JP2005311100A - Noise filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise filter which can remove a noise in a wide frequency band. <P>SOLUTION: The noise filter includes a first conductor 12 provided on the upper surface of a first insulator layer 11, a first metal layer 14 provided on the upper surface of a second insulator layer 13 to be opposed to the first conductor 12, and a second metal layer 16 connected to the first conductor 12 and provided on the upper surface of a third insulator layer 15 to be opposed to the first metal layer 14. According to this configuration, since an electrostatic capacity can be obtained in a distributed constant between the first metal layer 14 and the second metal layer 16, and between the first conductor 12 and the first metal layer 14, the noise can be removed in the wide frequency band. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a noise filter widely used in electronic devices such as small digital devices, OA devices, and portable terminals.

  As shown in FIG. 4, a conventional noise filter of this type includes an inductor conductor formed by laminating a plurality of coil conductors 2 formed on a first insulating layer 1 made of a magnetic material such as ferrite or a dielectric. The capacitor conductor 4 formed on the second insulating layer 3 made of a magnetic material or a dielectric material is laminated in an independent state. With this configuration, the conventional noise filter has a configuration including an inductor portion made up of the first insulating layer 1 and the inductor conductor and a capacitor portion made up of the second insulating layer 3 and the capacitor conductor 4. .

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
Japanese Utility Model Publication No. 60-17895

  The conventional noise filter described above has a lumped-constant noise filter structure in which the inductor conductor and the capacitor conductor 4 are independently formed, so that only noise in the resonance frequency band between the inductor portion and the capacitor portion is removed. As a result, there is a problem that it is difficult to remove noise in a wide frequency band.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a noise filter that can remove noise in a wide frequency band.

  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 insulator layer and an upper surface of the second insulator layer so as to face the first conductor are provided. And a second metal layer connected to the first conductor and provided on the upper surface of the third insulator layer so as to face the first metal layer. Therefore, according to this configuration, the capacitance can be obtained in a distributed constant between the first conductor and the first metal layer, and between the first metal layer and the second metal layer. Therefore, there is an effect that noise can be removed in a wide frequency band.

  According to the second aspect of the present invention, the first conductor has a spiral shape. According to this configuration, since the inductance of the first conductor can be increased, noise is removed in a high frequency band. It has the effect that it can do.

  The invention according to claim 3 of the present invention is connected to the first metal layer between the lines of the first conductor, particularly along the first conductor, on the upper surface of the first insulator layer. A spiral second conductor is formed, and an inner conductor portion composed of the first conductor and the second conductor is provided. According to this configuration, the first conductor and the second conductor In the meantime, since the capacitance can be obtained in a distributed constant manner, there is an effect that noise can be removed in a wider frequency band.

  In the invention according to claim 4 of the present invention, in particular, another internal conductor portion is provided on the upper or lower portion of the internal conductor portion so that the first conductors and the second conductors are connected to each other. Thus, according to this configuration, since the capacitance between the first conductor and the second conductor can be obtained in a larger distributed constant, noise can be removed in a wider frequency band. It has a working effect.

  According to a fifth aspect of the present invention, in particular, the first and second metal layers are provided below the first conductor, and the first metal layer is disposed above the second metal layer. Therefore, according to this configuration, since there is no second metal layer between the first conductor and the first metal layer, the distance between the first conductor and the first metal layer is shortened. As a result, the capacitance between the first conductor and the first metal layer can be obtained in a larger distributed constant, so that noise can be removed in a wider frequency band. It has an effect.

  According to a sixth aspect of the present invention, in particular, the first and second metal layers are provided below the first conductor, and the second metal layer is disposed above the first metal layer. Therefore, according to this configuration, there is no first metal layer between the first conductor and the second metal layer, so that the distance between the first conductor and the second metal layer is shortened. As a result, the connection between the first conductor and the second metal layer can be more reliably performed.

  According to the seventh aspect of the present invention, in particular, another second metal layer is provided below the first metal layer, and further another first metal layer is provided below the other second metal layer. According to this configuration, two first conductors can be provided not in the lateral direction but in the stacking direction, so that the size and size can be reduced.

  According to the eighth aspect of the present invention, in particular, a plurality of first metal layers are provided on the same surface of the second insulator layer. According to this configuration, the upper and lower surfaces of the first metal layer are provided. Since the area where the insulator layers located in the contact area can be increased, it is possible to prevent peeling at the place where the first metal layer is formed.

  According to the ninth aspect of the present invention, in particular, a plurality of second metal layers are provided on the same surface of the third insulator layer. According to this configuration, the upper and lower surfaces of the second metal layer are provided. Since the area where the insulator layers located in the contact with each other can be increased, it is possible to prevent peeling at the place where the second metal layer is formed.

  As described above, the noise filter of the present invention is provided on the upper surface of the second insulator layer so as to face the first conductor, and the first conductor provided on the upper surface of the first insulator layer. A first metal layer, and a second metal layer connected to the first conductor and provided on the upper surface of the third insulator layer so as to face the first metal layer. Therefore, the electrostatic capacitance can be obtained in a distributed constant between the first conductor and the first metal layer, and between the first metal layer and the second metal layer. This provides an excellent effect that noise can be removed in the frequency band.

  FIG. 1 is an exploded perspective view showing a noise filter according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the noise filter.

  As shown in FIG. 1, the noise filter according to the embodiment of the present invention is configured so that the first conductor 12 provided on the upper surface of the first insulator layer 11 faces the first conductor 12. A first metal layer 14 provided on the top surface of the second insulator layer 13 and a third insulator layer connected to the first conductor 12 and facing the first metal layer 14 15 and a second metal layer 16 provided on the upper surface of 15.

In the above configuration, the first insulator layer 11 is formed in a sheet shape from a dielectric material based on BaTiO ₃ or TiO ₂ or a magnetic material such as ferrite based on Fe ₂ O _3. These two are provided and have insulating properties.

  Each of the first conductors 12 is formed in a spiral shape by printing or transferring a conductive material such as silver. One of the first conductors 12 is formed on the upper surface of each of the two first insulator layers 11. It is provided one by one. And the one end part 12a of the 1st conductor 12 provided in the upper surface of the 1st insulator layer 11 located below, and the 1st provided in the upper surface of the 1st insulator layer 11 located above One end portion 12a of the conductor 12 is connected via a via electrode 17a provided in the upper first insulator layer 11, and constitutes one inductor portion. The other end of the lower first conductor 12 and the other end of the upper first conductor 12 are exposed from the lower first insulator layer 11 and the upper first insulator layer 11, respectively. Thus, the first extraction electrode 12b and the second extraction electrode 12c are configured.

  The first conductor 12 is not necessarily limited to a spiral shape. However, since the inductance of the first conductor 12 can be increased by making it a spiral shape, noise is removed in a high frequency band. can do. In addition, since the inductance of the first conductor 12 can be changed by adjusting the shape, length, etc. of the first conductor 12, a frequency band in which noise can be removed is set in a wide range. It is something that can be done. In addition, the number of the first insulator layers 11 and the number of the first conductors 12 are not necessarily limited to two, but by providing two or three or more, the inductance can be increased. Therefore, noise can be removed in a wide frequency band.

  Further, each of the first insulator layers 11 has the first conductor 12 so that the second conductor 18 extends along the first conductor 12 on the same surface as the surface on which the first conductor 12 is provided. It is formed between the lines. The first and second conductors 12 and 18 arranged in this way constitute an internal conductor portion 19. Further, one end portion of the second conductor 18 provided on the upper surface of the first insulator layer 11 located below is exposed from the first insulator layer 11 located below and exposed to the third lead. The electrode 18a is configured.

  Here, the second conductor 18 is formed in a spiral shape by printing or transferring a conductive material such as silver, and is provided on the upper surface of the first insulator layer 11 located below. The other end 18b of the second conductor 18 thus formed and the other end 18b of the second conductor 18 provided on the upper surface of the first insulator layer 11 located above the first conductor 18 are located above. It is connected via a via electrode 17b provided on the insulator layer 11 to form one capacitor conductor. The second conductor 18 is not necessarily provided, but by providing the second conductor 18, a capacitor portion is formed by the first conductor 12 and the second conductor 18. Since the capacitance can be obtained in a distributed manner, noise can be removed in a wider frequency band.

One second insulator layer 13 is provided below the first insulator layer 11 located below, and a dielectric material based on BaTiO ₃ or TiO ₂ or the like, or Fe ₂ O ₃ as a base. The sheet is made of a magnetic material such as ferrite and has an insulating property.

  The first metal layer 14 is formed by printing or transferring a conductive material such as silver, and is opposed to at least the first conductor 12 with the first insulator layer 11 positioned below. In this manner, the second insulator layer 13 is provided on the upper surface. Further, the first metal layer 14 forms convex portions on both sides, and the convex portions are exposed from the second insulator layer 13 to constitute the fourth extraction electrode 14a. In addition, the first metal layer 14 is connected to the second conductor 18 that is a capacitor conductor through the fourth extraction electrode 14a and the third extraction electrode 18a.

  As described above, since the capacitor portion is formed between the first metal layer 14 and the first conductor 12 constituting the inductor portion so as to face each other, the first metal layer Capacitance can be obtained in a distributed constant between 14 and the first conductor 12.

  The first metal layer 14 is provided over substantially the entire surface excluding the peripheral portion of the second insulator layer 13, and according to this configuration, the area facing the first conductor 12 is increased. Therefore, the capacitance can be obtained in a larger distributed constant.

  Note that a plurality of the first metal layers 14 may be provided on the same surface of the second insulator layer 13, and in this case, the first metal layer 14 located on the upper and lower surfaces of the first metal layer 14. Since the area where the insulator layer 11 and the second insulator layer 13 are in contact with each other can be increased, it is possible to prevent the noise filter from being peeled off at the place where the first metal layer 14 is formed. In order to prevent this peeling, a through hole or a slit may be formed in the first metal layer 14.

The third insulator layer 15 is provided below the second insulator layer 13 and is made of a dielectric material based on BaTiO ₃ or TiO ₂ or a ferrite based on Fe ₂ O ₃ . The sheet is made of a magnetic material and has an insulating property.

  The second insulator layer 13 and the third insulator layer 15 may be provided in a plural number instead of one.

  The second metal layer 16 is formed by printing or transferring a conductive material such as silver, and the third metal layer 16 is formed so as to face the first metal layer 14 with the second insulator layer 13 interposed therebetween. Two insulator layers 15 are provided on the upper surface. Further, the two second metal layers 16 form convex portions at both ends, respectively, and the convex portions are exposed from the third insulator layer 15 to constitute the fifth lead metal 16a. ing. The second metal layer 16 is connected to the first conductor 12 which is an inductor conductor via the fifth lead electrode 16a and the first and second lead electrodes 12a and 12b.

  By arranging the second metal layer 16 and the first metal layer 14 so as to face each other as described above, a capacitor portion is also formed between the second metal layer 16 and the first metal layer 14. Capacitance can be obtained in a distributed manner with the metal layer 14.

  That is, the first conductor 12 constituting the inductor conductor and the second metal layer 16 connected to the first conductor 12 and the second conductor 18 and the second conductor 18 constituting the capacitor conductor are connected. In addition, since the capacitor portion is formed between the first metal layer 14 and the capacitor portion, the capacitance can be obtained in a distributed constant manner therebetween.

  In addition, since a plurality of the second metal layers 16 are provided on the same surface of the third insulator layer 15, the second insulator layer 13 and the second insulator layer 13 positioned on the upper and lower surfaces of the second metal layer 16 are provided. The area where the three insulator layers 15 come into contact with each other can be increased, whereby the noise filter can be prevented from peeling off at the place where the second metal layer 16 is formed. In order to prevent this peeling, a through hole or a slit may be formed in the second metal layer 16.

  In addition, the second metal layer 16 may be provided over almost the entire surface excluding the peripheral portion of the third insulator layer 15. In this case, the area facing the first metal layer 14. Therefore, the capacitance can be obtained in a larger distributed constant.

  Further, since the first metal layer 14 is disposed above the second metal layer 16, there is no second metal layer 16 between the first conductor 12 and the first metal layer 14. Thus, since the distance between the first conductor 12 and the first metal layer 14 can be shortened, the capacitance between the first conductor 12 and the first metal layer 14 is more largely distributed. It can be obtained in a constant manner.

  On the other hand, the first metal layer 14 may be disposed below the second metal layer 16, and in this case, the first metal layer is interposed between the first conductor 12 and the second metal layer 16. 14 does not exist, the distance between the first conductor 12 and the second metal layer 16 can be shortened, and thereby the connection between the first conductor 12 and the second metal layer 16 is more reliably performed. It is something that can be done.

  Further, a predetermined number of other insulator layers 20 are provided on the upper surface of the inner conductor portion 19 and the lower surface of the third insulator layer 15, respectively.

  The first conductor 12, the second conductor 18, the first insulator layer 11, the second insulator layer 13, the third insulator layer 15, the other insulator layer 20, and the first metal By laminating the layer 14 and the second metal layer 16 with the above-described configuration, a noise filter body 21 as shown in FIG. 2 is obtained.

  On both end faces of the noise filter main body 21 shown in FIG. 2, first and second external electrodes 22 and 23 serving as input / output terminals connected to the first and second lead electrodes 12b and 12c are provided. In addition, on both side surfaces of the noise filter main body 21, a third external electrode 24 serving as a ground terminal connected to the third extraction electrode 18a and the fourth extraction electrode 14a is provided.

  At this time, the first metal layer 14 and the second conductor 18 are electrically connected by connecting the fourth extraction electrode 14a and the third extraction electrode 18a via the third external electrode 24. The Note that the first metal layer 14 may be electrically connected to the second conductor 18 via a via electrode or the like instead of the third external electrode 24.

  Further, the fifth extraction electrode 16a and the first and second extraction electrodes 12b and 12c are connected via the first and second external electrodes 22 and 23, so that the second metal layer 16 and the first extraction electrode 12b and 12c are connected to each other. One conductor 12 is electrically connected. Note that the second metal layer 16 may be electrically connected to the first conductor 12 via a via electrode or the like instead of the first and second external electrodes 22 and 23.

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

  In FIG. 1 and FIG. 2, first, rectangular first to third insulator layers 11, 13, 15, and other insulators are made of a mixture of dielectric material and magnetic material powder and resin as raw materials. A predetermined number of layers 20 are produced. At this time, the first to third insulator layers 11, 13, 15 and the other insulator layers 20 are not immediately fired but are in a green sheet state. Further, two holes of the predetermined first insulator layer 11 are drilled by laser, punching or the like, and the holes are filled with silver to provide via electrodes 17a and 17b.

  Next, after the third insulator layer 15 is disposed on the upper surface of the other insulator layer 20, two second metal layers 16 are printed on both ends of the upper surface of the third insulator layer 15 by printing. Form.

  Next, the second insulator layer 13 is disposed on the upper surface of the second metal layer 16.

  Next, the first metal layer 14 is formed on the upper surface of the second insulator layer 13 by printing. The first metal layer 14 and the second metal layer 16 may not be formed by printing, but may be formed by other methods such as transfer, vapor deposition, plating, or disposing a metal plate.

  Next, the first insulator layer 11 is disposed on the upper surface of the first metal layer 14.

  Next, the first conductor 12 and the second conductor 18 are formed on the upper surface of the first insulator layer 11 by plating. At this time, the second conductor 18 is formed between the lines of the first conductor 12 along the first conductor 12.

  Next, another first insulator layer 11 provided with via electrodes 17a and 17b at two locations is arranged on the upper surfaces of the first and second conductors 12 and 18.

  At this time, the spiral central portions 12a of the first conductor 12 are connected to each other via the via electrode 17a, and the spiral central portions 18b of the second conductor 18 are connected to each other via the via electrode 17b. To do.

  Next, the first conductor 12 and the second conductor 18 are formed on the top surface of the other first insulator layer 11 by plating. At this time, the second conductor 18 is formed between the lines of the first conductor 12 along the first conductor 12.

  The first conductor 12 and the second conductor 18 are formed by forming a conductor having a predetermined pattern shape on a separately prepared base plate (not shown) by plating, and then forming the conductor in a green sheet state. It is formed by transferring to one insulator layer 11. Further, the first conductor 12 and the second conductor 18 may be formed by other methods such as printing and vapor deposition instead of being formed by plating.

  Next, another insulator layer 20 is formed on the upper surfaces of the upper first and second conductors 12 and 18 to obtain a laminate.

  In the manufacturing process, in order to improve manufacturing efficiency, the plurality of first conductors 12, the second conductor 18, the first insulator layer 11, the second insulator layer 13, and the third conductor After laminating the insulator layer 15, the other insulator layer 20, the first metal layer 14, and the second metal layer 16 with the above-described configuration, a plurality of laminates are obtained simultaneously by cutting into individual pieces. You may do it.

  Next, the laminate is fired at a predetermined temperature and time.

  Next, first and second external electrodes 22 and 23 are formed on both end faces of the laminate by printing silver so as to be connected to the first and second extraction electrodes 12a and 12b, and The third external electrode 24 is formed by printing silver so as to be connected to the third extraction electrode 18a on both side surfaces.

  Finally, a nickel plating layer is formed on the surfaces of the first to third external electrodes 22 to 24 by plating, and a low melting point metal plating layer such as tin or solder is formed on the surface of the nickel plating layer by plating.

  In the above-described embodiment of the present invention, the first conductor 12 provided on the upper surface of the first insulator layer 11 and the second insulator layer 13 so as to face the first conductor 12. The first metal layer 14 provided on the upper surface of the first insulating layer 15 is connected to the first conductor 12 and is provided on the upper surface of the third insulator layer 15 so as to face the first metal layer 14. Since the second metal layer 16 is provided, the capacitance between the first conductor 12 and the first metal layer 14, and between the first metal layer 14 and the second metal layer 16. Can be obtained in a distributed manner, and as a result, an excellent effect that noise can be removed in a wide frequency band can be obtained.

  Further, in the internal conductor portion 19, since the spiral second conductor 18 is formed between the lines of the first conductor 12 along the first conductor 12, the first conductor 12 and the second conductor 18 are formed. The capacitance between the conductor 18 and the conductor 18 can be obtained in a larger distributed constant, thereby removing noise in a wider frequency band.

  In the noise filter according to the embodiment of the present invention, two internal conductor portions 19 are provided. However, other numbers may be used. On the other hand, the internal conductor portion 19 is formed without providing the second conductor 18. You don't have to. However, it is preferable that the number of the inner conductor portions 19 is larger because the capacitance can be further increased.

  In addition, the second metal layer 16, the first metal layer 14, and the inner conductor portion 19 are arranged in this order from the bottom, but conversely the second metal layer 16, the first metal layer 16 from the top The metal layer 14 and the inner conductor portion 19 may be disposed in this order.

  In addition, although the first metal layer 14, the second metal layer 16, the first conductor 12, and the second conductor 18 are arranged in the vertical direction, one noise filter is configured. A plurality of them may be provided and arranged in the horizontal direction to form an array type.

  In particular, as an array type, as shown in FIG. 3, the first conductor 12, the second metal layer 16, the first metal layer 14, the other second metal layer 16, and the other first are arranged from the top. If the first conductors 12 are provided in this order, two first conductors 12 can be provided not in the horizontal direction but in the stacking direction, so that the size can be reduced. At this time, an internal conductor portion 19 may be provided instead of the first conductor 12.

  The noise filter according to the present invention can remove noise in a wide frequency band, and is useful for electronic devices that require noise countermeasures such as mobile phones and information devices.

The disassembled perspective view of the noise filter in one embodiment of this invention Perspective view of the noise filter An exploded perspective view showing another example of the noise filter An exploded perspective view showing a conventional noise filter

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st insulator layer 12 1st conductor 13 2nd insulator layer 14 1st metal layer 15 3rd insulator layer 16 2nd metal layer 18 2nd conductor 19 Inner conductor part 22 1st External electrode 23 Second external electrode 24 Third external electrode

Claims (9)

A first conductor provided on an upper surface of the first insulator layer; a first metal layer provided on an upper surface of the second insulator layer so as to face the first conductor; A second metal layer provided on the top surface of the third insulator layer so as to be opposed to the first metal layer, and a first and a second metal layer connected to the first conductor. A noise filter comprising two external electrodes and a third external electrode connected to the first metal layer. The noise filter according to claim 1, wherein the first conductor is spiral. On the upper surface of the first insulator layer, a spiral second conductor connected to the first metal layer is formed between the lines of the first conductor along the first conductor, and the first conductor layer The noise filter according to claim 2, wherein an inner conductor portion composed of one conductor and a second conductor is provided. The noise filter according to claim 3, wherein another internal conductor portion is provided on the upper or lower portion of the internal conductor portion so that the first conductors and the second conductors are connected to each other. The noise filter according to claim 1, wherein the first and second metal layers are provided below the first conductor, and the first metal layer is disposed above the second metal layer. The noise filter according to claim 1, wherein the first and second metal layers are provided below the first conductor, and the first metal layer is disposed above the second metal layer. The noise filter according to claim 6, wherein another second metal layer is provided below the first metal layer, and another first conductor is further provided below the other second metal layer. The noise filter according to claim 1, wherein a plurality of first metal layers are provided on the same surface of the second insulator layer. The noise filter according to claim 1, wherein a plurality of second metal layers are provided on the same surface of the third insulator layer.

Images