KR102569683B1 - Magnetic core, inductor and emi filter comprising the same - Google Patents

Abstract

An inductor according to an embodiment of the present invention includes a magnetic core, a bobbin accommodating the magnetic core, and a coil wound on the bobbin, wherein the magnetic core includes a first magnetic body and a second magnetic body of different kinds, , The first magnetic body and the second magnetic body are separated and disposed by a barrier rib disposed in the bobbin.

Description

Magnetic core, inductor and EMI filter including the same {MAGNETIC CORE, INDUCTOR AND EMI FILTER COMPRISING THE SAME}

The present invention relates to a magnetic core, an inductor, and an EMI filter including the same.

An inductor is one of electronic components applied on a printed circuit board, and may be applied to a resonant circuit, a filter circuit, a power circuit, etc. due to its electromagnetic characteristics.

Recently, since miniaturization and thinning of various electronic devices such as communication devices and display devices have become important issues, miniaturization, thinning, and high efficiency of inductors applied to these electronic devices are required.

Meanwhile, an EMI (ElectroMagnetic Interference) filter applied to the power board serves to pass signals necessary for circuit operation and remove noise. 1 shows a power board to which an EMI filter is applied, and FIG. 2 is an example of a circuit diagram of the EMI filter. Referring to FIGS. 1 and 2 , the EMI filter 10 may include a plurality of capacitors Cx and Cy and an inductor L. Types of noise generated from the power board can be largely divided into radiated noise of 30Mhz to 1Ghz radiated from the power board and conductive noise of 150Khz to 30Mhz conducted through a power line. A transmission method of conductive noise may be divided into a differential mode and a common mode. Among them, even a small amount of common mode noise returns in a large loop, so it can affect electronic devices that are far away. Such common mode noise is sometimes caused by impedance unbalance in a wiring system, and becomes more prominent in a high-frequency environment.

In order to remove common mode noise, an inductor applied to an EMI filter generally uses a toroidal-shaped magnetic core including an Mn-Zn-based ferrite material. Since Mn-Zn-based ferrite has a high permeability at 100 Khz to 1 Mhz, it is effective in removing common mode noise. As the power of the power board to which the EMI filter is applied increases, a magnetic core having a high inductance is required. Mn-Zn-based ferrite having such a high magnetic permeability has a high unit price, and since the core loss rate is low due to the material characteristics of the Mn-Zn-based ferrite, noise removal efficiency in the 6 to 30 MHz band is still low.

A technical problem to be achieved by the present invention is to provide a coil component applicable to an EMI filter.

An inductor according to an embodiment of the present invention includes a magnetic core, a bobbin accommodating the magnetic core, and a coil wound on the bobbin, wherein the magnetic core includes a first magnetic body and a second magnetic body of different kinds, , The first magnetic body and the second magnetic body are separated and disposed by a barrier rib disposed in the bobbin.

The first magnetic body may include ferrite, and the second magnetic body may include a metal ribbon.

The first magnetic body may have a toroidal shape, and the second magnetic body may be disposed on at least one of an inner circumferential surface and an outer circumferential surface of the first magnetic body.

The bobbin has a toroidal shape, and includes a bottom portion, an outer wall extending from the bottom portion and including an outer circumferential surface, an inner wall extending from the bottom portion and including an inner circumferential surface, and extending from the bottom portion, and comprising the first magnetic body and the first magnetic body. The barrier rib disposed between the two magnetic materials may be included.

Heights of bottom surfaces between the inner wall and the partition wall may be different from heights of bottom surfaces between the partition wall and the outer wall.

The coil may include a first coil wound on the bobbin and a second coil symmetrically wound around the first coil.

The second magnetic material may be disposed in a region where the first coil and the second coil are wound.

The second magnetic body includes an inner second magnetic body disposed on an inner circumferential surface of the first magnetic body and an outer second magnetic body disposed on an outer circumferential surface of the first magnetic body, and the barrier rib is formed between the inner second magnetic body and the first magnetic body. A first barrier rib disposed therebetween and a second barrier rib disposed between the first magnetic body and the external second magnetic body may be included.

The height of the bottom surface between the inner wall of the bobbin and the first partition wall or the height of the bottom surface between the outer wall of the bobbin and the second partition wall may be different from the height of the bottom surface between the first partition wall and the second partition wall.

A height of a bottom surface between the inner wall of the bobbin and the first partition wall or a height of a bottom surface between the outer wall of the bobbin and the second partition wall may be lower than a height of a bottom surface between the first partition wall and the second partition wall.

An EMI filter according to an embodiment of the present invention includes at least one inductor and at least one capacitor, wherein the inductor includes a magnetic core, a bobbin accommodating the magnetic core, and a coil wound on the bobbin, The magnetic core includes the first magnetic body and the second magnetic body of different kinds, and the first magnetic body and the second magnetic body are separated from each other by a barrier rib disposed in the bobbin.

According to an embodiment of the present invention, it is possible to obtain an EMI filter having excellent noise removal performance in a wide frequency band, being compact, and having a large power capacity. In particular, the EMI filter according to the embodiment of the present invention has high removal performance for common mode noise and differential mode noise among conductive noise. In addition, according to an embodiment of the present invention, it is possible to obtain an EMI filter capable of adjusting noise removal performance for each frequency band. In addition, according to an embodiment of the present invention, a separate bonding process for assembling heterogeneous magnetic materials is not required.

1 shows a power board to which an EMI filter is applied.
2 is an example of a circuit diagram of an EMI filter.
3 is a perspective view of an inductor according to an embodiment of the present invention.
4 is a perspective view and a cross-sectional view of a magnetic core according to an embodiment of the present invention.
5 and 6 are perspective and cross-sectional views of a magnetic core according to another embodiment of the present invention.
7 is a graph illustrating the skin effect theory.
8 is a graph showing magnetic flux versus skin depth of a ferrite material.
9 is a graph showing magnetic flux versus skin depth of a ferrite material and a metal ribbon material.
10 is a graph showing magnetic permeability and inductance of a ferrite material and a metal ribbon material.
11 shows a top view and a cross-sectional view of a magnetic core manufactured according to Comparative Examples and Examples.
12 is a graph showing noise removal performance of Comparative Examples and Examples.
13 shows differential mode noise improvement effects according to Comparative Examples and Examples.
14 shows a common mode noise improvement effect according to a comparative example and an embodiment.
15 shows a perspective view and a cross-sectional view of a bobbin according to an embodiment of the present invention.
FIG. 16 shows a perspective view and a cross-sectional view of a magnetic core accommodated in the bobbin of FIG. 15 .
17 shows a perspective view and a cross-sectional view of a magnetic core accommodated in a bobbin according to another embodiment of the present invention.
18 is a cross-sectional view of a bobbin according to another embodiment of the present invention.
19 is a cross-sectional view of a bobbin according to another embodiment of the present invention.
20 shows a perspective view and a cross-sectional view of a bobbin according to another embodiment of the present invention.
21 and 22 show cross-sectional views of the magnetic core accommodated in the bobbin of FIG. 20 .

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as second and first may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a second element may be termed a first element, and similarly, a first element may be termed a second element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

In the description of the embodiments, each layer (film), region, pattern or structure is "on" or "under" the substrate, each layer (film), region, pad or pattern. The substrate formed on includes all those formed directly or through another layer. The criteria for upper/upper or lower/lower of each layer will be described based on drawings. In addition, since the thickness or size of each layer (film), region, pattern, or structure in the drawing may be modified for clarity and convenience of description, it does not entirely reflect the actual size.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, but the same or corresponding components regardless of reference numerals are given the same reference numerals, and overlapping descriptions thereof will be omitted.

3 is a perspective view of an inductor according to an embodiment of the present invention.

Referring to FIG. 3 , the inductor 100 includes a magnetic core 110 , a bobbin 120 accommodating the magnetic core 110 , and a coil 130 wound on the bobbin 120 . At this time, the magnetic core 110 and the bobbin 120 may have a toroidal shape, and the coil 130 may be wound on the bobbin 120 by the first coil 132 and the first coil 132. A second coil 134 wound symmetrically may be included. The first coil 132 and the second coil 134 may be wound on the upper surface S1, the outer circumferential surface S2, the lower surface S3, and the inner circumferential surface S4 of the toroidal bobbin 120, respectively. The coil 130 may be formed of a conducting wire whose surface is coated with an insulating material. The conducting wire may be made of copper, silver, aluminum, gold, nickel, tin, etc. whose surface is coated with an insulating material, and the cross section of the conducting wire may have a circular or prismatic shape.

The bobbin 120 is disposed to insulate the magnetic core 110 and the coil 130, and may include plastic or metal having an insulated surface. The bobbin 120 is, for example, PBT (Poly Butylene Terephthalate) resin, PET (Poly Ethylene Terephthalate) resin, PA6 (Polyamide 6) resin, PA66 (Polyamide 66) resin, POM (PolyOxyMethylene) resin, PC (PolyCarbonate) resin, MPPO (Modified PolyPhenylene Oxide) resin or the like may be included, or a ceramic material may be included.

According to an embodiment of the present invention, the magnetic core 110 includes a heterogeneous magnetic material.

4 is a perspective view and cross-sectional view of a magnetic core according to one embodiment of the present invention, and FIGS. 5 and 6 are perspective and cross-sectional views of a magnetic core according to another embodiment of the present invention.

4, the magnetic core 110 includes a first magnetic body 112 and a second magnetic body 114, the first magnetic body 112 and the second magnetic body 114 are heterogeneous, and the second magnetic body ( 114) may be disposed on at least a portion of the surface of the first magnetic body 112. At this time, the second magnetic body 114 may have a higher saturation magnetic flux density than the first magnetic body 112 .

Here, the first magnetic body 112 may include ferrite, and the second magnetic body 114 may include a metal ribbon. Here, the magnetic permeability (μ) of ferrite may be 2,000 to 15,000, and the magnetic permeability (μ) of the metal ribbon may be 100,000 to 150,000. For example, the ferrite may be Mn—Zn-based ferrite, and the metal ribbon may be Fe-based nanocrystalline metal ribbon. The Fe-based nanocrystalline metal ribbon may be a nanocrystalline metal ribbon containing Fe and Si.

At this time, the first magnetic body 112 and the second magnetic body 114 each have a toroidal shape, and the second magnetic body 114 is disposed on the outer circumferential surface S2 of the first magnetic body 112. 1) and an internal second magnetic body 114-2 disposed on the inner circumferential surface S4 of the first magnetic body 112.

At this time, the thickness of the second magnetic body 114 is thinner than the thickness of the first magnetic body 112 . By adjusting the ratio between the thickness of the second magnetic body 114 and the thickness of the first magnetic body 112, the permeability of the magnetic core 110 can be adjusted.

To this end, the second magnetic material 114 may include a metal ribbon wound in multiple layers.

Although the outer second magnetic body 114-1 and the inner second magnetic body 114-2 are illustrated as having the same material and thickness, it is not limited thereto. The outer second magnetic body 114-1 and the inner second magnetic body 114-2 may have different materials or magnetic permeability, and may have different thicknesses. Accordingly, the permeability of the magnetic core 110 may have various ranges.

Alternatively, as shown in FIG. 5, the second magnetic body 114 is disposed only on the outer circumference S2 of the first magnetic body 112, or as shown in FIG. 6, the second magnetic body 114 is disposed on the inner circumferential surface of the first magnetic body 112 ( It may be arranged only in S4).

In this way, if the magnetic core 110 includes heterogeneous magnetic materials having different permeability, it is possible to remove noise in a wide frequency band. In particular, compared to toroidal-type magnetic cores made of only Mn-Zn-based ferrite, magnetic flux is prevented from being concentrated on the surface, so the effect of removing high-frequency noise is high, and internal saturation is lowered, so it can be applied to high-power products. In addition, the performance of the magnetic core 110 can be adjusted by adjusting the magnetic permeability and volume ratio of the first magnetic body 112 and the second magnetic body 114 .

Hereinafter, the effect of the embodiment in which the magnetic core 110 includes a heterogeneous magnetic material will be described in more detail.

7 is a graph showing skin effect theory, FIG. 8 is a graph showing magnetic flux with respect to skin depth of a ferrite material, and FIG. 9 is a graph showing magnetic flux with respect to skin depth of a ferrite material and a metal ribbon material. 10 is a graph showing magnetic permeability and inductance of a ferrite material and a metal ribbon material.

Referring to FIG. 7 and Equation 1 below, the higher the specific permeability of the material and the higher the frequency, the smaller the skin depth value. Accordingly, a phenomenon in which the magnetic flux gathers on the surface of the material appears.

where δ is the skin depth, ρ is the resistivity, μ _s is the relative permeability, and f is the frequency.

Referring to FIG. 8 , the thinner the skin depth δ, the higher the magnetic flux Bm. Since the saturation magnetic flux density of the ferrite material is 0.47T, when the magnetic core is a ferrite core, the magnetic core becomes saturated when the magnetic flux exceeds 0.47T, and thus noise removal performance may deteriorate.

Referring to FIG. 9, when a material having a saturation magnetic flux density greater than the saturation magnetic flux density of the ferrite material, for example, a metal ribbon material is disposed on the surface of the ferrite material, it can withstand high magnetic flux at a thin skin depth, improving noise performance. can be maintained

In this way, if the second magnetic material having a higher saturation magnetic flux density than the first magnetic material is disposed on at least a portion of the surface of the first magnetic material, the effective sectional area of the magnetic core can be increased at a high frequency.

Meanwhile, referring to FIG. 10 , it can be seen that a magnetic core including both a ferrite material and a metal ribbon material having different magnetic permeability for each frequency has high inductance in a predetermined frequency range, and thus high noise removal performance can be obtained.

Hereinafter, further explanation is made using comparative examples and examples.

11 is a top view and cross-sectional view of a magnetic core manufactured according to Comparative Examples and Examples, FIG. 12 is a graph showing noise removal performance of Comparative Examples and Examples, and FIG. 13 is a differential mode according to Comparative Examples and Examples A noise improvement effect is shown, and FIG. 14 shows a common mode noise improvement effect according to a comparative example and an embodiment.

Referring to FIG. 11, in Comparative Example and Examples 1 to 3, the first magnetic material has an inner diameter (ID), an outer diameter (OD), and a height (T) of 15 mm, 25 mm, and 15 mm, respectively, and has a toroidal Mn-Zn A ferrite core was used. And, in Examples 1 to 3, Fe—Si-based metal ribbon was used as the second magnetic material, and it was laminated to have a thickness of 2 mm.

In Comparative Example, the second magnetic body was not disposed. In Example 1, the second magnetic body was disposed on the outer circumferential surface of the first magnetic body, and in Example 2, the second magnetic body was disposed on the inner circumferential surface of the first magnetic body. In Example 3, the second magnetic body was disposed on the outer and inner circumferential surfaces of the first magnetic body.

A coil was wound with 21 turns on the magnetic core according to Comparative Example and Examples 1 to 3, and noise removal performance was simulated under the conditions of an applied current of 1A and a power of 220W.

As a result, referring to FIG. 12 , it can be seen that the larger the area where the second magnetic material is disposed, the higher the noise removal performance.

In FIGS. 13 and 14 , differential mode noise rejection performance and common mode noise rejection performance were verified by measuring a magnetic field after connecting the magnetic core according to Comparative Example and Example 3 to the power board.

Referring to FIG. 13 , it can be seen that the degree of saturation inside the magnetic core is lowered in the magnetic core according to Example 3 compared to the magnetic core according to the comparative example. Accordingly, it can be seen that the magnetic core according to the embodiment of the present invention is suitable for high-power products.

Referring to FIG. 14, in the magnetic core according to Comparative Example, as the frequency increases, the surface of the magnetic core is saturated and the area efficiency decreases. However, the magnetic core according to Example 3 has a second magnetic body disposed on the surface of the first magnetic body. Therefore, it can be seen that the surface of the magnetic core is not saturated, the area efficiency is improved, and the noise removal effect at high frequency is great.

However, the second magnetic material 114, which is a metal ribbon, is thin and requires winding several times. In addition, an bonding process is required to arrange the wound metal ribbon on the inner or outer circumferential surface of the first magnetic material 112, and this bonding process is not easy to work with.

Accordingly, in the embodiment of the present invention, the first magnetic body and the second magnetic body are intended to be accommodated by the barrier rib disposed in the bobbin.

15 is a perspective view and a cross-sectional view of a bobbin according to an embodiment of the present invention, FIG. 16 is a perspective view and a cross-sectional view of a magnetic core accommodated in the bobbin of FIG. 15, and FIG. 17 is a bobbin according to another embodiment of the present invention. Perspective and cross-sectional views of the accommodated magnetic core are shown.

Referring to FIGS. 15 and 16 , the bobbin 1500 includes a lower case 1510 and an upper cover 1520 for accommodating the first magnetic body 112 and the second magnetic body 114 . The lower case 1510 includes a bottom portion 1512, an outer wall 1514 extending from the bottom portion 1512 and including an outer circumferential surface, an inner wall 1516 extending from the bottom portion 1512 and including an inner circumferential surface, and a bottom portion ( and a partition wall 1518 extending from 1512 and disposed between outer wall 1514 and inner wall 1516 .

The first magnetic body 112 and the second magnetic body 114 may be separated from each other by the barrier rib 1518 and disposed.

When the second magnetic body 114 is disposed on the inner and outer circumferential surfaces of the first magnetic body 112, the external second magnetic body 114-1 and the first magnetic body 112 are separated by the first barrier rib 1518-1. The first magnetic body 112 and the internal second magnetic body 114-2 may be separated by the second barrier rib 1518-2.

To this end, the pre-formed first magnetic body 112 is accommodated in the space between the first barrier rib 1518-1 and the second barrier rib 1518-2, and the pre-wound second magnetic body 114-1, 114- 2) may be accommodated in a space between the outer wall 1512 and the first partition wall 1518-1 and a space between the second partition wall 1518-2 and the inner wall 1516, respectively.

Accordingly, a process of bonding the first magnetic material 112 and the second magnetic material 114-1, 114-2 and a process of winding the second magnetic material 114-1 around the outer circumferential surface of the first magnetic material 112. Since this is not required, the fabrication process is simple.

At this time, the distance between the first partition wall 1518-1 and the second partition wall 1518-1 for accommodating the first magnetic material 112 and the outer wall 1514 for accommodating the second magnetic material 114 and the first partition wall ( 1518-1 or the distance between the second partition wall 1518-2 and the inner wall 1516. Accordingly, the second magnetic body 114 may be accommodated thinner than the first magnetic body 112, and the second magnetic body 114 may surround the outer circumferential surface of the first magnetic body 112 with a larger area.

Meanwhile, referring to FIG. 17 , the second magnetic bodies 114-1 and 114-2 may be disposed only in regions where coils are wound. To this end, the first barrier rib 1518-1 and the second barrier rib 1518-2 may be disposed only in the region where the coil is wound.

18 is a cross-sectional view of a bobbin according to another embodiment of the present invention, and FIG. 19 is a cross-sectional view of a bobbin according to another embodiment of the present invention.

Referring to FIG. 18 , as shown in (a), the heights of the first partition wall 1518-1 and the second partition wall 1518-2 may be lower than the heights of the outer wall 1514 and the inner wall 1516. Accordingly, the first magnetic body 112 and the second magnetic bodies 114-1 and 114-2 can directly contact each other in some areas, and the second magnetic body 114 has a higher saturation magnetic flux density than the first magnetic body 112. -1, 114-2), it is possible to increase the effective sectional area of the magnetic core at high frequencies.

In addition, as in (b) and (c), the height of the bottom portion 1512 between the outer wall 1514 of the bobbin 1510 and the first partition 1518-1 or the inner wall 1516 of the bobbin 1510 and the second The height of the bottom portion 1512 between the two partition walls 1518-2 may be different from the height of the bottom portion 1512 between the first partition wall 1518-1 and the second partition wall 1518-2. For example, as shown in (b), the height of the bottom portion 1512 between the outer wall 1514 of the bobbin 1510 and the first partition wall 1518-1 or the inner wall 1516 of the bobbin 1510 and the second partition wall The height of the bottom portion 1512 between 1518-2 is lower than the height of the bottom portion 1512 between the first partition wall 1518-1 and the second partition wall 1518-2, or, as shown in (c), the bobbin 1510 ) The height of the bottom portion 1512 between the outer wall 1514 and the first partition wall 1518-1 or the height of the bottom portion 1512 between the inner wall 1516 of the bobbin 1510 and the second partition wall 1518-2 It may be higher than the height of the bottom part 1512 between the first partition wall 1518-1 and the second partition wall 1518-2.

According to this, it is possible to easily arrange the first magnetic body 112 and the second magnetic body 114 in various combinations.

Referring to FIG. 19 , not only the lower case 1510 of the bobbin 1500, but also the upper cover 1520 may have the same structure as the lower case 1510. That is, the top cover 1520 includes a bottom portion 1522, an outer wall 1524 extending from the bottom portion 1522 and including an outer circumferential surface, an inner wall 1526 extending from the bottom portion 1522 and including an inner circumferential surface, and a bottom. A first partition wall 1528 - 1 and a second partition wall 1528 - 2 extending from the portion 1522 and disposed between the outer wall 1524 and the inner wall 1526 may be included.

20 shows a perspective view and a cross-sectional view of a bobbin according to another embodiment of the present invention, and FIGS. 21 and 22 show a perspective view and a cross-sectional view of a magnetic core accommodated in the bobbin of FIG. 20 .

20 to 22 , the bobbin 2000 includes a lower case 2010 and an upper cover 2020 for accommodating the first magnetic body 112 and the second magnetic body 114 . The lower case 2010 includes a bottom portion 2012, an outer wall 2014 extending from the bottom portion 2012 and including an outer circumferential surface, an inner wall 2016 extending from the bottom portion 2012 and including an inner circumferential surface, and a bottom portion ( 2012, and includes a partition wall 2018 disposed between the outer wall 2014 and the inner wall 2016.

The first magnetic body 112 and the second magnetic body 114 may be separated and disposed by the barrier rib 2018 .

As shown in FIG. 21 , the second magnetic body 114 may be disposed on the outer circumferential surface of the first magnetic body 112 , or as shown in FIG. 22 , the second magnetic body 114 may be disposed on the inner circumferential surface of the first magnetic body 112 . At this time, the first magnetic body 112 and the second magnetic body 114 may be separated by the barrier rib 2018 .

Here, the distance between the outer wall 2014 and the partition wall 2018 and the distance between the partition wall 2018 and the inner wall 2016 may be different. For example, when the second magnetic body 114 is disposed on the outer circumferential surface of the first magnetic body 112 as shown in FIG. can be short Accordingly, the second magnetic body 114 can be accommodated thinner than the first magnetic body 112, and the area surrounding the outer circumferential surface of the first magnetic body 112 can be wider.

Meanwhile, the shape of the bobbin according to FIGS. 18 and 19 may also be applied to the embodiments of FIGS. 20 to 22 .

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100: inductor
1500, 2000: bobbin
1510: lower case
1520: upper cover

Claims (11)

magnetic core,
A bobbin accommodating the magnetic core, and
Including a coil wound on the bobbin,
The magnetic core includes a first magnetic body and a second magnetic body of different kinds,
The first magnetic body and the second magnetic body are separated and disposed by a partition wall disposed in the bobbin,
The bobbin has a toroidal shape, and includes a bottom portion, an outer wall extending from the bottom portion and including an outer circumferential surface, an inner wall extending from the bottom portion and including an inner circumferential surface, and extending from the bottom portion to include the first magnetic body and the second magnetic material. Including the barrier rib disposed between the magnetic materials,
The inductor according to claim 1 , wherein a height of a bottom surface between the inner wall and the barrier rib is different from a height of a bottom surface between the barrier rib and the outer wall. According to claim 1,
The inductor of claim 1 , wherein the first magnetic body includes ferrite, and the second magnetic body includes a metal ribbon. According to claim 2,
The first magnetic body has a toroidal shape,
The second magnetic body is disposed on at least one of an inner circumferential surface and an outer circumferential surface of the first magnetic body. delete delete According to claim 1,
The coil includes a first coil wound on the bobbin, and a second coil symmetrically wound around the first coil. According to claim 6,
The second magnetic material is disposed in a region in which the first coil and the second coil are wound. delete magnetic core,
A bobbin accommodating the magnetic core, and
Including a coil wound on the bobbin,
The magnetic core includes a first magnetic body and a second magnetic body of different kinds,
The second magnetic body includes an inner second magnetic body disposed on an inner circumferential surface of the first magnetic body and an outer second magnetic body disposed on an outer circumferential surface of the first magnetic body;
The bobbin has a toroidal shape, and includes a bottom portion, an outer wall extending from the bottom portion and including an outer circumferential surface, an inner wall extending from the bottom portion and including an inner circumferential surface, and extending from the bottom portion to include the inner second magnetic material and the first inner wall. A first barrier rib disposed between magnetic bodies, and a second barrier rib extending from the bottom portion and disposed between the first magnetic body and the external second magnetic body,
The height of the bottom surface between the inner wall of the bobbin and the first partition wall or the height of the bottom surface between the outer wall of the bobbin and the second partition wall is different from the height of the bottom surface between the first partition wall and the second partition wall. According to claim 9,
The height of the bottom surface between the inner wall of the bobbin and the first partition wall or the height of the bottom surface between the outer wall of the bobbin and the second partition wall is lower than a height of the bottom surface between the first partition wall and the second partition wall. An EMI filter comprising the inductor according to claim 1 or 9 and at least one capacitor.

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