JPH08211626A - Resist coating device - Google Patents

Abstract

PURPOSE: To form a resist film of uniform thickness applied on a glass substrate and to form a coating film of high quality. CONSTITUTION: In this resist coating device, a glass substrate is passed through between a nip roller 3 arid a roll bar in such a manner that the substrate is carried at a specified speed between the rotating roll bar and the nip roller 3 which is on the roll bar and presses the bar while a resist soln. is brought into contact with the lower surface of the substrate to form a resist film of desired thickness. The diameter of the nip roller 3 in the resist coating area W for the glass substrate is changed along the longitudinal direction so that the diameter in the center of the resist coating area W is different form that in the peripheral part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for applying a fluid material to a flat plate, and more particularly to a resist application apparatus for forming a thin layer pattern such as a color filter on a glass substrate for a liquid crystal panel.

[0002]

2. Description of the Related Art A liquid crystal panel which constitutes a color liquid crystal display device is formed by injecting a liquid crystal layer between two transparent glass substrates each having a transparent electrode group formed thereon, and one of the glass substrates serving as the above-mentioned display surface. The basic structure is that a plurality of color filters corresponding to each of a plurality of colors are formed.

In the color filter, a water-soluble photocurable photosensitive composition such as gelatin / dichromate is coated on a glass substrate, which is patterned to correspond to a predetermined pixel pattern, and then a predetermined color is formed. Although a method of forming the dyeing process by repeating the dyeing process to the required number of times has been adopted, it is difficult to efficiently manufacture a stable quality color filter due to problems such as variations in filter concentration and toxicity of the solvent used. In addition, there was a problem that the environment was adversely affected.

In order to solve each of the above problems, a step of applying a photosensitive composition colored with a pigment to a glass substrate, exposing it through a predetermined mask, and developing it to form a predetermined colored pattern is described. A method of repeating the required number of times is known.

The method of applying the pigmented photosensitive composition (hereinafter simply referred to as "resist") to a glass substrate is a roll coating method in which a resist solution is applied by means of a grooved rubber roller, or a resist while rotating the glass substrate. There are various methods such as spin coating method in which the solution is drawn by centrifugal force and applied, but the former has a limit in the smoothness of the coating film, and the latter has a very low utilization rate of the resist solution, which causes many problems. There is a problem that it is difficult to process the glass substrate efficiently.

On the other hand, for example, Japanese Patent Laid-Open No. 2-2580
No. 81, or a rod wound with a wire as disclosed in JP-A-4-270346 (hereinafter,
By using the so-called rod coating method, in which the resist solution is applied from the lower surface of the glass substrate that is conveyed in a plane using a roll bar), a uniform resist coating film can be formed on many glass substrates that are continuously conveyed. Can be formed.

Conventionally, in a pigment resist coating apparatus for a color filter by the rod coating method, a resist solution stored in a resist tray is pumped up by a roll bar arranged therein, and the glass substrate passing above the roll bar is fed from above. The nip roller presses against the roll bar, the resist solution drawn up by the roll bar is brought into contact with the roll bar, and the excess resist solution is scraped off and uniformly applied to the substrate.

In this resist coating apparatus, the roll bar is provided with a roll bar holder for holding the roll bar from the lower surface over substantially the entire length of the nip roller so as not to be bent by the pressure of the nip roller.

FIG. 6 is a schematic diagram for explaining a coating mechanism of a conventional resist coating apparatus using a roll bar. Reference numeral 1 is a glass substrate for coating a resist, 2 is a nip roller for pressing the glass substrate 1 against a nip roller 3, and FIG. 3 is a roll bar for contact-coating the resist solution on the glass substrate 1,
Reference numeral 4 is a resist solution, 4a is a resist solution reservoir made up of the resist solution pumped up by the roll bar 3 and surplus resist scraped off, 4b is a coating film of the applied resist, 5 is a tray, and 6 is a roll bar holding member. Is.

As shown in the drawing, the glass substrate 1 is carried into the facing portion of the roll bar 3 and the nip roller 2 by a substrate transporting device (not shown), and is moved in the direction of arrow A while being pressed against the roll bar 3 by the pressing force of the nip roller 2. .

The resist solution 4 stored in the tray 5 is pumped up by the rotation of the roll bar 3 to form a resist solution reservoir 4a on the loading side of the glass substrate 1. The resist solution reservoir 4a is applied in contact with the glass substrate 1.

When the resist solution is applied to the back surface of the glass substrate 1 and is carried out after passing through the roll bar 3, the roll bar 3 scrapes off the surplus portion of the applied resist solution to obtain a coating of a required thickness. The film 4c is formed.

The thickness of the coating film 4b is determined by various conditions such as the viscosity of the resist solution, the conveying speed of the glass substrate 1, the diameter of the roll bar 3 and the peripheral speed.

Further, the roll bar holding member 6 is fixed to the receiving tray 5 of the resist solution, and the shape of the roll bar rotation receiving portion is also adjusted to the shape of the roll bar to be used (diameter, size and interval of wound wire). Formed, resist switching (color filter color switching,
Etc., or when it is desired to change the film thickness of the resist to be applied, the roll bar 3 and the resist tray 5 are exchanged together for the application.

FIG. 7 is an explanatory diagram of how a conventional resist coating apparatus coats a glass substrate. 1a is a substrate carry-in device, 1b is a carrying roller, 1c is a substrate carry-out device, and 1d.
Is a conveyance roller, and the same reference numerals as those in FIG. 6 correspond to the same portions.

In the figure, first, as shown in (a), the nip roller 2 is positioned in the tray 5, and a gap is formed between the nip roller 2 and the roll bar 3 which is pumping the resist solution 4 by its surface tension while rotating. It rotates while maintaining d. The glass substrate 1 to which the resist is applied is loaded into the gap d with the transport roller 1b of the substrate loading device 1a with the surface thereof facing downward.

As shown in (b), the nip roller 2 has a function of pressing the glass substrate 1 against the roll bar 3 and a function of giving thrust (conveyance force) to the glass substrate 1 by its rotation. It is desirable to use an elastic material such as rubber for the nip roller 2 in order to prevent damage.

Since the thickness of the glass substrate for the liquid crystal panel is usually 0.7 mm or 1.1 mm,
The gap d is set to about 80 to 90% of this glass thickness, and the thrust is applied by elastic deformation of the nip roller.

On the other hand, the nip roller 2 has a cylindrical shape having a length that covers the resist coating area of the glass substrate 1.
An elastic material is provided as an action surface on the outside of the metal core material. This elastic material uses a rubber or the like having solvent resistance in consideration of wiping the attached resist with a solvent such as acetone.

Then, as shown in (c), the resist coated glass substrate or the like is delivered to the substrate unloading device 1c and is unloaded from the nip roller 2.

[0021]

In the above conventional technique, while the glass substrate is being pressed by the roll bar by the nip roller, the resist solution pumped up by the roll bar is applied to the lower surface of the glass substrate so as to be applied thereto.

FIG. 8 is an explanatory view of a state of a resist film applied in a conventional resist applying apparatus, (a) is a schematic view of a resist applied surface of a glass substrate, and (b) is (a).
Sectional view taken along the X ₁ -X ₁ line of, (c) is also X ₂ -
In the cross-sectional view taken along the line X ₂ , in the figure, a circle indicates a portion where the resist film is applied thickly, a triangle indicates a medium film thickness portion, and a cross indicates a thin film thickness portion.

In FIG. 1A, the glass substrate 1 is conveyed on the roll bar 3 in the direction of arrow A while resist 4b.
Is applied.

The thickness of the applied resist 4b is thin at its corners, medium at its edges and thick at its center.

As shown in (b) and (c), there is a difference in the film thickness of the resist applied in the application region of one glass substrate.

That is, the nip roller for applying a pressing force to the glass substrate on the roll bar side is
When it is configured to operate with both ends supported, the pressing force on the glass substrate differs between the both ends and the central part, and the coating conditions such as the viscosity of the resist solution or the contact amount and the scraping amount are different. Also, there is a problem that the film thickness of the resist to be applied becomes uneven because the application conditions are different between the both ends and the central part due to bending of the roll bar holding member holding the roll bar and the like.

Further, the non-uniformity of the film thickness of the resist varies depending on the size of the glass substrate, and even if the glass substrates having different sizes are used, the resist is applied by using a conventional cylindrical roll bar. There is a problem that it is impossible to form a proper resist film.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a resist coating apparatus capable of always forming a uniform resist film.

[0029]

In order to achieve the above object, a first aspect of the present invention is to set a tray for storing a resist solution and at least a part of a peripheral surface thereof into the resist solution. A roll bar which is installed and rotated, a roll bar holding member which is attached to the tray and rotatably holds the roll bar, and a nip roller which presses against the roll bar from above and presses the glass substrate at a predetermined speed. While contacting the resist solution pumped up by the roll bar to the lower surface of the glass substrate while being conveyed by, the resist coating apparatus for forming a resist film of a desired thickness by scraping off the excess resist solution, the nip roller That the longitudinal diameter in contact with the resist coating region on the glass substrate is different between the central portion and the peripheral portion of the resist coating region. And butterflies.

The second aspect of the present invention is characterized in that the diameter of the central portion of the resist coating area of the nip roller is larger than that of the peripheral portion.

Further, the third invention according to claim 3 is
The diameter of the central portion of the resist coating area of the nip roller is smaller than that of the peripheral portion.

The present invention is not limited to the above glass substrate for a liquid crystal panel, but can be applied to an apparatus for applying a resist and a fluid similar thereto to another similar thin plate.

[0033]

In the structure of the first aspect of the invention, the roll bar rotates while the resist stored in the tray is submerged in at least a part of the peripheral surface of the resist solution.

The nip roller applies a pressing force from above to the glass substrate conveyed between the nip roller supported by a roll bar holding member attached to the tray and rotating the roll bar. The nip roller having different longitudinal diameters in contact with the resist coating region on the glass substrate at the central portion and the peripheral portion of the resist coating region gives uniform coating conditions to the glass substrate and forms a uniform resist film. To do.

In the structure of the second aspect of the invention, the diameter of the central portion of the resist application area of the nip roller is made larger than that of the peripheral portion, so that when a resist having a particularly low viscosity is used or the roll bar is bent. A uniform resist film can be formed when the resist is applied in the case of a large value.

Further, in the configuration of the third invention,
By making the diameter of the central portion of the resist coating area of the nip roller smaller than that of the peripheral portion, it is possible to form a uniform resist film when coating a high viscosity resist or using a nip roller for applying a pressing force at both ends support. .

[0037]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic view of a nip roller for explaining the first embodiment of the resist coating apparatus of the present invention.
3 is a nip roller, W is a coating portion corresponding to the resist coating area, D is a diameter difference between the central portion and the end portion of the resist coating area of the nip roller, D ₁ is the diameter of the central portion, and D ₂ is the diameter of the end portion. .

As shown in the figure, the nip roller 3 has a shape in which the diameter gradually increases from both ends to the central portion. The difference D between the central diameter D ₁ and the end diameter D ₂ is
For example, it is formed to have a thickness of 0.02 to 0.15 mm. This size is determined by the size of the glass substrate, the viscosity of the resist solution, the rotation speed of the roll bar, the film thickness to be formed, and other coating conditions.

The resist coating apparatus using this nip roller can always form a uniform resist film.

FIG. 2 is a schematic view of a nip roller for explaining a second embodiment of the resist coating apparatus of the present invention.
3 is a nip roller, W is a coating portion corresponding to the resist coating area, D'is a diameter difference between the center portion and the end portion of the resist coating area of the nip roller, D ₁ 'is the diameter of the central portion, D ₂ ' is the end portion. Is the diameter.

As shown in the figure, the nip roller 3 has a shape in which the diameter gradually increases from both ends to the central portion. The difference D between the 'diameter D ₂ of the end' diameter D ₁ of the central part 'is formed so as for example to 0.02～0.15Mm. This size is determined by the size of the glass substrate, the viscosity of the resist solution, the rotation speed of the roll bar, the film thickness to be formed, and other coating conditions.

According to the resist coating apparatus using this nip roller, it is possible to always form a uniform resist film.

FIG. 3 is a schematic view of a nip roller for explaining a third embodiment of the resist coating apparatus of the present invention.
1 is an example of a nip roller applied to apply a resist for two liquid crystal panels in a direction parallel to the transport direction of a glass substrate.

In the figure, 3 is a nip roller, W ₁ ,
W ₂ is the coating portion corresponding to the resist coating area, D is the diameter difference between the central portion and the end portion of the resist coating area of the nip roller, D ₁ is the diameter of the central portion of each coating area, D ₂ is the nip roller end of the coating area It is the diameter at the part. The diameter D ₃ of the central portion of the nip roller 3 is not limited to be the same as the diameter D ₂ of the end, may be slightly larger or smaller than the diameter D _2.

As shown in the figure, the nip roller 3 has a shape in which the diameter gradually increases from both ends in each application region to each central portion. Diameter D _{1 at} the center of each application area
The difference D between the diameter of the nip roller and the diameter D ₂ at the end of the nip roller is, for example, 0.02 to 0.15 mm. This size is also determined by the size of the glass substrate, the viscosity of the resist solution, the rotation speed of the roll bar, the film thickness to be formed, and other coating conditions, as in the above embodiment.

According to the resist coating device using this nip roller, it is possible to always form a uniform resist film in the coating regions of two parallel sheets.

FIG. 4 is a schematic view of a nip roller for explaining the third embodiment of the resist coating apparatus of the present invention.
Similar to FIG. 3, this is an example of a nip roller applied to apply resist for two liquid crystal panels in a direction parallel to the glass substrate transport direction.

In the figure, 3 is a nip roller, W ₁ ,
W ₂ is the coating portion corresponding to the resist coating area, D is the diameter difference between the central portion and the end portion of the resist coating area of the nip roller, D ₁ is the diameter of the central portion of each coating area, and D ₂ is the end portion of the nip roller. Is the diameter of the application area of.

As shown in the figure, the nip roller 3 has a shape in which the diameter gradually decreases from both ends to the center of each coating area. The difference D ′ between the diameter D ₁ ′ of the central part of the application area and the diameter D ₂ ′ of the end part is, for example, 0.02 to 0.1.
It is formed to have a thickness of 5 mm. This size is also determined by the size of the glass substrate, the viscosity of the resist solution, the rotation speed of the roll bar, the film thickness to be formed, and other coating conditions, as in the above embodiment. The diameter D ₃ ′ of the central portion of the nip roller 3 is not limited to the same as the diameter D ₂ ′ of the end portion of the application area, and may be slightly larger or smaller than the diameter D ₂ ′.

The resist coating apparatus using this nip roller can also always form a uniform resist film in the coating areas of two parallel sheets.

The nip roller shown in FIG. 3 or FIG. 4 is intended to simultaneously apply two resists in parallel with a width of two, and further apply three or more resists in parallel. It can also be configured to be performed at the same time.

FIG. 5 is a schematic front view for explaining the overall structure of the resist coating apparatus of the present invention, in which 1 is a glass substrate and 1 is a glass substrate.
a is a substrate carry-in device, 1b is a carrying roller, 1c is a carry-out device, 1d is a carrying roller, 2 is a nip roller, 3 is a roll bar, 4 is a resist solution, 5 is a receiving tray for the resist solution,
7 is a coating unit, 7a is a rotating device, 7b is a guide rail, 7
Reference numeral c is a lifting device, and 8 is a mount.

In the figure, the glass substrate 1 on which the resist is applied is transported to the coating unit 7 from a substrate supply unit (not shown) by the substrate loading device 1a equipped with the transport roller 1b.

The coating section 7 includes a roll bar 3 and a nip roller 2 which are partially immersed in the resist solution 4 stored in the tray 5 and rotated, and a roll bar 3 which is rotated by a rotating device 7a along a guide rail 7b. The resist solution pumped up by the roll bar 3 is brought into contact with the back surface of the glass substrate 1 carried into the coating section 7 to apply the resist solution, and the excess resist solution is scraped off to obtain a required amount. A resist having a film thickness is applied.

The glass substrate 1 coated with the resist is carried out of the coating section 7 by the rotation of the nip roller 2. This unloading is performed by the substrate unloading device 1c equipped with the transport roller 1d,
It is passed to the drying section (not shown) in the latter stage.

The nip roller 2 is any of those described in FIGS. 1 to 4, and is raised by the elevating device 7c so as to be separated from the roll bar 3 by the elevating device 7c except when the resist is coated on the glass substrate 1. It is removed so that the resist does not adhere.

According to the resist coating apparatus of the present invention, it is possible to provide a resist coating apparatus which can always form a uniform resist film.

[0059]

As described above, according to the present invention,
Forming a high-quality resist film by eliminating the non-uniformity of the resist film thickness and uniformly applying the resist solution using a roll bar including glass substrates of different glass substrate sizes. It is possible to provide a resist coating apparatus capable of performing the above.

[Brief description of drawings]

FIG. 1 is a schematic view of a nip roller for explaining a first embodiment of a resist coating apparatus of the present invention.

FIG. 2 is a schematic view of a nip roller for explaining a second embodiment of the resist coating apparatus of the present invention.

FIG. 3 is a schematic view of a nip roller for explaining a third embodiment of the resist coating apparatus of the present invention.

FIG. 4 is a schematic view of a nip roller for explaining a third embodiment of the resist coating apparatus of the present invention.

FIG. 5 is a schematic front view illustrating the overall configuration of the resist coating apparatus of the present invention.

FIG. 6 is a schematic diagram for explaining a coating mechanism of a conventional resist coating apparatus using a roll bar.

FIG. 7 is an explanatory diagram showing how a conventional resist coating apparatus coats a glass substrate.

FIG. 8 is an explanatory diagram of a state of a resist film applied in a conventional resist applying apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 1a Substrate loading device 1b Conveying roller 1c Unloading device 1d Conveying roller 2 Nip roller 3 Roll bar 4 Resist solution 5 Receptor solution tray 7 Coating unit 7a Rotating device 7b Guide rail 7c Elevating device 8 Stand

Claims (3)

[Claims] 1. A tray for storing a resist solution, a roll bar for rotating at least a part of its peripheral surface immersed in the resist solution, and a roll attached to the tray for rotatably holding the roll bar. While carrying the glass substrate at a predetermined speed between the bar holding member and the nip roller that presses against the roll bar from above, the resist solution pumped up by the roll bar is brought into contact with the lower surface of the glass substrate, and excess In a resist coating apparatus for forming a resist film having a desired thickness by scraping off the resist solution, the longitudinal diameter of the nip roller in contact with the resist coating region on the glass substrate is defined by the central portion and the periphery of the resist coating region. A resist coating apparatus characterized in that different parts are used. 2. The resist coating apparatus according to claim 1, wherein the central portion of the resist coating area of the nip roller has a larger diameter than the peripheral portion. 3. The resist coating apparatus according to claim 1, wherein the diameter of the central portion of the resist coating area of the nip roller is smaller than that of the peripheral portion.