Common mode inductor

Abstract

The utility model relates to a common mode inductor, which comprises a base, a magnet, a coil and a terminal, and is characterized in that the magnet is in a hollow column shape, the coil is wound on the magnet and is connected with the terminal, the base comprises a top plate and a side plate, the top plate and the side plate are enclosed to form an installation space, the magnet is arranged in the installation space, and the terminal is arranged in the installation space. The terminals are arranged on the side plates in a penetrating mode, and the bottoms of the side plates are coplanar at the positions corresponding to the terminals. When the common-mode inductor is welded on a circuit board, the common-mode inductor can be sucked on the top plate by a sucker and then moved to a corresponding position on the circuit board. As the positions, corresponding to the terminals, of the bottoms of the side plates are coplanar, the common-mode inductor does not shake after being placed. And at the moment, the terminals are welded, so that the common mode inductor is fixed on the circuit board. By means of the common mode inductor, the purpose that the common mode inductor is easy to weld and fix can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electronic components, especially relates to a common mode inductor. BACKGROUND

[0002] In modern electronic systems, switching power supply circuit is the most direct and main source of electromagnetic interference, which will produce electromagnetic radiation, and also be sensitive to the surrounding electromagnetic environment, when multiple devices exist in an environment at the same time, their interaction may be more intense, thereby affecting the performance, reliability and safety of the device. Therefore, more and more international standards and specifications regulate the compatibility and compliance of electronic devices in the electromagnetic environment. As a key magnetic component in EMC circuit, common mode inductor is crucial to suppress common mode interference and protect signal integrity.

[0003] At present, the common mode inductor commonly used in switching power supply EMC circuit is usually made of annular magnetic ring, vertical or horizontal installation structure, made of high-conductivity Mn-Zn ferrite material or amorphous nanocrystalline material, and the installation mode is mostly plug-in installation. This kind of structure design is inconvenient to install, has no base fixation, PIN pin is easy to deform, and the product is also easy to tilt after welding. Some middle and high-end products increase the base at the bottom of the magnetic ring to fix and install, but since it is usually a plug-in structure, the efficiency of PCB assembly is low, resulting in a lot of labor cost consumption. Some designs use shell plus guide needle or hardware terminal to realize SMD design, but this kind of design is usually for small common mode inductor in signal processing, the current processing capacity is relatively weak, and the inductance value is not high, which can only process high-frequency interference near CAN or USB interface, and cannot be applied to switching power supply front EMC circuit. Another kind of SMD common mode inductor has a size and structure suitable for switching power supply front EMC circuit, adopts thick soldering of enameled wire, and the pins are wound on the four corners of the CASE to realize SMD assembly, but the four pins of this kind of design often have protrusions in the winding process, it is difficult to realize coplanarity, and it is easy to cause virtual welding or false welding or even delamination in the welding process. In order to make the four welding points in a good coplanarity, a lot of tooling and labor cost is needed for processing, and the production efficiency is very low. SUMMARY

[0004] The utility model provides a common mode inductor for realizing the purpose of easy welding and fixing common mode inductor.

[0005] The utility model provides a common mode inductance, including base, magnet, coil and terminal, the magnet is hollow column, the coil is wound on the magnet and is connected the terminal, the base includes top plate and side plate, the top plate and side plate enclose and form the mounting space, the magnet is located in the mounting space, the terminal is worn in the side plate, the side plate bottom is at the terminal place common plane.

[0006] According to an embodiment of the utility model, one end of the terminal downward has tin climbing hook, the tin climbing hook is covered in the outside of side plate.

[0007] According to an embodiment of the utility model, the side plate is equipped with support platform at the tin climbing hook, and the support platform is used for supporting the terminal forming.

[0008] According to an embodiment of the utility model, the side plate is equipped with installation platform at the tin climbing hook, so that the tin climbing hook can be bent to form the tin climbing hook outside the side plate.

[0009] According to an embodiment of the utility model, one end of the terminal upward has wire holder, and the coil is wound on the wire holder.

[0010] According to an embodiment of the utility model, the wire holder has limiting portion and winding portion, the width of winding portion is less than the width of limiting portion, and the coil is wound on the winding portion.

[0011] According to an embodiment of the utility model, the side plate and the top plate have opening.

[0012] According to an embodiment of the utility model, the inside of side plate has arc structure matching the magnet.

[0013] According to an embodiment of the utility model, the magnet is made of one of Mn-Zn ferrite, Nn-Zn ferrite and amorphous nanocrystalline material.

[0014] According to an embodiment of the utility model, the base is made of engineering plastics.

[0015] The utility model discloses an embodiment, has following beneficial effect:

[0016] The two groups of coils are wound on the magnet, each group of coils has two ends, and the two ends are connected to a terminal respectively. The magnet is placed in the mounting space formed by the base, the base includes a top plate and a side plate, the terminal is arranged in the side plate, and the bottom of the side plate is coplanar with the terminal. Therefore, when the common mode inductor is welded on the circuit board, the top plate can be sucked by the suction cup and then moved to the corresponding position on the circuit board. Since the bottom of the side plate is coplanar with the terminal, the common mode inductor will not shake when it is placed. At this time, the terminal is welded to fix the common mode inductor on the circuit board. The common mode inductor in the utility model can be easily welded and fixed. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Among them:

[0019] Figure 1 is a schematic diagram of the overall structure of a common mode inductor in the embodiments of the present application;

[0020] Figure 2 is a schematic diagram of the overall structure of another angle of a common mode inductor in the embodiments of the present application;

[0021] Figure 3 is a schematic diagram of the overall structure of a base and a terminal after assembly in the embodiments of the present application;

[0022] Figure 4 is a schematic diagram of the overall structure of a base and a terminal after assembly in the embodiments of the present application;

[0023] Figure 5 is a schematic diagram of the overall structure of a terminal in the embodiments of the present application;

[0024] Figure 6 is a schematic diagram of the structure in several embodiments of a terminal in the embodiments of the present application;

[0025] Figure 7 is a schematic diagram of the assembly principle of a magnet and a coil in the embodiments of the present application.

[0026] Reference signs:

[0027] Base-10; Magnet-20; Coil-30; Terminal-40; Top plate-110; Side plate-120; Mounting space-130; Tin climbing hook-410; Support table-1210; Mounting table-1220; Wire frame-420; Limiting part-4210; Winding part-4220; Opening-140; Arc structure-1230. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme in the utility model will be described clearly and completely below in combination with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0029] The utility model embodiment provides a kind of common mode inductance, please refer to Figures 1-6 Including base 10, magnet 20, coil 30 and terminal 40, magnet 20 is hollow column, coil 30 is wound on magnet 20 and is connected terminal 40, base 10 includes top plate 110 and side plate 120, top plate 110 and side plate 120 are enclosed and form mounting space 130, magnet 20 is located in mounting space 130, terminal 40 is arranged on side plate 120, and the bottom of side plate 120 is coplanar at the position corresponding to terminal 40.

[0030] Use the common mode inductance of the embodiment, two groups of coils 30 are wound on magnet 20, and each group of coils 30 has two ends, which are connected to a terminal 40 respectively.Magnet 20 is placed in the mounting space 130 formed by base 10, and base 10 includes top plate 110 and side plate 120, terminal 40 is arranged in side plate 120, and the bottom of side plate 120 is coplanar at the position corresponding to terminal 40.Therefore, when the common mode inductance is welded on the circuit board, the top plate 110 can be moved to the corresponding position on the circuit board by using the suction cup.Because the bottom of side plate 120 is coplanar at the position corresponding to terminal 40, the common mode inductance will not shake when it is placed.At this time, the terminal 40 is welded to fix the common mode inductance on the circuit board.Using the common mode inductance in the utility model can achieve the purpose of easy welding and fixing common mode inductance.

[0031] Coil 30 can be round enameled wire, or rectangular flat wire or square wire.

[0032] In an embodiment, please refer to Figures 3-5 The end of terminal 40 downward has tin climbing hook 410, and the tin climbing hook 410 is covered outside side plate 120.

[0033] The main function of the tin climbing hook 410 is to provide a good tin climbing space for welding, form a tin climbing angle, and make the welding more reliable. The tin climbing space generally refers to the climbing height of the solder (usually tin) on the pins or pads of the welding elements during the welding process. This height is an important parameter of the welding quality, as it affects the reliability of the welding and the stability of the electrical connection of the elements.

[0034] In an embodiment, referring to Figure 2 and Figure 3 The side plate 120 is provided with a support table 1210 corresponding to the tin climbing hook 410, which is used to support the terminal 40 during molding.

[0035] The terminal 40 is integrally molded with the plastic shell through an injection molding process. This technology can improve production efficiency, reduce assembly procedures, reduce costs, and enhance product stability and reliability.

[0036] The support table 1210 protrudes from the bottom surface of the side plate 120, which is equivalent to a protruding step. On the one hand, it can be used to support the terminal 40, especially the tin climbing hook 410 of the terminal 40. On the other hand, the circuit board is usually provided with a mounting groove corresponding to the support table 1210. The insertion of the support table 1210 into the mounting groove can position the common mode inductor in the utility model, which facilitates the subsequent welding work of the tin climbing hook 410.

[0037] In an embodiment, the side plate 120 is provided with a mounting table 1220 corresponding to the tin climbing hook 410, so that the tin climbing hook 410 can be bent outwardly to form a tin climbing hook 410.

[0038] The mounting table 1220 is located on the outer side of the side plate 120, which is equivalent to a negative step formed in the lower part of the mounting table 1220. This is because the length of the tin climbing hook 410 of the terminal 40 is limited. If there is no mounting table 1220, the terminal 40 will be difficult to be bent and covered on the outer side of the side plate 120.

[0039] It should be noted that the terminal 40 is usually in a sheet shape. After the terminal 40 is integrally molded with the base 10, the terminal 40 needs to be bent downward to cover the lower edge of the side plate 120.

[0040] In an embodiment, the terminal 40 has a lead frame 420 at one end thereof. The coil 30 is wound on the lead frame 420.

[0041] The lead frame 420 is used to connect the coil 30. The terminal 40 as a whole is conductive, while the base 10 is insulating. Therefore, when the common mode inductor is mounted on the circuit board, the current passes through the tin climbing hook 410, the lead frame 420, and the coil 30, forming an electrical path.

[0042] In an embodiment, referring to Figure 5 and Figure 6 The lead frame 420 has a limiting portion 4210 and a winding portion 4220, the width of the winding portion 4220 is smaller than the width of the limiting portion 4210, and the coil 30 is wound on the winding portion 4220.

[0043] In this embodiment, the width of the limiting portion 4210 is wider than the width of the winding portion 4220. Therefore, when the coil 30 is wound on the limiting portion 4210, the limiting portion 4210 will prevent the coil 30 from falling off the terminal 40. The limiting portion 4210 cooperates with the tin climbing hook 410, so that the terminal 40 is fixed. The terminal 40 will fix the coil 30 together with the magnet 20.

[0044] Referring to Figure 6 The terminal 40 needs to be electroplated, such as nickel plating and tin plating. The shape of the terminal winding hook can be "paddle" shape, or the following other shapes, to prevent the lead from loosening or connecting poorly.

[0045] In an embodiment, the side plate 120 and the top plate 110 have an opening 140 therebetween.

[0046] The main functions of the opening 140 are two-fold. On the one hand, it facilitates the winding of the coil 30 on the terminal 40. On the other hand, it can form a heat dissipation channel to reduce the temperature of the coil 30 and the magnet 20 through air convection.

[0047] Generally, the opening 140 is symmetrically arranged with the magnet 20 as the center, which is conducive to air convection.

[0048] In an embodiment, the inner side of the side plate 120 has an arc-shaped structure 1230 matching the magnet 20.

[0049] The magnet 20 can be ring-shaped, track-shaped, rectangular, bracelet-shaped, etc. In most cases, the outer circumferential surface of the selected magnet 20 is arc-shaped, and the inner side of the side plate 120 has an arc-shaped structure 1230 matching the magnet 20, which can relatively fix the magnet 20 and the base 10.

[0050] In an embodiment, the magnet 20 is made of one of Mn-Zn ferrite, Nn-Zn ferrite and amorphous nanocrystalline material.

[0051] Mn-Zn ferrite (manganese zinc ferrite): It is a kind of soft magnetic ferrite, which belongs to spinel structure, made of oxides and salts of iron, manganese and zinc by ceramic process. It has high initial permeability, generally used in the frequency range of 1 kilohertz to 10 megahertz.

[0052] Ni-Zn ferrite (nickel-zinc ferrite): It is a kind of high-frequency soft magnetic ferrite with spinel structure. The relative initial permeability μa is 15-70, the coercive force is 238.8-557.2 A / m, the Curie point is 350-450 DEG C, and the resistivity is 5*10^4 ohm*cm. The main raw materials are oxides or salts of iron, nickel and zinc, and it is manufactured by electronic ceramic process. Due to the characteristics of high frequency, wide frequency, high impedance and low loss, the nickel-zinc ferrite has been paid more and more attention in recent years, and has become the soft magnetic ferrite material with the widest application and excellent performance in the high frequency range (1-100 MHz).

[0053] Amorphous nanocrystalline soft magnetic alloy is a new type of magnetic material, which has high saturation magnetization and excellent soft magnetic properties. They are usually prepared by melt quenching combined with vacuum heat treatment and magnetic field heat treatment technology, and have refined ingot organization and optimized ratio of nanocrystalline alpha-Fe (Si) phase and amorphous phase. The saturation magnetic induction intensity of the material is 1.26-1.49T, the initial magnetic permeability is 125k-148k, and the material is widely used in transformer, mutual inductor, inverter, choke and other electrical components.

[0054] In an embodiment, the base 10 is made of engineering plastic.

[0055] The material of the base 10 can be bakelite, LCP or other engineering plastic, which mainly requires insulation and certain high temperature resistance.

[0056] In the description of the embodiments of the utility model, it should be explained that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the embodiments of the utility model and simplifying the description, and therefore cannot be understood as a limitation on the embodiments of the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0057] In the description of the embodiments of the utility model, it should be explained that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary skilled in the art, the specific meaning of the above terms in the embodiments of the utility model can be understood according to the specific circumstances.

[0058] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature can be "above", "over" and "on" the second feature, which can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature can be "under", "below" and "under" the second feature, which can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0059] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0060] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A common mode inductor comprising a base, a magnet, a coil, and a terminal, characterized in that, The magnet is in a hollow column shape, the coil is wound on the magnet and connected to the terminal, the base comprises a top plate and a side plate, the top plate and the side plate enclose an installation space, the magnet is arranged in the installation space, the terminal is arranged through the side plate, and the bottom of the side plate is coplanar with the terminal.

2. The common mode inductance of claim 1, wherein, The terminal has a tin climbing hook at the downward end, and the tin climbing hook is covered outside the side plate.

3. The common mode inductance of claim 2, wherein, The side plate is provided with a support table corresponding to the tin climbing hook, and the support table is used for supporting the terminal.

4. The common mode inductance of claim 2, wherein, The side plate is provided with a mounting table corresponding to the tin climbing hook, so that the tin climbing hook can be bent outside the side plate to form the tin climbing hook.

5. The common mode inductance of claim 1, wherein, The terminal has a lead frame at the upward end, and the coil is wound on the lead frame.

6. The common mode inductance of claim 5, wherein, The lead frame has a limiting portion and a winding portion, the width of the winding portion is smaller than the width of the limiting portion, and the coil is wound on the winding portion.

7. The common mode inductance of claim 1, wherein, The side plate and the top plate have an opening therebetween.

8. The common mode inductance of claim 1, wherein, The inner side of the side plate has an arc-shaped structure matching the magnet.

9. The common mode inductance of claim 1, wherein, The magnet is made of one of Mn-Zn ferrite, Nn-Zn ferrite and amorphous nanocrystalline material.

10. The common mode inductance of claim 1, wherein, The base is made of engineering plastic.

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