JP3318353B2 - Black matrix substrate and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black matrix substrate and a method of manufacturing the same, and more particularly, to a black matrix substrate having high dimensional accuracy and excellent light-shielding properties, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, monochrome or color liquid crystal displays have attracted attention as flat displays. Liquid crystal displays include an active matrix system and a simple matrix system for controlling three primary colors, and a color filter is used in each system. In a color liquid crystal display, constituent pixel portions are made into three primary colors (R, G, and B), and transmission of each light of the three primary colors is controlled by electrical switching of liquid crystal to perform color display.

[0003] This color filter is constituted by forming a 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 between 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 a light leakage current. For this reason, a higher light-shielding property is required for the light-shielding layer (black matrix). Such a light-shielding layer is required not only for a color liquid crystal display but also for a monochrome liquid crystal display for the same reason.

Heretofore, as a black matrix, a chromium thin film formed by photoetching to form a relief, a hydrophilic resin relief dyed, a relief formed by using a photosensitive liquid in which a black pigment is dispersed, a black electrodeposition paint And those formed by printing.

[0005]

However, although the above-mentioned chromium thin film formed by photoetching to form a relief has high dimensional accuracy, it requires a vacuum film-forming process such as vapor deposition and sputtering, and requires a manufacturing process. Due to the complexity, the production cost is high, and it is necessary to suppress the reflectance of chromium in order to increase the display contrast under strong external light. Had to do. In addition, the above-described method using a photosensitive resist in which a black dye or pigment is dispersed is inexpensive in manufacturing cost, but the photosensitive process is likely to be insufficient because the photosensitive resist is black, and it is difficult to obtain sufficient light-shielding properties. There was a problem that a high quality black matrix could not be obtained. Further, although the formation of the black matrix by the above-described printing method can reduce the manufacturing cost, there is a problem that the dimensional accuracy is low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has high dimensional accuracy that can be used for a flat display such as a liquid crystal display, an imager such as a CCD, or a color filter such as a color sensor. It is an object of the present invention to provide a black matrix substrate having excellent reflectivity and a low reflectance, and a manufacturing method capable of manufacturing such a black matrix substrate at low cost.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a transparent substrate and a particle size formed on the transparent substrate and uniformly dispersed therein. 05
and a light-shielding layer containing light-shielding metal particles of μm .

The present invention also relates to a method for exposing a photosensitive resist layer containing a hydrophilic resin formed on a transparent substrate through a photomask having a pattern for a black matrix.
After developing to form a relief on the transparent substrate, the transparent substrate is brought into contact with an aqueous solution of a metal compound serving as a catalyst for electroless plating, the metal compound is contained in the relief and dried, and then heat treatment is performed. The light-shielding layer having the pattern for the black matrix was formed by bringing the relief on the transparent substrate into contact with an electroless plating solution.

Further, the present invention provides a method for exposing a photosensitive resist layer containing a hydrophilic resin formed on a transparent substrate and a metal compound serving as a catalyst for electroless plating through a photomask having a pattern for a black matrix. dried and developed by washing with water, to form a relief on the transparent substrate is subjected to heat treatment, then, have a black matrix pattern by contacting a relief on the transparent substrate in an electroless plating solution, uniform Metal deposited on the surface
The structure was such that a light-shielding layer containing particles was formed.

[0010]

The black matrix relief formed on the transparent substrate is subjected to electroless plating to deposit a metal to form a light-shielding layer. At this time, since the relief contains a hydrophilic resin, Then, the electroless plating solution sufficiently penetrates into the relief, and metal particles are deposited substantially uniformly in the relief. For this reason, the formed black matrix substrate has a high optical density, a low reflectance, and good dimensional accuracy. Further, since a vacuum process or the like is unnecessary, the manufacturing cost can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of an active matrix type liquid crystal display (LCD) using a black matrix substrate manufactured according to the present invention, and FIG. 2 is a schematic sectional view of the same. 1 and 2, the LCD 1 has a color filter 10 and a transparent glass substrate 20 opposed to each other with a sealing material 30 interposed therebetween, and a thickness of about 5 to 1 made of twisted nematic (TN) liquid crystal therebetween.
A liquid crystal layer 40 having a thickness of about 0 μm is formed.
1 is provided and configured.

FIG. 3 is an enlarged partial sectional view of the color filter 10. In FIG. 3, the color filter 10 includes a black matrix substrate 12 having a light shielding layer (black matrix) 14 formed on a transparent substrate 13, a colored layer 16 formed between the black matrices 14 of the black matrix substrate 12, Matrix 14
And a protective layer 18 and a transparent electrode 19 provided so as to cover the coloring layer 16. The color filter 10 is provided such that the transparent electrode 19 is located on the liquid crystal layer 40 side. The coloring layer 16 includes a red pattern 16R, a green pattern 16G, and a blue pattern 16B, and the arrangement of the coloring patterns is a mosaic arrangement as shown in FIG. Note that the arrangement of the colored patterns is not limited to this, and may be a triangular arrangement, a stripe arrangement, or the like.

Display electrodes 22 are provided on the transparent glass substrate 20 so as to correspond to the respective colored patterns 16R, 16G and 16B. Each display electrode 22 has a thin film transistor (TFT) 24. Further, a scanning line (gate electrode bus) 26 a and a data line 26 b are provided between the display electrodes 22 so as to correspond to the black matrix 14.

In such an LCD 1, each of the colored patterns 16R, 16G, and 16B forms a pixel, and a display electrode corresponding to each pixel is turned on and off in a state where illumination light is emitted from the polarizing plate 51 side. The layer 40 operates as a shutter, and light is transmitted through each pixel of the coloring patterns 16R, 16G, and 16B to perform color display.

The transparent substrate 13 of the black matrix substrate 12 constituting the color filter 10 may be a rigid material such as quartz glass, low expansion glass, soda lime glass, or the like, or a transparent resin film, an optical resin plate, or the like. A flexible material having the above flexibility can be used. Among them, Corning 7059 glass is a material having a low coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the glass. It is suitable for a matrix color filter for LCD.

Here, an example of manufacturing the black matrix substrate 12 according to the present invention will be described with reference to FIG. First, a photosensitive resist containing a hydrophilic resin is applied on the transparent substrate 13 to have a thickness of 0.1 to 5.0 μm, preferably 0.1 to 5.0 μm.
A photosensitive resist layer 3 having a thickness of about 1 to 0.2 μm is formed (FIG. 4A). The coating thickness of the photosensitive resist is 0.1μm
If it is less than 3, the precipitation of metal particles becomes insufficient, and a light-shielding layer having a sufficient optical density cannot be obtained.
If the thickness exceeds 0 μm, the resolution is undesirably reduced.
Further, from the viewpoint of surface irregularities, it is preferable that the coating thickness be 2.0 μm or less. Next, the photosensitive resist layer 3 is exposed through a photomask 9 for a black matrix (FIG. 4B). And the exposed photosensitive resist layer 3
Is developed to form a relief 4 having a pattern for a black matrix (FIG. 4C). Next, the transparent substrate 13 is immersed in an aqueous solution of a metal compound serving as a catalyst for electroless plating, washed with water, dried, and then subjected to a heat treatment (100 to 20).
(0 ° C., 5 to 30 minutes) to give a catalyst-containing relief 5 (FIG. 4D). Then, the catalyst-containing relief 5 on the transparent substrate 13 is brought into contact with the electroless plating solution to form a light-shielding layer, thereby forming a black matrix 14 (FIG. 4).
(E)).

Another example of manufacturing the black matrix substrate 12 according to the present invention will be described with reference to FIG. First, a photosensitive resist containing an aqueous solution of a hydrophilic resin and a metal compound serving as a catalyst for electroless plating is applied on the transparent substrate 13 to form a photosensitive resist layer 7 having a thickness of about 0.1 to 5.0 μm. (FIG. 5 (A)). Next, the photosensitive resist layer 7 is exposed through a photomask 9 for a black matrix (FIG. 5B). Then, after developing and drying the exposed photosensitive resist layer 7, a heat treatment (100 to 100) is performed.
(At 200 ° C. for 5 to 30 minutes) to form a catalyst-containing relief 8 having a pattern for a black matrix (FIG. 5C). Next, the catalyst-containing relief 8 on the transparent substrate 13 is brought into contact with an electroless plating solution to form a light-shielding layer, thereby forming a black matrix 14 (FIG. 5).
(D)).

Examples of the photosensitive resist used in the present invention include natural proteins such as gelatin, casein, glue, ovalbumin, carboxymethylcellulose, polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, and maleic anhydride. For example, a reaction product of a diazonium compound having a diazo group and paraformaldehyde with respect to a polymer and one or a mixture of a plurality of hydrophilic resins such as a carboxylic acid-modified product or a sulfonic acid-modified product of the above resin. Diazo resin, azide compound having an azide group, cinnamate condensed resin obtained by condensing cinnamic acid with polyvinyl alcohol, resin using stilbazolium salt, photo-curable photosensitive group such as ammonium dichromate Also It may be mentioned those obtained by imparting photosensitivity by adding. It is needless to say that the photosensitive group is not limited to the photocurable photosensitive group described above.

As described above, since the photosensitive resist contains the hydrophilic resin, when the catalyst-containing reliefs 5 and 8 come into contact with the electroless plating solution as described above, the electroless plating solution The metal particles can easily penetrate into the catalyst-containing relief, and metal particles can be uniformly deposited in the catalyst-containing relief. Therefore, the formed black matrix 14
Has sufficient blackness and low reflectance, and can solve the problem of reflection by the metal layer in the conventional chromium thin film formation.

The metal compound used as a catalyst for electroless plating used in the present invention includes, for example, chlorides such as palladium, gold, silver, platinum and copper, and water-soluble salts such as nitrates, and complex compounds. The activator solution for electroless plating that has been used can be used as it is.
When such a metal compound is contained in the photosensitive resist as described above, 0.00001 to 0.001% by weight
It is preferable that it is contained to the extent.

The electroless plating solution includes a reducing agent such as hypophosphorous acid, sodium hypophosphite, sodium borohydride, N-dimethylamine borane, a borazine derivative, hydrazine, formalin, etc.
Water-soluble reducible heavy metal salts such as iron, copper, chromium, etc., basic compounds such as caustic soda, ammonium hydroxide, etc. which improve plating speed, reduction efficiency, etc., and inorganic acids, organic acids, etc.
H regulator, buffering agents represented by alkali salts of oxycarboxylic acids such as sodium citrate and sodium acetate, boric acid, carbonic acid, organic acids and inorganic acids, and complexing agents for the purpose of stabilizing heavy metal ions. In addition, an electroless plating solution having an accelerator, a stabilizer, a surfactant and the like is used. Further, two or more 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, which easily forms nuclei (for example, when palladium is used as a metal compound serving as a catalyst for electroless plating), is used. An electroless plating solution containing a hypophosphorous acid-based reducing agent having a high deposition rate can be used.

In any of the above-described methods for producing a black matrix substrate, the light-shielding layer obtained has a wavelength of 545.
The reflectance in nm is at most 30%, usually 5% or less, which is extremely lower than the reflectance (50-80%) of the conventional light-shielding layer made of a chromium thin film, and it is possible to obtain good display quality. it can.

In the light-shielding layer, the metal particles dispersed therein have a maximum particle size of 0.05 μm, usually 0.01 to 0.01 μm.
0.02 μm to form a uniform film without unevenness. In any of the above-described methods for manufacturing a black matrix substrate, a light-shielding layer having an optical density of 3.0 or more can be obtained by changing the plating time. From the point
The optical density is preferably 1.5 or more. When the optical density is 1.5 or less, it does not function sufficiently as a light shielding layer and cannot be used as a black matrix substrate.

Further, the thickness of the light-shielding layer can be freely set by changing the coating thickness of the photosensitive resist. However, as described above, the surface unevenness of the black matrix substrate, the resolution, and the optical density are not sufficient. Therefore, the thickness of the light-shielding layer is 0.1 to 5.0 μm, preferably 0.1 to 2.0 μm.
The range is 0 μm.

The black matrix substrate 1 as described above
The formation of the colored layer 16 composed of the red pattern 16R, the green pattern 16G, and the blue pattern 16B between the two black matrices 14 can be performed according to various known methods such as a dyeing method, a dispersion method, a printing method, and an electrodeposition method. it can.

A protective layer 18 provided to cover the black matrix 14 and the colored layer 16 of the color filter 10
Is to smooth the surface of the color filter 10 and improve the reliability.
And for the purpose of preventing contamination of the liquid crystal layer 40, and can be formed using a transparent resin such as an acrylic resin, an epoxy resin, or a polyimide resin, or a transparent inorganic compound such as silicon dioxide. . The thickness of the protective layer is preferably about 0.1 to 10 μm.

As the transparent common electrode 19, an indium tin oxide (ITO) film can be used. The ITO film can be formed by a known method such as an evaporation method and a sputtering method, and the thickness is preferably about 200 to 2000 °.

Next, the present invention will be described in more detail with reference to experimental examples. (Experimental Example 1) Sample 1 7059 glass (thickness =
1.1 mm) and a spin coating method (rotation speed = 800)
A photosensitive resist having the following composition was applied to the transparent substrate by the following method (rpm), and then dried at 70 ° C. for 5 minutes to form a photosensitive resist layer (thickness = 2 μm). (Composition of photosensitive resist) ・ Aqueous solution of 10% polyvinyl alcohol (Gosenal T-330 manufactured by Nippon Synthetic Chemical) 20 parts by weight ・ 20% aqueous solution of diazo resin (D-011 manufactured by Shinko Giken) ... 0.8 parts by weight ・ Water Next, the photosensitive resist layer was exposed to light via a black matrix photomask (line width = 20 μm). The light source for the exposure is an ultra-high pressure mercury lamp 2 kw,
Irradiated for seconds. Thereafter, spray development is performed using water at room temperature and air drying is performed to obtain a line width 2 for black matrix.
A relief of 0 μm was formed.

Next, this transparent substrate was immersed in an aqueous palladium chloride solution (Red Sumer, manufactured by Nippon Kanigen) for 10 seconds, washed with water, drained, and then subjected to a heat treatment at 150 ° C. for 15 minutes to convert the above-mentioned relief into a catalyst-containing relief. did.

Thereafter, the transparent substrate is immersed in a nickel plating solution containing a boron-based reducing agent at 30 ° C. (nickel plating solution top chemical alloy B-1 manufactured by Okuno Pharmaceutical Co., Ltd.) for 3 minutes, washed with water and dried to form a light-shielding layer (black matrix). Was formed to obtain a black matrix substrate (sample 1). Samples 2 to 4 The thickness of the photosensitive resist layer was set to 1 μm and 4 μm, respectively.
A black matrix substrate (samples 2 to 4) was prepared in the same manner as in sample 1 except that the thickness was set to 10 μm and 10 μm. Sample 5 A photosensitive resist having the following composition was applied by the spin coating method (rotation speed = 800 rpm) using the same transparent substrate as used for Sample 1, and then dried at 70 ° C. for 5 minutes. Thus, a photosensitive resist layer (thickness = 2 μm) was formed. (Composition of photosensitive resist) ・ 10% aqueous solution of polyvinyl alcohol (Gosenal T-330 manufactured by Nippon Synthetic Chemical) 20 parts by weight ・ 20% aqueous solution of diazo resin (D-011 manufactured by Shinko Giken) 0.8 parts by weight ・ Palladium chloride Aqueous solution (Nippon Kanigen Red Schumer): 15 parts by weight Next, the photosensitive resist layer was exposed to light via a black matrix photomask (line width = 20 μm). The light source for the exposure is an ultra-high pressure mercury lamp 2 kw,
Irradiated for seconds. Thereafter, spray development was performed using water at normal temperature, air drying was performed, and a heat treatment was performed at 150 ° C. for 15 minutes to form a catalyst-containing relief having a line width of 20 μm for a black matrix.

Next, a transparent substrate containing boron-containing reducing agent
Immerse in a nickel plating solution at 0 ° C (Okuno Pharmaceutical Nickel plating solution Top Chemialloy B-1) for 20 seconds, and then
Further, it is immersed in a nickel plating solution containing a hypophosphorous acid-based reducing agent at 30 ° C. (a nickel plating solution made by Okuno Pharmaceutical Tsp55 nickel A / C = 1/2) for 2 minutes, washed with water and dried to form a light-shielding layer (black matrix). Thus, a black matrix substrate (sample 5) was obtained. Samples 6 to 8 In addition, the thickness of the photosensitive resist layer was 1 μm and 4 μm, respectively.
Black matrix substrates (samples 6 to 8) were prepared in the same manner as in sample 5, except that the thickness was changed to 10 μm and 10 μm. Comparative Sample 1 As a transparent substrate, Corning 7059 glass (thickness =
1.1 mm), the substrate was immersed in hydrofluoric acid to etch the glass, and the substrate surface was pretreated.
Thereafter, tin ions are adsorbed on the surface of the substrate with stannous chloride and hydrochloric acid, and then palladium chloride treatment and electroless nickel plating are performed in the same manner as in Sample 1, and thereafter, a black matrix substrate (comparative sample) 1) was obtained. Comparative Sample 2 Using the same transparent substrate as used in Sample 1, a photosensitive resist having the following composition was applied by a spin coating method (rotation speed = 200 rpm), dried, and dried to form a photosensitive resist layer (1 μm thick).
m) was formed.

(Composition of photosensitive resist) 10% aqueous gelatin solution: 10 parts by weight 10% ammonium bichromate aqueous solution: 3 parts by weight Next, a photomask (line width) for a black matrix is applied to the photosensitive resist layer. = 20 μm). The light source for the exposure is an ultra-high pressure mercury lamp 2 kw,
Irradiated for seconds. Thereafter, spray development is performed using water at room temperature and air drying is performed to obtain a line width 2 for black matrix.
A relief of 0 μm was formed.

Next, the transparent substrate was heated at 60-70 ° C.
60-120% by weight stannous chloride solution (1N hydrochloric acid)
After immersion in a 0.3% palladium chloride solution (1N hydrochloric acid) at 30 ° C. for 30 to 60 seconds, the substrate was washed with water. Immediately after washing with water, it was immersed in a nickel plating solution (Blue Summer manufactured by Nippon Kanigen Co., Ltd.) at 70 to 80 ° C., and electroless plating was attempted. However, since tin adhered to the entire surface, nickel was applied not only to the relief but also to the entire substrate. It was deposited and a black matrix could not be formed.

Next, for each of the above black matrix substrates (Samples 1 to 8 and Comparative Samples 1 and 2), the optical density OD of the black matrix, the reflectance R at a wavelength of 545 nm, the resolution (line and space), and the light shielding The particle size of the nickel particles deposited in the layer was measured. The measurement results are shown in Table 1.

[0035]

[Table 1]

[0036]

As described in detail above, according to the present invention, the black matrix substrate has a light-shielding layer (black matrix) containing a metal even inside, and this black matrix has an optical density. It is high and has low reflectance and high dimensional accuracy, so the black matrix substrate can constitute a color filter with high reliability and high contrast,
Since a vacuum process or the like is unnecessary, manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an active matrix liquid crystal display using a black matrix substrate manufactured according to the present invention.

FIG. 2 is a schematic sectional view of the liquid crystal display shown in FIG.

FIG. 3 is an enlarged partial cross-sectional view of a color filter used in the liquid crystal display shown in FIG.

FIG. 4 is a process diagram illustrating a method of manufacturing a black matrix substrate according to the present invention.

FIG. 5 is a process diagram illustrating a method of manufacturing a black matrix substrate according to the present invention.

[Explanation of symbols]

 5, 8 catalyst-containing relief 9 photomask for black matrix 10 color filter 12 black matrix substrate 13 transparent substrate 14 black matrix (light-shielding layer) 16 coloring layer 16R, 16G, 16B coloring pattern

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 5/20-5/28

Claims (3)

(57) [Claims] 1. A transparent substrate, and a particle size formed on the transparent substrate and uniformly dispersed therein.
And a light-shielding layer containing light-shielding metal particles of 0.01 to 0.05 μm. 2. A photosensitive resist layer containing a hydrophilic resin formed on a transparent substrate is exposed and developed through a photomask having a pattern for a black matrix to form a relief on the transparent substrate. The transparent substrate is brought into contact with an aqueous solution of a metal compound serving as a catalyst for electroless plating, the metal compound is contained in the relief and dried, and then subjected to a heat treatment.After that, the catalyst-containing relief on the transparent substrate is coated with an electroless plating solution. A method for manufacturing a black matrix substrate, comprising: forming a light shielding layer having a pattern for a black matrix by contacting the light shielding layer. 3. A photosensitive resist layer containing a hydrophilic resin formed on a transparent substrate and a metal compound serving as a catalyst for electroless plating is exposed and developed through a photomask having a pattern for a black matrix, and washed with water. After drying, heat treatment is performed to form a relief on the transparent substrate, and thereafter, the relief on the transparent substrate is brought into contact with an electroless plating solution to have a pattern for a black matrix, and is uniformly deposited. Forming a light-shielding layer containing metal particles for light-shielding.