JP7419115B2 - Processing equipment and switching valve unit - Google Patents

Description

The present invention is applicable to, for example, semiconductor wafers, substrates for liquid crystal display devices, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, and solar panels. The present invention relates to a processing device and a switching valve unit that process objects to be processed, such as battery substrates, with processing fluids such as chemical solutions and pure water.

Generally, in the manufacturing process of semiconductors, objects to be processed such as substrates are processed with various processing fluids. This process is performed, for example, in a single-wafer processing unit that has a vacuum chamber and processes substrates one by one. As described in Patent Document 2, this processing unit is equipped with a chamber, a substrate holding mechanism, a processing fluid supply section, a collection cup, etc., and during processing, the substrate is held horizontally by the substrate holding mechanism. After the substrate is in a rotating state, processing fluid is supplied from the processing fluid supply section to the substrate. The collection cup is provided so as to surround the substrate holding mechanism, and is configured to be able to collect processing fluid scattered from the rotating substrate. This collected processing fluid is collected under the collection cup by gravity, and is also discharged to the outside of the processing unit from the discharge port provided at the bottom of the collection cup through a drain pipe and an exhaust pipe. There is.

In many cases, it is necessary to use multiple types of processing fluids with greatly different characteristics.For example, after processing with an acid-based processing fluid, an atmosphere of this processing fluid is created in the exhaust pipe. If the next alkaline processing fluid is introduced into the chamber in a state in which some remains, the generation of salt will become a major cause of particle generation. For example, three types of processing fluids (SC1 (a mixture of ammonia, hydrogen peroxide, and water) as an acid-based chemical solution, and HF as an alkaline-based chemical solution) are used as multiple types of processing fluids with significantly different characteristics used in the process of cleaning wafers. There is a cleaning process using (hydrofluoric acid) and IPA (isopropyl alcohol) as an organic solvent.

In order to deal with the above problems, an exhaust switching unit is installed in the exhaust pipe connected to the processing chamber. A processing device is provided in which a valve box is connected in parallel to a distribution box, and switching valves each swinging in the exhaust direction are provided inside the switching valve box (Patent Document 1). Moreover, there is Patent Document 2 as an invention that obtains similar effects.

In the processing apparatus of Patent Document 1, as also shown in FIG. 10, an exhaust switching unit 102 is provided in an exhaust pipe 101 connected to the inside of a processing chamber 100. The exhaust gas switching unit 102 includes a distribution box 103, a switching valve box (not shown) that is hermetically connected to the distribution box 103, and an exhaust pipe 105 that is hermetically connected to the distribution box 103. The number of switching valve boxes corresponding to the types of processing fluids are connected in parallel to the distribution box 103, and inside the switching valve box there is a switching valve 106 that swings in the exhaust direction, and a switching valve 106 that swings in the exhaust direction. Relief valves (not shown) for introducing atmospheric air in intersecting directions are respectively provided. The exhaust switching unit 102 is configured by providing an exhaust pipe 105 at the end of the switching valve box in the exhaust direction, and the exhaust switching unit 102 is configured in multiple stages in a stacked state using a holder (not shown).

The substrate liquid processing apparatus of Patent Document 2 is equipped with an exhaust switching unit at a predetermined location, and this exhaust switching unit is provided for each exhaust introduction section into which exhaust from the exhaust pipe is introduced and for each individual exhaust pipe. The exhaust intake port that communicates with the exhaust inlet, the outlet that communicates with the individual exhaust pipe, the outside air intake that takes in outside air, and the communication status of the exhaust intake, outflow, and outside air intake. A plurality of switching mechanisms are provided, each having a valve body for switching between a state in which the mouth and the outflow port communicate with each other, or a state in which the outside air intake port and the outflow port communicate with each other.

Patent No. 6219848 Patent No. 6289341

However, in any of the conventional techniques, an exhaust mechanism including some kind of valve is provided between the exhaust duct and the exhaust pipe, and the processing fluid discharged into the duct is switched by opening and closing these valves. The inside of the duct becomes a negative pressure state due to exhaust suction, so as the valve for fluid switching is switched, pressure fluctuations also occur in the chamber that communicates with it, and if this pressure fluctuation is large, particles in the chamber It is necessary to suppress this pressure fluctuation as much as possible because the rise of the gas and convection become large and the high cleanliness inside the chamber is impaired.

In Patent Documents 1 and 2, as a countermeasure, it was necessary to include some kind of valve or piping for introducing outside air into the exhaust mechanism, and by introducing outside air through these, it was necessary to appropriately alleviate pressure fluctuations and the like. Therefore, there is a problem of increasing the size and complexity of the processing device.

Therefore, the present invention was developed to solve the above problems, and its purpose is to appropriately control pressure fluctuations within the processing chamber when discharging multiple types of processing fluids from the processing chamber. It is an object of the present invention to provide a simple and compact processing device and switching valve unit while ensuring control and reliable switching of multiple types of processing fluids.

In order to achieve the above object, the invention according to claim 1 includes: a chamber for processing an object with a plurality of types of processing fluids; and an exhaust pipe connected to the chamber and through which the plurality of processing fluids are exhausted from the chamber. , a branch duct connected to the exhaust pipe and corresponding to each type of processing fluid, a plurality of collective exhaust ducts connected to the branch duct and corresponding to each type of processing fluid handled, The exhaust duct includes a switching valve mechanism corresponding to each type of processing fluid handled in multiple types, and the switching valve mechanism includes a discharge valve body that discharges the processing fluid from the chamber into the collective exhaust duct, and a switching valve mechanism that discharges the processing fluid from the chamber into the collective exhaust duct. This processing device has a direct-acting structure in which it is connected to an introduction valve body that introduces outside air into the interior.

In the invention according to claim 2, the switching valve mechanism is a processing device that is attached to the inside of the collective exhaust duct while being inserted into the inside of the collective exhaust duct.

The invention according to claim 3 provides that the switching valve mechanism includes a holding plate having an outside air introduction port and a valve seat port, a direct-acting rod that penetrates approximately the center of the holding plate via an actuator and moves directly, The switching valve mechanism includes a discharge valve body provided on the tip side of the rod, and an introduction valve body provided on the direct-acting rod between the discharge valve body and the holding plate, and the switching valve mechanism includes at least the introduction valve body and the discharge valve body. This processing device has a valve body built into a collective exhaust duct, an inlet valve body and a discharge valve body facing each other, and is opened and closed in a direct-acting manner by a direct-acting rod.

The invention according to claim 4 is a processing device in which the discharge valve body and the introduction valve body are each provided with a needle portion for adjusting the flow rate.

In the invention according to claim 5, the discharge valve body is provided with a seal member for hermetically sealing the discharge port of the collective exhaust duct, and the inlet valve body is provided with a seal member for hermetically sealing the valve seat opening. This is the processing equipment provided.

The invention according to claim 6 is a switching valve unit including a plurality of collective exhaust ducts and a switching valve mechanism corresponding to each type of processing fluid handled in the collective exhaust duct, the switching valve mechanism comprising: A direct-acting structure is created by connecting the discharge valve body that discharges the processing fluid into the collective exhaust duct corresponding to each type of processing fluid that is handled, and the introduction valve body that introduces outside air into the collective exhaust duct. It is a switching valve unit.

In the invention according to claim 7, the switching valve mechanism is a switching valve unit that is attached to the inside of the collective exhaust duct while being inserted into the inside of the collective exhaust duct.

The invention according to claim 8 provides that the switching valve mechanism includes a holding plate having an outside air introduction port and a valve seat port, a direct-acting rod that penetrates approximately the center of the holding plate via an actuator and moves directly, It is equipped with a discharge valve body provided on the tip end side of the rod, and an introduction valve body provided on the direct-acting rod between the discharge valve body and the holding plate, and at least the introduction valve body and the discharge valve body are collectively exhausted. This is a switching valve unit that is built into a duct, has an inlet valve element and an outlet valve element facing each other, and is opened and closed in a direct-acting manner using a direct-acting rod.

The invention according to claim 9 is a switching valve unit in which the discharge valve body and the introduction valve body are each provided with a needle portion for adjusting the flow rate.

In the invention according to claim 10, the discharge valve body is provided with a seal member for hermetically sealing the discharge port of the collective exhaust duct, and the introduction valve body is provided with a seal member for hermetically sealing the valve seat opening. This is a switching valve unit provided.

According to the invention according to claim 1, the processing apparatus of the present invention includes a chamber for processing an object to be processed with a plurality of types of processing fluids, and an exhaust pipe connected to the chamber and through which the plurality of processing fluids are exhausted from the chamber. A branch duct connected to the exhaust pipe and corresponding to each type of processing fluid, and a switching valve mechanism connected to the branch duct and corresponding to each type of processing fluid handled. The switching valve mechanism has a direct-acting structure in which the discharge valve body that discharges the processing fluid from the chamber into the collective exhaust duct and the introduction valve body that introduces outside air into the collective exhaust duct are connected. A switching valve mechanism for exhausting the processing fluid is provided inside the plurality of collective exhaust ducts that connect to the processing fluid corresponding to the branch duct. Therefore, while ensuring appropriate suppression of pressure fluctuations in the processing chamber and reliable switching of multiple types of processing fluids, it is possible to almost eliminate the space occupied by the exhaust mechanism between the branch duct and the collective exhaust duct. In addition to this, it is also possible to significantly simplify the processing equipment. In particular, since the space occupied by the processing device becomes compact, production costs can be significantly improved.

Further, in the processing apparatus of the present invention, the switching valve mechanism directly connects the discharge valve body that discharges the processing fluid from the chamber into the collective exhaust duct and the introduction valve body that introduces outside air into the collective exhaust duct. By adopting a dynamic structure, the discharge valve body and the introduction valve body can be integrated into a single valve body, and their driving can be realized by simple linear movement using a single drive source (actuator), which makes it possible to use a switching valve mechanism. Along with the simplification, the exhaust sealing performance is also improved.

According to the invention according to claim 2, in the processing apparatus of the present invention, since the switching valve mechanism is installed inside the collective exhaust duct while being inserted thereinto, the switching valve mechanism can be provided in the collective exhaust duct by an insertion method. This makes attachment/detachment, replacement, and maintenance of the switching valve mechanism extremely easy.

According to the invention according to claim 3, in the processing apparatus of the present invention, the switching valve mechanism includes a holding plate having an outside air introduction port and a valve seat port, and a direct-acting valve mechanism that penetrates approximately the center of the holding plate via an actuator. A direct-acting rod, a discharge valve body provided on the tip side of the direct-acting rod, and an inlet valve body provided on the direct-acting rod between the inlet valve body and the holding plate, and at least the inlet valve The valve body and the discharge valve body are built into the collective exhaust duct, the inlet valve body and the discharge valve body are both facing each other, and the valve body is opened and closed in a direct-acting manner by a direct-acting rod, thereby reducing the space occupied by the switching valve mechanism. Specifically, between the chamber and the collective exhaust duct, the space occupied by the exhaust mechanism as in conventional technology can be almost eliminated, making it possible to significantly save space and significantly reducing the size of processing equipment. Simplification is also possible. In particular, since the space occupied by the processing device becomes compact, the production cost of the processing device is also reduced.

In addition, a switching valve mechanism is provided on a retaining plate having an outside air inlet and a valve seat opening, a direct-acting rod that penetrates approximately the center of the retaining plate via an actuator and moves directly, and a distal end of the direct-acting rod. The introduction valve body is an abbreviation of a retaining plate having an outside air inlet and a valve seat opening. Since it is provided on one side by directly moving a direct-acting rod through an actuator in the center, the introduction valve body can be opened and closed with a simple configuration.

According to the invention according to claim 4, since the discharge valve body and the discharge port are provided with the needle portion for adjusting the flow rate, it is possible to appropriately suppress and control the exhaust amount from the chamber, and therefore, the exhaust of the processing fluid can be properly suppressed and controlled. It is possible to reliably prevent pressure fluctuations within the chamber due to this.

According to the invention according to claim 5, since the discharge valve body and the introduction valve body are each provided with a sealing member capable of being hermetically sealed, it is possible to ensure reliable sealing performance between the valve seat port and the discharge port in the switching valve mechanism.

According to the invention according to claim 6, the switching valve unit of the present invention can provide a simple and compact switching valve unit while ensuring reliable switching of a plurality of types of processing fluids from a plurality of collective exhaust ducts.

According to the invention according to claim 7, the switching valve unit of the present invention is installed inside the collective exhaust duct with the switching valve mechanism inserted into the interior of the collective exhaust duct. This makes attachment/detachment, replacement, and maintenance of the switching valve mechanism extremely easy.

According to the invention according to claim 8, the switching valve unit of the present invention has both the inlet valve body and the discharge valve body facing each other by connecting to one driving source (actuator) that operates linearly, and the switching valve unit of the present invention is configured such that both the inlet valve body and the discharge valve body face each other by connecting to one driving source (actuator) that operates linearly. Since it opens and closes dynamically, the switching valve unit can be simplified and exhaust and outside air introduction can be linked together.

According to the invention according to claim 9, since the switching valve unit of the present invention is provided with a needle portion for adjusting the flow rate between the discharge valve body and the discharge port, it is possible to exhaust a plurality of types of processing fluids from a plurality of collective exhaust ducts. The amount can be appropriately suppressed and controlled, and therefore, pressure fluctuations in the chamber due to exhaustion of the processing fluid can be reliably prevented.

According to the invention according to claim 10, in the switching valve unit of the present invention, since the discharge valve body and the introduction valve body are each provided with a sealing member that can be hermetically sealed, the switching valve mechanism can securely connect the valve seat port and the discharge port. Sealing performance can be ensured.

FIG. 1 is an explanatory diagram schematically showing a processing device (switching valve unit) as an example of an embodiment of the present invention. 1 is a sectional view of a switching valve mechanism according to an example of an embodiment of the present invention. FIG. 1 is a perspective view schematically showing a switching valve mechanism according to an example of an embodiment of the present invention. (a) is a schematic diagram showing the external appearance seen from the outside air introduction side in FIG. 3, and (b) is a front view showing the shutter member. FIG. 2 is a cross-sectional view of the switching valve mechanism according to the embodiment of the present invention, with the discharge valve body closed. FIG. 2 is a sectional view of the switching valve mechanism according to an example of the embodiment of the present invention in an intermediate opening state. FIG. 3 is a cross-sectional view of the switching valve mechanism according to the embodiment of the present invention, with the introduction valve body closed. FIG. 7 is a cross-sectional view of another example of the switching valve mechanism according to the embodiment of the present invention. FIG. 7 is a cross-sectional view of another example of the switching valve mechanism according to the embodiment of the present invention, with the introduction valve body closed. FIG. 1 is an explanatory diagram schematically showing a processing device according to the prior art (Patent Document 1).

Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing a processing device 1 of an example of an embodiment of the present invention (hereinafter referred to as "this example"), and FIG. 2 is an exploded cross-sectional view of a switching valve mechanism 2 of this example. It is a diagram. 3 is a schematic perspective view showing a state in which the switching valve mechanism 2 of this example is built into the collective exhaust duct 7, and FIG. 4(b) is a front external view schematically showing the opening 10) as the front side, and FIG. 4(b) is a front external view showing the shutter member 16.

In FIG. 1, the processing apparatus 1 of this example includes a chamber 4 that processes an object to be processed (not shown) with a plurality of types of processing fluids, and a chamber 4 that is connected to the chamber 4 and from which the plurality of processing fluids are exhausted. an exhaust pipe 5, a branch duct 6 connected to the exhaust pipe 5 and corresponding to at least one of the plurality of types of processing fluids, and a processing fluid connected to the branch duct 6 and corresponding to the branch duct 6. A switching valve mechanism 2 for exhausting the air to a collective exhaust duct 7.

In FIG. 1, a chamber 4 schematically shown is a processing chamber for processing an object to be processed (not shown), and this processing includes, for example, cleaning processing for semiconductor wafers. In the case of this wafer cleaning process, for example, if a single wafer cleaning device is installed in the chamber 4, wafers can be loaded and unloaded one by one, and the wafers are placed on a rotating plate (not shown). is held rotatably in a horizontal plane. The chamber 4 contains an acidic processing liquid (for example, SPM), an alkaline processing liquid (for example, SC1), a rinsing liquid (for example, pure water), and an organic processing liquid (for example, for drying), which are not shown. In the cleaning process, each treatment liquid is applied from above to the wafer, which is held in a rotating state by a rotating plate, for example, acid treatment, rinsing treatment, alkali treatment, rinsing treatment, organic Liquid processing is performed by discharging the liquid in the order of processing and rinsing processing.

After the liquid processing using each liquid, the atmosphere of the liquid used for the liquid processing remains in the chamber 4 in the form of a mist. This ensures that the liquids are evacuated to the outside and that the liquids do not mix with each other in the chamber 4, exhaust pipe 5, etc. As described above, the meaning of the type of processing fluid in the present invention is at least that of the same type depending on whether or not it is necessary to perform exhaust treatment not in the same collective exhaust duct 7 (piping) but in separate collective exhaust ducts 7. If the fluid can be treated in the same exhaust gas duct 7, it means the same type of fluid, and if it needs to be treated in another exhaust gas duct 7, it means a different type of fluid. Therefore, in addition to cases in which acidic processing liquids, alkaline processing liquids, and organic processing liquids are treated as different types of processing fluids as described above, even if they have different characteristics, they can be exhausted using the same collective exhaust duct 7. The fluids may be treated as the same type. Furthermore, the term "fluid" is used in its general meaning, and includes, for example, not only a liquid state but also a mist-like or vaporized state.

Moreover, although FIG. 1 shows it schematically, as a specific configuration of the processing apparatus 1 of this example, for example, three collective exhaust ducts 7 are arranged in parallel. A branch duct 6 is formed on the side surface of the collective exhaust duct 7 in which the three collective exhaust ducts 7 are integrated in the intersecting vertical direction. The order in which the three collective exhaust ducts 7 are arranged is such that the branch duct 6 is configured in a three-pronged configuration, and the exhaust flow path from the chamber 4 (exhaust from the exhaust pipe 5 and the branch duct 6 to the collective exhaust duct 7) The distance on the exhaust flow path) is configured to be equal to all three collective exhaust ducts 7, or the exhaust flow path is arranged for alkaline fluid, organic fluid, and acidic fluid in the order of proximity to the chamber 4. It goes without saying that these can be arbitrarily selected depending on the implementation (order of cleaning processing, etc.).

In addition, in FIGS. 1 and 2, the switching valve mechanism 2 includes a discharge valve body 8 that discharges the processing fluid from the chamber 4 into the collective exhaust duct 7, and an introduction valve body 9 that introduces outside air into the collective exhaust duct 7. are connected to form a direct-acting structure. In this example, the specific configuration of the switching valve mechanism 2 is such that at least the introduction valve body 9 and the discharge valve body 8 are built into the collective exhaust duct 7, and both the introduction valve body 9 and the discharge valve body 8 are arranged on the main surface. The inlet valve body 9 opens and closes the valve seat opening 11, or the discharge valve body 8 directs the processing fluid from the chamber 4 to the collective exhaust duct 7. It is configured to open and close in a direct-acting manner so that the air can be discharged inside. Further, the switching valve mechanism 2 is installed inside the collective exhaust duct 7 for the corresponding processing fluid with the direct-acting rod 14 inserted into the collective exhaust duct 7, as shown in FIGS. 3 and 4, which will be described later. It will be done. The switching valve mechanism 2 in FIGS. 3 and 4 is schematically shown in such an inserted state.

By configuring the processing apparatus 1 as described above, it is possible to realize the processing apparatus 1 in which the exhaust switching structure from the chamber 4 to the collective exhaust duct 7 is compactly housed.

In particular, when compared with Patent Document 1 (prior art), the structure of the switching valve box in Patent Document 1 can be almost omitted in terms of occupied space, while the processing device 1 can be configured to ensure a reliable exhaust switching function. . Furthermore, even when compared with Patent Document 2, there is no need to adopt a complicated configuration such as the exhaust switching unit disclosed in the same document. In addition, the switching valve mechanism 2 has an inlet valve element 9 and an outlet valve element 8 built into the collective exhaust duct 7, with both the inlet valve element 9 and the outlet valve element 8 facing each other on their main surfaces, and opposed by a rod 14 that moves directly. The driving source moves in a direction perpendicular to the main surface so that the inlet valve body 9 opens and closes the valve seat port 11 or the discharge valve body 8 discharges the processing fluid from the chamber 4 into the collective exhaust duct 7. (Actuator) can also be reduced to just one.

FIG. 2 is an exploded sectional view showing the structure of the switching valve mechanism 2 of the present invention. The switching valve mechanism 2 includes a holding plate 12 having an outside air inlet 10 and a valve seat opening 11, a direct-acting rod 14 that penetrates approximately the center of the holding plate 12 via an actuator 13 and moves directly, and a direct-acting rod. and an introduction valve body 9 provided on the direct-acting rod 14 between the discharge valve body 8 and the holding plate 12. A direct-acting rod 14 that penetrates approximately the center of the holding plate 12 via an actuator 13 and moves directly, a discharge valve body 8 provided on the tip side of the direct-acting rod 14, and the discharge valve body 8 and the retaining plate 12. The inlet valve body 9 provided on the direct-acting rod 14 between the two is housed in the corresponding processing fluid collective exhaust duct 7. When the direct-acting rod 14 is reciprocated by the actuator 13, the introduction valve body 9 opens and closes the valve seat port 11, and the discharge valve body 8 opens the discharge port 17 for discharging the processing fluid from the chamber 4 into the collective exhaust duct 7. Opens and closes directly.

A switching valve unit 3 is shown in FIGS. The switching valve unit 3 of this example includes a plurality of types of collective exhaust ducts 7, and within these collective exhaust ducts 7, switching valve mechanisms 2 corresponding to each type of processing fluid handled.

Moreover, FIG. 3 is a perspective view schematically showing the switching valve mechanism 2 of this example. FIG. 4(a) is a schematic external view of the state shown in FIG. 3, viewed from the front from the outside air introduction side where the actuator 13 is provided, and FIG. FIG. 3 is a front view showing the member 16 alone.

2 to 4, the switching valve mechanism 2 is configured to be detachably attached to the collective exhaust duct 7 via a holding plate 12 (attachment/detachment mechanism) provided with an actuator 13. The configuration of the switching valve mechanism 2 can be arbitrarily selected depending on the implementation, as long as it can be installed in an appropriate pipe via a predetermined attachment/detachment mechanism.

In FIGS. 2 to 4, the holding plate 12 of this example has a substantially disc-shaped configuration, and includes a circular flange-shaped fixing part 12a and a short cylindrical fitting insertion part with a smaller diameter than the outer diameter of this fixing part 12a. 12b. An actuator 13 is provided approximately at the center of the fixed portion 12a, and an outside air inlet 10 is formed to penetrate the fixed portion 12a. Although the shape and position of the outside air inlet 10 can be arbitrarily selected depending on the implementation, in this example, the shape and position of the opening 16a formed in the shutter member 16 shown in FIG. Since they are formed to substantially coincide with each other, a substantially fan-shaped outside air inlet 10 is formed radially from the substantially central position where the actuator 13 is fixed.

In FIGS. 2 to 4, the fixing portion 12a can be detachably fixed to a holder 18 of substantially the same shape provided on the collective exhaust duct 7 via a bolt 33. A fitting insertion portion 12b is provided concentrically with the fixed portion 12a, and the outer diameter of the fitting insertion portion 12b is approximately the same as the inner diameter of the holder 18, and the cylindrical shape of the holder 18 is It is inserted and fitted into the inner peripheral surface of. In addition, in this example, the inner diameter of the fitting insertion portion 12b is ensured to be large enough to completely surround the outside air introduction port 10, which is opened concentrically with the retaining plate 12, on the inner diameter side, and the outside air introduction port 10 is The outside of the holding plate 12 and the inside diameter side of the fitting insertion portion 12b are communicated with each other. Note that an O-ring is provided as a sealing member between the fixed portion 12a and the holding body 18 to seal the inside and outside of the collective exhaust duct 7.

The end face side of the fitting insertion portion 12b that is inserted and fitted into the collective exhaust duct 7 is formed in a flat shape, and the sealing face 19 of the introduction valve body 9 is formed in an annular shape on this end face side. . The inner diameter side of this sealing surface 19 becomes a valve seat opening 11 that opens toward the inside of the collective exhaust duct 7.

In FIGS. 2 to 4, the collective exhaust duct 7 is formed with a substantially rectangular cross section in this example, and one piping is provided for each type of processing fluid that is handled as described above. It communicates in a sealed manner. The branch duct 6 opens into the collective exhaust duct 7 through a discharge port 17, so that the processing fluid from the chamber 4 can be discharged.

In addition, processing fluids used in semiconductor manufacturing processes are often highly corrosive, so it is preferable to use non-metallic materials as much as possible for piping members that come into direct contact with the exhaust gas. The exhaust duct 7 is made of a predetermined transparent resin. Furthermore, as will be described later, the direct-acting rod 14, discharge valve body 8, introduction valve body 9, etc., which are directly exposed to the process fluid to be exhausted, are also made of resin as appropriate to prevent exhaust gas from entering during operation. It is preferable that metal members that are likely to be exposed to gas are provided with a sealing member as much as possible to block the exhaust gas.

Here, in this example, as described above, the actuator 13 is provided which penetrates the approximately central position of the holding plate 12 and directly moves the direct-acting rod 14. Since it is a type that is inserted into the air, at least the center of the outside air introduction side is blocked. On the other hand, in order to cause the exhaust air from the chamber 4 and the outside air from the outside to flow into one common collective exhaust duct 7 due to the action described later, in FIG. It is preferable that the total area of the openings 10) and the opening area of the exhaust gas introduction (the area of the exhaust ports 17) are equal.

Therefore, in order to compensate for the reduction in outside air introduction due to the presence of the actuator 13, in this example, the inner diameter of the discharge port 17 is set in advance to be smaller than the inner diameter on the outside air introduction side, that is, the inner diameter of the fitting insertion part 12b. In addition, the outside air introduction amount and the exhaust gas introduction amount are adjusted to be approximately equal by adjusting the area of the outside air introduction port 10 and the like. Specifically, by forming an inner peripheral tapered surface 11a (tapered portion) on the inner diameter side of the valve seat port 11, the diameter of which decreases toward the opening side of the valve seat port 11, the opening area for introducing outside air is adjusted. That's what I do.

In FIGS. 2 to 4, the actuator 13 can be implemented as long as both the inlet valve body 9 and the discharge valve body 8 face each other on their main surfaces, and the direct-acting rod 14 can be appropriately driven in a direction perpendicular to the opposing main surfaces. Although it can be selected arbitrarily depending on the situation, in this example, an air cylinder mechanism 13 that is driven by supplying and exhausting compressed air is used. The actuator 13 of this air cylinder mechanism has a piston 20, a piston rod 21 connected to the piston, a housing 37, and a cylinder 22, and the switching valve mechanism 2 is built in the collective exhaust duct 7. In this case, an elongated cylindrical housing 37 is fixed and protrudes outward concentrically with the fixing portion 12a, and an elongated cylindrical cylinder 22 is protruded and fixed inward. The piston rod 21 is inserted through the fixed portion 12a and driven concentrically inside the housing 37 and the cylinder 22. Note that since the piston rod 21 in this example is made of metal, an O-ring 23 is provided on the inner peripheral surface of the cylinder 22 in order to seal the processing fluid within the collective exhaust duct 7.

In FIG. 2, an air port 24a communicates with the air chamber 24, an air port 25a communicates with the air chamber 25, and the air chambers 24 and 25 are sealed with each other via the piston 20. As will be described later, when compressed air is supplied from a driving air supply source (not shown) to the air chamber 24 through the air port 24a, the piston 20 slides on the cylindrical inner peripheral surface of the cylinder 22, and this movement Accordingly, the piston rod 21, the direct-acting rod 14, and the two valve bodies (discharge valve body 8, introduction valve body 9) fixed thereto are integrally driven toward the discharge port 17 side.

2 to 4, in the switching valve mechanism 2, an actuator 13 causes the discharge valve body 8 and the introduction valve body 9 to face each other on their main surfaces, and is driven by a direct-acting rod 14 in a direction perpendicular to the opposing main surfaces. Ru. In this example, a direct-acting rod 14 is linearly connected to the piston rod 21, and a discharge valve body 8 is fixed to one end of the direct-acting rod 14 concentrically with the direct-acting rod 14.

In this example, the introduction valve body 9 is provided in a substantially disc shape with the same diameter as the discharge valve body 8, and is directly movable with respect to the discharge valve body 8 via three connecting rods 28 provided at axially symmetrical positions. It is fixed concentrically to the other end side (tip side) of the rod 14. A circular opening is provided at the center of the introduction valve body 9, and a cylinder 22 is slidably inserted into this opening, and serves as a sliding portion with the cylindrical outer peripheral surface of the cylinder 22. An O-ring 29 is provided on the inner peripheral surface of the opening. The introduction valve body 9 is fixed concentrically to the other end of the direct-acting rod 14. In the example of the present invention, the distance between the discharge valve body 8 and the introduction valve body 9 is maintained.

Note that the O-rings 26 and 30 used for sealing the valve body may be at least sealing members that can hermetically seal the discharge port 17 and the valve seat port 11 through surface contact with a planar seal surface, respectively. For example, in addition to an O-ring, an annular sealing member made of resin or metal that has high corrosion resistance, durability, and good adhesion and separation properties may be used.

A discharge valve body 8 and an introduction valve body 9 are configured such that both the introduction valve body 9 and the discharge valve body 8 face each other on their main surfaces, and are opened and closed in a direct-acting manner by a direct-acting rod 14 in a direction perpendicular to the opposing principal surfaces. stroke on the same axis. In the structure of this example, it is determined by the relationship between the length of the direct-acting rod 14 (or the distance between the discharge valve body 8 and the introduction valve body 9) and the distance between the valve seat port 11 and the discharge port 17. In the example, it is provided at about 47 mm. In addition, in this example, both the discharge valve body 8 and the introduction valve body 9 are stroked so that the projected area due to the stroke is larger than the valve opening area, that is, the total area of the outside air intake port 10 and the area of the discharge port 17. is ensured. The projected area by the stroke of the valve body in this example means the cylindrical area area that the outer peripheral side of the disk-shaped valve body sweeps over the entire stroke range. The distance between the introduction valve body 9 and the discharge valve body 8 is set shorter than the distance between the valve seat opening 11 and the discharge port 17.

In FIGS. 3 and 4, the shutter member 16 is an example of a means that can adjust the opening area of the outside air inlet 10 as appropriate, and other than such a shutter structure can be arbitrarily selected according to the implementation, but the present invention is not limited to this. In the example, a shutter member 16 formed in the shape of a substantially circular plate is used, and is integrally formed of a predetermined resin. The outer diameter of this shutter member 16 is larger than the outer diameter of the outer circumference of the outside air inlet 10, and is fixed by four thumb screws 31 provided at symmetrical positions so as to cover the outside air inlet 10. It is removably fixed concentrically to the outside of the portion 12a. FIG. 4(a) is a front view of this fixed state. Further, FIG. 4(b) is an external view showing the single shutter member 16. As shown in FIG.

Specifically, the outer peripheral edge of the shutter member 16 is tightened and fixed with a disc-shaped washer of a thumbscrew 31, and this fixed state can be achieved by fixing the shutter member 16 with at least four symmetrical thumbscrews 31. Even if the screw 31 is loosened, the shutter member 16 can be shifted in the circumferential direction without completely coming off the fixed part 12a. Further, as described above, in this fixed state, the shutter member 16 is also formed with an opening 16a so as to substantially match the shape and position of the outside air inlet 10. The same number of openings 16a having substantially the same shape are formed at the same position.

As shown in FIG. 4(b), a grip portion 16b is formed protruding from a part of the shutter member 16, and when it is fixed to the fixing portion 12a with a thumbscrew 31, as shown in FIG. 4(a). Thus, the grip portion 16b is in a state of protruding toward the outer periphery. When adjusting the amount of outside air introduced, after loosening the thumbscrew 31 that has been tightened and releasing the fixation of the shutter member 16, grasp this grip part 16b and move it in the circumferential direction of the circular shutter member 16. With this movement, the area of the overlapping area (outside air communication area) between the opening 16a and the outside air inlet 10 can be increased or decreased, so that the amount of outside air introduced can also be adjusted in accordance with this increase or decrease. Specifically, a gripping portion 16b protrudes between the bolts 33, and by moving the gripping portion 16b in the circumferential direction during this time, the degree of overlap between the opening 16a and the outside air inlet 10 is adjusted from 0 to 100%. can do. Therefore, at a position where the opening 16a does not completely overlap the outside air inlet 10, the outside air inlet 10 can be completely closed off by the shutter member 16.

In addition, since the discharge valve body 8 and the introduction valve body 9 are direct-acting type, it is not possible to close the discharge port 17 and the valve seat port 11 at the same time only by driving the actuator 13 as described later. If they are blocked at the same time, for example, as described later, after keeping the discharge valve body 8 in a fully closed state (while keeping the introduction valve body 9 in a fully open state), adjust the shutter member 16 to open the opening 16a. By fully closing the switching valve mechanism 2, the outside air and the inside of the switching valve mechanism 2 can be completely shut off.

Next, the operation of this example described above will be explained. 5 to 7 are cross-sectional views showing the operation of the switching valve mechanism 2, which is an example of an embodiment of the present invention. Note that these FIGS. 5 to 7 and FIGS. 8 and 9, which are other examples (hereinafter referred to as "other examples") of the embodiment of the present invention described later, are shown along A-A in FIG. 4(a). It corresponds to line cross section. Note that, based on the viewpoint seen from the bottom of FIGS. 5 to 9, which is the outside air introduction side, the upper side of the figure is called the push side, and the lower side of the figure is called the pull side. The closing direction is as if pushing toward the duct 7, and the pull side is the opening direction as pulling out the exhaust valve body 8 from the collective exhaust duct 7.

FIG. 5 shows the discharge valve body 8 in a closed state and the introduction valve body 9 in an open state. In this state, the O-ring 26 is in close contact with the sealing surface 27 to seal the exhaust port 17, and the exhaust fluid from the branch duct 6 cannot flow into the collective exhaust duct 7. In this situation, for example, in a chamber (not shown) communicating with the branch duct 6 in FIG. 5, the object to be processed is being processed using a different type of processing fluid than that corresponding to the collective exhaust duct 7 in the figure. Respond to the situation.

Here, as shown in FIG. 1, one collective exhaust duct 7 includes a plurality of chambers 4, an exhaust pipe 5 that connects to the chamber 4 and exhausts the processing fluid, each chamber 4, and each exhaust pipe 5. It is connected via a branch duct 6 communicating with the chamber 4 and a switching valve mechanism 2, and the processing is appropriately controlled for each chamber 4. Further, each collective exhaust duct 7 is provided with a negative pressure source such as an exhaust pump (not shown) to suck the exhaust fluid in the collective exhaust duct 7 in the exhaust direction. In addition, in FIG. 1, it is schematically shown that the X direction indicated by the arrow extending upward from each collective exhaust duct 7 is the exhaust direction, and in this case, the X direction pointed by the arrow is the downstream direction of the exhaust A negative pressure source (not shown) is appropriately provided on the downstream side.

The processing apparatus 1 is configured as described above, and in order to improve processing efficiency, basically, one collective exhaust duct 7 is connected to the chamber 4 in which processing is performed with the corresponding type of processing fluid. The switching valve mechanism 2 is always in communication with the discharge valve body 8, so that one of the discharge valve bodies 8 is always in an open state. On the other hand, in the switching valve mechanism 2 connected to the chamber 4 where processing with a different type of processing fluid is being performed, the discharge valve body 8 is closed, but the introduction valve body 9 is opened and communicated with the outside air. There is. Therefore, in the collective exhaust duct 7, through the discharge valve body 8 and the introduction valve body 9 which are opened in this way, there is air in the direction of the negative pressure source, with the inside of the chamber undergoing exhaust processing or the outside air side being upstream. A steady exhaust flow is formed towards the In the processing device 1 of the present invention, it is possible to appropriately suppress the influence of the opening/closing operation of the valve body associated with exhaust switching on the exhaust flow that is always formed in the collective exhaust duct 7.

Therefore, in FIG. 5, since the introduction valve body 9 is fully open, outside air is introduced into the collective exhaust duct 7 via the outside air introduction port 10 and the valve seat opening 11. In FIG. 5, the direction in which outside air is introduced is schematically shown by an arrow Y. Specifically, in this example, after the outside air is introduced from the valve seat port 11 into the collective exhaust duct 7, (This is the direction indicated by the white arrow, and corresponds to the X direction indicated by the arrow in FIG. 1).

In this example, the actuator 13 of one air cylinder mechanism is used as the drive source of the direct-acting rod 14, and when closing the discharge valve body 8 to the push side, the air is compressed into the air chamber 24 through the air port 24a. Air is supplied to drive the piston 20 to the push side, and air is discharged from the air chamber 25 on the pull side via the air port 25a. Conversely, when closing the introduction valve body 9 to the pull side, compressed air is supplied to the air chamber 25 on the pull side (upper side in the figure) via the air port 25a to drive the piston 20 to the pull side, and the piston 20 is driven to the pull side. Air is discharged from the air chamber 24 through the air port 24a.

It is preferable that the actuator 13 of the air cylinder mechanism be configured to be able to be automatically controlled via an appropriate control mechanism (not shown). , the introduction valve body 9) is preferably provided with a position detection function. Specifically, the system is equipped with a sensor that can detect the position of any driving part (discharge valve body 8, introduction valve body 9, direct-acting rod 14, etc.) with the fully closed position of the introduction valve body 9 as the origin. This is preferable because it becomes easier to appropriately detect atmosphere leakage from the chamber 4.

Next, FIG. 6 shows the discharge valve body 8 being opened, and thus the discharge valve body 8 and the introduction valve body 9 are both open. This situation can occur, for example, after a process is performed in the chamber 4 of FIG. 1 that communicates with the branch duct 6 of FIG. This corresponds to a situation in which the air is exhausted to the collective exhaust duct 7 in the figure via the exhaust pipe 5 and the branch duct 6.

Next, FIG. 7 shows the inlet valve body 9 in a fully closed state, and therefore the discharge valve body 8 in a fully open state. In this state, the O-ring 30 shown in FIG. 2 is in close contact with the sealing surface 19 to seal the valve seat port 11, and the outside air from the outside air inlet 10 cannot flow into the collective exhaust duct 7. In this state, a type of processing fluid corresponding to the collective exhaust duct 7 in the figure is exhausted from a chamber (not shown) communicating with the branch duct 6 in the figure, via the exhaust pipe 5 and the branch duct 6. I can do it. In the same figure, the introduction direction of the exhausted processing fluid is schematically shown by an arrow Z, and after being introduced into the collective exhaust duct 7 from the discharge port 17, as shown in the figure, The gas is exhausted in the penetrating direction (the direction indicated by the white arrow, which corresponds to the X direction indicated by the arrow in FIG. 1).

Here, in order to suppress pressure fluctuations in the internal space of the chamber 4 when the processing fluid in the chamber 4 is evacuated, that is, when the chamber 4 is opened or closed in a sealed state, it is necessary to at least communicate directly with the inside of the chamber 4. It is effective not to disturb the steady state of the exhaust gas flow formed in the collective exhaust duct 7. Due to the configuration of the processing apparatus 1 described above, in each switching valve mechanism 2, the processing fluid exhausted from the chamber 4 via the discharge valve body 8 or the outside air via the introduction valve body 9 is included in this exhaust flow. It's constantly flowing in. Therefore, by suppressing fluctuations in the inflow amount during exhaust processing to open and close these valve bodies, pressure fluctuations in the collective exhaust duct 7 can be effectively suppressed, and therefore, the pressure fluctuations in the chamber 4 It also greatly contributes to suppressing internal pressure fluctuations.

In order to suppress fluctuations in the inflow amount, it is important to keep the cross-sectional area of the inflow passage substantially constant before and after opening and closing the discharge valve body 8 and the introduction valve body 9, at least structurally. This is effective in ensuring the stability of the exhaust fluid inside the tank. In the switching valve mechanism 2, this inflow passage cross-sectional area is the sum of the inflow passage areas of the discharge valve body 8 and the introduction valve body 9, and specifically, This is the sum of the projected area formed by the valve body 8 and the sealing surface 27 and the projected area formed by the introduction valve body 9 and the sealing surface 19.

In the present invention, the discharge valve body 8 and the introduction valve body 9 are opposed to each other on their main surfaces, and the actuator 13 moves the direct-acting rod 14 in a direction perpendicular to the opposed main surfaces. Furthermore, preferably, if the opening areas of the discharge port 17 and the valve seat port 11 are configured to be approximately the same as shown in FIGS. 5 to 7, the direct-acting rod 14 is driven as shown in FIGS. During this period, the cross-sectional areas of the inflow passages on the discharge port 17 side and the valve seat port 11 side are always maintained in a trade-off relationship with each other, and the flow rate of the fluid flowing in from these can also be kept approximately constant. .

As described above, in the switching valve mechanism of the present invention, by keeping the total cross-sectional area of the flow paths leading to the collective exhaust duct constant, and thereby keeping the total inflow amount approximately constant, the exhaust fluid in the collective exhaust duct is kept constant. This is intended to effectively suppress pressure fluctuations. Moreover, the introduction valve body 9 and the discharge valve body 8 are built into the collective exhaust duct 7, the introduction valve body 9 is provided in the shape of a disk with the same diameter as the discharge valve body 8, and three connections are provided at axially symmetrical positions. Since the other end of the direct-acting rod 14 is concentrically fixed to the discharge valve body 8 via the rod 28, the introduction valve body 9 and the discharge valve body 8 are both opposed to each other, and the direct-acting rod 14 is fixed to the discharge valve body 8 via the rod 28. Since it can be opened and closed symmetrically, it has good operability as a switching valve.

Note that when the processing fluid or outside air flows into the exhaust flow formed in the collective exhaust duct 7 from the discharge valve element 8 or the introduction valve element 9, the flow of the processing fluid or outside air is further reduced as much as possible. It is more preferable if the configuration is such that it can join the flow as smoothly as possible without disturbance. In particular, it is preferable to have a structure that prevents fluid from suddenly flowing into the collective exhaust duct 7 when the valve body opens, and can appropriately suppress the fluid from flowing at this time. Therefore, in addition to the needle portion 35 described later, structural improvements may be made to guide the inflowing fluid, such as a mist trap or a guide plate provided at a predetermined structure and position.

Next, the structure of another example of the switching valve mechanism of the present invention will be explained. FIGS. 8 and 9 are sectional views showing another example of the switching valve mechanism 2, and the discharge valve body 8 of this switching valve mechanism 2 is connected to the discharge valve body 8 and the discharge port 17 for adjusting the flow rate. A needle portion 35 is provided on the main surface facing the discharge port 17 or the valve seat port 11, respectively. In this figure, the same parts as those of the switching valve mechanism 2 of the present example (FIGS. 2 to 7) described above are given the same reference numerals, and the explanation thereof will be omitted. Further, the driving action of the direct-acting rod 14 by the actuator 13 and the opening/closing action of the discharge valve body 8 and the introduction valve body 9 are the same as in this example described above.

In FIGS. 8 and 9, the needle part 35 is integrally formed in a substantially disk shape, the tip part has an outer diameter smaller than the inner diameter of the discharge port 17, and the side facing the discharge valve body 8 is the outer diameter of the discharge valve body 8. It is fixed concentrically to the ring 26 side, and specifically has a hollow cup shape. Specifically, in this other example, a bolt located at the center is inserted concentrically into the tip of the direct-acting rod 14 and fixed thereto. Further, the needle portion 35 is formed with an outer circumferential tapered surface 36 (tapered portion) whose diameter decreases toward the discharge port 17 side in this fixed state. Since the needle portion 35 is tapered, the degree of sealing between the discharge valve body 8 (outer circumferential tapered surface 36) and the sealing surface 27 is further increased. By forming the taper, it is possible to prevent exhaust gas from remaining between the sealing surface 27 and the exhaust valve body 8 and crystallizing the exhaust gas within the collective exhaust duct 7. This eliminates the need for long-term maintenance. Moreover, the taper makes it difficult for positional deviation to occur when the sealing surface 27 is inserted into the discharge valve body 8 even in a structure in which the shaft of the direct-acting rod is supported by only one side. In addition, although the needle part 35 is configured separately from the discharge valve body 8 in the figure, its configuration may be modified depending on the implementation, such as being configured integrally with the discharge valve body 8. It can be selected arbitrarily.

As shown in FIGS. 8 and 9, this outer circumferential tapered surface 36 alleviates changes in the flow path cross-sectional area between the outer circumferential tapered surface 36 and the sealing surface 27 when opening or closing the discharge valve body 8. Therefore, when the discharge port 17 is opened or closed by movement of the discharge valve body 8 with respect to the sealing surface 27, fluctuations in the amount of exhaust gas flowing from the branch duct 6 to the collective exhaust duct 7 can be further appropriately alleviated. Therefore, pressure fluctuations within the collective exhaust duct 7 can be suppressed. If this needle portion 35 is not provided, the inflow amount fluctuation during opening and closing may become even more rapid.

Furthermore, even at an intermediate opening degree as shown in FIG. 6, even if the pressure fluctuation in the collective exhaust duct 7 is large due to the force of the inflow fluid from the discharge port 17, the pressure fluctuation shown by the arrow in FIGS. As described above, this inflowing fluid hits the needle portion 35 (outer peripheral tapered surface 36) and is smoothly guided into the collective exhaust duct 7, so that pressure fluctuations can be suppressed without disturbing the inside of the collective exhaust duct 7. Although not shown, a needle member configured similarly to this needle portion 35 may be fixed to the introduction valve body 9.

That is, it can be fixed concentrically with the introduction valve body 9, and in this fixed state, the needle member having an outer peripheral tapered surface whose diameter decreases toward the valve seat port 11 side is moved toward the O-ring 30 side of the introduction valve body 9. If it is fixed, the inflow of outside air through the outside air inlet 10 can be relaxed into a smooth flow similar to the above-mentioned inflow of exhaust gas, and pressure fluctuations can also be suppressed. Furthermore, by suppressing pressure fluctuations, it is also possible to suppress rapid inflow and outflow of fluid through the outside air inlet 10 when the inlet valve body 9 is opened and closed. It is also possible to appropriately suppress the phenomenon of leakage to the outside when the body 9 is opened.

Furthermore, the present invention is not limited to the description of the embodiments described above, and various changes can be made without departing from the gist of the invention as set forth in the claims of the present invention.

1 Processing device 2 Switching valve mechanism 3 Switching valve unit 4 Chamber 5 Exhaust pipe 6 Branch duct 7 Collective exhaust duct 8 Discharge valve body 9 Introduction valve body 10 Outside air inlet 11 Valve seat opening 12 Holding plate 13 Actuator 14 Direct-acting rod 17 Exhaust Outlet 26 30 O-ring (sealing member)
35 Needle part

Claims (10)

a chamber for processing an object with a plurality of types of processing fluids; an exhaust pipe connected to the chamber and through which the plurality of types of processing fluids are exhausted from the chamber; and an exhaust pipe connected to the exhaust pipe and the plurality of types a branch duct corresponding to each type of processing fluid, a plurality of collective exhaust ducts connected to the branch duct and corresponding to each type of processing fluid handled by the plurality of types, and a plurality of types of processing fluid in the collective exhaust duct. a switching valve mechanism corresponding to each type of processing fluid to be handled; the switching valve mechanism includes a discharge valve body that discharges the processing fluid from the chamber into the collective exhaust duct; and a discharge valve body that discharges the processing fluid from the chamber into the collective exhaust duct. A processing device characterized by having a direct-acting structure connected to an introduction valve body for introducing outside air. The processing apparatus according to claim 1, wherein the switching valve mechanism is installed inside the collective exhaust duct while being inserted into the collective exhaust duct. The switching valve mechanism includes a holding plate having an outside air inlet and a valve seat opening, a direct-acting rod that penetrates approximately the center of the holding plate via an actuator and moves directly, and a distal end of the direct-acting rod. and an introduction valve body provided on the direct-acting rod between the discharge valve body and the holding plate, and the switching valve mechanism includes at least the introduction valve body and the introduction valve body. 3. The processing apparatus according to claim 2, wherein a discharge valve body is built in the collective exhaust duct, the introduction valve body and the discharge valve body are both opposed to each other, and are opened and closed in a direct motion manner by the direct motion rod. 4. The processing apparatus according to claim 3, wherein the discharge valve body and the introduction valve body are each provided with a needle portion for adjusting the flow rate. Claim: The discharge valve body is provided with a seal member for hermetically sealing the discharge port of the collective exhaust duct, and the introduction valve body is provided with a seal member for hermetically sealing the valve seat opening. 4. The processing device according to 3 or 4. In a switching valve unit comprising a plurality of collective exhaust ducts and a switching valve mechanism corresponding to each type of processing fluid handled in the plurality of types in the collective exhaust duct, the switching valve mechanism is configured to handle the plurality of types of processing fluid. A discharge valve body for discharging the processing fluid into the corresponding collective exhaust duct for each type of processing fluid and an introduction valve body for introducing outside air into the collective exhaust duct are connected to form a direct acting structure. Features switching valve unit. The switching valve unit according to claim 6, wherein the switching valve mechanism is installed inside the collective exhaust duct while being inserted into the collective exhaust duct. The switching valve mechanism includes a holding plate having an outside air inlet and a valve seat opening, a direct-acting rod that penetrates approximately the center of the holding plate via an actuator and moves directly, and a distal end of the direct-acting rod. and an introduction valve body provided on the direct-acting rod between the discharge valve body and the holding plate, and at least the introduction valve body and the discharge valve body are collectively exhausted. 7. The switching valve unit according to claim 6, wherein the switching valve unit is built in a duct, the introduction valve element and the discharge valve element are both opposed to each other, and are opened and closed in a direct-acting manner by the direct-acting rod. 9. The switching valve unit according to claim 8, wherein the discharge valve body and the introduction valve body are each provided with a needle portion for adjusting the flow rate. Claim: The discharge valve body is provided with a seal member for hermetically sealing the discharge port of the collective exhaust duct, and the introduction valve body is provided with a seal member for hermetically sealing the valve seat opening. 10. The switching valve unit according to 8 or 9.

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