Printhead with recessed slot ends

Patent metadata

Field	Value
Publication number	US-9707586-B2
Application number	US-201214374160-A
Country	US
Kind code	B2
Filing date	Mar 16, 2012
Priority date	Mar 16, 2012
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

In an embodiment, a method of forming a printhead includes forming on a front-side surface of a substrate, a thin film layer and a plurality of fluidic channels and ejection chambers. The method also includes forming a slot through the substrate from the back-side surface to the front-side surface, where the back-side and front-side surfaces generally oppose one another. The slot has a length extending along a long axis of the substrate and a width extending along a short axis of the substrate. The method includes forming recessed regions into the back-side surface of the substrate at both ends of the slot that extend beyond the length of the slot.

First claim

What is claimed is:

1. A method of forming a printhead comprising:
forming on a front-side surface of a substrate, a thin film layer and a plurality of fluidic channels and ejection chambers;
forming a masking layer on the back-side surface of the substrate;
forming a slot through the substrate from a back-side surface to the front-side surface, the back-side and front-side surfaces generally opposing one another, wherein the slot has a length extending along a long axis of the substrate and a width extending along a short axis of the substrate;
forming recessed regions into the back-side surface of the substrate at both ends of the slot that extend beyond the length of the slot; and
forming a fang feature in a short axis sidewall of the slot, wherein the fang feature is adjacent to the back-side surface, intersects the masking layer at a front-side edge of the masking 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.

2. The method of claim 1 , further comprising controlling features of the recessed regions and fang features with a relationship dimension of the masking layer width relative to a deep laser machined location and a wet etch time.

3. The method of claim 1 , comprising:
prior to forming the slot, forming a patterned hard mask layer on the back-side surface of the substrate that leaves an exposed area of the back-side surface of the substrate sufficient to encompass the recessed regions and the length and width of the slot; and
forming a patterned photo resist layer that covers the hard mask layer and a portion of the exposed area of the back-side surface of the substrate.

4. The method of claim 3 , comprising:
dry etching a trench into the back-side surface of the substrate using the patterned photo resist layer; and
removing the patterned photo resist layer.

5. The method of claim 3 , comprising:
dry etching the exposed area of the back-side surface of the substrate to form the recessed regions and to form the slot by extending the trench through the front-side surface of the substrate.

6. The method of claim 1 , comprising forming a recessed end region in the back surface at each end of the slot.

7. The method of claim 6 , wherein the recessed end region comprises shapes selected from the group consisting of square shapes and rounded shapes.

8. The method of claim 6 , comprising sloping the recessed end region at a single angle from the back surface into the substrate until the recessed end region intersects the slot.

9. The method of claim 6 , comprising sloping the recessed end region at multiple angles from the back surface into the substrate until the recessed end region intersects the slot.

10. The method of claim 6 , comprising forming a recessed side region in the back surface along both sides of the slot, wherein the recessed end region and recessed side region form a recessed perimeter around the slot.

11. The method of claim 1 , comprising:
prior to forming the slot, forming the masking layer on the back-side surface of the substrate; and
patterning the masking layer to create an exposed area of the back-side surface of the substrate sufficient to encompass the recessed regions and the length and width of the slot.

12. The method of claim 11 , wherein patterning the masking layer comprises patterning using a process selected from the group consisting of laser machining and dry etching.

13. The method of claim 11 , comprising:
after patterning the masking layer, removing substrate material from the back-side surface of the substrate to form a trench in the substrate having the length and width of the slot.

14. The method of claim 13 , comprising:
after forming the trench, wet etching the exposed area to remove additional substrate material from beyond both ends of the trench and from within the trench to form the recessed regions and the slot extending through to the front-side surface of the substrate.

15. The method of claim 13 , wherein removing the substrate material to form the trench comprises removing the substrate material using a process selected from the group consisting of laser machining and dry etching.

16. A method of forming a printhead comprising:
forming on a front-side surface of a substrate, a thin film layer and a fluidic channel and ejection chambers;
forming a masking layer on the back-side surface of the substrate;
forming a slot through the substrate from a back-side surface to the front-side surface, the back-side and front-side surfaces generally opposing one another, wherein the slot has a length extending along a long axis of the substrate and a width extending along a short axis of the substrate, sidewalls of a middle portion of the slot between the opposing front and back surfaces being perpendicular to the opposing front and back surfaces;
forming recessed regions into the back-side surface of the substrate at both longitudinal ends of the slot so that a longitudinal opening of the slot on the back-side of the substrate extends beyond the middle portion the slot interior to the substrate; and
forming a fang feature in a short axis sidewall of the slot, wherein the fang feature comprises two planar surfaces and is between the middle portion of the slot and the back-side surface of the substrate and extends laterally into the substrate beyond a sidewall of the middle portion of the slot.

17. The method of claim 16 , wherein the slot tapers from the middle portion to a narrower dimension at the front-side surface of the substrate.

18. The method of claim 16 , wherein the recessed regions each comprise at least two planar surfaces between the back-side surface of the substrate and the middle portion of the slot.

19. The method of claim 18 , wherein the recessed regions each comprise three planar surfaces between the back-side surface of the substrate and the middle portion of the slot.

20. The method of claim 18 , wherein the two planar surfaces of the recessed regions form a step between the back-side surface of the substrate and the middle portion of the slot.

Assignees

• Rivas Rio
• Friesen Ed
• Mcmahon Terry
• Schulte Donald W
• Hall David Douglas
• Hewlett Packard Development Co Lp

Inventors

• Rivas Rio
• Friesen Ed
• Mcmahon Terry
• Schulte Donald W
• Hall David Douglas

Classifications

• B41J2/1642

  thin film formation by CVD [chemical vapor deposition] · CPC title

• B41J2/1634

  laser machining · CPC title

• B41J2/1433

  Structure of nozzle plates · CPC title

• B41J2/1628

  dry etching · CPC title

• Y10T29/49401

  Fluid pattern dispersing device making, e.g., ink jet · CPC title