Anti-EMI inductor

Abstract

The utility model discloses an anti-EMI inductor which is a magnetic core integrated packaging molding body with a molding coil, the molding coil is provided with two semi-closed rings which are opened in different directions and are integrally connected in series, and the free ends of the two outer sides of the molding coil are bent and extend to form electrode pins; the molded coil is used as an insert, the magnetic powder material is filled in the mold cavity and completely wraps the molded coil and then is cured into a block body, and the end parts of the electrode pins are molded into two electrode bonding pads on the surface of the block body. According to the inductor structure, due to the fact that the directions of magnetic fields generated by the two parts which are connected in series in the coil are opposite, simulation of magnetic lines of force Ansys Maxwell shows that most of the magnetic lines of force are counteracted mutually, and a very ideal EMI suppression effect can be achieved.

Description

Technical Field

[0001] The utility model relates to an inductor device, in particular to an inductor which is helpful to offset magnetic fields and reduce external electromagnetic interference, and belongs to the technical field of basic electronic components. Background Art

[0002] Inductors are the most commonly used components in electronic devices and are widely used in various circuits to achieve the functions of filtering, energy storage, matching, and resonance. As electronic products become increasingly miniaturized and portable, and components are assembled with high density, inductor components have developed rapidly; and in consideration of electromagnetic compatibility, the ability of electronic products to resist electromagnetic interference has become a basic design requirement, which has increased the demand and application of inductors.

[0003] In particular, with the rapid development of smart cities, transportation and AI smart applications (including servers and data centers), increasingly stringent performance requirements have been placed on hardware devices. Therefore, for current high-density DC-DC ConverterBuck circuit applications, the ability of inductors to suppress EMI has become a key area of ​​research and breakthrough. Summary of the invention

[0004] In view of the above-mentioned defects in the prior art, the purpose of the utility model is to provide an anti-EMI inductor, which is dedicated to enhancing the ability to suppress EMI.

[0005] The utility model provides a technical solution to achieve the above-mentioned purpose: an anti-EMI inductor, which is a magnetic core integrally packaged molded body with a molded coil, wherein the molded coil is configured as two semi-closed loops with openings in opposite directions and connected in series as a whole, and the free ends of the two outer sides of the molded coil are bent and extended to be electrode pins; the molded coil is used as an insert, and magnetic powder is filled in the mold cavity and completely wraps the molded coil and then solidified into a block, and the ends of the electrode pins are formed into two electrode pads on the surface of the block.

[0006] Furthermore, the molded coil is configured as a circular coil having two semicircles connected in series to form a sinusoidal waveform, and the magnetic powder material is molded into a magnetic core integrated with the magnetic shell in the semicircular area.

[0007] Furthermore, the formed coil is configured as a square coil having a pulse waveform formed by connecting two edge-less square frames in series, and the magnetic powder material is formed into a magnetic core integrated with the magnetic shell within the square frame area.

[0008] Furthermore, the ends of the electrode pins are partially exposed on the bottom surface of the block and formed into two electrode pads.

[0009] Furthermore, the outer end surfaces of the electrode pins are partially exposed on both sides of the block and formed into two electrode pads.

[0010] Compared with the prior art, the advantages of using the inductor of the utility model are reflected in that: since the magnetic fields generated by the two parts connected in series in the coil are in opposite directions, the magnetic field lines Ansys Maxwell simulation shows that most of the magnetic field lines can cancel each other out, which can achieve a very ideal EMI suppression effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural perspective view of a preferred embodiment of the anti-EMI inductor of the utility model.

[0012] Figure 2 It is a structural perspective view of another preferred embodiment of the anti-EMI inductor of the utility model.

[0013] Figure 3 It is an Ansys Maxwell simulation schematic diagram of a part of the preferred embodiment of the inductor of the utility model.

[0014] Figure 4 It is an Ansys Maxwell simulation schematic diagram of another part of the preferred embodiment of the inductor of the utility model.

[0015] Figure 5 It is an Ansys Maxwell simulation schematic diagram of another part of the preferred embodiment of the inductor of the utility model. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0017] In order to improve the electromagnetic interference problem caused by the inductor in the current high-density DC-DC Converter Buck circuit, it is necessary to improve the existing inductor structure to enhance its ability to suppress EMI.

[0018] like Figure 1As shown, the structure diagram of the inductor of the utility model is shown. It is a magnetic core integrally packaged molded body with a molded coil. It is a magnetic core integrally packaged molded body with a molded coil, which inherits the basic structure of various inductors. In view of the formation principle of electromagnetic interference, from the overview of its technical transformation, the molded coil is set as two semi-closed loops with opposite openings and connected in series as a whole, and the free ends of the two outer sides of the molded coil are bent and extended to be electrode pins. In this way, the shape of the coil is basically determined, creating conditions for the magnetic field formed to offset each other. Then, with the molded coil as an insert, the magnetic powder material is filled in the mold cavity and completely wraps the molded coil and then solidified into a block, and the ends of the electrode pins are formed into two electrode pads on the surface of the block. In this preferred embodiment, the molded coil is set as a circular coil 1a with two semicircles 11a and 12a connected in series to form a sinusoidal waveform, and the magnetic powder material wraps the molded coil as a whole to form a square magnetic shell 2. It can be understood that in the above two semicircular areas, it is equivalent to forming a magnetic core each, and the magnetic core and the magnetic shell are integrally formed.

[0019] and Figure 1 As shown in the figure, the main body of the formed coil is horizontally distributed, and the electrode pins 13a formed at the free ends of the two sides are bent downward. Therefore, the inductor can be welded and assembled with the PCB board in a vertical state. In addition, the outer end surface of the electrode pin 13a is partially exposed on both sides of the block, and is formed into two electrode pads 3a that are easy to position and dock by paint stripping, electroplating and other processes.

[0020] like Figures 3 to 5 As shown, after verification by magnetic force line Ansys Maxwell simulation, in the actual power-on state, the magnetic fields B1 and B2 formed in the two semicircular areas of this embodiment are in opposite directions, and the overall tendency of mutual cancellation is formed.

[0021] like Figure 2 As shown, in the preferred embodiment of the utility model, the formed coil is set as a square coil 1b with two missing edge frames 11b and 12b connected in series to form a pulse waveform. Referring to the preferred embodiment, the magnetic powder material is formed into a magnetic core integrated with the magnetic shell 2 in the square frame area. And as can be seen from the figure, the above-mentioned electrode pin 13b is also bent downward, and the distance between the outer end faces of the two is less than the length of the magnetic shell. Therefore, in order to make the electrode pad, it is necessary to thin the corresponding area at the bottom of the magnetic shell so that the end of the electrode pin 13b is partially exposed, and then formed into two electrode pads 3b with sufficient spacing and facing downward through processes such as touch-up paint, partial paint stripping, and electroplating.

[0022] On the other hand, the magnetic shell 2 of the inductor. From the perspective of the optional molding process, it can be a mixture of one or more of iron powder / FeSi / FeSiCr / FeSiAl / FeNi / amorphous / nanocrystalline, which is cold pressed or hot pressed and baked in a prefabricated mold to form a rectangular shape. The molding pressure is between 8-10T / cm², and it is baked and cured at 160-180℃ for 2-4 hours. Of course, it can also be a mixture of one or more of FeSi / FeNi / FeSiAl / amorphous / nanocrystalline, combined with silicone resin or silicone resin for high temperature sintering, and then annealed at 250-850℃ for 1-2 hours under nitrogen protection.

[0023] From the above detailed description of the embodiment of the anti-EMI inductor of the utility model, it can be seen that compared with the prior art, the present solution has substantial characteristics and progress, and its technical effect is as follows: since the magnetic fields generated by the two parts connected in series in the coil are in opposite directions, such as Figures 3 to 5 As shown in the figure, the magnetic force lines Ansys Maxwell simulation shows that most of the magnetic force lines can cancel each other out, which can achieve a very ideal EMI suppression effect.

[0024] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. An anti-EMI inductor, which is a magnetic core integrally packaged molded body with a molded coil, characterized in that: The forming coil is configured as two semi-closed loops that open in opposite directions and are connected in series as a whole. The free ends on both outer sides of the forming coil are bent and extended to form electrode pins. The forming coil is used as an insert, and magnetic powder is filled in the mold cavity and completely wraps the forming coil and then solidified into a block. The ends of the electrode pins are formed into two electrode pads on the surface of the block.

2. The anti-EMI inductor according to claim 1, characterized in that: The forming coil is configured as a circular coil with two semicircles connected in series to form a sinusoidal waveform, and the magnetic powder material is formed into a magnetic core integrated with the magnetic shell in the semicircular area.

3. The anti-EMI inductor according to claim 1, characterized in that: The formed coil is configured as a square coil with two edge-less square frames connected in series to form a pulse waveform, and the magnetic powder material is formed into a magnetic core integrated with the magnetic shell in the square frame area.

4. The anti-EMI inductor according to claim 1, characterized in that: The ends of the electrode pins are partially exposed on the bottom surface of the block and are formed into two electrode pads.

5. The anti-EMI inductor according to claim 1, characterized in that: The outer end surfaces of the electrode pins are partially exposed at two sides of the block and are formed into two electrode pads.

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