JP6029814B2 - Chip inductor - Google Patents

Description

  The present invention relates to a chip inductor for surface mounting or built-in of a wiring board.

  In recent years, chip inductors are frequently used as high-frequency noise countermeasure parts for high-density mounting circuit boards. Conventionally, chip inductors are laminated by firing or laminating a plurality of electrically insulating magnetic layers and a plurality of coil-forming inner conductors alternately by printing or laminating so that the ends of the inner conductors are connected to each other. Thereafter, the end face electrode is formed by applying and baking a conductive paste on the end face around the sintered body.

  The chip inductor thus obtained is disposed at a position intersecting the inner conductor constituting the coil embedded in the magnetic layer and the surface of the magnetic layer including the inner conductor, and one end of the inner conductor and A pair of electrodes electrically connected at the other end. This chip inductor is useful as a surface-mounted chip component that can be automatically mounted because it is small, has a large inductance, and has a rectangular parallelepiped shape (Patent Document 1).

  On the other hand, with the trend toward higher performance and downsizing of electronic devices in recent years, higher density and higher functionality of circuit components are further demanded. From this point of view, a module equipped with a chip inductor is required to cope with higher density and higher functionality.

  As an example of the above module, a module in which a chip inductor is mounted on the surface of a wiring board composed of at least a pair of wiring layers and an insulating layer disposed between the pair of wiring layers, or a module in which a chip inductor is built in the wiring board Can be mentioned.

  However, in the former case, the distance from the adjacent circuit components and other electronic components is close due to the above-described demand for higher density, so that the high frequency current caused by the leakage magnetic flux from the chip inductor is In other words, the circuit component or the like does not function well.

  In the latter case, since the distance between the built-in chip inductor and the wiring layer is close, for example, a high-frequency current caused by a leakage magnetic flux from the chip inductor is generated in the wiring layer functioning as a ground layer or a power supply layer. As a result, the potential of other circuit components mounted on the wiring board fluctuates, or stable power supply cannot be performed and the circuit components do not function well. there were.

JP-A-5-55045

  The present invention reduces the leakage magnetic flux of the surface mounting or built-in chip inductor of the wiring board, reduces the influence of noise caused by the leakage magnetic flux on other circuit components and electronic components mounted on the wiring board, The object is to maintain the operation of these circuit components and electronic components satisfactorily.

In order to achieve the above object, the present invention provides:
A chip inductor for surface mounting or built-in wiring board,
An inner conductor constituting a coil embedded in the magnetic layer;
A pair of electrodes disposed at a position intersecting the surface including the inner conductor of the magnetic layer, and one end and the other end of the inner conductor are electrically connected;
An electromagnetic wave noise absorbing layer disposed on a plane parallel to the plane including the inner conductor of the magnetic layer ,
The electromagnetic noise absorbing layer relates to a chip inductor, wherein magnetic particles are dispersed in a resin .

  A pair of an inner conductor constituting a coil embedded in the magnetic layer and a position where the inner layer of the magnetic layer intersects the surface including the inner conductor, and one end and the other end of the inner conductor are electrically connected. In the conventional chip inductor having a plurality of electrodes, when a current is passed through the coil of the chip inductor and the chip inductor is driven, the current flows through the coil, whereby the center of the coil, that is, the inner conductor constituting the coil is A magnetic field is formed in a direction perpendicular to the containing plane. When the thickness of the magnetic layer constituting the chip inductor is small, the magnetic field leaks from the magnetic layer, that is, the chip inductor, to form a so-called leakage magnetic flux.

  However, according to the present invention, in the chip inductor having the conventional configuration described above, the electromagnetic wave noise absorbing layer is disposed on the surface of the magnetic layer parallel to the surface including the internal conductor. Therefore, as described above, even when the thickness of the magnetic layer constituting the chip inductor is small, the magnetic field formed in the direction perpendicular to the center of the coil, that is, the surface including the inner conductor, absorbs electromagnetic noise. It is absorbed in the layer and converted to thermal energy.

  As a result, since the magnetic field does not leak to the outside from the magnetic layer, that is, the chip inductor, generation of leakage magnetic flux can be prevented. For this reason, in a module in which a chip inductor is mounted on the surface of a wiring board composed of at least a pair of wiring layers and an insulating layer disposed between the pair of wiring layers, the chip inductors are adjacent to each other with a demand for higher density. Even if the distance to the circuit components and other electronic components to be used is close, no leakage magnetic flux is generated from the chip inductor, so that high-frequency current caused by the leakage magnetic flux is superimposed on the circuit components as noise. There is no. As a result, it is possible to avoid the problem that the circuit components do not function well.

  In addition, in a module in which a chip inductor is built in a wiring board, even if the distance between the built-in chip inductor and the wiring layer is close, for example, the leakage flux from the chip inductor is applied to the wiring layer functioning as a ground layer or a power supply layer. The resulting high frequency current is not superimposed as noise. As a result, it is possible to avoid the problem that the potential of other circuit components mounted on the wiring board fluctuates or the circuit components do not function well without being able to supply stable power. Can do.

  In an example of the present invention, a conductive layer can be formed on the electromagnetic wave noise absorbing layer. In this case, since the conductive layer functions as a shield layer against the magnetic field generated as described above, it is possible to more effectively suppress the magnetic field from leaking to the outside of the chip inductor as a leakage magnetic flux.

  In addition, as described above, the “electromagnetic wave noise absorbing layer” in the present invention prevents external leakage of leakage magnetic flux by absorbing a magnetic field and converting it into thermal energy, and the “conductive layer” is simply a magnetic field. Is shielded (reflected inward) to prevent external leakage of the leakage magnetic flux. Therefore, both have the same effect of preventing the leakage of the magnetic flux leakage, but the functions for producing the effect are different from each other.

  As described above, according to the present invention, the leakage magnetic flux of the surface mounting or built-in chip inductor of the wiring board is reduced, and the influence of noise caused by the leakage magnetic flux on other circuit components and electronic components mounted on the wiring board is reduced. The operation of these circuit components and electronic components can be satisfactorily maintained.

It is sectional drawing which shows schematic structure of the chip inductor of 1st Embodiment. FIG. 2 is a top plan view of the chip inductor shown in FIG. 1. It is sectional drawing which shows the module which mounted the chip inductor shown in FIG.1 and FIG.2 on the surface of the wiring board. FIG. 3 is a view showing a modification of the chip inductor 10 shown in FIGS. 1 and 2. It is sectional drawing which shows the module which incorporated the chip inductor shown in FIG.1 and FIG.2 in the wiring board in 2nd Embodiment. It is sectional drawing which shows schematic structure of the chip inductor of 3rd Embodiment.

  Hereinafter, other features and advantages of the present invention will be described based on embodiments for carrying out the invention.

(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of the chip inductor of the present embodiment, and FIG. 2 is a top plan view of the chip inductor shown in FIG. FIG. 3 is a cross-sectional view showing a module in which the chip inductor shown in FIGS. 1 and 2 is mounted on the surface of the wiring board.

  As shown in FIGS. 1 and 2, the chip inductor 10 of the present embodiment includes a non-conductive magnetic layer 11 and a coil 12 embedded in the magnetic layer 11. The coil 12 has a configuration in which four L-shaped inner conductors 121, 122, 123, and 124 are sequentially stacked from above on a conductor shaft 125 extending in the vertical direction. A part of the magnetic layer 11 is interposed between adjacent internal conductors, and the internal conductors are electrically insulated from each other.

  The inner conductors 121, 122, 123, and 124 may have a circular or rectangular winding structure with the conductor shaft 125 as a base point, instead of being configured as an L shape.

  Further, the position of the surface S1 including the inner conductor 121, the surface S2 including the inner conductor 122, the surface S3 including the inner conductor 123, and the surface S4 including the inner conductor 124 of the magnetic layer 11, that is, the magnetic layer 11. A pair of electrodes 13 and 13 are disposed on the side surfaces of the inner conductor 121, and the end of the inner conductor 121 located in the uppermost layer and the end of the inner conductor 124 located in the lowermost layer are electrically connected to the electrodes 13 and 13. The internal conductors 121, 122, 123, and 124 can be energized via the conductor shaft 125 by being connected. Therefore, the coil 12 is energized, and the chip inductor 10 can perform its function.

  Further, the surface S1 of the magnetic layer 11 including the inner conductor 121, the surface S2 including the inner conductor 122, the surface S3 including the inner conductor 123 and the surface S4 including the inner conductor 124, that is, the magnetic layer. A pair of electromagnetic wave noise absorption layers 14 and 14 are disposed on the upper surface and the lower surface of 11.

  In the present embodiment, the electromagnetic wave noise absorbing layers 14 and 14 are disposed on both the upper surface and the lower surface of the magnetic layer 11, but as long as the object of the present invention can be achieved, The electromagnetic wave noise absorbing layer 14 may be provided only on the surface. The electromagnetic wave noise absorbing layers 14 and 14 are formed so as to cover at least the internal space defined by the internal conductors 121, 122, 123 and 124, that is, the magnetic field forming region, on the upper and lower surfaces of the magnetic layer 11.

  The magnetic layer 11 can be made of, for example, ferrite or magnetite that is stable in the atmosphere. The coil 12, that is, the internal conductors 121, 122, 123, and 124 can be made of gold, silver, copper, aluminum, or the like, which is a good electrical conductor. The electrode 13 can also be composed of a good electrical conductor such as gold, silver, copper, aluminum or the like.

  The electromagnetic wave noise absorbing layer 14 may be made of any material as long as it performs its function as described below. However, in order to exhibit its function more effectively, the magnetic particles are dispersed in the resin. It is preferable that they are formed. In this case, the magnetic particles are preferably at least one selected from the group consisting of ferrite, carbonyl iron, molybdenum permalloy, and sendust.

  The resin constituting the electromagnetic wave noise absorbing layer 14 is preferably a so-called thermosetting resin that does not soften due to heat generation of the coil 12 or the like. Among such thermosetting resins, at least epoxy resin and polyimide are used. Preferably there is. This is because the insulating layer of the wiring board on which the chip inductor is mounted is mainly composed of epoxy resin or polyimide, so that it is not necessary to separately prepare a resin that constitutes the electromagnetic wave noise absorbing layer 14, and the manufacturing cost of the chip inductor is further reduced. Since the manufacturing cost of the module obtained by mounting the chip inductor on the wiring board can be reduced, it is possible to maintain the reliability by using the same kind of material. Moreover, since it is not a special material, the increase in the manufacturing cost of a chip inductor can be suppressed.

  On the other hand, conventionally, it is necessary to increase the total number of wiring boards to be mounted and insert a shield layer, resulting in an increase in the cost of the wiring board. In the present embodiment, the addition of such a shield layer is not necessary, and the manufacturing cost of the module obtained by mounting the chip inductor on the wiring board can be reduced. Furthermore, since the total number of wiring boards is reduced, the wiring board can be made thinner.

  In addition to the materials described above, silicone resin, polyamide resin, phenol resin, PET resin, and the like can also be mentioned. In order to perform the function as the electromagnetic wave noise absorbing layer 14 more effectively, the resin as described above is used. It is preferable that the magnetic particles are dispersed therein.

  The chip inductor 10 shown in FIGS. 1 and 2 includes a plurality of electrically insulating magnetic layers and a plurality of inner conductors 121, 122, 123, and 124 of the coil 12, as in the prior art. After the layers are alternately laminated by printing or laminating so that the portions are connected to each other at the conductor shaft 125 and fired and integrated to form the magnetic layer 11, a conductive paste is applied and baked on the side surface of the magnetic layer 11 to form the electrodes 13, 13 can be produced. In addition, the electromagnetic wave noise absorbing layers 14 and 14 are formed by using the resin constituting the electromagnetic wave noise absorbing layers 14 and 14 as a binder on the upper surface and the lower surface of the magnetic layer 11 obtained as described above, and the magnetic material is contained in the binder. It can be formed by applying and baking a paste obtained by dispersing particles.

  Next, a module obtained by mounting the chip inductor 10 shown in FIGS. 1 and 2 on the surface of the wiring board will be described with reference to FIG. In FIG. 3, the configuration of the chip inductor 10 is illustrated in a simplified manner.

  The wiring board 20 shown in FIG. 3 has a first wiring layer 21 and a second wiring layer 22, and a first insulating layer 31 is disposed between them. Further, the third wiring layer 23 and the fourth wiring are provided between the first wiring layer 21 and the second wiring layer 22 so as to be electrically insulated by a part of the first insulating layer 31. A layer 24 is provided. Further, a fifth wiring layer 25 is disposed outside (downward) the first wiring layer 21 via a second insulating layer 32, and the second wiring layer 22 is outside ( A sixth insulating layer 26 is disposed above the third insulating layer 33 via the third insulating layer 33.

  The fifth wiring layer 25 and the sixth wiring layer 26 are configured to be partially exposed to the outside through the resist layers 51 and 52.

  The first wiring layer 21 and the third wiring layer 23 are electrically connected by a first interlayer connector 41, and the third wiring layer 23 and the fourth wiring layer 24 are a second interlayer connector. The fourth wiring layer 24 and the second wiring layer 22 are electrically connected by a third interlayer connector 43. The first wiring layer 21 and the fifth wiring layer 25 are electrically connected by the fourth interlayer connector 44, and the second wiring layer 22 and the sixth wiring layer 26 are the fifth interlayer. The connection body 45 is electrically connected. Therefore, the wiring board 20 of this embodiment constitutes a so-called multilayer wiring board.

  The first wiring layer 21 to the sixth wiring layer 26 may be configured as a wiring pattern by performing predetermined patterning as necessary, or may be configured as a solid pattern.

  As is clear from FIG. 3, the chip inductor 10 is electrically connected to the surface of the wiring substrate 20, specifically, the sixth wiring layer 26 located on the outermost layer via the solder 10A. Has been implemented. In an actual module, electronic components such as various active components are mounted on the surface of the wiring board 20 in addition to the chip inductor 10.

  In the module shown in FIG. 3, when a current is passed through the coil 12 of the chip inductor 10 to drive the chip inductor 10, the current flows through the coil 12, whereby the center of the coil 12, that is, the inner conductor 121 that constitutes the coil 12. , 122, 123 and 124, a magnetic field is formed in a direction perpendicular to the surfaces S1, S2, S3 and S4. In the conventional chip inductor in which the electromagnetic wave noise absorbing layers 14 and 14 are not formed, when the magnetic layer 11 has a small thickness, the magnetic field leaks to the outside from the magnetic layer 11, that is, the chip inductor, A so-called leakage magnetic flux is formed.

  However, in the chip inductor 10 of the present embodiment, the surface of the magnetic layer 11 parallel to the surfaces S1, S2, S3, and S4 including the inner conductors 121, 122, 123, and 124, that is, the upper surface of the magnetic layer 11 and Electromagnetic wave noise absorbing layers 14 and 14 are disposed on the lower surface. Therefore, as described above, even when the thickness of the magnetic layer 11 constituting the chip inductor 10 is small, the center of the coil 12, that is, the surfaces S1, S2, including the internal conductors 121, 122, 123, and 124, are included. The magnetic field formed in the direction perpendicular to S3 and S4 is absorbed by the electromagnetic wave noise absorbing layers 14 and 14 and converted into thermal energy.

  As a result, the magnetic field does not leak to the outside from the magnetic layer 11, that is, the chip inductor 10, so that generation of leakage magnetic flux can be prevented. For this reason, even when the chip inductor 10 is mounted on the surface of the wiring board 20, the chip inductor 10 may be disposed even if the distance from adjacent circuit components (not shown) or other electronic components is close due to the demand for higher density. As a result, no leakage magnetic flux is generated, so that the high-frequency current caused by the leakage magnetic flux is not superimposed on the circuit component or the like as noise. As a result, it is possible to avoid the problem that the circuit components do not function well.

  FIG. 4 shows a modification of the chip inductor 10 shown in FIGS. In the chip inductor 10 shown in FIGS. 1 and 2, the coil 12 is formed by sequentially laminating the four L-shaped inner conductors 121, 122, 123, and 124. However, as shown in FIG. Even in the case of the chip inductor 10 ′ having the meander-shaped coil 12 ′, at least the inner region of the coil 12 ′, that is, the magnetic field forming region is covered on the upper and lower surfaces of the magnetic layer 11 as described above. By forming the electromagnetic wave noise absorbing layers 14, 14, the same effect as described above can be obtained.

(Second Embodiment)
FIG. 5 is a cross-sectional view showing a module in which the chip inductor shown in FIGS. 1 and 2 is built in a wiring board. In FIG. 5, the configuration of the chip inductor 10 is illustrated in a simplified manner. Moreover, the same code | symbol is used with respect to the component similar to or the same as the component shown in FIGS. Further, since the configuration and characteristics of the chip inductor 10 have been described in detail with reference to FIGS. 1 and 2, the description thereof will be omitted in this embodiment.

  A wiring board 20 shown in FIG. 5 has a first wiring layer 21 and a second wiring layer 22, and a first insulating layer 31 is disposed between them. The chip inductor 10 is embedded in the first insulating layer 31 so as to be electrically connected to the first wiring layer 21. The chip inductor 10 is electrically and mechanically connected to the first wiring layer 21 by solder 10A.

  Further, outside the chip inductor 10, the first wiring layer 21 and the second wiring layer 22 are electrically insulated by a part of the first insulating layer 31, so that the third wiring layer 22 and the second wiring layer 22 are electrically insulated. A wiring layer 23 and a fourth wiring layer 24 are provided. Further, a fifth wiring layer 25 is disposed outside (downward) the first wiring layer 11 via a second insulating layer 32, and outside the second wiring layer 22 ( A sixth insulating layer 26 is disposed above the third insulating layer 33 via the third insulating layer 33.

  The fifth wiring layer 25 and the sixth wiring layer 26 are configured to be partially exposed to the outside through the resist layers 51 and 52.

  The first wiring layer 21 and the third wiring layer 23 are electrically connected by a first interlayer connector 41, and the third wiring layer 23 and the fourth wiring layer 24 are a second interlayer connector. The fourth wiring layer 24 and the second wiring layer 22 are electrically connected by a third interlayer connector 43. The first wiring layer 21 and the fifth wiring layer 25 are electrically connected by the fourth interlayer connector 44, and the second wiring layer 22 and the sixth wiring layer 26 are the fifth interlayer. The connection body 45 is electrically connected. Therefore, the wiring board 20 of this embodiment constitutes a so-called multilayer wiring board.

  The first wiring layer 21 to the sixth wiring layer 26 may be configured as a wiring pattern by performing predetermined patterning as necessary, or may be configured as a solid pattern.

  As is clear from FIG. 5, the chip inductor 10 is built in the wiring board 20 and mounted on the first wiring layer 21. In an actual module, electronic components such as various active components are mounted on the surface of the wiring board 20. Moreover, electronic components are also mounted in the wiring board 20 as necessary.

  In the module shown in FIG. 5, when a current is passed through the coil 12 of the chip inductor 10 to drive the chip inductor 10, the current flows through the coil 12, whereby the center of the coil 12, that is, the inner conductor 121 that constitutes the coil 12. , 122, 123 and 124, a magnetic field is formed in a direction perpendicular to the surfaces S1, S2, S3 and S4. In the conventional chip inductor in which the electromagnetic wave noise absorbing layers 14 and 14 are not formed, when the magnetic layer 11 has a small thickness, the magnetic field leaks to the outside from the magnetic layer 11, that is, the chip inductor, A so-called leakage magnetic flux is formed.

  However, in the chip inductor 10 of the present embodiment, the surface of the magnetic layer 11 parallel to the surfaces S1, S2, S3, and S4 including the inner conductors 121, 122, 123, and 124, that is, the upper surface of the magnetic layer 11 and Electromagnetic wave noise absorbing layers 14 and 14 are disposed on the lower surface. Therefore, as described above, even when the thickness of the magnetic layer 11 constituting the chip inductor 10 is small, the center of the coil 12, that is, the surfaces S1, S2, including the internal conductors 121, 122, 123, and 124, are included. The magnetic field formed in the direction perpendicular to S3 and S4 is absorbed by the electromagnetic wave noise absorbing layers 14 and 14 and converted into thermal energy.

  As a result, the magnetic field does not leak to the outside from the magnetic layer 11, that is, the chip inductor 10. Therefore, even when the distance between the chip inductor 10 and the second wiring layer 12 is close, for example, The high frequency current resulting from the leakage magnetic flux from the chip inductor 10 is not superimposed on the layer 12 as noise. Therefore, even when the second wiring layer 22 functions as a ground layer or a power supply layer, the high-frequency current caused by the leakage magnetic flux from the chip inductor 10 is not superimposed as noise. As a result, it is possible to avoid the problem that the potential of other circuit components mounted on the wiring board 20 fluctuates or the circuit components do not function satisfactorily because stable power supply cannot be performed. be able to.

  Similar effects can be obtained when the chip inductor 10 'shown in FIG. 4 is used instead of the chip inductor 10 shown in FIGS.

(Third embodiment)
FIG. 6 is a cross-sectional view showing a schematic configuration of the chip inductor of the present embodiment. In addition, the same code | symbol is used about the component similar to or the same as the component shown in FIGS.

  As shown in FIG. 6, the chip inductor 60 of the present embodiment includes a conductive layer 65, by applying and baking a conductive paste on the electromagnetic wave noise absorbing layers 14, 14 of the chip inductor 10 shown in FIGS. 1 and 2. 65 is formed.

  Therefore, as shown in FIG. 3, even when the thickness of the magnetic layer 11 constituting the chip inductor 60 is small when the chip inductor 60 is mounted on the surface of the wiring board 20, the center of the coil 12, That is, the magnetic field formed in the direction perpendicular to the surfaces S1, S2, S3, and S4 including the inner conductors 121, 122, 123, and 124 is absorbed by the electromagnetic wave noise absorbing layers 14 and 14 and converted into thermal energy. . Furthermore, since the conductive layers 65 and 65 function as a shield layer against the magnetic field generated as described above, it is possible to more effectively suppress the magnetic field from leaking outside the chip inductor 60 as a leakage magnetic flux.

  As a result, the magnetic field does not leak to the outside from the magnetic layer 11, that is, the chip inductor 10, so that generation of leakage magnetic flux can be more effectively prevented. For this reason, even when the chip inductor 60 is mounted on the surface of the wiring board 20, the chip inductor 60 can be used even if the distance from adjacent circuit components (not shown) or other electronic components is close due to the demand for higher density. As a result, no leakage magnetic flux is generated, so that the high-frequency current caused by the leakage magnetic flux is not superimposed on the circuit component or the like as noise. As a result, it is possible to avoid the problem that the circuit components do not function well.

  Further, as shown in FIG. 5, when the chip inductor 60 is built in the wiring board 20 and the thickness of the magnetic layer 11 constituting the chip inductor 60 is small, the center of the coil 12, that is, the inside The magnetic field formed in the direction perpendicular to the surfaces S1, S2, S3, and S4 including the conductors 121, 122, 123, and 124 is absorbed by the electromagnetic wave noise absorbing layers 14 and 14 and converted into thermal energy. Furthermore, since the conductive layers 65 and 65 function as a shield layer against the magnetic field generated as described above, it is possible to more effectively suppress the magnetic field from leaking outside the chip inductor 60 as a leakage magnetic flux.

  As a result, since the magnetic field does not leak to the outside from the magnetic layer 11, that is, the chip inductor 60, even when the distance between the chip inductor 60 and the second wiring layer 12 is close, for example, the second wiring The high frequency current caused by the leakage magnetic flux from the chip inductor 60 is not superimposed on the layer 12 as noise.

  Therefore, even when the second wiring layer 22 functions as a ground layer or a power supply layer, the high-frequency current caused by the leakage magnetic flux from the chip inductor 60 is not superimposed as noise. As a result, it is possible to avoid the problem that the potential of other circuit components mounted on the wiring board 20 fluctuates or the circuit components do not function satisfactorily because stable power supply cannot be performed. be able to.

  In the present embodiment, the case where the conductive layers 65 and 65 are provided for the chip inductor 10 shown in FIGS. 1 and 2 has been described. However, the conductive layers 65 and 65 are provided for the chip inductor 10 ′ shown in FIG. Even when it is provided, the same effect can be obtained.

  Further, the conductive layers 65 and 65 can be made of a metal such as copper, nickel, gold, and silver. Therefore, the conductive paste described above can be formed by dispersing such metal particles in a binder.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

  For example, in the above-described embodiment, the wiring board 20 is configured as a multilayer wiring board having six wiring layers, but the number of wiring layers can be any number as necessary.

  In addition, the wiring board 20 does not necessarily have a multilayer wiring board configuration, and includes the first wiring layer 21 and the second wiring layer 22, and the first insulating layer 31 disposed between these wiring layers. A single-layer wiring board can also be obtained.

10, 10 ', 60 Chip inductor 11 Magnetic layer 12, 12' Coil 121, 122, 123, 124 Inner conductor 125 Conductor axis
DESCRIPTION OF SYMBOLS 13 Electrode 14 Electromagnetic wave noise absorption layer 20 Wiring board 21 1st wiring layer 22 2nd wiring layer 23 3rd wiring layer 24 4th wiring layer 25 5th wiring layer 26 6th wiring layer 31 1st Insulating layer 32 2nd insulating layer 33 3rd insulating layer 41 1st interlayer connection body 42 2nd interlayer connection body 43 3rd interlayer connection body 44 4th interlayer connection body 45 5th interlayer connection body 65 Conductive layer

Claims (6)

A chip inductor for surface mounting or built-in wiring board,
An inner conductor constituting a coil embedded in the magnetic layer;
A pair of electrodes disposed at a position intersecting the surface including the inner conductor of the magnetic layer, and one end and the other end of the inner conductor are electrically connected;
An electromagnetic wave noise absorbing layer disposed on a plane parallel to the plane including the inner conductor of the magnetic layer ,
The chip inductor, wherein the electromagnetic wave noise absorbing layer is formed by dispersing magnetic particles in a resin .   2. The chip inductor according to claim 1, wherein the electromagnetic wave noise absorbing layer is disposed on two surfaces of the magnetic layer parallel to a surface including the inner conductor. 3. The chip inductor according to claim 1, wherein the magnetic particles are made of at least one selected from the group consisting of ferrite, carbonyl iron, molybdenum permalloy, and sendust. The chip inductor according to claim 3 , wherein the resin is at least one of an epoxy resin and a polyimide. Wherein characterized in that it comprises a conductive layer formed on the electromagnetic noise absorbing layer, a chip inductor according to any one of claims 1-4. The chip inductor according to claim 5 , wherein the conductive layer is made of a conductive paste.

Images