KR20180071824A - Magnetic core and coil component - Google Patents

Abstract

A magnetic core according to an embodiment of the present invention includes a first magnetic core including pure iron or Fe-based alloy, and a second magnetic core surrounding the outer peripheral surface of at least a part of the first magnetic core, and including ferrite. The magnetic core can be used for large current.

Description

[0001] MAGNETIC CORE AND COIL COMPONENT [0002]

The present invention relates to a magnetic core and a coil component.

A high-current step-down inductor, a high-current step-up inductor, a three-phase line reactor, etc. for a PFC (Power Factor Correction) used in a photovoltaic system, a wind power generation system or an electric vehicle include a coil wound on a magnetic core. The magnetic core included in the large current inductor or the large current reactor needs to increase the direct current superposition characteristic in a large current, reduce the core loss at a high frequency, and obtain a stable permeability, so that the inductance needs to be increased. The inductance can be determined according to equation (1).

Here, A _L is the inductance of the 1Ts, N is the number of windings (Winding Turns), μ is the magnetic permeability (permeability), and, A is a sectional area of the core, l _e is the character length (Magnetic path length), L is the inductance (Inductance).

According to Equation (1), the inductance can be adjusted by using the magnetic permeability, the number of turns, and the cross-sectional area of the core.

On the other hand, a metal core obtained by molding a pure iron powder or an iron-based alloy powder may be used in order to enhance the high direct current superimposition characteristic in a large current, but this has a problem of low permeability and core loss performance.

Accordingly, there is an attempt to use a ferrite core obtained by molding a ferrite having a low DC charging characteristic but excellent in magnetic permeability and core loss performance. However, in the hybrid type core including the metal core and the ferrite core together, a gap G may be generated at the junction between the metal core and the ferrite core. This gap weakens the reliability of the magnetic core, There is a problem in that the inductance is lowered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic core applicable to a large current and a coil component including the same.

A magnetic core according to an embodiment of the present invention includes a first magnetic core including a pure iron or an Fe-based alloy, and a second magnetic core disposed around the outer peripheral surface of at least a part of the first magnetic core, .

Wherein the first magnetic core includes a magnetic core, a first leg, a second leg, and a third leg integrally formed with the magnetic core, and the third leg is disposed between the first leg and the second leg Wherein the pair of partial magnetic cores includes a pair of partial magnetic cores, and the pair of partial magnetic cores are arranged to face each other, and the first and second partial magnetic cores included in the first partial magnetic core, which is one of the pair of partial magnetic cores, Each of the legs and the third leg may be joined to the first leg, the second leg, and the third leg included in the second partial magnetic core which is the remaining one of the pair of partial magnetic cores.

The second magnetic core includes a first leg included in each of the pair of partial magnetic cores, a second leg included in each of the pair of partial magnetic cores, and a third leg included in each of the pair of partial magnetic cores, At least one outer circumferential surface.

The second magnetic core includes two first legs each included in the pair of partial magnetic cores, two second legs each included in the pair of partial magnetic cores, and a pair of second magnetic cores The outer circumferential surface of at least one of the two third legs can be integrally enclosed.

The second magnetic core may have a hollow for surrounding the outer circumferential surface, and the inner circumferential surface of the hollow may contact the outer circumferential surface.

At least one of a groove and a protrusion may be formed on the inner circumferential surface of the hollow, and at least one of a protrusion and a groove may be formed on the outer circumference of the hollow, corresponding to the groove and the protrusion formed on the inner circumferential surface of the hollow.

At least one of the groove and the protrusion formed on the inner circumferential surface of the hollow and at least one of the protrusion and the groove formed on the outer circumferential surface may be formed in a direction extending from the top to the bottom.

At least one of the groove and the protrusion formed on the inner circumferential surface of the hollow and at least one of the protrusion and the groove formed on the outer circumferential surface may be formed in a threaded shape.

The second magnetic core may include Ni-Zn ferrite or Mn-Zn ferrite.

A coil component according to an embodiment of the present invention includes a magnetic core and a coil wound on the magnetic core, wherein the magnetic core includes a first magnetic core including a pure iron or Fe-based alloy, And a second magnetic core including ferrite, wherein the coil is wound on the second magnetic core.

According to the embodiment of the present invention, a magnetic core having a high direct current superimposition characteristic and a high magnetic permeability, a low core loss factor, and a coil component including the same can be obtained. It is also possible to adjust the magnetic permeability and core loss ratio according to the user's needs. Accordingly, the magnetic core and the coil component according to the embodiment of the present invention can be applied to vehicles and industries such as large current inductors and large current reactors.

1 is a perspective view of a magnetic core according to an embodiment of the present invention.
2 is a perspective view of a coil component including a magnetic core according to one embodiment of the present invention.
3 shows various shapes of the first magnetic core included in the magnetic core according to the embodiment of the present invention.
4 shows various shapes of the second magnetic core included in the magnetic core according to the embodiment of the present invention.
5 is an example of a process of assembling a magnetic core according to an embodiment of the present invention.
6 is another example of the assembly process of the magnetic core according to the embodiment of the present invention.
7 to 9 are examples of the contact surfaces of the first magnetic core and the second magnetic core according to an embodiment of the present invention.
10 is another example of the contact surfaces of the first magnetic core and the second magnetic core according to an embodiment of the present invention.
11 is a graph showing the magnetic permeability according to the volume ratio between the first magnetic core and the second magnetic core.
12 is a graph showing a core loss rate according to a volume ratio between the first magnetic core and the second magnetic core.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be 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, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

In describing embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" a substrate, a layer, Includes all that is formed directly or via another layer. The criteria for top / bottom or bottom / bottom of each layer are described with reference to the drawings. In addition, the thickness or size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

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 this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

FIG. 1 is a perspective view of a magnetic core according to one embodiment of the present invention, and FIG. 2 is a perspective view of a coil component including a magnetic core according to an embodiment of the present invention.

Referring to Figures 1-2, the coil component 10 includes a magnetic core 100 and a coil 200 that is wound on the magnetic core 100.

The magnetic core 100 includes a first magnetic core 110 and a second magnetic core 120 disposed to surround the outer circumferential surface of at least a part of the first magnetic core 110.

The first magnetic core 110 may include a pure iron or Fe-based magnetic powder. Examples of the Fe-based magnetic powder include Fe-Si-B type magnetic powder, Fe-Ni type magnetic powder, Fe-Si type magnetic powder, Fe-Si-Al type magnetic powder, Fe- But it is not limited to at least one selected from the group consisting of Fe-Si-B type magnetic powder, Fe-Si-C type magnetic powder and Fe-B-Si-Nb-Cu type magnetic powder. The first magnetic core 110 may be manufactured by coating pure iron or a Fe-based magnetic powder with a ceramic or polymer binder, insulating it, and molding at a high pressure. Alternatively, the first magnetic core 110 may be manufactured by laminating a plurality of magnetic sheet layers obtained by coating pure iron or Fe-based magnetic powder with a ceramic or polymer binder, followed by insulation.

The second magnetic core 120 may comprise a ferrite powder. The ferrite powder may be, for example, a Ni-Zn ferrite powder or a Mn-Zn ferrite powder. The second magnetic core 120 may be manufactured by a method in which ferrite powder is coated with a ceramic or polymer binder, followed by insulation and molding at a high pressure. Alternatively, the second magnetic core 120 may be manufactured by a method of laminating a plurality of magnetic sheet layers obtained by coating a ferrite powder with a ceramic or polymer binder, and then inserting the ferrite powder.

Here, the coil 200 may be wound on the second magnetic core 120, and an insulating layer, for example, a bobbin may be further disposed between the coil 200 and the second magnetic core 110. The coil 200 may be formed of a wire whose surface is coated with an insulating material. The lead may be copper, silver, aluminum, gold, nickel, tin or the like whose surface is coated with an insulating material, and the cross section of the lead may have a round or square shape.

Both ends of the coil 200 may be connected to an electrode (not shown).

According to the embodiment of the present invention, when the magnetic core 100 includes the first magnetic core 110 including the pure iron or the Fe-based alloy and the second magnetic core 120 including the ferrite powder, It is possible to obtain not only a high direct current superposition characteristic of the core 110 but also a high magnetic permeability and a high magnetic permeability of the second magnetic core 120 so that an inductor or a reactor applicable to a large current can be obtained.

Also, according to the embodiment of the present invention, the volume ratio of the first magnetic core 110 and the second magnetic core 120 can be adjusted to obtain a desired level of permeability and core loss ratio.

According to the embodiment of the present invention, since the second magnetic core 120 is disposed so as to surround the outer peripheral surface of the first magnetic core 110, the joint between the second magnetic core 120 and the first magnetic core 110 And the second magnetic core 120 is less likely to be separated from the first magnetic core 110, so that the durability is high.

Hereinafter, a magnetic core according to an embodiment of the present invention will be described in more detail with reference to the drawings.

FIG. 3 shows various shapes of the first magnetic core included in the magnetic core according to the embodiment of the present invention, FIG. 4 shows various shapes of the second magnetic core included in the magnetic core according to the embodiment of the present invention, 6 is an example of a process of assembling a magnetic core according to an embodiment of the present invention.

Referring to FIG. 3, the first magnetic core 110 includes a pair of partial magnetic cores 112, 114. Each of the partial magnetic cores 112 and 114 is made of the same material as the magnetic cores 112-1 and 114-1 and the magnetic cores 112-1 and 114-1 and is formed integrally with the magnetic cores 112-1 and 114-1 Includes first legs 112-2 and 114-2, second legs 112-3 and 114-3 and third legs 112-4 and 114-4, and first legs 112-2, The second legs 112-3 and 114-3 and the third legs 112-4 and 114-4 are arranged to be parallel to each other and the third legs 112-4 and 114-4 And is disposed between the first leg 112-2, 114-2 and the second leg 112-3, 114-3. The EER core and the EE core are illustrated in FIGS. 3 (a) and 3 (c), respectively, but the present invention is not limited thereto, and various shapes of cores such as an ER core, an EQ core, and a PQ core may be used.

In a magnetic core 100 according to an embodiment of the present invention, a pair of partial magnetic cores 112 and 114 are disposed to face each other, and a first partial magnetic core 112, which is one of a pair of partial magnetic cores, The first leg 112-2, the second leg 112-3, and the third leg 112-4 included in the second partial magnetic core 114 are included in the second partial magnetic core 114, which is the other one of the pair of partial magnetic cores The first leg 114-2, the second leg 114-3, and the third leg 114-4, which are included.

4, the second magnetic core 120 includes first and second legs 112-2 and 114-2 included in the first magnetic core 110, second legs 112-3 and 114-3, A hollow h may be formed in the second magnetic core 120 to surround the outer circumferential surface of at least one of the third legs 112-4 and 114-4. The shape of the hollow h is defined by at least one of the first legs 112-2 and 114-2, the second legs 112-3 and 114-3 and the third legs 112-4 and 114-4, And the like.

5, a first partial magnetic core 112 including a first leg 112-2, a second leg 112-3 and a third leg 112-4, a first leg 114- The second partial magnetic core 112 including the second leg 114-3 and the third leg 114-4 and the second magnetic core 120 formed with the hollow h are provided (a) coupling one end of the second magnetic core 120 to the third leg 112-4 of the first partial magnetic core 112 (b). Thus, one end of the second magnetic core 120 is disposed to surround the outer circumferential surface of the third leg 112-4 of the first partial magnetic core 112, and the inner circumferential surface of one end of the second magnetic core 120 And may contact the outer circumferential surface of the third leg 112-4. Next, the other end of the second magnetic core 120 and the third leg 114-4 of the second partial magnetic core 114 are engaged (c). The other end of the second magnetic core 120 is disposed so as to surround the outer circumferential surface of the third leg 114-4 of the second partial magnetic core 114 and the inner circumferential surface of the other end of the second magnetic core 120 And may be in contact with the outer peripheral surface of the third leg 114-4.

According to this, the second magnetic core 120 can integrally surround the outer circumferential surfaces of the two third legs included in the pair of partial magnetic cores 112 and 114, respectively.

6, a first partial magnetic core 112 including a first leg 112-2, a second leg 112-3 and a third leg 112-4, A second partial magnetic core 112 including one leg 114-2, a second leg 114-3 and a third leg 114-4, two second magnetic cores (A), the third leg 112-4 of the first partial magnetic core 112 and the one second magnetic core 120-1 are coupled to each other (b) . Accordingly, the second magnetic core 120-1 is disposed so as to surround the outer circumferential surface of the third leg 112-4 of the first partial magnetic core 112, and the inner circumferential surface of the second magnetic core 120-1 And may contact the outer circumferential surface of the third leg 112-4. Next, the other one second magnetic core 120-2 and the third leg 114-4 of the second partial magnetic core 114 are joined (c). Accordingly, the second magnetic core 120-2 is disposed so as to surround the outer circumferential surface of the third leg 114-4 of the second partial magnetic core 114, and the inner circumferential surface of the second magnetic core 120-2 And may be in contact with the outer peripheral surface of the third leg 114-4.

5 to 6, for convenience of explanation, it is assumed that the second magnetic core 120 surrounds the third legs 112-4 and 114-4 included in the pair of partial magnetic cores 112 and 114, But is not limited thereto. The second magnetic core 120 surrounds the first legs 112-2 and 114-2 included in the pair of partial magnetic cores 112 and 114 or the pair of partial magnetic cores 112 and 114, The second leg 112-3 and the second leg 114-3, respectively. Alternatively, the two second magnetic cores 120 may include first legs 112-2 and 114-2 and second legs 112-3 and 114-, respectively, included in the pair of partial magnetic cores 112 and 114, 3).

According to the embodiment of the present invention, at least one of the groove and the protrusion is formed on the hollow inner circumferential surface of the second magnetic core 120, and on the outer circumferential surface of the third legs 112-4 and 114-4, At least one of the recess and the protrusion corresponding to the protrusion and the groove may be formed.

FIGS. 7 to 9 are examples of contact surfaces of a first magnetic core and a second magnetic core according to an embodiment of the present invention, and FIG. 10 is a cross-sectional view of a first magnetic core and a second magnetic core according to an embodiment of the present invention. It is another example of a contact surface.

7, at least one protrusion P extending from the upper portion to the lower portion is formed on the inner circumferential surface of the second magnetic core 120, and the third legs 112-4, 114 The protrusions P of the second magnetic core 120 are formed on the outer circumferential surface of the third legs 112-4 and 114-4, (G).

8, at least one groove G extending in the downward direction from the top is formed on the inner circumferential surface of the second magnetic core 120, and the third leg 112-4 of the first magnetic core 110 And at least one protrusion P extending from the upper portion to the lower portion is formed on the outer circumferential surface of the second magnetic core 120 and the protrusions P of the third legs 112-4 and 114-4 are formed on the outer circumferential surface of the second magnetic core 120, As shown in Fig.

9, grooves G and protrusions P extending in the downward direction from the top are alternately formed on the inner peripheral surface of the second magnetic core 120, The protrusions P and the grooves G extending in the downward direction from the top are alternately formed on the outer circumferential surfaces of the legs 112-4 and 114-4 and the protrusions P can be inserted into the grooves G have.

10, at least one of the grooves G and the protrusions P formed on the hollow inner circumferential surface of the second magnetic core 120 is connected to the third legs 112-4 and 114-4 of the first magnetic core 110 And the protrusion P and the groove G formed on the outer circumferential surface of the protruding portion.

The coupling between the first magnetic core 110 and the second magnetic core 120 is increased so that the first magnetic core 110 and the second magnetic core 120 may be warped after a long period of use, The possibility that the first magnetic core 110 and the second magnetic core 120 are disassembled can be lowered.

According to the embodiment of the present invention, the permeability and the core loss rate can be controlled by adjusting the volume ratio of the first magnetic core 110 containing pure iron or Fe-based magnetic powder and the second magnetic core 120 containing ferrite powder .

11 shows the relationship between the magnetic permeability and the core loss ratio according to the volume ratio between the first magnetic core 110 and the second magnetic core 120. Table 1 shows the magnetic permeability and core loss ratio according to the volume ratio between the first magnetic core 110 and the second magnetic core 120, FIG. 12 is a graph showing the core loss ratio according to the volume ratio between the first magnetic core 110 and the second magnetic core 120. FIG.

The second magnetic core (Ni-Zn) (vol%) The first magnetic core (vol%) Permeability (μ) Core loss factor (Pcv) 0 100 60 140 5 95 77 135 10 90 94 130 15 85 111 125 20 80 128 120 25 75 145 115 30 70 162 110 35 65 179 105 40 60 196 100 45 55 213 95 50 50 230 90 55 45 247 85 60 40 264 80 65 35 281 75 70 30 298 70 75 25 315 65 80 20 332 60

The second magnetic core (Mn-Zn) (vol%) The first magnetic core (vol%) Permeability (μ) Core loss factor (Pcv) 0 100 60 140 5 95 557 134 10 90 1054 129 15 85 1551 123 20 80 2048 117 25 75 2545 111 30 70 3042 106 35 65 3539 100 40 60 4036 94 45 55 4533 88 50 50 5030 83 55 45 5527 77 60 40 6024 71 65 35 6521 65 70 30 7018 60 75 25 7515 54 80 20 8012 48

Referring to Tables 1 to 2 and FIGS. 11 to 12, various permeability and core loss ratios can be obtained depending on various volume ratios between the first magnetic core and the second magnetic core and the types of the materials included in the second magnetic core have.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

110: first magnetic core
112, 114: partial magnetic core
112-1, 114-1:
112-2, 114-2: first leg
112-3, 114-3: second leg
112-4, 114-4: third leg
120: second magnetic core

Claims (12)

A first magnetic core comprising a pure iron or Fe-based alloy, and
And a second magnetic core that is disposed to surround an outer circumferential surface of at least a part of the first magnetic core,
. ≪ / RTI > The method according to claim 1,
Wherein the first magnetic core includes a magnetic core, a first leg, a second leg, and a third leg integrally formed with the magnetic core, and the third leg is disposed between the first leg and the second leg A pair of partial magnetic cores,
Wherein the pair of partial magnetic cores are arranged to face each other,
Wherein each of the first leg, the second leg, and the third leg included in the first partial magnetic core, which is one of the pair of partial magnetic cores, includes a second one of the pair of partial magnetic cores, The second leg, and the third leg included in the first leg, the second leg, and the third leg. 3. The method of claim 2,
The second magnetic core includes a first leg included in each of the pair of partial magnetic cores, a second leg included in each of the pair of partial magnetic cores, and a third leg included in each of the pair of partial magnetic cores, And the outer circumferential surface of the magnetic core. The method of claim 3,
The second magnetic core includes two first legs each included in the pair of partial magnetic cores, two second legs each included in the pair of partial magnetic cores, and a pair of second magnetic cores And at least one outer circumferential surface of at least one of the two third legs. The method of claim 3,
Wherein the second magnetic core is formed with a hollow for surrounding the outer circumferential surface thereof,
And the hollow inner peripheral surface is in contact with the outer peripheral surface. 6. The method of claim 5,
Wherein at least one of a groove and a protrusion is formed on the inner circumferential surface of the hollow, and at least one of a protrusion and a groove corresponding to the groove and the protrusion corresponding to the groove and the protrusion formed on the inner circumferential surface of the hollow are formed on the outer circumferential surface. The method according to claim 6,
Wherein at least one of the groove and the protrusion formed on the inner circumferential surface of the hollow and the protrusion and the groove formed on the outer circumferential surface are formed in a direction extending from the top to the bottom. The method according to claim 6,
Wherein at least one of the groove and the protrusion formed on the inner circumferential surface of the hollow and the protrusion and the groove formed on the outer circumferential surface are formed in a threaded shape. The method according to claim 1,
And the second magnetic core comprises Ni-Zn ferrite or Mn-Zn ferrite. Magnetic core, and
And a coil wound on the magnetic core,
The magnetic core
A first magnetic core comprising a pure iron or Fe-based alloy, and
And a second magnetic core that is disposed to surround an outer circumferential surface of at least a part of the first magnetic core,
/ RTI >
And the coil is wound on the second magnetic core. 11. The method of claim 10,
Wherein the first magnetic core includes a magnetic core, a first leg, a second leg, and a third leg integrally formed with the magnetic core, and the third leg is disposed between the first leg and the second leg A pair of partial magnetic cores,
Wherein the pair of partial magnetic cores are arranged to face each other,
Wherein each of the first leg, the second leg, and the third leg included in the first partial magnetic core, which is one of the pair of partial magnetic cores, includes a second one of the pair of partial magnetic cores, The second leg, and the third leg included in the first leg, the second leg, and the third leg. 12. The method of claim 11,
The second magnetic core includes a first leg included in each of the pair of partial magnetic cores, a second leg included in each of the pair of partial magnetic cores, and a third leg included in each of the pair of partial magnetic cores, The outer circumferential surface of at least one of the outer circumferential surfaces.

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