JP2005340611A - Common mode noise filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common mode noise filter which can prevent an insulating failure or migration from occurring between a first coil and a second coil, and further can increase an impedance of common mode components of the first coil and the second coil. <P>SOLUTION: The common mode noise filter has a first coil 20 composed of a first conductor 12 and a spiral second conductor 14, a spiral third conductor 16 provided on an upper face of a third insulating layer 15 on an upper face of the second conductor 14, a second coil 21 composed of a third conductor 16 and a fourth conductor 18, and a fifth insulating layer 19 provided on an upper face of the fourth conductor 18. A first insulating layer 11 and the fifth insulating layer 19 are constituted of a magnetic body, and second to fourth insulating layers 13, 15, 17 are constituted of a non-magnetic body. Also, a thickness of the third insulating layer 15 is thicker than thicknesses of the second and fourth insulating layers 13, 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a small and stacked common mode noise filter used in various electronic devices.

  FIG. 7 is an exploded perspective view of a conventional common mode noise filter.

  As shown in FIG. 7, the conventional common mode noise filter has spiral first to fourth conductors 2a, 2b, 3a, and 3b on the upper surfaces of the first to fourth insulating layers 1a to 1d, respectively. The first coil 2 is formed by connecting the first conductor 2a and the second conductor 2b via the via electrode 4a, and the third conductor 3a and the fourth conductor 3b are connected to the via. The second coil 3 was formed by connecting through the electrode 4b.

  Further, a fifth insulating layer 5 made of a magnetic material is provided on the lower surface of the first insulating layer 1a and the upper surface of the fourth conductor 3b, respectively, and further, the second insulating layer 1b to the fourth insulating layer 1d are provided. Is made of a non-magnetic material, and the first insulating layer 1a and the fifth insulating layer 5 are made of a magnetic material.

  With the configuration as described above, the second conductor 2b and the third conductor 3a facing each other with the third insulating layer 1c interposed therebetween are magnetically coupled, whereby the first coil 2 and the second conductor 2a are magnetically coupled. The impedance of the common mode component of the coil 3 is increased to remove common mode noise.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2000-190410 A

  In the above-described conventional common mode noise filter, when the thickness of the third insulating layer 1c is thin, it is between the second conductor 2b and the third conductor 3a provided via the third insulating layer 1c. That is, there is a possibility that insulation failure, migration, or the like occurs between the first coil 2 and the second coil 3. Further, when the thickness of the second insulating layer 1b and the fourth insulating layer 1d is thick, the distance between the first insulating layer 1a and the second conductor 2b, the fifth provided on the upper surface of the fourth conductor 1d. Since the distance between the first insulating layer 5 and the third conductor 3a becomes longer, the magnetic fields generated in the first insulating layer 1a and the fifth insulating layer 5 cannot be used effectively, and the first coil 2 and second There is a problem that the impedance of the common mode component of the coil 3 may not be increased.

  The present invention solves the above-described conventional problems, and can prevent the occurrence of poor insulation, migration, or the like between the first coil and the second coil. It is an object of the present invention to provide a common mode noise filter capable of increasing the impedance of the common mode component of the second coil.

  To achieve the above object, according to the present invention, the first insulating layer and the fifth insulating layer are made of a magnetic material, and the second to fourth insulating layers are made of a non-magnetic material. Since the thickness of the insulating layer is greater than the thickness of the second insulating layer and the fourth insulating layer, and the thickness of the third insulating layer can be increased, the insulating layer is provided via the third insulating layer. Insulation failure, migration, etc. can be prevented between the second conductor and the third conductor, that is, between the first coil and the second coil. Since the thickness of the insulating layer and the fourth insulating layer can be reduced, the distance between the first insulating layer and the second conductor and the distance between the fifth insulating layer and the third conductor can be shortened, respectively. Effective use of the magnetic field generated in the first and fifth insulating layers composed of magnetic bodies Because, the first coil, in which the action and effect that it is possible to increase the impedance of the common mode component of the second coil can be obtained.

  As described above, the present invention provides the first conductor provided on the upper surface of the first insulating layer, the second insulating layer provided on the upper surface of the first conductor, and the second insulating layer. A spiral second conductor provided on the upper surface and connected to the first conductor to form a first coil with the first conductor, and a third provided on the upper surface of the second conductor An insulating layer, a spiral third conductor provided on the upper surface of the third insulating layer, a fourth insulating layer provided on the upper surface of the third conductor, and the fourth insulating layer A fourth conductor which is connected to the third conductor and forms a second coil with the third conductor, and a fifth insulation provided on the upper surface of the fourth conductor. A first insulating layer, and a first to a fourth extraction electrode connected to one end of each of the first to fourth conductors. And the fifth insulating layer is made of a magnetic material, the second to fourth insulating layers are made of a non-magnetic material, and the thickness of the third insulating layer is set to be the second insulating layer and the fourth insulating layer. Since the thickness of the insulating layer is larger than that of the first insulating layer, the thickness of the third insulating layer can be increased, whereby the second conductor and the third conductor provided via the third insulating layer. , I.e., the occurrence of insulation failure, migration, etc. between the first coil and the second coil, and the thicknesses of the second and fourth insulating layers. Since the distance between the first insulating layer and the second conductor and the distance between the fifth insulating layer and the third conductor can be shortened, the first insulation composed of a magnetic body can be reduced. Since the magnetic field generated in the layer and the fifth insulating layer can be effectively used, the first coil, the second In which an effect that it is possible to increase the impedance of the common mode component of yl.

  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 FIG. 1, the common mode noise filter according to one embodiment of the present invention is provided with a first conductor 12 provided on the upper surface of the first insulating layer 11 and an upper surface of the first conductor 12. Of the formed second insulating layer 13, a spiral second conductor 14 provided on the upper surface of the second insulating layer 13 and connected to the first conductor 12, and the second conductor 14 A third insulating layer 15 provided on the upper surface, a spiral third conductor 16 provided on the upper surface of the third insulating layer 15, and a fourth provided on the upper surface of the third conductor 16. An insulating layer 17, a fourth conductor 18 provided on the upper surface of the fourth insulating layer 17 and connected to the third conductor 16, and a fifth conductor 18 provided on the upper surface of the fourth conductor 18. The insulating layer 19 is provided.

  A first coil 20 is constituted by the first conductor 12 and the second conductor 14 connected to the first conductor 12, and is connected to the third conductor 16 and the third conductor 16. The second coil 21 is configured by the fourth conductor 18 thus formed.

  The first insulating layer 11 and the fifth insulating layer 19 are made of a magnetic material, and the second insulating layer 13, the third insulating layer 15 and the fourth insulating layer 17 are made of a non-magnetic material. is doing.

  In addition, the thickness of the third insulating layer 15 is larger than the thickness of the second insulating layer 13 and the fourth insulating layer 17.

In the above configuration, the first insulating layer 11 is formed in a sheet shape from a magnetic material such as ferrite based on Fe ₂ O ₃ and has an insulating property.

  The first conductor 12 is formed by plating a conductive material such as silver, and is provided on the upper surface of the first insulating layer 11. A first lead electrode 22 exposed at the side of the first insulating layer 11 is connected to one end of the first conductor 12.

  The second insulating layer 13 is formed in a sheet shape from a non-magnetic material such as Cu—Zn ferrite or glass ceramic, has an insulating property, and is provided on the upper surface of the first conductor 12. Yes. A first via electrode 23 is formed at the center of the second insulating layer 13. The first via electrode 23 is connected to the other end portion 12 a of the first conductor 12.

  The second conductor 14 is formed by plating a conductive material such as silver in a spiral shape, and is provided on the upper surface of the second insulating layer 13. Further, a second extraction electrode 24 exposed at the side of the second insulating layer 13 is connected to one end of the second conductor 14. Further, the other end portion 14 a of the second conductor 14, that is, the central portion of the spiral is connected to the first via electrode 23, whereby the first conductor electrode 23 is connected to the first via electrode 23. Since the other end portion 12a of the conductor 12 and the other end portion 14a of the second conductor 14 are electrically connected, the first conductor 12 and the second conductor 14 are connected. A first coil 20 composed of the first conductor 12 and the second conductor 14 is formed.

  The third insulating layer 15 is formed in a sheet shape from a nonmagnetic material such as Cu—Zn ferrite or glass ceramic, has an insulating property, and is provided on the upper surface of the second conductor 14. Yes.

  The third insulating layer 15 is thicker than the second insulating layer 13 and the fourth insulating layer 17.

  Furthermore, since the second conductor 14 and the third conductor 16 that are adjacent in the vertical direction through the third insulating layer 15 exert a magnetic influence on each other, the first coil 20 and the second coil Thus, the impedance of the common mode component of the first coil 20 and the second coil 21 can be increased.

  The third conductor 16 is formed by plating a conductive material such as silver in a spiral shape, and is provided on the upper surface of the third insulating layer 15. In addition, a third extraction electrode 25 exposed at the side of the third insulating layer 15 is connected to one end of the third conductor 16. Further, the third conductor 16 is opposed so that most of the third conductor 16 overlaps with the second conductor 14 through the third insulating layer 15 in a top view.

  The fourth insulating layer 17 is formed in a sheet shape from a nonmagnetic material such as Cu—Zn ferrite or glass ceramic, has an insulating property, and is provided on the upper surface of the third conductor 16. Yes. A second via electrode 26 is formed at the center of the fourth insulating layer 17. The second via electrode 26 is connected to the other end 16a of the third conductor 16, that is, the center of the spiral.

  The fourth conductor 18 is formed by plating a conductive material such as silver, and is provided on the upper surface of the fourth insulating layer 17. In addition, a fourth lead electrode 27 exposed at the side of the fourth insulating layer 17 is connected to one end of the fourth conductor 18. The other end 18a of the fourth conductor 18, that is, the center of the spiral is connected to the second via electrode 26, whereby the third conductor 18 is connected to the third via the second via electrode 26. Since the other end 16a of the conductor 16 and the other end 18a of the fourth conductor 18 are electrically connected, the third conductor 16 and the fourth conductor 18 are connected. A second coil 21 composed of the third conductor 16 and the fourth conductor 18 is formed. The impedance of the first coil 20 and the second coil 21 can be increased by making the second conductor 14 and the third conductor 16 spiral. The first via electrode 23 and the second via electrode 26 are formed by filling a hole penetrating the second insulating layer 13 and a hole penetrating the fourth insulating layer 17 with a conductor such as silver, respectively. It is composed.

The fifth insulating layer 19 is formed in a sheet shape from a magnetic material such as ferrite based on Fe ₂ O ₃ , has an insulating property, and is provided on the upper surface of the fourth conductor 18. ing.

  Here, when the second insulating layer 13, the third insulating layer 15, and the fourth insulating layer 17 are made of a ferrite-based material as the nonmagnetic material, the first insulating layer 11 and the fifth insulating layer are used. Since it becomes ferrite together with 19, even if each insulating layer is fired simultaneously, the bondability of each insulating layer is improved and a stable product can be obtained.

  A dummy insulating layer 28 is provided on the lower surface of the first insulating layer 11 and the upper surface of the fifth insulating layer 19, and this dummy insulating layer 28 is formed in a sheet shape and has an insulating property. However, the material may be either a magnetic material or a non-magnetic material. Further, the number of the first to fifth insulating layers 11, 13, 15, 17, 19, and the dummy insulating layer 28 is not limited to the number shown in FIG.

  And the noise filter main-body part 29 is formed by the above-mentioned structure. The first to fourth external electrodes 30, 31, 32, 33 are provided on both side surfaces of the noise filter main body 29, and the first to fourth external electrodes 30, 31, 32, 33 are provided. Are connected to the first to fourth extraction electrodes 22, 24, 25, 27, respectively.

  As described above, since the second conductor 14 and the third conductor 16 that are adjacent to each other in the vertical direction and have a magnetic influence on each other are spiral, the length of the conductor that has a magnetic influence on each other is long. In addition, since the first to fourth conductors 12, 14, 16, and 18 that constitute the first coil 20 and the second coil 21 and generate a magnetic field are provided in a non-magnetic material, magnetic flux leakage Thus, the magnetic coupling between the first coil 20 and the second coil 21 is strengthened, and the magnetic fields of the first insulating layer 11 and the fifth insulating layer 19 having magnetism are increased. As a result, the impedance of the common mode component of the first coil 20 and the second coil 21 is increased.

  The shapes of the first conductor 12 and the fourth conductor 18 are not particularly limited as long as the impedance of the common mode noise component is not reduced. However, if the shape is as shown in FIG. The impedance of the differential component of the first conductor 12 and the fourth conductor 18 is lowered, and the impedance of the common mode component can be increased accordingly.

  The first to fourth extraction electrodes 22, 24, 25, and 27 are also formed by plating a conductive material such as silver. In this case, the first to fourth extraction electrodes 22, 24, 25, and 27 are formed. Is preferably made of the same material at the same time as the first to fourth conductors 12, 14, 16, 18. Note that the first to fourth conductors 12, 14, 16, 18 and the first to fourth extraction electrodes 22, 24, 25, 27 are not formed by plating, but other methods such as printing and vapor deposition. May be formed.

  As shown in FIG. 3, a magnetic portion 34 made of a magnetic material may be provided inside the spirals of the second conductor 14 and the third conductor 16 in the third insulating layer 15. At this time, the magnetic portion 34 is formed inside the innermost conductor of the spiral second conductor 14 and the third conductor 16 and is in contact with the second conductor 14 and the third conductor 16. It is provided not to.

  In this case, the third insulating layer 15 located between the first coil 20 and the second coil 21, that is, between the second conductor 14 and the third conductor 16 that are magnetically coupled to each other, Since a magnetic material can be provided and thereby a magnetic field intersecting between the first coil 20 and the second coil 21 can be strengthened, the common mode component of the first coil 20 and the second coil 21 can be increased. The impedance can be increased. In particular, when the thickness of the third insulating layer 15 is increased as in the present invention, the distance between the first coil 20 and the second coil 21 is long. It can be said that the magnetic field which crosses between 20 and the 2nd coil 21 is weak, and can be said to be a very effective structure. Further, if the magnetic part 34 and the via electrodes 23 and 26 made of different materials are not provided in the same insulating layer, the magnetic part 34 or the via electrodes 23 and 26 can be easily formed.

  Further, as shown in FIG. 4, the fourth extraction electrode 27 may be provided on the same surface of the first insulating layer 11 provided with the first extraction electrode 22, and in this case, the second extraction electrode 22 The via electrode 26 is provided on the second insulating layer 13 and the third insulating layer 15, and the fourth conductor 18 and the fourth lead electrode 27 are provided on the upper surface of the first insulating layer 11. It is necessary to connect the other end 16a of the first conductor 16 and the fourth conductor 18. In FIG. 4, the fourth extraction electrode 27 is not shown because it is hidden behind the second insulating layer 13. Further, the first extraction electrode 22 may be provided on the same surface of the fourth insulating layer 17 provided with the fourth extraction electrode 27. Also in this case, since the first extraction electrode 22 and the fourth extraction electrode 27 are provided in the same plane, the first extraction electrode 22 and the fourth extraction electrode 27 are also magnetically coupled to each other. As a result, the magnetic coupling between the first coil 20 and the second coil 21 is strengthened, so that the impedance of the common mode component can be further increased.

  Furthermore, the width of each of the first to fourth lead electrodes 22, 24, 25, 27 may be wider than the width of each of the first to fourth conductors 12, 14, 16, 18 as described above. In this case, since it is possible to reduce the magnetic influence of the first to fourth conductors 12, 14, 16, 18 that are not related to the magnetic coupling between the first coil 20 and the second coil 21, Most of the portions to be magnetically coupled can be the second conductor 14 and the third conductor 16 that have a magnetic influence on each other, whereby the impedance of the common mode component can be further increased.

  In addition, the width of each of the first conductor 12 and the fourth conductor 18 may be wider than the width of the second conductor 14 and the third conductor 16, and in this case, Since the impedance of the differential mode component generated in the conductor 12 and the fourth conductor 18 can be reduced, the impedance of the common mode component of the first coil 20 and the second coil 21 can be further increased accordingly.

  Next, the manufacturing method of the common mode noise filter in one embodiment of the present invention will be described.

  In FIG. 1 and FIG. 2, first, rectangular first to fifth insulating layers 11, 13, 15, 17, 19, A predetermined number of dummy insulating layers 28 are formed. At this time, holes are drilled at predetermined locations of the second insulating layer 13 and the fourth insulating layer 17 by laser, punching or the like, and the holes are filled with silver, whereby the first and second via electrodes 23 are filled. , 26 are formed. Further, the thickness of the third insulating layer 15 is made larger than the thickness of the second insulating layer 13 and the fourth insulating layer 17.

  Next, the first insulating layer 11 is disposed on the upper surface of the predetermined number of dummy insulating layers 28.

  Next, the first conductor 12 and the first extraction electrode 22 are formed on the upper surface of the first insulating layer 11 by plating.

  Next, the second insulating layer 13 provided with the first via electrode 23 is disposed on the upper surface of the first conductor 12. At this time, the other end portion 12a of the first conductor 12 and the first via electrode 23 are connected.

  Next, the spiral second conductor 14 and the second extraction electrode 24 are formed on the upper surface of the second insulating layer 13 by plating. At this time, the other end portion 14 a of the second conductor 14 and the first via electrode 23 are connected.

  Next, the third insulating layer 15 is disposed on the upper surface of the second conductor 14.

  Next, the spiral third conductor 16 and the third extraction electrode 25 are formed on the upper surface of the third insulating layer 15 by plating.

  Next, the fourth insulating layer 17 provided with the second via electrode 26 is disposed on the upper surface of the third conductor 16. At this time, the other end 16a of the third conductor 16 and the second via electrode 26 are connected.

  Next, the fourth conductor 18 and the fourth extraction electrode 27 are formed on the upper surface of the fourth insulating layer 17 by plating. At this time, the other end 18a of the fourth conductor 18 and the second via electrode 26 are connected.

  In addition, the formation method of the 1st conductor 12, the 2nd conductor 14, the 3rd conductor 16, and the 4th conductor 18 forms the conductor of a predetermined pattern shape by plating on the base plate (not shown) prepared separately. Then, the conductor is formed by transferring it to each insulating layer.

  Next, the fifth insulating layer 19 is disposed on the upper surface of the fourth conductor 18, and then a predetermined number of dummy insulating layers 28 are disposed on the upper surface of the fifth insulating layer 19, so that the noise filter main body 29 is disposed. Form.

  In the above manufacturing process, after providing a plurality of first conductors 12, second conductors 14, third conductors 16, and fourth conductors 18 in each insulating layer in order to improve manufacturing efficiency. Alternatively, a plurality of noise filter main bodies 29 may be obtained at the same time by cutting into individual pieces.

  Next, the noise filter main body 29 is fired at a predetermined temperature and time.

  Next, the first to fourth external electrodes are printed on both side surfaces of the noise filter main body 29 by printing silver so as to be connected to the first to fourth extraction electrodes 22, 24, 25, 27, respectively. 30, 31, 32, and 33 are formed.

  Finally, a nickel plating layer is formed on the surfaces of the first to fourth external electrodes 30, 31, 32, 33 by plating, and a low melting point metal plating layer such as tin or solder is further formed on the surface of the nickel plating layer by plating. Form.

  In the above-described embodiment of the present invention, the first conductor 12 provided on the upper surface of the first insulating layer 11, the second insulating layer 13 provided on the upper surface of the first conductor 12, A spiral second conductor 14 provided on the upper surface of the second insulating layer 13 and connected to the first conductor 12 to form the first coil 20 with the first conductor 12; A third insulating layer 15 provided on the upper surface of the second conductor 14, a spiral third conductor 16 provided on the upper surface of the third insulating layer 15, and the third conductor 16 The second coil 21 is formed by the fourth insulating layer 17 provided on the upper surface and the third conductor 16 provided on the upper surface of the fourth insulating layer 17 and connected to the third conductor 16. A fourth conductor 18 to be configured, and a fifth insulating layer 1 provided on the upper surface of the fourth conductor 18 And first to fourth extraction electrodes 22, 24, 25, 27 respectively connected to one end portions of the first to fourth conductors 12, 14, 16, 18, The insulating layer 11 and the fifth insulating layer 19 are made of a magnetic material, and the second to fourth insulating layers 13, 15, and 17 are made of a non-magnetic material, and the thickness of the third insulating layer 15 is made. Is made thicker than the thickness of the second insulating layer 13 and the fourth insulating layer 17, the thickness of the third insulating layer 15 can be increased. It is possible to prevent insulation failure, migration, and the like from occurring between the second conductor 14 and the third conductor 16 provided via the first conductor 20, that is, between the first coil 20 and the second coil 21. Furthermore, the thickness of the second insulating layer 13 and the fourth insulating layer 17 can be reduced. Thus, the distance between the first insulating layer 11 and the second conductor 14 and the distance between the fifth insulating layer 19 and the third conductor 16 can be shortened, respectively. The magnetic fields generated in the insulating layer 11 and the fifth insulating layer 19 can be effectively used, and as a result, the impedance of the common mode component of the first coil 20 and the second coil 21 can be increased. .

  Here, FIG. 5 shows the thicknesses of the second insulating layer 13 and the fourth insulating layer 17 and the first coil 20 and the second coil 21 in the common mode noise filter according to the embodiment of the present invention. It is a figure which shows the relationship with a coupling coefficient.

  At this time, a common mode noise filter having the structure shown in FIG. 1 in which the thickness of the third insulating layer 15 was 24 μm was produced as a sample. Those having a coupling coefficient of 0.94 or less were regarded as defective. In addition, the impedance of the common mode component of the 1st coil 20 and the 2nd coil 21 can be enlarged, so that this coupling coefficient is large.

  As can be seen from FIG. 5, the thicknesses of the second insulating layer 13 and the fourth insulating layer 17 need to be 20 μm or less. This is because if the thickness is greater than 20 μm, the magnetic fields of the first insulating layer 11 and the fifth insulating layer 19 having magnetism cannot be effectively used.

  Further, the lower limit value of the thickness of the second insulating layer 13 and the fourth insulating layer 17 may be appropriately determined according to the required characteristics, but is preferably set to 5 μm or more in consideration of ease of handling. . At this time, even if the second insulating layer 13 is thinner than 20 μm, the first conductor 12 and the second conductor 14 provided above and below the second insulating layer 13 have the same potential, so that the insulation failure, etc. The problem does not occur much. The same applies to the fourth insulating layer 17.

  FIG. 6 is a diagram showing the relationship between the thickness of the third insulating layer 15 and the insulation failure occurrence rate in the embodiment of the present invention.

At this time, a common mode noise filter having the structure shown in FIG. 1 in which the thickness of the second insulating layer 13 and the fourth insulating layer 17 was 17 μm was prepared as a sample. Then, 5 V was continuously applied under conditions of an ambient temperature of 125 ° C., a humidity of 85%, and a pressure of 2 atm, and those having an insulation resistance of 10 ⁷ Ω or less were regarded as defective.

  In FIG. 6, A indicates that the thickness of the third insulating layer 15 is 17 μm, B indicates 20 μm, and C indicates 24 μm.

  As apparent from FIG. 6, insulation failure occurred in A after 36 hours, but insulation failure did not occur in B and C even after 60 hours. That is, it can be seen that the thickness of the third insulating layer 15 needs to be 20 μm or more. On the other hand, if the thickness is less than 20 μm, not only insulation failure occurs between the second conductor 14 and the third conductor 16, but also the possibility of occurrence of migration or the like increases.

  Further, the upper limit value of the thickness of the third insulating layer 15 may be determined as appropriate according to the required characteristics. However, the magnetic coupling between the first coil 20 and the second coil 21, the thickness of the entire product, etc. Considering, for example, 50 μm or less is preferable.

  In the common mode noise filter according to the embodiment of the present invention, one first coil 20 and one second coil 21 are provided. However, each of the first coil 20 and the second coil 21 is provided. A plurality of array types may be used.

  The common mode noise filter according to the present invention can prevent the occurrence of insulation failure, migration, or the like between the first coil and the second coil, and further includes the first coil and the second coil. The impedance of the common mode component can be increased, and it is useful as a noise filter used as a noise countermeasure for mobile phones, information devices and the like.

The disassembled perspective view of the common mode noise filter in one embodiment of this invention Perspective view of the common mode noise filter An exploded perspective view showing another example of the common mode noise filter An exploded perspective view showing still another example of the common mode noise filter The figure which shows the relationship between the thickness of a 2nd insulating layer and a 4th insulating layer, and the coupling coefficient of a 1st coil and a 2nd coil in the common mode noise filter The figure which shows the relationship between the thickness of a 3rd insulating layer, and the insulation failure incidence in the common mode noise filter Exploded perspective view of a conventional common mode noise filter

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st insulating layer 12 1st conductor 13 2nd insulating layer 14 2nd conductor 15 3rd insulating layer 16 3rd conductor 17 4th insulating layer 18 4th conductor 19 5th insulating layer 20 1st coil 21 2nd coil 22 1st extraction electrode 24 2nd extraction electrode 25 3rd extraction electrode 27 4th extraction electrode 34 Magnetic part

Claims (6)

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 that is connected to the first conductor to form a first coil with the first conductor, a third insulating layer provided on an upper surface of the second conductor, and the third conductor A spiral third conductor provided on the upper surface of the insulating layer; a fourth insulating layer provided on the upper surface of the third conductor; and an upper surface of the fourth insulating layer and A fourth conductor which is connected to the third conductor and constitutes a second coil with the third conductor, a fifth insulating layer provided on the upper surface of the fourth conductor, and the first to first First to fourth lead electrodes respectively connected to one end of each of the four conductors, and the first insulating layer and the fifth insulating layer are magnetically connected to each other. And the second to fourth insulating layers are made of a nonmagnetic material, and the thickness of the third insulating layer is made larger than the thickness of the second insulating layer and the fourth insulating layer. Common mode noise filter. The common mode noise filter according to claim 1, wherein the thickness of the third insulating layer is 20 μm or more, and the thickness of the second insulating layer and the fourth insulating layer is 20 μm or less. The common mode noise filter according to claim 1, wherein a magnetic part made of a magnetic material is provided inside the spiral of the second conductor and the third conductor in the third insulating layer. The common mode noise filter according to claim 1, wherein the first extraction electrode and the fourth extraction electrode are provided on the same surface of the first insulating layer or the fourth insulating layer. The common mode noise filter according to claim 1, wherein each of the first to fourth extraction electrodes has a width wider than each of the first to fourth conductors. The common mode noise filter according to claim 1, wherein the width of each of the first conductor and the fourth conductor is wider than the width of each of the second conductor and the third conductor.

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