# US 10,118,392 B2 · Fluid feed slot for fluid ejection device

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- Number: US 10,118,392 B2
- Document ID: US10118392B2
- Status: Granted
- Kind: B2
- Application number: 15/947,197
- Filed: 2018-04-06
- Published: 2018-08-16
- Granted: 2018-11-06
- Earliest claimed: 2018-04-06
- Assignees: Hewlett-Packard Development Company, L.P.
- Applicants: Hewlett-Packard Development Company, L.P.
- Inventors: Ed Friesen; Rio Rivas; Kelly Ronk
- Web page: https://patentgrep.com/patent/US10118392B2

## CPC

- B41J 2/162: {Manufacturing of the nozzle plates}
- B23K 26/382: by boring
- B23K 26/402: involving non-metallic material, e.g. isolators
- 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 2/1632: {machining}
- B41J 2/1634: {laser machining}
- B41J 2/1753: {Details of contacts on the cartridge, e.g. protection of contacts}
- B41J 29/393: Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns}
- B23K 2103/08: Non-ferrous metals or alloys
- B23K 2103/10: Aluminium or alloys thereof
- B23K 2103/12: Copper or alloys thereof
- B23K 2103/14: Titanium or alloys thereof
- B23K 2103/42: {Plastics other than composite materials}
- B23K 2103/50: {Inorganic materials other than metals or composite materials}
- B23K 2103/52: {Ceramics}
- B23K 2103/54: {Glass}
- B23K 2103/56: {being semiconducting}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM

## Abstract

A method of forming a substrate for a fluid ejection device includes forming an opening in the substrate from a second side toward a first side, and further forming the opening in the substrate to the first side, including increasing the opening to the first side and increasing the opening at the second side, and forming the opening with substantially parallel sidewalls intermediate the first side and the second side and converging sidewalls to the first side.

## Claims

### Claim 1

A fluid ejection device, comprising:
a substrate having a first side and a second side opposite the first side;
a thin-film structure formed on the first side of the substrate, the thin-film structure having a fluid feed hole formed therethrough; and
a fluid feed slot formed by an opening extending through the substrate between the first side and the second side, the fluid feed slot communicated with the fluid feed hole,
wherein the fluid feed slot has parallel sidewalls intermediate the first side and the second side, converging sidewalls from the parallel sidewalls to the first side, and diverging linear sidewalls sloped from the parallel sidewalls to the second side,
wherein, at the first side, the fluid feed slot, as defined by the converging sidewalls, is wider than the fluid feed hole.

### Claim 2 (depends on 1)

The fluid ejection device of claim 1, wherein a length of the converging sidewalls, as measured in a direction substantially perpendicular to the first side, is in a range of approximately five percent to approximately fifteen percent of a thickness of the substrate.

### Claim 3 (depends on 1)

The fluid ejection device of claim 1, wherein the converging sidewalls are oriented at an angle to the parallel sidewalls and the first side, and the diverging linear sidewalls are oriented at an angle to the parallel sidewalls and the second side.

### Claim 4 (depends on 1)

The fluid ejection device of claim 1, wherein the substrate comprises a silicon substrate, and the converging sidewalls comprise <111>planes of the silicon substrate from the parallel sidewalls to the first side and the diverging linear sidewalls comprise <111>planes of the silicon substrate from the parallel sidewalls to the second side.

### Claim 5 (depends on 1)

The fluid ejection device of claim 1, wherein the fluid feed slot is formed by laser machining followed by anisotropic wet etching.

### Claim 6 (depends on 5)

The fluid ejection device of claim 5, wherein the laser machining comprises laser machining the substrate from the second side toward the first side.

### Claim 7 (depends on 6)

The fluid ejection device of claim 6, wherein the laser machining the substrate comprises laser machining the substrate a first width to a first depth followed by laser machining the substrate a second width for an additional, second depth to form a portion of the opening, wherein the first width is greater than the second width, and the second depth is less than the first depth.

### Claim 8 (depends on 7)

The fluid ejection device of claim 7, wherein the anisotropic wet etching comprises anisotropic wet etching the substrate from the portion of the opening to the first side.

### Claim 9 (depends on 1)

The fluid ejection device of claim 1, wherein the fluid feed slot is formed by laser machining followed by dry etching followed by anisotropic wet etching.

### Claim 10 (depends on 9)

The fluid ejection device of claim 9, wherein the laser machining comprises laser machining the substrate from the second side toward the first side to form a portion of the opening in the substrate.

### Claim 11 (depends on 10)

The fluid ejection device of claim 10, wherein the dry etching comprises dry etching the substrate from the portion of the opening to the first side.