Inductor structure comprising side electrodes

Abstract

The inductance structure comprises a magnet and a coil arranged in the magnet, a first folding pin and a second folding pin are formed at the two ends of the coil respectively, and each of the first folding pin and the second folding pin comprises a bottom face part and a side face part. The bottom surface parts of the first folding pin and the second folding pin are exposed out of the magnet and are flush with the bottom surface of the magnet to serve as bottom surface electrodes, and the side surface parts of the first folding pin and the second folding pin are exposed out of the magnet and are flush with the side surface of the magnet to serve as side surface electrodes. According to the embodiment, the welding effect of the inductor can be visually checked through the side electrodes, and the welding strength can be further improved due to the fact that the contact area of the inductor and the PCB is larger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inductors, in particular to an inductor structure comprising side electrodes. BACKGROUND

[0002] With the rapid growth of the automobile industry, the bottom-soldered structure inductor has the advantages of low DCR (direct current resistance) and large current, and is suitable for power supply and EMI countermeasure circuits in a large area. The electrode of the bottom-soldered structure inductor is located on the bottom surface of the inductor. In the soldering process, the electrode on the bottom surface of the inductor is soldered with the solder pad on the PCB (printed circuit board), and the soldering connection is usually realized by using the surface mount technology (SMD).

[0003] However, the applicant finds that when the bottom-soldered structure inductor is soldered with the PCB solder pad, on the one hand, the soldering state of the bottom surface is difficult to judge visually after the inductor electrode is soldered with the solder pad; on the other hand, the tin-plating area of the electrode is smaller than that of the L-shaped electrode, and the bonding strength with the solder pad after soldering is lower. CONTENT OF THE INVENTION

[0004] Therefore, the present application provides an inductor structure comprising side electrodes, which can directly observe the soldering effect of the inductor through the side electrodes, and can further improve the soldering strength due to the larger contact area between the inductor and the PCB.

[0005] The present application provides an inductor structure comprising side electrodes, which comprises a magnet and a coil arranged inside the magnet, the two ends of the coil form a first folded leg and a second folded leg respectively, the first folded leg and the second folded leg each comprise a bottom surface part and a side surface part, the bottom surface part of the first folded leg and the second folded leg is exposed outside the magnet and flush with the bottom surface of the magnet to serve as a bottom surface electrode, and the side surface part of the first folded leg and the second folded leg is exposed outside the magnet and flush with the side surface of the magnet to serve as a side electrode.

[0006] In some embodiments, the coil extends to the bottom surface of the magnet from one end of the top surface of the magnet, and the other end of the coil forms the first folded leg and the second folded leg respectively.

[0007] In some embodiments, the magnet has a hexahedral structure, the side surface of the magnet comprises a notch, and the side surface part of the first folded leg and the second folded leg is exposed outside the magnet through the notch.

[0008] In some embodiments, the width of the notch is the same as the width of the side surface of the magnet, the length of the notch is less than or equal to the length of the side surface part of the first folded leg and the second folded leg, and the depth of the notch is between 0.1-0.3 mm.

[0009] In some embodiments, the inductor structure comprising side electrodes is formed by cutting off part of the magnet to form the gap after being integrally formed.

[0010] In some embodiments, the coil is a flat coil or a round coil.

[0011] In some embodiments, the part of the coil inside the magnet comprises a coil body and a varnish film covering the outer surface of the coil body to insulate the coil body from the magnet.

[0012] In some embodiments, the first and second folded legs of the coil are subjected to varnish film removal and metallization treatment to form the bottom electrodes and side electrodes.

[0013] In some embodiments, the metallization treatment includes PVD, electroplating or tin immersion.

[0014] In some embodiments, the side parts of the first and second folded legs comprise first and second side parts respectively located on opposite sides of the magnet.

[0015] The present application provides an inductor structure comprising side electrodes, comprising a magnet and a coil arranged inside the magnet, two ends of the coil forming a first folded leg and a second folded leg respectively, the first and second folded legs each comprising a bottom part and a side part, the bottom parts of the first and second folded legs exposed outside the magnet and flush with the bottom of the magnet to serve as bottom electrodes, and the side parts of the first and second folded legs exposed outside the magnet and flush with the sides of the magnet to serve as side electrodes. The present embodiment can intuitively view the soldering effect of the inductor through the side electrodes, and can further improve the soldering strength due to the larger contact area of the inductor with the PCB. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. 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.

[0017] Figure 1 is a structural schematic diagram of an inductor structure comprising side electrodes provided by the present application.

[0018] Figure 2 is another structural schematic diagram of an inductor structure comprising side electrodes provided by the present application.

[0019] Figure 3 is a structural schematic diagram of an inductor structure comprising side electrodes provided by the present application soldered on a PCB. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. In the case of no conflict, each of the described embodiments and its technical features can be combined with each other.

[0021] In addition, the terms "first", "second", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited. In the description of the present application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise specifically limited.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used in this description, the terms "connect", "electrically connected", "electrically connect" include any and all combinations of direct and indirect electrical or structural connections. Therefore, if it is described herein that a first device is coupled / connected / electrically connected to a second device, it means that the first device can be directly electrically / structurally connected to the second device, or indirectly electrically / structurally connected to the second device through other devices or connection means.

[0023] The present application provides an inductance structure comprising side electrodes, including a magnet and a coil arranged inside the magnet, two ends of the coil form a first folded foot and a second folded foot respectively, the first folded foot and the second folded foot each include a bottom surface part and a side surface part, the bottom surface part of the first folded foot and the second folded foot is exposed outside the magnet and flush with the bottom surface of the magnet to serve as a bottom surface electrode, and the side surface part of the first folded foot and the second folded foot is exposed outside the magnet and flush with the side surface of the magnet to serve as a side surface electrode.

[0024] Specifically, please refer to Figure 1 , Figure 1is a structural diagram of an inductor structure provided by the present application. The inductor structure provided by the present application includes a magnet 100 and a coil 200 disposed inside the magnet 100, and two ends of the coil 200 form a first folded leg and a second folded leg, respectively. The first folded leg and the second folded leg can be located in the same plane of the magnet 100. The first folded leg and the second folded leg each include a bottom surface portion 210 and a side surface portion 220. The bottom surface portion 210 of the first folded leg and the second folded leg is exposed outside the magnet 100 and flush with the bottom surface of the magnet 100 to serve as a bottom surface electrode. The side surface portion 220 of the first folded leg and the second folded leg is exposed outside the magnet 100 and flush with the side surface of the magnet 100 to serve as a side surface electrode.

[0025] The magnet 100 provides a necessary magnetic circuit for the inductor structure. The material of the magnet 100 can include, for example, iron (such as pure iron powder), iron alloy (alloy powder based on Fe-Si, Fe-Si-Al, Fe-Ni, Fe-Ni-Mo, Fe-Ni-Mo-Cu, Fe-Co, Fe-Ni-Co, Fe-Cr, Fe-Cr-Si, Fe-Ni-Cr, Fe-Cr-Al, etc.), amorphous alloy such as Fe-based amorphous alloy, Co-based amorphous alloy, etc., spinel ferrite such as ferrite based on Mg-Zn, Mn-Zn, Mn-Mg, Cu-Zn, Mg-Mn-Sr, Ni-Zn, etc., hexagonal ferrite such as ferrite based on Ba-Zn, Ba-Mg, Ba-Ni, Ba-Co-based, Ba-Ni-Co, etc., or garnet ferrite such as Y-based ferrite. The material of the magnet 100 can also be a magnetic material resin composite in which metal magnetic powder particles and a resin mixture are mixed with each other. The metal magnetic powder particles can include iron (Fe), chromium (Cr), or silicon (Si) as a main component. For example, the metal magnetic powder particles can include Fe-Ni, Fe, Fe-Cr-Si, etc. The resin mixture can include epoxy resin, polyimide, liquid crystal polymer (LCP), etc., but is not limited thereto.

[0026] The coil 200 is wound by a wire, and a magnetic field is generated around the coil when current passes through the coil. The coil 200 is generally made of a metal conductor, such as copper, silver, tin, chromium, aluminum, etc. The coil 200 can specifically include multiple electrode coil layers, and a dielectric layer can be further coated on the coil 200, which can completely wrap the coil 200, or the dielectric layer and the electrode coil layer are alternately stacked therebetween, and the direction of the dielectric layer and the electrode coil layer is the thickness direction of the coil 200. In this inductance structure, the coil is arranged inside the magnet, and through this arrangement, the inductance not only enables the bottom electrode to be welded with the pad, but also enables the side electrode to participate in welding, thereby increasing the welding area and improving the welding strength. It should be noted that the coil 200 described above can be a flat coil or a circular coil, and can also be an elliptical coil, and the present embodiment will not be further described.

[0027] Further, please continue to refer to Figure 2 In this embodiment, the coil 200 extends from one end of the top surface of the magnet 100 to the bottom surface of the magnet 100, and the other end of the coil 200 forms a first folded leg and a second folded leg, respectively, and the first folded leg and the second folded leg are exposed on the bottom surface of the magnet 100.

[0028] In an embodiment, the magnet 100 has a hexahedral structure, and the side surface of the magnet 100 can further include a notch 110, as shown in Figure 1 so that the side portions 220 of the first folded leg and the second folded leg are exposed outside the magnet 100 through the notch 110. The width of the notch 110 can be the same as the width of the side surface of the magnet 100, the length of the notch 110 can be less than or equal to the length of the side portions 220 of the first folded leg and the second folded leg, and the depth of the notch 110 can be between 0.1-0.3 mm. The side electrode, i.e., the side portions 220 of the first folded leg and the second folded leg, is arranged inside the magnet 100, and accordingly, the surface-to-surface distance between the side electrode surface and the surface of the side surface of the magnet 100 is also between 0.1-0.3 mm.

[0029] Specifically, the notch 110 described above can be formed by cutting part of the magnet after the inductance structure including the side electrode is integrally formed. For example, a cutter can be used to cut the integrally formed inductance, and the size of the cutter blade is selected according to the size of the inductance, and the purpose is to separate part of the magnet to ensure that the side portions 220 of the first folded leg and the second folded leg inside the magnet 100 are exposed to form the side electrode.

[0030] Further, the part of the coil 200 inside the magnet 100 includes a coil body and a varnish film covering the outer surface of the coil body to insulate the coil body from the magnet 100. The varnish film covering the outer surface of the coil body is used to isolate the coil body from the magnet 100. The varnish film isolates the coil body from the magnet 100, thereby avoiding current interference between the coil 200 and the magnet 100, avoiding magnetic saturation of the magnet 100, and ensuring the reliability of the inductor. In addition, the above-mentioned varnish film has not only insulation performance but also high-temperature resistance performance. First, the coil body generates heat due to the current during operation. Second, when the inductor is assembled to the PCB circuit board, the inductor can be fixed to the circuit board using a soldering process, which generates high heat. Therefore, the varnish film has strong high-temperature resistance performance, which can further improve the reliability of the inductor.

[0031] Further, for the part of the coil 200 not inside the magnet 100, that is, the first and second folded legs of the coil 100, the varnish film is removed and metallized to form a bottom electrode and a side electrode, thereby obtaining an inductor component product. The electrode formed by metallization can be PVD, electroplating, or tin immersion, etc. For the first and second folded legs exposed outside the magnet 100, the folded copper wire can be peeled (such as the outer film of the enameled copper wire) by laser or polishing to expose the copper wire base, that is, the conductive part, which is directly used as the bottom electrode and the side electrode of the inductor component after metallization.

[0032] In an embodiment, the side part of the first and second folded legs of the coil 200 can include a first side part and a second side part located on opposite sides of the magnet 100, respectively, such as forming a bottom electrode on the bottom surface of the magnet 100 and two side electrodes on the opposite sides adjacent to the bottom surface. Correspondingly, at this time, the opposite sides of the magnet 100 each include a notch for exposing the side electrodes on the two sides of the magnet.

[0033] The inductor structure provided by the embodiment includes side electrodes, which can be tinned on the side electrodes after SMD welding to the pads, so that the appearance AOI can evaluate the welding effect by the tinning effect on the side, as shown in Figure 3 At the same time, compared with the bottom welding structure, the inductor provided by the embodiment has a larger area with the PCB, which makes the welding strength stronger.

[0034] The above only describes the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the specification and drawings, such as the mutual combination of technical features between embodiments, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. An inductive structure comprising a side electrode, characterized in that, The inductor comprises a magnet and a coil disposed inside the magnet, two ends of the coil form a first folded leg and a second folded leg respectively, the first folded leg and the second folded leg each comprise a bottom surface part and a side surface part, the bottom surface parts of the first folded leg and the second folded leg are exposed outside the magnet and flush with the bottom surface of the magnet to serve as bottom surface electrodes, and the side surface parts of the first folded leg and the second folded leg are exposed outside the magnet and flush with the side surface of the magnet to serve as side surface electrodes.

2. The inductive structure comprising side electrodes according to claim 1, characterized in that, The coil extends from one end of the top surface of the magnet to the bottom surface of the magnet, and the other end of the coil forms the first folded leg and the second folded leg respectively.

3. The inductive structure comprising side electrodes according to claim 1, characterized in that, The magnet has a hexahedral structure, and the side surface of the magnet comprises a notch, and the side surface parts of the first folded leg and the second folded leg are exposed outside the magnet through the notch.

4. The inductor structure comprising side electrodes according to claim 3, characterized in that, The width of the notch is the same as the width of the side surface of the magnet, the length of the notch is less than or equal to the length of the side surface parts of the first folded leg and the second folded leg, and the depth of the notch is between 0.1-0.3mm.

5. The inductor structure comprising side electrodes according to claim 3, characterized in that, The inductor structure comprising the side surface electrodes is formed by cutting off part of the magnet after being integrally formed.

6. The inductor structure comprising side electrodes according to claim 1, characterized in that, The coil is a flat coil or a circular coil.

7. The inductor structure comprising side electrodes according to claim 1, characterized in that, The part of the coil inside the magnet comprises a coil body and a lacquer film, the lacquer film is coated on the outer surface of the coil body to insulate the coil body from the magnet.

8. The inductive structure comprising side electrodes according to claim 7, characterized in that, The first folded leg and the second folded leg of the coil are subjected to lacquer film removal and metallization treatment to form the bottom surface electrodes and the side surface electrodes.

9. The inductive structure comprising side electrodes according to claim 8, characterized in that, The metallization treatment includes PVD, electroplating or tin immersion.

10. The inductor structure comprising side electrodes according to claim 1, characterized in that, The side surface parts of the first folded leg and the second folded leg comprise a first side surface part and a second side surface part respectively located on opposite sides of the magnet.

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