Cryopump system

Abstract

The present invention provides a cryopump system comprising a cryopump and a compressor for supplying a high-pressure helium refrigerant to the cryopump, the cryopump system comprising: a temperature measurement unit for measuring the temperature of a first stage part and a second stage part of the cryopump; a monitoring unit that monitors whether or not the temperature of the secondary stage unit reaches a preset secondary reference temperature; and a control unit that increases the operating frequency of the compressor in stages each time the temperature of the second stage unit reaches the preset second-stage reference temperature.

Description

Technical Field

[0001] The present invention relates to a cryogenic pump system. Background Art

[0002] Ultra-low temperature cooling is widely used in various industrial fields such as semiconductor manufacturing and testing. Here, ultra-low temperature can refer to temperatures below -200 degrees. The cooling process used to obtain ultra-low temperatures generally uses a compressor, a condenser, an expander, and an evaporator. The refrigerant evaporates in the evaporator to create an ultra-low temperature environment.

[0003] Regarding this technology of constructing an ultra-low temperature environment, Korean Patent Publication No. 2020-0079062, which is a prior art, discloses an ultra-low temperature refrigerator.

[0004] In order to construct an ultra-low temperature environment, the GM (Gifford-McMahon) refrigerator, which is a high-vacuum cryopump refrigerator, is mainly used. The characteristic of this cryopump refrigerator is that when the temperature of the cryopump is initially reduced from room temperature to 20K, the refrigerator operates at a motor speed of the highest rpm. After the temperature of the cryopump reaches 20K, the refrigerator operates at a motor speed of about 50 to 60 rpm. Summary of the invention

[0005] Technical issues

[0006] The present invention provides the following cryopump system: the temperature of the secondary stage of the primary stage and the secondary stage of the cryopump is measured, and whether the temperature of the secondary stage reaches a preset secondary reference temperature is monitored.

[0007] The present invention provides a cryopump system which increases the operating frequency of a compressor in stages every time the temperature of a secondary stage reaches a preset secondary reference temperature.

[0008] However, the technical problems to be solved by this embodiment are not limited to the above-mentioned technical problems, and there may be other technical problems.

[0009] Technical Solution

[0010] As a means for solving the above-mentioned technical problems, one embodiment of the present invention can provide a cryogenic pump system, including a cryogenic pump and a compressor for supplying high-pressure helium refrigerant to the above-mentioned cryogenic pump, wherein the cryogenic pump system includes: a temperature measuring unit for measuring the temperature of the above-mentioned secondary stage part among the first stage part and the second stage part of the cryogenic pump; a monitoring unit for monitoring whether the temperature of the above-mentioned secondary stage part reaches a preset secondary reference temperature; and a control unit for increasing the operating frequency of the above-mentioned compressor in stages each time the temperature of the above-mentioned secondary stage part reaches the above-mentioned preset secondary reference temperature.

[0011] According to one embodiment, the initial operating frequency of the compressor may be 40 Hz to 45 Hz, and the control unit may increase the operating frequency of the compressor to 50 Hz to 60 Hz.

[0012] According to one embodiment, each time the preset secondary reference temperature is reached, the control unit can increase the operating frequency of the compressor by 5 Hz to 10 Hz.

[0013] According to an embodiment, the preset secondary reference temperature may be greater than 17K and less than 20K.

[0014] According to an embodiment, when the compressor is operating at a frequency of 60 Hz, after exceeding the preset secondary reference temperature, the control unit can execute the regeneration process.

[0015] The above-mentioned means for solving the problems are merely illustrative and should not be construed as limiting the present invention. In addition to the above-mentioned illustrative embodiments, there may be additional embodiments described in the drawings and the detailed description of the invention.

[0016] Effects of the Invention

[0017] According to any one of the above-mentioned means for solving the problems of the present invention, the following cryopump system can be provided: the temperature of the secondary stage of the cryopump is measured, and whether the temperature of the secondary stage reaches a preset secondary reference temperature is monitored.

[0018] A cryopump system can be provided in which the operating frequency of the compressor is increased in stages each time the temperature of the secondary stage reaches a preset secondary reference temperature, thereby reducing the power of the cryopump.

[0019] The present invention can provide a cryopump system that does not set the compressor operating frequency to the maximum operating frequency from the beginning of the cooling process, but gradually increases the compressor operating frequency according to the temperature increasing with the use time or the increase in gas condensation amount, thereby reducing power.

[0020] The present invention can provide a cryopump system in which the initial operating frequency of a compressor is set low to operate the compressor, thereby reducing power. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1a FIG. 1 is an illustrative diagram showing a cryopump system according to an embodiment of the present invention.

[0022] Figure 1b This is an illustrative diagram showing a cryopump according to an embodiment of the present invention.

[0023] Figure 2aThis is an example diagram showing a table of cooling capacities and powers for a primary stage and a secondary stage according to an increase in the operating frequency of a compressor in a cryopump system according to an embodiment of the present invention.

[0024] Figure 2b This is an exemplary diagram showing the temperature and cooling capacity of the primary stage and the secondary stage for all operating frequencies of the compressor in the cryopump system according to one embodiment of the present invention.

[0025] Figure 2c This is an example diagram showing a graph of measurement results of the pumping speed of argon gas in a cryopump system according to an embodiment of the present invention.

[0026] Figure 2d This is an example diagram showing a cooling capacity graph of a primary stage and a secondary stage when the operating frequency of the compressor is increased to 40 Hz in a cryopump system according to an embodiment of the present invention.

[0027] Figure 2e This is an example diagram showing a cooling capacity graph of a primary stage and a secondary stage when the operating frequency of the compressor is increased to 50 Hz in a cryopump system according to an embodiment of the present invention.

[0028] Figure 2f This is an example diagram showing a cooling capacity graph of a primary stage and a secondary stage when the operating frequency of the compressor is increased to 60 Hz in a cryopump system according to an embodiment of the present invention.

[0029] Figure 3 The present invention is a flowchart of a method for increasing the operating frequency of a compressor in a cryopump system in stages according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. However, the present invention can be implemented in various different ways and is not limited to the embodiments described herein. Furthermore, in order to clearly illustrate the present invention, parts not related to the description are omitted in the accompanying drawings, and similar parts are marked with similar reference numerals throughout the specification.

[0031] Throughout the specification, when a part is described as being "connected" to another part, this includes not only the case of "direct connection" but also the case of "electrical connection" with other elements interposed therebetween. In addition, when a part is described as "including" a certain constituent element, unless otherwise specifically described, it means that other constituent elements are not excluded and other constituent elements can be further included, and it should be understood that the existence or additional possibility of one or more other features or numbers, steps, actions, constituent elements, partial components or combinations thereof is not excluded in advance.

[0032] In this specification, "unit" includes a unit implemented by hardware, a unit implemented by software, and a unit implemented by both. In addition, one unit may be implemented by two or more hardware, or two or more units may be implemented by one unit.

[0033] In this specification, a part of the actions or functions performed by a terminal or device can also be performed in a server connected to the terminal or device instead. Similarly, a part of the actions or functions performed by a server can also be performed in a terminal or device connected to the server.

[0034] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0035] Figure 1a and Figure 1b FIG. 1 is an illustrative diagram showing a cryopump system according to an embodiment of the present invention. Figure 1a The cryopump system 1 is shown and may include a compressor 100 , a helium supply line 101 , a helium recovery line 102 , a cryopump 110 , a temperature measuring unit 120 , a monitoring unit 130 , and a control unit 140 .

[0036] The compressor 100 can compress the helium refrigerant into a high pressure and supply the compressed high-pressure helium refrigerant to the cryopump 110 .

[0037] The helium supply line 101 can supply compressed helium refrigerant from the compressor 100 to the cryopump 110 .

[0038] The compressor 100 recovers the helium refrigerant converted from a high-pressure state to a low-pressure state by the cryopump 110 from the cryopump 110 , and can compress the low-pressure helium refrigerant into a high-pressure helium refrigerant again.

[0039] The helium recovery line 102 can recover low-pressure helium refrigerant from the cryopump 110 to the compressor 100 .

[0040] Generally, the refrigeration capacity of the cryopump 110 increases as the operating frequency of the compressor 100 increases, and the refrigeration capacity of the cryopump 110 decreases as the operating frequency of the compressor 100 decreases.

[0041] Reference Figure 1b The cryopump 110 includes a refrigerator 111, and a cryogenic environment can be constructed by using the refrigerator 111. At this time, in order to construct the cryogenic environment, the cryopump 110 can receive a helium refrigerant compressed into a high pressure from the compressor 100 through the helium supply line 101. The cryopump can include a primary stage 112 and a secondary stage 113.

[0042] In the cooling process, a cryogenic environment can be constructed by utilizing the cooling principle that the refrigerator 111 expands the internal helium (He) refrigerant by moving the primary stage 112 and the secondary stage 113 back and forth in the chamber. Here, the high-pressure helium refrigerant used to construct the cryogenic environment can be converted into a low-pressure state by the cryopump 110.

[0043] The temperature measurement unit 120 can measure the temperature of the secondary stage 113 of the primary stage 112 and the secondary stage 113 of the cryopump 110 .

[0044] The monitoring unit 130 can monitor whether the temperature of the secondary stage 113 reaches a preset secondary reference temperature. Here, the preset secondary reference temperature may be greater than 17K and less than 20K.

[0045] For example, when the compressor 100 operates at an initial operating frequency of 40 Hz to 45 Hz, the monitoring unit 130 can monitor whether the temperature of the secondary stage 113 is a preset secondary reference temperature, ie, 17K or more and 20K or less.

[0046] After the regeneration process, the following phenomenon occurs: when the cryopump 110 starts to operate again, the lowest temperature is maintained, and then the temperature of the secondary stage 113 gradually increases as the gas condenses inside.

[0047] For example, as the process gas is used or the vacuum is maintained for a longer time, the ice accumulated on the adsorption plate (baffle) 115 of the first stage 112 or the adsorption plate (array) 114 of the second stage 113 becomes thicker, so the temperature of the second stage 113 rises. The monitoring unit 130 can monitor whether the temperature of the second stage 113 reaches the preset second reference temperature.

[0048] The controller 140 can operate the compressor 100 in the cooling process according to the initial operating frequency of the compressor 100. Here, the initial operating frequency of the compressor 100 may be 40 Hz to 45 Hz.

[0049] This can provide an effect that the control unit 140 sets the initial operating frequency of the compressor 100 to 40 Hz to 45 Hz, thereby eliminating the need to set the initial operating frequency of the compressor 100 to the highest operating frequency as in the past, thereby reducing power.

[0050] Each time the temperature of the secondary stage 113 reaches the preset secondary reference temperature, the control unit 140 can increase the operating frequency of the compressor 100 in stages through the cryopump 110. For example, each time the preset secondary reference temperature is reached, the control unit 140 can increase the operating frequency of the compressor 100 by 5 Hz to 10 Hz each time, so that the operating frequency of the compressor 100 can be increased to 50 Hz to 60 Hz.

[0051] The controller 140 may execute the regeneration process after the preset secondary reference temperature is exceeded while the compressor 100 is operating at the maximum operating frequency of 60 Hz.

[0052] For example, it is assumed that after the regeneration process, the control unit 140 can operate the compressor 100 at 40 Hz as the initial operating frequency. Thereafter, when the temperature of the secondary stage 113 reaches the preset secondary reference temperature for the first time, the control unit 140 can increase the operating frequency of the compressor 100 by 5 Hz to 45 Hz. Thereafter, when the temperature of the secondary stage 113 reaches the preset secondary reference temperature twice, the control unit 140 can increase the operating frequency of the compressor 100 by 5 Hz to 50 Hz. Thereafter, when the temperature of the secondary stage 113 reaches the preset secondary reference temperature three times, the control unit 140 can increase the operating frequency of the compressor 100 by 5 Hz to 55 Hz. Thereafter, when the temperature of the secondary stage 113 reaches the preset secondary reference temperature four times, the control unit 140 can increase the operating frequency of the compressor 100 by 5 Hz to 60 Hz. At this time, when the operating frequency of the compressor 100 increases by 5 Hz each time, the following effect can be obtained: as the cooling capacity of the secondary stage 113 increases, the temperature of the secondary stage 113 slightly decreases from the preset secondary reference temperature.

[0053] After that, when the operating frequency of the compressor 100 reaches 60 Hz, which is the maximum operating frequency, and the temperature of the secondary stage 113 reaches the preset secondary reference temperature five times, the control unit 140 determines that the regeneration cycle has arrived and the regeneration process can be performed.

[0054] Thus, each time the temperature of the secondary stage 113 reaches the preset secondary reference temperature, the control unit 140 can increase the operating frequency of the compressor 100 in stages, thereby maintaining the temperature of the secondary stage 113 at the preset secondary reference temperature.

[0055] In addition, before the compressor 100 reaches the maximum operating frequency, when the usage time and amount of the process gas reaches the preventive maintenance (PM) cycle, the operating frequency of the compressor 100 can be kept below 60 Hz throughout the cooling process, thereby providing the advantage of further reducing the power of the cryopump system 1.

[0056] Figure 2a to Figure 2f The figure is an example diagram for explaining the cooling capacity and cooling efficiency of the primary stage and the secondary stage according to the change of the operating frequency of the compressor according to one embodiment of the present invention.

[0057] Figure 2a A table showing the cooling capacity and power for the primary stage 112 and the secondary stage 113 as the operating frequency of the compressor 100 increases. Figure 2a In the table, the rightmost column shows the power consumption ratio reduced when each compressor frequency is set at the initial stage of the cooling process compared to 60 Hz (203) which is the maximum operating frequency.

[0058] Figure 2b The temperature and cooling capacity of the primary stage 112 and the secondary stage 113 for all operating frequencies of the compressor 100 are shown. Figure 2b In the graph of , the red dots are points showing the temperature of the first stage portion at 77 K and the temperature of the second stage portion at 20 K in order to measure the cooling capacity of the cryopump.

[0059] Reference Figure 2a , which can provide the following effect: when the operating frequency 200 of the compressor 100 is set to 40 Hz (201) at the initial stage of the cooling process to operate the compressor 100, the power consumption is reduced by about 27% compared with the case where the compressor 100 is set to 60 Hz (203) as the maximum operating frequency at the initial stage of the cooling process to operate the compressor 100.

[0060] Reference Figure 2b It can be confirmed that even if the operating frequency of the compressor 100 is reduced to 40 Hz (201), the primary stage 112 has a cooling capacity of about 80 W, and the secondary stage 113 has a cooling capacity of more than 5 W.

[0061] On the contrary, it can be confirmed that when the operating frequency 200 of the compressor 100 is increased to 40 Hz (201) to 60 Hz (203), as the temperature of the primary stage 112 and the secondary stage 113 increases, a difference in cooling capacity occurs and power consumption also increases.

[0062] Figure 2c The graph showing the results of the argon gas exhaust velocity measurement is shown in FIG. Figure 2a and Figure 2cAs for the suction speed 240 for the pressure 230, it can be confirmed that when the suction speed when the compressor 100 is operated at an operating frequency of 40 Hz (201), the suction speed when the compressor 100 is operated at an operating frequency of 50 Hz (202), and the suction speed when the compressor 100 is operated at an operating frequency of 60 Hz (203) are compared, when the compressor 100 is operated at an operating frequency of 40 Hz (201), 50 Hz (202), and 60 Hz (203), the exhaust speed of argon gas changes within 3%, with almost no change.

[0063] Therefore, it can be confirmed that the operating frequency of the compressor 100 has no effect on the exhaust speed. When maintaining the vacuum, even if the initial operating frequency of the compressor 100 is set to 40 Hz (201), it will not affect the exhaust speed, thereby reducing the power.

[0064] Figure 2d FIG. 1 is an example diagram showing a cooling capacity chart of a primary stage and a secondary stage as the operating frequency of the compressor increases to 40 Hz in a cryopump system according to an embodiment of the present invention. Figure 2e FIG. 1 is an example diagram showing a cooling capacity chart of a primary stage and a secondary stage as the operating frequency of the compressor increases to 50 Hz in a cryopump system according to an embodiment of the present invention. Figure 2f FIG. 1 is an exemplary diagram showing a cooling capacity graph of a primary stage and a secondary stage as the operating frequency of the compressor increases to 60 Hz in a cryopump system according to an embodiment of the present invention.

[0065] Reference Figure 2d to Figure 2f Generally, the higher the operating frequency of the compressor 100, the better the refrigeration capacity, and the slower the operating frequency, the worse the freezing performance. It can be confirmed that when the operating frequency of the compressor 100 increases to 40 Hz ( Figure 2d )、50Hz( Figure 2e )、60Hz( Figure 2f ), the cooling capacity of the first stage portion 112 and the second stage portion 113 gradually moves toward the upper right end and the cooling capacity is improved.

[0066] In the past, during the cooling process, the compressor 100 was operated at a frequency of 60 Hz, and the operating frequency of the compressor was partially adjusted using an inverter to reduce power. However, since there were no experimental results on the refrigeration capacity of the refrigerator 111 of the cryopump 110, it was impossible to confirm whether there was a power reduction effect.

[0067] The present invention enables the compressor 100 to operate in stages from an initial operating frequency to a maximum operating frequency, thereby providing a power reduction effect.

[0068] Figure 3 The present invention is a flowchart of a method for increasing the operating frequency of a compressor in a cryopump system in stages according to an embodiment of the present invention. Figure 3 The method for increasing the operating frequency of the compressor 100 in stages in the cryopump system 1 includes: Figures 1a to 2f Therefore, even if the following contents are omitted, they are also applicable to the embodiments based on Figures 1a to 2f The illustrated embodiment is a method for increasing the operating frequency of the compressor 100 in stages, which is performed in the cryopump system 1 .

[0069] In step S310 , the cryopump system 1 can measure the temperature of the secondary stage 122 of the primary stage 121 and the secondary stage 122 of the cryopump 110 .

[0070] In step S320 , the cryopump system 1 can monitor whether the temperature of the secondary stage 122 reaches a preset secondary reference temperature.

[0071] In step S330 , each time the temperature of the secondary stage 122 reaches the preset secondary reference temperature, the cryopump system 1 can increase the operating frequency of the compressor 100 in stages.

[0072] In the above description, steps S310 to S330 can be further divided into more steps or combined into fewer steps according to the embodiment of the present invention. In addition, some steps can be omitted as needed, and the order of the steps can be changed.

[0073] pass Figures 1a to 3 The method for increasing the operating frequency of the compressor in stages in the cryogenic pump system described above can also be implemented in the form of a computer program stored in a medium and executed by a computer or a recording medium of instructions executable by a computer. Figures 1a to 3 The method of increasing the operating frequency of the compressor in stages and executed in the cryopump system described above can also be realized in the form of a computer program stored in a medium and executed by a computer.

[0074] Computer readable media can be any available media that can be accessed by a computer, including all volatile and nonvolatile media, separable and non-separable media. In addition, computer readable media can include computer storage media. Computer storage media includes all volatile and nonvolatile, separable and non-separable media implemented by any method or technology for storing information such as computer readable commands, data structures, program modules or other data.

[0075] It should be understood that the above description of the present invention is for illustration, and those skilled in the art can easily transform into other specific modes without changing the technical ideas or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative and non-limiting in all aspects. For example, each component described in a single form can also be implemented in a dispersed manner, and the components described in a dispersed form can also be implemented in a combined manner.

[0076] The scope of the present invention is indicated by the claims rather than the detailed description above, and it should be construed that all changes and modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the present invention.

Claims

1. A cryopump system, comprising a cryopump and a compressor for supplying a high-pressure helium refrigerant to the cryopump, wherein: The cryogenic pump system includes: A temperature measuring unit for measuring the temperature of the primary stage and the secondary stage of the cryopump; a monitoring unit, monitoring whether the temperature of the secondary stage reaches a preset secondary reference temperature; and The control unit increases the operating frequency of the compressor in stages each time the temperature of the secondary stage reaches the preset secondary reference temperature.

2. The cryopump system according to claim 1, wherein: The initial operating frequency of the compressor is 40 Hz to 45 Hz. The control part increases the operating frequency of the compressor to 50 Hz to 60 Hz.

3. The cryopump system according to claim 1, wherein: The control unit increases the operating frequency of the compressor by 5 Hz to 10 Hz each time the preset secondary reference temperature is reached.

4. The cryopump system according to claim 1, wherein: The preset secondary reference temperature is greater than 17K and less than 20K.

5. The cryopump system according to claim 1, wherein: When the compressor is operated at a frequency of 60 Hz and the temperature exceeds the preset secondary reference temperature, the control unit performs a regeneration process.

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