Valve device and purge method for valve device

Abstract

According to the present invention, in a valve device (manifold valves (2A, 2B)) including a primary flow passage (10) and a secondary flow passage connected to the primary flow passage (10), the secondary flow passage includes at least two first secondary flow passages (secondary fluid supply passages (11A-11D)) connected to the primary flow passage sequentially from upstream to downstream of the primary flow passage (10), and at least two second secondary flow passages (purge flow passages (12A-12D)) connected to the primary flow passage (10) sequentially from upstream to downstream of the primary flow passage (10) on the opposite side from the first secondary flow passages (secondary fluid supply passages (11A-11D)), across the primary flow passage (10).

Description

Valve device and purging method for valve device

[0001] The present invention relates to a valve device including a main flow path and at least two sub flow paths sequentially connected to the main flow path from an upstream side to a downstream side of the main flow path, the valve device causing a secondary fluid to merge from the sub flow paths into a main fluid flowing through the main flow path, and to a purging method for such a valve device.

[0002] In semiconductor manufacturing processes (for example, wafer cleaning and etching processes), a solution obtained by mixing a chemical liquid into pure water is used, and the type of the chemical liquid mixed into the pure water is switched according to the process stage. Accordingly, a valve device that can selectively cause a chemical liquid corresponding to a process stage, selected from among a plurality of types of chemical liquids, to merge with pure water and output the mixture is used. A more specific description will be given below with reference to FIG. 9. FIG. 9 is a simplified diagram illustrating a valve device 50 according to a conventional technology.

[0003] The valve device 50 shown in FIG. 9 includes a main flow path 55 for allowing a main fluid (pure water in this case) to flow therethrough. A plurality of sub flow paths 52A to 52C for introducing a secondary fluid (a chemical liquid in this case) into the main flow path 55 are connected to the main flow path 55. Note that three sub flow paths are connected herein. Connection portions (openings 53A to 53C) where the sub flow paths 52A to 52C are connected to the main flow path 55 can be respectively opened and closed by valve bodies 54A to 54C. Therefore, the chemical liquid is introduced into the main flow path 55 when the openings 53A to 53C are opened, and introduction of the chemical liquid into the main flow path 55 is blocked when the openings 53A to 53C are closed by the valve bodies 54A to 54C. The type of the chemical liquid introduced into the main flow path 55 is different for each of the sub flow paths 52A to 52C, and a necessary chemical liquid is introduced into the main flow path 55 from among the chemical liquids supplied by the respective sub flow paths 52A to 52C according to the process stage, and is caused to merge with the pure water. That is, for example, when the chemical liquid in the sub flow path 52A is required, by opening the opening 53A and closing the other openings 53B and 53C, only the chemical liquid from the sub flow path 52A is caused to merge and mix with the pure water. As a valve device having the above-described configuration and functions, for example, a manifold valve disclosed in Patent Document 1 is known.

[0004] Japanese Patent Laid-Open No. 2017-141896

[0005] However, the above-mentioned conventional technology had the following problems. The connection portion (opening 53A-53C) where the sub-channels 52A-52C connect to the main channel 55 is a portion that is recessed radially outward with respect to the inner circumferential surface of the main channel 55. As a result, there is a risk that the chemical solution may accumulate in the opening 53A-53C. If the chemical solution accumulates, there is a risk that different types of chemical solutions will mix together, or that the components of the chemical solution will deteriorate and turn into particles. Mixing of chemical solutions and generation of particles can cause defects in semiconductor manufacturing, so it is desirable to prevent the accumulation of chemical solution in the connection portion (opening 53A-53C). The manifold valve disclosed in Patent Document 1 attempts to prevent the accumulation of chemical solution by generating Karman vortices etc. with a small columnar part provided on the valve body, but it is difficult to completely prevent accumulation.

[0006] The present invention aims to solve the above-mentioned problems and to provide a valve device and a method for purging the valve device that can prevent the accumulation of auxiliary fluid at the connection between the main flow path and the auxiliary flow path.

[0007] To solve the above problems, the valve device of the present invention has the following configuration.

[0008] (1) A valve device comprising a main flow path and a sub-flow path connected to the main flow path, wherein the sub-flow path comprises at least two first sub-flow paths sequentially connected to the main flow path from upstream to downstream, and at least two second sub-flow paths on the opposite side of the main flow path from the first sub-flow paths, and sequentially connected to the main flow path from upstream to downstream.

[0009] (2) In the valve device described in (1), it is preferable that the second connection part, in which the second sub-flow passage connects to the main flow passage, is offset upstream of the main flow passage with respect to the first connection part, in which the first sub-flow passage connects to the main flow passage, and that the first sub-flow passage and the second sub-flow passage are connected to the main flow passage in a staggered manner.

[0010] (3) In the valve device described in (1), it is preferable that each of the first connection parts to which the first sub-flow path is connected to the main flow path and each of the second connection parts to which the second sub-flow path is connected to the main flow path are provided opposite to each other.

[0011] (4) In the valve device described in (2) or (3), it is preferable that the first sub-flow channel is a sub-fluid supply channel that supplies a sub-fluid to the main flow channel for mixing with the main flow channel, and the second sub-flow channel is a purge channel that introduces a purge fluid to the main flow channel for flushing out the sub-fluid.

[0012] (5) In the valve device described in (2) or (3), it is preferable that the main flow path extends linearly from upstream to downstream, at least to the extent that the first sub-flow path and the second sub-flow path are connected.

[0013] Furthermore, in order to solve the above problems, the valve device purging method of the present invention has the following configuration.

[0014] (6) A purging method for a valve device for flushing out the auxiliary fluid using the valve device described in (2), characterized in that, after supplying the auxiliary fluid to be mixed with the main body flowing through the main flow path from a selectable connection part of either the first connection part or the second connection part to the main flow path, a purging fluid for flushing out the auxiliary fluid is introduced into the main flow path from the upstream connection part, which is diagonally opposite and upstream of the selectable connection part, among the first connection part and the second connection part.

[0015] In the purging method of the valve device described in (7)(6), it is preferable to introduce the purge fluid from the connection downstream of the upstream connection from which the purge fluid was introduced, among the first connection and the second connection.

[0016] (8) A purging method for a valve device for flushing out the auxiliary fluid using the valve device described in (3), characterized in that, after supplying the auxiliary fluid to be mixed with the main body flowing through the main flow path from a selectable connection part of either the first connection part or the second connection part to the main flow path, a purging fluid for flushing out the auxiliary fluid is introduced into the main flow path from the opposing connection part of the first connection part or the second connection part that is opposite to the selectable connection part.

[0017] In the purging method of the valve device described in (9)(8), it is preferable to introduce the purge fluid from the connection portion downstream of the opposing connection portion from which the purge fluid was introduced, among the first connection portion and the second connection portion.

[0018] In the purging method of the valve device described in (10), (7), or (9), it is preferable to introduce the purging fluid sequentially from the upstream side of the main flow path.

[0019] In the purging method of the valve device described in (11), (6), or (8), it is preferable that the purging fluid is the same fluid as the main fluid.

[0020] According to the valve device or purging method for a valve device of the present invention, since the second sub-channel (purging channel) is provided on the opposite side of the main channel from the first sub-channel (sub-fluid supply channel), for example, if a sub-fluid is supplied from the first sub-channel (sub-fluid supply channel) to the main channel, and then a purge fluid is introduced from the second sub-channel (purging channel) to the main channel, the sub-fluid can be washed away.

[0021] For example, if the second connection point where the second sub-channel (purge channel) connects to the main channel is offset upstream of the main channel relative to the first connection point where the first sub-channel (sub-fluid supply channel) connects to the main channel, the purge fluid introduced from the second sub-channel (purge channel) into the main channel can flow into the first connection point along with the fluid flow in the main channel, and wash away any chemicals remaining in the first connection point.

[0022] For example, if the second connection point where the second sub-channel (purge channel) connects to the main channel is provided opposite the first connection point where the first sub-channel (sub-fluid supply channel) connects to the main channel, then introducing purge fluid from the second sub-channel (purge channel) allows the purge fluid to be directly injected into the first connection point. This makes it possible to wash away any chemical solution remaining in the first connection point. Thus, it is possible to prevent the accumulation of sub-fluid at the connection point between the main channel and the sub-channel.

[0023] This figure shows a schematic configuration of a fluid mixing system utilizing a manifold valve according to the first embodiment. This is a perspective view of the manifold valve according to the first embodiment. This is a partial cross-sectional view of the manifold valve according to the first embodiment. This is a schematic diagram showing the flow of the purge fluid. This figure shows a schematic configuration of a fluid mixing system utilizing a manifold valve according to the second embodiment. This is a perspective view of the manifold valve according to the second embodiment. This is a partial cross-sectional view of the manifold valve according to the second embodiment. This is a cross-sectional view taken along line A-A in Figure 7. This is a simplified representation of a valve device according to the prior art.

[0024] (First Embodiment) A first embodiment of the valve device and valve device purging method according to the present invention will be described. A manifold valve 2A, which is an example of a valve device, is used as part of a fluid mixing system 1A in a semiconductor manufacturing process. The fluid mixing system 1A is a system for selectively mixing one of several types of chemical solutions (an example of a secondary fluid) with pure water (an example of a main fluid). The following will be described in more detail with reference to Figures 1-3. Figure 1 is a diagram showing the schematic configuration of the fluid mixing system 1A using the manifold valve 2A according to the first embodiment. Figure 2 is a perspective view of the manifold valve 2A according to the first embodiment. Figure 3 is a partial cross-sectional view of the manifold valve 2A according to the first embodiment. Figure 4 is a schematic diagram showing the flow of the purging fluid. Note that the above drawings are simplified for illustrative purposes and do not accurately represent the shape, size, etc.

[0025] (Outline configuration of the fluid mixing system) The fluid mixing system 1A mainly consists of a main flow path 10, a secondary fluid supply path 11A-11D which is an example of a first secondary flow path, a purge flow path 12A-12D which is an example of a second secondary flow path, an upstream on-off valve 4, a downstream on-off valve 5, secondary flow path on-off valves 6A-6D, and purge flow path on-off valves 7A-7D.

[0026] An upstream valve 4 is provided on the upstream side (right side in Figure 1) of the main flow path 10, and a pure water supply source 21 is connected further upstream. A downstream valve 5 is provided on the downstream side (left side in Figure 1) of the main flow path 10, and a processing device 22 for etching wafers, for example, is connected further downstream.

[0027] Between the upstream on-off valve 4 and the downstream on-off valve 5 of the main flow path 10, auxiliary fluid supply passages 11A-11D are connected sequentially to the main flow path 10 from upstream to downstream. On the auxiliary fluid supply passages 11A-11D, auxiliary flow path on-off valves 6A-6D are provided, and on their upstream side (lower side in Figure 1), chemical supply sources 23A-23D are connected, respectively. Different types of chemicals are flowed through the auxiliary fluid supply passages 11A-11D. In other words, three types of chemicals are used in the fluid mixing system 1A. In the following description, the fluid supplied from supply source 23A will be referred to as chemical solution A, the fluid supplied from supply source 23B as chemical solution B, the fluid supplied from supply source 23C as chemical solution C, and the fluid supplied from supply source 23D as chemical solution D.

[0028] On the opposite side of the main flow path 10 from the auxiliary fluid supply paths 11A-11C, the purge paths 12A-12C are connected. Since the purge paths 12A-12C are offset upstream of the auxiliary fluid supply paths 11A-11C, the auxiliary fluid supply paths 11A-11C and the purge paths 12A-12C are connected to the main flow path 10 in a staggered manner.

[0029] Purge channel on / off valves 7A-7C are provided on the purge channels 12A-12C, respectively, and a supply source 24 for pure water (an example of a purge fluid) is connected to the upstream side (upper side in Figure 1). It is not necessary to know whether the supply source 24 is the same as the pure water supply source 21 connected to the main channel 10, but the fluid flowing through the purge channels 12A-12D is the same as the main fluid flowing through the main channel 10 (i.e., pure water).

[0030] The fluid mixing system 1A, configured as described above, operates as follows: When the upstream on-off valve 4 and the downstream on-off valve 5 are opened, pure water (main fluid) flows through the main channel 10. Then, depending on the stage of the process in the processing apparatus 22, the required chemical solution is selected from among chemical solutions A to D, and the sub-channel on-off valves 6A to 6C of the corresponding sub-fluid supply channels 11A to 11D are opened, so that the required chemical solution is introduced into the main channel 10 and mixed with the pure water (main fluid). In other words, for example, when the required chemical solution is chemical solution A, the sub-channel on-off valve 6A on the sub-fluid supply channel 11A is opened, and the other sub-channel on-off valves 6B to 6D are closed, so that only chemical solution A is mixed with the pure water (main fluid).

[0031] The solution, which is a mixture of pure water (main fluid) and one of the chemical solutions A-D, flows further downstream through the main channel 10 and is supplied to the processing device 22, where it is used for wafer cleaning, etching, and other processes.

[0032] When switching the chemical solution to be mixed with pure water (main fluid), the chemical solution is flushed out each time by pure water (purging fluid) supplied from the purge channels 12A-12D. Details of the method for performing this flushing (purging method) will be described later.

[0033] (Regarding the configuration of the manifold valve) The manifold valve 2A mainly consists of the manifold 3A, the upstream on-off valve 4, the downstream on-off valve 5, the sub-flow on-off valves 6A-6D, and the purge flow on-off valves 7A-7D.

[0034] The manifold 3A is formed in a roughly rectangular parallelepiped shape, and the main flow path 10 extends linearly inside along the longitudinal direction of the manifold 3A (the left-right direction in Figures 2 and 3).

[0035] On the upstream end face (right side in Figure 3) of the main flow path 10 of the manifold 3A, a valve chamber 31 is drilled toward the downstream side (right side in Figure 3) where the valve body 42 of the upstream on-off valve 4 is installed. The valve chamber 31 and the main flow path 10 are connected by a valve hole 101 provided in the center of the bottom surface 311 of the valve chamber 31. An annular valve seat 312 is provided on the bottom surface 311 so as to surround the valve hole 101, for which the valve body 42 comes into contact with and separates from. Further outward from the outer circumference of the valve seat 312, an internal flow path 32 opens for inputting pure water (main fluid) into the valve chamber 31.

[0036] The internal passage 32 is connected to the supply source 21 (see Figure 1) of pure water (main fluid) via a joint 13 (see Figures 2 and 4) erected on the manifold 3A. Therefore, the pure water (main fluid) supplied from the supply source 21 flows into the valve chamber 31 through the internal passage 32. At this time, since the internal passage 32 opens to the bottom surface 311 of the valve chamber 31, the pure water (main fluid) that flows into the valve chamber 31 flows away from the valve seat 312 and spreads within the valve chamber 31. This prevents the pure water (main fluid) from accumulating in the valve chamber 31. When the valve body 42 is separated from the valve seat 312, the pure water (main fluid) that has flowed into the valve chamber 31 flows into the main passage 10 from the valve hole 101.

[0037] On the downstream end face (left side in Figure 3) of the main flow path 10 of the manifold 3A, a valve chamber 33 is drilled toward the upstream side (right side in Figure 3) where the valve body 52 of the downstream on-off valve 5 is installed. The configuration of the valve chamber 33 is the same as that of the valve chamber 31. That is, the valve chamber 33 is in communication with the main flow path 10 through a valve hole 102. Furthermore, a valve seat 332 is provided on the bottom surface 331 so as to surround the valve hole 102 and allow the valve body 52 to contact and separate, and an internal flow path 34 is open.

[0038] The internal flow path 34 is connected to the processing device 22 (see Figure 1) via a joint 14 (see Figure 2) erected on the manifold 3A. Therefore, the solution, which will be described later, flows from the main flow path 10 through the valve hole 102 into the valve chamber 33, and is then output from the internal flow path 34 to the outside of the manifold valve 2A and supplied to the processing device 22.

[0039] On one of the two end faces of the manifold 3A in a direction perpendicular to the extending direction of the main flow path 10 (left-right direction in Figure 3) (the lower end face in Figure 3), valve chambers 35A-35D for loading the valve bodies 62A-62D of the sub-flow path opening / closing valves 6A-6D are drilled at equal intervals along the extending direction of the main flow path 10.

[0040] The valve chambers 35A-35D are each connected to the main flow path 10 by valve holes 103A-103D (an example of a first connection part) provided in the center of the bottom surface 351A-351D of the valve chambers 35A-35D. The bottom surface 351A-351D is provided with annular valve seats 352A-352D for the valve bodies 62A-62D to come into contact with and separate from each other, surrounding the valve holes 103A-103D. An internal flow path 36A-36D for inputting the chemical solution into the valve chambers 35A-35D is opened in the inner circumferential wall of the valve chambers 35A-35D.

[0041] The internal passages 36A-36D are each connected to the chemical supply source 23A-23D (see Figure 1) via fittings 15A-15D (see Figure 2) erected on the manifold 3A. Therefore, the chemical supplied from the supply source 23A-23D flows into the valve chambers 35A-35D through the internal passages 36A-36D. When the valve bodies 62A-62D are separated from the valve seats 352A-352D, the chemical flows into the main passage 10 through the valve holes 103A-103D. The flow of the chemical into the main passage 10 creates a solution in which the chemical is combined and mixed with the pure water (main fluid) in the main passage 10.

[0042] On the end face of the manifold 3A opposite to the side where the valve chambers 35A-35D are drilled (the upper end face in Figure 3), valve chambers 37A-37D for loading the valve bodies 72A-72D of the purge flow path on / off valves 7A-7D are drilled at equal intervals along the extending direction of the main flow path 10.

[0043] The valve chambers 37A to 37D are each communicated with the main flow path 10 via valve holes 104A to 104D (an example of the second connection portion) provided at the center of the bottom surfaces 371A to 371D of the valve chambers 37A to 37D. The valve holes 104A to 104D open on the opposite side of the valve holes 103A to 103D across the main flow path 10, and the valve holes 104A to 104D are offset upstream relative to the valve holes 103A to 103C. Annular valve seats 372A to 372D, against which valve bodies 72A to 72D abut and separate, are provided on the bottom surfaces 371A to 371D so as to surround the valve holes 104A to 104D. On the inner peripheral wall of the valve chambers 37A to 37D, internal flow paths 38A to 38D for introducing pure water (purge fluid) into the valve chambers 37A to 37D are open.

[0044] The internal flow paths 38A to 38D are each connected to a supply source 24 (see FIG. 1) of pure water (purge fluid) via joints 16A to 16D (see FIG. 2) erected on the manifold 3A. Accordingly, the pure water (purge fluid) supplied from the supply source 24 flows into the valve chambers 37A to 37D through the internal flow paths 38A to 38D. Then, when the valve bodies 72A to 72D are separated from the valve seats 372A to 372D, the pure water (purge fluid) that has flowed into the valve chambers 37A to 37D flows into the main flow path 10 through the valve holes 104A to 104D.

[0045] The upstream on-off valve 4, the downstream on-off valve 5, the sub flow path on-off valves 6A to 6D, and the purge flow path on-off valves 7A to 7D mainly include drive units 41, 51, 61A to 61D, 71A to 71D, and valve bodies 42, 52, 62A to 62D, 72A to 72D driven by the drive units 41, 51, 61A to 61D, 71A to 71D, respectively. All of the drive units 41, 51, 61A to 61D, 71A to 71D have the same configuration, and all of the valve bodies 42, 52, 62A to 62D, 72A to 72D also have the same configuration. In the following description, unless particular distinction is required, the alphabetical suffixes of reference numerals will be omitted where appropriate.

[0046] The drive units 41, 51, 61, 71 are air-operated or electric drive sources for opening and closing the respective valves 4, 5, 6, 7. A drive shaft (not shown) is built into each of the drive units 41, 51, 61, 71. Since the drive shaft is connected to valve bodies 42, 52, 62, 72, advancement and retraction of the drive shaft causes the valve bodies 42, 52, 62, 72 to contact and separate from valve seats 312, 332, 352, 372 (that is, opening and closing operations of the respective valves 4, 5, 6, 7 are performed). The opening and closing operations of the respective valves 4, 5, 6, 7 are controlled by a host control device (not shown).

[0047] The upstream-side opening / closing valve 4 controls the inflow of pure water (main fluid) into the main flow path 10 through its opening and closing operation. The sub-flow path opening / closing valve 6 controls the inflow of chemical liquid into the main flow path 10 through its opening and closing operation. More specifically, the sub-flow path opening / closing valve 6 remains on standby in a closed state except when introducing a chemical liquid. When introduction of a chemical liquid is required, a host control device selectively operates any one of the sub-flow path opening / closing valves 6A-6D, thereby causing the required chemical liquid to flow into the main flow path 10.

[0048] The purge flow path opening / closing valve 7 controls the inflow of pure water (purge fluid) into the main flow path 10 through its opening and closing operation. More specifically, the purge flow path opening / closing valves 7A-7D remain on standby in a closed state except when washing away chemical liquid. When washing away of chemical liquid is required, a host control device selectively operates any one or more of the purge flow path opening / closing valves 7A-7D, thereby washing away the chemical liquid at a required position.

[0049] The downstream-side opening / closing valve 5 controls the output of solution or pure water (main fluid and / or purge fluid) to the outside of the manifold valve 2A through its opening and closing operation. Each of the valves 4, 5, 6, 7 may switch ON / OFF of the flow of each fluid by a simple opening and closing operation, or may be capable of adjusting the flow rate of each fluid by adjusting the opening degree of the valve bodies 42, 52, 62, 72.

[0050] (Regarding Purge Method) Washing away of chemical liquid performed in the manifold valve 2A having the above configuration will be described.

[0051] The connection point where the auxiliary fluid supply passages 11A-11D connect to the main flow path 10 (i.e., the valve holes 103A-103D) is recessed radially outward relative to the inner circumferential surface of the main flow path 10. As a result, there is a risk of chemical liquid accumulating in the valve holes 103A-103D. Therefore, in the manifold valve 2A, purge fluid is introduced into the main flow path 10 from the purge passages 12A-12D, which are opposite the auxiliary fluid supply passages 11A-11D into which the chemical liquid has been merged, and pure water (purge fluid) is directly injected into the valve holes 103A-103D to wash away any chemical liquid accumulating in the valve holes 103A-103D.

[0052] More specifically, it is as follows: When it is necessary to mix chemical solution A from chemical solutions A-D with pure water (main fluid), the higher-level control device opens the sub-flow channel on / off valve 6A, thereby introducing chemical solution A into the main flow channel 10 from the sub-fluid supply channel 11A (valve hole 103A (selective connection part)). At this time, most of the chemical solution A is carried downstream by the flow of pure water (main fluid) in the main flow channel 10 and mixed with the pure water (main fluid), but there is a risk that a small amount of chemical solution A may remain in the valve hole 103A. If this occurs, there is a risk that when chemical solution B, chemical solution C, or chemical solution D is to be introduced into the main flow channel 10 next, it may mix with chemical solution A, or the components of chemical solution A may deteriorate, become particles, and flow into the processing device 22.

[0053] Therefore, after introducing the chemical solution A from the auxiliary fluid supply passage 11A into the main flow path 10, the higher-level control device opens the purge flow path on / off valve 7A, thereby introducing pure water (purge fluid) into the main flow path 10 from the purge flow path 12A (valve opening 104A (upstream connection part)) which is diagonally opposite and upstream of the auxiliary fluid supply passage 11A (valve opening 103A (selective connection part)).

[0054] Since the purge channel 12 and the auxiliary fluid supply channel 11 are connected to the main channel 10 in a staggered manner, that is, the valve hole 104A of the purge channel 12A is offset upstream of the valve hole 103A of the auxiliary fluid supply channel 11A, if pure water (purge fluid) is introduced from the diagonally opposite purge channel 12A (valve hole 104A), as shown in Figure 4, the pure water (purge fluid) carried by the fluid flow in the main channel 10 flows into the valve hole 103A. The pure water (purge fluid) that flows into the valve hole 103A then washes away the contents of the valve hole 103A and flows further downstream in the main channel 10. Therefore, it is possible to wash away any chemical solution remaining in the valve hole 103A.

[0055] Similarly, when the sub-channel valve 6B is opened and chemical solution B is introduced into the main channel 10, the purge channel valve 7B is opened to flush out the chemical solution remaining in the valve opening 103B. Also, when the sub-channel valve 6C is opened and chemical solution C is introduced into the main channel 10, the purge channel valve 7C is opened to flush out the chemical solution remaining in the valve opening 103C. Furthermore, when the sub-channel valve 6D is opened and chemical solution D is introduced into the main channel 10, the purge channel valve 7D is opened to flush out the chemical solution remaining in the valve opening 103D. By performing the flushing in the above manner, the accumulation of chemical solution in the valve openings 103A-103D can be prevented.

[0056] Furthermore, if the upstream valve port 103A-103D is flushed, it is possible that the flushed chemical solution may enter the downstream valve port. More specifically, for example, if the chemical solution is introduced into the main flow path 10 from the auxiliary fluid supply passage 11A, and then the chemical solution in valve port 103A is flushed out by pure water (purge fluid) introduced from the purge passage 12A, the flushed chemical solution may enter and remain in the further downstream valve ports 103B, 103C, 103D, 104B, 104C, and 104D. However, because the main flow path 10 extends in a straight line, it is difficult for the flushed chemical solution to enter the downstream valve ports. The main flow path 10 is formed in a straight line from one end to the other of the longitudinal ends of the manifold 3A, but is not limited to this, and only needs to extend in a straight line to the extent that the auxiliary fluid supply passages 11A-11D and the purge passages 12A-12D are connected. If the main flow path 10 extends in a straight line to the extent that the auxiliary fluid supply passages 11A-11D and the purge passages 12A-12D are connected, it is possible to prevent the chemical solution washed away on the upstream side from entering the valve hole on the downstream side.

[0057] Furthermore, in order to reliably prevent the chemical solution flushed upstream from entering the valve opening downstream, it is preferable that pure water (purge fluid) be introduced not only from the purge passage 12A-12D (valve openings 104A-104D (upstream connection)) which is diagonally opposite and upstream of the auxiliary fluid supply passage 11A-11D (valve openings 103A-103D) where the chemical solution is introduced, but also from the further downstream purge passage 12A-12D (valve openings 104A-104D). More specifically, for example, when flushing is performed in the purge passage 12A (valve opening 103A), it is preferable that not only is flushing performed in the purge passage 12A (valve opening 104A), but pure water (purge fluid) is also introduced into the main passage 10 from the further downstream purge passage 12B-12D (valve openings 104B-104D) to perform flushing. This prevents the chemical solution flushed out at the upstream valve opening from entering and remaining in the downstream valve opening.

[0058] In this case, the timing of the introduction of pure water (purge fluid) from each purge channel 12A-12D may all be simultaneous. Alternatively, pure water (purge fluid) may be introduced from purge channel 12A to wash away the chemical solution, and then pure water (purge fluid) may be introduced simultaneously from purge channels 12B, 12C, and 12D. Alternatively, pure water (purge fluid) may be introduced from purge channel 12A, and then pure water (purge fluid) may be introduced in the order of purge channel 12B, purge channel 12C, and purge channel 12D, that is, from upstream to downstream.

[0059] The same applies when, after the chemical solution is introduced into the main channel 10 from the auxiliary fluid supply channel 11B, the chemical solution in the valve port 103B is flushed out by the introduction of pure water (purge fluid) from the purge channel 12B. Furthermore, by introducing pure water (purge fluid) into the main channel 10 from the downstream purge channels 12C and 12D, it becomes possible to prevent the residue of the flushed chemical solution.

[0060] If, after the chemical solution is introduced into the main flow path 10 from the downstream auxiliary fluid supply passage 11D, the valve opening 103D is flushed out by introducing pure water (purge fluid) from the purge flow path 12D, there is no risk of the flushed chemical solution remaining in the other valve openings 103A, 103B, 103C, 104A, 104B, and 104C. Therefore, the introduction of pure water (purge fluid) through the purge flow paths 12A, 12B, and 12C is not required.

[0061] In the first embodiment, all of the first sub-channels connected sequentially to the main channel 10 from upstream to downstream (all of the channels indicated by reference numerals 11A-11D) are sub-fluid supply channels for supplying a sub-fluid (chemical solution) to the main channel 10, and all of the second sub-channels connected sequentially to the main channel 10 from upstream to downstream (all of the channels indicated by reference numerals 12A-12D) are purge channels for introducing purge fluid into the main channel 10. However, it is possible to adjust as appropriate whether each channel 11A-11D, 12A-12D is used as a sub-fluid supply channel or a purge channel. For example, the channels indicated by reference numeral 11A-11D can be configured as a sub-fluid supply channel, a purge channel, a sub-fluid supply channel, and a purge channel in order from the upstream side, and the same applies to the channels indicated by reference numeral 12A-12D. To prevent the accumulation of sub-fluid, the channel upstream and diagonally opposite to the channel used as a sub-fluid supply channel can be used as a purge channel. For example, if the flow path 12B is used as a secondary fluid supply path, the diagonally opposite and upstream flow path 11A can be used as a purge path to prevent the secondary fluid from accumulating in the valve opening 104B.

[0062] Furthermore, in order to supply the main fluid to the main flow path 10, it is not necessarily required to use the upstream on-off valve 4, and the main fluid may be supplied to the main flow path 10 from either the first sub-flow path or the second sub-flow path (flow paths indicated by reference numerals 11A-11D and 12A-12D). Moreover, in order to output the solution to the processing device 22, it is not necessarily required to use the downstream on-off valve 5, and the solution may be output to the processing device 22 from either the first sub-flow path or the second sub-flow path (flow paths indicated by reference numerals 11A-11D and 12A-12D).

[0063] (Second Embodiment) A second embodiment of the valve device and valve device purging method according to the present invention will be described. A manifold valve 2B, which is an example of a valve device, is used as part of a fluid mixing system 1 in a semiconductor manufacturing process. The fluid mixing system 1 is a system for selectively mixing one of several types of chemical solutions (an example of a secondary fluid) with pure water (an example of a main fluid). The following will be described in more detail with reference to Figures 5-8. Figure 5 is a diagram showing the schematic configuration of a fluid mixing system 1B that utilizes the manifold valve 2B according to the second embodiment. Figure 6 is a perspective view of the manifold valve 2B according to the second embodiment. Figure 7 is a partial cross-sectional view of the manifold valve 2B according to the second embodiment. Figure 8 is a cross-sectional view taken along line A-A in Figure 7. Note that the above drawings are simplified for illustrative purposes and do not accurately represent the shape, size, etc.

[0064] (Outline configuration of the fluid mixing system) The fluid mixing system 1B mainly consists of a main flow path 10, a secondary fluid supply path 11A-11C which is an example of a first secondary flow path, a purge flow path 12A-12C which is an example of a second secondary flow path, an upstream on-off valve 4, a downstream on-off valve 5, secondary flow path on-off valves 6A-6C, and purge flow path on-off valves 7A-7C.

[0065] An upstream valve 4 is provided on the upstream side (right side in Figure 5) of the main flow path 10, and a pure water supply source 21 is connected further upstream. A downstream valve 5 is provided on the downstream side (left side in Figure 5) of the main flow path 10, and a processing device 22 for performing wafer etching is connected further downstream.

[0066] Between the upstream on-off valve 4 and the downstream on-off valve 5 of the main flow path 10, auxiliary fluid supply passages 11A-11C are connected sequentially to the main flow path 10 from upstream to downstream. On the auxiliary fluid supply passages 11A-11C, auxiliary flow path on-off valves 6A-6C are provided, and on their upstream side (lower side in Figure 5), chemical supply sources 23A-23C are connected, respectively. Different types of chemicals are flowed through the auxiliary fluid supply passages 11A-11C. In other words, three types of chemicals are used in the fluid mixing system 1B. In the following description, the fluid supplied from supply source 23A will be referred to as chemical solution A, the fluid supplied from supply source 23B as chemical solution B, and the fluid supplied from supply source 23C as chemical solution C.

[0067] The main flow path 10 is connected to purge flow paths 12A-12C opposite to the auxiliary fluid supply paths 11A-11C. Purge flow path on / off valves 7A-7C are provided on the purge flow paths 12A-12C, and a supply source 24 for pure water (an example of purge fluid) is connected to the upstream side (upper side in Figure 5). It is not necessary to know whether the supply source 24 is the same as the pure water supply source 21 connected to the main flow path 10, but the fluid flowing through the purge flow paths 12A-12C is the same as the main fluid flowing through the main flow path 10 (i.e., pure water).

[0068] The fluid mixing system 1B, configured as described above, operates as follows: When the upstream on-off valve 4 and the downstream on-off valve 5 are opened, pure water (main fluid) flows through the main channel 10. Then, depending on the stage of the process in the processing apparatus 22, the required chemical solution is selected from among chemical solutions A to C, and the sub-channel on-off valves 6A to 6C of the corresponding sub-fluid supply passages 11A to 11C are opened, so that the required chemical solution is introduced into the main channel 10 and mixed with the pure water (main fluid). In other words, for example, when the required chemical solution is chemical solution A, the sub-channel on-off valve 6A on the sub-fluid supply passage 11A is opened, and the other sub-channel on-off valves 6B to 6C are closed, so that only chemical solution A is mixed with the pure water (main fluid).

[0069] The solution, which is a mixture of pure water (main fluid) and one of the chemical solutions A-C, flows further downstream through the main channel 10 and is supplied to the processing device 22, where it is used for wafer cleaning, etching, and other processes.

[0070] When switching the chemical solution to be mixed with pure water (main fluid), the chemical solution is flushed out each time by pure water (purging fluid) supplied from the purge channels 12A-12C. Details of the method for performing this flushing (purging method) will be described later.

[0071] (Regarding the configuration of the manifold valve) The manifold valve 2B mainly consists of the manifold 3B, the upstream on-off valve 4, the downstream on-off valve 5, the sub-flow on-off valves 6A-6C, and the purge flow on-off valves 7A-7C.

[0072] The manifold 3B is formed in a roughly rectangular parallelepiped shape, and the main flow path 10 extends linearly inside along the longitudinal direction of the manifold 3 (left-right direction in Figure 7).

[0073] On the upstream end face (right side in Figure 7) of the main flow path 10 of the manifold 3B, a valve chamber 31 is drilled toward the downstream side (right side in Figure 7) where the valve body 42 of the upstream on-off valve 4 is installed. The valve chamber 31 and the main flow path 10 are connected by a valve hole 101 provided in the center of the bottom surface 311 of the valve chamber 31. An annular valve seat 312 is provided on the bottom surface 311, surrounding the valve hole 101, for the valve body 42 to contact and separate. Further outward from the outer circumference of the valve seat 312, an internal flow path 32 opens for inputting pure water (main fluid) into the valve chamber 31 (see Figure 8).

[0074] The internal passage 32 is connected to the supply source 21 (see Figure 5) of pure water (main fluid) via a joint 13 (see Figures 6 and 8) erected on the manifold 3B. Therefore, the pure water (main fluid) supplied from the supply source 21 flows into the valve chamber 31 through the internal passage 32. At this time, since the internal passage 32 opens to the bottom surface 311 of the valve chamber 31, the pure water (main fluid) that flows into the valve chamber 31 flows away from the valve seat 312 and spreads within the valve chamber 31. This prevents the pure water (main fluid) from accumulating in the valve chamber 31. When the valve body 42 is separated from the valve seat 312, the pure water (main fluid) that has flowed into the valve chamber 31 flows into the main passage 10 from the valve hole 101.

[0075] On the downstream end face of the manifold 3B (left side in Figure 7) of the main flow path 10, a valve chamber 33 is drilled toward the upstream side (right side in Figure 7) where the valve body 52 of the downstream on-off valve 5 is installed. The configuration of the valve chamber 33 is the same as that of the valve chamber 31. That is, the valve chamber 33 is in communication with the main flow path 10 through a valve hole 102. Furthermore, a valve seat 332 is provided on the bottom surface 331 so as to surround the valve hole 102 and allow the valve body 52 to contact and separate, and an internal flow path 34 is open.

[0076] The internal flow path 34 is connected to the processing device 22 (see Figure 5) via a joint 14 (see Figure 6) erected on the manifold 3B. Therefore, the solution, which will be described later, flows from the main flow path 10 through the valve hole 102 into the valve chamber 33, and is then output from the internal flow path 34 to the outside of the manifold valve 2B and supplied to the processing device 22.

[0077] On one of the two end faces of the manifold 3B in a direction perpendicular to the extending direction of the main flow path 10 (the left-right direction in Figure 7) (the lower end face in Figure 7), valve chambers 35A-35C for loading the valve bodies 62A-62C of the sub-flow path opening / closing valves 6A-6C are drilled at equal intervals along the extending direction of the main flow path 10.

[0078] The valve chambers 35A-35C are each connected to the main flow path 10 by valve holes 103A-103C (an example of a first connection part) provided in the center of the bottom surface 351A-351C of the valve chambers 35A-35C. The bottom surface 351A-351C is provided with annular valve seats 352A-352C for the valve bodies 62A-62C to come into contact with and separate from each other, surrounding the valve holes 103A-103C. An internal flow path 36A-36C for inputting the chemical solution into the valve chambers 35A-35C is opened in the inner circumferential wall of the valve chambers 35A-35C.

[0079] The internal passages 36A-36C are each connected to the chemical supply source 23A-23C (see Figure 5) via fittings 15A-15C (see Figure 6) erected on the manifold 3B. Therefore, the chemical supplied from the supply source 23A-23C flows into the valve chambers 35A-35C through the internal passages 36A-36C. When the valve bodies 62A-62C are separated from the valve seats 352A-352C, the chemical that has flowed into the valve chambers 35A-35C flows into the main passage 10 through the valve holes 103A-103C. By flowing the chemical into the main passage 10, a solution can be generated in which the chemical is combined and mixed with the pure water (main fluid) in the main passage 10.

[0080] On the end face of the manifold 3B opposite to the side where the valve chambers 35A-35C are drilled (the upper end face in Figure 7), valve chambers 37A-37C for loading the valve bodies 72A-72C of the purge flow path on / off valves 7A-7C are drilled at equal intervals along the extending direction of the main flow path 10.

[0081] The valve chambers 37A-37C are each connected to the main flow path 10 by valve holes 104A-104C (an example of a second connection part) provided in the center of the bottom surface 371A-371C of the valve chambers 37A-37C. The valve holes 104A-104C are provided opposite to the valve holes 103A-103C. In this embodiment, the valve holes 103A-103C and the valve holes 104A-104C are located coaxially. The bottom surface 371A-371C is provided with annular valve seats 372A-372C for the valve bodies 72A-72C to come into contact with and separate from the valve holes 104A-104C. Internal flow paths 38A-38C for inputting pure water (purge fluid) into the valve chambers 37A-37C are opened in the inner circumferential wall of the valve chambers 37A-37C.

[0082] The internal passages 38A-38C are each connected to a pure water (purge fluid) supply source 24 (see Figure 5) via joints 16A-16C (see Figure 6) erected on the manifold 3B. Therefore, the pure water (purge fluid) supplied from the supply source 24 flows into the valve chambers 37A-37C through the internal passages 38A-38C. The pure water (purge fluid) that has flowed into the valve chambers 37A-37C then flows into the main passage 10 through the valve holes 104A-104C when the valve bodies 72A-72B are separated from the valve seats 372A-372B.

[0083] The upstream on-off valve 4, the downstream on-off valve 5, the sub-flow on-off valves 6A-6C, and the purge flow on-off valves 7A-7C each consist mainly of drive units 41, 51, 61A-61C, and 71A-71C, and valve bodies 42, 52, 62A-62C, and 72A-72C driven by the drive units 41, 51, 61A-61C, and 71A-71C. Each drive unit 41, 51, 61A-61C, and 71A-71C has the same configuration, and each valve body 42, 52, 62A-62C, and 72A-72C also has the same configuration. Furthermore, in the following description, the letters of the symbols will be omitted where necessary, unless otherwise specified.

[0084] The drive units 41, 51, 61, and 71 are air-operated or electric drive sources for opening and closing valves 4, 5, 6, and 7. Each drive unit 41, 51, 61, and 71 has a built-in drive shaft (not shown). Since the drive shaft is connected to the valve bodies 42, 52, 62, and 72, the movement of the drive shaft causes the valve bodies 42, 52, 62, and 72 to contact and separate from the valve seats 312, 332, 352, and 372 (i.e., the opening and closing operations of valves 4, 5, 6, and 7 are performed). The opening and closing operations of valves 4, 5, 6, and 7 are controlled by a higher-level control device (not shown).

[0085] The upstream on-off valve 4 controls the inflow of pure water (main fluid) into the main channel 10 through its opening and closing operation. The sub-channel on-off valve 6 controls the inflow of chemical solution into the main channel 10 through its opening and closing operation. More specifically, the sub-channel on-off valve 6 remains closed except when introducing chemical solution, and when the introduction of chemical solution is necessary, the higher-level control device selectively operates one of the sub-channel on-off valves 6A-6C to allow the required chemical solution to flow into the main channel 10.

[0086] The purge channel on / off valve 7 controls the inflow of pure water (purge fluid) into the main channel 10 by opening and closing it. More specifically, the purge channel on / off valves 7A-7C remain closed except when flushing out the chemical solution. When flushing out the chemical solution is necessary, a higher-level control device selectively operates one or more of the purge channel on / off valves 7A-7C to flush out the chemical solution at the required location.

[0087] The downstream on-off valve 5 controls the output of the solution or pure water (main fluid and / or purge fluid) to the outside of the manifold valve 2B by opening and closing it. Each valve 4, 5, 6, and 7 may switch the flow of each fluid ON and OFF with a simple opening and closing operation, or it may be possible to adjust the flow rate of each fluid by adjusting the opening degree of the valve bodies 42, 52, 62, and 72.

[0088] (Regarding the purging method) The flushing of the chemical solution in the manifold valve 2B having the above configuration will now be explained.

[0089] The connection point where the auxiliary fluid supply passages 11A-11C connect to the main flow path 10 (i.e., the valve holes 103A-103C) is recessed radially outward relative to the inner circumferential surface of the main flow path 10. As a result, there is a risk of chemical liquid accumulating in the valve holes 103A-103C. Therefore, in the manifold valve 2B, purge fluid is introduced into the main flow path 10 from the purge passages 12A-12C, which are opposite the auxiliary flow path into which the chemical liquid has been merged, and pure water (purge fluid) is directly injected into the valve holes 103A-103C to wash away any chemical liquid accumulating in the valve holes 103A-103C.

[0090] More specifically, it is as follows: When it is necessary to mix chemical solution A of chemical solutions A-C with pure water (main fluid), the higher-level control device opens the sub-flow channel valve 6A to introduce chemical solution A from the sub-fluid supply channel 11A into the main flow channel 10. At this time, most of the chemical solution A is carried downstream by the flow of pure water (main fluid) in the main flow channel 10 and mixed with the pure water (main fluid), but there is a risk that a small amount of chemical solution A will remain in the valve hole 103A. If this occurs, there is a risk that when chemical solution B or chemical solution C is to be introduced into the main flow channel 10 next, it may mix with chemical solution A, or the components of chemical solution A may deteriorate, become particles, and flow into the processing device 22.

[0091] Therefore, after introducing the chemical solution A from the auxiliary fluid supply passage 11A into the main passage 10, the higher-level control device opens the purge passage on / off valve 7A, thereby introducing pure water (purge fluid) into the main passage 10 from the purge passage 12A, which is connected to the main passage 10 opposite the auxiliary fluid supply passage 11A. Since the valve hole 104A of the purge passage 12A is located opposite the valve hole 103A, introducing pure water (purge fluid) from the purge passage 12A allows the pure water (purge fluid) to be directly injected into the valve hole 103A. This makes it possible to flush out the chemical solution that has accumulated in the valve hole 103A. Similarly, when the auxiliary passage on / off valve 6B is opened and the chemical solution B is introduced into the main passage 10, the purge passage on / off valve 7B is opened to flush out the chemical solution that has accumulated in the valve hole 103B. Furthermore, when the sub-channel valve 6C is opened and the chemical solution C is introduced into the main channel 10, the purge channel valve 7C is opened to flush out the chemical solution remaining in the valve opening 103C. By performing the flushing described above, the accumulation of chemical solution in the valve openings 103A-103C can be prevented.

[0092] The rinsing of the chemical solution may be performed while pure water (main fluid) is flowing through the main channel 10 (i.e., with the upstream on-off valve 4 open), or it may be performed when the flow of pure water (main fluid) is blocked (i.e., with the upstream on-off valve 4 closed). Alternatively, the rinsing may be performed when the opening of the upstream on-off valve 4 is reduced so that the flow of pure water (main fluid) is weaker than when the chemical solution is mixed with the pure water (main fluid).

[0093] Furthermore, if the upstream valve port of valve ports 103A-103C is flushed, it is possible that the flushed chemical solution may enter the downstream valve port. More specifically, for example, if the chemical solution is introduced into the main flow path 10 from the auxiliary fluid supply passage 11A, and then the chemical solution in valve port 103A is flushed out by pure water (purge fluid) introduced from the purge flow path 12A, there is a risk that the flushed chemical solution may enter and remain in the further downstream valve ports 103B, 103C, 104B, and 104C. However, since the main flow path 10 extends in a straight line, it is difficult for the flushed chemical solution to enter the downstream valve ports. Note that the main flow path 10 is formed in a straight line from one end to the other of the longitudinal ends of the manifold 3B, but is not limited to this, and only needs to extend in a straight line in the range where the auxiliary fluid supply passages 11A-11C and the purge flow paths 12A-12C are connected. If the main flow path 10 extends linearly to the extent that it is connected to at least the auxiliary fluid supply passages 11A-11C and the purge passages 12A-12C, it is possible to prevent the chemical solution washed away on the upstream side from entering the valve hole on the downstream side.

[0094] Furthermore, in order to reliably prevent the chemical solution flushed out on the upstream side from entering the valve port on the downstream side, it is preferable to introduce pure water (purge fluid) not only from the purge channels 12A-12C opposite the auxiliary fluid supply channels 11A-11C through which the chemical solution is introduced, but also from the purge channels further downstream. More specifically, for example, when flushing is performed in the purge channel 12A, it is preferable to not only flush the channel 12A, but also to introduce pure water (purge fluid) into the main channel 10 from the further downstream purge channels 12B and 12C to perform the flushing. This makes it possible to prevent the chemical solution flushed out in the upstream valve port from entering and remaining in the downstream valve port.

[0095] In this case, the timing of the introduction of pure water (purging fluid) from each purge channel 12A-12C may be simultaneous. Alternatively, pure water (purging fluid) may be introduced from purge channel 12A to flush out the chemical solution, and then pure water (purging fluid) may be introduced simultaneously from purge channel 12B and purge channel 12C. Alternatively, pure water (purging fluid) may be introduced from purge channel 12A to flush out the chemical solution, and then pure water (purging fluid) may be introduced from purge channel 12B first, followed by pure water (purging fluid) from purge channel 12C, and so on, with the pure water (purging fluid) being introduced sequentially from the upstream side.

[0096] The same applies when, after the chemical solution is introduced into the main channel 10 from the auxiliary fluid supply channel 11B, the chemical solution in the valve port 103B is flushed out by the introduction of pure water (purge fluid) from the purge channel 12B. Furthermore, by introducing pure water (purge fluid) into the main channel 10 from the downstream purge channel 12C, it becomes possible to prevent the residue of the flushed chemical solution from remaining.

[0097] If, after the chemical solution is introduced into the main flow path 10 from the downstream auxiliary fluid supply passage 11C, the valve port 103C is flushed out by introducing pure water (purge fluid) from the purge flow path 12C, there is no risk of the flushed chemical solution remaining in the other valve ports 103A, 103B, 104A, and 104B. Therefore, the introduction of pure water (purge fluid) through the purge flow paths 12A and 12B is not required.

[0098] In the second embodiment, all of the first sub-channels connected sequentially to the main channel 10 from upstream to downstream (all of the channels indicated by reference numerals 11A-11C) are sub-fluid supply channels for supplying a sub-fluid (chemical solution) to the main channel 10, and all of the second sub-channels connected sequentially to the main channel 10 from upstream to downstream (all of the channels indicated by reference numerals 12A-12C) are purge channels for introducing purge fluid into the main channel 10. However, it is possible to use each channel 11A-11C, 12A-12C as a sub-fluid supply channel or as a purge channel as appropriate. For example, the channels indicated by reference numerals 11A-11C can be configured as a sub-fluid supply channel, a purge channel, and a sub-fluid supply channel in order from the upstream side, and the same applies to the channels indicated by reference numerals 12A-12C. In this case, in order to prevent the accumulation of sub-fluid, the channel opposite to the channel used as a sub-fluid supply channel can be used as a purge channel. If the flow path 12A is used as a secondary fluid supply path, then by using the flow path 11A opposite to the flow path 12A as a purge path, it is possible to prevent the secondary fluid from accumulating in the valve opening 104A.

[0099] Furthermore, in order to supply the main fluid to the main flow path 10, it is not necessarily required to use the upstream on-off valve 4, and the main fluid may be supplied to the main flow path 10 from either the first sub-flow path or the second sub-flow path (flow paths indicated by reference numerals 11A-11C and 12A-12C). Moreover, in order to output the solution to the processing device 22, it is not necessarily required to use the downstream on-off valve 5, and the solution may be output to the processing device 22 from either the first sub-flow path or the second sub-flow path (flow paths indicated by reference numerals 11A-11C and 12A-12C).

[0100] As described above, according to the valve device of this embodiment (for example, manifold valves 2A, 2B), (1) in a valve device (manifold valves 2A, 2B) comprising a main passage 10 and a sub-passage connected to the main passage 10, the sub-passage comprises at least two first sub-passages (sub-fluid supply passages 11A-11D) that are sequentially connected to the main passage 10 from upstream to downstream, and at least two second sub-passages (purge passages 12A-12D) that are connected to the main passage 10 sequentially from upstream to downstream on the opposite side of the main passage 10 from the first sub-passages (sub-fluid supply passages 11A-11D).

[0101] (2) In the valve device (manifold valve 2A) described in (1), the second connection part (valve hole 104A-104D) in which the second sub-flow path (purge flow path 12A-12C) connects to the main flow path 10 is offset upstream of the main flow path 10 with respect to the first connection part (valve hole 103A-103D) in which the first sub-flow path (sub-fluid supply path 11A-11D) connects to the main flow path 10, and it is preferable that the first sub-flow path (sub-fluid supply path 11A-11D) and the second sub-flow path (purge flow path 12A-12C) are connected to the main flow path 10 in a staggered manner.

[0102] (3) In the valve device (manifold valve 2B) described in (1), it is preferable that each of the first connection parts (valve holes 103A-103C) to which the first sub-flow path (sub-fluid supply path 11A-11C) connects to the main flow path 10 and each of the second connection parts (valve holes 104A-104C) to which the second sub-flow path (purge flow path 12A-12C) connects to the main flow path 10 are provided opposite to each other. Hereinafter, "opposing" does not mean that the first connection part and the second connection part are located on the same axis, but rather that when the first connection part and the second connection part are projected in the axial direction, the first connection part and the second connection part overlap. In other words, in the manifold valve 2B described above, valve holes 103A and 104A are located coaxially, valve holes 103B and 104B are located coaxially, and valve holes 103C and 104C are located coaxially. However, it is not necessary for them to be located coaxially. It is sufficient if valve holes 103A and 104A overlap when projected axially, if valve holes 103B and 104B overlap when projected axially, and if valve holes 103C and 104C overlap when projected axially.

[0103] (4) In the valve device (manifold valve 2A, 2B) described in (2) or (3), it is preferable that the first sub-flow channel is a sub-fluid supply channel 11A-11D that supplies a sub-fluid (chemical solution) to the main flow channel 10 for mixing with the main flow channel 10, and the second sub-flow channel is a purge channel 12A-12D that introduces a purge fluid (pure water) to the main flow channel 10 for washing away the sub-fluid (chemical solution).

[0104] (5) In the valve device (manifold valve 2A, 2B) described in (2) or (3), it is preferable that the main flow path 10 extends linearly from upstream to downstream in the range to which at least the first subflow path (sub-fluid supply path 11A-11D) and the second subflow path (purge path 12A-12C) are connected.

[0105] Furthermore, as described above, the purging method of the valve device of this embodiment is a purging method of a valve device for flushing out a secondary fluid (chemical solution) using the valve device (manifold valve 2A) described in (6)(2), characterized in that, after supplying a secondary fluid (chemical solution) to be mixed with the main body flowing through the main flow path 10 from one of the selected connection parts of the first connection part (valve holes 103A-103D) and the second connection part (valve holes 104A-104D) to the main flow path 10, a purging fluid (pure water) for flushing out the secondary fluid (chemical solution) is introduced into the main flow path 10 from the upstream connection part that is diagonally opposite and upstream of the selected connection part of the first connection part (valve holes 103A-103D) and the second connection part (valve holes 104A-104D). The upstream connection portion is, for example, valve hole 104A if the selectable connection portion is valve hole 103A, valve hole 104B if the selectable connection portion is valve hole 103B, valve hole 104C if the selectable connection portion is valve hole 103C, valve hole 104D if the selectable connection portion is valve hole 103D, valve hole 103A if the selectable connection portion is valve hole 104B, valve hole 103B if the selectable connection portion is valve hole 104C, and valve hole 103C if the selectable connection portion is valve hole 104D.

[0106] (7) In the purging method of the valve device described in (6), it is preferable to introduce the purge fluid from the connection part downstream of the upstream connection part from which the purge fluid was introduced, among the first connection part (valve holes 103A-103D) and the second connection part (valve holes 104A-104D). The connection part downstream of the upstream connection part is, for example, if the upstream connection part is valve hole 103A or valve hole 104A, then it is valve holes 103B-103D, 104B-104D; if the upstream connection part is valve hole 103B or valve hole 104B, then it is valve holes 103C-103D, 104C-104D; and if the upstream connection part is valve hole 103C or valve hole 104C, then it is valve holes 103D, 104D.

[0107] (8) A purging method for a valve device (manifold valve 2B) described in (3) for flushing away a secondary fluid (chemical solution), characterized in that, after supplying a secondary fluid (chemical solution) to be mixed with the main body flowing through the main flow path 10 from a selectable connection part among the first connection part (valve holes 103A-103C) and the second connection part (valve holes 104A-104C), a purging fluid (pure water) for flushing away the secondary fluid (chemical solution) is introduced into the main flow path from the opposing connection part of the first connection part (valve holes 103A-103C) and the second connection part (valve holes 104A-104C) that is opposite to the selectable connection part. Furthermore, the opposing connection portion is valve hole 104A if the selected connection portion is valve hole 103A, valve hole 104B if the selected connection portion is valve hole 103B, valve hole 104C if the selected connection portion is valve hole 103C, and the reverse combination (valve hole 103A if the selected connection portion is valve hole 104A) is also possible.

[0108] (9) In the purging method of the valve device described in (8), it is preferable to introduce the purge fluid from the connection part downstream of the opposing connection part into which the purge fluid was introduced, among the first connection part (valve holes 103A-103C) and the second connection part (valve holes 104A-104C). The connection part downstream of the opposing connection part is, for example, if the opposing connection part is valve hole 103A or valve hole 104A, then it is valve holes 103B-103C and 104B-104C, and if the upstream connection part is valve hole 103B or valve hole 104B, then it is valve holes 103C and 104C.

[0109] In the purging method of the valve device described in (10), (7), or (9), it is preferable to introduce the purging fluid sequentially from the upstream side of the main flow path 10.

[0110] In the purging method of the valve device described in (11), (6), or (8), it is preferable that the purging fluid is the same fluid as the main fluid.

[0111] According to the valve device (manifold valve 2) or purging method of the valve device of the present invention, since the second sub-flow channel (purging channel 12A-12D) is provided on the opposite side of the main flow channel 10 from the first sub-flow channel (sub-fluid supply channel 11A-11D), for example, if a sub-fluid (chemical solution) is supplied from the first sub-flow channel (sub-fluid supply channel 11A-11D) to the main flow channel 10, and then a purge fluid is introduced from the second sub-flow channel (purging channel 12A-12D) to the main flow channel 10, the sub-fluid (chemical solution) can be washed away.

[0112] For example, if the second connection point (valve hole 104A-104D) where the second sub-channel (purge channel 12A-12D) connects to the main channel is offset upstream of the main channel 10 relative to the first connection point (valve hole 103A-103D) where the first sub-channel (sub-fluid supply channel 11A-11D) connects to the main channel 10, then the purge fluid introduced into the main channel 10 from the second sub-channel (purge channel 12A-12D) can flow into the first connection point (valve hole 103A-103D) along with the fluid flow in the main channel 10, and wash away any chemical solution remaining in the first connection point (valve hole 103A-103D).

[0113] For example, if the second connection point (valve opening 104A-104D) where the second sub-flow channel (purge flow channel 12A-12D) connects to the main flow channel 10 is provided opposite the first connection point (valve opening 103A-103D) where the first sub-flow channel (sub-fluid supply channel 11A-11D) connects to the main flow channel 10, then by introducing purge fluid from the second sub-flow channel (purge flow channel 12A-12D), the purge fluid can be directly injected into the first connection point (valve opening 103A-103D). This makes it possible to wash away any chemical solution remaining in the first connection point (valve opening 103A-103D). Thus, it is possible to prevent the accumulation of sub-fluid at the connection point (valve openings 103A-103D, 104A-104D) between the main flow channel 10 and the sub-flow channel.

[0114] The embodiments described above are merely illustrative and do not limit the present invention in any way. Therefore, the present invention can naturally be improved and modified in various ways without departing from its essence.

[0115] For example, the flow velocity of the pure water (purge fluid) can be increased by adding a throttling to the purge passage 12A-12C (valve opening 104A-104C). By increasing the flow velocity of the pure water (purge fluid), the pure water (purge fluid) can be more reliably delivered to the valve opening 103A-103C, ensuring thorough flushing.

[0116] Furthermore, in this embodiment, there are four auxiliary fluid supply passages 11A-11C and four purge passages 12A-12C, but the embodiment is not limited to this, and two or more are acceptable. Also, in this embodiment, the internal passage 32 opens to the bottom surface 311 side of the valve chamber 31, but the position of the opening is not limited as long as it communicates with the valve chamber 31. For example, the internal passage 32 may open to the side of the valve chamber 31 instead of the bottom surface 311. For example, the internal passage 32 may open radially outward from the valve body 42 instead of facing the axis of the valve body 42. The resulting turbulence can prevent fluid stagnation in the valve chamber 31 and the first connection part (valve holes 103A-103C).

[0117] 2 Manifold Valve (Example of Valve Device) 10 Main Flow 11A Secondary Fluid Supply 11B Secondary Fluid Supply 11C Secondary Fluid Supply 11D Secondary Fluid Supply 12A Purge Flow 12B Purge Flow 12C Purge Flow 12D Purge Flow 103A Valve Hole 103B Valve Hole 103C Valve Hole 103D Valve Hole 104A Valve Hole 104B Valve Hole 104C Valve Hole 104D Valve Hole

Claims

1. A valve device comprising a main flow path and a sub-flow path connected to the main flow path, wherein the sub-flow path comprises: at least two first sub-flow paths sequentially connected to the main flow path from upstream to downstream of the main flow path; and at least two second sub-flow paths on the opposite side of the main flow path from the first sub-flow paths, and sequentially connected to the main flow path from upstream to downstream of the main flow path.

2. A valve device according to claim 1, wherein the second connection portion, to which the second sub-flow path connects to the main flow path, is offset upstream of the main flow path from the first connection portion to which the first sub-flow path connects to the main flow path, and the first sub-flow path and the second sub-flow path are connected to the main flow path in a staggered manner.

3. A valve device according to claim 1, characterized in that each of the first connection parts to which the first sub-flow path connects to the main flow path and each of the second connection parts to which the second sub-flow path connects to the main flow path are provided opposite to each other.

4. A valve device according to claim 2 or 3, characterized in that the first sub-flow channel is a sub-fluid supply channel that supplies a sub-fluid to the main flow channel for mixing with the main flow channel, and the second sub-flow channel is a purge channel that introduces a purge fluid to the main flow channel for washing away the sub-fluid.

5. A valve device according to claim 2 or 3, characterized in that the main flow path extends linearly from upstream to downstream in the range in which at least the first sub-flow path and the second sub-flow path are connected.

6. A purging method for a valve device, using the valve device described in claim 2, for flushing out a secondary fluid to be mixed with the main body flowing through the main channel, characterized in that, after supplying the secondary fluid to the main channel from a selectable connection part of either the first connection part or the second connection part, a purging fluid for flushing out the secondary fluid is introduced into the main channel from the upstream connection part of the selectable connection part, which is diagonally opposite to the first connection part or the second connection part.

7. A method for purging a valve device according to claim 6, characterized in that the purge fluid is also introduced from the connection portion downstream of the upstream connection portion from which the purge fluid was introduced, among the first connection portion and the second connection portion.

8. A purging method for a valve device, using the valve device described in claim 3, for flushing out a secondary fluid for mixing with the main body flowing through the main channel, characterized in that, after supplying the secondary fluid to the main channel from a selectable connection part among the first connection part and the second connection part, a purging fluid for flushing out the secondary fluid is introduced into the main channel from a counter connection part of the first connection part and the second connection part that is opposite to the selectable connection part.

9. A method for purging a valve device according to claim 8, characterized in that the purge fluid is also introduced from the connection portion of the first connection portion and the second connection portion that is downstream of the opposing connection portion from which the purge fluid was introduced.

10. A method for purging a valve device according to claim 7 or 9, characterized in that the purging fluid is introduced sequentially from the upstream side of the main flow path.

11. A method for purging a valve device according to claim 6 or 8, characterized in that the purging fluid is the same fluid as the main fluid.

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