Regulating valve, and mass flow controller and flow control method thereof

Abstract

A regulating valve, and a mass flow controller and a flow control method thereof. The regulating valve comprises a valve body assembly, a valve core assembly, and a position detection device, wherein the valve body assembly has a valve port; the valve core assembly comprises a valve core structure, the valve core structure having a sealing surface and being configured to enable the sealing surface to move relative to the valve body assembly in the direction toward or away from the valve port, so as to open or close the valve port and adjust the flow rate of a fluid flowing through the valve port; and the position detection device is configured to detect the position of the sealing surface relative to the valve port. The regulating valve, and the mass flow controller and the flow control method thereof have higher flow control precision and repeatability, meeting the requirements of advanced semiconductor manufacturing processes for control precision and repeatability.

Description

Control valves, mass flow controllers and their flow control methods Technical Field

[0001] This application relates to the field of semiconductor manufacturing, and more specifically, to a regulating valve, a mass flow controller, and a flow control method thereof. Background Technology

[0002] In advanced semiconductor manufacturing processes such as plasma etching and chemical vapor deposition, precise control of the flow rate of process gases entering the reaction chamber is crucial. In these processes, all materials involved in etching or deposition are introduced into the reaction chamber in gaseous form. Even a slight deviation in the flow rate of the introduced process gases (e.g., a 1% deviation) can lead to process failure. Therefore, flow control devices capable of precisely controlling gas flow are particularly important in these processes.

[0003] In recent years, with the development of the semiconductor industry, the size of key semiconductor components has become smaller and smaller, the process window range has become tighter, and the process step time has become shorter. The general requirement for gas flow control devices in high-end semiconductor processes is to control the response time to within 1 second, without overshoot, and to generate accurate flow that does not drift over time and is not affected by downstream pressure fluctuations.

[0004] Current flow control devices mainly employ thermal mass flow controllers and pressure mass flow controllers. Traditional pressure mass flow controllers use pressure sensor feedback signals and have a fast response time, quickly responding to changes in inlet pressure. However, traditional pressure mass flow controllers cannot directly obtain the valve opening, resulting in poor accuracy and repeatability in flow control, which cannot meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability. Summary of the Invention

[0005] This application aims to solve at least one of the technical problems existing in the prior art, and proposes a regulating valve, a mass flow controller and a flow control method thereof, which can improve control accuracy and repeatability.

[0006] To achieve the purpose of this application, a regulating valve is provided, including a valve body assembly, a valve core assembly, and a position detection device, wherein the valve body assembly has a valve port; the valve core assembly includes a valve core structure having a sealing surface, the valve core structure being configured to allow the sealing surface to move relative to the valve body assembly in a direction approaching or away from the valve port, so as to open or close the valve port and regulate the flow rate of fluid through the valve port;

[0007] The position detection device is used to detect the position of the sealing surface relative to the valve port.

[0008] In some embodiments, the position detection device includes a moving component and a parameter detection unit, wherein the moving component is connected to the valve core structure, and the moving component is configured with a variable element whose parameter changes with the movement of the sealing surface;

[0009] The parameter detection unit is used to detect the parameter magnitude of the variable element.

[0010] In some embodiments, the movable component includes a fixed member and a movable member, wherein the fixed member and the movable member constitute the variable element; the fixed member is connected to the valve body assembly; and the movable member is connected to the valve core structure.

[0011] In some embodiments, both the fixing member and the moving member are electrode plates, and the variable element formed by the fixing member and the moving member is a capacitor;

[0012] The parameter detection unit is used to detect the capacitance value of the capacitor.

[0013] In some embodiments, there are two fixing members, both of which are electrode plates and are arranged opposite to each other along the moving direction of the sealing surface, and both are connected to the valve body assembly; the moving member is an electrode plate and is located between the two fixing members, and the variable element formed by the two fixing members and the electrode plate is a first capacitor and a second capacitor, respectively.

[0014] The parameter detection unit is used to detect the size of the first capacitor and the second capacitor.

[0015] In some embodiments, the valve core assembly further includes a valve core mounting member, which is fixedly connected to the valve body assembly and located on the side of the valve body assembly where the valve port is located; the valve core structure includes a valve core rod, which is movably connected to the valve core mounting member and extends along the moving direction of the sealing surface; the sealing surface is located at the end of the valve core rod near the valve port;

[0016] The fixing component is fixedly disposed relative to the valve core mounting component.

[0017] In some embodiments, the valve core mounting member is provided with a through space extending through the valve core mounting member along the moving direction of the sealing surface; the valve core rod is movably inserted through the through space;

[0018] The valve core structure also includes an elastic element that is sealed between the outer peripheral surface of the valve core rod and the inner wall of the through space;

[0019] The fixing member is located on the side of the valve core mounting member opposite to the valve body assembly, and an accommodating space is formed between the fixing member and the valve core mounting member;

[0020] The movable component is fixedly connected to the valve core rod and is at least partially located in the accommodating space.

[0021] In some embodiments, the regulating valve further includes a drive assembly for moving the valve stem;

[0022] The fixing member has a clearance part at the position corresponding to the valve core rod, and the end of the valve core rod away from the valve port is connected to the drive assembly through the clearance part.

[0023] In some embodiments, the regulating valve further includes a drive assembly for moving the valve core structure;

[0024] The valve core structure further includes a moving component, and the end of the valve core rod away from the valve port is throttle-connected to the moving component; the moving component is elastically connected to the drive assembly;

[0025] A portion of the moving part is used as the moving component.

[0026] In some embodiments, the regulating valve further includes a drive assembly and a controller, wherein the drive assembly is connected to the valve core structure and is used to drive the sealing surface to move relative to the valve port of the valve body assembly;

[0027] The controller is used to obtain the target position of the sealing surface corresponding to the set flow rate value when a set flow rate value is received; to receive the current position of the sealing surface detected by the position detection device in real time; and to control the drive assembly to drive the sealing surface to move relative to the valve port of the valve body assembly according to the current position of the sealing surface and the target position, until the sealing surface moves to the target position.

[0028] In some embodiments, the distance between the fixed member and the movable member varies by a range of greater than or equal to 20 micrometers and less than or equal to 90 micrometers.

[0029] As another technical solution, this application also provides a mass flow controller, including a main body and the aforementioned regulating valve provided in this application disposed on the main body.

[0030] As another technical solution, this application also provides a flow control method for a mass flow controller, comprising:

[0031] Upon receiving a set flow rate value, the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow rate value is obtained;

[0032] The current position of the sealing surface is received in real time, and based on the current position of the sealing surface and the target position, the valve port of the sealing surface relative to the valve body assembly of the regulating valve of the mass flow controller is controlled to move until it moves to the target position.

[0033] In some embodiments, obtaining the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow value upon receiving the set flow value includes:

[0034] Obtain the target parameter value of the variable element corresponding to the set flow rate value; the parameter value of the variable element is related to the distance from the sealing surface to the valve port;

[0035] The step of receiving the current position of the sealing surface in real time, and controlling the movement of the sealing surface relative to the valve body assembly of the regulating valve of the mass flow controller, based on the current position of the sealing surface and the target position, until it moves to the target position, includes:

[0036] The system receives the parameter detection values ​​of the variable element in real time, and controls the movement of the sealing surface relative to the valve port of the valve body assembly based on the parameter detection values ​​and the target parameter values, until the parameters of the variable element reach the target parameter values.

[0037] In some embodiments, obtaining the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow value upon receiving the set flow value includes:

[0038] Upon receiving the set flow rate value, the inlet pressure value of the mass flow controller under the current operating conditions is obtained;

[0039] Based on the pre-stored correspondence between the set flow rate value and the target position of the sealing surface under multiple different inlet pressure values, the target position of the sealing surface corresponding to the received set flow rate value under the current operating condition is obtained at the inlet pressure value.

[0040] In some embodiments, after controlling the sealing surface to move relative to the valve port of the valve body assembly until it reaches the target position, the flow control method further includes:

[0041] Determine whether the actual flow rate value output by the mass flow controller is within the error range corresponding to the set flow rate value;

[0042] If so, the process ends;

[0043] If not, compare the actual flow rate value with the set flow rate value, and adjust the target position of the sealing surface according to the comparison result. Then return to the step of receiving the current position of the sealing surface in real time, and controlling the sealing surface to move relative to the valve port of the valve body assembly according to the current position of the sealing surface and the target position until it moves to the target position. The target position in the returned step is the adjusted target position.

[0044] This application has the following beneficial effects:

[0045] The regulating valve provided in this application is equipped with a position detection device, which is used to detect the position of the sealing surface of the valve core structure relative to the valve port (equivalent to the opening degree of the regulating valve). In other words, the position detection device can directly detect the opening degree of the regulating valve for flow control. Compared with the prior art, which indirectly obtains the opening degree of the regulating valve based on the magnitude of the valve voltage, the flow control accuracy and repeatability are higher, which can meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0046] The mass flow controller provided in this application, by employing the aforementioned regulating valve, can improve the accuracy and repeatability of flow control, thereby meeting the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0047] The flow control method of the mass flow controller provided in this application controls the movement of the sealing surface relative to the valve port of the valve body assembly (i.e., controls the opening of the regulating valve) based on the target position of the sealing surface corresponding to the set flow value and the current position of the sealing surface detected in real time, until the sealing surface moves to the target position of the sealing surface, so as to achieve flow control. Compared with the corresponding technology that indirectly obtains the opening of the regulating valve based on the magnitude of the valve voltage, the flow control accuracy and repeatability are higher, which can meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability. Attached Figure Description

[0048] Figure 1 shows three sets of curves relating valve voltage and actual flow rate under three different inlet pressures in related technologies.

[0049] Figure 2 is a partial cross-sectional view of a regulating valve in one state according to an embodiment of this application;

[0050] Figure 3 is a schematic diagram of a position detection device according to an embodiment of this application;

[0051] Figure 4 shows three sets of curves relating valve voltage and actual flow rate under three different inlet pressures in the embodiments of this application.

[0052] Figure 5 is a partial cross-sectional view of the regulating valve in Figure 2 when a different position detection device is used;

[0053] Figure 6 is a schematic diagram of another position detection device shown in Figure 5;

[0054] Figure 7 is a partial cross-sectional view of the control valve in Figure 2 in another state;

[0055] Figure 8 is a partial perspective view of the regulating valve in Figure 2;

[0056] Figure 9 is a partial exploded view of the control valve in Figure 8;

[0057] Figure 10 is a perspective view of the valve core mounting component of the regulating valve in Figure 8 in one direction;

[0058] Figure 11 is a perspective view of the valve core mounting component of the regulating valve in Figure 8 from another direction;

[0059] Figure 12 is a cross-sectional view of the control valve in Figure 2 with a drive assembly;

[0060] Figure 13 is a cross-sectional view of the connecting sleeve in Figure 12;

[0061] Figure 14 is a cross-sectional view of the guide connecting sleeve in Figure 12;

[0062] Figure 15 is a partial enlarged view of the regulating valve at the position detection device in Figure 12;

[0063] Figure 16 is a partial cross-sectional view of another regulating valve provided in an embodiment of this application;

[0064] Figure 17 is a partial cross-sectional view of the control valve in Figure 16 with another drive component;

[0065] Figure 18 is a partial perspective view of the regulating valve in Figure 17 with another drive component;

[0066] Figure 19 is a schematic diagram of the mass flow controller provided in an embodiment of this application;

[0067] Figure 20 is a flowchart of the flow control method of the mass flow controller provided in an embodiment of this application;

[0068] Figure 21 is a flowchart of step S1 of the flow control method of the mass flow controller provided in the embodiment of this application. Detailed Implementation

[0069] To enable those skilled in the art to better understand the technical solutions of this application, the regulating valve, mass flow controller and flow control method provided in this application will be described in detail below with reference to the accompanying drawings.

[0070] The pressure-type mass flow controllers in related technologies cannot directly obtain the valve opening. Taking a piezoelectric valve as an example, the related technologies indirectly obtain the valve opening based on the valve voltage. Figure 1 shows three sets of curves related to valve voltage and actual flow rate under three different inlet pressures in the related technologies. Each set of curves includes curves related to valve voltage and actual flow rate during the process of changing from 0% to 100% of the full scale of the set flow rate value, and curves related to valve voltage and actual flow rate during the process of changing from 100% to 0% of the full scale of the set flow rate value. The part of the curve corresponding to the change from 100% to 0% is below the part corresponding to the change from 0% to 100%. From these three sets of curves, it can be seen that the actual flow rate corresponding to the same valve voltage on the two curves in each set of curves is very different. Therefore, it can be seen that the related technologies have poor accuracy and repeatability in flow control and cannot meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0071] To address the aforementioned problems, this application provides a regulating valve comprising a valve body assembly, a valve core assembly, and a position detection device. The valve body assembly has a valve port; the valve core assembly includes a valve core structure with a sealing surface, the valve core structure being configured to allow the sealing surface to move relative to the valve body assembly in a direction approaching or away from the valve port to open or close the valve port, and to regulate the flow rate of fluid passing through the valve port; the position detection device is used to detect the position of the sealing surface relative to the valve port.

[0072] The regulating valve provided in this application embodiment is equipped with a position detection device. This position detection device is used to detect the position of the sealing surface of the valve core assembly relative to the valve port (equivalent to the opening degree of the regulating valve). In other words, the position detection device can directly detect the opening degree of the regulating valve for flow control. Compared with the prior art, which indirectly obtains the opening degree of the regulating valve based on the magnitude of the valve voltage, the accuracy and repeatability of flow control are higher, which can meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0073] In some embodiments, the regulating valve further includes a drive assembly and a controller. The drive assembly is connected to the valve core structure and is used to drive the sealing surface to move relative to the valve port of the valve body assembly. The controller is used to obtain the target position of the sealing surface corresponding to the set flow rate value when a set flow rate value is received. It receives the current position of the sealing surface detected by the position detection device in real time, and controls the drive assembly to drive the sealing surface to move relative to the valve port of the valve body assembly according to the current position and the target position of the sealing surface until it moves to the target position. Automatic flow control can be achieved by means of the drive assembly and the controller. Based on this, the embodiments of this application control the sealing surface to move relative to the valve port of the valve body assembly (i.e., control the opening of the regulating valve) according to the target position of the sealing surface corresponding to the set flow rate value and the current position of the sealing surface detected in real time, until it moves to the target position of the sealing surface, so as to achieve flow control. Compared with the related technology that indirectly obtains the opening of the regulating valve based on the magnitude of the valve voltage, the accuracy and repeatability of flow control are higher, which can meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0074] The position detection device for directly detecting the opening of a regulating valve can have various structures. For example, in some embodiments, the position detection device includes a moving component and a parameter detection unit. The moving component is connected to the valve core structure and is equipped with a variable element whose parameter changes with the movement of the sealing surface. The parameter detection unit is used to detect the parameter of the variable element. Specifically, the moving component can move synchronously with the sealing surface, and during this process, the parameter of the variable element configured in the moving component changes with the movement of the sealing surface. That is, the parameter of the variable element is related to the opening of the regulating valve. Therefore, the opening of the regulating valve can be characterized by detecting the parameter of the variable element through the parameter detection unit for flow control. Specifically, the parameter measurement value of the variable element detected in real time by the parameter detection unit is used as a feedback signal to control the distance between the sealing surface and the valve port (equivalent to the opening of the regulating valve) until the parameter measurement value of the variable element corresponding to this distance reaches the parameter target value corresponding to the set flow rate value.

[0075] In some embodiments, the variable element includes a capacitor or a resistor. The parameter of the variable element is the capacitance or resistance value. During the synchronous movement of the moving component with the sealing surface, the magnitude of the capacitance or resistance can change with the movement of the sealing surface, thereby relating the magnitude of the capacitance or resistance to the opening degree of the regulating valve.

[0076] In other embodiments, the position detection device may include a position sensor connected to the valve core structure to move synchronously with the sealing surface and detect its own position relative to the valve port in the process. Specifically, the position sensor can move synchronously with the sealing surface, and in this process, the position of the position sensor relative to the valve port changes with the movement of the sealing surface. That is, the position of the position sensor relative to the valve port is associated with the opening degree of the regulating valve. Thus, the opening degree of the regulating valve can be characterized by the position of the position sensor relative to the valve port for flow control. That is, the position of the position sensor relative to the valve port detected in real time is used as a feedback signal to control the distance between the sealing surface and the valve port (equivalent to the valve opening degree) until the position of the position sensor relative to the valve port corresponding to this distance reaches the target position corresponding to the set flow value.

[0077] In an embodiment where the position detection device includes a moving component and a parameter detection unit, the moving component includes a fixed member and a moving member, wherein the fixed member and the moving member constitute the aforementioned variable element; the fixed member is connected to the valve body assembly; and the moving member is connected to the valve core structure. Since the moving member can move synchronously with the sealing surface, while the fixed member connected to the valve body assembly remains stationary, the distance between the fixed member and the moving member changes with the distance between the sealing surface and the valve port (equivalent to the valve opening degree).

[0078] Based on this, in some embodiments, the variable element composed of the fixed and moving parts is a capacitor. The size of this capacitor is related to the opening degree of the regulating valve, so that the opening degree of the regulating valve can be characterized by detecting the size of the capacitor through a parameter detection unit for flow control. The structure of the capacitor composed of the fixed and moving parts is more suitable for smaller spaces and does not require much modification to the regulating valve. This advantage makes the structure of the variable element composed of the fixed and moving parts as a capacitor more suitable for small devices such as mass flow controllers. Moreover, the structure of the capacitor is simpler and easier to implement than other variable elements, thereby reducing costs.

[0079] In other embodiments, the variable element consisting of a fixed member and a moving member includes a resistor. In this case, the fixed member is provided with a resistive element, and the moving member is provided with a contact element, which is in electrical contact with the resistive element. As the moving member moves relative to the fixed member, the contact position between the contact element and the resistive element changes with the distance between the sealing surface and the valve port (equivalent to the valve opening). This causes the portion of the resistive element connected in the circuit to change, i.e., the resistance changes. The resistance is related to the valve opening, so the valve opening can be characterized by detecting the resistance through a parameter detection unit for flow control.

[0080] The following describes in detail the specific implementation of the regulating valve provided in the embodiments of this application, taking a variable element consisting of a fixed part and a moving part, including a capacitor, as an example.

[0081] Referring to Figure 2, the regulating valve 1 provided in this embodiment includes a valve body assembly 11, a valve core assembly 12, and a position detection device 13. The valve body assembly 11 has a valve port 113. Specifically, the valve body assembly 11 is provided with an inlet channel 114a and an outlet channel 114b. The valve port 113 is formed between the inlet channel 114a and the outlet channel 114b. When the valve port 113 is closed, the inlet channel 114a and the outlet channel 114b are disconnected; when the valve port 113 is opened, the inlet channel 114a and the outlet channel 114b are connected.

[0082] In some embodiments, the valve body assembly 11 includes a valve body 111 and a valve seat 112, wherein the valve body 111 is provided with a mounting groove for mounting the valve seat 112, the valve seat 112 is disposed in the mounting groove, and the valve seat 112 has a first surface 112a opposite to the valve core assembly 12. The aforementioned inlet channel 114a and outlet channel 114b are disposed in the valve body 111, and the valve seat 112 is provided with a valve seat inlet channel 112b and a valve seat outlet channel 112c. The valve seat inlet channel 112b has an outlet formed on the first surface 112a of the valve seat 112, which serves as the valve port 113. The valve seat outlet channel 112c has an inlet formed on the first surface 112a. The valve seat outlet channel 112c includes, for example, a plurality of through holes surrounding the valve seat inlet channel 112b and two annular grooves connecting the plurality of through holes. The two annular grooves are respectively formed on the first surface 112a and the surface opposite to the first surface 112a of the valve seat 112. Each through hole penetrates the valve seat 112, and the two ends of each through hole are respectively located on the bottom surface of the two annular grooves. The annular groove formed on the first surface 112a of the valve seat 112 serves as the inlet of the valve seat outlet channel 112c surrounding the valve port 113. One end of the inlet channel 114a in the valve body 111 is located at the bottom surface of the mounting groove and communicates with the valve seat inlet channel 112b, while the other end is used to allow fluid to flow into the valve body 111; one end of the outlet channel 114b is located at the bottom surface of the mounting groove and communicates with the valve seat outlet channel 112c, while the other end is used to allow fluid to flow out of the valve body 111.

[0083] The valve core assembly 12 includes a valve core structure 122, which has a sealing surface. The valve core structure 122 is configured to move relative to the valve body assembly 11 in a direction close to or far from the valve port 113 (i.e., parallel to the X-axis in FIG. 2) to open or close the valve port 113 and regulate the flow rate of fluid through the valve port 113. Specifically, the closer the sealing surface of the valve core structure 122 is to the valve port 113, the smaller the flow rate of fluid through the valve port 113; conversely, the farther the sealing surface of the valve core structure 122 is from the valve port 113, the larger the flow rate of fluid through the valve port 113. The position of the sealing surface of the valve core structure 122 from the valve port 113 is the valve opening degree.

[0084] Please refer to Figures 2 and 3 together. The position detection device 13 includes a moving component and a parameter detection unit 133. The moving component includes a fixed member 131 and a moving member 132. Both the fixed member 131 and the moving member 132 are electrode plates, which are arranged opposite each other along the moving direction of the sealing surface of the valve core structure 122 (i.e., parallel to the X-axis in Figures 2 and 3) to form a capacitor. The fixed member 131 is connected to the valve body assembly 11; the moving member 132 is connected to the valve core structure 122; and the parameter detection unit 133 is used to detect the magnitude of the capacitor. Specifically, the parameter detection unit 133 includes, for example, a capacitor detection circuit electrically connected to the fixed member 131 and the moving member 132. The capacitance C (in F) formed by the fixed member 131 and the moving member 132 satisfies the following relationship:

[0085] Where ε₀ is the vacuum permittivity, which is equal to 8.854 × 10⁻¹²; ε r d is the dielectric constant between the fixed member 131 and the movable member 132, and the medium between the fixed member 131 and the movable member 132 is, for example, air, water, oil, etc.; d is the distance between the fixed member 131 and the movable member 132; S is the relative area of ​​the fixed member 131 and the movable member 132.

[0086] As can be seen from the above formula, the capacitance C is linearly related to the distance d. Based on this, since the moving part 132 can move synchronously with the sealing surface of the valve core structure 122, while the fixed part 131 connected to the valve body assembly 11 remains stationary, the distance d between the fixed part 131 and the moving part 132 changes with the distance between the sealing surface of the valve core structure 122 and the valve port 113 (equivalent to the valve opening). That is, the capacitance C formed by the fixed part 131 and the moving part 132 is related to the valve opening. Therefore, the valve opening can be characterized by detecting the capacitance C through the parameter detection unit 133 for flow control. Specifically, the measured value of capacitance C detected in real time by the parameter detection unit 133 is used as a feedback signal to control the distance between the sealing surface of the valve core structure 122 and the valve port 113 (equivalent to the valve opening) until the measured value of capacitance C corresponding to this distance reaches the target value corresponding to the set flow rate.

[0087] In related technologies, pressure-type mass flow controllers cannot directly obtain the valve opening. Taking a piezoelectric valve as an example, the related technologies indirectly obtain the valve opening based on the valve voltage. Figure 1 shows three sets of curves related to valve voltage and actual flow rate under three different inlet pressures in the related technologies. Each set of curves includes curves related to valve voltage and actual flow rate during the process of changing from 0% to 100% of the full scale of the set flow rate value, and curves related to valve voltage and actual flow rate during the process of changing from 100% to 0% of the full scale of the set flow rate value. The part of the curve corresponding to the change from 100% to 0% is below the part of the curve corresponding to the change from 0% to 100%. From these three sets of curves, it can be seen that the actual flow rate corresponding to the same valve voltage of the two curves in each set of curves is very different. Therefore, it can be seen that the related technologies have poor accuracy and repeatability in flow control and cannot meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability. Compared to related technologies, Figure 4 shows three sets of curves related to capacitance and actual flow rate under three different inlet pressures in the embodiments of this application. Each set of curves includes curves related to capacitance and actual flow rate during the process of changing from 0% to 100% of the full scale of the set flow rate value, and curves related to capacitance and actual flow rate during the process of changing from 100% to 0% of the full scale of the set flow rate value. The portion of the curve corresponding to the change from 100% to 0% is below the portion of the curve corresponding to the change from 0% to 100%. Comparing with Figure 1, it can be seen that the regulating valve 1 provided in the embodiments of this application controls the flow rate by detecting the size of the capacitance. The actual flow rates corresponding to the same capacitance in the two curves in each set are very close. Therefore, it can be seen that the regulating valve 1 provided in the embodiments of this application has higher accuracy and repeatability in flow control compared to related technologies, which can meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0088] In some embodiments, as shown in Figures 2 and 3, there is one fixing member 131, which, together with the moving member 132, forms a capacitor C. However, the accuracy of detecting a single capacitor C may be affected by ambient temperature and humidity. To address this issue, in other embodiments, as shown in Figures 5 and 6, there are two fixing members 131, both of which are electrode plates and are arranged opposite each other along the moving direction of the sealing surface of the valve core structure 122 (i.e., parallel to the X-axis in Figures 5 and 6), and both are connected to the valve body assembly 11. The moving member 132 is an electrode plate and is located between the two fixing members 131. The two fixing members 131 and the moving member 132 respectively form a first capacitor C1 and a second capacitor C2. A parameter detection unit 133 is used to detect the magnitude of the first capacitor C1 and the second capacitor C2. Specifically, the parameter detection unit 133 includes, for example, a capacitance detection circuit electrically connected to the two fixing members 131 and the moving member 132. The first capacitor C1 and the second capacitor C2 (in F) formed by the moving part 132 and the two fixed parts 131 respectively satisfy the following relationship:

[0089] or,

[0090] As shown in Figure 6, d1 is the distance between the first fixing member 131a and the moving member 132; d2 is the distance between the second fixing member 131b and the moving member 132; S1 is the relative area between the first fixing member 131a and the moving member 132; and S2 is the relative area between the second fixing member 131b and the moving member 132.

[0091] From the above relationship, it can be seen that since the measurement environment of the first capacitor C1 and the second capacitor C2 is the same, the vacuum permittivity ε0 and the permittivity ε r Therefore, the vacuum permittivity ε0 and the permittivity ε can be eliminated by detecting the values ​​of the first capacitor C1 and the second capacitor C2 and calculating their ratio or the ratio of their difference to their sum. r By using the above ratio as a feedback signal for flow control, the detection accuracy can be guaranteed to be unaffected by ambient temperature and humidity, thereby further improving control accuracy.

[0092] It should be noted that, regardless of whether there is one or two fasteners 131, the valve body assembly 11 and valve core assembly 12 can be of the same structure, and one or two fasteners 131 are connected to the valve body assembly 11.

[0093] In some embodiments, as shown in FIG2, the valve core assembly 12 further includes a valve core mounting member 121, which is fixedly connected to the valve body assembly 11 (e.g., valve body 111) and located on the side of the valve body assembly 11 where the valve port 113 is located. That is, the valve core mounting member 121 is opposite to the sealing surface of the valve body assembly 11 used for sealing contact with the sealing surface of the valve core structure 122 to close the valve port 113. The valve core mounting member 121 is used to provide a mounting base for the valve core structure 122, enabling the valve core structure 122 to be mounted on the valve body assembly 11. The valve core structure 122 includes a valve core rod 122a, which is movably connected to the valve core mounting member 121 and extends along the moving direction of the sealing surface of the valve core structure 122 (i.e., parallel to the X-axis in Figures 2 and 7). The valve core rod 122a has a sealing surface near the valve port 113, which can seal against the valve body assembly 11 to close the valve port 113. The valve core rod 122a can move relative to the valve core mounting member 121 in a direction close to or away from the valve port 113 (i.e., parallel to the X-axis in Figures 5 and 6) to regulate the flow rate of fluid through the valve port 113 by moving the sealing surface of the valve core structure 122. The position of the sealing surface of the valve core structure 122 from the valve port 113 is the valve opening degree.

[0094] Based on this, in an embodiment where the valve body assembly 11 includes a valve body 111 and a valve seat 112, the valve core mounting member 121 is located on the side of the valve body 111 adjacent to the first surface 112a and is fixedly connected to the valve body 111. The sealing surface of the valve core structure 122 is used to make sealing contact with the gap area between the outlet (i.e., valve port 113) of the valve seat inlet channel 112b and the inlet of the valve seat outlet channel 112c, so as to isolate the outlet (i.e., valve port 113) from the inlet, thereby achieving the sealing of the valve port 113.

[0095] Furthermore, the fixing member 131 is fixedly disposed relative to the valve core mounting member 121. For example, the fixing member 131 is fixedly connected to the valve core mounting member 121; the moving member 132 is fixedly connected to the valve core structure 122. The valve core mounting member 121 is also used to provide a mounting base for the fixing member 131 (which can be one or two). Since the valve core mounting member 121 is fixedly connected to the valve body assembly 11 (e.g., valve body 111), the fixing member 131 fixedly connected to the valve core mounting member 121 can remain stationary, thereby allowing the distance d between the fixing member 131 and the moving member 132 to change with the distance between the sealing surface of the valve core structure 122 and the valve port 113 (equivalent to the valve opening degree).

[0096] In some embodiments, to enable the sealing surface of the valve core structure 122 to move relative to the valve core mounting member 121 to a position where the sealing surface seals the valve port 113 or moves away from that position, the valve core mounting member 121 and the valve core structure 122 can have various structures. For example, as shown in Figures 2 and 7, the valve core mounting member 121 is provided with a through space 122c that extends through the valve core mounting member 121 along the moving direction of the sealing surface of the valve core structure 122 (i.e., parallel to the X-axis in Figures 2 and 7). The valve core structure 122 also includes an elastic member 122b that is sealed between the outer peripheral surface of the valve core rod 122a and the inner wall of the through space 122c. The fixing member 131 is located on the side of the valve core mounting member 121 facing away from the valve body assembly 11, and a receiving space 134 is formed between the fixing member 131 and the valve core mounting member 121; the moving member 132 is fixedly connected to the valve core rod 122a and is at least partially located in the receiving space 134.

[0097] Specifically, the valve core rod 122a extends along the moving direction of the sealing surface of the valve core structure 122 (i.e., parallel to the X-axis in Figures 2 and 7) and is movably inserted through the through space 122c of the valve core mounting member 121. The sealing surface is provided at the end of the valve core rod 122a near the valve port 113, and the end of the valve core rod 122a away from the valve port 113 is connected to a drive assembly (described in detail below) for driving its movement. When the drive assembly applies a driving force, the valve core rod 122a can move away from the position where the sealing surface seals the valve port 113, for example, from the position shown in Figure 2 to the position shown in Figure 7; when the drive assembly does not apply a driving force, the valve core rod 122a can be reset to the position where the sealing surface seals the valve port 113 under the action of the elastic member 122b. Furthermore, when no driving force is applied to the drive assembly, the valve core rod 122a is in its initial position (i.e., the position shown in FIG. 2). In this initial position, the elastic force applied by the elastic member 122b to the valve core rod 122a can hold the sealing surface in the position of sealing the valve port 113. When the drive assembly applies a driving force, this driving force can overcome the aforementioned elastic force and drive the valve core rod 122a to move, so that the sealing surface moves away from the valve port 113. Based on this, by sealing the aforementioned sealing member between the outer peripheral surface of the valve core rod 122a and the inner wall of the through space 122c, the gap between the valve core rod 122a and the inner wall of the through space 122c can be sealed, thereby sealing the fluid on the side of the sealing member near the valve port 113. This sealing member is, for example, an annular elastic diaphragm, whose inner and outer peripheral ends are respectively sealed to the outer peripheral surface of the valve core rod 122a and the inner wall of the through space 122c. The sealing connection can be, for example, welded or integrally connected. Because the annular elastic diaphragm is elastic, the valve core rod 122a is elastically connected to the valve core mounting part 121 through the annular elastic diaphragm, so as to realize the movable connection between the valve core rod 122a and the valve core mounting part 121.

[0098] Based on this, the fixing member 131 is located on the side of the valve core mounting member 121 opposite to the valve body assembly 11 (e.g., valve body 111), and a receiving space 134 is formed between the fixing member 131 and the valve core mounting member 121; the moving member 132 is fixedly connected to the valve core rod 122a and is at least partially located in the receiving space 134. In this way, the moving member 132 can move synchronously with the valve core rod 122a in the receiving space 134, and since the fixing member 131 is fixedly connected to the valve core mounting member 121, the distance between the fixing member 131 and the moving member 132 will change with the distance between the sealing surface on the valve core rod 122a and the valve port 113 (equivalent to the valve opening degree). When the drive assembly does not apply a driving force, as shown in FIG2, the valve core rod 122a is in the initial position, in which the initial distance between the fixing member 131 and the moving member 132 is the largest. When the driving component applies a driving force, the sealing surface moves away from the valve port 113. During this process, the distance between the fixed member 131 and the moving member 132 gradually decreases. If the initial distance between the fixed member 131 and the moving member 132 is d0 (as shown in Figure 2), and the distance after movement is d1 (as shown in Figure 7), then the distance L1 between the sealing surface and the valve port 113 (as shown in Figure 7) is equal to d0 - d1. It is easy to understand that the initial distance d0 between the fixed member 131 and the moving member 132 should be greater than the maximum stroke of the sealing surface. In some embodiments, in order to ensure that the measured capacitance change has a sufficiently high resolution, the initial distance d0 between the fixed member 131 and the moving member 132 should not be too large. The range of distance variation between the fixed member 131 and the moving member 132 is, for example, from 20 micrometers to 90 micrometers.

[0099] In some embodiments, the regulating valve 1 further includes a drive assembly for moving the valve core rod 122a. Furthermore, as shown in Figures 2 and 7, a clearance portion 131c is provided on the fixing member 131 at the position corresponding to the valve core rod 122a, and the end of the valve core rod 122a away from the valve port 113 is connected to the drive assembly via the clearance portion 131c. The clearance portion 131c prevents the fixing member 131 from interfering with the movement of the valve core rod 122a. The clearance portion 131c can be a through hole provided in the fixing member 131, or the fixing member 131 can be a shaped plate, which itself constitutes a clearance portion 131c capable of offsetting the movement path of the valve core rod 122a.

[0100] In one specific embodiment, referring to Figures 8 to 11, the valve core mounting component 121 includes a fixing body 1211, which is fixedly connected to the valve body assembly 11 by six first screws 123. However, this embodiment is not limited to this; in practical applications, the fixing body 1211 can also be fixedly connected to the valve body assembly 11 by welding, bonding, riveting, or other methods. The fixing body 1211 has a through space 122c extending through it along the moving direction of the valve core rod 122a. The valve core rod 122a is movably inserted through the through space 122c, and a sealing surface 122a1 is located at the end of the valve core rod 122a near the valve port 113. The elastic element 122b is an annular elastic diaphragm, which is sealed between the outer peripheral surface of the valve core rod 122a and the inner wall of the through space 122c. The fixing member 131 is located on the side of the valve core mounting member 121 away from the valve body assembly 11, and an accommodating space is formed between the fixing member 131 and the valve core mounting member 121; the moving member 132 is fixedly connected to the valve core rod 122a, and is at least partially located in the accommodating space.

[0101] Multiple bosses 1212 are provided on the surface of the fixing body 1211 facing away from the valve body assembly 11. These bosses 1212 are spaced apart and collectively support the fixing member 131, maintaining a certain distance between the fixing member 131 and the surface of the fixing body 1211 facing away from the valve body assembly 11. This distance serves as the aforementioned accommodating space. The fixing member 131 is fixedly connected to the multiple bosses 1212 one-to-one by multiple second screws 135. However, this embodiment is not limited to this; in practical applications, the fixing member 131 can also be fixedly connected to the bosses 1212 by welding, bonding, riveting, or other methods. Based on this, the moving member 132 is located in the aforementioned accommodating space and is fixedly connected to the valve core rod 122a. The fixing member 131 also has a through hole, which serves as a clearance portion 131c, allowing the end of the valve core rod 122a away from the valve port 113 to pass through, enabling transmission connection with the drive assembly.

[0102] In some embodiments, the position detection device 13 also includes a circuit board with an integrated parameter detection unit 133 and cables for transmitting signals and power supply. The circuit board can be integrated with the fixing member 131. Furthermore, a recess 1213 for leading out cables can be provided on the surface of the fixing member body 1211 on the side opposite to the valve body assembly 11, as shown in FIG10.

[0103] The drive assembly that applies driving force to the valve core rod 122a can employ various driving methods, such as piezoelectric drive, electromagnetic drive, etc. In other words, the regulating valve 1 provided in this embodiment can be a piezoelectric valve, a solenoid valve, etc. Taking the regulating valve 1 as a piezoelectric valve as an example, please refer to Figures 12 to 15. The aforementioned drive assembly 2 may include a connecting sleeve 21, a piezoelectric ceramic component 22, a top encapsulation component 23, a support block 24, a fixing seat 25, and an elastic component 26. As shown in Figure 13, the connecting sleeve 21 is provided with a first through hole 211 and a second through hole 212 that penetrate the sidewall, and the first through hole 211 and the second through hole 212 are arranged opposite to each other. The support block 24 passes through the first through hole 211 and the second through hole 212, dividing the inner cavity of the connecting sleeve 21 into an upper cavity and a lower cavity. In the axial direction of the connecting sleeve 21, the support block 24 slides with the first through hole 211 and the second through hole 212, and the support block 24 is fixedly connected to the fixing seat 25. There are multiple ways to fix the support block 24 to the fixed seat 25. For example, the two ends of the support block 24 extending outside the first through hole 211 and the second through hole 212 are respectively connected to the fixed seat 25 by screw threads.

[0104] The top encapsulation component 23 is installed on the top of the connecting sleeve 21 to fix the piezoelectric ceramic component 22. The piezoelectric ceramic component 22 can have various structures, such as a rod-shaped piezoelectric ceramic component. The piezoelectric ceramic component 22 is installed in the upper cavity of the connecting sleeve 21. The bottom end of the piezoelectric ceramic component 22 abuts against the support block 24 through a first self-aligning ball 29. The first self-aligning ball 29 mates with the concave conical pits provided on the bottom of the piezoelectric ceramic component 22 and the top of the support block 24. The top end of the piezoelectric ceramic component 22 mates with the top encapsulation component 23. The bottom of the connecting sleeve 21 abuts against the top end of the valve core rod 122a through a second self-aligning ball 27. The second self-aligning ball 27 mates with the concave conical pits provided on the top of the valve core rod 122a and the bottom surface of the connecting sleeve 21. The elastic component 26 is installed in the lower cavity of the connecting sleeve 21, and the two ends of the elastic component 26 press against the bottom of the lower cavity of the connecting sleeve 21 and the support block 24, respectively.

[0105] The drive assembly 2 also includes a guide connecting sleeve 28, as shown in Figure 14. The guide connecting sleeve 28 is provided with a third through hole 281 and a fourth through hole 282 that penetrate the sidewall respectively, and the third through hole 281 and the fourth through hole 282 are arranged opposite to each other. The guide connecting sleeve 28 is fixedly connected to the fixed seat 25, and various fixing connection methods can be used, such as threaded connection, interference fit connection, etc. The guide connecting sleeve 28 is sleeved on the outside of the connecting sleeve 21, and the outer wall of the connecting sleeve 21 is in contact with the inner wall of the guide connecting sleeve 28 to ensure that the connecting sleeve 21 moves stably in the axial direction relative to the guide connecting sleeve 28. The support block 24 passes through the first through hole 211, the third through hole 281, the second through hole 212, and the fourth through hole 282. The first through hole 211, the third through hole 281, the second through hole 212 and the fourth through hole 282 can have various shapes. In order to ensure that the connecting sleeve 21 has sufficient movement relative to the support block 24, they can all be set as long strip-shaped through holes extending along the axial direction of the connecting sleeve 21, such as rectangular through holes.

[0106] A top block 261 is also provided in the lower cavity of the connecting sleeve 21. The top block 261 is positioned between the elastic member 26 and the support block 24. The two ends of the elastic member 26 press against the top block 261 and the bottom of the lower cavity of the connecting sleeve 21, respectively. The elastic member 26 can be of various types, such as a spring. During operation, the elastic member 26 is in a compressed state.

[0107] The top encapsulation component 23 can have various structures. For example, the top encapsulation component 23 includes a piezoelectric ceramic fixing nut 231 for fixing the piezoelectric ceramic component 22, and the piezoelectric ceramic fixing nut 231 is threadedly connected to the side wall of the top of the connecting sleeve 21. The top encapsulation component 23 may also include a locking nut 232; the piezoelectric ceramic fixing nut 231 is located above the locking nut 232, and the locking nut 232 is threadedly connected to the side wall of the top of the connecting sleeve 21. The upper end of the piezoelectric ceramic component 22 is fixed by the piezoelectric ceramic fixing nut 231, and the lower end of the piezoelectric ceramic component 22 is abutted against the support block 24 by the first self-aligning ball 29.

[0108] When the drive assembly 2 is not energized, i.e., when the piezoelectric ceramic component 22 is not energized, the connecting sleeve 21 is in a fixed position under the action of the elastic component 26. At this time, the upper end of the connecting sleeve 21 abuts against the top of the piezoelectric ceramic component 22 through the piezoelectric ceramic fixing nut 231, and the bottom of the piezoelectric ceramic component 22 abuts against the support block 24. When the drive assembly 2 receives a voltage signal, the piezoelectric ceramic component 22 generates a corresponding elongation ΔX according to the applied valve voltage. One end of the piezoelectric ceramic component 22 abuts against the support block 24 through the first self-aligning ball 29, i.e., the position of this end is relatively fixed. After the piezoelectric ceramic component 22 elongates, the other end drives the piezoelectric ceramic fixing nut 231 and the connecting sleeve 21 to move upward by a displacement of ΔX. At this time, the elastic component 26 compresses ΔX, and the bottom surface of the connecting sleeve 21 moves upward by a displacement of ΔX. The bottom surface of the connecting sleeve 21 abuts against the valve core rod 122a through the second self-aligning ball 27, driving the valve core rod 122a to move upward by a displacement of ΔX.

[0109] In the above embodiments, the moving member 132 is a separate component relative to the valve core structure 122. However, in other embodiments, as shown in FIG16, in order to simplify the structure of the regulating valve 1' and reduce the number of components, the moving member 132' may also be at least a part of a corresponding component in the valve core structure. For example, the valve core structure 122 includes a valve core rod 122a and a moving member 136, wherein the valve core rod 122a extends along the moving direction of the sealing surface of the valve core structure 122 (i.e., parallel to the X-axis in FIG16), and the sealing surface is disposed at the end of the valve core rod 122a near the valve port 113; the end of the valve core rod 122a away from the valve port 113 is drivenly connected to the moving member 136; the moving member 136 is elastically connected to the drive assembly (described in detail below); and a portion of the moving member 136 serves as the moving member 132'. When the drive assembly applies a driving force, it can drive the moving part 136 to move the valve core rod 122a away from the position where the sealing surface seals the valve port 113. When the drive assembly does not apply a driving force, due to the elastic connection between the moving part 136 and the drive assembly, the moving part 136 returns to its original position and drives the valve core rod 122a back to the position where the sealing surface seals the valve port 113. The elastic connection between the moving part 136 and the drive assembly is a thin-walled connecting post or connecting piece (described in detail below), which is connected between the moving part 136 and the drive assembly. It is used to generate elastic deformation when the drive assembly applies a driving force to move the moving part 136. When the drive assembly does not apply a driving force, the thin-walled connecting post or connecting piece returns to its initial shape to move the moving part 136 back to its original position.

[0110] Based on this, the fixed member 131' and the valve core mounting member 121 are fixedly arranged relative to each other, and the specific arrangement will be described in detail later. The movable member 132' is part of the movable component 136. Thus, the movement of the movable component 136 is the movement of the movable member 132'. Since the fixed member 131' and the valve core mounting member 121 are fixedly arranged relative to each other, the distance between the fixed member 131' and the movable member 132' changes with the distance between the sealing surface on the valve core rod 122a and the valve port 113 (equivalent to the valve opening). When the drive assembly does not apply a driving force, the valve core rod 122a is in the initial position, at which the initial distance between the fixed member 131 and the movable member 132 is the largest. When the drive assembly applies a driving force, the sealing surface moves away from the valve port 113, and during this process, the distance between the fixed member 131' and the movable member 132' gradually decreases.

[0111] In a specific embodiment, taking the regulating valve 1' as a piezoelectric valve as an example, please refer to Figures 17 and 18 together. The aforementioned driving assembly 2' may include a frame 20 and a piezoelectric ceramic component 22'. The frame 20 is fixedly connected to the valve body assembly 11 (e.g., valve body 111), and the fixing member 131' is fixedly connected to the frame 20. Furthermore, the frame 20 is provided with a hollow space 201 for accommodating the piezoelectric ceramic component 22'. The hollow space 201 has an opening on the side near the valve body assembly 11. One end of the piezoelectric ceramic component 22' abuts against the top of the hollow space 201, and the other end is elastically connected to the moving component 136 via the opening through a thin-walled connecting post or connecting piece 137. The fixing member 131' is disposed in the hollow space 201, and the surface of the fixing member 131' near the valve body assembly 11 is opposite to a portion of the surface of the moving component 136 away from the valve body assembly 11, thereby forming a capacitor. The piezoelectric ceramic component 22' is, for example, columnar and extends at an angle. When a voltage or current is applied, it deforms. The end of the piezoelectric ceramic component 22' furthest from the valve body assembly 11 is fixed by the frame 20, while the end closest to the valve body assembly 11 extends along its angled extension direction, thereby applying an angled pressure to the thin-walled connecting column or connecting piece 137 with very low stiffness. This causes the thin-walled connecting column or connecting piece 137 to elastically deform, driving the moving component 136 to move within a range, for example, 0.02mm-0.05mm. Since a portion of the moving component 136 serves as a capacitor formed by the moving member 132' and the fixed member 131', the movement of the moving component 136 is equivalent to the movement of the moving member 132'.

[0112] As another technical solution, please refer to Figure 19. This application embodiment also provides a mass flow controller 300, including a main body and the regulating valves provided in various embodiments of this application disposed on the main body.

[0113] In some embodiments, the valve body 111 of the regulating valve 311 is, for example, the downstream portion of the main body described above. The upstream portion of the main body is provided with a fluid passage 309 for transmitting fluid (e.g., gas, liquid). The inlet of the fluid passage 309 is provided with an inlet connector 303, the outlet of the fluid passage 309 communicates with the inlet channel 114a in the valve body 111, the outlet of the outlet channel 114b in the valve body 111 is provided with an outlet connector 307, and a flow divider 310 is provided in the fluid passage 309; a flow sensor 302 is provided between the inlet and outlet of the fluid passage 309 and is located upstream of the regulating valve 311 for detecting fluid flow rate.

[0114] In some embodiments, the mass flow controller 300 further includes an inlet pressure measurement module 305, an outlet pressure measurement module 304, and a control module 308. The inlet pressure measurement module 305 is located at the inlet of the fluid passage 309 and is used to detect the inlet pressure value of the fluid passage 309. The inlet pressure measurement module 305 can be connected to the inlet connector 303 via a tee connector. The outlet pressure measurement module 304 is located at the outlet of the outflow channel 114b and is used to detect the outlet pressure value of the outflow channel 114b. It can be connected to the outlet connector 307 via a tee connector.

[0115] The mass flow controller 300 provided in this embodiment operates as follows: Fluid enters the inlet connector 303 through the inlet pressure measurement module 305. During this process, the inlet pressure measurement module 305 feeds back the collected inlet pressure signal to the control module 308. The fluid entering the fluid passage 309 through the inlet connector 303 is divided into two paths. One path, containing most of the flow, passes through the splitter 310, while the other path, containing a smaller portion of the flow, passes through the flow sensor 302. The flow signal collected by the flow sensor 302 is fed back to the control module 308. This flow sensor 302 is, for example, a thermal flow meter. The fluid in the fluid passage 309 flows into the regulating valve 311 through the inlet channel 114a. After the flow is regulated by the regulating valve 311, the fluid flows into the outlet pressure measurement module 304 through the outlet channel 114b and the outlet connector 307. The outlet pressure measurement module 304 feeds back the collected outlet pressure signal to the control module 308.

[0116] The control module 308 processes the received inlet pressure signal, flow signal, and the current position of the sealing surface of the valve core structure (e.g., the detected value of capacitance or resistance) fed back by the position detection device in the regulating valve 311, and controls the valve core structure to move relative to the valve port of the valve body assembly according to the processing result until it moves to the target position (e.g., to make the capacitance or resistance reach its target value), thereby realizing flow control.

[0117] The mass flow controller 300 provided in this application embodiment, by employing the regulating valve 311 provided in various embodiments of this application, can perform flow control by directly detecting the position of the valve core structure relative to the valve port (equivalent to regulating the valve opening). Compared with the prior art, this can improve the accuracy and repeatability of flow control, thereby meeting the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0118] It should be noted that the mass flow controller 300 is not limited to the structure described in the above embodiment. For example, the outlet pressure measurement module 304 can be omitted. Alternatively, other types of mass flow controllers besides pressure-type mass flow controllers can be used.

[0119] In some embodiments, the regulating valve 311 described above is, for example, an automatically controllable valve such as a solenoid valve or a piezoelectric valve.

[0120] In some embodiments, the control module 308 includes a microcontroller unit (MCU), a memory, an A / D converter, and a drive circuit, etc.

[0121] In some embodiments, the method for obtaining the target position (e.g., the target value of capacitance or resistance) of the sealing surface of the valve core structure is as follows: the control module 308, upon receiving a set flow rate value, obtains the inlet pressure value under the current operating condition (i.e., the inlet pressure signal fed back by the inlet pressure measurement module 305), and, based on a pre-stored correspondence between the set flow rate value and the target position of the sealing surface of the valve core structure under multiple different inlet pressure values, obtains the target position of the sealing surface of the valve core structure corresponding to the received set flow rate value under the inlet pressure value obtained under the current operating condition. By pre-storing the above correspondence and directly calling the correspondence based on the inlet pressure value under the current operating condition when the set flow rate value is received to obtain the target position of the sealing surface of the valve core structure, the valve core structure can be quickly controlled to reach the target position, thereby improving the response speed of the mass flow controller 300 and meeting the operating condition requirements for high response speed of the mass flow controller 300. Based on this, by using the inlet pressure measurement module 305 to detect the inlet pressure value under the current operating conditions, when the inlet pressure value changes, the target position of the sealing surface of the valve core structure corresponding to the current set flow rate value can be obtained by calling the pre-stored correspondence mentioned above. This allows for more flexible adaptation to the usage environment of different process sites.

[0122] In some embodiments, the above-described correspondence can be stored in the memory of the control module as a data template. The set flow rate value is the actual target value to be achieved, which can be set according to specific needs.

[0123] As another technical solution, referring to Figure 20, this application embodiment also provides a flow control method for a mass flow controller, including:

[0124] S1. Upon receiving a set flow rate value, obtain the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow rate value;

[0125] S2. Receive the current position of the sealing surface of the valve core structure in real time, and control the valve core structure sealing surface to move relative to the valve port of the regulating valve assembly of the mass flow controller according to the current position and the target position, until it moves to the target position.

[0126] The flow control method of the mass flow controller provided in this application embodiment controls the movement of the valve core structure relative to the valve body assembly (i.e., controls the opening of the regulating valve) based on the target position of the sealing surface of the valve core structure corresponding to the set flow value and the current position of the sealing surface of the valve core structure detected in real time, until it moves to the target position of the sealing surface of the valve core structure to achieve flow control. Compared with the corresponding technology that indirectly obtains the opening of the regulating valve based on the magnitude of the valve voltage, the flow control accuracy and repeatability are higher, which can meet the requirements of high-end semiconductor manufacturing processes for control accuracy and repeatability.

[0127] In some embodiments, step S1 above may specifically include:

[0128] Obtain the target parameter value of the variable element corresponding to the set flow rate; the parameter value of the variable element is related to the distance from the valve core structure to the valve port.

[0129] The target parameter values ​​of the aforementioned variable element are used to characterize the target position of the sealing surface of the valve core structure. In some embodiments, the variable element includes a capacitor or a resistor. The parameter of the variable element is the capacitance or resistance value, and the target parameter value is the target value of the capacitance or resistance. During the synchronous movement of the aforementioned moving component with the valve core structure, the magnitude of the capacitance or resistance can change with the movement of the sealing surface of the valve core structure, thereby achieving a correlation between the magnitude of the capacitance or resistance and the opening degree of the regulating valve.

[0130] Step S2 above may specifically include:

[0131] The system receives the parameter detection values ​​of the aforementioned variable element in real time, and controls the valve core structure to move relative to the valve body assembly of the mass flow controller's regulating valve based on the parameter detection values ​​and the aforementioned parameter target values, until the parameter measurement value of the variable element reaches the parameter target value.

[0132] In embodiments where the variable element includes a capacitor or a resistor, the parameter detection value of the variable element is the detection value of the capacitor or resistor.

[0133] In other embodiments, step S1 may specifically include: acquiring the target distance of the position sensor itself relative to the valve port corresponding to the set flow rate value; the target distance is associated with the distance from the valve core structure to the valve port. Furthermore, step S2 may specifically include: receiving the current distance of the position sensor itself relative to the valve port detected in real time, and controlling the valve core structure to move relative to the valve port of the valve body assembly based on the current distance and the target distance, until the distance of the position sensor itself relative to the valve port reaches the target distance.

[0134] In some embodiments, as shown in FIG21, step S1 above may specifically include:

[0135] S11. Upon receiving the set flow rate value, obtain the inlet pressure value of the mass flow controller under the current operating conditions;

[0136] S12. Based on multiple pre-stored different inlet pressure values, set the correspondence between the flow rate value and the target position (e.g., the target value of capacitance or resistance) of the valve core structure's sealing surface, and obtain the target position of the valve core structure's sealing surface corresponding to the received set flow rate value at the inlet pressure value obtained under the current operating condition.

[0137] In existing technologies, when a set flow rate value is received, the mass flow controller using a thermal flow meter requires a long response time to reach a stable flow rate, making it unsuitable for applications with high response time requirements and unable to meet control needs under different operating conditions. To address this issue, this application's embodiments pre-store the aforementioned correspondence and, upon receiving a set flow rate value, directly invoke this correspondence based on the inlet pressure value under the current operating condition to obtain the target position (e.g., the target value of capacitance or resistance) of the valve core structure's sealing surface. This allows for rapid control of the valve core structure to reach the target position, thereby improving the response speed of the mass flow controller and meeting the requirements of operating conditions with high response speed demands. Furthermore, by obtaining the inlet pressure value under the current operating condition, when the inlet pressure value changes, the pre-stored correspondence can be invoked to obtain the target position of the valve core structure's sealing surface corresponding to the current set flow rate value and matching the inlet pressure value. This allows for more flexible adaptation to different process environments.

[0138] In some embodiments, the pre-stored inlet pressure values ​​can collect a sufficient number of data points within a specified numerical range to ensure sufficient resolution, so that the acquired inlet pressure values ​​under the current operating conditions can be retrieved from the pre-stored correspondence. The specified numerical range can be determined based on experience and customer needs. Of course, in practical applications, a linearized model can also be established for the inlet pressure value, the set flow rate value, and the target position of the valve core structure's sealing surface (e.g., the target value of capacitance or resistance), so that any inlet pressure value and set flow rate value can be output by the pre-stored linearized model as the target position of the valve core structure's sealing surface.

[0139] In some embodiments, when the currently received set flow rate value is not pre-stored, in step S12 above, interpolation can be used to obtain the target position (e.g., target value of capacitance or resistance) of the sealing surface of the valve core structure corresponding to the received set flow rate value under the current operating conditions at the inlet pressure value. Interpolation is a method of obtaining a continuous curve by interpolating a continuous function based on known discrete data points. This continuous curve covers all known discrete data points, and approximate values ​​for points other than the known discrete data points can be estimated using this continuous curve. Specifically, when the currently received set flow rate value is not pre-stored, by using the above interpolation method, a continuous curve relating the set flow rate value and the target position of the sealing surface of the valve core structure can be calculated. This continuous curve covers all pre-stored set flow rates, and the target position of the sealing surface of the valve core structure corresponding to the received set flow rate value can be obtained based on this continuous curve. Since the specific implementation of obtaining the continuous curve using interpolation is a well-known technology, it will not be elaborated here.

[0140] Since the target position (e.g., the target value of capacitance or resistance) of the valve core structure's sealing surface obtained using the above interpolation method is an estimated value, errors may occur in the actual flow rate value output by the mass flow controller. To address this issue, in some embodiments, after step S2 above, the flow control method further includes:

[0141] Determine whether the actual flow rate value output by the mass flow controller is within the error range corresponding to the set flow rate value;

[0142] If so, the process ends;

[0143] If not, compare the actual flow rate with the set flow rate, and adjust the target value of the capacitor according to the comparison result. Then return to execute step S2 above, and the target position in the returned step S2 is the adjusted target position.

[0144] It is easy to understand that when returning to execute step S2 above, the target position of the sealing surface of the valve core structure (e.g., the target value of capacitance or resistance) is the value after adjusting the original target value according to the comparison results above. The adjustment amount for adjusting the original target position can be a fixed value. Whether the adjustment amount is an increment or a decrement can be determined based on whether the actual flow rate is greater than or less than the set flow rate.

[0145] In some embodiments, the error range corresponding to the flow rate value is set to, for example, ±1%.

[0146] The step of determining whether the actual flow rate value output by the mass flow controller is within the error range corresponding to the set flow rate value is used to check whether the flow accuracy is within the preset accuracy threshold (i.e., the error range corresponding to the set flow rate value) after controlling the opening of the regulating valve through the above step S2. If it exceeds the preset accuracy threshold, after correcting the target position of the sealing surface of the valve core structure (e.g., the target value of capacitance or resistance), the process returns to step S2 and controls the valve core structure to move relative to the valve port of the valve body assembly with the corrected target position. This process is iterated until the flow accuracy is within the preset accuracy threshold, at which point the process ends.

[0147] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this application, and this application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this application, and these modifications and improvements are also considered to be within the scope of protection of this application.

Claims

1. A regulating valve, wherein, The device includes a valve body assembly, a valve core assembly, and a position detection device. The valve body assembly has a valve port. The valve core assembly includes a valve core structure with a sealing surface. The valve core structure is configured to allow the sealing surface to move relative to the valve body assembly in a direction close to or away from the valve port, so as to open or close the valve port and regulate the flow rate of fluid through the valve port. The position detection device is used to detect the position of the sealing surface relative to the valve port.

2. The regulating valve according to claim 1, wherein, The position detection device includes a moving component and a parameter detection unit, wherein the moving component is connected to the valve core structure, and the moving component is equipped with a variable element, the parameter of which changes with the movement of the sealing surface; The parameter detection unit is used to detect the parameter magnitude of the variable element.

3. The regulating valve according to claim 2, wherein, The moving component includes a fixed member and a moving member, wherein the fixed member and the moving member constitute the variable element; the fixed member is connected to the valve body assembly; and the moving member is connected to the valve core structure.

4. The regulating valve according to claim 3, wherein, Both the fixing member and the moving member are electrode plates, and the variable element formed by the fixing member and the moving member is a capacitor; The parameter detection unit is used to detect the capacitance value of the capacitor.

5. The regulating valve according to claim 3, wherein, There are two fixing members, both of which are electrode plates and are arranged opposite to each other along the moving direction of the sealing surface, and both are connected to the valve body assembly; the moving member is an electrode plate and is located between the two fixing members, and the variable element formed by the two fixing members and the electrode plate is a first capacitor and a second capacitor, respectively. The parameter detection unit is used to detect the size of the first capacitor and the second capacitor.

6. The regulating valve according to claim 3, wherein, The valve core assembly further includes a valve core mounting component, which is fixedly connected to the valve body assembly and located on the side of the valve body assembly where the valve port is located; the valve core structure includes a valve core rod, which is movably connected to the valve core mounting component and extends along the moving direction of the sealing surface; the sealing surface is located at the end of the valve core rod near the valve port; The fixing component is fixedly disposed relative to the valve core mounting component.

7. The regulating valve according to claim 6, wherein, The valve core mounting component is provided with a through space that extends through the valve core mounting component along the moving direction of the sealing surface; the valve core rod is movably inserted through the through space; The valve core structure also includes an elastic element that is sealed between the outer peripheral surface of the valve core rod and the inner wall of the through space; The fixing member is located on the side of the valve core mounting member opposite to the valve body assembly, and an accommodating space is formed between the fixing member and the valve core mounting member; The movable component is fixedly connected to the valve core rod and is at least partially located in the accommodating space.

8. The regulating valve according to claim 7, wherein, The regulating valve also includes a drive assembly for moving the valve core rod; The fixing member has a clearance part at the position corresponding to the valve core rod, and the end of the valve core rod away from the valve port is connected to the drive assembly through the clearance part.

9. The regulating valve according to claim 6, wherein, The regulating valve also includes a drive assembly for moving the valve core structure; The valve core structure further includes a moving component, and the end of the valve core rod away from the valve port is throttle-connected to the moving component; the moving component is elastically connected to the drive assembly; A portion of the moving part is used as the moving component.

10. The regulating valve according to claim 1, wherein, The regulating valve further includes a drive assembly and a controller, wherein the drive assembly is connected to the valve core structure and is used to drive the sealing surface to move relative to the valve port of the valve body assembly; The controller is used to obtain the target position of the sealing surface corresponding to the set flow rate value when a set flow rate value is received; to receive the current position of the sealing surface detected by the position detection device in real time; and to control the drive assembly to drive the sealing surface to move relative to the valve port of the valve body assembly according to the current position of the sealing surface and the target position, until the sealing surface moves to the target position.

11. The regulating valve according to claim 4 or 5, wherein, The distance between the fixed component and the moving component varies within a range of 20 micrometers or more and 90 micrometers or less.

12. A mass flow controller, wherein, It includes a main body and a regulating valve as described in any one of claims 1-11 disposed on the main body.

13. A flow control method for a mass flow controller, comprising: Upon receiving a set flow rate value, the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow rate value is obtained; The current position of the sealing surface is received in real time, and based on the current position of the sealing surface and the target position, the valve port of the sealing surface relative to the valve body assembly of the regulating valve of the mass flow controller is controlled to move until it moves to the target position.

14. The flow control method according to claim 13, wherein, The step of obtaining the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow value upon receiving the set flow value includes: Obtain the target parameter value of the variable element corresponding to the set flow rate value; the parameter value of the variable element is related to the distance from the sealing surface to the valve port; The step of receiving the current position of the sealing surface in real time, and controlling the movement of the sealing surface relative to the valve body assembly of the regulating valve of the mass flow controller, based on the current position of the sealing surface and the target position, until it moves to the target position, includes: The system receives the parameter detection values ​​of the variable element in real time, and controls the movement of the sealing surface relative to the valve port of the valve body assembly based on the parameter detection values ​​and the target parameter values, until the parameters of the variable element reach the target parameter values.

15. The flow control method according to claim 13 or 14, wherein, The step of obtaining the target position of the sealing surface of the valve core structure of the mass flow controller corresponding to the set flow value upon receiving the set flow value includes: Upon receiving the set flow rate value, the inlet pressure value of the mass flow controller under the current operating conditions is obtained; Based on the pre-stored correspondence between the set flow rate value and the target position of the sealing surface under multiple different inlet pressure values, the target position of the sealing surface corresponding to the received set flow rate value under the current operating condition is obtained at the inlet pressure value.

16. The flow control method according to claim 13 or 14, wherein, After controlling the sealing surface to move relative to the valve port of the valve body assembly until it reaches the target position, the flow control method further includes: Determine whether the actual flow rate value output by the mass flow controller is within the error range corresponding to the set flow rate value; If so, the process ends; If not, compare the actual flow rate value with the set flow rate value, and adjust the target position of the sealing surface according to the comparison result. Then return to the step of receiving the current position of the sealing surface in real time, and controlling the sealing surface to move relative to the valve port of the valve body assembly according to the current position of the sealing surface and the target position until it moves to the target position. The target position in the returned step is the adjusted target position.

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