Color filter and fabrication method thereof
View Patent ↗A color filter and a fabrication method thereof are provided. In the method, color filter ink that includes wax beads is ejected by an inkjet printing process. A black matrix defining R/G/B pixels is formed on a first surface of a substrate and transparent electrodes are formed on a second surface of the substrate opposite to the first surface at positions corresponding to the R/G/B pixels. The fabricated color filter ink is injected into an inkjet head, and the color filter ink is ejected from the inkjet head into each of the R/G/B pixels. A predetermined voltage is applied between the inkjet head and the transparent electrode such that the ejected color filter ink is precisely injected into each of the R/G/B pixels.
1. A method of fabricating a color filter, the method comprising:
forming a black matrix to define R/G/B pixels on a first surface of a substrate and forming transparent electrodes on a second surface of the substrate opposite to the first surface at positions corresponding to the R/G/B pixels;
ejecting a color filter ink including wax beads and carriers from an inkjet head into each of the R/G/B pixels;
applying a predetermined voltage between the inkjet head and the transparent electrode such that the ejected color filter ink is precisely injected into each of the R/G/B pixels such that the wax beads are positioned closer to the transparent substrate than the carriers; and
removing the transparent electrodes from the substrate.
2. The method of claim 1 , further comprising:
making a solid wax ink by mixing pigments, dispersants, wax, and monomers;
changing the solid wax ink into the wax beads;
uniformly mixing water or organic solvent with the wax beads to fabricate the color filter ink; and
injecting the color filter ink into the inkjet head.
3. The method of claim 2 , wherein the solid wax ink is changed into the wax beads by liquid electro polarization.
4. The method of claim 2 , further comprising:
electrifying the color filter ink including the wax beads before ejecting the color filter ink onto the substrate.
5. The method of claim 4 , wherein the applying of the predetermined voltage comprises:
applying a first voltage with the same polarity as the electrified color filter ink to the inkjet head; and
applying a second voltage with an opposite polarity as the electrified color filter ink to the transparent electrode.
6. The method of claim 1 , wherein the forming of the transparent electrodes comprises forming as many transparent electrodes as the R/G/B pixels formed on the substrate.
7. The method of claim 1 , further comprising:
after the applying of the predetermined voltage, baking and planarizing the color filter ink injected into each of the R/G/B pixels.