JP6303123B2 - Common mode noise filter - Google Patents

Description

  The present invention relates to a small and thin common mode noise filter used in various electronic devices such as digital devices, AV devices, and information communication terminals.

  As shown in FIG. 10, the conventional common mode noise filter of this type has a first coil 2 and a second coil 3 formed on a plurality of laminated insulator layers 1a to 1g. One coil 2 is configured by connecting spiral first and second coil conductors 4a and 4b, and the second coil 3 is configured by connecting spiral third and fourth coil conductors 5a and 5b. Further, the first and second coil conductors 4a and 4b constituting the first coil 2 and the third and fourth coil conductors 5a and 5b constituting the second coil 3 are alternately arranged. It had been. Further, the insulator layer 1a provided on the lowermost surface and the insulator layer 1g provided on the uppermost surface are made of a magnetic material, and the other insulator layers 1b to 1f are made of a nonmagnetic material. The coil 2 and the second coil 3 were surrounded by a nonmagnetic material. Then, the first coil conductor 4a and the third coil conductor 5a are magnetically coupled to form the first common mode filter unit 6, and the second coil conductor 4b and the fourth coil conductor 5b are magnetically coupled. The second common mode filter unit 7 is combined to form the first common mode filter unit 6 and the second common mode filter unit 7 in series, thereby ensuring a high common mode impedance and reducing common mode noise. I was trying to remove it.

  As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.

JP 2002-373810 A

  In the above-described conventional common mode noise filter, since the first coil conductor 4a and the fourth coil conductor 5b are close to the insulator layers 1a and 1g made of a magnetic material, the insulator layer made of a magnetic material is used. The inductance value is larger than that of the third coil conductor 5a and the second coil conductor 4b that are separated from 1a and 1g.

  As a result, the first coil conductor 4a and the third coil conductor 5a are magnetically coupled with different inductance values to form the first common mode filter unit 6, and the second coil conductor 4b and the fourth coil conductor 5b. Are magnetically coupled with different inductance values to form the second common mode filter unit 7, so that when a differential signal is input, the first coil of the first common mode filter unit 6 Amplitude and phase between each signal passing through the conductor 4a and the third coil conductor 5a, and between each signal passing through the second coil conductor 4b and the fourth coil conductor 5b of the second common mode filter unit 7. The differential balance of the input signal deviates from the ideal state (zero amplitude difference and 180 ° phase difference). Proportion of the converted output (hereinafter Scd21 characteristics) had a problem that increases.

  Furthermore, since the plurality of coil conductors are stacked in the stacking direction, the differential signal balance may be shifted depending on the size of the stray capacitance between the coil conductors and the location where the stray capacitance is generated, and the Scd21 characteristics deteriorate. .

  The present invention solves the above-described conventional problems, and an object thereof is to provide a common mode noise filter capable of improving the Scd21 characteristic.

  In order to achieve the above object, the present invention has the following configuration.

According to a first aspect of the present invention, there is provided an insulator portion having a plurality of nonmagnetic layers, a magnetic portion made of a magnetic material laminated on the top and bottom of the insulator portion, and the insulator portion. The first coil is composed of a spiral first coil conductor and a second coil conductor, and the second coil is a spiral third coil. A coil conductor and a fourth coil conductor, and a third coil conductor and a fourth coil conductor constituting the second coil, and a first coil conductor and a second coil conductor constituting the first coil. The first and second coil conductors constituting the first coil and the third and fourth coil conductors constituting the second coil are alternately arranged so as to be sandwiched between coil conductors , and , Part of the first coil conductor and the third coil conductor in a top view Substantially placed in the same position, the winding direction in the same direction, the first to form a common mode filter portion said first coil conductor and the third coil conductor by the magnetic coupling, the viewed from the top second The coil conductor and a part of the fourth coil conductor are arranged at substantially the same position, the winding direction is the same direction, and the second coil conductor and the fourth coil conductor are magnetically coupled to each other. A mode filter portion is formed, the first common mode filter portion and the second common mode filter portion are connected in series, and the line widths of the first to fourth coil conductors are sequentially set to b1, b2 , B3, and b4 satisfy b1> b2 and b3 <b4. According to this configuration, since the cross-sectional area of the two coil conductors located in the portion closest to the magnetic body portion increases, its self-inductance To reduce this Therefore, the inductance value of the two coil conductors located in the central part away from the magnetic part and the inductance values of the two coil conductors located in the part closest to the magnetic part are substantially equal. Thus, the Scd21 characteristic can be prevented from deteriorating in the first common mode filter unit and the second common mode filter unit when a differential signal is input.

According to a second aspect of the present invention, there is provided an insulator portion having a plurality of nonmagnetic layers, a magnetic portion made of a magnetic material laminated on top and bottom of the insulator portion, and the insulator portion. The first coil is composed of a spiral first coil conductor and a second coil conductor, and the second coil is a spiral third coil. A coil conductor and a fourth coil conductor, and a third coil conductor and a fourth coil conductor constituting the second coil, and a first coil conductor and a second coil conductor constituting the first coil. Further, the first coil conductor and the third coil conductor are magnetically coupled to form a first common mode filter portion, and the second coil conductor and the fourth coil are arranged to be sandwiched between the coil conductors. Magnetically coupling the conductors to form the second common mode filter And, wherein the first common mode filter portion and the second common mode filter section connected in series, and constitute the entire non-magnetic layer between said third coil conductor and the fourth coil conductor The dielectric constant of the material to be made is smaller than the dielectric constant of the material constituting the other nonmagnetic material layer. According to this configuration, the third coil conductor and the fourth coil conductor constituting the second coil Since the stray capacitance generated between the input and output can be reduced, the jumping leakage of the signal between the input and output can be reduced via the stray capacitance in the second coil, and thus the differential signal is input. Sometimes, the differential balance between signals passing through the first coil conductor and the third coil conductor in the first common mode filter section, and the second coil conductor and the second coil conductor in the second common mode filter section, respectively. The signal passing through each of the four coil conductors Since the differential balance between the first common mode filter unit and the second common mode filter unit need not be increased, the Scd21 characteristic can be improved. When common mode noise is input, the first common mode filter section and the second common mode filter section are strongly magnetically coupled to function as an inductor, and a large common mode impedance can be obtained. This has the effect of obtaining noise removal performance.

  As described above, the common mode noise filter according to the present invention reduces the inductance values of the two coil conductors located at the upper and lower positions closer to the magnetic body portion, thereby reducing the two coil conductors located at the central portion away from the magnetic body portion. The inductance value and the inductance values of the two coil conductors located near the magnetic body portion are made substantially equal, whereby the first common mode filter portion and the second common mode filter portion have Scd21 characteristics when a differential signal is input. There is an excellent effect that it is possible to prevent the deterioration.

1 is an exploded perspective view of a common mode noise filter according to Embodiment 1 of the present invention. Perspective view of the common mode noise filter Circuit diagram of the common mode noise filter An exploded perspective view of another example of the common mode noise filter The disassembled perspective view of the common mode noise filter in Embodiment 2 of this invention Circuit diagram of the common mode noise filter The disassembled perspective view of the common mode noise filter in Embodiment 3 of this invention Schematic diagram for explaining the common mode noise filter The figure which shows the Sdc21 characteristic of the common mode noise filter in the conventional common mode noise filter and Embodiment 1, 2, and 3 of this invention Exploded perspective view of a conventional common mode noise filter

(Embodiment 1)
FIG. 1 is an exploded perspective view of a common mode noise filter according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of the common mode noise filter.

  As shown in FIG. 1, the common mode noise filter according to the first exemplary embodiment of the present invention is laminated with insulator parts 12 having first to fifth nonmagnetic layers 11 a to 11 e and above and below the insulator parts 12. Magnetic body portions 13a and 13b made of the magnetic material formed, and first and second coils 14 and 15 formed in the insulator portion 12, and the first coil 14 is a spiral first coil conductor. 16 and the second coil conductor 17, the second coil 15 is composed of the spiral third coil conductor 18 and the fourth coil conductor 19, and the first coil 14 is configured as the first coil 14. The second coil conductors 16 and 17 and the third and fourth coil conductors 18 and 19 constituting the second coil 15 are alternately arranged.

  Further, the first coil conductor 16 and the third coil conductor 18 are magnetically coupled to form the first common mode filter unit 20, and the second coil conductor 17 and the fourth coil conductor 19 are magnetically coupled. A second common mode filter unit 21 is formed, and the first common mode filter unit 20 and the second common mode filter unit 21 are connected in series.

  In the above configuration, the first to fifth nonmagnetic layers 11a to 11e are laminated in order from the bottom, and are made of a non-ferromagnetic material, for example, a non-magnetic material such as Cu-Zn ferrite or glass ceramic, into a sheet shape. It is configured. And the insulator part 12 which has the 1st-5th nonmagnetic material layers 11a-11e is comprised.

  Further, first and second coils 14 and 15 are formed inside the insulator portion 12, and the first coil 14 is connected to the spiral first coil conductor 16 and the spiral second coil conductor. 17, and the second coil 15 is constituted by a spiral third coil conductor 18 and a spiral fourth coil conductor 19.

  The first to fourth coil conductors 16 to 19 are each formed by spirally plating or printing a conductive material such as silver.

  At this time, the first coil conductor 16 is the upper surface of the first nonmagnetic material layer 11a, the second coil conductor 17 is the upper surface of the third nonmagnetic material layer 11c, and the third coil conductor 18 is the second nonmagnetic material. The upper surface of the magnetic layer 11b and the fourth coil conductor 19 are respectively formed on the upper surface of the fourth nonmagnetic layer 11d.

  That is, the first and second coil conductors 16 and 17 constituting the first coil 14 and the third and fourth coil conductors 18 and 19 constituting the second coil 15 are alternately laminated. Has been. Here, the first coil conductor 16 and a part of the third coil conductor 18 are arranged at substantially the same position in a top view, and are magnetically coupled by setting the winding direction to the same direction, so that the first common mode filter Similarly, a part 20 of the second coil conductor 17 and the fourth coil conductor 19 are arranged at substantially the same position in the top view, and the winding direction is also made the same direction so as to be magnetically coupled. A second common mode filter unit 21 is formed.

  Further, two first and fourth coil conductors 16 and 19 positioned above and below among the first to fourth coil conductors 16 to 19 are two first and fourth coil conductors 16 positioned above and below. , 19 is positioned closer to the magnetic body portions 13a and 13b in the stacking direction than the two second and third coil conductors 17 and 18 sandwiched between the two, and closer to the magnetic body portions 13a and 13b in the stacking direction. The lengths of the two first and fourth coil conductors 16 and 19 located on the side are located at the center portion in the stacking direction and are located on the side far from the magnetic body portions 13a and 13b. The coil conductors 17 and 18 are shorter than the lengths of the coil conductors 17 and 18, respectively. That is, the number of turns of the first and fourth coil conductors 16 and 19 is smaller than the number of turns of the second and third coil conductors 17 and 18, respectively.

  The first coil conductor 16 and the second coil conductor 17 are connected to each other via the first via electrodes 21a formed in the second and third nonmagnetic layers 11b and 11c, respectively. One coil 14 is formed. Further, the third coil conductor 18 and the fourth coil conductor 19 are connected to each other via the second via electrodes 21b formed in the third and fourth nonmagnetic layers 11c and 11d, respectively. Two coils 15 are formed.

  The first via electrodes 21a are provided at the same position when viewed from above, and the second via electrodes 21b are also provided at the same position when viewed from above. In addition, the first via electrode 21a and the second via electrode 21b are formed by drilling holes at predetermined positions of each nonmagnetic material layer and magnetic material layer and filling the holes with silver. .

  Magnetic body portions 13a and 13b made of a magnetic material are provided on the lower surface of the first nonmagnetic material layer 11a and the upper surface of the fifth nonmagnetic material layer 11e, respectively. Ni-Cu-Zn ferrite etc. comprised in the shape.

  The number of sheets constituting the first to fifth non-magnetic layers 11a to 11e and the magnetic portions 13a and 13b is not limited to the number shown in FIG.

  And the main-body part 22 of a common mode noise filter is formed as shown in FIG. Further, first and fourth external electrodes 23a to 23d are provided on both end faces of the main body 22, and the first to fourth external electrodes 23a to 23d are respectively first to fourth coil conductors. 16 to 19 are connected. Further, the first to fourth external electrodes 23a to 23d are formed by printing silver on the end face of the main body portion 22, and a nickel plating layer is formed on these surfaces by plating. A low melting point metal plating layer such as tin or solder is formed on the surface by plating.

  FIG. 3 is a circuit schematic diagram of the common mode noise filter according to the first embodiment of the present invention.

  As described above, in the common mode noise filter according to the first exemplary embodiment of the present invention, the first, fourth, and fourth coil conductors 16-19, which are located closer to the magnetic body portions 13a, 13b in the stacking direction, The lengths of the fourth coil conductors 16 and 19 are set such that the second and third coil conductors 17 located between the first and fourth coil conductors 16 and 19 and located far from the magnetic parts 13a and 13b, Since the inductance values of the first and fourth coil conductors 16 and 19 located closer to the magnetic body portions 13a and 13b can be reduced by making the length shorter than the length of 18, respectively, the magnetic body portions 13a and 13b The inductance values of the second and third coil conductors 17 and 18 located in the separated central part and the first and fourth parts located in the parts closer to the magnetic body parts 13a and 13b. The inductance values of the wire conductors 16 and 19 can be made substantially equal, and this prevents the Scd21 characteristics of the first common mode filter unit 20 and the second common mode filter unit 20 from deteriorating when a differential signal is input. The effect of being able to be obtained is obtained.

  In addition, the second and second coil conductors 16 and 19 that are located closer to the magnetic body parts 13a and 13b have second and second cross-sectional areas that are located farther from the magnetic body parts 13a and 13b. Since the self-inductance of the first and fourth coil conductors 16 and 19 decreases if the cross-sectional area of the third coil conductors 17 and 18 is made larger, the inductance values of the first and fourth coil conductors 16 and 19 are lowered. Can do. As a result, the inductance values of the second and third coil conductors 17 and 18 and the inductance values of the first and fourth coil conductors 16 and 19 can be made substantially equal to each other. It is possible to prevent the Scd21 characteristics of the common mode filter unit 20 and the second common mode filter unit 20 from deteriorating.

  At this time, the first and fourth coil conductors 16 and 19 located closer to the magnetic parts 13a and 13b have the second and second coil conductors 16 and 19 located in the central part farther away from the magnetic parts 13a and 13b. In order to make it larger than the cross-sectional area of the third coil conductors 17 and 18, as shown in FIG. 4, the line widths of the first and fourth coil conductors 16 and 19 are set to be the second and third coil conductors 17 and 17, respectively. Each line width may be wider than 18 lines. At this time, the lengths of the first and fourth coil conductors 16 and 19 may be shorter than the lengths of the second and third coil conductors 17 and 18, or may be substantially the same length. .

  Then, the second and third coils are located in the center portion where the cross-sectional areas of the first and fourth coil conductors 16 and 19 located closer to the magnetic parts 13a and 13b are separated from the magnetic parts 13a and 13b. In order to make it larger than the cross-sectional area of the conductors 17 and 18, the thickness of the first and fourth coil conductors 16 and 19 may be larger than the thickness of the second and third coil conductors 17 and 18, respectively. Furthermore, since it is not necessary to increase the facing area between the first coil conductor 16 and the third coil conductor 18 and between the second coil conductor 17 and the fourth coil conductor 19, these It is possible to prevent the stray capacitance between the coil conductors from increasing, thereby preventing the characteristic impedance of the differential mode from being lowered and preventing the deterioration of the differential signal.

(Embodiment 2)
FIG. 5 is an exploded perspective view of the common mode noise filter according to Embodiment 2 of the present invention. In the second embodiment of the present invention, components having the same configurations as those of the first embodiment of the present invention are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment of the present invention and the first embodiment of the present invention is that the second coil conductor 17 and the fourth coil conductor 19 are interchanged as shown in FIG. The third coil conductor 18 and the fourth coil conductor 19 constituting the coil 15 are arranged so as to be sandwiched between the first coil conductor 16 and the second coil conductor 17 constituting the first coil 14. .

  Then, the thicknesses of the first and second coil conductors 16 and 17 that are positioned above and below the first to fourth coil conductors 16 to 19 and closer to the magnetic body portions 13a and 13b are set to The thicknesses of the first and second coil conductors 16 and 17 are larger than the thicknesses of the two third and fourth coil conductors 18 and 19 that are located farther from the magnetic body portions 13a and 13b.

  As in the first embodiment, the lengths of the two first and second coil conductors 16 and 17 positioned closer to the magnetic body portions 13a and 13b in the stacking direction are set to the magnetic body portions 13a and 13b. Shorter than the lengths of the two third and fourth coil conductors 18 and 19 located in a portion farther from 13b and located in the central portion in the stacking direction, or the width of the first and second coil conductors 16 and 17 May be made narrower than the widths of the two third and fourth coil conductors 18 and 19 located in the central portion in the stacking direction.

  A schematic circuit diagram in this case is shown in FIG.

  According to said structure, 1st, 2nd coil located in the part nearer to magnetic body parts 13a, 13b among 1st-4th coil conductors 16-19 like Embodiment 1 of the present invention. Since the inductance values of the conductors 16 and 17 can be lowered, the inductance values of the third and fourth coil conductors 18 and 19 located in the center portion away from the magnetic body portions 13a and 13b and the magnetic body portions 13a and 13b The inductance values of the first and second coil conductors 16 and 17 located in the close portion can be made substantially equal, whereby the first common mode filter unit 20 and the second common mode filter can be used when a differential signal is input. It is possible to prevent the Scd21 characteristic from being deteriorated in the portion 21.

(Embodiment 3)
FIG. 7 is an exploded perspective view of the common mode noise filter according to Embodiment 3 of the present invention. In the third embodiment of the present invention, components having the same configurations as those of the first and second embodiments of the present invention are denoted by the same reference numerals, and the description thereof is omitted.

  The third embodiment of the present invention is different from the second embodiment of the present invention described above in that, as shown in FIG. 7, the third coil conductor 18 and the fourth coil conductor located in the central portion in the stacking direction. The third nonmagnetic material layer 11c between the first and second nonmagnetic material layers 19 is made thicker than other nonmagnetic material layers.

  Here, since the third coil conductor 18 and the fourth coil conductor 19 have the same potential at the low frequency, the common mode noise filter shown in FIG. Then, as shown in FIG. 8, a potential difference is generated between the third coil conductor 18 and the fourth coil conductor 19, and between the input / output electrodes (or between the outer peripheral portions of the coils connected to the external electrodes). Stray capacitance C is generated.

  Since the configuration shown in FIG. 7 can reduce the stray capacitance generated between the third coil conductor 18 and the fourth coil conductor 19 constituting the second coil 15, The inter-signal leakage between the input and output can be reduced through the stray capacitance, whereby the first coil conductor 16 in the first common mode filter unit 20 when a differential signal is input. Differential balance between signals passing through the first coil conductor 18 and the third coil conductor 18, and differential balance between signals passing through the second coil conductor 17 and the fourth coil conductor 19 in the second common mode filter unit 21, respectively. Can be prevented, and thus the Scd21 characteristics can be improved.

  Therefore, as shown in FIG. 7, the thickness of the third nonmagnetic material layer 11c between the third coil conductor 18 and the fourth coil conductor 19 located at the central portion in the stacking direction is set to be different from that of other nonmagnetic materials. If the stray capacitance between the third coil conductor 18 and the fourth coil conductor 19 is reduced by making it thicker than the thickness of the body layer, the Scd21 characteristic can be improved even in the high frequency region.

  Here, FIG. 9 shows a conventional common mode noise filter, the common mode noise filter according to the first embodiment of the present invention, the common mode noise filter according to the second embodiment of the present invention, and the embodiment of the present invention shown in FIG. 3 shows the Scd21 characteristic of the common mode noise filter in FIG. In order to show the degree of the effect of reducing the stray capacitance between the third coil conductor 18 and the fourth coil conductor 19 in the third embodiment of the present invention in the high-frequency region, in FIG. 4 shows characteristics when the thickness, width and length of the four coil conductors 16 to 19 are approximately the same. In the common mode noise filter according to the first and second embodiments of the present invention, the thicknesses of the two coil conductors located in the portions closer to the magnetic body portions 13a and 13b in the stacking direction are set to 2 in the central portion in the stacking direction. It is shown that it is thicker than the thickness of one coil conductor.

  As is clear from FIG. 9, in the low frequency region of 1 GHz or less, the common mode noise filter according to the first and second embodiments of the present invention has smaller Scd21 characteristics than the conventional common mode noise filter, and the differential mode Good characteristics can be obtained with little conversion to the common mode. Further, in a high frequency region exceeding 1 GHz, compared to the conventional common mode noise filter, the common mode noise filter according to the first embodiment of the present invention, and the common mode noise filter according to the second embodiment of the present invention having the configuration of FIG. It can be seen that the common mode noise filter according to the third embodiment of the present invention having the configuration of FIG. 7 significantly improves the Scd21 characteristics. That is, it can be seen that the configuration of reducing the stray capacitance between the third coil conductor 18 and the fourth coil conductor 19 in FIG. 7 greatly contributes to the Scd21 improvement effect in the high frequency region.

  Further, in order to reduce the stray capacitance between the third coil conductor 18 and the fourth coil conductor 19, a third non-magnetic material between the third coil conductor 18 and the fourth coil conductor 19 is used. The dielectric constant of the material constituting the layer 11c may be smaller than the dielectric constant of the material constituting the other nonmagnetic material layer. In this case, since it is not necessary to increase the distance between the first common mode filter unit 20 and the second common mode filter unit 21 (thickening the third nonmagnetic layer 11c), common mode noise is input. In this case, the first common mode filter unit 20 and the second common mode filter unit 21 are strongly magnetically coupled to function as an inductor, and a large common mode impedance can be obtained. Performance is also obtained.

  In the third embodiment of the present invention, the effect of reducing the stray capacitance generated between the third coil conductor 18 and the fourth coil conductor 19 constituting the second coil 15 is large in the high frequency region. Therefore, the lengths of the first and second coil conductors 16 and 17 are made shorter than the lengths of the third and fourth coil conductors 18 and 19, or the line widths of the first and second coil conductors 16 and 17 are reduced. Is wider than the line width of the third and fourth coil conductors 18 and 19, and the thickness of the first and second coil conductors 16 and 17 is larger than the thickness of the third and fourth coil conductors 18 and 19. Even when the thickness is not increased, the Scd21 characteristics can be sufficiently improved particularly at high frequencies.

  In addition, you may adjust the thickness, width | variety, and length of the coil conductors 16 and 17 close | similar to the magnetic body parts 13a and 13b like Embodiment 1,2.

  Further, in the above-described common mode noise filters according to the first to third embodiments of the present invention, the first coil 14 and the second coil 15 are provided, but two or more arrays are provided. It is good also as a type.

  Furthermore, although what provided the 1st common mode filter part 20 and the 2nd common mode filter part 21 each was demonstrated, you may provide two or more.

  And in order to improve magnetic coupling, you may form a magnetic body part in the center part of the 1st-5th nonmagnetic body layers 11a-11e.

  The common mode noise filter according to the present invention has an effect that the Scd21 characteristic can be improved, and is a small size particularly used as a noise countermeasure for various electronic devices such as digital devices, AV devices, and information communication terminals. This is useful in a thin common mode noise filter or the like.

11a to 11e First to fifth nonmagnetic layers 12 Insulator portions 13a and 13b Magnetic portion 14 First coil 15 Second coil 16 First coil conductor 17 Second coil conductor 18 Third coil Conductor 19 Fourth coil conductor 20 First common mode filter portion 21 Second common mode filter portion

Claims (2)

An insulator part having a plurality of nonmagnetic layers, a magnetic part made of a magnetic material laminated on and under the insulator part, and first and second coils formed on the insulator part are provided. The first coil is composed of a spiral first coil conductor and a second coil conductor, and the second coil is composed of a spiral third coil conductor and a fourth coil conductor, The third coil conductor and the fourth coil conductor constituting the second coil are arranged so as to be sandwiched between the first coil conductor and the second coil conductor constituting the first coil, or the first coil conductor The first and second coil conductors constituting the second coil and the third and fourth coil conductors constituting the second coil are alternately arranged , and the first coil conductor and A part of the third coil conductor is arranged at substantially the same position, and the winding direction is And in one direction, the first coil conductor and the third coil conductor to form a first common mode filter portion by magnetic coupling, the second coil viewed from top
A second common mode filter is formed by arranging a conductor and a part of the fourth coil conductor at substantially the same position, setting the winding direction to the same direction, and magnetically coupling the second coil conductor and the fourth coil conductor. The first common mode filter unit and the second common mode filter unit are connected in series, and the line widths of the first to fourth coil conductors are b1, b2, b3 in order from the top. , B4, a common mode noise filter satisfying b1> b2 and b3 <b4. An insulator part having a plurality of nonmagnetic layers, a magnetic part made of a magnetic material laminated on and under the insulator part, and first and second coils formed on the insulator part are provided. The first coil is composed of a spiral first coil conductor and a second coil conductor, and the second coil is composed of a spiral third coil conductor and a fourth coil conductor, The third coil conductor and the fourth coil conductor constituting the second coil are arranged so as to be sandwiched between the first coil conductor and the second coil conductor constituting the first coil, and A first common mode filter unit is formed by magnetically coupling the first coil conductor and the third coil conductor, and a second common mode filter is formed by magnetically coupling the second coil conductor and the fourth coil conductor. Forming the first common mode field. Data unit and connecting the second common mode filter unit in series, and the dielectric constant of the material constituting the entire non-magnetic layer between the third coil conductor and the fourth coil conductor, other Common mode noise filter made smaller than the dielectric constant of the material constituting the nonmagnetic layer.

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