Fluid control valve and fluid control device

Abstract

The present invention provides a fluid control valve and a fluid control device capable of reducing a dead volume while simplifying a valve structure and being used in a semiconductor manufacturing process, the fluid control valve comprising: a flow path module (2) in which an internal flow path (2R) is formed; a valve seat member (5) having a valve seat surface (5a); and a valve core (6) having a seating surface (6a) seated on the valve seat surface (5a) and provided with a permanent magnet (60). And an actuating part (7) that drives the valve body (6) by acting on a permanent magnet (60) that is sealed by a corrosion-resistant alloy.

Description

Technical Field

[0001] The present invention relates to a fluid control valve and a fluid control device. Background Art

[0002] Conventionally, as a fluid control valve, as shown in Patent Document 1, a so-called power-off closed type (normally open type) solenoid valve has been considered.

[0003] The solenoid valve includes: a valve body having a valve seat; a plunger disposed in the valve body so as to be liftable; an attracting member disposed opposite to the plunger; an electromagnetic coil for exciting the attracting member; a valve element connected to the plunger and disposed so as to be liftable relative to the valve seat; and a biasing member for biasing the plunger in the valve opening direction. By energizing the electromagnetic coil, the plunger moves in the valve closing direction against the action of the biasing member. Specifically, the valve element penetrates the attracting member and is disposed so as to be liftable relative to the valve body provided on the lower side of the attracting member, and is connected to the plunger provided on the upper side of the attracting member, and is always biased upward (valve opening direction) together with the plunger.

[0004] Patent Document 1: Japanese Patent Laid-Open Publication No. 2020-148255

[0005] However, there is a problem that the above-described solenoid valve has a complicated structure and a large dead volume. In particular, when the solenoid valve is used in a supply pipe of a processing gas in a semiconductor manufacturing apparatus, it is desired to reduce the contact area with the processing gas. However, in the above-described solenoid valve, the dead volume is large and it is difficult to reduce the contact area. Summary of the Invention

[0006] Here, the main object of the present invention is to solve the above problems, simplify the valve structure while reducing the dead volume, and can be used in semiconductor manufacturing processes.

[0007] That is, the fluid control valve of the present invention includes: a flow path module formed with an internal flow path; a valve seat member having a valve seat surface; a valve element having a seating surface seated on the valve seat surface and provided with a permanent magnet; and an actuating portion for driving the valve element by acting on the permanent magnet, and the permanent magnet is encapsulated by a corrosion-resistant alloy.

[0008] In the present specification, the corrosion-resistant alloy is, for example, corrosion-resistant to gases used in semiconductor manufacturing processes. Specifically, it is a compound containing halogen gases or halogen elements such as fluorine (F2), chlorine (Cl2), bromine (Br2), iodine (I2), etc., and is corrosion-resistant to halogen-based gases such as HCl. In addition, the corrosion-resistant alloy is a material different from the permanent magnet and has higher corrosion resistance than the permanent magnet. It is further preferably more corrosion-resistant to the gases used in semiconductor processes than the permanent magnet. Specifically, it includes halogen gases or compounds of halogen elements such as fluorine (F2), chlorine (Cl2), bromine (Br2), iodine (I2), etc. For example, it is more corrosion-resistant to halogen-based gases such as HCl than the permanent magnet. In addition to being corrosion-resistant to the above gases, the corrosion-resistant alloy is further preferably corrosion-resistant to reaction products (mainly strong acids) and aqueous solutions generated when halogen gases or halogen-based gases react with moisture.

[0009] According to such a fluid control valve, since a permanent magnet is provided on the valve core and the valve core is driven by acting on the permanent magnet, compared with the existing structure using a plunger, the valve structure can be simplified, and in addition, the dead volume can be reduced. Especially in the present invention, the permanent magnet is encapsulated by a corrosion-resistant alloy, so even when used in semiconductor manufacturing processes, the above-mentioned processing gases can be prevented from corroding the permanent magnet. Therefore, the fluid control valve of the present invention can be applied to the supply pipeline of processing gases in semiconductor manufacturing devices, and the contact area with the processing gases can be reduced.

[0010] As a specific embodiment of the actuating part, it can be considered that the actuating part includes: an iron core disposed on the opposite side of the valve core with respect to the seating surface; and an electromagnetic coil wound around the iron core. In the above structure, when the fluid control valve is a so-called power-off closed type (normally open type), when the electromagnetic coil is not energized, the permanent magnet is adsorbed to the iron core, and the valve core is in a fully open state. When the electromagnetic coil is energized, the iron core and the permanent magnet repel each other, and the valve core moves in the valve closing direction.

[0011] As a specific embodiment of encapsulating the permanent magnet with a corrosion-resistant alloy, it is preferably that the valve core includes: a valve core body made of a corrosion-resistant alloy, and a concave portion for accommodating the permanent magnet is formed on the surface opposite to the seating surface; and an encapsulating member made of a corrosion-resistant alloy, which encapsulates the opening of the concave portion in a state where the permanent magnet is accommodated in the concave portion. According to the above structure, by simply accommodating the permanent magnet in the concave portion of the valve core body and encapsulating it with the encapsulating member, the permanent magnet can be encapsulated with a corrosion-resistant alloy, and the structure of the valve core can be simplified.

[0012] As a specific example of the corrosion-resistant alloy, stainless steels such as SUS316L can be cited.

[0013] The iron core of the actuating part is disposed opposite to the surface of the valve element on the side opposite to the seating surface. In order not to interfere with the magnetic coupling between the iron core and the permanent magnet, it is preferable that the encapsulation member is formed of non-magnetic stainless steel. In addition, in order for the valve element main body to function as a magnetic yoke (yoke iron) and further strengthen the magnetic coupling between the iron core and the permanent magnet, it is preferable that the valve element main body is formed of electromagnetic stainless steel.

[0014] In addition, the fluid control valve of the present invention preferably further includes a distance adjustment mechanism that adjusts the distance between the iron core and the valve element. By adjusting the distance between the iron core and the valve element by the distance adjustment mechanism, the optimal magnetic field (magnetic flux density) can be adjusted (increased or decreased). For example, when it is desired to control a minute flow rate, by separating the iron core from the valve element, the magnetic coupling between the iron core and the valve element is weakened, and the control of the minute flow rate can be achieved.

[0015] As a specific embodiment of the fluid control valve, the fluid control valve further includes a mounting module that is mounted on the flow path module and houses the valve element. The actuating part has a housing that houses the iron core and the electromagnetic coil, and the iron core is fixed to the housing. According to the above structure, by removing the mounting module from the flow path module, the actuating part and the valve element can be removed together, so that it is easy to disassemble and easy to repair. In addition, by mounting the housing on the mounting module, the surface of the iron core opposite to the seating surface of the valve element is disposed opposite. In the above structure, as a specific embodiment of the distance adjustment mechanism, it is preferable that the distance adjustment mechanism is composed of the housing and the mounting module.

[0016] As a specific embodiment of the distance adjustment mechanism, it can be considered to include: an external thread portion formed on one of the outer circumferential surface of the housing and the mounting module; and an internal thread portion formed on the other of the outer circumferential surface of the housing and the mounting module and threadedly connected to the external thread portion. According to the above structure, by a simple operation of rotating the housing relative to the mounting module, the distance between the iron core and the valve element can be adjusted.

[0017] It is preferable that the mounting module is provided with a fixing portion that is provided to be able to advance and retreat relative to the housing and fixes the housing relative to the mounting module. According to the above structure, after adjusting the distance between the iron core and the valve element by the distance adjustment mechanism, the housing is fixed by the fixing portion, and the distance between the iron core and the valve element can be reliably maintained.

[0018] As a specific embodiment of fixing the housing with the fixing portion, it is preferable that the housing has a cylindrical end portion at the front end on the side of the flow path module, the mounting module has a slit for receiving the cylindrical end portion, the fixing portion is provided on the side wall portion of the mounting module that forms the slit, and the cylindrical end portion is fixed to the side wall portion of the mounting module that forms the slit by the fixing portion.

[0019] In order to facilitate the disassembly and assembly of the fluid control valve for easy maintenance, it is preferable that the flow path module has a receiving recess for receiving the valve seat member.

[0020] In addition, in order to facilitate the assembly of the fluid control valve, it is preferable that the mounting module is mounted on the flow path module to fix the valve seat member received in the receiving recess.

[0021] In addition, the fluid control device of the present invention includes: the above-mentioned fluid control valve; a fluid sensor that measures the flow rate or pressure of the fluid; and a control unit that controls the opening degree of the fluid control valve according to the measured value measured by the fluid sensor and a predetermined target value.

[0022] The present invention having the above structure can reduce the dead volume while simplifying the valve structure and is used in semiconductor manufacturing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram showing a fluid control device according to an embodiment of the present invention. Figure 2 It is a cross-sectional view of the fluid control valve of the same embodiment. Figure 3 It is a perspective view and a cross-sectional view showing the valve core structure of the same embodiment. Figure 4 It is a partially enlarged cross-sectional view of the fluid control valve (open valve state) of the same embodiment. Figure 5 It is a partially enlarged cross-sectional view of the fluid control valve (closed valve state) of the same embodiment. Figure 6 It is a partially enlarged cross-sectional view showing the state before and after distance adjustment of the same embodiment. Figure 7 It is a partially enlarged cross-sectional view of the fluid control valve (open valve state) of a modified embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of a fluid control device using the fluid control valve of the present invention will be described with reference to the drawings. In addition, for easy understanding, appropriate omissions or exaggerated schematic representations are made in all the drawings shown below. The same reference numerals are assigned to the same structural components and the description is appropriately omitted.

[0025] (Device Structure) The fluid control device 100 of the present embodiment is applied to a semiconductor manufacturing process, for example, by being assembled to a semiconductor manufacturing device. For example, it is provided on one or more gas supply pipes connected to a semiconductor processing chamber to control the flow rate of the processing gas flowing in each gas supply pipe.

[0026] The specific fluid control device 100 is a so-called differential pressure type mass flow controller (differential pressure type MFC), as Figure 1 shown, and includes: a flow channel module 2 formed with an internal flow channel 2R; and a fluid control device 3 including a flow rate sensor 31 and a fluid control valve 32 mounted on the flow channel module 2.

[0027] The flow channel module 2 is a rectangular member, and the flow rate sensor 31 and the fluid control valve 32 are provided on a predetermined surface. In addition, a concave receiving recess 2M for mounting the fluid control valve 32 is formed in the flow channel module 2, and the internal flow channel 2R is divided into an upstream side flow channel 2R1 and a downstream side flow channel 2R2 by the receiving recess 2M. Moreover, in the receiving recess 2M, one end of the upstream side flow channel 2R1 opens, for example, on the bottom surface, and one end of the downstream side flow channel 2R2 opens, for example, on the bottom surface.

[0028] The fluid control device 3 controls the fluid in the internal flow channel 2R, and has a flow rate sensor 31 for measuring the flow rate of the fluid flowing in the internal flow channel 2R and a fluid control valve 32 provided on the upstream side of the flow rate sensor 31. In addition, the valve opening degree of the fluid control valve 32 is feedback-controlled by a control unit 4 described later.

[0029] The flow rate sensor 31 is a differential pressure type flow rate sensor, and includes: an upstream side pressure sensor 31a provided on the upstream side of a flow resistance element 33 such as a throttle or a throttle hole in the internal flow channel 2R; and a downstream side pressure sensor 31b provided on the downstream side of the flow resistance element 33. The upstream side pressure sensor 31a, the downstream side pressure sensor 31b, and the fluid control valve 32 are mounted in a row on a predetermined surface of the flow channel module 2. Moreover, a flow rate calculation unit 4a of the control unit 4 described later calculates the flow rate Q flowing in the internal flow channel 2R using the upstream side pressure P1 of the flow resistance element 33 detected by the upstream side pressure sensor 31a and the downstream side pressure P2 of the flow resistance element 33 detected by the downstream side pressure sensor 31b.

[0030] The fluid control valve 32 is provided on the upstream side of the differential pressure type flow sensor 31. Specifically, the fluid control valve 32 is a solenoid valve that controls the flow rate by moving a valve element forward and backward relative to a valve seat by using an electromagnetic element. In the present embodiment, it is a normally open type valve that becomes a fully open state when the valve element is not driven. In addition, the fluid control valve 32 is controlled by the valve control unit 4b of the control unit 4. The detailed structure of the fluid control valve 32 will be described later.

[0031] The control unit 4 includes: a flow rate calculation unit 4a that calculates the flow rate Q flowing in the internal flow path 2R based on the upstream side pressure P1 and the downstream side pressure P2; and a valve control unit 4b that controls the fluid control valve 32 based on the flow rate Q calculated by the flow rate calculation unit 4a and the target flow rate (set value). In addition, the control unit 4 is a so-called computer that includes, for example, a CPU, a memory, A / D and D / A converters, and an input / output unit, and functions as the flow rate calculation unit 4a, the valve control unit 4b, etc. by executing a flow rate control program stored in the memory and causing various devices to cooperate.

[0032] (Detailed structure of the fluid control valve 32) As Figures 2 to 5 shown, the fluid control valve 32 of the present embodiment includes: a valve seat member 5 having a planar valve seat surface 5a; a valve element 6 having a planar seating surface 6a that is in surface contact with and seats on the valve seat surface 5a, and provided with a permanent magnet 60; and an actuator 7 that magnetically drives the valve element 6 by acting on the permanent magnet 60.

[0033] As Figure 2 and Figure 3 shown, the valve seat member 5 has a substantially rotating body shape and is housed in the housing recess 2M of the flow path module 2. Moreover, the valve seat member 5 forms an annular valve seat surface 5a on the upper surface facing the opening side of the housing recess 2M. In addition, the valve seat member 5 is formed of a non-magnetic body such as austenitic stainless steel (non-magnetic stainless steel) such as SUS316L.

[0034] In addition, a through hole 51 is formed in the valve seat member 5, and the through hole 51 penetrates from the valve seat surface 5a side to the opposite side of the valve seat surface 5a inside the valve seat surface 5a and at its central portion. The through hole 51 communicates with the upstream side flow path 2R1 that opens at the bottom surface of the housing recess 2M. In addition, a sealing member S1 such as an O-ring is provided between the periphery of the through hole 51 and the bottom surface of the housing recess 2M, so as to be liquid-tightly sealed.

[0035] Moreover, a discharge passage 52 is formed in the valve seat member 5, and the discharge passage 52 allows the fluid flowing into the interior from the valve seat surface 5a to flow out to the downstream flow passage 2R2. The discharge passage 52 of the present embodiment is a through hole that penetrates from the valve seat surface 5a side to the opposite side of the valve seat surface 5a outside the valve seat surface 5a. The discharge passage 52 communicates with the upstream flow passage 2R1 that opens at the bottom surface of the accommodation recess 2M.

[0036] As Figures 2 to 5 shown, the valve element 6 has a substantially rotating body shape and is disposed opposite to the valve seat member 5 accommodated in the accommodation recess 2M. In addition, the permanent magnet 60 provided on the valve element 6 has a disc shape and is encapsulated by a corrosion-resistant alloy that is resistant to the gas used in the semiconductor process. Here, as the permanent magnet 60, for example, alloy magnets such as alnico magnets, ferrite magnets, or rare earth magnets such as neodymium magnets can be used.

[0037] Specifically, the valve element 6 includes: a valve element main body 61, in which a recess 61M for accommodating the permanent magnet 60 is formed on the surface opposite to the seating surface 6a; and an encapsulating member 62 that encapsulates the opening of the recess 61M in a state where the permanent magnet 60 is accommodated in the recess 61M. In the present embodiment, the permanent magnet 60 is encapsulated by the valve element main body 61 and the encapsulating member 62.

[0038] The valve element main body 61 has a substantially rotating body shape and has a protruding portion 611, and the protruding portion 611 has a planar seating surface 6a on the top surface. The seating surface 6a of the valve element main body 61 of the present embodiment is formed in a circular shape corresponding to the annular valve seat surface 5a. In addition, the recess 61M has a shape corresponding to the permanent magnet 60, and in the present embodiment, it is a recess that is substantially circular in plan view. The valve element main body 61 is formed of a corrosion-resistant alloy such as stainless steel that is resistant to the gas used in the semiconductor process. The valve element main body 61 of the present embodiment is formed of a magnetic material such as electromagnetic stainless steel such as KM45 in order to function as a magnetic yoke (yoke iron).

[0039] The encapsulating member 62 has a substantially disc shape and corresponds to the opening shape of the recess 61M. The encapsulating member 62 encapsulates the opening of the recess 61M and seals the recess 61M so that the permanent magnet 60 accommodated in the recess 61M is not corroded. In addition, the encapsulating member 62 is joined to the opening of the recess 61M by welding such as laser welding. In addition, the encapsulating member 62 can also be mechanically joined or adhesively joined to the opening of the recess 61M. The encapsulating member 62 is formed of a corrosion-resistant alloy such as stainless steel that is resistant to the gas used in the semiconductor process. The encapsulating member 62 of the present embodiment is formed of a non-magnetic material such as austenitic stainless steel (non-magnetic stainless steel) such as SUS316L so as not to interfere with the magnetic coupling between the iron core 71 and the permanent magnet 60.

[0040] The valve core 6 is housed in the mounting module 8, and the mounting module 8 is mounted on a predetermined surface (upper surface) of the flow path module 2. Additionally, the mounting module 8 is formed of a non-magnetic material such as austenitic stainless steel (non-magnetic stainless steel) like SUS316L. Moreover, the valve core 6 is supported by a support member 9 in the mounting module 8, and the support member 9 is constituted by an elastic body such as a leaf spring. The support member 9 supports the valve core 6 with the seating surface 6a of the valve core 6 facing the valve seat surface 5a side. Specifically, the support member 9 is in an annular shape, and supports the valve core 6 by inserting the protruding portion 611 of the valve core 6 through its central opening 91. In addition, the support member 9 and the valve core 6 may also be integrally formed by welding such as laser welding. Additionally, the joining of the support member 9 and the valve core 6 into one body may also be a mechanical joining or an adhesive joining. Moreover, the support member 9 is formed of a non-magnetic material such as austenitic stainless steel like SUS316L. And the support member 9 is formed of a material having elasticity and considering the magnetic permeability and having corrosion resistance suitable for the semiconductor contact portion.

[0041] In addition, by being mounted on the flow path module 2, the mounting module 8 fixes the valve seat member 5 housed in the housing recess 2M. Specifically, the surface (lower surface) of the mounting module 8 facing the flow path module 2 contacts the upper surface of the valve seat member 5, and presses and fixes the lower surface of the valve seat member 5 to the bottom surface of the housing recess 2M by means of a sealing member S1. Additionally, a sealing member S2 such as a metal seal is provided between the mounting module 8 and the flow path module 2 and is liquid-tightly sealed.

[0042] As Figure 2 , Figure 4 and Figure 5 shown, the actuating portion 7 includes: an iron core 71 disposed opposite to the surface 6b of the valve core 6 on the side opposite to the seating surface 6a; an electromagnetic coil 72 wound around the iron core 71; and a housing 73 housing the iron core 71 and the electromagnetic coil 72.

[0043] The iron core 71 is in a substantially cylindrical shape, one end portion (the upper end portion in Figure 2 ) is connected to the housing 73, and the other end portion (the lower end portion in Figure 2 ) is opposite to the surface 6b of the valve core 6 on the side opposite to the seating surface 6a. Specifically, the other end portion of the iron core 71 is opposite to the surface 6b on the opposite side in a coaxial manner with the permanent magnet 60 provided in the valve core 6. Additionally, the iron core 71 is formed of a magnetic material such as carbon steel for mechanical structures like S45C.

[0044] The electromagnetic coil 72 is wound and arranged so as to surround the outer circumferential surface of the iron core 71, and is specifically wound around a bobbin 721 through which the iron core 71 is inserted. Here, the bobbin 721 is arranged to be slidable relative to the iron core 71. Additionally, the bobbin 721 is formed of a non-magnetic material such as austenitic stainless steel like SUS316L.

[0045] The housing 73 has a cylindrical shape, and its upper wall portion is connected to the upper end portion of the iron core 71. In addition, an elastic body 74 such as a wave spring is provided between the upper wall portion of the housing 73 and the electromagnetic coil 72 (specifically, the upper end portion of the solenoid tube 721) (refer to Figure 2 ). In addition, the housing 73 is formed of a magnetic material such as carbon steel for mechanical structures such as S45C. In addition, the housing 73 and the iron core 71 may be integrally formed.

[0046] In addition, the housing 73 is mounted on the mounting module 8. By mounting the housing 73 on the mounting module 8, the iron core 71 connected to the housing 73 is disposed opposite to the surface 6b of the valve element 6 on the side opposite to the seating surface 6a.

[0047] Moreover, the housing 73 extends to a position surrounding the valve element 6, forming a magnetic path that guides the magnetic flux generated by the electromagnetic coil 72 to the periphery of the valve element 6. The position surrounding the valve element 6 is a position facing the outer peripheral surface of the valve element 6 in a direction perpendicular to the advancing and retreating direction of the valve element 6. With this structure, the surface 6b of the valve element 6 on the side opposite to the seating surface 6a (the upper surface in Figure 2 and Figure 3 is located closer to the iron core 71 side (upper side) than the front end surface on the flow path module 2 side in the housing 73 (the lower surface in Figure 2 and Figure 3 ). Specifically, the housing 73 extends to a position surrounding at least the upper half of the outer peripheral surface of the valve element 6 around the valve element 6 in the closed valve state.

[0048] Moreover, in the present embodiment, as shown in Figure 2 , Figure 4 and Figure 5 , a distance adjustment mechanism 10 for adjusting the distance between the iron core 71 and the valve element 6 is provided. In addition, by adjusting the distance between the iron core 71 and the valve element 6 by the distance adjustment mechanism 10, the distance between the iron core 71 and the permanent magnet 60 is adjusted.

[0049] The distance adjustment mechanism 10 adjusts the distance between the opposing surfaces of the iron core 71 and the valve element 6. The distance adjustment mechanism 10 is interposed between the housing 73 and the mounting module 8 and is constituted by the housing 73 and the mounting module 8. Here, the opposing surfaces of the iron core 71 and the valve element 6 are the lower end surface 71a of the iron core 71 and the surface 6b of the valve element 6 on the side opposite to the seating surface 6a.

[0050] Specifically, the distance adjustment mechanism 10 includes an external thread portion 10a formed on the outer peripheral surface of the housing 73; and an internal thread portion 10b formed on the mounting module 8 and threadedly connected to the external thread portion 10a. With this structure, the housing 73 is mounted on the mounting module 8 by threadedly connecting the external thread portion 10a and the internal thread portion 10b. In addition, as shown in Figure 7As shown, by rotating the housing 73 relative to the mounting module 8, the housing 73 is axially advanced and retracted relative to the mounting module 8, thereby adjusting the distance between the opposite faces of the iron core 71 and the valve element 6.

[0051] Here, as shown in Figure 2 and Figures 4 to 6 , a fixing screw 11 is provided on the side wall portion 81 formed with an internal thread portion 10b. The fixing screw 11 is a fixing portion for fixing the housing 73 relative to the mounting module 8 and is provided so as to be able to advance and retract relative to the housing 73. The fixing screw 11 can advance and retract in a direction perpendicular to the moving direction in which the housing 73 moves through the distance adjusting mechanism 10.

[0052] Specifically, as shown in Figure 2 and Figures 4 to 6 , the housing 73 has a cylindrical end portion 73x at the front end portion on the flow path module side relative to the external thread portion 10a. The fixing screw 11 fixes the housing 73 relative to the mounting module 8 by pressing contact with the cylindrical end portion 73x. The cylindrical end portion 73x of the present embodiment has the same diameter as the housing main body portion 73y that houses the electromagnetic coil 72 in the housing 73. That is, the housing 73 does not have a flange portion for mounting to the mounting module 8.

[0053] More specifically, as shown in Figure 4 and Figure 5 , the mounting module 8 has an annular slit 8S that houses the cylindrical end portion 73x. The fixing screw 11 is provided on the side wall portion 811 formed on the radially outer side of the slit 8S. In addition, the side wall portion 812 formed on the radially inner side of the slit 8S surrounds the outer peripheral surface of the valve element 6. Moreover, the cylindrical end portion 73x is pressed and fixed by the fixing screw 11 to the side wall portion 812 for forming the radially inner side of the slit 8S.

[0054] The present embodiment is configured such that even if the housing 73 and the iron core 71 are moved relative to the mounting module 8 by the above-described distance adjusting mechanism 10, the relative position of the electromagnetic coil 72 and the mounting module 8 (valve element 6) does not change (refer to Figure 6 ). Specifically, the electromagnetic coil 72 is provided so as to be able to slide relative to the iron core 71 and the housing 73. In addition, it is configured to be pressed toward the mounting module 8 by a wave spring 74 provided between the upper wall portion of the housing 73 and the electromagnetic coil 72 (the upper end portion of the bobbin 721). The wave spring 74 absorbs dimensional tolerances and fixes the electromagnetic coil 72. Additionally, as long as the dimensional accuracy of each component is achieved, the wave spring 74 may not be provided.

[0055] In addition, as shown in Figure 4 and Figure 5As shown, a diaphragm seal 12 is provided between the lower end surface of the bobbin 721 and the upper end surface of the mounting module 8 to liquid-tightly seal between the lower end surface of the bobbin 721 and the upper end surface of the mounting module 8. In addition, the diaphragm seal 12 is formed of a non-magnetic material such as austenitic stainless steel such as SUS316L.

[0056] Next, the operation of the fluid control valve 32 of the present embodiment will be briefly described.

[0057] In a state where no current flows through the electromagnetic coil 72 of the actuator 7 (when not energized), the permanent magnet 60 provided on the valve element 6 is attracted to the iron core 71, and the valve element 6 is in a fully open state. In the present embodiment, the iron core 71 and the permanent magnet 60 are attracted to each other via the encapsulation member 62 and the diaphragm seal 12.

[0058] Then, when a current flows through the electromagnetic coil 72, the electromagnetic coil 72 generates a magnetic flux, thereby magnetizing the iron core 71. Here, when the iron core side of the permanent magnet 60 is the N pole, the lower end portion of the iron core 71 is magnetized to the N pole, and when the iron core side of the permanent magnet 60 is the S pole, the lower end portion of the iron core 71 is magnetized to the S pole. In this way, the magnetized iron core 71 repels the permanent magnet 60, causing the valve element 6 to move in the valve closing direction. In addition, the valve opening of the fluid control valve 32 is adjusted by controlling the current supplied to the electromagnetic coil 72.

[0059] (Effects of the present embodiment) In the fluid control device 100 of the present embodiment configured as described above, since the permanent magnet 60 is provided in the valve element 6 and the valve element 6 is driven by acting on the permanent magnet 60, the valve structure can be simplified compared to the conventional structure using a plunger, and in addition, the dead volume can be reduced. In particular, in the present embodiment, the permanent magnet 60 is encapsulated by a corrosion-resistant alloy, so even when used in a semiconductor manufacturing process, the permanent magnet 60 can be prevented from being corroded by the above-mentioned processing gas. Therefore, the fluid control valve 32 of the present embodiment can be applied to the supply pipe of the processing gas in a semiconductor manufacturing apparatus, and the contact area with the processing gas can be reduced.

[0060] In addition, according to the present embodiment, since the encapsulation member 62 is formed of non-magnetic stainless steel, the magnetic coupling between the iron core 71 and the permanent magnet 60 is not hindered. Moreover, since the valve element main body 61 is formed of electromagnetic stainless steel, the valve element main body 61 functions as a magnetic yoke (yoke iron), and the magnetic coupling between the iron core 71 and the permanent magnet 60 can be further strengthened.

[0061] Moreover, according to this embodiment, since the distance adjustment mechanism 10 for adjusting the distance between the iron core 71 and the valve element 6 is provided, by using the distance adjustment mechanism 10 to adjust the distance between the iron core 71 and the valve element 6, it is possible to adjust (increase or decrease) to the optimal magnetic field (magnetic flux density). For example, when micro flow control is desired, by separating the distance between the iron core 71 and the valve element 6 and weakening the magnetic coupling between the iron core 71 and the valve element 6, the control of micro flow can be achieved.

[0062] (Other embodiments) For example, in addition to the structure in which the permanent magnet 60 is encapsulated by the valve element main body 61 and the encapsulation member 62, it may also be a structure in which the outer surface of the permanent magnet 60 is covered by a covering member made of a corrosion-resistant alloy and fixed to the valve element 6. By separately covering the permanent magnet 60 apart from the structure of the valve element 6, it is also possible to prevent the permanent magnet from being corroded.

[0063] In addition, in addition to the valve element main body 61 being made of electromagnetic stainless steel, a part or all of the valve element main body 61 may be made of non-magnetic stainless steel. According to the said structure, the material cost of the valve element 6 can be reduced.

[0064] The distance adjustment mechanism 10 of the above embodiment is composed of an external thread portion 10a and an internal thread portion 10b, but as Figure 7 shown, it may also be composed of a fixing screw 11. At this time, the mounting module 8 is formed with an annular slit 8S for accommodating the cylindrical end portion 73x, and the cylindrical end portion 73x is adjusted in the vertical direction in the slit 8S and fixed with the fixing screw 11.

[0065] In addition, it may also be a structure in which the external thread portion 10a and the internal thread portion 10b of the distance adjustment mechanism 10 of the above embodiment are inverted, that is, an external thread portion 10a is formed on the mounting module 8, and an internal thread portion 10b is formed on the inner circumferential surface of the housing 73.

[0066] Moreover, the fluid control valve 32 of the said embodiment may be a so-called normally-closed valve that becomes a fully closed state without driving the valve element 6 in addition to the normally-open valve. In the normally-closed structure, in a state where no current flows through the electromagnetic coil 72, for example, the valve element 6 is urged against the valve seat member 5 by an elastic body such as the support member 9 to become a fully closed state. And when current flows through the electromagnetic coil 72, the iron core 71 and the permanent magnet 60 are attracted, and the valve element 6 is moved in the valve-opening direction.

[0067] In addition, according to the above embodiment, the fluid control valve 32 is provided on the upstream side of the flow sensor 31, but it may also be provided on the downstream side of the flow sensor 31.

[0068] In addition, in the above-described embodiment, a pressure type flow sensor is used as the flow sensor 31 of the fluid control device 100, but a thermal type flow sensor may also be used. In this case, it may be considered to dispose the thermal type flow sensor on the upstream side of the fluid control valve 32. In addition, other than the flow sensor, a fluid sensor such as a pressure sensor may also be used.

[0069] Furthermore, the fluid control device 100 is not limited to the pressure type and thermal type. A position sensor for measuring the relative position between the valve seat surface 5a and the seating surface 6a may be provided in the fluid control valve 32, and the valve opening degree may be feedback-controlled based on the measurement value of the position sensor. In addition, the fluid control device of the present invention is not limited to the flow control device of the above-described embodiment, and may also be applied to a pressure control device for controlling the pressure of a fluid.

[0070] In addition, within the scope not departing from the spirit of the present invention, various modifications and combinations of the embodiments may be made. Industrial Applicability

[0071] According to the present invention, it is possible to reduce the dead volume while simplifying the valve structure and use it in a semiconductor manufacturing process. Explanation of Reference Numerals

[0072] 100 Fluid control device 2 Flow path module 2R Internal flow path 2M Receiving recess 32 Fluid control valve 31 Fluid sensor 4 Valve control unit 5 Valve seat member 5a Valve seat surface 6 Valve core 6a Seating surface 60 Permanent magnet 61 Valve core body 62 Encapsulation member 7 Actuating unit 71 Iron core 72 Electromagnetic coil 73 Housing 73x Cylindrical end 8 Mounting module 8S Annular slit 811 Radially outer side wall portion 812 Radially inner side wall portion 10 Distance adjusting mechanism 10a External thread portion 10b Internal thread portion 11 Fixing screw.

Claims

1. A fluid control valve, characterized in that, Comprising: A runner module, formed with an internal runner; A valve seat member, having a valve seat surface; A valve core, having a seating surface seated on the valve seat surface and provided with a permanent magnet; and An actuating part, driving the valve core by acting on the permanent magnet, The permanent magnet is encapsulated by a corrosion-resistant alloy.

2. The fluid control valve according to claim 1, characterized in that, The actuating part includes: An iron core, disposed on the side opposite to the seating surface with respect to the valve core; and An electromagnetic coil, wound around the iron core, When the electromagnetic coil is not energized, the permanent magnet is adsorbed to the iron core, and the valve core is in a fully open state, When the electromagnetic coil is energized, the iron core and the permanent magnet repel each other, and the valve core moves in the valve closing direction.

3. The fluid control valve according to claim 1 or 2, characterized in that, The valve core includes: A valve core body, made of a corrosion-resistant alloy, and having a recess for accommodating the permanent magnet formed on the surface opposite to the seating surface; and An encapsulating member, made of a corrosion-resistant alloy, and encapsulating the opening of the recess in a state where the permanent magnet is accommodated in the recess.

4. The fluid control valve according to any one of claims 1 to 3, characterized in that, The corrosion-resistant alloy is stainless steel.

5. The fluid control valve according to claim 3, characterized in that, The valve core body is formed of electromagnetic stainless steel, The encapsulating member is formed of non-magnetic stainless steel.

6. The fluid control valve according to claim 2, characterized in that, A distance adjusting mechanism is further provided, and the distance adjusting mechanism adjusts the distance between the iron core and the valve core.

7. The fluid control valve according to claim 6, characterized in that, An installation module is further provided, and the installation module is installed on the runner module and houses the valve core, The actuating part has a housing for housing the iron core and the electromagnetic coil, The iron core is fixed to the housing, The distance adjusting mechanism is composed of the housing and the installation module.

8. The fluid control valve according to claim 7, characterized in that, The distance adjusting mechanism includes: An external thread part, formed on one of the outer circumferential surface of the housing and the installation module; and An internal thread part, formed on the other of the outer circumferential surface of the housing and the installation module and threadedly connected to the external thread part.

9. The fluid control valve according to claim 8, characterized in that, The installation module is provided with a fixing part, and the fixing part is arranged to be able to move forward and backward relative to the housing and fix the housing relative to the installation module.

10. The fluid control valve according to claim 9, characterized in that, The housing has a cylindrical end portion at the front end on the side of the runner module, The installation module has a slit for housing the cylindrical end portion, The side wall portion of the installation module forming the slit is provided with the fixing part, The cylindrical end portion is fixed to the side wall portion of the installation module forming the slit through the fixing part.

11. The fluid control valve according to any one of claims 7 to 10, characterized in that, The runner module has a receiving recess for receiving the valve seat member.

12. The fluid control valve according to claim 11, characterized in that, The installation module fixes the valve seat member received in the receiving recess by being installed on the runner module.

13. A fluid control device, characterized in that, Comprising: The fluid control valve according to any one of claims 1 to 12; A fluid sensor, measuring the flow rate or pressure of a fluid; And A control part, controlling the opening degree of the fluid control valve according to the measured value measured by the fluid sensor and a predetermined target value.

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