JPH10189342A - Common mode choke coil and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a common mode choke coil which has excellent characteristics and a method for manufacturing the coil. SOLUTION: A common mode choke coil is provided with a plurality of conductors 3, each of which is composed of a plurality of turns, with the diameters of the turns being changed toward the other end from one end and the turns being positioned in different planes, and one closed loop-like magnetic body which is provided so that the magnetic body can be shared by the conductors 3 in a nonmagnetic body 4 or on the surface of the body 4. When the choke coil is constituted in such a way, the coil can get an excellent electric characteristic, because the coil does not contain any winding composed of a covered copper wire and can constitute a closed magnetic path. In addition, the coil can be manufactured easily through a less number of processes.

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 various electronic devices and communication devices, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Common mode choke coils are widely used in various electronic devices and communication devices. In recent years, a small or thin common mode choke coil has been increasingly required.

As a conventional common mode choke coil that satisfies these demands, a ferrite core is wound with two or more insulated copper wires, and the wound coil is combined with a ferrite core to further form a closed magnetic circuit. I have. That is, in this method, after two insulating-coated copper wires are wound around the ferrite core, the ferrite core is incorporated to form a closed magnetic circuit.

[0004]

With the above configuration, there is a limit in downsizing and securing reliability, and it is difficult to completely form a closed magnetic circuit. In addition, there is a problem that productivity is poor because the winding method is used in terms of process.

The present invention eliminates the above-mentioned drawbacks of the prior art, secures excellent characteristics with a small size, does not use a coated copper wire, has a structure capable of ensuring excellent productivity, and has a high reliability. It is an object to provide a common mode choke coil and a method for manufacturing the same.

[0006]

In order to solve the above-mentioned problems, a common mode choke coil according to the present invention comprises a plurality of turns on a non-magnetic material or on a surface, and the diameter of each turn portion gradually varies from one end to the other end. At least each turn part has a plurality of conductors located in different planes,
In addition, it has one closed-loop magnetic body, and each of the conductors shares the magnetic body as a magnetic core.

According to the present invention, a common mode choke coil having excellent productivity and excellent electrical characteristics can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a plurality of turns on a non-magnetic material or on a surface, and the diameter of each turn portion is gradually different from one end to the other end and at least each turn portion is different. It has a plurality of conductors positioned in a plane, and further has one closed loop-shaped magnetic body, and each of the conductors is configured to share the magnetic body as a magnetic core, and each conductor is one Since it has a completely closed magnetic circuit configuration in which a magnetic material is shared as a magnetic core, it is easy to produce and exhibits excellent characteristics. In addition, the stray capacitance between the turn portions of the conductor can be reduced.

According to a second aspect of the present invention, a plurality of conductors are provided at positions vertically stacked on different planes,
In addition, the configuration is such that the positions of the conductors are partially overlapped, so that the productivity is excellent and the height can be reduced.

According to a third aspect of the present invention, a plurality of conductors are provided at positions vertically stacked on different planes,
In addition, since the positions of the conductors do not overlap each other, the structure is particularly excellent in productivity.

According to a fourth aspect of the present invention, a plurality of conductors are provided at positions arranged in different in-plane directions, and the positions of the conductors substantially coincide with each other. With it, it becomes excellent in productivity.

According to a fifth aspect of the present invention, there is provided one of a step of forming a hollow magnetic body having a conical or pyramid-shaped hollow portion and a step of forming a conical or pyramidal magnetic body. One or both steps, a step of forming a non-magnetic material on the inner surface of a hollow magnetic material or a side surface of a conical or pyramid-shaped magnetic material, and an inner surface, conical shape or pyramid shape of a hollow magnetic material Forming a plurality of conductors comprising a plurality of turns on a side surface or a non-magnetic material of a magnetic material, wherein the diameter of each turn portion is gradually different from one end to the other end and at least each turn portion is located in a different plane. Forming end layers on the upper and lower end surfaces of a hollow magnetic material or a conical or pyramid-shaped magnetic material, forming one closed-loop magnetic material, and each conductor having the magnetic material as a magnetic core. This is a method of manufacturing a common mode choke coil that is formed so as to be shared.It is excellent in productivity, and the obtained common mode choke coil has a closed magnetic circuit structure and small stray capacitance between each turn of the conductor. It can be.

[0013] The invention according to claim 6 includes a step of forming a hollow non-magnetic material having a conical or pyramid-shaped hollow portion, a step of forming a conical or pyramidal magnetic material, The inner surface of a hollow non-magnetic material or the side surface of a conical or pyramid-shaped magnetic material has a plurality of turns, and the diameter of each turn portion gradually changes from one end to the other end, and at least each turn portion is located in a different plane. Forming a plurality of conductors, and forming end layers on upper and lower end surfaces of a hollow non-magnetic material and a conical or pyramidal magnetic material, thereby forming one closed-loop magnetic material. Is a method of manufacturing a common mode choke coil in which each conductor is formed so as to share a magnetic material as a magnetic core,
It is a method with excellent productivity.

The common mode choke coil of the present invention comprises a plurality of conductors having a plurality of turns in a non-magnetic material or on a surface, wherein the diameter of each turn portion is gradually different from one end to the other end and at least each turn portion is located in a different plane. A common mode choke coil having a single closed-loop magnetic body, and wherein each of the conductors shares the magnetic body as a magnetic core. The shape of the conductor constituting the common mode choke coil, that is, as an example of the winding method, a conductor having a plurality of turns in a non-magnetic material, and this conductor is a circle in which the diameter of each turn gradually increases from one end to the other end. And the positions of the turn portions are located in different planes. In other words, one end of the conductor is formed as a circle with a small diameter, and a circle whose diameter gradually increases toward the other end, and each turn portion rises or falls at the end or start end and is adjacent to the next turn portion. Is connected to Therefore, each turn portion is located on the same plane, and adjacent turn portions are located on different plane portions depending on rising and falling portions, and are set to have different diameters. About 1 in the same plane
Turns, where each turn refers to a conductor present in the same plane.

Further, as another example, similarly, a solid body having a conductor composed of a plurality of turns in a non-magnetic material, and having a diameter gradually increasing from one end to the other end and located in different planes from the one end. Some have a spiral shape.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a typical common mode choke coil of the present invention. The outer magnetic body 1 is located outside the conductor 3 having a plurality of turns, and the diameter of each turn portion is gradually different from one end to the other end, and at least each turn portion is located in a different plane. The inner magnetic body 2 is located. The conductor 3 is surrounded by the outer magnetic body 1 and the inner magnetic body 2, and a non-magnetic body 4 exists around the conductor 3. Each of the conductors 3 having such a configuration is vertically stacked on a different plane on which each turn portion is located. As shown in FIG. 1, between the conductors 3 is a structure in which the conductors are stacked from the center via an inner magnetic body 2, a non-magnetic body 4, and an outer magnetic body 1. End face magnetic layers 9 and 10 are present on the upper and lower end faces. The inner magnetic body 2, the outer magnetic body 1, and the end face magnetic layers 9 and 10 existing around the conductor 3 constitute a closed-loop magnetic body inside the conductor 3. In other words, the conductors 3 share a closed-loop magnetic core composed of the magnetic material or the magnetic layer. The respective ends of the conductors 3 are connected to extraction electrodes 5, 6, 7, and 8, respectively. The extraction electrodes 5, 6, 7, and 8 are connected to end electrodes 11, 12, 13, and 14 provided on the end surfaces, respectively. It is connected.

The non-magnetic material 4 may be any material having electrical insulation, such as an organic insulating material such as glass epoxy or polyimide, or an inorganic insulating material such as glass, glass ceramics or ceramics. There may be.

The outer magnetic body 1, the inner magnetic body 2, or the end face magnetic layers 9 and 10 may be made of a generally known ferrite material having a high magnetic permeability, such as a NiZn-based or NiZnCu-based material.

Any material may be used as the material of the conductor 3 or the extraction electrodes 5, 6, 7, 8 as long as it is an electrically good conductor. However, a material having a high resistivity and a low resistance is required for the common mode choke coil. Conductive materials such as copper, silver and palladium alloys or silver are effective.

The end electrodes 11, 12, 13, and 14 may be made of a conductive material. Generally, however, it is preferable that the end electrodes are composed of not a single layer but a plurality of layers. It is necessary to consider the mounting strength at the time of mounting on the board, the wettability of the solder at the time of mounting, the solder cracking, etc. Specifically, the lowermost layer uses the same conductive material as the extraction electrodes 5, 6, 7, and 8. For the intermediate layer, nickel having resistance to solder is used, and for the outermost layer, solder or tin having good wettability to solder is used.

However, this is an example, and it is not always necessary to adopt this configuration, and a conductive resin material may be included in addition to a material having excellent conductivity such as a metal.

A predetermined wiring pattern is formed on a ceramic substrate such as alumina or ferrite, a window is provided on the ceramic substrate, and a common mode choke coil is inserted.
Since the wiring pattern and the end electrodes 11, 12, 13, and 14 of the common mode choke coil are brought into contact with each other and fired using a thick film forming process to be electrically connected, heat resistance is increased,
A configuration corresponding to this thick film forming process may be considered.

The common mode choke coil shown in FIG. 2 has a configuration in which two conductors 3 constituting the common mode choke coil shown in FIG. 1 are engaged. Although the position of the conductor 3 is different, the magnetic circuit formed by each component is the same. That is, the magnetic core shared by each conductor 3 is the outer magnetic body 1,
It comprises the inner magnetic body 2 and the end face magnetic layers 9 and 10. As shown in FIG. 2, with such a configuration, the height can be considerably reduced as compared with FIG.

The common mode choke coil shown in FIG. 3 has a configuration in which two conductors 3 constituting the common mode choke coil shown in FIG. 1 are arranged. Since the conductors 3 are arranged side by side, the magnetic core shared by the conductors 3 is composed of the inner magnetic body 2 of each conductor 3 and the end face magnetic layers 9 and 10 located on the upper and lower end faces thereof. Since the outer magnetic body 1 shown in FIG. 1 or FIG. 2 is not particularly required, the non-magnetic body 4 occupies another part as shown in FIG. In this case, as can be seen from the drawing, the configuration is simpler than that of the common mode choke coil shown in FIGS. 1 and 2, and it can be said that the component occupation area is slightly larger but the height is low and the production is easy.

In the common mode choke coil shown in FIG. 1, FIG. 2, or FIG. 3, the outer magnetic body 1, the inner magnetic body 2, or the end face magnetic layers 9, 10 may be made of the same magnetic body, respectively. It may be composed of magnetic materials having different characteristics. For example, one member may be configured with different characteristics such as magnetic permeability and magnetic flux density. By appropriately selecting the magnetic properties of each member, the inductance value of the common mode choke coil can be arbitrarily selected, and the leakage flux or the DC superimposition characteristics can be controlled freely.

FIG. 2 shows an example in which the large diameter and the small diameter of the two conductors 3 are arranged at substantially the same position and are arranged in the same direction. However, such arrangement is not always necessary. As shown in FIG. 2, by disposing the two conductors 3, the invalid area can be reduced as much as possible, and can be reduced in the left-right direction on the drawing.

The cross-sectional shape of the conductor 3 is not limited to a flat rectangular shape, and the cross-sectional area of the conductor 3 can be increased to reduce the conductor resistance and be used for a large current. In this case, as the cross-sectional shape of the conductor 3, various shapes such as a triangle, a circle, an ellipse, a semicircle, a polygon, and an oval are possible. In order to obtain the conductor 3 having such a cross-sectional shape, for example, a step-shaped step portion is provided on the inner surface of the outer magnetic body 1, and a conductive paste is applied to the step portion and dried to form the conductor 3 having a triangular cross-section. Can be realized.

Although the overall shape of the conductor 3 has been described as a circular shape, it may be a square shape or the like. In other words, a prismatic shape is originally preferred as a surface mount type common mode choke coil, and each of the columnar common mode choke coils is formed of a square turn portion and has a square shape that is full of the outer shape of the common mode choke coil. It becomes possible to form a turn part. In order to obtain such a conductor 3, for example, a pyramid-shaped hollow portion is formed in the outer magnetic body 1, and the conductor 3 is formed on an inclined surface of the hollow portion so that the inner surface of the outer magnetic body 1 has a square shape. Can be configured.

As described in the above several examples, the diameter of each turn portion gradually changes from one end to the other end in a magnetic body composed of the outer magnetic body 1 and the inner magnetic body 2 and at least each turn section has a different plane. In contrast to the conventional laminated structure or winding structure, the conductor 3 located in the vicinity is easily formed, the yield can be improved, and the neighboring turn portion is made of a non-magnetic material. , The occurrence of stray capacitance is minimized. A common mode choke coil having remarkably excellent quality and performance can be obtained.

In the above embodiment, only the surface mounting type having end electrodes 11, 12, 13, 14 provided at both ends has been described. However, pin terminals are implanted on a non-magnetic material or a magnetic material. And the end face electrode 1
Instead of 1, 12, 13, and 14, a lead-type common mode choke coil in which a cap-shaped electrode having a terminal is fitted and coupled to both ends of a non-magnetic material or a magnetic material may be used.

Next, a method of manufacturing the common mode choke coil of the present invention will be described. In the method for manufacturing a common mode choke coil according to the present invention, a step of forming a hollow outer magnetic body 1 having a conical or pyramidal hollow portion and a step of forming a conical or pyramidal inner magnetic body 2 are performed. One or both of the processes is different from that of the first embodiment in that a plurality of turns are provided inside the outer magnetic body 1 or outside the inner magnetic body 2 via the non-magnetic body 4, and the diameter of each turn portion is gradually different from one end to the other end. And a step of forming a plurality of conductors 3 in which at least each turn portion is located in a different plane, and a step of forming end face magnetic layers 9 and 10 on upper and lower end faces of the outer magnetic body 1 or the inner magnetic body 2, respectively. This is a method for manufacturing a common mode choke coil in which a single magnetic body is formed and the conductors 3 are formed so as to share the magnetic body as a magnetic core.

Further, as another method, there are a step of forming a hollow non-magnetic material 4 having a conical or pyramid-shaped hollow portion, and a method of forming a conical or pyramidal inner magnetic material 2.
Forming a plurality of turns on the inner surface of the non-magnetic member 4 or the side surface of the inner magnetic member 2, wherein the diameter of each turn portion gradually changes from one end to the other end, and at least each turn portion is located in a different plane. Forming a plurality of such conductors 3 and forming end surface magnetic layers 9 and 10 on the upper and lower end surfaces of a conical or pyramid-shaped magnetic material. This is a method of manufacturing a common mode choke coil formed so that a magnetic material is shared as a magnetic core.

As described above, although there is a difference in the manufacturing method, there is a difference in the components around the conductor 3 of the obtained common mode choke coil.
Each conductor 3 shares a closed loop magnetic body as a magnetic core.

Next, a more detailed method of manufacturing the common mode choke coil of the present invention will be described with reference to the drawings.

FIGS. 4 to 10 are sectional views showing a method of manufacturing a common mode choke coil according to the present invention in the order of steps, and show a method of manufacturing the common mode choke coil shown in FIG. First, as shown in FIG. 4, a hollow non-magnetic member 4 having a conical or pyramid-shaped hollow portion 15 formed therein.
To form

Next, as shown in FIG. 5, the conductor 3 is formed on the entire inner surface of the non-magnetic material 4, and as shown in FIG.
Is patterned in a three-dimensional spiral shape. The pattern of the conductor 3 includes a plurality of turns, and the diameter of each turn portion gradually changes from one end to the other end, and at least each turn portion is located in a different plane.

As the shape of the conductor 3, as described above, there is a shape in which the center portion of the mosquito coil-shaped conductor 3 is pulled down to form a trumpet shape or a series of concentric circles.

As for the shape of the inner surface of the non-magnetic material 4, the conductor 3 can be formed from a plurality of turns as described above, even if it has a stepped slope other than a simple conical or pyramidal surface as shown in FIG. What is necessary is just to form on this inner surface so that the diameter of each turn part may gradually change from one end to the other end, and at least each turn part may be located in a different plane. In the case of a step-like slope instead of a simple slope, for example, when the conductor 3 is formed at the corner of the step, the whole is composed of a plurality of turns, and the diameter of each turn portion gradually increases from one end to the other end. The conductors 3 are formed so as to be different and at least each turn portion is located in a different plane. As a method of forming the hollow non-magnetic material 4 having the above-described step-shaped inner surface, a slurry-like non-magnetic material is flowed on a support having a convex portion capable of meshing with the inner surface, and the dried non-magnetic material is dried. By separating from the support, the specific hollow portion 1
5 can be formed. As another method, as described above, a non-magnetic material in a slurry state is poured on a flat support to form a smooth non-magnetic material in a sheet form, and then the above-described predetermined hollow portion 15 is formed. This is a method of forming a specific hollow portion 15 in a non-magnetic material using a mold having a shape.
Furthermore, the hollow non-magnetic material 4 having the specific hollow portion 15 can be similarly formed by a generally known powder molding method.

Next, as shown in FIG. 7, on the bottom surface of the non-magnetic material 4 on which the conductors 3 are formed, extraction electrodes 6 and 8 which can respectively join the conductor ends of the two conductors 3 on the smaller conductor diameter are formed in advance. The thus-formed end face magnetic layer 10 is joined.

Further, as shown in FIG. 8, a magnetic material is filled in the hollow portion 15 formed by the non-magnetic material 4 and the end face magnetic layer 10 to form the inner magnetic material 2.

Next, as shown in FIG. 9, the end face magnetic layer 9 in which the lead electrodes 5 and 7 which can be joined to the conductor end of the conductor 3 on the side of the larger conductor diameter are formed on the non-magnetic material 4 It is joined to the end face of the body 2.

Further, as shown in FIG. 10, end electrodes 11, 12, 13, and 14 are formed on the end surfaces of the chip-shaped component. By firing the obtained laminate, a common mode choke coil can be obtained. But,
The firing may be performed without forming the end face electrodes 11, 12, 13, and 14. That is, the end face electrodes 11, 12, 13, 14
Is fired, and the end face electrode 1 is fired after firing.
1, 12, 13, and 14 are formed. An example of a formation method in this case will be described. A conductor layer is formed in the same shape as the end face electrodes 11, 12, 13, and 14 shown in FIG. Thereafter, nickel plating and solder or tin plating are performed using the conductor layer as an electrode. Finally, the end face electrodes 11, 12, 13, and 14 have a three-layer structure of a base conductor layer formed by firing and nickel and solder or tin formed by electroplating.

The non-magnetic material 4, the inner magnetic material 2, and the end face magnetic layers 9 and 10 are formed by a generally known green sheet molding method, printing method, dipping method, powder molding method, spin coating method or the like. be able to. The conductor 3 or the extraction electrodes 5, 6, 7, and 8 are generally printed by a printing method, such as a method of forming a pattern using a laser, a method of transferring a conductor previously formed into a predetermined shape by a mold, or the like, dropping, potting, or spraying. It may be a method such as a method.

The common mode choke coil obtained by the manufacturing method of the present invention is a common mode choke coil having excellent heat resistance, so that it can be easily modularized.
For example, a predetermined wiring layer is formed on a ceramic substrate such as an alumina substrate or a ferrite substrate, and the wiring of the substrate and the end electrodes 11, 12, 1 of the common mode choke coil are formed.
Connection with 3, 14 can be performed at the same time to integrate or assemble. In this case, a window is opened at a predetermined position on the substrate, and the end surface electrodes 11, 1 on the side surfaces of the common mode choke coil are opened.
Since it becomes possible to connect the wirings 2, 13, and 14 to the wiring on the ceramic substrate, a thin module can be obtained. In this case, an ordinary thick film forming process using a generally known ceramic substrate can be applied. The end electrodes 11, 12, 13, and 14 of the common mode choke coil are not premised on soldering, but may be fired and electrically connected.

The two terminals of the conductor 3 forming the above-mentioned coil are formed on the end surface of the chip component to form the end surface electrodes 11, 1
2, 13 and 14 are electrically connected. That is, the end face electrodes 11 and 1
Extraction electrodes 5 for electrically connecting to 2, 13, 14
6, 7, 8 and end face electrodes 11, 12, 13, 14
Is connected to

The paste for forming each of the above layers is as follows:
Solvents such as butyl carbitol, terpineol, and alcohol, binders such as ethyl cellulose, polyvinyl butyral, polyvinyl alcohol, polyethylene oxide, and ethylene-vinyl acetate; and sintering aids such as various oxides and glasses. In addition, a plasticizer or a dispersant such as butylbenzyl phthalate, dibutyl phthalate, and glycerin may be added.
Each layer is formed using a kneaded material obtained by mixing these. A common mode choke coil is obtained by firing those laminated in a predetermined structure as described above. When producing a green sheet, various solvents having excellent evaporability in place of the above-mentioned solvent, for example, butyl acetate, methyl ethyl ketone,
Desirable are toluene and alcohol.

The firing temperature range is from about 800 ° C. to 13
It is in the range of 00 ° C. In particular, it depends on the conductor material. For example, when silver is used as the conductor material, it is necessary to be around 900 ° C., and at 950 ° C. for an alloy of silver and palladium, and nickel / palladium is used as the conductor material for firing at a higher temperature .

[0048]

Next, more specific embodiments of the present invention will be described.

(Example 1) Composite type glass powder 10 obtained by mixing alumina powder and crystallized glass powder
2 g of ethyl cellulose and 20 g of α-terpineol were mixed with 0 g, and kneaded using a three-roll mill to prepare a nonmagnetic paste.

8 g of butyral resin, 4 g of butylbenzyl phthalate, 24 g of methyl ethyl ketone and 24 g of butyl acetate were mixed with 100 g of NiZnCu-based ferrite powder and kneaded using a pot mill to prepare a ferrite slurry.

Similarly, the composite type glass powder 10
8 g of butyral resin, 4 g of butylbenzyl phthalate, 24 g of methyl ethyl ketone and 24 g of butyl acetate were mixed with 0 g, and kneaded using a pot mill to prepare a nonmagnetic slurry.

Using a nonmagnetic slurry, a nonmagnetic green sheet having a thickness of 0.2 mm was prepared after drying using a coater. The green sheet was formed on a PET film.

Similarly, a ferrite green sheet having a thickness of 0.4 mm was prepared after drying using a ferrite slurry and a coater. The green sheet was formed on a PET film.

Three non-magnetic green sheets were stacked and laminated. A hot press is used for laminating the non-magnetic green sheets, and the platen temperature of the hot press is set to 100 ° C.
The pressure was 500 kg / cm ² . As shown in FIG. 4, a conical hollow portion 15 was formed in the non-magnetic material 4 using a mold and a puncher.

Next, as shown in FIG. 5, a commercially available conductor paste is used for the inner surface of the non-magnetic
Was formed. Further, the conductor 3 formed on the entire inner surface of the non-magnetic material 4 is cut into a predetermined three-dimensional spiral shape using a mold, and FIG.
As shown in (1), the conductor 3 was formed in a plurality of turns, and the diameter of each turn portion was gradually changed from one end to the other end, and at least each turn portion was formed in a different plane. The method of forming the conductor 3 on the entire inner surface of the non-magnetic material 4 is a method in which the conductor 3 is sucked from the surface opposite to the printing surface of the non-magnetic material 4 as in the generally known through-hole printing.

Next, as shown in FIG. 7, lead electrodes 6 and 8 were formed on the ferrite green sheet (thickness: 0.4 mm) prepared above using the same silver paste and printing machine as above, and the end face magnetic properties were measured. Layer 10 was produced. Further, the end face magnetic layer 1
The non-magnetic material 4 on which the conductor 3 was formed was bonded to the non-magnetic material 4.

Further, as shown in FIG.
The above-mentioned ferrite slurry was poured into the inner surface, that is, the hollow portion 15, to make it almost flat. That is, the inner magnetic body 2 was formed by this filling.

Next, as shown in FIG. 9, lead electrodes 5 and 7 were formed on the ferrite green sheet (thickness: 0.4 mm) prepared above using the same silver paste and printing machine as described above, and the end face magnetic properties were measured. Layer 9 was produced. Further, the end face magnetic layer 9 and the non-magnetic body 4 on which the inner magnetic body 2, the conductor 3, and the like were formed were laminated.

Further, an end face electrode 1 as shown in FIG.
1, 12, 13, and 14 were formed using a commercially available silver paste, and were fired at 900 ° C. for 2 hours.

The common mode choke coil of the present invention obtained by the above method did not show any defects such as peeling, cracking and warping. When various electric characteristics were measured using an impedance analyzer or the like, it was found that the common mode choke coil had excellent characteristics.

As described above, since no winding is performed by the method of the present invention, a common mode choke coil having excellent electric characteristics and excellent electric characteristics can be obtained as compared with the conventional method.

Example 2 Using the ferrite green sheet produced in Example 1, a hollow outer magnetic body 1 was produced in the same manner as in Example 1. As shown in FIG.
The inner surface of the hollow body was coated with the non-magnetic material 4 by a printing method using the non-magnetic paste prepared in Example 1. On the non-magnetic material 4, a conductor 3 having a plurality of turns in the same manner as in the first embodiment, wherein the diameter of each turn portion is gradually different from one end to the other end and at least each turn portion is located in a different plane. Was formed. Further, the conductor 3 was coated with the non-magnetic material 4 in the same manner as described above. The nonmagnetic material 4 was filled with the inner magnetic material 2.

Next, a common mode choke coil having the structure shown in FIG.
It baked on the conditions kept at 2 ° C for 2 hours.

The common mode choke coil of the present invention obtained by the above method did not show any defects such as peeling, cracking and warping. When various electric characteristics were measured using an impedance analyzer or the like, it was found that the common mode choke coil had excellent characteristics.

[0065]

As is clear from the above description, the common mode choke coil of the present invention has a structure in which a closed magnetic circuit-like magnetic material is shared by a plurality of conductors, so that it exhibits excellent electric characteristics and has a winding property. Since it does not depend on the wire construction method, it is excellent in productivity and high reliability can be secured. A common mode choke coil having excellent characteristics can be obtained by a non-winding method, which is of great industrial value.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a common mode choke coil of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a sectional view showing still another embodiment.

FIG. 4 is a schematic cross-sectional view showing a method for manufacturing a common mode choke coil according to the present invention.

FIG. 5 is a schematic cross-sectional view showing a method for manufacturing a common mode choke coil according to the present invention.

FIG. 6 is a schematic cross-sectional view showing a method for manufacturing a common mode choke coil according to the present invention.

FIG. 7 is a schematic cross-sectional view showing a method for manufacturing a common mode choke coil according to the present invention.

FIG. 8 is a schematic cross-sectional view showing a method for manufacturing a common mode choke coil according to the present invention.

FIG. 9 is a schematic cross-sectional view illustrating a method for manufacturing a common mode choke coil according to the present invention.

FIG. 10 is a schematic cross-sectional view showing a method for manufacturing a common mode choke coil according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer magnetic body 2 Inner magnetic body 3 Conductor 4 Non-magnetic body 5,6,7,8 Extraction electrode 9,10 End face magnetic layer 11,12,13,14 End face electrode 15 Hollow part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01F 41/04 H01F 15/14

Claims (6)

[Claims] 1. A closed loop comprising a plurality of turns in a non-magnetic material or on a surface, wherein each turn portion has a gradually changing diameter from one end to the other end and at least each turn portion is located in a different plane. A common mode choke coil having a single magnetic body in a shape, and wherein each of the conductors shares the magnetic body as a magnetic core. 2. The common mode choke coil according to claim 1, wherein a plurality of conductors are provided at positions vertically stacked on different planes, and the positions of the conductors partially overlap. 3. The common mode choke coil according to claim 1, wherein a plurality of conductors are provided at positions vertically stacked on different planes, and the positions of the conductors do not overlap. 4. The common mode choke coil according to claim 1, wherein the plurality of conductors are provided at positions arranged in different in-plane directions, and the positions of the respective conductors substantially coincide with each other. 5. A step of forming a hollow body-shaped magnetic body having a conical or pyramid-shaped hollow portion, and / or a step of forming a conical or pyramid-shaped magnetic body. Forming a non-magnetic material on the inner surface of the hollow magnetic material or on the side surface of the conical or pyramid-shaped magnetic material; and forming the inner surface of the hollow magnetic material on the side surface of the conical or pyramid-shaped magnetic material. Forming a plurality of conductors on the magnetic body such that the plurality of turns are formed such that the diameter of each turn portion is gradually different from one end to the other end and at least each turn portion is located in a different plane; Alternatively, a step of forming an end face layer on the upper and lower end faces of a conical or pyramid-shaped magnetic material may be performed.
A method for manufacturing a common mode choke coil in which one magnetic body is formed and each conductor is formed so as to share the magnetic body as a magnetic core. 6. A step of forming a hollow non-magnetic material having a conical or pyramid-shaped hollow portion, a step of forming a conical or pyramidal magnetic material, and a step of forming a hollow non-magnetic material. A plurality of conductors are formed such that a plurality of turns are formed on the inner surface of the or a conical or pyramid-shaped magnetic body, and the diameter of each turn portion gradually changes from one end to the other end and at least each turn portion is located in a different plane. And a step of forming end layers on the upper and lower end surfaces of a hollow non-magnetic material and a cone-shaped or pyramid-shaped magnetic material. One closed-loop magnetic material is formed, and each conductor forms the magnetic material. A method of manufacturing a common mode choke coil formed to be shared as a magnetic core.