JPH09258016A - Color filter substrate and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high quality color filter substrate which is capable of expanding visual field angle, free from blurring of color unequal color, etc., and to provide a process for producing the color filter substrate which enables mass production in a simplified stage. SOLUTION: The color filter substrate 10 is constituted by forming light shielding layers 2 of prescribed patterns on a transparent substrate 1, forming recessed color pixel parts 3 of a prescribed depth in the surface part of the transparent substrate 1 exclusive of these light shielding layers 2 and forming the color filter layers 4 on the color pixel parts 3. This process for production comprises forming a thin-film layer on the surface of the transparent substrate 1, then subjecting the thin-film layer and the transparent substrate 1 to etching arriving at the prescribed depth from the surface of the transparent substrate in the prescribed patterns, thereby forming the remaining thin-film layers as the light shielding layers 2 and forming recessed parts (color pixel parts 3) on the surface of the transparent substrate 1 exclusive of the light shielding layers 2, then applying the color filters on these recessed parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter substrate incorporated in, for example, a color liquid crystal display device and a method for manufacturing the color filter substrate.

[0002]

2. Description of the Related Art As a color filter substrate incorporated in a color liquid crystal display device, the one shown in FIG. 3D is known. In this color filter substrate 30, a light shielding layer 12a made of a thin film of Cr, Ta or the like is formed on the surface of the glass substrate 11, and a color filter layer 15 is applied to the surface of the glass substrate 11 excluding the light shielding layer 12a. There is. Further, an overcoat layer 16 is formed on the light shielding layer 12a and the color filter layer 15 so as to cover them, and an ITO film 17 is formed on the overcoat layer 16.

FIGS. 3A to 3D are schematic cross-sectional views showing a method for manufacturing the color filter substrate 10 with time. First, on the surface of the glass substrate 11, Cr or Ta
To form the thin film layer 12 [FIG.

Next, a photosensitive resist 13 is applied on the thin film layer 12 [FIG. Thereafter, the applied photosensitive resist 13 is exposed and developed, and then the thin film layer 12 is etched based on the pattern, and then the photosensitive resist 13 is peeled off, so that the remaining thin film layer is used as the light shielding layer 12a. At the same time, the color pixel portion 14 for forming the color filter layer 15 is formed on the surface of the glass substrate 11 excluding the glass substrate 11 immediately below the light shielding layer 12a. [FIG. (C)].

Next, red (R), green (G), and blue (B) color filters are selectively applied to the color pixel portions 14 to a predetermined thickness (usually about 2 μm). To form the color filter layer 15 by
Light-shielding layer 12a and color filter layer 15 as protective films
The desired color filter substrate 30 is formed by laminating the overcoat layer 16 covering the above and the ITO film 17 on the overcoat layer 16 [FIG. (D)].

[0006]

In the conventional color filter substrate 30 described above, since the color filter layer 15 is formed on the color pixel portion 14 on the surface of the glass substrate 11,
A relatively large step (about 2 μm, which corresponds to the difference between the thickness of the color filter layer 15 and the thickness of the light shielding layer 12a) occurs between the light shielding layer 12a and the color filter layer 15 applied to the color pixel portion 14. . For this reason, the overcoat layer 16 formed on the color filter layer 15 and the light-shielding layer 12a as a protective film must be coated with a thickness of at least the step, and the thickness of the overcoat layer 16 increases.

As a result, when a conventional color filter substrate is used to form a flat panel display for a color liquid crystal surface, for example, the distance between the liquid crystal substrate and the glass substrate on the color filter side is increased, and this distance is increased. Due to the above, there is a disadvantage that the viewing angle of the color filter substrate becomes small.

The color filter is applied to the surface of the glass substrate relatively thickly (about 2 μm), and the peripheral wall of the applied color filter layer hangs down to shield the light-shielding layer 12.
It is easy to diffuse on a. For this reason, the angle of the corner formed by the peripheral wall of the color filter layer and the light shielding layer 12a cannot be kept at a right angle, so that color bleeding or color unevenness of the color filter occurs and the contrast ratio decreases. There is also a problem of inviting them.

Further, in the conventional method of manufacturing a color filter substrate, when the color filter is applied on the glass substrate, each color of the red (R), green (G) and blue (B) color filters is formed by photolithography. Red (R), green (G), and blue (B) are applied because they are applied sequentially.
In order to form each layer of
In addition to requiring steps, it is complicated in other steps,
For these reasons, it has been difficult to mass-produce color filter substrates by the conventional manufacturing method.

The present invention has been made in order to solve these problems, and can widen the viewing angle as compared with the prior art, and is a high quality color filter free from color bleeding and color unevenness of the color filter. It is an object of the present invention to provide a substrate and a manufacturing method of this color filter substrate, which has simplified steps and enables mass production.

[0011]

In order to achieve the object of the present invention, a color filter substrate of the present invention is such that a light-shielding layer having a predetermined pattern is formed on a transparent substrate,
In a color filter substrate in which a color filter layer is formed on the transparent substrate excluding the light shielding layer, the transparent substrate surface portion on which the color filter layer is formed,
It is characterized in that a recess having a predetermined depth is formed.

Further, in this method for manufacturing a color filter substrate, after forming a thin film layer on the surface of the transparent substrate, the thin film layer and the transparent substrate reach a predetermined depth from the surface of the transparent substrate in a predetermined pattern. By performing etching, the remaining thin film layer is used as a light-shielding layer, and a recess is formed on the substrate surface excluding the transparent substrate directly below the light-shielding layer, and then the color filter layer is formed in the recess. It is attached.

In the manufacturing method of the present invention, it is preferable that the color filter layer is formed by applying a color filter by an offset printing method.

[0014]

According to the color filter substrate of the present invention, the color filter layer is formed in the concave portion formed in the transparent substrate surface portion, and the color filter layer is formed from the transparent substrate surface by the depth of the concave portion. The amount of protrusion is suppressed, and the step between the color filter layer and the transparent substrate surface can be almost eliminated. As a result, the thickness of the overcoat layer that covers the entire surface of the transparent substrate including the color filter layer is reduced as compared with the conventional one.

Therefore, when a flat panel display for a color liquid crystal surface is constructed using this color filter substrate, the distance between the liquid crystal substrate and the transparent substrate including this color filter can be made narrower than in the conventional case. , The viewing angle of the color filter substrate does not become small, and color bleeding and color unevenness of the color filter occur.
Alternatively, it is possible to prevent a decrease in contrast.

In the method for manufacturing a color filter substrate of the present invention, a recess is formed on the surface of the substrate except the light-shielding layer and the transparent substrate immediately below the light-shielding layer by etching, and the color filter layer is formed in the recess. The step between the light shielding layer and the color filter layer can be almost eliminated. Also, the whole process is simplified.

Further, if the step of applying the color filter layer by the offset printing method is used, the step of forming each layer of red (R), green (G) and blue (B) can be simplified in one step. It also enables mass production of this type of color filter substrate.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment of this color filter substrate.

In this color filter substrate 10, a light-shielding layer 2 made of a thin film of Cr or Ta and having a predetermined thickness formed by sputtering or the like is formed on the surface of a transparent glass substrate 1. On the surface of the glass substrate 1 to be removed, a color pixel portion 3 which is dry-etched concavely is formed to a depth of about 1.5 μm. Each color pixel portion 3 is coated with each color filter layer 4 of red (R), green (G), and blue (B). Further, an overcoat layer 5 is formed on the light shielding layer 2 and the color filter layer 4 as a protective film covering the entire surfaces thereof, and an ITO layer 6 is formed on the overcoat layer 5. There is.

The color filter substrate 10 of the present invention having the above structure is manufactured by the manufacturing method described below. FIG. 2 is a schematic sectional view showing this method over time. A description will be given below with reference to this drawing.

First, a thin film layer 2a to be the light shielding layer 2 is formed on the surface of the transparent glass substrate 1 by a vacuum evaporation method or sputtering to a predetermined thickness, and then a photosensitive resist is formed on the thin film layer 2a. 7 is applied [FIG. 2 (a)].

Next, the photosensitive resist 7 is applied to the color pixel portion 3
Except for the portion where is formed, exposure and development are performed to dry-etch the undeveloped portion of the photosensitive resist 7. At this time, the surface of the glass substrate 1 is dry-etched into a recess having a depth of about 1.5 μm to form the color pixel portion 3. Then, the photosensitive resist 7 remaining on the thin film layer 2a
Is peeled off to expose the light shielding layer 2 [FIG. 2 (b)].

Next, in a state where the glass substrate 1 is exposed to a vacuum atmosphere, an offset printing method is used and the color pixel portion 3 is provided with red (R), green (G),
By applying blue (B) in one step, the color pixel portion 3
Then, the color filter layer 4 is formed. Due to the presence of the light-shielding layer 2, mixing of the colors of red (R), green (G), and blue (B) of the color filter is prevented. Further, since the color filter is applied to the concave color pixel portion 3, it is possible to almost eliminate the step between the formed color filter layer 4 and the light shielding layer 2 [FIG. 2 (c)].

After that, an overcoat layer 5 as a protective film is applied on the color filter layer 4 and the light shielding layer 2, and then I is further formed on the overcoat layer 5.
The TO film 6 is formed. As a result, the color filter substrate 10 according to the embodiment of the present invention is completed [FIG. 2 (d)].

In the color filter substrate 10 manufactured by the above method, the surface of the glass substrate 1 corresponding to the color pixel portion 3 to which the color filter is applied has a depth of about 1.5 μm.
Since a red (R), green (G), and blue (B) color filter is applied to the color pixel portion 3 by dry etching so as to form a recessed portion of a certain degree, like a conventional color filter substrate. As compared with the case where the color filter is applied to the surface of the flat glass substrate, the amount of protrusion of the color filter layer 4 from the surface of the glass substrate 1 can be suppressed low. Therefore,
Compared with the conventional color filter substrate, there is almost no step between the surface of the glass substrate 1 and the color filter layer 4, and thus the thickness of the overcoat layer 5 and the ITO film 6 can be reduced. As a result, when a flat panel display for color liquid crystal display using this color filter substrate is constructed, the distance between this liquid crystal substrate and the transparent substrate on the color filter side can be made narrower than in the conventional case. It is possible to solve the problem that the viewing angle of the filter substrate becomes small. In addition, it is possible to prevent color bleeding or color unevenness of the color filter or a decrease in contrast ratio.

As described above, the color filter substrate as described above can be formed by the manufacturing method according to the present embodiment. Further, in this method, since the color filter is applied by the offset printing method, the applying step is completed in one step, which can be a simplified step, and moreover, the color filter substrate can be mass-produced.

Although the glass substrate 1 is directly etched to a depth of 1.5 μm in this embodiment, the depth of etching the glass substrate 1 is not limited to this, and the thickness of the color filter layer is not limited to this. It is also possible to adjust the etching depth according to the characteristics of the color filter.

Further, as a method of applying the color filter to the etched portion of the glass substrate 1, it is possible to cope with mass production by using the offset printing method.
The method of applying the color filter is not limited to this, and for example, screen printing or the like can be used.

Further, in the present invention, the color filter substrate 10
Was used for liquid crystal, but this color filter substrate 1
The use of 0 is not limited to this, and it can be used for plasma display or EL panel. In short, if it is used as a flat panel for color display, its use does not matter.

[0030]

As described above, according to the color filter substrate of the present invention, since the concave portion for forming the color filter layer is formed on the transparent substrate surface excluding the light shielding layer, It is possible to almost eliminate the step from the light-shielding layer, and it is possible to reduce the thickness of the overcoat layer that covers the entire surface of the transparent substrate including the color filter layer as compared with the conventional case.

As a result, the viewing angle of the color filter substrate is widened, and the problems such as color bleeding and color unevenness of the color filter or the deterioration of contrast are eliminated, and the quality is further improved.

According to the manufacturing method of the present invention, when a color filter substrate is manufactured, a recess is formed by etching the transparent substrate to a predetermined depth from the surface, and the color is formed in the recess. Since the filter is applied, the application thickness of the color filter can be easily controlled, and the whole process can be simplified. As a result, productivity can be dramatically improved.

Further, when the color filter layer is formed by the offset method, the manufacturing process is simple and there is an advantage that the color filter substrate can be mass-produced.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a color filter substrate of the present invention.

FIG. 2 is a schematic cross-sectional view showing an embodiment of a method for manufacturing a color filter substrate of the present invention over time.

FIG. 3 is a schematic sectional view showing a conventional color filter substrate and a method for manufacturing the same over time.

[Explanation of symbols]

 1 ... Glass substrate 2 ... Light-shielding layer 3 ... Color pixel portion 4 ... Color filter layer 5 ... Overcoat layer 6 ... ITO film 10 ... Color filter substrate

Claims (3)

[Claims] 1. A color filter substrate comprising a transparent substrate on which a light-shielding layer having a predetermined pattern is formed, and a color filter layer formed on the transparent substrate excluding the light-shielding layer. A color filter substrate, wherein a concave portion having a predetermined depth is formed on a surface portion of the formed transparent substrate. 2. The method for manufacturing a color filter substrate according to claim 1, wherein after forming a thin film layer on the surface of the transparent substrate, the thin film layer and the transparent substrate are patterned in a predetermined pattern. The remaining thin film layer is used as a light-shielding layer by performing etching to reach a predetermined depth from the surface of the substrate, and a recess is formed on the substrate surface excluding the transparent substrate directly below the light-shielding layer. A method for manufacturing a color filter substrate, which comprises forming a filter layer. 3. The method of manufacturing a color filter substrate according to claim 1, wherein the color filter layer is formed by applying a color filter by an offset printing method. Method for manufacturing color filter substrate.