JP4968429B2 - Manufacturing method of color filter forming substrate for liquid crystal display device - Google Patents

Description

The present invention is related to method of manufacturing a color filter formation substrate used in a transflective liquid crystal display device having both the display function and the transmissive display function and the reflective display function.

In recent years, liquid crystal display devices have been widely used as display devices for televisions or personal computers, and recently, they have been used for large and high-definition monitors in addition to small and medium-sized portable information terminals and notebook computers. .
Under such circumstances, in particular, in liquid crystal display devices used for devices used both outdoors and indoors such as portable information terminals, they are actively used as illumination means for display devices in environments where external light is sufficiently strong. Liquid crystal display devices that use outside light and use a backlight as illumination means in an environment where the outside light is weak have become mainstream.
Such a liquid crystal display device having display functions of both reflective display and transmissive display is referred to as a transflective liquid crystal display device or a reflective / transmissive liquid crystal display device.

Initially, in a transflective liquid crystal display device provided with a color filter, the displayed light is transmitted through a color filter in a transmissive region displayed by light from a backlight and a reflective region displayed using external light. Since the number of times of passage is different and the optical path lengths are different, it is difficult to realize a display in which both the transmission region and the reflection region are bright and the color purity is high (color reproducibility is high).
In order to solve this problem, Japanese Patent Application Laid-Open No. 2000-111902 (Patent Document 1) discloses a liquid crystal display device having a region where a color filter layer is not formed in a part of a reflective region. Yes.
However, the one described here has a drawback in that a display with sufficiently high color purity cannot be obtained, although the decrease in transmittance in the reflection region is reduced and the light utilization efficiency is increased. It was.

Correspondingly, the device described in Japanese Patent Application Laid-Open No. 2004-85986 (Patent Document 2) proposes a liquid crystal display device that is bright in both the transmissive region and the reflective region and can display with high color purity. Yes.
JP, 2004-85986, A Here, as shown in Drawing 7, transparent insulating resin 112 is arranged in a reflective field, and colored layer formation substrate 110 which formed colored layer 113 on it, and reflected in a reflective field A liquid crystal display device having a structure in which a liquid crystal layer is provided between both substrates using an active matrix substrate 120 provided with electrodes 123 is cited. The colored layer forming substrate 110 described here is, after forming a transparent insulating resin (also referred to as a colored film thickness adjusting layer) 112 as shown in FIG. It is assumed that the colored layer 113 is formed by a photolithography method, and the thicknesses of the colored layer 113 in the transmissive region Ta and the colored layer in the reflective region Ra cannot be controlled to a desired thickness, which is a problem. It was. In this method, a colored layer having a thickness larger than the target is formed in the reflective region Ra. A flow of processing steps of this method is shown in FIG.

On the other hand, in order to obtain a desired film thickness and a desired color purity in each of the transmissive region and the reflective region, a schematic diagram of a partial cross section thereof, as shown in FIG. A method of forming a colored layer separately in each of the reflective regions Ra is also employed.
In this method, in order to improve the display color quality of the reflective area and the transmissive area, the respective colors are set, and the color film thickness is controlled in order to control the liquid crystal film thickness. . For example, for each colored layer, in the reflective region Ra formed with a large film thickness, a colored material with a low pigment concentration is used to perform mask exposure with a predetermined exposure amount, and the transmissive region Ta formed with a thin film thickness is Using a coloring material having a high pigment concentration, mask exposure is performed with a predetermined exposure amount to form colored layers, respectively.
For this reason, the flow of the processing steps of this method is as shown in FIG. 6, and the processing steps are longer than the method disclosed in Japanese Patent Application Laid-Open No. 2004-85986 shown in FIG. However, there has been a problem of reduced productivity and complicated work due to the variety of colored layer materials.

As described above, in recent years, in devices used both outdoors and indoors such as portable information terminals, transflective liquid crystal display devices having both display functions of reflection display and transmission display are popular. This is a method for manufacturing a color filter forming substrate that can improve the color quality of a display when used in such a transflective liquid crystal display device. There has been a demand for a method for manufacturing a color filter-formed substrate having good properties.
The present invention corresponds to this, and is a method for manufacturing a color filter forming substrate that can improve the color quality of display when it is used in a transflective liquid crystal display device. An object of the present invention is to provide a method for manufacturing a color filter forming substrate .

The method for manufacturing a color filter forming substrate for a liquid crystal display device according to the present invention is used in a transflective liquid crystal display device having both a reflective display function and a transmissive display function , and the reflective display of the liquid crystal display device. A method for manufacturing a color filter forming substrate in which a transparent dielectric layer and a colored layer are arranged in order from the substrate side in a region corresponding to a reflective region that is a region having a function, on one surface of the color filter forming substrate, A transparent insulating resin layer (also referred to as a pillow or a white layer) having a predetermined thickness is provided in a region corresponding to the reflective region of the liquid crystal display device in order to adjust the position in the thickness direction of the colored layer in this region. Then, for each color of the colored layer to be formed, on the side of the color filter forming substrate on which the transparent insulating resin layer having the predetermined thickness is disposed, respectively, in order, unexposed negative photosensitive resin Predetermined arrival The layers material, covering the transparent insulating resin layer, a colored layer coating step of flat coated and formed, an exposure step of batch exposure only colored layer forming region through an exposure mask by a proximity exposure method, The first region corresponding to the transmissive display region of the liquid crystal display device of the exposure mask is a first region that performs a development process, a drying process, and a baking process to form a colored layer. An opening pattern having all the areas as openings is provided, and the second area corresponding to the reflective display area of the liquid crystal display device of the exposure mask is exposed to the color layer material by exposure over the entire area. A fine aperture pattern having a predetermined aperture ratio having a plurality of fine apertures that do not resolve the first aperture area is provided. In the batch exposure, by using the exposure mask, And controlling the exposure amount to the colored layer material in each area exposed corresponding to the second area, and controlling the thickness of the colored layer in each area to a desired thickness. It is characterized by.
In the method for manufacturing a color filter forming substrate for a liquid crystal display device, the plurality of fine openings of the fine pattern may be one or more of a line shape, a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, and a hexagonal shape. It is characterized by comprising.
In addition, in any one of the above-described methods for manufacturing a color filter forming substrate for a liquid crystal display device, the aperture ratio of the fine aperture pattern is 5% or more and 60% or less.
Here, the aperture ratio means the ratio of the total area of the fine openings to the area of the fine opening pattern area provided in the second area of the exposure mask.

An exposure mask according to the present invention is an exposure mask used for proximity exposure in a method for manufacturing a color filter forming substrate used in a transflective liquid crystal display device having both a reflective display function and a transmissive display function. In the first area corresponding to the transmissive display area of the liquid crystal display device of the exposure mask, an opening pattern having all the first areas as openings is provided, and the exposure mask In the second region corresponding to the reflective display region of the liquid crystal display device, a fine aperture pattern having a predetermined aperture ratio having a plurality of fine apertures that do not resolve the colored layer material by exposure over the entire region. it is characterized in that the over emissions are al provided.

(Function)
The method for manufacturing a color filter forming substrate for a liquid crystal display device according to the present invention has such a structure, and can improve the color quality of a display when used in a transflective liquid crystal display device. With the method for manufacturing a formation substrate, it is possible to provide a method for manufacturing a color filter formation substrate with few production steps and good productivity.
Specifically, a transparent insulating material having a predetermined thickness for adjusting the position in the thickness direction of the colored layer in the region corresponding to the reflective region of the liquid crystal display device on one surface of the color filter forming substrate. After disposing a conductive resin layer (also referred to as a pillow or a white layer), on the side of the color filter forming substrate on which the transparent insulating resin layer having the predetermined thickness is disposed for each color of the colored layer to be formed , Respectively, a non-exposed negative photosensitive predetermined coloring layer material covering the transparent insulating resin layer and forming a flat coating layer, and proxying only the colored layer forming region. A liquid crystal display for forming a colored layer by performing an exposure step of batch exposure through an exposure mask by a Mitty exposure method and a process step of development processing, drying, and baking processing, and the liquid crystal display of the exposure mask Equipment transparency The first area corresponding to the display area is provided with an opening pattern having the entire first area as an opening, and the second area corresponding to the reflective display area of the liquid crystal display device of the exposure mask is provided. Is provided with a fine aperture pattern having a predetermined aperture ratio having a plurality of fine apertures that do not resolve each colored layer material by exposure over the entire area, and the exposure mask is used in the batch exposure. By controlling the exposure amount to the colored layer material in each area exposed corresponding to the first area and the second area, the thickness of the colored layer in each area is set to a desired thickness. is intended to control the more to the embodiment of the invention of claim 1 has achieved this.
Here, the coloring in each area | region is devised by controlling the exposure amount to the coloring layer material in each area | region exposed corresponding to the said 1st area | region and the said 2nd area | region, devising the exposure mask. It is possible to control the thickness of the layer to a desired thickness.
That is, in the liquid crystal display device 100 shown in FIG. 7, the thickness of the colored layer 113 in the transmissive region Ta and the thickness of the colored layer 113 in the reflective region Ra can be controlled. As a result, the colored layer forming substrate 110 and the reflective electrode 123 are controlled. It is assumed that the thicknesses Tt and Tr of the liquid crystal layer 150 in the transmissive region Ta and the reflective region Ra can be controlled with respect to the active matrix substrate 120 on which is disposed.
In the form of the invention of claim 1, the form of claim 2 in which the plurality of fine openings of the fine pattern is composed of one or more of a line shape, a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, and a hexagonal shape.
Further, by adopting the form of the invention of claim 3 in which the aperture ratio of the fine aperture pattern is 5% or more and 60% or less, the level of practical use corresponds to the sensitivity of the colored layer material of each color. Thus, the desired film thickness can be realized.
When the aperture ratio is 5% or less, the exposure amount becomes too low to obtain sufficient curing and a pattern is not formed.
If it is 60% or more, the difference in exposure amount with the first region is small, and a sufficient effect cannot be obtained. And it is especially preferable when the aperture ratio of the said fine opening pattern is 10% or more and 30% or less.

The present invention, as described above, is a method for manufacturing a color filter-formed substrate that can improve the color quality of display when it is used in a transflective liquid crystal display device. It has become possible to provide a method for manufacturing a color filter forming substrate .

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a cross-sectional view showing an exposure process of a characteristic part of an example of an embodiment of a method for producing a color filter forming substrate for a liquid crystal display device of the present invention, and FIG. a cross-sectional view illustrating a colored layer formed of a portion corresponding to a), and FIG. 2 (a), FIG.. 2 (b), respectively, showing a portion of an example of dew light mask according to the present invention in plan view, FIG. 3 (a), 3 (b) is a diagram for explaining the formation of the colored layer in the pixel portion of the color filter forming substrate for liquid crystal display device according to the present onset bright.
1 to 3, 10 is a color filter forming substrate, 10A is a color filter forming substrate, 11 is a transparent substrate, 12 is a transparent insulating resin layer (also referred to as a pillow or white layer), and 13 is (unexposed). ) Colored layer material, 13a is a colored layer (in a region exposed corresponding to the first region), 13b is a colored layer (in a region exposed corresponding to the second region), and 20 and 20a are An exposure mask, 21 is a transparent substrate, 25 is an opening (in the first region), 26 is an opening (in the second region), 27 is a light-shielding film, 28 is a halftone film, 30 is exposure light, and 40a is a pixel Area, 40 is a colored pixel portion, 41 is a colored layer (in the area corresponding to the transmissive area), 41a is a colored layer (in the area corresponding to the reflective area), 42 is a colored layer (in the area corresponding to the transmissive area), 42a is a colored layer (in the region corresponding to the reflective region), and 43 is (transmitted) Region of) the colored layers corresponding to the band, 43a is a region corresponding to the (reflective area) colored layer, Gp is the gap.

First, an example of an embodiment of a method for producing a color filter forming substrate for a liquid crystal display device according to the present invention will be described with reference to FIG.
The method for producing a color filter forming substrate for a liquid crystal display device of this example is a method for producing a color filter forming substrate used for a transflective liquid crystal display device having both a reflective display function and a transmissive display function. .
In this example, simply, first, a black matrix (also referred to as BM) made of a resin layer (not shown) is formed on one surface of a transparent substrate 11 made of glass or the like as a base substrate of a color filter forming substrate. Further, a transparent layer having a predetermined thickness for adjusting the position in the thickness direction of the colored layer in the region corresponding to the reflective region of the liquid crystal display device is formed on the surface on the black matrix (also referred to as BM) forming side. An insulating resin layer (also referred to as pillow or white layer, 12 in FIG. 1A) is provided.
The transparent insulating resin layer 12 having a predetermined thickness is formed by, for example, pattern-exposing a negative transparent acrylic photosensitive material (for example, acrylic resin manufactured by Nippon Synthetic Rubber) with active light, and then using an alkali developer. The film is formed by development, washing with water, and then heat treatment. However, the formation method is not limited to this, and patterning, printing, or transfer by etching may be used.
In general, the thickness of the insulating resin layer 12 is preferably in the range of 1 μm to 6 μm, and more preferably in the range of 2 μm to 5 μm.
Then, for each color of the colored layer to be formed, on the side of the color filter forming substrate 10A on which the transparent insulating resin layer 12 having the predetermined thickness is disposed, in order, the unexposed negative photosensitive resin, respectively. A colored layer coating process for coating and forming a predetermined colored layer material, an exposure process for exposing only the colored layer forming area through an exposure mask by a proximity exposure method, and a process process of development, drying, and baking And the process is performed to form the entire colored layer.
For example, an acrylic pigment-dispersed photosensitive material is used as the coloring layer material.

Here, an exposure process that is characteristic in the method of manufacturing a color filter forming substrate for a liquid crystal display device of this example will be described.
As shown in FIG. 1A, the transparent insulating resin layer 12 having the predetermined thickness is covered, and only the colored layer forming region is exposed to the flat colored layer material 13 by using an exposure mask 20. Exposure is performed by an exposure method.
As shown in FIG. 2A, the exposure mask 20 is provided with an opening pattern 25 having openings in the first region corresponding to the transmissive display region, and the insulating resin layer 12 is provided. The second area corresponding to the reflective display area is provided with a fine aperture pattern having a predetermined aperture ratio having a plurality of fine apertures that do not resolve each colored layer material by exposure. The portion corresponding to the transmission region of the colored layer 13 is exposed from the second region, and the portion corresponding to the reflection region of the colored layer 13 is exposed from the second region.
When the exposure amount in the exposure from the first region to the colored layer 13 is 100, the exposure amount in the exposure from the second region to the colored layer 13 is usually controlled to a range of 5 to 30. Accordingly, the aperture ratio of the fine pattern in the second region is set to 5% to 30%.
A conventional transparent insulating resin layer (also referred to as pillow or white layer, 112 in FIG. 4 (a)) is provided, and a colored layer is applied thereon, so that both the reflective area equivalent part and the transmissive area equivalent part are provided. Even in the method of developing with exposure with the same exposure amount, the thickness of the colored layer corresponding to the reflective region can be formed thinner than the thickness of the colored layer corresponding to the transmissive region. In the case of this example, the thickness of the colored layer 13b corresponding to the reflective region can be effectively made thinner than the thickness of the colored layer 13a corresponding to the transmissive region.
In the proximity exposure method, exposure is performed with a gap Gp of about 100 μm to 200 μm. In this case, since the width of about 8 μm is said to be the resolution limit, the width is 4 μm as shown in FIG. The following line-shaped openings 26 are arranged in the second region at a predetermined pitch in accordance with the opening ratio.
In this example, by appropriately selecting the exposure time for batch exposure and the aperture ratio, a desired thickness can be obtained in each of the transmission region equivalent portion and the reflection region equivalent portion.
The plurality of fine openings 26 in the fine pattern are in a line shape here, but are not limited thereto.
A line shape, a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, or a hexagonal shape can be applied.
The exposure mask 20 is formed by a photolithography method using a drawing exposure apparatus using a known laser or an EB drawing exposure apparatus using an electron beam.
As the light shielding film 27, a chromium-based film is usually used, but is not limited thereto.

For each pixel region 40a, first, as shown in FIG. 3A, the colored layers 41 and 41a are formed, and then the colored layers 42 and 42a shown in FIG. 3B are formed. The colored layers 43 and 43a shown in 3 (b) are formed, and the colored pixel portion 40 is formed as a whole. (See Fig. 3 (b))
Here, the colored layers 41, 42, and 43 are thick in the colored layer in the region corresponding to the transmission region, respectively, and the colored layers 41a, 42a, and 43a are in the colored layer in the region corresponding to the reflective region, respectively. Compared to 41, 42, and 43, it is formed thinner.
In this manner, the color filter forming substrate 10 in which all the colored layers are formed in each pixel region 40a is obtained.

Instead of the fine pattern in the second region of the mask for exposure in this example, the entire second region has a transmittance characteristic corresponding to the transmission characteristic of the exposure light of the previous fine pattern with respect to the exposure light. A mode in which exposure is performed in the same manner by forming a halftone film is also included.
Examples of the halftone film include a film made of chromium oxide, chromium oxynitride, chromium, tantalum, and the like.

FIG. 1A is a cross-sectional view showing an exposure process of a characteristic part of an example of an embodiment of a method for producing a color filter forming substrate for a liquid crystal display device of the present invention, and FIG. It is sectional drawing which showed the colored layer in which the location corresponding to a) was formed. FIG. 2 (a), FIG. 2 (b) are plan views showing a portion of an example of dew light mask according to the present invention. 3A and 3B are views for explaining the formation of a colored layer in the pixel portion of the color filter forming substrate for a liquid crystal display device according to the present invention. It is sectional drawing which showed the one part cross section by the conventional colored layer formation. It is the flowchart which showed the processing flow of the conventional colored layer formation. It is the flowchart which showed the processing flow of another conventional colored layer formation. It is sectional drawing of a part of transflective liquid crystal display device.

Explanation of symbols

10 color filter forming substrate 10A color filter forming substrate 11 transparent substrate 12 transparent insulating resin layer (also called pillow or white layer)
13 Colored layer material 13a (in an area exposed corresponding to the first area) Colored layer 13b (in an area exposed corresponding to the second area) Colored layers 20, 20a (unexposed) Mask 21 Transparent substrate 25 Opening 26 (first area) Opening 27 (second area) 27 Light shielding film 28 Halftone film 30 Exposure light 40 a Pixel area 40 Colored pixel portion 41 (area corresponding to transmission area) Colored layer 41a Colored layer 42 (in the region corresponding to the reflective region) Colored layer 42 (in the region corresponding to the transmissive region) Colored layer 42a (in the region corresponding to the reflective region) Colored layer 43 (in the region corresponding to the transmissive region) 43a Colored layer Gp (region corresponding to reflective region) Gap 100 Liquid crystal display device 110 Colored layer forming substrate 111 Transparent insulating substrate 112 Transparent insulating resin layer (also referred to as transparent dielectric layer, pillow, white layer)
113 Colored layer 120 Active matrix substrate 121 Transparent insulating substrate 122 Transparent electrode 123 Reflective electrode (also simply referred to as reflective layer)
130, 135 Polarizing plate 140 Backlight 150 Liquid crystal layer 160 Reflected display light 165 Transmitted display light Ta Transmitted area Ra Reflected area Tt Thickness (of the liquid crystal layer in the transmissive area) Thickness (of the liquid crystal layer in the reflective area)

Claims (3)

A region that corresponds to a reflective region that is used in a transflective liquid crystal display device having both a reflective display function and a transmissive display function , and that has a reflective display function of the liquid crystal display device, from the substrate side. A method of manufacturing a color filter forming substrate in which a transparent dielectric layer and a colored layer are arranged in order, and coloring in this region is performed on one surface of the color filter forming substrate on a region corresponding to the reflective region of the liquid crystal display device. for adjusting the position in the thickness direction of the layer, after arranging the transparent insulating resins layer having a predetermined thickness, for each color of the colored layer to be formed, the color filter forming substrate, the predetermined thickness Each of the transparent insulating resin layers on which the transparent insulating resin layer is disposed is coated with an unexposed negative photosensitive predetermined coloring layer material in order , covering the transparent insulating resin layer in a flat manner. Colored layer application process and colored layer formation process Only a single exposure process using a proximity exposure method through an exposure mask, and a process step of development, drying, and baking to form a colored layer, and the exposure mask The first area corresponding to the transmissive display area of the liquid crystal display device is provided with an opening pattern having the entire first area as an opening, and corresponds to the reflective display area of the liquid crystal display device of the exposure mask. The second region is provided with a fine aperture pattern having a predetermined aperture ratio having a plurality of fine apertures that do not resolve the colored layer material by exposure over the entire region. By using the exposure mask, the exposure amount to the coloring layer material in each region exposed corresponding to the first region and the second region is controlled, The film thickness of the colored layer in the range, the production method of the color filter formation substrate for a liquid crystal display device, characterized in that is configured to control to a desired thickness.   The method for manufacturing a color filter forming substrate for a liquid crystal display device according to claim 1, wherein the plurality of fine openings of the fine pattern have a line shape, a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, and a hexagonal shape. A method for producing a color filter forming substrate for a liquid crystal display device comprising one or more.   3. The method of manufacturing a color filter forming substrate for a liquid crystal display device according to claim 1, wherein an aperture ratio of the fine aperture pattern is 5% or more and 60% or less. A method for manufacturing a color filter forming substrate for a liquid crystal display device.

Images