JP2009268946A - Coating device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating device and a method wherein all nozzles required to be plugged are surely plugged to remove foreign substances in the nozzle. <P>SOLUTION: The coating device for discharging a solution from a plurality of nozzles 34 provided with a coating head 22 and applying on a substrate has a plugging means 50 capable of simultaneously plugging the partial nozzles 34 of the coating head 22 and providing a plugging part 50A plugging each nozzle 34 in every nozzles constituting the nozzles 34 of the part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an application apparatus and method for applying a solution by discharging a solution from a plurality of nozzles provided in an application head.

  In a solution coating apparatus equipped with an ink jet type coating head, when the nozzle is clogged due to a dry solidified solution of the solution or foreign matter mixed in the solution, all nozzles of the coating head are fed from the solution supply side. A high discharge pressure is applied to eliminate nozzle clogging.

  However, the clogged nozzle is a part of all nozzles, but the solution flows out of the nozzles without clogging due to the discharge pressure applied to all the nozzles. The solution is wasted. In addition, a nozzle that is not clogged has a better flow of solution than a nozzle that is clogged, so a high discharge pressure cannot be applied to the clogged nozzle, and clogging is fully eliminated. There are things that cannot be done.

Therefore, as described in Patent Document 1, while applying a high discharge pressure to all the nozzles as described in Patent Document 1, the solution flows out only from the nozzles that are clogged among all the nozzles, In order to prevent the solution from flowing out of the nozzles, some of all the nozzles are closed with a closing member.
Japanese Patent Laid-Open No. 10-175313

  However, since the coating apparatus described in Patent Document 1 is configured to collectively block a plurality of nozzles constituting a part of the nozzles closed by the closing member with one protrusion of the closing member. There are the following problems.

  If the parallelism of the protrusions is deviated from the nozzle formation surface of the coating head, even if some of the nozzles that need to be blocked can be blocked, the protrusions for other nozzles There may be a gap between them. When the solution leaks from the gap, a high discharge pressure cannot be applied to the clogged nozzle.

  If the protrusion is made of an elastic material, pressing the protrusion with a strong force against the nozzle forming surface can block all the nozzles where the protrusion needs to be elastically deformed and closed, A pressing device with a strong force is required, which increases the size of the device. Further, there is a possibility that the mounting position of the coating head may be shifted due to the strong force pressing, and it is not preferable to press the protrusion against the nozzle forming surface with a strong force.

  An object of the present invention is to reliably close all the nozzles that need to be closed in order to remove foreign substances in the nozzles in the coating apparatus and method.

  A first aspect of the present invention is a coating apparatus that applies a solution to a substrate by discharging a solution from a plurality of nozzles provided in a coating head, and includes blocking means for simultaneously blocking a part of the nozzles of the coating head. The nozzle includes a closing means having a closing portion for closing each nozzle constituting each nozzle.

  According to a second aspect of the present invention, in the first aspect of the present invention, the blocking means extends over a length range that is at least twice the length of the nozzle row of the coating head, and is cut out at a part of the center of the length range. A window is provided, and a blocking portion arranged so as to correspond to the arrangement of the nozzles is provided in a range excluding the cutout window of the length range.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the closing portion of the closing means is made of an elastic protrusion having a diameter larger than that of each nozzle.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the nozzle further includes a pressurizing unit that discharges the solution at a higher discharge pressure than when the solution is applied to the substrate. It is a thing.

  According to a fifth aspect of the present invention, in a coating method in which a solution is discharged from a plurality of nozzles provided in a coating head and applied to a substrate, a part of the nozzles of the coating head are simultaneously closed and the part of the nozzles is configured. Each nozzle is closed for each nozzle, and the solution is discharged from the nozzle at a higher discharge pressure than when the solution is applied to the substrate, thereby removing foreign matter in the nozzle.

(Claim 1)
(a) The coating device includes a closing unit that simultaneously closes some of the nozzles of the coating head, and includes a closing unit that closes each nozzle constituting each of the nozzles. It was a thing. The blocking means blocks each nozzle that needs to be blocked other than the nozzle in which ejection abnormality is recognized and the nozzles adjacent to the nozzle, and reliably blocks all the nozzles that need to be blocked. Can be blocked.

(Claim 2)
(b) The closing means is provided with a notch window at a part of the center of the length range over the length range of twice or more the length of the nozzle row of the coating head, and excludes the notch window of the length range. The range includes a blocking portion arranged to correspond to the arrangement of the nozzles. If the notch window of the closing means is moved from one end side to the other end side along the nozzle arrangement direction of the coating head according to the arrangement pitch of adjacent nozzles, the corresponding one of all nozzles on the nozzle forming surface of the coating head Some nozzles entering the notch window can be selectively taken into the notch window. Therefore, by using a single closing means, for all nozzles along the nozzle arrangement direction of the coating head, the nozzles that enter the notch window are not closed, and the other nozzles are closed by the closing portion. Can be occluded.

(Claim 3)
(c) Since the closing portion of the closing means is made of an elastic protrusion having a larger diameter than each nozzle, each nozzle can be easily closed by each closing portion.

(Claims 4 and 5)
(d) A part of the nozzles of the coating head are simultaneously closed, and each nozzle constituting the part of the nozzles is closed for each nozzle, and higher than when the solution is applied from the nozzle to the substrate. The foreign matter in the nozzle can be removed by discharging the solution at the discharge pressure. As a result, the solution is pumped only to the nozzle in which the ejection abnormality is recognized and the nozzle adjacent to the nozzle, and the clogging of the nozzle can be solved without wasteful consumption of the solution.

  1 is a front view showing a coating apparatus, FIG. 2 is a side view of FIG. 1, FIG. 3 is a sectional view showing a coating head, FIG. 4 is a plan view showing a nozzle forming surface of the coating head, and FIG. 6 is a plan view of FIG. 5, FIG. 7 is a schematic perspective view showing the coating head and the closing means, and FIG. 8 is a cross-sectional view showing the coating head and the closing means.

  The coating apparatus according to the present invention shown in FIGS. 1 and 2 has a rectangular parallelepiped base 1. Legs 2 are provided at predetermined positions on the lower surface of the base 1, and the base 1 is horizontally supported by the legs 2.

  As shown in FIG. 2, attachment plates 3 having a predetermined width dimension are provided along the longitudinal direction at both ends in the width direction of the upper surface of the base 1. Guide members 4 are respectively provided along the longitudinal direction at one end in the width direction of the upper surfaces of the mounting plates 3. On the upper surfaces of these guide members 4, a rectangular plate-shaped X table 5 is slidably engaged with a pair of first receiving members 6 having substantially U-shaped cross sections provided in parallel on both sides of the lower surface in the width direction. It is supported together. On the upper surface of the X table 5, a mounting table 7 smaller than the X table 5 is provided. That is, the mounting table 7 is movable in the X direction along the guide member 4 via the X table 5.

  The guide member 4 is provided with a stator, the first receiving member 6 is provided with a mover, and the stator and the mover form a linear motor 8 serving as a driving means.

  For example, a glass substrate W used in an active matrix liquid crystal display device is supplied to the mounting table 7. The substrate W is sucked and held on the mounting table 7 by means such as vacuum suction or electrostatic suction. Accordingly, the substrate W held on the mounting table 7 is driven in the X direction by the X table 5.

  A gate-shaped support 11 is erected in the middle of the base 1 in the longitudinal direction so as to straddle the pair of guide members 4. A mounting member 12 made of a prism is horizontally installed on both sides of the support 11.

  A head table 19 is provided on the attachment member 12 so as to be movable along a Y direction (indicated by an arrow in FIG. 2) perpendicular to the X direction which is the driving direction of the X table 5. A first Y drive source 21 composed of a pulse motor is provided on one side of the support 11 in the width direction. The Y drive source 21 drives the head table 19 along the Y direction. The head table 19 may be driven in the Y direction by a linear motor instead of the pulse motor.

  On one side of the head table 19, a plurality of coating heads 22 that are functional thin films by an ink jet method, for example, eject a solution for forming an alignment film (polyimide solution) in a dot shape are arranged along the Y direction. . In this embodiment, for example, seven coating heads 22 are arranged in two rows in a staggered manner.

  As shown in FIGS. 3 and 4, each coating head 22 includes a head body 28. The head main body 28 is formed in a cylindrical shape, and its lower surface opening is closed by a flexible plate 29. The flexible plate 29 is covered with a nozzle plate 31, and a plurality of liquid chambers 32 are formed between the nozzle plate 31 and the flexible plate 29.

  Each liquid chamber 32 communicates with a main pipe line 31A formed in the nozzle plate 31 via a branch pipe line 31B, and a solution is transferred from the main pipe line 31A via the branch pipe line 31B to each liquid chamber 32. Supplied. One end of the main pipeline 31A is connected to a liquid supply hole 33 described later, and the other end is connected to a recovery hole 37 described later.

  The liquid supply hole 33 communicating with the liquid chamber 32 is formed at one longitudinal end of the head body 28. The solution for forming a functional thin film is supplied from the liquid supply hole 33 to the liquid chambers 32. Thereby, the inside of the liquid chamber 32 is filled with the solution.

  A solution supply container 39 constituting a supply source for supplying a solution is connected to the liquid supply hole 33 via a liquid supply pipe 33 </ b> A, and the solution is supplied from the solution supply container 39. Note that a pump for supplying a pressurized gas such as a pressurized nitrogen gas or a pressurizing means 38 such as a pressure tank is connected to the solution supply container 39 via a supply pipe 33C provided with an on-off valve 33B.

  As shown in FIG. 4, the nozzle plate 31 is provided with a plurality of nozzles 34 in a zigzag pattern in two rows along the Y direction, which is a direction orthogonal to the transport direction of the substrate W. Each nozzle 34 communicates with each liquid chamber 32. On the upper surface of the flexible plate 29, as shown in FIG. 3, a plurality of piezoelectric elements 35 are provided as driving means so as to face the nozzles 34.

  Each piezoelectric element 35 is supplied with a driving voltage by a driving unit 36 provided in the head main body 28. As a result, the piezoelectric element 35 expands and contracts, and the flexible plate 29 is partially deformed. As a result, a discharge pressure is generated, and the solution is discharged in the form of dots from the nozzle 34 positioned opposite to the piezoelectric element 35 to be conveyed. It is applied to the upper surface of the substrate W to be applied. Therefore, a coating pattern in which dot-like solutions are arranged in a matrix is formed on the upper surface of the substrate W. And this application | coating pattern adheres and it becomes one film | membrane because each dot-like solution flows and spreads wet.

  The recovery hole 37 communicating with the liquid chamber 32 is formed at the other longitudinal end of the head body 28. The solution supplied from the liquid supply hole 33 to the liquid chamber 32 can be recovered from the recovery hole 37. That is, each head 22 can not only discharge the solution supplied to the liquid chamber 32 from the nozzle 34 but also recover the solution from the recovery hole 37 through the liquid chamber 32.

  As shown in FIG. 1, a detection device 41 for imaging a solution discharged from the nozzle 34 of the coating head 22 is provided at one end of the guide member 4. The detection device 41 has a first movable member 42. The first movable member 42 is provided with a pair of second receiving members 43 (only one is shown) at both ends of the lower surface in the width direction. The receiving members 43 are slidably engaged with the guide member 4. Is provided. When the solution discharged from the nozzle 34 is not measured, as shown in FIG. 1, it waits at a standby position at one end in the longitudinal direction of the guide member 4, that is, a position that does not interfere with the reciprocation of the mounting table 7. Yes.

  The first movable member 42 can be driven in the X direction along the guide member 4 by the linear motor 8, and the mounting table 7 provided on the guide member 4 and the first movable member 42 are connected to each other. It can be selectively driven.

  On the upper surface of the first movable member 42, a second movable member 45 movable along the longitudinal direction of the first movable member 42 has a longitudinal direction orthogonal to the first movable member 42. Is provided.

  As shown in FIGS. 5 and 6, a second Y drive source 46 formed of a pulse motor is provided at one end in the longitudinal direction of the first movable member 42, and the second Y drive source 46 provides the second Y drive source 46. The movable member 45 can be driven along the Y direction intersecting with the X direction, that is, along the direction in which the coating heads 22 are juxtaposed.

  A high-speed camera 48 is provided at one end in the longitudinal direction of the second movable member 45 along the X direction, and a light source 49 that emits illumination light toward the high-speed camera 48 is provided at the other end. . The high-speed camera 48 and the light source 49 constitute detection means.

  A solution is ejected from the nozzle 34 of the predetermined coating head 22 and illumination light is emitted from the light source 49 so that the high-speed camera 48 images the solution before being ejected from the nozzle 34 and reaching the substrate W. It has become.

  The high-speed camera 48 that images the solution outputs the image signal to the image processing apparatus. The image processing apparatus processes the imaging signal from the high-speed camera 48 and outputs the solution discharge state of the nozzle 34 by the imaging signal.

  Incidentally, on the upper surface of the central portion in the longitudinal direction of the second movable member 45, the blocking means 50 for closing a part of the plurality of nozzles 34 of each coating head 22, and the solution discharged from these nozzles 34 are provided. A receiving tray 60 is provided.

  That is, in the coating device, the detection device 41 is used to detect the solution discharge state of the nozzles 34 of the coating heads 22 at every fixed movable timing, and the nozzles 34 in which defective discharge (clogging) occurs. The presence / absence is detected, and if there is a nozzle 34 in which ejection failure has occurred, the position thereof is detected.

  If any of the coating heads 22 has a nozzle 34 that has caused a discharge failure, the nozzle 34 other than the nozzle 34 is closed using the closing means 50 as will be described later, and the collection hole 37 of the coating head 22 is closed. With the open / close valve 37B of the recovery pipe 37A closed, the open / close valve 33B is opened and nitrogen gas pressurized from the pressurizing means 38 is supplied into the solution supply container 39 to supply liquid into the liquid supply hole 33. Pump solution to tube 33A. At this time, the pressure of the pressurized gas supplied from the pressurizing means 38 is applied to all the nozzles 34 at a discharge pressure sufficiently higher than the discharge pressure applied by the piezoelectric element 35 when the solution is applied to the substrate W. Set to the size to be. Thereby, the pressurized solution is discharged from the nozzle 34 that is not blocked by the closing means 50, and the clogging of the nozzle 34 is eliminated.

Hereinafter, the configuration of the closing means 50 will be described.
The closing means 50 closes a part of the nozzles 34 of all the nozzles 34 of each coating head 22 at the same time, and a plurality of the nozzles 34 constituting each part of the nozzles 34 are closed for each nozzle. The closed portions 50A are provided.

  As shown in FIGS. 7 and 8, the closing means 50 has a closing plate 52 supported by an elevating device 51 made of an air cylinder or the like provided on the upper surface of the second movable member 45 so as to be movable up and down. The blocking plate 52 has a rectangular shape having a length over a length range of twice or more the length of the nozzles 34 arranged on the nozzle plate 31 of the coating head 22, and a part of the center of the length range. A notch window 53 is provided in the area, and a plurality of closed portions 50A are arranged in a range excluding the notch window 53 of the length range so as to correspond to the arrangement of the nozzles 34. The nozzle 34 taken into the cutout window 53 is not closed by the closing portion 50A, and the solution fed from the solution supply container 39 is discharged. The plurality of closing portions 50A provided on the closing plate 52 of the closing means 50 include elastic protrusions 54 made of an elastic material such as silicon rubber having a hemispherical diameter larger than the hole diameter of each nozzle 34.

  In the closing means 50 of this embodiment, the closing plate 52 is provided with three rows of closing portions 50A (elastic protrusions 54). On the other hand, as described above, the coating head 22 is provided with two rows of nozzles 34 on the nozzle forming surface of the nozzle plate 31, and the first row of nozzles 34 and the second row of nozzles 34 have an arrangement pitch in the nozzle arrangement direction. Are arranged so as to form a staggered pattern shifted by 1/2 pitch. According to the staggered arrangement of the nozzles 34 in two rows in the coating head 22, the closing means 50 corresponds to the first row and third row blocking portions 50 </ b> A (elastic protrusions 54). The elastic protrusions 54) are provided in the arrangement direction so as to be shifted by 1/2 of the arrangement pitch. There are two rows of the nozzles 34 of the coating head 22, but there are three rows of the blocking portions 50 </ b> A (elastic protrusions 54) of the blocking means 50 except for some nozzles 34 in the second row of the coating head 22. When the other nozzles 34 are closed, the first row of the blocking portions 50A (elastic protrusions 54) and the second row of the blocking portions 50A (elastic protrusions 54) of the closing means 50 are used for closing. When closing the other nozzles 34 except for some of the nozzles 34 in the first row, the closing portion 50A (elastic protrusion 54) in the second row and the closing portion 50A (elastic protrusion 54) in the third row of the closing means 50 are used. ) Is used for occlusion.

  In the closing means 50 of this embodiment, the window size of the cutout windows 53 is set to a size that takes in the nozzles 34 for one row of the nozzles 34 in the two rows of the coating head 22. Accordingly, the solution pumped from the solution supply container 39 is discharged from the three nozzles 34.

  Therefore, the clogging generated in the nozzle 34 of each coating head 22 in the coating apparatus is eliminated as follows.

  In the following operations (1) to (4), after the application of the solution to the substrate W supplied on the mounting table 7 is completed, the substrate W on which the application of the solution is completed is unloaded, and then the solution When the substrate W to be coated is carried in, the placement table 7 may be carried out in a state where it is stopped at the carry-in / out position at the left end of the base 1 shown in FIG.

  (1) The detection device 41 is positioned below the nozzle plate 31 of each coating head 22 by the first movable member 42 and the second movable member 45, and the solution is discharged from the nozzle 34 of the coating head 22. The solution discharge state of the nozzle 34 is detected by the camera 48, and the defective discharge nozzle 34 is detected.

  At this time, since the number of nozzles 34 that can detect the discharge state with one camera 48 is limited, the nozzles 34 of the seven coating heads 7 are divided into groups for each number that can detect the discharge state with one camera 48. The solution discharge state of the nozzle 34 is detected for each group while the camera 48 is moved intermittently in the Y direction.

  (2) The closing means 50 is positioned below the nozzle plate 31 of the coating head 22 in which the defective ejection nozzle 34 is generated by the first movable member 42 and the second movable member 45. More specifically, the first movable member 42 and the second movable member 45 are moved so that the ejection failure nozzle 34 faces the center of the cutout window 53 of the closing plate 52. The closing plate 52 is lifted by the lifting / lowering device 51 of the closing means 50 of the closing means 50, and the closing portion 50 </ b> A (elastic protrusion 54) of the closing means 50 is pressed against the nozzles 34 other than the ejection failure nozzles 34 so that the nozzles 34 are moved. The nozzles 34 are closed and the ejection failure nozzle 34 is taken into the cutout window 53.

  (3) With the recovery hole 37 of the coating head 22 closed, the solution is pumped from the solution supply container 39 to apply a discharge pressure higher than the discharge pressure applied by the piezoelectric element 35 to all the nozzles 34, thereby blocking. The pressurized solution is discharged from the nozzle 34 that is not blocked by the means 50, and the clogging of the nozzle 34 is eliminated.

  (4) The clogging means 50 is closed by the first movable member 42 and the second movable member 45 when the clogging removing operation (2) and (3) described above for all the defective ejection nozzles 34 of the coating head 22 is completed. Is retracted from below the coating head 22. The nozzle forming surface of the nozzle plate 31 of the coating head 22 is wiped with a blade of a wiping device (not shown).

  After the operation (4) is completed, the operation (1) is performed again for all nozzles 34 or nozzles 34 in which ejection failure has occurred to eliminate clogging of the defective ejection nozzle 34. You may make it confirm. Here, if the clogging has not yet been resolved, perform the clogging removal work described in (2) and (3) above again, or send a message to the display device such as a monitor to notify the operator to that effect. It may be done through an alarm by an alarm such as a display or a buzzer.

  Further, when the defective ejection nozzle 34 is not detected as a result of the detection in (1), it is not necessary to perform the operations (2) to (4).

According to the present embodiment, the following operational effects can be obtained.
(a) The coating apparatus is a closing means 50 that simultaneously closes some of the nozzles 34 of the coating head 22, and each nozzle 34 constituting each of the nozzles 34 is provided for each nozzle. It has what has the obstruction | occlusion means 50 provided with the obstruction | occlusion part 50A obstructed in the. The closing means 50 is configured such that each closing portion 50A independently elastically deforms each nozzle 34 that needs to be closed other than the nozzle 34 in which ejection abnormality is recognized and the adjacent nozzle 34. Since each block 34 is blocked, all the nozzles 34 that need to be blocked by the individual blocking portions 50A can be reliably closed without being influenced by the blocking state of the other blocking portions 50A. Therefore, ejection abnormalities such as clogging of the nozzles 34 can be effectively eliminated.

  (b) The closing means 50 is provided with a notch window 53 at a part of the center of the length range over a length range of twice or more the length of the nozzle row of the coating head 22, In a range excluding the window 53, a blocking portion 50A arranged to correspond to the arrangement of the nozzles is provided. If the notch windows 53 of the closing means 50 are moved from one end side to the other end side along the nozzle arrangement direction of the coating head 22 according to the arrangement pitch of the adjacent nozzles 34, all of the nozzle formation surfaces of the coating head 22 can be obtained. A part of the nozzles 34 entering the cutout window 53 among the nozzles 34 can be selectively taken into the cutout window 53. Therefore, by using the single closing means 50, all the nozzles 34 along the arrangement direction of the nozzles of the coating head 22 are not closed for the nozzles 34 that have entered the cutout window 53, and the other nozzles 34 are closed. The portion 50A can be closed as described above (a).

  (c) Since each of the closing portions 50A of the closing means 50 includes the elastic protrusions 54 having a diameter larger than that of each nozzle 34, each nozzle 34 can be easily closed by each closing portion 50A.

  (d) A part of the nozzles 34 of all the nozzles 34 of the coating head 22 are simultaneously closed, and each nozzle 34 constituting the part of the nozzles 34 is closed for each nozzle, and all the nozzles 34 are also closed. A high discharge pressure can be applied to the nozzle 34 to remove foreign substances in the nozzle 34. As a result, the solution can be pumped only to the nozzle 34 in which the ejection abnormality is recognized and the nozzle 34 adjacent thereto, and the clogging of the nozzle 34 can be solved without wasteful consumption of the solution.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration of the present invention is not limited to these embodiments, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

  For example, in the above embodiment, the closing portion 50A is directly fixed on the closing plate 52 as the elastic protrusion 54 of an elastic material, but may be fixed via a spring.

  In addition, the window size of the cutout windows 53 of the closing means 50 is set to the size that takes in the nozzles 34 for three rows, but is not limited to this, and at least one defective discharge that needs to eliminate clogging. Any size may be used as long as the nozzle 34 can be taken in. However, as the number of nozzles 34 that can be taken in increases, the wasteful consumption of the solution increases, and the pressure of the solution acting on the defective ejection nozzle 34 is dispersed. Therefore, it is preferable to make the window size too large. Absent.

FIG. 1 is a front view showing a coating apparatus. FIG. 2 is a side view of FIG. FIG. 3 is a cross-sectional view showing the coating head. FIG. 4 is a plan view showing the nozzle forming surface of the coating head. FIG. 5 is a front view showing the discharge state detecting device and the closing means. 6 is a plan view of FIG. FIG. 7 is a schematic perspective view showing the coating head and the closing means. FIG. 8 is a sectional view showing the coating head and the closing means.

Explanation of symbols

22 coating head 34 nozzle 38 pressurizing means 50 closing means 50A closing part 53 notch window 54 elastic protrusion

Claims (5)

In a coating apparatus that discharges a solution from a plurality of nozzles provided in a coating head and coats the substrate,
A coating means comprising: a closing means for simultaneously closing a part of the nozzles of the coating head, the sealing means having a closing part for closing each of the nozzles constituting the nozzles for each nozzle. apparatus.   The blocking means has a cutout window in a part of the center of the length range over a length range of twice or more the length of the nozzle row of the coating head, and the cutout window of the length range is excluded. The coating apparatus of Claim 1 provided with the obstruction | occlusion part arranged so as to correspond to the arrangement | sequence of the said nozzle.   The coating device according to claim 1 or 2, wherein the closing portion of the closing means is an elastic protrusion having a diameter larger than that of each nozzle.   The coating apparatus according to claim 1, further comprising a pressurizing unit that discharges the solution from the nozzle at a higher discharge pressure than when the solution is applied to the substrate. In a coating method in which a solution is discharged from a plurality of nozzles provided in a coating head and applied to a substrate,
A part of the nozzles of the application head are simultaneously closed, and each nozzle constituting the part of the nozzles is closed for each nozzle, and the discharge pressure is higher than when applying a solution from the nozzle to the substrate. And discharging the solution to remove foreign matter in the nozzle.

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