JPH11218606A - Color filter and production of color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide color filters which are the color filters formed by using a resin black matrix and which hardly give rise to the problem of the occurrence of a display defect. SOLUTION: These color filters are formed by providing the surface of a transparent substrate 22 with a black matrix layer 24 formed by dispersing at least a shading agent into a resin and providing the apertures of the black matrix 24 and part on the black matrix 24 with respective colored layers of three primary colors. In such a case, the differences between the max. values and min. values of the differences in level ΔTR within the pixels of the red colored layers, differences in level ΔTG within the pixels of the green colored layers and differences in level ΔTS within the pixels of the blue colored layers of these color filters are below 0.5 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter used in a liquid crystal display device and a method of manufacturing the same.

[0002]

2. Description of the Related Art In general, a color filter is composed of a large number of picture elements, with a coloring layer of three primary colors of red, green and blue formed on a transparent substrate as one picture element. A light-shielding region (which is generally referred to as black matrix on a screen and is called a black matrix) is provided between the colored layers in order to increase display contrast.

As a method of forming a colored layer on a color filter, a method of dyeing a dyeable medium formed by photolithography, a method of using a photosensitive pigment dispersion composition, a method of non-photosensitive pigment dispersion composition, In addition to the method of etching objects, the electrodeposition method using patterned electrodes,
As a low-cost manufacturing method, there is a method of forming a colored portion by a printing method or an inkjet method.

A black matrix of a conventional color filter is often formed by patterning a finely patterned metal thin film or a resin colored with a light-shielding agent.

[0005]

In the case of a black matrix made of a metal thin film, reflected light is large, production costs are high, and harmful substances such as hexavalent chromium are generated during pattern processing. Contamination can be a problem. In the case of a black matrix composed of a multilayer film using a metal oxide or a metal nitride, although the reflected light is small, the problems of manufacturing cost and environmental pollution are not reduced. On the other hand, a black matrix obtained by patterning a resin colored with a light-shielding agent has an advantage of lower reflection than a metal thin film.
However, in a conventional color filter using a resin black matrix, poor alignment of liquid crystal occurs partially, and problems such as a decrease in contrast and an afterimage due to light leakage are likely to occur. Also, rubbing is likely to be non-uniform, and display defects are likely to occur. In particular, TN is used for an in-plane switching (IPS) type LCD characterized by a high viewing angle characteristic, an LCD using an antiferroelectric liquid crystal, and the like.
The non-uniformity of the cell gap is more sensitive and causes a display failure as compared with the LCD of the mode, which is an important problem.

Accordingly, an object of the present invention is to provide a color filter using a resin black matrix, which is less likely to cause a problem of display failure, and a method of manufacturing the same.

[0007]

Means for Solving the Problems As a result of intensive studies, the inventors of the present invention have found that when a resin black matrix is used, unevenness in pixels tends to be uneven, which results in uneven cell gaps, thereby resulting in poor display. The present invention has been completed by finding that this problem can be solved, and finding that this problem can be solved by making the variation of the step in the pixel equal to or less than a certain value.

That is, according to the present invention, a black matrix layer formed by dispersing at least a light-shielding agent in a resin is provided on a transparent substrate, and an opening of the black matrix and a part of the black matrix are respectively colored in three primary colors. In the color filter provided with the layers, the difference between the maximum value and the minimum value of the step ΔT _R in the pixel of the red coloring layer, the step ΔT _G in the pixel of the green coloring layer, and the step ΔT _B in the pixel of the blue coloring layer is 0.
Provided is a color filter having a size of 5 μm or less. In addition, the present invention provides a step of providing a black matrix layer formed by dispersing at least a light-shielding agent in a resin on a transparent substrate, and then coloring each of the three primary colors in the opening of the black matrix and a part of the black matrix. the method of manufacturing a color filter and a step of providing a layer, by polishing the surface of the colored layer, whereby the pixels of the red colored layer step [Delta] T _R, pixel level difference [Delta] T _G of the green coloring layer, the blue colored layer pixel A method of manufacturing a color filter, characterized in that the difference between the maximum value and the minimum value of the inner step ΔT _B is set to 0.5 μm or less.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The color filter of the present invention is provided with a black matrix layer formed by dispersing a light-shielding agent in a resin on a transparent substrate. It is processed and laminated on the opening and a part on the black matrix.

The transparent substrate used in the present invention is not particularly limited, and inorganic glass such as quartz glass, borosilicate glass, aluminosilicate glass, soda lime glass whose surface is coated with silica, and organic plastic. Films or sheets are preferably used.

A black matrix formed by dispersing a light-shielding agent in a resin is provided on a transparent substrate. The resin used for the black matrix is not particularly limited,
A photosensitive or non-photosensitive material such as an epoxy resin, an acrylic resin, a urethane resin, a polyester resin, a polyimide resin, a polyolefin resin, and a polyvinyl alcohol resin is preferably used. The resin for the black matrix is preferably a resin having higher heat resistance than the resin used for the pixels and the protective film, and a polyimide resin is preferably a resin having resistance to the organic solvent used in the process after the formation of the black matrix. Resins are particularly preferably used.

Here, the polyimide resin is not particularly limited, but is usually a polyimide precursor (n = 1) having a structural unit represented by the following general formula [I] as a main component.
~ 2) obtained by imidizing by heating or using a suitable catalyst are suitably used.

[0013]

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Further, the polyimide resin may contain a bond other than an imide bond such as an amide bond, a sulfone bond, an ether bond, and a carbonyl bond in addition to the imide bond.

In the general formula [I], R ¹ is a trivalent or tetravalent organic group having at least two or more carbon atoms.
From the viewpoint of heat resistance, R ¹ is preferably a trivalent or tetravalent group containing a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring and having 6 to 30 carbon atoms. Examples of R ¹ include phenyl, biphenyl, terphenyl, naphthalene, perylene, diphenylether, diphenylsulfone, diphenylpropane, benzophenone, biphenyltrifluoropropane, cyclobutyl, cyclopentyl, and the like. But not limited to these.

R ² is a divalent organic group having at least two or more carbon atoms. From the viewpoint of heat resistance, R ² contains a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring, and A divalent group having 6 to 30 carbon atoms is preferable. Examples of R ² include phenyl, biphenyl, terphenyl, naphthalene, perylene, diphenylether, diphenylsulfone, diphenylpropane, benzophenone, biphenyltrifluoropropane, diphenylmethane, cyclohexylmethane, and the like. But not limited thereto. The polymer having the structural unit [I] as a main component may be a copolymer in which R ¹ and R ² are each composed of one or more of them. . Further, in order to improve the adhesiveness to the substrate, it is preferable to copolymerize bis (3-aminopropyl) tetramethyldisiloxane having a siloxane structure as the diamine component as long as the heat resistance is not reduced.

Specific examples of the polymer having the structural unit [I] as a main component include pyromellitic dianhydride, 3,3 ′, 4,4′-
Benzophenonetetracarboxylic dianhydride, 3,3 ', 4,4'-
Selected from the group consisting of biphenyltrifluoropropanetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, etc. One or more carboxylic dianhydrides, paraphenylenediamine, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4 , 4'-Diaminodiphenylsulfone, 4,4'-Diaminodicyclohexylmethane, 4,4'-
Examples include, but are not limited to, polyimide precursors synthesized from one or more diamines selected from the group such as diaminodiphenylmethane. These polyimide precursors are synthesized by a known method, that is, by selectively combining tetracarboxylic dianhydride and diamine and reacting them in a solvent.

Examples of the light-shielding agent for the black matrix include a mixture of red, blue and green pigments in addition to metal oxide powders such as carbon black, titanium oxide and iron tetroxide, metal sulfide powders and metal powders. Can be used. Among them,
In particular, carbon black has excellent light-shielding properties and is particularly preferable. Since carbon black having a good dispersion and a small particle size mainly exhibits a brownish color tone, it is preferable to mix a pigment of a complementary color to carbon black to obtain an achromatic color.

When the resin for the black matrix is polyimide, the black paste solvent is usually N-methyl-2-pyrrolidone, N, N-dimethylacetamide,
Amide polar solvents such as N, N-dimethylformamide,
A lactone polar solvent such as γ-butyrolactone is preferably used.

As a method for dispersing a light-shielding agent such as a pigment of a complementary color to carbon black or carbon black, for example, after mixing a light-shielding agent or a dispersing agent in a polyimide precursor solution, a three-roll Sand grinder,
There is a method of dispersing in a dispersing machine such as a ball mill, but the method is not particularly limited. In addition, various additives may be added for improving the dispersibility of carbon black, or for improving applicability and leveling property.

As a method for producing a resin black matrix, a black paste is applied to a transparent substrate, dried,
Perform patterning. As a method for applying the black paste, a dip method, a roll coater method, a spinner method, a die coating method, a method using a wire bar, and the like are suitably used, and thereafter, heat drying (semi-curing) is performed using an oven or a hot plate. . The semi-curing conditions vary depending on the resin, solvent and paste coating material used, but it is usually preferable to heat at 60 to 200 ° C. for 1 to 60 minutes.

In the case where the resin is a non-photosensitive resin, the black paste film thus obtained is formed after forming a positive photoresist film on the non-photosensitive resin. In some cases, exposure and development are performed as they are or after forming an oxygen barrier film. If necessary, the positive photoresist or the oxygen barrier film is removed, and the film is dried by heating (this cure). The curing conditions are slightly different depending on the coating material when a polyimide resin is obtained from the precursor, but it is generally heated at 200 to 300 ° C. for 1 to 60 minutes. Through the above process, a black matrix is formed on the transparent substrate.

The thickness of the resin black matrix is preferably 0.5 to 1.5 μm, more preferably 0.8 to 1.5 μm.
1.3 μm. If the thickness is smaller than 0.5 μm, the light-shielding property becomes insufficient, which is not preferable.
On the other hand, when the film thickness is larger than 1.5 μm, although the light-shielding property can be ensured, the flatness of the color filter is easily sacrificed, and a step is easily generated. When a step in a pixel occurs, even if a transparent conductive film or a liquid crystal alignment film is formed on the color filter, the step is hardly reduced, and the alignment treatment by rubbing of the liquid crystal alignment film becomes non-uniform or the cell gap varies. And the display quality of the liquid crystal display element is degraded. In such a case, in order to reduce the surface step, it is effective to provide a transparent protective film on the colored layer.

The light-shielding property of the resin black matrix is represented by an OD value (common logarithm of the reciprocal of transmittance).
In order to improve the display quality of the liquid crystal display device, it is preferably at least 2.5, more preferably at least 3.0. The preferred range of the thickness of the resin black matrix has been described above, but the upper limit of the OD value should be determined in relation to this.

The reflectance of the resin black matrix is a reflectance (Y value) corrected for visibility in a visible region of 400 to 700 nm in order to reduce the influence of reflected light and improve the display quality of a liquid crystal display device. It is preferably at most 2%, more preferably at most 1%.

Usually, (2)
An opening of 0 to 200) μm × (20 to 300) μm is provided.
A plurality of primary color layers are arranged. That is,
One opening is covered with any one of the three primary color layers, and a plurality of color layers of each color are arranged.

The coloring layer constituting the color filter contains at least three primary colors. That is, when performing color display by the additive color method, three primary colors of red (R), green (G), and blue (B) are selected. When performing color display by the subtractive color method, cyan (C) and magenta are used. (M) and three primary colors of yellow (Y) are selected. Generally, a picture element for color display can be formed by using an element including these three primary colors as one unit. For the coloring layer, a resin colored with a coloring agent is used.

As the coloring agent used in the coloring layer, organic pigments, inorganic pigments, dyes and the like can be suitably used. Further, various additives such as an ultraviolet absorber, a dispersing agent and a leveling agent are added. You may. As the organic pigment, phthalocyanine-based, aziraki-based, condensed azo-based, quinacridone-based, anthraquinone-based, perylene-based, and perinone-based pigments are preferably used.

As the resin used for the colored layer, a photosensitive or non-photosensitive material such as an epoxy resin, an acrylic resin, a urethane resin, a polyester resin, a polyimide resin, and a polyolefin resin is preferably used. It is preferable to disperse or dissolve the agent in these resins for coloring. Examples of the photosensitive resin include photodecomposable resins, photocrosslinkable resins, and photopolymerizable resins.Especially, monomers, oligomers or polymers having an ethylenically unsaturated bond and an initiator that generates radicals by ultraviolet rays are used. A photosensitive composition, a photosensitive polyamic acid composition and the like are preferably used. As the non-photosensitive resin, those which can be developed with the above various polymers are preferably used.
A resin having heat resistance enough to withstand such heat in a film forming process of a transparent conductive film or a manufacturing process of a liquid crystal display device is preferable, and a resin having resistance to an organic solvent used in a manufacturing process of a liquid crystal display device. Is preferred, and a polyimide resin is particularly preferably used. Here, as a preferable polyimide resin, a polyimide resin preferably used as a material of the above-described resin black matrix can be exemplified.

As a method for forming a colored layer, patterning is performed after coating and drying on a substrate on which a resin black matrix is formed. As a method of obtaining a colored paste by dispersing or dissolving the colorant, after mixing the resin and the colorant in a solvent, three-roll, sand grinder, there is a method of dispersing in a dispersing machine such as a ball mill, The method is not particularly limited.

As a method for applying the colored paste, a dipping method, a roll coater method, a spinner method, a die coating method, a method using a wire bar, or the like is preferably used, as in the case of the black paste. Heat drying (semi-cure) is performed using a plate. The semi-curing conditions vary depending on the resin used, the solvent, and the amount of the paste applied, but it is usually preferable to heat at 60 to 200 ° C. for 1 to 60 minutes.

In the case where the resin is a non-photosensitive resin, the colored paste film thus obtained is formed after a positive photoresist film is formed thereon, and then the resin is a photosensitive resin. In some cases, exposure and development are performed as they are or after forming an oxygen barrier film. If necessary, the positive type photoresist or the oxygen blocking film is removed and dried by heating (this cure). The curing conditions vary depending on the resin, but when a polyimide resin is obtained from the precursor, it is generally heated at 200 to 300 ° C. for 1 to 60 minutes. Through the above process, a patterned colored layer is formed on the substrate on which the black matrix is formed.

After the first color layer is formed over the entire surface of the substrate on which the black matrix is formed as described above, unnecessary portions are removed by photolithography to obtain a desired pattern of the first color layer. To form
In this case, the coloring layer is left at least in the portion covering the opening of the black matrix and in the portion where the spacer is formed by laminating the coloring layer. The same operation is repeated for the second color and the third color, and a colored layer is formed such that one colored layer remains on the opening of the resin black matrix and three colored layers remain on the spacer.

The thickness of the three primary colors is not particularly limited, but is preferably 0.9 to 3 μm per layer. When the thickness of the coloring layer is 0.9 μm or less, the inclination angle of the surface of the color filter on the pattern edge of the black matrix becomes large, and poor alignment is likely to occur. On the other hand, when the film thickness is 3
If it exceeds μm, it becomes difficult to apply the colored layer uniformly. Also,
The overlapping width of the pattern of each colored layer and the black matrix layer is preferably 3 μm or less.

A transparent protective film can be formed on the colored layer, if necessary. As the resin used for the transparent protective film, epoxy resin, acrylic resin, urethane resin, polyester resin, polyimide resin, polyolefin resin, gelatin and the like are preferably used. A resin having a heat resistance that can withstand such heat in a liquid crystal display device manufacturing process is preferable, and a resin having a resistance to an organic solvent used in a liquid crystal display device manufacturing device is preferable. And an acrylic resin are preferably used.

As a method for applying the transparent protective film, a dip method, a roll coater method, a spinner method, a die coating method, a method using a wire bar, and the like are preferably used as in the case of the black paste and the colored paste. And heat drying using an oven or a hot plate. At this time, vacuum drying and preliminary heating drying (semi-curing) may be performed as needed for the purpose of improving the leveling property.
The semi-curing conditions vary depending on the resin, solvent and paste applied amount, but it is usually preferable to heat at 60 to 200 ° C. for 1 to 60 minutes. The curing conditions during heating and drying vary depending on the resin. When a polyimide resin is obtained from the precursor, the curing condition is slightly different depending on the amount of application.
Generally, heating is performed at 00 to 300 ° C. for 1 to 60 minutes.

The thickness of the transparent protective film is 0.05 to 3.0 μm.
Is preferred. Thickness is more effective in reducing the level difference in the pixel, but uniform coating becomes difficult. Further, it can be suitably selected from combinations of the thicknesses of the black matrix layer and the colored layer.

In the color filter of the present invention, the step ΔT _R in the pixel of the red coloring layer, the step ΔT _{G in} the pixel of the green coloring layer,
The difference between the maximum value and the minimum value of the in-pixel step ΔT _B of the blue colored layer is 0.5 μm or less, preferably 0.2 μm or less. The “intra-pixel step ΔT” referred to in the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view of a color filter. The color filter shown in FIG. 1 has a black matrix 24 on a transparent substrate 22 and a coloring layer 26 provided on the opening of the black matrix 24 and on a part of the outer black matrix. The coloring layer 26 is flat on the pattern of the black matrix 24 as shown in the figure, but on the pattern of the black matrix 24, the coloring layer 26 rises for the black matrix 24 as shown. If necessary, the transparent electrode 30 may be provided thereon, but the swelling on the black matrix is not eliminated. The step between the flat portion of the opening of the manufactured color filter and the peak of the swelling is defined as “in-pixel step ΔT” defined in the present invention. In addition,
The step ΔT in the pixel can be measured by using a surface step meter, for example, DEKTAK manufactured by Nippon Vacuum.

The coloring layer pattern of the color filter will be described with reference to FIG. FIG. 2 is a schematic view of the color filter observed in a plan view. In FIG. 2, 14 is a resin black matrix, 3 is a colored layer such as a blue colored layer (B), 4 is a colored layer such as a red colored layer (R), 5 Is a colored layer, for example, a green colored layer (G). In the case of a color filter in which the three primary colors are periodically arranged at a constant pitch, the color layer pattern in the direction in which the same colors are continuous must be formed on a stripe as shown in (1) of FIG. There are many. However, in order to realize the step requirement defined in the present invention,
It is preferable that the colored layer is not formed on the entire surface of the black matrix pattern between the openings and is formed on the island as shown in FIG. 2 (2). In the case of processing by a photolithography method, the shape of the pattern can be arbitrarily selected depending on the pattern processing conditions of a photomask used for forming a colored layer.

After the color filter is manufactured, the step ΔT in the pixel
When the difference between the maximum value and the minimum value is not within the range specified by the present invention, the step in the pixel is reduced by polishing the surface of the colored layer on the color filter substrate, and the difference defined by the present invention is obtained. Range.

The polishing can be carried out by buff polishing which is usually used. As the abrasive, alumina particles, cerium oxide particles, and the like are preferably used, but are not particularly limited thereto. As the buffing material, a nonwoven fabric, a suede type, and the like are widely used. The polishing conditions are not particularly limited, but the surface pressure is 10 to 100 g / cm ² for 10 seconds to 5 seconds.
It is preferable to carry out in minutes. If the surface pressure becomes too strong, the amount of polishing increases, making it difficult to control the amount of polishing and causing polishing scratches. Also, if the surface pressure is too low, it will not be sufficiently polished,
It is difficult to reduce the step in the pixel.

When the polishing is performed, it is preferable to uniformly polish the entire surface of the color filter substrate. It should be noted that the difference between the maximum value and the minimum value of the step in the pixel defined by the present invention can be achieved without polishing by making the pattern of the colored layer an island shape, optimizing the thickness of the colored layer or the black matrix, or the like. May be achieved, but in this case, polishing after the production of the color filter may not be performed.

Next, a color liquid crystal display device manufactured using the above color filter and TFT substrate will be described. FIG. 3 schematically shows a cross-sectional view of a preferred specific example of the color liquid crystal display device. In FIG. 3, 1 is a transparent substrate, 2 is a resin black matrix, 3 is a colored layer such as (B), 4 is a colored layer such as (R), 5 is a colored layer such as (G), 6 is a transparent electrode, and 7 is an orientation. It is a membrane. On the other hand, 13
Is a transparent substrate of a transparent electrode substrate facing the color filter, 12 is an electrode attached to a liquid crystal drive circuit, 11 is an insulating film, 10 is a pixel electrode, and 9 is an alignment film. Reference numeral 8 denotes a liquid crystal sandwiched between the color filter and the TFT substrate. Spherical or rod-like spacers 16 for maintaining a cell gap are dispersed between the color filter and the TFT substrate.
As shown in FIG. 3, the liquid crystal display device is manufactured with the color filter and the transparent electrode substrate facing each other.

On the color filter, if necessary,
A transparent electrode such as a TO film is formed. In recent years, in the case of an IPS type liquid crystal display element which has been widely used because of its excellent visual characteristics, a transparent electrode is not formed on a color filter. As the transparent electrode substrate facing the color filter, a transparent electrode such as an ITO film is provided in a pattern on the TFT substrate. Color filter and TF
A liquid crystal alignment film is provided on the surface of the T substrate, and an alignment process such as rubbing is performed. After the alignment process, the color filter and the transparent electrode are attached to each other, and after the liquid crystal is injected through an injection hole provided in the seal portion, the injection hole is sealed. The module is completed by mounting an IC driver and the like after attaching the polarizing plate to the outside of the substrate.

The color liquid crystal display device of the present invention is used for display screens of personal computers, word processors, engineering workstations, navigation systems, liquid crystal televisions, videos, etc., and is also suitable for liquid crystal projection for providing clear images. Used for

[0046]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention.

Example 1 (1) Preparation of resin black matrix 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 4,4'
-Diaminodiphenyl ether and bis (3-aminopropyl) tetramethyldisiloxane with N-methyl-2-
The reaction was performed using pyrrolidone as a solvent to obtain a polyimide precursor (polyamic acid) solution.

Using a homogenizer, a carbon black mill base having the following composition was dispersed at 7000 rpm for 30 minutes, and the glass beads were filtered to prepare a black paste.

Composition based on carbon black mill base Carbon black (MA100, manufactured by Mitsubishi Kasei Corporation) 4.6 parts Polyimide precursor solution 24.0 parts N-methylpyrrolidone 61.4 parts Glass beads 90.0 parts

Glass substrate (Corning, 1737 material)
Was coated with a curtain flow coater and dried on a hot plate at 130 ° C. for 10 minutes to form a black resin coating film. After applying a positive photoresist (manufactured by Shipley Co., SRC-100) with a reverse roll coater, pre-baking at 100 ° C. for 5 minutes on a hot plate, and irradiating with 100 mJ / cm ² ultraviolet rays using an ultra-high pressure mercury lamp, and then performing mask exposure, Using a 2.25% aqueous solution of tetramethylammonium hydroxide, the development of the photoresist and the etching of the resin coating are simultaneously performed to form a pattern, the resist is peeled off with methyl cellosolve acetate, and heated at 300 ° C. for 10 minutes on a hot plate By doing so, imidization was performed to form a black matrix layer.

The measured thickness of the black matrix layer was 1.15 μm, and the OD value was 3.5.

(2) Preparation of Colored Layer Next, Color Index No. 653 was used as a red, green and blue pigment, respectively.
00 Dianthraquinone pigment represented by Pigment Red 177, Color Index No. 74265 Phthalocyanine green pigment represented by Pigment Green 36, Color Index No. 74
A phthalocyanine blue pigment represented by 160 Pigment blue 15-4 was prepared. The pigments were mixed and dispersed in a polyimide precursor solution to obtain three kinds of colored pastes of red, green and blue.

Next, a red paste was applied on a resin black matrix substrate by a curtain flow coater, and dried at 130 ° C. for 10 minutes on a hot plate to form a red resin coating film. After that, a positive photoresist (SRC-100, manufactured by Shipley Co., Ltd.) was applied with a reverse roll coater, and prebaked at 100 ° C. for 5 minutes on a hot plate.
After mask exposure by irradiating 100 mJ / cm ² ultraviolet rays using an ultra-high pressure mercury lamp, using a 2.25% aqueous solution of tetramethylammonium hydroxide, the development of the photoresist and the etching of the resin coating are simultaneously performed to form a pattern. Formation, resist stripping with methyl cellosolve acetate,
It was imidized by heating at 300 ° C. for 10 minutes on a hot plate to form a red colored layer. The pattern of the mask was a stripe pattern, and the formed red coloring layer pattern was also a stripe pattern. The thickness of the red colored layer at the black matrix opening was measured and found to be 1.2 μm.

After washing with water, a green paste was applied to a substrate having a red coloring layer formed on a resin black matrix in the same manner, followed by pattern processing to form a green coloring layer. The thickness of the green colored layer measured at the opening of the black matrix was 1.15 μm.

After washing with water, a blue paste was applied and patterned on a substrate having a red and green colored layer formed on the resin black matrix layer in the same manner to form a blue colored layer. When the film thickness of the blue colored layer at the black matrix opening was measured, it was 1.2 μm.

(3) Preparation of Transparent Protective Film and Transparent Electrode Then, a solution of polyamic acid in N-methyl-2-pyrrolidone / butyl cellosolve was applied by a spin coater so that the finished film thickness became 1.0 μm. The plate was heated at 280 ° C. for 10 minutes to form an overcoat layer, and an ITO film was formed by a sputtering method. As a result, the film thickness was 140 nm and the surface resistance was 15 Ω / □.

(4) Measurement of Steps in Pixels The steps ΔT in the pixels in the pixels of each color layer of the color filter manufactured in this manner were measured using a surface step meter (manufactured by Nihon Vacuum, DE
KTAK), the following results were obtained.

Red coloring layer Blue side 0.41 μm, green side 0.36 μm, long side of opening 0.61 μm Green coloring layer Red side 0.34 μm, blue side 0.26 μm, long side of opening 0.61 μm blue coloring layer Green side 0.31 μm, red side 0.27 μm, long side of opening 0.55 μm

The maximum value of the step in the pixel at this time is 0.61 μm on the long side of the opening of the red coloring layer or the green coloring layer, and the minimum value is 0.26 μm on the blue side of the green coloring layer. The difference between the maximum value and the minimum value of the inner step is 0.35 μm.

(5) Production of Color Liquid Crystal Display Element After the color filter substrate was washed with a neutral detergent, an alignment film made of a polyimide resin was applied by a printing method, and baked on a hot plate at 250 ° C. for 10 minutes. The film thickness is 0.07
μm. Thereafter, the color filter substrate was subjected to a rubbing treatment, a sealant was applied by a dispense method, and baked on a hot plate at 90 ° C. for 10 minutes.

On the other hand, a substrate having a TFT array formed on a Corning glass substrate 1737 was similarly washed, and then an alignment film was applied and baked. After that, spray the spacer,
The resin was superposed on the color filter substrate and baked at 160 ° C. for 90 minutes while pressurizing in an oven to cure the resin. After vacuum annealing this cell at 150 ° C. and 10 ⁻³ torr, the pressure was once returned to normal pressure under a nitrogen atmosphere, and liquid crystal was injected again in a vacuum atmosphere. The pressure was reduced to 10 ^{@ 3} torr at room temperature liquid crystal injection put the cell into the chamber, immersed liquid crystal injection hole in the liquid crystal tank, it went back to normal pressure with nitrogen. After injecting the liquid crystal, the liquid crystal injection hole was sealed using a UV curable resin. The panel was heated to a temperature equal to or higher than the NI transition point to reorient the liquid crystal.

Next, a polarizing plate was attached to the two glass substrates of the cell, and the temperature was set to 50 ° C. and the pressure was set to 5 kg in an autoclave.
The cell was completed under the conditions of f / cm ² . As a result of observing the obtained liquid crystal display element with a microscope, it was found that there was no problem such as light leakage due to poor alignment. Further, when displaying, no unevenness due to uneven cell gap was confirmed, and the quality was good.

Example 2 A color filter was produced by forming a transparent electrode in Example 1 without forming a transparent protective film. Thereafter, the step ΔT in the pixel was measured by the surface step meter in the same manner as in Example 1. Write the result.

Red colored layer Blue side 1.18 μm, green side 1.19 μm, long side of opening 1.02 μm Green colored layer Red side 1.05 μm, blue side 1.10 μm, long side of opening 1.00 μm Blue colored layer Green side 1.05μm, red side 1.07μm, opening long side 0.97μm

At this time, the maximum value of the step in the pixel is 1.19 μm on the green side of the red coloring layer, and the minimum value is 0.97 μm on the long side of the opening of the blue coloring layer. The difference between the value and the minimum value is 0.22 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, slight light leakage was observed around the black matrix opening, but the display quality was good and the contrast was 100: 1 or more.

Example 3 A color filter was produced in the same manner as in Example 1 except that the thickness of the red, blue and green colored layers was changed to 1.6 μm, and the step in the pixel was measured. Was obtained.

Red coloring layer Blue side 0.41 μm, green side 0.39 μm, long side of opening 0.64 μm Green coloring layer Red side 0.38 μm, blue side 0.36 μm, long side of opening 0.56 μm blue coloring layer Green side 0.33μm, red side 0.32μm, long side of opening 0.62μm

At this time, the maximum value of the step in the pixel is 0.64 μm on the long side of the opening of the red coloring layer, and the minimum value is 0.32 μm on the red side of the blue coloring layer. The difference between the value and the minimum value is 0.32 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no problem except that slight light leakage was observed on the long side of the opening. Further, when displayed, the contrast was as good as 120: 1, and no display unevenness due to uneven cell gap was observed.

Example 4 A color filter was prepared in the same manner as in Example 1 except that the thickness of the red, blue and green colored layers was changed to 1.6 μm, and the pattern of the colored layers was changed to an island pattern. The measurement of the inner step was performed. The results were as follows.

Red coloring layer Blue side 0.39 μm, green side 0.34 μm, long side of opening 0.43 μm green coloring layer Red side 0.36 μm, blue side 0.31 μm, long side of opening 0.36 μm blue coloring layer Green side 0.37μm, red side 0.34μm, long side of opening 0.37μm

At this time, the maximum value of the step in the pixel is 0.43 μm on the long side of the opening of the red coloring layer, and the minimum value is 0.31 μm on the blue side of the green coloring layer. The difference between the value and the minimum value is 0.12 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no problem such as light leakage due to poor orientation, and when displaying, no display unevenness due to uneven cell gap was confirmed, and the quality was good.

Comparative Example 1 A color filter was prepared in the same manner as in Comparative Example 1 except that the thicknesses of the red, blue and green colored layers were changed to 2.2 μm, and the step in the pixel was measured. Was obtained.

Red coloring layer Blue side 1.38 μm, green side 1.45 μm, long side of opening 1.02 μm green coloring layer Red side 1.07 μm, blue side 1.15 μm, long side of opening 1.00 μm blue coloring layer Green side 0.82 μm, red side 0.95 μm, opening long side 0.94 μm

At this time, the maximum value of the step in the pixel is 1.45 μm on the green side of the red coloring layer, and the minimum value is 0.82 μm on the green side of the blue coloring layer. The difference between the minimum values is 0.63 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, light leakage was confirmed around the black matrix opening, and the display quality was poor. As a result of measuring the contrast, it was lower than that of Example 1 and was 80: 1. Also, as a result of measuring the gap of this cell, the average value was about 0.3 μm thicker than in Example 1, and the in-plane variation was large.

Example 5 In Example 2, after forming the red, blue and green colored layers, the entire surface of the substrate was polished, and ITO was deposited to a thickness of 1 by sputtering.
A color filter substrate was manufactured by forming a mask so as to have a thickness of 40 nm. The following results were obtained by measuring the step in the pixel of this substrate.

Red coloring layer Blue side 0.05 μm, green side 0.07 μm, long side of opening 0.45 μm green coloring layer Red side 0.19 μm, blue side 0.15 μm, long side of opening 0.48 μm blue coloring layer Green side 0.09 μm, red side 0.09 μm, long side of opening 0.37 μm

At this time, the maximum value of the step in the pixel is 0.48 μm on the long side of the opening of the green coloring layer, and the minimum value is 0.05 μm on the blue side of the red coloring layer. The difference between the value and the minimum value is 0.43 μm.

At this time, the change in the film thickness at the pixel opening before and after polishing was 0.2 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no light leakage around the black matrix opening, and the display quality was good. Also, as a result of measuring the contrast,
All were 100: 1 or more.

Example 6 In Example 4, after forming the red, blue and green colored layers, the entire surface of the substrate was polished, and ITO was deposited to a thickness of 1 by sputtering.
A color filter substrate was manufactured by forming a mask so as to have a thickness of 40 nm. The following results were obtained by measuring the step in the pixel of this substrate.

Red colored layer Blue side 0.05 μm, green side 0.07 μm, long side of opening 0.09 μm green colored layer Red side 0.19 μm, blue side 0.15 μm, long side of opening 0.14 μm blue colored layer Green side 0.09 μm, red side 0.09 μm, long side of opening 0.10 μm

At this time, the maximum value of the step in the pixel is 0.19 μm on the red side of the green coloring layer, and the minimum value is 0.05 μm on the blue side of the red coloring layer. The difference between the minimum values is 0.14 μm.

The change in film thickness at the pixel opening before and after polishing was 0.2 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no light leakage around the black matrix opening, and the display quality was good. Also, as a result of measuring the contrast,
All were 100: 1 or more. When the cell gap was measured, the in-plane distribution was good within 0.2 μm.

Example 7 In Example 1, the thickness of the red, blue and green colored layers was changed to 1.9.
μm to produce a color filter. When the surface steps were measured, the results were as follows.

Red coloring layer Blue side 0.45 μm, green side 0.43 μm, long side of opening 0.46 μm green coloring layer Red side 0.35 μm, blue side 0.33 μm, long side of opening 0.34 μm blue coloring layer Green side 0.41 μm, red side 0.32 μm, long side of opening 0.42 μm

At this time, the maximum value of the step in the pixel is 0.46 μm on the long side of the opening of the red coloring layer, and the minimum value is 0.32 μm on the red side of the blue coloring layer. The difference between the value and the minimum value is 0.14 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no light leakage around the black matrix opening, the contrast was good, and no display unevenness due to the cell gap was confirmed.

Example 8 A color filter was prepared in the same manner as in Example 7 except that the transparent protective film was changed to acrylic resin, and the step in the pixel was measured. The results were as follows.

Red coloring layer Blue side 0.17 μm, green side 0.16 μm, long side of opening 0.19 μm green coloring layer Red side 0.11 μm, blue side 0.14 μm, long side of opening 0.10 μm blue coloring layer Green side 0.13μm, red side 0.05μm, opening long side 0.08μm

At this time, the maximum value of the step in the pixel is 0.19 μm on the long side of the opening of the red coloring layer, and the minimum value is 0.05 μm on the red side of the blue coloring layer. The difference between the value and the minimum value is 0.14 μm.

Using this color filter, a color liquid crystal display device was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no light leakage around the opening of the black matrix, and the cell gap unevenness was observed.

Example 9 A color filter was prepared in the same manner as in Example 8 except that the thickness of the transparent protective film was changed to 1.4 μm, and the step in the pixel was measured. The results were as follows.

Red coloring layer Blue side 0.08 μm, green side 0.10 μm, long side of opening 0.03 μm green coloring layer Red side 0.08 μm, blue side 0.09 μm, long side of opening 0.06 μm blue coloring layer Green side 0.05μm, red side 0.10μm, opening long side 0.03μm

At this time, the maximum value of the step in the pixel is 0.10 μm on the green side of the red coloring layer and the red side of the blue coloring layer, and the minimum value is 0 μm on the long side of the opening of the red coloring layer and the blue coloring layer. .
Since it is 03 μm, the difference between the maximum value and the minimum value of the step in the pixel is 0.07 μm.

The step in the pixel and the difference between the maximum value and the minimum value are smaller than in the eighth embodiment. Using this color filter, a color liquid crystal display element was produced in the same manner as in Example 1, and observed with a microscope. As a result, there was no light leakage around the opening of the black matrix, and as a result of observing cell gap unevenness, it was extremely uniform and good.

[0101]

The color filter of the present invention has a structure in which the black matrix layer is made of resin and the difference between the maximum value and the minimum value of the step in the pixel of the color filter is 0.5 μm or less. When a liquid crystal display device is manufactured by using this, it is possible to prevent the occurrence of display defects due to non-uniform cell gaps and to display excellent image quality.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view for explaining a step in a color filter pixel defined by the present invention.

FIG. 2 is a schematic diagram for explaining a configuration of an island pattern color filter defined by the present invention.

FIG. 3 is a schematic sectional view of a color liquid crystal display device using the color filter of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent substrate (glass substrate) 2 resin black matrix 3 colored layer (B) 4 colored layer (R) 5 colored layer (G) 6 transparent electrode 7 alignment film 8 liquid crystal 9 alignment film 10 pixel electrode 11 insulating film 12 liquid crystal drive circuit Attached electrode 13 Transparent substrate (glass substrate) 16 Spacer 22 Transparent substrate 24 Resin black matrix 26 Colored layer 28 Transparent film 30 Transparent electrode

Claims (6)

[Claims] 1. A black matrix layer formed by dispersing at least a light-shielding agent in a resin on a transparent substrate, and each of the three primary color layers is provided on an opening of the black matrix and a part of the black matrix. In the color filter, the difference between the maximum value and the minimum value of the step ΔT _R in the pixel of the red coloring layer, the step ΔT _G in the pixel of the green coloring layer, and the difference ΔT _B in the pixel of the blue coloring layer is 0.5 μm or less. Characteristic color filter. 2. The color filter according to claim 1, wherein the transparent electrode layer is provided on the coloring layer. 3. The color filter according to claim 1, wherein the transparent electrode is provided on the coloring layer via a transparent film. 4. A step ΔT _{R on} the surface of the red coloring layer, a step ΔT _G in the pixel of the green coloring layer, and a step ΔT _{B in} the pixel of the blue coloring layer.
4. The color filter according to claim 1, wherein the difference between the maximum value and the minimum value is 0.2 μm or less. 5. The color filter according to claim 1, wherein the pattern of the red coloring layer, the green coloring layer, and the blue coloring layer has an island shape. 6. A step of providing, on a transparent substrate, at least a black matrix layer obtained by dispersing at least a light-shielding agent in a resin; The step of providing a color filter, the surface of the colored layer is polished, whereby the step ΔT _R in the pixel of the red colored layer, the step ΔT _{G in} the pixel of the green colored layer,
A method for manufacturing a color filter, wherein a difference between a maximum value and a minimum value of a step ΔT _B in a pixel of a blue coloring layer is set to 0.5 μm or less.