A vacuum pumping screen device

Abstract

The application belongs to the technical field of vacuum, and discloses a vacuum pumping screen device, which comprises a lower shell, a cylindrical upper shell, a mounting pipeline and a transmission rod. The lower shell is installed at a pumping port in a vacuum chamber and has a second vent on a side wall thereof. The upper shell is a cylindrical shell with a closed upper end and is sleeved on the outside of the lower shell. The upper shell has a first vent on a side wall thereof. The mounting pipeline is branched from a vacuum pipeline connecting the vacuum pump and the pumping port of the vacuum chamber. One end of the transmission rod is fixedly connected with the lower shell and the upper shell, and the other end of the transmission rod is connected with an output end of a driving mechanism outside the vacuum chamber. The driving mechanism is used for driving the upper shell to move, so as to adjust the opening degree of an actual vent formed by the communication between the first vent and the second vent. The application can control the exhaust flow of the vacuum chamber, reduce the initial load of the vacuum pump, and prolong the service life of the vacuum pump.

Description

Technical Field

[0001] This invention belongs to the field of vacuum technology, and more specifically, relates to a vacuum pumping screen device. Background Technology

[0002] A vacuum environment is crucial in semiconductor manufacturing. It prevents wafer oxidation and contamination, ensuring chip quality and performance. A vacuum system typically consists of components such as a vacuum pump, control system, gas storage tank, and piping. Figure 2 In this system, a vacuum environment is created by the vacuum pump 200 drawing air from the vacuum chamber 100. The vacuum screen plays the following role in this complex vacuum system:

[0003] In this vacuum system, sometimes due to the inherent properties of the vacuum pump (such as a dry pump), when the vacuum pump unexpectedly stops working, contaminant particles may flow back into the vacuum chamber 100, which contaminates the chamber that has already reached a vacuum state, and this is very likely to cause particulate contamination to the silicon wafer.

[0004] Furthermore, the working environment inside the deposition equipment chamber is generally a vacuum, and ions are continuously generated within the chamber due to process requirements. These ions are widely present in the chamber and used for processes such as vapor deposition on the wafers inside the chamber. However, during the vacuum pump's suction process, a small amount of ions are also drawn into the vacuum pump. When these ions enter the vacuum pump, they can damage the pump blades, which over time significantly reduces the pump's performance and efficiency.

[0005] Therefore, it is essential to design a pumping screen to block contaminant particles in the return gas during an emergency stop of the vacuum pump. Currently, this is achieved by installing a pumping screen, such as... Figure 1 As shown, this pumping screen mainly includes a cover 10, support columns 20, filter rings 30, conductive gaskets 40, etc. Multiple support columns are arranged along the circumference, and the cover is fixed to the top of the support columns. Multiple filter rings are installed at intervals on the support columns, and the spaces between adjacent filter rings on adjacent support columns form vents. The vacuum pump pumps the vacuum chamber through these vents.

[0006] The pump screen is designed to be positioned between the valve and the chamber, and its installation location is as follows: Figure 2 As shown, the pumping screen can change the return flow direction at the pump inlet, effectively preventing contaminant particles from being directly blown onto the silicon wafer. Furthermore, it can intercept most of the ions and guide excess charge into the chamber, which is then transferred to the ground, effectively reducing the harmful effects of ions on the vacuum pump.

[0007] In addition, the pump screen prevents parts from falling into the vacuum pump while maintenance personnel are working. Since vacuum pumps are highly precise devices, the presence of the pump screen effectively protects them.

[0008] However, the applicant discovered that operating the vacuum pump at full load upon initial startup would damage its performance. Therefore, using a pumping screen to reduce the initial workload of the vacuum pump could effectively protect it. However, current exhaust port adjustments require opening the chamber, a complex process that prevents automatic adjustment during the manufacturing process.

[0009] Therefore, it is necessary to improve the pumping screen, which can not only ensure the vacuum state of the vacuum chamber and reduce the entry of ions into the vacuum pump and damage its blades, but also allow for adjustment of the vent size of the pumping screen during the process to protect the vacuum pump. Summary of the Invention

[0010] [Technical Issues]

[0011] To address the problems described above, the present invention aims to provide a vacuum pump screen delivery device that adjusts the actual air inlet size by comparing the detected flow rate of the vacuum pipeline with a preset flow rate value, thereby reliably regulating the working load of the vacuum pump and protecting the vacuum pump.

[0012] [Technical Solution]

[0013] This application provides a vacuum pumping screen delivery device, comprising:

[0014] The lower housing is cylindrical and is installed at the pump inlet inside the vacuum chamber. It has a second vent on its side wall for ventilation.

[0015] The upper shell is a cylindrical shape that is closed at the top and is fitted onto the outside of the lower shell. The side wall of the upper shell has a first vent for ventilation.

[0016] The installation pipeline branches off from the vacuum pipeline connecting the vacuum pump and the pumping port of the vacuum chamber;

[0017] The transmission rod has one end passing through the lower housing and fixedly connected to the upper housing, and the other end passing through the mounting pipe and connecting to the output end of the drive mechanism outside the vacuum chamber.

[0018] The driving mechanism is used to drive the upper housing to move, thereby adjusting the opening degree of the actual vent formed by the connection between the first vent and the second vent.

[0019] Optionally, the upper shell is cylindrical, and multiple rows of first vents are formed in the axial and circumferential directions of the upper shell;

[0020] The lower housing is cylindrical, with multiple rows of second vents formed in the axial and circumferential directions.

[0021] Optionally, the first vent of the upper housing and the second vent of the lower housing overlap in axial position.

[0022] Optionally, the first vent of the upper housing and the second vent of the lower housing are of the same size.

[0023] Optionally, the end of the transmission rod that extends out of the upper housing is fastened with a fastener.

[0024] Optionally, the drive mechanism is a rotary motor, and the other end of the transmission rod is connected to the output shaft of the rotary motor via a coupling.

[0025] Optionally, the transmission rod is installed in the installation pipeline via a magnetohydrodynamic seal.

[0026] Optionally, a flow sensor is also installed on the vacuum pipeline. When the detected value of the flow sensor is greater than the preset flow value, the drive mechanism adjusts the actual air inlet of the vacuum pump screen device to be smaller; when the detected value of the flow sensor is less than the preset flow value, the drive mechanism adjusts the actual air inlet of the vacuum pump screen device to be larger.

[0027] Optionally, a control module is also included. The control module is connected to the flow sensor and the drive mechanism. When the detection value of the flow sensor is consistent with the preset flow value, the control module sends an instruction to perform process processing; when they are inconsistent, it sends an instruction to the drive mechanism to adjust the opening of the actual vent.

[0028] Optionally, the lower housing is a cylindrical shape with the upper end closed.

[0029] [Beneficial Effects]

[0030] This application allows the actual vent to change accordingly by rotating the upper and lower housings, thereby controlling the exhaust flow rate. This reduces the initial load on the vacuum pump, decreases wear and tear during operation, and extends the pump's lifespan.

[0031] This application can isolate the vacuum environment from the external environment through the magnetohydrodynamic sealing and transmission parts, and the drive mechanism can transmit power to the upper shell in the vacuum chamber in the atmospheric environment. Attached Figure Description

[0032] Figure 1 This is a three-dimensional schematic diagram of a pumping screen in the prior art.

[0033] Figure 2 This is a schematic diagram of a vacuum pump returning gas.

[0034] Figure 3 This is a three-dimensional schematic diagram of the upper housing according to an embodiment of this application.

[0035] Figure 4 This is a three-dimensional schematic diagram of the lower housing according to an embodiment of this application.

[0036] Figure 5 This is a three-dimensional schematic diagram of the actual vent being half-open in an embodiment of this application.

[0037] Figure 6 This is a three-dimensional schematic diagram of the actual vent fully open according to an embodiment of this application.

[0038] Figure 7 This is a three-dimensional schematic diagram of the transmission rod according to an embodiment of this application.

[0039] Figure 8 This is a schematic diagram of the installation of the vacuum pumping screen device according to an embodiment of this application.

[0040] Figure 9 This is a feedback control flowchart of the vacuum pumping screen device according to an embodiment of this application.

[0041] [Brief Explanation of the Labels in the Attached Figures]

[0042] 10: Cap 20: Support Column

[0043] 30: Filter ring; 40: Conductive gasket

[0044] 100: Vacuum chamber; 200: Vacuum pump

[0045] 210: Flow sensor; 300: Upper housing

[0046] 310: First vent 400: Lower housing

[0047] 410: Second vent 500: Transmission rod

[0048] 600: Installation piping; 700: Magnetohydrodynamic seal.

[0049] 800: Drive mechanism Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after the connection. The directional terms mentioned in the embodiments of this application, such as "upper," "lower," "inner," "outer," "forward," and "backward," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0052] Please refer to Figure 2 The vacuum pumping screen device of this embodiment includes an upper housing 300, which is disposed inside the vacuum chamber 100 and is a cylindrical shape with a closed upper end, and has a first vent 310 for ventilation on its side wall; a lower housing 400, which is disposed at the pumping port inside the vacuum chamber, is a cylindrical shape with a closed upper end, and is fitted inside the upper housing 300, and has a second vent 410 for ventilation on its side wall; an installation pipe 600, which branches off from the vacuum pipe connecting the vacuum pump 200 and the pumping port of the vacuum chamber; and a transmission rod 500, one end of which passes through the lower housing and is fixedly connected to the upper housing 300, and the other end of which passes through the installation pipe and is connected to the output end of the drive mechanism outside the vacuum chamber.

[0053] The upper housing 300 may be cylindrical, closed at the top and open at the bottom, with one or more first vents 310 provided on its sidewall. Each first vent 310 may be a hole provided in the sidewall of the upper housing 300. For example, each first vent 310 may be an elongated strip extending in the circumferential direction, and multiple elongated first vents 310 may be spaced apart along the axial direction of the upper housing to form a hole array, and multiple such hole arrays may be spaced apart in the circumferential direction to form multiple rows and columns of first vents 310 in the axial and circumferential directions. However, this embodiment does not exclude the possibility of only one hole array, or even only one first vent 310.

[0054] The lower housing 400 may be cylindrical, closed at the upper end and open at the lower end, with one or more second vents 410 provided on its side wall. Each second vent 410 may be a hole provided in the side wall of the lower housing 400. For example, each second vent 410 may be an elongated strip extending in the circumferential direction, and multiple elongated second vents 410 may be spaced apart along the axial direction to form a hole array, and multiple such hole arrays may be spaced apart in the circumferential direction to form multiple rows and columns of second vents 410 in the axial and circumferential directions. However, this embodiment does not exclude the possibility of only one hole array, or even only one second vent 410.

[0055] However, this application does not preclude the possibility that the upper end of the lower housing 400 may not be sealed, but rather that the upper end of the lower housing may be sealed after the upper housing 300 and the lower housing 400 are assembled. The specific structure will not be described here.

[0056] The upper housing is fastened to the lower housing through its lower opening, or the lower housing is fitted inside the upper housing 300 and is rotatably fitted inside the upper housing 300. The first vent 310 of the upper housing 300 and the second vent 410 of the lower housing 400 overlap axially. Specifically, for example, if the upper housing 300 and the lower housing 400 are vertically arranged (i.e., their axes are vertical), then the first vent 310 and the second vent 410 are at the same vertical height.

[0057] The dimensions of the first vent 310 of the upper housing 300 and the second vent 410 of the lower housing 400 can be the same. For example, if the dimensions of the first vent 310 are 10cm x 2cm, then the dimensions of the second vent 410 are also 10cm x 2cm. Thus, when the upper housing 300 rotates, the first vent 310 and the second vent can change from being completely disconnected to partially connected, and finally to being completely connected. The actual gas channel formed by the connection between the first vent and the second vent is called the actual vent. When completely disconnected, the connection between the vacuum pump and the vacuum chamber is completely sealed, meaning the actual vent is at its minimum. When partially connected, the vacuum pump and the vacuum chamber are in a partially connected state, and the actual vent is between its maximum and minimum size. When completely connected, the vacuum pump and the vacuum chamber are in a maximum connected state, and the actual vent is at its maximum size.

[0058] Of course, the dimensions of the first vent 310 and the second vent 410 can also be different. For example, the length of the first vent 310 may be greater than the length of the second vent 410, and the circumferential distance between the second vents 410 may be greater than the length of the first vent 310. For instance, the dimensions of the first vent 310 may be 10cm x 2cm, and the dimensions of the second vent 410 may be 8cm x 2cm. Furthermore, if the circumferential distance between the second vents 410 is greater than 10cm, then by rotating the upper housing 300, the first vent 310 completely covers the second vent 410, and the vacuum pump and vacuum chamber are in a state of maximum communication, at which point the actual vent is at its maximum. If the first vent 310 and the second vent 410 do not overlap at all, then the communication between the vacuum pump and the vacuum chamber is closed, at which point the actual vent is at its minimum.

[0059] like Figure 4 The first vent 310 is partially blocked, while the second vent 410 is partially blocked, meaning the actual vent is only half-open. Figure 5 It is the state where the first vent 310 and the second vent 410 are fully connected, and the actual vent is at its maximum.

[0060] One end of the transmission rod 500 is threaded, allowing it to pass sequentially through the lower housing 400 and the upper housing 300. A nut is used to secure the end of the rod that extends out of the upper housing 300, thereby fixing the upper housing 300 to the transmission rod 500. Of course, the threaded connection is merely exemplary, and this application does not preclude the possibility of connections using other methods such as welding or riveting.

[0061] A mounting pipe 600 branches off from the vacuum pipe connecting the vacuum pump 200 and the vacuum chamber 100. The other end of the transmission rod 500 passes through the mounting pipe 600 and connects to the output end of the drive mechanism 800. The drive mechanism 800 can be a rotary motor. The other end of the transmission rod 500 can be connected to the output shaft of the rotary motor via a key, or alternatively, via a coupling. Alternatively, the rotary mechanism can be connected to a reducer via a rotary motor, and the reducer can then be connected to the other end of the transmission rod 500 via a coupling.

[0062] The drive mechanism rotates the transmission rod 500, thereby controlling the relative position of the first vent 310 of the upper housing and the second vent 410 of the lower housing, thus controlling the connection between the first vent 310 and the second vent 410, and adjusting the flow rate of the vacuum pump. The gas velocity in the cavity is adjusted when passing through the vents before reaching the vacuum pump below. This reduces the initial load on the vacuum pump, reduces wear and tear during operation, and extends the pump's lifespan.

[0063] Specifically, when the vacuum pump is initially started, the drive mechanism drives the transmission rod 500 to rotate, causing the first vent 310 to partially block the second vent 410, thereby reducing the flow rate of the vacuum pump and lowering its initial workload, which effectively protects the vacuum pump. Then, the connection area between the first vent 310 and the second vent 410 can be gradually increased, meaning the actual vent area becomes larger, thus gradually increasing the flow rate of the vacuum pump.

[0064] Furthermore, the transmission rod 500 is installed in the installation pipe 600 via a magnetic fluid seal 700. The magnetic fluid seal and transmission components can isolate the vacuum environment from the external environment, allowing the rotary motor to transmit power to the upper housing in the vacuum chamber from the atmospheric environment. When the magnetic fluid is injected into the gap of the magnetic field, it can fill the entire gap, forming a "liquid O-ring" that provides a reliable dynamic seal.

[0065] When the rotary motor rotates, the rotation amplitude is transmitted to the transmission rod 500 through the magnetohydrodynamic seal 700, which in turn drives the upper housing 300 to rotate. The relative rotation of the upper housing 300 and the lower housing 400 causes a corresponding change in the actual vent, thereby controlling the exhaust flow rate. The gas flow rate in the cavity is adjusted when passing through the exhaust port before reaching the vacuum pump 200 below. This reduces the initial load on the vacuum pump 200, reduces the wear and tear on the vacuum pump during operation, and extends the life of the vacuum pump. The magnetohydrodynamic seal and transmission components isolate the vacuum environment from the external environment, allowing the drive mechanism to transmit power to the upper housing 300 in the vacuum chamber 100 in an atmospheric environment.

[0066] It should be noted that the above method adjusts the connection between the first vent 310 and the second vent 410 by rotating the upper and lower housings relative to each other. This application is not limited to adjustment via rotation alone; linear motion can also be used. For example, the upper housing may be connected to a linear motor or other linear drive mechanism, and the upper and lower housings may move relative to each other axially to adjust the connection between the first vent 310 and the second vent 410. Specific details will not be elaborated here. The following explanation uses a rotary motor as the driving mechanism.

[0067] In some embodiments, a flow sensor 210 is also installed on the vacuum pipeline. The flow sensor 210 can detect the flow rate pumped by the vacuum pump. By comparing the detected value of the flow sensor with a preset flow rate value, the drive mechanism can be adjusted. Taking a rotary motor as an example, when the flow rate in the vacuum pipeline is greater than the preset flow rate value, the rotary motor is rotated one step in the reverse direction through negative feedback adjustment, reducing the actual air vent of the vacuum pump screen device, thus gradually decreasing the flow rate. When the detected value of the flow sensor is less than the preset flow rate value, the adjustment is reversed, the rotary motor rotates one step in the forward direction, increasing the actual air vent of the vacuum pump screen device, thus gradually increasing the flow rate.

[0068] It may also include a control module, which is connected to the flow sensor 210 and the drive mechanism. Figure 9 This is a feedback control flowchart of the vacuum pumping screen device according to an embodiment of this application. Refer to the following... Figure 9 The feedback control process is explained below. The control module reads the preset flow rate value X and the flow rate value Y from the flow sensor 210 in real time. It compares the preset flow rate value X with the flow rate value Y from the flow sensor 210. If they match, normal process handling proceeds. If they don't match, the module further determines the magnitude of X and Y. If X is greater than Y, the rotary motor rotates forward one step, causing the upper housing to rotate and increasing the overlap between the first vent 310 and the second vent 410, thus increasing the actual vent size and consequently increasing the vacuum pump flow rate. If X is less than Y, the rotary motor rotates in reverse one step, causing the upper housing to rotate and decreasing the overlap between the first vent 310 and the second vent 410, thus decreasing the actual vent size and consequently decreasing the vacuum pump flow rate.

[0069] In some embodiments, since the actual mechanical transmission is not ideal, errors that may occur during the actual adjustment process can be analyzed and measures can be taken. The processes that may generate errors include:

[0070] (1) The error between the actual rotation amount and the ideal rotation amount of the rotating motor after receiving the rotation signal;

[0071] (2) The error between the actual transmission amount and the ideal transmission amount of the transmission rod after the rotary motor rotates;

[0072] (3) Error between the actual relative rotation and the ideal rotation between the upper and lower shells.

[0073] Since the transmission rod and the upper and lower housings are inside a high-vacuum chamber, it is difficult to reduce the error by directly measuring the rotation / transmission amount. A sensor (such as a grating disk) for detecting the rotation amount can be set at the rotary motor, and the rotary motor can be controlled by feedback to reduce the rotation error.

[0074] The transmission rod should minimize errors caused by rotational deflection and airflow disturbance. For example, using rigid materials and surface treatments can reduce the impact of rotational deflection and airflow disturbance.

[0075] To minimize friction caused by the relative rotation of the upper and lower housings and errors caused by airflow disturbances, high machining precision is required at the relative friction points, and the friction area between the upper and lower housings should be minimized as much as possible.

[0076] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications are all within the protection scope of the claims of the present invention.

Claims

1. A vacuum pumping screen delivery device, characterized in that, include: The lower housing is cylindrical and is installed at the pump inlet inside the vacuum chamber. It has a second vent on its side wall for ventilation. The upper shell is a cylindrical shape with a closed upper end, and is fitted onto the outside of the lower shell. The side wall of the upper shell has a first vent for ventilation. The installation pipeline branches off from the vacuum pipeline connecting the vacuum pump and the pumping port of the vacuum chamber; The transmission rod has one end passing through the lower housing and fixedly connected to the upper housing, and the other end passing through the mounting pipe and connecting to the output end of the drive mechanism outside the vacuum chamber. The driving mechanism is used to drive the upper housing to move, thereby adjusting the opening degree of the actual vent formed by the connection between the first vent and the second vent. The upper shell is cylindrical, and multiple rows of first vents are formed in the axial and circumferential directions of the upper shell; The lower housing is cylindrical, with multiple rows of second vents formed in the axial and circumferential directions.

2. The vacuum pumping screen device according to claim 1, characterized in that, The first vent of the upper housing overlaps with the second vent of the lower housing along the axial direction.

3. The vacuum pumping screen device according to claim 2, characterized in that, The first vent of the upper housing and the second vent of the lower housing are the same size.

4. The vacuum pumping screen device according to claim 1, characterized in that, The end of the transmission rod that protrudes from the upper housing is fastened with fasteners.

5. The vacuum pumping screen device according to claim 1, characterized in that, The drive mechanism is a rotary motor, and the other end of the transmission rod is connected to the output shaft of the rotary motor via a coupling.

6. The vacuum pumping screen device according to claim 1, characterized in that, The transmission rod is installed in the installation pipeline via a magnetohydrodynamic seal.

7. The vacuum pumping screen device according to claim 1, characterized in that, A flow sensor is also installed on the vacuum pipeline. When the flow sensor detects a value greater than the preset flow value, the drive mechanism adjusts the actual air inlet of the vacuum pump screen device to be smaller; when the flow sensor detects a value less than the preset flow value, the drive mechanism adjusts the actual air inlet of the vacuum pump screen device to be larger.

8. The vacuum pumping screen device according to claim 7, characterized in that, It also includes a control module, which is connected to the flow sensor and the drive mechanism. When the flow sensor's detection value matches the preset flow value, the control module sends an instruction to perform process processing; when they do not match, it sends an instruction to the drive mechanism to adjust the opening of the actual vent.

9. The vacuum pumping screen device according to claim 1, characterized in that, The lower shell is a cylindrical shape with the upper end closed.

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