JPH0737721A - Laminated coil - Google Patents

Abstract

PURPOSE:To provide a small laminated coil which allows easy and highly reliable connection between a plurality of coil conductors formed on a sheet. CONSTITUTION:A laminated coil 10 is provided with a sheet 12 formed of insulating material. A plurality of coil conductors 14, 16 and 18 are formed parallel to one another on the sheet 12. The coil conductors 14, 16 and 18 are covered with insulating covering material 20. The sheet 12 is bent to form a roll. Leads 14a, 14b, leads 16a, 16b and leads 18a, 18b are formed at the both edges of the coil conductors 14, 16 and 18, respectively. The lead 14b and the lead 16a are overlapped and connected. The lead 16b and the lead 18a are overlapped and connected.

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.

[0002]

2. Description of the Related Art FIG. 3 is an exploded perspective view showing an example of a conventional laminated coil which is the background of the present invention. The laminated coil 1 includes a plurality of insulating sheets 2. These insulation sheets 2
A spiral coil conductor 3 is formed on the top. Through holes 4 penetrating the insulating sheet 2 are formed at one ends of the coil conductors 3, and a plurality of coil conductors 3 are connected through the through holes 4.

[0003]

However, in such a conventional laminated coil, the work of forming the through holes in the insulating sheet is troublesome, which is one of the factors of cost increase. In particular, in a coil for a large current, it is necessary to increase the width of the coil conductor, so that the number of turns of the coil conductor formed on one insulating sheet cannot be increased. Therefore, in order to obtain a predetermined number of turns, it is necessary to increase the number of insulating sheets, which makes connection work between coil conductors difficult.

In addition, when a terminal for connecting to an external circuit is attached, the connection between the terminal and the coil conductor is also made through the through hole, but the connection by the through hole is uncertain, and the resistance value at the connecting portion is not certain. There was a problem that was likely to grow.

Therefore, a main object of the present invention is to provide a small-sized laminated coil in which a plurality of coil conductors formed on a sheet can be easily connected and the connection reliability of the coil conductors is high. That is.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a sheet made of an insulating material, a plurality of coil conductors formed on the sheet so as to be parallel to each other, and an insulating coating material formed on the coil conductor. A laminated coil in which a sheet is bent to form a plurality of coil conductors in a spiral shape, and a plurality of coil conductors are connected in series by connecting a lead-out portion from which the coil conductors are drawn to form a winding.

[0007]

By folding the sheet, a plurality of spiral coil conductors are formed. Furthermore, by connecting the lead-out portions of the coil conductors and connecting the coil conductors in series, it is possible to obtain a winding having a large number of turns. Since the coil conductors are connected at the ends of the drawn coil conductors, they can be easily connected by using methods such as spot welding, soldering, and caulking.

[0008]

According to the present invention, since the coil conductors are connected at the lead-out portion, it is not necessary to connect the coil conductors inside the sheet. Therefore, it is not necessary to form a through hole or the like, and the work of connecting the coil conductors can be easily performed. Moreover, since the coil conductors can be connected by a method such as spot welding, soldering, or caulking, the connection reliability can be improved as compared with the case where the coil conductors are connected through a through hole or the like. In addition, since there is no coil conductor connection inside the seat, there is no need for a space for connection,
The coil length can be shortened or the coil width can be expanded, and copper loss can be reduced.

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

[0010]

1 is a perspective view showing an embodiment of the present invention. The laminated coil 10 includes a sheet 12. Sheet 1
2 is formed of an insulating material such as a polyimide substrate. In this embodiment, as shown in FIG.
Are formed in a meandering shape.

A plurality of coil conductors 14, 16 and 18 are formed on one surface of the sheet 12. These coil conductors 14, 16 and 18 are formed in the longitudinal direction of the sheet 12 so as to be parallel to each other. Coil conductor 14,1
6, 18 are formed by a method such as etching or printing. Both ends of the coil conductor 14 are pulled out from the sheet 12, thereby forming lead-out portions 14a and 14b. Similarly, at both ends of the coil conductors 16 and 18,
Drawers 16a and 16b and drawer 18 respectively
a and 18b are formed.

Further, an insulating coating material 20 is formed so as to cover the coil conductors 14, 16 and 18. The sheet 12 and the insulating coating material 20 have, for example, a thickness of 2
0 μm polyimide substrate is used, coil conductor 14,
For example, copper foil having a thickness of 70 μm is used as each of 16, 18.

The sheet 12 is diagonally bent at the portions indicated by the dotted lines A, B and C. Thereby, as shown in FIG. 1, the sheet 12 is formed in a spiral shape. Correspondingly, the coil conductors 14, 16 and 18 also have a spiral shape, and windings each having three turns are formed. Then, the drawer portions 14a, 16a, 18a and the drawer portion 14b,
16b and 18b project outside the formed winding.
The drawer portion 14b and the drawer portion 16a are overlapped with each other, and the drawer portion 16b and the drawer portion 18a are overlapped with each other. These drawer parts 14b and 16a are connected, and the drawer parts 16b and 18a are connected. Connection of the drawn-out portion can be performed by a method such as spot welding, soldering, or caulking.

By connecting these lead portions, the three windings formed by the coil conductors 14, 16 and 18 are connected in series. Therefore, a winding of 9 turns is formed between the lead-out portion 14a and the lead-out portion 18b.

A laminated coil of up to several tens of turns can be formed by the same method. In this case, it suffices to adjust the number of coil conductors, the number of meandering sheets, and the number of folds. In addition, in the above-described embodiment, when forming a coil of, for example, 8 turns, the coil conductor 14 is provided in the intermediate portion 14.
The coil conductor may be formed from the lead-out portion 14a to the intermediate portion 14c by forming the lead-up portion in the intermediate portion 14c. With this configuration, the lead-out portion formed in the intermediate portion 14c and the lead-out portion 16a of the coil conductor 16 overlap each other, and these lead-out portions can be connected.

In this laminated coil 10, the coil conductor 1
Since the connection of 4, 16 and 18 is made at the lead-out portion, it is not necessary to form a through hole inside. Therefore, the work of connecting the coil conductors is simplified, and the cost can be reduced as compared with the conventional laminated coil. Further, since the drawn-out portion can be connected by spot welding, soldering, caulking, etc., the connection reliability can be improved as compared with the connection by the through hole. Furthermore, since there is no internal connection, it does not require extra space for connection,
The coil length can be shortened or the coil width can be expanded, and copper loss can be reduced.

In this laminated coil, since the coil conductor formed on the sheet is covered with the insulating coating material, the coil conductor does not short-circuit even if the sheet is bent. Further, the number of meandering or bending of the sheet can be changed depending on the number of turns of the winding formed by the coil conductor, and of course, a sheet which does not meander can be used.

[Brief description of drawings]

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

FIG. 2 is a plan view showing a sheet of the laminated coil shown in FIG. 1 and a coil conductor formed thereon.

FIG. 3 is an exploded perspective view showing an example of a conventional laminated coil which is the background of the present invention.

[Explanation of symbols]

 10 Laminated Coil 12 Sheet 14 Coil Conductor 16 Coil Conductor 18 Coil Conductor 14a, 14b Lead-out Part 16a, 16b Lead-out Part 18a, 18b Lead-out Part 20 Insulation Coating Material

Claims (1)

[Claims] 1. A sheet formed of an insulating material, a plurality of coil conductors formed on the sheet so as to be parallel to each other, and an insulating coating material formed on the coil conductor, the sheet being bent. And a plurality of the coil conductors are spirally formed, and a plurality of the coil conductors are connected in series to form a winding by connecting a lead-out portion from which the coil conductors are drawn out.