JP2000106313A - Ferrite toroidal coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a ferrite toroidal coil which can be assembled easily, manufactured at low cost, and make the characteristics of a filter easily changeable or adjustable, without damaging a substrate. SOLUTION: A case 10, which has a cylindrical external shape and a doughnut-like internal cavity, can be divided into a case bottom plate 11 and a case cap 12 so that the whole internal cavity can be opened and made of an insulating material, is prepared. Terminals 20a and 20b are formed on the external surface of the case 10 and pattern wiring 30a and 30b both ends of which are respectively connected to the terminals 20a and 20b and which are spirally wound along the internal surface of the cavity, and the wirings 30a and 30b are connected to each other, when the case cap 12 is put on the case bottom plate 11. A doughnut-like ferrite core 40 is housed in the internal cavity of the case 10 for carrying the terminals 20a and 20b and the pattern wiring 30a and 30b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferrite toroidal coil, and more particularly, to a ferrite toroidal coil mounted on a substrate as a countermeasure against noise in a power supply circuit.

[0002]

2. Description of the Related Art A power supply circuit for supplying power to an electronic circuit is usually provided with a filter for reducing noise.
A ferrite toroidal coil is used as a main component of this filter. FIG. 4 shows a typical conventional example of such a ferrite toroidal coil.

[0003] The ferrite toroidal coil includes a donut-shaped ferrite core 40x having a predetermined magnetic permeability, and a coil winding 50 made of an insulated wire wound spirally around the ferrite core 40x. Then, both ends of the coil winding 50 are used by soldering to electrode wirings (pads or the like) on the substrate.

[0004] The coil winding 50 is made of a ferrite core 40x.
Helically wound, it is difficult to mechanize the wrapping work, and it is necessary to rely on manual work.

[0005]

The above-mentioned conventional ferrite toroidal coil has a structure in which the coil winding 50 is wound around the donut-shaped ferrite core 40x in a helical manner by hand, so that the manufacturing cost is reduced. There is a problem that it becomes high, and since the terminal of the coil winding 50 is used by being soldered to the substrate, when the filter characteristics need to be changed or adjusted, the soldering is removed and the magnetic permeability differs. The process of soldering another ferrite toroidal coil is repeated, and it takes a long time to obtain optimum filter characteristics, and the soldered portion of the board (electrode wiring such as pads) is damaged. There is a point.

SUMMARY OF THE INVENTION It is an object of the present invention to simplify the assembling work and reduce the manufacturing cost, and to easily change the filter characteristics without damaging the substrate when the filter characteristics need to be changed or adjusted. Another object of the present invention is to provide a ferrite toroidal coil which can be obtained in a short time.

[0007]

A ferrite toroidal coil according to the present invention has the following features in order to achieve the above object. (A) an insulating material having a predetermined shape and dimensions on the outside, a cavity cut into a donut inside, and a structure that can be divided and joined so that the entire cavity can be opened; (B) first and second terminals formed at predetermined portions on the outer surface of the case (c) one end is connected to the first terminal, and the other end is the second terminal
And is formed so as to be in close contact with the wall surface of the cavity of the case and to rotate along the wall surface in a spiral shape when the case is in a joined state, and to be connected to one coil winding. (D) The donut-shaped ferrite core housed in the cavity of the case where the first and second terminals and the pattern wiring are formed while maintaining insulation from the pattern wiring.

The case has a concave shape on one side and a convex shape on the other side at a portion corresponding to each of the pattern wiring forming portions on a divided joint surface for opening the entire cavity, and the case is in a joined state. In this case, the concave portion and the convex portion have a connecting portion that fits each other, and the pattern wiring extends to the connecting portion and covers the surfaces of the concave portion and the convex portion of the connecting portion. Is formed as
It has a structure having a conductor layer that is electrically connected to each other when the concave portion and the convex portion are fitted.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is such that the outside has a predetermined shape and size, the inside is provided with a hollow cut out like a donut, and the entire cavity can be opened. A case made of an insulating material formed into a structure that can be divided and joined, first and second terminals formed at predetermined portions on the outer surface of the case, and one end of the case is connected to the first terminal. Connected, the other end is connected to the second terminal, is in close contact with the wall surface of the cavity of the case, and is formed along this wall surface so as to spirally rotate when the case is in the joined state. A pattern wiring that is connected to one and forms a coil winding; and the first and second terminals, and are housed in a cavity of the case where the pattern wiring is formed while maintaining insulation from the pattern wiring. Donut-shaped ferrite core Configuration that has a structure.

With such a configuration and structure,
There is no need to wind the coil winding by hand, it can be easily formed by plating technology or printed wiring technology, and the assembly work only requires storing the ferrite core in the cavity of the case, so the manufacturing cost is reduced. In addition, when changing or adjusting the filter characteristics, it is only necessary to divide the case and replace it with a ferrite core with a different magnetic permeability while keeping it connected to the board, so that the optimum filter characteristics can be adjusted. Easily, without damaging the board,
And it can be obtained in a short time.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing one embodiment of the present invention,
FIG. 2 is a view showing the inside of a cavity when a case where terminals and pattern wiring are formed in this embodiment is divided, and FIG. 3 is a cross-sectional side view of the assembled state of this embodiment.

In this embodiment, a case bottom plate 11 and a case lid are provided so that the outside has a cylindrical shape having a predetermined dimension, and has a hollow cut into a donut inside, and the whole cavity can be opened. 12, a case 10 made of an insulating material formed in a structure that can be divided and joined, first and second terminals 20a, 20b formed on the side surface of the case bottom plate 11 on the outer surface of the case 10, and one end. Is terminal 20
a and the other end is connected to the terminal 20b.
The pattern wirings 30a, which are formed so as to be in close contact with the wall surface of the cavity of the cavity 0 and along the wall surface so as to rotate spirally when the case 10 is in the joined state, thereby forming a single coil winding. A donut shape having a predetermined magnetic permeability and housed in the cavity of the case 10 in which the terminals 30a, the terminals 20a, 20b, and the pattern wirings 30a, 30b are formed while maintaining insulation from the pattern wirings 30a, 30b. And a ferrite core 40.

The terminal 2 on the divided / joined surface of the case bottom plate 11 and the case lid 12 for opening the entire cavity of the case 10
The connection holes H (consisting of H11 to H19, H21 to H28) are formed on the case bottom plate 11 side at the portions corresponding to the formation portions of the wiring patterns 0a and 20b and the pattern wirings 30a and 30b. B (B11 to B1
9, B21 to B28) are formed, and on the surfaces of the connection holes H and the connection protrusions B, a conductor layer connected to the corresponding pattern wirings 30a and 30b and the terminals 20a and 20b is formed.

Then, the case bottom plate 11 and the case lid 12
When the connection holes H and the connection protrusions B are fitted together, the conductor layers on these surfaces are electrically connected to each other, the pattern wirings 30a and 30b are connected to one, and both ends are connected to the terminals 20a and 20a. It becomes a spiral coil winding connected to 20b.

The two-digit numbers following H and B in FIG. 2 indicate that the same numbers fit together. Also, the terminal 20
Although the distance between the connection holes H11 and H19 and the connection protrusions B11 and B19 corresponding to a and 20b is narrower than the distance between the connection holes and the connection protrusions of the other portions, the connection can be performed at only one place. A positioning key can be provided when these are arranged at equal intervals and can be joined at a plurality of locations, or in order to facilitate joining work.

With such a configuration and structure,
The coil winding can be easily formed by a plating technique or a printed wiring technique without relying on manual work, and the case 10 can also be assembled by using the case bottom plate 11 and the case lid 1.
Since the ferrite core 40 is divided into two parts, and the ferrite core 40 is housed in the cavity of the case 10 and the case bottom plate 11 and the case lid 12 are recombined with each other, a simple and short operation can be performed, so that the manufacturing cost can be reduced. Further, when changing or adjusting the filter characteristics, the case lid 12 is separated from the case bottom plate 11 with the case bottom plate 11 connected to the substrate (while still attached), so that the ferrite cores having different magnetic permeability can be formed. Since a simple operation of exchanging them and recombining them is sufficient, optimum filter characteristics can be obtained easily and in a short time without damaging the substrate.

In this embodiment, the case 10 is divided into asymmetrical portions of the case bottom plate 11 and the case lid 12, but may be divided into symmetrical portions. Although the external shape is cylindrical in this embodiment, the external shape can be a shape according to the conditions for attaching to a substrate or the like.

[0018]

As described above, according to the present invention, the outside has a predetermined shape and size, the inside is provided with a hollow cut out like a donut, and the inside is divided so that the whole cavity can be opened. First and second terminals are formed on a predetermined portion of the outer surface of the case having a possible structure, and both ends are connected to the first and second terminals on the wall surface of the cavity of the case. When the case is in a joined state, pattern wiring is formed so as to be in close contact with the wall surface and to rotate spirally along the wall surface, and is connected to one to form a coil winding. After being housed in the cavity, this case is re-assembled in a configuration and structure, so that the coil winding can be easily formed by plating and printing techniques without relying on manual work, and assembly work is also possible. Simple and short Since the work can be completed, the manufacturing cost can be reduced.In addition, when the filter characteristics need to be changed or adjusted, the magnetic permeability can be reduced while the one case of the divided structure is connected to the substrate or the like. Since different ferrite cores may be replaced, the effect is obtained that the optimum filter characteristics can be obtained easily and in a short time without damaging the substrate.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention.

FIG. 2 is a diagram showing the inside of a cavity at the time of division of a case in which terminals and pattern wiring are formed in the embodiment shown in FIG. 1;

FIG. 3 is a sectional side view showing an assembled state of the embodiment shown in FIG. 1;

FIG. 4 is a perspective view showing an example of a conventional ferrite toroidal coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Case 11 Case bottom plate 12 Case lid 20a, 20b Terminal 30a, 30b Pattern wiring 40, 40x Ferrite core 50 Coil winding B, B11-B19, B21-B28 Connection protrusion H, H11-H19, H21-H28 Connection hole

Claims (2)

[Claims] 1. A ferrite toroidal coil having the following components. (B) an insulating material having a predetermined shape and dimensions on the outside, a cavity cut into a donut inside, and a structure that can be divided and joined so that the entire cavity can be opened. (B) first and second terminals formed at predetermined portions on the outer surface of the case (c) one end is connected to the first terminal and the other end is the second terminal
Are formed so as to be in close contact with the wall surface of the cavity of the case, and to rotate along the wall surface in a helical manner when the case is in a joined state. (D) a donut-shaped ferrite core housed in the cavity of the case where the first and second terminals and the pattern wiring are formed while maintaining insulation from the pattern wiring. 2. The case has a concave shape on one side and a convex shape on the other side at a portion corresponding to each of the pattern wiring forming portions on a divided bonding surface that opens the entire cavity, and the case is in a bonded state. In this case, the concave portion and the convex portion have a connecting portion that fits each other, and the pattern wiring extends to the connecting portion and covers the surfaces of the concave portion and the convex portion of the connecting portion. The ferrite toroidal coil according to claim 1, wherein the ferrite toroidal coil has a structure formed as described above and having a conductor layer that is electrically connected to each other when the concave portion and the convex portion are fitted.