JP2008258525A - Common-mode noise filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common-mode noise filter capable of suppressing occurrence of cracks. <P>SOLUTION: A common-mode noise filter has a magnetic body 18 provided on an upper surface of a fifth insulating layer 11e and on an undersurface of a first insulating layer 11a, and a main body 19 configured by unifying first to fifth insulating layers 11a to 11e and first to fourth conducting bodies 12, 14, 15 and 17. At least the third insulating layer 11c among the first to fifth insulating layers 11a to 11e is configured by a non-magnetic body. In an insulating layer configured by the non-magnetic body, a magnetic part 20 made of a magnetic material, and a buffer 21 having a magnetic permeability lower than that of the magnetic part 20 are provided at any one of or both inner and outer sides of each of a first coil 22 and a second coil 23 as viewed from above. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  As shown in FIG. 5, the conventional common mode noise filter is provided with first to fourth conductors 2a, 2b, 3a, and 3b on the top surfaces of the first to fourth insulating layers 1a to 1d, respectively. The first coil 2 is formed by connecting the conductor 2a and the spiral second conductor 2b via the via 4a, and the spiral third conductor 3a and the fourth conductor 3b are connected to the via. The second coil 3 was formed by connecting via 4b, and the fifth insulating layer 1e made of a magnetic material was further provided on the upper surface of the fourth conductor 3b.

  The second insulating layer 1b to the fourth insulating layer 1d are made of a non-magnetic material, and the second insulating layer 1b to the fourth insulating layer 1d made of the non-magnetic material are spirally formed. One magnetic part 5 located inside the spiral of each of the second conductor 2b and the third conductor 3a is provided, the first insulating layer 1a is made of a magnetic material, and the magnetic part 5 is The first insulating layer 1a and the fifth insulating layer 1e are connected.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2001-76930 A

  In the above-described conventional common mode noise filter, the second to fourth insulating layers 1b to 1d and the magnetic part 5, the first insulating layer 1a, and the fifth insulating layer 1e are made of different materials. For this reason, stress is generated at these interfaces, which causes a problem that cracks are generated.

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

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

  According to a first aspect of the present invention, a first conductor provided on the upper surface of the first insulating layer, and a second insulation provided on the upper surface of the first conductor and having a first via. And a spiral second conductor that is provided on the upper surface of the second insulating layer and is connected to the first conductor via the first via to form a first coil; A third insulating layer provided on the upper surface of the second conductor, a spiral third conductor provided on the upper surface of the third insulating layer, and provided on the upper surface of the third conductor; A fourth coil is configured by a fourth insulating layer having a second via, and a second coil provided on the upper surface of the fourth insulating layer and connected to the third conductor via the second via. A fourth conductor, a fifth insulating layer provided on an upper surface of the fourth conductor, an upper surface of the fifth insulating layer, and a front surface A magnetic body provided on a lower surface of the first insulating layer; and a main body unit configured by integrating them; and at least a third insulating layer of the first to fifth insulating layers is made of a nonmagnetic material. A magnetic part made of a magnetic material on the inner side and / or the outer side of each of the first coil and the second coil in a top view in the insulating layer made of the non-magnetic material. And a buffer part having a lower magnetic permeability than the magnetic part. According to this configuration, the magnetic part is provided on either or both of the inner side and the outer side of the first coil and the second coil. Since the buffer part having lower permeability than the magnetic part is provided, the buffer part relieves stress generated between the insulating layer made of non-magnetic material and the magnetic part and the magnetic material part. This suppresses the generation of cracks Effect that wear are those that can be obtained.

  According to the second aspect of the present invention, in particular, the first to fifth insulating layers are made of a nonmagnetic material, and only the first insulating layer, the third insulating layer, and the fifth insulating layer are included. In which the magnetic part is not provided in the second insulating layer and the fourth insulating layer. According to this configuration, the first insulating layer, the third insulating layer, A magnetic part made of a magnetic material is provided only in the fifth insulating layer, and the magnetic part is not provided in the second insulating layer having the first via and the fourth insulating layer having the second via. Therefore, it is only necessary to provide vias in the second insulating layer and the fourth insulating layer, respectively. As a result, the second insulating layer and the fourth insulating layer can be easily configured. An effect is obtained.

  According to the third aspect of the present invention, in particular, the dielectric constant of the first to fifth insulating layers is made smaller than that of the magnetic substance. According to this configuration, the first conductor and the second conductor Since the stray capacitance generated between the first coil composed of the first conductor and the second coil composed of the third conductor and the fourth conductor can be reduced, the differential in the high frequency band can be reduced. The insertion loss of the signal can be reduced, thereby obtaining the effect that it can be used even in a high frequency band.

  In the invention according to claim 4 of the present invention, in particular, the second conductor and the third conductor are formed in a substantially circular shape. According to this configuration, the first coil and the second coil are formed. Since the distances from the central portions of the second conductors and the third conductors facing each other through the central portion of each other can be made substantially the same, the magnetic efficiency is increased, thereby removing the common mode noise. As a result, the effect of increasing is obtained.

  As described above, the common mode noise filter of the present invention is configured such that at least the third insulating layer of the first to fifth insulating layers is made of a nonmagnetic material, and the upper surface of the insulating layer is made of a nonmagnetic material. Since a magnetic part made of a magnetic material and a buffer part having a lower magnetic permeability than the magnetic part are provided on one or both of the inside and / or the outside of each of the first coil and the second coil as viewed. The stress generated between the insulating layer made of a non-magnetic material and the magnetic portion and the portion made of the magnetic material can be relieved by the buffering portion, which can suppress the generation of cracks. It is effective.

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

  1 is an exploded perspective view of a common mode noise filter according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, 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 and having a first via 13 and a first insulating layer 11b provided on the upper surface of the second insulating layer 11b and connected to the first conductor 12 via the first via 13 The spiral second conductor 14 formed, the third insulating layer 11c provided on the top surface of the second conductor 14, and the spiral third conductor provided on the top surface of the third insulating layer 11c. Conductor 15, a fourth insulating layer 11 d provided on the upper surface of the third conductor 15 and having the second via 16, and a second insulating layer provided on the upper surface of the fourth insulating layer 11 d and the second via A fourth conductor 17 connected to the third conductor 15 via 16; A fifth insulating layer 11e provided on the upper surface of the fourth conductor 17, a magnetic body 18 provided on the upper surface of the fifth insulating layer 11e and the lower surface of the first insulating layer 11a, and And a main body 19 constructed integrally.

  The first to fifth insulating layers 11a to 11e are made of a nonmagnetic material, and the second conductors in the first insulating layer 11a, the third insulating layer 11c, and the fifth insulating layer 11e are used. 14 and the third conductor 15 are provided with magnetic portions 20 made of a magnetic material at portions located inside and outside the third conductor 15, respectively, and the magnetic portions 20 of the second insulating layer 11b and the fourth insulating layer 11d A buffer part 21 having a lower permeability than the magnetic part 20 is formed by forming a through hole at a corresponding position.

  The said structure WHEREIN: The said 1st-5th insulating layers 11a-11e consist of an insulating material, and the 1st conductor 12 is on the upper surface of the 1st insulating layer 11a, and the 2nd insulating layer 11b. The second conductor 14 is formed on the upper surface of the first insulating layer, the third conductor 15 is formed on the upper surface of the third insulating layer 11c, and the fourth conductor 17 is formed on the upper surface of the fourth insulating layer 11d.

  The first to fifth insulating layers 11a to 11e are made of a nonmagnetic material containing glass such as glass ceramic, and these include the upper surface of the fifth insulating layer 11e and the first insulating layer 11e. It is made of a material having a lower magnetic permeability than the magnetic body 18 provided on the lower surface of the insulating layer 11a.

  The second insulating layer 11b and the fourth insulating layer 11d are not provided with the magnetic part 20 made of a magnetic material, but are provided with a buffer part 21 constituted by a through hole in a part corresponding to the magnetic part 20. It is what.

  Furthermore, the dielectric constants of the first to fifth insulating layers 11a to 11e are smaller than the dielectric constant of the magnetic body 18. In such a configuration, the first conductor 12 and the second conductor 12 Since the stray capacitance generated between the first coil 22 composed of the conductor 14 and the second coil 23 composed of the third conductor 15 and the fourth conductor 17 can be reduced, the high frequency band Thus, the insertion loss of the differential signal can be reduced, thereby obtaining the effect that it can be used even in a high frequency band.

  The first to fourth conductors 12, 14, 15, and 17 are formed by plating a conductive material such as silver, and the first conductor 12 and the second conductor 14 are a second insulating layer. The first coil 22 is configured by connecting via the first via 13 formed in 11b. Further, the third conductor 15 and the fourth conductor 17 are connected via a second via 16 formed in the fourth insulating layer 11d to constitute a second coil 23.

  The second conductor 14 and the third conductor 15 are formed in a spiral shape, and are substantially overlapped when viewed from above. And the shape of this 2nd conductor 14 and the 3rd conductor 15 is comprised by the substantially circular shape, and if it is such a structure, the 1st coil 22 and the 2nd coil 23 will be shown. Since the distances from the central portions of the second conductors 14 and the third conductors 15 facing each other through the central portion can be made substantially the same, the magnetic efficiency is increased. The removal effect is increased.

  The magnetic body 18 is made of a magnetic material such as Ni—Zn ferrite and is provided on the upper surface of the fifth insulating layer 11e and the lower surface of the first insulating layer 11a. The magnetic body 18 is formed by laminating a plurality of magnetic layers 18a.

  In addition, the magnetic unit 20 includes the second of the first, third, and fifth insulating layers 11a, 11c, and 11e among the first to fifth insulating layers 11a to 11e made of a nonmagnetic material. Ni—Zn is provided at both the inside and outside of the conductor 14 and the third conductor 15, that is, at positions located on both the inside and outside of the first coil 22 and the second coil 23 in a top view. It is made of a magnetic material such as ferrite. By forming the magnetic part 20, the magnetic field intersecting between the first coil 22 and the second coil 23 can be strengthened, so that the common mode component of the first coil 22 and the second coil 23 can be reduced. Impedance is increased, and thus more common mode noise can be removed.

  In the embodiment of the present invention described above, the magnetic part 20 is provided in each of the portions located on both the inside and outside of the second conductor 14 and the third conductor. 14 and the third conductor 15 may be provided only on either the inner side or the outer side.

  As shown in FIGS. 1 and 2, the buffer portion 21 corresponds to the magnetic portion 20 provided only in the first insulating layer 11a, the third insulating layer 11c, and the fifth insulating layer 11e, that is, The through hole is formed in the second insulating layer 11b and the fourth insulating layer 11d at a position overlapping the magnetic part 20 in a top view, and the inside of the through hole has an air permeability lower than that of the magnetic part 20 It has become.

  Further, the through hole may have a cross-sectional area smaller than the cross-sectional area of the magnetic part 20 at a position overlapping the magnetic part 20 in a top view of the second insulating layer 11b and the fourth insulating layer 11d. Also in this case, the permeability of the portion overlapping the magnetic part 20 in the top view of the second insulating layer 11b and the fourth insulating layer 11d is lower than that of the magnetic part 20.

  As shown in FIG. 4, the buffer portion 21 may be configured by filling a through hole with a nonmagnetic material having a lower magnetic permeability than the magnetic portion 20, a nonmagnetic glass ceramic material, or the like. Further, as a material filled in the through hole constituting the buffer portion 21, the same magnetic material as the nonmagnetic material constituting the first to fifth insulating layers 11a to 11e is used, which has a lower magnetic permeability than the magnetic portion 20. Is preferred. Further, the buffer portion 21 may not be a through hole but a recess that does not penetrate the insulating layer.

  In the embodiment of the present invention, since the second insulating layer 11b and the fourth insulating layer 11d themselves are made of a nonmagnetic material, the second insulating layer 11b and the fourth insulating layer A portion overlapping the magnetic part 20 in the top view of the layer 11d becomes a buffer part 21 having a lower magnetic permeability than the magnetic part 20, and thus it is not necessary to newly provide the buffer part 21 in the through hole. In this case, it is only necessary to provide the first via 13 and the second via 16 in the second insulating layer 11b and the fourth insulating layer 11d, respectively, and thereby the second insulating layer 11b and the fourth insulating layer 11d. The layer 11d can be easily configured.

  Note that at least one of the first, second, fourth, and fifth insulating layers 11a, 11b, 11d, and 11e may be made of a magnetic material, but in this case, it is not made of a magnetic material. What is necessary is just to form the magnetic part 20 and the buffer part 21 in an insulating layer.

  Further, the buffer portion 21 is not formed inside the first coil 22 and the second coil 23 in a top view, but the buffer portion 21 may be formed outside, and conversely the first coil. 22. Although the buffer part 21 is not formed outside the second coil 23, the buffer part 21 may be formed inside. In addition, when forming the buffer part 21 in the location located in both the inside and the outside of the first coil 22 and the second coil 23, if the buffer part 21 is formed in the same insulating layer, it is caused by shrinkage during firing. Stress can be released in a well-balanced manner.

  Therefore, any one of the magnetic part 20 and the buffer part 21 is located at both the inside and the outside of the first coil 22 and the second coil 23 in the top view of the first to fifth insulating layers 11a to 11e. Will be formed. That is, a part of the magnetic part 20 that penetrates the first to fifth insulating layers 11a to 11e in a straight line at a position located on both the inside and the outside of the first coil 22 and the second coil 23 is a buffer part. The configuration is changed to 21.

  And the main-body part 19 of a common mode noise filter as shown in FIG. 3 is formed by laminating | stacking the above-mentioned component. Further, first to fourth external electrodes 24 to 27 are provided on both sides of the main body 19, and the first to fourth external electrodes 24 to 27 are provided to the first to fourth electrodes. It is formed by printing silver so as to be connected to the conductors 12, 14, 15, and 17, respectively. Further, a nickel plating layer and a tin plating layer are respectively provided on the surfaces of the first to fourth external electrodes 24 to 27.

  The first to fourth conductors 12, 14, 15, and 17 may be formed by other methods such as printing or vapor deposition instead of being formed by plating.

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

  1 to 3, first, rectangular first to fifth insulating layers 11 a to 11 e and a magnetic layer 18 a are made of a mixture of magnetic material, glass, nonmagnetic material powder and resin as raw materials. A predetermined number of each is prepared. At this time, a predetermined portion of the second insulating layer 11b and the fourth insulating layer 11d is drilled with a laser, punching, or the like, and this hole is filled with silver, and the first and second vias 13, 16 is formed. The first, third, and fifth insulating layers 11a, 11c, and 11e have a second conductor 14, a portion corresponding to the inside of the third conductor 15, and four portions corresponding to the outside. A through hole is provided by laser, punching or the like.

  Next, a predetermined number of magnetic layers 18 a are stacked to form the magnetic body 18, and then the first insulating layer 11 a having a through hole is placed on the upper surface of the magnetic body 18.

  Next, a paste made of Ni—Zn ferrite or the like is embedded in the through hole of the first insulating layer 11 a and then dried to form the magnetic part 20.

  Next, the first conductor 12 is formed by plating on the upper surface of the first insulating layer 11a, and then the second insulating layer 11b having the first via 13 is placed on the upper surface of the first conductor 12. . At this time, one end of the first conductor 12 and the first via 13 are connected.

  Next, the second conductor 14 is spirally formed on the upper surface of the second insulating layer 11b by plating, and then the third insulating layer 11c having a through hole is placed on the upper surface of the second conductor 14. . At this time, one end of the second conductor 14 and the first via 13 are connected.

  Next, a paste made of Ni—Zn ferrite or the like is embedded in the through hole of the third insulating layer 11 c and then dried to form the magnetic part 20.

  Next, the third conductor 15 is formed in a spiral shape by plating on the upper surface of the third insulating layer 11c, and then the fourth insulating layer 11d having the second via 16 on the upper surface of the third conductor 15 is formed. Place. At this time, one end of the third conductor 15 and the second via 16 are connected.

  Next, the fourth conductor 17 is formed on the upper surface of the fourth insulating layer 11d by plating, and then the fifth insulating layer 11e having a through hole is placed on the upper surface of the fourth conductor 17. At this time, one end of the fourth conductor 17 and the second via 16 are connected.

  The first to fourth conductors 12, 14, 15, and 17 are formed by plating a conductor having a predetermined pattern shape on a separately prepared base plate (not shown). It is formed by transferring to an insulating layer.

  Next, a paste made of Ni—Zn ferrite or the like is embedded in the through hole of the fifth insulating layer 11 e and then dried to form the magnetic part 20.

  Next, the magnetic body 18 is formed by laminating a predetermined number of magnetic layers 18a on the upper surface of the fifth insulating layer 11e, and the main body 19 of the common mode noise filter is formed.

  Next, the main body 19 is fired at a predetermined temperature and time, and further, silver is connected to the first and fourth conductors 12, 14, 15, and 17 on both side surfaces of the main body 19. The first to fourth external electrodes 24 to 27 are formed by printing.

  Finally, a nickel plating layer and a tin plating layer are formed on the surfaces of the first to fourth external electrodes 24 to 27 by plating.

  As described above, in one embodiment of the present invention, in the first to fifth insulating layers 11a to 11e made of a non-magnetic material, the first coil 22 and the second coil 23 are viewed from above. Since the magnetic part 20 made of a magnetic material and the buffer part 21 having a lower magnetic permeability than the magnetic part 20 are provided on both the inner side and the outer side, the first to fifth parts made of a non-magnetic material are provided. The stress generated between the insulating layers 11a to 11e and the portion composed of the magnetic portion 20 and the magnetic body 18 can be relaxed by the buffer portion, thereby obtaining the effect of suppressing the occurrence of cracks. Is.

  That is, since the magnetic part 20 and the magnetic body 18 made of a magnetic material and the first to fifth insulating layers 11a to 11e made of a non-magnetic material are made of different materials, the magnetic part 20 is formed in a portion corresponding to the magnetic part 20. When the buffer part 21 is not provided, the interface between the magnetic part 20 and the magnetic body 18 made of a magnetic material and the first to fifth insulating layers 11a to 11e made of a non-magnetic material when firing is performed. However, as in the embodiment of the present invention, the buffer portion 21 is provided in the second insulating layer 11b and the fourth insulating layer 11d so as to correspond to the magnetic portion 20 as in the embodiment of the present invention. Since the stress at the interface between the magnetic part 20 and the magnetic body 18 made of a magnetic material and the first to fifth insulating layers 11a to 11e made of a nonmagnetic material can be reduced, Suppress the generation of cracks Can. Furthermore, since the magnetic part 20 is formed, the magnetic field intersecting between the first coil 22 and the second coil 23 can be strengthened, so that the common mode of the first coil 22 and the second coil 23 can be increased. The impedance of the component becomes large, so that more common mode noise can be removed. As a result, two effects of suppressing the occurrence of cracks and removing more common mode noise can be realized simultaneously.

  In the common mode noise filter according to the embodiment of the present invention, a pair of coils has been described. However, two or more pairs of coils may be formed to form an array type.

  A common mode noise filter according to the present invention includes a magnetic material on an inner layer and / or an outer side of each of a first coil and a second coil in an insulating layer made of a nonmagnetic material. By providing a magnetic part made of the above and a buffer part having a lower magnetic permeability than this magnetic part, it is possible to suppress the occurrence of cracks, and in particular, various electronic devices such as digital equipment, AV equipment, information communication terminals, etc. This is useful in a common mode noise filter or the like used as a noise countermeasure for equipment.

The disassembled perspective view of the common mode noise filter in one embodiment of this invention AA line sectional view of FIG. Perspective view of the common mode noise filter Sectional view showing the main part of the common mode noise filter Exploded perspective view of a conventional common mode noise filter

Explanation of symbols

11a to 11e First to fifth insulating layers 12 First conductor 13 First via 14 Second conductor 15 Third conductor 16 Second via 17 Fourth conductor 18 Magnetic body 19 Body portion 20 Magnetic portion 21 Buffer 22 First coil 23 Second coil

Claims (4)

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 having a first via; and an upper surface of the second insulating layer. A spiral second conductor constituting the first coil by being connected to the first conductor via the first via, and a second conductor provided on the upper surface of the second conductor. 3 insulating layers, a spiral third conductor provided on the top surface of the third insulating layer, and a fourth insulating layer provided on the top surface of the third conductor and having a second via A fourth conductor provided on an upper surface of the fourth insulating layer and connected to the third conductor via the second via to constitute a second coil; and the fourth conductor A fifth insulating layer provided on the upper surface of the first insulating layer; and an upper surface of the fifth insulating layer and a lower surface of the first insulating layer. And a main body unit formed by integrating them, and at least the third insulating layer of the first to fifth insulating layers is made of a nonmagnetic material, and is made of the nonmagnetic material. In the insulating layer, a magnetic part made of a magnetic material and a buffer having a lower magnetic permeability than the magnetic part on one or both of the inner side and the outer side of each of the first coil and the second coil in a top view. Common mode noise filter with The first to fifth insulating layers are made of a non-magnetic material, and a magnetic part is provided only in the first insulating layer, the third insulating layer, and the fifth insulating layer, and the second insulating layer and the second insulating layer The common mode noise filter according to claim 1, wherein the magnetic part is not provided in the insulating layer 4. 2. The common mode noise filter according to claim 1, wherein the dielectric constant of the first to fifth insulating layers is smaller than the dielectric constant of the magnetic material. The common mode noise filter according to claim 1, wherein the second conductor and the third conductor are formed in a substantially circular shape.

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