JP7270122B2 - common mode choke coil - Google Patents

Description

TECHNICAL FIELD The present invention relates to a common mode choke coil having a core and wires, and more particularly to a common mode choke coil suitable for use in a common mode filter that removes noise.

In recent years, there has been a remarkable trend toward computerization in the automobile market, and the number of electric devices installed in each vehicle has been increasing more and more. An in-vehicle LAN is used for these communications, and in order to transmit a large amount of information, high speed and high reliability of communication quality are required. Therefore, countermeasures against unwanted radiation noise and common mode noise of high-frequency signals are required, and wire-wound common mode choke coils are often used.

Such conventional common mode choke coils consist of a ferrite magnetic core with flanges formed on both sides of the core, and a plurality of coils wound around the core of the magnetic core by bifilar winding or the like for several to several tens of turns. It is composed of a wire made of an insulated copper wire and a magnetic plate having substantially the same magnetic permeability as the magnetic core and having both flanges of the magnetic core bonded with an adhesive. A magnetic core and a magnetic plate are obtained by mixing a binder with ferrite powder, press-molding the mixture, and firing the mixture. Furthermore, a plurality of electrodes are formed on both collars or one of the collars, and the wire winding start end and winding end end are electrically connected to these electrodes by soldering, thermocompression bonding, or the like, respectively. It is In such a common mode choke coil, a desired impedance value is obtained by appropriately setting the number of turns of the wire wound around the winding core of the core.

Incidentally, Patent Document 1 and Patent Document 2 are known as examples of prior art document information related to the invention of this application.

Japanese Patent Application Laid-Open No. 2003-168611 JP 2014-75533 A

In CAN communication, which has been widely used in the past, there was no problem with a normal common mode choke coil. In general, as in Patent Document 1, a pair of windings are closely attached and wound around the winding core of the magnetic core so as to run in parallel. are electrically connected via Since the impedance of the stray capacitance component decreases as the frequency of the AC signal increases, a phenomenon occurs in which the AC signal leaks at each contact point of the two wires. In this AC signal, if the signal flowing from the first winding side to the second winding side and the signal flowing from the second winding side to the first winding side can be mutually canceled, good mode conversion characteristics can be obtained. Obtainable. In order to cancel the AC signal leaking through the film in the two wires, it is effective to balance the impedances at the contacts of the two wires. For example, if the two wires can be wound along the same trajectory over the entire area including the connecting wire portion, the impedance of the two wires can be considered to be in a substantially balanced state, and the mode conversion characteristics should be greatly reduced. However, since the connection positions of the two winding ends are physically separated, strictly speaking, the two wires do not draw exactly the same trajectory, which hinders the reduction of the mode conversion characteristics. As a product for Ethernet communication, for example, a method of dividing a winding region into a plurality of regions to control the stray capacitance of each line and reduce the mode conversion characteristic is used as in Patent Document 2. Since a space is required to separate the regions, it leads to degradation of inductance.

In order to solve this problem, the present invention provides a magnetic core comprising a core and first and second flanges provided at both ends of the core, and a first winding on the core. is wound directly, the second winding is wound mainly on the first winding, and the end of the first winding is connected to the first external electrode and the second collar provided on the first collar. A wire is connected to the provided second external electrode, and the terminal portion of the second winding is connected to the third external electrode provided on the first flange and the fourth external electrode provided on the second flange. A magnetic plate is adhered so as to straddle the first and second flanges, and the first and second windings are joined at the side portions through the winding lead-out portions. In the common mode choke coil, the cross section of the winding core is rectangular, and each point reaching the winding core from the winding lead-out portion of the first winding and the second winding is counted as one turn, Each time winding progresses along each surface of the winding core, the surface of the winding core corresponding to the first side of the first winding is designated as the first side, the second side, the third side, and the fourth side. The first surface, the surface of the winding core corresponding to the second side of the first winding is the second surface, the surface of the winding core corresponding to the third side of the first winding is the third surface, and the first winding When the surface of the core portion corresponding to the fourth side of is defined as the fourth surface, on the third surface n turns of the second winding and the n+1 turn third side of the second winding on the first surface, the n+1 turn third side of the second winding is the n+1 turn first side of the first winding and the n+1 turn third side It is arranged on the valley between one side, and the second winding is wound so as to cross the first winding on the second and fourth surfaces.

With the configuration as described above, even if the first winding and the second winding draw physically different trajectories, the impedances of the first winding and the second winding as a whole can be brought into a substantially balanced state. mode conversion can be suppressed, and a high inductance can be achieved because each turn does not require a space that degrades the inductance.

1 is an exploded perspective view of a common mode choke coil according to an embodiment of the present invention; FIG. 1 shows a first winding and a second winding wound in front of a winding core when viewing a magnetic core portion of a common mode choke coil in an embodiment of the present invention from a first direction; Pattern diagram 1 shows a first winding and a second winding wound in front of the winding core when viewing the magnetic core portion of the common mode choke coil in the embodiment of the present invention from the second direction. Pattern diagram 1 shows a first winding and a second winding wound in front of the winding core when viewing the magnetic core portion of the common mode choke coil in the embodiment of the present invention from the third direction. Pattern diagram 1 shows the first and second windings wound in front of the winding core when viewing the magnetic core portion of the common mode choke coil in the embodiment of the present invention from the fourth direction. Pattern diagram FIG. 3 is a schematic diagram showing part of the trajectory of the first winding wound around the winding core when the magnetic core portion of the common mode choke coil is viewed from the fifth direction in the embodiment of the present invention; FIG. 3 is a schematic diagram showing part of the trajectory of the second winding wound around the winding core when the magnetic core portion of the common mode choke coil is viewed from the fifth direction in the embodiment of the present invention;

A common mode choke coil according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of a common mode choke coil according to one embodiment of the present invention. The magnetic core 14 consists of a winding core portion 11 and a first flange portion 12 and a second flange portion 13 provided at both end portions of the winding core portion 11. A winding is formed by winding a conducting wire. The windings are composed of a first winding 15 and a second winding 16. The first winding 15 is wound directly around the winding core 11, and the second winding 16 is wound mainly on the first winding 15. It is A terminal portion of the first winding 15 is connected to a first external electrode 17 provided on the first flange portion 12 and a second external electrode 18 provided on the second flange portion 13 to form a second winding. A terminal portion of the wire 16 is connected to a third external electrode 19 provided on the first flange portion 12 and a fourth external electrode 20 provided on the second flange portion 13, and connected to the first flange portion 12. A magnetic plate 22 is adhered so as to straddle the second flange portion 13 and the second flange portion 13 . The first external electrode 17, the second external electrode 18, the third external electrode 19, and the fourth external electrode 20 are attached to the flange, and the end of the winding is the common mode choke coil. Connected on the side.

The size of this common mode choke coil is approximately 3.2 mm in length (in the winding core direction), approximately 2.5 mm in width, and approximately 2.2 mm in height. The thickness of the magnetic plate 22 is approximately 0.6 mm. Furthermore, the winding uses an insulated wire with a diameter of about 0.05 mm.

Each of the first flange portion 12 and the second flange portion 13 has a width of approximately 2.5 mm, a height of approximately 1.6 mm, and a thickness of approximately 0.7 mm.

The winding core 11 has a width of about 1.0 mm, a height of about 1.0 mm, and a length of about 1.6 mm.

FIG. 2 schematically shows a first winding 15 and a second winding 16 wound in front of the winding core 11 when the magnetic core 14 of this common mode choke coil is viewed from the first direction. is a diagram shown in FIG. A dashed line indicates the winding position of the first winding 15 and a solid line indicates the winding position of the second winding 16 .

Similarly, FIG. 3 shows a first winding 15 and a second winding 16 wound in front of the winding core 11 when viewing the magnetic core 14 of this common mode choke coil from the second direction. It is a figure shown typically.

FIG. 4 also shows a first winding 15 and a second winding 16 wound before the winding core 11 when the magnetic core 14 of this common mode choke coil is viewed from the third direction. It is a figure shown typically. 4 is upside down so that the winding position corresponds to that of FIGS. 2, 3 and 5. FIG. A dashed line indicates the winding position of the first winding, and a solid line indicates the winding position of the second winding.

Similarly, FIG. 5 shows a first winding 15 and a second winding 16 wound in front of the winding core 11 when the magnetic core 14 of this common mode choke coil is viewed from the fourth direction. It is a figure shown typically.

3 and 5, the dashed lines in FIGS. 3 and 5 simply show the core portions of the lead-out portions of the first winding 15 and the second winding 16 and the portions hidden by the first winding and the second winding. is.

The first winding 15 is connected to the first external electrode 17, wound around the winding core 11 from the winding lead-out portion 21a, and connected to the second external electrode 18 from the winding lead-out portion 21b. . Circled numbers shown in FIGS.

In FIG. 6, when the flange portion of the common mode choke coil is viewed from the fifth direction, the first winding 15 is drawn out from the first external electrode 17 to the winding core portion 11, forming a square winding core portion. 11 is a schematic diagram showing a trajectory wound on the wire 11. FIG. A dashed line in FIG. 6 indicates the trajectory of winding the first winding 15 . The first winding 15 is counted as one turn from the connection point between the winding lead-out portion 21a and the winding core portion 11, and each time the winding advances along each surface of the winding core portion 11, the first side and the second side are turned. A side, a third side, and a fourth side are counted as a second turn when the outer circumference of the winding core 11 is circumnavigated through the first side, the second side, the third side, and the fourth side. Thereafter, similarly, one turn is added each time the first side, the second side, the third side, and the fourth side are passed.

The second winding 16 is connected to the third external electrode 19, wound around the winding core 11 from the winding lead-out portion 21c, and connected to the fourth external electrode 20 from the winding lead-out portion 21d. . Strictly speaking, however, the second winding 16 is arranged on the already wound first winding 15, and the second winding 16 is placed on the valley where each turn of the first winding 15 contacts. will be placed.

Similarly, in FIG. 7, when the flange portion of the common mode choke coil is viewed from the fifth direction, the second winding 16 is drawn out from the third external electrode 19 to the winding core portion 11, forming a square winding. It is a schematic diagram which showed a part of locus|trajectory wound by the core part. As shown in FIGS. 6 and 7, the first winding 15 and the second winding 16 start winding from a position diagonal to the winding core 11 (position shifted by 1/2 turn). Become.

The surface of the winding core 11 corresponding to the first side of the first winding 15 is the first surface 23, the surface of the winding core 11 corresponding to the second side of the first winding 15 is the second surface 24, and the first When the surface of the core portion 11 corresponding to the third side of the winding 15 is defined as the third surface 25 and the surface of the core portion 11 corresponding to the fourth side of the first winding 15 is defined as the fourth surface 26, the On the third surface 25, the n-turn first side of the second winding 16 is arranged on the valley between the n-turn third side and the n+1-turn third side of the first winding 15 (see FIG. 3). On the surface 23, the n-turn third side of the second winding 16 is located on the valley between the n-turn first side and the n+1-turn first side of the first winding 15 (see FIG. 5).

On the second surface 24, the second side of n+1 turns of the first winding 15 and the fourth side of n turns of the second winding 16 cross each other (see FIG. 2). The fourth side of the turn and the second side of the n-turn of the second winding 16 cross each other (see FIG. 4).

With the above configuration, the difference in impedance for 1/2 turn between the first winding 15 and the second winding 16 becomes substantially zero during one turn, and The winding 15 and the second winding 16 are nearly balanced. This suppresses the mode conversion characteristics.

Although the cross section of the winding core is square in the above embodiment, it may be rectangular.

Further, if the arrangement of the first winding and the second winding is substantially the same, the winding direction of the first winding and the second winding may be reverse to that of the above embodiment. .

2, the final turn of the second winding 16 is wound directly around the winding core 11, but it is wound between the final turn of the first winding 15 and the second collar 13. Anything is fine. Alternatively, it may be wound between the second collar portion 13 and the winding one turn before the final turn of the second winding 16 . Thus, if the arrangement of the first winding 15 and the second winding 16 in the other turns being wound is substantially the same as the positions shown in FIGS. Since the balanced state of the impedances of 15 and the second winding 16 does not change so much as to affect the characteristics, only the last turn of the second winding 16 does not have to be the winding position described above.

INDUSTRIAL APPLICABILITY The common mode choke coil according to the present invention is industrially useful because it has excellent mode conversion characteristics and high inductance by bringing the impedance of the pair of windings close to an electrically balanced state. be.

11 winding core 12 first flange 13 second flange 14 magnetic core 15 first winding 16 second winding 17 first external electrode 18 second external electrode 19 third external electrode 20 fourth fourth external electrode 21a winding drawing portion 21b winding drawing portion 21c winding drawing portion 21d winding drawing portion 22 magnetic plate 23 first surface 24 second surface 25 third surface 26 fourth surface

Claims (2)

A magnetic core comprising a winding core and first and second flanges provided at both ends of the winding core, and a first winding directly wound on the winding core. A second winding is wound mainly on the first winding, and the end portion of the first winding is connected to the first external electrode provided on the first collar portion and the second collar portion. The terminal portion of the second winding is connected to the second external electrode provided on the first flange portion and the third external electrode provided on the first flange portion and the second electrode provided on the second flange portion. 4, is connected to the first winding and the second winding through the winding lead-out portion at the side portion, and is connected to the first collar portion and the second collar portion. A common mode choke coil having a magnetic plate adhered so as to straddle the core, wherein the cross section of the core is rectangular, and from the lead-out portions of the first winding and the second winding A turn is counted each time a turn is reached, and each time winding advances along each surface of the winding core, the first side, the second side, the third side, and the fourth side are counted. The surface of the winding core corresponding to the first side of the winding is referred to as the first surface, the surface of the winding core corresponding to the second side of the first winding is referred to as the second surface, and the surface of the winding core corresponding to the second side of the first winding is referred to as the second surface. When the surface of the winding core corresponding to three sides is the third surface, and the surface of the winding core corresponding to the fourth side of the first winding is the fourth surface, the third surface corresponds to the second surface. The n-turn first side of the winding is disposed on the valley between the n-turn third side of the first winding and the n+1-turn third side of the first winding, and the second side is located on the first surface. The n-turn third side of the winding is disposed on the valley between the n-turn first side of the first winding and the n+1-turn first side of the first winding, A common mode choke coil in which the second winding is wound so as to cross the first winding. On the second surface, the second side of n+1 turns of the first winding and the fourth side of n turns of the second winding cross, and on the fourth surface, the fourth side of n turns of the first winding and the fourth side of n turns of the first winding cross each other. 2. A common mode choke coil according to claim 1, wherein the n-turn second side of said second winding crosses.

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