KR20000056622A - Methods for manufacturing color filters - Google Patents

Abstract

PURPOSE: A method for manufacturing a color filter is provided to use a color coating process a resin with low acid value so as to manufacture the color filter with improved characteristics. CONSTITUTION: A method for manufacturing a color filter includes following steps. At the first step, a positive photoresist layer is accumulated on a transparent electric conductive substrate. At the second step, a region on the electric conductive substrate at which covered by the photoresist layer is opened by using a developer agent. At the third step, the electric conductive substrate is exposed to a light at an energy of IE<SB POS="POST">n</SB>, where IE<SB POS="POST">n</SB> is an energy difference between D<SB POS="POST">n</SB> and D<SB POS="POST">n+1</SB>. At the forth step, the region at the second step is electrodeposited with a color accumulation coating including a negative ion electrodeposited resin. At the fifth step, the third and the forth steps are repeated until all pixels are arranged. At the sixth step, an overcoat is formed on the substrate.

Description

Manufacturing method of color filter {METHODS FOR MANUFACTURING COLOR FILTERS}

The present invention relates to a method for producing a color filter using a color electrical layer coating comprising an anionic electrical layer resin having a low acid value.

Flat panel displays (FPDs) are products of the optoelectronics industry, combining semiconductor, optical and coloring technologies. It is becoming increasingly recognized that FPDs are gradually replacing traditional cathode ray tubes (CRTs). Among many flat panel displays, liquid crystal displays (LCDs) are believed to occupy a leading position because of their light weight, thinness of thickness, and the possibility of becoming full-color displays. Color filters are a major factor in providing sparkle and vibrant images.

The color filter comprises three main components: the matrix of black tones, the color filter layer and the overcoat. At present, commercial methods of manufacturing color filters include (1) dyeing, (2) etching, (3) pigment dispersion, (4) electrical layers, and (5) printing.

Dyeing methods and etching methods preferentially use dyes as essential filtering materials. The advantages of using a dye as an essential filtering material are in various varieties, homogeneous chromaticity, high dyeability, high color intensity and high light transmission. Suitable dyes are disclosed in US Pat. Nos. 4,820,619 and 4,837,098. Because of the relatively inadequate light and heat resistance of the dyeing material, the dyeing and etching method has been largely replaced by the pigment dispersion method and the electrical layer method using the pigment as an essential filtering material. Pigments have great light and heat resistance. General pigment dispersion techniques that control the particle size of the pigment to 0.1 μm or less should simply be used, these two methods will allow the pigment to perform color strength and light transmission equal to or close to that of the dye. Due to the above points, the pigment dispersion method and the electric layer method have become the main methods that industry depends on the production of color filters.

Pigment dispersion methods such as those disclosed in US Pat. Nos. 5,085,973 and 4,786,148 and Japanese Patent Laid-Open No. 60-129739 provide the use of photolithographic techniques that are well dispersed in pigments and photolithography techniques that achieve high resolution and pattern design flexibility. Include. This method is currently a major manufacturing technique. However, (1) the efficacy of the materials is low (1% to 2%), (2) the tendency to apply to large sizes corresponding to glass substrates, and (3) the opportunity to use expensive, precisely aligned machines is very frequent. Due to the fact, the production cost for such a method does not coincide with the trend of larger size and lower price of color liquid crystal displays.

Electrolayer coating processes, such as those disclosed in US Pat. No. 4,812,387, use electrophoretic techniques to electrolayer electrolayer resins and pigments well dispersed in water onto a patterned transparent electrode substrate. A filter layer of uniform thickness and good smoothness is obtained. Electrical layer coating technology is limited in its application. Because of the design of the electrode, the electrical layer coating process can only use a substrate with a strip pattern of conductive film for implementation. So, it is impossible to align the pixels freely.

Of all the manufacturing processes of color filters, the printing process is the least expensive process. However, it has problems of poor order precision, smoothness and reliability. Printing processes are not well accepted by the industry of manufacturing high quality electrical products and are generally used for the manufacture of low-end products.

In order to address the above problems and at the same time preserve the advantages of pigment dispersion and electrical layer coating process, Nippon Oil Company has combined electro layer (ED) coating methods and lithography techniques to produce electrolayer lithography for color filters. A method was proposed. As disclosed in US Pat. Nos. 5,214,541 and 5,214,542, the contents of which are incorporated herein by reference, Nippon Oil Company first discloses an electrolayer lithography method. The method comprises exposing the photoresist on a transparent electrically conductive layer at a time under a photomask having a pattern of three or more different degrees of light transmission to form regions of different levels of exposure energy, step by step to remove the photoresist. Using other developer solutions, and gradually layering red, green, and blue on the exposed electrically conductive substrate. The electrolayer lithography method discussed above has several advantages.

(1) The method combines an electrical layer and a lithography technique. Therefore, a higher precision pattern can be obtained that is better than can be obtained from the electrical layer coating method.

(2) The shape of the pattern has a high degree of freedom and can provide both strip and non-strip patterns. And,

(3) Because it exploits the beneficial properties of the electrical layer process, the coated film exhibits a uniform film thickness and good smoothness.

However, the electrolayer lithography method has at least three different levels of concentration to selectively remove the photoresist exposed at different stages of the development process and to electro-layer red, green and blue (R, G, B) thereon. Since it requires a developer of, it allows only a relatively narrow process window, which allows tolerance. Furthermore, it is known to use a base aqueous developer for positive photoresist. Under such circumstances, only very limited choices exist in selecting an appropriate electrical layer resin. In addition, there is still photoresist on the substrate before the electrical layer of all required colors is completed. Thus, the curing process at elevated temperature is not possible. In the examples of this reference, a color electrical layer coating comprising an anionic electrical layer resin is used. The acid value of the resin is in the range of 100 to 500 mg KOH / g. That type of anionic electrical layer resin is easily affected by the developer. Therefore, a higher concentration of developer cannot be applied. This causes a narrow tolerance of the developer. Although cationic electrical layer resins have better base resistance, they show a disadvantage of easily yellowing and low permeability. During the electrical layer process, such types of resins tend to reduce indium tin oxide (ITO), which is commonly used as the transparent electrically conductive material of transparent electrically conductive substrates, to become black spots. The technical limitations described above are considered to be a major reason for the lack of commercialized products produced from the process.

Another method of manufacturing a color filter combining an electrical layer coating method and a lithography technique is disclosed in US Pat. No. 5,641,595. The contents of this patent are incorporated herein by reference. The method is characterized by utilizing the energy accumulation characteristics of the positive photoresist in combination with the photo-curable electrical layer resin. The process includes coating the positive photoresist layer onto a transparent electrically conductive substrate and exposing the positive photoresist layer to form regions of other initial levels of exposure energy. One of the regions amounts to the full exposure energy of the positive photoresist. After the developing step, the photoresist on this area is removed and the corresponding electrically conductive substrate is not covered. The area is then electrically layered to form the required colors. When all the steps of the method are performed, the substrate requires an exposure step without alignment. Then, the previously layered pixels are cured by light. This step can avoid the electrically layered collar being attacked by the developer used in the next step. Areas in which a sufficient amount of energy is not accumulated require the next exposure to ensure that the energy of the second area reaches the full exposure energy of the positive resist. Each area is then developed with a developer and electrically layered with the desired color. The above steps are repeated until the alignment of all the pixels is completed.

This energy increasing process has the function of gradually developing regions of different levels of exposure energy. Because the method combines the advantages of using a photocurable anion electrolayered resin, making the exposure energy such that each region reaches the complete exposure energy of the positive resist, and curing the film formed by the electrical layer coating. Therefore, the influence of the basic developer used continuously on the electrically layered pixels is eliminated and the developing step is simplified. However, photocurable electrolayered resins require a sufficient amount of exposure energy to cure the electrolayered coating to defend against developer attack. In order to have a filtering function, the pigment particles are dispersed in an electrolayered coating. Thus, the energy required to expose the coating is greater. This narrows the exposure tolerance of the photoresist. Furthermore, adding a group of photosensitizers to an electrically layered coating increases the difficulty of achieving good dispersibility and stability and adversely affects the yield of the product.

The present invention seeks to overcome the above problems and preserve the advantages of pigment dispersion and electrical layer coating processes for the production of color filters. The present invention develops excellent manufacturing techniques for color filters by using a color electrical layer coating comprising an anionic electrical layer resin having a low acid value, combined with a positive resist that is about base developed. Because the present invention uses a low acid value anionic electrical layer resin, combined with a weak base developed positive resist solution, the pixels of the corresponding regions previously layered are not affected by the function of the photoresist without affecting the function of the photoresist. It may be baked at normal drying temperatures to defend against the attack of the developer, which is subsequently used to develop other colors of interest. The method of the present invention shows the advantages of having a high degree of freedom and a wide process window in pattern shape. Furthermore, the production of large surface color filters and the complete yield of products are possible.

1A is a schematic diagram showing the various stages of one manufacturing process of a color filter according to the present invention with transparent electrically conductive substrates arranged in a matrix of black tint.

1B is a schematic diagram showing the various steps of another manufacturing process of the color filter according to the invention, wherein the transparent electrically conductive substrate is arranged in a matrix of black tint.

Figure 2 is a schematic diagram showing the different stages of another manufacturing process of the color filter according to the invention, wherein the transparent electrically conductive substrate is not arranged in a matrix of black tint.

The present invention relates to a method for producing a color filter using a color electrical layer coating comprising an anionic electrical layer resin having a low acid value. The method includes coating a positive resist layer onto a transparent electrically conductive substrate, exposing the substrate under a photomask or photomasks to form regions of different initial levels of exposure energy, the photo on each corresponding region. Exposing the entire surface of the substrate in an energy-increasing manner that gradually permits all regions of the substrate to achieve sufficient energy to fully expose the resist, the same developer such that the electrically conductive substrate in that region is not covered. Developing each region step by step, electrically layering the region with a color electrical layer coating comprising an anionic electrical layer resin having a low acid value to finish pixel alignment of the desired colors and completely exposing the substrate. It includes. The low acid value anion electrical layer resin used in the present invention has an acid value of 70 mg KOH / g or less.

The method of the present invention shows the advantages of having a high degree of freedom and a wide process window in pattern shape. Furthermore, the production of large surface color filters and the complete yield of products are possible.

The present invention relates to a method of manufacturing a color filter comprising the following steps.

(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 each region of The exposure energy is progressively D ₁ , D ₂ , D ₃ (and D ₄ ), where D ₁ represents the complete exposure energy of the positive resist and is D ₁ > D ₂ > D ₃ (> D ₄ );

(b) the pixel alignment of the required color so that the corresponding area of the electrically conductive substrate underlying the photoresist is not covered with a developer in order to develop and remove the area of the photoresist layer having the exposure energy of D ₁ . Electrical layering the region with a color electrical layer coating comprising an anionic electrical layer resin having an acid value of 70 mg KOH / g or less to complete the step;

(c) exposing the entire surface of the substrate with an energy IE _n delivering an increment of energy to all regions of the substrate, where IE _n is the energy difference between D _n and D _{n + 1} , wherein The definition is as follows:

(i) when three regions of different initial levels of exposure energy are formed on the substrate, n is progressively 1 and 2, or

(ii) when four regions of different initial levels of exposure energy are formed on the substrate, n is progressively 1, 2 and 3;

(d) after each time of exposure in step (c) (i) or (ii), using the same developer as used in step (b) to develop and remove the photoresist in the area where complete exposure has been achieved; After the corresponding area of the electrically conductive substrate underlying the photoresist is uncovered, the area is then covered with a color lamination coating comprising an anionic electrical layer resin having a low acid value to complete pixel alignment of the other colors required. Electrically layering;

(e) repeating steps (c) and (d) until all pixel alignments are completed;

(f) forming an overcoat on the substrate.

The transparent electrically conductive substrate of the present invention may be an electrically conductive glass selected or commercialized from the group consisting of oxides of tin, indium and antimony and mixtures thereof, such as indium tin oxide (ITO).

The material forming the matrix of black tint may be an oxide or alloy such as chromium, nickel, or a mixture thereof. Alternatively, a matrix of black tint may be formed from an organic polymeric coating composition comprising black pigment dispersed therein. For example, the material may be electrically conductive or non-electrically conductive, such as acrylate resins and epoxy resins.

The positive photoresist (PR) used in the present invention may be selected from the group consisting of novolak resins and naphthyoquinone diazide compounds and derivatives thereof. Suitable positive photoresists are those disclosed in US Pat. No. 5,645,970. The energy-accumulable quality of such materials allows the areas of other initial exposure energy to be developed gradually. Since the positive resist acts on the principle that its solubility increases after exposure to light energy, it can be developed by the basic solution. The precision of the pattern of the photoresist is reliable and the size accuracy is perfect. Preferably, the photoresist for use in the process of the invention should have high contrast to minimize film loss in unexposed or less exposed areas.

The technique for coating the photoresist may be anything conventionally known to those skilled in the art, such as spraying, dip coating, screen printing, roll coating, spin coating. Preferably, the photoresist layer has a thickness of 1 to 10 μm, more preferably 1.5 to 5 μm.

If the photoresist layer forms three regions of different exposure energies after exposure, the exposure energies D ₁ , D _2, and D ₃ in each region may be from 100% to 40%, from 85% to 20%, 70 % To 0%. Preferably, each of D ₁ , D ₂ and D ₃ represents from 100% to 70%, from 70% to 40%, from 40% to 0%, respectively. If the photoresist layer forms four regions of different levels of exposure energy after exposure, the exposure energies D ₁ , D ₂ , D ₃ and D ₄ of each region are from 100% to 40%, respectively, from 85% to 20% Up to 70% to 5% and 50% to 0%. Preferably, each of D ₁ , D ₂ and D ₃ and D ₄ represents 100% to 80%, 80% to 50%, 50% to 30%, 30% to 0%, respectively.

The energy of complete exposure required in photoresist fabrication is between 80 and 1500 mJ / cm ² . It can be done through a single exposure step using a photomask with multiple exposure densities. Alternatively, it can be performed using a photomask having a predetermined exposure pattern. By careful movement of the photomask, regions of different levels of exposure energy may be formed on the photoresist. Another alternative method uses a plurality of (three or four) photomasks to form the required three regions of different degrees of initial exposure energy that can be developed continuously using the incremental exposure methods disclosed herein. It is. The pattern of that region may be a strip or non-strip free arrangement (such as mosaic or triangle).

Positive photoresists are typically developed by basic developer solutions such as aqueous solutions of sodium carbonate, sodium hydrogen carbonate, sodium metasilicate, tetraalkyl ammonium hydroxide, sodium hydroxide, potassium hydroxide, and mixtures thereof. Preferred concentrations of the developer range from 0.2 to 4% by weight. The developing temperature is generally 10 to 70 ° C, preferably 15 to 40 ° C. The time required for the developing step is typically 5 to 600 seconds.

Coloring agents consisting of crosslinkable curing agents, organic solvents, neutralizing agents and dyes, pigments or mixtures thereof may be added into the color electrical layer coating comprising the low acid value anionic electrical layer resin used in the present invention.

The low acid value anion electrically layer resin used in the present invention is preferably a polyester having a carboxyl group. The resin can be dissolved or dispersed in a neutralizing agent. Preferably, the resin has an acid value of 70 mg KOH / g or less, preferably 20 to 70 mg KOH / g, and has a solid content of about 75%. Monomers constituting the polyester include those selected from the group consisting of neopentyl glycol, adipic acid, isophthalic acid, isodecanol, trimellitic anhydride, butyl cellosolve and 2-butanol Can be.

The neutralizing agent may be selected from the group consisting of dimethyl ethanolamine, diethyl ethanolamine, diisopropanolamine, triethylamine and mixtures thereof. Crosslinkable curing agents suitable for use in the present invention may be selected from the group consisting of methylated melamine resins, butylated melamine resins, methylated methanol melamine resins, butylated methanol melamine resins, benzoguanamine resins.

Colorants of the invention may be dyes, pigments or mixtures thereof. Typically, suitable dyes may be selected from azo dyes, anthraquinone dyes, benzodifuranone dyes, condensed methine dyes, and mixtures thereof. The pigments include azo lake organic pigments, quinineacridone organic pigments, phthalocyanine organic pigments, isoindolinone organic pigments, anthraquinone organic pigments, thioindigo organic pigments, chrome yellow, chromium blue, iron oxides, chromium It may be selected from the group consisting of vermilion, chrome green, ultramarine, prussian blue, cobalt green, emerald green, titanium white, carbon black, and mixtures thereof.

According to the process of the present invention, when three regions of different degrees of exposure energy are formed on a substrate, the substrate is prearranged in a matrix of black hue, and with a color electrical layer coating comprising red, green and blue. Either selectively or gradually coated. When four regions of different degrees of exposure energy are formed on the substrate, after the color electrical layer coating comprising red, green, and blue is selectively or gradually electrically layered, the black resin is the last region (fourth region). ) To the electrical layer. The developing and complete exposure steps can be repeated until the pixel alignment is all complete. When the pixel alignment is all completed according to the present invention, the substrate is well baked so that the electrical layer resin is fully cured.

Anionic electrical layer resins exhibit good storage stability (nature that does not turn yellow), emulsification stability and pigment dispersibility (particularly pigment dispersibility at high concentrations). When the anionic electrical layer resin is combined with the photoresist, there is still photoresist on the substrate before the electrical layer of all required colors is completed. There is no way to induce a thermal-curing process at elevated temperatures. With respect to the anionic electrical layer resin, there is still a possibility of being attacked by the developer used continuously.

In order to avoid such drawbacks, the present invention employs a color electrical layer coating comprising an anionic electrical layer resin having an acid value of 70 mg KOH / g or less, in combination with a positive base developed positive photoresist solution. The method of the present invention uses an energy increment method and develops the photoresist stepwise with one single concentration of developer. After the corresponding area of the electrically conductive substrate is not covered, the area is electrically layered in color to align the pixels. In summary, the present invention is characterized by the use of an electrical layer coating comprising an anionic electrical layer resin having an acid value of 70 mg KOH / g or less, in combination with positive photoresist technology possessing an energy incremental function. For example, a weak base developed positive photoresist solution disclosed in US Pat. No. 5,645,970 can be used. Therefore, the pixels of the corresponding areas that were previously layered usually have a normal, such as 80-120 ° C. to protect against attack of the developer that is subsequently used to develop the desired other color of the pixels without affecting the function of the photoresist. It can be baked at a drying temperature.

The method of the present invention shows the advantage of having a high degree of freedom and a wide process window in pattern shape. Furthermore, the production and complete yield of large surface color filters is possible.

1A and 1B each represent a preferred embodiment according to the present invention. Both embodiments relate to a method of making a color filter in which a transparent electrically conductive substrate is arranged in a matrix of black tint. The method includes the following steps:

1. preforming a matrix of black tint on the transparent electrically conductive substrate 2; The black hue matrix can be made from conductive or non-conductive material, as shown in (3) of FIG. 1A (a) and (13) of FIG. 1B (a);

2. As shown in FIGS. 1A (a) and 1B (a), a positive photoresist layer is coated onto the transparent electrically conductive substrate 2 and the photo is formed to form three regions of different initial levels of exposure energy. Exposing the photoresist layer under a mask or photomask, wherein the exposure energy of each region is D ₁ (5), D ₂ (6), and D ₃ (7), respectively, where D ₁ is the complete of the positive resist; Exposure energy is D ₁ > D ₂ > D ₃ ;

3. As shown in FIGS. 1A (B) and 1B (B), an electrically conductive substrate placed underneath the photoresist using a developer to develop and remove regions of the photoresist layer with exposure energy D ₁ (5). Performing an electrical layer arrangement of the first pixel 8 such that the corresponding region of is not covered and the layer is electrically layered with a color electrical layer coating comprising an anionic electrical layer resin having a low acid value;

4. Exposing the entire surface of the substrate with energy IE ₁ to deliver an increment of energy to all regions of the substrate, as shown in FIGS. 1A (b) and 1B (b), where IE ₁ is D Energy difference between ₁ and D ₂ , wherein the exposure energy in the region where the initial exposure energy is D ₂ is accumulated at the full exposure amount (D ₂ + IE ₁ = D ₁ ) (6 ′), and the initial exposure energy is D _3. The exposure energy of the phosphorus region is not accumulated at the full exposure amount (only D ₃ + IE ₁ ) 7 ';

5. As shown in FIGS. 1A (c) / (d) and 1B (c) / (d), the same as in step 3 for developing and removing the photoresist in the area where full exposure 6 'has been achieved. Using a developer to cover the corresponding area of the electrically conductive substrate underlying the photoresist, and electrically layering the area with a color electrical layer coating comprising an anionic electrical layer resin having a low acid value, ie, a second pixel. Performing the electrical layer arrangement of (9, 19);

6. Exposing the entire surface of the substrate with energy IE ₂ to deliver an increment of energy to all regions of the substrate, as shown in FIGS. 1A (b) and 1B (b), where IE ₂ is D _{It is} the energy difference between ₂ and D ₃ , where the exposure energy of the region where the initial exposure energy is D ₃ (7) is accumulated in the total exposure amount (D ₂ + IE ₁ + IE ₂ = D ₁ ) (7 '') ;

7. As shown in FIGS. 1A (e) and 1B (e), the lower portion of the photoresist using a developer as in step 3 to develop and remove the photoresist in the area that achieved full exposure (7 &quot;). Performing an electrical layer arrangement of the third pixel (10, 20) such that the corresponding area of the electrically conductive substrate placed on the surface is not covered;

8. Finally, forming an overcoat on the substrate, as shown in FIGS. 1A (f) and 1B (f).

2 is a schematic diagram showing the various steps of another process for producing a color filter according to the invention, wherein the transparent electrically conductive substrate is not arranged in a matrix of black tint. The method includes the following steps:

1. As shown in FIGS. 1A (a) and 1B (a), a positive photoresist layer is coated onto a transparent electrically conductive substrate 2 and the photo is formed to form four regions of different initial levels of exposure energy. Exposing the photoresist layer under a mask or photomask, wherein the exposure energy of each region is D ₁ (22), D ₂ (23), D ₃ (24) and D ₄ (25), respectively, D ₁ is shows a complete exposure energy of the positive _{resist, D 1> D 2> D} 3> D 4;

2. As shown in FIG. 2A (b), the corresponding area of the electrically conductive substrate underlying the photoresist is covered using a developer to develop and remove the area of the photoresist layer with exposure energy D ₁ (22). And electrically layering the region with a color electrical layer coating comprising an anionic electrical layer resin having a low acid value, ie, performing an electrical layer arrangement of the first pixel 26;

3. Exposing the entire surface of the substrate with energy IE ₁ to transfer an increment of energy to all regions of the substrate, as shown in FIG. 2A (b), where IE ₁ is the energy between D ₁ and D ₂ . In this case, the exposure energy of the region where the initial exposure energy is D ₂ (23) is accumulated in the total exposure amount (D ₂ + IE ₁ = D ₁ ) (23 '), and the initial exposure energy is D ₃ (24), respectively. ) And D ₄ (25) do not accumulate exposure energy in full exposure (only (D ₃ + IE ₁ ) 24 ′ and (D ₄ + IE ₁ ) 25 ′);

4. As shown in FIGS. 2A (c) / (d), an electroplating underlying the photoresist using a developer such as that of step 3 to develop and remove the photoresist in the area that achieved full exposure 23 '. The corresponding region of the conductive substrate is not covered, and the layer is electrically layered with a color electrical layer coating including an anionic electrical layer resin having a low acid value, that is, performing an electrical layer arrangement of the second pixel 27. step;

5. Exposing the entire surface of the substrate with energy IE ₂ to deliver an increment of energy to all regions of the substrate, as shown in FIGS. 1A (b) and 1B (b), where IE ₂ is D _Is the energy difference between ₂ and D ₃ , where the exposure energy of the region where the initial exposure energy is D ₃ (23) is accumulated to the full exposure amount (D ₃ + IE ₁ + IE ₂ = D ₁ ) (24 '') The exposure energy of the region where the initial exposure energy is D ₄ (25) is not accumulated in the full exposure amount (only D ₄ + IE ₁ + IE ₂ ) 25 ″;

6. As shown in FIGS. 2A (c) / (d), an electroplating underlying the photoresist using a developer such as that of step 3 to develop and remove the photoresist in the area that achieved full exposure 24 ". Performing an electrical layer arrangement of the third pixel 28 such that the corresponding area of the conductive substrate is not covered;

7. As shown in FIG. 2 (e), exposing the entire surface of the substrate with energy IE ₃ to deliver an increment of energy to all regions of the substrate, where IE ₃ is the energy between D ₃ and D ₄ . Difference, wherein the exposure energy of the region where the initial exposure energy is D ₄ (25) is accumulated to the full exposure amount (D ₃ + IE ₁ + IE ₂ + IE ₃ = D ₁ ) (25 ''), and then full Using a developer, such as step 3, to develop and remove the photoresist in the area at which exposure 25 " has been achieved, so that the corresponding area of the electrically conductive substrate underlying the photoresist is not covered, and the black resin Coating the area with a layer of and curing the matrix of black tint 29 filled in the holes in the area under the shielding effect provided by the cured resins 26, 27, 28. Back of conductive substrate Irradiating UV light with the kinds of materials forming the matrix of the black tint and a method of producing the same include: (1) employing a heat-curable positive photoresist dispersed with a black colorant and Using a region having a low initial exposure energy to form a matrix of tones, (2) employing a black electrical layer resin of the same type as included in the electrical layer coating and arranging the black electrical layer resin on the electrically conductive substrate Using an electrical layer method, (3) employing a photosensitive black electrical layer resin and baking the substrate to cure the pixels 26, 27, 28 at elevated temperature and completely blackening the matrix 29 of the black tint. Baking;

8. Finally, forming an overcoat on the substrate, as shown in FIGS. 1A (f) and 2 (f).

Embodiments of the invention are described below. It is believed that other objects, features and advantages of the present invention can be more clearly understood through the description of the following examples.

Example

Example 1 Synthesis of Polyester Resin Having Low Acid Value

Commonly known polyesterifications are used to carry out the synthesis of low acid value polyesters. The types and amounts of monomers and solvents used are as follows:

Ingredient amount, weight percent

Neopentyl Glycol 24.53

Adipic acid 3.25

Isophthalic acid 7.95

Isodecanol 14.40

Trimellitic anhydride 25.81

Butyl cellosolve 5.00

2-butanol 20.00

The chemicals indicated above are placed in the reactor. The mixture is stirred under nitrogen atmosphere at elevated temperature to carry out the reaction. After esterification and dehydration under reduced pressure, the polymerisation reaction ends. The analysis results of the obtained resin solution are as follows:

Non-volatile components (150 ° C. 1 hour. Wt%) 75.4

Low acid value (mg KOH / g, solid) 48.7

Viscosity (25 ° C, cps) 45.2

Example 2 Preparation of an Electrical Layer Coating Comprising a Polyester Resin Having a Low Acid Value

The types and amounts of components of the low acid value polyester resin are as follows:

ingredient A-1 A-2 A-3 Anionic polyester resin 95.0 95.0 95.0 Melamine resin (Nikarakku MX-40) 8.0 8.0 8.0 2-ethoxy ethanol butyl ether 25.0 25.0 25.0 2-ethoxy ethanol ethyl ether 5.0 5.0 5.0 Neobutanol 18.0 18.0 18.0 Triethylamine 2.5 2.5 2.5 Deionized water 813.5 813.5 813.5 Phthalocyanine Blue (SR-1500) 5.0 - - Phthalocyanine Green (SAX) - 5.0 - Azo Lake Pigment (CARMINE FB) - - 5.0 Sum 1000 1000 1000

The following steps are used to prepare an electrical layer coating comprising a polyester resin having a low acid value:

1) In the amounts described above, anionic polyester resins, melamine resins (Nikarakku MX-40), 2-ethoxy ethanol butyl ether, 2-ethoxy ethanol ethyl ether, neobutanol and triethylamine. Place the reagents in a container and mix them under stirring;

2) Weigh the pigments, in the amounts described above, add them to the mixture and mix under stirring;

3) Milling disperse the mixture with a mill. The milling beads used had an average particle size of 0.8 to 1.2 μm;

4) deionized water is added under stirring and the mixture is emulsified; And

5) Filter the mixture with a 5 μm filter.

Example 3

A 2.2 μm thick positive photoresist corresponding to a weak base developer as disclosed in US Pat. No. 5,645,970 was formed on an electrically conductive transparent glass substrate comprising a matrix of black hue, measured at 0.7 mm in thickness and prearranged. Photomasks with only one-third light-transmissive zones produce exposure energies of 250, 150 and 50 mJ / cm ² (100%, 60% and 20%), respectively, to form three areas of different initial exposure energy. Carefully used by motion to guide.

A developer comprising 0.5% Na ₂ SiO ₃ was used to develop and remove the 250 mJ / cm ² initial exposure area (eg 100% initial exposure energy). Therefore, the photo-curable resin comprising the red pigment was electrically layered onto the exposed surface of the conductive substrate. The electrical layer process was performed for 20 seconds at an electrical voltage of 50 V, 25 ° C. After the electrical layer process was completed, the substrate was washed with deionized water and dried at 90 ° C. for 10 seconds. The entire photoresist was then exposed to a light source to receive 100 mJ / cm ² exposure energy increments. This means that the cumulative exposure energy in the second region (150 mJ / cm ² , or 60% initial exposure energy) and the third region (initially 50 mJ / cm ² , or 20% initial exposure energy) is 250 mJ / It was allowed to rise to cm ² (complete exposure) and 150 mJ / cm ² (60% of complete exposure). Then, similarly, the same developer containing 0.5% Na ₂ SiO ₃ was used to develop and remove the complete exposure area. This was followed by an electrical layer of a photo-curable resin comprising a green pigment onto the exposed surface of the conductive substrate under the same conditions and dried. Again, the entire photoresist was exposed to the light source to receive another 100 mJ / cm ² exposure energy increment. This caused the cumulative exposure energy in the third region to rise to 250 mJ / cm ² (100% exposure). The area was developed and removed using the same developer comprising 0.5% Na ₂ SiO ₃ . Next to this, again, an electrical layer of a photocurable resin comprising a blue pigment was performed on the exposed surface of the conductive substrate under the same conditions. Finally, the entire photoresist was exposed to receive another 100 mJ / cm ² exposure energy so that the blue resin cured. To ensure complete curing of all colored layers, the photoresist was heated at 260 ° C. for 1 hour. The array of three pixels, red, green and blue is complete.

The foregoing description of the preferred embodiment of the present invention has been provided for purposes of illustration and illustration. Obvious modifications or variations are possible in light of the above teaching. The above embodiments are selected and described to provide the most preferred illustration of the principles of the present invention and its practical application, and thus various embodiments as suitable for the particular use contemplated by those skilled in the art. Various modifications make it possible to use the present invention. All such modifications and variations are within the scope of the present invention as determined by the claims when interpreted in accordance with the just, legally and fairly qualified scope of the appended claims.

The method of the present invention, which is a method of manufacturing a color filter using a color electrical layer coating comprising an anionic electrical layer resin having a low acid value, shows the advantages of having a high degree of freedom and a wide process window in pattern shape. Furthermore, the production of large surface color filters and the complete yield of products are possible.

Claims (18)

In the manufacturing method of the color filter, (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 Where the exposure energy of each region is progressively D ₁ , D ₂ , D ₃ (and D ₄ ), where D ₁ represents the complete exposure energy of the positive resist, and D ₁ 〉 D ₂ 〉 D ₃ (〉 D ₄ ) Im-; (b) the pixel alignment of the required color so that the corresponding area of the electrically conductive substrate underlying the photoresist is not covered with a developer in order to develop and remove the area of the photoresist layer having the exposure energy of D ₁ . Electrical layering the region with a color electrical layer coating comprising an anionic electrical layer resin having an acid value of 70 mg KOH / g or less to complete the step; (c) exposing the entire surface of the substrate with an energy IE _n delivering an increment of energy to all regions of the substrate, where IE _n is the energy difference between D _n and D _{n + 1} , wherein The definition is as follows: (i) when three regions of different initial levels of exposure energy are formed on the substrate, n is progressively 1 and 2, or (ii) when four regions of different initial levels of exposure energy are formed on the substrate, n is progressively 1, 2 and 3; (d) after each time of exposure in step (c) (i) or (ii), using the same developer as used in step (b) to develop and remove the photoresist in the area that achieved complete exposure; After the corresponding area of the electrically conductive substrate underlying the photoresist is uncovered, the area is then electrically coated with a color lamination coating comprising an anionic electrical layer resin having a low acid value to complete the pixel alignment of the other colors required. Laminating; (e) repeating steps (c) and (d) until all pixel alignments are completed; (f) forming an overcoat on the substrate Method for producing a color filter comprising a. The method of claim 1, The low acid value anion electrical layer resin is a polyester resin having a carboxyl group. Method for producing a color filter. The method of claim 1, The anionic electrical layer resin has a low acid value of 20 to 70 mg KOH / g Method for producing a color filter. The method of claim 1, The anionic electrical layer resin further comprises a colorant composed of a crosslinkable curing agent, an organic solvent, a neutralizing agent or a dye, a pigment, or a mixture thereof. Method for producing a color filter. The method of claim 4, wherein The crosslinking curing agent is selected from the group consisting of methylation melamine resin, butylated melamine resin, methylated methanol melamine resin, butylated methanol melamine resin, benzoguanamine resin and mixtures thereof. Method for producing a color filter. The method of claim 4, wherein The pigments include azo lake organic pigments, quinacridone organic pigments, phthalocyanine organic pigments, isoindolinone organic pigments, anthraquinone organic pigments, thioindigo organic pigments, chrome yellow, chromium blue, iron oxide Selected from the group consisting of chrome vermilion, chrome green, ultramarine, prussian blue, cobalt green, emerald green, titanium white, carbon black and mixtures thereof Method for producing a color filter. The method of claim 4, wherein The dye is selected from the group consisting of azo dyes, anthraquinone dyes, benzodifuranone dyes, condensed methine dyes, and mixtures thereof. Method for producing a color filter. The method of claim 1, When three regions of different initial levels of exposure energy are formed on the substrate, D ₁ , D ₂ and D ₃ are respectively 100% to 40%, 85% to 20%, 70% to 0% representative Method for producing a color filter. The method of claim 8, D ₁ , D _2, and D ₃ represent 100% to 70%, 70% to 40%, and 40% to 0%, respectively. Method for producing a color filter. The method of claim 1, When four regions of different initial levels of exposure energy are formed on the substrate, D ₁ , D ₂ , D ₃ and D ₄ are respectively from 100% to 40%, from 85% to 20%, from 70% to 5 %, Representing 50% to 0% Method for producing a color filter. The method of claim 10, When four regions of different initial levels of exposure energy are formed on the substrate, D ₁ , D ₂ and D ₃ and D ₄ are respectively from 100% to 80%, from 80% to 50%, from 50% to 30 %, Representing 30% to 0% Method for producing a color filter. The method of claim 1, Step (a) comprises a single exposure step using a photomask having multiple exposure densities; Or a single exposure step using the photomask having a predetermined exposure pattern by carefully moving the photomask to form regions of different degrees of exposure energy on the photoresist of the substrate; Or a single exposure step using a plurality of photomasks to form the required three regions of different degrees of initial exposure energy forming regions of different degrees of exposure energy on the photoresist of the substrate. Method for producing a color filter. The method of claim 1, The developer of step (c) is selected from the group consisting of sodium carbonate, sodium hydrogen carbonate, sodium metasilicate, tetraalkyl ammonium hydroxide, sodium hydroxide, potassium hydroxide, and mixtures thereof Method for producing a color filter. The method of claim 1, In step (e) the substrate is optionally or gradually coated with a color electrical layer coating comprising red, green and blue Method for producing a color filter. The method of claim 1, When three regions of different initial levels of exposure energy are formed on the substrate, the substrate is prearranged in a matrix of black tint. Method for producing a color filter. The method of claim 1, The material forming the matrix of black tint is an organic polymer coating composition comprising an alloy or oxide of chromium and / or nickel, or a mixture thereof or a dispersed black pigment. Method for producing a color filter. The method of claim 1, When four regions of different initial levels of exposure energy are formed on the substrate, a black resin is coated onto the last region of the substrate, and steps (c) and (d) complete the electrical layer of all colors. Repeated to Method for producing a color filter. The method of claim 1, Further baking the substrate after step (e) to completely cure all color electrical layer resins. Method for producing a color filter.