KR102047561B1

KR102047561B1 - Chip electronic component and board having the same mounted thereon

Info

Publication number: KR102047561B1
Application number: KR1020140062214A
Authority: KR
Inventors: 정정혁; 방혜민; 김태영; 차혜연
Original assignee: 삼성전기주식회사
Priority date: 2014-05-23
Filing date: 2014-05-23
Publication date: 2019-11-21
Also published as: KR20150134858A

Abstract

The present invention provides a magnetic body including an insulating substrate and a coil conductor pattern formed on at least one surface of the insulating substrate; And external electrodes formed at both ends of the magnetic body so as to be connected to an end of the coil conductor pattern, wherein the coil conductor pattern is formed by plating, and an upper surface of the coil conductor pattern in a longitudinal cross section of the magnetic body. When the angle formed by the tangent between the side and the side is θ, a chip electronic component satisfying 90.5 ° ≦ θ ≦ 103 ° is provided.

Description

Chip electronic component and board having the same mounted thereon

The present invention relates to a chip electronic component and its mounting substrate.

An inductor, one of the electronic components of a chip, is a typical passive element that removes noise by forming an electronic circuit together with a resistor and a capacitor, and amplifies a specific frequency band signal by combining with a capacitor using electromagnetic characteristics. It is used for the structure of a resonance circuit, a filter circuit, etc.

Recently, miniaturization and thinning of IT devices such as various communication devices or display devices have been accelerated, and various devices such as inductors, capacitors, and transistors employed in such IT devices have also been continuously researched to miniaturize and thin. . Accordingly, the inductor has been rapidly switched to a chip capable of compact and high-density automatic surface mounting, and developed a thin film inductor formed by mixing magnetic powder with a resin on a coil pattern formed by plating on upper and lower surfaces of a thin film insulating substrate. This is followed.

The thin film inductor is manufactured by forming a coil pattern on an insulating substrate and then filling a magnetic material to the outside.

The existing coil pattern structure has a round shape, and when the lead wire plating is applied, the upper surface of the coil pattern becomes round. When the cross-sectional area of the coil pattern is observed, the area is smaller than that of the coil pattern having a rectangular cross-sectional shape of which the upper surface is straight because the upper surface is round.

On the other hand, the area of the plating is important to improve the DC resistance (Rdc) of the important properties of the inductor, the closer to the square has a larger area occupying the same space has the effect of improving the DC resistance (Rdc). .

Also, anisotropic plating is designed so that plating can only grow in the direction above the coil due to the high current density.

However, as the plating proceeds under high current density, a ballistic shape appears at the end of the coil pattern due to the lack of copper (Cu) ion supply according to the speed, and the thickness variation between the coil patterns is also large, and a method of improving this is required.

Therefore, studies to improve the ballistic shape of the coil pattern, variation in plating thickness and short defects continue to be required, as well as research to improve the direct current resistance (Rdc) of the inductor.

Japanese Laid-Open Publication No. 1999-204337

In order to solve the above problems, an embodiment of the present invention,

A magnetic body including an insulating substrate and a coil conductor pattern formed on at least one surface of the insulating substrate; And external electrodes formed at both ends of the magnetic body so as to be connected to an end of the coil conductor pattern, wherein the coil conductor pattern is formed by plating, and an upper surface of the coil conductor pattern in a longitudinal cross section of the magnetic body. When the angle formed by the tangent between the side and the side is θ, a chip electronic component satisfying 90.5 ° ≦ θ ≦ 103 ° is provided.

An upper surface of the coil conductor pattern may be flat.

An aspect ratio (A / R) of the coil conductor pattern may be 1.5 to 5.5.

The coil conductor pattern portion is any selected from the group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). It may include one or more.

In addition, another embodiment of the present invention is a magnetic body including an insulating substrate and a coil conductor pattern formed on at least one surface of the insulating substrate; And external electrodes formed at both ends of the magnetic body to be connected to an end of the coil conductor pattern. Wherein the coil conductor pattern is formed by plating, and when the bottom surface length of the coil conductor pattern is c and the top surface length is b in the longitudinal section of the magnetic body, 0.02 ≦ b / c ≦ 0.98 is satisfied. Provides chip electronic components.

When the length of the center portion of the coil conductor pattern is a, 0.02 ≦ b / a ≦ 0.98 may be satisfied.

When the angle formed by the tangent between the upper surface and the side surface of the coil conductor pattern in the longitudinal cross section of the magnetic body is θ, 90.5 ° ≤ θ ≤ 103 ° may be satisfied.

An upper surface of the coil conductor pattern may be flat.

An aspect ratio (A / R) of the coil conductor pattern may be 1.5 to 5.5.

The coil conductor pattern is any one selected from the group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). It may include one or more.

In addition, another embodiment of the present invention is a printed circuit board having a first and a second electrode pad on the top; And the chip electronic component installed on the printed circuit board.

According to the chip electronic component of the embodiment of the present invention, since the coil conductor pattern has a cross-sectional shape close to a quadrangle, the coil cross-sectional area is maximized as compared to the existing coil structure, thereby minimizing the DC resistance Rdc.

In addition, since the coil conductor pattern has a cross-sectional shape close to a square, the spacing between adjacent coils is almost the same, and the distance from the substrate is almost the same because the upper surface is planar, unlike the existing coil pattern having a dome shape. .

Therefore, according to the chip electronic component of one embodiment of the present invention, the plating thickness variation is small, the short defect can be improved, and the reliability is excellent.

1 is a schematic perspective view illustrating an internal coil pattern of a chip electronic component according to an exemplary embodiment of the present disclosure.
FIG. 2 is a cross-sectional view taken along line II ′ of FIG. 1.
3 is an enlarged schematic view of an embodiment of portion A of FIG. 2.
4 is an enlarged schematic view of another embodiment of part A;
5 is a scanning electron microscope (SEM) photograph of an enlarged observation of a coil conductor pattern portion of a chip electronic component according to an exemplary embodiment of the present disclosure.
6 is a perspective view illustrating a board in which the chip electronic component of FIG. 1 is mounted on a printed circuit board.

Embodiments of the invention may be modified in many different forms and should not be construed as limited to the embodiments set forth herein. In addition, embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and thicknesses are exaggerated in order to clearly express various layers and regions. It demonstrates using a sign.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

Hereinafter, a chip electronic component according to an exemplary embodiment of the present invention will be described, but a thin film inductor will be described, but is not limited thereto.

1 is a schematic perspective view showing an internal coil pattern of a chip electronic component of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1, and FIG. 3 is an 'A' of FIG. 2. It is a schematic diagram which expands and shows one Embodiment of a part.

1 to 3, as an example of a chip electronic component, a thin film type chip inductor 100 used in a power line of a power supply circuit is disclosed. The chip electronic component may be suitably applied to chip beads, chip filters, and the like.

The thin film inductor 100 includes a magnetic body 50, an insulating substrate 23, and coil conductor patterns 42 and 44.

The magnetic body 50 forms the appearance of the thin film inductor 100 and is not limited as long as the material exhibits magnetic properties. For example, the magnetic body 50 may be filled with a ferrite or a metal-based soft magnetic material. As the ferrite, Mn-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Zn-Cu-based ferrite, Mn-Mg-based ferrite, Ba-based ferrite or Li-based ferrite may be used, Fe-Si-B-Cr based amorphous metal powder material may be used, but is not limited thereto.

The magnetic body 50 may have a hexahedron shape, and in order to clarify the embodiments of the present invention, the direction of the hexahedron is defined, and L, W, and T shown in FIG. 1 may be a length direction, a width direction, and a thickness direction, respectively. Indicates. The magnetic body 50 may have a shape of a rectangular parallelepiped in which the length in the longitudinal direction is larger than the length in the width direction.

The insulating substrate 23 formed inside the magnetic body 50 is formed of a thin thin film and is not particularly limited as long as it is a material capable of forming the coil conductor patterns 42 and 44 by plating. It may be formed of a substrate, a ferrite substrate, a metal-based soft magnetic substrate and the like.

A central portion of the insulating substrate 23 may be formed to form a hole, and the hole may be filled with a magnetic material such as ferrite or a metal soft magnetic material to form a core part. As the core part filled with the magnetic material is formed, inductance L may be improved.

A coil conductor pattern 42 having a coil-shaped pattern may be formed on one surface of the insulating substrate 23, and a coil conductor pattern 44 having a coil-shaped pattern may be formed on an opposite surface of the insulating substrate 23. Can be formed.

The coil conductor patterns 42 and 44 may include a spiral coil pattern, and the coil conductor patterns 42 and 44 formed on one surface opposite to the insulating substrate 23 may be formed on the insulating substrate. It can be electrically connected through the via electrode 46 formed in the (23).

The coil conductor patterns 42 and 44 and the via electrode 46 may be formed of a metal having excellent electrical conductivity. For example, silver (Ag), palladium (Pd), aluminum (Al), and nickel (Ni) may be formed. ), Titanium (Ti), gold (Au), copper (Cu), platinum (Pt), or an alloy thereof.

An insulating layer 31 may be formed on surfaces of the coil conductor patterns 42 and 44.

The insulating film may be formed by a known method such as a screen printing method, exposure of photo resist (PR), a process through development, a spray coating, a dipping process, and the like.

The insulating layer 32 is not particularly limited as long as it can be formed as a thin film. For example, the insulating layer 32 may include a photoresist (PR), an epoxy resin, or the like.

One end of the coil conductor pattern 42 formed on one surface of the insulating substrate 23 may be exposed to one end surface in the longitudinal direction of the magnetic body 50, and formed on an opposite surface of the insulating substrate 23. One end of the coil conductor pattern 44 may be exposed to the other end surface in the longitudinal direction of the magnetic body 50.

External electrodes 31 and 32 may be formed at both end surfaces of the magnetic body 50 so as to be connected to the coil conductor patterns 42 and 44 exposed to both end surfaces of the magnetic body 50 in the longitudinal direction.

The external electrodes 31 and 32 may extend in both end surfaces in the thickness direction and / or both end surfaces in the width direction of the magnetic body 50.

The external electrodes 31 and 32 may be formed of a metal having excellent electrical conductivity. For example, nickel (Ni), copper (Cu), tin (Sn), silver (Ag), or the like may be used alone or in combination thereof. Alloy and the like.

According to one embodiment of the present invention, when the angle formed by the tangent between the upper surface and the side surfaces of the coil conductor patterns 42 and 44 in the longitudinal cross section of the magnetic body 50 is 90.5 ° ≦ θ ≦ 103 Can satisfy °.

In addition, according to an embodiment of the present invention, the upper surfaces of the coil conductor patterns 42 and 44 may be flat.

That is, the upper surfaces of the coil conductor patterns 42 and 44 are planar, and the angle θ formed by the tangent between the upper surfaces and the side surfaces of the coil conductor patterns 42 and 44 is adjusted to satisfy 90.5 ° ≤ θ ≤ 103 °. As a result, since the coil conductor patterns 42 and 44 have a cross-sectional shape close to a quadrangle, the coil cross-sectional area is maximized compared to the existing coil structure, thereby minimizing the DC resistance Rdc.

When the angle θ formed by the tangent between the upper and side surfaces of the coil conductor patterns 42 and 44 is less than or equal to 90.5 °, the cross-sectional shape of the coil conductor patterns 42 and 44 is closer to a rectangle because the angle is closer to 90 °. It is possible to minimize the DC resistance (Rdc) by the maximum cross-sectional area of the coil, but it may be difficult to implement according to the variation in the lapping process as described later in the process of forming the coil conductor patterns (42, 44). .

On the other hand, when the angle θ formed by the tangent between the upper and side surfaces of the coil conductor patterns 42 and 44 exceeds 103 °, the upper surface of the coil conductor pattern is closer to the dome shape to reduce the coil cross-sectional area. There may be a problem of rising DC resistance (Rdc).

Meanwhile, the upper surfaces of the coil conductor patterns 42 and 44 are flat, and the angle θ formed by the tangent between the upper surfaces and the side surfaces of the coil conductor patterns 42 and 44 is adjusted to satisfy 90.5 ° ≤ θ ≤ 103 °. In the method, the coil conductor pattern is formed to the maximum in the height direction and then subjected to a lapping process, and a region of the upper portion of the coil conductor pattern is ground.

Through the above process, the coil conductor pattern has a planar top surface, and an angle θ formed by a tangent between the top surfaces and side surfaces of the coil conductor patterns 42 and 44 satisfies 90.5 ° ≤ θ ≤ 103 °. The thickness between the coil conductor patterns may be constantly adjusted.

In addition, the spacing between the coil conductor patterns can be constantly adjusted, so that the coil cross-sectional area is maximized to minimize the DC resistance (Rdc), and at the same time, short circuits can be improved, thereby improving reliability.

The process of forming the shape of the coil conductor pattern is just one embodiment, and the present invention is not limited thereto, and various methods may be applied.

According to one embodiment of the present invention, the aspect ratio (A / R) of the coil conductor patterns 42 and 44 may be 1.5 to 5.5.

In the chip electronic component according to an embodiment of the present invention, the coil conductor patterns 42 and 44 may advantageously increase the cross-sectional area of the coil in order to minimize the DC resistance (Rdc). Anisotropic plating method can be applied.

When the coil conductor pattern is grown in the thickness direction by applying the anisotropic plating method, the cross-sectional area of the coil is increased, thereby improving DC resistance (Rdc).

That is, according to one embodiment of the present invention, by adjusting the aspect ratio (A / R) of the coil conductor patterns 42 and 44 to satisfy 1.5 to 5.5, the cross-sectional area of the coil is increased to increase the DC resistance ( Rdc) has the effect of improving.

When the aspect ratio (A / R) of the coil conductor patterns 42 and 44 is less than 1.5, the aspect ratio (A / R) is close to 1, so that the cross-sectional area increase effect in a limited space As a result, the effect of improving the DC resistance (Rdc) may be insignificant.

On the other hand, when the aspect ratio (A / R) of the coil conductor patterns 42 and 44 exceeds 5.5, the DC resistance (Rdc) may be improved due to the increase in the cross-sectional area of the coil, but the plating growth may be uneven. Due to the short failure may occur, there may be a problem of the DC resistance (Rdc) degradation due to the ballistic plating that may occur due to the low copper (Cu) ion supply rate.

4 is an enlarged schematic view of another embodiment of part A;

Referring to FIG. 4, a chip electronic component according to another exemplary embodiment of the present disclosure may include a magnetic body including an insulating substrate 23 and coil conductor patterns 42 and 44 formed on at least one surface of the insulating substrate 23. 50; And external electrodes 31 and 32 formed at both ends of the magnetic body 50 so as to be connected to ends of the coil conductor patterns 42 and 44. The coil conductor patterns 42 and 44 are formed by plating, and c and an upper surface length b of the lower surface length of the coil conductor patterns 42 and 44 in the longitudinal section of the magnetic body 50 are included. In this case, 0.02 ≦ b / c ≦ 0.98 may be satisfied.

In addition, when the length of the center portion of the coil conductor patterns 42 and 44 is a, 0.02 ≦ b / a ≦ 0.98 may be satisfied.

According to another embodiment of the present invention, in the longitudinal cross section of the magnetic body 50, the lower surface length c, the upper surface length b, and the central portion length a of the coil conductor patterns 42 and 44 are 0.02. ≤ b / c ≤ 0.98 and 0.02 ≤ b / a ≤ 0.98, which is excellent because of the uniformity of the coil conductor patterns 42, 44, and the interval between the coils is constant, reducing the DC resistance (Rdc) It can be effective and at the same time reliable.

The ratio b / c of the lower surface length c and the upper surface length b of the coil conductor patterns 42 and 44 and the ratio b / a of the upper surface length b and the central portion length a are respectively 0.02. In the case of less than, since the variation | variation in each area | region of a coil conductor pattern is severe, there is no effect of reducing DC resistance Rdc.

The ratio (b / c) of the lower surface length (c) and the upper surface length (b) of the coil conductor patterns 42 and 44 and the ratio (b / a) of the upper surface length (b) and the central portion length (a) are 0.98, respectively. If it exceeds the ideal shape, it may be difficult to implement depending on the deviation in the working process.

An upper surface of the coil conductor pattern may be flat.

An aspect ratio (A / R) of the coil conductor pattern may be 1.5 to 5.5.

In addition, among the features of the chip electronic component according to another embodiment of the present invention, the same parts as those of the chip electronic component according to the embodiment of the present invention described above will be omitted here in order to avoid redundant description.

5 is a scanning electron microscope (SEM) photograph in which the coil conductor pattern portion of the chip electronic component according to the exemplary embodiment of the present invention is enlarged and observed.

Referring to FIG. 5, it can be seen that the shape of the cross section of the coil conductor pattern of the chip electronic component according to the exemplary embodiment of the present disclosure is almost square.

That is, according to one embodiment of the present invention, since the cross-sectional shape of the coil conductor pattern is almost square, it has a large area in the same space, so that the DC resistance (Rdc) improvement effect is excellent and the spacing between the coil conductor patterns is also constant. In addition, it can be seen that the reliability can be excellent according to the short defect reduction.

Hereinafter, a manufacturing process of a chip electronic component according to an embodiment of the present invention will be described.

First, the coil conductor pattern portions 42 and 44 may be formed on the insulating substrate 23.

The coil conductor patterns 42 and 44 can be formed on the thin insulating film 23 by electroplating or the like. In this case, the insulating substrate 23 is not particularly limited, and for example, a PCB substrate, a ferrite substrate, a metal-based soft magnetic substrate, or the like may be used, and may have a thickness of 40 to 100 μm.

The coil conductor patterns 42 and 44 may be formed by, for example, electroplating, but are not limited thereto. The coil conductor patterns 42 and 44 may be formed of a metal having excellent electrical conductivity. For example, silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), platinum (Pt) or alloys thereof Can be used.

A portion of the insulating substrate 23 may be formed with a hole and filled with a conductive material to form the via electrode 46. The via electrode 46 may be formed on a surface opposite to one surface of the insulating substrate 23. The coil conductor patterns 42 and 44 can be electrically connected.

A hole penetrating the insulating substrate 23 may be formed in the center portion of the insulating substrate 23 by performing a drill, a laser, a sand blast, a punching process, or the like.

The coil conductor patterns 42 and 44 are formed by isotropic plating on a pattern formed by a printing method, and anisotropic plating is performed by applying a high density current to grow in the thickness direction of the coil. Can be.

The upper surface of the coil may be planarized through a lapping process on the upper surfaces of the formed coil conductor patterns 42 and 44.

Next, an insulating film may be formed on the surfaces of the coil conductor pattern parts 42 and 44. The insulating film may be formed by screen printing, photo resist (PR) exposure, development, or spraying. It can be formed by a well-known method, such as a spray coating and a dipping process.

The insulating film is not particularly limited as long as it can form an insulating film of a thin film. For example, the insulating film may include a photoresist (PR), an epoxy resin, or the like.

The insulating film may be formed to have a thickness of 1 μm to 3 μm, and when the thickness of the insulating film is less than 1 μm, a leakage current may be generated due to damage to the insulating film, and a waveform defect or a short defect between coils may occur at high frequencies. If it exceeds 3㎛, capacity characteristics may be degraded.

Next, a magnetic body 50 may be formed by stacking magnetic layers on upper and lower portions of the insulating substrate 23 on which the coil conductor patterns 42 and 44 are formed.

The magnetic body layer can be formed by laminating the magnetic layer on both sides of the insulating substrate 23 and compressing it through a lamination method or a hydrostatic press method. In this case, the hole may be filled with a magnetic material to form a core part.

In addition, the external electrodes 31 and 32 may be formed to be connected to the coil conductor pattern parts 42 and 44 exposed on the end surface of the magnetic body 50.

The external electrodes 31 and 32 may be formed using a paste containing a metal having excellent electrical conductivity. For example, the external electrodes 31 and 32 may be formed of nickel (Ni), copper (Cu), tin (Sn), silver (Ag), or the like. It may be a conductive paste containing alone or alloys thereof. The external electrodes 31 and 32 may be formed by performing a dipping method as well as printing depending on the shape of the external electrodes 31 and 32.

Other parts that are the same as the features of the chip electronic component according to the embodiment of the present invention described above will be omitted here.

Boards for Chip Electronic Components

6 is a perspective view illustrating a board in which the chip electronic component of FIG. 1 is mounted on a printed circuit board.

Referring to FIG. 6, the mounting board 200 of the chip electronic component 100 according to the present embodiment may include a printed circuit board 210 mounted on the chip electronic component 100 and a printed circuit board 210. The first and second electrode pads 221 and 222 formed on the upper surface of the substrate are spaced apart from each other.

In this case, the chip electronic component 100 is a printed circuit by soldering 230 in a state in which the first and second external electrodes 31 and 32 are in contact with each other on the first and second electrode pads 221 and 222, respectively. It may be electrically connected to the substrate 210.

Except for the above description, the description overlapping with the features of the above-described chip electronic component according to the first embodiment of the present invention will be omitted here.

It is intended that the invention not be limited by the foregoing embodiments and the accompanying drawings, but rather by the claims appended hereto.

Accordingly, various forms of substitution, modification, and alteration may be made by those skilled in the art without departing from the technical spirit of the present invention described in the claims, which are also within the scope of the present invention. something to do.

100: thin film type inductor 23: insulated substrate
31, 32: external electrode 42, 44: coil conductor pattern
46: via electrode 50: magnetic body
200; A mounting substrate 210; Printed circuit board
221, 222; First and second electrode pads
230; Soldering

Claims

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A magnetic body including an insulating substrate and a coil conductor pattern formed on at least one surface of the insulating substrate; And
External electrodes formed at both ends of the magnetic body so as to be connected to ends of the coil conductor patterns;
Including;
The coil conductor pattern is formed by plating,
The coil conductor pattern is grown in the thickness direction of the coil through anisotropic plating from the base coil conductor pattern formed by isotropic plating,
In the longitudinal cross section of the magnetic body, when the bottom surface length of the coil conductor pattern is c, the top surface length is b, and the center portion length is a, 0.02 ≦ b / c ≦ 0.98 and 0.02 ≦ b / a ≦ 0.98 are satisfied.
The chip electronic component satisfying 90.5 ° ≤ θ ≤ 103 ° when the angle formed by the tangent between the upper surface and the side surface of the coil conductor pattern in the longitudinal cross section of the magnetic body is θ.

delete

The method of claim 5,
The upper surface of the coil conductor pattern is a chip electronic component, characterized in that the plane.

The method of claim 5,
Chip aspect, characterized in that the aspect ratio (A / R) of the coil conductor pattern is 1.5 to 5.5.

The method of claim 5,
The coil conductor pattern is any one selected from the group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). Chip electronics comprising one or more.

A printed circuit board having first and second electrode pads thereon; And
And the chip electronic component of claim 5 installed on the printed circuit board.