JP2002134327A - Inductor component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductor component, which makes the fitting of a permanent magnet to the component easier and has a small size and a low height and for which a bias magnetic field can be set arbitrarily. SOLUTION: The inductor component is provided with at least a drum-type magnetic core 1, having upper and lower flanges 3 and 4 at both ends of its cylindrical section, boned permanent magnet 2 which impresses a bias magnetic field on the core 1, and on a coil wound around the core 1. The magnet 2 is wound around the upper flange 3 of the core 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smoothing choke coil used for an inverter and the like, and an inductor component used for a step-up and step-down choke coil for a DC-DC inverter.

[0002]

2. Description of the Related Art Heretofore, an inductor which applies a bias magnetic field to an inductor using a permanent magnet has been reported. An inductor to which a bias magnetic field is applied is characterized in that the magnetic saturation point can be increased with respect to voltage or current while maintaining the inductance if the number of windings is the same. As shown in FIG. 6, upper flanges 10 are provided at both ends of the cylindrical portion.
3. A coil is wound around a magnetic core 101 having a lower flange 104, and a permanent magnet 102 having a diameter substantially equal to the diameter of the flange is bonded to the upper surface of the upper flange 103 by bonding or the like. An inductor in which a bias magnetic field is applied to the magnetic core 101 has been reported.

An inductor having a permanent magnet for biasing on a magnetic core having flanges at both ends of a cylindrical portion is used mainly as a variable magnetic saturation inductor used for improving the horizontal linearity of a television. . For the magnetic core, Ni-Zn ferrite powder is used, and it is compacted by a press method and sintered. Alternatively, it is pressed into a columnar shape and sintered, and then a flange is formed by machining.

A permanent magnet for generating a bias magnetic field is manufactured by compacting powder such as Sr ferrite or Ba ferrite by a press method and sintering. As for mounting, they are integrated using an adhesive or the like. Set the polarity of the permanent magnet so that the magnetic flux created by the permanent magnet and the magnetic flux created by the coil are opposite to each other

[0005]

However, the above-mentioned conventional inductor component using a bias magnetic field has the following disadvantages. That is, in order to apply a large bias magnetic field to the magnetic core, the volume of the permanent magnet must be increased, and the outer shape cannot be increased, and the height of the inductor component increases. To increase the bias magnetic field by another method, there is a method of reducing the thickness of the flange of the magnetic core, but in manufacturing the magnetic core,
Very difficult and costly.

Further, in order to cope with the method without using a bias magnetic field, it is necessary to increase the size of the magnetic core itself, and it is not possible to cope with demands for miniaturization and reduction in height. The present invention
Utilizing a bias magnetic field with a conventional permanent magnet,
A low-profile inductor component can be applied, a large bias magnetic field can be applied, and a permanent magnet for generating the bias magnetic field can be fixed by a winding method that is easier to manufacture than conventional bonding. Provide inductor components.

[0007]

According to the present invention, a bonded magnet is used as a permanent magnet, and a magnetic core having flanges at both ends of a cylindrical portion or a magnetic core having flanges at both ends of a prismatic portion. If you want to adjust the strength of the bias magnetic field by setting the number of windings by mounting the permanent magnet for the bias magnetic field by winding it on the side instead of up and down, and if you want to apply more bias magnetic field, By covering the sleeve core, a required bias magnetic field can be applied, and a small, low-profile inductor component can be obtained.

That is, the present invention comprises at least a drum-shaped magnetic core having flanges at both ends of a cylindrical portion, a permanent magnet for applying a bias magnetic field to the magnetic core, and a coil wound around the magnetic core. In the inductor component, the permanent magnet is placed around a flange of the magnetic core by one.
It is to be wound around two places.

Further, according to the present invention, a rectangular drum-shaped magnetic core having rectangular flanges at both ends of a prismatic portion, a permanent magnet for applying a bias magnetic field to the magnetic core, and a magnetic core wound around the magnetic core. In an inductor component having at least a coil, one or two permanent magnets are wound around a flange of the magnetic core.

Further, the present invention uses the permanent magnet and winds it at one or two places around a flange of the magnetic core,
The arrangement is such that the bias magnetic flux generated by the permanent magnet and the magnetic flux generated by the coil face each other.

In the present invention, the permanent magnet uses a bonded magnet. Further, in the above-described inductor component, a magnetic material sleeve core that is in contact with the outside of the inductor component is provided.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

A drum-shaped magnetic core having flanges at both ends of a columnar portion is obtained by pressing a Ni-Zn ferrite powder into a columnar shape and then calcining. Thereafter, cutting is performed, and the main body is sintered and manufactured in a drum shape. It may be pressed into a columnar shape and sintered, and then cut, but the dimensional accuracy is high but the cost is high.

As a permanent magnet for applying a bias magnetic field, an Sm-Co system having a high Curie point is used for the hard magnetic powder. The reason is to use a material that is hardly demagnetized at high temperatures in consideration of reflow soldering to the inductor component. Next, the mixture is kneaded with a heat-resistant resin and mixed with Sm-C
Make a bonded magnet using o-based powder. Bond magnets
It is tape-shaped, and its end is wrapped around an adhesive tape on the back side and stopped.

FIG. 1 is a sectional view of a first embodiment of the present invention. The above-described tape-shaped bond magnet 2 is wound around a magnetic core 1 having flanges at both ends of the above-mentioned cylindrical portion. The bond magnet 2 is set so that the outer peripheral side of the upper flange 3 has N-polarity. The number of windings is determined by the value of the bias magnetic field.

FIG. 2 is a sectional view of a second embodiment of the present invention. In the inductor component of FIG. 1, when the bias magnetic field needs to be increased, a bond magnet is attached to the other lower flange 4. 12 is wound similarly. However, the polarities of the bond magnets 2 and 12 are such that the upper portion has the N-pole on the outer peripheral side of the upper flange 3 and the S-pole has the outer peripheral side of the lower flange 4 as described above.

FIG. 3 is a cross-sectional view of a third embodiment of the present invention, in which a bias magnetic field larger than the bias magnetic field in which the bond magnets 2 and 12 are wound around both the flanges 3 and 4 described in FIG. This is a structure used when voltage is applied. A sleeve core 25 made of a magnetic material is mounted on the outer periphery of the inductor component having the structure shown in FIG. The sleeve core 25 is made of a Ni-Zn ferrite material of the same material as the magnetic core 1 having the upper flange 3 and the lower flange 4 at both ends of the columnar portion.
The powder is pressed and sintered. An example of a method for fixing the sleeve core is an adhesive method.

FIG. 4 is a perspective view of a fourth embodiment of the present invention. A bond magnet 32 for applying a bias magnetic field to a magnetic core 31 having an upper flange 33 and a lower flange 34 at both ends of a prismatic portion, 42 is an inductor component wound with 42, and the polarity of the bond magnet for generating a bias magnetic field is the same as that of the third embodiment of the present invention. FIG. 5 shows a fifth embodiment of the present invention.
FIG. 5 is a perspective view of the embodiment, in which a square sleeve core 55 is mounted on the inductor component of FIG. 4. The polarity of the bond magnets 32 and 42 for generating the bias magnetic field is the same as in the third embodiment of the present invention.

A desired winding is applied to the core obtained in each of the above embodiments to obtain an inductor component.

The embodiments of the present invention have been described above. However, the method of fixing the bonded magnet and the method of fixing the sleeve core are merely examples of the method of implementation, and are not limited thereto.

[0021]

As described above, according to the present invention,
By using a drum-shaped magnetic core having flanges at both ends of a cylindrical portion or a prismatic portion, winding a bond magnet around the outer periphery of the flange, and setting the number of windings according to the strength of the bias magnetic field, A permanent magnet can be easily mounted, a bias magnetic field can be arbitrarily set, and a small and low-profile inductor component can be provided. In addition, when the bias magnetic field is applied in an increased manner, a method of winding the bond magnet on the lower flange in addition to the upper flange can be easily performed. An inductor component capable of increasing the bias magnetic field can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a second embodiment of the present invention.

FIG. 3 is a sectional view of a third embodiment of the present invention.

FIG. 4 is a perspective view of a fourth embodiment of the present invention.

FIG. 5 is a perspective view of a fifth embodiment of the present invention.

FIG. 6 is a sectional view of a conventional inductor component.

[Explanation of symbols]

 1 Magnetic core having flanges at both ends of cylindrical portion 2, 12 Bonded magnet 3 Upper flange 4 Lower flange 25 Sleeve core 31 Magnetic core having flanges at both ends of prismatic portion 32, 42 Bonded magnet 33 Upper flange 34 Lower flange 55 Square sleeve core 101 Magnetic core having flanges at both ends of columnar portion 102 Permanent magnet 103 Upper flange 104 Lower flange

Claims (5)

[Claims] An inductor component comprising at least a drum-shaped magnetic core having flanges at both ends of a cylindrical portion, a permanent magnet for applying a bias magnetic field to the magnetic core, and a coil wound on the magnetic core. An inductor component, wherein the permanent magnet is wound around one or two places around a flange of the magnetic core. 2. A semiconductor device comprising at least a rectangular drum-shaped magnetic core having square flanges at both ends of a prismatic portion, a permanent magnet for applying a bias magnetic field to the magnetic core, and a coil wound around the magnetic core. The inductor component according to claim 1, wherein the permanent magnet is wound at one or two locations around a flange of the magnetic core. 3. The inductor component according to claim 1, wherein the bias magnetic flux generated by the permanent magnet and the magnetic flux generated by the coil are arranged so as to face each other. 4. The inductor component according to claim 1, wherein the permanent magnet is a bonded magnet. 5. The inductor component according to claim 4, further comprising a magnetic sleeve core so as to be in contact with the outside.