JPH11337266A - Oven for manufacturing color filter and manufacture of color filter using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of yields and lowering of throughput caused by the deposit of sublimated matters even when a large amount of color filter substrates are subjected to curing treatment, by providing a mechanism for heating the side of a cover which faces heating plates and/or cooling plates. SOLUTION: A ceramic heater 17 of which temperature is controlled is located at a cover 13 above cooling plates 7, 8 in order to heat the side of the cover 13, which is in face to face with heating plates and/or the cooling plates. A color filter substrate 18 is firstly conveyed to a heating plate 1, and after being heated for a given period of time, conveyed to a heating plate 2 by means of a conveying arm for further heating. The color filter substrate 18 is heated to a given temperature during the course of successive conveys from the heating plate 1 to a cooling plate 12, and finally cooled down to the room temperature. Thus, sublimated matters are prevented from being deposited on the inside of an oven in the in a state where a large amount of color filter substrates are subjected to curing treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter manufacturing oven suitable for a process for manufacturing a color filter for a color liquid crystal display.

[0002]

2. Description of the Related Art In recent years, notebook personal computers equipped with a color liquid crystal display (hereinafter, referred to as a color LCD) have been remarkably popularized. In particular, those equipped with a TFT type color LCD having excellent display quality such as moving images are widely used. It is becoming. The color LCD has a color filter as a key component for displaying a color.

A color filter is formed by forming a red, green, and blue (hereinafter, referred to as R, G, and B) colored layers in a predetermined pattern in a lattice pattern called a black matrix provided on a glass substrate. The production methods include an electrodeposition method, a dyeing method, a printing method and a pigment dispersion method. Of these, the pigment dispersion method has recently become mainstream. In the pigment dispersion method, a color resist or color paste in which a pigment is dispersed in an acrylic photosensitive resin or a polyimide non-photosensitive resin is applied to a glass substrate, dried, and then a positive or negative resist is used. R by photolithography
G and B colored layers are formed. Further, an overcoat layer is formed thereon if necessary. Further, a transparent electrode layer is formed thereon to form a color filter.

In the production of a color filter by a pigment dispersion method, there is a step of heating a color filter substrate to cure a coloring layer, an overcoat layer, and the like.

[0005] An oven is used for this curing step, and examples of such an oven include a hot air circulation system, an infrared irradiation system, and a heating plate system. Among these, the heating plate method is widely used because it is the method that achieves the best balance in terms of equipment cost, running cost, cleanliness, and the like. Oven by this method,
It consists of a heating plate that heats the color filter substrate from room temperature to a temperature at which the color filter coloring layer is cured, and a cooling plate that cools the color filter substrate to room temperature. The processing is performed while sequentially transporting the cooling plates in the order of the cooling plates.

[0006]

However, when the color filter substrate is heated by such a conventional heating plate type oven to cure the layer, there are the following problems.

[0007] R, G, or B pigments used in the coloring layer of the color filter by the pigment dispersion method, of which, for example, the R pigment has the property of sublimating at about 250 ° C or higher. On the other hand, the curing temperature of the color filter coloring layer is 160 to 300 ° C. for the acrylic resin and 180 to 350 ° C. for the polyimide resin, so that when the coloring layer is cured in the heating plate type oven, the pigment undergoes sublimation. Will wake up. When the sublimated gas is exposed to a low-temperature portion inside the oven, recrystallization occurs, and the gas re-adheres as a sublimate. When a large number of substrates are processed in the production of color filters, the sublimates accumulate and accumulate in the apparatus, and eventually fall and adhere to the color filter substrates. When the sublimate adheres to the color filter substrate, when its height is about 5 μm or more, it causes a problem on the display of the color LCD, so that the yield is deteriorated as a defective color filter. As a countermeasure, if the sublimate deposited in the oven is cleaned, the defect can be reduced, but on the other hand, a serious problem of lowering the operation rate, that is, the throughput, is caused.

[0008] A similar problem occurs when the overcoat layer is cured. In particular, in the case of a polyimide-based overcoat layer, the oligomer in the overcoat agent sublimates and deposits in the oven, causing a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art. Even if a large amount of a color filter substrate is cured, the yield due to the deposition of sublimates deteriorates,
An object of the present invention is to provide a color filter manufacturing oven and a color filter manufacturing method that do not cause a decrease in throughput.

[0010]

DISCLOSURE OF THE INVENTION The above-mentioned problems in the prior art include one or more heating plates, one or more cooling plates, and a lid for covering the heating plates and the cooling plates. An oven for heating and cooling the color filter substrate by sequentially transporting the color filter substrates onto the cooling plate, wherein a mechanism for heating the side of the lid facing the heating plate and / or the cooling plate is provided. And a method for manufacturing a color filter using the same.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

The color filter manufacturing oven of the present invention has one or more heating plates for heating the color filter substrate and one or more cooling plates for cooling the color filter substrate. By sequentially transporting the color filter substrates onto these plates, the color filter substrates are heated from room temperature to a predetermined temperature, and then the color filter substrates are cooled to room temperature or a temperature close to the room temperature.

The heating plate in the oven for manufacturing a color filter of the present invention raises or maintains the temperature of the color filter substrate from room temperature to a predetermined temperature. The number of heating plates may be only one, or two or more. The heating temperature of the color filter substrate, the heating time,
It is appropriately selected according to the heating time, the size of the apparatus, and the like, and is not particularly limited. As the material of the heating plate, any conventionally known material can be adopted. Examples of such materials include metals such as aluminum, iron and copper, alloys such as stainless steel and brass, and porcelain such as ceramics. Of these, aluminum is particularly preferred. Further, the heating plate may be subjected to a ceramic surface treatment, a chrome plating treatment, or the like.

As a method of heating the color filter substrate on the heating plate, a method of directly contacting the substrate with the heating plate, or a method of providing proximity pins for supporting the substrate on the heating plate and providing a fixed space between the substrate and the heating plate. Examples of the method include an interval. When the substrate is brought into direct contact with the heating plate, a method may be employed in which one or more holes having an arbitrary diameter are provided in the heating plate, and air is sucked from the hole, that is, the substrate is brought into close contact with the heating plate by suction.

In the case where the proximity pins are used for the heating plate, the length can be arbitrarily set according to the required uniformity of the substrate temperature and the like.
20 mm is preferred, and more preferably 0.5 to 10 mm
It is. The diameter of the proximity pin can be arbitrarily set according to the size of the substrate, the weight of the substrate, the number of the proximity pins, and the like, but is preferably 0.2 to 10 mm, and more preferably 0.5 to 7 mm. . As the material of the proximity pin, any conventionally known material can be adopted, such as aluminum,
Metals such as iron and copper, alloys such as stainless steel and brass,
Porcelains such as ceramics, and heat-resistant resins such as polyamide and polyimide are exemplified. Among them, stainless steel, ceramic and polyimide are particularly preferred.

For the purpose of making the temperature of the color filter substrate uniform, a soaking plate (reflecting plate) can be provided on the heating plate. The distance between the soaking plate and the color filter substrate heated on the heating plate is preferably 1 to 10
0 mm, more preferably 5 to 50 mm. As the material of the heat equalizing plate, any conventionally known material can be used, such as aluminum,
Metals such as iron and copper, alloys such as stainless steel and brass,
Porcelain such as ceramics may be used. Of these, aluminum and stainless steel are particularly preferred.

The time for heating the color filter substrate with one heating plate can be set arbitrarily according to the throughput, the resin properties of the layer to be heat-treated, and the like.

The cooling plate in the color filter manufacturing oven of the present invention is disposed after the heating plate.
The temperature is set so as not to exceed the temperature setting of the heating plate. The number of cooling plates may be one or more, and is appropriately selected according to a temperature difference between a heating temperature and room temperature, a cooling time to room temperature, a device size, and the like, and is not particularly limited. . As the material of the cooling plate, any conventionally known material can be adopted. Examples of such materials include metals such as aluminum, iron and copper, alloys such as stainless steel and brass, and porcelain such as ceramics. Of these, aluminum is particularly preferred. The surface of the cooling plate may be subjected to a ceramic surface treatment, a chrome plating treatment, or the like.

As a method of cooling the substrate on the cooling plate, a method of directly adhering the substrate to the cooling plate or a method of providing a proximity pin for supporting the substrate on the cooling plate so that a certain distance is provided between the substrate and the cooling plate. And the like. When the substrate is brought into close contact with the cooling plate, a method may be employed in which one or more holes having an arbitrary diameter are provided in the cooling plate, and air is sucked from the hole, that is, the substrate is brought into close contact with the cooling plate by suction.

When a proximity pin is used for the cooling plate, its length can be set arbitrarily according to the required uniformity of the substrate temperature, etc.
20 mm is preferred, and more preferably 0.5 to 10 mm
It is. The diameter of the proximity pin can be arbitrarily set according to the size of the substrate, the weight of the substrate, the number of the proximity pins, and the like, but is preferably 0.2 to 10 mm, and more preferably 0.5 to 7 mm. . As the material of the proximity pin, any conventionally known material can be adopted, such as aluminum,
Metals such as iron and copper, alloys such as stainless steel and brass,
Porcelains such as ceramics, and heat-resistant resins such as polyamide and polyimide are exemplified. Among them, stainless steel, ceramic and polyimide are particularly preferred.

The time for cooling the color filter substrate with one cooling plate can be set arbitrarily according to the throughput, the temperature difference from the heating temperature to room temperature, and the like.

The color filter manufacturing oven of the present invention is characterized in that a mechanism for heating a side of the lid that covers the heating plate and the cooling plate, which faces the heating plate and / or the cooling plate, is provided. Since the portion of the lid covering the heating plate and the cooling plate facing the heating plate and / or the cooling plate is at or below the sublimation temperature of the sublimate, the sublimation gas generated when the heating plate heats the color filter layer is removed. Easy to recrystallize and deposit. As a countermeasure, by providing a mechanism for heating this portion, it is possible to prevent the sublimate from being deposited.

As a heating mechanism, a conventionally known heating mechanism using heat conduction, convection or radiation can be employed. As a heating mechanism by conduction and convection, for example, a heater by Joule heat generated when a conductive material such as a nichrome wire, a tantalum wire, a tungsten wire, or a ceramic is energized, or air, nitrogen, or argon heated in a flow path such as a pipe Gas or a liquid such as silicone oil. In addition, examples of the heating mechanism using radiation include an infrared lamp heater and a far infrared lamp heater. The heating temperature can be arbitrarily set according to the substance to be sublimated and deposited in the oven.
Since the sublimation temperature is about 250 ° C, it is preferably from 250 to 300 ° C, more preferably from 250 to 280 ° C.

In the oven of the present invention, when heating the side of the cover that covers the heating plate and the cooling plate facing the heating plate and / or the cooling plate, the temperature of the side of the lid that faces the heating plate and / or the cooling plate is adjusted. A mechanism that measures the temperature and controls the temperature of the lid within a certain range based on the result can be provided. If the color filter substrate is not heated in the oven, heat from a hot plate or a cooling plate is directly applied to the lid, causing a rise in temperature. On the other hand, when the color filter substrate is continuously heated in the oven, heat is blocked by the substrate, so that a rise in the temperature of the lid is suppressed. This is because a temperature difference occurs in the lid between the case where the color filter substrate is not heated in the oven and the case where the color filter substrate is heated. As a mechanism for controlling the temperature, there is a method of measuring the temperature of the lid with a thermocouple or the like, and appropriately increasing or decreasing the power supplied to the heater based on the measurement result. Alternatively, a method in which a pipe or the like is provided in a lid and a heated gas or liquid is passed through the pipe may be a method of appropriately increasing or decreasing the flow rate or flow rate of the gas or liquid based on the temperature measurement result.

The color filter manufacturing oven of the present invention may be provided with a mechanism for exhausting air between the heating plate and / or the cooling plate and the lid. By providing this mechanism, the sublimation gas generated from the cured layer of the color filter can be discharged, and the sublimate can be prevented from being deposited inside the oven. As an exhaust method, for example, there is a method in which a pipe having an intake port is provided in an oven, and air is sucked from the intake port.
At this time, the amount of exhaust can be appropriately adjusted by the distance between the heating plate and the lid, the heating temperature, and the like. Therefore, it is preferable to provide a damper in the pipe so that the displacement can be adjusted. Further, since the sublimation gas rises by convection, it is preferable to exhaust the gas from above the heating plate or the cooling plate.

The color filter manufacturing oven of the present invention is preferably employed for manufacturing a color filter made of a non-photosensitive polyimide resin. Although the polyimide resin varies depending on its composition, it is necessary to set the temperature to a relatively high temperature of 250 to 350 ° C. to cure the resin, and the sublimate is easily deposited in the oven.

The production of a color filter using the oven for producing a color filter of the present invention can employ any known method. As an example, first, a black paste in which carbon black is dispersed in a mixture of a polyimide precursor and an organic solvent is applied to a glass substrate,
Heat to 50-180 ° C in an oven to perform semi-cure. Next, a positive photoresist is applied and prebaked by heating to 40 to 150 ° C. in an oven. Thereafter, the black matrix pattern is exposed by irradiating ultraviolet rays, and subsequently, the photoresist and the black paste film are etched with an alkali developing solution. After etching, the remaining photoresist film is peeled off with an organic solvent,
A black matrix layer is formed. Thereafter, by heating the substrate in the oven of the present invention, the polyimide precursor of the black matrix layer is converted into polyimide and cured. The above steps are similarly performed for R, G and B,
R, G and B colored layers are formed on the black matrix layer. Further, an overcoat material is applied thereon if necessary, and semi-cured and cured to form an overcoat layer. Next, a transparent electrode is provided on this, and a color filter is obtained.

The above-mentioned black matrix layer can be formed of a single layer of a metal such as chromium or an oxide or nitride thereof or a multilayer film of two or more layers.
The color filter production oven of the present invention is not only preferably used in any of the above-described color filter colored layer curing steps, but also appropriately changing the temperature settings of the heating plate, the cooling plate, and the lid heater. If used for semi-cure, pre-bake, etc., solvent condensation in the apparatus can be prevented.

[0029]

The present invention will be described below in detail with reference to examples.

FIG. 1 is a schematic side view showing an example of an oven for producing a color filter according to the present invention. This oven comprises heating plates 1 to 6, and cooling plates 7 to 12, and a lid 13 covering these. Heating plate 1
The heat equalizing plate 14 is installed on the components # 6 to # 6. The exhaust pipe 1 on the heating plates 1 to 6 and the cooling plates 7 to 12
The air in the oven is exhausted from an exhaust port 16 provided in 5. A ceramic heater 17 whose temperature is controlled is installed on the lid 13 on the cooling plates 7 and 8, and heats the side of the lid 13 facing the heating plate and / or the cooling plate.

The color filter substrate 18 is first loaded on the heating plate 1 and heated. After the color filter substrate is heated on the heating plate 1 for a certain period of time, it is transported onto the heating plate 2 by a transport arm (not shown) and heated. While being sequentially transferred from the heating plate 1 to the cooling plate 12, the color filter substrate is heated to a predetermined temperature and finally cooled to room temperature. Table 1 shows the temperature settings of the ceramic heaters installed on each hot plate, cooling plate, and lid.

[0032]

[Table 1] Example 1 Width (W) 360 x length (L) 465 x thickness (T) 0.7
A black matrix layer made of a non-photosensitive polyimide resin in which carbon black was dispersed was formed on a non-alkali glass substrate having a size of mm (OA-2, manufactured by NEC Corporation) by a photolithography method. Further, a paste made of a polyimide resin in which an anthraquinone R pigment was dispersed was applied to the substrate, and then semi-cured. Thereafter, a positive resist was applied to the substrate, exposed and developed and etched, and the remaining resist was peeled off with an organic solvent to form an uncured R colored layer on the black matrix layer. 2,000 sheets of the color filter substrates thus obtained were continuously put into the oven of the present invention set at the temperature shown in Table 1 at a takt time of 45 seconds to cure the R colored layer. When the inside of the oven was observed after the above heat treatment, no R pigment sublimate was deposited.

Further, a G color layer and a B color layer were formed on the color filter substrate on which the R color layer was formed in the same process as the R color layer. A polyimide-based overcoat agent was applied thereon, and semi-cured in an oven. Table 1
2,000 sheets were continuously charged into the oven of the present invention at a temperature set at 45 ° C. with a tact of 45 seconds to cure the overcoat layer. When the inside of the oven was observed after this heat treatment, no deposition of the overcoat agent sublimate was observed at all.
Thereafter, a transparent electrode layer was formed by sputtering to produce a color filter. This color filter 2000
When the appearance inspection was performed on the sheets, the number of defectives due to the adhesion of the R pigment sublimate or the overcoat agent sublimate was zero.

Comparative Example 1 A continuous 2000 color filters were manufactured in the same manner as in Example 1 except that heating was not performed by a ceramic heater provided on a lid. As a result, a large amount of the R pigment sublimate was deposited in the heating oven for the R colored layer, and a large amount of the sublimate for the overcoat agent was deposited in the lid on the cooling plates 7 and 8 in the heating oven for the overcoat layer. . Further, as a result of the color filter appearance inspection, the number of defects due to the attachment of the R pigment sublimate or the overcoat agent sublimate was 253 out of 2000 sheets.

Example 2 A continuous 2,000 color filter was manufactured in the same manner as in Example 1 except that air was not exhausted from the exhaust pipe. As a result, the R pigment sublimate was slightly deposited in the heating oven of the R colored layer, and the overcoat agent sublimate was slightly deposited in the lid of the cooling plates 7 and 8 in the heating oven of the overcoat layer. . In addition, as a result of the appearance inspection of the color filter, the number of defects due to the adhesion of the R pigment sublimate or the overcoat agent sublimate was 11 out of 2000 sheets.

Comparative Example 2 A continuous 2000 color filter was manufactured in the same manner as in Example 1 except that heating was not performed by a ceramic heater provided on a lid, and air on a heating plate and a cooling plate was not exhausted. . As a result, a large amount of the R pigment sublimate was deposited in the heating oven of the R colored layer, and a large amount of the sublimate of the overcoat agent was deposited in the lid of the cooling plates 7 and 8 in the heating oven of the overcoat layer. . Further, as a result of the color filter appearance inspection, the number of defects due to the attachment of the R pigment sublimate or the overcoat sublimate was 2000
The number was 381 of the sheets.

[0037]

According to the color filter manufacturing oven of the present invention, it is possible to prevent the sublimate from being deposited in the oven when a large amount of the color filter substrate is cured.
It is possible to achieve an improvement in yield and an increase in the operation rate of color filter production.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an example of an oven for producing a color filter of the present invention.

[Explanation of symbols]

 1 to 6: heating plate 7 to 12: cooling plate 13: lid 14: soaking plate 15: exhaust pipe 16: exhaust port 17: ceramic heater 18: color filter substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuya Oku 1-1-1 Sonoyama, Otsu-shi, Shiga Prefecture Toray Industries, Inc. Shiga Plant (72) Inventor Hiroshi Ishigami 1-1-1 Sonoyama, Otsu-shi, Shiga Prefecture Toray Industries, Inc. Shiga Plant

Claims (5)

[Claims] An apparatus comprising: at least one heating plate; at least one cooling plate; and a cover for covering the heating plate and the cooling plate, and sequentially transporting a color filter substrate onto the heating plate and the cooling plate. A color filter manufacturing oven for heating and cooling a color filter substrate according to claim 1, further comprising a mechanism for heating a side of the lid facing the heating plate and / or the cooling plate. 2. A mechanism for measuring the temperature of the side of the lid facing the heating plate and / or the cooling plate, and controlling the temperature of the lid within a certain range based on the result of the measurement. The color filter manufacturing oven according to claim 1. 3. The color filter manufacturing oven according to claim 1, further comprising a mechanism for exhausting air between the heating plate and / or the cooling plate and the lid. 4. The color filter according to claim 1, wherein the color filter is formed of a non-photosensitive polyimide resin.
4. The oven for producing a color filter according to any one of 3. 5. A method for producing a color filter, comprising producing a color filter using the oven for producing a color filter according to claim 1.