JPH10133011A - Color filter and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the reflectivity of light shielding layers and to increase an optical density by forming colored patterns and/or the light shielding layers in the recessed pattern parts formed on a transparent substrate and to enhance flatness by decreasing the overlaps between the light shielding layers and the colored layers and making the surface of the transparent substrate and the front surfaces of the light shielding layers and the colored layers flush with each other. SOLUTION: Etching is executed by using photoresist patterns 2' obtd. by exposing and developing a photoresist layer 2 via a photomask as a mask to form shallow recessed patterns 4. In succession, a black resin compsn. 5 consisting of black pigments, a resin and a diluting solvent is applied on the transparent substrate 1. This black resin compsn. 5 is scraped off by using a doctor 6, etc., by which the black resin compsn. 5 is packed only into the recessed pattern parts 4 and the resin light shielding layer patterns 7 are formed. The transparent substrate is etched with the formed light shielding layers as a mask, by which the recessed patterns are obtd. Next, the colored patterns of a first color are obtd. by using the photomask and the colored patterns are obtd. by forming the recessed parts of the second color in the same manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used for a color liquid crystal display device and the like and a method of manufacturing the same, and more particularly, to a colored pattern and a light shielding layer (black matrix, hereinafter abbreviated as BM) provided in a gap between the colored patterns. The present invention relates to a color filter and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a BM for a color filter used in a color liquid crystal display device or the like has generally been manufactured by etching a chromium metal film using a photolithography method. However, alternative materials of chromium metal have been studied from the viewpoints of low reflection, low cost, and environmental problems of the BM.

[0003] Among these methods, there is a BM (hereinafter abbreviated as resin BM) method using a black resin in which carbon black is dispersed as a method practically used. The resin BM has a lower reflectance than metal chromium, can improve the display contrast of a color liquid crystal display device, and can be reduced in cost.

However, resin B using carbon black
M has a lower optical density than chromium metal. In order to obtain a sufficient optical density, it is necessary to set the film thickness to a large value, thereby increasing the overlapping step between the resin BM and the colored pattern. If there is a step, there is a possibility that a problem such as poor alignment of liquid crystal due to rubbing failure and disconnection of an upper electrode layer may occur when the portion is used later in a color liquid crystal display device.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a light shielding layer having a low reflectance and a high optical density. The present invention is to provide a color filter with high display quality and excellent flatness in which the transparent substrate surface, the light-shielding layer, and the upper surface of the colored layer coincide with each other, and the overlap between the colored layer and the colored layer is small.

[0006]

According to the present invention, there is provided a color filter having a desired colored pattern on a transparent substrate and a light-shielding layer provided in a gap between the colored patterns. A color filter, wherein the light-shielding layer is formed in a concave pattern portion provided on a transparent substrate.

Further, the method of manufacturing the light-shielding layer includes: (1) a step of providing a photoresist pattern having a desired shape on a transparent substrate. (2) A step of etching a transparent substrate using the photoresist pattern as a mask to provide a concave pattern having a desired shape. (3) A step of applying a black resin composition comprising a black pigment, a resin, and a diluting solvent on the transparent substrate, and thereafter removing the black resin composition other than the concave pattern portion. (4) A step of heating and baking the transparent substrate to obtain a light-shielding layer. And a method for manufacturing a color filter, comprising the steps of:

The method for producing a colored pattern includes the following steps: (1) a step of providing a light-shielding layer having a desired shape on a transparent substrate. (2) A step of forming a concave pattern by etching the transparent substrate using the light-shielding layer as a mask. (3) A step of applying a photosensitive coloring composition of a desired color on a transparent substrate. (4) A step of obtaining a desired colored pattern by mask exposure and development. (5) A step of heating and firing the transparent substrate. (6) A step of forming a concave pattern by etching a transparent substrate using the light shielding layer and the colored pattern as a mask. (7) A step of applying a photosensitive coloring composition of a desired color to the concave pattern portion. (8) A step of forming a desired colored pattern by mask exposure and development. (9) A step of heating and firing the transparent substrate. (10) A step of repeating (6) to (9) as many times as necessary. And a method for manufacturing a color filter, comprising the steps of:

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a method of forming a light shielding layer will be described with reference to FIG. First, the transparent substrate 1
A photoresist layer 2 is formed thereon by spin coating, roll coating, or the like. (A)

As the transparent substrate 1, a glass material such as non-alkali glass and soda glass can be used, and a film material such as polycarbonate can also be used.

The photoresist used for the photoresist layer 2 is used as a mask when etching the transparent substrate, and may be either a negative type or a positive type, and is selected based on the resistance of the transparent substrate to the etching solution.

Next, the photoresist layer 2 is exposed and developed through a photomask 3 having a desired pattern to obtain a photoresist pattern 2 '. (B) (c)

Subsequently, the photoresist pattern 2 'is slightly etched using the photoresist pattern 2' as a mask to form a shallow concave pattern 4 '.
To form (D) At this time, in consideration of the strength of the transparent substrate itself, it is preferable that the depth of the concave portion is 1/100 or less of the thickness of the transparent substrate.
Practically, when the thickness of the transparent substrate is 0.7 mm, the depth of the concave portion is preferably about 5 μm.

As an etching method, NH ₄ F, H
F, a wet process using a chemical solution such as buffered hydrofluoric acid,
Alternatively, a dry process such as plasma etching using a fluorine-based gas such as CHF ₃ or C ₂ F ₆ can be used, and is determined by the composition of the transparent substrate and the photoresist material used. For example, for a non-alkali glass substrate generally used for a color liquid crystal display device, it is suitable to use a novolak-based positive resist as a photoresist and perform etching by a wet process using buffered hydrofluoric acid. The control of the etching in the depth direction is controlled by the processing time of the etching process.

After the etching is completed, the photoresist is stripped with a stripping solution. (E) At this time, an organic alkali such as ethanolamine, diethanolamine, triethanolamine, and tetramethylammonium hydroxide, and an organic solvent such as dimethylsulfoxide and tetrahydrofuran are used as the stripping solution.

Subsequently, a black resin composition 5 comprising a black pigment, a resin and a diluting solvent is applied on a transparent substrate, and thereafter, the black resin composition 5 on the transparent substrate 1 is
, And only the concave pattern portion 4 is filled with the black resin composition to form the resin BM pattern 7. (F) (g)
(H)

As the black resin composition used here, those obtained by dispersing a black pigment in a resin using a dispersant can be used. Examples of the black pigment include carbon black, graphite, and the like.
Titanium oxide, iron black, aniline black and the like are used, and those obtained by mixing an organic pigment and blackening can also be used.

Examples of the dispersant include a nonionic surfactant (eg, polyoxyethylene alkyl ether), an ionic surfactant (eg, sodium alkylbenzene sulfonate, polyfatty acid salt, fatty acid salt alkylphosphate, tetraalkylammonium salt) ), Organic pigment derivatives, polyesters and the like. One type of dispersant may be used alone, or two or more types may be used in combination.

In order to further improve the workability during dispersion, diluting solvents such as ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, diglyme, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether Organic solvents such as ether acetate, ethyl ethoxypropionate, isopropyl cellosolve, isoamyl acetate, 2-heptanone, methyl-n-amyl ketone, and lactic acid esters may be used.

The resin used in the present invention is selected in consideration of the dispersibility of the black pigment used, the resistance after the formation of the resin BM, and the like, and includes acrylic resins, melamine resins, epoxy resins, polyimide resins, and polyamide resins. , A novolak resin or the like, or a mixture of several kinds thereof can also be used.

For the doctor used to scrape the black resin composition other than the concave portions, a sharp blade-shaped jig made of SUS, ceramic, ceramic-coated metal, or the like is used. It is not particularly limited as long as it is one.

Further, the transparent substrate in which only the concave portions are filled with the black resin composition is heated and baked to thermally cure the black resin composition. When a photocurable resin is used as the resin used in the present invention, ultraviolet irradiation may be performed at this time to perform photocuring.

Next, the step of forming a colored pattern will be described with reference to FIG. Using the light-shielding layer formed as described above as a mask, the transparent substrate at the portion where the colored pattern is to be formed is etched to obtain a concave pattern 8. (A) Either a wet process or a dry process may be used as the etching method, but it is preferable to use the same method as that for forming the light shielding layer in terms of manufacturing.

The depth of the concave portion for forming the colored pattern is such a depth (film thickness) from the surface of the light-shielding layer that the desired color characteristics of the dye can be obtained. The concave portion for each color dye may be formed by one etching, and if the relationship between the film thickness and the color characteristics differs depending on the color, the concave portion is formed in order from the color having the smaller film thickness, and the coloring pattern and the light shielding layer are used as a mask. It is also possible to sequentially form a colored pattern, such as by etching to form a second color. Hereinafter, this method will be described.

As the coloring resin, a commercially available photosensitive pigment-dispersed resist can be used. The first colored resin layer 9 is formed by a known coating method such as a spin coating method, a roll coating method, and a slit coating method, but under a condition such that the thickness of the colored resin buried in a desired portion matches the height of the light shielding layer. Perform coat. (B)

Next, a first colored pattern 11 is obtained using the photomask 10. At this time, the opening of the photomask is desirably smaller than the opening partitioned by the light shielding layer. That is, this is to prevent the colored resin from remaining on the light shielding layer when performing the exposure. If the exposure amount is set to be higher than the sensitivity of the colored resin so as to have a tapered shape during development, no gap is formed between the light shielding layer and the formed colored pattern. The formed colored pattern is baked as a hardening treatment, and a first colored pattern is completed. (C) (d)

Next, etching is performed in the same manner as the formation of the concave portion for the first color to form a concave portion for the second color. Coat, exposure,
Development and baking are performed in the same manner to obtain a second colored pattern.
The same process is performed for the third and subsequent colors to obtain a color filter.
(E) (f) (g)

[0028]

【Example】

<Example 1> Non-alkali glass (manufactured by Corning:
A positive resist (“AZ1350” manufactured by Hoechst) was spin-coated on a substrate at 1000 rpm for 10 seconds, and dried by heating at 110 ° C. for 1 minute using a hot plate. Thereafter, the line width is 10 μm, and the pitch is 10 μm.
A photomask for a stripe pattern of 0 μm was brought into close contact with the positive resist side of the transparent substrate, exposed at 30 mJ / cm ² using an ultra-high pressure mercury lamp, immersed in a 1% aqueous solution of tetramethylammonium hydroxide for 60 seconds, and developed. Thus, a positive resist pattern on a transparent substrate was obtained. Subsequently, the transparent substrate was immersed in buffered hydrofluoric acid (manufactured by Hashimoto Kasei Co., Ltd .: “LAL800”) controlled at a liquid temperature of 23 ° C. for 30 minutes to etch the transparent substrate, washed with water, and then immersed in dimethyl sulfoxide for 30 seconds. Then, the positive resist was stripped to obtain a transparent substrate on which a concave pattern was formed. The depth of the concave pattern obtained at this time was 3 μm.

On this transparent substrate, 50 parts of butyl methacrylate, 30 parts of methyl methacrylate, and 2 parts of methacrylic acid
For 100 g of a 30% ethyl cellosolve solution of an acrylic resin consisting of 0 parts, 10 g of carbon black and a yellow pigment ("PAriotor Yellow L182" manufactured by BASF).
0 ") 10 g, a blue pigment (manufactured by BASF:" Heliogen Blue L6700F ") 10 g, a purple pigment (manufactured by Toyo Ink Mfg. Co., Ltd .:" Lionogen Violet RL ") 10
g, as a dispersing agent (“SOLSPERS # 5” manufactured by Zeneca Corporation)
000 "), kneaded well with a three-roll mill, and spread a black resin composition using a spatula.
The black resin on the surface of the transparent substrate was scraped off using a US-made doctor. Subsequently, the film was heated and baked at 230 ° C. for 60 minutes using a clean oven to obtain a light-shielding layer pattern. At this time, the transmittance of the obtained light shielding layer is 0.01% or less,
The reflectance was 0.8%.

Next, buffered hydrofluoric acid (manufactured by Hashimoto Kasei Co., Ltd .: "LAL80") having a liquid temperature of 23 ° C. on the transparent substrate was used.
0 ”) for 12 minutes, and the concave portion was etched by 1.2 μm using the light-shielding layer as a mask. The transparent substrate was coated with a first color blue photosensitive colored resin composition (manufactured by Fuji Hunt Co., Ltd .: “Color Mosaic CB7000”) by a roll coating method so as to fill the recesses by 1.2 μm. After drying at 90 ° C. for 30 minutes, a gap of 100 μm is formed between the mask and the substrate,
Exposure was performed at an exposure amount of 200 mJ / cm ² . The size of the opening of the exposure mask for obtaining a desired pattern was designed so as to be 1.5 μm inward from the opening partitioned by the light-shielding layer. Development and baking were performed to obtain a first colored pattern.

Next, using the blue pattern of the first color and the light-shielding layer as a mask, the substrate was immersed in the etching solution for 2 minutes to obtain the depth of the concave portion of the second color. The recesses were further etched by 0.2 μm to a total depth of 1.4 μm. In addition, 2
Green photosensitive coloring composition (manufactured by Fuji Hunt Co., Ltd.)
"Color mosaic CG7000") was formed in the same manner as in the first color to obtain a second color pattern. Blue, green,
Etching for 2 minutes using the light shielding layer as a mask, 1.6 μm
After the formation of the concave portions, a third colored pattern was obtained using a red photosensitive coloring composition (“Fuji Hunt Co., Ltd .:“ Color Mosaic CR7000 ”)”.

The level difference due to the overlap between the light-shielding layer thus obtained and each colored pattern is 0.3 μm or less, and a smooth color filter can be obtained. Was not seen.

<Example 2> A transparent substrate on which a light-shielding layer pattern was formed in the same manner as in Example 1 was used.
A μm concave portion was formed. 1.4 μm RGB in the recess
When the pattern was formed, no level difference due to the overlap between the light-shielding layer and the colored pattern was observed, a smooth color filter was obtained, and even when a color liquid crystal display device was formed, poor display such as poor orientation was not observed.

<Example 3> A transparent substrate on which a light-shielding layer pattern was formed in the same manner as in Example 1 was used.
A μm concave portion was formed. A blue pattern was formed in the recess using an inkjet method. By sequentially etching, a green pattern having a thickness of 1.4 μm and a red pattern having a thickness of 1.6 μm were formed. Each colored pattern formed by the ink-jet method was formed smaller than the opening part partitioned by the light-shielding layer. However, the pattern flowed at the time of heating and curing, and the gap with the light-shielding layer was filled, and no white spots were generated. The color filter produced in this manner did not show any level difference due to the overlap between the light-shielding layer and the colored pattern, was smooth, and did not show any poor alignment or other display defects even when a color liquid crystal display device was formed.

Example 4 An RGB colored pattern having a thickness of 1.4 μm was formed on a transparent substrate on which a light-shielding layer pattern was formed in the same manner as in Example 2 by using a printing method. Each colored pattern formed by the printing method was formed to be smaller than the opening part partitioned by the light-shielding layer. However, the pattern flowed at the time of heat curing, and the gap with the light-shielding layer was filled, and no white spots occurred. The color filter produced in this manner did not show any level difference due to the overlap between the light-shielding layer and the colored pattern, was smooth, and did not show any poor alignment or other display defects even when a color liquid crystal display device was formed.

<Comparative Example 1> To 100 g of the black resin composition prepared in the same manner as in Example 1, "Aronix M310" manufactured by Toyo Gosei Co., Ltd. was used as a photopolymerizable monomer.
g, 5 g of "Irgacure 907" manufactured by Ciba Geigy as a photopolymerization initiator, and diluted with ethyl cellosolve to a solid content of 20% to obtain a photosensitive black resin composition. The photosensitive black resin composition was coated on a non-alkali glass (Corning: 7059) substrate by 1000
It was spin-coated at 10 rpm for 10 seconds, and dried by heating at 90 ° C. for 30 minutes using a clean oven.

Thereafter, a line width of 10 μm and a pitch of 100 μm
A photomask for the stripe pattern is adhered to the black resin composition side of the transparent substrate, and the photomask for 20
Exposure was performed at 0 mJ / cm ² , development was performed by dipping in a 1% aqueous solution of sodium carbonate for 60 seconds, and heating and baking at 230 ° C. for 60 minutes using a clean oven to obtain a light-shielding layer pattern on a transparent substrate. At this time, the thickness of the light-shielding layer obtained was 3 μm, the transmittance was 0.01% or less, and the reflectance was 0.8%.

On this transparent substrate, a photosensitive colored resin composition (Color Mosaic "CR700" manufactured by Fuji Hunt Co., Ltd.)
0 "," CG7000 "," CB7000 "), the color pattern of RGB was formed by the photolithography method. When the light-shielding layer and the color pattern overlapped, a step of 2 μm or more was generated. Poor alignment of the alignment film occurred in some portions.

<Comparative Example 2> To 100 g of the black resin composition prepared in the same manner as in Example 1, "Aronix M310" manufactured by Toyo Gosei Co., Ltd. was used as a photopolymerizable monomer.
g, Ciba Geigy Co., Ltd .: 5 g of "Irgacure 907" as a photopolymerization initiator, and diluted with ethyl cellosolve to a solid content of 15% to obtain a photosensitive black resin composition. This photosensitive black resin composition was placed on a non-alkali glass (Corning: 7059) substrate at 1500
It was spin-coated at 10 rpm for 10 seconds, and dried by heating at 90 ° C. for 30 minutes using a clean oven.

Thereafter, a line width of 10 μm and a pitch of 100 μm
A photomask for the stripe pattern is brought into close contact with the black resin composition side of the transparent substrate, and a 10-
Exposure was performed at 0 mJ / cm ² , development was performed by dipping in a 1% aqueous solution of sodium carbonate for 60 seconds, and heating and baking at 230 ° C. for 60 minutes using a clean oven to obtain a light-shielding layer pattern on a transparent substrate. The thickness of the light-shielding layer obtained at this time was 0.8 μm, the transmittance was 1% or less, and the reflectance was 0.8%.

On this transparent substrate, a photosensitive colored resin composition (Color Mosaic “CR700” manufactured by Fuji Hunt Co., Ltd.)
0, “CG7000”, “CB7000”), the color pattern of RGB was formed by the photolithography method, and the step at the overlap between the light-shielding layer and the color pattern was 0.5 μm or less, and the color liquid crystal display device was manufactured. In this case, no alignment failure of the alignment film occurred in this portion, but the leakage light from the light-shielding layer was large and the display contrast was lowered.

[0042]

As described above, the present invention has the following effects. That is, since the concave pattern is formed by etching the transparent substrate and the black resin composition is filled in the concave pattern to form the resin BM, the transparent substrate on which the resin BM is formed is smooth. ,
Further, since a concave portion of a portion to be formed next is formed using the already formed pattern and a colored pattern is formed in the concave portion, the resin BM on the transparent substrate formed by the prior art is formed.
As described above, there is no step due to overlap with the colored pattern, and furthermore, the flatness with the transparent substrate is excellent, and the liquid crystal display device manufactured using the color filter manufactured by this method has a problem such as poor alignment. Does not occur.

Further, since the thickness of the resin BM layer, that is, the depth of the concave pattern can be set relatively large, a sufficient optical density can be obtained even if the carbon black content is small, and the resin BM having a low reflectivity can be obtained. Therefore, a color liquid crystal display device with good display characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a color filter manufacturing process according to the present invention.

FIG. 2 is an explanatory view showing an example of a color filter manufacturing process according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent substrate 2 photoresist layer 2 ′ photoresist pattern 3 photomask 4 concave pattern 5 black resin composition 6 doctor 7 resin BM pattern 8 concave pattern 9 first colored resin 10 Photomask 11 ... Coloring pattern of the first color 12 ... Coloring pattern of the second color 13 ... Coloring pattern of the third color

Claims (3)

[Claims] 1. A color filter comprising a transparent substrate and a desired colored pattern and a light-shielding layer provided in a gap between the colored patterns, wherein the colored pattern and / or the light-shielding layer is formed in a concave pattern portion provided on the transparent substrate. A color filter characterized by being performed. 2. A method for manufacturing a color filter comprising a transparent substrate and a desired colored pattern and a light-shielding layer provided in a gap between the colored patterns, wherein the method for manufacturing the light-shielding layer is as follows: Providing a photoresist pattern having the above shape. (2) A step of etching a transparent substrate using the photoresist pattern as a mask to provide a concave pattern having a desired shape. (3) A step of applying a black resin composition comprising a black pigment, a resin and a diluting solvent on the transparent substrate, and thereafter removing the black resin composition other than the concave pattern portion. (4) A step of heating and baking the transparent substrate to obtain a light-shielding layer. A method for manufacturing a color filter, comprising the steps of: 3. A method for manufacturing a color filter, comprising: providing a desired colored pattern on a transparent substrate and a light-shielding layer in a gap between the colored patterns; A step of providing a light-shielding layer having the shape described above. (2) A step of forming a concave pattern by etching the transparent substrate using the light-shielding layer as a mask. (3) A step of applying a photosensitive coloring composition of a desired color on a transparent substrate. (4) A step of obtaining a desired colored pattern by mask exposure and development. (5) A step of heating and firing the transparent substrate. (6) A step of forming a concave pattern by etching a transparent substrate using the light shielding layer and the colored pattern as a mask. (7) A step of applying a photosensitive coloring composition of a desired color to the concave pattern portion. (8) A step of forming a desired colored pattern by mask exposure and development. (9) A step of heating and firing the transparent substrate. (10) A step of repeating (6) to (9) as many times as necessary. A method for manufacturing a color filter, comprising the steps of: