JP2017154086A - Coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize a film thickness defect part in a coating start end part in the case of using press feeding of a coating liquid in addition to supplying the same with a pump to a coater when coating is started.SOLUTION: A coating apparatus 5 comprises a pump 30 that supplies a coating liquid to a coater 10, a press feeding means 40 that supplies the coating liquid to the coater 10 by giving pressure to the coating liquid, a controller 50, and a pressure sensor 30 that measures the pressure of the coating liquid. The controller 50 can execute the control of coating operation including a first operation for supplying the coating liquid to the coater 10 by the combinational use of the pump 30 with the press feeding means 40 to start coating and a second operation for supplying the coating liquid to the coater 10 by the use of the pump 30 after coating is started. The controller 50 further uses pressure values a pressure sensor 60 acquires in the second operation to correct the pressure the press feeding means 40 supplies to the coating liquid and uses the corrected pressure to execute the first operation in a later coating operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coating apparatus and a coating method for forming a coating film on a member to be coated.

  The color liquid crystal display includes a color filter, a TFT array substrate, and the like. Manufacturing of these color filters and TFT array substrates includes a step of applying a coating liquid (liquid material) to a substrate as a member to be coated and drying it to form a coating film.

  As described above, a slit coater is used as a coating apparatus for forming a coating film on a substrate, and the slit coater includes an applicator (also referred to as a nozzle) having an elongated discharge port. This coating method using a slit coater is performed by causing the discharge port to approach the substrate and discharging the coating liquid from the discharge port while relatively moving the substrate and the applicator. Thereby, a coating film can be formed on the substrate.

  Here, in order to produce a high-quality product by forming a coating film on the substrate, it is desirable to make the film thickness uniform in the region from the start of application to the substrate to the end of application. Therefore, the relative movement speed between the substrate and the applicator may be kept constant, and the flow rate of the coating liquid discharged from the discharge port (the amount of liquid per unit time) may be kept constant. A piston pump (also referred to as a syringe pump) is used that can make the flow rate of supplying the water constant with high accuracy.

  However, even if the coating liquid is supplied to the applicator at a constant flow rate using a piston pump, a slight area after the start of application (range from the application start position to several millimeters: hereinafter, this area is referred to as the application start end. The film thickness of the intermediate region is greatly different from the film thickness of the intermediate region (exceeding the allowable value), and a so-called defective film thickness is obtained at the coating start end. This is because while the intermediate region of the substrate is being applied, the coating liquid bead is constantly present in a constant size between the discharge port and the substrate, so that stable application is maintained. This is because, at the application start end, application is started while forming a bead with the application liquid discharged from the discharge port, so that the application liquid becomes insufficient and the film thickness becomes poor.

  Therefore, in Patent Document 1, in order to prevent a defective film thickness at the coating start end, in addition to the “quantitative discharge” performed by supplying the coating liquid from the piston pump to the applicator at a constant flow rate, The “excess discharge” is performed by supplying an extra amount of the coating liquid necessary for forming the liquid to the applicator. In the case of the slit coater described in Patent Document 1, in order to realize the excessive discharge, a mechanism for pumping the coating liquid to the applicator is provided, and this mechanism is configured to apply the coating liquid connected to the applicator through a pipe. A tank to be stored and a pressurizing means for pressurizing the coating liquid of the tank are provided. As a result, it is possible to pressurize the coating liquid in the tank to pump the coating liquid to the applicator and perform the excessive discharge.

JP2015-192987A

  According to the slit coater described in Patent Document 1, it becomes possible to instantaneously supply the coating liquid in an amount necessary for forming a bead of the coating liquid by pressure feeding, and a desired coating liquid amount to the coating start end of the substrate. Application can be started. As a result, the defective film thickness portion at the coating start end is reduced, and the product area of high quality is widened to increase productivity.

  In the substrate, in order to reduce the region where the defective film thickness is as small as possible and widen the effective range, the length of the defective film thickness portion at the coating start end may be minimized. However, for example, if the viscosity of the coating solution changes due to temperature changes or clogged with fine foreign matter near the discharge port, the discharge amount is unstable even if excessive discharge is performed by pumping to start coating. Therefore, there is a possibility that the length (range) of the portion where the film thickness is defective varies. Specifically, as shown in FIG. 7A, when the viscosity of the coating solution is relatively high, the length L1 of the film thickness defect portion 92 at the coating start end portion 91 of the substrate 90 is shortened. When the viscosity of the liquid is relatively low, the amount of excess discharge increases at the same pumping pressure, and the length L2 of the film thickness defect portion 92 becomes longer as shown in FIG. 7B (L2> L1). As one of the causes that the viscosity of the coating solution changes depending on the temperature, in continuous production, the device temperature is low at the initial stage of operation, but if the operation is continued, the device temperature slightly increases. May affect the temperature of the coating solution.

  In order to perform continuous production using the slit coater (coating device) as described above, even if the viscosity of the coating liquid fluctuates with time, for example, even if a minute foreign matter adheres to the vicinity of the discharge port, It is necessary to minimize the film thickness defect portion at the coating start end by stably supplying an appropriate amount of the coating liquid by pressure to the container and discharging it excessively from the discharge port.

  Therefore, the present invention stably minimizes the film thickness defective portion at the coating start end when supplying the coating liquid to the applicator by a pump at the start of coating and also using pressure feeding. With the goal.

  The coating apparatus of the present invention includes a coating device having a discharge port for discharging a coating liquid to a coating member, and the coating device and the coating member in a direction parallel to a coating surface of the coating member. A moving means for moving; a pump capable of supplying a predetermined amount of coating liquid to the applicator; a pressure feeding means capable of supplying the coating liquid to the applicator by applying pressure to the coating liquid; A control device for controlling the pump and the pressure feeding means while performing the relative movement by the moving means to apply the coating liquid to the member, and a pressure for measuring the pressure of the coating liquid between the pump and the discharge port A first operation of supplying a coating liquid to the applicator by using the pump and the pressure feeding unit together for starting coating, and coating by the pressure feeding unit after starting coating. Stop supplying liquid A second operation of supplying a coating liquid to the applicator using the pump in a state where the pressure sensor is in a state where the pressure sensor is further operated in the second operation. Using the acquired pressure value, the pressure applied by the pumping means to the coating liquid is corrected, and the first operation in the subsequent coating operation is executed using the corrected pressure.

  According to this coating apparatus, when the coating operation is repeatedly performed, for example, even if the viscosity of the coating liquid changes or clogging occurs in the coating device, it is difficult to affect the subsequent coating operation. In the first operation at the start of application, an appropriate amount of application liquid can be discharged from the applicator to the application target member, and the defective film thickness portion can be stably minimized at the application start end.

In addition, the control device further includes a storage unit capable of storing a pumping pressure value generated for applying pressure to the coating liquid by the pumping unit, and a pressure value acquired by the pressure sensor. It is preferable that the first operation in the subsequent application operation can be performed using the pumping pressure value Pa (n) satisfying the expression (1).
Pa (n) = Pa / Pb × Pb (n−1) (1)
However,
Pa (n): a pumping pressure value generated in order to apply pressure to the coating liquid in the first operation of the subsequent application operation Pb (n-1): acquired by the pressure sensor in the executed second operation Pressure value Pa: a reference value stored in the storage means, and a pressure-feeding pressure value for applying pressure to the coating liquid by the pressure-feeding means Pb: a reference value stored in the storage means, Pressure value acquired by the pressure sensor in the second operation

  According to this configuration, if the pressure value Pb (n−1) acquired by the pressure sensor in the second operation in the performed coating operation is large, the coating liquid is used in the first operation in the subsequent coating operation. The pumping pressure value Pa (n) generated in order to apply pressure can also be increased (corrected), for example, when the viscosity of the coating liquid increases or clogging occurs in the applicator. Even in the first operation at the start of application, an appropriate amount of the application liquid can be discharged from the applicator to the member to be applied. On the contrary, if the pressure value Pb (n-1) is small, the pressure pressure value Pa (n) is also small (can be corrected), for example, the viscosity of the coating liquid is low. Even in this case, in the first operation at the start of application, an appropriate amount of application liquid can be discharged from the applicator to the member to be applied.

Moreover, it is preferable that the Pb (n-1) in the formula (1) is a pressure value acquired by the pressure sensor in the second operation in the most recent application operation that has been performed.
According to this coating apparatus, it is possible to correct the pressure (pressure feed pressure value) that the pressure feeding means applies to the coating liquid based on the information at the previous (immediately preceding) coating operation. Then, the first operation can be performed using the corrected pressure (pressure feed pressure value) in the next application operation.

  In the coating method of the present invention, an applicator having a discharge port for discharging a coating liquid to a member to be coated, and the applicator and the member to be coated are relative to each other in a direction parallel to the surface to be coated of the member to be coated. A moving means for moving; a pump capable of supplying a predetermined amount of coating liquid to the applicator; a pressure feeding means capable of supplying the coating liquid to the applicator by applying pressure to the coating liquid; and the pump. And a pressure sensor that measures the pressure of the coating liquid up to the discharge port. The coating method is performed using the pump and the pressure feeding unit while performing the relative movement by the movement unit. A coating operation is performed to apply a coating liquid to the coated member, and the coating operation includes a first operation of supplying the coating liquid to the coating device in combination with the pump and the pumping means for starting coating. The pressure after the start of application A second operation of supplying the application liquid to the applicator using the pump in a state where supply of the application liquid by the means is stopped, and the pressure value acquired by the pressure sensor in the second operation is included. The pressure applied by the pumping unit to the coating liquid is corrected, and the first operation in the subsequent coating operation is performed using the corrected pressure.

  According to this coating method, when the coating operation is repeatedly performed, for example, even if the viscosity of the coating liquid changes or clogging occurs in the coating device, the effect is less likely to be exerted on the subsequent coating operation. In the first operation at the start of application, an appropriate amount of application liquid can be discharged from the applicator to the application target member, and the defective film thickness portion can be stably minimized at the application start end.

Further, in the coating method, the coating apparatus includes a storage unit capable of storing a pressure-feeding pressure value generated for applying pressure to the coating solution by the pressure-feeding unit, and a pressure value acquired by the pressure sensor. Furthermore, it is preferable that the first operation in the subsequent application operation can be executed using a pumping pressure value Pa (n) satisfying the following expression (1).
Pa (n) = Pa / Pb × Pb (n−1) (1)
However,
Pa (n): a pumping pressure value generated in order to apply pressure to the coating liquid in the first operation of the subsequent application operation Pb (n-1): acquired by the pressure sensor in the executed second operation Pressure value Pa: a reference value stored in the storage means, and a pressure-feeding pressure value for applying pressure to the coating liquid by the pressure-feeding means Pb: a reference value stored in the storage means, Pressure value acquired by the pressure sensor in the second operation

  According to this method, if the pressure value Pb (n−1) acquired by the pressure sensor in the second operation in the performed application operation is large, the coating liquid is applied in the first operation in the subsequent application operation. The pumping pressure value Pa (n) generated in order to apply pressure can also be increased (corrected), for example, when the viscosity of the coating liquid increases or clogging occurs in the applicator. Even in the first operation at the start of application, an appropriate amount of the application liquid can be discharged from the applicator to the member to be applied. On the contrary, if the pressure value Pb (n-1) is small, the pressure pressure value Pa (n) is also small (can be corrected), for example, the viscosity of the coating liquid is low. Even in this case, in the first operation at the start of application, an appropriate amount of application liquid can be discharged from the applicator to the member to be applied.

Moreover, it is preferable that the Pb (n-1) in the formula (1) is a pressure value acquired by the pressure sensor in the second operation in the most recent application operation that has been performed.
According to this coating method, it is possible to correct the pressure (pressure feed pressure value) that the pressure feeding means applies to the coating liquid based on the information at the previous (immediately preceding) coating operation. Then, the first operation can be performed using the corrected pressure (pressure feed pressure value) in the next application operation.

  According to the present invention, when the coating operation is repeatedly performed, for example, even if the viscosity of the coating liquid changes or clogging occurs in the coating device, it is difficult to affect the subsequent coating operation. In the first operation at the start of application, an appropriate amount of application liquid is discharged from the applicator to the application target member, and the film thickness defect portion at the application start end can be stably minimized. As a result, the effective area of the member to be coated on which the coating film is formed can be widened to increase productivity.

It is a schematic diagram which shows schematic structure of the coating device of this invention. (A) is a perspective view of an applicator, and (B) is a sectional view of the applicator. It is explanatory drawing of application | coating operation | movement. It is explanatory drawing of application | coating operation | movement. It is explanatory drawing of application | coating operation | movement. It is explanatory drawing of application | coating operation | movement. It is a figure which shows the application | coating start end part of a board | substrate, and is explanatory drawing explaining the subject which invention intends to solve.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a schematic configuration of a coating apparatus 5 of the present invention. The coating apparatus 5 is an apparatus for forming a coating film by discharging a coating liquid onto a member to be coated. The member to be coated in the present embodiment is a strip-shaped substrate W, and a coating film is formed on the substrate W by a coating operation performed by the coating device 5.

The coating apparatus 5 includes an applicator 10 (also referred to as a nozzle or a slit die). The coating liquid is discharged from the applicator 10 and applied to the upper surface of the substrate W. The upper surface of the substrate W is a surface to be coated with the coating liquid, and the substrate W is supported on the stage 9 in a posture in which the surface to be coated faces upward, and coating is performed in this state.
The coating device 5 can supply the coating solution to the coating device 10 at a constant flow rate, as well as the moving device 20 that moves the substrate W and the coating device 10 in addition to the coating device 10 that discharges the coating solution. A certain pump 30, a pressure feeding means 40 that can supply the coating liquid to the coating device 10 by applying pressure to the coating liquid, a control device 50 including a computer that performs various controls, and a pressure for measuring the pressure of the coating liquid Sensor 60.

  The applicator 10 will be described. As shown in FIG. 2A, the applicator 10 is composed of a linear nozzle that is long in one direction, and a discharge port 11 that discharges the coating liquid is provided at the lower end thereof. FIG. 2A is a perspective view of the applicator 10, and FIG. 2B is a cross-sectional view of the applicator 10. The applicator 10 further has a reservoir (also referred to as a manifold) 13 in which the coating liquid is stored, and a slit-like flow path 12 that connects the reservoir 13 and the discharge port 11. The reservoir 13, the slit-shaped flow path 12, and the discharge port 11 are formed long along one direction (a direction orthogonal to the paper surface of FIG. 2B). The reservoir 13 is an area that has been enlarged to temporarily store the coating liquid discharged from the discharge port 11. The lower end of the slit-shaped flow path 12 is a discharge port 11. The coating liquid is discharged downward from the discharge port 11 to the substrate W. During the application operation described later, the reservoir 13 and the slit-like flow path 12 are filled with the coating liquid (that is, filled).

In FIG. 1, the coating apparatus 5 includes an apparatus base 6 and a stage 9 mounted on the apparatus base 6 and placing a substrate W thereon. The coated surface of the substrate W on the stage 9 is horizontal. Then, the substrate W fixed to the stage 9 and the applicator 10 can be relatively moved by the moving means 20.
The moving means 20 of this embodiment includes a rail 21 provided on the apparatus base 6, a movable block 22 that moves in the horizontal direction along the rail 21, and a linear actuator 23 that moves the movable block 22. Yes. The applicator 10 is mounted on the movable block 22. With this moving means 20, the applicator 10 can move in the horizontal direction with respect to the substrate W on the stage 9 in a fixed state. The moving unit 20 may be configured to move the applicator 10 and the substrate W relative to each other in a direction parallel to the surface to be coated of the substrate W. Although not illustrated, the moving unit 20 is not fixed to the applicator 10 in a fixed state. The stage 9 (substrate W) may be moved.

  The moving means 20 includes an elevating actuator 24 that moves the applicator 10 in the vertical direction. Thereby, the height of the applicator 10 (discharge port 11) with respect to the substrate W can be adjusted. The moving means 20 is controlled by the control device 50 and can relatively move the substrate W and the applicator 10 at a predetermined speed (specifically, a constant speed).

  The pump 30 has a function of supplying a coating liquid to the applicator 10. The pump 30 can accurately deliver a coating liquid having an arbitrary flow rate, and is, for example, a syringe pump (metering pump). The applicator 10 and the pump 30 are connected through a first pipe 81, and an open / close switching valve 71 (hereinafter referred to as the first valve 71) is provided in the pipe 81. The pump 30 is controlled by the control device 50, the feeding amount of the coating liquid per unit time is controlled, and a predetermined amount of the coating liquid is supplied to the applicator 10. In the present embodiment, the pump 30 is controlled so that the coating liquid is supplied to the applicator 10 at a constant feed amount. By supplying the coating liquid to the applicator 10 with a constant feed amount by the pump 30, the coating liquid is discharged from the discharge port 11 of the applicator 10 with a constant discharge amount.

  The coating device 5 further includes a tank 35 (hereinafter referred to as a first tank 35) for storing a coating solution. The tank 35 is connected to the pump 30 through a third pipe 83 extended from the first pipe 81. The third pipe 83 is provided with an opening / closing switching valve 73. The volume of the coating liquid that can be stored in the tank 35 is larger than the capacity of the pump 30, and the coating liquid stored in the tank 35 becomes a coating liquid for replenishing the pump 30.

The pressure feeding means 40 includes a tank 41 (hereinafter referred to as a second tank 41) and a pressure regulator 42. The tank 41 stores the coating liquid and is connected to the applicator 10 through the second pipe 82. In the present embodiment, the second pipe 82 is connected to the middle part of the first pipe 81, and the tank 41 is connected to the applicator 10 through the pipes 81 and 82. The second pipe 82 is provided with an open / close switching valve 72 (hereinafter referred to as a second valve 72). When the first valve 71 is open and the second valve 72 is opened, the applicator is applied from the tank 41 to the applicator. 10 (reservoir 13) can be supplied with the coating liquid.
The pressure regulator 42 is composed of a regulator (an electropneumatic regulator connected to a pressure air source), and changes the pressure applied to the coating liquid in the tank 41. The pressure adjuster 42 is controlled by the control device 50 and adjusts the pressure (internal pressure) of the coating liquid in the tank 41. With the second valve 72 closed, the pressure regulator 42 pressurizes the coating solution in the tank 41. Specifically, the application liquid in the tank 41 is pressurized so that the pressure is higher than the pressure of the application liquid in the applicator 10 in a state where the application liquid is supplied by the pump 30. Accordingly, when the first valve 71 is in the open state and the second valve 72 is opened, the coating liquid in the tank 41 can be supplied to the applicator 10 side by a pressure difference. The supply of the coating liquid due to such a pressure difference is called coating liquid feeding.

  As described above, the application liquid is supplied to the applicator 10 by applying pressure to the application liquid in the tank 41 by the pressure feeding means 40. By supplying the coating liquid to the applicator 10 by the pressure feeding means 40, the coating liquid is discharged from the discharge port 11 of the applicator 10. The pressure value generated by the regulator 42 in order to apply pressure to the coating liquid in the tank 41 is referred to as “pressure feeding pressure value”. The pumping pressure value is variable depending on the setting of the control device 50, and the regulator 42 can apply pressure to the coating liquid in the tank 41 with a predetermined pumping pressure value by a command signal from the control device 50.

  The pressure sensor 60 is a sensor that measures the pressure of the coating liquid between the pump 30 and the discharge port 11 of the applicator 10. In the present embodiment, the pressure sensor 60 is provided in the middle of the flow path between the applicator 10 and the first valve 71, and the pressure of the coating liquid between the applicator 10 and the first valve 71 is measured. Measuring. A location where the pressure of the coating liquid is measured by the pressure sensor 60 is referred to as a “pressure measurement target position”. This target position may be another position as long as the pressure of the coating liquid from the pump 30 to the discharge port 11 of the applicator 10 can be measured.

  The control device 50 controls the pump 30 and the pressure feeding means 40 while controlling the moving means 20 (linear actuator 23) to relatively move the substrate W and the applicator 10 at a constant speed. The coating method performed by the coating apparatus 5 provided with the control device 50 includes an operation for starting application of the coating liquid onto the substrate W (hereinafter referred to as a first operation), and subsequent to the start of the application (first operation). The operation performed in this manner includes an operation (hereinafter referred to as a second operation) for discharging the coating liquid from the applicator 10 to the substrate W at a constant discharge amount.

  In the first operation, the coating liquid is supplied to the applicator 10 by the pump 30 and the pressure feeding means 40 in order to apply the coating liquid to the substrate W while relatively moving the substrate W and the applicator 10. That is, in the first operation, a bead is formed between the substrate W and the discharge port 11 in addition to “quantitative discharge” performed by supplying the application liquid to the applicator 10 at a constant flow rate by the pump 30. Therefore, “excess discharge” is performed by supplying an excessive amount of coating liquid to the applicator 10 by the pressure feeding means 40. Thereby, it can prevent that it becomes a bad film thickness in an application | coating start edge part.

  In the second operation, the coating liquid is supplied to the applicator 10 only by the pump 30 in order to apply the coating liquid to the substrate W while relatively moving the substrate W and the applicator 10. That is, in the discharge in the second operation, “quantitative discharge” is performed by supplying the application liquid to the applicator 10 at a constant flow rate by the pump 30.

  As described above, the control device 50 controls the pump 30 and the pressure feeding unit 40 while performing the movement by the moving unit 20 in order to apply the coating liquid to the substrate W. For this reason, the computer program stored in the storage means 51 provided in the control device 50 includes programs for executing the first operation and the second operation. The application operation is performed by executing the program. Note that the storage unit 51 may be provided separately from the control device 50. According to this control device 50, the pump 30 and the pressure feeding means 40 are used in combination to start the coating, and the coating liquid is supplied to the applicator 10, and the coating liquid is supplied by the pressure feeding means 40 after the coating is started. It is possible to control the application operation including the second operation of supplying the application liquid to the applicator 10 using the pump 30 in a state where the operation is stopped.

A coating method performed by the coating apparatus 5 having the above configuration will be described.
Note that the coating apparatus 5 is configured to repeatedly apply the coating solution so that the coated substrate W is replaced with the uncoated substrate W when coating of the coating liquid is finished once on the single substrate W. However, in this embodiment, the substrate W has a strip shape that is long in one direction (coating direction) in which coating is performed and has a constant dimension in the width direction perpendicular to the direction. The case where the application is intermittently repeated will be described. For this reason, a plurality of coating films (application regions) are formed on one strip-shaped substrate W. Of the plurality of coating films (coating regions), the operation of forming the first coating film is the first coating operation, and thereafter, the second coating operation, the third coating operation, and the like are repeatedly performed. . Each application operation is the same.

  For the first coating operation, as shown in FIG. 3, the height position of the applicator 10 is set to a predetermined position with respect to the substrate W on the stage 9. The height adjustment of the applicator 10 is performed by the elevating actuator 24 (see FIG. 1). Further, the applicator 10 is moved by the linear actuator 23 (see FIG. 1) so that the discharge port 11 is positioned immediately above the coating start position (the edge of the substrate W) of the substrate W (the above is referred to as a preparation moving step). ). In this preparation movement process, the valves 71, 72, and 73 are closed.

  Until this preparatory movement process is completed, a process of setting the pressure of the coating liquid in the second tank 41 to a predetermined pressure (hereinafter referred to as a pre-process) is performed. In the pretreatment, in order to set the pressure of the coating liquid in the second tank 41 to a predetermined value, the pressure feeding means 40 (regulator 41) is stored in the second tank 41 at a predetermined pressure pressure value (Pa). Pressure is applied to the coating solution. This pumping pressure value (Pa) is a value set in the control device 50, and increases the pressure of the coating liquid of the applicator 10 connected to the second tank 41 (with the valves 71 and 72 open), It is a value for discharging the coating liquid from the discharge port 11 by this pressure.

  By this pre-processing, at least the second valve 72 is in a closed state until the preparation moving step, and in this state, the pressure of the coating liquid in the second tank 41 affects the pressure of the coating liquid in the applicator 10. Although not described later, when the valves 71 and 72 are opened and the second tank 41 and the applicator 10 communicate with each other, the pressure of the application liquid in the second tank 41 is applied to the application liquid in the applicator 10. The coating liquid in the applicator 10 can be instantaneously pressurized to discharge the coating liquid from the discharge port 11 (the excessive discharge).

Next, a first operation for starting application of the coating liquid onto the substrate W is performed. In this first operation, as shown in FIG. 4, while the applicator 10 and the substrate W are relatively moved by the moving means 20, the application liquid is supplied to the applicator 10 at a constant flow rate by the pump 30, and Then, the coating liquid of the applicator 10 is pressurized by the pressure feeding means 40. For this purpose, the operation of the pump 30 is started after the second valve 72 is first opened. When the acceleration of the pump 30 is completed and the pump speed becomes a constant speed, the first valve 71 is opened. As described above, in the pretreatment, since the pressure feeding means 40 pressurizes the coating liquid in the tank 41 at a predetermined pressure pressure value Pa, the coating liquid in the applicator 10 is discharged at the timing when both the valves 71 and 72 are opened. Apply pressure instantly.
Thereby, the supply of the coating liquid by the pump 30 and the pressurization by the pressure feeding means 40 are simultaneously performed. By this first operation, a bead 3 of the coating liquid is formed between the discharge port 11 and the substrate W (the above is referred to as a first operation step).

When the bead 3 of the coating liquid is formed, the second valve 72 is closed. Since the first valve 71 is maintained in the open state, the supply of the coating liquid by the pump 30 is continuously performed. The operation of closing the second valve 72 is the start of the second operation of discharging the coating liquid from the applicator 10 to the substrate W at a constant discharge amount.
In the second operation, as shown in FIG. 5, the application liquid is supplied to the applicator 10 at a constant flow rate by the pump 30 while the applicator 10 and the substrate W are moved relatively at a constant speed by the moving means 20. Then, the coating liquid is discharged from the discharge port 11 onto the substrate W (the above-mentioned fixed discharge). During this second operation, the pressure sensor 60 detects the pressure of the coating liquid at the target position for pressure measurement. The measurement signal of the pressure sensor 60 is input to the control device 50, and the control device 50 acquires the pressure value Pb of the coating liquid at the target position for pressure measurement and performs correction processing described later.

  Then, when the applicator 10 (discharge port 11) reaches the application end position, the supply of the application liquid by the pump 30 is stopped (see FIG. 6, the above is referred to as a second operation step). The above is the first application operation.

  Here, in the storage unit 51 of the control device 50, the pumping pressure value Pa and the pressure value Pb of the coating liquid at the target position for pressure measurement are stored as reference values. The pumping pressure value Pa as the reference value is a pumping pressure value that is set in the first preliminary operation and used in the pumping means 40 during the first operation included in the coating operation. . Further, the pressure value Pb as the reference value is included in the first application operation, and is a pressure measured by the pressure sensor 60 in a second operation subsequent to the first operation performed by the pumping pressure value Pa. Value.

Then, a second application operation is performed.
This second application operation is the same as the first application operation, and as described above, the preparation movement step (see FIG. 3), the pre-processing, the first operation step (see FIG. 4), and the second operation step. (FIG. 5) is executed. In the first operation of the second coating operation, the pumping pressure value adopted by the pumping means 40 is the same value (Pa) as the previous time. In the second operation of the second coating operation, the pressure sensor 60 The pressure value at the target position for pressure measurement is acquired. That is, the pressurization value of the coating liquid in the tank 41 is the same in the first and second pretreatments. And it is set as the pressure value Pb (2) acquired in the 2nd application | coating operation | movement.

  This pressure value Pb (2) may be different from the pressure value Pb in the first application operation. One of the causes is a change in viscosity (viscosity) of the coating liquid and clogging of the coating liquid. For example, when foreign matter is clogged in the applicator 10, the pressure loss of the coating liquid flowing through the coating device 5 slightly changes. Thus, if a phenomenon that the pressure loss of the coating liquid flowing through the coating apparatus 5 changes (hereinafter referred to as state change) occurs, the pressure feeding means is used during the next (third) coating operation. Even when the coating liquid is pressurized using the same pumping pressure value Pa as before (the first time and the second time) 40, the pressure loss is increased, so the applicator 10 (discharge port 11) is desired. The discharge pressure is not secured, and there is a possibility that the discharge amount is insufficient. That is, it becomes impossible to discharge an appropriate amount of coating liquid from the applicator 10 onto the substrate W, and the range (length) of the film thickness defect portion at the coating start end of the substrate W has reached that (the first time and the first time). May be different from the second time). That is, when the state change occurs, the range (length) of the film thickness defect portion becomes unstable, and the range of the film thickness defect portion may be widened.

  Therefore, the control device 50 performs a correction process for correcting the pumping pressure value in the pumping means 40 every time the coating operation is performed. In the case of the present embodiment, since a change in the pressure value Pb is detected during the second application operation, correction processing is performed for the first operation in the third application operation.

  The correction process will be specifically described. As described above, the storage unit 51 of the control device 50 has already stored the pumping pressure value Pa and the pressure value Pb of the coating liquid at the target position for pressure measurement as reference values. In the previous (second) application operation, the pressure sensor 60 acquires a pressure value Pb (2) that has changed from the previous application operation (first application operation). The pressure value Pb (2) is also stored in the storage unit 51.

In this case, the control device 50 performs the following process. That is, the control device 50 obtains a pumping pressure value Pa (n) that satisfies the following formula (1) for the first operation of the application operation of this time (third time).
Pa (n) = Pa / Pb × Pb (n−1) (1)

Pa (n), Pb (n-1), Pa and Pb in the formula (1) are as follows.
Pa (n): Pressure feed pressure value generated to apply pressure to the coating liquid in the first operation of the third application operation Pb (n-1): Pressure sensor in the second operation executed for the second time The pressure value acquired by 60 (in this embodiment, the pressure value Pb (2))
Pa: a reference value stored in the storage means 51, and a pumping pressure value employed for applying pressure to the coating liquid by the pressure feeding means 40 in the first operation already performed for the first time Pb: storage means 51 is a reference value stored in the pressure value obtained by the pressure sensor 60 in the first second operation that has already been performed. Note that n is a natural number and indicates the number of trials of the coating operation. That is, in this embodiment, n = 3 because the pumping pressure value Pa (n) for the third time is obtained.

Here, compared with the pressure value Pb acquired by the pressure sensor 60 in the already performed coating operation (first coating operation), the coating operation performed next (second coating operation). When the pressure value Pb (2) acquired from the pressure sensor 60 is not changed at the time, that is, when the clogging has not occurred in the applicator 10 or the like and the state change has not occurred, the reference value A certain pressure value Pb and the acquired pressure value Pb (2) are the same (Pb = Pb (2)). For this reason, the pumping pressure value Pa (n) calculated | required by said Formula (1) becomes the same value as the pumping pressure value Pa which is a reference value. In this case, the pumping pressure value employed in the first operation in the third application operation is “Pa” as it is. That is, the correction for changing the pumping pressure value is not performed.
On the other hand, when the state change has occurred and the pressure value Pb which is the reference value is different from the acquired pressure value Pb (2) (Pb <Pb (2)), the equation (1) The required pumping pressure value Pa (n) is larger than the pumping pressure value Pa, which is a reference value. In this case, the pumping pressure value employed in the first operation in the third application operation is “Pa (3)” obtained by the equation (1). That is, the pumping pressure value Pa (3) corrected due to the state change is used in the first operation of the next (third) application operation. Note that “Pa (3)” obtained by the equation (1) is stored in the storage unit 51.

  Thus, even if the state change occurs over time by correcting the pumping pressure value Pa (n) using the value of Pb (n-1) acquired every time the coating operation is finished, A pumping pressure value Pa (n) corrected according to the state change is obtained. Further, here, the pumping pressure value Pa (n) is obtained from the product of Pb (n−1) and the correction coefficient Pa / Pb, and the reference value Pb value among the correction coefficients is the first second operation. However, the present invention is not limited to this, and the value of the correction coefficient Pa / Pb may be determined in advance based on past application knowledge.

As described above, in the coating method performed by the coating apparatus 5 according to the present embodiment, the substrate W and the coating device 10 are moved relative to each other by the moving unit 20 and applied to the substrate W using the pump 30 and the pressure feeding unit 40. A coating operation for coating the liquid is performed. In particular, in this coating operation, the first operation for supplying the coating liquid to the applicator 10 by using the pump 30 and the pressure feeding means 40 together to start the coating, and the supply of the coating liquid by the pressure feeding means 40 after the coating is started. And a second operation of supplying the coating liquid to the applicator 10 using the pump 30 in a state where the operation is stopped. Therefore, the control device 50 corrects the pressure applied by the pressure feeding means 40 to the coating liquid using the pressure value acquired by the pressure sensor 60 in the second operation, and uses the corrected pressure to perform the subsequent coating operation. The first operation in is performed.
That is, in the second operation, the pump 30 supplies the application liquid to the applicator 10 with a constant feed amount, and the application liquid is discharged from the discharge port 11 with a constant discharge amount from the applicator 10. The control device 50 monitors the pressure change for each coating operation by measuring the pressure of the coating liquid at the pressure measurement target position with the pressure sensor 60. When the pressure change occurs, control is performed so that the discharge amount of the coating liquid discharged from the applicator 10 is not changed by the pumping by the pumping means 40 by correcting the pumping pressure value by the pumping means 40. ing.

  In order to perform this correction, the storage means 51 stores the pressure feed pressure value generated by the pressure feed means 40 to apply pressure to the coating liquid in the tank 41 and the pressure value acquired by the pressure sensor 60. The And the control apparatus 50 performs 1st operation | movement in subsequent application | coating operation | movement using the value memorize | stored in this memory | storage means 51, and the pumping pressure value Pa (n) which satisfy | fills said Formula (1). .

According to this configuration, if the pressure value Pb (n−1) acquired by the pressure sensor 60 in the second operation in the applied application operation is large, the application liquid is used in the first operation in the subsequent application operation. It is also possible to increase (correct) the pumping pressure value Pa (n) generated in order to apply pressure. For example, even when the viscosity of the coating liquid flowing through the coating device 5 becomes high or clogging occurs in the coating device 10, an appropriate amount of coating liquid is applied from the coating device 10 in the first operation at the start of coating. Can be discharged onto the substrate W.
On the other hand, if the pressure value Pb (n-1) is small, the pumping pressure value Pa (n) is small (can be corrected), for example, the viscosity of the coating liquid is low. Even in this case, an appropriate amount of the coating liquid can be discharged from the applicator 10 to the member to be coated in the first operation at the start of coating.

  As described above, the control device 50 corrects the pressure applied to the coating liquid by the pressure feeding unit 40 using the pressure value (Pb (n−1)) acquired by the pressure sensor 60 in the second operation, and corrects the correction. Since the first operation in the subsequent application operation is performed using this pressure, the viscosity of the application liquid when the application operation is repeated first, second, third ... Even if the change occurs or clogging occurs in the applicator, it is possible to make it difficult to influence the subsequent application operation. Therefore, in the first operation at the start of application, an appropriate amount of application liquid can be discharged from the applicator 10 to the substrate W, and the defective film thickness portion can be stably minimized at the application start end of the substrate W. Is possible. As a result, the effective area of the substrate W can be widened to increase productivity.

  For example, even when a foreign substance is clogged in the applicator 10 or the like, the reason why it is possible to perform coating for obtaining a stable film thickness on the substrate W during the subsequent coating operation is as follows. It is as follows. That is, when foreign matter is clogged in the applicator 10 or the like during the second operation, the pressure detected by the pressure sensor 60 increases. Therefore, the output (pressure-feeding pressure value) by the pressure-feeding means 40 at the start of the application of the next substrate W is set (corrected) based on the pressure value measured by the pressure sensor 60. Thereby, a coating liquid is discharged from the applicator 10 with a desired pressure, and a stable film thickness can be obtained. If such correction is not performed, even if foreign matter is clogged in the applicator 10 or the like, if the output by the pressure feeding means 40 (pressure feed pressure value) is constant (when correction is not performed), clogging occurs. The desired discharge is not performed due to the pressure loss, resulting in insufficient coating liquid.

  In particular, in this embodiment, in order to correct the pumping pressure value in the first operation of the third application operation, the pressure value acquired by the pressure sensor 60 in the second operation of the second application operation is used. Correction according to the equation (1) is performed. That is, the Pb (n−1) in the equation (1) is a pressure value acquired by the pressure sensor 60 in the second operation in the most recent application operation that has been performed. Thereby, the pressure (pressure feed pressure value) for the pressure feeding means 40 to apply to the coating liquid can be corrected based on the information in the previous (immediately preceding) coating operation. Then, the first operation can be performed using the corrected pressure (pressure feed pressure value) in the next application operation. As a result, even if the state change has occurred, the pumping pressure value corresponding to the change is quickly set, and appropriate excessive discharge can be performed.

The embodiments disclosed above are illustrative in all respects and not restrictive. That is, the coating device 5 of the present invention is not limited to the illustrated form, and may be in another form within the scope of the present invention.
In the above-described embodiment, the member to be coated has been described as the belt-like substrate W that is long in one direction (coating direction) in which coating is performed and has a constant dimension in the width direction perpendicular to the one direction. The substrate W may be a single wafer. In this case, the coating apparatus 5 that continuously produces the substrate W by replacing the substrate W every time the coating operation is performed on the sheet-like substrate W may be used.

5: coating device 10: applicator 11: discharge port 20: moving means 30: pump 40: pressure feeding means 50: control device 51: storage means 60: pressure sensor W: substrate (member to be coated)

Claims (6)

An applicator having a discharge port for discharging a coating liquid to a member to be coated;
Moving means for relatively moving the applicator and the coated member in a direction parallel to the coated surface of the coated member;
A pump capable of supplying a predetermined amount of coating liquid to the applicator;
A pumping means capable of supplying the coating liquid to the coating device by applying pressure to the coating liquid;
A control device for controlling the pump and the pressure feeding means while performing the relative movement by the moving means in order to apply a coating liquid to the member to be coated;
A pressure sensor for measuring the pressure of the coating liquid between the pump and the discharge port;
With
The control device stops the supply of the coating liquid by the pressure feeding means after the first operation for supplying the coating liquid to the applicator by using the pump and the pressure feeding means together for starting the coating. A second operation of supplying a coating liquid to the applicator using the pump in a state, and control of the coating operation can be executed.
The control device further corrects the pressure applied to the coating liquid by the pressure feeding unit using the pressure value acquired by the pressure sensor in the second operation, and uses the corrected pressure to perform the subsequent coating operation. The coating apparatus which performs said 1st operation | movement in. A storage unit capable of storing a pressure-feeding pressure value generated to apply pressure to the coating liquid by the pressure-feeding unit, and a pressure value acquired by the pressure sensor;
The said control apparatus is a coating device of Claim 1 which can perform said 1st operation | movement in subsequent application | coating operation | movement using the pumping pressure value Pa (n) which satisfy | fills following formula (1).
Pa (n) = Pa / Pb × Pb (n−1) (1)
However,
Pa (n): a pumping pressure value generated in order to apply pressure to the coating liquid in the first operation of the subsequent application operation Pb (n-1): acquired by the pressure sensor in the executed second operation Pressure value Pa: a reference value stored in the storage means, and a pressure-feeding pressure value for applying pressure to the coating liquid by the pressure-feeding means Pb: a reference value stored in the storage means, Pressure value acquired by the pressure sensor in the second operation   3. The coating apparatus according to claim 2, wherein the Pb (n−1) in the formula (1) is a pressure value acquired by the pressure sensor in the second operation in the most recent coating operation performed. An applicator having a discharge port for discharging a coating liquid to a member to be coated; a moving means for relatively moving the applicator and the member to be coated in a direction parallel to a surface to be coated of the member to be coated; A pump capable of supplying a constant amount of coating liquid to the applicator, a pressure feeding means capable of supplying the coating liquid to the applicator by applying pressure to the coating liquid, and a space between the pump and the discharge port A pressure sensor for measuring the pressure of the coating liquid, and a coating method performed by a coating apparatus comprising:
While performing the relative movement by the moving means, performing a coating operation to apply a coating liquid to the coated member using the pump and the pressure feeding means,
In the coating operation, the first operation of supplying the coating liquid to the applicator by using the pump and the pressure feeding means together for starting the coating, and stopping the supply of the coating liquid by the pressure feeding means after the coating is started. A second operation of supplying a coating liquid to the applicator using the pump in a state where
Using the pressure value acquired by the pressure sensor in the second operation, the pressure applied by the pumping means to the coating liquid is corrected, and the first operation in the subsequent coating operation is executed using the corrected pressure. Application method. The coating apparatus further includes a storage unit capable of storing a pressure-feeding pressure value generated in order to apply pressure to the coating liquid by the pressure-feeding unit, and a pressure value acquired by the pressure sensor,
The coating method according to claim 4, wherein the first operation in a subsequent coating operation can be performed using a pumping pressure value Pa (n) that satisfies the following expression (1).
Pa (n) = Pa / Pb × Pb (n−1) (1)
However,
Pa (n): a pumping pressure value generated in order to apply pressure to the coating liquid in the first operation of the subsequent application operation Pb (n-1): acquired by the pressure sensor in the executed second operation Pressure value Pa: a reference value stored in the storage means, and a pressure-feeding pressure value for applying pressure to the coating liquid by the pressure-feeding means Pb: a reference value stored in the storage means, Pressure value acquired by the pressure sensor in the second operation   6. The coating method according to claim 5, wherein the Pb (n−1) in the formula (1) is a pressure value acquired by the pressure sensor in the second operation in the most recently performed coating operation.

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