JPH0975812A - Roll coater - Google Patents

Abstract

(57) Abstract: In a reverse coating type roll coater for transporting a substrate by a transport roll, even if there is a difference between the substrate transport speed by the transport roll and the substrate transport speed by the backup roll, Provided is a roll coater in which the front end of the substrate does not damage the peripheral surface of the applicator roll when the substrate is fed to the position of the backup roll. A plurality of transfer rolls 22 arranged in front of an applicator roll 12 and a backup roll 24 in a transfer direction of a substrate W transmit a rotational force to the substrate when an external force is not applied thereto. When an external force was applied through the substrate, the free roll was idled as the substrate moved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass substrate for liquid crystals, a substrate for film liquid crystals, a substrate for image sensors, a substrate for printed wirings, a semiconductor wafer, and various other substrates in a horizontal direction while the applicator roll is used as a substrate. By contacting and rotating the surface of the applicator roll, a coating liquid, such as a photoresist liquid or a polyimide resin, is applied to the substrate surface through the peripheral surface of the applicator roll to form a coating film having a predetermined film thickness on the substrate surface. Roll coater used to form,
In particular, a backup roll is arranged below the applicator roll, the applicator roll is rotated in the direction opposite to the substrate transport direction, and the substrate is sent to the backup roll position to create a gap between the applicator roll and the backup roll. The present invention relates to a so-called reverse coating type roll coater which is used for passing through.

[0002]

2. Description of the Related Art As a reverse coating type roll coater, one disclosed in, for example, Japanese Utility Model Laid-Open No. 4-99266 is generally known. In this roll coater, the substrate is vacuum-sucked on the surface plate and integrally held, and is transported in the horizontal direction, while the applicator roll disposed above the transfer path has the lowest point on the surface plate. The substrate is rotated in the direction opposite to the substrate transport direction while being lowered to a position where it comes into contact with the substrate surface. Then, the substrate held on the surface plate passes underneath while contacting the peripheral surface of the applicator roll, whereby the coating liquid supplied to the peripheral surface of the applicator roll is transferred from the peripheral surface of the applicator roll to the substrate. Is transferred to the surface of the substrate to form a coating film having a predetermined film thickness on the surface of the substrate.

However, as described above, in the reverse coating type roll coater which holds and conveys the substrate on the surface plate, the substrate is placed on the surface plate upstream of the applicator roll in the substrate conveyance direction. It is necessary to provide a substrate transfer mechanism for this purpose, or to equip the surface plate with a vacuum suction device, and to mount the substrate on the surface plate and perform vacuum suction. Further, it is necessary to provide a substrate transfer mechanism for lowering the substrate from the surface plate also on the downstream side of the applicator roll in the substrate transport direction, and to release the substrate from the surface plate by releasing the vacuum suction. Operation is required. As described above, the conventionally known reverse coating type roll coater has a complicated apparatus configuration,
There was a problem that extra operations were required.

Therefore, as a roll coater capable of performing reverse coating without requiring a complicated mechanism or extra operation, the back side of the substrate is contacted to support the substrate on the lower side of the applicator roll. A backup roll that rotates in the transport direction and transports the substrate is provided, and a plurality of applicator rolls and backup rolls are provided on the front side and the opposite side of the substrate transport direction, respectively, along the substrate transport direction. A roll coater configured by arranging transport rolls in line has been proposed. In this roll coater, while rotating the applicator roll in the direction opposite to the substrate transport direction, the substrate is moved to the backup roll position by the transport rolls arranged in front of the applicator roll and the backup roll in the substrate transport direction. The substrate is sent forward by a backup roll that is driven to rotate in the substrate transport direction, and the substrate is passed through the gap between the applicator roll and the backup roll while the substrate surface is in contact with the applicator roll. The coating liquid supplied to the peripheral surface of the tallow roll is transferred from the peripheral surface of the applicator roll to the surface of the substrate to form a coating film having a predetermined film thickness on the surface of the substrate.

[0005]

However, a backup roll is disposed below the applicator roll, and a plurality of transport rolls are disposed before and after the backup roll, and the substrate is covered by the transport roll and the backup roll. In a roll coater that performs reverse coating with an applicator roll disposed above the backup roll while transporting, if the substrate transport speed of the transport roll and the substrate transport speed of the backup roll are different, for example, substrate transport If the substrate transfer speed by the transfer rolls for feeding substrates arranged in front of the backup roll in the direction is higher than the substrate transfer speed by the backup roll, when the substrate is sent to the backup roll position by the transfer roll, of It may damage the peripheral surface of the applicator roll by the end. Further, if there is a difference between the substrate transport speed by the transport roll and the substrate transport speed by the backup roll, the coating speed formed on the surface of the substrate is uneven due to the influence of the change in the substrate transport speed in the middle. May appear, or friction may occur between the substrate and the transfer roll or the backup roll to cause dirt or scratches on the back surface of the substrate.

The problem caused by the difference in the transfer speed of the substrate as described above is solved by providing a control device for accurately controlling the transfer roll and the backup roll so that the transfer speeds of the substrates are always equal. It is possible. However, in that case, the configuration of the apparatus becomes complicated, and the adjustment work of the drive device for the transport rolls and the backup roll becomes troublesome.

The present invention has been made in view of the above circumstances, and even if there is a difference between the substrate transport speed by the transport roll and the substrate transport speed by the backup roll, the substrate is backed up by the transport roll. There is no concern that the front end of the substrate will damage the peripheral surface of the applicator roll when it is fed to the roll position, and the coating film formed on the surface of the substrate may become uneven or the back surface of the substrate may become dirty or scratched. It is an object of the present invention to provide a roll coater of a reverse coating system which is free from the possibility of occurrence of rust.

[0008]

The invention according to claim 1 is
A backup roll, which is in contact with the back surface of the substrate and supports the substrate and rotates in the substrate transport direction, is arranged above the backup roll with a gap necessary for the substrate to pass between the backup roll and the backup roll. , An applicator roll that comes into contact with the surface of the substrate and rotates in a direction opposite to the transport direction of the substrate to transfer the coating liquid from the peripheral surface to the surface of the substrate, and the applicator roll and the backup roll in the transport direction of the substrate. In a roll coater having a plurality of transfer rolls provided on the front side and the opposite side thereof along the transfer direction of the substrate and feeding the substrate to the position of the backup roll and feeding it from that position, the applicator roll and the backup Free of the plurality of transfer rolls arranged in a row at least on the front side of the roll in the transfer direction of the substrate. And Lumpur, when no external force is applied to its respective conveyor rolls when the external force is applied through the substrate to transmit the rotational force to the substrate is characterized in that so as to idle in accordance with movement of the substrate.

According to a second aspect of the present invention, in the roll coater according to the first aspect, the plurality of transfer rolls arranged in line on the front side of the applicator roll and the backup roll in the substrate transfer direction are provided. It is arranged so that the substrate transfer direction is slightly downward with respect to the horizontal direction toward the backup roll, and after the front end of the substrate transferred by the transfer roll contacts the peripheral surface of the backup roll, the circumference of the applicator roll It is characterized in that it comes into contact with the surface.

In the roll coater of the invention according to claim 1,
For example, when the transfer speed of the substrate by the transfer rolls arranged in front of the applicator roll and the backup roll in the transfer direction of the substrate is higher than the transfer speed of the substrate by the backup roll, the substrate transferred by the transfer roll is When the front end comes into contact with the peripheral surface of the backup roll or the peripheral surface of the applicator roll, the force from the peripheral surface of the backup roll is applied to the transfer roll via the substrate, and the free transfer roll moves as the substrate moves. Spin idle. Therefore, the force from the transport roll does not act on the peripheral surface of the applicator roll via the substrate. In addition, the substrate receives the force from the backup roll during the period from when the front end of the substrate transported by the transport roll abuts the peripheral surface of the backup roll until the rear end of the substrate separates from the peripheral surface of the backup roll. It is transported at a constant speed and is not forced by the transport roll into the gap between the applicator roll and the backup roll. Therefore, even when the front end of the substrate is in contact with the peripheral surface of the backup roll, the substrate is not limited by the substrate transport speed of the transport roll. On the contrary, even when the substrate transfer speed by the backup roll is higher, when the substrate is transferred by receiving the force from the backup roll, the substrate does not receive the force from the transfer roll which is the free roll,
No friction occurs between the substrate and the transfer roll.

In the roll coater of the invention according to claim 2,
The front end of the substrate transported by the transport roll first contacts the peripheral surface of the backup roll, and then contacts the peripheral surface of the applicator roll. Then, as described above, after the front end of the substrate comes into contact with the peripheral surface of the backup roll, the substrate is transported by receiving the force from the backup roll without receiving the force from the transport roll. Force from the substrate does not act on the applicator roll through the substrate.

[0012]

Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing an example of an embodiment of the present invention and showing a schematic structure of a roll coater of a reverse coating type. The basic structure of the roll coater is no different from the conventional one. That is,
The roll coater shown in FIG. 1 is an applicator roll 1
2, a coating liquid supply unit 10 including an offset roll 14, a pickup roll 16 and a liquid storage tank 18.
And a substrate transport system 20 including a plurality of substrate transport rolls 22, a backup roll 24, and a plurality of substrate transport rolls 26.

The coating liquid supply unit 10 is attached to a fixed base (not shown) so as to be vertically movable. In the coating supply unit 10, a coating liquid, for example, a photoresist liquid (hereinafter referred to as “resist liquid”) 28 is stored in the liquid storage tank 18, and the resist liquid 28 in the liquid storage tank 18 has a pickup roll. A part of the peripheral surface of 16 is immersed. The pick-up roll 16 rotates around a horizontal axis in the illustrated example in a clockwise direction at a constant speed, and scrapes the resist liquid 28 upward from the liquid storage tank 18 and deposits it on the peripheral surface in a film shape. The offset roll 14 rotates around the horizontal axis,
In the illustrated example, it rotates counterclockwise (a direction opposite to the rotation direction of the pickup roll 16) at a constant speed. Here, the pickup roll 16 can be brought into and out of contact with the offset roll 14 so that the gap size thereof can be adjusted, and the resist liquid deposited on the peripheral surface of the pickup roll 16 in the form of a film is surrounded by the offset roll 14. The appropriate amount is transferred to the surface. In addition, the applicator roll 12 is in a state in which its peripheral surface is in contact with the peripheral surface of the offset roll 14,
In the illustrated example, it rotates counterclockwise around the horizontal axis at a constant speed, and the resist liquid adhering in a film form on the peripheral surface of the offset roll 14 is retransferred to the peripheral surface of the applicator roll 12. The remaining resist liquid transferred from the offset roll 14 to the applicator roll 12 is removed from the peripheral surface of the offset roll 14 by a scraper roll (not shown) attached to the offset roll 14 and collected in a tray or the like. A scraper roll that collects the remaining resist liquid may be provided on the applicator roll 12.

The backup roll 24, which constitutes a part of the substrate transfer system 20, is located below the applicator roll 12 and between the backup roll 24 and the peripheral surface of the applicator roll 12 when the coating liquid supply unit 10 descends. It is arranged so that a gap that is necessary for the substrate W to pass through, that is, a gap that is slightly smaller than the thickness dimension of the substrate W is formed. The backup roll 12 rotates around a horizontal axis in the illustrated example in a counterclockwise direction (the same direction as the rotation direction of the applicator roll 12) at a constant speed, and the peripheral surface of the substrate W is rotated.
It comes into contact with the back surface of the substrate W, supports the substrate W, and transports it in the horizontal direction.
The plurality of substrate-feeding transport rolls 22 and the plurality of substrate-feeding transport rolls 26 are arranged in line in the substrate W transport direction in front of and in the opposite side of the backup roll 24 in the substrate W transport direction. ing. Then, the substrate W is transported at a constant speed by the transport roll 22 that is rotationally driven, and when the front end of the substrate W approaches the backup roll 24 and reaches a predetermined coating start position, the coating liquid supply unit 10 descends. Applicator roll 1
The peripheral surface of 2 contacts the surface of the substrate W, and the substrate W and the applicator roll 12 are moved by the backup roll 24.
Is conveyed forward through the gap between the applicator roll 1 and
It is sent out from a gap between the backup roll 24 and the backup roll 24 and conveyed at a constant speed. The coating liquid supply unit 1
When the trailing edge of the substrate W reaches the uppermost point of the backup roll 24 and reaches a predetermined coating end position, 0 rises and moves to the standby position. Then, in the process in which the substrate W is conveyed in this manner, the substrate W makes the surface of the backup roll 2 contact the applicator roll 12 and the backup roll 2
The resist liquid transferred to the peripheral surface of the applicator roll 12 and adhered in a film shape as described above while passing through the gap between the peripheral surface of the applicator roll 12 and the surface of the substrate W After the transfer, a resist film having a predetermined film thickness is formed on the surface of the substrate W.

The surface layers of the backup roll 24, the applicator roll 12, the offset roll 14, the pickup roll 16 and the transport rolls 22 and 26 are made of, for example, a rubber material. Material other than rubber may be used as the material of the peripheral surface. For example, as the transport rolls 22 and 26, a resin material such as polypropylene or a metal material such as stainless steel can be used. However, when the substrate W is inserted into the gap between the applicator roll 12 and the backup roll 24, the substrate W moves from the applicator roll 12 rotating in the opposite direction to the direction opposite to the substrate transport direction. Since a force is received, a relatively large frictional force is generated between the back surface of the substrate W and the peripheral surface of the backup roll 24 in order to convey the substrate W at the peripheral speed of the backup roll 24 against the force. Since it is necessary, it is preferable that the surface layer of the backup roll 24 is made of rubber.

The structure described above is not particularly different from the conventional reverse coating type roll coater,
In this roll coater, the substrate feed transport roll 22
Alternatively, both the substrate feeding transport roll 22 and the substrate feeding transport roll 26 are free rolls.
2 and 3 show examples of the configuration of the transport rolls.

As an example of the substrate feeding carrier roll 22 and the substrate feeding carrier roll 26, a carrier roll 30 shown in a longitudinal sectional view in FIG. 2 has a cylindrical support member 32 and a surface layer member 34 made of a rubber material on the outer peripheral surface thereof. To cover the support member 3
Bearings 36 are attached to both ends of the inner peripheral surface 2 of the bearing 2. The transport roll 30 is inserted into a rotary shaft 40 rotatably supported by a bearing 38, and is rotatably supported by the rotary shaft 40 via a bearing 36. When the rotary shaft 40 is rotated by the driving force transmitted from a drive motor (not shown) via a gear or the like, the transport roll 30 rotates together with the rotary shaft 40 due to the frictional force between the rotary shaft 40 and the bearing 36. Transfer the substrate. On the other hand, with respect to the transport roll 30, the rotating shaft 40 and the bearing 36
When an external force larger than the frictional force with respect to is applied, that is, when a force is applied from the backup roll 24 or the like via the substrate W, the rotational force is transmitted to the transfer roll 30 even if the rotating shaft 40 is rotating. Instead, the transport roll 30 idles as the substrate W moves due to the frictional force between the back surface of the substrate and the surface layer member 34. The transport roll 30 can be used for both substrate feeding and substrate feeding regardless of the speed of the backup roll 24.

A conveying roll 42 whose longitudinal sectional view is shown in FIG.
2 uses a one-way clutch instead of the bearing 36 in the transport roll 30 shown in FIG. 2, and the other configurations are the same as those shown in FIG. That is, in the transport roll 42, the outer surface of the cylindrical support member 44 is covered with the surface layer member 46 made of a rubber material.
One-way clutches 48 are attached to both ends on the inner peripheral surface side of each of the one-way clutches 48, and the one-way clutches 48 are inserted into a rotary shaft 40 rotatably supported by bearings 38.
It is rotatably supported by the rotary shaft 40 via. The transport rolls 42 can be used as the transport rolls 22 and 26 when the backup roll 24 is faster than the transport rolls 22 and 26, for example, and the operation is similar to that of the transport roll 30 shown in FIG.

Next, the roll coater, a part of the schematic structure of which is shown in FIG. 4, is characterized by the arrangement of a plurality of carrier rolls for feeding the substrate. Note that, in FIG. 4, only the applicator roll 50, the backup roll 52, and the transport roll 54 for feeding the substrate are shown, and the transport roll for feeding the substrate is the same as that shown in FIG. Is omitted.

Each transport roll 5 in this roll coater
4 also has the configuration as shown in FIG. 2 or FIG. 3, respectively, and the plurality of transport rolls 54 are arranged so as to become slightly lower in sequence as they come closer to the backup roll 52. The transfer direction of the substrate W is set to be slightly downward with respect to the horizontal direction toward the backup roll 52. The front surface of the back surface of the substrate W transported by the transport roller 54 first comes into contact with the peripheral surface of the backup roller 52, and then the backup roller 52 rotates as the backup roller 52 rotates, as shown by the chain double-dashed line in FIG. Due to the frictional force between the peripheral surface of 52 and the front end of the substrate W, the front end side is lifted and fed forward, and the front end portion of the surface comes into contact with the peripheral surface of the applicator roll 50 that has descended from the upper standby position. In this case, after the front end of the substrate W comes into contact with the peripheral surface of the backup roll 52, the substrate W is
Alternatively, as shown in FIG. 3, the force from the transport roll 54, which is a free roll, is not directly received, and the inertial force generated by the transport of the substrate W by the transport roll 54 is fed by friction with the backup roll 52. It will be conveyed with force applied. Therefore, the driving force of the rotating shaft that rotates the transport roll 54 is applied to the transport roll 54 and the substrate W.
It does not act on the applicator roll 50 via.

Although the coating liquid supply unit 10 is driven up and down between the upper standby position and the lower coating position, any lifting mechanism may be used for this purpose. Instead of moving the unit up and down, the substrate transfer system 20 may be driven up and down. Also,
The configuration of the coating liquid supply unit is not limited to the one including the applicator roll 12, the offset roll 14, the pickup roll 16 and the liquid storage tank 18 as in the illustrated example, but the applicator roll, the pickup roll, and the liquid storage tank. It may be composed of an applicator roll and a doctor roll or a doctor bar, and a liquid storage part may be formed above the contact part of the applicator roll and the doctor roll or the doctor bar. The present invention can be applied to coating liquid supply units having various configurations.

[0023]

According to the roll coater of the first aspect of the present invention, even if there is a difference between the substrate transfer speed by the transfer roll and the substrate transfer speed by the backup roll, the substrate is backed up by the transfer roll. Since the force from the transport roll does not act on the peripheral surface of the applicator roll through the substrate when the film is fed to the position of the roll, there is no fear that the peripheral surface of the applicator roll is damaged by the front end of the substrate. Further, the substrate transported by the transport roll is transported at a constant speed by the backup roll during the period from the contact of the front end of the backup roll with the peripheral face of the backup roll to the separation of the rear end from the peripheral face of the backup roll. There is no unevenness in the coating film formed on the front surface of the substrate or stains or scratches on the back surface of the substrate. Further, since it is not necessary to perform accurate control so that the substrate transport speed by the transport roll and the substrate transport speed by the backup roll are always equal, this roll coater has a simple structure, and No troublesome work such as adjusting the drive device for rolls and backup rolls.

In the roll coater of the invention according to claim 2,
The substrate transported by the transport roll contacts the peripheral surface of the applicator roll after its front end contacts the peripheral surface of the backup roll, and after the front end of the substrate contacts the peripheral surface of the backup roll. Since the substrate is transported by the backup roll without receiving the force from the transport roll, the effect of the invention according to claim 1 is more reliably exhibited.

[Brief description of drawings]

FIG. 1 is a side view showing an example of an embodiment of the present invention and showing a schematic configuration of a roll coater.

FIG. 2 is a vertical cross-sectional view showing a configuration example of a transport roll used in the roll coater according to the present invention.

FIG. 3 is a vertical sectional view showing another example of the configuration of the transport roll.

FIG. 4 is a side view showing another example of the embodiment of the present invention and showing a part of the schematic configuration of the roll coater.

[Explanation of symbols]

 10 coating liquid supply unit 12, 50 applicator roll 20 substrate transport system 22, 26, 30, 42 transport roll 24, 52 backup roll W substrate

Claims (2)

[Claims] 1. A backup roll, which is in contact with the back surface of the substrate and supports the substrate to rotate in the substrate transport direction, and a gap above the backup roll and necessary for the substrate to pass between the backup roll and the backup roll. An applicator roll that is arranged to contact the surface of the substrate and rotates in a direction opposite to the transport direction of the substrate to transfer the coating liquid from the peripheral surface to the surface of the substrate, and the applicator roll and the backup roll, In a roll coater including a transport roll that is provided in a plurality of rows on the front side and the opposite side in the transport direction of the substrate along the transport direction of the substrate, and transports the substrate to the position of the backup roll and sends it from the position, Transfer of the plurality of the applicator rolls and backup rolls arranged in a line at least on the front side in the transfer direction of the substrate. A roll coater characterized in that the roll is a free roll that transmits a rotational force to the substrate when an external force is not applied thereto and idles as the substrate moves when an external force is applied through the substrate. 2. A plurality of transfer rolls arranged in a row on the front side of the applicator roll and the backup roll in the transfer direction of the substrate, wherein the transfer direction of the substrates by them is slightly smaller than the horizontal direction toward the backup roll. The roll coater according to claim 1, wherein the roll coater is arranged so as to face downward, and the front end of the substrate transported by the transport roll contacts the peripheral surface of the backup roll and then contacts the peripheral surface of the applicator roll.