JPH07239411A - Color filter manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] A black matrix pattern 2 of an ultra-thin light-absorbing and light-shielding film having a two-layer structure of a pre-pattern layer made of a light-absorbing colored photoresist and a light-shielding metal thin film layer on a filter substrate. To prevent the projection-like swelling from overlapping on the end portion of the pattern and to eliminate the increase in the pattern exposure time. [Structure] The pre-pattern layer 11a and the lift-off layer 1
After forming the light shielding metal thin film 13 on the entire surface from above 2a, the light shielding metal thin film 13 corresponding to the upper side of the lift-off layer 12a is lifted off, so that the pre-pattern layer 11a and the light shielding metal thin film are formed on the filter substrate 1. It is a method of manufacturing a color filter in which the black matrix pattern 2 having a two-layer structure is formed by the layer 13a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black filter pattern, Blue, Gre and a transparent filter substrate.
The present invention relates to a method for manufacturing a color filter used in a liquid crystal display device or the like having a filter color pattern composed of en and Red color patterns.

[0002]

2. Description of the Related Art A color filter used in a conventional liquid crystal display device is a glass substrate 1 as shown in FIG.
A black matrix pattern 22 having a light-shielding property (or light-absorbing property) such as a regular lattice pattern or a parallel line pattern is provided on the above,
Blue, Green and Red corresponding to liquid crystal cells (display pixels) are provided between the black matrix patterns 22.
A filter color pattern 25 having a rectangular dot shape, a stripe shape, or the like, which is composed of each coloring pattern, is provided, and the black matrix pattern 22 and the filter color pattern 25
A transparent conductive film (not shown) is laminated on the upper side of the transparent conductive film or transparent protective film as appropriate.

In the above-mentioned color filter, the black matrix pattern 22 and the filter color pattern 25 are closely adjacent to each other so that no void is formed in the adjacent portion of the black matrix pattern 22 and the filter color pattern 25, or as shown in FIG. As in a), they are provided so that their mutual ends overlap.

Generally, the black matrix pattern 22 of a color filter used in a display panel of a liquid crystal display device has a light-shielding property and a low reflectivity (or a light absorbing property) in order to enhance the contrast of a displayed image. Is suitable.

For example, as shown in FIG. 2A, as a color filter in which the black matrix pattern 22 is formed on the glass substrate 1, the glass substrate 1 is formed by a metal deposition method.
A chromium vapor-deposited thin film formed on the above is patterned by a pattern etching method, or a low-reflectivity (light-absorbing) black or dark color pigment dispersed in a photoresist (photo-curing resin). There is an example in which a pattern is formed by using a photofabrication (photolithography method) method.

The chromium vapor-deposited thin film formed by the pattern etching method, as shown in FIG.
The black matrix pattern 22 can be formed in a relatively thin film, and the black matrix pattern 22 and the filter color pattern 25 having a light blocking property and high accuracy can be obtained, but the glossiness and the light reflectance when viewed from the glass substrate surface side are high. Therefore, there is a drawback that the image contrast in a bright place is lowered, and the chromium metal vapor deposition requires a large manufacturing cost as compared with other methods.

[0007]

In addition, a pattern formed by a photofabrication (photolithography) method using a pigment-dispersed photoresist can be manufactured at a relatively low cost as compared with a vapor deposition method and has a low reflectance (light 2B, it is necessary to set the film thickness of the black matrix pattern 22 to be large in order to obtain the light-shielding property (optical density). Therefore, as shown in FIG. 22 R, G, B colored pattern (color pixel) end portions of the filter color pattern 25 overlapping on the end portion are raised and the protruding portion 25a is formed.
Of the black matrix pattern 22 itself, which has a large film thickness, is likely to swell up like a protrusion, and when the color filter and a counter electrode plate facing each other are overlapped, a panel is formed as a liquid crystal display panel device. In addition, the overlapping separation distance as the liquid crystal cell gap becomes non-uniform, which may cause a cell gap defect.

When the film thickness of the black matrix pattern 22 is set to a large value, the pattern exposure light used for forming the pattern is dispersed before passing through the pigment dispersion photoresist film and reaching the surface of the glass substrate 1. The amount of light that is absorbed by the black pigment of the resist film and actually reaches the glass substrate surface is extremely large (for example, 1/100).
.About.1 / 1000), which causes an increase in the exposure time for the pattern exposure, and due to the occurrence of halation on the surface of the glass substrate 1 due to the long exposure time, the accuracy of the pattern edge portion of the black matrix pattern 22 is reduced. There was a problem such as a decrease.

According to the method of the present invention, an ultrathin film black matrix pattern having low reflectivity and light shielding property is formed on a filter substrate by a two-layer structure of a light absorbing colored photoresist layer and a light shielding metal thin film layer. Thus, it is possible to prevent the protrusion of the filter color pattern overlapping on the end portion of the black matrix pattern from rising, and to eliminate the lengthening of the pattern exposure time.

[0010]

According to the present invention, a light absorbing negative type colored photoresist 11 is applied in a thin film form on one surface of a transparent filter substrate 1 and subjected to pattern exposure / development treatment.
A light absorbing pre-pattern layer 11a is formed in a black matrix pattern, then a negative photoresist 12 is applied over the entire surface of the pre-pattern layer 11a, and then the entire surface of the filter substrate 1 is exposed from the other side. The negative photoresist 12 on the pre-pattern layer 11a is removed by development, and the lift-off layer 1 is formed on a portion other than the pre-pattern layer 11a.
2a is formed, and subsequently, a light-shielding metal thin film 13 is formed on the entire surface of the pre-pattern layer 11a and the lift-off layer 12a by metal plating or metal deposition, and then the lift-off layer 12a is dissolved to form the lift-off layer. By lifting off the light-shielding metal thin film 13 corresponding to the upper side of 12a, a black matrix pattern 2 having a two-layer structure of the pre-pattern layer 11a and the light-shielding metal thin film layer 13a is formed on the filter substrate 1, and then the On the surface of the filter substrate 1 other than the portion where the black matrix pattern 2 is formed,
The method for producing a color filter is characterized in that a filter color pattern 5 composed of each of the red, green, and blue coloring patterns is formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for forming a color filter according to the present invention will be described with reference to FIG.
Detailed description will be given below with reference to side sectional views showing the manufacturing steps (a) to (h).

First, as shown in FIG. 1A, a light-absorbing colored photoresist 11 (for example, a light-absorbing black-based material such as a black resist, or a light-absorbing colored photoresist 11 is formed on one surface of a filter substrate 1 such as transparent glass or a plastic plate. A negative photoresist colored with a dark pigment or dye is applied in a thin film form (for example, a film thickness of about 0.1 to 0.3 μm, preferably 0.2 μm) on the entire surface.

Next, as shown in FIG. 1A, from the colored photoresist 11 side, a negative pattern of a photomask P (a black matrix pattern such as a lattice pattern, a stripe pattern, etc., which is a light shielding portion Pa and a black matrix). Pattern exposure by using a light-transmitting portion Pb corresponding to a pattern (projection exposure in an inert gas atmosphere such as nitrogen by blocking oxygen as necessary) or a pattern scanning exposure method. Do.

Subsequently, as shown in FIG. 1 (b), a development process is performed with a developing solution to form a black matrix pattern thin film pre-pattern layer 1 on the exposed and cured portion of the colored photoresist 11.
1a is formed. After the development processing, post-baking is performed at 230 ° C. for about 60 minutes to impart solvent resistance to the pre-pattern layer 11a. The thin film pre-pattern layer 11a
Has an optical density of 0.6 to 1.0, or 0.7 to 1.
About 0 is suitable. The colored photoresist 1
1 is a negative photoresist in which a black pigment is dispersed, and may be either a water-soluble photoresist or an oil-soluble photoresist. For example, CK-2000 (manufactured by Fuji Hunt) is used, and an alkaline aqueous solution is used as a developer. (For example, NaOH; 30 ° C to 40 ° C, 1% aqueous solution) is used.

Next, as shown in FIG. 1C, the pre-pattern layer 11a.
From above, the negative photoresist 12 is applied to the entire surface of the filter substrate 1 to a thickness of about 1 μm to 2 μm.
The resist 12 is the negative photoresist 1 described above.
2 may be either a water-soluble photoresist or an oil-soluble photoresist, but when an oil-soluble photoresist is used as the colored photoresist 11, polyvinyl alcohol-based, acrylic-based, gelatin-dichromic acid-based, etc. It is suitable to use the water-soluble photoresist of In addition, since it will be removed later, it is transparent or opaque.
Alternatively, it may be non-colored or colored, but is preferably transparent or translucent.

Subsequently, the entire surface is exposed from the other surface side of the filter substrate 1 in FIG. 1C, and the light-transmitting portion other than the pre-pattern layer 11a (the portion which is not light-transmitting) in the negative photoresist 12 is exposed. Light cure.

Then, as shown in FIG. 1 (d), development processing is performed with an aqueous developer such as water or alcohol, and the uncured negative photoresist on the pre-pattern layer 11a is left, leaving the lift-off layer 12a in the photo-cured portion. 12 is dissolved and removed.

Next, as shown in FIG. 1E, the pre-pattern layer 11a and the lift-off layer 12a are formed on one surface of the filter substrate 1.
A light-shielding metal thin film 1 made of a metal such as chromium or nickel by using a metal plating method (electroless plating) or a metal vapor deposition method (sputtering vapor deposition, vacuum vapor deposition, etc.) on the entire surface.
3 is deposited. The film thickness of the metal thin film 13 is, for example, 30
It is 0Å to 2000Å, and the metal thin film layer 12 has a light-shielding property of 0.8 to 1.5 or more, or 1.0 to 1.5 or more.

Next, as shown in FIG. 1 (f), the filter substrate 1 is treated with an alkaline aqueous solution (for example, NaOH; 30 ° C. to 40 ° C., 1
% Aqueous solution) for 5 minutes to dissolve and remove the lift-off layer 12a, thereby lifting off (peeling and removing) the metal thin film 13 on the lift-off layer 12a to form a metal thin-film layer 13a on the pre-pattern 11a. The black matrix pattern 2 having a two-layer structure is formed on the filter substrate 1.

Finally, in FIG. 1 (g), on the surface of the filter substrate 1 other than the portion where the black matrix pattern 2 having the two-layer structure is formed, a rectangular dot formed by each of the colored patterns (display pixel patterns) of Red, Green and Blue. The color filter of the present invention is formed by patterning the filter color pattern 5 having a stripe shape, a stripe shape, or the like.

In the present invention, an ITO film (tin indium oxide and tin) having an appropriate pattern is formed on the black matrix pattern 2 and the filter color pattern 5 of the color filter shown in FIG. 1 (g) formed as described above. And a transparent conductive film 6 such as a film). The transparent conductive film 6 is a stripe-shaped scanning electrode pattern (in the case of STN-CF method) by a simple matrix method, or a solid common electrode (TFT in a TFT method).
In the case of the CF method)), it is laminated directly on the black matrix pattern 2 and the filter color pattern 5 or via an insulating transparent protective layer (transparent resin layer).

In the color filter of the present invention, when the filter color pattern 5 is formed, a method similar to the method of forming a filter color pattern of a conventionally known color filter, for example, transparent with good dyeability such as gelatin. The relief dyeing method using a photosensitive solution and each dye of Blue, Green, and Red, and the above-mentioned Blue, Green
n, Red pigment dispersion photoresist method using each pigment dispersion photoresist, Blue, Green, Red
By an organic filter color pattern forming method by a printing method such as an intaglio offset printing method using each colored printing ink of
Black matrix pattern 2 and filter color pattern 5
The filter color pattern 5 such that the edge portions thereof are closely adjacent to each other or the filter color pattern 5 overlaps the black matrix pattern 2 at the edge portions thereof.
To form a pattern.

In the present invention, in FIG. 1 (e), the metal thin film 13 is formed by a metal deposition method or an electroless plating method. An example is shown below.

In FIG. 1D, the pre-pattern 11a
And the filter substrate 1 on which the lift-off layer 12a is formed,
If necessary, after degreasing with a weak acid solution and washing with water, sodium borohydride or sodium hypophosphite (reducing agent) 1 to 5% by weight, or 5 g / 1000 cm ³
Immerse in an aqueous solution (room temperature) for 1 to 3 minutes, perform sensitizing treatment, and wash with water. Then, palladium chloride 0.2
~ 1 wt% aqueous solution and 0.5 vol% hydrochloric acid aqueous solution (room temperature) or palladium chloride aqueous solution (0.2 g /
1000 cm ³ ) and sodium tartrate solution (0.3
g / a 1000 cm ^3), aqueous hydrochloric acid (3 cm ^3/10
2 to a mixed solution (pH; 6.3, room temperature) with 00 cm ³ )
It was dipped for 5 minutes, activated, and washed with water.

Then, the nickel metal salt solution (60 ° C. to 90 ° C.) such as nickel sulfate solution or nickel chloride solution is added to
By immersing for 5 minutes and washing with water, the filter substrate 1
A nickel plating layer was formed on the pre-pattern 11a and the lift-off layer 12a. As the nickel metal salt solution, for example, a mixed solution of an aqueous solution of Nimden LPX-A (manufactured by Uemura Industry Co., Ltd.) and an aqueous solution of Nimden LPX-M (manufactured by Uemura Industry Co., Ltd.) (temperature: 60 ° C. to 90 ° C., pH) ; 4.
5) can be used, and the composition of the mixed solution is as follows.・ Nimden LPX-A / Water ・ ・ ・ 450cm ³
/ 1000cm ³ · Nimden LPX-M / Water: 200cm ³
/ 1000 cm ³

As the light-absorbing negative colored photoresist 11 used in the method of the present invention, an acrylic resin, a polyester resin or a urethane resin which can be developed with an alkaline aqueous solution or an organic solvent such as alcohol or toluene. A resin, an epoxy resin, a synthetic resin such as a polyamide resin, or an oil-soluble photocurable resin mainly composed of a composite resin obtained by combining any of these resins is suitable. A low-reflecting (light-absorbing) black or black or dark pigment or dye is mixed in a dispersed state.

Further, in the method of the present invention, the lift-off layer 1
As the negative photoresist 12 used as 2a, a polyvinyl alcohol-based, gelatin-dichromate-based, acrylic-based water-soluble negative photoresist that can be developed with water or an aqueous solvent (alkaline aqueous solution) is used. Is appropriate.

The metal for forming the light-shielding metal thin film 13 by a metal plating method or a metal vapor deposition method is nickel, chromium, copper, aluminum, or any of these metal oxides. Can be used.

[0029]

The method of the present invention has a two-layer structure comprising a light-absorbing thin film-like pre-pattern layer 11a on the filter substrate 1 and a light-shielding metal thin-film layer 13a laminated on the pre-pattern layer 11a. Since the black matrix pattern 2 is pattern-exposed from the front surface or the back surface of the filter substrate 1 and formed by the lift-off method, the black matrix pattern 2 having good compatibility can be obtained in the formation of the two layers.

The black matrix pattern 2 obtained by the method of the present invention has a thin film-like pre-pattern layer 11.
a and a thin metal thin film layer 13a, which is also a thin film, are formed into an ultra-thin film, so that when the filter color pattern 5 overlaps the end of the black matrix pattern 2, a protrusion due to the overlap is formed. The height can be reduced and the formation of protrusions can be suppressed.

Although the black matrix pattern 2 in the present invention is an extremely thin film, the pre-pattern layer 11
Since a has a light absorbing property and the metal thin film layer 13a has a light shielding property, a synergistic optical density due to the two-layer structure can be obtained, for example, from 2.0 to 2.5 or more. Sufficient light shielding property and light absorbing property (low reflectivity) as the pattern 2 can be obtained.

Further, in the method of the present invention, since the light absorbing colored photoresist is applied in a thin film form and used, the pre-pattern 11 as the black matrix pattern 2 is used.
It is possible to prevent the exposure time from increasing in the pattern formation of a.

[0033]

The method of manufacturing a color filter according to the present invention comprises:
The black matrix pattern 2 having a two-layer structure having a light absorbing property (low reflectivity) and a light shielding property can be formed into a pattern with good matching between the two layers, and the light shielding property and the low reflective property sufficiently improve the contrast of the display image. It is possible to manufacture a colored filter which is made possible, and to prevent the lengthening of the pattern exposure time, to eliminate the risk of halation on the filter substrate surface during pattern exposure, and to improve the accuracy of the black matrix pattern edge portion. Has the effect of.

[Brief description of drawings]

1A to 1H are schematic side cross-sectional views of a manufacturing process for explaining a method for manufacturing a color filter of the present invention.

2A and 2B are schematic side sectional views illustrating a conventional color filter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Filter substrate 2 ... Black matrix pattern 5 ... Filter color pattern 6 ... Transparent conductive film 11 ... Colored photoresist 11a ... Pre-pattern 12 ... Negative photoresist 12a ... Lift-off layer 13 ... Light-shielding metal thin film 13a ... Metal thin film layer 22 ... Black matrix pattern 25 ... Filter color pattern 25a ... Projection B ... Blue (blue) G ... Green (green) R ... Re
d (red) L ... exposure P ... photomask Pa ... light-shielding portion Pb ... light-transmitting portion

Claims (2)

[Claims] 1. A light-absorbing negative-type colored photoresist 11 is applied as a thin film on one surface of a transparent filter substrate 1 and subjected to pattern exposure / development treatment, and a light-absorbing pre-pattern layer in a black matrix pattern. 11a is formed, and then a negative photoresist 12 is applied over the entire surface of the pre-pattern layer 11a. Then, the entire surface of the filter substrate 1 is exposed from the other surface side, and the negative photoresist on the pre-pattern layer 11a is formed. 12 is removed by development to form a lift-off layer 12a on a portion other than the pre-pattern layer 11a, and subsequently, the light-shielding metal thin film 1 is formed on the entire surface of the pre-pattern layer 11a and the lift-off layer 12a by metal plating or metal deposition.
3, the lift-off layer 12a is dissolved and the light-shielding metal thin film 13 corresponding to the upper side of the lift-off layer 12a is lifted off, so that the pre-pattern layer 11a and the light-shielding metal thin film layer are formed on the filter substrate 1. 13a to form a black matrix pattern 2 having a two-layer structure,
Then, on the surface of the filter substrate 1 other than the portion where the black matrix pattern 2 is formed, Red, Green, and Blue are formed.
A method of manufacturing a color filter, which comprises forming a filter color pattern 5 composed of each coloring pattern of e. 2. The method of manufacturing a color filter according to claim 1, wherein a water-soluble negative photoresist is used as the negative photoresist 12.