Abstract
An electrowetting display device includes an upper substrate, and a lower substrate including a first light-transmitting substrate, a conducting layer, a hydrophobic insulating layer and a pixel wall structure, wherein an upper surface of the pixel wall structure is provided with a support structure. A preparation method for the electrowetting display device, including providing an upper substrate and a lower substrate; preparing a pixel wall structure on the lower substrate; and preparing a support structure on the pixel wall structure.
Claims
1. An electrowetting display device, comprising an upper substrate and a lower substrate comprising a first light-transmitting substrate, a conducting layer, a hydrophobic insulating layer and a pixel wall structure, wherein an upper surface of the pixel wall structure is provided with a support structure.
2. The electrowetting display device according to claim 1, wherein the support structure comprises a plurality of support pillars.
3. The electrowetting display device according to claim 2, wherein the support pillars are arranged on junctions of mutually perpendicular walls in the pixel wall structure.
4. The electrowetting display device according to claim 2, wherein the support pillars are cylindrical or polygonal.
5. The electrowetting display device according to claim 1, wherein the support structure consists of a material of photoresist.
6. The electrowetting display device according to claim 1, wherein a material of the support structure consists of a material that is the same as the pixel wall structure.
7. The electrowetting display device according to claim 1, wherein a height of the support structure is less than or equal to a distance between the upper surface of the pixel wall structure and the upper substrate.
8. A preparation method for an electrowetting display device, comprising: providing an upper substrate and a lower substrate; forming a first light-transmitting substrate, a conducting layer and a hydrophobic insulating layer from the lower substrate; preparing a pixel wall structure on the lower substrate; and preparing a support structure on the pixel wall structure.
9. The preparation method for the electrowetting display device according to claim 8, wherein preparing the support structure on the pixel wall structure comprises preparing the support structure in a photoetching process.
10. The electrowetting display device according to claim 1, wherein a material of the support structure consists of a material with stronger hydrophilicity than the pixel wall structure.
11. A preparation method for an electrowetting display device, comprising: providing an upper substrate and a lower substrate; forming a first light-transmitting substrate, a conducting layer and a hydrophobic insulating layer from the lower substrate; preparing a pixel wall structure on the lower substrate; and preparing a plurality of support pillars on junctions of mutually perpendicular walls in the pixel wall structure.
12. The preparation method for the electrowetting display device according to claim 11, wherein preparing the support structure on the pixel wall structure comprises preparing the support structure in a photoetching process.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a sectional structure diagram of a general electrowetting display device.
[0021] FIG. 2 is a schematic diagram illustrating deformation of a substrate of the general electrowetting display device.
[0022] FIG. 3 is a schematic diagram illustrating a preparation process of a self-supported electrowetting display according to a first embodiment.
[0023] FIG. 4 is a three-dimensional structure diagram of a partial support structure according to a second embodiment.
[0024] FIG. 5 is a top view of the partial support structure according to the second embodiment.
DETAILED DESCRIPTION
First Embodiment
[0025] With reference to a preparation process shown in FIG. 3, a self-supported electrowetting display is prepared.
[0026] Firstly, as shown in FIG. 3a, a conducting layer 8 is prepared on a first light-transmitting substrate 9. A hydrophobic insulating layer 7 is prepared on the conducting layer 8. The hydrophobic insulating layer 7 can be a single layer structure or a composite layer structure of an insulating layer and a hydrophobic layer. In a preferred embodiment, the hydrophobic insulating layer 7 is a single layer structure, which is obtained by the following steps: coating a solution of the hydrophobic insulating layer 7 on a surface of the first light-transmitting substrate 9 having the conducting layer 8 via spin coating, scraping coating, slit coating, silk-screen printing, flexographic printing and other methods, performing thermal curing processing to obtain the hydrophobic insulating layer 7, and modifying a surface of the hydrophobic insulating layer 7 by a reactive ion etching machine to reduce a hydrophobicity of the surface. In the modification step, a photoresist material can be formed a film on the surface of the hydrophobic insulating layer 7 to increase an adhesive force on the surface of the hydrophobic insulating layer 7, and improve a wettability of the photoresist material on the surface. With reference to FIG. 3b, the photoresist material 6 is uniformly coated on the surface of the hydrophobic insulating layer 7 by a coating method such as spin coating, scraping coating, slit coating, etc. With reference to FIG. 3c, a first mask plate 13 is placed above and aligned with the lower substrate, and the first mask plate 13 is irradiated by parallel ultraviolet rays 15. The first mask plate 13 has a preset pattern of a pixel wall structure, and a part of the parallel ultraviolet rays can pass through the first mask plate 13 and irradiate on the photoresist material 6 to expose and cure the photoresist material 6. After the exposure, a second layer of photoresist material 12 is coated by any coating method such as spin coating, scraping coating, slit coating, etc. The second layer of photoresist material 12 is the same as the first layer of photoresist material 6. Then a second mask plate 14 is placed above and aligned with the lower substrate, and the second mask plate 14 is provided with a pattern of a supporting structure corresponding to a pixel wall position. The second mask plate 14 is irradiated by the parallel ultraviolet rays 15, and a part of the parallel ultraviolet rays can pass through the second mask plate 14 and irradiate on the photoresist material 12 to expose and cure the photoresist material 12. After the exposure, with reference to FIG. 3e, the pixel wall structure 6 and the support structure 12 are obtained by developing with a high concentration KOH solution. Because the patterns on the second mask plate 14 are all at the positions corresponding to the pixel wall 6, the exposure process of the support structure cannot affect a non-exposed area of the pixel wall 6, so that the support structure 12 is prepared on the pixel wall structure 6. The support structure 12 can include support pillars, and the support pillars can be of any shape, such as being cylindrical or polygonal. Then, the lower substrate is placed in a high-temperature environment to enable the hydrophobic insulating layer 7 to reach a glass transition temperature and restore the hydrophobicity of the surface of the hydrophobic insulating layer 7. Finally, a non-polar solution 5 is filled in the pixel grid under an environment of a polar electrolyte solution 4, and subsequently the upper substrate consisting of a second light-transmitting substrate 1, the conducting layer 2 and the sealant 3 is aligned and pressed with the lower substrate to complete the preparation process of the electrowetting device, thus obtaining the self-supported electrowetting display with the structure, as shown in FIG. 3f. A height of the support structure 12 is equal to a distance between the upper surface of the pixel wall structure 6 and the upper substrate, so that the support structure 12 is contacted with the conducting layer 2 to support the upper and lower substrates. The electrolyte solution 4 is still continuous in the self-supported electrowetting display, and the support structure 12 cannot affect the continuity of the electrolyte solution 4.
Second Embodiment
[0027] Refer to FIG. 4 and FIG. 5. FIG. 4 is a three-dimensional structure diagram of a partial support structure. FIG. 5 is a top view of the partial support structure. This embodiment is basically the same as the first embodiment, except that the support structure 12 is on a junction of mutually perpendicular walls in the pixel wall structure 6. The support structure 12 includes cylindrical support pillars. A material of the support structure 12 is a photoresist material with a stronger hydrophilicity than the pixel wall structure 6. The property of the material of the support structure 12 shall be similar to that of the material of the pixel wall structure 6. The material of the support structure 12 can be adjusted according to a requirement of a filling effect of the actual non-polar solution 5. The position and number of the support structures 12 can be controlled by a preset pattern of the second mask plate 14, so that densities and layouts of different support structures 12 can be designed for different sizes and different types of devices.
