TWI828865B - Manufacturing method of inductor - Google Patents

Abstract

The manufacturing method of the inductor 1 of the present invention includes: in the first step, the wiring 2 is arranged on a surface in the thickness direction of the substrate. The wiring 2 is provided with a conductor 6 and an insulating layer 7 covering the conductor 6, and has a cross-sectional shape of approximately Circular shape; the second step is to arrange the first magnetic sheet 51 on a surface in the thickness direction of the first release sheet 41 in a superior arc covering the circumferential surface of the wiring 2. The first magnetic sheet 51 Containing the first magnetic particles and the first adhesive 91 for dispersing the first magnetic particles; and the fourth step is to cover a surface of the first magnetic sheet 51 in the thickness direction with the second magnetic sheet 52. The second magnetic sheet 52 contains second magnetic particles and a second adhesive 92 for dispersing the second magnetic particles. The first magnetic sheet 51 covers the arc of the circumferential surface of the wiring 2 and the first release sheet. One surface of material 41.

Description

Manufacturing method of inductor

The present invention relates to a manufacturing method of an inductor.

Conventionally, it has been known that inductors are mounted on electronic equipment and used as passive components of voltage conversion components and the like.

For example, an inductor has been proposed that includes a rectangular parallelepiped wafer body made of a magnetic material and an internal conductor such as copper embedded in the wafer body (see Patent Document 1).

In Patent Document 1, an inductor is manufactured by laminating a plurality of conductor layers containing conductive paste by printing. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-144526

[Problem to be solved by the invention]

However, in recent years, higher inductance requirements have been placed on inductors.

The present invention provides a manufacturing method capable of manufacturing an inductor with excellent inductance. [Technical means to solve problems]

The present invention (1) includes a method for manufacturing an inductor, which includes: a first step of arranging wiring on a surface in the thickness direction of a substrate. The wiring includes a conductor and an insulating layer covering the conductor, and has a cross-sectional shape of approximately Circular shape; the second step is to arrange the first magnetic sheet on a surface in the thickness direction of the above-mentioned substrate in such a manner that it covers an area exceeding 180° in the circumferential surface of the wiring. Containing first magnetic particles and a first binder for dispersing the first magnetic particles; and the fourth step is to cover a surface of the first magnetic sheet in the thickness direction with a second magnetic sheet, and the above-mentioned first magnetic sheet is covered with a second magnetic sheet. 2. The magnetic sheet contains second magnetic particles including second anisotropic magnetic particles aligned in the plane direction, and a second binder for dispersing the second magnetic particles, and the first magnetic sheet covers the circumference The above-mentioned area of the surface and the above-mentioned surface of the above-mentioned substrate.

In this method, in the second step, the first magnetic sheet is arranged on a surface of the substrate in the thickness direction so as to cover an area exceeding 180° when viewed in cross-section in the circumferential surface of the wiring, so that the first magnetic sheet can be densely arranged. 1 magnetic particles. As a result, an inductor with excellent inductance can be manufactured.

Furthermore, in the fourth step, the second magnetic sheet covers one surface of the first magnetic sheet in the thickness direction, so that the first magnetic particles and the second magnetic particles can be densely arranged in the peripheral area of the wiring. Therefore, an inductor with better inductance can be manufactured.

Therefore, according to this manufacturing method, the first magnetic particles and the second magnetic particles can be densely arranged in the peripheral area, and an inductor having excellent inductance can be manufactured.

The present invention (2) includes the method for manufacturing an inductor as described in (1), wherein the first magnetic particles include first anisotropic magnetic particles, and the first anisotropic magnetic particles are in the first magnetic sheet. Aligned in the face direction.

According to this method, in the second step, the first magnetic sheet is arranged on a surface in the thickness direction of the substrate, and in the first magnetic sheet, the first anisotropic magnetic particles are aligned along a surface in the thickness direction of the substrate. Therefore, it is possible to suppress the alignment of the first anisotropic magnetic particles in the circumferential direction of the wiring at both ends of the circumferential direction in the region of the wiring facing one surface in the thickness direction. Therefore, the inductor has excellent DC superposition characteristics.

Furthermore, since the first magnetic sheet covers an area exceeding 180° on the circumferential surface of the wiring, the alignment direction of the first anisotropic magnetic particles can be changed from the circumferential direction of the wiring at both ends of the area in the circumferential direction. The first anisotropic magnetic particles are densely arranged along the direction of one surface of the substrate. As a result, an inductor with better inductance can be manufactured.

Therefore, according to this method, an inductor with excellent inductance and DC superposition characteristics can be manufactured.

The present invention (3) includes the manufacturing method of an inductor as described in (1) or (2), wherein the substrate is a release sheet, and the manufacturing method of the inductor further includes: a third step of removing the substrate ; and the fifth step, which is to arrange the third magnetic sheet on the other side of the first magnetic sheet in the thickness direction so as to cover the circumferential surface exposed from the other surface of the first magnetic sheet in the thickness direction. On the surface, the third magnetic sheet contains third magnetic particles and a third binder for dispersing the third magnetic particles.

In this method, since the third magnetic sheet is further arranged on the other surface in the thickness direction of the first magnetic sheet, the first magnetic particles and the second anisotropic magnetic particles in the peripheral area of the wiring can be densely arranged. and the third magnetic particle. Therefore, an inductor with better inductance can be manufactured.

In particular, since the third magnetic sheet covers the circumferential surface exposed from the other surface of the first magnetic sheet in the thickness direction, it can be densely packed in the area corresponding to the circumferential surface of the wiring exposed from the first magnetic sheet. Arrange the third magnetic particle. As a result, an inductor with excellent inductance can be manufactured.

The present invention (4) includes the method for manufacturing an inductor as described in (3), wherein the third magnetic particles include third anisotropic magnetic particles, and the third anisotropic magnetic particles are in the third magnetic sheet. Aligned in the face direction.

According to this method, in the fifth step, the third anisotropic magnetic particles can be aligned in a region corresponding to the circumferential surface of the wiring exposed from the first magnetic sheet, and the third anisotropic magnetic particles can be densely arranged . As a result, an inductor with better inductance can be manufactured.

The present invention (5) includes the manufacturing method of an inductor as described in (3) or (4), which involves sequentially implementing the above-mentioned first step, the above-mentioned second step and the above-mentioned third step, and then simultaneously implementing the above-mentioned fourth step. steps and step 5 above.

In this method, since the fourth step and the fifth step are performed at the same time, the manufacturing time can be shortened compared with a method in which the fourth step and the fifth step are performed sequentially. Therefore, the inductor can be manufactured efficiently.

The present invention (6) includes the manufacturing method of an inductor as described in any one of (3) to (5), wherein the first adhesive in the second step and the third adhesive in the fifth step are The agent contains a B-stage thermosetting component, and the manufacturing method of the inductor further includes a sixth step. The sixth step is to simultaneously make the above-mentioned B-stage thermosetting component of the above-mentioned first adhesive and the above-mentioned third adhesive C-stage. change.

In this method, in the sixth step, the B-stage thermosetting components of the first adhesive and the third adhesive are simultaneously C-staged, so the B-stage heat curing components of the first adhesive and the third adhesive are The manufacturing time can be shortened compared to the method in which the hardening components are C-staged sequentially. Therefore, the inductor can be manufactured efficiently.

The present invention (7) includes the method for manufacturing an inductor as described in (1) or (2), wherein the substrate is a third magnetic sheet containing third magnetic particles, and a method for converting the third magnetic particles The dispersed third adhesive is a cured product containing a thermosetting component.

In this method, since the substrate is the third magnetic sheet, there is no need to perform a step of removing the substrate such as a release film. Therefore, the number of steps can be reduced and the inductor can be easily manufactured.

The present invention (8) includes the method for manufacturing an inductor according to (7), wherein the third magnet particles include third anisotropic magnet particles, and the third anisotropic magnet particles are in the third magnet sheet. Aligned in the face direction.

In this method, since the third magnetic particles include the third anisotropic magnetic particles aligned in the plane direction in the third magnetic sheet, the third anisotropic magnetic particles can be directed toward the surface of the third magnetic sheet along the wiring. Partial alignment. Therefore, an inductor with better inductance can be manufactured. [Effects of the invention]

The manufacturing method of the inductor of the present invention can manufacture an inductor with excellent inductance.

<First Embodiment> 1.Inductor The inductor obtained according to the first embodiment of the present invention will be described with reference to FIGS. 1A to 2B.

Furthermore, FIG. 1A shows a cross-section with hatching processing, and FIG. 1B is a cross-sectional view showing the alignment of anisotropic magnetic particles in the magnetic layer. Furthermore, in the present drawings including FIG. 1B , the shape and arrangement of the magnetic particles (including anisotropic magnetic particles) are exaggeratedly drawn in order to facilitate understanding of the present invention.

As shown in FIGS. 1A and 1B , the inductor 1 has a shape extending in the surface direction. Specifically, the inductor 1 has one surface and another surface facing each other in the thickness direction, and each of the one surface and the other surface has a direction included along the surface direction, and the wiring 2 (described below) transmits The direction of the current (corresponding to the depth direction of the paper) and the flat shape of the first direction orthogonal to the thickness direction.

Inductor 1 includes wiring 2 and magnetic layer 3 .

The wiring 2 has a substantially circular shape in cross section. Specifically, the wiring 2 has a substantially circular shape when cut at a cross section (first direction cross section) orthogonal to the second direction (transmission direction) (depth direction of paper) which is the direction in which current is transmitted.

The wiring 2 is an electric wire covered with an insulating layer, and specifically includes a conductor 6 and an insulating layer 7 covering the conductor 6 .

The conductive wire 6 is a conductive wire having a shape extending long in the second direction. In addition, the conductor 6 has a substantially circular cross-sectional shape sharing a central axis with the wiring 2 .

Examples of the material of the conductor 6 include metal conductors such as copper, silver, gold, aluminum, nickel, and alloys thereof. Preferably, copper is used. The conductor 6 may have a single-layer structure, or may have a multi-layer structure in which the surface of the core conductor (such as copper) is plated (such as nickel).

The radius R1 of the conductor 6 is, for example, 25 μm or more, preferably 50 μm or more, and is, for example, 2000 μm or less, preferably 200 μm or less.

The insulating layer 7 protects the wire 6 from corrosion by chemicals or water, and prevents short circuit between the wire 6 and the magnetic layer 3 . The insulating layer 7 covers the entire outer peripheral surface (circumferential surface) of the conductor 6 .

The insulating layer 7 has a substantially annular cross-sectional shape that shares a central axis (center C) with the wiring 2 .

Examples of materials for the insulating layer 7 include polyvinyl formal, polyester, polyester amide, polyamide (including nylon), polyamide, polyamide and polyurethane. Ester and other insulating resins. One type of these materials may be used alone, or two or more types may be used in combination.

The insulating layer 7 may be composed of a single layer or multiple layers.

The thickness R2 of the insulating layer 7 is substantially uniform in the radial direction of the wiring 2 at any position in the circumferential direction, for example, 1 μm or more, preferably 3 μm or more, and, for example, 100 μm or less, preferably 50 μm or less.

The ratio (R1/R2) of the radius R1 of the conductor 6 to the thickness R2 of the insulating layer 7 is, for example, 1 or more, preferably 10 or more, for example, 500 or less, preferably 100 or less.

The radius R of the wiring 2 (=radius R1 of the conductor 6 + thickness R2 of the insulating layer 7 ) is, for example, 25 μm or more, preferably 50 μm or more, and, for example, 2000 μm or less, preferably 200 μm or less.

Magnetic layer 3 increases the inductance of inductor 1 . The magnetic layer 3 covers the entire outer peripheral surface (circumferential surface) of the wiring 2 . Magnetic layer 3 forms the outer shape of inductor 1 . Specifically, the magnetic layer 3 has a rectangular shape extending in the plane direction (the first direction and the second direction). More specifically, the magnetic layer 3 has one surface and another surface facing each other in the thickness direction, and each of the one surface and the other surface of the magnetic layer 3 respectively forms one surface and the other surface of the inductor 1 .

The magnetic layer 3 contains anisotropic magnetic particles 8 and a binder 9 . Specifically, the material of the magnetic layer 3 is a magnetic composition containing anisotropic magnetic particles 8 and a binder 9 . Preferably, the magnetic layer 3 is a cured product of a thermosetting resin composition (a composition including anisotropic magnetic particles 8 and a thermosetting component described below).

Examples of the magnetic material constituting the anisotropic magnetic particles 8 include soft magnets and hard magnets. From the viewpoint of inductance, soft magnets are preferred.

Examples of the soft magnet include a single metal body containing one metal element in a pure material state, and, for example, one or more metal elements (first metal element) and one or more metal elements (second metal element), and/or The eutectic (mixture) of non-metallic elements (carbon, nitrogen, silicon, phosphorus, etc.) is the alloy body. These can be used alone or in combination.

Examples of the single metal body include a metal element composed of only one metal element (first metal element). As the first metal element, for example, iron (Fe), cobalt (Co), nickel (Ni) and other metal elements contained as the first metal element of the soft magnetic material can be appropriately selected.

Examples of the single metal body include a core containing only one metal element, and a surface layer containing an inorganic substance and/or an organic substance that modifies part or all of the surface of the core, for example, a core containing a first metal element. The form of an organic metal compound or an inorganic metal compound after decomposition (such as thermal decomposition). More specifically, examples of the latter form include iron powder (sometimes referred to as carbonyl iron powder) obtained by thermal decomposition of an organic iron compound (specifically, carbonyl iron) containing iron as the first metal element. Furthermore, the position at which the layer containing the inorganic substance and/or the organic substance is modified, which is a part containing only one metal element, is not limited to the surface as described above. In addition, the organic metal compound or inorganic metal compound that can obtain a single metal body is not particularly limited, and can be appropriately selected from known or commonly used organic metal compounds or inorganic metal compounds that can obtain a single metal body of a soft magnetic body.

An alloy system is a eutectic melt of more than one metallic element (the first metallic element) and more than one metallic element (the second metallic element) and/or non-metallic elements (carbon, nitrogen, silicon, phosphorus, etc.), as long as it is The alloy bodies that can be used as soft magnets are not particularly limited.

The first metal element is an essential element in the alloy body, and examples thereof include iron (Fe), cobalt (Co), nickel (Ni), and the like. Furthermore, if the first metal element is Fe, the alloy system is an Fe-based alloy. If the first metal element is Co, the alloy system is a Co-based alloy. If the first metal element is Ni, the alloy system is Ni series alloy.

The second metal element is an element (auxiliary component) contained in the alloy body and is compatible (eutectic) with the first metal element. Examples thereof include iron (Fe) (the first metal is other than Fe). element), cobalt (Co) (when the first metal element is an element other than Co), nickel (Ni) (when the first metal element is an element other than Ni), chromium (Cr), aluminum (Al), silicon (Si), copper (Cu), silver (Ag), manganese (Mn), calcium (Ca), barium (Ba), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), ruthenium (Ru), rhodium (Rh), zinc (Zn), gallium (Ga), indium (In), germanium (Ge), tin (Sn), lead (Pb), scandium (Sc), yttrium (Y), strontium (Sr) and various rare earth elements, etc. These can be used individually or in combination of 2 or more types.

The non-metallic element is an element (auxiliary component) contained in the alloy body and is compatible (eutectic) with the first metallic element. Examples thereof include boron (B), carbon (C), and nitrogen. (N), silicon (Si), phosphorus (P), sulfur (S), etc. These can be used individually or in combination of 2 or more types.

Examples of Fe-based alloys as alloy bodies include magnetic stainless steel (Fe-Cr-Al-Si alloy) (including electromagnetic stainless steel), iron-silicon-aluminum alloy (Fe-Si-Al alloy) (including super iron-silicon-aluminum alloy). ), Permalloy (Fe-Ni alloy), Fe-Ni-Mo alloy, Fe-Ni-Mo-Cu alloy, Fe-Ni-Co alloy, Fe-Cr alloy, Fe-Cr-Al alloy, Fe-Ni -Cr alloy, Fe-Ni-Cr-Si alloy, silicon copper (Fe-Cu-Si alloy), Fe-Si alloy, Fe-Si-B (-Cu-Nb) alloy, Fe-B-Si-Cr alloy , Fe-Si-Cr-Ni alloy, Fe-Si-Cr alloy, Fe-Si-Al-Ni-Cr alloy, Fe-Ni-Si-Co alloy, Fe-N alloy, Fe-C alloy, Fe-B Alloy, Fe-P alloy, ferrite (including stainless steel ferrite, Mn-Mg ferrite, Mn-Zn ferrite, Ni-Zn ferrite, Ni-Zn-Cu ferrite Oxygen, soft ferrites such as Cu-Zn ferrite, Cu-Mg-Zn ferrite, iron-cobalt alloy (Fe-Co alloy), Fe-Co-V alloy, Fe-based amorphous alloy, etc.

Examples of Co-based alloys that are alloy bodies include Co-Ta-Zr and cobalt (Co)-based amorphous alloys.

An example of the Ni-based alloy as an alloy body is a Ni-Cr alloy.

Among these soft magnets, from the viewpoint of magnetic properties, an alloy body is preferred, an Fe-based alloy is more preferred, and an iron-silicon-aluminum alloy (Fe-Si-Al alloy) is more preferred. Furthermore, as the soft magnet, a single metal body is preferably used, a single metal body containing an iron element in a pure material state is more preferably used, and simple iron or iron powder (carbonyl iron powder) is still more preferably used.

Examples of the shape of the anisotropic magnetic particles 8 include flat shapes (plate shapes), needle shapes, etc. from the viewpoint of anisotropy, and from the viewpoint of good relative magnetic permeability in the planar direction (two dimensions). A flat shape is preferred.

The flatness (flatness) of the flat anisotropic magnetic particles 8 is, for example, 8 or more, preferably 15 or more, and is, for example, 500 or less, preferably 450 or less. The oblateness is calculated, for example, as an aspect ratio obtained by dividing the average particle diameter (average length) of the anisotropic magnetic particles 8 (described below) by the average thickness of the anisotropic magnetic particles 8 .

The average particle diameter (average length) of the anisotropic magnetic particles 8 is, for example, 3.5 μm or more, preferably 10 μm or more, and, for example, 200 μm or less, preferably 150 μm or less. If the anisotropic magnetic particles 8 are flat, their average thickness is, for example, 0.1 μm or more, preferably 0.2 μm or more, and, for example, 3.0 μm or less, preferably 2.5 μm or less.

The binder 9 disperses the anisotropic magnetic particles 8 in the magnetic layer 3 . In addition, the adhesive 9 is dispersed in the magnetic layer 3 in a specific direction. Preferably, the adhesive 9 contains a cured product of a B-stage thermosetting component. In addition, the adhesive 9 will be described in detail in the description of the first magnetic sheet 51 , the second magnetic sheet 52 and the third magnetic sheet 53 in the following manufacturing method.

In the magnetic layer 3 , the anisotropic magnetic particles 8 are aligned and uniformly arranged in the adhesive 9 .

The magnetic layer 3 has a peripheral region 4 and an outer region 5 when viewed in cross section (when cut along the cross section in the first direction).

The peripheral area 4 is the peripheral area of the wiring 2 and is located around the wiring 2 so as to be in contact with the entire outer peripheral surface (circumferential surface) of the wiring 2 . The peripheral area 4 has a substantially annular cross-section that shares a central axis with the wiring 2 . More specifically, the peripheral region 4 is a region in the magnetic layer 3 located within a range from the center C of the wiring 2 to 1.5 times the radius R of the wiring 2 . That is, the peripheral region 4 is a region located in a range 0.5 times the radius R of the wiring 2 radially outward from the outer peripheral edge of the wiring 2 (the inner peripheral edge of the peripheral region 4 ).

The peripheral area 4 includes a first area 11 and a second area 12 .

Two first areas 11 are arranged in the peripheral area 4 at intervals in the circumferential direction. Specifically, the first region 11 includes a third region 13 and a fourth region 14 arranged at a distance from the third region 13 on the other side in the thickness direction.

The third region 13 covers at least the outer circumferential arc surface of the wiring 2 including one end edge E1 in the thickness direction, for example, at least covers the first semicircular arc including one end edge E1 in the thickness direction of the wiring 2 (connected to one side of the wiring 2 in the thickness direction). Part or all of a semicircular arc surface 23 of the two end edges E2 and E3 of the wiring 2 in the first direction. Preferably, the third region 13 covers a part of the first semicircular arc surface 23 of the wiring 2. More specifically, when projected in the radial direction, it is included in one semicircular arc surface of the wiring 2. On the other hand, it is not It overlaps the first-direction end edges E2 and E3 of the wiring 2 and is arranged inside the first-direction end edges E2 and E3.

Furthermore, one end edge E1 in the thickness direction of the wiring 2 is a first imaginary line L1 passing through the center C of the wiring 2 along the thickness direction and intersecting with the arc surface (first semi-circular arc surface 23) on one side of the thickness direction of the wiring 2. part.

In addition, both end edges E2 and E3 of the wiring 2 in the first direction are two portions where the third imaginary line L3 passing through the center C of the wiring 2 intersects with the circumferential surface of the wiring 2 along the first direction.

The fourth area 14 is arranged to face the third area 13 across the center C of the wiring 2 . The fourth region 14 at least covers the outer circumferential arc surface of the covered wiring 2 including the other end edge E4 in the thickness direction, such as the second semicircular arc including the other end edge E4 in the thickness direction of the covered wiring 2 (on the other side of the wiring 2 in the thickness direction). , a part of the other half arc surface 24 connecting the two end edges E2 and E3 in the first direction. Specifically, when projected in the radial direction, the fourth region 14 is included in the second semicircular arc surface 24 of the wiring 2. On the other hand, it does not overlap with the both ends E2 and E3 of the wiring 2 in the first direction, but is arranged on Inside the two ends E2 and E3 of the wiring 2 in the first direction.

The other end edge E4 in the thickness direction of the wiring 2 is a portion where the first imaginary line L1 passing through the center C of the wiring 2 intersects the second arc surface 24 along the thickness direction.

The angle α1 of the central angle C1 of the third region 13 and the angle α2 of the central angle C2 of the fourth region 14 are appropriately set according to the use and purpose respectively. Their total angle (α1 + α2) is, for example, less than 360°, preferably 270° or less, and for example, more than 180°, preferably 200° or more.

Specifically, the angle α1 of the central angle C1 of the third region 13 is, for example, 90° or more, preferably more than 90°, more preferably 120° or more, and for example, less than 180°, preferably 165° or less. Moreover, angle α1 is preferably an obtuse angle.

The angle α2 of the central angle C2 of the fourth region 14 is, for example, 15° or more and, for example, 60° or less, preferably 45° or less. Moreover, angle α2 is preferably an acute angle.

The angle α1 of the central angle C1 of the third region 13 is larger than the angle α2 of the central angle C2 of the fourth region 14, and the ratio thereof (angle α1/angle α2) exceeds 1, for example, preferably 1.5 or more, and is 3 or less, preferably 2 or less.

In the first region 11 , the anisotropic magnetic particles 8 are aligned along the circumferential direction of the wiring 2 .

In each of the third region 13 and the fourth region 14, the direction in which the relative magnetic permeability of the anisotropic magnetic particles 8 is higher (for example, if the anisotropic magnetic particles 8 have a flat shape, it is anisotropic magnetism). The surface direction of the particle 8) is approximately consistent with the circumferential direction. Specifically, the angle between the plane direction of the anisotropic magnetic particles 8 and the tangent to the circumferential surface of the anisotropic magnetic particles 8 facing the radially inner side is 15° or less, which is defined as anisotropic magnetism. Particles 8 are aligned in the circumferential direction.

The ratio of the number of anisotropic magnetic particles 8 aligned in the circumferential direction to the total number of anisotropic magnetic particles 8 included in the first region 11 is, for example, more than 50%, preferably more than 70%, more preferably more than 80%. . That is, the first region 11 may contain, for example, less than 50%, preferably 30% or less, and more preferably 20% or less of the anisotropic magnetic particles 8 that are not aligned in the circumferential direction.

The area ratio of the first area 11 (the total area of the third area 13 and the fourth area 14) relative to the entire surrounding area 4 is, for example, 40% or more, preferably 50% or more, more preferably 60% or more, and for example It is 90% or less, preferably 80% or less.

The relative magnetic permeability in the circumferential direction of the first region 11 is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and, for example, 500 or less. The relative magnetic permeability in the radial direction is, for example, 1 or more, preferably 5 or more, and is, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. Moreover, the ratio of the relative magnetic permeability in the circumferential direction to the radial direction (circumferential direction/radial direction) is, for example, 2 or more, preferably 5 or more, and, for example, 50 or less. If the relative magnetic permeability is within the above range, the inductance will be excellent.

The relative magnetic permeability can be measured, for example, by an impedance analyzer (manufactured by Agilent, "4291B") using a magnetic material test fixture.

The second region 12 is a circumferentially non-aligned region in which the anisotropic magnetic particles 8 are not aligned along the circumferential direction of the wiring 2 . In other words, in the second region 12 , the anisotropic magnetic particles 8 are aligned or not aligned along a direction other than the circumferential direction of the wiring 2 (for example, the first direction or the radial direction).

Two second areas 12 are arranged in the peripheral area 4 at intervals in the circumferential direction. Specifically, the second region 12 includes a fifth region 15 and a sixth region 16 that are equally spaced from each other across the first imaginary straight line L1 passing through one end edge E1 and the other end edge E2 of the wiring 2 in the thickness direction.

The fifth region 15 is arranged on the first direction side with respect to the first virtual straight line L1. The fifth region 15 is sandwiched between one circumferential end face of the third region 13 and the other circumferential end face of the fourth region 14. Specifically, it is continuous between one circumferential end face of the third region 13 and the fourth region 14. The other end face in the circumferential direction.

The sixth region 16 is arranged opposite to the fifth region 15 at a distance from the fifth region 15 on the other side in the first direction. The sixth region 16 is arranged on the other side in the first direction with respect to the first virtual straight line L1 and is linearly symmetrical with respect to the fifth region 15 with the first virtual straight line L1 as an axis. That is, the sixth region 16 is continuous with the other end surface of the third region 13 in the circumferential direction and the one end surface of the fourth region 14 in the circumferential direction.

Thereby, in the first area 11, the third area 13, the fifth area 15, the fourth area 14, and the sixth area 16 are sequentially arranged in the circumferential direction.

Furthermore, on the second virtual straight line L2 which is an example of a virtual straight line and connects the center C3 of the first virtual arc A1 which is an example of the virtual arc and the center C4 of the second virtual arc A2 which is an example of the virtual arc. , there is no center C of the wiring 2, and the above-mentioned first imaginary arc A1 connects the first end E5 as one end in the circumferential direction and the second end E6 as the other end in the circumferential direction in the fifth area 15. The above-mentioned second imaginary arc A1 A2 connects the third end E7 as one end in the circumferential direction and the fourth end E8 as the other end in the circumferential direction in the sixth area 16 .

Furthermore, the first end E5 is a portion of the fifth region 15 located at the radial center of one end surface in the circumferential direction. The second end E6 is a portion of the fifth region 15 located at the radial center of the other end surface in the circumferential direction. The third end E7 is a portion of the sixth region 16 located at the radial center of one end surface in the circumferential direction. The fourth end E8 is a portion of the sixth region 16 located at the radial center of the other end surface in the circumferential direction.

Specifically, the center C of the wiring 2 is arranged on the first direction side of the second virtual straight line L2 with a gap therebetween.

Specifically, the center C of the wiring 2 is located on one side in the thickness direction at a distance from 0.2 times to 0.7 times the radius R of the wiring 2 relative to the second imaginary straight line L2. Preferably, it is The virtual straight line L2 is located on one side in the thickness direction at a distance from 0.3 times to 0.5 times the radius R of the wiring 2 .

In addition, the other end edge E4 in the thickness direction of the wiring 2 does not exist on the second virtual straight line L2. Specifically, it is located on the other side in the thickness direction of the second virtual straight line L2 with a gap therebetween.

Furthermore, in the second region 12 (each of the fifth region 15 and the sixth region 16), an intersection portion (top portion) 20 is formed by at least two types of anisotropic magnetic particles 8 with different alignment directions. For example, in the fifth region 15, the first particle 17 and the second particle 18 form at least two sides of a substantially triangle, thereby forming a first intersection (first top) 21, and the first particle 17 follows from the first 1. The anisotropic magnetic particles 8 are aligned toward the radially outer side of the wiring 2 at the end E5 (the portion in contact with the third region 13) toward the second end E6 (the portion in contact with the fourth region 14). The two particles 18 are anisotropic magnetic particles 8 aligned in the first direction as they move from the second end E6 toward the first end E5. Specifically, the first particle 17, the second particle 18, and the third particle 19 form a substantially triangle (preferably an acute triangle), and the third particle 19 is along the circumference of the area in the fifth area 15 where the wiring 2 is closest. Directionally aligned anisotropic magnetic particles 8.

Furthermore, in the sixth region 16, the first particles 17 and the second particles 18 form at least two sides of a substantially triangle, thereby forming a second intersection (second top) 22. The first particles 17 follow from the first particle 17 The anisotropic magnetic particles 8 are aligned toward the radially outer side of the wiring 2 at the fourth end E8 (the portion that is in contact with the third region 13) and toward the third end E7 (the portion that is in contact with the fourth region 14). The particles 18 are anisotropic magnetic particles 8 aligned in the first direction as they move from the third end E7 toward the fourth end E8. Specifically, the first particle 17, the second particle 18, and the third particle 19 form a substantially triangle (preferably an acute triangle), and the third particle 19 is along the circumference of the area in the sixth area 16 where the wiring 2 is closest. Directionally aligned anisotropic magnetic particles 8.

When projected in the first direction, the intersection portion 20 (each of the first intersection portion 21 and the second intersection portion 22 ) does not overlap with the center C of the wiring 2 . Specifically, when projected in the first direction, the intersection portion 20 is disposed at intervals on the other side in the thickness direction from the center C of the wiring 2 .

In addition, when projected in the first direction, the intersection portion 20 is arranged at a distance from the other end edge E4 in the thickness direction of the wiring 2 on one side in the thickness direction.

In the second region 12 (each of the fifth region 15 and the sixth region 16), the direction in which the relative magnetic permeability of the anisotropic magnetic particles 8 is higher (for example, for flat anisotropic magnetic particles, is The surface direction of the particle) does not coincide with the tangent to the circumferential surface centered on the center C of the wiring 2. More specifically, an angle exceeding 15 degrees between the plane direction of the anisotropic magnetic particles 8 and the outer peripheral surface (circumferential surface) of the wiring 2 where the anisotropic magnetic particles 8 is located is defined as anisotropic magnetism. Particles 8 are not aligned in the circumferential direction.

The ratio of the number of anisotropic magnetic particles 8 that are not aligned in the circumferential direction to the total number of anisotropic magnetic particles 8 included in the second region 12 is, for example, more than 50%, preferably more than 70%, and for example, 95%. below, preferably below 90%.

The second region 12 may include, for example, anisotropic magnetic particles 8 aligned in the circumferential direction. The ratio of the number of anisotropic magnetic particles 8 aligned in the circumferential direction to the total number of anisotropic magnetic particles 8 included in the second region 12 is, for example, less than 50%, preferably less than 30%, and for example, 5 % or more, preferably 10% or more.

Furthermore, when the anisotropic magnetic particles 8 aligned in the circumferential direction are included, it is preferable that the anisotropic magnetic particles 8 aligned in the circumferential direction are arranged in the innermost area of the second area 12, that is, between the wiring 2 near the surface.

The area ratio of the second area 12 (the total area of the fifth area 15 and the sixth area 16) relative to the entire peripheral area 4 is, for example, 10% or more, preferably 20% or more, and, for example, 60% or less, preferably 50% or less, preferably 40% or less.

Furthermore, the filling ratio (presence ratio) of the anisotropic magnetic particles 8 in the peripheral region 4 is, for example, 40 volume % or more, preferably 45 volume % or more, more preferably 50 volume % or more, and further preferably 55 volume % or more. % or more, particularly preferably more than 60 volume %. If the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 is equal to or higher than the above-mentioned lower limit, the inductor 1 can obtain excellent inductance.

Moreover, the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 is, for example, 95 volume % or less, preferably 90 volume % or less. If the filling rate of the anisotropic magnetic particles 8 is equal to or less than the above upper limit, the inductor 1 will have excellent mechanical strength.

In particular, the filling rate of the anisotropic magnetic particles 8 in each of the first region 11 and the second region 12 is, for example, 40 volume % or more, preferably 45 volume % or more, and more preferably 50 volume % or more. Furthermore, it is preferably 55 volume % or more, particularly preferably 60 volume % or more, and for example, it is 95 volume % or less, preferably 90 volume % or less.

Furthermore, the filling rate of the anisotropic magnetic particles 8 in the first region 11 and the filling rate of the anisotropic magnetic particles 8 in the second region 12 may be the same or different.

The filling rate of the anisotropic magnetic particles 8 can be calculated by actual specific gravity measurement, binarization of SEM photographs, and the like.

On the other hand, the presence ratio of the binder 9 in the peripheral region 4 is, for example, the remainder of the above-mentioned filling ratio of the anisotropic magnetic particles 8 .

In addition, in the peripheral area 4 , the formation of voids (voids, gaps) is suppressed as much as possible, and it is preferable that there are no voids between the wiring 2 and the magnetic layer 3 . That is, the peripheral region 4 is preferably void-free.

The outer region 5 is a region of the magnetic layer 3 other than the peripheral region 4 . The outer area 5 is arranged outside the peripheral area 4 and continues with the peripheral area 4 .

In the outer region 5, the anisotropic magnetic particles 8 are aligned along the plane direction (especially the first direction).

In the outer region 5 , the direction in which the relative magnetic permeability of the anisotropic magnetic particles 8 is high (for example, in the case of flat anisotropic magnetic particles, the plane direction of the particles) is substantially consistent with the first direction. More specifically, it is defined that the anisotropic magnetic particles 8 are aligned in the first direction when the angle between the plane direction of the anisotropic magnetic particles 8 and the first direction is 15° or less.

In the outer region 5 , the ratio of the number of anisotropic magnetic particles 8 aligned in the first direction to the total number of anisotropic magnetic particles 8 included in the outer region 5 exceeds 50%, preferably more than 70%. , preferably more than 90%. That is, the outer region 5 may contain less than 50%, preferably 30% or less, more preferably 10% or less of the anisotropic magnetic particles 8 that are not aligned in the first direction.

In addition, the filling rate of the anisotropic magnetic particles 8 in the outer region 5 may be the same as or different from the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 .

In the outer region 5 , the relative magnetic permeability in the first direction is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and, for example, 500 or less. The relative magnetic permeability in the thickness direction is, for example, 1 or more, preferably 5 or more, and, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. Moreover, the ratio of the relative magnetic permeability in the first direction to the thickness direction (first direction/thickness direction) is, for example, 2 or more, preferably 5 or more, and, for example, 50 or less.

In the outer region 5, the filling rate of the anisotropic magnetic particles 8 is not particularly limited. For example, it is 40 volume % or more, preferably 45 volume % or more, more preferably 50 volume % or more, and still more preferably 55 volume %. above. Particularly preferably, it is 60 volume % or more, and for example, it is 95 volume % or less, More preferably, it is 90 volume % or less.

The thickness of the magnetic layer 3 is, for example, 2 times or more, preferably 3 times or more, and, for example, 20 times or less of the radius R of the wiring 2 . Specifically, the thickness of the magnetic layer 3 is, for example, 100 μm or more, preferably 200 μm or more, and, for example, 2000 μm or less, preferably 1000 μm or less. Furthermore, the thickness of the magnetic layer 3 is the distance between one surface of the magnetic layer 3 and the other surface.

2. Manufacturing method of inductor The manufacturing method of the inductor 1 will be described with reference to FIGS. 2A to 3F.

The manufacturing method of the inductor 1 includes the first to sixth steps. In the manufacturing method of the inductor 1, the first step, the second step and the third step are carried out in sequence, and then the fourth step, the fifth step and the sixth step are carried out simultaneously.

(Step 1) As shown in FIG. 2A , in the first step, first, the wiring 2 and the first release sheet 41 as a release film are prepared. The first release sheet 41 is an example of a substrate.

The first release sheet 41 has a general sheet shape extending in the surface direction. The material of the first release sheet 41 is appropriately selected according to its use and purpose. Specific examples include polyesters such as polyethylene terephthalate (PET), polymethylpentene, and polypropylene. Polyolefins, etc. In addition, one surface and/or the other surface in the thickness direction of the first release sheet 41 may be subjected to a release treatment. The thickness of the first release sheet 41 is, for example, 1 μm or more, and is, for example, 1000 μm or less.

Thereafter, in the first step, the wiring 2 and the first release sheet 41 are placed on the flat plate press 42 .

The flat plate press 42 is provided with the 1st plate 43 and the 2nd plate 44 which can pressurize in the thickness direction. In the flat plate press 42, the second plate 44 is arranged to face one side of the first plate 43 in the thickness direction with a gap therebetween. Furthermore, the flat plate press 42 is equipped with a heat source not shown in the figure.

Furthermore, the flat plate press 42 is provided with a chamber for placing the components provided in the flat plate press 42 and supplied to the press in a vacuum state.

In the first step, first, the first release sheet 41 is arranged on the first plate 43 , and then, the wiring 2 is arranged on one surface of the first release sheet 41 in the thickness direction. Specifically, the other end edge E4 in the thickness direction of the wiring 2 is brought into contact with one surface of the first release sheet 41 .

Furthermore, at this time, the first release sheet 41 and the first plate 43 are arranged in the chamber. Each component configured in the subsequent steps is arranged in the chamber.

(Step 2) In the second step, first, as shown in FIG. 2A , the first magnetic sheet 51 is prepared. At the same time, the second release sheet 45 and the release buffer sheet 46 are prepared.

[1st magnetic sheet] The first magnetic sheet 51 has a general sheet shape extending in the plane direction. Specifically, the first magnetic sheet 51 has one surface and another surface facing each other in the thickness direction.

The first magnetic sheet 51 is a magnetic sheet used to form at least (part or all) of the second region 12 and the third region 13 in the magnetic layer 3 , and a part of the outer region 5 .

Furthermore, the first magnetic sheet 5 is configured to be deformed (flow) by hot pressing in the second step (see FIG. 2B ).

Furthermore, the first magnetic sheet 51 contains first anisotropic magnetic particles 81 and a first adhesive 91 as an example of the first magnetic particles. The first anisotropic magnetic particles 81 are the same as the anisotropic magnetic particles 8 . Specifically, the first magnetic sheet 51 is formed into a substantially sheet shape from the first magnetic composition containing the first anisotropic magnetic particles 81 and the first binder 91 .

In the first magnetic sheet 51, the first anisotropic magnetic particles 81 are uniformly dispersed by the first adhesive 91 so as to be aligned in the plane direction.

The first magnetic sheet 51 is a single sheet or a laminated body (laminated sheet) of a plurality of sheets, preferably a laminated sheet, more preferably a two-layer sheet including the inner sheet 54 and the outer sheet 55 , the inner sheet 54 is in contact with the wiring 2 during hot pressing, and the outer sheet 55 is arranged on one side in the thickness direction of the inner sheet.

The volume ratio of the first anisotropic magnetic particles 81 in the first magnetic composition (first magnetic sheet 51) is, for example, 40 volume % or more, preferably 45 volume % or more, more preferably 50 volume % or more, and further It is preferably 55 volume % or more, particularly preferably 60 volume % or more, and for example, it is 95 volume % or less, preferably 90 volume % or less. If the volume ratio of the first anisotropic magnetic particles 81 is within the above range, the first anisotropic magnetic particles 81 can be densely arranged in the peripheral area 4 . Thereby, an inductor 1 having excellent inductance can be obtained.

Moreover, the volume ratio of the first anisotropic magnetic particles 81 in the first magnetic composition (first magnetic sheet 51) is also preferably, for example, 40 volume % or less, further 35 volume % or less, and 20 volume % or more. , and further more than 25% by volume. If the volume ratio of the first anisotropic magnetic particles 81 is within the above range, the existence of pores in the peripheral area 4 can be suppressed as much as possible. Therefore, the first anisotropic magnetic particles 81 and the first anisotropic magnetic particles 81 can be combined in the peripheral area 4 The second anisotropic magnetic particles 82 and the third anisotropic magnetic particles 83 (described below) are densely arranged together. As a result, the inductor 1 having excellent inductance can be obtained.

If the first magnetic sheet 51 is a two-layer laminated sheet of the inner sheet 54 and the outer sheet 55, the volume ratio of the anisotropic magnetic particles 8 in the outer sheet 55 is preferably higher than the volume of the inner sheet 54. ratio. In this way, the first magnetic sheet 51 can more flexibly follow the area of the circumferential surface of the wiring 2 that exceeds 180° in cross-section (hereinafter referred to as a major arc).

Examples of the first adhesive 91 include thermoplastic components such as acrylic resins and thermosetting components such as epoxy resin compositions. The acrylic resin includes, for example, a carboxyl group-containing acrylate copolymer. The epoxy resin composition contains, for example, an epoxy resin as a main ingredient (for example, a cresol novolac type epoxy resin, etc.), a hardener for the epoxy resin (for example, a phenolic resin, etc.), and a hardening accelerator for the epoxy resin ( For example, imidazole compounds, etc.).

As the first adhesive 91, a thermoplastic component and a thermosetting component can be used alone or in combination. It is preferable to use a combination of a thermoplastic component and a thermosetting component.

That is, it is preferable that the first adhesive 91 contains at least a thermosetting component. If the first adhesive 91 contains at least a thermosetting component, the first magnetic sheet 51 can be brought into the B-stage with fluidity, allowing the first anisotropic magnetic particles 81 to be uniformly dispersed at a higher mixing ratio. Moreover, during the hot pressing in the second step, the first magnetic sheet 51 can be flexibly deformed and follow and cover the superior arc on the circumferential surface of the wiring 2 .

Furthermore, a more detailed formula of the first adhesive 91 (first magnetic composition) is described in Japanese Patent Application Laid-Open No. 2014-165363 and the like.

The volume ratio of the first adhesive 91 in the first magnetic composition (first magnetic sheet 51 ) is the remainder of the volume ratio of the magnetic particles 48 .

In order to prepare the first magnetic sheet 51, the first anisotropic magnetic particles 81 and the first binder 91 are prepared and uniformly mixed to prepare the first magnetic composition. At this time, a solvent (organic solvent) will be used as necessary to prepare the varnish of the first magnetic composition. Thereafter, varnish is applied to a release film (not shown) and dried to produce the first magnetic sheet 51 .

The thickness of the first magnetic sheet 51 (or the total thickness in the case of a laminated sheet) is appropriately set to maintain a shape that can cover at least one end edge E1 in the thickness direction of the wiring 2 in the outer region 5 by the heat pressing in the second step. . Specifically, the thickness of the first magnetic sheet 51 is, for example, 3 times or less of the radius R of the wiring 2, preferably 2 times or less, more preferably less than 2 times, further preferably 1.5 times or less, and particularly preferably 1.25 times or less, and for example, 0.1 times or more, preferably 0.2 times or more.

(Second release sheet) The second release sheet 45 has the same structure as the first release sheet 41. As can be seen from the above, its material is appropriately selected according to the use and purpose.

(Release buffer sheet) The release buffer sheet 46 is a release sheet that can separate the first magnetic sheet 51 from the second plate 44 after hot pressing (see FIG. 2C ) in the second step described later. In addition, the release buffer sheet 46 is also a buffer sheet used to ensure that the pressure of the second plate 44 corresponds to the circumferential surface of the wiring 2 during the hot pressing in the second step (see FIG. 2B ). The shape of the arc acts on the first magnetic sheet 51 in a dispersed manner, deforming the first magnetic sheet 51 so that the first magnetic sheet 51 follows the superior arc of the circumferential surface of the wiring 2 .

The release buffer sheet 46 has a sheet shape extending in the surface direction, and has one surface and another surface in the thickness direction.

One surface of the release buffer sheet 46 may be in surface contact with the second plate 44 (described below) in the second step. One surface of the release buffer sheet 46 is a flat surface along the surface direction.

The other surface of the release buffer sheet 46 can contact one surface in the thickness direction of the second release sheet 45 to deform the first magnetic sheet 51 . The other surface of the release buffer sheet 46 is spaced apart from the first surface and is disposed opposite to the other side in the thickness direction. The other surface of the release buffer sheet 46 is a flat surface parallel to one surface and along the surface direction.

The release buffer sheet 46 has a first layer 47, a second layer 48, and a third layer 49 in order on one side in the thickness direction.

(Tier 1) The first layer 47 is a release layer (first release layer) for the first magnetic sheet 51 . The first layer 47 is a thin film (film) having a shape extending in the plane direction. In addition, the first layer 47 is a coating layer (outer shell layer) covering the second layer 48 described later from the other side in the thickness direction. An appropriate peeling process may be performed on the other surface of the first layer 47 in the thickness direction.

The first layer 47 has the following physical properties: in the subsequent hot pressing step of the second step, it can follow one surface of the first magnetic sheet 51 through the second release sheet 45. On the other hand, its thickness is different from that of the hot pressing process. Substantial changes before and after. In addition, the first layer 47 is a layer that can be stretched in the plane direction (specifically, the first direction) during hot pressing. Furthermore, the first layer 47 is harder than the second layer 48 described later at the hot pressing temperature (for example, 110° C.) in the second step.

Examples of the material of the first layer 47 include a non-thermal flow material that is prevented from flowing in at least the first direction by hot pressing in the second step described below.

The non-thermal flow material contains aromatic polyester such as polybutylene terephthalate (PBT) and polyolefin as main components.

(Tier 2) The second layer 48 is an intermediate layer sandwiched between the first layer 47 and the third layer 49. The second layer 48 is a fluid layer, which flows in the first direction and the thickness direction during the hot pressing in the first step, so that the first layer 47 follows the surface of the first magnetic sheet 51 .

The second layer 48 is a soft layer that is softer than the first layer 47. Specifically, it can be deformed during the hot pressing in the second step. Specifically, the tensile storage modulus E' of the second layer 48 at 110°C is, for example, lower than the tensile storage modulus E' of the first layer 47 at 110°C.

Examples of the material of the second layer 48 include a heat flow material that flows in the first direction and the thickness direction by hot pressing in the second step described below. The heat flow material contains, for example, an olefin-(meth)acrylate copolymer (ethylene-(meth)methyl acrylate copolymer, etc.), an olefin-vinyl acetate copolymer, or the like as a main component.

(Tier 3) The third layer 49 is a release layer (second release layer) for the second plate 44 . The shape, physical properties, material and thickness of the third layer 49 are the same as the shape, physical properties, material and thickness of the first layer 47 .

(Thickness of release buffer sheet) The thickness of the release buffer sheet 46 is, for example, 50 μm or more, and is, for example, 500 μm or less. In addition, the thickness of the first layer 47 and the third layer 49 is, for example, 5 μm or more and 50 μm or less, respectively, and the thickness of the second layer 48 is, for example, 30 μm or more and 300 μm or less. The ratio of the thickness of the second layer 48 to the thickness of the first layer 47 is, for example, 2 or more, preferably 5 or more, more preferably 7 or more, and, for example, 15 or less.

Commercially available products can be used as the release buffer sheet 46. For example, release film OT-A, release film OT-E, release film OT series (manufactured by Sekisui Chemical Industry Co., Ltd.), etc. can be used.

Then, the first release sheet 41 , the wiring 2 , the first magnetic sheet 51 , the second release sheet 45 and the release buffer sheet 46 are sequentially clamped by the flat plate press 42 .

Then, the wiring 2 and the first magnetic sheet 51 are hot-pressed using the flat plate press 42 with the first release sheet 41 , the second release sheet 45 and the release buffer sheet 46 interposed therebetween.

For example, the second plate 44 is moved close to the first plate 43, and the second plate 44 is pressed (pressurized) against the first magnetic sheet 51 through the isolation buffer sheet 46 and the second release sheet 45. .

At the same time, the first magnetic sheet 51 and the release buffer sheet 46 are heated by a heat source.

The pressurizing pressure is, for example, 0.1 MPa or more, preferably 0.3 MPa or more, and, for example, 10 MPa or less, preferably 5 MPa or less.

Specifically, the heating temperature is, for example, 100°C or higher, preferably 105°C or higher, and, for example, 190°C or lower, preferably 150°C or lower.

The pressurizing time is, for example, 10 seconds or more, preferably 20 seconds or more, and, for example, 1000 seconds or less, preferably 100 seconds or less.

In the second step, the second plate 44 moves relative to the first plate 43 to seal the chamber, and then make the environment in the chamber a vacuum state. Then, the first plate 43 and the first release sheet 41. The wiring 2, the first magnetic sheet 51, the second release sheet 45, the release buffer sheet 46 and the second plate 44 should be in contact with each other (close contact, close contact) with each other in the thickness direction, and then , the second plate 44 moves further (hot pressing starts).

Therefore, when projected in the thickness direction, the overlapping portion 34 of the release buffer sheet 46 that overlaps the wiring 2 is narrowed in the thickness direction due to the first semicircular arc surface 23 and the second plate 44 of the wiring 2. Extrusion (clamping).

On the other hand, when projected in the thickness direction, the non-overlapping portion 35 of the release buffer sheet 46 that does not overlap the wiring 2 will not be pinched as described above.

Then, the thermal fluid material in the overlapping portion 34 of the second layer 48 flows (extrudes) (deforms) toward the non-overlapping portion 35 (more specifically, plastic deformation). Then, in the non-overlapping portion 35 , the flow pressure based on the flow (extrusion) of the hot fluid material from the overlapping portion 34 increases. The flow pressure of the non-overlapping portion 35 acts on both sides in the thickness direction.

Among the flow pressures, the flow pressure acting on the other side in the thickness direction extrudes (presses down) the first layer 47 of the non-overlapping portion 35 toward the other side in the thickness direction, and separates the first layer 47 from the first magnetic sheet. The extruded portion 38 of the material 51 that is opposite to the non-overlapping portion 35 in the thickness direction is extruded (pressed) toward the other side in the thickness direction.

Thereafter, the extrusion (pressing down) of the extruded portion 38 generated by the above-mentioned flow pressure continues until the extruded portion 38 wraps the two end edges E3 and E4 of the wiring 2 in the first direction, and then covers (contacts) the wiring 2 to the second arc surface 24 (except for the other end edge E4 in the thickness direction).

Then, as the extruded portion 38 comes into contact with the second arc surface 24, as shown in FIG. 2B, the second region 12 is formed.

After hot pressing, the other surface of the release buffer sheet 46 has, for example, a shape corresponding to the first semicircular arc surface 23 of the wiring 2 .

The second release sheet 45 follows the other surface of the release buffer sheet 46, specifically the first layer 47.

Furthermore, the first magnetic sheet 51 after hot pressing is in the B stage, for example. Specifically, the thermosetting component contained in the first adhesive 91 of the first magnetic sheet 51 is the B stage.

Thereby, the hot-pressed first magnetic sheet 51 has a shape including at least the second region 12 . That is, as shown in the enlarged view of FIG. 2B , in the second region 12 , the anisotropic magnetic particles 8 are not aligned along the circumferential direction of the wiring 2 .

Furthermore, the first magnetic sheet 51 has a raised portion 25 and a flat portion 26 .

The raised portion 25 covers the outer peripheral surface of the wiring 2 (except for the other end edge E4 in the thickness direction), and has a cross-sectional curved shape similar (or similar) to the first semicircular arc surface 23 . The raised portion 25 has a shape in which the center in the first direction protrudes (raised) toward one side in the thickness direction. The raised portion 25 has a second top portion 27 .

The flat portion 26 has a substantially flat plate shape extending from both end surfaces of the raised portion 25 in the first direction toward both outer sides in the first direction.

Thereby, the first magnetic sheet 51 is disposed on one surface of the first release sheet 41 in the thickness direction in a superior arc covering the circumferential surface of the wiring 2 .

The superior arc of the circumferential surface of the wiring 2 is an arc from the first semicircular arc surface 23 and each of its two ends in the circumferential direction toward the other end edge E4 in the thickness direction along the circumferential direction, but does not reach the other end edge E4 in the thickness direction. surface (part of the circumferential surface).

The thickness of the first magnetic sheet 51 after hot pressing is set so as to ensure the shape of the above-mentioned raised portion 25 and flat portion 26 . Specifically, the ratio of the thickness of the second top 27 of the first magnetic sheet 51 to the radius R of the wiring 2 is, for example, 0.01 or more, preferably 0.03 or more, and, for example, 8 or less, preferably 2 or less. The ratio of the thickness of the flat portion 26 to the radius R of the wiring 2 is, for example, 0.05 or more, preferably 0.2 or more, and is, for example, less than 5, and preferably 1.5 or less.

Specifically, the thickness of the second top 27 of the first magnetic sheet 51 is, for example, 1 μm or more, preferably 5 μm or more, and, for example, 200 μm or less, preferably 100 μm or less. In addition, the thickness of the flat portion 26 is, for example, 25 μm or more, preferably 50 μm or more, and, for example, 200 μm or less, preferably 150 μm or less.

(Step 3) In the third step, first, the pressure of the flat plate press 42 shown in FIG. 2B is released, and then, the first release sheet 41, the wiring 2, the first magnetic sheet 51, and the like are taken out from the flat plate press 42. The second release sheet 45 and the release buffer sheet 46 .

Next, as shown in FIG. 2C , the first release sheet 41 is peeled off from the other surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2 .

Furthermore, the second release sheet 45 and the release buffer sheet 46 are peeled off from one surface of the first magnetic sheet 51 .

(Step 4, Step 5 and Step 6) As shown in Figure 3E, steps 4, 5 and 6 are performed simultaneously.

In the fourth step, one surface of the first magnetic sheet 51 in the thickness direction is covered with the second magnetic sheet 52 . In the fifth step, the other surface of the first magnetic sheet 51 in the thickness direction is covered with the third magnetic sheet 53 . In the sixth step, the thermosetting components of the first adhesive 91 (refer to FIG. 2A), the second adhesive 92 (refer to FIG. 3D), and the third adhesive 93 (refer to FIG. 3D) are staged.

As shown in FIG. 3D , in the fourth step and the fifth step, first, the second magnetic sheet 52 and the third magnetic sheet 53 are prepared.

Each of the second magnetic sheet 52 and the third magnetic sheet 53 may have the same structure as the first magnetic sheet 51 .

Furthermore, the second magnetic sheet 52 contains second anisotropic magnetic particles 82 and a second adhesive 92. In the second adhesive 92, for example, the second anisotropic magnetic particles 82 are aligned in the plane direction. The thermosetting component contained in the second adhesive 92 is the B-stage, so the second magnetic sheet 52 is the B-stage. Moreover, if the second magnetic sheet 52 is a laminated body (laminated sheet), the presence ratio of the second anisotropic magnetic particles 82 in each sheet is the same or different, preferably the same. Furthermore, the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 may be the same as or different from the presence ratio of the first anisotropic magnetic particles 81 .

When the presence ratio of the second anisotropic magnetic particles 82 is different from the presence ratio of the first anisotropic magnetic particles 81, and the presence ratio of the first anisotropic magnetic particles 81 is 40% by volume or less, the second anisotropic magnetic particles 81 may be The existence ratio of the anisotropic magnetic particles 82 is set to be higher than the existence ratio of the first anisotropic magnetic particles 81 . Specifically, the ratio of the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 to the presence ratio of the first anisotropic magnetic particles 81 in the first magnetic sheet 51 (second magnetic sheet The ratio of the presence of the second anisotropic magnetic particles 82 in the material 52/the ratio of the presence of the first anisotropic magnetic particles 81 in the first magnetic sheet 51) is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more, and for example, 3 or less, preferably 2.5 or less. In this case, specifically, the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 is, for example, 45 volume % or more, preferably 50 volume % or more, and more preferably 55 volume % or more. , further preferably 60 volume % or more, and for example, 95 volume % or less, preferably 90 volume % or less.

If the above-mentioned ratio and/or the presence ratio of the second anisotropic magnetic particles 82 is within the above-mentioned range, the presence of voids between the second magnetic sheet 52 and the first magnetic sheet 51 can be suppressed as much as possible. Therefore, the first anisotropic magnetic particles 81 and the second anisotropic magnetic particles 82 can be densely arranged in the peripheral area 4 . As a result, the inductor 1 having excellent inductance can be obtained.

The thickness of the second magnetic sheet 52 (total thickness in the case of a laminated sheet) is, for example, 0.5 times or more, preferably 1 time or more, more preferably 1.5 times or more, and, for example, 5 times the radius R of the wiring 2 or less, preferably 3 times or less.

The third magnetic sheet 53 contains third anisotropic magnetic particles 83 as an example of the third magnetic particles and a third adhesive 93. For example, in the third adhesive 93, the third anisotropic magnetic particles 83 are on the surface. Alignment in direction. The thermosetting component contained in the third adhesive 93 is the B-stage, so the third magnetic sheet 53 is the B-stage. Moreover, if the third magnetic sheet 53 is a laminated body (laminated sheet), the presence ratio of each sheet and the third anisotropic magnetic particles 83 is the same or different, preferably the same. Furthermore, the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 may be the same as or different from the presence ratio of the first anisotropic magnetic particles 81 .

When the presence ratio of the third anisotropic magnetic particles 83 is different from the presence ratio of the first anisotropic magnetic particles 81, and the presence ratio of the first anisotropic magnetic particles 81 is 40% by volume or less, the third anisotropic magnetic particles 83 are The presence ratio of the anisotropic magnetic particles 83 is set to be higher than the presence ratio of the first anisotropic magnetic particles 81 . Specifically, the ratio of the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 to the presence ratio of the first anisotropic magnetic particles 81 in the first magnetic sheet 51 (third magnetic sheet The ratio of the presence of the third isotropic magnetic particles 83 in the material 53/the ratio of the presence of the first anisotropic magnetic particles 81 in the first magnetic sheet 51) is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more, and for example, 2.5 or less, preferably 2 or less. In this case, specifically, the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 is, for example, 40 volume % or more, preferably 45 volume % or more, and more preferably 50 volume % or more. , further preferably 55 volume % or more, particularly preferably 60 volume % or more, and for example, 95 volume % or less, preferably 90 volume % or less.

If the above-mentioned ratio and/or the presence ratio of the third anisotropic magnetic particles 83 is within the above-mentioned range, the existence of voids between the third magnetic sheet 53 and the first magnetic sheet 51 can be suppressed as much as possible, and as a result, it is possible to The first anisotropic magnetic particles 81 and the third anisotropic magnetic particles 83 are densely arranged in the peripheral area 4 . Therefore, the inductor 1 having excellent inductance can be obtained.

The thickness of the third magnetic sheet 53 (total thickness in the case of a laminated sheet) is, for example, 0.5 times or more, preferably 1 time or more, and, for example, 5 times or less, preferably 3 times, the radius R of the wiring 2 the following.

Subsequently, the second magnetic sheet 52 and the third magnetic sheet 53 are placed on the flat plate press 42 . Specifically, between the first plate 43 and the second plate 44, the first release sheet 41, the third magnetic sheet 53, the wiring 2 and the first magnetic sheet 51 are arranged in order toward the thickness direction side. The second magnetic sheet 52 and the second release sheet 45 .

Furthermore, the first release sheet 41 and/or the second release sheet 45 can reuse the first release sheet 41 and/or the second release sheet 45 removed in the above third step, and also Other first release sheets 41 and/or second release sheets 45 may be prepared and arranged.

Furthermore, in the hot pressing of the fourth and fifth steps, the release buffer sheet 46 used in the second step is not placed on the flat plate press 42 .

Subsequently, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, and the second magnetic sheet 52 are hot-pressed using a flat plate press. The conditions for hot pressing are the same as those in step 2.

The other surface of the second magnetic sheet 52 follows the shape of the raised portion 25 of the first magnetic sheet 51 by hot pressing. However, one surface of the second magnetic sheet 52 maintains its flat shape.

That is, the second magnetic sheet 52 covers one surface of the first magnetic sheet 51 in the thickness direction, and the first magnetic sheet 51 covers the superior arc of the circumferential surface of the wiring 2 and one surface of the first release sheet 41 (implementation Step 4).

In addition, the other surface of the third magnetic sheet 53 maintains its flat shape by hot pressing.

On the other hand, on one surface of the third magnetic sheet 53, the facing portion 28 facing the other end edge E4 in the thickness direction of the wiring 2 moves slightly (retreats, falls, sinks) toward the other side in the thickness direction. That is, on one surface of the third magnetic sheet 53, the facing portion 28 moves outward in the first direction, and moves toward the thickness direction with respect to the second flat portion 29 parallel to one surface of the first release sheet 41. Slightly concave on one side.

The other surface of the first magnetic sheet 51 is in close contact with the second flat portion 29 of one surface of the third magnetic sheet 53 and is slightly moved to one side in the thickness direction with respect to the other end edge E4 in the thickness direction of the wiring 2 .

That is, the third magnetic sheet 53 is disposed on the first magnetic sheet 51 so as to cover the circumferential surface (the arc surface including the other end edge E4 in the thickness direction) of the wiring 2 exposed from the other surface in the thickness direction. The other surface in the thickness direction of the magnetic sheet 51 (implementation of step 5).

Accordingly, when projected in the thickness direction, in the portion overlapping the wiring 2, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, and the second magnetic sheet are sequentially arranged toward the thickness direction side. 52. When projected in the thickness direction, the third magnetic sheet 53 , the first magnetic sheet 51 and the second magnetic sheet 52 are sequentially arranged toward the thickness direction side in the portion not overlapping the wiring 2 .

Through the above-mentioned hot pressing, the sixth step is performed simultaneously with the fourth step and the fifth step.

The hot pressing conditions are selected so that the thermosetting properties of the first adhesive 91, the second adhesive 92, and the third adhesive 93 can be C-staged.

In the sixth step, the first adhesive 91 in the first magnetic sheet 51, the second adhesive 92 in the second magnetic sheet 52, and the third adhesive 93 in the third magnetic sheet 53 are The above-mentioned hot pressing results in C-stage formation.

Therefore, the adhesive 9 contains a cured product (C-stage material) of a B-stage thermosetting component.

Furthermore, by C-staging the first magnetic sheet 51, the second magnetic sheet 52, and the third magnetic sheet 53, the boundary between the first magnetic sheet 51 and the second magnetic sheet 52, and the first magnetic The boundaries between the sheet 51 and the third magnetic sheet 53 disappear, respectively, and one magnetic layer 3 including the first magnetic sheet 51, the second magnetic sheet 52, and the third magnetic sheet 53 is formed (see FIG. 1A). However, the above-mentioned boundaries are described in FIG. 3F in order to clearly show the arrangement of the first magnetic sheet 51 , the second magnetic sheet 52 and the third magnetic sheet 53 .

3.Use Inductor 1 is a part of electronic equipment, that is, a part used to make electronic equipment. It does not contain electronic components (chips, capacitors, etc.) or a mounting substrate for mounting electronic components. It is circulated in the form of a single part and can be Devices used in industry.

The inductor 1 is mounted (assembled) in an electronic device or the like, for example. Although not shown in the figure, the electronic device includes a mounting substrate and electronic components (chips, capacitors, etc.) mounted on the mounting substrate. Furthermore, the inductor 1 is mounted on a mounting substrate via a connecting member such as solder, is electrically connected to other electronic equipment, and functions as a passive component such as a coil.

Furthermore, in this method, as shown in FIG. 2B , in the second step, the first magnetic sheet 51 is disposed on one surface of the first release sheet 41 in the thickness direction in a superior arc manner to cover the wiring 2 . Therefore, the anisotropic magnetic particles 8 can be aligned along the circumferential direction of the wiring 2 in the first magnetic sheet 51 covering the area corresponding to the superior arc of the wiring 2 . Therefore, the obtained inductor 1 has excellent inductance.

Furthermore, in the second step, the first magnetic sheet 51 is arranged on one surface in the thickness direction of the first release sheet 41, so in the first magnetic sheet 51, the first anisotropic magnetic particles 81 are arranged along The thickness direction of the first release sheet 41 is aligned with the surface. Therefore, it is possible to suppress the first anisotropic magnetic property in the circumferentially opposite end edges of the region corresponding to the superior arc of the wiring 2, that is, the second region 12, facing one surface of the first release sheet 41 in the thickness direction. The particles 81 are aligned along the circumferential direction of the wiring 2, so the inductor 1 has excellent DC superposition characteristics.

Furthermore, since the first magnetic sheet 51 covers the superior arc of the circumferential surface of the wiring 2, the alignment direction of the first anisotropic magnetic particles 81 can be aligned with the circumferential direction of the wiring 2 at both end edges of the superior arc. It changes to the direction along one surface of the first release sheet 41, and the first anisotropic magnetic particles 81 are densely arranged. As a result, the inductor 1 having excellent inductance can be manufactured.

Furthermore, as shown in FIG. 3F , in the fourth step, the second magnetic sheet 52 covers one surface of the first magnetic sheet 51 in the thickness direction, so that the peripheral area 4 of the wiring 2 can include the first anisotropy. The anisotropic magnetic particles 8 of the magnetic particles 81 and the second anisotropic magnetic particles 82 are arranged densely. Therefore, the inductor 1 with better inductance can be manufactured.

Therefore, according to this manufacturing method, the anisotropic magnetic particles 8 can be densely arranged in the peripheral region 4, so that the inductor 1 can be manufactured with excellent inductance and excellent DC superposition characteristics.

Furthermore, in this method, as shown in FIG. 3F , the third magnetic sheet 53 is further disposed on the other surface of the first magnetic sheet 51 in the thickness direction, so that the peripheral area 4 of the wiring 2 can include the first magnetic sheet 53 . The anisotropic magnetic particles 81, the second anisotropic magnetic particles, and the third anisotropic magnetic particles 83 are arranged densely. Therefore, the inductor 1 with better inductance can be manufactured.

In particular, since the third magnetic sheet 53 covers the circumferential surface exposed from the other surface of the first magnetic sheet 51 in the thickness direction, the area corresponding to the circumferential surface of the wiring 2 exposed from the first magnetic sheet 51 can be , the third anisotropic magnetic particles 83 are densely arranged. As a result, the inductor 1 having excellent inductance can be manufactured.

Furthermore, in this method, the fourth step and the fifth step are performed simultaneously, so the production time can be shortened compared with the method of sequentially performing the fourth step and the fifth step (see the following modifications). Therefore, the inductor 1 can be manufactured efficiently.

In this method, in the sixth step, the B-stage thermosetting components of the first adhesive 91 and the third adhesive 93 are simultaneously C-staged, so that the first adhesive 91 and the third adhesive are sequentially Compared with the C-stage method of implementing the B-stage thermosetting component of 93 (see the following modifications), the production time can be shortened (see the following modifications). Therefore, the inductor can be manufactured efficiently.

<Modification example of the first embodiment> In the modified example, the same components and steps as those in the first embodiment are assigned the same reference numerals, and detailed descriptions thereof are omitted. In addition, unless otherwise stated, the modified example exhibits the same functions and effects as those of the first embodiment. Furthermore, the first embodiment and its modifications can be combined appropriately.

In the first embodiment, the fourth step, the fifth step and the sixth step are performed simultaneously. However, steps 4 and 5 can be performed, and then step 6 can be performed.

In the first embodiment, the fourth step and the fifth step are performed simultaneously. However, steps 4 and 5 can also be implemented in sequence. Specifically, in this variation, as shown in FIGS. 4A to 6H , the first step, the second step, the fourth step, the third step, the fifth step and the sixth step are sequentially implemented.

As shown in FIG. 4A , in the first step, the wiring 2 is arranged on one surface of the first release sheet 41 in the thickness direction.

Then, as shown in FIG. 4B , in the second step, the first release sheet 41 , the wiring 2 , the first magnetic sheet 51 , the second release sheet 45 and the release sheet are clamped using the flat plate press 42 buffer sheet 46, and then use a flat plate press 42 to heat press the wiring 2 and the first magnetic sheet 51 across the first release sheet 41, the second release sheet 45 and the release buffer sheet 46 . Thereby, the first magnetic sheet 51 is disposed on one surface of the first release sheet 41 in the thickness direction in a superior arc covering the circumferential surface of the wiring 2 .

Subsequently, as shown in Figure 5D, step 4 is performed. Specifically, first, the pressure of the flat plate press 42 shown in FIG. 4B is released, and then, as shown in FIG. 4C , the first release sheet 41 , the wiring 2 and the first magnetic sheet 51 are arranged on In the state of the flat plate press 42, the second release sheet 45 and the release buffer sheet 46 are taken out from the flat plate press 42.

Thereafter, in the fourth step, the second magnetic sheet 52 and the second release sheet 45 are separately arranged on one side of the first magnetic sheet 51 in the thickness direction.

Next, as shown in FIG. 5D , the second magnetic sheet 52 is hot-pressed using the flat plate press 42 . Thereby, the second magnetic sheet 52 covers one surface of the first magnetic sheet 51 .

As shown in Figure 6G, step 3 is performed. Specifically, first, the pressure of the flat plate press 42 shown in FIG. 5D is released, and the first release sheet 41, the wiring 2, the first magnetic sheet 51, and the second magnetic sheet are taken out from the flat plate press 42. material 52 and the second release sheet 45.

In the third step, as shown in FIG. 5E , the first release sheet 41 is peeled off from the other surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2 .

Subsequently, as shown in Figure 5F, step 5 is implemented.

Specifically, in the fifth step, the first release sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52 and the second release sheet 45 are Arranged in the flat plate press machine 42.

In the fifth step, as shown in FIG. 6G , the third magnetic sheet 53 is hot-pressed by the flat plate press 42 . Thereby, the third magnetic sheet 53 is disposed on the other surface of the first magnetic sheet 51 in the B stage so as to cover the other end edge E4 in the thickness direction of the wiring 2 . At this time, the other end edge E4 in the thickness direction of the wiring 2 is sunk into the opposing portion.

Step 6 is performed after step 5 or simultaneously with step 5. Specifically, the first magnetic sheet 51 , the second magnetic sheet 52 and the third magnetic sheet 53 are C-staged to form the C-stage magnetic layer 3 . Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 covering the wiring 2 is obtained.

Thereafter, as shown in FIG. 6H , the inductor 1 is taken out from the flat plate press 42 .

Among this variation and the first embodiment, the first embodiment is preferred. According to the first embodiment, the fourth step and the fifth step are performed simultaneously, so the number of manufacturing steps can be reduced, and the inductor 1 can be easily manufactured.

In the second step of the first embodiment, as shown in FIG. 2B , the second release sheet 45 is placed on the flat plate press 42 . However, the second release sheet 45 may not be placed and hot pressing may be performed.

In the second magnetic sheet 52, the second anisotropic magnetic particles 82 are aligned in the plane direction, but the second anisotropic magnetic particles 82 may not be aligned in the plane direction.

<Second Embodiment> In the second embodiment, the same components and steps as those in the first embodiment and its modifications are assigned the same reference numerals, and detailed descriptions thereof are omitted. In addition, unless otherwise stated, the second embodiment can exhibit the same functions and effects as the first embodiment and its modifications. Furthermore, the first embodiment, the second embodiment, and modifications thereof can be appropriately combined.

In the first embodiment shown in FIGS. 1A and 1B , when projected in the thickness direction, the intersection portion 20 is arranged at intervals on one side of the thickness direction of the other end edge E4 of the wiring 2 , for example, as shown in FIG. As shown in 7A to 7B, it may overlap with the other end edge E4 in the thickness direction of the wiring 2.

As shown in FIGS. 7A and 7B , the fourth region 14 of the inductor 1 of the second embodiment is narrower than the fourth region 14 of the inductor 1 of the first embodiment. Specifically, the angle α2 of the central angle C2 of the fourth region 14 is less than 15° and exceeds 0°.

Next, a method of manufacturing the inductor 1 will be described with reference to FIGS. 8A to 9F.

The manufacturing method of the inductor 1 includes the first to sixth steps. In the manufacturing method of the inductor 1, the first step, the second step and the third step are carried out in sequence, and then the fourth step and the fifth step are carried out simultaneously. Moreover, the 6th step is implemented in batches. Specifically, it is divided into the hot-pressing time in the 2nd step, and the hot-pressing time in the 4th step and the 5th step.

(Step 1) As shown in FIG. 8A , in the first step, the wiring 2 is arranged on one surface of the first release sheet 41 in the thickness direction.

(Part of Step 2 and Step 6) Then, as shown in FIG. 8B , the first release sheet 41 , the wiring 2 , the first magnetic sheet 51 , the second release sheet 45 and the release buffer sheet are sequentially clamped by the flat plate press 42 46. Next, the first magnetic sheet 51 is hot-pressed with the flat plate press 42 . Thereby, the first magnetic sheet 51 is disposed on one surface of the first release sheet 41 in the thickness direction in a superior arc covering the circumferential surface of the wiring 2 .

After the second step or simultaneously with the second step, the first magnetic sheet 51 is heated by the heat source of the flat plate press 42 so that the first magnetic sheet 51 is C-staged (part of the sixth step is performed).

(Step 3) In the third step, first, the pressure of the flat plate press 42 shown in FIG. 8B is released, and then, as shown in FIG. 8C , the first release sheet 41, the wiring 2, and the first release sheet 41 are taken out from the flat plate press 42. 1. Magnetic sheet 51, second release sheet 45 and release buffer sheet 46.

Then, the first release sheet 41 is peeled off from the other surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2 .

Furthermore, the second release sheet 45 and the release buffer sheet 46 are peeled off from one surface of the first magnetic sheet 51 .

(Step 4 and the rest of Step 5 and Step 6) As shown in Figure 9E, steps 4 and 5 are performed simultaneously.

As shown in FIG. 9D , in the fourth step and the fifth step, first, the first release sheet 41 , the third magnetic sheet 53 , the wiring 2 , the first magnetic sheet 51 , and the like are placed on the flat plate press 42 . The second magnetic sheet 52 and the second release sheet 45 . Furthermore, both the first magnetic sheet 51 and the third magnetic sheet 53 are in the B stage.

Subsequently, as shown in FIG. 9E , the first magnetic sheet 51 and the third magnetic sheet 53 are pressed by the flat plate press 42 .

Thereby, the second magnetic sheet 52 covers one surface of the first magnetic sheet 51 in the thickness direction.

The third magnetic sheet 53 is disposed on the other surface of the first magnetic sheet 51 in the thickness direction so as to cover the other end edge E4 in the thickness direction of the wiring 2 . At this time, the movement of the other surface of the relatively hard first magnetic sheet 51 in the C stage is suppressed, and the other end edge E4 in the thickness direction of the wiring 2 is suppressed from sinking into the facing portion 28 of the third magnetic sheet 53 . That is, one surface of the third magnetic sheet 53 can be maintained flat.

Thereafter, the second magnetic sheet 52 and the third magnetic sheet 53 are heated by the heat source of the flat plate press 42, so that the second magnetic sheet 52 and the third magnetic sheet 53 are C-staged (implementation of the sixth step). the rest of the steps).

Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 is obtained.

As shown in FIG. 9F , the inductor 1 is taken out from the flat plate press 42 .

Among the first embodiment and the second embodiment, the first embodiment is preferred. According to the first embodiment, in the sixth step, the B-stage thermosetting components of the first adhesive 91 and the third adhesive 93 are simultaneously C-staged, so that the first adhesive 91 and the third adhesive 93 are Compared with the second embodiment in which the B-stage thermosetting components are sequentially converted into C stages, the production time can be shortened. Therefore, the inductor 1 can be easily manufactured.

<Modification example of the second embodiment> In the modified example, the same components and steps as those in the second embodiment are assigned the same reference numerals, and detailed descriptions thereof are omitted. In addition, unless otherwise stated, the modified example exhibits the same functions and effects as those of the second embodiment. Furthermore, the second embodiment and its modifications can be combined appropriately.

In the second embodiment, the fourth step, the fifth step, and the remaining parts of the sixth step are performed simultaneously. However, it is possible to implement steps 4 and 5, and then implement the remainder of step 6.

In the second embodiment, the fourth step and the fifth step are performed simultaneously. However, steps 4 and 5 can also be implemented in sequence.

In this modified example, as shown in FIGS. 10A to 12H , the first step, the second step, the fourth step, the third step and the fifth step are sequentially implemented. In addition, step 6 is implemented in batches.

As shown in FIG. 10A , in the first step, the wiring 2 is arranged on one surface of the first release sheet 41 in the thickness direction.

As shown in FIG. 10B , the second step is then performed, and the first magnetic sheet 51 is C-staged. That is, implement part of step 6. Specifically, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45 and the release buffer sheet 46 are sequentially clamped by the flat plate press 42. Subsequently, the wiring 2 and the first magnetic sheet 51 are hot-pressed with the flat plate press 42 via the first release sheet 41 , the second release sheet 45 and the release buffer sheet 46 . Furthermore, the first magnetic sheet 51 is C-staged using the heat source of the flat plate press 42 (part of step 6 is carried out).

As shown in Figure 11D, step 4 is then implemented. Specifically, first, the pressure of the flat plate press 42 shown in FIG. 10B is released, and then, as shown in FIG. 10C , the first release sheet 41 , the wiring 2 and the first magnetic sheet 51 are arranged on In the state of the flat plate press 42, the second release sheet 45 and the release buffer sheet 46 are taken out from the flat plate press 42.

Thereafter, in the fourth step, the second magnetic sheet 52 and the second release sheet 45 are separately arranged on one side of the first magnetic sheet 51 in the thickness direction.

As shown in FIG. 11D , the second magnetic sheet 52 is then hot-pressed using the flat plate press 42 . Thereby, the second magnetic sheet 52 covers one surface of the first magnetic sheet 51 .

As shown in Figure 11F, step 3 is then implemented.

In the third step, specifically, first, the pressure of the flat plate press 42 shown in FIG. 11D is released, and the first release sheet 41, the wiring 2, and the first magnetic sheet are taken out from the flat plate press 42. 51. The second magnetic sheet 52 and the second release sheet 45.

In the third step, as shown in FIG. 11E , the first release sheet 41 is peeled off from the other surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2 .

As shown in Figure 12G, step 5 is then implemented.

As shown in FIG. 11F , in the fifth step, first, specifically, the first release sheet 41 , the third magnetic sheet 53 , the wiring 2 , the first magnetic sheet 51 , and the second magnetic sheet 52 are And the second release sheet 45 is arranged on the flat plate press 42 .

In the fifth step, as shown in FIG. 12G , the third magnetic sheet 53 is hot-pressed by the flat plate press 42 . Thereby, the third magnetic sheet 53 is disposed on the other surface of the first magnetic sheet 51 in the C stage so as to cover the other end edge E4 in the thickness direction of the wiring 2 .

After step 5 or simultaneously with step 5, perform the remainder of step 6. Specifically, the second magnetic sheet 52 and the third magnetic sheet 53 are C-staged by the heat source of the flat plate press 42 to form the third magnetic sheet 53 , the first magnetic sheet 51 and the third magnetic sheet 51 . 2. Magnetic layer 3 of magnetic sheet 52. Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 covering the wiring 2 is obtained.

As shown in FIG. 12H , the inductor 1 is then taken out from the flat plate press 42 .

Furthermore, in the above modification example, the first magnetic sheet 51 is C-staged simultaneously with the second step of arranging the first magnetic sheet 51 for the wiring 2 shown in FIG. 10B , but the first magnetic sheet 51 is C-staged. There is no particular limitation on the period of C-stage transformation of 51 as long as it is before the fifth step of arranging the other surface of the first magnetic sheet 51 on the third magnetic sheet 53 (refer to FIG. 5G ). For example, it can also be as shown in FIG. The fourth step of arranging the second magnetic sheet 52 shown in 11D is performed together.

Furthermore, the first magnetic sheet 51 and the second magnetic sheet 52 can be C-staged simultaneously. The second magnetic sheet 52 is arranged on one surface of the first magnetic sheet 51 in the B-stage, and then the first magnetic sheet 51 and the second magnetic sheet 52 are simultaneously C-staged. Alternatively, the second magnetic sheet 52 may be C-staged, and then the third magnetic sheet 53 may be disposed on the other surface of the first magnetic sheet 51 and then C-staged.

Alternatively, the third magnetic sheet 53 may be disposed on the other surface of the first magnetic sheet 51, and then the second magnetic sheet 52 may be disposed on one surface of the first magnetic sheet 51. In this case, the third magnetic sheet 53 and the second magnetic sheet 52 may be C-staged at the same time, and the third magnetic sheet 53 may be C-staged, and then the second magnetic sheet 52 may be C-staged. C-stage.

Alternatively, as shown in FIG. 13A , in the first step, the wiring 2 can be arranged on a surface in the thickness direction of the third magnetic sheet 53 (an example of the substrate) in the C stage, instead of being arranged on the first release sheet. Material 41.

Specifically, first, the third magnetic sheet 53 in the C stage is produced and disposed on one surface of the first release sheet 41 in the thickness direction. The third adhesive 93 in the third magnetic sheet 53 contains a cured product of a B-stage thermosetting component.

Then, the first release sheet 41, the third magnetic sheet 53 of the C stage, the wiring 2, the first magnetic sheet 51, the second release sheet 45 and the release buffer are clamped by the flat plate press 42 Sheet 46.

As shown in Figure 13B, step 2 is performed. In this second step, the first release sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, and the second release sheet 45 are sequentially clamped by the flat plate press 42 and release buffer sheet 46.

Then, the first release sheet 41 , the second release sheet 45 and the release buffer sheet 46 are separated from the third magnetic sheet 53 , the wiring 2 and the first magnetic sheet 51 by the flat plate press 42 Perform hot pressing. Thereby, the first magnetic sheet 51 is disposed on one surface of the third magnetic sheet 53 in the C stage in the thickness direction in a superior arc covering the circumferential surface of the wiring 2 .

Then, in the fourth step, first, the pressure of the flat plate press 42 shown in FIG. 13B is released, and then, as shown in FIG. 13C, the first release sheet 41, the third magnetic sheet 53, With the wiring 2 and the first magnetic sheet 51 arranged on the flat plate press 42 , the second release sheet 45 and the release buffer sheet 46 are taken out from the flat plate press 42 .

Subsequently, in the subsequent fourth step, the second magnetic sheet 52 and the second release sheet 45 are separately arranged on one side of the first magnetic sheet 51 in the thickness direction. The first release sheet 41 , the third magnetic sheet 53 , the wiring 2 , the first magnetic sheet 51 , the second magnetic sheet 52 and the second release sheet 45 are clamped by the flat plate press 42 .

Thereafter, as shown in FIG. 14D , the second magnetic sheet 52 is pressed by the flat plate press 42 .

Thereafter, the second magnetic sheet 52 and the first magnetic sheet 51 are C-staged. Thereby, the magnetic layer 3 including the third magnetic sheet 53, the first magnetic sheet 51, and the second magnetic sheet 52 is formed.

Thereafter, as shown in Fig. 14E, the inductor 1 is obtained.

In the above variation, the first magnetic sheet 51 and the second magnetic sheet 52 are C-staged at the same time. However, for example, the second magnetic sheet 52 may be C-staged after the first magnetic sheet 51 is C-staged. Be C-staged.

＜Other variation examples＞ In this variation, the same components and steps as those in the first and second embodiments are assigned the same reference numerals, and detailed descriptions thereof are omitted. In addition, unless otherwise stated, the modified examples can exhibit the same functions and effects as those of the first and second embodiments. Furthermore, the first and second embodiments and their modifications can be combined appropriately.

As shown in FIG. 15A , in the first step, the wiring 2 can be arranged on one surface of the first release sheet 41 via the pressure-sensitive adhesive layer 61 .

The pressure-sensitive adhesive layer 61 extends in the second direction and is formed into a thin sheet shape. The ratio of the length of the pressure-sensitive adhesive layer 61 in the first direction to the radius R of the wiring 2 is, for example, 0.5 or less and 0.25 or less.

As shown in FIG. 15B , in the second step, the first magnetic sheet 51 covers the superior arc of the circumferential surface of the wiring 2 so as to fill both sides of the pressure-sensitive adhesive layer 61 in the first direction.

As shown in FIG. 15C , the pressure-sensitive adhesive layer 61 of the inductor 1 may not remain between the third magnetic sheet 53 and the other end edge E4 in the thickness direction, or, although not shown, the pressure-sensitive adhesive layer 61 may be removed after the second step. Layer 61 is pressed.

Moreover, as shown in FIG. 16A , in the first step, the wiring 2 can be arranged on one side of the first release sheet 41 with a gap 62 separated. For example, by interposing spacers (not shown) between both ends of the wiring 2 in the second direction and the first release sheet 41, the two sides in the second direction are stretched and the wiring 2 is ensured to be The other end edge E4 in the thickness direction is separated from one surface of the wiring 2 by a gap 62 .

As shown in FIG. 16B , in the second step of hot pressing, the first magnetic sheet 51 is filled into the gap 62 and covers the entire circumferential surface of the wiring 2 .

Thereafter, as shown in FIG. 16C , one surface of the first magnetic sheet 51 is covered with the second magnetic sheet 52 .

Thereafter, heating and pressure are performed simultaneously, for example, so that the first adhesive 91 of the first magnetic sheet 51 and the second adhesive 92 of the second magnetic sheet 52 are C-staged.

Thereby, the magnetic layer 3 including the first magnetic sheet 51 and the second magnetic sheet 52 is formed.

In this method, the third magnetic sheet 53 may not be disposed, but the other end edge E4 in the thickness direction of the wiring 2 may be covered with the magnetic layer 3 . Therefore, the number of steps can be reduced.

Furthermore, as shown by the imaginary line in FIG. 16C , the third magnetic sheet 53 may also be disposed on the other surface of the second magnetic sheet 52 if necessary.

Alternatively, as shown in FIG. 2A , in the first step, the wiring 2 can be brought into contact with one surface of the first release sheet 41 , as shown by the imaginary line arrow in FIG. 6B , and then the added value in the second step can be adjusted. The first magnetic composition forming the first magnetic sheet 51 is embedded in the other side of the wiring 2 in the thickness direction so as to cover the other end edge E4 in the thickness direction of the wiring 2 according to the pressing conditions. In this variation, the above-mentioned spacer is not required, so the inductor 1 can be easily manufactured.

In the first embodiment and the second embodiment, the first anisotropic magnetic particles 81 are exemplified as an example of the first magnetic particles. However, the first magnetic particles may not have anisotropy, but may have isotropy, for example. . Examples of the shape of the first isotropic magnetic particles include a substantially spherical shape. Examples of the substantially spherical first isotropic magnetic particles include substantially spherical iron particles. The average particle diameter of the first isotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and, for example, 200 μm or less, preferably 150 μm or less.

Furthermore, as shown in FIG. 2A of the first embodiment, FIG. 4A of its modification, FIG. 8A of the second embodiment and FIG. 10A and FIG. 13A of its modification, the first anisotropic magnetic particles 81 are in the first magnetic The sheet 51 is aligned in the plane direction, but it is not limited to this, and the first magnetic sheet 51 does not need to be aligned in the plane direction.

In the first embodiment and the second embodiment, the third anisotropic magnetic particles 83 are exemplified as an example of the third magnetic particles. For example, the third magnetic particles may not have anisotropy, but may have isotropy. Examples of the shape of the third isotropic magnetic particles include a substantially spherical shape. Examples of the substantially spherical third isotropic magnetic particles include substantially spherical iron particles. The average particle diameter of the third isotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and, for example, 200 μm or less, preferably 150 μm or less.

Furthermore, as shown in FIG. 3D of the first embodiment, FIG. 5F of its modification, FIG. 9D of the second embodiment, and FIG. 11F and FIG. 13C of its modification, the third anisotropic magnetic particles 83 are in the third magnetic field. The sheet 53 is aligned in the plane direction, but it is not limited to this, and the third magnetic sheet 53 does not need to be aligned in the plane direction.

As shown in FIGS. 1B and 7B , in the first embodiment and the second embodiment, the anisotropic magnetic particles 8 are aligned along the circumferential direction of the wiring 2 at least in the first region 11 , but it is not limited to this. Or it may not be aligned along the circumferential direction of the wiring 2 .

In addition, the ratio (filling ratio) of the magnetic particles (the first magnetic particles, the second anisotropic magnetic particles 82 and the third magnetic particles) in the magnetic layer 3 is not limited to the above. For example, it may become higher or higher as the distance from the wiring 2 increases. become lower. In order to manufacture the inductor 1 in which the ratio of the magnetic particles in the magnetic layer 3 becomes higher as the distance from the wiring 2 increases, for example, the ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 is set to be higher than The presence ratio of magnetic particles in the first magnetic sheet 51.

Furthermore, as mentioned above, in the variation example in which the filling ratio of the magnetic particles in the magnetic layer 3 becomes higher or lower as the distance from the wiring 2 increases, the magnetic layer 3 may be a plurality of layers. In this case, one of the plurality of magnetic sheets used to cover the outer peripheral surface of the wiring 2 can be used to pressurize the wiring 2, and then the remaining magnetic sheets can be used to pressurize the wiring 2. , or the wiring 2 may be pressurized with a plurality of magnetic sheets at one time (unified). For example, the first magnetic sheet 51 , the second magnetic sheet 52 , and the third magnetic sheet 53 according to one embodiment can be used at once to pressurize the wiring 2 . Specifically, the first step shown in FIG. 13A, the second step shown in FIG. 13B, and the fourth step shown in FIG. 13C can be implemented simultaneously. [Example]

Examples and comparative examples are shown below to explain the present invention more specifically. In addition, the present invention is not limited to any examples and comparative examples. In addition, specific numerical values such as blending ratios (containing ratios), physical property values, and parameters used in the following description may be substituted for corresponding blending ratios (containing ratios) described in the above "Modes for Carrying out the Invention". The upper limit (defined as the value of "below" or "under") or the lower limit (defined as the value of "above" or "exceed") of the corresponding recording of physical property values and parameters.

Example 1 <Manufacturing example of inductor based on the first embodiment> In Example 1, the inductor 1 was manufactured based on the first embodiment. Specifically, as shown in FIGS. 2A to 3F , the first step, the second step, and the third step are sequentially implemented, and then the fourth step, the fifth step, and the sixth step are implemented simultaneously.

(Step 1) Prepare the wiring 2 and the first release sheet 41.

Specifically, a wiring 2 with a radius R of 110 μm is prepared. The radius R1 of the wire 6 is 100 μm, and the thickness R2 of the insulating layer 7 is 10 μm.

Separately prepare the first release sheet 41 containing PET with a thickness of 50 μm.

Next, as shown in FIG. 2A , the wiring 2 is arranged on one surface in the thickness direction of the first release sheet 41 .

(Step 2) Prepare the first magnetic sheet 51, the second release sheet 45, and the release buffer sheet 46.

Specifically, the first magnetic sheet 51 composed of a laminated sheet of the inner sheet 54 and the outer sheet 55 is prepared as a B-stage sheet. The ratio of the anisotropic magnetic particles 8 in the inner sheet 54 is 50 by volume. %, and the ratio of the anisotropic magnetic particles 8 in the outer sheet 55 is 60 volume %. The formulas of the inner sheet 54 and the outer sheet 55 are as described in Table 1.

Furthermore, as the second release sheet 45, a release film (manufactured by Mitsui Chemicals Tohcello Co., Ltd.) containing TPX (registered trademark) is prepared.

Furthermore, a release buffer sheet 46 in which two release films OT-A110 (manufactured by Sekisui Chemical Industry Co., Ltd.) were laminated was prepared.

The thickness of the release buffer sheet 46 (the total thickness of the release film OT-A110) is 110 μm, and it has a first layer 47 with a thickness of 15 μm, a second layer 48 with a thickness T2 of 80 μm, and a thickness of 15 μm. The third floor is 49. The tensile storage modulus E' of the first layer 47 and the third layer 49 at 110°C is 190 MPa, and their materials contain polybutylene terephthalate as the main component. The tensile storage modulus E' of the second layer 48 at 110°C is 5.6 MPa, and its material contains ethylene-methyl methacrylate copolymer as the main component.

Subsequently, the first release sheet 41 , the wiring 2 , the first magnetic sheet 51 , the second release sheet 45 and the release buffer sheet 46 are sequentially clamped by the flat plate press 42 .

As shown in FIG. 2B , the wiring 2 and the first magnetic sheet 51 are then hot-pressed by the flat plate press 42 under the pressing conditions of 2 MPa pressure, 110° C. and 60 seconds.

FIG. 17A shows an SEM photograph of the cross section of the wiring 2 and the first magnetic sheet 51 after the second step.

(Step 3) In the third step, first, the pressure of the flat plate press 42 shown in FIG. 2B is released, and then, as shown in FIG. 2C , the first release sheet 41, the wiring 2, and the first release sheet 41 are taken out from the flat plate press 42. 1. Magnetic sheet 51, second release sheet 45 and release buffer sheet 46. Then, the first release sheet 41 is peeled off from the other surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2 . Furthermore, the second release sheet 45 and the release buffer sheet 46 are peeled off from one surface of the first magnetic sheet 51 .

(Step 4, Step 5 and Step 6) The second magnetic sheet 52 and the third magnetic sheet 53 are prepared.

Specifically, five sheets having the same formula as the outer sheet 55 of the first magnetic sheet 51 (the ratio of the anisotropic magnetic particles 8 is 60% by volume) are prepared, and a laminated sheet made of them is prepared. The second magnetic sheet 52 is configured as a B-stage sheet.

Furthermore, four sheets having the same formula as the outer sheet 55 of the first magnetic sheet 51 (the ratio of the anisotropic magnetic particles 8 is 60% by volume), and one sheet having the same formula as the outer sheet 55 of the first magnetic sheet 51 are prepared. The inner sheet 54 has the same formula (the ratio of the anisotropic magnetic particles 8 is 50% by volume) and is laminated to prepare the third magnetic sheet 53 composed of the laminated sheets as a B-stage sheet. .

As shown in FIG. 3D , then, between the first plate 43 and the second plate 44 , the first release sheet 41 , the third magnetic sheet 53 , the wiring 2 and the first magnetic sheet are sequentially arranged toward the thickness direction side. Sheet 51, second magnetic sheet 52, and second release sheet 45 (PET film).

As shown in FIG. 3E , under the pressing conditions of 2 MPa pressure, 170° C. and 900 seconds, the flat plate press 42 presses the third magnetic sheet 53 , the wiring 2 , the first magnetic sheet 51 and The second magnetic sheet 52 is hot pressed. Thereby, the thermosetting component in the first adhesive 91 , the second adhesive 92 and the third adhesive 93 is C-staged.

Thereby, the circumferential surface of the wiring 2 is covered with the magnetic layer 3 including the first magnetic sheet 51, the second magnetic sheet 52, and the third magnetic sheet 53 of the C stage, and the circuit shown in FIGS. 1A to 1B is manufactured. Inductor 1.

Thereafter, as shown in FIG. 3F , the inductor 1 is taken out from the flat plate press 42 .

An SEM photograph of the cross section of the inductor 1 is shown in FIG. 17B.

Example 2 <Example of manufacturing an inductor based on a modified example of the first embodiment> In Example 2, the inductor 1 is manufactured based on the modification of the first embodiment shown in FIGS. 4A to 6H . Specifically, the process was performed in the same manner as in Example 1, except that the first step, the second step, the fourth step, the third step, the fifth step and the sixth step were sequentially implemented.

This inductor 1 is shown in FIGS. 7A and 7B, and an SEM photograph of its cross section is shown in FIG. 18.

Example 3 to Example 5 According to Table 1, the inductor 1 was manufactured in the same manner as in Example 1 except that the formula of the first magnetic sheet 51 was changed.

Comparative example 1 On one side of the first plate 43 in the thickness direction, the first release sheet 41 containing PET with a thickness of 50 μm, the third magnetic sheet 53 of the C stage, the first adhesive layer of the B stage, and the embodiment are sequentially arranged. 1 The same wiring 2, the second adhesive layer of the B stage, the second magnetic sheet 52 of the C stage, the second release sheet 45 including TPX, and 2 pieces of release film OT-A110 (manufactured by Sekisui Chemical Industry Co., Ltd. ), the release buffer sheet 46 obtained by laminating them is sandwiched between the first plate 43 and the second plate 44 .

In addition, both the first adhesive layer and the second adhesive layer are B-stage sheets that do not contain the anisotropic magnetic particles 8 but contain thermosetting resin. The thicknesses of the first adhesive layer and the second adhesive layer are respectively 2 μm.

The formulas of the second magnetic sheet 52 in the C stage and the third magnetic sheet 53 in the C stage are as recorded in Table 1, and both are completely hardened hardened bodies.

Subsequently, the above-mentioned laminated body was hot-pressed by the flat plate press 42 under the pressure conditions of 2 MPa, 170° C. and 900 seconds, and the inductor 1 was manufactured.

An SEM photograph of the cross section of the inductor 1 of Comparative Example 1 is shown in FIG. 19 .

As can be seen from FIG. 19 , voids are formed between the second arc surface 24 of the wiring 2 and both end edges E2 and E3 in the first direction, and the first magnetic sheet 51 (magnetic layer 3 ).

Comparative example 2 On one side of the first plate 43 in the thickness direction, the first release sheet 41 containing PET with a thickness of 50 μm, the third magnetic sheet 53 of the C stage, the first pressure-sensitive adhesive layer, and Example 1 are sequentially arranged. The same wiring 2, the second pressure-sensitive adhesive layer, the second magnetic sheet 52 of the C stage, the second release sheet 45 containing TPX, and laminated two pieces of release film OT-A110 (manufactured by Sekisui Chemical Industry Co., Ltd.) The obtained release buffer sheet 46 has a laminate containing the same sandwiched between the first plate 43 and the second plate 44 .

Furthermore, both the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are pressure-sensitive adhesive tapes (adhesive tapes) that do not include the anisotropic magnetic particles 8 but include an acrylic pressure-sensitive adhesive agent (adhesive agent). The thicknesses of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are respectively 5 μm.

The formulas of the second magnetic sheet 52 in the C stage and the third magnetic sheet 53 in the C stage are as recorded in Table 1, and both are completely hardened hardened bodies.

Subsequently, the above-mentioned laminated body was hot-pressed by the flat plate press 42 under the pressurizing conditions of 2 MPa, 110° C. and 60 seconds, and the inductor 1 was manufactured.

A void is formed between the second arc surface 24 of the wiring 2 and both end edges E2 and E3 in the first direction, and the first magnetic sheet 51 (magnetic layer 3).

＜Filling rate＞ Based on the binarization of the cross-sectional view of the SEM photograph, the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 of the inductor 1 was calculated. Specifically, in the SEM photograph, the white color is identified as the anisotropic magnetic particles 8 and the black color is identified as the binder 9. Then, based on the ratio of the cross-sectional area of the white color in the first region 11, the anisotropic magnetic particles are determined Fill rate (existence ratio) of 8.

The results are shown in Table 1.

＜Inductor＞ The two ends of the conductor 6 in the transmission direction are exposed from the insulating layer 7 and the magnetic layer 3 to form two exposed parts. These exposed parts are connected to an impedance analyzer (manufactured by Agilent: 4294A), and the inductance is determined based on the following criteria. Evaluate the inductance of inductor 1. ◎: Inductance is 110 H or more ○: Inductance is 90 H or more but less than 110 H △: Inductance is above 60 H, but less than 90 H ×: The inductance does not reach 60 H The results are shown in Table 1.

[Table 1] Table 1 Magnetic composition Example 1/Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 1st magnetic sheet 1st magnetic sheet 1st magnetic sheet 1st magnetic sheet 2nd magnetic sheet/3rd magnetic sheet 2nd magnetic sheet/3rd magnetic sheet Stage B 2-layer sheet Stage B 2-layer sheet Stage B 2-layer sheet Stage B 2-layer sheet The adhesive sheet in the B stage and the magnetic sheet in the C stage Pressure-sensitive adhesive tape and C-stage magnetic sheet inner sheet outer sheet single sheet single sheet single sheet Inner sheet* ¹ Outside sheet* ² Inner sheet* ³ Outside sheet* ² Volume % Volume % Volume % Volume % Volume % Volume % Volume % Volume % Volume % magnetic particles Flat soft magnetic particles Fe-Si-Al alloy (average particle size 40 μm) 50 60 50 40 30 0 60 0 60 thermoplastic components Carboxyl-containing acrylate copolymer Tessan resin SG-70L manufactured by Nagase ChemteX Co., Ltd. 23.7 18.8 23.7 28.5 33.5 48.6 18.8 - 18.8 Thermosetting component (epoxy resin composition) Cresol novolac epoxy resin (main agent) KI-3000-4 manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd. has an epoxy equivalent of 199 g/eq 12.2 9.7 12.2 14.7 17.2 25.1 9.7 9.7 Phenolic resin (hardener) MEH-7851SS manufactured by Meiwa Kasei Co., Ltd. 12.4 9.8 12.4 15.0 17.6 25.5 9.8 9.8 Imidazole compound (hardening accelerator) 2PHZ-PW manufactured by Shikoku Chemical Industry Co., Ltd. 0.4 0.3 0.4 0.5 0.6 0.8 0.3 0.3 Filling rate of anisotropic magnetic particles in the surrounding area (volume %) 57 55 53 58 34 18 Whether there are pores without without without without have have Evaluation(Inductor) ◎ ◎ 〇 〇 △ × *1: B-stage adhesive sheet *2: C-stage magnetic sheet *3: Pressure-sensitive adhesive tape

In addition, the above-mentioned invention is provided as an exemplary embodiment of the present invention, but this is only an example and should not be interpreted restrictively. Modifications of the present invention that are clear to those skilled in the art are included in the scope of the following claims. [Industrial availability]

Inductors are mounted on electronic equipment, for example.

1:Inductor 2: Wiring 3: Magnetic layer 4: Surrounding area 5: Outside area 6: Wire 7: Insulation layer 8:Anisotropic magnetic particles 9: Adhesive 11: Area 1 12:Zone 2 13: Area 3 14: Area 4 15: Area 5 16:Region 6 17: 1st particle 18: 2nd particle 19:The third particle 20: Cross section (top) 21: 1st intersection (1st top) 22: 2nd intersection (2nd top) 23: The first semicircular arc surface 24: The second semicircular arc surface 25: bulge 26: Plana 27: 2nd top 28: Opposite part 29: 2nd flat part 34:Overlapping part 35: Non-overlapping part 38: The squeezed part 41: The first release sheet 42:Plate press 43:Plate 1 44:Plate 2 45: 2nd release sheet 46: Release buffer sheet 47:Level 1 48:Layer 2 49:Level 3 51: 1st magnetic sheet 52: 2nd magnetic sheet 53: 3rd magnetic sheet 54:Inner sheet 55:Outside sheet 61: Pressure-sensitive bonding layer 62: Gap 81: First anisotropic magnetic particle (an example of the first magnetic particle) 82: Second anisotropic magnetic particle (an example of the second magnetic particle) 83: The third anisotropic magnetic particle (an example of the third magnetic particle) 91: 1st adhesive 92:Second adhesive 93: 3rd adhesive A1: 1st imaginary arc A2: The second imaginary arc C: Center of wiring C1: Center angle (3rd area) C2: Center angle (4th area) C3: Center of the first imaginary arc C4: Center of the second imaginary arc E1: end edge E2: end edge E3: end edge E4: end edge E5: Terminal 1 E6: Terminal 2 E7: Terminal 3 E8: Terminal 4 L1: 1st imaginary line L2: 2nd imaginary line L3: The third imaginary line R1:radius R2:Thickness α1: Angle of central angle (3rd area) α2: Angle of central angle (4th area)

1A to 1B are cross-sectional views of the inductor obtained according to the first embodiment of the present invention. FIG. 1A is a hatched cross-sectional view, and FIG. 1B is a cross-sectional view showing the alignment of anisotropic magnetic particles in the magnetic layer. 2A to 2C are step diagrams illustrating the method of manufacturing the inductor according to the first embodiment. FIG. 2A shows the first step of arranging the wiring on the first release sheet, and FIG. 2B shows the step of covering the wiring with the first magnetic sheet. The second step, Figure 2C shows the third step of removing the first release sheet. 3D to 3F are step diagrams following FIG. 2C , illustrating the method of manufacturing the inductor of the first embodiment. FIG. 3D shows the steps of arranging the second magnetic sheet and the third magnetic sheet. FIG. 3E shows the use of the second magnetic sheet. The fourth step of covering one surface of the first magnetic sheet with a magnetic sheet, and the fifth step of covering the other surface of the first magnetic sheet in stage B with a third magnetic sheet. Figure 3F shows the steps of taking out the inductor. . 4A to 4C are step diagrams illustrating the manufacturing method of the variation of the first embodiment. FIG. 4A shows the first step of arranging the wiring on the first release sheet, and FIG. 4B shows the step of covering the wiring with the first magnetic sheet. In the second step, FIG. 4C shows the step of arranging the second magnetic sheet. 5D to 5F are step diagrams following FIG. 4C , illustrating the manufacturing method of the variation of the first embodiment. FIG. 5D shows the fourth step of covering one surface of the first magnetic sheet with the second magnetic sheet. FIG. 5E shows the third step of removing the first release sheet, and FIG. 5F shows the step of arranging the third magnetic sheet. 6G to 6H are step diagrams following FIG. 5F , illustrating the manufacturing method of the variation of the first embodiment. FIG. 6G shows the other surface of the first magnetic sheet in the B stage covered with the third magnetic sheet. 5 steps, Figure 6H shows the steps to take out the inductor. 7A to 7B are cross-sectional views of the inductor obtained according to the second embodiment of the present invention. FIG. 7A is a cross-sectional view with hatching processing, and FIG. 7B is a cross-sectional view showing the alignment of anisotropic magnetic particles in the magnetic layer. 8A to 8C are step diagrams illustrating the method of manufacturing the inductor according to the second embodiment. FIG. 8A shows the first step of arranging the wiring on the first release sheet, and FIG. 8B shows the step of covering the wiring with the first magnetic sheet. The second step, Figure 8C shows the third step of removing the first release sheet. 9D to 9F are step diagrams following FIG. 8C , illustrating the method of manufacturing the inductor of the second embodiment. FIG. 9D shows the steps of arranging the second magnetic sheet and the third magnetic sheet. FIG. 9E shows the use of the second magnetic sheet. The fourth step of covering one surface of the first magnetic sheet with the magnetic sheet, and the fifth step of covering the other surface of the first magnetic sheet in stage C with the third magnetic sheet. Figure 9F shows the steps of taking out the inductor. . 10A to 10C are step diagrams illustrating the manufacturing method of a variation of the second embodiment. FIG. 10A shows the first step of arranging wiring on the first release sheet, and FIG. 10B shows covering the wiring with the first magnetic sheet. In the second step, FIG. 10C shows the step of arranging the second magnetic sheet. 11D to 11F are step diagrams following FIG. 10C , illustrating the manufacturing method of the variation of the second embodiment. FIG. 11D shows the fourth step of covering one surface of the first magnetic sheet with the second magnetic sheet. FIG. 11E shows the third step of removing the first release sheet, and FIG. 11F shows the step of arranging the third magnetic sheet. 12G to 12H are step diagrams following FIG. 11F , illustrating the manufacturing method of the variation of the second embodiment. FIG. 12G shows the other surface of the first magnetic sheet in the C stage covered with the third magnetic sheet. 5 steps, Figure 12H shows the steps to remove the inductor. 13A to 13C are step diagrams illustrating a manufacturing method according to another variation of the second embodiment. FIG. 13A shows the step of arranging wiring with the third magnetic sheet in the C stage. FIG. 13B shows covering with the first magnetic sheet. As for the steps of wiring and one surface of the third magnetic sheet, Figure 13C shows the steps of arranging the second magnetic sheet. 14D to 14E are step diagrams following FIG. 13C , illustrating the manufacturing method of another variation of the second embodiment. FIG. 14D shows the step of covering the first magnetic sheet with the second magnetic sheet, and FIG. 14E shows the removal. Inductor steps. 15A to 15C are cross-sectional views of a modified example of the manufacturing method of the inductor. FIG. 15A shows the step of arranging wiring on one surface of the first release sheet through the pressure-sensitive adhesive layer. FIG. 15B shows the use of the first magnetic sheet. Figure 15C shows the steps for obtaining an inductor, including a region of the circumferential surface of the material-coated wiring that exceeds 180° when viewed in cross-section, and one surface of the first magnetic sheet. 16A to 16C are cross-sectional views of a modified example of the manufacturing method of the inductor. FIG. 16A shows the step of arranging the wiring and the first release sheet at intervals. FIG. 16B shows the circumference of the wiring covered with the first magnetic sheet. Fig. 16C shows the steps of obtaining an inductor by touching one surface of the first magnetic sheet. 17A to 17B are image processing diagrams of the SEM photograph of Example 1, FIG. 17A is the SEM photograph after the second step, and FIG. 17B is the SEM photograph of the inductor. Figure 18 is an image processing diagram of an SEM photograph of the inductor of Example 2. Figure 19 is an image processing diagram of an SEM photograph of the inductor of Comparative Example 1.

2: Wiring

5: Outside area

6: Wire

7: Insulation layer

8:Anisotropic magnetic particles

9: Adhesive

12:Zone 2

13: Area 3

15: Area 5

16:Region 6

20: Cross section (top)

21: 1st intersection (1st top)

23: The first semicircular arc surface

24: The second semicircular arc surface

25: bulge

26: Plana

27: 2nd top

34:Overlapping part

35: Non-overlapping part

38: The squeezed part

41: The first release sheet

42:Plate press

43:Plate 1

44:Plate 2

45: 2nd release sheet

46: Release buffer sheet

47:Level 1

48:Layer 2

49:Level 3

51: 1st magnetic sheet

54:Inner sheet

55:Outside sheet

81: First anisotropic magnetic particle (an example of the first magnetic particle)

91: 1st adhesive

E1: end edge

E2: end edge

E3: end edge

E4: end edge

Claims (8)

A method of manufacturing an inductor, characterized by: The first step is to arrange wiring on a surface in the thickness direction of the substrate. The wiring includes conductors and an insulating layer covering the conductors, and has a generally circular cross-sectional shape; The second step is to arrange the first magnetic sheet on a surface in the thickness direction of the above-mentioned substrate in a manner that covers an area of the circumferential surface of the wiring that exceeds 180° when viewed in cross-section, and the first magnetic sheet contains the first magnetic sheet. Magnetic particles, and the first binder used to disperse the above-mentioned first magnetic particles; and The fourth step is to cover one surface of the first magnetic sheet in the thickness direction with a second magnetic sheet, and the second magnetic sheet contains a second magnetic layer including second anisotropic magnetic particles aligned in the plane direction. particles, and a second binder for dispersing the second magnetic particles, and the first magnetic sheet covers the above-mentioned area of the above-mentioned circumferential surface and the above-mentioned surface of the above-mentioned substrate. The method of manufacturing an inductor according to claim 1, wherein the first magnetic particles include first anisotropic magnetic particles, and the first anisotropic magnetic particles are aligned in the plane direction in the first magnetic sheet. The manufacturing method of the inductor of claim 1 or 2, wherein The above-mentioned substrate is a release sheet. The manufacturing method of the inductor further includes: The third step is to remove the above-mentioned substrate; and The fifth step is to arrange the third magnetic sheet on the other surface of the first magnetic sheet in the thickness direction so as to cover the circumferential surface exposed from the other surface of the first magnetic sheet in the thickness direction, The third magnetic sheet contains third magnetic particles and a third binder for dispersing the third magnetic particles. The method for manufacturing an inductor according to claim 3, wherein the third magnetic particles include third anisotropic magnetic particles, and the third anisotropic magnetic particles are aligned in the plane direction in the third magnetic sheet. For example, the manufacturing method of the inductor of Claim 3 is to implement the above-mentioned first step, the above-mentioned second step and the above-mentioned third step in sequence, and then implement the above-mentioned fourth step and the above-mentioned fifth step at the same time. The method for manufacturing an inductor of claim 3, wherein the first adhesive in the second step and the third adhesive in the fifth step contain a B-stage thermosetting component, The manufacturing method of the inductor further includes a sixth step of simultaneously converting the B-stage thermosetting components of the first adhesive and the third adhesive into C-stages. The method of manufacturing an inductor according to claim 1 or 2, wherein the substrate is a third magnetic sheet that contains third magnetic particles and a third adhesive for dispersing the third magnetic particles, The above-mentioned third adhesive contains a cured product of a thermosetting component. The method for manufacturing an inductor according to claim 7, wherein the third magnet particles include third anisotropic magnet particles, and the third anisotropic magnet particles are aligned in the plane direction in the third magnet sheet.