JPH0938552A - Method and apparatus for coating rigid base sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the amt. of a coating liq. accumulated among wires of a microrod bar and to obtain a specified coating thickness by injecting air toward the tangential direction on the neighborhood of the top edge of the microrod bar in an apparatus for coating the coating liq. on the underside of a rigid base sheet by carrying the rigid base sheet while it is pinched. SOLUTION: A glass base sheet 10 is carried under a condition where both left and right edges of the glass base sheet 10 are placed on carrying rollers 22 and the underside of the glass base sheet 10 is coated with a liq. by means of a microrod bar 14 prepd. by winding a narrow stainless steel wire 14B on the surface so as to bring it into intimate contact with each other. In this case, air nozzles 30a and 30b are arranged below the glass base sheet 10, namely, the injection holes of the air nozzles 30a and 30b are arranged by directing them in the tangential direction on the neighborhood of the microrod bar 14. Then, as air injected from each air nozzle 30a and 30b hits along the grooves of the wires 14B exposed on the surface of the microrod bar 14, a coating liq. 12A sucked on the grooves accompanied with rotation of the microrod bar 14 is removed by air jet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for coating a hard substrate, which is used for manufacturing a liquid crystal display panel or the like using a glass substrate, and thinly and uniformly coats a coating liquid such as photoresist on a hard substrate. It is a thing.

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal plate, there is a process of applying a coating liquid such as a photoresist to a thin and uniform thickness on a hard substrate such as a glass substrate. For example, in the production of a color liquid crystal plate, a transparent electrode is formed on a glass substrate in advance,
After uniformly applying a red color mosaic liquid having a photoresist function, the color mosaic corresponding to red is cured by exposure, and a red color mosaic is formed by removing an uncured portion. . Then, the same processing is repeated for other colors such as green and blue. When a coating liquid to be a photoresist is applied as described above, it is necessary to strictly control this liquid to a uniform thickness (for example, about 2 μ ± 5%) and to apply the thin liquid. This is because if the thickness of the coating is non-uniform, the light transmittance becomes uneven, which leads to a deterioration in quality.

Conventionally, a spin coater has been used for this coating. This spin coater is one in which a coating liquid is dropped near the center of rotation of a rotated substrate and the liquid is scattered by utilizing centrifugal force to apply the liquid. However, in the method using this spin coater, not only the labor efficiency for replacing the substrate is deteriorated but also the amount of the liquid scattered and discarded increases. Therefore, there is a problem that the cost is increased.

In view of this, it has been considered to use an apparatus for coating a substrate between a pair of upper and lower rollers disposed horizontally. In this device, the lower part of the micro rod bar, which is the lower roller, is immersed in the coating solution, and the substrate is sandwiched between the micro rod bar and the nip roller located above the micro rod bar. It is to be applied.

The microrod bar used here has a coating portion having the same length as the width of the hard substrate. That is, the wire is closely wound by the same length as the width of the hard substrate, and has a small diameter on both sides of this portion (coating portion).

[0006]

However, a large amount of the coating liquid adheres to the edge of the coating portion of the microrod bar, that is, the outer edge of the area where the wire is wound, and this adheres to the hard substrate.
Therefore, there is a problem that the coating liquid is thickly applied to both edges of the hard substrate.

Further, in the microrod bar, solder is put on and fixed to a certain range on both ends of the portion where the wire is closely wound, and the outer peripheral surface of this range is polished to a smooth surface.
Utilizing the fact that the coating liquid is less likely to adhere to the polished surface, the coating liquid is prevented from being thickly applied to both edges of the hard substrate facing this surface. However, in reality, some coating liquid is attached to this polished portion and is coated on the hard substrate.

If a thicker film than necessary is formed on both edges of the hard substrate in this manner, it is not completely removed during development and remains as a residual film. This residual film comes into contact with the transport roller during transport and peels off. The coating film peeled off in this manner causes contamination (adhesion of dirt), resulting in deterioration of product quality.

Further, conventionally, since the microrod bar having the length of the coating portion corresponding to the width of the hard substrate was used, the microrod bar had to be changed when the width of the hard substrate was different. For this reason, it is necessary to prepare microrod bars having different sizes for hard substrates having different sizes, and there is a problem that the replacement work is troublesome and the operation rate of the apparatus is lowered.

Further, it may be desirable to apply the coating solution only to a partial range, divide the application area into a plurality of areas, or apply a shape other than a rectangle, instead of applying the application liquid to the entire surface of the hard substrate. . However, the conventional device has a problem that it cannot meet such a request.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is a first object of the present invention to provide a hard substrate coating method capable of controlling the coating thickness or coating region. A second object is to provide a hard substrate coating device which is directly used for carrying out this method.

[0012]

According to the present invention, a first object is to immerse a lower portion of a microrod bar wound with a wire closely attached to the outer periphery of the rod in a coating solution tank, and to dispose the microrod bar and the upper portion thereof facing each other. In a hard substrate coating method of applying a coating liquid to the lower surface of the hard substrate by sandwiching and feeding the hard substrate between the nip roller and the nip roller, air is directed toward the tangential direction near the upper edge of the microrod bar. It is achieved by a method for coating a hard substrate, characterized in that the coating thickness is controlled by sending the hard substrate while controlling the amount of the coating liquid that is sprayed and the amount of the coating liquid stored between the wires of the microrod bar.

It is also possible to remove the coating liquid accumulated between the wires of the microrod bar by the jetting air and control the coating area by changing the range and jetting timing of the jetting air.

A second object is to immerse the lower part of a microrod bar, in which a wire is tightly wound around the outer periphery of the rod, into the coating solution tank, and between the microrod bar and a nip roller arranged above it. In a hard substrate coating device that applies a coating liquid to the lower surface of the hard substrate by sandwiching the hard substrate between them, the hard substrate coating apparatus is disposed near the lower surface of the hard substrate and has a tangent line near the upper edge of the microrod bar. A hard substrate coating apparatus, characterized by comprising an air nozzle that directs air in a direction to control the amount of coating liquid stored between the wires of the microrod bar.

It is suitable to prevent thick coating of both edges of the hard substrate by providing a pair of left and right air nozzles and injecting air obliquely toward the outside of the hard substrate. Further, if at least one of the air nozzles is capable of changing its position in the width direction of the hard substrate, it is possible to cope with a hard substrate having a different width without exchanging the microrod bar.

If the air nozzle is provided at a position other than both edges of the hard substrate, a non-coated portion parallel to the feeding direction of the hard substrate can be formed, and if it is extended over the entire width of the hard substrate, the hard substrate is fed. It is possible to form a non-applied portion that is orthogonal to the direction. Further, by applying while moving the air nozzle in the width direction of the hard substrate or applying while changing the air jet width of the air nozzle, it is possible to obtain an applied portion having an arbitrary shape.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall layout view of an embodiment of the present invention, FIG. 2 is a perspective view of its coating portion, FIG. 3 is a view showing a state in which the nip roller is removed, and FIG. 4 is in FIG. FIG. 5 is a vertical sectional view including the center line of the micro rod bar, FIG. 6 is a partially enlarged vertical sectional view for explaining the principle of the present invention, and FIG. 7 is a sectional view taken along line VII-VII thereof. It is a figure.

In the figure, reference numeral 10 is a glass substrate used for a color filter of a liquid crystal plate, which is a hard substrate. The glass substrate 10 has a width of 300 to 500 m, for example.
m, length 400-700mm, thickness 0.7-1.1mm
belongs to.

Reference numeral 12 denotes a coating solution tank, and 14 denotes a micro rod bar. The micro rod bar 14 is a stainless steel rod 14A (see FIGS. 6 and 7) having a circular cross section, and a thin stainless wire 14B (see FIGS. 6 and 7) wound around the surface of the rod 14A so as to closely adhere to each other. The liquid is applied by utilizing the capillary phenomenon. The micro rod bar 14 is a backup material 16 provided in the coating liquid tank 12.
The motor is driven in the state shown in FIGS.

The liquid surface of the coating liquid is controlled to be constant so that the lower part of the micro rod bar 14 is sufficiently immersed. The outer diameter (diameter) of the micro rod bar bar 14 is about 12
mm. A nip roller 20 is held above the micro rod bar 14.

The glass substrate 10 is conveyed at a constant speed from the left side of FIGS. 2 and 3 with its left and right edges placed on the conveying roller 22, and its front edge enters between the micro rod bar 14 and the nip roller 20. Reference numeral 24 in FIGS. 2 and 3 denotes a case for accommodating the drive mechanism of the transport roller 22.

Thereafter, the glass substrate 10 is sent to the right at a constant speed by the rotation of the micro rod bar 14 and the nip roller 20, while the micro rod bar 1
Therefore, the liquid is applied to the lower surface of the glass substrate 10. Then, the left and right edges of the glass substrate 10 on which the coating has been completed are placed on the transport rollers 22 and further fed to dry the coating liquid.

Next, the air nozzle 30 will be described. In this embodiment, a pair of left and right air nozzles 30a and 30b are provided.
The coating portion of the microrod bar 14 has substantially the same length as the width of the glass substrate 10, and the wire 14B is wound around this coating portion. The wire 1 of this micro rod bar 14
Both ends of 4B are wound around the end surface 14C (FIG. 6) of the coating portion of the rod 14A and fixed by soldering. Therefore, almost no solder appears on the outer peripheral surface of the applied portion, and the groove of the wire 14B appears in almost the entire area of the applied portion.

The air nozzles 30a and 30b are the glass substrate 1
It is below 0 and has a horizontally long jet. Each jet port directs air in a tangential direction near both edges of the microrod bar 14. In addition, each air nozzle 30a, 30b
Blows air by obliquely pointing the outside of the hard substrate 10.
32 and 32 (32a, 32b) in FIGS.
It is a pipe that supplies 0.01 to 0.2 kgf / cm ² of air to a and 30b.

These air nozzles 30a and 30b are bolted to the side surface of the coating liquid tank 12 on the side where the glass substrate 10 enters. The air nozzles 30a and 30b are the glass substrate 1
It is desirable to be able to adjust the position according to the width of 0.

The air jetted from these air nozzles 30a, 30b hits the groove 14D along the groove 14D of the wire 14B appearing on the surface of the microrod bar 14 as shown in FIG. Therefore, as the microrod bar 14 rotates, the coating liquid 12A (FIGS. 6 and 7) sucked up by the groove 14D is removed by this air jet. FIG. 7
A broken line 14E attached along the wire 14B indicates the contact line between the closely wound wires 14B.
There is no air underneath, so the coating liquid 12A remains here.

Since the air nozzle 30 jets air obliquely outside the glass substrate 10, the air that has passed through the groove 14D of the wire 14B and the coating liquid 12A pushed out from the groove 14D by this air are the microrod bar. It flows to the outside of the coating section of 14. Therefore, it is possible to prevent the air flow and the flowing-out coating liquid 12A from adversely affecting the coating surface of the glass substrate 10.

In the coating liquid tank 12, blocks 34 (34a, 34b, 34b) are provided at positions corresponding to the vicinity of both edges of the glass substrate 10.
It is desirable to dip FIG. 4 and 5) to reduce the amount of coating liquid adhering to the microrod bar 14. Here, this block 34 is immersed in the entrance side of the glass substrate 10.

Although the air nozzle 30 is provided on the entrance side of the glass substrate 10 in this embodiment, it may be provided on the opposite side, that is, on the exit side of the glass substrate 10. The phantom line in FIG. 4 shows the air nozzle 30A arranged at this position. Glass substrate 1
The air nozzles 30 and 30A may be provided on both the entry side and the exit side of 0. One of the air nozzles 30 or 30A
May be used as a suction nozzle to suck air passing through the groove 14D of the wire 14B.

FIG. 8 is a perspective view showing another embodiment. In this embodiment, the air nozzle 30B is movable. That is, an air nozzle 30B is held on the side surface of the coating liquid tank 12 by a linear bearing 36 so as to be movable in the width direction of the glass substrate 10, and this air nozzle 30B is connected to a wire 40 that reciprocates by a motor 38. Therefore, the position of the air nozzle 30B can be changed by the motor 38.

Therefore, if air is moved from the air nozzle 30B while being ejected, coating is not performed along the movement locus of the air nozzle 30B, and the non-coating portion of the coating surface can be arbitrarily moved. For example, the non-coated portion can be formed in a stripe shape. This air nozzle 3
If 0B is used, even if the width of the hard substrate 10 changes when the non-coated portion is formed on the edge of the glass substrate 10, it can be quickly dealt with.

FIG. 9 is a perspective view showing another embodiment of the present invention. The air nozzle 30C of this embodiment has a plurality of ejection ports divided in the width direction of the glass substrate 10, and each ejection port is controlled so as to selectively eject air.

10 to 14 are views showing examples of coating according to the present invention. In FIG. 10, the non-coated portions 50, 50 are formed along both the left and right edges of the glass substrate 10, and the coated portion 52 having a constant width is formed in the central portion. This is, for example, 1 to 7 above
It can be obtained by using the pair of left and right air nozzles 30a and 30b described above.

In FIG. 11, the coating portion 52 is divided into two regions by adding a non-coating portion 50 in the width direction. Such an application mode is the air nozzle 3 shown in FIG.
It is obtained by using 0C. That is, the air outlets of the air nozzles 30C corresponding to the left and right edges of the glass substrate 10 constantly eject air, while the air is ejected from all the ejection ports of the air nozzles 30C at a constant timing in synchronization with the feeding of the glass substrate 10. .

In FIG. 12, similarly, the air nozzle 30C is used to constantly eject air from the ejection port located at the center in the width direction. In this case, the coating part 52 can be divided into four regions. In FIG. 13, an air nozzle 30D having a large number of finely divided ejection ports is used, and the ejection of air from each ejection port can be appropriately switched. In this case, the coating portion 52 having an arbitrary shape can be obtained by switching the injection ports.

In each of the above embodiments, the air nozzles 30, 3
The non-application portion 50 is formed by almost completely removing almost all the coating liquid stored in the groove 14D of the wire 14B by the air jetted from 0A to 30D. But groove 14D
The amount of the coating liquid inside can be controlled by the flow rate or the jet pressure of the air jetted from the air nozzle, and the coating thickness may be controlled in this way.

[0037]

As described above, according to the first aspect of the present invention, since the amount of the coating liquid stored in the groove between the wires of the microrod bar is controlled by the air jetted toward this groove, the jetting position is controlled. The coating thickness can be controlled by controlling the amount of air to be jetted or the air pressure. Therefore, by injecting air in this way on both left and right edges of the hard substrate, thick coating on both edges can be prevented.

Further, even if the width of the hard substrate changes, it can be dealt with only by changing the position of the air nozzle, and it becomes unnecessary to change the microrod bar. As a result, work efficiency improves,
The operation rate of the device is improved. Further, the shape of the coating portion can be arbitrarily changed by changing the range and the injection timing of air.

According to the third aspect of the invention, an apparatus used for carrying out this method is obtained. If a pair of left and right air nozzles are provided so as to inject air obliquely toward the outside of the hard substrate from positions near the left and right edges of the hard substrate, a non-coated portion is formed along both edges of the hard substrate. Yes (claim 4).
If the position of the air nozzle can be changed in the width direction of the hard substrate, it is possible to easily cope with hard substrates having different widths (claim 5). If the air nozzles are provided at positions other than both edges in the width direction of the hard substrate, the coating portion can be divided in the width direction of the hard substrate (claim 6).

Further, by using an air nozzle having a long width over the entire width of the hard substrate, the coating portion can be divided in the feeding direction of the hard substrate (claim 7). Further, if the ejection port of the air nozzle is divided into a large number in the width direction of the hard substrate, or if the air nozzle is movable in the width direction, it is possible to apply in any shape.

[Brief description of drawings]

FIG. 1 is an overall layout diagram of an embodiment of the present invention.

FIG. 2 is a perspective view of the coating section.

FIG. 3 is a diagram showing a state in which the nip roller is removed.

FIG. 4 is a cross-sectional view near the air nozzle in FIG.

FIG. 5 is a vertical sectional view including a center line of a micro rod bar.

FIG. 6 is a partially enlarged vertical sectional view for explaining the principle of the present invention.

FIG. 7 is a sectional view taken along the line VII-VII.

FIG. 8 is a diagram showing another embodiment.

FIG. 9 is a diagram showing another embodiment.

FIG. 10 is a view showing an application example according to the present invention.

FIG. 11 is a view showing an application example according to the present invention.

FIG. 12 is a diagram showing a coating example according to the present invention.

FIG. 13 is a diagram showing a coating example according to the present invention.

[Explanation of symbols]

 10 Glass Substrate as Hard Substrate 12 Coating Liquid Tank 14 Micro Rod Bar 14A Rod 14B Wire 14D Groove 20 Nip Roller 30, 30A to 30D Air Nozzle 34 Block 50 Non-Coating Section 52 Coating Section

Front page continued (72) Inventor Shinya Yamazaki 1005 Kozoen, Ayase City, Kanagawa Prefecture, Fuji Micrographix Co., Ltd. (72) Inventor Hirofumi Kumagai, 1005 Kozoen, Ayase City, Kanagawa Prefecture

Claims (7)

[Claims] 1. A lower part of a micro rod bar wound with a wire tightly wound around the outer periphery of the rod is immersed in a coating liquid tank, and a hard substrate is sandwiched between the micro rod bar and a nip roller arranged opposite thereto. In the hard substrate coating method of applying a coating liquid to the lower surface of the hard substrate by sending by, the air is jetted in the tangential direction near the upper edge of the microrod bar, and the jetted air of the microrod bar A method for coating a hard substrate, characterized in that the coating thickness is controlled by feeding the hard substrate while controlling the amount of coating liquid stored between the wires. 2. A lower part of a micro rod bar wound by tightly winding a wire on the outer circumference of the rod is immersed in a coating liquid tank, and a hard substrate is sandwiched between the micro rod bar and a nip roller arranged above the micro rod bar. In the hard substrate coating method of applying a coating liquid to the lower surface of the hard substrate by sending by, the air is jetted in the tangential direction near the upper edge of the microrod bar, and the jetted air of the microrod bar A method for coating a hard substrate, characterized in that a coating area is controlled by removing a coating liquid accumulated between the wires and changing a jetting range and a jetting timing of jetting air. 3. A lower portion of a micro rod bar wound with a wire closely attached to the outer circumference of the rod is dipped in a coating liquid tank, and a hard substrate is sandwiched between the micro rod bar and a nip roller arranged facing the micro rod bar. In the hard substrate coating device for coating the coating liquid on the lower surface of the hard substrate, the hard substrate coating apparatus is disposed in proximity to the lower surface of the hard substrate, and is oriented in the tangential direction near the upper edge of the microrod bar. A hard substrate coating apparatus comprising an air nozzle for injecting air to control the amount of coating liquid accumulated between the wires of the microrod bar. 4. The hard substrate coating apparatus according to claim 3, further comprising a pair of left and right air nozzles for obliquely directing air from a position near both edges of the hard substrate of the microrod bar and obliquely directing to the outside of the hard substrate. 5. The hard substrate coating apparatus according to claim 4, wherein at least one of the air nozzles can change its position in the hard substrate width direction. 6. The hard substrate coating apparatus according to claim 3, further comprising an air nozzle which is located at a position other than both edges within the width of the hard substrate and forms an uncoated portion parallel to the feeding direction of the hard substrate. 7. The hard substrate coating apparatus according to claim 3, wherein the hard substrate coating device is provided with a long air nozzle over the entire width of the hard substrate so that a non-coating portion orthogonal to the feeding direction of the hard substrate can be formed.