JP6186591B2 - 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.

  A 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 as shown in FIG. 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 coil conductors 5a and 5b constituting the second coil 3 were disposed between the first coil conductor 4a and the second coil conductor 4b constituting the first coil 2. . 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. The first coil conductor 4a and the third coil conductor 5a are magnetically coupled, and the second coil conductor 4b and the fourth coil conductor 5b are magnetically coupled to remove common mode noise. It was.

  For example, Patent Document 1 is known as an arrangement in which two coil conductors constituting the second coil are sandwiched between two coil conductors constituting the first coil.

  For example, Patent Document 2 is known in which two coils are formed in a nonmagnetic material and a magnetic material is provided on the uppermost surface and the lowermost surface.

JP 2000-173837 A JP 2001-60514 A

  In the above-described conventional common mode noise filter, the third and fourth coil conductors 5a and 5b constituting the second coil 3 are separated from the insulator layers 1a and 1g made of a magnetic material. Therefore, the magnetic field can hardly be utilized, and as a result, the magnetic flux generated in the third and fourth coil conductors 5a and 5b is reduced, so that the first coil conductor 4a and the third coil conductor 5a are magnetically coupled. The magnetic coupling between the second coil conductor 4b and the fourth coil conductor 5b is lowered, thereby causing a problem that the impedance of the common mode component is reduced and the attenuation characteristic of the common mode noise is deteriorated. .

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a common mode noise filter that can improve the attenuation characteristics of common mode noise.

In order to achieve the above object, the present invention is formed on an insulator part having a plurality of non-magnetic layers, a magnetic part made of a magnetic material laminated above and below the insulator part, and the insulator part. And 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 third coil conductor that constitutes the second coil and a fourth coil conductor that are composed of a conductor and a fourth coil conductor, and a first coil conductor and a second coil that constitute the first coil Arranged so as to be sandwiched between conductors, or alternately arranged first and second coil conductors constituting the first coil and third and fourth coil conductors constituting the second coil, and Among the first to fourth coil conductors, in the central portion in the stacking direction Forming a magnetic layer of a magnetic material between two coil conductors that location, and the thickness of the nonmagnetic layer formed on the upper and lower layers of the magnetic layer thinner than the thickness of the other of said non-magnetic layer but, according to this configuration, it is possible to provide a magnetic layer of a magnetic material in the vicinity of the two coil conductors located in the middle portion in the stacked direction, the two coil conductors are apart from the magnetic body portion Even if it is formed at a different position, the magnetic field of the magnetic layer between the two coil conductors can be utilized, and thereby the magnetic flux generated by the two coil conductors is not reduced. The magnetic coupling between the second coil conductor and the fourth coil conductor does not deteriorate, thereby increasing the impedance of the common mode component and improving the attenuation characteristics of the common mode noise. And it has a effect that it is possible to.

  As described above, the common mode noise filter of the present invention includes the third coil conductor and the fourth coil conductor constituting the second coil, and the first coil conductor and the second coil constituting the first coil. Since it arrange | positions so that it may be pinched | interposed by a conductor, and the magnetic body layer which consists of magnetic materials is formed between the 3rd coil conductor and the 4th coil conductor, the 3rd coil conductor and the 4th coil conductor A magnetic layer made of a magnetic material can be provided near the third coil conductor, so that even if the third coil conductor and the fourth coil conductor are formed away from the magnetic body portion, the third coil conductor And the fourth coil conductor can utilize the magnetic field of the magnetic layer, so that the magnetic flux generated in the third and fourth coil conductors is not reduced. As a result, the first coil conductor and the third coil Magnetic coupling with conductor, second coil conductor and fourth coil Since the magnetic coupling between the conductors is not reduced, the impedance of the common mode component is increased, in which an excellent effect that it is possible to improve the attenuation characteristic of the common mode noise.

The disassembled perspective view of the common mode noise filter in one embodiment of this invention Perspective view of the common mode noise filter Exploded perspective view of a conventional common mode noise filter

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

  As shown in FIGS. 1 and 2, the common mode noise filter according to the first exemplary embodiment of the present invention includes an insulator portion 12 having first to sixth nonmagnetic layers 11 a to 11 f, and an insulator portion 12. Magnetic body parts 13a and 13b made of magnetic materials stacked one above the other and first and second coils 14 and 15 formed on the insulator part 12 are provided, and the first coil 14 is formed into a spiral first. The coil coil 16 and the second coil conductor 17 are configured, and the second coil 15 is configured by the spiral third coil conductor 18 and the fourth coil conductor 19, thereby configuring the second coil 15. The third coil conductor 18 and the fourth coil conductor 19 are arranged so as to be sandwiched between the first coil conductor 16 and the second coil conductor 17 constituting the first coil 14. A magnetic layer 20 made of a magnetic material is formed between the third coil conductor 18 and the fourth coil conductor 19.

  In the above configuration, the first to sixth nonmagnetic layers 11a to 11f are laminated in order from the bottom, and are configured in a sheet shape from a nonmagnetic material such as Cu—Zn ferrite or glass ceramic. And the insulator part 12 which has the 1st-6th nonmagnetic material layers 11a-11f 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 fifth nonmagnetic material layer 11e, 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 coil conductor 16 and the second coil conductor 17 constituting the first coil 14 are laminated so as to sandwich the third and fourth coil conductors 18 and 19 constituting the second coil 15. ing. Here, a part of the first coil conductor 16 and the third coil conductor 18 are arranged at substantially the same position in a top view, and the winding direction is also the same direction. Similarly, a part of the 2nd coil conductor 17 and the 4th coil conductor 19 are arrange | positioned in the substantially same position by the top view, and the winding direction is also made the same direction.

  The first coil conductor 16 and the second coil conductor 17 are connected to the second to fifth nonmagnetic layers 11b to 11e and the first via electrode 21a formed in the magnetic layer 20, respectively. Are connected to each other to form a first coil 14. Further, the third coil conductor 18 and the fourth coil conductor 19 are formed by second via electrodes formed on the third nonmagnetic material layer 11c, the fourth nonmagnetic material 11d, and the magnetic material layer 20, respectively. The second coil 15 is configured by being connected to each other via 21b. Thus, both the first via electrode 21a and the second via electrode 21b are formed in the third and fourth nonmagnetic layers 11c and 11d and the magnetic layer 20.

  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 sixth nonmagnetic material layer 11f, respectively. Ni-Cu-Zn ferrite etc. comprised in the shape.

  Further, the magnetic layer 20 is in the form of a sheet, is made of a magnetic material such as Ni—Cu—Zn ferrite, and is provided between the third nonmagnetic layer 11c and the fourth nonmagnetic layer 11d. It has been. Thus, the third nonmagnetic layer 11c is provided between the magnetic layer 20 and the third coil conductor 18, and the fourth nonmagnetic layer is provided between the magnetic layer 20 and the fourth coil conductor 19. Thus, the magnetic layer 20 and the third and fourth nonmagnetic layers 11c and 11d are located between the third coil conductor 18 and the fourth coil conductor 19. The insulator portion 12 includes first to sixth nonmagnetic layers 11 a to 11 f and a magnetic layer 20.

  The number of sheets constituting the first to sixth nonmagnetic layers 11a to 11f, the magnetic layer 20, and the magnetic portions 13a and 13b is not limited to the number shown in FIG. In addition, since the third coil conductor 18 and the fourth coil conductor 19 are not magnetically coupled, even if the magnetic layer 20 is formed between the third coil conductor 18 and the fourth coil conductor 19, There is no problem.

  And the main-body part 22 of a common mode noise filter is formed by the above-mentioned structure. 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.

  As described above, in the common mode noise filter according to the embodiment of the present invention, the third coil conductor 18 and the fourth coil conductor 19 constituting the second coil 15 constitute the first coil 14. A magnetic material layer 20 made of a magnetic material is formed between the third coil conductor 18 and the fourth coil conductor 19 so as to be sandwiched between the first coil conductor 16 and the second coil conductor 17. Therefore, the magnetic layer 20 made of a magnetic material can be provided in the vicinity of the third coil conductor 18 and the fourth coil conductor 19, whereby the third coil conductor 18 and the fourth coil conductor 19. Is formed at a position away from the magnetic body portions 13a and 13b, and even if the magnetic field of the magnetic body portions 13a and 13b cannot be utilized, it is between the third coil conductor 18 and the fourth coil conductor 19. Magnetic layer 20 Since the magnetic field can be utilized, the magnetic flux generated in the third and fourth coil conductors 18 and 19 is not reduced. As a result, the magnetic coupling between the first coil conductor 16 and the third coil conductor 18, the second Since the magnetic coupling between the coil conductor 17 and the fourth coil conductor 19 does not decrease, the impedance of the common mode component is increased, and the effect of improving the attenuation characteristics of the common mode noise can be obtained.

  In addition, it is preferable that each of the third and fourth nonmagnetic layers 11c and 11d is thinner. By doing so, the thickness of the common mode noise filter can be reduced, and the third and fourth nonmagnetic layers 11c between the third coil conductor 18 and the fourth coil conductor 19 can be further reduced. , 11d, the total length of the first via electrode 21a and the second via electrode 21b can be shortened, so that the DC resistance values of the first and second coils 14 and 15 can be lowered. it can. Since the third coil conductor 18 and the fourth coil conductor 19 have the same potential, even if the distance between the third coil conductor 18 and the fourth coil conductor 19 is shortened to some extent, a short circuit may occur. Is low.

  At this time, the thicknesses of the third and fourth nonmagnetic layers 11c and 11d are smaller than those of the other nonmagnetic layers 11a, 11b, 11e, and 11f, for example, 1/3 to 1/2 of the thickness. Then, the distance between the third and fourth coil conductors 18 and 19 and the magnetic layer 20 is shortened, so that the magnetic flux generated in the third and fourth coil conductors 18 and 19 can be increased.

  Thus, if the thickness of each of the third and fourth nonmagnetic layers 11c and 11d is made thinner than the thicknesses of the other nonmagnetic layers 11a, 11b, 11e, and 11f, the DC resistance value as described above can be obtained. In addition to the effect of lowering, the length (depth) of the first via electrode 21a and the second via electrode 21b formed in each layer is short, so that the first and second via electrodes 21a and 21b It is also possible to prevent connection failure due to insufficient filling of silver.

  Furthermore, the thickness of the magnetic layer 20 is preferably larger than the thickness of the non-magnetic layers 11a to 11f because the impedance of the common mode component is increased. However, considering the reduction in thickness of the product, the magnetic portions 13a and 13b are preferable. It is more preferable to make it thinner than the thickness.

  In the above-described common mode noise filter according to the embodiment of the present invention, the third coil conductor 18 and the fourth coil conductor 19 constituting the second coil 15 constitute the first coil 14. Although arranged so as to be sandwiched between the first coil conductor 16 and the second coil conductor 17, the first and second coil conductors 16 and 17 constituting the first coil 14 and the second coil 15 are constituted. The third and fourth coil conductors 18 and 19 may be arranged alternately.

  Also in this case, the magnetic layer 20 made of a magnetic material is formed between two coil conductors located in the central portion in the stacking direction among the first to fourth coil conductors 16 to 19. Although these two coil conductors are far from the magnetic parts 13a and 13b, the magnetic layer 20 made of a magnetic material can be provided in the vicinity of the two coil conductors. The magnetic field of the magnetic layer 20 between the two coil conductors can be utilized, and thereby the effect of improving the attenuation characteristics of common mode noise can be obtained. The two coil conductors are coil conductors constituting different coils.

  The common mode noise filter according to the present invention has an effect of improving the attenuation characteristics of common mode noise, and is 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 small and thin common mode noise filter or the like.

11a to 11f First to sixth 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 Magnetic layer

Claims (4)

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 first coil and the third and fourth coil conductors constituting the second coil are alternately arranged, and the first to fourth coil conductors are laminated. Magnetic material between two coil conductors located in the central part in the direction Forming a Ranaru magnetic layer, common mode noise filter of thickness of the nonmagnetic layer formed on the upper and lower layers of the magnetic layer thinner than the thickness of the other of said non-magnetic layer. The first coil conductor and the second coil conductor are connected by a first via electrode, the third coil conductor and the fourth coil conductor are connected by a second via electrode, and the first via is connected. The common mode noise filter according to claim 1, wherein an electrode and the second via electrode are formed on the nonmagnetic layer. 2. The common mode noise filter according to claim 1, wherein the thickness of the nonmagnetic layer formed on the upper and lower layers of the magnetic layer is set to 1/3 to 1/2 of the thickness of the other nonmagnetic layer. The common mode noise filter according to claim 1, wherein a thickness of the magnetic body portion is larger than a thickness of the nonmagnetic body layer.

Images