JP2003197430A - Laminated type sheet coil and transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin and low-cost transformer that decreases heat generation due to copper loss in large-current conduction, reduces the number of components, and has high productivity. <P>SOLUTION: A plurality of circular or polygonal patterns 1 are formed continuously into a rosary shape in one piece, on the plane of thin-plate conductor material where an insulating film 2 is laminated on one side or both sides, such as a copper plate, and a core magnetic leg insertion hole 4 and terminals 5 and 6 for external extraction are provided at the inside of each pattern and both the end sections of the conductor material, respectively. The magnetic leg insertion hole 4, provided inside the folded conductor material, is inserted to a core magnetic leg 9, such as a ferrite, thus forming a two-terminal laminated type coil. According to this configuration, the height of a product is reduced, and at the same time, the plate thickness of the conductor material can be set large, to several hundred μms, thus expanding the conductor sectional area required for large-current conduction without changing the appearance of the product by a large amount. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

The present invention relates to the structure of a coil as an electronic component, a sheet type coil used in a transformer, and a transformer.

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Related Art A conventional coil or transformer as an electronic component has the following structure. (1) A structure in which a thin wire having an insulating coating on copper is wound around a bobbin provided with a core magnetic leg insertion hole a predetermined number of times, and then the core magnetic leg insertion hole is incorporated into the core magnetic leg to form a coil and a transformer. Has been done. In the case of such a structure, the thickness of the thin copper wire wound around the bobbin is set thicker as the current flowing therethrough becomes larger, and therefore the winding height is inevitably increased. Therefore, this winding height largely affects the overall height of the product, resulting in a high height. (2) A board in which copper fine wires are eliminated and a copper foil pattern is formed in a coil shape on one or both sides of a sheet-shaped printed circuit board and a core magnetic leg insertion hole is provided at the center of the coiled pattern is used as a laminated structure. In the case of a so-called sheet type coil or transformer incorporated in a core such as the above, measures such as widening the area of the copper foil pattern and increasing the thickness of the copper foil film are taken when it is desired to increase the current flowing therein. However, increasing the area of the copper foil pattern increases the outer shape of the product, which is contrary to miniaturization and is restricted. The thickness of the copper foil film formed on the printed board is generally 18
It is about μm to 70 μm, and a film thickness of 200 μm to 500 μm is required to pass a large current of several tens of amperes. For this reason, substrates having the same pattern are laminated and the patterns of the substrates are connected to each other by contact pins or through holes to be used as parallel connection. If the pattern surfaces face each other, insert an insulating sheet between them. After that, the core magnetic leg insertion holes provided on each board,
A coil and a transformer are formed in the core magnetic leg. In the case of such a configuration, the problem described in (1) above is eliminated, but contact pins and through holes are newly required to connect the substrates to each other, so that the manufacturing process is inefficient and the connection in this portion is not connected. There is a problem that a defect due to completeness is likely to occur and that an insulating sheet needs to be inserted in an assembling process.

[0003]

SUMMARY OF THE INVENTION The present invention provides a contact pin, a through hole, and an insulating sheet for connecting a copper foil pattern between small and thin substrates which are small in size and thin so that heat generation due to copper loss when a large current is applied is reduced. The purpose is to provide a sheet type coil and a transformer that are not required.

[0004]

[Means for Solving the Problems] In order to solve the above problems,
The present invention uses a thin conductor material having a thickness of several hundreds of μm, which is obtained by laminating an insulating film on one side or both sides in advance, and uses a plurality of circular or polygonal patterns on the plane and a core such as ferrite inside each pattern. A core magnetic leg insertion hole to be incorporated in the magnetic leg is provided, and this is continuously punched into a bead shape by a press or the like to be integrally formed.
Terminals for external drawing are provided at both ends of the conductor pattern. Thereafter, the joints between the patterns are alternately folded in a bellows shape so that the insides of the adjacent patterns overlap with each other to form a laminated structure. The two-terminal laminated coil is constructed by inserting the magnetic leg insertion hole provided inside the folded product into the magnetic leg such as ferrite.

According to this structure, since the insulating film is attached to the conductor surface in advance before the shape is constructed, it is not necessary to insert the insulating sheet after the lamination and the conductor plate thickness is the same as that of the conventional sheet-like printed circuit board. Since it can be made several times to several tens of times thicker than the thickness, the conductor cross-sectional area required when energizing a large current can be expanded without significantly changing the external shape of the product, and thus heat generation due to copper loss can be reduced. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which a plurality of circular patterns 1 are formed on a thin conductor material of several hundred .mu.m in which a resin insulating film 2 is previously attached to one or both sides, and A state in which a core magnetic leg insertion hole 4 of ferrite or the like is provided inside the pattern, and terminals 5 and 6 for external drawing are further provided at both ends of the conductor pattern, which are continuously punched into a beaded shape by a press and integrally formed. FIG. A material such as a copper plate having a low specific resistance and a high ductility is selected as the conductor material, and a material having a high insulating property and a high flame retardancy is selected as the insulating film material. The conductor pattern width and the conductor thickness are determined by the current-carrying current specifications, and the number of circular patterns formed is determined by the required coil inductance. In Figure 1, the pattern of 3/4 winding is 6
An example of individual arrangement is shown. FIG. 2 is a perspective view showing a state in which adjacent connecting portions 3 having a circular pattern are alternately folded into a bellows shape. In the illustrated example, the total number of turns of the coil is 4 and 1/2. FIG. 4 is a perspective view showing that the two-terminal laminated coil is formed by inserting the magnetic leg insertion hole 4 provided inside each folded pattern into the core magnetic leg 9 of ferrite or the like. It is also possible to construct a sheet type transformer by combining other sheet coils in addition to the above sheet coil. In this embodiment, an example in which an insulating film is pre-bonded to the conductor surface before the shape processing is shown, but after the shape processing, the whole may be subjected to, for example, electrodeposition coating or oxide film treatment to obtain insulation between the respective patterns. .

[0007]

According to the present invention, since the conductor plate thickness can be made several to several tens of times thicker than the conductor plate thickness of the conventional sheet-shaped printed circuit board, the conductor cross section required at the time of passing a large current can be obtained. It can be expanded without changing the external shape of the product. Therefore, since heat generation due to copper loss caused thereby can be reduced, it is possible to obtain a small and thin coil and transformer that can carry a large current. Further, an insulating film is pre-bonded to the conductor surface before performing the shape processing, or after the shape processing, the whole is subjected to, for example, electrodeposition coating or oxide film treatment so as to obtain insulation between the respective patterns. There is no need to insert a sheet material for insulation between patterns in the assembly process. Further, since the respective patterns are continuously connected, the contact pin which is conventionally required to connect the laminated patterns is not required, so that the number of parts can be reduced and the number of assembling steps can be simplified.

[0008]

[Brief description of drawings]

FIG. 1 shows six 3/4 circular patterns 1 and a core magnetic leg insertion hole 4 inside the pattern on a thin conductor material of several hundred μm, which is made by pasting resin insulation films 2 on both sides. FIG. 3 is a plan view showing a state in which terminals 5 and 6 for external extraction are further provided at both ends of the conductor pattern and are continuously punched into a beaded shape by a press or the like to be integrally formed.

FIG. 2 is a perspective view showing a state in which adjacent connecting portions 3 having a circular pattern are alternately folded into a bellows shape.

FIG. 3 shows a part of the side cross section of FIG.

FIG. 4 is a perspective view showing that a two-terminal laminated coil is formed by inserting a magnetic leg insertion hole 4 provided inside each folded pattern into a core magnetic leg 9 made of ferrite or the like.

FIG. 5 is an example showing that a part of the plurality of conductor patterns shown in FIG. 1 is extended and a third external lead terminal is provided.

[Explanation of symbols]

1 Thin plate conductor pattern 2 insulation film 3 Connection between each pattern 4 core magnetic leg insertion hole 5,6,7 External drawing terminal 8 Ferrite core 9 core magnetic legs

Claims (2)

[Claims] 1. A plurality of circular or polygonal patterns and a core magnetic leg insertion hole are provided inside each pattern on a flat surface of a thin conductor material obtained by laminating an insulating film on one side or both sides, and these are continuously arranged in beads. Integrally formed into a shape. A sheet-type coil or a transformer, characterized in that the adjacent patterns are alternately folded into a bellows-like structure at the joints between the patterns to form a laminated structure, which is then inserted into the magnetic legs of the core. 2. A sheet-type coil or a transformer, characterized in that the insulating film according to claim 1 is abolished and a thin film conductor material is entirely coated with a coating film or an oxide film for insulation.