KR100754842B1 - Chiller apparatus for semiconductor equipment and method controlling the same - Google Patents

Abstract

A chiller apparatus for semiconductor process equipment and a controlling method thereof are provided to improve refrigeration ability and to minimize variation of a refrigerant amount by using refrigerant liquid supply control valve. A hot gas supply line includes a hot gas electronic valve(216) installed between an output of a compressor(210) and an input of an evaporator(250). The hot gas supply line connects the output of the compressor to the input of the evaporator to control a supply of a high temperature and high pressure refrigerant gas supplied from the compressor to the evaporator. A hot gas supply control line includes a hot gas supply control valve(215) installed between the output of the compressor and an input thereof. The hot gas supply control line connects the output of the compressor to the input thereof to control a supply of the refrigerant gas from the compressor to the input thereof. A high pressure refrigerant liquid supply control line includes a refrigerant supply control valve installed between an output of a liquid receiver and the input of the compressor. The high pressure refrigerant liquid supply control line connects the output to the input of the compressor to control a supply of a high pressure refrigerant liquid from the liquid receiver to the input of the compressor.

Description

Chiller apparatus for semiconductor equipment and method controlling the same

1 is a system diagram showing an example of a chiller apparatus for a conventional semiconductor processing equipment.

2 is a system diagram showing another example of a chiller device for a conventional semiconductor processing equipment.

Figure 3 is a schematic diagram showing a preferred embodiment of the chiller apparatus for a semiconductor processing equipment of the present invention.

The present invention relates to a chiller apparatus for semiconductor processing equipment.

The chiller is a temperature controller for stable process control in the manufacturing process of semiconductor devices. In particular, the chiller is mainly used in the etching and exposure processes of the various processes to keep the temperature of the electrode plate and the chamber (chamber) that generates excessive heat during the process to prevent the breakage of the wafer due to the high temperature and the decrease in productivity.

In the chiller cycle of the chiller that performs this function, the refrigerant path and the brine path overlap each other to perform heat exchange. Here, brine is a solution or liquid with a low freezing point, usually an ethylene glycol mixture is used.

1 is a system diagram showing an example of a chiller apparatus for a conventional semiconductor processing equipment. This example is to control the set temperature of the brine by using the SSR output of the brine heater, to heat the brine by turning on the heater for a long time to increase the temperature of the brine.

First, the circulation path of the refrigerant (for example, freon gas) formed by the refrigeration cycle is as follows.

(1) After the high temperature and high pressure refrigerant discharged from the compressor 10 is condensed in the condenser 20 and phase-changed into a high pressure refrigerant liquid,

(2) the condensed refrigerant liquid is stored in the receiver 30 which is a high pressure tank,

(3) The refrigerant liquid exiting the receiver 30 is expanded by a thermostatic expansion valve 40 (TEV) to change into a low temperature low pressure saturated refrigerant state,

(4) The saturated refrigerant of low temperature and low pressure is evaporated by heat exchange with brine in the evaporator 50 to repeat the flow into the compressor 10 again.

In addition, the brine circulation path is as follows.

(1) After brine exiting the semiconductor processing facility 80 performs heat exchange with the refrigerant in the evaporator 50,

(2) heated in the brine heater 70 via the brine pump 60,

(3) A path flowing into the semiconductor processing facility 80 is again formed.

However, according to this configuration, since the set temperature of the brine is controlled by using the brine heater 70, the power consumption is large, and the use of the brine heater poses an electrical risk. In addition, facility investment costs and operating costs increase due to the installation of related facilities due to high power consumption.

2 is a system diagram showing another example of a chiller device for a conventional semiconductor processing equipment. This example controls the temperature of the brine by controlling the electronic expansion valve.

First, look at the circulation path of the refrigerant formed by the refrigeration cycle as follows.

(1) The high temperature and high pressure refrigerant discharged from the compressor 110 is condensed in the condenser 120 and phase-changed into a high pressure refrigerant liquid,

(2) the condensed refrigerant liquid is stored in the receiver 130 which is a high pressure tank,

(3) The refrigerant liquid exiting the receiver 130 is controlled by the electronic expansion valve 140 received from the temperature controller, the electronic expansion valve 140 is introduced into the evaporator 150 for temperature control of the brine. Control the amount of refrigerant.

(4) The low temperature and low pressure saturated refrigerant is repeatedly evaporated by heat exchange with brine in the evaporator 150 and flowed back into the compressor 110.

In addition, the brine circulation path is as follows.

(1) After brine exiting the semiconductor processing facility 180 performs heat exchange with the refrigerant in the evaporator 150,

(2) heated in the brine heater 170 via the brine pump 160,

(3) A path flowing into the semiconductor processing facility 180 is formed again.

In other words, the chiller apparatus of FIG. 2 is a method of controlling the amount of refrigerant flowing by changing the opening degree of the electronic expansion valve 140 according to the degree of brine cooling load.

According to this method, when the refrigeration load is zero, when the opening degree of the electronic expansion valve 140 is closed, the low pressure portion of the refrigeration cycle is subjected to vacuum operation. In this case, the oil inside the compressor 110 may be transferred to the discharge end, and the compressor 110 may be damaged due to the oil shortage. In addition, during the vacuum operation, due to the excessive compression ratio to give a compression to the compressor (110).

Therefore, in the conventional example of FIG. 2, to compensate for this disadvantage, the low pressure of the refrigeration cycle is compensated by bypassing the hot gas through the hot gas supply control valve 215 during the vacuum operation or the low pressure of 0.5 kg / cm ² or less. I'm using the way. However, in this case, the supply conditions (pressure, temperature, flow rate) of the refrigerant flowing into the inlet of the evaporator 150 are excessively changed, so that precision temperature control of the brine (± 0.1 ° C.) is difficult to expect. In addition, the bypass of the hot gas causes a problem that the freezing capacity is lowered.

Therefore, the present invention is proposed to solve the problems of the prior art, an object of the present invention is to provide a chiller device capable of precise temperature control over a wide range of control temperature range and to ensure the stability of the refrigeration cycle will be.

Other objects, features and advantages of the present invention will be apparent from the examples described below.

The above object includes a compressor, a condenser, a receiver, a main electronic expansion valve, an evaporator, and a refrigerant path for circulating the compressor, wherein the evaporator provides heat exchange with brine provided to the semiconductor processing equipment. Achieved by the chiller device. The chiller apparatus of the present invention connects the compressor output terminal and the input terminal of the evaporator, and installs a hot gas solenoid valve therebetween to control the supply of the high temperature and high pressure refrigerant gas supplied from the compressor to the evaporator. ; A hot gas supply control line connecting the compressor output terminal and the input terminal of the compressor and controlling a supply of a high temperature and high pressure refrigerant gas from the compressor to an input terminal of the compressor by installing a hot gas supply control valve therebetween; And a high pressure refrigerant liquid supply control line connecting the output terminal of the receiver and the compressor input terminal to install a refrigerant liquid supply control valve therebetween to control the supply of the high pressure refrigerant liquid from the receiver to the compressor input terminal.

According to the above structure, the brine temperature can be precisely controlled by improving the refrigerating capacity and minimizing the change in the amount of refrigerant. In addition, by not applying the brine heater, the power consumption is reduced by about 50% compared to the conventional chiller, thereby reducing the electrical auxiliary equipment costs.

Preferably, the valve means is an auxiliary electronic expansion valve, the auxiliary electronic expansion valve may be precisely controlled by a temperature controller based on the temperature detected from the compressor input.

Preferably, the control of the auxiliary electronic expansion valve is made in the range not more than 50% of the amount of the refrigerant flowing into the main electronic expansion valve can be controlled by gradually increasing the flow rate.

The above object includes a compressor, a condenser, a receiver, a main electronic expansion valve, an evaporator, and a refrigerant path for circulating the compressor, wherein the evaporator has a semiconductor process facility in which heat exchange is performed with brine provided to a semiconductor process facility. Applied to a chiller device for supplying, the high temperature and high pressure refrigerant gas from the compressor to the evaporator when the temperature of the brine rises, the opening degree of the main electronic expansion valve is completely closed during the no-load operation of the semiconductor processing equipment, Bypasses the high temperature and high pressure refrigerant gas from the compressor input stage, detects the temperature of the compressor input stage, and controls the amount of refrigerant liquid bypassed from the receiver based on the detected temperature. Of chiller apparatus for semiconductor processing equipment to be supplied to input of compressor It is achieved by the method.

Preferably, even when the brine is controlled at a high temperature of 40 ° C. or higher, the temperature of the compressor input stage may be detected and the amount of refrigerant liquid from the receiver may be controlled and supplied to the input stage of the compressor based on the detected temperature. have.

In addition, when the brine is controlled at a low temperature of −30 ° C. or lower, or operated for a long time with zero freezing capacity, it is possible to periodically supply the high temperature and high pressure refrigerant gas from the compressor to the evaporator.

Preferably, the control of the amount of the refrigerant liquid bypassed from the receiver is made in the range not more than 50% of the amount of the refrigerant flowing into the main electronic expansion valve can be controlled by increasing the flow rate.

EMBODIMENT OF THE INVENTION Hereinafter, the chiller apparatus of this invention is demonstrated in detail with reference to drawings.

Figure 3 is a schematic diagram showing a preferred embodiment of the chiller apparatus for a semiconductor processing equipment of the present invention.

According to the present invention, it is possible to precisely control the temperature of the brine through bypass control of the refrigerant liquid and the refrigerant gas and at the same time ensure the stability of the refrigerant cycle.

First, look at the circulation path of the refrigerant formed by the refrigeration cycle as follows.

After the high temperature and high pressure refrigerant discharged from the compressor 210 is condensed in the condenser 220 and phase-changed into a high pressure refrigerant liquid, the condensed refrigerant liquid is stored in the receiver 230, which is a high pressure tank, and the receiver 230. Refrigerant liquid out of the) is controlled by the main electronic expansion valve 240 received the output of the temperature controller, the main electronic expansion valve 240 controls the amount of refrigerant flowing into the evaporator 250 for temperature control of the brine. do. The low temperature and low pressure saturated refrigerant is repeatedly evaporated by heat exchange with brine in the evaporator 250 and flowed back into the compressor 210.

In addition, in the circulation path of the brine, the brine exiting the semiconductor processing equipment 280 after the heat exchange with the refrigerant in the evaporator 250, the semiconductor processing equipment 280 again through the brine pump 260 Flows into.

In the present invention having such a refrigerant cycle, for the refrigerant bypass control, a pressure setting hot gas supply control valve 215 is provided, the input of which is connected to the output of the compressor 210 and the output of which is an input of the compressor 210. Install to connect In addition, the input terminal of the receiver 230 is connected to the input and the output terminal of the hot gas supply control valve 215 is provided with an auxiliary electronic expansion valve 217, the auxiliary electronic expansion valve 217 is provided It operates by the control of the temperature controller 212 based on the temperature detected by the temperature sensor 211 provided at the input of the compressor 210.

At this time, the auxiliary electronic expansion valve 217 operates by driving the step motor under the control of the temperature controller 212, and is controlled to minimize the amount of refrigerant in the main electronic expansion valve 240. In other words, the control of the temperature controller 212 for controlling the opening degree of the auxiliary electronic expansion valve 217 is such that the change in the amount of refrigerant output from the main electronic expansion valve 240 does not substantially affect the brine temperature. It must be done precisely to make a change.

The refrigerant bypass control according to the present invention can be applied to the following cases, which will be described in detail.

When temperature rises

In the rising mode for raising the temperature of the brine, the hot gas solenoid valve 216 is controlled to bypass the high temperature and high pressure refrigerant gas at the output of the compressor 210 to the input of the evaporator 250 so as to bypass the brine in the evaporator 250. Heat exchange takes place to increase the temperature of the brine.

At this time, the refrigerant bypass control is performed to maintain a constant temperature of the input terminal of the compressor 210. The temperature controller 212 is based on the temperature detected by the temperature sensor 211 installed at the input of the compressor 210. By precisely controlling the auxiliary electronic expansion valve 217, the high pressure refrigerant at the output of the receiver 230 may be supplied to the output of the hot gas supply control valve 215 to control the temperature of the input of the compressor 210 constantly. have.

No load  When driving

When operating under no load with no load in the semiconductor chamber 280, the refrigeration capacity should be zero for the temperature control of the brine. To this end, the opening degree of the main electronic expansion valve 240 is completely closed, and the hot gas supply control valve 215 is opened to bypass the high temperature and high pressure refrigerant gas at the output of the compressor 210 to the compressor 210. At this time, the hot gas supply control valve 215 is set to a constant pressure, and automatically opens when the freezing section low pressure is lower than the set pressure in accordance with the no-load operation.

In this case, the temperature of the refrigerant gas at the input of the compressor 210 increases, which may damage the compressor 210. Therefore, in order to prevent this, the temperature controller 212 opens the auxiliary electronic expansion valve 217 on the basis of the temperature detected by the temperature sensor 211 installed at the input of the compressor 210 to the high pressure of the output of the receiver 230. The refrigerant liquid is supplied to the output terminal of the hot gas supply control valve 215.

According to this configuration, even when the semiconductor chamber 280 is operated under no load without load, the high temperature and high pressure refrigerant gas from the compressor 210 is input using the hot gas supply control valve 215. By bypassing the supply of the high-pressure refrigerant liquid at the output of the receiver 230, the temperature of the input of the compressor 210 can be controlled so as not to be a predetermined temperature, for example, 20 ℃ or more.

The auxiliary electronic expansion valve 217 minimizes the refrigerant amount change of the main electronic expansion valve 240 by controlling the temperature controller 212 based on the temperature detected by the temperature sensor 211 installed at the input of the compressor 210. The temperature can be precisely controlled.

Precise temperature control in normal operation

Refrigerant bypass control is used for precise control of the brine temperature in the temperature control range of the semiconductor process, ie, -30 ° C to 60 ° C.

At this time, in order to precisely control the brine temperature, the main electronic expansion valve 240 controls a static amount of refrigerant corresponding to the required refrigeration capacity. When the amount of refrigerant required to control the main electronic expansion valve 240 is small because the required refrigeration capacity is small, the low pressure portion of the freezing section of the compressor 210 input stage is operated at a low pressure. At this time, when the pressure of the low pressure portion of the freezing section of the compressor 210 is lower than the set pressure, the hot gas supply control valve 215 opens to bypass the high temperature and high pressure refrigerant gas from the compressor 210 to the compressor 210 input terminal. Let's do it. At this time, based on the temperature detected by the temperature sensor 211 installed at the input of the compressor 210, the temperature controller 212 precisely controls the auxiliary electronic expansion valve 217 to control the high-pressure refrigerant liquid at the output of the receiver 230 Is supplied to the output end of the hot gas supply control valve 215 to maintain a constant temperature at the input end of the compressor 210, and at the same time, the auxiliary electronic expansion valve 217 is precisely controlled by the temperature controller 212, thereby maintaining the main electronic expansion valve ( The brine temperature may be precisely controlled by minimizing a change in the amount of refrigerant of the 240.

When the temperature of the semiconductor brine is controlled in a high temperature region, for example, 40 ° C or more, the temperature of the refrigerant gas discharged from the evaporator 250 becomes 40 ° C or more. Therefore, based on the temperature detected by the temperature sensor 211 installed at the input of the compressor 210, the temperature controller 212 opens the auxiliary electronic expansion valve 217 to hot gas refrigerant at the output of the receiver 230. The temperature at the input end of the compressor 210 may be constantly controlled by supplying to the output end of the supply control valve 215.

Oil recovery

When operating in a low temperature region, such as below −30 ° C. or for a long time at zero freezing capacity, oil recovery from the evaporator 250 is essential. Since the chiller for semiconductors is continuously operated 24/7 due to its characteristics, if oil is not recovered from the evaporator 250, the heat exchange capacity of the evaporator 250 is lowered, thereby increasing the temperature of the brine and failure of the compressor 210. May be accompanied.

Therefore, in order to recover the oil of the evaporator 250, it is necessary to control the supply of the high temperature and high pressure refrigerant gas through the hot gas solenoid valve 216 to the input of the evaporator 250 within a range that does not affect the precise temperature control of the brine. There is.

Although the above has been described with reference to the preferred embodiment of the present invention, various changes can be made at the level of those skilled in the art.

Accordingly, unless such modifications or changes are made without departing from the scope of the present invention, they should be construed as belonging to the present invention.

According to the present invention, it is possible to precisely control the brine temperature by minimizing the change in the amount of refrigerant while improving the refrigerating capacity as compared to the conventional electronic expansion valve control method.

In addition, by not applying the brine heater, the power consumption is reduced by about 50% compared to the conventional chiller, thereby reducing the electrical auxiliary equipment costs.

Overall, the stability of the refrigeration cycle by the refrigerant liquid and the refrigerant gas control is improved.

Claims (7)

A chiller device for a semiconductor process facility comprising a compressor, a condenser, a receiver, a main electronic expansion valve, an evaporator, and a refrigerant path circulating through the compressor, the heat exchange with brine provided to the semiconductor process facility in the evaporator, A hot gas supply line connecting the compressor output terminal and the input terminal of the evaporator and controlling a supply of a high temperature and high pressure refrigerant gas supplied from the compressor to the evaporator by installing a hot gas solenoid valve therebetween; A hot gas supply control line connecting the compressor output terminal and the input terminal of the compressor and controlling a supply of a high temperature and high pressure refrigerant gas from the compressor to an input terminal of the compressor by installing a hot gas supply control valve therebetween; And And a high pressure refrigerant liquid supply control line connecting the output terminal of the receiver and the compressor input terminal, and installing a refrigerant liquid supply control valve therebetween to control the supply of the high pressure refrigerant liquid from the receiver to the compressor input terminal. Chiller apparatus for semiconductor processing equipment. The method according to claim 1, The refrigerant liquid supply control valve is an auxiliary electronic expansion valve, And the auxiliary electronic expansion valve is precisely controlled by a temperature controller based on the temperature detected from the compressor input stage. The method according to claim 2, The control of the auxiliary electronic expansion valve is made in the range of not more than 50% of the amount of the refrigerant flowing into the main electronic expansion valve chiller device for a semiconductor processing equipment, characterized in that to control by gradually increasing the flow rate. The compressor includes a compressor, a condenser, a receiver, a main electronic expansion valve, an evaporator, and a refrigerant path circulating through the compressor, and is applied to a chiller device for semiconductor processing equipment in which heat exchange is performed with brine provided to the semiconductor processing equipment. , When the temperature of the brine rises, a high temperature and high pressure refrigerant gas from the compressor is supplied to the evaporator, During the no-load operation of the semiconductor processing equipment, the opening degree of the main electronic expansion valve is completely closed, and the high temperature and high pressure refrigerant gas from the compressor is bypassed to the compressor input stage. In both cases, the chiller for detecting the temperature of the compressor input stage and controlling the amount of refrigerant liquid bypassed from the receiver based on the detected temperature is supplied to the input stage of the compressor. Control method of the device. The method according to claim 4, Even when the brine is controlled at a high temperature of 40 ° C. or higher, the temperature of the compressor input stage is detected, and the amount of refrigerant liquid from the receiver is controlled and supplied to the input stage of the compressor based on the detected temperature. A method of controlling a chiller device for a semiconductor processing equipment. The method according to claim 4, When the brine is controlled at a low temperature of -30 ° C. or lower, or operated for a long time with zero refrigerating capacity (0), the high temperature and high pressure refrigerant gas from the compressor is periodically supplied to the evaporator. Control method of chiller device. The method according to claim 4, The chiller device for the semiconductor processing equipment, characterized in that the control of the amount of the refrigerant liquid bypassed from the receiver is made in a range not exceeding 50% of the amount of the refrigerant flowing into the main electronic expansion valve and is gradually controlled by increasing the flow rate. Control method.

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