JP6416506B2 - Vacuum gate valve - Google Patents

Description

  The present invention relates to an improvement of a vacuum gate valve that is used, for example, in a processing chamber of a semiconductor device to evacuate various processing chambers, and in particular, while maintaining a sealed state by a valve plate, The present invention relates to the prevention of particle generation due to contact and the enhancement of durability and easy maintenance.

  In the manufacturing process of a semiconductor device, a gate is provided between a processing chamber and a suction pump in order to create a vacuum state in various processing chambers for performing thin film processing by CVD (chemical vapor deposition), processing such as PVD, and PVD. A valve is used. As this vacuum gate valve, in recent years, since it is advantageous in terms of space and can be manufactured relatively easily, a laterally swiveled gate valve that swings the valve plate in the casing in the lateral direction has been widely adopted. Yes.

  In this laterally turning vacuum gate valve, a slight gap is set between the valve plate and the casing in order to ensure smooth swinging of the valve plate in the casing. Therefore, after the valve plate is moved to a position that closes the opening, it is necessary to close the valve plate to the casing in order to eliminate the gap and secure a sealed state.

  In this case, in order to prevent displacement and deformation of the valve plate due to the pressure difference, to securely maintain the sealed state and to prevent damage to the valve plate, the inventors have set the valve plate to the fully closed position with respect to the opening. The position adjusting means further includes a position adjusting means for bringing the valve plate into close contact with the casing at a certain time. The position adjusting means is relative to the rotating body by the rotation of the driving source, the rotating body rotated by the driving source, and the rotating body. A vacuum gate valve has been proposed (see Patent Documents 1 and 2). The vacuum gate valve is characterized by adjusting the position of the valve plate by contacting the valve plate. This technology does not allow the displacement of the valve plate mechanically without contact with the elastic member when the valve plate is in close contact with the casing, but allows the valve plate to swing except when the valve plate is in close contact with the casing. Thus, it can be opened and closed.

  However, in this vacuum gate valve, the elevating body is housed in the casing in close contact with the casing via the O-ring and grease, and slides in the casing. In this case, the O-ring is consumed relatively quickly due to wear, and the vacuum gate valve has heat of 80 ° C. to 120 ° C. due to baking during operation. If the elevating body is repeatedly raised and lowered in a state where the grease is not sufficiently spread, particles may be generated due to contact between the elevating body, the valve plate, and the metal that is the casing material (metal contact). There is. If particles caused by these O-rings, grease, or metal materials are scattered in the processing chamber, the performance of the semiconductor device to be manufactured will be affected, or various measuring instruments such as pressure sensors may be damaged. It can happen.

  For this reason, conventional vacuum gate valves require maintenance such as replenishment of grease and replacement of O-rings in a relatively short period of time. As a result, contact between the lifting body and the casing must be reliably avoided, while at the same time, these machine elements are used in extremely harsh environments, requiring short-term maintenance. Therefore, it is very important to be able to easily perform access and detachment for maintenance.

  Although it is conceivable to raise and lower the elevating body using a magnet as a drive source, in this case, in order to control the elevating according to the magnetic force of the magnet, it is necessary to detect the strength of the magnetic force (magnetic flux density). . In order to detect the magnetic flux density, it is generally considered that the sensor is disposed in a member magnetized by a magnet, but as described above, the members used for these vacuum gate valves are: Since the temperature rises to about 100 ° C., it is necessary to consider heat resistance, and at the same time, if a sensor is installed on a member installed inside the casing, there will be a problem that much maintenance and replacement are required. On the other hand, it is conceivable to install a sensor in the gap part between the magnet and the lifting body to measure the magnetic flux density, but the gap part is a part where collision occurs when attracted by the magnet In addition to being difficult to install, when the vacuum gate valve is attached to the processing chamber, it is a part located on the vacuum side, so it is necessary to consider atmospheric inflow and at the same time normal operation under vacuum There was also a problem that it was difficult to secure.

Japanese Patent No. 4630994 JP 2011-117488 A

  In view of the above problems, the problem to be solved by the present invention is to maintain the sealed state by the valve plate and to suppress the generation of particles due to contact between grease and metal, while having high durability. It is another object of the present invention to provide a vacuum gate valve that can be easily maintained.

As a first means for solving the above-mentioned problems, the present invention provides a valve plate for a vacuum gate valve comprising a casing having an opening and a valve plate that swings in the casing to open and close the opening. valve by but further comprising a position adjusting means for adhering the valve plate to the casing when in the fully closed position with respect to the opening, the position adjusting means, while in close contact with the valve plate by descending in the casing, which increases A lifting body that adjusts the position of the valve plate away from the plate, and a lifting means that lifts and lowers the inside of the casing so that frictional resistance does not occur between the lifting body and the casing. Installed in the casing with a gap between the O-ring and grease without any gap between them. The processing chamber side is kept in a vacuum state even when the lifting body is separated from the valve plate while there is a gap between the lifting body and the casing while the lifting means is lifted and lowered in the casing. The present invention provides a vacuum gate valve characterized in that a sealing O-ring is provided .

The present invention provides, as a second means for solving the above problems, said Te first solution odor, temperature descending means, vacuum, wherein the lifting body thereby lifting without coming into contact with the casing A gate valve is provided.

  According to the present invention, as a third means for solving the above-described problems, in the first or second solving means, the elevating means has an electromagnet that generates a magnetic force by energization and draws the elevating body. The present invention also provides a vacuum gate valve characterized by adjusting the magnetic force generated by an electromagnet by controlling energization to raise and lower the elevating body.

  According to the present invention, as a fourth means for solving the above problem, in the third solving means, the elevating means includes a sensor for detecting the magnetic flux density by the electromagnet, and the magnetic flux density detected by the sensor is adjusted. Accordingly, the present invention provides a vacuum gate valve characterized by controlling energization to an electromagnet and controlling the elevating speed of the elevating body by adjusting the magnetic force.

As a fifth means for solving the above-mentioned problems, the present invention provides a vacuum gate valve having a casing having an opening and a valve plate that swings in the casing to open and close the opening. When the valve is in the fully closed position with respect to the opening, it further comprises a position adjusting means for bringing the valve plate into close contact with the casing. An elevating body that adjusts the position of the valve plate away from the plate, and elevating means that elevates the interior of the casing so that frictional resistance does not occur between the elevating body and the casing. It has an electromagnet that generates a magnetic force and pulls the lifting body, and controls the magnetic force generated by the electromagnet by controlling energization. The elevating body is moved up and down, and the elevating means includes a sensor for detecting the magnetic flux density by the electromagnet, and controls the energization to the electromagnet according to the magnetic flux density detected by the sensor to adjust the magnetic force. The lifting / lowering speed of the lifting / lowering body is controlled, the electromagnet is installed in the casing and is installed inside the adsorbing body that is magnetized by the electromagnet and adsorbs the lifting / lowering body, Provided is a vacuum gate valve which is installed at a position deviated from a gap between an adsorbing body and a lifting body and detects a magnetic flux density by an electromagnet.

  As a sixth means for solving the above-mentioned problems, the present invention is characterized in that, in the fifth solution means, the sensor is installed beside the gap between the adsorbing body and the lifting body. A vacuum gate valve is provided.

  According to the present invention, as a seventh means for solving the above-described problem, in the fifth or sixth solving means, the elevating means has a lower magnetic flux density detected by the sensor so that the magnetic force of the electromagnet is lower. A vacuum gate valve is characterized in that it is judged to be strong and the magnetic force of the electromagnet is judged to be weaker as the magnetic flux density detected by the sensor is higher, and the elevating speed of the elevating body is controlled to a predetermined value according to the magnetic force. It is to provide.

As an eighth means for solving the above-mentioned problems, the present invention provides a vacuum gate valve including a casing having an opening and a valve plate that swings in the casing to open and close the opening. When the valve is in the fully closed position with respect to the opening, it further comprises a position adjusting means for bringing the valve plate into close contact with the casing. An elevating body that adjusts the position of the valve plate away from the plate, and elevating means that elevates the interior of the casing so that frictional resistance does not occur between the elevating body and the casing. It has an electromagnet that generates a magnetic force and pulls the lifting body, and controls the magnetic force generated by the electromagnet by controlling energization. The elevating body is moved up and down, and the elevating means includes a sensor for detecting the magnetic flux density by the electromagnet, and controls the energization to the electromagnet according to the magnetic flux density detected by the sensor to adjust the magnetic force. The lifting speed of the lifting body is controlled, and the sensor is provided in a casing, and provides a vacuum gate valve characterized by being detachable from the outside of the casing.

  According to the present invention, as a ninth means for solving the above-described problem, in any one of the first to eighth solving means, the elevating means includes a non-contact bellows on the casing. The present invention provides a vacuum gate valve that guides the raising and lowering of a lifting body when the body is raised and lowered.

The present invention provides, as a tenth means for solving the above-mentioned problems, a vacuum gate valve including a casing having an opening and a valve plate that swings in the casing to open and close the opening. When the valve is in the fully closed position with respect to the opening, it further comprises a position adjusting means for bringing the valve plate into close contact with the casing. An elevating body that adjusts the position of the valve plate away from the plate, and elevating means that elevates the interior of the casing so that frictional resistance does not occur between the elevating body and the casing. It has an electromagnet that generates a magnetic force and pulls the lifting body, and controls the energization to generate the magnetic force generated by the electromagnet. Sei and by lifting the lifting body, the lifting means comprises a non-contact of the bellows to the casing, the bellows, guides the vertical movement of the vertically movable body during the lifting of the lifting body, the bellows has a spring property Normal The present invention provides a vacuum gate valve characterized in that the elevating body is urged in the direction of pressing against the valve plate, and the electromagnet raises the elevating body against the urging force of the bellows.

  According to the present invention, as an eleventh means for solving the above-mentioned problems, in the ninth or tenth solving means, the bellows has one end connected to the casing side and the other end connected to the lifting body. Accordingly, the present invention provides a vacuum gate valve characterized by blocking the inflow of air to the back side of the valve plate.

According to the present invention, as a twelfth means for solving the above-mentioned problems, in any one of the ninth to eleventh solving means, the bellows is formed of a nonmagnetic material. A gate valve is provided.

  According to the present invention, as described above, the position adjusting means moves up and down in the casing and comes into contact with the valve plate to adjust the position of the valve plate. Since it is equipped with lifting means that raises and lowers the inside of the casing so that it does not occur, direct metal contact between the lifting body and the casing can be avoided, effectively preventing generation of particles and damage to the lifting body and casing There is an actual advantage that the vacuum gate valve can be suppressed and has excellent durability.

In this case, in particular, according to the present invention, as described above, the lifting body is installed in the casing while having a gap between the casing and the casing without an O-ring and grease. Since the lifting body can be lifted and lowered without making contact with the casing, it is possible to avoid generation of particles due to wear of the O-ring and volatilization of grease, and maintenance such as replacement of these O-rings and replenishment of grease. Work is not required and stable use for a long period of time is possible and maintenance is facilitated. On the other hand, since the sealing O-ring is provided, the O-ring for sealing moves up and down even though the gap exists. Even when the body is distant from the valve plate, it is kept airtight with the lifting means (adsorption body), and the back side of the valve plate (ascending And there is a practical benefits that can hold the side of the processing chamber side) opposite to the vacuum across the valve plate.

  According to the present invention, as described above, the lifting body is lifted by adjusting the magnetic force generated by the electromagnet, so that the lifting body can be lifted and lowered without mechanically holding the casing, In this case, the elevating speed of the elevating body is controlled by controlling the energization to the electromagnet and adjusting the magnetic force according to the magnetic flux density detected by the sensor that detects the magnetic flux density by the electromagnet. There is an actual advantage that it is possible to appropriately suppress the collision with the adsorbent and the valve plate due to unnecessary sudden rise or fall of the body, and to suppress the generation of particles due to the metal contact.

  According to the present invention, as described above, the sensor for detecting the magnetic flux density is, for example, an adsorbent and an elevator that are magnetized by an electromagnet, such as next to a gap between the adsorber and the elevator, and an elevator and an elevator. Because it is installed at a position outside the gap with the body, it can detect the magnetic flux density properly without being affected by heat and vacuum, and also the impact of the collision between the adsorbent and the lifting body. There is an advantage that the lifting speed of the lifting body can be accurately controlled.

  In this case, at a position outside the gap between the adsorbing body and the lifting body, the gap (interval) between the lifting body and the adsorbing body is large and the magnetic flux density is low in inverse proportion to the magnetic flux density in the gap. When the magnetic force is small, the magnetic flux density is large at the position away from the gap. Conversely, when the gap is eliminated and the lifting body is in close contact with the adsorbent, the magnetic flux density at the position away from the gap is Accordingly, the lower the magnetic flux density detected by the sensor, the stronger the magnetic force of the electromagnet, and the higher the magnetic flux density detected by the sensor, the weaker the magnetic force of the electromagnet. Even if the sensor is installed at a position away from the body or the gap, there is an advantage that the lifting speed of the lifting body can be appropriately controlled to a predetermined value according to the magnetic force.

  Further, according to the present invention, as described above, since the sensor is installed in the casing and can be detached from the outside of the casing, the sensor can be used even when maintenance or replacement such as inspection or cleaning becomes necessary. There is an advantage that it is easy to access and easily work.

  Further, according to the present invention, as described above, the elevating means guides the elevating body by the non-contact bellows (bellows-like spring) to the casing, so that the elevating body is brought into contact with the casing by the electromagnet. Even if it is lifted and lowered, there is an advantage that it can be lifted and lowered with an appropriate trajectory.

  According to the present invention, as described above, since the bellows has a spring property, the impact generated when the elevating body comes into contact with the adsorbent or the valve plate is absorbed, and the generation of particles due to the metal contact is suppressed. There is also a real benefit that can be done.

  In addition, according to the present invention, as described above, one end of the bellows is connected to the casing side and the other end is connected to the lifting body, so that the back side of the valve plate (the processing chamber side to be evacuated) Inflow of air to the chamber can be blocked, and the lifting body is not in contact with the casing without using an O-ring or the like, that is, there is a gap between the casing and the sealed state on the processing chamber side. There are real benefits that can be secured.

  In this case, according to the present invention, as described above, since the bellows is formed of a nonmagnetic material such as stainless steel, the bellows expands and contracts following the ascending / descending movement of the elevating body regardless of the magnetic force of the electromagnet. Thus, there is an actual advantage that the lifting body can be properly guided and buffered.

It is a partially broken perspective view of the vacuum gate valve of the present invention. It is sectional drawing of the gate valve for vacuums of this invention. It is sectional drawing which shows the state of the magnetic force by the electromagnet used for this invention. It is a graph which shows the distribution state of the magnetic flux density by the electromagnet used for this invention. It is sectional drawing which shows the state which the bellows used for this invention interrupts | blocks air | atmosphere. It is sectional drawing of other embodiment of the vacuum gate valve of this invention.

  An embodiment for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 and FIG. 2 show a vacuum gate valve 10 of the present invention, which is, for example, a semiconductor device (not shown). It is installed between a processing chamber used in this manufacturing process and a suction pump (not shown) for evacuating the processing chamber, and is used for sealing the inside of the processing chamber and keeping it in a vacuum.

  As shown in FIGS. 1 and 2, the vacuum gate valve 10 of the present invention includes a casing 12 having an opening 12a, a valve plate 14 that swings in the casing 12 to open and close the opening 12a, and the valve. A motor (not shown) for driving the plate 14 and a position adjusting means 16 for keeping the inside of the processing chamber in a vacuum by bringing the valve plate 14 into close contact with the casing 12 when the valve plate 14 is in the fully closed position with respect to the opening 12a. ing. The casing 12 is made of a nonmagnetic material such as aluminum.

  In the present invention, as shown in FIGS. 1 and 2, the position adjusting means 16 is moved up and down in the casing 12 to contact the valve plate 14 and adjust the position of the valve plate 14, Elevating means 20 for elevating and lowering the inside of the casing 12 so as to prevent frictional resistance between the body 18 and the casing 12 is provided. For this reason, since the direct metal contact of the raising / lowering body 18 and the casing 12 can be avoided, generation | occurrence | production of a particle and damage to the raising / lowering body 18 and the casing 12 can be suppressed effectively, and it was excellent in durability. A vacuum gate valve 10 can be obtained.

As shown in FIGS. 1 and 2, the elevating body 18 and the elevating means 20 are disposed at the periphery of the opening 12 a of the casing 12 and are accommodated in the casing 12. Therefore, as shown in FIG. 2, the sealed state can be maintained while saving space without greatly changing the size and shape of the casing 12 from the conventional design.

  As shown particularly in FIG. 1, the casing 12 includes a casing main body 12A and a cover 12B that is detachably attached to the casing main body 12A with bolts or the like. Therefore, the casing 12 is formed to be openable and closable by attaching and detaching the cover 12B. As shown in FIG. 1, the elevating body 18 and the elevating means 20 are detachably accommodated in the casing 12 by the openable / closable casing 12. For this reason, maintenance, such as inspection, maintenance, and repair, and replacement of the lifting body 18 and the lifting means 20 can be easily performed.

(1. Lifting body)
As shown in FIG. 1, the elevating body 18 has a ring shape along the periphery of the opening 12 a of the casing 12, and as shown in FIG. 2, the elevating body 18 has a valve along the contour of the disc-like valve plate 14. The valve plate 14 can be brought into close contact with the casing 12 in an annular shape near the outer periphery of the plate 14, that is, in contact with the valve plate 14 over the entire circumference of the valve plate 14. Only in the direction, there is no gap between the valve plate 14 and the casing 12, and the sealed state can be reliably maintained.

  Further, as shown in FIGS. 1 and 2, the elevating body 18 is connected to a bowl-like elevating body main body 18A having a concave longitudinal section and the lower side of the elevating body main body 18A to push down the valve plate 14. It consists of the pressing member 18B. In this case, as shown in FIG. 2, the pressing member 18 </ b> B is fitted to the lifting body main body 18 </ b> A and connected through the main body side O-ring 22 </ b> A, while the plate side O-ring is also connected to the surface in contact with the valve plate 14. 22B is installed and can be elastically engaged with the lifting body main body 18A and the valve plate 14.

For this reason, the pressing member 18B can absorb an impact when contacting the valve plate 14, and at the same time, the pressing member 18B also absorbs a twist caused by a slight displacement of the valve plate 14 in the lateral direction. The twist is not transmitted to 18A. As shown in FIG. 2B, the plate-side O-ring 22B is connected to the valve plate 14 as shown in FIG. 5B when the elevating body 18 is in close contact with the valve plate 14. The space between the valve plate 14 and the back side of the valve plate 14 (the process chamber side opposite to the lift plate 18 with the valve plate 14 in between) is maintained in a vacuum state.

  On the other hand, as shown particularly in FIG. 2, the lifting body 18 includes a lifting body main body 18A and has a slight gap between the casing 12 and the casing 12 without an O-ring and grease. However, it is installed in the casing 12. Therefore, the elevating body 18 can be moved up and down without contacting the casing 12 by moving up and down while maintaining the position state shown in FIG. For this reason, wear of the O-ring and generation of particles due to the volatilization of grease can be avoided, and at the same time, maintenance work such as replacement of these O-rings and replenishment of grease is not required, and it can be used stably for a long time. Maintenance at the same time. The elevating body 18 is formed of a magnetic material, specifically, for example, SUS403, which is ferromagnetic stainless steel. When the electromagnet 24 of the elevating means 20 described later generates a magnetic force by energization, the elevating body 18 is magnetized. Tinged.

(2. Lifting means)
As shown in FIGS. 1 and 2, the elevating means 20 attracts the elevating body 18 by being magnetized by the electromagnet 24 installed in the casing 12 and generating magnetism by energization and attracting the elevating body 18. It has an adsorbent body 26 and a bellows 28 that is installed in the recess of the elevator 18 and connects the adsorber 26 and the elevator 18.

(2-1 Adsorbent)
As shown in FIGS. 1 and 2, the adsorbing body 26 has a ring shape along the periphery of the opening 12 a of the casing 12, similar to the lifting body 18, and corresponds to the entire circumference of the lifting body 18. Provided. As shown in FIGS. 1 and 2, the adsorbent 26 has an inverted concave longitudinal section, and the top surface (the bottom surface of the recess) of the inverted recess is formed on the casing 12 by screws 30 at a plurality of locations. By being fixed, it is arranged in the casing 12. In this case, the adsorbent 26 is installed in the casing 12 via two sealing O-rings 32, as particularly shown in FIG. As shown in FIG. 2 (A), these two sealing O-rings 32 are connected to the adsorbent 26 as shown in FIG. 5 (A) when the elevating body 18 is separated from the valve plate 14. The space between the lift plate 18 and the valve plate 14 (the process chamber side opposite to the lift plate 18 with the valve plate 14 in between) is maintained in a vacuum state.

  The adsorbent 26 is also made of a magnetic material, specifically, for example, SUS403, which is a ferromagnetic stainless steel, and is magnetic when the electromagnet 24 generates a magnetic force when energized. Take on.

(2-2 Electromagnet)
On the other hand, as shown in FIGS. 1 and 2, the electromagnet 24 has a ring shape along the periphery of the opening 12 a of the casing 12, and is provided corresponding to the entire circumference of the elevating body 18. As shown particularly in FIG. 2, the electromagnet 24 is housed in the inside of the adsorbing body 26 by a lid portion 34 that is housed in the reverse concave shape of the adsorbing body 26 and closes the concave opening of the adsorbing body 26. The The lid 34 is made of a nonmagnetic material such as SUS304 so as not to be affected by the magnetic field generated by the magnet.

  The electromagnet 24 includes a magnetic core material (not shown) and a coil wound around the magnetic core material. The coil is connected to a power source (not shown), and a current flows through the coil by energization from the power source. Generates magnetic force when Therefore, the electromagnet 24 generates magnetism by energization, thereby causing the attracting body 26 and the lifting body 18 to become magnetized, and the attracting body 26 attracts the lifting body 18 as shown in FIG. The elevating body 18 can be raised by sucking it toward the electromagnet 24 side. On the other hand, by stopping energization of the electromagnet 24, the electromagnet 24 loses the magnetic force, releases the lifting body 18 from the attracting body 26, and allows the lifting body 18 to descend. Can be lowered.

  In this case, if the lifting / lowering of the lifting / lowering body 18 is controlled only by turning on / off the current to the coil of the electromagnet 24, only the rising / lowering control is performed. The impact at the time of a collision (when rising) or a collision of the lifting body 18 with the valve plate 14 (at the time of lowering) is increased, particles are generated by the metal contact, the lifting body 18, the adsorbing body 26, and the valve plate 14. There is also a risk of damage. For this reason, it is desirable that the elevating means 20 elevate the elevating body 18 by adjusting the magnetic force generated by the electromagnet 24 by controlling energization to the electromagnet 24.

(2-3 Sensor)
Specifically, as shown in FIG. 2, the lifting / lowering means 20 also has a sensor 36 for detecting the magnetic flux density by the electromagnet 24, and the electromagnet 24 is energized according to the magnetic flux density detected by the sensor 36. Thus, the lifting speed of the lifting body 18 can be controlled by adjusting the magnetic force. For this reason, the collision with the adsorption body 26 and the valve plate 14 due to the unnecessary rapid rise or fall of the lift 18 can be appropriately suppressed, and the generation of particles due to the metal contact can be suppressed.

  In this case, in order to measure the strength of the magnetic force by the sensor 36, it can be said that the sensor 36 is preferably installed on a part of the adsorbent 26 which is originally magnetized by the electromagnet 24. However, since the adsorbent 26 is in a high temperature state of about 80 ° C. to 120 ° C., it is necessary to consider heat resistance. Moreover, although it can be said that it is preferable to install between the adsorption body 26 and the raising / lowering body 18 in order to measure a magnetic flux density appropriately, if it installs in the gap 38 part, the sensor 36 will be the adsorption body 26 and the elevation body 18 There is also a risk of being affected by an impact at the time of a collision with the robot. Therefore, in the present invention, as shown in FIG. 2, the sensor 36 is not a part of the adsorbent body 26 and the lift body 18 that are magnetized by the electromagnet 24, and the adsorber body 26 and the lift body 18. It is installed in the position which also removed from the gap 38 (refer FIG. 2) between. Specifically, in the illustrated embodiment, as shown in FIG. 2, the sensor 36 includes a sensor hole 12 b provided beside the gap 38 between the adsorbent body 26 and the lifting body 18 in the casing 12. The magnetic flux density at the position next to the gap 38 between the attracting body 26 and the lifting body 18 by the electromagnet 24 is detected.

  In this way, the sensor 36 is installed at a location that is not part of the adsorbent body 26 or the lifting body 18 that is at a high temperature, so that it is not affected by heat and is also installed at a position away from the gap 38. Therefore, the magnetic flux density can be appropriately detected without being affected by the impact at the time of the collision between the adsorbing body 26 and the lifting body 18. Furthermore, since the sensor 36 is installed beside the gap 38 between the adsorbent body 26 and the lifting body 18 that are always located on the atmosphere side, it can detect the magnetic flux density appropriately without being affected by the vacuum. The raising / lowering speed of the raising / lowering body 18 can be accurately controlled.

  In this case, if the magnitude of the current flowing through the electromagnet 24 is constant and the strength of the magnetic force itself is the same, the magnetic flux density is the gap 38 (between the adsorbing body 26 and the lifting body 18) as shown in FIG. In this case, the smaller the gap 38, the higher the magnetic flux density and the stronger the magnetic force, and the larger the gap 38, the smaller the magnetic flux density and the weaker the magnetic force. Therefore, when the sensor 36 is installed in the gap 38 or a part of the adsorbent 26, the detected magnetic flux density directly reflects the current magnetic strength, that is, if the magnetic flux density is large, the magnetic force Is strong and the magnetic flux density is small, it can be determined that the magnetic force is weak.

  However, as in the present invention, when the sensor 36 is installed at a position away from the gap 38 or the magnetized adsorbent 26, the measured magnetic flux density cannot be directly grasped as the strength of the magnetic force. Can not. Because, similarly as shown in FIG. 4, the magnetic flux density is inversely proportional to the magnetic flux density in the gap 38 (between the adsorbing body 26 and the lifting body 18) at a position away from the gap 38 (lateral direction of the gap 38). This is because the larger the gap 38, the higher the magnetic flux density (weaker the magnetic force), and the smaller the gap 38, the lower the magnetic flux density (stronger magnetic force). In this case, when the gap 38 is “0”, that is, when the elevating body 18 is in close contact with the attracting body 26, the strength of the magnetic force is maximized, and the magnetic flux density of the sensor 36 provided beside the gap 38. The detection value is “0”.

  Therefore, in the present invention, it is determined that the lower the magnetic flux density detected by the sensor 36 is, the stronger the magnetic force of the electromagnet 24 is, and the higher the magnetic flux density detected by the sensor 36 is, the weaker the magnetic force of the electromagnet 24 is. The lowering speed of the lifting body 18 is controlled to a predetermined value according to this magnetic force. Specifically, as a result of measurement by the sensor 36, in order to obtain a predetermined target ascending / descending speed, if the magnetic force is too strong and it is desired to decrease the ascending speed or increase the descending speed, When the current flowing through the coil of the electromagnet 24 is decreased to adjust the ascending / descending speed by weakening the magnetic force, conversely, when the magnetic force is weak and it is desired to increase the ascending speed or decrease the descending speed, By increasing the flowing current, the magnetic force can be increased to adjust the lifting speed. Thereby, the collision with the adsorbent 26 and the valve plate 14 due to the unnecessary rapid rise or fall of the elevating body 18 can be appropriately suppressed, and the generation of particles due to the metal contact can be suppressed.

  As shown in FIGS. 1 and 2, the sensor 36 is disposed in the sensor hole 12 b that communicates with the outside of the casing 12, so that the sensor 36 can be detached from the outside of the casing 12. For this reason, even if maintenance or replacement such as inspection or cleaning of the sensor 36 is necessary, the sensor 36 can be easily accessed and easily operated.

(2.-4 Bellows)
Further, the bellows 28 of the elevating means 20 has a role of guiding the ascent / descent of the elevating body 18 when the elevating body 18 is elevated. That is, when the elevating body 18 is disposed in a free state inside the casing 12 without providing the bellows 28 and the elevating body 18 is moved up and down by simply attracting and releasing the electromagnet 24, the elevating body 18 is moved up and down in the casing 12. There is a possibility that metal contact may occur between the body 18 and the casing 12 when the body 18 is tilted or distorted. For this reason, even if the position of the lifting / lowering body 18 is regulated by the bellows 28 and the lifting / lowering body 18 is lifted / lowered without being brought into contact with the casing 12 by the electromagnet 24, it can be lifted / lowered with an appropriate track.

  In this case, as shown in FIGS. 1 and 2, the bellows 28 itself is also installed in the recess of the elevating body 18, so that it does not contact the casing 12, that is, the elevating body 18 and the casing 12 The elevating body 18 can be guided with a gap between them, and at the same time, unlike the O-ring conventionally used, the bellows 28 itself may come into contact with the casing 12 and cause particles due to metal contact. Absent.

  Specifically, the bellows 28 is a bellows-like spring and has a spring property (elasticity). In this case, the bellows 28 having the spring property is normally biased in the direction of pressing the elevating body 18 against the valve plate 14 (in a natural state), and the electromagnet 24 resists the biasing force of the bellows 28. The elevating body 18 can be raised, while the elevating body 18 can be lowered in a direction in which the elevating body 18 is pressed against the valve plate 14 by the restoring force of the bellows 28 as the electromagnet 24 is de-energized or lowered. For this reason, as shown in FIG. 2B, the bellows 28 is absorbed while absorbing the impact generated when the elevating body 18 comes into contact with the adsorbent 26 and the valve plate 14 and suppressing the generation of particles due to the metal contact. Due to this elasticity, the elevating body 18 can be brought into close contact with the valve plate 14 so as to push down the valve plate 14, and the valve plate 14 can be brought into close contact with the casing 12 to keep a sealed state, while resisting the magnetic force of the electromagnet 24. When the bellows 28 is compressed, as shown in FIG. 2A, the lifting body 18 is moved away from the valve plate 14, the valve plate 14 is released from the casing 12, and the valve plate 14 is swung. Can be tolerated. In this case, in the fully closed state shown in FIG. 2 (B), the interval between the bellows 28 of the bellows-like bellows 28 is of course about 25 mm, although it depends on the number of ribs. In the fully open state shown in FIG.

  As shown in FIG. 2, the bellows 28 has one end (upper end) connected to the casing 12 side (specifically, the adsorbing body 26) and the other end (lower end) connected to the lifting / lowering body 18 (specifically, , The elevating body 18 is connected to the adsorbing body 26. As a result, as shown in FIG. 5B in particular, even when the valve plate 14 is in close contact with the casing 12, the valve plate 14 passes through the gap 38 between the elevating body 18 and the adsorbing body 26. Air can be blocked from flowing into the back side (the processing chamber side opposite to the lifting body 18 with the valve plate 14 in between), and the lifting body 18 is not separated from the casing 12 without using an O-ring or the like. It is possible to ensure a sealed state on the processing chamber side while being in contact, that is, with a gap between the casing 12 and the casing 12.

  Further, the bellows 28 is made of a nonmagnetic material such as stainless steel. Specifically, the bellows 28 can be formed from SUS304. For this reason, the bellows 28 can expand and contract following the ascending / descending movement of the elevating body 18 regardless of the magnetic force by the electromagnet 24, and can appropriately exhibit the guide and buffering action of the elevating body 18.

(3. Valve plate)
As shown in FIG. 2A, the valve plate 14 is set so that a gap is formed between the valve plate 14 and the casing 12 when the valve plate 14 is released from the close contact state with the casing 12 by the position adjusting means 16. Specifically, a gap of about 1 mm is set between the casing 12 and the casing 12. As a result, the valve plate 14 can be prevented from coming into contact with the casing 12 or the like at the time of swinging, and as a result, damage or the like can be prevented, thereby ensuring smooth swinging. That is, the position adjusting means 16 is for closely contacting the valve plate 14 to the casing 12 as shown in FIG. 2B against the position setting of the valve plate 14 in the free state.

In the embodiment shown in FIG. 2, a body side O-ring 22A is provided on the upper surface of the pressing member 18B of the lifting body 18 and a plate side O-ring 22B is provided on the lower surface, so that the lifting body 18 is connected to the lifting body body 18A and the valve plate 14. As shown in FIG. 6 , it is attached to the inner peripheral surface of the pressing member 18B, and can be elastically engaged with both the lifting body 18A and the valve plate 14 at the same time. One bonded O-ring 40 having a large target diameter can also be used.

  The valve plate 14 may be provided with a ring-shaped cushion material (not shown) that elastically contacts the casing 12 when closely attached to the casing 12. As a result, even if the valve plate 14 is pressed against or slides on the casing 12 for sealing, the direct metal contact can be avoided, so that the generation of particles at the time of close contact can be effectively suppressed. Further, even when the valve plate 14 swings or the like, even if it collides with the casing 12 due to an unexpected error, it is possible to effectively suppress generation of particles and damage to the valve plate 14 and the casing 12. it can.

  In particular, the present invention can be widely applied to an etching apparatus in a semiconductor device, thin film processing by CVD, PVD, and a processing chamber used for manufacturing a flat panel display.

DESCRIPTION OF SYMBOLS 10 Vacuum gate valve 12 Casing 12A Casing main body 12B Cover 12a Opening 12b Sensor hole 14 Valve plate 16 Position adjustment means 18 Elevating body 18A Elevating body main body 18B Pressing member 20 Elevating means 22A Main body side O-ring 22B Plate side O-ring 24 Electromagnet 26 Adsorbent 28 Bellows 30 Screw 32 O-ring for sealing 34 Lid 36 Sensor 38 Gap 40 Bonded O-ring

Claims (12)

In a vacuum gate valve comprising a casing having an opening and a valve plate that swings in the casing to open and close the opening, the valve plate is moved when the valve plate is in a fully closed position with respect to the opening. The position adjusting means further includes a position adjusting means for closely contacting the casing, and the position adjusting means closely contacts the valve plate by lowering the inside of the casing, and adjusts the position of the valve plate away from the valve plate by rising. And an elevating means for elevating and lowering the inside of the casing so that frictional resistance does not occur between the elevating body and the casing, and the elevating body includes an O-ring and grease between the casing and the casing. Installed in the casing with a gap between the casing and the casing. Even when the elevating body is separated from the valve plate while the gap exists between the elevating body and the casing between the elevating means and the casing. A vacuum gate valve, characterized in that a sealing O-ring for holding the processing chamber in a vacuum state is provided . 2. The vacuum gate valve according to claim 1 , wherein the elevating means elevates and lowers the elevating body without contacting the casing. 3. The vacuum gate valve according to claim 1, wherein the elevating means has an electromagnet that generates a magnetic force by energization and draws the elevating body, and controls the energization. A vacuum gate valve characterized by adjusting the magnetic force generated by the electromagnet to raise and lower the elevating body. 4. The vacuum gate valve according to claim 3, wherein the elevating means includes a sensor for detecting a magnetic flux density by the electromagnet, and energizing the electromagnet according to the magnetic flux density detected by the sensor. The vacuum gate valve is characterized in that the elevating speed of the elevating body is controlled by adjusting the magnetic force by controlling the magnetic force. In a vacuum gate valve comprising a casing having an opening and a valve plate that swings in the casing to open and close the opening, the valve plate is moved when the valve plate is in a fully closed position with respect to the opening. The position adjusting means further includes a position adjusting means for closely contacting the casing, and the position adjusting means closely contacts the valve plate by lowering the inside of the casing, and adjusts the position of the valve plate away from the valve plate by rising. And an elevating means for elevating and lowering the inside of the casing so that friction resistance does not occur between the elevating body and the casing, and the elevating means generates a magnetic force by energization to Having an attracting electromagnet, adjusting the magnetic force generated by the electromagnet by controlling the energization The elevating body is moved up and down, and the elevating means includes a sensor for detecting a magnetic flux density by the electromagnet, and controls energization to the electromagnet according to the magnetic flux density detected by the sensor to The elevating speed of the elevating body is controlled by adjusting the electromagnet , and the electromagnet is installed in the casing and is installed inside the adsorbing body that is magnetized by the electromagnet and adsorbs the elevating body. It is installed at a position deviated from the gap between the attracting body and the lifting body and the attracting body and the lifting body magnetized by an electromagnet, and detects the magnetic flux density by the electromagnet. Gate valve. 6. The vacuum gate valve according to claim 5, wherein the sensor is installed beside a gap between the adsorbent and the lift. The vacuum gate valve according to claim 5 or 6, wherein the elevating means determines that the magnetic force of the electromagnet is stronger as the magnetic flux density detected by the sensor is lower, The vacuum gate valve characterized by determining that the magnetic force of the electromagnet is weaker as the magnetic flux density detected by the sensor is higher, and controlling the lifting speed of the lifting body to a predetermined value according to the magnetic force . In a vacuum gate valve comprising a casing having an opening and a valve plate that swings in the casing to open and close the opening, the valve plate is moved when the valve plate is in a fully closed position with respect to the opening. The position adjusting means further includes a position adjusting means for closely contacting the casing, and the position adjusting means closely contacts the valve plate by lowering the inside of the casing, and adjusts the position of the valve plate away from the valve plate by rising. And an elevating means for elevating and lowering the inside of the casing so that friction resistance does not occur between the elevating body and the casing, and the elevating means generates a magnetic force by energization to Having an attracting electromagnet, adjusting the magnetic force generated by the electromagnet by controlling the energization The elevating body is moved up and down, and the elevating means includes a sensor for detecting a magnetic flux density by the electromagnet, and controls energization to the electromagnet according to the magnetic flux density detected by the sensor to The vacuum gate valve is characterized in that the elevating speed of the elevating body is controlled by adjusting the elevating body, and the sensor is installed in the casing and can be attached and detached from the outside of the casing. 9. The vacuum gate valve according to claim 1, wherein the elevating means includes a non-contact bellows on the casing, and the bellows is moved up and down when the elevating body is moved up and down. A vacuum gate valve characterized by guiding the lifting and lowering of the lifting body. In a vacuum gate valve comprising a casing having an opening and a valve plate that swings in the casing to open and close the opening, the valve plate is moved when the valve plate is in a fully closed position with respect to the opening. The position adjusting means further includes a position adjusting means for closely contacting the casing, and the position adjusting means closely contacts the valve plate by lowering the inside of the casing, and adjusts the position of the valve plate away from the valve plate by rising. And an elevating means for elevating and lowering the inside of the casing so that friction resistance does not occur between the elevating body and the casing, and the elevating means generates a magnetic force by energization to Having an attracting electromagnet, adjusting the magnetic force generated by the electromagnet by controlling the energization Raises and lowers the lift Te, said lifting means comprises a bellows of a non-contact with the casing, said bellows, guides the elevation of the elevating body during the lifting of the lifting body, the bellows spring property The vacuum gate valve is characterized in that it normally urges the elevating body in a direction of pressing against the valve plate, and the electromagnet raises the elevating body against the urging force of the bellows. 11. The vacuum gate valve according to claim 9, wherein one end of the bellows is connected to the casing side, and the other end is connected to the elevating body. A vacuum gate valve characterized by blocking the inflow of air to the back side. The vacuum gate valve according to any one of claims 9 to 11, wherein the bellows is formed of a nonmagnetic material.