JPH05315153A - Laminated coil - Google Patents

Abstract

PURPOSE:To provide the high connection reliability of a coil conductor and thin and miniaturize a laminated coil. CONSTITUTION:Coil conductors 20a and 20b are formed on the both sides of an insulating sheet 14. The insulating sheet 14 is provided with a through hole 18, which is for connecting the edges of the coil conductors 20a and 20b, and a hole 16, which is for inserting a magnetic core. The insulating sheet 14 and other insulating sheet provided with a hole for inserting the magnetic core are alternately laminated and the other edges of the coil conductors 20a and 20b are taken out to the outside of the insulating sheet 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated coil,
In particular, it relates to a laminated coil used in various electronic circuits such as a switching transformer.

[0002]

2. Description of the Related Art Conventionally, a laminated coil is formed by laminating a plurality of insulating sheets each having a spiral coil conductor formed on its surface.
It was manufactured by connecting the respective coil conductors in series through through holes provided in the insulating sheet.

[0003]

However, when the number of insulating sheets increases, the connection of the coil conductor by the through hole becomes uncertain, and there is a problem that the resistance value is likely to increase at the connection portion of the coil conductor.

On the other hand, as a laminated coil, it has been proposed to solve the above-mentioned problem by producing a lead-out portion of a coil conductor without using a through hole and connecting the lead-out portions in an overlapping manner. There is. Although this method is excellent in that the laminated coil is easy to manufacture, highly reliable, and low in cost, it is not suitable for thinning or miniaturizing the laminated coil itself.

Therefore, a main object of the present invention is to provide a laminated coil in which the connection reliability of the conductor for the coil is high and the overall device can be made thin and compact.

[0006]

SUMMARY OF THE INVENTION According to the present invention, coil conductors are formed on both surfaces of the coil conductor, through holes are provided for connecting one ends of the coil conductors, and a magnetic core is inserted. An insulating sheet having a hole for, and another insulating sheet having a hole for inserting the magnetic core are alternately laminated, and the other end of the coil conductor is drawn to the outside of the insulating sheet. It is a laminated coil.

[0007]

Since one end of each of the two coil conductors is directly electrically connected through the through hole, and the other end of the coil conductor is directly electrically connected outside the insulating sheet. , There is little increase in resistance value due to connection. Therefore, the connection reliability of the coil conductor is high.

Further, since one end of each coil conductor is connected through the through hole of the insulating sheet between them, the coil sheet is drawn out near the hole for inserting the magnetic core in the insulating sheet. It is not necessary to provide a section.
Therefore, it is possible to reduce the thickness and size of the laminated coil. In addition, it is not necessary to provide a cutout or the like in the magnetic core, and the loss due to the core does not increase.

[0009]

In the laminated coil according to the present invention, the connection reliability of the coil conductor is high. Moreover, the laminated coil according to the present invention can be made thin and compact, and the loss due to the magnetic core is small.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0011]

1 is an exploded perspective view showing an embodiment of the present invention. The laminated coil 10 includes a laminated body 12. The laminated body 12 is formed by stacking, for example, a plurality of rectangular insulating sheets as an insulator. As the insulating sheet, for example, a polyimide substrate having a thickness of 25 μm is used.

In this embodiment, a plurality of insulating sheets to be laminated are formed in the same manner, and a conductor for a coil or the like is similarly formed on one insulating sheet of each set to be laminated. The set of insulating sheets and the like that will be described will be described in detail.

The upper insulating sheet 14 of the set of insulating sheets to be laminated is, for example, as shown in FIG.
A rectangular hole 16 is formed in the center thereof, for example. This hole 16 is for inserting the magnetic core there. Further, in the insulating sheet 14, for example, a rectangular through hole 18 is formed near the hole 16. This through hole 18 is provided with coil conductors 20a and 20 to be described later.
Used when connecting one end of b.

On one main surface of the insulating sheet 14, around the hole 16, for example, a spiral coil conductor 20a.
Is formed. In this case, one end of the coil conductor 20a is formed to have a large width so as to close the through hole 18. Further, the other end of the coil conductor 20 a is formed to extend to one end of the insulating sheet 14.

Further, for example, eight lead-out portions 22 are formed on one main surface of the insulating sheet 14. The four lead-out portions 22 are formed so as to project outward from one end of the insulating sheet 14, and the other four lead-out portions 22 are formed so as to project outward from the other end of the insulating sheet 14. One lead-out portion 22 at one end of the insulating sheet 14
Is formed by extending from the other end of the coil conductor 20a,
It is used as the conductor lead-out portion 24a. Further, the other seven drawer portions 22 are used as dummy drawer portions 26a. In addition, these lead-out portions 22 are used for the coil conductor 2
0a, and is formed on the insulating sheet 14 by a method such as etching.

A hole 16 is formed on the other main surface of the insulating sheet 14.
A spiral coil conductor 20b is formed around the coil. One end of the coil conductor 20b is formed wide so as to close the through hole 18, and the other end is formed to extend to the other end of the insulating sheet 14. The coil conductor 20b is formed so as to be opposite to the coil conductor 20a when viewed from the one main surface side of the insulating sheet 14. Then, the coil conductor 20
One ends of a and 20b are electrically connected via the through hole 18, for example, by spot welding. Further, four lead-out portions 22 are formed on the other main surface of the insulating sheet 14 so as to project from one end thereof, and four lead-out portions 2 are projected so as to project from the other end.
2 is formed. In this case, one lead-out portion 22 at the other end of the insulating sheet 14 extends from the other end of the coil conductor 20b and is used as the conductor lead-out portion 24b. The other seven drawer parts 22 are used as dummy drawer parts 26b.

The insulating sheet 14 is the insulating sheet 1.
4 is overlaid with another insulating sheet (not shown) having similar holes. No coil conductor or lead portion is formed on this other insulating sheet.

Similarly, holes for inserting the magnetic cores are formed in the other sets of insulating sheets, respectively, and one of the other sets of insulating sheets is also used for connecting the coil conductor. Through holes are formed. Further, a coil conductor having a predetermined shape, for example, a spiral shape, and eight lead portions, for example, are formed on both main surfaces of one of the other sets of insulating sheets. In this case, the shape of the coil conductor and the positions of the conductor lead-out portion and the dummy lead-out portion depend on the purpose of use of the laminated coil 10 and the like.
It is chosen to be the same as or different from that on the insulating sheet 14 shown in FIGS. 2A and 2B. The conductor for coil and the lead-out portion are not formed on the uppermost insulating sheet.

The above-mentioned dummy lead-out portion on each insulating sheet is for facilitating spot welding or the like under certain working conditions when connecting the coil conductors on each insulating sheet in series or in parallel.

The above-mentioned respective insulating sheets are laminated so that the respective drawn-out portions are overlapped with each other. In this case, one hole 28 is formed by the holes of each insulating sheet. In addition, an insulating sheet having no lead-out portion is laminated on the top. And
The overlapping drawn-out portion is bent in a direction orthogonal to the main surface of the insulating sheet. Therefore, these drawn-out portions project from the laminated body 12 to the outside.

Further, the coil conductors on the insulating sheets are electrically connected in parallel or in series by spot welding, soldering, caulking or the like at the leading end of the drawn portion. In this case, since the drawn-out portion projects to the outside of the laminated body 12, it is easy to connect the coil conductors in parallel or in series by spot welding, soldering, caulking, or the like.

The laminated body 12 is held by the magnetic core 30. The magnetic core 30 includes a flat plate portion 32, and the flat plate portion 32 is formed with a middle foot portion 34 extending upward at the center thereof, and outer foot portions 36 a and 3 extending upward at both ends thereof.
6b are formed respectively. Then, the middle leg portion 34 of the magnetic core 30 is inserted into the hole 28 of the laminated body 12, and the laminated body 12 is placed on the flat plate portion 32 of the magnetic core 30. Further, the lower surface of the plate-shaped magnetic core 38 is butted against the upper surfaces of the middle foot portion 34 and the outer foot portions 36a and 36b of the magnetic core 30. Incidentally, these magnetic cores 30 and 3
8 is formed by firing ferrite powder.

In this laminated coil 10, one end of each of the two coil conductors is electrically connected directly through only one through hole of one insulating sheet, and the other end of the coil conductor is connected. The extending lead-out portions are directly connected by spot welding, soldering or caulking. Therefore, the increase in resistance value due to connection can be reduced,
Highly reliable connection of coil conductors.

Further, since one end of the coil conductor located near the hole of the insulating sheet is connected through the through hole without providing a lead-out portion, the laminated coil can be made thin and compact. Moreover, it is not necessary to provide a cutout or the like in the magnetic core, and the loss due to the magnetic core is small.

Although the dummy lead portions 26a and 26b are formed on the insulating sheet 14 in the above-described embodiment, the dummy lead portions are formed as shown in FIGS. 3 (A) and 3 (B). It does not have to be done. In addition, even when the dummy drawer portion is provided, the number of dummy drawer portions may be changed arbitrarily.

Further, conductor lead-out portions 24a and 24b
Is provided in the width direction of the hole 16 of the insulating sheet 14 in the above-mentioned embodiment, but is formed in the longitudinal direction of the hole 16 of the insulating sheet 14 as shown in FIGS. 4 (A) and 4 (B). May be done.

[Brief description of drawings]

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

2A is a plan view showing one main surface of an example of an insulating sheet used in the embodiment shown in FIG. 1, and FIG. 2B is an example of an insulating sheet used in the embodiment shown in FIG. It is a top view which shows the other main surface.

3A is a plan view showing one main surface of another example of the insulating sheet used in the embodiment shown in FIG. 1, and FIG. 3B is a plan view showing the insulating sheet used in the embodiment shown in FIG. It is a top view which shows the other main surface of another example.

FIG. 4A is a plan view showing one principal surface of still another example of the insulating sheet used in the embodiment shown in FIG.
FIG. 3B is a plan view showing the other principal surface of still another example of the insulating sheet used in the embodiment shown in FIG.

[Explanation of symbols]

 10 Laminated Coil 14 Insulating Sheet 16 Hole 18 Through Hole 20a, 20b Coil Conductor 22 Lead Out Part 30, 38 Magnetic Core

Claims (1)

[Claims] 1. An insulating sheet having coil conductors formed on both surfaces thereof, having through holes for connecting one ends of the coil conductors, and having holes for inserting a magnetic core. And another insulating sheet having a hole for inserting the magnetic core alternately stacked, and the other end of the coil conductor is drawn to the outside of the insulating sheet.