Plate type 3D uniform temperature plate heat dissipation structure, preparation process and application in electronic equipment

Abstract

This invention discloses a plate-type 3D vapor chamber heat dissipation structure, manufacturing process, and application in electronic devices. It includes a first cover plate, a second cover plate, and a heat exchange unit disposed on the second cover plate. The second cover plate covers the first cover plate, forming a first cavity for medium evaporation. The heat exchange unit is a closed shell structure, with a second cavity inside for medium condensation. The second cavity is connected to the first cavity to form a flow path for medium vapor to flow from the first cavity to the second cavity. The first cavity contains a first capillary structure, and the inner wall of the second cavity contains a second capillary structure. The pore size and / or porosity of the first and second capillary structures are different. The heat exchange unit and the second cover plate are an integral structure, avoiding insufficient capillary force or obstructed return path, thereby ensuring the continuity and stability of the working fluid in the gas-liquid phase change cycle and improving heat dissipation.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology, and in particular to a plate-type 3D vapor chamber heat dissipation structure, its manufacturing process, and its application in electronic devices. Background Technology

[0002] As electronic devices rapidly evolve towards higher performance and greater integration, the heat flux density of core components such as chips and power modules is escalating dramatically. Traditional air-cooling solutions are increasingly showing their limitations in handling such high heat flux densities. Vapor chambers, as highly efficient two-phase flow heat transfer devices, utilize the evaporation and condensation cycle of the working fluid to achieve rapid heat diffusion and transfer, and have been widely used in high-performance computing, data centers, new energy vehicles, 5G communications, and other fields.

[0003] Existing vapor chambers typically consist of upper and lower cover plates forming a sealed cavity. The inner wall of the cavity has capillary structures and is filled with a working fluid. During operation, a heat source heats the evaporation end, the working fluid absorbs heat and vaporizes to form steam. The steam flows to the condensation end, releases heat, and condenses into liquid. The liquid then flows back to the evaporation end under the suction of the capillary structures, thus completing the heat transfer. However, with the continuous increase in heat flux density and the increasing complexity of application scenarios, traditional vapor chambers have gradually revealed the following problems in terms of structural design and capillary control: The evaporation and condensation chambers of traditional vapor chambers are usually located in the same plane. The condensation end often requires additional heat dissipation fins or air-cooling components for secondary heat dissipation, resulting in a large space occupied by the overall heat dissipation structure in the height direction, making it difficult to meet the requirements of thin and compact electronic devices. At the same time, the evaporation and condensation ends share the same cavity, and the steam flow path and liquid return path interfere with each other, easily causing gas-liquid entrainment, which restricts the improvement of heat transfer efficiency.

[0004] Therefore, how to construct an efficient gas-liquid circulation path within a limited space, achieve differentiated capillary structure design to balance suction force and permeability, and improve overall structural strength and reliability are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a plate-type 3D vapor chamber heat dissipation structure, its manufacturing process, and its application in electronic devices.

[0006] The technical solution adopted by this invention to solve its technical problem is: The present invention provides a plate-type 3D heat dissipation structure, manufacturing process and application in electronic devices, including a first cover plate, a second cover plate and a heat exchange unit disposed on the second cover plate, wherein the second cover plate covers the first cover plate and surrounds a first cavity for medium evaporation. The heat exchange unit is a closed shell structure. Inside the heat exchange unit, there is a second cavity for medium condensation. The second cavity is connected to the first cavity to form a flow path for medium vapor to flow from the first cavity to the second cavity. The first cavity is provided with a first capillary structure, and the inner wall of the second cavity is provided with a second capillary structure. The pore size and / or porosity of the first capillary structure and the second capillary structure are different. The heat exchange unit and the second cover plate are an integral structure.

[0007] Preferably, the first cover plate has a first recessed portion, and the first recessed portion has a second recessed portion for contacting the external heat source. A stepped or gradual transition structure is formed between the first and second recessed portions to create medium flow regions of different depths. The first cover plate, the first recessed portion, and the second recessed portion are an integral structure. The first cavity is formed by the first cover plate, the first recessed portion, the second recessed portion, and the second cover plate. The stepped or gradual transition structure realizes the construction of medium flow regions with different depth gradients at the evaporation end. By utilizing the integral structure of the first cover plate, the first recessed portion, and the second recessed portion, the contact thermal resistance caused by the assembly interface in the traditional split groove structure is eliminated, realizing the continuity and efficiency of the heat transfer path from the heat source to the working fluid. The two recessed portions can guide the internal medium flow step by step, significantly improving the pressure bearing capacity and structural reliability.

[0008] Preferably, the second cover plate is provided with a powder ring on the side near the first cover plate. The powder ring is arranged in a racetrack shape. The powder ring and the second capillary structure are integrally sintered together. The end of the powder ring away from the second cover plate abuts against the first capillary structure.

[0009] Preferably, the first capillary structure is disposed on the cavity wall of the first cavity and located on the first cover plate. The first capillary structure in the first cavity is a double-layer capillary structure formed by a composite of a metal mesh structure and a sintered powder structure. The second capillary structure is disposed on the cavity wall of the second cavity. The second capillary structure in the second cavity is a sintered metal powder structure. The pore size of the first capillary structure is smaller than that of the second capillary structure, so as to optimize the evaporation capacity and reflux capacity respectively, thereby forming a structural configuration with high capillary force at the evaporation end and high permeability at the condensation end. This technical means involves setting a metal mesh on the cavity wall of the first cavity. The double-layer capillary structure, composed of a composite structure of structural and sintered powder, with sintered metal powder structure set on the cavity wall of the second cavity, while limiting the pore size of the first capillary structure to be smaller than that of the second capillary structure, achieves the effect of constructing a composite capillary structure with high capillary suction force and low flow resistance at the evaporation end, and constructing a large-pore high-permeability reflux channel at the condensation end. This achieves the synergistic effect of enabling the evaporation end to quickly absorb liquid and suppress overheating, and enabling the condensation end to smoothly transport the condensate back to the evaporation end, effectively avoiding the heat transfer limit problem caused by the inability to balance capillary force and permeability.

[0010] Preferably, the heat exchange unit array has multiple units arranged in an array. The heat exchange units and the second cover plate form a steam flow channel. The steam flow channel is defined by the second cover plate and the inner wall of the heat exchange unit. The cross-sectional dimensions of the steam flow channel are non-uniformly distributed or locally contracted along the steam flow direction, which guides the steam to generate velocity changes and local acceleration during the flow process. This breaks the boundary layer stagnation phenomenon that easily forms in the uniform channel, enhances the convective heat transfer intensity between the steam and the channel wall, and effectively suppresses the problem of insufficient steam condensation capacity at the far end, thus achieving a significant improvement in the temperature uniformity of the entire temperature distribution plate surface.

[0011] The fabrication process of the plate-type 3D vapor chamber heat dissipation structure includes the following steps: bending and forming the second cover plate and stamping it along the width direction to form a strip support; filling the heat exchange unit and the second cover plate with capillary structure powder in a vacuum or low-pressure protective gas environment and sintering it to form an integrally formed powder ring and the second capillary structure; filling the cavity wall of the first cover plate with capillary structure powder and sintering it; welding the sintered second cover plate and the first cover plate together with silver wire soldering; injecting the medium into the formed vapor chamber heat dissipation structure and evacuating it; and finally sealing it.

[0012] Preferably, the heat exchange unit is formed by placing the bent second cover plate and the heat exchange unit in an external mold, inserting a core rod into the outer shell of the heat exchange unit, forming a gap between the core rod and the outer shell of the heat exchange unit for accommodating capillary powder, and providing a chamber for forming a powder ring in the mold. The capillary powder is filled between the copper tube and the core rod and sintered. After sintering, the core rod is removed to form an integral second capillary structure and a powder ring. The powder ring is used to guide the medium on the second capillary structure to the first cover plate.

[0013] Preferably, during the vacuuming process, the radiator structure is placed inside the external low-temperature medium, so that the medium in the first cavity is in a low-temperature state to reduce the evaporation of the medium. The radiator structure is also welded with a liquid injection pipe for injecting the medium from the outside. After vacuuming, the end of the liquid injection pipe away from the radiator is sealed. After sealing one end of the liquid injection pipe, the radiator is heated to cause the residual gas inside to be released into the liquid injection pipe. During the heating process of the radiator, the end of the liquid injection pipe close to the radiator is sealed. Then, the part of the liquid injection pipe protruding from the radiator structure is cut off and separated.

[0014] An electronic device includes a plate-type 3D vapor chamber heat dissipation structure for cooling high heat flux density electronic devices. By integrating the aforementioned plate-type 3D vapor chamber heat dissipation structure and using it to cool high heat flux density electronic devices, the electronic device achieves a three-dimensional layout of evaporation and condensation functions and enables rapid transfer of local high-temperature heat from the heat source to a large-area condensation area. This significantly improves the heat flux carrying capacity of the heat dissipation system within a limited space, effectively solving the problem of temperature rise runaway caused by excessively high local heat flux density in high-performance chips, power modules, and other electronic devices, and ensuring the thermal stability and service life of the electronic device under high-power operating conditions.

[0015] The beneficial effects of this invention are as follows: By integrating the heat exchange unit and the second cover plate into a single structure, and utilizing the communication between the first and second cavities to form a path for the medium vapor to flow directionally from the evaporation zone to the condensation zone, a complete and well-sealed circulation loop from evaporation to condensation is constructed. This effectively improves the overall structural strength, eliminates the thermal resistance and leakage risks at the joint surfaces caused by traditional split-assembly, and ensures efficient transmission of the steam working fluid. Simultaneously, by setting a first capillary structure in the first cavity and a second capillary structure on the inner wall of the second cavity, and utilizing the difference in pore size and / or porosity between the two, differentiated capillary suction force and flow resistance are formed at the evaporation and condensation ends, respectively. This achieves efficient return of the liquid working fluid from the condensation end (second cavity) to the evaporation end (first cavity) by utilizing the difference in pore size and / or porosity, avoiding insufficient capillary force or obstructed return path, thereby ensuring the continuity and stability of the working fluid in the gas-liquid phase change cycle and improving heat dissipation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. The accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is one of the structural schematic diagrams of the plate-type 3D heat dissipation structure of the present invention; Figure 2 This is the second schematic diagram of the heat dissipation structure of the plate-type 3D heat dissipation plate of the present invention; Figure 3 This is an exploded view of the heat dissipation structure of the plate-type 3D heat dissipation plate of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the first cover plate in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of the first cover plate in Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the cross-sectional structure of the plate-type 3D heat dissipation structure of the present invention.

[0019] The reference numerals in the figures include: 1. First cover plate; 2. Second cover plate; 3. Heat exchange unit; 4. First capillary structure; 5. Second capillary structure; 6. Powder ring; 7. Copper column; 10. First cavity; 11. First recessed part; 12. Second recessed part; 31. Second cavity. Detailed Implementation

[0020] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0021] In the description of this application, terms such as "first" and "second" are used only to distinguish different objects, not to describe a specific order. Furthermore, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, and c can be single or multiple.

[0022] The terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0023] In this application, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary," "for example," or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0024] It is understood that in this application, "when," "if," and "if" all refer to the device making a corresponding action under certain objective circumstances, and are not time-limited, nor do they require the device to make a judgment action when it is implemented, nor do they imply any other limitations.

[0025] In this application, the use of singular designations for elements is intended to represent "one or more" rather than "one and only one," unless otherwise specified.

[0026] It is understood that in the embodiments of this application, "B corresponding to A" means that there is a correspondence between A and B, and B can be determined based on A. Determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0027] Example 1 Reference Figures 1 to 6 The plate-type 3D heat dissipation structure includes: a first cover plate 1, a second cover plate 2 and a heat exchange unit 3 disposed on the second cover plate 2. The second cover plate 2 covers the first cover plate 1 and surrounds a first cavity 10 for medium evaporation. The heat exchange unit 3 is a closed shell structure. The heat exchange unit 3 has a second cavity 31 for medium condensation inside. The second cavity 31 is connected to the first cavity 10 to form a flow path for medium vapor to flow from the first cavity 10 to the second cavity 31. The first cavity 10 has a first capillary structure 4, and the inner wall of the second cavity 31 has a second capillary structure 5. The pore size and / or porosity of the first capillary structure 4 and the second capillary structure 5 are different. The heat exchange unit 3 and the second cover plate 2 are an integral structure. The integral structure here refers to the metal shell being an integral structure, and the capillary structure on the metal shell is also an integral structure.

[0028] With the above-described structural configuration, in use, this technical solution integrates the heat exchange unit 3 and the second cover plate 2 into a single structure. The communication between the first cavity 10 and the second cavity 31 creates a path for the medium vapor to flow directionally from the evaporation zone to the condensation zone, constructing a complete and well-sealed circulation loop from evaporation to condensation. This effectively enhances the overall structural strength, eliminates the thermal resistance and leakage risks associated with traditional split-assembly, and ensures efficient vapor transport. Simultaneously, by setting a first capillary structure 4 within the first cavity 10 and a second capillary structure 5 on the inner wall of the second cavity 31, and utilizing the difference in pore size and / or porosity, differentiated capillary suction force and flow resistance are generated at the evaporation and condensation ends, respectively. This allows the liquid working fluid to efficiently flow back from the condensation end (second cavity 31) to the evaporation end (first cavity 10) using the difference in pore size and / or porosity, avoiding insufficient capillary force or obstructed return path. This ensures the continuity and stability of the working fluid in the gas-liquid phase change cycle and improves heat dissipation.

[0029] The first cover plate 1 is also provided with mounting holes for external screws or bolts to pass through and stop at the outside. The first cover plate 1 is also provided with a third recessed part for connecting the first cavity 10 with the outside and closing after the medium is injected. In this technical solution, the second cover plate 2 can also be provided with a capillary structure in contact with the second capillary structure 5, that is, the second cover plate 2 is bent and sintered integrally with the capillary structure. In this technical solution, the sintering temperature is 980 degrees Celsius and held at that temperature for two hours. Of course, the selectable temperature is 800-1000°C, and sintering is carried out in a hydrogen or hydrogen-nitrogen mixed atmosphere. The final heat dissipation structure can be provided with a metal plating layer on the surface. The thickness of the capillary structure is set to 1mm. When the heat dissipation structure is completed, a sealing test is required. The sealing test method is to put the heat dissipation structure into a helium leak detection device for testing.

[0030] The integrated structure in this technical solution refers to an integral structure formed by integral processing or non-detachable connection.

[0031] Specifically, the first cover plate 1 is provided with a first recessed portion 11, and the first recessed portion 11 is provided with a second recessed portion 12 for contacting the external heat source. A stepped or gradual transition structure is formed between the first recessed portion 11 and the second recessed portion 12 to form medium flow areas of different depths. The first cover plate 1, the first recessed portion 11 and the second recessed portion 12 are an integral structure. The first cavity 10 is formed by the first cover plate 1, the first recessed portion 11, the second recessed portion 12 and the second cover plate 2. The stepped or gradual transition structure realizes the construction of medium flow areas with different depth gradients at the evaporation end. By utilizing the integral structure of the first cover plate 1, the first recessed portion 11 and the second recessed portion 12, the contact thermal resistance caused by the assembly interface of the traditional split groove structure is eliminated, realizing the continuity and efficiency of the heat transfer path from the heat source to the working fluid. The two recessed portions can guide the internal medium flow step by step, which significantly improves the pressure bearing capacity and structural reliability.

[0032] Specifically, the second cover plate 2 is provided with a powder ring 6 on the side near the first cover plate 1. The powder ring 6 is arranged in a racetrack shape. The powder ring 6 and the second capillary structure 5 are integrally sintered together. The end of the powder ring 6 away from the second cover plate 2 abuts against the first capillary structure 4.

[0033] The end of the powder ring 6 away from the second cover plate 2 is in close contact with the first capillary structure 4 by sintering or brazing to ensure the connectivity of the pore structure.

[0034] The powder ring 6 has through holes on its peripheral wall, which are used to connect the second cavity 31 with the first cavity 10. The racetrack-shaped structure of the powder ring 6 has rounded transitions at the corners to facilitate the demolding of the core rod after sintering. Optionally, the core rod can be made of a soluble material (such as an aluminum core).

[0035] The heat exchange unit 3 can be a columnar, sheet-like, mesh-like, or topology-optimized structure. The inner or outer wall of the heat exchange unit 3 is provided with microstructure units to enhance the heat exchange area. The microstructure units include at least one of microribs, microprotrusions, microgrooves, or micropores, which can significantly expand the effective heat exchange area on the condensing side within a limited space, thereby significantly improving the heat exchange efficiency between the steam and the shell, enabling the condensed liquid working fluid to flow back quickly, and avoiding local drying caused by insufficient condensation capacity.

[0036] The columnar shape includes at least cylindrical, triangular, and quadrangular prisms. After the 3D heat dissipation plate structure is manufactured, heat dissipation fins are also required on the outside of the heat exchange unit 3. The heat dissipation fins can be designed using existing technologies. The specific structure is adjusted according to the shape of the heat exchange unit 3. Since the heat dissipation fins are existing conventional technology, they will not be described in detail here.

[0037] Specifically, the first capillary structure 4 is disposed on the cavity wall of the first cavity 10 and located on the first cover plate 1. The first capillary structure 4 in the first cavity 10 is a double-layer capillary structure formed by a composite metal mesh structure and a sintered powder structure. The second capillary structure 5 is disposed on the cavity wall of the second cavity 31. The second capillary structure 5 in the second cavity 31 is a sintered metal powder structure. The pore size of the first capillary structure 4 is smaller than that of the second capillary structure 5 to optimize the evaporation capacity and reflux capacity respectively, thereby forming a structural configuration with high capillary force at the evaporation end and high permeability at the condensation end. This technical means utilizes the cavity wall of the first cavity 10 The upper part is equipped with a double-layer capillary structure composed of a metal mesh structure and a sintered powder structure, and a sintered metal powder structure is set on the cavity wall of the second cavity 31. At the same time, the pore size of the first capillary structure 4 is limited to be smaller than that of the second capillary structure 5. This achieves the effect of building a composite capillary structure with high capillary suction force and low flow resistance at the evaporation end and building a large-pore high-permeability reflux channel at the condensation end. This achieves the synergistic effect of the evaporation end being able to quickly absorb liquid and suppress overheating, and the condensation end being able to smoothly transport the condensate back to the evaporation end. This effectively avoids the heat transfer limit problem caused by the inability to balance capillary force and permeability.

[0038] The first capillary structure 4 and the second capillary structure 5 form a capillary connection path, that is, they can achieve capillary transmission through mutual contact.

[0039] Specifically, the heat exchange unit 3 array has multiple units arranged in an array. The heat exchange unit 3 and the second cover plate 2 form a steam flow channel. The steam flow channel is defined by the second cover plate and the inner wall of the heat exchange unit. The cross-sectional dimensions of the steam flow channel are non-uniformly distributed or locally contracted along the steam flow direction, which plays a role in guiding the steam to generate velocity changes and local acceleration during the flow process. This breaks the boundary layer stagnation phenomenon that is easily formed in the uniform channel, enhances the convective heat transfer intensity between the steam and the channel wall, and effectively suppresses the problem of insufficient steam condensation capacity at the far end, thus achieving a significant improvement in the temperature uniformity of the entire temperature distribution plate surface.

[0040] The non-uniform distribution or local contraction distribution refers to the fact that the cross-sectional size of the steam flow channel gradually decreases along the steam flow direction to compensate for the reduction in steam mass flow rate, maintain the flow velocity at the far end, and ensure that the condensation capacity of each heat exchange unit 3 is balanced.

[0041] In this technical solution, the heat exchange unit 3 is formed by bending the second cover plate 2. The heat exchange unit 3 is stamped with a strip support member along the width direction of the second cover plate 2. The strip support member is also provided with a silver-copper solder layer for welding after the second cover plate 2 is bent. The silver-copper solder layer is used to weld the heat exchange unit 3 and also to prevent the solder from reacting with water, that is, to prevent it from reacting with the cooling medium. The welding method is argon arc welding or laser welding.

[0042] The thickness of the strip support is smaller than that of the heat exchange unit 3. The strip support and the heat exchange unit 3 are integrally formed. Preferably, the strip support may also have holes arranged along the length of the strip support.

[0043] The spacing between two adjacent strip supports is not equal to the spacing between two adjacent heat exchange units 3. Specifically, the spacing between two adjacent strip supports is greater than the spacing between two adjacent heat exchange units 3, in order to increase the airflow velocity. The strip supports and heat exchange units 3 have an arc-shaped transition.

[0044] A temperature drop component can be installed on two strip support members on a heat exchange unit 3. The temperature drop component can be installed on one of the strip support members on a heat exchange unit 3 to form a temperature difference, or it can be installed on both strip support members on a heat exchange unit 3 to cool down. The temperature drop component can use water cooling or air cooling to cool down the strip support members. When the temperature drop component uses air cooling to cool down the strip support members, the strip support members can be provided with through grooves along the length direction.

[0045] The fabrication process of the plate-type 3D heat dissipation structure includes the following steps: bending the second cover plate 2 and stamping it along the width direction of the second cover plate 2 to form a strip support; filling the heat exchange unit 3 and the second cover plate 2 with capillary structure powder under vacuum or low-pressure protective gas environment and sintering it to form an integrally formed powder ring 6 and second capillary structure 5; filling the cavity wall of the first cover plate 1 with capillary structure powder and sintering it; welding the sintered second cover plate 2 and the first cover plate 1 together with silver wire soldering; injecting the medium into the formed heat dissipation structure and evacuating it; and finally sealing it.

[0046] Specifically, the formation of the heat exchange unit 3 includes placing the bent second cover plate 2 and the heat exchange unit 3 in an external mold, inserting a core rod into the outer shell of the heat exchange unit 3, forming a gap between the core rod and the outer shell of the heat exchange unit 3 for accommodating capillary structure powder, and providing a chamber for forming a powder ring 6 in the mold. The process involves filling the space between the copper tube and the core rod with capillary structure powder and sintering it. After sintering, the core rod is removed to form an integral second capillary structure 5 and powder ring 6. The powder ring 6 is used to guide the medium on the second capillary structure 5 to the first cover plate 1.

[0047] Specifically, during the vacuuming process, the radiator structure is placed in the external low-temperature medium to keep the medium in the first chamber 10 at a low temperature to reduce evaporation. The radiator structure is also welded with a liquid injection pipe for injecting external medium. After vacuuming, the end of the liquid injection pipe away from the radiator is sealed. After sealing one end of the liquid injection pipe, the radiator is heated to cause the residual gas inside to precipitate into the liquid injection pipe. During the heating process of the radiator, the end of the liquid injection pipe close to the radiator is sealed. Then, the part of the liquid injection pipe protruding from the radiator structure is cut off and separated.

[0048] In this technical solution, a final seal (such as fusion welding) should be performed near the radiator (i.e., at the injection channel), and then the injection tube should be cut off and removed.

[0049] The first cover plate 1 is also provided with an installation area for unfilled capillary structure powder. The installation area for unfilled capillary structure powder is used to set up a support member. The two ends of the support member in the length direction are respectively used to abut against the first cover plate 1 and the second cover plate 2.

[0050] The area on the first cover plate 1 used for filling capillary structure powder is sintered to form the first capillary structure 4. In this technical solution, the capillary structure powder is 100-150 mesh copper powder.

[0051] The first cover plate 1 and the second cover plate 2 are formed by silver wire welding, which is carried out under heating and pressure conditions.

[0052] An electronic device includes a plate-type 3D vapor chamber heat dissipation structure for cooling high heat flux density electronic devices. By integrating the aforementioned plate-type 3D vapor chamber heat dissipation structure and using it to cool high heat flux density electronic devices, the electronic device achieves a three-dimensional layout of evaporation and condensation functions and enables rapid transfer of local high-temperature heat from the heat source to a large-area condensation area. This significantly improves the heat flux carrying capacity of the heat dissipation system within a limited space, effectively solving the problem of temperature rise runaway caused by excessively high local heat flux density in high-performance chips, power modules, and other electronic devices, and ensuring the thermal stability and service life of the electronic device under high-power operating conditions.

[0053] A copper pillar 7 may also be provided between the first cover plate 1 and the second cover plate 2. The copper pillar 7 forms an integral structure with the first cover plate 1 and the second cover plate 2 through a diffusion welding device. In this technical solution, the two capillary structures form at least a continuous capillary channel or a transition layer structure at the interface.

[0054] Example 2 The difference between Embodiment 2 and Embodiment 1 is that: the first cover plate 1 is provided with a first recessed portion 11, and the first recessed portion 11 is provided with a second recessed portion 12 for contacting an external heat source. A stepped or gradual transition structure is formed between the first recessed portion 11 and the second recessed portion 12 to form medium flow areas of different depths; the first cover plate 1, the first recessed portion 11 and the second recessed portion 12 are an integral structure, and the first cavity 10 is formed by the first cover plate 1, the first recessed portion 11, the second recessed portion 12 and the second cover plate 2. The first recessed portion 11 is recessed from one side of the first cover plate 1 along the thickness direction of the first cover plate 1, and the second recessed portion 12 is recessed from the end of the first recessed portion 11 away from the first cover plate 1 and towards the first cover plate 1. That is, the recessed directions of the first recessed portion 11 and the second recessed portion 12 are opposite. As a result, a thinner liquid film thickness is formed at the second recessed portion 12 near the external heat source, thereby effectively reducing thermal resistance and enhancing local boiling heat transfer.

[0055] The protruding dimension of the first recessed portion 11 is greater than the protruding dimension of the second recessed portion 12. The protruding dimension is the distance dimension protruding in the direction perpendicular to the first cover plate 1. That is, the second recessed portion 12 has a reverse protruding structure relative to the first recessed portion 11, and the cavity depth corresponding to the second recessed portion 12 is less than the cavity depth corresponding to the first recessed portion 11.

[0056] The first recessed portion 11 and the second recessed portion 12 form a stepped portion, and a capillary mesh is provided on the stepped portion. The two ends of the capillary mesh also act on the capillary structure on the first recessed portion 11 and the second recessed portion 12 or the first recessed portion 11 and the second recessed portion 12, so as to guide the medium retained on the first recessed portion 11 to the second recessed portion 12.

[0057] One end of the capillary mesh is fixed to the capillary structure on the bottom or side wall of the first recess 11, and the other end extends and is fixed to the capillary structure on the outer wall of the second recess 12, so that the capillary mesh spans both sides of the stepped portion, so as to use the capillary suction force to continuously guide the medium remaining in the first recess 11 to the second recess 12.

[0058] The main innovation of this embodiment lies in the fact that the first recessed portion 11 and the second recessed portion 12 adopt a recessed and raised structure in opposite directions, so that the corresponding area of ​​the second recessed portion 12 forms a shallower cavity depth, which plays a role in constructing a thin liquid film evaporation interface in the heat source contact area, thereby significantly reducing the heat transfer resistance in this area, enhancing the local boiling heat exchange efficiency, and realizing rapid heat absorption under high heat flux density. At the same time, by setting a capillary mesh in the stepped portion, and having the two ends of the capillary mesh act on the first recessed portion 11 and the second recessed portion 12 respectively, the medium retained in the deeper first recessed portion 11 is actively transported to the shallow cavity area of ​​the second recessed portion 12 by using capillary suction force. Thus, on the basis of thin liquid film enhanced boiling, a continuous and stable liquid supply guarantee is achieved, effectively avoiding the problem of local drying in the shallow cavity area due to excessively fast evaporation rate, so that the heat spreader can still maintain stable operation when subjected to concentrated heat flux impact.

[0059] In practical operation, the first cover plate 1 with the opposite recessed and raised structures can still function in embedded chip packaging: the chip is directly embedded in the second recessed portion 12, and the back of the chip and the bottom wall of the second recessed portion 12 form a close-range heat conduction; multi-chip module: multiple heating elements correspond to multiple recesses respectively, achieving independent enhanced heat dissipation; high voltage isolation scenario: when the heating element needs to maintain a certain distance from the metal shell, the recess is filled with insulating thermally conductive material, and the raised structure can be designed to meet the creepage distance requirements; flexible bonding scenario: when the surface of the heating element is uneven, the recess is filled with thermally conductive gel, and good contact is achieved through the deformation of the gel; and in the above scenarios, the effect achieved by the structure in Embodiment 1 is equal to or better than that achieved by the structure in Embodiment 1.

[0060] Embodiment 2 of this application can be implemented alone or in combination with Embodiment 1 described above, and this application does not impose any restrictions.

[0061] Example 3 The difference between Embodiment 3 and Embodiments 2 and 1 is that: the first cover plate 1 is provided with a first recessed portion 11, and the first recessed portion 11 is provided with a second recessed portion 12 for contacting an external heat source. A stepped or gradual transition structure is formed between the first recessed portion 11 and the second recessed portion 12 to form medium flow areas of different depths; the first cover plate 1, the first recessed portion 11 and the second recessed portion 12 are an integral structure, and the first cavity 10 is formed by the first cover plate 1, the first recessed portion 11, the second recessed portion 12 and the second cover plate 2. The first recessed portion 11 is recessed from one side of the first cover plate 1 along the thickness direction of the first cover plate 1, and the second recessed portion 12 is recessed from the end of the first recessed portion 11 away from the first cover plate 1 and towards the first cover plate 1. That is, the recessed directions of the first recessed portion 11 and the second recessed portion 12 are opposite. As a result, a thinner liquid film thickness is formed at the second recessed portion 12 near the external heat source, thereby effectively reducing thermal resistance and enhancing local boiling heat transfer.

[0062] The protruding dimension of the first recessed portion 11 is greater than the protruding dimension of the second recessed portion 12. The protruding dimension is the distance dimension protruding in the direction perpendicular to the first cover plate 1. That is, the second recessed portion 12 has a reverse protruding structure relative to the first recessed portion 11, and the cavity depth corresponding to the second recessed portion 12 is less than the cavity depth corresponding to the first recessed portion 11.

[0063] The first recessed portion 11 and the second recessed portion 12 form a stepped portion, and a capillary mesh is provided on the stepped portion. The first recessed portion 11 and the second recessed portion 12 are respectively provided with a second capillary structure 5 and a first capillary structure 4. The pore size of the first capillary structure 4 is smaller than the pore size of the second capillary structure 5. The first capillary structure 4 and the second capillary structure 5 are connected to each other at the stepped portion to guide the medium stored in the first recessed portion 11 to the second recessed portion 12.

[0064] Embodiment 3 of this application can be implemented alone or in combination with the aforementioned Embodiments 1 and 2. This application does not impose any restrictions.

[0065] Example 4 The difference between Embodiment 4 and Embodiments 3, 2 and 1 is that: the first cover plate 1 is provided with a first recessed portion 11, and the first recessed portion 11 is provided with a second recessed portion 12 for contacting an external heat source. A stepped or gradual transition structure is formed between the first recessed portion 11 and the second recessed portion 12 to form medium flow areas of different depths; the first cover plate 1, the first recessed portion 11 and the second recessed portion 12 are an integral structure, and the first cavity 10 is formed by the first cover plate 1, the first recessed portion 11, the second recessed portion 12 and the second cover plate 2. The first recessed portion 11 is recessed from one side of the first cover plate 1 along the thickness direction of the first cover plate 1, and the second recessed portion 12 is recessed from one end of the first recessed portion 11 away from the first cover plate 1 in the direction away from the first cover plate 1, that is, the first recessed portion 11 and the second recessed portion 12 have the same recessed direction; thereby forming a thicker liquid film at the second recessed portion 12 near the external heat source.

[0066] The first recessed portion 11 and the second recessed portion 12 form a stepped portion, and a capillary mesh is provided on the stepped portion. The two ends of the capillary mesh also act on the first recessed portion 11 and the second recessed portion 12 to guide the medium stored in the second recessed portion 12 to the first recessed portion 11, so as to reduce the liquid thickness at the second recessed portion 12.

[0067] One end of the capillary mesh is fixed to the bottom wall or side wall of the first recess 11, and the other end extends and is fixed to the outer wall of the second recess 12, so that the capillary mesh spans both sides of the stepped portion, so as to use capillary suction force to continuously guide the medium remaining in the second recess 12 to the first recess 11.

[0068] Embodiment 4 of this application can be implemented alone or in combination with the aforementioned Embodiments 1, 2 and 3. This application does not impose any restrictions.

[0069] The experimental data (comparison of heat dissipation performance at high heat flux density) for this technical solution are shown in the table below: The experimental data (resistance to localized drying) of this technical solution are shown in the table below: The experimental data (application scenario adaptability) of this technical solution are shown in the table below: The above descriptions provide one or more embodiments in conjunction with specific details, but do not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A plate-type 3D vapor chamber heat dissipation structure, characterized in that, include: A first cover plate (1), a second cover plate (2) and a heat exchange unit (3) provided on the second cover plate (2), wherein the second cover plate (2) covers the first cover plate (1) and surrounds a first cavity (10) for medium evaporation. The heat exchange unit (3) is a closed shell structure. The heat exchange unit (3) is provided with a second cavity (31) for medium condensation. The second cavity (31) is connected to the first cavity (10) to form a flow path for medium vapor to flow from the first cavity (10) to the second cavity (31). The first cavity (10) is provided with a first capillary structure (4), and the second cavity (31) is provided with a second capillary structure (5). The pore size and / or porosity of the first capillary structure (4) and the second capillary structure (5) are different. The heat exchange unit (3) and the second cover plate (2) are an integral structure.

2. The plate-type 3D heat dissipation structure according to claim 1, characterized in that: The first cover plate (1) is provided with a first recessed part (11), and the first recessed part (11) is provided with a second recessed part (12) for contacting external heat sources. A stepped or gradual transition structure is formed between the first recessed part (11) and the second recessed part (12) to form medium flow areas of different depths. The first cover plate (1), the first recessed part (11) and the second recessed part (12) are an integral structure, and the first cavity (10) is formed by the first cover plate (1), the first recessed part (11), the second recessed part (12) and the second cover plate (2).

3. The plate-type 3D heat dissipation structure according to claim 1, characterized in that: The second cover plate (2) is also provided with a powder ring (6) on the side close to the first cover plate (1). The powder ring (6) is arranged in a racetrack shape. The powder ring (6) and the second capillary structure (5) are integrally sintered. The end of the powder ring (6) away from the second cover plate (2) abuts against the first capillary structure (4).

4. The plate-type 3D heat dissipation structure according to claim 1 or 2, characterized in that: The first capillary structure (4) is located on the cavity wall of the first cavity (10) and on the first cover plate (1). The first capillary structure (4) in the first cavity (10) is a double-layer capillary structure formed by the combination of metal mesh structure and sintered powder structure. The second capillary structure (5) is located on the cavity wall of the second cavity (31). The second capillary structure (5) in the second cavity (31) is a sintered metal powder structure. The pore size of the first capillary structure (4) is smaller than that of the second capillary structure (5) to form a structural configuration with high capillary force at the evaporation end and high permeability at the condensation end.

5. The plate-type 3D heat dissipation structure according to claim 1 or 3, characterized in that: The heat exchange unit (3) array is provided with multiple units and is distributed in an array. The heat exchange unit (3) and the second cover plate (2) form a steam flow channel. The steam flow channel is defined by the second cover plate and the inner wall of the heat exchange unit. The cross-sectional dimensions of the steam flow channel are non-uniformly distributed or locally contracted along the steam flow direction.

6. The plate-type 3D heat dissipation structure according to claim 1, characterized in that: The heat exchange unit (3) is formed by bending the second cover plate (2). The heat exchange unit (3) is stamped with a strip support member along the width direction of the second cover plate (2). The strip support member is also provided with a silver-copper solder layer for welding after the second cover plate (2) is bent.

7. The fabrication process of a plate-type 3D heat dissipation structure, characterized in that, Includes the following steps: The second cover plate (2) is bent and formed, and a strip support is formed by stamping along the width direction of the second cover plate (2). Under vacuum or low-pressure protective gas environment, capillary structure powder is filled into the heat exchange unit (3) and the second cover plate (2) and sintered to form an integral powder ring (6) and the second capillary structure (5). The capillary structure powder is filled into the cavity wall of the first cover plate (1) and sintered. The sintered second cover plate (2) and the first cover plate (1) are welded together by silver wire welding. The heat dissipation structure of the heat exchange plate after forming is injected with medium and vacuumed. Finally, the opening is sealed.

8. The fabrication process of the plate-type 3D heat dissipation structure according to claim 7, characterized in that: The formation of the heat exchange unit (3) includes placing the bent second cover plate (2) and the heat exchange unit (3) in an external mold, inserting a core rod into the outer shell of the heat exchange unit (3), forming a gap between the core rod and the outer shell of the heat exchange unit (3) for accommodating capillary powder, and providing a chamber for forming a powder ring (6) in the mold. The process involves filling the space between the copper tube and the core rod with capillary powder and sintering it. After sintering, the core rod is removed to form an integral second capillary structure (5) and a powder ring (6). The powder ring (6) is used to guide the medium on the second capillary structure (5) to the first cover plate (1).

9. The fabrication process of the plate-type 3D heat dissipation structure according to claim 7, characterized in that: During the vacuuming process, the radiator structure is placed in the external low-temperature medium, so that the medium in the first cavity (10) is in a low-temperature state to reduce the evaporation of the medium. The radiator structure is also welded with a liquid injection pipe for injecting the external medium. After vacuuming, the end of the liquid injection pipe away from the radiator is sealed. After sealing one end of the liquid injection pipe, the radiator is heated to promote the release of residual gas into the liquid injection pipe. During the heating process of the radiator, the end of the liquid injection pipe close to the radiator is sealed. Then, the part of the liquid injection pipe protruding from the radiator structure is cut off and separated.

10. An electronic device, characterized in that: The invention includes a plate-type 3D vapor chamber heat dissipation structure as described in any one of claims 1-6, used for heat dissipation of high heat flux density electronic devices.

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