JPH0536537A - Transformer - Google Patents

Abstract

PURPOSE:To provide the title thin type transformer without using a bobbin. CONSTITUTION:The title transformer is composed of a case body 10 having a magnetic protrusion 12 in the central part thereof, a primary side insulating film 16 contained in the case body 10 and on whose surface a primary coil 18 comprising a conductor pattern is formed as well as having the first hole 20 to be engaged with the protrusion 12 in the central part of the film 16, a secondary side insulating film 26 likewise contained in the case body 10 as well as having the second hole 30 to be engaged with the protrusion 12 in the central part of the film 26 and a cover body 36 fixed to the case body 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer with a magnetic core used in communication equipment and the like. In recent years, power transformers are becoming more compact and less costly, and there is a growing demand for high safety and support for automatic mounting. In response to these needs, resin-filled types with cases are often used. Is starting to appear. This resin-filled transformer has a high heat dissipation due to the resin filling, so it can be miniaturized, and does not emit smoke in the event of an abnormality during overload and is highly safe. In addition, it has the feature that it can easily comply with safety standards due to improved insulation.

On the other hand, due to the recent demand for high-density mounting, electronic parts have been switched to surface mounting type, and power supply transformers are no exception, and there is a demand for the development of transformers that can be miniaturized and can be surface mounted. ing.

[0003]

2. Description of the Related Art In a conventional general transformer, primary and secondary windings are wound on a bobbin and integrally molded with epoxy resin or the like. Then, a pair of E-type or EI-type magnetic cores are inserted into the bobbin to form a closed magnetic circuit, and the transformer is completed. Terminals are fixed to the printed wiring board by reflow soldering and are mounted on a plane.

[0004]

However, the conventional transformer as described above requires a winding work for winding a copper wire around a bobbin, and since it is manufactured integrally by molding with epoxy resin or the like, it is small in size. There is a problem that it is difficult to reduce the cost and cost.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a transformer suitable for thinning without using a bobbin.

[0006]

In order to achieve the above-mentioned object, according to the present invention, a box body having a magnetic protrusion in the center and a primary winding formed of a conductor pattern is formed on the surface thereof. A primary side insulating film housed in the box having a first hole that fits in the protrusion in the central portion, and a secondary winding formed of a conductor pattern on the surface thereof, There is provided a transformer including a secondary insulating film housed in the box body having a second hole that fits into the protrusion, and a lid body fixed to the box body.

[0007]

Since the primary side winding and the secondary side winding are formed by the conductor pattern formed on the insulating film, the bobbin conventionally required for winding the copper wire can be omitted,
The transformer can be made thinner. Primary winding and 2
Since the next winding can be formed by printing, a troublesome winding process is not required, and the transformer manufacturing can be facilitated and the cost can be reduced.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, referring to FIG. 1, there is shown an exploded perspective view of an embodiment of the present invention, in which 10 is a magnetic box formed of a magnetic material such as ferrite or permalloy, and a magnetic material projection 12 is integrally formed at the center thereof. It is provided in. further,
Four grooves 1 for inserting terminals are provided on the opposite side walls of the magnetic box 10.
4 are formed.

Reference numeral 16 is a primary side insulating film, on the surface of which a primary winding 18 consisting of a conductor pattern is formed,
A hole 20 that fits into the protrusion 12 of the magnetic box 10 is provided at the center. Terminals 22 and 24 are connected to the primary winding 18. Reference numeral 26 denotes a secondary side insulating film, a secondary winding 28 made of a conductor pattern is formed on the surface thereof, and a hole 30 for fitting with the projection 12 of the magnetic box 10 is provided at the center. Terminals 32 and 34 are connected to the secondary winding 28.

Referring to FIG. 3, there is shown a detailed view of the primary winding, in which a spiral conductor pattern 18a is formed by printing on an insulating film 16a having a hole 20 in the center thereof. The conductor pattern 18a is connected to the terminal 22 at the outer end thereof. Similarly, a hole 20 in the center
The spiral conductor pattern 18b is also formed on the insulating film 16b formed with. And the conductor pattern 1
8b is connected to the terminal 24 at its outer end.

Further, the spiral conductor pattern 18a on the insulating film 16a and the spiral conductor pattern 18b on the insulating film 16b are respectively the conductor patterns 18a,
Leads 38 are connected at points a and b on the innermost periphery of 18b.

The conductor pattern 18a is formed in the counterclockwise direction from the outer peripheral side to the inner peripheral side, and the conductor pattern 18b is also formed in the counterclockwise direction from the inner peripheral side to the outer peripheral side. In this way, by forming the two spiral conductor patterns 18a and 18b in the same direction when viewed from the direction of current flow, the two conductor patterns 18a,
A primary winding can be formed by 18b. The secondary winding is similarly configured.

The connection between the conductor patterns 18a and 18b is
In practice, it is desirable to embed the conductor 40 in the through hole of the insulating film 16a as shown in FIG. 4 and connect the conductor 40 and the conductor pattern 18b on the insulating film 16b by thermocompression bonding. Alternatively, the through holes of the insulating film 16a may be filled with a conductive adhesive to connect the conductor patterns 18a and 18b.

Referring again to FIG. 1, first, the holes 30 of the secondary side insulating film 26 are fitted into the protrusions 12 of the magnetic box 10 and the terminals 32 and 34 are inserted into the grooves 14, so that the secondary side insulating film 26 is inserted. 26 is housed in the magnetic box 10. Then 1
Similarly, the secondary insulating film 16 is housed in the magnetic box 10.
A magnetic lid 36 made of ferrite, permalloy or the like is covered, and the magnetic lid 36 is fixed to the magnetic box 10 with an adhesive. Then, the terminals 22, 24, 32, 34 are bent into a desired shape to complete a transformer as shown in FIG.

In the above-mentioned embodiment, two insulating films are stacked to form the primary winding or the secondary winding, but the number of insulating films can be arbitrarily set according to the required number of windings. You can select it.

Further, in the above-mentioned embodiment, the box 10 and the lid 36 are made of a magnetic material, but the present invention is not limited to this, and at least only the central protrusion 12 is made of a magnetic material, The box 10 and the lid 36 may be made of a material other than a magnetic material. But in this case,
Performance as a transformer deteriorates.

[0017]

As described above in detail, according to the present invention, since the primary winding and the secondary winding are composed of the conductor pattern printed on the insulating film without using the bobbin, the transformer can be made thinner. Has the effect that it is possible. Further, since a troublesome winding process is not required, it is possible to realize easy transformer manufacturing and cost reduction.

[Brief description of drawings]

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

FIG. 2 is a perspective view of an embodiment of the present invention.

FIG. 3 is a detailed view of a primary winding.

FIG. 4 is a detailed view of a winding connection portion.

[Explanation of symbols]

10 magnetic box 12 Magnetic protrusion 16 Primary insulation film 18 primary winding 22, 24, 32, 34 terminals 26 Secondary insulating film 28 Secondary winding 36 Lid

Claims (3)

[Claims] 1. A box body (1) having a magnetic protrusion (12) in the center thereof.
0) and a primary winding (18) formed of a conductor pattern on the surface of the box body (10) having a first hole (20) in the center for fitting with the protrusion (12). Primary-side insulating film housed inside
The box body (10) having a secondary winding (28) formed of a conductor pattern on its surface and a second hole (30) fitted in the protrusion (12) in the center thereof. ) Secondary insulating film housed in
A transformer (26) and a lid (36) fixed to the box (10). 2. The primary side and secondary side insulating films (16,
26. The transformer according to claim 1, wherein 26) is constituted by stacking a plurality of insulating films each having a spiral conductor pattern formed thereon and connecting the conductor patterns formed on each insulating film. 3. The transformer according to claim 1, wherein the box body (10) and the lid body (36) are made of a magnetic material.