Heat pipe, radiator and electronic equipment

Abstract

The invention discloses a heat pipe, a radiator and electronic equipment. The heat pipe comprises a pipe body, a first capillary structure and a second capillary structure. A containing cavity is formed in the pipe body and used for sealing and storing working fluid. The first capillary structure is attached to the inner pipe face of the pipe body. The second capillary structure is wrapped in the first capillary structure. According to the heat pipe, the first capillary structure with large capillary pressure wraps the second capillary structure with large permeability, so that the composite capillary structure with the high-speed backflow channel is formed in the heat pipe, and the advantages of different capillary structures are fully utilized; and the working fluid in the heat pipe quickly and fully participates in circulating heat transfer of liquid phase-gas phase change, so that the heat transfer performance of the heat pipe is improved.

Description

Heat pipes, radiators and electronic equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on September 12, 2023, with application number 202311171404.2 and application name “Heat Pipe, Radiator and Electronic Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of heat pipes, and more particularly, to a heat pipe, a radiator, and an electronic device. Background Art

[0003] As electronic devices are increasingly moving towards miniaturization, lightness, and high performance, the integration of electronic components in electronic devices is becoming increasingly higher, accompanied by increasing power consumption. How to quickly and effectively dissipate the heat generated by electronic components is a key issue that must be solved in the development of electronic devices towards miniaturization, lightness, and high performance.

[0004] A heat pipe is a heat transfer component that uses liquid-to-gas phase transitions to rapidly transfer heat. It is widely used in cooling high-power electronic components. Heat pipes have a capillary structure within them that circulates heat. The capillary properties of this structure determine the heat transfer performance of the heat pipe; the better the capillary properties, the greater the heat transfer capability.

[0005] When evaluating the capillary performance of a capillary structure, capillary pressure and permeability are the two most important parameters. How to balance the relationship between capillary pressure and permeability so that the capillary structure can achieve a high permeability while having a large capillary pressure to reduce the resistance to liquid reflux is the key to improving the heat transfer performance of heat pipes.

[0006] Summary of the Invention

[0007] The purpose of the present application is to provide a heat pipe, a radiator and an electronic device, which, by wrapping a first capillary structure with a large capillary pressure with a second capillary structure with a large permeability, fully utilizes the large driving force generated by the first capillary structure and the low-resistance reflux channel established by the second capillary structure, so that the working fluid in the heat pipe can quickly and fully participate in the cyclic heat transfer work of the liquid-gas phase change, thereby improving the heat transfer performance of the heat pipe.

[0008] In a first aspect, the present application provides a heat pipe comprising a pipe body, a first capillary structure, and a second capillary structure.

[0009] The interior of the tube body is provided with an accommodating cavity, and the accommodating cavity is used to seal the working fluid.

[0010] The first capillary structure is attached to the inner surface of the tube body, and the second capillary structure is wrapped inside the first capillary structure.

[0011] By selecting appropriate materials, the capillary pressure and permeability of the first capillary structure and the second capillary structure form a set relationship: the capillary pressure of the first capillary structure is greater than the capillary pressure of the second capillary structure, and the permeability of the second capillary structure is greater than the permeability of the first capillary structure.

[0012] In the heat pipe provided by the present application, the first capillary structure is made of a material with a larger capillary pressure, and the second capillary structure is made of a material with a larger permeability. Since the second capillary structure is wrapped inside the first capillary structure and is not exposed in the accommodating cavity, the inner surface of the accommodating cavity is the first capillary structure. Since the capillary pressure is a surface parameter, the capillary pressure in the heat pipe comes from the first capillary structure. Based on this case, driven by the larger capillary pressure of the first capillary structure, the liquid working fluid will flow back through the two channels of the first capillary structure and the second capillary structure at the same time, wherein the second capillary structure with low reflux resistance serves as a "high-speed channel" for the reflux of the liquid working fluid, which can quickly transfer the liquid working fluid to the evaporation part. Compared with the heat pipe with only the first capillary structure set alone, the heat pipe in the present application has a smaller reflux resistance, and compared with the heat pipe with only the second capillary structure set alone, the heat pipe in the present application has a greater driving force. Therefore, the design method of wrapping the second capillary structure with the first capillary structure makes the heat pipe in this application conducive to the reflux of the liquid working fluid, accelerates the liquid-gas phase circulation speed, and thus can improve the heat transfer capacity of the heat pipe, which can effectively prevent dry burning in the evaporation part and liquid accumulation in the condensation part, making it less likely for the heat pipe to reach the heat transfer limit.

[0013] In addition, since the liquid-phase working fluid can flow back to the evaporation part along the second capillary structure, it will not conflict with the gas-phase working fluid in the accommodating cavity, thereby isolating the gas-phase working fluid from the liquid-phase working fluid, so that the gas-phase working fluid will not be obstructed by the counter-flow of the returning liquid-phase working fluid, thereby making the liquid-gas phase change cycle in the heat pipe smoother.

[0014] In addition, since the liquid working fluid in the condensation section can be quickly transferred back to the evaporation section, the accumulation of liquid in the condensation section can be avoided, thereby effectively avoiding the problem of abnormal noise and improving the user experience. The specific reason is that the heat pipes in the related art have defects in their capillary structure design, which makes it difficult for the liquid working fluid to flow back, and it is easy for a large amount of liquid to accumulate in the condensation section. When the heat pipe or electronic device is turned over, the large amount of liquid accumulated in the condensation section will hit the inner wall of the heat pipe, making a dripping sound, which in turn affects the user experience.

[0015] In one possible design, the first capillary structure is composed of at least one of a sintered metal powder, a sintered non-metallic powder, and a metal woven mesh. These materials, most of which have very small pores, exert a high overall capillary pressure, providing a greater driving force for gas-liquid circulation within the heat pipe.

[0016] In one possible design, the second capillary structure is composed of at least one of a metal foam, a non-metallic fiber, a metal braid, or a metal braid. These materials typically have large pores and high overall permeability, thereby reducing the flow resistance of the liquid working fluid during circulation.

[0017] In one possible design, the heat pipe further includes a grooved capillary structure provided on the inner tube surface and / or the second capillary structure. The added grooved capillary structure can further improve the permeability of the entire heat pipe interior, thereby further reducing the backflow resistance of the liquid working fluid.

[0018] In one possible design, the side of the second capillary structure facing the inner tube surface is exposed from the first capillary structure and abuts against the inner tube surface. This provides a support surface on one side of the second capillary structure, thereby facilitating positioning of the second capillary structure and facilitating implementation and manufacturing.

[0019] In one possible design, the number of the second capillary structures is multiple, and the multiple second capillary structures are spaced apart along the circumference of the pipe body. The multiple spaced apart second capillary structures can further increase the reflux velocity of the liquid working fluid and enhance the heat transfer capacity of the heat pipe.

[0020] In one possible design, the first capillary structure has a raised portion at the portion corresponding to the second capillary structure. This raised portion ensures that the portion of the first capillary structure corresponding to the second capillary structure has sufficient thickness, thereby providing the first capillary structure with sufficient wrapping and fixing strength to the second capillary structure, and preventing the second capillary structure from being easily detached due to being too thin at this portion. This improves the shock resistance of the heat pipe and ensures the structural stability of the first and second capillary structures even during severe vibration, thereby improving the reliability of the heat pipe.

[0021] In one possible design, the edge of the raised portion smoothly transitions into the surface of the first capillary structure. This prevents the raised portion from having sharp corners that interfere with airflow. When the gaseous working fluid in the evaporation section flows toward the condensation section, the raised portion in this embodiment can reduce the obstruction to the gaseous working fluid, allowing the gaseous working fluid to flow quickly toward the condensation section. This in turn accelerates the liquid-to-gas circulation rate, improves the heat transfer capacity of the heat pipe, and ensures good temperature uniformity at both the hot and cold ends of the heat pipe, making it less likely to reach its heat transfer limit.

[0022] In one possible design, the tube body includes two opposing flat tube walls and two opposing curved tube walls. The flat heat pipe can be applied to electronic devices with thickness restrictions, allowing the heat pipe to meet the design requirements of lightness and thinness.

[0023] In one possible design, the first and second capillary structures are disposed on either of the two flat tube walls. When the heat pipe is flat, only the flat tube wall facing the heat transfer plate is in contact with the electronic components for heat exchange. Therefore, the first and second capillary structures can be disposed only on this flat tube wall, thereby reducing the material cost of the capillary structures.

[0024] In a possible design, along the circumference of the tube body, the first capillary structure is arranged around the inner tube surface in a circle.

[0025] In a possible design, the distance between two adjacent second capillary structures is 2-4 mm.

[0026] In a possible design, the distance from the surface of the protrusion to the second capillary structure is greater than 0.3 mm.

[0027] In a possible design, the thickness of the second capillary structure is 0.2-0.7 mm.

[0028] In a possible design, the width of the second capillary structure is 2-8 mm.

[0029] In a possible design, the thickness of the first capillary structure is 0.4-1.1 mm.

[0030] In a possible design, the material of the non-metallic fiber body includes glass fiber or carbon fiber.

[0031] In a possible design, the material of the foam metal includes copper or aluminum; the material of the metal braid includes copper or aluminum; and the material of the metal braid includes copper or aluminum.

[0032] In a second aspect, the present application also provides a radiator comprising a heat dissipation component, a heat conduction plate and a heat pipe as described above, wherein the heat dissipation component is sleeved on the condensation part of the heat pipe, and the heat conduction plate is fixed on the evaporation part of the heat pipe.

[0033] The radiator in the present application includes the above-mentioned heat pipe, the first capillary structure inside the heat pipe is made of a material with a larger capillary pressure, and the second capillary structure is made of a material with a larger permeability. Since the second capillary structure is wrapped inside the first capillary structure and is not exposed in the accommodating cavity, the inner surface of the accommodating cavity is the first capillary structure. Since the capillary pressure is a surface parameter, the capillary pressure in the heat pipe comes from the first capillary structure. Based on this case, driven by the larger capillary pressure of the first capillary structure, the liquid working fluid will flow back through the two channels of the first capillary structure and the second capillary structure at the same time, wherein the second capillary structure with low reflux resistance serves as a "high-speed channel" for the reflux of the liquid working fluid, which can quickly transfer the liquid working fluid to the evaporation part. Compared with the heat pipe with only the first capillary structure set alone, the heat pipe in the present application has a smaller reflux resistance, and compared with the heat pipe with only the second capillary structure set alone, the heat pipe in the present application has a greater driving force. Therefore, the design method of wrapping the second capillary structure with the first capillary structure makes the heat pipe in this application conducive to the reflux of the liquid working fluid, accelerates the liquid-gas phase circulation speed, and thus can improve the heat transfer capacity of the heat pipe, effectively prevents dry burning in the evaporation part and liquid accumulation in the condensation part, makes it difficult for the heat pipe to reach the heat transfer limit, and can effectively improve the heat dissipation power of the radiator.

[0034] In a third aspect, the present application also provides an electronic device comprising the above-mentioned radiator.

[0035] The electronic device may be any one of a laptop computer, a desktop computer, a tablet computer, a game console, a mobile phone, an electronic watch, a router, a set-top box, a television, and a modem. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic diagram of a heat pipe radiator in the related art;

[0037] FIG2 is a cross-sectional view taken along line AA in FIG1 ;

[0038] FIG3 is a cross-sectional view taken along line BB in FIG1 ;

[0039] FIG4 is a longitudinal cross-sectional view of a heat pipe provided in an embodiment of the present application;

[0040] FIG5 is a schematic diagram of the working principle of the heat pipe provided in an embodiment of the present application;

[0041] FIG6 is a cross-sectional view of a first example of a heat pipe provided in an embodiment of the present application;

[0042] FIG7 is a cross-sectional view of a second example of a heat pipe provided in an embodiment of the present application;

[0043] FIG8 is a cross-sectional view of a third example of a heat pipe provided in an embodiment of the present application;

[0044] FIG9 is a cross-sectional view of a fourth example of a heat pipe provided in an embodiment of the present application;

[0045] FIG10 is a cross-sectional view of a fifth example of a heat pipe provided in an embodiment of the present application;

[0046] FIG11 is a cross-sectional view of a sixth example of a heat pipe provided in an embodiment of the present application;

[0047] FIG12 is a cross-sectional view of a seventh example of a heat pipe provided in an embodiment of the present application;

[0048] FIG13 is a cross-sectional view of an eighth example of a heat pipe provided in an embodiment of the present application;

[0049] FIG14 is a cross-sectional view of a ninth example of a heat pipe provided in an embodiment of the present application;

[0050] FIG15 is a cross-sectional view of a tenth example of a heat pipe provided in an embodiment of the present application;

[0051] FIG16 is a cross-sectional view of an eleventh example of a heat pipe provided in an embodiment of the present application;

[0052] FIG17 is a cross-sectional view of a twelfth example of a heat pipe provided in an embodiment of the present application;

[0053] FIG18 is a cross-sectional view of a thirteenth example of a heat pipe provided in an embodiment of the present application;

[0054] FIG19 is a cross-sectional view of a fourteenth example of a heat pipe provided in an embodiment of the present application;

[0055] FIG20 is a cross-sectional view of a fifteenth example of a heat pipe provided in an embodiment of the present application;

[0056] FIG21 is a cross-sectional view of a sixteenth example of a heat pipe provided in an embodiment of the present application;

[0057] FIG22 is a cross-sectional view of a seventeenth example of a heat pipe provided in an embodiment of the present application;

[0058] FIG23 is a cross-sectional view of an eighteenth example of a heat pipe provided in an embodiment of the present application;

[0059] FIG24 is a cross-sectional view of a nineteenth example of a heat pipe provided in an embodiment of the present application;

[0060] Figure 25 is a schematic diagram of an electronic device provided in an embodiment of the present application.

[0061] Reference numerals:

[0062] 10. Tube body; 11. Accommodating cavity; 12. Inner tube surface; 13. Flat tube wall; 14. Curved tube wall; 20. First capillary structure; 21. Raised portion; 30. Second capillary structure; 40. Grooved capillary structure;

[0063] 51. Metal powder sintered body; 52. Metal braided mesh; 53. Metal foam; 54. Non-metallic fiber body; 55. Metal braided braid; 56. Non-metallic powder sintered body;

[0064] 100, heat pipe; 101, evaporation part; 102, condensation part; 103, capillary structure; 200, heat dissipation component; 300, heat conduction plate; 400, radiator; 500, electronic component. DETAILED DESCRIPTION

[0065] The following is an illustrative introduction to the relevant contents that may be involved in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments.

[0066] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0067] In the description of this application, it should be understood that the terms "upper", "lower", "side", "inside", "outside", "top", "bottom", etc. indicate orientations or positional relationships based on the installation, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0068] It should also be noted that, in the embodiments of the present application, the same reference numerals are used to represent the same component or the same part. For the same parts in the embodiments of the present application, the figure may only mark one of the parts or parts as an example. It should be understood that the reference numerals are also applicable to other identical parts or parts.

[0069] In the description of this application, it should be noted that the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0070] Electronic components are fundamental elements in electronic circuits, consisting of two or more leads or metal contacts. When interconnected, they form a functional electronic circuit. Soldering electronic components to a substrate is a common method of connecting electronic components. Electronic components can be individual packages, such as resistors, capacitors, inductors, transistors, and diodes, or groups of varying complexity, such as integrated circuits (ICs).

[0071] Electronic devices are composed of various electronic components such as integrated circuits, transistors, and vacuum tubes, and use electronic technology software to function. Examples include desktop computers, laptops, tablets, game consoles, mobile phones, electronic watches, routers, set-top boxes, televisions, modems, etc.

[0072] When electronic devices are operating, they generate heat, causing the internal temperature of the device to rise rapidly. The direct cause of this heat is the power consumption of the electronic components. All electronic components have varying degrees of power consumption, and the intensity of the heat generated varies with the amount of power consumed. If this heat is not dissipated promptly, the electronic components will continue to heat up and eventually fail due to overheating, which in turn leads to decreased functional stability of the electronic device or even complete functional failure. Furthermore, as electronic devices are increasingly moving towards miniaturization, thinness, and high performance, the integration of electronic components in electronic devices is also increasing, accompanied by increasing power consumption. How to quickly and effectively dissipate the heat generated by electronic components is a key issue that must be addressed in the development of electronic devices towards miniaturization, thinness, and high performance.

[0073] Capillary pressure-driven liquid flow and gas-liquid phase change phenomena are ubiquitous in nature and industrial processes, and play a very important role in many applications, such as seawater desalination and freshwater purification, microfluidic management, efficient heat and mass transfer, and especially the high-power density electronic component cooling mentioned above. The heat pipe radiator, temperature spreader, capillary microgroove evaporator, etc. used are all heat dissipation devices that use capillary pressure to drive the gas-liquid phase change phenomenon to achieve cooling.

[0074] Figure 1 is a schematic diagram of a heat pipe radiator in the related art. Figure 2 is a cross-sectional view taken along line AA in Figure 1. Figure 3 is a cross-sectional view taken along line BB in Figure 1.

[0075] As shown in Figures 1-3, a heat pipe radiator in related art is mainly composed of a heat pipe 100, a heat conducting plate 300, and a heat dissipation component 200 (such as a fin). Typically, one end of the heat pipe 100 serves as an evaporation portion 101, and the other end serves as a condensation portion 102. The evaporation portion 101 is attached to and in contact with the electronic component 500 via the heat conducting plate 300, while the condensation portion 102 is connected to the heat dissipation component 200. The heat pipe 100 has an internal cavity for encapsulating the working fluid (not shown in the figure).

[0076] As shown in Figure 3, when the electronic component 500 generates heat, the heat is transferred through the heat conducting plate 300 to the evaporation section 101 of the heat pipe 100. The working fluid inside the evaporation section 101 vaporizes and then flows through the cavity of the heat pipe 100 toward the cooler condensation section 102. At this time, the condensation section 102 releases heat through the external heat dissipation component 200, causing the vaporized working fluid to return to the liquid phase. The capillary pressure generated by the capillary structure 103 on the inner wall of the heat pipe 100 then pushes the liquid working fluid back to the evaporation section 101. This cycle repeats the heat transfer effect. The capillary performance of the capillary structure 103 represents the heat transfer performance of the heat pipe 100. The better the capillary performance, the stronger the heat transfer capacity of the heat pipe 100 and the higher the heat dissipation efficiency of the heat pipe radiator.

[0077] When evaluating the capillary performance of the capillary structure 103, capillary pressure and permeability are the two most important parameters. Capillary pressure reflects the driving force for liquid flow within the capillary structure 103, while permeability reflects the resistance encountered by the liquid as it flows within the capillary structure 103. When the porosity (i.e., the ratio of voids / pores to the total volume) of a capillary structure 103 is constant, a larger pore size leads to a higher permeability and lower flow resistance, but this results in lower capillary pressure, resulting in insufficient driving force and hindering liquid reflux. Conversely, a smaller pore size leads to higher capillary pressure but lower permeability, resulting in increased flow resistance, ultimately hindering liquid reflux.

[0078] The capillary structures 103 of the current mainstream heat pipes 100 include two types: copper powder sintered capillary structure and copper braided mesh capillary structure.

[0079] Most of the pores in the copper powder sintered capillary structure are very small, resulting in a high overall capillary pressure. This provides greater power for the gas-liquid circulation within the heat pipe 100 and exhibits excellent performance under counter-gravity conditions. However, the copper powder sintered capillary structure has a low permeability, which results in significant resistance to liquid flow within the capillary structure 103. As power gradually increases, the mass of the working fluid involved in the gas-liquid circulation increases. However, this excessive flow resistance makes it difficult for the liquid in the condenser section 102 to reflux, which in turn causes dry-burning in the evaporator section 101 of the heat pipe 100.

[0080] Compared with the copper powder sintered capillary structure, most of the pores in the copper woven mesh capillary structure are larger and have a higher overall permeability, which can reduce the flow resistance of the liquid working fluid during the circulation process. However, the capillary pressure of the copper woven mesh capillary structure is relatively small, which is not enough to provide the driving force required for liquid circulation, nor can it allow the liquid condensed in the condensation part 102 to quickly flow back to the evaporation part 101, resulting in the gradual deterioration of the heat transfer performance of the heat pipe 100.

[0081] It can be seen that how to balance the relationship between capillary pressure and permeability so that the capillary structure 103 can achieve a high permeability when having a large capillary pressure to reduce the resistance of liquid reflux becomes the key point of how to improve the heat transfer performance of the heat pipe 100.

[0082] In order to solve the above technical problems, the present application provides a heat pipe 100, a radiator 400 and an electronic device. By wrapping a first capillary structure 20 with a large capillary pressure with a second capillary structure 30 with a large permeability, the large driving force generated by the first capillary structure 20 and the low-resistance reflux channel established by the second capillary structure 30 are fully utilized, so that the working fluid in the heat pipe 100 can quickly and fully participate in the cyclic heat transfer work of the liquid-gas phase change, thereby improving the heat transfer performance of the heat pipe 100.

[0083] The heat pipe 100 provided in the present application will now be described in detail with reference to the accompanying drawings.

[0084] FIG4 is a longitudinal cross-sectional view of the heat pipe 100 provided in an embodiment of the present application. FIG5 is a cross-sectional view of a first example of the heat pipe 100 provided in an embodiment of the present application. A longitudinal cross-section refers to the surface presented after the heat pipe 100 is cut along the axis of the heat pipe 100, similar to the cross-sectional surface of the heat pipe 100 taken at line BB in FIG1 ; a cross-sectional view refers to the surface exposed after the heat pipe 100 is cut in a direction perpendicular to the axis of the heat pipe 100, similar to the cross-sectional surface of the heat pipe 100 taken at line AA in FIG1 .

[0085] As shown in FIG. 4 and FIG. 5 , an embodiment of the present application provides a heat pipe 100 , which includes a pipe body 10 , a first capillary structure 20 , and a second capillary structure 30 .

[0086] The interior of the tube body 10 has a receiving cavity 11 for sealing a working fluid (not shown in the figure). The two ends of the tube body 10 are respectively an evaporation portion 101 and a condensation portion 102.

[0087] The first capillary structures 20 are distributed along the axial direction (or length direction) of the tube body 10 , and the first capillary structures 20 are attached to the inner tube surface 12 of the tube body 10 .

[0088] The second capillary structure 30 is also distributed along the axial direction of the tube body 10 , and the second capillary structure 30 is wrapped inside the first capillary structure 20 ;

[0089] The first capillary structure 20 and the second capillary structure 30 are configured such that: the capillary pressure of the first capillary structure 20 is greater than the capillary pressure of the second capillary structure 30 , and the permeability of the second capillary structure 30 is greater than the permeability of the first capillary structure 20 .

[0090] FIG6 is a schematic diagram of the working principle of the heat pipe 100 provided in an embodiment of the present application. The dotted arrows in FIG6 indicate the flow direction of the gas-phase working fluid formed by evaporation after absorbing heat from the evaporation portion 101, and the solid arrows indicate the flow direction of the liquid-phase working fluid formed by condensation after releasing heat from the condensation portion 102.

[0091] As shown in FIG6 , when the electronic component 500 generates heat during operation, the heat is transferred to the evaporation section 101 of the heat pipe 100 through the heat conducting plate 300 . The first capillary structure 20 attached to the inner tube surface 12 of the heat pipe body 10 evaporates the liquid-phase working fluid into a vapor-phase working fluid. This evaporation and vaporization process generates a local high pressure in the evaporation section 101, causing the vapor-phase working fluid to flow toward the condensation section 102 under the action of pressure. The vapor-phase working fluid, upon encountering the cold in the condensation section 102, condenses into a liquid-phase working fluid. During the condensation process, the heat is released and transferred to the condensation section 102, where it is dissipated into the environment through the heat dissipation assembly 200 . The liquid-phase working fluid then seeps into the first and second capillary structures 20, 30 of the condensation section 102. Driven by the capillary pressure of the first capillary structure 20, the liquid-phase working fluid refluxes through the reflux channel established by the first and second capillary structures 20, 30, ultimately returning to the evaporation section 101 to continue the liquid-to-vapor phase heat transfer cycle.

[0092] The first capillary structure 20 is made of a material with a high capillary pressure, and the second capillary structure 30 is made of a material with a high permeability. Furthermore, since the second capillary structure 30 is enclosed within the first capillary structure 20 and not exposed within the accommodating cavity 11, the entire inner surface of the accommodating cavity 11 is the first capillary structure 20. Furthermore, since capillary pressure is a surface parameter, the capillary pressure within the heat pipe 100 is derived entirely from the first capillary structure 20. In this case, driven by the higher capillary pressure of the first capillary structure 20, the liquid working fluid will simultaneously reflux through both the first capillary structure 20 and the second capillary structure 30. The second capillary structure 30, with its low reflux resistance, serves as a "high-speed channel" for the reflux of the liquid working fluid, rapidly transferring the liquid working fluid to the evaporation portion 101. Compared to a heat pipe 100 having only the first capillary structure 20, the heat pipe 100 in the embodiment of the present application has a smaller reflux resistance, and compared to a heat pipe 100 having only the second capillary structure 30, the heat pipe 100 in the embodiment of the present application has a greater driving force. Therefore, the design of the first capillary structure 20 enveloping the second capillary structure 30 facilitates the reflux of the liquid working fluid in the heat pipe 100 in the embodiment of the present application, accelerates the liquid-gas cycle speed, and thus improves the heat transfer capacity of the heat pipe 100. It can effectively prevent dry burning in the evaporation section 101 and liquid accumulation in the condensation section 102, making it less likely for the heat pipe 100 to reach its heat transfer limit.

[0093] In addition, since the liquid-phase working fluid can flow back to the evaporation portion 101 along the second capillary structure 30, it will not conflict with the gas-phase working fluid in the accommodating cavity 11, thereby isolating the gas-phase working fluid from the liquid-phase working fluid, so that the gas-phase working fluid will not be obstructed in the opposite flow with the returning liquid-phase working fluid, thereby making the liquid-gas phase change cycle in the heat pipe 100 smoother.

[0094] In addition, since the liquid working fluid in the condensation section 102 can be quickly transferred back to the evaporation section 101, the accumulation of liquid in the condensation section 102 can be avoided, thereby effectively avoiding the problem of abnormal noise and improving the user experience. The specific reason is that the heat pipe 100 in the related art has defects in the design of its capillary structure 103, which makes it difficult for the liquid working fluid to reflux, and it is easy for a large amount of liquid to accumulate in the condensation section 102. When the heat pipe 100 or the electronic device is turned over, the large amount of liquid accumulated in the condensation section 102 will hit the inner wall of the heat pipe 100, making a sound of water droplets, which in turn affects the user experience.

[0095] In summary, the heat pipe 100 in the embodiment of the present application forms a tunnel-type composite capillary structure with a high-speed reflux channel in the heat pipe 100 by wrapping the first capillary structure 20 with a large capillary pressure with the second capillary structure 30 with a large permeability. The advantages of the large driving force generated by the first capillary structure 20 and the low reflux resistance of the second capillary structure 30 are fully utilized, so that the working fluid in the heat pipe 100 quickly and fully participates in the cyclic heat transfer of the liquid-gas phase change, thereby improving the heat transfer performance of the heat pipe 100.

[0096] Optionally, the working fluid may be any liquid that is conducive to evaporative heat dissipation, and may be water, an inorganic compound, an organic compound, a liquid metal, a refrigerant, or a mixture of two or more of the foregoing, all of which may be the working fluid used in the embodiments of the present application.

[0097] Specifically, when the working fluid is water, distilled water or deionized water may be used.

[0098] Specifically, when the working fluid is an organic compound, at least one of ethanol, methanol, and acetone may be used.

[0099] Optionally, the size of the accommodating cavity 11 can be determined based on the power consumption of the electronic component 500. When the power consumption of the electronic component 500 is high, more heat is generated. In this case, the accommodating cavity 11 can be larger to accommodate more working fluid and increase the heat conduction rate. When the power consumption of the electronic component 500 is low, the heat generated by the electronic component 500 is low. In this case, a smaller accommodating cavity 11 can still achieve the purpose of heat conduction. This can also reduce the filling amount of the working fluid, thereby reducing the manufacturing cost of the heat pipe 100.

[0100] Optionally, the first capillary structure 20 may be formed of at least one of a metal powder sintered body 51 , a non-metal powder sintered body 56 , and a metal braided mesh 52 , but is not limited thereto.

[0101] Among them, sintering refers to the mutual bonding of solid particles of raw material green body at high temperature (not higher than melting point), grain growth, gradual reduction of pores and grain boundaries, and through the transfer of matter, the total volume shrinks and the density increases, finally becoming a dense polycrystalline sintered body with a certain microstructure. This phenomenon is called sintering process.

[0102] The metal powder sintered body 51 may include, but is not limited to, being formed by sintering copper powder, while the non-metallic powder sintered body 56 may include, but is not limited to, being formed by sintering ceramic powder. The pores of the metal powder sintered body 51 and the non-metallic powder sintered body 56 are mostly small, resulting in a high capillary pressure, which can provide a greater driving force for the gas-liquid circulation within the heat pipe 100.

[0103] The metal mesh 52 is a mesh structure formed by interlacing multiple metal wires. When the metal mesh 52 serves as the first capillary structure 20, the gaps between the wires in the evaporation section 101 serve as evaporation channels for the liquid working fluid to evaporate into the gas phase. In areas other than the evaporation section 101, the gaps between the wires also serve as recirculation channels for the liquid working fluid. When the metal mesh 52 serves as the second capillary structure 30, the gaps between the wires serve as recirculation channels for the liquid working fluid.

[0104] The metal wires used in the metal mesh 52 are made of copper or aluminum. Compared to the metal braid 55, the metal mesh 52 has smaller gaps and a higher overall capillary pressure, providing a greater driving force for gas-liquid circulation within the heat pipe 100. Therefore, when the metal mesh 52 forms the first capillary structure 20, the second capillary structure 30 is formed by the metal braid 55. For details, see the embodiments described below.

[0105] Optionally, the second capillary structure 30 may be formed of at least one of foam metal 53 , non-metallic fiber body 54 , metal braided mesh 52 , and metal braided braid 55 , but is not limited thereto.

[0106] The metal foam 53 refers to a special metal material containing foam pores. The pores within it form a high-speed recirculation channel for the liquid-phase working fluid. Examples of the metal foam 53 that can be used to form the second capillary structure 30 in this application include aluminum foam, nickel foam, and copper foam. Compared to the metal powder sintered body 51 and the non-metallic powder sintered body 56, the metal foam 53 has a larger pore size and a higher overall permeability, thereby reducing the flow resistance of the liquid-phase working fluid during circulation.

[0107] There are many methods for preparing the metal foam 53. Depending on the physical state of the metal or alloy being processed, the methods for obtaining the metal foam material can be divided into liquid phase method, powder solid phase method, ion method (metal ion solution), and gas absorption phase method (metal vapor or gaseous intermetallic compound). Among them, gas injection method, melt foaming method, powder metallurgy method, and infiltration casting method are the most commonly used preparation methods.

[0108] Optionally, the non-metal fiber body 54 in the present application includes but is not limited to a glass fiber body or a carbon fiber body.

[0109] Specifically, glass fiber is an inorganic, non-metallic material with excellent performance. It is made from six minerals: pyrophyllite, quartz sand, limestone, dolomite, colemanite, and magnesia. It is manufactured through processes such as high-temperature melting, wire drawing, winding, and weaving. It is commonly used as a reinforcing material in composite materials, as an electrical insulating material, and as a thermal insulation material. In this application, the glass fiber body that can constitute the second capillary structure 30 is also known as glass wool. It is a fixed-length glass fiber with relatively short fibers, generally less than 150 mm or shorter. Its structure is fluffy, similar to cotton wool, and it has a large number of pores within it, which serve as the return path for the liquid working fluid.

[0110] Specifically, carbon fiber refers to high-strength and high-modulus fiber with a carbon content of more than 90%. In this application, the carbon fiber body that can constitute the second capillary structure 30 is a porous material woven from carbon fibers, and the pores inside it are the reflux channels of the liquid working fluid.

[0111] Whether it is a glass fiber body or a carbon fiber body, compared with the metal powder sintered body 51 and the non-metallic powder sintered body 56, most of the pores of the glass fiber body or the carbon fiber body are larger and have a larger overall permeability, thereby reducing the flow resistance of the liquid working fluid during the circulation process.

[0112] The metal braid 55 is a bundle of multiple metal wires twisted in a spiral shape, similar to the pigtail shape in women's hairstyles. Similar to the metal braid 52, the gaps between the metal wires in the metal braid 55 are the return channels for the liquid phase working fluid.

[0113] The metal braid 55 is made of copper or aluminum. Compared to the metal powder sintered body 51, the non-metallic powder sintered body 56, and the metal braid 52, the metal braid 55 has larger gaps and a higher overall permeability, thereby reducing the flow resistance of the liquid working fluid during circulation.

[0114] Optionally, the capillary structure design of the heat pipe 100 in the present application can also be applied to a temperature-averaging plate. The temperature-averaging plate includes an evaporation region in the middle and a condensation region surrounding the evaporation region. The first capillary structure 20 is attached to the inner wall of the temperature-averaging plate, and multiple second capillary structures 30 are distributed in a divergent manner, starting from the evaporation region and pointing towards the condensation region. The second capillary structure 30 is wrapped inside the first capillary structure 20. The capillary pressure of the first capillary structure 20 is greater than the capillary pressure of the second capillary structure 30, and the permeability of the second capillary structure 30 is greater than the permeability of the first capillary structure 20.

[0115] In an embodiment provided in the present application, the heat pipe 100 further includes a groove capillary structure 40 provided on the inner tube surface 12. For example, as shown in FIG. 16 below, the details can be found in the embodiments described below.

[0116] In an embodiment provided in the present application, the heat pipe 100 further includes a grooved capillary structure 40 provided on the second capillary structure 30. For example, this is shown in FIG14 in the embodiment described later.

[0117] In an embodiment provided in the present application, the heat pipe 100 further includes a grooved capillary structure 40 provided on the inner tube surface 12 and the second capillary structure 30 .

[0118] In the above-mentioned embodiments, the additional groove capillary structure 40 can further improve the permeability of the entire heat pipe 100 , thereby further reducing the backflow resistance of the liquid-phase working fluid.

[0119] Optionally, as shown in FIG6 , the second capillary structure 30 can be completely wrapped inside the first capillary structure 20. However, in this way, the second capillary structure 30 is not easy to position during the processing and manufacturing stage. For example, the first capillary structure 20 is formed by a metal powder sintered body 51, and the second capillary structure 30 is formed by a foam metal 53. During the manufacturing process, the core rod is first placed in the tube body 10 so that a gap is formed between the core rod and the inner tube wall for forming the first capillary structure 20. The foam metal 53 and the metal powder to be sintered are then placed in turn. Finally, the metal powder is solidified and the foam metal 53 is tightly wrapped therein through a heating and sintering process. It can be found that since there is no supporting surface on all sides of the foam metal 53, the foam metal 53 cannot be accurately positioned in the metal powder, which can easily cause deviation and cause the metal powder on the surface of the foam metal 53 to be too thin, thereby affecting the capillary performance of the entire heat pipe 100.

[0120] FIG7 is a cross-sectional view of a second example of the heat pipe 100 provided in an embodiment of the present application.

[0121] In order to solve the above problems and facilitate implementation and manufacturing, as shown in FIG7 , in an embodiment provided in the present application, the side of the second capillary structure 30 facing the inner tube surface 12 is exposed from the first capillary structure 20 and abuts against the inner tube surface 12 .

[0122] Taking the example that the first capillary structure 20 is composed of a metal powder sintered body 51 and the second capillary structure 30 is composed of a foam metal 53, during manufacturing and processing, a simple auxiliary tool (such as a support arm) can be first inserted into the gap to hold the foam metal 53 against the inner tube surface 12, and then the metal powder can be loaded. At this time, the loaded metal powder can already form a pre-positioning for the foam metal 53. Then remove the auxiliary tool and continue to fill the gap left by the auxiliary tool. After it is filled, the foam metal 53 can be accurately restricted.

[0123] It can be seen that in this embodiment, the side of the second capillary structure 30 facing the inner tube surface 12 is exposed from the first capillary structure 20 and abuts against the inner tube surface 12, so that one side of the second capillary structure 30 has a force support surface, thereby facilitating the positioning of the second capillary structure 30 and facilitating implementation and processing.

[0124] Optionally, in an embodiment provided in the present application, the groove capillary structure 40 is provided at the portion where the second capillary structure 30 abuts against the inner tube surface 12 , which is easier to process and manufacture. Please refer to the following for an understanding of this advantage.

[0125] Taking the example of a first capillary structure 20 formed of a sintered metal powder body 51 and a second capillary structure 30 formed of a metal foam 53, during manufacturing, the grooved capillary structure 40 is located where the metal foam 53 and the inner tube surface 12 abut. This allows the metal foam 53 to block the grooved capillary structure 40, making it difficult for metal powder to enter the groove during loading, thereby facilitating manufacturing. Otherwise, the groove would need to be protected to prevent metal powder from accidentally filling it.

[0126] FIG8 is a cross-sectional view of a third example of the heat pipe 100 provided in an embodiment of the present application.

[0127] As shown in FIG. 8 , in an embodiment provided in the present application, there are multiple second capillary structures 30 , and the multiple second capillary structures 30 are arranged at intervals along the circumference of the tube body 10 .

[0128] In this embodiment, the plurality of second capillary structures 30 arranged at intervals can further increase the reflux velocity of the liquid-phase working fluid and thus enhance the heat transfer capability of the heat pipe 100 .

[0129] Optionally, the plurality of second capillary structures 30 may be made of the same material.

[0130] For example, the two second capillary structures 30 are both made of foam metal 53 .

[0131] For another example, the three second capillary structures 30 are all formed by the metal braided mesh 52 .

[0132] For another example, the four second capillary structures 30 are all formed by metal braids 55 .

[0133] Optionally, the plurality of second capillary structures 30 may also be made of different materials.

[0134] For example, the two second capillary structures 30 are respectively composed of foam metal 53 and non-metal fiber body 54 .

[0135] For another example, the three second capillary structures 30 are respectively composed of two foam metals 53 and one metal braided mesh 52 .

[0136] For another example, the four second capillary structures 30 are respectively composed of foam metal 53 , non-metallic fiber body 54 , metal braided mesh 52 , and metal braided braid 55 .

[0137] As shown in FIG. 8 , in an embodiment provided in the present application, the spacing distance L1 between the plurality of second capillary structures 30 is 2-4 mm.

[0138] FIG9 is a cross-sectional view of a fourth example of the heat pipe 100 provided in an embodiment of the present application.

[0139] As shown in FIG. 9 , in an embodiment provided in the present application, the first capillary structure 20 has a protrusion 21 at a portion corresponding to the second capillary structure 30 .

[0140] The raised portion 21 in this embodiment is designed to ensure that the portion of the first capillary structure 20 corresponding to the second capillary structure 30 has sufficient thickness, so that the first capillary structure 20 can have sufficient wrapping and fixing strength with the second capillary structure 30, and avoid the second capillary structure 30 being easily detached due to being too thin at this portion. This improves the shock resistance of the heat pipe 100 and ensures the structural stability of the first capillary structure 20 and the second capillary structure 30 even during severe vibration, thereby improving the reliability of the heat pipe 100.

[0141] As shown in FIG. 9 , in an embodiment provided in the present application, the edge of the protrusion 21 transitions smoothly with the surface of the first capillary structure 20 .

[0142] In this embodiment, the edge of the protrusion 21 is smoothly transitioned to the surface of the first capillary structure 20, so as to avoid the protrusion 21 from having sharp corners that interfere with the flow of air. When the gas-phase working fluid of the evaporation section 101 flows toward the condensation section 102, the protrusion 21 in this embodiment can reduce the obstruction effect on the gas-phase working fluid, so that the gas-phase working fluid can also flow quickly to the condensation section 102, thereby accelerating the liquid-gas phase circulation speed, and can improve the heat transfer capacity of the heat pipe 100, so that the hot and cold ends of the heat pipe 100 have good temperature uniformity, making it less likely to reach the heat transfer limit.

[0143] As shown in FIG9 , in one embodiment provided by the present application, the distance L2 from the surface of the protrusion 21 to the second capillary structure 30 is greater than 0.3 mm. For example, L2 is 0.35 mm, 0.4 mm, 0.45 mm, etc., and can be adjusted according to the size of the accommodating cavity 11 .

[0144] The distance L2 from the surface of the protrusion 21 to the second capillary structure 30 can also be understood as the thickness of the first capillary structure 20 within the upper surface of the second capillary structure 30 as shown in FIG. 9 .

[0145] In this embodiment, the distance from the surface of the protrusion 21 to the second capillary structure 30 is further limited, ie, L2>0.3 mm, so that the protrusion 21 can fully cover the second capillary structure 30 and ensure that the second capillary structure 30 is reliably fixed inside the first capillary structure 20.

[0146] As shown in FIG8 , in some embodiments provided herein, the thickness L3 of the second capillary structure 30 is 0.2-0.7 mm. For example, L3 is 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, etc., and can be adjusted according to the power consumption of the electronic component 500 .

[0147] The thickness L3 of the second capillary structure 30 can also be understood as the thickness of the second capillary structure 30 in the Z direction as shown in FIG. 8 .

[0148] As shown in FIG8 , in some embodiments provided herein, the width L5 of the second capillary structure 30 is 2-8 mm. For example, L5 is 2 mm, 5 mm, 6 mm, 7 mm, 8 mm, etc., and can be adjusted according to the power consumption of the electronic component 500 .

[0149] The width L5 of the second capillary structure 30 can also be understood as the width of the second capillary structure 30 in the X direction as shown in FIG. 8 .

[0150] As shown in FIG8 , in some embodiments provided herein, the thickness L6 of the first capillary structure 20 is 0.4-1.1 mm, for example, L6 is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.1 mm, etc.

[0151] The thickness L6 of the first capillary structure 20 can also be understood as the thickness of the first capillary structure 20 in the Z direction as shown in FIG. 8 .

[0152] Alternatively, the heat pipe 100 in the present application may be cylindrical or flat. Various styles of heat pipes 100 may be applicable to different types of electronic devices and may be flexibly selected according to the internal layout space of the electronic device.

[0153] FIG10 is a cross-sectional view of a fifth example of a heat pipe 100 provided in an embodiment of the present application.

[0154] As shown in Figure 10, in one embodiment provided in the present application, the heat pipe 100 is cylindrical, that is, the cross-sectional shape of the tube body 10 is circular, and along the circumference of the tube body 10, the first capillary structure 20 is arranged around the inner tube surface 12 in a circle, and multiple second capillary structures 30 are also arranged at intervals along the circumference of the tube body 10.

[0155] FIG11 is a cross-sectional view of a sixth example of the heat pipe 100 provided in an embodiment of the present application.

[0156] As mentioned above, the heat pipe 100 may also be flat, that is, as shown in one embodiment provided in the present application, the pipe body 10 includes two opposite flat pipe walls 13 and two opposite arc-shaped pipe walls 14 as shown in FIG. 11 .

[0157] In this embodiment, the flat heat pipe 100 can be applied to electronic devices with thickness restrictions, so that the heat pipe 100 can meet the design requirements of lightness and thinness.

[0158] When the heat pipe 100 is flat, as shown in FIG11 , the first capillary structure 20 is arranged around the inner tube surface 12 along the circumference of the tube body 10 , that is, the first capillary structure 20 completely covers the inner tube surface 12 of the tube body 10 .

[0159] Alternatively, Figure 12 is a cross-sectional view of a seventh example of the heat pipe 100 provided in an embodiment of the present application. As shown in Figure 12, in an embodiment provided in the present application, the first capillary structure 20 and the second capillary structure 30 are arranged on either of the two flat tube walls 13.

[0160] Among them, when the heat pipe 100 is flat, in fact only the flat tube wall 13 facing the heat conducting plate 300 is used to contact the electronic component 500 for heat exchange. Therefore, the first capillary structure 20 and the second capillary structure 30 can be set only on the flat tube wall 13, which can reduce the material cost used to manufacture the capillary structure.

[0161] When the heat pipe 100 is flat, the first capillary structure 20 completely covers or partially covers the inner tube surface 12 of the tube body 10 , and there may be various design types, as shown in Table 1 below.

[0162] Table 1 Summary of design parameters of flat heat pipes

[0163] As mentioned above, the heat pipe 100 can be cylindrical or flat. When manufacturing the flat heat pipe 100, a cylindrical heat pipe 100 with a set diameter D can be first manufactured, and then the cylinder can be pressed into a flat shape with a set thickness d by a hydraulic device to form the flat heat pipe 100. D6, D8, D10, and D12 in Table 1 represent the diameter models of the cylindrical heat pipe blanks used to manufacture the flat heat pipe 100. For example, D6 indicates that the flat heat pipe 100 is processed from a cylindrical heat pipe blank with a diameter D of 6 mm.

[0164] In addition, the thickness d mentioned here refers to the overall thickness of the flat heat pipe 100 , which can be understood as: as shown in FIG. 8 , the overall thickness d of the heat pipe 100 in the Z direction.

[0165] FIG13 is a cross-sectional view of an eighth example of the heat pipe 100 provided in an embodiment of the present application.

[0166] As shown in FIG. 13 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51 , and the second capillary structure 30 is composed of a foam metal 53 .

[0167] Compared with the prior art, the advantages of this embodiment are as follows: placing the foam metal 53 inside the metal powder sintered body 51 not only makes the heat pipe 100 have a larger capillary force and smaller reflux resistance, but also ensures that both the metal powder sintered body 51 and the foam metal 53 have sufficient strength after the metal powder sintered body 51 completely wraps the foam metal 53, thereby improving the shock resistance and reliability of the capillary structure inside the heat pipe 100.

[0168] FIG14 is a cross-sectional view of a ninth example of the heat pipe 100 provided in an embodiment of the present application.

[0169] As shown in FIG. 14 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a non-metallic powder sintered body 56 , the second capillary structure 30 is composed of a foam metal 53 , and a groove capillary structure 40 is provided on the foam metal 53 .

[0170] In addition to the advantages of the above embodiments, the groove capillary structure 40 added in this embodiment can further improve the permeability of the entire heat pipe 100, thereby further reducing the backflow resistance of the liquid-phase working fluid.

[0171] FIG15 is a cross-sectional view of a tenth example of the heat pipe 100 provided in an embodiment of the present application.

[0172] As shown in FIG. 15 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51 , and the second capillary structure 30 is composed of a non-metallic fiber body 54 .

[0173] FIG16 is a cross-sectional view of an eleventh example of the heat pipe 100 provided in an embodiment of the present application.

[0174] As shown in FIG. 16 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51 , the second capillary structure 30 is composed of a metal woven mesh 52 , and a grooved capillary structure 40 is provided on the inner tube surface 12 .

[0175] FIG17 is a cross-sectional view of a twelfth example of the heat pipe 100 provided in an embodiment of the present application.

[0176] As shown in FIG. 17 , in an embodiment provided in the present application, the first capillary structure 20 is formed of a metal powder sintered body 51 , and the second capillary structure 30 is formed of a metal braid 55 .

[0177] FIG18 is a cross-sectional view of the thirteenth example of the heat pipe 100 provided in an embodiment of the present application.

[0178] As shown in FIG. 18 , in an embodiment provided in the present application, the first capillary structure 20 is formed of a metal braided mesh 52 , and the second capillary structure 30 is formed of a metal braided braid 55 .

[0179] FIG19 is a cross-sectional view of the fourteenth example of the heat pipe 100 provided in an embodiment of the present application.

[0180] As shown in FIG. 19 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal braided mesh 52 , the second capillary structure 30 is composed of a metal braided braid 55 , and a grooved capillary structure 40 is provided on the inner tube surface 12 .

[0181] FIG20 is a cross-sectional view of the fifteenth example of the heat pipe 100 provided in an embodiment of the present application.

[0182] As shown in FIG. 20 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51 , and the second capillary structure 30 has two, respectively composed of a metal braided mesh 52 and a metal braided braid 55 .

[0183] FIG21 is a cross-sectional view of the sixteenth example of the heat pipe 100 provided in an embodiment of the present application.

[0184] As shown in Figure 21, in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51, and the second capillary structure 30 is composed of a foam metal 53. A groove capillary structure 40 is provided on the foam metal 53, and a rectangular protrusion 21 is provided on the portion of the metal powder sintered body 51 corresponding to the foam metal 53.

[0185] Optionally, similar to this embodiment, in the other embodiments mentioned above, no matter what material is used for the first capillary structure 20, the portion corresponding to the second capillary structure 30 has a rectangular protrusion 21, and the protrusion 21 can strongly fix the second capillary structure 30 to prevent the second capillary structure 30 from falling off.

[0186] FIG22 is a cross-sectional view of the seventeenth example of the heat pipe 100 provided in an embodiment of the present application.

[0187] As shown in Figure 22, in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51, and the second capillary structure 30 is composed of a foam metal 53. A groove capillary structure 40 is provided on the foam metal 53, and the corresponding part of the foam metal 53 has a protrusion 21, and the edge of the protrusion 21 smoothly transitions to the surface of the foam metal 53.

[0188] Optionally, similar to the present embodiment, in the other embodiments mentioned above, no matter what material is selected for the first capillary structure 20, the portion corresponding to the second capillary structure 30 has a protrusion 21, and the edge of the protrusion 21 smoothly transitions to the surface of the first capillary structure 20, thereby avoiding the protrusion 21 from having sharp corners that interfere with the flow of air. When the gas-phase working fluid in the evaporation section 101 flows toward the condensation section 102, the protrusion 21 can reduce the obstruction effect on the gas-phase working fluid, so that the gas-phase working fluid can also flow quickly to the condensation section 102, thereby accelerating the liquid-gas phase circulation speed.

[0189] FIG23 is a cross-sectional view of the eighteenth example of the heat pipe 100 provided in an embodiment of the present application.

[0190] As shown in Figure 23, in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51, and the second capillary structure 30 has two, which are respectively composed of a metal woven mesh 52 and a metal woven braid 55, and the parts of the metal powder sintered body 51 corresponding to the metal woven mesh 52 and the metal woven braid 55 both have protrusions 21.

[0191] Optionally, similar to this embodiment, in other embodiments, when there are multiple second capillary structures 30, the first capillary structure 20 has a protrusion 21 at a location corresponding to each second capillary structure 30. The protrusion 21 can be rectangular or have smooth edges.

[0192] FIG24 is a cross-sectional view of the nineteenth example of the heat pipe 100 provided in an embodiment of the present application.

[0193] As shown in FIG. 24 , in an embodiment provided in the present application, the first capillary structure 20 is composed of a metal powder sintered body 51 , and the second capillary structure 30 is composed of a metal woven mesh 52 .

[0194] In this embodiment, the metal powder specifically used is copper powder with a particle size between 50-200 μm, and the metal braided mesh 52 is woven with copper wire with a wire diameter of 0.03-0.06 mm (for example, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, etc.). The number of single-strand braids can be selected from 6 to 15 (for example, 6, 8, 13, 15, etc.) to be woven into one strand, and the number of copper wire strands can be selected from 12 to 24 (for example, 12, 16, 20, 24, etc.) to be woven into the final copper wire. The final number of copper wire braiding layers can be selected from 1 to 4 layers, and the thickness of the copper powder sintered body on the upper layer of the copper wire braided mesh is controlled to be greater than 0.3 mm to ensure that the copper powder layer can fully cover the copper wire.

[0195] In the above formula, k x represents the total permeability inside the heat pipe 100 , k1 represents the permeability of the first capillary structure 20 , k2 represents the permeability of the second capillary structure 30 , A1 represents the cross-sectional area of ​​the first capillary structure 20 , and A2 represents the cross-sectional area of ​​the second capillary structure 30 .

[0196] In this embodiment, the first capillary structure 20 uses a copper powder sintered body with high capillary pressure, and the second capillary structure 30 uses a copper wire mesh with high permeability. Compared with the heat pipe 100 that only uses a single copper powder sintered body as the capillary structure, this embodiment can reduce the flow resistance of the liquid working fluid in the heat pipe 100. According to simulation calculations, the liquid flow resistance can be reduced by approximately 20-40%.

[0197] In addition, a comparative test will be conducted below on the radiator 400 including the heat pipe 100 in this embodiment. For ease of understanding, the technical terms involved below will be explained and described below.

[0198] The heat dissipation power of a radiator refers to the amount of heat that the radiator 400 can dissipate per unit time, usually in watts (W), and is an important indicator for measuring the heat dissipation capacity of the radiator 400. The heat dissipation power of the radiator 400 is affected by many factors, and the common factors are as follows: First, the area of ​​the radiator 400. The larger the area of ​​the radiator 400, the more heat the radiator 400 can bear, and the stronger the heat dissipation capacity. Second, the thermal conductivity of the material. The higher the thermal conductivity of the material of the radiator 400, the higher the heat transfer efficiency and the stronger the heat dissipation capacity. Third, the fan speed. The fan in the radiator 400 can accelerate the air flow, increase the heat transfer, and thus improve the heat dissipation capacity.

[0199] In the control experiment described below, the heat pipe 100 of this embodiment and the heat sink 400 using the heat pipe 100 were used. Compared to the control group, the heat pipe 100 model, pipe wall material, number of heat pipes 100, heat dissipation assembly 200, and fan parameters were all the same. The only difference was the capillary structure within the heat pipe 100, as detailed below.

[0200] A flat heat pipe 100 with an overall thickness of 2.5 mm was pressed from a D12 cylindrical heat pipe blank. The capillary structure design employed a first capillary structure 20 comprised of sintered copper powder, and a second capillary structure 30 comprised of a braided copper wire mesh. This heat pipe 100 was tested in a prototype and compared to a conventional heat pipe manufacturer's design featuring an all-copper sintered capillary structure (hereinafter referred to as the all-copper solution). The test data is shown in Table 2.

[0201] Table 2 Verification test data

[0202] The heat sources used during the test are the CPU and GPU, and the CPU and GPU are thermally connected by the same heat pipe 100. A single heat source test involves testing the heat pipe 100 with only the CPU or GPU powered on; a dual heat source test involves testing the heat pipe 100 with both the CPU and GPU powered on simultaneously.

[0203] As can be seen from the test data in Table 2, the composite capillary solution in the embodiment of the present application has a better heat dissipation power gain than the all-copper powder solution under the single heat source and dual heat source test conditions, when the temperature difference between the hot and cold ends of the heat pipe 100 is less than 5°C. Specifically,

[0204] For the heat pipe 100 using the capillary solution of the embodiment of the present application, when the cooling power of the single heat source test is 120W, the temperature difference between the hot and cold ends of the GPU side heat pipe 100 is only 0.95°C, and the temperature difference between the hot and cold ends of the CPU side heat pipe 100 is only 2.92°C. It can be reasonably inferred that when the temperature difference between the hot and cold ends of the heat pipe 100 is 5°C, the cooling power of the heat pipe 100 using the capillary solution of the embodiment of the present application must be greater than 120W; on the other hand, when the cooling power of the heat pipe using the full copper powder solution is 120W in the single heat source test, the temperature difference between the hot and cold ends of the CPU side heat pipe is 5.14°C, which exceeds the requirement that the temperature difference between the hot and cold ends is less than 5°C. Therefore, the cooling power of the heat pipe using the full copper powder solution is significantly smaller, and is expected to be around 100-110W.

[0205] For the heat pipe 100 using the capillary solution of the embodiment of the present application, when the cooling power of the dual heat source test is 40W (GPU) + 120W (CPU), the temperature difference between the hot and cold ends of the GPU side heat pipe is only 1.52°C, and the temperature difference between the hot and cold ends of the CPU side heat pipe 100 is only 2.19°C. It can be reasonably inferred that when the temperature difference between the hot and cold ends of the heat pipe 100 is 5°C, the cooling power of the heat pipe 100 using the capillary solution of the embodiment of the present application must be greater than 40W (GPU) + 120W (CPU); on the other hand, for the heat pipe using the all-copper powder solution, when the cooling power of the dual heat source test is 40W (GPU) + 120W (CPU), the temperature difference between the hot and cold ends of the CPU side heat pipe is 5.67°C, which exceeds the requirement that the temperature difference between the hot and cold ends is less than 5°C. Therefore, the cooling power of the heat pipe using the all-copper powder solution is significantly lower, and is expected to be between 40W (GPU) + 100 and 110W (CPU).

[0206] The composite capillary heat pipe 100 and the all-copper powder heat pipe of the present embodiment were installed in a laptop computer and tested for single and dual heat source functionality. The test data are shown in Tables 3 and 4.

[0207] Table 3 Functional test data of the heat pipe 100 of the embodiment of the present application

[0208] Table 4: Functional test data of the heat pipe with copper powder capillary solution

[0209] In the complete device function test, and the single heat source test, only the CPU is tested. The junction temperatures in the table refer to the actual operating temperatures of the electronic components.

[0210] By comparing Table 3 and Table 4, it can be seen that in the single heat source test, the CPU junction temperature of the heat pipe 100 using the capillary solution in the embodiment of the present application is 97.798°C, while the CPU junction temperature of the heat pipe using the full copper powder solution is 100°C. It can be seen that the use of the heat pipe 100 in the embodiment of the present application can reduce the CPU operating temperature by about 2-3°C.

[0211] In terms of power, the CPU power of the heat pipe 100 using the capillary solution in the embodiment of the present application is 70.123W, while the CPU power of the heat pipe using the full copper powder solution is 69.905W. It can be seen that the use of the heat pipe 100 in the embodiment of the present application can increase the CPU power by about 0.2W, which can improve some of the CPU's working performance.

[0212] In terms of the temperature difference between the hot and cold ends of the heat pipe, the heat pipe 100 using the capillary solution in the embodiment of the present application has a temperature difference of 1.4°C on the hot and cold ends of the CPU-side heat pipe 100, while the heat pipe using the full copper powder solution has a temperature difference of 3.1°C on the hot and cold ends of the CPU-side heat pipe. It can be seen that when using the heat pipe 100 in the embodiment of the present application, there is a redundancy of about 3-4°C in the temperature difference between the hot and cold ends, so it can handle greater heat dissipation requirements.

[0213] In the dual heat source test, the heat pipe 100 using the capillary solution in the embodiment of the present application has a CPU power of 59.253W and a GPU power of 49.86W, with the total power of the two added up to 109.113W. However, when the heat pipe using the all-copper powder solution was used, the CPU power was 52.341W and the GPU power was 102.181W. It can be seen that the use of the heat pipe 100 in the embodiment of the present application can increase the power of the CPU + GPU by about 7W, which can improve the working performance of the CPU + GPU.

[0214] Thus, the heat pipe 100 using the composite capillary solution in the embodiment of the present application has the advantage of a smaller temperature difference between the hot and cold ends compared to a conventional heat pipe using an all-copper powder capillary solution, making it less likely to experience dry-burning in the evaporation section 101 or liquid accumulation in the condensation section 102. It also has a greater heat dissipation power and can handle greater heat dissipation requirements. Electronic devices using the heat pipe 100 in the embodiment of the present application can significantly reduce the operating temperature of the electronic component 500, allowing the electronic component 500 to have greater power, thereby improving the operating performance of the electronic device.

[0215] As shown in Figure 5, an embodiment of the present application also provides a radiator 400, which includes a heat dissipation component 200, a heat conduction plate 300 and a heat pipe 100 provided in any of the aforementioned embodiments. The heat dissipation component 200 is sleeved on the condensation part 102 of the heat pipe 100, and the heat conduction plate 300 is fixed on the evaporation part 101 of the heat pipe 100.

[0216] The heat sink 400 in the embodiment of the present application includes the heat pipe 100 provided in any of the above embodiments. The first capillary structure 20 inside the heat pipe 100 is made of a material with a relatively high capillary pressure, and the second capillary structure 30 is made of a material with a relatively high permeability. Since the second capillary structure 30 is wrapped inside the first capillary structure 20 and not exposed in the accommodating cavity 11, the inner surface of the accommodating cavity 11 is the first capillary structure 20. Since the capillary pressure is a surface parameter, the capillary pressure in the heat pipe 100 all comes from the first capillary structure 20. In this case, driven by the relatively high capillary pressure of the first capillary structure 20, the liquid working fluid will simultaneously reflux through the first capillary structure 20 and the second capillary structure 30. The second capillary structure 30 with its low reflux resistance serves as a "high-speed channel" for the reflux of the liquid working fluid, which can quickly transfer the liquid working fluid to the evaporation portion 101. Compared to a heat pipe 100 having only the first capillary structure 20, the heat pipe 100 in the embodiment of the present application has a smaller reflux resistance, and compared to a heat pipe 100 having only the second capillary structure 30, the heat pipe 100 in the embodiment of the present application has a greater driving force. Therefore, the design of the first capillary structure 20 enveloping the second capillary structure 30 facilitates the reflux of the liquid working fluid in the heat pipe 100 in the embodiment of the present application, accelerates the liquid-gas cycle speed, and thus improves the heat transfer capacity of the heat pipe 100. It can effectively prevent dry burning in the evaporation section 101 and liquid accumulation in the condensation section 102, making it less likely for the heat pipe 100 to reach its heat transfer limit, and can effectively improve the heat dissipation power of the radiator 400.

[0217] Optionally, the heat pipe 100 and the heat conducting plate 300, and the heat dissipation assembly 200 can be fixedly connected by bonding, welding, bolting, snap-fitting, etc.

[0218] Optionally, the heat dissipation component 200 includes but is not limited to heat dissipation fins and heat dissipation grilles, which can provide a larger heat exchange area; or, the heat dissipation component 200 can also be a metal bracket of a functional component in an electronic device. For example, when the electronic device is a mobile phone, the heat dissipation component 200 can be a middle frame or a back cover, which can quickly conduct heat from the inside of the mobile phone to the outside and dissipate it into the environment.

[0219] Optionally, in order to improve the heat dissipation effect of the heat dissipation component 200, a heat dissipation fin structure, a heat dissipation convex structure, a heat dissipation wave structure, etc. can be opened on the outer surface of the heat dissipation component 200, which can increase the heat exchange area of ​​the outer surface of the heat dissipation component 200, and thus quickly dissipate the heat from the electronic component 500 to the environment; or, a fan is added to the outside of the heat dissipation component 200, and the air flow direction of the fan is facing the heat dissipation component 200, so that the heat from the electronic component 500 on the heat dissipation component 200 is quickly taken away by air cooling.

[0220] Optionally, a water cooling mechanism can be added to the heat dissipation assembly 200 to further enhance the heat dissipation effect. For example, a circulating water pump can be added. The heat dissipation assembly 200 is a hollow structure with a water inlet and a water outlet. The circulating water pump is connected to the water inlet and the water outlet through pipes to inject circulating cooling water into the heat dissipation assembly 200.

[0221] Specifically, the cooling water circulates in a closed manner in the pipeline, and the heat of the heat dissipation component 200 is taken away by the cooling water, and then dissipated into the environment through the pipeline; or, an external heat exchanger is connected through the pipeline, and the heat of the heat dissipation component 200 is taken away by the cooling water and flows into the heat exchanger, and the heat exchanger dissipates the heat through the air.

[0222] While the interface between the electronic component 500 and the heat conducting plate 300 appears to be in good contact, only a portion of the surface is in direct contact, with the remainder consisting of gaps. The gas within these gaps has a high thermal resistance (thermal resistance refers to the resistance encountered by heat along the heat flow path, reflecting the heat transfer capacity of the medium or between media) and a very low thermal conductivity, which severely hinders the transfer of heat from the electronic component 500 to the heat sink 400. Therefore, a thermally conductive medium is needed to fill these gaps to facilitate smoother and faster heat transfer.

[0223] Optionally, thermal conductive liquid gold or thermal conductive silicone grease can be applied between the heat conducting plate 300 and the electronic component 500 so that the gap is filled with a thermal conductive medium. The thermal conductive medium allows the heat sink 400 and the electronic component 500 to be in closer contact with each other, thereby achieving a better heat transfer effect and allowing the heat sink 400 to dissipate the heat generated by the electronic component 500 more efficiently.

[0224] Optionally, in order to prevent the existence of gaps between the heat pipe 100 and the heat conducting plate 300, and between the heat pipe 100 and the heat dissipation component 200, resulting in thermal resistance inside the radiator 400, a heat conducting medium can also be filled between the heat pipe 100 and the heat conducting plate 300, and between the heat pipe 100 and the heat dissipation component 200.

[0225] The heat sink 400 in the embodiment of the present application does not limit the specific type of the electronic component 500 capable of dissipating heat. For example, the electronic component 500 can be a central processing unit (CPU), a graphics processing unit (GPU), a universal flash storage (UFS), a system-in-package (SiP) component, an antenna in package (AiP), a system-on-chip (SOC) component, a double data rate (DDR) memory, a radio frequency integrated circuit (RF IC), a radio frequency power amplifier (RF PA), a power management unit (PMU), an embedded multimedia card (EMMC), etc.

[0226] Figure 25 is a schematic diagram of an electronic device provided in an embodiment of the present application.

[0227] As shown in Figure 25, an embodiment of the present application further provides an electronic device, which is a notebook computer, and a heat sink 400 is provided inside the body of the notebook computer.

[0228] In addition, the electronic device may be any one of a desktop computer, a tablet computer, a game console, a mobile phone, an electronic watch, a router, a set-top box, a television, and a modem.

[0229] Optionally, in the electronic device of the present application, in addition to applying the aforementioned radiator 400 , the position relationship of the radiator 400 in the electronic device can also be reasonably arranged to further improve the heat dissipation effect of the electronic device and improve the thermal conductivity efficiency of the radiator 400 . Specific layout design: First, temperature-sensitive electronic components 500 are best placed in the lowest temperature area, such as the bottom of the electronic device, to avoid being installed directly above the heat-generating device. Multiple devices are preferably staggered in a horizontal plane. Second, to avoid the concentration of hot spots on the substrate (such as the printed circuit board, PCB), high-power electronic components 500 should be distributed as evenly as possible on the substrate to maintain uniform and consistent substrate surface temperature performance. Third, electronic components 500 with the highest power consumption and the highest heat generation should be placed near the optimal heat dissipation position in the electronic device, such as near the fan outlet. Fourth, electronic components 500 on the same substrate should be arranged according to their heat generation and heat dissipation level as much as possible. Electronic components 500 with low heat generation or poor heat resistance should be placed upstream of the cooling airflow, while devices with high heat generation or good heat resistance, such as large-scale integrated circuits, should be placed downstream of the cooling airflow. Fifth, high-power electronic components 500 should be placed as close to the edge of the substrate as possible in the horizontal direction to shorten the heat transfer path. In the vertical direction, high-power electronic components 500 should be placed as close to the top of the substrate as possible to reduce the impact of these components on the temperature of other components during operation.

[0230] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A heat pipe, characterized in that: include: A pipe body (10) having an accommodating cavity (11) inside for sealing a working fluid; A first capillary structure (20) is attached to the inner tube surface (12) of the tube body (10); A second capillary structure (30) is wrapped inside the first capillary structure (20); The first capillary structure (20) and the second capillary structure (30) are configured such that: the capillary pressure of the first capillary structure (20) is greater than the capillary pressure of the second capillary structure (30), and the permeability of the second capillary structure (30) is greater than the permeability of the first capillary structure (20).

2. The heat pipe according to claim 1, characterized in that The first capillary structure (20) is composed of at least one of a metal powder sintered body (51), a non-metal powder sintered body (56), and a metal woven mesh (52).

3. The heat pipe according to claim 1 or 2, characterized in that: The second capillary structure (30) is composed of at least one of foamed metal (53), non-metallic fiber body (54), metal braided mesh (52), and metal braided braid (55).

4. The heat pipe according to any one of claims 1 to 3, characterized in that: Also includes: A groove capillary structure (40) is provided on the inner tube surface (12) and / or the second capillary structure (30).

5. The heat pipe according to any one of claims 1 to 4, characterized in that: The side of the second capillary structure (30) facing the inner tube surface (12) is exposed from the first capillary structure (20) and abuts against the inner tube surface (12).

6. The heat pipe according to any one of claims 1 to 5, characterized in that: The number of the second capillary structures (30) is plural, and the plurality of second capillary structures (30) are arranged at intervals along the circumference of the tube body (10).

7. The heat pipe according to any one of claims 1 to 6, characterized in that: The first capillary structure (20) has a protruding portion (21) at a location corresponding to the second capillary structure (30).

8. The heat pipe according to claim 7, characterized in that The edge of the protrusion (21) transitions smoothly with the surface of the first capillary structure (20).

9. The heat pipe according to any one of claims 1 to 8, characterized in that: The tube body (10) comprises two opposite flat tube walls (13) and two opposite arc-shaped tube walls (14).

10. The heat pipe according to claim 9, characterized in that The first capillary structure (20) and the second capillary structure (30) are arranged on any one of the two flat tube walls (13).

11. The heat pipe according to any one of claims 1 to 9, characterized in that: Along the circumference of the tube body (10), the first capillary structure (20) is arranged around the inner tube surface (12) in a circle.

12. The heat pipe according to claim 6, characterized in that The spacing distance between two adjacent second capillary structures (30) is 2-4 mm.

13. The heat pipe according to claim 7 or 8, characterized in that: The distance between the surface of the protrusion (21) and the second capillary structure (30) is greater than 0.3 mm.

14. The heat pipe according to any one of claims 1 to 13, characterized in that: The thickness of the second capillary structure (30) is 0.2-0.7 mm.

15. The heat pipe according to any one of claims 1 to 14, characterized in that: The width of the second capillary structure (30) is 2-8 mm.

16. The heat pipe according to any one of claims 1 to 15, characterized in that: The thickness of the first capillary structure (20) is 0.4-1.1 mm.

17. The heat pipe according to claim 3, characterized in that The material of the non-metallic fiber body (54) includes glass fiber or carbon fiber.

18. The heat pipe according to claim 3, characterized in that The material of the foam metal (53) includes copper or aluminum; the material of the metal braided mesh (52) includes copper or aluminum; and the material of the metal braided braid (55) includes copper or aluminum.

19. A radiator, characterized in that: The invention comprises a heat dissipation component (200), a heat conduction plate (300), and a heat pipe (100) according to any one of claims 1 to 18, wherein the heat dissipation component (200) is sleeved on a condensation portion (102) of the heat pipe (100), and the heat conduction plate (300) is fixed on an evaporation portion (101) of the heat pipe (100).

20. An electronic device, characterized in that: Comprising the heat sink (400) as claimed in claim 19.

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