Inductive component and method for manufacturing the same

Abstract

The application provides an inductance component and a manufacturing method thereof. The single end electrode comprises two separated parts, i.e., a first part and a second part, and the first part and the second part are oppositely arranged, wherein at least one is connected with the leading end corresponding to the electromagnetic coil. That is, by separating the design of the single end electrode, the parasitic capacitance generated by the single end electrode and the electromagnetic coil inside the product is reduced, so that the self-resonant frequency of the inductance component can be improved under the premise of ensuring the welding property.

Description

Technical Field

[0001] This application relates to the field of inductor technology, specifically to an inductor component and its manufacturing method. Background Technology

[0002] With the application of 5G and the research and development of 6G, the communications industry is constantly moving towards higher frequencies. This inevitably places high demands on the performance of electronic components at high frequencies, with inductors being particularly important. The terminal electrodes (also known as terminals) of inductors serve to solder to the circuit board, and their shape affects the product's performance. Different terminal electrode designs directly impact the main performance characteristics of inductors, such as inductance, Q value, and self-resonant frequency.

[0003] Inductor components mainly consist of three parts: the insulating frame, the inductor coil (also known as an electromagnetic coil), and the terminal electrodes that connect to the external system. The terminal electrodes are responsible for the physical connection to the external system and for forming a conductive circuit. They also limit the operation of the electromagnetic coil, thus affecting the product's performance. There are three main types of terminal electrode designs commonly found on the market:

[0004] 1. The terminal electrodes are a continuous structure, located only on the bottom surface of the inductor and symmetrically distributed. This design of the terminal electrodes can improve the self-resonant frequency of the inductor, but it has poor solderability.

[0005] 2. A single terminal electrode has a continuous structure, located on the bottom surface of the inductor and extending to one side. Two terminal electrodes are located on the bottom surface and opposite two sides of the inductor, and are symmetrically distributed. The self-resonant frequency of the product with this terminal electrode design will be reduced, and the solderability is generally poor.

[0006] 3. The end electrodes are a continuous structure, located on two opposite sides of the inductor. Each end electrode also extends to the top and bottom surfaces of the inductor and is symmetrically distributed. This end electrode design significantly reduces the self-resonant frequency of the product, but provides good solderability. Summary of the Invention

[0007] In view of this, this application provides an inductor and a method for manufacturing the same, which can improve the self-resonant frequency of the inductor while ensuring solderability.

[0008] This application provides an inductor component, comprising:

[0009] An electromagnetic coil includes two leads that serve as the current input and current output terminals, respectively.

[0010] Two terminal electrodes are connected to the current input terminal and the current output terminal, respectively. Each terminal electrode includes a first part and a second part, which are arranged opposite to each other along a first direction, and at least one of them is connected to the lead-out terminal corresponding to the electromagnetic coil.

[0011] Optionally, the inductor includes multiple inner electrodes and multiple insulating layers, which are stacked alternately along the first direction. The multiple inner electrodes are connected end to end to form the electromagnetic coil. The first part and the second part of a single end electrode both include multiple sub-parts, and each sub-part is located on the side of the corresponding insulating layer.

[0012] Optionally, the sub-parts are disposed on two vertically connected sides corresponding to the insulating layer.

[0013] Optionally, the sub-parts of a single terminal electrode and the inner electrode of the corresponding layer can be obtained using the same process.

[0014] Optionally, the inductor includes a second cover plate and a first cover plate disposed opposite to each other along the first direction, and the plurality of inner electrodes and the plurality of insulating layers are disposed between the first cover plate and the second cover plate; wherein one of the end electrodes is disposed on the side of the plurality of insulating layers closest to the first cover plate and is connected to an inner electrode closest to the first cover plate; and another end electrode is disposed on the side of the plurality of insulating layers closest to the second cover plate and is connected to an inner electrode closest to the second cover plate.

[0015] Optionally, both the first part and the second part include the three layers of sub-parts.

[0016] Optionally, the first portion and the second portion are arranged symmetrically along an axis parallel to a second direction, the second direction being perpendicular to the first direction.

[0017] Optionally, the width of the first part and the second part is a, the width of the inductor is W, and a≤0.25*W; the height of the first part and the second part is b, the width of the inductor is T, and b≤0.5*T; the distance between the first part and the second part is c, and c≥2a.

[0018] This application provides a method for manufacturing an inductor, comprising:

[0019] Provide the first cover plate;

[0020] Multiple insulating layers and multiple inner electrodes are formed on the first cover plate in a sequentially alternating manner along a first direction, and the multiple inner electrodes are connected end to end in sequence to form an electromagnetic coil.

[0021] The plurality of insulating layers and the plurality of inner electrodes form an electrode layer, and a second cover plate is formed on the electrode layer;

[0022] Two terminal electrodes are formed on opposite sides of the inductor, respectively connected to the lead-out terminals of the first inner electrode and the last inner electrode along the first direction; wherein, a single terminal electrode includes a first part and a second part, the first part and the second part are arranged opposite to each other along the first direction, and at least one of them is connected to the lead-out terminal corresponding to the electromagnetic coil.

[0023] Optionally, two terminal electrodes are formed, including:

[0024] An electroplating process is performed on the predetermined outer surface of the inductor to form an electroplating layer. The electroplating layer covers the sides of a plurality of insulating layers closest to the first cover plate and is connected to an inner electrode closest to the first cover plate. Another end electrode is disposed on the sides of a plurality of insulating layers closest to the second cover plate and is connected to an inner electrode closest to the second cover plate.

[0025] As described above, the single terminal electrode of this application is designed to include a first part and a second part, which are arranged opposite to each other, and at least one of them is connected to the lead-out terminal corresponding to the electromagnetic coil. In other words, by designing the single terminal electrode separately, the parasitic capacitance generated by the single terminal electrode and the electromagnetic coil inside the product is reduced, and the self-resonant frequency of the inductor can be improved while ensuring solderability. Attached Figure Description

[0026] Figure 1 This is a front view of the structure of an inductor provided in an embodiment of this application;

[0027] Figure 2 This is a side view of the structure of an inductor provided in an embodiment of this application;

[0028] Figure 3 This is an exploded view of the structure of an inductor provided in an embodiment of this application;

[0029] Figure 4 This is a schematic flowchart of a method for manufacturing an inductor component provided in an embodiment of this application. Detailed Implementation

[0030] This application designs the individual terminal electrodes of the inductor separately. For example, a single terminal electrode is set as a first part and a second part that are set opposite to each other. The so-called relative setting can be understood as the two not being in contact, that is, having a minimum value that is not equal to zero. This reduces the parasitic capacitance generated by the single terminal electrode and the electromagnetic coil, and improves the self-resonant frequency of the inductor while ensuring solderability.

[0031] The terms "first part" and "second part" can be understood as a difference in quantity, such as a single end electrode being configured as two parts; or as a difference in type, such as a single end electrode being configured as two types, one connected to the electromagnetic coil and the other not connected to the electromagnetic coil. In this case, the number of the first part and the second part may not be one, meaning that a single end electrode can be separated into two or more parts. For ease of description, this application will hereinafter describe each of the first part and the second part as one.

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly described below in conjunction with specific embodiments and corresponding drawings. Obviously, the embodiments described below are only a part of the embodiments of this application, and not all of them. Unless otherwise specified, the following embodiments and their technical features can be combined with each other, and also belong to the technical solutions of this application.

[0033] In the description of the embodiments of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solutions of the corresponding embodiments, and are not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this application.

[0034] Please refer to the following: Figures 1 to 3 The diagram shows a schematic diagram of the structure of an inductor provided in this application, as well as a partial schematic diagram. The inductor 1 includes a first cover plate 111, a second cover plate 112, multiple internal electrodes 12, two terminal electrodes 13, and multiple insulating layers 14.

[0035] The shape and size of the frame body 10 of the inductor component 1 are not limited in this embodiment; for example, the shape can be... Figures 1 to 3 The examples shown are cuboids, rectangles, or other similar tetrahedral shapes. It should be noted that... Figure 3 The diagram shows a portion of the inductor component 1, specifically only a part of the structure where the internal electrodes 12 and insulating layers 14 are combined, without showing the full number of internal electrodes 12 and insulating layers 14. The number of internal electrodes 12 and insulating layers 14 can be the same; the specific number can be determined according to actual needs and is not limited in this application. This document uses... Figure 3 The following description uses the 10 insulating layers 14 and 10 inner electrodes 12 shown as an example. Along the first direction x, these 10 inner electrodes 12 are respectively labeled C0 to C9.

[0036] The width direction of inductor 1 is the first direction x, the height direction is the second direction y, and the length direction is the third direction z. The first direction x, the second direction y, and the third direction z are all perpendicular to each other and can be regarded as the three coordinate axes of a three-dimensional rectangular coordinate system. For the overall cubic structure design, it has a first surface 1a, a second surface 1b, and four sides 1c1 to 1c4. The second surface 1b and the first surface 1a are arranged opposite each other along the second direction y, so they can also be referred to as the upper surface and lower surface of inductor 1, respectively. The four sides 1c1 to 1c4 are arranged opposite each other and connected end to end between the first surface 1a and the second surface 1b. Side 1c1 and side 1c3 are arranged opposite each other along the third direction z, and side 1c2 and side 1c4 are arranged opposite each other along the first direction x.

[0037] It should be understood that the term "perpendicular" throughout this application does not require the included angle between the two directions to be exactly 90°, but rather allows for a deviation of ±10°. In other words, "perpendicular" can be understood as an angle between any two directions ranging from 80° to 100°. Similarly, the term "parallel" throughout this application does not require the included angle between the two directions to be exactly 0° or 180°, but rather allows for a deviation of ±10°. In other words, "parallel" can be understood as an angle between any two directions ranging from 0° to 10° or from 170° to 190°.

[0038] The first cover plate 111 and the second cover plate 112 can also be referred to as the lower cover plate and the upper cover plate, respectively. They belong to the cover plate layer of the inductor 1 and together form the housing of the inductor 1. The shape and size of the two are adapted to the shape and size of the inductor 1. This not only limits the appearance of the inductor 1, but also protects the internal structural components of the inductor 1, such as the internal electrodes 12 and the insulating layer 14.

[0039] The first cover plate 111 and the second cover plate 112 (along the second direction y) can have equal thicknesses and be made of the same material, such as ferrite. Either the first cover plate 111 or the second cover plate 112 can be a single-layer structure or a multi-layer structure, for example... Figure 3 As shown, both the first cover plate 111 and the second cover plate 112 are three-layer structures.

[0040] The inner electrode 12 and the insulating layer 14 form the electrode layer of the inductor 1, and are disposed between the first cover plate 111 and the second cover plate 112, and are alternately stacked along the first direction x. Figure 3 Taking the 10 insulating layers 14 and 10 inner electrodes 12 shown as an example, the first insulating layer 14 is provided on the first cover plate 111, the first inner electrode C0 is provided on the first insulating layer 14, the second insulating layer 14 is provided on the first inner electrode C0, the second inner electrode C1 is provided on the second insulating layer 14, and so on.

[0041] The insulating layer 14 can cooperate with the first cover plate 111 and the second cover plate 112 to form the frame body 10 of the inductor device 1. The insulating layer 14 can be made of the same material as the first cover plate 111 and the second cover plate 112, such as a ferrite material. The insulating layer 14 can also be made of a semiconductor material with nonlinear characteristics, such as multiple cast ceramic films stacked together. The main component can be zinc oxide (ZnO), and it contains oxides of at least one of the secondary components that form nonlinear characteristics, such as Bi2O3, Co2O3, MnO2, Sb2O3, TiO2, Cr2O3, Ni2O3, etc., such as Bi2O3, Co2O3, MnO2, Sb2O3, TiO2, Cr2O3, Ni2O3, etc.

[0042] Each internal electrode 12 can be arranged in a strip shape, for example, made of a metal or alloy material with high conductivity such as copper or silver. The width and length of the electrode strip can be adaptively set according to actual needs. The figure shown is only an example and is not limited in the embodiments of this application.

[0043] Multiple internal electrodes 12 are connected end-to-end in sequence to form the electromagnetic coil of the inductor 1. Specifically, the insulating layer 14 between two adjacent internal electrodes 12 has through holes, which are filled with conductive material (e.g., the conductive material forming the upper layer of internal electrodes 12) and cured to form conductive pillars, thereby connecting two adjacent internal electrodes 12 end-to-end. Figure 3 Taking the 10 insulating layers 14 and 10 inner electrodes 12 shown as an example, along the second direction y, the first inner electrode C0 and the second inner electrode C1 are connected by a conductive post N0 that penetrates the second insulating layer 14, the second inner electrode C1 and the third inner electrode C2 are connected by a conductive post N1 that penetrates the second insulating layer 14, and so on.

[0044] The leads of the first inner electrode C0 and the last inner electrode C9 extend toward the two end electrodes 13 respectively and are connected to the two end electrodes 13 respectively; the so-called lead can be understood as the end that is not connected to other inner electrodes 12, that is, the current input end and the current output end of the electromagnetic coil.

[0045] The two terminal electrodes 13 are respectively connected to the current input terminal and the current output terminal of the electromagnetic coil, as follows: Figures 1 to 3 As shown, a single end electrode 13 includes a first portion 131 and a second portion 132, which are symmetrically arranged along an axis parallel to the second direction y, and are arranged opposite to each other along the first direction x, with at least one of them connected to a lead-out terminal corresponding to an electromagnetic coil. For example, in Figure 3 In the scene shown, the first part 131 of the lower electrode 13 ( Figure 3The lead-out terminal corresponding to the electromagnetic coil is connected to the terminal labeled L2, and the second part 132 of this terminal electrode 13 ( Figure 3 The part labeled R2 is not connected to the electromagnetic coil; the second part 132 of the upper electrode 13 ( Figure 3 The lead-out terminal corresponding to the electromagnetic coil is connected to the terminal labeled R1, and the first part 131 of this terminal electrode 13 ( Figure 3 The part labeled L1 was not connected to the electromagnetic coil.

[0046] The first part 131 and the second part 132 are two independent parts of a single terminal electrode 13, and they are not connected to each other. This is equivalent to the present application designing each terminal electrode 13 of the inductor 1 separately, thereby reducing the parasitic capacitance generated by the single terminal electrode 13 and the electromagnetic coil, thereby increasing the self-resonant frequency of the inductor 1 while ensuring solderability.

[0047] In other scenarios, the first portion 131 and the second portion 132 of a single end electrode 13 can both be connected to the corresponding lead-out end of the electromagnetic coil. For example, the single lead-out end of the electromagnetic coil may be forked into two parts, one part extending toward and connecting to the first portion 131, and the other part extending toward and connecting to the second portion 132. Alternatively, the first portion 131 and the second portion 132 of one end electrode 13 may both be connected to the corresponding lead-out end of the electromagnetic coil, while only the first portion 131 or the second portion 132 of the other end electrode 13 may be connected to the corresponding lead-out end of the electromagnetic coil.

[0048] In some practical scenarios, the first part 131 and the second part 132 of a single end electrode 13 may both include multiple sub-parts, each sub-part located to the side of the corresponding insulating layer 14.

[0049] One end electrode 13 is disposed on the side of the plurality of insulating layers 14 closest to the first cover plate 111 and is connected to an inner electrode 12 closest to the first cover plate 111; the other end electrode 13 is disposed on the side of the plurality of insulating layers 14 closest to the second cover plate 112 and is connected to an inner electrode 12 closest to the second cover plate 112. Correspondingly, sub-parts are disposed on two vertically connected sides of the corresponding insulating layers 14, so as to... Figure 3Taking the three-layer sub-parts shown as an example, the first part 131 of one end electrode 13 includes three-layer sub-parts L1, which are disposed on two vertically connected sides of the corresponding insulating layer (i.e., the insulating layer where the inner electrodes C7 to C9 are located) 14. The second part 132 includes three-layer sub-parts R1, which are also disposed on two vertically connected sides of the corresponding insulating layer (i.e., the insulating layer where the inner electrodes C7 to C9 are located) 14. Sub-parts L1 and R1 located in the same layer are arranged opposite each other along the third direction z and are symmetrically arranged along an axis parallel to the second direction y. The first part 131 of the other end electrode 13 includes three-layer sub-parts L2, which are disposed on two vertically connected sides of the corresponding insulating layer (i.e., the insulating layer where the inner electrodes C0 to C2 are located) 14. The second part 132 includes three-layer sub-parts R2, which are also disposed on two vertically connected sides of the corresponding insulating layer (i.e., the insulating layer where the inner electrodes C0 to C2 are located) 14. Sub-parts L2 and R2 located in the same layer are arranged opposite each other along the third direction z and are symmetrically arranged along an axis parallel to the second direction y.

[0050] The sub-parts of the terminal electrode 13 can be made of the same material as the inner electrode 12 of the same layer, such as highly conductive metals or alloys like copper or silver. In this way, each sub-part and the inner electrode 12 of the same layer can be obtained through the same process (e.g., the same forming and sintering process), reducing the number of processes and simplifying the manufacturing process. The sub-parts can be less than or equal to the width of the inner electrode 12. Of course, the materials used for each sub-part and the inner electrode 12 of the same layer can also be different. The materials used can be determined according to actual needs and the adaptability of the structural function characteristics; these are not listed individually in the embodiments of this application.

[0051] Optionally, an electroplated layer (not shown) can be formed on the outer surface of the inductor 1. The distance between two adjacent sub-layers is very small. During the electroplating surface treatment process, metal ions are deposited and cover the two adjacent sub-layers, extending and filling the space between them to form a connection. For example, [the following text is incomplete and requires further context to translate accurately]. Figure 3 The three sub-layers L1 are interconnected, the three sub-layers R1 are interconnected, the three sub-layers L2 are interconnected, and the three sub-layers R2 are interconnected. From an external perspective, planar portions of the terminal electrodes 13 are formed on the corresponding outer surfaces.

[0052] The dimensions of each part of the terminal electrode 13 can be determined according to actual needs. For example, the width of the first part 131 and the second part 132 is a, the width of the inductor 1 is W, and a≤0.25*W, where the width is the length along the first direction x; the height of the first part 131 and the second part 132 is b, the height of the inductor 1 is T, and b≤0.5*T, where the height is the length along the second direction y; the distance between the first part 131 and the second part 132 is c, and c≥2a.

[0053] This application also provides a method for manufacturing an inductor, which can be used to manufacture the inductor 1 of any of the foregoing embodiments. For example... Figure 4 As shown, the method includes the following steps S11 to S14.

[0054] S11, Provide the first cover plate.

[0055] S12. Multiple insulating layers and multiple inner electrodes are formed on the first cover plate in a first direction and are alternately stacked. The multiple inner electrodes are connected end to end in sequence to form an electromagnetic coil.

[0056] S13, multiple insulating layers and multiple inner electrodes form an electrode layer, and a second cover plate is formed on the electrode layer.

[0057] S14. Two terminal electrodes are formed on opposite sides of the inductor, respectively connected to the lead-out terminals of the first inner electrode and the last inner electrode along the first direction; wherein, a single terminal electrode includes a first part and a second part, the first part and the second part are arranged opposite to each other along the first direction, and at least one of them is connected to the lead-out terminal corresponding to the electromagnetic coil.

[0058] Although step designations such as S11 and S12 are used, their purpose is to more clearly and concisely describe the corresponding content and do not constitute a substantial restriction on the order. In specific implementation, those skilled in the art may, for example, execute S14 first and then S13, etc., and these should all be within the scope of protection of this application.

[0059] In scenarios where the first and second parts of a single end electrode include multiple sub-parts, a sub-part can be formed simultaneously on the side of the same insulating layer when forming an inner electrode on the same insulating layer during the process of forming multiple insulating layers and multiple inner electrodes that are stacked alternately in sequence. This can reduce the number of processes and simplify the process.

[0060] Each sub-part formed synchronously with the inner electrode has conductive properties. Therefore, step S14 of forming the terminal electrode in this application may further include: performing electroplating on a predetermined outer surface of the inductor (i.e., the surface closest to the multilayer sub-parts) to form an electroplated layer. For example, Ni plating and Sn plating are sequentially formed on the previously formed terminal electrode surface to obtain the final outer electrode (i.e., the terminal electrode). Since the distance between two adjacent sub-parts is very small, metal ions will cover the two adjacent sub-parts during the electroplating surface treatment process and extend to fill the space between the two adjacent sub-parts to form a connection. For example, it extends to the side of each insulating layer located on the predetermined outer surface, thereby connecting the sub-parts to each other.

[0061] It should be understood that the manufacturing process described in steps S11 to S14 above is only a general description. In actual manufacturing scenarios, the specific implementation details of each step can be found in existing technologies. For example, the entire multilayer chip inductor can be manufactured using processes such as molding, cutting, glue removal and sintering, chamfering, and electroplating.

[0062] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. For those skilled in the art, any equivalent structural transformations made using the content of this specification and drawings are similarly included within the patent protection scope of this application.

[0063] Although this document uses terms such as "first," "second," etc., to describe various types of information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. Furthermore, the singular forms "a," "an," and "the" are intended to also include the plural forms. The terms "or" and "and / or" are interpreted as inclusive, or meaning either one or any combination. Exceptions to this definition only arise when combinations of elements, functions, steps, or operations are inherently mutually exclusive in some way.

Claims

1. An inductive component, characterized in that, include: An electromagnetic coil includes two leads that serve as the current input and current output terminals, respectively. Two end electrodes are respectively connected to the current input terminal and the current output terminal. Each end electrode includes a first part and a second part. The first part and the second part are arranged opposite to each other along a first direction and are not connected to each other, forming two independent parts of a single end electrode. At least one of them is connected to the lead-out terminal corresponding to the electromagnetic coil. The inductor includes multiple internal electrodes and multiple insulating layers, which are stacked alternately along the first direction. The multiple internal electrodes are connected end to end to form the electromagnetic coil. The main component of the insulating layer is zinc oxide (ZnO), and it contains oxides of at least one of the following secondary components that form nonlinear characteristics: bismuth (Bi), cobalt (Co), titanium (Ti), nickel (Ni), manganese (Mn), chromium (Cr), and antimony (Sb). The first and second portions of each of the single end electrodes each include multiple sub-portions, each sub-portion being located on the side of the corresponding insulating layer, and at least one insulating layer between the sub-portions of the two end electrodes is not provided with a sub-portion on its side.

2. The inductor component according to claim 1, characterized in that, The sub-parts are disposed on two vertically connected sides corresponding to the insulating layer.

3. The inductor component according to claim 1, characterized in that, The sub-parts of a single terminal electrode and the inner electrode of the corresponding layer can be obtained using the same process.

4. The inductor component according to claim 1, characterized in that, The inductor component includes a first cover plate and a second cover plate disposed opposite to each other along the first direction, and the plurality of internal electrodes and the plurality of insulating layers are disposed between the first cover plate and the second cover plate; One of the end electrodes is disposed on the side of the plurality of insulating layers closest to the first cover plate and is connected to an inner electrode closest to the first cover plate; the other end electrode is disposed on the side of the plurality of insulating layers closest to the second cover plate and is connected to an inner electrode closest to the second cover plate.

5. The inductor component according to claim 4, characterized in that, Both the first part and the second part include the three layers of sub-parts.

6. The inductive component according to any one of claims 1 to 5, characterized in that, The first part and the second part are arranged symmetrically along an axis parallel to a second direction, which is perpendicular to the first direction.

7. The inductor component according to claim 1, characterized in that, The width of the first part and the second part is a, the width of the inductor is W, and a≤0.25*W; the height of the first part and the second part is b, the width of the inductor is T, and b≤0.5*T; the distance between the first part and the second part is c, and c≥2a.

8. A method for manufacturing an inductive component, characterized in that, include: Provide the first cover plate; Multiple insulating layers and multiple inner electrodes are formed on the first cover plate in alternating layers along the first direction. The multiple inner electrodes are connected end to end to form an electromagnetic coil. The main component of the insulating layer is zinc oxide (ZnO), and it contains at least one oxide of bismuth (Bi), cobalt (Co), titanium (Ti), nickel (Ni), manganese (Mn), chromium (Cr), antimony (Sb), etc., which form nonlinear components. The plurality of insulating layers and the plurality of inner electrodes form an electrode layer, and a second cover plate is formed on the electrode layer; Two terminal electrodes are formed on opposite sides of the inductor, respectively connected to the lead-out terminals of the first inner electrode and the last inner electrode along the first direction; wherein, a single terminal electrode includes a first part and a second part, the first part and the second part are arranged opposite to each other along the first direction, and are not connected to each other and are two independent parts of a single terminal electrode, wherein at least one of them is connected to the lead-out terminal corresponding to the electromagnetic coil. Both the first part and the second part include multiple sub-parts, each of which is located on the side of the corresponding insulating layer. Between the sub-parts of the two end electrodes, at least one insulating layer is not provided on the side of the sub-part.

9. The method according to claim 8, characterized in that, Two end electrodes are formed, including: An electroplating process is performed on the predetermined outer surface of the inductor to form an electroplating layer. The electroplating layer covers the sides of a plurality of insulating layers closest to the first cover plate and is connected to an inner electrode closest to the first cover plate. Another end electrode is disposed on the sides of a plurality of insulating layers closest to the second cover plate and is connected to an inner electrode closest to the second cover plate.

Images