TWI458023B - Coating liquid coating method and coating apparatus - Google Patents

Description

Coating liquid coating method and coating device

The present invention relates to a coating liquid applied to a glass substrate for an organic electroluminescence (EL) electroluminescence display device, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display panel (PDP), and a sun. A coating liquid application method and a coating device for a substrate for a battery, a substrate for an electronic paper, or a substrate for a semiconductor manufacturing device.

For example, in the production of an organic EL display device using an active matrix driving method using a polymer organic EL (Electro Luminescence) material, the glass substrate is sequentially subjected to a step of forming a thin film transistor (TFT) circuit; a step of forming an indium tin oxide (ITO) electrode; a step of forming a separator; a coating step of a fluid material comprising a hole transporting material; a step of forming a hole transporting layer by heat treatment; a coating step of a fluid material of the EL material; a step of forming an organic EL layer by heat treatment; a step of forming a cathode; and a sealing step by formation of an insulating film.

In the case of producing such an organic EL display device, a coating device for applying a coating liquid containing a fluid material including a hole transporting material or a fluid material containing an organic EL material to a substrate is known as follows: The plurality of nozzles that continuously discharge the coating liquid are relatively moved in the main scanning direction and the sub-scanning direction with respect to the substrate, whereby the coating liquid is applied to the substrate in a stripe shape. Coating area.

In addition, in such a coating apparatus, when the coating amount of the coating liquid is not uniform, display unevenness of the display device may occur, and therefore it is necessary to control the coating amount of the coating liquid extremely accurately.

Therefore, Patent Document 1 discloses a coating apparatus including a supply unit that supplies a coating liquid, a plurality of nozzles that discharge a coating liquid, and a branch portion that supplies the processing liquid supply unit via a manifold. The coating liquid is branched to a plurality of branch pipes connected to the nozzle; the reference flow meter is disposed in the manifold, and measures the flow rate of the coating liquid flowing in the manifold; the plurality of branch pipe flowmeters are respectively disposed in the branch pipes, and Measuring a flow rate of the coating liquid flowing in each of the branch pipes; and a plurality of flow control valves respectively disposed in the branch pipes and adjusting a flow rate of the coating liquid flowing in the respective branch pipes, the coating device is as follows The method of controlling the coating amount of the coating liquid: obtaining a relational expression indicating a relationship between the actual discharge flow rate and a flow rate measurement value of the reference flow meter, and a relationship between the flow rate measurement value of the reference flow meter and the flow rate measurement value of the branch pipe flow meter Relationship, using these relationships to control the flow control valve.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-45574

The coating device described in Patent Document 1 can be easily managed from each There is a room for improvement in the flow rate of the coating liquid discharged from the nozzle, but there is room for improvement in the following points. That is, the flow control valve has a difference between the flow rate set value and the actual flow rate value due to an error in the respective characteristics of the manufacturing, and the flow rate setting value and the actual flow rate value during the flow control are caused by the individual difference of the flow control valve. An error has occurred. The occurrence of such an error is a cause of uneven film thickness of the coating liquid, and thus causes a problem that unevenness in brightness of the display device occurs, so that display quality is deteriorated.

The present invention has been made to solve the above problems, and an object of the invention is to provide a coating liquid coating method and a coating apparatus which can accurately control the coating amount of a coating liquid.

The first invention is a coating liquid coating method which is a coating liquid coating method of a coating apparatus for applying a coating liquid to a substrate, the coating apparatus comprising: a coating liquid storage portion, which is retained a coating liquid; a plurality of nozzles for discharging the coating liquid; and a branching portion that diverts the coating liquid supplied from the coating liquid storage portion via the manifold to a plurality of branch pipes connected to the nozzle; , which is disposed in the above-mentioned manifold, and measures the flow rate of the coating liquid flowing in the manifold; a plurality of branch pipe flowmeters respectively disposed in the branch pipes, and measuring the flow rate of the coating liquid flowing in the branch pipes; a flow control valve respectively disposed on the branch pipe and adjusting a flow rate of the coating liquid flowing in the branch pipes; and a control unit that controls the flow control valves according to the flow rate value measured by each of the branch pipe flow meters The action of the coating liquid coating method includes: first a relational preparation step for obtaining a first relational expression indicating that the coating liquid stored in the coating liquid storage unit is supplied to only one of the plurality of branch pipes via the manifold The relationship between the flow rate value displayed by the reference flow meter disposed on the manifold and the flow rate value displayed by the branch flow meter disposed in the branch pipe to which the coating liquid is supplied; the second relational expression is created a step of obtaining a second relational expression indicating that the coating liquid stored in the coating liquid storage portion is supplied only to one of the plurality of branch pipes via the manifold a relationship between a flow rate setting value of a flow rate control valve provided in a branch pipe to which a coating liquid is supplied, and a flow rate value displayed by a branch pipe flow meter disposed in the branch pipe; and a branch pipe changing step, which is a plurality of The other branch pipe in the branch pipe sequentially executes the first relational expression preparation step and the second relational expression preparation step, and the coating step is based on the first relational expression and the second relational expression formed on each of the branch pipes And control Said flow control valve of the branch pipes, the coating liquid supplied to the substrate.

According to a second aspect of the invention, in the first relational expression forming step, the opening degree of the flow rate control valve is changed, and the following operation is repeatedly performed a plurality of times: storing in the coating liquid storage unit The coating liquid is supplied only to one of the plurality of branch pipes via the manifold.

According to a third aspect of the invention, in the second relational expression forming step, the opening degree of the flow rate control valve is changed, and the following operation is repeatedly performed a plurality of times: storing in the coating liquid storage unit The coating liquid is supplied only to one of the plurality of branch pipes via the manifold.

According to any one of the first to third aspects of the present invention, in the first aspect of the present invention, the correction step is performed before the step of the second relational expression preparation step, based on the weight of the coating liquid that has passed through the header and the above-mentioned The flow rate measured by the reference flow meter is corrected by the above reference flow meter.

According to a fifth aspect of the invention, a coating apparatus for applying a coating liquid to a substrate includes: a coating liquid storage portion that stores the coating liquid; and a plurality of nozzles that discharge the coating liquid; a branching portion that diverts a coating liquid supplied from the coating liquid storage portion via a header to a plurality of branch pipes connected to the nozzle; a reference flow meter disposed in the manifold and measuring a flow in the manifold a flow rate of the coating liquid; a plurality of branch pipe flowmeters respectively disposed on the branch pipes, and measuring a flow rate of the coating liquid flowing in the branch pipes; a plurality of flow control valves respectively disposed on the branch pipes, and adjusting a flow rate of the coating liquid flowing through each of the branch pipes; and a control unit that controls the operation of each of the flow rate control valves based on the flow rate value measured by each of the branch pipe flow meters; and the control unit according to the first relational expression and the second relationship In the above-described first relational expression, the first relational expression is that the coating liquid supplied to the manifold 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 stopped. The relationship between the flow rate value displayed by the reference flow meter measured in the state and the flow rate value displayed by the branch flow meter provided in the branch pipe to which the coating liquid is supplied, the second relational expression indicates that the second relational expression is provided The relationship between the flow rate setting value of the flow rate control valve of the branch pipe of the coating liquid and the flow rate value displayed by the branch pipe flow meter disposed in the branch pipe.

According to a fifth aspect of the present invention, there is provided a fifth aspect of the invention, comprising: a branch pipe for correction from the branch portion; an opening and closing valve disposed in the branch pipe for correction; and a container that receives only a coating liquid supplied to the manifold a coating liquid discharged from the calibration branch pipe and an electronic balance measuring the weight of the container and the coating liquid stored therein in a state where the supply of the coating liquid to the other branch pipe is stopped, and the coating liquid is stopped; A reference flow correction mechanism is included that performs calibration of the reference flow meter described above.

According to the first and fifth inventions, even when there is an individual difference in the branch pipe flow meter, the coating amount of the coating liquid can be extremely accurately controlled.

According to the second aspect of the invention, the first relational expression can be made more correct.

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

According to the fourth and sixth inventions, the flow rate of the coating liquid applied from each branch pipe can be accurately controlled by performing the calibration of the reference flow meter.

Hereinafter, embodiments of the present invention will be described based on the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a coating apparatus of the present invention, and Figure 2 is a front view thereof.

This coating apparatus is used to apply a coating liquid to the rectangular glass substrate 100. More specifically, the coating apparatus is configured to apply a volatile solvent (in the present embodiment, an aromatic organic solvent) to the glass substrate 100 for an active matrix driving type organic EL (Electro Luminescence) display device, and A coating liquid containing an EL material as a light-emitting material.

The coating device 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 portion 10 that holds the glass substrate 100 from the back surface thereof. The substrate holding portion 10 is supported by a base 13 that moves along a pair of rails 12 and a rotary table 14 that is disposed on the base 13. Therefore, the substrate holding portion 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 reciprocating direction of the coating head 20, that is, the main scanning direction (X direction in Fig. 1). Hereinafter, the Y direction is also referred to as a "sub-scanning direction". Moreover, the substrate holding portion 10 can be rotated about the axis in the vertical direction (the Z direction in FIG. 1).

The substrate holding portion 10 includes therein a heater that heats the glass substrate 100 from the lower side. On the surface of the glass substrate 100, a plurality of coating regions extending in the X direction are arranged in the Y direction at intervals of, for example, 100 to 150 μm. The coating region is formed by, for example, a separator disposed in the X direction.

Further, the coating apparatus includes a pair of left and right image pickup units 15 formed on the glass substrate 100 for taking an image and detecting an alignment mark (not shown), and photographing the coating trajectory of the coating head 20. A charge coupled device (CCD) camera is disposed in each of the pair of imaging units 15. Further, the coating apparatus includes a pair of left and right test coating platform portions 16 for test coating of a coating trajectory. In the coating apparatus, a configuration is adopted in which the feed control of the coating head 20 is adjusted by the coating trajectory applied by the test coating stage portion 16.

The coating head 20 that discharges the coating liquid toward the surface of the glass substrate 100 held on the substrate holding portion 10 is guided by the head moving mechanism 21 along the guiding portion 22 in the main scanning direction parallel to the surface of the glass substrate 100 ( The X direction in Fig. 1 is reciprocating. 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 shown for convenience of illustration, but the number of nozzles 23 is larger.

The coating head 20 is connected to the coating liquid supply unit 24 and the air supply source 25 via a supply tube group 26 in which an air supply pipe and a plurality of branch pipes described below are integrated. In the reciprocating direction (X direction) of the coating head 20, two liquid receiving portions 17, 18 for receiving the coating liquid from the nozzles 23 in the coating head 20 are disposed on both sides of the substrate holding portion 10. Further, in the reciprocating direction (X direction) of the coating head 20, a nozzle pitch adjusting mechanism 19 for adjusting the distance between the sub-scanning directions of the plurality of nozzles 23 is disposed on the side of one of the liquid receiving portions 18.

Figure 3 is a cross-sectional view of the vicinity of the slider 31 of the head moving mechanism 21.

In the head moving mechanism 21 shown in Fig. 1, the guide member 22 is slidably provided with a slider 31. A through hole 32 through which the guide member 22 is inserted is formed in the slider 31. As shown in FIG. 1, the slider 31 is supplied with air of a fixed pressure from the air supply source 25 via an air supply pipe included in the supply pipe group 26. Therefore, as shown in FIG. 3, air is ejected between the inner circumferential surface of the through hole 32 and the outer circumferential surface of the guide portion 22. In Fig. 3, the direction in which the air is ejected is indicated by an arrow with a symbol A1. Thereby, one side of the slider 31 and the guiding portion 22 is engaged in a non-contact state and is movably supported in the main scanning direction.

Referring to Fig. 1, a pair of pulleys 33 that are rotatable about an axis in the Z-axis direction are disposed in the vicinity of both end portions of the guide portion 22. A pair of synchronous conveyor belts 34 are wound around the pair of pulleys 33. One end of the slider 31 is fixed to the synchronous transfer belt 34. On the other hand, the coating head 20 is fixed to the other end of the slider 31. Therefore, the synchronous transfer belt 34 is rotated clockwise or counterclockwise by the driving of a motor (not shown), whereby the coating head 20 can be reciprocated in the (-X) direction or the (+X) direction. At this time, the slider 31 can be supported in a non-contact state with respect to the guide portion 22 by the action of the gas, so that the reciprocating movement of the coating head 20 can be made high-speed and smooth.

In the coating apparatus, the head moving mechanism 21 is a main scanning direction moving mechanism that moves the coating head 20 in the main scanning direction, and the substrate moving mechanism 11 is a sub-scanning direction moving mechanism that moves the substrate holding portion in the sub-scanning direction. . In the 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, thereby applying the coating liquid to the coating region on the surface of the glass substrate 100. cloth. Further, when the main scanning of the coating head 20 is performed, acceleration or deceleration is completed in the vicinity of the liquid receiving portions 17, 18. Further, above the glass substrate 100, the coating head 20 is fixed at, for example, about 3 to 5 m per second. Move by speed.

In the coating apparatus having the above configuration, when the application of the coating liquid is started, the glass substrate 100 is initially held by the substrate holding portion 10. Then, the alignment mark formed on the glass substrate 100 is detected by the imaging unit 15, and the substrate holding portion 10 is moved and rotated based on the detection result, and the glass substrate 100 is placed on the solid line as shown in FIG. position. In this state, the plurality of nozzles 23 from the coating head 20 start to discharge the coating liquid, 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 the surface of the plurality of nozzles 23 toward the surface of the glass substrate 100 at a fixed flow rate, and the coating head 20 is continuously moved at a constant speed in the main scanning direction, and the coating liquid is stripe-like. A plurality of linear regions applied to the coating region of the glass substrate 100.

In this manner, the coating head 20 is moved to a standby position in which the liquid receiving portion 18 is indicated by a two-dot chain line in FIGS. 1 and 2, whereby a striped pattern of the coating liquid is formed. When the coating head 20 is moved to the standby position, the substrate moving mechanism 11 is driven to move the glass substrate 100 together with the substrate holding portion 10 in the sub-scanning direction. At this time, the coating head 20 continuously discharges the coating liquid from the plurality of nozzles 23 to the liquid receiving portion 18.

Continue the operation as described above until the necessary coating action is completed. Then, when the glass substrate 100 is moved to the application end position, the application of the coating liquid from the plurality of nozzles 23 is stopped, and the coating operation of the coating liquid on the glass substrate 100 by the coating device is completed. The glass substrate 100 after completion of the application is transferred to another coating device or the like, and a coating liquid of two colors other than the coating liquid applied by the coating device is applied thereto. Then, after performing a predetermined coating step on the glass substrate 100, an organic EL is produced in combination with other parts. Display device.

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

This coating device includes a control unit 60 that controls the entire device. The control unit 60 is connected to the substrate moving mechanism 11, the rotary table 14, and the head moving mechanism 21. Further, the control unit 60 is connected to the flow rate control valve 40 of the coating liquid supply unit 24, the reference flow meter 42, the flow rate control valve 44, the branch flow meter 45, the opening and closing valve 46, the opening and closing valve 51, and the correction unit 52. Further, although not shown, the control unit 60 includes a memory composed of a RAM (random-access memory) or a ROM (read only memory) for performing various operations described below. A computing unit composed of a CPU (central processing unit) or the like. The control unit 60 may be a general personal computer or may be configured by a printed circuit board or the like. The configuration of the reference flow meter 42, the flow rate control valve 44, the branch pipe flow meter 45, the opening and closing valve 46, the opening and closing valve 51, the correction unit 52, and the like will be described below.

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

The coating liquid supply unit 24 in the coating apparatus of the present invention includes a flow rate control valve 40, a coating liquid storage unit 41, a reference flow meter 42, a manifold 43 as a branching portion, a plurality of flow rate control valves 44a and 44b, 44c, ... 44n, multiple branches The flowmeters 45a, 45b, 45c, ..., 45n, the plurality of on-off valves 46a, 46b, 46c, ..., 46n, the on-off valve 51, and the following correction section 52. Each of the on-off valves 46a, 46b, 46c, ... 46n is connected to a plurality of nozzles 23a, 23b, 23c, ... 23n of the coating head 20, respectively.

Furthermore, in the present specification, a plurality of flow control valves 44a, 44b, 44c, ... 44n are collectively referred to as flow control valves 44 as needed, and a plurality of branch flow meters 45a, 45b, 45c, ... 45n are collectively expressed as branch pipes. The flow meter 45 collectively expresses a plurality of on-off valves 46a, 46b, 46c, ..., 46n as an opening and closing valve 46, and a plurality of nozzles 23a, 23b, 23c, ..., 23n are collectively referred to as nozzles 23.

In addition, in the present specification, the line before the branch of the manifold 43 from the coating liquid storage unit 41 via the flow rate control valve 40 and the reference flow meter 42 is referred to as a manifold. Further, in the present specification, the self-manifold pipe 43 is passed through the respective flow rate control valves 44a, 44b, 44c, ... 44n, the branch pipe flow meters 45a, 45b, 45c, ... 45n, and the respective opening and closing valves 46a, 46b, 46c, ... 46n. The pipe that reaches the branch of each of the nozzles 23a, 23b, 23c, ... 23n is called a branch pipe. In the coating apparatus, a plurality of branch pipes corresponding to a to n are present. Further, in the present specification, the line that reaches the correction unit 52 from the manifold 43 via the opening and closing valve 51 is referred to as a correction branch pipe.

The coating liquid storage unit 41 has a configuration in which a flexible bag-shaped container in which a coating liquid is stored is housed in an airtight chamber, and a coating liquid is supplied by supplying pressurized air to the airtight chamber. It is configured to be pressure-fed to the flow control valve 40, the reference flow meter 42, the manifold 43, and the like. Moreover, the reference flow meter 42 has a self-coating measurement The flow rate of the coating liquid flowing into the manifold 43 discharged from the liquid storage unit 41. The reference flow meter 42 uses a thermal type flow meter that measures the flow rate of the coating liquid by using a heater and a temperature sensor provided in a flow path of the coating liquid. The measured value of the flow rate measured by the reference flow meter 42 is sent to the control unit 60 shown in Fig. 4 .

Each flow control valve 44 receives an instruction from the control unit 60 shown in Fig. 4 to adjust the flow rate of the coating liquid flowing through each branch pipe. Further, each branch pipe flow meter 45 measures the flow rate of the coating liquid flowing through each branch pipe. As the branch pipe flow meter 45, a thermal type flow meter is used similarly to the reference flow meter 42, and the flow rate of the coating liquid is measured by a heater and a temperature sensor. The measured value of the flow rate measured by the branch pipe flow meter 45 is sent to the control unit 60 shown in Fig. 4 . The flow control valve 44 and the branch flow meter 45 constitute a mass flow controller. Further, each of the opening and closing valves 46 receives an instruction from the control unit 60 shown in Fig. 4 to open or close the flow paths of the respective branch pipes. Similarly, the opening and closing valve 51 receives an instruction from the control unit 60 shown in FIG. 4 to open or close the flow path from the manifold 43 to the correction branch of the correction unit 52.

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

The correction unit 52 includes a container 53 in which a coating liquid is stored in advance. The container 53 is placed on an electronic balance 54 disposed on the support portion 59 of the coating device. The electronic balance 54 and the container 53 are housed in the chamber 55. A lid body 56 is disposed on the upper portion of the container 53. The lid body 56 is coupled to the chamber 55 via the coupling member 58, and is disposed at a position spaced apart from the upper end of the container 53 by a slight distance. from The front end portion of the calibration branch pipe 51 to the correction portion 52 shown in FIG. 5 is connected to the metal thin tube 57. As shown in FIG. 6, the metal thin tube 57 penetrates the chamber 55 and the lid 56 and is immersed in the container 53. Further, the front end portion of the thin tube 57 is immersed in the coating liquid stored in the container 53. In the figure, the symbol L indicates the liquid surface of the coating liquid stored in the container 53 before the correction operation described below, and the symbol H indicates the application when the coating liquid is stored in the container 53 to the limit. Liquid level. The electronic balance 54 measures the weight of the container 53 and the coating liquid stored therein.

Next, the coating operation of the coating liquid which is carried out by the coating apparatus having the above configuration will be described. Fig. 7 is a flow chart showing the steps of the coating liquid coating method of the present invention.

Initially, the calibration of the reference flow meter 42 is performed (step S1).

FIG. 8 is a flow chart showing the calibration procedure of the reference flow meter 42. The calibration of the reference flow meter 42 is performed in the steps shown in FIG.

That is, initially, the opening and closing valve 51 shown in Fig. 4 is opened. At this time, the coating liquid storage unit 41 is supplied with pressurized air of a predetermined pressure, and the coating liquid is transported to the manifold 43 via the flow rate control valve 40 and the reference flow meter 42. Further, the opening and closing valve 46 in each branch pipe is stopped in advance. By this, the coating liquid is pressure-fed from the coating liquid storage unit 41 to the correction unit 52 via the flow rate control valve 40, the reference flow meter 42, the manifold 43, and the opening and closing valve 51. Then, in the correction unit 52 shown in FIG. 6, the pumped liquid is discharged from the metal thin tube 57 into the coating liquid in the container 53 (step S11).

Then, the flow rate value displayed by the reference flow meter 42 when the coating liquid is discharged into the container 53 is obtained (step S12). This flow rate value is sent to the control unit 60 shown in FIG. Moreover, the weight of the coating liquid discharged into the container 53 is measured by the electronic balance 54 (step S13). The weight of the discharged coating liquid is based on the total value of the weight of the container 53 measured by the electronic balance 54 and the coating liquid previously stored therein before the discharge of the coating liquid, and the electronic balance after the discharge of the coating liquid. The difference between the total value of the weight of the container 53 measured in 54 and the coating liquid stored therein was measured. The measured weight of the discharged coating liquid is sent from the correction unit 52 to the control unit 60 shown in Fig. 4 .

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

In this case, after the standby time t0 of about 5 seconds from the start of discharge until the discharge amount is stabilized, for example, the amount of change dw of the weight per unit time dt per second is measured, thereby measuring the flow per unit time. The weight of the coating liquid (dw/dt). This was repeated, for example, 10 times, and 10 data obtained during 10 seconds were averaged, thereby obtaining data on the weight of the coating liquid flowing per unit time. Then, by adjusting the flow rate control valve 40, the flow rate value is changed, and the above-described operation is performed only for the necessary number of times, for example, three to five times (step S14). Here, w0 in Fig. 9 indicates the total value, that is, the initial weight, of the weight of the container 53 and the coating liquid initially stored therein.

In addition, instead of setting the unit time dt to about 1 second as described above, it is set to about 5 seconds, and 10 pieces of data are acquired in 50 seconds. In this case, a more accurate weight can be measured by adding the coping force of the electronic balance 54. However, the weight measurement takes a long time, and the amount of the coating liquid consumed increases. Further, the flow rate of the coating liquid can be changed to cause the above-described operation to be performed more than three times to five times. In this case, the measurement accuracy is also improved, but the measurement time and the consumption amount of the coating liquid increase.

Next, correction is performed (step S15). In other words, the control unit 60 shown in FIG. 4 calculates the coating liquid passing through the reference flow meter 42 based on the weight of the coating liquid flowing per unit time measured by the electronic balance 54 and the specific gravity of the coating liquid. Actual traffic. The actual flow is then compared to the flow value displayed by the reference flow meter 42. Thereafter, the reference flow meter 42 is adjusted such that the flow rate value displayed by the reference flow meter 42 matches the actual flow rate value. Thereby, the flow rate value displayed by the reference flow meter 42 can be made to coincide with the actual flow rate value of the coating liquid.

Referring again to FIG. 7, secondly, after selecting one of the plurality of branch pipes (step S2), the first relational expression creating step of the first relational expression is obtained (step S3), and the second relational expression is obtained. In the relational preparation step (step S4), the first relational expression indicates a flow rate value displayed by the reference flow meter 42 when the coating liquid is supplied only to one of the branch pipes, and a branch flowmeter that is supplied to the branch pipe to which the coating liquid is supplied The relationship between the flow rate values indicated by 45, and the second relational expression indicates the flow rate setting value and the arrangement of the flow rate control valve 44 to which the branch liquid to which the coating liquid is supplied when the coating liquid is supplied to only one of the branch pipes. The relationship between the flow values displayed by the branch flow meter 45 of the branch pipe.

Fig. 10 is a flow chart showing the steps of the first relational expression creation. First relation The making step is performed in the step shown in FIG.

That is, initially, the flow rate of the coating liquid is set (step S31). In this case, the flow rate control valve 44 of the branch pipe is adjusted by the control of the control unit 60 so that the flow rate value displayed by the branch pipe flow meter 45 of the selected branch pipe becomes a predetermined target value. Then, the on-off valve 46 of the selected branch pipe is opened in accordance with an instruction from the control unit 60. At this time, the opening and closing valve 46 of the branch pipe other than the selected branch pipe is closed.

In this state, the coating liquid storage unit 41 conveys the coating liquid 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 and closing valve 46 . And the coating liquid is discharged from the nozzle 23 (step S32). Then, the flow rate value measured by the reference flow meter 42 at this time is obtained (step S33), and the flow rate value measured by the branch flow meter 45 of the selected branch pipe is obtained (step S34). The flow rate values obtained are transmitted to the control unit 60.

Then, the flow rate of the coating liquid is set again (step S31) until the necessary processing is completed (step S35). In other words, the flow rate value displayed by the branch flow meter 45 of the selected branch pipe is controlled by the control unit 60 to be a value corresponding to the flow rate value of the coating liquid when the coating liquid is actually applied to the glass substrate 100, The flow rate control valve 44 of the branch pipe is adjusted so as to be a flow rate value 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 are repeated. Step S34).

That is, the relationship between the flow rate value displayed by the reference flowmeter 42 and the flow rate value displayed by the branch pipe flow meter 45 is similar to the flow rate value of the coating liquid when the coating liquid is actually applied to the glass substrate 100. Point (for example, 3~5 points) is obtained. For example, when the target value of the flow rate is set to 100, the same operation is performed for the flow rate values near the target value such as 80%, 90%, 110%, and 120%. Therefore, the flow rate setting step (step S31), the 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 (step S34) of the branch flow meter are repeatedly executed. Multiple times.

Further, in this case, the relationship between the flow rate value displayed by the reference flow meter 42 and the flow rate value displayed by the branch pipe flow meter 45 can be obtained at a point more than 3 to 5 points. In this case, not only the range of 80% to 120% as described above but also the range of necessary flow rates such as 50% to 200% can be appropriately selected.

When the necessary flow rate value has been obtained (step S35), the relationship between the flow rate value indicated by the reference flow meter 42 and the flow rate value displayed by the branch flow meter 45 to which the branch liquid of the coating liquid is supplied is created. The first relational expression (step S36).

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

In the graph shown in FIG. 11, three points plot the relationship between the flow rate value F displayed by the reference flow meter 42 and the flow rate value f displayed by the branch flow meter 45, and An approximate curve (straight line in the present embodiment) passing through the three points is used as a flow rate value indicated by the reference flow meter 42 and a flow rate value displayed by the branch flow meter 45 to which the branch liquid to which the coating liquid is supplied. The first relational expression of the relationship is obtained. This first relational expression is derived using, for example, the least squares method. When A and B are set as coefficients, the first relational expression is represented by the following formula (1).

F=A*f+B.........(1)

Furthermore, the first relational expression is not limited to the one-time expression described above. The relationship between the flow rate value displayed by the reference flow meter 42 and the flow rate value displayed 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 straight line approximations can be performed by increasing the measurement points.

Fig. 12 is a flow chart showing the steps of the second relational expression creation. The second relational preparation step is performed in the step shown in Fig. 12.

That is, initially, the flow rate of the coating liquid is set (step S41). In this case, the flow rate control valve 44 of the branch pipe is adjusted by the control of the control unit 60 so that the flow rate value displayed by the branch pipe flow meter 45 of the selected branch pipe becomes a predetermined target value. Then, the on-off valve 46 of the selected branch pipe is opened in accordance with an instruction from the control unit 60. At this time, the opening and closing 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 rate control valve 44 of the selected branch pipe, the branch flow meter 45, and the opening and closing valve 46. And the coating liquid is discharged from the nozzle 23 (step S42). Then, the flow rate setting of the flow control valve 44 at this time is obtained. The value is obtained (step S43), and the flow rate value displayed by the branch flow meter 45 at this time is obtained (step S44). The flow rate setting value of the flow rate control valve 44 obtained by the above and the flow rate value displayed by the branch pipe flow meter 45 are sent to the control unit 60.

Then, the flow rate of the coating liquid is set again (step S41) until the necessary processing is completed (step S45). In other words, the flow rate value displayed by the branch pipe flow meter 45 of the selected branch pipe is controlled by the control unit 60 so as to be a flow rate value different from the flow rate value in the previous coating liquid discharge step (step S42). The flow control valve 44 of the branch pipe is adjusted. Then, the above-described coating liquid discharge step (step S42), the flow rate set value acquisition step (step S43), and the actual flow rate value acquisition step (step S44) are repeatedly executed.

That is, the relationship between the flow rate setting value of the flow rate control valve 44 and the flow rate value displayed by the branch pipe flow meter 45 at this time is similar to the flow rate value of the coating liquid when the coating liquid is actually applied to the glass substrate 100. The number of complex points (for example, 3 to 5 points) is obtained. For example, when the target value of the flow rate is set to 100, the same operation is performed for the flow rate values near the target value such as 80%, 90%, 110%, and 120%. Therefore, the flow rate setting step (step S41), the coating liquid discharge step (step S42), the flow rate set value obtaining step (step S43), and the flow rate value obtaining step (step S44) of the branch pipe flow meter 45 are repeatedly executed a plurality of times. .

Further, in this case, the relationship between the flow rate setting value of the flow rate control valve 44 and the flow rate value displayed by the branch pipe flow meter 45 at this time can be obtained at a point more than 3 to 5 points. In this case, it can be based not only on the range of 80% to 120% as described above, but also on the necessary flow range such as 50% to 200%. And choose the right one.

When the flow rate setting value of the flow control valve 44 and the flow rate value displayed by the branch flow meter 45 are obtained (step S45), the flow rate setting value indicating the flow rate control valve 44 of the branch pipe to which the coating liquid is supplied is created, A second relational expression relating to the flow rate value displayed by the branch flowmeter 45 disposed in the branch pipe (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 displayed by the branch pipe flow meter 45.

In the graph shown in FIG. 13, the relationship between the flow rate setting value x of the flow control valve 44 and the flow rate value f displayed by the branch flow meter 45 is plotted at three points, and the approximate curve of the three points is passed (this embodiment) The middle line is the relationship between the flow rate setting value x of the flow rate control valve 44 indicating the branch pipe to which the coating liquid is supplied, and the flow rate value f displayed by the branch pipe flow meter 45 to which the branch liquid of the coating liquid is supplied. The second relational expression is obtained. This second relational expression is also derived using, for example, the least squares method. When C and D are set as coefficients, the second relational expression is represented by the following formula (2).

x=Cf+D.........(2)

The second relational expression is also not limited to the one-time expression described above. The relationship between the flow rate set value of the branch pipe to which the coating liquid is supplied and the flow rate value displayed by the branch pipe flow meter to which the coating liquid is supplied may be approximated by a curve. Further, a plurality of straight line approximations can be performed by increasing the measurement points.

Furthermore, in the above embodiment, for convenience of explanation, it is made in the second relational expression. In the step (step S2), the flow rate setting step (step S41) and the same flow rate setting step (step S31) and the coating liquid discharge step (step S32) in the first relational expression preparation step (step S3) are performed and coated. The cloth discharge step (step S42). However, these steps can also be completed simultaneously. In other words, after the flow rate setting step (step S31) and the coating liquid discharge step (step S32) in the first relational expression preparation step (step S3) are performed, the flow rate value acquisition step of the reference flow meter 42 can be simultaneously performed (step S33), a flow rate obtaining step of the branch pipe flow meter 45 (step S34), and a flow rate setting value obtaining step of the flow rate control valve 44 (step S43).

Referring again to Fig. 7, when the first relational expression and the second relational expression are obtained by the above steps, the different branch pipes are selected next (step S2), and the first relational expression preparation step (step) is executed for the different branch pipes. S3) and a branch change step (step S5) of the second relational expression preparation step (step S4).

Then, when the first relational expression and the second relational expression are obtained for all the branch pipes by the above steps (step S5), the adjustment step of the flow rate control valve 44 is executed (step S6). In this case, the following formula (3) is obtained by substituting f of the above formula (1) into the formula (2).

x=(C/A)*(F-B)+D.........(3)

After the adjustment of the flow rate control valve 44 is performed according to the equation (3), the application of the coating liquid to the glass substrate 100 is performed (step S7). At this time, the calibration of the reference flowmeter 42 has been completed in the previous reference flowmeter calibration step (step S1), and the flow control valve can be corrected in the second relational preparation step (step S4). The relationship between the flow rate setting value of 44 and the flow rate value displayed by the branch pipe flow meter 45 allows the coating liquid to be discharged at a correct flow rate to perform the coating operation.

Further, the calibration step (step S1) of the reference flow meter 42 and the first and second relational expression preparation steps (steps S2 to S5) corresponding to the respective branch pipes need not be performed every time the coating liquid is applied. Execute. These steps may be performed only when, for example, changing the liquid type of the coating liquid or when it is necessary to perform the coating operation only during the fixed period.

Further, in the above-described embodiment, when the first and second relational expression preparation steps (steps S2 to S5) corresponding to the respective branch pipes are executed, the coating liquid is supplied to the respective branch pipes via the flow rate control valve 40 and the reference flow meter 42. However, in the coating step of the coating liquid, a dedicated bypass line for supplying the coating liquid to each branch pipe may be disposed.

10‧‧‧Substrate retention department

11‧‧‧Substrate moving mechanism

12‧‧‧ Track

13‧‧‧Abutment

14‧‧‧Rotating table

15‧‧‧Photography Department

16‧‧‧Test Coating Platform Division

17‧‧‧Liquid Department

18‧‧‧Liquid Department

19‧‧‧Nozzle spacing adjustment mechanism

20‧‧‧Coating head

21‧‧‧ head moving mechanism

22‧‧‧ Guidance Department

23, 23a~23n‧‧‧ nozzle

24‧‧‧ Coating Liquid Supply Department

25‧‧‧Air supply source

26‧‧‧Supply management group

31‧‧‧Sliding parts

32‧‧‧through holes

33‧‧‧ pulley

34‧‧‧Synchronous conveyor belt

40‧‧‧Flow control valve

41‧‧‧ Coating Liquid Storage Department

42‧‧‧reference flowmeter

43‧‧‧Management

44, 44a~44n‧‧‧ flow control valve

45, 45a~45n‧‧‧ branch pipe flowmeter

46, 46a~46n‧‧‧Opening and closing valve

51‧‧‧Opening and closing valve

52‧‧‧Correction Department

53‧‧‧ Container

54‧‧‧electronic balance

55‧‧‧ chamber

56‧‧‧ Cover

57‧‧‧Metal tubules

58‧‧‧Connected components

59‧‧‧Support Department

60‧‧‧Control Department

100‧‧‧ glass substrate

A1‧‧‧ symbol

Dt‧‧‧ unit time

Dw‧‧‧changes

H‧‧‧The liquid level of the coating liquid when the coating liquid is stored in the container 53 to the limit

L‧‧‧The liquid level of the coating liquid stored in the container 53 before the correcting operation

Figure 1 is a plan view of a coating apparatus of the present invention.

Figure 2 is a front elevational view of the coating apparatus of the present invention.

Figure 3 is a cross-sectional view of the vicinity of the slider 31 of the head moving mechanism 21.

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

FIG. 5 is a schematic view showing a configuration of the coating liquid supply unit 24 and a connection relationship between the coating liquid supply unit 24 and a plurality of nozzles 23 of the coating head 20.

FIG. 6 is a schematic diagram of the correction unit 52.

Fig. 7 is a flow chart showing the steps of the coating liquid coating method of the present invention.

FIG. 8 is a flow chart showing the calibration procedure of the reference flow meter 42.

Fig. 9 is an explanatory view showing the weight measuring operation of the coating liquid.

Fig. 10 is a flow chart showing the steps of the first relational expression creation.

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

Fig. 12 is a flow chart showing the steps of the second relational expression creation.

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 displayed by the branch pipe flow meter 45.

Claims (6)

A coating liquid coating method, which is a coating liquid coating method of a coating apparatus for applying a coating liquid to a substrate, the coating apparatus comprising: a coating liquid storage portion that stores a coating liquid; a plurality of nozzles for discharging the coating liquid; and a branching portion for diverting the coating liquid supplied from the coating liquid storage portion via the manifold to a plurality of branch pipes connected to the nozzle; and a reference flow meter In the above-mentioned main pipe, and measuring the flow rate of the coating liquid flowing in the main pipe; a plurality of branch pipe flowmeters respectively disposed in the branch pipe, and measuring the flow rate of the coating liquid flowing in each branch pipe; a plurality of flow control valves And respectively disposed in the branch pipe, and adjusting a flow rate of the coating liquid flowing in each branch pipe; and a control unit that controls the operation of each of the flow rate control valves according to the flow rate value measured by each of the branch pipe flow meters; The coating liquid coating method includes a first relational expression preparation step for obtaining a first relational expression indicating a coating liquid to be stored in the coating liquid storage portion. Only supplied to the upper via the above-mentioned main pipe The relationship between the flow rate value indicated by the reference flow meter disposed in the manifold and the flow rate value displayed by the branch flow meter disposed in the branch pipe to which the coating liquid is supplied, in the case where one of the plurality of branch pipes is one; a relational preparation step for obtaining a second relational expression indicating that the coating liquid stored in the coating liquid storage unit is supplied only to the plurality of branch pipes via the manifold 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 displayed by the branch pipe flow meter disposed in the branch pipe; a branch pipe changing step of sequentially performing the first relational expression forming step and the second relational formula forming step on the other of the plurality of branch pipes; and a coating step according to the above-mentioned The relational expression and the second relational expression described above control the flow rate control valves of the respective branch pipes, and supply the coating liquid to the substrate. The coating liquid coating method according to claim 1, wherein in the first relational expression preparation step, the opening degree of the flow rate control valve is changed, and the following operation is repeatedly performed a plurality of times: the storage is performed on the coating The coating liquid in the cloth liquid storage portion is supplied only to one of the plurality of branch pipes via the manifold. The coating liquid coating method according to claim 1, wherein in the second relational expression preparation step, the opening degree of the flow rate control valve is changed, and the following operation is repeatedly performed a plurality of times: the storage is performed on the coating The coating liquid in the cloth liquid storage portion is supplied only to one of the plurality of branch pipes via the manifold. The coating liquid coating method according to any one of claims 1 to 3, further comprising a correction step of the coating liquid which has passed through the header according to the second relational expression preparation step The weight and the flow rate measured by the above-described reference flow meter at this time are used to perform the correction of the above-described reference flow meter. A coating device for applying a coating liquid to a substrate, comprising: a coating liquid storage portion that stores the coating liquid; a plurality of nozzles for discharging the coating liquid; and a branching portion for diverting the coating liquid supplied from the coating liquid storage portion via the manifold to a plurality of branch pipes connected to the nozzle; and a reference flow meter In the above-mentioned main pipe, and measuring the flow rate of the coating liquid flowing in the main pipe; a plurality of branch pipe flowmeters respectively disposed in the branch pipe, and measuring the flow rate of the coating liquid flowing in each branch pipe; a plurality of flow control valves Each of the branch pipes is disposed on the branch pipe and adjusts a flow rate of the coating liquid flowing in the branch pipes; and a control unit that controls the operation of each of the flow rate control valves according to the flow rate value measured by each of the branch pipe flow meters; The control unit controls the flow rate control valve according to the first relational expression and the second relational expression, wherein the first relational expression indicates that the coating liquid supplied to the manifold is supplied only to a single branch pipe selected from the plurality of branch pipes. And the flow rate value displayed by the reference flow meter measured in a state where the supply of the coating liquid is stopped to the other branch pipe and the flow rate of the branch pipe provided in the branch pipe to which the coating liquid is supplied are displayed. The relationship between the flow rate values and the second relational expression indicates the relationship between the flow rate setting value of the flow rate control valve provided in the branch pipe to which the coating liquid is supplied, and the flow rate value displayed by the branch pipe flow meter disposed in the branch pipe. . The coating device of claim 5, comprising: a branch pipe for calibration, which is branched from the branch portion; and an opening and closing valve, which is disposed in the branch pipe for correction; The container receives the coating liquid discharged from the calibration branch pipe in a state where the coating liquid supplied to the header pipe is supplied only to the calibration branch pipe and the application of the coating liquid to the other branch pipe is stopped; and an electronic balance, It measures the weight of the container and the coating liquid stored therein; and includes a reference flow rate correcting mechanism that performs calibration of the reference flow meter.