KR20150080800A - Inductor - Google Patents

Abstract

The present invention relates to an inductor. The inductor includes a body in which a conductive coil is formed; first and second external electrodes extended from a part of a longitudinal direction of both sides of the body to a part of a longitudinal direction of an undersurface of the body, and electrically connected to the conductive coil; and an insulating layer formed to cover an upper part of the first and second external electrodes formed on both sides of the body. Therefore, according to the present invention, the inductor is able to have improved reliability by preventing a short circuit.

Description

Inductor {Inductor}

The present disclosure relates to inductors.

Inductors are one of the important passive components in electronic circuits with resistors and capacitors, and are used in various systems and components such as low noise amplifiers, mixers, voltage controlled oscillators and matching coils.

Such an inductor can be classified into a wound type inductor, a stacked type inductor, and a thin film type inductor according to its structure.

Among them, the wound type inductor can be formed by winding a coil on a ferrite core or the like.

Such a coiled inductor may cause stray capacitance between the coils, so that the number of turns of the coil must be increased to obtain a high-capacity inductance. If the number of turns of the coil increases, the high-frequency characteristics deteriorate.

The laminated type inductor can be formed by laminating a plurality of ceramic sheets.

The multilayered inductor has a coil-shaped metal pattern formed on each ceramic sheet, and the metal patterns are sequentially connected by a plurality of conductive vias provided in the respective ceramic sheets, ≪ / RTI >

The stacked inductor is suitable for mass production by such a structure and can have excellent high-frequency characteristics as compared with the wound-type inductor.

However, when the material constituting the metal pattern has a low saturation magnetization value and is fabricated in a small size, the number of stacked metal patterns is limited, and therefore, the DC superposition characteristic is lowered and sufficient current is obtained There is a problem that it can not be done.

The thin film type inductor can be manufactured by forming a thin conductive coil on a coil supporting layer.

Since the thin film type inductor can use a material having a high saturation magnetization value as compared with the stacked inductor, it is easy to form an internal circuit pattern without having a limit on height when manufactured in a small size. Are being studied actively.

Particularly, due to the high performance of mobile devices such as smart phones and tablet PCs, as the screen displayed increases, the APU speed increases and the power consumption increases due to the use of dual or quad core. Therefore, a DC- a thin film type inductor mainly used for a noise filter and the like is required to be able to realize a low direct current resistance with high inductance.

In addition, miniaturization and thinning of various electronic devices are accelerating with the development of IT technology, and therefore, the thin film type inductors used in such electronic devices are also required to be made smaller and thinner.

On the other hand, in the case of the power inductor, the body of the chip is made as large as possible in order to increase the conversion efficiency of the DC-DC converter. However, as the cell phone is made thinner and smaller, the size thereof is limited.

Particularly, in the case of an IC, since the metal case is covered and sealed, a margin portion of the inductor must be secured to prevent interference with the metal case. Therefore, there is a problem that the thickness of the power inductor must be further reduced.

The following prior art document discloses a chip-type coil component.

Korea Patent Publication No. 2012-0122589

The present disclosure aims to provide an inductor with improved reliability.

In one embodiment of the present disclosure, a body having a conductive coil formed therein; First and second external electrodes extending from a portion of the body in a height direction on both sides of the body to a portion of the body in a longitudinal direction thereof and electrically connected to the conductive coil; And an insulating layer formed to cover upper ends of the first and second external electrodes formed on both sides of the body.

In one embodiment, the insulating layer may include an Fe-based metal magnetic powder.

In one embodiment, the insulating layer may include 30 to 60 vol% of an epoxy resin as a subcomponent with respect to the main component when the Fe-based metal magnetic powder is referred to as a main component.

In one embodiment, the insulating layer may be formed to cover the upper surface of the body.

In one embodiment, the first and second external electrodes may be formed at a central portion in the width direction of the body.

The inductor according to one embodiment of the present invention has an insulating layer formed so as to cover the upper end of the L-shaped outer electrode, thereby preventing a short circuit from occurring due to contact with a metal case even when an impact is applied from the outside, .

In addition, the inductor according to one embodiment of the present disclosure can prevent the plating from spreading to the upper surface along the surface of the external electrode in the plating process by forming the insulating layer so as to cover the upper end of the L-shaped external electrode.

Figure 1 shows a schematic perspective view of an inductor according to one embodiment of the present disclosure.
Fig. 2 shows a schematic cross-sectional view along AA 'in Fig.
Figure 3 schematically shows a top view of a coil pattern of an inductor according to one embodiment of the present disclosure;

Hereinafter, embodiments of the present invention will be described in detail with reference to the 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.

FIG. 1 shows a schematic perspective view of an inductor according to an embodiment of the present disclosure, FIG. 2 shows a schematic cross-sectional view along AA 'in FIG. 1, and FIG. 3 shows a schematic Lt; / RTI >

1 to 3, an inductor according to an embodiment of the present disclosure may include a body 10 and first and second external electrodes 51 and 52.

In the following description, "L direction", "W direction", and "T direction" in FIG. 1 are set as "width direction" and "thickness direction", respectively.

The body 10 may be a rectangular parallelepiped and includes upper and lower cover layers 11 and 12 made of a magnetic material and a substrate 40 disposed between the upper and lower cover layers 11 and 12, And first and second coil layers 20 and 30 which are respectively formed on both surfaces and one end of which is electrically connected to the first and second external electrodes 51 and 52, respectively.

The first and second coil layers 20 and 30 may be conductive coils.

Although FIG. 3 shows only the first coil layer 20, the second coil layer 30 may also be formed to correspond thereto.

The first coil layer 20 may be formed on the substrate 40 with a conductive paste to form a coil pattern 21 in a spiral shape as shown in FIG.

The first coil layer 20 may be electrically connected to the second external electrode 52 through the coil lead-out portion 22. [

The first coil layer 20 may also be electrically connected to the second coil layer 30 through the conductive vias 60 of the connection portion 23.

That is, the first coil layer 20 and the second coil layer 30 may be electrically connected to the first and second external electrodes 51 and 52, respectively, as described above.

The first coil layer 20 and the second coil layer 30 are formed of the helical coil pattern 21, so that a magnetic flux may be generated when a current flows.

The core 13 may be formed at the center of the first and second coil layers 20 and 30.

The upper and lower cover layers 11 and 12 may be made of a paste composed of a ferrite or a composite of a metal magnetic powder and a polymer or may be made of a substrate containing a magnetic material such as nickel-zinc-copper ferrite.

The upper and lower cover layers 11 and 12 can prevent the basic electrical characteristics of the first and second coil layers 20 and 30 from being degraded.

The first and second external electrodes 51 and 52 are metals which can impart electrical conductivity and include at least one metal selected from the group consisting of gold, silver, platinum, copper, nickel, palladium and alloys thereof .

The first and second external electrodes 51 and 52 may extend from a portion of the side surface of the body 10 in the height direction to a portion of the bottom surface of the body 10 in the longitudinal direction.

The first and second outer electrodes 51 and 52 are formed to have a lower height than the upper surface of the body 10 so that the first and second outer electrodes 51 and 52 are made of a metal material It is possible to prevent the occurrence of a short circuit and improve the reliability.

The substrate 40 may be made of, for example, an insulating material such as a photosensitive polymer or a substrate made of a magnetic material such as ferrite.

The first and second coil layers 20 and 30 are electrically insulated from each other by the conductive vias 60. The first and second coil layers 20 and 30 are electrically insulated from each other, .

The conductive vias 60 may be formed by forming a through-hole through the substrate 40 in the thickness direction, and then filling the through-hole with a conductive paste.

Although the body of the inductor is made as large as possible in order to increase the conversion efficiency of the DC-DC converter of the inductor, the size of the inductor is limited as the cell phone becomes thinner and smaller.

Particularly, in the case of an IC, since a metal case is covered and sealed, a margin portion of the inductor must be secured in order to prevent interference with the metal case. Therefore, there is a problem that the thickness of the power inductor must be further reduced.

In order to solve the above problems, the inductor according to an embodiment of the present disclosure includes an insulating layer (not shown) formed to cover the upper ends of the first and second external electrodes 51 and 52 formed on both sides of the body 10 70 may be formed.

Since the inductor according to the embodiment of the present disclosure is formed such that the first and second external electrodes 51 and 52 are lower in height than the upper surface of the body 10, The external electrodes 51 and 52 are brought into contact with the metal case to prevent short-circuiting, thereby improving reliability.

The insulating layer 70 is formed so as to cover the upper ends of the first and second outer electrodes 51 and 52 so that the first and second outer electrodes 51 and 52 come into contact with the metal case, It is possible to further prevent the occurrence of the abnormality, thereby improving the reliability.

Particularly, in order to mount and use the inductor, a plating layer is formed on the outer electrodes 51 and 52 of the inductor. Such a plating spreading phenomenon occurs in which the plating layer spreads to the upper surface of the body 10 with the outer electrode.

When plating spreading phenomenon occurs, the upper surface of the body 10 and the metal case may come into contact with each other to cause a short circuit.

However, since the inductor according to one embodiment of the present disclosure has the insulating layer 70 formed to cover the upper ends of the first and second external electrodes 51 and 52, the plating blur can be prevented .

The insulating layer 70 may be formed to cover the upper surface of the body 10.

The first and second external electrodes 51 and 52 may be formed at a central portion in the width direction of the body 10 to prevent short-circuiting between the first and second external electrodes 51 and 52 adjacent to each other.

Since the first and second external electrodes 51 and 52 are formed at the central portion in the width direction of the body 10 so that the external electrodes 51 and 52 are not formed at the side edges of the body 10, It is possible to prevent short-circuiting between adjacent inductors.

In order to improve the performance of the inductor, the insulating layer 70 should have excellent insulating properties, uniform conformality, permeability, and adhesion.

For example, the insulating layer 70 according to one embodiment of the present disclosure may be formed using an epoxy resin.

That is, the insulating layer 70 may be formed using an insulating paste containing an epoxy resin.

The epoxy resin is not plated in the plating process and sufficient insulation can be ensured so that the epoxy resin is insulated from the metal case even after surface mounting of the inductor.

Further, since the epoxy resin is excellent in adhesion, it is possible to prevent the insulating layer 70 from falling off the body 10 even when an impact is applied to the inductor.

The epoxy resin can be formed by adjusting the viscosity of the insulating paste to 60 to 150 pa s using a viscosity adjusting agent in order to improve the uniform coating property.

Furthermore, in order to increase the magnetic permeability of the inductor, the insulating layer 70 may include an Fe-based metal magnetic powder.

When the insulating layer 70 is formed on the upper surface of the body 10, the magnetic permeability of the inductor increases when the insulating layer 70 includes the Fe-based metal magnetic powder.

The increase of the permeability of the inductor and the plating blurring phenomenon are shown in Table 1 below.

*: Comparative Example

The Fe-based metal magnetic body powder used in Table 1 was an amorphous Fe-based metal magnetic body powder having an average particle diameter of 8 μm.

The epoxy resin was used in a mixture of Phenoxy: PBPA: Novolac: phenol curing agent of 31.4: 31.4: 15.7: 21.4.

Table 1 is prepared by measuring whether or not plating spreading occurs after plating after forming an insulating layer using 1 to 10 insulating paste.

Referring to Table 1, when the content of the epoxy resin is 30 to 60 vol%, the inductor has a high capacity and can prevent the plating blur.

For example, when the content of the epoxy resin is less than 30 vol%, plating spreading occurs and the plating spreads to the upper portion of the body along the external electrode.

That is, when the content of the epoxy resin is less than 30 vol%, reliability of the inductor is lowered due to plating smear.

On the other hand, if the content of the epoxy resin exceeds 60 vol%, the amount of the magnetic material powder in the insulating layer is relatively reduced, and the capacity increasing effect of the inductor is reduced.

Therefore, when the Fe-based metal magnetic powder is referred to as a main component in order to increase the capacity of the inductor and improve the reliability at the same time, the content of the epoxy resin as a subcomponent with respect to the main component may be 30 to 60 vol%.

In addition, as shown in Table 1, an Fe-based metal magnetic powder can be used to increase the capacity of the inductor.

The present invention is not limited to the above-described embodiment and the accompanying drawings, but is intended to be limited 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.

10: Body
11: upper cover layer
12: Lower cover layer
13: Core
20: first coil layer
30: second coil layer
40: substrate
51: first outer electrode
52: second outer electrode
60: conductive vias
70: Insulation layer

Claims (5)

A body having a conductive coil formed therein;
First and second external electrodes extending from a portion of the body in a height direction on both sides of the body to a portion of the body in a longitudinal direction thereof and electrically connected to the conductive coil; And
And an insulating layer formed to cover upper ends of the first and second external electrodes formed on both sides of the body.
The method according to claim 1,
Wherein the insulating layer comprises an Fe-based metal magnetic powder.
3. The method of claim 2,
When the insulating layer is made of a Fe-based metal powder as a main component,
And an inductor containing 30 to 60 vol% of an epoxy resin as a subcomponent with respect to the main part.
The method according to claim 1,
Wherein the insulating layer is formed to cover an upper surface of the body.
The method according to claim 1,
Wherein the first and second external electrodes are formed at a central portion in the width direction of the body.

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