JP3027860B2 - Color filter and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-layer type super twisted nematic (STN) liquid crystal display device, a film compensation type liquid crystal display device, a color filter used for a liquid crystal television and the like, and a method of manufacturing the color filter.

[0002]

2. Description of the Related Art There are roughly two types of liquid crystal display devices. One is a simple matrix, the other is TF
This is an active matrix using active elements such as T and MIM. The simple matrix system includes a two-layer STN liquid crystal display device, a film compensation type liquid crystal display device, a ferroelectric liquid crystal device, and the like that have been put to practical use. In each case, a steep threshold characteristic is used, and a flat substrate is required to obtain uniform display characteristics in a display area. That is, similarly high flatness is required for the color filter. Generally, a printing method, a dyeing method, and an electrodeposition method are known as a method for manufacturing a color filter. Recently, a method using a negative color resist has been studied.

[0003]

However, with these color filter manufacturing methods, it has not been possible to manufacture a highly flat and inexpensive color filter. FIG. 1 shows a cross-sectional view of a color filter in which a light-shielding portion between picture elements is formed by overlapping colors. In FIG. 1, a red picture element 102, a blue picture element 103, and a green picture element 104 are formed in a stripe shape on a transparent substrate 101, and an overlapping portion 1 of each picture element is formed.
Reference numeral 05 also serves as a light-shielding layer between picture elements. The step of the overlapping portion between these picture elements is 1 μm to 2 μm, and even if the protective layer 106 is formed, the step of the overlapping portion 105 cannot be filled unless the thickness of the protective layer 106 is very large. Although a method of thickening the protective layer is also being studied, a coating method and a flattening process by polishing are complicated,
This is the cause of high costs.

[0004]

According to the present invention, there is provided a color filter manufacturing method comprising the steps of sequentially forming a plurality of picture elements of a different color made of a negative type color resist on a transparent substrate. A step of forming a color resist of a picture element of a color to be formed last on picture elements of a different color formed earlier and in a gap therebetween;
Coating an oxygen blocking film on the color resist of the picture element of the last color formed, and irradiating light of a desired wavelength from the back surface of the substrate using the picture element of a different color formed before as a photomask. And exposing the color resist of the picture element of the last color to be formed.
Further, the method for producing a color filter of the present invention is a method for producing a color filter, comprising the steps of sequentially forming a plurality of picture elements of a plurality of different colors made of a negative color resist on a transparent substrate. Forming a color resist of a picture element on a picture element of a different color formed before and in a gap between the picture elements, and using the picture element of a different color formed before as a photomask from the back surface of the substrate. A step of exposing the color resist of the picture element of the last color to be formed by applying light having a wavelength of It is characterized by being installed in. Further, the method for manufacturing a color filter of the present invention is a method for manufacturing a color filter having a step of sequentially forming a plurality of picture elements of a plurality of different colors made of a negative color resist on a transparent substrate. Forming a color resist of a blue picture element on the picture element of a different color formed earlier and in the gap between the picture element and the picture element of the different color formed before as a photomask from the back surface of the substrate; A step of exposing the color resist of the blue picture element to be formed last to light irradiated with a UV wavelength-cut light.

[0005]

EXAMPLES In the examples of the present invention, the material of the pigment-dispersed color resist was manufactured by Fuji Hunt Electronics Technology Co., Ltd. This color resist has a trade name of color mosaic, and the blue one is CB
V, CRED for green, CGY for green, and CT for transparent. Since this color resist is made of an acrylic photosensitive resin and causes curing inhibition due to oxygen in the air, it may be necessary to expose it after coating with an oxygen barrier film (trade name CP manufactured by Fuji Hunt Electronics Technology Co., Ltd.) if necessary. desirable. At that time, CBV, CRY, and CGY each show high sensitivity.

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

In the embodiments of the present invention, it is preferable to use CT manufactured by Fuji Hunt Electronics Technology Co., Ltd. as a material used for the transparent protective layer. For example, epoxy, urethane, polyamide, polyimide, etc. Can also be used.

In the embodiment of the present invention, a bar coater, a roll coater or the like can be used as a material coating apparatus, and a spin coater can also be used. Further, it can be applied by a printing method.

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

Although it is desirable to use soda glass for the transparent substrate of the present invention, other glass such as quartz glass,
Organic polymer substrates such as non-alkali glass, polycarbonate, and polyacrylic resin can also be used. Further, there may be an inorganic thin film.

The pattern of the color filter of the present embodiment is in the form of a stripe, but the present invention can be applied even if pixels are divided between colors as in a mosaic type.

Embodiment 1 An embodiment of a method for manufacturing a color filter of the present invention is shown in FIG.
It was shown to.

In FIG. 2, a red color resist CRY 202 is applied on a transparent substrate 201 using a bar coater 203, dried, and then exposed and developed at a desired exposure amount using a glass mask 204 with an ultra-high pressure mercury lamp 205. Thus, a stripe-shaped pattern 206 was formed. Thereafter, firing was performed at a high temperature to obtain a substrate 207.

Next, referring to FIG. 3, a green color resist CGY301 is coated on the substrate 207 with a bar coater 30.
2, and CGY 303 was formed in a stripe shape in the same process as CRY so that the patterns did not overlap, thereby obtaining a substrate 304. The developing solution used was an alkaline developing solution (trade name: CD, manufactured by Fuji Hunt Electronics Technology Co., Ltd.).

Next, in FIG. 4, a color resist CBV 401 is applied to the substrate 304 using a bar coater 402 and dried, and then an oxygen blocking film CP 403 is coated.
Exposure light was supplied from a high-pressure mercury lamp light source at a desired exposure amount via the light source No. 04. At that time, a photomask 405 was also used to limit the pixel area. Thereafter, development and firing are performed, and the substrate 40 is developed.
6 was obtained.

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

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

The effect of the UV cut filter will be described below. In FIG. 6, CRY, CGY, CB
The transmittance on the short wavelength side of V is 601, 602, and 60, respectively.
3 is shown. 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, light 604 near 365 nm is transmitted through CRY. As a result, the CBV on the CRY pattern is exposed,
CBV is slightly formed, and color mixing occurs. Therefore, the spectral transmittance 70 as shown in FIG.
By providing a UV cut filter 1, 702 between the light source and the substrate, most of the light 604 transmitted through the CRY is selectively cut, and color mixing can be prevented. On the other hand, for the CBV, back exposure was performed using a photomask so as to cover the entire area up to the display area. As a result, a flat color filter 503 as shown in FIG. 5 is obtained. (Example 2) Green color resist CG on a transparent substrate
Y was applied, dried and then exposed and developed at a desired exposure using a glass mask to form a stripe pattern. After firing at high temperature, red color resist CRY
Is applied, and the CRY pattern becomes C in the same process as CGY.
CRY was formed so as not to overlap with GY. The developer used was an alkaline developer (trade name: CD, manufactured by Fuji Hunt Electronics Technology Co., Ltd.). Next, after applying and drying a color resist CBV on the above substrate, an oxygen barrier film CP is coated, and high pressure is applied to a side where a pattern is not formed at a desired exposure amount through a UV cut filter in the same manner as in Example 1. Exposure was performed from a mercury lamp light source. Thereafter, development was performed and sintering was performed.

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

Next, an acrylic resin (CT, trade name, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was applied to the substrate as a protective film, dried, and then exposed 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 is applied on a transparent substrate,
After drying, exposure and development were performed at a desired exposure amount using a glass mask to form a stripe pattern. After baking at high temperature, apply green color resist CGY and apply CBV
CGY was formed in the same process as that described above so that the patterns did not overlap. The developer was an alkaline developer (trade name C, manufactured by Fuji Hunt Electronics Technology Co., Ltd.)
D) was used. Next, after applying and drying the color resist CRY on the substrate, the substrate was coated with an oxygen blocking film CP, and exposed from a back surface with a desired exposure amount from a high pressure mercury lamp light source. Thereafter, development was performed and sintering was performed. A color filter having good color characteristics was obtained.

Next, an acrylic resin (CT, trade name, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was applied to the substrate as a protective film, dried, and then exposed 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 CGY is applied on a transparent substrate,
After drying, exposure and development were performed at a desired exposure amount using a glass mask to form a stripe pattern. After baking at high temperature, blue color resist CBV is applied and CGY
A CBV was formed in the same process as that described above so that the patterns did not overlap. The developer was an alkaline developer (trade name C, manufactured by Fuji Hunt Electronics Technology Co., Ltd.)
D) was used. Next, after applying and drying a color resist CRY on the substrate, an oxygen barrier film CP was coated, and back exposure was performed with a desired exposure amount from a high pressure mercury lamp light source. Thereafter, development was performed and sintering was performed. No color mixing was observed, and a color filter having good color characteristics was obtained.

Next, an acrylic resin (CT, trade name, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) was applied to the substrate as a protective film, dried, and then exposed 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 that of Example 4 was obtained even when the order of colors to be formed was red, blue, and green.

(Embodiment 6) The order of colors to be formed is blue,
The same color filters as in Example 4 were obtained in the order of red and green.

[0029]

According to the present invention, a color resist of a picture element of a color to be formed last is formed on a picture element of a different color formed before and in a gap therebetween, and the color resist of the color picture formed before is formed. A flat color filter without color mixture can be formed by exposing a color resist of a picture element of a color to be formed last by irradiating light of a desired wavelength from the back surface of the substrate using the picture element as a photomask. Further, in the present invention, when an oxygen barrier film is formed on a color resist, it is possible to prevent the inhibition of curing of the color resist caused by oxygen in the air. Further, even if there is an oxygen barrier film on the color resist, the exposure is performed from the back surface of the substrate, so that it does not hinder the exposure of the color resist. Further, the present invention simplifies the manufacturing apparatus since it is only necessary to coat the color resist with an oxygen blocking film to block oxygen from the color resist. Also, in the exposing step, when a filter capable of selecting a desired wavelength is provided between the substrate and the light source, light having a wavelength optimal for exposing the color resist can be selected, so that the color resist can be efficiently formed. Curing can be performed. In addition, when a blue pixel is formed at the end and light with a UV wavelength cut from the back surface of the substrate is applied, it is possible to prevent a blue pixel from being formed on a red pixel. Color mixing can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a schematic view of a process of forming a first color.

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

FIG. 4 is a schematic view of a step of forming a third color.

FIG. 5 is a schematic view of a step of forming a protective layer.

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

FIG. 7 is a view showing a 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 portion of picture element 106: Protective layer 201: Transparent substrate 202: CRY 203: Bar coater 204: Photo mask 205: Ultra high pressure mercury lamp 206 : Red stripe pattern 207: Substrate 301: Green color resist CGY 302: Bar coater 303: Green stripe pattern 304: Substrate 401: Blue color resist CBV 402: Bar coater 403: Oxygen blocking 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 the short wavelength side 602: transmittance of CGY on the short wavelength side 603: transmission of CBV on the short wavelength side Rate 604: 365 m vicinity of the light 701: UV cut filter transmittance 702: transmittance of the UV cut filter

Claims (3)

(57) [Claims] 1. A method of manufacturing a color filter comprising a step of sequentially forming a plurality of picture elements of a different color made of a negative color resist on a transparent substrate. Forming an oxygen-blocking film on a pixel of a different color formed before this and in a gap between the pixels; and coating an oxygen-blocking film on a color resist of the pixel of the last color to be formed; A step of exposing the color resist of the picture element of the last color to light of a desired wavelength from the back surface of the substrate using the picture elements of different colors as a photomask. Manufacturing method. 2. A method of manufacturing a color filter comprising a step of sequentially forming a plurality of picture elements of a different color made of a negative type color resist on a transparent substrate. A step of forming on a pixel of a different color formed before this and in a gap between the pixels, and irradiating light of a desired wavelength from the back surface of the substrate using the pixel of a different color formed before as a photomask. Having a step of exposing a color resist of a picture element of the last color to be formed, wherein in the exposing step, a filter capable of selecting a desired wavelength is provided between the substrate and the light source. A method for manufacturing a color filter. 3. A method of manufacturing a color filter comprising a step of sequentially forming a plurality of picture elements of a different color made of a negative type color resist on a transparent substrate. A step of forming on the picture elements of different colors formed before this and in the gaps between them, and irradiating light having a UV wavelength cut from the back surface of the substrate using the picture elements of different colors formed before as a photomask. And exposing the color resist of the blue picture element to be formed last.