JPH07161552A - Thin type coil transformer - Google Patents

Abstract

PURPOSE:To obtain a thin type coil transformer, in which man-hours can be decreased and which can be miniaturized, by insulating a coil by a polyimide coating. CONSTITUTION:A copper plate is machined, the whole surface is coated with a polyimide coating, and a coil 1 is manufactured, and the coil 1 is combined with a pair of ferrite cores 2, thus forming a thin type transformer. A coating material at the time of exposure to a temperature of 220-240 deg.C at the time of soldering must resist against the temperature, and polyimide is selected. Accordingly, an insulating plate inserted between the coils and the coil and a core can be removed, and the insulating space between the coil and the core can be decreased, thus allowing the decrease of the man-hours and miniaturization of the thin type coil transformer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer or coil used in a switching power supply or the like.

[0002]

2. Description of the Related Art An exploded perspective view of a conventional thin transformer is shown in FIG.
Shown in. This conventional example includes an E-type ferrite magnetic core 13, an I-type ferrite magnetic core 12, and a plurality of coils 11, and the coils 11 are formed by processing a copper plate. Therefore, insulating plates are required between the coils 11 and above the uppermost coil 11 and below the lowermost coil 11. The insulating plate is not shown in FIG. Further, FIG. 2 shows how the coil 11 is arranged. Since this coil 11 is a machined copper plate, a space for withstanding voltage is required between the middle leg 14 and the outer leg 15 of the E-type ferrite core 13.

[0003]

In a conventional thin transformer constructed by sequentially laminating coils formed by processing a conductive plate such as a copper plate, in order to measure insulation between each coil and between the coil and the magnetic core, It was necessary to insert an insulating plate or provide a space. For this reason, there are problems that the number of man-hours required for inserting the insulating plate is large, and the size due to the insulating plate and the space is large. In view of the above, it is an object of the present invention to provide a thin coil transformer capable of reducing the number of steps and downsizing.

[0004]

SUMMARY OF THE INVENTION The present invention is a thin coil transformer comprising a coil formed by laminating a required number of coils obtained by processing a conductive plate such as a copper plate, and a pair of ferrite magnetic cores. It is insulated with a coating.

[0005]

In the present invention, since the coil formed by processing the conductive plate such as the copper plate is insulated by the polyimide coating, it is not necessary to insert the insulating plate between the coils, and the space insulation between the magnetic core is the same as the conventional one. There is no need to provide a large size in.

[0006]

[Example] A copper plate with a thickness of 0.25 mm was processed and 3
A polyimide coating having a thickness of 0 μm to 80 μm was applied to produce a coil, which was combined with a pair of ferrite magnetic cores to form a thin transformer. FIG. 1 shows how the coils are arranged at this time. The spatial distance between the coil 1 and the ferrite magnetic core 2 was 0.3 mm. This spatial distance has conventionally been 0.8 to 1.5 mm. In addition, this embodiment is configured without inserting an insulating plate or the like between the coils, and the magnetic core dimensions are 20 mm in length, 14 mm in width, and 5 mm in height.
EI type ferrite core of 0.25t × 4
A 4-μH10A choke coil was formed by laminating four copper plate coils each having a width of 1 mm and having one turn and connected in series. However, a choke coil having no problem in practical use could be formed. The reason why the polyimide coating is selected in this example is as follows. 220 ° C to 24 ° C when soldering for parts that support surface mounting
Exposed to a temperature of 0 ° C. As the coating material of the present invention, it is necessary to withstand this temperature, and various studies have been conducted, but polyimide is practically applicable.

[0007]

According to the present invention, the insulating plates inserted between the coils and between the coil and the magnetic core can be eliminated, and the insulating space between the coil and the magnetic core can be reduced, and the man-hours of the thin coil transformer can be reduced. Reduction and miniaturization are possible.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which coils of one embodiment according to the present invention are arranged.

FIG. 2 is a plan view showing a state in which a conventional coil is arranged.

FIG. 3 is an exploded perspective view of a thin transformer.

[Explanation of symbols]

 1, 11 Coil 2, 13 E-type ferrite magnetic core 12 I-type ferrite magnetic core 14 Middle leg 15 Outer leg

Claims (1)

[Claims] 1. A thin coil transformer comprising a coil formed by laminating a required number of coils obtained by processing a conductive plate such as a copper plate, and a pair of ferrite magnetic cores, wherein the coils are insulated by a polyimide coating. A thin coil transformer.