阅读说明：本技术 电感器的制造方法 (Method for manufacturing inductor ) 是由 奥村圭佑 古川佳宏 于 2020-02-05 设计创作，主要内容包括：电感器(1)的制造方法包括：第1工序,在该第1工序中,将布线(2)配置于基板的厚度方向一侧面,该布线(2)具有在剖视时呈大致圆形的形状且包括导线(6)和覆盖导线(6)的绝缘层(7)；第2工序,在该第2工序中,将第1磁性片(51)以覆盖布线(2)的圆周面的优弧的方式配置于第1脱模片(41)的厚度方向一侧面,该第1磁性片(51)含有第1磁性颗粒和使第1磁性颗粒分散的第1粘结剂(91)；以及第4工序,在该第4工序中,利用第2磁性片(52)对覆盖布线(2)的圆周面的优弧和第1脱模片(41)的一侧面的第1磁性片(51)的厚度方向一侧面进行覆盖,该第2磁性片(52)含有第2磁性颗粒和使第2磁性颗粒分散的第2粘结剂(92)。(The method for manufacturing the inductor (1) comprises the following steps: a first step 1 of disposing a wiring (2) on one side surface in a thickness direction of a substrate, the wiring (2) having a substantially circular shape in cross section and including a lead (6) and an insulating layer (7) covering the lead (6); a2 nd step of disposing a1 st magnetic sheet (51) on one side surface in the thickness direction of the 1 st release sheet (41) so as to cover a major arc of the circumferential surface of the wiring (2), the 1 st magnetic sheet (51) containing 1 st magnetic particles and a1 st binder (91) for dispersing the 1 st magnetic particles; and a 4 th step of covering the major arc of the peripheral surface of the wiring (2) and one side surface of the 1 st release sheet (41) in the thickness direction of the 1 st magnetic sheet (51) by a2 nd magnetic sheet (52), the 2 nd magnetic sheet (52) containing the 2 nd magnetic particles and a2 nd binder (92) for dispersing the 2 nd magnetic particles.)

1. A method for manufacturing an inductor is characterized in that,

the manufacturing method of the inductor comprises the following steps:

a first step 1 of disposing a wiring having a substantially circular shape in cross section and including a lead and an insulating layer covering the lead on one surface in a thickness direction of a substrate in the first step;

a2 nd step of disposing a1 st magnetic sheet on one surface in the thickness direction of the substrate so as to cover a region exceeding 180 ° when viewed in cross section on the circumferential surface of the wiring, the 1 st magnetic sheet containing 1 st magnetic particles and a1 st binder for dispersing the 1 st magnetic particles; and

and a 4 th step of covering the region of the circumferential surface and the one side surface of the substrate with a2 nd magnetic sheet, the 1 st magnetic sheet having a thickness direction one side surface thereof, the 2 nd magnetic sheet including 2 nd magnetic particles and a2 nd binder for dispersing the 2 nd magnetic particles, the 2 nd magnetic particles including 2 nd anisotropic magnetic particles oriented in a plane direction.

2. The method of manufacturing an inductor according to claim 1,

the 1 st magnetic particle includes a1 st anisotropic magnetic particle oriented in a plane direction in the 1 st magnetic sheet.

3. The method of manufacturing an inductor according to claim 1,

the substrate is a release sheet that is,

the manufacturing method of the inductor further comprises the following steps:

a 3 rd step of removing the substrate in the 3 rd step; and

and a 5 th step of disposing a 3 rd magnetic sheet on the other side surface in the thickness direction of the 1 st magnetic sheet so as to cover a portion of the circumferential surface exposed from the other side surface in the thickness direction of the 1 st magnetic sheet, the 3 rd magnetic sheet including a 3 rd magnetic particle and a 3 rd binder for dispersing the 3 rd magnetic particle.

4. The method of manufacturing an inductor according to claim 3,

the 3 rd magnetic particle includes a 3 rd anisotropic magnetic particle oriented in a plane direction in the 3 rd magnetic sheet.

5. The method of manufacturing an inductor according to claim 3,

the 1 st step, the 2 nd step and the 3 rd step are sequentially performed, and then the 4 th step and the 5 th step are simultaneously performed.

6. The method of manufacturing an inductor according to claim 3,

the 1 st binder in the 2 nd step and the 3 rd binder in the 5 th step both contain a B-staged thermosetting component,

the method for manufacturing an inductor further includes a 6 th step of simultaneously changing the B-stage thermosetting component of the 1 st adhesive and the B-stage thermosetting component of the 3 rd adhesive into a C-stage in the 6 th step.

7. The method of manufacturing an inductor according to claim 1,

the substrate is a 3 rd magnetic sheet containing 3 rd magnetic particles and a 3 rd binder for dispersing the 3 rd magnetic particles,

the 3 rd binder contains a cured product of a thermosetting component.

8. The method of manufacturing an inductor according to claim 7,

the 3 rd magnetic particle includes a 3 rd anisotropic magnetic particle oriented in a plane direction in the 3 rd magnetic sheet.

Technical Field

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

Background

Conventionally, it is known that an inductor is mounted on an electronic device or the like and used as a passive element such as a voltage conversion member.

For example, an inductor is proposed, the inductor comprising: a rectangular parallelepiped substrate main body portion formed of a magnetic material; and an internal conductor such as copper embedded in the substrate main body (see patent document 1).

In patent document 1, an inductor is manufactured by laminating a plurality of conductor layers formed of a conductor paste by printing.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 10-144526

Disclosure of Invention

Problems to be solved by the invention

However, in recent years, higher inductance is required for inductors.

The invention provides a method for manufacturing an inductor with excellent inductance.

Means for solving the problems

The present invention (1) provides a method for manufacturing an inductor, wherein the method for manufacturing an inductor includes: a first step 1 of disposing a wiring having a substantially circular shape in cross section and including a lead and an insulating layer covering the lead on one surface in a thickness direction of a substrate in the first step; a2 nd step of disposing a1 st magnetic sheet on one surface in the thickness direction of the substrate so as to cover a region exceeding 180 ° when viewed in cross section on the circumferential surface of the wiring, the 1 st magnetic sheet containing 1 st magnetic particles and a1 st binder for dispersing the 1 st magnetic particles; and a 4 th step of covering the region of the circumferential surface and the one side surface of the substrate in the thickness direction of the 1 st magnetic sheet with a2 nd magnetic sheet, the 2 nd magnetic sheet including 2 nd magnetic particles and a2 nd binder for dispersing the 2 nd magnetic particles, the 2 nd magnetic particles including 2 nd anisotropic magnetic particles oriented in a plane direction.

In this method, in the 2 nd step, the 1 st magnetic sheet is disposed on one surface in the thickness direction of the substrate so as to cover a region exceeding 180 ° in a cross-sectional view of the peripheral surface of the wiring, and therefore the 1 st magnetic particles can be densely disposed. As a result, an inductor having excellent inductance can be manufactured.

In the 4 th step, the 2 nd magnetic sheet covers one side surface in the thickness direction of the 1 st magnetic sheet, and therefore, the 1 st magnetic particles and the 2 nd magnetic particles in the peripheral region of the wiring can be densely arranged. Therefore, an inductor having more excellent inductance can be manufactured.

Thus, with this manufacturing method, the arrangement of the 1 st magnetic particle and the 2 nd magnetic particle in the peripheral region can be made dense, and an inductor having excellent inductance can be manufactured.

The present invention (2) is the method for manufacturing an inductor according to (1), wherein the 1 st magnetic particle includes a1 st anisotropic magnetic particle oriented in a plane direction in the 1 st magnetic sheet.

In this method, in the 2 nd step, the 1 st magnetic sheet is disposed on one surface in the thickness direction of the substrate, and in the 1 st magnetic sheet, the 1 st anisotropic magnetic particles are oriented along one surface in the thickness direction of the substrate. Therefore, at the circumferential direction both end edges of the region facing the one thickness direction side face and being the wiring, the 1 st anisotropic magnetic particles can be suppressed from being oriented along the circumferential direction of the wiring, and therefore, the inductor is excellent in direct current superposition characteristics.

Further, since the 1 st magnetic sheet covers a region of more than 180 ° of the circumferential surface of the wiring, the 1 st anisotropic magnetic particles can be densely arranged with their orientation directions changed from the circumferential direction of the wiring to a direction along one side surface of the substrate at both circumferential edges of the region. As a result, an inductor having more excellent inductance can be manufactured.

Therefore, this method can produce an inductor having excellent inductance and dc superimposition characteristics.

The present invention (3) is the method for manufacturing an inductor according to (1) or (2), wherein the substrate is a release sheet, and the method for manufacturing an inductor further includes: a 3 rd step of removing the substrate in the 3 rd step; and a 5 th step of disposing a 3 rd magnetic sheet on the other side surface in the thickness direction of the 1 st magnetic sheet so as to cover a portion of the circumferential surface exposed from the other side surface in the thickness direction of the 1 st magnetic sheet, the 3 rd magnetic sheet containing a 3 rd magnetic particle and a 3 rd binder for dispersing the 3 rd magnetic particle.

In this method, since the 3 rd magnetic sheet is also arranged on the other side surface in the thickness direction of the 1 st magnetic sheet, the 1 st magnetic grains, the 2 nd anisotropic magnetic grains, and the 3 rd magnetic grains in the peripheral region of the wiring can be densely arranged. Therefore, an inductor having more excellent inductance can be manufactured.

In particular, since the 3 rd magnetic sheet covers the portion of the circumferential surface exposed from the other side surface in the thickness direction of the 1 st magnetic sheet, the 3 rd magnetic particles can be densely arranged in the region corresponding to the portion of the circumferential surface of the wiring exposed from the 1 st magnetic sheet. As a result, an inductor having excellent inductance can be manufactured.

The present invention (4) is the method for manufacturing an inductor according to (3), wherein the 3 rd magnetic particles include 3 rd anisotropic magnetic particles oriented in a plane direction in the 3 rd magnetic sheet.

With this method, in the 5 th step, the 3 rd anisotropic magnetic particles can be oriented and the 3 rd anisotropic magnetic particles can be densely arranged in the region corresponding to the portion of the circumferential surface of the wiring exposed from the 1 st magnetic sheet. As a result, an inductor having more excellent inductance can be manufactured.

The present invention (5) is the method for manufacturing an inductor according to (3) or (4), wherein the 1 st step, the 2 nd step, and the 3 rd step are sequentially performed, and then the 4 th step and the 5 th step are simultaneously performed.

In this method, since the 4 th step and the 5 th step are performed simultaneously, the manufacturing time can be shortened as compared with a method in which the 4 th step and the 5 th step are performed sequentially. Therefore, the inductor can be efficiently manufactured.

The present invention (6) is the method for manufacturing an inductor according to any one of (3) to (5), wherein the 1 st adhesive in the 2 nd step and the 3 rd adhesive in the 5 th step both contain a B-stage thermosetting component, and the method further includes a 6 th step of simultaneously changing the B-stage thermosetting component of the 1 st adhesive and the B-stage thermosetting component of the 3 rd adhesive into a C-stage in the 6 th step.

In the 6 th step of this method, the B-staged thermosetting component of the 1 st binder and the B-staged thermosetting component of the 3 rd binder are simultaneously converted to the C-staged, and therefore, the manufacturing time can be shortened as compared with a method in which the B-staged thermosetting component of the 1 st binder and the B-staged thermosetting component of the 3 rd binder are sequentially performed. Therefore, the inductor can be efficiently manufactured.

The present invention (7) is the method for manufacturing an inductor according to (1) or (2), wherein the substrate is a 3 rd magnetic sheet containing 3 rd magnetic particles and a 3 rd binder for dispersing the 3 rd magnetic particles, and the 3 rd binder contains a cured product of a thermosetting component.

In this method, since the substrate is the 3 rd magnetic sheet, a step of removing the substrate such as a release film is not necessary. Therefore, the number of steps can be reduced, and the inductor can be manufactured easily.

The present invention (8) is the method for manufacturing an inductor according to (7), wherein the 3 rd magnetic particles include 3 rd anisotropic magnetic particles oriented in a plane direction in the 3 rd magnetic sheet.

In this method, the 3 rd magnetic particle contains the 3 rd anisotropic magnetic particle oriented in the plane direction in the 3 rd magnetic sheet, and therefore, the 3 rd anisotropic magnetic particle can be oriented along a portion facing the 3 rd magnetic sheet in the wiring. Therefore, an inductor having more excellent inductance can be manufactured.

ADVANTAGEOUS EFFECTS OF INVENTION

The method for manufacturing the inductor can manufacture the inductor with excellent inductance.

Drawings

Fig. 1A to 1B are sectional views of an inductor according to embodiment 1 of the present invention, in which fig. 1A is a sectional view in which a cross section is shaded, and fig. 1B is a sectional view showing an orientation of anisotropic magnetic particles in a magnetic layer.

Fig. 2A to 2C are process diagrams for explaining a method of manufacturing an inductor according to embodiment 1, in which fig. 2A shows a1 st step of disposing a wiring on a1 st release sheet, fig. 2B shows a2 nd step of covering the wiring with a1 st magnetic sheet, and fig. 2C shows a 3 rd step of removing the 1 st release sheet.

Fig. 3D to 3F are process diagrams for explaining the method of manufacturing the inductor according to embodiment 1, following fig. 2C, fig. 3D shows a step of arranging the 2 nd magnetic sheet and the 3 rd magnetic sheet, fig. 3E shows the 4 th step of covering one side surface of the 1 st magnetic sheet with the 2 nd magnetic sheet and the 5 th step of covering the other side surface of the 1 st magnetic sheet at the B stage with the 3 rd magnetic sheet, and fig. 3F shows a step of taking out the inductor.

Fig. 4A to 4C are process diagrams for explaining a manufacturing method according to a modification of embodiment 1, in which fig. 4A shows a first step of disposing wiring on a1 st release sheet, fig. 4B shows a second step of covering the wiring with a1 st magnetic sheet, and fig. 4C shows a step of disposing a2 nd magnetic sheet.

Fig. 5D to 5F are process diagrams for explaining a manufacturing method according to a modification of embodiment 1, following fig. 4C, in which fig. 5D shows a 4 th step of covering one side surface of a1 st magnetic sheet with a2 nd magnetic sheet, fig. 5E shows a 3 rd step of removing the 1 st release sheet, and fig. 5F shows a step of disposing the 3 rd magnetic sheet.

Fig. 6G to 6H are process diagrams for explaining the manufacturing method of the modification of embodiment 1, following fig. 5F, in which fig. 6G shows the 5 th step of covering the other side surface of the 1 st magnetic piece at the B stage with the 3 rd magnetic piece, and fig. 6H shows the step of taking out the inductor.

Fig. 7A to 7B are sectional views of an inductor according to embodiment 2 of the present invention, fig. 7A is a sectional view in which a cross section is shaded, and fig. 7B is a sectional view showing an orientation of anisotropic magnetic particles in a magnetic layer.

Fig. 8A to 8C are process diagrams for explaining a method of manufacturing an inductor according to embodiment 2, in which fig. 8A shows a1 st step of disposing a wiring on a1 st release sheet, fig. 8B shows a2 nd step of covering the wiring with a1 st magnetic sheet, and fig. 8C shows a 3 rd step of removing the 1 st release sheet.

Fig. 9D to 9F are process diagrams for explaining the method of manufacturing the inductor according to embodiment 2, following fig. 8C, fig. 9D shows a process of arranging the 2 nd magnetic sheet and the 3 rd magnetic sheet, fig. 9E shows the 4 th process of covering one side surface of the 1 st magnetic sheet with the 2 nd magnetic sheet and the 5 th process of covering the other side surface of the 1 st magnetic sheet at the C stage with the 3 rd magnetic sheet, and fig. 9F shows a process of taking out the inductor.

Fig. 10A to 10C are process diagrams for explaining a manufacturing method according to a modification of embodiment 2, in which fig. 10A shows a first step of disposing wiring on a1 st release sheet, fig. 10B shows a second step of covering the wiring with a1 st magnetic sheet, and fig. 10C shows a step of disposing a2 nd magnetic sheet.

Fig. 11D to 11F are process diagrams for explaining a manufacturing method according to a modification of embodiment 2, following fig. 10C, in which fig. 11D shows a 4 th step of covering one side surface of a1 st magnetic sheet with a2 nd magnetic sheet, fig. 11E shows a 3 rd step of removing the 1 st release sheet, and fig. 11F shows a step of disposing the 3 rd magnetic sheet.

Fig. 12G to 12H are process diagrams for explaining a manufacturing method according to a modification of embodiment 2, as shown in fig. 11F, wherein fig. 12G shows a 5 th step of covering the other side surface of the 1 st magnetic piece at the C stage with a 3 rd magnetic piece, and fig. 12H shows a step of taking out an inductor.

Fig. 13A to 13C are process diagrams for explaining a manufacturing method according to a further modification of embodiment 2, in which fig. 13A shows a step of arranging wiring at a 3 rd magnetic stage, fig. 13B shows a step of covering the wiring and one side surface of the 3 rd magnetic sheet with a1 st magnetic sheet, and fig. 13C shows a step of arranging a2 nd magnetic sheet.

Fig. 14D to 14E are process views for explaining a manufacturing method according to a further modification of embodiment 2, following fig. 13C, in which fig. 14D shows a step of covering the 1 st magnetic sheet with the 2 nd magnetic sheet, and fig. 14E shows a step of taking out the inductor.

Fig. 15A to 15C are cross-sectional views of modifications of the inductor manufacturing method, fig. 15A showing a step of disposing a wiring on one side surface of a1 st release sheet via a pressure-sensitive adhesive layer, fig. 15B showing a step of covering a region exceeding 180 ° in cross-section on the circumferential surface of the wiring and one side surface of the 1 st magnetic sheet with a1 st magnetic sheet, and fig. 15C showing a step of obtaining an inductor.

Fig. 16A to 16C are cross-sectional views of modifications of the inductor manufacturing method, fig. 16A is a step of disposing a wiring with a gap with respect to a1 st release sheet, fig. 16B is a step of covering the circumferential surface of the wiring and one side surface of the 1 st magnetic sheet with the 1 st magnetic sheet, and fig. 16C shows a step of obtaining the inductor.

Fig. 17A to 17B are image processing diagrams of SEM photographs of example 1, fig. 17A is an SEM photograph after the 2 nd step, and fig. 17B is an SEM photograph of an inductor.

Fig. 18 is an image processing diagram of an SEM photograph of the inductor of example 2.

Fig. 19 is an image processing diagram of an SEM photograph of the inductor of comparative example 1.

Detailed Description

< embodiment 1 >

1. Inductor

An inductor according to embodiment 1 of the present invention will be described with reference to fig. 1A to 2B.

Further, fig. 1A is a cross section hatched and shows that fig. 1B is a cross sectional view showing the orientation of anisotropic magnetic particles in the magnetic layer. In addition, in the drawings of the present invention including fig. 1B, the shape, arrangement, and the like of the magnetic particles (including anisotropic magnetic particles) are exaggeratedly depicted for easy understanding of the present invention.

As shown in fig. 1A to 1B, the inductor 1 has a shape extending in the planar direction. Specifically, the inductor 1 has one side surface and the other side surface opposed to each other in the thickness direction, and both of these side surfaces have a flat shape along a direction included in the plane direction and in the 1 st direction orthogonal to both the direction (corresponding to the depth direction of the paper) in which the current is transmitted through the wiring 2 (described later) and the thickness direction.

The inductor 1 includes a wiring 2 and a 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 along a cross section (cross section in the 1 st direction) orthogonal to the 2 nd direction (the transport direction) (the paper depth direction) which is the direction in which current is transported.

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

The lead wire 6 is a conductor wire having a shape elongated in the 2 nd direction. The lead wire 6 has a substantially circular shape in cross section having a common central axis with the wiring 2.

Examples of the material of the lead wire 6 include metal conductors such as copper, silver, gold, aluminum, nickel, and alloys thereof, and copper is preferable. The lead wire 6 may have a single-layer structure or a multilayer structure in which a surface of a core conductor (e.g., copper) is plated with, for example, nickel.

The radius R1 of the lead 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 chemicals, water and prevents short-circuiting between the wire 6 and the magnetic layer 3. The insulating layer 7 covers the entire outer peripheral surface (entire circumferential surface) of the lead 6.

The insulating layer 7 has a substantially annular shape in cross section, sharing a central axis (center C) with the wiring 2.

Examples of the material of the insulating layer 7 include insulating resins such as polyvinyl formal, polyester, polyesterimide, polyamide (including nylon), polyimide, polyamideimide, and polyurethane. These may be used alone in 1 kind, or two or more kinds may be used in combination.

The insulating layer 7 may be formed of a single layer or a plurality of layers.

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

The ratio (R1/R2) of the radius R1 of the wire 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 (i.e., the radius R1 of the lead 6 + the thickness R2 of the insulating layer 7) 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 magnetic layer 3 increases the inductance of the inductor 1. The magnetic layer 3 covers the entire outer peripheral surface (entire circumferential surface) of the wiring 2. The magnetic layer 3 forms the outer shape of the inductor 1. Specifically, the magnetic layer 3 has a rectangular shape extending in the planar direction (1 st direction and 2 nd direction). More specifically, the magnetic layer 3 has one side surface and the other side surface opposed to each other in the thickness direction, and the one side surface and the other side surface of the magnetic layer 3 form one side surface and the other side surface of the inductor 1, respectively.

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 body of a thermosetting resin composition (composition containing the anisotropic magnetic particles 8 and a thermosetting component described later).

Examples of the magnetic material constituting the anisotropic magnetic particles 8 include soft magnetic bodies and hard magnetic bodies. From the viewpoint of inductance, a soft magnetic body is preferably used.

Examples of the soft magnetic material include a single metal material containing 1 metal element in a pure state, and an alloy material which is a eutectic (mixture) of 1 or more metal elements (1 st metal element) and 1 or more metal elements (2 nd metal element) and/or nonmetal elements (carbon, nitrogen, silicon, phosphorus, and the like). They can be used alone or in combination.

As the single metal body, for example, a simple metal composed of only 1 metal element (the 1 st metal element) is exemplified. The 1 st metal element is appropriately selected from, for example, iron (Fe), cobalt (Co), nickel (Ni), and metal elements that can be contained as the 1 st metal element of the soft magnetic body.

Examples of the single metal body include a form having a core containing only 1 metal element and a surface layer containing an inorganic substance and/or an organic substance which modifies part or all of the surface of the core, and forms after decomposition (thermal decomposition or the like) of an organic metal compound containing the 1 st metal element, an inorganic metal compound, and the like. More specifically, the latter form includes iron powder (may be referred to as carbonyl iron powder) obtained by thermally decomposing an organic iron compound (specifically, carbonyl iron) containing iron as the 1 st metal element, and the like. The position of the layer having an inorganic substance and/or organic substance that modifies only a portion containing 1 type of metal element is not limited to the surface described above. The organometallic compound and the inorganic metal compound that can obtain a single metal body are not particularly limited, and can be appropriately selected from known or conventional organometallic compounds and inorganic metal compounds that can obtain a single metal body of a soft magnetic body.

The alloy body is a eutectic of 1 or more metal elements (1 st metal element) and 1 or more metal elements (2 nd metal element) and/or nonmetal elements (carbon, nitrogen, silicon, phosphorus, and the like), and is not particularly limited as long as it can be used as an alloy body of a soft magnetic body.

The 1 st metal element is an essential element in the alloy body, and examples thereof include iron (Fe), cobalt (Co), nickel (Ni), and the like. In addition, if the 1 st metal element is Fe, the alloy body is an Fe-based alloy, if the 1 st metal element is Co, the alloy body is a Co-based alloy, and if the 1 st metal element is Ni, the alloy body is an Ni-based alloy.

The 2 nd metal element is an element (subcomponent) contained In the alloy body as a minor component and is a metal element that is compatible with (Co-melted with) the 1 st metal element, and examples thereof include iron (Fe) (when the 1 st metal element is other than Fe), cobalt (Co) (when the 1 st metal element is other than Co), nickel (Ni) (when the 1 st metal element is 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. They can be used alone or in combination of two or more.

The nonmetal element is an element (subcomponent) which is contained in the alloy body in a minor proportion and is compatible with (co-melted with) the 1 st metal element, and examples thereof include boron (B), carbon (C), nitrogen (N), silicon (Si), phosphorus (P), and sulfur (S). They can be used alone or in combination of two or more.

Examples of Fe-based alloys as an alloy body include magnetic stainless steel (Fe-Cr-Al-Si alloy) (including electromagnetic stainless steel), ferrosilicon-aluminum alloy (Fe-Si-Al alloy) (including super ferrosilicon-aluminum alloy), permalloy (Fe-Ni alloy), Fe-Ni-Mo alloy, Fe-Ni-Mo-Cu alloy, Fe-Ni-Co alloy, Fe-Cr-Al alloy, Fe-Ni-Cr-Si alloy, copper-silicon alloy (Fe-Cu-Si alloy), Fe-Si alloy, Fe-Si-B (-Cu-Nb) alloy, Fe-B-Si-Cr alloy, Fe-Si-Cr-Ni alloy, Fe-Cr-Si-Si alloy, Fe-Si-Si alloy, Fe-Si-alloy, alloys, and alloys, 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, and soft ferrite such as Mn-Mg ferrite, Mn-Zn ferrite, Ni-Zn-Cu ferrite, Cu-Zn ferrite, Cu-Mg-Zn ferrite), Permitron-Fe-Co-based high-permeability alloy (Fe-Co alloy), Fe-Co-V alloy, Fe-based amorphous alloy, etc.

Examples of the Co-based alloy as an alloy body include Co-Ta-Zr and a cobalt (Co) -based amorphous alloy.

Examples of the Ni-based alloy as an alloy body include Ni — Cr alloys and the like.

Among these soft magnetic materials, an alloy body is preferable, an Fe-based alloy is more preferable, and an iron-silicon-aluminum alloy (Fe — Si — Al alloy) is further preferable in view of magnetic properties. In addition, the soft magnetic material preferably includes a single metal body, more preferably a single metal body containing an iron element in a pure state, and further preferably a simple substance of iron or an iron powder (carbonyl iron powder).

The shape of the anisotropic magnetic particles 8 is, for example, a flat shape (plate shape), a needle shape, or the like from the viewpoint of anisotropy, and a flat shape is preferable from the viewpoint of good relative magnetic permeability in the planar direction (two-dimensional).

The flatness factor (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 flattening ratio is calculated as, for example, a ratio of the average particle diameter (average length) (described later) of the anisotropic magnetic particles 8 to 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 is, for example, 200 μm or less, preferably 150 μm or less. When the anisotropic magnetic particles 8 are flat, the average thickness thereof is, for example, 0.1 μm or more, preferably 0.2 μm or more, and is, 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 binder 9 is dispersed in the magnetic layer 3 in a predetermined direction. Preferably, the binder 9 contains a cured product of a B-stage thermosetting component. In the following description of the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 3 rd magnetic sheet 53 in the manufacturing method, the adhesive 9 will be described in detail.

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

The magnetic layer 3 has a peripheral region 4 and an outer region 5 in a cross-sectional view (when the cross-sectional view is taken in the 1 st direction).

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

The peripheral region 4 includes a1 st region 11 and a2 nd region 12.

Two of the 1 st regions 11 are arranged in the peripheral region 4 at a distance from each other in the circumferential direction. Specifically, the 1 st region 11 includes a 3 rd region 13 and a 4 th region 14 disposed on the other side in the thickness direction at a distance from the 3 rd region 13.

The 3 rd region 13 covers at least the outer peripheral arc surface including the one end edge E1 in the thickness direction of the wiring 2, for example, at least a part or the whole of the 1 st semicircular arc surface (one semicircular arc connecting the two end edges E2 and E3 in the 1 st direction of the wiring 2 on the one side in the thickness direction of the wiring 2) 23 including the one end edge E1 in the thickness direction of the wiring 2. Preferably, the 3 rd region 13 covers a part of the 1 st semi-circular arc surface 23 of the wiring 2, and more specifically, when projected in the radial direction, the 3 rd region 13 is included in one semi-circular arc surface of the wiring 2, and the 3 rd region 13 is disposed inside the 1 st direction both end edges E2 and E3 without overlapping the 1 st direction both end edges E2 and E3 of the wiring 2.

The one end edge E1 in the thickness direction of the wiring 2 is a portion where the arc surface (the 1 st semi-arc surface 23) on one side in the thickness direction of the wiring 2 intersects with the 1 st virtual line L1 passing through the center C of the wiring 2 in the thickness direction.

The 1 st-direction both end edges E2 and E3 of the wiring 2 are two portions where the circumferential surface of the wiring 2 intersects with the 3 rd virtual line L3 passing through the center C of the wiring 2 along the 1 st direction.

The 4 th region 14 is disposed opposite to the 3 rd region 13 with the center C of the wiring 2 interposed therebetween. The 4 th region 14 covers at least a portion of an outer peripheral arc surface including the other end edge E4 in the thickness direction of the wiring 2, for example, a2 nd semicircular arc surface (the other semicircular arc connecting the both end edges E2 and E3 in the 1 st direction on the other side in the thickness direction of the wiring 2) 24 including the other end edge E4 in the thickness direction of the wiring 2. Specifically, the 4 th region 14 is included in the 2 nd semi-circular arc surface 24 of the wiring 2 when projected in the radial direction, and the 4 th region 14 is disposed inside the 1 st direction both end edges E2 and E3 of the wiring 2 without overlapping the 1 st direction both end edges E2 and E3 of the wiring 2.

The other end edge E4 in the thickness direction of the wiring 2 is a portion where the 2 nd arc surface 24 intersects with a1 st imaginary line L1 passing through the center C of the wiring 2 along the thickness direction.

The angle α 1 of the center angle C1 of the 3 rd region 13 and the angle α 2 of the center angle C2 of the 4 th region 14 are appropriately set according to the application and purpose, respectively, and the total angle (α 1+ α 2) thereof is, for example, less than 360 °, preferably 270 ° or less, and, for example, exceeds 180 °, preferably 200 ° or more.

Specifically, the angle α 1 of the center angle C1 of the 3 rd 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. In addition, the angle α 1 is preferably an obtuse angle.

The angle α 2 of the central angle C2 of the 4 th region 14 is, for example, 15 ° or more, further, for example, 60 ° or less, and preferably 45 ° or less. In addition, the angle α 2 is preferably an acute angle.

The angle α 1 of the center angle C1 of the 3 rd region 13 is larger than the angle α 2 of the center angle C2 of the 4 th region 14, and the ratio (angle α 1/angle α 2) thereof exceeds 1, preferably 1.5 or more, and is 3 or less, preferably 2 or less, for example.

In this 1 st region 11, the anisotropic magnetic particles 8 are oriented along the circumferential direction of the wiring 2.

In each of the 3 rd region 13 and the 4 th region 14, the direction in which the relative permeability of the anisotropic magnetic particles 8 is high (for example, if the anisotropic magnetic particles 8 are flat, the plane direction of the anisotropic magnetic particles 8) substantially coincides with the circumferential direction. Specifically, the case where the angle formed by the plane direction of the anisotropic magnetic particles 8 and the tangent line that is radially inward and tangent to the circumferential surface of the anisotropic magnetic particles 8 is 15 degrees or less is defined as the case where the anisotropic magnetic particles 8 are oriented in the circumferential direction.

The ratio of the number of anisotropic magnetic particles 8 oriented in the circumferential direction to the number of anisotropic magnetic particles 8 contained in the 1 st region 11 as a whole exceeds 50%, preferably 70% or more, and more preferably 80% or more. That is, in the 1 st region 11, less than 50% of the anisotropic magnetic particles 8 that are not oriented in the circumferential direction may be contained, preferably 30% or less of the anisotropic magnetic particles 8 that are not oriented in the circumferential direction may be contained, and more preferably 20% or less of the anisotropic magnetic particles 8 that are not oriented in the circumferential direction may be contained.

The ratio of the area of the 1 st region 11 (the total area of the 3 rd region 13 and the 4 th region 14) to the area of the entire peripheral region 4 is, for example, 40% or more, preferably 50% or more, more preferably 60% or more, and further, for example, 90% or less, preferably 80% or less.

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

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

The 2 nd region 12 is a circumferential non-oriented region in which the anisotropic magnetic particles 8 are not oriented in the circumferential direction of the wiring 2. In other words, in the 2 nd region 12, the anisotropic magnetic particles 8 are not oriented or are oriented in a direction (for example, the 1 st direction, the radial direction) other than the circumferential direction of the wiring 2.

Two of the 2 nd regions 12 are arranged in the peripheral region 4 at a distance from each other in the circumferential direction. Specifically, the 2 nd region 12 includes a 5 th region 15 and a 6 th region 16 which are arranged at a distance from each other so as to sandwich the 1 st virtual straight line L1 passing through the one end edge E1 and the other end edge E2 in the thickness direction of the wiring 2.

The 5 th region 15 is disposed on the 1 st direction side with respect to the 1 st virtual straight line L1. The 5 th region 15 is sandwiched by one circumferential end surface of the 3 rd region 13 and the other circumferential end surface of the 4 th region 14, and specifically, the 5 th region 15 is continuous with the one circumferential end surface of the 3 rd region 13 and the other circumferential end surface of the 4 th region 14, respectively.

The 6 th region 16 is disposed opposite to the other side in the 1 st direction with a space from the 5 th region 15. The 6 th region 16 is disposed on the other side in the 1 st direction with respect to the 1 st virtual straight line L1, and the 6 th region 16 is line-symmetrical with respect to the 5 th region 15 about the 1 st virtual straight line L1. That is, the 6 th region 16 is continuous with the other end surface in the circumferential direction of the 3 rd region 13 and the one end surface in the circumferential direction of the 4 th region 14, respectively.

Thus, in the 1 st region 11, the 3 rd region 13, the 5 th region 15, the 4 th region 14, and the 6 th region 16 are arranged in this order in the circumferential direction.

The center C of the wiring 2 does not exist on the 2 nd virtual straight line L2 which is an example of a virtual straight line, the 2 nd virtual straight line L2 connects the center C3 of the 1 st virtual arc a1 which is an example of a virtual arc and the center C4 of the 2 nd virtual arc a2 which is an example of a virtual arc, the 1 st virtual arc a1 connects the 1 st end E5 which is one end in the circumferential direction and the 2 nd end E6 which is the other end in the circumferential direction in the 5 th region 15, and the 2 nd virtual arc 2 connects the 3 rd end E7 which is one end in the circumferential direction and the 4 th end E8 which is the other end in the circumferential direction in the 6 th region 16.

The 1 st end E5 is a portion located at the radial center of the first circumferential end surface in the 5 th region 15. The 2 nd end E6 is a portion located at the radial center of the other end surface in the circumferential direction in the 5 th region 15. The 3 rd end E7 is a portion located at the radially central portion of one end surface in the circumferential direction in the 6 th region 16. The 4 th end E8 is a portion located at the radial center of the other end surface in the circumferential direction in the 6 th region 16.

Specifically, the center C of the wiring 2 is disposed on the 1 st direction side of the 2 nd virtual straight line L2 so as to be spaced apart from the 2 nd virtual straight line L2.

More specifically, the center C of the wiring 2 is located at a position corresponding to a distance of 0.2 times or more and 0.7 times or less the radius R of the wiring 2 from the 2 nd virtual straight line L2 on the thickness direction side, and preferably located at a position corresponding to a distance of 0.3 times or more and 0.5 times or less the radius R of the wiring 2 from the 2 nd virtual straight line L2 on the thickness direction side.

The other end edge E4 in the thickness direction of the wiring 2 is not present on the 2 nd virtual straight line L2, and specifically, the other end edge E4 in the thickness direction of the wiring 2 is located on the other side in the thickness direction of the 2 nd virtual straight line L2 so as to be spaced apart from the 2 nd virtual straight line L2.

In the 2 nd region 12 (each of the 5 th region 15 and the 6 th region 16), an intersection (top portion) 20 is formed by at least two kinds of anisotropic magnetic particles 8 having different orientation directions. For example, in the 5 th region 15, the 1 st grains 17 as the anisotropic magnetic grains 8 oriented radially outward of the wiring 2 as going from the 1 st end E5 (the portion in contact with the 3 rd region 13) toward the 2 nd end E6 (the portion in contact with the 4 th region 14) and the 2 nd grains 18 as the anisotropic magnetic grains 8 oriented in the 1 st direction as going from the 2 nd end E6 toward the 1 st end E5 constitute at least two sides of a substantially triangular shape, thereby forming the 1 st intersections (1 st tops) 21. Specifically, the 1 st particle 17 and the 2 nd particle 18 form a substantially triangular shape (preferably an acute triangular shape) together with the 3 rd particle 19 as the anisotropic magnetic particle 8 oriented in the circumferential direction in the region closest to the wiring 2 in the 5 th region 15.

In addition, in the 6 th region 16, the 1 st grains 17 as the anisotropic magnetic grains 8 oriented radially outward of the wiring 2 as going from the 4 th end E8 (the portion in contact with the 3 rd region 13) toward the 3 rd end E7 (the portion in contact with the 4 th region 14) and the 2 nd grains 18 as the anisotropic magnetic grains 8 oriented in the 1 st direction as going from the 3 rd end E7 toward the 4 th end E8 constitute at least two sides of a substantially triangular shape, thereby forming the 2 nd intersection (2 nd top) 22. Specifically, the 1 st particle 17 and the 2 nd particle 18 form a substantially triangular shape (preferably an acute triangular shape) together with the 3 rd particle 19 as the anisotropic magnetic particle 8 oriented in the circumferential direction in the region closest to the wiring 2 in the 6 th region 16.

When projected in the 1 st direction, the intersection 20 (the 1 st intersection 21 and the 2 nd intersection 22, respectively) does not overlap the center C of the wiring 2. Specifically, when projected in the 1 st direction, the intersection 20 is disposed on the other side in the thickness direction than the center C of the wiring 2 so as to be spaced apart from the center C of the wiring 2.

When projected in the 1 st direction, the intersection 20 is disposed on the thickness direction side of the other end edge E4 of the wiring 2 so as to be spaced apart from the other end edge E4 of the wiring 2 in the thickness direction.

In the 2 nd region 12 (the 5 th region 15 and the 6 th region 16), the direction in which the relative 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) does not coincide with the tangent line of the circumferential surface centered on the center C of the wiring 2. More specifically, a case where the angle formed by 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 are located exceeds 15 degrees is defined as a case where the anisotropic magnetic particles 8 are not oriented in the circumferential direction.

The ratio of the number of anisotropic magnetic particles 8 that are not oriented in the circumferential direction to the number of the entire anisotropic magnetic particles 8 included in the 2 nd region 12 is, for example, more than 50%, preferably 70% or more, and, for example, 95% or less, preferably 90% or less.

In the 2 nd region 12, for example, anisotropic magnetic particles 8 oriented in the circumferential direction may also be contained. The ratio of the number of anisotropic magnetic particles 8 oriented in the circumferential direction to the number of the entire anisotropic magnetic particles 8 included in the 2 nd region 12 is, for example, less than 50%, preferably 30% or less, and, for example, 5% or more, preferably 10% or more.

In addition, when the anisotropic magnetic particles 8 oriented in the circumferential direction are included, the anisotropic magnetic particles 8 oriented in the circumferential direction are preferably arranged in the innermost region of the 2 nd region 12, that is, in the vicinity of the surface of the wiring 2.

The ratio of the area of the 2 nd region 12 (the total area of the 5 th region 15 and the 6 th region 16) to the area of the entire peripheral region 4 is, for example, 10% or more, preferably 20% or more, and further, for example, 60% or less, preferably 50% or less, and more preferably 40% or less.

In the peripheral region 4, the filling ratio (existing ratio) of the anisotropic magnetic particles 8 is, for example, 40 vol% or more, preferably 45 vol% or more, more preferably 50 vol% or more, further preferably 55 vol% or more, and particularly preferably 60 vol% or more. If the filling ratio of the anisotropic magnetic particles 8 in the peripheral region 4 is equal to or higher than the lower limit, the inductor 1 having excellent inductance can be obtained.

The filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 is, for example, 95 vol% or less, and preferably 90 vol% or less. If the filling ratio of the anisotropic magnetic particles 8 is not more than the above upper limit, the inductor 1 has excellent mechanical strength.

In particular, in each of the 1 st region 11 and the 2 nd region 12, the filling rate of the anisotropic magnetic particles 8 is, for example, 40 vol% or more, preferably 45 vol% or more, more preferably 50 vol% or more, further preferably 55 vol% or more, particularly preferably 60 vol% or more, and is, for example, 95 vol% or less, preferably 90 vol% or less.

The filling ratio of the anisotropic magnetic particles 8 in the 1 st region 11 and the filling ratio of the anisotropic magnetic particles 8 in the 2 nd region 12 may be the same or different.

The filling ratio of the anisotropic magnetic particles 8 can be calculated by measurement of actual specific gravity, binarization of an SEM photograph, or the like.

On the other hand, the existence ratio of the binder 9 in the peripheral region 4 is, for example, the remaining part of the above-described filling ratio of the anisotropic magnetic particles 8.

In the peripheral region 4, formation of voids (voids, gaps) is suppressed as much as possible, and it is preferable that no voids are present 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 region 5 is disposed outside the peripheral region 4 so as to be continuous with the peripheral region 4.

In the outer region 5, the anisotropic magnetic particles 8 are oriented in the plane direction (particularly, the 1 st direction).

In the outer region 5, the direction in which the relative 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) substantially coincides with the 1 st direction. More specifically, the case where the angle formed by the plane direction of the anisotropic magnetic particles 8 and the 1 st direction is 15 ° or less is defined as the anisotropic magnetic particles 8 being oriented in the 1 st direction.

In the outer region 5, the ratio of the number of anisotropic magnetic particles 8 oriented in the 1 st direction to the number of the entire anisotropic magnetic particles 8 included in the outer region 5 exceeds 50%, preferably 70% or more, and more preferably 90% or more. That is, in the outer region 5, less than 50% of the anisotropic magnetic particles 8 not oriented in the 1 st direction may be contained, preferably 30% or less of the anisotropic magnetic particles 8 not oriented in the 1 st direction may be contained, and more preferably 10% or less of the anisotropic magnetic particles 8 not oriented in the 1 st direction may be contained.

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

The filling ratio of the anisotropic magnetic particles 8 in the outer region 5 is not particularly limited, and is, for example, 40 vol% or more, preferably 45 vol% or more, more preferably 50 vol% or more, further preferably 55 vol% or more, particularly preferably 60 vol% or more, and further, for example, 95 vol% or less, preferably 90 vol% or less.

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

2. Method for manufacturing inductor

A method for manufacturing the inductor 1 will be described with reference to fig. 2A to 3F.

The method for manufacturing the inductor 1 includes steps 1 to 6. In the method for manufacturing the inductor 1, the 1 st step, the 2 nd step and the 3 rd step are sequentially performed, and then the 4 th step, the 5 th step and the 6 th step are simultaneously performed.

(step 1)

As shown in fig. 2A, in the 1 st step, first, the wiring 2 and the 1 st release sheet 41 as a release film, which is an example of a substrate, are prepared.

The 1 st release sheet 41 has a substantially sheet shape extending in the planar direction. The material of the 1 st release sheet 41 is appropriately selected depending on the application and purpose thereof, and specifically, for example, polyester such as polyethylene terephthalate (PET), polyolefin such as polymethylpentene and polypropylene, and the like are exemplified. Further, one side surface and/or the other side surface in the thickness direction of the 1 st release sheet 41 may be subjected to release treatment. The thickness of the 1 st release sheet 41 is, for example, 1 μm or more and, for example, 1000 μm or less.

Thereafter, in the 1 st step, the wiring 2 and the 1 st release sheet 41 are arranged on the platen press 42.

The platen press 42 includes a1 st plate 43 and a2 nd plate 44 capable of pressing in the thickness direction. In the platen press 42, the 2 nd plate 44 is disposed on one side in the thickness direction of the 1 st plate 43 so as to be opposed to the 1 st plate 43 with a gap therebetween. Further, the platen press 42 includes a heat source not shown.

The platen press 42 is provided with a chamber for placing a member for pressing, which is disposed in the platen press 42, in a vacuum state.

In the 1 st step, first, the 1 st release sheet 41 is disposed on the 1 st plate 43, and then the wiring 2 is disposed on one surface of the 1 st 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 side surface of the 1 st release sheet 41.

In this case, the 1 st release sheet 41 and the 1 st plate 43 are disposed in the chamber. Each member disposed in the subsequent step is disposed in the chamber.

(step 2)

In the 2 nd step, first, as shown in fig. 2A, the 1 st magnetic sheet 51 is prepared. Simultaneously, the 2 nd release sheet 45 and the release pad 46 are prepared.

[ 1 st magnetic sheet ]

The 1 st magnetic sheet 51 has a substantially sheet shape extending in the planar direction. Specifically, the 1 st magnetic sheet 51 has one side surface and the other side surface opposed to each other in the thickness direction.

The 1 st magnetic sheet 51 is a magnetic sheet for forming at least (part or all of) the 2 nd region 12, the 3 rd region 13, and part of the outer region 5 of the magnetic layer 3.

The 1 st magnetic sheet 51 is deformed (fluidized) by the hot pressing in the 2 nd step (see fig. 2B).

In addition, the 1 st magnetic sheet 51 contains the 1 st anisotropic magnetic particles 81 as an example of the 1 st magnetic particles and the 1 st binder 91. The 1 st anisotropic magnetic particle 81 is the same as the anisotropic magnetic particle 8. Specifically, the 1 st magnetic sheet 51 is formed in a substantially sheet shape from the 1 st magnetic composition containing the 1 st anisotropic magnetic particles 81 and the 1 st binder 91.

In the 1 st magnetic sheet 51, the 1 st anisotropic magnetic particles 81 are uniformly dispersed by the 1 st binder 91 so as to be oriented in the planar direction.

The 1 st magnetic sheet 51 is a single sheet or a laminate (laminate sheet) of a plurality of sheets, preferably a laminate sheet, more preferably a two-layer sheet composed of an inner sheet 54 which comes into contact with the wiring 2 at the time of hot pressing and an outer sheet 55 which is disposed on one side of the inner sheet 54 in the thickness direction.

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

The volume ratio of the 1 st anisotropic magnetic particles 81 in the 1 st magnetic composition (1 st magnetic sheet 51) may be, for example, 40 vol% or less, further 35 vol% or less, further 20 vol% or more, further 25 vol% or more. If the volume ratio of the 1 st anisotropic magnetic particles 81 is within the above range, the presence of voids in the peripheral region 4 can be suppressed as much as possible, and therefore, the 1 st anisotropic magnetic particles 81 can be densely arranged together with the 2 nd anisotropic magnetic particles 82 and the 3 rd anisotropic magnetic particles 83 (described later) in the peripheral region 4. As a result, the inductor 1 having excellent inductance can be obtained.

If the 1 st magnetic sheet 51 is a two-layer laminate composed of an inner sheet 54 and an outer sheet 55, the volume ratio of the anisotropic magnetic particles 8 of the outer sheet 55 is preferably higher than the volume of the anisotropic magnetic particles 8 of the inner sheet 54. With this arrangement, the 1 st magnetic sheet 51 can more flexibly follow a region (hereinafter referred to as a "major arc") exceeding 180 ° when viewed in cross section on the circumferential surface of the wiring 2.

The 1 st adhesive 91 is, for example, a thermoplastic component such as an acrylic resin, or a thermosetting component such as an epoxy resin composition. The acrylic resin includes, for example, a carboxyl group-containing acrylate copolymer. The epoxy resin composition contains, for example, an epoxy resin (e.g., cresol novolac type epoxy resin) as a main component, a curing agent for epoxy resin (e.g., phenol resin), and a curing accelerator for epoxy resin (e.g., imidazole compound).

The 1 st adhesive 91 may be composed of a thermoplastic component and a thermosetting component alone or in combination, preferably a thermoplastic component and a thermosetting component.

That is, it is preferable that the 1 st adhesive 91 contains at least a thermosetting component. If the 1 st adhesive 91 contains at least a thermosetting component, the 1 st magnetic sheet 51 can be made to be a B-stage having fluidity so that the 1 st anisotropic magnetic particles 81 can be uniformly dispersed at a high mixing ratio, and the 1 st magnetic sheet 51 can be flexibly deformed and covered so as to follow the major arc of the circumferential surface of the wiring 2 in the hot pressing in the 2 nd step.

Further, a more detailed formulation of the 1 st binder 91 (1 st magnetic composition) is described in japanese patent application laid-open publication No. 2014-165363 and the like.

The volume ratio of the 1 st binder 91 in the 1 st magnetic composition (1 st magnetic sheet 51) is the remainder of the volume ratio of the above-described magnetic particles 48.

In the production of the 1 st magnetic sheet 51, the 1 st anisotropic magnetic particles 81 and the 1 st binder 91 are mixed and uniformly mixed to prepare a1 st magnetic composition. At this time, a varnish of the 1 st magnetic composition was prepared using a solvent (organic solvent) as needed. Then, the varnish was applied to a release film not shown and dried to produce the 1 st magnetic sheet 51.

The thickness (total thickness in the case of a laminated sheet) of the 1 st magnetic sheet 51 is set as appropriate so that the shape of the outer region 5 that can cover at least the one end edge E1 in the thickness direction of the wiring 2 can be maintained under the hot pressing in the 2 nd step. Specifically, the thickness of the 1 st magnetic sheet 51 is, for example, 3 times or less, preferably two times or less, more preferably less than two times, further preferably 1.5 times or less, particularly preferably 1.25 times or less, and further, for example, 0.1 times or more, preferably 0.2 times or more the radius R of the wiring 2.

(No. 2 Release sheet)

The 2 nd release sheet 45 has the same structure as the 1 st release sheet 41, and the material thereof can be appropriately selected from the above materials according to the use and purpose.

(Release liner)

The release pad 46 is a release sheet capable of releasing the 1 st magnetic sheet 51 from the 2 nd plate 44 after hot pressing in the 2 nd step (see fig. 2C) described below.

The release liner 46 is also a liner for causing the release liner 46 to distribute and apply the pressure of the 2 nd plate 44 to the 1 st magnetic sheet 51 in accordance with the shape of the major arc of the circumferential surface of the wiring 2 at the time of hot pressing in the 2 nd step (see fig. 2B), and to deform the 1 st magnetic sheet 51 so that the 1 st magnetic sheet 51 follows the major arc of the circumferential surface of the wiring 2.

The knock out pad 46 has a sheet shape extending in the face direction, and has one side surface and the other side surface in the thickness direction.

In the 2 nd step, one side surface of the release liner 46 can be in planar contact with the 2 nd plate 44 (described later). One side surface of the knock out pad 46 is a flat surface along the surface direction.

The other side surface of the release liner 46 is in contact with one side surface in the thickness direction of the 2 nd release sheet 45, and can deform the 1 st magnetic sheet 51. The other side surface of the release liner 46 is disposed opposite to the other side surface in the thickness direction with a space from the one side surface of the release liner 46. The other side surface of the knock out pad 46 is a flat surface parallel to and in the plane direction with respect to one side surface of the knock out pad 46.

The release liner 46 includes a1 st layer 47, a2 nd layer 48, and a 3 rd layer 49 in this order toward one side in the thickness direction.

(layer 1)

The 1 st layer 47 is a release layer (1 st release layer) with respect to the 1 st magnetic sheet 51. The 1 st layer 47 is a film (outer film) having a shape extending in the plane direction. The 1 st layer 47 is a cover layer (outer shell layer) that covers the 2 nd layer 48 described below from the other side in the thickness direction. The other side surface of the 1 st layer 47 in the thickness direction may be subjected to an appropriate peeling treatment.

In the next hot pressing in the 2 nd step, the 1 st layer 47 can follow one side surface of the 1 st magnetic sheet 51 via the 2 nd release sheet 45, while the 1 st layer 47 has physical properties in which the thickness thereof does not substantially change before and after the hot pressing. The 1 st layer 47 is a layer that can be elongated in the planar direction (specifically, the 1 st direction) during hot pressing. The 1 st layer 47 is harder than the 2 nd layer 48 described below at the temperature (for example, 110 ℃) of the hot press in the 2 nd step.

The material of the 1 st layer 47 includes a non-heat-flowable material which flows in the 1 st direction under heat pressing in the 2 nd step described later.

The non-heat-flowable material contains, as a main component, an aromatic polyester such as polybutylene terephthalate (PBT), for example, a polyolefin.

(layer 2)

Layer 2 48 is an intermediate layer sandwiched between layer 1 and layer 3, 47. The 2 nd layer 48 is a fluidized layer which flows in the 1 st direction and the thickness direction at the time of hot pressing in the 1 st step, and causes the 1 st layer 47 to follow one side surface of the 1 st magnetic sheet 51.

The 2 nd layer 48 is a soft layer softer than the 1 st layer 47, and specifically, the 2 nd layer 48 can be deformed at the time of hot pressing in the 2 nd step. Specifically, the tensile storage elastic modulus E 'of the 2 nd layer 48 at 110 ℃ is lower than the tensile storage elastic modulus E' of the 1 st layer 47 at 110 ℃, for example.

The material of the 2 nd layer 48 is a heat-flowable material which flows in the 1 st direction and the thickness direction under heat pressing in the 2 nd step described later. The heat-flowable material contains, for example, an olefin- (meth) acrylate copolymer (ethylene-methacrylate copolymer or the like), an olefin-vinyl acetate copolymer, or the like as a main component.

(layer 3)

The 3 rd layer 49 is a release layer (2 nd release layer) with respect to the 2 nd plate 44. The shape, physical properties, materials and thickness of the 3 rd layer 49 are the same as the shape, physical properties, materials and thickness of the 1 st layer 47.

(thickness of Release liner)

The thickness of the release liner 46 is, for example, 50 μm or more and, for example, 500 μm or less. The thicknesses of the 1 st layer 47 and the 3 rd layer 49 are, for example, 5 μm or more and 50 μm or less, respectively, and the thickness of the 2 nd layer 48 is, for example, 30 μm or more and 300 μm or less, respectively. The ratio of the thickness of the 2 nd layer 48 to the thickness of the 1 st layer 47 is, for example, 2 or more, preferably 5 or more, more preferably 7 or more, and, for example, 15 or less.

As the release liner 46, commercially available products can be used, and for mutexample, a release film OT series (manufactured by Water chemical industries, Ltd.) such as a release film OT-A and a release film OT-E can be used.

Then, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release pad 46 are sandwiched in this order by the platen press 42.

Next, the wiring 2 and the 1 st magnetic sheet 51 are hot-pressed by the platen press 42 through the 1 st release sheet 41, the 2 nd release sheet 45, and the release pad 46.

For example, the 2 nd plate 44 is moved so as to approach the 1 st plate 43, and the 2 nd plate 44 is pressed (pressed) against the 1 st magnetic sheet 51 via the release pad 46 and the 2 nd release sheet 45.

At the same time, the 1 st magnetic sheet 51 and the release liner 46 are heated by the heat source.

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

The heating temperature is, specifically, for example, 100 ℃ or higher, preferably 105 ℃ or higher, and is, for example, 190 ℃ or lower, preferably 150 ℃ or lower.

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

In the 2 nd step, the chamber is closed by moving the 2 nd plate 44 relative to the 1 st plate 43, the atmosphere in the chamber is then brought into a vacuum state, and then the members adjacent in the thickness direction among the 1 st plate 43, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, the release gasket 46, and the 2 nd plate 44 are brought into contact with each other (close contact ), and then the 2 nd plate 44 is further moved (hot pressing is started).

Then, the overlapping portion 34 of the release liner 46, which overlaps the wiring 2 when projected in the thickness direction, is sandwiched and pressed (sandwiched) in the thickness direction by the 1 st semi-circular arc surface 23 of the wiring 2 and the 2 nd plate 44.

On the other hand, the non-overlapping portion 35 of the release liner 46 that does not overlap the wiring 2 when projected in the thickness direction is not subjected to the above-described nipping.

Then, the heat flowable material in the portion of the overlapping portion 34 that is the 2 nd layer 48 flows (is extruded) (is deformed) (in detail, is plastically deformed) toward the non-overlapping portion 35. Then, with respect to the non-overlapping portion 35, the flow pressure based on the flow (extrusion) of the heat flow material from the overlapping portion 34 described above is increased. The flow pressure at the non-overlapping portion 35 acts on both sides in the thickness direction.

Of the flow pressures, the flow pressure acting on the other side in the thickness direction pushes (presses) the portion of the non-overlapping portion 35 in the 1 st layer 47 toward the other side in the thickness direction, and pushes (presses) the pushed-out portion 38 of the 1 st magnetic sheet 51 facing the non-overlapping portion 35 in the thickness direction toward the other side in the thickness direction via the 1 st layer 47.

Thereafter, the extrusion (pressing) of the extruded portion 38 based on the above-described flow pressure is continued until the extruded portion 38 goes around the 1 st-direction both end edges E3, E4 of the wiring 2 and further covers (comes into contact with) the 2 nd arc surface 24 of the wiring 2 (except for the thickness-direction other end edge E4).

Then, the 2 nd area 12 is formed by the extruded portion 38 contacting the 2 nd circular arc surface 24 as shown in fig. 2B.

After the hot pressing, the other side surface of the release liner 46 has a shape corresponding to, for example, the 1 st semicircular arc surface 23 of the wiring 2.

The 2 nd release sheet 45 follows the other side surface of the release liner 46, specifically, the 1 st layer 47.

The 1 st magnetic sheet 51 after hot pressing is, for example, in the B stage. Specifically, the thermosetting component contained in the 1 st binder 91 of the 1 st magnetic sheet 51 is B-staged.

Thus, the 1 st magnetic sheet 51 after hot pressing has a shape including at least the 2 nd region 12. That is, as shown in the enlarged view of fig. 2B, in the 2 nd region 12, the anisotropic magnetic particles 8 are not oriented in the circumferential direction of the wiring 2.

In addition, the 1 st magnetic sheet 51 has the raised portion 25 and the 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 shape that is curved in cross section similar (or similar) to the 1 st semi-circular arc surface 23. The raised portion 25 has a shape in which the 1 st direction center protrudes (rises) toward one side in the thickness direction. The bulge 25 has 1 nd 2 nd crest 27.

The flat portions 26 have a substantially flat plate shape extending outward in the 1 st direction from both end surfaces in the 1 st direction of the ridge portion 25.

Thus, the 1 st magnetic sheet 51 is disposed on one side surface in the thickness direction of the 1 st release sheet 41 so as to cover the major arc of the peripheral surface of the wiring 2.

The major arc of the circumferential surface of the wiring 2 is the 1 st semi-arc surface 23 and the arc surface (part of the circumferential surface) which goes from both ends in the circumferential direction of the 1 st semi-arc surface 23 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.

The thickness of the 1 st magnetic sheet 51 after hot pressing is set so as to secure the shape having the ridge portion 25 and the flat portion 26. Specifically, the ratio of the thickness of the 1 st magnetic sheet 51 at the 2 nd top 27 to the radius R of the wiring 2 is, for example, 0.01 or more, preferably 0.03 or more, and is, 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, preferably 1.5 or less.

Specifically, the thickness of the 2 nd top portion 27 of the 1 st magnetic sheet 51 is, for example, 1 μm or more, preferably 5 μm or more, and is, for example, 200 μm or less, preferably 100 μm or less. The thickness of the flat portion 26 is, for example, 25 μm or more, preferably 50 μm or more, and is, for example, 200 μm or less, preferably 150 μm or less.

(step 3)

In the 3 rd step, first, the platen press 42 shown in fig. 2B is released from the pressing, and then the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release liner 46 are taken out of the platen press 42.

Next, as shown in fig. 2C, the 1 st release sheet 41 is peeled from the other side surface of the 1 st magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2.

Further, the 2 nd release sheet 45 and the release liner 46 are peeled off from one side surface of the 1 st magnetic sheet 51.

(step 4, step 5 and step 6)

As shown in fig. 3E, the 4 th step, the 5 th step and the 6 th step are performed simultaneously.

In the 4 th step, one side surface in the thickness direction of the 1 st magnetic sheet 51 is covered with the 2 nd magnetic sheet 52. In the 5 th step, the other side surface of the 1 st magnetic sheet 51 in the thickness direction is covered with the 3 rd magnetic sheet 53. In the 6 th step, the thermosetting component C of the 1 st adhesive 91 (see fig. 2A), the 2 nd adhesive 92 (see fig. 3D), and the 3 rd adhesive 93 (see fig. 3D) is staged.

As shown in fig. 3D, in the 4 th and 5 th steps, first, the 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53 are prepared.

The 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53 may have the same configuration as the 1 st magnetic sheet 51, respectively.

Further, the 2 nd magnetic sheet 52 contains the 2 nd anisotropic magnetic particles 82 and the 2 nd binder 92, and in the 2 nd binder 92, for example, the 2 nd anisotropic magnetic particles 82 are oriented in the plane direction. Since the thermosetting component contained in the 2 nd adhesive 92 is B-staged, the 2 nd magnetic sheet 52 is B-staged. In addition, when the 2 nd magnetic sheet 52 is a laminate (laminated sheet), the presence ratio of the 2 nd anisotropic magnetic particles 82 in each sheet is the same or different, preferably the same. In addition, the 2 nd anisotropic magnetic particles 82 may be present in the 2 nd magnetic sheet 52 in the same ratio as or in a different ratio from the 1 st anisotropic magnetic particles 81 in the 1 st magnetic sheet 51.

In the case where the ratio of the 2 nd anisotropic magnetic particles 82 to the 1 st anisotropic magnetic particles 81 is different and the ratio of the 1 st anisotropic magnetic particles 81 to be present is 40 vol% or less, the ratio of the 2 nd anisotropic magnetic particles 82 to be present can be set higher than the ratio of the 1 st anisotropic magnetic particles 81 to be present. Specifically, the ratio of the proportion of the 2 nd anisotropic magnetic particles 82 present in the 2 nd magnetic sheet 52 to the proportion of the 1 st anisotropic magnetic particles 81 present in the 1 st magnetic sheet 51 (the proportion of the 2 nd anisotropic magnetic particles 82 present in the 2 nd magnetic sheet 52/the proportion of the 1 st anisotropic magnetic particles 81 present in the 1 st magnetic sheet 51) is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more, and further, for example, 3 or less, preferably 2.5 or less. In this case, specifically, the presence ratio of the 2 nd anisotropic magnetic particles 82 in the 2 nd magnetic sheet 52 is, for example, 45 vol% or more, preferably 50 vol% or more, more preferably 55 vol% or more, further preferably 60 vol% or more, and further, for example, 95 vol% or less, preferably 90 vol% or less.

If the ratio and/or the existence ratio of the 2 nd anisotropic magnetic particles 82 are within the above range, the existence of voids between the 2 nd magnetic sheet 52 and the 1 st magnetic sheet 51 can be suppressed as much as possible, and therefore, the 1 st anisotropic magnetic particles 81 and the 2 nd anisotropic magnetic particles 82 can be densely arranged in the peripheral region 4. As a result, the inductor 1 having excellent inductance can be obtained.

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

The 3 rd magnetic sheet 53 contains the 3 rd anisotropic magnetic particles 83 as an example of the 3 rd magnetic particles and the 3 rd binder 93, and for example, in the 3 rd binder 93, the 3 rd anisotropic magnetic particles 83 are oriented in the plane direction. Since the thermosetting component contained in the 3 rd adhesive 93 is B-staged, the 3 rd magnetic sheet 53 is B-staged. In addition, when the 3 rd magnetic sheet 53 is a laminated body (laminated sheet), the presence ratio of the 3 rd anisotropic magnetic particles 83 in each sheet is the same or different, preferably the same. In addition, the 3 rd anisotropic magnetic particle 83 may be present in the 3 rd magnetic sheet 53 in the same ratio as or in a different ratio from the 1 st anisotropic magnetic particle 81 in the 1 st magnetic sheet 51.

In the case where the 3 rd anisotropic magnetic particle 83 is present at a ratio different from that of the 1 st anisotropic magnetic particle 81 and the 1 st anisotropic magnetic particle 81 is present at a ratio of 40 vol% or less, the 3 rd anisotropic magnetic particle 83 is present at a ratio higher than that of the 1 st anisotropic magnetic particle 81. Specifically, the ratio of the proportion of the 3 rd anisotropic magnetic particles 83 present in the 3 rd magnetic sheet 53 to the proportion of the 1 st anisotropic magnetic particles 81 present in the 1 st magnetic sheet 51 (the proportion of the 3 rd anisotropic magnetic particles 83 present in the 3 rd magnetic sheet 53/the proportion of the 1 st anisotropic magnetic particles 81 present in the 1 st 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 3 rd anisotropic magnetic particles 83 are present in the 3 rd magnetic sheet 53 in a proportion of, for example, 40 vol% or more, preferably 45 vol% or more, more preferably 50 vol% or more, further preferably 55 vol% or more, particularly preferably 60 vol% or more, and further, for example, 95 vol% or less, preferably 90 vol% or less.

If the ratio and/or the existence ratio of the 3 rd anisotropic magnetic particles 83 are within the above range, the existence of voids between the 3 rd magnetic sheet 53 and the 1 st magnetic sheet 51 can be suppressed as much as possible, and as a result, the 1 st anisotropic magnetic particles 81 and the 3 rd anisotropic magnetic particles 83 can be densely arranged in the peripheral region 4. Thus, the inductor 1 having excellent inductance can be obtained.

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

Next, the 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53 are disposed on the platen press 42. Specifically, between the 1 st plate 43 and the 2 nd plate 44, the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are arranged in this order toward one side in the thickness direction.

Further, the 1 st release sheet 41 and/or the 2 nd release sheet 45 removed in the above-described 3 rd step may be repeatedly used as the 1 st release sheet 41 and/or the 2 nd release sheet 45, or another 1 st release sheet 41 and/or the 2 nd release sheet 45 may be prepared and arranged.

In the hot pressing in the 4 th and 5 th steps, the release pad 46 used in the 2 nd step is not disposed in the platen press 42.

Next, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 are hot-pressed by the platen press 42. The hot pressing conditions are the same as those in the step 2.

The other side surface of the 2 nd magnetic sheet 52 follows the shape of the raised portion 25 of the 1 st magnetic sheet 51 by the heat pressing. However, one side surface of the 2 nd magnetic sheet 52 maintains its flat shape.

That is, the 2 nd magnetic sheet 52 covers the major arc of the peripheral surface of the wiring 2 and one side surface of the 1 st magnetic sheet 51 in the thickness direction of the 1 st releasing sheet 41 (step 4 is performed).

In addition, the other side surface of the 3 rd magnetic sheet 53 maintains its flat shape by the hot pressing.

On the other hand, the facing portion 28 of one side surface of the 3 rd magnetic piece 53, which faces the other end edge E4 in the thickness direction of the wiring 2, moves slightly (retreats, descends, or sinks) to the other side in the thickness direction. That is, on one side surface of the 3 rd magnetic sheet 53, the facing portion 28 moves outward in the 1 st direction thereof, and is slightly recessed on the thickness direction side with respect to the 2 nd flat portion 29 parallel to one side surface of the 1 st release sheet 41.

The other side surface of the 1 st magnetic sheet 51 is in close contact with the 2 nd flat portion 29 on one side surface of the 3 rd magnetic sheet 53, and the other side surface of the 1 st magnetic sheet 51 slightly moves toward 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 3 rd magnetic sheet 53 is disposed on the other side surface in the thickness direction of the 1 st magnetic sheet 51 so as to cover a portion (an arc surface including the other end edge E4 in the thickness direction) of the circumferential surface of the wiring 2 exposed from the other side surface in the thickness direction of the 1 st magnetic sheet 51 (step 5 is performed).

Thus, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 are arranged in this order toward one side in the thickness direction with respect to the portion overlapping with the wiring 2 when projected in the thickness direction. In addition, the 3 rd magnetic sheet 53, the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 are arranged in this order toward one side in the thickness direction with respect to the portion that does not overlap with the wiring 2 when projected in the thickness direction.

The 6 th step is performed simultaneously with the 4 th step and the 5 th step by the hot pressing.

The hot pressing conditions are selected so that the thermosetting components C of the 1 st adhesive 91, the 2 nd adhesive 92 and the 3 rd adhesive 93 can be staged.

In the 6 th step, the 1 st adhesive 91 of the 1 st magnetic sheet 51, the 2 nd adhesive 92 of the 2 nd magnetic sheet 52, and the 3 rd adhesive 93 of the 3 rd magnetic sheet 53 are simultaneously subjected to the above-described hot pressing to form a C-stage.

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

In addition, the 1 st magnetic piece 51, the 2 nd magnetic piece 52, and the 3 rd magnetic piece 53 are C-staged, so that the boundary between the 1 st magnetic piece 51 and the 2 nd magnetic piece 52 and the boundary between the 1 st magnetic piece 51 and the 3 rd magnetic piece 53 are lost, and 1 magnetic layer 3 including the 1 st magnetic piece 51, the 2 nd magnetic piece 52, and the 3 rd magnetic piece 53 is formed (see fig. 1A). However, in fig. 3F, the boundary is described in order to clearly show the arrangement of the 1 st magnetic piece 51, the 2 nd magnetic piece 52, and the 3 rd magnetic piece 53.

3. Use of

The inductor 1 is a component of an electronic device, that is, a component for manufacturing an electronic device, does not include an electronic component (a chip, a capacitor, or the like) or a mounting board on which an electronic component is mounted, and is a device that is distributed as a single component and is industrially applicable.

The inductor 1 is mounted (assembled) on, for example, an electronic device or the like. The electronic device includes a mounting substrate and an electronic component (chip, capacitor, or the like) mounted on the mounting substrate, but this case is not illustrated. The inductor 1 is mounted on a mounting board via a connecting member such as solder, is electrically connected to other electronic devices, and functions as a passive element such as a coil.

In this method, as shown in fig. 2B, in the 2 nd step, the 1 st magnetic sheet 51 is disposed on one side surface in the thickness direction of the 1 st release sheet 41 so as to cover the major arc of the wiring 2, and therefore, in the portion of the 1 st magnetic sheet 51 that covers the region corresponding to the major arc of the wiring 2, the anisotropic magnetic particles 8 can be oriented in the circumferential direction of the wiring 2. Therefore, the inductor 1 obtained is excellent in inductance.

In addition, in the 2 nd step, since the 1 st magnetic sheet 51 is disposed on one thickness-direction side surface of the 1 st release sheet 41, the 1 st anisotropic magnetic particles 81 are oriented along the one thickness-direction side surface of the 1 st release sheet 41 in the 1 st magnetic sheet 51. Therefore, at both circumferential edges of a region corresponding to the major arc of the wiring 2 facing the one side surface in the thickness direction of the 1 st release sheet 41, that is, in the 2 nd region 12, the 1 st anisotropic magnetic particles 81 can be suppressed from being oriented along the circumferential direction of the wiring 2, and therefore, the inductor 1 is excellent in dc superimposition characteristics.

Further, since the 1 st magnetic sheet 51 covers the major arc of the circumferential surface of the wiring 2, the 1 st anisotropic magnetic particles 81 can be densely arranged with their orientation directions changed from the circumferential direction of the wiring 2 to a direction along one side surface of the 1 st release sheet 41 at both circumferential edges of the major arc. As a result, the inductor 1 having excellent inductance can be manufactured.

In the 4 th step, as shown in fig. 3F, since the 2 nd magnetic sheet 52 covers one side surface in the thickness direction of the 1 st magnetic sheet 51, the arrangement of the anisotropic magnetic particles 8 including the 1 st anisotropic magnetic particles 81 and the 2 nd anisotropic magnetic particles 82 in the peripheral region 4 of the wiring 2 can be made dense. Therefore, the inductor 1 having more excellent inductance can be manufactured.

Therefore, according to this manufacturing method, the arrangement of the anisotropic magnetic particles 8 in the peripheral region 4 can be made dense, and therefore, the inductor 1 having excellent inductance and also excellent dc superimposition characteristics can be manufactured.

In this method, as shown in fig. 3F, since the 3 rd magnetic sheet 53 is also disposed on the other side surface in the thickness direction of the 1 st magnetic sheet 51, the arrangement of the anisotropic magnetic particles 8 including the 1 st anisotropic magnetic particles 81, the 2 nd anisotropic magnetic particles, and the 3 rd anisotropic magnetic particles 83 in the peripheral region 4 of the wiring 2 can be made dense. Therefore, the inductor 1 having more excellent inductance can be manufactured.

In particular, since the 3 rd magnetic sheet 53 covers the portion of the circumferential surface exposed from the other side surface of the 1 st magnetic sheet 51 in the thickness direction, the 3 rd anisotropic magnetic particles 83 can be densely arranged in the region corresponding to the portion of the circumferential surface of the wiring 2 exposed from the 1 st magnetic sheet 51. As a result, the inductor 1 having excellent inductance can be manufactured.

In addition, since the 4 th step and the 5 th step are simultaneously performed in this method, the manufacturing time can be shortened as compared with a method in which the 4 th step and the 5 th step are sequentially performed (see a modification example described later). Therefore, the inductor 1 can be efficiently manufactured.

In the 6 th step of this method, the B-staged thermosetting component of the 1 st adhesive 91 and the B-staged thermosetting component of the 3 rd adhesive 93 are simultaneously C-staged, and therefore, the manufacturing time can be shortened as compared with a method (refer to a modification example described later) in which the B-staged thermosetting component of the 1 st adhesive 91 and the B-staged thermosetting component of the 3 rd adhesive 93 are sequentially performed. Therefore, the inductor can be efficiently manufactured.

< modification of embodiment 1 >

In the modification, the same members and steps as those in embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The modified example can provide the same operational effects as those of embodiment 1, except for the specific description. Further, embodiment 1 and its modified examples can be appropriately combined.

In embodiment 1, the 4 th step, the 5 th step, and the 6 th step are performed simultaneously. However, the 4 th step and the 5 th step may be performed, and the 6 th step may be performed thereafter.

In embodiment 1, the 4 th step and the 5 th step are performed simultaneously. However, the 4 th step and the 5 th step may be performed in this order. Specifically, in this modification, as shown in fig. 4A to 6H, the 1 st step, the 2 nd step, the 4 th step, the 3 rd step, the 5 th step, and the 6 th step are performed in this order.

As shown in fig. 4A, in the 1 st step, the wiring 2 is arranged on one surface in the thickness direction of the 1 st release sheet 41.

As shown in fig. 4B, next, in the 2 nd step, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release pad 46 are sandwiched by the platen press 42, and then, the wiring 2 and the 1 st magnetic sheet 51 are hot-pressed by the platen press 42 through the 1 st release sheet 41, the 2 nd release sheet 45, and the release pad 46. Thus, the 1 st magnetic sheet 51 is disposed on one side surface in the thickness direction of the 1 st release sheet 41 so as to cover the major arc of the peripheral surface of the wiring 2.

As shown in fig. 5D, the 4 th step is performed. Specifically, first, the platen press 42 shown in fig. 4B is released from pressure, and then, as shown in fig. 4C, the 2 nd release sheet 45 and the release pad 46 are taken out from the platen press 42 while the 1 st release sheet 41, the wiring 2, and the 1 st magnetic sheet 51 are kept arranged in the platen press 42.

In the 4 th step, the 2 nd magnetic sheet 52 and the 2 nd release sheet 45 are separately disposed on one side in the thickness direction of the 1 st magnetic sheet 51.

As shown in fig. 5D, next, the 2 nd magnetic sheet 52 is hot-pressed using the platen press 42. Thus, the 2 nd magnetic sheet 52 covers one side surface of the 1 st magnetic sheet 51.

As shown in fig. 6G, the 3 rd step is performed. Specifically, first, the platen press 42 shown in fig. 5D is released from pressure, and the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are taken out of the platen press 42.

In the 3 rd step, next, as shown in fig. 5E, the 1 st release sheet 41 is peeled from the other side surface of the 1 st magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2.

As shown in fig. 5F, the 5 th step is then performed.

Specifically, in the 5 th step, the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are disposed on the platen press 42.

In the 5 th step, as shown in fig. 6G, the 3 rd magnetic sheet 53 is hot-pressed by the platen press 42. Thus, the 3 rd magnetic sheet 53 is disposed on the other side surface of the 1 st magnetic sheet 51 at 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 sinks into the facing portion 28.

The 6 th step is performed after the 5 th step, or the 6 th step is performed simultaneously with the 5 th step. Specifically, the 1 st magnetic piece 51, the 2 nd magnetic piece 52, and the 3 rd magnetic piece 53 are C-staged to form the C-staged magnetic layer 3. Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 covering the wiring 2 is obtained.

As shown in fig. 6H, the inductor 1 is then taken out of the platen press 42.

Of this modification and embodiment 1, embodiment 1 is preferable. In embodiment 1, since the 4 th step and the 5 th step are performed simultaneously, the number of manufacturing steps can be reduced, and the inductor 1 can be manufactured easily.

In the 2 nd step of embodiment 1, as shown in fig. 2B, the 2 nd release sheet 45 is disposed on the platen press 42, but hot pressing may be performed without disposing the 2 nd release sheet 45.

In the 2 nd magnetic sheet 52, the 2 nd anisotropic magnetic particles 82 are oriented in the plane direction, but the 2 nd anisotropic magnetic particles 82 may not be oriented in the plane direction.

< embodiment 2 >

In embodiment 2, the same members and steps as those in embodiment 1 and its modified example are denoted by the same reference numerals, and detailed description thereof is omitted. The embodiment 2 can provide the same operational effects as those of the embodiment 1 and its modified example, except for the specific description. Further, embodiment 1, embodiment 2, and their modifications can be combined 44 as appropriate.

In embodiment 1 shown in fig. 1A to 1B, the intersection 20 is disposed on one side in the thickness direction of the other end edge E4 in the thickness direction of the wiring 2 so as to be spaced apart from the other end edge E4 in the thickness direction of the wiring 2 when projected in the thickness direction, but for example, as shown in fig. 7A to 7B, the intersection 20 may overlap the other end edge E4 in the thickness direction of the wiring 2.

As shown in fig. 7A to 7B, the 4 th region 14 of the inductor 1 according to embodiment 2 is narrower than the 4 th region 14 of the inductor 1 according to embodiment 1. Specifically, the central angle C2 of the 4 th region 14 has an angle α 2 smaller than 15 ° and exceeding 0 °.

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

The method for manufacturing the inductor 1 includes steps 1 to 6. In the method for manufacturing the inductor 1, the 1 st step, the 2 nd step and the 3 rd step are sequentially performed, and then the 4 th step and the 5 th step are simultaneously performed. The 6 th step is performed in stages, and specifically, is performed in hot pressing in the 2 nd step and in hot pressing in the 4 th step and the 5 th step.

(step 1)

As shown in fig. 8A, in the 1 st step, the wiring 2 is arranged on one surface in the thickness direction of the 1 st release sheet 41.

(part of the 2 nd step and the 6 th step)

Next, as shown in fig. 8B, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release pad 46 are sandwiched in order by the platen press 42.

Next, the 1 st magnetic sheet 51 is hot-pressed by the platen press 42. Thus, the 1 st magnetic sheet 51 is disposed on one side surface in the thickness direction of the 1 st release sheet 41 so as to cover the major arc of the peripheral surface of the wiring 2.

After the 2 nd step or simultaneously with the 2 nd step, the 1 st magnetic sheet 51 is heated by the heat source of the platen press 42 to be staged as the 1 st magnetic sheet 51C (a part of the 6 th step is performed).

(step 3)

In the 3 rd step, first, the platen press 42 shown in fig. 8B is released from pressure, and then, as shown in fig. 8C, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release liner 46 are taken out from the platen press 42.

Next, the 1 st release sheet 41 is peeled from the other side surface of the 1 st magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2.

Further, the 2 nd release sheet 45 and the release liner 46 are peeled off from one side surface of the 1 st magnetic sheet 51.

(the remaining part of the 4 th step, the 5 th step, and the 6 th step)

As shown in fig. 9E, the 4 th step and the 5 th step are performed simultaneously.

As shown in fig. 9D, in the 4 th step and the 5 th step, first, the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are arranged in the platen press 42. In addition, the 1 st magnetic sheet 51 and the 3 rd magnetic sheet 53 are both B-staged.

As shown in fig. 9E, next, the 1 st magnetic sheet 51 and the 3 rd magnetic sheet 53 are pressed by the platen press 42.

Thereby, the 2 nd magnetic sheet 52 covers one side surface in the thickness direction of the 1 st magnetic sheet 51.

The 3 rd magnetic sheet 53 is disposed on the other side surface in the thickness direction of the 1 st magnetic sheet 51 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 side surface of the 1 st magnetic sheet 51, which is relatively hard at the C stage, is suppressed, and the sinking of the other end edge E4 in the thickness direction of the wiring 2 into the facing portion 28 of the 3 rd magnetic sheet 53 is suppressed. That is, one side surface of the 3 rd magnetic sheet 53 can be maintained flat.

Thereafter, the 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53 are heated by the heat source of the platen press 42, and the 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53C are staged (the rest of the 6 th step is performed).

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 of the platen press 42.

Among the embodiments 1 and 2, the embodiment 1 is preferable. In embodiment 1, since the B-stage thermosetting component of the 1 st adhesive 91 and the B-stage thermosetting component of the 3 rd adhesive 93 are simultaneously converted to the C-stage in the 6 th step, the manufacturing time can be shortened as compared with embodiment 2 in which the B-stage thermosetting component of the 1 st adhesive 91 and the B-stage thermosetting component of the 3 rd adhesive 93 are sequentially performed. Therefore, the inductor 1 can be easily manufactured.

< modification of embodiment 2 >

In the modification, the same members and steps as those in embodiment 2 are denoted by the same reference numerals, and detailed description thereof is omitted. The modified example can provide the same operational effects as those of embodiment 2, except for the specific description. Further, embodiment 2 and its modified examples can be appropriately combined.

In embodiment 2, the 4 th step, the 5 th step, and the remaining part of the 6 th step are performed simultaneously. However, the 4 th step and the 5 th step may be performed, and the remaining part of the 6 th step may be performed thereafter.

In embodiment 2, the 4 th step and the 5 th step are performed simultaneously. However, the 4 th step and the 5 th step may be performed in this order.

In this modification, as shown in fig. 10A to 12H, the 1 st step, the 2 nd step, the 4 th step, the 3 rd step, and the 5 th step are performed in this order. The 6 th step is performed in stages.

As shown in fig. 10A, in the 1 st step, the wiring 2 is arranged on one surface in the thickness direction of the 1 st release sheet 41.

As shown in fig. 10B, the 2 nd step is performed, and the 1 st magnetic sheet 51C is stepped. That is, a part of the step 6 is performed. Specifically, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release gasket 46 are sandwiched in this order by the platen press 42, and then the wiring 2 and the 1 st magnetic sheet 51 are hot-pressed by the platen press 42 through the 1 st release sheet 41, the 2 nd release sheet 45, and the release gasket 46. The 1 st magnetic sheet 51C is stepped by the heat source of the platen press 42 (a part of the 6 th step is performed).

As shown in fig. 11D, the 4 th step is performed. Specifically, first, the platen press 42 shown in fig. 10B is released from pressure, and then, as shown in fig. 10C, the 2 nd release sheet 45 and the release pad 46 are taken out from the platen press 42 while the 1 st release sheet 41, the wiring 2, and the 1 st magnetic sheet 51 are kept arranged in the platen press 42.

In the 4 th step, the 2 nd magnetic sheet 52 and the 2 nd release sheet 45 are separately disposed on one side in the thickness direction of the 1 st magnetic sheet 51.

As shown in fig. 11D, next, the 2 nd magnetic sheet 52 is hot-pressed using the platen press 42. Thus, the 2 nd magnetic sheet 52 covers one side surface of the 1 st magnetic sheet 51.

As shown in fig. 11F, the 3 rd step is then performed.

In step 3, specifically, first, the pressing of the platen press 42 shown in fig. 11D is released, and the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are taken out of the platen press 42.

In the 3 rd step, next, as shown in fig. 11E, the 1 st release sheet 41 is peeled from the other side surface of the 1 st magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2.

As shown in fig. 12G, the 5 th step is then performed.

As shown in fig. 11F, in the 5 th step, first, specifically, the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are disposed on the platen press 42.

In the 5 th step, as shown in fig. 12G, the 3 rd magnetic sheet 53 is hot-pressed by the platen press 42. Thus, the 3 rd magnetic sheet 53 is disposed on the other side surface of the 1 st magnetic sheet 51 at the C stage so as to cover the other end edge E4 in the thickness direction of the wiring 2.

After the 5 th step, the rest of the 6 th step is performed, or the rest of the 6 th step is performed simultaneously with the 5 th step. Specifically, the 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53C are staged by the heat source of the platen press 42, and the magnetic layer 3 composed of the 3 rd magnetic sheet 53, the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 is formed. Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 covering the wiring 2 is obtained.

As shown in fig. 12H, thereafter, the inductor 1 is taken out of the platen press 42.

In the above-described modification, the 1 st magnetic piece 51C is stepped while the 2 nd step of arranging the 1 st magnetic piece 51 with respect to the wiring 2 shown in fig. 10B is performed, but the timing of stepping the 1 st magnetic piece 51C is not particularly limited as long as it is before the 5 th step (see fig. 5G) of arranging the 3 rd magnetic piece 53 on the other side surface of the 1 st magnetic piece 51, and for example, it may be performed while the 4 th step of arranging the 2 nd magnetic piece 52 shown in fig. 11D is performed.

In addition, the 1 st magnetic piece 51 and the 2 nd magnetic piece 52 can be simultaneously C-staged. The 2 nd magnetic sheet 52 is disposed on one side of the 1 st magnetic sheet 51 in the B stage, and then the 1 st magnetic sheet 51 and the 2 nd magnetic sheet 52 are simultaneously subjected to the C stage.

Further, the 2 nd magnetic piece 52C may be stepped, the 3 rd magnetic piece 53 may be disposed on the other side surface of the 1 st magnetic piece 51, and the 3 rd magnetic piece 53C may be stepped.

Further, the 3 rd magnetic sheet 53 may be disposed on the other side surface of the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 may be disposed on one side surface of the 1 st magnetic sheet 51. In this case, the 3 rd magnetic piece 53 and the 2 nd magnetic piece 52 can be simultaneously C-staged, and the 3 rd magnetic piece 53 can be C-staged and then the 2 nd magnetic piece 52 can be C-staged.

As shown in fig. 13A, in the 1 st step, the wiring 2 may be disposed not on the 1 st release sheet 41 but on one side surface in the thickness direction of the 3 rd magnetic sheet 53 (an example of a substrate) in the C stage.

Specifically, first, the 3 rd magnetic sheet 53 at the C stage is produced and arranged on one surface in the thickness direction of the 1 st release sheet 41. The 3 rd binder 93 in the 3 rd magnetic sheet 53 contains a cured product of a B-stage thermosetting component.

Next, the 1 st release sheet 41, the 3 rd magnetic sheet 53 at the C stage, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release pad 46 are sandwiched by the platen press 42.

As shown in fig. 13B, the 2 nd step is performed. In the 2 nd step, the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release liner 46 are sandwiched in this order by the platen press 42.

Next, the 3 rd magnetic sheet 53, the wiring 2, and the 1 st magnetic sheet 51 are hot-pressed by the platen press 42 through the 1 st release sheet 41, the 2 nd release sheet 45, and the release pad 46. Thus, the 1 st magnetic piece 51 is arranged on one side surface in the thickness direction of the 3 rd magnetic piece 53 at the C stage so as to cover the major arc of the circumferential surface of the wiring 2.

Next, in the 4 th step, first, the pressing of the platen press 42 shown in fig. 13B is released, and then, as shown in fig. 13C, the 2 nd release sheet 45 and the release pad 46 are taken out from the platen press 42 while maintaining the arrangement of the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, and the 1 st magnetic sheet 51 in the platen press 42.

Next, in the 4 th step, the 2 nd magnetic sheet 52 and the 2 nd release sheet 45 are separately disposed on one side in the thickness direction of the 1 st magnetic sheet 51. The 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45 are sandwiched by the platen press 42.

As shown in fig. 14D, thereafter, the 2 nd magnetic sheet 52 is pressed by the platen press 42.

Thereafter, the 2 nd magnetic piece 52 and the 1 st magnetic piece 51C are staged. Thereby, the magnetic layer 3 including the 3 rd magnetic sheet 53, the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 is formed.

As shown in fig. 14E, after that, the inductor 1 is obtained.

In the above modification, the 1 st magnetic piece 51 and the 2 nd magnetic piece 52 are simultaneously C-staged, but for example, the 1 st magnetic piece 51 may be C-staged and then the 2 nd magnetic piece 52 may be C-staged.

< other modification example >

In this other modification, the same members and steps as those in embodiment 1 and embodiment 2 are denoted by the same reference numerals, and detailed description thereof is omitted. The modified example can provide the same operational effects as those of embodiment 1 and embodiment 2, except for the specific description. Further, embodiment 1 and embodiment 2 and their modifications can be combined as appropriate.

As shown in fig. 15A, in the 1 st step, the wiring 2 can be disposed on one side surface of the 1 st release sheet 41 via the pressure-sensitive adhesive layer 61.

The pressure-sensitive adhesive layer 61 extends in the 2 nd direction and is in a thin-walled thin sheet shape. The ratio of the length of the pressure-sensitive adhesive layer 61 in the 1 st 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 2 nd step, the 1 st magnetic sheet 51 covers the major arc of the peripheral surface of the wiring 2 so as to be filled on both sides of the pressure-sensitive adhesive layer 61 in the 1 st direction.

As shown in fig. 15C, in the inductor 1, the pressure-sensitive adhesive layer 61 may remain between the 3 rd magnetic sheet 53 and the other end edge E4 in the thickness direction, or the pressure-sensitive adhesive layer 61 may be removed after the 2 nd step, which is not shown.

As shown in fig. 16A, in the 1 st step, the wiring 2 can be disposed on the 1 st release sheet 41 side with the gap 62 therebetween. For example, spacers (not shown) are interposed between both ends of the wiring 2 in the 2 nd direction and the 1 st release sheet 41, thereby tightening the wiring 2 in both sides in the 2 nd direction and securing the gap 62 that separates the other end edge E4 in the thickness direction of the wiring 2 from one side surface of the wiring 2.

As shown in fig. 16B, the 1 st magnetic sheet 51 is filled in the gap 62 under the heat press in the 2 nd step, so that the 1 st magnetic sheet 51 covers the entire circumferential surface of the wiring 2.

Thereafter, as shown in fig. 16C, one side surface of the 1 st magnetic sheet 51 is covered with the 2 nd magnetic sheet 52.

Thereafter, for example, heat and pressure are applied simultaneously to step the 1 st adhesive 91 of the 1 st magnetic sheet 51 and the 2 nd adhesive 92C of the 2 nd magnetic sheet 52.

Thereby, the magnetic layer 3 composed of the 1 st magnetic sheet 51 and the 2 nd magnetic sheet 52 is formed.

In this method, the other end edge E4 in the thickness direction of the wiring 2 can be covered with the magnetic layer 3 without disposing the 3 rd magnetic sheet 53. Therefore, the number of man-hours can be reduced.

As shown by the imaginary line in fig. 16C, the 3 rd magnetic piece 53 may be further disposed on the other side surface of the 2 nd magnetic piece 52 as needed.

As shown in fig. 2A, in the 1 st step, the wiring 2 may be brought into contact with one side surface of the 1 st release sheet 41, and then, as shown by the imaginary line arrow in fig. 6B, the pressing conditions in the 2 nd step may be adjusted so that the 1 st magnetic composition constituting the 1 st magnetic sheet 51 enters the other side in the thickness direction of the wiring 2 so as to cover the other end edge E4 in the thickness direction of the wiring 2. In this modification, the spacer is not required, and therefore, the inductor 1 can be easily manufactured.

The 1 st anisotropic magnetic particles 81, but it is also possible, for example, for the 1 st magnetic particles to have no anisotropy, but, for example, to have isotropy. The shape of the 1 st isotropic magnetic particle is, for example, a substantially spherical shape. Examples of the 1 st isotropic magnetic particle having a substantially spherical shape include iron particles having a substantially spherical shape. The 1 st isotropic magnetic particle has an average particle diameter of, for example, 0.1 μm or more, preferably 0.5 μm or more, and further, for example, 200 μm or less, preferably 150 μm or less.

As shown in fig. 2A of embodiment 1, fig. 4A of a modification of embodiment 1, fig. 8A of embodiment 2, and fig. 10A and fig. 13A of a modification of embodiment 2, the 1 st anisotropic magnetic particles 81 are oriented in the plane direction in the 1 st magnetic sheet 51, but the present invention is not limited thereto, and the 1 st anisotropic magnetic particles 81 may not be oriented in the plane direction in the 1 st magnetic sheet 51.

In embodiment 1 and embodiment 2, the 3 rd anisotropic magnetic particles 83 are given as an example of the 3 rd magnetic particles, but for example, the 3 rd magnetic particles may have isotropy, instead of anisotropy. The shape of the 3 rd isotropic magnetic particle is, for example, a substantially spherical shape. Examples of the 3 rd isotropic magnetic particle having a substantially spherical shape include iron particles having a substantially spherical shape. The 3 rd isotropic magnetic particle has an average particle diameter of, for example, 0.1 μm or more, preferably 0.5 μm or more, and further, for example, 200 μm or less, preferably 150 μm or less.

As shown in fig. 3D of embodiment 1, fig. 5F of a modification of embodiment 1, fig. 9D of embodiment 2, and fig. 11F and 13C of a modification of embodiment 2, the 3 rd anisotropic magnetic particles 83 are oriented in the plane direction in the 3 rd magnetic sheet 53, but the present invention is not limited thereto, and the 3 rd anisotropic magnetic particles 83 may not be oriented in the plane direction in the 3 rd magnetic sheet 53.

As shown in fig. 1B and 7B, in embodiment 1 and embodiment 2, the anisotropic magnetic particles 8 are oriented in the circumferential direction of the wiring 2 at least in the 1 st region 11, but the present invention is not limited thereto, and the anisotropic magnetic particles 8 may not be oriented in the circumferential direction of the wiring 2.

The ratio (filling ratio) of the magnetic particles (1 st magnetic particle, 2 nd anisotropic magnetic particle 82, and 3 rd magnetic particle) in the magnetic layer 3 is not limited to the above description, and for example, the ratio (filling ratio) may be higher or lower as the distance from the wiring 2 increases. In manufacturing the inductor 1 in which the proportion of the magnetic particles of the magnetic layer 3 becomes higher as it goes away from the wiring 2, for example, the proportion of the presence of the 2 nd anisotropic magnetic particles 82 in the 2 nd magnetic sheet 52 is set higher than the proportion of the presence of the magnetic particles in the 1 st magnetic sheet 51.

In a modification in which the filling rate of the magnetic particles in the magnetic layer 3 is increased or decreased as the distance from the wiring 2 increases as described above, the magnetic layer 3 may be a plurality of layers. In this case, the wiring 2 may be pressed by 1 of the plurality of magnetic sheets for covering the outer peripheral surface of the wiring 2, and then the remaining magnetic sheets may be pressed against them, or the plurality of magnetic sheets may be pressed against the wiring 2 at once (together). For example, the wiring 2 can be pressed at a time by the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 3 rd magnetic sheet 53 of one embodiment. Specifically, the 1 st step shown in fig. 13A, the 2 nd step shown in fig. 13B, and the 4 th step shown in fig. 13C can be performed simultaneously.

Examples

The present invention will be described in more detail below with reference to examples and comparative examples. In addition, the present invention is not limited to any examples and comparative examples. In addition, specific numerical values such as a compounding ratio (content ratio), a physical property value, and a parameter used in the following description may be substituted for upper limit values (numerical values defined as "lower" and "smaller") or lower limit values (numerical values defined as "upper" and "larger") described in association with the compounding ratio (content ratio), the physical property value, the parameter, and the like described in the above-described "embodiment".

Example 1

< example of manufacturing inductor based on embodiment 1 >

In example 1, an inductor 1 was manufactured based on embodiment 1. Specifically, as shown in fig. 2A to 3F, the 1 st step, the 2 nd step, and the 3 rd step are performed in this order, and then the 4 th step, the 5 th step, and the 6 th step are performed simultaneously.

(step 1)

The wiring 2 and the 1 st release sheet 41 were prepared.

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

Separately, a1 st release sheet 41 made of PET having a thickness of 50 μm was prepared.

As shown in fig. 2A, the wiring 2 is then arranged on one side surface in the thickness direction of the 1 st release sheet 41.

(step 2)

The 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release liner 46 were prepared.

Specifically, the 1 st magnetic sheet 51 as a B-stage sheet was prepared, which was composed of a laminated sheet of an inner sheet 54 having a ratio of anisotropic magnetic particles 8 of 50 vol% and an outer sheet 55 having a ratio of anisotropic magnetic particles 8 of 60 vol%. The formulations of the inner sheet 54 and the outer sheet 55 are shown in table 1.

As the 2 nd release sheet 45, a release film (manufactured by mitsui chemical xylonite) made of TPX (registered trademark) was prepared.

Further, a release liner 46 in which two release films OT-a110 (manufactured by waterlogging chemical industries) were laminated was prepared.

The thickness of the release liner 46 (total thickness of the release film OT-A110) was 110. mu.m, and included A1 st layer 47 having a thickness of 15 μm, a2 nd layer 48 having a thickness T2 of 80 μm, and a 3 rd layer 49 having a thickness of 15 μm. The tensile storage elastic modulus E' at 110 ℃ of the 1 st layer 47 and the 3 rd layer 49 was 190MPa, and the material of the 1 st layer 47 and the 3 rd layer 49 contained polybutylene terephthalate as a main component. The tensile storage elastic modulus E' at 110 ℃ of the 2 nd layer 48 was 5.6MPa, and the material of the 2 nd layer 48 contained an ethylene-methyl methacrylate copolymer as a main component.

Next, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release pad 46 are sandwiched in this order by the platen press 42.

As shown in fig. 2B, the wiring 2 and the 1 st magnetic sheet 51 were then hot-pressed by the platen press 42 under a pressing pressure of 2MPa, 110 ℃ and 60 seconds.

Fig. 17A shows an SEM photograph of the cross section of the wiring 2 and the 1 st magnetic sheet 51 after the 2 nd step.

(step 3)

In the 3 rd step, first, the platen press 42 shown in fig. 2B is released from pressure, and then, as shown in fig. 2C, the 1 st release sheet 41, the wiring 2, the 1 st magnetic sheet 51, the 2 nd release sheet 45, and the release liner 46 are taken out of the platen press 42. Next, the 1 st release sheet 41 is peeled from the other side surface of the 1 st magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2. Further, the 2 nd release sheet 45 and the release liner 46 were peeled from one side surface of the 1 st magnetic sheet 51.

(step 4, step 5 and step 6)

The 2 nd magnetic sheet 52 and the 3 rd magnetic sheet 53 are prepared.

Specifically, 5 sheets of the same formulation (the ratio of the anisotropic magnetic particles 8 is 60 vol%) as the outer sheet 55 of the 1 st magnetic sheet 51 were prepared, and the 2 nd magnetic sheet 52 as a B-stage sheet was prepared as a laminated sheet of these sheets.

In addition, 4 sheets of the same formulation as the outer sheet 55 of the 1 st magnetic sheet 51 (the proportion of the anisotropic magnetic particles 8 is 60 vol%) and 1 sheet of the same formulation as the inner sheet 54 of the 1 st magnetic sheet 51 (the proportion of the anisotropic magnetic particles 8 is 50 vol%) were stacked and prepared, and the 3 rd magnetic sheet 53 as a B-stage sheet was prepared from the stacked sheets.

Next, as shown in fig. 3D, between the 1 st plate 43 and the 2 nd plate 44, the 1 st release sheet 41, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 2 nd release sheet 45(PET film) are arranged in this order toward one side in the thickness direction.

As shown in fig. 3E, the 3 rd magnetic sheet 53, the wiring 2, the 1 st magnetic sheet 51, and the 2 nd magnetic sheet 52 were then hot-pressed by the platen press 42 under a pressing pressure of 2MPa, 170 ℃, and 900 seconds. Thereby, the thermosetting component C in the 1 st adhesive 91, the 2 nd adhesive 92, and the 3 rd adhesive 93 is staged.

Thus, the magnetic layer 3 including the 1 st magnetic sheet 51, the 2 nd magnetic sheet 52, and the 3 rd magnetic sheet 53 at the C stage covers the circumferential surface of the wiring 2, and the inductor 1 shown in fig. 1A to 1B is manufactured.

As shown in fig. 3F, the inductor 1 is then removed from the flat bed press 42.

Fig. 17B shows an SEM photograph of a cross section of the inductor 1.

Example 2

< example of manufacturing inductor based on modification of embodiment 1 >

In example 2, an inductor 1 was manufactured based on the modification of embodiment 1 shown in fig. 4A to 6H. Specifically, the treatment was performed in the same manner as in example 1 except that the 1 st step, the 2 nd step, the 4 th step, the 3 rd step, the 5 th step, and the 6 th step were sequentially performed.

As shown in fig. 7A to 7B, the inductor 1 is shown in fig. 18 by SEM photographs of a cross section of the inductor 1.

Examples 3 to 5

Inductor 1 was produced by the same process as in example 1, except that the formulation of first magnetic sheet 51 was changed from table 1.

Comparative example 1

A1 st release sheet 41 made of PET, a 3 rd magnetic sheet 53 at the C stage, A1 st adhesive layer at the B stage, wiring 2, a2 nd adhesive layer at the B stage, a2 nd magnetic sheet 52 at the C stage, a2 nd release sheet 45 made of TPX, and a release liner 46 obtained by laminating two release films OT-a110 (manufactured by hydropneumatic chemical industries) are disposed in this order on one side of the 1 st plate 43 in the thickness direction, and a laminate composed of these sheets is sandwiched by the 1 st plate 43 and the 2 nd plate 44.

The 1 st adhesive layer and the 2 nd adhesive layer do not contain the anisotropic magnetic particles 8 and are B-stage sheets made of a thermosetting resin. The thickness of the 1 st adhesive layer and the 2 nd adhesive layer was 2 μm, respectively.

The formulations of the C-stage 2 nd magnetic sheet 52 and the C-stage 3 rd magnetic sheet 53 were completely cured as shown in table 1.

Next, the laminate was hot-pressed by the platen press 42 under a pressing pressure of 2MPa, 170 ℃, and 900 seconds using the platen press 42, thereby manufacturing the inductor 1.

Fig. 19 shows an SEM photograph of a cross section of the inductor 1 of comparative example 1.

As is clear from fig. 19, voids are formed between the 2 nd arc surface 24 of the wiring 2 and the 1 st magnetic sheet 51 (magnetic layer 3), and between the 1 st direction both end edges E2, E3 of the wiring 2 and the 1 st magnetic sheet 51 (magnetic layer 3).

Comparative example 2

A1 st release sheet 41 made of PET having a thickness of 50 μm, a 3 rd magnetic sheet 53 at the C stage, A1 st pressure-sensitive adhesive layer, the wiring 2, a2 nd pressure-sensitive adhesive layer, a2 nd magnetic sheet 52 at the C stage, a2 nd release sheet 45 made of TPX, and a release liner 46 obtained by laminating two release films OT-a110 (manufactured by hydropneumatic chemical industries) are disposed in this order on one side of the 1 st plate 43 in the thickness direction, and a laminate composed of these is sandwiched by the 1 st plate 43 and the 2 nd plate 44.

Further, neither the 1 st pressure-sensitive adhesive layer nor the 2 nd pressure-sensitive adhesive layer contains the anisotropic magnetic particles 8, but is a pressure-sensitive adhesive tape (adhesive tape) composed of an acrylic pressure-sensitive adhesive (adhesive). The thickness of the 1 st pressure-sensitive adhesive layer and the 2 nd pressure-sensitive adhesive layer was 5 μm, respectively.

The formulations of the 2 nd magnetic sheet 52 at the C stage and the 3 rd magnetic sheet 53 at the C stage were completely cured as shown in table 1.

Next, the laminate was hot-pressed by the platen press 42 under a pressing pressure of 2MPa, 110 ℃ and 60 seconds by using the platen press 42, thereby manufacturing the inductor 1.

Voids are formed between the 2 nd arc surface 24 of the wiring 2 and the 1 st magnetic sheet 51 (magnetic layer 3), and between the 1 st direction both end edges E2, E3 of the wiring 2 and the 1 st magnetic sheet 51 (magnetic layer 3).

< filling Rate >

The filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 of the inductor 1 was calculated from binarization of the cross-sectional view of the SEM photograph. Specifically, in the SEM photograph, white is recognized as the anisotropic magnetic particles 8, and black is recognized as the binder 9, and then, the filling ratio (existence ratio) of the anisotropic magnetic particles 8 is obtained from the ratio of the cross-sectional area of white in the 1 st region 11.

The results are shown in table 1.

< inductance >

Both ends of the lead wire 6 in the conveying direction were exposed from the insulating layer 7 and the magnetic layer 3 to form two exposed portions, and the two exposed portions were connected to an impedance analyzer (manufactured by Agilent corporation: 4294A) to obtain the inductance, and the inductance of the inductor 1 was evaluated in accordance with the following criteria.

Very good: the inductance is more than 110H

O: the inductance is more than 90H and less than 110H

And (delta): the inductance is more than 60H and less than 90H

X: inductance less than 60H

The results are shown in table 1.

[ TABLE 1]

The present invention is provided as an exemplary embodiment thereof, but this is merely an example and the present invention is not to be construed as being limited thereto. Modifications of the present invention that are obvious to those skilled in the art are intended to be included within the scope of the appended claims.

Industrial applicability

The inductor is mounted on, for example, an electronic device.

Description of the reference numerals

1. An inductor; 2. wiring; 3. a magnetic layer; 4. a peripheral region; 6. a wire; 7. an insulating layer; 8. anisotropic magnetic particles; 9. a binder; 41. a1 st release sheet; 51. a1 st magnetic sheet; 52. the 2 nd magnetic sheet 52; 53. a 3 rd magnetic sheet; 81. 1 st anisotropic magnetic particle (one example of 1 st magnetic particle); 82. 2 nd anisotropic magnetic particles (an example of the 2 nd magnetic particles); 83. 3 rd anisotropic magnetic particles (one example of the 3 rd magnetic particles); 91. 1, a binder; 92. a2 nd binder; 93. and 3. a binder.