JP2000075124A - Color filter, its production and liquid crystal display device using the color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a color filter of high quality without color mixing at a low cost by continuously injecting a paste through narrow nozzles to form a stripe pattern on a transparent substrate having a black matrix which is produced by depositing an uncured resin layer on a light-shielding film. SOLUTION: The transparent substrate 1 used has a black matrix of a multilayered structure including a light-shielding layer as the lower layer and an uncured resin layer as the upper layer. The sprue 2 has plural nozzles 4a to 4c, and a paste 3 is supplied through a paste supply port 6, injected through the narrow nozzles 4a and 4c and applied among the black matrices on the transparent substrate 1 to form a stripe pattern. The forming method of the black matrix is not limited, and in order to prevent mixing of colors and to obtain projections having a function as a spacer, an uncured resin layer of preferably >=2 μm, more preferably 3 to 15 μm thickness is formed as the upper layer of the light-shielding layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter having a spacer function, a method for manufacturing the same, and a liquid crystal display using the color filter.

[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 an electrode substrate on which a thin film transistor (TFT) and a plurality of scanning electrodes are arranged, and a color filter. It is manufactured by spraying a plastic bead in the pixel portion and a glass fiber spacer in the frame portion between the substrate and the substrate. Since these spacers lower the display quality of the liquid crystal display device, a projection having a spacer function is formed on the black matrix of the color filter, and a liquid crystal display device using this color filter and no conventional spacer is used. Japanese Patent Application Laid-Open Nos. Sho 56-140324, Sho 63-82405, and Hei 4-93
JP-A-924 and JP-A-5-196946 propose a liquid crystal display device using a structure in which colored layers forming a color filter are overlapped as a spacer.
As a method of manufacturing a color filter in which protrusions having a spacer function are formed on a black matrix, these proposals are compared with a method of forming a color filter and then forming the protrusions having a spacer function by photolithography. Although this method has the advantage of shortening the process, red, blue, and green color pastes are sequentially applied and photolithographically processed on a transparent substrate having a black matrix prepared in advance by a photolithography method to form each pixel. This results in adding the complexity of projection formation to the conventional color filter process of forming.

On the other hand, as a rational method of manufacturing a color filter to avoid complexity in a general method of manufacturing a color filter, it has been proposed to spray a colored ink by an ink jet method to form a colored layer. (JP-A-59-75205). In this method, in order to avoid color mixing between colors, a method is used in which a convex portion serving as a boundary is formed in advance with a substance having poor wettability to ink,
Further, a method has been proposed in which a colored portion is wetted with a substance having good wettability (Japanese Patent Application Laid-Open No. 9-203803).
However, the production of a color filter that forms a colored layer by an ink jet method is largely restricted by ink.
Practically, it is necessary to use water-based pigment dispersion ink or dye ink, so there are many problems in pixel flatness, chemical resistance and light resistance, and avoid partial color mixing between each color It was difficult.

As a method of manufacturing a color filter which solves these problems, a method of extruding a color ink or a color paste through a die having a plurality of slits formed on a transparent substrate to obtain a desired pattern has been proposed. (JP-A-5-11105, JP-A-5-105105)
No. 142407). However, even in these manufacturing methods, it was basically difficult to avoid partial color mixing between the colors.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the art, and has as its object to be applied to a conventional photolithography method while taking advantage of the ink jet method. An object of the present invention is to provide a coating method that can use a color paste or ink and does not cause partial color mixing, and also provides a simple method of manufacturing a color filter having a projection having a spacer function. Another object of the present invention is to provide a color filter manufactured by the method and a liquid crystal display device using the color filter.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
This can be achieved by the following configuration. That is, the lower layer is a resin black matrix or a metal-based black matrix, and the upper layer is continuously formed from a die having a plurality of pore nozzles on a transparent substrate having a black matrix having a multilayer structure composed of an uncured resin layer. A method for manufacturing a color filter, comprising a step of forming a stripe pattern by discharging and applying a paste. Further, the color filter of the present invention is a color filter manufactured by the method, and the liquid crystal display device is a liquid crystal display device using the color filter.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual view of a base having a fine hole nozzle used in the present invention.
It has a plurality of nozzles 4a, 4b, 4c. The paste 3 is supplied from the paste supply port 6. FIG. 2 shows the pore nozzle 4
3 shows a state in which the paste 3 is discharged from the substrate 1 and applied between the black matrices 5 on the transparent substrate 1. FIG. 3 shows an example of application of the paste using the die of FIG. 1. A paste of three colors is applied between the black matrix 5 on the transparent substrate 1 by the die 2a, 2b, 2c having the pore nozzle 4. Is done.

As a die having a plurality of fine nozzles used in the present invention, a fine die having a plurality of fine nozzles arranged in place of a slit in a slit state, as shown in FIG. Are preferred. . The slit die coating can be applied to the entire surface of a single wafer by automatically controlling the driving of the transparent substrate or the base and the discharge of the paste, and similarly, the single base can be applied to the stripe by using the base of the present invention.

The width of the base is preferably substantially the same as the width of the substrate. However, by applying a large number of scans, a short width is possible. The arrangement of the pore nozzles corresponds to the pixel stripes on the transparent substrate, and it is possible to design a die that applies all three colors at once. However, red (R), green (G), and blue (B) 3) is easy to prepare three types of bases, sequentially apply each color to the concave portion at every three pitches, and form stripes of three colors. The size of the pore nozzle is usually 5 to 100 μm, preferably 10 to 80 μm in the case of a circular nozzle. The shape of the nozzle is not particularly limited, and is appropriately selected according to the properties of the paste and the application form.

The transparent substrate used in the production of the color filter of the present invention is a transparent substrate having a black matrix having a multilayer structure having a light-shielding layer as a lower layer and an uncured resin layer as an upper layer. As, for example, a metal chromium film or a laminate of metal chromium and chromium oxide, or carbon black, a black layer formed of a resin such as a black pigment such as titanium black,
There is a method in which a photoresist is applied thereto, the resist in the pixel portion is removed by a photolithography method, and a layer of metal chromium or the like is removed by etching. Further, as a method advantageous in cost, there is a method of forming a black film made of a material containing a black pigment such as carbon black and titanium black and a photocurable resin, and subjecting the black film to a desired patterning by a photolithography method.

In the present invention, the method of forming the black matrix is not particularly limited, but is preferably 2 μm or more, more preferably, 2 μm or more on the light-shielding layer in order to prevent color mixing and to obtain projections having a spacer function. Needs to have an uncured resin layer of 3 to 15 μm. Such an uncured resin layer can be formed by photolithography of at least one more resin layer on the black matrix. However, economically, after forming a multi-layer coating film, once It is preferable to obtain a multilayer black matrix by photolithography, and it is possible to process only the upper layer by utilizing the difference in developability between multiple layers in a later step. In order to apply this method, polyimide or polyimide precursor (polyamic acid)
A resin black matrix can be used effectively.

As an effective application example of the present invention, specifically, a cured resin black matrix or a metal-based black matrix is disposed in a lower layer, and an uncured resin with a positive type resist which is an unexposed portion on a surface layer is disposed in an upper layer. Distribute resin,
After forming the color stripe pattern, a method in which the uncured resin with the resist layer is processed by a photolithography method is preferably mentioned, and a spacer function at the time of cell assembly is preferably provided.

Further, a resin black matrix or a metal black matrix is disposed in a lower layer, a negative photosensitive resist is disposed in an upper layer, and a color stripe pattern is formed on a substrate having the black matrix, and then processed by a photolithography method. A method of forming a projection having a spacer function at the time of cell assembly can also be preferably mentioned.

In these methods for imparting a spacer function when assembling cells, the thickness of the resin layer having a positive photoresist layer or the thickness of the negative photosensitive resin layer is preferably 3 to 15 mm.
The thickness must be as thick as μm, which is also effective for preventing color mixing of the stripe pattern.

In order to avoid color mixture between the colors, a method is used in which a convex portion serving as a boundary is formed in advance between black matrices with a material having poor wettability to the paste, or a color is formed using a material having good wettability. A method of keeping the part wet may be applied.

The composition and properties of the paste used in the present invention are not particularly limited, but a color paste mainly composed of an organic solvent, a resin component and a pigment component is preferably used from the viewpoint of leveling properties. Further, as the uncured resin component of the black matrix upper layer used in the present invention, in consideration of the photolithography process after coloring, alkali development can be applied, and a resin component that is cured by heating or cured by energy rays such as ultraviolet rays. It is preferred to use.

As the component which is cured by heating, various thermosetting resins can be widely used. Above all, a polyamic acid as a polyimide precursor is preferably used, and a low-temperature curing polyimide precursor using an aliphatic ether diamine component as a raw material component is particularly preferably used. Examples of the component that is cured by energy rays or heat include a combination of a polyvalent acrylate, a polyvalent methacrylate and a photoreaction initiator, and, if necessary, an acrylic resin component.

The uncured resin component is used as a filler.
It may contain barium sulfate, silica powder, carbon black, titanium black, and other organic and inorganic pigment components.

The color filter of the present invention is a color filter manufactured by the above-described manufacturing method. The color filter is formed by successively discharging and applying paste from a die having a plurality of fine-hole nozzles, or sequentially or all at once. These are three color filters obtained by applying a pattern and forming pixels. This color filter is
Liquid crystal display element, electric chromic display element, P
Used as a display element in combination with LZT or the like. It can also be used for applications using color cameras and other color filters.

The liquid crystal display device of the present invention is a liquid crystal display device using the above-described color filter. For example, a polyimide-based alignment film is provided on the ITO layer of the color filter, rubbed and subjected to rubbing. A liquid crystal display element substrate having a thin film transistor is also provided with a polyimide-based alignment film, subjected to a rubbing treatment, and the two substrates are attached to each other with a sealing agent applied to a black matrix in a peripheral frame portion. After the liquid crystal is introduced from the injection port, the injection port is sealed, and a polarizing plate is attached to both sides of the obtained liquid crystal injection cell.

[0021]

Embodiments of the present invention will be described below.

The polyimide precursor solution, black paste, and colored paste used in the examples were prepared in advance by the following method.

1. Polyimide precursor solution A 4,4'-diaminodiphenyl ether 210.2
g, 3,3 'diaminodiphenyl sulfone 69.5
g and bis (3-aminopropyl) tetramethyldisiloxane (17.4 g) in 3825 g of γ-butyrolactone
While stirring, 149.6 g of pyromellitic dianhydride and 225.5 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride
Was added and stirred at 60 ° C. for 3 hours. Then, 2.75 g of maleic anhydride was added, and the mixture was further stirred at 60 ° C. for 2 hours.
% By weight of a polyimide precursor solution A was prepared.

2. Polyimide precursor solution B 3,9-bis (3-aminopropyl) -2,4,8,1
0-tetraoxaspiro [5,5] undecane 754.6
g, 4,4'-diaminodiphenyl ether 275.
4 g, 3,3 'diaminodiphenyl sulfone 27
3.1 g and 68.3 g of bis (3-aminopropyl) tetramethyldisiloxane were added to γ-butyrolactone 62
06.4 g, N-methyl-2-pyrrolidone 6206.4
g, 853.2 g of 4,4'-oxydiphthalic acid and 3,3 ', 4,4
'-Benzophenonetetracarboxylic dianhydride 86
After adding 7.8 g and stirring at 60 ° C. for 3 hours, 10.8 g of maleic anhydride was added, and the mixture was further stirred at 60 ° C. for 2 hours to prepare a 15% by weight polyimide precursor solution B.

3. Black paste A carbon black mill base having the following composition was dispersed at 1500 rpm for 2 hours using a Dynomill to prepare a black paste. The viscosity of the black paste was 28 cP, and the yield value was 3.0 × 10 ⁻⁴ Pa.

Carbon black (PH value 2.8, average primary particle size 28 nm, average secondary particle size 55 nm, furnace black) 92 parts Polyimide precursor solution A 460 parts N-methylpyrrolidone 1200 parts Zirconia beads 2000 parts 4 . Coloring paste Color Index No.65300 Pig as red, green and blue pigments respectively
Colo, a dianthraquinone pigment represented by ment Red 177
r Index No.74265 Pigment Green 36, a phthalocyanine green pigment represented by Color Index No.74160 Pigment
A phthalocyanine blue pigment represented by Blue 15-4 was prepared.

The above pigments were mixed and dispersed in the polyimide precursor solution B to obtain three kinds of colored pastes of red, green and blue.

Example 1 Alkali-free glass ("OA-", manufactured by NEC Corporation)
2 ″) A black paste was applied on the substrate using a slit die shown in FIG. 4 and dried at 130 ° C. for 20 minutes to obtain a black coating having a thickness of 1.5 μm. Similarly, the polyimide precursor solution B was coated with a slit die and dried to form a coating film having a thickness of 5.5 μm.

Thereafter, a positive resist (Shipley “micr”
oposit "RC100 30cp) was applied with a spinner to a thickness of 1.5 μm after drying, and dried at 80 ° C. for 20 minutes. Using an exposure machine PLA-501F manufactured by Canon Inc.,
Exposure was performed through a photomask for a black matrix, and the development of a positive resist and the etching of the polyimide precursor and the black coating film were simultaneously performed with an alkali developing solution (Shipley @microposit "351). The thickness of the black matrix layer is 6.5 μm, the thickness of the resist layer is 1.5 μm, and the opening is 240 μm in the vertical direction.
A grid-like black matrix of μm and a horizontal direction of 80 μm was provided. A green paste was applied in stripes to the transparent concave portions on the resin black matrix by using a die having a plurality of fine nozzles as shown in the model of FIG. After a heat treatment at 100 ° C. for 20 minutes to form a green striped pixel, similarly, a striped red,
Blue pixels were formed such that the pixel spacing of the three colors was 10 μm. The substrate having the stripe pixels of three colors obtained in this manner was treated with methyl cellosolve acetate to remove the remaining resist layer.

After this substrate is coated with a positive resist again and dried, an exposure unit PLA-501F manufactured by Canon Inc. is used to leave a projection portion having a spacer function and a pixel portion on a black matrix via a photomask through a photomask. Then, only the polyimide precursor layer on the black matrix with good exposure and developability is alkali-developed, then treated with methyl cellosolve acetate, and the remaining resist layer is peeled off. The black matrix part having the protrusion was cured.

Next, an epoxy resin-based overcoat coating solution was applied on the entire surface by a spin coater and cured to obtain a color filter substrate having a protective film of 1 μm and having projections having a spacer function. On top of this, as a conductive film
An ITO layer was formed by a sputtering method to obtain a color filter. No defects such as color mixing were observed in the obtained color filter. A polyimide-based alignment film was provided on the ITO layer of the color filter, and a rubbing treatment was performed.

Similarly, a substrate for a liquid crystal display device having a thin film transistor opposed thereto was also provided with a polyimide-based alignment film and subjected to a rubbing treatment. The two substrates were bonded together with a sealant applied to a black matrix in a peripheral frame portion.

After the liquid crystal was introduced through the injection port provided in the seal portion, the injection port was sealed. A polarizing plate was stuck on both sides of the liquid crystal injection cell thus obtained to produce a liquid crystal display device. This liquid crystal display showed good display quality.

Example 2 Alkali-free glass (manufactured by NEC Corporation, "OA-
2 ″) A black paste was applied to the substrate using the slit die shown in FIG. 4 and semi-cured at 120 ° C. for 20 minutes to obtain a black coating film having a thickness of 1.5 μm.

A negative resist film (prototype of Toray Industries, Inc., acrylic resist) having a thickness of 5 μm was formed on the coating film by the same operation. After this, a positive resist (Shipley
After applying “microposit” RC100 30cp) with a spinner,
It was dried at 80 ° C. for 20 minutes. Exposure machine PLA manufactured by Canon Inc.
Exposure was performed through a photomask using -501F, and the development of a positive resist and the etching of a negative resist and a black coating film were simultaneously performed with an alkali developing solution (Shipley @microposit "351). After drying with hot air and treating with methyl cellosolve acetate, the remaining positive resist was peeled off, and a grid-like black matrix having a thickness of 6.5 μm with the positive resist remaining on the matrix, an opening of 240 μm in the vertical direction, and 80 μm in the horizontal direction was provided. The transparent paste on the resin black matrix was stripe-coated with a green paste using a die having a plurality of fine-hole nozzles as shown in the model of FIG. After the stripe pixels are formed, the stripe-shaped red and blue pixels are similarly
The pixels were formed so that the pixel spacing of the three colors was 20 μm. The substrate having the striped pixels of three colors obtained in this manner is heat-treated at 120 ° C. for 20 minutes, and a projection-equivalent portion on a black matrix is exposed through a photomask using an exposure machine PLA-501F manufactured by Canon Inc. After exposure, the resin black matrix is treated with an aqueous alkali solution to remove only the negative resist layer excluding the protrusions on the resin black matrix, and then heat-treated at 230 ° C. for 30 minutes to remove the resin black matrix and the protrusions and pixel portions thereon. Cured.

Then, an epoxy resin-based overcoat coating solution was applied on the entire surface with a spin coater and cured to obtain a color filter substrate having a 2 μm protective film. An ITO layer was formed thereon as a conductive film by a sputtering method to obtain a color filter. No defects such as color mixing were observed in the obtained color filter.

A polyimide alignment film was provided on the ITO layer of the color filter and rubbed. Similarly, a liquid crystal display element substrate having a thin film transistor opposed thereto was also provided with a polyimide-based alignment film and subjected to a rubbing treatment. The two substrates were bonded together with a sealant applied to a black matrix in a peripheral frame portion.

After the liquid crystal was introduced through the injection port provided in the seal portion, the injection port was sealed. A polarizing plate was stuck on both sides of the liquid crystal injection cell thus obtained to produce a liquid crystal display device. This liquid crystal display showed good display quality.

Example 3 Non-alkali glass (manufactured by NEC Corporation, "OA-
2 ″) On top, the opening is 240 μm vertically and 80 μm horizontally
A polyimide precursor solution A was coated thereon using a slit die shown in FIG. 4 and dried at 80 ° C. for 10 minutes. Semi-cure for 7 minutes, 7μ
An m-thick coating film was formed. Thereafter, a positive resist (Shipley microposite RC100 30 cp) was applied by a spinner and dried at 80 ° C. for 20 minutes, and exposed through a photomask using an exposure machine PLA-501F manufactured by Canon Inc., and an alkali developer ( After simultaneously developing the positive resist and etching the polyimide precursor in Shipley "microposit" 351), it was dried with hot air at 130 ° C. for 20 minutes, and the positive resist was stripped with methyl cellosolve acetate. A grid-like black matrix having a polyimide precursor layer having a thickness of 7 μm as an upper layer and an opening of 240 μm in the vertical direction and 80 μm in the horizontal direction was provided. The green paste was applied in stripes using a die having a fine pore nozzle. After forming the green stripe pixels, similarly striped red, blue pixel,
The pixels were formed so that the pixel spacing of the three colors was 20 μm. A positive resist is applied thereon again, and heat-treated at 90 ° C. for 20 minutes. Using an exposure machine PLA-501F manufactured by Canon Inc., a 4 μm spacer serving as a spacer is formed on the black matrix.
After the entire surface was exposed through a photomask designed to leave a column having a height, development was performed, and the positive resist was peeled off with methylcellosolve acetate. Next, heat treatment was performed at 280 ° C. for 30 minutes to harden the column portions and the pixel portions on the black matrix. In this way, a color filter substrate having a 4 μm pillar portion serving as a spacer was obtained.

On top of this, as a conductive film, an IT
An O layer was formed to obtain a color filter. A polyimide-based alignment film was provided on the ITO layer of the color filter, and a rubbing treatment was performed. Similarly, a liquid crystal display element substrate having a thin film transistor opposed thereto was also provided with a polyimide-based alignment film and subjected to a rubbing treatment. The two substrates were bonded together with a sealant applied to a black matrix in a peripheral frame portion. No spacer beads were used for this bonding.

After the liquid crystal was introduced through the injection port provided in the seal portion, the injection port was sealed. A polarizing plate was stuck on both sides of the liquid crystal injection cell thus obtained to produce a liquid crystal display device. This liquid crystal display showed good display quality.

[0042]

According to the present invention, a paste is continuously discharged from a die having a plurality of fine nozzles on a transparent substrate having a black matrix comprising a light-shielding film and an uncured resin layer formed on the light-shielding film. And a method of manufacturing a color filter, characterized by including a step of forming a stripe pattern by using the method. Further, by using the color filter in a liquid crystal display device, excellent quality display can be achieved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a base having a fine hole nozzle used in the present invention.

FIG. 2 is a diagram showing a state in which a paste is applied between a fine hole nozzle and a black matrix on a transparent substrate.

FIG. 3 is a diagram showing an example of applying a paste.

FIG. 4 is a schematic diagram of paste application by a slit die on a transparent substrate.

[Explanation of symbols]

 1, 11: transparent substrate 2, 2a, 2b, 2c: base 3, 13: paste 4, 4a, 4b, 4c: pore nozzle 5: black matrix 6: paste supply port 12: slit die

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H048 BA66 BB02 BB22 BB44 2H089 HA28 JA07 QA12 2H091 FA03Y FB02 FB08 FC05 FC23 LA15

Claims (9)

[Claims] 1. A base having a plurality of fine-hole nozzles on a transparent substrate having a lower layer composed of a resin black matrix or a metal-based black matrix and an upper layer being an uncured resin layer having a multilayer structure having a multilayer structure. A step of forming a stripe pattern by continuously discharging and applying a paste from the color filter. 2. The method according to claim 1, wherein the resin black matrix is a polyimide or a polyimide precursor resin black matrix. 3. The black matrix has a multilayer structure,
3. The method for producing a color filter according to claim 1, wherein the lower layer is a resin black matrix or a metal-based black matrix, and the upper layer is an uncured resin layer having a positive resist remaining on the surface layer. 4. The method according to claim 3, wherein the uncured resin is a polyimide precursor. 5. The black matrix has a multilayer structure,
3. The method according to claim 1, wherein the lower layer is made of a resin black matrix or a metal black matrix, and the upper layer is a negative photosensitive resist. 6. A paste is continuously discharged from a die having a plurality of fine-hole nozzles onto a transparent substrate having a black matrix having a multilayer structure in which an upper layer is formed of an uncured resin layer to form a stripe pattern. Color filter. 7. A stripe pattern is formed by continuously applying and drying a paste from a die having a plurality of fine-hole nozzles on a transparent substrate having a black matrix having a multilayer structure in which an upper layer is composed of an uncured resin layer and drying the paste. After that, the upper layer resin layer of the black matrix is photolithographically processed to form a projection pattern, thereby forming a color filter. 8. The black matrix has a multilayer structure,
The color filter according to claim 7, further comprising a projection having a spacer function on the black matrix. 9. A stripe pattern is formed by continuously discharging and applying paste from a die having a plurality of fine-hole nozzles onto a transparent substrate having a black matrix having a multilayer structure in which the upper layer is composed of an uncured resin layer. A liquid crystal display device comprising a color filter.