JP2002359116A - Chip type common mode choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip type common mode choke coil that can make uniform the impedance value between a pair of coil sections, prevents noise from being given to normal mode characteristics, and has excellent magnetic coupling. SOLUTION: On the main surface of a magnetic substrate 1, a pair of coil wires is formed in structure where an insulating layer and a conductive thin film are overlapped in the thickness direction. A recess 1a is present on the magnetic substrate 1 under a section where the winding direction, the number of turns, or shape of the conductive thin films that become the pair of coil wires is different. An amorphous magnetic material 6 is buried into the recess 1a. At the same time, a magnetic material 10 is provided on a region including an equal shape section other than sections where the winding direction, the number of turns, or the shape of the conductive thin films is different.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component used as a countermeasure for noise invading various electronic devices, and more particularly to a chip type common mode choke coil.

[0002]

2. Description of the Related Art Conventionally, a laminated type is known as a chip type common mode choke coil. This component has a structure in which a coil conductor pattern is formed on the surface of a magnetic material sheet such as ferrite to form a first coil, and a first magnetic sheet for a second coil and a similar magnetic sheet for a second coil are alternately laminated.

Further, a coil component disclosed in Japanese Patent Application Laid-Open No. 8-203737 is known as one using a thin film method. As shown in FIGS. 7 and 8, this coil component is provided on an insulating layer 41 and extraction electrodes 53 and 5 on a magnetic substrate 40.
4, an insulating layer 42, a first coil conductor 51, an insulating layer 43, a second coil conductor 52, and an insulating layer 44 are arranged in this order, and are sandwiched by a magnetic substrate 45 from the upper surface thereof. The external electrodes 55 are formed on the side surfaces of the magnetic substrates 40 and 45 as shown in FIG. The through-hole 56 is for connecting the first coil conductor 51 and the extraction electrode 53 to form a first coil winding, and the through-holes 57a, 57b
Connects the second coil conductor 52 and the extraction electrode 54 to the second
In order to form the coil winding.

[0004]

In the above-mentioned conventional laminated type, a magnetic sheet exists between the first coil and the second coil conductor, and when used as a common mode choke coil, the magnetic properties of the two coil portions are reduced. The mechanical coupling is reduced, which causes a problem in characteristics.

In a thin-film common mode choke coil using the thin-film method shown in FIGS. 7 and 8, a non-magnetic insulating layer is provided between two coil conductors 51 and 52. Because it is sandwiched by 45,
The problem of magnetic coupling has been solved. However,
In this structure, in order to take out the external electrodes, the first coil conductor 51 and the second coil conductor 52 each have an area near the external electrodes 5.
1a, 52a and near the external electrodes 53 of the extraction electrodes 53, 54
At a and 54a, a difference occurs in the winding direction, the number of windings, and the shape (line length, etc.), thereby causing a difference in the impedance value of the two coil portions forming a pair. For this reason, the normal mode characteristics have a large adverse effect such as generation of noise. As a countermeasure, when the winding direction, the number of turns, and the shape of the coil conductor are the same, a large difference occurs between the two coil portions in the shape of the extraction electrode, and the same problem occurs.

Further, the electrical joint 56 between the external electrode 55 and the coil conductor or the end of the extraction electrode shown in FIG. 8 is only a cut surface of the conductor, and a problem is likely to occur in terms of electrical connection.

SUMMARY OF THE INVENTION In view of the above, the present invention increases the distance to the lower magnetic substrate and places the upper magnetic material in places where the winding direction, the number of turns, or the shape of the coil winding is different. By selectively arranging the upper magnetic material on the upper surface of the equivalently shaped portion of the winding, the impedance value between the coil portions forming a pair can be made uniform, and the magnetic characteristics that do not give noise to the normal mode characteristics can be achieved. An object of the present invention is to provide a chip type common mode choke coil having excellent coupling.

[0008] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0009]

In order to achieve the above object, a chip-type common mode choke coil according to the present invention has a structure in which an insulating layer and a conductive thin film are stacked in a thickness direction on a main surface of a magnetic substrate. A pair of coil windings is formed, and the winding direction, the number of turns or the shape of the conductor thin film to be the pair of coil windings has a recess in the magnetic substrate under a different place, and a nonmagnetic material is present in the recess. It is characterized in that a magnetic material is provided on a region that is buried and includes an equivalently shaped portion other than a portion where the conductor thin films have different winding directions, numbers of turns, or shapes.

In the chip type common mode choke coil, a plurality of pairs of coil windings may be provided.

An opening is formed in the insulating layer at a position corresponding to a central portion of the equivalently shaped portion of the coil winding and a peripheral portion of the equivalently shaped portion, and the magnetic material and the magnetic substrate are brought into contact with each other through the opening to close the magnetic field. It is good to have a road structure.

[0012] A part of the external electrode provided on a side surface of the magnetic substrate extends on a conductor film forming surface on which an end of the coil winding is formed or on a plane parallel to the film forming surface. Preferably, an end of the coil winding is connected to the external electrode on the conductor deposition surface or on a plane parallel to the deposition surface.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a chip type common mode choke coil according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of a chip type common mode choke coil according to the present invention. At the time of actual production, a plurality of chip-type common mode choke coils are produced simultaneously on a magnetic substrate, but in the present embodiment, description will be made for one element.

As shown in FIGS. 1 and 2, the chip-type common mode choke coil comprises an insulating layer 2, conductive thin-film extraction electrodes 13 and 14, an insulating layer 3, and a conductive thin-film on a main surface of a magnetic substrate 1. A first coil conductor 11, an insulating layer 4, a second coil conductor 12 of a conductive thin film, and an insulating layer 5 are sequentially provided. A first coil winding is formed by connecting the first coil conductor 11 and the extraction electrode 13 in series, and a second coil winding is formed by connecting the second coil conductor 12 and the extraction electrode 14 in series. Locations 11a, 12a, 13a, 14a where the winding directions, number of turns, or shapes (line length, etc.) of the second coil windings are different.
(Near the lead-out electrode and the external electrode take-out part of the coil conductor)
A concave portion 1a is formed in the lower magnetic substrate 1, and a nonmagnetic material 6 is embedded in the concave portion 1a. Non-magnetic material 6
Is a flat surface having the same height as the main surface of the magnetic substrate 1. Further, the portions 11a, 12a, 11a, 12a,
The region including the upper surface of the portion having the same shape as the conductive thin film other than 13a and 14a is covered with the magnetic material 10. Further, as shown in FIG. 2, external electrodes (terminal electrodes) 15 are formed on the side surface of the magnetic substrate 1. The equivalently shaped portion is a portion that can be regarded as having substantially the same shape even though there is a slight difference.

On the insulating layer 2, the two extraction electrodes 13, 14 connected to the external electrode 15 are formed by a thin film forming method, and one end of each of the two extraction electrodes 13, 14 is electrically connected to the external electrode 15. Are connected to each other. With respect to the other end, the extraction electrode 13 is provided through the through hole 16 of the insulating layer 3, and the extraction electrode 14 is provided through the through holes 17 a and 17 b of the insulating layers 3 and 4.
1 and 12 are electrically connected respectively. The other ends of the coil conductors 11 and 12 are connected to external electrodes 15, respectively.

As described above, the magnetic material 10 in the uppermost layer is formed of the coil conductors 11 and 12 and the extraction electrodes 13 and 14 at locations 11a and 1 having greatly different winding directions, turns or shapes.
Upper layers other than 2a, 13a and 14a are selectively covered.

The magnetic substrate 1 is made of sintered ferrite, composite ferrite, or the like. The insulating layers 2, 3, 4, and 5 are made of a material having excellent insulation properties such as polyimide resin and epoxy resin and having good workability. Reference numeral 10 denotes a sintered ferrite thin plate, a composite ferrite, etc., and the coil conductors 11 and 12, the extraction electrode 1
Metals having excellent electric conductivity, such as Cu, Ag, and Al, are used for the materials 3 and 14. The non-magnetic material 6 burying the concave portions 1a formed on both edges of the magnetic substrate 1 is the same resin or the like as the insulating layer 2 or the like.

Next, a manufacturing procedure of the chip type common mode choke coil according to the present embodiment will be described with reference to FIG.

A nonmagnetic material is buried by a printing method or the like in the concave portion 1a of the magnetic substrate 1 in which the concave portion 1a has been formed in advance.

Next, an insulating layer 2 is formed on the magnetic substrate 1. As a forming method, a spin coating method, a dipping method,
A spray method, a printing method, or the like is employed.

Then, a conductive thin film is formed on the insulating layer 2 and the extraction electrodes 13 and 14 are formed by photolithography.
Is formed. As a film forming method, a thin film forming method such as sputtering, vapor deposition, or plating is employed. In the photolithography method, a photosensitive resist is used, and after exposure and development, unnecessary metal portions are etched, and then the resist is peeled off.

Next, an insulating layer 3 is formed. The forming method is the same as that of the insulating layer 2, but the through holes 16 and 17 a are formed by development using a photolithography method in order to connect the extraction electrodes 13 and 14 and the coil conductors 11 and 12. The extraction electrode 13 and the first coil conductor 11 are electrically connected by the through hole 16.

Next, the first coil conductor 11 is formed and patterned. The construction method is the same as that of the extraction electrodes 13 and 14.

After that, the insulating layer 4 is formed by the same method as the insulating layer 3. Here, the through hole 17b is formed by development using a photolithography method. The extraction electrode 14 and the second coil conductor 12 are electrically connected by the through hole 17b and the through hole 17a formed in the insulating layer 3.

Next, film formation and patterning of the second coil conductor 12 are performed. The construction method is the same as that of the extraction electrodes 13 and 14.

Thereafter, an insulating layer 5 is formed on the entire surface by the same method.

Further, the first and second coil conductors 11, 1
2 and locations where the winding direction, number of turns, or shape of the coil conductor and the extraction electrode near the external electrode connection on the outer periphery of the magnetic substrate 1 (that is, the outer periphery of the chip after completion) of the extraction electrodes 13 and 14 are different.
The magnetic material 10 is selectively formed thick in a layered manner (or a thin plate of the magnetic material 10 is arranged and fixed) in a region including an equivalently shaped portion other than 1a, 12a, 13a, and 14a.

Although the above description is for one element,
In practice, a plurality of elements are simultaneously produced on a substrate. After the device fabricated on this substrate is cut into one element shape, external electrodes 15 are formed on the side surface of the magnetic substrate 1 for one element, and a chip type common mode choke coil is completed.

According to the first embodiment, of a pair of coil windings (series connection of a coil conductor and an extraction electrode), a region in which the winding direction, the number of turns, the shape, and the line length are substantially the same. The magnetic material exists above and below, and high impedance is obtained. However, the portion where the winding direction, the number of turns or the shape near the external electrode 15 where the impedance difference is likely to occur is different from the conductor thin film due to the presence of the recess 1a. Substrate 1
Is large and the magnetic material 10 does not exist above, the impedance is low, and the difference between the impedances of the two coil portions of the common mode choke coil is small.
As a result, it is possible to produce a component that is small in size, has excellent magnetic properties, and has negligible adverse effects such as noise on a normal mode signal.

FIGS. 3 and 4 show a second embodiment of the present invention in which a part of the upper magnetic material 10 is joined to the lower magnetic substrate 1 to form a closed magnetic circuit structure. Show. In this case, the manufacturing procedure is the same as that of the first embodiment, except for the pattern shape of the insulating layers 2, 3, 4, and 5. An insulating layer opening 2 is formed in each insulating layer forming region in the first embodiment.
a, 3a, 4a, and 5a are formed by development so as to overlap each other, and when the upper magnetic material 10 is formed in a layer shape,
The magnetic material 10 enters the insulating layer openings 2a, 3a, 4a, 5a and is joined to the lower magnetic substrate 1 to form a closed magnetic circuit structure. Here, of the paired coil windings (series connection of the coil conductor and the extraction electrode), one central portion and two right and left outside the region having approximately the same winding direction, number of turns, shape, and line length. Since the openings 2a, 3a, 4a, and 5a are located at (peripheries of the region), a closed magnetic path is formed so as to surround a portion having substantially the same winding direction, number of turns, shape, and line length of the coil winding. Be composed.

The same or corresponding parts as in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

According to the second embodiment, the first
In addition to the functions and effects of the embodiment, a part of the upper magnetic material 10 is joined to the lower magnetic substrate 1 to form a closed magnetic circuit structure, so that higher magnetic coupling and normal mode signal can be obtained. Noise countermeasures can be taken.

FIGS. 5 and 6 show a third embodiment of the present invention, in which the connection between the end of the coil winding and the external electrode 15 is further ensured. In this case, the manufacturing procedure is the same as that of the first embodiment, but different points are the pattern shape of the thin film conductor of the coil winding and the pattern shape of the insulating layer. That is, the wide conductor portions 21 and 22 are attached to the ends of the coil conductors 11 and 12 constituting the pair of coil windings connected to the external electrodes at the time of development by photolithography.
2 are formed, and wide conductors 23 and 24 are also formed at ends of the extraction electrodes 13 and 14 connected to the external electrodes. Insulating layer openings 3b, 4b, 5b for taking out external electrodes are formed in the insulating layers 3, 4, 5 at positions overlapping each other. Then, as shown in FIG. 6, by providing the external electrodes 15 extending to the side surfaces of the magnetic substrate 1 and the upper and lower surfaces adjacent thereto, the external electrodes 15 are formed as wide ends which are the ends of the first and second coil windings. The conductor portions 21, 22, 23, and 24 are joined on the conductor film formation surface (shown in a joining portion 26 in FIG. 6).

The ends of the first and second coil conductors 11 and 12 constituting the first and second coil windings connected to the external electrodes and the ends of the lead electrodes 13 and 14 connected to the external electrodes are connected to each other. A configuration in which each is led out onto the upper insulating layer 5 through a through hole and is connected to a part of the external electrode 15 extended on the insulating layer 5 (a configuration in which the external electrode 15 is connected to a plane parallel to the conductor film formation surface). It may be.

As in the second embodiment, the insulating layer openings 2a, 3a, 4a, and 5a are also formed in the respective insulating layer forming regions so as to overlap each other, and the magnetic substrate 1 and the upper magnetic material 1 are formed.
0 constitutes a closed magnetic circuit, and the same or corresponding parts as in the second embodiment are denoted by the same reference numerals and description thereof is omitted.

According to the third embodiment, the magnetic material 10 is selectively formed on the first and second coil windings. There is a portion where there is no gap, and by using this portion, it is possible to increase the bonding area between the external electrode 15 and the conductor thin film at the end of the coil winding, so that the electrical connection can be stabilized.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be. For example, the pattern shape, lead shape, and magnetic material shape of the coil winding may be different from those of the embodiment. Further, in each embodiment, the concave portion formed on the magnetic substrate is continuous in the longitudinal direction of the magnetic substrate.
A partial recess may be used as long as at least the vicinity of the position where the coil winding passes can be replaced with a non-magnetic material. Further, in each embodiment, one pair of coils is used for one element, but the present invention is applicable to a component in which a plurality of pairs of coils are included in one element.

[0039]

As described above, according to the present invention,
A concave portion is provided at an appropriate position on the magnetic substrate located below the conductor thin film that will be the coil winding that forms the pair, and the magnetic material is selectively arranged on the upper side to make the impedance of the coil portion forming the pair uniform. Thus, a compact chip-type common mode choke coil with excellent magnetic coupling that does not give noise to the normal mode characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a chip-type common mode choke coil according to the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 4 is a front sectional view of the same.

FIG. 5 is an exploded perspective view showing a third embodiment of the present invention.

FIG. 6 is a perspective view of the same.

FIG. 7 is an exploded perspective view of a conventional technique.

FIG. 8 is a perspective view of the same.

[Explanation of symbols]

 1,40,45 Magnetic substrate 1a Depression 2,3,4,5,41,42,43,44 Insulating layer 2a, 3a, 3b, 4a, 4b, 5a, 5b Opening 6 Non-magnetic material 10 Magnetic material 11, 12, 51, 52 Coil conductors 13, 14, 53, 54 Leader electrodes 15, 55 External electrodes 16, 17a, 17b Through holes 21, 22, 23, 24 Wide conductor portion

Claims (4)

[Claims] 1. A pair of coil windings having a structure in which an insulating layer and a conductor thin film are stacked in a thickness direction on a main surface of a magnetic substrate, and the windings of the conductor thin films to be the coil windings forming the pair are formed. A concave portion is present in the magnetic substrate under a location where the direction, the number of turns or the shape is different, and a non-magnetic material is buried in the concave portion and an equivalent shape other than a location where the winding direction, the number of turns or the shape of the conductor thin films is different. A chip-type common mode choke coil characterized in that a magnetic material is provided on a region including a portion. 2. The chip-type common mode choke coil according to claim 1, wherein a plurality of pairs of the coil windings are provided. 3. An opening is formed in the insulating layer at a position corresponding to a central portion of the equivalently shaped portion of the coil winding and a peripheral portion of the equivalently shaped portion, and the magnetic material and the magnetic substrate come into contact with each other through the opening. And a closed magnetic circuit structure.
The described chip type common mode choke coil. 4. A part of an external electrode provided on a side surface of the magnetic substrate extends on a conductor film forming surface on which an end of the coil winding is formed or on a plane parallel to the film forming surface. 4. The chip-type common mode choke coil according to claim 1, wherein an end of said coil winding is connected to said external electrode on said conductor film-forming surface or a plane parallel to said film-forming surface.