CRYOPUMP, CRYOPUMP CONTROL SYSTEM AND CRYOPUMP CONTROL METHOD

Abstract

This application discloses a cryopump, including a pump housing, a radiation shield in the pump housing, a first-stage cold storage component in the pump housing, a second-stage cold storage component in the holding space of the radiation shield, a connector connecting the first-stage cold storage component and the radiation shield, and a cryopanel assembly in the holding space and connected to the second-stage cold storage component.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of international application of PCT application serial no. PCT/CN2023/071418, filed on Jan. 9, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

This application relates to the technical field of cryopump, in particular to, a cryopump, a cryopump control system and a cryopump control method.

Description of Related Art

Based on the principle of low temperature condensation and low temperature adsorption, cryopump captures the gas in the confined space to create a vacuum environment. It is widely used in semiconductor physical vapor deposition (PVD) and ion implantation processes due to its outstanding advantages such as high ultimate vacuum, high pumping speed, and truly clean and oil-free. In related technologies, the refrigeration component of the cryopump is generally a two-stage GM refrigerator. Due to the limited space in the pump housing, the structural design of the radiation shield, the first-stage cold storage component and the second-stage cold storage component is unreasonable, it results in a strong degree of thermal coupling between the first-stage cold storage component and the second-stage cold storage component, and the cold storage capacity is limited, which cannot meet the demand for large cooling capacity.

SUMMARY

The application aims to solve at least one of the technical problems existing in the existing technology. To this end, one purpose of the application is to propose a cryopump, which can solve the problem that the structure design of the radiation shield, the first-stage cold storage component and the second-stage cold storage component is unreasonable, the cold storage capacity is limited, and the large cold demand cannot be met.

A cryopump in this application includes:

• • a pump housing;
  • a radiation shield, arranged in the pump housing, and configured that a holding space is formed inside the radiation shield, a first through hole is arranged on the radiation shield, and the first through hole is connected with the holding space;
  • a first-stage cold storage component, arranged in the pump housing;
  • a second-stage cold storage component, arranged in the holding space, and configured that one end of the second-stage cold storage component extends from the through hole and connects the first-stage cold storage component;
  • a connector, configured that one end of the connector is connected with the first-stage cold storage component, and the other end is connected with the radiation shield; and
  • a cryopanel assembly, set in the holding space and connected to the second-stage cold storage component.

Wherein, the connector includes:

• • a first tube body, configured that the second-stage cold storage component penetrates the first tube body;
  • a first end plate, arranged at one end of the first tube body and is connected with the first-stage cold storage component; and
  • a second end plate, arranged at the other end of the first tube body and connected to the radiation shield.

Wherein, the second-stage cold storage component is coaxially arranged with the first through hole, and the diameter of the second-stage cold storage component is smaller than the diameter of the first through hole.

• • wherein, the connector also includes a second tube body and a annular barrier, the inner diameter of the first tube body is equal to the diameter of the first through hole, the second tube body is slidable in the first tube body, the annular barrier is slidable in the second tube body, and a gap is reserved between the inner wall of the annular barrier and the outer wall of the second-stage cold storage component.
  • wherein, the first-stage cold storage component has a first cooling stage connecting the first end plate, and in the axial direction of the first tube body, the projection of the first end plate is greater than or equal to the projection of the first cooling stage, the projection of the first end plate coincides with the projection of the second end plate.
  • wherein, the connector also includes a screw, the screw is rotated and installed on the first cooling stage, the screw is arranged axially in parallel with the first tube body, the annular barrier is provided with a threaded hole adapted to the screw, and the screw penetrates the annular barrier by adapting the threaded hole.
  • wherein, the connector also includes a guide rod fixed on the first cooling stage, and the guide rod and the screw are arranged in parallel axially; the annular barrier is provided with a second through hole, and the guide rod slides through the annular barrier through the second through hole.
  • wherein, the screw and the guide rod are equal in length and are partially extended into the holding space a.
  • wherein, the second tube body includes a tube body part slidable in the first tube body and a blocking part extending from the tube body part; the blocking part is located in the tube body part and away from the side of the first cooling stage, and the annular barrier is between the blocking part and the first cooling stage.
  • wherein, the first-stage cold storage component has a first cooling stage connecting the first end plate, and in the axial direction of the first tube body, the projection of the first end plate is greater than or equal to the projection of the first cooling stage, the projection of the first end plate coincides with the projection of the second end plate.
  • wherein, the cryopump also includes:
  • a first pressure detector, arranged on the pump housing to detect the pressure in the pump housing; and
  • a pressure relief valve, arranged on the pump housing, the pressure relief valve has a valve spool, and the valve spool is configured to open actively; when the first pressure detector detects that the pressure in the pump housing reaches the first set value, the valve spool is opened and maintains the set opening.

A cryopump control system, including:

• • the cryopump according to claim, the cryopump also includes a motor for powering the first-stage cold storage component and the second-stage cold storage component;
  • a compressor, which has a low-pressure pipeline and a high-pressure pipeline, the low-pressure pipeline and the high-pressure pipeline are used to provide working gas for the first-stage cold storage component and the second-stage cold storage component;
  • a second pressure detector, used for communicating the compressor and detecting the pressure of the low-pressure pipeline;
  • a third pressure detector, used for communicating the compressor and detecting the pressure of the high-pressure pipeline; and
  • a control device, used for communicating the motor and the compressor, and issuing warning information and/or remedial information according to the pressure value or pressure difference between the low-pressure pipeline and the high-pressure pipeline.
  • wherein, also including:
  • a cryopump controller, communicated with the motor and the control device, the cryopump controller can obtain the operating state parameters of the motor, and the control device evaluates the operating conditions of the cryopump and the compressor according to the operating state parameters of the motor and gives maintenance suggestions.
  • wherein, the operating state parameters of the motor include current, the cryopump controller obtains the current of the motor, the control device compares the current with the set current, and adjusts the speed of the motor through PID control algorithm.

A cryopump control method applied to the cryopump according to claim, wherein, including the following steps:

• • providing power to the first-stage cold storage component and the second-stage cold storage component;
  • using the low-pressure pipeline and high-pressure pipeline of the compressor to provide working gas for the first-stage cold storage component and the second-stage cold storage component;
  • obtaining the pressure of the low-pressure pipeline of the compressor;
  • obtaining the pressure of the high-pressure pipeline of the compressor; and
  • issuing the warning information and/or remedial information according to the pressure value or pressure difference between the low-pressure pipeline and the high-pressure pipeline.
  • wherein, also including:
  • obtaining the operating state parameters of the motor, evaluating the operating conditions of the cryopump and the compressor according to the operating state parameters of the motor, and giving maintenance suggestions.
  • wherein, the operating state parameters of the motor include current, the control method also including:
  • obtaining the current of the motor, comparing the current with the set current, and adjusting the speed of the motor through PID control algorithm.

The additional aspects and advantages of the application will be partially given in the following description, some of which will become obvious from the following description, or learned through the practice of the application.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the present application will become apparent and easy to understand from the description of embodiments combined with the illustrations below. Wherein:

FIG. 1 is a schematic diagram of the structure of a cryopump of an embodiment in this application.

FIG. 2 is a schematic diagram of the connection of the first-stage cold storage component, the second-stage cold storage component and the connector of an embodiment in this application.

FIG. 3 is a schematic diagram of the structure of a connector of an embodiment in this application.

FIG. 4 is a schematic diagram of the structure of a cryopump control system of an embodiment in this application.

FIG. 5 is the local enlarged section view of a region in FIG. 1.

FIG. 6 is a flow chart of a control method of an embodiment in this application.

FIG. 7 is a logic diagram of a control method of an embodiment in this application.

FIG. 8 is another flow chart of a control method of an embodiment in this application.

LABELS IN DRAWINGS

• • 100 cryopump control system;
  • 10 cryopump
  • 101 pump housing; 101a opening;
  • 102 radiation shield; 102a holding space;
  • 103 first-stage cold storage component; 1031 first cooling stage; 1032 first-stage cylinder; 1033 first-stage piston;
  • 104 second-stage cold storage component; 1041 second cooling stage; 1042 second-stage cylinder; 1043 second-stage piston;
  • 105 connector; 1051 first tube body; 10511 first through hole; 1052 first end plate; 1053 second end plate; 1054 second tube body; 1055 annular barrier; 1056 screw; 1057 guide rod; 10541 tube body part; 10542 blocking part; 105421 second through hole; 106 cryopanel assembly; 107 first pressure detector; 108 pressure relief valve; 1081 valve spool; 109 motor; 110 baffle; 111 second temperature detector; 112 bleed valve; 113 nitrogen purging valve; 114 first temperature detector;
  • 201 host; 202 communication controller; 203 Local operation panel;
  • 30 compressor; 301 low-pressure pipeline; 3011 second pressure detector; 302 high-pressure pipeline; 3021 third pressure detector; 40 cryopump controller; 50 control device.

DESCRIPTION OF THE EMBODIMENTS

The embodiment of the application is described in detail below, and an example of the embodiment is shown in the accompanying figures, wherein identical or similar labels from beginning to end represent identical or similar components or components with the same or similar functions. The following embodiments described by reference to the accompanying figures are illustrative and are only used to explain the application, and cannot be understood as a limitation of the application.

In the description of the present application, it is necessary to understand. The terms ‘center’, ‘longitudinal’, ‘transverse’, ‘length’, ‘width’, ‘thickness’, ‘up’, ‘down’, ‘front’, ‘back’, ‘left’, ‘right’, ‘vertical’, ‘horizontal’, ‘top’, ‘bottom’, ‘inside’, ‘outside’, ‘clockwise’, ‘counterclockwise’, ‘axial’, ‘radial’, ‘circumferential’ and so on indicate the orientation or positional relationship based on the orientation or positional relationship shown in the attached diagram. It is only for the convenience of describing the invention and simplifying the description, rather than indicating or suggesting that the device or component must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a restriction on the application.

In addition, the features that are limited to ‘first’ and ‘second’ can explicitly or implicitly include one or more of these features, which are used to distinguish the description features, without order and weight.

In the description of the application, unless otherwise stated, the meaning of ‘multiple’ is two or more.

In the description of the application, it should be noted that, unless otherwise specified and limited, the terms ‘installation’, ‘connection’, ‘connection’ should be understood in a broad sense, for example, it can be fixed connection, detachable connection, or integrated connection; it can be mechanical connection or electrical connection; it can be directly connected or indirectly connected through an intermediate medium, which can be the internal connection of two components. For ordinary technicians in this field, the specific meaning of the above terms in this application can be understood in detail.

The following refers to FIG. 1-FIG. 3 to describe the cryopump according to the embodiment of the application.

As shown in FIG. 1, the cryopump according to the embodiment of the application, includes: a pump housing 101, a radiation shield 102, a first-stage cold storage component 103, a second-stage cold storage component 104, a connector 105 and a cryopanel assembly 106.

The radiation shield 102 is arranged in the pump housing 101, and configured that a holding space 102a is formed inside the radiation shield 102, a first through hole 10511 is arranged on the radiation shield 102, and the first through hole 10511 is connected with the holding space 102a. The first-stage cold storage component 103 is arranged in the pump housing 101. The second-stage cold storage component 104 is arranged in the holding space 102a, and configured that one end of the second-stage cold storage component 104 extends from the through hole and connects the first-stage cold storage component 103. The connector 105 is configured that one end of the connector 105 is connected with the first-stage cold storage component 103, and the other end is connected with the radiation shield 102. The cryopanel assembly 106 is set in the holding space 102a and connected to the second-stage cold storage component 104.

It can be understood that the holding space 101 has an opening 101a. In related technologies, when the radiation shield is located in the holding space, it is necessary to ensure that the radiation shield and the opening 101a are concentric. While the internal space of the holding space is limited, so that the sum of the length of the first-stage cold storage component and the second-stage cold storage component is determined. The first-stage cold storage component 103 of the cryopump of the application is connected to the radiation shield 102 through the connector 105, and one end of the second-stage cold storage component 104 extends the first through hole 10511 and is connected to the first-stage cold storage component 103. In this way, the length of the first-stage cold storage component 103 can be reduced and the length of the second-stage cold storage component 104 can be increased.

As shown in FIG. 2, the first-stage cold storage component 103 includes a first-stage cylinder 1032, a first-stage piston 1033, and a first cooling stage 1031. The second-stage cold storage component 104 includes the second-stage cylinder 1042, the second-stage piston 1043 and the second cooling stage 1041. The composition and operation of the first-stage cold storage component 103 and the second-stage cold storage component 104 are known to ordinary technicians in this field, and are no longer described in detail here. As shown in FIG. 2, the distance from the first-stage cylinder 1032 to the radiation shield 102 is L1, the length of the connector 105 is ΔL, and the distance from the second cooling stage 1041 to the radiation shield 102 is L2. Then the length of the first-stage piston 1033 is L1−ΔL, and the length of the second-stage piston 1043 is L2+ΔL. It can be seen that, when the total length of the first-stage cold storage component 103 and the second-stage cold storage component 104 remains unchanged, the length of the second-stage cold storage component 104 increases, and the length of the first-stage cold storage component 103 decreases. Therefore, the heat conduction from the first-stage cold storage component 103 (temperature of 65-100K) at higher temperature to the second-stage cold storage component 104 at lower temperature is reduced (for example, the temperature energy of the second-stage cold storage component 104 is reduced from 14-18K before improvement to 8-15K), thereby weakening the effect of the first-stage temperature control on the conduction heat load of the second-stage temperature control, which is conducive to maintaining the second-stage cold storage unit 1041 at a lower temperature.

On the other hand, due to the increase of the length of the second-stage piston 1043, it is possible to allow the second-stage piston 1043 to be filled with more cold storage materials, improve the cold storage capacity of the second-stage piston 1043, and meet the large gas load during the working process of the cryopump.

It should be noted that, ‘hot connection’ between the connector 105 and the radiation shield 102 and between the connector 105 and the first-level cold storage component 103, can mean that the two objects are in good contact and can transfer heat efficiently between each other. The other components and operation of the cryopump of the embodiment of the application are known to the ordinary technical personnel in this field, and are not repeated here.

According to the cryopump of the embodiment of the application, the cryopump can increase the length of the second-stage cold storage component 104 and reduce the length of the first-stage cold storage component 103, improve the energy storage capacity of the second-stage cold storage component 104, and meet the demand of large cooling capacity.

In some embodiments of the present application, as shown in FIG. 2 and FIG. 3, the connector 105 includes a first tube body 1051, a first end plate 1052 and a second end plate 1053. The second-stage cold storage component 104 penetrates the first tube body 1051. The first end plate 1052 is arranged at one end of the first tube body 1051 and is connected to the first-stage cold storage component 103. The second end plate 1053 is arranged at the other end of the first tube body 1051 and connected to the radiation shield 102. The internal hollow of the first tube body 1051 can play a role in avoiding the second-stage cold storage component 104. The first end plate 1052 and the first cooling stage 1031 have a large contact surface, and the second end plate 1053 and the radiation shield 102 have a large contact surface, which can improve the connection reliability between the connector 105 and the first-stage cold storage component 103 and the radiation shield 102.

In some embodiments of the present application, as shown in FIG. 4 and FIG. 5, the connector 105 also includes a second tube body 1054 and a annular barrier 1055, the inner diameter of the first tube body 1051 is equal to the diameter of the first through hole 10511, the second tube body 1054 is slidable in the first tube body 1051, the annular barrier 1055 is slidable in the second tube body 1054, and a gap is reserved between the inner wall of the annular barrier 1055 and the outer wall of the second-stage cold storage component 104. It makes the limit between the inner wall of the annular barrier 1055 and the outer wall of the second-stage cold storage component 104 close but not in contact. The first tube body 1051 is coaxially arranged with the first through hole 10511. The second cold storage component 104 is arranged in the first tube body 1051. The first end plate 1052 is arranged at one end of the first tube body 1051 and connected with the first cold storage component 103. The second end plate 1053 is arranged at the other end of the first tube body 1051 and connected with the radiation shield 102.

There is a large temperature difference between the first-stage cold storage component 103 and the second-stage cold storage component 104, which plays a pre-cooling role in the radiation shield 102 and the gas entering the radiation shield 102. The first-stage cold storage component 103 is directly connected to the second-stage cold storage component 104, so it is difficult to avoid the influence of the first-stage cold storage component 103 on the second-stage cold storage component 104. Due to the limit between the inner wall of the annular blocker 1055 and the outer wall of the secondary cold storage component 104 is close but not in contact, the inner wall of the annular barrier 1055 will not have thermal contact with the outer wall of the second-stage cold storage component 104, and it can prevent the gas in the holding space 102a from reaching the side of the annular barrier 1055 near the first-stage cold storage component 103, within 102 a, where the high temperature is not conducive to gas condensation (on the right side in FIG. 5). Since the annular barrier 1055 can slide in the second-stage cold storage component 104, the position of the annular barrier 1055 can be randomly adjusted according to the temperature difference between the first-stage cold storage component 103 and the second-stage cold storage component 104, so as to minimize the adverse effect on gas condensation.

In addition, the temperature of the second-stage cold storage component 104 gradually increases from left to right, and the temperature range of the second-stage cold storage component 104 is (m K-n K). After some types of gases (such as nitrogen) enter the holding space 102 a, an intermediate state (gas-liquid mixing or liquid-solid mixing) will be formed at a specific temperature point or temperature range (such as near the melting point or boiling point of nitrogen) in (m K-n K), which will seriously affect the stability and persistence of gas sublimation. The second tube body 1054 can slide in the first tube body 1051, and the annular barrier 1055 can slide in the second tube body 1054. This can make the second tube body 1054 adjust to the direction away from the first-stage cold storage component 103 in the first tube body 1051, and even make the second tube body 1054 part enter the holding space 102a. The annular barrier 1055 sliding in the second tube body 1054 can also enter the holding space 102a and stay on the second-stage cold storage component 104, where the gas will be caused to form an intermediate state. Or the annular barrier 1055 can also enter the position further away from the first-stage cold storage component 103. The position on the second tube body 1054 that can make the gas form an intermediate state is blocked between the annular barrier 1055 and the first-stage cold storage component 103 and makes the gas difficult to enter, thereby maintaining the continuity of the gas condensation.

In some embodiments of the present application, the connector 105 also includes a screw 1056. The screw 1056 is rotated and installed on the first cooling stage 1031. The screw 1056 is arranged axially in parallel with the first tube body 1051, the annular barrier 1055 is provided with a threaded hole adapted to the screw 1056, and the screw 1056 penetrates the annular barrier 1055 by adapting the threaded hole. Through the rotation of the screw 1056, the position adjustment of the annular barrier 1055 can be realized.

In some embodiments of the present application, the connector 105 also includes a guide rod 1057 fixed on the first cooling stage 1031, and the guide rod 1057 and the screw 1056 are arranged in parallel axially. The annular barrier 1055 is provided with a second through hole 105421, and the guide rod 1057 slides through the annular barrier 1055 through the second through hole 105421.

In some embodiments of the present application, the screw 1056 and the guide rod 1057 are equal in length and are partially extended into the holding space 102a.

In some embodiments of the present application, the second tube body 1054 includes a tube body part 10541 slidable in the first tube body 1051 and a blocking part 10542 extending from the tube body part 10541. The blocking part 10542 is located in the tube body part 10541 and away from the side of the first cooling stage 1031, and the annular barrier 1055 is between the blocking part 10542 and the first cooling stage 1031. When the screw 1056 drives the annular barrier 1055 to move away from the first-stage cold storage component 103, the second tube body 1054 can be pushed into the holding space 102a through the blocking part 10542.

In some embodiments of the present application, as shown in FIG. 3, the first end plate 1052 is an annular plate set around the rim of the first tube body 1051, which can make any position of the rim of the first tube body 1051 connect with the first-stage cold storage component 103, and further improve the connection reliability between the connection 105 and the first-stage cold storage component 103.

In some embodiments of the present application, as shown in FIG. 3, the second endplate 1053 is an annular plate set around the rim of the first tube body 1051, which can make any position of the rim of the first tube body 1051 connect with the radiation shield 102, and further improve the connection reliability between the connection 105 and the radiation shield.

In some embodiments of the present application, the first end plate 1052 and the second end plate 1053 are circular or rectangular.

In some embodiments of the present application, the inner diameter of the first tube body 1051 is larger than the outer diameter of the second-stage cold storage component 104.

In some embodiments of the present application, as shown in FIG. 2, the first-stage cold storage component 103 has a first cooling stage 1031 connecting the first end plate 1052, and in the axial direction of the first tube body 1051, the projection of the first end plate 1052 is greater than or equal to the projection of the first cooling stage 1031, the projection of the first end plate 1052 coincides with the projection of the second end plate 1053. That is to say, the surface area of the first end plate 1052 connected with the first cooling stage 1031 is larger than that of the first cooling stage 1031. Or, the surface area of the first end plate 1052 connected to the first cooling stage 1031 is equal to the surface area of the first cooling stage 1031. This ensures that the connection between the first end plate 1052 and the first-stage cold stand 1031 is reliable. The second end plate 1053 can be the same as the shape and size of the first end plate 1052, which can simplify the manufacturing process of the connector 105 and reduce the manufacturing difficulty.

For example, the first end plate 1052 and the second end plate 1053 can be circular rings with equal shape and size.

In some embodiments of the present application, as shown in FIG. 1, the cryopump also includes a first pressure detector 107 and a pressure relief valve 108. The first pressure detector 107 is arranged on the pump housing 101 to detect the pressure in the pump housing 101. The pressure relief valve 108 is arranged on the pump housing 101. The pressure relief valve 108 has a valve spool 1081, and the valve spool 1081 is configured to open actively. When the first pressure detector 107 detects that the pressure in the pump housing 101 reaches the first set value, the valve spool 1081 is opened and maintains the set opening.

As shown in FIG. 1, after the gas capacity in the cryopump is saturated, high-purity dry nitrogen is generally introduced through a nitrogen purging valve 113, and combined with the motor 109 reverse and/or the heater placed in the first cooling stage 1031 or the second cooling stage 1041 or external heater to complete the heating of the cryopanel assembly 106, the radiation shield 102 and the baffle 110. During the heating process, a large amount of gas will be desorbed from the cryopanel assembly 106, and the gas will be discharged from the pressure relief valve 108 after desorption. In the related technology, the pressure relief valve is designed to be opened passively. When the gas pressure in the cryopump reaches the target pressure, the pressure relief valve is opened, which leads to a large gas flow resistance in the pipeline during the regeneration process, the heat transfer effect relatively poor, and the regeneration time relatively long. In the process, as the gas is discharged, the opening of the valve core 1081 is unstable and cannot be maintained.

The pressure relief valve 108 of the application has an active opening function. When the first pressure detector 107 detects that the pressure in the pump housing 101 reaches the first set value, the valve spool 1081 is opened and maintains the set opening. Since the pressure relief valve 108 is actively opened, a larger valve spool 1081 opening can be selected to reduce the flow resistance of the pipeline gas during the regeneration process, increase the heat transfer effect, and reduce the regeneration heating time. On the other hand, the pressure relief valve 108 of the application can ensure that the opening of the valve spool 1081 is relatively stable. That is to say, the pressure relief valve 108 has been working in a stable state, to avoid seal ring fluctuation of the pressure relief valve 108 and even resonance phenomenon caused by the instantaneous gasification of gas condensate during passive pressure relief, which is beneficial to improve the service life of the pressure relief valve 108.

For example, in the passive pressure relief valve in the opening process in the related technology, because its opening process depends on the gas pressure, when the gas pressure reaches the target pressure, the valve spool 1081 opening is maintained at 0.5-2 mm. After the pressure relief valve 108 of the application is actively opened, the opening of the valve spool 1081 can be maintained at 5-10 mm, which has a larger opening, so it can reduce the gas flow resistance of the pipeline.

Specifically, the above ‘first set value’ can be set according to the situation. For example, the first set value can be the atmospheric pressure value.

In some embodiments of the present application, the first pressure detector 107 can be a vacuum gauge, a pressure detector or other instrument or component that can detect pressure, which is no longer described here.

In some embodiments, as shown in FIG. 1, the cryopump also includes the first temperature detector 114 and the second temperature detector 111. The first temperature detector 114 is set on the first-stage cold storage part 103 to detect the temperature of the first-stage cold storage part 103, and the second temperature detector 111 is set on the second-stage cold storage part 104 to detect the temperature of the second-stage cold storage part 104.

Specifically, the first temperature detector 114 is set on the first cooling stage 1031, and the second temperature detector 111 is set on the second cooling stage 1041. Optionally, the first temperature detector 114 and the second temperature detector 111 are temperature sensors or other temperature detection components.

In some embodiments of the present application, as shown in FIG. 1, the cryopump includes a bleed valve 112, which is arranged on the pump housing 101 to extract the gas in the pump housing 101. The bleed valve 112 can quickly discharge the gas in the pump housing 101 and play a rough pumping role.

As shown in FIG. 4, the cryopump control system according this application includes a cryopump, a compressor 30, a second pressure detector 3011, a third pressure detector 3021, and a control device 50.

The cryopump also includes a motor 109 for powering the first-stage cold storage component 103 and the second-stage cold storage component 104. The compressor 30 has a low-pressure pipeline 301 and a high-pressure pipeline 302, the low-pressure pipeline 301 and the high-pressure pipeline 302 are used to provide working gas for the first-stage cold storage component 103 and the second-stage cold storage component 104. The second pressure detector 3011 is used for communicating the compressor 30 and detecting the pressure of the low-pressure pipeline 301.

The third pressure detector 3021 is used for communicating the compressor 30 and detecting the pressure of the high-pressure pipeline 302. The control device 50 is used for communicating the motor 109 and the compressor 30, and issuing warning information and/or remedial information according to the pressure value or pressure difference between the low-pressure pipeline 301 and the high-pressure pipeline 302.

It can be understood that the mechanical system structure of the cryopump in the related technology is more complicated, and there are many sealing connection structures. It is difficult to detect the leakage in time during operation. The low-pressure pipeline 301 and high-pressure pipeline 302 of the application are used to provide helium to the cryopump. The pressure of the low-pressure pipeline 301 is detected in real time by the second pressure detector 3011, and the pressure of the high-pressure pipeline 302 is detected in real time by the third pressure detector 3021. After obtaining the detected pressure value or pressure difference, the control device 50 can give warning information and/or remedial information, detect the leakage in time and remedy it.

For example, when the control system is working, the compressor 30 after power-on may be in both non-operation and operation states.

When the compressor 30 is not in operation, the pressure of low-pressure pipeline 301 and high-pressure pipeline 302 should be kept equal. When the pressure of the low-pressure pipeline 301 and the pressure of the high-pressure pipeline 302 are less than the first target threshold, the control device 50 issues warning information and/or remedial information. When the compressor 30 is in operation, the pressure of the high-pressure pipeline 302 should be greater than that of low-pressure pipeline 301. In order to maintain a stable refrigerant supply at the cryopump, the pressure difference between the high-pressure pipeline 302 and the low-pressure pipeline 301 needs to be maintained at a constant value. When the pressure difference between the high-pressure line 302 and the low-pressure line 301 is less than the second target threshold, the control device 50 issues a warning message and/or a remedial message.

The ‘warning information’ can be an alarm. ‘Remedial information’ can be prompted to the operator for system leak detection or refrigerant supplement. The ‘first target threshold’ and ‘second target threshold’ can be set as needed, which is not repeated here.

It should be noted that the compressor 30 includes mechanical structure such as press pump and electrical control department. The communication of the electrical control department connects the second pressure detector 3011 and the third pressure detector 3021. In the embodiment of the invention, the other components and operations of the compressor 30 are known to the ordinary technicians in this field, and are no longer described in detail here.

As shown in FIG. 4, the control device 50 includes a host 201, a communication controller 202 and a local operation panel 203. The communication controller 202 is connected with the host 201 and the local operation panel 203, and is connected with the compressor 30. The host 201 can be a computer to perform computing and control functions. The local operation panel 203 has a display screen, warning information and remedial information can be displayed on the display screen.

In the cryopump control system according this application, by the second pressure detector 3011, the third pressure detector 3021 and the control device 50, it can detect whether the system pipeline leaks, and give warning information and remedial information.

In some embodiments of the present application, as shown in FIG. 4, the cryopump control system also includes a cryopump controller 40. The cryopump controller 40 is communicated with the motor 109 and the control device 50. The cryopump controller 40 can obtain the operating state parameters of the motor 109, and the control device 50 evaluates the operating conditions of the cryopump and the compressor 30 according to the operating state parameters of the motor 109 and gives maintenance suggestions.

The reliability of the cryopump is mainly affected by the wear of the piston ring and valve of the first-stage cold storage component 103 and the second-stage cold storage component 104 and the attenuation of the adsorption performance of the compressor 30. The industry generally adopts the method of regular replacement (usually 1˜3 years), which could not be quantitatively evaluated according to the actual working conditions, and there is a waste problem. And the failure in the replacement cycle could not be predicted in time. The application obtains the operating state parameters of the motor 109 through the cryopump controller 40, and the control device 50 can give a quantitative evaluation according to the operating state parameters of the motor 109, obtain the operating conditions of the cryopump and the compressor 30, predict in advance, and give maintenance suggestions for timely maintenance or replacement.

In some embodiments of the present application, the operating state parameters of motor 109 include speed, current and temperature. The motor 109 can be built with a speed detector and a temperature detector to detect the corresponding speed and temperature. The cryopump controller 40 obtains the speed, current and temperature of the motor 109 in real time. When the speed of motor 109 reaches the set speed value, the control device 50 evaluates the working condition of the cryopump and outputs the conclusion. When the current of the motor 109 reaches the set current, the control device 50 evaluates the working condition of the cryopump and outputs the conclusion. When the temperature of the motor 109 reaches the set temperature value, the control device 50 evaluates the working condition of the cryopump and outputs the maintenance suggestion.

The wear of the piston ring and valve of the first-stage cold storage component 103 and the second-stage cold storage component 104 and the attenuation of the adsorption performance of the compressor 30 will affect the current, speed and temperature changes of the motor 109. The working state of the system can be reflected by analyzing the current, speed and temperature of motor 109. For example, the external environment does not change but the speed of motor 109 is detected to rise, which may reflect the decrease of piston cold storage capacity or the leakage fault of piston ring. When the piston ring wears seriously to produce more powder or the purity of the refrigerant gas decreases due to the performance degradation of the compressor adsorber, the operating resistance of the corresponding piston (first-stage piston 1033 and second-stage piston 1043 will increase, resulting in an increase in the operating current value of the motor 109. It can also determine the wear of the piston ring and the valve and the attenuation of the adsorption performance of the compressor 30.

In some embodiments of the present application, the operating state parameters of the motor 109 include current, the cryopump controller 40 obtains the current of the motor 109, the control device 50 compares the current with the set current, and adjusts the speed of the motor 109 through PID control algorithm. It can be understood that the cooling process of cryopump in related technology changes with the decrease of temperature and the change of motor load. The higher the motor speed, the lower the load capacity, the more serious the heating and the longer the cooling time. In order to prevent the motor from overload operation during the working process of the cryopump, the lower constant speed is generally used to cool down, and the cooling time is relatively long. The application obtains the current of the motor 109 in real time and feeds it back to the cryopump controller 40, and compares the obtained current with the set current (the set current can refer to the current reference value corresponding to the maximum torque condition of the motor). The PID control algorithm is used to dynamically adjust the speed of motor 109, so that the motor torque is suitable during the cooling process and the cooling time of the system is shortened.

As shown in FIG. 6, the cryopump control method according to the embodiment of the present application includes:

• • S1: obtaining the pressure of the low-pressure pipeline 301 of the compressor 30;
  • S2: obtaining the pressure of the high-pressure pipeline 302 of the compressor 30; and
  • S3: issuing the warning information and/or remedial information according to the pressure value or pressure difference between the low-pressure pipeline 301 and the high-pressure pipeline 302.

In the cryopump control method according to the embodiment of the present application, through this control method, it can detect whether the system pipeline leaks, and give warning information and remedial information.

As shown in FIG. 7, in some embodiments of the present application, S3 includes:

• • determining whether the compressor 30 is in operation;
  • if so, when the pressure difference between the low-pressure pipeline 301 and the high-pressure pipeline 302 is less than the second target threshold, the low-pressure alarm is issued;

If not, when the pressure of low-pressure pipeline 301 and high-pressure pipeline 302 is less than the first target threshold, the low-pressure alarm is issued.

It can be understood that, as shown in FIG. 7, the running state of compressor 30 is first self-checked to determine whether the compressor 30 is in the running state. If the compressor 30 is not in running state, the pressure of the low-pressure pipeline 301 and the high-pressure pipeline 302 is obtained and recorded as P to determine whether the pressure P is greater than or equal to the first target threshold Pt. If so, there is no need to perform any operation. If not, the low-pressure alarm is prompted. If the compressor 30 is in running state, the pressure P1 of the low-pressure pipeline 301 and the pressure P2 of the high-pressure pipeline 302 are obtained to determine whether the P2−P1 is greater than or equal to the second target threshold ΔP0. If so, there is no need to perform any operation, otherwise the low-pressure alarm is prompted.

In some embodiments of the present application, as shown in FIG. 8, the cryopump control method also includes S4: obtaining the operating state parameters of the motor 109, evaluating the operating conditions of the cryopump 10 and the compressor 30 according to the operating state parameters of the motor 109, and giving maintenance suggestions. By obtaining the operating state parameters of motor 109, the quantitative evaluation can be given according to the operating state parameters of motor 109, the operating conditions of cryopump and compressor 30 can be obtained, the prediction can be made in advance, and the maintenance suggestions can be given to repair or replace in time.

In some embodiments of the present application, the operating state parameters of the motor 109 include current, the control method also includes S5: obtaining the current of the motor 109, comparing the current with the set current, and adjusting the speed of the motor 109 through PID control algorithm. It can be understood that, through obtaining the current of the motor 109 in real time, the obtained current is compared with the set current (the set current can refer to the current reference value corresponding to the maximum torque condition of the motor). The PID control algorithm is used to dynamically adjust the speed of motor 109, so that the motor torque is suitable during the cooling process and the cooling time of the system is shortened.

In the description of this instruction, the reference terms ‘some embodiments optionally’, ‘further’ or ‘some examples’, etc. are described to mean that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the present application. In this instruction, the indicative expression of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in an appropriate manner in any one or more embodiments or examples.

Although the embodiments of the application have been shown and described, ordinary technicians in the field can understand that these embodiments can be varied, modified, replaced and modified without deviating from the principle and purpose of the application, and the scope of the invention is limited by the claim and its equivalents.

Claims

1. A cryopump, including:

a pump housing;

a radiation shield, arranged in the pump housing, and configured that a holding space is formed inside the radiation shield, a first through hole is arranged on the radiation shield, and the first through hole is connected with the holding space;

a first-stage cold storage component, arranged in the pump housing;

a second-stage cold storage component, arranged in the holding space, and configured that one end of the second-stage cold storage component extends from the first through hole and connects the first-stage cold storage component;

a connector, configured that one end of the connector is connected with the first-stage cold storage component, and other end is connected with the radiation shield; and

a cryopanel assembly, set in the holding space and connected to the second-stage cold storage component.

2. The cryopump according to claim 1, wherein, the connector includes:

a first tube body, configured that the second-stage cold storage component penetrates the first tube body;

a first end plate, arranged at one end of the first tube body and is connected with the first-stage cold storage component; and

a second end plate, arranged at other end of the first tube body and connected to the radiation shield.

3. The cryopump according to claim 2, wherein, the second-stage cold storage component is coaxially arranged with the first through hole, and a diameter of the second-stage cold storage component is smaller than a diameter of the first through hole.

4. The cryopump according to claim 3, wherein, the connector also includes a second tube body and a annular barrier, an inner diameter of the first tube body is equal to the diameter of the first through hole, the second tube body is slidable in the first tube body, the annular barrier is slidable in the second tube body, and a gap is reserved between an inner wall of the annular barrier and an outer wall of the second-stage cold storage component.

5. The cryopump according to claim 4, wherein, the first-stage cold storage component has a first cooling stage connecting the first end plate, and in an axial direction of the first tube body, a projection of the first end plate is greater than or equal to a projection of the first cooling stage, the projection of the first end plate coincides with a projection of the second end plate.

6. The cryopump according to claim 5, wherein, the connector also includes a screw, the screw is rotated and installed on the first cooling stage, the screw is arranged axially in parallel with the first tube body, the annular barrier is provided with a threaded hole adapted to the screw, and the screw penetrates the annular barrier by adapting the threaded hole.

7. The cryopump according to claim 6, wherein, the connector also includes a guide rod fixed on the first cooling stage, and the guide rod and the screw are arranged in parallel axially; the annular barrier is provided with a second through hole, and the guide rod slides through the annular barrier through the second through hole.

8. The cryopump according to claim 7, wherein, the screw and the guide rod are equal in length and are partially extended into the holding space.

9. The cryopump according to claim 8, wherein, the second tube body includes a tube body part slidable in the first tube body and a blocking part extending from the tube body part; the blocking part is located in the tube body part and away from a side of the first cooling stage, and the annular barrier is between the blocking part and the first cooling stage.

10. The cryopump according to claim 2, wherein, the first-stage cold storage component has a first cooling stage connecting the first end plate, and in an axial direction of the first tube body, a projection of the first end plate is greater than or equal to a projection of the first cooling stage, the projection of the first end plate coincides with a projection of the second end plate.

11. The cryopump according to claim 1, wherein, the cryopump also includes:

a first pressure detector, arranged on the pump housing to detect a pressure in the pump housing; and

a pressure relief valve, arranged on the pump housing, the pressure relief valve has a valve spool, and the valve spool is configured to open actively; when the first pressure detector detects that the pressure in the pump housing reaches a first set value, the valve spool is opened and maintains a set opening.

12. A cryopump control system, including:

the cryopump according to claim 1, the cryopump also includes a motor for powering the first-stage cold storage component and the second-stage cold storage component;

a compressor, which has a low-pressure pipeline and a high-pressure pipeline, the low-pressure pipeline and the high-pressure pipeline are used to provide working gas for the first-stage cold storage component and the second-stage cold storage component;

a second pressure detector, used for communicating the compressor and detecting a pressure of the low-pressure pipeline;

a third pressure detector, used for communicating the compressor and detecting a pressure of the high-pressure pipeline; and

a control device, used for communicating the motor and the compressor, and issuing warning information and/or remedial information according to a pressure value or a pressure difference between the low-pressure pipeline and the high-pressure pipeline.

13. The cryopump control system according to claim 12, wherein, also including:

a cryopump controller, communicated with the motor and the control device, the cryopump controller can obtain operating state parameters of the motor, and the control device evaluates operating conditions of the cryopump and the compressor according to the operating state parameters of the motor and gives maintenance suggestions.

14. The cryopump control system according to claim 13, wherein, the operating state parameters of the motor include current, the cryopump controller obtains the current of the motor, the control device compares the current with a set current, and adjusts a speed of the motor through PID control algorithm.

15. A cryopump control method applied to the cryopump according to claim 1, wherein, including the following steps:

providing power to the first-stage cold storage component and the second-stage cold storage component;

using a low-pressure pipeline and a high-pressure pipeline of a compressor to provide working gas for the first-stage cold storage component and the second-stage cold storage component;

obtaining a pressure of the low-pressure pipeline of the compressor;

obtaining a pressure of the high-pressure pipeline of the compressor; and

issuing a warning information and/or a remedial information according to a pressure value or a pressure difference between the low-pressure pipeline and the high-pressure pipeline.

16. The cryopump control method according to claim 15, wherein, also including:

obtaining operating state parameters of a motor, evaluating operating conditions of the cryopump and the compressor according to the operating state parameters of the motor, and giving maintenance suggestions.

17. The cryopump control method according to claim 16, wherein, the operating state parameters of the motor include current, the cryopump control method also including:

obtaining the current of the motor, comparing the current with a set current, and adjusting a speed of the motor through PID control algorithm.