Inductor

Abstract

The utility model provides an inductor which comprises a magnetic core, an inductance coil and a shielding cover, and the magnetic core comprises a core seat and a magnetic column arranged on the core seat in a protruding mode. The inductance coil comprises a coil body and an insulating layer, the coil body comprises a coil portion and electrode portions, the coil portion is wound outside the magnetic column in the axial direction of the magnetic column, the electrode portions are connected to the two extending ends of the coil portion, the coil portion comprises a plurality of coil layers sequentially connected in the axial direction of the magnetic column, the coil layers surround the magnetic column, and the insulating layer is arranged between the coil layers. The insulating layer is arranged between every two adjacent coil layers, and each insulating layer comprises an isolating membrane and iron-silicon-aluminum powder filled in the isolating membrane; the shielding cover is connected to the core base and covers the coil body, and the two electrode parts extend out of the shielding cover. According to the inductor, the two adjacent coil parts are isolated through the insulating layers made of the iron-silicon-aluminum powder, so that the copper-iron co-fired inductor can form a plurality of coil layers, and the condition of short circuit is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of inductors, and in particular relates to an inductor. Background Art

[0002] When conventional one-piece molded inductors are molded, the bonding between magnetic powder and magnetic powder relies on the bonding effect of the resin. One-piece molded inductors are usually used in chip power modules due to their high saturation characteristics. They often work under large currents and are accompanied by a lot of heat. The temperature that traditional one-piece molded inductors that are molded by resin bonding can withstand during operation will be affected by the aging of the resin, and may decompose and smoke or lose strength, causing the inductor to break and fail. Therefore, in order to increase the operating temperature of the one-piece molded inductor so that it can work for a long time at a higher temperature and have a higher rated current, a copper-iron co-fired inductor can be used. After this inductor is formed, it is further sintered at a temperature of 600-900°C in a reducing atmosphere to discharge organic matter. The magnetic powders are reliably bonded together by the inorganic grain boundaries formed during sintering. In this way, the temperature that the inductor can withstand is higher than that of the inductor molded by magnetic powder bonding.

[0003] However, the copper wire in this copper-iron co-fired inductor must be sintered together with the formed magnetic powder, so the surface of the copper wire cannot be insulated with a paint film that cannot withstand high temperatures, so as to avoid direct contact between the upper and lower layers of the coil formed by the copper wire, which may cause the inductor to short-circuit. Currently, copper-iron co-fired inductors can only use a single-layer coil design, and cannot use a multi-layer coil design like an integrated inductor. However, the inductance range of this single-layer coil design inductor is greatly limited, and it is impossible to obtain a high inductance value under the premise of a small external size. Utility Model Content

[0004] The utility model aims to provide an inductor, aiming to solve the technical problem that the copper-iron co-fired inductor in the prior art cannot be coiled with copper wire.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] Provided is an inductor, comprising a magnetic core, an inductor coil and a shielding cover.

[0007] The magnetic core comprises a core seat and a magnetic column protruding from the core seat;

[0008] The inductor coil comprises a coil body and an insulating layer, wherein the coil body comprises a coil portion wound outside the magnetic column along the axial direction of the magnetic column and an electrode portion connected to two extended ends of the coil portion, the coil portion comprises a plurality of coil layers sequentially connected along the axial direction of the magnetic column, each of the coil layers surrounds the magnetic column, and the insulating layer is disposed between two adjacent coil layers, and the insulating layer comprises an isolation film and sendust powder filled in the isolation film;

[0009] The shielding cover is connected to the core seat and is arranged outside the coil body, and the two electrode parts extend outside the shielding cover.

[0010] As one of the embodiments, the Sendust powder is in the form of flakes.

[0011] As one of the implementation modes, the D50 specification of the Sendust powder is 3-5um.

[0012] As one of the embodiments, the insulating layer is disposed between the coil layer of the coil part closest to the core seat and the core seat.

[0013] As one of the implementation modes, the circumference of the insulating layer is equal to the circumference of the coil layer, and the width of the insulating layer is equal to the width of the coil layer.

[0014] As one of the implementation modes, an extension length of the insulating layer is equal to an extension length of the coil body.

[0015] As one of the embodiments, the coil portion has a first surface and a second surface that are opposite to each other, the first surface faces the core seat, and the insulating layer is formed on the first surface.

[0016] As one of the embodiments, the core seat has a first core surface and a second core surface facing each other, the magnetic column is protruded from the first core surface, and the two electrode parts extend to one side of the second core surface.

[0017] As one of the embodiments, the core seat also has a first side surface and a second side surface opposite to each other, the first side surface and the second side surface are both connected to the first core surface and the second core surface, the electrode portion includes a connecting section, a first bending section, a second bending section and a third bending section connected in sequence, the connecting section is connected to the connecting end of the coil body, the connecting section is located on one side of the first core surface, the first bending section is located on one side of the first side surface and is in contact with the first side surface, the second bending section is located on one side of the second core surface and is in contact with the second core surface, and the third bending section is located on one side of the second side surface and is in contact with the second side surface.

[0018] As one of the embodiments, a first protrusion is convexly provided on the first side surface, and a second protrusion is convexly provided on the second side surface. The first protrusion is located between the first bending sections of the two electrode parts, and the second protrusion is located between the third bending sections of the two electrode parts. The second bending sections of the two electrode parts are parallel.

[0019] The technical effect of the utility model compared with the prior art is: the inductor insulates the two adjacent coil layers of the coil body through the insulating layer made of sendustine powder. After the passivation treatment, a layer of stable oxide is generated on the surface of the sendustine powder, which can reduce or prevent the chemical reaction between the material and the environment (such as oxygen, moisture, chemicals, etc.), and has good insulation performance. At the same time, it has a high melting point and will not form grain annexation. In addition, the thermal deformation of the sendustine powder during the sintering process of the inductor also matches the magnetic core and will not form cracks. In this way, the copper-iron co-fired inductor can also form multiple coil layers, and there will be no short circuit. Compared with the one-piece molded inductor, the inductor can obtain a higher inductance value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments of the utility model or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a three-dimensional structural diagram of an inductor provided in an embodiment of the utility model;

[0022] Figure 2 yes Figure 1 A partial exploded view of the inductor in FIG.

[0023] Figure 3 yes Figure 1 Exploded diagram of the inductor coil and magnetic core in the inductor;

[0024] Figure 4 yes Figure 1 A partial cross-sectional view of the inductor coil in the inductor.

[0025] Description of reference numerals:

[0026] 10. Magnetic core; 101. First core surface; 102. Second core surface; 103. First side surface; 104. Second side surface; 11. Core seat; 111. First protrusion; 112. Second protrusion; 12. Magnetic column; 20. Inductor; 21. Coil body; 211. Coil portion; 2111. Coil layer; 212. Electrode portion; 2121. Connecting section; 2122. First bending section; 2123. Second bending section; 2124. Third bending section; 22. Insulating layer; 221. Isolation membrane; 222. Sendust powder; 30. Shielding cover; 31. Cover body; 32. Cover body; 301. Groove-shaped structure. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of the present invention, it should be understood that the terms "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] To facilitate the understanding of the readers, the following is an explanation of the terms used in this application:

[0032] Co-firing: After the electrode material and the functional material are formed and bonded together, they are placed in a furnace and heat treated at a temperature of more than 500°C in an air environment or a reducing atmosphere.

[0033] Soft magnetic metal powder: Generally, powders whose main element is iron have soft magnetic properties, including carbonyl iron powder, iron-based alloy powder, iron-based amorphous powder, etc.

[0034] One-piece molded inductor: An inductor in which the coil and magnetic powder are pressed together, and the coil is embedded in the magnetic powder after molding.

[0035] Copper-iron co-fired inductor: One or several types of soft magnetic metal powder are mixed with a small amount of resin to form granules, then pressed together with copper wire, placed in a furnace, and heat treated at 600-900℃ in a nitrogen, argon or hydrogen environment.

[0036] D50: Powder particle size parameter, specifically, the particle size corresponding to 50% of the cumulative distribution on the particle size distribution curve. In other words, when performing particle size analysis on Sendust 222, if 50% of the particles have a particle size less than or equal to a certain value, then this value is defined as D50, which is also known as the median diameter or average particle size. This means that among all the particles, half of the particles have a particle size less than or equal to D50, and the other half are greater than D50.

[0037] Coating method: the process of applying a substance (which may be a microorganism, coating material, stationary phase material, etc.) to the surface of another object in a uniform manner.

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0039] When conventional one-piece molded inductors are molded, the bonding between magnetic powder and magnetic powder relies on the bonding effect of the resin. One-piece molded inductors are usually used in chip power modules due to their high saturation characteristics. They often work under large currents and are accompanied by a lot of heat. The temperature that traditional one-piece molded inductors that are molded by resin bonding can withstand during operation will be affected by the aging of the resin, and may decompose and smoke or lose strength, causing the inductor to break and fail. Therefore, in order to increase the operating temperature of the one-piece molded inductor so that it can work for a long time at a higher temperature and have a higher rated current, a copper-iron co-fired inductor can be used. After this inductor is formed, it is further sintered at a temperature of 600-900°C in a reducing atmosphere to discharge organic matter. The magnetic powders are reliably bonded together by the inorganic grain boundaries formed during sintering. In this way, the temperature that the inductor can withstand is higher than that of the inductor molded by magnetic powder bonding.

[0040] However, the copper wire in this copper-iron co-fired inductor must be sintered together with the formed magnetic powder, so the surface of the copper wire cannot be insulated with a paint film that cannot withstand high temperatures, so as to avoid direct contact between the upper and lower layers of the coil formed by the copper wire, which may cause the inductor to short-circuit. Currently, copper-iron co-fired inductors can only use a single-layer coil design, and cannot use a multi-layer coil design like an integrated inductor. However, the inductance range of this single-layer coil design inductor is greatly limited, and it is impossible to obtain a high inductance value under the premise of a small external size.

[0041] To solve the above problems, the present invention provides an inductor. Figure 1 and Figure 2 The inductor includes a magnetic core 10 , an inductor coil 20 and a shielding cover 30 .

[0042] The magnetic core 10 includes a core base 11 and a magnetic column 12 protruding from the core base 11. The magnetic core 10 is used to enhance the magnetic flux density of the inductor 20. At least the magnetic column 12 is formed by pressing magnetic powder.

[0043] Specifically, please combine Figure 3 The core seat 11 has a first core surface 101 and a second core surface 102 facing each other, and the magnetic column 12 is protruded from the first core surface 101, wherein the axis of the magnetic column 12 can be perpendicular to the first core surface 101, and the magnetic core 10 forms a T-shaped structure. The magnetic column 12 is arranged in the middle of the first core surface 101, and the first core surface 101 and the second core surface 102 can be parallel to each other for easy processing.

[0044] The core base 11 and the magnetic column 12 can be integrally formed, that is, the core base 11 is also pressed and formed by magnetic powder, so as to facilitate the processing of the magnetic core 10. The magnetic core 10 can be made of one, two or three of amorphous powder, alloy powder and carbonyl iron powder coated with silicon dioxide, 3-5% polyvinyl butyral or polyethylene glycol by weight, 8-10% acetone, toluene or anhydrous ethanol, mixed and stirred, and granulated by a reciprocating granulator through a 40-150 mesh screen, and then the granulated particles are pressed and formed under a pressure of 20-60MPa. Among them, if the solute content of acetone, toluene or anhydrous ethanol is too much, the stirring time is too long, if it is too little, it is not easy to stir evenly, if the pressure is too small, the molding strength of the magnetic core 10 is too poor, and if it is too large, the molding density of the magnetic core 10 is too large, and the secondary molding and filling are not well combined.

[0045] See also Figure 2 The inductor 20 includes a coil body 21 and an insulating layer 22. The coil body 21 includes a coil portion 211 and an electrode portion 212. The coil portion 211 is axially wound outside the magnetic column 12. Two electrode portions 212 are provided. The two electrode portions 212 are respectively connected to the two extending ends of the coil portion 211.

[0046] In the illustrated embodiment, the coil body 21 is made of flat copper wire, wherein the portion spirally wound around the magnetic column 12 forms a coil portion 211, and the lead-out portions at the two extended ends form an electrode portion 212. The coil portion 211 is used to form an inductor, and the electrode portion 212 is used to connect to the circuit, wherein one extended end of the coil portion 211 is close to the core seat 11, and the other extended end is away from the core seat 11, one electrode portion 212 is used to connect to the positive pole of the external circuit, and the other electrode portion 212 is used to connect to the negative pole of the external circuit.

[0047] The coil portion 211 includes a plurality of coil layers 2111 sequentially connected along the axial direction of the magnetic column 12. Each coil layer 2111 surrounds the magnetic column 12 and is in a spiral shape. An insulating layer 22 is disposed between two adjacent coil layers 2111. Figure 4 The insulating layer 22 includes an isolation film 221 and sendust powder 222 filled in the isolation film 221. The insulating layer 22 can insulate the two adjacent coil layers 2111 through the sendust powder 222 to prevent the two adjacent coil layers 2111 from short-circuiting. The isolation film 221 is used to adhere the sendust powder 222 together to form a sheet structure, so as to be arranged between the two adjacent coil layers 2111.

[0048] Specifically, the coil portion 211 has a first surface and a second surface facing each other, the first surface of the coil layer 2111 faces the core base 11, and the second surface faces away from the core base 11. The direction from the first surface to the second surface of the coil portion 211 is the thickness direction of the coil portion 211, and the thickness direction of the isolation film 221 is the same as the thickness direction of the coil portion 211. Each coil portion 211 only surrounds the magnetic column 12 once, the first surface of one coil portion 211 of two adjacent coil portions 211 faces the second surface of the other coil portion 211, and the isolation film 221 is located between the first surface and the second surface facing each other of the two adjacent coil portions 211.

[0049] It should be noted that the isolation membrane 221 can be prepared and formed separately and then attached to the surface of the coil body 21, or the sendust powder 222 can be mixed into a fluid solvent to form a slurry, and then the mixed slurry is applied to the surface of the coil body 21. After the slurry solidifies, the isolation membrane 221 can be formed.

[0050] Specifically, 8-10% of polyvinyl butyral or polyethylene glycol by mass percentage of sendustine powder 222, 1-3% of dispersant (such as Triton X-100) by mass percentage of sendustine powder 222, 1-1.5% of dibutyl phthalate or butyl formate by mass percentage of sendustine powder 222, and 80-100% of acetone, toluene, or anhydrous ethanol by mass percentage of sendustine powder 222 are mixed and stirred in a sand mill for 3-6 hours, and then discharged to form the above-mentioned slurry. Among them, if there is too little sendustine powder 222 in the dispersant, the sendustine powder 222 cannot be dispersed in the dispersant and has poor fluidity. If there is too much, it is easy to cause flocculation. If there is too little sendustine powder 222 in dibutyl phthalate or butyl formate, the film is not easy to form. If there is too much, the film is easy to dry quickly. If there is too little sendustine powder 222 in acetone, toluene, or anhydrous ethanol, the fluidity is poor. If there is too much, it is too thin.

[0051] See also Figure 2 The shielding cover 30 is connected to the core base 11 and covers the outside of the coil body 21. The shielding cover 30 is used to limit the radiation of the magnetic field and / or electric field generated inside the inductor and prevent external electromagnetic interference (EMI) from entering the inside of the inductor, ensuring the working stability of the inductor and the surrounding electronic components are not interfered. Among them, the two electrode parts 212 extend outside the shielding cover 30 to facilitate access to external circuits.

[0052] At this time, the shielding cover 30 is also disposed outside the core base 11 , that is, the shielding cover 30 is disposed outside the inductor 20 and the magnetic core 10 to improve the shielding effect.

[0053] Specifically, the shielding cover 30 includes a cover body 31 and a cover body 32. The cover body 31 forms a slot-shaped structure 301. After the inductor 20 and the magnetic core 10 are connected, they are accommodated in the slot-shaped structure 301. The cover body 32 covers the notch of the slot-shaped structure 301. The shielding cover 30 can be wrapped around the inductor 20 and the magnetic core 10 by injection molding.

[0054] In other embodiments, the core base 11 may also be made of other materials, such as shielding materials. In this case, the core base 11 may serve as a part of the shielding cover 30 .

[0055] The inductor uses an insulating layer 22 made of aluminum silicon powder 222 to insulate the two adjacent coil layers 2111 of the coil body 21. After the passivation treatment, the aluminum silicon powder 222 forms a layer of stable oxide on its surface, which can reduce or prevent the chemical reaction between the material and the environment (such as oxygen, moisture, chemicals, etc.), and has good insulation performance. At the same time, it has a high melting point and will not form grain annexation. In addition, the aluminum silicon powder 222 will also match the magnetic core 10 when it is thermally deformed during the sintering process of the inductor, and will not form cracks. In this way, the copper-iron co-fired inductor can also form multiple coil layers 2111, and there will be no short circuit. Compared with the one-piece molded inductor, the inductor can obtain a higher inductance value.

[0056] In some embodiments, see Figure 4 The sendust powder 222 is in the form of flakes. When filled into the isolation membrane 221, the sendust powder 222 can be parallel or approximately parallel to the flake structure formed by the insulating layer 22. There can be multiple overlapping flake sendust powders 222 in the thickness direction of the isolation membrane 221 to ensure that the insulating layer 22 can achieve insulation effect in all areas and avoid gaps. When coating the slurry for preparing the isolation membrane 221, the flake morphology of the sendust powder 222 can be covered on the surface of the coil body 21 in a natural orientation, thereby effectively preventing direct contact between two adjacent coil layers 2111 and avoiding short circuits.

[0057] In some embodiments, the D50 specification of the flaky sendust powder 222 is 3-5um. If the D50 of the sendust powder 222 is too fine, it cannot be dispersed in the fluid solvent that forms the isolation membrane 221. If the D50 of the sendust powder 222 is too coarse, the slurry has poor fluidity and is not convenient for coating on the coil body 21.

[0058] In some embodiments, see Figure 3 An insulating layer 22 is provided between the coil layer 2111 of the coil part 211 closest to the core seat 11 and the core seat 11, so that the slurry of the insulating layer 22 can be applied to the entire coil part 211 for easy processing.

[0059] In some embodiments, the circumference of the insulating layer 22 is equal to the circumference of the coil layer 2111, and the width of the insulating layer 22 is equal to the width of the coil layer 2111. In this way, it can be ensured that each position between two adjacent coil layers 2111 is supported and isolated by the insulating layer 22, thereby improving the isolation effect of the insulating layer 22, and at the same time, it is convenient for the slurry of the insulating layer 22 to coat the coil layer 2111 as a whole, which is convenient for processing.

[0060] Of course, in other embodiments, the insulating layer 22 may only cover a portion of the coil layer 2111, and other portions of the tissue paper not covered by the insulating layer 22 of two adjacent coil layers 2111 are spaced apart, which is not limited here.

[0061] In some embodiments, the insulating layer 22 is formed on the first surface, so that after the coil portion 211 is wound around the magnetic column 12 and multiple coil layers 2111 are formed, the insulating layer 22 can be isolated between two adjacent coil layers 2111. The insulating layer 22 is only provided on the first surface to save materials and save costs. Of course, in other embodiments, the insulating layer 22 can also be formed on the second surface, or formed on the first surface and the second surface, or wrap the coil portion 211 as a whole, which is not limited here.

[0062] In some embodiments, see Figure 3 , the extension length of the insulating layer 22 is equal to the extension length of the coil body 21. It can be understood that the insulating layer 22 is also formed on the electrode portion 212, so that the insulating layer 22 is formed on the entire coil body 21, so that the inductor coil 20 can be processed as a whole. At this time, the second surface of the electrode portion 212 can be used to connect to an external circuit.

[0063] In some embodiments, see Figure 2 The two electrode portions 212 extend to one side of the second core surface 102, and the two electrode portions 212 are arranged at intervals, so that the two electrodes of the inductor are located on the same side, so that the inductor can be connected to the circuit. The electrode portion 212 can be wound around the core base 11 to improve the structural stability.

[0064] In some embodiments, see Figure 2 and Figure 3 The core base 11 also has a first side surface 103 and a second side surface 104 facing each other, and the first side surface 103 and the second side surface 104 are both connected to the first core surface 101 and the second core surface 102, that is, the first core surface 101, the first side surface 103, the second core surface 102 and the second side surface 104 are connected end to end in sequence. Among them, the first side surface 103 can be parallel to the second side surface 104, and the core base 11 is a cube at this time. The electrode portion 212 includes a connecting section 2121, a first bending section 2122, a second bending section 2123 and a third bending section 2124 which are connected in sequence. The connecting section 2121 is connected to the connecting end of the coil body 21. The connecting section 2121 is located on one side of the first core surface 101. The first bending section 2122 is located on one side of the first side surface 103 and is in contact with the first side surface 103. The second bending section 2123 is located on one side of the second core surface 102 and is in contact with the second core surface 102. The third bending section 2124 is located on one side of the second side surface 104 and is in contact with the second side surface 104.

[0065] In this way, the electrode portion 212 is wound around the core base 11, and the first bending section 2122 and the third bending section 2124 can limit the movement of the electrode portion 212 in the direction of the line from the first bending section 2122 to the third bending section 2124, and the coil portion 211 and the second bending section can limit the movement of the electrode portion 212 in the direction perpendicular to the second core surface 102, thereby improving the structural stability of the electrode portion 212 and the reliability of the inductor. Among them, the second bending section 2123 can be exposed outside the shielding cover 30, and the first bending section 2122 and the third bending section 2124 are both located inside the shielding cover 30, so as to improve the structural stability of the electrode portion 212 and prevent the electrode portion 212 from being separated from the core base 11.

[0066] In this embodiment, the connecting section 2121 is perpendicular to the first bending section 2122 , the first bending section 2122 is perpendicular to the second bending section 2123 , and the second bending section 2123 is perpendicular to the third bending section 2124 .

[0067] In some embodiments, see Figure 2 and Figure 3 The first side surface 103 is provided with a first protrusion 111, and the second side surface 104 is provided with a second protrusion 112. The first protrusion 111 is located between the first bending sections 2122 of the two electrode parts 212, and the second protrusion 112 is located between the third bending sections 2124 of the two electrode parts 212. The second bending sections 2123 of the two electrode parts 212 are parallel. The first protrusion 111 and the second protrusion 112 play a role in limiting and isolating the two electrode parts 212. The first protrusion 111 realizes the isolation of the first bending sections 2122 of the two electrode parts 212, and the second protrusion 112 realizes the isolation of the third bending sections 2124 of the two electrode parts 212, thereby ensuring that the second bending sections 2123 of the two electrode parts 212 are also isolated from each other.

[0068] The preparation method of the inductor is as follows:

[0069] S1. Take the flaky sendust powder 222 which has been passivated or coated with silicon dioxide, the D50 specification of the flaky sendust powder 222 is 3-5um, and mix 8-10% of polyvinyl butyral or polyethylene glycol by mass percentage of the sendust powder 222, 1-3% of dispersant by mass percentage of the sendust powder 222, 1-1.5% of dibutyl phthalate or butyl formate by mass percentage of the sendust powder 222, and 80-100% of acetone, toluene or anhydrous ethanol by mass percentage of the sendust powder 222 in a sand mill and stir for 3-6 hours, and then discharge the mixture to form a slurry for preparing the insulating layer 22;

[0070] S2, applying the slurry prepared in step S1 to the first surface of the coil body 21 by a coating method, controlling the coating thickness to be 10-30 um, and forming an insulating layer 22 after drying;

[0071] S3, winding the coil body 21 with the insulating layer 22 on the magnetic column 12 to shape;

[0072] S4, taking one, two or three of amorphous powder, alloy powder and carbonyl iron powder coated with silicon dioxide on the surface, adding 3-5% by weight of polyvinyl butyral or polyethylene glycol, 8-10% of acetone, or toluene, anhydrous ethanol, mixing and stirring, passing through a 40-150 mesh screen in a reciprocating granulator to make granules;

[0073] S5, using the pellets prepared in step S4 to press the magnetic core 10 at a pressure of 20-60 MPa;

[0074] S6, assembling the coil body 21 for the magnetic core 10 in step S5, wherein the insulating layer 22 faces the core base 11, and after the assembly, the electrode portion 212 is bent toward the second core surface 102 of the core base 11, and at this time, the insulating layer 22 is attached to the core base 11;

[0075] S7, placing the magnetic core 10 assembled with the coil body 21 into a mold and filling it with powder, so as to wrap the shielding cover 30 outside the magnetic core 10 assembled with the coil body 21 to form an inductor;

[0076] S8. Place the formed inductor into an atmosphere furnace, introduce nitrogen, and heat from room temperature to 750-900°C at a rate of 5°C / min, keep the temperature for 2 hours, cool naturally, and take out to complete the preparation of the inductor. If the heating temperature is too high, the powder particles will merge and the performance will deteriorate. If it is too low, dense grain boundaries cannot be formed.

[0077] The above descriptions are only some specific embodiments of the utility model, and only specifically describe the technical principles of the utility model. These descriptions are only for explaining the principles of the utility model and cannot be interpreted as limiting the protection scope of the utility model in any way. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model, and other specific implementation methods of the utility model that can be associated with the technicians in this field without creative work, should be included in the protection scope of the utility model.

Claims

1. An inductor, characterized in that: include: A magnetic core, comprising a core seat and a magnetic column protruding from the core seat; An inductor coil comprises a coil body and an insulating layer, wherein the coil body comprises a coil portion wound outside the magnetic column along the axial direction of the magnetic column and an electrode portion connected to two extended ends of the coil portion, the coil portion comprises a plurality of coil layers sequentially connected along the axial direction of the magnetic column, each of the coil layers surrounds the magnetic column, and the insulating layer is disposed between two adjacent coil layers, and the insulating layer comprises an isolation film and sendust powder filled in the isolation film; The shielding cover is connected to the core seat and covers the coil body and the magnetic core. The two electrode parts extend to the outside of the shielding cover.

2. The inductor according to claim 1, wherein: The Sendust powder is in flake form.

3. The inductor according to claim 2, wherein: The D50 specification of the Sendust powder is 3-5um.

4. The inductor according to claim 1, wherein: The insulating layer is provided between the coil layer of the coil part closest to the core base and the core base.

5. The inductor according to claim 1, wherein: The circumference of the insulating layer is equal to the circumference of the coil layer, and the width of the insulating layer is equal to the width of the coil layer.

6. The inductor according to claim 1, wherein: The extension length of the insulating layer is equal to the extension length of the coil body.

7. The inductor according to any one of claims 4 to 6, characterized in that: The coil portion has a first surface and a second surface that are opposite to each other. The first surface faces the core seat, and the insulating layer is formed on the first surface.

8. The inductor according to claim 1, wherein: The core seat has a first core surface and a second core surface facing each other. The magnetic column is protruded from the first core surface, and the two electrode parts extend to one side of the second core surface.

9. The inductor according to claim 8, wherein: The core seat also has a first side surface and a second side surface opposite to each other, and the first side surface and the second side surface are both connected to the first core surface and the second core surface. The electrode part includes a connecting section, a first bending section, a second bending section and a third bending section connected in sequence, and the connecting section is connected to the connecting end of the coil body. The connecting section is located on one side of the first core surface, the first bending section is located on one side of the first side surface and is in contact with the first side surface, the second bending section is located on one side of the second core surface and is in contact with the second core surface, and the third bending section is located on one side of the second side surface and is in contact with the second side surface.

10. The inductor according to claim 9, wherein: The first side surface is provided with a first protrusion, the second side surface is provided with a second protrusion, the first protrusion is located between the first bending sections of the two electrode parts, the second protrusion is located between the third bending sections of the two electrode parts, and the second bending sections of the two electrode parts are parallel.

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