CN108698073B

CN108698073B - Coating device and coating method

Info

Publication number: CN108698073B
Application number: CN201780012441.5A
Authority: CN
Inventors: 谷义则; 冈本俊一; 伊藤俊文; 铃木晓雄
Original assignee: Toray Engineering Co Ltd
Current assignee: Toray Engineering Co Ltd
Priority date: 2016-02-26
Filing date: 2017-02-01
Publication date: 2021-06-11
Anticipated expiration: 2037-02-01
Also published as: KR20180116300A; TW201741036A; CN108698073A; WO2017145675A1; JP6804850B2; TWI735539B; JP2017148769A

Abstract

The invention aims to make the thickness of a coating film coated on a coated part to be a desired thickness. An applicator (10) of an application device (5) has a reservoir (13) for accumulating an application liquid, an ejection port (11) for ejecting the application liquid, and a slit-shaped flow path (12) connecting the reservoir (13) and the ejection port (11), and the applicator (10) ejects the application liquid from the ejection port (11) toward a substrate (7). The coating device (5) comprises: a moving means (20) for moving the applicator (10) relative to the substrate (7) in a direction parallel to the surface (8) to be coated; a pump (30) that supplies the coating liquid to the applicator (10); and a control device (50). The control device (50) is configured to: when a coating operation is performed in which the coating liquid is discharged from the discharge port (11) to the substrate (7) while the coater (10) is moving, control is performed for causing the coating liquid in the coater (10) to be at a negative pressure and supplying the coating liquid from the pump (30) to the coater (10).

Description

Coating device and coating method

Technical Field

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

Background

As a coating apparatus for forming a coating film with a uniform thickness on a member to be coated (for example, a circular substrate such as a silicon wafer), a slot coater and a spin coater are known, and their characteristics are different, and the application is expanded depending on the characteristics.

The slot coater is used, for example, to form a coating film on a color filter or a TFT substrate of a liquid crystal display. The slot coater can also cope with a large glass substrate, and exhibits a characteristic of high utilization efficiency of the coating liquid (i.e., less waste of the coating liquid).

A spin coater is inferior to a slot coater in terms of efficiency in utilizing a large substrate or a coating liquid, but a coating film having a uniform thickness can be relatively easily formed on a circular substrate such as a silicon wafer, and is widely used in the field of semiconductor production.

However, in recent years, in the field of semiconductor production, a slot coater has been used in order to improve the utilization efficiency of the coating liquid (see, for example, patent documents 1 and 2). The slot coater has an applicator (also referred to as a nozzle or a slot die) in which a slot-like flow path is formed, and the tip thereof serves as a discharge port for the coating liquid. The ejection orifice has an elongated shape having a width dimension larger than the diameter of a circular substrate (silicon wafer).

The substrate and the coater (the discharge port) are relatively moved in a state where they are opposed to each other, and the coating liquid (the liquid bead of the coating liquid) generated between the substrate and the coater is used for discharging (sucking) the coating liquid from the discharge port. Therefore, the coating liquid is ejected (sucked) at a portion where the substrate faces the elongated ejection port, whereas the coating liquid is not ejected (sucked) at a portion where the substrate is not present. As a result, a coating film is formed on a necessary portion of a circular substrate such as a silicon wafer without unnecessarily consuming the coating liquid, and the utilization efficiency of the coating liquid can be improved.

In addition, such a slot coater (also referred to as a capillary coater) has conventionally been configured such that the discharge port of the coater is directed upward, but as disclosed in patent documents 1 and 2, a slot coater having a discharge port directed downward has been proposed. In this slot coater, the discharge port of the coater is directed downward, and control is performed to maintain the pressure (internal pressure) of the coating liquid in the coater at a negative pressure. Then, the coating liquid (liquid bead of the coating liquid) generated between the substrate and the coater is sucked out of the coater by the surface tension of the coating liquid, and the coating liquid is efficiently applied to a circular substrate such as a silicon wafer.

Further, the advantage of having the ejection port face downward is that the application surface of the substrate can be made to face upward, whereby the handling of the substrate becomes simple and the flow of the liquid after application can be suppressed.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-98371

Patent document 2: japanese patent laid-open publication No. 2015-192984

Disclosure of Invention

Problems to be solved by the invention

When a coating liquid is applied to a substrate using a capillary coater having a discharge port of the coater directed downward, the main control parameters affecting the film thickness of the coating liquid are the pressure in the coater and the coating speed. Even if coating is performed by controlling using these control parameters, highly accurate control is required in order to stably reproduce the film thickness.

The capillary applicator described in patent document 1 has the following structure: a narrow accumulation chamber for accumulating the coating liquid is formed inside the applicator, and the pressure (air pressure) of the accumulation chamber is controlled. When the coating liquid in the accumulation chamber is ejected from the ejection port, that is, when the coating liquid is consumed by coating, the liquid level of the coating liquid in the accumulation chamber is lowered. A new coating liquid is supplied to the applicator (accumulation chamber) from the outside, but since the accumulation chamber is narrow, the fluctuation of the liquid level is large as the coating liquid is consumed (and supplied), and as a result, control to keep the pressure of the accumulation chamber constant is practically difficult.

The capillary applicator described in patent document 2 includes a container for storing the coating liquid, which is connected to the applicator via a pipe, and the pressure in the container is feedback-controlled based on a measurement value of a pressure sensor provided in the applicator so that the pressure in the applicator is constant. However, the movement of the coating liquid is slow due to a pressure loss generated when the coating liquid flows through a flow path (pipe) from the container to the applicator, and the response of the control may be lowered. That is, even if the pressure of the container is controlled, a time lag occurs until the pressure change based on the control is reflected in the pressure inside the applicator, and as a result, there is a problem in that: the pressure in the applicator does not become a desired pressure or the pressure in the applicator fluctuates.

As described above, when the control of the pressure in the coater is unstable, the discharge amount of the coating liquid discharged from the coater varies, and as a result, the film thickness of the coating film formed on the member to be coated may become uneven.

The present invention has been made to solve the above-described problems of the capillary coater (capillary coating), and an object thereof is to provide a coating apparatus and a coating method capable of making the thickness of a coating film formed on a member to be coated a desired thickness.

Means for solving the problems

The coating device of the invention comprises: an applicator having an accumulation portion where the coating liquid is accumulated, an ejection port from which the coating liquid is ejected, and a slit-shaped flow path connecting the accumulation portion and the ejection port, the applicator ejecting the coating liquid from the ejection port to the 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 that supplies a coating liquid to the applicator; and a control device that performs control for making the coating liquid in the coater negative pressure and supplying the coating liquid from the pump to the coater when performing a coating operation of discharging the coating liquid from the discharge port to the member to be coated while performing the relative movement.

According to this coating apparatus, capillary coating can be performed, and a coating film having a desired thickness can be formed on a member to be coated (surface to be coated) by discharging a coating liquid from a discharge port.

Further, the control device may perform control such that, when the coating operation is performed: supplying a coating liquid corresponding to an amount of the coating liquid to be ejected from the ejection port from the pump to the applicator.

According to this configuration, since the coating liquid corresponding to the amount of the coating liquid to be consumed by being discharged from the discharge port is supplied from the pump to the coater during the coating operation, the capillary coating control is easily performed, and a coating film having a desired thickness is formed on the member to be coated (the surface to be coated).

In addition, the coating device further includes: a pressure applying device for applying pressure to the coating liquid in the coater; and a pressure sensor that measures a pressure of the coating liquid in the coater, wherein the control device performs pressure control of the coating liquid in the coater by the pressure applying device in order to maintain the coating liquid in the coater at a negative pressure, and performs adjustment control of the coating liquid by the pump according to a measurement result of the pressure sensor.

According to this configuration, the capillary coating can be easily controlled by performing pressure control for keeping the pressure (negative pressure) in the coater constant, and a coating film having a desired thickness can be formed on the member to be coated (surface to be coated).

In addition, when the coating liquid is allowed to adhere to the coating start section of the member to be coated, it is preferable to appropriately control the ejection rate of the coating liquid so as to obtain a desired film thickness from the coating start section. Therefore, it is preferable that the control device stops the supply of the coating liquid by the pump when a decrease in the pressure is detected after the coating liquid is supplied to the applicator by the pump and the pressure of the coating liquid in the applicator is increased by the supply in order to perform the liquid adhesion operation for starting the adhesion of the coating liquid to the member to be coated.

When the supply of the coating liquid from the pump to the applicator is performed, the pressure of the coating liquid in the applicator is temporarily increased, thereby ejecting the coating liquid from the ejection port. When the coating liquid comes into contact with the member to be coated, the coating liquid in the coater is further sucked out by the surface tension of the coating liquid, and the pressure in the coater is thereby reduced. Therefore, when the pressure decrease is detected, the supply of the coating liquid by the pump is stopped, and the excessive coating liquid can be prevented from adhering to the member to be coated during the liquid adhesion operation.

In order to perform the liquid adhesion operation, it is preferable that the coating apparatus further includes: a container connected to the applicator via a pipe, the container storing a coating liquid; a pressure regulator for regulating the pressure of the coating liquid accumulated in the container so as to maintain the pressure of the coating liquid in the applicator at a prescribed value; and a valve capable of communicating and shutting off the applicator with the container, wherein the control device stops the supply of the coating liquid by the pump and operates the valve to communicate the container with the applicator when the pressure decrease is detected after the coating liquid is supplied to the applicator by the pump in a state where the communication of the applicator with the container is shut off by the valve.

According to this configuration, the pressure of the coating liquid in the applicator can be maintained at a constant value (negative pressure) after the coating liquid discharged from the discharge port adheres to the member to be coated during the liquid adhesion operation.

Further, the coating method of the present invention is a coating method for performing capillary coating by discharging a coating liquid from a discharge port of an applicator having a reservoir portion for accumulating the coating liquid, the discharge port from which the coating liquid is discharged, and a slit-shaped flow path connecting the reservoir portion and the discharge port, the coating method performing the following coating operation: the coating device is configured to discharge the coating liquid from the discharge port to the member to be coated while relatively moving the applicator and the member to be coated in a direction parallel to the surface to be coated of the member to be coated, and to supply the coating liquid to the applicator from a pump connected to the applicator while the coating liquid in the applicator is brought into a negative pressure during the coating operation.

According to this coating method, capillary coating can be performed, and a coating liquid can be discharged from the discharge port to form a coating film having a desired thickness on a member to be coated (surface to be coated).

In addition, at the time of the coating operation, a coating liquid corresponding to an amount of the coating liquid to be ejected from the ejection port is supplied from the pump to the applicator.

Further, the pressure of the coating liquid in the coater is measured by a pressure sensor, the pressure control of the coating liquid in the coater is performed to maintain the coating liquid in the coater at a negative pressure, and the adjustment control of the coating liquid by the pump is performed based on the measurement result of the pressure sensor.

In addition, when the coating liquid is allowed to adhere to the coating start section of the member to be coated, it is preferable to appropriately control the ejection rate of the coating liquid so as to obtain a desired film thickness from the coating start section. Therefore, after the application liquid is supplied to the applicator by the pump in order to perform the liquid adhesion action of starting adhesion of the application liquid to the member to be coated and the pressure of the application liquid in the applicator is increased by the supply, when the pressure decrease is detected, the supply of the application liquid by the pump is stopped.

When the supply of the coating liquid from the pump to the applicator is performed, the pressure of the coating liquid in the applicator is temporarily increased, thereby ejecting the coating liquid from the ejection port. When the coating liquid comes into contact with the member to be coated, the coating liquid in the coater is further sucked out by the surface tension of the coating liquid, and the pressure in the coater is thereby reduced. Therefore, when the pressure drop is detected, the supply of the coating liquid by the pump is stopped, and the excessive coating liquid can be prevented from adhering to the member to be coated when the liquid adhesion operation is performed.

In order to perform the liquid adhesion operation, it is preferable that a container in which the coating liquid is stored is connected to the applicator via a pipe, a valve capable of connecting and disconnecting the applicator to and from the container is provided, the pressure of the coating liquid stored in the container is adjusted by a pressure adjuster so that the pressure of the coating liquid in the applicator is maintained at a predetermined value, and when a decrease in the pressure is detected after the coating liquid is supplied to the applicator by the pump in a state where the communication between the applicator and the container is disconnected by the valve, the supply of the coating liquid by the pump is stopped, and the valve is operated so that the container and the applicator are connected to each other.

Effects of the invention

According to the present invention, the amount of the coating liquid supplied to the applicator is controlled to a prescribed amount by the pump, so that the amount of the coating liquid to be ejected from the ejection port to the outside of the applicator due to the surface tension of the coating liquid ejected from the applicator to the member to be coated can be suppressed. As a result, the coating liquid in the coater can be maintained at a negative pressure during the coating operation, and the thickness of the coating film applied to the member to be coated can be set to a desired thickness.

Drawings

Fig. 1 is a schematic configuration diagram illustrating the overall configuration of the coating apparatus.

Fig. 2 is an explanatory view of the coater and the substrate.

Fig. 3 is an explanatory view for explaining the coating method.

Fig. 4 is an explanatory view for explaining the coating method.

Fig. 5 is an explanatory view for explaining the coating method.

Fig. 6 is an explanatory view for explaining the coating method.

Detailed Description

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

[ Structure of coating apparatus ]

Fig. 1 is a schematic configuration diagram illustrating the overall configuration of the coating apparatus. The coating apparatus 5 is an apparatus for forming a coating film having a uniform thickness by discharging a coating liquid to a single-piece member to be coated, for example. The member to be coated described in the present embodiment is a circular substrate 7 (see fig. 2 a), specifically, a circular silicon wafer.

The coating device 5 has a coater 10 (also referred to as a nozzle or a slit die) located above the substrate 7, and discharges a coating liquid from the coater 10 to coat the upper surface of the substrate 7 with the coating liquid. The upper surface of the substrate 7 becomes a surface 8 to be coated with the coating liquid, and the coating is performed in this state with the substrate 7 supported on the stage 9 in a posture in which the surface 8 to be coated faces upward.

The coating device 5 includes, in addition to the applicator 10 that discharges the coating liquid: a moving unit 20 that moves the substrate 7 and the coater 10 relative to each other; a pump 30 for supplying the coating liquid to the applicator 10; a pressure applying device 40 for applying pressure to the coating liquid in the coater 10; a control device 50 configured by a computer that performs various controls; and a pressure sensor 60 for measuring the pressure of the coating liquid in the applicator 10.

The applicator 10 will be described. As shown in fig. 2 (a), the applicator 10 is configured by a linear nozzle long in one direction, and a discharge port 11 long in one direction for discharging the coating liquid is provided at a lower end of the applicator 10. As described above, the substrate 7 (the coated surface 8) is circular, and the ejection port 11 has a width dimension W (W > D) larger than the diameter D of the substrate 7 (the maximum dimension of the substrate 7 in the one direction). Therefore, a portion where the substrate 7 is present directly below and a portion where the substrate 7 is not present directly below are generated in the coater 10 (the ejection port 11), and further, the respective ranges (lengths) of these portions vary depending on the relative positions of the substrate 7 and the coater 10 (the ejection port 11). Fig. 2 (a) is a perspective view showing the coater 10 and the substrate 7, fig. 2 (B) is a cross-sectional view of a portion of the coater 10 where the substrate 7 is present, and fig. 2 (C) is a cross-sectional view of a portion of the coater 10 where the substrate 7 is not present.

As shown in fig. 2 (B) and (C), the applicator 10 includes a reservoir 13 for accumulating the coating liquid, an ejection port 11 for ejecting the coating liquid, and a slit-shaped flow path 12 connecting the reservoir 13 and the ejection port 11. These reservoir 13, slit-shaped flow path 12, and discharge port 11 are formed long in one direction (a direction perpendicular to the paper surface of fig. 2 (B) and (C)). The accumulation portion 13 is an area enlarged to temporarily accumulate the coating liquid to be discharged from the discharge port 11. The lower end of the slit-shaped flow path 12 serves as an ejection port 11. In the coater 10, the coating liquid is discharged downward from the discharge port 11 toward the substrate 7. When a coating operation described later is performed, the reservoir 13 and the slit-shaped flow path 12 are in a state of being filled with the coating liquid (i.e., a filled state). In the present embodiment, the direction of discharging the coating liquid from the discharge port 11 is downward, but the direction is not limited thereto, and may be obliquely downward, or may be laterally (horizontally), upward, or obliquely upward.

In fig. 1, the pressure sensor 60 is a sensor provided in the applicator 10 to measure the pressure of the coating liquid inside the applicator 10. In the present embodiment, the detection portion (sensor portion) of the pressure sensor 60 is exposed to the accumulation portion 13, and measures the pressure (internal pressure) of the coating liquid in the accumulation portion 13. The measurement result of the pressure sensor 60 is input to the control device 50. In addition, hereinafter, "the pressure inside the applicator 10" refers to the pressure of the coating liquid of the reservoir 13.

The coating device 5 includes a device base 6 and a stage 9, the stage 9 is mounted on the device base 6, and the substrate 7 is placed on the stage 9. The coated surface 8 of the substrate 7 on the stage 9 is horizontal. In the present embodiment, the applicator 10 is movable relative to the stage 9 by the moving unit 20.

The mobile unit 20 includes: a rail 21 provided on the device 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. The applicator 10 is mounted on the movable block 22. The moving unit 20 allows the coater 10 to move in the horizontal direction with respect to the substrate 7 on the stage 9 in a fixed state. The moving means 20 may be any structure as long as it relatively moves the applicator 10 and the substrate 7 in a direction parallel to the surface 8 of the substrate 7 to be applied, and may be a structure that moves the stage 9 (substrate 7) relative to the applicator 10 in a fixed state, although not shown. The moving unit 20 includes a lift actuator 24 that moves the applicator 10 in the vertical direction. This allows adjustment of the height of the applicator 10 (discharge port 11) relative to the substrate 7. The moving unit 20 is controlled by the control device 50, and can move the applicator 10 in the horizontal direction at a predetermined speed (specifically, a constant speed).

In the coating apparatus 5, the substrate 7 and the coater 10 (the discharge port 11) are relatively moved by the moving means 20 in a state where they are opposed to each other in the vertical direction, and the coating liquid (the liquid beads 3 of the coating liquid) is discharged from the coater 10 by the surface tension generated between the substrate 7 and the coater 10 and acting on the coating liquid. Therefore, the coating liquid is discharged at a portion where the substrate 7 is present with respect to the elongated discharge port 11 as shown in fig. 2 (B), whereas the coating liquid is not discharged at a portion where the substrate 7 is absent with respect to the discharge port 11 as shown in fig. 2 (C). Thus, when the circular substrate 7 is to be coated, a coating film can be formed on a necessary portion without wasting the coating liquid, and the utilization efficiency of the coating liquid can be improved.

In fig. 1, the pump 30 has a function of supplying a desired amount of coating liquid to the applicator 10. The pump 30 can accurately deliver a coating liquid at an arbitrary flow rate, and the pump 30 is, for example, a syringe pump (fixed displacement pump). The applicator 10 and the pump 30 are connected by a pipe 81, and the pipe 81 is provided with an opening/closing switching valve 71. The pump 30 is controlled by the control device 50 to supply the coating liquid to the coater 10 by controlling the amount of the coating liquid to be fed per unit time. The applicator 10 is supplied with the coating liquid by the pump 30, and the coating liquid is discharged from the discharge port 11 of the applicator 10. The pump 30 may suck the coating liquid on the applicator 10 side by performing an operation reverse to the operation for supplying the coating liquid. This suction operation is performed when the pump 30 is replenished with the coating liquid and in the control mode (the second mode), which will be described later.

The coating device 5 further includes a container (first container) 35 for accumulating the coating liquid. The container 35 is connected to the pump 30 via a pipe 83 extending from the pipe 81. The pipe 83 is provided with an open/close switching valve 73. The volume of the coating liquid that can be stored in the container 35 is larger than the volume of the pump 30, and the coating liquid stored in the container 35 becomes the coating liquid to be replenished to the pump 30.

The pressure applying device 40 includes a container (second container) 41 and a pressure regulator 42. The container 41 stores the coating liquid and is connected to the applicator 10 via a pipe 82. The pipe 82 is provided with an open/close switching valve 72, and the coating liquid can flow between the container 41 and the applicator 10 (reservoir 13) in a state where the valve 72 is open. The valve 72 enables the spreader 10 to be communicated with and shut off from the second container 41. The capacity of the coating liquid that can be stored in the container 41 is larger than the capacity (volume) of the storage section 13 of the applicator 10.

The pressure regulator 42 is composed of a regulator, and changes the pressure of the coating liquid acting on the container 41. The pressure regulator 42 is controlled by the control device 50 to regulate the pressure (internal pressure) of the coating liquid in the container 41. Since the container 41 and the applicator 10 are connected by the pipe 82, the pressure of the coating liquid in the applicator 10 (the reservoir 13) can be controlled to a predetermined pressure by adjusting the pressure of the coating liquid in the container 41. For example, the pressure (gauge pressure) of the coating liquid in the applicator 10 (accumulation section 13) can be made negative by adjusting the pressure (gauge pressure) of the coating liquid in the container 41 to negative pressure.

As described above, in the present embodiment, the pressure regulator 42 is configured to regulate the pressure of the coating liquid stored in the container 41 so that the pressure of the coating liquid in the applicator 10 is maintained at a predetermined value (negative pressure), and the pressure regulator 42 and the container 41 constitute the pressure applying device 40, and the pressure applying device 40 applies the pressure (negative pressure) to the coating liquid in the applicator 10.

The coating apparatus 5 having the above configuration includes a pump control line L1 and a pressure control line L2 connected to the coater 10, respectively. The pump control line L1 includes

pipes

81 and 83,

valves

71 and 73, a pump 30, and a first tank 35. The pressure control line L2 includes a pipe 82, a valve 72, a second tank 41, and a pressure regulator 42. In the coating operation and the liquid adhesion operation described later, one or both of the pump control line L1 and the pressure control line L2 are selectively used.

The coating device 5 of the present embodiment has two control modes for performing the coating operation, and can be alternatively employed. Therefore, the computer program stored in the storage unit of the control device 50 includes programs of two control modes and can be selectively executed. The coating operation is an operation of discharging the coating liquid from the discharge port 11 to the substrate 7 while the substrate 7 and the coater 10 are relatively moved by the moving means 20 (linear actuator 23).

Hereinafter, a coating method by the coating apparatus 5 having the above-described structure will be described. The coating method includes a liquid adhesion operation for starting adhesion of the coating liquid to the substrate 7, and then the coating operation is performed by the liquid adhesion operation.

[ control mode (one of them) ]

Fig. 3 to 5 are explanatory views for explaining the coating method. In the following description, the valve 71 between the pump 30 and the applicator 10 is referred to as a first valve 71, the valve 72 between the second tank 41 and the applicator 10 is referred to as a second valve 72, and the valve 73 between the first tank 35 and the pump 30 is referred to as a third valve 73.

As shown in fig. 3 a, initial dispensing of the coating liquid is performed from the coater 10 (initial dispensing step). Therefore, the pump 30 is operated with the first valve 71 opened, and a small amount of the coating liquid is discharged from the discharge port 11. In this initial liquid discharge process, the coater 10 is not present on the substrate 7.

Then, the discharge port 11 of the applicator 10 is wiped (wiping step: see FIG. 3B). At this time, the pump 30 is stopped.

Next, the height position of the coater 10 is set to a predetermined position with respect to the substrate 7 on the stage 9. The height of the coater 10 is adjusted by a lift actuator 24 (see fig. 1). For example, the distance between the ejection port 11 and the surface 8 to be coated is set to several tens μm. The coater 10 is moved by the linear actuator 23 (see fig. 1) so that the discharge port 11 is positioned directly above the coating start position of the substrate 7 (edge portion of the substrate 7) (preparatory movement step).

Until the preparation movement step is completed, the following processing (hereinafter referred to as "prior processing") is performed: the pressure of the coating liquid in the second container 41 is set to be lower than the atmospheric pressure.

In the preliminary processing, the pressure of the coating liquid in the second container 41 is set to a predetermined reduced pressure value (predetermined negative pressure value) in the pressure control line L2. The reduced pressure value (negative pressure value) is set in the control device 50, and is a value for setting the pressure of the coating liquid in the coater 10 to a predetermined negative pressure value. Specifically, this value is the same as the negative pressure value generated by the coating liquid of the coater 10 during the coating operation. The negative pressure (reduced pressure) of the coating liquid in the second container 41 is performed by the pressure regulator 42. The above processing is prior processing.

By this preliminary processing, the second valve 72 is closed until the preparation movement step, and in this state, the pressure of the coating liquid in the second container 41 does not affect the pressure of the coating liquid in the applicator 10, and as will be described later, the negative pressure of the coating liquid in the second container 41 is applied to the pressure of the coating liquid in the applicator 10 by opening the second valve 72, so that the pressure of the coating liquid in the applicator 10 can be instantaneously made negative.

Next, the pump 30 is operated to supply the coating liquid to the coater 10 (see fig. 4 a). At this time, the supply amount of the coating liquid by the pump 30 is an extremely small amount, and is smaller than the supply amount at the time of the coating operation. Thereby, a small amount of the coating liquid is discharged from the discharge port 11. Further, the pressure of the coating liquid in the applicator 10 is increased to approach the atmospheric pressure by the supply of the coating liquid by the pump 30.

When a slight amount of the coating liquid discharged from the discharge port 11 comes into contact with the substrate 7 (see fig. 4B), the pressure in the applicator 10 is rapidly reduced (returns to a negative pressure lower than the atmospheric pressure). This is because the coating liquid in the coater 10 is sucked out to the substrate 7 side due to the surface tension of the coating liquid in contact with the substrate 7 and capillary phenomenon (capillarity).

The pressure sensor 60 measures the pressure inside the applicator 10 at every moment, and therefore opens the second valve 72 when a decrease in pressure inside the applicator 10 due to contact of the coating liquid with the substrate 7 is detected in the control device 50 (see fig. 4 (C)). In addition, the supply of the coating liquid by the pump 30 is stopped. Thereby, in cooperation with the preliminary treatment, the coating liquid of the applicator 10 is influenced by the pressure of the coating liquid of the second container 41, and the pressure of the coating liquid of the applicator 10 becomes a negative pressure. As a result, the coating liquid is prevented from flowing out of the coater 10, and the liquid beads 3 formed by the coating liquid are formed between the substrate 7 and the discharge port 11 (see fig. 4C).

The steps shown in fig. 4 (a) to (C) are the liquid deposition operation (liquid deposition step), and the control device 50 performs the following control in the liquid deposition operation as described above. That is, in order to perform the liquid adhesion operation for starting adhesion of the coating liquid to the substrate 7, after the coating liquid is supplied to the coater 10 by the pump 30 and the pressure of the coating liquid in the coater 10 is increased by the supply, when the pressure decrease is detected by the pressure sensor 60, the supply of the coating liquid by the pump 30 is stopped. In the present embodiment, when the pressure sensor 60 detects a decrease in pressure after the application liquid is supplied to the applicator 10 by the pump 30 in a state where the communication between the applicator 10 and the second container 41 is shut off by the second valve 72 (that is, the second valve 72 is in a closed state), the supply of the application liquid by the pump 30 is stopped, and the second valve 72 is operated (that is, the second valve 72 is opened) to communicate the second container 41 with the applicator 10.

According to this liquid adhesion operation, when the applicator 10 is supplied with the coating liquid from the pump 30, the pressure of the coating liquid in the applicator 10 temporarily rises, whereby the coating liquid is ejected from the ejection port 11. When the coating liquid comes into contact with the substrate 7, the coating liquid in the coater 10 is further sucked out by the surface tension of the coating liquid, and the pressure in the coater 10 is thereby reduced. Therefore, when the pressure sensor 60 detects the pressure decrease, the supply of the coating liquid by the pump 30 is stopped, and the excessive coating liquid can be prevented from adhering to the substrate 7 when the liquid adhesion operation is performed. Further, by opening the second valve 72 to communicate the second container 41 with the applicator 10, the pressure of the coating liquid in the applicator 10 can be maintained at a constant value (negative pressure) after the coating liquid discharged from the discharge port 11 adheres to the substrate 7.

The liquid adhesion operation is performed as described above, and when the pressure of the coating liquid in the applicator 10 becomes negative (when the pressures of the two are equal) due to the influence of the pressure of the coating liquid in the second container 41, the second valve 72 is closed. Then, as shown in fig. 5 a, a coating operation (coating step) is performed. In this process, the movement of the applicator 10 in the horizontal direction is started by the moving unit 20 (linear actuator 23), and the supply of the coating liquid by the pump 30 is started. Then, the applicator 10 is moved in the horizontal direction while the pump 30 supplies the coating liquid.

In the present embodiment, the moving speed of the coater 10 is constant. Here, since the substrate 7 is circular, as described above (see fig. 2), the applicator 10 (the ejection port 11) has a portion where the substrate 7 is present directly below and a portion where the substrate 7 is not present directly below, and the range of each of these portions changes depending on the relative position of the substrate 7 and the applicator 10. The elongated ejection port 11 ejects the coating liquid at a portion where the substrate 7 is present as shown in fig. 2 (B), whereas the coating liquid is not ejected at a portion where the substrate 7 is not present as shown in fig. 2 (C).

Therefore, in order to apply the coating liquid to the circular substrate 7 by moving the applicator 10 at a constant speed and form a coating film having a constant film thickness on the substrate 7, the amount of the coating liquid to be discharged from the discharge port 11 differs depending on the position of the applicator 10 with respect to the substrate 7. Therefore, the following control (constant-volume discharge control) is performed: the amount of coating liquid required to form a coating film of a constant film thickness on the substrate 7 is fed out from the pump 30 instead of feeding out a constant amount of coating liquid. That is, the amount of the coating liquid sent from the pump 30 is an amount corresponding to the amount of the coating liquid (the required amount) that changes in accordance with a change in the width direction (a change in shape) of the substrate 7. The width direction of the substrate 7 is a direction that coincides with the longitudinal direction of the applicator 10 (the discharge port 11).

As described above, the amount of the coating liquid sent from the pump 30 is set in the computer program stored in the storage unit of the control device 50. That is, the computer program includes data corresponding to the relative position of the coater 10 and the substrate 7 and the discharge amount (supply amount) of the coating liquid at that position, and the control device 50 operates the pump 30 and the moving unit 20 based on the data. Thus, a predetermined amount of coating liquid can be discharged from the coater 10 without using the measurement value of the pressure sensor 60, and a constant film thickness can be formed on the substrate 7. The discharge rate according to the position is a value obtained in advance from a coating film to be formed, and varies according to the coating film.

At the start of the coating operation, the preliminary processing is executed to set the pressure of the coating liquid in the applicator 10 to a negative pressure, and the applicator 10 is replenished with the amount of the coating liquid discharged from the discharge port 11 by the pump 30, so that the pressure in the applicator 10 is maintained at a constant value while maintaining the negative pressure during the coating operation.

As described above, in the control mode (one mode), the control device 50 performs the following control when the coating operation is performed. That is, at the time of the coating operation, control is performed for supplying the coating liquid corresponding to the amount of the coating liquid to be consumed by being discharged from the discharge port 11 to the applicator 10 from the pump 30. By this control, the capillary coating can be easily controlled while maintaining the negative pressure of the coating liquid in the coater 10, and a coating film having a desired uniform thickness can be formed on the substrate 7 (coated surface 8).

Then, as shown in fig. 5B, when the applicator 10 (the ejection port 11) reaches the application end position of the substrate 7 (the edge portion of the substrate), the supply of the application liquid by the pump 30 is stopped.

When the supply is stopped, although not shown, the applicator 10 is raised by the lift actuator 24, the first valve 71 is closed, and the third valve 73 is opened. Then, the pump 30 sucks and replenishes the coating liquid in the first container 35 to prepare for the next coating. The substrate 7 coated with the coating liquid is taken off from the stage 9 and conveyed to a dryer.

As described above, in the control mode (one), control is performed in which the pump 30 supplies the coating liquid consumed by coating. In this control, the second valve 72 of the pressure control line L2 is closed, and only the pump 30 in the pump control line L1 is in a liquid supply state. The pump 30 supplies the coating liquid to the coater 10 in an amount corresponding to a preset ejection amount of the coating liquid from the coater 10. At this time, the amount of the coating liquid supplied to the coater 10 is set to: the amount of the coating liquid is smaller than the amount of the coating liquid sucked out of the coater 10 by the shearing force of the liquid beads 3 of the coating liquid generated between the substrate 7 and the coater 10 due to the capillary phenomenon and the coating operation, thereby providing the coating liquid while suppressing the ejection. As a result, although the coating liquid is supplied by the pump 30, a force to suck the coating liquid to the outside acts in the applicator 10 from the discharge port 11, and the coating liquid in the applicator 10 is maintained in a negative pressure state.

[ control mode (II) ]

The initial dispensing step of initially dispensing the coating liquid from the coater 10, the wiping step of wiping the ejection ports 11 of the coater 10, and the preparatory movement step of moving the coater 10 so that the ejection ports 11 are positioned directly above the coating start position of the substrate 7 (the edge of the substrate 7) in the control mode (the second mode) are performed in the same manner as the initial dispensing step (fig. 3 a), the wiping step (fig. 3B), and the preparatory movement step (fig. 3C) in the control mode (the first mode).

The above-described preliminary processing is performed until the preparation movement step is completed in the same manner as in the control mode (one mode).

Then, a liquid adhesion operation (liquid adhesion step) for starting adhesion of the coating liquid to the substrate 7 is started. This liquid deposition operation is similar to the liquid deposition operation (liquid deposition step) in the control mode (one of) shown in fig. 4 (a) to (C).

The description of the same manner as in the control mode (one mode) is omitted here.

When the liquid adhesion operation is completed, the liquid beads 3 formed by the coating liquid are formed between the substrate 7 and the ejection port 11 (see fig. 4C). The liquid adhering operation is performed, and the second valve 72 is opened to communicate the second container 41 with the applicator 10, so that the pressure of the coating liquid in the applicator 10 is maintained at a constant value (negative pressure) after the coating liquid discharged from the discharge port 11 is adhered to the substrate 7.

When the pressure of the coating liquid in the applicator 10 becomes negative due to the influence of the pressure of the coating liquid in the second container 41, the second valve 72 is closed in the control mode (one mode) (see fig. 5 a), but the open state of the second valve 72 is maintained in the control mode (the second mode) (see fig. 6 a). Then, a coating operation (coating step) is performed. In this step, the horizontal movement of the applicator 10 by the moving unit 20 (linear actuator 23) is started, and the pressure of the coating liquid in the second container 41 is controlled so that the pressure of the coating liquid in the applicator 10 connected to the second container 41 is maintained at a constant value (constant negative pressure value), and the coating liquid can be supplied to the applicator 10 by the pump 30. That is, while the applicator 10 is moved in the horizontal direction by the moving unit 20, the control device 50 performs pressure control by the second container 41 and the pressure regulator 42 and supply control of the supply of the coating liquid by the pump 30.

The pressure control performed during the coating operation is control for maintaining the pressure of the coating liquid in the second container 41 at a set value, thereby setting the pressure of the coating liquid in the coater 10 at a predetermined (constant) negative pressure value.

The supply control performed during the coating operation is feedback control based on the measurement value of the pressure sensor 60. That is, the control device 50 detects a change in the measurement value of the pressure sensor 60 at every moment, and when the change exceeds a threshold value (allowable value), the supply or suction of the coating liquid by the pump 30 is performed. Specifically, the operation of supplying the coating liquid is performed when the measured value by the pressure sensor 60 decreases and the amount of change thereof exceeds the threshold value, and the operation of sucking the coating liquid is performed when the measured value increases and the amount of change thereof exceeds the threshold value. In this way, the control device 50 performs an adjustment operation based on the supply or suction of the coating liquid by the pump 30, thereby further stabilizing the pressure of the coating liquid in the applicator 10.

In addition, in the control mode (second mode), the moving speed of the applicator 10 is also constant. Here, since the substrate 7 is circular, as described above (see fig. 2), the applicator 10 (the ejection port 11) has a portion where the substrate 7 is present directly below and a portion where the substrate 7 is not present directly below, and the range of each of these portions changes depending on the relative position of the substrate 7 and the applicator 10. The coating liquid is discharged from the elongated discharge port 11 at a portion where the substrate 7 is present as shown in fig. 2 (B), whereas the coating liquid is not discharged at a portion where the substrate 7 is not present as shown in fig. 2 (C).

Therefore, in order to apply the coating liquid to the circular substrate 7 by moving the coater 10 at a constant speed to form a constant film thickness on the substrate 7, the amount of the coating liquid to be discharged from the discharge port 11 varies depending on the position of the coater 10 with respect to the substrate 7. Therefore, the following control is performed: the amount of coating liquid required to form a coating film of a constant film thickness on the substrate 7 is fed out from the pump 30 instead of feeding out a constant amount of coating liquid. In the control mode (second mode), as described above, the supply or suction of the coating liquid by the pump 30 is controlled based on the measurement value of the pressure sensor 60, and the pressure in the applicator 10 is adjusted (made constant). That is, the amount of the coating liquid sent from the pump 30 is the sum of an amount corresponding to the amount of the coating liquid (the required amount) that changes in accordance with a change in the width direction (a change in shape) of the substrate 7 and an amount of the coating liquid that supplies or sucks the coating liquid by performing control in accordance with the measurement value of the pressure sensor 60.

In the control mode (one), the amount of the coating liquid sent from the pump 30 is set in a computer program stored in advance in the control device 50, but in the control mode (the second), the amount of the coating liquid sent from the pump 30 changes at every moment in accordance with the measurement value of the pressure sensor 60.

As described above, the control device 50 performs the following control during the coating operation. That is, during the coating operation, in order to maintain the negative pressure of the coating liquid in the coater 10, the pressure applying device 40 (the second container 41 and the pressure regulator 42) controls the pressure of the coating liquid in the coater 10, and based on the measurement result of the pressure sensor 60, the adjustment control including the supply and suction of the coating liquid by the pump 30 is performed.

At the start of the coating operation, the preliminary processing is executed to set the pressure of the coating liquid in the coater 10 to a negative pressure, and even when the coating operation is started, the negative pressure of the coater 10 is maintained by the pressure applying device 40, and the control by the pump 30 is performed based on the measurement result of the pressure sensor 60, so that the pressure of the coating liquid in the coater 10 is maintained at a constant value while being maintained at a negative pressure.

By this control, pressure control is performed to keep the pressure (negative pressure) in the coater 10 constant, capillary coating control is facilitated, and a coating film having a uniform thickness is formed on the substrate 7 (coated surface 8).

In the present embodiment, as shown in fig. 6B, a dummy substrate 65 is provided on the stage 9 adjacent to the edge of the substrate 7 (the edge on the coating end side) in addition to the substrate 7, and the coater 10 moves along the substrate 7 to pass the coating end position of the substrate 7 (the edge of the substrate 7) and continues to discharge the coating liquid until reaching the dummy substrate 65. When the applicator 10 (the discharge port 11) reaches a predetermined position of the dummy substrate 65, the adjustment (discharge) of the coating liquid by the pump 30 is stopped, and the second valve 72 is closed.

Further, although not shown, the applicator 10 is raised by the lift actuator 24, the first valve 71 is closed, and the third valve 73 is opened. Then, the pump 30 sucks and replenishes the coating liquid in the first container 35 to prepare for the next coating. The substrate 7 coated with the coating liquid is taken off from the stage 9 and conveyed to a dryer.

The dummy substrate 65 may be omitted and the coating operation may be ended as in the control mode (one mode), or the dummy substrate 65 may be used in the control mode (one mode).

In this control mode (the second control mode), both the first valve 71 of the pump control line L1 and the second valve 72 of the pressure control line L2 are opened and controlled. When a decrease in pressure is detected by the pressure sensor 60 provided in the applicator 10 while the coating operation is being performed, a small amount of liquid is supplied to the applicator 10 by the pump 30, and the pressure in the applicator 10 can be returned to the original set value. By feedback-controlling this operation in a short time, the pressure in the applicator 10 can be kept constant.

The amount of liquid supplied by the pump 30 may be an amount corresponding to the predicted consumption of the coating liquid, and is preferably a value adjusted by performing feedback control when a difference occurs between the set amount of liquid supplied and the actual amount of liquid consumed.

[ control modes (one) and (two) thereof ]

In the coating apparatus 5 having the above-described configuration, the control apparatus 50 may selectively employ one or both of the pump control line L1 and the pressure control line L2 according to the coating conditions. That is, the control mode (one) or the control mode (the other) is selected alternatively according to the coating conditions. Examples of the coating conditions include a film thickness formed on the substrate 7 and a coating speed (a moving speed of the coater 10).

The liquid adhesion operation (the liquid applying method at the start of application) performed in each of the control modes (first mode) and (second mode) will be further described. As shown in fig. 4 (a), a small amount of the coating liquid is discharged from the coater 10 slowly by the supply of the coating liquid from the pump 30 in a state where the second valve 72 of the pressure control line L2 is closed and the first valve 71 of the pump control line L1 is opened. At this time, the pressure in the applicator 10 changes from the negative pressure state to the positive pressure direction. When the coating liquid discharged from the coater 10 adheres to the substrate 7 (see fig. 4B), the coating liquid (beads 3) that has been in contact with the substrate 7 by the coater 10 tends to adhere and spread due to surface tension, and a force is generated to draw the coating liquid from the coater 10. Due to this force, the pressure inside the applicator 10 changes to the negative pressure direction. When such a pressure change in the coater unit 10 is detected by the pressure sensor 60, the pressure control line L2 and the pump control line L1 are switched as follows.

That is, the pump 30 is stopped and the second valve 72 of the pressure control line L2 is opened in response to a change in pressure in the applicator 10 (see fig. 4C). Thereby, the pressure in the applicator 10 becomes a pressure set in advance through the pressure control line L2 (second container 41). At this time, the following control is performed: the time from the start of the pressure change to the stop of the supply of the coating liquid by the pump 30 and the time from the start of the pressure change to the opening of the second valve 72 are set to predetermined times by a timer, so that the amount of the coating liquid discharged from the applicator 10 at the start of the coating can be controlled.

After the second valve 72 is opened, when the pump 30 controls the thickness of the coating film (first control mode), the second valve 72 is closed again, and the pump 30 supplies the coating liquid. When the coating film thickness is controlled by pressure control (control mode (second)), the second valve 72 is kept open, and pressure constant control is performed according to the set pressure.

Further, when the application of the coating liquid is performed at the application start portion of the substrate 7, the supply of the coating liquid is performed by the pump 30, thereby suppressing the amount of the coating liquid to be discharged to the outside of the applicator 10 due to the capillary phenomenon to a necessary minimum. Further, by detecting the timing of applying the coating liquid based on the pressure change of the applicator 10, even if a small amount of the coating liquid is discharged, the coating liquid can be reliably applied, and a stable film thickness at the application start portion can be obtained.

As described above, in the two control modes, the control device 50 performs control such that the coating liquid is supplied from the pump 30 to the applicator 10 while maintaining the negative pressure of the coating liquid in the applicator 10 during the coating operation. According to this configuration, the amount of the coating liquid supplied to the coater 10 can be controlled to a predetermined amount by the pump 30 during the coating operation, and the amount of the coating liquid to be discharged from the discharge port 11 to the outside of the coater 10 due to the surface tension of the coating liquid discharged from the coater 10 to the substrate 7 and the capillary phenomenon can be suppressed. Therefore, capillary coating can be performed, and the coating liquid is discharged downward from the discharge port 11, whereby a coating film having a desired thickness (uniform thickness) can be formed on the substrate 7 (coated surface 8).

By applying the coating method (capillary coating) by the coating apparatus 5 to a product manufacturing method, a high-quality product having a coating film with a uniform thickness formed over the entire surface can be stably manufactured.

[ conditions of application ]

As the coating liquid that can be applied to the above-described coating apparatus 5, a newtonian type having a viscosity of 1 to 100000mPa · S is preferable from the viewpoint of coatability, and a coating liquid having thixotropy can also be applied. Specifically, examples of applicable coating liquids include a black matrix for a color filter, a coating liquid for forming RGB color pixels, a resist liquid, an overcoat material, a pillar-forming material, and the like, a coating liquid for an adhesive layer for a semiconductor, a coating liquid for planarization, a coating liquid for a protective film, a resist liquid, a coating liquid for a colored layer, a coating liquid for a fluorescent light-emitting layer, a positive resist for a TFT, and the like.

As the substrate (member to be coated) 7, a metal plate such as aluminum, a ceramic plate, a film, or the like can be used in addition to a silicon wafer or glass. The substrate (member to be coated) 7 may have a rectangular shape or a non-rectangular shape such as a circular shape. Further, a plurality of non-rectangular substrates may be arranged in parallel along the longitudinal direction of the coater 10, and the substrates 7 may be coated simultaneously. Further, as the coating conditions to be used, the coating speed is 0.1 to 100 mm/sec, more preferably 0.5 to 20 mm/sec, the gap (slit gap) between the discharge port 11 of the coater 10 and the coated surface 8 of the substrate 7 is 50 to 1000 μm, more preferably 100 to 500 μm, and the coating thickness is 0.5 to 100 μm, more preferably 1 to 50 μm in a wet state.

[ example 1]

An example in the case of adopting the control mode (one of them) will be described.

A circular silicon wafer having a diameter of 100mm and a thickness of 0.53mm was coated with polyimide by a coating apparatus 5 shown in FIG. 1. The polyimide had a viscosity of 4400 mPas and a solid content of 19%. As the applicator 10, an applicator having an ejection port 11 with a length in the application width direction (longitudinal direction, Y direction) of 150mm and an ejection port 11 with a gap (length in the X direction) of 0.4mm was used. In order to measure the pressure of the coating liquid in the reservoir 13 of the applicator 10, a pressure sensor 60 is provided.

Then, by controlling the discharge rate by the pump 30, the discharge rate varied according to the application width was determined so that the wet film thickness became 40 μm, and the application was performed under the conditions that the pressure in the applicator 10 at the start of the application was-20 Pa (gauge pressure) and the application speed was 0.5 mm/sec.

The coated substrate 7 was dried for 10 minutes using a hot plate at 150 ℃. As a result of observing the coating state after drying, it was found that a coating film having a thickness of 8 μm was formed over the entire surface region of φ 100, and it was good that the variation in film thickness was. + -. 3% or less in a range of 96mm or less in diameter except for a range of 2mm in the outer peripheral portion of the coating.

[ example 2]

Another embodiment in the case where the control mode (second) is adopted will be described.

A circular silicon wafer having a diameter of 100mm and a thickness of 0.53mm was coated with a color resist by a coating apparatus 5 shown in FIG. 1. The color resist had a viscosity of 4 mPas and a solid content concentration of 15%. As the applicator 10, an applicator having an ejection port 11 with a length in the application width direction (longitudinal direction, Y direction) of 150mm and an ejection port 11 with a gap (length in the X direction) of 0.2mm was used. In order to measure the pressure of the coating liquid in the reservoir 13 of the applicator 10, a pressure sensor 60 is provided.

Then, as the discharge amount control based on the constant pressure control, the pump 30 corrects the pressure fluctuation in the applicator 10.

Under the conditions that the pressure in the applicator 10 at the start of application is-180 Pa (gauge pressure) and the application speed is 2 mm/sec, the application operation is performed while feedback-controlling the pump 30 so that the fluctuation of the discharge pressure is within 5Pa as a threshold value.

The coated substrate 7 was vacuum-dried for 60 seconds to reach 65Pa for 25 seconds, and then further dried for 10 minutes by a hot plate at 120 ℃.

As a result of observing the coating state after drying, it was found that a coating film having a thickness of 800nm was formed over the entire surface region of φ 100, and the variation in film thickness was favorable to be. + -. 3% or less in a range of 96mm or less in diameter within a range of 2mm except the outer peripheral portion of the coating.

When the direction in which the coating liquid is discharged from the applicator 10 (discharge port 11) is directed downward (when capillary coating is performed downward) as in the present embodiment, the significance of making the coating liquid in the applicator 10 negative pressure is described in the following (1) and (2).

(1) The coating liquid in the applicator 10 is allowed to freely flow out of the discharge port 11 without being self-weight.

(2) In order to adjust the film thickness formed on the substrate 7.

The coating device 5 may be configured such that the discharge direction of the coating liquid is directed upward (including obliquely upward). In this case (in the case of capillary coating performed upward), although not shown (described with reference to fig. 1), in the same state as in the case of the discharge port 11 being downward, a bead of the coating liquid is formed between the discharge port 11 and the substrate 7 above the discharge port, and the coating liquid in the vicinity of the discharge port 11 (the slit-shaped flow path 12) becomes a negative pressure. In this operation, the pressure value applied to the container 41 by the pressure regulator 42 may be a pressure value calculated from the fact that the coating liquid in the vicinity of the discharge port 11 has a predetermined negative pressure, and may not be a negative pressure. Then, the coating operation is performed in this state. That is, in the coating operation, the control device 50 performs control such that the coating liquid in the vicinity of the discharge port 11 in the applicator 10 is brought into a negative pressure and the coating liquid is supplied from the pump 30 to the applicator 10. Specifically, control is performed to supply the coating liquid corresponding to the amount of the coating liquid to be ejected from the ejection port 11 from the pump 30 to the applicator 10. That is, the coating operation is performed according to the control mode (one mode). The control device 50 also has the following functions: in order to maintain the negative pressure of the coating liquid in the vicinity of the ejection port 11 in the applicator 10, the pressure of the coating liquid in the applicator 10 is controlled by the pressure applying device 40, and the adjustment control of the coating liquid by the pump 30 is performed based on the measurement result of the pressure sensor 60. That is, the coating operation according to the control mode (the second mode) may be performed. In the case of capillary coating in the upward direction, the meaning of making the coating liquid in the vicinity of the discharge port 11 in the applicator 10 a negative pressure is (2) described above.

[ accompanying notes ]

The embodiments disclosed herein are illustrative in all respects, not restrictive. The scope of the present invention is not limited to the above embodiments, and includes all modifications within a range equivalent to the structure described in the claims.

In the above embodiment, the member to be coated is the substrate 7 in a single piece shape, but may be a continuous member instead of a single piece shape.

Description of the reference symbols

5: a coating device; 7: a substrate (coated member); 8: a coated surface; 10: an applicator; 11: an ejection port; 12: a slit-shaped flow path; 13: an accumulation section; 20: a mobile unit; 30: a pump; 35: a first container; 40: a pressure applying device; 41: a second container; 42: a pressure regulator; 50: a control device; 60: a pressure sensor; 71: a first valve; 72: a second valve; 73: a third valve; 81: piping; 82: piping; 83: piping.

Claims

1. A coating apparatus, comprising:

an applicator having an accumulation portion for accumulating a coating liquid, an ejection port for ejecting the coating liquid, and a slit-shaped flow path connecting the accumulation portion and the ejection port, the applicator ejecting the coating liquid from the ejection port 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 connected to the applicator through a pipe connected to the applicator, the pump supplying the coating liquid to the reservoir; and

a control device that performs control for maintaining the coating liquid in the accumulation portion at a negative pressure and supplying the coating liquid from the pump to the applicator, when performing a coating operation of discharging the coating liquid from the discharge port to the member to be coated while performing the relative movement,

the coating device further has:

a container that accumulates a coating liquid and is connected to the applicator; and

a pressure regulator for regulating the pressure of the coating liquid in the container to a negative pressure to thereby make the pressure of the coating liquid in the accumulation section a negative pressure,

the pressure regulator adjusts the pressure of the coating liquid in the container to make the pressure of the coating liquid in the reservoir negative by the influence of the pressure in order to form droplets of the coating liquid between the member to be coated and the ejection port,

the control device performs control for maintaining a negative pressure of the coating liquid in the accumulation portion by the influence of the pressure and supplying the coating liquid from the pump to the applicator when performing an application operation of ejecting the coating liquid from the ejection port to the member to be coated while performing the relative movement in a state where the droplet is formed.

2. The coating apparatus according to claim 1,

when the coating operation is performed, the control device performs the following control: supplying a coating liquid corresponding to an amount of the coating liquid to be ejected from the ejection port from the pump to the applicator.

3. The coating apparatus according to claim 1 or 2,

the container and the pressure regulator constitute a pressure applying device for applying pressure to the coating liquid in the coater,

the coating apparatus further has a pressure sensor that measures a pressure of the coating liquid in the coater,

the control device performs pressure control of the coating liquid in the coater by the pressure imparting device in order to maintain the coating liquid in the coater at a negative pressure, and performs adjustment control of the coating liquid by the pump according to a measurement result of the pressure sensor.

4. The coating apparatus according to claim 1 or 2,

after the coating liquid is supplied to the coater by the pump in order to perform a liquid adhesion action for starting adhesion of the coating liquid to the member to be coated and the pressure of the coating liquid in the coater is increased by the supply, the control device stops the supply of the coating liquid by the pump when detecting the decrease in the pressure.

5. The coating apparatus according to claim 4,

the applicator further having a valve capable of connecting and disconnecting the applicator to the container,

the control device stops the supply of the coating liquid by the pump and operates the valve to communicate the container with the applicator when the pressure decrease is detected after the coating liquid is supplied to the applicator by the pump in a state where the communication of the applicator with the container is shut off by the valve.

6. A coating method for performing capillary coating by discharging a coating liquid from a discharge port of an applicator having a reservoir portion for accumulating the coating liquid, the discharge port for discharging the coating liquid, and a slit-shaped flow path connecting the reservoir portion and the discharge port,

the coating liquid can be supplied to the accumulation section from a pump connected to the applicator through a pipe connected to the applicator,

the coating method performs the following coating operations: discharging the coating liquid from the discharge port toward the member to be coated while relatively moving the applicator and the member to be coated in a direction parallel to the surface to be coated of the member to be coated,

maintaining the coating liquid in the accumulation section at a negative pressure and supplying the coating liquid from the pump to the coater during the coating operation,

connecting a container in which the coating liquid is accumulated to the applicator, and being capable of adjusting the pressure of the coating liquid accumulated in the container to a negative pressure by a pressure adjuster so as to make the pressure of the coating liquid in the accumulation portion be a negative pressure, wherein:

in a state where the droplet is formed, a negative pressure of the coating liquid of the accumulation section generated by the influence of the pressure is maintained and the coating liquid is supplied from the pump to the applicator while the coating operation is performed.

7. The coating method according to claim 6,

in the coating operation, a coating liquid corresponding to an amount of the coating liquid to be ejected from the ejection port is supplied from the pump to the applicator.

8. The coating method according to claim 6 or 7,

the pressure of the coating liquid in the applicator is measured by a pressure sensor,

the pressure control of the coating liquid in the coater is performed in order to maintain the coating liquid in the coater at a negative pressure, and the adjustment control of the coating liquid by the pump is performed in accordance with the measurement result of the pressure sensor.

9. The coating method according to claim 6 or 7,

after the application liquid is supplied to the applicator by the pump in order to perform a liquid adhesion action of starting adhesion of the application liquid to the member to be coated and the pressure of the application liquid in the applicator is increased by the supply, when the pressure decrease is detected, the supply of the application liquid by the pump is stopped.

10. The coating method according to claim 9,

a valve is provided in the applicator, the valve being connected to the container in which the coating liquid is stored by a pipe and capable of connecting and disconnecting the applicator to and from the container,

when the pressure decrease is detected after the application liquid is supplied to the applicator by the pump in a state where the communication between the applicator and the container is cut off by the valve, the supply of the application liquid by the pump is stopped, and the valve is operated to communicate the container and the applicator.