JP2015216338A - Multilayer electronic component and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer electronic component capable of preventing such a problem that the electrical conductivity is reduced by oxidization of an internal coil, even when the firing is performed in a weak reducing atmosphere, and to provide a method of manufacturing the same.SOLUTION: A multilayer electronic component includes a magnetic material body formed by laminating a plurality of magnetic material layers, an internal coil formed in the magnetic material body by electrically connecting a plurality of internal coil patterns 121 formed on the plurality of magnetic material layers, and an external electrode formed on the end face of the magnetic material body and connected with the internal coil. An antioxidation part 125 is formed in the internal coil pattern including the lead-out part 123 of the internal coil, out of the plurality of internal coil patterns. Porosity of the antioxidation part is 3%-25%.

Description

  The present invention relates to a multilayer electronic component and a method for manufacturing the same.

  An inductor, which is one of electronic components, is a typical passive element that forms an electronic circuit together with a resistor and a capacitor to remove noise. The inductor is used in a configuration of a resonance circuit, a filter circuit, or the like that amplifies a signal in a specific frequency band in combination with a capacitor using its electromagnetic characteristics.

  Recently, power consumption has increased due to the need for downsizing and higher performance of electronic devices. With such an increase in power consumption, the switching frequency (Switching Frequency) of a PMIC (Power Management Integrated Circuit) or a DC-DC converter (DC-DC Converter) used in a power supply circuit of an electronic device is increased, and an output current is increased. Has increased. Therefore, the use of a power inductor used for stabilizing the output current of the PMIC or the DC-DC converter tends to increase.

  In such a tendency, as a power inductor used in a DC-DC converter circuit, a wound inductor having a form in which a conductive wire is wound around a metal-based magnetic material has been widely used. However, such an inductor has a fundamental limitation in miniaturization. Therefore, in recent years, the use of multilayer inductors is increasing instead of wire wound inductors.

  The multilayer inductor is manufactured through a series of processes such as via hole drilling, lamination, and firing by printing an internal conductor on a magnetic sheet.

At this time, in order to prevent oxidation of the inner conductor, when the heat treatment firing process is performed in a reducing atmosphere such as N ₂ and H ₂ , the magnetic characteristics are deteriorated due to the reduction of ferrite, which is a magnetic material. There is. Therefore, firing of the ferrite multilayer inductor must be performed in a weak reducing atmosphere such as Ni / NiO equilibrium oxygen partial pressure.

  However, when firing in a weak reducing atmosphere to prevent the deterioration of magnetic properties due to the reduction of ferrite as described above, the lead portion of the internal coil comes into contact with oxygen and oxidation occurs, reducing electrical conductivity. There was a problem.

  In particular, there is a tendency to replace the material of the internal coil from expensive silver (Ag) to inexpensive copper (Cu) in order to reduce manufacturing costs. However, since copper (Cu) is more easily oxidized than silver (Ag), in order to replace the material of the internal coil with copper (Cu), it is necessary to solve the internal coil oxidation problem in the weak reducing atmosphere as described above. There is.

Korean Published Patent No. 2011-0128554

  One embodiment of the present invention provides a multilayer electronic component that can prevent problems such as a decrease in electrical conductivity due to oxidation of an internal coil portion even when firing in a weak reducing atmosphere, and a method for manufacturing the same. That is the purpose.

  According to one embodiment of the present invention, a magnetic body formed by laminating a plurality of magnetic layers and a plurality of internal coil patterns formed on the plurality of magnetic layers are electrically connected, An internal coil portion formed inside the magnetic body, and an external electrode formed on an end surface of the magnetic body and connected to the internal coil portion, and the internal coil pattern among the plurality of internal coil patterns. An antioxidant part is formed in the internal coil pattern including the lead part of the coil part, and a multilayer electronic component in which the porosity of the antioxidant part is 3% to 25% is provided.

  The antioxidant portion may be formed only in a partial region including the lead portion of the internal coil portion of the internal coil pattern including the lead portion of the internal coil portion.

  The antioxidant portion may be formed on the entire internal coil pattern including the lead portion of the internal coil portion.

  The porosity of the antioxidant portion may be 3% to 25% greater than the porosity of the internal coil pattern in which the antioxidant portion is not formed.

  The diameter of the space of the antioxidant portion may be 0.3 μm to 15 μm.

  The internal coil portion can contain copper (Cu).

  The magnetic body is selected from the group consisting of Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, Ba ferrite, and Li ferrite. Can contain more than one.

  According to another embodiment of the present invention, a step of manufacturing a plurality of magnetic sheets, a step of forming an internal coil pattern on the magnetic sheet, and a magnetic sheet on which the internal coil pattern is formed. By laminating, a magnetic body having an internal coil portion is formed and sintered, and an external electrode connected to the lead portion of the internal coil portion is formed on the end surface of the sintered magnetic body. And forming the internal coil pattern includes forming an antioxidant portion in the internal coil pattern including the lead portion of the internal coil portion of the internal coil pattern. A method for manufacturing a component is provided.

  The antioxidant portion may be formed only in a partial region including the lead portion of the internal coil portion in the internal coil pattern including the lead portion of the internal coil portion.

  The antioxidant portion may be formed on the entire internal coil pattern including the lead portion of the internal coil portion.

  The internal coil pattern can be formed of a conductive paste containing copper (Cu).

  The antioxidant may include copper (Cu), and one or more reducing agents selected from the group consisting of carbon, graphene, BN (boron nitride), and NaHS (sodium hydrogen sulfide). The conductive paste can be formed.

  The conductive paste that forms the antioxidant part may contain 0.1 to 30% by weight of the reducing agent.

  The reducing agent can be thermally decomposed during the sintering step to form voids in the antioxidant portion.

  The porosity of the antioxidant portion may be 3% to 25%.

  The magnetic body is selected from the group consisting of Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, Ba ferrite, and Li ferrite. Can contain more than one.

  The sintering step can be performed at 850 ° C to 1100 ° C.

  According to one embodiment of the present invention, problems such as a decrease in electrical conductivity due to oxidation of the internal coil portion can be prevented even when firing is performed in a weak reducing atmosphere.

  In addition, since the firing is performed in a weak reducing atmosphere, it is possible to prevent a decrease in magnetic properties due to the reduction of ferrite, and the material of the internal coil portion can be replaced with inexpensive copper (Cu), thereby reducing the manufacturing cost. it can.

1 is a perspective view of a multilayer electronic component according to an embodiment of the present invention. It is sectional drawing along the AA 'line of FIG. FIG. 3 is an exploded perspective view of the multilayer electronic component according to the embodiment of the present invention in FIG. 2. 1 is a cross-sectional view of a multilayer electronic component according to an embodiment of the present invention. FIG. 5 is an exploded perspective view of the multilayer electronic component according to the embodiment of the present invention of FIG. 4. It is process drawing which showed the manufacturing method of the multilayer electronic component by one Embodiment of this invention.

  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.

Multilayer Electronic Component Hereinafter, a multilayer electronic component according to an embodiment of the present invention will be described using a multilayer inductor as an example, but the present invention is not limited thereto.

  FIG. 1 is a perspective view of a multilayer electronic component according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG.

  Referring to FIGS. 1 and 2, a multilayer electronic component 100 according to an embodiment of the present invention includes a magnetic body 110, an internal coil unit 120, and an external electrode 130.

  The magnetic body 110 is formed by laminating a plurality of magnetic layers. The plurality of magnetic layers constituting the magnetic body 110 are in a sintered state, and the boundary between adjacent magnetic layers cannot be confirmed without using a scanning electron microscope (SEM). Can be integrated as much.

  The magnetic body 110 may have a hexahedral shape. In order to clearly describe the embodiment of the present invention, the hexahedral direction is defined. L, W, and T displayed in FIG. 1 indicate a length direction, a width direction, and a thickness direction, respectively.

  The magnetic body 110 may contain known ferrites such as Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, Ba ferrite and Li ferrite. it can.

  The internal coil unit 120 includes an internal coil pattern 121 formed by printing a conductive paste containing a conductive metal in a predetermined thickness on a plurality of magnetic layers constituting the magnetic body 110. Can do.

  Vias are formed at predetermined positions of the magnetic layers on which the internal coil patterns 121 are printed, and the internal coil patterns 121 formed on the magnetic layers are electrically connected to each other through the vias. Connected to form one coil.

  The conductive metal forming the internal coil pattern 121 is not particularly limited as long as it is a metal having excellent electrical conductivity. For example, silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), Titanium (Ti), gold (Au), copper (Cu), or platinum (Pt) can be used alone or in a mixed form. Considering both aspects of improving electrical conductivity and reducing manufacturing costs, it is most preferable to use copper (Cu).

  Of the plurality of internal coil patterns 121 forming the internal coil part 120, the antioxidant part 125 may be formed in the internal coil pattern 121 including the lead part 123 of the internal coil part 120.

  When the heat treatment baking process is performed in a weak reducing atmosphere, the lead-out part 123 of the internal coil part 120 exposed to the outside is oxidized, and the electrical conductivity decreases. In particular, when the internal coil portion 120 is formed of copper (Cu), it is more easily oxidized.

  Therefore, according to an embodiment of the present invention, the internal coil portion is formed even when firing is performed in a weak reducing atmosphere by forming the antioxidant portion 125 in the internal coil pattern 121 including the lead portion 123 of the internal coil portion 120. A decrease in electrical conductivity due to the oxidation of 120 can be prevented.

  The anti-oxidation unit 125 may be selected from the group consisting of carbon, graphene, BN (boron nitride), and NaHS (sodium hydrogen sulfide) in a conductive paste containing a conductive metal. It can be formed by adding one or more reducing agents and printing. The reducing agent can be thermally decomposed during the firing process to form voids. Accordingly, the porosity of the antioxidant 125 may be 3% to 25%.

  The measurement of the porosity can be performed using a transmission electron microscope (TEM), a scanning electron microscope (SEM), or the like. When measuring with an electron microscope, the porosity can be determined by taking an electron micrograph and analyzing the cross section. In addition, the porosity when the pore size is smaller than 100 nm can be measured by observing with a transmission electron microscope by slicing by an ultramicrotome method or an ion milling method. .

  When the porosity of the oxidation preventing portion 125 is less than 3%, the reducing agent for preventing the oxidation of the internal coil portion 120 is insufficient, and the lead-out portion 123 of the internal coil portion 120 is oxidized, and the electrical conductivity is increased. May decrease. Moreover, when the porosity of the antioxidant part 125 exceeds 25%, the resistance value may increase.

  The porosity of the antioxidant part 125 may be 3% to 25% greater than the porosity of the internal coil pattern 121 in which the antioxidant part 125 is not formed.

  The diameter of the air gap formed in the antioxidant part 125 may be 0.3 μm to 15 μm.

  3 is an exploded perspective view of the multilayer electronic component of FIG. 2 according to an embodiment of the present invention.

  Referring to FIG. 3, the antioxidant part 125 may be formed on the entire internal coil pattern including the lead part 123 of the internal coil part 120. For example, the antioxidant part 125 may be formed on the inner coil pattern of the outermost layer of the inner coil part 120 including the lead part 123.

  FIG. 4 is a cross-sectional view of a multilayer electronic component according to an embodiment of the present invention, and FIG. 5 is an exploded perspective view of the multilayer electronic component according to the embodiment of the present invention of FIG.

  Referring to FIGS. 4 and 5, the oxidation preventing part 125 is formed only in a part of the internal coil pattern 121 including the lead part 123 of the internal coil part 120 including the lead part 123 of the internal coil part 120. Can be done.

  By forming the oxidation preventing part 125 only in a part of the internal coil pattern 121 including the lead part 123 of the internal coil part 120 exposed to the outside, the oxidation of the internal coil part 120 is prevented and the oxidation prevention is also achieved. The increase in resistance due to the formation of the portion 125 can be minimized.

  The external electrode 130 may be formed on both end surfaces of the magnetic body 110 so as to be connected to the lead portions 123 of the internal coil part 120 exposed on both end surfaces of the magnetic body 110.

  The external electrode 130 may be formed on both end surfaces in the length direction of the magnetic body 110, and may extend to both end surfaces in the thickness direction and / or both end surfaces in the width direction of the magnetic body 110. Can do.

  The external electrode 130 may be formed by containing a metal having excellent electrical conductivity. For example, the external electrode 130 may be formed of nickel (Ni), copper (Cu), tin (Sn), silver (Ag) or the like alone or an alloy thereof.

Manufacturing Method for Multilayer Electronic Component FIG. 6 is a process diagram showing a method for manufacturing a multilayer electronic component according to an embodiment of the present invention.

  Referring to FIG. 6, first, a plurality of magnetic sheets 111 ′ can be manufactured.

  The magnetic material used for manufacturing the magnetic sheet 111 ′ is not particularly limited. For example, Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, and Ba Known ferrite powders such as ferrite and Li-based ferrite can be used.

  A plurality of magnetic sheets 111 ′ can be manufactured by applying and drying a slurry prepared by mixing the magnetic substance and the organic substance on a carrier film.

  Next, the internal coil pattern 121 can be formed on the magnetic sheet 111 ′.

  The internal coil pattern 121 can be formed by applying a conductive paste containing a conductive metal onto the magnetic sheet 111 ′ by a printing method or the like. As a printing method of the conductive paste, a screen printing method or a gravure printing method can be used, but the present invention is not limited to this.

  The conductive metal is not particularly limited as long as it has excellent electrical conductivity. For example, silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold ( Au), copper (Cu), or platinum (Pt) can be used alone or in a mixed form. In consideration of both improvement of electrical conductivity and reduction of manufacturing cost, it is most preferable to use copper (Cu).

  At this time, among the plurality of internal coil patterns 121 formed on the plurality of magnetic sheets 111 ′, the antioxidant part 125 can be formed in the internal coil pattern 121 including the lead part 123 of the internal coil part 120.

  When the heat treatment firing process is performed in a weak reducing atmosphere, the lead-out part 123 of the internal coil part 120 exposed to the outside is oxidized, and the electrical conductivity is reduced. In particular, when the internal coil portion 120 is formed of copper (Cu), it is more easily oxidized.

  Therefore, according to an embodiment of the present invention, the internal coil portion is formed even when firing is performed in a weak reducing atmosphere by forming the antioxidant portion 125 in the internal coil pattern 121 including the lead portion 123 of the internal coil portion 120. A decrease in electrical conductivity due to the oxidation of 120 can be prevented.

  The anti-oxidation unit 125 may be selected from the group consisting of carbon, graphene, BN (boron nitride), and NaHS (sodium hydrogen sulfide) in a conductive paste containing a conductive metal. It can be formed by adding one or more reducing agents and printing.

  The conductive paste forming the antioxidant part 125 may contain 0.1 to 30% by weight of the reducing agent.

  When the content of the reducing agent is less than 0.1% by weight, the reducing agent for preventing the oxidation of the internal coil portion 120 is insufficient, and the lead-out portion 123 of the internal coil portion 120 is oxidized, and the electrical conductivity is reduced. May decrease. Moreover, when the content of the reducing agent exceeds 30% by weight, the resistance value may increase.

  The antioxidant part 125 may be formed on the entire internal coil pattern including the lead part 123 of the internal coil part 120. For example, the antioxidant part 125 can be formed in the inner coil pattern of the outermost layer of the inner coil part 120 including the lead part 123.

  On the other hand, the antioxidant part 125 can be formed only in a part of the internal coil pattern 121 including the lead part 123 of the internal coil part 120 including the lead part 123 of the internal coil part 120.

  By forming the oxidation preventing part 125 only in a part of the internal coil pattern 121 including the lead part 123 of the internal coil part 120 exposed to the outside, the oxidation of the internal coil part 120 is prevented and the oxidation prevention is also achieved. The increase in resistance due to the formation of the portion 125 can be minimized.

  Next, by laminating the magnetic sheet 111 ′ on which the internal coil pattern 121 and the antioxidant part 125 are formed, the magnetic body 110 on which the internal coil part 120 is formed can be formed and sintered.

  At this time, when the magnetic body 110 formed by laminating the magnetic sheets 111 ′ containing ferrite is fired in a reducing atmosphere, the magnetic properties may be deteriorated due to reduction of the ferrite. Therefore, the magnetic body 110 containing ferrite can be sintered in a weak reducing atmosphere. At this time, the sintering temperature may be 850 ° C to 1100 ° C.

  In the sintering process, the reducing agent contained in the antioxidant 125 can be thermally decomposed to form voids. Accordingly, the porosity of the antioxidant 125 may be 3% to 25%.

  Next, the external electrode 130 connected to the lead-out part 123 of the internal coil part 120 can be formed on the end face of the sintered magnetic body 110.

  The external electrode 130 can be formed using a conductive paste containing a metal having excellent electrical conductivity. The conductive paste can contain, for example, nickel (Ni), copper (Cu), tin (Sn), or silver (Ag) alone or an alloy thereof. The external electrode 130 can be formed by performing not only a printing method but also a dipping method according to the shape of the external electrode 130.

  In addition, description of the same parts as those of the multilayer electronic component according to the embodiment of the present invention is 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 Laminated type electronic component 121 Internal coil pattern 110 Magnetic body main body 123 Leading part 111 'of internal coil part Magnetic material sheet 125 Antioxidation part 120 Internal coil part 130 External electrode

Claims (17)

A magnetic body formed by laminating a plurality of magnetic layers;
A plurality of internal coil patterns formed on the plurality of magnetic layers are electrically connected, and an internal coil portion formed inside the magnetic body,
An external electrode formed on an end surface of the magnetic body and connected to the internal coil portion;
Of the plurality of internal coil patterns, an internal coil pattern including a lead-out portion of the internal coil portion has an antioxidant portion, and the porosity of the antioxidant portion is 3% to 25%. parts.   2. The multilayer electronic component according to claim 1, wherein the oxidation preventing portion is formed only in a partial region including the lead portion of the internal coil portion of the internal coil pattern including the lead portion of the internal coil portion.   2. The multilayer electronic component according to claim 1, wherein the antioxidant portion is formed on an entire internal coil pattern including a lead portion of the internal coil portion.   2. The multilayer electronic component according to claim 1, wherein the porosity of the antioxidant portion is 3% to 25% larger than the porosity of the internal coil pattern in which the antioxidant portion is not formed.   2. The multilayer electronic component according to claim 1, wherein a diameter of a gap of the antioxidant portion is 0.3 μm to 15 μm.   The multilayer electronic component according to claim 1, wherein the internal coil portion contains copper (Cu).   The magnetic body is selected from the group consisting of Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, Ba ferrite, and Li ferrite. The multilayer electronic component according to claim 1, comprising at least one. Producing a plurality of magnetic sheets;
Forming an internal coil pattern on the magnetic sheet;
Laminating and sintering the magnetic body sheet on which the internal coil portion is formed by laminating the magnetic sheet on which the internal coil pattern is formed; and
Forming an external electrode connected to the lead portion of the internal coil portion on the end surface of the sintered magnetic body, and
The step of forming the internal coil pattern includes forming an antioxidant portion on the internal coil pattern including the lead portion of the internal coil portion of the internal coil pattern.   9. The multilayer electronic component according to claim 8, wherein the antioxidant portion is formed only in a partial region including the lead portion of the internal coil portion of the internal coil pattern including the lead portion of the internal coil portion. Method.   The method for manufacturing a multilayer electronic component according to claim 8, wherein the antioxidant portion is formed on the entire internal coil pattern including a lead portion of the internal coil portion.   The method for manufacturing a multilayer electronic component according to claim 8, wherein the internal coil pattern is formed of a conductive paste containing copper (Cu).   The antioxidant may include copper (Cu), one or more reducing agents selected from the group consisting of carbon, graphene, BN (boron nitride), and NaHS (sodium hydrogen sulfide). The method for manufacturing a multilayer electronic component according to claim 8, wherein the method is formed with a conductive paste contained.   The method for manufacturing a multilayer electronic component according to claim 12, wherein the conductive paste forming the antioxidant part contains 0.1% by weight to 30% by weight of the reducing agent.   The method of manufacturing a multilayer electronic component according to claim 12, wherein the reducing agent is thermally decomposed during the sintering step to form a void in the antioxidant portion.   The method for manufacturing a multilayer electronic component according to claim 14, wherein a porosity of the antioxidant portion is 3% to 25%.   The magnetic body is selected from the group consisting of Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Cu ferrite, Mn—Mg ferrite, Ba ferrite, and Li ferrite. The manufacturing method of the multilayer electronic component of Claim 8 containing two or more.   The method for manufacturing a multilayer electronic component according to claim 8, wherein the sintering is performed at 850 ° C. to 1100 ° C.

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