JP2011176165A - Common mode noise filter - Google Patents

Abstract

An object of the present invention is to provide a common mode noise filter that improves impedance and allows easy adjustment of impedance.
A common mode noise filter of the present invention connects a first conductor 12 and a second conductor 13 by a first via electrode 16a formed in a second insulating layer 11b, and a third conductor. The conductor 14 and the fourth conductor 15 are connected by a second via electrode 16b formed in the fourth insulating layer 11d, and at least the third insulating layer 11c is made of a nonmagnetic material, and the third In the insulating layer 11c, two magnetic body portions 17 made of a magnetic material are provided inside the second conductor 13 and the third conductor 14, and the first magnetic material portion 17 is disposed between the two magnetic body portions 17 in a top view. The via electrode 16a and the second via electrode 16b are located.
[Selection] Figure 1

Description

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

  As shown in FIG. 5, this conventional common mode noise filter includes two coils 2 and 3 formed on the nonmagnetic layer 1 and a magnetic layer 4 formed above and below the two coils 2 and 3. The two coils 2 and 3 were respectively composed of spiral conductors 2a and 3a and lead conductors 2b and 3b connected to the conductors 2a and 3a. And in each nonmagnetic layer 1 in the inner part of the spiral of the coils 2 and 3, one magnetic body part 5 obtained by filling the through hole of the nonmagnetic layer 1 with a magnetic material was formed. .

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

JP 2001-76930 A

  The conventional common mode noise filter described above has a problem that it is not easy to improve impedance and adjust impedance.

  That is, if the size of the magnetic part 5 is increased in order to improve the impedance, the magnetic material may fall out of the through holes, or cracks may occur around the magnetic part 5 during firing due to the difference in thermal shrinkage rate. If a problem occurs and the size of the magnetic body portion 5 is increased, the magnetic body portion 5 occupies most of the inner portions of the spiral conductors 2a and 3a. Therefore, the number of turns of the conductors 2a and 3a is increased. It is difficult to increase the length by increasing the length of the signal, and the impedance cannot be adjusted. Furthermore, even if the number of turns of the spiral conductors 2a and 3a can be increased, the number of turns of the conductors 2a and 3a can be changed only for every turn, so that the impedance cannot be finely adjusted.

  SUMMARY OF THE INVENTION 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 impedance and easily adjust impedance.

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

  According to a first aspect of the present invention, the first conductor provided on the top surface of the first insulating layer, the second insulating layer provided on the top surface of the first conductor, and the second A spiral second conductor provided on the upper surface of the insulating layer and connected to the first conductor; a third insulating layer provided on the upper surface of the second conductor; and the third insulation. A spiral third conductor provided on the top surface of the layer, a fourth insulating layer provided on the top surface of the third conductor, and provided on the top surface of the fourth insulating layer and the third conductor A fourth conductor connected to a conductor, the first conductor and the second conductor are connected by a first via electrode formed in the second insulating layer, and the third conductor A conductor and the fourth conductor are connected by a second via electrode formed in the fourth insulating layer, and at least the third insulating layer is connected to the non-conductive layer. In the third insulating layer, two magnetic bodies made of a magnetic material are provided on the inner side of the second conductor and the third conductor, and the two magnetic bodies are formed in a top view. The first via electrode and the second via electrode are located between the two. According to this configuration, since it is not necessary to increase the size of one magnetic body portion, the magnetic material may fall off. No cracks are generated around the magnetic part during firing due to the difference in thermal shrinkage rate, and the area of the two magnetic parts can be increased, thereby improving the impedance. Can do. Furthermore, when changing the lengths of the second conductor and the third conductor, it is only necessary to go around only one of the two magnetic parts, so the number of turns is about every 0.5 turns. By changing the length, the length can be increased, and thereby, the effect that the impedance can be easily adjusted is obtained.

  As described above, the common mode noise filter of the present invention includes the second conductor in the third insulating layer made of a non-magnetic material, and two magnetic parts made of a magnetic material inside the third conductor. Since the first via electrode and the second via electrode are positioned between the two magnetic body portions when viewed from above, it is not necessary to increase the size of one magnetic body portion. Since the magnetic material does not fall off or cracks are not generated around the magnetic body part during firing due to the difference in thermal shrinkage rate, the area of the two magnetic body parts as a whole can be increased. Thus, the impedance can be improved. Further, when changing the lengths of the second conductor and the third conductor, it is only necessary to circulate around only one of the two magnetic parts, so that the number of turns is about every 0.5 turns. The length can be increased by changing it, and this provides an excellent effect that the impedance can be easily adjusted.

The disassembled perspective view of the common mode noise filter in one embodiment of this invention Transmission top view of the common mode noise filter Perspective view of the common mode noise filter Transmission top view when the lengths of the second conductor and the third conductor of the common mode noise filter are changed Exploded perspective view of a conventional common mode noise filter

  Hereinafter, a common mode noise filter according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view of a common mode noise filter according to an embodiment of the present invention, FIG. 2 is a transparent top view of the common mode noise filter, and FIG. 3 is a perspective view of the common mode noise filter.

  As shown in FIGS. 1 to 3, the common mode noise filter according to one embodiment of the present invention includes a first conductor 12 provided on the upper surface of the first insulating layer 11 a and the first conductor 12. A second insulating layer 11b provided on the upper surface, a spiral second conductor 13 provided on the upper surface of the second insulating layer 11b and connected to the first conductor 12, and the second A third insulating layer 11c provided on the upper surface of the conductor 13, a spiral third conductor 14 provided on the upper surface of the third insulating layer 11c, and an upper surface of the third conductor 14; The fourth insulating layer 11d and the fourth conductor 15 provided on the upper surface of the fourth insulating layer 11d and connected to the third conductor 14 are provided. Then, the first conductor 12 and the second conductor 13 are connected by the first via electrode 16a formed in the second insulating layer 11b, and the third conductor 14 and the fourth conductor are connected. The conductor 15 is connected by a second via electrode 16b formed in the fourth insulating layer 11d. Further, the second to fourth insulating layers 11b to 11d are made of a non-magnetic material, and the second conductor 13 and the third conductor 14 inside the second to fourth insulating layers 11b to 11d. Two magnetic body portions 17 made of a magnetic material are provided, and the first via electrode 16a and the second via electrode 16b are positioned between the two magnetic body portions 17 in a top view. Further, a dummy insulating layer 11e made of a magnetic material is formed on the upper surface of the fourth conductor 15.

  In addition, the laminated body 18 is formed by the above-described configuration, and a pair of external electrodes 19 are formed on both sides of the laminated body.

  The said structure WHEREIN: The said 1st-4th insulating layers 11a-11d are laminated | stacked in order from the bottom. The first insulating layer 11a is made of a magnetic material made of Ni—Cu—Zn ferrite, the second to fourth insulating layers 11b to 11d contain glass such as glass ceramic, and the first insulating layer 11a. It is made of a low magnetic permeability material having a lower magnetic permeability or a nonmagnetic material made of Cu-Zn ferrite. Furthermore, a first via electrode 16a and a second via electrode 16b are provided at predetermined positions of the second and fourth insulating layers 11b and 11d, respectively. The first via electrode 16a and the second via electrode 16b are formed by filling a through hole with Ag.

  The first to fourth conductors 12 to 15 are formed by plating a conductive material such as silver. The first and fourth conductors 12 and 15 are formed in a linear shape, and the second and third conductors 13 and 14 are formed in a spiral shape. Further, the first conductor 12 and the second conductor 13 are connected via the first via electrode 16a to constitute one independent first coil 20, and the third conductor 14 and the fourth conductor 15 is connected via the second via electrode 16b to form another independent second coil 21. Furthermore, both end portions (one end portions of the first to fourth conductors 12 to 15) of the two coils 20 and 21 are connected to a pair of external electrodes 19. The shapes of the second and third conductors 13 and 14 may be spiral instead of spiral. In FIGS. 1 and 2, the second and third conductors 13 and 14 are substantially rectangular, but may be substantially circular or elliptical.

  Further, the spiral second conductor 13 and the third conductor 14 substantially overlap each other in a top view through the third insulating layer 11 c except in the vicinity of the connection portion with the external electrode 19. Furthermore, the first via electrode 16a and the second via electrode 16b are also substantially overlapped when viewed from above. In FIG. 2 and FIG. 4 described later, the first conductor 12 and the second conductor 13 are shown so as to be above the third conductor 14 and the fourth conductor 15.

  The first via electrode 16a and the second via electrode 16b are positioned inside the spiral second and third conductors 13 and 14, that is, the innermost side of the second and third conductors 13 and 14, respectively. In a further inner region of the portion to be formed, it is formed at a substantially central portion in a top view. In this region, two magnetic body portions 17 are formed across a portion where the first via electrode 16a and the second via electrode 16b are located in a top view. At this time, the two magnetic body portions 17 are formed at positions that are point-symmetric with respect to a portion where the first via electrode 16a and the second via electrode 16b are located in a top view.

  Further, the two magnetic body portions 17 are formed by providing two through holes in each of the second to fourth insulating layers 11b to 11d and filling the through holes with a magnetic material. At this time, the magnetic body portion 17 is connected to the first insulating layer 11a and the dummy insulating layer 11e made of a magnetic material. With this configuration, the magnetic coupling between the coils 20 and 21 can be strengthened.

  The pair of external electrodes 19 are formed by printing silver on both sides of the laminate 18. Further, on the surface of the pair of external electrodes 19, a nickel plating layer and a plating layer made of a low melting point metal plating layer such as tin or solder on the surface of the nickel plating layer are formed.

  The first to fourth insulating layers 11a to 11d and the dummy insulating layer 11e may have a number and thickness different from the number and thickness shown in FIG. Alternatively, only the third insulating layer 11c may be made of a low magnetic permeability material or a nonmagnetic material, and the second and fourth insulating layers 11b and 11d may be made of a magnetic material. In this case, the first via electrode 16a, the second via electrode 16b, and the magnetic body portion 17 do not have to be separately formed in the second and fourth insulating layers 11b and 11d, so that productivity is improved. To do. Furthermore, the first to fourth conductors 12 to 15 may be formed by other methods such as printing or vapor deposition instead of forming by plating.

  As described above, in one embodiment of the present invention, the second to fourth insulating layers 11b to 11d made of a non-magnetic material are made of a magnetic material inside the second conductor 13 and the third conductor 14. Two magnetic body portions 17 are provided, and the first via electrode 16a and the second via electrode 16b are positioned between the two magnetic body portions 17 in a top view. It is not necessary to increase the size of the portion 17, so that the magnetic material does not fall out of the through-holes, or cracks are not generated around the magnetic body portion 17 during firing due to a difference in thermal shrinkage rate. The area of the two magnetic body portions 17 as a whole can be increased, whereby the effect of improving impedance can be obtained.

  Furthermore, when the lengths of the second conductor 13 and the third conductor 14 are changed, as shown by a broken line in FIG. 4, only one of the two magnetic body portions 17 is used instead of the entire two magnetic body portions 17. Since it is only necessary to go around the circumference, the number of turns can be changed by about every 0.5 turns, and the length can be lengthened, thereby obtaining the effect that the impedance can be easily adjusted. Since the number of turns can be changed every about 0.5 turns, it is possible to prevent the direct current resistance value from becoming higher than necessary and increasing the loss.

  That is, the magnetic body portion 17 does not occupy most of the inner portions of the second conductor 13 and the third conductor 14, and the number of turns of the second conductor 13 and the third conductor 14 can be adjusted. Can be adjusted.

  Further, in order to adjust the impedance, only the number of turns of the second conductor 13 and the third conductor 14 is adjusted instead of the size of the magnetic body portion 17, so that the magnetic body portion 17 of each type is adjusted. It is not necessary to prepare the first to fourth insulating layers 11a to 11d having different sizes.

  Here, it is not simply necessary to provide a plurality of magnetic body portions 17, and the portions where the first via electrodes 16 a and the second via electrodes 16 b are located in a top view are sandwiched as in the present invention. Since the second conductor 13 and the third conductor 14 can circulate around only one of the two magnetic body portions 17 as described above, the number of turns can be reduced. It can be changed every 0.5 turn. Furthermore, the number of turns can be changed every 0.5 turns by disposing the magnetic body portion 17 at a point-symmetrical position with respect to the portion where the first via electrode 16a and the second via electrode 16b are located. it can.

  One magnetic part 17 may be divided into two or more. At this time, a pair of each magnetic body portion 17 is provided across a portion where the first via electrode 16a and the second via electrode 16b are located in a top view.

  The common mode noise filter according to the present invention has the effect of improving the impedance and facilitating the adjustment of the impedance, and in particular, the noise of various electronic devices such as digital devices, AV devices and information communication terminals. This is useful in a common mode noise filter used as a countermeasure.

11a-11d 1st-4th insulating layer 12 1st conductor 13 2nd conductor 14 3rd conductor 15 4th conductor 16a, 16b 1st, 2nd via electrode 17 Magnetic body part

Claims (1)

A first conductor provided on an upper surface of the first insulating layer; a second insulating layer provided on an upper surface of the first conductor; and an upper surface of the second insulating layer and the first conductor A spiral second conductor connected to the second conductor, a third insulating layer provided on the upper surface of the second conductor, and a spiral third provided on the upper surface of the third insulating layer. A conductor, a fourth insulating layer provided on the top surface of the third conductor, and a fourth conductor provided on the top surface of the fourth insulating layer and connected to the third conductor. The first conductor and the second conductor are connected by a first via electrode formed in the second insulating layer, and the third conductor and the fourth conductor are connected to the fourth conductor. The second via electrode formed in the insulating layer is connected, and at least the third insulating layer is made of a nonmagnetic material, and the first In the insulating layer, two magnetic parts made of a magnetic material are provided inside the second conductor and the third conductor, and a first via electrode and a second electrode are provided between the two magnetic parts when viewed from above. Common mode noise filter in which the via electrode is located.

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