Temperature control device and control method based on PCM to isolate internal temperature fluctuations

Abstract

The present invention discloses a temperature control device and control method based on PCM to isolate internal temperature fluctuations. The bottom of the temperature control device is in contact with the controlled object, and the PCM phase change medium absorbs heat to control the temperature. A cooling medium is introduced into the microchannels surrounded by the PCM phase change medium on all sides. The PCM is maintained at the phase change temperature through a collaborative control algorithm. The isothermal heat absorption characteristics of the phase change latent heat are utilized to suppress pulse thermal fluctuations and isolate the interference of the low-temperature cooling medium on the environment. High-precision temperature-controlled water with the same temperature as the external environment is introduced into the outer microchannel to maintain the temperature of the upper surface of the device and to collaboratively maintain the phase change state of the PCM. The present invention achieves efficient temperature control while suppressing the pulse thermal fluctuations of the heating object and the thermal interference of the cooling medium on the environment, which is beneficial to the uniformity and stability of the internal ambient temperature of the lithography equipment.

Description

Technical Field

[0001] The present invention relates to a temperature control device for cooling and maintaining a constant temperature that can be used in the technical field of photolithography equipment, and in particular to a temperature control device based on PCM for isolating internal temperature fluctuations. Background Art

[0002] In semiconductor production, the precision moving parts, precision measuring components, and photolithography processes within lithography equipment are extremely sensitive to changes in ambient temperature. Therefore, their key components must operate in a microenvironment with stringent requirements for temperature, humidity, and cleanliness. Silicon wafer exposure within lithography equipment utilizes radiation of a specific wavelength to project the circuit pattern designed on the mask onto the photoresist through an optical system, achieving pattern transfer. This is a critical step in the photolithography process for integrated circuit manufacturing. During the exposure process, the lithography equipment must maintain uniform and stable temperature within its internal space to provide a stable exposure space and prevent degradation of semiconductor overlay accuracy. Key technical specifications for temperature are maintaining an ambient temperature of 22°C with a temperature fluctuation of less than 0.05°C. Furthermore, higher temperature accuracy is required in the primary exposure area, with long-term temperature fluctuations not exceeding 0.01°C.

[0003] Temperature control of temperature-sensitive areas within lithography equipment typically utilizes an air bath approach. This involves active constant-temperature cooling or internal constant-temperature air circulation to achieve high-precision temperature stability in the core area, isolating the impact of external ambient temperature fluctuations or temperature fluctuations of adjacent equipment components, and achieving localized temperature stability and good temperature uniformity within the area. For example, Chinese invention patent publication number CN102540750A discloses a lithography equipment environmental control system that provides clean, temperature-stable air to the lithography equipment environment, but it cannot control the temperature of heat-generating components within the lithography equipment. Direct temperature control achieves stable temperature control through heat exchange between ultra-precision temperature-controlled water and the temperature-controlled objects within the lithography equipment. For example, Chinese invention patent publication number CN114047673A discloses a temperature control device that isolates internal fluctuations and its decoupling control method. This method isolates internal temperature fluctuations and the effects of the cooling medium on the environment by controlling whether cooling water flows through the interlayer flow channel and providing an outer constant-temperature flow channel. However, this method cannot immediately address heat overflow caused by transient pulse thermal fluctuations. The heat interference caused by these pulse thermal fluctuations must be absorbed only after the coolant in the second layer flows in. This delay inevitably leads to a certain amount of heat overflow and temperature fluctuations in the surrounding environment. Another example is Chinese utility model patent publication number CN208922064U, which discloses a cooling structure, a main substrate cooling device, and a photolithography machine. These devices directly cool and dissipate heat from the mainboard via circulating coolant. However, this method only considers the heat dissipation of heat-generating components and does not consider the impact of the low-temperature coolant flow in the temperature control device on the surrounding temperature. This can cause local temperature fluctuations around the device, thereby affecting the overall temperature uniformity and stability within the photolithography machine. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention aims to address the problem that the existing temperature control devices inside lithography machines cannot meet the demand for suppressing pulse thermal fluctuations, as well as the secondary thermal interference problem caused by the cooling medium on the environment. The present invention provides a temperature control device based on PCM to isolate internal temperature fluctuations. The device is mainly used to solve the problem of instantaneous heat overflow caused by pulse thermal fluctuations generated by the heating objects due to periodic operation or start-up and shutdown when temperature controlling the heating objects inside the lithography equipment, and the secondary thermal interference phenomenon caused by heat exchange between the temperature-controlled cooling medium and the external environment; and provides a collaborative control algorithm for the device, which accurately measures the real-time temperature of the lower surface of the device box by means of a built-in temperature sensor in the device, and adjusts the flow rate of the cooling medium in real time to maintain the PCM medium at the phase change temperature.

[0005] The technical solution adopted in the present invention is:

[0006] 1. A temperature control device based on PCM to isolate internal temperature fluctuations:

[0007] The device comprises a device box, an outer microfluidic channel, a PCM wrapping layer, an inner microfluidic channel and multiple temperature sensors; the outer microfluidic channel, the PCM wrapping layer and the inner microfluidic channel are arranged inside the device box, the outer microfluidic channel is arranged on the upper part of the inner part of the device box, the PCM wrapping layer and the inner microfluidic channel are below the outer microfluidic channel, and the PCM wrapping layer surrounds the inner microfluidic channel; the device box, the outer microfluidic channel, the PCM wrapping layer and the inner microfluidic channel are all arranged with temperature sensors, and the bottom surface of the device box is in contact with the surface of the controlled object.

[0008] The outer microchannel, PCM wrapping layer and inner microchannel are all set at both ends of the device box; the two ends of the inner microchannel serve as the cooling medium inlet and cooling medium outlet respectively, the two ends of the PCM wrapping layer serve as the PCM medium injection port and PCM medium discharge port respectively, and the two ends of the outer microchannel serve as the temperature control water inlet and temperature control water outlet respectively, and the cooling medium inlet, PCM medium injection port and temperature control water inlet are respectively located on the same side, and the cooling medium outlet, PCM medium discharge port and temperature control water outlet are located on the same side.

[0009] Temperature sensors are arranged at the middle of the bottom and top of the device box, the temperature control water outlet, the cooling medium outlet, and the PCM medium outlet.

[0010] The inner layer microchannel is composed of a layer of multiple microchannel grooves arranged in parallel and then merged at two ends, and the two ends are respectively connected to the cooling medium inlet and the cooling medium outlet.

[0011] The cooling medium inlet is connected to an electromagnetic flow valve for electrically coordinating the flow of the cooling medium.

[0012] The PCM wrapping layer is a U-shaped hollow flow channel, with both ends connected to the PCM medium injection port and the PCM medium discharge port respectively. The PCM medium injection port and the PCM medium discharge port are provided with switch valves for controlling the injection or discharge of the PCM medium.

[0013] The outer layer of microchannels is composed of a layer of multiple microchannel grooves arranged in parallel and then converging at both ends.

[0014] The PCM wrapping layer is filled with foam copper.

[0015] The device box body is made of copper.

[0016] The bottom surface of the device box body is coated with a heat-absorbing coating.

[0017] The controlled object is a heat-generating object.

[0018] 2. A temperature control and coordinated control method thereof:

[0019] Introduce cooling medium into the inner microchannel, and adjust the flow rate of cooling medium through the electromagnetic flow valve. Introduce temperature-controlled water with the same temperature as the external environment into the outer microchannel. Introduce PCM medium into the PCM wrapping layer until the wrapping layer is filled with PCM medium. Close the switch valves at the PCM medium injection port and PCM medium discharge port. Put the bottom surface of the device box into contact with the surface of the controlled object, and then:

[0020] The heat from the surface of the controlled object exchanges heat with the bottom of the device box and is transferred to the PCM wrapping layer. The PCM medium in the PCM wrapping layer first performs heat exchange to absorb heat from the controlled object. Then, the cooling medium in the inner microchannel controls the temperature of the PCM medium in the PCM wrapping layer, keeping the PCM medium at the phase change temperature. Temperature-controlled water at the same temperature as the outside world flows through the outer microchannel to absorb the excess heat or cooling dissipated by the PCM wrapping layer when controlling the controlled object, which exceeds the latent heat of phase change. This keeps the surface temperature of the device box consistent with the outside temperature.

[0021] The temperature-controlled water is a water medium driven to flow by external constant temperature.

[0022] The temperature control device of the present invention is used in a very strict temperature environment, such as a photolithography machine, where the temperature rise of the controlled object caused by the heat emitted is less than 0.05°C relative to the temperature of the outside world. Otherwise, the stability and uniformity of the temperature environment will be destroyed, resulting in the inability to operate the temperature environment. Therefore, the above-mentioned device structure is designed to perform strict temperature control. The temperature control device of the present invention can ensure that the ambient temperature remains unchanged. Then, when controlling the temperature of a heating object, the device is used to isolate the heating object from the instantaneous heat overflow caused by the pulse heat fluctuations generated by the periodic operation or start-stop moment and the influence of the cooling medium on the environment.

[0023] The phase change temperature of the PCM medium is lower than the temperature of the temperature-controlled water.

[0024] The phase transition temperature of the PCM is a fixed physical property, but the specific PCM formulation can be adjusted by varying the ratio of its components. The temperature of the temperature-controlled water is also fixed. In practice, it can be set either above or below the temperature, as long as it is within ±0.01°C of the temperature-controlled water. The goal is to minimize temperature differences and reduce the impact of the PCM on the temperature-controlled water, ensuring consistency between the temperature-controlled water and the ambient temperature.

[0025] During the method processing, the temperature t1 of the surface of the controlled object is monitored in real time by the temperature sensor arranged on the bottom surface of the device box body. The electromagnetic flow valve at the inlet of the cooling medium is used for coordinated control, thereby changing the flow of the cooling medium entering the inner microchannel to control the temperature, thereby isolating the internal temperature fluctuation. Specifically:

[0026] First, the upper threshold t that can break the phase change latent heat state of the PCM medium is set according to the following formula: 01 and the lower threshold t 02 :

[0027]

[0028]

[0029] Where r is the phase change heat of the PCM medium, m is the mass of the phase change medium, t2, t3, t0 and t s are respectively the cooling medium temperature, the temperature of the temperature-controlled water, the phase change temperature of the PCM medium and the reserved safety threshold; b1, b2 and b3 are respectively the thickness of the metal wall of the lower surface of the device box and the PCM wrapping layer, the thickness of the metal wall of the inner microchannel and the PCM wrapping layer, and the thickness of the metal wall between the outer microchannel and the PCM wrapping layer; λ1, λ2, λ3 are respectively the thermal conductivity of the metal wall of the lower surface of the device box and the PCM wrapping layer, the thermal conductivity of the metal wall of the inner microchannel and the PCM wrapping layer, and the thickness of the metal wall between the outer microchannel and the PCM wrapping layer; A1, A2, A3 are respectively the heat transfer area of ​​the lower surface of the device box and the PCM wrapping layer, the heat transfer area of ​​the inner microchannel and the PCM wrapping layer, and the heat transfer area of ​​the outer microchannel and the PCM wrapping layer;

[0030] Then, the surface temperature t1 of the controlled object detected by the temperature sensor on the bottom of the device box is compared with the upper limit of the temperature threshold t 01 and the lower threshold t 02 For comparison:

[0031] If the surface temperature t1 of the controlled object is higher than the upper threshold value, the electromagnetic flow valve is adjusted to increase the flow rate of the cooling medium entering the inner microchannel;

[0032] When the surface temperature t1 of the controlled object is lower than the lower threshold, the electromagnetic flow valve is adjusted to reduce the flow of the cooling medium into the inner microchannel, so that the PCM medium absorbs and releases heat isothermally under the phase change latent heat state;

[0033] When the surface temperature t1 of the controlled object is not lower than the lower threshold and not higher than the upper threshold, adjust the opening of the electromagnetic flow valve to control the flow of the inner microchannel cooling medium at the flow setting value q vs , the flow setting value q vs The calculation formula is as follows:

[0034]

[0035] Where, ρ is the cooling medium density; q0 is the cooling medium flow rate at the lower threshold temperature; C p is the specific heat capacity of the cooling medium; ΔT is the temperature difference after heat exchange of the cooling medium.

[0036] The flow rate of the inner microchannel cooling medium is controlled at q vs In this way, when instantaneous pulse thermal fluctuations occur, the pulse thermal fluctuations can be suppressed by the latent heat margin, and sufficient time is left for the flow adjustment of the inner microchannel cooling medium.

[0037] The temperature sensor integrated into the lower surface of the device's housing, due to its proximity to the controlled object, can quickly and accurately monitor the object's surface temperature in real time, thereby adjusting the flow of cooling medium entering the inner microchannels. In this way, the temperature sensor on the bottom of the device housing collects the object's real-time temperature, and the flow of cooling medium in the inner microchannels is adjusted in real time according to the collaborative control algorithm, achieving the goal of controlling the temperature of the controlled object.

[0038] High-precision temperature-controlled water with the same temperature as the outside world is introduced into the outer microchannels. The temperature of the external environment is detected by the temperature sensor on the outside of the device box. Temperature compensation is performed by the constant temperature water in the outer microchannels to maintain the stability of the temperature around the equipment. The PCM medium is maintained in a phase change latent heat state through heat transfer, reducing the possibility of the PCM medium exiting the phase change latent heat state due to a sudden decrease in the heat generated by the controlled object.

[0039] The present invention sets up a temperature control component by integrating an inner microchannel, a PCM wrapping layer, and an outer microchannel with a temperature sensor. The isothermal heat absorption and heat release characteristics of the PCM in the PCM wrapping layer during phase change latent heat are utilized, and the outer microchannel flows temperature-controlled water at the same temperature as the ambient temperature to isolate the pulse thermal fluctuations of the controlled object and the secondary thermal interference of the low-temperature cooling medium on the environment. The flow rate of the cooling medium flowing into the inner microchannel is controlled by a collaborative control algorithm to ensure that the PCM medium in the PCM wrapping layer is maintained in the phase change latent heat state under the combined action of the heat generated by the controlled object, the cooling medium, and the temperature-controlled water in the outer microchannel.

[0040] The bottom of the temperature control device of the present invention contacts the controlled object, and the PCM phase change medium absorbs heat to control the temperature. A cooling medium is introduced into the microchannels surrounded by the PCM phase change medium on all four sides. A coordinated control algorithm is used to maintain the PCM at the phase change temperature. The isothermal heat absorption characteristics of the phase change latent heat are utilized to suppress pulse thermal fluctuations and isolate the low-temperature cooling medium from interference with the environment. High-precision temperature-controlled water at the same temperature as the external environment is introduced into the outer microchannels to maintain the temperature of the device's upper surface and coordinately maintain the PCM's phase change state.

[0041] The beneficial effects of the present invention are:

[0042] In the present invention, when controlling the temperature of a controlled object, the PCM wrapping layer utilizes the isothermal heat absorption and heat release characteristics of the PCM phase change latent heat process, in conjunction with the cooling medium in the inner microchannels surrounded by the PCM wrapping layer on all four sides, to maintain the PCM medium at the phase change temperature. Moreover, since the inner microchannels are wrapped in the PCM medium, all the cold energy of the cooling medium will be absorbed by the PCM medium, which helps to maintain the entire temperature control device at a constant temperature. The outer microchannels flow temperature control water, which helps to reduce the impact of the cooling medium and phase change medium on the external environment, and can help the PCM phase change medium maintain its phase change latent heat state through heat transfer.

[0043] When pulse thermal fluctuations cause instantaneous heat overflow, the present invention uses the PCM's characteristic of isothermal heat absorption during phase change latent heat to leave sufficient time for regulating the flow rate of the inner microchannel cooling medium, thereby isolating heat from overflowing to the external environment and helping to maintain the temperature stability of the device. The microchannel structure with built-in sensors facilitates real-time monitoring and control of the temperature of the controlled object. In addition, its compact structure and small thickness facilitate its use on complex lithography equipment.

[0044] In summary, the present invention achieves efficient temperature control while suppressing the pulse thermal fluctuations of the heating object and the thermal interference of the cooling medium on the environment, which is beneficial to the uniformity and stability of the internal ambient temperature of the lithography equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the internal flow channel structure of the device of the present invention;

[0046] Figure 2 It is a front cross-sectional schematic diagram of the present invention;

[0047] Figure 3 It is a right side cross-sectional schematic diagram of the present invention;

[0048] Figure 4 Schematic diagram of the cross section of the outer microchannel of the present invention;

[0049] Figure 5 Schematic diagram of the cross section of the outer microchannel of the present invention;

[0050] Figure 6 This is a flow chart of the control method of the present invention.

[0051] In the figure: device box 1, outer microchannel 2, PCM wrapping layer 3, inner microchannel 4, temperature control water inlet 5, PCM medium injection port 6, cooling medium inlet 7, temperature control water outlet 8, PCM medium discharge port 9, coolant medium outlet 10, temperature sensors 11, 12, 13, 14, 15. DETAILED DESCRIPTION

[0052] The present invention is further described below with reference to the accompanying drawings and examples.

[0053] like Figure 1 As shown, the device includes a device box 1, an outer microfluidic channel 2, a PCM wrapping layer 3, an inner microfluidic channel 4 and a plurality of temperature sensors 11, 12, 13, 14 and 15; the outer microfluidic channel 2, the PCM wrapping layer 3 and the inner microfluidic channel 4 are provided inside the device box 1 from top to bottom, the outer microfluidic channel 2 is provided at the upper part of the interior of the device box 1, the PCM wrapping layer 3 and the inner microfluidic channel 4 are provided below the outer microfluidic channel 2, and the PCM wrapping layer 3 surrounds the inner microfluidic channel 4, and the inner microfluidic channel 4 is wrapped on all sides by the PCM wrapping layer 3; the device box 1, the outer microfluidic channel 2, the PCM wrapping layer 3 and the inner microfluidic channel 4 are all arranged with temperature sensors 11-15, and the bottom surface of the device box 1 is in contact with the surface of the controlled object.

[0054] The outer microfluidic channel 2, the PCM wrapping layer 3 and the inner microfluidic channel 4 are all set at both ends of the device box body 1; the two ends of the inner microfluidic channel 4 serve as the cooling medium inlet 7 and the cooling medium outlet 10 respectively, the two ends of the PCM wrapping layer 3 serve as the PCM medium injection port 6 and the PCM medium discharge port 9 respectively, and the two ends of the outer microfluidic channel 2 serve as the temperature control water inlet 5 and the temperature control water outlet 8 respectively, and the cooling medium inlet 7, the PCM medium injection port 6 and the temperature control water inlet 5 are respectively located on the same side, and the cooling medium outlet 10, the PCM medium discharge port 9 and the temperature control water outlet 8 are located on the same side.

[0055] The flow directions of the outer microchannel 2 , the PCM wrapping layer 3 and the inner microchannel 4 are parallel and parallel to the ends of the device box 1 .

[0056] The box body portion where the inner microfluidic channel 4 is located is arranged through upper and lower support columns.

[0057] Temperature-controlled water outlet 8, PCM medium outlet 9, and cooling medium outlet 10 are each equipped with temperature sensors 13-15, capable of quickly and accurately detecting the temperature of the controlled object. The bottom surface of device housing 1 is in contact with the surface of the controlled object. More preferably, temperature sensors 11-12 are also arranged in the center of the bottom surface of device housing 1 and the center of the top surface of device housing 1.

[0058] In the specific implementation, the temperature sensor 11 is integrated in the middle of the bottom surface of the device box body 1, the temperature sensor 12 is integrated in the center of the upper surface of the device box body 1, the temperature sensor 13 is integrated at the cooling medium outlet 10, the temperature sensor 14 is integrated at the PCM medium outlet 9, and the temperature sensor 15 is integrated at the temperature-controlled water outlet 8.

[0059] The temperature-controlled water inlet is the water inlet of the outer microchannel; the PCM medium injection port is the medium injection port of the PCM wrapping layer, which is connected to a switching valve; the夹 cooling medium inlet is the water inlet of the inner microchannel, which is connected to an electromagnetic flow valve; the temperature-controlled water outlet is the water outlet of the outer microchannel, and a temperature sensor is integrated at the outlet; the PCM medium discharge port is the medium discharge port of the PCM wrapping layer, and a temperature sensor is integrated at the outlet, and it is connected to a switching valve; the cooling medium outlet is the water outlet of the inner microchannel, and a temperature sensor is integrated at the outlet; the temperature sensor is located inside the assembled device and is led out by a lead wire, and the data collected by the temperature sensor is transmitted through the lead wire.

[0060] In this way, the device box body is a temperature control device cavity composed of an outer microchannel 2, a PCM wrapping layer 3, and an inner microchannel 4, and a temperature sensor is provided at the center of the upper surface of the outer wall.

[0061] The inner microchannel 4 is composed of a layer formed by arranging numerous microchannel grooves in parallel and converging at both ends. The two ends are respectively connected to the cooling medium inlet 7 and the cooling medium outlet 10. The cooling medium flows in from the cooling medium inlet 7 and flows out from the cooling medium outlet 10. An electromagnetic flow valve for jointly controlling the flow rate of the cooling medium is provided at the cooling medium inlet 7. The electromagnetic flow valve at the cooling medium inlet 7 is controlled by a joint control algorithm to adjust the flow rate of the cooling medium, so that the PCM medium in the PCM wrapping layer 3 is maintained in a state of latent heat of phase change and isothermal heat absorption and heat release, thereby realizing the optimization of internal fluctuations.

[0062] The PCM wrapping layer 3 is a similar hollow flow channel in a figure-eight shape. The two ends are respectively connected to the PCM medium injection port 6 and the PCM medium discharge port 9. The PCM medium flows in from the PCM medium injection port 6 and flows out from the PCM medium discharge port 9. Switching valves for controlling the injection or discharge of the PCM medium are provided at the PCM medium injection port 6 and the PCM medium discharge port 9, which is convenient for replacing the PCM medium.

[0063] The outer microchannel 2 is composed of a layer formed by arranging numerous microchannel grooves in parallel and converging at both ends. The numerous microchannel grooves are arranged in a uniformly distributed form between the top surface of the device box body 1 and the PCM wrapping layer 3, and the internal flow passes through high-precision temperature-controlled water with the same temperature as the external environment.

[0064] The PCM wrapping layer is filled with copper foam, the device box body is made of copper, and an endothermic coating is applied to the bottom surface of the device box body.

[0065] In a specific implementation, the controlled object is a lithography device. The device of the present invention can be integrally designed with the lithography device, but is not limited thereto. The bottom surface of the device box body 1 is arranged on the heating elements of the lithography device, such as the surface of the motor, the mask table, the workpiece table, etc.

[0066] A cooling medium is introduced into the inner microchannel 4, and the flow rate of the cooling medium is adjustable through the electromagnetic flow valve. High-precision temperature-controlled water with the same temperature as the external environment is introduced into the outer microchannel 2. PCM medium is introduced into the PCM wrapping layer 3 until the wrapping layer is filled with PCM medium. The switch valves at the PCM medium injection port 6 and the PCM medium discharge port 9 are closed. The bottom surface of the device box 1 is in contact with the surface of the controlled object. Then:

[0067] The heat on the surface of the controlled object exchanges heat with the bottom surface of the device box 1 and is transferred to the PCM wrapping layer 3. The PCM medium in the PCM wrapping layer 3 first performs heat exchange to absorb heat from the controlled object. Then, the cooling medium in the inner microchannel 4 controls the temperature of the PCM medium in the PCM wrapping layer 3, keeping the PCM medium at the phase change temperature. High-precision temperature-controlled water at the same temperature as the outside world flows through the outer microchannel 2 to absorb the excess heat or subcooling that exceeds the phase change latent heat dissipated by the PCM wrapping layer 3 when controlling the controlled object, so that the temperature of the device box 1 surface remains consistent with the outside temperature.

[0068] The phase transition temperature of the PCM medium is slightly lower than the temperature of the high-precision temperature-controlled water. The specific implementation is to select the PCM medium and adjust the ratio of the materials it contains to achieve this setting, for example, to make the phase transition temperature 21.99°C and the temperature of the high-precision temperature-controlled water 22°C.

[0069] The embodiment designs the inner micro-channel 4 and the corresponding control method.

[0070] Its control method is as follows Figure 6 As shown, during the method processing, as Figure 3 As shown, according to the temperature sensors 11, 13-15 in the middle of the bottom surface of the device box body 1, the temperature-controlled water outlet 8, the PCM medium outlet 9, and the cooling medium outlet 10, the temperature t1 of the surface of the controlled object is monitored in real time by the temperature sensor 11 integrated in the bottom surface of the device box body 1, and the electromagnetic flow valve at the cooling medium inlet 7 is coordinated with the control to change the flow of the cooling medium entering the inner microchannel 4 for temperature control, thereby isolating the internal temperature fluctuation. Specifically:

[0071] First, the upper threshold t that can break the phase change latent heat state of the PCM medium is set according to the following formula: 01 and the lower threshold t 02 :

[0072]

[0073]

[0074] Where r is the phase change heat of the PCM medium, m is the mass of the phase change medium, t2, t3, t0 and t sare respectively the cooling medium temperature, the temperature of the temperature-controlled water, the phase change temperature of the PCM medium and the reserved safety threshold; b1, b2 and b3 are respectively the thickness of the metal wall of the lower surface of the device box and the PCM wrapping layer, the thickness of the metal wall of the inner microchannel and the PCM wrapping layer, and the thickness of the metal wall between the outer microchannel and the PCM wrapping layer; λ1, λ2, λ3 are respectively the thermal conductivity of the metal wall of the lower surface of the device box and the PCM wrapping layer, the thermal conductivity of the metal wall of the inner microchannel and the PCM wrapping layer, and the thickness of the metal wall between the outer microchannel and the PCM wrapping layer; A1, A2, A3 are respectively the heat transfer area of ​​the lower surface of the device box and the PCM wrapping layer, the heat transfer area of ​​the inner microchannel and the PCM wrapping layer, and the heat transfer area of ​​the outer microchannel and the PCM wrapping layer;

[0075] The cooling medium temperature t2, the temperature control water temperature t3, and the PCM medium phase change temperature t0 are respectively collected and obtained by the temperature sensors 15, 14, and 13 at the temperature control water outlet 8, the PCM medium outlet 9, and the cooling medium outlet 10.

[0076] Then, the surface temperature t1 of the controlled object detected by the temperature sensor 11 on the bottom of the device box 1 is compared with the upper limit of the temperature threshold t 01 and the lower threshold t 02 For comparison:

[0077] If the surface temperature t1 of the controlled object is higher than the upper threshold value, the electromagnetic flow valve is adjusted to increase the flow rate of the cooling medium entering the inner microchannel 4;

[0078] When the surface temperature t1 of the controlled object is lower than the lower threshold, the electromagnetic flow valve is adjusted to reduce the flow of the cooling medium into the inner microchannel 4, so that the PCM medium absorbs and releases heat isothermally in the state of phase change latent heat;

[0079] When the surface temperature t1 of the controlled object is not lower than the lower threshold and not higher than the upper threshold, the opening of the electromagnetic flow valve is adjusted to control the flow rate of the cooling medium in the inner microchannel 4 to the flow setting value q vs , flow setting value q vs The calculation formula is as follows:

[0080]

[0081] Where, ρ is the cooling medium density; q0 is the cooling medium flow rate at the lower threshold temperature; C p is the specific heat capacity of the cooling medium; ΔT is the temperature difference of the cooling medium after heat exchange, which is calculated from the measurement value of the temperature sensor 13 at the cooling medium outlet 10 and the cooling medium temperature t2.

[0082] In specific implementations, the outer microchannels 1 also exchange heat with the external environment in real time, and temperature compensation is performed accordingly. The temperature of the external environment is detected in real time by the temperature sensor 12 on the top surface of the device box 1. When a temperature difference occurs between the temperature-controlled water in the outer microchannels 1 and the external environment, part of the heat will be absorbed and carried away by the temperature-controlled water, and part of the heat will be transferred to the medium of the PCM wrapping layer 3. The cooling medium of the inner microchannels 4 exchanges heat with the medium of the PCM wrapping layer 3 to collaboratively maintain the phase change latent heat state of the PCM medium.

[0083] The data from the temperature sensor 11 on the lower surface of the device housing 1 is collected and compared with a temperature threshold. When the temperature exceeds the upper threshold, the electromagnetic flow valve opening is increased to increase the flow rate of the inner microchannel cooling medium. When the temperature falls below the lower threshold, the electromagnetic flow valve opening is decreased to reduce the flow rate of the inner microchannel cooling medium. By regulating the flow rate of the inner microchannel cooling medium, the PCM phase change medium is maintained at the phase change temperature, preventing the pulsed thermal fluctuations of the controlled object and the cooling medium from being transferred to the external environment, causing adverse effects. The temperature of the PCM phase change medium is monitored by the temperature sensor 9 in the PCM wrapping layer.

[0084] Otherwise, when working normally between the upper threshold and the lower threshold, the flow rate of the inner microchannel cooling medium is maintained at the set value q vs At this time, the heat storage capacity of the PCM phase change medium is half of its total phase change latent heat. By leaving enough latent heat margin, the pulse thermal fluctuation is suppressed and sufficient time is left for the adjustment of the cooling medium flow rate of the inner microchannel.

[0085] This method is helpful to ensure the heat absorption temperature control efficiency of the PCM wrapping layer 6 and reduce the thermal pulse of the controlled heating object and the thermal interference of the cooling medium in the inner microchannel 2 on the environment around the device box.

[0086] From this implementation, it can be seen that the present invention achieves efficient temperature control while avoiding thermal interference of the coolant on the environment, which is beneficial to the uniformity and stability of the internal ambient temperature of the lithography equipment, and the design structure is compact, which is conducive to use inside complex lithography machines.

[0087] In the description of the positional relationship of the present invention, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate orientation or positional relationship are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0088] The above content and structure describe the basic principles, main features, and advantages of the product of the present invention, which should be understood by those skilled in the art. The above examples and description are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications are intended to be within the scope of the invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A temperature control device based on PCM to isolate internal temperature fluctuations, characterized by: The invention comprises a device box body (1), an outer micro-channel (2), a PCM wrapping layer (3), an inner micro-channel (4) and a plurality of temperature sensors (11, 12, 13, 14, 15); the outer micro-channel (2), the PCM wrapping layer (3) and the inner micro-channel (4) are provided inside the device box body (1); the outer micro-channel (2), the PCM wrapping layer (3) and the inner micro-channel (4) are provided at the upper part of the inside of the device box body (1); the PCM wrapping layer (3) and the inner micro-channel (4) are surrounded by the PCM wrapping layer (3); the device box body (1), the outer micro-channel (2), the PCM wrapping layer (3) and the inner micro-channel (4) are all provided with temperature sensors (11-15); the bottom surface of the device box body (1) is in contact with the surface of the controlled object; The outer microchannel (2), PCM wrapping layer (3) and inner microchannel (4) are all arranged through both ends of the device box body (1); the two ends of the inner microchannel (4) serve as a cooling medium inlet (7) and a cooling medium outlet (10), respectively; the two ends of the PCM wrapping layer (3) serve as a PCM medium injection port (6) and a PCM medium discharge port (9), respectively; the two ends of the outer microchannel (2) serve as a temperature-controlled water inlet (5) and a temperature-controlled water outlet (8), respectively; the cooling medium inlet (7), the PCM medium injection port (6) and the temperature-controlled water inlet (5) are respectively located on the same side; the cooling medium outlet (10), the PCM medium discharge port (9) and the temperature-controlled water outlet (8) are respectively located on the same side; The cooling medium inlet (7) is connected to an electromagnetic flow valve for electrically coordinating the flow of the cooling medium; the PCM wrapping layer (3) is a U-shaped hollow flow channel, with both ends respectively connected to the PCM medium injection port (6) and the PCM medium discharge port (9); the PCM medium injection port (6) and the PCM medium discharge port (9) are provided with switch valves for controlling the injection or discharge of the PCM medium.

2. The temperature control device based on PCM to isolate internal temperature fluctuations according to claim 1, characterized in that: Temperature sensors (11-15) are arranged at the center of the bottom and top of the device box body (1), the temperature control water outlet (8), the cooling medium outlet (10), and the PCM medium outlet (9).

3. The temperature control device based on PCM to isolate internal temperature fluctuations according to claim 1, characterized in that: The inner layer microchannel (4) is composed of a layer of multiple microchannel grooves arranged in parallel and then merged at both ends, and the two ends are respectively connected to the cooling medium inlet (7) and the cooling medium outlet (10).

4. The temperature control device based on PCM to isolate internal temperature fluctuations according to claim 1, characterized in that: The outer layer microchannel (2) is composed of a layer of multiple microchannel grooves arranged in parallel and then joined at both ends.

5. The temperature control and coordinated control method for the temperature control device according to any one of claims 1 to 4, characterized in that: A cooling medium is introduced into the inner microchannel (4), and the flow rate of the cooling medium is adjustable through an electromagnetic flow valve. Temperature-controlled water having the same temperature as the external environment is introduced into the outer microchannel (2). PCM medium is introduced into the PCM wrapping layer (3) so that the wrapping layer is filled with PCM medium. The switch valves at the PCM medium injection port (6) and the PCM medium discharge port (9) are closed. The bottom surface of the device box (1) is brought into contact with the surface of the controlled object. Then: The heat on the surface of the controlled object is heat-exchanged with the bottom surface of the device box (1) and transferred to the PCM wrapping layer (3). The PCM medium in the PCM wrapping layer (3) firstly performs heat exchange to absorb the heat of the controlled object. Secondly, the PCM medium in the PCM wrapping layer (3) is temperature-controlled by the cooling medium in the inner microchannel (4) so ​​that the PCM medium is at a phase change temperature. The temperature-controlled water having the same temperature as the outside world flows through the outer microchannel (2) to absorb the excess heat or subcooling that exceeds the phase change latent heat dissipated by the PCM wrapping layer (3) when controlling the controlled object, so that the temperature of the device box (1) surface is kept consistent with the outside temperature.

6. The temperature control and coordinated control method according to claim 5, characterized in that: The phase change temperature of the PCM medium is lower than the temperature of the temperature-controlled water.

7. The temperature control and coordinated control method according to claim 5, characterized in that: During the method processing, the temperature t1 of the surface of the controlled object is monitored in real time by the temperature sensor (11) arranged on the bottom surface of the device box (1), and the electromagnetic flow valve at the cooling medium inlet (7) is combined with the control to change the flow of the cooling medium entering the inner microchannel (4) to control the temperature, thereby isolating the internal temperature fluctuation. Specifically, First, the upper threshold t that can break the phase change latent heat state of the PCM medium is set according to the following formula: 01 and the lower threshold t 02 : Where r is the phase change heat of the PCM medium, m is the mass of the phase change medium, t2, t3, t0 and t s are respectively the cooling medium temperature, the temperature of the temperature-controlled water, the phase change temperature of the PCM medium and the reserved safety threshold; b1, b2 and b3 are respectively the thickness of the metal wall of the lower surface of the device box and the PCM wrapping layer, the thickness of the metal wall of the inner microchannel and the PCM wrapping layer, and the thickness of the metal wall between the outer microchannel and the PCM wrapping layer; λ1, λ2, λ3 are respectively the thermal conductivity of the metal wall of the lower surface of the device box and the PCM wrapping layer, the thermal conductivity of the metal wall of the inner microchannel and the PCM wrapping layer, and the thickness of the metal wall between the outer microchannel and the PCM wrapping layer; A1, A2, A3 are respectively the heat transfer area of ​​the lower surface of the device box and the PCM wrapping layer, the heat transfer area of ​​the inner microchannel and the PCM wrapping layer, and the heat transfer area of ​​the outer microchannel and the PCM wrapping layer; Then, the surface temperature t1 of the controlled object detected by the temperature sensor (11) on the bottom of the device box (1) is compared with the upper limit of the temperature threshold t 01 and the lower threshold t 02 For comparison: If the surface temperature t1 of the controlled object is higher than the upper threshold value, the electromagnetic flow valve is adjusted to increase the flow rate of the cooling medium entering the inner microchannel (4); When the surface temperature t1 of the controlled object is lower than the lower threshold, the electromagnetic flow valve is adjusted to reduce the flow of the cooling medium into the inner microchannel (4), so that the PCM medium can absorb and release heat isothermally in the phase change latent heat state; When the surface temperature t1 of the controlled object is not lower than the lower threshold and not higher than the upper threshold, the opening of the electromagnetic flow valve is adjusted so that the flow rate of the cooling medium in the inner microchannel (4) is controlled at the flow setting value q vs , the flow setting value q vs The calculation formula is as follows: Where, ρ is the cooling medium density; q0 is the cooling medium flow rate at the lower threshold temperature; C p is the specific heat capacity of the cooling medium; ΔT is the temperature difference after heat exchange of the cooling medium.

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