TEC composite structure integrating microchannels and series enhanced thermoelectric arm array and method of manufacture

Abstract

This invention discloses a TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array, and its fabrication method. The structure includes: a first thermally conductive layer and a second thermally conductive layer, both with liquid flow microchannels on their outer surfaces; a first electrode layer located on the inner surface of the first thermally conductive layer; a second electrode layer located on the inner surface of the second thermally conductive layer; and multiple TEC units located between the first and second electrode layers. Each TEC unit includes P-type thermoelectric arms, N-type thermoelectric arms, and suspended thermoelectric arms. The P-type and N-type thermoelectric arms are arranged alternately. The suspended thermoelectric arms are suspended between the P-type and N-type thermoelectric arms and include P-type and N-type thermionic arms. Connections between the P-type and N-type thermoelectric arms, between the N-type and P-type thermoelectric arms, and between the P-type and N-type thermoelectric arms are all achieved through metallic materials. This invention simultaneously achieves ultra-strong hot-end heat dissipation, ultra-low thermal bypass leakage, and high interface reliability in TEC.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit technology, specifically relating to a TEC (Thermoelectric Cooler) composite structure integrating microchannels and a series-enhanced thermoelectric arm array, and its fabrication method. Background Technology

[0002] Thermoelectric coolers (TECs) are based on the Peltier effect, using direct current to drive P-type and N-type semiconductor thermoelectric arms to generate a temperature difference, achieving active and precise solid-state cooling. This technology has outstanding advantages such as no moving parts, compact size, fast response speed, and high temperature control accuracy, and has been widely used in fields such as temperature control of optical communication lasers, low-temperature storage in biomedicine, and hotspot cooling of electronic equipment.

[0003] In recent years, with the rapid development of technologies such as 5G communication, high-performance computing, artificial intelligence chips, and high-power lasers, the power density of electronic devices and systems has continued to rise, making the problem of localized hotspot heat dissipation increasingly severe. This has brought broad application prospects to thermoelectric technologies (TECs) capable of achieving targeted and enhanced cooling, while also posing unprecedented challenges to their cooling performance and reliability. Traditional TEC structures face two main bottlenecks in high heat flux density applications: 1. Insufficient heat dissipation at the hot end limits cooling performance: Traditional TECs use alumina ceramic substrates as the hot-end heat dissipation interface, which has limited thermal conductivity (approximately 30 W / mK) and multiple interfacial thermal resistances with the heat sink. When the heat flux density at the hot end exceeds a certain threshold, heat accumulates at the hot end, causing the hot end temperature to rise, the cooling temperature difference to decrease sharply, and even a "thermal runaway" phenomenon where the hot end temperature is higher than the cold end, severely restricting the application of TECs in high power density scenarios.

[0004] 2. The thermal bypass effect severely reduces effective cooling efficiency: Traditional thermoelectric generators (TECs) use epoxy resin or aerogel to fill the gaps between their thermoelectric arms. Although the thermal conductivity of the filling material is low (0.02-0.2 W / mK), heat conduction still occurs, and the substrate material forms additional thermal bypass paths. This thermal bypass effect causes heat to leak directly from the hot end to the cold end, significantly offsetting the cooling capacity generated by the Peltier effect. This results in the actual cooling temperature difference and thermoelectric conversion efficiency being far below the material's theoretical limit, making it difficult to meet the deep cooling requirements of high-power-density chips. Studies have shown that thermal bypass can reduce actual cooling efficiency by 30%-50%, and the effective cooling temperature difference is far below the material's theoretical limit. To address these challenges, the industry has developed integrated thermoelectric coolers with microchannel heat dissipation. This approach abandons the traditional passive cooling method that relies on external heat sinks. Instead, it directly fabricates microchannel structures (typically 50-200 μm wide and 100-500 μm deep) on the upper surface or inside the ceramic substrate of the TEC hot end, integrating a fluid-sealed structure to form a built-in microchannel thermally conductive layer. When the TEC is operating, coolant (usually deionized water or a specialized coolant) is pumped into these microchannels, actively removing waste heat generated by the thermoelectric arm through forced convection heat transfer. This design significantly enhances the heat dissipation capacity of the hot end, reducing the hot end thermal resistance by more than an order of magnitude, enabling the TEC to handle heat flux densities exceeding 100 W / cm² or even higher. This effectively alleviates the problem of heat accumulation at the hot end, thereby increasing the usable cooling temperature difference.

[0005] However, despite the significant improvement in heat dissipation at the hot end of this integrated microchannel solution, it still has inherent, unresolved flaws in its fundamental principles and structure: First, the thermal bypass effect is not completely suppressed. This solution uses traditional materials such as epoxy resin to fill the gaps in the thermoelectric arms, and the thermal conductivity of these materials (0.02-0.2 W / m·K) is still relatively high compared to the ideal insulation requirements. More importantly, the vertical solid-state heat conduction path connecting the hot and cold ends, the ceramic substrate, still exists, and heat can still leak directly from the hot end to the cold end through this path. This means that even if the heat dissipation at the hot end is enhanced, the cooling capacity loss caused by the thermal bypass effect is still significant, and the improvement of the overall thermoelectric conversion efficiency of the device faces a ceiling, making it difficult to meet the pursuit of extreme cooling temperature differences. Second, during the system-level integration of the device and the chip, the mismatch of the thermal expansion coefficients between the multilayer materials will lead to stress accumulation under thermal cycling, causing interface cracking and increased thermal resistance, seriously threatening the reliability of long-term operation.

[0006] In summary, while existing integrated microchannel thermal TEC (Thermoelectric Cooling) technology has made progress in hot-end heat dissipation, it has failed to fundamentally solve the two deep-seated problems of thermal bypass effect and thermal stress mismatch, thus limiting the full potential of thermoelectric cooling technology in high-efficiency, high-reliability cutting-edge heat dissipation fields. Therefore, there is an urgent need for a TEC solution that can simultaneously achieve ultra-strong hot-end heat dissipation, ultra-low thermal bypass leakage, and high interface reliability to overcome the current technological bottlenecks. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array, and its preparation method.

[0008] The technical problem to be solved by this invention is achieved through the following technical solution: A TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array, comprising: A first heat-conducting layer and a second heat-conducting layer; both the outer surfaces of the first heat-conducting layer and the second heat-conducting layer are provided with liquid flow microchannels; The first electrode layer is located on the inner surface of the first thermally conductive layer; The second electrode layer is located on the inner surface of the second thermally conductive layer; Multiple TEC units are located between the first electrode layer and the second electrode layer; each TEC unit includes a P-type thermoelectric arm, an N-type thermoelectric arm, and a suspended thermoelectric arm; the P-type thermoelectric arms and N-type thermoelectric arms of the multiple TEC units are arranged alternately and connected to the first electrode layer and the second electrode layer; In the TEC unit, the suspended thermoelectric arm is suspended between the P-type thermoelectric arm and the N-type thermoelectric arm, including the P-type thermoelectric arm and the N-type thermoelectric arm; wherein, the P-type thermoelectric arm and the N-type thermoelectric arm, the N-type thermoelectric arm and the P-type thermoelectric arm, and the P-type thermoelectric arm and the N-type thermoelectric arm are all connected by metal materials.

[0009] Optionally, the TEC unit further includes: a first SiO2 layer and a second SiO2 layer; The first SiO2 layer is located on the inner surface of the first thermally conductive layer; the second SiO2 layer is located on the inner surface of the second thermally conductive layer.

[0010] Optionally, in the TEC unit, the gaps on both sides of the suspended thermoelectric arm are filled with aerogel or other materials with thermal bypass inhibition properties.

[0011] Optionally, the N-type thermoelectric material of the N-type thermoelectric arm is Bi. y Sb 2-y Te3, I-doped PbTe, Br-doped PbTe, Si 80 Ge 20 One of P2, ZrNiSn / TiNiSn, and Mg3Sb2; wherein the value of y ranges from 0.2 to 0.3.

[0012] Optionally, the P-type thermoelectric material of the P-type thermoelectric arm is Bi. x Sb 2x Te3, Pb 0.98 Na 0.02 Te, Pb 0.97 Ag 0.03 Te and Si 80 Ge 20 B 0.6 One of them; where x takes values ​​from 0.4 to 0.6.

[0013] Optionally, the P-type thermoelectric material of the P-type thermoelectric arm is the same as that of the P-type thermoelectric arm; the N-type thermoelectric material of the N-type thermoelectric arm is the same as that of the N-type thermoelectric arm.

[0014] Optionally, the materials of the first thermally conductive layer and the second thermally conductive layer are one of alumina ceramic, aluminum nitride ceramic, beryllium oxide ceramic, silicon nitride ceramic, polyimide, and metal matrix composites.

[0015] Optionally, the metal-based composite material is a Cu / graphene composite layer.

[0016] Optionally, the first electrode layer, the first electrode layer and the metal material are all Cu.

[0017] This invention also provides a method for fabricating a TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array, comprising the following steps: Step 1: Prepare the first electrode layer on the first thermally conductive layer; Step 2: Prepare alternating P-type thermoelectric arms and N-type thermoelectric arms on the first electrode layer and divide them into multiple TEC units, each TEC unit containing one P-type thermoelectric arm and one N-type thermoelectric arm; Step 3: Fabricate a suspended thermoelectric arm between the P-type thermoelectric arm and the N-type thermoelectric arm of each TEC unit; wherein, the suspended thermoelectric arm is suspended between the P-type thermoelectric arm and the N-type thermoelectric arm, and includes a P-type thermoelectric arm and an N-type thermoelectric arm; the P-type thermoelectric arm and the N-type thermoelectric arm, the N-type thermoelectric arm and the P-type thermoelectric arm, and the P-type thermoelectric arm and the N-type thermoelectric arm are all connected by metal materials; Step 4: Fabricate a second electrode layer on the plurality of TEC units; Step 5: Prepare a second thermally conductive layer on the second electrode layer; Step 6: Form liquid flow microchannels on the outer surfaces of the first and second thermally conductive layers.

[0018] The TEC composite structure integrating microchannels and tandem enhanced thermoelectric arm arrays provided by this invention has the following beneficial effects: (1) Significantly improves heat dissipation capacity and cooling stability under high heat flux density: An active liquid cooling architecture is constructed by incorporating liquid flow microchannels in the thermally conductive layer. This structure can efficiently and rapidly dissipate accumulated heat through forced convection. It solves the "thermal runaway" problem caused by the limited thermal conductivity of the alumina ceramic substrate at the hot end of traditional TECs, ensuring that the hot end temperature does not rise sharply under high heat flux density (such as exceeding 50 W / cm² or even 100 W / cm²), thus maintaining an effective cooling temperature difference and expanding the application limits of TECs in high-power chips and other scenarios.

[0019] (2) Suppress the thermal bypass effect and improve thermoelectric conversion efficiency and effective cooling temperature difference: Suspended thermocouple arms are connected in series with adjacent P-type and N-type thermocouple arms via metal materials, forming an extended, suspended thermocouple pair. When the entire TEC is energized, the nodes of these suspended thermocouple arms (especially at the metal connections) also generate the Peltier effect, actively "capturing" and consuming heat leaking from the hot end to the cold end along the non-functional path. This active thermal bypass suppression mechanism, compared to passive insulation solutions that rely solely on low thermal conductivity filler materials (such as epoxy resin and aerogel), can more effectively block heat leakage paths, significantly reduce the cooling capacity offset caused by the thermal bypass effect, and thus significantly improve the overall thermoelectric conversion efficiency and the actual achievable effective cooling temperature difference.

[0020] (3) Synergy between structural integration and performance optimization: This invention innovatively integrates microchannel active heat dissipation with active thermal management via a suspended series thermoelectric arm into a compact TEC composite structure. These two technologies are not simply superimposed, but rather work synergistically: the microchannels ensure timely heat dissipation, preventing heat accumulation at the hot end and creating conditions for maintaining a large temperature difference; while the suspended thermoelectric arm structure ensures that, under conditions of temperature difference, heat loss through non-cooling paths is minimized, maximizing the use of the cooling capacity generated by the Peltier effect for the target cooling area. This integrated design enables the TEC to simultaneously possess excellent heat dissipation capabilities and high cooling efficiency when dealing with high power density heat dissipation demands.

[0021] (4) Enhanced the structural reliability and thermal cycling resistance of the device during long-term operation: Traditional multilayer heterogeneous material integration is prone to stress during thermal cycling due to mismatched coefficients of thermal expansion, leading to interface cracking. In this invention, the suspended thermoelectric arm structure reduces or optimizes certain rigid connections and filling interfaces, potentially helping to alleviate localized stress concentration. Simultaneously, microchannel heat dissipation effectively reduces the overall temperature and temperature fluctuation range during device operation, thereby mitigating thermal stress. These factors combined are expected to improve the structural integrity and performance reliability of the TEC under harsh, intermittent, or long-term continuous operating conditions, meeting the heat dissipation requirements of high-reliability electronic devices (such as communication chips and lasers).

[0022] In summary, this invention achieves comprehensive technical effects such as greater cooling temperature difference, higher energy efficiency, and more stable and reliable operation in high power density application scenarios.

[0023] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a TEC composite structure integrating a microchannel and a series-enhanced thermoelectric arm array provided by the present invention; Figure 2 This invention provides a fabrication process for a TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array; Figures 3-7 It shows Figure 2 The step-by-step process of the method shown. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0026] To achieve a TEC solution that simultaneously provides superior hot-end heat dissipation, ultra-low thermal bypass leakage, and high interface reliability, this invention provides a TEC composite structure integrating a microchannel and a series-enhanced thermoelectric arm array. (See also...) Figure 1 As shown, the TEC composite structure includes: First heat-conducting layer and second heat-conducting layer ( Figure 1 (Two thermally conductive layers, upper and lower); the outer surfaces of both the first and second thermally conductive layers are provided with liquid flow microchannels. The first electrode layer is located on the inner surface of the first thermally conductive layer; The second electrode layer is located on the inner surface of the second thermally conductive layer; Multiple TEC units are located between the first and second electrode layers. Each TEC unit includes P-type thermoelectric arms, N-type thermoelectric arms, and suspended thermoelectric arms. The P-type and N-type thermoelectric arms of the multiple TEC units are arranged alternately and connected to the first and second electrode layers. Here, the P-type thermoelectric arms are formed of P-type thermoelectric material, and the N-type thermoelectric arms are formed of N-type thermoelectric material. Figure 1 The image shows the locations of the P-type and N-type thermoelectric materials, with the P-type and N-type thermoelectric arms connected to the first and second electrode layers, respectively.

[0027] It should be noted that, Figure 1 The example shows a TEC composite structure containing two TEC units. In practice, the number of TEC units can be arbitrarily expanded, and the present invention does not limit this.

[0028] In each TEC unit, a suspended thermoelectric arm is suspended between its P-type thermoelectric arm and N-type thermoelectric arm, including a P-type thermoelectric arm and an N-type thermoelectric arm. Here, the P-type thermoelectric arm is formed of P-type thermoelectric material, and the N-type thermoelectric arm is formed of N-type thermoelectric material. Figure 1 The diagram shows the locations of the P-type and N-type thermoelectric materials. The P-type and N-type thermoelectric materials, suspended between the P-type and N-type thermoelectric arms, respectively form the P-type and N-type thermoelectric arms. Furthermore, as shown in... Figure 1 As shown, the P-type thermoelectric arm and the N-type thermoelectric arm, the N-type thermoelectric arm and the P-type thermoelectric arm, and the P-type thermoelectric arm and the N-type thermoelectric arm are all connected by metal materials.

[0029] In this invention, the liquid flow microchannels in the first and second thermally conductive layers allow refrigerant to circulate, thereby rapidly dissipating heat accumulated at the hot and cold ends and preventing thermal saturation. Simultaneously, when energized, the suspended series thermoelectric arms generate an additional Peltier heat absorption effect at the metal connection nodes, actively intercepting and consuming parasitic heat flow leaking directly from the hot to the cold end. Based on this structural design, the TEC composite structure of integrated microchannels and series-enhanced thermoelectric arm array provided by this invention has the following beneficial effects: (1) Significantly improves heat dissipation capacity and cooling stability under high heat flux density: An active liquid cooling architecture is constructed by incorporating liquid flow microchannels in the thermally conductive layer. This structure can efficiently and rapidly dissipate accumulated heat through forced convection. It solves the "thermal runaway" problem caused by the limited thermal conductivity of the alumina ceramic substrate at the hot end of traditional TECs, ensuring that the hot end temperature does not rise sharply under high heat flux density (such as exceeding 50 W / cm² or even 100 W / cm²), thus maintaining an effective cooling temperature difference and expanding the application limits of TECs in high-power chips and other scenarios.

[0030] (2) Suppress the thermal bypass effect and improve thermoelectric conversion efficiency and effective cooling temperature difference: Suspended thermocouple arms are connected in series with adjacent P-type and N-type thermocouple arms via metal materials, forming an extended, suspended thermocouple pair. When the entire TEC is energized, the nodes of these suspended thermocouple arms (especially at the metal connections) also generate the Peltier effect, actively "capturing" and consuming heat leaking from the hot end to the cold end along the non-functional path. This active thermal bypass suppression mechanism, compared to passive insulation solutions that rely solely on low thermal conductivity filler materials (such as epoxy resin and aerogel), can more effectively block heat leakage paths, significantly reduce the cooling capacity offset caused by the thermal bypass effect, and thus significantly improve the overall thermoelectric conversion efficiency and the actual achievable effective cooling temperature difference.

[0031] (3) Synergy between structural integration and performance optimization: This invention innovatively integrates microchannel active heat dissipation with active thermal management via a suspended series thermoelectric arm into a compact TEC composite structure. These two technologies are not simply superimposed, but rather work synergistically: the microchannels ensure timely heat dissipation, preventing heat accumulation at the hot end and creating conditions for maintaining a large temperature difference; while the suspended thermoelectric arm structure ensures that, under conditions of temperature difference, heat loss through non-cooling paths is minimized, maximizing the use of the cooling capacity generated by the Peltier effect for the target cooling area. This integrated design enables the TEC to simultaneously possess excellent heat dissipation capabilities and high cooling efficiency when dealing with high power density heat dissipation demands.

[0032] (4) Enhanced the structural reliability and thermal cycling resistance of the device during long-term operation: Traditional multilayer heterogeneous material integration is prone to stress during thermal cycling due to mismatched coefficients of thermal expansion, leading to interface cracking. In this invention, the suspended thermoelectric arm structure reduces or optimizes certain rigid connections and filling interfaces, potentially helping to alleviate localized stress concentration. Simultaneously, microchannel heat dissipation effectively reduces the overall temperature and temperature fluctuation range during device operation, thereby mitigating thermal stress. These factors combined are expected to improve the structural integrity and performance reliability of the TEC under harsh, intermittent, or long-term continuous operating conditions, meeting the heat dissipation requirements of high-reliability electronic devices (such as communication chips and lasers).

[0033] Optionally, in one implementation, the TEC unit may further include: a first SiO2 layer and a second SiO2 layer; the first SiO2 layer is located on the inner surface of the first thermally conductive layer; and the second SiO2 layer is located on the inner surface of the second thermally conductive layer.

[0034] Understandably, SiO2's extremely low thermal conductivity significantly increases thermal resistance at the interface, further blocking parasitic heat leakage paths from the hot end through the electrodes to the cold end. Simultaneously, as an electrical insulating layer, SiO2 prevents potential short-circuit risks between electrodes, thereby improving the overall thermal insulation performance and cooling efficiency of the structure.

[0035] Alternatively, in one implementation, the gaps on both sides of the suspended thermoelectric arm in the TEC unit are filled with aerogel or other materials with thermal bypass inhibition properties (such as epoxy resin, polymer foam).

[0036] It is understandable that materials such as aerogels have low thermal conductivity, and filling the gaps on both sides of the suspended thermoelectric arm with them can effectively improve the thermal bypass suppression effect.

[0037] Optionally, the N-type thermoelectric material of the N-type thermoelectric arm is Bi. y Sb 2-yTe3, I-doped PbTe, Br-doped PbTe, Si 80 Ge 20 One of P2, ZrNiSn / TiNiSn, and Mg3Sb2; wherein the value of y ranges from 0.2 to 0.3.

[0038] Optionally, the P-type thermoelectric material of the P-type thermoelectric arm is Bi. x Sb 2x Te3, Pb 0.98 Na 0.02 Te, Pb 0.97 Ag 0.03 Te and Si 80 Ge 20 B 0.6 One of them; where x takes values ​​from 0.4 to 0.6.

[0039] In this invention, the P-type thermoelectric material of the P-type thermoelectric arm can be the same as or different from the P-type thermoelectric material of the P-type thermoelectric arm; the N-type thermoelectric material of the N-type thermoelectric arm can be the same as or different from the N-type thermoelectric material of the N-type thermoelectric arm.

[0040] Understandably, using the same material system ensures a match in the coefficients of thermal expansion between the thermoelectric arm and the thermionic arm, reducing interfacial thermal stress and improving long-term reliability. Furthermore, sputtering or deposition processes can be completed in one step or continuously, simplifying the process and making it suitable for mass production. In contrast, dissimilar material system solutions focus on pushing performance limits, making them suitable for high-end heat dissipation scenarios that demand maximum cooling temperature difference and efficiency. However, this comes at the cost of increased process complexity, requiring careful control of the interfacial contact resistance and thermal resistance between different materials, potential reliability risks due to thermal expansion mismatch, and typically higher manufacturing costs.

[0041] In practical applications, thermoelectric coolers (TECs) are mainly divided into two categories according to application requirements: one is chip-level heat dissipation thin-film TECs, which are specifically designed for cooling local hot spots on chips. They are usually manufactured using MEMS (Micro-Electro-Mechanical Systems) or thin-film processes, and have extremely high miniaturization and integration. Under this requirement, the thermoelectric arms are micron-scale columnar structures, with typical dimensions of 0.07~0.20mm in length and 0.001~0.05mm in width. The gap between P-type and N-type thermoelectric arms is extremely small (0.003~0.3mm), aiming to accommodate a small amount of heat per unit area. With the most thermocouple pairs, extremely high power density and transient cooling response can be achieved. Another type of application requirement is engineering cooling / heating bulk TEC, which is a common semiconductor cooling chip, suitable for large temperature difference scenarios such as refrigerators and industrial temperature control. Under this requirement, the size of the thermoelectric arm is significantly increased (length 1.0~10.0mm, width 1.0~30.0mm), and the spacing between P-type and N-type thermoelectric arms is also wider (0.5~2.0mm). This type of design is designed to withstand large currents, achieve large temperature differences, and provide space for filling insulating and thermally conductive materials to prevent short circuits in the thermoelectric arm due to thermal stress or vibration, thereby ensuring the mechanical and electrical reliability of long-term operation.

[0042] In addition, the height of the thermoelectric arm is generally 1 / 5 to 2 / 3 of the height of the thermoelectric arm from the electrode layer; the thickness is 1 / 5 to 1 / 10 of the height of the thermoelectric arm.

[0043] Optionally, the materials of the first and second thermally conductive layers are one of alumina ceramics, aluminum nitride ceramics, beryllium oxide ceramics, silicon nitride ceramics, polyimide, and metal matrix composites. These materials have high thermal conductivity, which can effectively conduct the heat generated by the thermoelectric arm to the microchannel heat dissipation surface, and are compatible with microfabrication processes, making it easy to form fluid flow microchannels on or inside their surfaces.

[0044] For example, the metal matrix composite material can be a Cu / graphene composite layer, but it is not limited to this. Here, the Cu / graphene composite layer can be a graphene film deposited on the copper surface, or graphene can be distributed as a reinforcing phase in the copper matrix to form a three-dimensional network. This structure can utilize the "phonon high-speed channel" effect of graphene to significantly improve heat dissipation efficiency.

[0045] Based on the same inventive concept, this invention also provides a method for preparing the above-mentioned TEC composite structure of integrated microchannels and tandem enhanced thermoelectric arm arrays, see [link to relevant documentation]. Figures 2-7 As shown, it includes the following steps: Step 1: Prepare the first electrode layer on the first thermally conductive layer.

[0046] For details, see Figure 3 Electrode material (e.g., deposited on the first thermally conductive layer) Figure 3The image shows Cu), then photoresist is coated, and the electrode pattern is defined by exposure and development, followed by etching to form the first electrode layer.

[0047] Step 2: Prepare alternating P-type thermoelectric arms and N-type thermoelectric arms on the first electrode layer and divide them into multiple TEC units, each TEC unit containing one P-type thermoelectric arm and one N-type thermoelectric arm.

[0048] For details, see Figure 4 Based on step 1, a SiO2 layer is first deposited as an insulating or protective layer. The SiO2 deposited above the first electrode layer is removed by photoresist washing, leaving only the SiO2 on the first thermally conductive layer (the first SiO2 layer). Then, photoresist is applied to the first electrode layer, and the positions of the P-type and N-type thermoelectric arms are defined by photolithography (exposure and development). Subsequently, a periodically alternating array of P-type and N-type thermoelectric arms is formed on the first electrode layer using a sputtering deposition process, forming a basic thermoelectric arm array. Each pair of PN thermoelectric arms constitutes a TEC unit.

[0049] Step 3: Prepare a suspended thermoelectric arm between the P-type thermoelectric arm and the N-type thermoelectric arm of each TEC unit.

[0050] For details, see Figure 5 Based on step 2, firstly, a photoresist is applied, and then, using the applied photoresist as a support, a layer of metal material (such as Cu) is deposited between the P-type thermoelectric arm and the N-type thermoelectric arm of the TEC unit. Then, photoresist is applied on this metal material, and the area of ​​the suspended thermoelectric arm is defined by photolithography (exposure and development). Then, the metal material in this area is etched away. Subsequently, the corresponding P-type and N-type thermoelectric materials are sputtered to deposit in the area exposed after etching to form the P-type thermoelectric arm and the N-type thermoelectric arm. The remaining metal material connects the P-type thermoelectric arm with the N-type thermoelectric arm, the N-type thermoelectric arm with the P-type thermoelectric arm, and the P-type thermoelectric arm with the N-type thermoelectric arm, thereby forming a suspended thermoelectric arm between the P-type thermoelectric arm and the N-type thermoelectric arm.

[0051] Step 4: Fabricate a second electrode layer on multiple TEC units.

[0052] For details, see Figure 6 Building upon step 3, a layer of SiO2 is first deposited. Then, by removing the photoresist, the SiO2 between adjacent TED units and the SiO2 above the suspended thermoelectric arms in each TEC unit (the second SiO2 layer) are retained, resulting in a smooth sample surface. Next, a second electrode layer material (such as Cu) is deposited across the entire surface. Then, photoresist is applied, the pattern defining the region between adjacent TED units is photolithographically etched, and etching is performed to form the second electrode layer that electrically connects the various TEC units.

[0053] Step 5: Prepare a second thermally conductive layer on the second electrode layer.

[0054] For details, see Figure 7 Photoresist is applied to the prepared second electrode layer, the photoresist in the middle region is exposed and fixed, and after removing the photoresist on both sides, the second thermally conductive layer is deposited directly on the surface of the current structure.

[0055] Step 6: Form liquid flow microchannels on the outer surfaces of the first and second thermally conductive layers.

[0056] Specifically, a resist is applied to the outer surfaces of the first and second thermally conductive layers (i.e., the surfaces opposite to the thermoelectric arm array). Microchannel regions are defined using photolithography (exposure and development), and then liquid flow microchannels are formed within the thermally conductive layers through etching. Figure 7 This is the final step, thus completing the preparation of the entire composite TEC structure.

[0057] Alternatively, in one implementation, if step 3 (see...) Figure 5 If the first step in the process involves applying photoresist, then after depositing SiO2 in step 4, the photoresist can be removed. In another implementation, if step 3 (see...) Figure 5 If the first step in step 3 involves applying an aerogel or other material with thermal bypass suppression, then before depositing SiO2 in step 4, the same adhesive as in the first step of step 3 can be applied to the sample surface first, followed by SiO2 deposition. This allows the aerogel or other material with thermal bypass suppression to be retained in the gaps on both sides of the suspended thermoelectric arm, thereby improving the thermal bypass suppression effect of the final prepared TEC structure.

[0058] Alternatively, in one implementation, after the second electrode layer is formed in step 4, SiO2 can be removed by acid leaching. As a result, the final TEC composite structure will not contain the first SiO2 layer and the second SiO2 layer. This increases the space between the hot spot arms, enhances heat dissipation, and is suitable for situations where the TEC integration is not very high.

[0059] In addition, regarding the materials and dimensional parameters of the structures prepared in the preparation method embodiments, please refer to the above structural embodiments, which will not be repeated here.

[0060] It should be noted that the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0062] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings and the disclosure in carrying out the claimed invention. In the description of the invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality, and "a plurality" means two or more, unless otherwise explicitly specified. Furthermore, while different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce good results.

[0063] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0064] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0065] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array, characterized in that, include: A first heat-conducting layer and a second heat-conducting layer; both the outer surfaces of the first heat-conducting layer and the second heat-conducting layer are provided with liquid flow microchannels; The first electrode layer is located on the inner surface of the first thermally conductive layer; The second electrode layer is located on the inner surface of the second thermally conductive layer; Multiple TEC units are located between the first electrode layer and the second electrode layer; each TEC unit includes a P-type thermoelectric arm, an N-type thermoelectric arm, and a suspended thermoelectric arm; the P-type thermoelectric arms and N-type thermoelectric arms of the multiple TEC units are arranged alternately and connected to the first electrode layer and the second electrode layer; In the TEC unit, the suspended thermoelectric arm is suspended between the P-type thermoelectric arm and the N-type thermoelectric arm, including the P-type thermoelectric arm and the N-type thermoelectric arm; wherein, the P-type thermoelectric arm and the N-type thermoelectric arm, the N-type thermoelectric arm and the P-type thermoelectric arm, and the P-type thermoelectric arm and the N-type thermoelectric arm are all connected by metal materials.

2. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 1, characterized in that, The TEC unit further includes: a first SiO2 layer and a second SiO2 layer; The first SiO2 layer is located on the inner surface of the first thermally conductive layer; the second SiO2 layer is located on the inner surface of the second thermally conductive layer.

3. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 1, characterized in that, In the TEC unit, the gaps on both sides of the suspended thermoelectric arm are filled with aerogel or other materials with thermal bypass inhibition properties.

4. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 1, characterized in that, The N-type thermoelectric material of the N-type thermoelectric arm is Bi. y Sb 2-y Te3, I-doped PbTe, Br-doped PbTe, Si 80 Ge 20 One of P2, ZrNiSn / TiNiSn, and Mg3Sb2; wherein the value of y ranges from 0.2 to 0.

3.

5. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 1, characterized in that, The P-type thermoelectric material of the P-type thermoelectric arm is Bi. x Sb 2x Te3, Pb 0.98 Na 0.02 Te, Pb 0.97 Ag 0.03 Te and Si 80 Ge 20 B 0.6 One of them; where x takes values ​​from 0.4 to 0.

6.

6. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 4 or 5, characterized in that, The P-type thermoelectric material of the P-type thermoelectric arm is the same as that of the P-type thermoelectric arm; the N-type thermoelectric material of the N-type thermoelectric arm is the same as that of the N-type thermoelectric arm.

7. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 1, characterized in that, The materials of the first thermal conductive layer and the second thermal conductive layer are one of alumina ceramic, aluminum nitride ceramic, beryllium oxide ceramic, silicon nitride ceramic, polyimide and metal matrix composite materials.

8. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 7, characterized in that, The metal-based composite material is a Cu / graphene composite layer.

9. The TEC composite structure of integrated microchannel and tandem enhanced thermoelectric arm array according to claim 1, characterized in that, The first electrode layer, the first electrode layer and the metal material are all Cu.

10. A method for fabricating a TEC composite structure integrating microchannels and a series-enhanced thermoelectric arm array, characterized in that, Includes the following steps: Step 1: Prepare the first electrode layer on the first thermally conductive layer; Step 2: Prepare alternating P-type thermoelectric arms and N-type thermoelectric arms on the first electrode layer and divide them into multiple TEC units, each TEC unit containing one P-type thermoelectric arm and one N-type thermoelectric arm; Step 3: Fabricate a suspended thermoelectric arm between the P-type thermoelectric arm and the N-type thermoelectric arm of each TEC unit; wherein, the suspended thermoelectric arm is suspended between the P-type thermoelectric arm and the N-type thermoelectric arm, and includes a P-type thermoelectric arm and an N-type thermoelectric arm; the P-type thermoelectric arm and the N-type thermoelectric arm, the N-type thermoelectric arm and the P-type thermoelectric arm, and the P-type thermoelectric arm and the N-type thermoelectric arm are all connected by metal materials; Step 4: Fabricate a second electrode layer on the plurality of TEC units; Step 5: Prepare a second thermally conductive layer on the second electrode layer; Step 6: Form liquid flow microchannels on the outer surfaces of the first and second thermally conductive layers.

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