JP2012206020A - Method and device for applying application liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for applying an application liquid that can precisely control an application amount of an application liquid.SOLUTION: The method for applying an application liquid includes: a first relational expression preparing step of figuring out a first relational expression expressing a flow amount indicated by a reference flow meter disposed on a main tube when an application liquid is supplied through the main tube to one branch tube among a plurality of branch tubes, and a flow rate indicated by a branch tube flow meter disposed on the branch tube; a second relational expression preparing step of figuring out a first relational expression expressing a flow rate set value of a flow rate control valve disposed on a branch tube when an application liquid is supplied through the main tube to one branch tube among a plurality of branch tubes, and a flow rate indicated by a branch tube flow meter disposed on the branch tube; a branch tube changing step of executing the first relational expression preparing step and the second relational expression preparing step sequentially for other branch tubes among the plurality of branch tubes; and an applying step of supplying the application liquid to the substrate by regulating each flow control valve of each branch tube based on the first relational expression and the second relational expression prepared for each of the branch tubes.

Description

  The present invention is a coating that applies a coating solution to a substrate such as a glass substrate for an organic EL display device, a glass substrate for a liquid crystal display device, a glass substrate for a PDP, a substrate for a solar cell, a substrate for electronic paper, or a mask substrate for a semiconductor manufacturing apparatus. The present invention relates to a liquid coating method and a coating apparatus.

  For example, when manufacturing an active matrix driving type organic EL display device using a polymer organic EL (Electro Luminescence) material, a TFT (Thin Film Transistor) circuit is formed on a glass substrate, and an ITO (anode) is used as an anode. Indium Tin Oxide) electrode forming step, partition wall forming step, flowable material coating step including hole transport material, hole transport layer forming step by heat treatment, flowable material including organic EL material coating step, An organic EL layer forming step by heat treatment, a cathode forming step, and a sealing step by forming an insulating film are sequentially performed.

  When manufacturing such an organic EL display device, the coating liquid is continuously discharged as a coating apparatus that applies a coating liquid such as a fluid material containing a hole transport material or a fluid material containing an organic EL material to a substrate. An apparatus is known in which a plurality of nozzles are moved relative to a substrate in a main scanning direction and a sub-scanning direction to apply a coating solution onto a coating region on the substrate in a stripe shape.

  By the way, in such a coating device, if there is unevenness in the coating amount of the coating liquid, display unevenness of the display device or the like is caused accordingly, so the coating amount of the coating liquid is controlled very accurately. There is a need to.

  For this reason, in Patent Document 1, a supply unit that supplies the coating liquid, a plurality of nozzles that discharge the coating liquid, and a plurality of coating liquids that are supplied from the processing liquid supply unit via the main pipe are connected to the nozzles. A branch part that divides into the branch pipe, a reference flow meter that measures the flow rate of the coating liquid that flows through the main pipe, and a flow rate of the coating liquid that flows through the branch pipes. An actual discharge flow rate and a reference flow meter in a coating apparatus comprising a plurality of branch pipe flow meters for measurement and a plurality of flow rate control valves that are arranged in the branch pipes and adjust the flow rate of the coating liquid flowing through the branch pipes. The relational expression indicating the relationship between the measured flow rate value and the relational expression indicating the relationship between the measured flow rate value of the reference flow meter and the measured flow rate value of the branch flow meter, and using these relational expressions, the flow control valve A coating apparatus is disclosed which controls the above.

JP 2009-45574 A

  Although the coating apparatus described in Patent Document 1 described above is excellent in that the flow rate of the coating liquid discharged from each nozzle can be easily managed, there is still room for improvement in the following points. That is, the flow rate control valve described above has a difference between the flow rate setting value and the actual flow rate value due to an error in individual characteristics at the time of manufacture. An error will occur between the actual flow rate value. The occurrence of such an error causes uneven film thickness of the coating liquid, thereby causing uneven brightness of the display device, resulting in a problem that the display quality is deteriorated.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a coating liquid coating method and a coating apparatus capable of accurately controlling the coating amount of a coating liquid.

  According to the first aspect of the present invention, there is provided a coating liquid reservoir that stores a coating liquid, a plurality of nozzles that discharge the coating liquid, and a coating liquid that is supplied from the coating liquid reservoir through a main pipe. A branch portion that branches to a plurality of branch pipes connected to the main pipe, a reference flow meter that is arranged in the main pipe and measures the flow rate of the coating liquid flowing through the main pipe, and each branch pipe that is arranged in the branch pipe. A plurality of branch flow meters that measure the flow rate of the flowing coating liquid, a plurality of flow control valves that are arranged in the branch pipes and that adjust the flow rate of the coating liquid that flows through the branch pipes, and the branch flow meters measure A control unit that controls the operation of each of the flow rate control valves based on the flow rate value, and a coating liquid application method in a coating apparatus that applies the coating liquid to the substrate, and is stored in the coating liquid storage unit. The plurality of branch pipes through the main pipe The flow rate value indicated by the reference flow meter arranged in the main pipe when supplied to only one of the branch pipes, and the flow rate value shown by the branch flowmeter arranged in the branch pipe supplied with the coating liquid A first relational expression creating step for obtaining a first relational expression showing a relation between the coating liquid stored in the coating liquid storage section and only one branch pipe of the plurality of branch pipes through the main pipe The second relationship showing the relationship between the flow rate setting value of the flow control valve provided in the branch pipe to which the coating liquid is supplied and the flow rate value indicated by the branch flow meter arranged to flow through the branch pipe when supplied A second relational expression creating step for obtaining a formula, the first relational formula creating step, and the second relational formula creating step for the other branch pipes among a plurality of branch pipes; Based on the first relational expression and the second relational expression created for Wherein characterized in that it comprises a coating step of supplying a coating solution to the substrate by controlling the flow control valve of each branch pipe.

  According to a second aspect of the present invention, in the first aspect of the invention according to the first aspect, in the first relational expression creating step, the coating liquid stored in the coating liquid storage section is allowed to pass through the plurality of pipes via the main pipe. The operation of supplying only one of the branch pipes is repeated a plurality of times by changing the opening of the flow control valve.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein in the second relational expression creating step, the coating liquid stored in the coating liquid storage section is passed through the main pipe. The operation of supplying only one of the plurality of branch pipes is repeated a plurality of times by changing the opening of the flow control valve.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the weight of the coating liquid that has passed through the main pipe and the current at the time before the second relational expression creating step A calibration step of performing calibration of the reference flow meter based on the flow value measured by the reference flow meter;

  The invention according to claim 5 is a coating apparatus that coats a substrate with a coating liquid, the coating liquid storing section storing the coating liquid, a plurality of nozzles discharging the coating liquid, and the coating liquid storing section. From the main pipe through the main pipe and branching parts for dividing the coating liquid to a plurality of branch pipes connected to the nozzle, and the flow rate of the coating liquid disposed in the main pipe and flowing through the main pipe A reference flow meter, a plurality of branch flow meters each of which is arranged in the branch pipe and measures the flow rate of the coating liquid flowing through the branch pipes, and a coating liquid which is arranged in the branch pipe and flows through the branch pipes. A plurality of flow control valves for adjusting the flow rate, and a control unit for controlling the operation of each flow rate control valve based on the flow rate value measured by each branch flow meter, wherein the control unit is the main pipe The coating solution supplied to the single branch selected from the plurality of branch pipes The flow rate value indicated by the reference flow meter measured in a state where the supply of the coating liquid to the other branch pipe is closed and the branch flow meter provided in the branch pipe to which the coating liquid is supplied A first relational expression indicating a relationship with a flow value indicated by the flow rate, a flow rate setting value of a flow control valve provided in the branch pipe to which the coating liquid is supplied, and a branch flow meter disposed to flow through the branch pipe. The flow rate control valve is controlled based on a second relational expression indicating a relationship with the flow rate value shown.

  The invention according to claim 6 is the invention according to claim 5, wherein the calibration branch pipe branched from the branch portion, the on-off valve disposed in the calibration branch pipe, and the coating supplied to the main pipe The liquid is supplied only to the calibration branch and the supply of the coating liquid to the other branch is closed, and the container that receives the coating liquid discharged from the calibration branch, the container and the container are stored therein. An electronic balance for measuring the weight of the coating solution, and a reference flow rate calibration mechanism for calibrating the reference flow meter.

  According to the first and fifth aspects of the present invention, it is possible to control the coating amount of the coating liquid very accurately even when there are individual differences in the branch flowmeters.

  According to the invention described in claim 2, it is possible to make the first relational expression more accurate.

  According to the third aspect of the invention, the second relational expression can be made more accurate.

  According to the fourth and sixth aspects of the invention, the flow rate of the coating liquid applied from each branch can be accurately controlled by calibrating the reference flow meter.

It is a top view of the coating device concerning this invention. It is a front view of the coating device concerning this invention. 4 is a cross-sectional view of the vicinity of a slider 31 in the head moving mechanism 21. FIG. It is a block diagram which shows the main control systems of the coating device which concerns on this invention. 3 is a schematic diagram showing a configuration of a coating liquid supply unit 24 and a connection relationship between the coating liquid supply unit 24 and a plurality of nozzles 23 in the coating head 20. FIG. 3 is a schematic diagram of a calibration unit 52. FIG. It is a flowchart which shows each process of the coating liquid coating method which concerns on this invention. 3 is a flowchart showing a calibration process of a reference flow meter 42. It is explanatory drawing which shows the weight measurement operation | movement of a coating liquid. It is a flowchart which shows a 1st relational expression preparation process. It is a graph which shows the relationship between the flow value F which the reference | standard flow meter 42 shows, and the flow value f which the branch pipe flow meter 45 shows. It is a flowchart which shows the 2nd relational expression preparation process. 4 is a graph showing a relationship between a flow rate setting value x of a flow rate control valve 44 and a flow rate value f indicated by a branch flow meter 45.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a coating apparatus according to the present invention, and FIG. 2 is a front view thereof.

  This coating apparatus is for coating a coating solution on a rectangular glass substrate 100. More specifically, the coating apparatus includes a glass substrate 100 for an active matrix driving type organic EL (Electro Luminescence) display device, a volatile solvent (in this embodiment, an aromatic organic solvent), and This is for applying a coating liquid containing an organic EL material as a light emitting material.

  This coating apparatus includes a substrate moving mechanism 11 for moving the glass substrate 100. As shown in FIG. 2, the substrate moving mechanism 11 includes a substrate holding unit 10 that holds the glass substrate 100 from its back surface. The substrate holding unit 10 is supported by a base 13 that moves along a pair of rails 12 and a turntable 14 disposed on the base 13. For this reason, this board | substrate holding | maintenance part 10 can move in parallel with the surface of the glass substrate 100 in the Y direction shown in FIG. This Y direction is a direction orthogonal to the main scanning direction (X direction in FIG. 1) which is the reciprocating direction of the coating head 20. Hereinafter, this Y direction is also referred to as “sub-scanning direction”. The substrate holding unit 10 is rotatable about an axis that faces in the vertical direction (Z direction in FIG. 1).

  The substrate holding unit 10 includes a heater for heating the glass substrate 100 from below. On the surface of the glass substrate 100, a plurality of application regions each extending in the X direction are arranged and formed in the Y direction at a pitch of, for example, 100 to 150 μm. This application region is formed by, for example, partition walls arranged in the X direction.

  In addition, the coating apparatus includes a pair of left and right imaging units 15 for imaging and detecting an alignment mark (not shown) formed on the glass substrate 100 and imaging a coating locus by the coating head 20. Each of the pair of imaging units 15 is provided with a CCD camera. In addition, the coating apparatus includes a pair of left and right test coating stage units 16 used for the trial coating of the coating locus. In this coating apparatus, a configuration is adopted in which the feed control of the coating head 20 is adjusted using a coating locus applied on the test coating stage unit 16 on a trial basis.

  The coating head 20 that discharges the coating liquid toward the surface of the glass substrate 100 held by the substrate holding unit 10 is moved in the main scanning direction (parallel to the surface of the glass substrate 100) along the guide unit 22 by the head moving mechanism 21. It is reciprocated in the X direction in FIG. In the coating head 20, a plurality of nozzles 23 for continuously discharging the same type of coating liquid are disposed at equal intervals in the sub-scanning direction. In FIG. 1 and FIG. 2, only five nozzles 23 are illustrated for convenience of illustration, but the number of nozzles 23 is further increased.

  The coating head 20 is connected to a coating liquid supply unit 24 and an air supply source 25 via a supply pipe group 26 that includes an air supply pipe and a plurality of branch pipes described later. On both sides of the substrate holding unit 10 with respect to the reciprocating movement direction (X direction) of the coating head 20, two liquid receiving portions 17 and 18 that receive the coating liquid from the nozzles 23 in the coating head 20 are disposed. Further, a nozzle pitch adjusting mechanism 19 for adjusting the pitch of the plurality of nozzles 23 in the sub-scanning direction is arranged on the side of one liquid receiving unit 18 in the reciprocating movement direction (X direction) of the coating head 20. It is installed.

  FIG. 3 is a sectional view of the vicinity of the slider 31 in the head moving mechanism 21.

  A slider 31 is slidably disposed on the guide member 22 in the head moving mechanism 21 shown in FIG. A through hole 32 through which the guide member 22 passes is formed in the slider 31. As shown in FIG. 1, air of a constant pressure is supplied to the slider 31 from an air supply source 25 through an air supply pipe included in the supply pipe group 26. For this reason, as shown in FIG. 3, air is jetted between the inner peripheral surface of the through hole 32 and the outer peripheral surface of the guide portion 22. In FIG. 3, the air ejection direction is indicated by an arrow denoted by reference numeral A <b> 1. Thereby, the slider 31 is supported so as to be movable in the main scanning direction while being engaged with the guide portion 22 in a non-contact state.

  Referring to FIG. 1, a pair of pulleys 33 that are rotatable around an axis that faces the Z-axis direction are disposed near both ends of the guide portion 22. An endless synchronous belt 34 is wound around the pair of pulleys 33. One end of the slider 31 is fixed to the synchronization belt 34. On the other hand, the application head 20 described above is fixed to the other end of the slider 31. Therefore, the application head 20 can be reciprocated in the (−X) direction or the (+ X) direction by rotating the synchronous belt 34 clockwise or counterclockwise by driving a motor (not shown). At this time, since the slider 31 can be supported in a non-contact state with respect to the guide portion 22 by the action of the gas described above, the reciprocating movement of the coating head 20 can be made fast and smooth. .

  In this coating apparatus, the head moving mechanism 21 becomes a main scanning direction moving mechanism for moving the coating head 20 in the main scanning direction, and the substrate moving mechanism 11 moves in the sub scanning direction for moving the substrate holding portion in the sub scanning direction. It becomes a mechanism. In this coating apparatus, each time the movement of the coating head 20 in the main scanning direction is completed, the glass substrate 100 is moved in the sub-scanning direction, whereby the coating liquid is applied to the coating region on the surface of the glass substrate 100. Execute. During main scanning of the coating head 20, acceleration or deceleration is completed in the vicinity of the liquid receiving portions 17 and 18, and the coating head 20 is, for example, at a constant speed of about 3 to 5 m per second above the glass substrate 100. Move with.

  In the coating apparatus having the above-described configuration, when the application of the coating liquid is started, the glass substrate 100 is first held by the substrate holding unit 10. And the alignment mark formed in the glass substrate 100 by the imaging part 15 is detected, the substrate holding | maintenance part 10 moves and rotates based on the detection result, and the glass substrate 100 is in the application | coating start position shown as a continuous line in FIG. Be placed. In this state, discharge of the coating liquid is started from the plurality of nozzles 23 in the coating head 20 and the coating head 20 is moved in the main scanning direction by the head moving mechanism 21.

  Then, the coating liquid is continuously discharged from each of the plurality of nozzles 23 toward the surface of the glass substrate 100 at a constant flow rate, and the coating head 20 continuously moves at a constant speed in the main scanning direction. Then, the coating liquid is applied in stripes to a plurality of linear regions in the coating region of the glass substrate 100.

  In this manner, the coating head 20 moves to the standby position facing the liquid receiving unit 18 indicated by a two-dot chain line in FIGS. 1 and 2, thereby forming a stripe pattern by the coating liquid. When the coating head 20 moves to the standby position, the substrate moving mechanism 11 is driven, and the glass substrate 100 moves in the sub-scanning direction together with the substrate holding unit 10. At this time, in the coating head 20, the coating liquid is continuously discharged from the plurality of nozzles 23 toward the liquid receiving unit 18.

  The above operation is continued until the necessary application operation is completed. When the glass substrate 100 moves to the application end position, the discharge of the application liquid from the plurality of nozzles 23 is stopped, and the application operation of the application liquid to the glass substrate 100 by the application apparatus is completed. The glass substrate 100 that has been coated is transported to another coating apparatus or the like, and coating liquids of two colors other than the coating liquid coated by the coating apparatus are coated. And after a predetermined application | coating process is performed with respect to the glass substrate 100, it combines with another component and an organic electroluminescent display apparatus is manufactured.

  FIG. 4 is a block diagram showing a main control system of the coating apparatus according to the present invention.

  The coating apparatus includes a control unit 60 that controls the entire apparatus. The controller 60 is connected to the substrate moving mechanism 11, the turntable 14, and the head moving mechanism 21 described above. The control unit 60 is connected to the flow rate control valve 40, the reference flow meter 42, the flow rate control valve 44, the branch flow meter 45, the open / close valve 46, the open / close valve 51, and the calibration unit 52 in the coating liquid supply unit 24. . Although not shown, the control unit 60 includes a storage unit including a RAM and a ROM for executing various operations described later, and a calculation unit including a CPU. As the control unit 60, a general personal computer may be used, or the control unit may be configured by a printed circuit board or the like. The configurations of the reference flow meter 42, the flow control valve 44, the branch flow meter 45, the open / close valve 46, the open / close valve 51, the calibration unit 52, and the like will be described later.

  Next, the configuration of the coating liquid supply mechanism, which is a characteristic part of the present invention, will be described. FIG. 5 is a schematic diagram illustrating the configuration of the coating liquid supply unit 24 and the connection relationship between the coating liquid supply unit 24 and the plurality of nozzles 23 in the coating head 20.

  The coating liquid supply section 24 in the coating apparatus according to the present invention includes a flow control valve 40, a coating liquid storage section 41, a reference flow meter 42, a manifold 43 as a branch section, and a plurality of flow control valves 44a and 44b. 44n, a plurality of branch flow meters 45a, 45b, 45c,... 45n, a plurality of on-off valves 46a, 46b, 46c,... 46n, an on-off valve 51, and a calibration unit 52, which will be described later. Is provided. Each of the open / close valves 46a, 46b, 46c,... 46n is connected to a plurality of nozzles 23a, 23b, 23c,.

  In this specification, a plurality of flow control valves 44a, 44b, 44c... 44n are collectively referred to as a flow control valve 44 and a plurality of branch flow meters 45a, 45b, 45c. 45n is a collective term for the branch pipe flow meter 45, a plurality of on-off valves 46a, 46b, 46c... 46n is a collective term for the on-off valve 46, and a plurality of nozzles 23a, 23b, 23c. 23.

  Further, in this specification, a pipe line before branching from the coating liquid reservoir 41 to the manifold 43 via the flow rate control valve 40 and the reference flow meter 42 is referred to as a main pipe. In this specification, each flow control valve 44a, 44b, 44c ... 44n, each branch flow meter 45a, 45b, 45c ... 45n, each opening / closing valve 46a, 46b, 46c ... A branched pipe line that reaches each nozzle 23a, 23b, 23c,..., 23n through 46n is called a branch pipe. In this coating apparatus, there are a plurality of branch pipes corresponding to a to n. Furthermore, in this specification, a pipe line extending from the manifold 43 to the calibration unit 52 via the opening / closing valve 51 is referred to as a calibration branch pipe.

  The coating liquid storage unit 41 has a configuration in which a flexible bag-like container storing the coating liquid is stored in an airtight chamber, and the flow rate control valve 40 controls the coating liquid by supplying pressurized air into the airtight chamber. In addition, it has a configuration in which it is pumped toward the reference flow meter 42, the manifold 43 and the like. The reference flow meter 42 has a configuration for measuring the flow rate of the coating liquid discharged from the coating liquid storage unit 41 and flowing into the manifold 43. The reference flow meter 42 is a thermal flow meter that measures the flow rate of the coating liquid using a heater and a temperature sensor provided in the flow path of the coating liquid. The measurement value of the flow rate by the reference flow meter 42 is transmitted to the control unit 60 shown in FIG.

  Each flow control valve 44 receives a command from the control unit 60 shown in FIG. 4 and adjusts the flow rate of the coating liquid flowing through each branch pipe. Each branch flow meter 45 measures the flow rate of the coating liquid flowing through each branch pipe. As the branch flow meter 45, a thermal flow meter that measures the flow rate of the coating liquid using a heater and a temperature sensor is used as in the reference flow meter 42. The measured value of the flow rate by this branch flow meter 45 is transmitted to the control unit 60 shown in FIG. The flow control valve 44 and the branch pipe flow meter 45 constitute a mass flow controller. Furthermore, each open / close valve 46 receives a command from the control unit 60 shown in FIG. 4 and opens or closes the flow path of each branch pipe. Similarly, the open / close valve 51 receives a command from the control unit 60 shown in FIG. 4 and opens or closes the flow path of the calibration branch pipe from the manifold 43 to the calibration unit 52.

  FIG. 6 is a schematic diagram of the calibration unit 52 described above.

  The calibration unit 52 includes a container 53 in which a coating solution is stored in advance. The container 53 is placed on an electronic balance 54 disposed on a support portion 59 of the coating apparatus. The electronic balance 54 and the container 53 are accommodated in a chamber 55. A lid 56 is disposed on the top of the container 53. The lid 56 is connected to the chamber 55 via a connecting member 58 and is disposed at a position separated from the upper end of the container 53 by a slight distance. The tip of the calibration branch pipe from the on-off valve 51 shown in FIG. 5 to the calibration section 52 is connected to a metal thin tube 57. As shown in FIG. 6, the metal thin tube 57 penetrates into the container 53 through the chamber 55 and the lid 56. The tip of the thin tube 57 is immersed in the coating solution stored in the container 53. In this figure, symbol L indicates the liquid level of the coating liquid stored in the container 53 before performing a calibration operation described later, and symbol H indicates the coating when the coating liquid is stored in the container 53 to the limit. The liquid level of the liquid is shown. The electronic balance 54 measures the weight of the container 53 and the coating liquid stored therein.

  Next, the application | coating operation | movement of the coating liquid by the coating device which has the above structures is demonstrated. FIG. 7 is a flowchart showing each step of the coating liquid coating method according to the present invention.

  First, the reference flow meter 42 is calibrated (step S1).

  FIG. 8 is a flowchart showing the calibration process of the reference flow meter 42. Calibration of the reference flow meter 42 is executed in the process shown in FIG.

  That is, first, the opening / closing valve 51 shown in FIG. 4 is opened. At this time, pressurized air having a predetermined pressure is supplied to the coating liquid storage section 41, and the coating liquid can be fed toward the manifold 43 via the flow control valve 40 and the reference flow meter 42. Yes. The open / close valve 46 in each branch pipe is closed in advance. As a result, the coating liquid is pumped from the coating liquid storage unit 41 toward the calibration unit 52 via the flow rate control valve 40, the reference flow meter 42, the manifold 43, and the opening / closing valve 51. Then, in the calibration unit 52 shown in FIG. 6, the pumped coating solution is discharged from the metal thin tube 57 into the coating solution in the container 53 (step S11).

  Then, the flow value indicated by the reference flow meter 42 when the coating liquid is discharged into the container 53 is acquired (step S12). This flow value is transmitted to the control unit 60 shown in FIG. Further, the weight of the coating solution discharged into the container 53 is measured by the electronic balance 54 (step S13). The weight of the discharged coating liquid includes the total value of the weight of the container 53 measured by the electronic balance 54 before discharging the coating liquid and the coating liquid previously stored therein, and the electronic balance after discharging the coating liquid. It is measured by the difference between the container 53 measured by 54 and the total weight of the coating liquid stored therein. The measured weight of the discharged coating liquid is transmitted from the calibration unit 52 to the control unit 60 shown in FIG.

  FIG. 9 is an explanatory view showing the operation of measuring the weight of the coating liquid at this time.

  In this case, after waiting time t0 of about 5 seconds from the start of discharge until the discharge amount becomes stable, for example, by measuring the change in weight dw per unit time dt of about 1 second. Then, the weight (dw / dt) of the coating solution that flows per unit time is measured. This is repeated 10 times, for example, and 10 pieces of data obtained in 10 seconds are averaged to obtain data on the weight of the coating liquid that has flowed per unit time. Then, such an operation is performed a necessary number of times, for example, about 3 to 5 times by changing the flow rate control valve 40 to change the flow rate value (step S14). Here, w0 in FIG. 9 indicates an initial weight that is a total value of the weights of the container 53 and the coating liquid first stored therein.

  Note that the unit time dt may be about 5 seconds instead of about 1 second as described above, and 10 data may be obtained in 50 seconds. In this case, more accurate weight can be measured in consideration of the responsiveness of the electronic balance 54. However, it takes a long time to measure the weight, and the amount of the coating solution to be consumed increases. Further, the above operation may be executed more times than 3 to 5 times by changing the flow rate of the coating liquid. Even in this case, the measurement accuracy is improved, but the measurement time and the consumption of the coating liquid are increased.

  Next, calibration is executed (step S15). That is, based on the weight of the coating liquid flowing per unit time and the specific gravity of the coating liquid measured using the electronic balance 54 by the control unit 60 shown in FIG. Calculate the actual flow rate. Then, the actual flow rate is compared with the flow rate value indicated by the reference flow meter 42. Thereafter, the reference flow meter 42 is adjusted so that the flow value indicated by the reference flow meter 42 matches the actual flow value. Thereby, the flow value indicated by the reference flow meter 42 can be matched with the actual flow value of the coating liquid.

  Referring to FIG. 7 again, next, after one branch pipe is selected from the plurality of branch pipes (step S2), the reference flow meter 42 is set when the coating liquid is supplied only to the one branch pipe. A first relational expression creating step (step S3) for obtaining a first relational expression showing a relationship between the flow rate value shown and the flow rate value shown by the branch flowmeter 45 of the branch pipe supplied with the coating liquid; A second relationship showing the relationship between the flow rate setting value of the flow rate control valve 44 of the branch pipe to which the coating liquid is supplied when supplied to only one branch pipe and the flow rate value indicated by the branch flow meter 45 disposed in the branch pipe. A second relational expression creating step (step S4) for obtaining an expression is executed.

  FIG. 10 is a flowchart showing the first relational expression creation process. The first relational expression creating step is executed in the step shown in FIG.

  That is, first, the flow rate of the coating liquid is set (step S31). In this case, under the control of the control unit 60, the flow control valve 44 of the branch pipe is adjusted so that the flow value indicated by the branch pipe flow meter 45 of the selected branch pipe becomes a preset target value. Then, the opening / closing valve 46 of the selected branch pipe is opened by a command from the control unit 60. At this time, the open / close valve 46 of the branch pipe other than the selected branch pipe is closed.

  In this state, the coating liquid is sent from the coating liquid storage unit 41 to the nozzle 23 via the reference flow meter 42, the manifold 43, the flow control valve 44 of the selected branch pipe, the branch flow meter 45, and the opening / closing valve 46. Then, the coating liquid is discharged (step S32). Then, the flow value measured by the reference flow meter 42 at this time is acquired (step S33), and the flow value measured by the branch flow meter 45 of the selected branch pipe is acquired (step S34). These acquired flow rate values are transmitted to the control unit 60.

  Then, the flow rate of the coating liquid is set again (step S31) until necessary processing is completed (step S35). That is, under the control of the control unit 60, the flow value indicated by the branch flow meter 45 of the selected branch pipe is a value corresponding to the flow value of the coating liquid when the coating liquid is actually applied to the glass substrate 100, and The flow rate control valve 44 of the branch pipe is adjusted so that the flow rate value is different from the flow rate value in the previous coating liquid discharge step (step S32). Then, the above-described coating liquid discharge step (step S32), the flow rate value acquisition step of the reference flow meter (step S33), and the flow rate value acquisition step of the branch flow meter (step S34) are repeatedly executed.

  That is, the relationship between the flow value indicated by the reference flow meter 42 and the flow value indicated by the branch flow meter 45 is a plurality of points close to the flow value of the coating liquid when the coating liquid is actually applied to the glass substrate 100 (for example, 3-5 points). For example, when the flow rate target value is set to 100, the same operation is performed on the flow rate values near the target value, such as 80%, 90%, 110%, and 120%. For this reason, the flow rate setting step (step S31), the coating liquid discharge step (step S32), the reference flow meter flow value acquisition step (step S33), and the branch flow meter flow value acquisition step (step S34) are plural. Repeated times.

  In this case, the relationship between the flow rate value indicated by the reference flow meter 42 and the flow rate value indicated by the branch flow meter 45 may be obtained at more points than 3 to 5 points. In this case, what is necessary is just to select suitably by not only the range of 80%-120% as mentioned above but the required flow range, such as 50%-200%.

  When the necessary flow value is acquired (step S35), the relationship between the flow value indicated by the reference flow meter 42 and the flow value indicated by the branch flow meter 45 of the branch pipe to which the coating liquid is supplied is shown. One relational expression is created (step S36).

  FIG. 11 is a graph showing the relationship between the flow value F indicated by the reference flow meter 42 and the flow value f indicated by the branch flow meter 45.

  In the graph shown in FIG. 11, the relationship between the flow value F indicated by the reference flow meter 42 and the flow value f indicated by the branch flow meter 45 is plotted at three points, and an approximate curve passing through these three points (in this embodiment, in this embodiment). (Straight line) is obtained as a first relational expression showing the relationship between the flow value indicated by the reference flow meter 42 and the flow value indicated by the branch flow meter 45 of the branch pipe to which the coating liquid is supplied. This first relational expression is derived using, for example, the least square method. This first relational expression is represented by the following expression (1), where A and B are coefficients.

F = A * f + B (1)
The first relational expression is not limited to the linear expression as described above. The relationship between the flow value indicated by the reference flow meter 42 and the flow value indicated by the branch flow meter 45 of the branch pipe to which the coating liquid is supplied may be approximated by a curve. Further, a plurality of linear approximations may be performed by increasing the measurement points.

  FIG. 12 is a flowchart showing the second relational expression creation process. The second relational expression creating step is executed in the step shown in FIG.

  That is, first, the flow rate of the coating liquid is set (step S41). In this case, under the control of the control unit 60, the flow control valve 44 of the branch pipe is adjusted so that the flow value indicated by the branch pipe flow meter 45 of the selected branch pipe becomes a preset target value. Then, the opening / closing valve 46 of the selected branch pipe is opened by a command from the control unit 60. At this time, the open / close valve 46 of the branch pipe other than the selected branch pipe is closed.

  In this state, the coating liquid is sent from the coating liquid storage unit 41 to the nozzle 23 via the reference flow meter 42, the manifold 43, the flow control valve 44 of the selected branch pipe, the branch flow meter 45, and the opening / closing valve 46. The coating liquid is then discharged (step S42). The flow rate setting value of the flow rate control valve 44 at this time is acquired (step S43), and the flow rate value indicated by the branch flow meter 45 at that time is acquired (step S44). The obtained flow rate setting value of the flow rate control valve 44 and the flow rate value indicated by the branch flow meter 45 are transmitted to the control unit 60.

  Then, the flow rate of the coating solution is set again (step S41) until the necessary processing is completed (step S45). That is, under the control of the control unit 60, the flow rate value indicated by the branch flow meter 45 of the selected branch tube is set to a flow rate value different from the flow rate value in the previous coating liquid discharge step (step S42). The flow control valve 44 is adjusted. And the coating liquid discharge process (step S42) mentioned above, the flow volume setting value acquisition process (step S43), and the actual flow volume value acquisition process (step S44) are repeatedly performed.

  That is, the relationship between the flow rate setting value of the flow rate control valve 44 and the flow rate value indicated by the branch flow meter 45 at that time is a plurality close to the flow rate value of the coating liquid when the coating liquid is actually applied to the glass substrate 100. It is calculated | required by a point (for example, 3-5 points). For example, when the flow rate target value is set to 100, the same operation is performed on the flow rate values near the target value, such as 80%, 90%, 110%, and 120%. For this reason, the flow rate setting step (step S41), the coating liquid discharge step (step S42), the flow rate set value acquisition step (step S43), and the flow rate value acquisition step (step S44) of the branch flow meter 45 are repeated a plurality of times. It is.

  In this case as well, the relationship between the flow rate setting value of the flow rate control valve 44 and the flow rate value indicated by the branch flow meter 45 at that time may be obtained at more points than 3 to 5 points. Also in this case, it may be appropriately selected depending on the required flow rate range such as 50% to 200% as well as 80% to 120% as described above.

  When the necessary flow rate setting value of the flow control valve 44 and the flow rate value indicated by the branch flow meter 45 are acquired (step S45), the flow rate setting value of the flow rate control valve 44 of the branch pipe to which the coating liquid is supplied and A second relational expression indicating the relationship with the flow rate value indicated by the branch pipe flow meter 45 disposed in the branch pipe is created (step S46).

  FIG. 13 is a graph showing the relationship between the flow rate setting value x of the flow rate control valve 44 and the flow rate value f indicated by the branch flow meter 45.

  In the graph shown in FIG. 13, the relationship between the flow rate setting value x of the flow rate control valve 44 and the flow rate value f indicated by the branch flow meter 45 is plotted at three points, and an approximate curve passing through these three points (in this embodiment) A straight line) indicates the relationship between the flow rate setting value x of the flow control valve 44 of the branch pipe supplied with the coating liquid and the flow rate value f indicated by the branch pipe flow meter 45 of the branch pipe supplied with the coating liquid. It is calculated as a relational expression. This second relational expression is also derived using, for example, the least square method. This second relational expression is expressed by the following expression (2), where C and D are coefficients.

x = Cf + D (2)
This second relational expression is not limited to the linear expression as described above. The relationship between the flow rate setting value of the branch pipe supplied with the coating liquid and the flow rate value indicated by the branch flow meter of the branch pipe supplied with the coating liquid may be approximated by a curve. Further, a plurality of linear approximations may be performed by increasing the measurement points.

  In the embodiment described above, for convenience of explanation, in the second relational expression creating process (step S2), the flow rate setting process (step S31) and the coating liquid discharging process (step in the first relational expression creating process (step S3)). The same flow rate setting process (step S41) and coating liquid discharging process (step S42) as in S32) are executed. However, these steps may be completed at once. That is, after executing the flow rate setting step (step S31) and the coating liquid discharge step (step S32) in the first relational expression creation step (step S3), the flow rate value acquisition step (step S33) of the reference flow meter 42, the branch flow rate The flow rate value acquisition step (step S34) of the total 45 and the flow rate setting value acquisition step (step S43) of the flow rate control valve 44 may be executed in parallel.

  Referring to FIG. 7 again, if the first relational expression and the second relational expression are obtained by the above steps, the next different branch pipe is selected (step S2), and the first relational expression creating step (step S3). ) And the second relational expression creating step (step S4) are executed (step S5).

  And if the 1st relational expression and the 2nd relational expression are calculated | required about all the branch pipes by the above process (step S5), the adjustment process of the flow control valve 44 will be performed (step S6). In this case, the following formula (3) is obtained by substituting f in the above formula (1) into the formula (2).

x = (C / A) * (F−B) + D (3)
After adjusting the flow rate control valve 44 based on the equation (3), the coating liquid is applied to the glass substrate 100 (step S7). At this time, the calibration of the reference flow meter 42 has been completed in the previous reference flow meter calibration step (step S1), and the flow rate setting value of the flow control valve 44 and the branch pipe in the second relational expression creating step (step S4). Since the relationship with the flow rate value indicated by the flow meter 45 is corrected, the coating operation can be performed by discharging the coating liquid at an accurate flow rate.

  The above-described calibration process (step S1) of the reference flow meter 42 and the first and second relational expression creation processes (steps S2 to S5) for each branch pipe are executed every time the coating liquid is applied. There is no need. These steps may be executed only when necessary, for example, when the type of the coating liquid is changed or when the coating operation is performed for a certain period.

  Moreover, in embodiment mentioned above, when performing the 1st, 2nd relational expression preparation process (step S2-step S5) for every branch pipe, a coating liquid is supplied via the flow control valve 40 or the reference | standard flow meter 42. FIG. Although it supplies to each branch pipe, you may arrange | position the exclusive bypass line for supplying a coating liquid to each branch pipe in the application | coating liquid application process.

DESCRIPTION OF SYMBOLS 10 Substrate holding part 11 Substrate moving mechanism 12 Rail 13 Base 14 Rotating table 15 Imaging part 16 Test application stage part 17 Liquid receiving part 18 Liquid receiving part 19 Nozzle pitch adjusting mechanism 20 Coating head 21 Head moving mechanism 22 Guide part 23 Nozzle 24 Coating liquid supply section 25 Air supply source 31 Slider 32 Through hole 33 Pulley 34 Synchronous belt 40 Flow control valve 41 Coating liquid storage section 42 Reference flow meter 43 Manifold 44 Flow control valve 45 Branch flow meter 46 Open / close valve 51 Open / close valve 52 Calibration section 53 Container 54 Electronic Balance 55 Chamber 56 Lid 57 Metal Thin Tube 60 Control Unit 100 Glass Substrate

Claims (6)

A coating liquid storage section that stores the coating liquid, a plurality of nozzles that discharge the coating liquid, and a coating liquid that is supplied from the coating liquid storage section via the main pipe is divided into a plurality of branch pipes connected to the nozzle A branching section, a reference flow meter that measures the flow rate of the coating liquid that flows in the main pipe and that flows in the main pipe, and measures the flow rate of the coating liquid that flows in each of the branch pipes that is arranged in the branch pipe. Based on a plurality of branch flow meters, a plurality of flow control valves that are respectively disposed on the branch pipes and adjust flow rates of the coating liquid that flows through the branch pipes, and flow rates measured by the branch pipe flow meters, A control unit for controlling the operation of the flow rate control valve, and a coating liquid coating method in a coating apparatus for coating the substrate with the coating liquid,
A flow rate value indicated by a reference flow meter disposed in the main pipe when the coating liquid stored in the coating liquid storage section is supplied to only one branch pipe of the plurality of branch pipes through the main pipe. And a first relational expression creating step for obtaining a first relational expression showing a relation between a flow rate value indicated by a branch flowmeter disposed in the branch pipe supplied with the coating liquid,
Flow rate control provided in the branch pipe to which the coating liquid is supplied when the coating liquid stored in the coating liquid storage section is supplied to only one branch pipe of the plurality of branch pipes through the main pipe. A second relational expression creating step for obtaining a second relational expression indicating a relation between a flow rate setting value of the valve and a flow rate value indicated by a branch flow meter disposed in the branch;
A branch change step for sequentially executing the first relational expression creating step and the second relational expression creating step for other branch pipes among a plurality of branch pipes;
Based on the first relational expression and the second relational expression created for each branch pipe, an application step of controlling the flow rate control valve of each branch pipe and supplying a coating liquid to the substrate;
A coating liquid coating method comprising: In the coating liquid coating method according to claim 1,
In the first relational expression creating step,
The operation of supplying the coating liquid stored in the coating liquid reservoir to only one of the plurality of branch pipes through the main pipe is repeated a plurality of times by changing the opening of the flow control valve. Coating liquid coating method. In the coating liquid coating method according to claim 1 or 2,
In the second relational expression creating step,
The operation of supplying the coating liquid stored in the coating liquid reservoir to only one of the plurality of branch pipes through the main pipe is repeated a plurality of times by changing the opening of the flow control valve. Coating liquid coating method. In the coating liquid coating method according to any one of claims 1 to 3,
Calibration step of performing calibration of the reference flow meter based on the weight of the coating liquid that has passed through the main pipe and the flow rate value measured by the reference flow meter at that time before the second relational expression creating step A coating liquid coating method comprising: A coating apparatus for applying a coating liquid to a substrate,
A coating solution reservoir for storing the coating solution;
A plurality of nozzles for discharging the coating liquid;
A branching portion for diverting the coating liquid supplied from the coating liquid reservoir through the main pipe to a plurality of branch pipes connected to the nozzle;
A reference flow meter which is disposed in the main pipe and measures the flow rate of the coating liquid flowing through the main pipe;
A plurality of branch flow meters each disposed in the branch pipe and measuring the flow rate of the coating liquid flowing through the branch pipes;
A plurality of flow rate control valves that are respectively disposed on the branch pipes and adjust the flow rate of the coating liquid flowing through the branch pipes;
A controller that controls the operation of each flow control valve based on the flow value measured by each branch flow meter, and
The control unit measures the coating liquid supplied to the main pipe in a state where the supply liquid is supplied only to a single branch pipe selected from the plurality of branch pipes and the supply of the coating liquid to the other branch pipes is closed. A first relational expression indicating a relationship between a flow value indicated by the reference flow meter and a flow value indicated by a branch flow meter provided in the branch pipe to which the coating liquid is supplied; and the coating liquid is supplied. Application for controlling the flow rate control valve based on a second relational expression showing a relationship between a flow rate setting value of the flow rate control valve provided in the branch pipe and a flow rate value indicated by the branch flow meter arranged in the branch pipe apparatus. The coating apparatus according to claim 5, wherein
A calibration branch branched from the branch,
An on-off valve disposed in the calibration branch;
A container for receiving the coating liquid discharged from the calibration branch pipe while the coating liquid supplied to the main pipe is supplied only to the calibration branch pipe and the supply of the coating liquid to the other branch pipes is closed; ,
An electronic balance for measuring the weight of the container and the coating liquid stored therein; and
With
A coating apparatus comprising a reference flow rate calibration mechanism for calibrating the reference flow meter.

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