JPH0555048A - Coil device - Google Patents

Abstract

PURPOSE:To obtain a coil device which can be attached to a circuit board simply and made thin by a method wherein a core which is composed of a plurality of core members combined so as to form a magnetic path through an opening part in the circuit board; a winding which has been formed between the circuit board and the core in a state that it has been wound on the core; and the like, are prouded. CONSTITUTION:The coil device is provided with a circuit board 10 provided with opening parts 10a, 10b; and a core 15 composed of a plurality of core members 15a, 15b combined so as to form a magnetic path through the opening parts 10a, 10b in the circuit board 10. In addition, the coil device is provided with a primary winding formed between the circuit board 10 and the core 15 in a state that it has been wound on the core 15; and a secondary winding which is formed between the circuit board 10 and the core 15 in a state that it has been wound on the core 15 and which is coupled electromagnetically to the primary winding. For example, windings 13, 14 formed on both faces of a circuit board 10 as conductors by a printed interconnections constitute a secondary winding, and windings 11, 12 arranged so as to be adjacent to the windings 13, 14 constitute a primary winding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin coil device mounted on a substrate.

[0002]

2. Description of the Related Art FIG. 7 shows a transformer as a conventional coil device mounted on a circuit board, where 1 is a circuit board and 2 is a transformer. The transformer 2 includes a bobbin 4 around which a winding 3 is wound, and a core 5 mounted around the bobbin 4,
Pins 6 provided on the bobbin 4 are fixed to the through holes 7 of the circuit board 1 by soldering.

[0003]

As described above, conventionally, the winding is wound around the bobbin, the core is arranged around the bobbin to assemble the transformer, and the terminals of the bobbin are inserted into the through holes of the circuit board and soldered. It was stuck in. Therefore, there is a drawback that mounting the transformer on the circuit board is complicated and, after mounting, the transformer protrudes to a considerable height on the circuit board.

Therefore, an object of the present invention is to provide a coil device which can be easily mounted on a circuit board and can be made thin.

[0005]

A coil device according to the present invention comprises a circuit board having an opening, a core composed of a plurality of core members combined so as to form a magnetic path through the opening of the circuit board, and A primary winding wound between the circuit board and the core wound around the core; and a primary winding wound between the circuit board and the core wound around the core. And a secondary winding electromagnetically coupled to the winding. The primary winding or the secondary winding may be a conductor formed on the circuit board. Further, it is preferable that the primary winding or the secondary winding is a multi-coated insulated conductive wire. Also, the primary winding or the secondary winding is preferably integrated by fusion.

[0006]

Since the coil device can be formed without sandwiching the bobbin while sandwiching the circuit board and projecting to both sides of the circuit board, the coil device can be easily and thinly mounted on the circuit board.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention applied to a transformer will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, the windings 13 and 1
Reference numerals 4 are formed on both surfaces of the circuit board 10 as conductors by printed wiring. Also, inside the windings 13 and 14, the first
Is provided in the circuit board 10 near the windings 13 and 14, and a pair of second openings 10b is formed. Adjacent to windings 13 and 14 are windings 11 and 12, respectively.
Are arranged. As shown in FIG. 3, the conductors of the windings 11 and 12 are formed by applying a triple insulating layer 18 made of an insulating tape around the outside of a linear conductor 17. The triple insulating layer 18 has a first layer 18a that is in close contact with the conductor 17, a second layer 18b that is coated on the first layer 18a, and a third layer 18c that is coated on the second layer 18b. First layer 18a, second layer 18b
And each of the third layer 18c are polyethylene, polyethylene terephthalate, polyimide, polyester,
It comprises a material selected from the group consisting of polyethers, polyacetals, polyvinyl formal, polyurethanes, epoxies and polyphenylene sulfides. Each of the spirally formed windings 11 and 12 melts an insulating resin 19 such as nylon coated on the triple insulating layer 18 by heating with electricity or heating by a heating element to bond adjacent conductors. And is integrated into a coil.

The core 15 is composed of core members 15a and 15b arranged outside the windings 11 and 12, and the core members 15a and 15b are the first and second openings 10a and 1a of the circuit board 10.
A pair of clips 16 to form a magnetic path through 0b.
Are combined by. Each of the core members 15a and 15b includes a central protrusion 15c arranged in the first opening 10a of the circuit board 10, a pair of peripheral protrusions 15d fitted in the second opening 10b, and a clip 16. There is provided a recess 15e whose end is locked.

To assemble the transformer of this embodiment, first, the windings 11 and 12 are attached to the core members 15a and 15b, respectively, and the windings 11 and 12 are attached to the windings 13 and 14 provided on both sides of the circuit board 10, respectively. 12 are abutted. Next, the clip 16 is inserted into the second opening 10b of the circuit board 10.
And insert the ends of the clip 16 into the core members 15a, 15b.
It is locked in the concave portion 15e. In this way, the core members 15a and 15b are attached to the circuit board 10 to complete the transformer shown in FIG. FIG. 4 shows a transformer circuit, in which windings 13 and 14 connected in parallel form a secondary winding, and winding 11
And 12 form the primary winding. However, which of the windings 11, 12, 13 and 14 is to be the primary winding or the secondary winding can be appropriately selected in design.

The embodiment of the present invention is not limited to the above embodiment, and can be modified. For example, as shown in FIG. 5, the core member 15a may be E-shaped and the core member 15b may be I-shaped. Further, as shown in FIG. 6, not only the outer iron type but also the inner iron type may be used, and only the winding as the conducting wire may be used. Further, the second opening 10b of the circuit board 10 may be formed as a cutout. Also, clip 1
It is also possible to use an adhesive instead of 6. Although a transformer is shown in the above example, the present invention is not limited to a transformer and can be implemented in a reactor.

[0012]

As described above, according to the present invention, since the winding and the core are directly attached to the circuit board without using the bobbin,
The thickness can be reduced, and the coil device can be easily attached from both sides of the circuit board.

[Brief description of drawings]

FIG. 1 is a sectional view of a transformer showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the transformer of FIG.

FIG. 3 is a perspective view of a winding with a part cut away.

FIG. 4 is a circuit diagram showing a transformer winding.

FIG. 5 is a sectional view showing another embodiment of the present invention.

FIG. 6 is a sectional view showing still another embodiment of the present invention.

FIG. 7 is a perspective view showing a conventional transformer.

[Explanation of symbols]

10 ... Circuit board, 10a, 10b ... Opening, 15 ...
Cores, 15a, 15b ... core members, 11-14 ... windings,

Claims (6)

[Claims] 1. A circuit board having an opening, a core composed of a plurality of core members combined so as to form a magnetic path through the opening of the circuit board, and the circuit wound around the core. A primary winding provided between the substrate and the core,
A coil device comprising: a secondary winding that is provided between the circuit board and the core while being wound around the core and that is electromagnetically coupled to the primary winding. 2. The coil device according to claim 1, wherein the primary winding or the secondary winding is a conductor formed on the circuit board. 3. The coil device according to claim 1, wherein the primary winding or the secondary winding is a multi-layer insulated wire. 4. The "claim 1" or the "claim 3", wherein the primary winding or the secondary winding is integrated by fusion.
The coil device according to. 5. The coil device according to claim 1, wherein the core is of an outer iron type or an inner iron type. 6. The coil device according to claim 1, wherein the opening of the circuit board is a hole or a notch.