TW201325728A - Method for cleaning cap and coating apparatus - Google Patents

Abstract

To obtain a desired washing result in a short period of time for a cap 3, long in width direction, having an opening at a tip and a slit 7 formed inside, by enabling the floatation of adhered substances which have been left in conventional cases due to the insufficient propagation of vibration waves (cavitation based on vibration waves). The front end of the cap 9 is dipped into a cleaning fluid L with vibration waves applied from a cleaning tank 11 to inflow the liquid L through a slit 7. From this state, a gas is allowed to flow into the cap through the slit 7 over the whole width length of the slit 7. Subsequently, the front end of the cap 9 is dipped into the cleaning fluid L with vibration waves applied from a cleaning tank 11; and the cleaning fluid L is allowed to flow into the cap through the slit 7.

Description

Nozzle cleaning method and coating device

The present invention relates to a nozzle cleaning method for cleaning a nozzle for ejecting a coating liquid to a substrate, and a coating device capable of performing the cleaning method.

For a flat panel display such as a liquid crystal display or a solar cell panel, a substrate on which a pixel, a circuit pattern, or the like is formed is used. These substrates are photolithography by using, for example, a photoresist (coating liquid). Made out of technology.

Further, as a device for applying a coating liquid to a substrate, a coating device having a nozzle having a slit having a long width in the inside is known. According to this coating apparatus, the nozzle is horizontally moved with respect to the substrate, and the coating liquid is ejected from the slit, whereby a film of the coating liquid can be formed on the surface of the substrate.

When the coating apparatus is continuously applied for a long period of time, the cured product of the coating liquid or the coating may be fixed to the slit, the nozzle tip of the slit opening, and the outer surface of the nozzle tip. A fixing substance such as a foreign matter in the cloth liquid may cause the coating material to be affected by the ejection of the coating liquid.

Therefore, a cleaning device such as a cleaning nozzle disclosed in Patent Document 1 has been proposed.

The cleaning device includes a cleaning tank for storing the cleaning liquid, and immersing the tip end of the nozzle in the cleaning liquid, and a flow path for flowing the cleaning liquid to the nozzle (slit). Further, an ultrasonic vibrator for imparting ultrasonic vibration to the cleaning liquid is provided in the middle of the flow path, and the ultrasonic vibration is attached thereto by the ultrasonic vibration. The fixing inside the nozzle floats to enhance the cleaning effect.

[Practical Technical Literature] [Patent Literature]

Patent Document 1: JP-A-2007-253093 (refer to Figs. 1, 2, and 3)

However, in the cleaning device described in Patent Document 1, the position at which the ultrasonic vibration is applied to the cleaning liquid is away from the nozzle (slit) in the middle of the flow path through which the cleaning liquid flows, so that the vibration energy of the ultrasonic wave is deteriorated. It is expected to improve the cleaning effect of the nozzle.

Therefore, it has been thought that a vibrator is provided at the bottom of the washing tank in which the ultrasonic wave is applied to the cleaning liquid at a position close to the nozzle front end, for example, at the bottom of the washing tank in which the cleaning liquid is stored and the nozzle tip is immersed in the cleaning liquid. The vibration wave (ultrasonic vibration) is applied to the cleaning liquid to clean the nozzle.

However, the vibration wave (ultrasonic vibration) is applied to the cleaning liquid only by the vibrator provided near the tip end of the nozzle immersed in the cleaning liquid, and the nozzle tip of the slit opening and the outer surface of the nozzle tip can be cleaned. It is clean, but the vibration wave (cavity caused by the vibration wave) in the cleaning liquid cannot reach the slit with a very narrow opening width (especially deep in the slit away from the front end of the nozzle), and the slit cannot be solidified. The objects are cleaned.

Therefore, in order to make the vibration wave (the action of holes caused by the vibration wave) in the cleaning liquid reach the slit of the nozzle (deep in the slit), it is thought that the vibration wave (ultrasonic wave) is sucked from the tip end of the nozzle. The method of cleaning the liquid.

However, in the region where the fixing material is fixed, the cleaning liquid does not easily flow due to the resistance of the fixing material. Therefore, when the cleaning liquid containing the cavitation action is sucked only from the nozzle, the cleaning liquid flows away from the fixing material. The cavitation does not reach the sessile material, and the sessile material cannot be effectively cleaned. All of the above are problems.

In other words, in the past, the cleaning effect was weak, and it was difficult to take all the slits (nozzles) in the wide direction. To obtain the uniform cleaning result, and to obtain the cleaning result, it is necessary to repeat the cleaning and take a lot of cleaning time. Therefore, it takes time before restarting the coating operation, which hinders the improvement of production efficiency.

Accordingly, it is an object of the present invention to provide a nozzle cleaning method and a coating apparatus capable of performing the cleaning method; the nozzle cleaning method is capable of causing insufficient propagation of a conventional vibration wave (cavity caused by a vibration wave) The residual solid material floats out and effectively achieves a uniform cleaning result in a short period of time.

The nozzle cleaning method of the present invention is a nozzle cleaning method in which a slit which is long in the width direction and opens at the front end is formed in the nozzle; the nozzle cleaning method is characterized in that: the first inflow step includes the nozzle front end Immersed in a cleaning liquid with a vibration wave in the cleaning tank so that the cleaning liquid flows into the nozzle through the slit; and in the gas inflow step, in a state in which the cleaning liquid flows into the nozzle inside the first inflow step, The gas is passed over the entire length of the slit in the width direction, and flows into the nozzle through the slit; and in the second inflow step, after the gas inflow step, the tip of the nozzle is immersed in the cleaning tank with vibration wave cleaning In the liquid, the cleaning liquid flows into the nozzle through the slit.

According to the invention, in the first inflow step, the cleaning liquid with the vibration wave is caused to flow into the inside of the nozzle, whereby the anchor fixed to the inside of the nozzle can be floated. In a state in which the cleaning liquid flows into the inside of the nozzle, the gas flows through the slit in the entire width direction of the slit, and flows into the nozzle through the slit, whereby the gas-liquid interface of the gas and the cleaning liquid can be spread over the entire length of the slit. mobile. As a result, the effect of peeling off the anchor can be brought inside the nozzle, and when the cleaning liquid with the vibration wave is again flowed into the nozzle in the second inflow step, the vibration wave (caused by the vibration wave) can be caused. The phenomenon (path) of the cavitation propagation changes from the first inflow step, so that the propagation of the vibration wave is insufficient and the residual solid material floats. As a result, the desired cleaning result can be obtained in a short time.

Further, in the gas inflow step, the nozzle tip is separated from the liquid level of the cleaning liquid. The gas is then passed over the entire length of the slit in the width direction, and flows into the inside of the nozzle through the slit.

In this case, the nozzle tip is immersed in the cleaning liquid in the cleaning tank, and the nozzle tip is separated from the liquid surface of the cleaning liquid. The gas can be easily passed over the entire length of the slit. The slit flows into the inside of the nozzle.

When the first inflow step is shifted to the gas inflow step, the cleaning liquid flowing to the inside of the nozzle contains a large amount of gas. Therefore, the gas is dissolved in the cleaning liquid. Therefore, the cleaning liquid is returned to the cleaning tank as it is, and then the first step is performed. In the inflow step (or the second inflow step), a vibration wave is supplied to the cleaning liquid having an increased dissolved gas amount. At this time, there is a possibility that the generation of cavitation caused by the vibration wave in the cleaning liquid is hindered by the dissolved gas, and the effect of causing the anchor to float by the action of the holes is weakened.

Therefore, the nozzle cleaning method preferably further includes a gas discharge step of passing the cleaning liquid through a flow path filled with the cleaning liquid flowing from the slit in the first inflow step and the second inflow step. The gas that has flowed into the cleaning tank and that has flowed in the gas inflow step is discharged from the flow path through a discharge flow path different from the slit. Further, the "cleaning liquid returned to the washing tank" may be a washing liquid that flows in from the slit in the first inflow step and the second inflow step, or may be a new washing liquid. When the cleaning liquid flowing in from the slit is returned, the gas contained in the cleaning liquid is discharged through the discharge flow path. In the case of a new cleaning liquid, the gas contained in the cleaning liquid flowing from the slit is discharged together with the cleaning liquid through the discharge flow path, and the new cleaning liquid is returned to the cleaning tank instead of the cleaning liquid.

In this case, even if the cleaning liquid is returned to the cleaning tank, the amount of dissolved gas in the cleaning liquid in the cleaning tank can be suppressed from increasing; even if the first inflow step (or the second inflow step) is performed later, the vibration wave can be prevented from being solidified. The effect of the object floating is weakened.

Further, when a vibration wave is supplied to the cleaning liquid and the foreign matter is floated in the cleaning tank, the floating foreign matter in the cleaning tank may be sucked into the nozzle together with the cleaning liquid according to one or both of the first inflow step and the second inflow step. Internal side.

Therefore, the nozzle cleaning method further includes a finishing step of cleaning the one or both of the first inflow step and the second inflow step in a state where the tip of the nozzle is immersed in the cleaning liquid of the cleaning tank. After the liquid flows into the inner side of the nozzle, the cleaning liquid is ejected from the slit (inflow or new from the slit); in the finishing step, the cleaning tank should be cleaned The washing liquid is supplied with a vibration wave and maintained in its original state, and the tip end of the nozzle immersed in the washing liquid in the washing tank is separated from the liquid surface of the washing liquid.

At this time, even if the floating foreign matter in the cleaning tank is sucked into the inside of the nozzle together with the cleaning liquid, the liquid contact surface adhering to the inside of the nozzle is ejected to the cleaning tank according to the finishing step (inflow from the slit or new) The cleaning liquid is caused to cause foreign matter in the cleaning tank attached to the liquid contact surface inside the nozzle to float due to the vibration wave and to be ejected from the inside of the nozzle. Further, the cleaning liquid in the cleaning tank is supplied with a vibration wave and maintained in the original state, and the nozzle tip of the cleaning liquid immersed in the cleaning tank is separated from the liquid surface of the cleaning liquid, so that foreign matter floating in the cleaning tank can be temporarily prevented. Attached again inside the nozzle and to the front end of the nozzle. As a result, it is possible to quickly transfer to the coating operation without a human hand after the end of the cleaning operation.

In particular, when a foreign matter floating in the cleaning tank floats in the slit due to vibration waves and easily enters the inside of the nozzle (specific gravity, size, etc.), one or both of the first inflow step and the second inflow step are used. It is easy to suck the floating foreign matter in the washing tank together with the washing liquid into the inside of the nozzle.

In this case, the nozzle cleaning method further includes a finishing step of causing one or both of the first inflow step and the second inflow step in a state where the tip of the nozzle is immersed in the cleaning liquid of the cleaning tank. After the cleaning liquid flows into the inner side of the nozzle, the cleaning liquid is ejected from the slit (inflow or new from the slit); in the finishing step, the cleaning liquid is preferably sprayed in the cleaning tank. In the middle, the application of the vibration wave to the cleaning liquid in the cleaning tank is stopped.

At this time, even if the floating foreign matter in the washing tank is sucked into the inside of the nozzle together with the cleaning liquid, according to the finishing step, while the vibration wave is applied to the cleaning liquid in the cleaning tank, the cleaning tank is ejected (from the slit). The inflowing or new cleaning liquid can thereby easily eject the floating foreign matter sucked into the cleaning tank inside the nozzle from the inside of the nozzle. Furthermore, at this time, ultrasonic waves can be applied to prevent foreign matter from adhering to the tip end of the nozzle. Further, while the cleaning liquid is ejected into the cleaning tank, the vibration wave is prevented from being applied to the cleaning liquid in the cleaning tank. Therefore, it is possible to prevent the foreign matter in the cleaning tank from sinking and floating in the cleaning tank due to the vibration wave, thereby preventing foreign matter from adhering to the cleaning tank. The front end of the nozzle. As a result, it is possible to quickly transfer to the coating operation without a human hand after the end of the cleaning operation.

Moreover, the nozzle cleaning method is characterized in that the ultrasonic vibrator is vibrated at a low frequency so that When the first inflow step is performed after the first inflow step and the second inflow step, the vibration flow is generated, and the cleaning step is preferably performed before the first inflow step is performed again. Replacement steps to replace at least a portion of the fluid.

At this time, the ultrasonic vibrator is vibrated at a low frequency, and the first inflow step and the second inflow step are performed by generating the vibration wave, whereby the cleaning effect of the nozzle can be further improved. In addition, the low frequency is 20 kHz or more and 40 kHz or less. However, at these low frequencies, the temperature of the cleaning liquid is likely to rise, and when the first inflow step is performed again, the temperature of the nozzle also rises when the cleaning liquid flows into the inside of the nozzle. At this time, the thermal expansion of the nozzle changes the size of the slit, and if the coating operation is performed immediately using the nozzle, the coating quality may be affected. Therefore, it is necessary to stop the operation until the temperature of the cleaning liquid drops to a predetermined temperature, resulting in waste of time. Therefore, in such a case, at least a part of the cleaning liquid in the cleaning tank is replaced by the replacement step, and the first inflow step can be prevented from being performed again by the cleaning liquid having a temperature rise.

Further, the nozzle cleaning method preferably further includes a continuous replacement step of replacing at least a part of the cleaning liquid of the cleaning tank while the ultrasonic vibrator is vibrated at a low frequency to generate the vibration wave.

In this case, the ultrasonic vibrator is vibrated at a low frequency (20 kHz or more and 40 kHz or less) to generate a vibration wave, thereby further improving the cleaning effect of the nozzle; however, at such low frequencies, the temperature of the cleaning liquid is likely to rise. When the cleaning liquid is then made to flow into the inside of the nozzle, the temperature of the nozzle also rises. At this time, the thermal expansion of the nozzle changes the size of the slit, and if the coating operation is performed immediately using the nozzle, the coating quality may be affected. Therefore, it is necessary to stop the operation until the temperature of the cleaning liquid drops to a predetermined temperature, resulting in waste of time. Therefore, in such a case, at least a part of the cleaning liquid of the cleaning tank can be replaced by the continuous replacement step, so as to avoid the use of the cleaning liquid having a rising temperature.

Further, the coating apparatus of the present invention includes a device main body having a nozzle formed therein with a slit that is long in the width direction and opened at the front end, and ejects the coating liquid from the slit to the substrate. a coating; and a cleaning mechanism for cleaning the nozzle; the coating device is characterized in that the cleaning mechanism comprises: a cleaning tank for storing the cleaning liquid; an oscillating device for supplying a vibration wave to the cleaning liquid in the cleaning tank; and a liquid feeding mechanism for immersing the cleaning liquid with a vibration wave in the cleaning tank from the tip end of the nozzle Then, the cleaning liquid flows into the nozzle through the slit; and the control device controls to extend the gas in the width direction of the slit from the state in which the cleaning liquid flows into the nozzle by the liquid feeding mechanism. Passing through the slit into the inside of the nozzle.

According to the present invention, the cleaning liquid with the vibration wave is caused to flow into the inside of the nozzle, whereby the fixing material fixed inside the nozzle can be floated. In a state in which the cleaning liquid flows into the inside of the nozzle, the gas flows through the slit in the entire width direction of the slit, and flows into the nozzle through the slit, whereby the gas-liquid interface of the gas and the cleaning liquid can be spread over the entire length of the slit. mobile. As a result, the effect of peeling off the anchor can be brought inside the nozzle, and when the cleaning liquid with the vibration wave is again flowed into the inside of the nozzle, the vibration wave (caused by the vibration wave) can be caused along the flow of the cleaning liquid. The change in the pattern (path) of the cavitation can cause the propagation of the residual vibration wave to be insufficient in the past. As a result, the desired cleaning result can be obtained in a short time.

Further, the coating device further includes: a position changing mechanism that changes a relative position of a liquid surface of the cleaning liquid in the cleaning tank and a height direction of the nozzle tip; and the control device preferably controls the position changing mechanism to The tip end of the nozzle is separated from the liquid surface of the cleaning liquid in a height direction, so that the gas extends over the entire length of the slit in the width direction, and flows into the nozzle through the slit.

At this time, in a state where the tip end of the nozzle is immersed in the cleaning liquid with a vibration wave in the cleaning tank, the position of the nozzle is separated from the liquid surface of the cleaning liquid in the height direction by the position changing mechanism, thereby simply The gas is spread over the entire length of the slit in the width direction, and flows into the inside of the nozzle through the slit.

Further, since the cleaning liquid that has flowed to the inside of the nozzle due to the liquid supply mechanism contains a large amount of gas, the cleaning liquid is returned to the cleaning tank as it is, and then the cleaning liquid with vibration waves is immersed in the cleaning tank at the tip end of the nozzle. In the state where the cleaning liquid flows into the nozzle through the slit, a vibration wave is supplied to the cleaning liquid having an increased amount of dissolved gas. At this time, there is a possibility that the generation of cavitation caused by the vibration wave in the cleaning liquid is hindered by the dissolved gas, and the effect of causing the anchor to float by the action of the holes is weakened.

Therefore, the coating device preferably further includes a cleaning liquid returning portion that allows the cleaning liquid (inflowed from the slit or new) to pass through the flow path of the cleaning liquid flowing from the slit by the liquid supply mechanism. Returning to the cleaning tank; and discharging the flow path, the gas flowing in from the slit is discharged to a region other than the cleaning tank.

At this time, even if the cleaning liquid is returned to the cleaning tank, the amount of dissolved gas in the cleaning liquid in the cleaning tank can be suppressed from increasing, and the effect of preventing the fixing material from floating by the vibration wave can be prevented from being weakened.

According to the present invention, the gas-liquid interface of the gas and the cleaning liquid is moved together over the entire length of the slit in the width direction, so that the effect of stripping the anchor can be brought inside the nozzle, and the cleaning liquid with the vibration wave is again When the inside of the nozzle flows in, the vibration wave (the action of the cavitation caused by the vibration wave) can be changed, and the residual of the vibration wave can be prevented from floating, which can be short. Get the requested cleaning results in time.

1‧‧‧ Coating device

2‧‧‧ platform

3‧‧‧ nozzle

4‧‧‧Drive unit (location change mechanism)

5‧‧‧Control device

6‧‧‧ Cleaning institutions

7‧‧‧Slit

8‧‧‧ device body

9‧‧‧Nozzle front end

10‧‧‧Management

11‧‧‧cleaning tank

11a‧‧‧Solvent tank

11b‧‧‧This cleaning tank

12‧‧‧Oscillation device

12a‧‧‧Vibrator

12b‧‧‧ Controller

13‧‧‧Pump (cleaning liquid return)

14‧‧‧ Waste Department

15‧‧‧Circular flow path

15a‧‧‧ pump

16‧‧‧Degas module

17‧‧‧Heat exchanger

18a, 18b‧‧‧ filter

19a, 19b‧‧‧ three-way valve

20‧‧‧ Lifting device

21‧‧‧Flow

22‧‧‧Draining flow path

22a‧‧‧ gate valve

23‧‧‧ Waste container

24‧‧‧ Container

25, 26‧‧‧ gate valve

27‧‧‧Three-way valve

28‧‧‧cleaning liquid supply container

50‧‧‧Gas Supply Department

50a‧‧‧Connector

A‧‧‧ gas

B1, B2‧‧‧ gas-liquid interface

C1, C2‧‧‧ route

F‧‧‧ fixation

L‧‧‧ cleaning solution

M‧‧·film

P1, P2‧‧‧ piping

R‧‧‧ Foreign objects

S‧‧‧ solvent

W‧‧‧Substrate

Fig. 1 is a schematic view showing an embodiment of a coating apparatus of the present invention.

Fig. 2 is an explanatory view of a nozzle and a cleaning mechanism.

Figure 3 is a flow chart illustrating the cleaning method.

4(A) to (C) are explanatory views of the steps included in the cleaning method.

Fig. 5 is an explanatory view of the nozzle and the cleaning tank, Fig. 5(A) shows the first inflow step, Fig. 5(B) shows the gas inflow step, and Figs. 5(C) and (D) show the second inflow step.

6(A) to (C) are explanatory views for explaining the nozzle and the cleaning tank of the finishing step.

7(A) to 7(C) are explanatory views for explaining another example of the gas inflow mechanism.

[Best Mode for Carrying Out the Invention]

Embodiments of the present invention will be described below based on the drawings.

[Regarding the composition of the coating device]

Fig. 1 is a schematic view showing an embodiment of a coating apparatus 1 of the present invention. The coating device 1 includes a platform 2 on which a substrate (a rectangular single-piece member) W can be placed, a nozzle 3 having a slit 7 formed therein, and a driving device 4 on which the nozzle 3 is mounted so as to be opposite to the nozzle 3 The substrate W on the stage 2 is horizontally moved (moving in the X direction). The member body 8 constitutes the device body 8; according to the device body 8, the driving device 4 horizontally moves the nozzle 3, and ejects the coating liquid from the slit 7 to the substrate W to be coated, whereby the substrate W can be formed. A film (coating film) M formed by the coating liquid. Therefore, the moving direction of the nozzle 3 becomes the coating direction (X direction). Furthermore, the coating device 1 includes a cleaning mechanism 6 for cleaning the nozzles 3. Moreover, the coating apparatus 1 includes the control device 5, the operation of the control device main body 8 and the cleaning mechanism 6, the control device 5 performs the control of the coating operation of ejecting the coating liquid onto the substrate W, and the nozzle 3 by the cleaning mechanism 6. Control of the cleaning action.

The slit 7 formed inside the nozzle 3 is long in the width direction of the nozzle 3 and is open at the tip end (nozzle end) 9 of the nozzle. The width direction of the nozzle 3 is a horizontal direction (Y direction) perpendicular to the coating direction (X direction). The slit 7 is thin in the coating direction and is connected to the manifold 10 formed inside the nozzle 3, and the coating liquid is ejected from the nozzle tip 9 through the manifold 10 and the slit 7. Further, the manifold 10 is also formed in the same width direction as the slit 7. The nozzle tip end 9 (the opening end of the slit 7) in which the slit 7 is opened is horizontal, and is formed linearly across the entire length in the width direction.

The cleaning mechanism 6 includes a cleaning tank 11 for storing the cleaning liquid L of the cleaning nozzle 3; the cleaning tank 11 is disposed near the platform 2. When the coating operation is completed, the driving device 4 horizontally moves the nozzle 3, whereby the nozzle 3 can be positioned above the cleaning tank 11. The drive device 4 has a function of moving the nozzle 3 up and down. By lowering the nozzle 3, the nozzle tip end 9 can be immersed in the cleaning liquid in the cleaning tank 11.

2 is an explanatory view of the nozzle 3 and the cleaning mechanism 6. The cleaning mechanism 6 includes an oscillating device 12 that supplies a vibration wave to the cleaning liquid L in the cleaning tank 11 in addition to the cleaning tank 11 that stores the cleaning liquid L, and a pump 13 that is connected to the nozzle 3 through the pipe P1. system. Further, the cleaning mechanism 6 of the present embodiment includes a waste liquid portion (waste liquid bottle) 14 that is connected to the nozzle 3 through the pipe P2, and the circulation flow path 15 includes a pump that sucks the cleaning liquid L in the cleaning tank 11. 15a, and constitute There is a flow path for returning the sucked cleaning liquid L to the cleaning tank 11; the deaeration module 16 is disposed on the way of the circulation flow path 15 for degassing from the cleaning liquid L; and the heat exchanger 17 is provided. It is used to cool the cleaning liquid on the way of the circulation flow path 15. Further, the circulation flow path 15 is provided with a container 24, filters 18a and 18b, and three-way valves 19a and 19b. Further, the cleaning mechanism 6 includes a lifting device 20 that moves the cleaning tank 11 up and down.

In the state in which the nozzle 13 is immersed in the cleaning liquid L in the cleaning tank 11, the cleaning liquid L in the cleaning tank 11 passes through the slit 7 opened at the nozzle tip end 9, and flows into the nozzle. Temporarily store the pumped liquid.

Further, the cleaning mechanism 6 has a cleaning liquid returning portion for returning the cleaning liquid that has flowed into the inside of the nozzle due to the pump 13 to the washing tank 11 in a countercurrent flow. In the present embodiment, the pump 13 also functions as the cleaning liquid returning portion. In other words, the pump 13 can send the cleaning liquid L to the liquid supply mechanism in both the forward and reverse directions, and by switching the operation state, the cleaning liquid that has flowed into the inside of the nozzle by itself can be returned to the cleaning tank 11 by flowing back. Further, during the operation of the coating operation, the pump 13 may also be used as a supply pump for supplying the coating liquid to the nozzle 3. At this time, the coating liquid storage container (not shown) and the coating liquid supply path that is connected to the pump 13 from the coating liquid storage container are connected to the pump 13 as another pipe.

Further, in the present embodiment, an example in which the pump 13 is used as the liquid supply mechanism is shown, but a liquid supply mechanism that connects a container (not shown) and controls the pressure in the container may be used. That is, the container is connected in place of the pump 13, and the container is coupled to a vacuum source and a pressurized source. The vacuum source is controlled so that the cleaning liquid flows into the inside of the nozzle, and the pressurized source is controlled so that the cleaning liquid inside the nozzle flows back.

Further, the cleaning mechanism 6 further includes a discharge flow path which is branched from a flow path through which the cleaning liquid which flows backward due to the function of the pump (cleaning liquid returning portion) 13 flows, and which is contained in the reverse flow cleaning liquid The gas is discharged to a region other than the cleaning tank 11.

In the present embodiment, the "flow path through which the cleaning liquid flows backward" is as shown in Fig. 4(C), and the pump 13 passes through the manifold 10 inside the nozzle and the slit 7 to the cleaning tank 11. The flow path 21 up to the cleaning liquid L. The discharge flow path 22 is a flow path that branches from the manifold 10 to the waste liquid portion (waste liquid bottle) 14 outside the nozzle 3; and a gate valve (a gas hole valve) 22a is provided in the middle of the flow path. Further, according to Fig. 2, the pipe P2 constitutes a part of the discharge flow path 22.

In Fig. 2, the oscillating device 12 includes a vibrator (ultrasonic vibrator) 12a; and a controller 12b that controls the frequency (oscillation frequency) of the vibrator 12a. The controller 12b is in communication with the control device 5 to function. The oscillating device 12 vibrates the vibrator 12a to impart a vibration wave to the cleaning liquid L in the cleaning tank 11. In the present embodiment, ultrasonic vibration is applied as a vibration wave. In particular, the vibrator is vibrated at a low frequency (20 kHz to 40 kHz) to impart ultrasonic waves. Here, when the frequency is lower than 20 kHz or higher than 40 kHz, it is difficult to find the effect of cavitation required to peel the fixing material which is particularly strongly fixed in a short time, and therefore it is preferably 20 kHz to 40 kHz.

The cleaning tank 11 of the present embodiment has a two-stage type, and includes a solvent tank 11a in which a solvent S for transmitting a vibration wave of the vibrator 12a is stored, and the cleaning tank 11b is provided in the solvent tank 11a, and a cleaning liquid L is stored therein. . When the vibrator 12a vibrates, the ultrasonic wave (vibration wave) propagates to the solvent S, and propagates to the cleaning liquid L through the cleaning tank 11b. On the other hand, the nozzle 12 is immersed in the cleaning liquid L, and the vibrator 12a is vibrated to impart ultrasonic vibration to the cleaning liquid L, and the cleaning liquid L flows into the nozzle 3. In the cleaning liquid L which is violently shaken by the ultrasonic vibration, positive and negative pressures interact with each other, and in the cleaning liquid L, a vacuum cavity (bubble) is generated at the place where the negative pressure acts, and the cavity (bubble) is destroyed by the positive pressure. This phenomenon (cavity action) occurs. The solid matter (dirt) can be floated from the inner surface of the nozzle 3 and the outer surface of the nozzle front end 9 by the effect of the cavitation effect which is generated when the cavity (bubble) is destroyed.

Further, the cleaning tank 11 is of a two-stage type, and the circulation flow path 15 serves as a flow path for sucking the cleaning liquid L in the cleaning tank 11b by the pump 15a and returning the sucked cleaning liquid L to the cleaning tank 11b. Moreover, in order to further enhance the cooling effect of the cleaning liquid L, the solvent S of the solvent tank 11a may be circulated between the solvent tank 11a and the outside of the solvent tank 11a. In this case, in both the cleaning tank 11b and the solvent tank 11a, The cleaning liquid L and the solvent S are circulated.

The cleaning tank 11 may be of a one-stage type. At this time, the vibrator 12a is provided in the washing tank 11 in which the washing liquid L is stored.

The deaeration module 16 has a function of degassing the cleaning liquid supplied to the cleaning tank 11 in advance, and the gas dissolved in the cleaning liquid L can be reduced. If a large amount of gas dissolved in the cleaning liquid L is contained, the generation of cavitation in the cleaning liquid L is hindered by the dissolved gas, so that the cleaning tank is in the cleaning tank. The cleaning effect in 11 is reduced.

[About nozzle cleaning method]

A cleaning method of the nozzle 3 performed by the coating device 1 having the above configuration will be described. Figure 3 is a flow chart illustrating the cleaning method. 4(A) to (C) are explanatory views of the steps included in the cleaning method.

[Washing preparation steps and cleaning action steps]

The coating operation of the nozzle 3 is completed. In order to clean the nozzle 3, the driving device 4 (see Fig. 1) moves the nozzle 3 above the cleaning tank 11 in accordance with the command signal of the control device 5, and thereafter causes the nozzle 3 to descend. The nozzle tip end 9 is immersed in the cleaning liquid L of the cleaning tank 11 (this cleaning tank 11b) for the entire length in the width direction (see FIG. 4(A); cleaning preparation step S1 of FIG. 3).

Here, the nozzle 3 after the completion of the coating operation may be in a state in which the inside of the nozzle is filled with the coating liquid, or may be in a state in which the coating liquid is discharged and is hollow. Further, when the inside of the nozzle is filled with the coating liquid, the cleaning liquid L in the cleaning tank 11 is easily contaminated. Further, when the inside of the nozzle is in a hollow state, the coating liquid remaining inside the nozzle is dried to generate a new anchor. Therefore, the inside of the nozzle should be filled with the state of the cleaning liquid.

Ultrasonic vibration (vibration wave) is supplied to the cleaning liquid L by the vibrator 12a, so that the pump 13 starts the suction operation, and the cleaning liquid L is spread over the entire length of the slit 7 in the longitudinal direction, and passes through the slit 7 to the inside of the nozzle. Flows in (the first inflow step S2 of Fig. 3). That is, ultrasonic vibration is supplied to the cleaning liquid L, and the cleaning liquid L is sucked into the inside of the nozzle. The first inflow step S2 continues for a predetermined period of time.

According to the first inflow step S2, as shown in FIG. 5(A), the cleaning liquid L having ultrasonic vibration (vibration wave) can adhere to the inside of the nozzle (especially the slit 7). F floats out. The floated material F and the cleaning liquid L are sucked into the pump 13 side. In the first inflow step S2, in the slit 7, in the region where a large number of fine bubbles (cavitation) generated by the ultrasonic vibration collide, the fixing material F can be floated and sucked in. The pump 13 side; however, in the area where the fine bubbles (hole action) have little conflict, the solid material F remains.

The difference in the area thus generated is caused by the flow pattern (path) of the cleaning liquid L and the propagation of ultrasonic vibration (cavity caused by ultrasonic waves); if it is generated by ultrasonic vibration The fine bubbles (cavity action) are generated in a certain direction, and the fine bubbles are effectively continuously generated in the region, but in a region where the generation efficiency of the fine bubbles is poor, the state continues. In particular, when the large fixing material F is present in the slit 7 having a very thin shape, the fixing material F cannot be completely floated and remains by ultrasonic vibration. When the fixing material F remains in the slit 7 as described above, the cleaning liquid L does not easily flow due to the resistance of the remaining fixing material F. Therefore, the cleaning liquid L flows away from the fixing material F. As a result, the region to be avoided by the cleaning liquid L is a region where the collision (cavior action) of the fine bubbles is small (the cleaning effect is poor), and the anchor F remains.

Therefore, in the first inflow step S2, in a state where the cleaning liquid L flows into the nozzle by the pump 13, the driving device 4 raises the nozzle 3 in accordance with the command signal of the control device 5, thereby opening the nozzle of the slit 7. The front end 9 is separated from the liquid level of the cleaning liquid L. Therefore, the inside of the nozzle is in an open state, and the gas (atmosphere) flows into the nozzle through the slit 7 from the state in which the cleaning liquid L flows into the nozzle by the pump 13 (refer to FIG. 4(B); FIG. 3; The flow proceeds to step S3). In other words, in the present embodiment, the drive device 4 is a gas inflow mechanism that allows gas to flow in the entire length of the slit 7 in the width direction.

The nozzle tip end 9 (the opening end of the slit 7) in which the slit 7 is opened is horizontal and linearly formed. Therefore, when the cleaning liquid L flows into the nozzle, the nozzle 3 is raised, and the nozzle tip end 9 and the cleaning liquid are made. When the liquid surface of L is separated, the gas flows from the nozzle tip end 9 over the entire length (longitudinal direction) of the slit 7 and flows into the nozzle through the slit 7.

Further, in the present embodiment, the gas system uses the atmosphere, but nitrogen gas or the like may be used, and the gas is not particularly limited.

In the state in which the cleaning liquid L flows into the inside of the nozzle, the gas flows into the nozzle through the slit 7 over the entire length of the slit in the width direction. Therefore, as shown in FIG. 5(B), the gas a and the cleaning liquid L can be made. The gas-liquid interface B1 (the interface from the cleaning liquid L to the gas a) extends over the entire length of the slit 7 in the width direction, and moves toward the manifold 10 side in the same manner.

Further, the gas-liquid interface B1 is formed with a strip-shaped space having a long width direction from the open end of the slit 7 by the gas a; the gas can be carried out by the strip-shaped gas a (space) through the slit 7 It suffices to flow to step S3, and it is sufficient that the time is about several seconds (2 to 3 seconds), and the nozzle tip end 9 can be separated from the liquid surface of the cleaning liquid L at this time.

This gas flows into step S3 to temporarily separate the nozzle tip end 9 from the liquid surface.

After the gas flows into the step S3, the driving device 4 lowers the nozzle 3 according to the command signal of the control device 5, so that the nozzle front end 9 is again immersed in the cleaning liquid L with ultrasonic vibration in the cleaning tank 11, so that the cleaning liquid L extends over the entire length of the slit 7 in the longitudinal direction, and flows into the inside of the nozzle through the slit 7 (see FIG. 4(A); the second inflow step S4 of FIG. 3). The second inflow step S4 continues for a predetermined period of time.

In this way, the cleaning liquid L is again caused to flow into the inside of the nozzle through the slit 7, and as shown in FIGS. 5(C) to 5(D), the cleaning liquid L with ultrasonic vibration is started to be sucked, so that the ultrasonic wave is propagated. The cleaning liquid L (acting by the action of the ultrasonic waves) flows through the slit 7 and changes as compared with the first inflow step S2. That is, the stagnation effect accompanying the movement of the gas-liquid interface B2 (see FIG. 5(C)) from the gas a to the cleaning liquid L causes the sessile F to completely float or the sessile F A part of it floats to shrink the fixing matter F. Therefore, the state in which the cleaning liquid L flows through the slit 7 is changed as compared with the first inflow step. As a result, in the first inflow step S2, a region where the collision of fine bubbles (cavitation) is small is expected, and in the second inflow step S4, it is converted into a region where the fine bubbles (cavitation) conflict frequently.

According to the first inflow step S2, the gas inflow step S3, and the second inflow step S4 described above, the fixing material F adhering to the inside of the nozzle can be quickly and efficiently floated by the cleaning liquid with ultrasonic vibration. In the first inflow step S2, the gas a (see FIG. 5(B)) is spread over the entire length of the slit 7 in the state in which the cleaning liquid L flows into the nozzle, and flows into the nozzle through the slit 7 (gas inflow) In step S3), the gas a liquid interface B1 of the gas a and the cleaning liquid L can be moved in the same manner throughout the width direction of the slit 7 in the same manner. Further, the cleaning liquid L is again passed over the entire length of the slit 7 in the width direction, and flows into the nozzle through the slit 7 (see FIGS. 5(C) and (D); second inflow step S4), whereby the gas a and The gas-liquid interface B2 of the cleaning liquid L moves over the entire length of the slit 7 in the width direction.

As a result, the effect of peeling off the fixing material F can be brought about inside the nozzle, and when the cleaning liquid L having the vibration wave is again flown into the inside of the nozzle in the second inflow step S4, the cleaning liquid L flows. The state (path) and the state (path) of the propagation of the ultrasonic wave (cavity caused by the ultrasonic wave) are changed, and the residual of the vibration wave is insufficient and the residual solid material floats.

In addition, when the first inflow step S2 is shifted to the gas inflow step S3, the cleaning liquid that has flowed to the inside of the nozzle contains a large amount of gas. Therefore, when the cleaning liquid is returned to the cleaning tank 11 as it is, the first inflow is performed again. In step S2, a vibration wave is supplied to the cleaning liquid L in which the amount of dissolved gas is increased. At this time, there is a possibility that the generation of cavitation in the cleaning liquid L is hindered by the dissolved gas, and the effect of causing the fixing material F to float by ultrasonic vibration is weakened.

Therefore, when the second inflow step S4 is completed, the control unit 5 switches the operation state of the pump 13 so that the cleaning liquid that has flowed into the inside of the nozzle flows back in the first inflow step S2 and the second inflow step S4 (refer to Figure 4 (C)). At this time, the gate valve (the vent valve 22a) is switched to the open state, and the gas contained in the cleaning liquid passes through a slit different from the slit 7 from the way of returning the cleaning liquid to the flow path 21 of the cleaning tank 11 in a countercurrent flow. The flow path 22 is discharged and discharged (the gas discharge step S5 of Fig. 3). Further, the gate valve 22a is in the open state only in the gas discharge step S5, and is in the closed state in the other steps.

This gas discharge step S5 is performed until the pump 13 completely discharges the sucked washing liquid. A part of the washing liquid discharged from the pump 13 flows to the waste liquid portion 14 via the discharge flow path 22.

The slit 7 included in the flow path 21 is very thin, and the flow path of the discharge flow path 22 is much larger than the cross section; the resistance of the cleaning liquid flowing back to the cleaning tank 11 through the slit 7 is greater than the flow through the discharge flow. Resistance of the cleaning fluid of the road 22. Further, the branching portion of the discharge flow path 22 in the manifold 10 is located at the upper portion of the manifold 10. Therefore, the gas contained in the cleaning liquid that is caught in the counterflow by the manifold 10 can flow the captured gas together with a part of the cleaning liquid to the discharge flow path 22. The gas is discharged to the outside through the gate valve 22a.

According to the gas discharge step S5, even if the cleaning liquid that has flowed to the inside of the nozzle due to the suction of the pump 13 flows back to the cleaning tank 11, the amount of dissolved gas in the cleaning liquid L in the cleaning tank 11 can be suppressed from increasing. Even if the first inflow step S2 is performed later, the effect of causing the anchor F to float by the ultrasonic vibration can be prevented from being weakened.

As described above, the first gas inflow step S2 to the gas discharge step S5 is a cycle of the cleaning operation step; in the cleaning operation step, the plurality of cycles may be repeatedly performed. That is, the control device 5 sets the number of times the cleaning operation step is performed; and repeats the cleaning operation step until the Until the number of times (when the determination step S6 of Fig. 3 is No). When the execution of the set number of times is completed (when the determination step S6 of Fig. 3 is Yes), the process proceeds to the finishing step S7.

[finishing step (1)]

Although the coating apparatus 1 of FIG. 1 is provided in the clean room, for example, fine metal dust may be generated by driving of the driving device 4 or the like, and the like may be dropped in the clean room (atmosphere) and dropped to The tank 11 is cleaned (this washing tank 11b). Then, the metal dust is present in the cleaning tank 11 as the foreign matter R in the cleaning tank 11. When the foreign matter R is present in the cleaning tank 11, the foreign matter R in the cleaning tank 11 is floated by supplying the vibration wave according to the first inflow step and the second inflow step. Therefore, the foreign matter R is combined with the cleaning liquid L. It is sucked into the inner side of the nozzle. Therefore, the finishing step S7 of discharging the foreign matter R from the inside of the nozzle is performed.

As shown in Fig. 6(A), in the state in which the nozzle tip 9 is immersed in the cleaning liquid L of the cleaning tank 11, the pump 13 is caused to flow into the inside of the nozzle in the first inflow step S2 and the second inflow step S4. The cleaning liquid flows countercurrently, thereby discharging the cleaning tank 11 (finishing step S7 of Fig. 3). At this time, the gate valve 22a is in a closed state.

In the finishing step S7, the ultrasonic wave vibration is applied to the cleaning liquid L of the cleaning tank 11 by the oscillating device 12, and the driving device 4 raises the nozzle 3 in accordance with the command signal of the control device 5 from the middle of the step. The nozzle tip end 9 of the cleaning liquid L immersed in the cleaning tank 11 is separated from the liquid surface of the cleaning liquid L (see FIG. 6(B)). In the operation of separating the nozzle tip end 9 from the liquid surface of the cleaning liquid L, the cleaning liquid on the inside of the nozzle is discharged.

At this time, even if the foreign matter R existing in the cleaning tank 11 is sucked into the inside of the nozzle together with the cleaning liquid L by the first inflow step and the second inflow step, the cleaning liquid L is ejected toward the cleaning tank 11, The foreign matter R can be ejected from the inside of the nozzle. In addition, ultrasonic vibration is applied to the cleaning liquid L of the cleaning tank 11 to maintain the original state, and the nozzle tip end 9 immersed in the cleaning liquid in the cleaning tank 11 is separated from the liquid surface of the cleaning liquid L, so that the discharge can be temporarily prevented. The foreign matter R is again attached to the nozzle front end 9.

Further, in the step S7, the ultrasonic vibration is supplied to the cleaning liquid L. Therefore, the foreign matter R blocked inside the nozzle can be floated by the ultrasonic vibration to lower the inner wall surface of the slit 7. Friction resistance, in this state, spitting the cleaning liquid, thereby preventing the foreign matter R from being formed It adheres to the inside of the nozzle and is effectively discharged.

[finishing step (2)]

Another example of the finishing step S7 will be described. When the foreign matter R existing in the cleaning tank 11 floats in the slit 7 due to ultrasonic vibration and easily enters the inside of the nozzle (specific gravity, size, etc.), it is easy to follow the first inflow step and the second inflow step. The foreign matter R is sucked into the inside of the nozzle together with the cleaning liquid. In this case, the following finishing step S7 should be employed.

As shown in Fig. 6(A), in the state in which the nozzle tip 9 is immersed in the cleaning liquid L of the cleaning tank 11, the pump 13 is caused to flow into the inside of the nozzle in the first inflow step S2 and the second inflow step S4. The cleaning liquid flows countercurrently, thereby discharging the cleaning tank 11 (finishing step S7 of Fig. 3). At this time, the gate valve 22a is in a closed state.

In the finishing step S7, ultrasonic wave vibration is applied to the cleaning liquid L in the cleaning tank 11 while the cleaning liquid is being flowed back to the cleaning tank 11 (see FIG. 6(C)).

At this time, even if the foreign matter R existing in the cleaning tank 11 is sucked into the inside of the nozzle together with the cleaning liquid L by the first inflow step and the second inflow step, the cleaning liquid L can be ejected toward the cleaning tank 11 The foreign matter R is ejected from the inside of the nozzle. In addition, when the cleaning liquid L is caused to flow back to the cleaning tank 11, the ultrasonic vibration (vibration wave) is applied to the cleaning liquid L in the cleaning tank 11, so that the foreign matter R can be prevented from floating due to ultrasonic vibration. The inside of the tank 11 is cleaned and invaded into the inside of the nozzle.

When the above finishing step (1 or 2) is completed, the driving device 4 (refer to FIG. 1) moves the nozzle 3 toward the device body 8 side according to the command signal of the control device 5, and is ready to start: for holding on the platform 2 The upper substrate W ejects the coating liquid to perform a coating operation (coating preparation step S8). Further, in the finishing step (1 or 2), the cleaning liquid is ejected toward the cleaning tank 11, but the cleaning liquid is not only the cleaning liquid sucked into the inside of the nozzle but also the new one supplied to the nozzle 3. Cleaning fluid.

Further, in each of the above steps, the frequency of the vibrator 12a of the oscillating device 12 is such that a low frequency band (20 kHz to 40 kHz) capable of obtaining a hole having a high cleaning effect can be generated. Based on the low frequency Since the ultrasonic vibration is generated to perform the first inflow step S2 and the second inflow step S4, the cleaning effect of the nozzle tip end 9 can be further improved as compared with the frequency at the frequency other than the frequency band.

However, when the vibrator 12a is vibrated at a low frequency and ultrasonic vibration is generated to perform the first inflow step S2 and the second inflow step S4, the temperature of the cleaning liquid L tends to rise. On the other hand, in the determination step S6 of FIG. 3 (No in the determination step S6), the first inflow step S2 is performed again, and when the cleaning liquid L having the temperature rise flows into the nozzle inner side, the temperature of the nozzle 3 also rises. At this time, the thermal expansion of the nozzle 3 changes the size of the slit 7, and if the nozzle 3 is used for the coating operation immediately, the coating quality may be affected. Therefore, it is necessary to stop the work until the temperature of the cleaning liquid L of the washing tank 11 drops to a predetermined temperature, resulting in waste of time.

Therefore, before the first inflow step S2 is performed again, it is preferable to replace step S9 (see FIG. 3) in which at least a part of the cleaning liquid L of the washing tank 11 is replaced. According to this step S9, it is possible to prevent the first inflow step S2 from being performed again by the cleaning liquid L whose temperature has risen. A specific example of replacing step S9 will be described. As a first method, in FIG. 2, the cleaning liquid sucked by the pump 15a is collected as a waste liquid in the container 23 by the three-way valve 19a. On the other hand, a new cleaning liquid in which the cleaning liquid as the waste liquid is replaced is supplied through the three-way valve 19b. Further, in the present embodiment, the new cleaning liquid is supplied to the cleaning tank 11 via the deaeration module 16. As described above, a part of the used cleaning liquid L of the cleaning tank 11 can be replaced with a new cleaning liquid, and the temperature of the cleaning liquid L of the cleaning tank 11 can be prevented from rising.

As a second method, the cleaning liquid sucked by the pump 15a is sent to the heat exchanger 17 through the three-way valve 19a, and is cooled. The cooled cleaning liquid is sent to the washing tank 11 through the circulation flow path 15. Further, the cleaning liquid circulated in the present embodiment is returned to the cleaning tank 11 via the deaeration module 16. As described above, one portion of the used cleaning liquid L of the cleaning tank 11 can be circulated, heat exchange is performed in the middle thereof, and the cleaning tank 11 is replaced with the cooled cleaning liquid L.

Further, the replacement of the cleaning liquid L may be performed in each of the first inflow step S2, the gas inflow step S3, and the second inflow step S4, or after each step. When it is carried out in each step, it is a nozzle cleaning method which comprises at least a part of the cleaning liquid L of the cleaning tank 11 during the period in which the ultrasonic vibrator 12a is vibrated at a low frequency (20 kHz to 40 kHz) to generate ultrasonic waves. Steps to replace (continuous replacement steps).

As described above, according to the nozzle cleaning method of the present embodiment, as shown in FIG. 5(B), the gas-liquid interface B1 of the gas a and the cleaning liquid L is moved upward along the entire length of the slit 7 in the width direction; As shown in Fig. 5(C), the gas-liquid interface B2 of the gas a and the cleaning liquid L are moved upward together over the entire length of the slit 7 in the width direction, whereby the effect of peeling off the anchor F is brought inside the nozzle. When the cleaning liquid L having the vibration wave flows into the inside of the nozzle again, the flow pattern (path) of the cleaning liquid L and the ultrasonic wave (cavity action by ultrasonic waves) are propagated. (path) changes. Therefore, the propagation of the ultrasonic vibration in the past is insufficient and the residual solid material can be made to float. The cleaning liquid L with the vibration wave is again flowed into the inside of the nozzle, whereby the solid matter remaining in the past can be cleaned. As a result, the desired cleaning result can be obtained in a short time.

Further, since the cleaning time can be a short period of time, the time for applying the ultrasonic vibration to the cleaning liquid L is short, and the heat generation of the nozzle 3 due to the ultrasonic vibration can be suppressed, and the coating operation can be started quickly.

Further, the vibrator 12a is constituted by a hollow member, and the refrigerant may pass through the inside thereof. It is preferable to provide a connection port for supplying a refrigerant (for example, nitrogen gas) to the hollow vibrator 12a, and to allow the refrigerant to flow into the vibrator 12a through the connection port so that the vibrator 12a and the cleaning liquid L do not accumulate heat.

Further, the coating apparatus and the nozzle cleaning method of the present invention are not limited to the illustrated ones, and may be other forms within the scope of the present invention.

In the above-described embodiment, the position changing mechanism is described in the driving device 4 that moves the nozzle 3 up and down. In order to separate the liquid surface of the cleaning liquid L of the cleaning tank 11 from the nozzle tip end 9 in the gas inflow step, the position changing mechanism The relative position of the liquid surface to the height direction of the nozzle tip end 9 is changed, but it may be other. The lifting device 20 (see FIG. 2) for raising and lowering the cleaning tank 11 may be used as the position changing mechanism. Alternatively, although the relative position between the nozzle tip end 9 and the cleaning tank 11 in the height direction does not change, the liquid level of the cleaning liquid L may be lowered during the gas inflow step, and thereafter the liquid level may be raised. This is achieved by discharging and supplying the cleaning liquid L to the cleaning tank 11.

In the gas inflow step, the gas is passed through the slit in the width direction (longitudinal direction) of the slit 7 from the state in which the cleaning liquid L in the cleaning tank 11 flows into the nozzle by the pump 13. 7 Into the inside of the nozzle, in order to achieve this, in the above embodiment, the height of the nozzle tip 9 with respect to the liquid surface of the cleaning liquid L is changed. Although the above is explained, it may be other. For example, as shown in FIG. 7(A), a gas supply unit 50 having a port 50a connectable to the nozzle tip end 9 is provided in the cleaning tank 11b, and gas is supplied from the outside of the washing tank 11 to the gas supply unit 50. . As shown in FIG. 7(B), the nozzle 3 is lowered by the driving device 4 (see FIG. 1), whereby the nozzle tip end 9 is connected to the port 50a, and gas flows from the gas supply portion 50 through the slit 7 into the nozzle. . As shown in Fig. 7(C), the port 50a is provided across the entire length of the slit 7 (nozzle tip 9) in the width direction, and allows gas to flow in the entire width direction of the slit 7.

As described above, in a state in which the cleaning liquid L flows into the inside of the nozzle (Fig. 7(A)), the gas is allowed to flow through the slit 7 through the slit 7 in the width direction of the slit 7 (Fig. 7(B)). The purpose is to lower the nozzle 3 by the drive unit 4, which is carried out by the control of the control unit 5. At this time, the drive device 4 and the gas supply unit 50 are gas inflow mechanisms that allow gas to flow into the inside of the nozzle over the entire length of the slit 7 in the width direction.

Further, in the above-described embodiment, the cleaning liquid L that has flowed into the cleaning tank 11 inside the nozzle is returned to the cleaning tank 11 in the gas discharge step and the finishing step, but the cleaning liquid L is caused to flow. After the inside of the nozzle, the new cleaning liquid can be returned to the cleaning tank 11.

For example, as shown in Fig. 2, a gate valve 25 is provided on the pipe P1 (between the nozzle 3 and the pump 13), and a three-way valve 27 is provided between the pump 13 and the cleaning liquid supply container 28; the output of the three-way valve 27 One of them is connected to the waste liquid container 23. Further, a gate valve 26 is provided between the three-way valve 27 and the pump 13. According to this configuration, it is possible to suppress the gas contained in the cleaning liquid L (the gas sucked from the slit 7 in the gas inflow step) from returning to the cleaning tank 11.

That is, the gate valve 25 is in the open state, and the gate valve 26 is in the closed state, so that the pump 13 performs the pumping operation, whereby the cleaning liquid containing the gas inside the nozzle is sucked into the pump 13 through the pipe P1. When the gate valve 25 is closed and the gate valve 26 is opened, the three-way valve 27 is routed from the pump 13 side to the container 23 (C1 route in FIG. 2), so that the pump 13 performs a discharge operation, thereby pumping 13 The cleaning liquid is discharged to the container 23. That is, the gas flowing in the gas inflow step can be self-filled from the flow path (the flow path from the slit 7 to the pump 13) of the cleaning liquid flowing from the slit 7 into the pump 13, and the cleaning liquid The flow path (discharge flow path) from the pump 13 to the container 23 is discharged to the same Container 23.

When the gate valve 25 is closed and the gate valve 26 is opened, the three-way valve 27 is switched to a route from the cleaning liquid supply container 28 to the pump 13 side (C2 route in FIG. 2), so that the pump 13 performs a suction operation. The new cleaning liquid in the cleaning liquid supply container 28 is sucked into the pump 13. When the gate valve 25 is opened and the gate valve 26 is closed, the pump 13 is caused to perform a discharge operation, whereby the new cleaning liquid sucked into the pump 13 is supplied to the inside of the nozzle through the pipe P1. Further, the pump 13 is continuously operated to return the new cleaning liquid to the cleaning tank 11 through the slit 7. Therefore, it is possible to suppress the gas introduced into the cleaning liquid from the gas inflow step and return it to the cleaning tank 11; it is possible to suppress the propagation of the vibration wave in the cleaning liquid in the cleaning tank 11 by the dissolved gas, and to fix the fixation by the vibration wave. The effect of floating out is weakened. At this time, it is also preferable to provide the deaeration module 16 between the cleaning liquid supply container 28 and the pump 13.

Further, in the above embodiment, the step of replacing the cleaning liquid is to perform the first inflow step after the first inflow step and the second inflow step, and to clean the tank 11 before the first inflow step is performed again. The case where at least a part of the cleaning liquid L is replaced is described, but the replacement step may be continuously performed in any step. Specifically, in each step, the replacement step is often performed while the ultrasonic vibrator 12a is vibrated at a low frequency to generate a vibration wave. At this time, the cleaning liquid can be circulated frequently.

Depending on the temperature of the cleaning liquid, the temperature of the nozzle 3 may rise only by immersing the nozzle 3 in the cleaning liquid. At this time, the thermal expansion of the nozzle 3 changes the size of the slit 7, and thus it is possible to affect the coating quality. Therefore, when the ultrasonic vibrator 12a is actuated at a low frequency, the cleaning liquid is often circulated, so that the cleaning liquid is often cooled. Therefore, the temperature rise of the cleaning liquid can be suppressed, the temperature rise of the nozzle 3 can be suppressed, and the influence on the coating quality can be suppressed.

Regarding the cleaning method of the nozzle, the description of the invention will be made.

The problem of this reference invention is that it is thought that a vibrator is provided at the bottom of the cleaning tank for storing the cleaning liquid and immersing the nozzle tip in the cleaning liquid, in order to bring the position of the ultrasonic vibration to the cleaning liquid close to the nozzle front end. The vibration wave (ultrasonic vibration) is applied to the cleaning liquid by the vibrator to clean the nozzle; however, the vibration wave is supplied to the cleaning liquid in the cleaning tank, so that foreign matter may float in the cleaning tank. During the cleaning of the nozzle, the floating foreign matter intrudes into the inside of the nozzle.

Therefore, the reference invention relates to a nozzle cleaning method in which a nozzle is formed in a slit which is long in the width direction and opened at the front end; the nozzle cleaning method further comprises: a cleaning step of immersing the tip of the nozzle in the cleaning tank In the cleaning liquid having a vibration wave, the cleaning liquid flows through the slit to perform cleaning inside the nozzle; and the finishing step is performed in the cleaning step in a state where the nozzle tip is immersed in the cleaning liquid of the cleaning tank After the inside of the nozzle is cleaned, the cleaning liquid is ejected from the slit to the cleaning tank. In the finishing step, a vibration wave is applied to the cleaning liquid of the cleaning tank to maintain the original state, and the cleaning is performed. The tip end of the nozzle in the cleaning liquid of the tank is separated from the liquid surface of the cleaning liquid.

According to the reference aspect of the invention, even in the cleaning step, the foreign matter floating in the cleaning tank intrudes into the inside of the nozzle and adheres to the liquid contact surface inside the nozzle, and the cleaning liquid is ejected to the cleaning tank by the finishing step, whereby the adhesion can be caused. The foreign matter on the liquid contact surface inside the nozzle floats due to the vibration wave, and is ejected from the inside of the nozzle. Further, by applying a vibration wave to the cleaning liquid in the cleaning tank and maintaining the original state, the nozzle tip of the cleaning liquid immersed in the cleaning tank is separated from the liquid surface of the cleaning liquid, thereby preventing foreign matter floating in the cleaning tank from being again Attached to the inside of the nozzle and the front end of the nozzle. Therefore, it is possible to quickly transfer from the washing step to the coating operation.

Further, regarding the cleaning method of the nozzle, another description of the invention will be made.

The problem of this reference invention is that it is thought that a vibrator is provided at the bottom of the cleaning tank for storing the cleaning liquid and immersing the nozzle tip in the cleaning liquid, in order to bring the position of the ultrasonic vibration to the cleaning liquid close to the nozzle front end. The vibrating device applies ultrasonic waves to the cleaning liquid (ultrasonic vibration) to clean the nozzle. However, in particular, the foreign matter floating in the cleaning tank floats in the slit due to ultrasonic vibration, and easily invades the nozzle. In the internal form (specific gravity, size, etc.), the foreign matter floating in the washing tank may intrude and adhere to the inside of the nozzle.

Therefore, the reference invention relates to a nozzle cleaning method in which a nozzle is formed in a slit which is long in the width direction and opened at the front end; the nozzle cleaning method further comprises: a cleaning step of immersing the tip of the nozzle in the cleaning tank In the cleaning liquid having a vibration wave, the cleaning liquid flows through the slit to perform cleaning inside the nozzle; In the finishing step, after the nozzle tip is immersed in the cleaning liquid of the cleaning tank, after the inside of the nozzle is cleaned in the cleaning step, the cleaning liquid is ejected from the slit to the cleaning tank; In the processing step, the vibration wave is not applied to the cleaning liquid in the cleaning tank while the cleaning liquid is being ejected to the cleaning tank.

According to the reference, in the cleaning step, the foreign matter floating in the washing tank intrudes into the inside of the nozzle, and the cleaning liquid is ejected to the washing tank by the finishing step, whereby the foreign matter can be easily ejected from the inside of the nozzle. . Furthermore, at this time, ultrasonic waves can be applied to prevent foreign matter from adhering to the tip end of the nozzle. Further, while the cleaning liquid is ejected into the cleaning tank, the vibration wave is prevented from being applied to the cleaning liquid in the cleaning tank, so that foreign matter in the cleaning tank can be prevented from floating in the cleaning tank due to vibration waves, and foreign matter can be prevented from adhering to the nozzle tip. . Therefore, it is possible to quickly transfer from the washing step to the coating operation.

Further, the cleaning steps in the respective reference inventions are the same as the cleaning operation steps including the first inflow step, the gas inflow step, and the second inflow step described in the above embodiment; For the cleaning step and the finishing step, each of the cleaning operation step and the finishing step described in the nozzle cleaning method of each of the above embodiments can be applied.

3‧‧‧ nozzle

4‧‧‧Drive unit (location change mechanism)

5‧‧‧Control device

6‧‧‧ Cleaning institutions

7‧‧‧Slit

9‧‧‧Nozzle front end

10‧‧‧Management

11‧‧‧cleaning tank

11a‧‧‧Solvent tank

11b‧‧‧This cleaning tank

12‧‧‧Oscillation device

12a‧‧‧Vibrator

12b‧‧‧ Controller

13‧‧‧Pump (cleaning liquid return)

14‧‧‧ Waste Department

15‧‧‧Circular flow path

15a‧‧‧ pump

16‧‧‧Degas module

17‧‧‧Heat exchanger

18a, 18b‧‧‧ filter

19a, 19b‧‧‧ three-way valve

20‧‧‧ Lifting device

22‧‧‧Draining flow path

22a‧‧‧ gate valve

23‧‧‧ Waste container

24‧‧‧ Container

25, 26‧‧‧ gate valve

27‧‧‧Three-way valve

28‧‧‧cleaning liquid supply container

C1, C2‧‧‧ route

L‧‧‧ cleaning solution

P1, P2‧‧‧ piping

S‧‧‧ solvent

Claims (10)

A nozzle cleaning method, wherein the nozzle is formed with a slit which is long in a width direction and opens at a front end; the nozzle cleaning method is characterized by comprising: a first inflow step for immersing the tip of the nozzle in the cleaning tank In the cleaning liquid of the vibration wave, the cleaning liquid flows into the nozzle through the slit; and in the gas inflow step, the gas is spread over the slit in a state in which the cleaning liquid flows into the nozzle in the first inflow step. The entire length of the direction flows into the nozzle through the slit; and in the second inflow step, after the gas inflow step, the tip end of the nozzle is immersed in the cleaning liquid with vibration waves in the cleaning tank to make the cleaning liquid The slit flows into the inside of the nozzle. The nozzle cleaning method according to claim 1, wherein in the gas inflow step, the tip end of the nozzle is separated from the liquid surface of the cleaning liquid, so that the gas passes through the slit in the width direction of the slit, and the slit passes through the slit. Flow into the inside of the nozzle. The nozzle cleaning method according to claim 1 or 2, further comprising: a gas discharge step of filling the cleaning liquid through the cleaning liquid flowing from the slit in the first inflow step and the second inflow step The flow path is returned to the cleaning tank, and the gas flowing in the gas inflow step is discharged from the flow path through the discharge flow path different from the slit. The nozzle cleaning method according to any one of claims 1 to 3, further comprising: a finishing step of immersing the cleaning liquid in the cleaning tank at a tip end of the nozzle, in the first inflow step and the After the cleaning liquid flows into the inside of the nozzle in one or both of the second inflow steps, the cleaning liquid is ejected from the slit to the cleaning tank; in the finishing step, the cleaning liquid of the cleaning tank is vibrated. The wave is maintained in this state, and the tip end of the nozzle immersed in the cleaning liquid of the cleaning tank is separated from the liquid surface of the cleaning liquid. The nozzle cleaning method according to any one of claims 1 to 3, further comprising: a finishing step of immersing the cleaning liquid in the cleaning tank at a tip end of the nozzle, in the first inflow step and the a second inflow step in which one or both of the cleaning liquid flows into the nozzle After the inner side, the cleaning liquid is ejected from the slit to the cleaning tank. In the finishing step, the vibration wave is applied to the cleaning liquid in the cleaning tank while the cleaning liquid is being ejected to the cleaning tank. The nozzle cleaning method according to any one of claims 1 to 5, wherein the first inflow step and the second inflow step are performed by vibrating the ultrasonic vibrator at a low frequency to generate the vibration wave. Thereafter, when the first inflow step is performed again, the step of replacing at least a part of the cleaning liquid of the cleaning tank is further included before the first inflow step is performed again. The nozzle cleaning method according to any one of claims 1 to 6, further comprising: a continuous replacement step of vibrating the ultrasonic vibrator at a low frequency to cause the vibration wave to be generated, the cleaning tank Replace at least a portion of the cleaning fluid. A coating apparatus comprising: a device body having a nozzle having a slit formed in a wide direction in the width direction and opening at a front end thereof, and spraying a coating liquid from the slit to the substrate; And a cleaning mechanism for cleaning the nozzle; the coating device is characterized in that: the cleaning mechanism comprises: a cleaning tank for storing the cleaning liquid; and an oscillating device for imparting a vibration wave to the cleaning liquid in the cleaning tank; The liquid supply mechanism is configured such that the nozzle tip is immersed in the cleaning liquid to which the vibration wave is applied in the cleaning tank, and the cleaning liquid flows into the nozzle through the slit; and the control device controls the The liquid supply mechanism causes the cleaning liquid to flow into the inside of the nozzle, and allows the gas to flow over the entire length of the slit in the width direction, and flows into the nozzle through the slit. The coating device of claim 8 , further comprising: a position changing mechanism that changes a relative position of the liquid level of the cleaning liquid in the cleaning tank and the front end of the nozzle in a height direction; The control device controls the position changing mechanism to separate the tip end of the nozzle from the liquid level of the cleaning liquid in the height direction, so that the gas flows through the slit in the width direction of the slit and flows into the nozzle through the slit. The coating device of claim 8 or 9, further comprising: a cleaning liquid returning portion, wherein the cleaning liquid is returned to the cleaning liquid through a flow path filled with the cleaning liquid flowing from the slit by the liquid feeding mechanism The cleaning tank and the discharge flow path discharge the gas flowing in from the slit to a region other than the cleaning tank.