Smooth pneumatic vacuum valve

Abstract

The present invention relates to a vacuum transfer valve (1) having a valve wall (8) having an opening (2) and a valve seat (3) connected around the opening (2), a closing plate (4) having a closing side for closing the opening (2) in a hermetic manner, and a driving unit (10) coupled to the closing plate (4) by a valve rod (5), wherein the closing plate (4) is configured to be movable from an open position (O) where the closing plate (4) releases the opening (2), to a closed position (C) where the closing side of the closing plate (4) is pressed against the valve seat (3) to close the opening (2) in a hermetic manner, and then back to an open position. The driving unit (10) comprises a first pneumatic actuator (11) coupled to the valve rod (5) and configured to provide mobility of the closing plate (4) in a first direction, a second pneumatic actuator (14) coupled to the valve rod (5) and configured to provide mobility of the closing plate (4) in a second direction, a first pressure sensor (13) arranged and configured to measure the first operating pressure of the first pneumatic actuator (11), a second pressure sensor (16) arranged and configured to measure the second operating pressure of the second pneumatic actuator (14), a first fluid flow controller (12) arranged and configured to provide a prescribed flow of working fluid to or from the first pneumatic actuator (11), and a second fluid flow controller arranged and configured to provide a prescribed flow of working fluid to or from the second pneumatic actuator (14). Includes a controller (15).

Description

Technology Field

[0001] The present invention relates to a pneumatically driven vacuum valve that provides smooth and uniform movement of the valve closing portion. Background Technology

[0002] Vacuum applications are typically performed in vacuum chamber systems. These applications are carried out in areas, such as IC, semiconductor, or substrate manufacturing, where they must be performed in a protected atmosphere free from contaminant particles as much as possible.

[0003] A vacuum chamber system is provided specifically to accommodate a semiconductor element or substrate to be processed or produced and comprises at least one evacuable vacuum chamber having at least one vacuum chamber opening, through which the semiconductor element or other substrate can be guided in and out of the vacuum chamber. For example, in a production plant for semiconductor wafers or liquid crystal substrates, high-sensitivity semiconductor or liquid crystal elements pass through several process vacuum chambers sequentially, wherein each component located within the process vacuum chamber is processed by a processing device.

[0004] The process chamber typically has at least one transfer valve whose cross-section is adapted to the substrate and the robot, through which the substrate can be introduced into the vacuum chamber and, if necessary, removed after the intended processing. Alternatively, a second transfer valve may be provided, through which the processed substrate is removed from the hermetically closed chamber.

[0005] Additionally, the processing system may include one or more peripheral units specifically used to control or regulate the flow of fluid to and / or from the vacuum chamber. The peripheral units may be provided by a control valve located between the vacuum chamber and a vacuum source or another vacuum chamber, or by a gas inlet valve arranged upstream to provide a specific type and amount of fluid to the vacuum chamber, e.g., a mass-flow controller.

[0006] For example, a substrate to be processed, such as a wafer, is guided by a properly designed and controlled robotic arm, which can be guided through an opening of a process chamber provided by a transfer valve. The process chamber is then loaded by holding the substrate with the robotic arm, introducing the substrate into the process chamber, and placing the substrate within the chamber in a prescribed manner. Accordingly, the process chamber is emptied.

[0007] Since transfer valves (vacuum slide gate valves) are used primarily in the production of high-sensitivity semiconductor components, particle generation caused by valve operation and the number of free particles in the vacuum region of the valve chamber must be kept as low as possible. Particle generation is primarily the result of friction caused by, for example, metal-to-metal contact and wear.

[0008] Sealing can be created, for example, through a seal arranged on the closed side of a closing plate (valve closing part)—whereby the seal is pressed onto the valve seat extending around the opening—or through a ring seal on the valve seat—whereby the closed side of the closing disc is pressed against the ring seal. Different sealing devices are known from the prior art, for example, from U.S. 6 629 682 B2 (Duelli). A material suitable for a ring seal is an elastic sealing material known, for example, by the trade name Viton®.

[0009] Because the seals used undergo excessively high levels of wear or fail when pressurized with excessively high forces, valves are designed so that differential pressure cannot act on the seal or acts only within a limited range. The seal must be pressurized as uniformly as possible along its path, which requires uniform contact pressure of the valve disc against the valve seat across the entire contact area. In particular, transverse stress on the seal must be kept as low as possible. In the case of transverse stress (transverse to the normal direction of the seal), there is a risk that (for example, in the case of an O-ring seal) the seal may tear from its mounting point, particularly in the fixed groove, or that the sealing material may be damaged and particles generated.

[0010] Different embodiments of vacuum valves, in particular their actuation technology, are known from the prior art and are intended to increase the life of the seal in use and also provide improved process reliability.

[0011] This is typically achieved by a specific motion profile of the valve closing portion of an individual transfer valve (slide gate valve). In the first step, the valve closing portion, particularly the closing plate or valve disc, particularly the L-shape, as known, for example, from US 6,416,037 (Geiser) or US 6,056,266 (Blecha), slides linearly over the opening substantially parallel to the valve seat without any contact between the valve closing portion and the valve seat during this process. In the second step, the valve closing portion is pressurized against the valve seat through its closing side so that the opening is closed in a hermetic manner.

[0012] The described 2-stage movement provides substantially only vertical pressure of the seal without lateral stress on the seal.

[0013] The closing movement of this slide gate valve, which occurs in two stages, can be achieved by different mechanisms. For example, a closing plate mounted on two connecting rods is connected to a driving mechanism via the connecting rods, and the driving mechanism enables the substantially parallel sliding of the closing disc over the opening to be closed due to a substantially linear movement along the axis of the connecting rods. By the same driving mechanism, by pivoting the connecting rods, it is possible to pivot the closing disc, which is positioned substantially parallel to the valve seat at a distance opposite the opening, toward the valve seat and press the closing disc substantially perpendicularly to the valve seat. It is also possible to use only one connecting rod instead of two. It is also possible to use more than two connecting rods.

[0014] A driving mechanism that enables both substantially linear sliding of the closing disc over the opening and substantially vertical pressing of the closing disc against the valve seat following around the opening is known, for example, from US 64 431 518 B1, US 5 415 376 A, US 5 641 149 A, US 6 045 117 A, US 5 934 646 A, US 5 755 255 A, US 6 082 706, US 6 095 180 and US 6 629 682 B2.

[0015] US 5 769 952 discloses an alternative approach. The valve includes a mechanism that provides a change in the direction of movement of the valve closure by moving the valve rod in only one direction. Thus, since the connecting rod only needs to slide linearly, the advantage of this type of slide gate valve is the actuation of a relatively simple design. US 2008 / 0083897 A1 also discloses a mechanism that provides sequential longitudinal movement of the valve closure in two directions.

[0016] By providing movement of the valve closing portion first in the direction of the valve rod and second in a direction basically perpendicular to the first direction, the valve closing portion can be moved closer and further away in a direction parallel to the surface normal of the valve seat, thereby providing closing and opening of the valve opening. This results in preventing particle generation.

[0017] However, as a disadvantage, as mentioned, sequentially moving the valve closing portion in two directions leads to a relatively long operating period to open or close the valve. Additionally, the proposed mechanism for switching the direction of movement using a single drive unit is relatively complex, and in the event of maintenance or damage, highly skilled personnel are required to enable additional operation of the valve.

[0018] An additional disadvantage of the aforementioned transfer valve is that the implemented motion profile, particularly the pressure level between the valve disc and the valve seat, is always the same. This applies not only when closing the valve for maintenance purposes, but also during regular processing cycles where this pressure is typically lower than during maintenance. Consequently, the sealing material is subjected to more stress than required from a process perspective. Therefore, the lifespan of the sealing material is shortened accordingly. The problem to be solved

[0019] Therefore, the objective of the present invention is to provide an improved pneumatic vacuum valve for vacuum applications that reduces or avoids the above disadvantages.

[0020] In particular, the object of the present invention is to provide an improved pneumatic vacuum valve having an improved pneumatic operating system that enables reliable and rapid movement of the valve closing portion.

[0021] In addition, the object of the present invention is to provide an improved vacuum valve that provides flexibility in moving the valve closing portion and pressurizing the valve closing portion against the valve seat.

[0022] These objectives are achieved by implementing the characteristic elements of the independent claims. Features that further develop the invention in an alternative or advantageous way can be found in the dependent claims. means of solving the problem

[0023] The approach according to the present invention proposes providing at least two individually controllable pneumatic actuators to simultaneously move the valve closing of a vacuum transfer valve in at least two (orthogonal) directions to provide smooth and uniform motion of the valve closing. Additionally, the approach enables the motion profile of the valve closing to be adjusted as a function of the desired application.

[0024] The control of a pneumatic actuator is realized by having a fluid flow controller connected to the actuator. The fluid flow controller provides to pressurize the actuator in a specified manner by applying a specified amount of working fluid per hour.

[0025] The fluid flow controller may be a control valve configured to control and provide a specified pressure or pressure change in an actuator, particularly in a pneumatic cylinder of the actuator or at least one chamber of a pneumatic cylinder. Alternatively or additionally, the control valve may be configured to control and provide a specified fluid flow or flow rate or change therefrom in the pneumatic actuator.

[0026] The fluid flow controller may be a proportional control valve capable of providing a defined fluid flow as a function of each applied control signal.

[0027] Such fluid flow controllers may provide a defined fluid flow to the first and / or second pneumatic actuators or a defined fluid pressure of the individual pneumatic actuators as a function of an applied control signal, wherein the control signal may provide a control voltage or a control current. Additionally, the adjustment of the first control signal may include adjusting the control voltage or control current to provide movement of the moving member of the actuator according to movement information.

[0028] Feedback regarding pressure in one of the actuators can be provided by individual sensors.

[0029] The present invention relates to a vacuum transfer valve having a valve wall having an opening and a valve seat extending around the opening, and a closing plate (valve closing part) having a closing side for closing the opening in a hermetic manner.

[0030] The vacuum transfer valve also includes a drive unit configured such that the valve rod, that is, a type of valve guide configured to hold and move the closing plate, is coupled to the closing plate, and the closing plate is movable from an open position where the closing plate releases the opening (no contact between the closing plate and the valve seat), to a closed position where the closing side of the closing plate is pressed against the valve seat to close the opening in a hermetic manner, and then back to an open position.

[0031] The driving unit includes a first pneumatic actuator coupled to a valve rod and configured to provide mobility of the closing plate in a first direction. Additionally, the driving unit includes a second pneumatic actuator coupled to a valve rod and configured to provide mobility of the closing plate in a second direction.

[0032] The first direction may be linear or longitudinal, or alternatively a rotational direction, for example, movement of the closed plate around individual rotation axes. The second direction may also be linear or longitudinal, or alternatively a rotational direction, for example, movement of the closed plate around individual rotation axes.

[0033] At least one of the pneumatic actuators may include a cylinder separated into two chambers by a moving member. The moving member may preferably be a piston. A stem may be connected to the moving member and extend outside the internal volume of the cylinder. The stem may provide a valve rod and may be configured to provide operation of a connected valve closure to be moved.

[0034] The pneumatic actuator may additionally include a first fluid passage that enables fluid flow into and out of the first or second chamber of the actuator.

[0035] Additionally, at least one pneumatic actuator may include a restoring element, in particular a spring. The restoring element may be connected to a moving member and apply a restoring force to the moving member.

[0036] The driving unit includes a first pressure sensor arranged and configured to measure a first operating pressure of a first pneumatic actuator and a second pressure sensor arranged and configured to measure a second operating pressure of a second pneumatic actuator.

[0037] The pressure sensor is preferably arranged to measure the pressure of at least one chamber of the actuator.

[0038] At least one of the pressure sensors can provide pressure feedback regarding the pressure affecting the moving member.

[0039] In an alternative embodiment, at least one of the pressure sensors may be a flow meter for measuring fluid flow from and / or to each connected actuator. In an alternative embodiment, at least one of the pressure sensors may be a flow rate sensor.

[0040] The driving unit includes a first fluid flow controller arranged and configured to provide a defined flow of working fluid to or from a first pneumatic actuator and a second fluid flow controller arranged and configured to provide a defined flow of working fluid to or from a second pneumatic actuator.

[0041] The configuration of the vacuum transfer valve described above enables the control of the motion of the closing plate (valve closing portion) in a single, uniform motion process, without the need to apply more than one separate motion stage or sequence. This is because the closing plate moves in two directions simultaneously, allowing it to essentially reach the end position of each direction at the same time. Furthermore, by controlling the actuator pressure, the pressure applied to the closing plate against the valve seat can be adjusted according to the required application criteria, resulting in less stress and wear on the sealing material. Consequently, the sealing offers a longer lifespan due to reduced wear.

[0042] In one embodiment, a second pneumatic actuator may be coupled to a valve rod and a closing plate. By this arrangement, individual movement of the closing plate in a second direction may be provided.

[0043] In one embodiment, a second pneumatic actuator is coupled to a valve rod to apply motion in a second direction to the valve rod, thereby providing individual movement of the closing plate.

[0044] In one embodiment, the first and second pneumatic actuators are constructed as an integrated actuator unit to provide bidirectional motion.

[0045] In one embodiment, the first fluid flow controller and the second fluid flow controller may be sub-units of the overall fluid flow controller, wherein the overall fluid flow controller provides pressurization of the first and second pneumatic actuators.

[0046] In one embodiment, the valve rod can support the closing plate.

[0047] According to an embodiment, a second pneumatic actuator may be coupled to the valve rod and the closing plate to provide mobility of the closing plate relative to the valve rod. With this arrangement, direct operation of the closing plate in a direction parallel to the opening axis of the valve opening may be provided, which allows approach to and contact with the valve seat in a normal direction.

[0048] In an embodiment, the vacuum transfer valve may include a control unit configured to provide movement of a closing plate according to a motion profile by controlling a first fluid flow controller and a second fluid flow controller. The control unit may be implemented to generate individual control signals that provide individual operation of the fluid flow controllers when applied.

[0049] The motion profile may include, for example, information regarding the (nominal or target) position of the closing plate in one direction or each direction over time during a single processing cycle. The motion profile may be directly related to or include individual pressure profiles to be applied to individual actuators to provide the desired motion.

[0050] At least the operating speed, operating acceleration, and / or sealing force (the force applying pressure to the closing plate against the valve seat) for the closing plate can be defined by this motion profile.

[0051] In particular, the control unit may be configured to control the first fluid flow controller and the second fluid flow controller as a function of pressure information provided by the first pressure sensor and the second pressure sensor.

[0052] By measuring the pressure of each pressurized chamber of a pneumatic actuator, that is, the actuator, direct feedback of the fluid flow is provided, allowing for precise control of the actuator's pressurization according to the motion profile used.

[0053] In one embodiment, control of the first fluid flow controller and the second fluid flow controller is provided so that the motion of the closing plate may include simultaneous movement in the first direction and the second direction. Accordingly, individual motion profiles may include pressurization commands for both fluid flow controllers or movement commands for both actuators.

[0054] In one embodiment, a first pressure profile may be provided to control a first fluid flow controller, and a second pressure profile may be provided to control a second fluid flow controller.

[0055] According to one embodiment, the control unit may be configured to provide a set of motion profiles that each provide an overlap of the movement of the closing plate in a first direction and the movement of the closing plate in a second direction, wherein at least two of the set of motion profiles may be individually selected for the closing plate to follow.

[0056] Accordingly, a motion profile matching the required application parameters can be automatically or manually selected by an operator to provide optimized motion behavior for each valve closure.

[0057] In one embodiment, the control unit may include a motion profile planner that provides for generating or adjusting a motion profile by adapting the control of at least one of the first fluid flow controller and the second fluid flow controller—at execution. This function provides for individually generating an appropriate motion profile for a specific application.

[0058] In particular, the motion profile planner may include non-adaptive default conditions to provide valve integrity when driving the valve with a generated or adjusted motion profile. The default conditions are,

[0059] · Motion offset regarding the amount of movement of the closing plate in the first direction relative to the second direction,

[0060] · Limitation of movement speed of the closed plate,

[0061] · Limiting the rate of change of pressure of the working fluid, in particular limiting the acceleration of the closed plate, and

[0062] · It may include at least one of the limitations regarding the pressurization of the closing plate on the valve seat.

[0063] For example, the motion offset may be defined not only to partially provide simultaneous movement in the first and second directions, but also to have a separated movement, specifically to prevent the closing plate from moving in the first direction, i.e., perpendicular to the opening axis, while in contact with the valve seat. Such vertical movement may result in damage to the sealing material of the closing plate.

[0064] Additional basic conditions may be specified to prevent damage caused by unwanted movement of the transfer valve.

[0065] In one embodiment, a digital model of a vacuum transfer valve, in particular a digital twin, is provided, wherein the digital model provides a description or determination of the valve state as a function of pressure information. By processing the pressure information with such a model, the structure and function of the valve can be derived at any point in time.

[0066] The model can be trained to provide (nearly) realistic behavior of the vacuum transfer valve, which means that specific pressure measurements can be performed and assigned to each determined valve state. For example, multiple positions of the closing plate can be determined (e.g., by measurement), and corresponding pressure values ​​can be derived and assigned to those positions.

[0067] The control unit may be further configured to derive a first control signal for controlling a first fluid flow controller and a second control signal for controlling a second fluid flow controller based on a digital model and pressure information.

[0068] In particular, the control unit can be configured to derive the position of the closed plate as a function of pressure information based on a digital model.

[0069] Therefore, the digital model enables the derivation of position information based on pressure values ​​measured in real time. Thus, a type of motion tracking can be provided to monitor the actual valve state (state or position of the closing plate) and compare it with a desired target state.

[0070] In one embodiment, the vacuum transfer valve may include an environmental condition sensor for measuring environmental parameters, in particular a temperature sensor or a humidity sensor, and the control unit may be configured to process the environmental parameters in the process of providing a description or determination of the valve state, in particular, wherein a digital model or model parameters are adapted. This additional information is provided to model the transfer valve more precisely and to derive the valve position with corresponding high precision.

[0071] In one embodiment, the control unit may be configured to monitor the progression of the valve state during the motion of the closing plate based on a digital model and pressure information (e.g., real-time tracking of the closing plate), compare the monitored progression of the valve state with a reference valve state (known and / or stored) associated with the (nominal or target) motion profile of the closing plate, and derive valve operation information based on the comparison.

[0072] This approach provides monitoring of valve operation and generates and provides individual information (warnings) to the operator so that any malfunctions can be continuously recognized.

[0073] In one embodiment, the control unit may be configured to determine a long-term trend based on monitoring the progress of the valve state during a plurality of control cycles, derive valve state information based on the long-term trend, compare the valve state information with a predefined threshold value, and generate maintenance information based on the comparison.

[0074] This derived information regarding long-term trends, for example, long-term drift of vacuum valve control, can provide individual information regarding possible wear or leakage (for example, in relation to the working fluid supply), and based thereon, maintenance of the valve can be planned or initiated. Brief explanation of the drawing

[0075] The valve according to the present invention is described below in detail with reference to specific exemplary embodiments schematically illustrated in the drawings merely as examples, and additional advantages of the present invention are also discussed. In detail, in the drawings: FIGS. 1a to 1c illustrate embodiments of a transfer valve known from the prior art. Figure 2 illustrates the motion profile of a vacuum valve known from the prior art. FIGS. 3a to 3c illustrate embodiments of a vacuum transfer valve according to the present invention. FIG. 4 illustrates the motion profile of a vacuum transfer valve according to the present invention. FIGS. 5A and FIGS. 5B illustrate the pressure profile and motion profile of a vacuum transfer valve according to the present invention. Specific details for implementing the invention

[0076] FIGS. 1a to 1c illustrate embodiments of a vacuum transfer valve (1) according to the prior art, shown in different closed positions.

[0077] The vacuum valve (1) includes a rectangular plate-shaped valve closure (4) (closing plate, valve disc) which has a sealing surface (6) for hermetically closing the opening (2). The opening (2) has a cross-section corresponding to the valve closure (4) and is formed in a wall (8). The wall (8) may be, for example, a wall of a vacuum process chamber. The opening (2) is surrounded by a valve seat, which also provides a sealing surface (3) corresponding to the sealing surface (6) of the valve closure (4). The sealing surface (6) of the valve closure (4) surrounds the valve closure (4) and comprises a sealing material (seal). At the closed position S (Fig. 1c), the seal is compressed between the sealing surfaces (6 and 3).

[0078] The opening (2) connects the first gas region L located to the left of the wall (8) to the second gas region R located to the right of the wall (8). The wall (8) is formed, for example, by the chamber wall of a vacuum chamber. Then, the vacuum valve (1) is formed by the interaction between the chamber wall (8) and the valve closing part (4).

[0079] It will be understood that the valve seat, together with the first sealing surface (3), may be formed as a valve component structurally fixed to the valve (1), and may be arranged, for example, in the chamber opening, for example, screw-fixed. At least both of these embodiments are included in the present invention.

[0080] As illustrated herein, the valve closing portion (4) may be arranged on an adjusting arm (5) (valve rod), the adjusting arm (5) being, for example, rod-shaped and extending along a geometric adjustment axis V. The adjusting arm (5) is mechanically coupled to a pneumatic drive unit (7), and the closing portion (4) may be adjusted in a first gas region L on the left side of the wall (8) by adjusting the adjusting arm (5) from an open position O (Fig. 1a) through an intermediate position Z (Fig. 1b) to a closed position S (Fig. 1c) by the pneumatic drive unit (7).

[0081] In the open position O, the valve closing portion (4) is outside the projection area of ​​the opening (2), thereby fully exposing the opening (2).

[0082] By moving the valve closing part (4) linearly in the axial direction in a plane parallel or coaxial with the adjustment axis V and parallel to the wall (8) by the driving unit (7), the valve closing part (4) can be moved from the open position O to the intermediate position Z.

[0083] At this intermediate position Z (Fig. 1b), the sealing surface (6) of the valve closing portion (4) is spaced oppositely to the sealing surface (3) of the valve seat surrounding the opening (2).

[0084] By adjusting in the direction of the opening axis A defined by the opening (2) (here: transverse to the adjustment axis V), that is, in a direction perpendicular to the wall (8) and the valve seat, the valve closing part (4) can be adjusted from an intermediate position Z to a closed position S (Fig. 1c).

[0085] In the closed position S, the valve disc (4) hermetically closes the opening (2) and hermetically separates the first gas region L from the second gas region R.

[0086] In this case, the vacuum valve is opened and closed by the driving unit (7) by L-shaped movement in two directions V and A of the valve closing portion (4) which are perpendicular to each other. Therefore, the valve is also called an L-shaped valve.

[0087] A transfer valve (1) as illustrated is typically provided to seal a process volume (vacuum chamber) and to load and unload the volume. In such applications, frequent switching between the open position O and the closed position S is common. This can lead to increased wear on the sealing surfaces (6 and 3), intermediate seals, and mechanically moved components.

[0088] According to the prior art, such a transfer valve provides valve opening and closing in two stages, namely, moving the valve closing portion (4) along a first axis, and then moving the valve closing portion (4) along a second axis perpendicular to the first axis. Due to the required sequential movement, the valve opening and closing period takes a relatively long time.

[0089] The structural design of the transfer valve (1) provides a single general motion profile, namely, acceleration, velocity, and sealing force are fixed. Consequently, the aforementioned parameters are defined so that the closed state of the valve satisfies the sealing requirements for all application purposes. This results in a sufficiently high level of sealing force (the force with which the valve closure is pressed against the valve seat) when the processing chamber is ventilated, for example, in the case of a chamber cleaning process. However, under vacuum conditions, the sealing force required to close the valve during normal process steps may be significantly lowered to still satisfy individual processing requirements. Consequently, the sealing material is subjected to an excessive load beyond what is necessary, thereby shortening the life of the seal.

[0090] Figure 2 illustrates the motion profile of a vacuum valve according to Figure 1.

[0091] As described above, the driving mechanism of the valve (1) is a 2-axis (vertical-horizontal) motion mechanism, wherein the operation of the valve closing part (4) is performed sequentially, including a defined delay for each axis (since there is no position information), to ensure proper opening and closing of the valve, which in return causes a long operating time.

[0092] These sequential operations are illustrated for the closing process, that is, for changing the valve state from open position O to closed position S. First, the valve closing part (4) moves along the adjustment axis V, which corresponds to a change in the y-position of the closing part (4). After reaching the extended state of the valve rod (5), that is, when the valve closing part comes to the intermediate position Z, the valve closing part (4) moves along the opening axis A, which is perpendicular to the adjustment axis V, until the valve is closed. This second motion part along the opening axis A corresponds to a change in the x-position as illustrated.

[0093] FIGS. 3a to 3c illustrate embodiments of a vacuum transfer valve (1) according to the present invention in different closed positions.

[0094] This embodiment is different from the embodiment of FIG. 1 by having a different driving unit (10).

[0095] The driving unit (10) includes a first pneumatic actuator (11) coupled to a valve rod (5) implemented herein as a valve rod. The driving unit (10) is configured to provide mobility of the closing plate (4) in a first (lengthwise) direction. The first direction is a direction corresponding to the extension of the adjustment axis V, i.e., the direction of movement of the valve rod (5) along the adjustment axis V.

[0096] A first pneumatic actuator (11) is connected to a first fluid flow controller (12), and the first fluid flow controller (12) is arranged and configured to provide a defined flow of working fluid to or from the first pneumatic actuator (11).

[0097] Additionally, the first pressure sensor (13) is arranged and configured to measure the first operating pressure of the first pneumatic actuator (11), that is, the pressure applied to the first pneumatic actuator (11).

[0098] The first pneumatic actuator (11) includes a restoring element (not shown), for example, a spring, which provides a restoring force acting against the operating force applied to the valve rod (5) by the pressurization of the first pneumatic actuator (11).

[0099] In an alternative embodiment (not shown), the first pneumatic actuator (11) may include an additional fluid flow controller connected to the actuator (11) to provide pressurization on the opposite side of the moving member (17) inside the actuator (11). By doing so, reverse movement of the valve closing part in the opposite direction can also be provided and controlled.

[0100] The driving unit (10) also includes a second pneumatic actuator (12) coupled to the valve rod (5) and configured to provide mobility of the closing plate (4) in a second (longitudinal) direction. The second direction is a direction perpendicular to the first direction. Here, the second direction corresponds to an extension of the opening axis A in the closed state S of the valve or is parallel to the opening axis A.

[0101] The second pneumatic actuator (14) is connected to a second fluid flow controller (15) arranged and configured to provide a defined flow of working fluid to or from the second pneumatic actuator (14).

[0102] Additionally, the second pressure sensor (16) is arranged and configured to measure the first operating pressure of the second pneumatic actuator (14), that is, the pressure applied to the second pneumatic actuator (14).

[0103] The second pneumatic actuator (14) may include a spring or an additional fluid flow controller to provide (and control) reverse movement of the valve plate, i.e., reverse movement in the opposite direction to the second direction, as described above for the first actuator.

[0104] The vacuum transfer valve (1) also includes a control unit (20). The control unit (20) is connected to a first fluid flow controller (12) and a second fluid flow controller (15) to control fluid flow through the flow controllers, and is connected to a first pressure sensor (13) and a second pressure sensor (16) to receive pressure information related to the pressure of the actuators (11 and 14).

[0105] The control unit (20) is configured to provide movement of the closed plate (4) according to the motion profile by controlling the first fluid flow controller (12) and the second fluid flow controller (15) as a function of pressure information provided by the first pressure sensor (13) and the second pressure sensor (16).

[0106] The control unit (20) is configured to provide control of the first fluid flow controller (12) and the second fluid flow controller, so that the motion profile includes the simultaneous movement of the closing plate (4) in the first direction and the second direction. That is, the first and second pneumatic actuators are pressurized at least partially simultaneously.

[0107] Consequently, the change of the state of the valve closing part (4) from the valve state or open state O to the closed state (or in another way) can be realized with significantly less time consumption. This is because the valve closing is provided as a single smooth and uniform motion of the closing part (4) without the need for the valve closing to be performed in two separate motion steps. This smooth movement further provides particle generation and reduced vibration due to the smooth opening and closing.

[0108] The controller (20) is further configured to process pressure information to detect a specific position (e.g., a closed position) of the valve closing part (4). By doing so, real-time tracking of the valve closing part (4) can be provided. Based on this, the pressure profile can be adapted to minimize vibration and particle generation in addition to operating other axes simultaneously, thereby reducing the overall operating time.

[0109] In particular, a digital model of the vacuum transfer valve (1), for example, a digital twin, is provided. The digital model provides a description or determination of the valve state as a function of (measured) pressure information. That is, if the pressure of the pneumatic actuator is known, for example, the position of the valve closing part (4) can be derived. The control unit (20) can be configured to derive a first control signal for controlling a first fluid flow controller and a second control signal for controlling a second fluid flow controller, respectively, based on the digital model and pressure information.

[0110] Furthermore, motion or position control of pneumatic cylinders can be performed using only digital twins or models without the use of any real-time feedback position measurements or indicators. Therefore, control can be provided in an open-loop and sensor-less manner.

[0111] To adjust the digital twin to best correspond to actual conditions, environmental information such as temperature or humidity, friction, or other environmental conditions (e.g., by measurement or simulation) can be derived, and model parameters or motion parameters can be adjusted accordingly.

[0112] Based on the digital model and pressure information, the progression of the valve state during the motion of the closing plate (4) can be monitored. By doing so, for example, if the path of the gate (valve closing part) is blocked by an obstacle, the associated early pressure rise can be detected, and by combining it with a digital twin that references the actual position, the unwanted state of the transfer valve can be derived.

[0113] In addition, the progress of the monitored valve state can be compared with a reference valve state related to the motion profile of the closing plate, and valve operation information can be derived based on this comparison.

[0114] Digital models can also be used for predictive maintenance of valves. To this end, long-term trends of valve status or realized motion profiles can be derived based on pressure measurements and the processing of the measured pressures by the digital model. This model-based processing can be performed over multiple processing cycles or periods. The processing results can be compared against each other or against reference values, and trends can be derived based on this. Based on these trends, maintenance of the valves can be planned accordingly.

[0115] Since the operation of the pneumatic actuator can be controlled individually, the motion of the closing plate (4) can be optimized for the specific application to be provided by the valve. Such applications may be, for example, ventilation of a processing chamber or a normal processing step of the chamber. When ventilating the processing chamber, the force required to pressurize the valve closing part (4) against the valve seat (3) must be greater than the individual force required for processing. This is due to the significantly higher pressure difference between the first gas region L and the second gas region R when ventilating the chamber.

[0116] According to the present invention, the pneumatic actuator (11, 14) can be controlled by its fluid flow controller (12, 15), that is, by adjusting the amount of fluid flow to (or from) the pneumatic actuator (11, 14). The pressure of the actuator (11, 14) depends directly on the fluid flow. This means that, for example, the pressure of the pneumatic actuator (14) can be controlled and changed, and the (pressing) force for pressing the valve closing part (4) against the valve seat (3) can also be adjusted.

[0117] The motion profile for the overall motion of the pneumatic actuator (14) or pneumatic actuator (11) or valve may each include the applied pressure level over time.

[0118] Accordingly, the transfer valve (1) can be controlled differently depending on the applied or desired application by, for example, by changing the motion profile or by changing the control parameters processed to control the fluid flow controller (12, 15).

[0119] Accordingly, the control unit may be configured to provide a set of motion profiles that can be provided by the superposition of the movement of the closing plate in a first direction and the movement of the closing plate in a second direction, respectively. At least two of the set of motion profiles may be individually selected to be followed by the closing plate (4). In particular, the motion profiles are associated with individual control parameters that control the fluid flow controllers (12, 15).

[0120] FIG. 4 illustrates the motion profile of a vacuum valve according to the present invention.

[0121] As described above, the driving unit of the valve according to the present invention is a simultaneous 2-axis (vertical-horizontal) pneumatic motion actuator, wherein the operation of the valve closing part (4) must be performed in a single sequence, particularly including the superposition of x-axis and y-axis movements. This provides smooth motion of the valve closing part (4) and smooth closing with a shorter operating time, respectively.

[0122] This simultaneous operation is illustrated for the valve closing process, that is, changing the valve state from open position O to closed position S. The valve closing part (4) is moved along the adjustment axis V corresponding to the change in the y-position of the closing part (4), and is also moved simultaneously in a direction perpendicular to the adjustment axis V and parallel to or corresponding to the opening axis A. The valve closing part (4) essentially reaches the end-position simultaneously in the x-direction and the y-direction. In one preferred embodiment, the movement along the adjustment axis V (y-position) is completed before the movement in the orthogonal direction.

[0123] FIG. 5a illustrates the pressure profile of a pneumatic actuator for controlling motion to close a valve according to the present invention. As can be seen, the pressure level begins to increase with a small slope. Subsequently, the pressure increases more strongly to provide a shorter operating time. In the third motion phase, the pressure increase decreases again to provide smooth contact in order to bring the valve closing part closer to the valve seat.

[0124] FIG. 5b illustrates the corresponding motion profiles of the valve closing part (4) over time in the x-direction and y-direction, that is, in the direction along the adjustment axis V and in the direction perpendicular to the axis V, as a result of applying the pressure profile according to FIG. 5a.

[0125] Motion performance follows the respective pressure profile. This results in a coordinated, fast, yet smooth movement of the valve closure, which also provides smooth valve closure.

[0126] The force applying pressure to the valve closing portion (4) against the valve seat (3) can be adjusted, for example, by increasing the final pressure level overall, particularly in relation to the second pneumatic actuator (14).

[0127] It is understood that the depicted drawings merely schematically illustrate possible exemplary embodiments. Various approaches according to the present invention may also be combined with each other and may be combined with methods and devices of the prior art for pneumatic transfer valve control.

Claims

Claim 1 As a vacuum transfer valve (1), the valve wall (8) having an opening (2) and a valve seat (3) extending around the opening (2), a closing plate (4) having a closing side for closing the opening (2) in a hermetic manner, and the closing plate (4) being coupled to the closing plate (4) by a valve rod (5), and the closing plate (4) □ From the open position (O) where the above-mentioned closing plate (4) releases the above-mentioned opening (2), □ The closing side of the above-mentioned closing plate (4) is pressed against the valve seat (3) to a closing position (C) that closes the opening (2) in a hermetic manner, and □ A driving unit (10) configured to be movable to a re-open position, wherein the driving unit (10) comprises: a first pneumatic actuator (11) coupled to the valve rod (5) and configured to provide mobility of the closing plate (4) in a first direction; a second pneumatic actuator (14) coupled to the valve rod (5) and configured to provide mobility of the closing plate (4) in a second direction; a first pressure sensor (13) arranged and configured to measure a first operating pressure of the first pneumatic actuator (11); a second pressure sensor (16) arranged and configured to measure a second operating pressure of the second pneumatic actuator (14); a first fluid flow controller (12) arranged and configured to provide a defined flow of operating fluid to or from the first pneumatic actuator (11); and the second pneumatic A vacuum transfer valve (1) characterized by including a second fluid flow controller (15) arranged and configured to provide a defined flow of working fluid to or from the actuator (14) or the second pneumatic actuator (14). Claim 2 In claim 1, the second pneumatic actuator (14) is a vacuum transfer valve (1) coupled to the valve rod (5) and the closing plate (4). Claim 3 In claim 1 or 2, the second pneumatic actuator (14) is coupled to the valve rod (5) and the closing plate (4) to provide mobility of the closing plate (4) relative to the valve rod (5), a vacuum transfer valve (1). Claim 4 In any one of claims 1 to 3, the vacuum transfer valve (1) comprises a control unit (20) configured to provide movement of the closing plate (4) according to a motion profile by controlling the first fluid flow controller (12) and the second fluid flow controller (15). Claim 5 In paragraph 4, the control unit (20) is configured to control the first fluid flow controller (12) and the second fluid flow controller (15) as a function of pressure information provided by the first pressure sensor (13) and the second pressure sensor (16), a vacuum transfer valve (1). Claim 6 A vacuum transfer valve (1) in which, in claim 4 or 5, control of the first fluid flow controller (12) and the second fluid flow controller (15) is provided so that the motion of the closing plate (4) includes simultaneous movement in the first direction and the second direction. Claim 7 A vacuum transfer valve (1), wherein, in any one of claims 4 to 6, a first pressure profile is provided to control the first fluid flow controller and a second pressure profile is provided to control the second fluid flow controller. Claim 8 In any one of claims 4 to 7, the control unit (20) is configured to provide a set of motion profiles that each provide an overlap of the movement of the closing plate (4) in the first direction and the movement of the closing plate (4) in the second direction, and at least two of the set of motion profiles can be individually selected to be followed by the closing plate (4), a vacuum transfer valve (1). Claim 9 In any one of claims 4 to 8, the vacuum transfer valve (1) comprises a motion profile planner that provides for generating or adjusting the motion profile by adapting the control of at least one of the first fluid flow controller (12) and the second fluid flow controller (15) when executed. Claim 10 In claim 9, the motion profile planner comprises non-adaptive basic conditions for providing valve integrity when driving the vacuum transfer valve (1) with a generated or adjusted motion profile, wherein the basic conditions comprise at least one of: a motion offset regarding the amount of movement of the closing plate (4) in the first direction relative to the second direction; a limit on the movement speed of the closing plate (4); a limit on the rate of change of pressure of the working fluid, in particular a limit on the acceleration of the closing plate (4); and a limit on the pressurization of the closing plate (4) relative to the valve seat (3). Claim 11 A vacuum transfer valve (1), wherein, in any one of claims 4 to 10, a digital model of the vacuum transfer valve is provided, and the digital model provides a description or determination of valve states as a function of the pressure information, and the control unit is configured to derive a first control signal for controlling the first fluid flow controller and a second control signal for controlling the second fluid flow controller based on the digital model and the pressure information. Claim 12 In claim 11, the control unit (20) is configured to derive the position of the closed plate (4) as a function of the pressure information based on the digital model, the vacuum transfer valve (1). Claim 13 In claim 9 or 12, the vacuum transfer valve (1) comprises an environmental condition sensor for measuring environmental parameters, and the control unit (20) is configured to process the environmental parameters in the process of providing a description or determination of the valve states. Claim 14 In any one of claims 9 to 13, the control unit (20) is configured to: · monitor the progress of the valve state during the motion of the closing plate (4) based on the digital model and the pressure information; · compare the monitored progress of the valve state with reference valve states associated with the motion profile of the closing plate (4); and · derive valve operation information based on the comparison, the vacuum transfer valve (1). Claim 15 In any one of claims 4 to 14, the control unit (20) is configured to determine a long-term trend based on the monitoring of the progress of the valve state during a plurality of control cycles, derive valve state information based on the long-term trend, compare the valve state information with a predetermined threshold value, and generate maintenance information based on the comparison, a vacuum transfer valve (1).

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