Gate valve for vacuum processing container

Abstract

By eliminating the use of a valve body to create a space-saving structure, the vacuum processing device can be miniaturized. Furthermore, the double-ring seal structure protects the sealing surface, and the valve body is equipped with a forced detachment mechanism operated by bolts, providing a gate valve that operates stably for long periods even in harsh dusty environments and offers excellent maintainability. [Solution] The gate valve 1 of the present invention is a gate valve 1 for a vacuum processing container that can be opened and closed while maintaining airtightness of an opening from which a processing nozzle 100 formed in the vacuum processing container 10 protrudes, and comprises a plate-shaped valve body 20 disposed inside the vacuum processing container 10 and having a through hole on one end and an annular seal formed on the other end that does not have a through hole, a shaft 30 that penetrates the vacuum processing container 10 and whose lower end is connected to the center of the valve body, a bolt 70 with a push-down mechanism that is screw-connected to the upper end of the shaft 30 and moves the shaft axially back and forth by rotational operation, and a handle 50 connected to the shaft 30 via an adapter 45 and that rotates the valve body 20 by 180 degrees, wherein the annular seal has a main seal 21 that airtightly seals the space between the opening and the valve body 20, and a dust seal 22 that is attached to the outer circumference of the main seal 21 and prevents contaminants from adhering to the inner wall surface of the vacuum processing container 10 that the main seal 21 contacts.

Description

Technical Field

[0001] The present invention relates to a partition valve used in a vacuum processing vessel of a vacuum processing apparatus, and more particularly to a partition valve of a vacuum processing apparatus that can cope with a narrow space and reduce the operation stop time associated with maintenance.

Background Art

[0002] In vacuum processing apparatuses such as semiconductor manufacturing apparatuses and vacuum film forming apparatuses, nozzles such as electron guns and plasma guns, or sensors and probes arranged in the vacuum processing vessel (hereinafter referred to as processing nozzles) are subject to aging, deposition of deposits, and deterioration due to chemical reactions associated with repeated use. For this reason, periodic replacement is necessary. However, in order to maintain the vacuum state of the entire apparatus (to avoid vacuum breakage) when replacing the nozzles, a partition valve is provided in the vacuum processing apparatus.

[0003] The partition valve disclosed in Patent Document 1 has a configuration including a dedicated housing (valve box) that houses the valve body and its drive unit inside. Thereby, the opening and closing of the vacuum path are performed by sliding the valve body inside the housing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] [[ID=�8]] However, in the conventional partition valve as described in Patent Document ۱, since the valve box for housing and holding the valve body is assembled on the atmospheric side of the apparatus, it protrudes greatly outward from the apparatus and the occupied space increases, resulting in the problem that the entire apparatus becomes larger.

[0006] Furthermore, nozzles such as electron guns and plasma guns exposed in the vacuum processing chamber require frequent maintenance due to the accumulation of deposits and chemical reactions during use. In environments where fine dust is generated, such as vacuum spraying equipment, dust (contamination) tends to accumulate in the sealing parts of the gate valves. This could lead to a loss of airtightness, requiring the equipment to be disassembled for cleaning and parts replacement, potentially resulting in a significant amount of labor-intensive maintenance work.

[0007] This invention has been made in view of the above problems, and enables miniaturization of the vacuum processing device by using a space-saving structure that does not use a valve body, and provides a gate valve that operates stably for a long period of time even in harsh dusty environments and has excellent maintainability by providing protection of the sealing surface with a double ring seal structure and a forced detachment mechanism for the valve body by bolt operation. [Means for solving the problem]

[0008] The gate valve of the present invention is a gate valve for a vacuum processing container that can be opened and closed while maintaining airtightness of an opening from which a processing nozzle formed in the vacuum processing container protrudes, and comprises a plate-shaped valve body disposed inside the vacuum processing container and having an annular seal formed thereon which has a through hole on one end and an annular seal which does not have a through hole on the other end, a shaft that penetrates the vacuum processing container and whose lower end is connected to the center of the valve body, a bolt with a push-down mechanism that is screw-connected to the upper end of the shaft and moves the shaft axially back and forth by rotational operation, and a handle that is connected to the shaft via an adapter and rotates the valve body, and the annular seal is characterized by having a main seal that airtightly seals the space between the opening and the valve body, and a dust seal that is attached to the outer circumference of the main seal and prevents contaminants from adhering to the inner wall surface of the vacuum processing container that the main seal contacts. [Effects of the Invention]

[0009] According to this invention, a space-saving structure that does not use a valve body enables miniaturization of the vacuum processing device, and by providing protection of the sealing surface with a double-ring seal structure and a forced detachment mechanism for the valve body by bolt operation, it is possible to provide a gate valve that operates stably for a long period of time even in harsh dusty environments and has excellent maintainability.

[0010] Furthermore, by providing a valve body with a two-position structure (open and closed) and a double ring seal consisting of a main seal and a dust seal at both positions, the main seal contact surface is always protected by the dust seal regardless of whether the valve body is in the open or closed position. This prevents contaminants such as dust generated during processing from adhering to the seal contact surface, thereby extending the maintenance cycle of the vacuum processing equipment.

[0011] Furthermore, the inclusion of a forced separation mechanism that pushes the shaft downward in the axial direction through contact between the bolt and the bolt stopper ensures that even if the main seal and dust seal (O-ring) become adhered to the inner wall of the vacuum chamber due to heat, the valve body can be reliably and easily separated by manual operation. [Brief explanation of the drawing]

[0012] [Figure 1] The diagram shows the external appearance of a gate valve according to an embodiment of the present invention, where (a) is a front view, (b) is a top view, (c) is a side view, and (d) is a bottom view. [Figure 2] This figure shows the external appearance of a gate valve according to an embodiment of the present invention, where (a) is a cross-sectional view AA of Figure 1(b) and (b) is a cross-sectional view BB of Figure 1(b). [Figure 3] The diagram shows the external appearance of a gate valve according to an embodiment of the present invention. (a) is an explanatory diagram showing the state in which the main seal and dust seal are separated from the vacuum processing container in the AA cross-sectional view of Figure 1(b). (b) is an explanatory diagram showing the state in which the main seal and dust seal are separated from the inner wall of the vacuum processing chamber in the BB cross-sectional view of Figure 1(b). [Figure 4] This is an exploded perspective view of a gate valve according to an embodiment of the present invention. [Modes for carrying out the invention]

[0013] The gate valve 1 of this invention will be described below based on an embodiment. Note that the dimensions and dimensional ratios shown in the drawings do not necessarily correspond to the actual dimensions and dimensional ratios. Also, unless otherwise specified, for convenience, directions such as up and down are indicated based on the orientation of the gate valve 1 shown in Figure 1(a). Repetitive explanations will be omitted as appropriate, and the same reference numerals may be assigned to the same components.

[0014] Figure 1 shows the external appearance of a gate valve 1 according to an embodiment of the present invention, where Figure 1(a) is a front view, Figure 1(b) is a top view, Figure 1(c) is a side view, and Figure 1(d) is a bottom view. The vacuum processing chamber apparatus according to this embodiment is provided with a processing nozzle 100, a vacuum processing container 10, and a gate valve 1 equipped with a valve body 20 that abuts against or separates from the inner wall of the vacuum processing container 10.

[0015] The processing nozzle 100 is housed in a roughly rectangular housing. In a device configuration with a vacuum processing container 10 as the boundary, the processing nozzle 100 is fixed to the atmospheric side and is configured as a functional component for supplying processing liquid or gas into the vacuum processing container 10 or for detecting the state inside the vacuum processing chamber. The tip of its probe or electron gun protrudes into the vacuum processing container 10 when in operation.

[0016] The vacuum processing container 10 is a stationary wall that separates the inside and outside of the vacuum processing chamber device. This vacuum processing container 10 physically separates the drive system above from the valve body below.

[0017] As shown in Figure 1(d), the valve body 20 is located on the vacuum side of the vacuum processing container 10 (in the figure, inside the vacuum processing container 10). The valve body 20 is provided with a vent hole 26 for adjusting air stagnation and pressure fluctuations caused by contact with or separation from the inner wall of the vacuum processing container 10, and a filter 25 for preventing foreign matter from entering through the vent hole 26.

[0018] The vent hole 26 functions as a pressure adjustment path for equalizing the pressure of the annular sealed space formed between the main seal 21 and the dust seal 22, which will be described later, when the valve body 20 abuts against the vacuum processing chamber 10. Specifically, when evacuating the processing chamber to a vacuum, if air at atmospheric pressure is trapped between the double seals, the space becomes a relatively high-pressure pocket, and the remaining air leaks into the vacuum processing chamber 10 through the main seal 21. In this embodiment, by quickly releasing the pressure in the sealed space through the vent hole 26, it prevents a decrease in the degree of vacuum in the vacuum processing chamber 10 and plays a role in stabilizing the vacuum performance. Further, the filter 25 attached to the vent hole 26 physically blocks foreign substances such as contaminants from entering the processing chamber while allowing the flow of gas associated with this pressure adjustment.

[0019] FIG. 2 is a cross-sectional view showing the partition valve 1 according to an embodiment of the present invention. FIG. 2(a) is a cross-sectional view taken along the line A - A of FIG. 1(b), and FIG. 2(b) is a cross-sectional view taken along the line B - B of FIG. 1(b). In the vacuum processing chamber 10 according to this embodiment, an opening for a protruding portion such as a probe of the processing nozzle 100 is formed. The valve body 20 is formed with an open portion having a through hole corresponding to the opening and a closed portion having no through hole in a bilaterally symmetric shape. The valve body 20 is provided with a main seal 21 for sealing between the inner wall of the vacuum processing chamber 10 and the valve body 20, and a dust seal 22 attached to the outer peripheral side of the main seal 21 for preventing the adhesion of contaminants to the main seal contact surface of the vacuum processing chamber 10 with which the main seal 21 adheres, at the peripheries of the above-described open portion and closed portion. The position where the open portion of the valve body 20 abuts against the opening of the vacuum processing chamber 10 and is airtightly sealed is the open position, and the position where the closed portion of the valve body 20 abuts against the opening of the vacuum processing chamber 10 and is airtightly sealed is the closed position.

[0020] The valve body 20 is an oval flat plate member, and annular seal grooves for accommodating the main seal 21 and the dust seal 22 are formed in a double layer at the portion that abuts against the inner wall surface of the vacuum processing chamber 10 of the valve body 20. The valve body 20 switches between the open position and the closed position by rotating, and also abuts against or separates from the inner wall of the vacuum processing chamber 10 by the axial forward and backward movement of a shaft 30, which will be described later.

[0021] As shown in FIG. 2(b), the opening is a circular hole with a stepped portion for fitting formed in the vacuum processing container 10 into which a substantially rectangular housing accommodating the processing nozzle 100 is fitted. The opening penetrates in the thickness direction of the vacuum processing container 10 and is an opening for inserting a probe or the like.

[0022] As shown in FIG. 2(b), the opening is a circular through-hole, and the annular main seal 21 and dust seal 22 formed on the valve body 20 adhere to the inner wall of the vacuum processing container 10 so as to surround the periphery of the through-hole.

[0023] The through-hole of the valve body 20 is formed in the center of the opening part and has an inner diameter substantially equal to that of the opening formed in the vacuum processing container 10. When the valve body 20 is in the open position, this through-hole coincides with the opening in the central axis and overlaps to form a space for the protruding part such as the probe of the processing nozzle 100.

[0024] The closing part of the valve body 20 is a region defined on the other end side in the longitudinal direction of the valve body 20. There is no through-hole in the center of the closing part, and it is configured as a flat shielding surface. As shown in FIG. 2(b) representing the closed position, when the closing part abuts against the opening of the vacuum processing container 10, the opening is physically blocked and vacuum-sealed.

[0025] The main seal 21 is an annular seal member (O-ring) made of an elastic material and is mounted in the inner seal grooves of the annular seal grooves formed in the opening part and the closing part. As shown in FIGS. 2(a) and 2(b), when the valve body 20 abuts against the vacuum processing container 10, the main seal 21 adheres to the wall surface and is compressed and deformed around the opening, functioning as a seal for maintaining airtightness between the inside and outside of the processing chamber.

[0026] The dust seal 22 is an annular sealing member with a larger diameter than the main seal 21, arranged concentrically around the outer circumference of the main seal 21 at regular intervals, on the same plane as the main seal 21. The dust seal 22 adheres to the vacuum processing container 10 further outward than the main seal contact surface to which the main seal 21 adheres. This physically blocks fine contaminants and dust from entering the contact surface side of the main seal 21, and functions as a protective seal that prevents a decrease in the sealing performance of the main seal 21.

[0027] Figure 3(a) is an explanatory diagram showing the state in which the main seal 21 and dust seal 22 are separated from the vacuum processing container 10 in the AA cross-sectional view of Figure 1(b), and Figure 3(b) is an explanatory diagram showing the state in which the main seal 21 and dust seal 22 are separated from the vacuum processing container 10 in the BB cross-sectional view of Figure 1(b). Figure 4 is an exploded perspective view of a gate valve 1 according to an embodiment of the present invention. The gate valve 1 according to this embodiment is provided with a pair of pillars 60, a top bar 65 spanning the upper ends thereof, a shaft 30 that penetrates the vacuum processing container 10 and whose lower end is connected to the center of the valve body 20, a handle adapter 45 and a handle 50 that transmit rotational force to the rotating shaft 30, a bolt 70 that is screw-connected to the upper end of the shaft 30 and moves the shaft 30 axially by rotational operation, and a bolt stopper 66 positioned opposite the head of the bolt 70.

[0028] The pillars 60 are a pair of columnar members erected vertically from the outer surface (atmospheric pressure side) of the vacuum processing container 10. As shown in Figure 4, the two pillars are positioned symmetrically on either side of the rotation axis 30, and by fixing and holding the top bar 65 at their upper ends, they function as supports that bear the reaction force when the bolts 70 are operated.

[0029] The top bar 65 is a plate-shaped support member that spans horizontally between the upper ends of a pair of pillars 60. A through hole for inserting a bolt 70 is formed in its center. The top bar 65 serves as a seating surface to receive the tightening force of the bolt 70 and also ensures the structural rigidity of the entire drive unit.

[0030] The rotating shaft 30 is a rod-shaped shaft member that airtightly penetrates the vacuum processing container 10 and extends from the atmospheric pressure side to the vacuum pressure side. Its lower end (vacuum pressure side end) is connected to the central part of the valve body 20, and an internal thread is formed at its upper end (atmospheric pressure side end) for engaging with the bolt 70. As described above, the valve body 20 can be switched between the open position and the closed position by rotating around the shaft 30. The valve body 20 also moves in contact with or away from the vacuum processing container 10 by its axial (perpendicular) movement caused by the rotation of the shaft 30.

[0031] The handle adapter 45 is a substantially cylindrical member attached to the atmospheric pressure side exposed portion of the rotating shaft 30, and has an intermediary structure that reliably transmits the rotational torque from the handle 50 to the rotating shaft 30.

[0032] The handle 50 is a lever member for manual operation, connected to the rotating shaft 30 via a handle adapter 45. By rotating the handle 50 horizontally, the operator can rotate the rotating shaft 30 and the valve body 20 between the open and closed positions (for example, within a range of 180 degrees).

[0033] The bolt 70 is a member for moving forward and backward, which is screw-connected to the female thread formed at the upper end of the rotating shaft 30. The shaft of the bolt 70 passes through the through hole in the top bar 65, and its head is located on the upper surface side of the top bar 65. When the bolt 70 is rotated (loosened), the shaft 30 is pushed out axially (downward in the figure) by the bolt stopper 66 (described later) and the feeding action of the screw, and the valve body 20 is separated from the vacuum processing container 10, as shown in Figures 3(a) and 3(b).

[0034] As shown in Figure 4, the bolt stopper 66 is a bracket-shaped member fixed to the upper surface of the top bar 65 so as to straddle the head of the bolt 70. The inner surface of the bolt stopper 66 faces the top surface of the bolt 70's head, physically restricting the upward axial movement of the bolt 70. This ensures that the rotational force loosening the bolt 70 is reliably converted into a downward force (or upward force) on the rotating shaft 30.

[0035] As shown in Figures 3(a) and 3(b), the operation of the bolt 70 pushes the rotating shaft 30 downward, causing the main seal 21 and dust seal 22 of the valve body 20 to separate from the vacuum processing container 10 (creating a clearance). In this state, by rotating the handle 50, the valve body 20 can be rotated smoothly without the sealing material rubbing against the wall surface.

[0036] On the other hand, when transitioning to the tightly sealed state shown in Figures 2(a) and 2(b), the operator rotates the bolt 70 in the tightening direction (opposite to the direction of separation). Since the downward movement of the head of the bolt 70 is restricted by the upper surface of the top bar 65, the rotational force of the bolt 70 is converted into a thrust that pulls up the rotating shaft 30 via the threaded joint.

[0037] As the rotating shaft 30 moves axially upward (towards atmospheric pressure), the valve body 20, fixed to the lower end of the shaft, rises vertically toward the vacuum processing container 10. As a result, the main seal 21 and dust seal 22, which are concentrically positioned on the open or closed portion of the valve body 20, simultaneously and uniformly come into close contact with the sealing contact surface of the vacuum processing container 10. Since the main seal 21 and dust seal 22 are elastic, they undergo compression deformation, with the inner main seal 21 maintaining airtightness between the vacuum processing container 10 and the valve body 20, and the outer dust seal 22 preventing contamination from adhering to the main seal contact surface. In this way, a double seal structure for vacuum sealing and contamination prevention is simultaneously and reliably achieved by tightening the bolt 70 in only one direction.

[0038] The handle 50 is fitted with a positioning pin 55 that defines the rotational position of the valve body 20 and allows the operator to visually confirm the raising and lowering state of the valve body 20. The positioning pin 55 is a cylindrical projection that protrudes vertically upward (towards the top bar 65) from the top surface of the handle 50. Correspondingly, the top bar 65 has pin holes with a diameter that allows the positioning pin 55 to be fitted at two positions 180 degrees opposite each other, corresponding to the "open position" and "closed position" of the valve body 20.

[0039] The handle 50, shaft 30, and valve body 20 are connected so that they move forward and backward integrally in the axial direction. In the "closed state" shown in Figure 2, as the rotating shaft 30 rises due to the tightening of the bolt 70, the handle 50 also rises. This causes the positioning pin 55 to be fully inserted into the pin hole of the top bar 65, physically locking the rotation of the handle 50 and bringing the valve body 20 into contact with the vacuum processing container 10. On the other hand, in the "detached state" shown in Figure 3, as the rotating shaft 30 descends due to the loosening of the bolt 70, the handle 50 also descends. This causes the positioning pin 55 to escape downward from the pin hole, releasing the lock on the handle 50.

[0040] When the operator rotates the handle 50, visually confirming that the positioning pin 55 has completely disengaged from the pin hole serves not merely as confirmation of unlocking, but also plays the following important technical roles. Firstly, it serves as an indicator of the completion of separation of the valve body 20 within the vacuum chamber. The separation state between the valve body 20 and the wall surface, which is obscured by the opaque vacuum processing container 10 and cannot be directly seen from the outside, can be accurately determined by the exposed distance of the positioning pin 55 on the atmospheric side. The state in which the positioning pin 55 has completely disengaged from the hole ensures that the main seal 21 and dust seal 22 of the valve body 20 have separated from the vacuum processing container 10 with sufficient clearance.

[0041] If the handle 50 is rotated while the positioning pin 55 remains inside, the valve body 20 and the vacuum processing container 10 will move relative to each other while remaining in close proximity, which may cause wear and damage to the sealing material due to friction against the wall surface. By confirming that the pin has been completely removed before starting rotation, the integrity of the sealing material is maintained and deterioration of airtightness is prevented. Furthermore, forcing rotation while the positioning pin 55 is not completely removed can lead to excessive lateral load on the pin itself, the area around the pin hole in the top bar 65, and the shaft 30. To prevent deformation and damage to these parts and to maintain smooth operation over the long term, confirming that the positioning pin 55 has been removed is a mandatory step in the operation of this device.

[0042] A shaft housing 40 is attached to the vacuum processing container 10 via a seal housing 46 to hold the shaft 30 rotatably and airtightly. Inside the shaft housing 40, a cylindrical bushing 35 is arranged to coaxially support the shaft 30 and guide the smooth rotation and movement of the shaft 30. For airtightness, an end face seal 41 positioned between the end faces of the shaft housing 40 and the seal housing 46 is responsible for airtightness at the stationary part, and a shaft seal 42 that directly slides against the outer circumferential surface of the rotating shaft 30 prevents vacuum leakage during shaft operation. As a result, the rotation and movement of the rotating shaft 30 can be performed with precision while being isolated from the external atmospheric environment.

[0043] As described above, the valve body 20 according to the embodiment of the present invention has a structure that eliminates the valve casing, thereby minimizing protrusion to the outside of the device. Furthermore, since the drive unit can be positioned adjacent to the processing nozzle, etc., it can be installed in a narrow space, contributing to the miniaturization of the vacuum processing device. In addition, the double-ring structure with dust seals 22 in both open and closed positions ensures that the contact surface of the main seal 21 is always protected, preventing the adhesion of contaminants generated during processing and significantly extending the maintenance cycle. Moreover, since it is equipped with a forced release mechanism using bolts 70 and bolt stoppers 66, even if the main seal 21 or dust seal 22 becomes stuck to the vacuum processing container 10 due to the effects of heat, it can be reliably and easily opened by manual operation.

[0044] Next, the operating procedure for the valve body 20 will be described in detail. First, the bolt 70, which is in the fastened state, is rotated in the loosening direction. When the head of the bolt 70 comes into contact with the bolt stopper 66, the rotation shaft 30 is forcibly pushed downward in the axial direction (towards the vacuum side). As a result, the main seal 21 and dust seal 22 of the valve body 20, which were in close contact with the vacuum processing container 10, separate from the wall surface, and the valve body 20 becomes rotatable.

[0045] Next, confirm that the positioning pin 55 on the handle 50 has been completely removed from the pin hole in the top bar 65. In this state, rotate the handle 50 180 degrees horizontally. This rotational movement causes the valve body 20 inside the vacuum chamber to move from the open position to the closed position (or vice versa) via the handle adapter 45 and the rotating shaft 30. In this embodiment, it is possible to visually confirm from the outside whether the valve body 20 is currently in the open or closed position by the direction in which the handle 50 is pointed.

[0046] After rotating the handle 50 180 degrees, the positioning pin 55 is aligned with the other pin hole drilled in the top bar 65, and the bolt 70 is rotated in the tightening direction. The top bar 65 acts as a seating surface to receive the tightening force of the bolt 70, and the rotation shaft 30 is pulled upward in the axial direction (towards the atmosphere). As a result, the valve body 20 comes into contact with the vacuum processing container 10, and the main seal 21 and dust seal 22 come into close contact with the vacuum processing container 10, completing the vacuum sealing and preventing contamination from adhering to the main seal contact surface. [Explanation of Symbols]

[0047] 1. Gate valve 10 Vacuum Processing Vessels 20 valve body 21 Main Seal 22 Dust seal 25 filters 26 Ventilation holes 30 axes 35 Bushing 40-axis housing 41 End face seal 42 Axle seal 45 Handle Adapter 46 Seal Housing 50 handle 55 Positioning pins 60 Pillar 65 Top Bar 66 Bolt stopper 70 volts 100 processing nozzles

Claims

1. A gate valve for a vacuum processing container that allows openings to be opened and closed while maintaining airtightness of the opening from which a processing nozzle formed in the vacuum processing container protrudes, A plate-shaped valve body is disposed inside the vacuum processing container, and has an annular seal formed on one side having a through hole and the other side not having a through hole, A shaft that penetrates the vacuum processing container and whose lower end is connected to the center of the valve body, A bolt screw-connected to the upper end of the shaft and equipped with a push-down mechanism that moves the shaft axially forward and backward by rotational operation, The shaft is connected via an adapter and includes a handle for rotating the valve body, The gate valve for a vacuum processing container is characterized in that the annular seal comprises a main seal that airtightly seals the space between the opening and the valve body, and a dust seal mounted on the outer circumference of the main seal to prevent contamination from adhering to the inner wall surface of the vacuum processing container against which the main seal contacts.

2. A gate valve for a vacuum processing container, characterized in that the open or closed state of the opening can be confirmed by the orientation of the handle.

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