JP6193955B2 - Fluid control valve - Google Patents

Description

  The present invention relates to a fluid control valve and a fluid control method for controlling a fluid.

  For example, in a semiconductor manufacturing apparatus, a fluid control valve that controls fluid by bringing a valve body into contact with or away from a valve seat is used. In this type of fluid control valve, a liquid contact portion such as a valve body or a valve seat is formed of resin in order to ensure corrosion resistance. If particles are contained in the chemical solution, the yield rate of the product is lowered. Therefore, the conventional fluid control valve is configured to press the flat contact surface of the heating member against the valve seat surface of the valve seat with which the valve body abuts, and then separate the heating member from the valve seat surface. The molding defects are eliminated so that particles are not generated (see, for example, Patent Document 1).

JP 2011-122718 A

  Particle countermeasures in conventional fluid control valves have been able to reduce the impact on conventional semiconductor manufacturing. However, semiconductor devices are miniaturized every year, and accordingly, particles affecting semiconductor manufacturing are miniaturized. As semiconductor devices become finer, it is necessary to reduce finer particles. For example, 20 nm particles that can be measured with a commercially available particle counter are problematic.

  The present invention has been made to solve the above-described problems, and provides a fluid control valve and a fluid control method capable of reducing the generation of particles by suppressing wear caused by deformation of a valve body that occurs when the valve is closed. For the purpose.

One embodiment of the present invention has the following configuration.
(1) having a drive part, a valve body having a first port, a second port, and a valve seat; and a valve body formed in a column shape and connected to the drive part; An annular seal projection provided on the end of the valve seat, which is annularly projected on the end face of the valve seat and is pressed against the valve seat for sealing, and at least the annular seal projection is made of a fluororesin. That is, when the annular seal portion is pressed against the valve seat by the drive unit, the valve body has a displacement amount that the annular seal portion is displaced in the radial direction is not less than 3.224 μm and not more than 6.175 μm. The fluid control valve is characterized.

(2) a drive unit, a valve body having a first port, a second port, and a valve seat; a valve body formed in a column shape and connected to the drive unit; and the valve body on a valve seat side An annular seal projection provided on the end of the valve seat, which is annularly projected on the end face of the valve seat and is pressed against the valve seat for sealing, and at least the annular seal projection is made of a fluororesin. When the annular seal portion is pressed against the valve seat by the drive unit, the valve body has a displacement amount that the annular seal portion is displaced in the radial direction when the valve seat is not in contact with the valve seat. The fluid control valve is characterized in that it is 6.45 × 10 ⁻⁴ times or more and 12.4 × 10 ⁻⁴ times or less with respect to the diameter of the annular seal portion.
Here, “the diameter of the annular seal portion when not in contact with the valve seat” is the radial center of the annular seal portion not in contact with the valve seat when the annular seal portion is formed with a flat surface. The diameter of the position. Moreover, when an annular seal part is R shape, the diameter of the vertex part of the annular seal part which is not contact | abutting to a valve seat is said.

(3) having a drive part, a valve body having a first port, a second port, and a valve seat; and a valve body formed in a column shape and connected to the drive part; An annular seal protrusion projecting annularly on the end face on the valve seat side, at least the annular seal protrusion is made of a fluororesin, and is pressed against the valve seat at the tip of the annular seal protrusion to seal The annular seal portion is formed flat, and the valve body has a displacement amount in which the annular seal portion is displaced in the radial direction when the annular seal portion is pressed against the valve seat by the drive portion. The fluid control valve is characterized in that it is 3.22 × 10 ⁻² times or more and 6.18 × 10 ⁻² times or less the width dimension of the annular seal portion when it is not in contact with the valve seat.

(4) having a drive unit, a valve body having a first port, a second port, and a valve seat; and a valve body formed in a column shape and connected to the drive unit; An annular seal projection provided on the end of the valve seat, which is annularly projected on the end face of the valve seat and is pressed against the valve seat for sealing, and at least the annular seal projection is made of a fluororesin. The fluid control valve is characterized in that the diameter of the end face on the valve seat side is not less than 1.3 times the diameter of the annular seal portion when not in contact with the valve seat.
Here, “the diameter of the annular seal portion when not in contact with the valve seat” is the diameter of the annular seal portion not in contact with the valve seat when the annular seal portion is formed with a flat surface. The diameter at the center of the direction. Moreover, when an annular seal part is R shape, the diameter of the vertex part of the annular seal part which is not contact | abutting to a valve seat is said.

(5) In the configuration according to any one of (1) to (4), it is preferable that the valve body has a narrowest diameter smaller than a diameter of the annular seal portion.

(6) In the configuration described in (5), the valve body has an axial thickness at a radial center position of the annular seal portion of 0.7 times or more with respect to the diameter of the annular seal portion. It is preferable.

(7) In the configuration described in (5) or (6), it is preferable that the valve body has a convex portion that protrudes in the valve seat direction from the valve seat side end surface inside the annular seal protrusion.

(8) In the configuration described in (7), it is preferable that the convex portion has a diameter of a base end portion connected to the valve seat side end surface equal to or larger than a diameter of a thinnest portion of the valve body.

(9) In the configuration according to any one of (1) to (8), it is preferable that the annular seal protrusion is formed of PFA.

In the above configuration, the amount of displacement of the annular seal portion in the radial direction is suppressed when the drive portion presses the annular seal portion of the valve body against the valve seat and then further presses the annular seal portion against the valve seat. . The amount of displacement is suppressed to, for example, 6.175 μm or less, or 12.4 × 10 ⁻⁴ times or less of the diameter of the annular seal portion when not in contact with the valve seat. Further, for example, when the annular seal portion is flat, the amount of displacement is suppressed to 6.18 × 10 ⁻² times or less of the width dimension of the annular seal portion when the annular seal portion is not in contact with the valve seat. The As described above, when the amount of displacement of the annular seal portion is suppressed, the annular seal portion is rubbed against the valve seat and is less likely to be worn, so that generation of particles that affect semiconductor manufacturing can be reduced. In addition, by suppressing wear due to deformation of the valve body, the sealing performance does not deteriorate even if the valve opening / closing operation is repeated. This improves the durability of the fluid control valve. Further, the required sealing force can be reduced and the drive unit can be made compact.

  In the above configuration, since the diameter of the end face on the valve seat side is 1.3 times or more than the diameter of the annular seal portion when not in contact with the valve seat, the rigidity near the end face on the valve seat side is high. As a result, the valve body is unlikely to deform its end face on the valve seat side during the pressing operation of pressing the annular seal portion against the valve seat. Therefore, the annular seal protrusion is not easily deformed so as to displace the annular seal portion in the radial direction during the pressing operation, and wear of the annular seal portion can be suppressed. Therefore, according to the said structure, generation | occurrence | production of a particle can be reduced by suppressing the abrasion by the deformation | transformation of the valve body which generate | occur | produces at the time of valve closing.

  In the above configuration, since the diameter of the thinnest part of the valve body is smaller than the diameter of the annular seal portion, the end face on the valve seat side is pushed inside the annular seal protrusion toward the valve seat. However, in the fluid control valve, since the amount of displacement of the annular seal surface in the radial direction is suppressed, the wear of the annular seal surface can be reduced and the generation of particles can be reduced.

  In the above configuration, the valve body has a wall thickness in the axial direction at the radial center position of the annular seal portion that is 0.7 times or more the diameter of the annular seal portion. Begins to disperse at a position away from the end face on the valve seat side. For this reason, deformation in the vertical direction is likely to occur near the end face on the valve seat side. Therefore, in the said structure, it is easy to press an annular seal part perpendicularly | vertically to a valve seat, and the displacement amount which an annular seal part displaces to radial direction can be suppressed.

  In the above configuration, since the valve body has a convex portion protruding in the valve seat direction from the valve seat side end surface inside the annular seal projection, the rigidity of the portion that receives a load from the drive unit is high, and the valve seat side end surface is an annular seal. It is difficult to deform so that the inside of the protrusion protrudes toward the valve seat. Therefore, according to the above configuration, the annular seal protrusion is not easily bent due to the deformation of the end face on the valve seat side, and the amount of displacement of the annular seal surface can be suppressed.

  In the above configuration, since the diameter of the base end connected to the valve seat side end surface is equal to or larger than the diameter of the thinnest part of the valve body, the convex part supports the entire load received from the drive part, and Hard to deform. Therefore, according to the said structure, a deformation | transformation of the valve seat side end surface can be suppressed and the displacement amount of an annular seal surface can be reduced.

  In the above configuration, since the annular seal protrusion is formed of high hardness PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), the annular seal protrusion is prevented from being deformed when the valve is closed, and the annular seal is formed. The wear of the part can be suppressed and the generation of particles can be reduced.

  According to the above configuration, it is possible to provide a fluid control valve and a fluid control method that can suppress wear due to deformation of the valve body that occurs when the valve is closed, and reduce the generation of particles.

It is sectional drawing of the fluid control valve which concerns on 1st Embodiment of this invention, Comprising: A closed state is shown. It is sectional drawing of the valve body shown in FIG. It is a table | surface which shows the setting conditions of Comparative Examples 1-3 and Examples 1-13. It is sectional drawing which shows the valve body of Example 10. FIG. It is sectional drawing which shows the valve body of Example 1. FIG. It is sectional drawing which shows the valve body of Example 2. FIG. It is a figure which shows the displacement amount analysis result of the comparative example 1. It is a figure which shows the displacement amount analysis result of the comparative example 2. It is a figure which shows the displacement amount analysis result of the comparative example 3. It is a figure which shows the displacement amount analysis result of Example 1. FIG. It is a figure which shows the displacement amount analysis result of Example 2. FIG. It is a figure which shows the displacement amount analysis result of Example 3. FIG. It is a figure which shows the displacement amount analysis result of Example 4. FIG. It is a figure which shows the displacement amount analysis result of Example 5. FIG. It is a figure which shows the displacement amount analysis result of Example 6. FIG. It is a figure which shows the displacement amount analysis result of Example 7. FIG. It is a figure which shows the displacement amount analysis result of Example 8. FIG. It is a figure which shows the displacement amount analysis result of Example 9. FIG. It is a figure which shows the displacement amount analysis result of Example 10. FIG. It is a figure which shows the displacement amount analysis result of Example 11. FIG. It is a figure which shows the displacement amount analysis result of Example 12. FIG. It is a figure which shows the displacement amount analysis result of Example 13. The ring of Comparative Examples 1-3 and Examples 1-13 when the amount of displacement of the annular seal surface in Comparative Examples 1-3 and Examples 1-13 and the amount of displacement of the annular seal surface of Example 10 are 100% It is a table | surface which shows the ratio of the displacement amount of a seal surface, the ratio of the displacement amount of the annular seal surface with respect to the width direction center diameter, and the ratio of the displacement amount of the annular seal surface with respect to a width dimension. It is a figure which shows the particle measurement value, Comprising: The number of particles of 20 nm or more is shown on a vertical axis | shaft, and the displacement amount (micrometer) of an annular seal surface is shown on a horizontal axis. It is a graph which shows the relationship between the ratio (D / A) of the end surface diameter with respect to the width direction center diameter, and the displacement amount of an annular seal surface, The displacement amount (micrometer) of an annular seal surface is shown on a vertical axis | shaft, and a horizontal axis | shaft is shown. D / A (times) is shown. It is the microscope picture which image | photographed the annular seal surface after a particle test regarding the valve body of Example 10 shown in FIG. It is an image figure of the microscope picture shown in FIG. It is the microscope picture which image | photographed the annular seal surface after a particle test regarding the valve body of Example 1 shown in FIG. It is an image figure of the microscope picture shown in FIG. It is an image figure of the elastic deformation of a diaphragm valve body. It is sectional drawing of the valve body used for the fluid control valve which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the valve body of a 1st modification. It is sectional drawing which shows the valve body of a 2nd modification. It is sectional drawing which shows the valve body of a 3rd modification. It is sectional drawing which shows the valve body of a 4th modification. It is sectional drawing which shows the valve body of a 5th modification.

  Embodiments of a fluid control valve and a fluid control method according to the present invention will be described below with reference to the drawings.

A. First Embodiment (About the outline of the present invention)
FIG. 1 is a cross-sectional view of a fluid control valve 1 according to a first embodiment of the present invention, showing a closed state. The fluid control valve 1 according to the first embodiment is characterized by reducing wear caused by deformation of a diaphragm valve element (an example of a valve element) 4 that occurs when the valve is closed.

  Conventionally, a diaphragm valve has a structure in which the valve body is vertically contacted with the valve seat, or the surface roughness of the valve body annular seal surface or the valve seat surface is increased. Particle countermeasures have been taken by improving the state of contact with the valve seat surface of the seat and suppressing the contact force. However, this method alone cannot sufficiently reduce the number of particles. For example, semiconductor devices are miniaturized every year, and particles that affect semiconductor manufacturing are getting smaller year by year. For example, a fluid control valve is required to reduce as much as possible 20 nm particles that can be measured with a commercially available particle counter. Therefore, in the conventional countermeasures for reducing the number of particles, if the problem particles become smaller, further countermeasures are required, which has been accompanied by finer particles. Therefore, the inventor noticed the necessity of eliminating the cause of particle generation, and discovered the fundamental cause of particle generation through repeated experiments and simulations (see the effect confirmation test result described later).

  FIG. 30 is an image diagram of elastic deformation of the diaphragm valve body 1000. The diaphragm valve body 1000 is formed with a neck portion 1000b by narrowing a portion to which the thin film portion 1000a is connected. As a result, the fluid control valve can adjust the pressure receiving area from the fluid by expanding the volume of the diaphragm chamber accommodating the diaphragm valve body 1000 and expanding the flexible region of the thin film portion 1000a even with the same valve size. The diaphragm valve body 1000 is provided larger than the diameter of the neck portion 1000b so that the valve body portion 1000d including the valve seat side end surface 1000c is coaxial with the neck portion 1000b. The valve seat side end surface 1000c is provided with an annular seal protrusion 1000f on the outer diameter side than the neck portion 1000b, and increases the inner diameter (orifice diameter) of the valve seat opening to increase the control flow rate. In the fluid control valve including the diaphragm valve body 1000, the driving force applied to the neck portion 1000b is transmitted to the annular seal surface 1000e of the annular seal protrusion 1000f via the valve body portion 1000d, and the annular seal surface 1000e is 3 to 50 MPa. Seal the valve seat with surface pressure. In such a diaphragm valve body 1000, the action point K2 at which the annular seal surface 1000e abuts against the valve seat and seals is shifted outward from the force point at which the driving force in the K1 direction in the drawing is applied. Therefore, every time the valve is closed, as shown by K3 in the figure, a force for spreading outward in the radial direction is generated on the annular seal surface 1000e. In this case, as indicated by an imaginary line M in the figure, the diaphragm valve body 1000 is deformed so as to slide the annular seal surface 1000e against the valve seat, and the annular seal surface 1000e is rubbed against the valve seat and worn. . The inventors considered that the worn portion was torn off from the annular seal surface 1000e during the valve opening / closing operation and became particles. The inventors have confirmed this through simulations and experiments. The inventors have devised a shape in the vicinity of the annular seal protrusion so as to suppress or prevent deformation of the valve body.

(Schematic configuration of fluid control valve)
As shown in FIG. 1, the fluid control valve 1 includes a valve unit 2 that controls fluid and a drive unit 3 that applies a driving force to the valve unit 2. The fluid control valve 1 is attached to, for example, a semiconductor manufacturing apparatus and controls the flow rate of the chemical solution supplied to the wafer. In this case, since the fluid control valve 1 may control a highly corrosive chemical solution, the diaphragm valve body 4 partitions the drive unit 3 and the valve unit 2.

  In the drive unit 3, a cylinder body 33 is configured by a cylinder body 31 and a cylinder cover 32. The piston 35 is slidably loaded into a piston chamber 34 in which a piston body 35a is formed in the cylinder body 33, and the piston chamber 34 is partitioned into a first chamber 34a and a second chamber 34b in an airtight manner. The piston body 35a is integrally provided with a shaft 35b. A lower end portion of the shaft 35 b protrudes from the cylinder body 33 toward the valve portion 2 and is connected to the diaphragm valve body 4 of the valve portion 2. The compression spring 36 applies a sealing load to the diaphragm valve body 4, is contracted in the first chamber 34 a, and constantly urges the piston 35 toward the valve seat 24 side of the valve portion 2. The cylinder body 33 is formed with an intake / exhaust port 33a that communicates with the first chamber 34a to intake and exhaust, and an operation port 33b that communicates with the second chamber 34b and supplies operation air.

  The drive unit 3 causes the piston 35 to reciprocate linearly along the axis by the balance between the spring force of the compression spring 36 and the internal pressure of the second chamber 34b, and moves the diaphragm valve body 4 by a predetermined stroke. Except for the compression spring 36 and the annular seal member, the drive unit 3 is made of a fluororesin material and can be used in a highly corrosive atmosphere.

  The valve portion 2 is built in the valve body 21 and performs fluid control by the annular seal protrusion 414 of the diaphragm valve body 4 contacting or separating from the valve seat surface 24 a of the valve seat 24. The valve body 21 and the diaphragm valve body 4 are made of a fluororesin in order to ensure corrosion resistance. Further, the diaphragm valve body 4 is made of a fluororesin that is equal in hardness to the valve body 21 (valve seat 24) or lower in hardness than the valve body 21 (valve seat 24) in order to enhance the sealing performance of the annular seal protrusion 414. Is preferred. In this embodiment, the material of the valve body 21 (valve seat 24) is PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) hardness D60 to 64, and the material of the diaphragm valve body 4 is PTFE (polytetrafluoroethylene). The hardness is D53 to 58.

  The valve body 21 has a rectangular parallelepiped shape, and is opened on a side surface where the first port 21a and the second port 21b for inputting and outputting fluids are opposed to each other. An opening 21e is formed in a cylindrical shape on the upper surface of the valve body 21, and a mounting hole 21f is formed in an annular shape outside the opening 21e. The valve portion 2 is fitted with the outer edge portion 43 of the diaphragm valve body 4 in the mounting hole 21f of the valve body 21 and sandwiches the outer edge portion 43 between the valve body 21 and the cylinder body 33, so that the diaphragm chamber 22 and the non-diaphragm chamber 22 are not in contact with each other. A liquid contact chamber 23 is formed. The valve body 41 of the diaphragm valve body 4 is connected to the shaft 35b and moves in the diaphragm chamber 22 in the vertical direction in the figure. The non-wetted chamber 23 communicates with a breathing hole 33 c formed in the cylinder body 33 so that the thin film portion 42 can be smoothly deformed as the valve body 41 moves.

  The first communication channel 21 c is formed in an L shape in the valve body 21 so as to allow the first port 21 a and the diaphragm chamber 22 to communicate with each other, and is open at the center of the bottom surface of the diaphragm chamber 22. A valve seat 24 is provided on the bottom surface of the diaphragm chamber 22 along the outer periphery of the opening where the first communication channel 21c opens. The valve seat 24 includes a valve seat surface 24 a that is processed so as to be a flat surface orthogonal to the axis of the diaphragm chamber 22. The second communication channel 21 d is formed in an L shape so that the second port 21 b communicates with the diaphragm chamber 22, and is open to the outside of the valve seat 24.

(Valve structure)
FIG. 2 is a sectional view of the diaphragm valve body 4 shown in FIG. In the diaphragm valve body 4, a columnar valve body 41 is connected to the drive unit 3 (see FIG. 1), and contacts or separates from the valve seat 24. A thin film portion 42 is connected to the outer peripheral surface of the valve main body 41, and an outer edge portion 43 is provided thick on the outer edge portion of the thin film portion 42. The valve body 41 is provided with a cylindrical portion 411, a shoulder portion 412 and a neck portion 413 on the same axis. In the present embodiment, the valve body portion 410 is configured by a columnar portion 411 and a shoulder portion 412.

  The cylindrical portion 411 has a cylindrical shape and includes a valve seat side end surface 411 a that faces the valve seat 24. The neck portion 413 is connected to the outer peripheral surface 413 a of the thin film portion 42, and has a diameter smaller than that of the columnar portion 411 in order to secure the volume of the diaphragm chamber 22 (see FIG. 1). The neck portion 413 is provided with a male screw portion 413b which is screwed into a female screw portion 35c (see FIG. 1) provided in the shaft 35b. The shoulder portion 412 is interposed between the columnar portion 411 and the neck portion 413 and is provided so as to reduce in diameter toward the neck portion 413 from the columnar portion 411, so that the fluid flowing through the diaphragm chamber 22 (see FIG. 1) is retained. It prevents the generation of turbulent flow. In addition, since the outer diameter of the outer edge 43 can be reduced by reducing the diameter of the neck 413, the valve body 21 can be made compact.

  On the valve seat side end surface 411 a of the valve body 41, an annular seal protrusion 414 is provided in an annular shape centering on the axis of the valve body 41. The annular seal protrusion 414 is provided outside a connection position T (hereinafter also referred to as “T portion”) where the outer peripheral surface 413 a of the neck portion 413 is connected to the outer peripheral surface 412 a of the shoulder portion 412. Therefore, the valve body 41 is sealed to the valve seat 24 at a position outside the position where the seal load is applied, and the area (orifice diameter) of the valve seat opening is increased.

  The height C of the annular seal protrusion 414 from the valve seat side end surface 411a to the tip of the annular seal protrusion 414 is set so that the annular seal protrusion 414 has rigidity that does not easily fall even when a seal load is applied. In the present embodiment, the height C of the annular seal protrusion 414 is set to the diameter (“diameter of the annular seal portion”) in the radial center position of the annular seal surface 414a (an example of the annular seal portion) when not contacting the valve seat. (Hereinafter also referred to as “width-direction center diameter A”) is set to 1/10.

  The annular seal protrusion 414 is provided so as to reduce in diameter from the valve seat side end surface 411a side toward the tip end portion (valve seat side). That is, the inner peripheral surface 414b and the outer peripheral surface 414c of the annular seal protrusion 414 are provided with a taper that increases the inclination from the valve seat side end surface 411a toward the tip. The annular seal protrusion 414 is processed into a flat shape so that the tip thereof is orthogonal to the axis of the valve body 41 to form an annular seal surface 414a. As a result, the annular seal protrusion 414 has a high seal load per unit area on the annular seal surface 414a, prevents fluid leakage, and the annular seal surface 414a is less likely to slip relative to the valve seat surface 24a. Moreover, the drive part 3 becomes compact. The radial width B (hereinafter also referred to as “width B”) of the annular seal surface 414a is set to be 1/100 or more and 1/10 or less of the center A of the annular seal surface 414a in the width direction. It is desirable.

  The diaphragm valve body 4 is configured such that the amount of displacement of the annular seal surface 414a in the radial direction is set to 6.175 μm or less, and the annular seal surface 414a is rubbed against the valve seat 24 and is not easily worn. In order to provide this rigidity, the diaphragm valve body 4 has a cylindrical portion 411 (valve seat side end surface 411a) having a large diameter D (hereinafter also referred to as “end surface diameter D”) and a convex portion 416 having an annular seal protrusion. 414 is provided inside.

  In addition, the end face diameter D is set to 1.3 times or more of the center A in the width direction, and the diameter expansion width dimension E from the annular seal protrusion 414 to the outer peripheral face 411b of the cylindrical portion 411 is increased. Accordingly, the valve body 41 can easily press the annular seal protrusion 414 perpendicularly to the valve seat surface 24a along the direction in which the drive unit 3 applies a load to the diaphragm valve body 4, and the displacement amount of the annular seal surface 414a can be reduced. Can be suppressed.

  Further, the valve body 41 is set such that the axial thickness F at the radial center position of the annular seal surface 414a is 0.7 times or more the width direction central diameter A. As a result, the valve body 41 has a rigidity that suppresses deformation generated from the annular seal surface 414a to the upper side when the seal load is applied to seal the annular seal protrusion 414 to the valve seat 24. Further, the valve main body 41 can widely disperse the load of the driving unit 3 in the valve body 410. In the valve body 41, the wall thickness F may be set to 0.7 times or less of the center A in the width direction as long as the displacement amount of the annular seal surface 414a can be 6.175 μm or less. In this case, the volume of the diaphragm chamber 22 can be expanded to prevent the fluid from staying, and the valve size can be reduced.

  The convex portion 416 is formed on the inner side of the annular seal projection 414 on the valve seat side end surface 411a so as to be coaxial with the neck portion 413, and reinforces the valve seat side end surface 411a from the valve seat side. The valve main body 41 has a pressure receiving surface in which the diameter H (hereinafter also referred to as “base end diameter H”) of the base end portion where the convex portion 416 is connected to the valve main body 41 (cylindrical portion 411) receives a load from the driving portion. The convex portion 416 is provided so as to be equal to or greater than the diameter J (hereinafter referred to as “detail diameter J”) of the narrowest portion between the valve seat side end surface. In other words, the convex portion 416 is provided so that the outer peripheral position U (hereinafter also referred to as “U portion”) of the base end portion is located directly below the detail diameter J or outside the detail diameter J in the radial direction. As a result, the valve body 41 is thickened at the portion to which the seal load is applied by the convex portion 416, and the rigidity is increased. Further, the height I of the base end portion connected to the valve body 41 of the convex portion 416 is the height of the annular seal protrusion 414 (the height from the valve seat side end surface 411a to the annular seal surface 414a of the annular seal protrusion 414). C is 0.7 times or more. As a result, the valve main body 41 is thickened at the center and increased in rigidity.

  In the valve main body 41, an annular groove 415 is formed between the annular seal protrusion 414 and the convex portion 416 so that the elastic deformation generated in the convex portion 416 is not easily transmitted to the annular seal protrusion 414.

(Fluid control method using fluid control valve)
Next, a fluid control method using the fluid control valve 1 having the above configuration will be described. For example, the fluid control valve 1 has a first port 21a connected to a chemical supply source and a second port 21b connected to a reaction chamber of a semiconductor manufacturing apparatus.

(General operation of fluid control valve)
When the fluid control valve 1 is in a standby state in which no chemical is supplied to the wafer, the operation fluid is not supplied to the operation port 33b. In this case, the urging force of the compression spring 36 acts on the diaphragm valve body 4 via the piston 35, and the annular seal protrusion 414 of the diaphragm valve body 4 is in close contact with the valve seat surface 24 a of the valve seat 24 and sealed. At this time, the valve unit 2 blocks between the first port 21a and the second port 21b, and does not supply the chemical solution from the second port 21b to the reaction chamber.

  When supplying a chemical to the wafer, the fluid control valve 1 is supplied with an operation fluid to the operation port 33b. When the internal pressure of the second chamber 34 b becomes larger than the urging force of the compression spring 36, the piston 35 moves to the counter valve seat side against the compression spring 36. The diaphragm valve body 4 ascends integrally with the piston 35 and separates the annular seal protrusion 414 from the valve seat surface 24a. As a result, the fluid control valve 1 causes the chemical solution to flow from the first port 21a to the second port 21b in accordance with the stroke of the valve body 41 and to supply the reaction chamber.

  When stopping the supply of the chemical solution to the wafer, the fluid control valve 1 exhausts the operation fluid from the operation port 33b. Then, the piston 35 is urged by the compression spring 36 and moves in the valve seat direction, and presses the neck portion 413 of the diaphragm valve body 4 in the valve seat direction. The diaphragm valve body 4 descends integrally with the piston 35, contacts the annular seal surface 414a of the annular seal protrusion 414 with the valve seat surface 24a, and then applies a seal load to the annular seal protrusion 414 to apply the annular seal surface 414a. Is pressed against the valve seat surface 24a. As a result, the fluid control valve 1 enters a standby state.

(Wear due to deformation of the valve body that occurs when the valve is closed and how to reduce it)
In the fluid control valve 1, the diaphragm valve body 4 has a detail diameter J smaller than the center diameter A in the width direction of the annular seal surface 414a. Therefore, in the diaphragm valve body 4, the point of action for sealing the annular seal surface 414 a against the valve seat surface 24 a is shifted to the outside of the force point of the portion that transmits the driving force of the driving unit 3 to the valve seat side end surface 411 a. . When the diaphragm valve body 4 is in the valve closing operation, the annular seal surface 414a of the annular seal projection 414 is brought into contact with the valve seat surface 24a, and further, a seal load is applied to the annular seal projection 414 by the drive unit 3 to form an annular shape. The sealing surface 414a is pressed against the valve seat surface 24a. In this case, the diaphragm valve body 4 tends to elastically deform the central portion of the valve main body 41 not supported by the valve seat 24 toward the valve seat. The greater the amount of elastic deformation, the more the diaphragm valve body 4 is elastically deformed so as to greatly displace the annular seal surface 414a toward the radially outer side. If the elastic deformation of the annular seal protrusion 414 is large, the amount of the annular seal surface 414a rubbed against the valve seat surface 24a increases and wears easily. The wear of the annular seal surface 414a becomes particles.

  However, in this embodiment, in order to reduce the wear of the annular seal surface 414a that occurs when the valve is closed, the diaphragm valve body 4 itself has a shape that can suppress the amount of displacement of the annular seal surface 414a in the radially outward direction. Therefore, the generation of particles itself is suppressed or prevented. Therefore, even if the particles that affect the semiconductor manufacturing become smaller as the semiconductor device is miniaturized, the generation of particles can be suppressed or prevented so as to cope with it.

(Specific description of a method for reducing the wear of the annular seal surface that occurs when the valve is closed)
In the fluid control valve 1, the annular seal surface 414a is brought into contact with the valve seat surface 24a, and then the annular seal surface 414a is pressed against the valve seat surface 24a to be sealed with a predetermined seal load. The amount of displacement of the surface 414a in the radially outward direction with respect to the valve seat 24 is suppressed. Specifically, the amount of displacement is 6.175 μm or less (12.4 × 10 ⁻⁴ times or less of the center A in the width direction, or 6.18 × 10 ⁻² times or less of the width dimension B). It is suppressed. As described above, when the amount of displacement of the annular seal surface 414a is suppressed, the annular seal surface 414a is hardly rubbed and worn by the valve seat surface 24a, so that generation of particles affecting semiconductor manufacturing can be reduced. In addition, by suppressing wear due to deformation of the valve body 41, the sealing performance does not deteriorate even if the valve opening / closing operation is repeated. Thereby, the durability of the fluid control valve 1 is improved. Further, the fluid control valve 1 can reduce the required sealing force and make the drive unit 3 compact. The diaphragm valve body 4 has a shape necessary to realize these.

  Since the diaphragm valve body 4 has an end face diameter D that is 1.3 times or more of the center A in the width direction, the rigidity in the vicinity of the valve seat side end face 411a is increased. Therefore, in the diaphragm valve body 4, during the pressing operation, deformation of the valve seat side end surface 411a is suppressed, and the annular seal protrusion 414 is hardly pulled by the valve seat side end surface 411a. Accordingly, the diaphragm valve body 4 is less likely to be deformed so that the annular seal protrusion 414 is displaced from the valve seat surface 24a during the pressing operation, and wear of the annular seal surface 414a is reduced. Therefore, the fluid control valve 1 can reduce wear of the annular seal surface 414a due to deformation of the diaphragm valve body 4 (valve body 41) that occurs when the valve is closed, and can suppress or prevent generation of particles.

  Further, since the diaphragm valve body 4 has a diameter of the narrowest portion in the valve main body 41, that is, a detailed diameter J, smaller than the central diameter A in the width direction, the valve seat side end surface 411a is located on the inner side of the annular seal protrusion 414 on the valve seat. It is pushed to the 24 side. However, in the fluid control valve 1, since the amount of displacement of the annular seal surface 414a in the radial direction is suppressed, wear of the annular seal surface 414a can be reduced and generation of particles can be reduced.

  The diaphragm valve body 4 receives a load from the drive unit 3 because the axial thickness F at the radial center position of the annular seal surface 414a is 0.7 times or more the width direction central diameter A. The deformation that occurs is started to be dispersed at a position away from the valve seat side end surface 411a. Therefore, deformation in the vertical direction is likely to occur near the valve seat side end surface 411a. Therefore, according to the fluid control valve 1 of the present embodiment, the annular seal surface 414a can be easily pressed perpendicularly to the valve seat surface 24a, and the amount of displacement of the annular seal surface 414a in the radial direction can be suppressed.

  Further, the diaphragm valve body 4 has the convex portion 416 protruding from the valve seat side end surface 411a to the valve seat 24 side on the inner side of the annular seal protrusion 414, and therefore the rigidity of the portion receiving the load from the drive unit 3 is high. The side end surface 411a is not easily deformed so that the inner portion of the annular seal protrusion 414 protrudes toward the valve seat 24 side. Therefore, in the fluid control valve 1, the annular seal protrusion 414 is not easily bent due to the deformation of the valve seat side end surface 411a, and the displacement amount of the annular seal surface 414a can be suppressed.

  In particular, since the convex portion 416 has a base end portion diameter H equal to or greater than the detailed diameter J, the convex portion 416 supports the entire load received from the drive unit 3 and hardly deforms the valve body 41 in the radially outward direction. Therefore, the fluid control valve 1 can suppress the deformation of the valve seat side end surface 411a and reduce the displacement amount of the annular seal surface 414a.

  Further, the convex portion 416 has a height I from the base end portion to the distal end surface 416a that is 0.7 times or more than the height C from the valve seat side end surface 411a to the annular seal surface 414a. A groove 415 is formed deeply. Thereby, the deformation is hardly transmitted from the convex portion 416 to the annular seal protrusion 414. Therefore, during the pressing operation, the annular seal surface 414a is unlikely to be displaced with respect to the valve seat surface 24a, and is not easily worn. Therefore, the fluid control valve 1 can reduce wear caused by deformation of the diaphragm valve body 4 that occurs when the valve is closed.

  As described above, the fluid control valve 1 and the fluid control method can reduce wear caused by deformation of the diaphragm valve body 4 that occurs when the valve is closed. Since the fluid control valve 1 reduces slight wear caused by the deformation of the diaphragm valve body 4 that occurs when the valve is closed, the generation of fine particles can be suppressed or prevented.

(Effectiveness confirmation test)
The inventors made (a) the effect given by the end face diameter D, (b) the effect given by the thickness F, (c) the effect given by the convex part, and (d) the annular concave groove with respect to the displacement amount of the annular seal surface (E) the effect given by the base end diameter H, (f) the effect given by the convex height I, (g) the effect given by the combination of the end face diameter D and the wall thickness F, and (h) the convex A test was conducted to examine the effect of the combination with the end face diameter D, and (i) the effect of the combination of the convex portion, the thickness F, and the height G.

  For the effect confirmation test, Comparative Examples 1 to 3 and Examples 1 to 13 having different shapes as shown in FIG. 3 were used. FIG. 3 is a table showing the setting conditions of Comparative Examples 1 to 3 and Examples 1 to 13 used in the effect confirmation test. 4 to 6 are sectional views showing the valve body 104 of the tenth embodiment, the valve body 204 of the first embodiment, and the valve body 304 of the second embodiment. In addition, Example 4 is corresponded to the said diaphragm valve body 4 (refer FIG. 2). In the following description and the drawings to be cited, among the configurations of Comparative Examples 1 to 3 and Examples 1 to 3 and 5 to 13, the configurations common to the diaphragm valve body 4 of Example 4 are denoted by the same reference numerals as in FIG. The description is omitted as appropriate. In the following description, “diaphragm valve element 4” is also referred to as “valve element 4”.

In the effect confirmation test, analysis software made by Dassault Systemes Solid Works Corp. was used. In the test, for Comparative Examples 1 to 3 and Examples 1 to 13, the pressure until the annular seal surface 414a is pressed against the valve seat surface 24a with a seal load of 50 N after the annular seal surface 414a starts to contact the valve seat 24. During operation, the valve body 841, 1441, 1541, 241, 341, 441, 41, 541, 641, 1043, 1141, 741, 141, 1242, 1342 set to a physical property elastic modulus of 500 MPa and a density of 2200 kg / m ³ . The amount of displacement generated by 943 was analyzed. The analysis results are shown in FIGS. FIG. 23 shows Comparative Examples 1 to 3 and the implementation when the displacement amount of the annular seal surface 414a in Comparative Examples 1 to 3 and Examples 1 to 13 and the displacement amount of the annular seal surface 414a of Example 10 is 100%. The table | surface which shows the ratio of the displacement amount of the annular seal surface 414a of Examples 1-13, the ratio of the displacement amount of the annular seal surface 414a with respect to the width direction center diameter A, and the ratio of the displacement amount of the annular seal surface 414a with respect to the width dimension B. It is.

<(A) Effect of end surface diameter D on the amount of displacement of the annular seal surface>
As shown in FIG. 3, Comparative Examples 1 and 2 and Examples 7 and 10 that differ only in the end face diameter D are compared. As shown in FIGS. 3 and 4, in Example 10, the center diameter A in the width direction of the annular seal surface 414 a is 5.0 mm, the width dimension B of the annular seal surface 414 a is 0.1 mm, and the height of the annular seal protrusion 414 is. C was set to 0.5 mm. In Example 10, the end face diameter D was set to 6.5 mm which is 1.30 times the width direction central diameter A. In Example 10, the diameter expansion width dimension E from the connection position S (hereinafter also referred to as “S part”) where the outer peripheral surface 414 c of the annular seal protrusion 414 is connected to the valve seat side end surface 411 a to the outer peripheral surface 411 b of the columnar part 1411. Was set to 0.25 mm. In Example 10, the axial thickness F at the center position in the radial direction of the annular seal surface 414a was set to 3.7 mm. In Example 10, the height G from the annular seal surface 414a to the upper end position V of the cylindrical portion 1411 was set to 2.65 mm. Furthermore, in Example 10, the detail diameter J was set to 4 mm. In addition, the comparative example 1 is not provided with a convex part or an annular groove.

  On the other hand, as shown in FIG. 3, Comparative Examples 1 and 2 and Example 7 are configured in the same manner as Example 10 except for the end face diameter D and the expanded width dimension E. The end face diameter D of Comparative Example 1 is 6.0 mm, which is 1.2 times the width direction central diameter A. The diameter expansion width dimension E of Comparative Example 1 is 0 mm. The end face diameter D of Comparative Example 2 is 6.25 mm, which is 1.25 times the center A in the width direction. The expanded width dimension E of Comparative Example 2 is 0.125 mm. The end face diameter D of Example 7 is 7.5 mm, which is 1.5 times the width direction central diameter A. The expanded width dimension E of Example 7 is 0.75 mm.

  In FIG. 7, the displacement amount analysis result of the comparative example 1 is shown. As indicated by X86 and X88 in the figure, in the valve main body 841 of Comparative Example 1, the displacement amount of the cylindrical portion 843 is large from the central portion toward the radially outer side. The cylindrical portion 843 is larger as the change rate of the displacement amount is closer to the outer peripheral surface 411b. The cylindrical portion 843 increases as the displacement amount of the upper portion of the annular seal protrusion 414 in the drawing approaches the annular seal protrusion 414. Therefore, as shown by Y11 in the figure, the comparative example 1 is deformed so that the cylindrical portion 843 is crushed by the load of the driving portion 3 during the pressing operation and the valve seat side end surface 843a side is expanded radially outward. I understand that. In Comparative Example 1, as indicated by X85 and X86 in the figure, the difference between the displacement amount at the center portion of the valve seat side end surface 843a and the displacement amount at the outer edge portion is large. Therefore, the valve seat side end face 843a of Comparative Example 1 is curved and deformed so that the center part protrudes convexly toward the valve seat side and the outer edge part rises toward the counter valve seat side, as indicated by Y12 in the figure. Then, it can be seen that the annular seal protrusion 414 is pressed against the valve seat surface 24a so as to be pushed outward in the radial direction.

And as shown to X81-X85 of FIG. 7, the comparative example 1 has the displacement amount of Q part of the annular seal protrusion 414, R part, and S part larger than the displacement amount of P part. Therefore, it can be seen that in the comparative example 1, the annular seal protrusion 414 is bent and deformed so as to expand the distal end portion in the radially outward direction during the pressing operation. As shown in FIG. 23, in Comparative Example 1, the displacement amount of the annular seal surface 414a is 9.428 μm. The amount of displacement is 18.90 × 10 ⁻⁴ times the width direction center diameter A or 9.43 × 10 ⁻² times the width dimension B of the annular seal surface 414a.

In FIG. 8, the displacement amount analysis result of the comparative example 2 is shown. In the valve main body 1441 of Comparative Example 2, as shown by X146 and X148 in the figure, the displacement amount of the cylindrical portion 1442 is large from the central portion toward the radially outer side. The rate of change of the displacement is smaller than that of Comparative Example 1. This is presumably because Comparative Example 2 has a larger diameter expansion width dimension E and higher rigidity than Comparative Example 1, so that the deformation of the central portion is not easily transmitted in the radially outward direction. However, in Comparative Example 2, as indicated by X146 and X145 in the figure, the difference in displacement amount between the center portion of the valve seat side end surface 1442a and the outer edge portion is large as in Comparative Example 1. Therefore, it can be seen that in Comparative Example 2, the valve seat side end surface 1442a is greatly deformed in the same manner as in Comparative Example 1. Further, as shown by X141 to X144 in the figure, in Comparative Example 2, the displacement amount of the Q part, the R part, and the S part is larger than that of the P part, and like the comparative example 1, the annular seal protrusion 414 is outside the tip part. It turns out that it bends and deforms so as to widen in the direction. As shown in FIG. 23, in Comparative Example 2, the displacement amount of the annular seal surface 414a is 7.233 μm. The amount of displacement is 14.47 × 10 ⁻⁴ times the width direction center diameter A and 7.23 × 10 ⁻² times the width dimension B of the annular seal surface 414a.

  In FIG. 19, the displacement amount analysis result of Example 10 is shown. In the valve main body 141 of the tenth embodiment, as indicated by X17 and X18 in the figure, the amount of displacement increases from the center of the cylindrical portion 1411 toward the radially outer side. The change rate of the displacement amount is suppressed as in Comparative Example 2. And as for Example 10, as shown to X15-X18 in a figure, the difference of the displacement amount of the center part of the valve seat side end surface 1411a and an outer edge part is smaller than the comparative example 2. FIG. Therefore, in Example 10, it can be seen that the deformation of the valve seat side end surface 1411a is suppressed and the annular seal protrusion 414 is easily pressed against the valve seat surface 24a as compared with Comparative Example 2.

Further, as shown by X11 to X14 in FIG. 19, the displacement amount of the P part, the Q part, and the S part is smaller in the tenth embodiment than in the first and second comparative examples. Therefore, it can be seen that in Example 10, compared to Comparative Examples 1 and 2, the annular seal protrusion 414 is less likely to be deflected radially outward, and displacement on the inner peripheral side of the annular seal surface 414a can be suppressed. As shown in FIG. 23, in Example 10, the displacement amount of the annular seal surface 414a is 6.175 μm. The amount of displacement is 12.40 × 10 ⁻⁴ times the width direction center diameter A or 6.18 × 10 ⁻² times the width dimension B of the annular seal surface 414a.

In FIG. 16, the displacement amount analysis result of Example 7 is shown. In the valve body 1043 of the seventh embodiment, as indicated by X106 and X108 in the figure, the amount of change increases from the center of the cylindrical portion 411 toward the radially outer side. The rate of change is smaller than Example 10. Moreover, in the cylindrical portion 411, the displacement amount changes substantially concentrically around the axis. Therefore, in Example 7, it can be seen that the cylindrical portion 411 is deformed in the vertical direction during the pressing operation, and the annular seal protrusion 414 is easily pressed vertically to the valve seat surface 24a. In the seventh embodiment, as indicated by X101 to X104 in the figure, the displacement amounts of the P portion, the Q portion, the R portion, and the S portion are smaller than those of the tenth embodiment. Therefore, it can be seen that in Example 7, the annular seal protrusion 414 is less likely to bend so that the distal end portion is expanded in the radially outward direction, and the amount of displacement between the Q portion and the R portion is reduced. As shown in FIG. 23, in Example 7, the displacement amount of the annular seal surface 414a is 4.887 μm. The amount of displacement is 9.77 × 10 ⁻⁴ times the center diameter A in the width direction, or 4.89 × 10 ⁻² times the width dimension B of the annular seal surface 414a.

  FIG. 25 is a graph showing the relationship between the ratio (D / A) of the end surface diameter D to the center diameter A in the width direction and the amount of displacement of the annular seal surface 414a. In Comparative Example 1 in which D / A is 1.2, the displacement amount of the annular seal surface 414a generated during the pressing operation is 9.428 μm. In Comparative Example 2 where D / A is 1.25, the amount of displacement of the annular seal surface 414a that occurs during the pressing operation is 7.233 μm. In Example 10 in which D / A is 1.30, the amount of displacement of the annular seal surface 414a generated during the pressing operation is 6.175 μm. In Example 7 in which D / A is 1.5, the displacement amount of the annular seal surface 414a generated during the pressing operation is 4.887 μm. Accordingly, the rate of decrease in the amount of displacement of the annular seal surface 414a suddenly becomes mild when the end surface diameter D is 1.3 times or more the width direction center diameter A. This is because when the end face diameter D is 1.3 times or more and the expanded diameter dimension E is increased, the wall having a thickness necessary to support the deformation in the radially outward direction generated at the center of the cylindrical portion is an annular seal. It is thought that it is formed outside the protrusion 414 and the rigidity of the valve body is increased. Therefore, the end face diameter D is preferably 1.3 times or more with respect to the center A in the width direction.

  Here, the inventors produced the valve body 104 shown in FIG. 4 based on Example 10, and performed a particle test on the valve body 104. In this particle test, as a pretreatment, an evaluation valve (valve equipped with a valve body 104) is installed in a line through which pure water flows, and evaluation is performed while flowing pure water at 1,000 mL / min for 3 hours with the valve fully open. The valve was flushed. After that, an evaluation valve is installed in the line where pure water flows, a particle counter is installed downstream of the evaluation valve, the seal load of the evaluation valve is set to 50 N, and the evaluation valve is opened and closed 15,000 times over 600 minutes. While operating, pure water of 1,000 mL / min was allowed to flow, and 75 mL / min of pure water that passed through the evaluation valve was passed through the particle counter. With a particle counter, the integrated value of the number of particles of 20 nm or more was measured every 1 minute, and the particle value contained per 1 mL was measured from the integrated value during 15,000 valve opening / closing operations. The particle test result of the evaluation valve equipped with the valve body 104 is shown in FIG.

  As shown in FIG. 24, the valve body 104 measured 17.78 particles per mL during the particle test.

  On the other hand, the inventors also performed a particle test on an unmeasured sample in which the displacement amount of the annular seal surface 414a is 6.175 μm or more and 9 μm or less. Since the test method is the same as described above, the description is omitted. As a result, the number of particles measured during the particle test for the sample was 797.8. From these particle tests, it was found that when the amount of displacement of the annular seal surface 414a exceeds 6.175 μm, the amount of generated particles increases rapidly. Therefore, the valve body can effectively reduce the generation amount of particles by setting the displacement amount of the annular seal surface 414a to 6.175 μm or less.

  The inventors took a photomicrograph of the annular seal surface 414a for the valve element 104 after the particle test. When the magnification of the photomicrograph was set to 500, the valve body 104 was confirmed to have burrs in the Q portion of the annular seal surface 414a and no burrs in the R portion of the annular seal surface 414a. The burr is not generated in the R portion of the annular seal surface 414a because the burr generated in the R portion is caught between the annular seal surface 414a and the valve seat surface 24a when the annular seal surface 414a moves in the radially outward direction. It is thought to be licked.

  Furthermore, the inventors increased the magnification of the micrograph from 500 times to 2000 times, and confirmed the state near the Q portion. It can be seen that the valve element 104 has fine wrinkles as indicated by Z1 in FIGS. 26 and 27 and fine scratches as indicated by Z2 in the drawings. Further, it can be seen that the valve body 104 is generated such that the burr is pulled out from the Q portion of the annular seal surface 414a to the inner peripheral surface 414b side as shown by Z3 in the drawing. As a result, when the valve opening / closing operation is started, the annular seal surface 414a rubs the Q portion against the valve seat to create a small scratch, and the scratch is rolled up while the valve opening / closing operation is repeated to become a burr. These burrs are considered to be separated from the annular seal surface 414a into particles. Therefore, if the annular seal protrusion 414 is prevented from being deformed so as to displace the annular seal surface 414a in the radial direction, the wear of the Q portion is reduced, and particles that can be measured by the particle counter, as well as fine particles that cannot be measured by the particle counter. It is thought that the generation of small particles can be reduced.

<(B) Effect of wall thickness F on the amount of displacement of the annular seal surface>
As shown in FIG. 3, Comparative Example 3, Example 2, and Example 7 which are different only in the thickness F are compared. In Comparative Example 3, the axial thickness F at the center position of the annular seal protrusion 414 is set to 3 mm, which is 0.6 times the center diameter A (5 mm) in the width direction of the annular seal surface 414a. In Example 7, the axial thickness F at the center position of the annular seal projection 414 is set to 3.7 mm, which is 0.74 times the center diameter A (5 mm) in the width direction of the annular seal surface 414a. Yes. In Example 2, the axial thickness F at the center position of the annular seal protrusion 414 is set to 4.5 mm, which is 0.9 times the center diameter A (5 mm) in the width direction of the annular seal surface 414a. Yes. The valve bodies 1541, 341, and 1043 of Comparative Example 3, Example 2, and Example 7 have the same height G, and the thickness F is adjusted by the shoulders 1542, 3411, and 412. .

FIG. 9 shows the displacement amount analysis result of Comparative Example 3. As indicated by X156 and X158 in the figure, in the valve main body 1541 of the comparative example 3, the displacement amount of the valve body portion 1540 is large from the central portion toward the radially outer side. As indicated by X158 in the figure, the valve body 1540 has a larger displacement amount in the upper part of the annular seal protrusion 414 in the figure as it approaches the annular seal protrusion 414. Further, the valve main body 1541 has a large difference in displacement between the center portion of the valve seat side end surface 411a and the outer edge portion. Therefore, it can be seen that in Comparative Example 3, the cylindrical portion 411 is deformed so that the valve seat side end surface 411a side expands radially outward during the pressing operation, and it is difficult to press the annular seal protrusion 414 perpendicularly to the valve seat surface 24a. . And as shown to X151-X154 in a figure, it turns out that the annular seal protrusion 414 has a larger displacement amount on the outer peripheral surface 414c side than the inner peripheral surface 414b side, and bends so that the tip end portion is expanded radially outward. . As shown in FIG. 23, in the comparative example 3, the displacement amount of the annular seal surface 414a is 6.449 μm. The amount of displacement is 12.90 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414 a or 6.45 × 10 ⁻² times the width dimension B.

As indicated by X108 in FIG. 16, in the valve main body 1043 of the seventh embodiment, the amount of displacement of the upper portion of the annular seal protrusion 414 in the figure changes concentrically around the axis. Therefore, in the valve main body 1043, the valve body portion 1042 is easily deformed in the vertical direction, and the annular seal protrusion 414 is easily pressed perpendicularly to the valve seat surface 24a. Further, as shown by X101 to X104 in the figure, in Example 7, the displacement amount of the P part, the Q part, the R part, and the S part is smaller than that of the comparative example 3. Therefore, Example 7 is more difficult to bend than Comparative Example 3. As shown in FIG. 23, in Example 7, the displacement amount of the annular seal surface 414a is 4.887 μm. The amount of displacement is 9.77 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414 a or 4.89 × 10 ⁻² times the width dimension B.

FIG. 11 shows the displacement amount analysis result of the second embodiment. As shown by X36 and X38 in the figure, in the valve main body 341 of the second embodiment, the amount of deformation of the upper portion of the annular seal protrusion 414 in the figure is changed more concentrically around the axis than in the seventh embodiment. Further, as indicated by X31 and X32 in the figure, the second embodiment has a smaller deformation amount of the P portion and the Q portion of the annular seal protrusion 414 than the seventh embodiment. Therefore, compared with Example 7, Example 2 is easy to deform | transform the cylindrical part 411 and the cyclic | annular seal protrusion 414 to a perpendicular direction. As shown in FIG. 23, in Example 2, the displacement amount of the annular seal surface 414a is 4.037 μm. The amount of displacement is 8.07 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414a or 4.04 × 10 ⁻² times the width dimension B.

  Therefore, even if the valve body is increased by the thickness F, the amount of displacement of the annular seal surface 414a can be suppressed. This is presumably because when the thickness of the valve body F is large, the load received from the drive unit 3 is dispersed at a position away from the end face on the valve seat side, and is easily applied in the valve seat direction (vertical direction).

<(C) About the effect which a convex part has with respect to the displacement amount of an annular seal surface>
As shown in FIG. 3, the valve body 204 of Example 1 and the valve body 104 of Example 10 which differ only in the presence or absence of the convex part 416 are compared. The first embodiment is different from the tenth embodiment only in that a convex portion 416 is provided. Since Example 10 has been described above, a description thereof will be omitted. As for the convex part 416 of Example 1, the base end part diameter H is 4 mm. Further, the height I from the front end surface 416a to the valve seat side end surface 1411a of the convex portion 416 is 0.5 mm, which is the same as the height C of the annular seal protrusion 414.

The displacement amount in the vicinity of the P portion to the S portion in the first embodiment shown in X21 to X24 in FIG. 10 is smaller than the displacement amount in the vicinity of the P portion to the S portion in the tenth embodiment shown in X11 to X14 in FIG. It can be seen that the deformation of the annular seal protrusion 414 is smaller than that in Example 10. As shown in FIG. 23, in Example 10, the displacement amount of the annular seal surface 414a is 6.175 μm. The amount of displacement is 6.18 × 10 ⁻² times the width dimension B of the annular sealing surface 414a or 12.40 × 10 ⁻⁴ times the center diameter A in the width direction. On the other hand, in Example 1, the displacement amount of the annular seal surface 414a is 5.064 μm. The amount of displacement is 5.06 × 10 ⁻² times the width dimension B of the annular seal surface 414a or 10.10 × 10 ⁻⁴ times the center diameter A in the width direction. Therefore, Example 1 is provided with the convex part 416, whereby the displacement amount of the annular seal surface 414a is suppressed to 82% with respect to the displacement amount of the annular seal surface 414a of Example 10.

  In the first embodiment, the displacement amount above the P portion of the annular seal protrusion 414 (X26 in FIG. 10) is smaller than the displacement amount above the P portion in the tenth embodiment (see X16 in FIG. 19). Further, in Example 1, as indicated by X26 and X27 in FIG. 10, the displacement amount is changed concentrically around the axis as compared with Example 10. Therefore, it can be seen that in Example 1, the vicinity of the valve seat side end surface 1411a of the valve body 241 is less likely to be deformed in the radially outward direction than in Example 10 (easily deformed in the vertical direction to which a seal load is applied).

  Therefore, in the first embodiment, by providing the convex portion 416, the valve seat side end surface 1411a is deformed so as to bend toward the valve seat side, and the annular seal protrusion 414 is deformed so as to bend in the radially outward direction. It is possible to suppress the amount of displacement of the annular seal surface 414a. This is probably because the cylindrical portion 1411 is reinforced at the center by the convex portion 416 and the rigidity is increased in the first embodiment compared to the tenth embodiment.

  The inventors produced the valve body 204 shown in FIG. 5 based on Example 1, and performed a particle test on the valve body 204. The test results are shown in FIG. Since the particle test method is the same as that of the above-described particle test, the description is omitted.

  As shown in FIG. 24, the number of particles measured by the valve body 204 during the particle test was 4.44 per mL. Therefore, the valve body 204 is less likely to generate particles than the valve body 104. Further, the number of particles measured in the particle test of the valve body 204 was as small as a quarter of that of the valve body 104. Therefore, the valve body 204 can reduce the amount of particles by including the convex portion 416.

  The inventors took a photomicrograph of the annular seal surface 414a for the valve element 204 after the particle test. When the magnification of the photomicrograph was set to 500, no burr was observed in the Q part and the R part of the annular seal surface 414a. Furthermore, the inventors increased the magnification of the micrograph from 500 times to 2000 times, and confirmed the state of the valve body 204 near the Q portion of the annular seal surface 414a. A micrograph of the valve body 204 and an image thereof are shown in FIGS. As shown by Z4 in FIGS. 28 and 29, the valve body 204 is not confirmed to have any wrinkles, scratches or burrs in the Q portion of the annular seal surface 414a. On the contrary, the valve body 204 is in a state where the irregularities on the surface of the Q portion are familiar. Therefore, it is considered that the valve body 204 can suppress or prevent the generation of fine particles that cannot be measured by the particle counter as well as the particles that can be measured by the particle counter.

<(D) Effect of annular concave groove on displacement amount of annular seal surface>
As shown in FIG. 3, Examples 8 and 9 that differ only in the presence or absence of the annular groove 415 are compared. In the eighth embodiment, an annular concave groove 1144 is formed between the convex portion 1143 and the annular seal protrusion 414. The convex portion 1143 is formed with a base end diameter of 4 mm and a height I of 0.4 mm. In Example 9, an annular groove is not formed between the convex portion 7416 and the annular seal protrusion 414. The height I of the convex portion 7416 is the same as that of the convex portion 1143.

In FIG. 18, the displacement amount analysis result of Example 9 is shown. As indicated by X76, in the valve main body 741, the deformation generated in the radially outward direction at the convex portion 7416 is directly transmitted to the annular seal protrusion 414. Therefore, as indicated by X71 to X74 in the figure, the annular seal protrusion 414 is pushed out radially by the convex portion 7416. As shown in FIG. 23, in Example 9, the amount of displacement of the annular seal surface 414a is 4.302 μm. The amount of displacement is 8.60 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414 a or 4.30 × 10 ⁻² times the width dimension B.

In FIG. 17, the displacement amount analysis result of Example 8 is shown. In the valve main body 1141, the deformation generated in the radially outward direction at the convex portion 1143 is not easily transmitted from the annular concave groove 1144 to the annular seal protrusion 414. Therefore, as indicated by X111 to X115 in the drawing, the annular seal protrusion 414 mainly deforms in the vertical direction, and presses the annular seal surface 414a in the substantially vertical direction against the valve seat surface 24a. As shown in FIG. 23, in Example 8, the displacement amount of the annular seal surface 414a is 3.736 μm. The amount of displacement is 7.47 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414a or 3.74 × 10 ⁻² times the width dimension B.

  As described above, the valve body can suppress the amount of displacement of the annular seal surface in the radially outward direction from the valve body including only the convex portion by forming the annular concave groove between the convex portion and the annular seal protrusion.

<(E) Effect of proximal end diameter H on the amount of displacement of the annular seal surface>
As shown in FIG. 3, Example 1 and Example 13 which differ only in the base end part diameter H are compared. In Example 1, the base end portion diameter H of the convex portion 416 is set to 4 mm which is the same as the detail diameter J. In Example 13, the base end portion diameter H of the convex portion 944 is set to 2 mm, which is smaller than the detail diameter J (4 mm). The annular groove 415 of the first embodiment is provided wider than the annular groove 945 of the thirteenth embodiment.

In FIG. 22, the displacement amount analysis result of Example 13 is shown. As indicated by X96 in the figure, the valve main body 943 is deformed in the valve seat direction within the range of the convex portion 944. However, as indicated by X97 in the figure, the valve body 943 is deformed in the radially outward direction at a portion outside the convex portion 944 and inside the outer peripheral surface 413a of the neck portion 413. The deformation is directly transmitted to the outer peripheral surface 411b of the cylindrical portion 1411 through the upper portion of the annular seal protrusion 414 in the drawing, as indicated by X98 in the drawing. As indicated by X91 to X94 in the figure, the annular seal protrusion 414 has a larger deformation amount on the outer peripheral surface 414c than on the inner peripheral surface 414b. As shown in FIG. 23, in Example 13, the displacement amount of the annular seal surface 414a is 6.162 μm. This amount of displacement is 12.30 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414 a or 6.16 × 10 ⁻² times the width dimension B.

On the other hand, as shown in FIG. 10, the displacement amount of the first embodiment is changed concentrically around the axis of the valve body 241 as a whole as compared with the thirteenth embodiment. As shown by X21 to X26 in the figure, the valve body 204 has a smaller deformation amount than that of the thirteenth embodiment outside the P portion of the annular seal protrusion 414. And as shown to X21-X24, as for the valve body 204, the deformation amount of P part, Q part, R part, and S part is smaller than Example 13. FIG. As shown in FIG. 23, in Example 1, the amount of displacement of the annular seal surface 414a is 5.064 μm. The amount of displacement is 10.10 × 10 ⁻⁴ times the width direction center diameter A of the annular seal surface 414a and 5.06 × 10 ⁻² times the width dimension B.

  Therefore, the valve body can suppress the amount of displacement of the annular seal surface by setting the base end diameter H to the detail diameter J or more. This is considered because the convex part 416 can support the whole load of a drive part and can disperse | distribute widely.

<(F) Effect of convex portion height I on the amount of displacement of the annular seal surface>
As shown in FIG. 3, Examples 1, 11, and 12 that differ only in the height I of the convex portion are compared. In Example 1, the height I of the convex portion 416 is 0.5 mm, which is the same as the height C of the annular seal protrusion 414. In Example 11, the height I of the convex portion 1243 is 0.35 mm, which is 0.7 times the height C of the annular seal protrusion 414. In Example 12, the height I of the convex portion 1343 is 0.3 mm, which is 0.6 times the height C of the annular seal protrusion 414. 10, 20, and 21 show the displacement analysis results of Examples 1, 11, and 12. FIG.

  As shown in X26 and X27 of FIG. 10, in the first embodiment, the deformation of the convex portion 416 is blocked by the annular concave groove 415 and is not easily transmitted to the annular seal projection 414, and the annular seal projection 414 is deformed mainly in the vertical direction. Yes. On the other hand, as shown by X126 and X128 in FIG. 20 and X138 in FIG. 21, in the examples 11 and 12, the deformation of the convex portions 1243 and 1343 in the radial direction exceeds the annular concave grooves 1244 and 1344, and the annular seal. It is easy to be transmitted to the upper part of the projection 414 in the figure. Further, as shown by X123 in FIG. 20, in the eleventh embodiment, the displacement amount of the R portion is larger than that in the first embodiment. Further, as shown by X133 in FIG. 21, the displacement amount of the outer peripheral surface 414c of the annular seal protrusion 414 is larger in the thirteenth embodiment than in the first and tenth embodiments. As shown in FIG. 23, the displacement amount of the annular seal surface 414a is 5.064 μm in Example 1, 5.644 μm in Example 11, and 5.678 μmm in Example 12. Therefore, as the height I of the convex portion 416 is higher, the displacement amount of the annular seal surface 414a is suppressed. This is considered to be because as the height I is higher, the deformation is widely dispersed at the convex portion, and the amount of deformation transmitted to the annular seal surface 414a can be suppressed. Further, it is considered that the annular concave groove is formed deeply and the deformation of the convex portion is hardly transmitted to the annular seal protrusion.

<(G) Effect of combination of end face diameter D and wall thickness F on the amount of displacement of the annular seal surface>
As shown in FIG. 3, Examples 2 and 3 having different end face diameters D and wall thicknesses F are compared. In Example 2, the end face diameter D is 7.5 mm, and the wall thickness F is 4.5 mm. On the other hand, Example 3 has an end face diameter D of 8.5 mm and a wall thickness F of 5.4 mm. 11 and 12 show the displacement amount analysis results of Examples 2 and 3. FIG.

In the third embodiment, the displacement amounts of the P portion, the Q portion, the R portion, and the S portion shown in X41 to X44 in FIG. 12 are smaller than those in the second embodiment (see X31 to X35 in FIG. 11), and the annular seal protrusion 414 is obtained. Is deformed vertically. Further, in the valve body portion 440 of the third embodiment, the amount of displacement changes in a circular shape around the axis, as compared with the valve body portion 340 of the second embodiment. As shown in FIG. 23, in Example 2, the displacement of the annular seal surface 414a was 4.037 μm. The amount of displacement is 8.07 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414a or 4.04 × 10 ⁻² times the width dimension B. On the other hand, in Example 3, the displacement amount of the annular seal surface 414a was 3.224 μm. The amount of displacement is 6.45 × 10 ⁻⁴ times the center diameter A in the width direction of the annular seal surface 414 a or 3.22 × 10 ⁻² times the width dimension B.

  Therefore, in the third embodiment, the deformation of the cylindrical portion 4411 and the valve seat side end surface 4411a is smaller than in the second embodiment, and the annular seal protrusion 414 can be pressed perpendicularly to the valve seat surface 24a. Further, in the third embodiment, the annular seal protrusion 414 is pressed perpendicularly to the valve seat surface 24a and is not easily deformed as compared with the second embodiment, and the amount of displacement of the annular seal surface 414a is suppressed. This is because the end face diameter D and the wall thickness F are larger in the third embodiment than in the second embodiment, so that the load of the drive unit 3 is widely dispersed at a position away from the valve seat side end face 4411a, and the annular seal protrusion 414 is It is thought that it can be pressed vertically against the seat 24.

  The inventors produced valve bodies 304 and 404 based on Examples 2 and 3, and performed a particle test. Since the particle test method is the same as that of the particle test described above, the description thereof is omitted. The results of this particle test are shown in FIG.

  As shown in FIG. 24, the number of particles measured by the valve body 304 during the particle test was 2.22 per mL. The number of particles is reduced to about 1/9 of that in Example 10. On the other hand, as shown in FIG. 24, particles were not measured in the valve body 404 during the particle test. Therefore, the larger the end face diameter D and the wall thickness F of the cylindrical portion 411, the greater the effect of suppressing particles. This is because the rigidity is increased.

  In addition, the inventors took a photomicrograph of the annular sealing surface 414a at a magnification of 2000 times for the valve bodies 304 and 404 for which the particle test was completed. In the valve bodies 304 and 404, no burr was confirmed on the annular seal surface 414a. The valve body 404 had a smoother Q surface than the valve body 304. This is presumably because the valve body 404 is licked by pressing the annular seal protrusion 414 in the vertical direction from the valve body 304.

  Therefore, it can be considered that the larger the end face diameter D and the wall thickness F of the valve body, the smaller or smaller the generation of fine particles that cannot be measured by the particle counter as well as the particles that can be measured by the particle counter.

<(H) About the effect which the combination of a convex part and the end surface diameter D has on the displacement amount of an annular seal surface>
By the way, as in the third embodiment, when the end face diameter D is increased, the diaphragm chamber 22 becomes wider, and the valve body 21 becomes larger. In addition, since the fluid pressure acting on the valve seat side end surface 4411a is increased, the drive unit is increased in order to increase the seal load. On the other hand, when the wall thickness F is large, a staying portion is easily formed in the diaphragm chamber 22. In addition, since the diaphragm chamber 22 becomes wider, the valve body 21 becomes larger. Therefore, as shown in FIG. 3, the inventors analyzed the displacement amount of Example 4 in which the end face diameter D and the wall thickness F are smaller than those of Example 3 and provided with a convex portion 416. The displacement amount analysis result of the valve body 4 of Example 4 is shown in FIG.

  As shown in FIG. 3, Example 3 has an end face diameter D of 8.5 mm, a wall thickness F of 5.4 mm, and does not include a convex portion. On the other hand, Example 4 has an end face diameter D of 7.5 mm, a wall thickness F of 4.5 mm, and a convex portion 416. 12 and 13 show the displacement amount analysis results of Examples 3 and 4. FIG.

  As shown in FIG. 13, the valve main body 41 of the fourth embodiment has a convex portion 416 that has a central portion with increased rigidity, and the central portion is less likely to deform radially outward than the third embodiment (see FIG. 12). And as shown to X6 and X7 of FIG. 13, even if the convex part 416 deform | transforms into an outer diameter direction, the deformation | transformation is not easily transmitted to the annular seal protrusion 414 by the annular recessed groove 415. Further, as shown in X1 to X4 of FIG. 13, the valve body 41 of the fourth embodiment has a displacement amount of the P portion, the Q portion, the R portion, and the S portion of the annular seal protrusion 414 according to the third embodiment (X41 in FIG. 12). To X44). As shown in FIG. 23, the displacement amount of the annular seal surface 414a is 3.687 μm. In Example 3, the displacement amount of the annular seal surface 414a is 3.224 μm.

  As described above, even though the end face diameter D is about 0.88 times that of Example 3 and the wall thickness F is about 0.83 times that of Example 3, the convex portion 416 is formed in Example 4. By providing the annular concave groove 415, the amount of displacement of the annular seal surface 414a is made substantially the same as in the third embodiment. Therefore, compared with Example 3, Example 4 can make the drive part 3 and the valve body 21 compact. Thereby, in Example 4, the displacement amount of the annular seal surface 414a can be suppressed, wear can be reduced, particles can be suppressed, and the valve size can be made compact. Further, since the fourth embodiment suppresses the deterioration of the valve main body 41, the initial sealing force can be maintained for a long period of time, and the valve maintenance interval can be widened.

<(I) About the effect which the combination of a convex part, the thickness F, and height G gives to the displacement amount of an annular seal surface>
As shown in FIG. 3, Examples 4, 5, and 6 having different thicknesses F and heights G are compared. In Examples 4, 5, and 6, the position of the T portion and the convex portion 416 and the annular concave groove 415 are similarly provided. In Examples 4, 5, and 6, the thickness F is adjusted according to the height G and the inclination angles of the shoulder portions 412, 543, and 643. In Example 4, the wall thickness F is 4.5 mm which is 0.9 times the center diameter A (5 mm) in the width direction of the annular seal surface 414a. In Example 4, the height G is 2.65 mm. In Example 5, the thickness F is 4.0 mm, which is 0.8 times the center diameter A (5 mm) in the width direction of the annular seal surface 414a. In Example 5, the height G is 2.15 mm. In Example 6, the wall thickness F is 3.5 mm, which is 0.7 times the width direction central diameter A (5 mm) of the annular seal surface 414a. In Example 4, the height G is 1.65 mm. The displacement amount analysis results of the valve bodies 4, 504, and 604 of Examples 4 to 6 are shown in FIGS.

  As shown in FIGS. 13, 14, and 15, in Examples 4, 5, and 6, the central portions of the valve bodies 41, 541, and 641 are enhanced in rigidity by the convex portions 416, and are not easily deformed radially outward. The deformation in the radial direction generated in the convex portion 416 is not easily transmitted to the annular seal protrusion 414 by the annular concave groove 415. As shown in FIGS. 13, 14, and 15, the valve bodies 41, 541, and 641 change in concentric circles around the axis, and are easily deformed in the vertical direction. As shown by X5 to X7 in FIG. 13, X55 to X57 in FIG. 14, and X65 to X67 in FIG. 15, the deformation of the valve seat side end surfaces 411a, 5411a, 6411a is suppressed to the same extent, and the annular seal protrusion 414 is It is pressed perpendicularly to the surface 24a. Further, as shown by X1 to X4 in FIG. 13, X51 to X54 in FIG. 14, and X61 to X64 in FIG. 15, the fourth, fifth, and sixth examples are displacement amounts of the P point, the Q point, the R point, and the S point. And the annular seal protrusion 414 is deformed in the vertical direction. As shown in FIG. 23, in Example 4, the displacement amount of the annular seal surface 414a is 3.687 μm. In Example 5, the displacement amount of the annular seal surface 414a is 4.100 μm. In Example 6, the displacement amount of the annular seal surface 414a is 4.685 μm.

  Therefore, even if the height of the valve body is reduced and the volume of the diaphragm chamber is increased, the valve element can suppress the amount of displacement of the annular seal surface by increasing the inclination of the shoulder and ensuring the thickness F. Further, the height of the valve body is low and the inclination of the shoulder portion is increased, so that the fluid is less likely to stay in the diaphragm chamber. This makes it difficult for the accumulated fluid to deteriorate or to solidify into particles.

<Relationship between the amount of displacement of the annular seal surface and the number of particles>
Based on the result of the particle test described above, the relationship between the amount of displacement of the annular seal surface and the number of generated particles is summarized as shown in FIG. As shown in FIG. 24, the smaller the displacement amount of the annular seal surface 414a is 6.175 μm, 5.064 μm, 4.037 μm, and 3.224 μm, the number of generated particles is 17.78, 4.44, 2 Reduced to 22 and 0. Furthermore, in the unmeasured sample in which the displacement amount of the annular seal surface 414a exceeds 6.175 μm and is 9 μm or less, the number of particles generated increases rapidly to 797.8. Therefore, the valve body can effectively reduce particles by setting the displacement amount of the annular seal surface 414a to 6.175 μm or less.

  In particular, as shown in FIGS. 26 to 29, the valve body 104 of Example 10 in which the displacement amount of the annular seal surface 414a is 6.175 μm and the displacement amount of the annular seal surface 414a is 5.064 μm. In the valve body 204, the valve body 204 is less rough on the annular seal surface 414a, and burrs are less likely to occur. Therefore, it is considered that the valve body 204 of Example 1 can effectively suppress or prevent the generation of fine particles from the annular seal surface 414a than the valve body 104 of Example 10. Therefore, the fluid control valve has a shape in which the displacement amount of the annular seal surface is made as small as possible, so that the cause of particle generation itself can be eliminated even if particles that are a problem in semiconductor manufacturing are miniaturized. Further, the life of the valve body can be extended, and the maintenance burden on the fluid control valve 1 can be reduced.

<Others>
The inventors also have a configuration in which the valve seat side end surface 411a is flattened without providing the annular seating protrusion 414 on the valve seat side end surface 411a of the diaphragm valve body 104, and a convex portion is provided along the outer periphery of the opening of the valve seat 24. investigated. However, with this configuration, the wear and particles on the annular seal surface generated when the valve is closed cannot be reduced as much as the diaphragm valve body 104 of the present embodiment.

B. Second Embodiment Subsequently, a fluid control valve according to a second embodiment of the present invention will be described. The fluid control valve of the second embodiment is different from the diaphragm valve body 4 (Example 4) of the fluid control valve 1 of the first embodiment only in the material of the valve body. Here, the reference numeral of the valve body of the second embodiment is “4A”, and the other reference numerals are the same as those used in the first embodiment.

  4A of valve bodies of 2nd Embodiment are shape | molded by the same shape as the diaphragm valve body 4 of 1st Embodiment by cutting the round bar made from PFA. PFA has higher hardness than PTFE and is less likely to wear. Therefore, compared with the PTFE diaphragm valve body 4 according to the first embodiment, the cylindrical body 411 and the annular seal protrusion 414 are less likely to be deformed even when the valve body 4A receives a seal load. Therefore, in the fluid control valve of the second embodiment, the annular seal surface 414a of the valve body 4A is less likely to rub against the valve seat surface 24a as compared with the fluid control valve 1 of the first embodiment, and is generated when the valve is closed. Since the wear due to the deformation of the valve body 4A is suppressed, the generation of particles can be reduced.

  Here, the inventors took micrographs for the annular seal surfaces 414a of the valve body 4A and the diaphragm valve body 4 at the initial stage before use and after the valve opening / closing operation 5000 times. In the valve body 4A, there was almost no change in the annular seal surface 414a between the initial time and after 5000 operations, and almost no wrinkles or scratches were observed on the annular seal surface 414a. On the other hand, when the diaphragm valve body 4 was operated 5000 times, fine wrinkles and scratches were confirmed near the inner edge of the annular seal surface 414a. Therefore, if the annular seal protrusion 414 is formed of PFA, wear of the annular seal surface 414a generated when the valve is closed can be suppressed or reduced, and fine particles are hardly generated.

  In addition, the inventors conducted a wear particle collection test on the valve body 4A and the diaphragm valve body 4. The test apparatus has a primary filter that removes foreign matters of 5 μm or more in order from the upstream side, a test target (a fluid control valve equipped with the valve body 4A or a fluid control valve equipped with the diaphragm valve body 4), 50 nm or more. It was configured by arranging a secondary filter for removing foreign matter. The test was performed by measuring the number of particles collected by the secondary filter after allowing the test object to perform a valve opening / closing operation 40000 times while supplying pure water to the primary filter at 30 ml / min. Since the primary filter removes foreign matters contained in the pure water, the particles collected by the secondary filter are considered to be particles generated by wear of the valve bodies 4 and 4A.

  The test results showed that the number of wear particles collected was 41 in the fluid control valve equipped with the diaphragm valve body 4. On the other hand, in the fluid control valve equipped with the valve body 4A, the number of collected wear particles was 14. Therefore, the valve body 4A formed of PFA was able to reduce the number of wear particles collected by 65% compared to the diaphragm valve body 4 formed of PTFE. From this test result, it was confirmed that the annular seal protrusion 414 was less likely to generate wear particles when formed with PFA than with PTFE.

C. Third Embodiment Subsequently, a fluid control valve according to a third embodiment of the present invention will be described. FIG. 31 shows a cross-sectional view of the valve body 9 used in the fluid control valve according to the third embodiment of the present invention. 32 and 33 show valve bodies 109 and 209 of first and second modifications. The valve body 9, 109, 209 is different from the valve body 4A of the second embodiment in that two parts formed of different materials are combined, and other configurations are the same as those of the valve body 4A of the second embodiment. Common. In the following description, the same reference numerals as those in the second embodiment are used for the same components as those in the second embodiment, and the description thereof will be omitted as appropriate, with a focus on differences from the second embodiment.

  As described in the second embodiment, since the valve body 4A is formed of PFA, wear of the annular seal surface 414a that occurs when the valve is closed is reduced, and generation of wear particles can be suppressed. However, PFA is difficult to mold by cutting due to the difficulty of obtaining material. Therefore, as shown in FIG. 31, the valve body 9 of the third embodiment includes a first component 91 and a second component 92 between the neck portion 413 and the shoulder portion 412 (valve body portion 410) of the valve body 93. It is divided. The first part 91 is made of PTFE, the second part 92 is made of PFA, and the first part 91 and the second part 92 are integrated by insert molding. The first component 91 includes a thin film portion 42, an outer edge portion 43, and a neck portion 413 of the valve main body 93. On the other hand, the second component 92 includes a shoulder portion 412, a cylindrical portion 411, an annular seal protrusion 414, an annular concave groove 415, and a convex portion 416 of the valve body 93.

  PFA can be melt-molded, which is difficult with PTFE. PFA has a lower melting point than PTFE. On the other hand, PTFE is easy to obtain materials, and is easier to mold by cutting than PFA. Therefore, the valve body 9 is formed by the first component 91 cutting out a PTFE round bar. Then, the second component 92 flows and solidifies the melted PFA around the connection protrusion 91a in a state where the connection protrusion 91a provided to protrude in the axial direction in the first component 91 is inserted into the mold. Is formed. Therefore, in the second component 92, the cylindrical portion 411, the annular seal protrusion 414, the annular concave groove 415, and the convex portion 416 are easily and accurately formed by melt molding. In addition, since the first component 91 including the neck portion 413 is formed of a resin having a lower hardness than PFA (for example, PTFE), the second component 92 including the annular seal protrusion 414 and coupled to the first component 91 is formed of PFA. It is easy to form the valve body 9 in which the annular seal protrusion 414 is formed of PFA.

  In the valve body 9, since the first part 91 is insert-molded into the second part 92, there is almost no gap between the first part 91 and the second part 92. In addition, in the valve body 9, irregularities are formed in the circumferential direction on the outer peripheral surface of the connecting convex portion 91 a, and the second component 92 and the first component 91 are coupled in a state where the irregularities are filled with PFA. Therefore, even if the fluid control valve repeats the valve opening / closing operation, it is difficult to form a gap between the second component 92 and the first component 91. Therefore, in the fluid control valve to which the valve body 9 is attached, it is difficult for fine particles to enter between the first component 91 and the second component 92, and chemicals or the like are placed between the first component 91 and the second component 92. It is difficult to generate particles by entering and solidifying. Furthermore, since the annular seal protrusion 414 and the cylindrical portion 411 are formed of PFA and are not easily deformed in the valve body 9, wear of the annular seal surface 414a that occurs when the valve is closed can be suppressed, and particles can be reduced.

  The valve body 109 of the first modification shown in FIG. 32 has a press-fit groove 191a formed in an annular shape on the valve seat side end surface 411a of the first component 191, and the ring-shaped second component 192 is press-fitted into the press-fit groove 191a. Yes. The annular seal protrusion 414 is constituted by the second part 192. The first part 191 is made of PTFE, and the second part 192 is made of PFA. Since the annular seal protrusion 414 is formed of PFA and hardly deforms in the valve body 109, the generation of particles is reduced by suppressing the wear of the annular seal surface 414a that occurs when the valve is closed. The valve body 109 has a gap between the second part 192 and the inner wall of the press-fitting groove 191a, and there is a risk that dust will enter. Further, since the valve body 109 couples the first part 191 and the second part 192 by press-fitting the second part 192 into the press-fitting groove 191a, the cylindrical part 411, the annular seal protrusion 414, the annular concave groove between the products. There is a possibility that variations occur in the dimensions of the convex portions 416 and 415.

  The valve body 209 of the second modification shown in FIG. 33 has a third feature only in that a male threaded portion 291a is projected from the first component 291 and the male threaded portion 291a is screwed into the female threaded portion 292a of the second component 292. It differs from the valve body 9 of the embodiment. In the valve body 209, since the cylindrical portion 411 and the annular seal protrusion 414 are formed of PFA and are not easily deformed, generation of particles can be reduced by suppressing wear of the annular seal surface 414a that occurs when the valve is closed. In the valve body 209, there is always a gap between the male screw portion 291a and the female screw portion 292a, and there is a possibility that fine dust may enter the gap.

  Therefore, when the valve body is composed of two parts, the first part 91 and the second part 92 are integrated by insert molding as in the valve body 9, and the particle suppression effect is the highest. The valve bodies 109 and 209 can obtain the same particle suppression effect as that of the valve body 9 if the gap formed between the first parts 191 and 291 and the second parts 192 and 292 is filled with resin or the like. Moreover, if it is press-fitting and screw fastening, an insert mold is unnecessary, and it can be applied to any shape and is highly versatile.

  The present invention is not limited to the above embodiment, and various applications are possible.

(1) For example, in the above embodiment, the fluid control valve 1 is applied to a semiconductor manufacturing apparatus, but may be applied to another apparatus.

(2) For example, in the said embodiment, although the valve body part 410 is provided with the cylindrical part 411 and the shoulder part 412, you may make a valve main body into a cone shape.

(3) For example, in the said embodiment, although the fluid control valve 1 was comprised as a diaphragm valve, the shape of annular diaphragm protrusion 414 vicinity of the diaphragm valve body 4 is provided in the valve body which does not have thin film parts, such as a bellows valve and an electromagnetic valve. May be applied to suppress the displacement of the annular seal surface.

(4) For example, in the above embodiment, the thin film portion 42 is connected to the neck portion 413. On the other hand, the thin film portion 42 may be connected to the connecting portion between the shoulder portion 412 and the neck portion 413 as shown in the valve body 4B of the third modification shown in FIG. As shown in the valve body 4C of the fourth modification, it may be connected to the cylindrical portion 411.

(5) For example, in the said embodiment, the diaphragm valve body 4 and the drive part 3 were connected by screwing the external thread part 413b of the diaphragm valve body 4 with the internal thread part 35c of the drive part 3. FIG. On the other hand, like the valve body 4D of the fifth modified example shown in FIG. 36, the internal thread portion 420 is formed in the neck portion 413, and the external thread portion that is screwed into the internal thread portion 420 is provided in the piston 35 of the drive unit 3. Thus, the valve body 4D may be connected to the drive unit 3.

(6) The material of the diaphragm valve body 4 may be modified PTFE (modified polytetrafluoroethylene) hardness D55-60 or PFA (tetrafluoroethylene / perfluoroalkylvinylether copolymer) hardness D60-64.

(7) The material of the valve body 21 (valve seat 24) may be PTFE (polytetrafluoroethylene) hardness D53-58 or modified PTFE (modified polytetrafluoroethylene) hardness D55-60.

(8) There may be corner corner chamfering or corner portion R chamfering of the annular seal surface 414a. In this case, the diameter of the center position between the inner periphery and the outer periphery of the flat surface corresponds to the “diameter of the annular seal portion”. Further, the annular seal surface 414a may be an annular seal portion in which the tip end portion of the annular seal protrusion 414 has an R shape, in addition to the flat shape. In this case, the diameter of the apex portion where the annular seal portion faces the valve seat corresponds to the “diameter of the annular seal portion”. Even in these cases, if the shape around the annular seal protrusion 414 is configured so that the compressive deformation generated in the valve body 41 of the diaphragm valve body 4 occurs only in the vertical direction (for example, the diameter of the cylindrical portion 411 and the convex portion 416). And the annular concave groove 415), and the same effect as the above embodiment can be obtained.

(9) The bottom surface of the annular groove 415 may be the same as or substantially the same height as the valve seat side end surface 411a.

(10) The valve seat side end surface 411a is not limited to a flat shape, and may be a slope or a curved surface.

(11) The amount of displacement of the annular seal surface 414a necessary for suppressing particle generation is not limited to the radially outer displacement amount, but may be an inner displacement amount.

(12) The annular seal protrusion may be provided in a cylindrical shape, and the thickness in the radial direction from the valve seat side to the counter valve seat side may be constant.

(13) The protrusion shape of the annular seal protrusion may be a shape in which the wall shape on the radial axis side of the valve body is different from the wall shape on the radially opposite axis side. The shape of the wall and the height of the protrusion may be set so that the amount of displacement of the annular seal surface (annular seal portion) is small.

(14) The D / A is not limited to the above embodiment, and may be 1.35, 1.40, 1.45, or the like. As shown in FIG. 25, when D / A is increased, the amount of displacement of the annular seal surface 414a is reduced, and generation of particles can be suppressed.

DESCRIPTION OF SYMBOLS 1 Fluid control valve 3 Drive part 4 Diaphragm valve body (an example of a valve body)
24 valve seat 414 annular seal protrusion 414a annular seal surface (an example of an annular seal portion)
415 Annular groove 416 Convex A Width center diameter B of the annular seal surface Diameter width dimension D of the annular seal surface Diameter F of the valve seat side end surface Thickness H in the axial direction from the radial center position of the annular seal surface Convex Diameter of the base end I of the convex part Height J of the convex part Diameter of the narrowest part between the pressure-receiving surface receiving the load from the drive unit and the end face on the valve seat side

Claims (9)

A drive unit;
A valve body having a first port, a second port and a valve seat;
Having a valve body formed in a columnar shape and connected to the drive unit;
The valve body has an annular seal protrusion that is provided on the distal end with an annular seal portion that is annularly projected on a valve seat side end surface located on the valve seat side and is pressed against the valve seat for sealing. The annular seal protrusion is made of fluororesin,
The valve body is characterized in that when the annular seal portion is pressed against the valve seat by the driving portion, a displacement amount of the annular seal portion displaced in the radial direction is 3.224 μm or more and 6.175 μm or less. Fluid control valve. A drive unit;
A valve body having a first port, a second port and a valve seat;
Having a valve body formed in a columnar shape and connected to the drive unit;
The valve body has an annular seal protrusion that is provided on the distal end with an annular seal portion that is annularly projected on a valve seat side end surface located on the valve seat side and is pressed against the valve seat for sealing. The annular seal protrusion is made of fluororesin,
When the annular seal portion is pressed against the valve seat by the drive unit, the valve body has an annular seal portion when a displacement amount of the annular seal portion displaced in the radial direction is not in contact with the valve seat. 6. A fluid control valve characterized in that it is 6.45 × 10 ⁻⁴ times or more and 12.4 × 10 ⁻⁴ times or less with respect to the diameter. A drive unit;
A valve body having a first port, a second port and a valve seat;
Having a valve body formed in a columnar shape and connected to the drive unit;
The valve body has an annular seal protrusion projecting annularly on a valve seat side end surface located on the valve seat side, at least the annular seal protrusion is made of fluororesin, and at the tip of the annular seal protrusion, An annular seal portion that is pressed against and seals the valve seat is formed flat.
When the annular seal portion is pressed against the valve seat by the drive unit, the valve body has the annular seal portion in a case where the displacement amount of the annular seal portion displaced in the radial direction is not in contact with the valve seat. The fluid control valve is characterized in that it is 3.22 × 10 ⁻² times or more and 6.18 × 10 ⁻² times or less of the width dimension. A drive unit;
A valve body having a first port, a second port and a valve seat;
Having a valve body formed in a columnar shape and connected to the drive unit;
The valve body has an annular seal protrusion that is provided on the distal end with an annular seal portion that is annularly projected on a valve seat side end surface located on the valve seat side and is pressed against the valve seat for sealing. The annular seal protrusion is made of fluororesin,
The diameter of the end face on the valve seat side is not less than 1.3 times the diameter of the annular seal portion when not in contact with the valve seat.
A fluid control valve characterized by 5. The fluid control valve according to claim 1, wherein a diameter of the narrowest portion of the valve body is smaller than a diameter of the annular seal portion. 6. The valve body according to claim 5, wherein a thickness in an axial direction at a radial center position of the annular seal portion is 0.7 times or more with respect to a diameter of the annular seal portion. Fluid control valve. 7. The fluid control valve according to claim 5, wherein the valve body has a convex portion protruding in a valve seat direction from the end face on the valve seat side inside the annular seal protrusion. 8. The fluid control valve according to claim 7, wherein the convex portion has a diameter of a base end portion connected to the valve seat side end surface equal to or larger than a diameter of a thinnest portion of the valve body. 9. The fluid control valve according to claim 1, wherein the annular seal protrusion is formed of PFA.