Integrated embedded micro-channel thermoelectric device and preparation method and application thereof

Abstract

The invention belongs to the related technical field of heat management of electronic devices, and discloses a thermoelectric device of an integrated embedded micro-channel and a preparation method and application of the thermoelectric device, the device comprises a liquid supply manifold structure and a thermoelectric refrigerating unit which are connected, a micro-channel structure is formed on a hot end substrate of the thermoelectric refrigerating unit, and the micro-channel structure is arranged on the hot end substrate of the thermoelectric refrigerating unit. The liquid supply manifold structure comprises at least two connecting pipelines, and the at least two connecting pipelines are respectively connected with the micro-channel structure and form a liquid channel for a cooling medium to pass through. According to the device, the interface thermal resistance between the thermoelectric refrigerating unit and the micro-channel radiator can be removed, the cooling performance of the thermoelectric micro-channel is improved, and the functions of accurate temperature control of hot spots, rapid response of dynamic thermal loads and overall efficient cooling are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to thermal management of electronic devices, and more specifically, relates to a thermoelectric device with integrated embedded microchannels and a preparation method and application thereof. Background Art

[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 of the devices. At the same time, with the continuous integration of electronic devices, the space for heat dissipation is getting smaller and smaller, while the heat flux density of the devices is getting larger and larger, and even hot spots with local heat flux densities as high as hundreds or even 1000W / cm2 appear. When the device switches from a low-power operating state to a high-power operating state, these hot spots will experience a huge temperature rise. Therefore, efficient dynamic thermal management of local hot spots in a limited space is the key to ensuring reliable and stable operation of temperature-sensitive electronic devices.

[0003] Based on the Peltier effect, thermoelectric cooling devices transfer heat from the cold end to the hot end under the drive of DC current, which can effectively control the hot spot temperature of temperature-sensitive electronic devices, and have the advantages of controllable size, fast response, and high reliability. However, the hot end of the thermoelectric device requires an efficient heat sink to ensure the cooling performance of the cold end of the thermoelectric device. Among various heat sinks, microchannel radiators are widely used for heat dissipation of electronic devices in limited spaces due to their compact structure and high heat transfer coefficient. Therefore, using microchannel radiators to efficiently dissipate heat from the hot end of the thermoelectric cooler is expected to achieve dynamic thermal management of hot spots in temperature-sensitive electronic devices.

[0004] Improving the cooling performance of thermoelectric microchannels can be achieved by optimizing thermoelectric cooling devices and increasing the maximum cooling power of thermoelectric cooling devices, such as reducing the thickness of the thermoelectric arm and increasing the thermoelectric figure of merit of the thermoelectric material, but this requires complex processes and high costs. In addition, the cooling performance of thermoelectric microchannels can also be improved by enhancing the heat exchange capacity of the hot end of the thermoelectric cooling device, such as optimizing the flow channel structure in the microchannel heat sink. In addition, optimizing the connection between the thermoelectric device and the microchannel heat sink is also the key to improving the cooling capacity of the system. The two devices are usually connected using traditional thermal interface materials such as thermal grease and solder. The thermal interface thermal resistance can even 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 defects or improvement needs of the prior art, the present invention provides a thermoelectric device with integrated embedded microchannel and a preparation method and application thereof, which aims to solve the problem of how to improve the refrigeration performance of the microchannel structure of the thermoelectric refrigeration device.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present invention, a thermoelectric device with integrated embedded microfluidic channels is provided, wherein the device comprises a liquid supply manifold structure and a thermoelectric cooler connected to each other, a microfluidic channel structure is formed on the hot end substrate of the thermoelectric cooler, and the liquid supply manifold structure comprises at least two connecting pipes, at least two of the connecting pipes are respectively connected to the microfluidic channel structure to form a liquid flow channel for the cooling medium to pass through.

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

[0008] Furthermore, the manifold liquid supply structure includes two connecting pipes, and the two connecting pipes are respectively connected to the inlet and the 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 microfluidic channel structure, and the other two connecting pipes are respectively connected to the outlets of the microfluidic channel structure.

[0010] Furthermore, the microfluidic channel structure is a parallel rectangular channel 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.

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

[0012] Furthermore, the microchannel structure is a square pin-fin structure, the pin-fin height ranges from 50 μm to 500 μm, the pin-fin side length and width ranges from 20 μm to 200 μm, and the pin-fin spacing ranges from 20 μm to 200 μm.

[0013] The present invention also provides a method for preparing the thermoelectric device with integrated embedded microchannel as described above, wherein a groove is etched on a hot end substrate of the thermoelectric cooler, and the groove is used as a microchannel structure.

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

[0015] In general, compared with the prior art, the above technical solutions conceived by the present invention mainly have the following advantages in the thermoelectric device with integrated embedded microchannel and its preparation method and application:

[0016] Beneficial effects:

[0017] 1. A microchannel structure is formed on the hot end substrate of the thermoelectric cooler, thereby realizing the integration of the microchannel and the thermoelectric cooler, which not only reduces the demand for heat dissipation space, but also eliminates the interface thermal resistance between the microchannel heat sink and the thermoelectric cooler, improves the cooling performance of the thermoelectric microchannel, and realizes precise temperature control of hot spots, rapid response to dynamic heat loads and overall efficient cooling functions.

[0018] 2. The combination of the liquid supply manifold structure and the microchannel structure can strengthen the jet impact and mixing disturbance of the body, enhance the heat exchange capacity of the microfluid, and enhance the temperature control ability of the thermoelectric microchannel on the hot spot.

[0019] 3. The experiment also verified that the thermoelectric cooler with integrated embedded manifold microchannel eliminated the interfacial thermal resistance between the microchannel and the thermoelectric cooler. At the same time, the structure of the manifold embedded microchannel increased the heat exchange area and enhanced the fluid disturbance compared with direct water cooling. The two worked together to strengthen the heat exchange at the hot end of the thermoelectric device and improve the cooling performance of the thermoelectric microchannel combined cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of a method for preparing a thermoelectric device with integrated embedded microfluidic channel provided by the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of a thermoelectric device with integrated embedded microfluidic channels provided by the present invention;

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

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

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

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

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

[0027] Figure 8Schematic diagram of a one-inlet-one-outlet direct water-cooled heat sink provided by an embodiment of the present invention;

[0028] Fig. 9 is a top view of a one-inlet-one-outlet direct water-cooled heat sink provided by an embodiment of the present invention;

[0029] Fig.10 is a side view of a one-inlet-one-outlet direct water-cooled heat sink provided by an embodiment of the present invention;

[0030] Fig.11 is a schematic diagram of a hotspot dynamic thermal management temperature measurement system provided by an embodiment of the present invention;

[0031] Fig.12 is a graph showing the relationship between hotspot power density and hotspot temperature provided by an embodiment of the present invention;

[0032] Fig.13 is a graph showing the relationship between flow rate and hot spot temperature provided by an embodiment of the present invention;

[0033] Fig.14 A and B are respectively a line graph of the hotspot temperature changing with time under a step change in the hotspot power density provided by an embodiment of the present invention and a relationship graph between the step change amplitude of the hotspot power density and the maximum hotspot temperature change;

[0034] Fig.15 A and B are respectively a line graph of the hotspot temperature changing with time under the hotspot power density pulse change provided by the embodiment of the present invention and a relationship graph between the hotspot power density pulse change amplitude and the maximum hotspot temperature change;

[0035] Fig.16 A and B are respectively a line graph of the hotspot temperature changing with time under the hotspot power density square wave change provided by the embodiment of the present invention and a relationship graph between the hotspot power density square wave change period and the maximum hotspot temperature change;

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

[0037] Fig.18 is a top view of a micro-column embedded microfluidic channel provided by an embodiment of the present invention;

[0038] Fig.19 is a schematic diagram of a one-inlet-two-outlet type liquid supply manifold structure provided by an embodiment of the present invention;

[0039] Fig. 20 is a top view of a one-inlet-two-outlet type liquid supply manifold structure provided by an embodiment of the present invention;

[0040] Fig.21 It is a side view of a one-inlet-two-outlet type liquid supply manifold structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] The present invention provides a thermoelectric device with integrated embedded microfluidic channels, which can remove the interfacial thermal resistance between a thermoelectric cooler and a microfluidic channel heat sink, improve the cooling performance of the thermoelectric microfluidic channel, and achieve precise temperature control of hot spots, rapid response to dynamic heat loads, and overall efficient cooling functions.

[0043] The device includes a liquid supply manifold structure and a thermoelectric cooler connected to each other. 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. At least two of the connecting pipes are respectively connected to the microchannel structure to form a liquid flow channel for cooling medium to pass through.

[0044] The connecting pipes include vertical pipes and horizontal pipes connected vertically. In one embodiment, the manifold liquid supply structure has two connecting pipes, each of which is composed of a rectangular pipe section perpendicular to each other and a horizontal circular pipe section. The length of the vertical pipe cross section rectangle ranges from 3mm to 6mm, the width ranges from 0.5mm to 1mm, and the pipe length ranges from 5mm to 10mm. The diameter range of the horizontal pipe is 2mm to 5mm, and the pipe length ranges from 5mm to 10mm. The fluid enters the embedded microchannel from one connecting pipe and flows out from another connecting pipe.

[0045] In another embodiment, the manifold liquid supply structure has three connecting pipes, each of which is composed of a vertical rectangular pipe section connected to a horizontal circular pipe section. The vertical pipe cross-section rectangular length ranges from 3 to 6 mm, the width ranges from 0.5 to 1 mm, and the pipe length ranges from 5 to 10 mm. The horizontal pipe diameter ranges from 2 to 5 mm, and the pipe length ranges from 5 to 10 mm. The fluid enters the embedded microchannel from the middle connecting pipe and flows out from the two connecting pipes on both sides.

[0046] In one embodiment, the microfluidic channel structure is a parallel rectangular channel 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.

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

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

[0049] See also Figure 1 The present invention also provides a method for preparing the thermoelectric device with integrated embedded microfluidic channel as described above, the preparation method mainly comprises the following steps:

[0050] S101, etching a groove on the hot end substrate of the thermoelectric cooler, the groove being used as a microfluidic structure to realize the integration of the microchannel and the thermoelectric cooler. Specifically, the groove can be prepared on the hot end substrate of the thermoelectric cooler by laser etching, plasma etching or mechanical processing.

[0051] S102, processing a liquid supply manifold structure on a metal or ceramic substrate. The distribution of the liquid supply manifold structure needs to be coordinated with the embedded microchannel structure to keep the cooling working medium flowing from the manifold inlet through the microchannel embedded in the thermoelectric cooler and then flowing out from the manifold outlet. Specifically, the liquid supply manifold structure can be prepared by mechanical processing or 3D printing.

[0052] S103, after fixing the thermoelectric cooler with embedded microfluidic channels 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 two parts with epoxy resin glue at the junction, or to weld and connect the thermoelectric cooler with etched microchannels and the manifold microchannel substrate after metallization pretreatment before fixing.

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

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

[0055] Furthermore, the laser frequency and power of the laser etching equipment are adjusted to perform groove etching on the hot end substrate of the thermoelectric cooler. For example, nanosecond laser etching technology is used to expose a two-dimensional groove structure pattern on the hot end substrate of the thermoelectric cooler to be prepared according to the laser scanning sequence to prepare an embedded microfluidic channel.

[0056] The laser etching technology here can use a variety of laser types, such as femtosecond laser, picosecond laser, nanosecond laser, etc. Different types of lasers will leave different structural morphologies on the surface after etching the groove structure. For example, the groove wall surface etched by nanosecond laser has a larger inclination. Therefore, during actual laser etching, the specific laser frequency and power should be selected according to the actual situation.

[0057] Taking the plasma etching method as an example, in some specific embodiments, step S101 specifically includes: using deionized water, isopropanol or acetone to sequentially clean the hot end substrate of the thermoelectric cooler, and using nitrogen to blow dry the substrate after removing the pollutants on the surface. Spin a layer of photoresist on the substrate, and control the rotation speed and time to obtain the required thickness of the glue layer. The substrate coated with photoresist is pre-baked in a hot plate or an oven to remove the solvent in the photoresist. Using an ultraviolet exposure machine, the designed groove mask pattern is projected onto the photoresist layer. The exposed substrate is immersed in a developer, and the time and conditions are determined according to the type and thickness of the photoresist. After development, rinse with deionized water to remove the residual developer. Bake in an oven to enhance the corrosion resistance and adhesion of the photoresist. Use a plasma etcher to etch the ceramic substrate, adjust the flow rate of each etching gas, and the plasma generates the required radio frequency power and etching time. During the etching process, the substrate can be cooled on the back to prevent overheating. Subsequently, the residual photoresist is removed and the substrate is cleaned.

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

[0059] Taking mechanical processing as an example, in some specific embodiments, step S102 specifically includes the following steps: according to the designed liquid supply manifold structure, use a common lathe, a CNC lathe, etc. to process the base material 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: using 3D design software to design the liquid supply manifold structure, and then slicing the 3D structure model to obtain a set of 2D structure images. Select suitable metal powder, for example, stainless steel, aluminum alloy and other metal 3D printing powders. Calibrate the flatness and alignment of the printing platform, and evenly lay the metal powder on the printing platform through the powder supply system. The laser in the printing device scans the metal powder according to the path generated by the slicing software, melts it and solidifies it layer by layer. This process is repeated until all layers of the liquid supply manifold structure are printed.

[0061] Taking epoxy resin connection as an example, in some specific embodiments, step S103 specifically includes the following steps: clamping the embedded microchannel thermoelectric cooler prepared in step S101 and the liquid supply manifold structure prepared in step S102 with a clamp, then applying epoxy resin glue at the junction, and letting it stand for a period of time to allow the epoxy resin glue to solidify.

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

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

[0064] The present application also provides an embedded manifold microchannel structure on the hot end substrate of a thermoelectric cooler, wherein the structure is obtained by a method for preparing a thermoelectric cooler with integrated embedded manifold microchannels as described in any of the above embodiments, and for example includes: a thermoelectric cooler with an integrated one-in-one-out manifold direct flow channel type embedded microchannel for cooling long strip hot spots.

[0065] See also Figure 2 The liquid supply manifold structure is a one-in-one-out liquid supply method, the embedded microfluidic channel is a straight-channel embedded microfluidic channel, and the liquid supply manifold structure and the thermoelectric cooler of the embedded microfluidic channel are fixedly connected by applying epoxy resin glue at the junction. The long strip simulation hotspot chip is 1.6mm long, 0.55mm wide, and 0.4mm high, and is used to simulate the high heat flux hotspot heating of electronic devices. Nano-silver glue is used to bond the simulation hotspot chip to the thermoelectric cooler. Specifically, a thin and uniform layer of nano-silver glue is applied on the cold end substrate of the thermoelectric cooler with integrated embedded manifold microchannel, and the simulation hotspot chip is placed on the silver glue, fixed with a clamp, and placed in a 100°C constant temperature box for curing for 2 hours.

[0066] See also Figure 3 and Figure 4 The straight channel embedded microfluidic channel consists of 25 rectangular channels. The length of each channel is L 11 =5mm, width W1 = 0.1mm. Slot spacing S1 = 0.1mm, total slot area width L 12 =5mm, groove depth H1 =0.2mm.

[0067] See also Figure 5 , Figure 6 and Figure 7 The base of the liquid supply manifold structure is a square with a side length of L M11 =50mm, height H M11 =11.5mm. There is a long L on the top of the liquid supply manifold structure. M12 =8mm, width W M11 =8mm, depth H M12 =0.4mm groove, used to locate the liquid supply manifold structure and the embedded microchannel of the hot end substrate of the thermoelectric cooler. The one-in-one-out type liquid supply manifold structure has two connecting pipes for supplying liquid to the embedded microchannel, each connecting pipe is composed of a vertical rectangular pipe section connected to a horizontal circular pipe section. The length of the vertical pipe cross section rectangle is L M13 =5mm, and the total width of the embedded microchannel L 12 equal; the width of the cross-sectional rectangle is W M12 =1mm; the total width of the two rectangular flow channel openings is W M13 =5mm, and the total width of the embedded microchannel L 11 Equal; vertical pipe length is H M13 =6mm. The horizontal pipe diameter range is D M11 =5mm, the outer diameter of the horizontal pipe outside the base is D M12 =7mm. The 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 =6mm holes are used to fix the entire cooling system on the test platform.

[0068] In order to compare the improvement of the cooling performance of thermoelectric coolers by integrating embedded manifold microchannels, a thermoelectric cooler with direct water cooling and a thermoelectric cooler with commercial microchannel cooling were prepared. The three have the same simulated hotspot chip and thermoelectric cooler.

[0069] See also Figure 8 , Fig. 9 and Fig.10 The base of the direct water-cooled heat sink is a square with a side length of L M21 =50mm, height H M21 =11.5mm. There is a long L on the top of the direct water cooling heat sink. M22 =8mm, width W M21 =8mm, depth H M22 =0.4mm groove, used to locate the direct water cooling heat sink and the hot end substrate of the thermoelectric cooler. The one-in-one-out direct water cooling heat sink has a horizontal cooling section and two connecting pipes, each connecting pipe is composed of a vertical rectangular pipe section connected to a horizontal circular pipe section. The length of the horizontal cooling section LM23 =5mm, width W M22 =5mm, depth H M23 =0.2mm. The length of the vertical pipe cross-section rectangle is equal to the horizontal cooling section, and the width of the cross-section rectangle is W M23 =1mm, the vertical pipe length is H M24 =6mm. The diameter range of horizontal circular pipe is D M21 =5mm, the outer diameter of the horizontal circular pipe outside the base is D M22 =7mm. The fluid enters the horizontal cooling section from one connecting pipe and flows out from another connecting pipe. The four diameters W around the liquid supply structure M23 =6mm holes are used to fix the entire cooling module on the test platform.

[0070] See also Fig.11 The present invention also provides a hotspot 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, wherein the thermoelectric device connects the liquid supply circuit and the data acquisition and control system. The liquid supply circuit is composed of a water storage tank, a high-precision circulation pump, a flow meter, a filter, a heat exchanger, and a chiller. The liquid supply circuit uses deionized water as a cooling medium, and can control the coolant to enter the microchannel at a predetermined temperature and flow rate. The data acquisition and control system is composed 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 the set program, and collect the actual microchannel flow rate, module inlet and outlet pressure loss, and hotspot temperature in real time.

[0071] See also Fig.12 and Fig.13 The cooling performance of a thermoelectric cooler with direct water cooling, a thermoelectric cooler with commercial microchannel cooling, and a thermoelectric cooler with integrated embedded manifold microchannels was compared under steady state conditions. The microchannel flow rate was kept constant at 100 mL / min, and the hot spot power density increased from 454.4 W / cm 2 Gradually increase to 113.6W / cm 2 The hot spot temperature is made to reach the lowest temperature that can be achieved under the hot spot power density by changing the current of the thermoelectric cooler. The results show that in steady state, the thermoelectric cooler with integrated embedded manifold microchannel exhibits the best hot spot cooling capability. The hot spot power density is 795.2W / cm 2When the temperature of the thermoelectric cooler with direct water cooling, the thermoelectric cooler with commercial microchannel cooling, and the thermoelectric cooler with integrated embedded manifold microchannel are 118.03℃, 102.50℃, and 63.21℃, respectively. Compared with the thermoelectric cooler with commercial microchannel cooling, the thermoelectric cooler with integrated embedded manifold microchannel reduces the interface thermal resistance and reduces the hot spot temperature by 39.29℃. Compared with the thermoelectric cooler with direct water cooling, the thermoelectric cooler with integrated embedded manifold microchannel increases the microchannel structure, strengthens the fluid heat exchange at the hot end of the thermoelectric cooler, and reduces the hot spot temperature by 54.82℃.

[0072] See also Fig.13 , the hot spot power density remains at 681.6W / cm 2 The microchannel flow rate was gradually increased from 25 mL / min. The hot spot temperature was made to reach the lowest temperature achievable at the microchannel flow rate by changing the current of the thermoelectric cooler. The results show that the thermoelectric cooler with integrated embedded manifold microchannel exhibits the best hot spot cooling performance in the whole flow range. When the microchannel flow rate is 200 mL / min, the hot spot temperature of the thermoelectric cooler with integrated embedded manifold microchannel is reduced by 43.74°C and 34.61°C respectively compared with the thermoelectric cooler with direct water cooling and the thermoelectric cooler with commercial microchannel cooling.

[0073] See also Fig.14 , Fig.15 and Fig.16 , Fig.14 A is the hot spot power density provided by the embodiment of the present invention from 227.26W / cm 2 Step increase 340.89W / cm 2 The line graph of the hot spot temperature changing with time is shown in Figure 2. The direct water-cooled thermoelectric cooler and the commercial microchannel-cooled thermoelectric cooler cannot restore the hot spot temperature to the initial temperature by changing the thermoelectric cooler current, while the thermoelectric cooler with integrated embedded manifold microchannel can restore the hot spot temperature to the initial temperature within 1.5 seconds by changing the current. Fig.14 B is a graph showing the relationship between the step change amplitude of the hotspot power density and the maximum hotspot temperature change provided by the embodiment of the present invention. 2 When the hotspot power density change value is greater than 284.08W / cm 2 When the hotspot power density changes, the direct water-cooled thermoelectric cooler and the commercial microchannel-cooled thermoelectric cooler cannot achieve hotspot temperature recovery, and the maximum temperature change when the hotspot power changes will increase significantly. 2When the temperature is adjusted, the maximum temperature change of the thermoelectric cooler with integrated embedded manifold microchannel is reduced by 75% and 57% compared with the thermoelectric cooler with direct water cooling and the thermoelectric cooler with commercial microchannel cooling, respectively.

[0074] Fig.15 A is the hotspot power density baseline 227.26 W / cm provided in the embodiment of the present invention. 2 Pulse increase 340.89W / cm 2 The line graph of the hot spot temperature changing with time when the pulse duration is 5 seconds. For the thermoelectric cooler with direct water cooling and the thermoelectric cooler with commercial microchannel cooling, changing the current of the thermoelectric cooler cannot restore the hot spot temperature to the initial temperature within the pulse duration of 5 seconds, while the thermoelectric cooler with integrated embedded manifold microchannel can restore the hot spot temperature to the initial temperature by changing the current. Fig.15 B is a graph showing the relationship between the hotspot power density pulse variation amplitude and the maximum hotspot temperature variation provided by an embodiment of the present invention. 2 When the hotspot power density changes more than 284.08W / cm 2 When the temperature of the hot spot is 0.040 W / cm2, the direct water-cooled thermoelectric cooler and the commercial microchannel-cooled thermoelectric cooler cannot achieve hot spot temperature recovery within the pulse duration. This value higher than the initial temperature will offset part of the delay of the thermoelectric cooler and cause the temperature to drop. Therefore, the supercooling of the thermoelectric cooler with integrated embedded manifold microchannel at the end of the pulse is greater than that of the other two, but the maximum temperature change is still significantly lower than the change of the entire hot spot power density pulse. The hot spot power density change value is 340.89 W / cm2. 2 When the temperature is adjusted, the maximum temperature change of the thermoelectric cooler with integrated embedded manifold microchannel is reduced by 62% and 34% compared with the thermoelectric cooler with direct water cooling and the thermoelectric cooler with commercial microchannel cooling, respectively.

[0075] Fig.16 A is the power density of the hot spot provided by the embodiment of the present invention from the baseline 227.26W / cm 2 The occurrence period is 4 seconds, and the power variation is 227.26W / cm 2 The line graph of the hot spot temperature changing with time when the square wave increases. The maximum temperature change of the thermoelectric cooler with integrated embedded manifold microchannel during the pulse power density square wave change is smaller than that of the thermoelectric cooler with direct water cooling and the thermoelectric cooler with commercial microchannel cooling. Fig.16B is the relationship between the square wave change cycle of the hot spot power density and the maximum hot spot temperature change. The maximum temperature change values ​​of the three cooling modules decrease with the square wave change cycle, and the maximum temperature change value of the thermoelectric cooler with integrated embedded manifold microchannel is smaller than that of the direct water-cooled thermoelectric cooler and the commercial microchannel cooled thermoelectric cooler in the entire cycle.

[0076] It can be seen from the above steady-state and dynamic experiments that the thermoelectric cooler with integrated embedded manifold microchannel 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 the fluid disturbance 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 thermoelectric microchannel combined cooling.

[0077] In addition to the above-mentioned straight channel type embedded microchannel, the following embedded microchannels can be prepared by the preparation method of the embedded manifold microchannel of the enhanced thermoelectric cooler described in any of the above embodiments, including but not limited to: S-channel type embedded microchannel, micro-column type embedded microchannel.

[0078] See also Fig.17 The S-channel embedded microchannel consists of 25 S-shaped grooves, which are composed of multiple arcs with a radius of R2 = 0.94 mm and an angle of θ = 50°; the length of each groove is L 21 =5mm, width W2 = 0.1mm, slot spacing S2 = 0.1mm, total slot area width L 22 =5mm, groove depth is 0.2mm.

[0079] See also Fig.18 , the total channel area length L of the micro-column embedded microfluidic channel 31 =5mm, width L 32 =5mm, with 25×25 square micro-pillars with a side length of W3=0.1mm inside, a micro-pillar spacing S2=0.1mm, and a groove area depth of 0.2mm.

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

[0081] See also Fig.19 , Fig. 20 and Fig.21 The base of the liquid supply manifold structure is a square with a side length of L M31 =50mm, height H M31 =16.5mm. There is a long L on the top of the manifold. M32 =8mm, width W M31 =8mm, depth HM32 =0.4mm groove, used to locate the manifold and the embedded microchannel of the hot end substrate of the thermoelectric cooler. The one-inlet and two-outlet type liquid supply manifold structure has three connecting pipes for supplying liquid to the embedded microchannel, each connecting pipe is composed of a vertical rectangular pipe section connected to a horizontal circular pipe section. Among the three connecting pipes, the middle one is the liquid supply connecting pipe for the fluid to flow into the microchannel, and the two sides are the liquid outlet connecting pipes for the fluid to flow out of the microchannel. The length of the rectangular cross section of the three vertical pipes is L M33 =5mm, which is equal to the total width of the embedded microchannel; the width of the cross-sectional rectangle is W M32 =1mm; the total width of the three rectangular flow channel openings is W M33 =5mm, which is equal to the total width of the embedded microchannel. The vertical length of the liquid inlet connection pipeline is H M33 =6mm, the vertical pipe length of the liquid outlet connecting pipe is H M34 =8.5mm. The horizontal pipe diameter range of the three connecting pipes is D M31 =5mm, the outer diameter of the horizontal pipe outside the base is D M32 =7mm. The fluid enters the embedded microchannel from the middle liquid supply connecting pipe and then flows out from the liquid outlet connecting pipes on both sides. M33 =6mm holes are used to fix the entire cooling system on the test platform.

[0082] In addition to the above-mentioned straight channel type embedded microfluidic channel and one-in-one-out manifold structure combination, these three types of embedded microfluidic channels: straight channel type embedded microfluidic channel, S-channel type embedded microfluidic channel, and micro-column type embedded microfluidic channel can be combined with two liquid supply manifold structures to form a one-in-one-out manifold structure or a one-in-two-out manifold structure.

[0083] It will be easily understood by those skilled in the art that the above description is only 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 in the protection scope of the present invention.

Claims

1. A thermoelectric device with integrated embedded microfluidic channel, characterized in that: The device includes a liquid supply manifold structure and a thermoelectric cooler connected to each other. 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. At least two of the connecting pipes are respectively connected to the microchannel structure to form a liquid flow channel for cooling medium to pass through.

2. The thermoelectric device with integrated embedded microfluidic channel according to claim 1, characterized in that: The connecting pipelines include vertical pipelines and horizontal pipelines that are vertically connected.

3. The thermoelectric device with integrated embedded microfluidic channel according to claim 1, characterized in that: The manifold liquid supply structure includes two connecting pipes, and the two connecting pipes are respectively connected to the inlet and the outlet of the microchannel structure.

4. The thermoelectric device with integrated embedded microfluidic channel according to claim 1, characterized in that: The manifold liquid supply structure includes three connecting pipes, one of which is connected to the inlet of the microfluidic channel structure, and the other two connecting pipes are respectively connected to the outlets of the microfluidic channel structure.

5. The thermoelectric device with integrated embedded microfluidic channel according to claim 1, characterized in that: 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.

6. The thermoelectric device with integrated embedded microfluidic channel according to claim 1, characterized in that: The microchannel structure is a parallel S-shaped channel, the channel track is composed of multiple arcs with a diameter range of 30μm-200μm, a channel depth range of 50μm-500μm, a channel width range of 20μm-200μm, a channel spacing range of 40μm-200μm, and a number range of 5-50.

7. The thermoelectric device with integrated embedded microfluidic channel according to claim 1, characterized in that: The microchannel structure is a square pin-fin structure, the pin-fin height ranges from 50 μm to 500 μm, the pin-fin side length and width ranges from 20 μm to 200 μm, and the pin-fin spacing ranges from 20 μm to 200 μm.

8. A method for preparing a thermoelectric device with integrated embedded microfluidic channels according to any one of claims 1 to 7, characterized in that: Grooves are etched on the hot end substrate of the thermoelectric cooler, and the grooves serve as microfluidic channel structures.

9. A hot spot dynamic thermal management temperature measurement system, characterized in that: The temperature measurement system comprises a liquid supply circuit, a data acquisition and control system, and a thermoelectric device with an integrated embedded microfluidic channel as claimed in any one of claims 1 to 7, wherein the thermoelectric device connects the liquid supply circuit and the data acquisition and control system.

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