JPH1073716A - Color filter and color liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a display defect (irregular cell gap) due to variance in height of a spacer and to improve contrast in display quality by controlling a variance in the height of the spacer comprising a black matrix and three color layers formed on the black matrix (the sum height of four layers) in a color filter screen to a specified value or smaller. SOLUTION: Plural number of dot-like spacers formed by depositing color layers of three primary colors are distributed on a part of a black matrix. The variance of the length of the black matrix and dot-like spacers on the black matrix in the normal line direction of the color filter substrate plane is controlled to <0.6μm in the color filter screen. To decrease the variance in the screen, such a coating means that does not principally caused certain tendency to produce uneven film thickness is used, and for example, a slit die coating device, bar coating device and roll coating device can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter having a spacer function and a color liquid crystal display device using the same.

[0002]

2. Description of the Related Art In order to maintain the thickness (cell gap) of a liquid crystal layer, a color liquid crystal display device conventionally used generally includes a thin film transistor (TFT), an electrode substrate having a plurality of scanning electrodes, and a color substrate. Plastic beads, glass beads, or glass cut fibers are provided as spacers between the filter side substrate. Since spacers such as plastic beads are scattered here, it is not fixed at which position (in-plane position) the electrode substrate and the color filter substrate are arranged.

JP-A-56-140324 and JP-A-63-143
82405, JP-A-4-93924, JP-A-5-196
946 proposes a liquid crystal display device using a structure in which colored layers forming a color filter are overlapped as a spacer.

[0004]

In a color liquid crystal display device using a plastic bead or the like as a spacer, the position of the spacer such as a plastic bead is not fixed, and the liquid crystal is scattered or transmitted by the spacer located on the pixel. There is a problem that the display quality of the display element is reduced.

A liquid crystal display element using a spacer such as a plastic bead dispersedly has the following other problems. That is, the spacer has a spherical or rod-like shape, and contacts with a point or a line during cell compression,
There is a disadvantage that the alignment film and the transparent electrode are damaged, and display defects are likely to occur. Further, there is a disadvantage that the liquid crystal is contaminated by the damage of the alignment film and the transparent electrode, and the effective voltage applied to the liquid crystal is easily lowered.

In addition, since a step of uniformly dispersing the spacers is required or the particle size distribution of the spacers needs to be controlled with high precision, a liquid crystal display element having stable display quality can be provided by a simple method. Difficult to get.

To solve these problems, Japanese Patent Application Laid-Open No.
40324, JP-A-63-82405, JP-A-4-93
924, JP-A-5-196946 describes two colors or three colors.
It has been proposed to use a structure in which colored layers of colors are overlapped as a spacer. The thickness (cell gap) of the liquid crystal layer actually obtained by these disclosed technologies is the thickness of one or two colored layers, and it is difficult to obtain a liquid crystal display device having a sufficient cell gap. Layer 1
Even if the cell gap can be maintained with the thickness of one layer or two layers, for example, the durability of the ITO film formed on the color filter is reduced due to the increase in the thickness of the colored layer, and satisfactory reliability is obtained. It is difficult to obtain a liquid crystal display device having the same.

Furthermore, in order to form the dot-shaped spacer by laminating the respective colored layers, it is necessary that the paint for forming the second and third layers has a certain level of viscosity and leveling resistance. This is to prevent the coating film serving as a spacer, which is applied on the base provided by the first layer and the 1 + 2 layer stacking, from becoming thinner than other portions due to leveling flowing into the peripheral portion. However, the use of a coating material having a high viscosity and being difficult to be leveled impairs the uniformity of the film thickness in the color filter screen and causes a variation in the height of the colored layer. Since the height of the dot spacer on which the colored layer is laminated directly determines the cell gap, the variation in the height of the dot spacer is likely to significantly impair the display quality when the liquid crystal display device is used as a cell gap. .

Conventionally, a spinner (spin coater) is usually used to form a colored layer of a color filter. However, if a method having a certain tendency in the non-uniform distribution of film thickness is adopted, such as a spinner which is likely to become a thick film in principle like a spinner in the formation of a coating film, when two or four layers are laminated, The unevenness is emphasized as a result, which is particularly disadvantageous. Such inconvenience is the same even in the case of designing (manufacturing multiple panels) a large number of color filters on one glass substrate.

In view of the above problems, the present invention realizes a sufficient cell gap and avoids the possibility of display defects (cell gap unevenness) caused by variations in the height of spacers of a color filter. It is an object of the present invention to provide a color filter capable of overcoming the conventional disadvantages described above and a color liquid crystal display device using the same.

[0011]

Means for Solving the Problems As a result of intensive studies, the inventors of the present invention have found that the height of a spacer consisting of a black matrix and three colored layers formed thereon (total height of a total of four layers) is reduced. By suppressing the variation in the color filter screen to a predetermined value or less, it has been found that a display defect (cell gap unevenness) caused by the variation in the height of the spacer can be avoided, and the present invention has been completed.

That is, the present invention provides a color filter comprising a black matrix provided on a transparent substrate, and three primary color layers provided so as to cover an opening of the black matrix and a part of the black matrix. (A) 3 parts on the black matrix
A plurality of dot-shaped spacers formed by laminating the respective colored layers of the primary colors are provided, and (B) the length H of the black matrix and the dot-shaped spacers provided on the black matrix in the normal direction to the plane of the color filter substrate. A variation in the color filter screen of 0.6 μm or less is provided.
Furthermore, the present invention provides a color liquid crystal display device comprising a pair of transparent substrates having transparent electrodes and a liquid crystal layer sandwiched between these transparent substrates, wherein one of the substrates is the color filter of the present invention. A color liquid crystal display device is provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The color filter of the present invention is one in which a black matrix is provided on a transparent substrate, and a plurality of colored layers of three primary colors are arranged thereon. As the black matrix, a resin black matrix composed of a resin and a light-shielding agent is preferable. The color filter is composed of a large number of picture elements, with pixels covered by each of the three primary color layers as one picture element. Here, the black matrix indicates a light-shielding region arranged between the pixels, and is provided to improve the display contrast of the liquid crystal display device.

The transparent substrate used for the color filter is not particularly limited, and inorganic glass such as quartz glass, borosilicate glass, aluminosilicate glass, and soda lime glass having a silica coated surface,
Organic plastic films or sheets are preferably used.

A black matrix is provided on the transparent substrate. The black matrix may be formed of a metal such as chromium or an oxide thereof, but it is preferable to form a resin black matrix composed of a resin and a light-shielding agent in terms of manufacturing costs and waste disposal costs. In this case, the resin used for the black matrix is not particularly limited, but is 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. 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.

[0017]

Embedded image

The polyimide resin may contain a bond other than the 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 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 on 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 obtained in this manner is formed after forming a positive type 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.
1.2 μm. If the thickness is smaller than 0.5 μm, it is difficult to secure a sufficient cell gap, and
It is not preferable because the light-shielding property becomes insufficient. on the other hand,
When the film thickness is more than 1.5 μm, although the light-shielding property can be secured, the flatness of the color filter is easily sacrificed, and a step is easily generated. When a surface step is formed, 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 uneven or the cell gap varies. For example, the display quality of the liquid crystal display element is degraded. To reduce the surface step, it is effective to provide a transparent protective film on the colored layer, but it is disadvantageous in that the structure of the color filter becomes complicated and the manufacturing cost increases.

The light-shielding property of the resin black matrix is represented by an OD value (common logarithm of a 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, photosensitive or non-photosensitive materials such as epoxy resin, acrylic resin, urethane resin, polyester resin, polyimide resin and polyolefin resin are 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 of 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, and the like are 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 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 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 resin black matrix is formed as described above, unnecessary portions are removed by photolithography to form a desired first color pattern. Form.
In this case, the colored layer is left at least in the portion covering the opening of the resin black matrix and in the portion where the spacer is formed by the colored 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 coloring layer on the opening and the coloring layer forming the spacer may be continuous or separated. However, when the ITO film formed on the color filter is disconnected between the coloring layer and the spacer on the opening to prevent conduction between the color filter side and the counter substrate, the coloring layer and the spacer on the opening are formed. It is preferable that the color layer is separated and fractionated.

In the present invention, a spacer formed by laminating colored layers of three primary colors is formed on a resin black matrix, and the area and arrangement of the spacer are opposed to the color filter when a liquid crystal display device is manufactured. It is greatly affected by the structure of the active matrix substrate. Therefore, when there is no transparent electrode substrate side constraints facing, it is the area and location of the spacer is not particularly limited, considering the size of the pixel, the area per one spacer is 10μm ² ~1000μm ² Is preferred. If it is smaller than 10 μm ² , it is difficult to form and laminate a precise pattern, and if it is larger than 1000 μm ² , it will be difficult to completely dispose it on a black matrix depending on the shape of the spacer portion.

The thicknesses of the three primary colors are not particularly limited.
The thickness is preferably 1 to 3 μm per layer. In this case, the total thickness of the three primary color layers is 3 to 9 μm. When the total film pressure is less than 3 μm, a sufficient cell gap cannot be obtained. When the total film pressure exceeds 9 μm, uniform application of the colored layer becomes difficult, and furthermore, a transparent conductive film formed on the color filter is formed. Is undesirably reduced in reliability.

When the cell gap is maintained using the color filter of the present invention, for example, R,
When G and B are selected, the film thickness of G + B + Bk (resin black matrix) for R, and B + R for G
The film thickness of + Bk and the film thickness of R + G + Bk for B correspond to the cell gap in the liquid crystal display device.

In the present invention, in order to form the dot-shaped spacer by laminating the respective colored layers, the paint for forming the second and third layers is particularly required to have a certain level of viscosity and leveling resistance (for example, 1.0 × 10 ^−2). ~ 5 x 10 ^-4 Pa yield value).
This is to prevent the coating film serving as a spacer, which is applied on the base provided by the first layer and the 1 + 2 layer stacking, from becoming thinner than other portions due to leveling flowing into the peripheral portion. If sufficient leveling resistance cannot be ensured as a physical property of the paint from the viewpoint of the dispersibility of the pigment, etc., drying under reduced pressure is performed immediately after the application of the colored layer as a substitute or as a means to assist the loss of fluidity. At the very least, the coating liquid may be heated and cured using a uniform heating means such as a hot plate.

However, on the other hand, the use of a coating material having a high viscosity and which is difficult to level, or processing under conditions such as drying under reduced pressure to suppress the flow of the coating solution is because the film thickness pattern immediately after the application is directly inherited as the spacer height. In the case of adopting a method that has a certain tendency in non-uniform film thickness distribution, such as a spinner, where the center of rotation tends to be thick in principle in the formation of a coating film, two or four layers are laminated. This is particularly inconvenient because the non-uniformity is emphasized.
That is, it is considered that the height variation of the dot-like spacers on which the coloring layers are stacked is more emphasized than the height variation of the coloring layers in the color filter screen. Since the height of the dot spacer directly determines the cell gap, a larger variation in the height of the dot spacer is likely to significantly impair the display quality when the liquid crystal display device is used as a cell gap unevenness.

In order to avoid this cell gap unevenness, according to the present invention, the length H (ie, the normal direction) of the spacer composed of the black matrix and the three colored layers formed thereon over the color filter substrate plane is defined. Height of black matrix and three colored layers (total height of four layers in total))
Is 0.6 μm or less, and preferably 0.3 μm or less. Here, H is measured as a step from the glass substrate surface by a contact type such as a stylus type or a non-contact type surface shape measuring device such as a laser microscope. This is measured at each point in the color filter screen, and the in-plane variation is evaluated based on the difference between the maximum value and the minimum value. A liquid crystal display device using a color filter having such characteristics has no display unevenness due to cell gap unevenness.

In order to reduce the variation in the height of the spacer in the color filter screen as defined in the present invention,
As a means for applying the black matrix and each colored layer, of the above-mentioned applying means, a method such as a slit die coater, a bar coater, or a roll coater, which does not have a uniform tendency in terms of the nonuniformity of the film thickness in principle, is adopted. Then, as will be specifically shown in the following examples, although the unevenness of the thickness of each layer to be applied is unavoidable, the unevenness of the film thickness distribution in the case of one-layer coating is applied to the second and subsequent layers. By compensating for this, it can be made smaller than (single-layer coating film x number of stacked layers). This makes it possible to minimize the in-plane variation of the dot-like spacers formed by laminating colored layers of three primary colors on a part of the black matrix. As a result, a liquid crystal display element having a sufficient cell gap and providing good display characteristics while avoiding the possibility of a display defect (cell gap unevenness) due to variations in the height of the color filter spacer is provided. can do.

Next, a color liquid crystal display device manufactured using the above color filter and TFT substrate will be described. FIG. 2 schematically shows a cross-sectional view of a preferred specific example of the color liquid crystal display device. In FIG. 2, 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 held between the color filter and the transparent electrode substrate.
As shown in FIG. 1, the liquid crystal display device is manufactured with the above-mentioned color filter and the transparent electrode substrate facing each other. The color filter may be provided with a transparent protective film on the colored layer if necessary, but the configuration becomes complicated and the production cost increases. Further, the spacer height is reduced by the leveling property of the transparent protective film. Further, a transparent electrode such as an ITO film is formed on the 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 transparent substrate. On the transparent electrode substrate, in addition to the transparent electrode, a TFT element, a thin film diode (TFD) element, a scanning line, a signal line, and the like are provided, and a TFT liquid crystal display element and a TFD liquid crystal display element can be manufactured. A liquid crystal alignment film is provided on a color filter having a transparent electrode and a transparent electrode substrate,
An alignment process such as rubbing is performed. After the alignment treatment, the color filter and the transparent electrode substrate are attached to each other using a sealant, and after the liquid crystal is injected from an inlet provided in the seal portion, the inlet 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. A liquid crystal display element having no transparent electrode on the color filter side, for example, a method called in-plane switching (IPS) also has a configuration corresponding to this.

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 and the like, and is also suitably used for liquid crystal projection and the like.

[0047]

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 7,000 rpm for 30 minutes, and the glass beads were filtered to prepare a black paste.

Composition of 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

A black paste was applied to a 300 × 350 mm non-alkali glass (manufactured by NEC Corporation, OA-2) substrate using a spinner and semi-cured in an oven at 135 ° C. for 20 minutes. Subsequently, a positive resist (Sphipley "Microposit" RC100 30 cp) was applied with a spinner and dried at 90 ° C. for 10 minutes. The resist film thickness was 1.5 μm. Exposure machine P manufactured by Canon Inc.
Exposure was performed using a LA-501F through a photomask. This is a pattern in which a color filter on one surface where the center of the color filter overlaps the center of the glass substrate is designed.

Next, an aqueous solution containing 2% by weight of tetramethylammonium hydroxide at 23 ° C. was used as a developer.
The substrate was dipped in a developing solution, and simultaneously, the substrate was swung so as to make one reciprocation in a width of 10 cm in 5 seconds, thereby simultaneously developing the positive resist and etching the polyimide precursor. The development time was 60 seconds. After that, the positive resist was peeled off with methylcellosolve acetate, and further 30
After curing at 0 ° C. for 30 minutes, a resin black matrix substrate was obtained. The thickness of the resin black matrix is 0.9
0 μm, and the OD value was 3.0. The reflectance (Y value) at the interface between the resin black matrix and the glass substrate was 1.2%.

(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.

First, a blue paste was applied on a resin black matrix substrate and dried with hot air at 80 ° C. for 10 minutes.
Semi-cure at 20 ° C. for 20 minutes. Thereafter, a positive resist (Sphipley "Microposit" RC100 30 cp) was applied by a spinner and dried at 80 ° C. for 20 minutes. Exposure using a mask, alkaline developer (Sphipley "Microposit" 351)
The substrate was dipped, and the development of the positive resist and the etching of the polyimide precursor were simultaneously performed while simultaneously swinging the substrate. Thereafter, the positive resist was peeled off with methyl cellosolve acetate, and cured at 300 ° C. for 30 minutes. The thickness of the colored pixel portion was 2.0 μm.
By this patterning, the first step of the spacer was formed on the resin black matrix together with the formation of the blue pixel.

After washing with water, the second step of the spacer was similarly formed on the resin black matrix together with the formation of the red pixel. The thickness of the red pixel portion was 1.8 μm.

After further washing with water, the formation of green pixels and the formation of spacers 3 on the resin black matrix in the same manner.
Steps were formed to produce a color filter. The thickness of the green pixel portion was 1.9 μm.

The area of the spacer portion provided on the resin black matrix by the lamination of the colored layers was about 100 μm ² per piece. The height of the spacer (thickness of three colored layers on the resin black matrix) is 5.0 μm
Which is lower than the total thickness (5.7 μm) of each colored layer. The spacer was provided in the screen at a rate of one per pixel. In addition, spacers are provided on a part of the frame formed of a resin black matrix around the screen by color overlapping at the same density as in the screen.

FIG. 2 shows a film thickness profile of the black matrix and each colored layer before pattern processing. In this method, the step of each point on the diagonal line including the center portion of the color filter substrate from the glass substrate surface is measured with an FP-20 (surface shape measuring device manufactured by tencor), and the thickness of the coating film and the height of the dot spacer are measured. Plotted as Although the film thickness profile of each coating layer varies slightly in the plane, the tendency is not constant. Therefore, as shown in FIG. The range of the variation is smaller than four times the thickness variation of the single-layer solid film by complementing with the film layers. The variation in the color filter screen of the length of the in-plane black matrix and the dot-shaped spacer in the direction of the normal to the plane of the color filter substrate (total height of four layers, hereinafter may be referred to as “four color height”) H is 0.26 μm.

(3) Fabrication of color liquid crystal display element ITO was formed on the color filter by sputtering.
The film was formed as a mask. The thickness of the ITO film was 150 nm, and the surface resistance was 20 Ω / □. A polyimide-based alignment film was provided on the ITO film, and a rubbing treatment was performed.
On the other hand, a transparent electrode substrate provided with a TFT element was produced as follows.

First, a chromium film was formed on a transparent alkali-free glass substrate (OA-2, manufactured by NEC Corporation) by vacuum deposition, and the gate electrode was patterned by photoetching. Next, a silicon nitride film (SiNx) having a thickness of about 500 nm is formed by plasma CVD.
Was formed to form an insulating film. Subsequently, the amorphous silicon film (a-Si) and SiNx as an etching stopper film layer were patterned. At this time, the part in contact with the spacer was not etched, and the area per one was left as about 250 μm ² . Film formation and patterning of n + a-Si for obtaining an ohmic contact, and further, film formation and patterning of a transparent electrode (ITO) serving as a display electrode. Further, when aluminum as a wiring material is entirely deposited and a drain electrode and a source electrode are formed by a photo-etching method, the area of one piece of SiN having an area of about 250 μm ^{2 serving} as a part to be in contact with the above-described spacer is obtained.
The aluminum deposited on the exposed portion of x was removed by etching. Using the drain electrode and the source electrode as a mask, the n + a-Si in the channel portion is removed by etching, and the TFT is removed.
Was completed.

Finally, a polyimide alignment film was provided in the same manner as the color filter, and rubbing treatment was performed.

After a color filter provided with an alignment film and a transparent electrode substrate provided with a thin film transistor were bonded together using a sealant, liquid crystal was injected from an injection port provided in the seal portion. The liquid crystal was injected by leaving the empty cell under reduced pressure, immersing the injection port in the liquid crystal layer, and returning the pressure to normal pressure. After injecting the liquid crystal, the injection port was sealed, and a polarizing plate was attached to the outside of the substrate to produce a cell. The obtained liquid crystal display element had good display quality.

Comparative Example 1 A liquid crystal display device was manufactured in the same manner as in Example 1 except that a spinner was used instead of a slit die to coat each coating layer. At this time, the diagonal film thickness including the central portion of the color filter substrate shown in FIG. In connection with the physical properties of the coating solution, it can be seen that the central part peculiar to the spinner tends to become thicker in principle. Since the thickness profile of each coating layer has a certain tendency as described above, this tendency is further emphasized when four layers are laminated as shown in FIG. The height variation is large. The length of the dot-shaped spacer in the screen in the direction normal to the plane of the color filter substrate (4
(Color height) Color filter variation of H is 0.6
It was 5 μm. In the obtained liquid crystal display element, display unevenness due to cell gap unevenness was observed.

[0064]

According to the color filter of the present invention, a spacer formed by laminating colored layers is provided on a resin black matrix, and the dot-shaped spacers on the black matrix are directed in the direction normal to the plane of the color filter substrate. In-plane variation of length (4 colors height) H is 0.6μ
m or less.
The following effects can be obtained when a liquid crystal display element is manufactured using this.

(1) The spacer does not exist on the pixel portion, and the display quality is not deteriorated due to the scattering and transmission of light by the spacer, and the display quality contrast is particularly improved. (2) Since the spacer is in contact with the transparent electrode substrate facing the surface, the alignment film and the transparent electrode are less damaged and a display with less defects is obtained. (3) The step of dispersing the spacer is not required, and the manufacturing process of the liquid crystal display element is simplified. (4) It is not necessary to control the particle size distribution of the spacers with high precision, and the manufacture of the liquid crystal display device becomes easy. (5) Since the cell gap is maintained by the film thickness of the resin black matrix and the two colored layers, a liquid crystal display element having a sufficient cell gap can be obtained. (6) The spacer is provided on the black matrix, and the in-plane variation in the height of the dot spacer on the black matrix is small, so that a liquid crystal display device free from display unevenness due to cell gap unevenness can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a color liquid crystal display device using a color filter of the present invention.

FIG. 2 shows a black matrix of a color filter produced in Example 1 and a film thickness profile of a solid film of each colored layer.

FIG. 3 is a diagram showing a height distribution of a black matrix of a color filter and a dot spacer of a three-color coloring layer manufactured in Example 1.

FIG. 4 is a film thickness profile of a black matrix of a color filter produced in Comparative Example 1 and a solid film of each colored layer.

FIG. 5 is a diagram showing a height distribution of a dot matrix spacer of a black matrix + three-color coloring layer of a color filter produced in Comparative Example 1.

[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) 14 Chromium black matrix 15 Protective film

Claims (4)

[Claims] 1. A color filter comprising: a black matrix provided on a transparent substrate; and coloring layers of three primary colors provided so as to cover an opening of the black matrix and a part of the black matrix. A plurality of dot spacers formed by laminating three primary color layers are provided on a part of the black matrix, and (B) the color filter substrate plane of the black matrix and the dot spacers provided on the black matrix A variation in the color filter screen having a length H in the normal direction of 0.6 μm or less. 2. The color filter according to claim 1, wherein the transparent electrode layer is provided so as to be in direct contact with the colored layer. 3. The color filter according to claim 1, wherein each colored layer is made of polyimide. 4. A color liquid crystal display device comprising a pair of transparent substrates having transparent electrodes and a liquid crystal layer sandwiched between the two transparent substrates, wherein one of the substrates is one of claims 1 to 3. 13. A color liquid crystal display device, which is the color filter described in the above item.