JPH10268120A - Manufacture of color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter manufacturing method capable of forming a colored picture element involving a less defect through the application of an extremely simplified method, compared with the prior art. SOLUTION: This manufacturing method relates to a color filter with at least three color picture elements formed on a transparent substrate. In this case, the method involves the processes where (1) a dyed layer is formed on a transparent substrate and then a dyeing resistant film is formed on the dyed layer, (2) a laser beam is irradiated to the part of the dye resistant film on the part where the first color picture element of the dyed layer is formed, and only the irradiated part of the dye resistant film is selectively evaporated for removal, and (3) a part for forming the first color picture element of the dyed layer exposed as a result of the evaporation and removal of the irradiated part of the dye resistant film is dyed with the first color dye for forming the first color picture element. The foregoing processes are repeated so as to form the required color picture elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a color filter arranged in a color liquid crystal display,
More specifically, the present invention relates to a method for manufacturing a color filter capable of forming colored pixels with few defects on a transparent substrate by a simple method.

[0002]

2. Description of the Related Art A color liquid crystal display uses a color filter in which pixels of three colors are formed on a transparent substrate. In general, three primary colors of red, blue and green are used as the three colors. If desired, pixels of the fourth color or higher having different hues may be formed, or a black matrix of black may be formed. Conventionally, as one method of manufacturing a color filter, a dyeable layer made of a dyeable polymer material is applied on a transparent substrate, and a dye-resistant resist film is formed thereon in a pattern. There is known a method of dyeing an exposed portion of a layer to be dyed in a desired color. In order to form a dye-resistant resist film in a pattern, a photoresist film may be provided on the layer to be dyed, then subjected to pattern exposure and development. Thereby, a resist film (mask resist film) according to the pattern is formed.
In order to dye the exposed layer to be dyed, the layer to be dyed may be brought into contact with a dye solution containing a dye of a desired color. At the time of dyeing, the portion of the layer to be dyed which is masked by the resist film is not dyed by the dye because the resist film has resistance to dyeing.

[0003] More specifically, as shown in FIG.
A layer 2 to be dyed is formed on the substrate 1, a resist film 3R for red dyeing is formed thereon in a pattern, and the exposed layer 2 to be dyed is dyed with a red dye to form a red pixel 2R. Form. Next, as shown in FIG. 2 (B), after peeling off the red dyeing resist film 3R, as shown in FIG. 2 (C), a green dyeing resist film 3G is formed in a pattern and exposed. The dyed layer 2 is dyed with a green dye to obtain green pixels 2.
G is formed. Next, after peeling off the green dyeing resist film 3G, a blue dyeing resist layer 3B is formed in a pattern as shown in FIG. 2 (D), and the exposed dyed layer 2 is exposed with a blue dye. By dyeing, blue pixels 2B are formed. Finally, as shown in FIG.
B, and red, green, and blue colored pixels (2R, 2G,
2B) obtains a color filter formed on the substrate 1.
In this method, it is necessary to dye the layer to be dyed in one color, peel off the mask resist film used for dyeing the color, and then provide a new mask resist film and dye in another color. . For development and peeling of each mask resist film,
Since a solvent or an alkaline solution is used, there are disadvantages in that the already dyed pixel portion is eroded or the dye is eluted from the pixel. Further, the method of rubbing and removing the mask resist film by a mechanical method has a disadvantage that the surface of the pixel is damaged.

Conventionally, several methods have been proposed to solve the above problems. For example, as shown in FIG. 3A, a layer to be dyed is coated on the entire surface of the semiconductor substrate 1 on which the imaging device is formed, and then a first color, for example, a red pixel 2R to be formed is formed. Only the layer part is cured and left,
The other portion is removed, and the dyed layer portion is dyed red to form a red pixel 2R. Next, as shown in FIG. 3B, the entire surface including the red pixel 2R is coated with a transparent separation layer 4a, and then, as shown in FIG. Thus, a layer to be dyed in which a second color, for example, a green pixel 2G is to be formed, is formed, and the layer to be dyed is dyed green to form a green pixel 2G. As shown in FIG. 3D, the same process is repeated to form a pixel 2B of a third color, for example, blue via the separation layer 4b.

As a method similar to the above, a dyeable resin layer is applied on a transparent substrate, a transparent dye-resistant photoresist film is provided on the resin layer, pattern exposure is performed, and development is performed. Forming a mask resist film according to the pattern, and dyeing the exposed resin layer with a dye having predetermined spectral characteristics to form a dyed layer, and then leaving the mask resist film as a dye-resistant layer. A method of manufacturing a color filter has been proposed in which a next resin layer is formed thereon, and a dye layer having a required number of colors is sequentially formed in the same steps as described below (Japanese Patent Application Laid-Open No. 54-139567). However, these methods do not hurt the colored pixels, but each time a pixel of each color is formed, it is necessary to form a layer to be dyed and a separation layer (mask resist film), so that the process is extremely complicated. .

Further, a method shown in FIG. 4 has been proposed. That is, as shown in FIG. 4A, a layer to be dyed 2 is formed on a semiconductor substrate 1 on which an imaging element is formed, and a photo-decomposition type positive electrode is formed thereon as shown in FIG. A pattern resist is applied and a pattern is formed so as to mask a portion other than a portion that dyes a first color, for example, red, to form a dyeing-resistant mask, that is, a red-stained resist layer 5R. Next, the dyed layer 2
The masked portion, that is, the exposed portion is dyed red to form a red pixel (red filter) 2R. Then, FIG.
As shown in (C), the entire surface including the red pixel 2R and the red-stained resist layer 5R is covered with a photo-decomposable positive resist layer 5, and an optical mask 6 is used to cover the second color, for example, green. The positive resist layer 5 corresponding to the portion to be dyed is exposed. Thereafter, when a developing process is performed, as shown in FIG. 4 (D), the positive resist layer of the dyeable layer 2 where the green color is dyed is chemically removed, and the other portions are covered with the green dye resist layer 5G. It was done. After this,
The exposed portion is dyed green to form a green pixel 2G.
Next, similarly, as shown in FIG. 4E, a blue-stained resist layer 5B and blue pixels 2B are formed. However, although this method does not damage the colored pixels, it is necessary to develop the resist for each color.
It is still a complicated method. In addition, in this method, since there is a developing step, it is necessary to perform a waste liquid treatment of the developing solution, and undissolved substances and dust from the developing solution are mixed in the colored pixels, which causes pixel defects. Become.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a color filter capable of forming a colored pixel with few defects by a method which is extremely simplified as compared with the prior art. . Another object of the present invention is to
It is an object of the present invention to provide a method for manufacturing a color filter which does not require waste liquid treatment of a developer unlike the conventional method using a photoresist. The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, provided a layer to be dyed on a transparent substrate, formed a dye-resistant film thereon, and formed a pattern from above. By irradiating a laser beam to evaporate and remove only the irradiated part of the dye-resistant film, and as a result, repeating the step of dyeing the exposed part of the layer to be dyed with a dye, the desired number of colors can be obtained. Can be formed. According to this method, it is not necessary to form a resist film each time a pixel of each color is formed.
This eliminates the need for repeated development and removal of the resist film, thereby simplifying the process and significantly reducing defects in the formed colored pixels. The present invention has been completed based on these findings.

[0008]

According to the present invention, there is provided a method for manufacturing a color filter in which pixels of at least three colors are formed on a transparent substrate. (1) forming a layer to be dyed on the transparent substrate; Next, a step of forming a dye-resistant film on the layer to be dyed, (2) irradiating a laser light to a portion of the dye-resistant film on a portion of the layer to be dyed on which a pixel of the first color is to be formed. And selectively evaporating and removing only the irradiated portions of the dye-resistant film. (3) The first color pixels of the dyed layer exposed by evaporating and removing the irradiated portions of the dye-resistant film are A step of dyeing a portion to be formed with a dye of the first color to form a pixel of the first color; (4) a dye-resistant layer on a portion of the layer to be dyed on which a pixel of the second color is to be formed; Irradiates laser light to the part of the water-resistant coating and selectively selects only the irradiated part of the dye-resistant coating (5) dyeing a portion of the layer to be dyed which is to be formed by removing the irradiated portion of the dye-resistant film by evaporation and dyeing the second color pixel with a second color dye; Forming a second color pixel;
(6) A portion of the dye-resistant film on a portion of the layer to be dyed on which the third color pixel is to be formed is irradiated with laser light to selectively evaporate only the irradiated portion of the dye-resistant film. Removing, and (7) dyeing a portion of the layer to be dyed which is to be formed by evaporating and removing the irradiated portion of the dyeing-resistant coating and forming a third color pixel with a third color dye, A method of manufacturing a color filter, characterized by forming pixels of at least three colors on a transparent substrate by the steps of forming pixels of a third color.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIG. First, as shown in FIG.
A layer to be dyed 2 is formed on a transparent substrate 1, and a dye-resistant film 3 is provided on the layer to be dyed 2. Examples of the transparent substrate include a transparent thin plate, a sheet, and a film made of glass or a synthetic resin. A substrate on which a black matrix is formed in advance can also be used. The black matrix fills or covers the gaps between the colored pixels with a light-shielding substance, and plays a role in improving the contrast of the color filter. Examples of the material of the black matrix include chromium, a thin film of chromium oxide, carbon black, graphite, and a resin composition mixed with a light-shielding substance. The black matrix may be formed by the same method as forming pixels.

[0010] As the dyeing material for forming the layer to be dyed,
Usually, a natural or synthetic polymer having dyeability is used. Examples of natural polymers include gelatin, glue, casein, and the like, and examples of synthetic polymers include polyvinyl alcohol, polyvinyl pyrrolidone,
Dyeable acrylic resin and the like can be mentioned. The material for forming the dye-resistant coating is not particularly limited as long as it is not dyed when the layer to be dyed is dyed with a dye, and is not dissolved in a coloring solution containing the dye. An acrylic resin, an epoxy resin, a polyurethane resin, a polyimide resin, and the like can be given. The layer to be dyed is formed by applying a solution containing a dyeable material on a transparent substrate by spin coating, roll coating, bar coating, or the like. When the polymer material contains a monomer or a curable component, it is cured after being applied. The thickness of the layer to be dyed can be appropriately determined, but is usually about 0.5 to 3 μm. The dye-resistant film is formed by applying a solution containing the dye-resistant material on the layer to be dyed by spin coating, roll coating, bar coating, or the like. The thickness of the dye-resistant film can be determined as appropriate, but is usually about 0.5 to 3 μm.

Next, as shown in FIG. 1A, a laser light 4 is applied to a part of the dye-resistant film 3 on a part of the layer 2 to be dyed on which a pixel of the first color is to be formed. Thus, only the irradiated portion of the dye-resistant coating 3 is selectively removed by evaporation. Thus, as shown in FIG. 1B, a portion of the layer to be dyed 2 where the first color pixel is to be formed is exposed. The remaining part of the dye-resistant film 3 serves as a mask at the time of dyeing, and protects the underlying layer to be dyed from being dyed. Here, the first color usually means one of the three primary colors required for the color filter, and thereafter, the second color and the third color are the remaining colors, respectively. In general, red, green, and blue (R, G, B) are used as the three primary colors.

The laser beam used here is preferably a laser beam having a wavelength in the ultraviolet region because of its high shape accuracy, and an excimer laser is particularly preferred. That is, the laser beam must have a sufficiently short wavelength so as to cause evaporation of the dye-resistant film when the film is irradiated. Therefore, an excimer laser having a wavelength in the ultraviolet region is preferable. As an excimer laser, Xe
There are Cl, KrF and ArF. Even if the wavelength is infrared light, such as a CO ₂ or YAG laser, it is possible to obtain a wavelength in the ultraviolet region by using the second and third harmonics by using a nonlinear optical material. However, in this case, the laser beam must have a sufficient energy density. The energy density of the laser beam is usually 0.2 to 3
A J / cm ^2, preferably 0.5~2J / cm ^2. If the energy density is too large, not only the dye-resistant film but also the underlying layer to be dyed evaporates. Conversely, if it is too small, the dye-resistant film may not evaporate sufficiently. In order to control the output of the laser light, it is desirable that the laser light be pulse light. This is because processing control in the depth direction of the dye-resistant film can be easily performed by the number of shots of the pulse light.

The size of the formed colored pixel can be appropriately selected according to the purpose.
× 300 μm, and the pixel interval is about 30 μm. There are two methods for irradiating the laser light to the portion of the dye-resistant film above the portion of the layer to be dyed on which the first color pixel is to be formed. One is a method based on surface exposure through a photomask, and the other is a method in which laser light is narrowed down and scanned. Usually, the size of the spot of the laser beam is preferably at least 30 μm or less in either the vertical or horizontal direction of the spot. As a method of scanning the laser light, there is a method of moving the substrate itself by using an XY stage or the like, or a method of scanning the laser light by an optical system. This method does not require a photomask, and is particularly advantageous for fine processing.

Next, a portion of the layer to be dyed, on which the pixel of the first color is to be formed, is dyed with the dye of the first color to expose the portion of the layer to be dyed which has been exposed by evaporation to remove the first color. The pixel of the color eye is formed. In FIG. 1C, as the first color,
An example is shown in which an exposed portion of the dyed layer 2 is dyed using a red dye to form a red pixel 2R. Dyeing is performed by bringing the exposed portion of the dyed layer 2 into contact with a coloring liquid containing a dye. In this case, the contact is preferably performed by immersing the entire substrate in a coloring liquid. The dye to be used is not particularly limited, but in terms of group, acid dyes and reactive dyes are particularly preferable. Chemically,
Examples include azo dyes, phthalocyanine dyes, anthraquinone dyes, triphenylmethane dyes, indigoid dyes, and the like. The dye is fixed as required. As the dye fixing treatment, the entire substrate is put into a 50 to 90 ° C. bath of a tannic acid aqueous solution for 1 to 60 minutes, and then placed in a 50 to 90 ° C. bath of a tartar aqueous solution.
For example, there is a processing by inserting for about 30 minutes.

Next, as shown in FIG. 1 (C), a laser light 4 is applied to a portion of the dye-resistant film 3 on a portion of the layer 2 to be dyed on which a pixel of the second color is to be formed. Only the irradiated portion of the dye-resistant film is selectively evaporated off. A portion of the layer to be dyed, which is to be formed by evaporating and removing the irradiated portion of the dye-resistant film and exposed, is dyed with a dye of the second color to form a pixel of the second color. . In FIG. 1 (D), the exposed dyed layer 2 is colored with a second color liquid containing a green dye and, if necessary, fixed.
An example in which a green pixel 2G is formed is shown. Next, as shown in FIG. 1 (D), a laser light 4 is applied to a part of the dye-resistant film 3 on a part of the layer 2 to be dyed on which a pixel of the third color is to be formed. Only the irradiated portion of the dyeable film is selectively evaporated and removed. A portion of the layer to be dyed, in which the pixels of the third color are to be formed, which is exposed by evaporating and removing the irradiated portion of the dye-resistant film, is dyed with a dye of the third color,
A third color pixel is formed. FIG. 1E shows an example in which the exposed dyed layer 2 is colored with a third color liquid containing a blue dye and, if necessary, fixed to form a blue pixel 2B. I have. Usually, by forming the three color pixels, a color filter is completed as shown in FIG. Further, a protective film may be formed thereon. Examples of the material of the protective film include an epoxy resin, a urethane resin, and a polyimide resin.

[0016]

In the present invention, since it is not necessary to use a resist as the dye-resistant film, there is no erosion of the dyed layer (pixels) due to peeling of the mask resist film, elution of the dye, and no damage.
In addition, since there is no mixing of impurities from the developer, pixel defects can be significantly reduced. Further, according to the method of the present invention, since the developing step is unnecessary, the step can be simplified, and the waste liquid treatment of the developing solution is not required. Even when a resist film is used as the dye-resistant film, the development step is unnecessary because the film is evaporated by laser light.

[0017]

The present invention will be described more specifically with reference to the following examples.

Example 1 As shown in FIG. 1, an acrylic dyeable resin solution [CFR
633DHP: Nippon Kayaku Co., Ltd.] was applied by a spin coater to form a layer 2 to be dyed. This layer 2 to be dyed was exposed and cured by an ultra-high pressure mercury lamp. Next, an epoxy resin was spin-coated on the substrate on which the layer to be dyed was formed to form a dye-resistant film 3. Next, FIG.
As shown in (A), a KrF excimer laser (MPB
(PSX-100) 4 is irradiated with a light 4 through a metal mask (not shown) on a portion where a pixel of the first color is to be formed, and as shown in FIG. The irradiated portion of No. 3 was removed by evaporation and a mask was formed. This whole substrate was used for azo dye PC-Red 136.
It was immersed in a P [Nippon Kayaku Co., Ltd.] solution at 70 ° C. for 10 minutes, washed with water and stained. This was immersed in a 0.3% by weight tannic acid aqueous solution at 70 ° C. for 5 minutes, washed with water, then immersed in a 0.09% by weight aqueous tartar solution at 70 ° C. for 1 minute, and further immersed at 135 ° C. for 50 minutes. 1 second at 185 ° C
It was fixed by heating for 50 seconds, and a red pixel 2R was formed as shown in FIG. Next, FIG.
As shown in (C), a KrF excimer laser (MP
Company B, PSX-100) Light 4 is passed through a metal mask,
Irradiation is performed on the portion where the pixel of the second color is formed, and FIG.
As shown in Table 1, the mask was formed by removing the dye-resistant film by evaporation. This entire substrate was treated with a phthalocyanine dye PC-Green FOP [Nippon Kayaku Co., Ltd.]
After being immersed in the solution at 70 ° C. for 10 minutes, it was washed with water and dyed. This was immersed in a 0.3% by weight tannic acid aqueous solution at 70 ° C. for 5 minutes, washed with water, immersed in a 0.09% by weight aqueous tartar solution at 70 ° C. for 1 minute, and further at 135 ° C. for 50 seconds.
Then, the substrate was fixed by heating at 185 ° C. for 150 seconds to form a green pixel 2G as shown in FIG.

Next, as shown in FIG. 1 (D), a KrF excimer laser (PSX-100 manufactured by MPB) light 4
Was irradiated through a metal mask to a portion where the pixel of the third color was formed, and as shown in FIG. 1E, the dye-resistant film was removed by evaporation. The entire substrate was immersed in an anthraquinone dye PC-Blue 43P [Nippon Kayaku Co., Ltd.] solution at 70 ° C. for 10 minutes, washed with water and dyed. This was immersed in a 0.3% by weight tannic acid aqueous solution at 70 ° C. for 5 minutes, washed with water, immersed in a 0.09% by weight aqueous tartar solution at 70 ° C. for 1 minute, and further immersed at 135 ° C. for 5 minutes.
This was fixed by heating for 0 second and then at 185 ° C. for 150 seconds to form a blue pixel 2B, and as shown in FIG. 1E, a three-color RGB color filter.
The color filter thus obtained had no pixel defects, and when used in a color liquid crystal display, excellent color tone and high contrast could be obtained.

[0020]

According to the color filter manufacturing method of the present invention, the following excellent effects can be obtained. (1) Since the mask layer is not formed or peeled on the dyed pixels, the erosion of the dyed layer due to the development or peeling of the mask resist film, the elution of the dye, and the damage of the pixels, which were problems in the conventional mask dyeing method. Is eliminated. (2) Since the masking layer is formed by partially evaporating the dye-resistant film with laser light, the developing step is unnecessary, and as a result, there is no contamination from the developing solution and the number of pixel defects is reduced. It becomes possible. (3) The pixel forming process can be simplified. (4) No waste liquid treatment of the developer is required.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the steps of an embodiment of the method for manufacturing a color filter of the present invention.

FIG. 2 is a cross-sectional view illustrating a process of an example of a conventional color filter manufacturing method.

FIG. 3 is a cross-sectional view showing another example of the process of the conventional color filter manufacturing method.

FIG. 4 is a cross-sectional view showing another example of the process of the conventional color filter manufacturing method.

[Explanation of symbols]

 1: transparent substrate 2: layer to be stained 3: dye-resistant film 4: laser light 2R: red pixel (red filter) 2G: green pixel (green filter) 2B: blue pixel (blue filter) 3R: red staining Resist coating for 3G: Resist coating for green dyeing 3B: Resist coating for blue dyeing 4a: Transparent separating layer 4b: Transparent separating layer 5R: Resist coating for red dyeing 5G: Resist coating for green dyeing 5B: Resist coating for blue dyeing 6: Photomask A to E: Code indicating process order

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiko Nakamura 2-2, Kamitobakamichocho-cho, Minami-ku, Kyoto, Kyoto Sekisui Chemical Co., Ltd.

Claims (1)

[Claims] 1. A method of manufacturing a color filter, wherein pixels of at least three colors are formed on a transparent substrate. (1) A layer to be dyed is formed on a transparent substrate, and then a dye-resistant layer is formed on the layer to be dyed. Forming a functional film, (2) first of the dyed layer
A step of irradiating a laser light to a portion of the dye-resistant film on a portion where a pixel of a color is to be formed, to selectively evaporate and remove only the irradiated portion of the dye-resistant film; (3) dye-resistant Forming a pixel of the first color by dyeing a portion of the layer to be dyed where the pixel of the first color is to be formed by evaporating and exposing the irradiated portion of the functional film to be exposed, with the dye of the first color;
(4) A portion of the dye-resistant film on the portion of the layer to be dyed on which the pixel of the second color is to be formed is irradiated with laser light to selectively evaporate only the irradiated portion of the dye-resistant film. (5) dyeing a portion of the layer to be dyed which is to be formed by evaporating and removing the irradiated portion of the dyeing-resistant film and exposing the second color pixel with a second color dye; Forming a pixel of the second color, (6) irradiating a laser light to a portion of the dye-resistant film on a portion of the layer to be dyed on which the pixel of the third color is to be formed, (7) the step of selectively evaporating and removing only the irradiated portion, and (7) the third of the dyed layer exposed by evaporating and removing the irradiated portion of the dye-resistant film.
Forming a pixel of the third color by dyeing the portion where the pixel of the color is to be formed with the dye of the third color, thereby forming pixels of at least three colors on the transparent substrate. A method of manufacturing a color filter.