JPH0694912A - Production of color filter - Google Patents

Abstract

PURPOSE:To improve the precision in alignment at the time of producing a color filter. CONSTITUTION:Striped patterns 4 each having a width necessary to form a black matrix and consisting of the black resist are formed on a glass substrate with the spacing almost equal to the width of a picture element. A colored ink 5 is printed between the patterns 4, and the ink 5 is pressed and spread between the patterns 4 and dried. Striped patterns 6 each consisting of the black resist with the spacing almost equal to the length of the picture element are formed orthogonally to the pattern 4. The recess between the crossed and striped patterns is filled with a transparent ink 3 to produce a color filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color filter having excellent alignment accuracy. The color filter in the liquid crystal display panel is provided on the glass substrate on the light source side, and the transparent electrode is patterned on the glass substrate via the overcoat layer.

Here, the color filter is composed of filters of three primary colors such as red (R), green (G) and blue (B), and each primary color corresponding to each pixel provided in the liquid crystal panel. Since the filter is provided, by placing a white light source on the back surface, color display by additive color mixing can be performed similarly to the color CRT.

There are various methods for producing a color filter used for a color liquid crystal panel, such as a printing method, a dyeing method, a pigment dispersion method and an electrodeposition method. The present invention relates to the printing method.

[0004]

2. Description of the Related Art A color filter is formed by forming a black matrix on a glass substrate using a chrome (Cr) metal film or a black resist, and sequentially printing red, green, and blue ink in the gaps by an offset printing method. is doing.

That is, a Cr thin film is formed on a glass substrate by a sputtering method, or a black resist is applied by a spin coating method, and a pattern is formed by using a photo-etching technique (photolithography). A black matrix (light-shielding layer) in which stripe patterns that do not pass light intersect at right angles is created, and the red, green, and blue inks are sequentially printed in this gap using the offset printing method. There is.

However, when the offset printing method is used for printing, the printing accuracy in the lateral direction is good, but the printing accuracy in the transfer progressing direction is not sufficient, so that all the gaps in the black matrix are accurate. It is difficult to print well.

The color filter according to the present invention uses a black resist. When a black resist is used, a film thickness of at least 1 to 2 μm is required to have a light blocking effect. Since the walls are present on all sides due to the ink film thickness, a decrease in printing accuracy was unavoidable.

[0008]

In a color filter that forms a black matrix using a black resist, when red, green, and blue inks are sequentially printed by the offset printing method, the transfer progress direction by the offset printing method. Since the positional accuracy of (1) is inferior to the lateral positional accuracy, it is difficult to print the ink in all the gaps of the black matrix with high positional accuracy, and the manufacturing yield is reduced.

[0009]

The above-mentioned problem is to form a stripe-shaped pattern made of a black resist on a glass substrate, the stripe pattern having a line width required for forming a black matrix and having a pitch substantially equal to a lateral dimension of a pixel. Printing the colored ink between the striped patterns, pressing the colored ink, rolling between the striped patterns, and then drying, and a step of orthogonally intersecting the striped patterns with a vertical spacing of pixels. A method of manufacturing a color filter is characterized in that it comprises a step of forming a stripe-shaped pattern made of a black resist having substantially the same size, and a step of filling a recess between the intersecting stripe-shaped patterns with a transparent ink. It can be solved by

[0010]

The present invention changes the method of forming the black matrix. FIG. 3 shows a configuration of a conventional color filter, (A) is a plan view, and (B) is XX ′.
It is a partial cross-sectional enlarged view of a line position.

That is, after forming a black resist film on the glass substrate 1 by a spin coating method, a black matrix 2 having a gap of a pixel size is formed by using a photo-etching technique, and then this black matrix is formed. Use the offset printing method in the gap of 2 and divide it into three parts, red, green,
By repeating the process of transferring any of the blue inks, applying pressure, and drying, for example, R (red), G (green), and B are formed in the gaps of the black matrix 2 as shown in FIG.
The ink layer 3 in which the (blue) ink was sequentially arranged was formed.

However, the size of the gap of the black matrix having the same size as the pixel is small, for example, about 70 μm × 330 μm. Since the positional accuracy in the vertical direction is not sufficient for printing, misalignment occurs and the black matrix There is a problem that the ink layer 3 overlaps with 2.

Therefore, in the present invention, the black matrix pattern forming step is divided into two steps so that the vertical printing accuracy does not become a problem, and first, a vertical stripe pattern having an interval equal to the horizontal dimension of the pixel is formed. , R (red), G (green), and B (blue) inks are sequentially arranged in the respective gaps, and then a horizontal stripe pattern having an interval equal to the vertical dimension of the pixel is formed thereon. Thus, a black matrix having a two-layer structure is formed.

FIG. 1 shows this step, which is shown in FIG.
Is a plan view, and FIG. 6B is a partially enlarged cross-sectional view. That is, after a black resist film is formed on the glass substrate 1 by a spin coating method, a vertical stripe pattern 4 having an interval equal to the lateral dimension of a pixel is formed by using a photo-etching technique, and an offset is provided in this gap. For example, R (red) ink 5 is transferred using a printing method. (Above A-1, B-
1) Next, an ink layer made of the R (red) ink 5 is pressed by using an ink-phobic roller to fill the space between the stripe-shaped patterns 4 and then dried by heating. (Above A-2, B-2) The same operation is performed using G (green) and B (blue) inks to form the ink layer 3 of three primary color inks.

Next, a black resist film is formed on this by a spin coating method, and then a lateral stripe pattern 6 having intervals equal to the vertical dimension of the pixel is formed by using a photo-etching technique. (Above, A-3, B-3) However, in this case, since the stripe pattern 6 in the horizontal direction is formed at intervals equal to the vertical dimension of the pixel, the surface has irregularities.

FIG. 2B-4 is a sectional view taken from the direction in which the stripe-shaped pattern 4 is viewed from the side by changing the direction. Therefore, if the transparent ink 8 is spin-coated on the recesses 7 formed between the stripe patterns 6 in the lateral direction, the recesses 7 can be filled and flattened. (Above B-5) Next, in order to further improve mechanical protection and moisture resistance, a polyimide resin, an acrylic resin, or the like may be applied onto the transparent protective film 9 to form it.

According to the present invention, the black matrix is thus formed by the two-layer structure, and thereby the positional deviation that tends to occur when the ink layer 3 is formed is eliminated.

[0018]

[Example] The glass substrate for forming the color filter is a borosilicate glass substrate having a thickness of 1.1 mm, and a black resist having a thickness of 1.5 μm is applied thereon by a spin coating method, followed by photo-etching. Using the technology, a stripe pattern with a width of 40 μm and a pattern pitch of 110 μm was formed.

Next, the R (red) ink is printed between the stripe-shaped patterns by the offset printing method so as to have a line width of 70 μm and a film thickness of 4 μm, and the printed ink is pressed by using a silicone rubber roller to press the stripe-shaped patterns. It was extended between the two and flattened, and then irradiated with ultraviolet light to be cured.

This step was performed using G (green) and B (blue) inks to form an ink layer on the glass substrate. Next, a black resist 1.5
After coating to a thickness of μm, a width of 40
A horizontal stripe-shaped pattern having a pattern pitch of 330 μm with a size of μm was formed, thereby completing the black matrix.

Next, a transparent ink (ink containing no pigment) was applied on the surface by spin coating to make the surface flat. Next, a polyimide resin dissolved in a solvent was formed to a thickness of 1 μm by a spin coating method and heated at 200 ° C. to be cured to form a transparent protective film, whereby a color filter having excellent moisture resistance was completed.

[0022]

By implementing the present invention, it is possible to manufacture a color filter with good ink layer alignment accuracy, thereby improving the quality of the color liquid crystal display device.

Although the offset printing method is used as the printing method, the same result can be obtained by using the screen printing method.

[Brief description of drawings]

FIG. 1 is a plan view and a cross-sectional view (1) showing a process of the present invention.
Is.

FIG. 2 is a sectional view (2) showing a process of the present invention.

FIG. 3 is a plan view (A) and a sectional view (B) showing a configuration of a conventional color filter.

[Explanation of symbols]

 2 Black matrix 3 Ink layer 4 Striped pattern 5 Red ink 6 Horizontal stripe pattern 7 Recesses 8 Transparent ink 9 Transparent protective film

Claims (1)

[Claims] 1. A step of forming a stripe-shaped pattern made of a black resist having a line width required for forming a black matrix on a glass substrate and having an interval substantially equal to a lateral dimension of a pixel, and between the stripe-shaped pattern. After printing the colored ink, pressing the colored ink, rolling it between the stripe patterns, and then drying, and a black resist that is orthogonal to the stripe pattern and has an interval substantially equal to the vertical dimension of the pixel. A method of manufacturing a color filter, comprising: a step of forming a stripe pattern; and a step of filling a recess between the intersecting stripe patterns with a transparent ink.