Thermoelectric device integrated with embedded microfluidic channel, and preparation method and application thereof

Abstract

The application belongs to the technical field of electronic device heat management, and discloses an integrated embedded micro-channel thermoelectric device and a preparation method and application thereof. The device comprises a liquid supply manifold structure and a thermoelectric refrigerator connected with each other. A micro-channel structure is formed on a hot end substrate of the thermoelectric refrigerator. The liquid supply manifold structure comprises at least two connecting pipes, and the at least two connecting pipes are connected with the micro-channel structure respectively and form a liquid flow channel for the cooling medium to pass through. The device can remove the interface thermal resistance between the thermoelectric refrigerator and the micro-channel radiator, improve the cooling performance of the thermoelectric micro-channel, realize the precise temperature control of hot spots, the rapid response of dynamic heat load and the overall efficient cooling function.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal management of electronic devices, and more specifically, relates to a thermoelectric device with integrated embedded microchannels, its preparation method and application. Background Technology

[0002] Temperature-sensitive electronic and optoelectronic components, such as laser diodes, light-emitting diodes, and optoelectronic chips, require precise temperature control to maintain stable and efficient operation. Meanwhile, with the increasing integration of electronic devices, the space available for heat dissipation is shrinking, while the heat flux density of these devices is increasing, sometimes even reaching hundreds or even 1000 W / cm² in localized hotspot areas. When devices switch from low-power to high-power operation, these hotspots experience significant temperature rises. Therefore, efficient dynamic thermal management of localized hotspots within limited space is crucial for ensuring the reliable and stable operation of temperature-sensitive electronic devices.

[0003] Based on the Peltier effect, thermoelectric cooling devices, driven by direct current, transport heat from the cold end to the hot end, effectively controlling the hot spot temperature of temperature-sensitive electronic devices. They also offer advantages such as controllable size, fast response, and high reliability. However, the hot end of thermoelectric devices requires an efficient heat sink to ensure the cooling performance of the cold end. Among various heat sinks, microchannel heat sinks are widely used for heat dissipation of electronic devices in confined spaces due to their compact structure and high heat transfer coefficient. Therefore, using microchannel heat sinks for efficient heat dissipation of the hot end of thermoelectric coolers holds promise for achieving dynamic thermal management of hot spots in temperature-sensitive electronic devices.

[0004] Improving the cooling performance of thermoelectric microchannels can be achieved by optimizing the thermoelectric cooling devices and increasing their maximum cooling power, such as by reducing the thickness of the thermoelectric arms and increasing the thermoelectric figure of merit of the thermoelectric materials. However, this requires complex processes and is very expensive. Alternatively, the cooling performance of thermoelectric microchannels can also be improved by enhancing the heat transfer capacity of the hot end of the thermoelectric cooling devices, for example, by optimizing the flow channel structure in the microchannel heat sink. Furthermore, optimizing the connection between the thermoelectric devices and the microchannel heat sink is also crucial for improving the system's cooling capacity. The two devices are typically connected using traditional thermal interface materials such as thermal grease or solder, and the thermal interface resistance can account for more than 70% of the total thermal resistance of the hot end of the thermoelectric device. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides an integrated embedded microchannel thermoelectric device, its preparation method and application, which aims to solve the problem of how to improve the cooling performance of the microchannel structure of thermoelectric cooling devices.

[0006] To achieve the above objectives, according to one aspect of the present invention, an integrated embedded microchannel thermoelectric device is provided. The device includes a liquid supply manifold structure and a thermoelectric cooler connected together. A microchannel structure is formed on the hot end substrate of the thermoelectric cooler. The liquid supply manifold structure includes at least two connecting pipes, which are respectively connected to the microchannel structure and form a liquid channel for the passage of a cooling medium.

[0007] Furthermore, the connecting pipes include vertically connected vertical pipes and horizontal pipes.

[0008] Furthermore, the manifold liquid supply structure includes two connecting pipes, which are respectively connected to the inlet and outlet of the microchannel structure.

[0009] Furthermore, the manifold liquid supply structure includes three connecting pipes, one of which is connected to the inlet of the microchannel structure, and the other two connecting pipes are respectively connected to the outlet of the microchannel structure.

[0010] Furthermore, the microchannel structure is a parallel rectangular channel with a channel length ranging from 3mm to 6mm, a channel depth ranging from 50μm to 500μm, a channel width ranging from 20μm to 300μm, a channel spacing ranging from 20μm to 200μm, and a number ranging from 5 to 50.

[0011] Furthermore, the microchannel structure is a parallel S-shaped channel, the channel trajectory is composed of multiple arcs with a diameter ranging from 30μm to 200μm, the channel depth ranges from 50μm to 500μm, the channel width ranges from 20μm to 200μm, the channel spacing ranges from 40μm to 200μm, and the number ranges from 5 to 50.

[0012] Furthermore, the microchannel structure is a square needle-rib structure with a needle-rib height ranging from 50μm to 500μm, a needle-rib side length and width ranging from 20μm to 200μm, and a needle-rib spacing ranging from 20μm to 200μm.

[0013] The present invention also provides a method for fabricating an integrated embedded microchannel thermoelectric device as described above, wherein channels are etched on the hot end substrate of the thermoelectric cooler, and the channels serve as microchannel structures.

[0014] The present invention also provides a hot spot dynamic thermal management temperature measurement system, which includes a liquid supply circuit, a data acquisition and control system, and a thermoelectric device with an integrated embedded microchannel as described above. The thermoelectric device is connected to the liquid supply circuit and the data acquisition and control system.

[0015] In summary, compared with the prior art, the integrated embedded microchannel thermoelectric device, its fabrication method, and its application provided by this invention mainly have the following advantages:

[0016] Beneficial effects:

[0017] 1. A microchannel structure is formed on the hot end substrate of the thermoelectric cooler, thus realizing the integration of the microchannel and the thermoelectric cooler. This not only reduces the need for heat dissipation space, but also eliminates the interfacial thermal resistance between the microchannel heat sink and the thermoelectric cooler, improving the cooling performance of the thermoelectric microchannel and realizing precise temperature control of hot spots, rapid response to dynamic heat load, and overall efficient cooling function.

[0018] 2. The combination of the liquid supply manifold structure and the microchannel structure can enhance the jet impact and mixing disturbance of the volume, strengthen the microfluidic heat exchange capacity, and enhance the thermoelectric microchannel's ability to control the temperature of hot spots.

[0019] 3. Experiments also verified that the thermoelectric cooler with integrated embedded manifold microchannels eliminates the interfacial thermal resistance between the microchannels and the thermoelectric cooler. At the same time, the structure of the manifold embedded microchannels increases the heat exchange area and enhances fluid turbulence compared to direct water cooling. The two work together to enhance the heat exchange at the hot end of the thermoelectric device and improve the cooling performance of the combined thermoelectric microchannel cooling. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for fabricating an integrated embedded microchannel thermoelectric device provided by the present invention;

[0021] Figure 2 This is a schematic diagram of the integrated embedded microchannel thermoelectric device provided by the present invention;

[0022] Figure 3 This is a top view of the DC-channel embedded microchannel provided in an embodiment of the present invention;

[0023] Figure 4 This is a side view of a DC-channel embedded microchannel provided in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a one-inlet-one-outlet liquid supply manifold structure provided in an embodiment of the present invention;

[0025] Figure 6 This is a top view of the one-inlet-one-outlet liquid supply manifold structure provided in an embodiment of the present invention;

[0026] Figure 7 This is a side view of the one-inlet-one-outlet liquid supply manifold structure provided in an embodiment of the present invention;

[0027] Figure 8This is a schematic diagram of a one-inlet, one-outlet direct water-cooled heat sink provided in an embodiment of the present invention;

[0028] Figure 9 This is a top view of a one-inlet, one-outlet direct water-cooled heat sink provided in an embodiment of the present invention;

[0029] Figure 10 This is a side view of a one-inlet, one-outlet direct water-cooled heat sink provided in an embodiment of the present invention;

[0030] Figure 11 This is a schematic diagram of the hotspot dynamic thermal management temperature measurement system provided in an embodiment of the present invention;

[0031] Figure 12 This is a graph showing the relationship between hotspot power density and hotspot temperature provided in an embodiment of the present invention;

[0032] Figure 13 This is a graph showing the relationship between flow rate and hotspot temperature provided in an embodiment of the present invention;

[0033] Figure 14 In the figure, A and B are respectively a line graph of the hot spot temperature changing with time under a step change in hot spot power density and a graph of the relationship between the step change amplitude of hot spot power density and the maximum hot spot temperature change provided in the embodiments of the present invention.

[0034] Figure 15 In the figures, A and B are respectively a line graph showing the change of hot spot temperature over time under the change of hot spot power density pulse and a graph showing the relationship between the change of hot spot power density pulse amplitude and the change of maximum hot spot temperature provided in the embodiments of the present invention.

[0035] Figure 16 In the figures, A and B are respectively a line graph showing the change of hot spot temperature over time under the change of hot spot power density square wave and a graph showing the relationship between the change period of hot spot power density square wave and the change of maximum hot spot temperature provided in the embodiments of the present invention.

[0036] Figure 17 This is a top view of the S-channel type embedded microchannel provided in an embodiment of the present invention;

[0037] Figure 18 This is a top view of the micropillar-shaped embedded microchannel provided in an embodiment of the present invention;

[0038] Figure 19 This is a schematic diagram of a one-inlet, two-outlet liquid supply manifold structure provided in an embodiment of the present invention;

[0039] Figure 20 This is a top view of the one-inlet, two-outlet liquid supply manifold structure provided in an embodiment of the present invention;

[0040] Figure 21 This is a side view of the one-inlet, two-outlet liquid supply manifold structure provided in an embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0042] This invention provides a thermoelectric device with an integrated embedded microchannel. The device can eliminate the interfacial thermal resistance between the thermoelectric cooler and the microchannel heat sink, improve the cooling performance of the thermoelectric microchannel, and realize precise temperature control of hot spots, rapid response to dynamic heat load, and overall efficient cooling function.

[0043] The device includes a liquid supply manifold structure and a thermoelectric cooler connected together. A microchannel structure is formed on the hot end substrate of the thermoelectric cooler. The liquid supply manifold structure includes at least two connecting pipes, which are respectively connected to the microchannel structure and form a liquid channel for the cooling medium to pass through.

[0044] The connecting pipes include vertically connected vertical pipes and horizontal pipes. In one embodiment, the manifold fluid supply structure has two connecting pipes, each consisting of a rectangular pipe segment perpendicular to each other and a horizontal circular pipe segment connected together. The vertical pipe has a rectangular cross-section with a length ranging from 3mm to 6mm, a width ranging from 0.5mm to 1mm, and a length ranging from 5mm to 10mm. The horizontal pipe has a diameter ranging from 2mm to 5mm and a length ranging from 5mm to 10mm. Fluid enters the embedded microchannel from one connecting pipe and then flows out from the other connecting pipe.

[0045] In another embodiment, the manifold fluid supply structure has three connecting pipes, each consisting of a vertical rectangular pipe segment connected to a horizontal circular pipe segment. The vertical pipe has a rectangular cross-section with a length ranging from 3-6 mm, a width ranging from 0.5-1 mm, and a length ranging from 5-10 mm. The horizontal pipe has a diameter ranging from 2-5 mm and a length ranging from 5-10 mm. Fluid enters the embedded microchannel from the middle connecting pipe and flows out from the two connecting pipes on either side.

[0046] In one embodiment, the microchannel structure is a parallel rectangular channel with a channel length ranging from 3mm to 6mm, a channel depth ranging from 50μm to 500μm, a channel width ranging from 20μm to 300μm, a channel spacing ranging from 20μm to 200μm, and a number ranging from 5 to 50.

[0047] The microchannel structure can also be a parallel S-shaped channel, the channel trajectory is composed of multiple arcs with a diameter ranging from 30μm to 200μm, the channel depth ranges from 50μm to 500μm, the channel width ranges from 20μm to 200μm, the channel spacing ranges from 40μm to 200μm, and the number ranges from 5 to 50.

[0048] The microchannel structure can also be a square needle-rib structure, with a needle-rib height ranging from 50μm to 500μm, a needle-rib side length and width ranging from 20μm to 200μm, and a needle-rib spacing ranging from 20μm to 200μm.

[0049] Please see Figure 1 The present invention also provides a method for fabricating the thermoelectric device with integrated embedded microchannels as described above, the method mainly comprising the following steps:

[0050] S101, channels are etched on the hot-end substrate of the thermoelectric cooler. These channels serve as microchannel structures, enabling the integration of microchannels with the thermoelectric cooler. Specifically, channels can be fabricated on the hot-end substrate of the thermoelectric cooler using laser etching, plasma etching, or mechanical processing.

[0051] S102, fabricating a liquid supply manifold structure on a metal or ceramic substrate. The distribution of the liquid supply manifold structure must match the embedded microchannel structure to ensure that the cooling medium flows from the manifold inlet through the microchannels embedded in the thermoelectric cooler and then out of the manifold outlet. Specifically, the liquid supply manifold structure can be fabricated through machining or 3D printing.

[0052] S103: After fixing the thermoelectric cooler with embedded microchannels and the liquid supply manifold structure substrate with a clamp, the two parts are connected, and then the clamp is removed. Specifically, the connection method can be to fix and seal the interface with epoxy resin, or to weld the connection if metal plating pretreatment has been performed before fixing the thermoelectric cooler and the manifold microchannel substrate with etched microchannels.

[0053] Taking laser etching of channels as an example, in some specific embodiments, step S101 specifically includes the following steps:

[0054] The channel design pattern is imported into the laser etching equipment, and the two-dimensional channel structure model (which can be designed and drawn using 2D drawing software AutoCAD) is analyzed and processed to obtain the laser scanning sequence.

[0055] Furthermore, by adjusting the laser frequency and power of the laser etching equipment, the hot end substrate of the thermoelectric cooler is etched with channels. For example, nanosecond laser etching technology is used to expose a two-dimensional channel structure pattern on the hot end substrate of the thermoelectric cooler to be prepared according to the laser scanning sequence, so as to prepare embedded microchannels.

[0056] The laser etching technology used here can employ various laser types, such as femtosecond lasers, picosecond lasers, and nanosecond lasers. Different types of lasers will leave different structural morphologies on the surface after etching the channel structure; for example, nanosecond lasers produce channels with a larger inclination of the channel walls. Therefore, in actual laser etching, the specific laser frequency and power should be selected according to the actual situation.

[0057] Taking plasma etching as an example, in some specific embodiments, step S101 specifically includes: sequentially cleaning the hot-end substrate of the thermoelectric cooler with deionized water, isopropanol, or acetone to remove surface contaminants, and then drying the substrate with nitrogen. A layer of photoresist is spin-coated onto the substrate, controlling the spin speed and time to obtain the desired photoresist layer thickness. The photoresist-coated substrate is pre-baked in a hot plate or oven to remove solvent from the photoresist. The designed channel mask pattern is projected onto the photoresist layer using an ultraviolet exposure machine. The exposed substrate is immersed in a developing solution; the time and conditions are determined according to the type and thickness of the photoresist. After development, it is rinsed with deionized water to remove residual developing solution. It is baked in an oven to enhance the photoresist's resistance to etching and its adhesion. The ceramic substrate is etched using a plasma etching machine, adjusting the flow rate of each etching gas, the required radio frequency power for plasma generation, and the etching time. During the etching process, the substrate can be back-side cooled to prevent overheating. Subsequently, residual photoresist is removed and the substrate is cleaned.

[0058] Taking machining as an example, in some specific embodiments, step S101 specifically includes: according to the designed etching groove pattern, using a conventional lathe, CNC lathe, etc., to perform groove processing on the hot end substrate of the thermoelectric cooler to obtain embedded microchannels.

[0059] Taking machining as an example, in some specific embodiments, step S102 specifically includes the following steps: according to the designed liquid supply manifold structure, the base material is processed using a conventional lathe, CNC lathe, etc., to obtain the liquid supply manifold structure. Optionally, the base material can be metal or ceramic.

[0060] Taking 3D printing as an example, in some specific embodiments, step S102 specifically includes the following steps: Designing the liquid supply manifold structure using 3D design software, and then slicing the 3D structure model layer by layer to obtain a set of 2D structure images. Selecting suitable metal powder, such as stainless steel, aluminum alloy, or other metal 3D printing powders. Calibrating the flatness and alignment of the printing platform, and uniformly laying the metal powder on the printing platform through the powder supply system. The laser in the printing equipment scans the metal powder according to the path generated by the slicing software, melting and solidifying it layer by layer. This process is repeated continuously until all layers of the liquid supply manifold structure are printed.

[0061] Taking epoxy resin bonding as an example, in some specific embodiments, step S103 specifically includes the following steps: clamping the embedded microchannel thermoelectric cooler prepared in step S101 with the liquid supply manifold structure prepared in step S102 using a clamp. Then, apply epoxy resin adhesive to the junction and let it stand for a period of time to allow the epoxy resin adhesive to cure.

[0062] Taking welding connection as an example, in some specific embodiments, step S103 specifically includes the following steps:

[0063] If the contact portion between the embedded microchannel thermoelectric cooler prepared in step S101 and the liquid supply manifold structure prepared in step S102 is made of metal, the thermoelectric cooler and the liquid supply manifold structure can be clamped together and placed on a heating stage. Turn on the heating stage, and when the temperature of the joint reaches the required soldering temperature, apply soldering coating. Turn off the heating stage after the solder coating melts. If the contact portion between the embedded microchannel thermoelectric cooler prepared in step S101 and the liquid supply manifold structure prepared in step S102 is not metal, a metal plating pretreatment is required. Optionally, the metal plating pretreatment can be magnetron sputtering, electron beam evaporation, chemical electrodeposition, etc.

[0064] This application also provides an embedded manifold microchannel structure on a thermoelectric cooler hot end substrate, the structure being obtained by the thermoelectric cooler fabrication method of integrated embedded manifold microchannel as described in any of the above embodiments, for example including: a thermoelectric cooler with an integrated one-in-one-out manifold direct-flow embedded microchannel for cooling elongated hot spots.

[0065] Please see Figure 2 The liquid supply manifold structure features a single inlet and single outlet liquid supply method, while the embedded microchannel is a direct-flow embedded microchannel. The thermoelectric cooler connected to the liquid supply manifold structure and the embedded microchannel is fixedly connected by applying epoxy resin adhesive at the interface. The elongated simulated hotspot chip measures 1.6 mm in length, 0.55 mm in width, and 0.4 mm in height, and is used to simulate the high heat flux hotspot heating of electronic devices. The simulated hotspot chip and the thermoelectric cooler are bonded using nano-silver paste. Specifically, a thin and uniform layer of nano-silver paste is applied to the cold end substrate of the thermoelectric cooler integrating the embedded manifold microchannel. The simulated hotspot chip is placed on the silver paste, clamped and fixed, and cured in a 100°C constant temperature oven for 2 hours.

[0066] Please see Figure 3 and Figure 4 This DC-channel embedded microfluidic system consists of 25 rectangular channels. Each channel has a length of L. 11 =5mm, width W1 =0.1mm. Channel spacing S1 =0.1mm, total channel area width L 12 =5mm, channel depth H1=0.2mm.

[0067] Please see Figure 5 , Figure 6 and Figure 7 The base of the liquid supply manifold structure is square, with a side length L. M11 =50mm, height H M11 =11.5mm. The top of the fluid supply manifold structure has a long L-shaped section. M12 =8mm, width W M11 =8mm, depth H M12 A 0.4mm groove is used to position the liquid supply manifold structure and its connection to the embedded microchannels of the thermoelectric cooler's hot-end substrate. This one-in-one-out liquid supply manifold structure has two connecting pipes for supplying liquid to the embedded microchannels. Each connecting pipe consists of a vertical rectangular pipe segment connected to a horizontal circular pipe segment. The rectangular cross-section of the vertical pipe has a length L. M13 =5mm, with the total width L of the embedded microchannel 12 They are equal; the width of the rectangular cross-section is W. M12 =1mm; the total width of the two rectangular flow channels is W M13 =5mm, with the total width L of the embedded microchannel 11 Equal; the length of the vertical pipe is H M13 =6mm. The diameter range of horizontal pipes is D. M11 =5mm, the outer diameter of the horizontal pipe outside the base is D M12 =7mm. Fluid enters the embedded microchannel from one connecting tube and flows out from another connecting tube. The four diameters W around the liquid supply structure... M13 A 6mm hole is used to secure the entire cooling system to the test platform.

[0068] To compare the performance improvement of thermoelectric coolers by integrated embedded manifold microchannels, direct water-cooled thermoelectric coolers and commercially available microchannel-cooled thermoelectric coolers were fabricated. All three share the same analog hotspot chip and thermoelectric cooler.

[0069] Please see Figure 8 , Figure 9 and Figure 10 The substrate for the direct water-cooled heat sink is square with a side length L. M21 =50mm, height H M21 =11.5mm. The top of the direct water-cooled heat sink has a long L... M22 =8mm, width W M21 =8mm, depth H M22 A 0.4mm groove is used to position the direct water-cooled heat sink and the hot-end substrate of the thermoelectric cooler. This one-in-one-out direct water-cooled heat sink has a horizontal cooling section and two connecting pipes. Each connecting pipe consists of a vertical rectangular pipe section and a horizontal circular pipe section connected together. The length L of the horizontal cooling section is...M23 =5mm, width W M22 =5mm, depth H M23 =0.2mm. The length of the rectangular cross-section of the vertical pipe is equal to that of the horizontal cooling section, and the width of the rectangular cross-section is W. M23 =1mm, vertical pipe length is H M24 =6mm. The diameter range of a horizontal circular pipe is D. M21 =5mm, the outer diameter of the horizontal circular pipe outside the base is D M22 =7mm. Fluid enters the horizontal cooling section from one connecting pipe and flows out from another connecting pipe. The liquid supply structure has four diameters W around it. M23 A 6mm hole is used to secure the entire cooling module to the test platform.

[0070] Please see Figure 11 This invention also provides a dynamic thermal management temperature measurement system for hot spots. This system includes a liquid supply circuit, a data acquisition and control system, and a thermoelectric device with an integrated embedded microchannel. The thermoelectric device connects the liquid supply circuit to the data acquisition and control system. The liquid supply circuit consists of a water tank, a high-precision circulating pump, a flow meter, a filter, a heat exchanger, and a cooling system. The liquid supply circuit uses deionized water as the cooling medium, and the coolant can be controlled to enter the microchannel at a predetermined temperature and flow rate. The data acquisition and control system consists of a high-precision DC power supply, a data acquisition instrument, a differential pressure gauge, a thermocouple, an infrared camera, and a control computer. The dynamic thermal management temperature measurement system can input chip power and thermoelectric cooler current according to a set program, and collect the actual microchannel flow rate, module inlet and outlet pressure loss, and hot spot temperature in real time.

[0071] Please see Figure 12 and Figure 13 The cooling performance of a thermoelectric cooler with direct water cooling, a commercially available microchannel-cooled thermoelectric cooler, and an integrated embedded manifold microchannel thermoelectric cooler was compared under steady-state conditions. The microchannel flow rate was kept constant at 100 mL / min, and the hotspot power density increased from 454.4 W / cm². 2 Gradually increase by 113.6 W / cm 2 By varying the current in the thermoelectric cooler, the hotspot temperature was adjusted to reach the lowest achievable temperature at that hotspot power density. Results showed that, under steady-state conditions, the integrated embedded manifold microchannel thermoelectric cooler exhibited the best hotspot cooling capability. The hotspot power density was 795.2 W / cm². 2At that time, the hot spot temperatures of the directly water-cooled thermoelectric cooler, the commercially available microchannel-cooled thermoelectric cooler, and the integrated embedded manifold microchannel thermoelectric cooler were 118.03℃, 102.50℃, and 63.21℃, respectively. Compared to the commercially available microchannel-cooled thermoelectric cooler, the integrated embedded manifold microchannel thermoelectric cooler reduced the interfacial thermal resistance, thus reducing the hot spot temperature by 39.29℃. Compared to the directly water-cooled thermoelectric cooler, the integrated embedded manifold microchannel thermoelectric cooler added a microchannel structure, enhancing fluid heat transfer at the hot end of the thermoelectric cooler, and reducing the hot spot temperature by 54.82℃.

[0072] Please see Figure 13 The hotspot power density remains at 681.6 W / cm². 2 With the microchannel flow rate gradually increased from 25 mL / min, the hotspot temperature was adjusted to the lowest achievable temperature at that flow rate by varying the thermoelectric cooler current. Results showed that the integrated embedded manifold microchannel thermoelectric cooler exhibited optimal hotspot cooling performance across the entire flow range. At a microchannel flow rate of 200 mL / min, the hotspot temperature of the integrated embedded manifold microchannel thermoelectric cooler was reduced by 43.74 °C compared to a directly water-cooled thermoelectric cooler, and by 34.61 °C compared to a commercially available microchannel-cooled thermoelectric cooler.

[0073] Please see Figure 14 , Figure 15 and Figure 16 , Figure 14 In this context, A represents the hotspot power density provided in the embodiments of the present invention, ranging from 227.26 W / cm². 2 The step increase was 340.89 W / cm². 2 The graph shows the change in hot spot temperature over time. Direct water-cooled thermoelectric coolers and commercial microchannel-cooled thermoelectric coolers cannot restore the hot spot temperature to its initial temperature by changing the thermoelectric cooler current, while the integrated embedded manifold microchannel thermoelectric cooler can restore the hot spot temperature to its initial temperature within 1.5 seconds by changing the current. Figure 14 In the diagram, B represents the relationship between the step change in hotspot power density and the maximum hotspot temperature change provided in this embodiment of the invention. The hotspot power density change is less than 284.08 W / cm². 2 At that time, all three cooling modules were able to restore the hotspot temperature, with minimal difference in the maximum change in hotspot temperature. However, when the change in hotspot power density exceeded 284.08 W / cm², the temperature remained relatively stable. 2 At this time, direct water-cooled thermoelectric coolers and commercial microchannel-cooled thermoelectric coolers cannot achieve hotspot temperature recovery, and the maximum temperature change during hotspot power changes will increase significantly. When the hotspot power density change value is 340.89 W / cm²,... 2At that time, the maximum temperature change of the integrated embedded manifold microchannel thermoelectric cooler was reduced by 75% and 57% compared to the direct water-cooled thermoelectric cooler and the commercial microchannel-cooled thermoelectric cooler, respectively.

[0074] Figure 15 In this context, A represents the baseline hotspot power density of 227.26 W / cm² provided in this embodiment of the invention. 2 The pulse increased by 340.89 W / cm. 2 A line graph showing the hotspot temperature change over time (lasting 5 seconds). Direct water-cooled thermoelectric coolers and commercially available microchannel-cooled thermoelectric coolers cannot restore the hotspot temperature to its initial temperature by changing the current within a 5-second pulse duration. However, the integrated embedded manifold microchannel thermoelectric cooler can restore the hotspot temperature to its initial temperature by changing the current. Figure 15 In the figure, B represents the relationship between the pulse amplitude of the hotspot power density and the maximum hotspot temperature change provided in this embodiment of the invention. The hotspot power density change value is less than 284.08 W / cm². 2 At this time, all three cooling modules can recover the hot spot temperature within the pulse duration. The maximum temperature change occurs when the hot spot power density drops from the pulse value to the baseline, at which point the hot spot temperature decreases due to the delay of the thermoelectric cooler. However, when the hot spot power density change exceeds 284.08 W / cm², the temperature remains stable. 2 At this time, direct water-cooled thermoelectric coolers and commercial microchannel-cooled thermoelectric coolers cannot achieve hot spot temperature recovery within the pulse duration. This excess temperature above the initial temperature will partially offset the delay of the thermoelectric cooler, resulting in a temperature drop. Therefore, the integrated embedded manifold microchannel thermoelectric cooler experiences greater undercooling at the end of the pulse compared to the other two, but the maximum temperature change is still significantly lower than the maximum temperature change during the entire hot spot power density pulse change. The hot spot power density change value is 340.89 W / cm². 2 At that time, the maximum temperature change of the integrated embedded manifold microchannel thermoelectric cooler was reduced by 62% and 34% compared to the direct water-cooled thermoelectric cooler and the commercial microchannel-cooled thermoelectric cooler, respectively.

[0075] Figure 16 In this context, A represents the hotspot power density provided by the embodiment of the invention, from a baseline of 227.26 W / cm². 2 The occurrence period is 4 seconds, and the power change amplitude is 227.26 W / cm². 2 The graph shows the change in hotspot temperature over time as the square wave intensity increases. The thermoelectric cooler with integrated embedded manifold microchannel exhibits a smaller maximum temperature change during the pulsed power density square wave variation compared to directly water-cooled thermoelectric coolers and commercially available microchannel-cooled thermoelectric coolers. Figure 16B in the figure is the relationship between the square wave variation period of the hot spot power density and the maximum hot spot temperature variation. The maximum temperature variation of the three cooling modules decreases with the square wave variation period, and the maximum temperature variation of the thermoelectric cooler with integrated embedded manifold microchannel is smaller than that of the thermoelectric cooler with direct water cooling and the thermoelectric cooler with commercial microchannel cooling throughout the entire period.

[0076] As can be seen from the above steady-state and dynamic experiments, the thermoelectric cooler with integrated embedded manifold microchannels eliminates the interfacial thermal resistance between the microchannel and the thermoelectric cooler. At the same time, the structure of the manifold embedded microchannel increases the heat exchange area and enhances fluid turbulence compared to direct water cooling. The two work together to enhance the heat exchange at the hot end of the thermoelectric device and improve the cooling performance of the combined thermoelectric microchannel cooling.

[0077] In addition to the DC-channel type embedded microchannels described above, the following embedded microchannels can be prepared using the method for preparing embedded manifold microchannels for enhanced thermoelectric coolers described in any of the above embodiments, including but not limited to: S-channel type embedded microchannels and micro-column type embedded microchannels.

[0078] Please see Figure 17 The S-channel embedded microchannel consists of 25 S-shaped channels, each channel being formed by multiple arcs with a radius R2 = 0.94 mm and an angle θ = 50°; the length of each channel is L. 21 =5mm, width W2 =0.1mm, channel spacing S2 =0.1mm, total width L of channel area 22 =5mm, and the channel depth is 0.2mm.

[0079] Please see Figure 18 The total channel length L of the micro-pillar embedded microchannel 31 =5mm, width L 32 =5mm, with 25×25 square micropillars with side length W3=0.1mm inside, micropillar spacing S2=0.1mm, and channel area depth of 0.2mm.

[0080] In addition to the one-in-one-out manifold structure described above, the following liquid supply manifold structures can be prepared by the embedded manifold microchannel preparation method for enhanced thermoelectric coolers described in any of the above embodiments, including but not limited to: one-in-two-out manifold structure.

[0081] Please see Figure 19 , Figure 20 and Figure 21 The base of the liquid supply manifold structure is square, with a side length L. M31 =50mm, height H M31 =16.5mm. The top of the manifold has a long L-shaped section. M32 =8mm, width W M31 =8mm, depth HM32 A 0.4mm groove is used to position the manifold and connect it to the embedded microchannel of the thermoelectric cooler's hot-end substrate. This one-in-two-out liquid supply manifold structure has three connecting pipes for supplying liquid to the embedded microchannel. Each connecting pipe consists of a vertical rectangular pipe segment connected to a horizontal circular pipe segment. The middle connecting pipe is the liquid supply connection pipe for fluid inflow into the microchannel, and the two side connecting pipes are the liquid outlet connection pipes for fluid outflow from the microchannel. The rectangular cross-section of the three vertical pipes has a length of L. M33 =5mm, equal to the total width of the embedded microchannel; the width of the rectangular cross-section is W M32 =1mm; the total width of the three rectangular flow channels is W M33 =5mm, equal to the total width of the embedded microchannel. The vertical pipe length of the liquid inlet connection pipe is H. M33 =6mm, the vertical pipe length of the outlet connection pipe is H M34 = 8.5mm. The diameter range of the horizontal pipes connecting the three pipes is D. M31 =5mm, the outer diameter of the horizontal pipe outside the base is D M32 =7mm. Fluid enters the embedded microchannel from the central supply connection tube and then flows out from the outlet connection tubes on both sides. The supply structure has four diameter W sections around its perimeter. M33 A 6mm hole is used to secure the entire cooling system to the test platform.

[0082] In addition to the above-mentioned combination of DC-channel embedded microchannel and one-in-one-out manifold structure, these three types of embedded microchannels—DC-channel embedded microchannel, S-channel embedded microchannel, and micro-column embedded microchannel—can be combined with the two types of liquid supply manifold structures to form one-in-one-out manifold structure or one-in-two-out manifold structure in any combination.

[0083] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A thermoelectric device with integrated embedded microchannels, characterized in that: A thermoelectric device with integrated embedded microchannels, characterized in that: The device includes a liquid supply manifold structure and a thermoelectric cooler connected together. A microchannel structure is directly formed on the hot end substrate of the thermoelectric cooler to achieve integration of the microchannel structure and the thermoelectric cooler. The liquid supply manifold structure includes at least two connecting pipes, which are respectively connected to the microchannel structure to form a liquid flow channel for the cooling medium to pass through. The connecting pipes include vertically connected vertical pipes and horizontal pipes, wherein each connecting pipe is composed of a rectangular pipe segment that is perpendicular to each other and a horizontal circular pipe segment connected together. The vertical pipe is the rectangular pipe segment, and the horizontal pipe is the circular pipe segment.

2. The thermoelectric device with integrated embedded microchannels as described in claim 1, characterized in that: The manifold liquid supply structure includes two connecting pipes, which are respectively connected to the inlet and outlet of the microchannel structure.

3. The thermoelectric device with integrated embedded microchannels as described in claim 1, characterized in that: The manifold liquid supply structure includes three connecting pipes, one of which is connected to the inlet of the microchannel structure, and the other two connecting pipes are respectively connected to the outlet of the microchannel structure.

4. The thermoelectric device with integrated embedded microchannels as described in claim 1, characterized in that: The microchannel structure consists of parallel rectangular channels with a channel length ranging from 3 mm to 6 mm, a channel depth ranging from 50 μm to 500 μm, a channel width ranging from 20 μm to 300 μm, a channel spacing ranging from 20 μm to 200 μm, and a number ranging from 5 to 50.

5. The thermoelectric device with integrated embedded microchannels as described in claim 1, characterized in that: The microchannel structure is a parallel S-shaped channel. The channel trajectory is composed of multiple arcs with diameters ranging from 30 μm to 200 μm, channel depths ranging from 50 μm to 500 μm, channel widths ranging from 20 μm to 200 μm, channel spacing ranging from 40 μm to 200 μm, and the number of channels ranging from 5 to 50.

6. The thermoelectric device with integrated embedded microchannels as described in claim 1, characterized in that: The microchannel structure is a square needle-rib structure with a needle-rib height ranging from 50 μm to 500 μm, a needle-rib side length and width ranging from 20 μm to 200 μm, and a needle-rib spacing ranging from 20 μm to 200 μm.

7. A method for fabricating an integrated embedded microchannel thermoelectric device according to any one of claims 1-6, characterized in that: Channels are etched on the hot end substrate of the thermoelectric cooler, and the channels serve as microchannel structures.

8. A hotspot dynamic thermal management temperature measurement system, characterized in that: The temperature measurement system includes a liquid supply circuit, a data acquisition and control system, and a thermoelectric device with an integrated embedded microchannel as described in any one of claims 1-6, wherein the thermoelectric device is connected to the liquid supply circuit and the data acquisition and control system.

Images