A method for detecting vibration value of a magnetic suspension molecular pump turbine at high temperature, a detection system and application

Abstract

This application discloses a method, system, and application for detecting the vibration value of a magnetic levitation molecular pump turbine at high temperature. It belongs to the field of molecular pump testing. The key technical point is that it is a method for determining the vibration value of the turbine at any temperature T by detecting the vibration value of the turbine at room temperature. The method includes the following steps: S100, obtaining the vibration value δ of the magnetic levitation molecular pump under test at room temperature T0. T0 S200: Obtain the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test, and obtain the vibration values ​​of n molecular pumps at temperatures T0 and T from the dataset Q; S300: Solve for the vibration value δ of the magnetic levitation molecular pump under test at temperature T. T The technical solution of this application can eliminate the testing time of high-temperature dynamic balancing test, and the vibration value of turbine at high temperature can be known by performing dynamic balancing test at room temperature.

Description

Technical Field

[0001] This application relates to the field of molecular pump testing, and more specifically, to a method, system, and application for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperatures. Background Technology

[0002] When magnetically levitated molecular pumps are used in semiconductor etching equipment, they must possess anti-deposition performance. To address this, many manufacturers have developed anti-deposition magnetically levitated molecular pumps. The key to this anti-deposition performance lies in actively heating the components within the pump that come into contact with the process gas (such as turbine blades and stator), maintaining their temperature above the sublimation temperature (or condensation temperature) of the process byproducts, ensuring they are always drawn away in gaseous form.

[0003] According to T / CGMA0603-2021, "Stability and Environmental Performance Classification Specification for Magnetic Levitation Molecular Pumps," the radial displacement vibration value of the turbine rotor is one of the key indicators of a molecular pump. However, the above vibration value is the result of the turbine operating at room temperature. In semiconductor etching processes, however, the turbine operates at very high temperatures, and temperature has a significant impact on the vibration value. Therefore, for magnetic levitation molecular pumps used in semiconductor etching equipment, in addition to requiring the vibration value at room temperature to be less than a threshold, the vibration value at high temperatures under normal operating conditions should also be limited (with a limit of 0.05 μm).

[0004] Regarding vibration testing at high temperatures, the following explanations will cover the testing fixtures and the testing process.

[0005] (1) Testing fixtures.

[0006] The radial displacement vibration values ​​of the turbine at both room temperature and high temperature can be measured using the testing fixture CN119063986A. This involves installing a turbine temperature sensor, X-axis and Y-axis vibration sensors on the upper end face (the vibration value of the upper end face is generally greater than that of the lower end face, so only the vibration sensor on the upper end face needs to be retained), and a dynamic balancing analyzer on the molecular pump that has already been stress-relieved.

[0007] (2) Testing process.

[0008] A flow rate of 500 sccm to 1000 sccm is applied to the magnetically levitated molecular pump after the turbine stress has been removed. Under the impact of the gas, the temperature of the turbine gradually rises.

[0009] At the above gas flow rate, the effect of aerodynamic pressure on the radial displacement of the rotor can be basically ignored (aerodynamic pressure only has a significant effect under high flow rate).

[0010] Figure 1The turbine temperature-time curve is shown. It reveals that the turbine temperature rises very slowly. This indicates that the vibration test time for the magnetic levitation molecular pump at high temperatures is excessively long. Summary of the Invention

[0011] The purpose of this application is to address the shortcomings of the prior art by providing a method and system for detecting the vibration value of a magnetic levitation molecular pump turbine at high temperatures.

[0012] The technical solution of this application is as follows: A method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, which is used to detect the vibration value of the turbine at any temperature T, includes the following steps: S100, Obtain the vibration value δ of the magnetically levitated molecular pump under test at room temperature T0. T0 ; S200, obtain the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test. Q records the vibration values ​​of n molecular pumps of the same model at different temperatures. Obtain the vibration values ​​of n molecular pumps at temperatures T0 and T from dataset Q. Let the vibration value of any i-th molecular pump at temperatures T0 and T be denoted as δ. T0-i δ T-i ; S300, Solve for the vibration value δ of the magnetically levitated molecular pump under test at temperature T. T : .

[0013] A method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, which is used to detect the vibration value of the turbine at any temperature T, includes the following steps: S100, Obtain the vibration value δ of the magnetically levitated molecular pump under test at room temperature T0. T0 ; S200, obtain the temperature vibration value dataset Q of the same model of the magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; Q = {q1, q2, ..., q...} i ……q n}; where q i This is a subset of the temperature-vibration values ​​of the i-th molecular pump in dataset Q, which records the temperature-vibration values ​​at temperature T. i-1 T i-2 ...T i-m The corresponding vibration value δ Ti-1 δ Ti-2 ……δ Ti-m ; S300, solve for the change in vibration value k1~k caused by unit temperature of n molecular pumps. n; For any i-th molecular pump, the change in vibration value k caused by unit temperature i In other words, its acquisition method is: using (T) i-1 δ Ti-1 (T) i-2 δ Ti-2 )……(T) i-m δ Ti-m The data points are used for linear fitting, and the slope is k. i ; S400, obtain the vibration values ​​δ of n molecular pumps at temperature T0 from the Q dataset. T0-i ; S500, calculate the vibration value δ of the magnetically levitated molecular pump under test at temperature T. T : .

[0014] Furthermore, the range of T0 is [20°C, 30°C].

[0015] Furthermore, T is greater than T0 and less than or equal to 100°C.

[0016] Furthermore, T 1-1 =T 2-1 =……=T n-1 And T 1-1 The range is [20°C, 30°C].

[0017] Furthermore, T 1-m =T 2-m =……=T n-m .

[0018] A system for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, comprising: a first storage unit, a second storage unit, and a high-temperature vibration value solving unit; The first storage unit is used to store the vibration value δ of the magnetically levitated molecular pump under test at room temperature T0. T0 ; The second storage unit is used to store the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; The high-temperature vibration value solving unit is used to solve the vibration value δ of the magnetic levitation molecular pump under test at temperature T. T The solution method is as follows: ; δ T0-i δ T-i Let T and T represent the vibration values ​​of any i-th molecular pump in the dataset Q at temperatures T0 and T, respectively.

[0019] A system for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, comprising: a first storage unit, a second storage unit, and a high-temperature vibration value solving unit; The first storage unit is used to store the vibration value δ of the magnetically levitated molecular pump under test at room temperature T0. T0 ; The second storage unit is used to store the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; Q = {q1, q2, ..., q...} i ……q n}; where q i This is a subset of the temperature-vibration values ​​of the i-th molecular pump in dataset Q, which records the temperature-vibration values ​​at temperature T. i-1 T i-2 ...T i-m The corresponding vibration value δ Ti-1 δ Ti-2 ……δ Ti-m ; The high-temperature vibration value solving unit is used to solve the vibration value δ of the magnetic levitation molecular pump under test at temperature T. T The solution method is as follows: ; δ T0-i k i Let represent the vibration value of any i-th molecular pump among the n molecular pumps in dataset Q at time T0, and the change in vibration value caused by a unit temperature, respectively. k i The method of obtaining it is: using (T) i-1 δ Ti-1 (T) i-2 δ Ti-2 )……(T) i-m δ Ti-m The data points are used for linear fitting, and the slope is k. i .

[0020] An application of a method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperatures, wherein the aforementioned detection method is used to detect the vibration value δ of the turbine at 100°C. 100 It is used to determine whether the vibration value of a magnetically levitated molecular pump under normal high-temperature operating conditions meets the high-temperature radial vibration requirements: if δ 100 Vibration threshold value [δ] corresponding to temperatures below 100°C 阈值 If the high-temperature radial vibration requirement is met, then the high-temperature radial vibration requirement is not met.

[0021] Furthermore, the vibration threshold value [δ] corresponding to 100°C. 阈值 It is 0.05μm.

[0022] The beneficial effects of this application are as follows: (1) This application develops a method for detecting the vibration value of a magnetic levitation molecular pump turbine at high temperature. It is a method for detecting the vibration value of the turbine at any temperature T by detecting the vibration value of the turbine at room temperature. It is an indirect method for detecting the vibration value of the turbine at high temperature. It can eliminate the testing time of high temperature dynamic balancing test, and the vibration value of the turbine at high temperature can be known by performing dynamic balancing test at room temperature.

[0023] (2) This application proposes two schemes.

[0024] (2.1) The theoretical basis of the first scheme is as follows: (δ) T -δ T0 ) / (T-T0)=δ T0 ·α,δ T δ T0 These represent the vibration values ​​at temperature T and room temperature T0, respectively. Based on this, the following scheme is proposed: Based on the vibration value δ of the magnetic levitation molecular pump under test at T0 T0 Solve for its vibration value δ at time T. T : ; Where, δ T-i δ T0-i It is the vibration value of the i-th molecular pump among n identical magnetic levitation molecular pumps at T0 and T.

[0025] (2.2) The theoretical basis of the second scheme is as follows: δ T =δ T0 ·α·T+(δ T0 -δ T0 ·α·T0). From the above equation, it can be seen that there is a linear relationship between the vibration value and temperature. That is, by performing a linear fit with temperature as the independent variable and vibration value as the dependent variable, δ can be obtained. T0 • α. Compared to the first approach, which uses only two data points per molecular pump in the dataset, the second approach utilizes all information from each molecular pump in the dataset. This is based on the vibration value δ of the magnetically levitated molecular pump under test at T0. T0 Solve for its vibration value δ at time T. T : ; Where, δ T0-i k i It is the vibration value of the i-th molecular pump among n identical magnetic levitation molecular pumps at T0, and the slope of the temperature-vibration value is obtained by linear fitting. Attached Figure Description

[0026] The present application will be further described in detail below with reference to the embodiments in the accompanying drawings, but this does not constitute any limitation on the present application.

[0027] Figure 1 This is the turbine temperature-time relationship curve (molecular pump model: CAS Instrument CXF320 / 3001CV molecular pump; air flow rate: 1000scm).

[0028] Figure 2 This is an approximate structural diagram of the rotor structure of a magnetically levitated molecular pump when describing the unbalanced quantity and vibration value.

[0029] Figure 3 This is a typical temperature-vibration relationship curve for a molecular pump turbine. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] <Theoretical Analysis 1> For the rotor structure of a magnetically levitated molecular pump, its vibration value can be understood as follows: (1) The radial displacement vibration of the rotor originates from the imbalance, that is, there is a small distance between the geometric center O of the rotor and the center of mass A. In other words, the centrifugal force caused by the mass eccentricity is the source of the radial displacement vibration of the rotor.

[0032] (2) The rotor structure of the magnetic levitation molecular pump can be simplified as follows: Figure 2 The structure shown can be approximated as a ring-shaped columnar structure.

[0033] As the temperature rises, the centroid shifts due to the linear changes in the material, meaning that the imbalance gradually increases with rising temperature.

[0034] The imbalance quantity r at temperature T 1-T It can be represented as: r 1-T =r 1-T0 +r 1-T0 ·α·(T-T0); Where T0 represents room temperature, α represents the coefficient of linear expansion of the material, and r 1-T0 This represents the imbalance quantity measured at room temperature.

[0035] The above formula can be transformed into: (r) 1-T -r 1-T0 ) / (T-T0)=r 1-T0 ·α.

[0036] The vibration value δ is directly proportional to the unbalance amount r1 (within the test range below 100°C, the effects of equivalent mass, rotational speed, rotor stiffness, etc., on the vibration value remain unchanged, so only the effect of the unbalance amount r1 needs to be considered), therefore: (δ) T -δ T0 ) / (T-T0)=δ T0 ·α; δ T δ T0 These represent the vibration values ​​at temperature T and room temperature T0, respectively.

[0037] For magnetically levitated molecular pumps of the same type, α can be considered the same.

[0038] <Example 1> Based on the understanding from theoretical analysis one, the technical solution of the embodiment is as follows: A method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, which is used to detect the vibration value of the turbine at any temperature T, includes the following steps: S100, Obtain the vibration value δ of the magnetic levitation molecular pump under test at T0. T0 It can be obtained using existing technologies such as CN119063986A; S200, obtain the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test. Q records the vibration values ​​of n molecular pumps of the same model at different temperatures. Obtain the vibration values ​​of n molecular pumps at temperatures T0 and T from dataset Q. Let the vibration value of any i-th molecular pump at temperatures T0 and T be denoted as δ. T-i δ T0-i ; S300, Solve for the vibration value δ of the magnetically levitated molecular pump under test at temperature T. T : .

[0039] <Theoretical Analysis II> From theoretical analysis one, we can obtain: δ T =δ T0 +δ T0 ·α·(T-T0).

[0040] The above equation can be further transformed into: δ T =δ T0 ·α·T+(δ T0 -δT0 ·α·T0).

[0041] In other words, there is a linear relationship between vibration value and temperature, which allows us to make full use of the information in the dataset. Figure 3 Typical temperature-vibration relationship curves for the CXF320 / 3001CV magnetic levitation molecular pump are presented, showing a linear relationship.

[0042] <Example 2> A method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, which is used to detect the vibration value of the turbine at any temperature T, includes the following steps: S100, Obtain the vibration value δ of the magnetic levitation molecular pump under test at T0. T0 ; S200, obtain the temperature vibration value dataset Q of the same model of the magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; Q = {q1, q2, ..., q...} i ……q n}; where q i This is a subset of the temperature-vibration values ​​of the i-th molecular pump in dataset Q, which records the temperature-vibration values ​​at temperature T. i-1 T i-2 ...T i-m The corresponding vibration value δ Ti-1 δ Ti-2 ……δ Ti-m ; S300, solve for the change in vibration value k1~k caused by unit temperature of n molecular pumps. n ; For any i-th molecular pump, the change in vibration value k caused by unit temperature i In other words, its acquisition method is: using (T) i-1 δ Ti-1 (T) i-2 δ Ti-2 )……(T) i-m δ Ti-m The data points are used for linear fitting, and the slope is k. i ; S400, obtain the vibration values ​​δ of n molecular pumps at temperature T0 from the Q dataset. T0-i ; S500, calculate the vibration value δ of the magnetically levitated molecular pump under test at temperature T. T : .

[0043] The physical symbols used in this application are as follows: r1: Unbalance (i.e., mass eccentricity).

[0044] δ: Radial displacement vibration value of the rotor.

[0045] r 1-T0 r 1-T : The unbalance quantity corresponding to turbine temperatures T0 and T.

[0046] T0: Room temperature, 20°C~30°C.

[0047] α: Coefficient of linear expansion of the material.

[0048] δ T0 δ T : Vibration values ​​corresponding to turbine temperatures at T0 and T.

[0049] Q: Data set of temperature vibration values ​​for the same model of magnetic levitation molecular pump under test; n: The number of molecular pumps of the same model recorded in dataset Q; δ T-i δ T0-i : The vibrational values ​​of the i-th molecular pump in dataset Q at T and T0; q1~q n : A subset of temperature-vibration values ​​for the 1st to nth molecular pumps in dataset Q; q i : A subset of temperature-vibration values ​​of the i-th molecular pump in dataset Q, where i is any natural number from 1 to n; T i-1 ~T i-m : The temperature sequence in the i-th molecular pump, where m is the number of such temperature sequences; δ Ti-1 ~δ Ti-m : The vibrational value sequence in the i-th molecular pump, which is related to T i-1 ~T i-m correspond.

[0050] k1~k n : The change in vibrational value per unit temperature of the 1st to nth molecular pumps in dataset Q; For any i-th molecular pump, the change in vibration value k caused by unit temperature i In other words, its acquisition method is: using (T) i-1 δ Ti-1 (T) i-2 δ Ti-2 )……(T) i-m δ Ti-m The data points are used for linear fitting, and the slope is k. i .

[0051] By adopting the schemes of Embodiment 1 and Embodiment 2, the operating state of the molecular pump turbine at high temperature can be calculated at low temperature. It is not necessary to confirm the dynamic balance of the molecular pump at high temperature. It is only necessary to detect the dynamic balance of the molecular pump at room temperature to ensure the vibration value of the molecular pump turbine at high temperature.

[0052] It should be noted that the temperatures of the n molecular pumps in dataset Q are generally in the range of 20°C to 100°C (within this range, δ and T can maintain a linear relationship; in semiconductor etching equipment, the temperature of the turbine of the molecular pump under normal operating conditions is also within the above temperature range).

[0053] It should be noted that the vibration values ​​described in this application are all test results of the molecular pump at the same rated speed.

[0054] The above-described embodiments are preferred embodiments of this application and are only used to facilitate the illustration of this application. They are not intended to limit this application in any way. Any person with ordinary knowledge in the art can make equivalent embodiments by making partial modifications or alterations to the technical content disclosed in this application without departing from the scope of the technical features of this application. Such equivalent embodiments are still within the scope of the technical features of this application.

Claims

1. A method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, characterized in that, Includes the following steps: S100, acquiring a vibration value δ of the magnetic levitation molecular pump to be tested at room temperature T0 T0 ; S200, obtain the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test. Q records the vibration values ​​of n molecular pumps of the same model at different temperatures. Obtain the vibration values of the n molecular pumps at T0 and T temperatures from the data set Q, and let the vibration values of an arbitrary i-th molecular pump at T0 and T temperatures be δ T0-i , δ T-i , respectively. S300, solve the vibration value δ of the magnetic levitation molecular pump to be tested at temperature T T : 。 2. A method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, characterized in that, Includes the following steps: S100, acquiring a vibration value δ of the magnetic levitation molecular pump to be tested at room temperature T0 T0 ; S200, obtain the temperature vibration value dataset Q of the same model of the magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; Q = {q1, q2, ..., q...} i ……q n }; where q i This is a subset of the temperature-vibration values ​​of the i-th molecular pump in dataset Q, which records the temperature-vibration values ​​at temperature T. i-1 T i-2 ...T i-m The corresponding vibration value δ Ti-1 δ Ti-2 ……δ Ti-m ; S300, solve for the change in vibration value k1~k caused by unit temperature of n molecular pumps. n ; For any i-th molecular pump, the change in vibration value k caused by unit temperature i In other words, its acquisition method is: using (T) i-1 δ Ti-1 (T) i-2 δ Ti-2 )……(T) i-m δ Ti-m The data points are used for linear fitting, and the slope is k. i ; S400, obtain the vibration values ​​δ of n molecular pumps at temperature T0 from the Q dataset. T0-i ; S500, calculate the vibration value δ of the magnetically levitated molecular pump under test at temperature T. T : 。 3. The method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature as described in claim 1 or 2, characterized in that, The range of T0 is [20°C, 30°C].

4. The method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature as described in claim 1 or 2, characterized in that, T is greater than T0 and less than or equal to 100°C.

5. The method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature as described in claim 2, characterized in that, T 1-1 =T 2-1 =……=T n-1 And T 1-1 The range is [20°C, 30°C].

6. The method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature as described in claim 2, characterized in that, T 1-m =T 2-m =……=T n-m 。 7. A system for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, characterized in that, include: First storage unit, second storage unit, high-temperature vibration value calculation unit; The first storage unit is used to store the vibration value δ of the magnetically levitated molecular pump under test at room temperature T0. T0 ; The second storage unit is used to store the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; The high-temperature vibration value solving unit is used to solve the vibration value δ of the magnetic levitation molecular pump under test at temperature T. T The solution method is as follows: ； δ T0-i δ T-i Let T and T represent the vibration values ​​of any i-th molecular pump in the dataset Q at temperatures T0 and T, respectively.

8. A system for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature, characterized in that, include: First storage unit, second storage unit, high-temperature vibration value calculation unit; The first storage unit is used to store the vibration value δ of the magnetically levitated molecular pump under test at room temperature T0. T0 ; The second storage unit is used to store the temperature vibration value dataset Q of the same model of magnetic levitation molecular pump under test; Q records the vibration values ​​of n molecular pumps of the same model at different temperatures; Q = {q1, q2, ..., q...} i ……q n }; where q i This is a subset of the temperature-vibration values ​​of the i-th molecular pump in dataset Q, which records the temperature-vibration values ​​at temperature T. i-1 T i-2 ...T i-m The corresponding vibration value δ Ti-1 δ Ti-2 ……δ Ti-m ; The high-temperature vibration value solving unit is used to solve the vibration value δ of the magnetic levitation molecular pump under test at temperature T. T The solution method is as follows: ； δ T0-i k i Let represent the vibration value of any i-th molecular pump among the n molecular pumps in dataset Q at time T0, and the change in vibration value caused by a unit temperature, respectively. k i The method of obtaining it is: using (T) i-1 δ Ti-1 (T) i-2 δ Ti-2 )……(T) i-m δ Ti-m The data points are used for linear fitting, and the slope is k. i .

9. An application of a method for detecting the vibration value of a magnetically levitated molecular pump turbine at high temperature as described in any one of claims 1 to 6, characterized in that, The vibration value δ of the turbine at 100°C was detected using the aforementioned detection method. 100 It is used to determine whether the vibration value of a magnetically levitated molecular pump under normal high-temperature operating conditions meets the high-temperature radial vibration requirements: If δ 100 Vibration threshold [δ] corresponding to temperatures below 100°C 阈值 If the high-temperature radial vibration requirement is met, then the high-temperature radial vibration requirement is not met.

10. The application as described in claim 9, characterized in that, Vibration threshold value [δ] corresponding to 100°C 阈值 It is 0.05μm.

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