JPH04278901A - Color filter and production thereof - Google Patents

Abstract

PURPOSE:To provide the color filter which is highly flat and inexpensive. CONSTITUTION:Any one color of the red, green and blue of the color filter having red, green and blue picture elements consisting of negative type color resists contg. color materials on a transparent substrate 406 and having at least one layer of transparent protective films is subjected to exposing on the rear surface by casting light of a desired wavelength thereto from the side having no patterns on the substrate 406 with the previously formed picture elements of the two colors as a mash to form a third color between the picture elements of the first color and the second color. Further, a transparent protective film 502 is formed on the picture elements of the three colors and the substrate.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-layer super twisted nematic (STN) liquid crystal display element, a film-compensated liquid crystal display element, a color filter used in liquid crystal televisions, and a method for producing a color filter.

0002

2. Description of the Related Art Liquid crystal display devices are roughly divided into two types. One is simple matrix, the other is TF
This is an active matrix that uses active elements such as T and MIM. Examples of the simple matrix method include two-layer STN liquid crystal display elements, film-compensated liquid crystal display elements, and ferroelectric liquid crystal display elements that have been put into practical use. In either case, steep threshold characteristics are utilized, and a flat substrate is required to obtain uniform display characteristics within the display area. That is, color filters are also required to have high flatness. Generally, printing methods, dyeing methods, and electrodeposition methods are known as methods for producing color filters. recently,
A method using a negative color resist is also being considered.

0003

[Problems to be Solved by the Invention] However, with these color filter manufacturing methods, it has not been possible to manufacture highly flat and inexpensive color filters. FIG. 1 shows a cross-sectional view of a color filter in which the light-shielding portion between each picture element is created by overlapping colors. In FIG. 1, a red pixel 102, a blue pixel 103, and a green pixel 104 are formed in a stripe shape on a transparent substrate 101, and an overlapping portion 1 of each pixel
05 also exists as a light shielding layer between picture elements. The level difference in the overlapped portion between these picture elements is 1 μm to 2 μm, and even if the protective layer 106 is formed, the level difference in the overlapped portion 105 cannot be filled unless the thickness of the protective layer 106 is very large. A method of applying a thick protective layer is also being considered, but the coating method and polishing process are complicated.
This causes high costs.

0004

[Means for Solving the Problems] In order to solve the above problems, the present invention is characterized by the following points. That is, 1)
A color filter consisting of a negative color resist containing at least a coloring material on a transparent substrate and having red, green, and blue picture elements and at least one transparent protective film, the color filter having one color among red, green, and blue. Using the previously formed two-color pattern as a mask, perform backside exposure by applying light of the desired wavelength from the side of the substrate where there are no picture elements, and form a third color between the first and second color picture elements. 2) It is a color filter characterized by having a transparent protective film on the picture elements of three colors and on the substrate. A method for producing a color filter having a picture element and at least one transparent protective film includes: a) applying a color resist to a substrate; b) drying; and c) forming a desired pattern using a glass mask. The photo process of forming, d) developing process, and e) baking process are repeated twice, and the third color is f) the process of applying color resist to the substrate, g) drying process, and h) the previously formed 2 Using the color pattern as a photomask, a step of exposing the substrate to light of a desired wavelength from the back surface where the pattern is not formed, i) a developing step, j) a baking step, and k) a transparent negative resist. The method includes the steps of: coating the color pattern on the substrate having the color pattern, l) drying, m) photolithography for forming a pattern using a glass mask, n) developing, and o) baking. This is a method for manufacturing a color filter.

[0005]

[Example] In the examples of the present invention, the material of the pigment-dispersed color resist was manufactured by Fuji Hunt Electronics Technology Co., Ltd. The product name of this color resist is Color Mosaic, and the blue one is CB.
V, the red one is called CRY, the green one is CGY, and the transparent one is called CT. This color resist is made of acrylic photosensitive resin and its curing is inhibited by oxygen in the air, so if necessary, it may be coated with an oxygen barrier film (product name: CP, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) before exposure. desirable. At that time, CBV, CRY, and CGY each exhibit high sensitivity.

In the embodiments of the present invention, it is preferable to use materials for the pigment-dispersed color resist manufactured by Fuji Hunt Electronics Technology Co., Ltd., but negative-tone materials having similar sensitivity characteristics can also be used. The dye may be dispersed.

In the embodiments of the present invention, the material used for the transparent protective layer is preferably CT manufactured by Fuji Hunt Electronics Technology Co., Ltd., but other materials such as epoxy, urethane, polyamide, and polyimide may also be used. materials can also be used.

In the embodiments of the present invention, a bar coater, a roll coater, or a spin coater may be used as the material coating device. It can also be applied by a printing method.

In this example, an ultra-high pressure mercury lamp was used as the light source for exposure.

Although soda glass is preferably used for the transparent substrate of the present invention, other glasses such as quartz glass,
An alkali-free glass or an organic polymer substrate such as polycarbonate or polyacrylic resin can also be used. Further, there may be an inorganic thin film.

Although the pattern of the color filter of this embodiment is striped, the present invention is also applicable to a mosaic type in which pixels are divided between colors.

(Example 1) An example of the method for manufacturing a color filter of the present invention is shown in FIGS. 2-a to 2-d.

In FIG. 2, a red color resist CRY 202 is applied onto a transparent substrate 201 using a bar coater 203, and after drying, it is exposed to a desired amount of light using an ultra-high pressure mercury lamp 205 using a glass mask 204, and developed. Then, a striped pattern 206 was formed. Thereafter, the substrate 207 was obtained by firing at a high temperature.

Next, in FIG. 3, a green color resist CGY301 is applied onto the substrate 207 using a bar coater 30.
2, and CGY303 was formed in stripes in the same process as CRY so that the patterns did not overlap to obtain a substrate 304. Note that the developer is an alkaline developer (
(trade name: CD manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used.

Next, in FIG. 4, a color resist CBV401 is coated on the substrate 304 using a bar coater 402, and after drying, an oxygen barrier film CP403 is coated, and a UV cut filter 4 is placed on the side where no pattern is formed.
The sample was exposed to light from a high-pressure mercury lamp light source at a desired exposure amount via 04. At that time, a photomask 405 was also used to limit the pixel area. After that, the substrate 40 is developed and baked.
I got 6.

Next, in FIG. 5, an acrylic resin 501 (product name CT, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) is applied as a protective film to the substrate 406, and after drying, the protective film is applied to an area larger than the pattern area of the CBV. In order to form the protective layer 502, exposure was performed using a photomask to form the protective layer 502.

As a result, a highly flat color filter substrate 503 as shown in FIG. 5 was obtained.

The effects of this UV cut filter will be described below. In Figure 6, CRY, CGY, CB
The transmittance on the short wavelength side of V is 601, 602, and 60, respectively.
Shown in 3. In addition, CRY is 330 to 415 nm, C
GY is 330 to 405 nm, CBV is 350 to 42
There is a sensitivity region at 0 nm. Therefore, when light from an ultra-high pressure mercury lamp is irradiated from the back side of the transparent substrate on which CRY and CGY are formed, 604 light of around 365 nm passes through CRY. As a result, the CBV above the CRY pattern is exposed to light, and the CBV
Some BV is formed, resulting in color mixing. Therefore, the spectral transmittance 701 as shown in FIG.
By providing a UV cut filter 702 between the light source and the substrate, most of the light 604 that passes through CRY is selectively cut, and color mixing can be prevented. on the other hand,
Regarding CBV, back exposure was performed using a photomask so as to cover the entire area up to the end of the display area. As a result, a flat color filter 5 as shown in FIG.
03 is obtained. (Example 2) Green color resist CG on a transparent substrate
Y was applied, and after drying, it was exposed to light using a glass mask at a desired exposure amount and developed to form a striped pattern. After firing at a high temperature, a red color resist CRY is applied, and the CRY pattern is converted into CG using the same process as CGY.
CRY was formed so as not to overlap with Y. Note that an alkaline developer (product name: CD, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used as the developer. Next, after coating the above substrate with color resist CBV and drying it, an oxygen barrier film CP is coated, and a high pressure is applied to the side where the pattern is not formed through a UV cut filter in the same way as in Example 1 at a desired exposure amount. Exposure was made from a mercury lamp light source. After that, it was developed and fired.

Regarding CBV, back exposure was performed using a photomask so as to cover the entire area up to the end of the display area. As a result, a flat color filter 406 as shown in FIG. 4 was obtained.

Next, acrylic resin (manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used as a protective film.
CT (trade name) was applied to a substrate, and after drying, it was exposed to light using a photomask to form a protective layer.

As a result, a highly flat color filter 503 as shown in FIG. 5 was obtained.

(Example 3) A blue color resist CBV was applied onto a transparent substrate, and after drying, it was exposed to light using a glass mask at a desired exposure amount and developed to form a striped pattern. After baking at a high temperature, a green color resist CGY was applied, and CGY was formed in the same process as CBY so that the patterns did not overlap. Note that an alkaline developer (trade name: CD, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used as the developer. Next, a color resist CRY was applied to the above substrate and dried, and then an oxygen barrier film CP was coated thereon, and the back surface was exposed to light from a high-pressure mercury lamp light source at a desired exposure amount. Thereafter, it was developed and fired. A color filter with good color properties was obtained.

Next, acrylic resin (manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used as a protective film.
CT (trade name) was applied to a substrate, and after drying, it was exposed to light using a photomask to form a protective layer.

As a result, a highly flat color filter 503 as shown in FIG. 5 was obtained.

(Example 4) A green color resist CGV was applied onto a transparent substrate, and after drying, it was exposed to light using a glass mask at a desired exposure amount and developed to form a striped pattern. After baking at a high temperature, a blue color resist CBY was applied, and CBY was formed in the same process as CGY so that the patterns did not overlap. Note that an alkaline developer (trade name: CD, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used as the developer. Next, a color resist CRY was applied to the above substrate and dried, and then an oxygen barrier film CP was coated thereon, and back exposure was performed using a high-pressure mercury lamp light source at a desired exposure amount. Thereafter, it was developed and fired. A color filter with good color characteristics without color mixing was obtained.

Next, acrylic resin (manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was used as a protective film.
CT (trade name) was applied to a substrate, and after drying, it was exposed to light using a photomask to form a protective layer.

As a result, a highly flat color filter substrate 503 as shown in FIG. 5 was obtained. (Example 5) A color filter similar to Example 4 was obtained by forming the colors in the order of red, blue, and green.

(Example 6) The order of the colors to be formed is blue,
A color filter similar to that of Example 4 was obtained in the order of red and green.

[0029]

Effects of the Invention When a transparent electrode was formed on the color filter of the present invention by sputtering and used as a two-layer STN electrode substrate, a uniform liquid crystal display element with a high light-shielding property with a contrast of 1:20 or more was obtained. I got it.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a color filter in which a light-shielding portion between each picture element is created by overlapping colors.

FIG. 2 is a schematic diagram of the process of forming the first color.

FIG. 3 is a schematic diagram of the process of forming a second color.

FIG. 4 is a schematic diagram of the process of forming a third color.

FIG. 5 is a schematic diagram of the process of forming a protective layer.

FIG. 6 is a diagram showing the transmittance of CRY, CGY, and CBV on the short wavelength side.

FIG. 7 is a diagram showing the spectral transmittance of a UV cut filter.

[Explanation of symbols]

101: Transparent substrate 102: Red picture element 103: Blue picture element 104: Green picture element 105: Overlapping part of picture elements 106: Protective layer 201: Transparent substrate 202:CRY 203: Bar coater 204: Photomask 205: Ultra-high pressure mercury lamp 206: Red stripe pattern 207: Substrate UV cut filter 209: Photomask 301: Green color resist CGY 302: Bar coater 303: Green stripe pattern 304: Substrate 401: Blue color resist CBV 402: Bar coater 403: Oxygen barrier film CP 404: UV cut filter 405: Glass mask 406: Color filter substrate 501: Acrylic resin 502: Protective layer 503: Color filter 601: Transmittance of CRY on short wavelength side 602: Transmittance on the short wavelength side of CGY 603: CBV transmittance on short wavelength side 604: Light around 365 nm

Claims (12)

[Claims] 1. A color filter comprising, on a transparent substrate, red, green, and blue picture elements made of a negative color resist containing a coloring material, and at least one transparent protective film, the filter comprising: Using one of the blue colors as a mask and using the previously formed two-color picture elements as a mask, backside exposure is performed by applying light of a desired wavelength from the non-patterned side of the substrate.
A color filter characterized in that a third color is formed between the first and second color picture elements, and further has a transparent protective film on the three color picture elements and on the substrate. 2. The color filter according to claim 1, wherein the coloring material is fine particles of pigment. 3. The color filter according to claim 1, wherein the coloring material is a dye. 4. In the color filter, a third color is formed over a wider range within a desired range than the outermost periphery of the first and second colors. Color filters listed. 5. The color filter according to claim 1, wherein a protective layer is formed over a wider range within a desired range than the third color. 6. A method for producing a color filter having red, green, and blue picture elements made of a negative color resist containing a coloring material and at least one transparent protective film on a transparent substrate, comprising at least the steps of: Repeating the steps of a) applying a color resist to the substrate, b) drying, c) a photo process of forming a desired pattern using a glass mask, d) developing, and e) baking twice, The third color is f) the process of applying color resist to the substrate, g) the drying process, and h) using the previously formed two-color pattern as a photomask, applying the desired wavelength from the back side of the substrate where the pattern is not formed. A step of exposing to light; i) a step of developing; A method for manufacturing a color filter, comprising m) a photo step of forming a pattern using a glass mask, n) a developing step, and o) a baking step. 7. The method of manufacturing a color filter according to claim 6, wherein the photo step of the method of manufacturing a color filter includes a step of applying an oxygen barrier film on the color resist before exposure. . 8. In the photo step h) of the color filter manufacturing method, a filter capable of selecting a desired wavelength is installed between the substrate and the light source. A method of manufacturing color filters. 9. In the photo step h) of the color filter manufacturing method, a glass mask is also used at the same time so that the third color is formed over a wider area within a desired range than the outermost periphery of the first and second colors. The method for manufacturing a color filter according to claim 6, claim 7, or claim 8, characterized by: 10. The method for producing a color filter according to claim 6, wherein the coloring material is fine particles of pigment. 11. The method for producing a color filter according to claim 6, wherein the coloring material is a dye. 12. In the photo step m) of the color filter manufacturing method, a photomask is used so as to form a protective layer over a wider range within a desired range than the third color. A method for manufacturing a color filter according to claim 9.