KR20170097493A - Inductor - Google Patents

Abstract

The present invention relates to an inductor comprising: a body including a substrate and inner coils therein; and an external electrode disposed on an outer surface of the body and connected to the inner coils. The inner coils include a first coil pattern disposed on one surface of the substrate, and a second coil pattern disposed on the other surface of the substrate. The substrate includes a substrate overlapping portion covered by at least one of the first coil pattern and the second coil pattern, and a substrate remaining portion. The substrate remaining portion of the substrate includes a substrate inner remaining portion adjacent to the innermost coil among the inner coils and a substrate outer remaining portion adjacent to the outermost coil among the same.

Description

Inductor {INDUCTOR}

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

INDUCTOR, which is one of the coil parts, is a typical passive element that removes noise by forming an electronic circuit together with a resistor and a capacitor.

In the field of power inductors, there are a laminated power inductor that applies a dielectric powder for application to a ferrite powder and a gap (GAP), a coiled power inductor that applies a Cu coil to the inside of a body made of metal powder, And a thin film type power inductor which is covered with a sheet made of powder. They have advantages and disadvantages according to their respective methods. The stacking type is advantageous for economical advantage, while the stacking type is advantageous for high current. Thin film type is easy to cope with high current and small size, and the winding type is easy to cope with high current capacity. It is economically disadvantageous because metal powder is applied.

Recently, since the main power of the power inductor is shifted from the stacked type to the thin film type or the wound type in order to reduce the cost of the metal powder in accordance with the trend of miniaturization or high capacity of the product, the improvement of the characteristics of such thin film or wound type power inductor to be.

The following Patent Document 1 discloses a thin film type inductor that forms an inner coil pattern by plating on the upper and lower surfaces of an insulating substrate, but the specific size of the insulating substrate is not limited.

Japanese Patent Application Laid-Open No. 2007-067214

The present invention aims to provide an inductor having excellent appearance while improving inductance and Isat characteristics by limiting the width of a substrate not covered by the inner coil.

An inductor according to an exemplary embodiment of the present invention includes a substrate, a body including an inner coil therein, and an outer electrode disposed on an outer surface of the body and connected to the inner coil. The inner coil includes a first coil pattern disposed on one side of the substrate and a second coil pattern disposed on the other side of the substrate. The substrate includes a substrate overlap portion covered by at least one of a first coil pattern and a second coil pattern and a remaining substrate remaining portion. In this case, the substrate remaining portion includes a residual portion in the substrate adjacent to the innermost coil, And an out-substrate residual portion adjacent to the outermost coil.

The present invention provides an inductor capable of improving an inductance value and an Isat value of the entire chip even if an internal coil having the same condition is used.

The present invention provides an inductor that can prevent reliability degradation due to damage to an inner coil.

1 is a perspective view of an inductor according to an embodiment of the present invention.
2 is a cross-sectional view taken along line I-I 'of FIG.
Fig. 3 (a) is a graph showing inductance variation according to a change in the width of a remaining portion in a substrate remaining portion of the substrate, and Fig. 3 (b) is a graph showing Isat value according to a change in width of a remaining portion in the substrate.
FIG. 4A is a graph showing the inductance variation according to the width of the remaining portion of the substrate remaining portion in the substrate remaining portion, and FIG. 4B is a graph showing the Isat value according to the variation of the remaining portion of the substrate remaining portion.

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

Referring to FIG. 1, an inductor 100 includes a body 1 and an external electrode 2 disposed outside the body.

The body 1 determines the external shape of the inductor, and is not limited as long as it is a material exhibiting magnetic characteristics. For example, the body 1 can be formed by filling a ferrite or a metal-based soft magnetic material.

The body 1 has a first surface and a second surface facing each other in the direction of a length T and a top surface and a third surface facing each other in a width W direction, It may have a substantially hexahedral shape including, but not limited to, four sides.

The outer electrode 2 may be disposed on the outer surface of the body. The external electrode may be formed using a paste containing a metal having excellent electrical conductivity. For example, the external electrode may be formed of a metal such as nickel (Ni), copper (Cu), tin (Sn) Or the like, and the like. The method of forming the external electrode may be performed by not only printing but also dipping according to the shape of the external electrode.

The inner coil 11 and the substrate 12 may be disposed inside the body.

The inner coil 11 includes a first coil pattern 11a disposed on one side of the substrate. The inner coil may further include a second coil pattern 11b disposed on the other surface of the substrate. The magnetic core of the inner coil is disposed parallel to the thickness direction of the body, and the first coil pattern, the substrate, and the second coil pattern of the inner coil may be disposed parallel to the upper surface or the lower surface of the body. In this case, the inner coil 11 sequentially includes the first coil pattern, the substrate, and the second coil pattern with reference to the thickness direction of the body.

The inner coil inner substrate 12 may be an insulating substrate having an insulating property. The substrate 12 may be, for example, a polypropylene glycol (PPG) substrate, or may include an epoxy resin or the like. The substrate 12 may be made of any material capable of forming a coil pattern by electroplating, Or the like.

The first coil pattern 11a disposed on one surface of the substrate and the second coil pattern 11b disposed on the other surface are exposed to the first surface of the body, And a second lead-out portion.

The first and second coil patterns disposed on one surface and the other surface of the substrate may be electrically connected through a via electrode formed on the substrate.

A hole penetrating the substrate may be formed at a central portion of the substrate, and the hole may be filled with a magnetic material forming a body to form a core portion. The inductance can be improved by forming the core portion filled with the magnetic material.

Meanwhile, the first and second coil patterns disposed on one surface and the other surface of the substrate may be symmetrical to each other. Here, the symmetry means that the material of the coil pattern, the size including the width and thickness of the pattern portion constituting the coil pattern, and the shape of the specific coil pattern coincide with each other, and the first coil pattern The second coil pattern disposed on the opposite side to the second coil pattern is not visible and the first coil pattern disposed on the opposite side of the second coil pattern from the bottom surface of the body is not visible.

Referring to FIG. 2, the substrate 12 includes a surface region exposed without being covered by at least one of the first and second coil patterns, and is referred to as a substrate residual portion 12a. Conversely, the substrate 12 includes a surface region covered by at least one of the first and second coil patterns, which is referred to as a substrate superposition portion 12b.

Thin-film power inductors form internal coils on the substrate structurally to realize characteristics such as inductance and DC resistance. At this time, the surface area except for the surface area where the coil is formed and fixed in the substrate is to be removed. The present invention controls the area of the substrate residual part 12a which is not covered by the inner coil in the substrate. The substrate remaining portion 12a includes a remaining portion 121 in the substrate and a remaining portion 122 outside the substrate, the remaining portion in the substrate being adjacent to the innermost coil of the inner coil, And the outermost coil of the coil.

Fig. 3 (a) is a graph showing inductance variation according to a change in the width of a remaining portion in a substrate remaining portion of the substrate, and Fig. 3 (b) is a graph showing Isat value according to a change in width of a remaining portion in the substrate.

Referring to FIG. 3 (a), it can be seen that the inductance Ls decreases when the width of the remaining portion of the substrate in the substrate remaining portion is changed from 0 탆 to 60 탆. This means that the internal effective area of the inner coil decreases and the inductance value decreases as the area of the remaining substrate increases in addition to the surface area where the inner coil is disposed.

Similarly, referring to FIG. 3 (b), it can be seen that as the area of the remaining substrate increases in addition to the surface area where the inner coil is disposed, the Isat characteristic also decreases.

3 (a) and 3 (b), it can be seen that the inductance value and the Isat characteristic are not largely reduced when the width of the remaining portion in the substrate is 0 탆 or more and 60 탆 or less.

Of course, in terms of the electrical performance of the inductor, the most preferable embodiment to be implemented is a case in which the width of the remaining portion in the substrate becomes 0 mu m so that the end portion of the innermost coil and the end portion of the substrate substantially coincide with each other. However, it is necessary to consider that this embodiment is somewhat difficult to realize without damaging the inner coil in the actual process.

Therefore, when the surface area of the substrate on which the inner coil is not disposed is removed from the substrate to which the inner coil is fixed, the degree of removal of the substrate without damaging the inner coil is preferably 20 mu m or more and less than 60 mu m Do. More preferably, the width of the remaining portion in the substrate may be 20 占 퐉 or more and 40 占 퐉 or less. In this case, damage to the inner coil can be minimized while reducing the decrease of the inductance and Isat characteristics.

4 (a) is a graph showing changes in inductance according to changes in the width of the rest of the substrate remaining portion in the substrate remaining portion, and FIG. 4 (b) is a graph showing Isat values according to changes in the width of the rest portion outside the substrate.

Referring to FIG. 4A, it can be seen that the inductance Ls decreases when the width of the remaining portion of the substrate remaining portion in the substrate remaining portion is changed from 0 mu m to 60 mu m. This means that the internal effective area of the inner coil decreases and the inductance value decreases as the area of the remaining substrate increases in addition to the surface area where the inner coil is disposed.

Similarly, referring to FIG. 4 (b), it can be seen that as the area of the remaining substrate increases in addition to the surface area where the inner coil is disposed, the Isat characteristic also decreases.

4 (a) and 4 (b), it can be seen that the inductance value and the Isat characteristic are not largely reduced when the width of the remaining portion outside the substrate is 0 탆 or more and 60 탆 or less.

Of course, in view of the electrical performance of the inductor, the most preferred embodiment to be implemented is a case where the width of the residual portion outside the substrate is 0 占 퐉, so that the end of the innermost coil coincides substantially with the end of the substrate. However, it is necessary to consider that this is somewhat difficult to realize without damaging the inner coil in the actual process.

Therefore, when removing the surface area where the inner coil is not disposed on the substrate to which the inner coil is fixed, it is desirable that the width of the remaining portion outside the substrate is less than 20 mu m and less than 60 mu m to remove the substrate without damaging the inner coil. More preferably, the width of the residual portion outside the substrate may be 20 占 퐉 or more and 40 占 퐉 or less. In this case, damage to the inner coil can be minimized while reducing the decrease of the inductance and Isat characteristics.

3 (b) and FIG. 4 (b), the inductance characteristics (Ls and Isat) decrease as the width of the residual portion outside the substrate and the residual portion within the substrate increases. To 40 [mu] m, it can be seen that there is almost no Isat deviation according to the residual degree of the substrate. This may be because the remaining portion of the substrate is less influenced by the core portion in which the magnetic core is formed as compared with the remaining portion in the substrate. This makes it possible to make the width of the remaining portion in the substrate and the width of the remaining portion outside the substrate equal to each other. When the width of the remaining portion is less affected by the influence of the core portion, It is understood that designing to be smaller than the width of the inductance value and Isat characteristic is a method of preventing reduction of the inductance value and the Isat characteristic.

Next, Table 1 below shows the measurement of the damage of the inner coil by changing the width of the remaining portion of the substrate and the remaining portion of the substrate while making the width equal to each other.

Residual width in substrate
(The same as the remaining width of the substrate) Internal coil damage Applicability of products -10 탆 Damage to inner coil surface Not applicable 0 탆 Internal coil surface Part surface scratch Applicable 10 탆 No internal coil damage Applicable 20 탆 No internal coil damage Applicable

Referring to Table 1, it can be seen that the width of the remaining portion in the substrate or the width of the remaining portion outside the substrate is required to be 0 탆 or more. The shape of the lower surface of the first coil pattern of the inner coils substantially coincides with the shape of the upper surface of the substrate, and the shape of the upper surface of the second coil pattern of the inner coils differs from the shape of the lower surface of the substrate substantially , There is no decrease in inductance (Ls) and Isat characteristics, and the performance of the inductor can be excellent. However, there is a risk that scratches on the surface of the inner coil surface may occur in the process. However, surface scratches do not affect the appearance and electrical characteristics of the product. Surface scratches are generated when a CO ₂ laser drill is used to remove the surface area except the substrate overlap that overlaps the inner coil.

Table 2 below is a table comprehensively evaluating Ls characteristics, Isat characteristics, internal coil damage, and applicability of products by changing the widths of the remaining portions in the substrate and the remaining portions of the substrate while changing the widths .

Residual width in substrate
(The same as the remaining width of the substrate) Ls attribute Isat attribute Inner coil
Damaged Product Application
Availability -10 탆 satisfied satisfied Dissatisfied (damaged) Not applicable 0 탆 satisfied satisfied satisfied Applicable 20 탆 satisfied satisfied satisfied Applicable 40 탆 satisfied satisfied satisfied Applicable 60 탆 dissatisfaction dissatisfaction satisfied Not applicable

Referring to Table 2, it is preferable that the remaining width of the substrate or the width of the remaining portion of the substrate, which is free from problems in performance and appearance of the inductor, is 0 탆 or more and less than 60 탆. On the other hand, it is more preferable that the width of the remaining portion of the substrate or the width of the remaining portion of the substrate which does not significantly reduce the performance of the inductor without allowing even the surface scratch of the inner coil is 20 μm or more and 40 μm or less.

 According to an embodiment of the present invention, it is possible to provide an inductor capable of improving an inductance value and an Isat value of the entire chip even when an internal coil having the same condition is used, and preventing reliability degradation due to damage to the internal coil .

Except for the above description, the description of the inductor according to the exemplary embodiment of the present invention will be omitted here.

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: Body
11: inner coil
11a: first coil pattern
11b: second coil pattern
12: substrate
12a: Substrate residual portion
121, 122: Residual portion in the substrate, Residual portion on the substrate
12b: substrate overlap portion

Claims (10)

A body including a substrate and an inner coil therein; And
An outer electrode disposed on an outer surface of the body and connected to the inner coil; / RTI >
Wherein the inner coil includes a first coil pattern disposed on one side of the substrate and a second coil pattern disposed on the other side of the substrate,
Wherein the substrate includes a substrate overlap portion covered by at least one of a first coil pattern and a second coil pattern and a remaining substrate remaining portion, and a substrate remaining portion of the substrate includes a residual portion in the substrate adjacent to the innermost coil And an out-substrate residual portion adjacent the outermost coil,
Inductor.
The method according to claim 1,
Wherein a width of the remaining portion in the substrate is in a range of 0 占 퐉 to less than 60 占 퐉,
Inductor.
3. The method of claim 2,
Wherein the width of the remaining portion in the substrate is 20 占 퐉 or more and 40 占 퐉 or less,
Inductor.
The method according to claim 1,
Wherein a width of the remaining portion outside the substrate is in a range of 0 탆 to 60 탆,
Inductor.
5. The method of claim 4,
Wherein a width of the remaining portion outside the substrate is 20 占 퐉 or more and 40 占 퐉 or less,
Inductor.
The method according to claim 1,
The width of the remaining portion in the substrate and the width of the remaining portion of the substrate are the same,
Inductor.
The method according to claim 1,
Wherein the width of the remaining portion in the substrate is smaller than the width of the remaining portion outside the substrate,
Inductor.
The method according to claim 1,
Wherein the first coil pattern and the second coil pattern are symmetrically arranged with respect to the substrate,
Inductor.
The method according to claim 1,
Wherein the outermost coil pattern of the first coil pattern includes a first lead portion and the outermost coil pattern of the second coil pattern includes a second lead portion,
Wherein the first lead portion is connected to a first outer electrode of the outer electrodes and the second lead portion is connected to a second outer electrode of the outer electrodes,
Inductor.
The method according to claim 1,
Wherein the substrate is a polypropylene glycol (PPG) substrate,
Inductor.

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