JPH06138662A - Method for applying coating liquid on substrate surface - Google Patents

Abstract

PURPOSE:To prevent film-thickness from being increased at the rear edge of the substrate in the transporting direction when a coating liquid is applied to the substrate. CONSTITUTION:A coating auxiliary tool 23 is thicker than the square shaped substrate W and is closely in contact with the rear edge surface of the substrate W at the whole width and has some length in the transporting direction of the substrate W. The coating auxiliary tool 23 is arranged at the rear edge side of the square shaped substrate W in the transporting direction, the square shaped substrate W and the coating auxiliary tool 23 are integrally moved and the coating liquid is applied to their surfaces by an applicator roll 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies a coating liquid such as a photoresist liquid, a polyimide resin or a color filter material to a rectangular substrate such as a glass substrate for a photomask or a glass substrate for a liquid crystal display device. In order to form a uniform thin film, the coating liquid is supplied to the outer peripheral surface of the applicator roll, and the coating liquid is rotated by rotating the applicator roll on the surface of the substrate that is horizontally moved relative to the applicator roll. The present invention relates to a method for applying a coating liquid on the surface of a substrate for applying the.

[0002]

2. Description of the Related Art As a method for applying the above-mentioned coating solution, a method disclosed in Japanese Utility Model Laid-Open No. 2-133470 has been known. In this known example, a coating liquid storage part for storing the coating liquid is formed between a doctor roll and a coating roll (applicator roll), and the coating roll is rotated from the coating liquid storage part by rotating the coating roll at a constant speed. The coating liquid is adhered in a film form on the outer peripheral surface, and the coating liquid is applied to the substrate which is conveyed in the horizontal direction below the coating liquid.

[0003]

However, in the case of the conventional example, when the coating roll and the substrate are separated from each other at the trailing edge of the substrate in the transport direction and the application of the coating liquid is completed, the coating liquid adheres to the coating roll. The coating liquid and the coating liquid applied to the substrate side pull each other and are cut by the tension, and the cut portion is returned to the trailing edge side of the substrate in the conveyance direction by the tension, and the coating at the trailing edge of the substrate conveyance direction is performed. The thickness of the film is, for example, about 1.5 to 3 times as large as that of the central portion in the transport direction of the substrate, which is thicker than other portions. Then, when the film thickness becomes thick as described above, in the case where the photoresist liquid is applied as the coating liquid, in the contact baking process performed subsequent to the coating liquid application process, sufficient adhesion with the exposure mask is obtained. Was not obtained, and there was a defect that the baking quality was deteriorated. Further, in the developing process performed after the contact baking process, there is a drawback that the undeveloped portion is left on an unnecessary portion at the rear edge of the substrate in the transport direction.

The present invention has been made in view of such circumstances, and it is an object of the present invention to prevent the film thickness from increasing at the trailing edge of the substrate in the carrying direction.

[0005]

In order to achieve the above-mentioned object, the present invention supplies a coating liquid to the outer peripheral surface of an applicator roll and is horizontally moved relative to the applicator roll. Rotating the applicator roll on the surface of the substrate to apply the coating liquid In the method of applying the coating liquid to the surface of the substrate, the rear end side in the moving direction of the substrate is adhered to the rear end face of the substrate over its entire width and more than the thickness By arranging a coating aid having a length in the moving direction of the substrate, the substrate and the coating aid are integrally moved, and the coating liquid is applied to their surfaces by an applicator roll. There is.

[0006]

According to the constitution of the method for applying a coating liquid on the surface of the substrate of the present invention, the position at which the coating with the applicator roll is finished is set from the rear edge of the substrate by bringing the coating auxiliary tool into close contact with the rear edge of the substrate. Avoiding the existence of thick parts on the substrate surface by shifting, finishing the application to the application aid, increasing the film thickness on the application aid, and finally removing the application aid it can.

[0007]

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

FIG. 1 is a partially cutaway overall side view showing an embodiment of a roll coater used for carrying out a method for applying a coating liquid on a substrate surface according to the present invention, FIG. 2 is an overall plan view thereof, and FIG. FIG. 3 is an enlarged side view of FIG. 1, in which a substrate transfer stage 2 is provided on the base 1 so as to be capable of reciprocating in the horizontal direction.
A support frame 3 is provided so as to be vertically swingable around a horizontal first axis P1 on the lower side in the substrate transport direction, and the support frame 3 is horizontally moved at a position close to the first axis P1. The upper support frame 4 is capable of swinging up and down around the second axis P2 of
Is provided.

On the upper support frame 4, a metal roll 5 made of a metal having a smooth peripheral surface, and a metal doctor 7 having a peripheral surface formed in a substantially arc shape by the step portions 6 and 6 for shearing the coating liquid are arranged in a horizontal direction. They are arranged side by side so that they can rotate around their axes.

The outer peripheral surface of the metal roll 5 and the metal doctor 7
And an outer peripheral surface of the coating liquid storage section 8 are disposed close to each other with a predetermined gap therebetween, and a coating liquid storage portion 8 that stores the coating liquid is formed by the both outer peripheral surfaces. The size of the gap formed between the outer peripheral surface of the metal roll 5 and the outer peripheral surface of the metal doctor 7 can be adjusted by horizontally moving the metal doctor 7 relative to the metal roll 5. The gap is adjusted according to the viscosity of the coating liquid stored in the liquid storage section 8 and the like.

The coating liquid storage section 8 is provided with a coating liquid supply nozzle 9 which also serves as a stirring means in a state where the tip thereof penetrates into the coating liquid, and the coating liquid supply nozzle 9 is arranged in the longitudinal direction of the metal roll 5. It is movably provided by a rodless cylinder (not shown) installed in a posture parallel to, and the coating solution stored in the coating solution storage section 8 is stirred along with the movement and the coating solution storage section 8 is It is configured so that the coating liquid can be supplied.

A scraper 10 and a tray 11 are provided on the lateral side of the metal roll 5, and the scraper 10 and the tray 11 are applied to the rectangular substrate W while being stored in the coating liquid storage portion 8 and once attached to the outer peripheral surface of the metal roll 5. Instead, the residual coating liquid remaining on the outer peripheral surface of the metal roll 5 is collected.

An applicator roll 12 made of butyl rubber having a smooth outer peripheral surface and having elasticity is attached rotatably around a horizontal axis at a position on the upper side of the support frame 3 in the substrate carrying direction, and is made of metal. The rolls 5 and 12 rotate in the same direction so that the rolls 5 are relatively distant from the applicator roll 12 and the surfaces that are close to each other move in opposite directions at the positions where the rolls 5 are close to each other. It is configured to transfer the coating liquid that has adhered to and is supplied from the coating liquid storage unit 8 to the applicator roll 12.

A substrate loading device 13 is provided on one side of both ends of the rectangular substrate W in the transport direction of the base 1, and a substrate unloading device 14 is provided on the other side thereof. Each of the substrate loading device 13 and the substrate unloading device 14 is a direction in which the rectangular substrate W is placed and transported, and the rectangular substrate W is sucked and held by vacuum suction to approach the base 1. And a substrate suction arm 16 that is movable up and down.

Substrate transport rollers 15 ...
A brim 17 for restricting the width of the rectangular substrate W in the direction orthogonal to the transport direction is additionally provided, while in the substrate loading device 13,
Stoppers 18, 18 are provided at the rear end in the transport direction,
The square substrate W transported by the substrate transport rollers 15 is maintained in a predetermined posture at the front end in the transport direction, and the square substrate W is suction-held by the substrate suction arm 16 and lifted, and is loaded onto the substrate transport stage 2. Is configured to.

The substrate transfer stage 2 comprises a pair of guides 1.
The substrate mounting stage 22 has a substrate mounting stage 22 which is guided by 9 and 19 so as to be horizontally movable in the carrying direction.
2 has a rectangular substrate W mounted on the upper surface thereof, the rectangular substrate W
In comparison with the above, it has a larger dimension in the carrying direction and in the direction orthogonal to the carrying direction. Further, the substrate mounting stage 22 is configured to be horizontally moved in the carrying direction by a screw 21 which is rotated by an electric motor 20 having a zero-point detector and capable of forward and reverse rotation.

Next, a method of applying the coating liquid on the substrate surface according to the present invention, which is performed by using the roll coater configured as described above, will be described. First, the coating aid 23 used in this method will be described. As shown in FIG. 4, it has a thickness equal to that of the rectangular substrate W, a predetermined length in the moving direction thereof, and a longitudinal direction thereof. The coating aid 23 is configured so that the length is longer than the width of the rectangular substrate W.

Then, as shown in the schematic side views of FIGS. 5A and 5B, the rectangular substrate W is placed on the substrate mounting stage 22 by the substrate suction arm 16 on the substrate loading device 13 side.
After loading the rectangular substrate W, the rectangular substrate W is moved to the rear end side in the moving direction of FIG.
As shown in the schematic side view of (c) of FIG. 4 and the schematic perspective view of FIG. 4, the side faces are closely attached to the end face of the rectangular substrate W, and both ends in the longitudinal direction project from both ends in the width direction of the rectangular substrate W. Arrange the application aid 23 in a state where
As shown in the schematic side view of FIG. 5D, the rectangular substrate W and the coating aid 23 are integrally moved, and the coating liquid is coated on their surfaces by the applicator roll 12.

Apply the application liquid also on the application aid 23,
After moving to the transfer position for the substrate unloading device 14,
The coating aid 23 is removed, and the rectangular substrate W coated with the coating liquid is unloaded by the substrate suction arm 16 on the substrate unloading device 14 side. The removed coating aid 23 is reused after the coating liquid applied is washed and removed by a solvent or the like and dried.

With the above construction, the coating aid 23 having the thickened portion of the coating liquid is removed, and the rectangular substrate W is coated with the coating liquid with a uniform thickness up to the rear edge in the moving direction. Can be obtained.

FIG. 6 is a schematic side view showing another embodiment of the method for applying the coating liquid on the substrate surface of the present invention, in which only the rear end of the rectangular substrate W in the moving direction is placed on the substrate mounting stage 22. Instead, the coating aid 23a having the same configuration is also arranged at the front end in the moving direction, and the application of the coating solution is started from the coating aid 23a arranged at the front end in the moving direction. The application aid 23a is also removed after the application of the application liquid and is reused after the cleaning process.

According to this alternative embodiment, when the applicator roll 12 is lowered to start the coating of the coating liquid, its lowered position can be on the coating aid 23a.
There is an advantage that it is unnecessary to control the descending speed with high precision in order to prevent the film thickness from varying in the initial stage. In addition, the substrate mounting stage 22 is reciprocally moved and overcoated, and the rectangular substrate W is moved in the direction opposite to the initial movement direction.
There is an advantage that it is possible to cope with the case where the coating liquid is moved to complete the coating of the coating liquid.

FIG. 7 is a schematic side view showing still another embodiment of the method of applying the coating liquid on the substrate surface of the present invention, in which a plurality of rectangular substrates W are continuously fed by a belt type transport device 24 or the like. It is configured so that it can be transported, and coating aids 23b are arranged between adjacent rectangular substrates W, W respectively, so that the coating liquid can be coated on a large number of rectangular substrates W by reducing the number of times of raising and lowering the applicator roll 12. It has become.

As the coating aid, as shown in the schematic side view of FIG. 8 (a), the coating aid 23c having a slope F1 with its rear end side in the moving direction of the upper surface facing downward, or On the contrary, as shown in the schematic side view of FIG. 8B, the inclined surface F2 whose upper end faces the moving direction rear end side upward
Various types of components such as the coating aid 23d configured in the above can be used. The thickness of the portion of the coating aid that contacts the rear end of the rectangular substrate in the moving direction should be slightly larger than the thickness of the rectangular substrate in order to prevent the coating liquid from flowing to the side surface of the rectangular substrate. Good.

The present invention is not limited to the roll coaters of the above-mentioned embodiments, but roll coaters of various configurations such as a roll coater of the type configured to supply the coating liquid by a gravure metal roll can be used.

[0026]

As described above, according to the method for applying the coating liquid on the substrate surface of the present invention, the film thickness is made thicker on the rear end edge of the substrate by increasing the film thickness on the coating aid. Therefore, it is possible to prevent the deterioration of the baking quality and the occurrence of the undeveloped residue due to the thick film thickness, thereby improving the quality. In order to prevent the film thickness from increasing at the trailing edge of the substrate, for example, the moving speed of the substrate is increased on the trailing edge side of the substrate, or the rotation speed of the applicator roll is increased to increase the substrate speed. In the case where the amount of coating liquid supplied to the rear edge of the substrate is reduced so that the film thickness does not become substantially thick, a sensor for detecting that the rear edge of the substrate has reached the coating position and a high accuracy are provided. Although speed control is required, according to the present invention, there is an advantage that those sensors and control are unnecessary and the configuration can be simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a partial cutaway overall side view showing an embodiment of a roll coater used for carrying out a method for applying a coating liquid on a substrate surface according to the present invention.

FIG. 2 is an overall plan view.

FIG. 3 is an enlarged side view of a main part.

FIG. 4 is a perspective view showing a main part of an embodiment of an application aid used in the present invention.

5 is a schematic side view of a main part for explaining an embodiment of a method for applying a coating liquid on a substrate surface according to the present invention using the coating aid shown in FIG.

FIG. 6 is a schematic side view of essential parts for explaining another embodiment of the method for applying a coating liquid on the surface of a substrate according to the present invention.

FIG. 7 is a schematic side view of a main part for explaining still another embodiment of the method for applying a coating liquid on the surface of a substrate according to the present invention.

FIG. 8 is a schematic side view showing a modified example of the coating aid.

[Explanation of symbols]

 12 ... Applicator roll 23 ... Application aid W ... Square substrate

Claims (1)

[Claims] 1. A substrate for applying a coating liquid to the outer peripheral surface of an applicator roll and rotating the applicator roll on the surface of a substrate that is horizontally moved relative to the applicator roll. In the method of applying a coating liquid on the surface, on the rear end side in the moving direction of the substrate, the entire width of the rear end face of the substrate is adhered to the rear end surface of the substrate at a thickness equal to or more than the thickness of the substrate, and a coating aid having a length in the moving direction of the substrate is assisted. A coating solution is applied to the surface of a substrate, wherein a tool is arranged, the substrate and the coating aid are moved integrally, and the coating solution is coated on their surfaces by the applicator roll.