JPS62286211A - Chip coil - Google Patents

Abstract

PURPOSE:To prevent the lowering and the irregularity of inductance of the title chip coil by a method wherein a pair of external electrodes, connected to both ends of a wiring or spiral-shaped conductor, is annularly formed on both end parts of the side face of a ferrite core. CONSTITUTION:Annular external metal electrodes 5a and 5b are fitted to both end parts on the side face of a ferrite core 1 respectively. One end part of a covering-exforiated wiring 2 is electrically connected to the external electrode 5a, and the other end part of the covering-exforiated wiring 2 is electrically connected to the external electrode 5b. As a metal, namely, the external electrode, is not present on the end face of the ferrite core 1 where magnetic flux is concentrated, the lowering of the Q of a chip coil, the decrease in inductance, the irregularity in inductance and the like can be removed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of the Invention) The present invention relates to a chip coil in which a pair of annular external electrodes are formed on substantially both end portions of the side surfaces of a columnar ferrite core.

(Prior Art) Conventionally, there are chip coils shown in C% Figures 5 and 6.

The chip coil shown in FIG. 5 has a coated winding +1112 wound around the side surface of the cylindrical ferrite core shown in FIG. Electrical conductors 43a and 3b are fitted. One end of the winding 2 with the sheath removed is electrically connected to the C1 external electrode i3a, and one end of the winding 27 with the sheath stripped is electrically connected to the external electrode 3b.

On the other hand, in the chip coil shown in FIG. 6, a spiral conductor 4 is firmly attached to the side surface of a cylindrical ferrite core 1, and a cap-shaped external conductor 4' is attached to both ends of the ferrite core 1. and 5b are fitted. One end of the conductor 4 is electrically connected to the C1 external electrode 13a, and the other end of the conductor 4 is electrically connected to the external electrode 6b. An insulating paint may be further applied to the side surface of the ferrite core 1 to which the conductor 4 is fixed.

A spiral conductor 4 is fixed on the side of the ferrite core 1.
Method C is to form a groove on the side surface of the ferrite core 1 at the part where the conductor 4 is to be fixed, and then apply a conductive material such as copper to the entire side surface of the ferrite core 1 by plating, vapor deposition, paste baking, etc. C is fixed by the method, and the conductive material that is fixed to the part other than the groove is polished and C is peeled off.
The C conductor 4 can be formed by leaving only the conductor 4, or by fixing a conductive material such as copper on the entire side surface of the ferrite core 1 by plating, vapor deposition, paste baking, etc., and trimming the parts other than the conductor 4 with a laser. Many methods are being adopted, such as leaving only the remaining part.

(Problems to be Solved by the Invention) However, the conventional chip coil described above has the following problems. That is, the chip coils shown in FIGS. 5 and 6 both have a ferrite core 1.
The end face of the C ferrite core 1 is the part where the magnetic flux is most concentrated;
If 5a and 3b exist, there is a problem that when the magnetic flux changes, an eddy current is generated in the external \tM3a3b, the magnetic flux is blown out, and the Q of the C chip coil is lowered. In addition, magnetic flux is generated due to the eddy currents generated in the external layers i3a and 3b, and this magnetic flux acts to prevent changes in the magnetic flux inherent in the chip coil, causing the inductance of the chip coil to decrease and There was a problem that the inductance varied.

(Means for Solving the Problems) The present invention has been made in order to solve the problems of the conventional chip coils described above.

As a means for achieving this, the chip coil of the present invention has a pair of annular external 'N
The L pole was formed into a ring shape. In other words, the chip coil of the present invention eliminates the presence of metal, that is, an external component, right on the edge of the ferrite core where magnetic flux concentrates, thereby reducing the Q, inductance, and inductance variation of the C1 conventional chip coil. It is to solve the problem.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

The same parts as those explained in the section of the prior art are given the same numbers, and the explanation thereof will be omitted.

FIG. 1 shows an embodiment of the chip coil of the present invention.
There is. In this chip coil (x5a+5b are metal annular external electrodes, which are fitted to both ends of the side surface of the ferrite core 1, respectively).Then, C1 external electrode (i5
One end of the winding @2 from which the sheath has been stripped is electrically connected to LL, and the other end of the winding 2 from which the sheath has been stripped is electrically connected to the outer layer 15b.

FIG. 2 shows another embodiment of the chip coil of the present invention.
There is. In this chip coil, C,5IL.

5b is an annular external electrode made of wood, which is formed on both ends of the side surface of the ferrite core 1, respectively. SoshiC
One end of the spiral conductor 4 is electrically connected to the first external electrode 5, and the other end of the conductor 4 is electrically connected to the external layer 15b.

The side surface of the ferrite core 1 to which the conductor 4 is fixed may be further coated with a zero-R paint.

The above is only an example of the chip coil of the present invention, and it goes without saying that the design may be changed without departing from the spirit of the present invention. For example, in the above embodiment, the external '1ii
5a, 5b and C are circular, but they are external! The shape of the bowl can be arbitrarily selected depending on the shape of the ferrite core used. FIG.
This is a chip coil in which parts a and 15b are fitted.

Further, instead of using a metal-shaped product formed as an external one, it is also possible to form an external electrode by baking a conductive paste or the like.

Furthermore, the external electrode does not necessarily have to be a separate member;
Alternatively, the end of the winding wire wound around the ferrite core or the end of a fixed spiral conductor may be used as the external electrode. FIG. 4 shows the outer electrodes 25a and 2 after peeling off the covers 27 from both ends of the winding 2 wound around the ferrite core 1.
51) is the chip coil.

(Invention @4) As is clear from the above description, the chip coil of the present invention has a pair of annular external electrodes formed on substantially both end portions of the side surface of a columnar ferrite core. The chip coil of the present invention having such a configuration has no metal, ie, external electric current, on the end face of the ferrite core where the magnetic flux concentrates, so it has no reduction in Q and inductance, which conventional chip coils have. Problems such as reduction in inductance and variations in inductance have been solved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the first embodiment of the chip coil of the present invention, FIG. 2 is a perspective view showing the second embodiment, FIG. 6 is a perspective view showing the sixth embodiment, and FIG. This figure is a perspective view showing a fourth embodiment, FIGS. 5 and 6 are perspective views showing a conventional chip coil, and FIG. 7 is a perspective view showing a cylindrical ferrite core. 1.11 ... Ferrite core, 2 ... Winding wire, 4 ... Spiral conductor, 5a* 5b
, +5a, 15b25125b...external electric spoon.

Claims (1)

[Claims] In a chip coil in which a winding is wound around the side surface of a columnar ferrite core or a spiral conductor is fixed, a pair of external wires connected to both ends of the winding or the spiral conductor are provided. A chip coil characterized in that electrodes are formed annularly at substantially both ends of the side surface of a ferrite core.