Self-recovery cascade semiconductor temperature control system with pre-cooling and control method thereof

Abstract

The application relates to the technical field of special temperature control systems for semiconductors in the integrated circuit industry, and provides a self-recovery cascade semiconductor temperature control system with precooling and a control method thereof, wherein the self-recovery cascade semiconductor temperature control system with precooling comprises a circulating liquid subsystem, a precooling subsystem and a self-recovery cascade subsystem; the precooling subsystem comprises a first evaporator and a precooling compressor, and the precooling subsystem is connected with the circulating liquid subsystem through the first evaporator; the self-recovery cascade subsystem comprises a self-recovery cascade compressor, a second evaporator and a condensation evaporator, the self-recovery cascade subsystem is connected with the circulating liquid subsystem through the second evaporator, and the self-recovery cascade subsystem is connected with the precooling subsystem through the condensation evaporator. The application realizes the improvement of the application range of the self-recovery cascade refrigeration system, can realize stable operation in a high-temperature zone +80 DEG C to -40 DEG C, can guarantee stable operation of the self-recovery cascade refrigeration system in -140 DEG C to -40 DEG C, and reduces the risk of overpressure shutdown during startup and the phenomenon of high pressure of the self-recovery cascade subsystem during the cooling process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor special temperature control system in integrated circuit industry, and particularly relates to a self-recovery semiconductor temperature control system with pre-cooling and a control method thereof. BACKGROUND

[0002] In the etching process of a semiconductor wafer, in order to control the etching precision, the temperature in the processing cavity needs to be accurately controlled, and the etching equipment often needs to be configured with a special temperature control device. With the rapid development of the semiconductor manufacturing industry and the increasing complexity of the process, the conventional temperature control device with a temperature range above-70 DEG C cannot meet the development needs of the process. At present, the temperature control device in the low temperature range below-70 DEG C mainly includes two forms: one is the use of a traditional three-stage cascade refrigeration system to meet-80-120 DEG C, which solves the problem of the temperature range. However, since three sets of refrigeration systems are cascaded for cooling, the volume, energy consumption and cost of such a temperature control device are generally high, the control logic is complex, the failure rate is high, the energy efficiency ratio is low, and it cannot be mass-produced. The other is to use a self-cascade subsystem to meet the low temperature range of-40-140 DEG C. Although this solves the problems of the three-stage cascade system, such as complex control logic, high volume, high energy consumption, high cost and low energy efficiency, since multiple mixed working fluids are used for refrigeration, the low-boiling-point component in the mixed working fluid will generate high pressure when the condensing temperature is high. The instantaneous start of the system will cause the load of the compressor to increase and the system to crash. In addition, the pressure of the conventional self-cascade subsystem is generally high during the cooling process, which reduces the service life of the system components and makes the system relatively less reliable. SUMMARY

[0003] The present application provides a self-cascade semiconductor temperature control system with pre-cooling and a control method thereof, which solves the defects of the prior art, such as the complexity of the composition of the ultra-low temperature control system, high energy consumption and poor stability, and realizes the application range of the self-cascade refrigeration system. The self-cascade refrigeration system can stably operate in the high temperature range of +80 DEG C to-40 DEG C, and can also stably operate in the range of-140 DEG C to-40 DEG C, thereby reducing the risk of overpressure and system crash during start-up and the phenomenon of high pressure of the self-cascade subsystem during the cooling process.

[0004] The present application provides a self-cascade semiconductor temperature control system with pre-cooling, comprising:

[0005] A circulating liquid subsystem is connected with a main device, and is used to provide the main device with cooled circulating liquid.

[0006] A pre-cooling subsystem comprises a first evaporator and a pre-cooling compressor, and the first evaporator and the pre-cooling compressor are connected. The pre-cooling subsystem is connected with the circulating liquid subsystem through the first evaporator.

[0007] The self-lifting subsystem comprises a self-lifting compressor, a second evaporator and a condensing evaporator, the self-lifting compressor is connected with the condensing evaporator and the second evaporator, the self-lifting subsystem is connected with the circulating liquid subsystem through the second evaporator, and the self-lifting subsystem is connected with the pre-cooling subsystem through the condensing evaporator.

[0008] According to the self-lifting semiconductor temperature control system with pre-cooling provided by the application, the self-lifting subsystem comprises a condensing separator and a first refrigeration circuit and a second refrigeration circuit, the first refrigeration circuit is connected between the condensing evaporator and the condensing separator, and the second refrigeration circuit is connected between the second evaporator and the condensing separator.

[0009] According to the self-lifting semiconductor temperature control system with pre-cooling provided by the application, the circulating liquid subsystem comprises a first circulating branch and a second circulating branch, the first circulating branch is connected with the first evaporator, the second circulating branch is connected with the second evaporator, the first circulating branch and the second circulating branch are connected in parallel through a first three-way valve and a second three-way valve, and the first circulating branch and the second circulating branch are connected with the main equipment.

[0010] According to the self-lifting semiconductor temperature control system with pre-cooling provided by the application, the pre-cooling subsystem comprises a condenser, a first pre-cooling circuit and a second pre-cooling circuit, the condenser is connected to the front end of the pre-cooling compressor, the first pre-cooling circuit is connected between the condenser, the first evaporator and the pre-cooling compressor, and the second pre-cooling circuit is connected between the condensing evaporator and the condenser.

[0011] According to the self-lifting semiconductor temperature control system with pre-cooling provided by the application, the pre-cooling subsystem further comprises a first cold spray branch, the first cold spray branch is connected between the rear end of the pre-cooling compressor and the front end of the condenser, a first cold spray electromagnetic valve and a cold spray thermal expansion valve are arranged on the first cold spray branch, a pre-cooling exhaust temperature sensor is arranged at the rear end of the pre-cooling compressor, when the pre-cooling exhaust temperature sensor exceeds a set threshold, the first cold spray electromagnetic valve is opened, and the opening degree of the cold spray thermal expansion valve is controlled in real time according to the exhaust temperature measured by the pre-cooling exhaust temperature sensor.

[0012] According to the self-lifting semiconductor temperature control system with pre-cooling provided by the application, a first refrigeration electronic pulse valve and a first refrigeration thermal expansion valve are arranged on the first pre-cooling circuit, the first refrigeration electronic pulse valve is used to allow the refrigerant to flow from the condenser to the first evaporator, and the first refrigeration thermal expansion valve adjusts the opening degree thereof according to the superheat degree of the first evaporator, so as to adjust the real-time flow to the first evaporator.

[0013] The self-recovering semiconductor temperature control system with precooling provided by the application further comprises a second cold spray branch connected between the self-recovering compressor and the condensation separator, and the second cold spray branch is provided with a second cold spray electromagnetic valve and a first capillary tube.

[0014] When the self-recovering exhaust temperature sensor monitors that the exhaust temperature exceeds the preset value Tb, the second cold spray electromagnetic valve is opened to perform throttling and cooling through the first capillary tube.

[0015] When the self-recovering exhaust temperature sensor monitors that the exhaust temperature is lower than the preset value Tb, the second cold spray electromagnetic valve is closed after a delay of ns.

[0016] The self-recovering semiconductor temperature control system with precooling provided by the application further comprises a gas storage branch connected between the self-recovering compressor and the condensation separator, and the gas storage branch is provided with a gas storage tank, an exhaust valve and an inlet valve.

[0017] When the self-recovering exhaust pressure sensor monitors that the exhaust pressure exceeds the set value Pv1 during the throttling and cooling through the first capillary tube, the inlet valve is opened to perform pressure relief.

[0018] When the self-recovering exhaust pressure sensor monitors that the exhaust pressure is lower than the set value Pv1, the inlet valve is closed.

[0019] When the liquid supply temperature sensor monitors that the real-time value is lower than -40℃, the exhaust valve is opened.

[0020] The second refrigeration circuit of the self-recovering semiconductor temperature control system with precooling provided by the application is provided with a third refrigeration electronic pulse valve and a capillary branch connected to both ends of the third refrigeration electronic pulse valve, and the capillary branch is provided with a second capillary tube.

[0021] When the liquid supply temperature sensor monitors that the real-time value is lower than -80℃, the third refrigeration electronic pulse valve is closed to perform throttling refrigeration through the capillary branch.

[0022] The application further provides a control method of the self-recovering semiconductor temperature control system with precooling, which is applied to the self-recovering semiconductor temperature control system with precooling as described above, and the control method comprises the following steps.

[0023] The temperature threshold preset by the main device is judged by the temperature control device PLC receiving the instruction of the main device;

[0024] When the temperature threshold preset by the main device is SV≥-40℃, it is determined that only the precooling subsystem is running.

[0025] When the temperature threshold preset by the main device is -140℃≤SV<-40℃, it is determined that the precooling subsystem and the auto-cascade subsystem are running simultaneously, wherein the precooling compressor is started first, and when the reading of the exhaust pressure sensor reaches the preset value, the auto-cascade compressor is started.

[0026] The self-cascade semiconductor temperature control system with precooling provided by the application can independently run in a high temperature zone through the precooling subsystem, and the first evaporator is connected with the circulating liquid subsystem, which effectively pre-cools the circulating liquid, thereby creating a more stable working environment for the auto-cascade subsystem. This reduces the pressure fluctuation caused by the direct evaporation of refrigerant in the high temperature zone, and ensures the stable operation of the system in the high temperature zone. The auto-cascade subsystem is connected with the circulating liquid subsystem through the second evaporator, and connected with the precooling subsystem through the condenser evaporator, forming an efficient refrigeration cycle. The auto-cascade subsystem can still run stably at extremely low temperature, because the precooling subsystem has reduced the temperature of the refrigerant, reducing the refrigeration load and pressure at extremely low temperature. The precooling effect of the precooling subsystem can reduce the instantaneous evaporation of the refrigerant when the auto-cascade system starts, thereby reducing the pressure peak value when starting, reducing the risk of sudden increase of compressor load, and avoiding system downtime due to overpressure. Since the precooling subsystem has reduced the temperature of the refrigerant in advance, the required refrigeration capacity of the auto-cascade subsystem during the cooling process is reduced, so the overall pressure of the system is reduced. It ensures that the system pressure remains within a safe range during the cooling process, thereby improving the reliability of the system and the service life of the components. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0028] Figure 1 It is the connection diagram of the self-cascade semiconductor temperature control system with precooling provided by the application.

[0029] Reference signs:

[0030] 1, pre-cooling compressor; 2, pre-cooling exhaust temperature sensor; 3, pre-cooling oil separator; 4, first check valve; 5, condenser; 6, condensing pressure regulating valve; 7, pre-cooling dry filter; 8, first cold spray solenoid valve; 9, cold spray thermal expansion valve; 10, first refrigeration electronic pulse valve; 11, first refrigeration thermal expansion valve; 12, second refrigeration electronic pulse valve; 13, second refrigeration thermal expansion valve; 14, first evaporator; 15, second check valve; 16, pre-cooling hot gas electronic expansion valve; 17, suction pressure sensor;

[0031] 21, auto-cascade compressor; 22, auto-cascade oil separator; 23, auto-cascade exhaust pressure sensor; 24, auto-cascade exhaust temperature sensor; 25, condensing evaporator; 26, auto-cascade dry filter; 27, partial condensing separator; 28, regenerator; 29, third refrigeration electronic pulse valve; 30, fourth capillary tube; 31, second capillary tube; 32, third capillary tube; 33, second cold spray solenoid valve; 34, first capillary tube; 35, exhaust valve; 36, third check valve; 37, intake valve; 38, gas storage tank; 39, auto-cascade hot gas electronic expansion valve;

[0032] 40, flow meter; 41, first three-way valve 1; 42, second three-way valve 2; 43, circulating pump; 44, heater; 45, water tank; 46, supply water temperature sensor; 47, supply water pressure sensor; 48, second evaporator; 49, main device; 50, return port temperature sensor. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be further described below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0034] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0036] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] The following is combined Figure 1 The present invention provides a detailed description of the pre-cooled self-cascading semiconductor temperature control system and its control method through specific embodiments and application scenarios.

[0039] In embodiments of the present invention, such as Figure 1As shown, the self-recovering cascade semiconductor temperature control system with pre-cooling includes a circulating liquid subsystem, a pre-cooling subsystem, and a self-recovering cascade subsystem. The circulating liquid subsystem is connected with the main equipment 49, and is configured to provide the main equipment 49 with cooled circulating liquid. The pre-cooling subsystem includes a first evaporator 14 and a pre-cooling compressor 1. The first evaporator 14 is connected with the pre-cooling compressor 1. The pre-cooling subsystem is connected with the circulating liquid subsystem through the first evaporator 14. The self-recovering cascade subsystem includes a self-recovering cascade compressor 21, a second evaporator 48, and a condensing evaporator 25. The self-recovering cascade compressor 21 is connected with the condensing evaporator 25 and the second evaporator 48. The self-recovering cascade subsystem is connected with the circulating liquid subsystem through the second evaporator 48, and is connected with the pre-cooling subsystem through the condensing evaporator 25.

[0040] The circulating liquid subsystem is directly connected with the main equipment 49 (a semiconductor etching device), and is configured to transfer cooling energy and ensure temperature stability of the main equipment 49.

[0041] The circulating liquid circulates in the system, is cooled by the refrigeration subsystem, flows to the main equipment 49, absorbs heat generated by the main equipment 49, and then returns to the refrigeration system to continue cooling, thereby forming a closed cycle and maintaining constant temperature of the main equipment 49.

[0042] The pre-cooling subsystem includes the first evaporator 14 and the pre-cooling compressor 1. The pre-cooling subsystem is mainly configured to pre-cool the circulating liquid in a higher temperature range, and reduce the refrigeration burden of the self-recovering cascade subsystem.

[0043] The first evaporator 14 is connected with the pre-cooling compressor 1. The pre-cooling compressor 1 drives the refrigerant to evaporate in the first evaporator 14 to absorb heat, thereby absorbing heat of the circulating liquid and achieving pre-cooling effect.

[0044] The first evaporator 14 is connected with the circulating liquid subsystem. The first evaporator 14 serves as an interface between the pre-cooling subsystem and the circulating liquid subsystem, and completes heat exchange.

[0045] The self-recovering cascade subsystem includes the self-recovering cascade compressor 21, the second evaporator 48, and the condensing evaporator 25. The self-recovering cascade subsystem is responsible for refrigeration in a lower temperature range. The design allows the use of multi-component mixed working medium to achieve refrigeration in a wider temperature range.

[0046] The self-recovering cascade compressor 21 is connected with the condensing evaporator 25 and the second evaporator 48. The cascade compressor is a power source of the system. It compresses the refrigerant, releases heat in the condensing evaporator 25 to condense the refrigerant, and then absorbs heat in the second evaporator 48 to evaporate the refrigerant, thereby achieving a refrigeration cycle.

[0047] The second evaporator 48 is connected with the circulating liquid subsystem. The second evaporator 48 is a key component for connecting the self-recovering cascade subsystem with the circulating liquid subsystem. The second evaporator 48 absorbs heat in the circulating liquid by evaporation of the refrigerant to reduce the temperature of the circulating liquid.

[0048] The condensing evaporator 25 is connected with the pre-cooling subsystem, and the condensing evaporator 25 simultaneously serves as the condenser 5 of the self-recovery subsystem and the evaporator of the pre-cooling subsystem, so that the energy exchange and cooperation between the two subsystems are realized. The refrigerant in the self-recovery subsystem releases heat in the condensing evaporator 25 and is cooled by the pre-cooling subsystem, thereby improving the refrigeration efficiency and stability of the entire system.

[0049] The pre-cooling subsystem provided in the application can independently operate in a high-temperature zone, and the first evaporator 14 is connected with the circulating liquid subsystem, so that the circulating liquid is effectively pre-cooled, thereby creating a more stable working environment for the self-recovery subsystem. This reduces the pressure fluctuation caused by direct evaporation of the refrigerant in the high-temperature zone, and ensures the stable operation of the system in the high-temperature zone. The self-recovery subsystem stably operates in the temperature range of-140℃ to-40℃, and is connected with the circulating liquid subsystem through the second evaporator 48 and connected with the pre-cooling subsystem through the condensing evaporator 25, thereby forming an efficient refrigeration cycle. The self-recovery subsystem can still stably operate at an extremely low temperature, because the pre-cooling subsystem has reduced the temperature of the refrigerant and reduced the refrigeration load and pressure at the extremely low temperature. The pre-cooling effect of the pre-cooling subsystem can reduce the instantaneous evaporation of the refrigerant when the self-recovery system starts, thereby reducing the pressure peak value when starting and reducing the risk of sudden increase of the compressor load, and avoiding system shutdown due to overpressure. Since the pre-cooling subsystem has reduced the temperature of the refrigerant in advance, the overall pressure of the system is reduced. This ensures that the system pressure is kept within a safe range during the cooling process, thereby improving the reliability of the system and the service life of the components.

[0050] Reference Figure 1 According to the self-recovery semiconductor temperature control system with pre-cooling provided in the application, the self-recovery subsystem includes a condensing separator 27 and a first refrigeration circuit and a second refrigeration circuit, the first refrigeration circuit is connected between the condensing evaporator 25 and the condensing separator 27, and the second refrigeration circuit is connected between the second evaporator 48 and the condensing separator 27.

[0051] It can be understood that the condensing separator 27 is used to separate different components in the multi-component mixed working medium. In the refrigeration cycle, different components of the refrigerant are separated and condensed at different temperatures and pressures, so as to realize efficient heat exchange and improve the refrigeration efficiency. The condensing separator 27 makes the high-boiling-point component and the low-boiling-point component play a role at different stages, the high-boiling-point component is condensed at a higher temperature, and the low-boiling-point component is evaporated at a lower temperature, so that the refrigeration performance of the entire system is optimized, and the refrigeration temperature range is widened.

[0052] The first refrigeration circuit is connected between the condensing evaporator 25 and the partial condensation separator 27. The first refrigeration circuit is provided to handle the high-boiling components in the multi-component mixed working fluid. In this circuit, the refrigerant releases heat (condenses) in the condensing evaporator 25 and then flows through the partial condensation separator 27, where the high-boiling components are separated and prepared for the next cycle. The first refrigeration circuit ensures the refrigeration efficiency of the system in the higher temperature range, and through the action of the partial condensation separator 27, ensures the effective use of different components and stable operation of the system.

[0053] The second refrigeration circuit is connected between the second evaporator 48 and the partial condensation separator 27. The second refrigeration circuit mainly handles the low-boiling components in the multi-component mixed working fluid. In this circuit, the refrigerant absorbs heat (evaporates) in the second evaporator 48 and then flows to the partial condensation separator 27, where the low-boiling components are separated and recycled. The second refrigeration circuit is responsible for providing refrigeration capacity in the lower temperature range, and through the separation action of the partial condensation separator 27, ensures the effective evaporation of low-boiling components at low temperature, thereby realizing refrigeration in a wider temperature range.

[0054] Referring to Figure 1 According to the self-recovery semiconductor temperature control system with pre-cooling provided by the present application, the circulating liquid subsystem includes a first circulating branch and a second circulating branch. The first circulating branch is connected with the first evaporator 14, and the second circulating branch is in communication with the second evaporator 48. The first circulating branch and the second circulating branch are connected in parallel through a first three-way valve and a second three-way valve, and are in communication with the main equipment 49.

[0055] It can be understood that the first circulating branch is directly connected with the first evaporator 14 of the pre-cooling subsystem, and its main function is to provide preliminary cooling for the circulating liquid in the pre-cooling stage. The second circulating branch is connected with the second evaporator 48 of the self-recovery subsystem, and is responsible for further reducing the temperature of the circulating liquid to meet the refrigeration requirements in the lower temperature range. The second circulating branch enables the circulating liquid to achieve deeper cooling in the self-recovery subsystem, which is crucial to meet the ultra-low temperature requirements in the semiconductor wafer etching process.

[0056] The first three-way valve and the second three-way valve are provided to allow the first circulating branch and the second circulating branch to be connected in parallel in the system, which can flexibly control the flow direction and flow rate of the circulating liquid. The parallel configuration of the three-way valves provides multiple operating modes, which can adjust the cooling path of the circulating liquid according to the actual temperature requirements of the main equipment 49, thereby optimizing the refrigeration performance and energy efficiency of the system.

[0057] The first circulation branch and the second circulation branch are communicated with the main device 49 through the three-way valve, which ensures that the circulating liquid can effectively absorb heat from the main device 49 and be cooled in the refrigeration subsystem, and then be circulated into the main device 49 again. The continuous flow of the circulating liquid between the main device 49 and the refrigeration system is realized, and the constant temperature control of the main device 49 is maintained.

[0058] With reference to Figure 1 According to the self-recovery cascade semiconductor temperature control system with pre-cooling provided by the application, the pre-cooling subsystem comprises a condenser 5, a first pre-cooling circuit and a second pre-cooling circuit. The condenser 5 is connected to the front end of a pre-cooling compressor 1. The first pre-cooling circuit is connected between the condenser 5 and a first evaporator 14 and the pre-cooling compressor 1. The second pre-cooling circuit is connected between a condensing evaporator 25 and the condenser 5.

[0059] It can be understood that the condenser 5 is located before the pre-cooling compressor 1. Its function is to release heat from the refrigerant before the compressor compresses, so as to realize the conversion of the gaseous refrigerant into liquid. The condenser 5 cools the refrigerant to condense it, thereby improving the refrigeration efficiency of the system. At the same time, it also plays a role in protecting the compressor, avoiding the compressor from sucking in overheated steam, and prolonging the service life of the compressor.

[0060] The first pre-cooling circuit is connected between the condenser 5 and the first evaporator 14 and the pre-cooling compressor 1. The first pre-cooling circuit comprises the condenser 5, the first evaporator 14 and the pre-cooling compressor 1, and forms a closed circulation path. The first pre-cooling circuit is responsible for quickly reducing the temperature of the circulating liquid when the system starts, absorbing the heat of the circulating liquid through the first evaporator 14, then compressing through the pre-cooling compressor 1, and finally releasing heat in the condenser 5 to complete a pre-cooling cycle.

[0061] The second pre-cooling circuit is connected between the condensing evaporator 25 and the condenser 5. The second pre-cooling circuit connects the condensing evaporator 25 in the self-recovery cascade subsystem and the condenser 5 in the pre-cooling subsystem, and forms an additional heat exchange path. The function of the second pre-cooling circuit is to pre-cool the self-recovery cascade subsystem before the self-recovery cascade subsystem runs, to prevent the risk of sudden load increase of the self-recovery cascade compressor 21 in the self-recovery cascade subsystem, and to avoid system downtime due to overpressure.

[0062] With reference to Figure 1, according to the present application, a self-recovery semiconductor temperature control system with pre-cooling is provided, the pre-cooling subsystem further comprises a first cold spray branch, the first cold spray branch is connected to the rear end of the pre-cooling compressor 1 and the front end of the condenser 5, the first cold spray branch is provided with a first cold spray solenoid valve 8 and a cold spray thermal expansion valve 9, the rear end of the pre-cooling compressor 1 is provided with a pre-cooling exhaust temperature sensor 2, when the pre-cooling exhaust temperature sensor 2 exceeds the set threshold, the first cold spray solenoid valve 8 is opened, at the same time, the exhaust temperature measured by the pre-cooling exhaust temperature sensor 2 is used to control the opening of the cold spray thermal expansion valve 9 in real time.

[0063] It can be understood that the first cold spray branch is connected to the rear end of the pre-cooling compressor 1 and the front end of the condenser 5, the first cold spray branch is located between the pre-cooling compressor 1 and the condenser 5, its main function is to cool the high-temperature gas discharged by the compressor when necessary, to protect the system and improve the efficiency. By setting the cold spray branch between the compressor and the condenser 5, the exhaust temperature of the compressor can be effectively controlled to prevent overheating, thereby protecting the compressor and ensuring stable operation of the system.

[0064] The first cold spray solenoid valve 8 is located on the first cold spray branch, and the first cold spray solenoid valve 8 is used to control the opening and closing of the cold spray branch. When the pre-cooling exhaust temperature sensor 2 detects that the exhaust temperature exceeds the set threshold, the first cold spray solenoid valve 8 will be opened, allowing part of the refrigerant to pass through the cold spray branch for cooling, thereby reducing the exhaust temperature.

[0065] The cold spray thermal expansion valve 9 is located on the first cold spray branch, and the cold spray thermal expansion valve 9 is used to adjust the flow of refrigerant through the cold spray branch. According to the exhaust temperature measured by the pre-cooling exhaust temperature sensor 2, the opening of the cold spray thermal expansion valve 9 is controlled in real time to accurately control the cooling amount. In this way, it can ensure that the exhaust temperature remains within a suitable range, avoiding overheating of the compressor, while optimizing the energy efficiency of the system.

[0066] The pre-cooling exhaust temperature sensor 2 is located at the rear end of the pre-cooling compressor 1, and the pre-cooling exhaust temperature sensor 2 is used to monitor the exhaust temperature of the compressor. When the exhaust temperature exceeds the set threshold, the sensor will trigger the opening of the first cold spray solenoid valve 8, and provide real-time exhaust temperature data to the cold spray thermal expansion valve 9 to adjust its opening. In this way, accurate control of the exhaust temperature of the compressor can be achieved, protecting the compressor and improving the overall performance of the system.

[0067] Referring to Figure 1 , according to the present application, a self-recovery semiconductor temperature control system with pre-cooling is provided, the first pre-cooling circuit is provided with a first refrigeration electronic pulse valve and a first refrigeration thermal expansion valve 11, the first refrigeration electronic pulse valve is used to allow refrigerant to flow from the condenser 5 to the first evaporator 14, and the first refrigeration thermal expansion valve 11 adjusts its opening according to the superheat of the first evaporator 14 to adjust the real-time flow to the first evaporator 14.

[0068] It can be understood that the first refrigeration electronic pulse valve is installed on the first pre-cooling circuit, and the first refrigeration electronic pulse valve is installed on the pipeline from the condenser 5 to the first evaporator 14. The main function of the valve is to control the flow of refrigerant from the condenser 5 into the first evaporator 14. By opening and closing, it can accurately allow the refrigerant to flow into the first evaporator 14, thereby starting the process of the refrigeration cycle. The fast response characteristics of the electronic pulse valve help to achieve accurate flow control.

[0069] The first refrigeration thermal expansion valve 11 is located on the first pre-cooling circuit, and the first refrigeration thermal expansion valve 11 is usually located in front of the first evaporator 14, which is used to adjust the flow of refrigerant into the evaporator. According to the superheat degree of the first evaporator 14 (i.e. the degree to which the refrigerant temperature at the outlet of the evaporator exceeds its saturated evaporation temperature), the thermal expansion valve automatically adjusts its opening degree to control the real-time flow to the first evaporator 14. This can ensure that the evaporator works in the best state and avoid overheat or overcooling. By adjusting the flow, the thermal expansion valve helps to maintain the high efficiency of the evaporator and prevent the evaporator from causing refrigeration efficiency to decrease due to overheating or causing refrigerant liquid strike problems due to overcooling.

[0070] Referring to Figure 1 According to the self-recovery semiconductor temperature control system with pre-cooling provided by the application, the second cold spray branch is connected between the self-recovery compressor 21 and the condensation separator 27, the second cold spray electromagnetic valve 33 and the first capillary tube 34 are arranged on the second cold spray branch, and the self-recovery exhaust temperature sensor 24 and the self-recovery exhaust pressure sensor 23 are arranged between the self-recovery compressor 21 and the condensation evaporator 25; when the self-recovery exhaust temperature sensor 24 monitors that the exhaust temperature exceeds the preset value Tb, the second cold spray electromagnetic valve 33 is opened to throttle and cool through the first capillary tube 34; when the self-recovery exhaust temperature sensor 24 monitors that the exhaust temperature is lower than the preset value Tb, the delay ns is closed.

[0071] It can be understood that the second cold spray branch is connected between the self-recovery compressor 21 and the condensation separator 27, and the second cold spray branch is located between the self-recovery compressor 21 and the condensation separator 27. Its function is to cool the high-temperature gas discharged by the compressor when necessary, so as to protect the compressor and improve the system efficiency. By arranging the cold spray branch between the compressor and the condensation separator 27, the exhaust temperature of the compressor can be effectively controlled to prevent overheating and ensure the stable operation of the system.

[0072] The second cold spray electromagnetic valve 33 is located on the second cold spray branch, and is used to control the opening and closing of the cold spray branch. When the self-recovery cascade exhaust temperature sensor 24 detects that the exhaust temperature exceeds the preset value Tb, the second cold spray electromagnetic valve 33 is opened to allow the refrigerant to pass through the first capillary tube 34 for throttling and cooling, thereby reducing the exhaust temperature and protecting the compressor.

[0073] The first capillary tube 34 is located on the second cold spray branch, and is used to achieve the effect of throttling and cooling. When the second cold spray electromagnetic valve 33 is opened, the refrigerant passes through the first capillary tube 34 for throttling, which causes the temperature and pressure of the refrigerant to decrease, thereby achieving the effect of cooling.

[0074] The self-recovery cascade exhaust temperature sensor 24 is located between the self-recovery cascade compressor 21 and the condenser evaporator 25, and is used to monitor the exhaust temperature of the compressor. It monitors the exhaust temperature in real time and triggers the opening of the second cold spray electromagnetic valve 33 when the exhaust temperature exceeds the preset value Tb (which can be set) to perform cooling. When the exhaust temperature is lower than the preset value Tb (which can be set), the system will delay n (which can be set) seconds to close the second cold spray electromagnetic valve 33 to avoid unnecessary energy consumption and system oscillation.

[0075] The self-recovery cascade exhaust pressure sensor 23 is located between the self-recovery cascade compressor 21 and the condenser evaporator 25, and is used to monitor the exhaust pressure of the compressor. The data of the exhaust pressure can be provided for further optimization of the control and protection functions of the system.

[0076] Referring to Figure 1 , according to the self-recovery cascade semiconductor temperature control system with pre-cooling provided by the present application, the self-recovery cascade further includes a gas storage branch connected between the self-recovery cascade compressor 21 and the condenser evaporator 25, and the gas storage branch is provided with a gas storage tank 38, an exhaust valve 35 and an inlet valve 37. The inlet valve 37 is connected between the gas storage tank 38 and the condenser evaporator 25, and the exhaust valve 35 is connected between the gas storage tank 38 and the self-recovery cascade compressor 21. The self-recovery cascade compressor 21 and the condenser evaporator 25 are further provided with a self-recovery cascade exhaust pressure sensor 23, and the circulating liquid subsystem is provided with a liquid supply temperature sensor 46. During the process of throttling and cooling through the first capillary tube, when the self-recovery cascade exhaust pressure sensor 23 detects that the exhaust pressure exceeds the set value Pv1, the inlet valve 37 is opened for pressure relief; when the self-recovery cascade exhaust pressure sensor 23 detects that the exhaust pressure is lower than the set value Pv1, the inlet valve 37 is closed; and when the liquid supply temperature sensor 46 detects that the real-time value decreases to below -40℃, the exhaust valve 35 is opened.

[0077] It can be understood that the gas storage branch is connected between the auto-cascade compressor 21 and the condenser-evaporator 27, and the gas storage branch serves to provide an additional pressure management and adjustment mechanism to optimize the performance and reliability of the system. The gas storage branch balances the pressure fluctuations in the system through the gas storage tank 38 to prevent the compressor from being damaged due to excessive pressure and to maintain stable operation of the system.

[0078] The gas storage tank 38 is located on the gas storage branch, and the gas storage tank 38 is used to store a certain amount of refrigerant gas as a pressure buffer. The gas storage tank 38 can absorb pressure peaks in the system, reduce pressure fluctuations, and protect the compressor from excessive pressure.

[0079] The gas inlet valve 37 is connected between the gas storage tank 38 and the condenser-evaporator 25, and the gas inlet valve 37 is used to control the flow of refrigerant gas into the gas storage tank 38. When the auto-cascade exhaust pressure sensor 23 monitors that the exhaust pressure exceeds the set value Pv1, the gas inlet valve 37 opens to allow refrigerant gas to enter the gas storage tank 38, thereby reducing the pressure of the system and avoiding overpressure.

[0080] The gas outlet valve 35 is connected between the gas storage tank 38 and the auto-cascade compressor 21, and the gas outlet valve 35 is used to release the gas in the gas storage tank 38 to adjust the system pressure. When the liquid supply temperature sensor 46 monitors that the temperature of the circulating liquid drops below -40℃ (settable), the gas outlet valve 35 opens to release the gas in the gas storage tank 38 to prevent high pressure in the system and to achieve pressure reduction by releasing the low-boiling-point components in the mixed working medium to protect the system.

[0081] The auto-cascade exhaust pressure sensor 23 is located between the auto-cascade compressor 21 and the condenser-evaporator 25, and the auto-cascade exhaust pressure sensor 23 is used to monitor the exhaust pressure of the compressor. It monitors the exhaust pressure in real time and triggers the opening of the gas inlet valve 37 when the pressure exceeds the set value Pv1, and closes the gas inlet valve 37 after the pressure decreases to maintain the system pressure within a safe range.

[0082] The liquid supply temperature sensor 46 is located on the circulating liquid subsystem, and the liquid supply temperature sensor 46 is used to monitor the temperature of the circulating liquid. It monitors the temperature of the circulating liquid in real time and triggers the opening of the gas outlet valve 35 when the temperature drops below -40℃ to prevent high pressure in the system and ensure safe operation of the system.

[0083] Referring to Figure 1 According to the auto-cascade semiconductor temperature control system with pre-cooling provided by the present application, the second refrigeration circuit is provided with a third refrigeration electronic pulse valve 29 and a capillary branch connected to both ends of the third refrigeration electronic pulse valve 29, and the capillary branch is provided with a second capillary tube 31; when the real-time value monitored by the liquid supply temperature sensor 46 is lower than -80℃, the third refrigeration electronic pulse valve 29 is closed, and throttling refrigeration is performed through the capillary branch.

[0084] It can be understood that the third refrigeration electronic pulse valve 29 is located on the second refrigeration circuit, and the third refrigeration electronic pulse valve 29 is used to control the flow of refrigerant in the second refrigeration circuit. The valve can be quickly opened or closed according to the needs of the system, accurately control the flow of refrigerant, and thus adjust the refrigeration capacity.

[0085] The capillary branch is connected to both ends of the third refrigeration electronic pulse valve 29, and the capillary branch is a small bypass pipeline connected to one side of the main refrigeration circuit for specific flow control. The capillary branch provides an additional control path, so that the refrigeration capacity can be adjusted by throttling under certain conditions.

[0086] The second capillary tube 31 is located on the capillary branch, and the second capillary tube 31 is a small pipeline for realizing the throttling effect, that is, by reducing the cross section of the pipeline to increase the flow rate of the refrigerant, thereby reducing its pressure and temperature. When the liquid supply temperature sensor 46 monitors that the real-time temperature is lower than -80℃, the second capillary tube 31 reduces the temperature of the refrigerant by throttling, while reducing the refrigeration capacity, to prevent the circulating liquid from being supercooled.

[0087] In a specific embodiment, the precooling subsystem includes a precooling compressor 1, a precooling discharge temperature sensor 2, a precooling oil separator 3, a first one-way valve 4, a condenser 5, a condensing pressure regulating valve 6, a precooling dry filter 7, a first cold spray electromagnetic valve 8, a cold spray thermal expansion valve 9, a first refrigeration electronic pulse valve 10, a first refrigeration thermal expansion valve 11, a second refrigeration electronic pulse valve 12, a second refrigeration thermal expansion valve 13, a first evaporator 14, a second one-way valve 15, a precooling hot gas electronic expansion valve 16, and a suction pressure sensor 17.

[0088] The auto cascade subsystem includes an auto cascade compressor 21, an auto cascade oil separator 22, an auto cascade discharge pressure sensor 23, an auto cascade discharge temperature sensor 24, a condensing evaporator 25, an auto cascade dry filter 26, a split condenser 27, a regenerator 28, a third refrigeration electronic pulse valve 29, a fourth capillary tube 30, a second capillary tube 31, a third capillary tube 32, a second cold spray electromagnetic valve 33, a first capillary tube 34, a discharge valve 35, a third one-way valve 36, an intake valve 37, a gas tank 38, and an auto cascade hot gas electronic expansion valve 39,

[0089] The circulating liquid subsystem includes a flow meter 40, a first three-way valve, a second three-way valve, a circulating pump 43, a heater 44, a water tank 45, a liquid supply temperature sensor 46, a liquid supply pressure sensor 47, a second evaporator 48, a main device 49, and a return temperature sensor 50.

[0090] When the temperature control device accepts the main device 49 instruction, SV≥-40℃, only the pre-cooling subsystem runs; At this time, the pre-cooling compressor 1 starts, the second refrigeration electronic pulse valve 12 opens, and the second refrigeration thermal electric expansion valve 13 controls in real time according to the superheat of the first evaporator 14 to prevent system backflow. The second refrigeration electronic pulse valve 12 is preset to A%, the preset unloaded suction pressure value is P1, the maximum loaded suction pressure value is P2, and the pulse period T, so the opening time Ta=A%*T. When the pressure is low, the pre-cooling hot gas electronic expansion valve 16 performs preset pressure value P1 correction adjustment to meet the stability of the system pressure. To meet the running conditions of loaded and unloaded at the same time, the valve opening correction coefficient X is set. When the main device 49 runs unloaded, the return temperature sensor 50 monitoring value T1 is approximately equal to the supply liquid temperature sensor 46 monitoring value T2. When the main device 49 runs loaded, T1 and T2 have a difference ΔT. When ΔT=0, the correction coefficient is 1 (according to the actual device debugging setting), and when ΔT is the maximum load, the correction coefficient is 0.5 (according to the actual device debugging setting), that is, A%*1 when the maximum load, and A%*0.5 when running unloaded. Between the two, the correction coefficient corresponds linearly within the interval of P1 and P2.

[0091] When the temperature control device accepts the main device 49 instruction, -140℃≤SV<-40℃, the temperature control device determines that the double system runs; At this time, the pre-cooling subsystem is started first, the pre-cooling compressor 1 starts, the first refrigeration electric pulse valve 10 opens, and the first refrigeration thermal expansion valve 11 controls in real time according to the superheat of the first evaporator 14 to prevent system backflow. The first refrigeration electric pulse valve 10 is preset to B%, the preset suction pressure value is P3, and the pre-cooling hot gas electronic expansion valve 16 performs preset pressure value P3 correction adjustment to meet the stable operation of the pre-cooling subsystem. When the exhaust pressure sensor of the self-lifting system detects that the pressure value Pz<11bar (which can be set), the self-lifting compressor 21 runs to avoid the starting overpressure of the self-lifting system and improve the stability of the system. The control logic of the self-lifting hot gas electronic expansion valve 39 and the third refrigeration electronic pulse valve 29 refers to the corresponding valve control logic of the pre-cooling subsystem, and the preset opening and the correction coefficient are set according to the system. Below -80℃, the self-lifting system refrigeration surplus is relatively small, and the circulating liquid system heater 44 is relied on for correction adjustment.

[0092] When SV≥-40℃, the pre-cooling compressor 1 starts after a delay of 10s (which can be set), the circulating liquid pump is started, and the A-B of the first three-way valve and the second three-way valve is conducted. When SV<-40℃, the self-lifting compressor 21 starts after a delay of 10s (which can be set), the circulating liquid pump is started, and the A-C of the first three-way valve and the second three-way valve is conducted. According to the set flow and pressure, the frequency converter is adjusted to meet the flow and pressure requirements of the main device 49. Avoiding the temperature rise caused by the water pump heat dissipation before the self-lifting compressor 21 starts.

[0093] When the pre-cooling exhaust temperature sensor 2 monitors that the exhaust temperature exceeds Ta, the first cold spray solenoid valve 8 is opened, and the cold spray thermal expansion valve 9 is adjusted in real time according to the suction temperature to avoid compressor failure caused by liquid injection.

[0094] When the self-recovery cascade exhaust temperature sensor 24 monitors that the exhaust temperature exceeds Tb, the second cold spray solenoid valve 33 is opened, and the first capillary 34 is throttled to reduce the temperature. After falling below Tb, the delay of 5s (which can be set) is closed; during the cooling process, when the self-recovery cascade exhaust pressure sensor 23 monitors that the exhaust pressure exceeds the set value Pv, the inlet valve 37 is opened to release pressure, and when it falls below Pv1, it is closed. When the liquid supply temperature sensor 46 monitors that the real-time value falls below -40℃, the exhaust valve 35 is opened to avoid overpressure shutdown caused by a large amount of multi-component mixed working medium entering the system. When the liquid supply temperature sensor 46 monitors that the real-time value is lower than -80℃, the third refrigeration electronic pulse valve 29 is closed. Only the second capillary 31 is throttled to reduce the temperature. The split separator 27 is used to separate the multi-component mixed working medium, and the high-boiling component in the mixed working medium is throttled through the third capillary 32 and evaporated in the regenerator 28. The lower-boiling component is condensed into a liquid and then throttled through the third refrigeration electronic pulse valve 29 and the fourth capillary 30 and the second capillary 31 to reduce the temperature. This cycle is repeated. The third single valve 36 is used for overpressure unloading after abnormal shutdown of the system.

[0095] On the other hand, the application also provides a control method of a self-recovery cascade semiconductor temperature control system with pre-cooling, which is applied to the self-recovery cascade semiconductor temperature control system with pre-cooling as described above, and the control method comprises the following steps:

[0096] The temperature control device PLC receives the instruction of the main equipment 49 and judges the temperature threshold value preset by the main equipment 49;

[0097] When the temperature threshold value preset by the main equipment 49 is SV≥-40℃, it is determined that only the pre-cooling subsystem is running.

[0098] When the temperature threshold value preset by the main equipment 49 is -140℃≤SV<-40℃, it is determined that the pre-cooling subsystem and the self-recovery cascade subsystem are running simultaneously, wherein the pre-cooling compressor 1 is started first, and the self-recovery cascade compressor 21 is started after the reading of the exhaust pressure sensor reaches the preset value.

[0099] It can be understood that the programmable logic controller (PLC) is the core control unit of the temperature control system, which receives the temperature control instruction from the main equipment 49 (such as a semiconductor manufacturing equipment).

[0100] The PLC first communicates with the main equipment 49 to obtain the required temperature set value (SV).

[0101] According to the temperature threshold set by the main device 49, the PLC can determine which subsystems need to run and how to adjust these subsystems to achieve the required temperature control.

[0102] The PLC compares the received temperature set value with the preset temperature threshold to determine the operating mode.

[0103] When the temperature threshold preset by the main device 49 is: SV≥-40℃, if the temperature required by the main device 49 is at or above -40℃, only the pre-cooling subsystem needs to run to meet the requirements.

[0104] The PLC controls the pre-cooling subsystem to run alone and closes the auto-cascade subsystem to save energy and improve efficiency.

[0105] When the temperature threshold preset by the main device 49 is: -140℃≤SV<-40℃, when the temperature required by the main device 49 is lower than -40℃ but higher than -140℃, the pre-cooling subsystem and the auto-cascade subsystem need to run simultaneously to achieve a lower temperature.

[0106] The PLC first starts the pre-cooling compressor 1 to start the pre-cooling process.

[0107] When the reading of the exhaust pressure sensor reaches the preset value, indicating that the pre-cooling subsystem has reached a certain pressure level, the PLC starts the auto-cascade compressor 21 at this time.

[0108] In this way, it can ensure smooth transition of the system to a low temperature state, while avoiding damage to the compressor due to pressure imbalance.

[0109] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A self-cascading semiconductor temperature control system with pre-cooling, characterized in that, include: A circulating liquid subsystem is connected to the main equipment and is used to provide the main equipment with cooled circulating liquid; A precooling subsystem, comprising a first evaporator and a precooling compressor, wherein the first evaporator and the precooling compressor are connected, and the precooling subsystem is connected to the circulating liquid subsystem through the first evaporator; The self-cascading subsystem includes a self-cascading compressor, a second evaporator, and a condensing evaporator. The self-cascading compressor is connected to the condensing evaporator and the second evaporator, respectively. The self-cascading subsystem is connected to the circulating liquid subsystem through the second evaporator and to the precooling subsystem through the condensing evaporator. The self-cascaded subsystem includes a condenser separator, a first refrigeration circuit, and a second refrigeration circuit. The first refrigeration circuit is connected between the condenser-evaporator and the condenser separator, and the second refrigeration circuit is connected between the second evaporator and the condenser separator. The precooling subsystem includes a condenser, a first precooling circuit, and a second precooling circuit. The condenser is connected to the front end of the precooling compressor. The first precooling circuit is connected in sequence to the condenser, the first evaporator, and the precooling compressor. The second precooling circuit is connected between the condenser-evaporator and the condenser. The self-cascade subsystem also includes a second cold spray branch, which is connected between the inlet of the self-cascade compressor and the condenser separator. The second cold spray branch is provided with a second cold spray solenoid valve and a first capillary tube. A self-cascade exhaust temperature sensor and a self-cascade exhaust pressure sensor are provided between the self-cascade compressor and the condenser evaporator. When the self-cascading exhaust temperature sensor detects that the second exhaust temperature exceeds the preset value Tb, the second cold injection solenoid valve opens to throttle and cool through the first capillary tube. When the self-cascading exhaust temperature sensor detects that the second exhaust temperature is lower than the preset value Tb, it shuts off after a delay of n seconds. The self-cascade compressor also includes a gas storage branch. One end of the gas storage branch is connected between the inlet of the self-cascade compressor and the condenser separator, and the other end of the gas storage branch is connected between the condenser evaporator and the condenser separator. The gas storage branch is equipped with a gas storage tank, an exhaust valve, and an intake valve. The intake valve is connected between the gas storage tank and the condenser evaporator, and the exhaust valve is connected between the gas storage tank and the self-cascade compressor. A self-cascade exhaust pressure sensor is also provided between the self-cascade compressor and the condenser evaporator. A liquid supply temperature sensor is provided on the circulating liquid subsystem. During the throttling and cooling process through the first capillary tube, when the self-cascading exhaust pressure sensor detects that the exhaust pressure exceeds the set value Pv1, the intake valve opens to release pressure. When the self-cascading exhaust pressure sensor detects that the exhaust pressure is lower than the set value Pv1, the intake valve closes. When the real-time value monitored by the liquid supply temperature sensor drops below -40°C, the exhaust valve opens to release the gas in the gas storage tank. By releasing the low-boiling-point components in the mixed working fluid, the pressure is reduced. The second refrigeration circuit is provided with a third refrigeration electronic pulse valve and a capillary branch connected in parallel to both ends of the third refrigeration electronic pulse valve, and a second capillary tube is provided on the capillary branch; In the first refrigeration circuit, the refrigerant releases heat in the condenser-evaporator and then flows through the fractionation separator. In the second refrigeration circuit, the refrigerant absorbs heat in the second evaporator and then flows to the condenser separator; The second precooling loop connects the condenser-evaporator in the self-cascade subsystem and the condenser in the precooling subsystem, forming an additional heat exchange path. The function of the second precooling loop is to precool the self-cascade subsystem before it is put into operation. The condensation separator is used to separate the multi-component mixed working fluid. The high-boiling-point component in the mixed working fluid is throttled through the third capillary tube and evaporated in the regenerator, while the low-boiling-point component is condensed into a liquid. The low-boiling-point component in the mixed working fluid is then throttled and cooled through the third refrigeration electronic pulse valve, the fourth capillary tube, and the second capillary tube, and so on in a repeated cycle. The first refrigeration circuit is for processing the high-boiling-point components in the multi-component mixed working fluid; the second refrigeration circuit mainly processes the low-boiling-point components in the multi-component mixed working fluid.

2. The self-cascading semiconductor temperature control system with pre-cooling according to claim 1, characterized in that, The circulating liquid subsystem includes a first circulating branch and a second circulating branch. The first circulating branch is connected to the first evaporator, and the second circulating branch is connected to the second evaporator. The first circulating branch and the second circulating branch are connected in parallel through a first three-way valve and a second three-way valve, and are connected to the main equipment.

3. The self-cascading semiconductor temperature control system with pre-cooling according to claim 1, characterized in that, The precooling subsystem further includes a first cold spray branch, which is connected to the rear end of the precooling compressor and the front end of the condenser. The first cold spray branch is equipped with a first cold spray solenoid valve and a cold spray thermostatic expansion valve. The rear end of the precooling compressor is equipped with a precooling exhaust temperature sensor. When the first exhaust temperature measured by the precooling exhaust temperature sensor exceeds a set threshold, the first cold spray solenoid valve opens. At the same time, the opening degree of the cold spray thermostatic expansion valve is controlled in real time according to the first exhaust temperature measured by the precooling exhaust temperature sensor.

4. The self-cascading semiconductor temperature control system with pre-cooling according to claim 3, characterized in that, The first precooling circuit is equipped with a first refrigeration electronic pulse valve and a first refrigeration thermostatic expansion valve. The first refrigeration electronic pulse valve is used to allow refrigerant to flow from the condenser into the first evaporator. The first refrigeration thermostatic expansion valve adjusts its opening according to the superheat of the first evaporator to regulate the real-time flow to the first evaporator.

5. The self-cascading semiconductor temperature control system with pre-cooling according to claim 1, characterized in that, When the real-time value monitored by the liquid supply temperature sensor is lower than -80℃, the third refrigeration electronic pulse valve closes, and throttling refrigeration is performed through the capillary branch.

6. A control method for a pre-cooled self-cascading semiconductor temperature control system, applied to the pre-cooled self-cascading semiconductor temperature control system as described in any one of claims 1-5, characterized in that, The control method includes: The temperature control device PLC receives instructions from the main equipment and determines the preset temperature threshold of the main equipment; When the preset temperature threshold of the main equipment is SV≥-40℃, it is determined that only the precooling subsystem is operating; When the preset temperature threshold of the main equipment is -140℃≤SV<-40℃, it is determined that the precooling subsystem and the self-cascading subsystem are operating simultaneously. The precooling compressor is started first, and the self-cascading compressor is started when the reading of the self-cascading exhaust pressure sensor reaches the preset value.

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