JP2003109824A - Thin inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a conventional closed magnetic circuit type inductor using a drum-shaped core and a ring core has a structure mounting both the cores on an insulating base, and the whole height of the inductor can not be approximately 1 mm or thinner. SOLUTION: A thin inductor is provided with a drum core 10 having a small flange 12 and a large flange 13 on both the ends of a winding shaft part 11, a ring core 20 having a through hole 22 whose diameter is larger than the small flange 12 and smaller than the large flange 13, a plurality of electrodes 40 provided on the ring core 20, and a coil 30 wound around the winding shaft part of the drum core 10 and connecting a terminal to the electrodes 40. The small flange 12 is inserted in the through hole 22 to mutually fix the drum core 10 and the ring core 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin inductor used in various electric devices.

[0002]

2. Description of the Related Art A conventional closed magnetic circuit type inductor using a drum-shaped core and an annular core has a structure in which both cores are mounted on an insulating base.
It was not possible to reduce the height to a thickness of about m or less.
On the other hand, inductors using CI type cores and CC type cores are
Although it is a closed magnetic circuit structure and can be made relatively thin, there is a problem that the plane area becomes large and occupies a large mounting space.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thin inductor having a closed magnetic circuit structure, which is small in size, thin, and has less interference with peripheral circuits, which meets the high-density mounting requirement in a small device such as a mobile phone. .

[0004]

A thin inductor according to the present invention has a drum-shaped core having a small flange and a large flange at both ends of a winding shaft portion, and a through hole having a diameter larger than that of the small flange and smaller than that of the large flange. An annular core, a plurality of electrodes provided on the annular core, and a coil wound around a winding shaft portion of a drum-shaped core and having terminals connected to the electrodes, and a small flange is inserted into the through hole to form a drum shape. It is characterized in that the core and the annular core are fixed to each other. Further, the present invention, a drum-shaped core having a small collar and a large collar at both ends of the winding shaft portion, an annular core having a through hole having a diameter larger than the small collar and smaller than the large collar, and a base made of an insulating material, An electrode attached to this base and a coil wound around the winding shaft of the drum core and having terminals connected to the electrode are provided, and a small brim is inserted into the through hole to form the drum core, the annular core, and the base. It features an inductor fixed to each other.

[0005]

1 to 3 show an embodiment of an inductor according to the present invention. The drum-shaped core 10 made of a magnetic material has a cylindrical winding shaft portion 11, and two large and small flanges 12 and 13 are integrally formed at both ends of the winding shaft portion 11. Hereinafter, the collar 12 having a smaller diameter will be referred to as a small collar, and the collar 13 having a larger diameter will be referred to as a large collar. A coil 30 is wound around the winding shaft portion 11 of the drum-shaped core 10.

Numeral 20 is a rectangular magnetic flat plate with a small tsuba with a small diameter.
It is an annular core provided with a through hole 22 larger than 12 and smaller than the large flange 13. Electrodes 40 are attached to the side surfaces of both ends of the annular core 20, respectively. The electrode 40 is formed by bonding a bent metal plate, or by a known means such as printing or printing a conductor.

The small flange 12 of the drum-shaped core 10 is inserted into the through hole 22 of the annular core 20, and the annular core 20 is placed on the upper surface of the large flange 13. In this state, the annular core 20 and the drum core 10 are adhered and fixed to each other to form a closed magnetic circuit. As shown in FIG. 2, the terminals 31 and 32 of the coil 30 are drawn out to the electrodes 40 at both ends through the groove 25 provided in the wall surface of the through hole 22 of the annular core 20 and connected to the electrodes 40 by means of soldering or the like. is there. Instead of the groove 25, the ends 31 and 32 of the coil 30 are small flange 12 and annular core 20.
It may be pulled out through a gap between and.

4 to 6 show another embodiment of the present invention.
In addition to the drum-shaped core 10, the annular core 20 and the coil 30 described above, two bases 50 of the same shape made of an insulating material are used in this embodiment. The two bases 50 are drum-shaped cores 10.
At a position facing the side surface of the large collar 13 of the
It is glued and fixed to 13. The bases 50 are located symmetrically with respect to the large collar 13 and have a height dimension that does not project downward from the lower surface of the drum-shaped core 10. Gull wing type electrodes 40 are attached to the two bases 50, respectively. Although not shown, the end of the coil 30 is led out to the electrode 40 through a groove provided on the lower surface of the annular core 20,
It is wrapped around the electrode 40 and soldered.

Instead of two bases 50, FIGS.
A base 60 that integrates two bases 50 as shown in
May be used. The base 60 is a large flange of the drum-shaped core 10.
It has an annular shape with a hole 62 having a diameter larger than 13, and the large flange 13 of the drum core 10 is fitted into the hole 62. base
The 60 is also formed with a thickness that does not project downward from the lower surface of the drum core 10. Electrodes 40 of a type in close contact with the surface are attached to both ends of the base 60.

FIGS. 9 to 11 show another embodiment of the present invention, in which the base 60 is modified so that the protrusions are formed at both ends.
The base 70 integrally formed with 71 is used. As shown in FIG. 12, the base 70 made of an insulating material has a hole 72 having a diameter larger than that of the large flange 13 in the central portion, and has upwardly protruding portions 71 at both end portions. At both ends of the base 70, the protrusions 71
An electrode 40 extending to each is provided.

Then, the large flange 13 of the drum-shaped core 10 is fitted into the hole 72, and the octagonal annular core 20 placed on the large flange 13 is positioned between the two protruding portions 71 to form the drum. The shaped core 10, the annular core 20, and the base 70 are adhered to each other. The terminals 31, 32 of the coil 30 wound around the winding shaft portion 11 are the small collar 12 and the annular core 20.
It is led out to the outside through a gap between and and is soldered to the electrode 40. The height of the base 70 including the protruding portion 71 is set so as not to exceed the height of the drum-shaped core 10.

[0012]

According to the present invention, an extremely low-profile inductor having a closed magnetic circuit structure and a height of 1 mm or less can be realized. By using the flat plate-shaped annular core, the workability at the time of thinning is improved and the height can be easily reduced. The configuration shown in FIG. 1 has a feature that the height can be reduced with a small number of parts. In addition, the structures shown in FIGS. 7 and 9 are not only capable of reducing the height, but also have the effect that the thin annular core can be protected by the base and the degree of freedom in electrode formation is increased.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a first embodiment of an inductor of the present invention.

FIG. 2 is a plan view of the inductor.

FIG. 3 is a bottom view of the inductor.

FIG. 4 is a front sectional view showing a second embodiment of the inductor of the present invention.

FIG. 5 is a plan view of the inductor.

FIG. 6 is a bottom view of the inductor.

FIG. 7 is a front sectional view showing a third embodiment of the inductor of the present invention.

FIG. 8 is a bottom view of the inductor.

FIG. 9 is a front sectional view showing a fourth embodiment of the inductor of the present invention.

[Figure 10] Plan view of the inductor

[Fig. 11] Bottom view of the inductor

FIG. 12 is a perspective view of the base of the inductor.

[Explanation of symbols]

10 drum core 12 small tsuba 13 large tsuba 20 annular core 22 through hole

Claims (6)

[Claims] 1. A drum-shaped core having a small collar and a large collar at both ends of a winding shaft portion, an annular core having a through hole having a diameter larger than that of the small collar and smaller than that of the large collar, and provided on the annular core. A plurality of electrodes and a coil wound around the winding shaft of the drum core and having terminals connected to the electrodes, and a small brim is inserted into the through hole to fix the drum core and the annular core to each other. And thin inductor. 2. An electrode is attached to each side surface of both ends of an annular core formed by forming a through hole in a rectangular flat plate.
Thin inductor. 3. A drum-shaped core having a small collar and a large collar at both ends of a winding shaft portion, an annular core having a through hole having a diameter larger than the small collar and smaller than the large collar, and a base made of an insulating material. An electrode attached to the base, and a coil wound around the winding shaft of the drum core and having an end connected to the electrode, and a small brim is inserted into the through hole to form the drum core, the annular core, and the base. A thin inductor characterized by being fixed to each other. 4. The thin inductor according to claim 3, wherein the two bases are arranged so as to face the side surface of the large flange of the drum-shaped core and to be symmetrical with respect to the large flange. 5. The thin inductor according to claim 3, further comprising an annular base having a hole having a diameter larger than that of the large flange, and the large core of the drum-shaped core is fitted in the hole. 6. A base made of an insulating material having a hole having a diameter larger than that of the large tsuba in the center and provided with projecting portions at both ends, and the large tsuba of the drum-shaped core is fitted into the hole. 4. The thin inductor according to claim 3, wherein an annular core mounted on the large tsuba is arranged between the two protrusions.