Patent ID: 6110625
Filing Date: 2000-08-29
Classification: G02B

Abstract:
A method for manufacturing color filters comprising the steps of:(a) coating a layer of positive photoresist onto a transparent electrically conductive substrate, and exposing the positive photoresist layer to form three or four regions of different initial levels of exposure energy, wherein the exposure energy of each region is D.sub.1, D.sub.2, D.sub.3 (and D.sub.4) progressively, D.sub.1 represents the full exposure energy of the positive photoresist, and D.sub.1 >D.sub.2 >D.sub.3 (>D.sub.4);(b) using a developer solution to develop and to remove the region of the photoresist layer with the exposure energy of D.sub.1 to thereby cause a corresponding area of the electrically conductive substrate underlying the photoresist to be uncovered, and electrodepositing said region with a color electrodeposition coating containing a low acid value anionic electrodeposition resin having an acid value of lower than 70 mg KOH/g so as to finish a pixel arrangement of a desired color;(c) exposing the entire surface of the substrate with an energy IE.sub.n to impart an incremental amount of energy to all regions of the substrate, wherein IE.sub.n is the energetic difference between D.sub.n and D.sub.n+1 and the definition of n is below:(i) when three regions of different initial levels of exposure energy are formed on the substrate, n is 1 and 2 progressively, or(ii) when four regions of different initial levels of exposure energy are formed on the substrate, n is 1, 2 and 3 progressively;(d) after each time of exposure in steps (c)(i) or (ii), using the same developer solution of step (b) to develop and to remove the photoresist of the region achieving full exposure to thereby cause the corresponding area of the electrically conductive substrate of underlying the photoresist to be uncovered, and then electrodeposition said region with a color electrodeposition coating containing an anionic electrodeposition resin having a low acid value to finish the pixel arrangements of other desired colors;(e) repeating steps (c) and (d) until all of the pixel arrangements are accomplished; and(f) forming an overcoat on the substrate.