JP7187015B2 - Diaphragm valve and flow controller - Google Patents

Description

The present invention relates to diaphragm valves, flow control devices, fluid control devices, and semiconductor manufacturing equipment.

2. Description of the Related Art Mass flow controllers are widely used to control the flow rate of process gases used in semiconductor manufacturing processes and the like. For example, in the case of a pressure-type mass flow controller, this mass flow controller measures the mass flow using the pressure before and after the orifice provided in the flow path, and controls the control valve so that the mass flow reaches the target value. is adjusted by Diaphragm valves are widely used as such control valves.

The diaphragm valve, for example, as shown in FIG. 7, has a structure in which a diaphragm 17 made of a thin metal plate or the like is pressed by a driving portion 12 to elastically deform, thereby opening and closing the flow path and adjusting the degree of opening. . The diaphragm 17 is a spherical shell-shaped member with its central portion bulging upward, and is arranged to seal a valve seat 16 e formed on the upper surface of the valve body 16 . An annular holding adapter 18 is arranged on the outer peripheral edge of the diaphragm 17, and is held down by a member called a bonnet 10 from above, thereby hermetically sealing the flow path 16a. The bonnet 10 is fastened together with the support plate 3 to the valve body 16 with two bolts 13 and also functions as a guide for the stem 8 that drives the diaphragm 17 .

International publication number WO2017/033423A1

However, in the above mechanism, depending on the balance between the tightening forces of the two bolts 13 when the bonnet 10 and the support plate 3 are tightened together, the bonnet 10 may tilt and the presser adapter 18 may not be pressed appropriately. There was a risk of fluid leakage from the outer periphery of 17 .

An object of the present invention is to solve the above problems and to provide a diaphragm valve capable of sealing the diaphragm more reliably.

The diaphragm valve of the present invention is
A valve body having a flow channel inside and having a diaphragm placement portion on one surface, a diaphragm placed in the diaphragm placement portion and capable of opening and closing the flow channel and adjusting the degree of opening by elastic deformation, and the valve. A diaphragm valve having a drive unit including a stem attached to a body and driven by an actuator to elastically deform the diaphragm,
The diaphragm placement portion is a recess having a threaded inner peripheral surface,
It further has a substantially cylindrical inner bonnet screwed to the inner peripheral surface of the diaphragm placement portion, and the inner bonnet presses and fixes the diaphragm at its end, and the inner peripheral portion displaces the stem in the axial direction. It is characterized by being able to hold.

Preferably, the inner bonnet can adopt a configuration in which the stem is guided via a resin sleeve.

Alternatively, the inner bonnet can be configured to guide the stem via an O-ring.

The flow control device of the present invention uses the diaphragm valve having the above configuration.

A fluid control device of the present invention is a fluid control device in which a plurality of fluid devices are arranged from upstream to downstream,
The plurality of fluid devices include the diaphragm valve or flow control device having the above configuration.

The semiconductor manufacturing apparatus of the present invention uses the diaphragm valve or the flow rate control device having the configuration described above for controlling the process gas in a semiconductor device manufacturing process that requires a treatment step using a process gas in a sealed chamber.

According to the present invention, instead of a structure in which the bonnet is tightened with two screws and the diaphragm is fixed by the bonnet, a cylindrical inner bonnet is screwed to the inner peripheral surface of the diaphragm placement portion to fix the diaphragm. As a result, a diaphragm valve that solves the problem of fluid leakage from the periphery of the diaphragm due to insufficient tightening balance is realized.

1 is a schematic cross-sectional view of a diaphragm valve according to a first embodiment of the present invention; FIG. FIG. 2 is an enlarged sectional view showing the diaphragm pressing mechanism of FIG. 1; FIG. 5 is an enlarged cross-sectional view showing a diaphragm pressing mechanism of a diaphragm valve according to a second embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS The schematic sectional drawing of the flow control apparatus which concerns on one Embodiment of this invention. 1 is a schematic perspective view of a fluid control device according to one embodiment of the present invention; FIG. 1 is a block diagram of a semiconductor manufacturing apparatus according to one embodiment of the present invention; FIG. FIG. 4 is an enlarged cross-sectional view showing a diaphragm pressing mechanism of a conventional diaphragm valve;

(First embodiment)
A diaphragm valve according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic sectional view of a diaphragm valve 1 according to this embodiment, and FIG. 2 shows an enlarged sectional view of its diaphragm pressing mechanism.

As shown in FIG. 1 , the diaphragm valve 1 of this embodiment includes a valve body 16 , a diaphragm 17 and a driving portion 12 .

The valve body 16 has a substantially block shape and has an upstream channel 16a and a downstream channel 16b therein. As shown in FIG. 2, the upstream flow path 16a opens at the center of the bottom surface of a diaphragm mounting portion 16d, which is a cylindrical depression formed in the upper surface of the valve body 16, and the circumference of this opening rises annularly. form a valve seat 16e. On the other hand, the downstream flow path 16b opens in the peripheral portion of the bottom surface of the diaphragm placement portion 16d.

In this embodiment, the diaphragm 17 is a spherical shell-shaped member in which the central portion of a metal thin plate such as special stainless steel or a nickel-cobalt alloy thin plate bulges upward. It is arranged so as to be fitted to seal the diaphragm arrangement portion 16d. An annular holding adapter 18 is arranged on the outer peripheral edge of the diaphragm 17, and the lower end of the inner bonnet 11, which will be described later, abuts and presses from thereon, thereby fixing the diaphragm 17 and making the flow path airtight. Sealed.

Between the diaphragm 17 and the valve seat 16e, there is a gap of a predetermined amount, through which the upstream flow path 16a communicates with the diaphragm placement portion 16d sealed by the diaphragm 17, and further downstream flow path. A channel communicating with 16b is formed. When the diaphragm 17 is pressed by the drive unit 12 and comes into contact with the valve seat 16e, the communication between the flow path 16a and the flow path 16b is cut off, and the diaphragm 17 is separated from the valve seat 16e. 16b. This makes it possible to open/close the channel and adjust the degree of opening.

As shown in FIG. 1, the drive unit 12 includes a support plate 3, a piezoelectric actuator 2, displacement transmission mechanisms (4, 7, 6, 5, 5b), a stem 8, a diaphragm presser 19, and a spring 9. have

The support plate 3 holds the piezoelectric actuator 2 and the displacement transmission mechanism (4, 7, 6, 5, 5b) axially displaceable, and is fixed to the valve body 16 with two bolts 13. .

The piezoelectric actuator 2 incorporates laminated piezoelectric elements (not shown) in a cylindrical case 2c. The case 2c is made of a metal such as a stainless alloy, and has a closed end face on the hemispherical distal end portion 2a side and an end face on the proximal end portion 2b side. By applying a voltage to the laminated piezoelectric element to extend the case 2c, the end face of the case 2c on the side of the tip 2a is elastically deformed, and the hemispherical tip 2a is displaced in the longitudinal direction. That is, the case 2c extends its full length from the distal end portion 2a to the proximal end portion 2b by applying a voltage to the stacked piezoelectric elements.

The piezoelectric actuator 2 is arranged vertically so that the tip portion 2 a contacts the support plate 3 . The tip of the tip portion 2a has a hemispherical shape, and in this embodiment, is designed to fall into a conical recess formed on the upper surface of the support plate. A base end portion 2b of the piezoelectric actuator 2 is fitted and held by a pressing member 4 which is a receiving portion of the displacement transmission mechanism (4, 7, 6, 5, 5b).

The upper surface of the pressing member 4 is in contact with the tip of the adjusting screw 7 screwed into the screw hole of the upper connecting member 6 . The upper connecting member 6 has a substantially U-shape formed by cutting a bottomed cylinder upside down, and a pair of displacement transmitting members 5 are connected to the inner side thereof by screws.

The pair of displacement transmission members 5 is made of a metal material such as Invar having a small coefficient of thermal expansion, and has a configuration in which a cylindrical member along the outer peripheral surface of the piezoelectric actuator 2 is divided into two along the longitudinal direction. . The pair of displacement transmission members 5 extend downward through the openings 5a through which the support plate 3 is inserted, and have engaging portions 5b formed at their distal ends.

On the other hand, the stem 8 is disposed below the support plate 3 coaxially with the piezoelectric actuator 2 and is movable in the axial direction. The stem 8 is provided with arm portions 8a with which the engaging portions 5b formed at the lower end portions of the pair of displacement transmission members 5 are engaged. The stem 8 is biased downward by a spring 9 . When the piezoelectric actuator 2 expands, the stem 8 is also lifted upward by the pair of displacement transmission members 5 against the biasing force of the spring 9 . Thus, the displacement of the length of the piezoelectric actuator 2 is transmitted to the stem through a series of displacement transmission mechanisms (4, 7, 6, 5, 5b) to displace the stem in the axial direction.
A diaphragm retainer 19 is attached to the tip (lower end) of the stem 8 and is in contact with the diaphragm 17 .

Here, in the present invention, an inner bonnet 11 is used instead of the conventional bonnet 10 (see FIG. 7). That is, as shown in FIG. 2, the diaphragm placement portion 16d is formed as a recess having threads formed on the inner peripheral surface thereof, and a substantially cylindrical inner tube having a thread formed on the outer peripheral portion is provided on the inner peripheral surface of the diaphragm placement portion 16d. A bonnet 11 is screwed together. The lower end of the inner bonnet 11 presses the pressing adapter 18 to fix the diaphragm 17, and the inner peripheral portion of the inner bonnet 11 holds the stem 8 so as to be displaceable in the axial direction.
Since the diaphragm 17 and the diaphragm 17 are pressed by one substantially concentric screw, the balance is not lost depending on the tightening method.

Further, in this embodiment, the outer circumference of the resin sleeve 15 is fitted and fixed to the inner circumference of the inner bonnet 11, and the inner circumference holds the stem 8 so as to be displaceable in the axial direction. Since the sleeve 15 is made of a self-lubricating resin such as polyacetal, ultra-high molecular weight polyethylene, fluororesin, or phenolic resin, the coefficient of friction with the stainless steel stem 8 to be guided is small, and the stem 8 is held in good condition. I can guide you.

Next, the operation of the diaphragm valve 1 of this embodiment configured in this manner will be described with reference to FIG.

First, in the initial state where the voltage applied to the piezoelectric actuator 2 is zero, the length of the piezoelectric actuator 2 is the minimum at the initial length, and the displacement transmission mechanism (4, 7, 6, 5, 5b) and the The engaged stem 8 is pushed down by the spring 9 to its lowest position. Therefore, the diaphragm 17 is pressed by the stem 8 and adheres tightly to the valve seat 16e, and the valve 1 is fully closed.

Next, when a voltage is applied to the piezoelectric actuator 2, the length of the piezoelectric actuator 2 increases. is pushed up, creating a gap between the diaphragm 17 and the valve seat 16e, opening the valve 1 and allowing fluid to pass through the diaphragm valve 1. By adjusting the voltage applied to the piezoelectric actuator 2, the gap between the diaphragm 17 and the valve seat 16e can be adjusted, and the fluid flow rate can be adjusted.

As described above, in the present embodiment, it is possible to improve the sealing performance of the diaphragm 17 while maintaining the stem 8 guiding function of the conventional bonnet 10 (see FIG. 7).

(Second embodiment)
In the second embodiment, the inner bonnet 11 in the first embodiment holds the stem 8 axially displaceably via an O-ring 14 in place of the resin sleeve. form.
As shown in FIG. 3, similarly to the first embodiment, the diaphragm placement portion 16d is formed as a bottomed hole-shaped recess having a screw formed on the inner periphery, and the inner periphery of the diaphragm placement portion 16d is provided with an outer periphery. A substantially cylindrical inner bonnet 11 having a threaded portion is screwed in, and the lower end presses the pressing adapter 18 to fix the diaphragm 17 .

However, a resin sleeve is not provided on the inner circumference of the inner bonnet 11, and the outer circumference of the O-ring 14 fitted in the circumferential groove 8d provided on the outer circumference of the stem 8 is brought into contact with the inner circumference of the inner bonnet 11. ing.
The configuration and operation of the second embodiment other than this part are the same as those of the first embodiment, so the description is omitted.
The structure of this embodiment can also improve the sealing performance of the diaphragm 17 while maintaining the stem 8 guiding function of the conventional bonnet.

In each of the above-described embodiments, the inner peripheral portion of the inner bonnet 11 has a structure in which the stem is axially displaceable via the resin sleeve 15 or the O-ring 14, but the present application is not limited thereto. Instead, it may be configured to be displaceably held by a known appropriate mechanism.
In the first embodiment, the outer circumference of the resin sleeve 15 is fitted to the inner circumference of the inner bonnet 11 to hold the stem 8 axially displaceable. It may be configured such that it is fitted to the outer periphery and integrally held on the inner periphery of the inner bonnet 11 so as to be displaceable in the axial direction.

Next, the flow rate control device of the present invention will be explained.
FIG. 4 is a schematic cross-sectional view of a flow control device according to an embodiment of the present invention, showing a pressure-type flow control device 20 incorporating the diaphragm valve 1 described above.
In FIG. 4, a cover that covers the entire flow control device 20 and a board for feedback control are actually present, but are not shown for convenience of explanation.
In addition to the components of the diaphragm valve 1 described above, the flow control device 20 has a downstream block 25, a pressure detector 22, an orifice 21, a pressure detector 26, and flow paths 16c and 25a.

Inside the valve body 16 , an orifice 21 (a gasket-type orifice in this embodiment) is provided in the flow path 16 b on the downstream side of the diaphragm 17 . An upstream pressure detector 22 for detecting pressure is provided in the middle of the flow path 16b on the upstream side of the orifice 21 via a flow path 16c.
The downstream block 25 is connected to the valve body 16 by bolts, has a downstream flow path 25a communicating with the flow path 16b on the downstream side of the valve body 16, and detects the pressure in the downstream flow path 25a. pressure detector 26 is provided.
A controller (not shown) controls the opening and closing of the diaphragm valve 1 by PID control based on the detected values of the pressure detectors 22 and 26 .

The present invention further improves the sealing performance of the diaphragm 17, thereby reducing the risk of fluid leakage.

Next, the fluid control device of the present invention will be explained.
FIG. 5 is a schematic perspective view of a fluid control device according to one embodiment of the present invention.
The fluid control device shown in FIG. 5 is provided with metal base plates BS arranged along width directions W1 and W2 and extending in longitudinal directions G1 and G2. W1 indicates the front side, W2 indicates the rear side, G1 indicates the upstream side, and G2 indicates the downstream side. Various fluid devices 991A to 991E are installed on the base plate BS via a plurality of flow path blocks 992, and a plurality of flow path blocks 992 have a flow path (not shown) through which fluid flows from the upstream side G1 to the downstream side G2. Each road is formed.

Here, the term “fluid device” refers to a device used in a fluid control device for controlling the flow of fluid, comprising a body defining fluid flow paths, and having at least two flow paths opening on the surface of the body. It is a device with B. Specifically, an on-off valve (two-way valve) 991A, a regulator 991B, a pressure gauge 991C, an on-off valve (three-way valve) 991D, a mass flow controller 991E, etc. are included, but are not limited to these. The introduction pipe 993 is connected to the upstream side port of the flow path (not shown).

The present invention can be applied to various diaphragm valves such as the on-off valves 991A and 991D, the regulator 991B and the mass flow controller 991E.

Next, the semiconductor manufacturing apparatus of the present invention will be explained.
FIG. 6 is a block diagram of a semiconductor manufacturing apparatus according to one embodiment of the present invention.
A semiconductor manufacturing apparatus 980 shown in FIG. 6 is an apparatus for executing a semiconductor manufacturing process by an atomic layer deposition method (ALD), 981 is a process gas supply source, 982 is a gas box (fluid control 983 is a tank, 984 is an open/close valve, 985 is a controller, 986 is a processing chamber, and 987 is an exhaust pump.

The present invention is applicable to the gas box 982 described above and the fluid equipment and opening/closing valve 984 that constitute the gas box 982 .

In addition, this invention is not limited to embodiment mentioned above. Those skilled in the art can make various additions, modifications, etc. within the scope of the present invention. For example, in the above application example, the case of use in a semiconductor manufacturing process by the ALD method was exemplified, but the present invention is not limited to this, and for example, the atomic layer etching method (ALE: Atomic Layer Etching method), etc. , can be applied to any object that requires precise flow control.

Reference Signs List 1: Diaphragm valve 2: Piezoelectric actuator 2a: Tip end 2b: Base end 2c: Case 3: Support plate 4: Pressing member 5: Displacement transmission member 6: Upper connecting member 7: Adjusting screw 8: Stem 9: Spring 10: Bonnet 10a: Guide hole 11: Inner bonnet 12: Actuator 13: Bolt 14: O-ring 15: Sleeve 16: Valve body 16a: Upstream channel 16b: Downstream channel 16d: Diaphragm arrangement part 16e: Valve seat 17: Diaphragm 18 : Presser adapter 19 : Diaphragm presser 20 : Flow controller 21 : Orifice 22 : Pressure detector 25 : Downstream block 25a : Downstream flow path 26 : Pressure detector 980 : Semiconductor manufacturing equipment 981 : Process gas supply source 982 : Gas box 983 : Tank 984 : Open/close valve 985 : Control unit 986 : Processing chamber 987 : Exhaust pumps 991A to 991E : Fluid device 992 : Flow path block 993 : Introduction tube BS : Base plate GI, G2: Longitudinal directions W1, W2: Width direction

Claims (7)

a valve body having a flow channel inside and a diaphragm placement portion provided on the upper surface; a diaphragm placed in the diaphragm placement portion and capable of opening and closing the flow channel and adjusting the degree of opening thereof by elastic deformation; A diaphragm valve comprising: a drive unit attached to a valve body and including an actuator and a stem that is driven by the actuator to elastically deform the diaphragm ; and a support mechanism that is fixed to the valve body and supports the actuator,
The diaphragm placement portion is a recess having a threaded inner peripheral surface,
It further has a substantially cylindrical inner bonnet disposed inside the diaphragm placement portion and screwed to the inner peripheral surface of the diaphragm placement portion , wherein the inner bonnet is separate from the support mechanism and is attached to the end portion of the support mechanism. pressing and fixing the diaphragm, and an inner peripheral portion holding the stem so as to be displaceable in the axial direction. the stem and the actuator are arranged in tandem in this order from the top surface of the valve body in a direction perpendicular to the top surface;
The actuator is configured such that the lower end is positioned in contact with a member of the support mechanism, and the vertical position of the upper end is displaced,
2. The diaphragm valve according to claim 1, wherein the upper end of said actuator and said stem are connected by a displacement transmission member extending around said actuator. 3. The diaphragm valve according to claim 1 , wherein the inner bonnet holds the stem axially displaceably via a resin sleeve. 3. The diaphragm valve according to claim 1 , wherein the inner bonnet holds the stem axially displaceably via an O-ring. A flow control device comprising the diaphragm valve according to any one of claims 1 to 4 . A fluid control device in which a plurality of fluid devices are arranged,
A fluid control device, wherein the plurality of fluid devices includes the diaphragm valve according to any one of claims 1 to 4 or the flow control device according to claim 4. The diaphragm valve according to any one of claims 1 to 4 or the flow control device according to claim 4 is used for controlling the process gas in a semiconductor manufacturing process that requires a process gas treatment in a sealed chamber. , semiconductor manufacturing equipment.

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