A closed magnetic circuit inductor with a metal film

Abstract

The utility model provides a kind of closed magnetic circuit inductor with metal film, belong to inductor technical field.The inductor includes inductor body, inductor body includes magnetic core body and shell, magnetic core body is set to closed magnetic loop structure, shell is set at the periphery of magnetic core body.The surface of shell is formed by physical vapor deposition process Metal film layer.The inductor can improve heat dissipation capacity by metal film layer, can take into account the heat dissipation efficiency and magnetic property stability of inductor, help to improve the service life of inductor.

Description

Technical Field

[0001] This utility model relates to the field of inductor technology, and in particular to a closed magnetic circuit inductor with a metal thin film. Background Technology

[0002] Inductors, as core components for energy storage, filtering, and power conversion, are widely used in various electronic systems such as power adapters, new energy vehicle inverters, industrial control power supplies, and server power supplies. With the development of electronic devices towards higher frequencies, smaller sizes, and higher currents, the operating environment of inductors is becoming increasingly harsh. During operation, the heat generated by coil resistance losses, core hysteresis losses, and eddy current losses increases significantly, leading to a rise in their temperature. This temperature increase causes inductor inductance drift and reduced energy conversion efficiency; furthermore, prolonged high-temperature environments accelerate the thermal aging of the core material and the deterioration of the coil insulation, significantly shortening the inductor's lifespan and even causing system failures. Therefore, effectively solving the heat dissipation problem of inductors and improving their thermal stability and lifespan has become a pressing technical challenge in this field.

[0003] To ensure magnetic shielding performance, the casing of closed magnetic circuit inductors is usually designed to be more enclosed than that of open magnetic circuit inductors. Traditional inductors rely on the heat dissipation method of the inductor casing material or external fins, which is difficult to effectively overcome the thermal resistance limitation of the closed structure of the inductor, and heat will still accumulate.

[0004] Therefore, it is necessary to improve the structure of existing closed magnetic circuit inductors to overcome the shortcomings of the existing technology. Utility Model Content

[0005] To overcome the problems existing in related technologies, one of the objectives of this utility model is to provide a closed magnetic circuit inductor with a metal thin film. This inductor can improve heat dissipation capacity through the metal thin film layer, and can balance the heat dissipation efficiency and magnetic performance stability of the inductor, which helps to improve the service life of the inductor.

[0006] A closed magnetic circuit inductor with a metal thin film, comprising:

[0007] An inductor body, comprising a magnetic core and a housing, wherein the magnetic core is configured as a closed magnetic circuit structure and the housing is disposed around the magnetic core;

[0008] The surface of the outer shell is formed by a metal thin film layer through a physical vapor deposition process.

[0009] In a preferred embodiment of this invention, the thickness t of the metal thin film layer is 10nm-500nm.

[0010] In a preferred embodiment of this invention, the metal thin film layer covers part or all of the outer shell.

[0011] In a preferred embodiment of this invention, the metal thin film layer is arranged in multiple strips on the surface of the outer shell, with each strip of the metal thin film layer spaced apart by a distance G; wherein G≥3t.

[0012] In a preferred embodiment of this invention, the metal thin film layer is distributed in a grid pattern on the surface of the outer shell, wherein the grid aperture d is 0.5-3 mm.

[0013] In a preferred embodiment of this invention, the outer shell includes a housing and a heat-conducting structure disposed within the housing. The heat-conducting structure includes a plurality of heat-conducting pipes disposed within the housing. Each heat-conducting pipe is provided with a heat-absorbing end and a heat-dissipating end. The heat-absorbing end is disposed on the inner wall of the housing, and the heat-dissipating end is disposed on the outer wall of the housing.

[0014] In a preferred embodiment of this invention, a metal base layer is further provided on the outer wall of the housing, one side of the metal base layer is connected to the heat dissipation end of the heat pipe, and the metal thin film layer is sputtered on the metal base layer.

[0015] In a preferred embodiment of this invention, the magnetic core body is a ring or EE structure.

[0016] The beneficial effects of this utility model are as follows:

[0017] This invention provides a closed magnetic circuit inductor with a metal thin film. The inductor includes an inductor body, which comprises a magnetic core and a housing. The magnetic core is configured as a closed magnetic circuit structure, and the housing is disposed around the periphery of the magnetic core. The surface of the housing is formed with a metal thin film layer through physical vapor deposition. During the manufacturing process, a continuous metal thin film layer can be formed on the front and four sides of the housing by magnetron sputtering. Sputtering ensures a tight thermally conductive contact between the film and the housing surface, and the film layer uniformly covers the housing surface without obvious pinholes or peeling. The copper metal thin film layer, by continuously covering the front and four sides of the housing, forms an efficient heat conduction path, which can improve the heat dissipation capacity of the capacitor, effectively reduce the decrease in permeability of the ferrite core due to high temperature, and significantly alleviate the thermal degradation of magnetic properties. The improved heat dissipation capacity reduces the operating temperature of the magnetic core and coil insulation layer, which can extend the service life of the capacitor and provide higher operating stability. Attached Figure Description

[0018] Figure 1 This is a perspective view of a closed magnetic circuit inductor with a metal thin film provided in an embodiment of this utility model;

[0019] Figure 2This is a schematic diagram of the magnetic core body provided in an embodiment of the present invention being disposed in the outer casing;

[0020] Figure 3 This is a schematic diagram showing the heat pipe provided in an embodiment of the present invention being installed in the outer casing;

[0021] Figure 4 This is a schematic diagram of the metal thin film layer provided in Embodiment 2 of this utility model being disposed on the outer shell;

[0022] Figure 5 This is a schematic diagram of the metal thin film layer provided in Embodiment 3 of this utility model being disposed on the outer shell.

[0023] Figure label:

[0024] 1. Outer shell; 11. Heat pipe; 111. Heat absorption end; 112. Heat dissipation end; 2. Metal thin film layer; 3. Magnetic core body; 4. Metal base layer. Detailed Implementation

[0025] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0026] Inductors, as core components for energy storage, filtering, and power conversion, are widely used in various electronic systems such as power adapters, new energy vehicle inverters, industrial control power supplies, and server power supplies. With the development of electronic devices towards higher frequencies, smaller sizes, and higher currents, the operating environment of inductors is becoming increasingly harsh. During operation, the heat generated by coil resistance losses, core hysteresis losses, and eddy current losses increases significantly, leading to a rise in their temperature. This temperature increase causes inductor inductance drift and reduced energy conversion efficiency; furthermore, prolonged high-temperature environments accelerate the thermal aging of the core material and the deterioration of the coil insulation, significantly shortening the inductor's lifespan and even causing system failures. Therefore, effectively solving the heat dissipation problem of inductors and improving their thermal stability and lifespan has become a pressing technical challenge in this field.

[0027] To ensure magnetic shielding performance, the casing of closed magnetic circuit inductors is usually designed to be more enclosed than that of open magnetic circuit inductors. Traditional open magnetic circuit inductors rely on the heat dissipation methods of the inductor casing material or external fins, which are difficult to effectively overcome the thermal resistance limitation of the closed structure of the inductor, and heat will still accumulate.

[0028] Based on this, this application provides a closed magnetic circuit inductor with a metal thin film.

[0029] Example 1

[0030] like Figures 1-3 As shown, this embodiment provides a closed magnetic circuit inductor with a metal thin film, comprising:

[0031] The inductor body includes a magnetic core body 3 and a housing 1. The magnetic core body 3 is configured as a closed magnetic circuit structure, and the housing 1 is disposed around the magnetic core body 3.

[0032] The surface of the outer shell 1 is formed by a metal thin film layer 2 through a physical vapor deposition process.

[0033] Specifically, the magnetic core body 3 has a ring-shaped or EE structure. This ring-shaped or EE structure allows the magnetic core body 3 to form a closed magnetic circuit, concentrating the magnetic flux primarily within the core and reducing leakage to the external space. This characteristic prevents the metal thin film layer 2 from being exposed to a strong alternating magnetic field, thus avoiding significant eddy current losses and ensuring that the inductor's electrical efficiency remains unaffected.

[0034] More specifically, the outer shell 1 is injection molded from a modified epoxy resin composite material and covers the periphery of the magnetic core body 3. The outer shell 1 has a thickness of 1.2 mm, and the front and four sides are pretreated with plasma to enhance surface activity. Additionally, 5% alumina thermally conductive filler can be added to the modified epoxy resin composite material to improve the heat dissipation capacity of the outer shell 1.

[0035] In one embodiment, a metal thin film layer 2 can be formed on the outer casing 1 by vapor deposition, as follows:

[0036] Aluminum with a purity of 99.99% was selected as the vapor deposition source, and the pretreated outer shell 1 was fixed on the sample holder of the vacuum vapor deposition machine.

[0037] Close the vacuum chamber and evacuate to a vacuum level of 1×10⁻⁶. -4 Pa, heating the evaporation source to the evaporation temperature of aluminum (approximately 660°C), and controlling the evaporation rate to 0.5 nm / s;

[0038] During the vapor deposition process, the temperature of the outer shell 1 is kept at 50°C. The film thickness is monitored in real time by a quartz crystal monitor. When the thickness reaches 100 nanometers, the vapor deposition is stopped and the shell is taken out after naturally cooling to room temperature. At this time, a continuous aluminum metal film layer 2 is formed on the front and four sides of the outer shell 1. The film is tightly attached to the surface of the outer shell 1, forming a good thermally conductive contact.

[0039] In another embodiment, a metal thin film layer 2 can be formed on the outer casing 1 by sputtering, as follows:

[0040] Copper with a purity of 99.95% was selected as the sputtering target. The pretreated shell 1 was fixed on the sample stage of the magnetron sputtering equipment, and the distance between the target and the sample stage was 15cm.

[0041] Vacuum up to 5×10 -5 After Pa, argon gas (99.999% purity) is introduced as the working gas to control the pressure in the vacuum chamber to 0.5 Pa;

[0042] An RF power supply (150W) is applied to ionize argon gas and form plasma, which bombards the surface of the copper target, causing copper atoms to detach from the target and deposit on the front and four sides of the outer shell 1.

[0043] Control the sputtering time to achieve a copper thin film thickness of 300 nanometers. After sputtering is complete, turn off the power and wait for the vacuum chamber to return to normal pressure before removing the film. At this point, the copper thin film uniformly covers the surface of the outer shell 1 without any obvious pinholes or peeling.

[0044] The aforementioned closed-circuit inductor with a metal thin film includes an inductor body comprising a magnetic core 3 and a housing 1. The magnetic core 3 is configured as a closed magnetic circuit structure, and the housing 1 is disposed around the magnetic core 3. A metal thin film layer 2 is formed on the surface of the housing 1 using a physical vapor deposition process. During the manufacturing process, the metal thin film layer 2 can be formed on the front and four sides of the housing 1 by magnetron sputtering. Sputtering ensures a tight thermally conductive contact between the film and the surface of the housing 1, and the film layer uniformly covers the surface of the housing 1 without obvious pinholes or peeling. The copper metal thin film layer 2, by continuously covering the front and four sides of the housing 1, forms an efficient heat conduction path, which can improve the heat dissipation capacity of the capacitor, effectively reduce the decrease in permeability of the ferrite core due to high temperature, and significantly alleviate the thermal degradation of magnetic properties. The improved heat dissipation capacity reduces the operating temperature of the magnetic core and coil insulation layer, which can extend the service life of the capacitor and provide higher operating stability. In addition, the metal thin film layer 2 also has an EMI shielding function.

[0045] In a specific embodiment, the thickness t of the metal thin film layer 2 is 10nm-500nm.

[0046] Furthermore, the metal thin film layer 2 covers part or all of the outer shell 1.

[0047] The thickness of the metal thin film layer 2 is controlled within the range of 10nm-500nm. This allows for effective heat dissipation from the magnetic core by utilizing the high thermal conductivity of metals such as aluminum, copper, and silver, significantly improving the heat dissipation efficiency of the package and reducing the thermal degradation of magnetic properties caused by high temperatures. Furthermore, because the magnetic flux in the closed magnetic circuit structure is concentrated inside the magnetic core, this thickness of metal thin film does not generate significant eddy current losses, avoiding adverse effects on the electrical efficiency of the inductor, thus balancing heat dissipation efficiency and magnetic performance stability. The metal thin film layer 2 can cover part or all of the outer shell 1, flexibly adapting to the heat dissipation requirements of different scenarios—full coverage maximizes the heat dissipation area and heat conduction path, suitable for high-frequency, high-current, and other high-heat-load scenarios; partial coverage reduces the amount of metal material used while meeting basic heat dissipation requirements, lowering process costs and improving the practicality and economy of the solution.

[0048] In a preferred embodiment, the outer casing 1 includes a housing and a heat-conducting structure disposed within the housing. The heat-conducting structure includes a plurality of heat-conducting pipes 11 disposed within the outer casing 1. Each heat-conducting pipe 11 is provided with a heat-absorbing end 111 and a heat-dissipating end 112. The heat-absorbing end 111 is disposed on the inner wall of the housing, and the heat-dissipating end 112 is disposed on the outer wall of the housing. Furthermore, a metal base layer 4 is also disposed on the outer wall of the housing. One side of the metal base layer 4 is connected to the heat-dissipating end 112 of the heat-conducting pipe 11, and the metal thin film layer 2 is sputtered onto the metal base layer 4.

[0049] In this embodiment, the heat pipe 11 is made of copper and distributed within the housing. The heat-absorbing end 111 of the heat pipe 11 is tightly attached to the inner wall of the housing (corresponding to the concentrated heat generation area of ​​the magnetic core) via thermally conductive silicone (thermal conductivity 3.0 W / (m·K)), while the heat-dissipating end 112 extends out of the outer wall of the housing and is flush with it. The heat pipe 11, through its heat-absorbing end 111, directly contacts the inner wall of the housing (the concentrated heat generation area of ​​the magnetic core), allowing for rapid heat transfer from the magnetic core to the heat-dissipating end 112 extending out of the housing. The metal substrate 4 (aluminum foil) is tightly connected to the heat-dissipating end 112, which expands the heat diffusion area and provides a continuous thermally conductive base for the metal thin film layer 2, enabling a highly efficient heat conduction path through "magnetic core → housing → heat pipe 11 → metal substrate 4 → metal thin film layer 2". Compared to a structure containing only the metal thin film layer 2, this embodiment effectively improves heat dissipation efficiency.

[0050] Example 2

[0051] This embodiment is an improvement on embodiment 1.

[0052] like Figures 1-4 As shown, specifically, the metal thin film layer 2 is arranged in multiple strips on the surface of the outer shell 1, and each metal thin film layer 2 is arranged at a interval G; where G≥3t.

[0053] In this embodiment, the strip-shaped metal thin film layers 2 can still dissipate the heat generated by the magnetic core through multiple independent heat conduction paths, maintaining the heat dissipation capacity of the core heat-generating area of ​​the closed magnetic circuit inductor. The spacing G≥3t reduces the total amount of metal materials (such as aluminum, copper, and silver), lowering material costs. It also reduces the processing area for evaporation / sputtering processes, reducing production energy consumption and process costs. Furthermore, the spacing G≥3t (t being the film thickness) prevents electromagnetic coupling between adjacent strip-shaped metal thin film layers 2 due to excessive proximity, preventing the formation of additional parasitic capacitances or eddy current channels and avoiding interference with the original magnetic properties and electrical efficiency of the closed magnetic circuit inductor.

[0054] Example 3

[0055] This embodiment is an improvement on embodiment 1.

[0056] like Figures 1-5 As shown, unlike Example 2, the metal thin film layer 2 is distributed in a grid pattern on the surface of the outer shell 1, wherein the grid aperture d is 0.5-3mm.

[0057] In this embodiment, the mesh structure forms a multi-path heat conduction network through crisscrossing metal thin films. The 0.5-3mm aperture design ensures that the heat dissipation area remains within a reasonable range, effectively dissipating the heat generated by the magnetic core and preventing excessive heat accumulation within the closed magnetic circuit structure. Simultaneously, the presence of mesh gaps reduces the total amount of metal materials (such as aluminum, copper, and silver) used. Furthermore, the mesh gaps reduce potential eddy current risks, ensuring that the electrical efficiency and magnetic performance of the inductor remain unaffected.

[0058] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings. In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms 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 the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0059] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0060] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. The above description is only a preferred embodiment of this utility model and is not intended to limit this utility model. For those skilled in the art, this utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A closed magnetic circuit inductor with a metal thin film, characterized in that, include: The inductor body includes a magnetic core body (3) and a housing (1). The magnetic core body (3) is configured as a closed magnetic circuit structure, and the housing (1) is disposed around the magnetic core body (3). The surface of the outer shell (1) is formed by a metal thin film layer (2) through a physical vapor deposition process.

2. The closed magnetic circuit inductor with a metal thin film according to claim 1, characterized in that: The thickness t of the metal thin film layer (2) is 10nm-500nm.

3. The closed magnetic circuit inductor with a metal thin film according to claim 1, characterized in that: The metal thin film layer (2) covers part or all of the outer shell (1).

4. The closed magnetic circuit inductor with a metal thin film according to claim 2, characterized in that: The metal thin film layer (2) is arranged in multiple strips on the surface of the outer shell (1), and each metal thin film layer (2) is arranged at a interval G; wherein G≥3t.

5. The closed magnetic circuit inductor with a metal thin film according to claim 2, characterized in that: The metal thin film layer (2) is distributed in a grid pattern on the surface of the outer shell (1), wherein the grid aperture d is 0.5-3mm.

6. The closed magnetic circuit inductor with a metal thin film according to any one of claims 1-5, characterized in that: The outer shell (1) includes a shell and a heat-conducting structure disposed in the shell. The heat-conducting structure includes a plurality of heat-conducting pipes (11) disposed in the outer shell (1). Each heat-conducting pipe (11) is provided with a heat-absorbing end (111) and a heat-dissipating end (112). The heat-absorbing end (111) is disposed on the inner wall of the shell, and the heat-dissipating end (112) is disposed on the outer wall of the shell.

7. The closed magnetic circuit inductor with a metal thin film according to claim 6, characterized in that: A metal base layer (4) is also provided on the outer wall of the shell. One side of the metal base layer (4) is connected to the heat dissipation end (112) of the heat pipe (11). The metal thin film layer (2) is sputtered on the metal base layer (4).

8. The closed magnetic circuit inductor with a metal thin film according to any one of claims 1-5, characterized in that: The magnetic core body (3) is a ring or EE structure.

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