JPH05313006A - Manufacture of color filter - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a color filter, especially a method of uniforming the light transmittance of each colored picture element so as to reduce the color unevenness of transmitted light. CONSTITUTION:After forming colored picture elements R, G, B on a transparent base 1, the picture elements B are provided with through holes 12 or recessed places, and the picture elements R are provided with through holes 13 or recessed places according to the difference of light transmittance among the picture elements R, G, B of different colors. After forming the picture elements R, G, B of the same thickness on the transparent base 1, the picture elements G are provided with light shading films 16, and the picture elements R are provided with light shading films 17 according to the difference of light transmittance among the picture elements R, G, B of different colors. The difference of light transmittance generated to picture element forming resin films by the thickness distribution of the resin films is dissolved by forming through holes (or recessed places) corresponding to the through holes 12, 13 and light shading films corresponding to the light shading films 16, 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter used in a color liquid crystal display panel, a CCD camera or the like, and more particularly to a method for equalizing the light transmittance of pixels made of a plurality of colored resins.

Liquid crystal display panels have features such as thinness, light weight, and low power consumption, and have been widely used in various fields in recent years, and thus have become larger, more precise, larger in capacity, and color. Display is now required.

[0003]

2. Description of the Related Art FIG. 8 is a sectional view showing a conventional color filter having a uniform pixel thickness, FIG. 9 is a spectrum characteristic diagram of a color filter having a uniform pixel thickness, and FIG. FIG. 11 is an explanatory diagram of a conventional light transmittance adjusting method, and FIG. 11 is an explanatory diagram of a pixel forming resin film and its thickness distribution.

In FIG. 8, the color filter has a black mask pattern 2 made of metallic chromium or the like on a glass substrate 1.
After forming, the red pixel R, the green pixel G, and the blue pixel B are sequentially formed.

In such a color filter, when all pixels R, G, B have the same thickness, their spectral characteristics are shown in FIG. 9 in which the vertical axis represents the light transmittance (%) and the horizontal axis represents the wavelength (nm). As shown in the figure, there is a difference in the transmission wavelength region and the light transmittance. For example, when the light having a wavelength of 380 to 780 nm is irradiated, the spectral characteristics of the pixel R are as shown by the solid line in the figure.
The spectral characteristic is as shown by the one-dot chain line in the figure, and the spectral characteristic of pixel B is as shown by the two-dot chain line in the figure, and pixels R and B are darker than pixel G.

Therefore, conventionally, as shown in FIG. 10, the light transmittance of the pixels R, G, B is made uniform by changing the thickness of the pixels R, G, B according to the light transmittance. Pixel R,
As another method for equalizing the light transmittances of G and B, there is a method of changing the kind and mixing rate of the colorant mixed in the pixel forming resin, but this method requires various trial and error and is not easy. ..

In FIG. 11, (a) is a required portion of the glass substrate.
A perspective view in which a pixel forming resin film is applied to the (display area),
(B) is a side view seen from the arrow W direction of (a), (c) is a side view seen from the arrow L direction of (a), (d) is an explanatory view of the thickness distribution of the resin film, Generally, the resin film 3 deposited on a required portion (display area) of the glass substrate 1 by spin coating becomes thick in the central portion.

An example of such uneven thickness of the resin film 3 is shown in FIG.
As shown in (d), a central area A with a thickness of 2.2 ± 0.05 μm, an area B with a thickness of 2.1 ± 0.05 μm, an area C with a thickness of 2.0 ± 0.05 μm, an area D with a thickness of 1.9 ± 0.05 μm, and a thickness. 1.8 ± 0.05 μm
The pixels formed in the area A are divided into the areas E, and the light transmittance is lower than the pixels formed in the area E.

[0009]

As described above,
Generally, the light transmittance adjustment method of a color filter provided with a large number of pixels of three colors of red (R), blue (B), and green (G) is a method of changing the pixel thickness for each color. Adjustment is impossible, and a step is formed on the surface of the color filter as shown in FIG.

Therefore, when the conventional color filter is applied to the liquid crystal display panel, the unevenness of the color tone of the pixel itself becomes a problem and the unevenness of the display is caused, and the steps of the pixels R, G and B are flattened by the overcoat layer. However, a transparent electrode is formed on top of it, but there is a problem in that the light efficiency is reduced if the overcoat layer is thickened for planarization.

Further, unevenness in the thickness of the pixel forming resin film also occurs, which causes a difference in light transmittance depending on the forming position even in the case of pixels of the same color, which causes unevenness in display on the liquid crystal display panel. There were also points.

[0012]

FIG. 1 is an explanatory view of the basic constitution of a color filter according to the method of the present invention. In FIG. 1A, the color filter 11 is a transparent substrate (glass substrate) 1
After forming the pixels R, G, B on the
The pixel B is provided with a through hole 12 or a recess (not shown) for achieving the same light transmittance as the pixel G according to the difference in light transmittance between the pixels B, and the pixel R has the same light transmittance as the pixel G. A through hole 13 or a recess (not shown) is provided for adjusting the transmittance.

In FIG. 1B, the color filter 15 forms the pixels R, G and B on the transparent substrate (glass substrate) 1 and then determines the difference in light transmittance between the pixels R, G and B having different colors. Accordingly, the pixel G is provided with a light shielding film 16 for making the same light transmittance as the pixel B, and the pixel R is provided with a light shielding film 17 for making the same light transmittance as the pixel B.

As a result, the color filters 11 and 15 according to the method of the present invention have the same color tone of the pixels R, G and B.
Further, in the color filters 11 and 15, the difference in the light transmittance generated in the resin film due to the thickness distribution of the pixel forming resin film is caused by the through holes (or recesses) corresponding to the through holes 12 and 13.
Alternatively, it is solved by forming a light shielding film corresponding to the shielding films 16 and 17.

[0015]

According to the above-described means for forming the through hole or the recess in the pixel, the light transmittance of the pixel is increased by forming the through hole or the recess, and the change amount is the size of the through hole diameter or the recess diameter. Large and small, depending on the depth of the recess.

Therefore, the color difference pixels R, G and B can be made to have the same thickness (steps can be eliminated), and by forming a through hole or a recess in the pixel having a small light transmittance, the same substrate can be formed. The light transmittances of the formed multicolor pixels are equalized. For example, if appropriate through holes 12 and 13 are provided in the pixels B and R, the light transmittance characteristics of the pixels R and B are as shown by the broken line in FIG. The rate changes to increase.

According to the above-mentioned means for forming the light shielding film on the pixel, the light transmittance of the pixel is reduced by forming the shielding film, and the change amount is determined by the size (area) of the shielding film.

Therefore, the color difference pixels R, G and B can be made to have the same thickness (steps can be eliminated), and by forming a shielding film on a pixel having a large light transmittance, a plurality of pixels formed on the same substrate can be formed. The light transmittance of the color pixel changes in a direction in which the light transmittance of the pixel having the shield film is reduced, and becomes equal to that of the pixel having no shield film.

Further, the variation in the light transmittance of the pixel caused by the uneven thickness of the pixel forming resin film can be eliminated by selectively forming the through hole or recess and the light shielding film.

[0020]

FIG. 2 is an explanatory view of a main manufacturing process of a color filter according to a first embodiment of the method of the present invention, FIG. 3 is an explanatory view of a color filter according to a second embodiment of the method of the present invention, and FIG. FIG. 5 is an explanatory view of a color filter according to a third embodiment of the invention method, FIG. 5 is an illustration of a color filter according to a fourth embodiment of the invention method, and FIG. 6 is a color filter according to the fifth embodiment of the invention method. Explanatory drawing, FIG. 7 is explanatory drawing of the adjustment method of the resin film for pixel formation by the method of this invention.

In FIG. 2A, after the black mask pattern 2 is formed on the glass substrate 1, a large number of red pixels R, green pixels G and blue pixels B are sequentially formed with the same thickness.

In FIG. 2B, after the resist layer 21 is deposited on the pixels R, G and B, as shown in FIG. 2C, the optical through hole 22 and the pixel R corresponding to the pixel B are formed. A photomask 24 having an optical through hole 23 corresponding to is superposed on the resist layer 21 and exposed. As a result, the resist layer 21 is exposed to light at the portions where the through holes 22 and 23 face each other.

Then, as shown in FIG. 2D, a photomask is formed.
24 is moved so that the through holes 22 and 23 face the other pixels B and R, and the resist layer 21 is exposed to light. Next, the resist layer 21 is developed except for the photomask 24, and the through holes 12 or 13 are formed in the pixels B and R using the resist mask 25 formed by the development process, as shown in FIG. After that, when the resist mask 25 is removed, as shown in FIG. 2F, the through hole 12 is formed in the pixel B and the through hole 13 is formed in the pixel R.
After that, the color filter 11 in which the light transmittances of the pixels R, G, and B are uniform is completed.

In FIG. 3 in which the black mask pattern 2 is omitted, the color filter 26 is formed between the pixels R, G and B of different colors after the pixels R, G and B having the same thickness are formed on the glass substrate 1. The pixel B has a plurality of through holes (two in the figure) to have the same light transmittance as the pixel G according to the difference in the light transmittance of the pixel B.
27 is provided, and one through hole 27 is provided in the pixel R so as to have the same light transmittance as the pixel G.

The color filter 26 is manufactured in the same manner as the color filter 11, but in the color filter 11, the through holes 12 and 13 having different diameters are used separately,
26 is one type of through hole 27, and the adjustment amount is changed for the pixels B and R depending on the number of through holes 27. Therefore, the diameter of the through hole 27 may be further reduced to form a plurality of through holes in the pixel R and a larger number of through holes in the pixel B than in the pixel R.

In FIG. 4 in which the black mask pattern 2 is omitted, the color filter 31 forms pixels R, G and B having the same thickness on the glass substrate 1 and then the pixels R, G and B having different colors. The pixel B is provided with a recess 32 having the same light transmittance as that of the pixel G, and the pixel R is provided with a recess 33 having the same light transmittance as that of the pixel G according to the difference in the light transmittance.

The color filter 31 is manufactured in the same manner as the color filter 11, but when forming the recesses 32 and 33 using a resist mask, it is troublesome to manage the etching time so as not to penetrate the pixels B and R. On the other hand, in the through holes 12, 13, 27 of the color filters 11 and 26, while a part of the irradiation light passes through the through holes 12, 13, 27, the color filter 31 eliminates such passing light. And the quality of color is better than that of the color filters 11 and 26.

Although the recesses 32 and 33 have the same diameter and different depths in FIG. 4, the recesses 32 and 33 may have the same depth and different diameters. Although the number of each pixel is one, it may be plural, for example, one for each pixel R and one for each pixel B.

In FIG. 5 in which the black mask pattern 2 is omitted, the color filter 36 is formed between the pixels R, G, B of different colors after the pixels R, G, B having the same thickness are formed on the glass substrate 1. The light shielding film 37 is provided on the surface of the pixel G and the light shielding film 38 is provided on the surface of the pixel R in accordance with the difference in the light transmittance of the pixel G.

The color filter 36 includes all pixels R,
A light-shielding layer is deposited on G and B, and the light-shielding layer is selectively etched to form light-shielding films 37 and 38 that do not pass the irradiation light from the back surface of the glass substrate 1.

In FIG. 6 in which the black mask pattern 2 is not shown, the color filter 41 forms pixels R, G and B having the same thickness on the glass substrate 1 and then, between the pixels R, G and B of different colors. A plurality of (two in the figure) light shielding films 42 are provided on the surface of the pixel G according to the difference in the light transmittance of the
An individual light shielding film 42 is provided.

The color filter 41 is a color filter.
The color filter 36 is manufactured in the same manner as the color filter 36, and the relatively large light shielding film 37 is divided into a plurality of parts. That is, when the light shielding film 37 becomes too large, black spots occur in the pixel, whereas the light shielding film 42 can eliminate such black spots.

Next, a method of eliminating the variation in the light transmittance due to the uneven thickness of the resin film 3 described with reference to FIG. 11 will be described with reference to FIG. In the resin film 3 of FIG. 11, the film thickness of the region A is
2.2 ± 0.05 μm, Region B film thickness 2.1 ± 0.05 μm, Region C film thickness 2.0 ± 0.05 μm, Region D film thickness 1.9 ± 0.05 μm, Region E film thickness 1.8 ± 0.05 μm When the light transmittance of the resin film 3 having a thickness of 2.0 μm is 10%, each region A to
The average transmittance of E is as follows: transmittance = e ^-kd where k: light absorption coefficient d: film thickness e: exponential function formula, area A is 8.0%, area B is 9.0%, area C
Is 10.0%, area D is 11.2%, and area E is 12.6%.

Therefore, when a through hole or a shielding film is provided to correct the transmittance of the pixel, for example, when the transmittance of the pixel formed from each region A to E of the resin film 3 is set to 10%, the transmittance of the pixel is corrected. The area ratio of the through-holes or the shielding film for use is [(corrected pixel transmittance)-(resin film transmittance) / (through-hole transmittance)-
(Resin film transmittance)] or [(corrected pixel transmittance)-(resin film transmittance) / (shielding film transmittance)-(resin film transmittance)], the corrected pixel transmittance is 10 %, The resin film transmittance is calculated as follows, assuming that the above-mentioned transmittances and through-hole transmittances of the respective areas A to E are 100% and the shielding film transmittance is 0%.

The pixels formed from the area A are shown in FIG.
As shown in (a), providing the through hole a _-1 of cross sectional area, which corresponds to 2.2% of the area of the pixel 3 _-1. For the pixel formed from the region B, as shown in FIG. 7B, the through hole a having a cross-sectional area corresponding to 1.0% of the area of the pixel 3 _-2.
-2 is provided.

The pixels formed from the area C are not corrected. For the pixel formed from the region D, as shown in FIG. 7C, the light shielding film b _-1 having an area corresponding to 10.7% of the area of the pixel 3 _-3 is provided.

The pixels formed from the area E are shown in FIG.
As shown in (d), the light shielding film b _-2 having an area corresponding to 20.6% of the area of the pixel 3 _-4 is provided.

[0038]

As described above, according to the method of the present invention, it is possible to make a large number of colored pixels have the same thickness, which eliminates the step between pixels, and the present invention can be applied to a color filter of a liquid crystal display panel. When the method is applied, the top coat layer becomes thinner than the conventional one, and the utilization efficiency of transmitted light is improved, and the light transmittance of the pixel due to the variation in the physical properties and thickness of the pixel forming resin is changed to a through hole, a recess, or a light. There is an effect that the display quality is improved by eliminating the conventional color unevenness due to the difference in light transmittance by equalizing with the blocking film.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a basic configuration of a color filter according to the method of the present invention.

FIG. 2 is a main manufacturing process diagram of a color filter according to a first embodiment of the method of the present invention.

FIG. 3 is an explanatory diagram of a color filter according to a second embodiment of the method of the present invention.

FIG. 4 is an explanatory diagram of a color filter according to a third embodiment of the method of the present invention.

FIG. 5 is an explanatory diagram of a color filter according to a fourth embodiment of the method of the present invention.

FIG. 6 is an explanatory diagram of a color filter according to a fifth embodiment of the method of the present invention.

FIG. 7 is an explanatory diagram of a method for adjusting a pixel forming resin film according to the method of the present invention.

FIG. 8 is a cross-sectional view showing a conventional color filter having a uniform pixel thickness.

FIG. 9 is a spectral characteristic diagram of a color filter having a uniform pixel thickness.

FIG. 10 is an explanatory diagram of a conventional light transmittance adjustment method that changes the thickness of a pixel.

FIG. 11 is an explanatory diagram of a pixel forming resin film and its thickness distribution.

[Explanation of symbols]

1 is a transparent substrate (glass substrate) 3 is a pixel forming resin film 3 _{-1 to} 3 _-4 , R, G and B are colored pixels 12, 13 and 27 are through holes formed in the pixels 16, 17, 37, 38 , 42 are light shielding films formed on the pixels 32, 33 are recesses formed on the pixels

Claims (5)

[Claims] 1. A plurality of colored pixels (R, G, B) on a transparent substrate (1).
Are formed for each color, and a through hole (12, 13, 27) having a cross-sectional area corresponding to the difference in light transmittance of the colored pixel (R, G, B) is formed on the pixel (R, B) to be adjusted. A method of manufacturing a color filter, characterized in that it is formed and the light transmittance of the colored pixels (R, G, B) is made uniform by the through holes (12, 13, 27). 2. A plurality of colored pixels (R, G, B) on a transparent substrate (1)
Are formed in different colors and have the same thickness, and the recesses (32, 33) of the cross-sectional area and the depth corresponding to the difference in the light transmittance of the colored pixel (R, G, B) are the pixel to be adjusted. A method for manufacturing a color filter, wherein the color filter is formed in (R, B), and the light transmittances of the colored pixels (R, G, B) are equalized by the recesses (32, 33). 3. A plurality of colored pixels (R, G, B) on a transparent substrate (1)
Is formed for each color, and the light blocking film (16, 17, 37, 38, 42), which is an area corresponding to the difference in light transmittance of the colored pixel (R, G, B), is applied to the pixel to be adjusted ( R, G) formed on the surface, a part of the surface is covered with the light blocking film (16, 17, 37, 38, 42) to form the colored pixel (R, G,
A method of manufacturing a color filter, characterized in that the light transmittance of B) is equalized. 4. A plurality of colored pixels (R, G, B) on a transparent substrate (1)
The pixel to be adjusted (B) to increase the light transmittance by corresponding to the difference in light transmittance of the colored pixel (R, G, B)
The through hole (12, 13, 27) according to claim 1 or the recess (32, 33) according to claim 2 is formed in the pixel, and the pixel (G) to be adjusted for reducing the light transmittance is claimed. Item 3. The light-shielding film (16, 17, 37,
38, 42) to equalize the light transmittances of the color pixels (R, G, B). 5. A transparent substrate (1) is coated with a pixel forming resin film (3), and a plurality of pixels (3 _-1 to 3 _-4 ) are patterned from the resin film (3) to form the resin. A transparent hole is provided in the pixel (3 _-1 , 3 _-2 ) to be adjusted, which increases the light transmittance according to the uneven thickness of the film (3).
(a _-1 , a _-2 ), or a recess is formed, and the pixel (3) to be adjusted that reduces the light transmittance corresponding to the unevenness of the thickness of the resin film (3).
_-3 , 3 _-4 ), the light blocking film (b _-1 , b _-2 ) according to claim 3 is formed to equalize the light transmittance of the plurality of pixels (3 _-1 to 3 _-4 ). A method for producing a color filter, characterized by comprising: