Variable-temperature cycle temperature control system and low-temperature cold source unit thereof

Abstract

The utility model discloses a kind of temperature cycling temperature control system and its low-temperature cold source unit, cold source valve box is equipped with the first regenerative outlet and first cold quantity import respectively with refrigerator input end and output end connection, regenerator, first outlet switch valve V13 and first import switch valve V14 are equipped in cold source valve box, first vacuum pump is used to vacuumize cold source valve box, first regenerative outlet is connected in proper order high temperature passage of regenerator, circulating pump, first buffer tank, low temperature passage of regenerator and first import switch valve V14. Through the above optimization design, main pipeline is arranged in cold source valve box, and the inside of valve box is evacuated to form vacuum environment, reduce the convection heat transfer of residual gas molecules in pipeline, reduce the heat leakage of low-temperature working medium, ensure the back gas low-temperature temperature of nitrogen, to maximize the realization of cold quantity recovery and energy saving utilization, simultaneously, buffer tank is set in the inlet end of circulating pump, guarantee the pressure stability of pipeline system, reduce the fluctuation of pipeline system pressure.

Description

Technical Field

[0001] This utility model relates to the field of variable temperature cycle temperature control technology, and in particular to a variable temperature cycle temperature control system and its low temperature cold source unit. Background Technology

[0002] The development and widespread application of semiconductor technology have greatly promoted scientific and technological progress and socio-economic development, making it a key industry supported by the state. With the continuous development of semiconductor manufacturing technology, variable-temperature circulating temperature control systems, used to precisely control the temperature of the reaction chamber in semiconductor manufacturing processes, are indispensable key equipment, widely used in semiconductor manufacturing, testing, and other fields. A variable-temperature circulating temperature control system is a self-balancing circulating device, mainly composed of a heat exchanger, circulating pump, compressor, and control system, capable of continuously providing a temperature-controlled cryogenic medium. This ensures the processing temperatures for steps such as etching, ion implantation, diffusion, thin film deposition, and chemical mechanical polishing in semiconductor manufacturing.

[0003] Currently, most variable-temperature circulating temperature control systems on the market suffer from problems such as narrow temperature range, small cooling capacity, poor temperature control accuracy, short equipment lifespan, and high operational difficulty. These limitations restrict the variable-temperature circulating temperature control performance required in semiconductor manufacturing processes and result in weak support for high and low temperature applications. Therefore, designing a variable-temperature circulating temperature control system with a wide temperature range, large cooling capacity, high temperature control accuracy, long lifespan, and simple operation is of great significance in the semiconductor manufacturing field.

[0004] In practice, the circulating pump is set up in a normal temperature environment. After it is turned on, the inlet is low temperature and the outlet is high pressure, which increases the fluctuation of nitrogen working fluid in the circulation pipeline and causes poor pressure stability in the pipeline. Utility Model Content

[0005] To address the technical problems existing in the background art, this utility model proposes a variable temperature circulating temperature control system and its low temperature cold source unit.

[0006] The present invention proposes a low-temperature cold source unit for a variable temperature circulating temperature control system, comprising: a cold source valve box, a refrigerator, a circulating pump, a first buffer tank, and a first vacuum pump. The first vacuum pump is used to evacuate the cold source valve box. The cold source valve box is provided with a first regenerative outlet and a first cooling capacity inlet, which are respectively connected to the input and output ends of the refrigerator. The cold source valve box is provided with a regenerator, a first outlet switch valve V13, and a first inlet switch valve V14. The first outlet switch valve V13 is connected to the first cooling capacity inlet. The first regenerative outlet is sequentially connected to the high-temperature channel of the regenerator, the circulating pump, the first buffer tank, the low-temperature channel of the regenerator, and the first inlet switch valve V14.

[0007] Preferably, it also includes a second buffer tank, which is disposed on the pipeline between the circulating pump and the high-temperature channel of the regenerator.

[0008] Preferably, it also includes a gas replenishment device, which is connected to the pipeline between the first buffer tank and the low-temperature channel of the regenerator, for replenishing gas into the loop.

[0009] Preferably, a ninth pressure sensor is provided inside the first buffer tank, and the air replenishment device replenishes air into the circuit according to the pressure value detected by the ninth pressure sensor.

[0010] Preferably, the air replenishment device includes a filter, a first diaphragm valve BV1, and a first check valve connected in series along the air intake direction. The filter is used to remove moisture from the intake air.

[0011] Preferably, the air replenishment device further includes a pressure reducing valve, which is disposed on the pipeline between the filter and the first diaphragm valve BV1.

[0012] Preferably, a cold source heater is also provided inside the cold source valve box, and the cold source heater is installed on the pipeline between the first outlet switch valve V13 and the first cold capacity inlet.

[0013] Preferably, the cold source valve box is equipped with two regenerators connected in series, namely a first regenerator and a second regenerator.

[0014] In this invention, the proposed low-temperature cold source unit of the variable-temperature circulating temperature control system has a cold source valve box equipped with a first regenerative outlet and a first cold capacity inlet connected to the input and output ends of the refrigeration unit, respectively. The cold source valve box contains a regenerator, a first outlet switch valve V13, and a first inlet switch valve V14. A first vacuum pump is used to evacuate the cold source valve box. The first regenerative outlet is sequentially connected to the high-temperature channel of the regenerator, the circulating pump, the first buffer tank, the low-temperature channel of the regenerator, and the first inlet switch valve V14. Through this optimized design, the main pipelines are arranged inside the cold source valve box, and the inside of the valve box is evacuated to create a vacuum environment. This reduces the convective heat transfer of residual gas molecules inside the pipelines, reduces heat leakage of the low-temperature working fluid, and ensures the low-temperature return temperature of nitrogen, thereby maximizing cold capacity recovery and energy-saving utilization. Simultaneously, a buffer tank is installed at the inlet end of the circulating pump to ensure the pressure stability of the pipeline system and reduce pressure fluctuations.

[0015] This utility model also includes a variable temperature circulating temperature control system, comprising: the aforementioned low-temperature cold source unit.

[0016] The variable temperature circulating temperature control system proposed in this invention has similar technical effects to the aforementioned low-temperature cold source unit, so it will not be described in detail here. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of one embodiment of the low-temperature cold source unit of a variable temperature cycle temperature control system proposed in this utility model.

[0018] Figure 2 This is a schematic diagram of one embodiment of the variable temperature circulating temperature control system proposed in this utility model.

[0019] Figure 3 This is a schematic diagram of another embodiment of the low-temperature cold source unit of the variable temperature cycle temperature control system proposed in this utility model.

[0020] Figure 4 This is a schematic diagram of another embodiment of the low-temperature cold source unit of the variable temperature cycle temperature control system proposed in this utility model.

[0021] Figure 5 This is a schematic diagram of one embodiment of the low-temperature distribution unit of a variable-temperature circulating temperature control system proposed in this utility model.

[0022] Figure label:

[0023] 1. Cold source valve box; 2. Refrigeration unit; 3. Circulation pump; 4. First vacuum pump; 5. Distribution valve box; 6. Second vacuum pump; 8. Inlet heater; 9. Outlet heater; 11. Primary precooling pipeline; 12. Secondary precooling pipeline; 13. Tertiary precooling pipeline; 14. First regenerator; 15. Second regenerator; 16. First buffer tank; 17. Second buffer tank; 18. First vacuum gauge; 19. Second vacuum gauge; 20. Cold source heater; 21. Low temperature flow controller; 22. Normal temperature flow controller; 23. Nitrogen inlet pipeline; 24. Nitrogen outlet pipeline; 25. Filter;

[0024] 100. Working target plate; 200. Pre-cooling target plate. Detailed Implementation

[0025] Reference Figure 1 The present invention proposes a low-temperature cold source unit for a variable temperature circulating temperature control system, comprising: a cold source valve box 1, a refrigerator 2, a circulating pump 3, a first buffer tank 16, and a first vacuum pump 4. The first vacuum pump 4 is used to evacuate the cold source valve box 1. The cold source valve box 1 is provided with a first regenerating outlet and a first cooling capacity inlet, which are respectively connected to the input and output ends of the refrigerator 2. The cold source valve box 1 is provided with a regenerator, a first outlet switch valve V13, and a first inlet switch valve V14. The first outlet switch valve V13 is connected to the first cooling capacity inlet. The first regenerating outlet is sequentially connected to the high-temperature channel of the regenerator, the circulating pump 3, the first buffer tank 16, the low-temperature channel of the regenerator, and the first inlet switch valve V14.

[0026] To explain the low-temperature cold source unit of this embodiment in detail, refer to... Figure 2This embodiment also proposes a variable temperature circulating temperature control system, including the aforementioned low-temperature cold source unit. Specifically, it further includes a low-temperature distribution unit, which delivers the cold energy from the cold source to the semiconductor processing target and returns the working fluid after the cold energy has been utilized to the low-temperature cold source unit. The low-temperature distribution unit includes a distribution valve box 5 and distribution pipelines disposed within the low-temperature valve box.

[0027] In the specific operation of the low-temperature cold source unit in this embodiment, under the action of the circulating pump 3, nitrogen gas, which serves as the working fluid, is cooled by the refrigerator 2 and enters the cold source valve box 1 through the first cold capacity inlet. The cold capacity is then sent from the cold source valve box 1 to the working target plate 100 through the distribution unit via the first outlet switch valve to cool the target plate for semiconductor processing. The heated nitrogen gas returns to the cold source valve box through the distribution unit, and then passes through the low-temperature channel of the regenerator, the first buffer tank, the circulating pump, and the high-temperature channel of the regenerator in sequence before returning to the input end of the refrigerator through the first regenerator outlet, thus completing the closed-loop circulation of the nitrogen working fluid.

[0028] A first vacuum pump evacuates the interior of the cold source valve box to create a vacuum environment. This vacuum reduces convective heat transfer from residual gas molecules, minimizes heat leakage from the cryogenic working fluid, and ensures the return temperature of nitrogen. Similarly, a second vacuum pump evacuates the distribution valve box to ensure the circulation of nitrogen within the distribution unit.

[0029] In this embodiment, the proposed variable temperature circulating temperature control system and its low-temperature cold source unit have a first regenerative outlet and a first cold energy inlet on the cold source valve box, which are respectively connected to the input and output ends of the refrigeration unit. The cold source valve box contains a regenerator, a first outlet switch valve V13, and a first inlet switch valve V14. A first vacuum pump is used to evacuate the cold source valve box. The first regenerative outlet is sequentially connected to the high-temperature channel of the regenerator, the circulating pump, the first buffer tank, the low-temperature channel of the regenerator, and the first inlet switch valve V14. Through the above optimized design, the main pipelines are arranged inside the cold source valve box, and the inside of the valve box is evacuated to create a vacuum environment. This reduces the convective heat transfer of residual gas molecules inside the pipelines, reduces heat leakage of the low-temperature working fluid, and ensures the low-temperature return temperature of nitrogen, thereby maximizing cold energy recovery and energy-saving utilization. Simultaneously, a buffer tank is installed at the inlet end of the circulating pump to ensure the pressure stability of the pipeline system and reduce pressure fluctuations.

[0030] Reference Figure 3 In a specific embodiment, the low-temperature cold source unit also includes a second buffer tank 17, which is installed on the pipeline between the circulating pump 3 and the high-temperature channel of the regenerator. This further ensures the pressure stability of the upstream and downstream pipelines of the circulating pump.

[0031] In another specific embodiment, the cryogenic cold source unit may further include a gas replenishment device connected to the pipeline between the first buffer tank 16 and the cryogenic channel of the regenerator, for replenishing gas into the loop. During operation, when the nitrogen pressure in the closed loop is insufficient, nitrogen is automatically replenished into the pipeline through the gas replenishment device. By placing the gas replenishment device on the inlet side of the circulating pump, the replenished gas is pre-cooled by the regenerator under the action of the circulating pump before entering the refrigerator for further cooling and then flowing into the circulating working fluid path, thereby minimizing the impact of the replenished gas on the system.

[0032] Furthermore, a ninth pressure sensor is installed inside the first buffer tank 16. The air replenishment device replenishes air into the circuit based on the pressure value detected by the ninth pressure sensor. The pressure value inside the buffer tank is used to detect whether air replenishment is needed in the circuit, thus preventing abnormal detection indicators caused by localized pressurization in the pipeline.

[0033] In the specific design of the air replenishment device, the air replenishment device includes a filter 25, a first diaphragm valve BV1, and a first check valve connected in series along the air intake direction. The filter 25 is used to remove moisture from the intake air. Specifically, the air replenishment device also includes a pressure reducing valve, which is installed on the pipeline between the filter 25 and the first diaphragm valve BV1.

[0034] The function of filter 25 is to remove moisture from the nitrogen introduced into the system. Since water's freezing point is 0°C, if moisture enters the piping system, it can cause blockages, reducing or even eliminating the flow rate. If moisture enters the refrigeration unit, cryogenic switching valve, or cryogenic regulating valve, it can damage the refrigeration unit or valves. The pressure reducing valve controls the nitrogen pressure entering the piping system by adjusting its handle, preventing excessive pressure from damaging the piping. The first diaphragm valve BV1 is mainly used for opening and closing during nitrogen introduction. It is interlocked with the ninth pressure sensor, which monitors the nitrogen pressure inside the piping system. When the pressure drops below a set value, this feedback signal is transmitted to the first diaphragm valve BV1, activating it to begin introducing nitrogen into the piping system. When the pressure reaches the set value, the first diaphragm valve BV1 closes, completing the automatic replenishment of the working fluid into the piping system. To prevent nitrogen from overflowing from the pipeline system, a first check valve is installed at the outlet of the first diaphragm valve BV1. This check valve ensures that the gas can only flow from the outside to the inside, preventing reverse flow and guaranteeing the outflow of gas from the pipeline. This achieves a high degree of automated system operation, completely solving the problem of manual operation, freeing up workers' hands, and improving work efficiency.

[0035] In another specific embodiment, a cold source heater 20 is also provided inside the cold source valve box 1. The cold source heater 20 is installed on the pipeline between the first outlet switch valve V13 and the first cold capacity inlet. Considering the need to output high-temperature working fluid, a cold source heater is provided at the outlet of the refrigeration unit. When the equipment requires a higher temperature, the cold source heater is activated. This heater uses DC power to output power to heat the working fluid. By setting the required working fluid temperature, the power can be adaptively increased, thereby achieving the output of high-temperature working fluid. This avoids the impact caused by the mixing of high and low temperature working fluids, which leads to temperature fluctuations, shortens the system stabilization time, and meets the precise control of continuous low and high temperature zones.

[0036] In other specific embodiments, the cold source valve box 1 is equipped with two regenerators 14 and 15 connected in series. The two regenerators are connected in series to ensure sufficient heat exchanger area. The two regenerators exchange heat between the low-temperature return gas medium from the low-temperature distribution unit and the ambient temperature gas passing through, maximizing the utilization of the low-temperature cold energy of the return gas, achieving cold energy recovery and energy saving. This results in the working fluid entering the refrigeration unit receiving a lower temperature, better utilizing the refrigeration unit's cold energy, and causing the output circulating working fluid temperature to be lower. Compared to other equipment, this results in higher cold energy delivery efficiency and a larger cold energy capacity within the same temperature range.

[0037] The variable temperature circulating temperature control system of this embodiment will be described in detail below through specific examples.

[0038] Reference Figure 4 and 5 This embodiment proposes a variable-temperature circulating temperature control system, which includes a low-temperature cold source unit and a low-temperature distribution unit. The low-temperature cold source unit and the low-temperature distribution unit are connected by a low-temperature double-layer tube. The low-temperature cold source unit mainly provides a circulating fluid with a certain temperature and pressure for the target plate in semiconductor production, forming a closed loop to meet the low-temperature injection conditions required by the target plate. The low-temperature distribution unit is mainly used for the distribution and transportation of the low-temperature circulating medium between the working target plate and the pre-cooled target plate in semiconductor production. The variable-temperature circulating temperature control system of this invention can provide semiconductor manufacturing processes with functions such as a wide temperature range, large cooling capacity, and high-precision temperature control.

[0039] The cryogenic cold source unit includes a cold source valve box, a refrigerator, a first buffer tank 16, a circulating pump, a second buffer tank 17, a cryogenic flow controller 21, a normal temperature flow controller 22, and the refrigerator. The cold source valve box contains a cryogenic switching valve V14, a first regenerator 14, a second regenerator 15, a cold source heater, and cryogenic switching valves V13 and V15. A first vacuum pump evacuates the inside of the cold source valve box to create a vacuum environment. This vacuum environment reduces convective heat transfer from residual gas molecules, minimizes heat leakage from the cryogenic working fluid, and ensures the cryogenic return temperature of nitrogen.

[0040] The low-temperature cold source unit and the low-temperature distribution unit are connected via a low-temperature double-layer pipe. The first regenerator 14 and the second regenerator 15 are connected in series. The inlet and outlet of the series-connected heat exchangers are equipped with an eighth, ninth, tenth, and eleventh temperature sensor, an eighth pressure sensor, and an eleventh pressure sensor, respectively, to monitor the temperature and pressure of the working fluid at the inlet and outlet of the regenerators. The outlet of the first buffer tank 16 and the inlet of the second buffer tank 17 are connected via a single-layer pipe, and a circulation pump for driving the working fluid circulation is installed between them. The first buffer tank 16 is equipped with a ninth pressure sensor, and the second buffer tank 17 is equipped with a tenth pressure sensor and a ninth pressure relief valve. A low-temperature flow controller 21 is connected between the outlet of the second buffer tank 17 and the inlet of the second regenerator 15 via a single-layer pipe, used to deliver and regulate low-temperature gas into the second regenerator 15 for pre-cooling. A normal-temperature flow controller 22 is connected between the outlet of the second buffer tank 17 and the outlet of the refrigeration unit via a single-layer pipe, used to deliver and regulate high-temperature gas into the low-temperature distribution unit.

[0041] The refrigerator outlet is equipped with a cold source heater, which is used to mix the high-temperature gas passing through the ambient temperature flow controller 22 and the low-temperature gas passing through the low-temperature flow controller 21. The temperature of the working fluid at the refrigerator outlet is regulated by mixing. The outlet of the cold source heater and the inlet of the low-temperature switching valve V13 are connected by a pipeline. A first-stage low-temperature switching valve V15 is provided for the first-stage pre-cooling closed-loop circulation of the low-temperature cold source unit, and a twelfth temperature sensor is also provided.

[0042] The cold source valve box is connected to the first vacuum pump through a pipeline, and an electromagnetic valve is installed between them to control the start and stop of vacuuming in the interlayer of the cold source valve box. The first vacuum gauge 18 is connected to the outside of the cold source valve box to monitor the vacuum level of the interlayer of the cold source valve box.

[0043] The inlet pipe of the first buffer tank 16 is sequentially connected to a first check valve, a first diaphragm valve BV1, a pressure reducing valve, and a filter 25 for nitrogen replenishment of the piping system. The inlet pipe of the first buffer tank 16 is connected to a second diaphragm valve BV2 for evacuation and purging of the low-temperature cold source unit piping.

[0044] The cryogenic distribution unit includes a distribution valve box, a working target plate, and a precooling target plate. The distribution valve box is connected to the second vacuum pump via a pipeline and is equipped with a second solenoid valve for controlling the start and stop of vacuuming in the interlayer of the cryogenic valve box. A second vacuum gauge 19 is connected to the outside of the cryogenic valve box to monitor the vacuum level in the interlayer of the distribution valve box.

[0045] The inlet of the secondary cryogenic switching valve V16 is connected to the outlet of the cryogenic cold source unit, and its outlet is connected to the inlet of the cryogenic cold source unit, serving as the on / off control for the secondary precooling pipeline. The outlet of the cryogenic cold source unit is equipped with a first temperature sensor, a first pressure sensor, and a first pressure relief valve SRV1.

[0046] The piping system surrounding the working target plate 100 is sequentially connected to a first cryogenic throttling valve TV1, a cryogenic switching valve V3, the working target plate 100, and a cryogenic switching valve V5. The inlet of the first cryogenic throttling valve TV1 is connected to the outlet of the cryogenic cold source unit, and the outlet of the cryogenic switching valve V5 is connected to the inlet of the cryogenic cold source unit. The cryogenic throttling valve TV1 is used to control the temperature of the working fluid entering the working target plate. A seventh pressure sensor is installed at the outlet of the cryogenic switching valve V5.

[0047] The inlet of the three-stage cryogenic switching valve V17 is connected to the outlet of the first cryogenic throttling valve TV1, and its outlet is connected to the inlet of the cryogenic cold source unit, serving as the on / off control for the three-stage precooling pipeline. The outlet of the first cryogenic throttling valve TV1 is equipped with a third temperature sensor, a third pressure sensor, and a third pressure relief valve SRV3.

[0048] A fourth pressure sensor, a fourth pressure relief valve SRV4, and a cryogenic switching valve V11 are installed in the pipeline between the inlet of the working target plate 100 and the outlet of the cryogenic switching valve V3. A fourth pressure sensor is installed at the outlet of the working target plate.

[0049] The piping system surrounding the precooling target plate 200 is sequentially connected to a cryogenic throttling valve TV2, a cryogenic switching valve V4, the precooling target plate 200, and a cryogenic switching valve V6. The inlet of cryogenic throttling valve TV2 is connected to the outlet of the cryogenic cold source unit, and the outlet of cryogenic switching valve V6 is connected to the inlet of the cryogenic cold source unit. Cryogenic throttling valve TV2 controls the temperature of the working fluid entering the precooling target plate. The inlet of cryogenic switching valve V18 is connected to the outlet of the second cryogenic throttling valve TV2, and its outlet is connected to the inlet of the cryogenic cold source unit, serving as the on / off control for the three-stage precooling pipeline. Specifically, the outlet of cryogenic throttling valve TV2 is equipped with a second temperature sensor, a second pressure sensor, and a first pressure relief valve SRV2. The piping between the inlet of the precooling target plate and the outlet of cryogenic switching valve V4 is equipped with a fifth pressure sensor, a fifth pressure relief valve SRV5, and a cryogenic switching valve V12. The outlet of the precooling target plate is equipped with a fifth pressure sensor.

[0050] The reheat piping system for the working target plate is sequentially connected to the second check valve, the third diaphragm valve, the target plate inlet heater, the cryogenic switch valve V7, the working target plate, the cryogenic switch valve V9, the target plate outlet heater, and the third check valve. A sixth pressure sensor is installed at the inlet of the target plate inlet heater, and a sixth temperature transmitter is installed at the outlet. A seventh temperature sensor is installed at the outlet of the target plate outlet heater. The reheat piping system for the precooled target plate is sequentially connected to the second check valve, the third diaphragm valve, the target plate inlet heater, the cryogenic switch valve V8, the working target plate, the cryogenic switch valve V10, the target plate outlet heater, and the third check valve.

[0051] The pressure relief valves SRV1, SRV2, SRV3, SRV4, SRV5, SRV6, and SRV7, which are connected to the internal pipelines of the cryogenic valve box, are then connected to the first and second silencers after being aggregated. The nitrogen discharge pipeline of the rewarming pipeline is also aggregated with the discharge pipeline of the pressure relief valves and then discharged through the second silencer.

[0052] A first solenoid valve is installed between the cold source valve box and the first vacuum pump to control the opening and closing of the extraction pipe. A first vacuum gauge 18 is connected to the cold source valve box to monitor the vacuum level of the internal interlayer. When the vacuum level exceeds a set value, this feedback signal is transmitted to the first solenoid valve and the first vacuum pump. Following the principle of starting the first vacuum pump first and then opening the first solenoid valve, external air is prevented from entering the cold source valve box, which could cause instantaneous frost or condensation. When the vacuum level reaches the set value, the first solenoid valve is closed first, followed by the first vacuum pump, maintaining the internal vacuum. This interlocking feedback design, by measuring the pressure inside the pipe, enables automatic gas replenishment, achieving a high degree of system automation. This completely solves the problem of manual operation, freeing up workers' hands and improving work efficiency.

[0053] The cold source valve box contains two regenerators, namely the first regenerator 14 and the second regenerator 15, which are connected in series to ensure sufficient heat exchange area. These two regenerators exchange heat between the low-temperature return gas medium from the low-temperature distribution unit and the ambient temperature gas passing through the outside, maximizing the utilization of the low-temperature cooling capacity of the return gas. This achieves cooling capacity recovery and energy saving, resulting in a lower temperature for the working fluid entering the refrigeration unit, better utilizing the refrigeration unit's cooling capacity, and lower output circulating working fluid temperature. Compared to other equipment, this results in higher cooling capacity delivery efficiency and a larger cooling capacity within the same temperature range. The return gas pipeline inlet of the regenerator is equipped with an eighth temperature sensor and an eighth pressure sensor to monitor the temperature and pressure of the return gas inlet; the return gas pipeline outlet of the regenerator is equipped with a ninth temperature sensor, and the first buffer tank 16 is equipped with a ninth pressure sensor to monitor the temperature of the return gas outlet; the inlet of the regenerator's air inlet is equipped with a tenth temperature sensor, and the second buffer tank 17 is equipped with a tenth pressure sensor to monitor the temperature and pressure of the air inlet; the outlet of the regenerator's air outlet is equipped with an eleventh temperature sensor and an eleventh pressure sensor to monitor the temperature and pressure of the air inlet and outlet.

[0054] The cryogenic cooling unit is powered by a circulating pump, which uses a scroll compressor as the driving force for circulating the working fluid. To ensure the pressure stability of the piping system and reduce pressure fluctuations, a first buffer tank 16 is installed at the inlet of the circulating pump, and a second buffer tank 17 is installed at the outlet of the circulating pump, with a combined volume of 250L. Since the inlet is at a low temperature and the outlet is at a high pressure after the circulating pump is turned on, a ninth pressure relief valve is installed on the second buffer tank to ensure that excessive pressure in the piping system can be discharged through the pressure relief valve, preventing equipment damage and ensuring the personal safety of operators.

[0055] An automatic nitrogen replenishment device is installed in the inlet pipe of the first buffer tank 16, comprising a filter 25, a pressure reducing valve, a first diaphragm valve BV1, and a first check valve. The filter 25 removes moisture from the replenished nitrogen. Since water's freezing point is 0°C, if moisture enters the piping system, it can cause blockages, reducing or even eliminating the flow rate. If moisture enters the refrigeration unit, cryogenic switching valve, or cryogenic regulating valve, it can damage the refrigeration unit or valves. The pressure reducing valve controls the nitrogen pressure entering the piping system by adjusting its handle to prevent excessive pressure from damaging the piping. The first diaphragm valve BV1 is mainly used to open and close during nitrogen replenishment. The diaphragm valve is interlocked with a ninth pressure sensor, which monitors the nitrogen pressure inside the piping system. When the pressure drops below a set value, this feedback signal is transmitted to the first diaphragm valve BV1, activating it to begin replenishing nitrogen into the piping system. When the pressure reaches the set value, the first diaphragm valve BV1 closes, completing the automatic replenishment of the working fluid into the piping system. The system achieves a high degree of automation, completely solving the problem of manual operation, freeing up workers' hands, and improving work efficiency. To prevent nitrogen from overflowing outwards from the pipeline system, a first one-way valve is installed at the outlet of the first diaphragm valve BV1. The first one-way valve ensures that the gas can only flow from the outside to the inside and cannot flow in the opposite direction, thus guaranteeing the outflow of gas from inside the pipeline.

[0056] The outlet of the second buffer tank 17 has two working fluid output pipelines. One pipeline passes through the low-temperature flow controller 21 and enters the inlet of the second regenerator 15, where it exchanges heat with the low-temperature return gas, making it a low-temperature fluid entering the inlet of the refrigerator. The refrigerator further cools the low-temperature fluid through its internal cold head and heat exchanger, thus outputting a lower-temperature circulating working fluid and reducing the cooling loss within the refrigerator. The other pipeline passes through the ambient temperature flow controller 22 and enters the outlet of the refrigerator. Based on the value of the twelfth temperature sensor at the refrigerator outlet, the opening of the low-temperature flow controller 21 and the ambient temperature flow controller 22 is adjusted to obtain the required output working fluid temperature. Considering the need to output high-temperature working fluid, a cold source heater is installed at the outlet of the refrigerator. When the equipment requires a higher temperature, the cold source heater is activated. This heater uses DC power to output power to heat the working fluid. By setting the required working fluid temperature, the power output can be adaptively increased, thereby achieving the output of high-temperature working fluid. This avoids temperature fluctuations caused by the mixing of high and low temperature working fluids, shortens the system stabilization time, and meets the precise control of continuous low and high temperature zones.

[0057] The circulating system features multi-stage precooling piping for easy step-by-step testing and ensures target plate safety. To improve production efficiency, two cryogenic injection lines are designed, capable of simultaneously supplying cooling energy to both the working and precooling target plates. The precooling target plate undergoes precooling treatment first; after precooling, the process continues to the working target plate for final cryogenic injection. An independent reheating line is designed for rapid reheating of the target plate.

[0058] The first stage of precooling is initiated, with the working fluid circulating along the precooling pipeline. The pipeline connections are as follows: first regenerator 14 return port, second regenerator 15 first regenerator 14 return port, first buffer tank 16, circulating pump, second buffer tank 17, cryogenic flow controller 21, second regenerator 15 inlet, first regenerator 14 inlet, refrigerator, and cryogenic on / off valve V15. This first stage of precooling is primarily used for the self-circulation start-up and cooling of the cryogenic cold source unit. The refrigerator starts up to lower the working fluid from room temperature to a minimum temperature of -150℃, and the operation of the cold source unit is monitored during the cooling process. After the primary precooling is completed, the cryogenic switch valve V15 is closed, and the secondary precooling is started. The working fluid circulates along the secondary precooling pipeline. The pipeline connections are as follows: cryogenic switch valve V14, return port of the first regenerator 14, return port of the first regenerator 14 of the second regenerator 15, first buffer tank 16, circulating pump, second buffer tank 17, cryogenic flow controller 21, inlet of the second regenerator 15, inlet of the first regenerator 14, refrigerator, cryogenic switch valve V13, and cryogenic switch valve V16. This secondary precooling is mainly used for the self-circulation start-up cooling of the cryogenic cold source unit and the cryogenic distribution unit. The cryogenic cold source unit and the cryogenic distribution unit are connected by a cryogenic double-layer pipe, which transports the -150°C cryogenic working fluid generated by the refrigerator to the secondary pipeline of the cryogenic distribution valve box, and monitors the operation of the working fluid during the process of transporting it from the cryogenic cold source unit to the cryogenic distribution unit.

[0059] After the secondary precooling is completed, the cryogenic switch valve V16 is closed, and the tertiary precooling is started. The tertiary precooling is connected in parallel in two paths: the working target plate tertiary precooling and the precooling target plate tertiary precooling. The working fluid in the working target plate tertiary precooling circulates along the tertiary precooling pipeline, which is connected in the following order: cryogenic switch valve V14, return port of the first regenerator 14, return port of the first regenerator 14 of the second regenerator 15, first buffer tank 16, circulating pump, second buffer tank 17, cryogenic flow controller 21, inlet of the second regenerator 15, inlet of the first regenerator 14, refrigerator, cryogenic switch valve V13, cryogenic throttling valve TV1, and cryogenic switch valve V17. The working target plate tertiary precooling is mainly used to regulate the opening of the cryogenic regulating valve TV1 to achieve throttling and cooling of the cryogenic working fluid. The lowest temperature after throttling by the cryogenic regulating valve TV1 is obtained by monitoring the third temperature sensor. The working fluid in the three-stage precooling of the precooling target plate circulates along the three-stage precooling pipeline. The pipeline connections are as follows: cryogenic switch valve V14, return port of the first regenerator 14, return port of the second regenerator 15, first buffer tank 16, circulating pump, second buffer tank 17, cryogenic flow controller 21, inlet of the second regenerator 15, inlet of the first regenerator 14, refrigerator, cryogenic switch valve V13, cryogenic throttling valve TV2, and cryogenic switch valve V18. The three-stage precooling of the precooling target plate is mainly used to control the opening of the cryogenic regulating valve TV2 to achieve throttling and cooling of the cryogenic working fluid. The lowest temperature after throttling by the cryogenic regulating valve TV2 is obtained by monitoring the second temperature sensor. The lowest temperature of similar equipment in China can only reach -120℃. This system has a wider application temperature range and adopts throttling and pressure reduction cooling technology. It is equipped with a cryogenic throttling valve to reduce the nitrogen temperature to below -160℃ through pressure reduction.

[0060] After the three-stage precooling is completed, the cryogenic switching valves V17 and V18 are closed, and the working target plate circulation system and the precooling target plate circulation system are started. The working fluid in the working target plate circulation system circulates along the working target plate circulation system pipeline, which is connected in the following order: cryogenic switching valve V14, return port of the first regenerator 14, return port of the first regenerator 14 of the second regenerator 15, first buffer tank 16, circulation pump, second buffer tank 17, cryogenic flow controller 21, inlet of the second regenerator 15, inlet of the first regenerator 14, refrigerator, cryogenic switching valve V13, cryogenic throttling valve TV1, cryogenic switching valve V3, working target plate, and cryogenic switching valve V5. The cryogenic working fluid is further throttled and cooled by the cryogenic throttling valve TV1 before being delivered to the working target plate, which is used for cryogenic injection.

[0061] The working target plate is equipped with a fourth pressure relief valve SRV4 at its inlet. When the pressure of the working fluid in the pipeline entering the cryogenic target plate exceeds a certain value, the discharge pressure of the fourth pressure relief valve SRV4 is reached, discharging the working fluid from the pipeline to prevent damage to the working target plate due to excessive pipeline pressure, thus protecting the working target plate. A cryogenic switching valve V11 is also provided for evacuating and replacing the pipeline of the working target plate circulation system. The working fluid of the precooling target plate circulation system circulates along the precooling target plate circulation system pipeline. The pipeline connections are as follows: cryogenic switching valve V14, return port of the first regenerator 14, return port of the second regenerator 15, first buffer tank 16, circulation pump, second buffer tank 17, cryogenic flow controller 21, inlet of the second regenerator 15, inlet of the first regenerator 14, refrigerator, cryogenic switching valve V13, cryogenic throttling valve TV2, cryogenic switching valve V4, precooling target plate, and cryogenic switching valve V6. The cryogenic working fluid is further throttled and cooled by the cryogenic throttling valve TV2 before being delivered to the precooling target plate, which is used for process precooling. The inlet of the precooling target plate is equipped with a fifth pressure relief valve SRV5. When the pressure of the working fluid entering the precooling target plate exceeds a certain value, the discharge pressure of the fifth pressure relief valve SRV5 is reached, discharging the working fluid from the pipeline to prevent damage to the precooling target plate due to excessive pipeline pressure, thus protecting the precooling target plate. The outlet of the cryogenic distribution unit is equipped with a seventh pressure relief valve SRV7 for overpressure relief protection of the return gas pipeline. A cryogenic on / off valve V12 is also provided for evacuation and replacement of the pipeline in the precooling target plate circulation system.

[0062] The cryogenic distribution unit has an independent target plate reheating pipeline, including a working target plate reheating system and a pre-cooled target plate reheating system. The connecting pipelines of the working target plate reheating system are as follows: ambient temperature nitrogen passes through a second one-way valve, a third diaphragm valve, a target plate inlet heater, a cryogenic switch valve V7, the working target plate, a cryogenic switch valve V9, a target plate outlet heater, and the third one-way valve. The third diaphragm valve controls the opening and closing of the nitrogen entering the target plate reheating system. The second one-way valve prevents backflow of nitrogen in the pipeline and also includes a sixth pressure relief valve (SRV6) for safe release of pressure in case of overpressure in the working target plate reheating system, protecting the working target plate. The target plate outlet heater further heats the nitrogen that has undergone heat exchange with the working target plate, preventing the discharged cryogenic nitrogen from frosting or even freezing in the pipeline, which could eventually melt into water and affect equipment operation. A third one-way valve at the outlet prevents external air from flowing back into the target plate, which could cause damage due to the freezing of moisture in the air. The connecting pipelines of the precooled target plate reheating system are as follows: ambient temperature nitrogen gas passes through the second check valve, the third diaphragm valve, the target plate inlet heater, the cryogenic switch valve V8, the precooled target plate, the cryogenic switch valve V10, the target plate outlet heater, and the third check valve.

[0063] A second solenoid valve is installed between the distribution valve box and the second vacuum pump to control the opening and closing of the extraction pipe. A second vacuum gauge 19 is connected to the distribution valve box to monitor the vacuum level of the internal interlayer. When the vacuum level exceeds a set value, this feedback signal is transmitted to the second solenoid valve and the second vacuum pump. Following the principle of starting the second vacuum pump first and then opening the second solenoid valve, external air is prevented from entering the cryogenic valve box, which could cause instantaneous frost or condensation. When the vacuum level reaches the set value, the second solenoid valve is closed first, followed by the second vacuum pump, to maintain the internal vacuum.

[0064] All sealable pipelines in the system are equipped with safety relief valves. If the working fluid pressure in the pipeline becomes too high during system operation, it can be released through these valves to prevent equipment damage due to excessive pressure and ensure personnel safety. The distribution valve box in the cryogenic distribution unit is sequentially connected to the following internal pipelines: first pressure relief valve SRV1, first pressure relief valve SRV2, third pressure relief valve SRV3, fourth pressure relief valve SRV4, fifth pressure relief valve SRV5, sixth pressure relief valve SRV6, and seventh pressure relief valve SRV7. These pressure relief valves effectively address the issue of excessive nitrogen pressure emissions in the segmented pipelines, protecting the working target plate and pre-cooling target plate. The collected nitrogen gas is then connected to the first and second silencers for noise reduction. Simultaneously, the nitrogen gas discharged after reheating is also collected by the pressure relief valve discharge pipes and discharged through the second silencer.

[0065] This embodiment has the following advantages:

[0066] 1. The system selects nitrogen as the circulating working medium, which, compared to other working media, has significant advantages such as low cost, easy availability, non-toxicity, harmlessness, and no pollution, meeting the needs of long-cycle semiconductor production. The technical problem to be solved is to provide a variable-temperature circulating temperature control system with a wide temperature range, large cooling capacity, high temperature control accuracy, long lifespan, and simple operation, which is of great significance in the semiconductor manufacturing field. This system can be widely used in semiconductor manufacturing, testing, and other fields, and is suitable for equipment in semiconductor production lines. It can continuously provide a temperature-controllable cryogenic medium to ensure the required processing temperatures in equipment chambers for processes such as etching, ion implantation, and diffusion in semiconductor factories.

[0067] 2. It adopts a regenerative closed-loop structure design, which can maximize the recovery of cold energy and energy-saving utilization. It can achieve large flow and large cold energy transportation. Compared with other equipment, it has higher cold energy transportation efficiency and larger cold energy in the same temperature range.

[0068] 3. The output temperature of the fluid is controlled by two methods: high and low temperature fluid mixing and thermal counteraction. The working fluid is fully heated into a gaseous state by a heater. Then, the gas is divided into two streams by a normal temperature flow controller 2222 and a low temperature flow controller 21. The two streams are mixed at the outlet of the refrigerator. Finally, the outlet temperature is precisely controlled by adjusting the power of the heater at the outlet. At the same time, this method can avoid the impact caused by the mixing of high and low temperature working fluids, which leads to temperature fluctuations, shortens the system stabilization time, and achieves precise temperature control of the working fluid.

[0069] 4. It adopts throttling, pressure reduction and cooling technology. It is equipped with a low temperature throttling valve to reduce the nitrogen temperature to below -160℃ through pressure reduction. The lowest temperature of similar equipment in China can only reach -120℃. This system has a wider application temperature range.

[0070] 5. In terms of system process, a multi-stage pre-cooling design is implemented to facilitate step-by-step testing and ensure the safety of the target plate. In order to improve the low-temperature injection efficiency in semiconductor production, two low-temperature injection pipelines are designed to simultaneously deliver cold energy to the working target plate and the pre-cooling target plate. The pre-cooling target plate is pre-cooled first. After the pre-cooling treatment is completed, the process continues to transfer to the working target plate to complete the final low-temperature injection.

[0071] 6. An independent rewarming pipeline system for the target plate is designed. Room temperature nitrogen gas rapidly heats up after passing through a heater, becoming hot nitrogen gas. This heated nitrogen gas is then transported to the cryogenic target plate, utilizing the heat of the nitrogen to rewarm the cryogenic target plate. This rapid rewarming significantly improves working efficiency. Simultaneously, an exhaust heater is installed at the target plate outlet to further heat the cryogenic nitrogen gas after heat exchange with the target plate, preventing frost or even ice formation on the pipeline after the cryogenic nitrogen gas is discharged.

[0072] 7. All sealable pipelines in the system are equipped with safety relief valves. If the working fluid pressure in the pipeline is too high during system operation, it can be released from the safety relief valve to avoid equipment damage caused by excessive pipeline pressure, and at the same time ensure personnel safety.

[0073] 8. The system adopts an interlocking feedback design. By measuring the pressure value inside the pipe, it can achieve automatic gas replenishment; by measuring the vacuum value of the jacket, it can automatically start the pump for evacuation. This design fully realizes the highly automated operation of the system, completely solves the problem of manual operation, frees up workers' hands, and improves work efficiency.

[0074] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A low-temperature cold source unit for a variable-temperature circulating temperature control system, characterized in that, include: The cold source valve box (1), the refrigerator (2), the circulating pump (3), the first buffer tank (16) and the first vacuum pump (4) are provided. The first vacuum pump (4) is used to evacuate the cold source valve box (1). The cold source valve box (1) is provided with a first regenerating outlet and a first cooling capacity inlet that are respectively connected to the input end and the output end of the refrigerator (2). The cold source valve box (1) is provided with a regenerator, a first outlet switch valve V13 and a first inlet switch valve V14. The first outlet switch valve V13 is connected to the first cooling capacity inlet. The first regenerating outlet is connected in sequence to the high temperature channel of the regenerator, the circulating pump (3), the first buffer tank (16), the low temperature channel of the regenerator and the first inlet switch valve V14.

2. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 1, characterized in that, It also includes a second buffer tank (17), which is installed on the pipeline between the circulating pump (3) and the high-temperature channel of the regenerator.

3. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 1, characterized in that, It also includes a gas replenishment device, which is connected to the pipeline between the first buffer tank (16) and the low-temperature channel of the regenerator, and is used to replenish gas into the loop.

4. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 3, characterized in that, The first buffer tank (16) is equipped with a ninth pressure sensor, and the air replenishment device replenishes air into the circuit according to the pressure value detected by the ninth pressure sensor.

5. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 3, characterized in that, The air replenishment device includes a filter (25), a first diaphragm valve BV1 and a first check valve connected in series along the air intake direction. The filter (25) is used to remove moisture from the intake air.

6. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 5, characterized in that, The air supply device also includes a pressure reducing valve, which is installed on the pipeline between the filter (25) and the first diaphragm valve BV1.

7. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 1, characterized in that, The cold source valve box (1) is also equipped with a cold source heater (20), which is installed on the pipeline between the first outlet switch valve V13 and the first cold capacity inlet.

8. The low-temperature cold source unit of the variable temperature circulating temperature control system according to claim 1, characterized in that, The cold source valve box (1) is equipped with two first regenerators (14) and second regenerators (15) connected in series.

9. A variable temperature circulating temperature control system, characterized in that, include: The low-temperature cold source unit according to any one of claims 1-8.

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