JP2009231307A - Common mode noise filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common mode noise filter capable of suppressing short-circuit defects. <P>SOLUTION: The common mode noise filter includes: a plurality of insulating layers 11, 13, 15 and 17; first to fourth conductors 12, 14, 16 and 18 provided in the plurality of insulating layers 11, 13, 15 and 17; and first to fourth electrodes 23, 25, 26 and 28 for pull-out provided on one end of each of the first to fourth conductors 12, 14, 16 and 18. The first conductor 12 and the second conductor 14 are connected, the third conductor 16 and the fourth conductor 18 are connected, the shape of the second conductor 14 and the third conductor 16 is turned to a helical shape and they are made to face each other. Also, the second conductor 14 and the first electrode 23 for pull-out are formed so as not to overlap in the upper surface view, and the third conductor 16 and the fourth electrode 28 for the pull-out are formed so as not to overlap in the upper surface view. <P>COPYRIGHT: (C)2010,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. 6, the conventional common mode noise filter of this type has first to fourth conductors 2a, 2b, 3a, 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 spiral second conductor 2b via the via electrode 4a, and the spiral third conductor 3a and the fourth conductor 4a are connected. The second coil 3 is formed by connecting the second conductor 3b to the second conductor 3b via the via electrode 4b, and the fifth insulating layer 1e is provided on the upper surface of the fourth conductor 3b. Further, the first insulating layer 1a and the fifth insulating layer 1e are made of a magnetic material, and the second insulating layer 1b to the fourth insulating layer 1d are made of a non-magnetic material.

  By configuring as described above, the magnetic field intersecting between the first coil 2 and the second coil 3 is strengthened, and the impedance of the common mode component of the first coil 2 and the second coil 3 is increased. Thus, common mode noise is removed.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2003-1224028 A

  The above-described conventional common mode noise filter has a problem that a short circuit defect occurs. That is, as shown in FIG. 7, since a part of the third conductor 3a and the extraction electrode 3c of the fourth conductor 3b overlap with each other in a top view, the third conductor 3a If the distance to the fourth conductor 3b is shortened (the thickness of the fourth insulating layer 1d is reduced), there is a possibility that the third conductor 3a and the fourth conductor 3b may be short-circuited. The same applies to the relationship between the first conductor 2a and the second conductor 2b.

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

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

  According to a first aspect of the present invention, a plurality of insulating layers, first to fourth conductors provided on the plurality of insulating layers, and one end of each of the first to fourth conductors are provided. Provided with first to fourth extraction electrodes provided, connecting the first conductor and the second conductor, connecting the third conductor and the fourth conductor, and the second conductor The conductor and the third conductor are formed in a spiral shape and opposed to each other, and the second conductor and the first extraction electrode are formed so as not to overlap each other when viewed from above, and the third conductor and the third conductor The four extraction electrodes are formed so as not to overlap with each other when viewed from above. According to this configuration, the first conductor and the second conductor and the third conductor and the fourth conductor are overlapped when viewed from above. Since the area to be reduced can be reduced, the first conductor and the second conductor and the third conductor and the second conductor Even when the thickness of the insulating layer between the conductors, it is possible to suppress the occurrence of short circuit. Further, since the facing area between the first conductor and the second conductor and the facing area between the third conductor and the fourth conductor can be reduced, the distance between the first conductor and the second conductor and between the third conductor and the second conductor can be reduced. Thus, the stray capacitance generated between the four conductors is reduced, thereby obtaining the effect that the common mode impedance can be increased to the high frequency region.

  According to the second aspect of the present invention, in particular, the portion of the second conductor located near the first extraction electrode in the top view and the fourth of the third conductor in the top view. The portion located in the vicinity of the lead electrode is configured in a curved shape or a C-plane shape. According to this configuration, since the magnetic path length of the coil does not change greatly, the impedance of the common mode component is changed. This eliminates this problem and provides the effect of suppressing short-circuit defects.

  As described above, the common mode noise filter of the present invention includes a plurality of insulating layers, first to fourth conductors provided in the plurality of insulating layers, and one end portions of the first to fourth conductors. First to fourth extraction electrodes provided on the first conductor and connecting the first conductor and the second conductor, connecting the third conductor and the fourth conductor, The second conductor and the third conductor are spirally shaped and opposed to each other, and the second conductor and the first extraction electrode are formed so as not to overlap in a top view. Since the fourth extraction electrode is formed so as not to overlap in the top view, the overlapping area in the top view of the first conductor and the second conductor and the third conductor and the fourth conductor is reduced. Thereby reducing the height between the first conductor and the second conductor and the third conductor. In the case of reducing the thickness of the insulating layer between the body and the fourth conductor it is also one in which an excellent effect that it is possible to suppress the occurrence of short circuit.

  1 is an exploded perspective view of a common mode noise filter according to an embodiment of the present invention, FIG. 2 is a perspective view of the common mode noise filter, and FIG. 3 is a relationship between a third conductor and a fourth conductor in a top view. FIG. FIG. 3 shows only the relationship between the third conductor and the fourth conductor in a top view for the sake of simplicity.

  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 and the first conductor 12. A second insulating layer 13 provided on the upper surface, 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 A third insulating layer 15 provided on the upper surface of the conductor 14, a spiral third conductor 16 provided on the upper surface of the third insulating layer 15, and an upper surface of the third conductor 16. Provided on the upper surface of the fourth insulating layer 17 and connected to the third conductor 16, and on the upper surface of the fourth conductor 18. And a fifth insulating layer 19 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. It is what you are doing.

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 23 exposed at the end of the first insulating layer 11 is connected to one end of the first conductor 12. Note that the width of the first extraction electrode 23 is wider than the width 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 24 is formed at the center of the second insulating layer 13. The first via electrode 24 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. Also, a second lead electrode 25 exposed at the end of the second insulating layer 13 is connected to one end of the second conductor 14, and the width of the second lead electrode 25. Is wider than the width 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 24, so that the first conductor electrode 24 is connected to the second via electrode 24. Since the other end 12a of the first conductor 12 and the other end 14a of the second conductor 14 are electrically connected, the first conductor 12 and the second conductor 14 are connected. Thus, the first coil 20 including the first conductor 12 and the second conductor 14 is formed.

  The first lead electrode 23 formed at one end of the first conductor 12 is formed so as not to overlap the second conductor 14 in a top view.

  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 may be provided with a magnetic portion made of a magnetic material so as to be positioned inside the spirals of the second conductor 14 and the third conductor 16 at the center thereof.

  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. A third lead electrode 26 exposed at the end of the third insulating layer 15 is connected to one end of the third conductor 16, and the width of the third lead electrode 26. Is wider than the width 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.

  Since the second conductor 14 and the third conductor 16 that are adjacent in the vertical direction via 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 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 27 is formed at the center of the fourth insulating layer 17. The second via electrode 27 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. Further, a fourth lead electrode 28 exposed at the end of the fourth insulating layer 17 is connected to one end of the fourth conductor 18, and the width of the fourth lead electrode 28. Is wider than the width of the fourth conductor 18. Further, the other end portion 18 a of the fourth conductor 18 is connected to the second via electrode 27, so that the third conductor 16 can be connected to the other end via the second via electrode 27. Since the end portion 16a and the other end portion 18a of the fourth conductor 18 are electrically connected, the third conductor 16 and the fourth conductor 18 are connected, whereby the third conductor A second coil 21 composed of 16 and the fourth conductor 18 is formed. In this case, the impedances of the first coil 20 and the second coil 21 can be increased by forming the second conductor 14 and the third conductor 16 in a spiral shape. The first via electrode 24 and the second via electrode 27 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.

  As shown in FIG. 3, the fourth lead electrode 28 formed at one end of the fourth conductor 18 is formed so as not to overlap with the third conductor 16 in a top view.

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 29 is provided on each of the lower surface of the first insulating layer 11 and the upper surface of the fifth insulating layer 19, and the dummy insulating layer 29 is formed in a sheet shape and has an insulating property. However, the material may be composed of 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 29 is not limited to the number shown in FIG.

  And the noise filter main-body part 30 is formed by the above-mentioned structure. The first to fourth external electrodes 31, 32, 33, 34 are provided on both end faces of the noise filter main body 30, and the first to fourth external electrodes 31, 32, 33, 34 are provided. Are connected to the first to fourth lead electrodes 23, 25, 26, 28, 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 formed in a spiral shape, the length of the conductor that has a magnetic influence on each other is formed. Furthermore, since the magnetic fields of the first insulating layer 11 and the fifth insulating layer 19 having magnetism can be effectively utilized, the impedance of the common mode component of the first coil 20 and the second coil 21 can be reduced. It will be bigger.

  The first to fourth extraction electrodes 23, 25, 26, 28 are also formed by plating a conductive material such as silver. In this case, the first to fourth extraction electrodes are used. The electrodes 23, 25, 26, and 28 are preferably formed of the same material simultaneously with the first to fourth conductors 12, 14, 16, and 18. The first to fourth conductors 12, 14, 16, 18 and the first to fourth extraction electrodes 23, 25, 26, 28 are not formed by plating, but other printing, vapor deposition, or the like. You may form by the method of.

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

  1 to 3, first, rectangular first to fifth insulating layers 11, 13, 15, 17, and a mixture of powders, resins, and solvents of magnetic materials and nonmagnetic materials that are raw materials are used. 19. A predetermined number of dummy insulating layers 29 are prepared. At this time, holes are formed in predetermined portions 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 24 are filled. , 27 are formed.

  Next, the first insulating layer 11 is laminated on the upper surface of the predetermined number of dummy insulating layers 29.

  Next, the first conductor 12 and the first extraction electrode 23 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 24 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 24 are connected.

  Next, the spiral second conductor 14 and the second extraction electrode 25 are formed on the upper surface of the second insulating layer 13 by plating. At this time, the other end portion 14a of the second conductor 14 and the first via electrode 24 are connected. In addition, the first extraction electrode 23 and the second conductor 14 are formed so as not to overlap each other when viewed from above.

  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 26 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 27 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 27 are connected.

  Next, the fourth conductor 18 and the fourth lead electrode 28 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 27 are connected. Further, the fourth extraction electrode 28 and the third conductor 16 are formed so as not to overlap each other when viewed from above.

  In addition, the formation method of the 1st conductor 12, the 2nd conductor 14, the 3rd conductor 16, and the 4th conductor 18 is plating the conductor of a predetermined pattern shape on the base plate (not shown) prepared separately. Then, the conductor is formed by transferring the conductor 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 29 are disposed on the upper surface of the fifth insulating layer 19, and the noise filter main body 30. Form.

  In the above manufacturing process, a plurality of first conductors 12, second conductors 14, third conductors 16, and fourth conductors 18 are provided in each insulating layer in order to improve manufacturing efficiency. Thereafter, a plurality of noise filter main bodies 30 may be obtained simultaneously by cutting into individual pieces.

  Next, the noise filter main body 30 is fired at a predetermined temperature and time.

  Next, silver is printed on both end faces of the noise filter main body 30 so as to be connected to the first to fourth extraction electrodes 23, 25, 26, and 28, respectively. Electrodes 31, 32, 33, and 34 are formed.

  Finally, a nickel plating layer (not shown) is formed on the surfaces of the first to fourth external electrodes 31, 32, 33, and 34 by plating, and tin, solder, and the like are further plated on the surface of the nickel plating layer. A low melting point metal plating layer (not shown) is formed.

  In the above-described embodiment of the present invention, the second conductor 14 and the first extraction electrode 23 are formed so as not to overlap each other when viewed from above, and the third conductor 16 and the fourth extraction electrode are formed. 28 is formed so as not to overlap with each other when viewed from above, so that the overlapping area is reduced when the first conductor 12, the second conductor 14, and the third conductor 16, and the fourth conductor 18 are viewed from above. In order to reduce the height, the second insulating layer 13 between the first conductor 12 and the second conductor 14 and the fourth conductor 16 between the third conductor 16 and the fourth conductor 18 can be provided. Even in the case where the thickness of the insulating layer 17 is reduced, it is possible to obtain an effect that the occurrence of short-circuit defects can be suppressed.

  That is, since the widths of the first extraction electrode 23 and the fourth extraction electrode 28 are wide, the second conductor 14 and the first extraction electrode 23 overlap each other when viewed from above. When the third conductor 16 and the fourth extraction electrode 28 overlap with each other when viewed from above, the overlapping area increases, and thus there is a high possibility that a short-circuit failure occurs. If the first extraction electrode 23 and the fourth extraction electrode 28 do not overlap with the second conductor 14 and the third conductor 16 in a top view as in the embodiment of the present invention, Even if the widths of the first extraction electrode 23 and the fourth extraction electrode 28 remain wide, the occurrence of short-circuit defects can be suppressed. If the widths of the first extraction electrode 23 and the fourth extraction electrode 28 are wide, poor connection with the first to fourth external electrodes 31, 32, 33, 34 can be reduced. It is.

  Further, since the facing area between the second conductor 14 constituting the first coil 20 and the first extraction electrode 23 connected to the first conductor 12 can be reduced, the stray capacitance in the first coil 20 can be reduced. In addition, since the opposing area between the third conductor 16 constituting the second coil 21 and the fourth extraction electrode 28 connected to the fourth conductor 18 can be reduced, the first Thus, the stray capacitance in the coil 21 can be reduced, whereby the common mode impedance can be increased to the high frequency region. As described above, since the widths of the first extraction electrode 23 and the fourth extraction electrode 28 are wide, the stray capacitance with the portion facing them is very large. The effect of reducing stray capacitance by preventing the first extraction electrode 23 and the fourth extraction electrode 28 from overlapping the second conductor 14 and the third conductor 16 in a top view is great. .

  Further, when the second conductor 14 and the first extraction electrode 23 overlap in the top view, or when the third conductor 16 and the fourth extraction electrode 28 overlap in the top view, a short circuit failure In order to suppress the occurrence of this, it is necessary to increase the distance between the second conductor 14 and the first extraction electrode 23 and the distance between the third conductor 16 and the fourth extraction electrode 28. In this case, the compressibility of the insulating layer may be lowered so that the second conductor 14, the first extraction electrode 23, the third conductor 16, and the fourth extraction electrode 28 do not bite into the insulating layer. However, in this case, delamination due to insufficient bite occurs. On the other hand, as in the embodiment of the present invention, the first extraction electrode 23 and the fourth extraction electrode 28 do not overlap the second conductor 14 and the third conductor 16 in a top view. If so, the compressibility of the insulating layer can be increased so that the second conductor 14, the first lead electrode 23, the third conductor 16, and the fourth lead electrode 28 bite into the insulating layer. No delamination occurs. Further, the compressibility of the insulating layer can be easily increased by increasing the proportion of the solvent in the insulating layer.

  In the common mode noise filter according to the embodiment of the present invention, the portion of the second conductor 14 that is located in the vicinity of the first extraction electrode 23 and the third conductor 16 in the top view. Of these, the portion located in the vicinity of the fourth extraction electrode 28 in a top view is formed at a right angle as shown in FIG. 3, but this portion is formed in a C-plane shape as shown in FIG. Alternatively, it may be configured in a curved shape as shown in FIG.

  That is, in the configuration shown in FIG. 3, if the second conductor 14 and the third conductor 16 are displaced from the center when they are not overlapped in a top view, If the shape shown in FIG. 5 is used, the magnetic path length of the coils 20 and 21 does not change greatly because there is no need for this, so that the impedance of the common mode component is not changed, thereby suppressing short-circuit defects. be able to. In addition, the DC resistance value can be lowered.

  Here, FIGS. 4 and 5 show only the relationship between the third conductor 16 and the fourth conductor 18 in a top view for the sake of simplicity.

  In the above-described embodiment of the present invention, the first coil 20 and the second coil 21 are provided, but a plurality of the first coil 20 and the second coil 21 are provided. The provided array type may be used.

  The common mode noise filter according to the present invention has an effect of suppressing the occurrence of short-circuit defects, and is particularly useful in a small and stacked common mode noise filter used for various electronic devices. It is.

The disassembled perspective view of the common mode noise filter in one embodiment of this invention Perspective view of the common mode noise filter Top view of the main part of the common mode noise filter Top view of the main part showing another example of the common mode noise filter Top view of the main part showing still another example of the common mode noise filter Exploded perspective view of a conventional common mode noise filter Top view of the main part of the 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 23 1st extraction electrode 25 2nd extraction electrode 26 3rd extraction electrode 28 4th extraction electrode

Claims (2)

A plurality of insulating layers, first to fourth conductors provided on the plurality of insulating layers, and first to fourth extraction electrodes provided on one end of each of the first to fourth conductors The first conductor and the second conductor are connected, the third conductor and the fourth conductor are connected, and the shape of the second conductor and the third conductor is spiral. And the second conductor and the first extraction electrode are formed so as not to overlap each other when viewed from above, and the third conductor and the fourth extraction electrode are not overlapped when viewed from above. Common mode noise filter formed as follows. A portion of the second conductor located in the vicinity of the first extraction electrode in a top view and a portion of the third conductor located in the vicinity of the fourth extraction electrode in a top view are curved lines. The common mode noise filter according to claim 1, wherein the common mode noise filter is configured in a shape or a C-plane shape.

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