JPH06308315A - Pattern forming method for colored paste for colored filter - Google Patents

Abstract

PURPOSE:To improve developability and the cut of patterns, to widen the latitude of development and to improve a yield by selectively exposing colored paste after prebaking, then developing this colored paste by using an aq. soln. contg. at least an alkaline and an org. solvent without contg. an amino group. CONSTITUTION:The photosensitive or nonphotosensitive colored paste for the colored filter contg. a polymer having a carboxyl group is applied on the transparent substrate and is selectively exposed after prebaking. The colored paste is then developed after exposing to remove the exposed parts or unexposed parts of the colored paste. The aq. soln. contg. at least the alkaline and the org. solvent without contg. the amino group is used as the developer at this time. The org. solvent without contg. the amino group is soluble in water and contains at least one kind selected from a group consisting of 2 to 6C alcohol, ketone, cellosolve, ether, ester, amide and suslfoxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a pattern of a color filter colored paste used for a color filter suitable for a color liquid crystal display device such as a color liquid crystal television or a computer color liquid crystal display.

[0002]

2. Description of the Related Art As a method of forming a colored pattern used for a color filter, there are a printing method, an electrodeposition method, a photolithography method and the like. Among these, the photolithography method is a method in which a colored paste is applied on a substrate, pre-baked, selectively exposed, and subsequently developed, and when the colored paste is a negative type, the exposed portion swells, and In the case of the positive type, development is carried out by dissolving the exposed portion. As the coloring paste used in the photolithography method, for example, a coloring paste containing a polymer having a carboxyl group is used. Conventionally, when such a colored paste is used, only an alkaline aqueous solution such as an aqueous sodium carbonate solution is used as a developing solution (Japanese Patent Laid-Open No. 1-1999).
152449, JP-A-1-102429, JP-A1-2
54918, JP-A-2-166452, etc.).

[0003]

However, when development is carried out only with an aqueous alkaline solution, the difference in the adhesiveness or the solubility in the exposed area and the unexposed area of the colored pattern due to the swelling in the developing solution due to the swelling in the developing solution. Was small, and as a result, there were problems such as low developability and unclear pattern edges. Therefore, there is a problem that, for example, the edge of the black matrix is poorly cut off, resulting in unevenness and disconnection of the ITO wiring.

The present invention was devised in view of the above-mentioned drawbacks of the prior art. The object of the present invention is to form a pattern on a transparent substrate using a colored paste containing a polymer having a carboxyl group. In order to improve the developability and breakage of the pattern, and to widen the allowable range of development, the yield is improved.

[0005]

An object of the present invention is to apply a photosensitive or non-photosensitive color filter color paste containing a polymer having a carboxyl group onto a transparent substrate.
This is achieved by a method for forming a pattern of a colored paste for a color filter, which comprises pre-baking, followed by selective exposure, followed by development using an aqueous solution containing at least an alkali and an organic solvent containing no amino group.

The colored paste used in the present invention contains a polymer having a carboxyl group.
As the polymer having a carboxyl group, an acrylic type, an imide type, having one or more carboxyl groups in the molecular chain,
Examples thereof include melamine-based, phenol-based, amide-based, urethane-based, ester-based, epoxy-based, and ether-based synthetic resins, petroleum resins, and natural resins. Specific examples include copolymerized polymers containing acrylic acid, polyamic acid as a polyimide precursor, and carboxyl-modified polyurethane. These polymers may be used alone or in admixture of two or more.

Colored pastes include those having photosensitivity and those having no photosensitivity.

The composition of the photosensitive coloring paste usually contains the above-mentioned polymer, coloring component, polyfunctional monomer, sensitizer and organic solvent.

The composition of the non-photosensitive coloring paste usually contains the above-mentioned polymer, coloring component and organic solvent.

Here, as the coloring component, conventionally known ones such as organic pigments such as red, green, blue or black, inorganic pigments and dyes are used. Red, green, and blue serve as pixels on the transparent substrate, and black serves as a light-shielding layer between the pixels.
These coloring components may be used alone or in admixture of two or more. As the organic solvent, a conventionally known general organic solvent can be used, and examples thereof include alcohol-based, ester-based, ketone-based and ether-based solvents.

The polyfunctional monomer is a monomer having two or more ethylenically unsaturated bonds. For example, neopentyl glycol diacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, or methacrylates thereof.

The sensitizer is capable of generating a radical by light, and examples thereof include α-aminoacetophenone, anthraquinone, benzoin ether, benzophenone and the like.

A pattern is formed on the transparent substrate using the above-mentioned colored paste.

First, the colored paste is applied onto a transparent substrate using a spinner, roll coater, die coater or the like.
The coating film thickness is usually about 1.0 to 3.0 μm.

After coating, prebaking is performed using a hot air oven, hot plate, or the like. The prebaking condition varies depending on the type of polymer used, the type of solvent, etc., but is usually about 60 to 90 ° C. and about 3 to 10 minutes.

In the case of a photosensitive colored paste, after prebaking, it is selectively exposed to ultraviolet light using an ultrahigh pressure mercury lamp, a chemical lamp, a high pressure mercury lamp or the like. As a method of exposure, it is general to irradiate with ultraviolet rays or the like using a mask having a predetermined pattern. However, in the case of the black colored paste which becomes the light-shielding layer, if pixels are already formed, it is also preferable to perform exposure from the back side of the substrate using the pixels as a mask. When the exposure is performed from the back side, the pixel serves as a mask, and there is an advantage that the problem of misalignment does not occur.

In the case of a non-photosensitive colored paste, a positive type resist is applied after prebaking, and it is selectively exposed to ultraviolet rays through a mask using an ultrahigh pressure mercury lamp, a chemical lamp, a high pressure mercury lamp or the like. As a positive resist,
A general photoresist such as a microposit can be used.

After the exposure, development is performed to remove the exposed or unexposed portion of the colored paste. Here, as the developer,
It is important to use an aqueous solution containing an alkali and an organic solvent containing no amino group.

Examples of the alkali include, but are not limited to, aqueous solutions of sodium hydroxide, sodium carbonate, monoethanolamine, diethanolamine, triethanolamine, diethylamine, triethylamine and the like. These alkalis may be used alone or in combination of two or more. Alkali is 0.5 to 3 in the developing solution.
It is preferably contained in a weight percentage. More preferably,
It is 0.5 to 1% by weight. If it exceeds 3% by weight, the sharpness of the pixel is not sharp and undulation occurs at the interface of the pixel, which is not preferable.

As the organic solvent containing no amino group, any known organic solvent containing no amino group in its structural formula is preferably used. More preferred are alcohols, ketones, cellosolves, ethers, esters, amides, sulfoxides, etc., which are water-soluble and have 2 to 6 carbon atoms, and more preferably n-propanol, methyl ethyl ketone, methyl cellosolve, 1,4-
Dioxane, ethyl acetate, N, N-dimethylacetamide, dimethyl sulfoxide. These organic solvents may be used alone or in admixture of two or more. The organic solvent is preferably contained in the developer in an amount of 0.3 to 5% by weight. More preferably, it is 0.5 to 4% by weight. 5
If it exceeds 5% by weight, the exposed portion is peeled off and the development allowable width is narrowed, which is not preferable.

Additives may be added to the developer within a range that does not impair the effects of the developer.

As the developing method, dipping in a developing solution,
Examples of the method include applying ultrasonic waves and spraying a developing solution while immersing in the developing solution. For example, when immersing in the developing solution, it may be immersed for about 1 minute. After the completion of development, it is preferable to rinse with water or the like.

The method of the present invention is an effective technique for both photosensitive and non-photosensitive color filter color pastes.

[0024]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 N-methylpyrrolidone solution of polyamic acid (25 wt
%) With a red, green, and blue organic pigment dispersed therein to prepare a colored paste. Each of these colored pastes was applied onto a glass substrate with a spinner, and a pattern was formed by an ordinary method using an etching method using a positive resist. When the pattern formation for the first color is completed, 300 ° C
Post-baking was performed for 1 hour, pattern formation was performed for the second color, and post-baking was performed again at 300 ° C. for 1 hour.
Further, a pattern for the third color was formed, and post-baking was performed at 300 ° C. for 1 hour to form R, G, B patterns. At this time, a gap of 15 μm for the light shielding layer was provided between the respective colors.

On the pattern thus created,
5% by weight of acrylic polymer obtained by copolymerizing acrylic acid, styrene and methyl methacrylate in the same amount, 3% by weight of trimethylolpropane triacrylate, 6% by weight of carbon black, 5% by weight of polyvinyl butyral, 1% by weight of α-aminoacetophenone and 80% of butyl cellosolve. The photosensitive black paste for forming a light-shielding film dispersed in a bead mill was added to the pixel forming surface with a spinner, and dried at 80 ° C. for 5 minutes. The film thickness at this time was 1.5 μm. Next, exposure was performed from the back side of the substrate.

1% by weight of monoethanolamine on this substrate
And 1% by weight of methyl cellosolve were immersed in an aqueous solution at 20 ° C. for 1 minute. The substrate was taken out, immersed in water for 30 seconds, sprayed with water and washed with water. The black paste remained faithfully between the R, G and B pixels and a black matrix could be formed. The break of the black matrix around the substrate was sharp and could be straight. Moreover, a flat pattern having no unevenness was obtained.

No. 1 in Table 1 The results are shown in 1.

Example 2 R, G, and B patterns were formed, black paste was applied, and back exposure was carried out in the same manner as in Example 1 to obtain 0.5% by weight of monoethanolamine at 20 ° C. and 2% by weight of n-propanol.
It was immersed in an aqueous solution containing 20 ° C. for 1 minute. The substrate was taken out, immersed in water for 30 seconds, sprayed with water and washed with water. The black paste remained faithfully between the R, G and B pixels and a black matrix could be formed. Example 1
Similarly, the breakage of the black matrix around the substrate could be sharp and straight. Moreover, a flat pattern having no unevenness was obtained.

No. 1 in Table 1 The results are shown in 2.

Example 3 R, G, and B patterns were formed, black paste was applied, and back exposure was performed in exactly the same manner as in Example 1 to contain 0.5% by weight of monoethanolamine at 20 ° C. and 4% by weight of methyl ethyl ketone. It was immersed in an aqueous solution at 20 ° C. for 1 minute. The substrate was taken out, immersed in water for 30 seconds, sprayed with water and washed with water. The black paste remained faithfully between the R, G and B pixels and a black matrix could be formed. As in Example 1, the breakage of the black matrix around the substrate was sharp and could be a straight line. Moreover, a flat pattern having no unevenness was obtained.

No. 1 in Table 1 The results are shown in 3.

Example 4 In exactly the same manner as in Example 1, 10% by weight of acrylic polymer and 10% by weight of carbon black obtained by copolymerizing acrylic acid, styrene and methyl methacrylate in the same amount on a substrate on which R, G and B patterns were formed. , 80% by weight of butyl cellosolve was added, and a black paste for forming a light shielding film dispersed in a bead mill was applied with a spinner and dried at 80 ° C. for 5 minutes. The film thickness at this time was 1.5 μm. Next, a positive resist is applied to the entire surface of this black paste using a spinner, and the temperature is 90 ° C.
-It was dried for 10 minutes, and was selectively exposed by irradiating it with ultraviolet rays through a mask.

This substrate was immersed in an aqueous solution containing 0.5% by weight of monoethanolamine and 2% by weight of n-propanol at 20 ° C. for 1 minute. Take out the substrate and put it in water for 30
After soaking for a second, a water spray was applied to wash with water. As in Example 1, the breakage of the black matrix around the substrate was sharp and could be a straight line. Moreover, a flat pattern having no unevenness was obtained.

Example 5 In exactly the same manner as in Example 1, 10% by weight of polyimide resin (“Semicofine” manufactured by Toray Industries, Inc.), 10% by weight of carbon black, and butyl cellosolve were formed on a substrate on which R, G, and B patterns were formed. 80% by weight was added, and a black paste for forming a light-shielding film dispersed in a bead mill was applied with a spinner, and the temperature was 90 ° C.
-It dried for 10 minutes and 125 degreeC and 20 minutes. The film thickness at this time was 1.0 μm. Next, a positive resist is applied to the entire surface of the black paste by using a spinner,
After drying at 0 ° C. for 10 minutes, ultraviolet rays were radiated through a mask to selectively expose it.

This substrate was immersed in an aqueous solution containing 0.5% by weight of monoethanolamine and 2% by weight of n-propanol at 20 ° C. for 1 minute. Take out the substrate and put it in water for 30
After soaking for a second, a water spray was applied to wash with water. As in Example 1, the breakage of the black matrix around the substrate was sharp and could be a straight line. Moreover, a flat pattern having no unevenness was obtained.

Comparative Example 1 R, G, and B patterns were formed, black paste was applied, and back exposure was performed in exactly the same manner as in Example 1, and 1% by weight at 20 ° C.
It was immersed in an aqueous solution of sodium carbonate for 1 minute. The substrate was taken out, immersed in water for 30 seconds, sprayed with water and washed with water. The breakage of the black matrix around the substrate was very bad, there were countless mountain-shaped residual films of about 40 μm from the end face, and numerous projections and bumps at the interface where the roughness was over 1 μm were seen.

No. 1 in Table 1 The results are described in 4.

Comparative Example 2 R, G, and B patterns were formed, black paste was applied, and back exposure was performed in exactly the same manner as in Example 1, and 1% by weight at 20 ° C.
It was immersed in a monoethanolamine aqueous solution for 1 minute. The substrate was taken out, immersed in water for 30 seconds, sprayed with water and washed with water. Similar to Comparative Example 1, the black matrix around the substrate was very poorly cut and became an end face with severe irregularities.

No. 1 in Table 1 The results are described in 5.

[0041]

[Table 1] The evaluation of breakage and unevenness in Table 1 was performed according to the following criteria.

The breakage of the colored paste was evaluated with a 50 × optical microscope. ◯: The end surface of the colored paste has a flat shape x: Innumerable mountain-shaped residual films are found on the end surface of the colored paste The unevenness of the end surface was evaluated by a thin film step measuring instrument in which the height direction was enlarged 10,000 times. ◯: The protrusions on the end faces of the colored paste are flat ×: The protrusions on the end faces of the colored paste are large

[0043]

The pattern of the colored paste obtained by the developing method of the present invention is not broken because the swelling property is enhanced by the organic solvent and the property of the film is changed and the boundary between the exposed portion and the unexposed portion becomes clear. Improves and obtains flat edges without irregularities. Further, since the allowable range of development is widened, the yield is improved. As a result, a high quality and high yield color filter can be manufactured.

Claims (2)

[Claims] 1. A photosensitive or non-photosensitive color filter color paste containing a polymer having a carboxyl group is applied on a transparent substrate, pre-baked, and then selectively exposed to light, followed by containing at least an alkali and an amino group. A method for forming a pattern of a colored paste for a color filter, which comprises developing with an aqueous solution containing an organic solvent that does not exist. 2. An organic solvent containing no amino group is water-soluble,
The pattern formation of a colored paste for a color filter according to claim 1, further comprising at least one selected from the group consisting of alcohols, ketones, cellosolves, ethers, esters, amides and sulfoxides having 2 to 6 carbon atoms. Method.