JP3458620B2 - Liquid crystal display device substrate and liquid crystal display device - Google Patents

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 by using the substrate.

[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 (cell gap) of the liquid crystal layer, plastic beads, glass beads, or glass fibers are generally used as spacers between two liquid crystal display device substrates. There is. These spacers are arranged by spraying when assembling the liquid crystal display device.

Further, in order to maintain the cell gap, JP-A-56-140324, JP-A-63-824054,
JP-A-4-93924 and JP-A-5-196946 disclose
A liquid crystal display device has been proposed in which a structure in which colored layers forming a color filter are stacked is used as a spacer.

[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. Incident light is scattered by the spacers existing in the display area, which causes a problem that the display quality of the liquid crystal display device is degraded.

Further, the spacers to be sprayed are usually in the shape of a sphere or a rod. Therefore, when manufacturing the liquid crystal display device, when the two substrates are pressure-bonded, the spacers come into contact with the substrates 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 damage of the alignment film and the transparent electrode may contaminate the liquid crystal and reduce the effective voltage applied to the liquid crystal.

On the other hand, in the liquid crystal display device actually obtained by the above-mentioned disclosed technique, in which the structure in which the colored layers forming the color filter are overlapped is used as the spacer, when the height of the spacer varies, the height of the spacer increases. The cell gap may fluctuate depending on the fluctuation of the thickness, and the display quality may be degraded.

When one of the two substrates constituting the liquid crystal display device has a conductive film on the spacer surface and the other has a pattern electrode, the space between the pattern electrodes or the space between the substrates is large. In some cases, a short circuit occurred in the display, and display defects such as crosstalk and switching defects occurred. In particular, when the spacer formation position deviation, the size deviation, the bonding position deviation of the two substrates, and the like are large, there is a great possibility of causing a problem.

In view of the above problems, the present invention maintains a uniform cell gap in the screen even if there is some variation in the height of the spacer, and causes display defects such as crosstalk and switching defects. A substrate for a liquid crystal display device that is difficult to provide, and a liquid crystal display device using the same.

[0009]

The object of the present invention is as follows.
A substrate for a liquid crystal display device having a fixed spacer in the non-display area in which the sectional shape of the uppermost layer is concave, and at least one substrate having the fixed spacer in the non-display area, and the uppermost layer of the spacer Is 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 is characterized in that the recess has a crushed shape.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

The liquid crystal display device is used for displaying images and characters, processing information, etc. by using the electro-optical response of liquid crystal, and specifically, a personal computer, a word processor, a navigation system, a liquid crystal television, It is used for display screens such as videos and liquid crystal projections.

The substrate for a liquid crystal display device of the present invention is a substrate for holding a liquid crystal layer, which is used in a liquid crystal display device with or without an electrode and a liquid crystal alignment film. Specifically, ordinary glass substrates, plastic substrates, thin film transistors (TF)
T), metal insulator metal (MIM),
Examples include a substrate having an active element such as a varistor and a diode, a color filter, and the like, and the color filter is preferable from the viewpoint of ease of forming a spacer.

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

The colored layer may be made of any material as long as it does not elute impurities causing defective display in the liquid crystal. Specific materials include an inorganic film whose film thickness is controlled so as to transmit only arbitrary light, and a colored resin film which is dyed, dye-dispersed or pigment-dispersed. The resin used as the colored resin film is not particularly limited, and acryl, polyvinyl alcohol, polyimide or the like can be used. 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 pigment-dispersed polyimide film because it is superior in heat resistance and chemical resistance to other resins.

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

The black matrix is usually C
A film of a metal such as r, Al, Ni, or an oxide or nitride thereof, or a resin film in which a light shielding agent is dispersed in a resin is used. Any of these black matrices is preferably used, but since it can be manufactured at low cost and can easily achieve low reflection, 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 used. It is preferable.

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 shown by color index (CI) numbers. Examples of yellow pigments are 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. Examples of orange pigments are Pigment Orange 13, 31, 36, 38, 4
0, 42, 43, 51, 55, 59, 61, 64, 65
And so on. 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 the purple pigment 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. Pigment Green 7 and 1 are examples of green pigments.
0, 36, 47 and the like. Examples of black pigments include Pigment Black 7. In the present invention, the pigments are not limited to these, and various pigments can be used alone or in combination. The pigment may be subjected to surface treatment such as rosin treatment, acidic group treatment, and basic treatment, if necessary.

In the present invention, one of the methods for forming a polyimide film in which a pigment is dispersed is to apply a polyamic acid solution in which a pigment is dispersed onto a substrate. The polyamic acid has a structural unit represented by the general formula (1) as a main component.

[0019]

[Chemical 1] Here, n in the general formula (1) is 1 to 2. R ¹ is a trivalent or tetravalent organic group having at least 2 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 heterocycle and having 6 to 30 carbon atoms. Examples of R ¹ include phenyl group, biphenyl group, terphenyl group, naphthalene group, perylene group, diphenyl ether group, diphenylsulfone group, diphenylpropane group, benzophenone group, biphenyltrifluoropropane group, cyclobutyl group, cyclopentyl group, and the like. However, the present invention is not limited to these. R ² is a divalent organic group having at least 2 carbon atoms. R in terms of heat resistance
² is preferably a divalent group containing a cyclic hydrocarbon, an aromatic ring or an aromatic heterocycle 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, diphenyl propane group,
Examples thereof include a benzophenone group, a biphenyltrifluoropropane group, a diphenylmethane group and a cyclohexylmethane group, but are not limited thereto. The polymer having the structural unit represented by the general formula (1) as a main component may have ^one of R ¹ and R ² each, or a copolymer of two or more types. It may be.

In order to improve the adhesive strength with the substrate, bis (3-aminopropyl) tetramethyldisiloxane having a siloxane structure may be copolymerized as a diamine component within the range of not lowering the heat resistance. In addition, an anhydride such as maleic anhydride may be added as a blocking agent for the amine terminal, depending on the terminal concentration, after the completion of the polymerization of the polyimide precursor, and reacted. The higher the molecular weight, the better the mechanical properties of the polyimide film. Therefore, it is desired that the molecular weight of the polyimide precursor is also large. On the other hand, when the polyimide precursor is subjected to pattern processing 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. Therefore, it is usually desirable that the degree of polymerization is in the range of 5 to 1000.

A polymer (polyimide, polyimide, etc.) having an imide ring or other cyclic structure is obtained by chemically or heat treating a colored film made of polyamic acid in which such a pigment is dispersed.
Polyamideimide) gives a pigment-dispersed polyimide film. In addition, a polyimide film can be obtained from polyamic acid ester or the like.

A transparent conductive film is formed on the surface of the color filter, if necessary. As the transparent conductive film, those having high transparency and not impairing the color display suitability are preferable. Specific examples of the transparent conductive film include, but are not limited to, tin oxide, tin oxide-indium (ITO), and antimony oxide. As a method of forming the transparent conductive film, dipping (D
ip) method, chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, vacuum deposition method, sputtering method, ion plating method and the like. As the transparent conductive film, in terms of transparency, conductivity, and ease of manufacturing, I
A TO sputtering film and an ion plating film are preferable.

The spacer in the present invention comes into contact with the counter substrate as shown in FIG. 2 when the liquid crystal display device is manufactured. As a result, a constant gap is maintained between the counter substrate and 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 displaying an image or a character, but is usually a dark state, that is, a light-shielded area.
Specific examples thereof include the wiring portion of the TFT substrate, the black matrix formed on the wiring portion, the black matrix of the color filter, and the like. The fixed spacers of the present invention are placed in these light shielded areas. If the spacer itself has a light-shielding property,
It can be placed anywhere.

The spacers are formed by a method such as photolithography, printing or electrodeposition. It is preferable to form the spacers by photolithography, because the spacers can be easily formed at the designed positions and can be accurately arranged in the non-display region of the display unit, for example.

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

The material used for the spacer in the present invention is not particularly limited, but when the liquid crystal display device substrate is a color filter, it is preferably formed of a color filter forming material from the viewpoint of easy production.

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

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

By having the concave spacers in the present invention, as shown in FIG.
The concave shape of the spacer is crushed as shown in FIG. 5, the height variation is reduced, and the cell gap is made uniform. On the other hand, when the spacer having a non-concave shape as shown in FIG. 6 is not crushed as shown in FIG. 7, variation in height is not reduced and the cell gap becomes non-uniform.
The display quality is degraded. Further, by having the concave spacers, as shown in FIG. 8, the substrates come into contact with the opposing substrates at points or lines, 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. Therefore, the possibility of display defects such as crosstalk and switching defects is reduced. On the other hand, in the case of having a spacer that is not concave, as shown in FIG.
There is a case in which a display substrate such as a crosstalk or a switching defect is induced because the resistance value is lowered due to the surface contact with the opposing substrate.

In the present invention, the height of the concave shape of the cross section means
As shown in FIG. 10, it refers to the height to the apex 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 2 μ.
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 nonuniform cell gap and display failure due to crosstalk or switching failure cannot be exerted. On the contrary, if the height of the concave shape is too large, the load during rubbing and panel assembly may cause
The spacer may be chipped. When the spacer is chipped, the chipped chip may float in the liquid crystal, disturbing the alignment of the liquid crystal and inducing display defects in some cases.

The spacer having a concave cross section is produced, for example, by the following method. A thermosetting resin coating in which a black pigment is dispersed is formed on a substrate, and after pattern processing, heat curing is performed to produce a black matrix.
Laminate a thermosetting resin coating in which red pigment is dispersed, perform pattern processing, and form a protrusion consisting of a red pigment-dispersed resin coating on the black matrix in addition to the display screen, and heat cure the resin. . Next, a thermosetting resin film in which a green pigment is dispersed is formed on the display screen portion by the same method, and at the same time, the thermosetting resin film is laminated on the projection portion formed of the red pigment-dispersed resin film on the black matrix and thermoset. Then, the thermosetting resin coating in which the blue pigment is dispersed is similarly laminated on the projection portion formed by superimposing the red and green pigment-dispersed resin coating on the display screen portion and the black matrix to perform thermosetting. A spacer fixed to the light-shielding portion is formed by overlapping the colors of red, green, and blue. At this time, as the thermosetting resin coating in which the blue pigment is dispersed, one having appropriate thermomechanical properties is selected, and the thermosetting temperature is appropriately set to, for example, change the glass transition temperature after curing of the resin. By heat-curing at a temperature not exceeding 30 ° C. or more, the spacer can have a concave cross section. When the resin is heat-cured at a temperature not exceeding the glass transition temperature of 30 ° C. or higher, it is possible to make the cross-sectional shape of the pattern concave due to curing shrinkage of the resin. On the other hand, when thermosetting at a temperature higher than the glass transition temperature of 30 ° C. or higher,
The end portion of the pattern which has been cured and contracted is 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 order of red, green and blue described above,
Any order may be used, but at that time, attention must be paid to the temperature setting for thermosetting the final laminated film. The present invention is not limited to the above method, and any method can be adopted as long as the spacer having a concave cross section can be formed.

[0033]

EXAMPLES The present invention will now be described in detail with reference to Examples, but the present invention is not limited thereto.

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

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

Pigment Black 7 (carbon black) 4 g, N-methyl-2-pyrrolidone 40 g, and butyl cellosolve 6 g were dispersed together with 100 g of glass beads using a homogenizer at 7,000 rpm for 30 minutes, and the glass beads were removed by filtration to obtain a pigment concentration. An 8% by weight pigment dispersion was obtained.

30 g of the polyamic acid solution having a polymer concentration of 8% by weight was added to and mixed with 30 g of the pigment dispersion liquid to prepare a black paste. After applying this paste on a non-alkali glass substrate, prebaking was performed at 120 ° C. to form a polyimide precursor black colored film. After cooling, a positive photoresist was applied and heated and dried at 90 ° C. to form a photoresist film. This was exposed through a photomask using an ultraviolet exposure device. After the exposure, the substrate was dipped in an alkali developing solution, the photoresist was developed, and the polyimide precursor black colored film was simultaneously etched to form an opening. After etching, the unnecessary photoresist layer was peeled off with methyl cellosolve acetate. The etched polyimide precursor black colored film was heated to 290 ° C. to be thermally cured and converted into polyimide to form a resin black matrix.

Pigment Red 177 (Anthraquinone Red) 4 g, γ-butyrolactone 40 g, and butyl cellosolve 6 g were dispersed together with 100 g of glass beads using a homogenizer at 7,000 rpm for 30 minutes, and the glass beads were removed by filtration to obtain a pigment concentration of 8% by weight. A pigment dispersion was obtained.

30 g of the polyamic acid solution having a polymer concentration of 8% by weight was added to and mixed with 30 g of the pigment dispersion liquid 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 above, along with the formation of the red pixel, the first step of the spacer is formed on the resin black matrix of the display screen portion, the frame, and the seal portion around the frame, 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 together with 120 g of glass beads were dispersed with glass homogenizer at 7,000 rpm for 30 minutes, and then glass. The beads are removed by filtration and the pigment concentration is 10
A weight% pigment dispersion was obtained.

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

Similarly to the case of using the red paste, the second stage of the spacer is formed on the red laminated film on the resin black matrix of the display screen portion, the frame, and the seal portion around the frame in the same manner as the formation of the green pixel. Was formed and was heated to 290 ° C. to be heat-cured.

60 g of the above polyamic acid solution having a polymer concentration of 8% by weight, Pigment Blue 15 (phthalocyanine blue) 2.8 g, N-methyl-2-pyrrolidone 3
0 g, butyl cellosolve 10 g, glass beads 150 g
With a homogenizer at 7,000 rpm
After the dispersion treatment for minutes, the glass beads were removed by filtration to obtain a blue color paste.

By 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 seal portion around the frame, together with the formation of the blue pixel. It was heated to 290 ° C. and heat-cured.

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

A non-alkali glass substrate having the light-shielding layer, red pixels, green pixels, and blue pixels, and a spacer on the resin black matrix of the display screen portion, the frame, and the seal portion around the frame is sputtered. 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 (height: 4 μm) on the color filter was observed and measured. The observation and measurement were performed using an optical microscope, a stylus type surface roughness measuring device, and a scanning electron microscope. First, when the uppermost layer of the spacer was observed with an optical microscope, it was concave. Next, a surface roughness measuring device (SE manufactured by Kosaka Laboratory
Using a -3300 stylus tip radius of 0.3 μm), the height of the concave protrusion in the cross section was measured and found to be 0.5 μm. Furthermore, when observing with a scanning electron microscope,
Similar to the surface roughness measuring machine, the height of the concave protrusions in the cross section is 0.
It was 3 μm.

(Production 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 this spacer, and a rubbing treatment was performed. Similarly, the liquid crystal display substrate facing each other was also provided with a polyimide-based alignment film and rubbed. After these two substrates were bonded together using an epoxy adhesive as a sealant, liquid crystal was injected through the injection port provided in the seal portion. After injecting liquid crystal, seal the inlet,
Further, a polarizing plate was attached to the outside of the substrate to manufacture a liquid crystal display device.

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

When this display device was disassembled and the spacers were observed, it was possible to confirm that the concave portions were crushed and that the concave portions were not crushed.

Comparative Example 1 (Preparation of Color Filter) The blue color paste forming the third stage of the spacer was thermally cured at 290 ° C. instead of 33 ° C.
A color filter was produced in the same manner as in Example 1 except that the color filter was used at 0 ° C.

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

(Confirmation of Shape) The shape and shape of one spacer (height: 4 μm) on the color filter was observed and measured in the same manner as in Example 1. When the uppermost layer of the spacer was observed with an optical microscope, the structure was a trapezoidal shape with rounded ends, and the cross-sectional shape was not concave.

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

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

Example 2 (Production of color filter) 4,4'-diaminodiphenyl ether 130.1 was placed in a 5000 ml four-necked flask equipped with a thermometer, a dry nitrogen inlet and a stirrer.
g (0.65 molar equivalent), 3,4'-diaminodiphenyl ether 60.1 g (0.3 molar equivalent), bis-3-
(Aminopropyl) tetramethylsiloxane 12.4 g
(0.05 molar equivalent), γ-butyrolactone 1000
g, N-methyl-2-pyrrolidone 400g,
After stirring for 1 hour at 30 ° C. under a flow of dry nitrogen,
161.1 g (0.5 molar equivalent) of 3,4'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4
′ -Biphenyltetracarboxylic dianhydride 144.2 g
(0.49 times molar equivalent), γ-butyrolactone 127
6.8 g was added and the mixture was stirred at 70 ° C. for 2 hours under the flow of dry nitrogen, and then 1.96 g (0.02 g) of maleic anhydride was added.
(Mole equivalent) and added and stirred for 1 hour to obtain a polyamic acid solution (polymer concentration: 16% by weight). 200 this solution
g was taken out, and 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 stage of the spacer was set to 2
The temperature is set to 280 ° C. instead of 90 ° C., and the order of forming the colored layers is not blue, green, blue, but blue, green,
A color filter was produced in the same manner as in Example 1 except that the order of red was used. The glass transition temperature of the red color paste after curing was measured in the same manner as in Example 1 and found to be 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 and shape of one spacer (height: 7 μm) 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 protrusions in the cross section was measured using a surface roughness measuring device, it was 0.6 μm. Furthermore, when observed with a scanning electron microscope, the height of the concave projections in the cross section was 0.6 μm, as in the surface roughness measuring machine.

(Production and Evaluation of Color Liquid Crystal Display Device) A liquid crystal display device was produced by the same operation as in Example 1. No display defects such as crosstalk and switching defects occurred in this liquid crystal display device. Further, the display quality did not deteriorate due to the display unevenness.

When this display device was disassembled and the spacers were observed, it was confirmed that the concave portions were crushed and the concave portions were 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 thermoset at 320 ° C. instead of 280 ° C. Since the glass transition temperature of the red color paste after curing was 270 ° C, the thermal curing temperature exceeded the glass transition temperature by 30 ° C or more.

(Confirmation of Shape) The shape and shape of one spacer (height: 7 μm) on the color filter was observed and measured in the same manner as in Example 1. When the uppermost layer of the spacer was observed with an optical microscope, the structure was a trapezoidal shape with rounded ends, and the cross-sectional shape was not concave.

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

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

[0066]

The substrate for a liquid crystal display device of the present invention has a spacer fixed to a non-display area at the time of display, and the cross-sectional shape of the uppermost layer of the spacer is concave.
When a liquid crystal display device is manufactured using this, the following effects are obtained.

(1) Even if there is some variation in spacer height, 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 substrates of the liquid crystal display device and between the electrodes in the substrates via the spacers are reduced, and as a result, a liquid crystal display device of good display quality is obtained. Manufacturing yield is increased.

[Brief description of 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 having a concave spacer formed according to 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 view of a liquid crystal display device when there are variations in the height of a concave spacer.

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

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

FIG. 7 is a schematic view of a liquid crystal display device when there are variations in the height of spacers that are not concave.

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

FIG. 9 is a schematic view when a liquid crystal display device is manufactured using a substrate for a liquid crystal display device having a spacer that is not concave.

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: Colored layer 10: Colored layer 11: Colored layer 12: Black matrix 13: transparent substrate 14: Overcoat 15: Bead spacer 16: Spacer 17: Spacer 18: Spacer 19: Spacer top layer 20: Layers other than the uppermost layer forming the spacer 21: substrate 22: Pattern electrode 23: Conductive film

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Goto 1-1-1, Sonoyama, Otsu City, Shiga Toray Co., Ltd. Shiga Plant (56) Reference JP-A-56-140324 (JP, A) JP-A 4-93924 (JP, A) JP 5-196946 (JP, A) JP 3-197928 (JP, A) JP 7-5475 (JP, A) JP 2-199427 (JP, A) JP 63-237032 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1339

Claims (13)

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