# US 10,369,788 B2 · Printhead with recessed slot ends

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- Number: US 10,369,788 B2
- Document ID: US10369788B2
- Status: Granted
- Kind: B2
- Application number: 15/379,562
- Filed: 2016-12-15
- Published: 2017-06-08
- Granted: 2019-08-06
- Earliest claimed: 2016-12-15
- Assignees: Hewlett-Packard Development Company, L.P.
- Applicants: Hewlett-Packard Development Company, L.P.
- Inventors: Rio Rivas; Ed Friesen; Terry McMahon; Donald W. Schulte; David Douglas Hall
- Web page: https://patentgrep.com/patent/US10369788B2

## CPC

- B41J 2/14145: {Structure of the manifold}
- B41J 2/1433: {Structure of nozzle plates}
- B41J 2/1603: {of the front shooter type}
- B41J 2/1628: {dry etching}
- B41J 2/1629: {wet etching}
- B41J 2/1631: {photolithography}
- B41J 2/1634: {laser machining}
- B41J 2/1642: {thin film formation by CVD [chemical vapor deposition]}
- Y10T 29/49401: Fluid pattern dispersing device making, e.g., ink jet
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A fluid ejection device may include a substrate having front and back opposing surfaces and a slot extending through the substrate between the back and front surfaces and along an axis of the substrate. A recessed end region may be formed in the back surface at each end of the slot.

## Claims

### Claim 1

A fluid ejection device comprising:
a substrate having front and back surfaces, wherein the front and back surfaces are opposite surfaces;
a slot extending through the substrate between the back and front surfaces and along a long axis; and
recessed end regions comprising a first recessed end region at a first end of the slot and a second recessed end region at a second end of the slot.

### Claim 2 (depends on 1)

The fluid ejection device of claim 1, wherein the recessed end regions comprise shapes selected from the group consisting of square shapes and rounded shapes.

### Claim 3 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region and the second recessed end region each slope at a single angle from the back surface into the substrate until intersecting the slot.

### Claim 4 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region and the second recessed end region each slope at multiple angles from the back surface into the substrate until intersecting the slot.

### Claim 5 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region and the second recessed end region each extend substantially perpendicularly from the back surface into the substrate and then substantially horizontally until intersecting the slot.

### Claim 6 (depends on 1)

The fluid ejection device of claim 1, further comprising:
recessed side regions comprising a first recessed side region and a second recessed side region, the first recessed side region and the second recessed side region being formed in the back surface along a first side and a second side, respectively, of the slot, wherein the recessed end regions and recessed side regions form a recessed perimeter continuously extending around the slot.

### Claim 7 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region and the second recessed end region are curved.

### Claim 8 (depends on 7)

The fluid ejection device of claim 7, wherein the first recessed end region and the second recessed end region each have extensions extending parallel to the long axis and terminating along sides of the slot.

### Claim 9 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region and the second recessed end region each have extensions extending parallel to the long axis and terminating along sides of the slot.

### Claim 10 (depends on 9)

The fluid ejection device of claim 9, wherein the extensions of the first recess end region extend on opposite sides of the slot towards the second recessed end portion to the first end of the slot and wherein the extensions of the second recessed end region extend on opposite sides of the slot towards the first recess and portion to the second end of the slot.

### Claim 11 (depends on 1)

The fluid ejection device of claim 1 further comprising a hard mask layer on the back-side surface, the hard mask layer having an opening therethrough, the opening encompassing the recessed regions and the length and width of the slot.

### Claim 12 (depends on 11)

The fluid ejection device of claim 11 further comprising a fang feature in a short axis sidewall of the slot, wherein the fang feature is adjacent to the back-side surface, intersects the hard mask layer at a front-side edge of the hard mask layer located in the slot, and is an indentation formed by an intersection of two planes, and wherein the intersection of the two planes is in the substrate such that the indentation extends beyond the width of the slot.

### Claim 13 (depends on 1)

The fluid ejection device of claim 1 further comprising an indentation extending into a short axis sidewall of the slot adjacent to the back-side surface.

### Claim 14 (depends on 13)

The fluid ejection device of claim 13, wherein the indentation is formed by an intersection of two planes, and wherein the intersection of the two planes is in the substrate such that the indentation extends beyond the width of the slot.

### Claim 15 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region is sloped at a single angle from the back surface into the substrate until the first recessed end region intersects the slot.

### Claim 16 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region is sloped at multiple angles from the back surface into the substrate until the first recessed end region intersects the slot.

### Claim 17 (depends on 16)

The fluid ejection device of claim 16, wherein the first recessed end region has a first surface at a first angle oblique to the front surface of the substrate and a second surface at a second angle, different in the first angle, and oblique to the front surface of the substrate.

### Claim 18 (depends on 17)

The fluid ejection device of claim 17, wherein the fluid ejection device comprises a face through which nozzles open, wherein the long axis extends parallel to the face and through the first recessed end region and the second recessed end region, wherein the slot has a width perpendicular to the long axis and wherein the first end region and the second and region are spaced along the long axis by a distance greater than the width.

### Claim 19 (depends on 1)

The fluid ejection device of claim 1, wherein the first recessed end region extends substantially perpendicularly from the back surface into the substrate and then substantially horizontally until the first recessed end region intersects the slot.

### Claim 20 (depends on 1)

The fluid ejection device of claim 1, wherein the fluid ejection device comprises a face through which nozzles open, wherein the long axis extends parallel to the face and through the first recessed end region and the second recessed end region, wherein the slot has a width perpendicular to the long axis and wherein the first end region and the second and region are spaced along the long axis by a distance greater than the width.