JP2725499B2 - Chip type common mode choke coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type common mode choke coil used for removing common mode noise that enters electronic equipment and the like.

[0002]

2. Description of the Related Art As one type of chip-type common mode choke coil, a structure in which a magnetic material layer and a coil conductor are stacked, and the coil conductors are electrically connected via through holes has been considered. I have. In this common mode choke coil, a coil conductor and an external electrode are electrically connected through a lead conductor. The magnetic material layer is made of a material having a relatively high magnetic permeability so that the coil has high impedance over a wide frequency band with respect to common mode noise. As a result, the coil can secure a high inductance, and can exhibit excellent common mode noise removal performance.

However, when a material having a high magnetic permeability is used for the magnetic material layer, the impedance of the lead conductor also becomes a non-negligible value, and the lead conductor acts as an inductor with respect to the normal mode signal. There was a problem of changing. Accordingly, an object of the present invention is to provide a chip-type common mode choke coil having a structure having a high impedance with respect to common mode noise and a low impedance with respect to a normal mode signal.

[0004]

In order to solve the above-mentioned problems, a chip-type common mode choke coil according to the present invention comprises a coil portion in which a coil conductor and a high-permeability material layer are alternately stacked, and a lead-out conductor. And the high permeability material of the coil part
A low- permeability material layer having a low magnetic permeability is alternately stacked, and a lead portion is provided, and the coil conductors and the lead conductors are electrically connected.

[0005] As a high magnetic permeability material of the coil portion, a magnetic permeability of 7
A ferrite-based material of 00 (representative value) is used, and a ferrite-based material of 20 (representative value) is used as the low magnetic permeability material of the lead portion. Further, the high magnetic permeability material or the low magnetic permeability material is not necessarily limited to one kind of material, and a material having several kinds of different magnetic permeability may be used in a multilayer structure.

[0006]

In the above arrangement, since a low-permeability material is used for the lead portion, the impedance of the lead conductor becomes extremely small and is ignored for a normal mode signal.
On the other hand, in the coil portion, when selecting a material having a high magnetic permeability, it is not necessary to consider the impedance of the lead-out conductor, and a material exhibiting the most excellent removing effect on common mode noise is selected.

[0007]

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 accompanying drawings.
In each of the embodiments, the same components and the same portions are denoted by the same reference numerals. First Embodiment, FIGS. 1 to 3 As shown in FIG. 1, the chip-type common mode choke coil of the first embodiment includes a coil portion 18 and lead portions 47 and 48. The coil portion 18 includes four high-permeability magnetic sheets 1, 2, 3, 4
And coil conductors 5, 7, 6, 8 provided on the upper surface of each of the magnetic sheets 1-4. As the material of the high magnetic permeability magnetic sheets 1 to 4, a ferrite material having a high magnetic permeability (for example, 700) is used. The coil conductors 5 and 6 are provided with through holes 10 and 1 provided in the magnetic sheets 1 and 2, respectively.
1 to form one coil 17a of the common mode choke coil. The coil conductors 7 and 8 are provided in the through holes 1 provided in the magnetic sheets 2 and 3.
2 and 13 are electrically connected to form another coil 17b of the common mode choke coil.

The lead portion 47 is composed of three low magnetic permeability magnetic sheets 21, 22, 23 and lead conductors 30, 31 provided on the upper surfaces of the magnetic sheets 22 and 23, respectively. Further, the drawer portion 48 includes four low-permeability magnetic sheets 24,
25, 26, 27 and lead conductors 32, 33 provided on the upper surfaces of the magnetic sheets 25 and 26, respectively. As the material of the low magnetic permeability magnetic sheets 21 to 27, a ferrite material having a low magnetic permeability (for example, 20) is used. The magnetic sheets 1 to 27 of the coil portion 18 are added to the magnetic sheets 21 to 27.
If a ferrite-based material of the same quality as that of No. 4 is used, warpage or peeling during firing hardly occurs, which is advantageous in production. It is not always necessary to use the low magnetic permeability magnetic sheets 21 to 27,
For example, a nonmagnetic sheet may be used instead of the magnetic sheets 21 to 27. As a non-magnetic material, for example,
A dielectric ceramic, an insulating resin material, a vitreous material, or the like, which is an insulator, is used.

In the stacked state, the lead conductor 30 is electrically connected to the coil 17a via through holes 37 and 38 provided in the magnetic sheets 22 and 23. Similarly, in the laminated state, the lead-out conductor 31 is provided with the through holes 39 and 9 provided in the magnetic sheets 23 and 1.
The lead conductor 32 is electrically connected to the coil 17a via the through holes 40 and 15 provided in the magnetic sheets 24 and 4, and the lead conductor 33 is connected to the coil 17b. It is electrically connected to the coil 17b via through holes 42 and 41 provided in the sheets 25 and 24.

After stacking the above insulating sheets 1-4 and 21-27, they are fired to form a laminated structure as shown in FIG. On the end face on the near side of the laminated structure, a lead-out conductor 3 is provided.
2 and 33 are exposed, and lead-out conductors 30 and 31 are exposed on an end face on the back side, not shown. further,
As shown in FIG. 3, the external electrodes A1, A2, B1, B2 are provided at the ends of the laminated structure so as to be electrically connected to the lead-out conductors 30, 32, 31, 33, respectively.

In the chip type common mode choke coil thus obtained, since the extraction portions 47 and 48 are made of a material having low magnetic permeability, the impedance generated in the extraction conductors 30 to 33 is extremely small, and the normal mode signal Has little effect on Therefore, a chip type common mode choke coil that can remove common mode noise without changing the waveform of the normal mode signal is obtained.

[Second Embodiment, FIG. 4] In a second embodiment, a chip-type common mode choke coil having a structure in which a lead conductor is not sandwiched between low magnetic permeability magnetic sheets will be described. The coil portion 65 is provided above and below the coil portion 18 described in the first embodiment with the high magnetic permeability magnetic sheets 50 and 51.
Is arranged. On the upper surface of the magnetic material sheet 50, a lead conductor 5 constituting a part of a lead portion 75 described later
2, 53 are provided, and on the lower surface of the magnetic sheet 51, lead-out conductors 54, 55 described later are provided.

The lead portion 75 includes one magnetic sheet 21 having a low magnetic permeability and lead conductors 52 and 53. In addition, the lead portion 76 includes one low magnetic permeability magnetic sheet 27 and the lead conductors 54 and 55. In the stacked state, the lead conductor 52 is electrically connected to the coil 17b through the through holes 59 and 9 provided in the magnetic sheets 50 and 1, and the lead conductor 53 is provided in the through hole provided in the magnetic sheet 50. The lead conductor 54 is electrically connected to the coil 17a through the through holes 61 and 15 provided in the magnetic sheets 51 and 4, and is electrically connected to the coil 17a through the hole 60. Magnetic sheet 51, 4
Through the through holes 62 and 16 provided in the coil 17.
b.

The above insulating sheets 1-4, 21, 27, 5
After stacking 0 and 51, firing is performed to produce a laminated structure, and external electrodes are provided to produce a product. The chip-type common mode choke coil thus obtained has the same operation and effect as the common mode choke coil of the first embodiment, and can reduce the number of low magnetic permeability magnetic sheets.

[Third Embodiment, FIGS. 5 to 7] The third embodiment has a structure in which the lead-out conductor is not sandwiched between the low-permeability magnetic sheets, which is different from the second embodiment. This is another chip type common mode choke coil. In FIG. 5, the coil section 18 is the same as that described in the first embodiment, and a description thereof will be omitted.

The lead portion 95 comprises a single magnetic sheet 80 of low magnetic permeability and lead conductors 82 and 83 provided on the upper surface of the magnetic sheet 80. The lead portion 96 includes a single magnetic sheet 81 of low magnetic permeability and lead conductors 84 and 85 provided on the lower surface of the magnetic sheet. In a stacked state,
The lead conductor 82 is electrically connected to the coil 17b through through holes 89 and 9 provided in the magnetic sheets 80 and 1, and the lead conductor 83 is connected to the coil 17 through a through hole 90 provided in the magnetic sheet 80. The lead conductor 84 is electrically connected to the coil 17a through the through holes 91 and 15 provided in the magnetic sheets 81 and 4.
Is electrically connected to the magnetic sheet 8.
It is electrically connected to the coil 17b via through holes 92 and 16 provided in 1 and 4.

After stacking the above insulating sheets 1-4, 80 and 81, they are fired to form a laminated structure as shown in FIG. Further, when mounted on a printed wiring board or the like, an insulating paint is applied to the upper and lower surfaces of the laminated structure as shown in FIG. An insulating protective film 98 is formed. Thereafter, the external electrodes A1, A2, B1, and B2 are provided at the ends of the laminated structure so as to be electrically connected to the lead-out conductors 82, 84, 83, and 85, respectively, to obtain a product. The chip-type common mode choke coil thus obtained has the same operation and effect as the common mode choke coil of the second embodiment.

[Fourth Embodiment, FIGS. 8 to 11] As shown in FIG. 8, the common mode choke coil of the fourth embodiment is
The coil section 18 is the same as that described in the first embodiment. After the coil portion 18 is fired, FIG.
As shown in FIG.
With one end of the magnetic film 100 exposed, the low-permeability magnetic film 100
Is formed by means such as printing. Similarly, though not shown, through holes 16 and 1 are formed on the lower surface of coil portion 18.
A low-permeability magnetic material film is formed by printing or the like with the 5 exposed. Next, as shown in FIG. 10, the lead conductors 105 and 106 are formed on the surface of the magnetic film 100 in a state of being electrically connected to the through hole 9 and the coil conductor 5, respectively. Similarly, a lead conductor is formed on the lower surface of the coil portion 18.

Further, as shown in FIG. 11, when mounted on a printed wiring board or the like, in order to avoid a short circuit with a conductor pattern or a land of the printed wiring board or the like, an insulating paint is applied to the lead-out conductors 105 and 106. Insulating protective film 11 applied from above
0 is formed. Similarly, an insulating protective film is formed on the lower surface side of the coil portion 18. Thereafter, the external electrodes A1, A2,
B1 and B2 are provided so as to be electrically connected to the lead-out conductors 105 and 106, respectively, to obtain a product. The chip-type common mode choke coil thus obtained has the same operation and effect as the common mode choke coil of the first embodiment.

[Other Embodiments] The chip-type common mode choke coil according to the present invention is not limited to the above-described embodiment, but may be variously modified within the scope of the invention. In the above embodiment, the through hole is used for electrical connection between the coil conductor and the lead conductor. However, the present invention is not necessarily limited to this method. It may be. Further, the coil conductor may be spiral.

[0021]

As is apparent from the above description, according to the present invention, since the low-permeability material is used for the extraction portion, the impedance of the extraction conductor is extremely small, and the extraction conductor for the normal mode signal is used. Hardly acts as an inductor. On the other hand, the coil portion does not need to consider the impedance of the lead-out conductor when selecting a material having a high magnetic permeability, and can select a material exhibiting the most excellent removing effect on common mode noise. Therefore, a chip-type common mode choke coil having high impedance in a wide band with respect to common mode noise and low impedance with respect to a normal mode signal can be obtained. As a result, the ability to remove common mode noise can be improved without changing the waveform of the normal mode signal.

[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 showing a laminated structure of the chip-type common mode choke coil shown in FIG.

FIG. 3 is a perspective view showing the appearance of the chip-type common mode choke coil shown in FIG.

FIG. 4 is an exploded perspective view showing a second embodiment of the chip-type common mode choke coil according to the present invention.

FIG. 5 is an exploded perspective view showing a third embodiment of the chip-type common mode choke coil according to the present invention.

6 is a perspective view showing a laminated structure of the chip-type common mode choke coil shown in FIG.

FIG. 7 is a perspective view showing the appearance of the chip-type common mode choke coil shown in FIG.

FIG. 8 is a perspective view showing a coil portion of a fourth embodiment of the chip-type common mode choke coil according to the present invention.

9 is a perspective view for explaining a procedure for forming a lead portion in a coil portion of the chip-type common mode choke coil shown in FIG.

FIG. 10 is an exemplary perspective view for continuously describing a procedure for forming a lead portion in the coil portion of the chip-type common mode choke coil shown in FIG. 9;

FIG. 11 is a perspective view showing the appearance of a chip-type common mode choke coil according to a fourth embodiment of the present invention.

[Explanation of symbols]

1,2,3,4 ... High magnetic permeability magnetic sheet 5,6,7,8 ... Coil conductor 9-16 ... Through hole 18 ... Coil part 21,22,23,24,25,26,27 ... Low Magnetic permeability sheets 30, 31, 32, 33 ... Lead-out conductors 37 to 42 ... Through holes 47, 48 ... Lead-out parts 50, 51 ... High permeability magnetic substance sheets 52, 53, 54, 55 ... Lead-out conductors 59 62 through-hole 65 coil part 75, 76 lead-out part 80, 81 low-magnetic-permeability magnetic sheet 82, 83, 84, 85 lead-out conductor 89-92 through-hole 95, 96 lead-out part 100 Low magnetic permeability magnetic film 100 105, 106...

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01F 27/28 H01F 27/28 DM

Claims (1)

(57) [Claims] 1. A coil part in which a coil conductor and a high magnetic permeability material layer are alternately stacked, a lead conductor and a high permeability of said coil part.
A chip structure, comprising: a laminated structure composed of lead portions in which low- permeability material layers having a lower magnetic permeability than the magnetic permeability material are alternately stacked, and the coil conductors and the lead conductors are electrically connected. Common mode choke coil.