JP2020183995A - Color filter and manufacturing method thereof - Google Patents

Abstract

To obtain a color filter in which a top face of a white pixel part is flat, without forming a pattern composed of the same material as a color pixel or a black matrix on the white pixel part.SOLUTION: A color filter has a light-shielding pattern according to a black matrix on a transparent substrate, and a display area constituted of multiple coloring pixels and white pixels. The color filter is manufactured by commonly covering the area of the multiple coloring pixels and white pixels by using a transparent overcoat resin layer, providing a structure forming photospacers on the overcoat resin layer, and further, forming photospacers inside the white pixels to fill recesses of the overcoat resin layer in the area of the white pixels.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid crystal display device, an organic EL element, a color filter used for an organic EL display, and a method for manufacturing the same.

Conventionally, as in Patent Document 1, in a flat panel display such as a liquid crystal display device or an organic EL display device, a resin-dispersed black matrix divided into a plurality of rectangular pixels formed on a transparent glass substrate for color display. (Resin BM) and a color filter including colored pixels of a plurality of colors formed on the rectangular pixels have been used. That is, as a plurality of colored pixels, a four-color (RGBW) configuration in which white pixels (W pixels) are added in addition to the conventional three colors of red (R pixel), green (G pixel), and blue (B pixel). A color filter is used.

A color resist is not used for the W pixel portion, and this portion is filled with an overcoat resin layer for flattening the entire surface of the color filter substrate.

That is, after forming the red pixels, the green pixels, and the blue pixels, the overcoat resin layer is collectively formed on the entire surface, and at that time, the space to be occupied by the white pixels is filled with the overcoat resin layer.

However, in this manufacturing method, since the white pixels and the overcoat resin layer can be formed collectively, the influence on the cost and the non-defective rate is small, but the white pixel portion has a dent on the surface even if it is filled with the overcoat resin layer. Since it is not flat and the thickness of the liquid crystal layer formed thereafter changes, there is a problem that the display characteristics are deteriorated.

Therefore, in Patent Document 1 and Patent Document 2, a pattern is formed in the white pixel with a colored resist or a black matrix to reduce the dent.

JP-A-2017-040678 Japanese Unexamined Patent Publication No. 2014-098780

However, with the progress of miniaturization of the color pixel size of the color filter, it is necessary to miniaturize the pattern of the colored resist and the black matrix formed in the pixel, and the white pixel as in Patent Document 1 and Patent Document 2. Since the pattern formed inside is smaller than the color pixels and the like, the size varies. Due to this variation, the brightness of the white pixels varies, so that there is a problem that the white pixels appear to be uneven when used as a display device.

Therefore, an object of the present invention is to obtain a color filter having an RGBW configuration in which the upper surface of the white pixel portion is flattened without forming a pattern made of the same material as the color pixel or the black matrix in the white pixel portion. Make it an issue.

The present invention is a color filter having a light-shielding pattern by a black matrix on a transparent substrate and a display area composed of a plurality of colored pixels and white pixels in order to solve the above problems.
It has a structure in which regions of the plurality of colored pixels and white pixels are commonly covered with a transparent overcoat resin layer, and a photo spacer is formed on the overcoat resin layer.
The color filter is characterized in that a photospacer in a white pixel is formed in a recess of the overcoat resin layer on the region of the white pixel to fill the recess.

In the present invention, according to this configuration, the photospacer in the white pixel fills the recess of the overcoat resin layer in the region of the white pixel, and the height above the region of the white pixel is the same as the height of the region of the other color pixels. It has the effect of obtaining a color filter that matches the color.

Further, the present invention is the above-mentioned color filter, wherein the photospacer in the white pixel has the same height as the photospacer formed on the overcoat resin layer on the light-shielding pattern and the colored pixel. It is a characteristic color filter.

Further, the present invention is a method for manufacturing a color filter having a light-shielding pattern by a black matrix on a transparent substrate and a display area composed of a plurality of colored pixels and white pixels.
A step of commonly covering the regions of the plurality of colored pixels and white pixels with a transparent overcoat resin layer, and
It has a step of forming a photo spacer on the overcoat resin layer.
A method for manufacturing a color filter, which comprises forming a photospacer in a white pixel in a recess of the overcoat resin layer on the region of the white pixel to fill the recess.

Further, the present invention is the above-mentioned method for manufacturing a color filter, wherein the photospacer in the white pixel is set to the same height as the photospacer formed on the overcoat resin layer on the light-shielding pattern and the colored pixel. It is a method for manufacturing a color filter, which is characterized by forming.

The present invention solves the problem that the overcoat resin layer of the color filter is dented in the white pixel region, and forms a photospacer in the white pixel on the overcoat resin layer in the white pixel region.

In the present invention, the photospacer in the white pixel fills the dent of the overcoat resin layer in the region of the white pixel, so that the white pixel portion is white without forming a pattern made of the same material as the color pixel or the black matrix. There is an effect of obtaining a color filter in which the height above the pixel area is aligned with the height of the area of other color pixels.

It is sectional drawing of the color filter of embodiment of this invention. It is schematic cross-sectional view (the 1) which shows the manufacturing method of the color filter of embodiment of this invention. It is schematic cross-sectional view (the 2) which shows the manufacturing method of the color filter of embodiment of this invention.

An embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic cross-sectional view of a color filter. A transparent conductive layer (not shown) is provided on the color filter.

In the color filter of the embodiment of the present invention, as shown in the cross-sectional view of FIG. 1, a light-shielding layer 2 (black matrix BM) and colored pixels 3 are formed on a transparent substrate 1, and an overcoat resin layer OC is formed on the light-shielding layer 2 (black matrix BM). A transparent conductive layer (not shown) made of ITO or the like is provided on the overcoated resin layer OC and a photospacer PS is provided on the overcoated resin layer OC and the transparent conductive layer.

(Transparent board)
The material of the transparent substrate 1 is inorganic glass such as quartz glass, borosilicate glass, and soda glass, plastic substrates such as PET, PES, and PC, or silicon oxide, aluminum oxide, and silicon nitride on these glass substrates and plastic substrates. A film formed of an inorganic thin film such as silicon oxynitride can be used properly according to the purpose and application of use.

(Shading layer)
The light-shielding layer 2 (black matrix BM) is formed to have a film thickness of 1 μm to 2 μm. The light-shielding layer 2 is formed in a pattern that divides the display area in a grid pattern.

(Colored pixels)
The colored pixels 3 forming the colored pixels 3 of a plurality of colors partitioned by the grid pattern of the light-shielding layer 2 in the display area on the transparent substrate 1 are the red colored pixels 3R, the green colored pixels 3G, and the blue colored pixels 3B. The three-color colored pixels 3 of the above are formed. The red-colored pixel 3R, the green-colored pixel 3G, and the blue-colored pixel 3B are formed to have, for example, a film thickness of 2 μm to 3 μm.

The light-shielding layer 2 and the colored pixels 3 are formed by using a photosensitive colored resin composition, and the photosensitive colored resin composition appropriately contains a pigment as a coloring agent, a light initiator, a polymerizable monomer, or the like in a transparent resin. It is manufactured by dispersing it in a suitable solvent.

(White pixel)
In addition, white pixels (W) that do not fill the colored pixels 3 are formed in the pixel regions of the light-shielding layer 2 partitioned by the grid pattern. That is, the white pixel (W) is formed as an empty region to be filled with the overcoat resin layer OC when the overcoat resin layer OC covering the region of the colored pixel 3 is collectively formed.

(Overcoat resin layer)
The light-shielding layer 2 and the colored pixels 3 thus formed are covered with a transparent overcoat resin layer OC. As a result, the overcoated resin layer OC covers the region of the colored pixel 3 and fills the region of the white pixel (W).

Here, when the region of the white pixel (W) is filled with the overcoat resin layer OC, a dent on the surface of the overcoat resin layer OC is formed in the region of the white pixel (W).

(Transparent conductive layer)
A transparent conductive layer (not shown) made of ITO or the like is provided on the overcoat resin layer OC.

(Photo spacer)
Next, the photo spacer PS is provided on the overcoat resin layer OC and the transparent conductive layer. The photo spacer PS forms the photo spacer PS on the flat overcoat resin layer OC, and also forms the photo spacer PSb in the white pixel in the recess of the overcoat resin layer OC formed in the region of the white pixel (W). By doing so, the dent of the overcoat resin layer OC is filled.

(Production method)
Next, a method of manufacturing the color liquid crystal display of the present embodiment will be described with reference to FIGS. 2 and 3.

(Step 1)
First, a light-shielding layer 2 as shown in FIG. 2B is patterned on a transparent substrate 1 as shown in FIG. 2A by any method such as an inkjet method, a printing method, or a photolithography method. ..

The light-shielding layer 2, for example, a colored resin composition in which a pigment is dispersed in a resin together with a photoinitiator and a polymerizable monomer in an appropriate solvent is applied onto a substrate to form a coating film, and a pattern is formed on the coating film. It is formed by exposure and development.

(Step 2)
Next, a colored resin composition in which a pigment is dispersed in a transparent resin together with a photoinitiator and a polymerizable monomer in an appropriate solvent is applied onto a substrate to form a coating film, and the coating film is formed. The step of forming the colored pixels 3 of one color by pattern exposure and development is repeated for each color to form the colored pixels 3 as shown in FIG. 2C.

(Step 3) Formation of Overcoat Resin Layer OC Next, as shown in FIG. 3D, the region of the white pixel (W) and the entire surface on the colored pixel 3 of each color are commonly used by the transparent overcoat resin layer OC. Cover. As a result, the region of the white pixel (W) is filled with the overcoat resin layer OC, and the region of the colored pixel 3 of each color is covered.

In the overcoat resin layer OC, a dent is formed in the region of the white pixel (W).

(Step 4)
ITO is formed into a film by sputtering on the overcoat resin layer OC, and the ITO film is patterned to provide a transparent conductive layer (not shown).

(Step 5) Formation of Photospacer PS Next, as shown in FIG. 3E, photospacer PS is formed on the overcoat resin layer OC and on the transparent conductive layer (not shown) formed by the ITO film. The photospacer PS is formed by a batch pattern forming step of applying a photosensitive resin for use and exposing and developing a photomask pattern on the photomask.

At that time, the photo spacer PSb in the white pixel having the same height as the normal photo spacer PS is formed at the depth of the recess in the region of the white pixel (W).

Thereby, it is possible to form a color filter that fills the dent in the region of the white pixel (W). In this manufacturing method, the photo spacer PS and the photo spacer PSb in the white pixel are formed on the overcoat resin layer OC with a pattern of the same height by a batch pattern forming step.

Since the photo spacer PS and the photo spacer PSb in the white pixel are formed with a pattern of the same height, the pattern of the photo spacer PS and the height of the photo spacer PSb in the white pixel are used in the photo mask that collectively forms the pattern of the photo spacer PS. There is no need to form a halftone cut filter to change, which has the effect of reducing the manufacturing cost of the photomask.

1 ... Transparent substrate 2 ... Light-shielding layer (black matrix)
3 ... Colored pixel 3B ... Blue colored pixel 3G ... Green colored pixel 3R ... Red colored pixel OC ... Overcoat resin layer PS ... Photo spacer PSb ... Photo spacer in white pixel

Claims (4)

A color filter having a light-shielding pattern by a black matrix on a transparent substrate and a display area composed of a plurality of colored pixels and white pixels.
It has a structure in which regions of the plurality of colored pixels and white pixels are commonly covered with a transparent overcoat resin layer, and a photo spacer is formed on the overcoat resin layer.
A color filter characterized in that a photospacer in a white pixel is formed in a recess of the overcoat resin layer on the region of the white pixel to fill the recess. The color filter according to claim 1, wherein the photo spacer in a white pixel has the same height as the photo spacer formed on the overcoat resin layer on the light-shielding pattern and the colored pixel. Color filter. A method for manufacturing a color filter having a light-shielding pattern by a black matrix on a transparent substrate and a display area composed of a plurality of colored pixels and white pixels.
A step of commonly covering the regions of the plurality of colored pixels and white pixels with a transparent overcoat resin layer, and
It has a step of forming a photo spacer on the overcoat resin layer.
A method for manufacturing a color filter, which comprises forming a photospacer in a white pixel in a recess of the overcoat resin layer on the region of the white pixel to fill the recess. The method for manufacturing a color filter according to claim 3, wherein the photo spacer in a white pixel is formed at the same height as the photo spacer formed on the overcoat resin layer on the light-shielding pattern and the colored pixel. A method for manufacturing a color filter characterized by.

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