Pneumatic intake valve with adjustable stopper

Abstract

The present invention relates to an intake valve for controlling fluid entry into a vacuum processing chamber wherein the intake valve (1) comprises: a gas channel unit (2) wherein the gas channel unit has a sealing surface (24) in an internal volume (23); an adjustment device (3) having an adjustment unit (31), wherein the adjustment unit (31) protrudes into the interior volume (23) and is mounted in the adjustment device (3) outside the gas channel unit (2) so as to be adjustable along an adjustment axis; and a flexible sealing element (25) connected to the gas channel unit (2) and to the adjustment unit (31) and sealingly isolating the adjustment device (3) from the internal volume (23). The adjusting device (3) has a pretensioning element (34) which is arranged and interacts with the adjusting unit (31) in such a way that a pretensioning force can be provided which presses the valve disk (32) in the closing direction (S). The adjusting device (3) has a pneumatic drive cylinder (35) with at least one piston (36a), the piston (36a) being connected to the adjusting unit (31) and an opening force opposite the preload force can be generated in the opening direction (O) by pressurizing the drive cylinder (35). The adjusting device (3) has a limiting element (37) which provides a limiting point (38) which limits the adjustability of the adjusting unit (31) along the adjusting axis (V) in the opening direction (O). The limiting element (37) is shaped and mounted in such a way that the position of the limiting point (38) along the adjustment axis (V) can be changed by actuating the limiting element (37), wherein the position of the limiting point (38) defines the maximum opening degree of the valve.

Description

Technical Field

[0001] The present invention relates to an inlet valve for introducing fluid into a vacuum processing chamber. Background Art

[0002] Such vacuum processing chambers are used in the manufacture of integrated circuits (ICs), semiconductors, flat panels or substrates, where the vacuum chamber needs to be filled with process gases for at least some of the process steps after evacuation. The manufacturing process must be carried out in a protected atmosphere and the presence of contaminating particles must be avoided as much as possible. Evacuation is achieved via a vacuum valve, which connects the vacuum processing chamber to a vacuum pump and has different design and technical requirements than an inlet valve.

[0003] In addition, such vacuum chambers have at least one or two vacuum chamber openings through which the components to be processed can enter and exit the vacuum chamber. For example, in a production system for semiconductor wafers or liquid crystal substrates, highly sensitive semiconductor or liquid crystal components pass through multiple vacuum processing chambers in sequence, and the processing device in each chamber processes the components.

[0004] For example, the component can be placed by a robot arm on extended support pins of a lifting system and deposited on a support, such as a potential plate (chuck), by lowering the support pins. Afterwards, the robot arm, which usually carries the component, is moved out of the chamber. After the component has been deposited, the support pins can be lowered and separated from the component, i.e. there is no contact between the pins and the component. After the robot arm has been removed and the chamber has been closed, the chamber is usually evacuated and then filled with process gas, and then the processing of the component begins.

[0005] Inlet valves are specially designed for precise control or regulation of gas flow, such as in a piping system between a vacuum processing chamber (or transfer chamber) and a gas source, atmosphere, or another vacuum processing chamber. Such inlet valves usually have a smaller opening cross-sectional area than vacuum valves.

[0006] Depending on the application requirements, the inlet valve can be used not only to fully open and close the opening, but also to control or regulate the flow by continuously adjusting the opening cross-section between the fully open position and the gas-tight closed position.

[0007] When filling a vacuum chamber with process gases, low flow effects in the chamber and fast and precise filling of the chamber are crucial. For example, a certain amount or volume of a specific process gas needs to be introduced into the chamber in a single opening cycle of the inlet valve. For this purpose, fast actuation of the valve is required on the one hand and precise adjustment of the valve opening cross-section set in the process on the other.

[0008] Purpose of the Invention

[0009] It is therefore an object of the present invention to provide an improved vacuum processing chamber gas inlet valve.

[0010] In particular, the purpose is to achieve rapid and continuous precise filling of a vacuum processing chamber with process gas by means of the gas inlet valve.

[0011] Another object of the present invention is to maintain a stable opening cross-sectional area over a long period of time.

[0012] A further object is to provide, inter alia, an inlet valve that provides a stable flow coefficient for a particular process fluid. Summary of the invention

[0013] The present invention relates to an air inlet valve with pneumatic drive for controlling the opening of the valve. The air inlet valve comprises a restoring element (especially a spring) which presses the valve disc against the valve seat, thereby blocking the flow path of the fluid through the valve. Through the pneumatic drive, a force can be generated to overcome the restoring force of the restoring element, thereby opening the valve.

[0014] In the present invention, the fluid at least includes gas, gas mixture, liquid, gas containing precursor or gas-liquid mixture. In particular, the fluid can be a process gas or a precursor gas.

[0015] The valve disc and / or the valve seat (sealing surface) can be provided with a sealing ring which is compressed in the closed position. The compression is caused by the preload force of the return element and ensures a gas-tight separation between the inlet and the outlet.

[0016] A limiter is provided to limit the valve stroke, i.e. the distance the valve disc moves during the opening process. This means that, on the one hand, a relatively rapid opening of the valve disc (e.g. compared to an electromechanical drive with an electric motor) can be achieved by applying pneumatic pressure to the drive, and on the other hand, the opening movement can be limited accordingly. Thus, a constant flow per unit time can be provided simply by pressurizing the pneumatic drive.

[0017] By controlling the pressurization duration, the amount of fluid flowing through the valve (eg, into the vacuum chamber) during the valve opening cycle can be further adjusted.

[0018] The limiter of the intake valve is further configured as follows: the limit point limits the adjustability of the valve disc in the opening direction along the linear adjustment axis, and the position of the limit point can be moved along the adjustment axis by operating the limiter.

[0019] Therefore, the limit point defines the maximum opening degree of the valve when the pneumatic drive is pressurized (especially the stroke of the valve disc, that is, the distance between the valve disc and the valve seat). By moving the limit point, the valve stroke can be adjusted accordingly.

[0020] The invention relates to an air inlet valve for controlling fluid to enter a vacuum processing chamber. The air inlet valve comprises a gas channel unit having an air inlet, an air outlet and an inner volume. The inner volume communicates with the air inlet and the air outlet, and a sealing surface is arranged in the inner volume.

[0021] The inlet valve also has an adjustment device, which has an adjustment unit, wherein the adjustment unit extends into the inner volume and is mounted in the adjustment device outside the gas channel unit so as to be adjustable along an adjustment axis, wherein the adjustment unit has a valve disc located in the inner volume. The valve disc can be moved by the adjustment device in a closing direction to a closing position (the valve disc abuts against the sealing surface to prevent gas from passing through) or in an opening direction to an opening position (the valve disc is separated from the sealing surface to allow gas to pass through).

[0022] The adjusting device further comprises a pneumatic drive cylinder having at least one piston, wherein the piston is connected to the adjusting unit and an opening force can be generated in the opening direction by pressurizing the drive cylinder or the piston. In particular, the pneumatic drive cylinder can be designed to generate a closing force in the closing direction by changing the pressurization method (for example, pressurizing on the other side of the piston). The pressurization can be achieved, for example, by at least one compressed air outlet extending into the drive cylinder or built in. The compressed air outlet is in particular connected to the pneumatic unit or the pneumatic valve.

[0023] The valve further comprises a flexible sealing element which is connected to the gas channel unit and the regulating unit and which isolates or seals the regulating unit from the inner volume. The sealing element is in particular designed as a metal-containing diaphragm.

[0024] According to the present invention, the regulating device has a limiting element, which provides a limiting point to limit the adjustability of the regulating unit along the regulating axis in the opening direction. The shape and installation method of the limiting element enable the position of the limiting point along the regulating axis to be changed by operating the limiting element, and the position defines the maximum opening degree of the valve.

[0025] The position of the limit point also defines, in particular, the open position of the valve.

[0026] Thus, operating the stop element enables an adjustment of the stop point along the adjustment axis. This adjustment function is particularly advantageous because valves of the same manufacture may have different valve strokes (and maximum valve opening cross-sectional areas) due to the manufacturing process, due to possible dimensional and / or bearing tolerances of the valve and its (mechanical and movable) parts. The valve stroke corresponds in particular to the distance that the valve disc moves from the maximum open position to the closed position (or vice versa). Thus, the possibility of adjusting the stop point provides a calibration function for the intake valve, i.e. the valve stroke or the maximum valve opening is adjusted so that each manufactured valve has the same flow characteristics (in particular the same valve stroke) after calibration.

[0027] In particular, the calibration of the valve can be automated. To this end, the flow rate of the valve, preferably in the open position, can be measured and the flow rate through the valve can be adjusted to a set value by setting or adjusting the position of the stop point. Alternatively, the dynamic pressure upstream of the valve can be measured to determine the flow coefficient (C v ). It is also possible to measure the pressure loss of the valve.

[0028] In one embodiment, the regulating device may have a preload element, which is arranged and interacts with the regulating unit in a manner (especially one or more springs or elastic elements) so as to provide a preload force in the closing direction to push the valve disc. In particular, the preload element is in a properly preloaded state when the valve is in the open position.

[0029] Pressurizing the drive cylinder can generate an opening force in the opening direction that overcomes the preload force. In particular, the preload element can be in active contact with at least one piston.

[0030] The air intake valve of the present invention combines the advantages of a pneumatically driven cylinder for achieving rapid valve opening, as well as a high-precision and flexibly adjustable valve opening degree (for example, adjustment according to different fluids flowing through).

[0031] In one embodiment, the intake valve may include a controllable driving device, which is connected or coupled to the limiting element, so that the position of the limiting point can be changed by the driving device.

[0032] In particular, the drive device can be designed as an electric motor (especially a servomotor or a stepper motor), a piezoelectric element or an actuator based on the magnetic suspension principle (such as a permanent magnet linear motor).

[0033] The connection of the limiting element to the drive device in particular makes it possible to control and / or automatically operate the limiting element, so that the position of the limiting point can be controlled and / or automatically adjusted accordingly.

[0034] In one embodiment, the air intake valve may comprise a control and processing unit, which is arranged at least for controlling the drive means.

[0035] In one embodiment, the control and processing unit may have an adjustment function for adjusting the position of the limit point, wherein the adjustment function is configured to perform the following steps during operation: processing reference information (such as set pressure, set temperature, set flow, etc.); processing actual information (such as actual pressure, actual temperature, actual flow, fluid density and / or composition, etc.); comparing the reference information with the actual information; deriving adjustment information based on the comparison; and adjusting the position of the limit point according to the adjustment information (especially automatic adjustment).

[0036] The automatic adjustment of the position of the limit point can be realized, for example, by closed-loop control. In this case, the adjustment function can be continuously executed until the adjustment information obtained by comparing the reference information with the actual information determines that no further operation of the limit element is required.

[0037] According to one embodiment, the actual information may have information about the fluid properties (especially the fluid composition, type or nature), while the reference information may provide a correspondence between the fluid properties and the position of the stop point. This allows, for example, automatic adjustment of the opening position according to the fluid used and providing the required flow rate for a specific fluid in an automatically controlled manner. The information about the fluid properties may, for example, be provided by a user.

[0038] In one embodiment, the reference information may have information about a set pressure of the fluid, and the actual information may provide the current fluid pressure, in particular wherein the intake valve has a pressure sensor for determining the fluid pressure.

[0039] According to one embodiment, the reference information may have information about a set temperature of the fluid, and the actual information may provide the current temperature of the fluid, in particular wherein the intake valve has a temperature sensor for determining the temperature of the fluid.

[0040] In one embodiment, the reference information may include information about a set flow coefficient of the fluid, and the actual information may provide a current flow coefficient of the fluid, in particular wherein the intake valve has a flow measurement unit for determining the flow coefficient of the fluid.

[0041] According to one embodiment, the reference information may include information about a set flow coefficient, while the actual information may specify or provide a density and / or a temperature or a pressure difference of the fluid, in particular wherein the fluid flow coefficient of the fluid may be derived as actual information using the density and / or the temperature of the fluid and / or using the pressure difference.

[0042] The flow coefficient is specifically a measure of the achievable flow rate of a fluid (liquid or gas) through a valve. This can also be interpreted as the effective cross-sectional area.

[0043] The pressure difference corresponds in particular to the pressure difference between the gas inlet and the gas outlet. The gas inlet valve can in particular be provided with a corresponding pressure sensor for determining the pressure difference.

[0044] In one embodiment, the control and processing unit may have a compensation function for compensating for a position offset relative to a set position, wherein the compensation function is configured to, when executing the function, perform the following steps: verifying whether there is a position offset; determining or deriving (if there is a position offset) an expression for the position offset, in particular the amount and / or direction of the position offset; and tracking the position of the limit point, in particular changing the position of the limit point so that the set position is reached when in the open position.

[0045] The position offset can be, in particular, a position deviation of the valve disk in the open position or a position deviation of the stop point relative to a corresponding set position of the valve disk or the stop point.

[0046] Checking the presence of a position offset or determining a representation of the position offset can in particular be performed by a position measurement or a flow measurement, by determining the temperature of the intake valve or on the basis of the number of opening cycles performed by the intake valve.

[0047] For example, it is known from experience that after a certain number of opening and closing cycles a valve will have a certain deflection, for example due to wear of the valve disc or wear of the seal. Based on this information, the stop point can then be readjusted compensatorily, continuously or in discrete steps, for example for the first time after a certain number of cycles.

[0048] According to another example, the offset characteristic can be predetermined or known according to the thermal state of the valve (ie, the current temperature of the valve), and the limit point can then be adjusted accordingly to offset the offset.

[0049] Furthermore, for example, the inventive principle can be used not only to compensate for wear-related deflections, but also for compensating for narrowing of the flow cross-sectional area due to deposits (deposition), for example caused by process gases, in particular precursors.

[0050] In order to provide a constant gas input to the process volume, the flow can also be compensated by adjusting the stop point during the gas inlet process. This compensation can be advantageous due to pressure drops that occur in the upstream gas tank during the process.

[0051] In one embodiment of the inlet valve, the pneumatically driven cylinder may include another piston, wherein each piston defines a respective driven internal volume. Each driven internal volume may be connected to a respective compressed air channel, and the compressed air channel is arranged in such a way that the piston can be adjusted in the opening direction by pressurizing the driven internal volume through the compressed air channel, thereby causing the valve disc to reach the open position.

[0052] In one embodiment of the inlet valve, the sealing surface, the valve disk and the sealing element may have a circular cross-section, wherein the inner volume is at least partially cylindrical and wherein the sealing surface is formed by a shoulder in the inner volume.

[0053] The cylindrical shape of the inner volume is formed in particular by the gas channel unit as the housing surface and the sealing element as the bottom surface, wherein the gas inlet and the gas outlet can freely enter the inner volume through the housing surface. This means that the gas inlet and the gas outlet can each penetrate the housing surface.

[0054] In particular, in the closed position, the valve disc divides the interior volume into a first and a second partial interior volume, the first partial volume being freely accessible to the gas inlet and the second partial volume being freely accessible to the gas outlet.

[0055] In an arrangement in connection with a vacuum chamber, the gas outlet opening can in particular be freely accessible to the vacuum processing chamber and the gas inlet opening can in particular be freely accessible to a process gas source. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Further advantages of the present invention will become apparent from the detailed description and accompanying drawings.

[0057] Figure 1 A cross-sectional view showing an embodiment of an intake valve according to the present invention;

[0058] Figure 2 Shows Figure 1 The intake valve of the present invention is relative to Figure 1 A cross-sectional view rotated about a vertical axis; and

[0059] Figure 3 The internal volume of the intake valve is shown in detail. DETAILED DESCRIPTION

[0060] Figure 1 and Figure 2 An exemplary embodiment of an intake valve 1 according to the invention is shown. Figure 1 The valve shown is relative to Figure 2 The illustration in FIG. 1 is rotated 90° about the adjustment axis V. The inlet valve 1 has a gas channel unit 2, which in turn has an inlet 21, an outlet 22 and an inner volume 23, wherein the inner volume 23 can be freely connected to the inlet 21 and the outlet 22 or connect them. The gas channel unit 2 has a sealing surface 24 in the inner volume 23.

[0061] The inlet valve 1 also has an adjustment device 3, which has an adjustment unit 31 and a valve disc 32, wherein the adjustment unit 31 extends into the inner volume 23 and is adjustably mounted in the adjustment device 3 outside the gas channel unit 2. The valve disc 32 is arranged in the inner volume 23 and can be moved by the adjustment device 3 to a closed position, in which the valve disc 32 abuts against the sealing surface 24, thereby preventing the passage of gas. By means of the adjustment device 3, the valve disc can also be moved to an open position, in which the valve disc 32 is spaced apart from the sealing surface 24, thereby allowing the passage of gas.

[0062] The adjusting device 3 also has a preload or reset element 34 in the form of a spring. The spring 34 is arranged in the adjusting device 3 in a preloaded manner so that it exerts a force in the direction of the valve seat and presses the adjusting unit 31 or the valve disk 32 against the sealing surface 24, i.e. in the closing direction S.

[0063] By prestressing the spring or springs, the valve disk 32 is pressed against the sealing surface 24 in the closed position. Here, a sealing ring 33 serves as a gas-tight seal. The sealing ring consists in particular of an elastomer, a thermoplastic, a metal or the like, can have a shape adapted to the shape of the valve disk (e.g. an O-ring), or can be vulcanized onto the valve disk.

[0064] The sealing ring can be arranged on the valve disk 32 (as shown here) or also on the sealing surface 24 (in other embodiments).

[0065] In addition, the adjusting device 3 has a pneumatic drive cylinder 35 for applying an opening force opposite to the preload force, thereby causing the valve disc 32 to generate an opening movement. In the illustrated embodiment, the drive cylinder 35 has two pistons 36a and 36b, wherein the pistons 36a and 36b (or at least one of the pistons 36a) are connected to the adjusting unit 31, and the opening movement of the adjusting unit 31 can be generated by applying pressure to the drive cylinder 35.

[0066] In the embodiment shown, the preload element 34 interacts with the piston 36 a and presses it in the closing direction S.

[0067] The drive cylinders or pistons 36a and 36b may be pressurized via two compressed air outlets 39a and 39b, respectively, which are connected to external pneumatic valves.

[0068] The invention also relates to embodiments in which the drive cylinder 35 has only one piston or more than two pistons (not shown), wherein the pistons are arranged to open the valve by pressurization.

[0069] The inlet valve 1 also has a flexible sealing element 25 which, in the example shown, is designed as a diaphragm, in particular a metal diaphragm. The sealing element is connected to the gas channel unit 2 and the regulating unit 31 so as to seal the inner volume 23 .

[0070] The membrane 25 designed as a flexible sealing element provides a flexible seal of the inner volume relative to the regulating device 3. For this purpose, the membrane 25 is connected on the one hand to the gas channel unit 2 and on the other hand to the regulating unit, here to the valve disk 32 or the stem.

[0071] The regulating device 3 has a limit element 37, which provides a limit point 38, which limits the adjustability of the regulating unit 31 along the regulating axis V in the opening direction O. In this case, the shape and installation method of the limit element 37 make it possible to change the position of the limit point 38 along the regulating axis V by operating the limit element 37. The position of the limit point 38 defines the maximum opening degree or valve stroke of the valve.

[0072] In particular, the stop point 38 is provided by the underside or the lower edge of the stop element 37 .

[0073] In the context of the present invention, the operation on the limiting element 37 particularly refers to the movement, displacement, rotation, etc. of the limiting element 37 .

[0074] In the embodiment shown, the intake valve 1 is in the open position. At this time, the piston 36a is in contact with the limiting element 37, in particular with the lower side of the limiting element 37, and therefore cannot move further in the opening direction O. Since the adjustment unit 31 is connected or coupled to the piston 36a, the adjustment of the adjustment unit 31 or the valve disc 32 is also limited accordingly.

[0075] The intake valve 1 further comprises a motor 40. The motor 40 can be designed as a drive device 40, for example as an electric motor, a servomotor or a stepper motor. The operation of the motor 40 can be controlled in particular by the control and processing unit 50. For example, a certain number of motor revolutions and their direction of rotation can be executed in a controlled manner. The motor 40 should not be understood as a drive device or a drive cylinder for realizing a valve movement (opening and closing).

[0076] The motor 40 is coupled to the stop element 37. In the embodiment shown, a coupling element 41 is provided, which is connected to the stop element 37 on its underside via a pin. In the example shown, the coupling element 41 is designed as a gear. Here, the pin is located in a corresponding recess of the stop element 37 and is fixed by a screw connection. Here, the pin is clamped in the recess by a screw 42.

[0077] The coupling element 41 is connected to the motor 40 on its upper side, in particular to the motor shaft 43 of the motor 40. The motor shaft 43 is embedded in a groove of the coupling element 41. Here, the motor shaft 43 can have an external thread, and the groove of the coupling element 41 can have an internal thread corresponding and matching therewith. The coupling element 41 is arranged at least largely in a rotationally fixed manner relative to the motor 40. The motor shaft 43 can be formed at least partially as a threaded rod or a screw.

[0078] Due to the coupling arrangement of the motor 40 , the coupling element 41 and the stop element 37 , the stop element can be moved along the displacement axis V by operating the motor 40 , ie, rotating the motor shaft 43 . Therefore, the position of the stop point 38 can be changed along the adjustment axis V.

[0079] In an alternative embodiment (not shown here), the coupling element 41 and the limiting element 37 can be integrally formed, or the limiting element 37 can be directly connected to the motor 40. Alternatively, the coupling element 41 and the limiting element 37 can be connected in other ways known to those skilled in the art, such as gluing, welding or brazing.

[0080] The inlet valve 1 also has a fixing element 45, by which the motor 40 is fixed. For example, the motor 40 can be fixed by screws on the fixing element 45. In an alternative embodiment (not shown), the motor 40 can be integrated into the adjustment device 30 or the valve housing.

[0081] Connection devices may be provided for the gas inlet 21 and the gas outlet 22. The pipeline leading to the gas source and the pipeline leading to the vacuum processing chamber may be connected via these connection devices.

[0082] Figure 3 The gas channel unit 2 is shown in detail, in particular the adjustable valve disk 32 and the flexible sealing element 25, which in the embodiment shown is clamped between the gas channel unit 2 and the regulating device 3, or between the gas channel unit 2 and a corresponding component 10. This clamping can be achieved, for example, by a screw connection.

[0083] The cooperation of the flexible sealing element 25 with the adjustment unit 31 can also be achieved by clamping. A person skilled in the art is familiar with a large number of design options for connecting the sealing element to the adjustment unit so that the valve disk remains adjustable in the inner volume 23.

[0084] The control and processing unit 50 has a regulating function for regulating the position of the limit point 38 by controlled operation of the motor 40. To this end, reference information, such as set pressure, set temperature, set flow, etc., is processed and compared with corresponding actual information. Based on the comparison (regulation information), such as the deviation of the actual value and the set value obtained therefrom, the limit element 37 can be adjusted by a corresponding distance, thereby re-adjusting the position of the limit point 38.

[0085] For example, the flow through the valve 1 in the open position can be measured and if there are any deviations from the set flow, the maximum opening cross section of the valve can be readjusted. As an alternative to direct flow measurement, the density and / or temperature or pressure or differential pressure of the fluid can be determined and the flow of the fluid can be inferred from the corresponding measured variables, in particular the actual fluid flow can be calculated based on these variables.

[0086] The control and processing unit 50 may also or alternatively comprise a compensation function for compensating for a position deviation relative to a set position. In this case, it may first be checked whether a position deviation exists, for example by determining the external position of the valve disk 32 or by measuring the flow in the open position, for example when the adjustment unit 31 or the piston 36 strikes the stop element (37).

[0087] If a position shift is detected, the characteristics of the shift, in particular the amount and / or direction of the shift, can be determined. Based on the determined characteristics, the position of the stop point can then be readjusted, in particular in such a way that the desired nominal position is reached when in the open position.

[0088] In particular, the control and processing unit 50 is also connected to the pneumatic valve and is able to control the opening and closing of the air inlet valve.

[0089] Another advantage of the inlet valve according to the invention is that in the first partial volume freely accessible to the inlet opening 21, a supply of gas can be accumulated, so to speak, which can be fluidically and suddenly transferred to the second partial volume connected to the outlet opening when the inlet valve 1 opens. Taking into account these fluid dynamic advantages, the dimensions of the inlet valve according to the invention are also very small.

[0090] The valve disc 32 shown throughout the figures has an upper and lower axial portion (hollow shaft section). In other embodiments, the valve disc 32 may be a mere disc, in which case the upper and lower portions of the valve disc 32 may be replaced by a simple hollow shaft that is axially sealed relative to the disc. Furthermore, the valve disc 32 shown throughout the figures is open in the direction of gas flow, i.e., adjusted from top to bottom according to the figures. However, in other exemplary embodiments, the relevant components may also be designed and arranged so that the valve disc presses on the sealing surface from above in the closed position and moves upwards in the open position.

[0091] Although the present invention has been explained according to the preferred embodiment of the present invention, many other changes and variations may be made without departing from the scope of the present invention. Therefore, the appended claims are intended to cover these changes and variations included in the actual scope of the present invention.

Claims

1. An inlet valve (1) for controlling fluid to enter a vacuum processing chamber, wherein: The air intake valve (1) comprises: - a gas channel unit (2), the gas channel unit having a gas inlet (21), a gas outlet (22) and an inner volume (23) connecting the gas inlet (21) and the gas outlet (22), wherein the gas channel unit has a sealing surface (24) in the inner volume (23); - an adjusting device (3), the adjusting device comprising an adjusting unit (31), wherein the adjusting unit (31) extends into the inner volume (23) and is adjustably mounted along an adjusting axis in the adjusting device (3) outside the gas channel unit (2), wherein the adjusting unit (31) comprises a valve disc (32) arranged in the inner volume (23), wherein the valve disc (32) can be moved by the adjusting device (3) in a closing direction (S) to a closed position, in which the valve disc (32) abuts against the sealing surface (24) and thereby prevents a gas flow, and wherein the valve disc can be moved by the adjusting device (3) in an opening direction (O) to an open position, in which the valve disc (32) is spaced apart from the sealing surface (24) and thereby allows a gas flow; and - a flexible sealing element (25) which is connected to the gas channel unit (2) and the regulating unit (31) and seals the regulating unit (3) from the inner volume (23); in: - the adjusting device (3) has a pneumatic drive cylinder (35) having at least one piston (36a), wherein the piston (36a) is connected to the adjusting unit (31) and can generate an opening force in the opening direction (O) by pressurizing the drive cylinder (35); Features: - the adjustment device (3) has a limit element (37), the limit element (37) provides a limit point (38), the limit point limits the adjustability of the adjustment unit (31) along the adjustment axis (V) in the opening direction (O); and - The shape and installation method of the limiting element (37) enable the position of the limiting point (38) along the installation axis (V) to be changed by operating the limiting element (37), wherein the position of the limiting point (38) defines the maximum opening degree of the valve.

2. The air intake valve (1) according to claim 1, wherein: - the adjusting device (3) has a prestressing element (34) which is arranged and interacts with the adjusting unit (31) in such a way that a prestressing force is applied which presses the valve disk (32) in the closing direction (S); and - Pressurizing the drive cylinder (35) generates an opening force in the opening direction (O) which is opposite to the preload force.

3. The air intake valve (1) according to claim 1 or 2, wherein: The intake valve (1) has a controllable drive device (40), and the drive device (40) is connected or coupled to the limit element (37) in such a way that the position of the limit point (38) can be changed by the drive device (40).

4. The air intake valve (1) according to claim 3, wherein: The drive device (40) is designed as an electric motor, a piezoelectric element or an actuator based on the magnetic suspension principle. The electric motor is in particular a stepping motor.

5. The intake valve (1) according to any one of claims 3 or 4, wherein: The intake valve (1) comprises a control and processing unit (50) which is configured to control the actuator (40).

6. The air intake valve (1) according to claim 5, wherein: The control and processing unit (50) comprises an adjustment function for adjusting the position of the limit point (38), wherein the adjustment function is configured to perform the following steps during operation: - Processing of reference information; - Processing of actual information; - comparing the reference information with the actual information; - deriving adjustment information based on said comparison; and - using the adjustment information to adjust the position of the limit point, in particular automatically.

7. The air intake valve (1) according to claim 6, wherein: The actual information includes information on fluid properties, in particular, the composition, properties or type of the fluid, and the reference information provides a correspondence between the fluid properties and the corresponding positions of the limit points.

8. The air intake valve (1) according to claim 6 or 7, wherein: The reference information comprises information about a desired pressure of the fluid, and the actual information indicates a current fluid pressure, in particular wherein the intake valve (1) comprises at least one pressure sensor for determining the fluid pressure.

9. The air intake valve (1) according to any one of claims 6 to 8, wherein: The reference information comprises information about a set temperature of the fluid, and the actual information indicates a current fluid temperature, in particular wherein the intake valve (1) comprises a temperature sensor for determining the temperature of the fluid.

10. The air intake valve (1) according to any one of claims 6 to 9, wherein: The reference information comprises information about a set flow coefficient of the fluid, and the actual information indicates a current flow coefficient of the fluid, in particular wherein the intake valve (1) comprises a flow measurement unit for determining the flow coefficient of the fluid.

11. The air intake valve (1) according to any one of claims 6 to 10, wherein: The reference information comprises information about a set flow coefficient, and the actual information indicates density and / or temperature or pressure difference of the fluid, in particular wherein the fluid flow coefficient of the fluid can be derived as the actual information from the density and / or temperature of the fluid and / or from the pressure difference.

12. The air intake valve (1) according to any one of claims 5 to 11, wherein: The control and processing unit comprises a compensation function for compensating for a position deviation relative to a desired position, wherein the compensation function is configured to perform the following steps when run: - Verify if there is a position offset; - if a positional offset exists, determining or deriving an expression for said positional offset, in particular the amount and / or direction of said positional offset; and - Tracking the position of the limit point, in particular changing the position of the limit point so that the set position is reached when in the open position.

13. The air intake valve (1) according to claim 12, wherein: The position offset is a position deviation of the valve disc (32) in the open position, or a position deviation of the limit point (38) relative to a corresponding set position of the valve disc or the limit point.

14. The air intake valve (1) according to claim 12 or 13, wherein: Checking for the presence of the position offset or determining the expression for the position offset is done in the following way: - by position measurement or flow measurement; - by determining the temperature of said intake valve; or - based on the number of opening cycles performed by said intake valve.

15. Inlet valve (1) according to any one of the preceding claims, wherein: - the pneumatic drive cylinder (35) has a further piston (36b), and the pistons (36a, 36b) each define a respective drive internal volume; - Each of the actuating inner volumes is connected to a corresponding compressed air channel, and the compressed air channels are arranged in such a way that pressurizing the actuating inner volumes through the compressed air channels can adjust the piston (36a, 36b) in the opening direction (O), thereby enabling the valve disc (32) to move to the open position.

16. Inlet valve (1) according to any one of the preceding claims, wherein The sealing surface (24), the valve disc (32) and the sealing element (25) have a circular cross section, wherein the inner volume (23) is at least partially cylindrical and wherein the sealing surface is formed by a shoulder in the inner volume.

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