JP6429951B2 - Coil component and manufacturing method thereof - Google Patents

Description

  The present invention relates to a coil component and a manufacturing method thereof.

  As digital devices such as smartphones become more sophisticated, electronic product circuits are becoming more complex, and the importance of countermeasures against noise generated in the circuits is increasing.

  As such a laminated coil component, a chip inductor or a chip bead can be used by simply connecting it in series with a circuit. Therefore, it is frequently used among the above-mentioned noise countermeasure elements, and the market demand will be increased. Further increase is expected.

  The chip inductor or chip bead is made of a magnetic material such as ferrite. The magnetic material is magnetically saturated by applying an electric current, and the magnetic saturation characteristics are greatly affected by the initial magnetic permeability of the magnetic material.

  In a laminated coil component, in order to achieve high Z and Ls values using a coil with a small number of turns, it is advantageous that the magnetic material has a relatively high permeability. However, in this case, since the magnetic saturation is fast, there is a problem in realizing the DC bias characteristics.

  On the other hand, when the permeability of the magnetic material is lowered, the magnetic saturation is delayed, but the resonance frequency itself becomes high, and the Z value of the coil component in the low frequency band of 100 MHz or less becomes relatively low.

  For this reason, the use frequency of the coil component is limited, and the number of turns of the coil has to be increased in order to realize the target Z and Ls values of the coil component, so that the size of the coil component can be relatively large.

JP 2013-201374 A

  An object of the present invention is to provide a coil component that realizes Z and Ls values higher than the number of turns of the coil, can remove noise over a wide band, and has excellent DC bias characteristics, and a method for manufacturing the same. .

  One aspect of the present invention includes a magnetic body and a coil, and first and second surfaces facing each other, and third and fourth surfaces and first and second surfaces facing each other connected to the first and second surfaces. A main body that has fifth and sixth surfaces that are coupled to the third and fourth surfaces and face each other, and that both ends of the coil are exposed through at least the third and fourth surfaces, respectively. Coil components including first and second external electrodes respectively disposed on the third and fourth surfaces of the main body and connected to both exposed ends of the coil, wherein the coils are respectively magnetic layers. A plurality of conductor patterns formed in a strip shape having a gap above, and via electrodes that are formed at regular intervals along one direction in which the conductor patterns are formed, and connect the conductor patterns arranged vertically. The body is surrounded by a coil A first magnetic body portion inside the coil and a second magnetic body portion outside the coil, wherein the second magnetic body portion has a lower magnetic permeability than the first magnetic body constituting the first magnetic body portion. The coil component which consists of a 2nd magnetic body which has these is provided.

  Another aspect of the present invention includes a step of forming a laminated body including a coil by a build-up method, a step of firing the laminated body to form a main body, and the main body connected to both exposed ends of the coil. Forming the first and second external electrodes as described above, wherein the laminated body prints a material containing the first magnetic body to form the first magnetic body portion. Forming a conductive pattern by printing a conductive paste so as to surround an edge of the first magnetic body portion; forming a via electrode in the conductive pattern; and the first magnetic body By repeating the step of printing the material containing the second magnetic body on the edge of the portion so as to cover the conductor pattern to form the second magnetic body portion, so that the via electrode of the adjacent conductor pattern is contacted Let the coil be constructed, carp To provide a process for the production of parts.

  According to an embodiment of the present invention, by applying different materials having different magnetic permeability to the main body of the multilayer coil component, it is possible to realize Z and Ls values higher than the number of turns, and to reduce noise over a wide band. It can be removed, and it can be expected that the DC bias characteristics can be relatively improved.

1 is a perspective view schematically showing a part of an inductor in accordance with an embodiment of the present invention. FIG. 2 is an exploded perspective view showing a laminated structure of a magnetic layer and a conductor pattern in the inductor of FIG. 1. It is sectional drawing of the II 'line of FIG. 5 is a graph showing saturation magnetic flux density according to the magnetic permeability of the main body in an inductor whose main body is made of a single magnetic material. 5 is a graph showing inductance according to the magnetic permeability of the main body in an inductor whose main body is made of a single magnetic material. 5 is a graph showing a comparison between frequency and impedance of a conventional inductor and an inductor according to an embodiment of the present invention. It is the figure which showed the formation process of the 1st magnetic body part by one Embodiment of this invention in order. It is the figure which showed the formation process of the conductor pattern by one Embodiment of this invention in order. It is the figure which showed the formation process of the 2nd magnetic body part by one Embodiment of this invention in order.

  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 enlarged or reduced (or highlighted or simplified) for a clearer description.

Coil component Hereinafter, a multilayer inductor will be described as an example of the multilayer coil component. However, the present invention is not limited to this, and the laminated coil component may be, for example, laminated beads.

  FIG. 1 is a perspective view schematically showing a part of an inductor according to an embodiment of the present invention, and FIG. 2 shows a laminated structure of a magnetic layer and a conductor pattern in the inductor of FIG. FIG. 3 is a sectional view taken along the line II ′ of FIG.

  Referring to FIGS. 1 to 3, an inductor 100 according to an embodiment of the present invention includes a main body 110 and first and second external electrodes 131 and 132.

  The main body 110 includes a magnetic body and a coil 120.

  At this time, the shape of the main body 110 is not particularly limited, but may be substantially hexahedral.

  For convenience of explanation, both surfaces of the main body 110 facing each other in the Z direction are set as first and second surfaces 1 and 2, facing each other in the X direction, and the tips of the first and second surfaces 1 and 2. Are connected to each other in the Y direction, and the ends of the first and second surfaces 1 and 2 are connected to each other, and the third and fourth surfaces 3, 4 are connected to each other. Both surfaces connecting the tips of the first and second surfaces are set as the fifth and sixth surfaces 5 and 6.

  The main body 110 of the present embodiment includes a first magnetic body portion A1 located inside the coil 120 and a second magnetic body portion A2 located outside the coil 120 with the coil 120 as a reference.

  The first magnetic body part A1 is composed of a high magnetic permeability first magnetic body having a higher magnetic permeability than the second magnetic body part A2, and the second magnetic body part A2 is relatively relative to the first magnetic body. And a low magnetic permeability second magnetic body having a low magnetic permeability.

  The first magnetic part A1 is a part that has a great influence on the Z characteristic and the Ls characteristic of the inductor 100 in terms of its position. Since the first magnetic substance having a high magnetic permeability is applied, the first magnetic part A1 has a small number of turns. Even if 120 is configured, it is advantageous in realizing the targets Z and Ls of the inductor 100.

  In addition, since the first magnetic body of the first magnetic body portion A1 has a high magnetic permeability, the first magnetic body has a broad (impedance) characteristic. Therefore, it is very effective in removing broadband noise.

  The second magnetic body portion A2 is the entire area of the main body 110 excluding the first magnetic body portion A1. Specifically, the second magnetic body portion A2 is an interface between the conductor patterns 121 to 125 constituting the coil 120 and an outer portion of the coil 120. Can be.

  Since the outer portion of the coil 120 including the printed surface of the coil 120 is a region where magnetic saturation is concentrated when a current is applied, the lower portion of the second magnetic body portion A2 is reduced as in the present embodiment. When the second magnetic body having magnetic permeability is applied, the DC bias characteristic of the inductor 100 can be improved.

  In addition, the main body 110 of the present embodiment may further include upper and lower covers 112, 112 ′, 113, 113 ′ that are formed outside the upper and lower portions in the Z direction.

  The upper and lower covers 112, 112 ′, 113, 113 ′ are made of the same material as that of the magnetic layer 111, and the coil 120 is completely embedded except for the lead-out portion. It is possible to prevent the electrical characteristics from deteriorating.

  Therefore, according to the present embodiment, the first magnetic body portion A1 is located inside the main body 110 and is not exposed to the outside at all.

  At this time, the first magnetic body portion A1 serving as a center core (Core) of the product is formed so as to protrude above the outermost side of the coil 120 in the Z direction, which is the stacking direction of the conductor patterns 121 to 125. be able to. In this case, a relatively high impedance (Impedance) can be realized as compared with the case where the coil 120 is formed horizontally, and various and variable by adjusting the height of the first magnetic body portion A1 in the Z direction. Impedance characteristics can be realized.

  Further, the first magnetic body portion A1 that plays the role of the central core is not penetrating, and a structure in which the outermost side is covered with the second magnetic body of the main body 110 can be applied. In this case, by surrounding the surface of the inductor 100 with the second magnetic material of the main body 110, it is possible to improve appearance defects such as firing mismatch due to the use of different materials.

  In addition, since the first magnetic body portion A1 is made of a material having a high magnetic permeability, the first magnetic body portion A1 usually exhibits characteristics slightly inferior in plating bleeding and moisture resistance reliability. This problem can be compensated by enclosing it with.

  The coil 120 of the present embodiment includes a plurality of conductor patterns 121 to 125 stacked in the Z direction and a plurality of via electrodes 161 and 162 that connect the adjacent conductor patterns 121 to 125 to each other.

  The conductive patterns 121 to 125 are printed on each magnetic layer 111 with a conductive paste containing a conductive metal to a predetermined thickness by a method such as screen printing, or by a method such as electroplating. The method can be used.

  The conductive metal can be made of a conductive metal such as silver (Ag), copper (Cu), nickel (Ni), or an alloy thereof.

  In addition, the conductor patterns 121 to 125 can be formed in a strip shape having a gap.

  At this time, in order to maximize the capacitance, the conductor patterns 121 to 125 can be formed in a loop shape as much as possible along the periphery of the magnetic layer 111.

  In addition, the conductor patterns 121 to 125 preferably have a substantially spiral structure, but the present invention is not limited to this, and a polygon such as a quadrangle, a pentagon, a hexagon, It may be circular, elliptical, etc., or may be formed in an irregular shape.

  Of the conductor patterns, part of the conductor patterns 121 and 122 arranged at the uppermost end and the lowermost end in the Z direction can be exposed through the third and fourth surfaces 3 and 4 of the main body 110, respectively. .

  For this purpose, first and second lead portions 121a and 122a are formed at both ends of the conductor patterns 121 and 122 so as to be exposed through the third and fourth surfaces 3 and 4 of the main body 110, respectively. be able to.

  In the via electrodes 161 and 162 of the present embodiment, vias as through holes are formed in the respective magnetic layers 111 on which the conductor patterns 121 to 125 are formed, and then the vias are filled with a conductive paste having excellent conductivity. By doing so, it can be formed.

  The via electrodes 161 and 162 connect adjacent conductor patterns 121 to 125 to each other in the Z direction, and can be formed at regular intervals along one direction in which the conductor patterns 121 to 125 are formed.

  The conductive paste may be made of, for example, at least one of silver (Ag), silver-palladium (Ag-Pd), nickel (Ni), and copper (Cu), or an alloy thereof. It is not limited to this.

  The first and second external electrodes 131 and 132 are disposed on the third and fourth surfaces 3 and 4 of the main body 110, respectively.

  The first and second external electrodes 131 and 132 are connected to the first and second lead portions 121a and 122a of the coil exposed through the third and fourth surfaces 3 and 4 of the main body 110, respectively.

  The first and second external electrodes 131 and 132 include first and second connection portions 131a and 132a formed on the third and fourth surfaces 3 and 4 of the main body 110, and the first and second connection portions 131a. , 132a, and first and second band portions 131b, 132b extending from the first, second, fifth, and sixth surfaces 1, 2, 5, 6 of the main body 110.

  In this case, the fixing strength of the first and second external electrodes 131 and 132 can be improved, and the first surface 1 or the second surface 2 of the main body 110 can be a mounting surface.

  The first and second external electrodes 131 and 132 may be made of a conductive metal material having excellent 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) or copper (Cu) or an alloy thereof, but the present invention is not limited thereto. is not.

  A plating layer may be formed on the outer surfaces of the first and second external electrodes 131 and 132 as necessary.

  The plating layer may be formed by sequentially forming a nickel (Ni) layer and a tin (Sn) layer from the inside.

  In the conventional multilayer coil component, the main body is made of a single magnetic material.

  At this time, the electrical characteristics of the coil component are determined by the initial permeability and magnetic characteristics of the magnetic material.

  FIG. 4 is a graph showing the saturation magnetic flux density according to the magnetic permeability of the main body in an inductor made of a single magnetic material, and FIG. 5 is a graph showing the saturation magnetic flux density of the main body made of a single magnetic material. It is the graph which showed the inductance by the magnitude | size of the magnetic permeability of a main body.

  4 and 5, the magnitudes of the magnetic permeability of samples C, D, and E are in the order of C> D> E. 4 and 5, I is a current, an intermediate reference line is 8 mA, B in FIG. 4 is a magnetic flux density, and L in FIG. 5 is an inductance.

  4 and 5, when the magnetic material of the main body has a relatively high magnetic permeability, high Z and Ls can be realized even if the coil is configured with a small number of turns. It can be seen that there is a limit in realizing the DC bias characteristics because of the fastness.

  On the other hand, when the magnetic material of the main body has a relatively low magnetic permeability, there is an effect that the magnetic saturation is delayed, but the resonance frequency itself becomes high, and Z and Ls in a low frequency band of 100 Mhz or less are reduced. There is a limit to the operating frequency due to a sudden drop. For this reason, it is not possible to sufficiently fulfill the role of removing noise, and the number of turns of the coil must be increased in order to realize the target Z and Ls of the inductor, so that the size of the inductor increases.

  According to the present embodiment, in the main body 110, the first magnetic body portion A <b> 1 located on the inner side with respect to the coil 120 is composed of the first magnetic body having a relatively high magnetic permeability and is located on the outer side of the coil 120. The body part A2 is made of a second magnetic body having a relatively low magnetic permeability.

  The first magnetic body part A1 is a part that greatly affects the values of Z and Ls. By realizing higher Z and Ls by the first magnetic body, the coil can be relatively compared with the conventional inductor of the same size. It can be configured with a small number of turns.

  Therefore, the size of the inductor 100 can be reduced, and the number of turns of the coil 120 can be increased to realize a high capacity with the same size as the conventional inductor.

  At this time, since the first magnetic part A1 is not a part where magnetic flux is concentrated, magnetic saturation is not greatly accelerated. Therefore, it is possible to prevent the DC bias characteristics of the inductor from being deteriorated.

  The second magnetic part A2 is an interlayer part and an outer part of the coil 120 where the magnetic flux is concentrated, and the magnetic saturation of the inductor can be reduced by using the low magnetic permeability second magnetic substance.

  However, since the second magnetic body portion A2 is a portion having little influence on the Z and Ls values, the total Z and Ls of the coil parts are greatly reduced even if the permeability of the second magnetic body is relatively low. Can be prevented.

  Therefore, according to the present embodiment, relatively high Z and Ls can be realized as compared with the small number of turns of the coil, and thereby noise can be removed over a wide band and the DC bias characteristic of the coil component can be achieved. Can be improved.

  FIG. 6 is a graph showing a comparison of the frequency and impedance of a conventional inductor and an inductor according to an embodiment of the present invention.

  In this case, in the comparative example and the example, the size of the inductor is 1.0 × 0.5 × 0.5 (mm), and the coil is formed by stacking a total of five conductive patterns.

  Further, in the comparative example, the main body is composed only of the second magnetic body, and in the embodiment, the main body is divided into the first and second magnetic bodies. Here, the magnetic permeability of the first magnetic body is 200 or more, and the magnetic permeability of the second magnetic body is 5 to 100.

  Referring to FIG. 6, it can be seen that in the inductor of the example of the present invention, the Z characteristic and the Ls characteristic are greatly improved as compared with the comparative example, and the Z in the low frequency band of 100 Mhz or less is high.

  Therefore, noise can be removed over a wide band, and the coil can be configured with a relatively small number of turns in order to realize the target Z and Ls values of the inductor with the same size, thereby improving the inductance of the inductor. Can do.

Manufacturing method of coil component In the manufacturing process of the existing multilayer coil component, it is not easy to realize the main body made of different materials in the present embodiment.

  In this embodiment, when manufacturing a coil component, a laminated coil component including a main body made of a different material can be manufactured using a build-up method.

  The build-up method is a method of forming vias and conductor patterns for each layer using a laser drill or the like and laminating them in the Z direction.

  In order to manufacture the coil component of the present embodiment, as shown in FIGS. 7A and 7B, first, a material containing the first magnetic body is made into a paste, and is formed at the center of the base 210. By printing, the first magnetic body region P1 is formed.

  Next, as shown in FIGS. 8A and 8B, a conductive material containing a conductive metal such as silver (Ag) so as to surround an outer edge (Edge) of the first magnetic region P1. The conductor pattern C is formed by printing the paste.

  Thereafter, a step of forming a via electrode in the conductor pattern C can be further performed.

  Next, as shown in FIGS. 9A and 9B, the material containing the second magnetic material is made into a paste and printed so as to cover the conductor pattern C on the edge of the first magnetic material region P1. The two magnetic region P2 is formed.

  A laminated body is formed by repeating the above steps so that a plurality of conductor patterns C adjacent in the Z direction are connected to corresponding via electrodes.

  At this time, at least one of the conductor patterns is formed with first and second lead portions that are drawn through the second magnetic body portion.

  Further, a cover can be further formed on the upper surface or the lower surface of the laminate, and in this case, the cover can be formed of a material including the second magnetic body.

  Next, the laminate is fired to form a main body.

  In this case, in the main body, the plurality of first magnetic body regions stacked in the upper and lower directions becomes the first magnetic body portion, and the plurality of second magnetic body regions stacked in the upper and lower directions becomes the second magnetic body portion, The conductor pattern and the conductive via form one coil.

  Next, first and second external electrodes may be formed on the third and fourth surfaces of the main body so as to be connected to the first and second lead portions exposed to the outside, respectively.

  The first and second external electrodes of the present embodiment can be formed using a material excellent in electrical conductivity. For example, a conductive material such as silver (Ag) or copper (Cu) or an alloy thereof is used. However, the present invention is not limited to this.

  At this time, the first and second external electrodes can be formed by a normal method, for example, can be formed by one of methods such as thick film printing, coating, vapor deposition, and sputtering, The present invention is not limited to this.

  In addition, a plating layer can be further formed on the surfaces of the first and second external electrodes formed in this manner by plating nickel (Ni) or tin (Sn) as necessary. .

  As mentioned above, although embodiment of this invention was described in detail, the scope of the present invention is not limited to this, and various correction and deformation | transformation are within the range which does not deviate from the technical idea of this invention described in the claim. It will be apparent to those having ordinary knowledge in the art.

DESCRIPTION OF SYMBOLS 100 Inductor 110 Main body 111 Magnetic body layer 120 Coil 121-125 Conductor pattern 121a, 122a 1st and 2nd lead part 131, 132 1st and 2nd external electrode 161, 162 Via electrode

Claims (6)

The first and second surfaces facing each other, including the magnetic body and the coil, connected to the first and second surfaces and connected to the third and fourth surfaces facing each other, the first and second surfaces, and the third And a main body which is connected to the fourth surface and has fifth and sixth surfaces facing each other, and both ends of the coil are exposed through at least the third and fourth surfaces, respectively.
Coil parts including first and second external electrodes respectively disposed on the third and fourth surfaces of the main body and connected to both exposed ends of the coil,
The coil is
A plurality of conductor patterns formed in a strip shape having a gap on each magnetic layer and a conductor pattern formed at regular intervals along one direction in which the plurality of conductor patterns are formed are connected to each other. A via electrode that includes:
The body is
An inner first magnetic body portion surrounded by the coil; and an outer second magnetic body portion of the coil, the second magnetic body portion forming the first magnetic body portion. Ri Do a second magnetic material having a low permeability compared to,
In the main body, a coil component in which the first magnetic body portion and the second magnetic body portion are divided with respect to the coil.   The coil component according to claim 1, wherein the main body is made of a second magnetic body, and further includes covers formed on an upper portion and a lower portion of the main body.   The coil component according to claim 2, wherein the first magnetic body portion of the main body is formed so as to protrude from the outermost side of the coil in the stacking direction of the conductor pattern.   2. The coil according to claim 1, wherein the coil further includes first and second lead portions formed to extend to at least one of the conductor patterns through the third and fourth surfaces of the main body. 4. The coil component according to claim 3.   The first and second external electrodes include first and second connection portions formed on the third and fourth surfaces of the main body, respectively, and the first and second connections of the main body from the first and second connection portions. 5. The coil component according to claim 1, further comprising first and second band portions that respectively extend to a part of the fifth, sixth, and sixth surfaces. Forming a laminate including a coil by a buildup method;
Firing the laminate to form a body;
Forming a first external electrode and a second external electrode so as to be connected to both ends of the coil exposed to the main body,
The laminate is
Printing a material containing a first magnetic body to form a first magnetic body portion;
Printing a conductive paste so as to surround an edge of the first magnetic part to form a conductor pattern;
Forming a via electrode in the conductor pattern;
Repeating the step of printing a material containing a second magnetic body on the edge of the first magnetic body portion so as to cover the conductor pattern to form the second magnetic body portion, thereby forming vias of adjacent conductor patterns Manufacturing of coil components in which an electrode is contacted to form a coil , and in the main body, the first magnetic body part and the second magnetic body part are separated on the basis of the coil. Method.

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