WO2018079062A1 - Method for producing coil component, coil component and dc-dc converter - Google Patents

Abstract

Provided is a method for producing a coil component, which is capable of further improving the performance of a coil component. A method for producing a coil component according to the present invention comprises: a step for preparing an element in which a plurality of metal pins are embedded in such a manner that one end parts of the plurality of metal pins are exposed in a first surface of the element, which is a molded body that contains magnetic material particles, and the other end parts of the plurality of metal pins are exposed in a second surface of the element; a step for arranging a plurality of metal plates supported by a support member on the first surface of the element such that one end part of one metal pin and one end part of another metal pin are electrically connected to each other by a metal plate in the first surface of the element; a step for arranging a plurality of conductors on the first surface of the element such that the other end part of one metal pin and the other end part of another metal pin are electrically connected to each other by a conductor in the second surface of the element; and a step for removing at least a part of the support member after electrically connecting the one end parts of the plurality of metal pins and the plurality of metal plates to each other.

Description

Coil component manufacturing method, coil component, and DC-DC converter

The present invention relates to a method for manufacturing a coil component used for a power inductor or the like of a power supply circuit, a coil component, and a DC-DC converter including the coil component.

Conventionally, as a method for manufacturing this type of coil component, for example, the one disclosed in Patent Document 1 is known. Patent Document 1 discloses a method of manufacturing a coil component in which a coil conductor is embedded in an element body that is a molded body including magnetic particles.

JP2015-88545A

However, in the method for manufacturing a coil component of Patent Document 1, there is still room for improvement in terms of further improving the performance of the coil component.

An object of the present invention is to solve the above-described problems, and to provide a coil component manufacturing method, a coil component, and a DC-DC converter including the coil component that can further improve the performance of the coil component. It is in.

In order to achieve the above object, a method for manufacturing a coil component according to an aspect of the present invention includes:
One end portions of a plurality of metal pins are exposed on the first surface of the element body, which is a molded body including magnetic particles, and the plurality of metals are exposed on the second surface of the element body facing the first surface. Preparing the element body in which the plurality of metal pins are embedded so that the other end of the pin is exposed;
In the first surface of the element body, a plurality of the metals supported by the support member so as to electrically connect one end of one metal pin and one end of the other metal pin with a metal plate Placing a plate on the first surface of the element body;
In the second surface of the element body, a plurality of the conductors are connected to the element body so that the other end part of one metal pin and the other end part of the other metal pin are electrically connected by a conductor. Placing on the second surface;
Removing at least a part of the support member after the one end portions of the plurality of metal pins and the plurality of metal plates are electrically connected;
Including
The plurality of metal pins, the plurality of metal plates, and the plurality of conductors constitute a coil conductor.

A coil component according to an aspect of the present invention is provided.
An element body that is a compact including magnetic particles;
An element body that is a compact including magnetic particles;
Plural embedded in the element body such that one end portion is exposed at the first surface of the element body and the other end portion is exposed at the second surface of the element body facing the first surface. With metal pins,
A plurality of elements disposed on the first surface of the element body so as to electrically connect one end portion of one metal pin and one end portion of the other metal pin on the first surface of the element body. With a metal plate,
The second surface of the element body is disposed on the second surface of the element body so as to electrically connect the other end of one metal pin and the other end of the other metal pin. A plurality of conductors,
With
A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
A gap is provided between the plurality of metal plates and the first surface of the element body.

A DC-DC converter according to an aspect of the present invention includes:
A DC-DC converter comprising a switching element and a choke coil connected to the switching element,
The choke coil is
An element body that is a compact including magnetic particles;
Plural embedded in the element body such that one end portion is exposed on the first surface of the element body and the other end portion is exposed on the second surface of the element body facing the first surface. With metal pins,
A plurality of elements disposed on the first surface of the element body so as to electrically connect one end portion of one metal pin and one end portion of the other metal pin on the first surface of the element body. With a metal plate,
The second surface of the element body is disposed on the second surface of the element body so as to electrically connect the other end of one metal pin and the other end of the other metal pin. A plurality of conductors,
With
A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
A gap is provided between the plurality of metal plates and the first surface of the element body.

The coil component manufacturing method, the coil component, and the DC-DC converter according to the present invention can further improve the performance of the coil component.

It is sectional drawing which shows schematic structure of the coil component which concerns on Embodiment 1 of this invention. FIG. 2 is a cross-sectional view taken along line A1-A1 of FIG. FIG. 3 is a sectional view taken along line B1-B1 of FIG. It is a top view which shows schematic structure of the coil component of FIG. 1, and is a figure which shows the positional relationship of a some metal pin and a some metal plate. It is a bottom view which shows schematic structure of the coil component of FIG. 1, and is a figure which shows the positional relationship of a some metal pin and a some metal plate. It is sectional drawing which shows typically 1 process of the manufacturing method of the coil components which concern on Embodiment 1 of this invention. It is a perspective view which shows typically 1 process of the manufacturing method of the coil components which concern on Embodiment 1 of this invention. FIG. 7 is a cross-sectional view showing a step that follows FIG. 6. FIG. 9 is a cross-sectional view showing a step that follows FIG. 8. FIG. 10 is a cross-sectional view showing a step that follows FIG. 9. It is sectional drawing which shows the process following FIG. FIG. 12 is a perspective view illustrating a process following the process in FIG. 11. It is a perspective view which shows 1 process of the manufacturing method of the hoop material used for the manufacturing method of the coil components of FIG. FIG. 14 is a perspective view showing a step following FIG. 13. FIG. 15 is a perspective view illustrating a process following FIG. 14. It is a perspective view which shows the positional relationship of the hoop material used for the manufacturing method of the coil components of FIG. 1, and a some metal pin. It is a perspective view which shows the modification of a hoop material. It is sectional drawing which shows the modification which provided the magnetic member in the center part of the coil components of FIG. FIG. 2 is a perspective view of a DC-DC converter including the coil component of FIG. 1. FIG. 20 is a circuit diagram of the DC-DC converter of FIG. 19. It is a perspective view which shows schematic structure of the coil component which concerns on Embodiment 2 of this invention. FIG. 22 is a sectional view taken along line A2-A2 of FIG. It is a perspective view which shows the positional relationship of the hoop material used for the manufacturing method of the coil components of FIG. 21, and a some metal pin.

(Knowledge that became the basis of the present invention)
As a result of intensive studies to further improve the performance of the coil component, the present inventors have obtained the following knowledge.

In the manufacturing method of Patent Literature 1, an element body that is a molded body including magnetic particles is subjected to primary molding, and a coil conductor is inserted into a protrusion provided on the element body, and then the coil conductor is covered. A coil component is manufactured by secondary-molding the element body. In this manufacturing method, during the secondary molding, a compressive force is applied to the coil conductor in the winding axis direction, and the coil conductor is compressed while intersecting the winding axis direction between the wires constituting the coil conductor. The element body invades in the direction. For this reason, it is easy to produce variation in the space | interval between each wire. When the variation occurs, the L value is not constant, and it is difficult to produce a coil component with a narrow deviation.

On the other hand, the present inventors embed a plurality of metal pins constituting a part of the coil conductor so as to penetrate the element body, and each of the plurality of metal pins exposed on both surfaces of the element body. The manufacturing method which connected the end part electrically with the some conductor which comprises the remainder of a coil conductor was discovered. According to this manufacturing method, it becomes possible to make the space | interval between metal pins constant so that force may not be applied to the direction which cross | intersects an axial direction with respect to each metal pin. As a result, the L value can be kept constant, the performance of the coil component can be maintained or improved, and the L value deviation variation characteristic can be reduced. Therefore, the gap between the coil conductors as in Patent Document 1 is unlikely to vary.

Furthermore, the inventors use a metal plate as at least a part of the plurality of conductors that electrically connect the respective ends of the plurality of metal pins, and a gap is formed between the metal plate and the surface of the element body. The manufacturing method which provides is found. According to this manufacturing method, since a metal plate having a low DC resistance is used for connecting metal pins, a coil component with a small loss can be obtained.

Based on these points, the present inventors have reached the following invention.

A method for manufacturing a coil component according to an aspect of the present invention includes:
One end portions of a plurality of metal pins are exposed on the first surface of the element body, which is a molded body including magnetic particles, and the plurality of metals are exposed on the second surface of the element body facing the first surface. Preparing the element body in which the plurality of metal pins are embedded so that the other end of the pin is exposed;
In the first surface of the element body, a plurality of the metals supported by the support member so as to electrically connect one end of one metal pin and one end of the other metal pin with a metal plate Placing a plate on the first surface of the element body;
In the second surface of the element body, a plurality of the conductors are connected to the element body so that the other end part of one metal pin and the other end part of the other metal pin are electrically connected by a conductor. Placing on the second surface;
Removing at least a part of the support member after the one end portions of the plurality of metal pins and the plurality of metal plates are electrically connected;
Including
The plurality of metal pins, the plurality of metal plates, and the plurality of conductors constitute a coil conductor.

According to this manufacturing method, since a metal plate having a low DC resistance is used for connecting metal pins on at least one surface side, a coil component with a small loss can be obtained.

The plurality of metal plates and the support member are formed of a hoop material obtained by etching or punching a metal sheet, and one end portions of the plurality of metal pins and the plurality of metal plates are electrically connected. Thereafter, the support member and the plurality of metal plates may be separated and the support member may be removed. Thereby, the coil component of this invention which has a metal plate can be manufactured more easily.

Further, it may further include a step of forming a covering member so as to cover the first surface of the element body. Thereby, it is possible to prevent the coil conductor from being exposed to the outside.

In addition, the covering member may be a covering element that is a molded body including magnetic particles. Thereby, the whole coil conductor can be embedded in the element body.

Further, the hoop material includes an electrode portion that becomes a terminal electrode of the coil component, and the electrode portion is located on the first surface side of the element body even after the support member is removed, and the covering member May be formed so as to cover the first surface of the element body excluding the electrode portion so that the electrode portion is exposed to the outside. Thereby, it is possible to eliminate the necessity of separately forming the electrode part of the coil component, and it is possible to manufacture the coil component more easily.

Further, the hoop material may be bent so that the electrode portion is located on a plane away from the plane on which the plurality of metal plates and the support member are located. Thereby, it is possible to eliminate the necessity of separately forming the electrode part of the coil component, and it is possible to manufacture the coil component more easily. The effect is particularly great when the coil conductors are all embedded in the element body.

In addition, a conductive bonding material is provided at one end of each of the plurality of metal pins exposed on the first surface of the element body, and the plurality of metal plates are bonded onto the conductive bonding material. The support member may be disposed on the first surface of the element body. Thereby, a coil component can be manufactured more easily. Moreover, since a conductive bonding material exists between the metal pin and the metal plate, it is possible to easily provide a gap between the metal plate and the surface of the element body.

In addition, the element body has a higher magnetic permeability than the element body in a region located between the plurality of metal pins and between the first surface and the second surface of the element body. A member may be embedded. Thereby, the relative magnetic permeability of the whole coil component can be improved.

Further, the magnetic particles may be a magnetic metal powder, and the element body may be a green compact including the magnetic metal powder. This compacting body is obtained by compression molding a magnetic metal powder through a binder such as a resin, and can increase the content of the magnetic metal powder in the element body. For this reason, it is possible to configure a coil component that hardly causes magnetic saturation and has excellent direct current superposition characteristics. In addition, the compacting body does not need to contain resin.

The magnetic particles may include a composite magnetic material.

In addition, a plurality of coil conductors may be formed in the element body, and the element body may further include a step of cutting the element body into individual coil parts including one coil conductor. Thereby, a plurality of coil parts can be manufactured more easily.

Further, the conductor is a metal plate, and the metal plate is disposed so as to have a gap with the back surface of the element body, and is exposed at the second surface of the element body. May be electrically connected. As a result, a metal plate having a low DC resistance is used for connecting the metal pins on both the first surface and the second surface of the element body, so that a coil component with even smaller loss can be obtained.

Moreover, the coil component which concerns on 1 aspect of this invention,
An element body that is a compact including magnetic particles;
Plural embedded in the element body such that one end portion is exposed at the first surface of the element body and the other end portion is exposed at the second surface of the element body facing the first surface. With metal pins,
A plurality of elements disposed on the first surface of the element body so as to electrically connect one end portion of one metal pin and one end portion of the other metal pin on the first surface of the element body. With a metal plate,
The second surface of the element body is disposed on the second surface of the element body so as to electrically connect the other end of one metal pin and the other end of the other metal pin. A plurality of conductors,
With
A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
A gap is provided between the plurality of metal plates and the first surface of the element body.

According to this configuration, a plurality of metal pins are embedded in the element body, and a metal plate having a low DC resistance is used to connect the metal pins on at least one surface side. Can do. In addition, since a gap is provided between the metal plate and the first surface of the element body, magnetic saturation can be suppressed. As a result, the performance of the coil component can be further improved.

The average dimension of the gap between the metal plate and the first surface of the element body may be larger than the average dimension of the gap between the outer peripheral surface of the metal pin and the element body. Thereby, magnetic saturation can be suppressed more reliably and the performance of the coil component can be further improved. In addition, since the gap between the outer peripheral surface of the metal pin and the element body is narrow and more closely contacted, characteristics of the element body (particularly, DC superimposition characteristics) can be improved.

In addition, the element body has a higher magnetic permeability than the element body in a region located between the plurality of metal pins and between the first surface and the second surface of the element body. A member may be embedded.

The magnetic particles may include a composite magnetic material.

The DC-DC converter according to one aspect of the present invention includes:
A DC-DC converter comprising a switching element and a choke coil connected to the switching element,
The choke coil is
An element body that is a compact including magnetic particles;
Plural embedded in the element body such that one end portion is exposed at the first surface of the element body and the other end portion is exposed at the second surface of the element body facing the first surface. With metal pins,
A plurality of elements disposed on the first surface of the element body so as to electrically connect one end portion of one metal pin and one end portion of the other metal pin on the first surface of the element body. With a metal plate,
The second surface of the element body is disposed on the second surface of the element body so as to electrically connect the other end of one metal pin and the other end of the other metal pin. A plurality of conductors,
With
A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
A gap is provided between the plurality of metal plates and the first surface of the element body.

According to this configuration, a plurality of metal pins are embedded in the element body, and a metal plate having a low DC resistance is used to connect the metal pins on at least one surface side. Can do. In addition, since a gap is provided between the metal plate and the first surface of the element body, magnetic saturation can be suppressed. As a result, the performance of the choke coil component can be further improved.

The magnetic particles may include a composite magnetic material.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
A configuration of a coil component manufactured by the method of manufacturing a coil component according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a perspective view showing a schematic configuration of the coil component. 2 is a cross-sectional view taken along line A1-A1 of FIG. 3 is a cross-sectional view taken along line B1-B1 of FIG.

As shown in FIGS. 1 to 3, the coil component 1 according to the present embodiment includes a rectangular parallelepiped element body 2 and a covering member that is an example of a covering member provided so as to cover the surface 2a of the element body 2. An element body 3 and a covering element body 4 which is an example of a covering member provided so as to cover the back surface 2b of the element body 2 are provided. A pair of electrode portions 5 serving as terminal electrodes are provided on the surface 3a of the covering element 3 so as to be exposed. In the present embodiment, the front surface 2 a is the first surface of the element body 2, and the back surface 2 b is the second surface of the element body 2.

The element body 2 and the covering elements 3 and 4 are formed bodies including magnetic particles. The element body 2 contains 80% by volume or more, preferably 95% by volume or more of magnetic particles. The base body 2 and the covering base bodies 3 and 4 are preferably a composite magnetic body in which magnetic particles are dispersed in a binder, in particular, a metal composite material in which magnetic metal powder is dispersed in a binder (resin). For example, it has a structure in which iron-based magnetic metal powder is compacted with a thermosetting binder resin (for example, epoxy resin). The magnetic particles of the iron-based magnetic metal powder may be, for example, iron obtained by adding manganese or chromium as an additive. The element body 2 may be a molded body that does not contain a binder resin, forms an oxide film as an insulator on the surface of the magnetic particles, and is formed so that crystals forming the oxide film are connected to each other. . In this case, the oxide films between the magnetic particles may be connected to each other. Further, the oxide film crystals may be continuously connected.

The iron-based magnetic metal powder may contain additives such as Mn and Cr or impurities. The binder is, for example, an epoxy resin. The magnetic particles are not limited to iron-based magnetic metal powder. Ferrite powder or the like may be used as the magnetic particles. When iron-based magnetic metal powder is used as the magnetic particles, it has a high relative magnetic permeability and is not easily saturated, so that it is useful as a coil component for a power inductor.

The element body 2 can be formed, for example, by compacting after providing a composite magnetic body, in particular, a metal composite material in a printing process or the like. The volume fraction of the magnetic metal powder is, for example, 80% by volume or more, and preferably 95% by volume or more. Since the ratio of magnetic metal powder can be increased, it is useful for power inductors. Moreover, since the packing density of the magnetic metal powder can be increased not only by printing but also by compacting, the relative permeability is high. The element body 2 can be formed by molding the magnetic particles so as to be in contact with each other through an oxide film on the surface without using a binder (resin).

The covering bodies 3 and 4 are a composite magnetic body in which magnetic particles similar to the base body 2 are dispersed in a binder, particularly a metal composite material in which magnetic metal powder is dispersed in the binder, or a binder It is a molded body which does not contain (resin) and is molded so that the magnetic particles come into contact with each other through the oxide film on the surface.

The covering elements 3 and 4 can be provided, for example, by printing the above-described composite magnetic body or the like on the element 2. Note that the present invention is not limited to printing, and may be provided by other methods. When the covering elements 3 and 4 are formed by printing, the relative permeability of the element 2 is higher than the relative permeability of the covering elements 3 and 4.

As shown in FIGS. 2 and 3, a plurality of metal pins 6 are embedded in the element body 2. Each metal pin 6 is provided so as to penetrate the element body 2 in the height direction Z. One end 6a of each metal pin 6 is exposed on the surface 2a of the element body 2, and is electrically connected to a metal plate 8a that is a conductor via a conductive bonding material 7a. Each metal plate 8 a is disposed on the surface 2 a of the element body 2 so as to electrically connect one end 6 a of one metal pin 6 and one end 6 a of the other metal pin 6. A gap CL <b> 1 is provided between each metal plate 8 a and the surface 2 a of the element body 2. The other end 6b of each metal pin 6 is exposed on the back surface 2b of the element body 2, and is electrically connected to a metal plate 8b which is a conductor via a conductive bonding material 7b. Each metal plate 8 b is disposed on the back surface 2 b of the element body 2 so as to electrically connect the other end 6 b of one metal pin 6 and the other end 6 b of the other metal pin 6. A gap CL <b> 2 is provided between each metal plate 8 b and the back surface 2 b of the element body 2. The conductive bonding materials 7a and 7b are, for example, tin / silver solder.

The average dimension of the gaps CL1 and CL2 is, for example, 1 μm or more and 10 μm or less. The metal plates 8a and 8b and the surface 2a of the element body 2 may partially contact each other. That is, the gaps CL1 and CL2 may have a portion that is substantially 0 μm or a portion that is larger than 10 μm. The gaps CL1 and CL2 are not limited to being air layers as long as magnetic saturation can be suppressed. For example, the gaps CL1 and CL2 may be filled with an insulating member such as a resin.

The metal pin 6 is configured by processing a metal lump (bulk) into a pin shape, for example. The diameter of the metal pin 6 is, for example, 100 μm or more and 200 μm or less. Moreover, the metal plates 8a and 8b are configured by processing a metal lump (bulk) into a plate shape, for example. The metal plates 8a and 8b are not formed by vapor deposition or etching, but are metal members that do not substantially contain a resin. The metal plates 8a and 8b are metal members that do not substantially contain a resin. The thickness of the metal plates 8a and 8b is, for example, not less than 50 μm and not more than 200 μm. With this configuration, the DC resistance of the metal pin 6 and the metal plates 8a and 8b can be reduced, and a coil component such as a power inductor with less loss can be realized.

As shown in FIG. 2 and FIG. 15 to be described later, the electrode portion 5 extends two metal plates 8a located on both end sides in the lateral direction (longitudinal direction) X in the coil component 1 in the height direction Z, It is configured by bending along the surface 3 a of the covering element body 3.

FIG. 4 is a plan view showing a schematic configuration of the coil component 1, and is a diagram showing a positional relationship between the plurality of metal pins 6 and the plurality of metal plates 8a. FIG. 5 is a bottom view showing a schematic configuration of the coil component 1, and is a diagram showing a positional relationship between the plurality of metal pins 6 and the plurality of metal plates 8b.

The plurality of metal pins 6 are arranged in two rows in the lateral direction X as shown in FIGS. As shown in FIG. 4, the plurality of metal plates 8 a are arranged so as to extend obliquely with respect to the horizontal direction X and the vertical direction (short direction) Y. The arrangement interval of the metal pins 6 arranged in the horizontal direction X is, for example, 100 μm. The plurality of metal plates 8b are arranged so as to extend in the longitudinal direction Y as shown in FIG. Thereby, the helical coil conductor is comprised by the some metal pin 6 and the some metal plates 8a and 8b.

According to the coil component 1 according to the first embodiment, a plurality of metal pins 6 are embedded in the element body 2, and both ends of the plurality of metal pins 6 are electrically connected by the metal plates 8a and 8b. Since the coil conductor is configured, for example, the direct current resistance is reduced and the loss is reduced as compared with the case where a conductor which is a sintered body of conductive paste is used instead of the metal plates 8a and 8b. Coil parts can be realized. Moreover, since the metal plate (hoop material) itself is a thin plate having elasticity, the impact resistance of the coil component is also improved. In addition, since the gap CL1 is provided between the metal plate 8a and the surface 2a of the element body 2 and the gap CL2 is provided between the metal plate 8b and the back surface 2b of the element body 2, magnetic saturation can be suppressed. it can. As a result, the performance of the coil component 1 can be further improved.

In addition, a gap may occur between the outer peripheral surface of the metal pin 6 and the element body 2 in manufacturing. The average dimension of the gaps CL1 and CL2 is preferably larger than the average dimension of the gap between the outer peripheral surface of the metal pin 6 and the element body 2. In other words, the contact area per unit area between the surface 2a of the element body 2 and the metal plate 8a and the contact area per unit area between the back surface 2b of the element body 2 and the metal plate 8b are the same as the outer peripheral surface of the metal pin 6 and the element surface. It is preferable that the contact area per unit area with the body 2 is smaller. Thereby, magnetic saturation can be suppressed more reliably and the performance of the coil component 1 can be further improved. Moreover, the characteristic (especially direct current superimposition characteristic) of the element body 2 can be improved because the clearance gap between the outer peripheral surface of the metal pin 6 and the element body 2 is narrow and it adheres more closely.

Next, a method for manufacturing the coil component 1 according to the first embodiment of the present invention will be described with reference to FIGS. 6 to 12 are sectional views or perspective views schematically showing the method for manufacturing the coil component 1 according to the first embodiment of the present invention.

First, as shown in FIGS. 6 and 7, a plurality of metal pins 6 are arranged in two rows in the lateral direction X on the base 100.

Next, as shown in FIG. 8, the uncured element body 2 is formed on the pedestal 100 so as to embed a plurality of metal pins 6 therein, and cured (compact molding) to be integrated with the metal pins 6. To do. Thereby, a plurality of metal pins 6 are embedded in the element body 2. Moreover, each metal pin 6 is arrange | positioned so that it may extend in the height direction Z.

Next, as shown in FIG. 9, the surface layer portion of the element body 2 is polished to expose one end portion 6 a of the metal pin 6 from the surface 2 a of the element body 2. Further, the base 100 is removed from the element body 2, and the other end portion 6 b of the metal pin 6 is exposed from the back surface 2 b of the element body 2. As a result, a plurality of metals are exposed such that one end portions 6a of the plurality of metal pins 6 are exposed on the surface 2a of the element body 2 and the other end portions 6b of the plurality of metal pins 6 are exposed on the back surface 2b of the element body 2. The element body 2 in which the pins 6 are embedded is prepared. The surface layer portion of the element body 2 can be polished by, for example, sand blasting. The back surface 2b of the element body 2 may also be polished.

Next, as shown in FIG. 10, the conductive bonding material 7 a is provided at one end 6 a of each metal pin 6, and then the hoop material 10 a is disposed on the surface 2 a of the element body 2. Further, after providing the conductive bonding material 7 b on the other end 6 b of each metal pin 6, the hoop material 10 b is disposed on the back surface 2 b of the element body 2. The hoop material 10a is manufactured, for example, by the manufacturing method shown in FIGS.

First, as shown in FIG. 13, a metal sheet 10 obtained by rolling a metal lump (bulk) is prepared. Next, as shown in FIG. 14, the metal sheet 10 is etched or punched to form a plurality of metal plates 8 a, a support member 11 a that supports the plurality of metal plates 8 a, and a terminal electrode of the coil component 1. A hoop material 10 </ b> A including the electrode portion 5 is formed. At this time, in the hoop material 10A, a plurality of metal plates 8a, support members 11a, and electrode portions 5 are continuously formed without any breaks. In the first embodiment, the support member 11a includes a plurality of gate portions 11aa connected to the plurality of metal plates 8a, and a runner portion 11ab to which the plurality of gate portions 11aa are respectively connected. Next, as shown in FIG. 15, the hoop material 10 </ b> A is bent using, for example, a mold so that the electrode portion 5 is located on a plane away from the plane on which the plurality of metal plates 8 a and the support member 11 a are located. . Thereby, the hoop material 10a is manufactured.

In addition, the hoop material 10b on the back surface side, like the hoop material 10a on the front surface side, etches or punches the metal sheet 10, thereby supporting the plurality of metal plates 8b and the plurality of metal plates 8b. It is manufactured to include the member 11b. At this time, in the hoop material 10b, the plurality of metal plates 8b and the support member 11b are continuously formed without a break. In the first embodiment, the support member 11b includes a plurality of gate portions 11ba connected to the plurality of metal plates 8b and a runner portion 11bb to which the plurality of gate portions 11ba are respectively connected. Since the hoop material 10b on the back surface side does not include the electrode portion 5, the bending process is not performed.

FIG. 16 is a perspective view showing the positional relationship between the hoop materials 10a and 10b and the plurality of metal pins 6. FIG. In FIG. 16, the conductive bonding materials 7a and 7b and the element body 2 are not shown.

As shown in FIG. 16, the hoop material 10 a on the surface side has the surface 2 a of the element body 2 so that each metal plate 8 a is positioned on the conductive bonding material 7 a provided at one end 6 a of each metal pin 6. Placed in. At this time, the thickness of the conductive bonding material 7a is, for example, 30 μm. Then, the metal plate 8a and the one end 6a of the metal pin 6 are electrically connected by curing the conductive bonding material 7a by performing reflow or the like. At this time, the thickness of the conductive bonding material 7a is, for example, 10 μm.

Further, the hoop material 10b on the back surface side is connected to the back surface 2b of the element body 2 so that each metal plate 8b is electrically connected to the other end portion 6b of the metal pin 6 via the conductive bonding material 7b. Be placed. At this time, the thickness of the conductive bonding material 7b is, for example, 30 μm. Thereafter, the metal plate 8b and the other end portion 6b of the metal pin 6 are electrically connected by curing the conductive bonding material 7b by performing reflow or the like. At this time, the thickness of the conductive bonding material 7b is, for example, 10 μm.

Thereafter, the support members 11a and 11b and the plurality of metal plates 8a and 8b are separated, and the support members 11a and 11b are removed leaving the plurality of metal plates 8a and 8b on the front surface 2a or the back surface 2b of the element body 2. The plurality of metal plates 8a can be separated from the gate portion 11aa of the support member 11a, and the plurality of metal plates 8b can be separated from the gate portion 11ba of the support member 11b using, for example, a cutter or a laser. Thereby, a helical coil conductor is comprised by the some metal pin 6 and the some metal plates 8a and 8b. In the first embodiment, two coil conductors serving as two coil parts are formed in one element body 2.

After the process shown in FIG. 10, as shown in FIG. 11, the covering element body 3 is formed so as to cover the surface 2 a of the element body 2, and the covering element body 4 is covered so as to cover the back surface 2 b of the element body 2. Form. At this time, the covering elements 3 and 4 are formed so that the gaps CL1 and CL2 are maintained and the electrode portion 5 is exposed (see FIG. 3). Thereby, the several coil components 1 with which the element | base_body 2 was connected are manufactured. At this time, part of the covering elements 3 and 4 (resin) excluding the magnetic particles may enter the gaps CL1 and CL2. For example, by making the maximum dimension of the gaps CL1 and CL2 smaller than the diameter of the magnetic particles (for example, 30 μm), the magnetic particles can be prevented from entering the gaps CL1 and CL2.

Next, as shown in FIG. 12, the element body 2 is cut using a dicer, for example, along the cutting line L1 shown by the dotted line in FIG. Thereby, the coil component 1 is manufactured.

According to the manufacturing method according to the first embodiment, a plurality of metal pins 6 are embedded in the element body 2, and then a plurality of metal plates 8a and 8b having a low DC resistance are formed to constitute a coil conductor. Therefore, a coil component with a small loss can be obtained. In addition, since the gap CL1 is provided between the metal plate 8a and the surface 2a of the element body 2 and the gap CL2 is provided between the metal plate 8b and the back surface 2b of the element body 2, magnetic saturation can be suppressed. it can. As a result, the performance of the coil component 1 can be further improved.

Moreover, according to the manufacturing method which concerns on this Embodiment 1, while the several metal plate 8a is supported by the supporting member 11a, it is arrange | positioned on the surface 2a of the element | base_body 2, and several metal plate 8b is a supporting member. It is arranged on the back surface 2b of the element body 2 while being supported by 11b. Thereafter, after the one end portions 6a of the plurality of metal pins 6 and the plurality of metal plates 8a are electrically connected, the support member 11a is removed. Further, after the other end portions 6b of the plurality of metal pins 6 and the plurality of metal plates 8b are electrically connected, the support member 11b is removed. Thereby, the electrical connection with the some metal pin 6 and the some metal plates 8a and 8b can be performed more efficiently, and the coil component 1 which has the metal plates 8a and 8b can be manufactured more easily. .

In addition, the manufacturing method according to the first embodiment includes the step of forming the covering elements 3 and 4 so as to cover the front surface 2a and the back surface 2b of the element body 2. Thereby, it is possible to prevent the coil conductor from being exposed to the outside. Further, the entire coil conductor can be embedded in the element body 2 or the covering element bodies 3 and 4 which are formed bodies containing magnetic particles.

Moreover, according to the manufacturing method which concerns on this Embodiment 1, several metal plate 8a, 8b and support member 11a, 11b are comprised by the hoop material 10a, 10b which etched or stamped the metal sheet | seat 10. FIG. . Thereby, the coil component 1 can be manufactured more easily.

In addition, according to the manufacturing method according to the first embodiment, the hoop material 10a includes the electrode part 5 that serves as the terminal electrode of the coil component 1, and the electrode part 5 has the element body 2 even after the support member 11a is removed. It is located on the surface 2a side. Further, the covering element body 3 is formed so as to cover the surface 2a of the element body 2 except for the electrode part 5 so that the electrode part 5 is exposed to the outside. Thereby, the necessity for separately forming the electrode part 5 of the coil component 1 can be eliminated, and the coil component 1 can be manufactured more easily.

Further, according to the manufacturing method according to the first embodiment, the hoop material 10a is bent so that the electrode portion 5 is located on a plane away from the plane where the plurality of metal plates 8a and the support member 11a are located. . Thereby, even if the covering element body 3 is formed, it is possible to eliminate the necessity of separately forming the electrode portion 5 of the coil component 1 and to manufacture the coil component 1 more easily. The effect is particularly great when the coil conductors are all embedded in the element body.

Further, according to the manufacturing method according to the first embodiment, the conductive bonding material 7a is provided on the one end portions 6a of the plurality of metal pins 6 exposed on the surface 2a of the element body 2, and the conductive bonding material 7a is provided on the conductive bonding material 7a. A support member 11b is disposed on the surface 2a of the element body 2 so that the plurality of metal plates 8a are joined. Further, a conductive bonding material 7b is provided on the other end portion 6b of the plurality of metal pins 6 exposed on the back surface 2b of the element body 2, and a plurality of metal plates 8b are bonded on the conductive bonding material 7b. A support member 11 b is disposed on the back surface 2 b of the element body 2. Thereby, the coil component 1 can be manufactured more easily. In addition, since the conductive bonding material 7a exists between the one end 6a of the metal pin 6 and the metal plate 8a, it is possible to easily provide the gap CL1 between the metal plate 8a and the surface 2a of the element body 2. . In addition, since the conductive bonding material 7b exists between the other end 6b of the metal pin 6 and the metal plate 8b, it is easy to provide the gap CL2 between the metal plate 8b and the back surface 2b of the element body 2. it can.

Further, according to the manufacturing method according to the first embodiment, the magnetic particles are magnetic metal powder, and the element body 2 is a compacted body including the magnetic metal powder. This compacted body is obtained by compression-molding magnetic metal powder through a binder such as a resin, and can increase the content (ratio per volume) of the magnetic metal powder in the element body 2. For this reason, the coil component 1 which hardly causes magnetic saturation and has excellent direct current superposition characteristics can be configured. In addition, the compacting body does not need to contain resin.

In addition, according to the manufacturing method according to the first embodiment, a plurality of coil conductors are formed in the element body 2, and the element body 2 is cut so as to become individual coil components 1 including one coil conductor. And the process of singulation. Thereby, the some coil component 1 can be manufactured more easily.

Note that the present invention is not limited to the above-described embodiment, and can be implemented in various other modes. For example, the hoop material 10a is configured so that both ends of the plurality of metal plates 8a are supported by the gate portions 11aa of the support member 11a, but the present invention is not limited to this. For example, you may comprise the hoop material 10a so that only the one end part of the some metal plate 8a may be supported by the gate part 11aa of the supporting member 11a.

In the above description, the hoop material 10b is configured so that both ends of the plurality of metal plates 8b are supported by the gate portion 11ba of the support member 11b. However, the present invention is not limited to this. For example, you may comprise the hoop material 10b so that only the one end part of the some metal plate 8b may be supported by the gate part 11ba of the supporting member 11b.

In the above description, the plurality of metal plates 8a and the gate portion 11aa of the support member 11a are separated, but at this time, a part of the gate portion 11aa may be separated so as to remain on the plurality of metal plates 8a. Similarly, in the above description, the plurality of metal plates 8b and the gate portion 11ba of the support member 11b are separated, but at this time, a part of the gate portion 11ba may be separated so as to remain on the plurality of metal plates 8b. . Thereby, a part of gate part 11aa and a part of gate part 11ba function as an anchor, and it can make it hard to peel off metal plate 8a, 8b.

In the above description, the covering elements 3 and 4 are formed by separating the plurality of metal plates 8a from the gate portion 11aa of the support member 11a and separating the plurality of metal plates 8b from the gate portion 11ba of the support member 11b. Although done before, this invention is not limited to this. The separation may be performed after the covering elements 3 and 4 are formed. For example, when the element body 2 is cut so as to become individual coil components 1 as shown in FIG. The gate portion 11aa and the gate portion 11ba are preferably narrower than the metal plates 8a and 8b. Thereby, the gate part 11aa and the gate part 11ba can be easily cut.

In the above description, the support members 11a and 11b include the gate portions 11aa and 11ba and the runner portions 11ab and 11bb. However, the present invention is not limited to this. For example, the support members 11a and 11b may be any member that can support the plurality of metal plates 8a and 8b, and may be, for example, a transfer film.

In the above description, the covering elements 3 and 4 are used as an example of the covering member, but the present invention is not limited to this. For example, when the coil component 1 is used as an antenna coil instead of a power inductor, the covering member may be a member such as a resin that does not include a magnetic body.

In the above description, a plurality of metal plates 8a and 8b are provided as conductors for connecting the metal pins 6 to both the front surface 2a and the back surface 2b of the element body 2, but the present invention is not limited to this. Conductors other than the metal plates 8a and 8b such as a metal pattern obtained by curing a conductive paste may be provided on one of the front surface 2a and the back surface 2b of the element body 2.

In the above description, the element body 2 is formed after arranging the plurality of metal pins 6 on the base 100, but the present invention is not limited to this. For example, after forming the element body 2, a plurality of metal pins 6 may be embedded in the element body 2.

In the above description, for example, as shown in FIG. 11, an example in which two coil conductors serving as two coil components are formed in the lateral direction X in one element body 2 has been described. It is not limited. Three or more coil conductors serving as three or more coil components may be formed in one element body 2. For example, four coil conductors may be formed in one element body 2 in the horizontal direction X and two in the vertical direction Y (that is, 2 × 2). In this case, for example, instead of the hoop material 10a, as shown in FIG. 17, two hoop materials 10a are arranged adjacent to each other in the longitudinal direction Y, and each of the two hoop materials 10a shares one runner portion 11ab. The hoop material 10Ax configured as described above may be used. Similarly, in place of the hoop material 10b, for example, two hoop materials 10b are arranged adjacent to each other in the longitudinal direction Y, and each of the two hoop materials 10b is configured to share one runner portion 11bb. A material (not shown) may be used. Thereby, the four coil components 1 can be manufactured more easily. In this manner, a desired number of coil conductors are formed in the horizontal direction X and the vertical direction Y in one element body 2, and the element body 2 is cut so as to become individual coil components 1 including one coil conductor. Then, by dividing into pieces, it is possible to more easily manufacture a plurality of X × Y coil components 1. Moreover, what is necessary is just to form each hoop material in the shape according to the desired number at this time.

The covering elements 3 and 4 preferably have a larger relative permeability μ than the element 2. Thereby, magnetic confinement property can be improved.

As shown in FIG. 18, the element body 2 has a relative permeability higher than that of the element body 2 in a region located between the plurality of metal pins 6 and between the front surface 2 a and the back surface 2 b of the element body 2. It is preferable that a high magnetic member 20 (for example, a magnetic member having a relative permeability of 100) is embedded. Thereby, the relative magnetic permeability of the whole coil component 1 can be improved. For example, the relative permeability of the entire coil component 1 can be improved from 30 to 60.

One magnetic member 20 may be provided for one coil component 1. The magnetic member 20 may be a member having a relative permeability higher than that of the element body 2. For example, the magnetic member 20 may be a compacted body including magnetic metal powder, or may be ferrite. When ferrite is used as the magnetic member 20, it is preferably disposed near the center of the coil component 1 so as not to contact each metal pin 6. Thereby, it can suppress that a direct current | flow superimposition characteristic falls. Such an arrangement can be realized, for example, by forming a part of the element body 2, placing the magnetic member 20 on a part of the element body 2, and then forming the remaining part of the element body 2. .

(DC-DC converter)
Next, a configuration example of the DC-DC converter 50 including the coil component 1 according to the first embodiment will be described with reference to FIGS. 19 and 20.

FIG. 19 is a perspective view of the DC-DC converter 50 including the coil component 1. FIG. 20 is a circuit diagram of the DC-DC converter 50 of FIG.

The DC-DC converter 50 is a step-up / step-down DC-DC converter. As shown in FIG. 19, the DC-DC converter 50 has a structure in which a switching element 52, a coil component 1 used as a choke coil, an input capacitor 53, and an output capacitor 54 are mounted on a printed wiring board 51. Have.

The coil component 1 is connected to a switching element 52 as shown in FIG. One end of an input capacitor 53 is connected to the input terminal of the switching element 52. The other end of the input capacitor 53 is grounded. One end of an output capacitor 54 is connected to the output terminal of the switching element 52. The other end of the output capacitor 54 is grounded.

According to this configuration, since the DC-DC converter 50 includes the coil component 1 described above, the performance of the DC-DC converter 50 can be improved, and a DC-DC converter corresponding to a large current can be configured.

(Embodiment 2)
The configuration of the coil component manufactured by the method for manufacturing a coil component according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 21 is a perspective view showing a schematic configuration of the coil component. 22 is a cross-sectional view taken along line A2-A2 of FIG. FIG. 23 is a perspective view showing the positional relationship between the hoop material 10Aa and the plurality of metal pins 6 used in the method for manufacturing a coil component according to Embodiment 2 of the present invention. Note that parts that are the same as or similar to the parts described in the first embodiment are given the same reference numerals, and redundant descriptions are omitted.

The coil component 1A according to the second embodiment is different from the coil component 1 according to the first embodiment in that the electrode portion 5A is provided not on the surface 3a of the covering element body 3 but on the surface 2a of the element body 2. In other words, it is exposed from the opening 3 b provided on the surface 3 a of the covering element 3.

In the second embodiment, the hoop material 10Aa shown in FIG. 23 is used as the hoop material 10a. As shown in FIGS. 22 and 23, the electrode portion 5A is configured by extending two metal plates 8a positioned at both end portions in the horizontal direction X in the coil component 1 in the horizontal direction X and the vertical direction Y. ing.

According to the coil component 1A according to the second embodiment, it is possible to eliminate the necessity of bending the hoop material 10Aa in order to form the electrode portion 5A.

In addition, what is necessary is just to form the covering element | base_body 3 in the state which has arrange | positioned the mask member on the electrode part 5A, for example, in order to expose the electrode part 5A from the opening part 3b provided in the covering element | base_body 3. FIG.

Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

It should be noted that the effects possessed by each of the various embodiments can be achieved by appropriately combining the embodiments.

Since the performance of the coil component can be further improved, the present invention is useful for manufacturing, for example, a choke coil or an antenna coil used for a DC-DC converter.

DESCRIPTION OF SYMBOLS 1,1A Coil component 2 Element body 2a Surface 2b Back surface 3 Covering element 3a Surface 3b Opening 4 Covering element 5,5A Electrode part 6 Metal pin 6a One end part 6b Other end part 7a, 7b Conductive bonding material 8a , 8b Metal plate 10 Metal sheet 10a, 10b, 10A, 10Aa, 10Ax Hoop material 11a, 11b Support member 11aa, 11ba Gate portion 11ab, 11bb Runner portion 20 Magnetic member 50 DC-DC converter 51 Printed wiring board 52 Switching element 53 Input capacitor 54 Output capacitor 100 Base CL1, CL2 Clearance

Claims (18)

1. One end portions of a plurality of metal pins are exposed on a first surface of an element body that is a compact including magnetic particles, and the plurality of metals are exposed on a second surface of the element body facing the first surface. Preparing the element body in which the plurality of metal pins are embedded so that the other end of the pin is exposed;
   In the first surface of the element body, a plurality of the metals supported by the support member so as to electrically connect one end of one metal pin and one end of the other metal pin with a metal plate Placing a plate on the first surface of the element body;
   In the second surface of the element body, a plurality of the conductors are connected to the element body so that the other end part of one metal pin and the other end part of the other metal pin are electrically connected by a conductor. Placing on the second surface;
   Removing at least a part of the support member after the one end portions of the plurality of metal pins and the plurality of metal plates are electrically connected;
   Including
   A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
   Manufacturing method of coil parts.
2. The plurality of metal plates and the support member are made of a hoop material obtained by etching or punching a metal sheet,
   After the one end portions of the plurality of metal pins and the plurality of metal plates are electrically connected, the support member and the plurality of metal plates are separated, and at least a part of the support member is removed. The manufacturing method of the coil components of Claim 1.
3. The method for manufacturing a coil component according to claim 1 or 2, further comprising a step of forming a covering member so as to cover the first surface of the element body.
4. 4. The method of manufacturing a coil component according to claim 3, wherein the covering member is a covering body that is a molded body including magnetic particles.
5. The hoop material includes an electrode portion to be a terminal electrode of the coil component,
   The electrode part is located on the first surface side of the element body even after the support member is removed,
   5. The coil component manufacturing according to claim 3, wherein the covering member is formed so as to cover the first surface of the element body except for the electrode portion so that the electrode portion is exposed to the outside. Method.
6. The method for manufacturing a coil component according to claim 5, wherein the hoop material is bent so that the electrode portion is located on a plane away from a plane on which the plurality of metal plates and the support member are located.
7. A conductive bonding material is provided at one end of each of the plurality of metal pins exposed on the first surface of the element body, and the plurality of metal plates are bonded onto the conductive bonding material. The method for manufacturing a coil component according to any one of claims 1 to 6, further comprising disposing the support member on a first surface of an element body.
8. The element body has a magnetic member having a higher relative permeability than the element body in a region located between the plurality of metal pins and between the first surface and the second surface of the element body. The method for manufacturing a coil component according to any one of claims 1 to 7, wherein the coil component is embedded.
9. The method of manufacturing a coil component according to any one of claims 1 to 8, wherein the magnetic particles are magnetic metal powder, and the element body is a green compact including the magnetic metal powder.
10. 10. The method for manufacturing a coil component according to claim 1, wherein the magnetic particles include a composite magnetic material.
11. A plurality of the coil conductors are formed in the element body,
    The method of manufacturing a coil component according to any one of claims 1 to 9, further comprising a step of cutting the element body into pieces so as to form individual coil components including one coil conductor.
12. The conductor is a metal plate;
    The metal plate is electrically connected to the other end of the metal pin exposed on the second surface of the element body.
    The method for manufacturing a coil component according to any one of claims 1 to 10.
13. An element body that is a compact including magnetic particles;
    Plural embedded in the element body such that one end portion is exposed at the first surface of the element body and the other end portion is exposed at the second surface of the element body facing the first surface. With metal pins,
    A plurality of elements disposed on the first surface of the element body so as to electrically connect one end portion of one metal pin and one end portion of the other metal pin on the first surface of the element body. With a metal plate,
    The second surface of the element body is disposed on the second surface of the element body so as to electrically connect the other end of one metal pin and the other end of the other metal pin. A plurality of conductors,
    With
    A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
    A gap is provided between the plurality of metal plates and the first surface of the element body.
    Coil parts.
14. The coil component according to claim 13, wherein an average dimension of a gap between the metal plate and the first surface of the element body is larger than an average dimension of a gap between an outer peripheral surface of the metal pin and the element body.
15. The element body has a magnetic member having a higher relative permeability than the element body in a region located between the plurality of metal pins and between the first surface and the second surface of the element body. The coil component according to claim 13 or 14, which is embedded.
16. The coil component according to any one of claims 13 to 15, wherein the magnetic particles include a composite magnetic material.
17. A DC-DC converter comprising a switching element and a choke coil connected to the switching element,
    The choke coil is
    An element body that is a compact including magnetic particles;
    Plural embedded in the element body such that one end portion is exposed on the first surface of the element body and the other end portion is exposed on the second surface of the element body facing the first surface. With metal pins,
    A plurality of elements disposed on the first surface of the element body so as to electrically connect one end portion of one metal pin and one end portion of the other metal pin on the first surface of the element body. With a metal plate,
    The second surface of the element body is disposed on the second surface of the element body so as to electrically connect the other end of one metal pin and the other end of the other metal pin. A plurality of conductors,
    With
    A coil conductor is composed of the plurality of metal pins, the plurality of metal plates, and the plurality of conductors,
    A gap is provided between the plurality of metal plates and the first surface of the element body.
    DC-DC converter.
18. The DC-DC converter according to claim 17, wherein the magnetic particles include a composite magnetic material.

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