Composite enhanced thermoelectric module based on Tesla valve structure and manufacturing method

Abstract

The invention discloses a composite enhanced thermoelectric module based on a Tesla valve structure and a manufacturing method thereof. The module comprises a fan, a heat dissipation module, a thermoelectric module and a control unit. The heat dissipation module is characterized in that the heat dissipation module is formed by superposing a plurality of ultrathin metal fins, the surfaces of the ultrathin metal fins are provided with flow guide concave bags and flow collecting cavities, the flow guide concave bags and the flow collecting cavities jointly form a bionic Tesla valve airflow channel, and efficient and low-resistance heat dissipation is achieved; the surface of the metal fin is provided with a rigidity enhancing and radiation enhancing coating; the hot end of the thermoelectric module is in eutectic combination with the heat dissipation module through a micro-anchoring interlocking structure, so that the interface thermal resistance is remarkably reduced; the temperature of the refrigeration surface of the thermoelectric module is independently controlled in a partitioned mode, the control unit cooperatively regulates and controls the power of all the areas with the lowest temperature in all the areas as the reference, and it is ensured that the surface temperature is highly uniform. According to the invention, the heat dissipation performance, the connection reliability and the temperature control precision of the module are systematically improved, and the module is suitable for the high-requirement precise temperature control field.

Description

Technical Field

[0001] This invention relates to the field of thermoelectric refrigeration technology, specifically to a composite enhanced thermoelectric module based on a Tesla valve structure and its manufacturing method, which is applicable to high-precision temperature control fields such as medical constant temperature equipment, lasers, and battery packs. Background Technology

[0002] The performance limit of a thermoelectric cooling (TEC) module is determined by its hot-end heat dissipation efficiency. In existing technologies, heat dissipation modules are mostly made of aluminum profiles, die-casting, or using a toothed process, and their airflow channels are mostly straight-channel structures, which have the following inherent drawbacks:

[0003] 1. Low heat dissipation efficiency: The airflow disturbance within the straight channel is weak, the thermal boundary layer is thick, and the heat exchange efficiency is limited. Increasing the fin density or volume to improve heat dissipation capacity will lead to a sharp increase in wind resistance and module weight, making it difficult to meet the requirements of equipment compactness and lightweighting.

[0004] 2. Poor airflow directionality: The channel lacks unidirectional airflow characteristics, which easily leads to backflow and heat accumulation, further reducing heat dissipation efficiency;

[0005] 3. Insufficient temperature uniformity: Uneven heat dissipation can easily lead to local hot spots on the cold end of the thermoelectric module. Traditional centralized temperature control cannot make targeted adjustments, and the temperature deviation of the cold end is usually more than 5°C, which affects the performance and lifespan of the cooled equipment.

[0006] Tesla valves, as a unidirectional fluid guiding structure without moving parts, have been applied in fields such as microfluidics due to their characteristics of "low flow resistance in the forward direction and high flow resistance in the reverse direction". However, existing technologies have not innovatively applied them to the heat dissipation airflow channel design of thermoelectric modules to systematically solve the aforementioned bottleneck problems. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provide a composite enhanced thermoelectric module with high heat dissipation efficiency, orderly airflow organization, low interface thermal resistance and precise temperature control, as well as its manufacturing method.

[0008] The specific technical solution is as follows:

[0009] A composite enhanced thermoelectric module based on a Tesla valve structure includes a fan and a heat dissipation module, with the thermoelectric module located at the bottom of the heat dissipation module;

[0010] A heat dissipation module, which is composed of multiple ultra-thin metal fins stacked together;

[0011] The hot end of the thermoelectric module is connected to the bottom of the heat dissipation module through an interface eutectic layer;

[0012] The surface of the metal fin is provided with a composite reinforcement structure, which includes:

[0013] a. A rigidity-enhancing and radiation-enhancing coating formed on the surface of the metal fins;

[0014] b. Multiple sets of positively aligned flow-guiding recesses formed by stamping on the surface of the metal fins;

[0015] c. A flow collection cavity formed between adjacent flow guide recesses;

[0016] In this design, adjacent metal fins are stacked, and the guide concave and the collection cavity are alternately arranged in the gaps between the stacked fins, together forming a continuous flow channel with an asymmetrical cross-section. When airflow passes through, under the action of the fan, the airflow is buffered in the collection cavity and evenly distributed to the guide concave and accelerated, resulting in smooth flow. When the airflow attempts to flow in the opposite direction, it will generate violent eddies and collisions in the collection cavity, forming significantly higher flow resistance, thereby achieving unidirectional airflow and greatly enhancing the heat transfer effect.

[0017] Furthermore, the composite enhanced thermoelectric module based on the Tesla valve structure also includes a control unit. The control unit collects temperature data from all temperature sensing units set on the thermoelectric module in parallel, uses the minimum value among all temperature readings as the global temperature reference benchmark, and dynamically adjusts the electric power of each temperature control zone in the thermoelectric module according to the deviation of each temperature data from the benchmark.

[0018] Based on the above technical solution, a further design is as follows: the thickness of the metal fins is configured such that, under the synergistic effect of the surface composite reinforcement structure, the fin arrangement density of the heat dissipation module reaches more than 30 fins per inch. Preferably, the thickness of the metal fins is no greater than 0.2 mm. If the fin density is too low, the rectification effect and boundary layer disruption effect of the Tesla valve (low forward flow resistance and high reverse flow resistance) will be greatly reduced, and its performance will degenerate into that of ordinary turbulence fins.

[0019] Based on the above technical solution, a further design is as follows: the rigidity-enhancing and radiation-enhancing coating is a diamond-like carbon coating with a thickness of 1~5μm and an overall emissivity greater than 0.90, of which the infrared emissivity is not less than 0.92. The high thermal emissivity of this coating significantly improves the radiative heat dissipation capacity of the fin surface.

[0020] The enhanced coating, through its high hardness and strong bond with the substrate, provides additional structural support for the ultrathin fins, significantly improving the fins' bending stiffness and assembly yield, making it possible to achieve high-density arrangement of ultrathin fins.

[0021] A fin thickness of 0.2mm is a recognized technical threshold in the industry. At this thickness, the mechanical strength is inherently very fragile, making it highly susceptible to bending, deformation, or collapse. This patent, however, uses a stamping process to manufacture fins with a thickness of up to 0.1mm, offering high production efficiency, low cost, flexible design, and high consistency. More importantly, this patented method forms a diamond-like carbon coating on the fin surface and, through stamping, creates raised flow-guiding recesses and flow-collecting cavities, significantly enhancing the fin's strength and effectively combining ultra-thinness with high strength. This also facilitates increased fin density, thereby greatly increasing the heat exchange area.

[0022] According to the above technical solution, the further design is as follows: the bottom of the metal fin is provided with a bent base plate, the bent base plate area is nickel plated and provided with multiple micro anchoring holes;

[0023] The corresponding plane of the thermoelectric module is provided with an anchoring groove that matches the position of the micro-anchoring hole;

[0024] Metal solder fills the micro-anchoring holes and anchoring grooves to form a wedge-type mechanical interlock.

[0025] Based on the above technical solution, a further design is as follows: the cross-sectional shape of the anchoring groove is trapezoidal or arc-shaped. The trapezoidal design provides excellent resistance to shear stress; the arc-shaped design effectively avoids stress concentration at sharp corners, improving the fatigue life of the connection structure.

[0026] According to the above technical solution, a further design is as follows: by preparing multiple rows of mutually isolated electrical lines on the carrier plate of the thermoelectric module, a temperature control area that is electrically isolated from each other is set in the thermoelectric module;

[0027] The spacing between each row of electrical circuits is less than 5mm, and a temperature sensor is installed next to each row of electrical circuits.

[0028] According to the above technical solution, the further design is as follows: the heat dissipation module is provided with an air jet inlet and an air intake inlet that are connected to the airflow channel of the Tesla valve; and the edge of the guide concave bulge on the air outlet side is torn, forming a fluid oscillation area.

[0029] A method for manufacturing a composite enhanced thermoelectric module includes the following steps:

[0030] S1. Preparation of reinforced fins: The metal sheet is stamped to form a flow guiding concave, flow collecting cavity and process hole, and then a rigidity-enhancing and radiation-enhancing coating is deposited on the surface of the stamped fin.

[0031] S2. Assemble the heat dissipation module: Align and stack multiple composite reinforced fins prepared in step S1 through the process holes, and insert and lock them in place with fasteners, so that the flow guide recess and the flow collection cavity form a complete Tesla valve airflow channel. Ensuring uniform fin spacing through process holes and tooling is an important means to achieve a high-density, high-performance Tesla valve heat dissipation module;

[0032] S3. Install the fan assembly: Fix the fan to the fan bracket, and fix the fan bracket to the top of the heat dissipation module through a eutectic process;

[0033] S4. Fabrication of thermoelectric module: A highly insulating coating is prepared on the surface of the substrate, and multiple rows of mutually isolated electrical circuits are prepared on the insulating coating. P-type thermoelectric cells and N-type thermoelectric cells are eutectic connected on each row of electrical circuits, and temperature sensors are set next to each circuit.

[0034] S5. Eutectic Bonding: Through reflow soldering, metal solder fills the micro-anchoring holes at the bottom of the heat dissipation module and the anchoring grooves on the thermoelectric module carrier plate, forming a eutectic layer that combines metallurgical bonding and mechanical interlocking.

[0035] Beneficial effects:

[0036] 1. Excellent heat dissipation performance:

[0037] Bionic Tesla valve channel: Through the asymmetric channel formed by the flow guide concave and the flow collection cavity, the airflow is guided unidirectionally and periodically accelerated, which strongly destroys the thermal boundary layer. While reducing wind resistance by 25%-40%, the equivalent heat dissipation area is doubled.

[0038] Composite reinforced ultrathin fins: The DLC coating not only improves the radiative heat dissipation efficiency to over 0.92, but its high hardness also provides structural support for the ultrathin fins (up to 0.1mm), increasing the fin density to over 30 fins / inch. Under the same volume, the heat exchange area is increased by 40%-60% compared to traditional radiators.

[0039] Secondary airflow ejection: The unique air jet inlet and entrainment inlet design utilize the main airflow to induce additional air to participate in heat dissipation, improving the overall airflow utilization rate by more than 30%.

[0040] 2. Stable and reliable interface connection:

[0041] Micro-anchoring interlocking interface: Through the mechanical interlocking of micro-anchoring holes and anchoring grooves combined with eutectic welding, the interface thermal resistance is reduced by an order of magnitude compared with traditional TIM materials, and the shear strength of the connection surface is increased by more than 3 times. It completely eliminates the risk of interface separation caused by vibration and thermal fatigue. After 1000 cycles of hot and cold cycling, the thermal resistance change rate is <3%.

[0042] 3. Precise temperature control capability:

[0043] The zoned collaborative temperature control algorithm uses a dynamic power allocation strategy with the lowest temperature as the global benchmark, combined with a dense sensor network with a spacing of less than 5mm, to achieve ultra-high temperature uniformity on the cold end face, with a temperature difference of ≤±0.3℃, and completely eliminates local hot spots.

[0044] Extended system lifespan: Precise temperature control avoids overload and thermal stress impact on thermoelectric chips. Combined with a stable interface and efficient heat dissipation, the overall lifespan of the module is extended by 2-3 times compared to traditional products.

[0045] This invention systematically solves the heat dissipation and temperature control problems of high power density thermoelectric modules through four-dimensional collaborative innovation in structure, materials, process, and control, providing an ideal solution for the next generation of high-precision temperature control systems. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the overall structure of a composite enhanced thermoelectric module based on a Tesla valve structure;

[0047] Figure 2 yes Figure 1 A magnified view of part A in the middle;

[0048] Figure 3 This is a schematic diagram of the front structure of the heat dissipation module;

[0049] Figure 4 This is a schematic diagram of the heat dissipation airflow of the heat dissipation module;

[0050] Figure 5 This is a schematic diagram of the structure of a single metal fin;

[0051] Figure 6 This is a schematic diagram of the dorsal structure of a single metal fin;

[0052] Figure 7 This is a schematic diagram of the installation structure when the thermoelectric module forms the interface eutectic layer;

[0053] Figure 8 This is a magnified view of a local structure of the interface eutectic layer;

[0054] In the figure: 1. Fan, 2. Heat dissipation module, 21. Process hole, 22. Combustion chamber, 23. Guide recess, 24. Air outlet, 25. Air jet inlet, 26. Air entrainment inlet, 3. Fan bracket, 4. Thermoelectric module, 41. Anchoring groove, 5. Interface eutectic layer. Detailed Implementation

[0055] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0056] Example 1: As Figure 1-8 As shown, a composite enhanced thermoelectric module based on a Tesla valve structure includes a fan 1 and a heat dissipation module 2, with a thermoelectric module 4 located at the bottom of the heat dissipation module 2;

[0057] The heat dissipation module 2 is composed of multiple stacked metal fins. The metal fins are provided with a flow guide recess 23, a flow collection cavity 22, an air jet inlet 25, an air entrainment inlet 26, and a process hole 21. After the multiple metal fins are stacked, an airflow channel with a Tesla valve structure is formed. An air outlet 24 is provided at the end of the airflow channel.

[0058] The hot end of the thermoelectric module 4 is connected to the heat dissipation module 2 through the interface eutectic layer 5. The control unit collects temperature data from all temperature sensing units in parallel, uses the minimum value among all temperature readings as the global temperature reference benchmark, and dynamically adjusts the electrical power of each temperature control zone in the thermoelectric module 4 according to the deviation of each temperature data from the benchmark.

[0059] The fan bracket 3 is fixed above the heat dissipation module 2. The fan 1 is installed directly above the heat dissipation module 2 through the fan bracket 3, and the distance between the bottom of the fan 1 impeller and the top of the metal fins of the heat dissipation module 2 is not less than 0.5 times the height of the fan 1 hub.

[0060] Installation method:

[0061] 1. Preparation of heat dissipation module 2:

[0062] S1. 1050 aluminum strip with a thickness of 0.1mm is selected as the base material. It can be understood that other suitable ultra-thin metal strips can also be used.

[0063] S2. A DLC coating with a thickness of about 2 μm was deposited on both sides of the aluminum strip using plasma-enhanced chemical vapor deposition (PECVD). The surface of the coating exhibits a honeycomb and mountain-shaped microstructure, and the measured emissivity is >0.92.

[0064] S3. Using a high-precision continuous die, the aluminum strip coated with DLC is stamped to form a wing-shaped guide concave 23, a collection cavity 22, an air jet inlet 25, an air intake 26, an air outlet 24, a bent base plate, micro anchoring holes and process holes 21 in one step.

[0065] S4. Selectively mask electroplating the bent base plate area to form a nickel plating layer with a thickness of about 5μm.

[0066] S5. Align approximately 150 stamped single-piece fins (FIN) through process holes 21, insert two stainless steel straight tubes with outer diameters matching process holes 21, screw nuts into both ends of the steel tubes and tighten them to the specified torque to form a robust heat dissipation module 2.

[0067] 2. Preparation of thermoelectric module 4

[0068] S1. A metal substrate is used as the carrier substrate.

[0069] S2. An anchoring groove with a trapezoidal cross section is etched into a plane of the carrier plate, and the plane is then plated with nickel.

[0070] S3. An insulating glaze is screen-printed on another plane of the carrier board and sintered to form an insulating layer. Subsequently, multiple rows of silver-palladium electrical circuits are laid using a thick-film printing process. The circuit design ensures that the spacing between adjacent circuits is 3mm.

[0071] S4. Using eutectic bonding pads, Bi2Te3-based P / N type thermoelectric cells of predetermined dimensions are soldered to the electrical circuit. In a preferred embodiment, the thermoelectric cell dimensions are, for example, 1.4mm x 1.4mm x 1.5mm.

[0072] S5. Mount an NTC temperature sensor, for example, in a 0402 package, next to each circuit.

[0073] 3. Interface Connection and Final Assembly

[0074] S1. On the nickel-plated hot end face of the thermoelectric module 4, a layer of Sn96.5Ag3Cu0.5 lead-free solder paste is printed by stencil for subsequent formation of the interface eutectic layer 5.

[0075] S2. Align the bent base plate of the heat dissipation module 2 with the nickel-plated hot end surface of the thermoelectric module 4, so that the micro anchoring holes of the heat dissipation module 2 are precisely aligned with the anchoring grooves of the thermoelectric module 4.

[0076] S3. The assembled components are sent to a reflow oven and soldered according to the preset temperature profile (peak temperature 245℃). After the solder paste melts, it fully wets the nickel-plated surface and fills the micro-anchor holes and anchor grooves. After cooling, a strong metallurgical bond and mechanical interlocking structure are formed, namely the interface eutectic layer 5.

[0077] S4. Finally, using the fan bracket 3 made of aluminum alloy, fix an axial fan 1 with a rated voltage of 12V directly above the heat dissipation module 2, ensuring that the distance between the bottom of the fan 1 impeller and the top of the fins (FIN) of the heat dissipation module 2 is 0.6 times the height of the fan 1 hub (HUB).

[0078] S5. Connect the leads of each circuit on thermoelectric module 4 and the temperature sensor signal lines to the control board to complete the overall assembly.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A composite enhanced thermoelectric module based on a Tesla valve structure, comprising a fan (1), a heat dissipation module (2), and a thermoelectric module (4), characterized in that: The heat dissipation module (2) is composed of multiple ultra-thin metal fins stacked together; The hot end of the thermoelectric module (4) is connected to the bottom of the heat dissipation module (2) through an interface eutectic layer (5); The surface of the metal fin is provided with a composite reinforcement structure, which includes: a. A rigidity-enhancing and radiation-enhancing coating formed on the surface of the metal fins; b. Multiple sets of positively aligned flow-guiding recesses (23) formed by stamping on the surface of the metal fins. c. A flow collection cavity (22) formed between adjacent flow guide recesses (23); When adjacent metal fins are stacked, the flow guide recess (23) and the flow collection cavity (22) together form a positive airflow channel with Tesla valve characteristics.

2. The composite enhanced thermoelectric module based on a Tesla valve structure according to claim 1, characterized in that, It also includes a control unit, which collects temperature data from all temperature sensing units set on the thermoelectric module (4) in parallel, uses the minimum value among all temperature readings as the global temperature reference benchmark, and dynamically adjusts the electric power of each temperature control zone in the thermoelectric module (4) according to the deviation of each temperature data from the benchmark.

3. The composite enhanced thermoelectric module based on a Tesla valve structure according to claim 1, characterized in that, The thickness of the metal fins works in conjunction with the surface composite reinforcement structure to achieve a fin arrangement density of more than 30 fins per inch in the heat dissipation module (2).

4. The composite enhanced thermoelectric module according to claim 3, characterized in that, The thickness of the metal fins is no greater than 0.2 mm.

5. A composite enhanced thermoelectric module based on a Tesla valve structure according to claim 1, characterized in that, The rigidity-enhancing and radiation-enhancing coating is a diamond-like carbon coating with a thickness of 1~5μm and an integrated emissivity of greater than 0.90 across the entire wavelength range, of which the infrared emissivity is not less than 0.

92.

6. A composite enhanced thermoelectric module based on a Tesla valve structure according to claim 1, characterized in that, The bottom of the metal fin is provided with a bent base plate, the bent base plate area is nickel-plated and has multiple micro anchoring holes; The corresponding plane of the thermoelectric module is provided with an anchoring groove (41) that matches the position of the micro-anchoring hole. Metal solder fills the micro-anchoring holes and anchoring grooves to form a wedge-type mechanical interlock.

7. A composite enhanced thermoelectric module based on a Tesla valve structure according to claim 6, characterized in that, The cross-sectional shape of the anchoring groove is trapezoidal or circular arc.

8. A composite enhanced thermoelectric module based on a Tesla valve structure according to claim 2, characterized in that, The thermoelectric module (4) is divided into multiple independent temperature control zones by multiple electrically isolated electrical circuits fabricated on its carrier plate; wherein the spacing between each electrical circuit is less than 5 mm, and a temperature sensor is provided next to each electrical circuit.

9. A composite enhanced thermoelectric module based on a Tesla valve structure according to claim 1, characterized in that, The heat dissipation module (2) is provided with an air jet inlet (25) and an air intake inlet (26) that are connected to the airflow channel of the Tesla valve; and the edge of the guide concave on the air outlet side is torn, forming a fluid oscillation area.

10. A method for manufacturing a composite enhanced thermoelectric module as described in any one of claims 1-9, characterized in that, Including the following steps: S1. Preparation of reinforced fins: The metal sheet is stamped to form a flow guiding concave sac (23), a flow collecting cavity (22) and a process hole (21). Then, a rigidity-enhancing and radiation-enhancing coating is deposited on the surface of the stamped fin. S2. Assemble the heat dissipation module: Align and stack multiple composite reinforced fins prepared in step S1 through the process hole (21), and insert a fixing piece to lock them in place, so that the flow guide recess (23) and the flow collection cavity (22) form a complete Tesla valve airflow channel. S3. Install the fan assembly: Fix the fan (1) to the fan bracket (3) and fix the fan bracket (3) to the top of the heat dissipation module (2) through the eutectic process; S4. Fabrication of thermoelectric module: A highly insulating coating is prepared on the surface of the substrate, and multiple rows of mutually isolated electrical circuits are prepared on the insulating coating. P-type thermoelectric cells and N-type thermoelectric cells are eutectic connected on each row of electrical circuits, and temperature sensors are set next to each circuit. S5. Eutectic bonding: Through reflow soldering process, metal solder fills the micro-anchoring holes at the bottom of the heat dissipation module (2) and the anchoring grooves on the thermoelectric module carrier plate to form a eutectic layer (5) that has both metallurgical bonding and mechanical interlocking interface.

Images