JPH10104591A - Substrate for liquid crystal display device and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a display device which has an excellent display grade, substantially prevents the occurrence of problems, such as crosstalks, and has excellent reliability by using a substrate having spacers which are recessed in the sectional shapes of the uppermost layer and are fixed in non-display regions. SOLUTION: The substrate for the liquid crystal display device having the spacers 16 to 18 which are recessed in the sectional shapes of the uppermost layer in the non-display regions and are fixed is used. The spacers 16 to 18 come into contact with a counter substrate when the liquid crystal display device is manufactured. As a result, the specified gas is held with the counter substrate and liquid crystals are injected into this gap. The height (the height up to the vertex of the recessed shapes when the flat parts near the center of the spacers is determined as a reference) of the recessed shapes is 0.05 to 2μm. If the height is too low, the effect for preventing the display defect, etc., by the nonuniformity of the cell gap is not exhibited. If, conversely, the height is too large, there is a possibility that chipping is induced in the spacers by the load at the time of a rubbing treatment or at the time of assembling the panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for a liquid crystal display device having a spacer function and a liquid crystal display device manufactured using the same.

[0002]

2. Description of the Related Art In a conventional liquid crystal display device,
As shown in FIG. 1, in order to maintain the thickness of the liquid crystal layer (cell gap), generally, plastic beads, glass beads, or glass fibers are used as spacers between two substrates for a liquid crystal display device. I have. These spacers are arranged by scattering when assembling the liquid crystal display device.

In order to maintain a cell gap, Japanese Patent Application Laid-Open Nos. Sho 56-140324,
JP-A-4-93924 and JP-A-5-196946 include:
A liquid crystal display device using a structure in which colored layers forming a color filter are overlapped as a spacer has been proposed.

[0004]

In a liquid crystal display device in which plastic beads or the like are scattered as spacers, the positions of the spacers are not fixed, and the spacers also exist in the display area on the substrate. There is a problem that incident light is scattered by the spacers present in the display area, and the display quality of the liquid crystal display device is reduced.

[0005] The spacers to be sprayed are usually spherical or rod-shaped. Therefore, when a liquid crystal display device is manufactured, when the two substrates are crimped, the spacers come into contact with the substrate by dots or lines. Therefore, the alignment film and the transparent electrode on the substrate may be damaged, which may cause a display defect. Further, 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 may be reduced.

[0006] On the other hand, in a liquid crystal display device actually obtained by the disclosed technique using a structure in which colored layers forming a color filter are overlapped as a spacer, when the height of the spacer varies, the height of the spacer is increased. In some cases, the cell gap fluctuates in accordance with the fluctuation in the display quality, and the display quality deteriorates.

[0007] When one of the two substrates constituting the liquid crystal display device is a substrate having a conductive film on the surface of the spacer and the other is a substrate having a pattern electrode, between the pattern electrodes or between the substrates. In some cases, display failures such as crosstalk and switching failures may occur. In particular, when the displacement of the spacer formation position, the displacement of the size, and the displacement of the bonding position of the two substrates are large, there is a high possibility that this will cause a problem.

[0008] In view of the above problems, the present invention maintains a uniform cell gap in a screen and causes display defects such as crosstalk and switching failure even if there is some variation in spacer height. An object of the present invention is to provide a liquid crystal display device substrate which is difficult to obtain, and a liquid crystal display device using the same.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
A substrate for a liquid crystal display device having a fixed spacer in a non-display area in which the cross-sectional shape of the uppermost layer is concave, and at least one substrate having a fixed spacer in the non-display area, and an uppermost layer of the spacer Has a concave shape, or
This is achieved by a liquid crystal display device in which a liquid crystal layer is sandwiched between two substrates, which has a shape in which a concave is crushed.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below.

A liquid crystal display device is used for displaying images and characters, for information processing, and the like by using the electro-optical response of liquid crystal. Specifically, a personal computer, a word processor, a navigation system, a liquid crystal television, It is used for display screens such as video, liquid crystal projection, and the like.

The substrate for a liquid crystal display device of the present invention is used for a liquid crystal display device with or without electrodes and a liquid crystal alignment film, and is a substrate for sandwiching a liquid crystal layer. Specifically, a normal glass substrate, a plastic substrate, a thin film transistor (TF
T), Metal Insulator Metal (MIM),
A substrate having an active element such as a varistor or a diode, a color filter, and the like can be given, and a color filter is preferable from the viewpoint of easy formation of a spacer.

The color filter according to the present invention is a substrate having pixels formed of a colored layer that transmits light of any color. Usually, a pixel is composed of three primary colors of red, green and blue.

The coloring layer may be made of any material as long as impurities causing display defects do not elute in the liquid crystal. Specific examples of the material include an inorganic film whose film thickness is controlled to transmit only arbitrary light, and a colored resin film in which dyeing, dye dispersion, or pigment dispersion is performed. There is no particular limitation on the resin used as the colored resin film, and acrylic, polyvinyl alcohol, polyimide, or the like can be used. Note that it is preferable to use a pigment-dispersed resin film as the colored film from the viewpoints of simplicity of the manufacturing process and weather resistance. In particular, it is preferable to use a polyimide film in which a pigment is dispersed, since it has excellent heat resistance and chemical resistance as compared with other resins.

In the color filter according to the present invention,
It is desirable to arrange a black matrix between pixels. The black matrix is a light shielding film formed in a non-display portion between pixels. With the arrangement of the black matrix, it is possible to improve the contrast of the liquid crystal display device and prevent malfunction of a driving element of the liquid crystal display device due to light.

As the black matrix, usually C
Metal films such as r, Al, and Ni, and oxides and nitrides thereof, and resin films in which a light-blocking agent is dispersed in a resin are used. These black matrices are preferably used, but can be manufactured at low cost, and since low reflection is easy, use a black matrix composed of a resin film in which a black pigment or the like is dispersed in a resin such as polyimide. Is preferred.

The pigment used in the color filter of the present invention is not particularly limited, but a pigment having excellent light resistance, heat resistance and chemical resistance is desirable. Specific examples of typical pigments are indicated by color index (CI) numbers. Examples of yellow pigments include Pigment Yellow 20, 24, 83, 8
6, 93, 94, 109, 110, 117, 125, 1
37, 138, 139, 147, 148, 153, 15
4, 166, 173 and the like. Pigment oranges 13, 31, 36, 38, 4 are examples of orange pigments.
0, 42, 43, 51, 55, 59, 61, 64, 65
And the like. Examples of red pigments include Pigment Red 9, 97, 122, 123, 144, 149, 16
6, 168, 177, 180, 192, 215, 21
6, 224 and the like. Examples of purple pigments include Pigment Violet 19, 23, 29, 32, 33,
36, 37, 38 and the like. Examples of blue pigments include Pigment Blue 15 (15: 3, 15: 4, 1).
5: 6), 21, 22, 60, 64 and the like. Examples of green pigments include Pigment Green 7, 1
0, 36, 47 and the like. Pigment Black 7 and the like are examples of the black pigment. The present invention is not limited to these, and various pigments can be used alone or in combination. In addition, pigments that have been subjected to surface treatment such as rosin treatment, acid group treatment, and basic treatment may be used as necessary.

One of the methods of forming a polyimide film in which a pigment is dispersed in the present invention is a method of applying a polyamic acid solution in which a pigment is dispersed on a substrate. The polyamic acid contains a structural unit represented by the general formula (1) as a main component.

[0019]

Embedded image Here, n in the general formula (1) is 1-2. 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. However, the present invention is not limited to these. R ² is a divalent organic group having at least two carbon atoms. In terms of heat resistance, R
² is preferably a divalent group containing a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring and having 6 to 30 carbon atoms. R ²
Examples of phenyl group, biphenyl group, terphenyl group, naphthalene group, perylene group, diphenyl ether group, diphenyl sulfone group, diphenylpropane group,
Examples include, but are not limited to, benzophenone groups, biphenyltrifluoropropane groups, diphenylmethane groups, cyclohexylmethane groups, and the like. The polymer having the structural unit represented by the general formula (1) as a main component may be a copolymer in which R ¹ and R ² are each composed of one or two or more. There may be.

In order to improve the adhesive strength to the substrate, bis (3-aminopropyl) tetramethyldisiloxane having a siloxane structure may be copolymerized as a diamine component as long as the heat resistance is not reduced. Further, an anhydride such as maleic anhydride may be added as a blocking agent for the amine terminal after the polymerization of the polyimide precursor according to the terminal concentration and reacted. The higher the molecular weight, the better the mechanical properties of the polyimide film. For this reason, it is desired that the molecular weight of the polyimide precursor is also large. On the other hand, when performing pattern processing on a polyimide precursor by wet etching, if the molecular weight of the polyimide precursor is too large, there is a problem that the time required for development becomes too long. For this reason, it is usually desirable that the degree of polymerization be in the range of 5 to 1,000.

A colored film composed of a polyamic acid in which such a pigment is dispersed is subjected to a chemical treatment or a heat treatment to produce a polymer having an imide ring or another cyclic structure (polyimide,
(Polyamide imide), a pigment-dispersed polyimide film can be obtained. In addition, a polyimide film can be obtained from a polyamic acid ester or the like.

On the surface of the color filter, a transparent conductive film is formed as required. As the transparent conductive film, an excellent transparent conductive film which does not impair the suitability for color display is preferable. Specific examples of the transparent conductive film include tin oxide, tin-indium oxide (ITO), and antimony oxide, but are not particularly limited thereto. As a method for forming the transparent conductive film, dipping (D
Examples of the method include an ip) method, a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method, a vacuum deposition method, a sputtering method, and an ion plating method. As the transparent conductive film, from the viewpoint of transparency, conductivity, and ease of production, I
A TO sputtering film and an ion plating film are preferable.

The spacer in the present invention comes into contact with the opposite substrate as shown in FIG. 2 when the liquid crystal display device is manufactured. As a result, a certain gap is maintained with the counter substrate. Liquid crystal is injected into this gap.

The non-display area referred to in the present invention is an area which is always fixed in a bright or dark state when an image or a character is displayed, but is usually a dark state, that is, a light-shielded area.
Specific examples include a wiring portion of a TFT substrate, a black matrix formed on the wiring portion, and a black matrix of a color filter. The fixed spacer of the present invention is disposed in these light-shielded areas. If the spacer itself shows light-shielding properties,
It can be placed anywhere.

The spacer is formed by a method such as photolithography, printing, or electrodeposition. Since the spacer can be easily formed at the designed position and can be accurately arranged in a non-display area of the display section, for example, it is preferable to form the spacer by photolithography.

When the substrate for a liquid crystal display device is a color filter, the spacer is formed by any process such as during the process of forming the color filter or after a conductive film is formed on the surface of the color filter. Is also good.

There is no particular limitation on the material used for the spacer in the present invention, but when the substrate for a liquid crystal display device is a color filter, it is preferably formed of a color filter forming material for ease of manufacture.

The height of the spacer in the present invention is from 1 to
9 μm is preferable, 2 to 8 μm is more preferable, and 3 to
7 μm is preferred. If the height of the spacer is lower than 1 μm, it becomes difficult to secure a sufficient cell gap, and for example, in the TN mode, problems such as occurrence of disclination are likely to occur. On the other hand, if the thickness exceeds 9 μm, the cell gap of the liquid crystal display device becomes too large, and the voltage required for driving increases, which is not preferable. In addition,
Here, the height of the spacer refers to the distance between a flat portion of the display portion (a colored layer in the case of a color filter, and a transmissive electrode in the case of a TFT substrate) and the apex of the spacer. means. If there is unevenness in the height of the display portion flat portion on the substrate, it means the largest one of the distances between the top of the spacer and each display portion flat portion.

The concave shape of the cross section referred to in the present invention means that, as shown in a typical example in FIG. 3, a portion having a higher height at the peripheral portion than at a flat portion near the center. This is the shape of the cross section of the existing spacer (the plane perpendicular to the liquid crystal display element substrate).

By having the concave spacer according to the present invention, when the height varies as shown in FIG.
The concave shape of the spacer is crushed as shown in FIG. 5, the variation in height is reduced, and the cell gap is made uniform. On the other hand, when a spacer having a non-concave shape as shown in FIG. 6 is used, since the spacer does not collapse as shown in FIG. 7, the variation in height is not reduced, and the cell gap becomes non-uniform.
The display quality decreases. Further, by having the concave spacer, as shown in FIG. 8, it comes into contact with the opposing substrate at a point or a line, and the resistance value between the opposing pattern electrodes and between the substrates increases. Even when the concave spacer is crushed, the tip of the spacer is crushed to increase the resistance, and the resistance between the opposing pattern electrodes and between the substrates is increased. For this reason, the possibility of display failures such as crosstalk and switching failures is reduced. On the other hand, when a spacer having a non-concave shape is provided, as shown in FIG.
There is a case where the display comes into contact with the opposing substrate, the resistance value decreases, and display defects such as crosstalk and switching defects are induced.

The height of the concave shape of the cross section referred to in the present invention is
As shown in FIG. 10, this refers to the height to the top of the concave shape of the spacer with reference to the flat portion near the center of the spacer. The height of the concave shape is usually 0.05 to 2μ.
m, preferably 0.1 to 1 μm. If the height of the concave shape is too low, the effect of preventing display failure due to non-uniform cell gap and display failure due to crosstalk or switching failure cannot be exhibited. Conversely, if the height of the concave shape is too large, due to the load during rubbing and panel assembly,
The spacer may be chipped. When the spacer is chipped, the chipped fragments float in the liquid crystal, and the orientation of the liquid crystal is disturbed, which may cause display failure.

The spacer having a concave cross section is manufactured, for example, by the following method. A thermosetting resin film in which a black pigment is dispersed is formed on a substrate, and after pattern processing, thermosetting is performed to produce a black matrix.
Laminate a thermosetting resin film in which red pigment is dispersed, perform pattern processing, and, in addition to the display screen, form a protrusion made of a red pigment-dispersed resin film on a black matrix and heat-cure the resin. . Next, a thermosetting resin film in which a green pigment is dispersed is formed on the display screen by the same method, and at the same time, the thermosetting is performed by laminating the thermosetting resin film on the black matrix in the projection portion made of the red pigment-dispersed resin film. Then, the thermosetting resin film in which the blue pigment is dispersed is similarly laminated on the display screen portion and the projecting portion formed by superimposing the red and green pigment dispersed resin films on the black matrix, and thermosetting is performed. , Red, green, and blue, and a spacer fixed to the light shielding portion is formed. At this time, as the thermosetting resin film in which the blue pigment is dispersed, a material having appropriate thermomechanical properties is selected, and by appropriately setting the thermosetting temperature, for example, the glass transition temperature after curing of the resin is reduced. By thermosetting at a temperature not exceeding 30 ° C. or more, the cross section of the spacer can be made concave. When thermosetting at a temperature not exceeding a glass transition temperature of 30 ° C. or more, the cross-sectional shape of the pattern can be made concave by curing shrinkage of the resin. On the other hand, when thermosetting at a temperature exceeding the glass transition temperature by 30 ° C. or more,
The ends of the cured shrinkage pattern are smoothed by the flow of the resin, and the cross-sectional shape of the pattern is not concave. The order of forming the colored film is not limited to the above order of red, green, and blue,
Any order may be used, but care must be taken in setting the temperature at which the last laminated film is thermally cured. The present invention is not limited to the above method, and any method can be adopted as long as a spacer having a concave cross section can be formed.

[0033]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 (Preparation of color filter) In a 5000 ml four-necked flask equipped with a thermometer, a dry nitrogen inlet, and a stirrer, 4,4'-diaminodiphenyl ether (140.2) was added.
g (0.7 molar equivalent), 62.1 g (0.25 molar equivalent) of 3,3'-diaminodiphenylsulfone, bis-3-
12.4 g of (aminopropyl) tetramethylsiloxane
(0.05 molar equivalent), γ-butyrolactone 1000
g, 500 g of N-methyl-2-pyrrolidone,
After stirring at 40 ° C for 1 hour under dry nitrogen flow,
', 4,4'-benzophenonetetracarboxylic dianhydride 322.2 g (1 molar equivalent), γ-butyrolactone 9
45.9 g of the mixture was charged, and the mixture was stirred at 60 ° C. for 3 hours under a dry nitrogen flow to obtain a polyamic acid solution (polymer concentration: 18% by weight).

200 g of the polyamic acid solution was taken out, and 186 g of γ-butyrolactone and 64 g of butyl cellosolve were added to obtain a polyamic acid solution having a polymer concentration of 8% by weight.

4 g of Pigment Black 7 (carbon black), 40 g of N-methyl-2-pyrrolidone and 6 g of butyl cellosolve were dispersed together with 100 g of glass beads using a homogenizer at 7000 rpm for 30 minutes, and the glass beads were removed by filtration. An 8% by weight pigment dispersion was obtained.

To 30 g of the pigment dispersion, 30 g of the above-mentioned polyamic acid solution having a polymer concentration of 8% by weight was added and mixed to prepare a black paste. This paste was applied on a non-alkali glass substrate and prebaked at 120 ° C. to form a polyimide precursor black colored film. After cooling, a positive photoresist was applied and dried by heating at 90 ° C. to form a photoresist film. This was exposed through a photomask using an ultraviolet exposure machine. After the exposure, the film was immersed in an alkaline developer, and the development of the photoresist and the etching of the polyimide precursor black colored film were simultaneously performed to form openings. After the etching, the unnecessary photoresist layer was peeled off with methyl cellosolve acetate. The etched polyimide precursor black colored film was heated to 290 ° C. and thermally cured to be converted to polyimide to form a resin black matrix.

4 g of Pigment Red 177 (anthraquinone red), 40 g of γ-butyrolactone and 6 g of butyl cellosolve were dispersed in a homogenizer together with 100 g of glass beads at 7000 rpm for 30 minutes, and the glass beads were removed by filtration. A pigment dispersion was obtained.

To 30 g of the pigment dispersion, 30 g of the above polyamic acid solution having a polymer concentration of 8% by weight was added and mixed to obtain a red paste.

A red paste was applied on the resin black matrix and prebaked to form a polyimide precursor red colored film. Using a photoresist, by the same means as described above, the first step of the spacer is formed on the resin black matrix of the display screen portion, the frame, and the sealing portion around the frame, together with the formation of the red pixel, and heated to 290 ° C. And heat cured.

Pigment Green 7 (phthalocyanine green) (3.6 g), Pigment Yellow 83 (benzidine yellow) 0.4 g, γ-butyrolactone (32 g), and butyl cellosolve (4 g) were dispersed together with glass beads (120 g) at 7000 rpm for 30 minutes using a homogenizer. The beads were removed by filtration and a pigment concentration of 10
% By weight of the pigment dispersion was obtained.

To 32 g of the pigment dispersion, 28 g of the above polyamic acid solution having a polymer concentration of 8% by weight was added and mixed to obtain a green color paste.

In the same manner as when the red paste is used, the green pixel is formed, and the second step of the spacer is formed on the red laminated film on the resin black matrix of the display screen, the frame, and the seal around the frame. Was formed and heated to 290 ° C. for thermosetting.

60 g of the above-mentioned polyamic acid solution having a polymer concentration of 8% by weight, 2.8 g of Pigment Blue 15 (phthalocyanine blue), N-methyl-2-pyrrolidone 3
0 g, butyl cellosolve 10 g and glass beads 150 g
Together with a homogenizer at 7000 rpm for 30 minutes.
After the dispersion treatment for one minute, the glass beads were removed by filtration to obtain a blue color paste.

According to the same procedure as described above, the third step of the spacer is formed on the red and green laminated films on the resin black matrix of the display screen portion, the frame, and the sealing portion around the frame along with the formation of the blue pixel. 290 ° C. to perform heat curing.

The glass transition temperature after curing of the blue color paste was determined by differential scanning calorimetry.
290 ° C. Therefore, the difference between the thermosetting temperature and the glass transition temperature is within 30 ° C.

On a non-alkali glass substrate having this light-shielding layer, a red pixel, a green pixel, and a blue pixel, and a spacer on a resin black matrix of a display screen portion, a frame, and a sealing portion around the frame, a sputtering method is used. IT
An O layer was formed to obtain a color filter used as a substrate for a liquid crystal display device.

(Confirmation of Shape) The shape of one spacer (4 μm in height) on the color filter was observed and measured. The observation and measurement were performed using an optical microscope, a stylus type surface roughness measuring instrument, and a scanning electron microscope. First, when the uppermost layer of the spacer was observed with an optical microscope, it was found to be concave. Next, a surface roughness measuring instrument (SE from Kosaka Laboratory)
Using a -3300 stylus tip radius of 0.3 μm), the height of the concave protrusion in the cross section was measured to be 0.5 μm. When further observed using a scanning electron microscope,
As in the case of the surface roughness measuring device, the height of the concave projections in the cross section is set to 0.
It was 3 μm.

(Preparation and Evaluation of Color Liquid Crystal Display Device) A polyimide-based alignment film was provided on the ITO film of the color filter provided with the spacer, and rubbing treatment was performed. Similarly, a facing liquid crystal display substrate was also provided with a polyimide-based alignment film and subjected to a rubbing treatment. After bonding the two substrates together using an epoxy adhesive as a sealant, liquid crystal was injected from an injection port provided in the seal portion. After injecting the liquid crystal, seal the injection port,
Further, a polarizing plate was attached to the outside of the substrate to produce a liquid crystal display device.

No display failure such as crosstalk or switching failure occurred in this liquid crystal display device. In addition, display quality did not deteriorate due to display unevenness.

When this display device was disassembled and the spacer was observed, it was possible to confirm a portion where the concave shape was crushed and a portion where the concave shape was not crushed.

COMPARATIVE EXAMPLE 1 (Preparation of Color Filter) The thermosetting of the blue color paste forming the third step of the spacer was performed at 33 ° instead of 290 ° C.
A color filter was prepared in the same manner as in Example 1, except that the temperature was 0 ° C.

Since the glass transition temperature of the blue color paste after curing was 290 ° C., the heat curing temperature exceeded the glass transition temperature by 30 ° C. or more.

(Confirmation of Shape) Observation and measurement of the shape of one spacer (4 μm in height) on the color filter were performed in the same manner as in Example 1. Observation of the uppermost layer of the spacer with an optical microscope revealed that the spacer had a trapezoidal structure with rounded ends and a non-concave cross section.

Observation was performed using a surface roughness measuring instrument and a scanning electron microscope, and it was confirmed that the cross-sectional shape of the uppermost layer of the spacer was not concave.

(Production and Evaluation of Color Liquid Crystal Display Device) A liquid crystal display device was produced in the same manner as in Example 1. When this liquid crystal display device was driven, display defects such as crosstalk and switching defects occurred. In addition, display quality was deteriorated due to display unevenness.

Example 2 (Preparation of Color Filter) In a 5000 ml four-necked flask equipped with a thermometer, a dry nitrogen inlet, and a stirrer, 130.1 of 4,4'-diaminodiphenyl ether was added.
g (0.65 molar equivalent), 60.1 g (0.3 molar equivalent) of 3,4'-diaminodiphenyl ether, bis-3-
12.4 g of (aminopropyl) tetramethylsiloxane
(0.05 molar equivalent), γ-butyrolactone 1000
g, 400 g of N-methyl-2-pyrrolidone,
After stirring at 30 ° C. for 1 hour under a dry nitrogen flow, 3,3
', 4,4'-benzophenonetetracarboxylic dianhydride 161.1 g (0.5 molar equivalent), 3,3', 4,4
'-Biphenyltetracarboxylic dianhydride 144.2 g
(0.49 molar equivalents), γ-butyrolactone 127
6.8 g was added thereto, and the mixture was stirred at 70 ° C. for 2 hours under a flow of dry nitrogen. Thereafter, 1.96 g (0.02 g) of maleic anhydride was added.
(Molar equivalent) and stirred for 1 hour to obtain a polyamic acid solution (polymer concentration: 16% by weight). Add this solution to 200
Then, 160 g of γ-butyrolactone and 40 g of butyl cellosolve were added to obtain a solution having a polymer concentration of 8% by weight.

Using this polyamic acid solution, black, red, green and blue pastes were prepared, and the thermosetting temperature of the red paste forming the third step of the spacer was adjusted to 2
The temperature is set to 280 ° C. instead of 90 ° C. The order of forming the colored layers is not red, green, and blue, but blue, green,
A color filter was produced in the same manner as in Example 1 except that the color filters were arranged in the order of red. When the glass transition temperature of the red color paste after curing was measured in the same manner as in Example 1, it was 270 ° C. Therefore, the difference between the thermosetting temperature and the glass transition temperature is within 30 ° C.

(Confirmation of Shape) As in Example 1, the shape of one spacer (7 μm in height) on the color filter was observed and measured. When the uppermost layer of the spacer was observed with an optical microscope, it was concave. Next, when the height of the concave projections in the cross section was measured using a surface roughness measuring instrument, it was 0.6 μm. Further, when observed using a scanning electron microscope, the height of the concave projections in the cross section was 0.6 μm as in the case of the surface roughness measuring instrument.

(Production and Evaluation of Color Liquid Crystal Display Device) A liquid crystal display device was produced in the same manner as in Example 1. No display failure such as crosstalk or switching failure occurred in this liquid crystal display device. In addition, display quality did not decrease due to display unevenness.

When this display device was disassembled and the spacer was observed, it was confirmed that the concave portion was crushed and that the concave portion was not crushed.

Comparative Example 2 (Preparation of Color Filter) A color filter was prepared in the same manner as in Example 2 except that the resin was cured at 320 ° C. instead of 280 ° C. Since the glass transition temperature of the red color paste after curing was 270 ° C., the thermosetting temperature exceeded the glass transition temperature by 30 ° C. or more.

(Confirmation of Shape) The observation and measurement of the shape of one spacer (height: 7 μm) on the color filter were performed in the same manner as in Example 1. Observation of the uppermost layer of the spacer with an optical microscope revealed that the spacer had a trapezoidal structure with rounded ends and a non-concave cross section.

Observation using a surface roughness measuring instrument and a scanning electron microscope confirmed that the sectional shape of the uppermost layer of the spacer was not concave.

(Production and Evaluation of Color Liquid Crystal Display Device) A liquid crystal display device was produced in the same manner as in Example 1. When this liquid crystal display device was driven, display defects such as crosstalk and switching defects occurred. In addition, display quality was deteriorated due to display unevenness.

[0066]

The substrate for a liquid crystal display device of the present invention has a spacer fixed in a non-display area during display, and the uppermost layer of the spacer has a concave cross section.
The following effects can be obtained when a liquid crystal display device is manufactured using this.

(1) Even if there is some variation in the height of the spacer, a liquid crystal display device having a uniform cell gap in the screen can be obtained.

(2) Display defects such as crosstalk and switching defects due to conduction between the liquid crystal display substrate and the electrodes in the substrate via the spacers are reduced, and as a result, the liquid crystal display device with good display quality Increases the production yield.

[Brief description of the drawings]

FIG. 1 is a schematic view of a color liquid crystal display device using a conventional bead-shaped spacer.

FIG. 2 is a schematic view of a color liquid crystal display device using a color filter formed with a concave spacer obtained by the present invention.

FIG. 3 is a schematic view of a spacer in which the cross-sectional shape of the uppermost layer is concave.

FIG. 4 is a schematic diagram of a liquid crystal display device when the height of a concave spacer varies.

FIG. 5 is a schematic view showing the concave shape of the uppermost layer of the spacer and its collapse when a liquid crystal display device is manufactured.

FIG. 6 is a schematic view of an example of a spacer in which the cross-sectional shape of the uppermost layer is not concave.

FIG. 7 is a schematic diagram of a liquid crystal display device when the height of a non-concave spacer varies.

FIG. 8 is a schematic diagram when a liquid crystal display device is manufactured using a liquid crystal display device substrate having a concave spacer.

FIG. 9 is a schematic diagram when a liquid crystal display device is manufactured using a liquid crystal display device substrate having a non-concave spacer.

FIG. 10 is a schematic view showing a concave height.

[Explanation of symbols]

 1: transparent substrate 2: gate electrode 3: insulating film 4: pixel electrode 5: TFT 6: alignment film 7: liquid crystal 8: ITO 9: coloring layer 10: coloring layer 11: coloring layer 12: black matrix 13: transparent substrate 14 : Overcoat 15: bead spacer 16: spacer 17: spacer 18: spacer 19: spacer top layer 20: layer other than the top layer forming spacer 21: substrate 22: pattern electrode 23: conductive film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Shinichi Yamada 1-1-1, Sonoyama, Otsu, Shiga Prefecture Toray Industries, Inc. Shiga Plant (72) Inventor: Tetsuya Goto 1-1-1, Sonoyama, Otsu, Shiga Prefecture No. Toray Industries, Inc. Shiga Plant

Claims (13)

[Claims] 1. A substrate for a liquid crystal display device having a fixed spacer having a concave cross section of an uppermost layer in a non-display area. 2. The height of the concave projection of the cross section is 0.05 to 2 μm.
The liquid crystal display device substrate according to claim 1, wherein m is m. 3. The substrate for a liquid crystal display device according to claim 1, wherein the substrate has a conductive film on the side of the surface on which the spacers are formed. 4. A substrate for a liquid crystal display device according to claim 1, wherein the substrate is a color filter having pixels containing a colorant. 5. The substrate for a liquid crystal display device according to claim 1, wherein the spacer is made of a single color or a color overlap of a resin containing a colorant. 6. The liquid crystal display substrate according to claim 5, wherein the resin containing the colorant is polyimide. 7. The height of the formed spacer is 1 to 9 μm.
2. The substrate for a liquid crystal display device according to claim 1, wherein: 8. The substrate for a liquid crystal display device according to claim 7, wherein the spacer is made of a single color or a color overlap of a resin containing a colorant. 9. The substrate for a liquid crystal display device according to claim 8, wherein the resin containing the colorant is polyimide. 10. In a liquid crystal display device in which a liquid crystal layer is sandwiched between two substrates, at least one of the substrates has a fixed spacer in a non-display area, and the uppermost layer of the spacer has a concave shape, or A liquid crystal display device having a shape in which a concave is crushed. 11. The liquid crystal display device according to claim 10, wherein a conductive film is provided on a surface of at least one substrate on a liquid crystal layer side. 12. A color liquid crystal display device in which a liquid crystal layer is sandwiched between two substrates, wherein at least one of the substrates has a fixed spacer formed of a color overlap of a resin containing a colorant in a non-display area, A liquid crystal display device wherein the uppermost layer of the spacer has a concave shape or a concave shape. 13. The liquid crystal display device according to claim 12, wherein the resin containing the colorant is polyimide.