JPH0496002A - Manufacture of color filter - Google Patents

Abstract

PURPOSE:To increase a developing speed and to improve the production efficiency by heating a liquid developer to specific temperature at the time of wet development using the liquid developer after temporary setting is carried out by heating, and causing ultrasonic vibration of specific frequency. CONSTITUTION:At the time of the wet development using the liquid developer in a photolithographic process, the ultrasonic vibration is caused to perform development; and the frequency of the ultrasonic vibration is set normally to 20kHz - 1.5MHz. Consequently, the liquid developer is applied with a physical force, the removing speed for the coloring resin at an unexposed part is increased, and the residue of the coloring resin at the unexposed part can be removed completely up to the border surface of a substrate. In this invention, the liquid developer is held preferably at 25 - 30 deg.C in the wet development using the liquid developer for patterning in the photolithographic process of the color filter, and the warming accelerates the dissolution of the coloring resin at the unexposed part to increase the removing speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a color filter, and more particularly to a developing method for forming a color filter for a color display using a colored resin.

[Conventional technology] Conventionally, color filters have been prepared using gelatin, gelatin, etc. on a substrate.
A dyed color filter is known in which a mordant layer made of a hydrophilic polymer material such as casein, gris, or polyvinyl alcohol is provided, and the mordant layer is dyed with a dye to form a colored layer.

With this type of dyeing method, many dyes can be used, and it is relatively easy to meet the spectral characteristics required for color filters. It uses a wet method of dipping, which is difficult to control, and also has the disadvantage of poor yields because it involves a complicated process of providing an interlayer for resist dyeing for each color. In addition, the heat resistance of dyeable dyes is relatively low at about 150°C or less (it is difficult to use if the filter requires thermal treatment, and the dye film itself has poor heat resistance and light resistance. It also has the disadvantage of poor reliability.

On the other hand, color filters using a colored resin in which a certain type of colored material is dispersed in a transparent resin are conventionally known.

For example, JP-A-58-46325, JP-A-60-
Publication No. 78401, Japanese Patent Application Laid-open No. 184202/1983,
JP-A-60-184203, JP-A-60-184
As disclosed in JP-A No. 204, JP-A-60-184205, etc., a color filter is characterized in that it uses a colored resin film in which a coloring material is mixed with a polyamino resin. The resin itself has excellent properties such as heat resistance and light resistance, but since it is a non-photosensitive resin, pattern formation for color filters requires printing methods, which are disadvantageous for fine patterns, or resist printing on colored resin films. It was necessary to use a complicated manufacturing process in which the colored resin film was etched after a mask was provided.

On the other hand, JP-A-57-16407, JP-A-57-7
As disclosed in Japanese Patent Application Laid-Open No. 4707, Japanese Patent Application Laid-Open No. 60-129707, etc., a color filter characterized by using a colored resin film made of a photosensitive resin mixed with a coloring material is disclosed. Depending on the method, fine patterns can be formed using only a general photolithography process, making it possible to simplify the process.

However, when forming a color filter using a colored resin such as a photosensitive resin mixed with a coloring material, the coloring material itself generally absorbs light in the exposure wavelength range.
The exposure energy required for photocuring the photosensitive resin is considerably larger than usual.

Generally, the light intensity when exposing a photosensitive resin to light enters in the depth direction from the light irradiation surface (accordingly, it decreases exponentially). The attenuation of the intensity of the incident light during exposure in the depth direction from the light irradiation surface due to the contamination of the resin becomes significantly large, and in some cases, photocuring near the interface with the substrate, which is the bottom of the photosensitive colored resin film, becomes insufficient. Film peeling etc. may occur during development.

Furthermore, if the exposure energy is made very large in order to compensate for the attenuation of the intensity of the incident light during exposure, the coloring material itself may deteriorate.

Furthermore, the surface of the colored resin film becomes rough due to the mixing of coloring materials, which causes scattering on the surface of the color filter, degrading the optical performance of the color filter. The alignment of liquid crystal molecules could also be disturbed.

In this way, when forming a color filter using a colored resin that is a mixture of a photosensitive resin and a coloring material, there remain problems in the stability and durability of the color filter film in the process, and in terms of performance as a color filter. It had been.

In order to eliminate the above-mentioned drawbacks, the present applicant has already filed Japanese Patent Application No. 62-22461 (Japanese Unexamined Patent Publication No. 63-191104). It prevents the deterioration of the coloring material itself, reduces the variation in photocuring in the depth direction of the film,
We also proposed a color filter that has a colored resin film with a smoother surface.

This color filter uses a colored resin made by dispersing a small amount of a colored material in a photosensitive resin, and has a plurality of patterned colored resin layers formed by repeating a photolithography process. The colored resin layer is gradually dispersed from the surface to the bottom.

[Problems to be Solved by the Invention] In order to form the above-mentioned color filter on a substrate, patterning is performed by a photolithography process using a coloring material in which a small amount of coloring material is dispersed in a photosensitive resin. In the coating process, colored resin is applied onto the substrate using means such as a spinner method, printing method, or roll coater method, and is then temporarily cured (prebaked) using an oven or the like, and then exposed through a photomask and developed. It is immersed in a liquid and developed to form a color filter pattern.

However, in the photolithography process, when exposing colored resin coated on a substrate, proper exposure is required to ensure sufficient photocuring in the depth direction of the colored resin film without deterioration of the colored material itself or surface roughness. After being exposed to energy,
Even when developing with a developer, the temperature at room temperature (21 to 2
If the film is simply immersed in a developing solution at a temperature of about 2° C., the chemical dissolution rate of the unexposed area is slow, and the immersion time must be considerably long.

In addition, in order to improve the adhesion between the colored resin in the photo-cured part and the substrate, especially near the interface with the substrate, the colored resin may contain a coupling agent, so Even if the immersion time in the developer is prolonged until the surface becomes rough, the colored resin that disperses the colored material in the unexposed areas cannot be completely removed and remains as a residue at the interface with the substrate. There was a drawback that it could be stored away.

The present invention was made in order to improve the drawbacks of the conventional technology, and is capable of completely removing colored resin residues in unexposed areas at a high development speed during wet development using a developer in the photolithography process. It is an object of the present invention to provide a method for manufacturing a color filter with improved production efficiency.

[Means for Solving the Problems] That is, the present invention involves coating a substrate with a colored resin obtained by dispersing at least a coloring material in a photosensitive resin, heating and temporarily curing the resin, and then patterning it by a photolithography process. In the method of forming a color filter using a photolithography process, a frequency of 20 KHz is
This is a method for manufacturing a color filter, characterized by irradiating ultrasonic vibrations of ~1.5 MHz.

In the method for manufacturing a color filter of the present invention, development is performed by irradiating ultrasonic vibration during wet development using a developer in the photolithography process, and the frequency of the ultrasonic vibration is usually 20 KHz to 1.5 MHz, preferably 26 KHz.
~1.1MHz (7) range is desirable, 20KH
By irradiating ultrasonic vibrations of z~1.5MHz,
Physical force is applied to the developer, and the removal speed of the colored resin in the unexposed area becomes faster (furthermore, it is possible to completely remove the colored resin residue in the unexposed area up to the interface with the substrate). can.

In addition, in the present invention, it is preferable to heat the developer to 25 to 30"C during wet development using a developer when patterning a color filter by a photolithography process. By heating, unexposed areas are colored. Dissolution of the resin is promoted and removal speed is increased.

In addition, as a method of irradiating ultrasonic vibrations, at least two or more ultrasonic vibrations with different frequencies are simultaneously applied.
It is preferable to develop by irradiating perpendicularly to the substrate.

Further, as another method of irradiating ultrasonic vibrations, development can be carried out by spraying a developer containing synergistic ultrasonic vibrations with a frequency of 0.8 to 1.5 MHz onto the colored resin on the substrate.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 FIG. 1 is an explanatory diagram showing an example of the method for manufacturing a color filter of the present invention, and shows an outline of the developing process during color filter patterning.

In the figure, 1 is a glass substrate with a thickness of 1.1 mm, and on one side of the glass substrate is a colored resin (PA-1012R, PA-1012G, PA) made by dispersing a coloring material in a photosensitive resin.
-1012B, manufactured by Ube Industries, Ltd.) 2 is formed. The colored resin film can be formed using a flexographic printing method, a spinner method,
Colored resin 2 is coated on glass substrate 1 by roll coater method etc.
After coating, temporary curing (prebaking) was performed using a hot plate oven or the like to uniformly form a film with a thickness of 1.6±0.1 gm over the entire surface. Next, using a photomask, UV light with a peak wavelength of 365 mm was used to remove 400 to 800 mm.
Exposure was performed with an energy of mJ to form a photocured portion and a non-photocured portion (unexposed portion).

3 is the unexposed part of the colored resin that has not been photocured (
A developing solution (manufactured by PA-AD Ube Industries, Ltd.) is used to dissolve the unexposed area (unexposed area), and 4 is a developing solution tank. 5 is a constant temperature bath for heating the developer 3 and controlling the temperature.

Moreover, 6 and 6a are respective ultrasonic transducers for irradiating ultrasonic vibrations of 26 KHz and 40 KHz, and 7
are their oscillators.

In the method for manufacturing a color filter of the present invention, in the above-mentioned apparatus, first, a developer 3 heated and controlled at 25 to 30°C in a constant temperature bath 5 is irradiated with UV light, and the colored resin 2 is exposed to light. The glass substrate 1 formed on one side is
When the resin was immersed for 0 to 300 seconds, the unexposed portions of the colored resin 2 were considerably dissolved, but the interface with the glass substrate 1 was not completely removed.

Next, while immersed in the developer 3, the ultrasonic transducers 6 and 6a generate 26 KHz, 40. Ultrasonic vibrations of two frequencies of KHz are applied to the glass substrate 1 on which the colored resin 2 is formed through the developer 3 for approximately 30 sec x 120 sec.
When irradiated for a period of e, due to the action of cavitation generated in the developer 3, the unexposed portions of the colored resin 2 were completely and evenly removed over the entire surface up to the interface with the glass substrate 1. At this time, the photocured portion of the colored resin 2 did not have any roughness on its surface, and a predetermined pattern remained. After rinsing, washing with water, and drying, a beautiful color filter could be formed.

Embodiment 2 FIG. 2 is an explanatory diagram showing another embodiment of the color filter manufacturing method of the present invention, and FIG. 3 is an explanatory diagram showing a side view of FIG. 2. FIG. 2 shows an outline of the development process during color filter patterning, as in the first embodiment.

In the same figure, 1 is a glass substrate, and on its upper surface is a colored resin (PA-1012R,
-1012G, PA-1012B, manufactured by Ube Industries) 2
is formed. Further, 3 is a developer (manufactured by PA-AD Ube Industries, Ltd.), 8 is a pump for supplying the developer 3, and 9 is a nozzle for spraying the developer 3. Further, 6 is an ultrasonic vibrator for irradiating ultrasonic vibrations of 0.8 to 1.5 MHz, 7 is its oscillator, and 1
0 is a horn for focusing the generated ultrasonic vibrations.

In the same figure, first, as in Example 1, a glass substrate l on which a colored resin 2, which has been exposed to light, is formed on one side, is placed at 25
It was immersed for 1 to 2 minutes in the developer 3 heated to ~30''C to dissolve the unexposed portion of the colored resin 2 to some extent.

Next, as shown in FIG. 2, the developer 3 is supplied by the pump 8, and the ultrasonic vibrator 6 generates ultrasonic waves of 0.8 to 1.5 MHz to synergize the ultrasonic vibrations. The developer 3 with ultrasonic vibration focused by the horn 10 is directly applied to the colored resin 2 on the glass substrate 1 from the nozzle 9 by approximately 1
When the spray was applied to the entire surface for about 1 minute from a distance of 0 to 15 mm, the unexposed areas of the colored resin 2 were completely sprayed down to the interface with the glass substrate 1 due to the pressure caused by the strong acceleration that spread in the developer 3. removed. At this time, there was no roughness on the surface of the photo-cured portion of colored resin 2 (predetermined pattern remained.After this, after rinsing, washing with water, and drying, a beautiful color filter was formed. We were able to.

[Effects of the Invention] As explained above, according to the present invention, a colored resin made by dispersing a small amount of a colored material in a photosensitive resin is applied onto a substrate, heated to temporarily harden it, and exposed to light. After that, during wet development with a developer, the developer is heated to 25-30°C and irradiated with ultrasonic vibrations with a frequency of 20 KHz to 1.5 MHz, which increases the development speed (and improves production efficiency). Furthermore, since the residual colored resin in the unexposed areas can be completely removed, the display quality when used in a display is also improved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the color filter manufacturing method of the present invention, FIG. 2 is an explanatory diagram showing another embodiment of the color filter manufacturing method of the present invention, and FIG. FIG. 1... Glass substrate 3... Developer solution 5... Constant temperature bath 7... Ultrasonic oscillator 9... Nozzle 2... Colored resin 4... Developer tank 6... Ultrasonic vibration Child 8...Pump lO...Ultrasonic horn

Claims (4)

[Claims] (1) A colored resin made by dispersing at least a colored material in a photosensitive resin is applied onto a substrate, and after temporary curing by heating,
In a method of forming a color filter by patterning in a photolithography process, a frequency of 20 KHz to 1.5 MHz is used during wet development using a developer in the photolithography process.
A method for manufacturing a color filter, characterized by irradiating it with ultrasonic vibrations. (2) The method for producing a color filter according to claim 1, wherein the color filter is developed using a developer heated to 25 to 30°C. (3) The method for producing a color filter according to claim 1, wherein the substrate is developed by simultaneously irradiating the substrate with ultrasonic vibrations having two or more different frequencies perpendicularly. (4) The method for manufacturing a color filter according to claim 1, wherein the colored resin on the substrate is developed by spraying a developer containing synergistic ultrasonic vibrations with a frequency of 0.8 to 1.5 MHz.