JP6812886B2 - High frequency electronic components - Google Patents

Description

The present invention relates to high frequency electronic components including composite magnetic materials.

As the demand for miniaturization, thinning, or cost reduction of wireless communication equipment increases, the demand for miniaturization, thinning, or cost reduction of high-frequency electronic components mounted on these equipment is also increasing.

In recent years, for example, the 700 MHz band megahertz band or the 2.4 GHz band gigahertz band is used in mobile phones, and the frequency band used by high-frequency electronic components mounted on wireless communication devices such as mobile phones or wireless LAN communication devices has changed. , From the megahertz band to the gigahertz band. Examples of high-frequency electronic components used in such a megahertz band include inductors including coils, antennas for wireless communication devices including inductors, and filters for high-frequency noise countermeasures including inductors and capacitors, and these high-frequency electronic components However, there is an increasing demand for miniaturization, thinning, or cost reduction.

In particular, a plurality of these high-frequency electronic components may be housed in a narrow space inside a wireless communication device, and have high performance such as high inductance, low insertion loss, high capacitance, or high electromagnetic shielding performance. High frequency electronic components are needed.

However, for example, when a high-frequency electronic component including an inductor is made smaller and shorter, the diameter of the coil must be reduced, and the Q value and the inductance value are lowered, which makes it difficult to improve the performance of the high-frequency electronic component. Therefore, for these high-frequency electronic components, it is necessary to use a magnetic material having high magnetic permeability and low magnetic loss as the magnetic core material of the coil.

In Patent Document 1, a magnetic oxide having hexagonal ferrite as a main phase is dispersed and composited in a resin as a composite magnetic material having high magnetic permeability and low magnetic loss in a high frequency region from the megahertz band to the gigahertz band. Composite magnetic materials are described. Since the composite magnetic material of Patent Document 1 contains a magnetic oxide having high electrical resistance, eddy current loss can be reduced. Therefore, the magnetic loss coefficient tan δμ at 2 GHz is as small as 0.01, and the magnetic loss coefficient tan δμ in the gigahertz band can be reduced. However, the real part μ'of the complex magnetic permeability at 2 GHz is as small as 1.4, and the real part μ'of the complex magnetic permeability in the gigahertz band cannot be increased. That is, the composite magnetic material described in Patent Document 1 cannot achieve both high magnetic permeability and low magnetic loss.

Further, Patent Document 2 describes a magnetic composite material in which needle-shaped magnetic metal particles having an aspect ratio (major axis length / minor axis length) of 1.5 to 20 are dispersed in a dielectric material. .. In the magnetic composite material of Patent Document 2, the magnetic permeability μ'is as small as 1.37 in the sample having a loss tangent tan δ as small as 0.014 at 3 GHz, and the magnetic permeability μ'in the gigahertz band cannot be increased. On the other hand, in the sample having a large magnetic permeability μ'of 1.98, the loss tangent tan δ is as large as 0.096, and the loss tangent tan δ in the gigahertz band cannot be reduced. That is, the magnetic composite material described in Patent Document 2 cannot achieve both high magnetic permeability and low magnetic loss. This is because, in Patent Document 2, since the magnetic metal particles are dispersed in a dielectric material such as polyethylene and press-molded, the ratio of the magnetic particles is as low as 30%, and the magnetic metal particles are sufficiently insulated. It is thought that this is because it cannot be done.

JP-A-2010-238748 Japanese Unexamined Patent Publication No. 2014-116332

The present invention has been made in view of the above problems, and an object of the present invention is a composite magnetic material having high magnetic permeability and low magnetic loss in the high frequency region from the megahertz band to the gigahertz band, particularly in the megahertz band, and a small size using the same. It is to provide high frequency electronic components with low insertion loss.

As a result of diligent studies on a composite magnetic material having high magnetic permeability and low magnetic loss in the high frequency region of the megahertz band, the present inventors have conventionally included a plurality of magnetic nanowires aligned so as not to intersect with each other in the composite magnetic material. Therefore, they have found that a composite magnetic material having a high magnetic permeability and a low magnetic loss can be obtained, and have completed the present invention. Further, the present inventors have found that by including a composite magnetic material or a magnetic substrate containing the composite magnetic material in the high-frequency electronic component, a high-frequency electronic component that is smaller and has a lower insertion loss than the conventional one can be obtained. Has been completed.

That is, the high frequency electronic component of the present invention is
A magnetic core midfoot portion that includes a coil, a plurality of magnetic nanowires aligned so as not to intersect each other, and a composite magnetic material including an insulator that electrically insulates the plurality of magnetic nanowires, and inserts the inside of the coil. The magnetic nanowires contained in the magnetic core midfoot portion are aligned substantially parallel to the winding axis direction of the coil.

According to the composite magnetic material according to the present invention, it is possible to provide a composite magnetic material having high magnetic permeability and low magnetic loss in the high frequency region of the megahertz band and the gigahertz band, particularly in the high frequency region of the megahertz band. Although the mechanism of action in which such an effect is produced has not yet been clarified, the following mechanism of action can be considered.

That is, in the composite magnetic material according to the present invention, since a plurality of magnetic nanowires are aligned so as not to intersect each other, it is possible to easily increase the volume ratio of the magnetic nanowires in the composite magnetic material, and the composite magnetism in the megahertz band. The magnetic permeability of the body can be increased. Further, since the plurality of magnetic nanowires are electrically insulated by an insulator, the eddy current loss can be reduced, and the magnetic loss in the megahertz band can be reduced.

In particular, in the composite magnetic material according to the present invention, since the magnetic nanowires contained in the magnetic core midfoot are aligned substantially parallel to the coil winding axis direction, the direction of the magnetic flux passing through the magnetic core midfoot , The direction in which the magnetic nanowire is easily magnetized (the longitudinal direction of the magnetic nanowire) coincides with that. Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of high-frequency electronic components can be reduced. In addition, the size of the coil included in the high-frequency electronic component can be reduced.

Preferably, the magnetic nanowires contain at least one metal, Fe, Co, Ni.

Preferably, the magnetic nanowires include at least one of a magnetic core upper substrate arranged above the coil and a magnetic core lower substrate arranged below the coil, and are included in at least one of the magnetic core upper substrate and the magnetic core lower substrate. Are aligned substantially perpendicular to the coil winding axis direction. With such a configuration, deterioration of characteristics due to inductor loss is small, and insertion loss can be reduced particularly in the megahertz band. Therefore, among the high frequency regions of the megahertz band and the gigahertz band, particularly in the high frequency region of the megahertz band, it is possible to provide a high frequency electronic component which is small and thin and has low insertion loss.

Further, with such a configuration, the direction of the magnetic flux passing through at least one of the magnetic core upper substrate and the magnetic core lower substrate coincides with the direction in which the magnetic nanowire is easily magnetized (the longitudinal direction of the magnetic nanowire). Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of high-frequency electronic components can be reduced. In addition, the size of the coil included in the high-frequency electronic component can be reduced.

Preferably, the magnetic nanowires including the magnetic core outer foot portion arranged on the peripheral edge of the coil and included in the magnetic core outer foot portion are aligned substantially parallel to the winding axis direction of the coil. With such a configuration, the direction of the magnetic flux passing through the outer foot of the magnetic core coincides with the direction in which the magnetic nanowire is easily magnetized (the longitudinal direction of the magnetic nanowire). Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of the high-frequency electronic component can be further reduced. In addition, the size of the coil included in the high-frequency electronic component can be reduced.

FIG. 1 is a perspective view showing a configuration of a high-frequency electronic component having a composite magnetic material according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II of the high-frequency electronic component shown in FIG. FIG. 3 is a circuit diagram showing a circuit configuration of the high-frequency electronic component shown in FIG. FIG. 4 is a partially enlarged view of the cross-sectional view shown in FIG. FIG. 5 is a perspective view showing the configuration of a high-frequency electronic component having a composite magnetic material according to another embodiment of the present invention.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

The high-frequency electronic component 1 shown in the first embodiment is used for a wireless communication device such as a mobile phone or a wireless LAN communication device. The high-frequency electronic component 1 includes inductors 11, 12, and 17, capacitors 13 to 16, magnetic core midfoot portions 23, 24, a magnetic core upper substrate 21, and a magnetic core lower substrate 22. The high-frequency electronic component 1 has a function as a low-pass filter as shown in FIG. As shown in FIG. 1, each part of the high-frequency electronic component 1 is formed so as to be axisymmetric with an axis parallel to the longitudinal direction (Y-axis direction) of the capacitor 16 as an axis of symmetry.

The inductors 11, 12, 17 and the capacitors 13 to 16 are formed by forming a multilayer substrate composed of a ground layer, an insulating layer and a conductor layer into a shape as shown in FIG. More specifically, as shown in FIGS. 1 and 2, the inductor 11 includes an insulating layer 341, and a plurality of square ring-shaped conductor layers 311 wound counterclockwise are laminated to form a coil. It is composed of a connected coil portion 110. The inductor 12 includes an insulating layer 342, and is composed of a coil portion 120 in which a plurality of square ring-shaped conductor layers 312 wound clockwise are laminated and each is connected in a coil shape.

As shown in FIG. 1, one end of the quadrangular ring-shaped conductor layer constituting the inductor 11 is connected to one end of the quadrangular conductor layer constituting the capacitor 13. One end of the quadrangular ring-shaped conductor layer constituting the inductor 12 is connected to one end of the quadrangular conductor layer constituting the capacitor 14. The other ends of the capacitors 13 and 14 are connected to each other and integrated, and one end of the rectangular conductor layer constituting the capacitor 16 is connected to the intermediate portion in the X-axis direction of the integrated conductor layer. An inductor 17 having a square ring-shaped conductor layer is connected to the other end of the capacitor 16, and a part of the inductor 17 is connected to the ground layer. As shown in FIG. 2, the capacitor 16 is configured by alternately stacking a plurality of insulating layers 336 and conductor layers 316. The capacitors 13 to 15 shown in FIG. 1 have the same configuration as the capacitors 16 shown in FIG.

The magnetic core midfoot portions 23 and 24 are magnetic cores (cores) having the same shape, respectively, and have a function of increasing the inductance of the inductors 11 and 12. The magnetic core midfoot portion 23 is inserted inside the coil portion 110. The magnetic core midfoot portion 24 is inserted inside the coil portion 120. The magnetic core lower substrate 22 constitutes a bottom surface portion of the high-frequency electronic component 1. The magnetic core upper substrate 21 constitutes the upper surface portion of the high frequency electronic component 1.

The magnetic core upper substrate 21 and the magnetic core lower substrate 22 are magnetic substrates and have a function of increasing the inductance of the inductors 11, 12, and 17. As shown in FIG. 2, the magnetic core upper substrate 21 and the magnetic core lower substrate 22 are arranged above and below the coils 11, 12 so as to sandwich the inductors 11, 12, 17 and the capacitors 13 to 16, respectively. Has been done. The thickness T1 of the magnetic core upper substrate 21 in the Z-axis direction (winding axis direction of the inductors 11 and 12) is preferably 100 nm to 1 cm, more preferably 10 to 1000 μm, and particularly preferably 50 to 500 μm. The thickness T1 may be determined according to the length of the magnetic nanowires 362 included in the magnetic core upper substrate 21 described later. The thickness T2 of the magnetic core lower substrate 22 in the Z-axis direction may be the same as the thickness T1 of the magnetic core upper substrate 21 in the Z-axis direction as shown in FIG. 4, or is different from T1 as shown in FIG. You may. The thickness T3 of the magnetic core midfoot portion 23 in the Z-axis direction may be the same as or different from the thickness T1 of the magnetic core upper substrate 21 in the Z-axis direction.

As shown in FIG. 3, the input side terminal of the capacitor 15 is connected to the input terminal 2, and the output side terminal is connected to the output terminal 3. Inductors 11 and 12, which are connected in series, and capacitors 13 and 14, which are connected in series, are connected in parallel to the capacitor 15, respectively. In addition to the input side terminal of the capacitor 14, the output side terminal of the inductor 11, the input side terminal of the inductor 12, and the input side terminal of the capacitor 16 are connected to the output side terminal of the capacitor 13. An inductor 17 is inserted between the output side terminal of the capacitor 16 and the ground.

In the present embodiment, the magnetic core midfoot portions 23 and 24 include a composite magnetic material. The magnetic core midfoot portion 23 made of a composite magnetic material includes a plurality of linear magnetic nanowires 361 arranged so as not to intersect each other, and an insulator 365 that electrically insulates between the plurality of magnetic nanowires 361. As shown in FIG. 4, the plurality of magnetic nanowires 361 are aligned substantially parallel to the winding axis (winding axis c) direction of the inductor 11. That is, the plurality of magnetic nanowires 361 are aligned substantially parallel to the direction of the magnetic flux passing through the magnetic core midfoot portion 23 in the Z-axis direction. The direction substantially parallel to the winding axis direction of the inductors 11 and 12 is a direction substantially perpendicular to the winding direction of the coil portions 110 and 120, or a direction substantially perpendicular to the XY plane including the coil portions 110 and 120. Correspond.

Although not shown, the magnetic core midfoot portion 24 made of a composite magnetic material also electrically insulates a plurality of linear magnetic nanowires 361 arranged so as not to intersect each other and these plurality of magnetic nanowires 361. It includes an insulator 365. Further, the plurality of magnetic nanowires 361 included in the magnetic core midfoot portion 24 are aligned substantially parallel to the winding axis (winding axis c) direction of the inductor 12. That is, the plurality of magnetic nanowires 361 are aligned substantially parallel to the direction of the magnetic flux passing through the magnetic core midfoot portion 24 in the Z-axis direction.

The magnetic nanowire 361 contains at least one metal of Fe, Co and Ni. More specifically, the magnetic nanowire 361 includes, for example, Fe, Co, and Ni as a simple substance of metal, and an alloy of these metals includes, for example, FeCo alloy, FeNi alloy, CoNi alloy, and FeCoNi alloy. Further, the magnetic nanowire 361 may contain a FeSi alloy or a FeSiCr alloy containing other elements in the above metal or alloy. Further, the magnetic nanowire 361 may contain, for example, Cr, Mo, Mn, Cu, Sn, Zn, Al, P, B, V and the like as an arbitrary additive element or as an unavoidable impurity. Magnetic nanowires 361 made of these metals or alloys exhibit soft magnetism.

The volume ratio of the magnetic nanowires 361 in the composite magnetic material is preferably 45% or more and 90% or less. By setting the volume ratio within the above range, it is possible to prevent a decrease in the real part μ'of the magnetic permeability of the composite magnetic material due to the volume ratio being too small, and between the magnetic nanowires 361 due to the volume ratio being too large. It is possible to prevent a decrease in insulation.

The diameter of the magnetic nanowires 361 is preferably 5 nm or more and 500 nm. By setting the diameter of the magnetic nanowire 361 within the above range, it is possible to prevent damage due to insufficient strength of the magnetic nanowire 361 due to the diameter being too small, and the magnetic loss tan δμ of the composite magnetic material due to the diameter being too large. It is possible to prevent the increase.

The length of the magnetic nanowire 361 in the longitudinal direction is not particularly limited, but it is considered that the upper limit of the length is about 1 cm due to the limitation of the manufacturing method of the magnetic wire 361. This is because, in the manufacturing method described later, when the magnetic nanowires 361 are electrodeposited in the holes formed in the insulator 365, the upper limit of the length of the holes is about 1 cm.

When forming the magnetic nanowires 361, it is necessary to form them so that the aspect ratio becomes large. This is because in the megahertz band, the magnetic loss tan δμ of the composite magnetic material can be reduced by increasing the shape magnetic anisotropy of the magnetic nanowires 361.

As analyzed by the present inventors, the lower limit of the aspect ratio of the magnetic nanowires 361 is preferably 20, more preferably 100, and particularly preferably 1000. The upper limit of the aspect ratio of the magnetic nanowires 361 are 2 × 10 ^6, for example a diameter 5 nm, corresponds to the magnetic nanowire 361 of 1cm length.

In this embodiment, since the magnetic nanowire 361 has a high aspect ratio, unlike Patent Document 2, a molding step for uniformly mixing the magnetic metal particles and the resin is not performed. This is because, in order to uniformly mix the resin and the magnetic metal particles, the magnetic metal particles must be spherical or similar shaped particles, or needle-shaped particles having a low aspect ratio. In the method of mixing the magnetic metal particles and the resin as in Patent Document 2, it is practically difficult to make the volume ratio of the magnetic particles 45% or more. However, in the present embodiment, such a method is used. It is not adopted, and the volume ratio of the magnetic nanowires 361 in the composite magnetic material can be easily increased.

The material of the insulator 365 is preferably an oxide or a resin. Examples of the oxide include Al oxide, Si oxide, Cr oxide, Ta oxide, Nb oxide and the like. As the Al oxide, a porous anodic oxide formed by anodizing Al is particularly preferable. This type of porous anode oxide self-organizes to form a periodic porous Al oxide with periodic wire-like cavities with nano-level diameters.

Resins include polystyrene, polybutadiene, polyethylene oxide, polyethylene oxide methyl ether, polymethacrate, polymethacrylic acid ester, polyisoprene, polyNisopropylacrylamide, polybutylmethacrylic acid, polyvinylpyridine, polyferrocenyldimethylsilane, and polyferrocenyl. Ethylmethylsilane, polydimethylsilane, polyethylenepropylene, polyethylene, polytetrabutylmethacrate, polymethylstyrene, polyhydroxystyrene, epoxy resin, acrylic resin, polyimide resin, polyamide resin, phenol resin, silicone resin and other resins. Be done.

Preferably, these resins are combined to form a block copolymer, self-organizing to form a two-dimensional periodic structure in which rod-shaped micelles are hexagonally arranged, and then the rod-shaped micelle portion is removed. This forms an insulator 365 with periodic wire-like cavities of nano-level diameter. Further, if necessary, a surface treatment agent such as a coupling agent or a dispersant, an additive such as a heat stabilizer or a plasticizer may be added.

In the present embodiment, the magnetic core upper substrate 21 and the magnetic core lower substrate 22 include a composite magnetic material. The magnetic core upper substrate 21 includes a plurality of linear magnetic nanowires 362 aligned so as not to intersect each other, and an insulator 366 that electrically insulates between the plurality of magnetic nanowires 362. Further, the magnetic core lower substrate 22 includes a plurality of linear magnetic nanowires 363 arranged so as not to intersect each other, and an insulator 367 that electrically insulates between the plurality of magnetic nanowires 363.

As shown in FIG. 4, the magnetic nanowires 362 are aligned substantially perpendicular to the winding axis direction of the inductor 11. That is, the magnetic nanowires 362 are aligned substantially parallel to the direction of the magnetic flux passing through the magnetic core upper substrate 21 in the X-axis direction. Further, the magnetic nanowires 363 are aligned substantially perpendicular to the winding axis direction of the inductor 11. That is, the magnetic nanowires 363 are aligned substantially parallel to the direction of the magnetic flux passing through the magnetic core lower substrate 22 in the X-axis direction. The configuration of the magnetic nanowires 362 and 363 is the same as that of the magnetic nanowires 361 described above.

Next, a method of manufacturing the high-frequency electronic component 1 will be described. First, an insulator having a periodic porous structure having a plurality of pores arranged so as not to intersect each other (for example, the above-mentioned periodic porous Al oxide) is prepared, and magnetic nanowires are electrodeposited inside these pores. To produce a composite magnetic material. Then, this composite magnetic material is processed into a predetermined shape and size to produce the magnetic core upper substrate 21, the magnetic core lower substrate 22, and the magnetic core midfoot portion 23. Alternatively, the insulator is processed into a predetermined shape and size in advance, and magnetic nanowires are electrodeposited inside the holes of the insulator to form a composite magnetic material (magnetic core upper substrate 21, magnetic core lower substrate 22 and magnetic core). The foot portion 23) is manufactured.

Further, a circuit pattern substrate in which the inductors 11, 12, 17 and the capacitors 13 to 16 shown in FIG. 1 are incorporated is manufactured. For example, the inductor 11 is manufactured by stacking a plurality of square ring-shaped conductor layers 311 shown in FIG. 2 and connecting each of them in a coil shape. Further, the inductor 12 is also manufactured in the same manner. Although detailed illustration is omitted, the inductor 17 and the capacitors 13 to 16 shown in FIG. 1 are also manufactured by laminating a plurality of conductive layers and insulating layers. Then, these are integrated to produce a circuit pattern substrate (see FIG. 2) in which the low-pass filter shown in FIG. 3 is built.

Next, this circuit pattern substrate is installed on the upper surface of the magnetic core lower substrate 22, the magnetic core middle foot portion 23 is inserted into the opening 111 inside the coil portion 110 shown in FIG. 4, and the magnetic core lower substrate 22 The magnetic core midfoot portion 23 is installed on the upper surface. Similarly, the magnetic core midfoot portion 24 shown in FIG. 1 is also installed on the upper surface of the magnetic core lower substrate 22. Then, the magnetic core upper substrate 21 is put on the circuit pattern and the respective parts are joined to obtain the high frequency electronic component 1. The magnetic core upper substrate 21, the magnetic core lower substrate 22, the magnetic core midfoot portions 23, 24, and the circuit pattern substrate may be joined by an adhesive.

According to the composite magnetic material according to the present embodiment, it is possible to provide a composite magnetic material having high magnetic permeability and low magnetic loss in the high frequency region of the megahertz band and the gigahertz band, particularly in the high frequency region of the megahertz band. Although the mechanism of action in which such an effect is produced has not yet been clarified, the following mechanism of action can be considered.

That is, in the composite magnetic material according to the present embodiment, since the plurality of magnetic nanowires 361, 362, 363 are aligned so as not to intersect each other, the volume ratio of the magnetic nanowires 361, 362, 363 in the composite magnetic material can be easily set. It becomes possible to increase the magnetic permeability of the composite magnetic material in the megahertz band. Further, since the plurality of magnetic nanowires 361, 362, 363 are electrically insulated by the insulators 365, 366, 367, the eddy current loss can be reduced, and the magnetic loss in the megahertz band is reduced. be able to.

In particular, in the composite magnetic material according to the present embodiment, the magnetic nanowires 361 included in the magnetic core midfoot portions 23 and 24 are aligned substantially parallel to the winding axis direction of the inductors 11 and 12, so that the magnetic core midfoot The direction of the magnetic flux passing through the portions 23 and 24 coincides with the easy magnetization direction of the magnetic nanowire 361 (longitudinal direction of the magnetic nanowire 361). Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of the high-frequency electronic component 1 can be reduced. Further, the size of the inductors 11 and 12 included in the high frequency electronic component 1 can be reduced.

Further, the high-frequency electronic component 1 according to the present embodiment includes a magnetic core upper substrate 21 arranged above the inductors 11 and 12 and a magnetic core lower substrate 22 arranged below the inductors 11 and 12, and includes the magnetic core upper substrate 21 and the magnetic core upper substrate 22. The magnetic nanowires 362 and 363 included in the magnetic core lower substrate 22 are aligned substantially perpendicular to the winding axis direction of the inductors 11 and 12. Therefore, the deterioration of the characteristics due to the inductor loss is small, and the insertion loss can be reduced especially in the megahertz band. Therefore, among the high frequency regions of the megahertz band and the gigahertz band, particularly in the high frequency region of the megahertz band, it is possible to provide the high frequency electronic component 1 which is small and thin and has low insertion loss.

Further, with such a configuration, the direction of the magnetic flux passing through the magnetic core upper substrate 21 and the magnetic core lower substrate 22 and the direction in which the magnetic nanowires 362 and 363 are easily magnetized (the longitudinal direction of the magnetic nanowires 362 and 363) coincide with each other. To do. Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of the high-frequency electronic component 1 can be reduced. Further, the size of the inductors 11 and 12 included in the high frequency electronic component 1 can be reduced.

Further, the high-frequency electronic component 1 according to the present embodiment includes the magnetic core outer foot portions 24 and 25 arranged on the peripheral edges of the inductors 11 and 12, and the magnetic nanowires 364 and 365 included in the magnetic core outer foot portions 24 and 25 are The inductors 11 and 12 are aligned substantially parallel to the winding axis direction. Therefore, the direction of the magnetic flux passing through the magnetic core outer foot portions 24 and 25 coincides with the easy magnetization direction of the magnetic nanowires 364 and 365 (longitudinal direction of the magnetic nanowires 364 and 365). Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of the high-frequency electronic component 1 can be further reduced. Further, the size of the inductors 11 and 12 included in the high frequency electronic component 1 can be reduced.

Second Embodiment The high-frequency electronic component 1A having the composite magnetic material of the present embodiment shown in FIG. 5 has the same configuration and operation effect as those of the first embodiment described above except for the points shown below, and is a common portion. In the drawings, common members are designated by common member codes. As shown in FIG. 5, the high-frequency electronic component 1A differs from the high-frequency electronic component 1 in that it further has magnetic core outer foot portions 25 and 26.

The magnetic core outer foot portions 25 and 26 are magnetic cores (cores) having the same shape, respectively, and have a function of increasing the inductance of the inductors 11 and 12. The magnetic core outer foot portions 25 and 26 have a rectangular shape and are arranged on the peripheral edges of the coils 11 and 12.

In the present embodiment, the magnetic core outer foot portions 25 and 26 include a composite magnetic material. The magnetic core outer legs 25 and 26 made of a composite magnetic material include a plurality of linear magnetic nanowires 364 arranged so as not to intersect each other, and an insulator 368 that electrically insulates between the plurality of magnetic nanowires 364. .. As shown in FIG. 5, the plurality of magnetic nanowires 364 are substantially parallel to the winding axis (winding axis c) direction of the inductor 11 (with respect to the direction of the magnetic flux passing through the region C shown in the drawing in the Z axis direction). (Approximately parallel). The configuration of the magnetic nanowires 364 is the same as that of the magnetic nanowires 361 described above.

The magnetic core outer foot portions 25 and 26 can be manufactured by processing the composite magnetic material manufactured by the manufacturing method described in the first embodiment into a predetermined size and shape. Further, the high frequency electronic component 1A is manufactured by adding the steps of installing the magnetic core outer legs 25 and 26 to the outside of the coil portion 110 on the upper surface of the magnetic core lower substrate 22 shown in FIG. 5 to the above manufacturing method. Can be done.

Also in this embodiment, the same effect as that of the above embodiment can be obtained. In addition, in the present embodiment, the magnetic nanowires 364 included in the magnetic core outer foot portions 25 and 26 are aligned substantially parallel to the winding axis direction of the coils 11 and 12. Therefore, the direction of the magnetic flux passing through the magnetic core outer foot portions 25 and 26 coincides with the easy magnetization direction of the magnetic nanowire 364 (longitudinal direction of the magnetic nanowire 361). Therefore, the eddy current loss is reduced especially in the megahertz band, the magnetic loss is reduced, and the insertion loss of the high-frequency electronic component 1 can be further reduced.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

In the above embodiment, the magnetic core upper substrate 21, the magnetic core lower substrate 22, the magnetic core middle foot portions 23, 24, and the magnetic core outer foot portions 25, 26 are all composed of a composite magnetic material, but the magnetic core upper substrate 21 and the magnetic core lower portion are formed. Only a part of each of the substrate 22, the magnetic core middle foot portions 23 and 24, and the magnetic core outer foot portions 25 and 26 may be made of a composite magnetic material.

In the above embodiment, an example in which the circuit patterns of the inductors 11, 12, 17 and the capacitors 13 to 16 prepared in advance at the time of manufacturing the high-frequency electronic component 1 are installed on the upper surface of the magnetic core lower substrate 22 has been shown. The manufacturing method of the high-frequency electronic component 1 is not limited to this. For example, the coil portion 110 may be formed by laminating a plurality of conductive pastes and insulating pastes on the upper surface of the magnetic core lower substrate 22 and connecting each of them in a coil shape. Similarly, the inductors 12 and 17 and the capacitors 13 to 16 may be formed by laminating a plurality of conductive pastes and insulating pastes on the upper surface of the magnetic core lower substrate 22.

In the above embodiment, the lengths of the magnetic nanowires 361 and 364 may be shortened within a range in which the aspect ratio does not become too small, and these may be multi-layered and included in the magnetic core midfoot portions 23 and 24 and the magnetic core outer foot portions 25 and 26. Good. However, the magnetic nanowires 361 and 364 shown in FIG. 5 have three or more layers. Similarly, the lengths of the magnetic nanowires 362 and 363 may be shortened within a range in which the aspect ratio does not become too small, and these may be included in the magnetic core upper substrate 21 and the magnetic core lower substrate 22.

In FIGS. 4 and 5, the thicknesses of the magnetic core midfoot portions 23 and 24 and the magnetic core outer foot portions 25 and 26 in the Z-axis direction may be increased, and magnetic nanowires 361 and 364 may be included in layers inside them. However, the magnetic nanowires 361 and 364 shown in FIG. 5 have three or more layers. Further, the thickness of the magnetic core upper substrate 21 and the magnetic core lower substrate 22 in the Z-axis direction may be increased, and magnetic nanowires 362 and 363 may be further formed in multiple layers inside them.

In the examples shown in FIGS. 4 and 5, the plurality of magnetic nanowires 361 to 364 are arranged in an orderly manner so as not to intersect each other, but they may be arranged somewhat randomly as long as they do not intersect each other. Further, in the examples shown in FIGS. 4 and 5, the lengths of the plurality of magnetic nanowires 361 to 364 were substantially the same, but they may be slightly different.

Further, the magnetic nanowires 361 to 364 may be substantially linear, and may have some distortion (bending) as long as they are insulated without intersecting each other. Further, the magnetic nanowires 362 and 363 need only be substantially aligned substantially perpendicular to the winding axis c (Z axis) of the inductor 11, and if they are insulated without intersecting each other, the winding axis c It may be slightly inclined with respect to the vertical line of. That is, the magnetic nanowires 362 and 363 may be inclined with respect to the vertical line of the winding axis c (Z axis) preferably within a range of ± 45 degrees, and more preferably wound within a range of ± 30 degrees. It may be inclined with respect to the vertical line of the rotation axis c (Z axis), and particularly preferably within a range of ± 15 degrees with respect to the vertical line of the winding axis c (Z axis). ..

Further, the magnetic nanowires 361 and 364 need only be substantially parallel to the winding shaft c (Z axis) of the inductor 11, and if they are insulated without intersecting each other, the winding shaft c It may be slightly inclined with respect to (Z-axis). That is, the magnetic nanowires 361 and 364 may be inclined with respect to the winding axis c (Z axis) preferably within a range of ± 45, and more preferably within a range of ± 30 degrees. It may be inclined with respect to the vertical line of the winding axis c (Z axis), particularly preferably within a range of ± 15 degrees. By inclining the magnetic nanowires 361 to 64 at such an inclination angle, it is possible to impart a high level of strength and magnetic permeability to the composite magnetic material.

In the above embodiment, an example of application of the present invention to a low-pass filter has been shown, but the present invention may be applied to other high-frequency electronic components. Other high frequency electronic components include inductors, filters or antennas that can be used in the high frequency region of the megahertz band or gigahertz band. More specifically, for chip inductors, SAW filters, BAW filters, EMI filters, LTCCs, thin film filters, duplexers, bandpass filters, baluns, diplexers, RF front ends, couplers, highly integrated modules for wireless connectivity and power management, etc. The present invention may be applied.

Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited to these examples.

(Example 1)
Preparation of High Frequency Electronic Component 1 The Al foil was anodic oxidized in a 0.3 M oxalic acid solution at a voltage of 40 V to prepare a periodic porous Al oxide having a thickness of 60 μm and a pore diameter of 100 nm. In an electrolytic solution composed of 1 M ferric sulfate, 0.7 M boric acid, and 1 mM sodium ascorbate, the cathode is an Al foil connected to a porous Al oxide, the anode is Fe, and the temperature is maintained at 50 ° C. Fe magnetic nanowires 361-363 were electrolyzed into the pores of the periodic porous Al oxide by AC electrolysis at 500 Hz. The length of the magnetic nanowires 361 to 363 in the longitudinal direction was 21 μm, and the diameter of the magnetic nanowires 361 to 363 was 98 nm. The volume ratio of the magnetic nanowires 361 to 363 determined from the porosity of the periodic porous Al oxide as the insulator 365 to 367 was 51%. In this way, the composite magnetic material of Example 1 composed of Fe magnetic nanowires 361-363 and the Al oxide insulator 365 to 367 was obtained.

The length L of the inductor 11 that can obtain the desired inductance when the composite magnetic material is used as the magnetic core upper substrate 21, the magnetic core lower substrate 22, and the magnetic core midfoot portions 23 and 24 is simulated. Then, based on the simulation result, the magnetic core upper substrate 21, the magnetic core lower substrate 22, and the magnetic core midfoot portions 23 and 24 were designed and manufactured.

The magnetic core midfoot portions 23 and 24 were formed so that the magnetic nanowires 361 were aligned substantially parallel to the winding axis direction of the inductors 11 and 12. Further, the magnetic core upper substrate 21 and the magnetic core lower substrate 22 are formed so that the magnetic nanowires 362 and 363 are aligned substantially perpendicular to the winding axis direction of the inductors 11 and 12.

In addition, a circuit pattern substrate incorporating the inductors 11, 12, 17 and capacitors 13 to 16 shown in FIG. 1 was manufactured. For example, as shown in FIG. 4, the inductor 11 was manufactured by stacking a plurality of square ring-shaped conductor layers 311 and connecting each of them in a coil shape. The inductor 12 was also manufactured in the same manner. Although detailed illustration is omitted, the inductor 17 and the capacitors 13 to 16 are also manufactured by laminating a plurality of conductive layers and insulating layers. Then, these were integrated to produce a circuit pattern substrate in which the low-pass filter shown in FIG. 3 was built.

Next, this circuit pattern substrate is installed on the upper surface of the magnetic core lower substrate 22, the magnetic core middle foot portion 23 is inserted into the opening 111 inside the coil portion 110 shown in FIG. 4, and the magnetic core lower substrate 22 A magnetic core midfoot portion 23 was installed on the upper surface. Similarly, the magnetic core midfoot portion 24 was installed on the upper surface of the magnetic core lower substrate 22. Then, the magnetic core upper substrate 21 was put on the circuit pattern, and each part was bonded with a resin to obtain a high-frequency electronic component 1.

Evaluation <Magnetic nanowire shape, composition, and volume ratio>
Observe the cross section of the composite magnetic material with a scanning electron microscope (SEM) (SU8000, manufactured by Hitachi High-Technologies Corporation), measure the width and length of the magnetic nanowires 361-363, and use the attached EDX to measure the magnetic nanowires. The composition of 361-363 was measured. The volume ratio of the magnetic nanowires 361 to 363 was determined from the weight of the unit area of the porous insulator, the weight of the magnetic nanowire after electrodeposition, and the specific gravity of the insulator 365 to 367 and the magnetic nanowires 361 to 363.

<Real part μ'and magnetic loss tan δμ of complex magnetic permeability>
A composite magnetic material using a test piece processed into a rod shape of 1 mm x 1 mm x 80 mm, using a network analyzer (manufactured by Agilent Technologies, HP8753D) and a cavity resonator (manufactured by Kanto Electronics Applied Development Co., Ltd.). The real part μ'and the magnetic loss tan δμ of the complex magnetic permeability at 2.4 GHz were measured by the perturbation method.

<Inductor length L and insertion loss IL of high-frequency electronic component 1>
The insertion loss IL of the high frequency electronic component 1 at 700 MHz was measured. Table 1 shows the real part μ'and magnetic loss tan δμ of the complex magnetic permeability at 700 MHz of the composite magnetic material, the lengths L of the inductors 11 and 12, and the insertion loss IL of the high-frequency electronic component 1.

(Example 2)
The composite magnetic material of Example 2 and the high-frequency electronic component 1 were produced in the same manner as in Example 1 except that the composite magnetic material was produced by a method different from that of Example 1 as follows, and the same experiment was performed. ..

After anodic oxidation of the Al foil in a 0.3 M perchloric acid solution at a voltage of 40 V, the anodic oxide film in contact with the Al foil and the Al foil is dissolved in a sodium hydroxide solution to have a thickness of 70 μm and a pore diameter of 20 nm. A periodic porous Al oxide was prepared. An Al sputter-deposited layer was formed on one side of this periodic porous Al oxide to serve as a cathode. Co was used as the anode, and the period was maintained in an electrolytic solution composed of 0.7 M ferric sulfate, 0.3 M cobalt sulfate, 0.7 M boric acid, and 1 mM sodium ascorbate kept at 50 ° C. FeCo alloy magnetic nanowires 361-363 were DC electrodeposited in the pores of the porous Al oxide. Then, the Al sputter-deposited layer was removed with a sodium hydroxide solution. Here, the diameter of the magnetic nanowires 361 to 363 was 19 nm, and the length of the magnetic nanowires 361 to 363 was 60 μm. Moreover, when the composition was evaluated by EDX, the composition of the magnetic nanowires 361 to 363 was 64% Fe and 36% Co. The volume ratio of the magnetic nanowires 361 to 363 determined from the porosity of the periodic porous Al oxide as the insulator 365 to 367 was 74%. As described above, the composite magnetic material of Example 2 composed of FeCo alloy magnetic nanowires 361-363 and the Al oxide insulator 365 to 367, and the high-frequency electronic component 1 containing the composite magnetic material were obtained.

(Example 3)
The composite magnetic material of Example 3 and the high-frequency electronic component 1 were produced in the same manner as in Example 1 except that the composite magnetic material was produced by a method different from that of Example 1 as follows, and the same experiment was performed. ..

A block copolymer using poly (ethylene oxide) methyl ether (molecular weight 5000) as a hydrophilic block and polymethacrylate having a degree of polymerization of 50 to 150 as a hydrophobic block is synthesized by an atomic transfer radical polymerization method using a copper complex as a catalyst. did. The obtained block copolymer was represented by the general formula (Chemical Formula 1).

Here, m is 80 to 120, n is 50 to 80, and R is an alkyl group.

The obtained 0.02 g block copolymer was mixed with 0.01 g polyethylene oxide (molecular weight 400, degree of polymerization 7) and dissolved in chloroform to obtain a 10 wt% solution. Using this solution, an Al foil ultrasonically cleaned with isopropanol was bar-coated to a thickness of 1 μm. Then, heat treatment was performed at 140 ° C. for 1 hour, and the hydrophilic block was removed with a 0.3 M aqueous solution of phosphoric acid-disodium hydrogen phosphate having a pH of 6.9 to obtain a thickness of 1 μm and a pore size of 10 nm on the Al foil. A periodic porous copolymer film was prepared.

Periodically porous copolymer in an electrolytic solution composed of 0.7 M ferric sulfate, 0.3 M cobalt sulfate, 0.7 M boric acid, and 1 mM sodium ascorbate, whose anode is Co and kept at 50 ° C. FeCo alloy magnetic nanowires 361-363 were DC electrodeposited in the pores of the coalesced film. Then, the Al foil was removed with a sodium hydroxide solution. Here, the diameter of the magnetic nanowires 361 to 363 was 10 nm, and the length of the magnetic nanowires 361 to 363 was 1 μm. When the composition was evaluated by EDX, the composition of the magnetic nanowires 361 to 363 was 64% Fe and 36% Co. The volume ratio of the magnetic nanowires 361 to 363 determined from the porosity of the periodic porous copolymer film as an insulator was 74%. In this way, the composite magnetic material of Example 3 composed of FeCo alloy magnetic nanowires 361-363 and the periodic porous copolymer film insulator, and the high-frequency electronic component 1 containing the composite magnetic material were obtained.

Here, the magnetic core midfoot portions 23 and 24 are formed so that the magnetic nanowires 361 are aligned substantially perpendicular to the winding axis direction of the inductor 11. Further, the magnetic core upper substrate 21 and the magnetic core lower substrate 22 are formed so that the magnetic nanowires 362 and 363 are aligned substantially parallel to the winding axis direction of the inductor 11.

(Comparative Example 1)
The composite magnetic material of Comparative Example 1 and the high-frequency electronic component 1 were produced in the same manner as in Example 1 except that the composite magnetic material was produced by a method different from that of Example 1 as follows, and the same experiment was performed. ..

73 mol% of iron oxide (Fe ₂ O ₃ ), 18 mol% of cobalt oxide (Co ₃ O ₄ ), and 9 mol% of barium carbonate (BaCO ₃ ) were used as raw materials, and these were weighed so as to have a predetermined composition. Then, the raw material after weighing was blended in a wet ball mill using water as a medium for 16 hours, and then calcined in the air at 1250 ° C. The magnetic oxide thus obtained was pulverized by a vibration mill for 10 minutes, then pulverized with a wet ball mill using water as a medium for 88 hours, and the pulverized magnetic oxide was dried at 150 ° C. for 24 hours to obtain an average particle size. A magnetic oxide powder (magnetic oxide powder W) having a size of 1 μm or less was prepared. This magnetic oxide contains Co-substituted W-type hexagonal ferrite (BaCo ₂ Fe ₁₆ O ₂₇ ) as a main component. In this way, the composite magnetic material of Comparative Example 1 and the high-frequency electronic component 1 containing the composite magnetic material were obtained.

(Comparative Example 2)
The composite magnetic material of Comparative Example 2 and the high-frequency electronic component 1 were manufactured in the same manner as in Comparative Example 1 except that the composite magnetic material was manufactured by a method different from that of Comparative Example 1 as follows, and the same experiment was performed. ..

Fe ₇₀ Co ₃₀ alloy needle-shaped particles having a major axis length of 45 nm and an aspect ratio of 1.5, polyethylene resin as a dielectric material, and the ratio of needle-shaped magnetic particles to polyethylene resin are 30 vol%: 70 vol%. Weighed as follows. A dispersant and a coupling agent were appropriately added to the above materials, and the mixture was kneaded using a mixing roll (No191-TM / WM) manufactured by Yasuda Seiki Seisakusho. Kneading was carried out while heating the raw material to 140 ° C. until the needle-shaped magnetic particles were uniformly mixed in the polyethylene resin. Next, the obtained raw material mixture was put into a mold heated to 180 ° C. and molded with a press pressure of 35 MPa. In this way, the magnetic composite material of Comparative Example 2 and the high-frequency electronic component 1 containing the magnetic composite material were obtained.

As shown in Table 1, in Examples 1 to 3, it was confirmed that the real part μ'of the complex magnetic permeability at 700 MHz was 2.5 or more, and the magnetic loss tan δμ was 0.02 or less. On the other hand, in Comparative Examples 1 and 2, it was confirmed that the real part μ'of the complex magnetic permeability at 700 MHz was 2.5 or less and the magnetic loss tan δμ was 0.02 or more. That is, it was confirmed that the composite magnetic material according to this example has a real part μ'with a high complex magnetic permeability and a low magnetic loss tan δμ in the megahertz band.

Further, in Examples 1 to 4, it was confirmed that the length L of the inductors 11 and 12 was 2000 μm or less, and the insertion loss IL of the high-frequency electronic component 1 was 0.41 dB or less. On the other hand, in Comparative Examples 1 and 2, it was confirmed that the length L of the inductors 11 and 12 was 2100 μm or more, and the insertion loss IL of the high-frequency electronic component 1 was 1.00 dB or more. That is, in the high-frequency electronic component 1 containing the composite magnetic material according to this embodiment, the length L of the inductors 11 and 12 can be reduced, so that the high-frequency electronic component 1 itself can be miniaturized and the insertion loss can be reduced. It was confirmed that a high-frequency electronic component 1 having a small IL and excellent characteristics can be obtained.

1,1A ... High-frequency electronic components 11,12,17 ... Inductors 110,120 ... Coil parts 111,121 ... Openings 13,14,15,16 ... Capacitors:
21 ... Magnetic core upper substrate 22 ... Magnetic core lower substrate 23, 24 ... Magnetic core middle foot 25, 26 ... Magnetic core outer foot 311, 312,316 ... Conductor layer 341, 342, 336 ... Insulation layer 361, 362, 363, 364 ... Magnetic nanowires 365, 366, 367, 368 ... Insulator

Claims (4)

With the coil
It contains a composite magnetic material including a plurality of magnetic nanowires arranged so as not to intersect each other and an insulator having a periodic porous structure and electrically insulating between the plurality of magnetic nanowires, and inserts the inside of the coil. It has a magnetic core midfoot and
The magnetic nanowires contained in the magnetic core midfoot portion are aligned substantially parallel to the winding axis direction of the coil .
A high-frequency electronic component in which the volume ratio of the magnetic nanowires in the composite magnetic material is 45% or more and 90% or less . The high-frequency electronic component according to claim 1, wherein the magnetic nanowire contains at least one metal of Fe, Co, and Ni. Includes at least one of a magnetic core upper substrate located above the coil and a magnetic core lower substrate located below the coil.
The high-frequency electronic component according to claim 1 or 2, wherein the magnetic nanowires contained in at least one of the magnetic core upper substrate and the magnetic core lower substrate are aligned substantially perpendicular to the winding axis direction of the coil. Includes a magnetic core outer foot located on the periphery of the coil
The high-frequency electronic component according to any one of claims 1 to 3, wherein the magnetic nanowires included in the magnetic core outer foot portion are aligned substantially parallel to the winding axis direction of the coil.

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