Forming an electrowetting module having a hydrophilic grid

• US 7,763,314 B2
• Filed: 01/29/2008
• Issued: 07/27/2010
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dai, Steve, Li, Hao
• Primary Examiner(s): Gilliam; Barbara L
• Assistant Examiner(s): Jiang; Lisha
• Application Number:
  US12/021,404
• Publication Number:
  US 20090191334A1
• Time in Patent Office: 910 Days
• Field of Search: 427/162
• US Class Current: 427/164
• CPC Class Codes: G02B 26/005 based on electrowetting
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38

Abstract

A method of forming a matrix of electrowetting pixels includes forming a patterned layer of electrodes (512) on a substrate (510) and forming a patterned insulating layer (514) on the electrodes (512) and the substrate (510) to define a plurality of wells (516), each of the wells (516) aligned over one of the electrodes (512). A hydrophobic material (518) is formed on the bottom surfaces of the wells (516) and a hydrophilic material (526) is formed on sidewalls (519) of the wells (516), for example by one of selective reaction, selective deposition and selective etching, by the application of a beam (524) at an angle to impact the sidewalls (519) while substantially avoiding impacting the bottom surface (515). First and second liquids (532, 534) are disposed within the wells (516), the first liquid being not soluble in the second liquid.

Claims

1. A method of forming a matrix of electrowetting pixels, comprising:

patterning a base material defining a plurality of wells having a bottom surface and sidewalls;

forming a hydrophobic material on the bottom surface;

applying a beam upon the sidewalls at an angle to form a hydrophilic material on the sidewalls; and

disposing first and second fluids within the wells, the second fluid insoluble in the first fluid.

2. The method of claim 1 wherein the applying step comprises coating the hydrophobic material on the sidewalls, and converting the hydrophobic material on the sidewalls to a hydrophilic material.

3. The method of claim 2 wherein the applying a beam converts the hydrophobic material to a hydrophilic material by adding hydroxyl groups, and an injection of polar molecules capable of hydrogen bonding.

4. The method of claim 1 wherein the applying step comprises:

coating a hydrophobic material on the sidewalls; and

applying a reactive gas that forms a hydrophilic material on the hydrophobic material.

5. The method of claim 1 wherein the beam comprises one of an ion beam, a molecular beam, a laser beam, an ultra violet beam, and an x-ray beam.

6. The method of claim 1 wherein the first liquid comprises water and the second liquid comprises oil.

7. A method of forming a matrix of electrowetting pixels, comprising:

forming a patterned layer of electrodes on a substrate;

forming a patterned insulating material on the electrodes and the substrate to define a plurality of wells;

applying a beam to sidewalls of the wells to form a hydrophilic material on the sidewalls while forming a hydrophobic material on bottom surfaces of the wells; and

placing first and second liquids within the wells, the second liquid being insoluble in the first liquid.

8. The method of claim 7 wherein the applying step comprises coating a hydrophobic material on the surface of the insulating material, wherein the applying a beam converts the hydrophobic material on the sidewalls to a hydrophilic material.

9. The method of claim 8 wherein the applying a beam converts the hydrophobic material to a hydrophilic material by adding hydroxyl groups, and an injection of polar molecules capable of hydrogen bonding.

10. The method of claim 7 wherein the applying step comprises:

coating a hydrophobic material on the surface of the insulating material; and

applying a reactive gas that forms a hydrophilic material on the hydrophobic material.

11. The method of claim 7 wherein the beam comprises one of an ion beam, a molecular beam, a laser beam, an ultra violet beam, and an x-ray beam.

12. The method of claim 7 wherein the first liquid comprises water and the second liquid comprises oil.

13. A method of forming a matrix of electrowetting pixels, comprising:

forming a patterned layer of electrodes on a substrate;

forming a patterned insulating layer on the electrodes and the substrate to define a plurality of wells, each of the wells aligned over one of the electrodes;

forming a hydrophobic material on the bottom surfaces of the wells and a hydrophilic material on sidewalls of the wells by the application of a beam at an angle to impact the sidewalls while substantially avoiding impacting the bottom surface;

placing first and second liquids within the wells, the second liquid insoluble in the first liquid.

14. The method of claim 13 wherein the applying step comprises coating a hydrophobic material on the surface of the insulating material, wherein the applying a beam converts the hydrophobic material on the sidewalls to a hydrophilic material.

15. The method of claim 14 wherein the applying a beam converts the hydrophobic material to a hydrophilic material by adding hydroxyl groups, and an injection of polar molecules capable of hydrogen bonding.

16. The method of claim 13 wherein the applying step comprises:

coating a hydrophobic material on the surface of the insulating material; and

applying a reactive gas that forms a hydrophilic material on the hydrophobic material.

17. The method of claim 13 wherein the beam comprises one of an ion beam, a molecular beam, a laser beam, an ultra violet beam, and an x-ray beam.

18. The method of claim 13 wherein the first liquid comprises water and the second liquid comprises oil.