JP6409328B2 - Coil parts - Google Patents

Description

  The present invention relates to a coil component in which a coil is embedded in an element body.

  In general, as shown in Patent Document 1 below, in a coil component in which a coil is embedded in an element body, the end of a coated wire constituting the coil is exposed to the outside of the element body, and a bent portion is formed. The end portion of the wire is connected to the terminal electrode by removing the coating film of the bent portion and covering it with the terminal electrode.

  However, in such a coil component, it is difficult to align the bent portion (wire end portion), and even if the alignment is possible, the process of removing the coating at the end of the coated wire corresponding to the bent portion is complicated. It has the problem of being. The remaining film at the bent portion may lead to a decrease in bonding strength with the terminal electrode and deterioration of characteristics such as inductance. Further, in order to bend the end portion of the wire outside the element body to make the lead portion, it is necessary to reduce the diameter of the coil, which may cause deterioration of characteristics such as inductance.

JP 2010-147271 A

  The present invention has been made in view of such a situation, and the object thereof is that it is not necessary to align the lead end of the coated wire constituting the coil, and no coating removal process is required, and particularly the bonding strength with the terminal electrode. Is to provide high coil parts.

In order to achieve the above object, the coil component according to the present invention comprises:
An element body mainly composed of a synthetic resin or a magnetic material;
A wire with a coating embedded in the element body and wound in a coil;
A coil part formed on the outer surface of the element body and connected to a lead end of the coated wire,
The lead end of the coated wire is exposed on the outer cut surface of the element body as a cut surface of the coated wire, and the cut surface of the coated wire is covered with the terminal electrode. Features.

  In the coil component according to the present invention, when the element body is cut, the lead end of the coated wire is cut at the same time. Therefore, it is not necessary to align the lead end of the coated wire that constitutes the coil. Further, when the element body is cut, the lead end of the coated wire is also cut, so that the coating is also cut, and the wire core inside the coating is exposed. Therefore, it is possible to provide a coil component that does not require a coating removal step and that has a particularly high bonding strength with the terminal electrode.

  Preferably, the lead end of the coated wire has a cut surface that intersects at an acute angle with the extending direction of the lead end of the coated wire, and the cut surface is covered with the terminal electrode. By cutting the lead end of the coated wire at an acute angle with respect to the direction in which the lead end of the coated wire extends, the cut surface where the wire core wire inside the coated film is exposed becomes long, and the bonding strength with the terminal electrode is increased. Especially improved.

  Preferably, the cut surface of the coated wire is formed across two or more outer cut surfaces of the element body, and the cut surface of the coated wire is covered with the terminal electrode. By comprising in this way, the cut surface which the wire core wire inside a film exposes becomes long, and joining strength with a terminal electrode further improves.

  Preferably, in the cut surface of the coated wire, the outer periphery of the cut surface of the wire core wire is covered with the cut film. With this configuration, even if the metal magnetic powder is dispersed in the main component constituting the element body, the wire core wire and the metal magnetic powder of the element body are less likely to be short-circuited, and withstand voltage characteristics are improved. As well as improving, it also contributes to the prevention of inductance deterioration.

  Preferably, the coated wire is a rectangular wire having a rectangular cross section. By cutting the lead end of the flat wire obliquely simultaneously with the cutting of the element body, the exposed cut surface of the wire core wire is increased, and the bonding strength with the terminal electrode is improved.

  Preferably, the coated wire is wound edgewise inside the element body. Compared with the crosswise winding, the exposed cut surface at the lead end of the wire core wire can be easily enlarged without twisting the wire. Therefore, the bonding strength with the terminal electrode is improved.

FIG. 1A is a perspective view of a coil component according to an embodiment of the present invention. 1B is a partial cross-sectional perspective view of the coil component shown in FIG. FIG. 1C is a perspective view showing only the element body of the coil component shown in FIG. FIG. 1D is a plan view showing the cutting position of the lead end of the coated wire wound in the coil shape shown in FIG. FIG. 2 is a schematic perspective view showing an enlarged cut surface of the lead end of the coated wire wound in the coil shape shown in FIG. FIG. 3 is a schematic perspective view showing a manufacturing process of the coil component shown in FIG. FIG. 4 is a perspective view of an element body of a coil component according to another embodiment of the present invention.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment As shown in FIGS. 1A to 1B, a coil component 2 according to an embodiment of the present invention includes an element body 4 having a substantially rectangular parallelepiped shape. The vertical (X-axis), horizontal (Y-axis) and height (Z-axis) dimensions of the element body 4 are not particularly limited. For example, the vertical (X-axis) dimension of the element body 4 is preferably 1.4 to The horizontal (Y-axis) dimension is preferably 0.6 to 6.5 mm, and the height (Z-axis) dimension is preferably 0.5 to 5.0 mm. In the present embodiment, the effect is particularly great when these dimensions are small.

  Inside the element body 4, a wire 6 with an insulating coating (wire with coating) is embedded. The element body 4 has four side surfaces 4a to 4d and two end surfaces 4e and 4f that face each other in the X-axis direction. The coated wire 6 is wound in a coil shape in one or more turns inside the element body 4.

  In the present embodiment, the coated wire 6 is a flat wire made of a copper wire covered with a resin coating, for example. More specifically, the coating is an epoxy-modified acrylic resin. In the embodiment, the coated wire 6 constitutes an air-core coil in edgewise winding. Note that edgewise winding is a winding method in which the winding axis (Z-axis) is perpendicular to the plane of a flat wire.

  In this embodiment, the element body 4 in which the coated wire 6 is embedded is mainly composed of a synthetic resin in which ferrite particles or metal magnetic particles are dispersed. However, only the synthetic resin not containing these particles is used. It may be the main component. The element body 4 may be mainly composed of a magnetic material such as ferrite particles or metal magnetic particles.

  Although it does not specifically limit as metal magnetic body particle | grains, For example, Fe-Ni alloy powder, Fe-Si alloy powder, Fe-Si-Cr alloy powder, Fe-Co alloy powder, Fe-Si-Al alloy powder etc. are illustrated. The

  Although it does not specifically limit as a synthetic resin, Preferably, an epoxy resin, a phenol resin, a polyester resin, a polyurethane resin, a polyimide resin etc. are illustrated.

  In the present embodiment, in the element body 4 shown in FIG. 1C, the pair of end faces 4e, 4f facing in the X-axis direction and the pair of side faces 4c, 4d facing in the Y-axis direction are in the manufacturing process of the element body 4. The outer cut surface. The pair of side surfaces 4a and 4b facing the Z-axis direction in the element body 4 become mold forming surfaces when the element body 4 is compacted. Further, when the element body 4 is formed of a laminate of synthetic resin films, the side surfaces 4a and 4b correspond to the surface of the film.

  A pair of end faces 4e and 4f facing in the X-axis direction are covered with terminal electrodes 8a and 8b as shown in FIGS. 1A and 1B. Further, the side surfaces 4a to 4d close to these end surfaces 4e and 4f are also covered with the extension covering portion 8a1 of the terminal electrode 8a and the extension covering portion 8b1 of the terminal electrode 8b.

  The extension covering portion 8a1 of the terminal electrode 8a and the extension covering portion 8b1 of the terminal electrode 8b have a length in the X-axis direction so as to cover the first cut surfaces 6ac and 6bc at the lead ends 6a and 6b of the coated wire 6, respectively. The extension covering portion 8a1 and the extension covering portion 8b1 are set so as not to be short-circuited in the X-axis direction.

  The terminal electrodes 8a and 8b are formed of, for example, a laminated electrode film, and the base electrode film is formed of a conductive paste film containing a metal such as Sn, Ag, Ni, or C or an alloy thereof, and the base electrode film A plating film may be formed thereon. Examples of the plating film include metals such as Sn, Au, Ni, Pt, Ag, and Pd, or alloys thereof.

  In the present embodiment, as shown in FIG. 1C, the lead ends 6a and 6b of the coated wire 6 are extended to the corners of the side surface 4c and the end surface 4e and the corners of the side surface 4c and the end surface 4f. A wire 6 is wound around the main body 4. The lead end 6a is formed with a first cut surface 6ac that is formed simultaneously when the side surface 4c is formed by cutting, and a second cut surface 6ae that is formed simultaneously when the end surface 4e is formed by cutting. It is. The first cut surface 6ac and the second cut surface 6ae are exposed to the side surface 4c and the end surface 4e, respectively, before the terminal electrode 8a is formed.

  Further, the lead end 6b is formed with a first cut surface 6bc that is formed simultaneously when the side surface 4c is formed by cutting, and a second cut surface 6bf that is formed simultaneously when the end surface 4f is formed by cutting. It is. The first cut surface 6bc and the second cut surface 6bf are exposed to the side surface 4c and the end surface 4f, respectively, before the terminal electrode 8b is formed.

  As shown in FIG. 2, at the first cut surface 6ac and the second cut surface 6ae of the lead end 6a (same for 6b) of the coated wire 6, the outer periphery of the cut surface of the wire core wire 60 is covered with the cut film 62. It has been broken. As shown in FIG. 1D, the first cut surface 6ac and the second cut surface 6ae of the lead end 6a of the coated wire 6 are covered with a terminal electrode 8a having an extended covering portion 8a1, and are electrically connected and fixed thereto. Has been. The first cut surface 6bc and the second cut surface 6bf of the lead end 6b of the coated wire 6 are covered with a terminal electrode 8b having an extended covering portion 8b1, and are electrically connected and fixed thereto.

  Next, the manufacturing method of the coil component 2 of this embodiment is demonstrated. As shown in FIG. 3, in the method of this embodiment, first, a plurality of air-core coil-shaped wires 6 wound in a coil shape are prepared, and these are arranged in a matrix in the mold. And compacting. At the time of compacting, the molten synthetic resin in which the metal magnetic particles are dispersed is poured into a mold in which the coated wire 6 is previously disposed, and is cured by heat, for example.

  Thereafter, the assembly (preliminary molded body) 40 of the cured element body is taken out from the inside of the mold, the assembly is cut along the planned cutting line 20, and a single coating is formed inside as shown in FIG. 1C. The element body 4 in which the attached wire 6 is embedded is obtained. At the end surfaces 4e, 4f and 4c which are cut surfaces, the lead ends 6a and 6b of the coated wire 6 are cut and exposed as cut surfaces 6ac, 6ae, 6bc and 6bf.

  After that, if the terminal electrode 8a having the extension covering portion 8a1 and the terminal electrode 8b having the extension covering portion 8b1 are formed on the end faces 4e and 4f by the paste method and / or the plating method, FIG. 1A and FIG. 1B are obtained. The coil component 2 shown is obtained.

  In the present embodiment, the method for cutting the element body assembly 40 is not particularly limited, and a cutting tool such as a wire saw or a laser may be used. In this embodiment, when the element body assembly 40 is cut, the lead ends 6a and 6b of the coated wire 6 are also cut at the same time. Therefore, it is unnecessary to align the lead ends 6a and 6b of the coated wire 6 constituting the coil. Further, when the element body assembly 40 is cut, the lead ends 6a and 6b of the coated wire 6 are also cut, so that the coat 62 is also cut and the wire core wire 60 inside the coat is exposed. Therefore, it is possible to provide the coil component 2 that does not require a coating removal step and that has particularly high bonding strength with the terminal electrodes 8a and 8b.

  Furthermore, in this embodiment, the lead ends 6a and 6b of the coated wire 6 have cut surfaces 6ae and 6bf that intersect at an acute angle with respect to the direction in which the lead ends 6a and 6b of the coated wire 6 extend. Furthermore, the lead ends 6a and 6b of the respective coated wires 6 have cut surfaces 6ae and 6ac formed across two or more outer cut surfaces of the element body 4, and cut surfaces 6bf and 6bc. In this embodiment, by having such a structure, as shown in FIG. 2, the cut surface where the wire core wire 60 inside the coating 62 is exposed becomes long, and the bonding with the terminal electrodes 8a and 8b shown in FIG. 1A is performed. Strength is particularly improved.

  Further, as shown in FIG. 2, in the cut surface of the coated wire 6, the outer periphery of the cut surface of the wire core wire 60 is covered with the cut film 62, so that the main component constituting the element body 4 is made of metal magnetism. Even if the body powder is dispersed, the wire core 60 and the metal magnetic powder of the element body 4 are less likely to be short-circuited, improving the withstand voltage characteristics and contributing to the prevention of inductance deterioration.

  Furthermore, in this embodiment, since the coated wire 6 is a rectangular wire having a rectangular cross section, simultaneously with the cutting of the element body 4, by cutting the lead ends 6a and 6b of the rectangular wire obliquely, The exposed cut surface of the wire core wire 60 is increased, and the bonding strength with the terminal electrode is improved.

  Furthermore, in this embodiment, the coated wire 6 is wound edgewise inside the element body 4. Compared with the crosswise winding, the exposed cut surface at the lead end of the wire core wire 60 can be easily enlarged without twisting the wire 6. Therefore, the bonding strength with the terminal electrodes 8a and 8b is improved.

Second Embodiment As shown in FIG. 4, the coil device 2 according to the present embodiment is different from the first embodiment in the following parts, and the other parts are common, so the description of the common parts is omitted. . As shown in FIG. 4, a coil is formed by winding a coated wire 6 in an edgewise manner inside the element body 4. However, in the case of edgewise winding, twist portions 6aa and 6bb of 90 degrees are formed inside the element body 4 before the cut surfaces 6ac, 6ae, 6bc and 6bf of the lead ends 6a and 6b are formed. Preferably there is. By forming the twist portions 6aa, 6bb of 90 degrees, the shapes of the cut surfaces 6ac, 6ae, 6bc, 6bf, which are the connection portions with the terminal electrodes 8a, 8b, can be made the same as in the first embodiment. . Note that edgewise winding is a winding method in which the winding axis (Z axis) is parallel to the plane of a flat wire.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, in the above-described embodiment, the two cut surfaces 6ac and 6ae or 6bc and 6bf intersecting each other at a predetermined angle are formed on the lead ends 6a and 6b, but only one of the cut surfaces may be used. However, the cut surface 6ae or 6bf that is obliquely cut is preferable.

  Further, the coated wire is not limited to a flat wire, and may be other wires. In the above-described embodiment, the element body is formed by compacting, but the element body may be formed by other methods. For example, the element body may be formed by laminating a resin film in which metal magnetic particles are dispersed or another resin film.

  The wire winding method is not limited to the above-described embodiment, and the wire may be wound in a circular spiral shape, an elliptical spiral shape, a square spiral shape, or a concentric shape.

2 ... Coil parts 4 ... Element body 6 ... Wires 6a, 6b with coating ... Lead ends 6ac, 6ae, 6bc, 6bf ... Cutting surfaces 8a, 8b ... Terminal electrodes 20 ... Cutting lines 40 ... Aggregates

Claims (5)

An element body mainly composed of a synthetic resin or a magnetic material;
A wire with a coating embedded in the element body and wound in a coil;
A coil part formed on the outer surface of the element body and connected to a lead end of the coated wire,
The coated wire is a rectangular wire having a rectangular cross section,
A lead end of the coated wire is exposed to an outer cut surface of the element body as a cut surface of the coated wire, and the cut surfaces of the coated wire are cut at two or more outer cuts of the element body. A coil component formed over a surface and covered with the terminal electrode .   The lead end of the coated wire has a cut surface that intersects at an acute angle with the extending direction of the lead end of the coated wire, and the cut surface is covered with the terminal electrode. The coil component described. 3. The coil component according to claim 1, wherein an outer periphery of the cut surface of the wire core wire is covered with a cut film on the cut surface of the wire with the film. The coil component according to any one of claims 1 to 3, wherein the coated wire is edgewise wound inside the element body. 5. The coil component according to claim 1, wherein a lead end of the coated wire is cut obliquely with respect to a direction in which the coated wire extends.

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