KR101813359B1 - Inductor - Google Patents

Abstract

The present invention relates to a magnetic bearing having a coil having at least one lead portion and including a magnetic body including magnetic particles and an external electrode disposed on an outer surface of the magnetic body, To an inductor including an air gap.

Description

Inductor {INDUCTOR}

The present invention relates to an inductor, for example, to a power inductor.

With the recent miniaturization and high performance of electronic devices, CPUs and various LSIs are becoming high-performance and high-frequency signals, but the power consumption increases accordingly. The operating voltage tends to be lowered at the request of such high efficiency and the operating current is increasing.

Therefore, the basic design direction of the power inductor is to suppress the change of the L value according to the current by improving the DC-Bias characteristic and to develop the magnetic material and improve the inductor structure to improve the DC-Bias characteristic It is true.

The following Patent Document 1 discloses inserting a separate nonmagnetic layer in order to improve the structure defect of the inductor. However, it is necessary to add a nonmagnetic layer and additional material design, There is a problem that the production process is difficult to be simplified.

U.S. Patent Application Publication No. 2011-0095856

The present invention attempts to improve the DC-Bias characteristics of an inductor by forming an air gap having an excellent gap characteristic without a separate design change in a conventional inductor.

According to an embodiment of the present invention, there is provided an inductor including a magnetic body embedded with a coil having at least one lead portion and including magnetic particles, and an external electrode disposed on an outer surface of the magnetic body. In this case, the magnetic body includes an air gap having a cavity therein, and the abrupt rate of change of the inductance through the air gap is reduced, thereby improving the DC-Bias characteristic.

The present invention can provide an inductor having an air gap excellent in gap characteristic.

The present invention can provide an inductor having an excellent air gap without any additional structural design and material design changes.

The present invention can provide an inductor having excellent DC-Bias characteristics.

INDUSTRIAL APPLICABILITY The present invention can provide an inductor capable of reducing the production cost by reducing the material cost by using an air gap instead of the conventional nonmagnetic body sheet.

1 is a schematic perspective view of an inductor according to one example of the present invention.
2 is a cross-sectional view taken along line I-I 'of FIG.
3 is a graph showing DC-Bias characteristics of an inductor according to an example of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements.

It is to be understood that, although the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Will be described using the symbols.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Hereinafter, an inductor according to an exemplary embodiment of the present invention will be described, but the present invention is not limited thereto.

Inductor

FIG. 1 is a schematic perspective view of an inductor according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line I-I 'of FIG. 1. Referring to FIG.

Referring to FIG. 1, an inductor 100 according to an embodiment of the present invention includes a magnetic body 1 and an external electrode 2 disposed on an outer surface of the magnetic body.

Referring to FIG. 1, the magnetic body 1 fills the inside of the inductor while forming the outline of the inductor. The magnetic body 1 may be formed by mixing a magnetic particle and a resin. The magnetic body 1 has a first surface and a second surface facing each other in the direction of the length (L), an upper surface and a lower surface facing each other in the thickness T direction, a third surface facing each other in the width W direction, But it is not limited thereto, and it may have a substantially hexahedral shape including a fourth surface.

On the other hand, the magnetic body 1 may have a laminated structure in which a plurality of magnetic sheets in which magnetic particles and resin are mixed are laminated. Such a laminated structure can not be distinguished from the outside as a plurality of magnetic sheets become integral with each other.

The magnetic particles contained in the magnetic body 1 may include a cut surface at least a part of which is cut. In this case, the cut surface of the magnetic particle, at least a portion of which is cut, may be disposed so as to be in contact with the outer surface of the magnetic body. This may mean that the cut surface of the metal particles contained in the body coincides with the outer surface of the body.

Also, on the outer surface of the outer surface of the magnetic body 1 on which the outer electrode is disposed, magnetic particles may be removed to provide an empty space. In this case, the surface roughness of the outer surface of the magnetic body becomes large, and the adhesive strength can be enhanced when the outer electrode is disposed thereon.

The shape of the outer surface of the magnetic body, for example, the shape in the case where the magnetic particle is removed to have an empty space, and the shape in which at least a part of the magnetic particle is cut and the outer surface are in contact, And the like. The process of forming the magnetic body is a process of placing a coil having a winding structure on a support frame having a predetermined void space and stacking and pressing a plurality of magnetic sheets on the upper and lower surfaces of the coil to form a lamination bar bar, and cutting the laminated bar into separate bodies, but the present invention is not limited thereto.

Referring to FIG. 2, a coil 11 having a winding structure may be embedded in the magnetic body. The coil has at least one lead portion and is formed in a spiral shape, but is not limited thereto.

The coil 11 may be disposed in the center of the magnetic body, or may be disposed so as to be offset to the upper or lower end of the magnetic body according to design or manufacturing process needs.

The outer electrode 2 may be disposed on the outer surface of the magnetic body and may extend over the entire area of the first surface and the second surface facing each other in the length L direction of the magnetic body as shown in FIG. , But is not limited thereto. The external electrode may be made of a material having excellent electrical conductivity, for example, Ag, Cu, Ni, Sn, Pt, an alloy thereof, or the like.

An air gap 12 having a cavity of an empty space may be disposed inside the magnetic body.

The air gap 12 may be disposed on the same plane as the lower surface of the coil, but is not limited thereto.

It is preferable that the air gap 12 be disposed inside the innermost coil pattern of the coil and not disposed outside the outermost coil pattern. In this case, the air gap 12 is disposed to effectively block the magnetic flux generated in the inductor, and the abrupt change rate of the inductance is reduced, and the appearance of the magnetic body is not affected at all, can do.

The air gap 12 may be formed at a predetermined distance from the innermost layer coil pattern of the coils, but is not limited thereto.

A plurality of the air gaps 12 may be formed if necessary for the structural design and the characteristics of the inductor, but it is of course also possible to have a single air gap as shown in FIG.

FIG. 3 is a graph illustrating DC-Bias characteristics of an inductor according to an exemplary embodiment of the present invention. Referring to FIG. 3, an inductor according to an exemplary embodiment of the present invention includes an air gap, Bias characteristics are described.

Referring to FIG. 3, an inductor formed with an air gap according to an exemplary embodiment of the present invention has a lower rate of inductance change than an inductor having no gap formed therein. Although not shown in FIG. 3, an inductor formed with an air gap exhibits a DC-Bias characteristic similar to that of an inductor in which a gap is formed by inserting a non-conductive nonmagnetic sheet.

This means that the inductor according to an embodiment of the present invention effectively blocks the magnetic flux generated from the coil of the inductor even if an air gap is used in place of the non-magnetic sheet, thereby preventing a sharp decrease in inductance. According to the existing method, when inserting the non-magnetic sheet, a separate material design and structure design are required, and an air gap having an excellent gap characteristic is formed without a complicated additional process.

The method of forming the air gap 12 is not particularly limited. However, as a method of forming a gap of a conventional inductor, there is a method of improving the DC-Bias characteristic by inserting a nonmagnetic sheet between the magnetic sheets . For example, when the plurality of magnetic sheets are laminated and pressed, the air gap 12 can control the adhesive force between the magnetic sheets by adjusting the characteristics of the curing agent, the solvent, and the curing degree of the individual magnetic sheets, Can be formed by using the difference in the coefficient of thermal expansion between them. In this case, due to the difference in the shrinkage ratio of the interface between adjacent magnetic sheets at the time of sintering and firing, a cavity is formed inside, and this cavity acts as an air gap to block the magnetic flux.

According to an embodiment of the present invention, there is provided a non-magnetic sheet which has an air gap having an excellent gap characteristic without a separate structural design and a change in material design, has excellent DC-Bias characteristics, It is possible to provide an inductor capable of reducing the production cost by reducing the material cost by using the gap.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited only by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

In the meantime, the expression "an example" used in this disclosure does not mean the same embodiment but is provided for emphasizing and explaining different unique features. However, the above-mentioned examples do not exclude that they are implemented in combination with the features of other examples. For example, although a matter described in a particular example is not described in another example, it may be understood as an explanation related to another example, unless otherwise stated or contradicted by that example in another example.

On the other hand, the terms used in this disclosure are used only to illustrate an example and are not intended to limit the present disclosure. Wherein the singular expressions include plural expressions unless the context clearly dictates otherwise.

100: inductor
1: magnetic body
2: external electrode
11: Coil
12: Air gap

Claims (10)

A magnetic body embedded with a coil having at least one lead portion, the magnetic body including magnetic particles; And
An external electrode disposed on an outer surface of the magnetic body; / RTI >
The magnetic body includes an air gap having a cavity therein,
Wherein the air gap is disposed on the same plane as the lower surface of the coil,
Inductor.
The method according to claim 1,
Wherein the magnetic body has a laminated structure in which a plurality of magnetic sheets are laminated,
Inductor.
The method according to claim 1,
Wherein at least part of the outer surface of the magnetic body is disposed on the outer surface on which the outer electrode is disposed,
Inductor.
The method according to claim 1,
Wherein the coil has a winding structure,
Inductor.
delete The method according to claim 1,
Wherein the air gap is disposed inside the innermost coil pattern of the coil,
Inductor.
The method according to claim 1,
The coefficient of thermal expansion of the magnetic sheet disposed above the air gap is different from the coefficient of thermal expansion of the magnetic sheet disposed below the air gap,
Inductor.
The method according to claim 1,
Wherein the air gap is not formed outside the outermost coil pattern of the coils,
Inductor.
The method according to claim 1,
Wherein at least two air gaps are formed,
Inductor.
The method according to claim 1,
Wherein the air gap is formed at a predetermined distance from the innermost coil pattern of the coils,
Inductor.

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