JP2516849Y2 - Common mode choke coil - Google Patents

Description

[Detailed Description of Device] a. Purpose of the Invention [Industrial field of application] The present invention relates to a common mode choke coil used for suppressing electromagnetic noise in the MHz band of electronic devices.

[Prior Art] A conventional common mode choke coil has a terminal configuration as shown in FIGS. 3 and 4, in which a plurality of concentric coils 13, 14, 23, and 24 are provided at respective end portions of the coils. The lead wires at the start point and the end point were electrically and mechanically connected to the terminals 11, 12, 21, and 22 by a method such as entanglement, soldering, or welding.

In the configuration shown in FIG. 3, the rising portions 11c and 12c connecting between the coils 13 and 14 and the terminal external electrode portions 11b and 12b made of a metal good conductor are the magnetic fluxes generated by the coils 13 and 14 in the plane direction. Since it cuts off, an eddy current is generated in the rising part of the terminal, the inductance component for the signal in the in-phase direction deteriorates, noise absorption at high frequencies is reduced, and the soft magnetic material 15 is structurally integrated with the coil. However, there is a drawback that the coil rotates during the filling and molding, which causes variations in characteristics after molding. Further, in the connection between the coil end and the external electrode portion shown in FIG. 4, it is difficult to accurately position the coil, and further, when the soft magnetic material 25 is filled, the coils 23 and 24 and the terminals 21 and 22 are displaced from each other. However, there is a drawback that the characteristics of the molded product vary greatly.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned drawbacks and more firmly fixes each coil after integral filling molding of a soft magnetic material and a terminal, a part of which forms an external electrode portion, An object of the present invention is to provide a common mode choke coil that reduces eddy currents generated in the rising portion, enables noise absorption in a wider frequency band, and has no variation in characteristics.

B. Configuration of the Invention [Means for Solving the Problems] The present invention is directed to one end of a metal plate made of a good electrical conductor.
Each coil has a diameter that is almost the same as that of the coil, and a coil joint having a hole that is partially lacking and an electrode for mounting on a printed circuit board or the like are formed at the other end, and a rising portion that connects them is formed. The terminals that it has are mechanically and electrically surface-bonded to both ends of each coil by soldering and welding,
Further, the common mode choke coil is configured such that the magnetic flux generated by the magnetic field generated by the coil of the terminals is parallel to the plate surface of the rising portion.

That is, the present invention includes a plurality of coils wound in the same direction,
In a common mode choke coil in which terminals connected to both ends of each of the plurality of coils and inner and outer circumferences of the plurality of coils are filled and molded with a soft magnetic material containing resin,
The terminal is a plate-shaped metal conductor consisting of a coil joint portion, an external electrode portion, and a rising portion connecting them, and the coil joint portion is a plate shape with a hole having substantially the same shape as the cross section of the coil, In the common mode choke coil, the plate surface of the rising portion is arranged so as to be orthogonal to the direction of the induced voltage generated by the magnetic flux generated by the current flowing in each coil.

[Operation] The common mode choke coil according to the present invention is for suppressing common mode electromagnetic noise in the MHz band, but the coil is formed in order to prevent a reduction in the inductance component for signals in the in-phase direction even in the MHz band. By making the direction of the voltage induced by the magnetic flux perpendicular to the surface of the metal conductor that constitutes the rising portion, the eddy current generated in the rising portion is made extremely small, and the inductance component for signals in the same phase direction The frequency at which the noise starts decreasing is increased, and the common mode choke coil is effective for noise absorption in a wide frequency band.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a perspective view of a common mode choke coil according to the present invention, and FIG. 2 is an exploded front view thereof. The solid line indicates the coil 3, the coil 4 and the terminals 1 and 2 before being filled with the soft magnetic material 5 shown by the one-dot chain line. The common mode choke coil according to the present invention includes two coils 3 and 4 that are coaxially combined, terminals 1 and 2 that are connected to both ends of each coil 3 and 4, and two coils 3 and 4, and a resin. In addition, it is made of a soft magnetic material in which a ferrite having a high relative electric-insulation property such as Ni-Zn ferrite is incorporated. Terminals 1, 2
Is composed of external electrode portions 1b and 2b, coil joint portions 1a and 1b, and rising portions 1c and 2c. Both ends of the two coils 3 and 4 are processed so that they can be surface-bonded to the terminals 1 and 2.
Further, the terminals 1 and 2 have substantially the same shape as the cross section of the coil, and have holes partially cut off. Coils 3 and 4 are terminals 1 and 2.
Are welded and connected to the coil joint portions 1a and 2a. Further, the rising portions 1c and 2c of the terminals have a flat plate shape, and have a plane direction orthogonal to the plane of the electrodes, and are substantially the same as the magnetic flux direction generated in the soft magnetic body by the magnetic field generated by the coil. Therefore, the induced voltage generated in the rising portions 1c and 2c by the magnetic flux generated by the coil is arranged in the direction of the thickness of the conductor plate of the rising portions 1c and 2c. Therefore, the eddy current generated in the rising portions 1c and 2c is smaller than that of the conventional structure,
The reduction of the inductance component for signals in the in-phase direction in the MHz band was improved. The conductor plates of the rising portions 1c and 2c may be formed in a foil shape so as to be thin and integrally formed with a poor electrical conductor such as resin or ceramic.

Although each coil of the present embodiment uses a solenoid having a circular cross section, the present effect can be obtained without affecting any shape such as a square, a triangle or a circle.

C. Effect of the Invention [Effect of the Invention] According to the present invention, the magnetic flux generated by the current flowing in each coil does not cross the surface of the rising part of the terminal, and the eddy current generated in the rising part causes MHz. The reduction of the inductance component in the band is improved, it becomes a characteristic effective for noise absorption in a wide frequency band, moreover, the accurate positioning with each coil can be performed, and the connection of the coil and the terminal is the result of the surface joining, Since the connection strength of the terminals is also large, we were able to realize a highly reliable common mode choke coil with higher performance than before, with less variation.

[Brief description of drawings]

FIG. 1 is a perspective view of a common mode choke coil according to the present invention. FIG. 2 is an exploded front view of the common mode choke coil according to the present invention. FIG. 3 is a perspective view of a conventional common mode choke coil. FIG. 4 is a perspective view of another conventional common mode choke coil. 1,2,11,12,21,22 ... Terminals 1a, 2a, 11a, 12a ... Coil joints 1b, 2b, 11b, 12b ... External electrode portions 1c, 2c, 11c, 12c .. 3, 4, 13, 14, 23, 24 ... Coil 5, 12, 25 ... Soft magnetic material

Claims (1)

(57) [Scope of utility model registration request] 1. A common in which a plurality of coils wound in the same direction, terminals connected to both ends of each of the plurality of coils, and inside and outside of the plurality of coils are filled and molded with a soft magnetic material containing resin. In the mode choke coil, the terminal is a plate-shaped metal conductor including a coil joint portion, an external electrode portion, and a rising portion that connects them, and the coil joint portion has substantially the same shape as the cross section of the coil. A common mode choke coil having a plate shape with holes, wherein the plate surface of the rising portion is arranged so as to be orthogonal to the direction of the induced voltage generated by the magnetic flux generated by the current flowing through each coil.