JPH1195024A - Manufacture of substrate with color filter, and liquid crystal display element using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate with a color filter capable of preventing ink from flowing out to an adjacent picture element in an ink jet system, and capable of forming a uniform colored layer. SOLUTION: A photolysis type resin layer 3 and an ink-repellent agent layer 4 are formed on a masking film 2, and exposure 5 from the reverse side surface of the formed film 2 in the substrate 1 is conducted to form the ink-repellent agent layer 4 only on the upper surface of the film 2, then ink is sprayed by an ink jet system to form a colored layer 6. Exposure 7 from the surface of the masking film 2 side is carried out thereafter to remove the ink-repellent agent layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a substrate with a color filter by forming a light-shielding film on a substrate and coloring a concave portion surrounded by the light-shielding film by an ink jet method, and a liquid crystal display using the same. Related to the element.

[0002]

2. Description of the Related Art In recent years, with the development of personal computers, the color display of liquid crystal display devices has increased, and color filters have been used for that purpose. This color filter is 100
It is necessary to form a fine pattern of 800 × 600 × 3 pixels or 1024 × 768 × 3 pixels at a pitch of about × 300 μm. As a method of manufacturing this color filter, a pigment dispersion method using a photolithography process capable of patterning with high precision is currently the mainstream.

Since this pigment dispersion method uses a photolithographic technique, an expensive photoresist is used, or each step of coating, drying, exposing, developing, and curing the resist is repeated three times for each color. Will be. For this reason, there has been a problem that a large-scale facility is required, the productivity is low due to the photolithography process, and the price of the obtained color filter is high.

For this reason, Japanese Patent Application Laid-Open No. 59-752 discloses a method of manufacturing a color filter which has a simple manufacturing apparatus and high productivity.
No. 05 proposes a method of forming a colored layer by spraying colored ink by an ink jet method.
In the case of performing coloring by the ink jet method, the droplet diameter is several tens of μm, while the pixel of the color filter is approximately several tens of μm on the short side and several hundred μm on the long side.

[0005] For this reason, a uniform pixel can be obtained by previously providing a section for defining the pixel on the glass substrate, and spraying the ink by ink jetting in this section to spread the ink in the section. Furthermore, the above-mentioned proposal indicates that when ink having good wettability to a glass substrate is used, a convex portion serving as a boundary is printed in advance with a substance having poor wettability to the ink.

Japanese Unexamined Patent Application Publication No. Hei 6-347637 proposes using a combination in which the openings are easily wetted by the ink and the light-shielding films constituting the projections are hardly wetted. In the case of the above method, it is very important to control the ink repellency of the convex portions and the ink affinity of the concave portions. If the control is insufficient, for example, when forming a light-shielding film having high ink repellency, the ink repellent contaminates the opening (recess) which should be ink-philic at the same time, and is colored by the ink jet method. Even when the layer is formed, there is a problem that the ink around the pixel is repelled and the color is removed.

Therefore, as a method of accurately controlling the convex portion to be ink-repellent and the concave portion to be ink-philic, for example, after forming a light-shielding film which is a convex portion, an ink-repellent agent is applied, and the ink-repellent agent of the concave portion is etched. Methods have been proposed to increase the quality. As another method, for example, a method in which a resin light-shielding film material is applied on the entire surface of the substrate, followed by applying an ink-repellent agent on the entire surface, and then exposing and developing to impart ink repellency only on the light-shielding film. Proposed.

[0008]

However, in the former method, there is a problem that it is difficult to sufficiently enhance the ink affinity at the corners of the openings, and that the corners are liable to be discolored. Further, it was necessary to use a strong acid such as hydrofluoric acid or a strong alkali such as sodium hydroxide as an etching agent.

In the latter method, although the ink repellency can be controlled relatively accurately, the ink repellent may flow to the openings due to heat and become contaminated. When the colored ink is ejected to the opening by the ink jet method, there is a problem that the solvent in the ink swells the resin light-shielding film.

Therefore, the light-shielding film is unlikely to swell or deform, the ink does not flow to the adjacent pixels even when sprayed by the ink jet method, the ink does not repel at the corners of the concave portion, and the coloring layer becomes uniform. A method for manufacturing a substrate with a color filter has been desired.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a light-shielding film formed on a light-transmitting substrate, and an ink jet system formed in a concave section defined by the light-shielding film. In the method of manufacturing a substrate with a color filter, which forms a colored layer by depositing ink in a concave portion by spraying ink, (A) a step of forming a light-shielding film on the substrate in a specific pattern, (B) a photo-decomposable resin and By applying an ink-repellent agent in this order at least on the light-shielding film, and irradiating light from the surface of the substrate opposite to the surface on which the light-shielding film is formed to perform development, only on the upper surface of the light-shielding film A step of forming an ink-repellent agent layer, (C) a step of forming a colored layer by spraying ink by an ink-jet method, and (D) irradiating light from the light-shielding film side surface and developing the light-shielding film. Remove ink repellent layer And a method for manufacturing a substrate with a color filter.

Further, the present invention provides a liquid crystal display element using a substrate with a color filter formed by the manufacturing method.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a light-shielding film having an ink-repellent agent on an upper surface is formed on a light-transmitting substrate before ink is sprayed by an ink-jet method. The coloring layer is formed by spraying the ink by the method and depositing the ink in the concave portion.

At this time, a light-shielding film is first formed on the substrate in a specific pattern. Next, a photo-decomposable resin and an ink repellent agent are applied in this order at least on the light-shielding film, and the substrate is irradiated with light from the surface opposite to the surface on which the light-shielding film is formed to perform development. Then, the ink repellent agent layer is formed only on the upper surface of the light shielding film. As a result, an ink repellent agent layer can be formed on the upper surface of the light-shielding film that has been sufficiently cured.

Next, ink is sprayed on the concave portions separated by the light shielding film by an ink jet method to form a colored layer. Thereafter, the ink repellent layer on the light-shielding film is removed by irradiating light from the surface on the light-shielding film side and developing.

1 to 3 are cross-sectional views showing steps of a manufacturing method of the present invention. FIG. 2A shows a step of forming a light-shielding film on a substrate in a specific pattern. FIG. 1 (B1) shows a step of applying a photo-decomposable resin on a light-shielding film;
(B2) is a step of applying an ink repellent agent thereon, (B2)
3) shows a step of irradiating light from the surface of the substrate opposite to the surface on which the light-shielding film is formed, and (B4) shows a step of performing development to leave the ink-repellent agent layer only on the light-shielding film. .

FIG. 3C shows a step of forming a colored layer by spraying ink by an ink-jet method.
1) shows a step of irradiating light from the surface on the light-shielding film side, and (D2) shows a step of performing development to remove the ink-repellent agent layer remaining on the light-shielding film.

In each figure, 1 is a substrate, 2 is a light shielding film, 3
Denotes a photo-decomposable resin layer, 4 denotes an ink repellent layer, 5 denotes exposure from the side opposite to the light-shielding film of the substrate, 6 denotes a colored layer formed by an inkjet method, and 7 denotes exposure from the light-shielding film side. .

In the present invention, first, as shown in FIG. 1A, a light-shielding film 2 is formed on a light-transmitting substrate 1 by using a pixel region as an opening. The light-transmitting substrate is not particularly limited as long as the light used for exposure is transmitted, and a glass or plastic sheet or film is preferably used.
The light-shielding film may be formed in a specific pattern from the beginning, or may be formed on the entire surface and then patterned by a photolithography process or the like.

In the present invention, since the coloring layer is formed by the ink jet method, it is preferable that the light shielding film has a certain thickness. That is, the light-shielding film functions as a weir as a convex part, and ink is sprayed by an ink jet method on a concave part surrounded by the weir to form a colored layer. When the weir is formed in this way and the top of the weir is made ink-repellent as in the present invention, a beautiful color filter can be formed in which the sprayed ink is less likely to flow into adjacent pixels.

The thickness of the light-shielding film is preferably substantially the same as the thickness of the coloring layer to be formed.
What is necessary is just to make it about 3 micrometers. Since the light-shielding film is such a thick film, a thick light-shielding film in which a black pigment such as carbon black is mixed in a resin is preferably used. Since such a resin-based light-shielding film may be swollen by the ink forming the colored layer, it is preferable that the resin-based light-shielding film be cured by heating immediately after the formation of the light-shielding film. If there is no problem of swelling, it is also possible to use the heating step for curing the colored layer.

Further, a light-shielding metal film such as chromium or nickel or a thin light-shielding film in which an anti-reflection film such as chromium oxide is laminated thereon is used, and a resin is laminated to increase the thickness. A light-shielding film having the above configuration can also be used.

The light-shielding film is formed on the substrate in the form of a line or a lattice, and the recessed section may be made to correspond to the pixel. For example, when a stripe-shaped color filter is formed, it is formed in a linear shape, and in order to correspond to a square pixel, it is formed in a lattice shape. Since this is appropriately determined depending on the shape of the pixel, various shapes such as a fan shape, a triangular shape, a hexavalent shape, and an arc shape are also conceivable.

Further, in the case of a stripe-shaped pattern, a projection may not be formed in the longitudinal direction, but the periphery of the pixel may be completely surrounded by the projection. In particular, in the case of a mosaic color filter, the periphery of the pixel is surrounded by a convex portion of the light shielding film.

Next, as shown in FIG. 1B, a photo-decomposable resin is applied. The photodecomposable resin is usually applied to the entire surface of the substrate, but may be selectively applied to the light shielding film. In the present invention, the photodecomposable resin is applied to at least a portion where the light-shielding film is present to form the photodecomposable resin layer 3. As the photodecomposable resin, those used as ordinary positive photoresists can be suitably used.

Examples of the method for applying the photodecomposable resin include spin coating, spray coating, roll coating, die coating, dip coating, and screen printing. As the photodecomposable resin, specifically, for example, a resin in which a naphthoquinonediazide compound is blended with a cresol novolak resin is exemplified.

Next, as shown in FIG. 1B2, an ink repellent is applied. This ink repellent agent may be usually applied to the entire surface of the substrate, but may be selectively applied to the light shielding film portion.
Examples of the method for applying the ink repellent include spin coating, spray coating, roll coating, die coating, dip coating, and transfer printing. In the present invention, the ink-repellent agent layer 4 is formed by applying the ink-repellent agent to at least a portion having the light-shielding film. These layers are dried by heating them individually or collectively as necessary.

The ink repellent agent may be any agent having a receding contact angle of 20 ° or more with respect to the color ink for forming pixels, and contains an atom having a low interface energy, such as silicon or fluorine. Compounds.

After that, as shown in FIG. 1B3, exposure 5 is performed from the surface of the substrate opposite to the surface on which the light-shielding film is formed. This exposure may be performed by applying light capable of decomposing the photodecomposable resin. Usually, ultraviolet rays are applied. Light sources for this purpose include a high-pressure mercury lamp, a carbon arc lamp, a xenon lamp, and the like.

FIG. 1B4 shows a state in which development has been performed after exposure. This development is immersed in a developer, rinsed,
A known method such as sequentially performing ultrasonic cleaning and drying can be used. As the developer, for example, an aqueous solution of an inorganic alkali such as sodium carbonate or potassium hydroxide or an aqueous solution of an organic alkali such as ethanolamine is preferably used for a resin which can be alkali-developed.

In the step (B3), the light-shielding film functions as an exposure mask, and the photo-decomposable resin adhering to the portion without the light-shielding film is decomposed by exposure. Therefore, when development is performed,
In the portion where the photodecomposable resin is decomposed, the ink repellent agent laminated thereon is removed together with the decomposed photodecomposable resin.

As a result, a substrate in which the photodecomposable resin layer 3 and the ink repellent agent layer 4 remain only on the light shielding film 2 is formed. Thereby, the ink repellent agent does not remain in the concave portion where the ink is deposited when the ink is sprayed by the inkjet method, and a uniform colored layer can be obtained.

Next, a colored layer forming step shown in FIG. 3C is performed. In this colored layer forming step, the colored layer 6 is formed by spraying ink by an inkjet method. Ink is sprayed on a concave portion surrounded by the light shielding film 2 provided with the ink repellent agent layer 4 on the upper surface. In many cases, the ink is made to have substantially the same thickness as the light-shielding film 2 during drying, and therefore, when the ink contains the solvent immediately after spraying, the ink tends to rise more than the protrusions of the light-shielding film around the concave portions. is there.

Also in this case, since the ink-repellent agent layer 4 is provided on the upper surface of the light-shielding film 2, it is difficult for the ink to flow to the adjacent pixels due to the surface tension. The colored layer is dried or cured by heating or the like as necessary. The color filter is usually formed in three colors of RGB (red, green, blue), but may be formed of two colors or CMY (cyan, magenta, yellow) depending on the application.

As the ink jet system, there are a method in which charged ink is continuously jetted and controlled by an electric field, a method in which ink is completely jetted using a piezoelectric element, and an ink which is heated and intermittently formed by utilizing foaming. Various methods such as an injection method can be adopted.

Further, the ink for forming the colored layer preferably contains a binder component which is cured by heat or light in order to be able to withstand the subsequent development step. Examples of such a binder component include an acrylate derivative and a methacrylate derivative.

Next, as shown in (D1) of FIG. 3, exposure 7 is performed from the surface on which the light shielding film 2 is formed. This exposure may be performed by applying light capable of decomposing the photodecomposable resin. Usually, ultraviolet rays are applied.

FIG. 3D2 shows a state in which development has been performed after exposure. As a result, the photo-decomposable resin adhered to a certain portion of the light-shielding film is decomposed by exposure. Therefore, when the development is performed, the photo-decomposable resin remaining on the light-shielding film 2 is decomposed, and the ink-repellent agent laminated thereon together with the decomposed photo-decomposable resin is also removed.

Thereafter, a substrate with a desired color filter is manufactured through a heat-curing step, if necessary.

Further, if necessary, a coating layer of a resin or an inorganic substance is formed thereon for the purpose of flattening, insulating, improving the adhesion to the electrodes, and the like. Then, ITO (indium tin oxide), tin oxide, and other electrodes are formed thereon.

A liquid crystal display element can be formed by sandwiching a liquid crystal layer between such a substrate with electrodes and a color filter and another substrate with electrodes. Of course, an inorganic or organic overcoat layer may be formed on the electrode, an active element such as a TFT may be arranged on the pixel electrode, or a polarizing film or a retardation plate may be arranged outside the liquid crystal display element. .

[0042]

【Example】

Example 1 A black-colored photoresist (“416S” manufactured by Tokyo Ohka Co., Ltd.) was applied on a light-transmitting glass substrate by spin coating so as to have a target film thickness of 1.5 μm.
Heat treatment was performed at 10 ° C. for 10 minutes. This substrate is exposed to 100 mJ through a photomask, immersed in a designated developing solution for 30 seconds,
After washing with cold water, baking was performed at 230 ° C. for 1 hour, and the height was 1.
A substrate having a light-shielding film of 5 μm and a width of 25 μm was obtained.

A positive resist was applied to the entire surface of the substrate by spin coating, and then a fluorine-based surfactant (“TSL-8233” manufactured by Toshiba Silicone Co., Ltd.) was added to the surface of the substrate using perfluoro (2-butyltetrahydrofuran). After applying a solution diluted to 25% by weight by spin coating,
Preliminary drying was performed at 80 ° C. for 5 minutes.

Thereafter, the surface opposite to the surface on which the light-shielding film is formed is exposed to a back light of 100 mJ by a high-pressure mercury lamp, immersed in a specified developing solution for 30 seconds, washed with cold water, and the ink repellent is applied only on the light-shielding film. A substrate on which a layer was formed was obtained.

The openings (recesses surrounded by the light-shielding film) of the substrate were sprayed by an inkjet method using aqueous RGB three-color pigment inks, and were temporarily dried at 120 ° C. for 5 minutes. Next, the surface on which the light-shielding film is formed is exposed to a surface of 300 mJ by a high-pressure mercury lamp, immersed in a designated developer for 30 seconds, washed with cold water, and baked at 230 ° C. for 1 hour to form a grid-like RGB. A color filter was obtained. Table 1 shows the results.

Example 2 (Comparative Example) As a comparative example, a light-shielding film was formed on a substrate in the same manner as in Example 1. Then, a solution obtained by diluting a fluorine-based surfactant (“TSL-8233” manufactured by Toshiba Silicone Co., Ltd.) to 0.25% by weight with perfluoro (2-butyltetrahydrofuran) is applied by a spin coating method, and then applied at 80 ° C. for 5 minutes. Temporarily dried for minutes.

This substrate was treated with 16 buffered hydrofluoric acid (HF).
An etching treatment was performed for 60 seconds with a treatment solution obtained by diluting a 50% aqueous solution and a 40% aqueous solution of NH ₄ F (1: 6 mixture) to 1%, washed with water, and air-dried. The opening of the substrate obtained in this manner is sprayed with an aqueous pigment ink by an inkjet method, and baked at 230 ° C. for 1 hour.
A lattice-like RGB color filter was obtained. Table 1 shows the results.

In the results shown in Table 1, “○” indicates that there is no defect (good), and “×” indicates that there is such defect (defective). In Example 1 (Example), defects such as outflow of ink to an adjacent pixel portion, color omission in a peripheral portion of a pixel, and uneven color in a pixel did not occur.
On the other hand, in the case of Example 2 (Comparative Example), the spread of the ink to the pixel corners was poor, and the color omission was conspicuous.

[0049]

[Table 1]

[0050]

According to the present invention, the ink repellent agent can be arranged only on the light-shielding film at the time of ink-jet by performing the exposure twice using the photo-decomposable resin and the ink-repellent agent. The resin and the ink repellent can be easily removed. As a result, even when the ink jet method is used, defects such as outflow of ink to an adjacent pixel portion, color loss in a peripheral portion of a pixel, and uneven color in a pixel are less likely to occur.

Therefore, a substrate with a color filter having excellent uniformity can be easily manufactured by the ink jet method having good productivity. The present invention can be applied to various applications within a range that does not impair the effects of the present invention.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a manufacturing process of the present invention.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of the present invention.

FIG. 3 is a sectional view showing a manufacturing process of the present invention.

[Explanation of symbols]

 1: substrate 2: light shielding film 3: photodecomposable resin layer 4: ink repellent agent layer 5: exposure 6: colored layer 7: exposure

Claims (2)

[Claims] 1. A substrate with a color filter, wherein a light-shielding film is formed on a light-transmissive substrate, and ink is sprayed by an ink jet method onto concave portions separated by the light-shielding film to deposit ink in the concave portions to form a colored layer. (A) a step of forming a light-shielding film on the substrate in a specific pattern, (B) applying a photo-decomposable resin and an ink repellent in this order at least on the light-shielding film, the light-shielding film of the substrate Developing by irradiating light from the surface opposite to the surface on which ink is formed to form an ink repellent agent layer only on the upper surface of the light-shielding film, (C) spraying ink by an ink jet method and coloring Forming a layer, and (D) removing the ink-repellent agent layer on the light-shielding film by irradiating light from the surface on the light-shielding film side and developing the substrate. Manufacturing method . 2. A liquid crystal display device using a substrate with a color filter formed by the method according to claim 1.