JP6347708B2 - Coating apparatus and cleaning method - Google Patents

Description

  The present invention relates to a coating apparatus for coating a material to be coated on a surface to be processed and a cleaning method for the coating apparatus.

  Conventionally, glass substrates for liquid crystal display devices, semiconductor wafers, glass substrates for PDP, glass substrates for photomasks, substrates for color filters, substrates for recording disks, substrates for solar cells, substrates for electronic paper, etc. In the manufacturing process, a coating apparatus for coating a coating material such as a photoresist on the surface of a substrate is used. A conventional coating apparatus is described in Patent Document 1, for example. The coating apparatus of Patent Document 1 discharges a material to be coated onto the surface of a substrate from a slit-shaped discharge port provided in the nozzle while moving the nozzle relative to the substrate.

JP 2007-253093 A

  In this type of coating apparatus, it is necessary to periodically clean the inside of the nozzle and the inside of the pipe connected to the nozzle. At the time of cleaning, a rinse liquid such as an organic solvent is supplied to the inside of the nozzle through a pipe. When the viscosity of the material to be coated is low and the difference between the viscosity of the material to be coated and the viscosity of the rinsing liquid is small, the material to be coated adhered to the inside of the nozzle or the inner wall of the pipe can be easily washed away with the rinsing liquid it can.

  However, when a highly viscous material to be coated is used, it is difficult to wash away the material to be coated adhering to the inside of the nozzle or the inner wall of the pipe with a rinse liquid having a low viscosity. For this reason, it takes time for cleaning, and the amount of the rinse liquid used increases. Moreover, when using a highly viscous coating material, in order to ensure the fluidity of a coating material, the internal diameter of piping must be enlarged. For this reason, it becomes difficult to make the rinse liquid contact the entire inner wall of the large-diameter pipe.

  In recent years, in a manufacturing process of a flexible device or a battery, there is an increasing demand for an apparatus that applies a high-viscosity material on a surface to be processed. Along with this, a technique for efficiently cleaning the inside of the nozzle and the pipe to which the high-viscosity material to be applied has adhered has increased in importance.

  The present invention has been made in view of such circumstances, and a coating apparatus and a cleaning system that can efficiently clean a material to be coated attached to an inner wall of a supply pipe using a rinse liquid having a viscosity lower than that of the material to be coated. It aims to provide a method.

In order to solve the above-described problem, a first invention of the present application is a coating apparatus that applies a material to be coated, which is a fluid, to a surface to be processed, the nozzle having a discharge port for discharging a fluid, and the nozzle to the nozzle A supply mechanism that selectively supplies a material to be coated and a rinsing liquid that is a fluid having a viscosity lower than that of the material to be coated; and a control unit that controls the supply mechanism. In the cleaning process of cleaning the supply pipe and the nozzle with the rinse liquid, the connected supply pipe and flow rate switching means for changing the fluid velocity in the supply pipe are provided. while continuing the supply of the rinsing liquid by the supply mechanism, the flow rate switching means is operated Ru varying the speed of the rinsing liquid.

  2nd invention of this application is a coating device of 1st invention, Comprising: The said flow-velocity switching means contains the on-off valve provided on the said supply piping.

  3rd invention of this application is a coating device of 1st invention, Comprising: The said flow velocity switching means contains the pump provided on the said supply piping.

  A fourth invention of the present application is the coating apparatus according to any one of the first to third inventions, wherein the control unit repeats the flow rate switching means at predetermined intervals when the rinse liquid is supplied. Make it work.

  A fifth invention of the present application is the coating apparatus according to any one of the first to fourth inventions, wherein a discharge pipe for discharging a gas from the nozzle and a decompression for generating a negative pressure in the discharge pipe. A mechanism, and the controller operates the decompression mechanism when the rinsing liquid is supplied.

  6th invention of this application is a coating device of 5th invention, Comprising: The said pressure reduction mechanism has a pressure reduction tank to which the edge part of the downstream of the said discharge piping is connected, and flowed into the said discharge piping from the said nozzle The rinse liquid is further stored in the decompression tank, and further includes a circulation mechanism for re-supplying the rinse liquid stored in the decompression tank to the supply mechanism.

  7th invention of this application is a coating device of 5th invention or 6th invention, Comprising: The said discharge outlet is the slit-shaped opening provided in the lower part of the said nozzle, The said discharge piping is the upper part of the said nozzle It is connected to the outlet provided in the.

According to an eighth aspect of the present invention, there is provided a coating apparatus that supplies a material to be coated, which is a fluid, from a supply pipe to a nozzle and discharges the material from a discharge port of the nozzle, wherein the supply pipe and the nozzle have a viscosity higher than that of the material to be coated. a cleaning method of cleaning with a rinsing liquid is low fluid, a) a step of initiating the supply of the rinse liquid to the nozzle from the supply pipe, b) after step a), the rinsing Changing the flow rate of the rinse liquid in the supply pipe while continuing to supply the liquid .

  A ninth invention of the present application is the cleaning method of the eighth invention, wherein, in the step b), the flow rate of the rinse liquid is repeatedly changed at predetermined time intervals.

  A tenth invention of the present application is the cleaning method of the eighth invention or the ninth invention, further comprising c) a step of generating a negative pressure in the discharge pipe for discharging the gas from the nozzle.

  The eleventh invention of the present application is the cleaning method of the tenth invention, further comprising: d) re-supplying the rinse liquid that has flowed into the discharge pipe in the step c) to the upstream side of the supply pipe.

  According to the first to eleventh aspects of the present invention, the flow rate of the rinsing liquid can be changed in the supply pipe. Thereby, the to-be-coated material adhering to the inner wall of supply piping can be wash | cleaned efficiently.

  In particular, according to the second invention of the present application, the flow rate of the rinsing liquid can be changed without complicating the configuration of the supply mechanism.

  In particular, according to the third invention of the present application, the flow rate of the rinse liquid can be changed to a desired value by selecting the pressure of the pump.

  In particular, according to the fourth and ninth inventions of the present application, the cleaning effect of the rinse liquid can be further enhanced.

  In particular, according to the fifth and tenth aspects of the present invention, the rinse liquid supplied from the supply mechanism flows into the discharge pipe. Thereby, the inside of discharge piping can be washed.

  In particular, according to the sixth and eleventh inventions of the present application, the rinse liquid once used can be reused. Thereby, the usage-amount of a rinse liquid can be reduced.

  In particular, according to the seventh invention of the present application, the rinse liquid supplied into the nozzle flows toward the upper outlet. For this reason, the pressure of the rinse liquid with respect to the to-be-coated material which plugs up a discharge outlet is reduced. As a result, it is possible to evenly wash away the material to be coated that closes the discharge port. Therefore, it is difficult for the rinse liquid to be discharged from only a part of the slit-shaped discharge port.

It is a perspective view of a coating device. It is a perspective view of a slit nozzle. It is the figure which showed the flow path inside a slit nozzle. It is the figure which showed the structure of the piping system connected to a slit nozzle. It is the block diagram which showed the connection structure of a control part and each part of a piping system. It is a flowchart which shows the flow of a washing process. It is the figure (this embodiment) which showed the mode in the slit nozzle during a washing process. It is the figure (comparative example) which showed the mode in the slit nozzle during a washing process. It is a time chart which shows the example of the opening / closing operation | movement of a 3rd on-off valve or a 4th on-off valve. It is the figure which showed the structure of the piping system in the coating device which concerns on a modification.

  Embodiments of the present invention will be described below with reference to the drawings. Hereinafter, for convenience of explanation, the moving direction of the slit nozzle 20 in the coating apparatus is referred to as “front-rear direction”, and the horizontal direction orthogonal to the front-rear direction is referred to as “left-right direction”.

<1. About the configuration of the coating device>
FIG. 1 is a perspective view of a coating apparatus 1 according to an embodiment of the present invention. The coating apparatus 1 is an apparatus that applies a fluid material to be coated (for example, a resin such as polyimide) to the upper surface of a glass carrier substrate 9 in a manufacturing process of a flexible device. The material to be applied applied to the upper surface of the substrate 9 is then solidified into a thin film. Moreover, a pattern such as an electrode is formed on the surface of the thin film, and a flexible device is formed by peeling the thin film from the substrate 9.

  As shown in FIG. 1, the coating apparatus 1 according to the present embodiment includes a stage 10, a slit nozzle 20, a nozzle holding unit 30, a travel mechanism 40, and a control unit 50.

  The stage 10 is a substantially rectangular parallelepiped holding table on which the substrate 9 is placed and held. The stage 10 is formed of, for example, an integral stone material. The upper surface of the stage 10 is a flat substrate holding surface 11. The substrate holding surface 11 is provided with a number of vacuum suction holes (not shown). When the substrate 9 is placed on the substrate holding surface 11, the lower surface of the substrate 9 is attracted to the substrate holding surface 11 by the suction force of the vacuum suction holes. Thereby, the substrate 9 is fixed in a horizontal posture on the stage 10. A plurality of lift pins are provided inside the stage 10. When unloading the substrate 9 from the stage 10, a plurality of lift pins protrude on the substrate holding surface 11. As a result, the substrate 9 is pulled away from the substrate holding surface 11.

  The slit nozzle 20 is a nozzle that discharges a material to be coated. The slit nozzle 20 has a nozzle body 21 that is long in the left-right direction. A slit-shaped discharge port 23 extending in the left-right direction is provided at the lower end of the nozzle body 21. The discharge port 23 is directed to the upper surface of the substrate 9 placed on the stage 10. When the material to be coated is supplied into the nozzle body 21 from a supply mechanism 60 (see FIG. 4) described later, the material to be coated is directed from the discharge port 23 of the slit nozzle 20 toward the upper surface of the substrate 9 to be processed. Discharged. A more detailed structure of the slit nozzle 20 will be described later.

  The nozzle holding unit 30 is a mechanism for holding the slit nozzle 20 above the substrate holding surface 11. The nozzle holding part 30 includes a bridging part 31 extending in the left-right direction and a pair of columnar support parts 32 that support both ends of the bridging part 31. The slit nozzle 20 is attached to the lower surface of the bridging portion 31. Each support portion 32 includes an elevating mechanism 33 that adjusts the height of the end portion of the bridging portion 31. When the left / right lifting mechanism 33 is operated, the height and posture of the slit nozzle 20 are adjusted together with the bridging portion 31.

  The traveling mechanism 40 is a mechanism for moving the slit nozzle 20 in the front-rear direction. The travel mechanism 40 includes a pair of travel rails 41 and a pair of linear motors 42. The pair of running rails 41 extend in the front-rear direction near the left and right sides of the stage 10. The traveling rail 41 guides the lower end portion of each support portion 32 in the front-rear direction while supporting the pair of support portions 32. That is, the pair of running rails 41 function as a linear guide that regulates the moving direction of the pair of support portions 32 in the front-rear direction.

  The linear motor 42 includes a stator 421 fixed to the stage 10 and a mover 422 fixed to the support portion 32. The stator 421 extends in the front-rear direction along the left and right side edges of the stage 10. When the coating apparatus 1 is in operation, a magnetic attractive force or a magnetic repulsive force is generated between the stator 421 and the mover 422. Thereby, the movable element 422, the nozzle holding part 30, and the slit nozzle 20 move in the front-rear direction as a unit.

  The controller 50 is a means for controlling the operation of each unit in the coating apparatus 1. As conceptually shown in FIG. 1, the control unit 50 is configured by a computer having an arithmetic processing unit 51 such as a CPU, a memory 52 such as a RAM, and a storage unit 53 such as a hard disk drive. The control unit 50 is electrically connected to each part in the coating apparatus 1 such as the lift pin, the lifting mechanism 33, and the linear motor 42 described above. The control unit 50 is also electrically connected to a supply mechanism 60, a discharge mechanism 80, and a pump and an on-off valve provided in the circulation mechanism 90, which will be described later. The control unit 50 temporarily reads the computer program and data stored in the storage unit 53 into the memory 52, and the calculation processing unit 51 performs calculation processing based on the computer program and data, whereby the coating apparatus 1 is processed. The operation of each part is controlled. Thereby, the application | coating process with respect to the board | substrate 9 and the washing | cleaning process mentioned later progress.

<2. Structure of slit nozzle>
Next, a more detailed structure of the slit nozzle 20 will be described. FIG. 2 is a perspective view of the slit nozzle 20. FIG. 3 is a view showing the flow path 210 inside the slit nozzle 20.

  As shown in FIG. 2, the nozzle body 21 of the slit nozzle 20 includes a pair of nozzle members 211 and 212 and a pair of side plates 213 and 214. As a material of the nozzle members 211 and 212 and the side plates 213 and 214, for example, a metal such as aluminum is used. When the pair of nozzle members 211 and 212 are fixed to each other and the pair of side plates 213 and 214 are attached to the left and right ends thereof, the nozzle body 21 having the flow path 210 therein is formed.

  The nozzle body 21 is provided with a pair of supply ports 22 and one slit-like discharge port 23. The pair of supply ports 22 are provided in the pair of side plates 213 and 214, respectively. One discharge port 23 opens in a slit shape between the lower end portion of the front nozzle member 211 and the lower end portion of the rear nozzle member 212. When the coating apparatus 1 is in operation, the material to be coated is supplied from the pair of supply ports 22 to the flow path 210 in the nozzle body 21. Then, the material to be coated in the flow path 210 is discharged from the discharge port 23 toward the lower side of the nozzle body 21.

  Further, as shown in FIG. 2, the nozzle body 21 of the present embodiment has one discharge port 24. The discharge port 24 is provided on the upper surface of the nozzle body 21. When cleaning the slit nozzle 20, the air bubbles mixed in the flow path 210 in the nozzle body 21 are discharged together with the rinsing liquid to a discharge pipe 81 to be described later through the discharge port 24. Thereby, bubbles are removed from the flow path 210 in the nozzle body 21.

<3. Configuration of piping system connected to slit nozzle>
Next, the configuration of the piping system related to the supply and discharge of the material to be coated and the rinse liquid will be described. FIG. 4 is a diagram showing a configuration of a piping system connected to the slit nozzle 20. As shown in FIG. 4, the coating apparatus 1 of the present embodiment includes a supply mechanism 60, a discharge mechanism 80, and a circulation mechanism 90.

  The supply mechanism 60 is a mechanism for selectively supplying the material to be coated and the rinse liquid to the slit nozzle 20. The supply mechanism 60 includes a material supply source 61, a first supply pipe 62, a first on-off valve 63, a rinse liquid supply source 64, a second supply pipe 65, a second on-off valve 66, a deaeration tank 67, and a main supply pipe. 68, a supply pump 69, two branch supply pipes 70, a third on-off valve 71, a fourth on-off valve 72, a first air supply source 73, a first air supply pipe 74, and a first air on-off valve 75. .

  The material to be coated 61 stores material to be coated on the upper surface of the substrate 9. As the material to be coated, for example, a molten resin such as polyimide, which is a fluid with high viscosity, is used. The viscosity of the material to be coated is, for example, about several thousand to 10,000 cP. The material supply source 61 and the degassing tank 67 are connected by a first supply pipe 62. A first on-off valve 63 is inserted on the path of the first supply pipe 62. Therefore, when the first on-off valve 63 is opened, the material to be coated is supplied from the material supply source 61 to the deaeration tank 67 through the first supply pipe 62. When the first on-off valve 63 is closed, the supply of the material to be applied from the material supply source 61 to the deaeration tank 67 is stopped.

  The rinse liquid supply source 64 stores a rinse liquid for cleaning the slit nozzle 20 and piping connected to the slit nozzle 20. A fluid having a lower viscosity than the material to be coated (for example, pure water or an organic solvent) is used for the rinsing liquid. The viscosity of the rinse liquid is, for example, about 1 to several cP. The rinse liquid supply source 64 and the deaeration tank 67 are connected by a second supply pipe 65. A second on-off valve 66 is inserted on the path of the second supply pipe 65. For this reason, when the second on-off valve 66 is opened, the rinse liquid is supplied from the rinse liquid supply source 64 to the deaeration tank 67 through the second supply pipe 65. When the second on-off valve 66 is closed, the supply of the rinse liquid from the rinse liquid supply source 64 to the deaeration tank 67 is stopped.

  The deaeration tank 67 is a container for temporarily storing a material to be coated or a rinse liquid. Bubbles and dissolved gas contained in the material to be coated or the rinse liquid are removed in the degassing tank 67. The deaeration tank 67 is connected to the first air supply source 73 via the first air supply pipe 74. The first air supply source 73 stores pressurized air. A first air on-off valve 75 is interposed on the path of the first air supply pipe 74. When the first air opening / closing valve 75 is opened, pressurized air is supplied from the first air supply source 73 into the deaeration tank 67 through the first air supply pipe 74. As a result, the surface of the material to be coated or the rinse liquid stored in the deaeration tank 67 is pressurized. Instead of the pressurized air, an inert gas such as a pressurized nitrogen gas may be supplied into the deaeration tank 67.

  The upstream end of the main supply pipe 68 is connected to the bottom of the deaeration tank 67. The upstream end portions of the two branch supply pipes 70 are connected to the downstream end portions of the main supply pipe 68. Further, the downstream ends of the two branch supply pipes 70 are respectively connected to the two supply ports 22 of the slit nozzle 20. The inner diameters of the main supply pipe 68 and the branch supply pipe 70 have sufficient dimensions to allow the material to be coated having a high viscosity to flow.

  A supply pump 69 is provided on the path of the main supply pipe 68. A third on-off valve 71 and a fourth on-off valve 72 are provided on each path of the two branch supply pipes 70, respectively. When supplying the rinse liquid, the first air on-off valve 75, the third on-off valve 71, and the fourth on-off valve 72 are opened. Then, the rinsing liquid stored in the deaeration tank 67 is pushed out to the main supply pipe 68 by the pressurization in the deaeration tank 67. Then, the rinse liquid is supplied to the flow path 210 in the slit nozzle 20 through the main supply pipe 68 and the two branch supply pipes 70. When supplying the material to be coated, the on-off valve 75, the third on-off valve 71, and the fourth on-off valve 72 are opened and the supply pump 69 is operated. Then, due to the pressurization in the deaeration tank 67 and the action of the supply pump 69, the material to be coated stored in the deaeration tank 67 passes through the main supply pipe 68 and the two branch supply pipes 70, and the slit nozzle. 20 is supplied to the flow path 210 in 20.

  The discharge mechanism 80 is a mechanism for discharging the gas accumulated near the discharge port 24 of the slit nozzle 20 to the outside. The discharge mechanism 80 includes a discharge pipe 81, a fifth on-off valve 82, a decompression tank 83, and a decompression pump 84. The upstream end of the discharge pipe 81 is connected to the discharge port 24 of the slit nozzle 20. The downstream end of the discharge pipe 81 is connected to the decompression tank 83. A fifth on-off valve 82 is provided on the path of the discharge pipe 81.

  At the time of cleaning to be described later, the rinsing liquid is supplied from the supply mechanism 60 to the slit nozzle 20, the fifth on-off valve 82 is opened, and the decompression pump 84 is operated. Then, the pressure in the decompression tank 83 connected to the decompression pump 84 decreases. Thereby, a negative pressure is also generated in the discharge pipe 81. That is, in this embodiment, the decompression tank 83 and the decompression pump 84 constitute a decompression mechanism. When a negative pressure is generated in the discharge pipe 81, the gas accumulated in the vicinity of the discharge port 24 of the slit nozzle 20 is discharged to the discharge pipe 81 together with the rinse liquid. The rinse liquid and gas discharged from the slit nozzle 20 to the discharge pipe 81 are stored in the decompression tank 83.

  In order to reduce the pressure in the decompression tank 83, a vacuum generator such as a comb may be used instead of the decompression pump 84.

  The circulation mechanism 90 is a mechanism for resupplying the rinse liquid stored in the decompression tank 83 to the deaeration tank 67. The circulation mechanism 90 includes a circulation pipe 91, a sixth on-off valve 92, a second air supply source 93, a second air supply pipe 94, and a second air on-off valve 95. The upstream end of the circulation pipe 91 is connected to the bottom of the decompression tank 83. The downstream end of the circulation pipe 91 is connected to the deaeration tank 67. A sixth open / close valve 92 is provided on the path of the circulation pipe 91. The decompression tank 83 is connected to a second air supply source 93 via a second air supply pipe 94. The second air supply source 93 stores pressurized air. A second air on-off valve 95 is inserted on the path of the second air supply pipe 94.

  Therefore, when the decompression pump 84 is stopped and the sixth on-off valve 92 and the second air on-off valve 95 are opened, the second air supply source 93 passes through the second air supply pipe 94 and enters the decompression tank 83. Pressurized air is supplied. Then, the rinsing liquid in the decompression tank 83 is pushed out to the circulation pipe 91 by the pressurization in the decompression tank 67. Then, the rinse liquid is supplied again to the deaeration tank 67 through the circulation pipe 91. Instead of pressurized air, an inert gas such as pressurized nitrogen gas may be supplied into the decompression tank 83.

FIG. 5 is a block diagram showing a connection configuration between the control unit 50 and each part of the piping system. As shown in FIG. 5, the controller 50 includes the first on-off valve 63, the second on-off valve 66, the supply pump 69, the third on-off valve 71, the fourth on-off valve 72, the first air on-off valve 75, The fifth on-off valve 82, the pressure reducing pump 84, the sixth on-off valve 92 , and the second air on-off valve 95 are electrically connected to each other. The control unit 50 controls the operation of these units based on a preset computer program or an external instruction. Thereby, the coating process and the cleaning process in the coating apparatus 1 proceed.

<4. Cleaning the slit nozzle and piping>
In the coating apparatus 1, when the coating material is coated, a coating material having a high viscosity is formed in the deaeration tank 67, the main supply pipe 68, the two branch supply pipes 70, and the slit nozzle 20. Adhere to. For this reason, the coating apparatus 1 needs to perform a cleaning process after the coating process, before the next coating process, or periodically. Below, the said washing | cleaning process is demonstrated, referring the flowchart of FIG.

  When performing the cleaning process, first, the second on-off valve 66 is opened, and the rinse liquid is supplied from the rinse liquid supply source 64 to the deaeration tank 67. Thereby, the rinse liquid is stored in the deaeration tank 67 (step S1). The material to be applied adhering to the inner wall of the deaeration tank 67 is removed by dissolving in the stored rinse liquid. At this time, the first air on-off valve 75 is opened. For this reason, the inside of the deaeration tank 67 is pressurized by the air supplied from the first air supply source 73.

  Next, the control unit 50 opens the third on-off valve 71 and the fourth on-off valve 72. Then, the supply of the rinse liquid from the deaeration tank 67 to the slit nozzle 20 is started by the pressure in the deaeration tank 67 (step S2). The rinse liquid in the deaeration tank 67 is pumped to the slit nozzle 20 side through the main supply pipe 68 and the two branch supply pipes 70, and is supplied from the pair of supply ports 22 to the flow path 210 in the slit nozzle 20. The The material to be applied adhering in the main supply pipe 68 and the two branch supply pipes 70 is gradually washed away by the rinse liquid passing through the inside. Further, the material to be applied adhered in the slit nozzle 20 is also gradually washed away by the rinse liquid.

  Next, the control unit 50 starts the operation of the decompression pump 84. Thereby, a negative pressure is generated in the decompression tank 83 and the discharge pipe 81 (step S3). Then, the rinse liquid in the slit nozzle 20 flows into the discharge pipe 81 together with the gas accumulated near the discharge port 24. Thereby, gas is removed from the flow path 210 in the slit nozzle 20. Further, the inside of the discharge pipe 81 is also cleaned with the rinse liquid. Thereafter, the rinse liquid is stored in the decompression tank 83.

  FIG. 7 is a diagram showing the inside of the slit nozzle 20 after step S3. FIG. 8 is a diagram (comparative example) showing the inside of the slit nozzle 20 when the supply of the rinsing liquid is continued without operating the decompression pump 84. In the example of FIG. 8, strong pressure is applied from the rinse liquid supplied to the inside of the slit nozzle 20 to the material to be coated M that adheres so as to block the discharge port 23 of the slit nozzle 20 as indicated by a broken line arrow. For this reason, as shown in the middle and lower diagrams of FIG. 8, a part of the material to be coated M penetrates easily and the rinse liquid tends to flow downward therefrom. In this case, since the flow of the rinsing liquid concentrates on the portion through which the material to be coated M penetrates, it becomes extremely difficult to wash away other material to be coated that has adhered to the discharge port 23.

  On the other hand, in the present embodiment, as shown in FIG. 7, the rinse liquid supplied to the flow path 210 in the slit nozzle 20 flows toward the upper outlet 24 as indicated by a broken line arrow. For this reason, strong pressure is not applied to the material M to be applied, which is attached so as to close the discharge port 23 of the slit nozzle 20 from the rinse liquid supplied to the inside of the slit nozzle 20. Therefore, the surface of the material to be coated M can be totally eroded with the rinse liquid. If it does in this way, it will be difficult to be in the state where a part of coating material M penetrates. Even if a part of the material to be coated M penetrates, the concentration of the rinsing liquid on the part is suppressed by the suction to the discharge pipe 81. As a result, the material to be applied adhering to the discharge port 23 of the slit nozzle 20 can be removed evenly.

  Subsequently, the control unit 50 opens and closes the third on-off valve 71 and the fourth on-off valve 72 while continuing to supply the rinse liquid. Thereby, the flow rate of the rinse liquid is changed in the main supply pipe 68 and the two branch supply pipes 70 (step S4). When the flow rate of the rinsing liquid changes, the strength of how the rinsing liquid hits the material to be coated attached to the inner walls of these pipes is increased or decreased. In addition, the rinsing liquid can easily hit the entire inner wall of the pipe. Thereby, the to-be-coated material adhering to the inner wall of piping can be washed away efficiently. As a result, it is possible to reduce the amount of the rinsing liquid used for obtaining a desired cleanliness and to shorten the time required for cleaning.

  FIG. 9 is a time chart showing an example of the opening / closing operation of the third opening / closing valve 71 or the fourth opening / closing valve 72. In step S4, as shown in FIG. 9, the third on-off valve 71 and the fourth on-off valve 72 are repeatedly opened and closed every predetermined time. For this reason, the washing | cleaning effect by a rinse liquid can be improved more than the case where the operation | movement of closing and opening is performed only once. The interval and frequency of the opening / closing operations of the third on-off valve 71 and the fourth on-off valve 72 can be arbitrarily set according to the properties of the material to be applied and the required cleanliness.

  Thus, in this embodiment, the flow rate of the rinse liquid in the main supply pipe 68 and the two branch supply pipes 70 is changed using the third on-off valve 71 and the fourth on-off valve 72. That is, in the present embodiment, the third on-off valve and the fourth on-off valve function as a flow rate switching means. If the on-off valve is used, the flow rate of the rinsing liquid can be changed without complicating the configuration of the supply mechanism 60.

  Thereafter, the control unit 50 stops the decompression pump 84 and opens the sixth on-off valve 92 and the second air on-off valve 95. Then, the rinsing liquid stored in the decompression tank 83 is re-supplied to the deaeration tank 67 through the circulation pipe 91 due to the pressurization in the decompression tank 83 (step S5). The rinse liquid re-supplied to the degassing tank 67 is supplied to the slit nozzle 20 through the main supply pipe 68 and the two branch supply pipes 70 together with the rinse liquid newly supplied from the rinse liquid supply source 64. The Thus, in the coating apparatus 1 of this embodiment, the rinse liquid once used can be circulated and reused. Thereby, the usage-amount of a rinse liquid can be reduced significantly.

<5. Modification>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

  FIG. 10 is a diagram illustrating a configuration of a piping system in the coating apparatus 1 according to a modification. In the example of FIG. 10, a swing pump 76 is provided on the path of the main supply pipe 68. For the swing pump 76, for example, a bellows pump, a diaphragm pump, a bellows pump, or the like can be used. When the oscillating pump 76 is operated while supplying the rinse liquid from the deaeration tank 67 to the slit nozzle 20, the flow rate of the rinse liquid periodically changes inside the main supply pipe 68. For this reason, the material to be applied adhered to the inner wall of the pipe can be efficiently cleaned by increasing or decreasing the flow of the rinsing liquid without opening and closing the third on-off valve 71 and the fourth on-off valve 72.

  Thus, in the example of FIG. 10, the swing pump 76 is used as the flow rate switching means. If the swing pump 76 is used, the flow rate of the rinse liquid in the pipe can be changed to a desired value by selecting the output pressure of the swing pump 76. Therefore, the change in the flow rate of the rinsing liquid can be set to an optimum state according to the viscosity and properties of the material to be coated.

  Further, in addition to the on-off valve and the swing pump, for example, a flow rate of the rinsing liquid may be changed using a proportional electromagnetic valve whose flow rate can be adjusted. Further, the flow rate of the rinsing liquid may be changed by combining these plural means. The flow rate of the rinse liquid in the supply pipe does not necessarily have to maintain a positive flow rate toward the slit nozzle 20 side. That is, in the process in which the flow rate of the rinsing liquid changes, the rinsing liquid may temporarily return to the degassing tank 67 side.

  In the above embodiment, the material to be coated is supplied into the slit nozzle 20 from the two supply ports 22 of the slit nozzle 20. However, when the material to be coated is supplied, only one of the third on-off valve 71 and the fourth on-off valve 72 is opened, and the material to be coated is supplied into the slit nozzle 20 from only one of the two supply ports 22. Also good. When cleaning the slit nozzle 20 and the piping, both the third on-off valve 71 and the fourth on-off valve 72 are opened, and the rinse liquid is supplied into the slit nozzle 20 from both of the two supply ports 22. Good.

  In the above embodiment, the material to be coated and the rinse liquid are supplied into the slit nozzle 20 through the common supply pipes 68 and 70. However, the material to be coated and the rinsing liquid may be supplied into the slit nozzle 20 through different pipes. For example, a supply pipe for the material to be coated is separately provided in the discharge pipe 81 of the slit nozzle 20, and the material to be coated is supplied from the supply pipe into the slit nozzle 20 through the discharge pipe 81 and the discharge port 24. Also good. When the slit nozzle 20 is cleaned, the on-off valve provided in the supply pipe for the material to be coated is closed, and the third on-off valve 71 and the fourth on-off valve 72 are opened to supply a pair of supply from the branch supply pipe 70. A rinse solution may be supplied into the slit nozzle 20 through the port 22.

  In the above embodiment, the rinsing liquid is re-supplied from the depressurization tank to the deaeration tank by pressurizing the inside of the depressurization tank. A method other than pressure may be used. For example, a rinsing liquid may be circulated by providing a pump on the circulation pipe and operating the pump. In addition, a filter for removing foreign matter may be provided on the path of the circulation pipe.

  Moreover, although said coating device 1 was used for the process which manufactures the base material itself of a flexible device, the coating device of this invention forms a protective film on the surface of the base material after device formation. It may be used in a process. Moreover, the coating apparatus of this invention may be used for the manufacturing process of liquid crystal display devices other than a flexible device, or a semiconductor substrate. Moreover, the coating device of this invention may be used for the manufacturing process of batteries, such as a lithium ion secondary battery and a fuel cell.

  In addition, the details of the coating apparatus may be different from the configurations shown in the drawings of the present application. For example, in order to promote the discharge of bubbles from the slit nozzle, an inclination may be provided at the upper edge of the flow path in the slit nozzle. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

DESCRIPTION OF SYMBOLS 1 Application | coating apparatus 9 Substrate 10 Stage 20 Slit nozzle 21 Nozzle body 22 Supply port 23 Discharge port 24 Discharge port 30 Nozzle holding part 40 Traveling mechanism 50 Control part 60 Supply mechanism 61 Material supply source 62 First supply piping 63 First opening / closing Valve 64 Rinse solution supply source 65 Second supply pipe 66 Second on-off valve 67 Deaeration tank 68 Main supply pipe 69 Supply pump 70 Branch supply pipe 71 Third on-off valve 72 Fourth on-off valve 73 First air supply source 74 First Air supply piping 75 First air on-off valve 76 Oscillating pump 80 Discharge mechanism 81 Discharge piping 82 Fifth on-off valve 83 Pressure reducing tank 84 Pressure reducing pump 90 Circulation mechanism 91 Circulation piping 92 On-off valve 93 Second air supply source 94 Second air Supply pipe 95 Second air on-off valve 210 Flow path M Material to be coated

Claims (11)

A coating apparatus that applies a material to be coated, which is a fluid, to a surface to be processed,
A nozzle having a discharge port for discharging a fluid;
A supply mechanism for selectively supplying the material to be coated and a rinsing liquid having a viscosity lower than that of the material to be coated to the nozzle;
A control unit for controlling the supply mechanism;
With
The supply mechanism is
A supply pipe connected to the nozzle;
A flow rate switching means for changing the speed of the fluid in the supply pipe;
Have
In the cleaning process of cleaning the supply pipe and the nozzle with the rinse liquid , the control unit operates the flow rate switching unit to increase the speed of the rinse liquid while continuing to supply the rinse liquid with the supply mechanism. Ru is varied, the coating apparatus. The coating apparatus according to claim 1,
The flow rate switching means is a coating apparatus including an on-off valve provided on the supply pipe. The coating apparatus according to claim 1,
The flow rate switching means is a coating apparatus including a pump provided on the supply pipe. The coating apparatus according to any one of claims 1 to 3,
The said control part is a coating device which makes the said flow rate switching means operate | move repeatedly every predetermined time at the time of supply of the said rinse liquid. It is a coating device of any one of Claims 1 thru | or 4, Comprising:
A discharge pipe for discharging gas from the nozzle;
A pressure reducing mechanism for generating a negative pressure in the discharge pipe;
Further comprising
The said control part is a coating device which operates the said pressure reduction mechanism at the time of supply of the said rinse liquid. The coating apparatus according to claim 5,
The decompression mechanism has a decompression tank to which a downstream end of the discharge pipe is connected,
The rinse liquid that has flowed into the discharge pipe from the nozzle is stored in the decompression tank,
A coating apparatus, further comprising a circulation mechanism for re-supplying the rinse liquid stored in the decompression tank to the supply mechanism. The coating apparatus according to claim 5 or 6, wherein
The discharge port is a slit-like opening provided in the lower part of the nozzle,
The said discharge piping is a coating device connected to the discharge port provided in the upper part of the said nozzle. In a coating apparatus that supplies a material to be coated, which is a fluid, to a nozzle from a supply pipe and discharges it from a discharge port of the nozzle, a rinsing liquid which is a fluid having a viscosity lower than that of the material to be coated. A cleaning method for cleaning using
a) starting the supply of the rinse liquid from the supply pipe to the nozzle;
b) after the step a), changing the flow rate of the rinse liquid in the supply pipe while continuing to supply the rinse liquid;
A cleaning method. The cleaning method according to claim 8,
In the step b), a cleaning method in which the flow rate of the rinsing liquid is repeatedly changed every predetermined time. The cleaning method according to claim 8 or 9, wherein
c) A cleaning method, further comprising a step of generating a negative pressure in a discharge pipe for discharging gas from the nozzle. The cleaning method according to claim 10,
d) A cleaning method, further comprising a step of re-supplying the rinse liquid that has flowed into the discharge pipe in the step c) to the upstream side of the supply pipe.

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