JP2017092434A - Common mode noise filter - Google Patents

Abstract

An object of the present invention is to provide a common mode noise filter capable of magnetically coupling three coils in a balanced manner.
A mon-mode noise filter according to the present invention includes a first coil conductor 15a constituting a first coil 15 in a first insulator layer 11 and a second coil 16 in a second insulator layer 12. The second coil conductor 16a constituting the third coil conductor 17a constituting the third coil 17 on the third insulator layer 13 and the fourth coil constituting the first coil 15 on the fourth insulator layer 14 are constituted. The first coil conductor 15a and the fourth coil conductor 15b are connected to each other, and the first coil conductor 15a and the second coil conductor 16a, and the second coil conductor 16a and the second coil conductor 15b are connected to each other. The third coil conductor 17a, the third coil conductor 17a, and the fourth coil conductor 15b overlap each other in a top view.
[Selection] Figure 4

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.

  Conventionally, the mobile industry processor interface (mpi) D-PHY standard has been adopted as a digital data transmission standard for connecting a main IC to a display or a camera in a mobile device, and the differential signal is transmitted using two transmission lines. The method is used. In recent years, the resolution of cameras has dramatically increased, and as a faster transmission method, three transmission lines are used to send different voltages from the transmission side to each transmission line, and the reception side takes the difference between each line. A differential output system is established as the mipiC-PHY standard and put into practical use.

  A conventional common mode noise filter of this type has a plurality of insulator layers 1 and three independent first to third coils 2 to 4 as shown in FIG. The coils 2 to 4 are formed by electrically connecting the coil conductors 2a and 2b, the coil conductors 3a and 3b, and the coil conductors 4a and 4b, respectively, and the three first to third coils 2 to 2 are formed. 4 were arranged in the stacking direction in order from the bottom. In such a configuration, when common mode noise is input, the first to third coils 2 to 4 operate as reinforcing inductances to suppress the noise.

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

JP 2003-77727 A

  In the above-described conventional common mode noise filter, since the second coil 3 is disposed between the first coil 2 and the third coil 4, the first coil 2, the third coil 4, and the like. Thus, the first coil 2 and the third coil 4 were hardly magnetically coupled.

  When such a filter is applied to the above-described three-wire differential signal line and a differential data signal is transmitted, magnetic flux generated in each of the first coil 2 and the third coil 4 that are not magnetically coupled. However, since a large residual inductance is generated with a component that is not magnetically coupled without being canceled, a loss occurs in the differential data signal, and the differential signal quality is greatly deteriorated.

  On the other hand, as shown in FIG. 15, the coil conductor 2a constituting the first coil 2, the coil conductor 3a constituting the second coil 3, the coil conductor 4a constituting the third coil 4, the first conductor The coil conductor 2b constituting the coil 2, the coil conductor 3b constituting the second coil 3, and the coil conductor 4b constituting the third coil 4 are laminated in this order, and the first coil 2 and the second coil 3 It is conceivable to increase the magnetic coupling by setting two locations where the two are adjacent to each other and two locations where the second coil 3 and the third coil 4 are adjacent to each other.

  However, in this case, the first coil 2 and the third coil 4 are in a state of sandwiching the second coil 3 and are further away from each other. The magnetic coupling between them has a problem that the balance becomes poor.

  When a differential signal is input to such a common mode noise filter, the second coil 3 is in good magnetic coupling with the first coil 2 and the third coil 4 that are close to each other. There is little degradation of motion signals. However, also in this configuration, the distance between the coil conductor 2b and the coil conductor 4b and the distance between the coil conductor 4a and the coil conductor 2a are separated and the magnetic coupling is weak. The problem that the differential signal which flows through the coil 4 will deteriorate will arise.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a common mode noise filter that can be magnetically coupled between three coils in a well-balanced manner and that does not deteriorate differential signals. .

  In order to solve the above-described object, the present invention includes first to fourth insulator layers stacked in order from the top and first to third coils that are independent from each other, and the first insulator layer includes The first coil conductor constituting the first coil, the second coil conductor constituting the second coil on the second insulator layer, and the third coil on the third insulator layer Forming a third coil conductor constituting the fourth coil conductor constituting the first coil on the fourth insulator layer, and connecting the first coil conductor and the fourth coil conductor; Furthermore, the first coil conductor and the second coil conductor, the second coil conductor and the third coil conductor, and the third coil conductor and the fourth coil conductor are respectively viewed from above. It is configured to overlap.

  The common mode noise filter of the present invention includes a first coil conductor constituting the first coil, a second coil conductor constituting the second coil, a second coil conductor constituting the second coil, and a third coil conductor. The third coil conductor constituting the first coil, the third coil conductor constituting the third coil, and the fourth coil conductor constituting the first coil overlap each other in a top view, and The second coil, the second coil and the third coil, and the third coil and the first coil can be magnetically coupled to each other in the same manner.

The top view of the principal part of the common mode noise filter in Embodiment 1 of this invention Main top view of the common mode noise filter according to the second embodiment of the present 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 Circuit diagram of the common mode noise filter The disassembled perspective view of the common mode noise filter in Embodiment 4 of this invention 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 5 of this invention Circuit diagram of the common mode noise filter Circuit configuration diagram of another example of the common mode noise filter The disassembled perspective view of the common mode noise filter in Embodiment 6 of this invention An exploded perspective view showing another example of the common mode noise filter Exploded perspective view of a conventional common mode noise filter An exploded perspective view showing another example of the common mode noise filter

(Embodiment 1)
FIG. 1 is a top view of the main part of the common mode noise filter according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the common mode noise filter according to the first exemplary embodiment of the present invention includes a first insulator layer 11, a second insulator layer 12, and a third insulator layer 13 that are stacked in order from the top. The fourth insulator layer 14, the spiral first coil conductor 15a formed in the first insulator layer 11, and the two spiral layers formed in the second insulator layer 12. The second coil conductors 16a and 16b, the two spiral third coil conductors 17a and 17b formed in the third insulator layer 13, and the spiral formed in the fourth insulator layer 14 And the fourth coil conductor 15b, the first coil conductor 15a and the fourth coil conductor 15b, the two second coil conductors 16a and 16b, the two third coil conductors 17a and 17b, Are independent of each other by electrically connecting The first coil 15, second coil 16, to form a third coil 17.

  In addition, in FIG. 1, the figure which looked at each insulator layer 11-14 with which the coil conductor was formed from the upper surface, respectively is shown. The same applies to FIG.

  In the above configuration, the first to fourth insulator layers 11 to 14 have substantially the same thickness, and are formed into a sheet-like non-magnetic material such as Cu—Zn ferrite or glass ceramic, or Ni—Cu—Zn. It is made of a magnetic material such as ferrite. The second insulator layer 12 is below the first insulator layer 11, the third insulator layer 13 is below the second insulator layer 12, and the fourth insulator is below the third insulator layer 13. The first to fourth insulator layers 11 to 14 are laminated.

  In addition, one first coil conductor 15a is formed on the first insulator layer 11, and two second coil conductors 16a and 16b are formed on the second insulator layer 12, respectively. The two third coil conductors 17a and 17b are each formed on the third insulator layer 13, and the fourth coil conductor 15b is formed on the fourth insulator layer 14. Yes. Further, by plating or printing a conductive material such as silver on the first to fourth insulator layers 11 to 14 in a spiral shape of one turn or more or less than one turn, the first to fourth coil conductors 15a. , 15b, 16a, 16b, 17a, and 17b.

  The first coil conductor 15a formed on the first insulator layer 11 and the second coil of one of the two second coil conductors 16a and 16b formed on the second insulator layer 12 are used. The conductor 16a overlaps the top view and is magnetically coupled to each other. Similarly, of the two second coil conductors 16 a and 16 b formed on the second insulator layer 12, the other second coil conductor 16 b and the two second coil conductors 16 b formed on the third insulator layer 13. One of the three coil conductors 17a and 17b overlaps with the third coil conductor 17a in a top view, and is magnetically coupled to each other, and further, two third coils formed in the third insulator layer 13 Of the conductors 17a and 17b, the other third coil conductor 17b and the fourth coil conductor 15b formed on the fourth insulator layer 14 overlap each other in a top view and are magnetically coupled to each other.

  The first coil 15 includes a first coil conductor 15a and a fourth coil conductor 15b, and the second coil 16 includes second coil conductors 16a and 16b formed on the same insulator layer 12. The third coil 17 is composed of third coil conductors 17 a and 17 b formed on the same insulator layer 13.

  Furthermore, the first coil conductor 15a and the fourth coil conductor 15b constituting the first coil 15 are connected to the via electrode 19a formed in the first to fourth insulator layers 11 to 14 and the fourth insulation. Electrical connection is established through a routing conductor 15 c formed in the fifth insulator layer 18 located below the body layer 14.

  The second coil conductors 16a and 16b constituting the second coil 16 are connected to the via electrode 19b formed in the second to fourth insulator layers 12 to 14 and the fifth insulator layer 18, respectively. It is electrically connected through the formed routing conductor 16c.

  Further, the third coil conductors 17a and 17b constituting the third coil 17 include a via electrode 19c formed on the third and fourth insulator layers 13 and 14 and a fifth insulator layer 18. It is electrically connected through a routing conductor 17c formed in

  With such a configuration, three independent first coil 15, second coil 16, and third coil 17 are provided, and first coil 15, second coil 16, second coil 16, and second coil 16 are provided. The three coils 17, the third coil 17, and the first coil 15 are magnetically coupled to each other at one location.

  At this time, the routing conductors 15c, 16c, and 17c constitute part of the first to third coils 15, 16, and 17, respectively.

  If necessary, other insulator layers are laminated on the upper and lower surfaces of the first to fifth insulator layers 11 to 14 and 18, and a laminated body (not shown) is formed by these configurations. . Moreover, six external electrodes (hereinafter not shown) connected to the end portions of the first to fourth coil conductors 15a, 15b, 16a, 16b, 17a, and 17c are provided on both end faces of the laminate. .

  The other insulator layers, the first to fifth insulator layers 11 to 14 and 18 may all be made of a nonmagnetic material, may be made of a magnetic material, or a combination thereof. There may be.

  As described above, in the common mode noise filter according to the first exemplary embodiment of the present invention, the first coil conductor 15a constituting the first coil 15 and the one second coil conductor 16a constituting the second coil 16. The other second coil conductor 16 b constituting the second coil 16, the third coil conductor 17 a constituting the third coil 17, and the other third coil conductor constituting the third coil 17. 17b and the fourth coil conductor 15b constituting the first coil 15 overlap each other in a top view at one place, so that the three coils can be similarly magnetically coupled to each other. Is obtained.

  Then, only two second coil conductors 16 a and 16 b constituting the second coil 16 are provided on the same plane of the second insulator layer 12, and the third plane is provided on the same plane of the third insulator layer 13. Since only the two third coil conductors 17a and 17b constituting the coil 17 are provided, the magnetic coupling in the lateral direction does not occur.

  Further, since the first coil 15, the second coil 16, and the third coil 17 are all composed of two coil conductors, the lengths of the three coils 15, 16, and 17 are made substantially the same. Can do.

  At this time, by adjusting the lengths of the routing conductors 15d, 16d, and 17d, the lengths of the three coils 15, 16, and 17 can be made close to each other.

  Further, since the three coils 15, 16, and 17 overlap with other coils in a top view as a part thereof, the stray capacitance can be reduced.

(Embodiment 2)
FIG. 2 is a top view of the main part of the common mode noise filter according to the second embodiment of the present invention, and FIG. 3 is a circuit configuration diagram of the common mode noise filter. 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, as shown in FIGS. 2 and 3, the first coil 15, the second coil 16, and the third coil 17 are used. The two coil conductors constituting each of the above are wired in parallel rather than in series.

  In such a configuration, one first coil conductor 15 a constituting the first coil 15, one second coil conductor 16 a constituting the second coil 16, and the other constituting the second coil 16. The second coil conductor 16 b and the third coil conductor 17 a constituting the third coil 17, the other third coil conductor 17 b constituting the third coil 17 and the other constituting the first coil 15. Since the fourth coil conductors 15b overlap each other when viewed from above, the three coils can be magnetically coupled with good balance.

  A case where the thus configured common mode noise filter is applied to a three-wire differential signal line is considered. When a differential signal including a pair of the first coil 15 and the second coil 16 is input (when a differential signal is input from the external electrodes 20a and 22a), the first coil conductor 15a and the second coil The coil conductor 16a is magnetically coupled so that the generated magnetic flux is canceled and the impedance becomes low, so that a differential signal can easily pass therethrough. On the other hand, in the fourth coil conductor 15b connected in parallel with the first coil conductor 15a, a signal component that cancels the generated magnetic flux does not flow in the third coil conductor 17b facing and magnetically coupled. For this reason, the fourth coil conductor 15b operates as an inductor and has a large impedance along with the frequency, so that the signal hardly flows.

  In addition, when a differential signal that makes a pair of the first coil 15 and the third coil 17 is input (when a differential signal is input from the external electrodes 20a and 21a), the fourth coil conductor 15b The third coil conductor 17b is magnetically coupled, so that the generated magnetic flux is canceled and the impedance becomes low, and the differential signal easily passes. On the other hand, in the first coil conductor 15a connected in parallel with the fourth coil conductor 15b, no signal component that cancels the generated magnetic flux flows in the second coil conductor 16a facing and magnetically coupled. Therefore, the first coil conductor 15a operates as an inductor, and has a large impedance with frequency, so that it is difficult for a signal to flow.

  That is, even if the first coil conductor 15a and the fourth coil conductor 15b are connected in parallel as the conductors constituting the first coil 15, another line that forms a differential signal is the second coil 16. Depending on which of the third coils 17, the main path through which the differential signal flows becomes the first coil conductor 15a or the fourth coil conductor 15b, and the loss of the differential signal is determined. Can be suppressed. With such a configuration, the first to third coils 15 to 17 can be magnetically coupled in a balanced manner, so that even when used as a three-wire differential signal line, the loss of the differential signal is small. Signal quality can be maintained.

  Further, since the two coil conductors constituting the first coil 15, the second coil 16, and the third coil 17 are wired in parallel, the DC resistance value (frequency zero component) can be lowered. And signal loss can be prevented.

(Embodiment 3)
FIG. 4 is an exploded perspective view of the common mode noise filter according to Embodiment 3 of the present invention. FIG. 5 shows a circuit configuration diagram of the common mode noise filter according to the third embodiment of the present invention.

  As shown in FIG. 4, the common mode noise filter according to the third embodiment of the present invention includes a first insulator layer 11, a second insulator layer 12, and a third insulator layer 13 that are stacked in order from the top. A fourth insulator layer 14, a spiral first coil conductor 15a formed on the first insulator layer 11, and one spiral formed on the second insulator layer 12. Second coil conductor 16a, one spiral third coil conductor 17a formed on the third insulator layer 13, and spiral formed on the fourth insulator layer 14 And a fourth coil conductor 15b, the second coil conductor 16a constitutes the second coil 16, the third coil conductor 17a constitutes the third coil 17, and the first coil conductor 15a. And the fourth coil conductor 15b are electrically connected to each other. The first coil 15 is constituted by the. The first coil 15, the second coil 16, and the third coil 17 are independent of each other.

  In the above configuration, the first to fourth insulator layers 11 to 14 have substantially the same thickness, and are formed into a sheet-like non-magnetic material such as Cu—Zn ferrite or glass ceramic, or Ni—Cu—Zn. It is made of a magnetic material such as ferrite. The second insulator layer 12 is below the first insulator layer 11, the third insulator layer 13 is below the second insulator layer 12, and the fourth insulator is below the third insulator layer 13. The first to fourth insulator layers 11 to 14 are laminated.

  One first coil conductor 15a is formed on the first insulator layer 11, and one second coil conductor 16a is formed on the second insulator layer 12. The third coil conductor One 17 a is formed on the third insulator layer 13, and one fourth coil conductor 15 b is formed on the fourth insulator layer 14.

  That is, only the first coil 15 is divided into a first coil conductor 15a and a fourth coil conductor 15b that are connected in parallel, and one first coil conductor 15a is divided into the second coil 16 (second coil conductor). The other fourth coil conductor 15b is disposed below the third coil 17 (third coil conductor 17a) above 16a). Therefore, from the top, the first coil 15 (first coil conductor 15a), the second coil 16 (second coil conductor 16a), the third coil 17 (third coil conductor 17a), the first coil The coils 15 (fourth coil conductors 15b) are arranged in this order.

  Then, the first coil conductor 15a and the second coil conductor 16a adjacent in the vertical direction overlap in a top view and are magnetically coupled. Similarly, the second coil conductor 16a and the third coil conductor 17a adjacent in the vertical direction overlap in a top view and are magnetically coupled, and the third coil conductor 17a and the fourth coil conductor 15b adjacent in the vertical direction are Overlapping and magnetically coupled in top view.

  With such a configuration, three independent first coil 15, second coil 16, and third coil 17 are provided, and first coil 15, second coil 16, second coil 16, and second coil 16 are provided. The third coil 17, the third coil 17, and the first coil 15 are opposed to each other and magnetically coupled.

  Furthermore, by plating or printing a conductive material such as silver on the first to fourth insulator layers 11 to 14 in a spiral shape of one turn or more or less than one turn, the first to fourth coil conductors 15a, 16a, 17a, 15b are configured.

  Further, on the lower surface of the fourth insulator layer 14, the first coil 15 (first coil conductor 15a, fourth coil conductor 15b), second coil 16 (second coil conductor 16a), Lead conductors 15c, 16c, and 17c connected to the third coil 17 (third coil conductor 17a), respectively, are formed on the lower surfaces of the lead conductors 15c, 16c, and 17c. A body layer 18 is formed.

  The first to fifth insulator layers 11 to 14 and 18 may all be made of a nonmagnetic material, may be made of a magnetic material, or a combination thereof.

  Here, the second coil conductor 16a and the lead conductor 16c are connected via a via electrode 19b, and the third coil conductor 17a and the lead conductor 17c are connected via a via electrode 19c. The coil conductor 15a, the fourth coil conductor 15b, and the lead conductor 15c are connected via a via electrode 19a. The connection between the first coil conductor 15a and the fourth coil conductor 15b is also made through the via electrode 19a.

  If necessary, other insulator layers are laminated on the upper and lower surfaces of the first to fifth insulator layers 11 to 14 and 18, and a laminated body (not shown) is formed by these configurations. . Further, six external electrodes (one of the first to fourth coil conductors 15a, 16a, 17a, 15b and one end of the lead conductors 15c, 16c, 17c) are connected to both end faces of the laminate. Hereinafter, not shown) is provided. One end of the first coil conductor 15a and one end of the fourth coil conductor 15b are connected to the same external electrode, and are connected in parallel.

  As described above, the common mode noise filter according to the third embodiment of the present invention is different from the common mode noise filter according to the second embodiment in that the first to third coils 15 to 17 are stacked so as to overlap in a top view. The first coil 15 is connected in parallel to the first and fourth coil conductors 15a and 15b, and the second coil 16 and the third coil conductor 15b are connected between the first coil conductor 15a and the fourth coil conductor 15b. By arranging the coil 17, as shown in the second embodiment, the second coil 16 and the third coil 17 need to be divided into two coil conductors 16a and 16b and coil conductors 17a and 17b, respectively, and connected in parallel. There is no.

  That is, when operating as a three-wire differential signal line, the second coil 16 is magnetically coupled to the third coil 17 in the same manner as in the second embodiment, and the first coil 15 The coil conductor 15a is also magnetically coupled. Since the third coil 17 is magnetically coupled to the second coil 16 and is also magnetically coupled to the fourth coil conductor 15b of the first coil 15, when a differential signal is input, low-loss differential transmission is performed. It works with the path and does not degrade the differential signal.

  In the third embodiment, the number of stacked layers can be reduced as compared with the second embodiment, and the size can be reduced by arranging one type of coil per layer. From another point of view, if the area is the same as in the second embodiment, the number of turns of the coil can be increased. Therefore, when common mode noise is input, the impedance becomes high impedance with a large inductance, and the common mode The effect that noise can be removed can be obtained.

  In the present embodiment, the coil conductor is composed of four layers, but such a unit of four-layer coil conductors may be arranged in a plurality of layers and cascaded to form a multistage filter.

(Embodiment 4)
FIG. 6 is an exploded perspective view of a common mode noise filter according to Embodiment 4 of the present invention. In the fourth embodiment of the present invention, the same components as those of the third embodiment of the present invention described above are denoted by the same reference numerals, and the description thereof is omitted.

  The fourth embodiment of the present invention differs from the third embodiment of the present invention described above in that, as shown in FIG. 6, the lead conductors 15c, 16c, 17c are not formed, This is the point that the first coil 15, the second coil 16, and the third coil 17 having the same configuration as in the third embodiment are provided. That is, the first to fourth coil conductors 15a, 16a, 17a, 15b according to the third embodiment are also formed and stacked below.

  At this time, the first coil 15 has a parallel structure of a fifth coil conductor 15d and a sixth coil conductor 15e, and the second coil 16 is interposed between the fifth coil conductor 15d and the sixth coil conductor 15e. The seventh coil conductor 16d that constitutes the third coil 17 and the eighth coil conductor 17d that constitutes the third coil 17 are configured. Further, the fifth coil conductor 15d and the fourth coil conductor 15b are adjacent to each other. The seventh coil conductor 16 d constituting the second coil 16 is positioned below the eighth coil conductor 17 d constituting the third coil 17.

  Furthermore, the fifth coil conductor 15d and the sixth coil conductor 15e are connected to the first coil conductor 15a and the fourth coil conductor 15b through the via electrode 19a. The seventh coil conductor 16d is connected to the second coil conductor 16a via the via electrode 19b, and the eighth coil conductor 17d is connected to the third coil conductor 17a via the via electrode 19c. Further, the adjacent fifth coil conductor 15d and fourth coil conductor 15b are connected through another via electrode 19d.

  That is, a configuration in which two common mode noise filters according to the third embodiment are laminated is a circuit configuration diagram as shown in FIG.

  Further, the first, fourth, and fifth elements constituting the first coil 15 with respect to the central portion in the stacking direction (the insulator layer 14 between the fourth coil conductor 15b and the fifth coil conductor 15d). The sixth coil conductors 15a, 15b, 15d, and 15e are positioned in line symmetry, and the second and seventh coil conductors 16a and 16d constituting the second coil 16 are also positioned in line symmetry, and the third coil The third and eighth coil conductors 17a and 17d that constitute 17 are also positioned symmetrically. That is, the second and seventh coil conductors 16a and 16d constituting the second coil 16 sandwich the third coil conductor 17a and the eighth coil conductor 17d constituting the third coil 17, and the third A configuration in which the first and second coil conductors 17a and 17d constituting the coil 17 constitute the first coil 15 and the fourth coil conductor 15b and the fifth coil conductor 15d located in the center in the stacking direction are sandwiched therebetween. It has become.

  In such a configuration, since the fourth coil conductor 15b and the fifth coil conductor 15d have the same potential, the generation of stray capacitance between the two coil conductors 15b and 15d is suppressed, and the first coil 15 is When a single line is used, the deterioration of the differential signal passing therethrough hardly occurs.

  Furthermore, when a differential signal is input to the first coil 15 and the third coil 17 as a three-wire differential signal line, the passage path of the differential signal is the third coil conductor 17a and the fourth coil. Between the lines of the coil conductor 15b and between the lines of the eighth coil conductor 17d and the fifth coil conductor 15d, in this passing path, the magnetic flux generated in each coil is canceled, so that the impedance becomes low, and the third A potential difference hardly occurs between the pair of conductors of the coil conductor 17a and the fourth coil conductor 15b and the pair of conductors of the eighth coil conductor 17d and the fifth coil conductor 15d. Even when a pair conductor is considered, stray capacitance is less likely to be generated between the pair conductors, thereby suppressing the deterioration of the differential signal. For example, when the seventh coil conductor 16d and the eighth coil conductor 17d are switched, a differential signal is input to the first coil 15 and the third coil 17 as a three-wire differential signal line. Since the differential signal component that cancels the magnetic flux does not flow in the seventh coil conductor 16d that faces the fifth coil conductor 15d, the fifth coil conductor 15d and the seventh coil conductor 16d As the impedance increases and the frequency increases, a potential difference occurs, stray capacitance occurs, and the differential signal deteriorates.

  Also in the fourth embodiment, when operating as a three-wire differential signal line, the loss of the differential signal is small and the signal quality can be maintained by the same action as in the second and third embodiments.

  As shown in FIG. 8, the first coil conductor 15a and the fourth coil conductor 15b connected in parallel, and the fifth coil conductor 15d and the sixth coil conductor 15e are connected via the via electrodes 19a, respectively. Thus, the number of via electrodes may be reduced.

(Embodiment 5)
FIG. 9 is an exploded perspective view of the common mode noise filter according to the fifth embodiment of the present invention. Note that in the fifth embodiment of the present invention, components having the same configurations as those of the third embodiment of the present invention described above are denoted by the same reference numerals, and description thereof is omitted. FIG. 10 is a circuit configuration diagram of the common mode noise filter according to the fifth embodiment of the present invention.

  As shown in FIG. 9, the fifth embodiment of the present invention is different from the third embodiment of the present invention in that it is connected in parallel with the second coil conductor 16a above the first coil conductor 15a. In addition, another coil conductor (seventh coil conductor 16d) is provided, and further, the first insulator layer 11, the fourth insulator layer 14, and the first and seventh coil conductors 15a and 16d are disposed above the first coil conductor 15d. 7 in that the insulator layer 21 is made of a magnetic material.

  That is, an insulator layer made of a magnetic material is formed between the first coil conductor 15a and the second coil conductor 16a and in the uppermost lower layer.

  At this time, the seventh coil conductor 16d is formed on the upper surface of the sixth insulator layer 20 made of a nonmagnetic material, and the first to fourth coil conductors 15a, 15b, 16a, 16d, 17a, The other non-magnetic layer 22 is formed between the 17b and the routing conductors 15c, 16c, and 17c and the seventh insulator layer 21 made of a magnetic material. The first to fourth insulator layers 11 to 14 are made of a nonmagnetic material.

  In this configuration, the distance between the magnetic body and the first coil 15 (first and fourth coil conductors 15a and 15b), the magnetic body and the second coil 16 (second and seventh coil conductors 16a and 16d). , And the distance between the magnetic body and the third coil 17 (third coil conductor 17a) is also relatively close, so that the impedance value of each coil is close. When a differential signal is input as a signal line, the common mode filter unit configured by magnetically coupling the seventh coil conductor 16d and the first coil conductor 15a, the second coil conductor 16a and the third coil conductor 16a When the common mode filter unit configured by magnetically coupling the coil conductor 17a and the common mode filter unit configured by magnetically coupling the third coil conductor 17a and the first coil conductor 15a are operated, By signal It is possible to reduce the loss due to components that can not be magnetically coupled due to the difference in coil inductance variation of the differential signal passing through the respective common mode filter portion is reduced.

  Furthermore, as shown in FIG. 11, when the positions of the first coil conductor 15a and the seventh coil conductor 16d are switched, the opposing second coil conductor 16a and seventh coil conductor 16d have the same potential. The generation of stray capacitance between the two coil conductors 16a and 16d is suppressed, and the deterioration of the differential signal that passes when the second coil 16 is made one line is less likely to occur.

(Embodiment 6)
FIG. 12 is an exploded perspective view of a common mode noise filter according to Embodiment 6 of the present invention. Note that in the sixth embodiment of the present invention, components having the same configurations as those of the above-described second embodiment of the present invention are denoted by the same reference numerals, and description thereof is omitted.

  The sixth embodiment of the present invention is different from the above-described second embodiment of the present invention in that two second coil conductors 16a and 16b are arranged in the stacking direction as shown in FIG. Three coil conductors 17a and 17b are arranged in the stacking direction, and further, between the seventh insulator layer 21 and the two third coil conductors 17a and 17b located between the two second coil conductors 16a and 16b. The seventh insulator layer 21, the seventh insulator layer 21 above the first coil conductor 15a, and the seventh insulator layer 21 below the fourth coil conductor 15b are made of a magnetic material. It is.

  At this time, the first to fourth coil conductors 15a, 15b, 16a, 16d, 17a, 17b and the routing conductors 15c, 16c, 17c are respectively connected to the seventh insulator layer 21 made of a magnetic material. Another nonmagnetic material layer 22 is formed therebetween. The first to fourth insulator layers 11 to 14 are made of a nonmagnetic material.

  The two second coil conductors 16a and 16b are connected to each other, the two third coil conductors 17a and 17b are connected to each other, the first coil conductor 15a and the fourth coil conductor 15b are connected to each other with an external electrode (not shown). Is going through.

  These connections may be made by via electrodes 19a, 19b, 19c. Since the via electrodes 19a, 19b, and 19c penetrate the magnetic layer 21, impedance due to magnetic material characteristics is generated in the via electrodes 19a, 19b, and 19c in the low frequency region, so that noise in the low frequency region is attenuated. Can do.

  In the above-described configuration, the common mode filter portion composed of the first coil conductor 15a, the one second coil conductor 16a, and the routing conductor 15c is sandwiched between the magnetic layers 21, and the other second coil conductor. 16b, one third coil conductor 17a and the routing conductor 16c is sandwiched between the magnetic layers 21, and the other third coil conductor 17b and the fourth coil conductor 15b are connected to each other. Since the common mode filter section composed of the winding conductors 17c is sandwiched between the magnetic bodies 21, the characteristics of the three common mode filter sections are substantially equal, whereby the common mode noise removal characteristics between the coils, And a variation between pass characteristics of each differential signal when passing through each common mode filter when a differential signal is input as a three-wire differential signal line That.

  Further, as shown in FIG. 13, the routing conductor 15c is disposed between the first coil conductor 15a and one of the second coil conductors 16a to form a common mode filter portion, and the routing conductor 16c. Is arranged between the second coil conductor 16b and one of the third coil conductors 17a to form a common mode filter portion, and the routing conductor 17c is connected to the third coil conductor 17b and the fourth coil conductor 15b. By arranging the common mode filter portions in between, the three common mode filter portions are sandwiched between the magnetic layers 21, and each common mode filter portion sandwiched between the magnetic layers 21 is Because of the symmetry in the stacking direction, the impedance of each coil can be made substantially equal, which makes it possible to reduce the common mode noise removal characteristics between the coils and the three-wire type. It is possible to further reduce variation between pass characteristics of each differential signal when passing through each common mode filter when a differential signal is input as a dynamic signal line between each of the three common mode filters. it can.

  The common mode noise filter according to the present invention has an effect that three coils in a three-wire differential signal line can be magnetically coupled in a well-balanced manner, and in particular, a digital device, an AV device, and an information communication terminal. It is useful in a small and thin common mode noise filter used for the

DESCRIPTION OF SYMBOLS 11 1st insulator layer 12 2nd insulator layer 13 3rd insulator layer 14 4th insulator layer 15 1st coil 15a 1st coil conductor 15b 4th coil conductor 16 2nd coil 16a, 16b Second coil conductor 17 Third coil 17a, 17b Third coil conductor

Claims (11)

The first to fourth insulator layers stacked in order from the top and the first to third coils independent from each other, the first insulator constituting the first coil in the first insulator layer A coil conductor, a second coil conductor constituting the second coil in the second insulator layer, a third coil conductor constituting the third coil in the third insulator layer, the fourth Forming a fourth coil conductor constituting the first coil on the insulator layer, connecting the first coil conductor and the fourth coil conductor, and further, the first coil conductor and the A common mode noise filter in which the second coil conductor, the second coil conductor and the third coil conductor, and the third coil conductor and the fourth coil conductor overlap each other in a top view. The common mode noise filter according to claim 1, wherein the first coil conductor and the fourth coil conductor are connected in parallel. Two second coil conductors are formed on the second insulator layer, two third coil conductors are formed on the third insulator layer, and further, the first coil conductor and the second coil conductor are formed. And the other one of the second coil conductors and the other one of the third coil conductors are overlapped with each other in a top view, and the other one of the third coil conductors and the The common mode noise filter according to claim 1, wherein at least a part of each of the fourth coil conductors overlaps with each other when viewed from above. The first coil conductor and the fourth coil conductor constituting the first coil are connected in parallel, the second coil conductor constituting the second coil is connected in parallel, and the third coil conductor is connected in parallel. The common mode noise filter according to claim 3, wherein the third coil conductors constituting the coil are connected in parallel. A plurality of common mode noise filters according to claim 2 are formed in the stacking direction, the first and fourth coil conductors constituting the first coil, and the second coil constituting the second coil. A common mode noise filter in which the conductors and the third coil conductors constituting the third coil are connected to each other. The common mode noise filter according to claim 5, wherein the third coil conductor constituting the third coil is sandwiched between the second coil conductors constituting the second coil in the stacking direction. Another coil conductor connected in parallel with the second coil conductor is provided above the first coil conductor, the first coil conductor and the fourth coil conductor are connected in parallel, and the first coil conductor is connected in parallel. The common mode noise filter according to claim 1, wherein an insulator layer, the fourth insulator layer, the first coil conductor, and an insulator layer above the other coil conductors are made of a magnetic material. The common mode noise filter according to claim 7, wherein the other coil conductor is provided below the first coil conductor. Connecting the first and fourth coil conductors constituting the first coil in parallel, forming the two second coil conductors constituting the second coil and connecting them in parallel; Two third coil conductors constituting a third coil are formed and connected in parallel to each other, the two second coil conductors are arranged in a stacking direction, and the two third coil conductors are stacked. An insulator layer positioned between the two second coil conductors, an insulator layer positioned between the two third coil conductors, an insulator layer above the first coil conductor, The common mode noise filter according to claim 1, wherein the insulator layer below the fourth coil conductor is made of a magnetic material. 10. The first and fourth coil conductors, the second two coil conductors, and the two third coil conductors are not directly brought into contact with the insulator layer made of the magnetic material. Common mode noise filter as described. The common mode noise filter according to claim 9, wherein the arrangement of the two coil conductors sandwiched between the insulator layers made of the magnetic material is symmetric in the stacking direction.

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