KR101532148B1 - Laminated Inductor - Google Patents

Abstract

The present invention relates to a ceramic body comprising a plurality of ceramic layers stacked; A plurality of conductor patterns formed in an arc shape having a gap in each of the ceramic layers; A plurality of via electrodes formed at regular intervals along one direction in which the conductor patterns are formed and forming coils by connecting the conductor patterns arranged up and down; First and second external electrodes formed on both end faces of the ceramic body and connected to both ends of the coil; The present invention provides a stacked inductor comprising:

Description

Laminated Inductor {Laminated Inductor}

The present invention relates to a stacked inductor.

An inductor is one of the important passive components of an electronic circuit together with a resistor and a capacitor, and can be used for a component removing noise or forming an LC resonance circuit.

Particularly, since the display screen is enlarged due to high performance of a mobile device such as a smart phone or a tablet PC, the speed of the APU increases, and the power consumption increases due to the use of a dual or quad core, which is used for a DC-DC converter The inductors are also required to have a high current tolerance.

In order to increase the current tolerance of such an inductor, it is important to lower the temperature rise by lowering the heating value of the inductor while suppressing the decrease of the L value by increasing the direct current superimposition characteristic of the material.

At this time, since the reduction of the DC resistance of the inductor has a great influence on the efficiency of the DC-DC converter and also acts to prevent the temperature rise, it is very important to lower the resistance of the coil in the inductor.

On the other hand, inductors can be classified into various types such as wound type, thin film type, and stacked type inductors according to the structure.

Among them, a wound or thin film type inductor can be manufactured by winding a coil on a ferrite core or printing and forming electrodes at both ends.

The multilayer inductor may be manufactured by printing a conductor pattern on a plurality of sheets of magnetic material, dielectric, or the like, and then laminating the conductor pattern along the thickness direction.

The multilayer inductor has advantages in that it can be downsized and reduced in thickness as compared with a wound type inductor, and is also advantageous in DC resistance, so that it can be widely used in a power supply circuit requiring miniaturization and high current.

Since the stacked inductors are required to have equivalent characteristics such as a large size while reducing the size of the product, various characteristics of the product such as the maximum L value, the DC resistance value, and the direct current superimposition characteristic are affected by the spatial limit of the inductor .

The following Patent Document 1 discloses a multilayer inductor having a coil including a conductor pattern and a via electrode formed on a ceramic layer.

Korean Patent Laid-Open Publication No. 2012-0031754

There is a need in the art for a new approach to a stacked inductor that can improve the shape of a conductor pattern and have excellent characteristics even in a small size.

According to an aspect of the present invention, there is provided a ceramic body comprising: a ceramic body having a plurality of ceramic layers stacked; A plurality of conductor patterns formed in an arc shape having a gap in each of the ceramic layers; A plurality of via electrodes formed at regular intervals along one direction in which the conductor patterns are formed and forming coils by connecting the conductor patterns arranged up and down; First and second external electrodes formed on both end faces of the ceramic body and connected to both ends of the coil; The present invention provides a stacked inductor comprising:

Another aspect of the present invention is a ceramic body comprising: a ceramic body having a plurality of ceramic layers stacked; A plurality of conductor patterns formed on each of the ceramic layers at 90% or more of an arc; A plurality of via electrodes formed at regular intervals along one direction in which the conductor patterns are formed and forming coils by connecting the conductor patterns arranged up and down; First and second external electrodes formed on both end faces of the ceramic body and connected to both ends of the coil; The present invention provides a stacked inductor comprising:

In one embodiment of the present invention, the via-electrode may be formed only in a portion adjacent to one side of the ceramic body in the conductor pattern.

In one embodiment of the present invention, the via-electrodes may be formed at regular intervals in a direction opposite to a direction in which the conductor patterns are wound in an arc.

In one embodiment of the present invention, the coil may be wholly wound in one of 3.5 turns, 4.5 turns and 5.5 turns.

In one embodiment of the present invention, the conductor pattern may include first and second connection patterns connected to the first and second external electrodes through both end faces of the ceramic body.

In an embodiment of the present invention, the upper and lower cover layers may be stacked on the upper and lower surfaces of the ceramic body.

According to the embodiment of the present invention, by forming the via electrodes at regular intervals along one direction of the conductor pattern, it is possible to realize a large number of coil turns while reducing the number of stacked conductor patterns, Inductance by reducing the height. The Q value can be improved and the Rdc can be lowered.

1 is a perspective view schematically showing the outline of a multilayer inductor according to an embodiment of the present invention.
2 is an exploded perspective view showing a structure in which a conductor pattern and via electrodes of a multilayer inductor according to an embodiment of the present invention are arranged.
3 is an exploded perspective view showing a structure in which conductor patterns and via electrodes of a multilayer inductor according to another embodiment of the present invention are arranged.
4 is an exploded perspective view showing a structure in which a conductor pattern and a via-electrode are arranged in a multilayer inductor according to another embodiment of the present invention.
5 is a schematic diagram for explaining a correlation between a coil and an inductance.

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 into 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 to more fully explain the present invention to those skilled in the art.

The shape and size of elements in the drawings may be exaggerated for clarity.

The same reference numerals are used for the same components in the same reference numerals in the drawings of the embodiments.

When the directions of the hexahedron are defined to clearly explain the embodiments of the present invention, L, W and T shown in Fig. 1 indicate the longitudinal direction, the width direction and the thickness direction, respectively. Here, the thickness direction can be used in the same concept as the lamination direction in which the ceramic layers are laminated.

In the present embodiment, for convenience of explanation, the surfaces on which the first and second external electrodes are formed in the longitudinal direction of the ceramic body are set to both end surfaces, the surfaces perpendicular to each other are set to both sides, Will be described together with the upper and lower surfaces in the thickness direction.

FIG. 1 is a perspective view schematically showing an outline of a multilayer inductor according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing a structure in which a conductor pattern and via electrodes of a multilayer inductor according to an embodiment of the present invention are arranged .

1 and 2, a multilayer inductor 100 according to an embodiment of the present invention includes a ceramic body 110, a plurality of conductor patterns 211-216, and a plurality of via electrodes 221-225 First and second external electrodes 131 and 132, respectively.

The upper and lower cover layers 111 and 112 may be formed on the upper and lower surfaces of the ceramic body 110 to protect the plurality of conductor patterns 211 to 216 printed inside the ceramic body 110 .

The upper and lower cover layers 111 and 112 may be formed by laminating a single or a plurality of ceramic layers formed of a ceramic sheet in the thickness direction.

The ceramic body 110 is formed by laminating a plurality of ceramic layers 113 formed of a ceramic sheet in the thickness direction and then firing the ceramic body 110. The shape and dimensions of the ceramic body 110 and the number of layers of the ceramic layer 113 The present invention is not limited thereto.

The conductor patterns 211 to 216 are formed by printing a conductive paste containing a conductive metal to a predetermined thickness on each of the ceramic layers 113.

For example, the conductor patterns 211-216 may be made of a material containing silver (Ag) or copper (Cu), or an alloy thereof, but the present invention is not limited thereto.

The conductor patterns 211-216 may be formed to be close to the arc shape. That is, each of the conductor patterns 211-216 may be formed in an arc shape having one gap.

At this time, the inner core portion of the coil may be formed of a metal magnetic material or a ferrite material, but the present invention is not limited thereto.

In other respects, the conductor patterns 211 to 216 may be formed in the entire region excluding a part of the arc. At this time, the conductor pattern 211-216 may preferably be formed at 90% or more of the arc.

The number of turns of the coil realized by stacking one conductor pattern is less than one turn, and in this embodiment, the number of stacked conductor patterns is +0.5 of the number of coil turns. When the total number of stacked layers of the ceramic layers 113 on which the conductor patterns 211-216 are formed in the multilayer inductor 100 is increased, the difference between the number of stacked conductor patterns and the number of coil turns is accumulated, There may be a limit stack number of +1.5 of the number of turns. If the coil consists of conductor patterns formed with less than 90% of the arc, this limit stacking number can be determined to be a lower number.

The total number of stacked layers of the ceramic layers 113 on which the conductor patterns 211-216 are formed can be variously determined in consideration of the electrical characteristics such as the inductance value required by the designed stacked inductor 100.

In the present embodiment, the coils have a 5.5 turn structure as a whole, and the conductor patterns 211 to 216 are stacked in six layers. This 5.5 turn coil structure is, for example, the maximum number of coil turns possible in the 2012 size. When the size of the ceramic body is larger than 3216, the length of the rectangular ceramic layer becomes longer, and thus two ceramic layers 113 on which the conductor patterns 211-216 are formed can be laminated to a maximum of 7.5 turn coil structures .

In addition, the maximum number of turns of the coil can be changed by controlling the line width and the process precision of the conductor pattern even in the stacked inductor of the same size.

At least two of the conductor patterns may be first and second connection patterns 211 and 212 having lead portions drawn out through both end faces of the ceramic body 110, respectively.

The lead portions are in contact with and electrically connected to the first and second external electrodes 131 and 132 formed on both end faces of the ceramic body 110.

In the present embodiment, the first and second connection patterns are disposed at the upper and lower ends of the ceramic body, but the present invention is not limited thereto.

The via-electrodes 221-225 connect the conductor patterns 211-216 arranged up and down to form a coil.

The via electrodes 221-225 shown in FIG. 2 are formed at predetermined intervals at the ends of the conductor patterns 211-216 in order to secure a minimum margin for preventing a process failure.

The via electrodes 221 to 225 can be formed by forming through holes (not shown) in the respective ceramic layers 113, and then filling the through holes with a conductive paste having excellent electrical conductivity.

The conductive paste may include at least one of silver (Ag), silver-palladium (Ag-Pd), nickel (Ni), and copper (Cu) It is not.

The first and second external electrodes 131 and 132 are formed on both end faces of the ceramic body 110 and are connected to both ends of the coil, And are electrically connected to each other.

The first and second external electrodes 131 and 132 may be made of a conductive metal material having excellent electrical conductivity.

For example, the first and second external electrodes 131 and 132 may be made of a material containing at least one of silver (Ag) and copper (Cu), or an alloy thereof, but the present invention is not limited thereto.

On the outer surfaces of the first and second external electrodes 131 and 132, a nickel (Ni) layer (not shown) and a tin (Sn) layer (not shown) .

According to the present embodiment, the conductor patterns 211 to 216 arranged vertically form one helical coil connected to each other by the via-electrodes 221 to 225 and connected as a whole. At this time, the coil may be formed in a structure in which the coil is wound in a total of 5.5 turns.

In the present embodiment, the via-electrodes 221-225 may be formed only in the portion of the conductor pattern 211-216 adjacent to one side of the ceramic body 110. [

In this embodiment, the via electrodes 221-225 may be formed at regular intervals in the direction opposite to the direction in which the conductor patterns 211-216 are wound in a circular arc.

In general, the capacity of an inductor is determined by both material and structural aspects.

The inductance is proportional to the magnetic permeability of the material, the winding of the coil is proportional to the square of the number of turns, and the path of the magnetic flux of the inductor is the length The shorter the area is, the larger the area through which the magnetic flux passes.

[Formula 1]

Where N is the number of turns of the coil, A is the cross-sectional area of the core, l is the length of the coil, _r is the relative permeability of the internal material, and ₀ is the permeability of the vacuum.

The conventional multilayer inductors are largely classified into a method of manufacturing a ceramic sheet, printing on the ceramic sheet, laminating sheets, and a method of printing both the conductor pattern and the ceramic body.

However, since the conductor is actually wound on the ceramic sheet and the interlayer is connected to the via electrode instead of winding the conductor, a turn of the coil can not be completely realized in one layer of the sheet in the manufacturing method. The number of stacked patterns increases.

For example, in order to form a coil having a three-turn structure, six sheets are required for a half-circular pattern, and five sheets for a three-quarter circular pattern.

In order to reduce the number of stacked conductor patterns, there is a 1/1 pattern formed as close as possible to the arc shape. In this case, the number of stacked layers can be reduced by implementing one turn per sheet by deforming the conductor pattern . For example, to make three turns, you need four stacks.

Therefore, to realize the same number of turns, the 1/1 pattern has the smallest number of layers, the next 3/4 pattern, and the largest number of layers.

As the number of laminated conductor patterns increases, l increases in the above formula (1), and the area of the space on the electrode where the magnetic flux returns is reduced, so that the capacity is reduced.

However, since the coil having the 1/1 pattern structure has a structure that damages the coil magnetic flux area, the relative area decrease is not often used because the size of the chip increases as the size of the chip becomes smaller.

The stacked inductor of the present embodiment can realize the same number of coil turns with a lower number of stacked layers compared to the conventional stacked inductors so that the capacity can be increased in a small size.

For example, if five conductor patterns are stacked to form a desired coil structure, a reduction of only one conductor pattern by 20% is achieved, which is a value that can affect the capacity by more than 10% .

In the present embodiment, it is possible to realize a larger capacitance because the inner area of the coil is larger than the 1/1 pattern in which the conductor pattern is formed at 95% or more of the arc, based on the same number of conductor pattern stacks.

As the inductance increases in the number of coil turns, the Q value can be increased in proportion, which can be advantageous in a high frequency inductor requiring a high Q value. Also, under certain conditions, the number of turns of the coil due to the rise of the inductance is reduced, so that Rdc can be reduced.

For example, when the line width of the conductor pattern is widened to reduce the passage area of the magnetic flux, or when the electrode is made thick, the length of the path is advantageous in the number of layers. Improvement will be possible.

When the printing width of the conductor pattern is small or the resolution is important as in the case of double printing, a shot due to the bleeding occurs frequently between adjacent conductor patterns in the formation of the 1/1 pattern. According to this embodiment, It is possible to reduce the shot problem because the facing area is small.

On the other hand, conventionally, the larger the number of laminated conductor patterns, the greater the number of screens used. In the case of this embodiment, since some of the conductor patterns are vertically symmetrical when screen printing the conductor pattern, The number of screens can be reduced to three and the productivity can be improved by reducing the number of screens when the conductor pattern is printed.

FIG. 3 is an exploded perspective view showing a structure in which a conductor pattern and via electrodes of a multilayer inductor according to another embodiment of the present invention are disposed, FIG. 4 is a cross-sectional view of a multilayer inductor according to another embodiment of the present invention, Fig.

Referring to FIG. 3, the coil of the stacked inductor includes four conductor patterns 2110-2140 and three via electrodes 2210-2230. At this time, the positions of the upper and lower via-electrodes 2210-2230 may be shifted at a wider interval than the stacked inductor shown in FIG. At this time, the coil has a structure that is wound around 3.5 turns as a whole.

Other details are the same as those of the embodiment described above, so a detailed description thereof will be omitted in order to avoid duplication.

Referring to Fig. 4, the coil of the stacked inductor includes five conductor patterns 2310-2350 and four via electrodes 2410-2440. At this time, the positions of the upper and lower via electrodes 2410-2440 are shifted at a wider interval than the stacked inductor having the coil of the 5.5 turn structure shown in FIG. 2, and the coil of the 3.5 turn structure shown in FIG. 3 It can be formed by moving at narrow intervals compared to the stacked inductor. At this time, the coil has a structure in which it is wound with 4.5 turns as a whole.

Other details are the same as those of the embodiment described above, so a detailed description thereof will be omitted in order to avoid duplication.

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

It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

100; A stacked inductor 110; Ceramic body
111, 112; Upper and lower cover layers 113; Ceramic layer
131, 132; The first and second outer electrodes
211, 212; The first and second connection patterns
213-216; Conductor pattern
221-225; Via electrode

Claims (16)

delete delete delete delete delete delete delete delete A ceramic body in which a plurality of ceramic layers are stacked;
A plurality of conductor patterns formed in an arc shape having a gap in each of the ceramic layers and formed of 90% or more of a circular arc;
A plurality of via-electrodes formed at regular intervals in a direction opposite to a direction in which the conductor patterns are wound in an arc, and connecting the conductor patterns arranged up and down to form coils; And
First and second external electrodes formed on both end faces of the ceramic body and connected to both ends of the coil; / RTI >
Wherein the plurality of conductor patterns are located at a portion of the conductor pattern adjacent to one side of the ceramic body,
Wherein a distance between each of the via-electrodes and one side of the ceramic body is the same,
Wherein the number of layers of the conductor pattern is +0.5 of the number of turns of the coil.
delete delete 10. The method of claim 9,
Wherein the coil has a structure in which the coil is wound in a total of 3.5 turns.
10. The method of claim 9,
Wherein the coil is a structure having a total turn of 4.5 turns.
10. The method of claim 9,
Wherein the coil has a structure in which the coil is wound in a total of 5.5 turns.
10. The method of claim 9,
Wherein the conductor pattern includes first and second connection patterns connected to the first and second external electrodes via both end faces of the ceramic body.
10. The method of claim 9,
And upper and lower cover layers stacked on upper and lower surfaces of the ceramic body.

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