Magnetic device, preparation method thereof and electronic equipment

Abstract

The invention relates to the technical field of magnetic devices, and discloses a magnetic device and a preparation method thereof, and electronic equipment, and the magnetic device comprises a magnetic core which is integrally formed; the coil is arranged in the magnetic core, and the end part of the coil is exposed out of the outer surface of the magnetic core so as to be used as an end electrode of the magnetic device; the heat dissipation body is arranged on the magnetic core, the two ends of the heat dissipation body at least partially cover the end, provided with the end electrode, of the magnetic core and the other end, opposite to the end electrode, of the magnetic core respectively, and the side, facing the magnetic core, of the heat dissipation body is embedded in the magnetic core and attached to the magnetic core. The performance and reliability of the magnetic device are improved.

Description

Technical Field

[0001] This application relates to the field of magnetic device technology, specifically to a magnetic device and its preparation method, and electronic equipment. Background Technology

[0002] With the rapid development of the electronic information industry, magnetic devices are increasingly widely used in fields such as communications, automotive electronics, and power management. Taking inductors as an example, as core energy storage and filtering components in switching power supplies and power conversion modules, their performance directly affects the efficiency, stability, and reliability of the entire system. With the rapid development of fields such as artificial intelligence (AI) servers, high-performance computing (HPC), communication base stations, and new energy vehicles, extremely high power density and ultra-high current output requirements are placed on power systems. For example, the power consumption of the GPUs or dedicated AI chips in AI servers has climbed to hundreds or even thousands of watts, while the operating voltage has dropped to below 1V. Providing huge power at low voltage inevitably requires inductors to carry saturation currents of 50A to 100A or even higher. When such a large current passes through the inductor windings, it will generate significant Joule heat. At the same time, under high-frequency switching conditions, the magnetic core will also generate non-negligible core losses. If these two types of heat cannot be dissipated in a timely and effective manner, the internal temperature of the inductor will rise sharply.

[0003] The heat dissipation solutions in related technologies generally adopt the method of external or additional heat sinks (plates), and fix the metal heat sink to the outside of the magnetic core coating layer by thermally conductive adhesive. This traditional heat dissipation design has a long and high-resistance heat conduction path, resulting in low heat dissipation efficiency of the device. This not only causes the performance degradation of magnetic materials and the aging of winding insulation, but also leads to permanent damage to the device in severe cases, which seriously restricts the further improvement of device performance and long-term operational reliability. Summary of the Invention

[0004] In view of this, this application provides a magnetic device and its preparation method, as well as an electronic device, to solve the aforementioned technical problems.

[0005] In a first aspect, embodiments of this application disclose a magnetic device, comprising: The magnetic core is integrally formed. A coil, wherein the coil is disposed within the magnetic core and the ends of the coil are exposed on the outer surface of the magnetic core to serve as end electrodes of the magnetic device; A heat sink is disposed on the magnetic core. The two ends of the heat sink at least partially cover one end of the magnetic core having the end electrode and the other end opposite to the end electrode, respectively. The side of the heat sink facing the magnetic core is embedded in the magnetic core and is in contact with the magnetic core.

[0006] In one possible example, the outer surface of the magnetic core is provided with functional slots that surround the coil, and the heat sink is connected within the functional slots.

[0007] In one possible example, the portion of the heat sink located at one end of the magnetic core having the end electrode and the other end opposite the end electrode has a predetermined tilt angle between its side facing the magnetic core and the end face of the magnetic core.

[0008] In one possible example, the portion of the heat sink located at one end of the magnetic core having the end electrode and the other end opposite the end electrode is in the same plane as the end face of the magnetic core.

[0009] In one possible example, the two heat sinks on one end of the magnetic core having the end electrode and the other end opposite the end electrode are spaced apart from each other or connected as one unit.

[0010] In one possible example, the heat sink covers at least a portion of the sidewalls of the magnetic core on both sides.

[0011] In one possible example, on the magnetic core, the extension direction of the two ends of the coil is the same as the length direction of the heat sink along the sidewall of the magnetic core.

[0012] In one possible example, the heat sink is integrally pressed with the magnetic powder material of the magnetic core.

[0013] In one possible example, the connection gap between the heat sink and the functional slot within the functional slot is less than a preset gap value.

[0014] In one possible example, on a vertical projection in a first direction, the functional slot and the heat sink cover the coil, the first direction being the direction of extension of the upper / lower end of the magnetic core, the coils being spaced apart within the magnetic core, and the coils being transversely placed within the magnetic core along a second direction, wherein the second direction is perpendicular to the first direction.

[0015] In one possible example, the thickness of the two heat sinks on one end of the magnetic core having the end electrode and the other end opposite the end electrode increases face-to-face along a third direction, wherein the third direction is perpendicular to the first direction and the second direction.

[0016] In one possible example, the heat sink includes a first heat sink and a second heat sink disposed at both ends of the first heat sink. The first heat sink is fitted into a functional slot on the sidewall of the magnetic core, and the second heat sink is fitted into a functional slot at both ends of the magnetic core. The side of the second heat sink facing the magnetic core maintains a preset angle with the end face of the magnetic core.

[0017] In one possible example, the side of the first heat dissipation part away from the magnetic core is located in the same plane as the sidewall of the magnetic core, and the side of the second heat dissipation part away from the magnetic core is located in the same plane as the end face of the magnetic core.

[0018] Secondly, embodiments of this application disclose a method for fabricating a magnetic device, including: The magnetic powder and the coil are pressed together to form a magnetic core that encloses the coil. Assemble the heat sink to the magnetic core, and fill the magnetic powder on the magnetic core with the heat sink and perform secondary pressing so that the side of the heat sink facing the magnetic core is embedded in the magnetic core and fits the magnetic core. The magnetic core after secondary pressing is annealed. The surface of the annealed magnetic core is ground to remove residual magnetic powder and expose the heat sink and end electrodes. The end electrodes are the portions of the coil ends exposed on the outer surface of the magnetic core, and the two ends of the heat sink at least partially cover one end of the magnetic core having the end electrodes and the other end opposite to the end electrodes, respectively. The polished magnetic core is coated, and laser peeling and electroplating are performed on the exposed heat sink and end electrode areas.

[0019] Thirdly, embodiments of this application disclose an electronic device including the magnetic device described in any of the above embodiments.

[0020] In summary, compared with the prior art, this application discloses a magnetic device and its preparation method, as well as an electronic device. The magnetic device includes a magnetic core, which is integrally formed. A coil is disposed inside the magnetic core, and the end of the coil is exposed on the outer surface of the magnetic core to serve as the end electrode of the magnetic device. A heat sink is disposed on the magnetic core, and both ends of the heat sink at least partially cover one end of the magnetic core with the end electrode and the other end opposite to the end electrode, respectively. The side of the heat sink facing the magnetic core is embedded in the magnetic core and is in close contact with the magnetic core. That is, through the above arrangement, the performance and reliability of the magnetic device are improved. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the first type of magnetic device according to the embodiments of this application; Figure 2 yes Figure 1 A cross-sectional structural diagram of a magnetic device; Figure 3 This is a schematic diagram of the structure of the second type of magnetic device according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the third type of magnetic device according to an embodiment of this application; Figure 5 This is a flowchart illustrating the fabrication process of the magnetic device according to an embodiment of this application. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the claims.

[0024] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0025] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0026] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0027] In the description of this application, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] The technical solutions shown in this application will be described in detail below through specific embodiments. It should be noted that the order of description of the following embodiments is not intended to limit the priority of the embodiments.

[0029] As described in the background art, the heat dissipation solutions for related devices generally adopt the method of external or additional heat sinks (plates), and the metal heat sink is bonded to the outside of the magnetic core coating layer by thermally conductive adhesive. This traditional heat dissipation design has a long and high-resistance heat conduction path, resulting in low heat dissipation efficiency of the device.

[0030] Although we recognize that removing the thermally conductive adhesive layer between the magnetic core and the metal heat sink can simplify the heat conduction path and improve the heat dissipation efficiency of the device to some extent, further research shows that the insulating coating layer of the magnetic core body and the inherent insulating enamel film on the surface of the metal heat sink still constitute a significant thermal resistance barrier between the two. These inherent insulating layers still significantly hinder the efficient conduction of heat from the magnetic core to the heat sink.

[0031] Based on this insight, this application conceives a fundamental solution that abandons the traditional process of "first forming the magnetic core and covering it with an insulating layer, and then attaching the heat sink externally by adhesive or mechanical means." Instead, the heat sink is integrated with the magnetic powder material of the magnetic core as an embedded component through integral pressing. This allows the exposed working surface of the heat sink to achieve direct and close physical contact with the magnetic material of the magnetic core, thereby completely eliminating multiple high thermal resistance interfaces such as the insulating coating layer, thermally conductive adhesive layer, and enameled film on the surface of the heat sink in the traditional structure.

[0032] Based on this inventive concept, this application discloses a magnetic device, please refer to... Figure 1 and Figure 2 The magnetic device includes a magnetic core 1, a coil 2, and a heat sink 4.

[0033] In the specific implementation process, the magnetic core 1 is integrally formed, the coil 2 is disposed inside the magnetic core 1, and the end of the coil 2 is exposed on the outer surface of the magnetic core 1 to serve as the end electrode 3 of the magnetic device and electrically connected to the external circuit. The heat sink 4 is disposed on the magnetic core 1, and the side of the heat sink 4 facing the magnetic core 1 is embedded in the magnetic core 1 and is in contact with the magnetic core 1.

[0034] Therefore, in the magnetic device of this application embodiment, the magnetic core 1 is integrally formed with a dense overall structure. The coil 2 can be encapsulated inside the magnetic core 1 during the forming process of the magnetic core 1. The two ends of the heat sink 4 at least partially cover one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3, respectively, to ensure a firm connection between the heat sink 4 and the magnetic core 1, and match the area occupied by the coil 2 inside the magnetic core 1. The heat sink 4 is in direct contact with the magnetic core 1 inside the magnetic core 1, thereby constructing an efficient and short-path heat conduction channel from the internal heat source (coil 2 and magnetic core 1) to the external heat dissipation coil 2 → magnetic core 1 → heat sink 4. This improves the long and high-resistance heat conduction path (which contains a variety of different materials, forming a series of multi-layer thermal resistance) in the related technology, which is coil → magnetic core → covering layer → thermally conductive adhesive / air gap → heat sink. It completely eliminates the two high-thermal-resistance links of "covering layer" and "interface medium (adhesive / air) between heat sink and covering layer" that exist in the traditional structure.

[0035] Understandably, in related technologies, to ensure electrical insulation, the coating layer is usually made of polymer materials such as epoxy resin, which has an extremely low thermal conductivity, constituting the main bottleneck for heat conduction. There is usually an air gap / thermal conductive adhesive between the heat sink and the coating layer. Air has an extremely low thermal conductivity (0.026 W / m·K), and even with high-performance thermal conductive adhesives, its thermal conductivity (1-5 W / m·K) is limited. The thermal conductivity (W / m·K) is also much lower than that of metals. Due to factors such as surface flatness and assembly pressure, it is difficult to achieve ideal full contact between the heat sink and the cladding layer, resulting in significant contact thermal resistance. As a result of the low thermal conductivity of the cladding layer and the interstitial medium, as well as the limited equivalent contact area, the total thermal resistance from the heat source to the heat sink remains high. This causes the core temperature of the device to easily exceed 100°C during high-power operation, which not only causes the performance degradation of magnetic materials and the aging of winding insulation, but also leads to permanent damage to the device in severe cases. Therefore, the embodiments of this application eliminate the bottleneck of low thermal conductivity medium in the related technology, that is, the cladding layer between the heat sink and the magnetic core is omitted, avoiding the process that heat must pass through the polymer insulation layer with extremely low thermal conductivity. At the same time, the heat sink 4 is directly combined with the functional slot 11 of the magnetic core 1. The two are in direct and close contact between metal and dense magnetic body. It can be regarded as the absence of an additional interface layer composed of air or thermally conductive adhesive, and there is no contact thermal resistance caused by poor assembly, thereby improving the performance and reliability of magnetic devices.

[0036] Preferably, the heat sink 4 is disposed on both sides of the magnetic core 1, and the two ends of the heat sink 4 at least partially cover one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3, so as to achieve symmetrical heat dissipation on both sides, that is, heat conduction and dissipation are carried out simultaneously from both sides of the magnetic core 1, effectively utilizing the lateral space of the device, significantly increasing the heat dissipation surface area, and improving the overall heat dissipation capacity and efficiency. At the same time, the dual-sided heat dissipation helps to conduct the heat generated inside the magnetic core 1 (especially the coil 2 area) to both sides more quickly and evenly, reducing the temperature gradient inside the magnetic core 1, avoiding local overheating that may be caused by uneven heat dissipation, thereby improving the working stability and reliability of the device.

[0037] To further improve the connection strength between the magnetic core 1 and the heat sink 4, and to optimize the spatial dimensions of the magnetic device, the outer surface of the magnetic core 1 is provided with a functional slot 11 surrounding the coil 2. The heat sink 4 is connected within the functional slot 11. Specifically, the main body of the heat sink 4 is accommodated and fixed in the corresponding functional slot 11, and its exposed surface is directly in contact with the bottom and wall of the functional slot 11. That is, the arrangement area of ​​the functional slot 11 around the coil 2 on the magnetic core 1 is matched with the heat sink 4. The heat sink 4 can be regarded as being embedded in the corresponding functional slot 11 and in direct contact with the slot body of the functional slot 11. The two ends of the coil 2 at least partially cover one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3, respectively. They are distributed in the area occupied by the coil 2 inside the magnetic core 1 in accordance with the functional slot 11. This not only provides precise positioning and stable mechanical support for the heat sink 4, enhancing the connection strength and integrity between the two, but also helps to control the embedding depth of the heat sink 4, making the device shape more compact and flat, which is conducive to layout and installation in high-density circuits. That is, while ensuring excellent heat dissipation performance, the functional slot 11 further improves the mechanical reliability and space utilization efficiency of the device.

[0038] In one possible implementation of this application, in order to further improve the connection strength and overall heat dissipation effect between the magnetic core 1 and the heat sink 4, the end face mating structure of the heat sink 4 and the magnetic core 1 has been further optimized. Specifically, the heat sink 4 that at least partially covers one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3, that is, the part of the heat sink 4 located at one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3, has a preset tilt angle (as shown in the figure Q) on the side facing the magnetic core 1.

[0039] Therefore, the side of the heat sink 4 covering at least part of the magnetic core 1 with one end having the end electrode 3 and the other end opposite to the end electrode 3 facing the magnetic core 1 is designed as an inclined surface. The acute angle between the inclined surface and the end face of the magnetic core 1 is the preset tilt angle. Based on the preset tilt angle, the end covering part of the heat sink 4 can be wedge-shaped in cross-section. When the heat sink 4 is combined with the magnetic core 1, this wedge-shaped structure can guide the magnetic core powder filling more smoothly and can help to form an interlocking effect between the two to a certain extent, thereby enhancing the bonding strength.

[0040] In this embodiment, the pre-set tilt angle design optimizes the flow and filling of the magnetic core powder during secondary pressing, ensuring a tight, gapless contact between the heat sink 4 and the magnetic core 1 in the mating area, further reducing interfacial thermal resistance. On the other hand, this tilt angle structure substantially increases the equivalent contact area between the heat sink 4 and the magnetic core 1 in the mating area (compared to a purely vertical surface contact), providing a better path for the direct conduction of heat from the end face of the magnetic core 1 to the heat sink 4, thereby further improving the overall heat dissipation efficiency in subtle ways. This design is particularly suitable for high-power applications with extreme requirements for heat dissipation performance.

[0041] Preferably, the preset tilt angle ranges from 1° to 3° to achieve the best balance between process feasibility, mechanical bonding strength and heat dissipation performance.

[0042] Specifically, the preset tilt angle of 1° to 3° corresponds to the bottom slope of the functional slot 11. This facilitates the filling of the gap by the magnetic powder during secondary pressing, achieving a tight bond between the heat sink 4 and the magnetic core 1. It avoids incomplete filling or difficulty in demolding due to excessively large or small angles. Furthermore, the tilt angle within this range can form a moderate wedge-shaped interlocking effect between the heat sink 4 and the magnetic core 1, enhancing the bonding strength between the two in the end area and resisting displacement or separation caused by thermal expansion and contraction or mechanical stress. In addition, this tilt angle design effectively increases the effective contact area between the heat sink 4 and the magnetic core 1 within a limited space. If the preset tilt angle is less than 1°, its effect on increasing the contact area is negligible, approaching parallel contact. If the tilt angle is greater than 3°, it may cause the end structure of the heat sink 4 to be too sharp or occupy too much space, affecting the overall size of the device or the layout of surrounding components, and the marginal improvement in heat dissipation performance is limited.

[0043] By limiting the preset tilt angle to a preferred range of 1° to 3°, this embodiment maximizes the optimization of the heat conduction interface between the heat sink 4 and the magnetic core 1 while ensuring a smooth and reliable manufacturing process. This specific angle optimization allows the heat from the coil 2 and the magnetic core 1 to be transferred to the heat sink 4 more efficiently through this low-resistance, large-area interface when the magnetic device is operating at high power. This is an important design guarantee for achieving excellent heat dissipation performance and high reliability of the device.

[0044] Optionally, at one end of the magnetic core 1 with end electrode 3 and the other end opposite to end electrode 3, the bottom of the functional groove 11 has a slope toward the center of the magnetic core 1 to adapt to the preset tilt angle structure design of the heat sink 4.

[0045] In one example, another implementation of the aforementioned magnetic device is provided. Specifically, the cross-sectional profiles of two heat sinks 4 on one end of the magnetic core 1 with end electrode 3 and the other end opposite to end electrode 3 gradually expand towards each other in a face-to-face direction. In other words, the cross-sectional dimension (width or thickness) of each heat sink 4 is larger than its outer portion away from the center of the magnetic core 1 on the side closer to the centerline of the magnetic core 1 or closer to the other heat sink 4, thereby forming a wedge-shaped, trapezoidal, or wing-like profile. This "gradually expanding" profile design can be combined with any of the aforementioned embodiments. For example, the heat sink 4 can simultaneously have a preset tilt angle facing the end face of the magnetic core 1, while its cross-section presents this gradually expanding shape. The two optimize the heat dissipation interface from different spatial dimensions.

[0046] The portion of the heat sink 4 that gradually expands towards the center can form a larger area of ​​close contact with the sidewalls and bottom of the functional slot 11. This directly increases the heat conduction area from the magnetic core 1 to the heat sink 4. At the same time, the gradually expanding contour helps to guide and diffuse the heat generated by the coil 2 inside the magnetic core 1 more smoothly to the wider cross section of the heat sink 4, reducing the heat flow congestion effect, helping to reduce the temperature rise gradient of the heat sink 4 itself, improving the overall heat dissipation uniformity, and the gradually expanding shape can form a certain mechanical interlock, which helps to resist the risk of the heat sink 4 loosening from the functional slot 11 of the magnetic core 1 when subjected to thermal stress or vibration, thus improving the long-term reliability of the structure.

[0047] Preferably, at one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3, the thickness of the end of the heat sink 4 away from the sidewall of the magnetic core 1 is greater than the thickness of the rest of the heat sink 4. That is, when the heat sink 4 is embedded in the magnetic core 1, the thickness of the end away from the sidewall of the magnetic core 1 (i.e., the outer end) is designed to be greater than the thickness of the rest of the heat sink 4. This makes the heat sink 4 appear as a thicker outer end in the thickness profile, which is equivalent to locally increasing the heat capacity and heat mass of the outer end region of the heat sink 4. It is also compatible with the preset tilt angle structure design of the aforementioned embodiment. This helps the heat sink 4 absorb and temporarily store more instantaneous heat peaks, slow down the temperature rise rate, and resist thermal shock. The thickened outer end design also enhances the structural rigidity of the outermost part of the heat sink 4, making it less prone to bending or deformation during handling, assembly, or mechanical stress, thereby protecting the precise thermal contact interface between it and the magnetic core 1.

[0048] In one example, unlike the aforementioned embodiment with a preset tilt angle, the portion of the heat sink 4 located at one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3 is parallel to the end face of the magnetic core 1. This design means that the end covering portion of the heat sink 4 forms a large-area, full-area face-to-face parallel contact with the end face of the magnetic core 1, and the heat sink 4 can make face-to-face parallel contact with the bottom of the functional slot 11, thereby making the end face of the magnetic core 1 and the bottom of the functional slot 11 have good flatness, thus achieving a tight fit with the heat sink 4. The parallel contact design aims to eliminate any potential contact non-uniformity caused by the tilt angle, theoretically maximizing the contact area within a given coverage area, and providing a uniformly distributed interface pressure for heat transfer, which is beneficial to reducing the heat flux density per unit area and the interface contact thermal resistance.

[0049] In one example, in conjunction with any of the foregoing embodiments, a portion of the heat sink 4 located at one end of the magnetic core 1 having the end electrode 3 and the other end opposite to the end electrode 3 is located on the same plane as the end face of the magnetic core 1. That is, after the heat sink 4 is fitted into the magnetic core 1 or the functional slot 11 of the magnetic core 1, its extension structure covering at least part of both ends of the magnetic core 1 (i.e., one end having the end electrode 3 and the other end opposite to the end electrode 3) is located on the same plane as the corresponding end face of the magnetic core 1, forming a flat integrated surface.

[0050] The completely flush end face eliminates any tiny steps or gaps in the axial height between the heat sink 4 and the magnetic core 1, ensuring that the heat conduction path from the end face of the magnetic core 1 to the end of the heat sink 4 is the shortest and the interface is continuous. This minimizes the microscopic contact thermal resistance caused by surface unevenness. At the same time, the flat and integrated end face facilitates stable and uniform contact between the device and the circuit board pads during subsequent surface mount technology (SMT). In addition, this structure reduces stress concentration that may be caused by height difference, improving the mechanical reliability of the device.

[0051] In one example, to optimize the spatial layout between the heat sinks 4 at both ends of the magnetic core 1, the two heat sinks 4 on the end of the magnetic core 1 with the end electrode 3 or the other end opposite to the end electrode 3 are spaced apart from each other. That is, the two heat sinks 4 covering both ends of the magnetic core 1 (i.e., the end with the end electrode 3 or the other end opposite to the end electrode 3) are not closely adjacent on the end face plane of the magnetic core 1, but are reserved with a specific gap between them. This gap is located between the relative edges of the two heat sinks 4. In this way, while ensuring the effective heat dissipation area, unnecessary heat sink material usage can be reduced, which helps to miniaturize and lighten the device. It can also avoid the opening of excessive functional slots 11 on the end face of the magnetic core 1, thereby improving the overall cost performance of the device.

[0052] Preferably, this spacing distance is the same as the spacing distance between adjacent coils 2 within the magnetic core 1, thereby achieving spatial matching between the external heat dissipation structure and the internal heat source distribution. This allows the area with the most concentrated heat generation (between coil turns) to obtain a more direct and unobstructed heat dissipation path from above, which is beneficial for heat to be conducted more efficiently to the heat sink 4 above after it is generated from the heat source. This reduces the lateral diffusion distance and heat accumulation of heat inside the magnetic core 1. Furthermore, this layout helps to guide heat flow, making the temperature distribution on the magnetic core 1 and the heat sink 4 more uniform, avoiding local overheating hot spots, thereby improving the overall heat dissipation balance and reliability of the device.

[0053] Continue to refer to Figure 3 Unlike the aforementioned embodiment where the heat sinks 4 are spaced apart, the two heat sinks 4 on one end of the magnetic core 1 with the end electrode 3 or the other end opposite to the end electrode 3 are connected to each other to form an integrated heat dissipation structure. The two heat sinks 4 are connected as one, which significantly improves the rigidity of the heat dissipation structure itself and the overall structural strength after it is combined with the magnetic core 1 or the functional slot 11 of the magnetic core 1. It can better resist deformation or displacement that may be caused by external force or thermal stress, and the device has higher reliability. Moreover, as an integrated heat dissipation structure with a single part, it is not necessary to align and fix the two independent heat sinks 4 separately during assembly, which simplifies the assembly steps and helps to ensure the positional accuracy and symmetry of the two heat sinks 4 relative to the magnetic core 1, thereby improving product consistency and yield.

[0054] In one possible implementation of this application, the magnetic device has a heat dissipation structure design with different sidewall coverage areas. On the one hand, on both sides of the magnetic core 1, the heat sink 4 partially covers the sidewall of the magnetic core 1, while the area of ​​the sidewall near the front end and / or rear end of the magnetic core is not directly covered by the heat sink 4. These areas are still the magnetic core body material. This design optimizes material cost and weight while ensuring the heat dissipation performance of the core heat-generating area.

[0055] Or such as Figure 4 As shown, on both sides of the magnetic core 1, the heat sink 4 completely covers the sidewall of the magnetic core 1. In this embodiment, the heat sink 4 achieves complete coverage of the entire sidewall of the magnetic core 1. That is, the heat sink 4 starts from near the front end of the magnetic core 1 and extends continuously to cover the rear end of the magnetic core 1. This design achieves the maximum possible contact area between the heat sink 4 and the magnetic core 1 in the sidewall direction, and establishes the most direct and continuous heat conduction path from the entire surface of the sidewall of the magnetic core 1 to the external environment to ensure optimal heat dissipation capacity.

[0056] Preferably, on the magnetic core 1, the extension direction of both ends of the coil 2 is the same as the length direction of the heat sink 4 along the side wall of the magnetic core 1. That is, in this embodiment, the extension direction of both ends of the coil 2 embedded inside the magnetic core 1 is the same as the direction in which the heat sink 4 covers the side wall of the magnetic core 1. This directional consistency means that the main conduction path of the heat generated by the coil 2 (along its conductor axis, which is also the direction where the winding is most dense and the heat source is most concentrated) is spatially parallel to the main and largest area low thermal resistance heat dissipation channel provided by the heat sink 4 on the magnetic core 1. Therefore, heat can be transferred from the coil 2 to the magnetic core 1 in a relatively uniform manner. After coil 2 is generated, it can be conducted directly and in the shortest way along its own extension direction to the heat sink 4 located in the same direction as the side wall of magnetic core 1. This shortens the effective heat conduction distance from the core heat source to the main heat dissipation interface, and aligns the distribution of the main heat source (coil 2) with the main heat dissipation structure (heat sink 4) in space, realizing the system-level thermal design of "matching heat source distribution with heat dissipation channel". This allows the heat sink 4 to collect and dissipate the main heat generated by coil 2 in the most efficient way, eliminate heat dissipation blind spots, and significantly improve the overall heat dissipation efficiency.

[0057] It should be noted that the heat sink 4 and the magnetic powder material of the magnetic core 1 are integrally pressed and formed, which makes the heat sink 4 and the magnetic core 1 or the functional groove 11 of the magnetic core 1 fit together without gaps. Then the magnetic powder and the surface of the heat sink 4 form an extremely tight contact at the microscopic level, and even under certain conditions, limited diffusion occurs at the interface, forming a strong mechanical interlock and micro-metallurgical bond. This ensures a huge effective contact area and extremely low interfacial contact thermal resistance.

[0058] In this embodiment, the side of the heat sink 4 facing the magnetic core 1 is embedded in the magnetic core 1 and is in contact with the magnetic core 1. In terms of this "contact", the "contact" defined in this application embodiment includes the meaning of engineering manufacturing dimension, which aims to describe an interface bonding state achieved by the heat sink 4 and the magnetic core 1. This "contact" state, at a macroscopic or conventional observation scale (e.g., resolution of 10 micrometers and above), is manifested as direct contact between the heat sink 4 and the magnetic core 1, or between the heat sink 4 and the functional slot 11, or a continuous gap with zero gap that cannot be identified by the naked eye or conventional detection methods. At the same time, at a microscopic or ultra-high precision scale (e.g., resolution below 10 micrometers, or even nanometers), due to the surface roughness of the material itself, the precision limit of the manufacturing equipment, and the microscopic characteristics of powder flow in the molding process, there may inevitably be discontinuous and extremely small gaps at the interface between the heat sink 4 and the magnetic core 1, or between the heat sink 4 and the functional slot 11. These gaps are still considered as defining features of the contact between the heat sink 4 and the magnetic core 1.

[0059] In order to define the microscopic or ultra-high precision scale state, this embodiment introduces a quantitative engineering parameter, namely a preset gap value. Therefore, in the context of this embodiment, the technical state of "heat sink 4 and magnetic core 1 are in contact" can be defined as meeting the following conditions: the connection gap between heat sink 4 and magnetic core 1 is less than the preset gap value; or the connection gap between heat sink 4 and functional slot 11 is less than the preset gap value.

[0060] Optionally, the preset gap value ranges from 1µm to 3µm, meaning the preset gap value is set to no more than 3µm to minimize the presence of low thermal conductivity air medium at the interface between the heat sink 4 and the magnetic core 1. At the same time, the design of this parameter ensures that each device has a highly consistent interface contact quality, thereby ensuring batch stability and high reliability of the product's heat dissipation performance and avoiding the risk of local overheating caused by excessive or uneven gaps.

[0061] Meanwhile, the above definition indicates that the "fitting" in this embodiment does not demand a theoretically perfect, absolutely zero-gap mathematical contact, but rather covers and protects the substantially tight contact interface that can be achieved under the existing high-precision manufacturing capabilities and can ensure ultra-low thermal resistance conduction effect. Any implementation in which the interface gap between the heat sink 4 and the magnetic core 1 is controlled within a preset gap value (such as 3μm) is considered to be within the "fitting" range defined in this embodiment, and can thereby achieve the core objective of eliminating the traditional high thermal resistance dielectric layer and greatly improving heat dissipation efficiency.

[0062] This embodiment constructs an XYZ spatial coordinate system, with Figure 1 For example, the X-axis direction can be regarded as the first direction, the Y-axis direction as the second direction, and the Z-axis direction as the third direction. The first direction can also be regarded as the upper / lower end extension direction of the magnetic core 1, that is, the direction perpendicular to the upper or lower surface of the magnetic core 1 (usually the height direction of the magnetic core). The second direction can also be regarded as the front / rear end extension direction of the magnetic core 1, that is, the direction perpendicular to the front or rear end face of the magnetic core 1 (usually the width direction of the magnetic core). The third direction can also be regarded as the left / right side extension direction of the magnetic core 1, that is, the direction perpendicular to the left or right side face of the magnetic core 1 (usually the length direction of the magnetic core). Of course, this embodiment is not limited to this. XYZ can also be any other direction that is perpendicular to each other in space in actual needs, which will not be elaborated here.

[0063] In one possible implementation of this application, on the vertical projection in the first direction, the functional slot 11 and the heat sink 4 cover the coil 2. That is, in the vertical projection from the top of the magnetic core 1 downward, the projection outline of the functional slot 11 and the heat sink 4 embedded therein covers the projection outline of the coil 2.

[0064] Thus, after heat is generated from coil 2, it can be directly conducted to the heat sink 4 above / below along the first direction, avoiding the inefficient path where heat must travel a long distance laterally to reach the heat sink. Moreover, this projection coverage relationship ensures that the heat sink 4 is accurately positioned on the key heat conduction path above / below the heat source (coil 2) that needs to be dissipated, achieving the most efficient allocation of heat dissipation resources to the heat source.

[0065] Preferably, the ratio of the projected area of ​​the heat sink 4 to the projected area of ​​the coil 2 in the vertical projection of the first direction ranges from 0.8 to 1.2. Based on this ratio range, the heat dissipation capacity is quantitatively defined from a geometric perspective. This ensures that the heat sink 4 must have a sufficiently large "heat collection window" directly above / below the heat source, providing a basic area guarantee for efficient heat dissipation. This allows the thermal resistance to be systematically controlled. At the same time, this ratio range guides the design to find the optimal solution between heat dissipation performance and economic benefits. It avoids reliability problems caused by insufficient heat dissipation and also prevents resource waste caused by over-design.

[0066] Of course, this projection coverage requirement can work in conjunction with all the aforementioned embodiments. For example, the heat sink 4 can be semi-embedded or fully embedded, can have an angle, can be flush with the end face of the magnetic core 1, its thickness can be non-uniform, its sidewall coverage range can be partial or complete, and it can be integrally pressed with the magnetic core 1. However, regardless of the specific form, its structural parts cover the coil 2 in the projection in the first direction.

[0067] In one example, the specific arrangement of coil 2 inside magnetic core 1 is optimized. Specifically, coil 2 is arranged at intervals inside magnetic core 1, and coil 2 is placed horizontally inside magnetic core 1 along the second direction.

[0068] The spaced coils 2 help to make the generated magnetic field more uniformly distributed inside the magnetic core 1, reducing the phenomenon of excessively high local magnetic flux density. This helps to reduce the loss of the magnetic core 1 (such as eddy current loss and hysteresis loss) under high frequency operation and reduce heat generation. In addition, the design of the coils 2 being placed horizontally along the second direction and covered by the heat sink 4 on the projection of the first direction creates an advantageous heat dissipation channel. This allows the coils 2 to further optimize the magnetic device from the dimensions of heat source shape and internal structure. It not only forms a synergy with the external heat sink 4 structure to improve heat dissipation efficiency, but also helps to improve electromagnetic performance and mechanical reliability.

[0069] Preferably, the two ends of the coil 2 are bent along the first direction, thereby changing its original extension path. The bent ends of the coil 2 are exposed on the same end face of the magnetic core 1 and are plated with a metal layer to serve as the end electrode 3 of the magnetic device. This allows the device to be soldered on one side of the circuit board, simplifies the surface mount technology (SMT) process, and reduces the wiring space occupied on the PCB, which is conducive to achieving higher circuit board assembly density.

[0070] Meanwhile, since the end electrodes 3 are concentrated at one end, the remaining end faces of the magnetic core 1 can be covered more completely and less disturbed by the heat sink 4. This provides favorable conditions for the heat sink 4 to achieve a larger area coverage and a more optimized shape design, thus minimizing the conflict between heat dissipation design and electrical design.

[0071] Optionally, the end electrode 3 and the heat sink 4 located on the same end face of the magnetic core 1 are on the same plane, or the end electrode 3 protrudes from the heat sink 4, so as to adapt to the external mounting structure according to the actual installation environment requirements.

[0072] In one example, the thickness of two heat sinks 4 on one end of the magnetic core 1 with end electrode 3 and the other end opposite to end electrode 3 increases gradually along a third direction. When these two heat sinks 4 with increasing thickness are aligned with the end face of the magnetic core 1 and embedded in the functional slot 11, the thicker inner part facing the central region of the magnetic core 1 will naturally form an angle between its inner surface (the side facing the end face of the magnetic core 1) and the end face of the magnetic core 1. This angle can be the aforementioned preset tilt angle, thereby ensuring that the heat sink 4 and the magnetic core 1 achieve a tight and gapless contact in the end region, reducing the interface thermal resistance, and substantially increasing the equivalent contact area between the heat sink 4 and the magnetic core 1 in the end region. This provides a better path for heat conduction from the end face of the magnetic core 1 to the heat sink 4, thereby further improving the overall heat dissipation efficiency in subtle ways.

[0073] Preferably, this embodiment refines and limits the key dimensional ratio between the heat sink 4 and the coil 2. Specifically, the ratio of the maximum thickness of the heat sink 4 (as shown in the attached figure H) to the thickness of the coil 2 ranges from 0.3 to 0.7 to ensure that the heat dissipation structure achieves the best balance between material efficiency, thermal performance and space occupation. This ensures that the heat sink 4 has sufficient mass (heat capacity) and thermal conduction cross section to effectively carry and transfer the main heat generated by the coil 2. If the ratio is too low, the heat sink 4 may be too thin, with insufficient heat capacity, and the temperature rises too quickly under transient high current. Furthermore, its lateral thermal resistance may be too large, making it impossible to quickly diffuse heat from the contact surface outward, resulting in a heat dissipation bottleneck and affecting heat dissipation efficiency. If the ratio is too high, the heat sink 4 will be too thick and heavy, which will significantly increase the amount and cost of heat dissipation material. In addition, an excessively thick heat sink 4 may require the creation of excessively deep functional slots 11 on the magnetic core 1, which may weaken the mechanical strength of the magnetic core 1 or excessively encroach on the effective volume of the magnetic core 1, potentially affecting electrical parameters such as magnetic flux path and inductance, and is also not conducive to the miniaturization and weight reduction of the device.

[0074] Furthermore, the heat sink 4 is fitted into the functional groove 11 on the side wall of the magnetic core 1 along a third direction, and the heat sink 4 and the side wall are located on the same plane, forming a smooth, continuous, and stepless complete side surface. That is, the depth of the functional groove 11 on the side wall of the magnetic core 1 matches the thickness of the heat sink 4. After the heat sink 4 is embedded, its outer surface is perfectly connected with the original magnetic core side wall surface around the functional groove 11, without any height difference. This flush structure can be achieved through a precise one-piece molding process. For example, when the magnetic core powder is pressed and molded, the part of the mold used to form the functional groove 11 is provided with protrusions or modules that can precisely control the depth. After the pre-made heat sink 4 is placed in this position, powder is filled and pressed. By precisely controlling the powder filling amount, pressing pressure and mold closing accuracy, after pressing and sintering, the back of the heat sink 4 is in close contact with the bottom of the groove, while the front is just flush with the side wall forming surface of the mold cavity, thereby obtaining an outer surface that is completely flush with the side wall of the magnetic core.

[0075] Therefore, the outer surface of the heat sink 4 is flush with the side wall of the magnetic core, which means that its entire exposed area can effectively exchange heat with the surrounding air or external cooling environment without losing effective heat dissipation area due to protrusions or depressions. At the same time, this design maintains the regularity and compactness of the device's outline and will not increase the overall width of the device or create protrusions due to the addition of the heat sink, which is conducive to achieving high-density installation in a compact circuit layout.

[0076] In one possible implementation of this application, the heat sink 4 includes a first heat sink 41 and a second heat sink 42 disposed at both ends of the first heat sink 41. The first heat sink 41 is fitted into the functional slot 11 on the side wall of the magnetic core 1, and the second heat sink 42 is fitted into the functional slot 11 at both ends of the magnetic core 1.

[0077] Therefore, the heat dissipation function of the heat sink 4 on the side and end face of the magnetic core 1 is divided into zones. The second heat sink 42 is used to fit the end face of the magnetic core 1 without gaps, realizing the efficient "extraction" of heat inside the magnetic core 1. The first heat sink 41 mainly undertakes the function of "diffusion" of heat in the side and "dissipation" to the outside, and connects the two ends to achieve thermal balance. This division of labor allows each part of the structure to be optimized for its core function. The first heat sink 41 acts as a connecting beam, physically and thermally connecting the two second heat sinks 42 into an integral frame, which is arranged around the coil 2 to match the heat dissipation requirements. This not only significantly enhances the mechanical strength of the heat dissipation structure itself, but more importantly, it also improves the heat dissipation efficiency of the two coils. A low-thermal-resistance transverse thermal channel is established between the main end-face heat dissipation areas. This is an efficient and short-path heat conduction channel from the internal heat source (coil 2 and magnetic core 1) to the external heat dissipation coil 2 → magnetic core 1 → heat sink 4. This improves the long and high-resistance heat conduction path (which contains multiple different materials, forming a series of multi-layer thermal resistance) in related technologies, such as coil → magnetic core → cladding layer → thermally conductive adhesive / air gap → heat sink. It completely eliminates the two high-thermal-resistance links of "cladding layer" and "interface medium (adhesive / air) between heat sink and cladding layer" that exist in traditional structures. It can also quickly balance the temperature difference at both ends of magnetic core 1, avoid local overheating, and improve the overall heat dissipation uniformity and efficiency.

[0078] Based on the aforementioned "magnetic device with a multi-segment composite heat dissipation structure," this embodiment further optimizes the specific interface shape of its second heat dissipation section 42. Specifically, the side of the second heat dissipation section 42 facing the magnetic core 1 maintains a preset tilt angle with the end face of the magnetic core 1 (as shown in Figure Q). This preset tilt angle design results in a "sloping contact" with a larger surface area between the second heat dissipation section 42 and the end face of the magnetic core 1. This directly increases the heat conduction interface area from the end face of the magnetic core 1 to the second heat dissipation section 42, helping to reduce interface thermal resistance and improve the extraction of heat from the magnetic core core. The efficiency of "taking" is improved, and the preset tilt angle gives the connection between the heat sink 4 and the magnetic core 1 a certain degree of wedge-shaped or dovetail-shaped mechanical interlocking effect, which can more firmly "lock" the second heat sink 42 into the functional slot 11 of the magnetic core 1, significantly improving the mechanical strength and long-term reliability of the combination of the two, resisting the loosening that may be caused by thermal cycling. At the same time, during the integral pressing and molding process of the magnetic core 1, the tilted slope of the second heat sink 42 can play a guiding role, which is conducive to the magnetic powder filling all corners between the heat sink 4 and the functional slot 11 more smoothly, reducing molding defects and ensuring the tightness of the interface contact.

[0079] Of course, the design of the preset tilt angle can be used in conjunction with the features in the aforementioned embodiments regarding the gradual change in thickness of the heat sink 4, the ratio of projected area, and the thickness ratio. For example, the second heat sink 42 itself can be designed to have a gradually increasing thickness, while its contact surface with the functional slot 11 has an tilt angle, thereby optimizing the heat dissipation interface in multiple dimensions.

[0080] In one example, the side of the first heat dissipation part 41 facing away from the magnetic core 1 is on the same plane as the sidewall of the magnetic core 1. That is, after the first heat dissipation part 41 is fitted into the functional slot 11 of the sidewall of the magnetic core 1, its side facing away from the magnetic core 1 (i.e., the exposed surface) is on the same plane as the outer surface of the sidewall of the magnetic core 1. This makes the side of the device appear as a complete, continuous, and smooth plane, making it impossible to directly distinguish the boundary between the heat dissipation body and the magnetic core from the appearance. Simultaneously, the side of the second heat dissipation part 42 facing away from the magnetic core 1 is on the same plane as the end face of the magnetic core 1. That is, the second heat dissipation parts 42 located at both ends of the magnetic core 1, after being fitted into the functional slot 11 at the corresponding ends, have their side facing away from the magnetic core 1 (i.e., the exposed surface) on the same plane as the end face of the magnetic core 1, making the end face of the device also appear as a complete, continuous, and smooth plane. Therefore, the heat sink 4 can be considered to be completely flush with and embedded within the outline of the magnetic core 1, without increasing the overall external dimensions (length, width, and height) of the device. This achieves the integration of an efficient heat dissipation structure in an extremely compact space, which is very beneficial for achieving high-density layout and installation in circuit modules that pursue high power density. Furthermore, the entire exposed surface of the first heat sink 41 and the second heat sink 42 becomes an effective heat dissipation surface. Since it is flush with the surface of the magnetic core 1, its entire area can directly exchange heat with the surrounding environment or form a large-area, low-thermal-resistance contact with external heat dissipation systems (such as heat sinks or cold plates) without any area loss. At the same time, this flush structure eliminates all external protrusions and edges, greatly reducing the risk of damage or displacement of the heat sink due to bumps or scratches during transportation, assembly, or use.

[0081] In one example, to optimize the spatial layout between the heat sinks 4 at both ends of the magnetic core 1, on the end face of the magnetic core 1 away from the end electrode 3, the ends of the two second heat sinks 42 away from the first heat sink 41 are spaced apart. This means that the two second heat sinks 42 are independent and not directly connected on this end face. Under this design, the two second heat sinks 42 can be independently embedded in the corresponding functional slots 11 on this end face. They can have the aforementioned preset tilt angle or be flush with the end face of the magnetic core 1. The spaced-apart structure separates the two heat sink areas in the center area of ​​the end face, thereby avoiding excessive functional slots 11 on the end face of the magnetic core 1, improving the overall cost-effectiveness of the device, and reducing unnecessary heat sink material usage while ensuring effective heat dissipation area, which helps to miniaturize and lighten the device.

[0082] Preferably, this spacing distance is the same as the spacing distance between adjacent coils 2 within the magnetic core 1, thereby achieving spatial matching between the external heat dissipation structure and the internal heat source distribution. This allows the area with the most concentrated heat generation (between coil turns) to obtain a more direct and unobstructed heat dissipation path from above, which is beneficial for heat to be conducted more efficiently to the heat sink 4 above after it is generated from the heat source. This reduces the lateral diffusion distance and heat accumulation of heat inside the magnetic core 1. Furthermore, this layout helps to guide heat flow, making the temperature distribution on the magnetic core 1 and the heat sink 4 more uniform, avoiding local overheating hot spots, thereby improving the overall heat dissipation balance and reliability of the device.

[0083] Unlike the aforementioned embodiment with spaced-apart second heat dissipation sections 42, such as Figure 3 As shown, on the end face of the electrode 3 away from the magnetic core 1, the ends of the two second heat dissipation parts 42 away from the first heat dissipation part 41 are connected as one unit, thus forming an integrated heat dissipation structure. The connection of the two second heat dissipation parts 42 as one unit significantly improves the rigidity of the heat dissipation structure itself and the overall structural strength after being combined with the functional slot 11 of the magnetic core 1. It can better resist deformation or displacement that may be caused by external force or thermal stress, and the device has higher reliability. Moreover, as an integrated heat dissipation structure of a single part, there is no need to align and fix the two independent heat dissipation bodies 4 separately during assembly, which simplifies the assembly steps and helps to ensure the positional accuracy and symmetry of the two heat dissipation bodies 4 relative to the magnetic core 1, thereby improving product consistency and yield.

[0084] In one example, the magnetic device has a heat dissipation structure design with different sidewall coverage areas. On the one hand, on both sides of the magnetic core 1, the first heat dissipation part 41 partially covers the sidewall of the magnetic core 1. That is, the first heat dissipation part 41 embedded in the functional slots 11 on both sides of the magnetic core 1 only covers a part of the sidewall of the magnetic core 1, while the area of ​​the sidewall near the front end and / or rear end of the magnetic core 1 is not directly covered by the heat dissipation body 4. These areas are still the magnetic core body material. This design optimizes material cost and weight while ensuring the heat dissipation performance of the core heat-generating area.

[0085] Or such as Figure 4 As shown, on both sides of the magnetic core 1, the first heat dissipation part 41 completely covers the sidewall of the magnetic core 1. In this embodiment, the first heat dissipation part 41, which is embedded in the functional slots 11 on both sides of the magnetic core 1, completely covers the entire sidewall of the magnetic core 1. That is, the first heat dissipation part 41 extends continuously from near the front end of the magnetic core 1 to cover the rear end of the magnetic core 1. This design realizes the maximum possible contact area between the heat dissipation body 4 and the magnetic core 1 in the sidewall direction, and establishes the most direct and continuous heat conduction path from the entire surface of the sidewall of the magnetic core 1 to the external environment to ensure optimal heat dissipation capacity.

[0086] In one example, on the end face of the magnetic core 1 away from the end electrode 3, the cross-sectional profiles (i.e., the shapes observed in a cross-section parallel to the end face) of the two second heat dissipation portions 42 gradually expand towards each other in a face-to-face direction. In other words, the cross-sectional dimensions (width or thickness) of each second heat dissipation portion 42 on the side near the centerline of the magnetic core 1 or near the other second heat dissipation portion 42 are larger than the outer portion away from the center of the magnetic core 1, thereby forming a wedge-shaped, trapezoidal, or wing-like profile. This "gradually expanding" profile design can be combined with any of the aforementioned embodiments. For example, the second heat dissipation portion 42 can simultaneously have a preset tilt angle facing the end face of the magnetic core 1, while its cross-section presents this gradually expanding shape. The two optimize the heat dissipation interface together from different spatial dimensions.

[0087] The portion of the second heat dissipation section 42 that gradually expands towards the center can form a larger area of ​​close contact with the magnetic core 1 on the side wall and bottom of the functional slot 11. This directly increases the heat conduction area from the magnetic core 1 to the heat sink 4. At the same time, the gradually expanding contour helps to guide and diffuse the heat generated by the coil 2 inside the magnetic core 1 more smoothly to the wider cross section of the heat sink 4, reducing the heat flow congestion effect, helping to reduce the temperature rise gradient of the heat sink 4 itself, improving the overall heat dissipation uniformity, and the gradually expanding shape can form a certain mechanical interlock, which helps to resist the risk of the heat sink 4 loosening from the functional slot 11 of the magnetic core 1 when subjected to thermal stress or vibration, thus improving the long-term reliability of the structure.

[0088] Continue to refer to Figure 5 This application discloses a method for fabricating a magnetic device, comprising: S101, magnetic powder and coil 2 are pressed together to form a magnetic core 1 that wraps the coil 2.

[0089] In this step, a predetermined amount of magnetic powder (such as iron-silicon-aluminum, iron-nickel alloy powder, etc.) and the pre-wound coil 2 are placed together in a molding mold for the first molding. This pressing is to densify the magnetic powder and form a preliminary blank of the magnetic core 1. The blank has wrapped the coil 2 inside, and the two ends of the coil 2 are positioned and exposed at the predetermined end face positions of the blank.

[0090] Preferably, the initial blank of the magnetic core 1 formed in the first molding has a pre-shaped functional groove 11 formed on its outer surface, and the functional groove 11 is arranged around the coil 2.

[0091] S102, Assemble the heat sink 4 to the magnetic core 1, and fill the magnetic core 1 with magnetic powder and perform secondary pressing so that the side of the heat sink 4 facing the magnetic core 1 is embedded in the magnetic core 1 and fits against the magnetic core 1.

[0092] In this step, the heat sink 4 can be initially assembled with the functional slot 11 of the magnetic core 1. Then, magnetic powder is added to the magnetic core 1 blank on which the heat sink 4 has been placed, ensuring that the gap around the heat sink 4 and the gap between it and the functional slot 11 is filled with powder. Then, a second molding is performed. This molding is carried out under higher pressure or a more optimized pressure curve, which makes the added magnetic powder and the original blank more compact and forces the powder to tightly wrap the heat sink 4, eliminating the air gap between it and the magnetic core 1 or the slot wall of the functional slot 11, thereby achieving a tight fit between the heat sink 4 and the magnetic core 1.

[0093] The heat sink 4 and the magnetic powder material of the magnetic core 1 are integrally pressed and formed, which makes the heat sink 4 and the magnetic core 1 or the functional groove 11 of the magnetic core 1 in direct contact without gaps. Then the magnetic powder and the surface of the heat sink 4 form an extremely tight contact at the microscopic level, and even under certain conditions, limited diffusion occurs at the interface, forming a strong mechanical interlock and micro-metallurgical bond. This ensures a huge effective contact area and extremely low interfacial contact thermal resistance.

[0094] S103, Annealing is performed on the magnetic core 1 after secondary pressing.

[0095] In this step, the integral blank after secondary pressing is placed in a sintering furnace for annealing treatment. The purpose is to eliminate the internal stress generated during the pressing process and to create a metallurgical bond between the magnetic powder particles through high-temperature sintering, so as to endow the magnetic core 1 with the final required magnetic properties (such as high permeability and low loss) and mechanical strength.

[0096] S104, the surface of the annealed magnetic core 1 is ground to remove residual magnetic powder and expose the heat sink 4 and the end electrode 3. The end electrode 3 is the part of the end of the coil 2 exposed on the outer surface of the magnetic core 1, and the two ends of the heat sink 4 respectively at least partially cover one end of the magnetic core 1 with the end electrode 3 and the other end opposite to the end electrode 3.

[0097] In this step, the magnetic core 1 after annealing and cooling is subjected to precision surface grinding. The main purpose is to remove the burrs or excess magnetic powder that may remain on the surface of the magnetic core 1 (especially the end face and side face) due to secondary pressing, to accurately control the final external dimensions of the magnetic core 1, and to expose the design surface of the heat sink 4 and the end of the coil 2 by grinding. After grinding, the outer surface of the heat sink 4 is exposed, and the end of the coil 2 is clearly exposed on the designated end face of the magnetic core 1. This exposed part will serve as the base of the end electrode 3. At this time, the heat sink 4 is firmly connected to both sides of the magnetic core 1, and its two ends at least partially cover the end of the magnetic core 1 with the end electrode 3 and the opposite end.

[0098] S105, the polished magnetic core 1 is coated, and laser peeling and electroplating are performed on the exposed heat sink 4 and end electrode 3 areas.

[0099] In this step, the polished magnetic core 1 is completely coated, for example by spraying or dipping a thin and dense layer of insulating varnish (such as epoxy resin) to provide necessary electrical insulation and environmental protection. Subsequently, using laser stripping technology, the insulating varnish covering the areas requiring electrical connection (i.e., the exposed ends of coil 2—the future end electrode 3 area) and the outer surface area of ​​the heat sink 4 is precisely removed. Through an electroplating process (such as nickel plating followed by tin plating), a metal layer is deposited in the laser-cleaned area to form a firmly attached and solderable end electrode 3, and an anti-oxidation or solderable coating is formed on the outer surface of the heat sink 4.

[0100] The magnetic device fabrication method of this application, through the process of "preliminary pressing - heat sink placement - secondary pressing", efficiently solves the manufacturing problem of low thermal resistance and high strength bonding between heat sink 4 and magnetic core 1. Secondary pressing ensures the minimization of interface gap and the maximization of contact area, eliminating the high thermal resistance layer caused by traditional adhesive or assembly methods from the manufacturing source. Combined with subsequent annealing, precision grinding and selective electroplating, this method can stably and reliably produce magnetic devices with the excellent heat dissipation structure and electrical performance described in the aforementioned embodiments, providing a practical and feasible process solution for the large-scale manufacturing of next-generation high-power and high-reliability inductors suitable for high-end AI servers, communication equipment and other fields.

[0101] The magnetic device fabricated using this method has a dense, integrally formed core 1. The coil 2 can be encapsulated inside the core 1 during its fabrication process. The heat sink 4 at least partially covers one end of the core 1 with the end electrode 3 and the other end opposite to the end electrode 3, ensuring a strong connection between the heat sink 4 and the core 1. This also matches the area occupied by the coil 2 inside the core 1. The heat sink 4 is in direct contact with the core 1 inside the core 1, thus constructing an efficient, short-path heat conduction channel from the internal heat source (coil 2 and core 1) to the external heat dissipation: coil 2 → core 1 → heat sink 4. This improves upon the long and high-resistance heat conduction path (which involves multiple materials forming a series of multi-layered thermal resistance) in related technologies, such as coil → core → coating layer → thermally conductive adhesive / air gap → heat sink. This completely eliminates the two high-thermal-resistance links in the traditional structure: the "coating layer" and the "interface medium (adhesive / air) between the heat sink and the coating layer."

[0102] This application also discloses an electronic device, including a magnetic device as described in any of the above embodiments. For other working principles and processes of the electronic device in this embodiment, please refer to the description of the magnetic device in the above embodiment, which will not be repeated here.

[0103] The magnetic devices, their fabrication methods, and electronic devices provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. It should be noted that the descriptions of each embodiment in this application have different emphases; parts not described in detail or in a particular embodiment can be referred to in the relevant descriptions of other embodiments.

[0104] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. The technical features of the technical solution of this application can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are also included within the patent protection scope of this application, as long as the combination of these technical features does not contradict each other.

[0105] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for the purpose of helping to understand the core ideas of the present application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present application. Therefore, the content of this specification should not be construed as a limitation of the present application.

Claims

1. A magnetic device, characterized by, The application relates to a magnetic core (1) integrally formed, a coil (2) arranged in the magnetic core (1) and the end of the coil (2) exposed to the outer surface of the magnetic core (1) as an end electrode (3) of the magnetic device, and a heat sink (4) arranged on the magnetic core (1) and covering at least partially the one end of the magnetic core (1) with the end electrode (3) and the other end of the magnetic core (1) opposite to the end electrode (3), and the heat sink (4) embedded in the magnetic core (1) and adhered to the magnetic core (1) on the side facing the magnetic core (1). The outer surface of the magnetic core (1) is provided with a functional groove (11) surrounding the coil (2), and the heat sink (4) is connected in the functional groove (11). The part of the heat sink (4) on the one end of the magnetic core (1) with the end electrode (3) and the other end of the magnetic core (1) opposite to the end electrode (3) has a preset angle with the end surface of the magnetic core (1) on the side facing the magnetic core (1). The part of the heat sink (4) on the one end of the magnetic core (1) with the end electrode (3) and the other end of the magnetic core (1) opposite to the end electrode (3) is in the same plane with the end surface of the magnetic core (1).

2. The magnetic device of claim 1, wherein, The two heat sinks (4) on the one end of the magnetic core (1) with the end electrode (3) and the other end of the magnetic core (1) opposite to the end electrode (3) have a spacing or are connected as a whole.

3. The magnetic device of claim 1, wherein, The heat sink (4) covers at least partially the side wall of the magnetic core (1) on both sides of the magnetic core (1).

4. The magnetic device of claim 1, wherein, The extension direction of the two ends of the coil (2) on the magnetic core (1) is the same as the length direction of the heat sink (4) along the side wall of the magnetic core (1).

5. The magnetic device of claim 1, wherein, The heat sink (4) is integrally pressed with the magnetic powder material of the magnetic core (1).

6. The magnetic device of claim 1, wherein, The connection gap between the heat sink (4) in the functional groove (11) and the functional groove (11) is less than a preset gap value.

7. The magnetic device of claim 1, wherein, In the vertical projection of the first direction, the functional groove (11) and the heat sink (4) cover the coil (2), the first direction is the extension direction of the upper / lower end of the magnetic core (1), the coil (2) is arranged in the magnetic core (1) with a spacing, and the coil (2) is arranged in the magnetic core (1) in the second direction, wherein the second direction is perpendicular to the first direction.

8. The magnetic device of claim 1, wherein, The thickness of the two heat sinks (4) on the one end of the magnetic core (1) with the end electrode (3) and the other end of the magnetic core (1) opposite to the end electrode (3) is gradually increased in the third direction, wherein the third direction is perpendicular to the first direction and the second direction.

9. The magnetic device of claim 2, wherein, ​ 10. The magnetic device of claim 2, wherein, ​ 11. The magnetic device of claim 10, wherein, ​ 12. The magnetic device of claim 2, wherein, The heat sink (4) comprises a first heat dissipation part (41) and a second heat dissipation part (42) arranged at both ends of the first heat dissipation part (41), the first heat dissipation part (41) is embedded in the functional groove (11) of the side wall of the magnetic core (1), and the second heat dissipation part (42) is embedded in the functional groove (11) at both ends of the magnetic core (1), and the side of the second heat dissipation part (42) facing the magnetic core (1) has a preset inclination angle with the end face of the magnetic core (1).

13. The magnetic device of claim 12, wherein, The side of the first heat dissipation part (41) away from the magnetic core (1) is in the same plane as the side wall of the magnetic core (1), and the side of the second heat dissipation part (42) away from the magnetic core (1) is in the same plane as the end face of the magnetic core (1).

14. A method of fabricating a magnetic device, the method comprising: Comprising: The magnetic powder is co-pressed with the coil (2) to form a magnetic core (1) that wraps the coil (2); The heat sink (4) is assembled to the magnetic core (1), and the magnetic core (1) with the heat sink (4) is filled with the magnetic powder and subjected to secondary pressing, so that the side of the heat sink (4) facing the magnetic core (1) is embedded in the magnetic core (1) and adheres to the magnetic core (1); The magnetic core (1) after secondary pressing is subjected to annealing treatment; The surface of the magnetic core (1) after annealing is ground to remove residual magnetic powder and expose the heat sink (4) and end electrode (3), the end electrode (3) is the part of the end of the coil (2) exposed on the outer surface of the magnetic core (1), and the two ends of the heat sink (4) at least partially cover one end of the magnetic core (1) with the end electrode (3) and the other end opposite to the end electrode (3); The magnetic core (1) after grinding is subjected to coating treatment, and laser paint stripping and electroplating are performed on the exposed heat sink (4) and end electrode (3) area.

15. An electronic device, comprising: The magnetic device of any one of claims 1 to 14. The magnetic device of any one of claims 1 to 14.

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