JP2015199058A - Coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus and a coating method capable of eliminating mixture of bubbles contained in piping, into coating liquid, even when coating a substrate with the coating liquid having comparatively high viscosity, and getting rid of coating defects due to the bubbles.SOLUTION: The coating apparatus includes: a spinneret 3 having a slit 21 at a tip, for discharging coating liquid from the slit 21, to apply the coating liquid to an object W to be coated; a tank 9 for storing the coating liquid; liquid delivery piping 17 being a path through which the coating liquid is delivered from the tank 9 to the spinneret 3; and a sealing member 30 capable of coming in contact with and separating from the spinneret 3, for firmly adhering to the spinneret 3 so as to cover the slit 21 when being in contact with the spinneret 3. The sealing member 30 includes a coating liquid drainage device having: a coating liquid drainage port 33 for draining the coating liquid through the spinneret 3; and a vacuum-pump 43 connected to the coating liquid drainage port 33 through piping 19.

Description

  The present invention relates to a coating apparatus that applies a coating liquid onto a substrate by discharging the coating liquid from a slit formed in a base, and more particularly to a coating apparatus and a coating method that apply a high-viscosity coating liquid.

  As a device for applying a coating solution to a substrate such as a glass substrate or a film, there is known a coating device provided with a die in which a slit for discharging the coating solution is formed (for example, see Patent Document 1). This coating apparatus includes a tank for storing the coating liquid and a pump for supplying the coating liquid in the tank to the slit of the base.

  The slit is formed long along the width direction of the substrate. For example, the coating liquid is discharged onto the surface of the substrate by discharging the coating liquid from the slit while moving the base horizontally with respect to the substrate placed on the stage. A thin film (coating film) can be formed.

JP 2005-244155 A

  When a coating solution having a relatively high viscosity is applied to the substrate using such a coating apparatus, the piping from the coating solution tank to the die and the portion where the flow of the coating solution in the die is not smooth, such as elbow piping It may stay at a curved part or a valve corner, and air bubbles may be generated at the staying part. These bubbles not only prevent smooth liquid feeding of the coating solution, but also cause the bubbles to be ejected onto the substrate and affect the coating quality, such as the occurrence of streak-like defects.

  In order to suppress the generation of the bubbles, it is necessary to use a pipe that does not have a staying part such as a bent part of the pipe that causes the generation of the bubble. Therefore, it is impossible to remove the bent portion of the pipe. Further, when the supply speed of the coating liquid from the pump is increased in order to apply a coating liquid having a relatively high viscosity at a high speed, the resistance increases at the slit in the base, and as a result, the internal pressure of the base increases. Due to this increase in internal pressure, a great burden is placed on the piping, and in order to cope with this, the material of the piping is required to be made of resin or metal having strength.

  Therefore, a curved portion such as an L-shaped portion or a U-shaped portion that may cause bubbles is inevitably left in the pipe. However, in the case of a high viscosity liquid, the speed at which bubbles move through the liquid is slow, so that it is difficult to sufficiently degas even if a defoaming device such as a bubble removal valve is provided at the expected bubble generation location in the pipe. .

  In order to solve this problem, it is necessary to appropriately discharge the coating liquid in the piping and remove the accumulated bubbles. For this reason, a drain valve is appropriately provided in the pipe, the coating liquid in the pipe is discharged, the cleaning liquid is sent in, and a countermeasure and a filter and / or a deaeration device are installed to remove bubbles in the pipe. I came. However, since air bubbles are generated not only in the pipe but also in the base, the bubbles generated by the conventional drainage method cannot be removed sufficiently, and in the pipe, the air bubbles stay in the elbow corner of the pipe or the corner of the valve. Had the problem of being difficult to remove.

  Accordingly, an object of the present invention is to provide a coating apparatus and a coating method in which bubbles in a pipe are not mixed in the coating liquid even when a coating liquid having a relatively high viscosity is applied to the substrate, and there is no coating defect due to bubbles. Is to provide.

  In order to solve the above-described problems, the coating apparatus of the present invention has a slit formed at the tip, a base that discharges the coating liquid from the slit and applies the coating liquid to an object to be coated, and a tank that stores the coating liquid. A liquid supply pipe that is a path through which the coating liquid is sent from the tank to the base; a sealing member that is in contact with and away from the base and is in close contact with the base so as to cover the slit when in contact with the base; And the sealing member includes a coating liquid discharge port for discharging the coating liquid via the base, and a vacuum pump connected to the coating liquid discharge port via a pipe. It is characterized by having.

  According to the present invention, by providing the sealing member provided with the vacuum pump, it is possible to prevent air bubbles from being mixed into the coating liquid filled in the base from the tank. Specifically, this is a case where a coating liquid having a relatively high viscosity is applied to the substrate. Usually, the coating liquid stays in a corner portion such as an elbow of a pipe, and bubbles are generated in the coating liquid supplied from the tank. Even in the case of mixing, since the coating liquid can be supplied from the tank to the base in a state where the gas constituting the bubbles does not exist in the liquid feeding pipe, the mixing of bubbles can be prevented. As a result, the coating film can be formed on the substrate with high accuracy.

  The present invention is also characterized in that a filter for removing bubbles in the coating liquid discharged by the vacuum pump is provided in the pipe of the coating liquid draining apparatus.

  In this way, by removing air bubbles at the filtration unit, the coating liquid can be supplied again to the base and used for coating.

  In an embodiment of the present invention, the coating liquid discharge port is provided at an end portion in the longitudinal direction of the sealing member.

  By installing the pre-coating liquid discharge port at the longitudinal end of the sealing member in this way, the sealing member can be handled easily as a unit, and the coating liquid can be discharged via the slit of the base. The coating liquid mixed with bubbles can also be discharged without leaving the liquid supply pipe and the base.

  In another embodiment of the present invention, a plurality of the coating liquid discharge ports are provided at substantially equal intervals at the bottom of the sealing member.

  With this configuration, the coating liquid can be discharged uniformly without staying in the longitudinal direction of the sealing member, and the possibility of remaining bubbles can be further reduced.

  Further, the tank may be provided with a liquid feeding pressurizing means for feeding the coating liquid into the liquid feeding pipe in a state where the liquid feeding pipe is decompressed by the vacuum pump.

  According to this configuration, since the coating liquid is fed into the liquid feeding pipe by the liquid feeding pressurizing means in a state where the pressure inside the liquid feeding pipe is reduced, the pipe joint is formed by excessively reducing the pressure inside the liquid feeding pipe. For example, air can be prevented from entering the liquid feeding pipe.

  Furthermore, in order to solve the above-mentioned problem, the coating method of the present invention is a coating method using a base formed at the tip to discharge a coating liquid from a slit and apply the coating liquid to an object to be coated. The sealing portion is covered with a sealing member that is in close contact with the base so as to cover the slit when contacting the base, and the coating liquid is sent from the tank in which the coating liquid is stored to the base. The pressure is reduced through the slit by the vacuum pump provided in the sealing member, and the coating liquid is filled into the base through the liquid feeding pipe from the tank, and the sealing member The coating liquid is applied to the object to be coated after the coating liquid is discharged.

  According to this coating method, after the pressure in the liquid feeding pipe and the base is reduced through a slit by a vacuum pump provided in the sealing member, bubbles are formed by filling the base with the coating liquid from the tank through the liquid feeding pipe. Since the gas can be removed from the liquid feed pipe and filled with the coating liquid, bubbles can be prevented from being mixed into the coating liquid, and a coating film free from coating defects can be formed.

  Further, when the liquid feeding pipe is depressurized to a predetermined pressure lower than the atmospheric pressure, the tank may be pressurized to supply the coating liquid from the tank to the liquid feeding pipe.

  According to this structure, it can suppress that air penetrate | invades into liquid feeding piping from a pipe joint etc. by the pressure inside the liquid feeding piping being reduced too much.

  According to the present invention, even when a coating liquid having a relatively high viscosity is applied to the substrate, it is possible to prevent bubbles in the piping from being mixed into the coating liquid. It is possible to form a coating film having a uniform thickness without application defects.

It is the schematic which shows one Embodiment of the coating device of this invention. It is a schematic block diagram of the coating system of 1st embodiment of this invention. It is sectional drawing of the sealing member in 1st embodiment of this invention, and a nozzle | cap | die. It is sectional drawing of another Example of the sealing member in 1st embodiment of this invention. It is a schematic block diagram of the coating system of 2nd embodiment of this invention. It is an operation | movement flowchart of the liquid passage in this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an embodiment of a coating apparatus 1 of the present invention. The coating apparatus 1 includes a stage 2 on which a substrate W such as glass can be placed, a base 3 in which a slit 21 is formed, and a horizontal movement (X-direction movement) of the base 3 with respect to the substrate W on the stage 2. And a driving device 4 that freely and independently performs vertical movement (movement in the Z direction). The coating apparatus 1 further includes a tank 9 for storing the coating liquid, and a liquid feeding means including a pump 8 for supplying the coating liquid in the tank 9 to the base 3 as a liquid supply unit. Between the tank 9 and the base 3 via the pump 8, a liquid supply pipe 17 constituting a flow path for the coating liquid is installed.

  In the present embodiment, the coating liquid applied by the coating apparatus 1 is a liquid having a relatively high viscosity at room temperature. Examples of the coating solution include a polyimide solution for a touch panel substrate. The comparatively high viscosity here means 20 mPas or more. In addition, the pump 8 has a cylindrical shape inside the cross section in the discharge direction, and has a piston 10 in the inside. The piston 10 is moved between the top dead center and the bottom dead center in the cylinder of the pump 8 by a driving device (not shown).

  According to this coating apparatus 1, after the base 3 is vertically lowered by the driving device 4 so that the parallel clearance between the tip portion 23 and the substrate W becomes a predetermined value, the pump 8 is disposed in the tank 9. By supplying the coating liquid to the base 3 and discharging the coating liquid from the slit 21 while moving the base 3 horizontally, a thin film (coating film) M made of the coating liquid is formed on the substrate W, and the coating liquid is applied. be able to. For this reason, the moving direction of the die 3 is the coating direction (X direction).

  In addition, the coating apparatus 1 includes a control device 5 that controls the operation of each part of the coating device 1, and the control device 5 performs the coating operation of discharging the coating liquid onto the substrate W in addition to the movement of the base 3. Control.

  Further, the coating apparatus 1 further has a sealing member 30 as shown in FIGS. 2 and 3, and when the coating liquid is supplied from the tank 9 to the base 3, the sealing member 30 covers the slit 21. The process is performed in close contact with the base 3.

  In FIG. 3, the inside of the base 3 is shown by a cross section orthogonal to the longitudinal direction. The longitudinal direction of the base 3 coincides with the base width direction, and is hereinafter referred to as the base width direction. The slit 21 of the base 3 is formed in the width direction of the base 3, and is opened at the front end portion 23 which is the front end of the base 3 (lower end of the base 3). The gap amount B is the width of the base 3. Constant along the direction. The width direction of the base 3 is a horizontal direction (Y direction) orthogonal to the application direction (X direction), and the gap amount B of the slit 21 is a dimension obtained by measuring the slit 21 in the X direction. The base 3 is made of metal such as SUS material or ceramic.

  The slit 21 has an elongated shape when viewed in the Z direction, which is the flow direction of the coating liquid, and is long in the width direction (Y direction) and narrow in the coating direction (X direction). The slit 21 is connected to the manifold 11 formed inside the base 3. Similarly to the slit 21, the manifold 11 is also formed long in the width direction.

  The coating liquid is discharged from the tip of the die 3 through the manifold 11 and the slit 21. That is, the front end portion 23 which is an opening at the lower end of the slit 21 serves as a discharge port for the coating liquid. The tip portion 23 of the base 3 where the slit 21 is open is horizontal and is formed linearly over the entire length in the width direction.

  The liquid supply pipe 17 extending from the pump 8 is fluidly connected to a supply port 18 provided in the base 3 shown in FIG. 3, and a flow path 19 extending from the supply port 18 to the manifold 11 is provided in the base 3. Is formed.

  The coating solution supplied to the manifold 11 is expanded in the width direction of the die 3 here, and then flows in the order of the slits 21 and is discharged onto the substrate W.

  A liquid supply pipe 17 extending from the pump 8 and the coating liquid tank 9 to the base 3 has a configuration shown in FIG. The coating solution in the tank 9 is pressurized with an inert gas such as clean air or nitrogen, and the coating solution is sent to the suction valve 40. The operation of supplying the coating liquid to the pump 8 is to open the suction valve 40 and send the liquid to the pump 8, move the piston 10 of the pump 8 toward the bottom dead center, and depressurize the inside of the pump 8 to pump the coating liquid. Satisfy 8 When the pump 8 is filled with the coating liquid, the suction valve 40 is closed and then the discharge valve 41 is opened. When the piston 10 of the pump 8 moves in the direction of the top dead center, the coating liquid in the pump 8 is supplied to the base 3 via the discharge valve 41.

  In the case where the coating liquid is passed from the tank 9 to the base 3 in a state where the coating liquid is not passed through the liquid feeding pipe 17 (this is referred to as liquid passage in this description), the suction valve 40 is described later in this embodiment. Is closed and the discharge valve 41 is opened, the inside of the liquid supply pipe 17 is decompressed through the tip 23 of the slit 21, the suction valve 40 is opened, and the coating liquid is supplied from the tank 9 to the tip 23. Fill.

  Here, it is ideal that the liquid feeding pipe 17 is linearly formed from the tank 9 through the pump 8 to the base 3, but in order to actually incorporate the liquid feeding pipe 17 into the coating apparatus 1, It is necessary to change a direction using piping members (not shown), such as. However, since the gas component is generally dissolved in the coating liquid, the gas component is easily dissolved from the coating liquid due to a change in pressure or temperature, and the elbow corner (not shown) or the corner of the valve of the liquid feeding pipe 17 is not shown. The possibility of collecting as bubbles in the part is considerably increased. In addition, a part of the elbow or the valve that is not filled with the coating liquid is generated even when the liquid is passed, and the gas accumulated in the part may be dissolved in the coating liquid as bubbles.

  FIG. 3 is a cross-sectional view of one embodiment of the present invention. As shown in FIG. 2, the entire length of the sealing member 30 is longer than the slit 21 of the base 3, and a recess 32 that can cover the entire slit 21 or at least the tip 23 thereof is provided at the center. Further, a coating liquid discharge port 33 is provided at one end of the sealing member 30 in the base width direction as shown in FIG. Further, the vacuum pump 43 is communicated with the sealing member 30 through the pipe 19 from the coating liquid discharge port 33. By driving the vacuum pump 43 using a control device (not shown), the base is connected via the coating liquid discharge port 33. 3. The gas and the coating liquid in the liquid feeding pipe 17, the pump 8, the suction valve 40, and the discharge valve 41 can be sucked and discharged.

  The sealing member 30 can freely come into contact with and separate from the base 3, and as a contacting / separating method, a method in which the sealing member 30 moves up / down with respect to the base 3, and a base 3 moves up / down with respect to the sealing member 30. There are two methods, but either one can be used. In the present embodiment, the method is described in which the base 3 is raised / lowered with respect to the sealing member 30. Further, the alignment of the base 3 with the sealing member 30 in the X direction uses the movement of the base 3 in the X direction. Regarding the alignment in the X direction, the base 3 may be fixed in the X direction and the sealing member 30 may be moved. The method of moving the sealing member can be used for a coating apparatus using a coating method for fixing the die in the X direction, such as a substrate floating coating type coater.

  Further, the recess 32 of the sealing member 30 comes into contact with the base 3 when the opening end 34 of the sealing member 30 passes liquid. After the contact between the base 3 and the opening end 34, the slit 21, the manifold 11, and the liquid feeding pipe 17 are depressurized by driving the vacuum pump 43. In this case, if a gap is formed between the opening end 34 and the base 3, There is a problem that the pressure does not drop. Therefore, the recess 32 of the sealing member 30 is provided with an elastic member 31 including a rubber material or a porous member to ensure the close contact between the sealing member 30 and the base 3.

  Furthermore, with respect to the relative position in the Z direction between the sealing member 30 and the base 3 at the time of discharging the coating liquid, the opening effect of the elastic member 31 is exhibited while the opening end of the sealing member 30 is not damaged. It is necessary to position the base 3 at a position where the base 34 is in contact with the base 3. Therefore, it is only necessary to set a reference position on the base 3 and move the base 3 in the direction of the arrow a in FIGS. 2 and 3 from the reference position by a movement amount calculated in advance. Alternatively, the sealing member 30 or the base 3 may be provided with a micro switch, a proximity sensor, or a distance measuring sensor, and the relative position may be determined based on whether the switch or sensor is turned on or off or whether a specified value is reached. As another method, the relative position may be determined by blocking transmitted light when the sealing member 30 and the base 3 come into contact with each other using a transmission type optical sensor. Regarding the setting method, it can be used in a mechanism for moving the sealing member 30 as well.

  The sealing member 30 is provided with a coating liquid discharge port 33 at one end in the longitudinal direction. If the length of the sealing member 30 exceeds a value determined by the coating liquid, the sealing member 30 is coated at both ends. A liquid outlet may be provided. Thereby, even if it is a case where the length of the sealing member 30 exceeds the said value, a coating liquid can be discharged | emitted uniformly. Also, as shown in FIG. 4, coating liquid discharge ports 33b may be provided at substantially equal intervals at the bottom of the sealing member 30b. Also by this method, the coating liquid can be uniformly discharged from the sealing member 30b.

  The gas and coating liquid discharged from the sealing member 30 are sucked into the vacuum pump 43 via the pipe 19. The pipe 19 may be provided with a discharge valve 42 for controlling the discharge of the coating liquid. Alternatively, the coating liquid sucked by the vacuum pump 43 may be returned to the tank 9 after being filtered by a filter (not shown). By adopting this configuration, it is possible to prevent the coating liquid from being consumed wastefully even when the coating liquid is expensive.

  Further, a tank may be provided in the middle of the pipe 19 so that the coating liquid is accumulated in the tank and the gas is taken into the vacuum pump 43.

  FIG. 5 is a schematic view showing another embodiment of the present invention. In this embodiment, the sealing member 30 c has only a function of sealing the slit 21 of the base 3. The sealing member 30b has the same configuration as the first embodiment except that there is no coating liquid discharge port.

  In this embodiment, the coating liquid discharge port 33 c is provided at the longitudinal end of the base 3. The gas and coating liquid present in the path from the base 3 to the tank 9 are sucked into the vacuum pump 43 through the pipe 19 from the coating liquid discharge port 33c, and the coating liquid in the slit 21 is also discharged simultaneously. With this configuration, it is not necessary to provide piping on the sealing member 30c, and the technique of the present invention can be applied even when it is difficult to provide a complicated mechanism in a region below the substrate.

  Furthermore, in this embodiment, the sealing member 30c may be provided with a minute opening to facilitate the suction from the slit 21. When the viscosity of the coating liquid is high, the slit 21 that is a narrow gap has a large flow resistance, and suction may not be performed completely. Therefore, by providing an opening that prevents the high-viscosity coating liquid from leaking out, the suction from the slit 21 can be easily performed.

  Next, an operation sequence of the liquid passing operation in the present invention will be described. The liquid passing operation in the present invention causes a certain amount of consumption even if the coating liquid is collected and reused. It is not preferable. Therefore, it is preferable that the discharge operation of the coating liquid in the present invention is performed when the coating liquid is replaced or in a certain cycle, for example, every 1000 sheets of the substrate. Hereinafter, the operation sequence will be described based on the operation flow of FIG. 6 with respect to an embodiment in which the coating liquid is replaced.

  First, as step S1, the coating liquid to be replaced is discharged.

  Next, as step S2, the solvent is supplied to all the coating liquid supply systems including the tank 9, the pump 8, the liquid feeding pipe 17, and the base 3, and the old coating liquid is cleaned and removed.

  Next, as step S3, the new coating liquid is filled up to the tank 9. At this time, the suction valve 40 is in a closed state.

  Next, as step S <b> 4, the base 3 is moved by the driving device 4 so that the sealing member 30 is directly below the base 3.

  Next, in step S5, the base 3 is moved by a predetermined distance in the Z-axis direction by the driving device 4, and the opening end 34 of the sealing member 30 and the base 3 come into contact with each other.

  Next, as Step S6, the inside of the base 3, the liquid feeding pipe 17, and the pump 8 is decompressed by the vacuum pump 43 through the tip 23 of the base 3 while the discharge valve 41 is open. At this time, the closer the suction valve 40 is to the tank 9, the more pressure can be reduced in the liquid feeding pipe 17. The piston 10 of the pump 8 is preferably located at the bottom dead center. As a result, it is possible to cope with a normal application operation immediately after the liquid is passed.

  Next, as Step S7, the suction valve 40 is opened to fill the pump 8, the liquid feeding pipe 17, and the base 3 with the coating liquid. Thereby, the liquid passage is completed.

  Thus, by performing liquid passage in a state where the inside of the base 3, the liquid feeding pipe 17, and the pump 8 is decompressed, the gas constituting the bubbles can be excluded from the liquid feeding pipe and filled with the coating liquid. It is possible to prevent air bubbles from being mixed into the coating solution.

  Here, the suction is further performed by the vacuum pump 43, whereby the coating liquid is discharged from the tip portion 23 of the base 3 to the sealing member 30. As a result, even if bubbles are mixed into the coating liquid due to a slight amount of gas remaining in the liquid feeding pipe 17 or the like, the effect of the air vent performed by the conventional coating apparatus can be achieved by discharging the coating liquid mixed with the bubbles from the base 3. Can be obtained.

  Finally, as step S8, the suction is stopped by stopping the vacuum pump 43 or closing the discharge valve 42, and after closing the suction valve 40, the sealing member 30 and the base 3 are moved to the arrow b in FIG. 2 or FIG. The base 3 moves to a predetermined position in the X direction, and a normal coating operation can be started. In addition, description is abbreviate | omitted about normal application | coating operation | movement.

  With the above coating apparatus and coating method, even when a coating liquid having a relatively high viscosity is applied to the substrate, air bubbles in the piping can be prevented from being mixed into the coating liquid. It is possible to form a coating film having a uniform thickness free from application defects due to bubbles.

  The present invention is particularly intended for high-viscosity coating liquids, but the application liquid discharging operation of the present invention can be applied when bubbles are generated even in low-viscosity coating liquids. Further, when the viscosity of the coating liquid is high and it is difficult to pass the liquid only by the suction of the vacuum pump 43, auxiliary means such as pressurizing the coating liquid from the tank 9 may be added. Further, all or part of the liquid supply path from the tank 9 to the base 3 may be heated to increase the fluidity of the coating liquid and facilitate the discharge of the coating liquid.

  In the above-described embodiment, the example in which the suction valve 40 is opened and the liquid feeding pipe 17 is filled with the coating liquid after the inside of the liquid feeding pipe 17 has been sufficiently depressurized has been described. When a smaller predetermined pressure is reached, the suction valve 40 may be opened to supply the coating liquid to the liquid feeding pipe 17.

  Specifically, liquid supply pressurizing means (not shown) is provided in the tank 9, and an inert gas such as clean air or nitrogen is supplied into the tank 9 according to the pressure in the liquid supply pipe 17. As a result, the coating liquid is supplied into the liquid feeding pipe 17. In this embodiment, when a predetermined pressure lower than the atmospheric pressure is reached, the inside of the tank 9 is pressurized by the liquid feeding and pressurizing means, and the coating liquid is supplied. This predetermined pressure is caused by excessively reducing the pressure in the liquid feeding pipe 17, so that the air is fed into the liquid feeding pipe 17 from the pipe joint such as the valve 41 or the connecting portion between the pump 8, the cap 3 and the liquid feeding pipe 17. The pressure is such that it does not enter the water.

  Therefore, similarly to the above embodiment, the base 3, the liquid feeding pipe 17, and the pump 8 are decompressed by bringing the sealing member 30 into contact with the base 3 and operating the vacuum pump 43. When the inside of the liquid feeding pipe 17 (including the base 3 and the pump 8) reaches a predetermined pressure, the valve 40 is opened, and the tank 9 is pressurized by the liquid feeding pressurizing means, and the coating liquid is put into the liquid feeding pipe 17. Is supplied. That is, when the inside of the liquid feeding pipe 17 reaches a predetermined pressure, the coating liquid is supplied into the liquid feeding pipe 17 before air enters from the pipe joint and the connecting portion. Air can be prevented from entering the inside. Thereby, since the coating liquid is supplied in a state where the air is removed by reducing the pressure in the liquid feeding pipe 17, it is possible to suppress the bubbles from being mixed into the coating liquid in the liquid feeding pipe 17.

  1: coating device 3: base 8: pump 9: tank 10: piston 11: manifold 17: liquid supply piping 19: piping 21: slit 23: tip portion 30: sealing member 31: elastic member 33: coating liquid discharge port 40 : Suction valve 41: Discharge valve 42: Discharge valve W: Substrate

Claims (7)

A slit is formed at the tip, and a base for discharging the coating liquid from the slit and applying the coating liquid to the object to be coated;
A tank for storing the coating liquid;
A liquid feed pipe which is a path through which the coating liquid is sent from the tank to the base;
A sealing member that is in contact with and away from the base and is in close contact with the base so as to cover the slit when in contact with the base;
With
The sealing member includes a coating liquid drainage device including a coating liquid drainage port for discharging the coating liquid via the base and a vacuum pump connected to the coating liquid discharge port via a pipe. A characteristic coating apparatus.   The coating apparatus according to claim 1, wherein a filter for removing bubbles in the coating liquid discharged by the vacuum pump is provided in the pipe of the coating liquid draining apparatus.   The coating apparatus according to claim 1, wherein the coating liquid discharge port is provided at an end portion in a longitudinal direction of the sealing member.   The coating apparatus according to claim 1 or 2, wherein a plurality of the coating liquid discharge ports are provided at substantially equal intervals at the bottom of the sealing member.   The liquid supply pressurizing means for supplying the coating liquid into the liquid supply pipe in a state where the liquid supply pipe is depressurized by the vacuum pump in the tank. 5. The coating apparatus according to any one of 4 above. It is a coating method using a die that discharges a coating liquid from a slit formed at the tip and applies the coating liquid to an object to be coated,
It can be freely attached to and separated from the base, and the slit is covered by a sealing member that is in close contact with the base so as to cover the slit when in contact with the base, and is applied to the base from a tank in which a coating solution is stored. After depressurizing the liquid feeding pipe which is a path through which the liquid is fed and the inside of the base through the slit by a vacuum pump provided in the sealing member, the base is filled with the coating liquid through the liquid feeding pipe from the tank, A coating method, wherein the coating liquid is applied to the object to be coated after the coating liquid is discharged to the sealing member.   The coating liquid is supplied from the tank to the liquid supply pipe by pressurizing the tank when the liquid supply pipe is depressurized to a predetermined pressure lower than the atmospheric pressure. Application method.

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