WO2021187049A1

WO2021187049A1 - Coil device

Info

Publication number: WO2021187049A1
Application number: PCT/JP2021/007272
Authority: WO
Inventors: 弘文仲澤
Original assignee: ソニーグループ株式会社
Priority date: 2020-03-19
Filing date: 2021-02-26
Publication date: 2021-09-23
Also published as: CN115280440A; JPWO2021187049A1

Abstract

Provided is a coil device comprising: a magnetic core; a plurality of coil wound bodies wound onto the magnetic core such that surfaces forming the long side of a cross-section of a flat wire are stacked; a base stand part that supports the magnetic core having the coil wound bodies; and connection terminals that are provided on the base stand part and that respectively connect to end parts of the coil wound bodies. The connection terminals include plate-shaped electrodes that sandwich surfaces of the end parts led out from the coil wound bodies.

Description

Coil device

This technology relates to a coil device that is mounted on a power supply unit or the like and is mainly applied to a common mode coil or a choke coil used for EMC (Electro-Magnetic Compatibility) countermeasures.

For example, with the increase in size of television receivers and the increase in brightness of projectors, coil devices are also required to support higher power consumption. For example, Patent Document 1 describes an invention relating to a common choke coil. This common choke coil eliminates common mode noise. In the common choke coil, for example, two conducting wires are wound around a toroidal core to form two coils. The winding directions of the coils are opposite to each other, and when a common mode current flows through the coil, magnetic fluxes are generated in the same direction, and the magnetic fluxes strengthen each other to block the passage of the common mode current, thereby blocking the inductor. Functions as. On the other hand, when a current in the differential mode flows through the coil, the directions of the generated magnetic fluxes are opposite, and the magnetic fluxes cancel each other out, so that the current in the differential mode flows smoothly. In this way, the filter does not function as an inductor for the current in the differential mode, but acts as an inductor only in the common mode. In the invention described in Patent Document 1, the coil device is vertically placed in order to reduce the installation space of the coil device on the substrate. In this case, the configuration of the coil and the connection terminal is devised.

JP-A-2019-165219

The problems in increasing the power by the structure and coil method of the common mode coil as described in Patent Document 1 are as follows.
・ The loss of the conductor (coil) increases as the amount of current increases. ・ The filter performance deteriorates due to the decrease in the maximum number of turns due to the increase in the conductor diameter.

The conductor loss is derived by the following equation.
Conductor loss (W) = I ² x R
I (A): Effective current value, R (Ω): Conductor resistance value

If the area where heat can be dissipated is constant based on this formula, the heat generated by the conductor (coil) increases as the loss increases. In other words, in order to increase the power, the resistance value of the conductor (coil) should be reduced. At the same time, facilitation of forming a substrate bonding (lead) portion with an increase in the cross-sectional area of the conductor becomes a very important issue. However, in Patent Document 1, after winding a flat wire around an integrally shaped iron core (including a case), it is necessary to always form a wafer bonding portion at the winding start portion by some method, which is easy. There is no description on how to solve it.

Therefore, the purpose of this technology is to provide a coil device that can easily cope with high power consumption.

This technology uses magnetic core and
A plurality of coil winding bodies wound around a magnetic core so that the surfaces forming the long sides of the cross section of the flat wire are laminated.
A base that supports a magnetic core with a coil winding body, and
It is provided on the base and has a connection terminal to be connected to the end of the coil winding body.
This is a coil device in which a connection terminal has a plate-shaped electrode that sandwiches an end surface derived from a coil winding body.

FIG. 1 is an external perspective view of a conventional common mode coil. FIG. 2 is an exploded perspective view of a conventional common mode coil. FIG. 3 is a perspective view of an embodiment of the present technology. FIG. 4 is an exploded perspective view of an embodiment of the present technology. FIG. 5 is a perspective view of a modified example of the embodiment of the present technology. FIG. 6 is an exploded perspective view of a modified example of the embodiment of the present technology. FIG. 7 is a partial perspective view of a modified example of the embodiment of the present technology. FIG. 8 is a perspective view for explaining a process of winding an electric wire. FIG. 9 is a perspective view for explaining the assembly process. FIG. 10 is a perspective view of the coil device after assembly. FIG. 11 is a front view of the coil device. FIG. 12 is an enlarged perspective view of a part of FIG. 10. FIG. 13 is an enlarged perspective view of a part of FIG. 10. FIG. 14 is a perspective view used for explaining a modified example of the connection terminal. FIG. 15 is an enlarged perspective view used for explaining a modified example of the connection terminal. FIG. 16 is an enlarged perspective view used for explaining a modified example of the connection terminal. FIG. 17 is a partial perspective view of another embodiment of the present technology. FIG. 18 is a schematic diagram used for explaining the bending process of the winding start end portion.

Hereinafter, embodiments of the present technology will be described with reference to the drawings. The embodiments described below are suitable specific examples of the present technology, and the contents of the present technology are not limited to these embodiments.

Prior to the explanation of this technology, the conventional toroidal type common mode coil will be described. FIG. 1 is an external perspective view of a conventional common mode coil, and FIG. 2 is an exploded perspective view thereof. A ring-shaped magnetic core 1 made of a magnetic material (iron core) having a main composition of Mn—Zn ferrite, iron amorphous, or the like is incorporated into a resin lower case 2 and a resin upper case 3.

An electric wire is wound around the lower case 2 and the upper case 3 in which the ring-shaped magnetic core 1 is incorporated, and the coil winding body 4a and the coil winding body 4b are formed. The

coil winding bodies

4a and 4b are provided by winding an electric wire having various insulating films on the surface, which is generally called an enamel electric wire and has a circular conductor cross-sectional shape. The lower case 2 and the upper case 3 provided with the

coil winding bodies

4a and 4b are incorporated into the resin pedestal 5.

As shown in FIG. 1, the position of the lead portion joined to the substrate by inserting the winding start terminal and the winding end terminal of the coil winding body 4a into the four holes 6 formed in the pedestal 5. Has a fixed structure. For the enamel wires used for the

coil winding bodies

4a and 4b, the conductor diameter and number of turns of the wires can be easily selected according to the required electrical characteristics of the coil, the applied current value, the operating temperature environment, etc. It is said to be adjustable.

When increasing the power by the structure and winding method of the common mode coil having such a structure, it is very important to reduce the resistance value of the conductor portion (coil winding body) as described above. Two methods can be taken to reduce the resistance value of the conductor portion. The first method is a method of reducing the resistance value by reducing the number of turns and shortening the total length of the conductor. However, in this method, the inductance value is lowered at the same time, which means that the electromagnetic filter performance of the common mode coil is lowered, and the loss reduction and the filter performance are in a trade-off relationship.

The second method is to reduce the resistance value by increasing the diameter of the electric wire and increasing the conductor area. However, as the electric wire diameter increases, the coil winding space occupancy rate decreases, which is specified. Since the number of turns cannot be rotated, the relationship is the same as that of the first method as a result. In terms of productivity, as the wire diameter increases, the bending strength of the wire becomes higher (difficult to bend), which makes the work itself extremely hard work, which significantly deteriorates productivity, and in recent years it has become extremely difficult to secure workers. There is a concern that the cost of parts will rise due to the fact that it has been increasing.

Therefore, an edgewise coil winding body using a flat wire that does not cause an extreme decrease in space factor even if the conductor area is expanded is used. Proposals have been made. Edgewise winding is a winding method in which the edge side (short side side of the cross section) of the flat wire is wound in a direction in which it is difficult to bend, and the surfaces forming the long side side thereof are laminated.

In terms of quality, the various insulating film layers (thickness) added to the flat wire are very thin, and according to JIS C3215-01: 2014, the minimum thickness is 0.06 mm to the maximum of 0.17 mm. When this flat wire is wound with an edgewise coil, the insulating film layer (thickness) inside the center of the long side of the flat wire (inner diameter of the coil winding body) shrinks, and the outer diameter (outer diameter of the coil winding body) is It will be a growing situation. If it is forcibly stretched from this state, it can be easily imagined that the damage to the already stretched insulating film layer (thickness) will increase and the insulation performance will deteriorate, resulting in long-term component reliability (life). May affect.

For example, in an edgewise coil winding body for low power, the current applied to the coil winding body is small and it is not necessary to increase the conductor cross-sectional area. Stay in. Therefore, the terminal pin entanglement / solder joining method, which is a general joining method, can be used for both ends of the coil winding body. On the other hand, for high power, the conductor cross-sectional area is expanded to reduce the conductor resistance value in order to reduce the loss, so the bending strength also increases and the terminal pin entanglement explained for low current is used. The solder bonding method cannot be used. Therefore, it is not possible to perform the substrate bonding portion forming work in consideration of long-term reliability (life) by simply winding the flat wire edgewise, and it is not possible to improve the work process.

One embodiment of the present technology solves the above-mentioned problems of the conventional coil winding device. FIG. 3 is an external perspective view of an embodiment of the present technology, and FIG. 4 is an exploded perspective view thereof. The two perspective views of FIG. 3 are perspective views viewed from different directions. The magnetic core 11 in one embodiment is a frame type composed of four sides, and a first coil winding body 13a and a second coil winding body 13b are provided on the left side 12a and the right side 12b, respectively. The magnetic core 11 is an integrally shaped magnetic core having no portion such as a division or a notch, and its surface is insulatingly coated.

The

coil winding bodies

13a and 13b are flat (copper) wires having various enamel insulating (coating) layers such as polyurethane. The coil winding body 13a is formed by winding an electric wire from the side of the upper side 12c toward the lower side 12d with respect to the left side 12a of the magnetic core 11 by a winding device. The coil winding body 13b is formed by winding an electric wire from the side of the upper side 12c toward the lower side 12d with respect to the right side 12b of the magnetic core 11 by a winding device. The electric wire is a flat wire having a rectangular cross section, and is wound (that is, edgewise wound) so that the surfaces forming the long sides of the cross section are laminated. In order to cope with high power, the thickness (short side) of the conductor of the flat wire is 0.4 mm or more, and the width (long side) of the flat wire is three times or more the thickness.

The magnetic core 11 provided with the

coil winding bodies

13a and 13b is supported by the resin base portion 14. The base portion 14 is insulated from the four

sides

15a, 15b, 15c, 15d on which the magnetic core 11 around which the first coil winding body 13a and the second coil winding body 13b are wound is placed, and the central portion. It is a resin frame made of a separator 16. The first and second

coil winding bodies

13a and 13b are arranged in the left and

right openings

17a and 17b of the base portion 14.

A first connection terminal 18, a second connection terminal 19, a third connection terminal 20, and a fourth connection terminal 21 are provided at each corner of the base portion 14 by press fitting or the like. These connection terminals 18 to 21 are formed by molding a metal such as copper, and a portion protruding from the upper surface of the base portion 14 is a portion to which the terminal lead portion of the electric wire is connected. The portion protruding from the lower surface is the portion connected to the substrate. The winding end ends 22a and 22b of the

coil winding bodies

13a and 13b are bent at substantially right angles to the end faces, respectively.

5, 6 and 7 show a modified example of one embodiment of the present technology. 5 is an external perspective view of a modified example, FIG. 6 is an exploded perspective view, and FIG. 7 is a perspective view showing a state in which the magnetic core 11 is wrapped by the upper case 31a and the lower case 31b. The two perspective views of FIG. 5 are perspective views viewed from different directions. The magnetic core 11 has no insulating coating. The upper cover 31a and the lower cover 31b have a structure in which the required creepage distance is secured and the upper cover 31a and the lower cover 31b are fitted to each other. The difference from the configurations shown in FIGS. 3 and 4 described above is whether an insulating coating or a resin cover is used to insulate the closed magnetic circuit magnetic core 11, which is the requirement of various safety standards in each country and the quality of the customer. It can be selected based on the request.

The manufacturing process of the coil device will be described by taking as an example the one using the resin cover described with reference to FIGS. 5, 6 and 7. With the magnetic core 11 incorporated in the upper cover 31a and the lower cover 31b (see FIG. 7), as shown in FIG. 8, a winding facility is used to push the flat wire in the direction of the arrow to bend the flat wire. It passes through the tool (not shown), draws a spiral along the peripheral surface of the resin cover composed of the upper cover 31a and the lower cover 31b, and winds the edgewise coil. As the winding equipment, for example, those described in JP-A-2017-130506 can be used.

The electric wire of the coil winding body 13a is wound from the winding start end (starting end) 23a toward the winding end end (end) 22a, and the electric wire of the coil winding body 13b is wound from the winding start end (starting end) 23b. It is wound from the winding end toward the end (end) 22b. When winding the electric wires to the left and right, it is possible to wind the electric wires one side at a time, but in general, two electric wires are wound at the same time in consideration of productivity. In this case, since the space at the time of winding is not so wide, it is assumed that the winding start ends 23a and 23b do not protrude outside the outer circumference of the

coil winding bodies

13a and 13b, or the amount of protrusion is small.

After the winding of the electric wire is completed, next, in order to join with the circuit board, both ends of the electric wire are further processed to provide a substrate bonding (lead) portion that can be directly bonded to the circuit board, or copper is used as the main material. A method is adopted in which soldering is performed via a connection terminal that has been surface-treated (plated, etc.). Connection terminals are often used to ensure stable quality. The present technology can be applied to any case.

As shown in FIG. 9,

connection terminals

18, 19, 20 and 21 are press-fitted into the four corners of the resin base portion 14. The parts provided with the

coil winding bodies

13a and 13b are vertically moved and incorporated along the insulating separator 16 provided at the center of the base portion 14. At this time, guide grooves are provided in the inner portions of the upper cover 31a and the lower cover 31b so that stable assembly is performed, and the side surface portions of the insulating separator 16 slide along the guide grooves and are incorporated. After assembly, work is performed to electrically connect the terminal lead portion of the coil winding body and various connection terminals. In this way, the coil device according to the present technology as shown in FIG. 10 is completed. FIG. 10 is a perspective view of the coil device viewed from different directions. Further, FIG. 11 is a view taken along the line CC of FIG.

The connection terminals 18 to 20 will be described. The

connection terminals

18 and 20 to which the winding start ends 23a and 23b are connected have the same structure, and the

connection terminals

19 and 21 to which the winding end ends 22a and 22b are connected have the same structure. FIG. 12 shows an enlarged portion A (connection terminal 20) in FIG. 10, and FIG. 13 shows an enlarged portion B (connection terminal 19) in FIG.

The connection terminal 20 is bent so as to have two surfaces (plate-shaped electrodes) having a surface substantially parallel to the surface of the electric wire (flat wire) of the winding start end 23b of the coil winding body 13b. The tip of the winding start end 23b is inserted and arranged in the facing gap (groove) of the surface of the winding. The connection terminal 19 is bent in a U shape so as to be substantially parallel to the surface of the winding end end 22a of the bent coil winding body 13a and to have two opposing surfaces (plate-shaped electrodes). .. The winding end end 22a is inserted so that the winding end end 22a of the coil winding body 13a abuts on the inner side surface on the back side of the two plate-shaped electrodes. After that, by bending one of the two plate-shaped electrodes, the winding end end 22a is sandwiched by the connection terminal 19.

In this way, the winding start ends 23a and 23b of the

coil winding bodies

13a and 13b are fitted in the grooves of the

connection terminals

18 and 20, and the substrate is not bent again in the edgewise direction. A joint (lead) portion can be formed, and the winding end ends 22a and 22b are made to abut on the inner side surface on the back side of the terminal bent in a U shape of the

connection terminals

19 and 21. As a result, the positions of the winding end ends 22a and 22b are arranged so as to be horizontal to the connection fixing surface of the

connection terminals

19 and 21. That is, the positions of the winding end ends 22a and 22b are regulated so as to be perpendicular to the base portion 14. By doing so, the winding end ends 22a and 22b can be easily bent, and flatwise bending that can be easily connected to the connection terminal can be performed.

After that, as shown in FIG. 13, the rotational motion of the coil winding body 13a is fixed by sandwiching the winding end end portion 22a between the upper surface portions of the connection terminals 19, and in that state, the connection terminal portions are soldered or the like. It is electrically joined. When performing solder bonding, by providing through holes on the upper surface of the connection terminal, the solder bonding area between the winding start end and winding end end and the connection terminal is expanded, and the mechanical bonding strength is improved. It is possible to improve the solder joining workability. In addition, instead of solder bonding, bonding using spot welding or the like may be performed. In this case, it is preferable to emboss a cylinder or an arc so that the welding current is concentrated and flows at the welding point instead of the terminal through hole. It is desirable that this series of work is automatically performed by equipment or the like.

14, 15, and 16 show a modified example of the connection terminal in one embodiment of the present technology. In the configuration of FIGS. 14 and 15,

connection terminals

19a and 21a in which the shape of the terminal lead portion sandwiching portion on the upper surface of the terminal of the

connection terminals

19 and 21 in the above-described embodiment is displaced by 90 ° are provided on the base portion 14. It is a thing. With such a configuration, the flatwise bending workability of the winding end ends 22a and 22b can be improved, so that automation by equipment or the like can be further facilitated.

Also, in the above explanation, the shape with the winding start end as the reference position has been explained, but on the contrary, the same productivity can be realized even if the winding end end is used as the reference position. However, when the winding end end is set as the reference fixed position, as shown in FIG. 16, the connection terminal 20 (18) and the connection terminal 20a whose bending direction is reversed are used. As a result, the degree of freedom in the fixed position of the winding start end is increased, and the bending position accuracy of the winding end end can be relaxed.

Further, FIGS. 17A and 17B are perspective views showing connection terminals of other embodiments of the present technology. In another embodiment, when the production quantity is small, even manual (manual) work can minimize the burden on the operator. Since the process up to the edgewise winding by the automatic winding machine is the same as that of the first embodiment, the description thereof will be omitted. In another embodiment, as shown in FIG. 17A,

connection terminals

31, 32, 33 and 34 are provided at each corner of the base portion 14. In the configuration shown in FIG. 17B,

connection terminals

31a, 32a, 33a and 34a in which the shape of the terminal lead portion sandwiching portion of these connection terminals is displaced by 90 ° are provided on the base portion 14.

After edgewise winding, the

coil winding bodies

13a and 13b are bent at approximately right angles (flatwise bending) so that they can be joined to the connection terminals. Each end portion bent at a substantially right angle to the end faces of the

coil winding bodies

13a and 13b is sandwiched by the sandwiching portions of the connection terminals 31 to 34 (or 31a to 34a). Then, as in the above-described embodiment, it is electrically joined by solder joining or the like.

It is very important to perform flatwise bending with the smallest load on the rectangular wires wound in the annular shape of the

coil winding bodies

13a and 13b. FIG. 18 shows a side view of a flat wire wound in an annular shape, and when the bending position of the winding start end is changed from A (winding center position) to bending position B and bending position C, bending is performed. It can be seen that the length of the long side of the cross section becomes longer. This means that when the conductor thickness is unchanged, the area of the bent cross section increases as the length of the long side of the bent cross section increases, and the load required for bending also increases. Bending is performed at the center position where the length of the long side of the bent cross section is minimized.

On the other hand, since a straight part remains at the end of winding, in this case, the required bending load does not change regardless of the position where flatwise bending is performed, but bending is performed at an annular position beyond the straight part. If this is done, the result will be the same as the winding start end described above. As a matter of course, if the bending load is small even in the bending process by the automatic equipment, the equipment cost can be reduced because the equipment can be small.

The coil device according to the present technology described above has the following effects.
It is possible to realize an inexpensive high power common mode winding.
Longer life by reducing damage to the insulating film layer It is possible to reduce component costs by reducing the number of workers by automating the work process.
The number of workers can be significantly reduced.
The price of production equipment can be reduced.

Although one embodiment of the present technology has been specifically described above, the present technology is not limited to the above-mentioned one embodiment, and various modifications based on the technical idea of the present technology are possible. .. Further, the configurations, methods, processes, shapes, materials, numerical values, etc. mentioned in the above-described embodiments are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, etc. may be used as necessary. May be good.

The present technology can also have the following configurations.
(1)
Magnetic core and
A plurality of coil winding bodies wound around the magnetic core so that the surfaces forming the long sides of the cross section of the flat wire are laminated.
A base portion that supports the magnetic core having the coil winding body and
A connection terminal provided on the base portion and connected to the end portion of the coil winding body is provided.
A coil device in which the connection terminal has a plate-shaped electrode that sandwiches the surface of the end portion derived from the coil winding body.
(2)
The coil device according to (1), wherein the magnetic core and the plurality of coil winding bodies are insulated from each other.
(3)
The coil device according to (1) or (2), wherein the conductor thickness of the flat wire is 0.4 mm or more, and the width of the flat wire is three times or more the thickness.
(4)
The coil device according to any one of (1) to (3), wherein the magnetic core is an integral shape.
(5)
The magnetic core is a frame type composed of four sides, and first and second coil winding bodies are provided on the left and right sides, respectively, and the first and second coil windings are provided in the vicinity of the upper and lower sides. The coil device according to (4), wherein the end portion of the body is led out.
(6)
The base portion is a frame type composed of four sides on which the magnetic core having the first and second coil winding bodies is placed and an insulating separator in the central portion, and is inside the left and right openings of the base portion. The first and second coil winding bodies are arranged in the base portion, and the first connection terminal, the second connection terminal, the third connection terminal, and the fourth connection terminal are respectively arranged at each corner of the base portion. The coil device according to any one of (1) to (5) provided.
(7)
The two opposing surfaces of the first and second connection terminals provided on the base portion are made substantially parallel to the surfaces of the coil winding body, and the first surface is in the facing gap between the two surfaces. The coil device according to (6), wherein the winding start ends of the first and second coil winding bodies are arranged.
(8)
The ends of the first and second coil winding bodies on the winding end side are bent at substantially right angles so that the surfaces are substantially horizontal, and the two opposing pieces of the third and fourth connection terminals are opposed to each other. The coil device according to (6), wherein the surface of the coil device is substantially parallel to the surface of the bent end portion, and the bent end portion is arranged in an opposing gap between the surfaces.
(9)
The winding start side and winding end side ends of the first and second coil winding bodies are bent at substantially right angles so that the surfaces are substantially horizontal, and the first to fourth connection terminals of the first to fourth connection terminals are bent. The coil device according to (6), wherein the two opposing surfaces are substantially parallel to the surface of the bent end portion, and the bent end portion is arranged in the facing gap of the plate-shaped electrode.
(10)
The coil device according to (9), wherein the bending position of the winding start end of the first and second coil winding bodies is near a position where the width of the first and second coil winding bodies is minimized. ..

11 ... Magnetic core, 13a, 13b ... Coil winding body, 14 ... Base part,
16 ... Insulation separator, 18, 19, 20, 21 ... Connection terminal,
22a, 22b ... winding end end, 23a, 23b ... winding start end,
31a ... top cover, 31b ... bottom cover

Claims

Magnetic core and
A plurality of coil winding bodies wound around the magnetic core so that the surfaces forming the long sides of the cross section of the flat wire are laminated.
A base portion that supports the magnetic core having the coil winding body and
A connection terminal provided on the base portion and connected to the end portion of the coil winding body is provided.
A coil device in which the connection terminal has a plate-shaped electrode that sandwiches the surface of the end portion derived from the coil winding body.
The coil device according to claim 1, wherein the magnetic core and the plurality of coil winding bodies are insulated from each other.
The coil device according to claim 1, wherein the conductor thickness of the flat wire is 0.4 mm or more, and the width of the flat wire is three times or more the thickness.
The coil device according to claim 1, wherein the magnetic core is an integral shape.
The magnetic core is a frame type composed of four sides, and first and second coil winding bodies are provided on the left and right sides, respectively, and the first and second coil windings are provided in the vicinity of the upper and lower sides. The coil device according to claim 4, wherein the end portion of the body is derived.
The base portion is a frame type composed of four sides on which the magnetic core having the first and second coil winding bodies is placed and an insulating separator in the central portion, and is inside the left and right openings of the base portion. The first and second coil winding bodies are arranged in the base portion, and the first connection terminal, the second connection terminal, the third connection terminal, and the fourth connection terminal are respectively arranged at each corner of the base portion. The coil device according to claim 1.
The two opposing surfaces of the first and second connection terminals provided on the base portion are made substantially parallel to the surfaces of the coil winding body, and the first surface is in the facing gap between the two surfaces. The coil device according to claim 6, wherein the winding start ends of the first and second coil winding bodies are arranged.
The ends of the first and second coil winding bodies on the winding end side are bent at substantially right angles so that the surfaces are substantially horizontal, and the two opposing pieces of the third and fourth connection terminals are opposed to each other. The coil device according to claim 6, wherein the surface of the coil device is substantially parallel to the surface of the bent end portion, and the bent end portion is arranged in an opposing gap between the surfaces.
The winding start side and winding end side ends of the first and second coil winding bodies are bent at substantially right angles so that the surfaces are substantially horizontal, and the first to fourth connection terminals of the first to fourth connection terminals are bent. The coil device according to claim 6, wherein the two opposing surfaces are substantially parallel to the surface of the bent end portion, and the bent end portion is arranged in the facing gap of the plate-shaped electrode.
The coil device according to claim 9, wherein the bending position of the winding start end of the first and second coil winding bodies is near a position where the width of the first and second coil winding bodies is minimized. ..