JP2000260621A - Stacked type common mode choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the height of a coil by forming the coil by a method wherein a spiral conductor pattern of a specified number of turns is formed on an insulating layer and then stacking a plurality of such insulating layers and connecting them via through holes. SOLUTION: Green sheets 21, 12, 22, 13 to be stacked are formd with conductor patterns 41, 32, 42, 33 and individual through holes 1, 6, 2, 7, respectively. One end of the conductor patterns 32, 42, 33 is formed into a through hole. These through holes formed at one end of the conductor patterns 32, 42, 33 are connected to through holes 1, 6, 2 in lower layers. The other end of the conductor patterns 32, 42, 33 is formed into a land for a through hole. The individual through holes 1, 6, 2, 7 are connected to the lands for a through hole of the conductor patterns 11, 21, 12, 22. After stacking green sheets 23, 14, 24, the conductor patterns 31, 32, 33, 34 are connected via the through holes 1, 2, 3 to form a coil of about eight turns and the conductor patterns 41, 42, 43, 44 are connected via the through holes 6, 7, 8 to form a coil of about eight turns.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a common mode choke coil used for countermeasures against noise of various electronic devices, and to a laminated structure thereof.

[0002]

2. Description of the Related Art Conventionally, there is a laminated common mode choke coil disclosed in Japanese Utility Model Publication No. 7-5932. In this conventional example, a substantially one-turn annular conductor pattern having a start end and an end is formed to form a first conductor.
A laminated coil having a structure in which a substantially rectangular magnetic material sheet for a first coil and a similar magnetic material sheet for a second coil constituting a coil are alternately laminated is described.

According to the conventional example, it is described that a magnetic flux that cancels each other is generated in two coils, and the two coils function as a common mode choke coil to be effective.

[0004]

The common mode choke coil has various uses, but in recent years, a common mode choke coil having a high impedance has been required. If this high impedance common mode choke coil is manufactured with the above-described conventional structure, it is necessary to increase the number of layers. However, when the number of laminations is increased, the manufacturing cost increases, the chances of process failures such as printing misalignment and lamination misalignment increase, and there is a risk that the quality may deteriorate, and furthermore, there is a problem that the product dimensions are increased. .

[0005] In view of the above, it is an object of the present invention to provide a laminated common mode choke coil capable of producing a high impedance coil without increasing the number of laminated layers and capable of reducing the height. .

[0006]

According to the present invention, a spiral conductive pattern of 1.5 turns or more is formed on an insulating layer, a plurality of such insulating layers are laminated, and the first conductive layer is connected through a through hole to form a first conductive pattern. Forming a spiral conductor pattern of 1.5 turns or more on the insulating layer, laminating a plurality of the insulating layers, connecting them through through holes to form a second coil, A laminated common mode choke coil characterized in that insulating layers for a first coil and insulating layers for a second coil are alternately laminated.

Further, the present invention is characterized in that the positions of the through holes are aligned on a straight line which is substantially equally divided into upper and lower parts in the longitudinal direction when the laminated body is viewed from above in the laminating direction. Mode choke coil.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, since a spiral conductive pattern of 1.5 turns or more is used for an insulating layer, a multi-turn coil can be formed without increasing the number of layers.
Preferably 2 turns, and preferably 1.5 turns
0.5 turn or more every turn (1.5, 2.0,
2.5 and 3) are preferable.

Further, in the present invention, as a common mode choke coil, the impedance balance between the first coil and the second coil is improved in order to obtain excellent characteristics. This is obtained by equalizing the line length, the magnetic path length, and the magnetic path cross-sectional area of each coil, thereby providing a good coupling coefficient and a noise suppression component for a differential mode signal.
It is possible to minimize the shift in signal timing, prevent the occurrence of skew, and obtain a laminated common mode choke coil having excellent noise removal characteristics.

[0010]

FIG. 1 is a block diagram showing the internal pattern of an embodiment according to the present invention. FIG. 2 is a perspective view of this embodiment. In this embodiment, a Ni-Cu-Zn ferrite material is kneaded with a solvent or the like to form a paste, which is formed into a sheet by a doctor blade to form a green sheet. A conductive paste mainly composed of Ag is formed on the green sheet by screen printing, appropriately laminated, and integrally fired to form a laminated common mode choke coil. Usually, a plurality of pieces are simultaneously printed, laminated, divided, and fired. In addition, after printing and baking electrodes as external terminals, nickel, solder plating or the like is applied.

The laminated structure of this embodiment will be described.
On the lower green sheet 11, a conductor pattern 31 of about two turns is formed. One end of the conductor pattern 31 faces the side surface and is connected to the external terminal 52. The other end of the conductor pattern 31 is a land for a through hole. The green sheet 21 laminated thereon has
The through hole 1 independent of the conductor pattern 41 of about two turns is formed. One end of the conductor pattern 41 faces the side surface and is connected to the external terminal 51. The other end of the conductor pattern 41 is a land for a through hole. In addition, the independent through-hole 1 has the conductor pattern 3
It is connected to one through hole land.

On the green sheet 12 laminated thereon, a through hole 6 independent of the two-turn conductor pattern 32 is formed. One end of the conductor pattern 32 is a through hole, is connected to the through hole 1 of the lower layer 21, and the other end is a land for a through hole. The independent through holes 6 are connected to lands for through holes of the conductor pattern 41.

On the green sheet 22 laminated thereon, a through hole 2 independent of a two-turn conductive pattern 42 is formed. One end of the conductor pattern 42 is a through hole, is connected to the through hole 6 of the lower layer 12, and the other end is a land for a through hole. The independent through holes 2 are connected to lands for through holes of the conductor pattern 32.

On the green sheet 13 laminated thereon, a through hole 7 independent of the two-turn conductor pattern 33 is formed. One end of the conductor pattern 33 is a through hole, is connected to the through hole 2 of the lower layer 22, and the other end is a land for a through hole. The independent through holes 7 are connected to lands for through holes of the conductor pattern 42.

Similarly, green sheets 23, 14,
24, and a green sheet for protection is laminated on the green sheet 24 to form a laminate. Then, the conductor patterns 31, 32, 33, and 34 are connected by through holes 1, 2, and 3, and approximately 8
A turn coil is formed. In addition, the conductor pattern 4
1, 42, 43, and 44 are connected by through holes 6, 7, and 8, and a coil of about eight turns is formed between the external terminals 51 and 53.

The green sheets 12, 22, 13, and 23, excluding the green sheets 11, 21, 14, and 24, on which the conductive patterns connected to the external terminals are formed, have a conductor pattern of approximately two turns. In these structures, as shown in the green sheet 12 shown in FIG. 3, for example, the independent through hole 6, the through hole 32a at one end of the conductor pattern 32, and the land 32b for the through hole at the other end of the conductor pattern 32 are aligned in a straight line. Are arranged so as to form a two-turn structure. Also, this straight line
In the figure, it is on a line that bisects the green sheet up and down. With this structure, it is possible to obtain a multilayer common mode choke coil having a high impedance and a good balance between the impedances of the primary and secondary coils.

[0017]

According to the present invention, a coil having a high impedance can be manufactured without increasing the number of layers, a low profile can be achieved, and a layer having a good balance between the impedances of the primary and secondary coils can be obtained. Type common mode choke coil can be obtained.

[Brief description of the drawings]

FIG. 1 is an internal structural diagram of one embodiment according to the present invention.

FIG. 2 is a perspective view of one embodiment according to the present invention.

FIG. 3 is a pattern diagram of one embodiment according to the present invention.

[Explanation of symbols]

1, 2, 3, 6, 7, 8 Independent through holes 11, 12, 13, 14, 21, 22, 23, 24 Green sheets 31, 32, 33, 34, 41, 42, 43, 44 Coil conductor Pattern 51, 52, 53, 54 External electrode

Continuation of the front page (72) Inventor Shunichi Nishiyama 5200 Sankajiri, Kumagaya-shi, Saitama F-term in the Magnetic Materials Research Laboratory, Hitachi Metals Co., Ltd. 5E070 AA01 AB01 BA12 BB03 CB03 CB13 CB17 CC01 DA15 EA01

Claims (2)

[Claims] A spiral conductor pattern of 1.5 turns or more is formed on an insulating layer, a plurality of such insulating layers are laminated, and connected via through holes to form a first coil. A spiral-shaped conductor pattern of 1.5 turns or more is formed thereon, a plurality of the insulating layers are stacked, and connected via through holes to form a second coil.
A laminated common mode choke coil characterized in that insulating layers for the above-mentioned coil and insulating layers for the second coil are alternately laminated. 2. The position of the through holes, wherein the positions of the through holes are aligned on a straight line that divides the upper and lower portions in the longitudinal direction substantially equally when viewed from above in the stacking direction.
The described laminated common mode choke coil.