Hot-pressed dual inductor for reducing emi

Abstract

The utility model discloses a kind of hot-pressing double inductors of reducing EMI, by E-type magnetic core, C-type magnetic core and integrally-formed double-hook type coil combination forming, the E-type magnetic core main body is formed as flat square block, and the surface of E-type magnetic core is formed with the special-shaped groove suitable for double-hook type coil compatible therein, the C-type magnetic core is formed as the square block cover body with bottom gap cavity, and the gap cavity is adapted to connect E-type magnetic core, three parts are assembled and hot-pressed into encapsulation, and double-hook type coil is set as four electrode pads in the bottom of encapsulation. The present hot-pressing double inductor can effectively save the space occupied in PCB, while the double inductors cancel each other's magnetic force lines, effectively suppress the inductance EMI leakage, improve the performance of inductor device, further improve the operating environment of circuit.

Description

Technical Field

[0001] This utility model relates to an inductor device, and more particularly to a thermo-pressed dual inductor with mutually canceling magnetic fields, belonging to the technical field of basic electronic components. Background Technology

[0002] Inductors are one of the most commonly used components in electronic devices, widely used in various circuits to perform functions such as filtering, energy storage, matching, and resonance. With the increasing miniaturization and portability of electronic products, and the high-density assembly of components, inductor components have developed rapidly. Furthermore, considering electromagnetic compatibility, the ability of electronic products to resist electromagnetic interference has become a basic design requirement, thus increasing the demand for and application of inductors.

[0003] Currently, after most inductors in the industry have undergone structural design and application production, it has been found that the overflowing magnetic lines of force have a significant impact on surrounding inductors. Furthermore, the number of components and the space occupied in high-density PCBs also restrict the circuit design and miniaturization of functional devices to some extent. Therefore, the integration of multiple inductors within a limited space and the suppression of inductor EMI leakage have become a technological gap that urgently needs to be filled in the industry. Summary of the Invention

[0004] The purpose of this invention is to propose a thermo-pressed dual inductor to reduce EMI, aiming to counteract magnetic field lines and optimize the space occupied by components in high-density PCBs.

[0005] The technical solution of this utility model to achieve the above-mentioned objective is: a thermo-pressed dual inductor with reduced EMI, which is formed by combining an E-type magnetic core, a C-type magnetic core and an integrally formed double-hook coil. The main body of the E-type magnetic core is formed into a flat square, and the surface of the E-type magnetic core is formed with irregular grooves suitable for the double-hook coil to fit into. The C-type magnetic core is formed into a square cover with a bottom notch, and the notch is adapted to fit the E-type magnetic core. The three parts are assembled and thermo-pressed into a package, and the double-hook coil has four electrode pads exposed at the bottom of the package.

[0006] Furthermore, the irregular groove is segmented and integrally connected, including two parallel and spaced transverse grooves on the surface of the E-type magnetic core, a vertical groove extending from the same direction end of the transverse groove on one side of the E-type magnetic core to the bottom surface, and a wide groove extending from the same direction end of the transverse groove on the other side of the E-type magnetic core and its spaced portion to the bottom surface. The E-type magnetic core is provided with baffles on both sides of the irregular groove.

[0007] Furthermore, the horizontal and vertical grooves are embedded in the hook portion of the double-hook coil, and the wide groove is embedded in the connecting base of the double-hook coil. The top and side surfaces of the double-hook coil are both lower than the profile of the retaining wall.

[0008] Furthermore, the double-hook coil is formed by bending a U-shaped copper block, wherein the lower section of the U-shaped copper block is formed into a vertical connecting base, and the middle and upper section of the U-shaped copper block is formed into a hook. The hook is bent horizontally from the top side of the connecting base and bent a second time into a standing foot parallel to the connecting base. The bottom ends of the connecting base and the two standing feet protrude at the bottom of the package.

[0009] Furthermore, both the E-type magnetic core and the C-type magnetic core are cold-pressed bodies made of powder material based on a customized mold.

[0010] Furthermore, a cross-shaped boss is formed on the bottom surface of the hot-pressing mold cavity of the package, and the four electrode pads at the bottom of the package are separated from each other; and a gap is left between the side wall of the hot-pressing mold cavity and the outer wall of the C-shaped magnetic core.

[0011] Furthermore, the surface of the package is covered with a fully insulating varnish, and the bottom of the package is partially stripped of the varnish and electroplated to form electrode pads.

[0012] Compared with existing technologies, the advantages of this hot-pressed dual inductor are as follows: by optimizing the prefabricated shape of the two magnetic cores and coils, the dual inductors are integrated into the same device, effectively saving space on the PCB; and the coils are integrally formed as two coils side by side, which improves assembly stability and can cancel each other out magnetic lines of force, effectively suppressing inductor EMI leakage, improving the performance of the inductor device, further improving the circuit operating environment, and promoting the development of hardware performance in application scenarios such as artificial intelligence servers / data centers / autonomous driving. Attached Figure Description

[0013] Figure 1 This is a close-up structural diagram of the E-type magnetic core in the hot-pressed dual inductor of this utility model.

[0014] Figure 2 This is a schematic diagram of the forming structure of the double-hook coil in the hot-pressed dual inductor of this utility model.

[0015] Figure 3 This is a close-up structural diagram of the C-shaped magnetic core in the hot-pressed dual inductor of this utility model.

[0016] Figure 4 This is a schematic diagram showing the external evolution of the hot-pressed dual inductor of this utility model during assembly and manufacturing. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0018] This invention proposes a thermo-pressed dual inductor to reduce EMI, aiming to counteract magnetic field lines and optimize the space occupied by components in high-density PCBs. Figures 1 to 4 As shown, the basic structure of this dual inductor is formed by combining a pre-formed E-type magnetic core 1, a C-type magnetic core 3, and an integrally formed double-hook coil 2, and is obtained through a series of processes such as thermoforming, painting, partial paint stripping, and electroplating. In summary, the E-type magnetic core 1 is mainly formed into a flat cube, and its surface has irregularly shaped slots 11 suitable for the double-hook coil 3 to accommodate it. A boss 13 is retained in the middle to partially separate the irregularly shaped slots. The C-type magnetic core 2 is formed into a cube-shaped cover with a bottom notch 21, which is adapted to connect to the E-type magnetic core 1, so that the E-type magnetic core is wrapped by the C-type magnetic core. The three parts are assembled and thermo-pressed into a package. As the basis for the inductor to connect to the PCB, the double-hook coil 3 has four electrode pads exposed at the bottom of the package; the specific distribution shape will be detailed later.

[0019] For the design considerations of dual inductors and mass production, both types of magnetic cores and double-hook coils mentioned above can be prefabricated and reused in batches. Based on the overview of this technical solution and the illustrations of preferred embodiments, the detailed features of each functional component of this inductor also include: Figure 1 The E-type magnetic core shown has a segmented yet integrally connected groove 11, comprising two parallel and spaced horizontal grooves 111 on the surface of the E-type magnetic core, a vertical groove 112 extending from the same-direction end of one horizontal groove to the bottom surface on one side of the E-type magnetic core, and a wide groove 113 extending from the same-direction end of the horizontal groove on the other side of the E-type magnetic core and its spacer portion (i.e., the boss side) to the bottom surface. The E-type magnetic core also has retaining walls 12 on both sides of the groove. The horizontal grooves 111 and 112 are embedded within the hook portion of the double-hook coil, while the wide groove 113 is embedded within the connecting base of the double-hook coil. The top and side surfaces of the double-hook coil are lower than the contour of the retaining walls. Thus, the groove, formed and positioned between the retaining walls and the boss, provides assurance for the pre-assembly and positioning of the double-hook coil.

[0020] Figure 2 The double-hook coil 3 shown is formed by bending a U-shaped copper block (which can also be regarded as a sheet with a certain thickness). The lower section of the U-shaped copper block is formed into a vertical connecting base 31, and the upper middle section of the U-shaped copper block is formed into a hook. More specifically, the middle section 32 of the hook is bent horizontally from the top side of the connecting base and bent a second time to form a vertical foot 33 parallel to the connecting base. Since both are facing downwards, the bottom ends of the connecting base and the two vertical feet are slightly stretched and extended so that they can protrude from the bottom of the package.

[0021] The E-type magnetic core 1 and C-type magnetic core of the above-mentioned preferred embodiments are both assemblies prefabricated based on powder materials and customized molds, specifically using a cold pressing molding process. The powder material used for the magnetic core can be one or more mixtures of Fe-based / FeSiCr / FeSiAl / FeNi / FeSi / amorphous / nanocrystalline materials, and one of epoxy resin, silicone resin or acrylic resin is added and stirred evenly before being injected into a customized mold that conforms to the shape of the device, and the molding pressure range is 6-12 Tons / cm².

[0022] like Figure 4 As shown in the schematic diagram of the complete manufacturing process of the preferred embodiment of the dual inductor: First, E-type magnetic cores, C-type magnetic cores, and double-hook coils are prefabricated in groups of three. Then, the double-hook coils are pre-assembled into the E-type magnetic core as a base to obtain the first pre-assembled body A. Note that the assembly direction of the two is such that the connecting base corresponds to the wide groove, and the upright foot corresponds to the vertical groove. Then, the C-type magnetic core is fitted onto the first assembly from top to bottom, and the surface is adjusted to align the edges to obtain the assembled body B. Next, the assembled body is transferred into a hot press mold. The bottom surface of the hot press mold cavity is formed with a cross-shaped boss, and a gap is left between the inner wall of the hot press mold cavity and the outer wall of the C-type magnetic core. The gaps are filled with one or more of the following: Fe-based / FeSiCr / FeNi / FeSiAl / amorphous or nanocrystalline materials. The mixture is then held at a molding temperature of 100-200℃ and a molding pressure of 4-12 Tons / cm² for 30-180 seconds to obtain a thermoformed package. Specifically, due to the cross-shaped boss on the bottom surface of the thermoforming mold, the four electrode pads at the bottom of the resulting package are spaced apart. After cooling, the package is painted to fully cover its surface with an insulating varnish film 4, resulting in an enamel-coated body C. Then, partial varnish stripping is performed to expose the ends 34 of the double-hook coil, resulting in an electroplated pre-body D. Finally, electroplating is used to form the electrode pads 5 distributed at the four corners of the bottom surface of the dual inductor. The finished inductor device E undergoes external inspection, testing, quality inspection, packaging, and shipment sequentially.

[0023] In summary, the preferred embodiment of the thermo-pressed dual inductor for reducing EMI of this utility model is described in detail above. Compared with the prior art, its technical effects are as follows: by optimizing the prefabricated shape of the two magnetic cores and coils, the dual inductors are integrated into the same device, effectively saving space on the PCB; and the coils are integrally formed as two coils side by side, which improves assembly stability and can cancel each other out magnetic lines of force, effectively suppressing inductor EMI leakage, improving the performance of the inductor device, further improving the circuit operating environment, and promoting the development of hardware performance in application scenarios such as artificial intelligence servers / data centers / autonomous driving.

[0024] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A hot-pressed dual inductor for reducing EMI, characterized by: The inductor is formed by combining an E-type magnetic core, a C-type magnetic core, and an integrally formed double-hook coil. The E-type magnetic core is formed into a flat square, and the surface of the E-type magnetic core is formed with irregular grooves suitable for the double-hook coil to fit into. The C-type magnetic core is formed into a square cover with a bottom notch, and the notch is adapted to fit the E-type magnetic core. The three parts are assembled and hot-pressed into a package, and the double-hook coil has four electrode pads exposed at the bottom of the package.

2. The hot-pressed dual-inductor for EMI reduction of claim 1, wherein: The irregular groove is segmented and integrally connected, including two parallel and spaced horizontal grooves on the surface of the E-type magnetic core, a vertical groove extending from the same direction end of the horizontal groove on one side of the E-type magnetic core to the bottom surface, and a wide groove extending from the same direction end of the horizontal groove on the other side of the E-type magnetic core and its spacer portion to the bottom surface. The E-type magnetic core is provided with baffles on both sides of the irregular groove.

3. The hot-pressed dual-inductor for EMI reduction of claim 2, wherein: The horizontal and vertical slots are embedded in the hook portion of the double-hook coil, and the wide slot is embedded in the connecting base portion of the double-hook coil. The top and side surfaces of the double-hook coil are lower than the profile of the retaining wall.

4. The hot-pressed dual-inductor for EMI reduction of claim 1, wherein: The double-hook type coil is formed by bending a U-shaped copper block. The lower section of the U-shaped copper block is formed into a vertical connecting base, and the middle and upper section of the U-shaped copper block is formed into a hook. The hook is bent horizontally from the top side of the connecting base and then bent a second time to form a vertical foot parallel to the connecting base. The bottom ends of the connecting base and the two vertical feet protrude at the bottom of the package.

5. The hot-pressed dual-inductor for EMI reduction of claim 1, wherein: Both the E-type and C-type magnetic cores are cold-pressed bodies made of powder material based on a customized mold.

6. The hot-pressed dual-inductor for EMI reduction of claim 1, wherein: The bottom surface of the hot-pressing mold of the package is formed with a cross-shaped boss, and the four electrode pads at the bottom of the package are separated from each other; and there is a gap between the side wall of the hot-pressing mold and the outer wall of the C-shaped magnetic core.

7. The hot-pressed dual-inductor for EMI reduction of claim 1, wherein: The surface of the package is covered with a fully insulating varnish, and the bottom of the package is partially stripped of the varnish and electroplated to form electrode pads.

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