JPH0370885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a novel laminated chip coil with excellent productivity.

(Prior Art) Conventionally, there has been a laminated chip coil produced by a printing method, as disclosed in Japanese Patent Application Laid-Open No. 55-91103. This laminated chip coil is made by printing a first conductor in a desired pattern on the surface of a first ferrite paste layer printed on a film made of polyester or the like, and then exposing one end of the first conductor as a connection part. Then, the second ferrite paste layer is printed on approximately 2/3 of the surface of the first ferrite paste layer, and then the second ferrite paste layer is printed from the unprinted surface of the first ferrite paste layer. Print a desired pattern of second conductors connected to the connections of the first conductor over the surface, then expose one end of the second conductor as a connection and cover the unprinted second conductor of the second ferrite paste layer. Printing a third ferrite paste layer on the entire surface of the first ferrite paste layer and approximately 1/2 of the surface of the second ferrite paste layer,
Similarly, the conductor and ferrite paste were alternately printed a desired number of times to form a continuous coiled state, and then the printed laminate was fired.

In addition, as for other things, conventionally,
There is a laminated chip coil, as disclosed in No. 100209, etc., in which electrical connection between conductors formed on each ferrite raw sheet is made through through holes. This laminated chip coil has a first ferrite raw sheet with a U-shaped first conductor formed on its surface, a U-shaped second conductor in the opposite direction to the first conductor formed on its surface, and A second raw ferrite sheet having a conductor through hole for electrically connecting the first conductor and the second conductor is laminated on one end portion, and the second raw ferrite sheet is further rotated 180° on top of the second raw ferrite sheet. The third ferrite having the same shape was laminated, and a desired number of similar raw ferrite sheets were laminated to form a coiled continuous conductor, and then the laminated body was fired.

(Problems to be Solved by the Invention) However, the above two conventional laminated chip coils each have the following problems.

In other words, the laminated chip coil produced by the printing method is
Productivity was poor because the manufacturing process was complicated. Additionally, since the thickness of the overlapping parts of the ferrite paste layers is greater than the thickness of the non-overlapping parts, there is a limit to the number of stacked ferrite paste layers, and it is difficult to manufacture multilayer laminated chip coils that exceed this limit. It was impossible.

On the other hand, in a laminated chip coil in which electrical connections between conductors formed on each raw ferrite sheet are made through through holes, it is difficult to connect the insides of the through holes with the conductors.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and as a means thereof, the laminated chip coil of the present invention has a plurality of ferrite sheets laminated with a ring conductor formed on at least one surface, and the laminated body is A cut is provided to divide the annular conductor of each ferrite sheet from one side to the center, and at least one of the two divided sides is shifted along the lamination direction by the cut. As a result, one end of the annular conductor of a particular ferrite sheet is electrically connected to the other end of the annular conductor of another ferrite sheet located on one side of that ferrite sheet, and the other end of the annular conductor of that ferrite sheet is It was configured to be electrically connected to one end of the annular conductor of yet another ferrite sheet located on the other side.

(Description of Embodiment) An embodiment of the laminated chip coil of the present invention will be described below with reference to the drawings.

First, prepare an arbitrary number of raw ferrite sheets 2 having ring-shaped conductors 1 formed on one surface as shown in FIG. Ferrite raw sheet 2'
Prepare one sheet. As a method for forming the annular conductor 1 on the ferrite raw sheet 2 or 2', there is a method of printing a conductor paint in a ring shape on the surface of the ferrite raw sheet 2 or 2' to form the annular conductor 1, or a method of preparing a base film, A ferrite green sheet 2 or 2' on which an annular conductor 1 is formed is obtained by printing a conductor paint in a ring shape on the base film, applying a ferrite paste, drying this, and then peeling it off from the base film. You can use any method to obtain it. In the latter method, in order to form the annular conductor 1 on both sides of the raw ferrite sheet 2', the ferrite paste is applied to the base film on which the conductor paste is printed in an annular shape, and then the conductor paste is further applied on top of the base film. It is necessary to overlay another base film printed in a circular shape.

Next, as shown in FIG. 2, an arbitrary number of raw ferrite sheets 2 and one raw ferrite sheet 2' are placed so that the annular conductor 1 is exposed on both end surfaces, with the raw ferrite sheet 2' at one end. The laminates are arranged so as to face each other, stacked, and pressed together to obtain a laminate 3.

Next, as shown in FIG. 3, a cut 4 is provided from one side of the laminate 3 to the center so as to divide the annular conductor 1 of each ferrite raw sheet 2 and 2'.

Next, as shown in FIG. 4A, at least one of the side surfaces of the laminate 3 divided into two parts by the notch 4 is shifted, and the laminate 3 is pressed and crimped in the shifted state. As a result, one end of the annular conductor 1 of a specific ferrite raw sheet 2 to 2' is electrically connected to the other end of the annular conductor 1 of another ferrite raw sheet 2 to 2' located on one side thereof. ,
The other end is electrically connected to one end of the annular conductor 1 of the other green ferrite sheet 2 to 2' located on the other side. However, one end of the annular conductor on one surface of the raw ferrite sheet 2' is electrically connected to the other end of the annular conductor on the other surface.

FIG. 4B is an exploded perspective view of a main part of the laminate 3 shown in FIG. 4A, and is for explaining the electrical connection state of the annular conductor. 21, 22, and 23 are raw ferrite sheets laminated in order, and a ring-shaped conductor 11 having one end 11a and the other end 11b is formed on the surface of the raw ferrite sheet 21. An annular conductor 12 having one end 12a and the other end 12b is formed on the surface, and the surface of the ferrite raw sheet 23 has one end 13a and the other end 13.
An annular conductor 13 having a diameter b is formed. The other end 11b of the annular conductor 11 is electrically connected to one end 12a of the annular conductor 12, and the other end 12b of the annular conductor 12 is electrically connected to one end 13a of the annular conductor 13.

This crimping process is performed while measuring the electrical resistance value between the annular conductors 1 exposed at both ends of the laminate.
At least one of the side surfaces of the laminate 3 divided into two by the cut 4 may be adjusted and shifted so that its electrical resistance is minimized.

Finally, as shown in FIG. 5, external electrodes 5a and 5b are formed on both ends of the laminate 3 to complete the laminate chip coil according to the embodiment of the present invention.

The above is an embodiment of the laminated chip coil and the method for manufacturing the same according to the present invention, and it goes without saying that the design can be changed without departing from the spirit of the present invention. For example, in this embodiment, the annular conductor 1 has a circular shape, but the shape of the annular conductor 1 is arbitrary and is not limited to this, and may be an ellipse, a square, or the like. Further, the overall shape is also arbitrary, and is not limited to the quadrangular prism shape as in this embodiment, but may be a cylindrical shape as shown in FIG. 6, or other shapes.

(Effects of the Invention) As is clear from the above explanation, the present invention provides a multilayer chip coil with excellent productivity, which is completely different from the conventional structure. Obtainable.

[Brief explanation of drawings]

FIGS. 1A and 1B are perspective views showing a raw ferrite sheet used in a laminated chip coil according to an embodiment of the present invention, and FIGS. A perspective view showing the stages in which the chip coil is manufactured.
FIG. 5 is a perspective view showing a laminated chip coil according to an embodiment of the present invention; FIG.
The figure is a perspective view showing another embodiment. 1, 11, 12, 13...ring conductor, 2, 2',
21, 22, 23... Ferrite raw sheet, 3... Laminated body, 4... Notch, 5a, 5b... External electrode.

Claims (1)

[Claims] 1. A plurality of ferrite sheets each having an annular conductor formed on at least one surface are laminated, and the laminate is provided with a cut extending from one side to the center to separate the annular conductor of each ferrite sheet. Furthermore, at least one of the two divided side surfaces is shifted along the lamination direction by a cut, and as a result, one end of the annular conductor of a particular ferrite sheet is placed on one side of the ferrite sheet. The other end is electrically connected to the other end of the annular conductor of another ferrite sheet located on the other side of the ferrite sheet, and the other end is electrically connected to one end of the annular conductor of the next ferrite sheet located on the other side of the ferrite sheet. A multilayer chip coil consisting of a structure that includes physically connected relationships. 2. A step of laminating a plurality of raw ferrite sheets each having a ring-shaped conductor formed on at least one surface, a step of providing a cut to separate the ring-shaped conductor of each raw ferrite sheet from one side of the laminate to the center, and Then, at least one of the two divided side surfaces is shifted along the lamination direction, and one end of the annular conductor of a specific ferrite raw sheet is connected to the annular conductor of another ferrite raw sheet located on one side of the ferrite raw sheet. a step of electrically connecting the other end to one end of a ring conductor of another ferrite raw sheet located on the other side of the ferrite raw sheet; A method for manufacturing a laminated chip coil, comprising: a step of firing;