JPH1187224A - Coating device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reproducibility and stability of coating performance, while increasing the design freedom by constantly filling up a coating solution vessel by supplementing the coating solution drawn up from the vessel for the coating work from an external tank. SOLUTION: An external tank 5 and a fixed quantity discharging and sucking up unit 8 are connected to a coating solution vessel 11. In the coating starting time, first, a fixed quantity of coating solution is fed to the vessel 11 from the unit 8, and then coating solution is fed to the vessel 11 from an atmospheric opened external tank 5 so as to initially form a reservoir part. Moreover, the coating solution in the vessel 11 is coated on a substrate S by coating a work, the coating solution equivalent to the consumed amount is supplied to the vessel 11 from the external tank 5 for constantly filling up the vessel 11 with the coating solution at all times. Furthermore, when a nozzle 1 reaches a final coating position, the quantity discharging and sucking up unit 8 sucks up the fixed quantity of the coating solution from the coating solution vessel 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for manufacturing a liquid crystal display device (LCD), a plasma display device (PDP), a semiconductor device, various electronic parts, and the like. Coating by pumping various coating liquids by capillary action to form a photoresist film, color filter material, flattening material, interlayer insulating film, insulating film, conductive film, etc. on the coating surface of various substrates The present invention relates to an apparatus and a coating method.

[0002]

2. Description of the Related Art Conventionally, in a manufacturing process of a liquid crystal display device, a semiconductor device, or the like, a substrate is rotated while being kept horizontal, a coating liquid is supplied to a central portion thereof, and a centrifugal force is applied to the coating liquid. A spin coating method for uniformly applying a coating liquid from a central portion to an outer peripheral portion on a substrate surface is widely used.

[0003] However, in the spin coating method, the coating solution is spun outward by centrifugal force in combination with the tendency of the substrate to become larger and squarer, which is wasteful in terms of effective use of the used coating solution. And the use efficiency of the coating liquid was poor. Also,
By rotating the rectangular substrate in a horizontal posture, the size of the apparatus is increased as the size of the substrate is increased, and the installation space has to be increased. Furthermore, when a rectangular substrate is rotated at a high speed, turbulence of the air flow easily occurs on the substrate surface. It has been difficult to ensure coating quality such as unevenness and uniformity of coating film thickness.

In order to solve the above-mentioned problems of the spin coating method, that is, a reduction in the use efficiency of the coating liquid, an increase in installation space, and an uneven coating film thickness, the capillary surface is used to solve the problem. An apparatus and a method for applying a coating liquid have been proposed in, for example, Japanese Patent Application Laid-Open No. H8-24740.

FIG. 15 is a front view showing a schematic configuration of the coating apparatus described in the above publication, and FIG. 16 is a cross-sectional view taken along line AA in the coating apparatus of FIG. 15 and 16, the coating apparatus includes a stage 101 for holding a substrate 100 in a vertical (vertical) direction and a stage 101 for holding the substrate 100.
A nozzle 103 having a coating liquid tank for supplying the coating liquid 102 to the surface to be coated with the nozzle 103,
Moving means (not shown) for linearly moving downward along 0
It is composed of The nozzle 103 has a cylindrical shape having both ends closed and extending in the width direction of the substrate 100. The nozzle 103 has a slit-shaped coating penetrating from the inside of the tank to the outside on the front wall portion 104 facing the coated surface of the substrate 100. Liquid outflow channel 10
5 are formed in the width direction. Further, a front end surface 106 of the front wall portion 104 facing the coated surface of the substrate 100 is disposed so as to be in non-contact with and close to the coated surface of the substrate 100. Located below the outlet and above the opposite inlet,
The upper end 106b is formed between the surface to be coated of the substrate 100 and the front end surface 1
06 when the gap 107 extends infinitely upward and the coating liquid flowing into the gap 107 through the coating liquid outflow path 105 at least rises by capillary action or the like. It is located between the outlet of the coating liquid outflow path 105.

With the above configuration, the coating liquid 102 is injected into the coating liquid tank to a height between the entrance of the coating liquid outflow passage 105 and the lower end 106a of the front end surface 106, and the coating liquid tank is opened to the atmosphere. The coating liquid 102 supplied into the tank flows out of the tank through the coating liquid outflow path 105 by at least capillary action, and the coating surface and the front end surface 106 of the substrate 100 held in the vertical posture by the stage 101 Flows into the gap 107 between them.

The coating liquid flowing into the gap 107 descends to the lower end 106a of the front end face 106 due to a capillary phenomenon or the like.
06 does not flow down from the lower end 106a. The upward flow of the coating liquid flowing into the gap 107 rises in the gap 107 to the upper end 106b of the front end face 106 due to capillary action or the like.
Is not regulated any more. In this way, a band-like liquid pool of the coating liquid extending in the width direction of the substrate 100 is formed in the gap 107 between the coating surface of the substrate 100 and the front end surface 106.

Further, in the state where the liquid pool of the coating liquid is formed, the gap 107 between the coated surface of the substrate 100 and the front end surface 106 is maintained, and the longitudinal direction of the substrate 100 (the width direction of the substrate 100) is maintained. Nozzle 103 in the vertical direction a)
When the substrate and the substrate 100 are relatively moved linearly, the application liquid is applied to the application surface of the substrate 100. At this time,
The coating liquid in the liquid pool in the gap 107 between the coating surface of the substrate 100 and the front end surface 106 is consumed as the coating liquid is applied to the coating surface of the substrate 100.
Due to the atmospheric pressure, capillary action, and the like applied to the coating liquid in the coating liquid tank 03, a coating liquid substantially equivalent to the consumption amount is supplied from the coating liquid tank to the gap 107 through the coating liquid outflow path 105. Therefore, the amount of the coating liquid in the gap 107 at the time of coating is always kept substantially constant.
The coating liquid is continuously applied to the substrate.

[0009]

However, in the coating apparatus configured as described above, the coating liquid tank of the nozzle 103 is open to the atmosphere, and a gas phase exists in the coating liquid tank. Therefore, problems tend to occur such that the coating liquid gels and contaminates the inside of the coating liquid tank, or the gel-like substance blocks the coating liquid outflow passage 105 and the coating liquid is not appropriately supplied to the substrate 100 side.

Further, in order to solve the above-mentioned problems, it is necessary to frequently perform a series of detachable cleaning processes of removing the nozzle from the coating device, performing the cleaning process, and returning the nozzle to its original position. Coating performance lacked reproducibility and stability. This is because the coating performance is closely related to the nozzle assembly accuracy (horizontal accuracy, spacing accuracy and parallelism with the substrate, etc.), and the nozzle assembly state before and after the nozzle attachment / detachment cleaning process is small. However, if they are different, the coating performance will be greatly different. Therefore, the conventional coating apparatus which needs to frequently perform the nozzle attaching / detaching / cleaning process is necessarily inferior in the reproducibility and stabilization of the coating performance.

Further, factors closely related to the coating performance include, in addition to the assembling accuracy, the nozzle shape accuracy. This means that it is necessary to finish the nozzle with high precision in order to ensure the reproducibility and stability of the coating performance. For this reason, the nozzle is conventionally formed of metal. For this reason, the following problem has arisen.

That is, the liquid level in the coating liquid tank (the “liquid level” as used herein means the liquid level of the nozzle 103 with respect to the outlet on the front end face 106 side of the coating liquid outflow passage 105 from the coating liquid tank 105). The relative height means the same hereinafter.) Is the substrate 1
Is closely related to the thickness of the coating film formed at 00,
For example, when the liquid level height is reduced, the force due to the capillary phenomenon for the coating liquid to rise in the coating liquid outflow path 105 is relatively reduced, and it becomes difficult to supply the coating liquid to the gap 107. The thickness decreases. Therefore, in order to stabilize the thickness of the coating film formed on the substrate 100, it is important to appropriately check the liquid level and replenish the coating liquid before the liquid level is significantly reduced. Becomes However, in the conventional coating apparatus, the nozzle is formed of metal as described above, so that the level of the coating liquid stored in the coating liquid tank can be visually checked from outside the nozzle. However, it has been difficult to construct the nozzle itself, and an effective and simple nozzle configuration for stabilizing the film thickness cannot be adopted.

In this type of coating apparatus, when the coating is started, the coating liquid is forcibly supplied into the gap 107 between the substrate 100 and the nozzle 103 in order to initially form a liquid pool in the gap 107. Must. In the above-mentioned publication, the coating liquid rising to the outlet of the coating liquid outflow passage 105 by capillary action is subjected to pressure means (not shown) for increasing the pressure in the nozzle 103 (coating liquid tank) before coating. The surface to be coated of the substrate 100 and the front end surface 1 of the nozzle 103
It has been proposed that a certain amount of liquid pool be formed by supplying the liquid into the gap 107 between the liquid crystal layer and the liquid crystal layer 06.

However, for example, when a photoresist solution is to be applied at a thickness normally used (for example, 1.5 μm after drying), the gap 107 is usually 0.3 μm.
The gap size is as large as 0.7 mm to 0.7 mm, and a relatively large amount of the coating solution is required to supply the coating solution into the gap 107 only by the pressurizing means (not shown). If the supply speed and the supply amount are not precisely and precisely controlled in pressure, there is a problem that the amount of liquid in the liquid pool is too large or the liquid pool flows down in some cases. Or, conversely, there is a problem that the amount of liquid in the liquid pool in the gap 107 is too small, resulting in poor coating.

Further, the coating apparatus (FIG. 15 and FIG. 16) configured as described above has a problem that a liquid pool is formed at the lower end of the substrate 100 after coating and the film becomes thick. As described above, when the film is thickened at the coating end portion of the substrate, a film residue may be left at the time of development. In order to solve this problem, Japanese Patent Application Laid-Open Nos. 8-155365 and 8-141475 propose various means for collecting a coating liquid. However, in these proposals, a component for adhering an excess coating solution to a separately provided component or for scraping off the excess coating solution is provided. Each time is performed, it is necessary to wash excess coating liquid attached to these components. As a result, there is a problem that the number of work steps is increased by the provision of such a cleaning step, and the throughput is reduced, and the recovered coating liquid is wasted.

Further, when the coating liquid tank which is open to the atmosphere is provided in the nozzle as described above, there is a possibility that the coating liquid in the coating liquid tank flows out when the nozzle is moved downward. For this reason, it is necessary to maintain a posture in which the coating liquid does not spill from the nozzle, and the posture of the nozzle is greatly restricted. Therefore, it is necessary to design the coating apparatus in consideration of the nozzle attitude restriction, and the degree of freedom in designing is low.

The present invention solves the above-mentioned conventional problems, and it is an object of the present invention to provide a coating apparatus and a coating method which have a high degree of freedom in design and have excellent reproducibility and stability of coating performance. The purpose of.

It is a second object of the present invention to provide a coating apparatus capable of easily visually checking the level of a coating liquid in a coating liquid tank.

Further, the present invention provides a method for supplying an appropriate amount of a coating liquid to a gap between a substrate and a nozzle means at the start of coating of the coating liquid to prevent dripping or poor coating and to apply the coating liquid to the substrate with excellent coating performance. A third object is to provide a coating apparatus and a coating method capable of performing coating.

Further, the present invention provides a coating apparatus and a coating method which can apply a coating liquid to a substrate with a high throughput and an appropriate film thickness by collecting excess coating liquid without waste at the end of coating. This is the fourth object.

[0021]

According to the first aspect of the present invention, there is provided a substrate holding means for holding a substrate in a vertical or inclined posture, and a coating liquid for temporarily storing a coating liquid. A nozzle means having a tank and capable of supplying the coating liquid in the coating liquid tank toward the surface to be coated, and storing the coating liquid in an open state to the atmosphere and communicating with the coating liquid tank An external tank configured so that the coating liquid can be replenished to the coating liquid tank, and the nozzle means close to the substrate held by the substrate holding means, along the surface to be coated of the substrate. A moving means for relatively moving the nozzle means, and while the moving means relatively moves the nozzle and the substrate in a state of being close to each other, the liquid is pumped from the coating liquid tank by capillary action. The coating solution Together is applied to the coated surface, it is configured so as to fill all the time the coating solution tank to replenish only from the external tank coating liquid amount pumped from the coating liquid tank with the coating liquid by the coating process.

According to the present invention, a part of the coating liquid in the coating liquid tank is pumped up and applied to the surface to be coated of the substrate, and at the same time, the coating liquid corresponding to the amount of the pumped up coating liquid is applied from the external tank. The liquid tank is replenished and the coating liquid tank is always filled with the coating liquid. Therefore, on the nozzle means side, there is no gas phase in the coating liquid tank, so that gelation of the coating liquid in the coating liquid tank is prevented, and contamination in the coating liquid tank is prevented. On the other hand, in the external tank that is open to the atmosphere, the coating liquid gels, but since the external tank is not directly related to the coating performance, the external tank can be appropriately cleaned as necessary, and the cleaning property is considered. Above can design an external tank. Further, even if the nozzle means is oriented in an arbitrary direction, the application liquid does not flow out of the nozzle means, and each part of the coating apparatus can be designed without considering the nozzle attitude.

According to a second aspect of the present invention, in order to achieve the second object, at least a part of the external tank is made of a transparent or translucent material, and the level of the coating liquid stored in the external tank is adjusted. An area whose height can be visually recognized is formed in the external tank.

According to the present invention, the area in which the liquid level of the coating liquid can be visually recognized is formed in the external tank, and the liquid level of the coating liquid in the external tank can be visually confirmed through the visible area. It has become.

According to a third aspect of the present invention, there is further provided a liquid level detecting means provided in the viewable area and detecting the liquid level of the coating liquid stored in the external tank in a non-contact manner.

According to the present invention, the liquid level detecting means is provided in the viewable area, and automatically detects the liquid level.

The invention according to claim 4 further comprises a first liquid flow control means provided between the coating liquid tank and the external tank and capable of controlling the flow of the coating liquid between them.

According to the present invention, the first liquid flow control means controls the flow of the coating liquid between the coating liquid tank and the external tank. In particular, when the flow of the coating liquid between the coating liquid tank and the external tank is prohibited, the coating liquid does not flow out of the nozzle means even if the nozzle posture is, for example, downward.

According to a fifth aspect of the present invention, in order to achieve the third object, the nozzle means is connected to the coating liquid tank,
A fixed-quantity discharge unit that performs a process of discharging a fixed amount of the coating liquid to the coating liquid tank is provided between the coating liquid tank and the fixed-quantity discharge unit, and a flow of the coating liquid between these can be controlled. And a second liquid flow control means.

According to the present invention, in a state where the supply of the coating liquid from the external tank to the coating liquid tank is prohibited by the first liquid flow control means, a constant amount of the coating liquid is supplied from the constant discharge means through the second liquid flow control means. The liquid is supplied to the application liquid tank to form a minute liquid reservoir between the nozzle means and the surface to be applied.

According to a sixth aspect of the present invention, in order to attain the fourth object, the nozzle means is connected to the coating liquid tank,
A fixed amount suction unit that performs a suction process of a fixed amount of the coating solution from the coating solution tank, and is provided between the coating solution tank and the fixed amount suction unit, and the flow of the coating solution between these can be controlled. And third liquid flow control means.

In the present invention, in a state where the inflow of the coating liquid from the coating liquid tank to the external tank is prohibited by the first liquid flow control means, a constant amount of the coating liquid is supplied from the coating liquid tank to the third liquid flow by the quantitative suction means. It is sucked and collected via the control means.

According to a seventh aspect of the present invention, in order to achieve the third and fourth objects, the nozzle means is communicated with the coating liquid tank to discharge a predetermined amount of the coating liquid into the coating liquid tank. A fixed-quantity discharge suction unit capable of selectively performing a suction process of a fixed amount of the coating liquid from the coating liquid tank; and a fixed-discharge suction unit provided between the coating liquid tank and the fixed-quantity discharge suction unit. And a second liquid flow control means capable of controlling the flow of the coating liquid in the step (a).

According to the present invention, in a state in which the supply of the coating liquid from the external tank to the coating liquid tank is prohibited by the first liquid flow control means, a constant amount of the coating liquid is supplied from the constant discharge and suction means to the second liquid flow control means. The liquid is supplied to the coating liquid tank via the nozzle, and a minute liquid pool is formed between the nozzle means and the surface to be coated. Also, the first
In a state where the flow of the coating liquid from the coating liquid tank to the external tank is prohibited by the liquid flow control means, a fixed amount of the coating liquid is sucked from the coating liquid tank through the second liquid flow control means by the constant discharge suction means. Collected.

The invention according to claim 8 is configured so that the discharge amount of the coating liquid to the coating liquid tank can be changed every discharge processing.

In the present invention, the discharge amount of the coating liquid to the coating liquid tank is controlled in accordance with the content of the discharge processing, so that an appropriate trace liquid reservoir is always formed.

According to a ninth aspect of the present invention, the suction amount of the coating liquid from the coating liquid tank can be changed every suction processing.

According to the present invention, the suction amount of the coating liquid from the coating liquid tank is controlled in accordance with the contents of the suction processing, and the film thickness at the final coating position is optimized.

According to a tenth aspect of the present invention, the moving means has a nozzle rotating mechanism for changing the direction of the nozzle means by rotating the nozzle means around a predetermined center of rotation.

In the present invention, the direction of the nozzle means is changed by the nozzle rotating mechanism to adjust the nozzle attitude.

According to an eleventh aspect of the present invention, there is provided a coating liquid provided inside the nozzle means in a state where the nozzle means is relatively moved closely along the coating surface of the substrate held in a vertical or inclined posture. A coating method in which a coating liquid stored in a tank is pumped up by capillary action and applied to the surface to be coated. In order to achieve the first object, the coating liquid is drawn up from the coating liquid tank by the coating treatment. The coating liquid is replenished by an amount corresponding to the amount of the coating liquid from an external tank provided independently of the nozzle means, and the coating liquid tank is always filled with the coating liquid.

According to the present invention, a part of the coating liquid in the coating liquid tank is pumped up and applied to the surface to be coated of the substrate, and at the same time, the coating liquid corresponding to the amount of the pumped up coating liquid is applied from the external tank. The liquid tank is replenished and the coating liquid tank is always filled with the coating liquid. Therefore, on the nozzle means side, there is no gas phase in the coating liquid tank, so that gelation of the coating liquid in the coating liquid tank is prevented, and contamination in the coating liquid tank is prevented. On the other hand, in the external tank that is open to the atmosphere, the coating liquid gels, but since the external tank is not directly related to the coating performance, the external tank can be appropriately cleaned as necessary, and the cleaning property is considered. Above can design an external tank. Further, even if the nozzle means is oriented in any direction, the outflow of the coating liquid from the nozzle means is prevented.

According to the twelfth aspect, the flow of the coating liquid between the coating liquid tank and the external tank is prohibited as required.

According to the present invention, when the flow of the coating liquid between the coating liquid tank and the external tank is prohibited, the coating liquid does not flow out of the nozzle means even if the nozzle posture is downward, for example.

According to a thirteenth aspect of the present invention, in order to achieve the third object, the flow of the coating liquid between the coating liquid tank and the external tank is prohibited when the coating liquid is applied to the substrate. At the same time, a small amount of liquid reservoir is formed between the nozzle means and the surface to be coated by discharging a constant amount of the coating liquid into the coating liquid tank.

According to the present invention, in a state in which the supply of the coating liquid from the external tank to the coating liquid tank is prohibited, a fixed amount of the coating liquid is discharged from the constant discharge means to the coating liquid tank via the second liquid flow control means. Thus, a minute liquid pool is formed between the nozzle means and the surface to be coated.

According to a fourteenth aspect of the present invention, every time the coating liquid is discharged to the coating liquid tank, the discharge amount of the coating liquid to the coating liquid tank is changed according to the discharging processing.

According to the present invention, the discharge amount of the coating liquid to the coating liquid tank is controlled in accordance with the content of the discharge processing, so that an appropriate trace liquid reservoir is always formed.

According to a fifteenth aspect of the present invention, in order to attain the fourth object, when the nozzle means is located at a final coating position on the surface to be coated, the coating is performed between the coating liquid tank and the external tank. A fixed amount of the coating liquid is sucked from the coating liquid tank while the flow of the liquid is prohibited and the nozzle means is brought close to the surface to be coated.

According to the present invention, in a state in which the flow of the coating liquid from the coating liquid tank to the external tank is prohibited, a constant amount of the coating liquid is sucked from the coating liquid tank through the third liquid flow control means by the constant amount suction means. Collected.

According to a sixteenth aspect of the present invention, the suction amount of the coating liquid from the coating liquid tank is changed in accordance with the suction processing each time the coating liquid suction processing from the coating liquid tank is performed.

In the present invention, the suction amount of the coating liquid from the coating liquid tank is controlled according to the contents of the suction processing, and the film thickness at the final coating position is optimized.

[0053]

FIG. 1 is a perspective view showing one embodiment of a coating apparatus according to the present invention. This coating apparatus utilizes a capillary phenomenon while moving the nozzle 1 functioning as a nozzle means in proximity to the substrate S held in a vertical or inclined posture along the surface to be coated of the substrate S. The coating liquid is applied to the surface of the substrate S to be coated.

In this coating apparatus, a suction stage 3 is arranged at the center of the front side of a pedestal 2 which is formed in a wall shape and stands to hold the substrate S by suction. In order to cope with a plurality of substrate sizes different from each other, the suction stage 3 is provided with an elongated concave portion 31 at an appropriate position corresponding to the outer peripheral portion of each substrate S having different substrate sizes, and through each concave portion 31. A suction cup (not shown) functioning as a suction member capable of suction is provided so as to be able to move back and forth. For this reason, when the size of the substrate to be processed is determined, after sucking the rear surface (the surface not subjected to the coating process) of the substrate S with the suction cup in the protruding state, the suction cup is drawn into the predetermined position in the recess 31 and stored. Thus, the substrate S is suction-held on the suction stage 3 with the surface to be coated facing outward.

In this embodiment, the suction cup as the suction member is configured so as not to hold the central portion of the substrate S, but the reason for this configuration is that the central portion of the substrate S is an important circuit or the like. This is to prevent the application from becoming uneven due to the temperature dropping or rising due to the vacuum suction and release by the suction cup. Accordingly, in order to suck only the outer peripheral portion of the substrate S,
It is desirable to finish in the shape of an elongated suction cup similar to the elongated recess 31.

The holding state of the substrate S by the suction stage 3 may be in a vertical (vertical) direction or in an inclined posture. For example, the substrate S is located above the suction stage 3. It may be slightly inclined as shown.
That is, in this embodiment, the suction stage 3 is
As a substrate holding means for holding the substrate in a vertical or inclined posture.

Further, here, the suction stage 3 is employed as the substrate holding means, but the method of holding the substrate S is not limited to this, and the upper, lower, left and right sides of the substrate S are hooked by nail-like members. Needless to say, a configuration for holding the information may be used.

The nozzle 1 is arranged opposite to the suction stage 3 configured as described above (FIG. 1). As shown in FIG. 2, the nozzle 1 has a coating liquid tank 11 for storing the coating liquid, and the coating liquid in the coating liquid tank 11 is supplied to the nozzle port 1.
It is configured to be able to be supplied from 2 to the substrate S side (the left-hand side in the figure) held by the suction stage (substrate holding means) 3. That is, the nozzle 1 is provided with a nozzle body 13, and an elongated cylindrical coating solution tank 11 is provided at the inner bottom of the nozzle body 13 in the width direction of the substrate S (a direction perpendicular to the paper surface of FIG. 1). Have been. In addition, the nozzle body 13 has a coating liquid tank 11 on a front wall 15 facing the surface to be coated of the substrate S.
A slit 16 is formed in the width direction, which functions as a coating liquid outflow passage that penetrates obliquely upward from inside to outside.
The slit 16 is formed between the lower part of the coating solution tank 11 and the nozzle port 1.
The lower end of the slit 16 is open in the coating liquid tank 11 and the upper end thereof is a horizontally elongated nozzle port 12. . Further, the front end surface 151 of the front wall portion 15 facing the application surface SF of the substrate S is in a non-contact and predetermined gap with the application surface SF of the substrate S so that the liquid pool 4 of the application liquid can be formed. It is arranged to be close to G.

Further, an external tank 5 is provided in the coating liquid tank 11.
And a fixed-quantity discharge suction unit 8, as described later in detail, at the start of coating, first, a fixed amount of the coating liquid is supplied from the fixed-quantity discharge suction unit 8 to the coating liquid tank 11, and then the atmospheric pressure is applied. The coating liquid is supplied from the opened external tank 5 to the coating liquid tank 11 to initially form a liquid reservoir, and when the coating liquid in the coating liquid tank 11 is coated on the substrate S by the coating processing, the coating processing is performed. The application liquid corresponding to the amount consumed in the application tank is replenished from the external tank 5 to the coating liquid tank 11, so that the coating liquid tank 11 is always filled with the coating liquid. The constant-volume discharge suction unit 8 sucks and collects a constant amount of the application liquid from the above.

That is, a coating liquid supply pipe 91 is provided between the coating liquid tank 11 and the external tank 5, and one end of the coating liquid supply pipe 91 is connected to a lower central portion of the coating liquid tank 11. On the other hand, the other end is connected to the bottom of the external tank 5. An air valve 91a is inserted on the nozzle 1 side of the intermediate portion of the coating liquid supply pipe 91, while an air valve 91b is inserted on the external tank 5 side. Therefore, the flow of the coating liquid between the coating liquid tank 11 and the external tank 5 can be controlled by controlling the opening and closing of the air valves 91a and 91b. Thus, in this embodiment, the air valves 91a and 91b function as the first liquid flow control means.

An air release pipe 51 is connected to the upper surface of the external tank 5, and the interior of the external tank 5 is brought to atmospheric pressure by opening an air valve 51 a inserted in the air release pipe 51. Can be set. In addition, a supply pipe is inserted into the external tank 5 so that the application liquid can be supplied as described later. Further, the application liquid supply pipe 91 is provided with an air valve 91.
b and the external tank 5, the branch pipe 92 functions as a leak pipe for leaking the coating liquid in the external tank 5, and opens a valve 92 a inserted in the leak pipe 92. Thus, the application liquid can be extracted from the external tank 5.

The external tank 5 may be made of any material, but in this embodiment, for example, PTFE
(Polytetrafluoroethylene) or PFA (perfluoroalkoxy polymer).
The level of the coating liquid stored in the external tank 5 can be visually checked. A liquid level sensor 52 is attached to the side surface of the external tank 5 so that the liquid level sensor 52 can detect the liquid level of the coating liquid in the external tank 5 in a non-contact manner. ing. As the liquid level sensor 52, for example, each optical sensor 5 is provided at a plurality of appropriate places (here, three places) in the height direction of the external tank 5.
2a are provided to detect the liquid level of the coating liquid in the external tank 5, respectively.

As described above, the coating liquid tank 11 and the external tank 5
As shown in FIG. 2, a coating liquid supply pipe 91 communicating with
It is branched between the air valves 91a and 91b, and this branch pipe 93 is connected to one end of the fixed quantity discharge suction unit 8.

FIG. 3 is a schematic configuration diagram showing the configuration of the constant-rate discharge suction unit. This fixed-quantity discharge suction unit 8
The discharge suction mechanism 81 includes an air valve 82 connected to the nozzle side of the discharge suction mechanism 81 and an air valve 83 connected to a coating liquid supply source (FIG. 4) described later.

In the discharge / suction mechanism 81, a bellows 812 is provided at one end (the right hand side in the figure) of a discharge / suction body 811 for temporarily storing a coating liquid, so as to be extendable and contractible. Further, a ball screw 813 is provided in the discharge suction mechanism 81.
Extends from one end side of the discharge suction main body 811 in parallel with the direction in which the bellows 812 expands and contracts.
The ball screw 813 is configured to receive the rotational driving force of the pulse motor 815 via a drive transmission mechanism 814 including a belt 814c and a belt 814c stretched therebetween. A bracket 816 is screwed onto the ball screw 813, linearly moves along the ball screw 813 according to the rotational movement of the ball screw 813, and the bellows 812 expands and contracts according to the amount of movement. I have.

For this reason, for example, while the air valve 82 is open and the air valve 83 is closed, the pulse motor 81
5 by operating the bellows 812 in the contracted state (FIG. 7A).
To the extended state ((b) in the same figure), the bellows 8
The application liquid having an amount ΔQ corresponding to the expansion / contraction amount ΔL of the nozzle 12 is discharged from the discharge suction main body 811 to the nozzle side via the air valve 82. Conversely, while maintaining the air valves 82 and 83 as they are, the pulse motor 815 is rotated in the reverse direction to shift the bellows 812 from the expanded state (FIG. 2B) to the contracted state (FIG. 2A). And the amount of expansion and contraction ΔL of the bellows 812
Is applied from the nozzle side into the discharge suction main body 811 via the air valve 82. Further, when the bellows 812 is shifted from the contracted state ((a) in the figure) to the expanded state ((b) in the figure) with the air valve 82 closed and the air valve 83 opened, the application liquid of the amount ΔQ is discharged. The ink is discharged from the suction body 811 via the air valve 83, while the bellows 812 is in an extended state (FIG.
(b)) to the contracted state ((a) in the figure)
Is applied to the discharge / suction body 811 via the air valve 83.
Is sucked into.

As described above, according to the constant-quantity discharge suction unit 8, it is possible to discharge or suck a constant-quantity ΔQ application liquid. Moreover, since the amount ΔQ corresponds to the amount of expansion and contraction ΔL of the bellows 812, the amount of expansion and contraction ΔL can be adjusted by controlling the pulse motor 815, and the discharge amount and suction amount of the application liquid can be arbitrarily controlled.

In the present embodiment in which the nozzle 1, the external tank 5, and the fixed-quantity suction unit 8 are interconnected as described above, the coating liquid is supplied to the nozzle 1 by the fixed-quantity suction unit 8, or vice versa. In order to suck the application liquid from the nozzle 1, the air valve 91b must be opened with the air valve 91b closed to prevent the application liquid from flowing out of the external tank 5 and flowing into the external tank 5. In this embodiment, the air valve 91
“a” functions as second liquid flow control means for controlling the flow of the coating liquid between the coating liquid tank 11 and the fixed-quantity discharge suction unit 8. In this embodiment, the air valve 91a functions not only as the second liquid flow control means but also as the first liquid flow control means as described above.
Is inserted between the nozzle 1 and the air valve 91b instead of being provided between the nozzle 1 and the air valve 91b, the air valve 91b functions exclusively as the first liquid flow control means, and the air valve 91a exclusively functions as the second liquid flow control. Functions as a means.

In the above description, the interconnection relationship between the nozzle 1, the external tank 5, and the fixed-quantity discharge / suction unit 8 and the flow of the coating solution have been described. For the piping relationship of the entire coating apparatus including these components, see FIG. It will be explained while doing. As shown in FIG.
One end of a coating liquid supply pipe 94 is connected to the air valve 83 side, and the other end of the coating liquid supply pipe 94 is connected to a coating liquid supply source (tank) 95. An air valve 94a is interposed in the middle part of. The application liquid supply pipe 94 is branched between the fixed quantity discharge suction unit 8 and the air valve 94a, and the branch pipe 96 is connected to the external tank 5 via the air valve 96a and the filter 96b. Are inserted into the external tank 5 as described above. Therefore, the air valves 83, 94a, and 96a are appropriately opened and closed as described later, and the coating liquid supply source 9 is controlled.
When nitrogen gas or the like is blown into the gas supply tube 97 from the gas introduction pipe 97 via the valve 97 a, the application liquid stored in the application liquid supply source 95 is discharged from the discharge / suction main body 81 of the constant-rate discharge / suction unit 8.
1 or the external tank 5 is selectively supplied. When the air valves 83, 94a, and 96a are appropriately opened and closed as described later, and the fixed-quantity discharge suction unit 8 is operated, the coating liquid in the discharge suction main body 811 is supplied to the external tank 5.

Reference numeral 98 in the figure denotes a cable bearer which accommodates a portion of the coating liquid supply pipe 94 which protects a portion which bends and deforms as the nozzle 1 moves.

By the way, the nozzle 1 configured as described above is moved by the moving mechanism 6 described below to the suction stage 3.
And is moved along the surface to be coated SF (FIG. 2) of the substrate S. This moving mechanism 6
Is roughly divided into a vertical movement mechanism 61 that moves the nozzle 1 in the vertical direction, and a gap between the coating surface SF of the substrate S by moving the nozzle 1 close to or away from the substrate S. It comprises a variable gap mechanism 62 for adjustment and a nozzle rotating mechanism 63 for causing the nozzle port 12 of the nozzle 1 to face the application surface SF of the substrate S or to change the nozzle opening 12 downward.

As shown in FIG. 1, the vertical movement mechanism 61 moves the base member 611 supporting the nozzle 1 in the vertical direction, and has the following configuration.

In the vertical movement mechanism 61, two sets of four idle gears 612 are respectively rotatably provided at the upper and lower corners at both ends in the width direction on the front surface side and the rear surface side of the gantry 2. , Each of which is pivotally supported.
Then, the left and right steel belts 614 are wound around the two sets of left and right idle gears 612 located at the upper part, and the ends of the steel belts 614 are wound around the idle gears 612 located at the lower part. I have.
Further, both ends of the base member 611 are connected to the left and right steel belts 614 on the front side of the gantry 2, respectively, while both ends of the balance weight 615 are connected to the steel belt 614 on the back side.
The base member 611 includes the variable gap mechanism 62.
The nozzle 1 is attached via a nozzle rotation mechanism 63, and the external tank 5 and the fixed-quantity discharge suction unit 8 are detachably attached. The components on the front side of the gantry 2 (the nozzle 1, the external tank 5, the fixed-quantity discharge / suction unit 8, the base member 611, the variable gap mechanism 62 and the nozzle rotation mechanism 63), and the balance weight 615 on the back side However, the balance is maintained in a stationary state.

The stators 6 of the vertical linear motors 616 are respectively provided at both ends on the front surface side of the gantry 2.
17 are disposed, and these left and right linear motors 6 are provided.
The nozzle 1 is driven and controlled, and the left and right steel belts 614 are synchronously paid out from the front side to the back side, thereby moving the nozzle 1 relatively upward with respect to the substrate S while keeping the nozzle 1 horizontal, and rewinding the nozzle 1 in reverse. Thus, the nozzle 1 can be relatively moved downward while being kept horizontal. That is, both ends of the base member 611 on which the nozzle 1 is mounted are linearly moved up and down along each stator 617. The linear motor 616 as this moving means is
Both ends of the base member 611 and the inside of each of the steel belts 614 are respectively arranged along the respective steel belts 614 arranged in the up and down directions, and as shown in FIG. A stator 617 having a base 617b between the rails 617a;
11 has a slider member 618 that is disposed on each of the side walls on the back side of both ends to face each stator 617 and is slidable on each stator 617. The slider member 618 is provided on both sides in the width direction with the rail portions 61.
7a, each linear guide 618a is fitted between the linear guides 618a and guided in the vertical direction. The linear guides 618a are disposed between the linear guides 618a and face the base 617b of the stator 617. A magnetic circuit portion 618b for generating magnetic force by excitation, and a magnetic circuit portion 618b
618 connected to both ends of a winding (not shown)
The slider member 618 is guided by the respective rail portions 617a of the stator 617 by the respective linear guide portions 618a and can move up and down by the magnetic force generated by the excitation of the magnetic circuit portion 618b. The slider members 618 are fixed to the back sides of both ends of the base member 611 on which the nozzle 1 is mounted, and the base members 611 can be vertically moved by the movement of the slider members 618.

Here, both ends of the base member 611 on which the nozzle 1 is mounted are moved up and down along each stator 617. However, the nozzle 1 and the substrate S are relatively moved along the surface to be coated. The substrate S may be moved up and down together with the suction stage 3 by a moving means such as a linear motor or a ball screw while the nozzle 1 is fixed. Thus, the suction stage 3
Moving the suction stage 3 up and down has less vibration than moving the nozzle 1, and it is better to move the suction stage 3 from the viewpoint of preventing coating unevenness due to the vibration. However, since the height of the apparatus is required twice and the ceiling height of the clean room is limited, the installation of the apparatus becomes difficult. Reference numeral 64 in FIG. 1 denotes a cable carrier that accommodates wiring, a chemical supply tube, and the like.

FIG. 6 is a diagram showing the configuration of the variable gap mechanism 62 and the nozzle rotating mechanism 63 that constitute the moving mechanism 6. The variable gap mechanism 62 is connected to the base member 6.
The nozzle 1 and a nozzle rotation mechanism 63 described later are integrally moved with respect to the substrate S in the direction toward and away from the substrate S (the left-right direction in the figure). More specifically, the variable gap mechanism 62 is supported by a contact / separation motor 621 such as a stepping motor or a servomotor, and front and rear bearings 622 and 623. , A moving member 626 screwed to the ball screw 625, an upper end of the moving member 626 fixed to the lower surface, and supporting the nozzle rotation mechanism 63 to support the substrate S. A slide member 627 that is slidable so that the front end surface 151 of the nozzle 1 approaches or separates from the surface to be coated SF.
And a ball screw 6 by the contact / separation motor 621.
With the rotation of 25, the moving member 626 is configured to be movable back and forth with the nozzle 1 and the nozzle rotating mechanism 63 placed thereon.

Here, the variable gap mechanism 62 is provided at one central portion, but the number of variable gap mechanisms 62 is not limited to this, and a plurality of gap variable mechanisms 62 may be provided. The following effects can be obtained by disposing the gap variable mechanism 62 at two places on the left and right of the base member 611. That is, when there is a difference in the thickness dimension between the right and left ends at the right and left ends, there is a taper in the width direction of the substrate S.
The gap size between the nozzle 1 and the substrate S can be adjusted by operating each of the gap variable mechanisms 62 independently.

On the other hand, the nozzle rotating mechanism 63 is provided on the variable gap mechanism 62 configured as described above. In the nozzle rotation mechanism 63, an air cylinder 632 that moves the rod tip 631 between the extended position and the retracted position is controlled by an electromagnetic valve (not shown).
It is pivotally supported in the direction of the arrow C so as to be rotatable around a pin 633 at the front of the cylinder. This rod tip 63
Reference numeral 1 denotes a link mechanism which is rotatably pin-connected to one end of the arm member 634 to form a link mechanism.
Is fixed to the drive shaft 635 so as to be able to transmit rotational power from a direction perpendicular to the longitudinal direction. The drive shaft 635 includes a base member 636 extending horizontally with a predetermined width.
Is fixed by penetrating in the lateral direction through a support member 637 that supports from below. Above the front edge of the base member 636, the nozzle 1 has its nozzle port 12 connected to the surface S to be coated of the substrate S.
In the state facing the F side, the longitudinal direction of the nozzle 1 and the drive shaft 63
5 are mounted so that the axial directions thereof coincide with each other.

FIG. 6 shows a case where the rod tip 631 of the air cylinder 632 is extended.
Nozzle port 12 is in a state where it can be applied facing the application surface SF of the substrate S. In contrast, the air cylinder 63
When the rod end 631 of No. 2 is shortened, the nozzle 1
The nozzle opening 12 of FIG. 1 is in a state where it can be washed downward as indicated by a two-dot chain line. During the rod shortening, the rod tip 631 is shortened while the air cylinder 632 swings in the arrow direction C about the pin 633 as the center of rotation.

As described above, in this embodiment, the nozzle 1
Are moved up and down by a vertical moving mechanism 61 and can be moved closer to or away from the application surface SF of the substrate S by a variable gap mechanism 62. By controlling the vertical movement mechanism section 61 and the variable gap mechanism section 62 by a control structure described below, the nozzle 1 is moved in a state where the nozzle 1 and the substrate S are brought close to each other, and
Can be relatively moved with respect to. Further, the direction of relative movement of the nozzle 1 with respect to the substrate S can be appropriately switched. As for the method of moving the nozzle 1 up and down relative to the substrate S, instead of moving the nozzle 1 as described above, the suction stage 3
May be moved up and down, or both the nozzle 1 and the suction stage 3 may be moved.

FIG. 7 is a block diagram showing a schematic control configuration of the coating apparatus of FIG. In this coating apparatus, various keys, for example, a numeric keypad for inputting numbers, a power key for inputting power on / off, a coating start key, and a speed setting key for arbitrarily manually setting a reference value of a driving speed of the linear motor 616 Then, the contact / separation motor 621 is driven to drive the substrate S
An operation in which a gap setting key for adjusting the gap G between the coating surface SF and the nozzle port 12 and various setting keys for setting a substrate size, a substrate thickness, a coating liquid viscosity, a coating film thickness, and the like are appropriately arranged. An operation unit 71 is provided.
Is configured to input data, commands, and the like input via the control unit 72 to the control unit 72.

The control unit 72 includes a liquid level sensor 52, an RO
M73 and RAM 74 are connected to ROM 73
The control data used in each control program registered in the RAM and the data input from the operation unit 71 as described above can be written in the RAM 74.

The control section 72 to which the operation section 71, the ROM 73 and the RAM 74 are connected is connected to the linear motor 616 via the linear motor drive circuit 75, and the linear motor drive control registered in the ROM 73 is controlled. Based on the program and control data input from the operation unit 71 and corresponding to the linear motor drive control program, the control signal is output to the linear motor drive circuit 75, and the linear motor drive circuit 75 drives the linear motor 616. The nozzle 1 on the base member 611 can be movably controlled to a predetermined vertical position with respect to the application surface SF of the substrate S. The control unit 72 receives a linear motor drive control program registered in the ROM 73, inputs from various setting keys such as a substrate size, a coating liquid viscosity and a coating film thickness, and inputs a coating start key of the operation unit 71. Based on the control data corresponding to the linear motor drive control program, the linear motor 616 is driven via the linear motor drive circuit 75 to drive the nozzle at a predetermined speed and in the relative movement direction set by the operation unit 71. Control is performed so that coating is possible.

The control unit 72 is connected to the contact / separation motor 621 via the contact / separation motor drive circuit 76,
Based on the contact / separation motor drive control program registered in M73 and the control data input from the operation unit 71 and corresponding to the contact / separation motor drive control program, the control signal is output to the contact / separation motor drive circuit 76, The contact / separation motor drive circuit 76 drives the contact / separation motor 621 to drive the base member 611.
The upper nozzle 1 is controlled so as to approach or separate from the application surface SF of the substrate S.

The control unit 72 is connected to a pulse motor 815 via a pulse motor drive circuit 77.
Based on the pulse motor drive control program registered in the ROM 73 and control data input from the operation unit 71 and corresponding to the pulse motor drive control program, the control signal is output to the pulse motor drive circuit 77, and the pulse motor drive The circuit 77 drives the pulse motor 815 and the amount ΔQ of the application liquid discharged from the constant-rate discharge suction unit 8 and the amount ΔQ of the coating liquid sucked by the constant-rate discharge suction unit 8
Control.

Further, the control section 72 includes a valve drive circuit 7
.. Are controlled through the valve drive control program registered in the ROM 73 and the control data input from the operation unit 71. Drive circuit 7
8 and the valve drive circuit 78 outputs the air valve 51a,
.. Are driven to open and close to control the flow of the coating liquid.

Next, the operation of the coating apparatus configured as described above will be described with reference to FIGS. 4, 8 to 14.

First, a substrate S to be coated with a predetermined coating liquid is processed.
After being transported by a transport robot (not shown) or the like, the outer peripheral portion of the substrate S is positioned at a predetermined position in a state corresponding to the plurality of suction cups of the suction stage 3, and the coated surface of the substrate S faces outward. In this state, the substrate S is sucked by each suction cup. Further, each suction cup is pulled into a predetermined position in the concave portion 31 of the suction stage 3 and stored, thereby holding the substrate S.

When the setting of the substrate S is completed in this way, as shown in FIG. 4, the control unit 72 controls the coating surface of the substrate S in response to various setting keys input through the operation unit 71. In order to position the nozzle 1 at the origin position with respect to SF (upper end of the substrate S), the base member 61 together with the nozzle 1
1 is moved by the linear motor 616. Here, based on the linear motor drive control program registered in the ROM 73 and its control data, the control unit 72
By outputting the control signal to the linear motor drive circuit 75, the linear motor drive circuit 75
Is driven, the nozzle 1 on the base member 611 can be returned to the origin at a predetermined coating start position on the coating surface SF of the substrate S. The control data in this case is registered origin data when the holding position of the substrate S is precise, and may be data in which a predetermined height position is manually input from the operation unit 71. Good. Further, an origin sensor (not shown) is provided at the application start position of the application liquid, and the origin unit sensor (not shown) detects the base member 611 at a predetermined application start position.
The drive of the linear motor 616 may be controlled via the linear motor drive circuit 75 so as to stop the motor 1.

At this time, the nozzle 1, the external tank 5, the fixed-quantity discharge suction unit 8, and the air valve 51a,
.. Are set to the initial state. That is, as shown in FIG. 4, the nozzle 1 stands by at a position separated by the gap G3 from the substrate S in a state where the coating liquid tank 11 is filled with the coating liquid. Further, in the external tank 5, the coating liquid is stored at the same liquid level as the boundary position between the coating liquid tank 11 and the slit 16, as indicated by the one-dot broken line in FIG.
Further, a coating liquid having a capacity Q0 is stored in the discharge suction main body 811 of the fixed discharge discharge suction unit 8. Further, all the valves 51a, 91a, 91b, 92a,... Are closed.

When the positioning of the nozzle 1 to the coating start position is completed as described above, the gap between the coating surface SF of the substrate S and the nozzle 1 is subsequently reduced to a predetermined gap size G1.
The nozzle 1 is moved by the ball screw 625 and the moving member 626 driven by the contact / separation motor 621 so as to approach the application surface SF of the substrate S (see the white arrow in FIG. 8). At this time, based on the contact / separation motor drive control program registered in the ROM 73 and the control data, the control unit 72 outputs the output control signal to the contact / separation motor drive circuit 76, and the contact / separation motor drive circuit 76 The contact / separation motor 621 is driven to move the nozzle 1 on the base member 611 to a predetermined gap position with respect to the coating surface SF of the substrate S. The control data in this case may be gap data (predetermined gap position data) set and registered according to various application conditions such as the viscosity of the application liquid, the required application film thickness, and the application speed. The gap data may be manually input from the operation unit 71 with reference to experimental data corresponding to various conditions.
The same applies to gap data relating to the approach or retreat of the nozzle 1 to or from the substrate S described below.

Next, the controller 72 controls the air valve 91a,
By outputting a control signal to open the valve 82 to the valve drive circuit 78, the valve drive circuit 78
2 is driven to make the discharge suction mechanism 81 and the coating liquid tank 11 communicate with each other. Then, the control unit 72 controls the control signal to form a small amount reservoir 41 of a predetermined amount of the coating liquid through the operation unit 71 in the gap G1 between the coating surface SF of the substrate S and the nozzle 1. Is output to the pulse motor drive circuit 77 so that the pulse motor drive circuit 77
15 is driven to extend the bellows 812 by ΔL1. As a result, the amount of extension Δ
The coating liquid having a volume ΔQ1 corresponding to L1 is supplied to the air valves 82, 9
1a, the amount of the coating liquid Q1 pushed out of the coating liquid tank 11 into the gap G1 through the slit 16 and stored in the discharge suction mechanism 81 is Q1.
= Q0-ΔQ1. Thus, as shown in FIG.
A small amount of liquid reservoir 41 having a capacity ΔQ1 is formed in the gap G1.
In this embodiment, since the drive of the bellows 812 is controlled by using the pulse motor 815, the extension of the bellows 812 is controlled by adjusting the number of pulses given to the pulse motor 815 according to the type and viscosity of the application liquid. By changing the amount ΔL1, it is possible to control the volume ΔQ1 of the minute liquid reservoir 41.

As soon as the minute liquid reservoir 41 is formed as described above, the control unit 72 sends the valve drive control program registered in the ROM 73 and the valve control signal based on the control data to the valve drive circuit 78. By outputting, as shown in FIG. 9, the valve drive circuit 78 closes the air valve 82, opens the air valve 91b to connect the external tank 5 and the coating liquid tank 11, and simultaneously opens the air valve 51a to open the external The inside of the tank 5 is opened to the atmosphere and set to the atmospheric pressure. Then, the coating liquid in the coating liquid tank 11 is pumped to the substrate S side, and the trace liquid reservoir 41 tries to spread to the entire front end surface 151 of the nozzle 1 by capillary action. The coating liquid in the tank 5 is supplied to the coating liquid tank 11 via the air valves 91b and 91a. In this way, the coating liquid tank 11 is filled with the coating liquid while the liquid reservoir is expanded by receiving the supply of the coating liquid from the coating liquid tank 11.

In parallel with the enlargement of the liquid reservoir, the substrate S
In order to change the gap between the coating surface SF and the nozzle 1 to a predetermined gap dimension G2 (> G1) at the time of coating, the contact / separation motor 6
21 and the moving member 62
6, the nozzle 1 is moved so as to be separated from the application surface SF of the substrate S (see the white arrow in FIG. 9) to form a predetermined liquid reservoir 4, and the preparation for starting the application is completed. During this time, as the gap size G2 increases, the amount of the coating liquid in the liquid reservoir 4 also increases, and the coating liquid corresponding to the amount increases.
Pumped from.

When the application start key of the operation section 71 is operated to apply a predetermined coating film thickness to the application surface SF of the substrate S, the ROM 73 is kept in the ROM 73 with the air valves 51a, 91a and 91b opened. Based on the registered linear motor drive control program and the control data according to the predetermined relative movement direction and the coating film thickness, the control unit 72
The output control signal is output to the linear motor drive circuit 75, and the linear motor drive circuit 75 drives the linear motor 616 to move the base member 611 together with the nozzle 1 and the external tank 5 downward with respect to the application surface SF of the substrate S. The substrate S is moved while moving the nozzle (outline arrow in FIG. 10).
Is applied to the surface SF to be coated.

When the coating process is performed on the coating surface SF of the substrate S in this manner, the coating liquid in the coating liquid tank 11 is continuously pumped up, and the coating liquid in the coating liquid tank 11 is taken out. At the same time, the air valve 91
The coating liquid tank 11 is replenished via the b and 91a, and the coating liquid tank 11 is filled with the coating liquid.

When the coating process on the entire surface SF to be coated is completed as described above and the nozzle 1 stops at the final coating position (FIG. 11), the control unit 72 executes the valve drive control program registered in the ROM 73. By outputting a valve control signal based on the control data to the valve drive circuit 78,
The valve driving circuit 78 closes the air valves 91a and 91b, and opens the air valves 83 and 96a to open the external tank 5.
And the discharge suction mechanism 81 are brought into a communicating state. Note that the air valve 51a is still kept open, and the inside of the external tank 5 is opened to the atmosphere and kept at the atmospheric pressure.

Subsequently, the control section 72 operates the operation section 71.
The pulse motor drive circuit 77 drives the pulse motor 815 by outputting a control signal to the pulse motor drive circuit 77 in order to send the coating liquid to the external tank 5 by a predetermined amount ΔQ2 which is set in advance. Bellows 8
12 is extended by ΔL2. As a result, the application liquid having a capacity ΔQ2 corresponding to the expansion amount ΔL2 is supplied from the discharge suction mechanism 81 to the external tank 5 via the air valves 83 and 96a and the filter 96b, and the coating liquid amount Q2 stored in the discharge suction mechanism 81 Is as follows: Q2 = Q1−ΔQ2 = Q0− (ΔQ1 + ΔQ2) The reason why the coating liquid of the predetermined amount ΔQ2 is sent to the external tank 5 in order to prepare for the next suckback processing.

Next, the control section 72 outputs a valve drive control program based on the valve drive control program registered in the ROM 73 and the control data to the valve drive circuit 78, so that the valve drive circuit 78 causes the air valves 51a, 83 ,
While closing 96a, the air valves 91a and 82 are opened to bring the application liquid tank 11 into communication with the discharge suction mechanism 81, and then suck back processing is performed. That is, the control unit 72
The nozzle 1 is moved by the ball screw 625 and the moving member 626 driven by the contact / separation motor 621 to change the gap between the coating surface SF of the substrate S and the nozzle 1 to a predetermined gap dimension G1. It is moved so as to be close to SF (see the white arrow in FIG. 12), and a suck-back amount ΔQ preset through the operation unit 71 is set.
By outputting the control signal to the pulse motor drive circuit 77 in order to suck by 3 (= ΔQ1 + ΔQ2), the pulse motor drive circuit 77 drives the pulse motor 815 to contract the bellows 812 by ΔL3. by this,
The capacity ΔQ3 corresponding to the contraction amount ΔL3 from the coating solution tank 11
Is applied to the discharge / suction mechanism 81 via the air valves 91a and 82, and as a result, the excess application liquid at the final application position is returned to the application liquid tank 11. When sucking back the coating liquid of the predetermined amount ΔQ3 in this manner, the coating liquid amount Q3 stored in the discharge suction mechanism 81 is as follows: Q3 = Q2 + ΔQ3 = Q2 + (ΔQ1 + ΔQ2) = Q0, and the coating liquid stored in the discharge suction mechanism 81 The amount will be the same as at the start of the application.

When the suck-back process is completed as described above, the control section 72 outputs a valve drive control program registered in the ROM 73 and a valve control signal based on the control data to the valve drive circuit 78 so as to output the valve control signal. After the drive circuit 78 closes the air valves 91a, 82 and closes all the valves 51a, 91a,..., The control circuit 78 outputs a control signal based on the linear motor drive control program and its control data to the linear motor drive circuit 75, A control signal based on the contact / separation motor drive control program and its control data is output to the contact / separation motor drive circuit 76,
The nozzle 1 is retracted to a standby position (not shown).

After the coating process on one substrate S is completed in this way and the suction holding of the substrate S by the suction stage 3 is released, the substrate S is transferred to a post-processing step by a transfer robot or the like. Then, when the next substrate S is transported, the above series of operations is repeated to execute the coating process.

In the coating apparatus according to the above embodiment, since the coating liquid tank 11 is always filled with the coating liquid, only the amount consumed by the coating processing is stored in the external tank 5 or the discharge suction mechanism 81. The amount of coating liquid decreases. Therefore, in this embodiment, each time the series of operations is performed once or a plurality of times, the coating liquid supply source 9 is turned on.
5, the application liquid is supplied.

FIG. 13 and FIG. 14 are diagrams showing a process of replenishing the external tank 5 with the application liquid using the fixed quantity discharge suction unit 8. In the replenishment process, as shown in FIG. 13, the control unit 72 outputs a valve drive control program registered in the ROM 73 and a valve control signal based on the control data to the valve drive circuit 78, so that the valve drive circuit 78 operates. The circuit 78 opens the air valves 83 and 96a to make the external tank 5 and the discharge suction mechanism 81 communicate with each other, and opens the air valve 51a to open the inside of the external tank 5 to the atmospheric pressure and set the atmospheric pressure. After that, the control unit 72
By outputting a control signal to the pulse motor drive circuit 77 to send the replenishment amount ΔQ4 to the external tank 5, the pulse motor drive circuit 77 drives the pulse motor 815 to extend the bellows 812 by ΔL4. As a result, the application liquid having a capacity ΔQ4 corresponding to the expansion amount ΔL4 is supplied from the discharge suction mechanism 81 to the air valves 83 and 96a,
It is supplied to the external tank 5 via the filter 96b. On the other hand, in the discharge suction mechanism 81, the amount of the coating liquid stored by the supply amount ΔQ4 decreases, and the amount of the coating liquid becomes Q4.

Therefore, as shown in FIG.
Outputs a valve drive control program registered in the ROM 73 and a valve control signal based on the control data to the valve drive circuit 78 so that the valve drive circuit 78 closes the air valves 51a and 96a while the air valve 94
a is opened to make the application liquid supply source 95 and the discharge suction mechanism 81 communicate with each other. Subsequently, while opening the valve 97 a and introducing nitrogen gas into the coating liquid supply source 95,
Is a replenishment amount ΔQ5 preset via the operation unit 71.
By outputting the control signal to the pulse motor drive circuit 77 in order to replenish the bellows, the pulse motor drive circuit 77 drives the pulse motor 815 to drive the bellows 812 to ΔL5
Just shrink. As a result, the coating liquid having a capacity ΔQ5 corresponding to the contraction amount ΔL5 is sucked from the coating liquid supply source 95 to the discharge suction mechanism 81 via the air valves 94a and 83, and as a result, the coating liquid stored in the discharge suction mechanism 81 The amount is (Q4 + ΔQ5), and is returned to the same amount Q0 as at the start of coating.

The external tank 5 is supplied from the coating liquid supply source 95.
May be directly supplied with a coating liquid. When it is not necessary to replenish the external tank 5 and only replenish the discharge suction mechanism 81, only the replenishment process shown in FIG. 14 may be performed.

As described above, according to the coating apparatus of this embodiment, the following effects can be obtained, and the coating apparatus can be modified as follows.

(1) The external tank 5 is provided separately and independently from the nozzle 1, and the nozzle 1 and the external tank 5 are communicated with each other to appropriately replenish the coating liquid in the coating liquid tank 11 provided in the nozzle 1. Since the coating liquid tank 11 is always filled with the coating liquid, the coating liquid in the nozzle 1 can be prevented from gelling, and the necessity of the detachment cleaning processing of the nozzle 1 is greatly reduced. Can be reduced. For this reason, the number of times of attaching and detaching the nozzles 1 can be minimized, and the reproducibility and stability of the coating performance can be improved as compared with the conventional coating apparatus which requires the cleaning to be performed at a high frequency. In addition, since the gelation can be prevented and the contamination inside the nozzle 1 can be suppressed as described above, the nozzle 1 can be formed of a material such as a metal that can be precisely machined. Can be further improved in reproducibility and stability.

(2) Since the coating liquid tank 11 is always filled with the coating liquid and does not contain air as described above, even if the direction of the nozzle 1 is changed, the liquid spilling from the nozzle 1 is prevented. can do. Therefore, as compared with the conventional coating apparatus in which the standby position and the cleaning position of the nozzle have to be considered so that the liquid does not spill as in the related art, the design limitation due to the direction of the nozzle 1 is reduced, and the design is reduced. The degree of freedom can be increased.

(3) On the other hand, the external tank 5 is opened to the atmosphere in order to replenish the nozzle 1 with the coating liquid. A gas phase exists inside the external tank 5 and the coating liquid is gelled. However, unlike the nozzle 1, the external tank 5 does not adversely affect the coating performance even if it is detached and cleaned, so that the external tank 5 can be appropriately detached and cleaned as needed, and is excellent in maintenance. . Although the above-described effects can be obtained even if the external tank 5 is formed of any material, particularly, PTFE or PFA as in the embodiment is used.
When it is formed of such a resin material as above, the cleaning property can be further improved.

(4) In the above embodiment, the external tank 5 is formed of a resin material, and the entire external tank 5 is in a transparent or translucent state. The amount of the coating liquid stored in the container can be visually checked, and it is easy to check the liquid level and to replenish the coating liquid before the liquid level is significantly reduced. Note that, from this point, the external tank 5 may be formed of a transparent material such as glass. Further, if only the visual check of the liquid level is considered, it is not necessary to form the entire outer tank 5 with a transparent or translucent material, and at least a part of the outer tank 5 is formed with a transparent or translucent material. What is necessary is just to comprise so that the liquid level may be visually checked in the said area | region.

(5) In addition, since the liquid level sensor 52 is provided in the viewable area (the side area of the external tank 5 in the above embodiment), it is possible to automatically check the liquid level. That is, based on the detection signal from the liquid level sensor 52, when the control unit 72 confirms that the liquid level is not within the predetermined range, the control unit 72 warns the operator to that effect. Work load can be reduced.

(6) In the above embodiment, a fixed amount of application liquid is supplied to the application liquid tank 11 by the constant-quantity discharge / suction unit 8 so that a small amount of liquid is stored between the substrate S and the nozzle 1 before the start of application. Since the liquid reservoir 41 is formed, it is possible to form an appropriate liquid reservoir 4 with no excess or shortage at the start of the application, and it is possible to prevent problems such as dripping and poor application. In particular, in the above-described embodiment, since the amount of the coating liquid supplied to form the minute liquid pool portion 41 at the start of coating can be adjusted, the optimum amount of the micro liquid pool corresponding to the type and viscosity of the coating liquid can be adjusted. The part 41 can be formed.

(7) Further, since the surplus application liquid is suctioned and collected at the final application position by the constant-quantity discharge suction unit 8, the film thickness increases at the final application position and the lower end of the substrate S The coating liquid can be applied to the substrate with an appropriate film thickness by preventing the coating liquid from flowing into the part. In addition, since the surplus coating liquid is prevented from adhering to the nozzle 1, it is not necessary to clean the nozzle 1 and the like every time the processing is completed, and the coating processing can be performed with high throughput. In addition, since the collected coating liquid is reused, the coating liquid can be used without waste. In the above embodiment, since the amount of the coating liquid to be suctioned and collected can be adjusted, it can be controlled according to the type and viscosity of the coating liquid, and the versatility of the coating apparatus can be improved.

(8) In the above embodiment, the fixed-quantity discharge suction unit 8 capable of performing fixed-quantity discharge and constant-quantity suction is provided. Only one of the suction mechanisms may be provided, or each may be separately provided.

(9) Further, when the coating process is not performed, the air valve is closed to prevent the presence of a compressible gas phase. Therefore, even if the nozzle 1 is turned downward, Liquid dripping and accompanying air mixing are eliminated, and the nozzle 1 can be set at any position and posture.

[0116]

As described above, according to the present invention, a part of the coating liquid in the coating liquid tank is pumped and applied to the surface to be coated of the substrate, and at the same time, the amount of the pumped coating liquid is reduced. Since the corresponding coating liquid is replenished from the external tank to the coating liquid tank so that the coating liquid tank is always filled with the coating liquid, on the nozzle means side, there is no gas phase in the coating liquid tank,
Gelling of the coating solution in the coating solution tank can be prevented to prevent contamination in the coating solution tank, and as a result, reproducibility and stability of coating performance can be improved.

On the other hand, in an external tank that is open to the atmosphere, the coating solution gels. However, since the external tank is not directly related to the coating performance, the external tank can be appropriately cleaned as needed, The external tank can be designed in consideration of the above.

Further, even if the nozzle means is oriented in an arbitrary direction, the coating liquid does not flow out of the nozzle means.
Each part of the coating apparatus can be designed without considering the nozzle attitude.

Further, an area where the liquid level of the coating liquid can be visually confirmed is formed in the external tank, and the liquid level of the coating liquid in the external tank can be visually confirmed through the visible area. It is easy to check the liquid level and to replenish the coating liquid before the liquid level significantly decreases. In particular, by providing the liquid level detecting means in the viewable area, the liquid level can be automatically detected.

Further, since the flow of the coating liquid between the coating liquid tank and the external tank is controlled by the first liquid flow control means, the coating liquid between the coating liquid tank and the external tank is controlled. Even if the flow of the liquid is prohibited and the nozzle attitude is, for example, downward, the coating liquid is effectively prevented from flowing out of the nozzle means. Therefore, the degree of freedom in designing the coating apparatus can be increased without relatively considering the direction of the nozzle means in designing the coating apparatus.

In a state where the supply of the coating liquid from the external tank to the coating liquid tank is prohibited by the first liquid flow control means,
Since a fixed amount of application liquid is supplied from the constant amount discharge means to the application liquid tank via the second liquid flow control means, and a minute liquid reservoir is formed between the nozzle means and the surface to be applied. In addition, problems such as dripping and poor coating can be prevented.

In a state where the inflow of the coating liquid from the coating liquid tank to the external tank is prohibited by the first liquid flow control means,
A fixed amount of the coating solution is removed from the coating solution tank by the
Since it is configured to be sucked and collected through the liquid flow control means, it is possible to prevent an increase in the film thickness at the final coating position and to prevent the coating liquid from flowing to the lower edge of the substrate, and to prevent the liquid from flowing. The coating liquid can be applied to the substrate with a large thickness. Moreover, since the excess coating solution is prevented from adhering to the nozzle means, it is not necessary to clean the nozzle means etc. every time the processing is completed.
The coating process can be performed with high throughput. Moreover, if the collected coating liquid is reused, the coating liquid can be used without waste.

Further, since the discharge amount of the coating liquid to the coating liquid tank is controlled according to the contents of the discharge processing, an appropriate minute liquid reservoir can be always formed. Similarly, since the configuration is such that the amount of the coating liquid to be suctioned and collected can be adjusted, it can be controlled according to the type and viscosity of the coating liquid, and the versatility of the coating apparatus can be improved. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a coating apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration and an interconnecting relationship of a nozzle, an external tank, and a fixed-quantity discharge suction unit in the coating apparatus of FIG.

FIG. 3 is a schematic configuration diagram showing a configuration of a fixed-quantity discharge suction unit.

FIG. 4 is a view showing a piping system in the coating apparatus of FIG.

FIG. 5 is a partially cutaway perspective view showing a schematic configuration of the linear motor of FIG. 1;

FIG. 6 is a diagram illustrating the configuration of a variable gap mechanism and a nozzle rotation mechanism that constitute a moving mechanism.

FIG. 7 is a block diagram illustrating a schematic control configuration of the coating apparatus of FIG. 1;

FIG. 8 is a view showing the operation of the coating apparatus of FIG.

FIG. 9 is a view showing the operation of the coating apparatus of FIG. 1;

FIG. 10 is a view showing the operation of the coating apparatus of FIG. 1;

FIG. 11 is a view showing the operation of the coating apparatus of FIG. 1;

FIG. 12 is a view showing the operation of the coating apparatus of FIG. 1;

FIG. 13 is a view showing the operation of the coating apparatus of FIG. 1;

FIG. 14 is a view showing the operation of the coating apparatus of FIG. 1;

FIG. 15 is a front view showing a schematic configuration of a coating apparatus according to a proposal example.

FIG. 16 is a sectional view taken along line AA in the coating apparatus of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Nozzle 3 Suction stage (substrate holding means) 5 External tank 6 Moving mechanism 8 Quantitative discharge suction unit 11 Application liquid tank 51a, 82, 83, 91a, 91b, 96a Air valve 52 Liquid level sensor 52a Optical sensor 63 Nozzle rotation mechanism 72 control unit 81 discharge suction mechanism SF coated surface S substrate

Claims (16)

[Claims] A substrate holding means for holding the substrate in a vertical or inclined posture; and a coating liquid tank for temporarily storing a coating liquid, wherein the coating liquid in the coating liquid tank is directed toward the surface to be coated. A nozzle means configured to be capable of being supplied, and an external tank configured to store the coating liquid in a state of being opened to the atmosphere, communicate with the coating liquid tank, and refill the coating liquid tank with the coating liquid, Moving means for relatively moving the nozzle means along an application surface of the substrate in a state where the nozzle means is brought close to the substrate held by the substrate holding means; While the substrate and the substrate are relatively moved in a state of being brought close to each other, the coating liquid pumped up from the coating liquid tank by capillary action is applied to the coating surface of the substrate, and the coating is performed by the coating process. Liquid tank Coating apparatus, wherein the application liquid chamber by the coating liquid amount pumped et been supplemented from the external tank is filled continuously with the coating solution. 2. An external tank, wherein at least a part of the external tank is made of a transparent or translucent material, and a region in which the liquid level of the coating liquid stored in the external tank can be visually observed is formed in the external tank. The coating device according to claim 1. 3. The coating apparatus according to claim 2, further comprising a liquid level detecting means provided in the viewable area and detecting a liquid level of the coating liquid stored in the external tank in a non-contact manner. 4. The method according to claim 1, further comprising a first liquid flow control means provided between said coating liquid tank and said external tank and capable of controlling the flow of the coating liquid between them. A coating device according to any one of the above. 5. A fixed-quantity discharge unit which is communicated with the coating liquid tank of the nozzle means and discharges a predetermined amount of the coating liquid to the coating liquid tank; and between the coating liquid tank and the fixed-quantity discharge means. 5. The coating apparatus according to claim 4, further comprising: a second liquid flow control unit that is provided in the apparatus and that can control a flow of the coating liquid therebetween. 6. A constant-quantity suction means which is communicated with the coating liquid tank of the nozzle means and performs a suction process of a fixed amount of the coating liquid from the coating liquid tank, and between the coating liquid tank and the constant-quantity suction means. The coating apparatus according to claim 4, further comprising: a third liquid flow control unit provided in the apparatus, and capable of controlling a flow of the coating liquid therebetween. 7. A process in which the nozzle means communicates with the coating solution tank to select a process of discharging a predetermined amount of the coating solution to the coating solution tank and a process of suctioning a predetermined amount of the coating solution from the coating solution tank. A constant discharge and suction unit that can be performed in a fixed manner; and a second liquid flow control unit that is provided between the coating liquid tank and the constant discharge and suction unit and that can control the flow of the coating liquid therebetween. The coating device according to claim 4, further comprising: 8. The coating apparatus according to claim 5, wherein a discharge amount of the coating liquid to the coating liquid tank can be changed every discharge processing. 9. The coating apparatus according to claim 6, wherein a suction amount of the coating liquid from the coating liquid tank can be changed every suction processing. 10. The apparatus according to claim 4, wherein the moving means has a nozzle rotating mechanism for changing the direction of the nozzle means by rotating the nozzle means around a predetermined center of rotation. Coating equipment. 11. A nozzle which is stored in a coating liquid tank provided inside the nozzle means in a state where the nozzle means is relatively moved along the coating surface of the substrate held in a vertical or inclined posture. Pumped by the capillary action
In the coating method for coating on the surface to be coated, a coating liquid is replenished from an external tank provided independently of the nozzle means by an amount of the coating liquid pumped up from the coating liquid tank by the coating processing, and A coating method, wherein the liquid tank is always filled with a coating liquid. 12. The coating method according to claim 11, wherein the flow of the coating liquid between the coating liquid tank and the external tank is prohibited as required. 13. At the start of application of a coating liquid to a substrate, a flow of the coating liquid is prohibited between the coating liquid tank and the external tank, and a fixed amount of the coating liquid is discharged to the coating liquid tank. 13. The coating method according to claim 12, wherein a minute liquid pool is formed between the nozzle means and the surface to be coated. 14. The coating method according to claim 13, wherein the discharge amount of the coating liquid to the coating liquid tank is changed in accordance with the discharging processing each time the processing for discharging the coating liquid to the coating liquid tank is performed. 15. When the nozzle means is positioned at a final coating position on the surface to be coated, the flow of the coating liquid between the coating liquid tank and the external tank is inhibited, and the nozzle means is moved to the position to be coated. The coating method according to any one of claims 12 to 14, wherein a fixed amount of the coating liquid is sucked from the coating liquid tank while approaching the surface. 16. The coating method according to claim 15, wherein the suction amount of the coating liquid from the coating liquid tank is changed in accordance with the suction processing each time the suction processing of the coating liquid from the coating liquid tank is performed.