignees: Hewlett-Packard Development Company, L.P.
- Applicants: Hewlett-Packard Development Company, L.P.
- Inventors: Zhizhang Chen; Mohammed Shaarawi; Brian Bolf; Paul Krause
- Web page: https://patentgrep.com/patent/US10479094B2

## CPC

- B41J 2/17503: {Ink cartridges}
- B41J 2/14129: {Layer structure}
- B41J 2/1603: {of the front shooter type}
- B41J 2/1642: {thin film formation by CVD [chemical vapor deposition]}
- B41J 2/175: Ink supply systems {; Circuit parts therefor}
- B41J 2/33525: {Passivation layers}
- B41J 2202/03: Specific materials used
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

Energy efficient printheads are disclosed. An example printhead includes a substrate with channels to direct ink toward a plurality of nozzles of the printhead. The example printhead further includes a passivation layer on the substrate. The passivation layer includes a first thin film of a first dielectric material formed using atomic layer deposition.

## Claims

### Claim 1

A printhead comprising:
a substrate with channels to direct ink toward a plurality of nozzles of the printhead; and
a passivation layer on the substrate, the passivation layer including a first thin film of a first dielectric material and a second thin film of a second dielectric material, wherein the first thin film is in direct contact with the second thin film.

### Claim 2 (depends on 1)

The printhead of claim 1, wherein a thickness of the passivation layer is less than or equal to 1500 angstroms.

### Claim 3 (depends on 1)

The printhead of claim 1, wherein a thickness of the first thin film is less than or equal to 200 angstroms.

### Claim 4 (depends on 1)

The printhead of claim 1, wherein the second dielectric material is silicon mononitride.

### Claim 5 (depends on 4)

The printhead of claim 4, wherein the first dielectric material is hafnium oxide.

### Claim 6 (depends on 1)

The printhead of claim 1, wherein the second thin film is disposed between the substrate and the first thin film.

### Claim 7

A printhead, comprising:
a substrate to direct ink to nozzles in the printhead to eject the ink; and
a passivation layer to protect the substrate, the passivation layer including:
a first thin film of a first dielectric material on the substrate having a step coverage greater than or equal to 80%.

### Claim 8 (depends on 7)

The printhead of claim 7, wherein the first thin film is free of pinhole defects.

### Claim 9 (depends on 7)

The printhead of claim 7, wherein a thickness of the passivation layer is less than or equal to 500 angstroms.

### Claim 10 (depends on 7)

The printhead of claim 7, wherein the first thin film corresponds to hafnium oxide formed on the substrate using atomic layer deposition.

### Claim 11 (depends on 7)

The printhead of claim 7, wherein the passivation layer further includes a second thin film of a second dielectric material that is disposed between the substrate and the first thin film, and wherein the first and second thin films are in direct contact with each other.

### Claim 12

A method, comprising:
forming a first thin film of a first dielectric material on a substrate having channels to direct ink toward a plurality of nozzles of a printhead, wherein the first thin film is formed using atomic layer deposition; and
forming a second thin film of a second dielectric material on the first thin film using plasma-enhanced chemical vapor deposition, wherein the first and second thin films are in direct contact.

### Claim 13 (depends on 12)

The method of claim 12, wherein forming the first thin film includes depositing the first dielectric material on the substrate with a step coverage greater than or equal to 80%.

### Claim 14 (depends on 12)

The method of claim 12, wherein the first thin film and the second thin film collectively form a passivation layer that spans a width of the printhead, and wherein forming the first thin film and the second thin film includes depositing the first thin film and the second thin film over the width of the passivation layer.

### Claim 15 (depends on 12)

The method of claim 12, wherein the first thin film and the second thin film collectively form a passivation layer that spans a width of the printhead, and wherein forming the first thin film and the second thin film includes depositing the first thin film and the second thin film to a combined thickness between approximately 300 angstroms and approximately 1000 angstroms.

### Claim 16 (depends on 12)

The method of claim 12, wherein forming the second thin film includes depositing the second dielectric to a thickness between approximately 50 angstroms and approximately 200 angstroms.

### Claim 17 (depends on 12)

The method of claim 12, wherein the first thin film and the second thin film collectively form a passivation layer that spans a width of the printhead, and wherein forming the first thin film and the second thin film includes depositing the first thin film and the second thin film to a combined thickness of less than or equal to 500 angstroms.

### Claim 18 (depends on 12)

The method of claim 12, wherein forming the first thin film includes depositing hafnium oxide on the substrate using atomic layer deposition.

### Claim 19 (depends on 12)

The method of claim 12, wherein forming the second thin film includes depositing silicon mononitride on the substrate using plasma enhanced plasma-enhanced chemical vapor deposition.