KR102419961B1 - Inductor - Google Patents

Abstract

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

Description

inductor {INDUCTOR}

FIELD OF THE INVENTION The present invention relates to inductors, for example, power inductors.

An inductor, one of the coil components, is a typical passive device that removes noise by forming an electronic circuit along with resistors and capacitors.

The field of power inductors is largely divided into multilayer power inductors that apply ferrite powder and dielectric powder for GAP application, wire-wound power inductors that apply Cu coils inside a body made of metal powder, and metal coils grown on a substrate. It is classified as a thin film type power inductor manufactured by covering it with a sheet made of powder. There are advantages and disadvantages according to each method. The stacked type is economically advantageous, but disadvantageous for high current, the thin film type is easy to respond to high current and small size, and the winding type is easy to cope with high current and large capacity. There is a disadvantage in that it is economically disadvantageous because metal powder is applied.

In recent years, the main issue of power inductors is shifting from stacked type to thin-film or wire-wound type while seeking a direction to lower the unit price of metal powder in line with the trend toward miniaturization or high-capacity products. to be.

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

Japanese Patent Laid-Open No. 2007-067214

An object of the present invention is to provide an inductor having an excellent appearance while improving inductance and Isat characteristics by limiting the width of a substrate that is not covered by an internal coil.

An inductor according to an embodiment of the present invention includes a body including a substrate and an internal coil therein, and an external electrode disposed on an outer surface of the body and connected to the internal coil. The internal coil includes 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 an overlapping portion of the substrate covered by at least one of the first coil pattern and the second coil pattern and a remaining portion of the substrate. and an out-of-substrate residual portion adjacent to the outermost coil.

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

The present invention provides an inductor capable of preventing a decrease in reliability due to damage to an internal coil.

1 is a perspective view of an inductor according to an example of the present invention.
FIG. 2 is a cross-sectional view taken along line I-I' of FIG. 1 .
3(a) is a graph showing the change in inductance according to the change in the width of the residual part of the substrate among the remaining parts of the substrate, and FIG. 3(b) is a graph showing the Isat value according to the change in the width of the residual part in the substrate.
FIG. 4(a) is a graph showing changes in inductance according to a change in the width of the residual part of the substrate among the remaining parts of the substrate, and FIG. 4(b) is a graph showing the Isat value according to a change in the width of the residual part of the substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for a clearer description, and elements indicated by the same reference numerals in the drawings are the same elements.

And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the thickness is enlarged to clearly express various layers and regions, and components having the same function within the scope of the same idea are referred to as the same. It is explained using symbols.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, an inductor according to an 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 cross-sectional view taken along line I-I' of FIG. 1 .

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

The body 1 determines the outer shape of the inductor, and is not limited as long as it is a material exhibiting magnetic properties, and may be formed by filling, for example, ferrite or a metallic soft magnetic material.

The body 1 has an upper surface and a lower surface facing each other in the thickness (T) direction, first and second surfaces facing each other in the length (L) direction, and a third surface and a third surface facing each other in the width (W) direction. It may have a substantially hexahedral shape including four faces, but is not limited thereto.

An external 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, nickel (Ni), copper (Cu), tin (Sn), silver (Ag) alone or these It may be a conductive paste including an alloy of The method of forming the external electrode may be formed by performing a dipping method as well as printing according to the shape of the external electrode.

An internal coil 11 and a substrate 12 may be disposed inside the body.

The internal coil 11 includes a first coil pattern 11a disposed on one surface of the substrate. In addition, the internal coil may further include a second coil pattern 11b disposed on the other surface of the substrate. The magnetic core of the internal coil may be disposed parallel to a thickness direction of the body, and a first coil pattern, a substrate, and a second coil pattern among the internal coils may be disposed parallel to an upper surface or a lower surface of the body. In this case, the internal coil 11 sequentially includes a first coil pattern, a substrate, and a second coil pattern based on the thickness direction of the body.

The substrate 12 in the internal coil may be an insulating substrate having insulating properties. The substrate 12 is not particularly limited as long as it is a material capable of forming a coil pattern by, for example, electroplating, for example, it may be a polypropylene glycol (PPG) substrate, or include an epoxy resin, etc. It can be formed as a thin film.

The first coil pattern 11a disposed on one surface of the substrate and the second coil pattern 11b disposed on the other surface of the substrate each have a first lead-out portion exposed on one surface in the longitudinal direction of the body and the other surface in the length direction of the body. It may include a second lead-out unit.

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

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

Meanwhile, the first and second coil patterns respectively disposed on one surface and the other surface of the substrate may be symmetrical to each other. Here, symmetric means that the material of the coil pattern, the size including the width and thickness of the pattern part constituting the coil pattern, and the shape of the specific coil pattern coincide with each other, and when viewed from the upper surface of the body, the first coil pattern It may mean that the second coil pattern disposed on the opposite side is not visible, and the first coil pattern disposed on the opposite side to the second coil pattern is not visible when viewed from the lower surface of the body.

Meanwhile, referring to FIG. 2 , the substrate 12 includes a surface area that is not covered by at least one of the first and second coil patterns and is exposed, and is referred to as a substrate remaining portion 12a. Conversely, the substrate 12 includes a surface area covered by at least one of the first and second coil patterns, which is referred to as the substrate overlapping portion 12b.

Thin-film power inductor products implement characteristic values such as inductance and DC resistance by forming an internal coil on a substrate structurally. At this time, the remaining surface area of the substrate except for the surface area on which the coil is formed and fixed should be removed, and the present invention controls the area of the remaining substrate portion 12a that is not covered by the internal coil of the substrate. The substrate residual portion 12a includes a substrate internal residual part 121 and an external substrate residual part 122, wherein the internal substrate residual part is adjacent to an innermost coil of an internal coil, and the external substrate residual part is an internal coil It is adjacent to the outermost coil of

3(a) is a graph showing the change in inductance according to the change in the width of the residual part of the substrate among the remaining parts of the substrate, and FIG. 3(b) is a graph showing the Isat value according to the change in the width of the residual part in the substrate.

Referring to FIG. 3A , it can be seen that the inductance Ls decreases when the width of the remaining part of the substrate is changed from 0 μm to 60 μm. This means that as the area of the substrate remaining other than the surface area on which the internal coil is disposed increases, the effective internal area of the internal coil decreases and the inductance value decreases.

Similarly, referring to FIG. 3(b) , it can be seen that as the area of the remaining substrate other than the surface area on which the internal coil is disposed increases, the Isat characteristic also decreases.

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

Of course, in view of the electrical performance of the inductor, the most preferable embodiment is a case where the width of the residual portion in the substrate becomes 0 μm, so that the end of the innermost coil and the end of the substrate substantially coincide with each other. However, it is necessary to consider that this embodiment is somewhat difficult to realize without damage to the internal coil in the actual process.

Therefore, when removing the surface area of the substrate on which the internal coil is not disposed from the substrate to which the internal coil is fixed, the extent to which the substrate is removed without damaging the internal coil is preferably 20 µm or more and less than 60 µm in the width of the remaining part of the substrate. do. More preferably, the width of the remaining portion in the substrate may be 20 μm or more and 40 μm or less.

Next, FIG. 4(a) is a graph showing the change in inductance according to the change in the width of the remaining part of the substrate among the remaining parts of the substrate, and FIG. 4(b) is a graph showing the Isat value according to the change in the width of the residual part of the substrate.

Referring to FIG. 4A , it can be seen that the inductance Ls decreases when the width of the remaining part of the substrate is changed from 0 μm to 60 μm. This means that as the area of the substrate remaining other than the surface area on which the internal coil is disposed increases, the effective internal area of the internal coil decreases and the inductance value decreases.

Similarly, referring to FIG. 4(b) , it can be seen that the Isat characteristic also decreases as the area of the remaining substrate other than the surface area on which the internal coil is disposed increases.

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

Of course, in view of the electrical performance of the inductor, the most preferable embodiment is a case in which the width of the remaining portion of the substrate becomes 0 μm, so that the end of the innermost coil and the end of the substrate substantially coincide with each other. However, it is necessary to consider that it is somewhat difficult to realize without damage to the internal coil in the actual process.

Therefore, when removing the surface area on which the internal coil is not disposed from the substrate to which the internal coil is fixed, the extent to which the substrate is removed without damaging the internal coil is preferably 20 μm or more and less than 60 μm in the width of the remaining part of the substrate. More preferably, the width of the remaining portion outside the substrate may be 20 μm or more and 40 μm or less.

On the other hand, referring to FIGS. 3(b) and 4(b), as the width of the residual portion outside the substrate and the remaining portion inside the substrate increases, the characteristics (Ls and Isat) of the inductor decrease, and the width of the remaining portion outside the substrate is 0 μm. It can be seen that the Isat deviation according to the residual degree of the substrate is hardly visible when increasing from 40 μm to 40 μm. This may be because the residual portion outside the substrate is less affected by the core portion in which the magnetic core is formed compared to the remaining portion in the substrate. From this, of course, it is possible to make the width of the residual portion inside the substrate the same as the width of the remaining portion outside the substrate, and when they are different from each other, the width of the remaining portion in the substrate that is sensitively affected by the core portion is less affected by the residual portion outside the substrate. It can be seen that designing to be formed smaller than the negative width is a method to prevent reduction of the inductance value and the Isat characteristic.

Next, Table 1 below shows whether the internal coil is damaged by changing the width while making the width of the remaining portion inside the substrate the same as the width of the remaining portion outside the substrate.

Width of the remaining part in the substrate
(Same as the width of the remaining part outside the substrate) Whether the inner coil is damaged Product Applicability -10㎛ Damage to the inner coil surface not applicable 0㎛ Inner coil surface surface scratch (scratch) Applicable 10㎛ No internal coil damage Applicable 20㎛ No internal coil damage Applicable

Referring to Table 1, it can be seen that the width of the remaining portion inside the substrate or the width of the remaining portion outside the substrate is required to be 0 μm or more. However, since the width is 0 μm, the shape of the lower surface of the first coil pattern among the internal coils substantially matches the shape of the upper surface of the substrate, and the shape of the upper surface of the second coil pattern among the internal coils is substantially identical to the shape of the lower surface of the substrate , there is no reduction in inductance (Ls) or Isat characteristics, so the performance of the inductor may be excellent, but there may be a risk of scratching the surface of the inner coil surface during the process. However, the surface scratch is not an effect reaching the degree of reducing the appearance or electrical characteristics of the product. The surface scratch is generated during CO ₂ laser drilling in order to remove the surface area except for the overlapping portion of the substrate overlapping the inner coil.

Next, Table 2 below is a table that comprehensively evaluates Ls characteristics, Isat characteristics, internal coil damage, and product applicability by changing the width while making the width of the remaining part inside the substrate the same as the width of the remaining part outside the board .

Width of the remaining part in the substrate
(Same as the width of the remaining part outside the substrate) Ls characteristic Isat characteristics inner coil
Whether damage product application
Availability -10㎛ satisfied satisfied Dissatisfied (damaged) not applicable 0㎛ satisfied satisfied satisfied Applicable 20㎛ satisfied satisfied satisfied Applicable 40㎛ satisfied satisfied satisfied Applicable 60㎛ dissatisfaction dissatisfaction satisfied not applicable

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

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

Except for the above description, descriptions overlapping with the characteristics of the inductor according to an embodiment of the present invention described above 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 by the appended claims. Therefore, various types of substitution, modification and change will be possible by those skilled in the art within the scope not departing from the technical spirit of the present invention described in the claims, and it is also said that it falls within the scope of the present invention. something to do.

Meanwhile, the expression “one example” used in the present disclosure does not mean the same embodiment, and is provided to emphasize and explain different unique features. However, the examples presented above are not excluded from being implemented in combination with features of other examples. For example, even if a matter described in one specific example is not described in another example, it may be understood as a description related to another example unless a description contradicts or contradicts the matter in another example.

On the other hand, the terms used in the present disclosure are only used to describe an example, and are not intended to limit the present disclosure. In this case, the singular expression includes the plural expression unless the context clearly indicates otherwise.

100: inductor
1: body
11: inner coil
11a: first coil pattern
11b: second coil pattern
12: substrate
12a: the remaining part of the substrate
121, 122: a residual portion inside the substrate, a residual portion outside the substrate
12b: substrate overlapping portion

Claims (10)

a body including a substrate and an internal coil therein; and
an external electrode disposed on the outer surface of the body and connected to the inner coil; including,
The internal coil includes 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 that is at least a portion of both surfaces of the substrate in direct contact with the body; The part includes a residual part in the substrate adjacent to the innermost coil and a residual part in the substrate adjacent to the outermost coil among the internal coils,
The width of the remaining portion inside the substrate is smaller than the width of the remaining portion outside the substrate,
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According to claim 1,
The width of the remaining portion in the substrate is more than 0㎛ less than 60㎛,
inductor.
3. The method of claim 2,
The width of the remaining portion in the substrate is 20 μm or more and 40 μm or less,
inductor.
According to claim 1,
The width of the remaining portion outside the substrate is more than 0㎛ less than 60㎛,
inductor.
5. The method of claim 4,
The width of the remaining portion outside the substrate is 20 μm or more and 40 μm or less,
inductor.
delete delete The method of claim 1,
The first coil pattern and the second coil pattern are disposed symmetrically with respect to the substrate,
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According to claim 1,
An outermost coil pattern among the first coil patterns includes a first lead-out portion, and an outermost coil pattern among the second coil patterns includes a second lead-out portion,
The first lead-out part is connected to a first external electrode of the external electrodes, and the second lead-out part is connected to a second external electrode of the external electrodes.
inductor.
According to claim 1,
The substrate is a polypropylene glycol (PPG) substrate,
inductor.

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