Pressure control valve

Abstract

To provide a pressure control valve which is provided below a vacuum chamber in a compact form and perform uniform treatment to a processed object in the vacuum chamber by using a process gas.SOLUTION: A pressure control valve 1 includes: a valve body 50 incorporated in a body 10 in which an inlet side opening 11 connected to a vacuum chamber D1 from below and an outlet side opening 12 connected to a vacuum pump P are disposed facing each other; and a valve body drive mechanism 60 which moves the valve body 50 along a center line C of the inlet side opening 11 to a closed position where the valve body 50 closes the inlet side opening 11 and an open position.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a pressure control valve, and particularly to a pressure control valve used in the exhaust system of a vacuum chamber.

Background Art

[0002] Conventionally, as a pressure control valve used in the exhaust system of a vacuum chamber of a semiconductor manufacturing apparatus, one provided below the vacuum chamber is known.

[0003] For example, Patent Document 1 describes a slide valve including a housing having a flow path, a slide plate disposed in the housing and moving perpendicular to the flow path axis between a closed position blocking the flow of the flow path and an open position allowing the flow, and a seal ring surrounding the flow path and engaging with the slide plate in the closed position and spaced apart from the slide plate in the open position. Such a slide valve can be installed below the vacuum chamber while suppressing the dimension in the height direction to be small because the body of the valve is thin.

[0004] And Patent Document 2 describes a vacuum control valve including a valve opening defining an opening axis, having a valve seat provided with a first sealing surface, and having a valve disk having a second sealing surface corresponding to the first sealing surface, the second sealing surface being connected to the valve disk, and the valve disk being adjustable from an open position where the valve disk and the valve seat exist in a manner not contacting each other to a closed position where the second sealing surface of the valve disk is pressed against the first sealing surface by a seal therebetween. Such a vacuum control valve can make the flow of the process gas in the vacuum chamber uniform.

Prior Art Documents

Patent Documents

[0005] [[ID=�4]]

Patent Document 1

[0006] However, the slide valve described in Patent Document 1 involves sliding a slide plate horizontally relative to the valve opening. When used at a small opening, the opening of the valve takes on a crescent shape, causing uneven flow of process gas within the vacuum chamber. As a result, uniform processing of the workpiece within the vacuum chamber using process gas becomes impossible.

[0007] Furthermore, the vacuum control valve described in Patent Document 2 has the problem of requiring a large installation space in the height direction because it is necessary to provide connecting piping that connects the vacuum chamber and the valve body in the vertical direction so that the valve disc can move up and down outside the valve body.

[0008] The present invention was developed to solve the problems of the past, and its objective is to provide a pressure control valve that can be compactly installed below a vacuum chamber and that can perform uniform processing using a process gas on the object to be processed inside the vacuum chamber. [Means for solving the problem]

[0009] To achieve the above objective, the invention according to claim 1 includes a valve body housed in a body having an inlet opening connected to a vacuum chamber from below and an outlet opening connected to a vacuum pump, which are arranged opposite each other, and a valve body drive mechanism that moves the valve body between a closed position and an open position relative to the inlet opening along the centerline of the inlet opening. , an inlet-side connecting flange forming a first chamber contact surface that abuts against the bottom surface of the vacuum chamber, a seat ring that is detachably attached to the upper end surface of the inlet-side opening of the body and forms a second chamber contact surface that abuts against the bottom surface of the vacuum chamber when attached to this upper end surface, and has a valve body contact surface that protrudes inward in diameter of the inlet-side opening so that the outer peripheral edge of the valve body can abut against it, and a body lifting mechanism that adjusts the height position of the body so that the upper end surface of the body can be separated from the bottom surface of the vacuum chamber It is a pressure control valve equipped with [a specific feature].

[0010] The invention according to claim 2 is a pressure control valve in which the valve body drive mechanism comprises a drive source provided outside the body, a stem rotation shaft connected to the drive source outside the body and rotatably introduced inside the body, and an action conversion unit having a stem connection part that connects the stem rotation shaft and the valve body, and converts the rotational motion by the drive source into movement motion of the valve body to the closed position and the open position.

[0011] The invention according to claim 3 is a pressure control valve in which the valve body drive mechanism comprises a drive source provided outside the body, a tilting stem connected to the drive source outside the body and introduced into the body so as to be tiltable, and an action conversion unit having a stem connection part that connects the tilting stem and the valve body, and converts the rotational motion by the drive source into movement motion of the valve body to the closed position and the open position.

[0012] The invention according to claim 4 is a pressure control valve in which the operation conversion unit is capable of holding the valve body in the closed position when the supply of driving force is stopped.

[0014] Claim 5 The invention relating to this is a pressure control valve in which the seat ring has an external sealing material provided on the second chamber contact surface and a valve seat sealing material provided on the valve body contact surface.

[0015] Claim 6 The invention relating to this invention is characterized in that the second chamber contact surface has an inwardly convex stepped shape that protrudes upward compared to the first chamber contact surface. [Effects of the Invention]

[0016] According to the invention of claim 1, a valve body is housed in a body having an inlet opening connected to the vacuum chamber from below and an outlet opening connected to a vacuum pump, and a valve body drive mechanism moves the valve body between a closed position and an open position relative to the inlet opening along the centerline of the inlet opening. As a result, the valve body is installed using the space within the vacuum chamber effectively, and the process gas in the vacuum chamber is exhausted through the central region of the inlet opening, forming a uniform flow of process gas towards the inlet opening. Therefore, it can be compactly installed below the vacuum chamber, and moreover, uniform processing using process gas can be applied to the object to be processed in the vacuum chamber. Furthermore, according to the invention of claim 1, the invention comprises an inlet-side connecting flange having a first chamber contact surface that abuts against the bottom surface of the vacuum chamber, a seat ring that is detachably attached to the upper end surface of the inlet-side opening of the body and, when attached to this upper end surface, has a second chamber contact surface that abuts against the bottom surface of the vacuum chamber, and a valve body contact surface having a portion that protrudes inward in diameter of the inlet-side opening so that the outer peripheral edge of the valve body can abut against it, and a body lifting mechanism that adjusts the height position of the body so that the upper end surface of the body can be separated from the bottom surface of the vacuum chamber. In this way, when fixing the body below the vacuum chamber, the seat ring is interposed between the bottom surface of the vacuum chamber and the body, and the body is fixed to the bottom surface of the vacuum chamber by the inlet-side connecting flange. When performing maintenance on the seat ring or valve body, the body is lifted using a body lifting mechanism to separate the body from the bottom surface of the vacuum chamber, thereby detaching the seat ring from the upper end surface on the inlet side of the body. Therefore, according to the invention of claim 1, the body can be easily attached to the bottom surface of the vacuum chamber without connecting piping, the position of the body can be easily adjusted relative to the vacuum chamber, and as a result, the pressure control valve can be easily installed, and furthermore, maintenance of the seat ring and valve body can be easily performed with the body separated from the vacuum chamber.

[0017] According to the invention of claim 2, the valve drive mechanism includes a drive source provided outside the body, a stem rotating shaft connected to the drive source outside the body and rotatably introduced inside the body, and an action conversion unit having a stem connecting part that connects the stem rotating shaft and the valve body, which converts the rotational motion by the drive source into movement motion of the valve body to the closed and open positions. As a result, the driving force from the drive source provided outside the body is transmitted to the inside of the body via the stem rotating shaft and converted into power to move the valve body to the closed and open positions. Therefore, the airtightness inside the body can be ensured with a simple configuration such as an O-ring provided around the stem rotating shaft, and as a result, the airtightness inside the body can be ensured at low cost.

[0018] According to the invention according to claim 3, the valve body drive mechanism has a drive source provided outside the body, a tilting stem that is connected to the drive source outside the body and introduced into the body in a tiltable manner, and a stem connection portion that connects the tilting stem and the valve body, and has an operation conversion portion that converts the rotational operation by the drive source into the movement operation of the valve body to the closed position and the open position. Thus, the driving force by the drive source provided outside the body is transmitted to the inside of the body via the stem rotation axis and converted into the power to move the valve body to the closed position and the open position. Therefore, the airtightness inside the body can be ensured with a simple structure such as a bellows provided around the tilting stem, and as a result, the airtightness inside the body can be ensured at low cost.

[0019] According to the invention according to claim 4, since the operation conversion portion can hold the valve body in the closed position in the state where the supply of the driving force is stopped, even when a load to open acts from the state where the valve is closed in the state where the supply of the driving force to the valve body drive mechanism is stopped, the state where the valve is closed is maintained, and the energy consumption in the state where the valve is closed can be suppressed.

[0021] Claim 5 According to the invention according to claim, since an external sealing material is provided on the second chamber contact surface of the seat ring and a valve seat sealing material is provided on the valve body contact surface, the body is fixed to the bottom surface of the vacuum chamber via the external sealing material of the seat ring, and the valve body closes the inlet side opening via the valve seat seal of the seat ring. Therefore, the airtightness of the connection portion between the vacuum chamber and the body and the airtightness inside the vacuum chamber when the valve body is in the closed position can be improved via the external sealing material and the valve seat seal provided on the seat ring.

[0022] Claim 6According to the invention related thereto, since the second chamber abutting surface has an inner convex stepped shape protruding upward compared to the first chamber abutting surface, a recess is provided on the bottom surface of the vacuum chamber into which the upward protruding portion by the second chamber abutting surface is inserted. When the body is attached to the vacuum chamber, the sheet ring is embedded in the recess of the vacuum chamber, so that the installation dimension in the height direction can be made compact. Moreover, the airtightness of the attachment portion of the body to the vacuum chamber can be improved. Furthermore, the positioning when attaching the body to the vacuum chamber becomes easy and the assembling property of the body with respect to the vacuum chamber can be improved.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram showing a usage mode of a pressure control valve according to Embodiment 1 of the present invention. [Figure 2] It is a perspective view of a pressure control valve. [Figure 3] It is a top view of a pressure control valve. [Figure 4] It is a view of the inside of the body of the pressure control valve as seen from the axial direction of the stem rotation axis. [Figure 5] It is a perspective view showing the periphery of the operation conversion part of the pressure control valve in the valve closed state. [Figure 6] It is a perspective view showing the periphery of the operation conversion part of the pressure control valve in the valve open state. [Figure 7] It is a diagram showing a state where the height position of the body of the pressure control valve is adjusted using a body lifting mechanism. [Figure 8] It is a perspective view of a pressure control valve according to Embodiment 2 of the present invention. [Figure 9] It is a perspective view showing the periphery of the operation conversion part of the pressure control valve. [Figure 10] It is a top view of a pressure control valve. [Figure 11] It is a side view of a pressure control valve.

Modes for Carrying Out the Invention

[0024] The embodiments of this invention will be described in detail below.

[0025] The pressure control valve 1 according to Embodiment 1 will be described in detail with reference to Figures 1-7. Figure 1 is a diagram showing how the pressure control valve 1 is used. Figure 2 is a perspective view of the pressure control valve 1. Figure 3 is a top view of the pressure control valve 1. Figure 4 is a view of the inside of the body 10 of the pressure control valve 1 from the axial direction of the stem rotation axis 62a. Figure 5 is a perspective view showing the area around the operation conversion unit 62 of the pressure control valve 1 in the valve closed state. Figure 6 is a perspective view showing the area around the operation conversion unit 62 of the pressure control valve 1 in the valve open state. Figure 7 is a diagram showing the state in which the height position of the body 10 of the pressure control valve 1 is adjusted using the body lifting mechanism 70. In Figure 1, the valve body 50 in the open position is shown by a dashed line. Furthermore, in Figures 2-7, some of the components are shown in cross-section and with hidden lines.

[0026] The pressure control valve 1 according to Embodiment 1 of the present invention is used in the exhaust system of the vacuum chamber D1 of a semiconductor manufacturing apparatus D. As shown in Figure 1, the vacuum chamber D1 of the semiconductor manufacturing apparatus 100 applies a process gas to the surface of the object to be processed M, such as a silicon wafer, which is held on the stage.

[0027] The pressure control valve 1 has one end, which serves as the inlet for the process gas, connected to the vacuum chamber D1, and the other end, which serves as the outlet for the process gas, connected to a vacuum pump P such as a turbomolecular pump.

[0028] This pressure control valve 1 comprises a body 10 that constitutes the main body, an inlet-side connecting flange 20 and an outlet-side connecting flange 30 integrally formed on the body 10, a seat ring 40 detachably provided on the body 10, a valve body 50 built into the body 10, a valve body driving mechanism 60 that moves the valve body 50 between a closed position and an open position, and a body lifting mechanism 70 that adjusts the position of the body 10 so that the upper end surface 10a of the body 10 can be separated from the bottom surface D2 of the vacuum chamber D1.

[0029] (Regarding Body 10) Body 10 is made of aluminum, for example, and has a roughly rectangular shape in its horizontal cross-section, making it easy to machine. However, the material and shape of body 10 are not limited to these, and other materials and shapes may be used.

[0030] This body 10 has an inlet opening 11 that connects to the vacuum chamber D1 from below and an outlet opening 12 that connects to the vacuum pump P, arranged opposite each other, and has a space inside that connects the inlet opening 11 and the outlet opening 12 to serve as a flow path for process gas. More specifically, the body 10 has a circumferential wall 13 with a circular inlet opening 11 at its upper end and a circular outlet opening 12 at its lower end. The internal space formed by this circumferential wall 13 serves as a flow path for process gas, which flows in through the inlet opening 11 via a vacuum pump P and out through the outlet opening 12. In this embodiment 1, the opening diameter on the inlet side is determined by the seat ring 40 attached to the upper end surface 10a of the body 10. In this embodiment 1, the opening 40a of the seat ring 40 and the outlet side opening 12 are circular in shape with the same diameter, but the shape and diameter are not limited to this and other shapes and diameters may be used.

[0031] (Regarding the inlet-side connection flange 20) The inlet-side connecting flange 20 is integrally provided with the body 10 so as to protrude horizontally outward from the circumferential side wall 13 of the body 10. This inlet-side connecting flange 20 forms a first chamber contact surface 21 that abuts against the bottom surface D2 of the vacuum chamber D1. In this embodiment 1, the inlet-side connecting flange 20 has a roughly rectangular shape in its horizontal cross-section, corresponding to the body 10. This inlet-side connecting flange 20 has bolt holes 22, and bolts BT are passed through these bolt holes 22 to fix it to the bottom surface D2 of the vacuum chamber D1. The bolt holes 22 are provided at each of the four corners of the inlet-side connecting flange 20. Of these four bolt holes 22, the two diagonally opposite bolt holes 22 are used to screw in the stud bolts 71 described later, and the remaining two diagonally opposite bolt holes 22 are used to screw in bolts BT.

[0032] (Regarding the outlet side connection flange 30) The outlet-side connecting flange 30 is provided integrally with the lower part of the body 10, with its width reduced horizontally inward from the circumferential side wall 13 of the body 10. This outlet-side connecting flange 30 has a cylindrical shape with a flow path formed inside that communicates from the outlet-side opening 12 of the body 10 toward the lower end opening. The lower end surface of this outlet-side connecting flange 30 is the surface that connects to the vacuum pump P.

[0033] (Regarding the seat ring 40) The seat ring 40 is detachably attached to the upper end surface 10a (hereinafter simply referred to as the "upper end surface") on the inlet side opening 11 of the body 10. The seat ring 40 is fixed to the upper end surface 10a, for example, using a bolt BT with a fall prevention mechanism. The seat ring 40 forms a second chamber contact surface 41 that contacts the bottom surface D2 of the vacuum chamber D1 when attached to the upper end surface 10a, and also has a valve body contact surface 42 that partially protrudes inward in diameter of the inlet side opening 11 so that the outer peripheral edge 51a of the valve body 50 can contact it. Here, as shown in Figure 2, the second chamber contact surface 41 formed by the seat ring 40 protrudes upward compared to the first chamber contact surface 21 formed by the inlet-side connecting flange 20. Therefore, the pressure control valve 1 has a stepped shape in which the second chamber contact surface 41 protrudes upward compared to the first chamber contact surface 21.

[0034] Furthermore, the seat ring 40 is provided with an external sealing material 43 on the second chamber contact surface 41 and a valve seat sealing material 44 on the valve body contact surface 42.

[0035] The valve seat seal material 44 is provided on the lower side of the seat ring 40, that is, on the side opposite to the upper side of the seat ring 40 which faces the vacuum chamber D1, so that it is less susceptible to corrosion from corrosive gases and products from the vacuum chamber D1. It is more preferable to use a material that is resistant to corrosive gases and their products for the valve seat sealing material 44.

[0036] (Regarding valve body 50) The valve body 50 includes a valve body 51 that contacts the seat ring 40 to close the inlet opening 11, and a connecting part 52 that is detachably provided with respect to the valve body 51 and connects to the connecting link 62d of the operation conversion unit 62, which will be described later. The valve body 51 is roughly disc-shaped, and its outer peripheral edge 51a is in contact with the seat ring 40, which serves as the valve seat, or more specifically, with the valve seat sealing material 44 provided on the seat ring 40.

[0037] The connecting portion 52 is fixed to the valve body 51 by a bolt BT or the like that has a function to prevent it from falling off, and has a pair of connecting pieces 52a that are connected to one end of a pair of connecting links 62d of the operating conversion portion 62. Each connecting piece 52a is connected to a link pin PN that passes through the inner ring of a pair of bearings B provided at one end of the connecting link 62d.

[0038] In this way, the valve body 50 is detachably attached to a connecting part 52 that connects to the operation conversion part 62, so that the valve body 51, which wears down by contacting the seat ring 40 that forms the valve seat, can be easily removed from inside the body 10 to the outside during maintenance.

[0039] (Regarding the valve drive mechanism 60) The valve body drive mechanism 60 includes a drive source 61 and an motion conversion unit 62 that converts the rotational motion by the drive source 61 into movement motion of the valve body 50 to the closed position and the open position.

[0040] The drive source 61 is implemented, for example, by a stepping motor and is installed outside the body 10. More specifically, the drive source 61 is fixed to the outer surface of the circumferential side wall 13 of the body 10. In this embodiment 1, a stepping motor is used as the drive source 61, but other drive sources may be used instead of a stepping motor. For example, a servo motor may be used.

[0041] The motion conversion unit 62 includes a stem rotation shaft 62a that is connected to the drive source 61 outside the body 10 and rotatably introduced inside the body 10, a stem connection part 62b that connects the stem rotation shaft 62a and the valve body 50, and a lifting guide 62e that guides the vertical movement of the valve body 50.

[0042] The stem rotation shaft 62a is connected to the drive source 61 outside the body 10 and is also rotatably introduced inside the body 10. More specifically, the stem rotation shaft 62a has one end connected to the output shaft 61a of the drive source 61 outside the body 10, with its axis aligned, and the other end is rotatably introduced inside the body 10. Furthermore, a stem insertion hole 13a is formed in the circumferential side wall 13 of the body 10, through which the stem rotation shaft 62a can be inserted, and the stem rotation shaft 62a is inserted from the outside to the inside of the body 10 through this stem insertion hole 13a. As shown in Figure 3, the stem rotation shaft 62a, which extends from the outside to the inside of the body 10, is rotatably supported by multiple bearings B arranged along the axial direction.

[0043] Furthermore, an O-ring S1 is provided around the stem insertion hole 13a, ensuring airtightness around the stem insertion hole 13a, which forms the connection point between the inside and outside of the body 10.

[0044] The stem connection section 62b is a two-bar linkage having an arc-shaped link 62c and a connecting link 62d that connect the stem rotation shaft 62a and the valve body 50 in order to transmit power from the stem rotation shaft 62a to the valve body 50.

[0045] The arc-shaped link 62c has one end connected to the stem rotation axis 62a and the other end connected to the connecting link 62d. The end of the arc-shaped link 62c that connects to the connecting link 62d is provided with a bearing B and is rotatably connected to the connecting link 62d. More specifically, a pair of bearings B are provided at the end of the connecting link 62d that connects to the arc-moving link 62c, and the end of the arc-moving link 62c is connected to a link pin PN that passes through the inner ring of this pair of bearings B. For bearing B, it is preferable to use, for example, a SUS440C milled ball bearing or an UltraClean® bearing.

[0046] Furthermore, the connecting link 62d is also provided with a pair of bearings B at the end that connects to the connecting piece 52a of the valve body 50, and the connecting piece 52a of the valve body 50 is connected to a link pin PN that passes through the inner ring of this pair of bearings B. Therefore, the stem connection section 62b, which is composed of the arc-shaped link 62c and the connecting link 62d, can distribute the load applied to the valve body 50 to the four bearings B, and a small bearing can be used. In this type of stem connection portion 62b, when the valve body 50 is in the open position, the arc-shaped link 62c and the connecting link 62d are folded compactly so that they wrap around the stem rotation axis 62a, as shown in Figure 6. This allows the open position of the valve body 50 built into the body 10 to be set closer to the stem rotation axis 62a. On the other hand, when the valve body 50 is in the open position, the arc-shaped link 62c and the connecting link 62d are extended from their folded state, as shown in Figure 5. Therefore, the distance between the stem rotation shaft 62a inside the body 10 and the inlet-side opening 11 of the body 10 can be effectively utilized as the travel distance associated with the opening and closing of the valve body 50. In other words, the stem connection portion 62b allows the valve body 50 to be compactly housed within the body 10 while maximizing the travel distance associated with the opening and closing of the valve body 50, and as a result, the valve opening degree can be set to a large value.

[0047] In this embodiment 1, the horizontal space, that is, the axial space of the stem rotation axis 62a, is effectively utilized to provide the stem connection portion 62b at two locations along the axial direction of the stem rotation axis 62a. In this way, by providing the stem connection portions 62b at two locations along the axial direction of the stem rotation axis 62a, the load applied to the stem connection portions 62b through the valve body 50 can be distributed and received by each stem connection portion 62b.

[0048] The lifting guide 62e guides the valve body 50, which is powered from the stem rotation shaft 62a via the stem connection part 62b, to move up and down along the center line C (see Figure 4) of the inlet opening 11 to the closed position and the open position. This lifting guide 62e is rod-shaped with its upper end connected to the valve body 50, more specifically to the connecting portion 52 of the valve body 50, and is fixed inside the body 10 so as to be retractable. Furthermore, two lifting guides 62e are provided. The two lifting guides 62e are positioned between two stem connection parts 62b located along the stem rotation axis 62a, and are arranged opposite each other in a direction perpendicular to the stem rotation axis 62a. Furthermore, to ensure maintenance-free operation, it is recommended to use grease-free bearings for the lifting guide 62e.

[0049] The valve drive mechanism 60 and valve body 50 constitute a toggle mechanism consisting of two links and one slider. In other words, the arc-moving link 62c and the connecting link 62d function as the two links of the toggle mechanism, and the valve body 50, guided by the lifting guide 62e, functions as the slider of the toggle mechanism. Therefore, as shown in Figure 4, the two opposing centers of rotation of the arc-shaped link 62c and the connecting link 62d are kept in a state where they are approximately aligned in a straight line. In other words, the valve body 50 is kept in the closed position.

[0050] Furthermore, in this embodiment, a cylindrical flow straightening cover 63 is provided around the valve body 50 of the valve body drive mechanism 60, more specifically, the portion where the valve body 50 moves up and down guided by the lifting guide 62e, and this flow straightening cover 63 is used to suppress the leakage of process gas into the stem connection portion 62b.

[0051] (Regarding the body lifting mechanism 70) The body lifting mechanism 70 includes the above-mentioned inlet-side connecting flange 20, a stud bolt 71 screwed into the bolt hole 22 of the inlet-side connecting flange 20, and a nut 72 that is screwed onto the stud bolt 71. The stud bolt 71 is screwed into the bolt hole 22 of the inlet-side connecting flange 20, and the portion that is inserted upward from the bolt hole 22 of the inlet-side connecting flange 20 is screwed into the bolt hole on the bottom surface of the vacuum chamber D1. Furthermore, the pressure control valve 1 is integrally mounted on the lower part of the body 10 with the outlet-side connecting flange 30 narrowed horizontally inward from the circumferential side wall 13 of the body 10, so that the outlet-side connecting flange 30 does not interfere with the stud bolt 71 screwed into the inlet-side connecting flange 20.

[0052] The nut 72 is screwed onto the stud bolt 71 from a position below the inlet-side connecting flange 20. Therefore, when the nut 72 is tightened, the body 10 rises along the stud bolt 71, and the upper end surface of the inlet-side connecting flange 20 comes into contact with the bottom surface D2 of the vacuum chamber D1, thereby fixing the body 10 to the vacuum chamber D1. On the other hand, when the nut 72 is loosened, the body 10 descends along the stud bolt 71, and the body 10 moves away from the bottom surface D2 of the vacuum chamber D1.

[0053] (Regarding the opening and closing operation of valve body 50) The opening and closing operation of the valve body 50 will be described below. The drive source 61 is connected to a control device (not shown) via a driver and is driven based on control signals from the control device. In other words, when a control signal from the control device to move the pressure control valve 1 from closed to open is input to the drive source 61 via the driver, the drive source 61 rotates the stem rotation shaft 62a by a predetermined rotation angle to move the valve body 50 inside the body 10 from the closed position to the open position. In this embodiment 1, the rotation angle required to change the opening and closing position of the valve body 50 is adjusted to be approximately 120 degrees.

[0054] When the valve body 50 is in the closed position, as shown in Figure 4, the rotation center of the stem rotation axis 62a and the two corresponding rotation centers of the two-bar linkage formed by the arc-moving link 62c and the connecting link 62d are aligned approximately in a straight line in the vertical direction. Therefore, the pressure control valve 1, through its operation as a toggle mechanism consisting of the valve body drive mechanism 60 and the valve body 50, is capable of holding the valve body 50 in the closed position even when the power supply from the drive source 61 is stopped, that is, when the drive power is turned OFF. In other words, even when the pressure control valve 1 has the valve body 50 in the closed position and the drive power is turned off, and a back pressure load due to differential pressure is applied to the valve body 50, the valve body 50 is held in the closed position.

[0055] When the valve body 50 (see Figures 4 and 5) in the closed position moves to the open position, the two-bar linkage, composed of the arc-shaped link 62c and the connecting link 62d, is displaced by the rotation of the stem rotation shaft 62a, causing the stem rotation shaft 62a to be positioned in the recess of the V-shaped connecting link 62d, resulting in the state shown in Figure 6. Here, the end of the arc-shaped movable link 62c that connects to the connecting link 62d moves downward along the arc trajectory, and in conjunction with the movement of this arc-shaped movable link 62c, the connecting link 62d and the valve body 50 connected to the connecting link 62d move downward. In this way, the arc-shaped link 62c and the connecting link 62d are folded compactly so that they wrap around the stem rotation axis 62a. Therefore, the valve body 50 moves to the maximum extent possible within the body 10, from a closed position near the inlet opening 11 of the body 10 to an open position near the stem rotation axis 62a, increasing the valve opening and, as a result, increasing the vacuum pumping speed. Furthermore, the valve body 50 is guided to descend linearly along the center line C of the inlet opening 11 by the lifting guide 62e, moving from a closed position where its outer peripheral edge 51a abuts against the seat ring 40 to an open position where it is separated downward from the seat ring 40. As the valve body 50 moves along the center line C of the inlet opening 11 (see Figure 4), the process gas in the vacuum chamber D1 is uniformly dispersed with the center of the inlet opening 11 as the center of flow and discharged into the body 10, as shown in Figure 1, resulting in a uniform flow of process gas within the vacuum chamber D1.

[0056] Next, the installation and maintenance procedures for the pressure control valve 1 will be explained using Figure 7. (Regarding the installation procedure for pressure control valve 1) First, we will explain the procedure for installing pressure control valve 1. The worker inserts stud bolts 71 into two diagonally opposite bolt holes 22 on the inlet-side connection flange 20 of the body 10, either with the vacuum pump P assembled to the outlet-side connection flange 30 or before the vacuum pump P is assembled to the outlet-side connection flange 30, and then screws the upper end of each stud bolt 71 into the corresponding bolt hole on the bottom surface D2 of the vacuum chamber D1.

[0057] Then, the worker tightens the nuts 72 that are passed through the lower end of each stud bolt 71. This causes the body 10 to rise toward the vacuum chamber D1, and the upper end surface of the inlet-side connecting flange 20 to come into contact with the bottom surface D2 of the vacuum chamber D1.

[0058] Subsequently, the worker screws bolts BT into the remaining two bolt holes 22 located diagonally opposite each other on the inlet-side connecting flange 20 and fastens them into the corresponding bolt holes on the bottom surface D2 of the vacuum chamber D1, thereby completing the installation of the pressure control valve 1.

[0059] (Regarding the maintenance procedure for pressure control valve 1) Next, we will describe the maintenance procedure for pressure control valve 1. This section describes how to maintain the pressure control valve 1, more specifically, how to replace or clean the consumable seat ring 40 or the valve body 50. First, the worker loosens the two bolts BT other than the stud bolt 71 screwed into the bolt hole 22 of the inlet-side connecting flange 20 to release the fastening. Next, the nuts 72 screwed onto the two stud bolts 71 are loosened. As a result, the body 10 of the pressure control valve 1 descends along the stud bolts 71 so as to gradually move away from the vacuum chamber D1, creating a gap between the upper end surface 10a of the body 10, more specifically, the second chamber contact surface 41 of the seat ring 40 and the bottom surface D2 of the vacuum chamber D1. This gap is adjusted to facilitate the removal of the seat ring 40 from the upper end surface 10a of the body 10, or the removal of the valve body 50 built into the body 10.

[0060] Then, the worker releases the bolt BT that secures the seat ring 40 to the upper end surface 10a of the body 10, and detaches the seat ring 40 from the body 10. Furthermore, when removing the valve body 50 built into the body 10, the worker releases the bolt BT that secures the valve body 51 to the connecting part 52, and removes the valve body 51 from the connecting part 52. In this way, the connecting portion 52 that connects to the drive source 61 remains inside the body 10, while only the valve body 51 that contacts and wears down the seat ring 40, which serves as the valve seat, can be removed from inside the body 10.

[0061] According to this embodiment 1, the pressure control valve 1 includes a valve body 50 housed in a body 10 having an inlet opening 11 connected to the vacuum chamber D1 from below and an outlet opening 12 connected to the vacuum pump P facing each other, and a valve body drive mechanism 60 that moves the valve body 50 between a closed position and an open position relative to the inlet opening 11 along the center line C of the inlet opening 11. As a result, the valve body 50 is installed making effective use of the space within the vacuum chamber D1, and the process gas in the vacuum chamber D1 is exhausted through the central region of the inlet opening 11, forming a uniform flow of process gas in the vacuum chamber D1 towards the inlet opening 11. Therefore, it can be compactly installed below the vacuum chamber D1, and moreover, uniform processing using process gas can be applied to the object to be processed M in the vacuum chamber D1.

[0062] Furthermore, according to this embodiment 1, the pressure control valve 1 has a valve body drive mechanism 60 which includes a drive source 61 provided outside the body 10, a stem rotating shaft 62a connected to the drive source 61 outside the body 10 and rotatably introduced inside the body 10, and a stem connecting part 62b that connects the stem rotating shaft 62a and the valve body 50, and an operation conversion part 62 which converts the rotational movement by the drive source 61 into movement of the valve body 50 to the closed and open positions. As a result, the driving force from the drive source 61 provided outside the body 10 is transmitted to the inside of the body 10 via the stem rotating shaft 62a and converted into power to move the valve body 50 to the closed and open positions. Therefore, the airtightness inside the body 10 can be ensured with a simple configuration such as an O-ring S1 provided around the stem rotating shaft 62a, and as a result, the airtightness inside the body 10 can be ensured at low cost.

[0063] Furthermore, according to this embodiment 1, the pressure control valve 1 is configured such that the operation conversion unit 62 can hold the valve body 50 in the closed position when the supply of driving force is stopped. As a result, even when the supply of driving force to the valve body drive mechanism 60 is stopped while the valve is closed, the valve remains closed against the load that would open the valve, thus reducing energy consumption when the valve is closed.

[0064] Furthermore, the pressure control valve 1 according to Embodiment 1 of the present invention includes an inlet-side connecting flange 20 having a first chamber contact surface 21 that abuts against the bottom surface D2 of the vacuum chamber D1, a seat ring 40 that is detachably attached to the upper end surface 10a of the body 10 and has a second chamber contact surface 41 that abuts against the bottom surface D2 of the vacuum chamber D1 when attached to the upper end surface 10a, and a valve body contact surface 42 that protrudes inward in diameter of the inlet-side opening 11 so that the outer peripheral edge 51a of the valve body 50 can abut against it, and a body lifting mechanism that adjusts the height position of the body 10 so that the upper end surface 10a of the body 10 can be separated from the bottom surface D2 of the vacuum chamber D1. As a result, when fixing the body 10 below the vacuum chamber D1, the seat ring 40 is interposed between the bottom surface D2 of the vacuum chamber D1 and the body 10, and the body 10 is fixed to the bottom surface D2 of the vacuum chamber D1 by the inlet-side connecting flange 20. When performing maintenance on the seat ring 40 and valve body 50, the body lifting mechanism 70 is used to separate the body 10 from the bottom surface D2 of the vacuum chamber D1, thereby detaching the seat ring 40 from the upper end surface 10a of the body 10. Therefore, the body 10 can be easily attached to the bottom surface D2 of the vacuum chamber D1 without connecting piping, and the position of the body 10 relative to the vacuum chamber D1 can be easily adjusted. As a result, the pressure control valve 1 can be easily installed, and furthermore, maintenance of the seat ring 40 and valve body 50 can be easily performed with the body 10 separated from the vacuum chamber D1.

[0065] Furthermore, according to this embodiment 1, the pressure control valve 1 has an external sealing material 43 on the seat ring 40's second chamber contact surface 41 and a valve seat sealing material 44 on the valve body contact surface 42. As a result, the body 10 is fixed to the vacuum chamber D1 via the external sealing material 43 of the seat ring 40, and the valve body 50 closes the inlet side opening 11 via the valve seat sealing material 44 of the seat ring 40. Therefore, the airtightness of the connection between the vacuum chamber D1 and the body 10, and the airtightness inside the vacuum chamber D1 when the valve body 50 is in the closed position can be improved via the external sealing material 43 and valve seat sealing material 44 provided on the seat ring 40.

[0066] Furthermore, according to this embodiment 1, the pressure control valve 1 has a stepped shape in which the second chamber contact surface 41 protrudes upward compared to the first chamber contact surface 21, and a recess is provided in the bottom surface D2 of the vacuum chamber D1 into which the upper protruding portion of the second chamber contact surface 41 fits. When the body 10 is attached to the vacuum chamber D1, the seat ring 40 is embedded in the recess of the vacuum chamber D1, so that the height dimension of the installation can be made more compact, the airtightness of the attachment portion of the body 10 to the vacuum chamber D1 can be improved, and the positioning when attaching the body 10 to the vacuum chamber D1 can be made easier, improving the ease of assembling the body 10 to the vacuum chamber D1.

[0067] The pressure control valve 2 according to Embodiment 2 will be described in detail with reference to Figures 8-11. Figure 8 is a perspective view of a pressure control valve 2 according to Embodiment 2 of the present invention. Figure 9 is a perspective view showing the area around the operating conversion unit 82 of the pressure control valve 2. Figure 10 is a top view of the pressure control valve 2. Figure 11 is a side view of the pressure control valve 2. In Figures 8-11, some of the components are shown in cross-sectional views and indicated using hidden lines. The pressure control valve 2 according to this embodiment 2 differs from the pressure control valve 1 of embodiment 1 in that the configuration of the valve drive mechanism 80 that moves the valve body 50 between the closed position and the open position is different. In Embodiment 2, the description of the same configuration as in Embodiment 1 will be omitted.

[0068] The pressure control valve 2 according to Embodiment 2 of the present invention comprises a body 10 constituting the main body, an inlet-side connecting flange 20 and an outlet-side connecting flange 30 integrally formed on the body 10, a seat ring 40 detachably provided on the body 10, a valve body 50 built into the body 10, a valve body driving mechanism 80 that moves the valve body 50 between a closed position and an open position, and a body lifting mechanism 70 that adjusts the position of the body 10 so that the upper end surface 10a of the body 10 can be separated from the bottom surface D2 of the vacuum chamber D1.

[0069] The valve body drive mechanism 80 includes a drive source 81 provided outside the body 10, a tilting stem 82a connected to the drive source 81 outside the body 10 and introduced into the body 10 so as to be tiltable, and an action conversion unit 82 having a stem connection part 82b that connects the tilting stem 82a and the valve body 50, and converts the rotational motion by the drive source 81 into movement motion of the valve body 50 to the closed position and the open position.

[0070] The drive source 81 is implemented, for example, by a stepping motor and is located outside the body 10. In this embodiment 2, a stepping motor is used as the drive source, but other drive sources may be used instead of a stepping motor. For example, a servo motor may be used.

[0071] The motion conversion unit 82 includes a rotating disk 82d connected to the output shaft 81a of the drive source 81 with its center aligned, an arc-shaped cam roller 82e provided at an eccentric position on the rotating disk 82d, a drive arm 82f with one end connected to the arc-shaped cam roller 82e, a tilting stem 82a provided to extend continuously in front of the drive arm 82f, a tilting pivot point 82h connecting the tilting stem 82a and the drive arm 82f so that the tilting stem 82a can tilt, a stem connection part 82b connecting the tilting stem 82a and the valve body 50, and a lifting guide 82m that guides the vertical movement of the valve body 50.

[0072] The arc-shaped cam roller 82e moves along an arc-shaped trajectory as the turntable 82d rotates. This arc-shaped cam roller 82e has a rotatable roller in the portion that is inserted into the slider hole 82g, which will be described later.

[0073] The drive arm 82f has an elongated slider hole 82g at one end into which an arc-shaped cam roller 82e is inserted. Power is transmitted from the drive source 81 to the drive arm 82f via the slider hole 82g as the arc-shaped cam roller 82e moves along the arc trajectory.

[0074] The tilting stem 82a constitutes the other end of a seesaw structure where one end is supported by the tilting pivot point 82h, and the other end is supported by the drive arm 82f. Such a tilting stem 82a is designed to tilt around the tilting pivot point 82h in conjunction with the movement of the drive arm 82f.

[0075] The tilting pivot point 82h is located outside the body 10. This tilting pivot point 82h includes a stem connecting portion 82i that connects the drive arm 82f and the tilting stem 82a, a pair of rotating shaft portions 82n provided on the stem connecting portion 82i parallel to the output shaft 81a of the drive source 81, and a pair of bearing portions 82o that support the pair of rotating shaft portions 82n.

[0076] The stem connecting portion 82i includes a connecting wall 82k provided perpendicular to the extending direction of the tilting stem 82a so as to fix the rear end of the tilting stem 82a and the tip of the drive arm 82f with a fixing member such as a bolt, and a pair of shaft mounting walls 82l that protrude from both ends of the connecting wall 82k in the extending direction of the tilting stem 82a and are each provided with a pair of rotating shaft portions 82n.

[0077] The bearing portion 82o is realized by bearings provided opposite a pair of shaft mounting walls 82l, and supports a pair of rotating shaft portions 82n.

[0078] As shown in Figure 11, the center of the rotating shaft portion 82n is located on a line passing through the center of the pair of connecting links 82c that are connected to the tip of the arc-shaped cam roller 82e and the tilting stem 82a, which are inserted into the slider hole 82g of the drive arm 82f. Therefore, a continuous member extending from the rear end of the drive arm 82f to the tip of the tilting stem 82a is capable of moving in a seesaw-like manner with the tilting pivot point 82h as the pivot point. In other words, the tilting stem 82a is supported so as to be able to tilt by the tilting pivot point 82h.

[0079] The hole through which the tilting stem 82a is inserted into the body 10 is sealed by a metal bellows S2. More specifically, as shown in Figure 10, a portion with an enlarged diameter is provided as a connection point between the rear end of the tilting stem 82a and the stem connecting portion 82i, and one end of the bellows S2 is connected to this portion, while the other end of the bellows S2 is connected to the circumferential wall 13 of the body 10 so as to surround the insertion hole. In this second embodiment, the bellows S2 is connected to the tilting stem 82a and the body 10 by welding.

[0080] In this embodiment 2, the pair of rotating shaft portions 82n are provided at approximately the center position of the bellows S2, which extends from one end to the other end along the extending direction of the tilting stem 82a. In other words, the pair of rotating shafts 82n are positioned closer to the body 10 than the rear end of the tilting stem 82a. Therefore, the range of the tilt angle of the tilting stem 82a can be kept small, enabling highly durable airtight performance by the bellows S2.

[0081] The stem connection portion 82b has a connecting link 82c, and a pair of bearings B are provided at the end of this connecting link 82c that connects to the tip of the tilting stem 82a, and the tip of the tilting stem 82a is connected to a link pin PN that passes through the inner ring of this pair of bearings B. Furthermore, the connecting link 82c has one end that connects to the tilting stem 82a and the other end that connects to the connecting piece 52a of the valve body 50. A pair of bearings B are provided at the part of the link that connects to the connecting piece 52a of the valve body 50, and the connecting piece 52a of the valve body 50 is connected to a link pin PN that passes through the inner ring of this pair of bearings B. Therefore, the stem connection section 82b, which is formed by the connecting link 82c, can distribute the load applied to the valve body 50 to the four bearings B, and a small bearing can be used.

[0082] (Regarding the opening and closing operation of valve body 50) The opening and closing operation of the valve body 50 will be described below. The drive source 81 is connected to a control device (not shown) via a driver and is driven based on control signals from the control device. In other words, when a control signal from the control device to move the pressure control valve 2 from closed to open is input to the drive source 81 via the driver, the drive source 81 rotates the turntable 82d at a predetermined rotation angle so as to move the valve body 50 from the closed position to the open position within the body 10.

[0083] When the tilting stem 82a is tilted upward and the valve body 50 is in the closed position, if a load (reverse load) is applied to the valve body 50 in a downward direction in Figure 11, as shown by the solid line in Figure 11, the load is transmitted so that the continuous member extending from the tip of the tilting stem 82a to the rear end of the drive arm 82f moves in a seesaw-like manner with the tilting fulcrum 82h as the pivot point. In this way, when the load transmitted from the tip of the tilting stem 82a to the drive arm 82f acts on the arc-moving cam roller 82e via the slider hole 82g, a force (arrow A in Figure 11) acting on the arc-moving cam roller 82e is directed toward the center of the output shaft 81a of the drive source 81. Therefore, no force acts on the rotating disk 82d around the output shaft 81a by the arc-shaped cam roller 82e, and as a result, the tilting stem 82a is held at an inclination that closes the valve body 50. In other words, the pressure control valve 2 is designed to maintain the valve body 50 in the closed position even when power is not supplied from the drive source 81, that is, when the drive power supply is turned OFF.

[0084] When the valve body 50 is in the closed position, the rotation of the turntable 82d causes the arc-shaped cam roller 82e to move in an arc shape to the position shown by the dashed line in Figure 11, causing the tilting stem 82a to be displaced to a downward-tilted position. Here, the connecting link 82c moves downward along the arc trajectory, and in conjunction with the movement of the connecting link 82c, the valve body 50 connected to the connecting link 82c moves downward. Furthermore, the valve body 50 is guided vertically by the lifting guide 82m and moves along the centerline of the inlet opening 11 from a closed position where its outer peripheral edge 51a abuts against the seat ring 40 to an open position where it is separated downward from the seat ring 40.

[0085] According to this second embodiment, the pressure control valve 2 includes a valve body 50 housed in a body 10 having an inlet opening 11 connected to the vacuum chamber D1 from below and an outlet opening 12 connected to the vacuum pump P facing each other, and a valve body drive mechanism 80 that moves the valve body 50 between a closed position and an open position relative to the inlet opening 11 along the center line C of the inlet opening 11. As a result, the valve body 50 is installed making effective use of the space within the vacuum chamber D1, and the process gas in the vacuum chamber D1 is exhausted through the central region of the inlet opening 11, forming a uniform flow of process gas in the vacuum chamber D1 towards the inlet opening 11. Therefore, similar to the pressure control valve 1 of the first embodiment, it can be compactly installed below the vacuum chamber D1, and moreover, uniform processing using process gas can be applied to the object to be processed M in the vacuum chamber D1.

[0086] Furthermore, according to this second embodiment, the pressure control valve 2 has a valve body drive mechanism 80 which includes a drive source 81 provided outside the body 10, a tilting stem 82a connected to the drive source 81 outside the body 10 and introduced into the body 10 so as to be tiltable, and a movement conversion unit 82 which has a stem connection part 82b connecting the tilting stem 82a and the valve body 50 and converts the rotational movement by the drive source 81 into movement of the valve body 50 to the closed position and the open position. As a result, the driving force from the drive source 81 provided outside the body 10 is transmitted to the inside of the body 10 via the tilting stem 82a and converted into power to move the valve body 50 to the closed position and the open position. Therefore, the airtightness of the body 10 can be ensured with a simple configuration such as a bellows S2 provided around the tilting stem 82a, and as a result, the airtightness inside the body 10 can be ensured at low cost.

[0087] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention as described in the claims of the present invention.

[0088] In the above embodiment, the motion conversion units 62 and 82 are exemplified as being composed of a stem rotation shaft 62a, or a tilting stem 82a, and stem connection units 62b and 82b connected thereto. However, the system is not limited to this configuration, and other configurations are acceptable as long as the rotational motion by the drive sources 61 and 81 can be converted into movement of the valve body 50 to the closed and open positions. For example, the stem connection unit 62b may be composed of a linkage mechanism with two or more sections.

[0089] Furthermore, in the above embodiment, the valve body 50 was held in the closed position by the link configuration of the motion conversion units 62 and 82, but the invention is not limited to this, and for example, the valve body 50 may be held in the closed position by utilizing the electromagnetic brake of the stepping motor that serves as the drive source. [Explanation of symbols]

[0090] 1, 2 Pressure control valves 10 Body 10a Upper end surface 11 Entrance side opening 12 Outlet side opening 13 Peripheral wall 13a Stem insertion hole 20 Inlet side connection flange 21 First chamber contact surface 22 bolt holes 30 Outlet side connection flange 40 Seat Rings 40a opening 41 Second chamber contact surface 42 Valve body contact surface 43 External sealing material 44 Valve seat seal material 50 valve bodies 51 Valve body 51a Outer edge 52 Connecting part 52a Connecting piece 60, 80 Valve body drive mechanism 70 Body lifting mechanism 71 Stud bolts 72 nuts 61, 81 Power source 61a, 81a output shaft 62, 82 Operation conversion unit 62a Stem rotation axis 82a Tilting stem 62b, 82b Stem connection 62c Arc-shaped linkage 62d Connection Link 63 Rectifier cover 82c connection link 82d Rotating disc 82e Arc-shaped cam roller 82f Drive Arm 82g Slider hole 82h Tilt fulcrum 82i Stem connection part 82k connecting wall 82l axis installation wall 62e, 82m Lifting Guide 82n Rotating shaft section 82. Bearing section S1 O-ring S2 Bellows D Semiconductor manufacturing equipment D1 Vacuum Chamber D2 Bottom P Vacuum pump M - Object to be processed

Claims

1. A valve body is housed in a body with an inlet opening that connects to the vacuum chamber from below and an outlet opening that connects to the vacuum pump, arranged opposite each other. A valve drive mechanism moves the valve body along the center line of the inlet opening to a closed position and an open position relative to the inlet opening, An inlet-side connecting flange having a first chamber contact surface that contacts the bottom surface of the vacuum chamber, A seat ring is detachably attached to the upper end surface of the inlet-side opening of the body, and when attached to the upper end surface, it forms a second chamber contact surface that contacts the bottom surface of the vacuum chamber, and has a valve body contact surface that protrudes inward in diameter of the inlet-side opening so that the outer peripheral edge of the valve body can contact it, A pressure control valve characterized by comprising a body lifting mechanism that adjusts the height position of the body so that the upper end surface of the body can be freely separated from the bottom surface of the vacuum chamber.

2. The valve drive mechanism comprises a drive source provided outside the body, The pressure control valve according to claim 1, further comprising: a stem rotating shaft connected to the drive source outside the body and rotatably introduced inside the body; and an action conversion unit having a stem connecting portion that connects the stem rotating shaft and the valve body, thereby converting the rotational motion by the drive source into movement motion of the valve body to the closed and open positions.

3. The valve drive mechanism comprises a drive source provided outside the body, A pressure control valve according to claim 1, comprising: a tilting stem connected to the drive source outside the body and introduced into the body so as to be tiltable; and an motion conversion unit having a stem connection portion that connects the tilting stem and the valve body, which converts the rotational motion by the drive source into movement motion of the valve body to the closed position and the open position.

4. The pressure control valve according to claim 2 or 3, wherein the operation conversion unit is capable of holding the valve body in the closed position when the supply of driving force is stopped.

5. The pressure control valve according to any one of claims 1 to 4, wherein the seat ring is provided with an external sealing material on the contact surface with the second chamber and a valve seat sealing material on the contact surface with the valve body.

6. The pressure control valve according to any one of claims 1 to 5, wherein the second chamber contact surface has an inwardly convex stepped shape that protrudes upward compared to the first chamber contact surface.

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