CRYOPUMP SYSTEM

Abstract

A cryopump system including a cryopump and a compressor configured to supply a high-pressure helium refrigerant to the cryopump includes a temperature measuring unit configured to measure a temperature of a second stage part among a first stage part and the second stage part of the cryopump, a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature, and a controller configured to incrementally increase an operating frequency of the compressor whenever the temperature of the second stage part reaches the predetermined second reference temperature.

Description

TECHNICAL FIELD

The present disclosure relates to a cryopump system.

BACKGROUND

Cryogenic cooling is widely used in industrial fields such as semiconductor manufacturing and testing. Herein, cryogenic refer to temperatures below −200° C. A cooling process to achieve cryogenic typically includes a compressor, a condenser, an expander, and an evaporator, wherein a refrigerant evaporates in the evaporator to create a cryogenic environment.

In relation to technology for creating a cryogenic environment, prior art Korean Patent Publication No. 2020-0079062 discloses an ultra-cold freezer.

To create a cryogenic environment, GM (Gifford-McMahon) freezers, which are freezers for high-vacuum cryopumps, are mainly used, these freezers for cryopump operates with a motor at its maximum rpm when a temperature of the cryopump initially drops from room temperature to 20K, and after the temperature of the cryopump reaches 20K, the motor of the freezer operates at around 50 to 60 rpm.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

It is conceived to provide a cryopump system that measures a temperature of a second stage part among a first stage part and the second stage part of a cryopump and monitors whether the temperature of the second stage part reaches a predetermined second reference temperature.

It is conceived to provide a cryopump system that incrementally increases an operating frequency of a compressor whenever a temperature of a second stage part reaches a predetermined second reference temperature.

However, the problems intended to be achieved by the present embodiment are not limited to the aforementioned technical objectives, and other problems intended to be solved may also exist.

Means for Solving the Problems

As a means for solving the above-described problems, one embodiment of the present disclosure may provide a cryopump system, which includes a cryopump and a compressor configured to supply a high-pressure helium refrigerant to the cryopump, comprising a temperature measuring unit configured to measure a temperature of a second stage part among a first stage part and the second stage part of the cryopump, a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature, and a controller configured to incrementally increase an operating frequency of the compressor whenever the temperature of the second stage part reaches the predetermined second reference temperature.

According to one embodiment, an initial operating frequency of the compressor may be from 40 Hz to 45 Hz, and the controller may be configured to increase the operating frequency of the compressor to a range of 50 Hz and 60 Hz.

According to one embodiment, the controller may be configured to increase the operating frequency of the compressor by an increment of 5 Hz to 10 Hz whenever the temperature of the second stage part reaches the predetermined second reference temperature.

According to one embodiment, the predetermined second reference temperature may be in a range of 17K to 20K.

According to one embodiment, the controller may be configured to perform a regeneration process after exceeding the predetermined second reference temperature while the compressor operates at an operating frequency of 60 Hz.

The above-described means for solving the problems are merely exemplary and should not be interpreted as intending to limit the disclosure. In addition to the aforementioned exemplary embodiments, additional embodiments described in the drawings and the detailed description of the invention may also exist.

Effects of the Invention

According to any one of the above-described means for solving the problems of the present disclosure, it is possible to provide a cryopump system that measures a temperature of a second stage part among a first stage part and the second stage part of a cryopump and monitors whether the temperature of the second stage part reaches a predetermined second reference temperature.

It is possible to provide a cryopump system that incrementally increases an operating frequency of a compressor whenever a temperature of a second stage part reaches a predetermined second reference temperature and thus reduces power consumption of a cryopump.

The present disclosure provides a cryopump system that does not operate a compressor at its maximum operating frequency from an initial stage of a cooling process, and reduces power consumption by incrementally increasing an operating frequency of the compressor with an increase in temperature caused by an increase in use time or amount of gas condensed.

The present disclosure provides a cryopump system that sets an initial operating frequency of a compressor to be low and operates the compressor, thereby reducing power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an example of a cryopump system according to an embodiment of the present disclosure.

FIG. 1B is an example of a cryopump according to an embodiment of the present disclosure.

FIG. 2A is an example of a table showing cooling capacity and power of a first stage part and a second stage part depending on an increase in an operating frequency of a compressor in the cryopump system according to an embodiment of the present disclosure.

FIG. 2B is an example of showing temperature and cooling capacity of the first stage part and the second stage part at all operation frequencies of the compressor in the cryopump system according to an embodiment of the present disclosure.

FIG. 2C is an example of a graph showing a result of measuring the exhaust rate of argon in the cryopump system according to an embodiment of the present disclosure.

FIG. 2D is an example of a graph showing cooling capacity of the first stage part and the second stage part when the operating frequency of the compressor is increased to 40 Hz in the cryopump system according to an embodiment of the present disclosure.

FIG. 2E is an example of a graph showing cooling capacity of the first stage part and the second stage part when the operating frequency of the compressor is increased to 50 Hz in the cryopump system according to an embodiment of the present disclosure.

FIG. 2F is an example of a graph showing cooling capacity of the first stage part and the second stage part when the operating frequency of the compressor is increased to 60 Hz in the cryopump system according to an embodiment of the present disclosure.

FIG. 3 is a flowchart of a method for incrementally increasing the operating frequency of the compressor in the cryopump system according to an embodiment of the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present disclosure pertains can easily implement it. However, the present disclosure may be embodied in various forms and is not limited to the embodiments described herein. Furthermore, parts unrelated to the explanation have been omitted from the drawings to clearly describe the present disclosure, and similar reference numerals are used for similar parts throughout the specification.

Throughout this specification, when a certain part is described as being “connected” to another part, this includes not only cases where they are “directly connected” but also cases where they are “electrically connected” with other elements interposed therebetween. Additionally, when a certain part is described as “including” a certain component, unless specifically stated otherwise, it does not exclude other components but may further include additional components. It should be understood that this does not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

In this specification, the term “unit” refers to a unit implemented by hardware, a unit implemented by software, or a unit implemented using both. Moreover, one unit may be realized using two or more pieces of hardware, and two or more units may be realized by a single piece of hardware.

In this specification, some of the operations or functions described as being performed by a terminal or device may instead be performed by a server connected to the terminal or device. Similarly, some of the operations or functions described as being performed by a server may instead be performed by a terminal or device connected to the server.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

FIG. 1A and FIG. 1B are examples of a cryopump system according to an embodiment of the present disclosure. FIG. 1A illustrates a cryopump system 1, and the cryopump system 1 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 controller 140.

The compressor 100 may compress a helium refrigerant at high pressure and supply the high-pressure compressed helium refrigerant to the cryopump 110.

The helium supply line 101 may supply the compressed helium refrigerant from the compressor 100 to the cryopump 110.

The compressor 100 may recover, from the cryopump 110, a low-pressure helium refrigerant, which has been converted at high pressure by the cryopump 110, and recompress the low-pressure helium refrigerant into the high-pressure helium refrigerant.

The helium recovery line 102 may recover the low-pressure helium refrigerant from the cryopump 110 into the compressor 100.

In general, as an operating frequency of the compressor 100 increases, the cryopump 110 has a higher freezing capability, and as the operating frequency of the compressor 100 decreases, the cryopump 110 has a lower freezing capability.

Referring to FIG. 1B, the cryopump 110 may include a freezer 111, and use the freezer 111 to create a cryogenic environment. Herein, to create a cryogenic environment, the cryopump 110 may be supplied with a helium refrigerant, which has been compressed at high pressure, from the compressor 100 through the helium supply line 101. The cryopump may include a first stage part 112 and a second stage part 113.

The cryopump 110 may use the freezer 111 in a cooling process to create a cryogenic environment by using a cooling principle that allows the first stage part 112 and the second stage part 113 to reciprocate within a cylinder and expand the helium (He) refrigerant inside the cylinder. Herein, the high-pressure helium refrigerant used for creating a cryogenic environment by the cryopump 110 may be converted into a low-pressure state.

The temperature measuring unit 120 may measure a temperature of the second stage part 113 among the first stage part 112 and the second stage part 113 of the cryopump 110.

The monitoring unit 130 may monitor whether the temperature of the second stage part 113 reaches a predetermined second reference temperature. Herein, the predetermined second reference temperature may be in a range of 17K to 20K.

For example, when the compressor 100 operates at an initial operating frequency of from 40 Hz to 45 Hz, the monitoring unit 130 may monitor whether the temperature of the second stage part 113 reaches the predetermined second reference temperature ranging from 17K to 20K.

The cryopump 110 is maintained at the lowest temperature when it starts operating again after a regeneration process, and as more gas is condensed inside the cryopump 110, the temperature of the second stage part 113 incrementally increases.

For example, when a processing gas is used or as a vacuum holding time increases, ice on an adsorption plate (baffle) 115 of the first stage part 112 or on an adsorption plate (array) 114 of the second stage part 113 increases in thickness and the temperature of the second stage part 113 increases. Therefore, the monitoring unit 130 may monitor whether the temperature of the second stage part 113 reaches the predetermined second reference temperature.

In the cooling process, the controller 140 may operate the compressor 100 based on the initial operating frequency of the compressor 100. Herein, the initial operating frequency of the compressor 100 may be in the range of from 40 Hz to 45 Hz.

Since the controller 140 sets the initial operating frequency of the compressor 100 to be in the range of 40 Hz to 45 Hz instead of using a maximum operating frequency as the initial operating frequency of the compressor 100 as in the conventional manner, it is possible to reduce power consumption.

The controller 140 may incrementally increase the operating frequency of the compressor 100 in the cryopump 110 whenever the temperature of the second stage part 113 reaches the predetermined second reference temperature. For example, the controller 140 may increase the operating frequency of the compressor 100 to a range of 50 Hz and 60 Hz by increasing the operating frequency of the compressor 100 by an increment of 5 Hz to 10 Hz whenever the temperature of the second stage part 113 reaches the predetermined second reference temperature.

The controller 140 may perform a regeneration process after the temperature of the second stage part 113 exceeds the predetermined second reference temperature while the compressor 100 operates at the maximum operating frequency of 60 Hz.

For example, it is assumed that the controller 140 operates the compressor 100 at the initial operating frequency of 40 Hz after the regeneration process. Then, when the temperature of the second stage part 113 reaches the predetermined second reference temperature once, the controller 140 may increase the operating frequency of the compressor 100 by 5 Hz to 45 Hz. Thereafter, when the temperature of the second stage part 113 reaches the predetermined second reference temperature twice, the controller 140 may increase the operating frequency of the compressor 100 by 5 Hz to 50 Hz. Then, when the temperature of the second stage part 113 reaches the predetermined second reference temperature three times, the controller 140 may increase the operating frequency of the compressor 100 by 5 Hz to 55 Hz. Thereafter, when the temperature of the second stage part 113 reaches the predetermined second reference temperature four times, the controller 140 may increase the operating frequency of the compressor 100 by 5 Hz to 60 Hz. Herein, as the operating frequency of the compressor 100 increases by 5 Hz, a cooling capacity of the second stage part 113 is improved. Thus, the temperature of the second stage part 113 can be slightly decrease from the predetermined second reference temperature.

After the operating frequency of the compressor 100 reaches the maximum operating frequency of 60 Hz, the controller 140 may determine that a regeneration cycle has been reached when the temperature of the second stage part 113 reaches the predetermined second reference temperature five times, and may allow the regeneration process to be performed.

Accordingly, whenever the temperature of the second stage part 113 reaches the predetermined second reference temperature, the controller 140 incrementally increases the operating frequency of the compressor 100 to maintain the temperature of the second stage part 113 at the predetermined second reference temperature.

Also, when the use time and amount of processing gas reaches a preventive maintenance (PM) cycle before the operating frequency of the compressor 100 reaches the maximum operating frequency, the compressor 100 can be operated at an operating frequency of 60 Hz or less throughout the cooling process. Thus, it is possible to further reduce power consumption of the cryopump system 1.

FIG. 2A to FIG. 2F are examples of illustrating cooling capacity and cooling efficiency of the first stage part and the second stage part depending on a change in the operating frequency of the compressor according to an embodiment of the present disclosure.

FIG. 2A is a table showing cooling capacity and power of the first stage part 112 and the second stage part 113 depending on an increase in the operating frequency of the compressor 100. In the table of FIG. 2A, the rightmost column represents the ratio of power consumption decreasing at each frequency of the compressor set in the initial stage of the cooling process compared to a maximum operating frequency 203 of 60 Hz.

FIG. 2B shows temperature and cooling capacity of the first stage part 112 and the second stage part 113 at all operation frequencies of the compressor 100. In the graph of FIG. 2B, the red dots represent a temperature of 77K for the first stage part and a temperature of 20K for the second stage part to indicate the cooling capacity of the cryopump.

Referring to FIG. 2A, when the compressor 100 operates at an operating frequency 200 set to 40 Hz 201 in the initial stage of the cooling process, power consumption can be reduced by about 27% compared to a case where the compressor 100 operates at the maximum operating frequency 203 of 60 Hz set to in the initial stage of the cooling process.

Referring to FIG. 2B, it can be seen that even when the operating frequency of compressor 100 is decreased to 40 Hz 201, the first stage part 112 retains a cooling capacity of about 80 W and the second stage part 113 retains a cooling capacity of 5 W or more.

However, it can be seen that when the operating frequency 200 of the compressor 100 is increased from 40 Hz 201 to 60 Hz 203, a difference in freezing capacity occurs due to an increase in temperature of the first stage part 112 and the second stage part 113 and power consumption is also increased.

FIG. 2C is a graph showing a result of measuring the exhaust rate of argon. Referring to FIG. 2A and FIG. 2C, when comparing pumping speeds 240 at different pressures 230 for the compressor 100 operating at frequencies of 40 Hz 201, 50 Hz 202, and 60 Hz 203, it can be seen that a change in exhaust rate of argon is less than 3%, which indicates almost no change.

This confirms that the operating frequency of the compressor 100 does not affect the exhaust rate. During maintenance of a vacuum, even if the compressor 100 operates at the initial operating frequency set to 40 Hz 201, power consumption can be reduced without affecting the exhaust rate.

FIG. 2D is a graph showing cooling capacity of the first stage part and the second stage part when the operating frequency of the compressor is increased to 40 Hz in the cryopump system according to an embodiment of the present disclosure, FIG. 2E is a graph showing cooling capacity of the first stage part and the second stage part when the operating frequency of the compressor is increased to 50 Hz in the cryopump system according to an embodiment of the present disclosure, and FIG. 2F is a graph showing cooling capacity of the first stage part and the second stage part when the operating frequency of the compressor is increased to 60 Hz in the cryopump system according to an embodiment of the present disclosure.

In general, referring to FIG. 2D to FIG. 2F, as the operating frequency of the compressor 100 increases, the cryopump 110 has a higher freezing capability, and as the operating frequency of the compressor 100 decreases, the cryopump 110 has a lower freezing capability. Also, it can be seen that when the operating frequency 200 of the compressor 100 is increased to 40 Hz (FIG. 2D), 50 Hz (FIG. 2E) or 60 Hz (FIG. 2F), the cooling capacity of the first stage part 112 and the second stage part 113 incrementally shifts toward the upper right, which indicates an improvement in cooling capacity.

Conventionally, during the cooling process, the compressor 100 operates at the operating frequency of 60 Hz and an inverter is used to partially adjust the operating frequency of the compressor in order to reduce power consumption. However, no experimental data exists regarding the freezing capacity of the freezer 111 in the cryopump 110. Therefore, it is not possible to confirm whether power consumption reduction can be effectively achieved.

According to the present disclosure, the compressor 100 operates at from an initial operating frequency to a maximum operating frequency. Thus, it is possible to reduce power consumption.

FIG. 3 is a flowchart of a method for incrementally increasing the operating frequency of the compressor in the cryopump system according to an embodiment of the present disclosure. The method for incrementally increasing the operating frequency of the compressor 100 performed by the cryopump system 1 illustrated in FIG. 3 includes the processes time-sequentially performed according to the embodiment illustrated in FIG. 1A to FIG. 2F. Therefore, the descriptions of the processes may also be applied to the method for incrementally increasing the operating frequency of the compressor 100 performed by the cryopump system I according to the embodiment illustrated in FIG. 1A to FIG. 2F even though they are omitted hereinafter.

In a process S310, the cryopump system 1 may measure a temperature of a second stage part 122 among a first stage part 121 and the second stage part 113 of the cryopump 110.

In a process S320, the cryopump system I may monitor whether the temperature of the second stage part 122 reaches a predetermined second reference temperature.

In a process S330, the cryopump system I may incrementally increase an operating frequency of the compressor 100 whenever the temperature of the second stage part 122 reaches the predetermined second reference temperature.

In the descriptions above, the processes S310 to S330 may be divided into additional processes or combined into fewer processes depending on an embodiment. In addition, some of the processes may be omitted and the sequence of the processes may be changed if necessary.

The method for incrementally increasing the operating frequency of the compressor performed by the cryopump system as described above with reference to FIG. 1A to FIG. 3 can be implemented as a computer program stored in a medium to be executed by a computer or a storage medium including instructions executable by a computer. Also, the method for incrementally increasing the operating frequency of the compressor performed by the cryopump system as described above with reference to FIG. 1A to FIG. 3 can be implemented as a computer program stored in a medium to be executed by a computer.

A computer-readable medium may be any available medium accessible by a computer and includes both volatile and non-volatile media, as well as removable and non-removable media. Additionally, the computer-readable medium may include computer storage media. Computer storage media encompass both volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data.

The foregoing description of the present disclosure is provided by way of example, and those skilled in the art to which the present disclosure pertains will understand that various modifications can be made in other specific forms without departing from the technical spirit or essential characteristics of the present disclosure. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as being implemented in a singular form may also be implemented in a distributed manner, and likewise, components described as being distributed may also be implemented in a combined form.

The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and it should be interpreted that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included within the scope of the present disclosure.

Claims

1. A cryopump system including a cryopump and a compressor configured to supply a high-pressure helium refrigerant to the cryopump, comprising: a temperature measuring unit configured to measure a temperature of a second stage part among a first stage part and the second stage part of the cryopump;a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature; anda controller configured to incrementally increase an operating frequency of the compressor whenever the temperature of the second stage part reaches the predetermined second reference temperature.

2. The cryopump system of claim 1, wherein an initial operating frequency of the compressor is from 40 Hz to 45 Hz, andwherein the controller is configured to increase the operating frequency of the compressor to a range of 50 Hz and 60 Hz.

3. The cryopump system of claim 1, wherein the controller is configured to increase the operating frequency of the compressor by an increment of 5 Hz to 10 Hz whenever the temperature of the second stage part reaches the predetermined second reference temperature.

4. The cryopump system of claim 1, wherein the predetermined second reference temperature is in a range of 17K to 20K.

5. The cryopump system of claim 1, wherein the controller is configured to perform a regeneration process after exceeding the predetermined second reference temperature while the compressor operates at an operating frequency of 60 Hz.