JP5246857B2 - Coating device - Google Patents

Description

  The present invention relates to a coating apparatus that coats a coating liquid on a substrate placed on a stage.

  2. Description of the Related Art Flat panel displays such as liquid crystal displays and plasma displays are used in which a coating solution such as a resist solution is applied on a substrate made of glass or the like. This coating substrate is formed by a coating apparatus that uniformly coats the coating solution.

  This coating apparatus includes a stage on which the substrate is placed and a coating unit that discharges the coating liquid. By moving the coating unit while discharging the coating liquid from the slit of the coating unit, the coating apparatus is even on the substrate. A coating film having a thickness is formed.

  Such a coating apparatus, as shown in Patent Document 1 below, is to apply the coating unit to a state suitable for the main coating before performing the coating on the substrate (the coating on the substrate is called the main coating). A preliminary coating device for initializing the coating unit is provided. In this preliminary coating device, a roller extending in one direction is rotatably supported, and the roller extending direction and the slit extending direction of the coating unit are arranged in parallel. When initializing the coating unit, the coating liquid is discharged from the slit of the coating unit onto the outer peripheral surface of the roller, and the roller is rotated in a state where the discharged coating liquid is attached to the outer peripheral surface of the roller. Thereby, the coating liquid in a slit is discharged over the whole longitudinal direction of a slit, and the coating liquid in the slit of a coating unit is equalized over a longitudinal direction. In this way, initialization of the coating unit is completed.

JP 2005-252045 A

  However, the roller is slightly bent and deformed in the direction of gravity due to its own weight. Specifically, since the roller is supported at both ends, the center portion in the longitudinal direction of the roller is bent and deformed downward in the gravitational direction as compared with the both ends due to its own weight. Therefore, when the application unit is initialized, if the application liquid is discharged from the slit, the contact state between the application liquid and the outer peripheral surface of the roller does not become uniform in the longitudinal direction of the roller, so that sufficient initialization cannot be performed. There is a problem. That is, the central portion of the roller in the longitudinal direction has a slightly larger amount of bending deformation downward in the gravitational direction than both ends, so that the applied liquid is thin at the central portion of the slit and may be interrupted in some cases. Sometimes. In such a case, even if the roller is rotated, the coating liquid in the central portion of the slit is not discharged in accordance with the rotation of the roller. The amount discharged is different depending on the rotation of the roller. As a result, there has been a problem that the coating liquid in the slit is not uniform in the longitudinal direction and sufficient initialization cannot be performed. In particular, in recent years, the roller length has become longer due to the use of a large substrate, and this problem has become more prominent.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a coating apparatus capable of sufficiently initializing the coating unit even when the roller is bent and deformed. .

  In order to solve the above problems, a coating apparatus of the present invention includes a stage on which a substrate is placed, a coating unit having a slit that extends in one direction and discharges a coating liquid, and a preliminary coating apparatus that initializes the coating unit. The coating unit initialized by the preliminary coating apparatus is a coating apparatus that applies the coating liquid to the substrate by discharging the coating liquid from the slit while moving relative to the substrate on the stage. The preliminary coating apparatus has a roller that extends in one direction and adheres the coating liquid discharged from the slit. The roller extends in the direction in which the roller extends and the slit extends (when the slit is discharged). It is characterized by being arranged in a state where the directions intersect.

  According to the coating apparatus, the difference between the slit in the gravity direction between the slit and the roller can be reduced between the longitudinal central portion and both ends of the slit, so that even when the roller is deformed and deformed. The coating unit can be sufficiently initialized. That is, since the center part of the roller is deformed downward in the gravitational direction due to bending, when the slit is positioned on the axis of the roller, the dimension in the gravitational direction between the outer peripheral surface of the roller and the slit is Large at the center in the longitudinal direction and small at both ends. On the other hand, at a position slightly displaced in the direction perpendicular to the axial direction from the axis of the roller, the outer peripheral surface of the roller is located on the lower side in the gravitational direction than on the axis of the roller. Therefore, if the roller is arranged so that the direction in which the roller extends and the direction in which the slit extends intersect the slit in a state where the longitudinal center position of the slit is located on the axis of the roller, The central position in the direction faces the outer peripheral surface on the roller shaft, and both longitudinal ends of the slit face the outer peripheral surface slightly displaced from the roller shaft. That is, the difference between the outer peripheral surface of the roller and the slit in the direction of gravity is small between the central portion and both ends of the slit. Accordingly, the slit can be brought close to the roller in the longitudinal direction, and the coating liquid in the slit is longitudinally rotated by rotating the roller with the coating liquid from the slit adhered to the outer peripheral surface of the roller. It is discharged over the direction, and the coating unit can be sufficiently initialized.

  In addition, the preliminary coating apparatus has a case portion that accommodates the roller, and the case portion is configured to rotate about a center point in the longitudinal direction of the roller. The roller may be displaced by being moved so that the direction in which the roller extends and the direction in which the slit extends can be adjusted to intersect.

  According to this configuration, since the displacement amount of the roller can be adjusted by rotating the case portion, the device configuration can be simplified as compared with the configuration in which only the roller 4 is displaced. Therefore, the setting and adjustment of the preliminary coating apparatus can be simplified.

  According to the coating apparatus of the present invention, the coating unit can be sufficiently initialized even when the roller is bent and deformed.

  An embodiment according to the coating apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram schematically illustrating a coating apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram schematically illustrating a main part of a coating unit.

  As shown in FIGS. 1 to 2, the coating apparatus 1 forms a coating film by applying a coating solution such as a chemical solution or a resist solution on a substrate 10, and mounts a base 20 and the substrate 10. And a pre-coating device 2 (left side in FIG. 1) for initializing the coating unit 30. I have.

  In the following description, the direction in which the coating unit 30 moves is described as the X-axis direction, the direction orthogonal to this in the horizontal plane is defined as the Y-axis direction, and the direction orthogonal to both the X-axis and Y-axis directions is described as the Z-axis direction. To proceed.

  The stage 21 is for placing and holding the loaded substrate 10 on its surface. The stage 21 is formed with a plurality of suction holes (not shown) opened on the surface thereof, and these suction holes and a vacuum pump (not shown) are connected in communication. When the vacuum pump is operated while the substrate 10 is placed on the surface of the stage 21, a suction force is generated in the suction hole so that the substrate 10 is sucked to the surface of the stage 21 so that the substrate 10 can be sucked and held. It has become. The stage 21 is provided with a substrate lifting mechanism that moves the substrate 10 up and down. That is, a plurality of pin holes (not shown) are formed on the surface of the stage 21, and lift pins (not shown) that can be moved up and down in the Z-axis direction are embedded in the pin holes. Then, by lifting the lift pins with the substrate 10 placed on the surface of the stage 21, the tip end portion of the lift pins comes into contact with the substrate 10, and the substrate 10 is held at a predetermined height position by the tip portions of the plurality of lift pins. It can be done. Thereby, a contact part with the board | substrate 10 can be hold | suppressed as much as possible, and it can replace | exchange smoothly, without damaging the board | substrate 10. FIG.

  The coating unit 30 is for applying a coating solution on the substrate 10. The coating unit 30 has a leg portion 31 (see FIG. 2) attached to the base 20 and a base portion 34 extending in the Y-axis direction, and straddles the base 20 in the Y-axis direction. It is attached to be movable in the X-axis direction. Specifically, rails 22 extending in the X-axis direction are installed at both ends of the base 20 in the Y-axis direction, and leg portions 31 are slidably attached to the rails 22. The leg 31 is provided with a mover of a linear motor 33. By controlling the driving of the linear motor 33, the coating unit 30 moves in the X-axis direction and can be stopped at an arbitrary position. Yes.

  In this embodiment, it moves to the preliminary application position where preliminary application is performed and the main application start position where main application is performed, and can be stopped accurately at each position. Here, the preliminary application position is a position where preliminary application is performed in order to initialize the application unit, and the position of a slit 34a of the application unit 30 described later coincides with the axial position of the roller 4 in the X-axis direction. This is the position (position A in FIG. 1). The main application position is a position (position B in FIG. 1) at which application is started on the substrate 10 in the X-axis direction.

  As shown in FIG. 2, a base 34 for applying the coating liquid is attached to the leg portion 31 of the coating unit 30. Specifically, the leg portion 31 is provided with a rail 37 extending in the Z-axis direction and a slider 35 that slides along the rail 37, and the slider 35 and the base portion 34 are connected to each other. . A ball screw mechanism that is driven by a servo motor (not shown) is attached to the slider 35. By controlling the servo motor, the slider 35 moves in the Z-axis direction, and at any position. Can be stopped. That is, the base 34 is supported so as to be able to contact and separate from the substrate 10 held on the stage 21 or the roller 4 of the preliminary coating apparatus 2.

  The base 34 forms a coating film on the substrate 10 by applying a coating solution. The base part 34 is a columnar member having a shape extending in one direction, and is provided so as to be substantially orthogonal to the traveling direction (X-axis direction) of the coating unit 30. A slit 34 a extending in the longitudinal direction is formed in the base part 34, and the coating liquid supplied to the base part 34 is uniformly discharged from the slit 34 a in the longitudinal direction. Accordingly, by running the coating unit 30 in the X-axis direction with the coating liquid being discharged from the slit 34a, a coating film having a constant thickness is formed on the substrate 10 over the longitudinal direction of the slit 34a. It has become.

  A preliminary coating device 2 is provided at the end of the coating device 1 in the X-axis direction (left side in FIG. 1). This preliminary coating apparatus 2 initializes the coating unit 30. The preliminary coating apparatus 2 includes a case portion 24 that receives the coating liquid discharged from the coating unit 30, and a roller 4 that is rotatably accommodated in the case portion 24. By discharging the coating liquid from the unit 30, the coating unit 30 can be initialized.

  The case part 24 is attached to the base 20, and a part of the case part 24 is embedded in a state of protruding on the surface of the base 20. An opening 26 a is formed above the case portion 24, and a part of the roller outer peripheral surface 41 can face the longitudinal direction from the opening 26 a. Therefore, when the coating unit 30 stops at the preliminary coating position (position A), the slit 34a of the coating unit 30 and the roller outer peripheral surface 41 are opposed to each other.

  A cleaning machine 5 for cleaning the coating liquid and the like attached to the roller 4 is attached to the case portion 24. The cleaning machine 5 includes a cleaning liquid supplier 50, a scraper 60, and a gas nozzle 70, and is attached in this order along the rotation direction of the roller 4 in the vicinity of the roller outer peripheral surface 41. The cleaning liquid supplier 50 discharges the cleaning liquid onto the roller outer peripheral surface 41. The scraper 60 scrapes off the coating liquid adhering to the roller outer peripheral surface 41 by contacting the roller outer peripheral surface 41. The gas nozzle 70 is for drying the roller outer peripheral surface 41 by blowing air, inert gas or the like (hereinafter simply referred to as gas) to the roller outer peripheral surface 41. That is, the roller outer peripheral surface 41 is cleaned by these, and the roller outer peripheral surface 41 after cleaning appears from the opening 26a.

  A discharge port 25a is provided at the bottom of the case portion 24, and the discharge port 25a and the waste liquid recovery device are connected by a pipe. Thereby, the waste liquid in the case part 24 is discharged | emitted to a waste liquid collection | recovery apparatus through this discharge port 25a. A gas suction port 25 b is provided on the side surface of the case portion 24. As a result, the gas supplied from the gas nozzle 70 to the roller 4, the volatile component of the cleaning liquid, and the like are sucked and recovered by the gas recovery device connected to the gas suction port 25b through the gas suction port 25b. Yes.

  In the case portion 24, a roller 4 extending in a uniaxial direction is provided so as to be rotatable around the axis. Specifically, a motor (not shown) is connected to the roller 4, and the roller 4 can be rotated around the axis (in the direction of the arrow in FIG. 1) by driving the motor. As a result, the coating liquid discharged from the coating unit 30 is attached to the roller outer peripheral surface 41. By rotating the roller 4 in this state, the coating liquid attached to the outer peripheral surface 41 is drawn in according to the rotation of the roller 4, and the slit A predetermined amount of coating solution is removed along the longitudinal direction of 34a.

  The roller 4 is arranged in a state in which the extending direction (axial center direction) intersects the extending direction of the slit 34a. Here, FIG. 3 is a diagram schematically showing the base portion 34 and the roller 4 of the coating unit 30. 3A is a view showing a state in which the coating unit 30 is arranged at a position other than the preliminary coating position (position A, see FIG. 1), and FIG. 3B is a diagram illustrating the coating unit 30 in the preliminary coating position. It is a figure which shows the state arrange | positioned at (position A). A roller 4 'indicated by a broken line indicates a state in which the direction in which the roller 4 extends (axial center direction) and the direction in which the slit 34a extends are arranged in parallel (arranged so as to coincide with each other). In this embodiment, the arrangement posture of the roller 4 ′ is referred to as a reference posture of the roller 4.

  As shown in FIG. 3, the roller 4 is arranged so as to intersect the slit 34a, and both axial ends 4a and 4b of the roller 4 are displaced in the X-axis direction by ΔX with respect to the reference posture. Is arranged in. Specifically, the roller 4 is configured such that the axial end 4a is + ΔX in the X-axis direction and the axial end from a state in which the longitudinal center point M of the roller 4 and the longitudinal center point N of the slit 34a coincide with each other. 4b is arranged in a state displaced by −ΔX in the X-axis direction. Then, as shown in FIG. 3B, when the center point M of the roller 4 and the center point N of the slit 34a coincide, the roller outer peripheral surface 41 and the slit 34a are set to face each other in the longitudinal direction. Thus, the entire slit 34a is in a state where the roller outer peripheral surface 41 is in a region viewed from the Z-axis direction (gravity direction). Thus, when the coating unit 30 ejects the coating liquid from the slit 34a at the preliminary coating position (position A), the ejected coating liquid is coated on the roller outer peripheral surface 41 in the longitudinal direction. .

  The displacement amount ΔX at both ends 4a and 4b in the axial center direction of the roller 4 is such that the gravity direction dimension (Z-axis direction dimension) between the roller 4 and the slit 34a is substantially equal at the longitudinal center portion and both end portions. Is set.

  Here, FIG. 4 is a view showing the positional relationship between the slit 34a of the base portion 34 and the roller 4, FIG. 4 (a) is a view seen from the X-axis direction, and FIG. 4 (b) is the Z-axis direction. It is the figure seen from (above). FIG. 5 is a diagram showing the positional relationship between the roller 4 and the slit 34a when it is assumed that no bending deformation occurs in the roller 4, and is displaced from the reference posture of the roller 4 by the base 34 shown by a broken line. The positional relationship between the roller 4 displaced by the amount ΔX and the slit 34a is shown.

  As shown in FIG. 4, when it is assumed that the roller 4 is not bent and deformed, the Z direction dimension (gravity direction dimension) between the roller 4 and the slit 34a is S. However, in actuality, the central portion 4c in the longitudinal direction of the roller 4 is bent and deformed downward by t from both end portions 4a and 4b. Therefore, the Z direction between the central portion C of the slit 34a and the central portion 4c of the roller 4 is deformed. The dimension is S + t.

  Further, when both end portions 4a and 4b of the roller 4 are displaced by a displacement amount ΔX from the reference posture of the roller 4 (broken line in FIG. 5), the Z-direction dimension is a position P on the axis of the roller 4. As compared with the above, it becomes larger by the gap ΔZ. That is, the dimension in the Z direction between the end 4a (4b) of the roller 4 and the end R (L) of the slit 34a is S + ΔZ.

  Therefore, if the deflection deformation amount t of the central portion 4c of the roller 4 and the gap ΔZ between the both end portions L and R are the same, the Z-direction dimension of the roller outer peripheral surface 41 and the slit 34a is almost the same in the longitudinal direction. Can be equal. That is, if the displacement amount ΔX at both ends 4a and 4b of the roller 4 is set so that the bending deformation amount t and the gap ΔZ have the same value, the Z-direction dimension between the roller outer peripheral surface 41 and the slit 34a is the longitudinal direction. Can be made approximately equal over time.

  Specifically, the relationship between the displacement amount ΔX and the gap ΔZ can be calculated geometrically by the following equation. The center angle Δθ and the radius R of the roller 4 are set as shown in FIG.

Δθ = sin ⁻¹ (ΔX / R) (1)
ΔZ = ΔX · tan (Δθ / 2) (2)
In the present embodiment, the relationship between the displacement amount ΔX and the gap ΔZ calculated as the radius R of the roller 4 = 130 (mm) is shown in FIG. According to FIG. 7, for example, when both ends of the roller 4 are displaced by ΔX = 2 (mm), ΔZ = 15.4 (μm).

  Here, in the case where the deformation amount t of the central portion of the roller 4 is t = 25 (μm), if the deformation amount t is equal to the gap ΔZ, the Z direction dimension between the roller outer peripheral surface 41 and the slit 34a is the longitudinal direction. Can be made approximately equal over time. That is, from the graph of FIG. 7, ΔX corresponding to ΔZ = 25 (μm) is ΔX = 2.5 (mm). Therefore, the roller 4 is disposed in a state where both end portions 4 a and 4 b of the roller 4 are displaced by 2.5 (mm) with respect to the reference posture of the roller 4. Thereby, the Z direction dimension of the roller outer peripheral surface 41 and the slit 34a can be made substantially equal over a longitudinal direction.

  Next, the operation of the coating apparatus 1 including the preliminary coating apparatus 2 will be described with reference to the flowcharts shown in FIGS. In the present embodiment, since the roller 4 is disposed in a state where the roller 4 is displaced by a predetermined displacement amount ΔX with respect to the reference posture, the Z-direction dimension of the roller outer peripheral surface 41 and the slit 34a extends in the longitudinal direction. It is set to be almost equal.

  First, the application unit 30 is initialized as a preliminary application process before the main application process of applying the application liquid onto the substrate 10 (step S1). This preliminary application process is performed according to steps S11 to S14 of the flowchart shown in FIG. First, the application unit 30 is positioned (at the time of preliminary application) (step S11). Specifically, the application unit 30 is moved by driving a linear motor, and is stopped when the application unit 30 is positioned at the preliminary application position (position A). Then, the base 34 is lowered by driving the servo motor, and is stopped at a position where the distance between the slit 34a of the base 34 and the roller outer peripheral surface 41 becomes a predetermined value.

  Next, the preliminary coating apparatus 2 is operated (step S12). That is, the roller 4 is rotated in a state where the cleaning liquid is discharged from the cleaning liquid supplier 50 and the gas is ejected from the gas nozzle 70. As a result, the entire roller outer peripheral surface 41 is cleaned, and the outer peripheral surface 41 is formed in a state where it can be preliminarily applied.

  Next, preliminary application is performed (step S13). Specifically, a predetermined amount of coating liquid is discharged from the coating unit 30 onto the rotating roller outer peripheral surface 41. Thereby, the slit 34a of the coating unit 30 and the roller outer peripheral surface 41 are connected with the coating liquid. That is, in this embodiment, since the Z direction dimension of the roller outer peripheral surface 41 and the slit 34a is set to be substantially equal in the longitudinal direction, the slit 34a and the roller outer peripheral surface 41 extend in the longitudinal direction. , And connected with the coating solution. Then, by rotating the roller 4 in this state, a coating film having a certain thickness is formed over the longitudinal direction of the roller outer peripheral surface 41, and after a predetermined amount of coating liquid is discharged, the base 34 is raised. Let Thereby, the coating film formed between the slit 34a and the roller 4 is cut off, and the initialization of the coating unit 30 is completed.

  On the other hand, as shown in FIG. 8, simultaneously with the initialization of the coating unit 30, the substrate 10 is carried in step S2. Specifically, the apparatus is on standby with a plurality of lift pins protruding from the surface of the stage 21, and the substrate 10 is placed on the tip of the lift pins by a robot hand (not shown). Then, from the state where the substrate 10 is placed on the tip portion of the lift pin, the lift pin is lowered and the substrate 10 is placed on the surface of the stage 21.

  Next, the substrate 10 is held on the stage 21 in step S3. Specifically, the suction force is rapidly generated in the suction hole by driving the vacuum pump. That is, when the air in the suction hole is rapidly sucked by the vacuum pump, a suction force is generated in the suction hole, and the substrate 10 is instantaneously sucked and held on the stage 21.

  Next, in step S4, the coating unit 30 is positioned at the main coating position. Specifically, after the preliminary application is completed in step S13, the application unit 30 is moved to the main application position (position B) by driving the linear motor. Then, the base 34 is lowered by driving the servo motor, and is stopped at a position where the distance between the slit 34a of the base 34 and the surface of the substrate 10 becomes a predetermined value.

  Next, in step S5, a coating operation is performed. That is, a coating film is formed on the surface of the substrate 10 by discharging the coating liquid while the coating unit 30 is traveling in a specific direction.

  Next, in step S6, the substrate 10 is taken out. That is, after a coating film is formed on the surface of the substrate 10 by the coating operation in S5, the vacuum pump is stopped and the pressure in the suction hole 21a is returned to atmospheric pressure. Then, by lifting the lift pin, the substrate 10 is held at the tip of the lift pin, the substrate 10 is transferred to a robot hand (not shown), and the substrate 10 is discharged from the surface of the stage 21.

  According to such a coating apparatus 1, the difference between the slit 34 a and the roller 4 in the direction of gravity can be reduced between the central portion 4 c of the roller 4 and the both end portions 4 a and 4 b, and thus the preliminary coating apparatus 2. In this case, the application unit 30 can be sufficiently initialized even if the roller 4 is bent and deformed. As a result, the slit 34a can be brought close to the roller 4 in the longitudinal direction. Therefore, by rotating the roller 4 with the coating liquid from the slit 34a attached to the roller outer peripheral surface 41, the slit 34a is rotated. The coating liquid inside can be discharged almost uniformly over the longitudinal direction, and the coating unit 30 can be sufficiently initialized.

  In the above embodiment, an example in which the roller 4 itself is displaced with respect to the reference posture has been described. However, the roller 4 is displaced with respect to the reference posture by rotating the entire pre-coating device 2. May be. Specifically, a shaft member is provided on the base 20 directly below the center point M of the roller 4, and the shaft member and the case portion 24 of the pre-coating device 2 are connected via a bearing. That is, the case portion 24 rotates about the center point M of the roller 4, and the roller 4 can be displaced with respect to the reference posture about the center point M by rotating the case portion 24. It is like that. Thereby, the displacement amount ΔX of the roller 4 can be adjusted by rotating the case portion 24. Thereby, since the apparatus configuration can be simplified as compared with the configuration in which only the roller 4 is displaced, the setting and adjustment of the preliminary coating apparatus 2 can be simplified.

1 is a front view schematically showing a coating apparatus according to an embodiment of the present invention. It is the schematic which shows the leg part vicinity of the coating unit in the said coating device. It is the figure which showed the nozzle | cap | die part and roller of the coating unit typically, (a) is a figure which shows the state by which the coating unit is arrange | positioned in positions other than a preliminary application position, (b) is a coating unit. It is a figure which shows the state arrange | positioned in a preliminary application position. It is a figure which shows the positional relationship of the slit of a nozzle | cap | die part, and a roller, (a) is the figure seen from the X-axis direction, (b) is the figure seen from the Z-axis direction (above). It is a figure which shows the positional relationship of a roller and a slit at the time of assuming that bending deformation does not generate | occur | produce in a roller. It is a figure for demonstrating the symbol used by Formula (1) and Formula (2). It is a figure which shows the relationship between displacement amount (DELTA) X and gap (DELTA) Z. It is a flowchart which shows operation | movement of a coating device. It is a flowchart which shows operation | movement of a preliminary application apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Application | coating apparatus 2 Preliminary application | coating apparatus 4 Roller 10 Board | substrate 30 Application | coating unit 34 Base part 34a Slit 41 Roller outer peripheral surface

Claims (2)

A coating unit that includes a stage on which a substrate is placed, a coating unit that extends in one direction and discharges a coating liquid, and a preliminary coating device that initializes the coating unit, and is initialized by the preliminary coating device. Is a coating apparatus that applies the coating liquid to the substrate by discharging the coating liquid from the slit while moving relative to the substrate on the stage,
The preliminary coating apparatus has a roller that extends in one direction and adheres the coating liquid discharged from the slit, and the roller is arranged in a state where the direction in which the roller extends and the direction in which the slit extends intersect. An applicator characterized by being made.   The preliminary coating apparatus includes a case portion that accommodates the roller, and the case portion is configured to rotate around a center point in the longitudinal direction of the roller, and the case portion is rotated. The coating apparatus according to claim 1, wherein the roller is displaced so that the extending direction of the roller and the extending direction of the slit can be adjusted to intersect each other.

Images