JP2701896B2 - Manufacturing method of color filter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a color filter, and more particularly, to a method for manufacturing a color filter by a photolithography dyeing method.

[Conventional technology]

Color filters used in liquid crystal display devices and solid-state imaging devices are generally glass, plastic, imaging devices,
On a substrate such as a thin film transistor, fine colored pixels of a plurality of colors are sequentially and repeatedly formed, and a protective film is formed thereon.

Such a color filter is generally formed by a method described below.

A) Photolithography method A protein such as gelatin, casein or glue, or a water-soluble polymer obtained by introducing a staining group into polyvinyl alcohol or the like, and a dichromate or diazo compound on the surface of a transparent glass substrate. A method of making a plate using a photocrosslinking agent and sequentially forming colored pixels by a dyeing process.

B) Printing method A method in which pigments or dyes having good transparency are dispersed in a vehicle, and each colored pixel is sequentially formed by a screen printing method, an offset printing method, a flexographic intaglio printing method, or the like.

C) Electrodeposition method The ionized pigment is dispersed in water, a voltage is applied to the transparent electrode that has been patterned in advance, and the ionized pigment is deposited on the transparent electrode. How to get.

D) Evaporation method Sublimable pigments are deposited on a transparent substrate in a high vacuum,
Colored pixels are sequentially obtained by a lift-off method or an etching method, or a low refractive index material such as MgF, SiO ₂ and Zr
A method in which high refractive index substances such as O ₂ , TiO ₂ , and ZnS are alternately deposited to a predetermined thickness to form a multilayer interference thin film, and then a colored pixel is sequentially obtained by a lift-off method or an etching method.

Among the above color filter manufacturing methods, the one most commonly used is a combination of a photolithography method and a dyeing method. Such a manufacturing method will be described with reference to FIGS. 2 (A) to 2 (E). That is, a transparent relief image 2 is formed on the surface of the substrate 1 using a dyeable photosensitive resin.
Which is dyed with an acid dye or a reactive dye,
The first colored pixel 3 is obtained. Next, this colored pixel 3
Is subjected to a hardening treatment or a transparent resin is applied and cured to perform an anti-dyeing treatment. Thereafter, other colored pixels 4 and 5 are sequentially formed in the same process, and finally, a transparent resin is applied and cured to form the protective film 6.
To obtain a desired color filter.

A color filter obtained by a manufacturing method combining photolithography and staining is a method of obtaining colored pixels by adsorbing a dye such as an acid dye to a dye substrate composed of proteins such as gelatin, casein, and glue. It is. That is, the color is formed by forming a salt with the amino group in the protein and the sulfonic acid group in the acid dye. In addition, the adsorption of the acidic dye to the dye substrate composed of protein is also carried out by hydrogen bond and van der Waals bond, but the above-mentioned adsorption is predominant due to the formation of the salt between the amino group and the sulfonic acid group.

[Problems to be solved by the invention]

However, the conventional method for manufacturing a color filter as described above has problems to be solved as described below. In other words, when dyeing sequentially with dyes,
The dye dyed later may be dyed on the dyed pixel dyed earlier, causing color mixing. In addition, this phenomenon similarly occurs when an anti-dyeing method using a hardening treatment or an anti-dyeing method in which a transparent resin is applied and cured is used.

When such color mixing occurs, the spectral characteristic of each colored pixel changes, deviates greatly from the reference spectral characteristic, and causes a large decrease in yield.

The present invention has been proposed in order to solve the above-described problems of the related art, and an object of the present invention is to provide a method of manufacturing a color filter capable of obtaining a high-precision color filter in which color mixing is prevented. is there.

[Means for solving the problem]

The present inventor, in order to achieve the above object, focused on the affinity between the amino group and the acid dye in the protein that is a staining substrate, and as a result of the examination, as the affinity between the amino group and the acid dye in the protein was larger, It has been found that the previously dyed dye is difficult to be desorbed.

In addition, the present inventor believes that during the color filter manufacturing process, the colored pixels are mixed by the subsequent dyeing because the dye previously dyed is desorbed and the dye dyed later is adsorbed on the pixels. Focusing on this fact, the present inventors have found a method for producing a color filter of the present invention.

That is, the method of manufacturing a color filter according to the present invention is characterized in that the formation of colored pixels on the substrate is performed in order of increasing affinity between the dye substrate and each dye.

Examples of the staining substrate used in the present invention include proteins such as gelatin, casein, and glue, and polyvinyl alcohol.

Further, as the dye for dyeing the dye substrate, an acid dye or a reactive dye can be used. As these dyes, for example, general acid dyes, level dyeing acid dyes,
A wide variety of dyes can be applied, such as semi-leveling acid dyes, milling acid dyes, metal-containing complex hydrochloric acid dyes, or cold-type reactive dyes and hot-type reactive dyes.

Hereinafter, the specific contents of the present invention will be described with reference to the drawings.

FIG. 1 shows transmission spectral characteristics indicating that color mixing differs depending on the color order according to the present invention. (A) shows blue (stained with Solway Blue R) pixels first and then 1% tannin. This shows the change in transmission spectral characteristics when immersed in an erythro (metanyel yellow YK) dyeing bath after hardening treatment with an acid and passing through a dye-proofing process. This shows a change in characteristics.

As shown in FIG. 1 (A), the transmission spectral characteristics after staining with Solway Blue R were measured by Metanil Yellow YK
It is maintained even when immersed in a dye bath. On the other hand, as shown in FIG. 1 (B), when the dyeing with Metanil Yellow YK was carried out first, the transmission spectral characteristics after the dyeing were marked when immersed in a Solway Blue R dyeing bath later. Change. This is because the dye of metaneil yellow YK dyed earlier is desorbed,
This shows that Solway Blue R stained later is adsorbed.

Also, the affinity of Solway Blue R and Metanil Yellow YK for proteins is about
5.2 Kcal, Solway Blue R is about 6.5 Kcal. The method for measuring the affinity of each dye for protein is as follows.
Although various proposals have been made, if it is sufficient to measure only the magnitude relationship between the affinity of the two dyes, the two dye baths to be measured are mixed, and the dye substrate is simultaneously dyed. Can be determined to have a higher affinity.
Therefore, if the affinity of the dyes constituting each color is measured before the color filter is manufactured, and the colors having the dyes having the higher affinity are sequentially formed, the fluctuation of the transmission spectral characteristics during the manufacturing process can be prevented.

It should be noted that the present invention is not limited to the above-described embodiment, and the same effect can be obtained even when anti-staining is performed by forming a protective film. That is, moisture and a part of the dye molecules also pass through the protective film, so that a difference in affinity between the dye substrate and the dye causes desorption of the dye previously dyed, resulting in color mixing.

[Action]

According to the present invention, in order to preferentially form a pixel having a dye having a large affinity for a dye substrate, the desorption of the dye from the previously dyed pixel is prevented, and in the subsequent step, another dye is adsorbed. Can be prevented.

〔Example〕

A glass substrate having a thickness of 0.5 mm is washed, a photosensitive solution composed of casein-ammonium dichromate is applied to a thickness of 0.8 μm, dried in an oven at 70 ° C., and passed through a photomask having a predetermined pattern. It was adhered, exposed, developed in water at 40 ° C, and cured in an oven at 150 ° C. Then
It was immersed in a cyan dyeing bath having the composition shown in the attached table for 10 minutes for dyeing, immersed in a 1% tannic acid aqueous solution, and subjected to hardening treatment. Similarly, the photomask was accurately positioned at a predetermined position with respect to the cyan pixel, thereby forming an ero pixel.
Finally, as a protective film, a thermosetting transparent resin JSS-18 (manufactured by Japan Synthetic Rubber) was applied to a thickness of 1 μm and cured in an oven at 180 ° C. to obtain a desired color filter.

 The dye bath composition for each color is as shown in the following table.

When the color filter obtained in this manner was attached to a solid-state imaging device and photographed, good color reproducibility was obtained.

〔The invention's effect〕

As described above, according to the present invention, in the coloring step of forming the colored pixels constituting the color filter, color mixing can be prevented, so that the transmission spectral characteristics of the color filter can be maintained and good color can be maintained. Reproducibility can be obtained. In addition, the quality as a color filter is improved, and the reliability is greatly improved.

[Brief description of the drawings]

FIG. 1 shows transmission spectral characteristics showing that color mixing differs according to the color order according to the present invention. FIG. 1 (A) shows dyeing of Solway Blue R first, and after dye-proofing, a Metanil Yellow YK dye bath. (B) shows a case where Metanil Yellow YK was first dyed, and after immersion prevention, was immersed in a Solway Blue R dye bath, and FIGS. 2 (A) to 2 (E) show conventional methods. It is sectional drawing which shows the manufacturing method of a color filter. 1 ... substrate, 2 ... relay image, 3, 4, 5 ... colored pixel, 6 ... protective film.

Claims (1)

(57) [Claims] 1. A method of manufacturing a color filter, wherein a colored pixel portion is formed by dyeing a dye substrate portion provided on a substrate with a dye, wherein the formation of the colored pixel is performed by measuring the affinity between the dye substrate and each dye. A method for producing a color filter, wherein the steps are performed in the order of size.