JPH10206627A - Color filter and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance utilization efficiency of a material, and improve productivity by reducing a process of lithography by filling ink having a prescribed color in respective ink filling areas by an ink jet system. SOLUTION: A photosensitive resin layer 12 by kneading metal such as chrome or a black organic pigment, is formed on a base board 10, and patterning is performed on prescribed frame bodies 12a. The frame bodies 12a partition ink filling areas 14, and function as a black matrix. Red ink R, green ink G or blue ink B is filled into the ink filling areas 14. This process is performed by an ink jet system, and the ink is delivered from a head 16 arranged so as to be opposed to the ink filling areas 14. A transparent overcoat layer 18 is formed. A transparent conductive thin film 20 is formed on it, and etching is performed, and patterning is performed on electrodes 20a corresponding to the respective ink filling areas 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter used for a liquid crystal display panel and the like and a method of manufacturing the same.

[0002]

BACKGROUND OF THE INVENTION As a method for producing a color filter such as a liquid crystal display panel, there are a printing method, an electrodeposition method, a dyeing method and a pigment dispersion method.

The printing method is a method in which a paint in which a pigment is dispersed in a thermosetting resin is repeatedly applied in three colors by printing, and the resin is thermoset to form a colored layer. This printing method has a simple process but has poor flatness.

[0004] In the electrodeposition method, a patterned transparent electrode is provided on a substrate, and this is immersed in an electrodeposition coating solution containing a pigment, a resin, an electrolytic solution, and the like to electrodeposit a first color. And
This is a method in which this step is repeated three times and finally baked. This electrodeposition method is effective if it is a color arrangement of a stripe pattern because of its excellent flatness, but it is difficult to form a color arrangement such as a mosaic pattern.

[0005] Due to these drawbacks in the printing method and the electrodeposition method, the dyeing method and the pigment dispersion method have been mainly used in the past.

[0006] The dyeing method is a method in which a photosensitive agent is added to a water-soluble polymer material as a dyeing material, exposed to light, patterned by a lithography process, and then immersed in a dyeing solution to obtain a colored pattern.

For example, first, a black matrix is formed on a glass substrate. Then, a dyeing material is added to a water-soluble polymer material so that it is difficult to dissolve in a solvent when exposed to light, and is applied to a substrate on which a black matrix is formed. Next, by exposing and developing only a part of the dyeing material through a mask, patterning is performed so that the dyeing material remains only in the first color region. And
The first coloring layer is formed by immersing the dyeing material in a dyeing solution to dye and fix it. By repeating this process three times, three color filters are formed.

[0008] The color filter produced by this dyeing method has a high transmittance and a bright color, but is inferior in weather resistance, light resistance, heat resistance and moisture absorption.

Japanese Patent Application Laid-Open No. Hei 1-217302 discloses a technique for producing a black matrix by a dyeing method, but is similar to a general dyeing method in that it has poor weather resistance.

Japanese Patent Application Laid-Open No. 7-146406 discloses that an ink receiving layer is formed on a glass substrate on which a black matrix is formed, and the ink receiving layer is dyed by an ink jet method to improve the mass productivity of color filters. A method is disclosed for causing this to occur. This method is also considered to be a kind of dyeing method.

Next, the pigment dispersion method is a method of repeating a process of applying a photosensitive resin in which a pigment is dispersed to a substrate and patterning the substrate to obtain a monochromatic pattern. Whereas the dyeing method was a method of dyeing after patterning the material for dyeing, the pigment dispersion method was
A pre-colored photosensitive resin is applied to the substrate. A color filter manufactured by the pigment dispersion method has a property of high weather resistance.

However, at least 70% or more of the photosensitive resin used in the conventional pigment dispersion method is removed.
There is a major problem in the efficiency of waste material usage.

In the conventional pigment dispersion method, a lithography step is required each time the first, second, and third color regions are formed, which greatly hinders the improvement of mass productivity of color filters. I was

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a color filter and a method for manufacturing the same, which can improve the efficiency of material use and reduce the number of lithography steps to improve productivity. Is to do.

[0015]

According to a method of manufacturing a color filter according to the present invention, a step of forming a light-blocking photosensitive resin layer on a light-transmitting substrate is provided. The method includes a step of patterning a frame defining an ink-filled area, and a step of filling each of the ink-filled areas with ink of a predetermined color by an inkjet method.

A frame formed by patterning a photosensitive resin layer that blocks light and ink filled in an ink filling area defined by the frame are integrated with the substrate to form a color. Become a filter. The frame functions as a black matrix because it partitions ink and blocks light. Each ink-filled area becomes a single color dot for color display by mixing transmitted color light.

According to the present invention, when the photosensitive resin layer is patterned on the frame, only a part of the material is removed and discarded. Disappears. Further, since the patterning step is performed only once, the number of steps can be reduced.

The effective use of such materials has been made possible by the ink jet system. That is, according to the ink jet method, the ink can be filled directly into the ink filled area without performing lithography because the fine area can be filled with the ink accurately. The present invention is a method for obtaining a color filter by directly forming respective color dots using an ink jet method.

Further, according to the present invention, since coloring is carried out directly instead of coloring, the weather resistance is remarkably superior to that of the coloring method.
Moreover, since pigment ink can be used as the ink, it is easy to substitute the pigment dispersion method which is currently mainstream.

According to the present invention, a light-transmitting overcoat layer is formed on the ink filled in the ink-filled area so as to have a flat surface. Forming a transparent electrode. Thus, a color filter used for a liquid crystal display device can be manufactured.

Further, the photosensitive resin layer is hydrophobic,
Preferably, the ink is aqueous. When the photosensitive resin layer is hydrophobic, the frame formed by patterning the photosensitive resin layer also becomes hydrophobic. When the aqueous ink is filled in the ink filling area defined by the hydrophobic frame, the ink is unlikely to overflow into the adjacent ink filling area. In this way, it is possible to prevent the ink filled in the adjacent ink filling areas from being mixed.

The color filter according to the present invention comprises: a light-transmitting substrate; a light-blocking frame formed on the substrate so as to be divided into a plurality of ink-filled regions; And solidified ink.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 (A) to 1
(E) is a figure which shows the manufacturing process of the color filter which concerns on embodiment of this invention. The color filter manufactured by this process has three color dots of red (R), green (G) and blue (B), and is incorporated in a liquid crystal display device.
Enable full color display.

First, as shown in FIG.
The photosensitive resin layer 12 is formed thereon. Here, the substrate 10
As a transparent, non-alkali glass having a size of 300 × 370 cm and a thickness of 1.1 mm is used. The photosensitive resin layer 12 is formed by spin coating a photosensitive resin into which a metal such as chrome or a black organic pigment has been kneaded to a thickness of 2 μm. The photosensitive resin layer 12 can block light from its material and has hydrophobicity.

Next, as shown in FIG. 2B, the photosensitive resin layer 12 is patterned into a predetermined frame 12a. This step is performed by well-known lithography. Since the photosensitive resin layer 12 blocks light and has hydrophobicity, the frame 1
Similarly, 2a blocks light and has hydrophobicity.

The frame 12a is provided with an ink filling area 1 according to the shape or arrangement of each color of a color filter to be manufactured.
Section 4 For example, a 10-inch VGA liquid crystal display panel has a pitch of about 640 × 480 × about 100 μm.
Three (color) 900,000 pixels, that is, about 900,000 ink filled areas 14 are defined. Further, the photosensitive resin is completely removed from the ink filling region 14 by ashing.

The frame 12a functions as a black matrix because it blocks light. Further, since the frame body 12a has hydrophobicity, the filled ink does not easily overflow into the adjacent ink filled area 14.

When the ink filling area 14 is partitioned in this way, the ink filling area 14 is filled with red ink R, green ink G or blue ink B as shown in FIG. This step is performed by an ink-jet method, and ink is ejected from a head 16 arranged to face the ink filling area 14.

The head 16 has been put to practical use for an ink jet printer, for example, and can discharge ink in accordance with the pitch of the ink filling area 14.

For example, the head 16 is driven at a driving frequency of 5
If five ejection openings for ejecting ink at 1 kHz (5000 ejections per second) are arranged in two rows and three drops of ink are ejected into one ink filling area 14, then about 900,000 pixels of 10 The time required for filling the ink into the ink filling area 14 of the substrate for the color filter of the type VGA specification is as follows.
900,000 × 3 drops / (5000 times × 5 pieces × 2 rows) = about 54 seconds. Here, the head 16 is moved to the next ink filling area 14.
The substrate can be filled with the ink in about 2 to 3 minutes even if the time required to move the substrate is considered.

According to the pigment dispersion method or the like, it takes about 10 minutes to form each color by lithography, so that it takes about 30 minutes for one sheet. In comparison with this, in the present embodiment, the filling of the ink is two to three minutes, and the color filter can be formed in a shorter time than in the related art even if the subsequent steps are included.

The inks used in the present embodiment are three types of liquids in which any one of red (R), green (G), and blue (B) coloring materials is uniformly dispersed in a transparent resin. Light of a color (R, G, B) reflected by the coloring material is transmitted. By arranging these three types of ink in accordance with the shape of the ink filling area 14, R, G, and B color dots can be formed.

Next, the composition of the ink used in this embodiment will be shown.

[0034]

[Table 1] When all the ink filling areas 14 are filled with ink, heat treatment is performed to remove the solvent of the ink. This heat treatment is 1
It is preferable to carry out at 10 ° C. for about 10 minutes. Further, since the inks R, G, and B contract when the solvent is removed (see FIG. 1D), it is necessary to fill the ink R, G, and B with an amount sufficient to secure a required color density with a thickness after the contraction. . In the present embodiment, as shown in FIG. 1C, even if the ink is filled to the extent that the ink rises from the frame 12a, the frame 12a has hydrophobicity so that it does not overflow into the adjacent ink filling area 14. Has become. In addition, to secure the color density, 0.7 to
It is preferable that a solidified layer of about 1.2 μm can be formed. Further, after the solidified layer of the ink is formed, the ink may be further ejected in an overlapping manner to increase the layer thickness while improving the color developability.

Next, after washing the substrate 10 with water, FIG.
As shown in (D), a transparent overcoat layer 18 is formed by spin coating. This overcoat layer 1
8 protects the solidified layers of the inks R, G, and B,
It is formed to flatten the surface.

On the overcoat layer 18, a transparent conductive thin film 20 is formed by sputtering, a mask is formed by lithography, and then etching is performed.
As shown in (E), patterning is performed on the electrodes 20a corresponding to the respective ink filled regions 14. The electrode 20a becomes one electrode for driving liquid crystal when incorporated in a liquid crystal display device.

According to the present embodiment, when the photosensitive resin layer 12 is patterned into the frame 12a, only a part of the material is removed and discarded. And no waste. Further, since the patterning step is performed only once, the number of steps can be reduced.

Further, according to the present embodiment, since the coloring is carried out directly instead of dyeing, the weather resistance is remarkably excellent as compared with the dyeing method. Moreover, since pigment ink is used as ink,
It is easy to replace the currently mainstream pigment dispersion method.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, as long as the ink can be applied to an ink jet system, various inks can be used without being limited to the above composition.

[0040]

[Brief description of the drawings]

FIGS. 1A to 1E are diagrams illustrating a process of manufacturing a color filter according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 12 Photosensitive resin layer 12a Frame 14 Ink filling area 16 Head 18 Overcoat layer 20 Conductive thin film 20a Electrode

Claims (4)

[Claims] A step of forming a light-blocking photosensitive resin layer on a light-transmitting substrate; a step of patterning the light-sensitive resin layer into a frame defining a plurality of ink-filled areas; Filling each of the ink-filled areas with ink of a predetermined color by an inkjet method. 2. The method for manufacturing a color filter according to claim 1, wherein a light-transmitting overcoat layer is formed on the ink filled in the ink-filled region so that the surface becomes flat. Forming a light-transmissive electrode on the overcoat layer. 3. The method for manufacturing a color filter according to claim 1, wherein the photosensitive resin layer is hydrophobic, and the ink is water-based. 4. A light-transmitting substrate, a light-blocking frame formed on the substrate so as to be divided into a plurality of ink-filled regions, and an ink filled and solidified in each of the ink-filled regions. , Including color filters.