JPH08227010A - Production of color filter - Google Patents

Abstract

PURPOSE: To obtain a black matrix substrate having enough resolution and high optical density at a low cost by incorporating a metal compd. into the exposed part of a water-soluble resin layer and bringing the layer into contact with an electroless plating liquid to form a black layer. CONSTITUTION: A hydrophilic resin which forms a black accepting layer is applied on a transparent substrate 11 and hardened to form a hydrophilic resin layer 21. Then an acrylic photosensitive resin colored by dispersing a pigment is applied, exposed and developed to form a color pixel 3 of the first color. Then the resin is post-baked. In this process, dehydration of the hydrophilic groups such as carboxyl groups and hydroxyl groups included in the acrylic photosensitive resin is promoted at the same time to make the color pixel 3 hydrophobic. The same process is carried out to successively form pixels 4, 5 of the second and third colors. Finally, the substrate is brought into contact with a soln. of a metal compd. which acts as the catalyst for electroless plating so that the catalyst is incorporated into the black accepting layer. Then the substrate is brought into contact with an electroless plating liquid to form a black layer 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter, and more particularly to a method for manufacturing a color filter used for a color liquid crystal display device, a line sensor or the like.

[0002]

2. Description of the Related Art In recent years, a monochrome or color liquid crystal display has been particularly noticed as a flat display. Liquid crystal displays include an active matrix system and a simple matrix system for controlling the three primary colors, and a color filter is used in each system. A color liquid crystal display uses three primary colors (R.G.B.) for the constituent pixels,
Color display is performed by controlling the transmission of light of each of the eight primary colors by electrical switching of the liquid crystal.

This color filter is constructed by forming each colored layer, a protective layer and a transparent electrode layer on a transparent substrate.
And in order to increase the coloring effect and display contrast,
A light-shielding layer (black matrix) is formed at the boundary portion of each of the R, G, and B pixels of the colored layer. Further, in an active matrix type liquid crystal display, since a thin film transistor (TFT) is used as a switching element, it is necessary to suppress light leak current. Therefore, a higher light blocking property is required for the light blocking layer (black matrix). Such a light shielding layer (black matrix) is not limited to color liquid crystal displays,
It is also required for monochrome liquid crystal displays for the same reason.

Conventionally, as the light-shielding layer (black matrix), a chromium thin film is photo-etched to form a relief, a hydrophilic resin relief is dyed, a relief formed using a photosensitive solution in which a black pigment is dispersed,
There are those formed by electrodeposition of black electrodeposition paint, those formed by printing, and the like.

However, the chrome thin film formed by photo-etching to form a relief has high dimensional accuracy, but it requires a vacuum film forming process such as vapor deposition or sputtering and is complicated in manufacturing process. It is costly, and it is necessary to reduce the reflectance of chrome in order to increase the display contrast under strong external light.
It was necessary to perform sputtering of low-reflecting chrome, which requires higher manufacturing costs. Further, the method using a photosensitive resist in which the black dye or pigment is dispersed, although the manufacturing cost is low, it is difficult to obtain sufficient light-shielding property because the photoprocess is likely to be insufficient because the photosensitive resist is black. However, there is a problem that a high quality black matrix cannot be obtained. Further, although the black matrix formation by the above-mentioned printing method can reduce the manufacturing cost,
There was a problem that the dimensional accuracy was low.

In order to solve the above problems, a relief formed by exposing and developing a photosensitive resist layer containing a hydrophilic resin in a predetermined pattern contains a metal compound which serves as a catalyst for electroless plating. And after heat treatment,
A method of precipitating metal particles in the relief by electroless plating to form a light-shielding layer (black layer), or a photosensitive resist layer containing a hydrophilic resin and a metal compound serving as a catalyst for electroless plating is predetermined. A method has already been proposed in which the relief formed by exposing and developing with the pattern is subjected to heat treatment, and then metal particles are deposited in the relief by electroless plating to form a light-shielding layer (black layer). Kaihei 5-303090). The light-shielding layer (black layer) obtained by these methods has a high optical density and a low reflectance with good dimensional accuracy, and has the advantage that the manufacturing cost can be reduced because a vacuum process or the like is unnecessary. I have it.

[0007]

However, in the actual production of the black matrix substrate, in order to prevent damage of the photomask and shorten the exposure processing time, the conventional contact exposure is changed to proximity (proximity).
The current situation is that the process is shifting to exposure. Generally, the proximity exposure tends to have a lower resolution than the contact exposure, and even in the method disclosed in the above-mentioned JP-A-5-303090, if the proximity exposure is adopted, sufficient resolution cannot be obtained. There was a problem.

From the viewpoint of the manufacturing process of the color filter, after forming the black layer on the glass substrate,
Furthermore, since R, G, B, and three colored pixels have to be formed, a total of four photolithography processes are required, and the manufacturing process is still long, and in terms of yield, equipment, and manufacturing costs. Was desired.

Furthermore, particularly accurate alignment accuracy is required between the black layer and the colored layers of the R, G and B pixels. Contrary to this requirement, if the accuracy is deteriorated, white light leakage called white spot occurs, or if it deteriorates further, the colored layer protrudes to the adjacent pixel to cause color mixture.

The present invention was devised in view of the above-mentioned circumstances, and even when employing proximity exposure, a black matrix substrate having sufficient resolution and high optical density can be produced at low cost. It is an object to provide a manufacturing method that can be manufactured.

[0011]

In order to achieve such an object, the present invention forms a water-soluble resin layer on a transparent substrate and forms a hydrophobic colored pixel layer on the water-soluble resin layer. Forming in a predetermined pattern and exposing the water-soluble resin layer in the predetermined pattern, and then contacting an aqueous solution of a metal compound serving as a catalyst for electroless plating, so that the metal compound is contained in the exposed portion of the water-soluble resin layer. Then, the black layer is formed by contacting with an electroless plating solution.

The present invention will be described in detail below.

According to the present invention, the black receptive layer is not patterned on a transparent substrate as in the conventional case, but the receptive layer is simply cured by light or heat energy, and a so-called acrylic pigment is dispersed on the photosensitive layer. Forming R, G, and B colored pixels with a photosensitive resin, and then immersing these together with the substrate in an electroless plating solution such as nickel to disperse the pigment in the photosensitive resin layer (R, G, B). The present invention provides a method for producing a black matrix (black layer) by selectively precipitating a metal on a portion other than each colored pixel B). According to the present invention, the so-called black receiving layer in which the black layer is finally formed must be hydrophilic, and in the hydrophobic resin, the water solubility of the metal compound is not impregnated in the resin, so that the catalyst also enters the resin. It focuses on the inability to do so. Based on this idea, by making each of the R, G, and B colored pixels hydrophobic and making the other parts hydrophilic, a black layer is selectively formed only on the parts other than the R, G, and B colored pixels. The gist of the present invention lies in the formation of the above.

Further, in the present invention, in the acrylic resin which is the main component of the photosensitive resin constituting the so-called pigment dispersed R, G, B colored pixels, the hydrophilic group present therein is The heat treatment treatment by post-baking causes a dehydration reaction and changes to a hydrophobic property, and as a result, the electroless plating solution does not impregnate the acrylic resin and metal deposition does not occur. That is, since the R, G, and B colored pixels have no metal deposition, there is no black coloring, and the property of selectively coloring only the other black receiving layers is utilized.

Next, a more specific aspect of the present invention will be described below.
This will be described with reference to the drawings.

First, a sufficiently washed transparent substrate 11 such as glass is prepared (FIG. 1A). Then, a hydrophilic resin to serve as a black receiving layer is applied onto the transparent substrate 11 and cured to form a hydrophilic resin layer 21 (FIG. 1).
(B)). Examples of the hydrophilic resin used include polyvinyl alcohol, resins composed of monomers having an acrylamide-based hydrophilic group, casein, gelatin, fish glue, egg white and the like. Further, the hydrophilic resin layer 21 is usually added with a crosslinking agent so as to be cured by light or heat energy. Thereby, the coating film can be sufficiently cured by light or heat energy.
No patterning is required during this curing process,
It is sufficient to form the film in a so-called solid state.

Next, an acrylic photosensitive resin colored by dispersing a pigment is applied, exposed and developed to form a colored pixel 3 of a predetermined first color (for example, R) (FIG. 1 (c)). ). Then, post-baking is performed at about 180 ° C. for about 5 minutes. The post-baking treatment is usually performed for the purpose of removing excess solvent and the like in the resin, for the purpose of insufficient curing by photocrosslinking, and for further promoting the curing by heat energy. In the present invention, at the time of this post-baking treatment, at the same time, the dehydration reaction of the hydrophilic group contained in the acrylic photosensitive resin, for example, the carboxyl group or the hydroxyl group is promoted to make the colored pixel 3 hydrophobic. Do the same process,
A second color (for example, G) colored pixel 4 and a third color (for example, B) colored pixel 5 are sequentially formed (FIG. 1).
(D)).

Finally, the above-mentioned substrate is brought into contact with an aqueous solution of a metal compound serving as a catalyst for electroless plating to contain the catalyst in the black receiving layer, and then brought into contact with the electroless plating solution to form the black layer 40. To form.

At this time, the R, G, and B colored pixels 3, 4,
Since 5 is hydrophobic and is not impregnated with the catalyst, the colored pixels 3, 4, 5 are not colored with metallic black, and the portions covered with the colored pixels 3, 4, 5 are also resisted by the colored pixels. Since the catalyst is not impregnated, no metallic black is generated and the transparent state is maintained.

Here, the metal compound serving as a catalyst for electroless plating used in the present invention is, for example, palladium,
Chlorides such as gold, silver, platinum, and copper, water-soluble salts such as nitrates, and complex compounds are used, and an activator solution for electroless plating that is commercially available as an aqueous solution can be used as it is. When such a metal compound is contained in the water-soluble photosensitive resin composition as described above, it is 0.0000.
It is preferable that the content is 1 to 0.001% by weight.

The electroless plating solution is, for example, hypophosphorous acid, sodium hypophosphite, sodium borohydride,
A reducing agent such as N-dimethylamineborane, a borazine derivative, hydrazine or formalin, and a water-soluble reducible heavy metal salt such as nickel, cobalt, iron, copper or chromium, and a plating rate and a reduction efficiency are improved. Basic compounds such as caustic soda and ammonium hydroxide, inorganic acids,
Aiming at stability of heavy metal ions, pH adjusting agents such as organic acids, buffering agents typified by alkali salts of oxycarboxylic acids such as sodium citrate and sodium acetate, boric acid, carbonic acid, organic acids and inorganic acids. In addition to the complexing agent, an electroless plating solution containing a promoter, a stabilizer, a surfactant, etc. is used.

Two or more types of electroless plating solutions may be used in combination. For example, first, an electroless plating solution containing a boron-based reducing agent such as sodium borohydride that is easy to form a nucleus (for example, a nucleus of palladium when palladium is used as a metal compound serving as a catalyst for electroless plating) is used. Then, an electroless plating solution containing a hypophosphorous acid-based reducing agent having a high metal deposition rate can be used. In any of the black matrix substrate manufacturing methods described above,
The reflectance of the obtained light-shielding layer at a wavelength of 545 nm is 30% at the maximum, usually 5% or less, which is extremely low as compared with the reflectance (50 to 80%) of the light-shielding layer formed by a conventional chromium thin film, which is excellent. Display quality can be obtained.

In any of the above-mentioned methods for producing a black matrix substrate, the light-shielding layer (black layer) having an optical density of 3.0 or more can be obtained by changing the plating time.
Although it is possible to obtain the above, it is preferable that the optical density is 2.0 or more from the viewpoint of shielding the above-mentioned TFT and improving the contrast. When the optical density is less than 2.0, it does not sufficiently function as a light shielding layer and cannot be put to practical use as a black matrix substrate.

Further, the thickness of the black receiving layer can be freely set by changing the coating thickness of the water-soluble photosensitive resin, but the thickness of the light shielding layer (black layer) is 0.1. ~ 5.0 μm, preferably 0.1-2.0
The range is preferably μm.

[0025]

EXAMPLES The present invention will be described in more detail below by showing specific examples (Examples 1 and 2). Example 1 ( Preparation of Water-Soluble Resin) First, as a water-soluble resin, a copolymer of one kind of acrylamide monomer (N-mono-substituted acrylamide) and another monomer was used. A water-soluble photosensitive resin composition having the above composition was prepared.

N-diacetone acrylamide / acrylamide copolymer: 2.7 parts by weight 4,4′-diazidostilbene-2,2′-disulfonic acid disodium salt: 0.3 parts by weight water: 97 Parts by weight Silane coupling agent (KBE-603, manufactured by Shin-Etsu Chemical Co., Ltd.) ... 0.03 parts by weight (adjustment of coloring ink for printing) Then, as a coloring ink for printing, the following composition was adjusted. . Composition of ink for red printing -Polyester acrylate resin (Aronix M-7100 manufactured by Toagosei Kagaku Kogyo Co., Ltd.) ... 70 parts by weight-Diallyl phthalate prepolymer ... 30 parts by weight-Pigment (Rionol Blue ES) (Toyo Ink Mfg. Co., Ltd.) CI Pigment Blue 15: 6 manufactured by Co., Ltd. 15.5 parts by weight Pigment (Rionogen Violet RL) (CI Pigment Violet 23 manufactured by Toyo Ink Mfg. Co., Ltd.) 4 parts by weight Green Composition of printing ink -Polyester acrylate resin (Toagosei Kagaku Kogyo Co., Ltd., Aronix M-7100) 70 parts by weight-Diallyl phthalate prepolymer 30 parts by weight-Pigment (Rionol Green 2YS) (Toyo Ink Mfg. Co., Ltd. ), CI Pigment Green 36) ... 22 weight Part-Pigment (Seika Fast Yellow 2700) (manufactured by Dainichiseika Kogyo Co., Ltd., CI Pigment Yellow 83) ... 7.5 parts by weight Composition of blue printing ink -Polyester acrylate resin (manufactured by Toagosei Chemical Industry Co., Ltd.) , Aronix M-7100) 70 parts by weight-Diallyl phthalate prepolymer 30 parts by weight Pigment (Chromophtal red A3B) (Ciba Geigy, CI Pigment Red 177) 32 parts by weight Pigment (Seika Fast) Yellow 2700) (manufactured by Dainichiseika Kogyo KK, CI Pigment Yellow 83) 8 parts by weight (formation of black receiving layer) 7059 glass (thickness = 1.1 mm) manufactured by Corning Co., Ltd. is used as a transparent substrate. , The above water-soluble photosensitive resin composition on the substrate by spin coating Coated, then, 70 ° C., the photosensitive resin layer prebaked for 5 minutes conditions (thickness = 0.6 .mu.m) was formed.

Then, after solid exposure with a 2 kW ultra-high pressure mercury lamp and photo-curing, post-baking was carried out at 100 ° C. for 5 minutes to form a water-soluble resin layer (black receiving layer). (Formation of Colored Pixels) The colored pixels were sequentially formed on the black receiving layer by an intaglio offset printing method using a plate having a stripe-shaped recess having a plate depth of 6 μm and a width of 110 μm, and a silicone blanket. . That is, using the coloring ink for printing prepared above, 110
After printing a stripe pattern of μm width, 200 ℃, 30
The colored ink for printing was heat-cured by heating for a minute to form colored pixels of each color. These colored pixels are hydrophobic. Next, the transparent substrate containing the colored pixels was immersed in a 100 ppm palladium chloride aqueous solution (manufactured by Nippon Kanigen, Red Schumer) for 30 seconds, washed with water and dried to obtain the relief containing the catalyst.

This substrate was immersed in a nickel plating solution (BEL-801 manufactured by Uemura Kogyo Co., Ltd.) at 23 ° C. containing a boron-based reducing agent.
It was immersed for a minute, washed with water and dried to form a black layer on the portions other than the colored pixels, and cured at 200 ° C. for 30 minutes.

Further, an indium tin oxide (ITO) film having a thickness of 2000 Å is formed thereon by a sputtering method to form a transparent electrode, and the color filter is TF.
A color liquid crystal display device was manufactured through a liquid crystal using the T substrate as a counter electrode. As a result of driving using the color liquid crystal display device manufactured as described above, it was confirmed that sufficient color development and display contrast were exhibited. Example 2 (Preparation of Water-Soluble Resin) First, as a water-soluble resin, a copolymer of one kind of acrylamide-based monomer (N-mono-substituted acrylamide) and another monomer was used as follows. A water-soluble photosensitive resin composition having a composition was prepared.

N-diacetone acrylamide / acrylamide copolymer: 2.7 parts by weight 4,4′-diazidostilbene-2,2′-disulfonic acid disodium salt: 0.3 parts by weight water: 97 Parts by weight Silane coupling agent (KBE-603, manufactured by Shin-Etsu Chemical Co., Ltd.) ... 0.03 parts by weight (preparation of colored photosensitive resin) Then, as a colored photosensitive resin, a benzyl methacrylate / methacrylic acid copolymer was used. 4- (p-N, N-di (ethoxycarbonylmethyl))
A colored photosensitive resin was prepared by dispersing the following pigments in a photosensitive resin mainly containing -2,6-di (trichloromethyl) -S-triazine.

Benzyl methacrylate / methacrylic acid copolymer (77/23 molar ratio) 30 parts by weight Pentaerythritol tetraacrylate 7.7 parts by weight 4- (p-N, N-di (ethoxycarbonylmethyl)) ) -2,6-Di (trichloromethyl) -S-triazine: 0.3 parts by weight Hydroquinone monomethyl ether: 0.01 parts by weight Ethyl cellosolve acetate: 62 parts by weight 13 parts by weight of the above-mentioned photosensitive resin , Red pigment C.I. I. Pigment Red 177 and C.I. I. Pigment Yellow 83
(Pigment net weight ratio 100: 20) 7 parts by weight and ethyl cellosolve acetate 80 parts by weight were mixed to prepare a red colored photosensitive resin.

Next, 13 parts by weight of the above-mentioned photosensitive resin was mixed with green pigment C. I. Pigment Green 36 and C.I. I. Pigment Yellow 83 mixture (100: 10) (7 parts by weight) and ethyl cellosolve acetate (80 parts by weight) were mixed to prepare a green colored photosensitive resin.

Further, in 13 parts by weight of the above-mentioned photosensitive resin,
Blue pigment C.I. I. Pigment Blue 15: 3 and C.I. I.
Pigment Violet 23 Mixture (100: 5) 7
The mixture was mixed with 80 parts by weight of ethyl cellosolve acetate to prepare a blue colored photosensitive resin. (Formation of Black Receptive Layer) 7059 glass (thickness = 1.1 mm) manufactured by Corning Incorporated was used as a transparent substrate, the above water-soluble photosensitive resin composition was applied onto this substrate by spin coating, and then, Prebaking was performed at 70 ° C. for 5 minutes to form a photosensitive resin layer (thickness = 0.6 μm).

Then, after solid exposure with a 2 kW ultra-high pressure mercury lamp and photo-curing, post-baking was carried out at 100 ° C. for 5 minutes to form a black receiving layer. (Formation of Colored Pixel) On this black receiving layer, a red colored photosensitive resin in which a pigment having the composition prepared as described above is dispersed is applied by a spinner to a film thickness of 2.0 μm, and 70 ° C. Prebaking was performed under the condition of 5 minutes.

Then, by a proximity exposure machine equipped with a 2 kW ultra-high pressure mercury lamp, an exposure dose of 10 mJ / cm ^{2 was applied to} the red colored resin through a photomask having a pattern of colored pixels of the first color. went. The proximity gap amount was set to 100 μm. Then, using an aqueous 0.5% ammonium carbonate solution at room temperature, 4
After spray development for 5 seconds, post-paking is performed at 180 ° C for 5 minutes, and the first colored pixel (red)
Was formed.

Using the green colored photosensitive resin and the blue colored photosensitive resin prepared as described above according to this operation, the second and third colored pixels were formed.

Next, a transparent substrate containing the above-mentioned colored pixels
The catalyst-containing relief was prepared by immersing in a 00 ppm palladium chloride aqueous solution (manufactured by Nippon Kanigen, Red Schumer) for 30 seconds, washing with water and drying.

This substrate was placed at 23 ° C. containing a boron-based reducing agent.
Was immersed in a nickel plating solution (BEL-801, manufactured by Uemura Kogyo Co., Ltd.) for 4 minutes, washed with water and dried to form a black layer on the portions other than the colored pixels, and cured at 200 ° C. for 30 minutes.

Further, a 2000 Å-thick indium tin oxide (ITO) film is formed thereon by a sputtering method to form a transparent electrode, and this color filter is used as a TFT.
A color liquid crystal display device was manufactured through the liquid crystal using the substrate as a counter electrode. As a result of driving using the color liquid crystal display device manufactured as described above, it was confirmed that sufficient color development and display contrast were exhibited.

[0040]

In the present invention, attention is paid to the fact that the hydrophobic pixel does not function as a black receiving layer, and the pattern is formed by the so-called self-alignment method in which the black pattern is regulated by this pixel. , There is no need to consider the pattern accuracy and the alignment accuracy. Further, since the black receiving layer is made of metal black obtained by the electroless plating method, it has an effect of maintaining a sufficient optical density.

Since the present invention does not require plate making of the black receiving layer, there is wide room for selection of materials, and since the self-alignment system is adopted, there is an effect that the alignment can be made highly accurate. And, in addition,
Even if a pixel has a defect or a pinhole, black will be filled as a result, so that a color filter having good image quality can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the method for manufacturing a color filter of the present invention over time.

[Explanation of symbols]

 3, 4, 5 ... Colored pixel layer 11 ... Transparent substrate 21 ... Water-soluble resin layer (black receiving layer) 40 ... Black layer

Claims (2)

[Claims] 1. A water-soluble resin layer is formed on a transparent substrate, a hydrophobic colored pixel layer is formed on the water-soluble resin layer in a predetermined pattern, and the water-soluble resin layer is exposed in the predetermined pattern. Then, an aqueous solution of a metal compound serving as a catalyst for electroless plating is brought into contact with the metal compound so that the metal compound is contained in the exposed portion of the water-soluble resin layer, and thereafter, a black layer is formed by bringing it into contact with an electroless plating solution. A method for manufacturing a color filter, comprising: 2. When forming the hydrophobic colored pixel layer,
The method for producing a color filter according to claim 1, wherein the colored pixel layer is made hydrophobic by performing a heating operation treatment by post-baking after forming the pixel pattern.