An integrally formed inductor and a method of manufacturing the same

Abstract

This invention provides a molded inductor and its manufacturing method. The method involves fabricating a magnetic core, which includes a blade and a magnetic post connected to the blade; winding a coil on the magnetic post; placing the coil-wound magnetic core into a molding mold; performing a first filling process in the molding mold using magnetic powder of a first particle size; performing a second filling process in the molding mold using magnetic powder of a second particle size, where the second particle size is larger than the first particle size; performing a hot-pressing process to form a semi-finished inductor; and fabricating electrodes to form the molded inductor. In the filling process, finer powder is filled first, followed by coarser powder, to prevent the coil from being exposed.

Description

Technical Field

[0001] This invention relates to the field of inductor technology, and in particular to a molded inductor and its manufacturing method. Background Technology

[0002] Inductance is a property of a closed circuit and a physical quantity. When current flows through a coil, a magnetic field is induced in the coil, and this induced magnetic field in turn generates an induced current that opposes the current flowing through the coil. It is a circuit parameter describing the induced electromotive force effect in one coil or another coil caused by a change in coil current. Inductance is a general term for self-inductance and mutual inductance. The device that provides inductance is called an inductor. Molded inductors consist of a housing and a winding body. The housing is formed by die-casting the winding body into a metal magnetic powder, and the SMD leads are the leads of the winding body directly formed on the surface of the housing.

[0003] Existing integral molding inductor manufacturing processes have design flaws. In the core forming and winding stages, the inductor itself is designed to be too large, leaving insufficient space for the powder filling step. Furthermore, the particle size of the magnetic powder is too large, causing the coil to be exposed, commonly known as exposed copper, which affects the inductor performance. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a molded inductor and its manufacturing method, aiming to solve technical problems such as exposed inductor coils and unreliable performance in the prior art.

[0005] A method for manufacturing a molded inductor includes the following steps:

[0006] Step A1: Fabricate the magnetic core, which includes a blade pendulum and a magnetic post connected to the blade pendulum;

[0007] Step A2: Wind a coil on the magnetic post;

[0008] Step A3: Place the magnetic core with the coil wound into the molding mold, and use magnetic powder of the first particle size for the first powder filling process in the molding mold.

[0009] Step A4: In the molding die, a second filling process is performed using magnetic powder of a second particle size, which is larger than the first particle size.

[0010] Step A5: Perform hot pressing molding to form a semi-finished inductor;

[0011] Step A6: Fabricate electrodes to form a one-piece molded inductor.

[0012] Furthermore, the leaf pendulum is cross-shaped.

[0013] Furthermore, the cross-sectional area of ​​the magnetic column gradually decreases from the connection point with the blade pendulum to the top of the magnetic column.

[0014] Furthermore, the magnetic column is conical.

[0015] Furthermore, the first particle size is less than 100 micrometers.

[0016] A molded inductor, characterized in that it is manufactured by the aforementioned method for manufacturing a molded inductor, comprising:

[0017] The magnetic core includes a blade and a magnetic column connected to the blade.

[0018] A coil is wound on the magnetic column;

[0019] The lower part of the magnetic column near the blade is filled with magnetic powder of the first particle size, and the upper part of the magnetic column is filled with magnetic powder of the second particle size.

[0020] The second particle size is larger than the first particle size.

[0021] Furthermore, the leaf pendulum is cross-shaped.

[0022] Furthermore, the cross-sectional area of ​​the magnetic column gradually decreases from the connection point with the blade pendulum to the top of the magnetic column.

[0023] Furthermore, the magnetic column is conical.

[0024] Furthermore, the first particle size is less than 100 micrometers.

[0025] The beneficial technical effect of the present invention is that, in the powder filling step, fine powder is filled first, followed by coarse powder, thus avoiding the phenomenon of coil exposure. Attached Figure Description

[0026] Figure 1 This is a structural diagram of a preferred embodiment of a molded inductor according to the present invention;

[0027] Figure 2 This is a flowchart illustrating the steps of a method for manufacturing an integrally molded inductor according to the present invention.

[0028] in,

[0029] 1-Leaf pendulum;

[0030] 2-Magnetic column. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0034] See Figure 2 This invention provides a method for manufacturing a one-piece molded inductor, comprising the following steps:

[0035] Step A1: Fabricate the magnetic core, which includes a blade pendulum and a magnetic post connected to the blade pendulum;

[0036] Step A2: Wind a coil on the magnetic post;

[0037] Step A3: Place the magnetic core with the coil wound into the molding mold, and use magnetic powder of the first particle size for the first powder filling process in the molding mold.

[0038] Step A4: In the molding die, a second filling process is performed using magnetic powder of a second particle size, which is larger than the first particle size.

[0039] Step A5: Perform hot pressing molding to form a semi-finished inductor;

[0040] Step A6: Fabricate electrodes to form a one-piece molded inductor.

[0041] Furthermore, the leaf pendulum is cross-shaped.

[0042] Furthermore, the cross-sectional area of ​​the magnetic column gradually decreases from the connection point with the blade pendulum to the top of the magnetic column.

[0043] Furthermore, the magnetic column is conical.

[0044] Furthermore, the first particle size is less than 100 micrometers.

[0045] Coil exposure is a cosmetic defect in the production process, which means that the magnetic powder does not completely cover the coil. The main reasons for coil exposure are: (1) design problem: the volume of the magnetic forming and winding section is too large, and not enough space is reserved for filling powder; (2) the particle size of the magnetic powder is too large, so the magnetic powder cannot enter the space around the winding T-core, which naturally leads to coil exposure.

[0046] This invention features a magnetic post with a cross-sectional area that is thinner at the top and thicker at the bottom, creating a large opening that facilitates the entry of magnetic powder into the sidewall gaps. The powder is filled in two stages: first, fine powder is filled, then coarse powder is filled, as fine powder is easier to enter the sidewall gaps, and the larger space at the top is then filled with coarse powder. All of these steps ensure that the magnetic powder completely encapsulates the coil, solving the problem of exposed coils in the product.

[0047] The magnetic powder of this invention is composed of metal particles and resin adhesive. Specifically, a layer of resin adhesive is coated on the surface of the metal particles. If the magnetic powder particle size is small, the specific surface area is large, meaning there is more resin adhesive than metal particles. Conversely, if the magnetic powder particle size is large, the specific surface area is small, meaning there is more metal particles and less resin adhesive. In terms of characteristics, larger particle size magnetic powder has higher permeability, while smaller particle size magnetic powder has lower permeability. By coating the coil with magnetic powder, the magnetic powder can increase its inductance value. The higher the permeability of the magnetic powder, the greater the increase in the inductance value of the product. Therefore, this invention not only solves the problem of coil exposure, but also ensures the performance of the magnetic powder by using a combination of fine and coarse powder, thus guaranteeing the performance of the integrally molded inductor.

[0048] In this invention, the cross-shaped blade is directional, so the winding equipment is also directional, improving production efficiency. The magnetic column has a structure that is thinner at the top and thicker at the bottom, which increases the connection area between the magnetic column and the blade, making the connection more secure, reducing the likelihood of winding breakage, and increasing production yield.

[0049] See Figure 1 This invention provides a molded inductor, characterized in that it is manufactured by the aforementioned method for manufacturing a molded inductor, comprising:

[0050] The magnetic core includes a blade pendulum (1) and a magnetic column (2) connected to the blade pendulum;

[0051] A coil is wound on the magnetic column (2);

[0052] The lower part of the magnetic column (2) near the blade (1) is filled with magnetic powder of the first particle size, and the upper part of the magnetic column (2) is filled with magnetic powder of the second particle size.

[0053] The second particle size is larger than the first particle size.

[0054] Furthermore, the leaf pendulum is cross-shaped.

[0055] Furthermore, the cross-sectional area of ​​the magnetic column gradually decreases from the connection point with the blade pendulum to the top of the magnetic column.

[0056] Furthermore, the magnetic column is conical.

[0057] Furthermore, the first particle size is less than 100 micrometers.

[0058] Product coil exposure is an appearance defect in the production process, which means that the magnetic powder does not completely cover the coil. The main reasons for coil exposure are: (1) design problem: the volume of the magnetic forming and winding section is too large, and not enough space is reserved for filling powder; (2) the particle size of the magnetic powder is too large, so the magnetic powder cannot enter the space around the winding T-core, which naturally leads to coil exposure.

[0059] This invention features a magnetic post with a cross-sectional area that is thinner at the top and thicker at the bottom, creating a large opening that facilitates the entry of magnetic powder into the sidewall gaps. The powder is filled in two stages: first, fine powder is filled, then coarse powder is filled, as fine powder is easier to enter the sidewall gaps, and the larger space at the top is then filled with coarse powder. All of these steps ensure that the magnetic powder completely encapsulates the coil, solving the problem of exposed coils in the product.

[0060] The magnetic powder of this invention is composed of metal particles and resin adhesive. Specifically, a layer of resin adhesive is coated on the surface of the metal particles. If the magnetic powder particle size is small, the specific surface area is large, meaning there is more resin adhesive than metal particles. Conversely, if the magnetic powder particle size is large, the specific surface area is small, meaning there is more metal particles and less resin adhesive. In terms of characteristics, larger particle size magnetic powder has higher permeability, while smaller particle size magnetic powder has lower permeability. By coating the coil with magnetic powder, the magnetic powder can increase its inductance value. The higher the permeability of the magnetic powder, the greater the increase in the inductance value of the product. Therefore, this invention not only solves the problem of coil exposure, but also ensures the performance of the magnetic powder by using a combination of fine and coarse powder, thus guaranteeing the performance of the integrally molded inductor.

[0061] In this invention, the cross-shaped blade is directional, so the winding equipment is also directional, improving production efficiency. The magnetic column has a structure that is thinner at the top and thicker at the bottom, which increases the connection area between the magnetic column and the blade, making the connection more secure, reducing the likelihood of winding breakage, and increasing production yield.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a one-piece molded inductor, characterized in that, Includes the following steps: Step A1: Fabricate a magnetic core, which includes a blade pendulum and a magnetic post connected to the blade pendulum; Step A2: Wind a coil on the magnetic post; Step A3: Place the magnetic core with the coil wound on it into the molding mold, and perform the first powder filling process in the molding mold using magnetic powder of the first particle size. Step A4: In the molding die, a second powder filling process is performed using magnetic powder of a second particle size, where the second particle size is larger than the first particle size. Step A5: Perform hot pressing molding to form a semi-finished inductor; Step A6: Fabricate electrodes to form a one-piece molded inductor; The lower part of the magnetic column near the blade is filled with magnetic powder of a first particle size, and the upper part of the magnetic column is filled with magnetic powder of a second particle size. The magnetic powder is composed of metal particles and resin adhesive, and the surface of the metal particles is coated with a layer of resin adhesive. The blade pendulum is cross-shaped, and the cross-shaped blade pendulum includes a first part and a second part that have intersecting areas; The cross-sectional area of ​​the magnetic column gradually decreases from the connection portion connected to the blade pendulum to the top of the magnetic column; The connecting portion is entirely disposed on the first part and does not contact the second part excluding the intersection area.

2. The method for manufacturing an integrally molded inductor as described in claim 1, characterized in that, The first particle size is less than 100 micrometers.

3. A molded inductor, characterized in that, The inductor is manufactured by a method for manufacturing an integrally molded inductor as described in claim 1 or 2, comprising: The magnetic core includes a blade and a magnetic column connected to the blade; A coil is wound on the magnetic column; The lower part of the magnetic column near the blade is filled with magnetic powder of a first particle size, and the upper part of the magnetic column is filled with magnetic powder of a second particle size. The second particle size is larger than the first particle size; The magnetic powder is composed of metal particles and resin adhesive, with the surface of the metal particles coated with a layer of resin adhesive.

4. The integrally molded inductor as described in claim 3, characterized in that, The blade pendulum is cross-shaped.

5. The integrally molded inductor as described in claim 3, characterized in that, The cross-sectional area of ​​the magnetic column gradually decreases from the connection portion connected to the blade pendulum to the top of the magnetic column.

6. The integrally molded inductor as described in claim 3, characterized in that, The magnetic column is conical.

7. The integrally molded inductor as described in claim 3, characterized in that, The first particle size is less than 100 micrometers.

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