WO2017115603A1

WO2017115603A1 - Surface mount inductor and method for manufacturing same

Info

Publication number: WO2017115603A1
Application number: PCT/JP2016/085625
Authority: WO
Inventors: 敬太宗内
Original assignee: 株式会社村田製作所
Priority date: 2015-12-28
Filing date: 2016-11-30
Publication date: 2017-07-06

Abstract

A surface mount inductor according to the present disclosure comprises: a resin molded body which contains a metal magnetic powder and has a quadrangular shape in a top view, and which has incision parts that are formed in at least two corner parts; at least one coil that is embedded in the resin molded body; and at least two external terminals that extend from the incision parts to the bottom surface of the resin molded body. Lead-out ends at both ends of the coil are respectively connected to the external terminals at the incision parts. Consequently, the present invention is capable of providing a surface mount inductor which is able to be mounted at high density on an electronic device, and which is able to be easily provided with an external terminal.

Description

Surface mount inductor and manufacturing method thereof

The present disclosure relates to a surface-mount inductor and a method for manufacturing the same, and more particularly to a surface-mount inductor in which at least one coil is embedded in a resin molded body containing metal magnetic powder and a method for manufacturing the same.

A conventional surface-mount inductor is a surface-mount inductor in which a coil formed by winding a conductive wire in a resin molded body containing metal magnetic powder is embedded, with the coiled end exposed to the end surface of the resin molded body. In some cases, an external terminal is formed across four surfaces adjacent to the end face and the end face of the resin molded body, and the external terminal and the coil are connected (for example, Patent Document 1). Along with the downsizing of electronic devices on which surface-mount inductors are mounted, the distance between the mounting substrate and its upper substrate, shield case, and the like, and the distance between other electronic components mounted adjacent to each other have become smaller. For this reason, the terminals formed on the upper substrate or shield case and the upper surface of the surface mount inductor come into contact with each other, short-circuit between the upper substrate or shield case, or the terminals of adjacent electronic components come into contact with each other. There is a possibility that a short circuit occurs between the two.

In order to solve such problems, it has been studied to form external terminals only on the bottom surface of the resin molded body. For example, in Patent Document 2, as shown in FIGS. 7A and 7B, a coil 61 is formed by winding a conductive wire, and the coil 61 is formed in a molded body 62 formed of a sealing material containing magnetic powder and resin. And the lead-out ends 64 a and 64 b of the coil 61 are drawn out to the bottom surface of the molded body 62, and the lead-out end of the coil 61 is used as the external terminal 64, or a conductive paste is connected to the lead-out end of the coil 61. The external terminal 64 is described.

JP 2010-245473 A JP 2010-177492 A

However, a surface mount inductor having a structure in which the coil drawing end is drawn out to the bottom surface of the molded body has a problem that the structure of the coil drawing end is complicated. In addition, in the case of miniaturization, there is a problem that it is difficult to process the drawing end portion of the coil and draw it to a predetermined position on the bottom surface of the molded body. In addition, it is difficult to form the conductive paste only on the bottom surface of the molded body, and it is difficult to stably form the external terminals.

Further, as the surface mount inductor having the external terminals only on the bottom surface of the resin molded body, for example, the one shown in the schematic longitudinal sectional view of FIG. That is, a coil formed by winding a conducting wire is built in the resin molded body 71, and the drawn end portion of the coil is exposed on the side surface of the resin molded body. A pair of

external terminal electrodes

74a and 74b, so-called five-face electrodes, are formed by using a plating process or a conductive paste over the side face and four faces adjacent to the side face. Then, it is conceivable that the resin molded body 71 on which the external terminal electrode 74 is formed is covered with an insulating resin 75 other than the bottom surface, and only the bottom surface of the external terminal electrode 74 is used as an external terminal. However, such a surface mount inductor requires an insulating resin to insulate the resin molded body on which the electrode for the external terminal is formed, and the high density mounting is limited by the thickness, and the cost is correspondingly reduced. Rises. Further, it is possible that the volume of the resin molded body is reduced by the thickness of the external terminal electrode and the insulating resin formed on the portion other than the bottom surface of the resin molded body, and the characteristics may be deteriorated.

Therefore, there is still a need for a surface-mount inductor that can sufficiently cope with further downsizing of electronic equipment, can be mounted with high density, and can easily form external terminals, and a manufacturing method thereof.

Therefore, an object of the present disclosure is to provide a surface-mount inductor that can be mounted on an electronic device at a high density and that can easily form an external terminal, and a manufacturing method thereof.

In order to solve the above problem, a surface-mount inductor according to one aspect of the present disclosure is a resin molded body that includes a metal magnetic powder and has a quadrangular shape in a top view, and is formed at at least two corners. The resin molded body having a notch, at least one coil embedded in the resin molded body, and at least two external terminals extending from the notch to the bottom surface of the resin molded body. The lead-out ends of the lead-out ends at both ends of the coil are connected to the external terminals at the notches.

Another aspect of the present disclosure is a method for manufacturing a surface-mount inductor in which at least one coil is embedded in a resin molded body containing metal magnetic powder, and the coil is disposed in a molding die. The resin molded body having a rectangular shape in a top view and having notches formed in at least two corners by filling the molding die with the material for the resin molded body and molding the material. A part of each drawing end of each of the ends of the coil forming the resin molded body exposed or close to the notch, and extending from the notch to the bottom surface. Forming an external terminal.

According to the surface-mount inductor of the present disclosure, it is possible to provide a surface-mount inductor that can be mounted on an electronic device at a high density and that can easily form an external terminal.

FIG. 3 is a schematic transparent perspective view showing the inside of the surface-mount inductor according to the first embodiment of the present disclosure. FIG. 2 is a schematic perspective view of an upper surface side of the surface mount inductor of FIG. 1. FIG. 2 is a schematic perspective view of a bottom surface side of the surface mount inductor of FIG. 1. FIG. 2 is a schematic top perspective view of the surface mount inductor of FIG. 1 before forming a plating layer. FIG. 2 is a schematic perspective view of the bottom surface side of the surface mount inductor of FIG. 1 before forming a plating layer. It is a schematic cross section which shows the manufacturing process of the external terminal of the surface mount inductor of FIG. It is a schematic cross section which shows the manufacturing process of the external terminal of the surface mount inductor of FIG. It is a schematic cross section which shows the manufacturing process of the external terminal of the surface mount inductor of FIG. It is a coil exposure model top view of a surface mount inductor concerning Embodiment 2 of this indication. It is a coil exposure model top view of a surface mount inductor concerning Embodiment 3 of this indication. It is an upper surface side model transparent perspective view which shows the inside of the conventional surface mount inductor. It is a bottom perspective schematic perspective view of a conventional surface mount inductor. It is a model longitudinal cross-sectional view of another conventional surface mount inductor.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings and the like. In addition, in the following drawings, when using the same member, the same code | symbol may be attached | subjected and the overlapping description may be abbreviate | omitted or simplified.

Embodiment 1
The surface-mount inductor according to the present embodiment is a resin molded body that includes a metal magnetic powder and has a quadrangular shape in a top view, and the resin molded body that has cutout portions formed in at least two corners. And at least one coil embedded in the resin molded body, and at least two external terminals extending from the notch to the bottom surface of the resin molded body, and leading end portions at both ends of the coil Each of the lead-out end portions is connected to the external terminal at the cutout portion.

FIG. 1 is a schematic transparent perspective view showing the inside of a surface-mount inductor A according to the present embodiment. The surface-mount inductor A has a resin molded body 12 containing metal magnetic powder, and one coil 11 around which a conducting wire is wound is embedded therein. The resin molded body 12 has a quadrangular shape when viewed from above. In FIG. 1, the example of the rectangular body which has the upper surface 12c and the bottom face 12d which oppose is shown. Two adjacent corners out of the four corners of the quadrilateral shape have

notches

12a and 12b. The coil 11 has a so-called “outer / outer winding” winding portion 11a in which a conductive wire is wound so that both ends thereof are positioned in opposite directions along the outer peripheral surface of the coil, and both ends of the winding portion 11a. It is a coil provided with a pair of drawer | drawing-out

edge parts

11b and 11b which consist of the non-winding part provided. Here, FIG. 1 shows an example of two-stage outer and outer windings. In addition, a rectangular wire having a rectangular cross section can be used as the conducting wire. In addition, as a shape of a coil, circular shape, ellipse shape, or substantially rectangular shape can be mentioned by top view. Further, one of the drawer end portions 11b extends in the resin molded body 12 and is bent so that a part thereof is exposed at the notch portion 12a. The other drawer end portion 11b is also formed of the resin molded body. 12 is bent so that a part thereof is exposed at the notch 12b. In addition, as a shape of the resin molding in this indication, rectangular shape, for example, a rectangular parallelepiped and a cube, are included.

As the cutout surfaces of the

cutout portions

12a and 12b, a rectangular flat cutout surface perpendicular to the top surface and the bottom surface can be used, but a quadrangular shape inclined at an acute angle toward the top surface or the bottom surface as necessary. Notched surfaces can also be used. Furthermore, it is preferable that the angle between the notch surface and the adjacent side surface is not less than 135 degrees and not more than 150 degrees.

The lead-out

end portions

11b and 11b are exposed at the cutout surfaces of the

cutout portions

12a and 12b, but the exposed area is not particularly limited as long as electrical connection with an external terminal is possible. Further, as will be described later, the lead-out end portion may protrude from the cutout surface to the extent that the formation of the plating layer formed thereon is not hindered.

The resin molded body 12 has

notches

12a and 12b in which at least two of the four corners are linearly cut between the two surfaces constituting the corners when viewed from above. It is formed to have The notch 12a and the notch 12b are formed at adjacent corners. That is, it is symmetrical with respect to a center line extending in the width direction of the upper surface 12c of the resin molded body 12, that is, a center line X perpendicular to the center line Y in the length direction connecting both ends of the conducting wire. Furthermore, the

notches

12a and 12b are formed from notch surfaces. It is preferable that the angle between the cut surface and the side surface of the resin molded body 12 is 135 degrees or more and 150 degrees or less.

The resin molded body contains metal magnetic powder, a binder resin, and additives such as a moldability improver and a release agent as necessary. Examples of the metal magnetic powder include iron-based metal magnetic powders such as Fe, Fe-Si-Cr, Fe-Si-Al, Fe-Ni-Al, and Fe-Cr-Al, and metal magnetism such as amorphous. Examples thereof include body powder, metal magnetic powder whose surface is coated with an insulator such as glass, and metal magnetic powder whose surface is modified. In addition, examples of the binder resin include thermosetting resins such as epoxy resins, polyimide resins, and phenol resins, and thermoplastic resins such as polyethylene resins and polyamide resins.

2A is a schematic perspective view of the top surface side of the surface mount inductor A, and FIG. 2B is a schematic perspective view of the bottom surface side of the surface mount inductor A. The surface mount inductor A has a first external terminal 14a extending from the notch 12a of the resin molded body 12 to the bottom surface 12d, and a second external terminal 14b extending from the notch 12b to the bottom surface 12d. . That is, the pair of

external terminals

14a and 14b are formed in an L shape from the portion where the coil drawing

end portions

11b and 11b of the

cutout portions

12a and 12b of the resin molded body 12 are located toward the bottom surface 12d of the resin molded body 12. It extends and is not exposed on any side surface of the resin molded body 12 at the bottom surface 12 d of the resin molded body 12. The external terminal 14 is not particularly limited as long as it is a conductive material extending from the

notches

12a and 12b to the bottom surface 12d. For example, plating formed on the surface of the exposed portion of the metal magnetic powder where the metal magnetic powder is exposed. It may be a layer. A metal material such as Cu, Ni, or Sn can be used for the plating layer.

The surface mount inductor according to the present embodiment can be manufactured using, for example, the following manufacturing method. That is, a method for manufacturing a surface-mount inductor in which at least one coil is embedded in a resin molded body containing metal magnetic powder, the coil being placed in a molding die, and a resin molded body material The resin molded body having a quadrangular shape in a top view and having notches formed in at least two corners by being filled in the molding die and formed at both ends of the coil Forming the resin molded body in which a part of each drawer end is exposed or close to the notch, and forming an external terminal extending from the notch to the bottom surface; Have Hereinafter, a description will be given with reference to FIGS. 1 to 4C.

First, a molding process for forming a resin molded body will be described. A winding wire 11a shown in FIG. 1 is formed by winding a conductive wire having a rectangular cross-section with an insulating coating in a spiral shape so that both ends thereof are located on the opposite side along the outer periphery. To do. Next, both ends of the conducting wire are pulled out from the outer periphery of the winding portion to form the

leading end portions

11b and 11b to form the coil 11. The resin used for the insulating coating preferably has a high heat resistance temperature, and examples thereof include polyamide resins, polyester resins, and imide-modified polyurethane resins. As the conducting wire, a round wire or one having a polygonal cross section may be used.

Next, as magnetic materials, for example, iron-based metal magnetic powders such as Fe, Fe—Si—Cr, Fe—Si—Al, Fe—Ni—Al, Fe—Cr—Al, and amorphous metal magnetic materials For example, an epoxy resin is used as a binder resin, and these are mixed to produce a sealing material (resin molded body material). Next, the coil 11 is placed in a predetermined molding die, and a resin molding material is filled in the die and compression molded. As a result, as shown in FIG. 1, the resin molded body 12 is obtained in which the coil 11 is embedded and at least two of the four corners when viewed from above are provided with notches. Note that the lead-out

end portions

11b and 11b of the coil 11 are exposed or close to the

notch portions

12a and 12b of the resin molded body 12 by being exposed or close to the notch forming surface in the molding die. Thus, the

drawer end portions

11b and 11b at both ends can be arranged. Further, the molding method is not limited to the compression molding method, and a powder molding method can also be used.

Next, a process for forming an external terminal extending from the notch to the bottom surface will be described. 3A is a schematic perspective view of the upper surface side of the surface mount inductor of FIG. 1 before forming a plating layer. FIG. 3B is a schematic perspective view of the bottom surface side of the surface mount inductor of FIG. 1 before forming a plating layer. The resin component present on the surface of the portion of the resin molded body 12 where the

notches

12a and 12b and the external terminals of the bottom surface 12d are formed is removed using a resin component removing means such as laser irradiation, blasting, and polishing. As a result, the first metal magnetic body powder exposed portion 13a and the second metal magnetic body powder exposed where the metal magnetic body powder constituting the resin molded body 12 is exposed at the

notches

12a and 12b and the bottom surface 12d of the resin molded body 12. A metal magnetic powder exposed portion 13 having a portion 13b is formed. The metal magnetic powder exposed portion 13 extends from the portion where the lead-out ends 11b and 11b at both ends of the

notches

12a and 12b of the resin molded body 12 are located toward the bottom surface 12d of the resin molded body 12, It is formed so as not to be exposed on any side surface of the body 12. In addition, the lead-out

end portions

11b and 11b at both ends of the coil 11 are also exposed by removing the insulating coating using the resin component removing means.

Further, the resin molded body 12 is subjected to a plating process to form a plating layer to be bonded to the metal magnetic powder on the

notches

12a and 12b and the bottom surface 12d of the resin molded body 12 as shown in FIGS. 2A and 2B. Thus, the external terminal 14 including the first external terminal 14a and the second external terminal 14b is formed. Thereby, the external terminal 14 is connected to the leading end portions of the

leading end portions

11 b and 11 b at both ends exposed on the surface of the resin molded body 12. The conductive material is not particularly limited as long as it is a metal that can be plated. For example, a material containing at least one metal material selected from the group consisting of Cu, Ni, and Sn can be used.

Here, the structure of the external terminal will be described with reference to FIGS. 4A to 4C. FIG. 4A is, for example, a partial longitudinal sectional view of the first metal magnetic substance powder exposure portion 13a in FIG. 3B and shows a state before the metal magnetic substance powder is exposed. In the surface mount inductor before the external terminal is formed, the resin molded body contains the metal magnetic powder. Therefore, as shown in FIG. 4A, the surface is covered with the binder resin 15 and the metal magnetic powder 16 is mixed inside. It has become a state. Here, by removing the resin component present on the surface of the portion where the external terminal of the resin molded body is formed using laser irradiation, blasting, polishing, etc., as shown in FIG. 4B, the external terminal of the molded body The metal magnetic powder 16 is exposed in the portion where the metal magnetic powder is to be formed to form the metal magnetic powder exposed portion 13a. By plating the resin molded body in this state, as shown in FIG. 4C, a plating layer 18 is formed in the portion where the external terminals of the resin molded body are formed. Since the metal magnetic powder 16 has metallic properties, by applying a plating process to the resin molded body, a portion of the surface of the resin molded body where the metal magnetic powder is exposed is intensively energized, so that the plated metal is A plating layer is formed on the portion where the metal magnetic powder is deposited and exposed on the surface of the resin molded body. Although FIG. 4C shows an example in which the plating layer 18 is formed of two layers of the first plating layer 18a and the second plating layer 18b, it may be one layer or three or more layers.

According to the present embodiment, at least two corners of the four corners when viewed from the top surface of the resin molded body are formed with notches that are notched at the corners. A plating layer extending from the portion where the coil drawing end portion is located toward the bottom surface of the resin molded body and extending to the bottom surface of the resin molded body is bonded to the metal magnetic powder. Is formed. Thereby, the plating layer of the notch is positioned on the inner side of the side surface of the resin molded body, and the contact between the plating layer and another electronic component mounted adjacent to each other can be prevented. Thereby, an inductor can be mounted in an electronic device with higher density. Further, unlike the prior art, it is not necessary to pull out the leading end portion to the bottom surface of the resin molded body, so that the external terminal can be easily formed. Furthermore, by removing the resin only in the portion where the plating layer is formed on the surface of the notched portion of the resin molded body, and exposing the metal magnetic body powder contained in the resin molded body only in that portion, the periphery thereof is exposed. In comparison, it is possible to easily grow the plating layer in this portion, and it is possible to maintain the insulating properties other than the portion where the plating layer is formed. Further, by performing plating on the exposed portion of the metal magnetic powder, the thickness of the external terminal, which was conventionally about 40 to 100 μm, can be reduced to 20 μm or less. Thereby, it has the effect that the magnitude | size of the resin molding can be enlarged correspondingly and the whole shape can be made small. Further, when the molded body is enlarged by the amount that the external terminal can be thinned, the conducting wire can be thickened or the coil can be enlarged. Furthermore, when removing the resin on the surface of the resin molded body, there is an effect that the shape of the external terminal can be finely formed by using a laser.

In the present embodiment, the method of exposing the surface of the leading end portion of the leading end portion of the coil and performing the plating process directly on the exposed portion has been described. After applying a bonding material such as a conductive paste containing a conductor such as Cu so as to cover the drawn end of the coil, a plating process may be performed. In this case, the bonding strength of the lead-out end portion of the coil and the external terminal can be improved by this bonding material.

Further, in the present embodiment, the method of exposing the tip end portion of the coil drawing end portion to the cutout portion and connecting the tip end portion to the external terminal has been described. However, the coil drawing end portion is pulled out from the cutout portion. Then, the drawn tip is bent so as to be in contact with the notch, and a bent portion is formed. With the bent end fixed to the resin molded body, the insulating coating of the bent portion is removed and plating is performed. External terminals can also be formed by processing. Furthermore, in this case, an external terminal may be formed by applying a bonding material such as a conductive paste and plating the resin molded body so as to cover the bent portion. According to this method, the bonding area can be increased by performing the plating process on the bent portion, and the bonding strength can be improved. In addition, it is more permissible for the arrangement of the drawer end when the resin molded body is manufactured than in the case where the tip of the coil is not exposed from the surface of the notch so that the tip of the coil does not protrude from the surface of the notch. Since the degree is large, an effect of facilitating the production of the resin molded body can be obtained.

Further, in the present embodiment, the example in which the notch portion of the resin molded body is formed symmetrically with respect to the center line extending in the width direction of the upper surface of the resin molded body has been described, but it extends in the length direction. It may be formed symmetrically with respect to the existing center line, or may be symmetrical with respect to the center point of the upper surface of the molded body. That is, in the surface mount inductor according to the present embodiment, as shown in FIG. 1, the two notches are center lines extending in the width direction of the upper surface 12 c of the resin molded body 12, that is, both end portions of the conducting wire. It is formed symmetrically with respect to a center line X orthogonal to the center line Y in the connecting length direction. On the other hand, the two notches are formed in line symmetry with respect to the center line extending in the length direction, that is, in line symmetry with respect to the center line Y in the length direction connecting both ends of the conducting wire. It may be formed. Also in this case, the two notches have an adjacent relationship. Further, it is formed point-symmetrically with respect to the center point on the upper surface of the molded body, that is, two notches are formed at point-symmetrical positions, that is, diagonal positions with the intersection of the center line X and the center line Y as the center of symmetry. May be formed. This case also has the same effect as the present embodiment.

Embodiment 2
The surface-mount inductor B according to the present embodiment has the same structure as the surface-mount inductor according to the first embodiment, except that notches are formed at the four corner front portions of the resin molded body. Although described with reference to FIG. 5, description of portions common to the surface mount inductor of the first embodiment is omitted.

FIG. 5 is a schematic top view of the coil exposure of the surface mount inductor B according to the present embodiment.

Cutout portions

52a, 52b, 52c, and 52d are formed at four corners of the resin molded body 52, respectively. The coil 51 embedded in the resin molded body 52 has a winding part 51a and lead-out

end parts

51b and 51b. Each of the

leading end portions

51b, 51b at both ends extends so that the tip portion is exposed or close to the notch portion. The four notches can be formed by using a predetermined molding die that can be provided with the four notches.

According to the present embodiment, by forming a notch at all four corners, further preventing contact with other electronic components mounted adjacent to each other, it is possible to increase the inductor in the electronic device. Can be mounted with density.

Embodiment 3
The surface-mount inductor C according to the present embodiment forms notches at all four corners of the resin molded body, and 2 in the rectangular resin molded body along the length direction of the resin molded body. It has a structure in which two coils are embedded. Although description will be given with reference to FIG. 6, description of portions common to the surface mount inductor of the first embodiment will be omitted.

FIG. 6 is a schematic top view of the coil exposure of the surface mount inductor C according to the present embodiment.

Notches

53a, 53b, 53c, and 53d are formed at four corners of the resin molded body 53, respectively. Two coils 51, 51 are embedded in the resin molded body 53, and the leading end portions of the drawing

end portions

51b, 51b of one coil 51 located on the lower side in the drawing are notched

portions

53a, 53b. The leading ends of the leading ends 51b and 51b of the other coil 51 at the upper side in the drawing are exposed or close at the

notches

53c and 53d. So as to extend.

According to the present embodiment, even when two coils are embedded in a resin molded body, the coil lead-out end portions are connected to the cutout portions formed at the four corner portions, so that they are mounted adjacent to each other. It is possible to prevent contact with the electronic component, and it is possible to mount the inductor on the electronic device with higher density.

DESCRIPTION OF SYMBOLS 11 Coil 11a Winding part 11b Pull-out end part 12 Resin molded object

12a Notch part

12b Notch part

12c Upper surface

12d Bottom surface 13 Metal magnetic body powder exposure part 13a 1st metal magnetic body powder exposure part 13b 2nd metal magnetic body powder exposure Part 14 External terminal 14a First external terminal 14b Second external terminal 15 Resin 16 Metal magnetic powder 18 Plating layer 18a First plating layer 18b Second plating layer 51 Coil 51a Winding part 51b Drawer end part 52 Resin molded

body

52a, 52b, 52c, 52d Notch 53

Resin molding

53a, 53b, 53c, 53d Notch

Claims

A resin molded body containing a metal magnetic powder and having a quadrangular shape in a top view, the resin molded body having notches formed in at least two corners;
At least one coil embedded in the resin molded body;
Having at least two external terminals extending from the notch to the bottom surface of the resin molded body,
A surface-mount inductor, wherein each lead-out end of each lead-out end of the coil is connected to the external terminal at the notch.
2. The surface mount inductor according to claim 1, wherein the external terminal is formed of a plating layer formed on a surface of the exposed portion of the metal magnetic powder that extends from the notch to the bottom surface and exposes the metal magnetic powder.
The surface mount inductor according to claim 1 or 2, wherein the notch is formed at two adjacent corners.
The surface-mount inductor according to claim 1 or 2, wherein the notch is formed at two corners at diagonal positions.
5. The device according to claim 1, wherein a bent portion is formed by bending the drawer end portion pulled out from the cutout portion so as to contact the cutout portion, and the bent portion and the external terminal are connected. 2. The surface mount inductor according to item 1.
A method of manufacturing a surface-mount inductor in which at least one coil is embedded in a resin molded body containing metal magnetic powder,
The coil is placed in a molding die, and a resin molding material is filled in the molding die and molded, so that it has a quadrangular shape in top view and is formed at least at two corners. A molding step of forming the resin molded body, wherein the resin molded body has a notch portion, and a part of each of the drawing end portions at both ends of the coil is exposed or close to the notch portion;
Forming an external terminal extending from the notch to the bottom surface.
Forming the external terminal comprises:
Forming a metal magnetic powder exposed portion extending from the notch to the bottom surface and exposing the metal magnetic powder; and
Forming a plating layer on the surface of the exposed portion of the metal magnetic powder.
The manufacturing method according to claim 7, wherein the step of forming the exposed portion of the metal magnetic powder includes removing the resin on the surface by laser irradiation.