JP2799629B2 - Manufacturing method of color filter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a color filter, and more particularly to a developing method for forming a color filter for a color display using a colored resin.

[Prior art] Conventionally, as a color filter, a mordant layer made of a hydrophilic polymer substance such as gelatin, casein, glue or polyvinyl alcohol is provided on a substrate, and the mordant layer is dyed with a dye to form a colored layer. Staining color filters are known.

In such a dyeing method, there are many usable dyes and it is relatively easy to cope with the spectral characteristics required as a color filter.However, in the dyeing process of the mordant layer, the mordant layer is dissolved in a dye bath in which the dye is dissolved. This method has a drawback that the yield is poor because a wet process which is difficult to control such as immersion is used, and a complicated process of providing an intermediate layer for resist printing for each color is involved. In addition, the heat resistance of the dye that can be dyed is relatively low at about 150 ° C. or less, and when the filter requires thermal treatment, it is difficult to use, and the heat resistance and light resistance of the dyed film itself are difficult. Also has the drawback of poor reliability.

On the other hand, conventionally, a color filter using a coloring resin in which a certain coloring material is dispersed in a transparent resin is known.

For example, JP-A-58-46325, JP-A-60-78401, JP-A-60-184202, JP-A-60-184203, JP-A-60-184204, and JP-A-60-184204 According to a color filter characterized by using a colored resin film in which a coloring material is mixed with a polyamino resin, the polyamino resin itself has heat resistance and light resistance as shown in JP-A-60-184205. Although it is excellent in properties such as properties, the pattern formation of the color filter because it is a non-photosensitive resin, a method by printing that is disadvantageous to the fine pattern, or after providing a resist mask on the colored resin film, The complicated process of the manufacturing process of etching the colored resin film had to be taken.

On the other hand, as shown in JP-A-57-16407, JP-A-57-74707, JP-A-60-129707, etc., a colored resin film obtained by mixing a coloring material with a photosensitive resin is used. According to the color filter characterized in that it is used, a fine pattern can be formed only by a general photolithography process depending on the method of manufacturing the color filter, and the process can be simplified.

However, when a color filter is formed using a coloring resin obtained by mixing a coloring material with such a photosensitive resin, the coloring material itself generally absorbs light in an exposure wavelength range, and thus is necessary for photo-curing of the photosensitive resin. Exposure energy will be much larger than usual.

In general, the light intensity at the time of exposure to a photosensitive resin decreases exponentially as it enters the depth direction from the light irradiation surface. Therefore, the attenuation of the incident light intensity at the time of exposure from the light irradiation surface to the depth direction due to the incorporation of a coloring material having a light absorbing property into the photosensitive resin is significantly increased,
In some cases, photocuring near the interface with the substrate at the bottom of the photosensitive colored resin film became insufficient, and film peeling occurred during development.

Further, if the exposure energy is made extremely large in order to compensate for the attenuation of the incident light intensity at the time of exposure, the coloring material itself may be deteriorated.

Furthermore, the coloring resin film surface is mixed with the coloring material,
In addition to causing surface roughness and scattering on the color filter surface, lowering the optical performance of the color filter,
When the liquid crystal display element is formed on the inner surface, the orientation of liquid crystal molecules may be disturbed.

As described above, when a color filter is formed using a colored resin in which a coloring material is mixed with a photosensitive resin, problems remain in the stability, durability, and performance of the color filter film in the process. I was

In order to solve the above-mentioned drawbacks, the present applicant has already filed a Japanese Patent Application No. 62-22461 (Japanese Patent Application Laid-Open No. 63-191104), which enables efficient pattern formation with less exposure energy, A color filter having a colored resin film having a smoother surface condition, which prevents deterioration of the colored material itself, reduces variations in photocuring in the depth direction of the film. This color filter uses a colored resin obtained by dispersing at least a coloring material in a photosensitive resin, and in a color filter having a plurality of patterned colored resin layers formed by repeating a photolithography process, the coloring material is used as a colored resin. The layer is gradually dispersed from the surface to the bottom of the layer.

[Problems to be Solved by the Invention] In order to form the above color filter on a substrate, patterning is performed by a photolithography process using a coloring material in which at least a coloring material is dispersed in a photosensitive resin. As a method, a colored resin is applied to a substrate using a method such as a spinner method, a printing method, a roll coater method, and then temporarily cured (prebaked) using an oven or the like, and then exposed through a photomask and immersed in a developer. And developed to form a color filter pattern.

However, in the photolithography process, when exposing the colored resin applied on the substrate to light, there is no deterioration of the colored material itself or surface roughness, and proper exposure that can sufficiently perform photocuring also in the depth direction of the colored resin film. After exposure with energy, even when developing with a developer, room temperature (21 to
Only immersion in a developing solution at a temperature of about 22 ° C.) slows down the chemical dissolution rate of the unexposed portion and requires a considerably longer immersion time.

Also, especially near the interface with the substrate, a coupling agent may be contained in the colored resin in order to improve the adhesion between the colored resin of the photocured portion and the substrate. Even if the immersion time in the developing solution is increased until the surface becomes rough, the colored resin in which the colored material in the unexposed portion is dispersed cannot be completely removed, and remains as a residue at the interface with the substrate. There was a disadvantage.

The present invention has been made in order to improve such disadvantages of the prior art, and completely removes the residue of the colored resin in the unexposed portion at a high developing speed during wet development with a developer in a photolithographic process. It is another 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, according to the present invention, a colored resin obtained by dispersing at least a colored material in a photosensitive resin is applied on a substrate, heated and temporarily cured, and then patterned by a photolithography process. In the method of forming a color filter, a frequency of 0.8 to 1.5 MHz during wet development with a developer in a photolithographic process.
A method for producing a color filter, characterized by spraying a developing solution obtained by synergizing the ultrasonic vibration of the above with a colored resin on a substrate for development.

In the color filter manufacturing method of the present invention, during wet development with a developer in the photolithography step, development is performed by irradiating ultrasonic vibration, the frequency of the ultrasonic vibration is usually 20 kHz to 1.5 kHz, preferably 26 kHz to 1.1 kHz. The range of MHz is desirable, and by irradiating ultrasonic vibration of 20 KHz to 1.5 MHz, a physical force is added to the developer, and the removal speed of the colored resin in the unexposed portion is further increased, and furthermore, the Unexposed portions of the colored resin residue can be completely removed up to the interface.

Further, in the present invention, it is preferable to heat the developing solution to 25 to 30 ° C. during wet development with the developing solution when patterning the color filter by the photolithography process, and by heating, the unexposed portion of the colored resin is heated. Dissolution is promoted and the removal speed is increased.

Further, as a method of irradiating the ultrasonic vibration, it is preferable that at least two or more ultrasonic vibrations having different frequencies are simultaneously irradiated perpendicularly to the substrate for development.

As another method of irradiating the ultrasonic vibration, a developing solution in which ultrasonic vibration having a frequency of 0.8 to 1.5 MHz is synergistically sprayed onto the colored resin on the substrate to perform development.

[Example] Hereinafter, the present invention will be described more specifically with reference to examples.

Reference Example 1 FIG. 1 is an explanatory view showing one reference example of a method for manufacturing a color filter of the present invention, and shows an outline of a developing step in patterning a color filter.

In the figure, 1 is a glass substrate having a thickness of 1.1 mm,
A colored resin (PA-1002R, PA-1002G, PA-1002B, manufactured by Ube Industries, Ltd.) 2 formed by dispersing a coloring material in a photosensitive resin is formed on one surface thereof. The colored resin film is formed by applying a colored resin 2 on a glass substrate 1 by a flexographic printing method, a spinner method, a roll coater method, or the like, and then temporarily curing (pre-baking) using a hot plate oven or the like to form a film having a thickness of 1.6. It was formed uniformly over the entire surface to ± 0.1 μm. Then, using a photomask, UV light having a peak at a wavelength of 365 mm
Exposure was performed at an energy of about 800 mJ to form a light-cured portion and a non-light-cured portion (unexposed portion). Reference numeral 3 denotes a developer (PA-AD Ube Industries, Ltd.) for dissolving the unexposed portions of the colored resin that have not been photocured (unexposed portions), and 4 denotes a developer tank thereof. Reference numeral 5 denotes a constant temperature bath for heating the developer 3 and controlling the temperature.

Reference numerals 6 and 6a denote respective ultrasonic vibrators for irradiating ultrasonic vibrations of 26 KHz and 40 KHz, and reference numeral 7 denotes an oscillator thereof.

The method for manufacturing a color filter according to the present embodiment is based on the above-described apparatus. First, the colored resin 2 is heated to 25 to 30 ° C. in the thermostat 5 and irradiated with UV light to the controlled developer 3. When the glass substrate 1 formed on one side is immersed for about 60 to 300 seconds, the unexposed portion of the colored resin 2 considerably dissolves, but is completely removed up to the interface with the glass substrate 1. I didn't.

Next, while being immersed in the developing solution 3, ultrasonic vibrations of two frequencies of 26 KHz and 40 KHz are respectively applied from the ultrasonic vibrators 6 and 6 a via the developing solution 3 to the glass substrate 1 on which the colored resin 2 is formed. Is irradiated for about 30 seconds to 120 seconds, the cavitation generated in the developer 3 causes the colored resin 2
The unexposed portion was completely and completely removed up to the interface with the glass substrate 1 without unevenness. At this time, in the portion of the colored resin 2 which has been photocured, a predetermined pattern remained without any surface roughness. After that, rinsing, washing, and drying were performed, so that a clean color filter could be formed.

Example 1 FIG. 2 is an explanatory view showing an example of a method for manufacturing a color filter of the present invention, and FIG. 3 is an explanatory view showing a side view of FIG. FIG. 2 shows an outline of a developing step at the time of color filter patterning as in the first embodiment.

In the same figure, reference numeral 1 denotes a glass substrate, on the upper surface of which a colored resin (PA-1002R, PA-1002G,
PA-1012B, manufactured by Ube Industries, Ltd.) 2. 3 is a developer (PA-AD Ube Industries), 8 is a developer 3
And 9 is a nozzle for spraying the developer 3. Reference numeral 6 denotes an ultrasonic vibrator for irradiating ultrasonic vibrations of 0.8 to 1.5 MHz, reference numeral 7 denotes an oscillator thereof, and reference numeral 10 denotes a horn for converging the generated ultrasonic vibrations.

In the same figure, first, as in Reference Example 1, the glass substrate 1 on which one side of the colored resin
The unexposed portion of the colored resin 2 was dissolved to some extent by being immersed in the developing solution 3 heated to -30 ° C for 1 to 2 minutes.

Next, as shown in FIG. 2, the developing solution 3 is supplied by a pump 8, an ultrasonic wave of 0.8 to 1.5 MHz is generated from the ultrasonic vibrator 6, and the ultrasonic vibration is synergized.
The developer 3 having the ultrasonic vibration focused by 10 is sprayed from the nozzle 9 directly onto the colored resin 2 on the glass substrate 1 from a distance of about 10 to 15 mm for about 1 minute.
The unexposed portion of the colored resin 2 was completely removed up to the interface with the glass substrate 1 by the pressure due to the strong acceleration spread inside. At this time, in the portion of the colored resin 2 where the photo-curing was performed, a predetermined pattern remained without any surface roughness. Thereafter, rinsing, washing and drying were performed, whereby a clean color filter was formed.

[Effects of the Invention] As described above, according to the present invention, a colored resin obtained by dispersing at least a colored material in a photosensitive resin is applied on a substrate, temporarily cured by heating, and exposed, By spraying a developing solution in which ultrasonic vibration having a frequency of 0.8 to 1.5 MHz is synergistically applied to the colored resin on the substrate during wet development with the developing solution, development speed is increased, and production efficiency is improved. Further, since the residue of the colored resin in the unexposed portion can be completely removed, there is an effect that the display quality and the like when used for a display are improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a reference example of a method for manufacturing a color filter of the present invention, FIG. 2 is an explanatory view showing an embodiment of a method for manufacturing a color filter of the present invention, and FIG. 3 is a side view of FIG. FIG. DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Coloring resin 3 ... Developer, 4 ... Developer tank 5 ... Constant temperature bath, 6 ... Ultrasonic vibrator 7 ... Ultrasonic oscillator, 8 ... Pump 9 ... Nozzle, 10 ... ultrasonic horn

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-124002 (JP, A) JP-A-2-176602 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02B 5/20

Claims (1)

(57) [Claims] 1. A method for forming a color filter by applying a colored resin obtained by dispersing at least a colored material in a photosensitive resin onto a substrate, heating and temporarily curing the resin, and then performing patterning by a photolithography process to form a color filter. A method for producing a color filter, comprising spraying a developing solution obtained by synergizing ultrasonic vibrations having a frequency of 0.8 to 1.5 MHz on a colored resin on a substrate during wet development with a developing solution in a step, for development.