JP2003077730A - Common mode choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a common mode choke coil where normal mode impedance has been reduced. SOLUTION: The common mode choke coil 20 comprises a magnetic core 5 having square collars 2, 2 at both ends of a winding core 1, two directly mounted electrodes 8, 8 that are side by side on at least one peripheral surface 6 of each collar 2 in the magnetic core 5, and two insulating film conductors 4, 4 that are wound around the winding core 1 in the magnetic core 5, while both the terminals 4a and 4c, and 4b and 4d are led to the directly mounted electrode 8 in each collar 2 for conductive junction by a conduction junction section S by thermocompression bonding or the like. Especially, the two insulating film conductors 4, 4 are subjected to bifiler winding around the winding core 1 of the magnetic core 4. At the same time, the conductive junction section S by both the terminals 4a and 4c, and 4b and 4d of each insulating film conductor and the directly mounted electrodes 8, 8 is arranged closely each other to the center line in parallel with the winding shaft of the peripheral surface 6. Deriving sections 4f of the terminals 4c and 4d of the pair of insulating film conductors 4, 4 are close each other, the degree of combination is higher than before, and normal impedance is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire wound common mode choke coil used in various electronic devices.

[0002]

2. Description of the Related Art A common mode choke coil is a coil component used for filtering radiation noise of various electronic devices represented by personal computers.
It is one of coil components that cancels and removes common mode (in-phase component) noise of each line current flowing through a plurality of highly coupled coils (2 to 4).

In the conventional structure of the common mode choke coil described above, both ends of two to four insulation-coated conductive wires wound around the core of the coil bobbin are respectively led to terminal electrodes planted on the bottom surface or the side surface of the coil bobbin. It is generally of a structure in which it is braided and soldered. Further, for example, both of a drum type magnetic core as shown in (a) perspective view, (b) front view, and (c) side view of FIG. 10 disclosed in Japanese Unexamined Patent Publication (Kokai) No. 8-186028. A chip-type common mode choke coil 10 in which a flange 2 is provided with a direct-mounting electrode 3, a pair of insulating coating conductive wires 4 and 4 are wound around a winding core 1, and the ends of which are conductively joined to the direct-mounting electrode 3 ( 2 line type).

In the common mode choke coil 10 described above, as is apparent from the side view of FIG. 10 (c), the direct mounting electrodes 3 are provided on both sides of the flange 2 on the peripheral surface on the bottom side. And the conductive joint S between the ends of the two insulating coated conductors 4 and 4 and the direct-attached electrodes 3 and 3 of the collar 2 is located on the far end side of the direct-attached electrodes 3 and 3 that are farthest from each other. .

[0005]

From the viewpoint of improving the characteristics,
It is desirable to reduce the normal impedance of the common mode choke coil, and in order to do so, the insulation-coated conductors to be wound should be bifilar wound to increase the coupling between the insulation-coated conductors as much as possible. Is more important than other coil components.

In this regard, the applicant of the present invention has made a detailed examination of the characteristics of the common mode choke coil 10 having the conventional direct-attached electrode 3 and the state of drawing out the insulating coating conductor 4 to the direct-attached electrode 3. In order to reduce the impedance, a plurality of insulating coated wires 4 and 4 are attached to the winding core 1 of the magnetic core.
It was found that the degree of coupling between the lead-out portions of the bifilar winding and the lead-out portions that are pulled out from the winding core 1 and reach the directly-attached electrodes 3 provided on the collars 2 is a factor that cannot be ignored.

That is, as in the above-described conventional common mode choke coil 10 shown in FIG. 10, a pair of insulation-coated conductive wires 4, 4 wound around the core 1 is directly pulled out from the core 1. If the lead-out portions reaching the attachment electrodes 3 and 3 are separated from the wound core 1 immediately, the degree of coupling at the lead-out portions is lowered and the normal impedance is increased. .

Further, in the conventional common mode choke coil, the length of the lead-out portion from the winding core of the insulation-coated conductor to the electrode is significantly uneven due to the positional relationship of the electrodes provided on the collar, but the normal impedance is reduced. For this reason, it is assumed that it is desirable to make the lengths of the lead-out portions leading to the electrodes of each insulating coated wire as equal as possible.

Further, a direct mounting electrode 3 provided on the peripheral surface of the collar 2 such as the common mode choke coil 10 of FIG.
Since the lead-out portion of the insulating coated conductive wire 4 up to is bent at a substantially right angle at the corner of the collar 2, there is a drawback that it is weak against stress during conductive bonding by thermocompression bonding or soldering.

The present invention has been made in order to improve a wire-wound type common mode choke coil having the above-mentioned directly attached electrode, and it is possible to obtain a normal impedance in a common mode choke coil having a magnetic core provided with the directly attached electrode. A common structure in which the arrangement structure of the lead-out portion leading to the directly-mounted electrode and the conductive joint portion provided on the flange of the plurality of (2-4) insulating-coated conductive wires wound around the winding core is reduced so as to be reduced as much as possible. A mode choke coil is provided.

[0011]

In order to solve the above problems, the present invention provides (1) a magnetic core having square flanges at both ends of a winding core, and at least one peripheral surface of each of the flanges of the magnetic core. Two to four directly attached electrodes juxtaposed on top of each other and two to four wound around the core of the magnetic core, and both ends of which are led out onto the directly attached electrodes of each of the collars and conductively joined. In a common mode choke coil including two insulation-coated conductors, the two to four insulation-coated conductors are bifilar-wound around the core of the magnetic core, and one end of each insulation-coated conductor and one of the collars. There is provided a common mode choke coil characterized in that a conductive joint portion with a direct-attached electrode on a peripheral surface is arranged close to each other near a center line parallel to the winding axis of the peripheral surface. (2) Further, in the common mode choke coil according to the above (1), 2 to 4 direct-mounting electrodes are arranged side by side on the peripheral surface of the flange of the magnetic core on the bottom surface side, and Provided is a common mode choke coil, wherein conductive joints with terminals are arranged close to each other near a center line parallel to the winding axis of the peripheral surface. (3) Further, in the common mode choke coil according to the above (1), a guide C for leading out the insulating coating conductor wire to a winding core side edge of a peripheral surface of each flange on which the direct-attached electrodes are arranged in parallel.
Provided is a common mode choke coil having a surface. (4) Further, in the common mode choke coil according to the above (1), two to four insulating coated conductor wires are provided on a part of the winding core side edge of the peripheral surface of each flange on which the direct-attached electrodes are arranged in parallel. A common mode choke characterized in that one common guide C surface to be led out is provided, and the terminals of each insulation-coated conductive wire branch off from each other on the common guide C surface and are conductively connected to the direct-attached electrodes. Provide the coil. (5) Further, in the common mode choke coil according to the above (1), the insulating coated conductive wire is provided at a position near a center line parallel to a winding axis of a peripheral surface of each flange on which the directly-attached electrodes are arranged in parallel. A common mode choke coil characterized in that a conductive joint groove leading to a direct-mounting electrode is arranged, and a conductive joint portion between the direct-mounting electrode and an end of the insulating coated conductor is formed in the conductive joint groove. I will provide a. (6) Further, in the common mode choke coil according to (1), further including three bifilar wound insulating coated wires, a central electrode and both sides sandwiching the central electrode are provided on a peripheral surface on a bottom surface side of each flange of the magnetic core. Provided is a common mode choke coil in which three directly attached electrodes are arranged in parallel, and the area of the central electrode is smaller than that of both side electrodes.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of a common mode choke coil according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of the common mode choke coil of the first embodiment.

FIG. 2 is a perspective view of the common mode choke coil of the second embodiment.

FIG. 3 is a perspective view of the common mode choke coil of the third embodiment.

FIG. 4 is a perspective view of the common mode choke coil of the fourth embodiment.

FIG. 5 is a partial sectional view for explaining the formation of the conductive joint portion in the conductive joint groove according to the fourth embodiment.

FIG. 6 is a perspective view of the common mode choke coil of the fifth embodiment.

FIG. 7 is a perspective view of a common mode choke coil according to the sixth embodiment.

FIGS. 8A and 8B are examples of the patterns of the direct-attached electrodes of the common mode choke coil of the 3-line type.

FIG. 9 is a perspective view of a two-line type common mode choke coil using a rectangular wire according to the seventh embodiment.

The common mode choke coil 20 of the first embodiment shown in FIG. 1 has a magnetic core 5 (a ferrite molding or a resin molding mixed with magnetic powder) having square flanges 2 and 2 at both ends of a winding core 1. Body or a ceramic molded body such as alumina mixed with magnetic powder), two direct-attached electrodes 8 arranged in parallel on at least one peripheral surface 6 of each flange 2 of the magnetic core 5, and the magnetic material. While being wound around the core 1 of the core 5, both ends 4a and 4c, 4b and 4d are respectively led out onto the directly-attached electrodes 8 of the collars 2 and conductively joined at the conductive joint S by thermocompression bonding or the like. Two (a pair of) insulating coated conductors 4 and 4, and particularly, the two insulating coated conductors 4 and 4 are bifilar wound around the winding core 1 of the magnetic core 5 and each insulating coating is provided. Directly attached electrodes 8 on both ends 4a and 4c, 4b and 4d of the lead wire, Wherein the conductive bonding portion S of the peripheral surface 6
It is characterized in that they are arranged close to each other near the center line M parallel to the winding axis.

That is, the directly attached electrodes 8 arranged side by side on one peripheral surface 6 of each of the collars 2 have their edges 8e facing each other from the end of the peripheral surface 6 on the center line M of the peripheral surface 6. Since they are formed to be close to each other and the conductive joint portions S are arranged to be close to each other on the side of the edge 8e of the direct-attached electrode 8, the conductive joint portions S are arranged from the winding core 1 of the pair of insulating coated conductors 4 and 4 to the collar. The lead-out portions 4f of the corresponding terminals 4c and 4d that are drawn out to the two directly-attached electrodes 8 that are close to each other on the peripheral surface 6 of the two are arranged close to each other, and in the case of a pair line, the lead-out portions are as shown in FIG. Four
Since f is branched immediately before the direct-attached electrodes 8 and 8 and remains in a pair line for a long time, the degree of coupling can be made higher than that of the conventional one, and the normal impedance can be reduced. Of course, the conductive joint S formed on the side closer to the center of the peripheral surface 6 of the direct-attached electrode 8 spreads over the diameter of the insulating coated wire 4 on the electrode due to crushing due to a soldering fillet or thermocompression bonding, so that they do not short-circuit with each other. It is necessary to form them at a distance.

In the common mode choke coil 20 of FIG. 1, the direct mounting electrodes 8 are formed from one peripheral surface 6 of each flange 2 to the end surface and the opposite peripheral surface, and the peripheral surface 6 side is mounted at the time of mounting. The bottom surface may be solder-mounted on the substrate, or the opposite peripheral surface may be solder-mounted, and the vertical direction is arbitrary. However, from the viewpoint of reducing the normal impedance, it is preferable that the wiring other than the winding wound around the winding core 1 is short including the electrode portion. Therefore, the peripheral surface 6 having the upper conductive joint S in FIG. It can be said that it is preferable to mount it on the substrate by soldering it on the side. Assuming that the direct attachment electrodes 8 having the conductive joint S are mounted on the substrate with the bottom surface side as the bottom surface by giving the vertical directionality as the coil component in this manner, It is sufficient to form only on the 6 side (bottom side).

Next, the common mode choke coil 30 shown in FIG. 2 has a peripheral surface 6 on the bottom side of each flange 2 of the magnetic core 5.
Two direct-attached electrodes 8 are formed from approximately the edge to near the center line M parallel to the winding axis of the peripheral surface 6, and a conductive joint S with the end of each insulating coated conductor 4, 4 is formed. They are arranged close to each other near the center line M of the peripheral surface 6. In addition, the lead-out portions 4f of the insulating coated conductors 4, 4 leading to the direct-attached electrode 8 are led out to the edge of the peripheral surface 6 of the collar 2 on which the direct-attached electrodes 8, 8 are arranged in parallel. (Guide) Guide C surface 12
It is a structure in which (notches with slopes) are individually provided.

The guide C surface 12 is provided near the axis of the winding core 1 near the center line M parallel to the winding axis of the circumferential surface 6 and reaches the direct attachment electrode 8 of each insulating coated conductor wire 4, 4. Derivation part 4
The lead-out portion accompanying the conductive joining while ensuring the action of correctly guiding f to the conductive joint position near the center line M of the peripheral surface 6 of the direct attachment electrode 8 and the insulation between the adjacent lead-out portion 4f and the conductive joint S. It has the effect of softening the bend at the collar corner of 4f to prevent disconnection. Also in the above structure, since the conductive joint portions S are arranged close to each other, it is possible to keep the coupling between the lead-out portions 4f of the insulating coated conductors 4 and 4 high and reduce the normal impedance.

Next, the common mode choke coil 40 shown in FIG. 3 is provided on a part of the peripheral surface 6 of each collar 2 on which the directly attached electrodes 8 are arranged in the vicinity of the center of the edge on the winding core 1 side. One common guide C surface 14 through which the two insulation-coated conductors 4 and 4 are led out is provided, and each insulation-coated conductors 4 and 4 is provided.
The terminals are branched on the common guide C surface 14 or in the vicinity thereof, and are electrically connected to the directly attached electrodes 8 and 8 at positions near the center line M parallel to the winding axis of the peripheral surface 6. is there.

Therefore, the insulating coated conductors 4 and 4 (especially in the case of the paired wires) are almost the conductive joints S in the lead-out portions 4f.
A high coupling state is maintained until just before, the normal impedance is reduced, and the risk of disconnection at the flange portion of the lead-out portion 4f due to conductive bonding is avoided.

Next, the common mode choke coil 50 shown in FIG. 4 is located at a position near the center line M parallel to the winding axis of the peripheral surface 6 of each collar 2 on which the directly attached electrodes 8 are arranged in parallel. Conductive joint groove 1 for leading out the ends of the insulating coated conductors 4 and 4, respectively.
6 is arranged from the winding core 1 side of the collar 2 to the end face side, and the direct-attached electrodes 8 and 8 and the insulating coating conductive wire 4 are provided.
4 is a structure in which a conductive joint S with the end of No. 4 is formed in each conductive joint groove 16. Of course, the direct-attached electrode 8 is also formed on the inner surface of the conductive bonding groove 16.

The formation of the conductive joint S in the conductive joint groove 16 will be described in detail. As shown in FIG.
The electrodes 8 on the conductive bonding groove 16 on the bottom surface-side peripheral surface 6 are arranged close to each other with the central convex portion 17 of the peripheral surface 6 interposed therebetween. The conductive joint portion S is formed in the conductive joint groove 16 as shown in FIG. 5B without bulging to the outside of the conductive joint groove 16 although it is crushed by thermocompression bonding of H. That is, the conductive joint groove 16 is set to a depth that prevents the conductor of the insulation-coated conductor wire 4 from being excessively crushed while thermocompressing the conductor of the insulation-coated conductor wire 4 in a reliable and stable shape.
In addition, the volume is large enough to accommodate the conductive joint S. With the above configuration, since the peripheral surface 6 having the conductive joint S is substantially flat, it becomes stable even when mounted on the substrate as the bottom surface side. Further, since the lead-out portions 4f of the insulating coated conductor 4 are arranged close to each other until immediately before the conductive joint S, the normal impedance is reduced.

Next, the common mode choke coil 60 shown in FIG.
In addition to the above structure, the outer resin body 28 (2) that covers the outer circumference of the coil surface wound bifilarly on the peripheral surface 6 and the peripheral surface opposite to the peripheral surface 6 (2
An exterior groove 27 is provided to serve as an escape groove for the excess resin when the resin is molded to form a (dotted line) and to prevent the excess resin from entering the other area of the peripheral surface of the collar 2. Structure. The conductive bonding groove 16 is provided at the bottom of a wide outer package groove 27 formed on the peripheral surface 6, and the outer package groove 27 also serves as a guide for the heater chip H. The pattern of the direct-attached electrode 8 is shown in the same type as the common mode choke coil 20 described above, but of course the peripheral surface 6 on the substantially bottom side similar to the common mode choke coil 30.
Only patterns are acceptable.

Next, in the three-line type common mode choke coil 70 shown in FIG. 7, a central electrode 8b and both side electrodes 8a sandwiching the central electrode 8b are formed at the center of the peripheral surface 6 on the bottom side of each collar 2.
8c are arranged close to each other near the center line M parallel to the winding axis of the peripheral surface 6, and the lead-out portions 4f of the insulating coated conductors 4, 4, 4 are directly attached to the edge of the peripheral surface 6 on the winding core 1 side. Electrodes 8a, 8
This is a structure in which a guide C surface 22 (a notch having an inclined surface) leading (guided) to b and 8c is provided on all the edges. Then, the three insulating coated conductors 4, 4, 4 are bifilarly wound around the winding core 1 and led out along the guide C surface 22, and each end is conductively joined to the central electrode 8b and the side electrodes 8a, 8c. Structure. The action of the guide C surface 22 is similar to that of the partial guide C surface 12 described above.

In the three-line type common mode choke coil 70, the area of the central electrode 8b formed on the peripheral surface 6 of each collar 2 is smaller than that of the both side electrodes 8a and 8c, and the three conductive layers are provided. The joint portions S can be arranged close to each other near the center line M of the peripheral surface 6. Therefore, the three insulation-coated conductors 4, 4 and 4 have substantially the same length and maintain high coupling until just before the conductive joint S, thereby reducing the normal impedance.

It should be noted that each conductive joint S is formed near the center of the peripheral surface 6.
Although the difference in the length of the lead-out portion 4f can be suppressed by the close proximity to each other, it is desirable that the area of the central electrode 8b be as small as possible. For example, in FIG.
(b) is a configuration in which the shape of the central electrode 8b and both side electrodes 8a and 8c sandwiching the central electrode 8b is formed as an asymmetric pattern with a reduced depth dimension, and the length of the lead-out portion 4f of each insulating coated conductor 4 is shown in FIG. The difference is suppressed as much as possible.

The common mode choke coils 20, 30, 40, 50, 60, 70 described above are so-called round wires in which a plurality of insulating coated conductor wires 4 are covered with a resin such as polyurethane on the outer circumference of the conductor wire having a circular cross section. Although the present invention is used, the present invention may be applied to an insulating coated conductor other than a round single wire or a pair wire. For example, the common mode choke coil 80 shown in FIG. 9 has two so-called rectangular wires 24 (having a rectangular cross section). Since a pair wire or a single wire is used, it is possible to densely perform bifilar winding with a high current density without wasteful space, and since the coupling becomes high, it is suitable for reducing the normal impedance.

By the way, the common mode choke coil to which the present invention is applied includes a pair of insulating coated conductors 4 as described above.
Needless to say, the present invention is not limited to the two-line type in which the bifilar winding is performed, and the three-line type in which three to four insulating coated conductors as illustrated in FIG.

In addition, as a reminder, the common mode choke coil according to the present invention is a resin mold type in which the outer circumference of the coil is covered with a resin material or a common closed magnetic circuit structure in which a magnetic flat plate is added to the magnetic core 5. Of course, the mode choke coil is also within range.

[0038]

EFFECTS OF THE INVENTION The common mode choke coil according to the present invention has the above-described structure. (1) A plurality of directly attached electrodes formed on one peripheral surface of the collar are parallel to the winding axis of the peripheral surface. Close to the center line,
Bifilar-wound insulation coating Since each conductive joint between the conducting wire and the direct-attached electrode is entirely formed at a position near the center line parallel to the winding axis of the peripheral surface, each bifilar-wrapped insulation coating The lead-out portion of the conducting wire leading to the directly-attached electrode is also close to it, so that the coupling is maintained high and the normal impedance is reduced. (2) The strength of the lead-out portion of the insulating coated conductor is maintained by the partial or entire guide C surface provided on the peripheral edge of the peripheral surface to prevent disconnection, and the two insulating coated conductors are led out toward the center. It has the effect of guiding the parts and establishing the position of the conductive joints of each other. (3) The conductive joint groove formed on the peripheral surface of the collar at a position near the center line parallel to the winding axis serves as a guide to guide each end of the insulating coated conductor wire to form a groove at the conductive joint portion with the direct mounting electrode. Since it is formed in a reliable and stable shape inside, the bottom side is flat and the mounting stability is excellent, and there is no risk of short-circuiting even though the conductive joints are close, and the reliability is high.

[Brief description of drawings]

FIG. 1 is a perspective view of a common mode choke coil according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a common mode choke coil according to a second embodiment of the present invention.

FIG. 3 is a perspective view of a common mode choke coil according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a common mode choke coil according to a fourth embodiment of the present invention.

FIG. 5 is a partial cross-sectional view illustrating formation of a conductive joint portion in a conductive joint groove according to the fourth embodiment.

FIG. 6 is a perspective view of a common mode choke coil according to a fifth embodiment of the present invention.

FIG. 7 is a perspective view of a common mode choke coil according to a sixth embodiment of the present invention.

FIG. 8 is a pattern example of a direct-attached electrode of a 3-line type common mode choke coil and a form example of a lead-out portion of an insulating coated conductor.

FIG. 9 is a perspective view of a two-line type common mode choke coil using a rectangular wire according to a seventh embodiment.

FIG. 10 is (a) a perspective view, (b) a front view, and (c) a side view of a conventional common mode choke coil including a direct-attached electrode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Core 2 Collars 3, 8 Direct-attached electrodes 3a, 3c Both-sides electrodes 3b Central electrode 4 Insulation coating conductors 4a-4d Terminal 4f Lead-out part 5 Magnetic core 6 One peripheral surface (bottom side) 8 Direct-attached electrode 8b Central electrode 8a , 8c Both-sides electrodes 8e Edge of directly attached electrode 10 Common mode choke coil 12 having a conventional directly attached electrode 12 Guide C face 14 Common guide C face 16 Conductive joining groove 20, 30, 40, 50, 60, 70, 80 Common Mode choke coil 24 Flat wire M Center line S parallel to the winding axis of the peripheral surface S Conductive joint H Heater chip

Continued front page    (72) Inventor Kazuo Naganuma             6-16-20 Ueno, Taito-ku, Tokyo Sun invitation             Denden Co., Ltd. F-term (reference) 5E043 EB00                 5E070 AA01 CA04

Claims (6)

[Claims] 1. A magnetic core having square flanges at both ends of a winding core, 2 to 4 direct-attaching electrodes arranged in parallel on at least one peripheral surface of each flange of the magnetic core, and the magnetic core. Common-mode choke coil having two to four insulation-coated conductor wires wound around a winding core of the above and both ends of which are led out onto the directly-attached electrodes of each of the collars and conductively joined to each other. A plurality of insulation-coated conductive wires are bifilarly wound around the core of the magnetic core, and the conductive joints between both ends of each insulation-coated conductive wire and the directly-attached electrodes on one peripheral surface of each collar are winding shafts of the peripheral surface. A common mode choke coil characterized in that they are arranged close to each other near a center line parallel to. 2. The common mode choke coil according to claim 1, wherein 2 to 4 direct-mounting electrodes are arranged side by side on the peripheral surface of the flange of the magnetic core on the bottom surface side, and the terminals of each insulating coated conductor wire. A common mode choke coil, characterized in that the conductive joint portions thereof are arranged close to each other near the center line parallel to the winding axis of the peripheral surface. 3. The common mode choke coil according to claim 1, wherein a guide C is provided for leading out the insulating coated conductor wire to a winding core side edge of a peripheral surface of each of the collars on which the direct-attached electrodes are arranged in parallel.
A common mode choke coil having a surface. 4. The common mode choke coil according to claim 1, wherein 2 to 4 insulating coated lead wires are led out to a part of a winding core side edge of a peripheral surface of each of the flanges on which the direct-attached electrodes are arranged in parallel. The common mode choke coil is characterized in that one common guide C plane is provided and the terminals of each insulation-coated conductive wire branch off from each other on the common guide C plane and are conductively connected to the direct-attached electrodes. . 5. The common mode choke coil according to claim 1, wherein the insulating coated conductor is provided at a position near a center line parallel to a winding axis on a peripheral surface of each flange on which the directly-attached electrodes are arranged in parallel. A common mode choke coil, characterized in that a conductive joint groove leading to a mounting electrode is disposed and a conductive joint portion between the direct mounting electrode and an end of the insulating coated conductor is formed in the conductive joint groove. 6. The common mode choke coil according to claim 1, further comprising three bifilar wound insulating coated wires, wherein a central electrode and both side electrodes sandwiching the central electrode are provided on a peripheral surface of a bottom side of each flange of the magnetic core. In the common mode choke coil, the three directly attached electrodes are arranged side by side, and the area of the central electrode is smaller than that of both side electrodes.