JP6121371B2 - Chip electronic component and its mounting board - Google Patents

Description

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

An inductor, which is one of the chip electronic components, is a typical passive device that forms an electronic circuit together with a resistor and a capacitor to remove noise, and is specified in combination with a capacitor using electromagnetic characteristics. It is used for the configuration of a resonance circuit and a filter circuit that amplifies a signal in a frequency band.

In recent years, downsizing and thinning of IT devices such as various communication devices and display devices have been accelerated, and various elements such as inductors, capacitors and transistors used in such IT devices have also been downsized and thinned. Research is underway to do this. Along with this, inductors are rapidly changing to small and high-density automatic surface mountable chips, and on the coil pattern formed by plating on the upper and lower surfaces of the thin insulating substrate. Thin film type chip inductors formed by mixing magnetic powder with resin have been developed.

This thin film type chip inductor is manufactured by forming a coil pattern on an insulating substrate and then filling the outside with a magnetic material.

In particular, in a coil, increasing the area of the coil to improve the direct current resistance (Rdc) characteristics greatly affects the efficiency of the thin film chip inductor.

Research is being conducted to improve the direct current resistance (Rdc) characteristics of thin film chip inductors by applying a method called anisotropic plating as a method for increasing the area of the coil.

The anisotropic plating method is a technique devised so that plating grows only above the coil due to high current density.

However, since plating is performed under a high current density, a plating burn phenomenon occurs at the end of the coil pattern due to insufficient supply of copper (Cu) ions due to speed, and the thickness deviation between the coil patterns is large. Therefore, there is a need for a way to remedy this problem.

Therefore, research for improving the plating burn phenomenon, plating thickness deviation and short circuit defect of the coil pattern is required, and research for improving the direct current resistance (Rdc) characteristics of the inductor is also required.

JP-A-11-204337

It is an object of the present invention to provide a chip electronic component and its mounting substrate.

In order to solve the above-described problem, according to an embodiment of the present invention, an insulating substrate, a magnetic body having a coil conductor pattern formed on at least one surface of the insulating substrate, an end portion of the coil conductor pattern, and External electrodes formed on both ends of the magnetic body so as to be connected, the coil conductor pattern comprising a pattern plating layer, an electrolytic plating layer formed on the pattern plating layer, and the electrolysis An anisotropic plating layer formed on the plating layer, and in the cross-section in the length-thickness direction of the magnetic body, the electrolytic plating layer has a lower side length adjacent to the insulating substrate on the upper side. A chip electronic component longer than the length of is provided.

The electrolytic plating layer may have a trapezoidal cross-sectional shape.

The upper surface of the electrolytic plating layer can be a flat surface.

The anisotropic plating layer can be formed on the insulating substrate.

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

The coil conductor pattern includes a group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). Any one or more selected can be contained.

According to another embodiment of the present invention, the printed circuit board includes a printed circuit board having first and second electrode pads on the upper part, and a chip electronic component provided on the printed circuit board. , An insulating substrate, and a magnetic body having a coil conductor pattern formed on at least one surface of the insulating substrate, and external portions formed at both ends of the magnetic body so as to be connected to ends of the coil conductor pattern The coil conductor pattern includes a pattern plating layer, an electrolytic plating layer formed on the pattern plating layer, and an anisotropic plating layer formed on the electrolytic plating layer, In the cross-section in the length-thickness direction of the magnetic body, the electrolytic plating layer is provided with a chip electronic component mounting substrate in which the length of the lower side adjacent to the insulating substrate is longer than the length of the upper side. .

The cross-sectional shape of the electrolytic plating layer can be a trapezoid.

The upper surface of the electrolytic plating layer can be a flat surface.

The anisotropic plating layer can be formed on the insulating substrate.

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

The coil conductor pattern includes a group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). Any one or more selected can be contained.

According to the chip electronic component according to one embodiment of the present invention, since the cross-sectional shape of the electrolytic plating layer in the coil conductor pattern is substantially trapezoidal, the occurrence of short-circuit defects is generated as compared with the cross-sectional shape of the conventional round electrolytic plating layer. Can be minimized.

Further, since the cross-sectional shape of the electrolytic plating layer is substantially trapezoidal, the anisotropic plating layer grows from the bottom of the electrolytic plating layer as compared with the cross-sectional shape of the conventional round electrolytic plating layer. The aspect ratio (Aspect) (A / R) of the pattern is improved, and the direct current resistance (Rdc) characteristic can be improved.

Further, according to the chip electronic component according to the embodiment of the present invention, the size of the coil conductor pattern can be reduced, so that anisotropic plating can be stably applied even to a small-sized chip.

1 is a schematic perspective view illustrating an internal coil pattern of a chip electronic component according to an embodiment of the present invention. It is sectional drawing along the II 'line of FIG. It is the schematic which expanded and showed one Embodiment of the A section of FIG. FIG. 2 is a perspective view illustrating a state in which the chip electronic component of FIG. 1 is mounted on a printed circuit board.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for a clearer description.

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

FIG. 1 is a schematic perspective view illustrating an internal coil pattern of a chip electronic component according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II ′ of FIG. FIG. 3 is an enlarged schematic view illustrating an embodiment of the A part of FIG.

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

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

The magnetic body 50 is an appearance of the thin film chip inductor 100 and is not particularly limited as long as it is a material having magnetic characteristics. For example, the magnetic body 50 is formed by being filled with ferrite or a metal-based soft magnetic material. be able to. As the ferrite, Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, Ba ferrite, Li ferrite, etc. are used. In this case, an Fe-Si-B-Cr-based amorphous metal powder material can be used, but is not limited thereto.

The magnetic body 50 may have a hexahedral shape. If the directions of hexahedrons are defined in order to clearly describe the embodiment of the present invention, L, W, and T displayed in FIG. 1 mean a length direction, a width direction, and a thickness direction, respectively. The magnetic body 50 may have a rectangular parallelepiped shape in which the length in the length direction is larger than the length in the width direction.

The insulating substrate 23 formed inside the magnetic body 50 is not particularly limited as long as it is formed in a thin film and can form the coil conductor patterns 42 and 44 by plating. For example, PCB A substrate, a ferrite substrate, a metal-based soft magnetic substrate, or the like can be used.

A hole is formed through the central portion of the insulating substrate 23, and the core can be formed by filling the hole with a magnetic material such as ferrite or a metal-based soft magnetic material. By forming the core portion filled with the magnetic material, inductance (Inductance; L) can be improved.

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

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 and the opposite surface of the insulating substrate 23 are formed on the insulating substrate 23. The via electrodes 46 can be electrically connected to each other.

The coil conductor patterns 42 and 44 and the via electrode 46 are formed to include 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 an alloy thereof can be used.

An insulating film can be formed on the surfaces of the coil conductor patterns 42 and 44.

The insulating film can be formed by a known method such as a screen printing method, an exposure and development process using a photoresist (PR), a spray coating, or a dipping process.

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

One end portion of the coil conductor pattern 42 formed on one surface of the insulating substrate 23 is exposed at one end surface of the magnetic body 50 in the length direction, and the coil conductor pattern 44 formed on the opposite surface of the insulating substrate 23. Can be exposed to the other end surface of the magnetic body 50 in the length direction.

External electrodes 31 and 32 are formed on both end surfaces in the length direction of the magnetic body 50 so as to be connected to the coil conductor patterns 42 and 44 exposed on both end surfaces in the length direction of the magnetic body 50. can do.

The external electrodes 31 and 32 can be formed to extend to both end faces in the thickness direction and / or both end faces in the width direction of the magnetic body 50.

The external electrodes 31 and 32 are formed to include a metal having excellent electrical conductivity. For example, nickel (Ni), copper (Cu), tin (Sn), or silver (Ag) alone or an alloy thereof. Etc. can be formed.

According to one embodiment of the present invention, the coil conductor patterns 42 and 44 include pattern plating layers 42a and 44a, electrolytic plating layers 42b and 44b formed on the pattern plating layers 42a and 44a, and the electrolytic plating layer. 42b, 44b and anisotropic plating layers 42c, 44c formed on the magnetic body 50. In the cross section in the length-thickness direction of the magnetic body 50, the electrolytic plating layers 42b, 44b The length of the lower side adjacent to is longer than the length of the upper side.

Research is being conducted to improve the direct current resistance (Rdc) characteristics of thin film chip inductors by applying a method called anisotropic plating as a method for increasing the area of the coil.

The anisotropic plating method is a technique devised so that plating grows only above the coil due to high current density.

However, since plating is performed under a high current density, the plating burn phenomenon occurs at the end of the coil conductor pattern due to insufficient supply of copper (Cu) ions due to speed, and the thickness deviation between the coil conductor patterns also increases. There was a problem that a short circuit defect occurred.

However, according to an embodiment of the present invention, the electrolytic plating layers 42b and 44b are characterized in that the length of the lower side adjacent to the insulating substrate 23 is longer than the length of the upper side. It is possible to solve a short circuit defect problem caused by a large thickness deviation.

That is, since the electrolytic plating layers 42b and 44b have a shape in which the length of the lower side adjacent to the insulating substrate 23 is longer than the length of the upper side, the anisotropic plating layers 42c and 44c are the outermost of the electrolytic plating layers 42b and 44b. Grows from the bottom. Thereby, since the thickness deviation between the coil conductor patterns 42 and 44 can be reduced, the occurrence of a short circuit between adjacent coil conductor patterns can be prevented.

Further, by reducing the thickness deviation between the coil conductor patterns 42 and 44, it is possible to prevent a short circuit from occurring between adjacent coil conductor patterns, so that the anisotropic plating layers 42c and 44c are grown higher. be able to. Thereby, the aspect ratio (Aspect Ratio; A / R) of the coil conductor pattern is improved, and the direct current resistance (Rdc) characteristics can be improved.

In addition, according to the chip electronic component according to the embodiment of the present invention, by reducing the size of the coil conductor patterns 42 and 44, it is possible to stably apply anisotropic plating to a small size chip.

The cross-sectional shape of the electrolytic plating layers 42b and 44b is not particularly limited, and may be a trapezoidal shape, for example.

Since the cross-sectional shape of the electrolytic plating layers 42b and 44b of the coil conductor patterns 42 and 44 is trapezoidal, the occurrence of short-circuit defects can be minimized as compared with the cross-sectional shape of a conventional round electrolytic plating layer. .

That is, since the cross-sectional shape of the electrolytic plating layers 42b and 44b is trapezoidal, the anisotropic plating layers 42c and 44c grow from the bottom of the electrolytic plating layer as compared with the cross-sectional shape of the conventional round electrolytic plating layer. This can be grown stably in the vertical direction.

Thereby, the thickness deviation of the said coil conductor patterns 42 and 44 reduces, and generation | occurrence | production of the short between adjacent coil conductor patterns can be prevented.

Further, since the anisotropic plating layers 42c and 44c are stably grown in the vertical direction, the aspect ratio (Aspect Ratio; A / R) of the coil conductor pattern is improved, and the direct current resistance (Rdc) characteristic is improved. it can.

The upper surfaces of the electrolytic plating layers 42b and 44b can be flat, but are not necessarily limited thereto.

Since the upper surfaces of the electrolytic plating layers 42b and 44b are flat, the anisotropic plating layers 42c and 44c are stabilized in the vertical direction from the lowermost portion of the electrolytic plating layer as compared with the cross-sectional shape of the conventional round electrolytic plating layer. Can grow.

As a result, the aspect ratio (A / R) of the coil conductor patterns 42 and 44 is improved, and the direct current resistance (Rdc) characteristics can be improved.

The anisotropic plated layers 42c and 44c can be formed on the insulating substrate 23.

As described above, since the anisotropic plating layers 42c and 44c are formed on the insulating substrate 23, that is, grown from the lowermost part of the electrolytic plating layer, the anisotropic plating layers 42c and 44c are formed vertically. Can grow stably in the direction.

Since the process of forming the shape of the coil conductor pattern is only one example, the present invention is not limited to this, and various methods can be applied.

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

In order to minimize the DC resistance (Rdc) by the coil conductor patterns 42 and 44 in the chip electronic component according to the embodiment of the present invention, it is advantageous to increase the cross-sectional area of the coil. Therefore, an anisotropic plating method for growing a coil in the thickness direction can be applied.

When a large number of coil conductor patterns are grown in the thickness direction by applying the anisotropic plating method, there is an effect that the cross-sectional area of the coil is increased and the direct current resistance (Rdc) characteristics are improved.

That is, according to an embodiment of the present invention, the coil cross-sectional area is adjusted by adjusting the aspect ratio (A / R) of the coil conductor patterns 42 and 44 to satisfy 1.5 to 5.5. Increases the DC resistance (Rdc) characteristics.

When the aspect ratio (Aspect Ratio; A / R) of the coil conductor patterns 42 and 44 is less than 1.5, the aspect ratio (Aspect Ratio; A / R) is close to 1. The effect of improving the DC resistance (Rdc) characteristic is small because the effect of increasing the cross-sectional area is small.

On the other hand, when the aspect ratio (A / R) of the coil conductor patterns 42 and 44 exceeds 5.5, the cross-sectional area of the coil increases and the DC resistance (Rdc) characteristics are improved. Although effective, short circuit failure may occur due to uneven growth of plating, and there may be a problem that direct current resistance (Rdc) characteristics deteriorate due to plating burn that may occur due to a low supply rate of copper (Cu) ions. .

According to an embodiment of the present invention, the coil conductor pattern includes silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), And any one or more selected from the group consisting of platinum (Pt) can be contained, but is not limited thereto.

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

First, the coil conductor patterns 42 and 44 can be formed on the insulating substrate 23.

The coil conductor patterns 42 and 44 can be formed on the thin insulating substrate 23 by electroplating or the like. At this time, 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 can be used. The insulating substrate 23 may have a thickness of 40 to 100 μm.

An example of a method for forming the coil conductor patterns 42 and 44 includes an electroplating method, but is not limited thereto. The coil conductor patterns 42 and 44 are formed to include a metal having excellent electrical conductivity. For example, silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), It can be formed of gold (Au), copper (Cu), platinum (Pt), or an alloy thereof.

The via electrode 46 can be formed by forming a hole in a part of the insulating substrate 23 and filling the hole with a conductive material. The coil conductor patterns 42 and 44 formed on one surface and the opposite surface of the insulating substrate 23 can be electrically connected to each other through the via electrode 46.

A hole penetrating the insulating substrate 23 can be formed in the central portion of the insulating substrate 23 by performing drilling, laser, sandblasting, punching, or the like.

The electrolytic plating layers 42b and 44b are formed by isotropic plating on the pattern plating layers 42a and 44a formed by the printing method, and anisotropic plating is performed by applying a high-density current to the thickness direction of the coil. Then, the anisotropic plating layers 42c and 44c are grown, whereby the coil conductor patterns 42 and 44 can be formed.

Since a normal electrolytic plating layer is formed by using isotropic plating, the upper surface has a round dome shape or a spherical shape.

However, according to an embodiment of the present invention, the electrolytic plating layers 42b and 44b are formed by isotropic plating, and the length of the lower side adjacent to the insulating substrate 23 is adjusted by adjusting the applied current. It can be manufactured in a trapezoidal shape longer than the length of.

Specifically, by increasing the density of the applied current, the length of the lower side adjacent to the insulating substrate 23 is long, and by reducing the density of the applied current toward the top, the shape of the upper side is short, that is, Trapezoidal electrolytic plating layers 42b and 44b can be implemented.

Next, anisotropic plating layers 42c and 44c can be formed by applying anisotropic plating on the electrolytic plating layers 42b and 44b. In this case, as described above, since the anisotropic plating layers 42c and 44c are formed on the insulating substrate 23, that is, grown from the bottom of the electrolytic plating layers 42b and 44b, the anisotropic plating is performed. The layers 42c and 44c can be stably grown in the vertical direction.

Next, an insulating film can be formed on the surfaces of the coil conductor patterns 42 and 44. As the method for forming the insulating film, a known method such as a screen printing method, an exposure and development process using a photoresist (PR), a spray coating, a dipping process, or the like can be used. .

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

The insulating film can be formed to a thickness of 1 μm to 3 μm. When the thickness of the insulating film is less than 1 μm, a leakage current due to the damage of the insulating film may occur, which may cause a waveform failure in which the inductance decreases at high frequencies or a short-circuit failure between the coils. In this case, the capacity characteristics can be deteriorated.

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

After laminating the magnetic layer on both surfaces of the insulating substrate 23, the magnetic body 50 can be formed by pressure bonding by a laminating method or an isostatic pressing method. At this time, the core portion can be formed by filling the hole with a magnetic material.

The external electrodes 31 and 32 connected to the coil conductor patterns 42 and 44 exposed on the end face of the magnetic body 50 can be formed.

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

In addition, description of the same parts as those of the chip electronic component according to the embodiment of the present invention is omitted.

Mounting board <br/> view of the chip electronic component 4 is a perspective view illustrating a state in which the chip electronic component of FIG 1 is mounted on the printed circuit board.

Referring to FIG. 4, the mounting substrate 200 of the chip electronic component 100 according to the present embodiment is formed on the upper surface of the printed circuit board 210 and the printed circuit board 210 on which the chip electronic component 100 is horizontally mounted. First and second electrode pads 221 and 222.

At this time, the chip electronic component 100 is printed on the printed circuit board by the solder 230 in a state where the first and second external electrodes 31 and 32 are disposed on the first and second electrode pads 221 and 222, respectively. 210 can be electrically connected.

Except for the above description, descriptions overlapping with the features of the chip electronic component according to the first embodiment of the present invention described above are omitted.

The embodiment of the present invention has been described in detail above, but the scope of the present invention is not limited to this, and various modifications and variations can be made without departing from the technical idea of the present invention described in the claims. It will be apparent to those having ordinary knowledge in the art.

DESCRIPTION OF SYMBOLS 100 Thin film type chip inductor 23 Insulating substrate 31, 32 External electrode 42, 44 Coil conductor pattern 42a, 44a Pattern plating layer 42b, 44b Electrolytic plating layer 42c, 44c Anisotropic plating layer 46 Via electrode 50 Magnetic body 200 Mounting substrate 210 Printed Circuit Boards 221, 222 First and Second Electrode Pads 230 Solder

Claims (8)

An insulating substrate and a magnetic body having a coil conductor pattern formed on at least one surface of the insulating substrate;
An external electrode formed on both ends of the magnetic body so as to be connected to an end of the coil conductor pattern,
The coil conductor pattern includes a pattern plating layer, an electrolytic plating layer formed so as to cover the pattern plating layer , and an anisotropic plating layer formed on the electrolytic plating layer, and the magnetic body main body In the cross section in the length-thickness direction, the electrolytic plating layer has a lower side length adjacent to the insulating substrate longer than the upper side length, and the anisotropic plating layer is formed from the insulating substrate. A chip electronic component. The chip electronic component according to claim 1, wherein the electrolytic plating layer has a trapezoidal cross-sectional shape. The chip electronic component according to claim 1, wherein an upper surface of the electrolytic plating layer is a flat surface. The coil conductor pattern includes a group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). The chip electronic component according to claim 1, comprising any one or more selected. A printed circuit board having first and second electrode pads on top;
Chip electronic components provided on the printed circuit board,
The chip electronic component includes an insulating substrate, a magnetic body having a coil conductor pattern formed on at least one surface of the insulating substrate, and both ends of the magnetic body so as to be connected to ends of the coil conductor pattern. The coil conductor pattern includes a pattern plating layer, an electrolytic plating layer formed to cover the pattern plating layer , and an anisotropy formed on the electrolytic plating layer. In the cross section in the length-thickness direction of the magnetic body, the electrolytic plating layer has a length of a lower side adjacent to the insulating substrate that is longer than a length of the upper side, and the anisotropic plating. A chip electronic component mounting substrate, wherein the layer is formed on the insulating substrate. 6. The chip electronic component mounting substrate according to claim 5 , wherein a cross-sectional shape of the electrolytic plating layer is a trapezoidal shape. 6. The chip electronic component mounting substrate according to claim 5 , wherein an upper surface of the electrolytic plating layer is a flat surface. The coil conductor pattern includes a group consisting of silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), and platinum (Pt). The chip electronic component mounting substrate according to claim 5 , comprising any one or more selected.

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