JP2016182540A - Liquid ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge device in which a liquid is prevented quickly from being dropped from a discharge opening at a use point without using excess energy after a discharge of the liquid is stopped.SOLUTION: The liquid discharge device for discharging a predetermined amount of the liquid includes: a supply flow passage 2 which is connected to a liquid supplying means 1; a discharge flow passage 3 having the discharge opening 13 for discharging the liquid; a first valve 5 for starting or stopping circulation of the liquid between the supply flow passage and the discharge flow passage; a drain flow passage 4 having a drain opening 14 for draining the liquid; and a second valve 6 for starting or stopping circulation of the liquid between the discharge flow passage and the drain flow passage. The discharge opening is disposed at the position higher than that of the drain opening. When the first valve stops the circulation of the liquid between the supply flow passage and the discharge flow passage and the second valve starts the circulation of the liquid between the discharge flow passage and the drain flow passage, the liquid, with which the inside of the discharge flow passage is filled so that the liquid level reaches the discharge opening, is made to flow to the side of the drain opening by means of a siphon effect.SELECTED DRAWING: Figure 1C

Description

  The present invention relates to a liquid ejecting apparatus for ejecting a liquid onto an object, and more particularly to a liquid ejecting apparatus that can prevent dripping from an ejection opening that occurs after stopping the ejection of a liquid.

  2. Description of the Related Art Conventionally, a liquid ejection apparatus shown in FIG. 6 is known as a liquid ejection apparatus that can prevent dripping after the liquid ejection is stopped (see, for example, Patent Document 1). As shown in FIG. 6, this liquid ejection apparatus is a liquid ejection apparatus having a liquid supply unit 1001, a liquid use point 1002, and a supply piping unit 1003 for circulating liquid from the supply unit 1001 to the use point 1002. is there. The supply piping unit 1003 supplies the liquid to the use point 1002 side branched by the main piping unit 1004 for circulating the liquid supplied from the supply unit 1001 side, the aspirator 1005 connected to the main piping unit 1004, and the aspirator 1005. A use-side piping unit 1006 and a sub-pipe unit 1007, and a valve 1008 connected to the sub-pipe unit 1007 and having an opening / closing function are provided. A main pipe portion 1004 and a sub pipe portion 1007 are connected to the main flow path side of the aspirator 1005, and a use side pipe portion 1006 is connected to the suction flow path side of the aspirator 1005.

JP 2013-59735 A

  However, in the conventional liquid discharge device, the liquid is circulated to the main flow path side of the aspirator 1005 to depressurize the inside of the aspirator 1005, and the liquid in the use point side piping unit 1006 is sucked into the sub piping unit 1007, thereby allowing the use. The dripping from the discharge opening at the point 1002 is prevented. Therefore, in order to prevent dripping, it is necessary to continue pumping the liquid to the aspirator 1005 using a pumping facility such as a pump even after the discharge of the liquid is stopped, and extra energy is required to operate the pumping facility. Is required. Moreover, since the dripping is prevented by the flow of the reduced pressure in the aspirator 1005, in order to effectively prevent the dripping, it is necessary to reduce the pressure loss of the use point side piping unit 1006. The pipe diameter and pipe length of the point side pipe part 1006, the presence or absence of a bent part, and the like are limited, and the degree of freedom in design is reduced. Also, a time lag occurs between the opening of the valve 1008 and the time when the pressure inside the aspirator 1005 is sufficiently reduced. Until the inside of the aspirator 1005 is sufficiently depressurized, the liquid is discharged to the use point 1002 by inertia. Therefore, even if the valve 1008 is opened, the dripping cannot be prevented promptly.

  An object of the present invention has been made in view of the above-described problems of the prior art, and relates to a liquid ejection apparatus for ejecting a liquid onto an object. It is an object of the present invention to provide a liquid discharge apparatus capable of preventing dripping from a discharge opening at a use point immediately after stopping the operation.

  According to the first aspect of the present invention, in the apparatus for discharging a predetermined amount of liquid, the liquid supply means for pumping the liquid, the supply flow path connected to the liquid supply means, and the discharge opening for discharging the liquid are provided. A discharge channel, a first valve connected to the supply channel and the discharge channel, and opening or blocking the flow of the liquid between the supply channel and the discharge channel; and discharging the liquid A discharge flow path having a discharge opening, and a second valve connected to the discharge flow path and the discharge flow path to open or block the flow of the liquid between the discharge flow path and the discharge flow path. The discharge opening is disposed at a position higher than the discharge opening, the first valve blocks the flow of the liquid between the supply flow path and the discharge flow path, and the second valve is The flow of the liquid between the discharge channel and the discharge channel When released, a liquid discharge device is provided in which the liquid filled in the discharge flow path so as to have a liquid level in the discharge opening flows to the discharge opening side by a siphon effect. .

  That is, in the first aspect of the invention, since the liquid filled in the discharge flow path so as to have the liquid level at the discharge opening is discharged from the discharge opening by the siphon effect, the discharge of the liquid is stopped. Liquid dripping from the discharge opening can be prevented quickly. Moreover, since it is not necessary to depressurize the discharge flow path side in order to prevent dripping, there is no need for equipment (for example, a pump) for depressurizing the discharge flow path side, and the capital investment burden can be reduced. it can. Moreover, since equipment such as a pump is not required, energy for operating those equipment can be omitted, and the energy burden can be reduced. In addition, since it is not necessary to reduce the pressure on the discharge flow path side to prevent dripping, the effect of pressure loss on dripping prevention can be reduced, and the pipe diameter, pipe length, and bending of the discharge flow path can be reduced. It is possible to relax restrictions such as the presence or absence of parts and improve the degree of freedom of design.

  According to the second aspect of the present invention, the discharge channel is provided with a discharge channel inlet side opening connected to the second valve at the end, and the discharge channel inlet side opening is more than the discharge opening. The liquid ejection device according to claim 1, wherein the liquid ejection device is provided at a lower position.

  That is, in the invention of claim 2, the siphon effect can be exhibited even when the discharge channel is not full, and the dripping from the discharge opening can be more reliably prevented.

  According to a third aspect of the present invention, the first valve and the second valve are integrally coupled and arranged as a single manifold valve. A liquid ejection device is provided.

  That is, in the invention of claim 3, the space required for installing the first valve and the second valve can be reduced.

  According to the invention of claim 4, the manifold valve is a valve main body, and is a first valve side valve chamber, a second valve side valve chamber, and a communication channel side formed in the first valve side valve chamber. A communication channel connected to the first opening and the communication channel side second opening formed in the second valve side valve chamber to communicate the first valve side valve chamber and the second valve side valve chamber; , An inlet channel side opening formed in the first valve side valve chamber and an inlet channel connected to the supply channel, an outlet channel side opening formed in the second valve side valve chamber, and the discharge flow A valve body comprising: an outlet flow path connected to the passage; a branch flow path side opening formed in the second valve side valve chamber; and a branch flow path connected to the discharge flow path; and the inlet flow A first valve body that opens and closes a road-side opening or the communication channel side first opening; and a first valve body that drives the first valve body. A second valve body that opens and closes the branch channel side opening without blocking a drive unit, the communication channel, and the communication state between the second valve side valve chamber and the outlet channel; The liquid ejecting apparatus according to claim 3, further comprising: a second driving unit that drives the valve body.

  That is, in the invention of claim 4, by opening or closing the branch channel side opening formed in the bottom surface of the second valve side valve chamber, the inflow of the liquid into the discharge channel is opened or blocked at the inlet of the branch channel. It is possible to prevent a portion where the liquid is retained when the second valve is closed.

  According to a fifth aspect of the present invention, the second valve body has a tapered tip portion that tapers toward the branch flow channel side opening. Is provided.

  That is, in the invention of claim 5, since the second valve body has a tapered tip portion tapering toward the branch flow path side opening, the insertion amount of the second valve body into the branch flow path side opening is reduced. By adjusting, the opening area of the branch channel side opening can be adjusted, and the flow rate of the liquid flowing into the discharge channel from the discharge channel can be adjusted.

  According to the invention of claim 6, the valve main body is formed from one base block, the inlet flow passage side opening is opened and closed by the first valve body, and the inlet flow passage side opening is the bottom of the first valve side valve chamber. Provided in the center, the branch channel side opening is provided in the center of the bottom of the second valve side valve chamber, and the first drive unit and the second drive unit have respective axes that are the communication channel and the outlet channel. Arranged so as to be orthogonal to the flow path axis, and the branch flow path is disposed in a direction facing the second valve body across the flow path axis of the communication flow path and the outlet flow path, and the first drive unit Comprises a first cylinder extending in the vertical direction, and a first piston arranged to be movable up and down in the first cylinder, and the first piston includes a valve body side of the first cylinder. 1st diaphragm pressed on Is provided with a lower shaft portion that is connected to the first valve body at the tip, and the first cylinder includes an exterior of the first cylinder, an upper end surface of the first diaphragm presser, and the first A space formed by the inner peripheral surface of the cylinder and the lower end surface of the first piston, or formed by the outside of the first cylinder, the ceiling surface and inner peripheral surface of the first cylinder, and the upper end surface of the first piston. A vent hole is provided in at least one of the spaces, and the second drive unit includes a second cylinder extending in the vertical direction, and a second piston arranged to be movable up and down in the second cylinder. The second piston is provided with a lower shaft portion that penetrates a second diaphragm retainer disposed on the valve body side of the second cylinder and is connected to the second valve body at a tip portion. The two cylinders have the second cylinder Part, a space formed by the upper end surface of the second diaphragm presser, the inner peripheral surface of the second cylinder, and the lower end surface of the second piston, or the outside of the second cylinder, the ceiling surface of the second cylinder, The liquid ejection device according to claim 4 or 5, wherein a vent is provided in at least one of a space formed by an inner peripheral surface and an upper end surface of the second piston. .

  That is, in the invention of claim 6, the manifold valve can be configured simply and compactly.

  According to a seventh aspect of the present invention, the flow rate adjusting means for adjusting the flow rate of air passing through the vent is provided in the vent of the first cylinder. A liquid ejection device is provided.

  That is, in the invention of claim 7, since the first valve can be closed gradually, the liquid in the discharge passage is biased toward the discharge opening when the first valve is suddenly closed. And dripping of liquid from the discharge opening can be prevented.

  According to the description of claim 8, the manifold valve is provided with a flow rate adjusting means for adjusting the flow rate of the liquid flowing from the discharge flow path toward the discharge flow path. A liquid ejection apparatus according to any one of claims 5 to 5 is provided.

  In other words, according to the eighth aspect of the invention, the liquid in the discharge channel can be gently allowed to flow toward the discharge channel. By gently flowing the liquid in the discharge flow path that flows toward the discharge flow path, it is possible to prevent the liquid surface from being destroyed. Here, “liquid level destruction” will be described. First, when the liquid in the discharge channel starts to flow toward the discharge channel due to the siphon effect, the liquid level of the liquid in the discharge opening is formed so as to be substantially orthogonal to the channel axis. It is desirable that the liquid level when the liquid is flowing toward the discharge channel be in the same state as when the liquid begins to flow toward the discharge channel (that is, the state where the liquid level is substantially perpendicular to the channel axis). . However, when the liquid suddenly flows, the liquid surface is inclined with respect to the channel axis due to the difference in flow velocity between the liquid near the center of the channel and the liquid near the inner peripheral surface of the channel or the undulation of the channel Will come to be. When the inclination of the liquid level increases, the liquid level extends in the direction of the flow path axis, and liquid is present in one direction in the radial direction of the flow path and air is present in the other direction. Therefore, “destruction of the liquid level” means that the liquid level extends in the direction of the flow path axis. By preventing the liquid surface from being destroyed, the liquid can effectively receive a siphon effect, and air accumulation can be made difficult to occur in the flow path. In addition, in the case of repeatedly discharging and stopping the liquid by gently flowing the liquid, the discharge of the liquid is resumed while the liquid level of the liquid flowing toward the discharge channel exists in the discharge channel. And the time lag until the liquid is re-discharged can be shortened. Further, the space required for installing the flow rate adjusting means can be reduced as compared with the case where the flow rate adjusting means is provided outside the manifold valve.

  According to the invention of claim 9, the second valve is provided with an opening adjusting stem which is a flow rate adjusting means for adjusting the flow rate of the liquid flowing from the discharge flow channel toward the discharge flow channel. The opening adjusting stem is disposed so as to be movable up and down in the second cylinder, and has a shaft portion having a male screw portion screwed with a female screw portion provided in the second cylinder, and the second valve. The liquid ejecting apparatus according to claim 6 or 7, further comprising an engaging portion that contacts the upper end surface of the second piston when the valve is open.

  That is, according to the ninth aspect of the present invention, the flow rate of the liquid flowing from the discharge channel to the discharge channel can be easily adjusted using a simple configuration.

  According to a tenth aspect of the invention, in the liquid ejecting apparatus according to the first or second aspect, the first valve and the second valve are separate bodies and are arranged separately from each other. Provided.

  That is, in the invention of claim 10, the place where the first valve and the second valve are arranged can be designed flexibly.

  According to the eleventh aspect of the present invention, the first valve and the second valve are integrally coupled, and the flow of the liquid between the supply flow path and the discharge flow path can be performed with one valve body. A state where the liquid flow between the discharge flow path and the discharge flow path is blocked, and the liquid flow between the supply flow path and the discharge flow path is blocked, and 3. The liquid discharge according to claim 1, wherein the liquid discharge is configured as one switching valve that switches a state in which the flow of the liquid between the discharge flow path and the discharge flow path is opened. 4. An apparatus is provided.

  That is, in the invention of claim 11, the number of valves necessary for preventing dripping can be reduced and the space for installing the valves can be reduced. Moreover, since the dripping can be prevented by operating one valve body, the operation of the valve becomes easy.

  According to the invention of claim 12, at least one measuring instrument of a liquid level meter and a flow meter is arranged in the discharge flow path or the discharge flow path, and the second valve is based on the measurement result of the measuring instrument. 3. The liquid discharge apparatus according to claim 1, wherein the liquid flow between the discharge flow path and the discharge flow path is opened or blocked.

  That is, according to the twelfth aspect of the present invention, when the liquid in the discharge channel is caused to flow toward the discharge channel, the position where the liquid surface of the liquid stops moving and the flow rate of the liquid can be freely controlled. The liquid level gauge controls the position where the liquid level of the liquid in the discharge flow path that moves to the discharge flow path side stops moving as close as possible to the discharge opening, preventing dripping from the discharge opening. In addition, the time lag from when the liquid discharge is stopped to when the discharge is restarted can be reduced. Further, by controlling the flow rate of the liquid in the discharge flow path to the discharge flow path side with the flow meter, the liquid discharge amount can be managed more accurately.

  According to a thirteenth aspect of the present invention, when the liquid filled in the discharge flow path has a liquid level at the discharge opening and flows to the discharge opening side by the siphon effect, the liquid level is 3. The liquid ejection device according to claim 1, wherein the second valve blocks the flow of the liquid between the ejection flow path and the discharge flow path before flowing into the valve. Is provided.

  That is, in the invention of claim 13, in the operation of discharging the liquid again, the time lag from the state where the liquid discharge is stopped to the time when the discharge is restarted can be reduced.

  According to the first to thirteenth aspects of the present invention, the liquid ejection device for ejecting liquid does not use extra energy, and after the liquid ejection is stopped, the liquid ejection device promptly exits the ejection opening. A liquid discharge apparatus capable of preventing dripping can be provided.

It is a figure which shows schematic structure of the liquid discharge apparatus which concerns on 1st embodiment of this invention in a full water state. It is a figure which shows schematic structure of the liquid discharge apparatus which concerns on 1st embodiment of this invention in a discharge state. It is a figure which shows schematic structure of the liquid discharge apparatus which concerns on 1st embodiment of this invention in a stop state. It is a figure which shows schematic structure of the liquid discharge apparatus which concerns on 2nd embodiment of this invention. It is a figure which shows schematic structure of the liquid discharge apparatus which concerns on 3rd embodiment of this invention. It is a longitudinal cross-sectional view which shows schematic structure of the manifold valve used for the liquid discharge apparatus which concerns on 3rd embodiment of this invention. It is a figure which shows schematic structure of the liquid discharge apparatus which concerns on 4th embodiment of this invention. It is a figure which shows schematic structure of the conventional liquid discharge apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but it goes without saying that the present invention is not limited to these embodiments.

-First embodiment-
A liquid ejection apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1A to 1C are diagrams illustrating a schematic configuration of the liquid ejection apparatus according to the first embodiment. In the first embodiment, a liquid supply means 1 as a liquid supply source, a supply flow path 2 for transferring the liquid supplied from the liquid supply means 1, a discharge flow path 3 having a discharge opening 13, and a supply flow A first valve 5 connected to the path 2 and the discharge flow path 3, a discharge flow path 4 having a discharge opening 14, and a second valve 6 connected to the discharge flow path 3 and the discharge flow path 4 are provided. The liquid supply unit 1 further includes a liquid tank 7 that stores the liquid, and a pumping unit 8 that pumps the liquid from the liquid tank 7 to the supply flow path 2. In the first embodiment, the liquid ejecting apparatus is mainly disposed inside the semiconductor manufacturing apparatus, and ejects a photoresist liquid that is a liquid onto the silicon wafer 12 that is an object.

  In the first embodiment, the liquid tank 7 is made of polytetrafluoroethylene (hereinafter referred to as PTFE) and is a container for storing a liquid. Further, a pump is connected to the liquid tank 7 as the pressure feeding means 8. The pumping means 8 is not particularly limited as long as the liquid can be transferred to the use point 9. In addition to the pump, for example, a device for pressurizing the liquid by pressurizing the inside of the liquid tank 7 with air, nitrogen gas or the like can be used. . Here, the use point 9 is a place where the liquid pumped from the supply flow path 2 through the discharge flow path 3 is actually used. In the first embodiment, a spin chuck 10 is disposed at the use point 9, and a silicon wafer 12 is placed on the rotating disk 11 of the spin chuck 10.

  In the first embodiment, the supply flow path 2 is formed of a tube made of a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (hereinafter referred to as PFA). One end of the supply channel 2 is connected to the pressure feeding means 8, and the other end is connected to the first valve 5. In the first embodiment, the discharge flow path 3 is formed by a tube made of PFA, and is branched in two directions along the way. One end of the discharge flow path 3 is connected to the first valve 5, one other end of the branched discharge flow path 3 is connected to the second valve 6, and the other other end transfers liquid to the silicon wafer 12. Thus, the discharge opening 13 is discharged. In the first embodiment, the discharge channel 4 is formed of a PFA tube. A discharge channel inlet side opening 15 is formed at one end of the discharge channel 4, and a discharge opening 14 is formed at the other end. The discharge channel inlet side opening 15 of the discharge channel 4 is connected to the second valve 6, and the discharge opening 14 is connected to the liquid tank 7. Here, the discharge opening 13 of the discharge flow path 3 is disposed at a position higher than the discharge opening 14 of the discharge flow path 4 and the discharge flow path inlet side opening 15. The first valve 5 is an electric diaphragm valve in the first embodiment, and is connected to the supply flow path 2 and the discharge flow path 3. The valve opening degree of the first valve 5 is controlled by a control unit (not shown), and the liquid flow between the supply flow path 2 and the discharge flow path 3 is opened or blocked. The second valve 6 is an electric diaphragm valve in the first embodiment, and is connected to the discharge flow path 3 and the discharge flow path 4. The valve opening degree of the second valve 6 is controlled by a control unit (not shown), and the flow of the liquid between the discharge channel 3 and the discharge channel 4 is opened or blocked.

  Next, the operation of the liquid ejection apparatus according to the first embodiment of the present invention will be described with reference to FIGS.

  First, a situation where all the flow paths in the liquid ejection apparatus are filled with liquid will be described. FIG. 1A shows a state in which all the flow paths of the liquid ejection device according to the first embodiment are filled with liquid in a substantially full state. In FIG. 1A, the first valve 5 is in an open state. That is, the supply channel 2 and the discharge channel 3 are in communication. The second valve 6 is open. That is, the discharge flow path 3 and the discharge flow path 4 are in communication. The liquid flows in the liquid ejection device in a substantially full state as indicated by the arrow in FIG. 1A. The liquid is pumped from the liquid tank 7 to the supply channel 2 by the pumping means 8 and reaches the first valve 5. Furthermore, the liquid flows into the discharge flow path 3 through the first valve 5. The liquid that has flowed into the discharge flow path 3 is branched in two directions at the branch point. In one flow path, the liquid flows through the discharge flow path 3 to the discharge opening 13, and in the other flow path, the second valve 6. After that, it flows in the discharge channel 4 to the discharge opening 14. When the inside of the discharge channel 4 is filled with the liquid, the second valve 6 is closed. At this time, the inside of the discharge channel 4 is kept substantially full, and a liquid level is formed in the vicinity of the discharge opening 14. Similarly, when the supply channel 2 and the discharge channel 3 are filled with the liquid, the first valve 5 is closed. At this time, the supply channel 2 and the discharge channel 3 are substantially full, and a liquid level is formed in the vicinity of the discharge opening 13.

  Next, a situation where liquid is discharged will be described. FIG. 1B shows a discharge state of the liquid discharge apparatus according to the first embodiment. In FIG. 1B, the first valve 5 is in an open state. That is, the supply channel 2 and the discharge channel 3 are in communication. The second valve 6 is in a closed state. That is, the communication between the discharge flow path 3 and the discharge flow path 4 is blocked. The liquid pumped by the liquid supply means 1 flows in the liquid discharge apparatus as indicated by the arrow in FIG. 1B and is discharged from the discharge opening 13 onto the silicon wafer 12.

  Next, a situation where the liquid discharge is stopped will be described. FIG. 1C shows a stopped state of the liquid ejection apparatus according to the first embodiment. In FIG. 1C, the first valve 5 is in a closed state. That is, the communication between the supply flow path 2 and the discharge flow path 3 is blocked, and the supply of liquid from the supply flow path 2 to the discharge flow path 3 is stopped. In FIG. 1C, the second valve 6 is open. The second valve 6 is opened at the same time or almost simultaneously with the closing of the first valve 5, and connects the discharge flow path 3 and the discharge flow path 4. Immediately after the first valve 5 is closed, the liquid in the discharge channel 3 tends to flow toward the discharge opening 13. However, the discharge opening 13 is arranged at a position higher than the discharge opening 14, and when the second valve 6 is opened, the liquid existing in a substantially full state in the discharge flow path 3 and the discharge flow path 4 is siphoned. Receive the effect. The liquid subjected to the siphon effect is affected by gravity and flows toward the discharge opening 14 as indicated by an arrow in FIG. 1C. At this time, since the liquid level in the vicinity of the discharge opening 13 quickly moves toward the discharge flow path 4, the dripping from the discharge opening 13 to the use point 9 after the stop of the liquid discharge to the silicon wafer 12 is prevented quickly. can do. By preventing dripping from the discharge opening 13, the liquid can be uniformly discharged onto an object such as the silicon wafer 12. Further, since the liquid in the vicinity of the discharge opening 13 flows to the discharge channel 4 side due to the siphon effect, there is no need for a device for depressurizing the discharge channel 4 side, and the configuration of the liquid discharge device is simplified and the capital investment burden is reduced. Reduction and energy saving can be achieved. In addition, in order to move the liquid in the vicinity of the discharge opening 13 toward the discharge flow path 4, it is not necessary to depressurize the discharge flow path 4 side of the second valve 6, so that the liquid moves to the discharge flow path 4 side. The influence of the pressure loss exerted can be reduced, and the degree of freedom when designing the discharge flow path 3 can be increased. Further, since the liquid in the vicinity of the discharge opening 13 flows toward the discharge channel 4 due to the siphon effect, the liquid surface in the vicinity of the discharge opening 13 is surely discharged without being restricted by the volume of the liquid flowing in the discharge channel 4. It can be moved to the flow path 4 side.

  Here, if the discharge channel inlet side opening 15 is arranged at a position lower than the discharge opening 13, if the discharge channel 3 side is filled with liquid from the discharge channel inlet side opening 15, the siphon effect is obtained. Since it can be expressed, dripping from the discharge opening 13 can be prevented more effectively. In this case, dripping from the discharge opening 13 can be prevented without performing the situation described with reference to FIG. 1A, that is, without filling the inside of the discharge channel 4 with the liquid. Further, in order to more effectively prevent dripping from the discharge opening 13 by using the siphon effect, it is desirable that the discharge opening 14 is disposed at a position lower than the discharge flow path inlet side opening 15. Further, in the flow path from the discharge opening 13 to the discharge opening 14, the liquid level at a high position of the liquid existing in the flow path is always present on the discharge opening 13 side, and the liquid level at the low position is always on the discharge opening 14 side. It is desirable to make it exist. By making the liquid level on the discharge opening 13 side always exist at a high position, it is possible to prevent the liquid flow from being stagnant when the liquid flows from the discharge opening 13 to the discharge opening 14. The design of the discharge flow path 3 and the discharge flow path 4 is not particularly limited as long as the dripping from the discharge opening 13 can be prevented by the siphon effect. The opening 14 may be in contact with the liquid tank 7.

  In 1st embodiment, since the 1st valve 5 and the 2nd valve 6 are comprised separately, and are arrange | positioned apart, the 1st valve 5 and the 2nd valve 6 are set according to the surrounding condition. It can be arranged on a case-by-case basis. In the first embodiment, electric valves are used as the first valve 5 and the second valve 6, but the valve drive system may be either a pneumatic system or a manual system, and is not particularly limited. In the first embodiment, the first valve 5 and the second valve 6 operate in conjunction with each other. Interlocking the first valve 5 and the second valve 6 is preferable because liquid dripping from the discharge opening 13 can be stably prevented. In the first embodiment, the second valve 6 is set to open almost simultaneously with the closing of the first valve 5, but the timing at which the first valve 5 and the second valve 6 are interlocked is particularly It is not limited. For example, in order to prevent liquid dripping more reliably, the operation of opening the second valve 6 is started in the middle of the operation of closing the first valve 5, and the supply is performed shortly before the liquid discharge is stopped. A flow from the flow path 2 to the discharge flow path 4 may be provided in advance. In the first embodiment, the first valve 5 and the second valve 6 are both diaphragm valves. However, the first valve 5 and the second valve 6 are not particularly limited as long as the liquid flow can be opened or blocked. In addition to the diaphragm valve, there are a ball valve, a butterfly valve, a stop valve, a gate valve, a needle valve, and the like. That is, dripping from the discharge opening 13 can be reliably prevented by using a valve having a simple configuration that does not have a suck back function.

-Second embodiment-
A liquid ejection apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a diagram illustrating a schematic configuration of the liquid ejection apparatus according to the second embodiment. The second embodiment is different from the first embodiment in that an air bleeding mechanism 21, a constant pressure valve 22, a liquid level sensor 23, a flow meter 24, and an orifice 25 are provided in a flow path in the liquid ejection device. It was to have. In addition, the same code | symbol is attached | subjected to the location which has the same function as 1st embodiment, and the difference with 1st embodiment is mainly demonstrated below.

  The air vent mechanism 21 is, for example, an air vent valve. The air vent mechanism 21 is arranged in the middle of the supply flow path 2 in order to prevent air from staying in the liquid ejection device and hindering the expression of the siphon effect. The constant pressure valve 22 is disposed in the middle of the supply flow path 2 in order to keep the pressure in the discharge flow path 3 at a constant pressure. The liquid level sensor 23 is, for example, a capacitive proximity sensor. The liquid level sensor 23 is disposed in the discharge flow path 3 as a liquid level gauge that detects the position of the liquid level in the discharge flow path 3. The liquid level sensor 23 detects that the liquid level in the discharge flow path 3 has moved to the discharge flow path 4 side from the mounting position of the liquid level sensor 23, and a detection signal is sent to a control unit (not shown). Output to. The flow meter 24 is, for example, an ultrasonic flow meter. The flow meter 24 is disposed in the discharge channel 3 in order to detect the flow rate and the integrated flow rate of the liquid flowing into the discharge channel 4 from the discharge channel 3. The flow meter 24 detects a flow rate and an integrated flow rate when the liquid in the discharge flow channel 3 flows to the discharge flow channel 4 side, and outputs a detection signal to a control unit (not shown). The orifice 25 is a plate in which a PTFE plate formed in an annular shape is built in a union joint. The orifice 25 is disposed in the vicinity of the discharge channel inlet side opening 15 of the discharge channel 4 in order to limit the flow rate of the liquid flowing into the discharge channel 4 from the discharge channel 3. The orifice 25 can easily adjust the flow rate by exchanging a plate formed in an annular shape.

  Next, the operation of the liquid ejection apparatus according to the second embodiment of the present invention will be described with reference to FIG.

  The liquid pumped by the liquid supply unit 1 flows in the liquid discharge apparatus as indicated by the solid line arrow in FIG. 2 and is discharged from the discharge opening 13 to the silicon wafer 12. When liquid is pumped from the liquid tank 7, air may be mixed into the liquid ejecting apparatus, but the mixed air is collected by the air vent mechanism 21 and discharged out of the liquid ejecting apparatus. Thereby, the siphon effect can be effectively expressed by preventing air from staying in the discharge flow path 3. The liquid pumped to the supply flow path 2 by the pump as the pumping means 8 flows downstream with pressure fluctuations, but is adjusted to a constant pressure by passing through the constant pressure valve 22. Since the liquid is adjusted to a constant pressure and flows through the discharge flow path 3, the flow rate of the liquid discharged to the silicon wafer 12 can be precisely controlled. In the second embodiment, the air vent mechanism 21 is disposed independently, but may be disposed integrally within the first valve 5.

  When the first valve 5 is closed and the second valve 6 is opened to stop the discharge of the liquid, the liquid in the discharge flow path 3 is discharged as indicated by the broken line arrow in FIG. 2 due to the siphon effect. It flows toward the opening 14. At this time, when the liquid level sensor 23 detects that the liquid level formed in the discharge opening 13 has reached the mounting position of the liquid level sensor 23, a detection signal is output to a control unit (not shown). Then, the second valve 6 is closed. When the second valve 6 is closed, the liquid does not flow toward the discharge opening 14. As described above, by using the liquid level sensor 23, the amount of liquid level formed in the discharge opening 13 when the discharge is stopped is moved to the discharge channel 4 side by the siphon effect (hereinafter referred to as return amount) or liquid. The position where the surface stops (hereinafter referred to as the stop position) can be freely controlled. By reducing the return amount and setting a stop position near the discharge opening 13, it is possible to prevent liquid dripping and to discharge quickly when the discharge to the silicon wafer 12 is resumed, thereby reducing the time lag. be able to. Since the liquid level sensor 23 can directly detect the position of the liquid level, it is particularly suitable when controlling the stop position. In the second embodiment, the stop position is controlled by one liquid level sensor 23, but a plurality of liquid level sensors 23 may be used. For example, when a plurality of types of liquids are used, the stop position may be changed according to the properties of the liquids.

  The return amount and stop position can also be controlled by the flow meter 24. When the liquid in the discharge channel 3 flows to the discharge opening 14 due to the siphon effect, the integrated flow rate of the liquid that has passed through the flow meter 24 is detected. When the integrated flow rate reaches a predetermined value, the detection signal is output to a control unit (not shown), and the second valve 6 is closed. In the second embodiment, when the liquid level sensor 23 does not operate, a detection signal from the flow meter 24 is output to a control unit (not shown). Thus, by arranging two of the liquid level sensor 23 and the flow meter 24 in the discharge flow path 3, the return amount and the stop position can be controlled stably. Since the flow meter 24 can directly detect the flow rate of the liquid, it is particularly suitable for managing the discharge amount. Further, the flow meter 24 can use the flow rate detected by the flow meter 24 as a guide when adjusting the hole diameter of the orifice 25.

  In the second embodiment, the return amount and the stop position are controlled using the liquid level sensor 23 and the flow meter 24. However, the liquid flowing from the discharge flow path 3 toward the discharge opening 14 due to the siphon effect is used. Any method can be used as long as the flow can be stopped, and there is no particular limitation. For example, the valve may be automatically closed after a predetermined time has elapsed since the opening of the second valve 6. When the second valve 6 is opened for a short period of time, the stop position becomes closer to the discharge opening 13, so that the lime lag can be reduced when the discharge is resumed. In the case where liquid discharge and stop are frequently repeated, it is preferable to open and close both the first valve 5 and the second valve 6 in a short time.

  When the liquid flows through the orifice 25, the flow of the liquid can be made gentle. That is, the flow rate when the liquid flows from the discharge channel 3 toward the discharge opening 14 can be reduced. When the flow rate of the liquid flowing from the discharge flow path 3 toward the discharge opening 14 is slowed, the liquid level of the liquid can be prevented from being destroyed. By preventing the breakage of the liquid surface, it is possible to prevent the expression of the siphon effect from being hindered or to cause air accumulation in the flow path, and the siphon effect can be effectively applied to the liquid. Further, when the flow rate of the liquid flowing from the discharge flow path 3 toward the discharge opening 14 is slowed, the return amount using the liquid level sensor 23 and the flow meter 24 can be controlled more precisely. Further, when the flow rate of the liquid flowing from the discharge flow path 3 toward the discharge opening 14 is slowed down, the stop position of the liquid level can be easily located in the vicinity of the discharge opening 13 even if the liquid level sensor 23 and the flow meter 24 are not provided. Can be adapted. When the stop position is closer to the discharge opening 13, the time lag when restarting the discharge can be reduced. In the second embodiment, an union joint with a plate formed in an annular shape is used as the orifice 25. However, a flow rate adjusting valve or the like may be newly installed to limit the flow rate. If it is possible, there is no particular limitation. In the second embodiment, the state of liquid discharge and stop is the same as in the first embodiment, and a description thereof will be omitted. In addition, since the action of quickly preventing dripping from the discharge opening 13 when the discharge is stopped is the same as in the first embodiment, the description thereof is omitted.

-Third embodiment-
A liquid ejection apparatus according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a diagram illustrating a schematic configuration of the liquid ejection apparatus according to the third embodiment. The third embodiment is different from the first embodiment and the second embodiment in that the first valve 5 and the second valve 6 are integrally coupled and configured as one manifold valve. is there. FIG. 4 is a longitudinal sectional view showing a schematic configuration of a manifold valve used in the liquid ejection apparatus according to the third embodiment. In addition, the same code | symbol is attached | subjected to the location which has the same function as 1st embodiment and 2nd embodiment, and the difference with 1st embodiment and 2nd embodiment is mainly demonstrated below. To do.

  As shown in FIGS. 3 and 4, the manifold valve 31 includes a first valve 5 and a second valve 6 that are integrally coupled. In the third embodiment, the space required for installing the first valve 5 and the second valve 6 is reduced by changing the first valve 5 and the second valve 6 to the manifold valve 31. Can do. A detailed configuration of the manifold valve 31 will be described with reference to FIG. The manifold valve 31 mainly includes a valve body 32, cylinder bodies 51a and 51b, pistons 61a and 61b, diaphragm holders 71a and 71b, and valve bodies 81a and 81b. The valve body 32 and the cylinder bodies 51a and 51b are pistons 61a and 61b. The diaphragm holders 71a and 71b and the valve bodies 81a and 81b are fixed with bolts and nuts (not shown). In FIG. 4, the upward direction is the direction on the cylinder body 51a, 51b side, and the downward direction is the direction on the valve body 32 side.

  The valve body 32 is made of PTFE, for example, and is formed in a substantially block shape. A first hole 33 a and a second hole 33 b are formed in the upper part of the valve body 32. The diameter of the first hole portion 33a is formed larger than the diameter of the valve body portion 82a of the first valve body 81a and the inlet channel side opening 34 provided at the center of the bottom of the first hole portion 33a. Similarly, the diameter of the second hole 33b is formed larger than the diameter of the stepped portion 48 and the branch flow passage side opening 35 provided at the bottom center of the second valve body 81b and the second hole 33b. A space formed by the first hole 33a and the first valve body 81a becomes the first valve side valve chamber 36a, and the peripheral part of the inlet flow path side opening 34 is pressed and separated by the valve body 82a of the first valve body 81a. The first valve seat 37a is provided. Similarly, the space formed by the second hole portion 33b and the valve body portion 82b of the second valve body 81b becomes the second valve side valve chamber 36b, and the peripheral portion of the stepped portion 48 is pressed by the second valve body 81b. The second valve seat 37b is separated. A communication channel side first opening 39a is provided on the inner peripheral surface of the first valve side valve chamber 36a, and a communication channel side second opening 39b is provided on the inner peripheral surface of the second valve side valve chamber 36b. A communication flow path 38 is connected to the communication flow path side first opening 39a and the communication flow path side second opening 39b, and the first valve side valve chamber 36a and the second valve side valve chamber 36b are connected. At the peripheral edge portions of the first hole portion 33a and the second hole portion 33b, annular projection portions 49a and 49b having the same central axis as the respective central axes, and annular groove portions 50a and 50b having a larger diameter than the annular projection portion are formed. ing.

  An inlet opening 41 is formed on one end surface of the valve body 32, and an outlet opening 42 and a branch opening 43 are formed on the other end surface. The branch opening 43 has a smaller diameter than the outlet opening 42. An inlet channel 44 communicates with the inlet opening 41, and the inlet channel 44 communicates with the inlet channel side opening 34. The inlet channel 44 is connected to the supply channel 2 by a connecting portion 40 a formed so as to protrude around the inlet opening 41. An outlet channel 45 communicates with the outlet opening 42, and the outlet channel 45 communicates with an outlet channel side opening 46 formed on the inner peripheral surface of the second hole 33b. The outlet channel 45 is disposed on the same channel axis as the communication channel 38. The outlet channel 45 is connected to the discharge channel 3 by a connecting portion 40b formed so as to protrude around the outlet opening 42. The inner diameter of the outlet channel 45 is formed to be substantially the same as the inner diameter of the discharge channel 3. A branch channel 47 communicates with the branch opening 43, and the branch channel 47 communicates with the branch channel side opening 35. The branch flow path 47 is disposed between the communication flow path 38 and the outlet flow path 45 at a position facing the second valve body 81b. The branch flow path 47 is connected to the discharge flow path 4 by a connecting portion 40 c formed so as to protrude around the branch opening 43. The inner diameter of the branch passage 47 on the second valve side valve chamber 36 b side is formed to be substantially the same as the outlet passage 45. The inner diameter of the branch channel 47 on the side of the branch opening 43 is smaller than that of the outlet channel 45 and is substantially the same as or larger than that of the discharge channel 4. The connection between the flow paths in the manifold valve (inlet flow path 44, outlet flow path 45, branch flow path 47) and the flow paths outside the manifold valve (supply flow path 2, discharge flow path 3, discharge flow path 4) is particularly There is no limitation, and the connection is made by a general connection method.

  Next, referring to FIG. 4, the detailed configuration of the first drive unit including the first cylinder body 51 a, the piston 61 a, and the diaphragm presser 71 a for driving the first valve body 81 a of the first valve 5. explain. Here, the axis of the first drive unit is arranged so as to be orthogonal to the channel axes of the communication channel 38 and the outlet channel 45.

  The first cylinder body 51a is made of, for example, PTFE, and has a substantially quadrangular prism shape. A large-diameter cylindrical hole 52a is formed in the lower part of the first cylinder body 51a, and the internal space of the large-diameter cylindrical hole 52a becomes a cylindrical space 53a. A small-diameter cylindrical hole portion 54 is formed on the bottom surface of the large-diameter cylindrical hole portion 52a (upward in FIG. 4). An annular hole 55a having the same central axis as the central axis of the small diameter cylindrical hole 54 is formed on the bottom surface of the large diameter cylindrical hole 52a. A spring that urges the first piston 61a downward is disposed in the annular hole portion 55a. A first piston 61a is disposed in the cylindrical space 53a of the first cylinder body 51a so as to be movable up and down. A space defined by the bottom surface and the inner peripheral surface of the large-diameter cylindrical hole 52a of the first cylinder body 51a, the outer peripheral surface of the first piston 61a, and the upper surface of the flange portion 62a of the first piston 61a is an upper space 56a. Similarly, a space defined by the inner peripheral surface of the large-diameter cylindrical hole 52a, the outer peripheral surface of the first piston 61a, the lower surface of the flange 62a of the first piston 61a, and the upper surface of the first diaphragm retainer 71a is defined as a lower space 57a. Become. At the upper part of the first cylinder body 51a, vent holes communicating with the annular hole portion 55a, the small diameter cylindrical hole portion 54, and the lower space 57a are formed. A flow rate adjusting valve 95 that adjusts the flow rate of the air exhausted from the lower space 57a is disposed at the vent opening communicating with the lower space 57a.

  The first piston 61a is made of PTFE, for example. The first piston 61a includes a flange portion 62a extending in the radial direction, a large-diameter upper shaft portion 63a protruding from the upper surface of the flange portion 62a, a small-diameter upper shaft portion 64a protruding from the upper surface of the large-diameter upper shaft portion 63a, And a lower shaft portion 65a protruding from the lower surface of the flange portion 62a. The first piston 61a is arranged to move up and down in the cylindrical space 53a of the first cylinder body 51a. The flange 62a is slidably formed in the large-diameter cylindrical hole 52a of the first cylinder body 51a, and an O-ring is attached to the outer peripheral surface of the flange 62a. The small diameter upper shaft portion 64a is slidably formed in the small diameter cylindrical hole portion 54 of the first cylinder body 51a. By inserting the small-diameter upper shaft portion 64a into the small-diameter cylindrical hole portion 54, it is possible to prevent the central axis of the first piston 61a from being inclined. The lower shaft portion 65a is slidably formed in the through hole of the first diaphragm presser 71a. A male screw portion is formed at the tip of the lower shaft portion 65a, and the first valve body 81a is screwed thereon.

  The first diaphragm holder 71a is made of PTFE, for example. At the center of the first diaphragm presser 71a, an O-ring is fitted on the inner peripheral surface, and a through hole is formed through which the shaft portion of the first piston 61a is inserted in a watertight state. A flange portion extends in the radial direction on the outer peripheral surface of the middle portion of the first diaphragm presser 71a. An O-ring is fitted on the upper outer peripheral surface of the first diaphragm retainer 71a, and the upper portion of the first diaphragm retainer 71a is fitted and inserted into the large-diameter cylindrical hole 52a of the first cylinder body 51a in a watertight state. The lower part of the first diaphragm holder 71 a is inserted into the first hole 33 a of the valve body 32. The first diaphragm retainer 71a sandwiches and fixes the diaphragm portion 83a of the first valve body 81a in a watertight state between the first diaphragm retainer 71a and the valve body 32.

  The first valve body 81a is made of PTFE, for example. A valve body portion 82a protruding downward is formed on the lower surface of the center of the first valve body 81a. A female screw portion that is screwed to the male screw portion of the lower shaft portion 65a of the first piston 61a is formed at the upper center of the valve body portion 82a. The first valve body 81a is movable up and down as the first piston 61a moves up and down, is pressed against and separated from the first valve seat 37a of the valve body 32, and flows from the inlet channel 44 to the communication channel 38 Is shut off or opened. A diaphragm portion 83a extends from the upper surface peripheral portion of the valve body portion 82a of the first valve body 81a. The diaphragm portion 83a extends in both the vertical direction and the horizontal direction, and is formed in a mortar shape that spreads upward from the valve body portion 82a as a whole.

  Next, referring to FIG. 4, the second cylinder body 51b, the second piston 61b, the second diaphragm presser 71b, and the opening adjustment stem 91 for driving the second valve body 81b of the second valve 6 are provided. A detailed configuration of the second drive unit provided will be described. Here, the axis of the second drive unit is configured to be orthogonal to the channel axes of the communication channel 38 and the outlet channel 45. Hereinafter, differences from the first drive unit will be mainly described.

  A large-diameter cylindrical hole 52b is formed in the second cylinder body 51b. On the bottom surface of the large-diameter cylindrical hole portion 52b (upward in FIG. 4), a female screw portion that communicates with the outside of the second cylinder main body 51b and is screwed to the opening adjusting stem 91 is formed. Other configurations of the second cylinder body 51b are the same as those of the first cylinder body 51a. That is, an annular hole 55b is formed inside. The second piston 61b and the second valve body 81b form an upper space 56b and a lower space 57b. Further, vent holes communicating with the annular hole 55b and the lower space 57b are formed on the outer peripheral surface. A second piston 61b is arranged in the cylindrical space 53b so as to be movable up and down.

  The upper surface of the flange portion 62b of the second piston 61b is formed flat. A receiving portion that receives the engaging portion 94 of the opening adjusting stem 91 is formed on the upper surface of the flange portion 62b. Other configurations of the second piston 61b are the same as those of the first piston 61a. That is, a lower shaft portion 65b that is inserted in a watertight state through the through hole of the second diaphragm presser 71b is formed at the lower portion, and a second valve body 81b is connected to the tip of the lower shaft portion 65b.

  The second diaphragm retainer 71b is formed in the same manner as the first diaphragm retainer 71a. That is, the second diaphragm retainer 71b is formed with a through-hole through which the lower shaft portion 65b of the second piston 61b is inserted in a watertight state at the center, and a flange portion is extended on the outer peripheral surface of the middle portion.

  The second valve body 81b has a valve body portion 82b formed in a shape different from that of the first valve body 81a. That is, the valve body portion 82b has a needle portion 84b that protrudes from the center portion of the lower surface and swells downward. In addition, an inclined surface is formed on the lower surface of the valve body portion 82b so as to be pressed against and separated from the second valve seat 37b. The inclined surface formed on the lower surface of the valve body portion 82b is inclined downward from the outer peripheral edge of the valve body portion 82b toward the center. Further, the valve body portion 82 a is formed in a shape that does not block the communication state between the communication flow path 38 and the outlet flow path 45. The other part of the second valve body 81b is formed in the same manner as the first valve body 81a, and a diaphragm part 83b extends from the valve body part 82b of the second valve body 81b.

  The opening adjusting stem 91 is made of, for example, polypropylene (hereinafter referred to as PP). The opening adjustment stem 91 is arranged so as to freely move up and down in the cylindrical space 53b of the second cylinder body 51b. On the upper portion of the opening adjustment stem 91, there is provided a shaft portion 92 formed with a male screw portion that is screwed into a female screw portion provided in the second cylinder body 51b. An engaging portion 94 that extends radially from the lower portion of the shaft portion 92 and contacts the upper surface of the second piston 61b is provided at the lower portion of the opening adjustment stem 91 when the second valve 6 is opened. It has been. An opening fixing nut 93 is attached to the shaft portion 92 of the opening adjustment stem 91 after being screwed to the second cylinder body 51b.

  Next, the operation of the liquid ejection apparatus according to the third embodiment of the present invention will be described with reference to FIGS. 3 and 4.

  The liquid pumped from the liquid tank 7 by the pumping means 8 flows through the supply flow path 2 and flows into the inlet opening 41 of the manifold valve 31 with the pressure adjusted by the constant pressure valve 22. The first valve 5 is opened when compressed air is supplied to the lower space 57a from a vent communicating with the lower space 57a. The liquid flowing into the inlet opening 41 flows into the first valve side valve chamber 36a from the inlet flow path side opening 34 via the inlet flow path 44. The liquid flowing into the first valve side valve chamber 36a flows from the communication flow path side first opening 39a to the communication flow path 38, and flows from the communication flow path side second opening 39b to the second valve side valve chamber 36b. The second valve 6 is closed because compressed air is not supplied to the vent hole communicating with the lower space 57b. Since the second valve body 81b has a smaller diameter than the second valve side valve chamber 36b, the liquid flows around the second valve body 81b and flows into the outlet channel 45 from the outlet channel side opening 46. The liquid that has flowed into the outlet channel 45 flows into the discharge channel 3 from the outlet opening 42 and is discharged from the discharge opening 13 onto the silicon wafer 12 at the use point 9. At this time, if the inner diameter of the outlet channel 45 is formed to be substantially the same as or larger than the inner diameter of the discharge channel 3, it is possible to make it difficult to form an air pool in the discharge channel 3.

  In the third embodiment, the communication channel 38 and the outlet channel 45 are connected on the same axis to the inner peripheral surface of the second valve side valve chamber 36b. A second valve seat 37b is formed at the peripheral edge of the branch flow path side opening 35 formed on the bottom surface of the second valve side valve chamber 36b. By forming the second valve seat 37b at the peripheral edge of the branch channel side opening 35, the liquid flows into the discharge channel 4 at the inlet of the branch channel 47, not in the middle of the branch channel 47, or is blocked or blocked. can do. Therefore, the flow path from the communication flow path 38 to the outlet flow path 45 is configured as a continuous flow path, and it is possible to prevent the occurrence of a portion where the liquid stays when the second valve 6 is closed.

  Next, the state of the liquid stop will be described with reference to FIGS. 3 and 4. When the supply of compressed air to the lower space 57a of the first valve 5 is stopped, the first piston 61a is urged downward by the spring disposed in the annular hole portion 55a of the first cylinder body 51a. The first valve 5 is closed. Since the flow rate adjusting valve 95 for adjusting the flow rate of the air exhausted from the lower space 57a is disposed at the vent communicating with the lower space 57a, the first piston 61a is gently seated on the first valve seat 37a. Can do. By gently seating the first piston 61a, the first piston 61a can be prevented from abruptly pushing out the liquid in the first valve side valve chamber 36a toward the communication flow path 38 side. The liquid can be prevented from being pushed out.

  Almost simultaneously with the operation of closing the first valve 5, compressed air is supplied to the lower space 57b from the vent communicating with the lower space 57b of the second valve 6, and the second valve 6 is quickly opened. At this time, since the liquid level formed in the discharge opening 13 is higher than the liquid level formed in the branch flow path side opening 35, the liquid existing in a full state downstream of the first valve body 81a is siphon. It flows into the branch channel 47 due to the effect. In the third embodiment, since the branch flow passage side opening 35 is opened before the first valve body 81a is seated on the first valve seat 37a, the branch is made before the first valve 5 is completely closed. A liquid flow flowing into the flow path 47 can be formed. By forming a flow that flows into the branch flow path 47 in advance, immediately after stopping the discharge, the liquid flowing toward the discharge opening 13 can be smoothly directed to the branch flow path 47 by inertia, and the liquid dripping from the discharge opening 13 Can be effectively prevented.

  When the second valve 6 is opened, the liquid level near the liquid discharge opening 13 in the discharge flow path 3 moves toward the discharge flow path 4. When the liquid level reaches the mounting position of the liquid level sensor 23, a detection signal is output to a control unit (not shown). When the control unit (not shown) receives the detection signal, the supply of the compressed air to the lower space 57b is stopped, and the second piston 61b is moved by the spring disposed in the annular hole 55b of the second cylinder body 51b. Is biased toward the second valve seat 37b. When the second piston 61b is pressed against the second valve seat 37b, the second valve 6 is closed. When the second valve 6 is closed, the liquid flow in the discharge flow path 3 stops, and the liquid level stops at the position where the liquid level sensor 23 is attached.

  The liquid that has flowed into the branch flow path 47 flows into the discharge flow path 4 from the branch opening 43 and flows into the liquid tank 7 through the discharge opening 14. At this time, the inner diameter of the branch channel 47 on the branch opening 43 side is smaller than the inner diameter of the second valve side valve chamber 36b, and the flow rate of the liquid flowing into the discharge channel 4 from the branch channel 47 is reduced. Yes. When the flow rate of the liquid flowing into the discharge flow path 4 from the branch flow path 47 is reduced, the flow of the liquid flowing through the discharge flow path 3 can be made gentle, so that the liquid surface can be prevented from being destroyed, and the liquid can be An effect can be made to act effectively. In the third embodiment, the diameter of the branch opening 43 side of the branch channel 47 is reduced, but an orifice plate may be disposed in the vicinity of the branch opening 43. In addition, when the inner diameter of the branch flow path 47 is formed to be substantially the same as or smaller than the inner diameter of the outlet flow path 45, the liquid easily flows when it flows into the branch flow path 47. Further, if the inner diameter of the branch flow path 47 is formed to be approximately the same as or larger than the inner diameter of the discharge flow path 4, an air pool is formed in the discharge flow path 4 when the liquid flows into the discharge flow path 4 from the branch flow path 47. Can be made difficult.

  Here, the second valve body 81 b of the second valve 6 is restricted from moving upward by the opening adjustment stem 91. The needle portion 84 b of the valve body portion 82 b of the second valve body 81 b is inserted into the branch flow path 47. By adjusting the insertion amount of the needle portion 84b into the branch flow path 47, the opening area of the branch flow path side opening 35 is adjusted, and the flow rate of the liquid from which the liquid flows into the discharge flow path 4 is adjusted. be able to. In the third embodiment, the flow rate of the liquid flowing through the discharge flow path 3 is reduced by reducing the flow rate of the liquid flowing from the discharge flow path 3 to the branch flow path 47 side. By slowing down the flow rate of the liquid flowing through the discharge flow path 3, it is possible to prevent the liquid surface from being destroyed and to effectively cause the siphon effect to act on the liquid. Further, by slowing down the flow rate of the liquid flowing through the discharge flow path 3, the management of the stop position using the liquid level sensor becomes easy and accurate. Further, by reducing the opening area of the branch flow path side opening 35, it is possible to prevent air from entering the second valve side valve chamber 36b from the branch flow path 47 when the second valve 6 is opened. it can.

  In the third embodiment, the opening adjustment stem 91 screwed to the second cylinder body 51b is moved up and down to the branch channel 47 of the needle portion 84b when the second valve 6 is opened. The amount of insertion is adjusted. Here, if a differential screw is configured by interposing a cylindrical body having screw portions with different pitches on the outer peripheral surface and the inner peripheral surface between the opening adjustment stem 91 and the second cylinder main body 51b, it becomes more precise. The opening area of the branch channel side opening 35 can be adjusted. Further, even when the opening adjustment stem 91 is not used, when the compressed air is supplied to the lower space 57b of the second valve 6, the needle portion 84b is supplied by supplying the compressed air via the electropneumatic regulator. Can be adjusted. When the electropneumatic regulator is used, the position of the needle portion 84b can be changed by remote control, so the position of the needle portion 84b can be easily changed depending on the liquid type.

  In the third embodiment, the discharge flow path 4 is connected to the manifold valve 31, but the discharge flow path 4 may not be provided if the liquid may be discharged directly to the outside of the manifold valve 31. In such a case, the branch flow path 47 of the manifold valve 31 also serves as the discharge flow path 4, the branch opening 43 serves also as the discharge opening 14, and the branch flow path side opening 35 serves also as the discharge flow path inlet side opening 15. . In the third embodiment, the bottom surface of the second valve side valve chamber 36b is formed flat. However, the concave shape is such that the bottom surface of the second valve side valve chamber 36b is recessed in the direction of the branch flow path side opening 35. Thus, the liquid may easily flow into the branch channel 47. Further, a groove is formed in the inner peripheral surface and the bottom surface of the second valve side valve chamber 36b so that a swirl flow is generated when the liquid flows from the second valve side valve chamber 36b to the branch flow path 47 side. Good. In the third embodiment, each of the outlet opening 42 and the branch opening 43 is provided on one surface. However, the outlet opening 42 and the branch opening 43 are provided on a plurality of surfaces of the valve body 32, respectively. Also good. By providing the outlet opening 42 and the branch opening 43 on a plurality of surfaces of the valve body 32, the discharge flow path 3 and the discharge flow path 4 can be arranged so that the siphon effect is more effectively exhibited.

  In the third embodiment, the valve body 32 is formed from one base block, but the valve bodies of two valves may be directly integrated. For example, one in which two valve bodies are joined by adhesion or welding, and one in which a ferrule provided on the valve body is connected by a clamp. In the third embodiment, both the first valve 5 and the second valve 6 are reversely operated (the valve is opened when the compressed air is supplied), but the normal operation ( The valve is closed when compressed air is supplied) or double acting (supplying is required for both opening and closing operations), and is not particularly limited. Further, as in the third embodiment, when the first valve 5 and the second valve 6 are integrally coupled to form one manifold valve 31, the operation of the first valve 5 and the second valve 6 is mechanically performed. It is preferable that the mechanism for interlocking the first valve 5 and the second valve 6 can be formed compactly when it is desired to be interlocked with each other. In the third embodiment, the state of liquid discharge and stop is the same as in the first embodiment and the second embodiment, and thus the description thereof is omitted. Moreover, since the effect | action which prevents the liquid dripping from the discharge opening 13 at the time of discharge stop is the same as that of 1st embodiment and 2nd embodiment, description is abbreviate | omitted.

-Fourth embodiment-
A liquid ejection apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram illustrating a schematic configuration of the liquid ejection apparatus according to the fourth embodiment. The fourth embodiment is different from the first embodiment in that the first valve 5 and the second valve 6 are replaced with one switching valve 101. In addition, the same code | symbol is attached | subjected to the location which has the same function as 1st embodiment, and the difference with 1st embodiment is mainly demonstrated below.

  The switching valve 101 is, for example, a three-way ball valve, and can switch the communication state of a plurality of flow paths with a single valve element. In the switching valve 101, the liquid can flow into the supply flow path 2 and the discharge flow path 3 but cannot flow into the discharge flow path 4, and the liquid cannot flow from the discharge flow path 3 to the discharge flow path 4. It is possible to switch between the two states of being able to flow from the supply flow channel 2 to the discharge flow channel 3 and the discharge flow channel 4. In the fourth embodiment, a three-way ball valve is used as the switching valve 101. However, a three-way butterfly valve or other known switching valve can be used as long as the communication state of a plurality of flow paths can be switched with one valve body. Well, not particularly limited.

  Next, the operation of the liquid ejection apparatus according to the fourth embodiment of the present invention will be described with reference to FIG.

  First, the state of liquid discharge will be described. When the switching valve 101 is in a state where the liquid can flow into the supply flow path 2 and the discharge flow path 3 but cannot flow into the discharge flow path 4, the liquid pumped by the liquid supply means 1 in FIG. And flow to the silicon wafer 12 from the discharge opening 13. When the switching valve 101 is switched to a state in which liquid can flow from the discharge flow path 3 to the discharge flow path 4 but cannot flow from the supply flow path 2 to the discharge flow path 3 and the discharge flow path 4, The supply of liquid from the channel 2 to the discharge channel 3 is stopped. Here, the liquid existing in a substantially full state in the discharge flow path 3 flows toward the discharge flow path 4 as indicated by the broken line arrow in FIG. 5 due to the siphon effect. In 4th Embodiment, since the effect | action which prevents the dripping from the discharge opening 13 at the time of discharge stop is the same as that of 1st Embodiment, description is abbreviate | omitted. In the fourth embodiment, by replacing the first valve 5 and the second valve 6 with one switching valve 101, the space for installing the valves can be reduced, and the operation of the valves is simplified. be able to.

  In the third embodiment, the material of the valve body 32, the cylinder bodies 51a and 51b, the pistons 61a and 61b, the diaphragm holders 71a and 71b, and the opening adjustment stem 91 in the manifold valve is suitable for the fluid and environment to be used. It is not particularly limited as long as it has physical properties, and may be a resin such as PTFE, polyvinyl chloride, polyvinylidene fluoride, polyethylene, PP, polystyrene, PFA, a metal or alloy such as iron or stainless steel, glass, etc., and is not particularly limited. .

  In the third embodiment, the material of the valve bodies 81a and 81b in the manifold valve is not particularly limited as long as it has physical properties suitable for the fluid and environment to be used, and a resin such as PTFE, polyvinyl chloride, or PFA. Elastomers such as fluorine rubber, silicon rubber, ethylene propylene diene rubber, nitrile rubber, butyl rubber, and acrylic rubber can be used and are not particularly limited.

  In the first to fourth embodiments, the liquid ejecting apparatus is a liquid ejecting apparatus for a semiconductor manufacturing apparatus, a photoresist liquid is shown as the liquid to be ejected, and the silicon wafer 12 is an object to eject liquid. Although it is shown, the usage is not particularly limited as long as it is a device that discharges liquid to an object. Other applications include applications for discharging chemicals and pharmaceuticals into various containers, applications for discharging drinking water and liquid food into various containers, and applications for discharging liquid detergents, shampoos and rinses into various containers.

  Note that the liquid ejection device may be configured by arbitrarily combining the first to fourth embodiments. That is, the present invention is not limited to the liquid ejection device according to the embodiment as long as the features and functions of the present invention can be realized.

DESCRIPTION OF SYMBOLS 1 Liquid supply means 2 Supply flow path 3 Discharge flow path 4 Discharge flow path 5 1st valve 6 2nd valve 13 Discharge opening 14 Discharge opening 15 Discharge flow path inlet side opening 23 Liquid level sensor 24 Flowmeter 31 Manifold valve 32 Valve Main body 34 Inlet channel side opening 35 Branch channel side opening 36a First valve side valve chamber 36b Second valve side valve chamber 38 Communication channel 41 Inlet opening 42 Outlet opening 43 Branch opening 44 Inlet channel 45 Outlet channel 46 Outlet channel side Opening 47 Branching flow path 51a First cylinder body 51b Second cylinder body 61a First piston 61b Second piston 71a First diaphragm holder 71b Second diaphragm holder 81a First valve body 81b Second valve body 82a, 82b Valve body part 83a 83b Diaphragm part 84b Needle part 91 Opening adjustment stem 95 Flow Regulating valve 101 switching valve

Claims (13)

In an apparatus for discharging a predetermined amount of liquid,
Liquid supply means for pumping the liquid;
A supply flow path connected to the liquid supply means;
A discharge flow path having a discharge opening for discharging the liquid;
A first valve connected to the supply flow path and the discharge flow path to open or block the flow of the liquid between the supply flow path and the discharge flow path;
A discharge flow path having a discharge opening for discharging the liquid;
A second valve connected to the discharge flow path and the discharge flow path, for opening or blocking the flow of the liquid between the discharge flow path and the discharge flow path;
With
The discharge opening is disposed at a position higher than the discharge opening,
The first valve blocks the flow of the liquid between the supply flow path and the discharge flow path, and the second valve opens the flow of the liquid between the discharge flow path and the discharge flow path. Then, the liquid filled in the discharge flow path so as to have a liquid level at the discharge opening flows to the discharge opening side by a siphon effect. The discharge channel is provided with an opening on the discharge channel inlet side to which the second valve is connected at the end,
The liquid discharge apparatus according to claim 1, wherein the discharge channel inlet side opening is disposed at a position lower than the discharge opening. The liquid ejection device according to claim 1, wherein the first valve and the second valve are integrally coupled and arranged as one manifold valve. The manifold valve is
A valve body,
A first valve side valve chamber;
A second valve side valve chamber;
The first valve side valve chamber is connected to the communication channel side first opening formed in the first valve side valve chamber and the communication channel side second opening formed in the second valve side valve chamber. A communication channel for communicating with the second valve side valve chamber;
An inlet channel connected to the inlet channel side opening formed in the first valve side valve chamber and the supply channel;
An outlet channel connected to the outlet channel side opening formed in the second valve side valve chamber and the discharge channel;
A branch channel connected to the branch channel side opening formed in the second valve side valve chamber and the discharge channel;
A valve body comprising:
A first valve body for opening and closing the inlet channel side opening or the communication channel side first opening;
A first drive unit for driving the first valve body;
A second valve body that opens and closes the branch channel side opening without blocking the communication channel and the communication state between the second valve side valve chamber and the outlet channel;
A second drive unit for driving the second valve body;
The liquid ejection device according to claim 3, wherein the liquid ejection device is provided. The liquid ejecting apparatus according to claim 4, wherein the second valve body has a tapered tip portion that tapers toward the opening on the branch flow path side. The valve body is formed from one base block;
The inlet channel side opening is opened and closed by a first valve body,
The inlet channel side opening is provided at the bottom center of the first valve side valve chamber;
The branch channel side opening is provided at the center of the bottom of the second valve side valve chamber;
The first drive unit and the second drive unit are arranged so that their respective axes are orthogonal to the flow channel axes of the communication flow channel and the outlet flow channel,
The branch flow path is disposed in a direction facing the second valve body across the flow path axis of the communication flow path and the outlet flow path;
The first drive unit is
A first cylinder extending vertically,
A first piston arranged to be movable up and down in the first cylinder;
With
The first piston is provided with a lower shaft portion that passes through a first diaphragm presser disposed on the valve body side of the first cylinder and is connected to the first valve body at a tip portion.
The first cylinder includes a space formed by the outside of the first cylinder, the upper end surface of the first diaphragm retainer, the inner peripheral surface of the first cylinder, and the lower end surface of the first piston, or the first cylinder A vent is provided in at least one of the space formed by the outside of the cylinder, the ceiling surface and inner peripheral surface of the first cylinder, and the upper end surface of the first piston,
The second drive unit is
A second cylinder extending vertically,
A second piston arranged to be movable up and down in the second cylinder;
With
The second piston is provided with a lower shaft portion that penetrates a second diaphragm presser disposed on the valve body side of the second cylinder and is connected to the second valve body at a tip portion.
The second cylinder includes a space formed by the outside of the second cylinder, the upper end surface of the second diaphragm retainer, the inner peripheral surface of the second cylinder, and the lower end surface of the second piston, or the second cylinder The vent hole is provided in at least one of the space formed by the outside of the cylinder, the ceiling surface and inner peripheral surface of the second cylinder, and the upper end surface of the second piston. Item 6. The liquid ejection device according to Item 5. The liquid ejection device according to claim 6, wherein a flow rate adjusting unit that adjusts a flow rate of air passing through the vent port is provided in the vent port of the first cylinder. The flow rate adjusting means for adjusting the flow rate of the liquid flowing from the discharge flow path toward the discharge flow path is provided in the manifold valve. The liquid discharge apparatus according to 1. The second valve is provided with an opening adjusting stem that is a flow rate adjusting means for adjusting the flow rate of the liquid flowing from the discharge flow channel toward the discharge flow channel,
The opening adjustment stem is:
Arranged in the second cylinder to be movable up and down,
A shaft portion having a male screw portion screwed with a female screw portion provided in the second cylinder, and an engagement portion that comes into contact with the upper end surface of the second piston when the second valve is opened. The liquid ejecting apparatus according to claim 6, wherein the liquid ejecting apparatus is provided. The liquid ejecting apparatus according to claim 1, wherein the first valve and the second valve are separate bodies and are spaced apart from each other. The first valve and the second valve are integrally coupled;
With one valve body, the liquid flow between the supply flow path and the discharge flow path is opened, and the liquid flow between the discharge flow path and the discharge flow path is blocked. The liquid flow between the supply flow channel and the discharge flow channel is blocked, and the liquid flow between the discharge flow channel and the discharge flow channel is switched to a state of being opened. The liquid discharge apparatus according to claim 1, wherein the liquid discharge apparatus is configured as a switching valve. At least one measuring instrument of a liquid level meter and a flow meter is arranged in the discharge channel or the discharge channel,
The said 2nd valve opens or interrupts | blocks the distribution | circulation of the said liquid between the said discharge flow path and the said discharge flow path based on the measurement result of the said measuring device. The Claim 1 or Claim 2 characterized by the above-mentioned. The liquid discharge apparatus as described. When the liquid filled in the discharge flow path so as to have a liquid level at the discharge opening flows to the discharge opening side by the siphon effect, the liquid level flows into the second valve before the second valve. The liquid discharge apparatus according to claim 1, wherein the two valves block the flow of the liquid between the discharge flow path and the discharge flow path.

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