A compact large integrated inductor structure

Abstract

The application relates to the technical field of inductors, in particular to a compact large integrated inductor structure which comprises a coil assembly, a magnetic powder filling layer and an electroplated terminal layer, the coil assembly is built in the magnetic powder filling layer, the electroplated terminal layer is directly formed on the surface of the magnetic powder filling layer and is connected with the coil assembly, without the need of traditional hardware pieces in the integrated inductor, the product volume is maximally utilized, meanwhile, the condition that the volume occupied by the piece corner is too large and the piece is easy to separate is reduced, and the application has the characteristics of improving the stability of the product.

Description

Technical Field

[0001] This application relates to the field of inductor technology, and in particular to a compact, large-scale integrated inductor structure. Background Technology

[0002] An integrated inductor is an inductor element formed by die-casting a coil with magnetic powder. Its core function is to provide efficient and stable current management for electronic devices.

[0003] In related technologies, the traditional manufacturing of low-inductance, high-capacity integrated inductors generally adopts a sheet-type structure. This involves winding enameled wire into a coil and then soldering it onto a metal sheet. After powder filling, pressing, and curing, the metal sheet is finally folded onto a magnet to form an electrode, thus completing the production process.

[0004] The existing sheet metal inductor structure has the following problems: the bent-leg structure of the metal sheet occupies too much volume, which is not conducive to the miniaturization of the product, and the separation of the bent legs from the magnet can easily cause the terminals to lift up, affecting the reliability and service life of the product. Summary of the Invention

[0005] To improve product stability, this application provides a compact, large integrated inductor structure.

[0006] The compact, integrated inductor structure provided in this application adopts the following technical solution: A compact, integrated inductor structure includes: a coil assembly, a magnetic powder filling layer, and an electroplated terminal layer. The coil assembly is embedded in the magnetic powder filling layer, and the electroplated terminal layer is formed directly on the surface of the magnetic powder filling layer and connected to the coil assembly.

[0007] By adopting the above solution, the coil assembly, magnetic powder filling layer and electroplated terminal layer work together to achieve efficient energy conversion and signal processing. The electroplated terminal layer is formed directly on the surface of the magnetic powder filling layer, eliminating the need for metal sheets in traditional integrated inductors, maximizing the use of product volume, and reducing the occurrence of excessive volume occupation and easy separation of sheet corners, making the product more stable and reliable.

[0008] Preferably, the electroplated terminal layer is formed by electroplating on the peeled surface after the magnetic powder filling layer is surface-insulated and laser-stripped.

[0009] By adopting the above scheme, the magnetic powder filling layer effectively blocks the conductive path between magnetic powder particles after being insulated, thereby reducing inductive loss. Laser stripping can selectively remove the insulating varnish on the surface of the magnetic powder filling layer and expose the contact points of the coil assembly. The electroplated terminal layer can be directly grown on the stripped surface of the magnetic powder filling layer through the electroplating process, effectively reducing contact resistance.

[0010] Preferably, the electroplated terminal layer is located on both sides of the magnetic powder filling layer and is arranged in an L-shaped structure.

[0011] By adopting the above scheme, the L-shaped bending structure increases the contact area between the electroplated terminal layer and the magnetic powder filling layer, and the double-sided symmetrical layout disperses the current path and reduces local heat generation.

[0012] Preferably, the electroplated terminal layer is flush with the surface of the magnetic powder filling layer.

[0013] By adopting the above solution, the electroplated terminal layer and the magnetic powder filling layer are mechanically interlocked to form an integrated structure, which reduces local heat accumulation and reduces the occurrence of magnetic field distortion caused by the protrusion of the electroplated terminal layer.

[0014] Preferably, the magnetic powder filling layer is sequentially covered by a primary filling layer and a secondary filling layer from the inside out, wherein the magnetic powder particle size in the primary filling layer is smaller than that in the secondary filling layer.

[0015] By adopting the above scheme, after the magnetic powder filling layer is pressed and cured, the magnetic powder particle size gradient and pressure gradient are balanced, and a "dense inside and rigid outside" topological structure is formed under the protection of the insulation layer, taking into account both high-frequency performance and mechanical strength.

[0016] Preferably, the coil assembly is embedded between the primary powder filling layer and the secondary powder filling layer, and the axial ends of the coil assembly pass through the magnetic powder filling layer and are in close contact with the electroplated terminal layer.

[0017] By adopting the above solution, the welding interface of the traditional sheet structure is eliminated, the current transmission efficiency is improved, and the magnetic powder filling layer forms a wrapping support for the coil assembly, thereby improving the vibration resistance.

[0018] Preferably, the coil assembly is formed by winding multiple strands of enameled round wire.

[0019] By adopting the above scheme, the parallel connection of multiple enameled round wires increases the effective conductive surface area and reduces AC resistance. When the enameled round wires are bent, stress concentration at the corners is reduced, which indirectly reduces the insulation layer damage rate. At the same time, the uniform gap between the multiple enameled round wires promotes heat dissipation.

[0020] Preferably, a compact integrated inductor includes the aforementioned compact integrated inductor structure, characterized in that it further includes a Tcore mold, which is adapted to the coil assembly for precise positioning and implantation of the coil assembly.

[0021] By adopting the above solution, the coil assembly and the Tcore mold are installed coaxially, reducing the occurrence of coil assembly misalignment after the secondary powder filling process.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. The electroplated terminal layer is formed directly on the surface of the magnetic powder filling layer, eliminating the need for metal sheets in traditional integrated inductors. This maximizes the use of product volume and reduces the occurrence of excessive volume occupation and easy separation of sheet corners, making the product more stable and reliable. 2. Reduced product damage and localized overheating; 3. Improved the product's vibration resistance and structural strength. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application.

[0024] Figure 2 This is a schematic diagram of the fit between the coil assembly and the electroplated terminal layer in Embodiment 1 of this application.

[0025] Figure 3 This is a schematic diagram of the overall structure of a traditional large integrated inductor sheet structure.

[0026] Figure 4 This is a schematic diagram showing the fit between the coil assembly and the Tcore mold in Embodiment 2 of this application.

[0027] Explanation of reference numerals in the attached drawings: 1. Coil assembly; 2. Electroplated terminal layer; 3. Magnetic powder filling layer; 4. Tcore mold. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0029] Example 1 This application discloses a compact, large-integration inductor structure. (Refer to...) Figure 1-3 A compact integrated inductor structure includes a coil assembly 1, a magnetic powder filling layer 3, and an electroplated terminal layer 2. The coil assembly 1 is built into the magnetic powder filling layer 3, and the electroplated terminal layer 2 is formed directly on the surface of the magnetic powder filling layer 3 and connected to the coil assembly 1.

[0030] Correspondingly, this structural design achieves a dual breakthrough in electromagnetic performance and mechanical reliability through process innovation: the coil assembly 1 and the magnetic powder filling layer 3 form an embedded magnetic circuit, and the electroplated terminal layer 2 is directly and seamlessly bonded to the surface of the magnetic powder filling layer 3 using an electroplating process. This eliminates the traditional large integrated inductor hardware sheet structure, which not only reduces the volume waste caused by sheet bending process, but also effectively improves the peel strength of the electroplated terminal layer 2 compared to the traditional welding structure through atomic-level interface bonding, making the product more stable and reliable.

[0031] Specifically, in this embodiment, the electroplated terminal layer 2 is mainly composed of copper (15-50μm), nickel (1.5-5μm) and tin (5-15μm). The electroplated terminal layer 2 is formed by electroplating on the peeled surface after the magnetic powder filling layer 3 is surface-insulated and laser-stripped.

[0032] Correspondingly, the thick copper layer serves as the main conductive layer, responsible for providing high current carrying capacity and reducing resistance loss. The nickel layer can effectively reduce the generation of high-frequency eddy currents, thereby reducing electromagnetic interference. The tin surface layer optimizes the stability of contact resistance and reduces the transmission loss of high-frequency signals.

[0033] Furthermore, the copper layer is completely encapsulated, reducing corrosion caused by direct exposure of the copper layer to air. The passivation film of the nickel layer helps reduce the penetration of corrosive media, while the oxidation resistance of the tin layer is responsible for inhibiting oxidation. At the same time, the three also work together to improve the wear resistance and deformation resistance of the electroplated terminal layer 2 through their own material hardness.

[0034] Meanwhile, after the magnetic powder filling layer 3 is covered with insulation, the conductive path between magnetic powder particles is blocked, reducing the occurrence of local short circuits between magnetic powder particles, controlling the electrical loss of the magnetic powder filling layer 3 within a reasonable range, and extending its service life.

[0035] Furthermore, laser stripping can selectively remove the insulating varnish on the surface of the magnetic powder filling layer 3 and expose the contact points of the coil assembly 1. The electroplated terminal layer 2 is directly grown on the stripped surface of the magnetic powder filling layer 3 through an electroplating process and makes contact with the contact points of the coil assembly 1, effectively reducing the contact resistance.

[0036] Specifically, in this embodiment, the electroplated terminal layer 2 is formed on both sides of the magnetic powder filling layer 3 and is arranged in an L-shaped bent structure, and the electroplated terminal layer 2 is flush with the surface of the magnetic powder filling layer 3.

[0037] Therefore, the L-shaped bending structure increases the contact area between the electroplated terminal layer 2 and the magnetic powder filling layer 3. The symmetrical layout on both sides disperses the current path and reduces local heat generation. The electroplated terminal layer 2 also forms a mechanical interlock with the magnetic powder filling layer 3 at the corner of the L-shaped bending structure, thereby improving the anti-detachment performance of the electroplated terminal layer 2.

[0038] Furthermore, the flush arrangement of the electroplated terminal layer 2 and the magnetic powder filling layer 3 eliminates the stepped interface left after welding traditional hardware sheets, reducing volume redundancy and making the product more compact.

[0039] Furthermore, the electroplated terminal layer 2 and the magnetic powder filling layer 3 are seamlessly combined to form a lateral heat conduction channel. The high thermal conductivity of the copper layer can quickly dissipate Joule heat. Combined with the lateral heat conduction of the nickel layer, it accelerates heat diffusion and reduces the hot spot temperature. At the same time, the smooth interface at the junction of the electroplated terminal layer 2 and the magnetic powder filling layer 3 reduces local distortion of the magnetic field, reduces the eddy current effect under high frequency operating conditions, and indirectly improves the energy conversion efficiency.

[0040] On the other hand, the magnetic powder filling layer 3 is covered by a primary powder filling layer and a secondary powder filling layer (not shown in the figure) from the inside to the outside, and the magnetic powder particle size in the primary powder filling layer is smaller than that in the secondary powder filling layer.

[0041] Correspondingly, fine-particle magnetic powder is filled inside the coil, and its high fluidity allows it to penetrate into the gap of the coil assembly 1, increasing the filling rate. Coarse-particle magnetic powder is filled outside the coil, and a high-density support layer is formed by high-pressure pressing, which reduces the overall powder porosity and powder leakage rate of the magnetic powder filling layer 3, thereby increasing the saturation magnetic flux density.

[0042] Therefore, after the magnetic powder filling layer 3 is pressed and cured, it achieves a balance between the magnetic powder particle size gradient and the pressure gradient, and forms a "dense inside and rigid outside" topological structure under the protection of the insulating layer, taking into account both high-frequency performance and mechanical strength.

[0043] In addition, the coil assembly 1 is embedded between the primary powder filling layer and the secondary powder filling layer. The two ends of the coil assembly 1 pass through the magnetic powder filling layer 3 and form a metal-metal contact with the electroplated terminal layer 2, eliminating the welding interface of the traditional large integrated inductor sheet structure, improving the current transmission efficiency. The primary and secondary powder filling layers form an omnidirectional wrapping support for the coil assembly 1, improving its vibration resistance.

[0044] Specifically, in this embodiment, the coil assembly 1 is formed by winding multiple strands of enameled round wire. The enameled round wire adopts a traditional winding process, which eliminates the need for the precise arrangement and welding process required for the flat wire used in traditional integrated inductors, thereby reducing the product's manufacturing cost.

[0045] Furthermore, the parallel connection of multiple enameled round wires increases the effective conductive surface area and reduces AC resistance. When the enameled round wires are bent, stress concentration at the corners is reduced, which indirectly reduces the insulation layer damage rate.

[0046] Meanwhile, the uniform gaps between multiple enameled round wires form a network of micro heat dissipation channels, which promotes heat diffusion and reduces the rate of temperature rise.

[0047] The implementation principle of a compact integrated inductor structure in this application embodiment is as follows: First, a basic magnetic circuit frame is formed by primary powder filling. Then, a pre-wound coil assembly 1 is placed in and a secondary powder filling is performed. The coil assembly 1 is embedded in the magnetic powder filling layer 3. After pressing, curing, and surface insulation coating, a dense composite magnetic core is formed. The insulating paint surface at the end of the magnetic powder filling layer 3 is selectively removed by laser peeling and directly electroplated to form an electroplated terminal layer 2. This eliminates the mechanical connection method of hardware sheets in traditional integrated inductors, effectively improving space utilization. At the same time, it reduces the situation where the sheet is easily bent and warped, separating from the magnet and causing poor contact. Finally, a highly reliable inductor device with integrated structure and function is realized.

[0048] Example 2 A compact, large integrated inductor, reference Figure 4 The invention includes a compact integrated inductor structure as described in Embodiment 1, characterized in that it further includes a Tcore mold 4. In this embodiment, the Tcore mold 4 is a flat plate-like structure with a cylinder at the center. The Tcore mold 4 is adapted to the cylindrical cavity formed by winding the coil assembly 1, and is used to accurately position and assist in the implantation of the coil assembly 1, so that the coil assembly 1 and the Tcore mold 4 are coaxially installed, reducing the occurrence of the coil assembly 1 shifting after the secondary powder filling process.

[0049] The implementation principle of a compact integrated inductor structure in this application embodiment is as follows: First, the pre-wound coil assembly 1 is precisely positioned and implanted into the Tcore mold 4. A dense magnetic core is formed through magnetic powder filling, pressing and molding and curing processes. After surface insulation treatment, the end paint layer is selectively removed by laser peeling and electroplating is directly used to form an electroplated terminal layer 2 to achieve electrical connection, thus completing the synergistic optimization of product structural strength and space efficiency.

[0050] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A compact, large-scale integrated inductor structure, characterized in that, It includes a coil assembly (1), a magnetic powder filling layer (3), and an electroplated terminal layer (2). The coil assembly (1) is built into the magnetic powder filling layer (3), and the electroplated terminal layer (2) is formed directly on the surface of the magnetic powder filling layer (3) and connected to the coil assembly (1).

2. The compact integrated inductor structure according to claim 1, characterized in that, The electroplated terminal layer (2) is formed by electroplating the magnetic powder filling layer (3) on the peeled surface after surface insulation coating and laser peeling.

3. The compact integrated inductor structure according to claim 2, characterized in that, The electroplated terminal layer (2) is located on both sides of the magnetic powder filling layer (3) and is arranged in an L-shaped structure.

4. The compact integrated inductor structure according to claim 2, characterized in that, The electroplated terminal layer (2) is flush with the surface of the magnetic powder filling layer (3).

5. The compact integrated inductor structure according to claim 1, characterized in that, The magnetic powder filling layer (3) is covered by a primary filling layer and a secondary filling layer from the inside out. The magnetic powder particle size in the primary filling layer is smaller than that in the secondary filling layer.

6. The compact integrated inductor structure according to claim 5, characterized in that, The coil assembly (1) is embedded between the primary powder filling layer and the secondary powder filling layer, and the two axial ends of the coil assembly (1) pass through the magnetic powder filling layer (3) and are in close contact with the electroplated terminal layer (2).

7. The compact integrated inductor structure according to claim 1, characterized in that, The coil assembly (1) is formed by winding multiple strands of enameled round wire.

8. A compact, large integrated inductor, comprising the compact, large integrated inductor structure as described in any one of claims 1-7, characterized in that, It also includes a Tcore mold (4), which is adapted to the coil assembly (1) for precise positioning and implantation of the coil assembly (1).

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