Electrowetting display device including a strengthened hydrophobic layer

1. A method of manufacturing an electrowetting display device, comprising:

forming a hydrophobic layer on a base substrate;

forming one or more pixel walls on the hydrophobic layer, wherein the one or more pixel walls at least partially enclose a pixel area and partition the pixel area from adjacent pixel areas, and wherein the hydrophobic layer has a substantially constant thickness over a central portion of the pixel area and a varying thickness over a peripheral portion of the pixel area adjacent to the pixel wall;

forming an electrowetting layer on the hydrophobic layer, the electrowetting layer including a first fluid and a second fluid, wherein the first fluid and the second fluid are immiscible with each other; and

forming at least a portion of an electronic device on the base substrate, wherein the electronic device is configured to apply an electric field to the electrowetting layer.

2. The method of claim 1 , wherein forming the hydrophobic layer comprises:

forming a first hydrophobic layer on the base substrate; and

reflowing the first hydrophobic layer at a temperature higher than a glass transition temperature of the first hydrophobic layer to form the hydrophobic layer, wherein the hydrophobic layer has a hydrophobicity greater than the hydrophobicity of the first hydrophobic layer.

3. The method of claim 1 , wherein the hydrophobic layer is a permeable parylene layer.

4. The method of claim 1 , wherein the electronic device comprises:

a switching device disposed on the base substrate;

a first electrode connected to the switching device; and

a second electrode spaced apart from the first electrode by at least the electrowetting layer.

5. A method of manufacturing an electrowetting display device, comprising:

forming an electrode on a substrate;

forming an electronic switching device on the substrate;

at least partially covering the electrode and the electronic switching device with an insulating layer;

forming at least one wall on the insulating layer to partition a pixel area;

forming a first hydrophobic layer on the at least one wall and the insulating layer, the first hydrophobic layer having a first hydrophobicity;

patterning the first hydrophobic layer to remove at least a portion of the first hydrophobic layer from a top of the at least one wall; and

reflowing the first hydrophobic layer at a reflow temperature to form a second hydrophobic layer, the second hydrophobic layer having a second hydrophobicity that is greater than the first hydrophobicity.

6. The method of claim 5 , wherein the reflowing is performed by heating the first hydrophobic layer to the reflow temperature in a range of about 160° C. to about 260° C.

7. The method of claim 5 , wherein the reflowing further comprises reflowing the first hydrophobic layer at the reflow temperature higher than a glass transition temperature of the first hydrophobic layer to enable creep to form an edge portion of the second hydrophobic layer, wherein a thickness of the edge portion of the second hydrophobic layer increases as a distance to the wall decreases.

8. The method of claim 5 , wherein forming the wall comprises:

patterning a photosensitive organic material that includes an epoxy compound by a photolithography process; and

curing the patterned photosensitive organic material by a baking process to form the wall.

9. The method of claim 5 , wherein a surface of the second hydrophobic layer comprises at least about 49 atomic percent (at %) of fluorine atoms.

10. The method of claim 5 , wherein patterning the first hydrophobic layer to remove the first hydrophobic layer from at least a top of the wall further comprises leaving portions of the first hydrophobic layer on sides of the wall.

11. A method of manufacturing an electrowetting display device, comprising:

forming a first hydrophobic layer having a first hydrophobicity on a base substrate;

forming a wall on the base substrate to partition a pixel area;

reflowing the first hydrophobic layer at a temperature higher than a glass transition temperature of the first hydrophobic layer to form a second hydrophobic layer having a second hydrophobicity greater than the first hydrophobicity; and

forming a fluid layer in the pixel area.

12. The method of claim 11 , wherein forming the wall comprises:

patterning a photosensitive organic material that includes an epoxy compound by a photolithography process; and

curing the patterned photosensitive organic material by a baking process to form the wall.

13. The method of claim 12 , wherein the second hydrophobic layer is disposed on the base substrate, and wherein the second hydrophobic layer comprises at least about 49 atomic percent (at %) of fluorine atoms in a surface thereof.

14. The method of claim 13 , wherein the second hydrophobic layer includes an amorphous fluorine compound comprising at least one of —CxFy-, CxFyHz-, —CxFyCzHp-, —CxFyO—, or—CxFyN(H)—, and wherein each of x, y, x, p is an integer number which is no less than 1.

15. The method of claim 11 , further comprising:

forming an opposite substrate facing the base substrate; and

forming an electronic device that controls the electrowetting layer, wherein a first portion of the electronic device is formed on the base substrate and a second portion of the electronic device is formed on the opposite substrate.

16. The method of claim 15 , wherein the first portion of the electronic device includes a switching device on the base substrate and a first electrode connected to the switching device.

17. The method of claim 15 , wherein the second portion of the electronic device includes a second electrode formed on the opposite substrate.

18. The method of claim 11 , wherein the forming of the first hydrophobic layer is performed prior to the forming of the wall.

19. The method of claim 18 , further comprising plasma-treating the first hydrophobic layer prior to the forming of the wall.

20. The method of claim 11 , wherein the forming of the first hydrophobic layer is performed between the forming of the wall and the forming of the electrowetting layer.