A flat plate heat dissipation optimization method and heat dissipation structure based on gradient magnetic field thermomagnetic regulation

Abstract

The application discloses a flat plate heat dissipation optimization method and heat dissipation structure based on gradient magnetic field thermomagnetic regulation and control, and belongs to the technical field of thermal management and electronic heat dissipation. The application is based on the principle of thermomagnetic convection, and at least one permanent magnet is arranged on one side or both sides of a flat plate to construct a non-uniform gradient magnetic field. By adjusting the number, spatial arrangement mode and magnet parameters of the magnet, the coupling relationship between the magnetic volume force and the thermal buoyancy force of the magnetic medium can be actively changed, so that the flow field structure in the thermal boundary layer of the flat plate can be accurately regulated and controlled. The application can not only strengthen natural convection, optimize temperature distribution and heat exchange intensity in the gravity environment, but also replace gravity to become the dominant mechanism for driving convective heat dissipation in the microgravity environment, so that the directional improvement of heat dissipation efficiency is realized. The heat dissipation structure has no moving parts, is quiet and reliable in operation, and is especially suitable for efficient thermal management of high-power-density electronic devices such as 5G communication chips and high-performance processors.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for electronic devices, and in particular to a method and structure for optimizing heat dissipation of a flat plate based on gradient magnetic field thermomagnetic control. Background Technology

[0002] With the rapid development of 5G communication, artificial intelligence, high-performance computing, and aerospace electronics, the power density of electronic devices continues to rise, leading to a sharp increase in their heat flux density. Heat dissipation has become a core bottleneck restricting system performance, reliability, and lifespan. Traditional heat dissipation solutions, such as forced air cooling (using fans) or liquid cooling, while improving heat dissipation capacity, generally have inherent drawbacks such as easy wear of moving parts, vibration and noise generation, complex structure, high energy consumption, and poor adaptability to special environments (such as high-altitude environments and microgravity in space).

[0003] Flat plates (or fins) are widely used in various heat sinks as a basic and efficient extended heat dissipation surface. Their heat dissipation performance mainly relies on natural convection, a process driven by thermal buoyancy caused by temperature differences in a gravitational field. However, natural convection has limited heat transfer capacity and is completely passive, unable to actively adjust according to changes in heat load, making it difficult to meet the precise thermal management requirements of modern high-fluctuation, high-reliability loads.

[0004] In recent years, magnetic field-assisted heat transfer technology has attracted much attention due to its advantages such as being contactless, having no moving parts, and being highly controllable. However, existing research mainly focuses on using electromagnets or superconducting magnets to control the flow and heat exchange of conductive fluids such as liquid metals and magnetic nanofluids. Research on static magnetic fields is limited, and there is a lack of practical engineering applications. Electromagnetic coils have inherent limitations in practical applications, such as heat loss, low energy efficiency, dependence on external power sources, and insufficient thermal stability; superconducting magnets, on the other hand, are difficult to widely apply in industrial production due to their high material costs and complex cryogenic cooling systems. In contrast, permanent magnets (such as neodymium iron boron and ferrite) have outstanding characteristics such as long lifespan, strong magnetism, high magnetic energy product, high temperature resistance, resistance to demagnetization, vibration resistance, and highly stable gradient magnetic fields, providing new possibilities for the practical application of magnetic field-assisted heat transfer.

[0005] Although physics has clearly established that magnetic media are subject to magnetic volume forces in strong gradient magnetic fields, how to transform this principle into an active thermal management method that is structurally simple, has well-defined parameters, is engineeringable, and applicable to conventional electronic heat dissipation scenarios, especially for open-planar heat dissipation structures, remains a key issue that urgently needs to be explored and resolved in this field.

[0006] Therefore, there is an urgent need to develop a new method and structure that can overcome the shortcomings of traditional heat dissipation methods and achieve active, silent, and efficient control of the heat dissipation performance of flat panels. Summary of the Invention

[0007] Traditional flat-panel cooling relies primarily on natural convection for heat dissipation, but its heat transfer efficiency is limited by the strength of the gravitational field, making it difficult to meet the growing heat dissipation demands of high-power-density electronic devices. While active cooling methods such as fans can improve heat transfer intensity, they are accompanied by problems such as noise, vibration, energy consumption, and reliability, and cannot be applied to scenarios or microgravity environments with stringent requirements for quiet operation and reliability. Existing research on magnetic field-assisted heat transfer mainly focuses on specific magnetic fluids, and practical control schemes for general magnetic media, especially active thermal management methods that combine high efficiency and ease of engineering implementation for open flat-panel structures, are still in urgent need of development.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] A heat dissipation structure based on gradient magnetic field control, characterized in that it comprises:

[0010] A heat sink substrate having a cavity structure having an internal space for accommodating a magnetic medium;

[0011] At least one permanent magnet module is arranged on the heat dissipation surface of the heat sink substrate and / or the inner wall surface of the cavity structure. The permanent magnet module and the heat sink substrate can be fixed or movable relative to each other.

[0012] The permanent magnet modules are arranged in a preset layout to form an adjustable non-uniform gradient magnetic field, which is used to enhance heat transfer, suppress heat transfer, or directionally control heat transfer on the heat sink surface and inside the cavity.

[0013] Furthermore, the preset layout includes at least one of the following parameters: the number of permanent magnet modules, the vertical distance from the bottom of the heat sink substrate, the horizontal distance from the surface of the heat sink substrate, the magnetic pole direction, the magnet size, and the residual magnetic induction intensity.

[0014] The magnetic pole direction includes axial magnetization perpendicular to the heat sink surface, tangential magnetization parallel to the heat sink surface, or a combination of both.

[0015] Furthermore, two permanent magnet modules are arranged sequentially on one or both sides of the heat sink substrate. By adjusting the relative vertical distance between the two permanent magnet modules and the bottom of the heat sink substrate, as well as the relative horizontal distance between the two permanent magnet modules and the surface of the heat sink substrate, and configuring their magnetic pole directions to be in the same or opposite directions, the heat dissipation performance is optimized.

[0016] Furthermore, when the magnetic pole directions of the two permanent magnet modules are configured to be in the same or opposite directions, a coupled gradient magnetic field is formed to optimize the overall temperature uniformity of the heat dissipation surface and to directionally enhance the heat dissipation performance of the target area.

[0017] Furthermore, the heat sink substrate and the cavity structure form an integral configuration, including an integrally molded structure, a multi-layer stacked structure, a split assembly structure, or an embedded composite structure; the cavity structure is an open cavity or a flow cavity with fluid inlets and outlets.

[0018] Furthermore, it also includes fin structures, microchannel structures, porous dielectric layers or phase change material layers disposed on the heat sink substrate or cavity structure, for synergistic enhancement or regulation of heat dissipation performance.

[0019] A method for optimizing heat dissipation of a flat plate based on gradient magnetic field thermomagnetic control, used with the above-mentioned heat dissipation structure, includes the following steps:

[0020] (1) A heat sink substrate is provided, the heat sink substrate having a cavity structure having an internal space for accommodating a magnetic medium;

[0021] (2) At least one permanent magnet module is arranged on the heat dissipation surface of the heat sink substrate and / or the inner wall surface of the cavity structure. The permanent magnet module and the heat sink substrate can be fixed or movable relative to each other to form a non-uniform gradient magnetic field.

[0022] (3) By adjusting at least one of the following parameters: the number of permanent magnet modules, the vertical distance between the permanent magnet module and the bottom of the heat sink substrate, the horizontal distance between the permanent magnet module and the surface of the heat sink substrate, the magnetic pole direction, the magnet size and the residual magnetic induction intensity, the magnetic volume force distribution of the magnetic medium around the heat sink substrate and its coupling relationship with the thermal buoyancy force are changed.

[0023] (4) Based on the adjustment in step (3), the gradient magnetic field and the temperature field work together to optimize the temperature field and flow field on the surface of the heat sink substrate, thereby achieving active control over the average temperature, the maximum temperature and the overall heat transfer intensity.

[0024] Furthermore, the active control includes:

[0025] By constructing magnetic field gradients that are enhanced or weakened along the direction of fluid flow, magnetization forces pointing in the direction of mainstream flow or magnetic resistance opposite to the direction of mainstream flow are generated, thereby enhancing heat transfer to eliminate hot spots or suppressing heat transfer to form a thermal resistance barrier.

[0026] Alternatively, by constructing a transverse magnetic field gradient perpendicular to the mainstream direction, a transverse force perpendicular to the flow direction can be generated, guiding the fluid to deflect and transport along a preset path, thereby achieving directional heat transfer control.

[0027] Alternatively, by constructing a periodic or alternating magnetic field distribution, fluid oscillations or vortex flows can be induced, thereby enhancing fluid mixing and heat exchange efficiency.

[0028] Alternatively, by combining the above methods, the temperature field on the heat sink surface and inside the cavity can be made uniform or a specific temperature distribution can be achieved.

[0029] Furthermore, the method is applied in high heat flux density thermal management of power semiconductor devices, LED lighting equipment, 5G communication base station equipment, data center servers, new energy vehicle motor controllers, or spacecraft electronic equipment; among them, in a microgravity environment, the non-uniform gradient magnetic field is particularly suitable for replacing gravity as the dominant mechanism for driving convective heat dissipation.

[0030] The heat dissipation optimization method and heat dissipation structure based on gradient magnetic field thermomagnetic control proposed in this invention can bring the following beneficial effects:

[0031] 1. Active and precise control: By using the gradient magnetic field constructed by static permanent magnets, the open-plate heat dissipation performance can be actively, directionally, and quantitatively controlled by adjusting the model and magnetic parameters (number, spacing, magnetic pole direction, intensity), breaking through the limitations of natural convection passive heat dissipation.

[0032] 2. Quiet, efficient and reliable: The entire control process requires no moving parts, consumes no electrical energy (the permanent magnet itself does not consume energy), and is free from noise and vibration. The system has a simple structure, reliable operation, and long lifespan, making it particularly suitable for applications with extremely high requirements for quietness and reliability.

[0033] 3. Significant and parameterizable effects: By optimizing the configuration parameters of permanent magnets, a clear and predictable improvement in heat dissipation performance can be obtained, thus providing clear parameterized guidance for engineering design and application.

[0034] 4. Wide environmental adaptability: The principle of this invention does not rely on gravity. In a microgravity space environment, this gradient magnetic field can effectively replace gravity-driven gas convection, providing a new technical approach to solving the key problem of on-orbit heat dissipation for spacecraft electronic equipment, and achieving a high degree of unification between ground and space heat dissipation technologies.

[0035] 5. Strong engineering applicability: The proposed method has a clear logic, and the heat dissipation structure is easy to process, manufacture and integrate. It can be quickly applied to heat dissipation of high heat flux density electronic devices in multiple high value-added fields such as communication, computing, transportation and aerospace, and has broad industrialization prospects. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0037] Figure 1 A three-dimensional schematic diagram of the outer wall of a flat plate with a single set of permanent magnets.

[0038] Figure 2 A two-dimensional schematic diagram of the outer wall of a flat plate with a single set of permanent magnets.

[0039] Figure 3 A three-dimensional schematic diagram of the outer wall of a flat plate with two sets of permanent magnets.

[0040] Figure 4 A two-dimensional schematic diagram of the outer wall of a flat plate with two sets of permanent magnets.

[0041] Figure 5 A two-dimensional schematic diagram of two sets of permanent magnets with the same magnetic poles arranged on the outer wall of a flat plate.

[0042] Figure 6 A two-dimensional schematic diagram of two sets of permanent magnets with opposite magnetic poles arranged on the outer wall of a flat plate. Detailed Implementation

[0043] To more clearly illustrate the overall concept of the present invention, a detailed description will be provided below with reference to the accompanying drawings and examples.

[0044] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] A method for optimizing heat dissipation of a flat plate based on gradient magnetic field thermomagnetic control includes the following steps:

[0049] At least one permanent magnet is arranged on one or both sides of the flat heat dissipation structure to create a non-uniform gradient magnetic field.

[0050] By adjusting at least one of the following parameters: the number and size of the permanent magnets, the vertical distance between them and the bottom of the flat plate heat dissipation structure, the horizontal distance between them and the surface of the flat plate heat dissipation structure, the magnetic pole direction of the permanent magnets, the arrangement of the permanent magnets, and the residual magnetic induction intensity, the magnetic volume force distribution of the magnetic medium acting around the flat plate and its coupling relationship with the thermal buoyancy force can be changed.

[0051] Based on the adjustment of the above parameters, the temperature field and flow field on the surface of the flat plate are optimized in a targeted manner, so as to achieve active control of the average temperature, the maximum temperature and the overall heat transfer intensity.

[0052] Preferably, when a single permanent magnet is arranged on any side of the flat plate heat dissipation structure, changing the position, size and strength of the permanent magnet can significantly improve the overall heat dissipation capacity.

[0053] Preferably, when dual permanent magnets are arranged sequentially on one or both sides of the flat plate heat dissipation structure, optimizing their spacing, size, strength and magnetic pole direction (in the same direction or opposite direction) can respectively optimize the overall temperature uniformity performance or enhance the heat dissipation of local areas.

[0054] Preferably, when two or more permanent magnets are arranged on one or both sides of the flat plate heat dissipation structure, by coordinating the adjustment of the size, spatial position, vertical distance from the bottom of the flat plate heat dissipation structure, horizontal distance from the surface of the flat plate heat dissipation structure, magnetic induction intensity and magnetic pole arrangement of each magnet unit, it is possible to achieve global optimization of the temperature distribution of the heat dissipation structure or targeted thermal management enhancement of its specific local area.

[0055] A heat dissipation structure for implementing the above method includes:

[0056] Flat panel heat dissipation structure;

[0057] At least one permanent magnet module is arranged on one or both sides of the vertical flat plate heat sink;

[0058] The permanent magnet module and the flat plate heat dissipation structure can be set relatively fixed or relatively movable, so as to adjust the heat dissipation performance by changing the relative positional relationship between the two.

[0059] Preferably, the permanent magnet module can be fixedly connected to the flat plate heat dissipation structure via mounting holes, snap-fit ​​structures, or adhesive bonding, and its relative position can be adjusted by changing the mounting points. The permanent magnet module is an alloy permanent magnet, a ferrite permanent magnet, or other metal permanent magnet. The flat plate heat dissipation structure can be integrated into the heat dissipation system of 5G communication equipment, high-performance computing chips, new energy vehicle power modules, or spacecraft electronic equipment.

[0060] exist Figures 1 to 6 In the diagram, the dimensions of the vertical plate are d, L, D, and the dimensions of the permanent magnet are a, a, L. The left side of the vertical plate is a magnetic medium region, with the permanent magnets in close contact with the wall. The distance between the bottom of a single set of permanent magnets and the bottom of the vertical plate is y. m The distance between the bottom of the upper magnet of the double permanent magnet set and the bottom of the vertical plate is y. m2 The distance between the bottom of the upper magnet and the bottom of the vertical plate is y. m1 .

[0061] Example 1: A single magnet is placed close to the heat dissipation device to form an enhanced heat dissipation structure, such as... Figure 1-2 As shown.

[0062] This embodiment demonstrates how to maximize the overall heat dissipation performance of a tablet using a single permanent magnet, suitable for scenarios requiring extreme heat dissipation capabilities, such as auxiliary heat dissipation for high-performance graphics processors (GPUs).

[0063] Structure and layout:

[0064] Flat panel heat dissipation structure: It is an aluminum heat dissipation substrate, the back of which is tightly attached to an analog chip heat source through thermal grease.

[0065] Permanent magnet module: Uses a permanent magnet with adjustable nominal residual magnetic induction intensity.

[0066] Installation and Adjustment: The permanent magnet module is arranged parallel to its bottom edge on the outside of the flat plate heat dissipation structure. In this embodiment, to achieve a "close-fitting" arrangement, the permanent magnet module is directly bonded and fixed to the outside of the flat plate with high-temperature epoxy resin adhesive, so that its lower edge is flush with the bottom of the vertical flat plate, allowing the permanent magnet to move along the vertical flat plate. The direction of the internal magnetic field lines of the permanent magnet is opposite to the direction of gravitational acceleration (i.e., N pole facing upwards, S pole facing downwards).

[0067] Work process and results:

[0068] When the chip's heat source is working, the plate is heated, and the air around it rises due to the heat, creating natural convection.

[0069] The closely spaced permanent magnets generate a strong non-uniform gradient magnetic field in the space near the plate. This magnetic field exerts a magnetic volume force on the paramagnetic components in the air (mainly oxygen). The magnetic volume force and the thermal buoyancy force produce a synergistic strengthening effect, which significantly accelerates the upward movement of the cooler air in the boundary layer and enhances the shearing action between the hot wall and the cold air.

[0070] Experimental tests show that, compared with the baseline operating condition without a magnetic field, the optimized permanent magnet configuration can significantly improve the overall heat transfer efficiency of the heat dissipation surface, effectively reduce its average temperature and the temperature of key heat sources, thereby ensuring the stable operation of electronic devices.

[0071] Example 2: Optimized temperature uniformity mode for dual-magnet arrangement with co-directional magnetic poles, such as... Figure 3-5 As shown.

[0072] This embodiment demonstrates a scheme to optimize the overall temperature uniformity of a flat plate using two permanent magnets with the same magnetic pole orientation. It is suitable for scenarios with high requirements for temperature consistency, such as high-power LED arrays or certain radio frequency power devices.

[0073] Structure and layout:

[0074] Flat panel heat dissipation structure: It is an aluminum heat dissipation substrate, the back of which is tightly attached to an analog chip heat source through thermal grease.

[0075] Permanent magnet module: It uses two permanent magnets with adjustable nominal residual magnetic induction intensity.

[0076] Installation and adjustment: Two permanent magnets are arranged on the back of the flat plate heat dissipation structure. The direction of the internal magnetic field lines is opposite to the direction of gravitational acceleration (both with the N pole facing up and the S pole facing down). The lower edge of permanent magnet ① is flush with the bottom of the vertical plate, and permanent magnet ② can move along the vertical plate.

[0077] Work process and results:

[0078] Two magnets with the same magnetic poles in the same direction form a stronger and wider symmetrical gradient magnetic field.

[0079] The process by which the magnetic field enhances heat transfer mainly depends on the adjustment of the local convection structure. The heat dissipation enhancement region under the dual-magnet configuration includes: the inlet region where the boundary layer is initially formed, the reattachment region above the permanent magnet ①, and the outlet region where countercurrent flow is dominant.

[0080] This flow structure effectively promotes efficient mixing and heat exchange of hot and cold fluids, significantly optimizes the temperature distribution uniformity of the heat dissipation surface, thereby achieving overall enhancement of heat transfer performance and effective suppression of local hot spots. This optimization effect can be actively and precisely controlled by changing the configuration parameters of the permanent magnet.

[0081] Example 3: A dual-magnet arrangement with opposite magnetic poles enhances heat dissipation, such as... Figure 3 , 4 As shown in Figure 6.

[0082] This embodiment is a further optimization based on embodiment 2, demonstrating a scheme to enhance the heat dissipation of a flat plate heat dissipation structure by using two magnets with opposite magnetic pole directions, which is suitable for scenarios where the heat source is not uniformly distributed.

[0083] Structure and layout:

[0084] Flat panel heat dissipation structure: It is an aluminum heat dissipation substrate, the back of which is tightly attached to an analog chip heat source through thermal grease.

[0085] Permanent magnet module: It uses two permanent magnets with adjustable nominal residual magnetic induction intensity.

[0086] Installation and Adjustment: Two permanent magnets are arranged on the back of the flat plate heat dissipation structure. The lower edge of permanent magnet ① is flush with the bottom of the vertical plate, and the direction of the internal magnetic field lines is opposite to the direction of gravitational acceleration (both N poles are facing up and S poles are facing down). Permanent magnet ② can move along the vertical plate, and the direction of the internal magnetic field lines is the same as the direction of gravitational acceleration (both S poles are facing up and N poles are facing down).

[0087] Work process and results:

[0088] The opposite magnetic pole configuration creates a stronger magnetic field distribution near the flat plate. Compared to a dual magnet with the same magnetic poles, the magnetic field lines of the two permanent magnets do not interfere with or cancel each other out. This results in a wider range of high magnetic fields in a dual magnet with opposite magnetic poles. This magnetic field arrangement is particularly beneficial for enhancing fluid disturbances on the flat plate, suppressing boundary layer development, drawing more "cool air" near the wall, and accelerating heat exchange.

[0089] The results show that by employing a specific synergistic configuration of two magnets with opposite magnetic poles, the overall heat transfer efficiency of the heat dissipation surface can be significantly improved and its average temperature reduced. The coupled magnetic field generated by this synergistic configuration can actively modulate the flow field structure in the near-wall region, which is the key physical mechanism for achieving the aforementioned enhanced heat transfer and homogenized heat dissipation effects.

[0090] Explanation of microgravity environment applications

[0091] The methods and structures described in the above embodiments are also applicable to microgravity environments (such as inside spacecraft). In space, natural convection fails. In this case, the gradient magnetic field generated by the permanent magnets in the embodiments becomes the sole dominant force driving airflow. By rationally designing the arrangement of the permanent magnets (such as using the dual-set magnet arrangement of Embodiments 2 or 3), controlled gas circulation can be actively established under zero-gravity conditions, directionally "pumping" the heat generated by the equipment to the cooler cabin walls, thereby achieving effective thermal management. The structure requires no modification; only the installation position and orientation parameters of the permanent magnets need to be optimized and determined on the ground based on on-orbit thermal simulation results. Through precise ground design and static permanent magnet layout, the complex, energy-intensive, and fault-prone space fluid mechanical pumps are replaced, achieving long-term, reliable, and efficient space thermal management. This method overcomes the limitations of traditional space heat dissipation technologies, providing an efficient and convenient heat dissipation strategy for the thermal control systems of future spacecraft, especially long-term on-orbit space stations and deep space exploration habitats.

[0092] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0093] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A heat dissipation structure based on gradient magnetic field control, characterized in that, include: A heat sink substrate having a cavity structure having an internal space for accommodating a magnetic medium; At least one permanent magnet module is arranged on the heat dissipation surface of the heat sink substrate and / or the inner wall surface of the cavity structure. The permanent magnet module and the heat sink substrate can be fixed or movable relative to each other. The permanent magnet modules are arranged in a preset layout to form an adjustable non-uniform gradient magnetic field, which changes the spatial coupling distribution of the magnetic volume force and thermal buoyancy force of the magnetic medium. This is used to enhance heat transfer, suppress heat transfer, or directionally control heat transfer on the surface of the heat sink and inside the cavity.

2. The heat dissipation structure according to claim 1, characterized in that, The preset layout includes at least one of the following parameters: the number of permanent magnet modules, the vertical distance from the bottom of the heat sink substrate, the horizontal distance from the surface of the heat sink substrate, the magnetic pole direction, the magnet size, and the residual magnetic induction intensity. The magnetic pole direction includes axial magnetization perpendicular to the heat sink surface, tangential magnetization parallel to the heat sink surface, or a combination of both.

3. The heat dissipation structure according to claim 1, characterized in that, Two permanent magnet modules are arranged sequentially on one or both sides of the heat sink substrate. By adjusting the relative vertical distance between the two permanent magnet modules and the bottom of the heat sink substrate, as well as the relative horizontal distance between the two permanent magnet modules and the surface of the heat sink substrate, and configuring their magnetic pole directions to be in the same or opposite directions, the heat dissipation performance is optimized.

4. The heat dissipation structure according to claim 3, characterized in that, When the magnetic poles of the two permanent magnet modules are configured to be in the same or opposite directions, a coupled gradient magnetic field is formed to optimize the overall temperature uniformity of the heat dissipation surface and to directionally enhance the heat dissipation performance of the target area.

5. The heat dissipation structure according to claim 1, characterized in that, The heat sink substrate and the cavity structure form an integral configuration, including an integrally molded structure, a multi-layer stacked structure, a split assembly structure, or an embedded composite structure; the cavity structure is a closed cavity, an open cavity, or a flow cavity with fluid inlets and outlets.

6. The heat dissipation structure according to claim 1, characterized in that, It also includes fin structures, microchannel structures, porous dielectric layers or phase change material layers disposed on heat sink substrates or cavity structures, for synergistic enhancement or regulation of heat dissipation performance.

7. A method for optimizing heat dissipation of a flat plate based on gradient magnetic field thermomagnetic control, used in the heat dissipation structure described in claims 1 to 6, characterized in that, Includes the following steps: (1) A heat sink substrate is provided, the heat sink substrate having a cavity structure having an internal space for accommodating a magnetic medium; (2) At least one permanent magnet module is arranged on the heat dissipation surface of the heat sink substrate and / or the inner wall surface of the cavity structure. The permanent magnet module and the heat sink substrate can be fixed or movable relative to each other to form a non-uniform gradient magnetic field. (3) By adjusting at least one of the following parameters: the number of permanent magnet modules, the vertical distance between the permanent magnet module and the bottom of the heat sink substrate, the horizontal distance between the permanent magnet module and the surface of the heat sink substrate, the magnetic pole direction, the magnet size and the residual magnetic induction intensity, the magnetic volume force distribution of the magnetic medium around the heat sink substrate and its coupling relationship with the thermal buoyancy force are changed. (4) Based on the adjustment in step (3), the gradient magnetic field and the temperature field work together to optimize the temperature field and flow field on the surface of the heat sink substrate, thereby achieving active control over the average temperature, the maximum temperature and the overall heat transfer intensity.

8. The method for optimizing heat dissipation of a flat panel according to claim 7, characterized in that, The active control includes: By constructing magnetic field gradients that are enhanced or weakened along the direction of fluid flow, magnetization forces pointing in the direction of mainstream flow or magnetic resistance opposite to the direction of mainstream flow are generated, thereby enhancing heat transfer to eliminate hot spots or suppressing heat transfer to form a thermal resistance barrier. Alternatively, by constructing a transverse magnetic field gradient perpendicular to the mainstream direction, a transverse force perpendicular to the flow direction can be generated, guiding the fluid to deflect and transport along a preset path, thereby achieving directional heat transfer control. Alternatively, by constructing a periodic or alternating magnetic field distribution, fluid oscillations or vortex flows can be induced, thereby enhancing fluid mixing and heat exchange efficiency. Alternatively, by combining the above methods, the temperature field on the heat sink surface and inside the cavity can be made uniform or a specific temperature distribution can be achieved.

9. The method for optimizing heat dissipation of a flat panel according to claim 8, characterized in that, The method is applied in high heat flux density thermal management of power semiconductor devices, LED lighting equipment, 5G communication base station equipment, data center servers, new energy vehicle motor controllers, or spacecraft electronic equipment; among them, in microgravity environments, the non-uniform gradient magnetic field is particularly suitable for replacing gravity as the dominant mechanism for driving convective heat dissipation.

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