JPH0228601A - Production of base plate for color filter - Google Patents

Abstract

PURPOSE:To enable to obtain a gray color film thickness with a same order of thickness as other color film layers without requiring larger thickness than other color layer thicknesses by dyeing a base layer for dyeing for providing a gray color filter after irradiating the base layer with ultraviolet rays. CONSTITUTION:A base material to be dyed with a synthetic dye becomes generally difficultly dyeable by the irradiation with ultraviolet rays, and those dyed with a gray or black dye are often dyed too intensely. But a desired spectral transmission factor is attained with good reproducibility for a base layer 9 to be dyed corresponding to a gray color filter 10, when the treatment of the layer 9 with ultraviolet rays is performed under control. By this constitution, the thickness of the base layer 9 to be dyed is sufficed with an almost same thickness as the thickness of base layer to be dyed to other color, such as green(G), red(R), or blue(B) color filter layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method of manufacturing a color filter substrate used, for example, in a liquid crystal display device.

(Conventional technology) Conventionally, polysilicon, amorphous silicon (a-3i
) and tellurium thin film transistors (ThinFilm
Transistor, T F T >, or MIM (Metal-Insvlator-Metal
Active matrix type liquid crystal display devices using non-linear elements such as ) elements are disclosed in, for example, Japanese Patent Application Laid-Open No. 56-25714 and Japanese Patent Application Laid-Open No. 56-25777, and are widely known.

Regarding this type of liquid crystal display device, a case where TPT is used, for example, will be explained.

That is, this is usually in the form of a TPT provided at each intersection of matrix wiring consisting of a group of signal lines and a group of scanning lines on one substrate, and one of the source electrode or drain electrode of the TPT is connected to the pixel electrode. has been done. Further, on the other substrate, red (R), for example, is applied to the area corresponding to the pixel electrode.
Four color filters of green (G), blue (B), and gray (Gray) are arranged, and the remaining grid-like area is covered with a light-shielding film as a black matrix, and then a counter electrode is formed on the entire surface. And these two
A liquid crystal is sandwiched between the two substrates, and a polarizing plate is provided on the outer surface of each of the two substrates. In this example, multicolor display of 16 colors is possible using four color filters.

Here, a conventional method for forming a color filter having a light-shielding film will be described. First, after cleaning a light-transmitting substrate made of glass, for example, it is placed in a sputtering device, and chromium metal, for example, is deposited to a thickness of 0.1 to 0.2 μm. Subsequently, a resist is applied, exposed and developed using a mask having a predetermined pattern, and after etching, the resist is peeled off to complete the light-shielding film. Next, a photosensitive dyed base material is applied to the entire surface of the light-shielding film forming surface of the light-transmitting substrate,
Exposure is performed using a mask having a predetermined pattern.

Then, the dyed base material in the predetermined opening of the light-shielding film is subjected to a cross-linking polymerization reaction, then developed, and further immersed in a red dyeing tank to perform red dyeing, thereby obtaining a red (R> color filter). By repeating this process three times, green (G), blue (B), and gray color filters are obtained. Note that gray here refers to red (R),
It is a color that is a mixture of green (G) and blue (B) in a predetermined ratio.

(Problem to be Solved by the Invention) By the way, when a gray (Grab) color filter is created by a dyeing method, it is dyed with a gray or black dye, but red (R), green (G) and blue Since the dyeability of the synthetic dyed base material is better than other colors such as (B), the common method is to reduce the thickness of the dyed base material layer and dye it so that the average transmittance is about 50%. It is.

As a result, the following disadvantages have occurred.

■Managing the thickness of the synthetic dye base material layer in the gray color filter becomes troublesome (the allowable range is small).

■Since it is desirable to form a metal light-shielding film on a smooth surface, the formation of this light-shielding film is essentially limited to before forming the color filter, which narrows the degree of selectivity in the process order. .

■For example, when a color filter is used in a liquid crystal display element, the thickness of the synthetic dyed base material layer becomes thinner only in the areas corresponding to gray (Gray).
) and the caps of the parts corresponding to blue (B) are different.

This invention was made in view of such conventional circumstances.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a structure in which a light-shielding film is formed on a light-transmitting substrate so as to have openings with a predetermined regularity, and a dyeing base is placed in the openings. This is a method for manufacturing a color filter substrate in which a color filter of two or more colors including at least gray is obtained by providing a material layer and dyeing the material layer, and the dyed base material layer becomes a gray color filter. is dyed after irradiation with ultraviolet light.

(Function) This invention focuses on the phenomenon that a synthetic dyed substrate becomes difficult to be dyed by irradiation with ultraviolet rays. The reason why this phenomenon occurs is thought to be that the functions of molecules that contribute to dyeing in the synthetic dyed substrate are partially impaired by ultraviolet rays.

Therefore, by utilizing this phenomenon, gray (Gra
It became possible to make the thickness of the dyed base material layer of the color filter b) comparable to the thickness of the dyed base material layers of other colors.

(Example) The details of this invention will be explained below with reference to the drawings.

FIG. 1 is a diagram for explaining the manufacturing process of an embodiment of the present invention. First, as shown in FIG. 1(a), a photosensitive dyed substrate 2 is placed on a light-transmissive substrate 1 made of glass, for example.
1.0 to 1.4μ with a spinner or roll coater
Apply to a thickness of m. Here, the photosensitive dyeing base material 2 is preferably a synthetic product that has better dyeing properties than natural proteins (gelatin or casein), and JDS-509 (manufactured by Nippon Synthetic Rubber) or R633L1 (manufactured by Nippon Kayakumi) is suitable. ing. Next, the photosensitive dyed substrate 2 is exposed to light using a mask, that is, the photosensitive dyed substrate 2 is irradiated with ultraviolet light, and a latent image 3 of the photosensitive dyed substrate 2 is formed by a crosslinking reaction as shown in FIG. 1(b). . Subsequently, the photosensitive dyed substrate 2 is developed to form a resin film 5 having openings 4 with a predetermined regularity, as shown in FIG. 1(C).

Through this development step, the thickness of the resin film 5 is approximately 0.8 to 1.1 μm (remaining film rate approximately 8
0%). After post-baking the resin film 5, black 181 (manufactured by Nipponka Yakumi Co., Ltd.) is used as a dye.
0.25% and acetic acid 1°0% as a reagent (pH is about 3)
The sample was immersed in a black staining bath containing 200 ml of water and stained at 60'C for 20 minutes. In this manner, a dyeing process is performed to form a light shielding film 6 as shown in FIG. 1(d). This light-shielding film 6 becomes thicker than the resin film 5 by adsorbing the dye.

For example, when the optical density is about 2, it reaches 1.5 μm, and when the optical density is about 2.5, it reaches 2.0 μm. and,
FIG. 2 is a diagram showing the spectral transmittance of the light-shielding film 6 dyed so that the optical density is about 2.5, and the vertical axis is the transmittance (
%), and the horizontal axis represents wavelength (nm). As can be seen from the figure, the light shielding film 6 can sufficiently shield light of each wavelength from 400 to 700 nm.

Next, add 5% to a solution containing 1% each of tannic acid and tartarite.
After performing a fixing treatment by dipping at 0'C for 1 minute, a photosensitive dyed substrate 7 having a thickness of 1.0 to 1.4 μm is applied to the entire surface as shown in FIG. 1(e). Next, by irradiating ultraviolet rays using a predetermined exposure mask, the photosensitive dyed substrate 7 in the predetermined opening portion, that is, the portion corresponding to the gray color filter, is subjected to a crosslinking polymerization reaction, and the first A latent image 8 as shown in Figure (f) is obtained. Then, by developing with a developer, a dyed base material layer 9 having an island pattern as shown in FIG. 1(q) is obtained. Subsequently, this dyed base material layer 9
Post-bake and irradiate with ultraviolet rays to achieve full dyeability. Here, for ultraviolet irradiation treatment, a low-pressure mercury lamp with a peak wavelength of 254 nm has a greater treatment effect than an ultra-high-pressure mercury lamp with a peak wavelength of 365 nm.
The treatment is performed for about 10 to 20 minutes with an energy of 5 mw/a/l. Next, 0.25% of Black 181 (manufactured by Nippon Herbal Pharmaceuticals) was used as a dye and 1111.0% of vinegar (p
The dyed base material layer 9 that has been subjected to ultraviolet irradiation treatment is immersed in a black dyeing tank containing 3) h is approximately 3), and dyed at 35°C for 5 minutes to obtain a gray color (Grab )
A color filter 10 is obtained. Next, gray (Gra
As the fixing treatment of the color filter 10 in y), it is immersed in a solution containing 1% each of tannic acid and tartarite at 50° C. for 1 minute. And Figure 3 is gray (Gra')/)
It is a diagram showing the spectral transmittance of the color filter 10 of
As in Figure 2, the vertical axis is transmittance (%), and the horizontal axis is wavelength (nm).
). As can be seen from the figure, the spectral transmittance of this color filter 10 is about 50% on average in the visible range, and the desired gray color is obtained.

Next, by repeating the treatments shown in FIG. 1(e) to FIG. 1(h) three times (excluding the ultraviolet irradiation treatment), the green color ( G), red (
R) and blue (B) color filters 11 to 13 are formed to obtain a desired color filter substrate. here,
The staining conditions for green (G), red (R) and blue (B) are as follows. That is, green (G) color filter 1
1 is CFGll (manufactured by Nippon Herbal Medicine U) 0.2 as a dye.
Dye by immersing in a green dye bath containing 5% at 70° C. for 20 minutes. In addition, the red (R> color filter 12 is
The sample is dyed by immersing it in a red dyeing tank containing 0.25% R136P (manufactured by Nippon Kagami Co., Ltd.) as a dye for 20 minutes at 70°C. Furthermore, the blue (B) color filter 13 is dyed by immersing it in a blue dyeing bath containing 0.25% of 843P (manufactured by Nippon Kayaku II) as a dye at 60° C. for 20 minutes. This is a diagram showing the spectral transmittance of color filters 11 to 13 dyed green (G), red (R), and blue (B), where the lines connecting the X, O, and O marks are green (G), respectively.
In addition to corresponding to red (R) and blue (B), the vertical axis is the transmittance (%) and the horizontal axis is the wavelength (n
m). As shown in the same figure, green (G),
The peaks of the spectral transmittance of the red (R) and blue (B) color filters 11 to 13 are around the wavelength of 550 nm, respectively.
It exists at a wavelength of 620 nm or later and near a wavelength of 450 nm, and the desired green, red, and blue colors are 1q.

In this example, the dyed base material layer 9 corresponding to the gray color filter 10 is subjected to ultraviolet irradiation treatment before dyeing in order to adjust the dyeability. As a result, the dyed base material layer 9 corresponding to the gray color filter 10 is different from the color filters 11 to 1 of other colors.
A desired spectral transmittance can be obtained with a thickness comparable to that of the dyed base material layer 9 corresponding to No. 3. In addition, synthetic dyed substrates generally have excellent dyeability, and when dyed with gray or black dyes, there is often excessive dyeing, but gray (G
By adjusting the ultraviolet irradiation treatment, the dyed base material layer 9, which corresponds to the color filter 10 of R.A.B.

FIG. 5 is a schematic sectional view showing an example of a liquid crystal display device using the two color filter substrates 20 obtained in this example, and a method for forming this will be explained using the same figure. That is, the overcoat layer 2 of the color filter substrate 20
A common electrode 22 made of a transparent conductive film is formed on the substrate 1, and a matrix wiring 24, a pixel electrode 25, and a switching element (not shown) are newly formed on the light-transmissive substrate 23.
An array substrate 26 on which the following elements are formed is prepared.

Here, the level difference on the surface of the color filter substrate 20 is
Due in part to the function of the overcoat layer 21 as a smoothing layer, the thickness is 0.5 μm or less. Then, the color filter substrate 20 and the array substrate 26 are stacked so that the color filters 10 to 13, the pixel electrodes 25, and the light shielding film 6 and the matrix wiring 24 face each other. to hold. Furthermore, by covering the outer surfaces of the color filter substrate 20 and the array substrate 25 with polarizing plates 28 and 29, a desired liquid crystal display device can be obtained. When displaying, for example, from the color filter substrate 20 side It is best to provide lighting.

This liquid crystal display device has 10 color filters for each color.
Since the variation in film thickness between the color filter substrate 20 and the array substrate 26 is reduced, the variation in the cap between the color filter substrate 20 and the array substrate 26 is also reduced. As a result, for example, display color unevenness is reduced, and display characteristics are improved.

In addition, regarding the dye used, for example, gray (Gray)
When it is desired to reduce the transmittance of the blue edge region of the color filter 10 compared to the above embodiment, about 10% by weight of the red dye R136P may be added to the black 181. In addition, the dye 84 used for the blue (B) color filter 13
Since 3P is not necessarily strong against ultraviolet rays, it is desirable to mix an additive that absorbs ultraviolet rays of 400 nm or less into the photosensitive dyed base material in advance. Furthermore, in consideration of the reproducibility of dyeing the color filters 10 to 13 of each color, a predetermined smoothing layer is provided instead of the fixing treatment between the formation of the light shielding film 6 and the formation of the dyed base material layer 9. Needless to say, it's a good thing. Further, the light-shielding film 6 may be made of metal, and in this case, unlike the conventional method, the light-shielding film 6 can be formed even after the color filters 10 to 13 of each color are formed, improving the degree of freedom in the manufacturing process. .

[Effects of the Invention] In this invention, the dyed base material layer that becomes a gray color filter is subjected to ultraviolet irradiation treatment before dyeing, so the thickness of this dyed base material layer is changed to another color, such as green (G). , the thickness can be made comparable to the thickness of the dyed base material layer that becomes red (R) and blue (B), and for example, when used in a liquid crystal display device, it is possible to reduce display unevenness caused by variations in cell gap. can.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view for explaining the manufacturing process of an embodiment of the present invention, FIG. 2 is a diagram showing an example of the spectral transmittance of a light-shielding film in this invention, and FIG. 3 is a gray (
Figure 4 shows an example of the spectral transmittance of a color filter for green (G) and red (R) in this invention.
FIG. 5 is a cross-sectional view showing an example of a liquid crystal display device obtained using an embodiment of the present invention. 1... Light-transmissive substrate 4... Opening 6... Light shielding film 9... Dyeing material layer 10... Gray color filter

Claims (1)

[Claims] a light-transmitting substrate; a light-shielding film formed on the light-transmitting substrate to have openings with a predetermined regularity; and at least a gray color formed by dyeing a dyed base material layer in the openings. A method for manufacturing a color filter substrate comprising two or more color filters including color filters, wherein the dyed base material layer that becomes the gray color filter is dyed after being irradiated with ultraviolet rays. Method.