Method of manufacturing an inductor

Abstract

A method for manufacturing an inductor (1) includes: a first step in which a wiring (2) having a substantially circular shape in a cross section and including a conductor wire (6) and an insulating layer (7) covering the conductor wire (6) is disposed on a thickness direction one side surface of a substrate; a second step in which a first magnetic sheet (51) containing first magnetic particles and a first binder (91) dispersing the first magnetic particles is disposed on a thickness direction one side surface of a first release sheet (41) so as to cover a major arc of a circumferential surface of the wiring (2); and a fourth step in which a second magnetic sheet (52) containing second magnetic particles and a second binder (92) dispersing the second magnetic particles covers the thickness direction one side surface of the first magnetic sheet (51) on the major arc of the circumferential surface of the wiring (2) and the one side surface of the first release sheet (41).

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of an inductor. BACKGROUND

[0002] Conventionally, an inductor is known to be mounted on an electronic device or the like and used as a passive element of a voltage conversion member or the like.

[0003] For example, an inductor is proposed which includes a rectangular parallelepiped-shaped substrate main body portion formed of a magnetic material, and an internal conductor of copper or the like embedded in the inside of the substrate main body portion (see Patent Document 1).

[0004] In Patent Document 1, the inductor is manufactured by printing to stack a plurality of layers of a conductor layer formed of a conductor paste.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 10-144526 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] However, in recent years, higher inductance is required for the inductor.

[0010] The present application provides a manufacturing method of an inductor capable of manufacturing an inductor with excellent inductance.

[0011] SOLUTION TO PROBLEM

[0012] The present application (1) provides a manufacturing method of an inductor, wherein the manufacturing method of the inductor includes: a first step in which a wiring is disposed on a thickness direction one side surface of a substrate, the wiring having a shape in a cross section that is substantially circular and including a conductor wire and an insulating layer covering the conductor wire; a second step in which a first magnetic sheet is disposed on the thickness direction one side surface of the substrate in a manner to cover an area of the circumference surface of the wiring that exceeds 180° in a cross section, the first magnetic sheet containing first magnetic particles and a first binder that disperses the first magnetic particles; and a fourth step in which a thickness direction one side surface of the first magnetic sheet that covers the area of the circumference surface of the wiring and the one side surface of the substrate is covered with a second magnetic sheet, the second magnetic sheet containing second magnetic particles and a second binder that disperses the second magnetic particles, the second magnetic particles including second anisotropic magnetic particles oriented in a surface direction.

[0013] In this method, in the second step, the first magnetic sheet is arranged on the one side surface of the substrate in the thickness direction in a manner to cover an area exceeding 180° in the circumferential surface of the wiring when the area is sectioned, so the first magnetic particles can be densely arranged. As a result, an inductor with excellent inductance can be manufactured.

[0014] Also, in the fourth step, the second magnetic sheet covers the one side surface of the first magnetic sheet in the thickness direction, so the first magnetic particles and the second magnetic particles in the peripheral area of the wiring can be densely arranged. Therefore, an inductor with even more excellent inductance can be manufactured.

[0015] Thus, with this manufacturing method, the first magnetic particles and the second magnetic particles in the peripheral area can be densely arranged, and an inductor with excellent inductance can be manufactured.

[0016] The present application (2) is the manufacturing method of an inductor according to (1), wherein the first magnetic particles contain first anisotropic magnetic particles oriented in the surface direction in the first magnetic sheet.

[0017] With this method, in the second step, the first magnetic sheet is arranged on the one side surface of the substrate in the thickness direction, and in the first magnetic sheet, the first anisotropic magnetic particles are oriented along the one side surface of the substrate in the thickness direction. Therefore, at the both end edges in the circumferential direction of the area of the wiring facing the one side surface in the thickness direction, the orientation of the first anisotropic magnetic particles in the circumferential direction of the wiring can be suppressed, so the DC superposition characteristics of the inductor are excellent.

[0018] Also, the first magnetic sheet covers an area exceeding 180° in the circumferential surface of the wiring, so at the both end edges in the circumferential direction of the area, the orientation direction of the first anisotropic magnetic particles can be changed from the circumferential direction of the wiring to the direction along the one side surface of the substrate, and the first anisotropic magnetic particles can be densely arranged. As a result, an inductor with even more excellent inductance can be manufactured.

[0019] Thus, with this method, an inductor with excellent inductance and DC superposition characteristics can be manufactured.

[0020] The present application (3) is the manufacturing method of an inductor according to (1) or (2), wherein the substrate is a release sheet, the manufacturing method of an inductor further includes: a third step in which the substrate is removed; and a fifth step in which a third magnetic sheet containing third magnetic particles and a third binder that disperses the third magnetic particles is arranged on the other side surface of the first magnetic sheet in the thickness direction in a manner to cover the part of the circumferential surface exposed from the other side surface of the first magnetic sheet in the thickness direction.

[0021] In this method, the third magnetic sheet is also disposed on the other side of the first magnetic sheet in the thickness direction, and thus the first magnetic particles, the second anisotropic magnetic particles, and the third magnetic particles in the peripheral region of the wiring can be densely disposed. Therefore, an inductor having a more excellent inductance can be manufactured.

[0022] In particular, the third magnetic sheet covers the portion of the circumferential surface exposed from the other side of the first magnetic sheet in the thickness direction, and thus the third magnetic particles can be densely disposed in the region corresponding to the portion of the circumferential surface of the wiring exposed from the first magnetic sheet. As a result, an inductor having an excellent inductance can be manufactured.

[0023] The present application (4) is the method for manufacturing an inductor according to (3), wherein the third magnetic particles include third anisotropic magnetic particles oriented in the surface direction in the third magnetic sheet.

[0024] With this method, in the fifth process, the third anisotropic magnetic particles can be oriented and densely disposed in the region corresponding to the portion of the circumferential surface of the wiring exposed from the first magnetic sheet. As a result, an inductor having a more excellent inductance can be manufactured.

[0025] The present application (5) is the method for manufacturing an inductor according to (3) or (4), wherein the first process, the second process, and the third process are sequentially performed, and then the fourth process and the fifth process are simultaneously performed.

[0026] In this method, the fourth process and the fifth process are simultaneously performed, and thus the manufacturing time can be shortened compared to the method in which the fourth process and the fifth process are sequentially performed. Therefore, an inductor can be efficiently manufactured.

[0027] The present application (6) is the method for manufacturing an inductor according to any one of (3) to (5), wherein the first binder in the second process and the third binder in the fifth process each contain a B-stage thermosetting component, and the method for manufacturing an inductor further includes a sixth process in which the B-stage thermosetting component of the first binder and the B-stage thermosetting component of the third binder are simultaneously C-staged.

[0028] In the sixth process of this method, the B-stage thermosetting component of the first binder and the B-stage thermosetting component of the third binder are simultaneously C-staged, and thus the manufacturing time can be shortened compared to the method in which the B-stage thermosetting component of the first binder and the B-stage thermosetting component of the third binder are sequentially performed. Therefore, an inductor can be efficiently manufactured.

[0029] The present application (7) is the method for manufacturing an inductor according to (1) or (2), wherein the substrate is a third magnetic sheet containing third magnetic particles and a third binder that disperses the third magnetic particles, and the third binder contains a cured product of a thermosetting component.

[0030] In this method, the substrate is the third magnetic sheet, so it is not necessary to perform a process of removing the substrate such as a release film. Therefore, it is possible to reduce working hours and to easily manufacture an inductor.

[0031] The present application (8) is the method for manufacturing an inductor according to (7), wherein the third magnetic particles include third anisotropic magnetic particles that are oriented in a surface direction in the third magnetic sheet.

[0032] In this method, the third magnetic particles include the third anisotropic magnetic particles that are oriented in the surface direction in the third magnetic sheet, so the third anisotropic magnetic particles can be oriented along a portion of the wiring that faces the third magnetic sheet. Therefore, it is possible to manufacture an inductor with more excellent inductance.

[0033] Effects of the Invention

[0034] The method for manufacturing an inductor of the present application makes it possible to manufacture an inductor with excellent inductance. BRIEF DESCRIPTION OF DRAWINGS

[0035] [ Figure 1 ] Figure 1 A ~ Figure 1 B is a cross-sectional view of an inductor obtained by the first embodiment of the present application, Figure 1 A is a cross-sectional view in which the section is hatched, Figure 1 B is a cross-sectional view that shows the orientation of anisotropic magnetic particles in a magnetic layer.

[0036] [ Figure 2 ] Figure 2 A ~ Figure 2 C is a process chart that explains the method for manufacturing an inductor of the first embodiment, Figure 2 A indicates a first process of disposing a wiring on a first release sheet, Figure 2 B indicates a second process of covering the wiring with a first magnetic sheet, Figure 2 C indicates a third process of removing the first release sheet.

[0037] [ Figure 3 ] Figure 3 D ~ Figure 3 F is a continuation of Figure 2 C is a continuation of the process chart that explains the method for manufacturing an inductor of the first embodiment, Figure 3 D indicates a process of disposing a second magnetic sheet and a third magnetic sheet, Figure 3E indicates a fourth process of covering one side surface of the first magnetic sheet with the second magnetic sheet and a fifth process of covering the other side surface of the first magnetic sheet at the B stage with the third magnetic sheet, Figure 3 F indicates a process of taking out the inductor.

[0038] [ Figure 4 ] Figure 4 A ~ Figure 4 C is a process chart of a manufacturing method of a modification example of the first embodiment, Figure 4 A indicates a first process of disposing a wiring on a first release sheet, Figure 4 B indicates a second process of covering the wiring with the first magnetic sheet, Figure 4 C indicates a process of disposing the second magnetic sheet.

[0039] [ Figure 5 ] Figure 5 D ~ Figure 5 F is next Figure 4 C continues the process chart of the manufacturing method of the modification example of the first embodiment, Figure 5 D indicates a fourth process of covering one side surface of the first magnetic sheet with the second magnetic sheet, Figure 5 E indicates a third process of removing the first release sheet, Figure 5 F indicates a process of disposing the third magnetic sheet.

[0040] [ Figure 6 ] Figure 6 G ~ Figure 6 H is next Figure 5 F continues the process chart of the manufacturing method of the modification example of the first embodiment, Figure 6 G indicates a fifth process of covering the other side surface of the first magnetic sheet at the B stage with the third magnetic sheet, Figure 6 H indicates a process of taking out the inductor.

[0041] [ Figure 7 ] Figure 7 A ~ Figure 7 B is a sectional view of an inductor obtained by the second embodiment of the present application, Figure 7 A is a sectional view after a cross section is hatched, Figure 7 B is a sectional view indicating orientation of anisotropic magnetic particles in a magnetic layer.

[0042] [ Figure 8 ] Figure 8 A ~ Figure 8 C is a process chart of a manufacturing method of the inductor of the second embodiment, Figure 8 A indicates a first process of disposing a wiring on a first release sheet, Figure 8 B indicates a second process of covering the wiring with the first magnetic sheet, Figure 8C indicates a third process of removing the first release sheet.

[0043] [ Figure 9 ] Figure 9 D ~ Figure 9 F is next Figure 8 C continues to explain the process chart of the manufacturing method of the inductor of the second embodiment, Figure 9 D indicates a process of disposing the second magnetic sheet and the third magnetic sheet, Figure 9 E indicates a fourth process of covering one side surface of the first magnetic sheet with the second magnetic sheet and a fifth process of covering the other side surface of the first magnetic sheet of the C stage with the third magnetic sheet, Figure 9 F indicates a process of taking out the inductor.

[0044] [ Figure 10 ] Figure 10 A ~ Figure 10 C is a process chart of the manufacturing method of the modification of the second embodiment, Figure 10 A indicates a first process of disposing a wiring on the first release sheet, Figure 10 B indicates a second process of covering the wiring with the first magnetic sheet, Figure 10 C indicates a process of disposing the second magnetic sheet.

[0045] [ Figure 11 ] Figure 11 D ~ Figure 11 F is next Figure 10 C continues to explain the process chart of the manufacturing method of the modification of the second embodiment, Figure 11 D indicates a fourth process of covering one side surface of the first magnetic sheet with the second magnetic sheet, Figure 11 E indicates a third process of removing the first release sheet, Figure 11 F indicates a process of disposing the third magnetic sheet.

[0046] [ Figure 12 ] Figure 12 G ~ Figure 12 H is next as Figure 11 F continues to explain the process chart of the manufacturing method of the modification of the second embodiment, Figure 12 G indicates a fifth process of covering the other side surface of the first magnetic sheet of the C stage with the third magnetic sheet, Figure 12 H indicates a process of taking out the inductor.

[0047] [ Figure 13 ] Figure 13 A ~ Figure 13 C is a process chart of the manufacturing method of the further modification of the second embodiment, Figure 13 A indicates a process of disposing a wiring on the C stage of the third magnetic sheet, Figure 13B indicates a step of covering the wiring and one side surface of the third magnetic sheet with the first magnetic sheet, Figure 13 C indicates a step of disposing the second magnetic sheet.

[0048] [ Figure 14 ] Figure 14 D ~ Figure 14 E is then Figure 13 C continues to explain the process chart of the manufacturing method of the further modification of the second embodiment, Figure 14 D indicates a step of covering the first magnetic sheet with the second magnetic sheet, Figure 14 E indicates a step of taking out the inductor.

[0049] [ Figure 15 ] Figure 15 A ~ Figure 15 C is a sectional view of a modification of the manufacturing method of the inductor, Figure 15 A indicates a step of disposing the wiring on one side surface of the first release sheet with the pressure-sensitive adhesive layer, Figure 15 B indicates a step of covering the area exceeding 180° in cross section on the circumferential surface of the wiring and one side surface of the first release sheet with the first magnetic sheet, Figure 15 C indicates a step of obtaining the inductor.

[0050] [ Figure 16 ] Figure 16 A ~ Figure 16 C is a sectional view of a modification of the manufacturing method of the inductor, Figure 16 A is a step of disposing the wiring in a manner of being separated by a gap from the first release sheet, Figure 16 B is a step of covering the circumferential surface of the wiring and one side surface of the first release sheet with the first magnetic sheet, Figure 16 C indicates a step of obtaining the inductor.

[0051] [ Figure 17 ] Figure 17 A ~ Figure 17 B is an image processing chart of the SEM photograph of Example 1, Figure 17 A is an SEM photograph after the second step, Figure 17 B is an SEM photograph of the inductor.

[0052] Figure 18 is an image processing chart of the SEM photograph of the inductor of Example 2.

[0053] Figure 19 is an image processing chart of the SEM photograph of the inductor of Comparative Example 1. DETAILED DESCRIPTION

[0054] <1st Embodiment>

[0055] 1. An inductor

[0056] Reference Figure 1 A Figure 2 B to explain the inductor obtained by the first embodiment of the present application.

[0057] Further, Figure 1 A cross section is hatched and shown, Figure 1 B is a cross-sectional view showing the orientation of the anisotropic magnetic particles in the magnetic layer. Further, in the drawings of the present application including Figure 1 B, the shape and arrangement of the magnetic particles (including the anisotropic magnetic particles) are exaggerated for easy understanding of the present application.

[0058] As Figure 1 A Figure 1 B shows, the inductor 1 has a shape extending in a planar direction. Specifically, the inductor 1 has one side surface and another side surface opposite in a thickness direction, and each of the one side surface and the other side surface has a flat shape in a direction included in the planar direction and orthogonal to both a direction in which a wiring 2 (to be described later) transmits a current (corresponding to a paper depth direction) and the thickness direction.

[0059] The inductor 1 includes the wiring 2 and a magnetic layer 3.

[0060] The wiring 2 has a shape that is substantially circular in cross section. Specifically, the wiring 2 has a substantially circular shape when cut in a cross section (a first direction cross section) orthogonal to a second direction (a transmission direction) in which a current is transmitted (a paper depth direction).

[0061] The wiring 2 is a wire covered with an insulating layer, and specifically includes a conductor wire 6 and an insulating layer 7 covering the conductor wire 6.

[0062] The conductor wire 6 is a conductor wire having a shape elongated in the second direction. In addition, the conductor wire 6 has a shape that is substantially circular in cross section with a common central axis as the wiring 2.

[0063] As a material of the conductor wire 6, for example, a metal conductor such as copper, silver, gold, aluminum, nickel, and an alloy thereof is cited, and copper is preferably cited. The conductor wire 6 can be a single layer structure, or a multilayer structure in which plating (for example, nickel) or the like is performed on the surface of a core conductor (for example, copper).

[0064] The radius R1 of the conductor wire 6 is, for example, 25 μm or more, and preferably 50 μm or more, and is, for example, 2000 μm or less, and preferably 200 μm or less.

[0065] The insulating layer 7 protects the conductor wire 6 from chemicals and water, and prevents short circuit between the conductor wire 6 and the magnetic layer 3. The insulating layer 7 covers the entire outer peripheral surface (entire circumferential surface) of the conductor wire 6.

[0066] The insulating layer 7 has a shape of a substantially circular ring in cross section, which shares a central axis (center C) with the wiring 2.

[0067] As a material of the insulating layer 7, for example, insulating resins such as polyvinyl formal, polyester, polyester imide, polyamide (including nylon), polyimide, polyamide imide, polyurethane, etc. are cited. They can be used singly or in combination of two or more.

[0068] The insulating layer 7 can be composed of a single layer or a plurality of layers.

[0069] The thickness R2 of the insulating layer 7 is substantially uniform in the radial direction of the wiring 2 at any position in the circumferential direction, for example, 1 μm or more, preferably 3 μm or more, and, for example, 100 μm or less, preferably 50 μm or less.

[0070] The ratio (R1 / R2) of the radius R1 of the conductor 6 to the thickness R2 of the insulating layer 7 is, for example, 1 or more, preferably 10 or more, and, for example, 500 or less, preferably 100 or less.

[0071] The radius R of the wiring 2 (= the radius R1 of the conductor 6 + the thickness R2 of the insulating layer 7) is, for example, 25 μm or more, preferably 50 μm or more, and, for example, 2000 μm or less, preferably 200 μm or less.

[0072] 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 surface direction (the first direction and the second direction). More specifically, the magnetic layer 3 has one side surface and the other side surface opposite 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.

[0073] 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 the anisotropic magnetic particles 8 and the binder 9. Preferably, the magnetic layer 3 is a cured body of a thermosetting resin composition (a composition containing the anisotropic magnetic particles 8 and a thermosetting component described later).

[0074] As a magnetic material constituting the anisotropic magnetic particles 8, for example, soft magnetic bodies and hard magnetic bodies are cited. From the viewpoint of inductance, it is preferable to cite soft magnetic bodies.

[0075] As the soft magnetic body, for example, a single metal body containing one kind of metal element in a pure substance state, an alloy body which is a eutectic mixture (mixture) of one or more kinds of metal elements (first metal element) and one or more kinds of metal elements (second metal element) and / or non-metal elements (carbon, nitrogen, silicon, phosphorus, etc.) are exemplified. They can be used alone or in combination.

[0076] As the single metal body, for example, a metal element consisting of only one kind of metal element (first metal element) is exemplified. As the first metal element, for example, one is appropriately selected from iron (Fe), cobalt (Co), nickel (Ni), and metal elements which can be contained as the first metal element of the soft magnetic body.

[0077] In addition, as the single metal body, for example, a form having a core containing only one kind of metal element and a surface layer of inorganic matter and / or organic matter which modifies part or all of the surface of the core, a form of an organic metal compound containing the first metal element, a form after decomposition (thermal decomposition, etc.) of an inorganic metal compound, etc. are exemplified. As the latter form, more specifically, an iron powder (sometimes referred to as a carbonyl iron powder) after thermal decomposition of an organic iron compound (specifically, a carbonyl iron) containing iron as the first metal element, etc. are exemplified. Furthermore, the position of the layer of inorganic matter and / or organic matter which modifies the part containing only one kind of metal element is not limited to the surface as described above. Furthermore, as the organic metal compound and the inorganic metal compound from which the single metal body can be obtained, there is no particular limitation, and one can be appropriately selected from known or conventional organic metal compounds and inorganic metal compounds from which the single metal body of the soft magnetic body can be obtained.

[0078] The alloy body is a eutectic mixture of one or more kinds of metal elements (first metal element) and one or more kinds of metal elements (second metal element) and / or non-metal elements (carbon, nitrogen, silicon, phosphorus, etc.), and there is no particular limitation as long as it can be used as the soft magnetic body.

[0079] The first metal element is an essential element in the alloy body, and for example, iron (Fe), cobalt (Co), nickel (Ni), etc. are exemplified. Furthermore, if the first metal element is Fe, the alloy body is an Fe-based alloy, if the first metal element is Co, the alloy body is a Co-based alloy, and if the first metal element is Ni, the alloy body is a Ni-based alloy.

[0080] The second metal element is an element (subcomponent) that is contained in the alloy body in a small amount, and is a metal element that is compatible (eutectic) with the first metal element, such as iron (Fe) (in the case where the first metal element is other than Fe), cobalt (Co) (in the case where the first metal element is other than Co), nickel (Ni) (in the case where the first 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), various rare earth elements, and the like. They can be used alone or in combination with two or more.

[0081] The nonmetal element is an element (subcomponent) that is contained in the alloy body in a small amount, and is a nonmetal element that is compatible (eutectic) with the first metal element, such as boron (B), carbon (C), nitrogen (N), silicon (Si), phosphorus (P), sulfur (S), and the like. They can be used alone or in combination with two or more.

[0082] As an example of the alloy body, Fe-based alloys such as magnetic stainless steel (Fe-Cr-Al-Si alloy) (including electromagnetic stainless steel), iron-silicon-aluminum alloy (Fe-Si-Al alloy) (including super iron-silicon-aluminum alloy), permalloy (Fe-Ni alloy), Fe-Ni-Mo alloy, Fe-Ni-Mo-Cu alloy, Fe-Ni-Co alloy, Fe-Cr alloy, Fe-Cr-Al alloy, Fe-Ni-Cr alloy, Fe-Ni-Cr-Si alloy, 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-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-based ferrite, and Mn-Mg-based ferrite, Mn-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Zn-Cu-based ferrite, Cu-Zn-based ferrite, Cu-Mg-Zn-based ferrite, and the like, soft magnetic ferrite), Permalloy (Fe-Co alloy), Fe-Co-V alloy, Fe-based amorphous alloy, and the like.

[0083] As an example of the alloy body, Co-based alloys such as Co-Ta-Zr, cobalt (Co)-based amorphous alloy, and the like.

[0084] As an example of the alloy body, a Ni-based alloy such as a Ni-Cr alloy is given.

[0085] Among these soft magnetic bodies, from the viewpoint of magnetic properties, an alloy body is preferably given, a Fe-based alloy is more preferably given, and a Fe-Si-Al alloy is further preferably given. In addition, as the soft magnetic body, a single metal body is preferably given, a single metal body containing an iron element in a pure substance state is more preferably given, and iron single substance or iron powder (carbonyl iron powder) is further preferably given.

[0086] As the shape of the anisotropic magnetic particle 8, from the viewpoint of anisotropy, a flat shape (a plate shape), a needle shape, or the like is given, and from the viewpoint of good relative permeability in the planar direction (two dimensions), a flat shape is preferably given.

[0087] The flat ratio (flatness) of the flat anisotropic magnetic particle 8 is, for example, 8 or more, preferably 15 or more, and is, for example, 500 or less, preferably 450 or less. The flat ratio is calculated as the ratio of the average particle diameter (average length) (described later) of the anisotropic magnetic particle 8 to the average thickness of the anisotropic magnetic particle 8.

[0088] The average particle diameter (average length) of the anisotropic magnetic particle 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. If the anisotropic magnetic particle 8 is 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.

[0089] The binder 9 disperses the anisotropic magnetic particle 8 in the magnetic layer 3. In addition, the binder 9 is dispersed in the magnetic layer 3 in a predetermined direction. It is preferable that the binder 9 contain a cured product of a B-stage thermosetting component. Furthermore, the binder 9 is described in detail in the description of the first magnetic sheet 51, the second magnetic sheet 52, and the third magnetic sheet 53 in the manufacturing method described later.

[0090] In the magnetic layer 3, the anisotropic magnetic particle 8 is oriented and uniformly arranged in the binder 9.

[0091] The magnetic layer 3 has a peripheral region 4 and an outer region 5 when sectioned (when sectioned with a cross section in the first direction).

[0092] The peripheral region 4 is a peripheral region of the wiring 2, and is located around the wiring 2 in a manner in contact with the entire outer circumferential surface (entire circumferential surface) of the wiring 2. The peripheral region 4 has a shape of a substantially circular ring in cross section sharing the central axis with the wiring 2. More specifically, the peripheral region 4 is a region in the magnetic layer 3 located within a range of a distance of 1.5 times the radius R of the wiring 2 from the center C 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 edge (inner edge of the peripheral region 4) of the wiring 2 to the radially outer side.

[0093] The peripheral region 4 includes a first region 11 and a second region 12.

[0094] The first region 11 is provided at intervals in the circumferential direction in the peripheral region 4. More specifically, the first region 11 includes a third region 13 and a fourth region 14 provided at an interval on the other side in the thickness direction from the third region 13.

[0095] The third region 13 covers at least an outer circumferential arc surface including the thickness direction one end edge E1 of the wiring 2, for example, at least a partial or entire first semicircular arc surface 23 including the thickness direction one end edge E1 of the wiring 2. It is preferable that the third region 13 cover a partial of the above-mentioned first semicircular arc surface 23 of the wiring 2, and more specifically, when projected in the radial direction, the third region 13 is included in one semicircular arc surface of the wiring 2, and on the other hand, the third region 13 does not overlap the first direction both end edges E2, E3 of the wiring 2, but is provided inside the first direction both end edges E2, E3.

[0096] Further, the thickness direction one end edge E1 of the wiring 2 is a portion where the arc surface (first semicircular arc surface 23) on the thickness direction one side of the wiring 2 intersects with a first imaginary line L1 passing through the center C of the wiring 2 in the thickness direction.

[0097] In addition, the first direction both end edges E2, E3 of the wiring 2 are two portions where the circumferential surface of the wiring 2 intersects with a third imaginary line L3 passing through the center C of the wiring 2 in the first direction.

[0098] The fourth region 14 is disposed opposite the third region 13 with respect to the center C of the wiring 2. The fourth region 14 covers at least the outer circumferential arc surface including the other end edge E4 in the thickness direction of the wiring 2, for example, a portion of the second semicircular arc surface 24 including the other end edge E4 in the thickness direction of the wiring 2. Specifically, the fourth region 14 includes the second semicircular arc surface 24 when projected in the radial direction, and on the other hand, the fourth region 14 does not overlap the first direction end edges E2, E3 of the wiring 2, but is disposed inside the first direction end edges E2, E3 of the wiring 2.

[0099] The other end edge E4 in the thickness direction of the wiring 2 is a portion where the second semicircular arc surface 24 intersects with the first imaginary line L1 passing through the center C of the wiring 2 in the thickness direction.

[0100] The angle αl of the central angle C1 of the third region 13 and the angle α2 of the central angle C2 of the fourth region 14 are each appropriately set according to the use and purpose, and the total angle (αl + α2) is, for example, less than 360°, and preferably 270° or less, and on the other hand, for example, more than 180°, and preferably 200° or more.

[0101] Specifically, the angle αl of the central angle C1 of the third region 13 is, for example, 90° or more, preferably more than 90°, and more preferably 120° or more, and on the other hand, for example, less than 180°, and preferably 165° or less. In addition, the angle αl is preferably an obtuse angle.

[0102] The angle α2 of the central angle C2 of the fourth region 14 is, for example, 15° or more, and on the other hand, for example, 60° or less, and preferably 45° or less. In addition, the angle α2 is preferably an acute angle.

[0103] The angle αl of the central angle C1 of the third region 13 is larger than the angle α2 of the central angle C2 of the fourth region 14, and the ratio (angle αl / angle α2) is, for example, more than 1, and preferably 1.5 or more, and on the other hand, 3 or less, and preferably 2 or less.

[0104] In the first region 11, the anisotropic magnetic particles 8 are oriented in the circumferential direction of the wiring 2.

[0105] In each of the third region 13 and the fourth region 14, the direction in which the relative magnetic permeability of the anisotropic magnetic particles 8 is high (for example, the surface direction of the anisotropic magnetic particles 8 if the anisotropic magnetic particles 8 are flat) is substantially aligned with the circumferential direction. Specifically, the case where the angle formed by the surface direction of the anisotropic magnetic particles 8 and the tangent line that is tangent to the circumferential surface opposite the anisotropic magnetic particles 8 on the inner side in the radial direction is 15 degrees or less is defined as the orientation of the anisotropic magnetic particles 8 in the circumferential direction.

[0106] The proportion of the number of the circumferentially oriented anisotropic magnetic particles 8 with respect to the number of the anisotropic magnetic particles 8 contained in the first region 11 as a whole exceeds 50%, preferably 70% or more, and more preferably 80% or more. That is, in the first region 11, it can be that less than 50% of the anisotropic magnetic particles 8 are not oriented in the circumferential direction, preferably 30% or less of the anisotropic magnetic particles 8 are not oriented in the circumferential direction, and more preferably 20% or less of the anisotropic magnetic particles 8 are not oriented in the circumferential direction.

[0107] The proportion of the area of the first region 11 (the total area of the third region 13 and the fourth region 14) with respect to the area of the entire peripheral region 4 is, for example, 40% or more, preferably 50% or more, and more preferably 60% or more, and, for example, 90% or less, and preferably 80% or less.

[0108] The relative permeability in the circumferential direction of the first region 11 is, for example, 5 or more, preferably 10 or more, and 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, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. Further, the ratio of the relative permeability in the circumferential direction with respect 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. If the relative permeability is within the above range, the inductance is excellent.

[0109] The relative permeability can be measured, for example, by using an impedance analyzer (manufactured by Agilent, "4291B") with a magnetic material test jig.

[0110] The second region 12 is a circumferential direction 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 second region 12, the anisotropic magnetic particles 8 are not oriented or oriented in a direction other than the circumferential direction of the wiring 2 (for example, the first direction, the radial direction).

[0111] The second regions 12 are arranged at intervals in the circumferential direction in the peripheral region 4. Specifically, the second regions 12 include a fifth region 15 and a sixth region 16 arranged at intervals in the circumferential direction in such a manner that the first imaginary straight line L1 passing through the thickness direction one end edge E1 and the other end edge E4 of the wiring 2 is sandwiched therebetween.

[0112] The 5th region 15 is disposed on the one side in the 1st direction with respect to the 1st imaginary straight line L1. The 5th region 15 is sandwiched between the one circumferential end surface of the 3rd region 13 and the other circumferential end surface of the 4th region 14, and specifically, the 5th region 15 is continuous with the one circumferential end surface of the 3rd region 13 and the other circumferential end surface of the 4th region 14, respectively.

[0113] The 6th region 16 is disposed on the other side in the 1st direction with respect to the 1st imaginary straight line L1 in a manner spaced apart from the 5th region 15. The 6th region 16 is disposed on the other side in the 1st direction with respect to the 1st imaginary straight line L1, and the 6th region 16 is line-symmetrical to the 5th region 15 with the 1st imaginary straight line L1 as an axis. That is, the 6th region 16 is continuous with the other circumferential end surface of the 3rd region 13 and the one circumferential end surface of the 4th region 14, respectively.

[0114] Thus, in the 1st region 11, the 3rd region 13, the 5th region 15, the 4th region 14, and the 6th region 16 are disposed in the circumferential direction in this order.

[0115] Also, the center C of the wiring 2 is not present on a 2nd imaginary straight line L2 that is one example of an imaginary straight line, the 2nd imaginary straight line L2 connecting a center C3 of a 1st imaginary circular arc Al that is one example of an imaginary circular arc and a center C4 of a 2nd imaginary circular arc A2 that is one example of an imaginary circular arc, the 1st imaginary circular arc Al connecting a 1st end E5 that is a circumferential direction one end in the 5th region 15 and a 2nd end E6 that is a circumferential direction other end, the 2nd imaginary circular arc A2 connecting a 3rd end E7 that is a circumferential direction one end in the 6th region 16 and a 4th end E8 that is a circumferential direction other end.

[0116] Further, the 1st end E5 is a portion of the radially central portion of the circumferential direction one end surface in the 5th region 15. The 2nd end E6 is a portion of the radially central portion of the circumferential direction other end surface in the 5th region 15. The 3rd end E7 is a portion of the radially central portion of the circumferential direction one end surface in the 6th region 16. The 4th end E8 is a portion of the radially central portion of the circumferential direction other end surface in the 6th region 16.

[0117] Specifically, the center C of the wiring 2 is disposed on the one side in the thickness direction of the 2nd imaginary straight line L2 in a manner spaced apart from the 2nd imaginary straight line L2.

[0118] In detail, the center C of the wiring 2 is located, for example, at a position on the one side in the thickness direction from the 2nd imaginary straight line L2 by an amount of distance that is 0.2 times or more and 0.7 times or less of the radius R of the wiring 2, and preferably at a position on the one side in the thickness direction from the 2nd imaginary straight line L2 by an amount of distance that is 0.3 times or more and 0.5 times or less of the radius R of the wiring 2.

[0119] Further, the thickness direction other end edge E4 of the wiring 2 is not present on the 2nd imaginary straight line L2, and specifically, the thickness direction other end edge E4 of the wiring 2 is present on the thickness direction other side of the 2nd imaginary straight line L2 at a spacing apart from the 2nd imaginary straight line L2.

[0120] Further, in the 2nd region 12 (each of the 5th region 15 and the 6th region 16), a cross portion (a top portion) 20 is formed by at least two kinds of anisotropic magnetic particles 8 different in orientation direction. For example, in the 5th region 15, a 1st particle 17 which is an anisotropic magnetic particle 8 oriented to the radial direction outside of the wiring 2 as going from a 1st end E5 (a portion in contact with the 3rd region 13) toward a 2nd end E6 (a portion in contact with the 4th region 14) and a 2nd particle 18 which is an anisotropic magnetic particle 8 oriented in the 1st direction as going from the 2nd end E6 toward the 1st end E5 constitute at least two sides of a substantially triangular shape, and thereby, a 1st cross portion (a 1st top portion) 21 is formed. Specifically, the 1st particle 17 and the 2nd particle 18 form a substantially triangular shape (preferably, an acute triangle shape) together with a 3rd particle 19 which is an anisotropic magnetic particle 8 oriented in the circumferential direction in the region of the 5th region 15 closest to the wiring 2.

[0121] Further, in the 6th region 16, a 1st particle 17 which is an anisotropic magnetic particle 8 oriented to the radial direction outside of the wiring 2 as going from a 4th end E8 (a portion in contact with the 3rd region 13) toward a 3rd end E7 (a portion in contact with the 4th region 14) and a 2nd particle 18 which is an anisotropic magnetic particle 8 oriented in the 1st direction as going from the 3rd end E7 toward the 4th end E8 constitute at least two sides of a substantially triangular shape, and thereby, a 2nd cross portion (a 2nd top portion) 22 is formed. Specifically, the 1st particle 17 and the 2nd particle 18 form a substantially triangular shape (preferably, an acute triangle shape) together with a 3rd particle 19 which is an anisotropic magnetic particle 8 oriented in the circumferential direction in the region of the 6th region 16 closest to the wiring 2.

[0122] The cross portion 20 (each of the 1st cross portion 21 and the 2nd cross portion 22) does not overlap the center C of the wiring 2 when projected in the 1st direction. Specifically, the cross portion 20 is disposed at a position on the thickness direction other side of the center C of the wiring 2 at a spacing apart from the center C of the wiring 2 when projected in the 1st direction.

[0123] Further, the cross portion 20 is disposed on the thickness direction one side of the thickness direction other end edge E4 of the wiring 2 at a spacing apart from the thickness direction other end edge E4 of the wiring 2 when projected in the 1st direction.

[0124] In the 2nd region 12 (5th region 15 and 6th region 16), the direction in which the relative magnetic permeability of the anisotropic magnetic particles 8 is high (for example, the surface direction of the particles in the case of flat anisotropic magnetic particles) is not aligned with the tangent to the circumferential surface centered on the center C of the wire 2. More specifically, the case where the angle formed by the surface direction of the anisotropic magnetic particles 8 and the outer circumferential surface (circumferential surface) of the wire 2 in which the anisotropic magnetic particles 8 are present exceeds 15 degrees is defined as the case where the anisotropic magnetic particles 8 are not oriented in the circumferential direction.

[0125] The proportion of the number of the anisotropic magnetic particles 8 that are not oriented in the circumferential direction with respect to the total number of the anisotropic magnetic particles 8 included in the 2nd region 12 is, for example, more than 50%, preferably 70% or more, and is, for example, 95% or less, preferably 90% or less.

[0126] In the 2nd region 12, for example, the anisotropic magnetic particles 8 that are oriented in the circumferential direction can also be included. The proportion of the number of the anisotropic magnetic particles 8 that are oriented in the circumferential direction with respect to the total number of the anisotropic magnetic particles 8 included in the 2nd region 12 is, for example, less than 50%, preferably 30% or less, and is, for example, 5% or more, preferably 10% or more.

[0127] Further, in the case where the anisotropic magnetic particles 8 that are oriented in the circumferential direction are included, it is preferable that the anisotropic magnetic particles 8 that are oriented in the circumferential direction be disposed in the innermost region of the 2nd region 12, that is, in the vicinity of the surface of the wire 2.

[0128] The proportion of the area of the 2nd region 12 (total area of the 5th region 15 and the 6th region 16) with respect to the area of the entire peripheral region 4 is, for example, 10% or more, preferably 20% or more, and is, for example, 60% or less, preferably 50% or less, more preferably 40% or less.

[0129] Also, in the peripheral region 4, the filling rate (proportion of presence) of the anisotropic magnetic particles 8 is, for example, 40% by volume or more, preferably 45% by volume or more, more preferably 50% by volume or more, further preferably 55% by volume or more, and particularly preferably 60% by volume or more. If the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 is the above lower limit or more, an inductor 1 having excellent inductance can be obtained.

[0130] Further, the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4 is, for example, 95% by volume or less, preferably 90% by volume or less. If the filling rate of the anisotropic magnetic particles 8 is the above upper limit or less, the inductor 1 has excellent mechanical strength.

[0131] In particular, in each of the first region 11 and the second region 12, the filling rate of the anisotropic magnetic particles 8 is, for example, 40% or more by volume, preferably 45% or more by volume, more preferably 50% or more by volume, further preferably 55% or more by volume, particularly preferably 60% or more by volume, and, for example, 95% or less by volume, preferably 90% or less by volume.

[0132] Further, the filling rate of the anisotropic magnetic particles 8 in the first region 11 and the filling rate of the anisotropic magnetic particles 8 in the second region 12 can be the same or different.

[0133] The filling rate of the anisotropic magnetic particles 8 can be calculated by measurement of the actual specific gravity, binarization of a SEM photograph, or the like.

[0134] On the other hand, the proportion of the binder 9 present in the peripheral region 4 is, for example, the remaining portion of the above-described filling rate of the anisotropic magnetic particles 8.

[0135] Further, in the peripheral region 4, the formation of voids (gaps, spaces) is suppressed as much as possible, and preferably, there are no voids between the wiring 2 and the magnetic layer 3. That is, the peripheral region 4 is preferably void-free.

[0136] The outer region 5 is a region in the magnetic layer 3 other than the peripheral region 4. The outer region 5 is disposed outside the peripheral region 4 in a continuous manner with the peripheral region 4.

[0137] In the outer region 5, the anisotropic magnetic particles 8 are oriented along the planar direction (particularly, the first direction).

[0138] In the outer region 5, the direction in which the relative magnetic permeability of the anisotropic magnetic particles 8 is high (for example, the planar direction of the particles in the case of flat anisotropic magnetic particles) is substantially coincident with the first direction. More specifically, the case where the angle formed by the planar direction of the anisotropic magnetic particles 8 and the first direction is 15° or less is defined as the orientation of the anisotropic magnetic particles 8 along the first direction.

[0139] In the outer region 5, the proportion of the number of the anisotropic magnetic particles 8 oriented along the first direction with respect to the total number of the anisotropic magnetic particles 8 contained in the outer region 5 exceeds 50%, preferably 70% or more, more preferably 90% or more. That is, in the outer region 5, it can be that less than 50% of the anisotropic magnetic particles 8 are not oriented along the first direction, preferably 30% or less of the anisotropic magnetic particles 8 are not oriented along the first direction, and more preferably 10% or less of the anisotropic magnetic particles 8 are not oriented along the first direction.

[0140] In addition, the filling rate of the anisotropic magnetic particles 8 in the outer region 5 can be the same as or different from the filling rate of the anisotropic magnetic particles 8 in the peripheral region 4.

[0141] In the outer region 5, the relative magnetic permeability in the first direction is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and, for example, 500 or less. The relative magnetic permeability in the thickness direction is, for example, 1 or more, preferably 5 or more, and, for example, 100 or less, preferably 50 or less, more preferably 25 or less. In addition, the ratio of the relative magnetic permeability in the first direction to the relative magnetic permeability in the thickness direction (first direction / thickness direction) is, for example, 2 or more, preferably 5 or more, and, for example, 50 or less.

[0142] In the outer region 5, the filling rate of the anisotropic magnetic particles 8 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, for example, 95 vol% or less, preferably 90 vol% or less.

[0143] The thickness of the magnetic layer 3 is, for example, twice 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, for example, 2000 μm or less, preferably 1000 μm or less. Note that the thickness of the magnetic layer 3 is the distance between one side surface and the other side surface of the magnetic layer 3.

[0144] 2. Method for manufacturing an inductor

[0145] Reference Figure 2 A ~ Figure 3 F will be described.

[0146] The method for manufacturing the inductor 1 includes a first process to a sixth process. In the method for manufacturing the inductor 1, the first process, the second process, and the third process are sequentially performed, and then the fourth process, the fifth process, and the sixth process are simultaneously performed.

[0147] (First Process)

[0148] As shown in Figure 2 A, in the first process, first, the wiring 2 and the first release sheet 41 as a release film, which is one example of a substrate, are prepared.

[0149] The first release sheet 41 has a substantially sheet shape extending in a planar direction. The material of the first release sheet 41 is appropriately selected according to its use and purpose, and specifically, a polyester such as polyethylene terephthalate (PET), a polyolefin such as polymethylpentene or polypropylene, or the like is cited. In addition, the thickness direction one side surface and / or the other side surface of the first release sheet 41 can also be subjected to a release treatment. The thickness of the first release sheet 41 is, for example, 1 μm or more, and for example, 1000 μm or less.

[0150] After that, in the first process, the wiring 2 and the first release sheet 41 are disposed in the flat press 42.

[0151] The flat press 42 includes a first plate 43 and a second plate 44 capable of being pressurized in the thickness direction. In the flat press 42, the second plate 44 is disposed on the thickness direction one side of the first plate 43 in a manner spaced apart. In addition, the flat press 42 includes a heat source not shown.

[0152] In addition, a chamber for bringing members disposed in the flat press 42 and used for pressurization to a vacuum state is provided in the flat press 42.

[0153] In the first process, first, the first release sheet 41 is disposed on the first plate 43, and then the wiring 2 is disposed on the thickness direction one side surface of the first release sheet 41. Specifically, the thickness direction other end edge E4 of the wiring 2 is brought into contact with the one side surface of the first release sheet 41.

[0154] In addition, at this time, the first release sheet 41 and the first plate 43 are disposed in the chamber. Each member disposed in the subsequent processes is also disposed in the chamber.

[0155] (Second Process)

[0156] In the second process, first, as shown in FIG. 2A, the first magnetic sheet 51 is prepared. At the same time, the second release sheet 45 and the release gasket 46 are prepared. Figure 2 A

[0157] [First Magnetic Sheet]

[0158] The first magnetic sheet 51 has a substantially sheet shape extending in a planar direction. Specifically, the first magnetic sheet 51 has a thickness direction one side surface and a thickness direction other side surface.

[0159] The first magnetic sheet 51 is a magnetic sheet for forming at least the second region 12, the third region 13 (part or all of), and part of the outer region 5 of the magnetic layer 3.

[0160] In addition, the first magnetic sheet 51 is configured to be deformed (flow) by heat press in the second process (refer to Figure 2 B).

[0161] Further, the first magnetic sheet 51 contains the first anisotropic magnetic particles 81 as one example of the first magnetic particles and the first binder 91. The first anisotropic magnetic particles 81 are the same as the anisotropic magnetic particles 8. Specifically, the first magnetic sheet 51 is formed in a substantially sheet shape from a first magnetic composition containing the first anisotropic magnetic particles 81 and the first binder 91.

[0162] In the first magnetic sheet 51, the first anisotropic magnetic particles 81 are uniformly dispersed by the first binder 91 in a manner oriented in a surface direction.

[0163] The first magnetic sheet 51 is a single sheet or a laminate (laminate sheet) of a plurality of sheets, preferably a laminate sheet, and more preferably a two-layer sheet composed of an inner sheet 54 which is in contact with the wiring 2 at the time of hot pressing and an outer sheet 55 which is disposed on one side in the thickness direction of the inner sheet 54.

[0164] The volume ratio of the first anisotropic magnetic particles 81 in the first magnetic composition (the first 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, and 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 first anisotropic magnetic particles 81 is within the above range, the first anisotropic magnetic particles 81 can be densely disposed in the peripheral region 4. As a result, an inductor 1 having excellent inductance can be obtained.

[0165] Further, the volume ratio of the first anisotropic magnetic particles 81 in the first magnetic composition (the first magnetic sheet 51) can be, for example, 40 vol% or less, further 35 vol% or less, and is, for example, 20 vol% or more, further 25 vol% or more. If the volume ratio of the first 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 first anisotropic magnetic particles 81 can be densely disposed in the peripheral region 4 together with the second anisotropic magnetic particles 82 and the third anisotropic magnetic particles 83 (described later). As a result, an inductor 1 having excellent inductance can be obtained.

[0166] If the first magnetic sheet 51 is a two-layer laminate composed of the inner sheet 54 and the outer sheet 55, the volume ratio of the anisotropic magnetic particles 8 in the outer sheet 55 is preferably higher than the volume of the anisotropic magnetic particles 8 in the inner sheet 54. If so arranged, the first magnetic sheet 51 can more softly follow the region (hereinafter referred to as an optimal arc) of more than 180° in cross section on the circumferential surface of the wiring 2.

[0167] As the first binder 91, a thermoplastic component such as an acrylic resin, and a thermosetting component such as an epoxy resin composition are cited. The acrylic resin includes, for example, a carboxyl group-containing acrylate copolymer. The epoxy resin composition includes, for example, an epoxy resin (a cresol novolak type epoxy resin or the like) as a main agent, a curing agent for epoxy resin (a phenol resin or the like), and a curing accelerator for epoxy resin (an imidazole compound or the like).

[0168] As the first binder 91, a thermoplastic component and a thermosetting component can be used individually or in combination, and the combination of the thermoplastic component and the thermosetting component is preferable.

[0169] That is, it is preferable that the first binder 91 contains at least a thermosetting component. If the first binder 91 contains at least a thermosetting component, the first magnetic sheet 51 can be made into a B-stage having fluidity, and the first anisotropic magnetic particles 81 can be uniformly dispersed at a high compounding ratio, and in the heat pressing of the second process, the first magnetic sheet 51 can be deformed softly and cover the convex arc of the circumference of the wiring 2.

[0170] Further, a further detailed formulation of the first binder 91 (first magnetic composition) is described in Japanese Patent Application Publication No. 2014-165363, and the like.

[0171] The volume ratio of the first binder 91 in the first magnetic composition (first magnetic sheet 51) is the remaining portion of the volume ratio of the above-described first anisotropic magnetic particles 81.

[0172] In manufacturing the first magnetic sheet 51, the first anisotropic magnetic particles 81 and the first binder 91 are compounded, and they are uniformly mixed to prepare the first magnetic composition. At this time, as needed, a solvent (organic solvent) is used to prepare a varnish of the first magnetic composition. After that, the varnish is applied to a release film not shown and dried, thereby manufacturing the first magnetic sheet 51.

[0173] The thickness of the first magnetic sheet 51 (total thickness if it is a laminated sheet) is appropriately set in a manner that can maintain the shape of the outer side region 5 capable of covering at least one end edge E1 in the thickness direction of the wiring 2 in the heat pressing of the second process. Specifically, the thickness of the first magnetic sheet 51 is, for example, 3 times or less, preferably 2 times or less, more preferably less than 2 times, further preferably 1.5 times or less, particularly preferably 1.25 times or less, and for example, 0.1 times or more, preferably 0.2 times or more, of the radius R of the wiring 2.

[0174] (Second Release Sheet)

[0175] The second release sheet 45 has the same structure as the first release sheet 41, and the material thereof can be appropriately selected from the above-described materials according to the use and purpose.

[0176] (de-molding shim)

[0177] The de-molding shim 46 is a shim that is used in the hot press in the second process (described later) to de-mold the first magnetic sheet 51 from the second plate 44. Figure 2 C) a de-molding sheet capable of de-molding the first magnetic sheet 51 from the second plate 44.

[0178] In addition, the de-molding shim 46 is also a shim that is used in the hot press in the second process (described later) to de-mold the first magnetic sheet 51 from the second plate 44. Figure 2 B) The de-molding shim 46 disperses and applies the pressure of the second plate 44 to the first magnetic sheet 51 in correspondence with the shape of the major arc of the circumferential surface of the wiring 2, and deforms the first magnetic sheet 51, thereby causing the first magnetic sheet 51 to follow the major arc of the circumferential surface of the wiring 2.

[0179] The de-molding shim 46 has a sheet shape extending in the surface direction, and has a thickness direction one side surface and another side surface.

[0180] In the second process, the one side surface of the de-molding shim 46 is capable of being in contact with the second plate 44 (described later) in a surface-like manner. The one side surface of the de-molding shim 46 is a flat surface in the surface direction.

[0181] The other side surface of the de-molding shim 46 is in contact with the thickness direction one side surface of the second de-molding sheet 45, and is capable of deforming the first magnetic sheet 51. The other side surface of the de-molding shim 46 is disposed opposite to the one side surface of the de-molding shim 46 in the thickness direction with an interval. The other side surface of the de-molding shim 46 is a flat surface parallel to the one side surface of the de-molding shim 46 and in the surface direction.

[0182] The de-molding shim 46 sequentially includes a first layer 47, a second layer 48, and a third layer 49 in the thickness direction.

[0183] (first layer)

[0184] The first layer 47 is a de-molding layer (first de-molding layer) with respect to the first magnetic sheet 51. The first layer 47 is a thin film (outer film) having a shape extending in the surface direction. In addition, the first layer 47 is a covering layer (shell layer) covering the second layer 48 described later from the other side in the thickness direction. An appropriate peeling treatment can be performed on the other side in the thickness direction of the first layer 47.

[0185] In the heat press in the following 2nd process, the 1st layer 47 is able to follow the side surface of the 1st magnetic sheet 51 with the 2nd release sheet 45 interposed, and on the other hand, the 1st layer 47 has physical properties whose thickness does not substantially change before and after the heat press. In addition, the 1st layer 47 is a layer that is able to elongate in the planar direction (specifically, the 1st direction) in the heat press. Furthermore, the 1st layer 47 is harder than the 2nd layer 48 described later at the temperature of the heat press in the 2nd process (for example, 110°C).

[0186] As the material of the 1st layer 47, a non-thermal flow material that flows in the 1st direction under the heat press in the 2nd process described later is cited.

[0187] The non-thermal flow material contains, for example, an aromatic polyester such as polybutylene terephthalate (PBT), and for example, a polyolefin as a main component.

[0188] (2nd layer)

[0189] The 2nd layer 48 is an intermediate layer that is sandwiched between the 1st layer 47 and the 3rd layer 49. The 2nd layer 48 is a flow layer that flows in the 1st direction and the thickness direction at the time of the heat press in the 2nd process to cause the 1st layer 47 to follow the side surface of the 1st magnetic sheet 51.

[0190] The 2nd layer 48 is a soft layer that is softer than the 1st layer 47, and specifically, is able to deform at the time of the heat press in the 2nd process. Specifically, the tensile storage elastic modulus E' of the 2nd layer 48 at 110°C is, for example, lower than the tensile storage elastic modulus E' of the 1st layer 47 at 110°C.

[0191] As the material of the 2nd layer 48, a thermal flow material that flows in the 1st direction and the thickness direction under the heat press in the 2nd process described later is cited. The thermal flow material contains, for example, an olefin-(meth)acrylate copolymer (ethylene-methacrylate copolymer, etc.), an olefin-vinyl acetate copolymer, or the like as a main component.

[0192] (3rd layer)

[0193] The 3rd layer 49 is a release layer (2nd release layer) with respect to the 2nd plate 44. The shape, physical properties, material, and thickness of the 3rd layer 49 are the same as the shape, physical properties, material, and thickness of the 1st layer 47.

[0194] (Thickness of release gasket)

[0195] The thickness of the release gasket 46 is, for example, 50 μm or more and, in addition, for example, 500 μm or less. In addition, the thickness of the first layer 47 and the third layer 49 is, for example, 5 μm or more and 50 μm or less, respectively, and the thickness of the second layer 48 is, for example, 30 μm or more and 300 μm or less. The ratio of the thickness of the second layer 48 to the thickness of the first layer 47 is, for example, 2 or more, preferably 5 or more, and more preferably 7 or more, and in addition, for example, 15 or less.

[0196] For the release gasket 46, a commercially available product can be used, for example, a release film OT series (manufactured by Sekisui Chemical Co., Ltd.) such as a release film OT-A, a release film OT-E, or the like can be used.

[0197] Then, the first release sheet 41, the wire 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 are sandwiched in this order by the flat press 42.

[0198] Next, the wire 2 and the first magnetic sheet 51 are heat-pressed through the first release sheet 41, the second release sheet 45, and the release gasket 46 by the flat press 42.

[0199] For example, the second plate 44 is moved so as to approach the first plate 43, and the second plate 44 is pressed (applied with pressure) to the first magnetic sheet 51 through the release gasket 46 and the second release sheet 45.

[0200] At the same time, the first magnetic sheet 51 and the release gasket 46 are heated by a heat source.

[0201] The pressure application pressure is, for example, 0.1 MPa or more, preferably 0.3 MPa or more, and in addition, for example, 10 MPa or less, preferably 5 MPa or less.

[0202] The heating temperature is, for example, 100°C or more, preferably 105°C or more, and in addition, for example, 190°C or less, preferably 150°C or less.

[0203] The pressure application time is, for example, 10 seconds or more, preferably 20 seconds or more, and in addition, for example, 1000 seconds or less, preferably 100 seconds or less.

[0204] In the second process, the chamber is closed by moving the second plate 44 with respect to the first plate 43, and then, the atmosphere in the chamber is made into a vacuum state, and then, among the first plate 43, the first release sheet 41, the wire 2, the first magnetic sheet 51, the second release sheet 45, the release gasket 46, and the second plate 44, members adjacent in the thickness direction are brought into contact with each other (caulked, tightly attached), and then, the second plate 44 is further moved (heat pressing is started).

[0205] Thus, the overlapping portion 34 of the release gasket 46, which overlaps the wiring 2 when projected in the thickness direction, is sandwiched and pressed (pinched) in the thickness direction by the first semicircular surface 23 of the wiring 2 and the second plate 44.

[0206] On the other hand, the non-overlapping portion 35 of the release gasket 46, which does not overlap the wiring 2 when projected in the thickness direction, is not subjected to the above pinching.

[0207] Thus, the thermal flow material in the portion of the overlapping portion 34 that is in the second layer 48 flows (is extruded) toward the non-overlapping portion 35 (undergoes deformation, specifically, plastic deformation). Thus, for the non-overlapping portion 35, the flow pressure based on the flow (extrusion) of the thermal flow material from the above overlapping portion 34 increases. The flow pressure at the non-overlapping portion 35 acts on both sides in the thickness direction.

[0208] The flow pressure that acts on the other side in the thickness direction in the flow pressure extrudes (presses down) the portion of the non-overlapping portion 35 that is in the first layer 47 toward the other side in the thickness direction, and extrudes (presses down) the extruded portion 38 of the first magnetic sheet 51 that is opposite the non-overlapping portion 35 in the thickness direction toward the other side in the thickness direction through the first layer 47.

[0209] After that, the extrusion (pressing down) of the extruded portion 38 based on the above flow pressure continues until the extruded portion 38 passes around the first directional both end edges E2, E3 of the wiring 2 and further covers (comes into contact with) the second semicircular surface 24 of the wiring 2 (except for the other end edge E4 in the thickness direction, however).

[0210] Then, by the extruded portion 38 coming into contact with the second semicircular surface 24, as shown in Figure 2 B, the second region 12 is formed.

[0211] After the hot pressing, the other side surface of the release gasket 46 has, for example, a shape that corresponds to the first semicircular surface 23 of the wiring 2.

[0212] The second release sheet 45 follows the other side surface of the release gasket 46, specifically, the first layer 47.

[0213] Furthermore, the first magnetic sheet 51 after the hot pressing is, for example, in the B stage. Specifically, the thermosetting component contained in the first binder 91 of the first magnetic sheet 51 is in the B stage.

[0214] Thus, the first magnetic sheet 51 after the hot pressing has a shape that includes at least the above second region 12. That is, as shown in the enlarged view of Figure 2 B, in the second region 12, the anisotropic magnetic particles 8 are not oriented along the circumferential direction of the wiring 2.

[0215] Further, the first magnetic sheet 51 has a raised portion 25 and a flat portion 26.

[0216] 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 curved shape in cross section similar to (or similar to) the first semicircular surface 23. The raised portion 25 has a shape in which the center in the first direction protrudes (is raised) toward the one side in the thickness direction. The raised portion 25 has one second top portion 27.

[0217] The flat portion 26 has a substantially flat plate shape extending from the first direction both end surfaces of the raised portion 25 to the outside in the first direction, respectively.

[0218] Thus, the first magnetic sheet 51 is arranged on the one side in the thickness direction of the first release sheet 41 in a manner to cover the major arc of the peripheral surface of the wiring 2.

[0219] The major arc of the peripheral surface of the wiring 2 is the first semicircular surface 23 and the circular surface (part of the peripheral surface) that extends from the peripheral direction both ends of the first semicircular surface 23 toward the other end edge E4 in the thickness direction along the peripheral direction, but does not reach the other end edge E4 in the thickness direction.

[0220] The thickness of the first magnetic sheet 51 after the heat pressing is set in a manner to ensure the shape having the raised portion 25 and the flat portion 26 described above. Specifically, the ratio of the thickness at the second top portion 27 of the first magnetic sheet 51 to the radius R of the wiring 2 is, for example, 0.01 or more, preferably 0.03 or more, and, for example, 8 or less, preferably 2 or less. The ratio of the thickness of the flat portion 26 to the radius R of the wiring 2 is, for example, 0.05 or more, preferably 0.2 or more, and, for example, less than 5, preferably 1.5 or less.

[0221] Specifically, the thickness at the second top portion 27 of the first magnetic sheet 51 is, for example, 1 μm or more, preferably 5 μm or more, and, for example, 200 μm or less, preferably 100 μm or less. Further, the thickness of the flat portion 26 is, for example, 25 μm or more, preferably 50 μm or more, and, for example, 200 μm or less, preferably 150 μm or less.

[0222] (Third Step)

[0223] In the third step, first, the pressing of the flat press 42 shown in B is released, and then the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 are taken out from the flat press 42. Figure 2 B. Next, as shown in C, the first release sheet 41 is peeled off from the other side surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2.

[0224] Next, as shown in C, the first release sheet 41 is peeled off from the other side surface of the first magnetic sheet 51 and the other end edge E4 in the thickness direction of the wiring 2. Figure 2 ​

[0225] In addition, the second release sheet 45 and the release gasket 46 are peeled from one side surface of the first magnetic sheet 51.

[0226] (4th process, 5th process, and 6th process)

[0227] As shown in FIG. 4, the 4th process, the 5th process, and the 6th process are simultaneously performed. Figure 3 E. In the 4th process, the second magnetic sheet 52 is used to cover the one side surface in the thickness direction of the first magnetic sheet 51. In the 5th process, the third magnetic sheet 53 is used to cover the other side surface in the thickness direction of the first magnetic sheet 51. In the 6th process, the thermosetting components of the first adhesive 91 (see

[0228] Figure 2 A), the second adhesive 92 (see Figure 3 D), and the third adhesive 93 (see Figure 3 D) are phase B.

[0229] As shown in FIG. 4, in the 4th process and the 5th process, first, the second magnetic sheet 52 and the third magnetic sheet 53 are prepared. Figure 3

[0230] The second magnetic sheet 52 and the third magnetic sheet 53 can each have the same structure as the first magnetic sheet 51.

[0231] Further, the second magnetic sheet 52 contains the second anisotropic magnetic particles 82 and the second adhesive 92, and in the second adhesive 92, for example, the second anisotropic magnetic particles 82 are oriented in the surface direction. Since the thermosetting component contained in the second adhesive 92 is in phase B, the second magnetic sheet 52 is in phase B. In addition, if the second magnetic sheet 52 is a laminate (laminated sheet), the presence ratio of the second anisotropic magnetic particles 82 of each sheet can be the same or different, and is preferably the same. In addition, the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 can be the same as or different from the presence ratio of the first anisotropic magnetic particles 81 in the first magnetic sheet 51.

[0232] ​​In the case where the presence ratio of the second anisotropic magnetic particles 82 is different from that of the first anisotropic magnetic particles 81, and the presence ratio of the first anisotropic magnetic particles 81 is 40 vol% or less, the presence ratio of the second anisotropic magnetic particles 82 can be set to be higher than that of the first anisotropic magnetic particles 81. Specifically, the ratio of the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 to that of the first anisotropic magnetic particles 81 in the first magnetic sheet 51 (the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 / the presence ratio of the first anisotropic magnetic particles 81 in the first magnetic sheet 51) is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more, and, for example, 3 or less, preferably 2.5 or less. In this case, specifically, the presence ratio of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 is, for example, 45 vol% or more, preferably 50 vol% or more, more preferably 55 vol% or more, further preferably 60 vol% or more, and, for example, 95 vol% or less, preferably 90 vol% or less.

[0233] If the above ratio and / or presence ratio of the second anisotropic magnetic particles 82 is within the above range, the presence of voids between the second magnetic sheet 52 and the first magnetic sheet 51 can be suppressed as much as possible, and thus the first anisotropic magnetic particles 81 and the second anisotropic magnetic particles 82 can be densely arranged in the peripheral region 4. As a result, an inductor 1 having excellent inductance can be obtained.

[0234] The thickness of the second magnetic sheet 52 (total thickness if it is a laminated sheet) is, for example, 0.5 times or more, preferably 1 times or more, more preferably 1.5 times or more, and, for example, 5 times or less, preferably 3 times or less, of the radius R of the wiring 2.

[0235] The third magnetic sheet 53 contains the third anisotropic magnetic particles 83 as one example of the third magnetic particles and a third binder 93, and, for example, the third anisotropic magnetic particles 83 are oriented in the surface direction in the third binder 93. Since the thermosetting component contained in the third binder 93 is in the B stage, the third magnetic sheet 53 is in the B stage. If the third magnetic sheet 53 is a laminate (laminated sheet), the presence ratios of the third anisotropic magnetic particles 83 in the respective sheets are the same or different, and are preferably the same. In addition, the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 can be the same as or different from the presence ratio of the first anisotropic magnetic particles 81 in the first magnetic sheet 51.

[0236] In the case where the presence ratio of the third anisotropic magnetic particles 83 is different from that of the first anisotropic magnetic particles 81, and the presence ratio of the first anisotropic magnetic particles 81 is 40 vol% or less, the presence ratio of the third anisotropic magnetic particles 83 is set to be higher than that of the first anisotropic magnetic particles 81. Specifically, the ratio of the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 to that of the first anisotropic magnetic particles 81 in the first magnetic sheet 51 (the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 / the presence ratio of the first anisotropic magnetic particles 81 in the first magnetic sheet 51) is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more, and, for example, 2.5 or less, preferably 2 or less. In this case, specifically, the presence ratio of the third anisotropic magnetic particles 83 in the third magnetic sheet 53 is, for example, 40 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, for example, 95 vol% or less, preferably 90 vol% or less.

[0237] If the above ratio and / or presence ratio of the third anisotropic magnetic particles 83 is within the above range, the presence of voids between the third magnetic sheet 53 and the first magnetic sheet 51 can be suppressed as much as possible, and as a result, the first anisotropic magnetic particles 81 and the third anisotropic magnetic particles 83 can be densely arranged in the peripheral region 4. Thus, an inductor 1 having excellent inductance can be obtained.

[0238] The thickness of the third magnetic sheet 53 (total thickness if it is a laminated sheet) is, for example, 0.5 times or more, preferably 1 times or more, and, for example, 5 times or less, preferably 3 times or less, of the radius R of the wiring 2.

[0239] Next, the second magnetic sheet 52 and the third magnetic sheet 53 are arranged in the press 42. Specifically, between the first plate 43 and the second plate 44, the first release sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 are arranged in this order toward the thickness direction side.

[0240] Further, as for the first release sheet 41 and / or the second release sheet 45, the first release sheet 41 and / or the second release sheet 45 removed in the above third process can be reused, or another first release sheet 41 and / or another second release sheet 45 can be prepared and arranged.

[0241] Further, in the hot pressing of the fourth process and the fifth process, the release gasket 46 used in the second process is not arranged in the press 42.

[0242] Next, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, and the second magnetic sheet 52 are heat-pressed by the flat-plate press 42. The heat-pressing conditions are the same as those in the second process.

[0243] The other side surface of the second magnetic sheet 52 follows the shape of the raised portion 25 of the first magnetic sheet 51 under the action of heat-pressing. However, the one side surface of the second magnetic sheet 52 maintains its flat shape.

[0244] That is, the second magnetic sheet 52 covers the thickness direction one side surface of the first magnetic sheet 51, which is the first one side surface of the first release sheet 41 and the optimal arc of the circumferential surface of the wiring 2 (the fourth process is performed).

[0245] In addition, the other side surface of the third magnetic sheet 53 maintains its flat shape under the action of heat-pressing.

[0246] On the other hand, the opposite portion 28 of the one side surface of the third magnetic sheet 53, which is opposite to the thickness direction other end edge E4 of the wiring 2, slightly moves (recedes, descends, sinks) to the thickness direction other side. That is, in the one side surface of the third magnetic sheet 53, the opposite portion 28 moves to the outside of the first direction thereof, and slightly sinks to the thickness direction one side with respect to the second flat portion 29 parallel to the one side surface of the first release sheet 41.

[0247] The other side surface of the first magnetic sheet 51 is in close contact with the second flat portion 29 of the one side surface of the third magnetic sheet 53, and the other side surface of the first magnetic sheet 51 slightly moves to the thickness direction one side with respect to the thickness direction other end edge E4 of the wiring 2.

[0248] That is, the third magnetic sheet 53 is arranged on the thickness direction other side of the first magnetic sheet 51 in such a manner as to cover the portion of the circumferential surface of the wiring 2 exposed from the thickness direction other side surface of the first magnetic sheet 51 (the arc surface including the thickness direction other end edge E4) (the fifth process is performed).

[0249] Thus, for the portion overlapping the wiring 2 when projected in the thickness direction, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, and the second magnetic sheet 52 are arranged in this order toward the thickness direction one side. In addition, for the portion not overlapping the wiring 2 when projected in the thickness direction, the third magnetic sheet 53, the first magnetic sheet 51, and the second magnetic sheet 52 are arranged in this order toward the thickness direction one side.

[0250] The sixth process is performed simultaneously with the fourth process and the fifth process by the above heat-pressing.

[0251] The heat-pressing conditions are selected in such a manner as to enable the thermosetting components C of the first adhesive 91, the second adhesive 92, and the third adhesive 93 to be phase-converted.

[0252] In this 6th process, the 1st binder 91 in the 1st magnetic sheet 51, the 2nd binder 92 in the 2nd magnetic sheet 52, and the 3rd binder 93 in the 3rd magnetic sheet 53 are simultaneously C-staged by the above-mentioned heat pressing.

[0253] Therefore, the binder 9 contains a cured product of the C-stage thermosetting component (C-stage substance).

[0254] Further, by the C-staging of the 1st magnetic sheet 51, the 2nd magnetic sheet 52, and the 3rd magnetic sheet 53, the interfaces of the 1st magnetic sheet 51 and the 2nd magnetic sheet 52 and the interfaces of the 1st magnetic sheet 51 and the 3rd magnetic sheet 53 disappear, respectively, and one magnetic layer 3 composed of the 1st magnetic sheet 51, the 2nd magnetic sheet 52, and the 3rd magnetic sheet 53 is formed (refer to Figure 1 A). However, in Figure 3 F, the above-mentioned interfaces are described in order to clearly show the arrangement of the 1st magnetic sheet 51, the 2nd magnetic sheet 52, and the 3rd magnetic sheet 53.

[0255] 3. Use

[0256] The inductor 1 is a component of an electronic device, that is, a component for manufacturing an electronic device, and does not contain an electronic element (chip, capacitor, etc.), a mounting substrate on which the electronic element is mounted, but is circulated as a single component, and is a device that can be utilized in industry.

[0257] The inductor 1 is mounted (assembled) on an electronic device or the like, for example. The electronic device includes a mounting substrate and an electronic element (chip, capacitor, etc.) mounted on the mounting substrate, but this case is not illustrated. Further, the inductor 1 is mounted on the mounting substrate by a connection member such as solder, and is electrically connected to other electronic devices, and functions as a passive element such as a coil.

[0258] Further, in this method, as shown in Figure 2 B, in the 2nd process, the 1st magnetic sheet 51 is arranged on the 1st release sheet 41 so as to cover the major arc of the wiring 2 on the thickness direction side of the 1st release sheet 41, and thus, in the portion of the 1st 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 inductance of the obtained inductor 1 is excellent.

[0259] Furthermore, in the second process, the first magnetic sheet 51 is disposed on one side of the first release sheet 41 in the thickness direction. Therefore, in the first magnetic sheet 51, the first anisotropic magnetic particles 81 are oriented along one side of the first release sheet 41 in the thickness direction. Thus, at the two circumferential edges of the region facing the side of the first release sheet 41 in the thickness direction and corresponding to the superior arc of the wiring 2, that is, in the second region 12, the orientation of the first anisotropic magnetic particles 81 along the circumferential direction of the wiring 2 can be suppressed. Therefore, the DC superposition characteristics of the inductor 1 are excellent.

[0260] Furthermore, the first magnetic sheet 51 covers the superior arc of the circumferential surface of the wiring 2. Therefore, at both ends of the superior arc in the circumferential direction, the orientation direction of the first anisotropic magnetic particles 81 can be changed from the circumferential direction of the wiring 2 to a direction along one side of the first release sheet 41, and the first anisotropic magnetic particles 81 can be densely arranged. As a result, an inductor 1 with excellent inductance can be manufactured.

[0261] And, as Figure 3 As shown in Figure F, in the fourth step, the second magnetic sheet 52 covers one side of the first magnetic sheet 51 in the thickness direction. Therefore, the anisotropic magnetic particles 8, including the first anisotropic magnetic particles 81 and the second anisotropic magnetic particles 82, in the peripheral region 4 of the wiring 2 can be densely arranged. Therefore, it is possible to manufacture an inductor 1 with better inductance.

[0262] Therefore, by using this manufacturing method, the anisotropic magnetic particles 8 in the surrounding region 4 can be densely arranged, thus enabling the fabrication of an inductor 1 with excellent inductance and excellent DC superposition characteristics.

[0263] Additionally, in this method, such as Figure 3 As shown in Figure F, a third magnetic sheet 53 is also disposed on the other side of the first magnetic sheet 51 in the thickness direction. Therefore, the anisotropic magnetic particles 8, including the first anisotropic magnetic particles 81, the second anisotropic magnetic particles, and the third anisotropic magnetic particles 83, can be densely arranged in the peripheral region 4 of the wiring 2. Therefore, it is possible to manufacture an inductor 1 with better inductance.

[0264] In particular, the third magnetic sheet 53 covers the portion of the circumferential surface exposed from the other side of the first magnetic sheet 51 in the thickness direction. Therefore, the third 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 first magnetic sheet 51. As a result, an inductor 1 with excellent inductance can be manufactured.

[0265] In addition, in the method, the fourth process and the fifth process are performed at the same time, and thus, compared with a method in which the fourth process and the fifth process are performed sequentially (see a modification example described later), the manufacturing time can be shortened. Thus, the inductor 1 can be efficiently manufactured.

[0266] In the sixth process of the method, the thermosetting component of the B-stage of the first adhesive 91 and the thermosetting component of the B-stage of the third adhesive 93 are simultaneously C-staged, and thus, compared with a method in which the thermosetting component of the B-stage of the first adhesive 91 and the thermosetting component of the B-stage of the third adhesive 93 are sequentially performed (see a modification example described later), the manufacturing time can be shortened. Thus, the inductor can be efficiently manufactured.

[0267] <Modification Example of the First Embodiment>

[0268] In the modification example, the same reference numerals are given to the same members and processes as those of the first embodiment, and detailed description thereof is omitted. In addition, the modification example can have the same effects as those of the first embodiment except that the effects are particularly described. Furthermore, the first embodiment and the modification example thereof can be appropriately combined.

[0269] In the first embodiment, the fourth process and the fifth process and the sixth process are performed at the same time. However, it can be that the fourth process and the fifth process are performed, and then the sixth process is performed.

[0270] In the first embodiment, the fourth process and the fifth process are performed at the same time. However, the fourth process and the fifth process can also be sequentially performed. Specifically, in the modification example, as shown in Figure 4 A to D Figure 6 H, the first process, the second process, the fourth process, the third process, the fifth process, and the sixth process are sequentially performed.

[0271] As shown in Figure 4 A, in the first process, the wiring 2 is disposed on the one side surface of the first release sheet 41 in the thickness direction.

[0272] As shown in Figure 4 B, next, in the second process, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 are sandwiched by the flat plate press 42, and then the wiring 2 and the first magnetic sheet 51 are heat-pressed by the flat plate press 42 with the first release sheet 41, the second release sheet 45, and the release gasket 46 interposed therebetween. Thus, the first magnetic sheet 51 is disposed on the one side surface of the first release sheet 41 in the thickness direction in a manner of covering the major arc of the circumferential surface of the wiring 2.

[0273] As shown in Figure 5 D, next, the fourth process is performed. Specifically, first, the first magnetic sheet 51 and the wiring 2 are released from the first release sheet 41 and the second release sheet 45. Figure 4The pressing of the press 42 shown in B is followed by, as shown in Figure 4 C, the second release sheet 45 and the release shim 46 are removed from the press 42 while maintaining the state in which the first release sheet 41, the wiring 2, and the first magnetic sheet 51 are arranged on the press 42.

[0274] In the fourth process, thereafter, the second magnetic sheet 52 and the second release sheet 45 are separately arranged on the thickness direction side of the first magnetic sheet 51.

[0275] As shown in Figure 5 D, the second magnetic sheet 52 is then heat-pressed using the press 42. Thereby, the second magnetic sheet 52 covers one side surface of the first magnetic sheet 51.

[0276] As shown in Figure 6 G, the third process is implemented. Specifically, first, the pressing of the press 42 shown in D is released, and the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 are removed from the press 42. Figure 5 D is released, and the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 are removed from the press 42.

[0277] In the third process, thereafter, as shown in Figure 5 E, the first release sheet 41 is peeled off from the other side surface of the first magnetic sheet 51 and the thickness direction other end edge E4 of the wiring 2.

[0278] As shown in Figure 5 F, the fifth process is then implemented.

[0279] Specifically, in the fifth process, the first release sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 are arranged on the press 42.

[0280] In the fifth process, as shown in Figure 6 G, the third magnetic sheet 53 is heat-pressed using the press 42. Thereby, the third magnetic sheet 53 is arranged on the other side surface of the first magnetic sheet 51 in B stage in a manner of covering the thickness direction other end edge E4 of the wiring 2. At this time, the thickness direction other end edge E4 of the wiring 2 is sunk into the opposing portion 28.

[0281] The sixth process is implemented after the fifth process or simultaneously with the fifth process. Specifically, the first magnetic sheet 51, the second magnetic sheet 52, and the third magnetic sheet 53 are C-staged, and the magnetic layer 3 in C stage is formed. Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 covering the wiring 2 is obtained.

[0282] As shown in Figure 6 H, thereafter, the inductor 1 is removed from the press 42.

[0283] Among the modification example and the first embodiment, the first embodiment is preferable. If the first embodiment, the fourth process and the fifth process are simultaneously performed, so that the manufacturing man-hours can be reduced, and the inductor 1 can be easily manufactured.

[0284] In the second process of the first embodiment, as shown in Figure 2 B, the second release sheet 45 is arranged on the flat press 42, but it can be that the hot press is performed without arranging the second release sheet 45.

[0285] In the second magnetic sheet 52, the second anisotropic magnetic particles 82 are oriented in the surface direction, but the second anisotropic magnetic particles 82 can not be oriented in the surface direction.

[0286] <Second Embodiment>

[0287] In the second embodiment, the same reference numerals are assigned to the same members and processes as those of the first embodiment and the modification example thereof, and detailed description thereof is omitted. In addition, the second embodiment can have the same effects as those of the first embodiment and the modification example thereof, except as specifically described. Furthermore, the first embodiment, the second embodiment, and the modification examples thereof can be appropriately combined.

[0288] In Figure 1 A ~ Figure 1 B of the first embodiment, when projected in the thickness direction, the cross portion 20 is arranged on the thickness direction one end edge E3 side of the wiring 2 in a manner that is spaced apart from the thickness direction other end edge E4 of the wiring 2, but for example, as shown in Figure 7 A ~ Figure 7 B, the cross portion 20 can overlap the thickness direction other end edge E4 of the wiring 2.

[0289] As shown in Figure 7 A ~ Figure 7 B, the fourth region 14 of the inductor 1 of the second embodiment is narrower than the fourth region 14 of the inductor 1 of the first embodiment. Specifically, the angle a2 of the central angle C2 of the fourth region 14 is less than 15°, and further more than 0°.

[0290] Next, the manufacturing method of the inductor 1 will be described with reference to Figure 8 A ~ Figure 9 F.

[0291] The manufacturing method of the inductor 1 includes the first process to the sixth process. In the manufacturing method of the inductor 1, the first process, the second process, and the third process are sequentially performed, and then the fourth process and the fifth process are simultaneously performed. In addition, the sixth process is performed in stages, specifically, at the time of the hot press in the second process, and at the time of the hot press in the fourth process and the fifth process.

[0292] (First process)

[0293] As shown in Figure 8 A, in the first process, the wiring 2 is arranged on the thickness direction one side surface of the first release sheet 41.

[0294] (Second process and part of sixth process)

[0295] As shown in Figure 8 B, then, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 are sequentially sandwiched by the flat press 42.

[0296] Then, the first magnetic sheet 51 is heat-pressed by the flat press 42. Thereby, the first magnetic sheet 51 is arranged on the thickness direction one side surface of the first release sheet 41 in a manner of covering the major arc of the circumferential surface of the wiring 2.

[0297] After the second process or simultaneously with the second process, the first magnetic sheet 51 is heated by the heat source of the flat press 42 to C-stage the first magnetic sheet 51 (part of the sixth process is implemented).

[0298] (Third process)

[0299] In the third process, first, the pressing of the flat press 42 shown in Figure 8 B is released, and then, as shown in Figure 8 C, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 are taken out from the flat press 42.

[0300] Then, the first release sheet 41 is peeled off from the other side surface of the first magnetic sheet 51 and the thickness direction other end edge E4 of the wiring 2.

[0301] In addition, the second release sheet 45 and the release gasket 46 are peeled off from the one side surface of the first magnetic sheet 51.

[0302] (Fourth and fifth processes, and remaining part of sixth process)

[0303] As shown in Figure 9 E, the fourth and fifth processes are simultaneously implemented.

[0304] As shown in Figure 9 D, in the fourth and fifth processes, first, the first release sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 are arranged in the flat press 42. Further, both the second magnetic sheet 52 and the third magnetic sheet 53 are B-stage.

[0305] As shown in Figure 9The second magnetic sheet 52 and the third magnetic sheet 53 are then pressed by the flat press 42, as shown in FIG. 8.

[0306] As a result, the second magnetic sheet 52 covers the thickness direction side surface of the first magnetic sheet 51.

[0307] The third magnetic sheet 53 is arranged on the other thickness direction side surface of the first magnetic sheet 51 so as to cover the other end edge E4 of the wiring 2. At this time, movement of the other thickness direction side surface of the first magnetic sheet 51, which is relatively hard at the C stage, is suppressed, and in addition, sinking of the other end edge E4 of the wiring 2 toward the opposing portion 28 of the third magnetic sheet 53 is suppressed. That is, the one side surface of the third magnetic sheet 53 can be maintained flat.

[0308] The second magnetic sheet 52 and the third magnetic sheet 53 are then heated by the heat source of the flat press 42, and the second magnetic sheet 52 and the third magnetic sheet 53 are C-staged (the remaining part of the sixth step is performed).

[0309] As a result, the inductor 1 including the wiring 2 and the magnetic layer 3 is obtained.

[0310] As shown in FIG. 8, the inductor 1 is removed from the flat press 42. Figure 9

[0311] Among the first embodiment and the second embodiment, the first embodiment is preferable. If the first embodiment is adopted, the B-stage thermosetting components of the first adhesive 91 and the B-stage thermosetting components of the third adhesive 93 are simultaneously C-staged in the sixth step, and therefore, compared with the second embodiment in which the B-stage thermosetting components of the first adhesive 91 and the B-stage thermosetting components of the third adhesive 93 are sequentially subjected to C-staging, the manufacturing time can be shortened. Therefore, the inductor 1 can be easily manufactured.

[0312] <Modification of the Second Embodiment>

[0313] In the modification, the same reference numerals are assigned to the same components as those of the second embodiment, and detailed description thereof is omitted. In addition, the modification can have the same effects as those of the second embodiment, except as specifically described. Furthermore, the second embodiment and the modification thereof can be appropriately combined.

[0314] In the second embodiment, the fourth step and the fifth step and the remaining part of the sixth step are simultaneously performed. However, the fourth step and the fifth step can be performed, and then the remaining part of the sixth step can be performed.

[0315] In the second embodiment, the fourth step and the fifth step are simultaneously performed. However, the fourth step and the fifth step can be sequentially performed.

[0316] ​In this modification, as shown in Figure 10 A Figure 12 The first step, the second step, the fourth step, the third step, and the fifth step are sequentially performed as shown in

[0317] As shown in Figure 10 A, in the first step, the wiring 2 is disposed on the thickness direction one side surface of the first release sheet 41.

[0318] As shown in Figure 10 B, then, the second step is performed, and the first magnetic sheet 51C is staged. That is, a part of the sixth step is performed. Specifically, using the flat press 42, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 are sandwiched in this order, and then the wiring 2 and the first magnetic sheet 51 are heat-pressed by the flat press 42 through the first release sheet 41, the second release sheet 45, and the release gasket 46. In addition, the first magnetic sheet 51C is staged by the heat source of the flat press 42 (a part of the sixth step is performed).

[0319] As shown in Figure 11 D, then, the fourth step is performed. Specifically, first, the pressing of the flat press 42 shown in Figure 10 B is released, and then, as shown in Figure 10 C, the second release sheet 45 and the release gasket 46 are removed from the flat press 42 while maintaining the state in which the first release sheet 41, the wiring 2, and the first magnetic sheet 51 are disposed on the flat press 42.

[0320] In the fourth step, thereafter, the second magnetic sheet 52 and the second release sheet 45 are separately disposed on the thickness direction one side of the first magnetic sheet 51.

[0321] As shown in Figure 11 D, then, the second magnetic sheet 52 is heat-pressed using the flat press 42. Thereby, the second magnetic sheet 52 covers one side surface of the first magnetic sheet 51.

[0322] As shown in Figure 11 F, then, the third step is performed.

[0323] In the third step, specifically, first, the pressing of the flat press 42 shown in Figure 11 D is released, and the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 are removed from the flat press 42.

[0324] In the third step, then, as shown in Figure 11 E, the first release sheet 41 is peeled off from the other side surface of the first magnetic sheet 51 and the thickness direction other end edge E4 of the wiring 2.

[0325] As Figure 12 G shows, then, the 5th process is implemented.

[0326] As Figure 11 F shows, in the 5th process, first, specifically, the 1st release sheet 41, the 3rd magnetic sheet 53, the wiring 2, the 1st magnetic sheet 51, the 2nd magnetic sheet 52, and the 2nd release sheet 45 are arranged on the flat press 42.

[0327] In the 5th process, as Figure 12 G shows, the 3rd magnetic sheet 53 is heat-pressed by the flat press 42. Thereby, the 3rd magnetic sheet 53 is arranged on the other side surface of the 1st magnetic sheet 51 in the C stage in a manner of covering the other end edge E4 in the thickness direction of the wiring 2.

[0328] After the 5th process, the remaining part of the 6th process is implemented, or the remaining part of the 6th process is implemented simultaneously with the 5th process. Specifically, the 2nd magnetic sheet 52 and the 3rd magnetic sheet 53 are C-staged by the heat source of the flat press 42, and the magnetic layer 3 composed of the 3rd magnetic sheet 53, the 1st magnetic sheet 51, and the 2nd magnetic sheet 52 is formed. Thereby, the inductor 1 including the wiring 2 and the magnetic layer 3 covering the wiring 2 is obtained.

[0329] As Figure 12 H shows, after that, the inductor 1 is taken out from the flat press 42.

[0330] In addition, in the above-described modification example, the 1st magnetic sheet 51 is C-staged at the same time as the 2nd process in which the arrangement of the 1st magnetic sheet 51 with respect to the wiring 2 shown in B is performed, but the timing at which the 1st magnetic sheet 51 is C-staged is not particularly limited as long as it is before the 5th process (refer to Figure 10 G) in which the 3rd magnetic sheet 53 is arranged on the other side surface of the 1st magnetic sheet 51, and for example, it can be implemented at the same time as the 4th process in which the 2nd magnetic sheet 52 is arranged shown in D. Figure 12 Figure 11

[0331] In addition, the 1st magnetic sheet 51 and the 2nd magnetic sheet 52 can be C-staged at the same time. The 2nd magnetic sheet 52 is arranged on the one side surface of the 1st magnetic sheet 51 in the B stage, and after that, the 1st magnetic sheet 51 and the 2nd magnetic sheet 52 are C-staged at the same time.

[0332] In addition, it can be that the 2nd magnetic sheet 52 is C-staged, after that, the 3rd magnetic sheet 53 is arranged on the other side surface of the 1st magnetic sheet 51, and then, the 3rd magnetic sheet 53 is C-staged.

[0333] ​​Alternatively, the third magnetic sheet 53 can be disposed on the other side of the first magnetic sheet 51, and then the second magnetic sheet 52 can be disposed on one side of the first magnetic sheet 51. In this case, the third magnetic sheet 53 and the second magnetic sheet 52 can be C-staged simultaneously. Alternatively, the third magnetic sheet 53 can be C-staged first, and then the second magnetic sheet 52 can be C-staged.

[0334] In addition, such as Figure 13 As shown in A, in the first process, the wiring 2 may not be disposed on the first release sheet 41, but rather disposed on one side of the thickness direction of the third magnetic sheet 53 (an example of a substrate) in stage C.

[0335] Specifically, firstly, a third magnetic sheet 53 of stage C is fabricated and disposed on one side of the first release sheet 41 in the thickness direction. The third adhesive 93 in the third magnetic sheet 53 contains a cured product of the thermosetting component of stage C.

[0336] Next, the first release sheet 41, the third magnetic sheet 53 of stage C, the wiring 2, the first magnetic sheet 51, the second release sheet 45 and the release pad 46 are sandwiched in the middle using a flat plate press 42.

[0337] like Figure 13 As shown in B, the second step is carried out. In this second step, the first demolding sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, the second demolding sheet 45, and the demolding pad 46 are sandwiched in the middle in this order using a flatbed press 42.

[0338] Next, the third magnetic sheet 53, the wiring 2, and the first magnetic sheet 51 are hot-pressed using a flatbed press 42 with the first release plate 41, the second release plate 45, and the release pad 46 in between. As a result, the first magnetic sheet 51 is positioned on one side of the third magnetic sheet 53 in the thickness direction of stage C in a manner that covers the circumferential surface of the wiring 2 with an arc.

[0339] Next, in the fourth step, firstly, release... Figure 13 The pressure is applied by the flatbed press 42 shown in Figure B, and then, as... Figure 13 As shown in C, while maintaining the first demolding piece 41, the third magnetic piece 53, the wiring 2, and the first magnetic piece 51 in the flatbed press 42, the second demolding piece 45 and the demolding pad 46 are removed from the flatbed press 42.

[0340] Next, in the fourth step, the second magnetic sheet 52 and the second release sheet 45 are separately positioned on one side of the thickness direction of the first magnetic sheet 51. The first release sheet 41, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, the second magnetic sheet 52 and the second release sheet 45 are sandwiched in the middle using a flatbed press 42.

[0341] likeFigure 14 As shown in D, the second magnetic sheet 52 is then pressed using a flatbed press 42.

[0342] Then, the second magnetic sheet 52 and the first magnetic sheet 51C are stepped. Thus, a magnetic layer 3 composed of the third magnetic sheet 53, the first magnetic sheet 51 and the second magnetic sheet 52 is formed.

[0343] like Figure 14 As shown in E, inductor 1 is then obtained.

[0344] In the above-described variation, the first magnetic sheet 51 and the second magnetic sheet 52 are simultaneously C-staged. However, for example, it is also possible to C-stage the first magnetic sheet 51 first and then C-stage the second magnetic sheet 52.

[0345] <Other variations>

[0346] In these other modifications, the same reference numerals are used for components and processes identical to those in the first and second embodiments, and detailed descriptions are omitted. Furthermore, unless specifically stated otherwise, the modifications can achieve the same effects as the first and second embodiments. Moreover, the first and second embodiments and their modifications can be appropriately combined.

[0347] like Figure 15 As shown in A, in the first process, the wiring 2 can be disposed on one side of the first release sheet 41 by means of the pressure-sensitive adhesive layer 61.

[0348] The pressure-sensitive adhesive layer 61 extends along the second direction and is in the form of a thin-walled sheet. The length of the pressure-sensitive adhesive layer 61 in the first direction is, for example, less than 0.5 and less than 0.25 of the radius R of the wiring 2.

[0349] like Figure 15 As shown in B, in the second process, the first magnetic sheet 51 covers the circumferential arc of the wiring 2 in such a way that it is filled to both sides of the pressure-sensitive adhesive layer 61 in the first direction.

[0350] like Figure 15 As shown in C, in inductor 1, a pressure-sensitive adhesive layer 61 may remain between the third 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 second process, which is not shown in the figure.

[0351] In addition, such as Figure 16As shown in A, in the first step, the wiring 2 can be disposed on one side of the first release sheet 41 with the gap 62 interposed. For example, by interposing a spacer (not shown) between the both end portions of the wiring 2 in the second direction and the first release sheet 41, the wiring 2 is tensioned to both sides in the second direction and the gap 62 that separates the other end edge E4 of the wiring 2 in the thickness direction and the one side surface of the first release sheet 41 is ensured.

[0352] As shown in A, in the first step, the wiring 2 can be disposed on one side of the first release sheet 41 with the gap 62 interposed. For example, by interposing a spacer (not shown) between the both end portions of the wiring 2 in the second direction and the first release sheet 41, the wiring 2 is tensioned to both sides in the second direction and the gap 62 that separates the other end edge E4 of the wiring 2 in the thickness direction and the one side surface of the first release sheet 41 is ensured. Figure 16 As shown in B, under the heat press in the second step, the first magnetic sheet 51 is filled into the gap 62, so that the first magnetic sheet 51 covers the entire circumferential surface of the wiring 2.

[0353] Subsequently, as shown in C, the one side surface of the first magnetic sheet 51 is covered with the second magnetic sheet 52. Figure 16

[0354] Subsequently, for example, heating and pressurization are simultaneously performed, and the first binder 91 of the first magnetic sheet 51 and the second binder 92 of the second magnetic sheet 52 are phase-converted.

[0355] Thus, the magnetic layer 3 composed of the first magnetic sheet 51 and the second magnetic sheet 52 is formed.

[0356] In this method, the wiring 2 can be covered with the magnetic layer 3 without disposing the third magnetic sheet 53 in the thickness direction of the other end edge E4. Therefore, the working hours can be reduced.

[0357] Further, as shown by the imaginary line of C, as needed, the third magnetic sheet 53 can also be disposed on the other side surface of the first magnetic sheet 51. Figure 16

[0358] Further, as shown by the imaginary line of C, as needed, the third magnetic sheet 53 can also be disposed on the other side surface of the first magnetic sheet 51. Figure 2 As shown in A, in the first step, the wiring 2 can be disposed on one side of the first release sheet 41 with the gap 62 interposed. For example, by interposing a spacer (not shown) between the both end portions of the wiring 2 in the second direction and the first release sheet 41, the wiring 2 is tensioned to both sides in the second direction and the gap 62 that separates the other end edge E4 of the wiring 2 in the thickness direction and the one side surface of the first release sheet 41 is ensured. Figure 16 As shown in B, under the heat press in the second step, the first magnetic sheet 51 is filled into the gap 62, so that the first magnetic sheet 51 covers the entire circumferential surface of the wiring 2.

[0359] The first anisotropic magnetic particles 81, but for example, the first magnetic particles can not have anisotropy, and for example, have isotropy. As the shape of the first isotropic magnetic particles, for example, a substantially spherical shape is given. As the first isotropic magnetic particles of the substantially spherical shape, for example, a substantially spherical iron particle or the like is given. The average particle diameter of the first isotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and for example, 200 μm or less, preferably 150 μm or less.​​

[0360] In addition, as in the first embodiment Figure 2 A, the modification of the first embodiment Figure 4 A, the second embodiment Figure 8 A, and the modification of the second embodiment Figure 10 A and Figure 13 As shown in A, the first anisotropic magnetic particles 81 are oriented in the surface direction in the first magnetic sheet 51, but are not limited thereto, and the first anisotropic magnetic particles 81 can not be oriented in the surface direction in the first magnetic sheet 51.

[0361] In the first embodiment and the second embodiment, the third anisotropic magnetic particles 83 are given as an example of the third magnetic particles, but for example, the third magnetic particles can not have anisotropy, and for example, can have isotropy. As a shape of the third isotropic magnetic particles, for example, a substantially spherical shape is given. As the third isotropic magnetic particles of the substantially spherical shape, for example, a substantially spherical shape iron particle or the like is given. The average particle diameter of the third isotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and for example, 200 μm or less, preferably 150 μm or less.

[0362] In addition, as in the first embodiment Figure 3 D, the modification of the first embodiment Figure 5 F, the second embodiment Figure 9 D, the modification of the second embodiment Figure 11 F and Figure 13 As shown in C, the third anisotropic magnetic particles 83 are oriented in the surface direction in the third magnetic sheet 53, but are not limited thereto, and the third anisotropic magnetic particles 83 can not be oriented in the surface direction in the third magnetic sheet 53.

[0363] As Figure 1 B and Figure 7 As shown in B and D, in the first embodiment and the second embodiment, the anisotropic magnetic particles 8 are oriented in the circumferential direction of the wiring 2 at least in the first region 11, but are not limited thereto, and the anisotropic magnetic particles 8 can not be oriented in the circumferential direction of the wiring 2.

[0364] In addition, the proportion (filling rate) of the magnetic particles (the first magnetic particles, the second anisotropic magnetic particles 82, and the third magnetic particles) of the magnetic layer 3 is not limited to the above description, and for example, the proportion (filling rate) can be higher or lower as it is farther from the wiring 2. In manufacturing the inductor 1 in which the proportion of the magnetic particles of the magnetic layer 3 is higher as it is farther from the wiring 2, for example, the proportion of the second anisotropic magnetic particles 82 in the second magnetic sheet 52 is set to be higher than the proportion of the magnetic particles in the first magnetic sheet 51.

[0365] In addition, in a modification in which the filling rate of the magnetic particles of the magnetic layer 3 is made higher or lower as it moves away from the wiring 2 as described above, the magnetic layer 3 can also be multilayered. In this case, it can be that the wiring 2 is pressed using one of the plurality of magnetic pieces for covering the outer circumferential surface of the wiring 2, and then the remaining magnetic pieces are pressed against them, or it can also be that the plurality of magnetic pieces press the wiring 2 at one time (all at once). For example, the wiring 2 can be pressed at one time using the first magnetic piece 51, the second magnetic piece 52, and the third magnetic piece 53 of one embodiment. Specifically, the first process shown in A, the second process shown in B, and the third process shown in C can be implemented at the same time. Figure 13 the first process shown in A, Figure 13 the second process shown in B, and Figure 13 the fourth process shown in C.

[0366] Embodiment

[0367] Embodiments and comparative examples are shown below to further specifically describe the present application. Furthermore, the present application is not limited to any of the embodiments and comparative examples. In addition, in the following description, the specific numerical values of the compounding ratio (content ratio), physical property values, parameters, and the like used therein can replace the upper limit values (numerical values defined in the manner of "or less," "less than") or lower limit values (numerical values defined in the manner of "or more," "more than") of the corresponding description of the compounding ratio (content ratio), physical property values, parameters, and the like described in the "DETAILED DESCRIPTION" above.

[0368] Embodiment 1

[0369] Manufacturing Example of Inductor Based on First Embodiment

[0370] In Embodiment 1, an inductor 1 was manufactured based on the first embodiment. Specifically, as shown in A to 3F, the first process, the second process, and the third process were sequentially implemented, and then the fourth process, the fifth process, and the sixth process were implemented at the same time. Figure 2

[0371] (First Process)

[0372] The wiring 2 and the first release sheet 41 were prepared.

[0373] Specifically, the wiring 2 having a radius R of 110 μm was prepared. The radius R1 of the lead wire 6 was 100 μm, and the thickness R2 of the insulating layer 7 was 10 μm.

[0374] The first release sheet 41 made of PET having a thickness of 50 μm was prepared separately.

[0375] As shown in A to 3F, the first process, the second process, and the third process were sequentially implemented, and then the fourth process, the fifth process, and the sixth process were implemented at the same time. Figure 2 ​As shown in A, the wiring 2 is then positioned on one side of the first release sheet 41 in the thickness direction.

[0376] (Step 2)

[0377] The first magnetic sheet 51, the second release sheet 45, and the release pad 46 were prepared.

[0378] Specifically, a first magnetic sheet 51, serving as a stage B sheet, was prepared, consisting of an inner sheet 54 comprising 50% by volume of anisotropic magnetic particles 8 and an outer sheet 55 comprising 60% by volume of anisotropic magnetic particles 8. The formulations of the inner sheet 54 and the outer sheet 55 are as described in Table 1.

[0379] In addition, as the second release sheet 45, a release film made of TPX (registered trademark) (manufactured by Mitsui Chemicals East Cellulose Co., Ltd.) is prepared.

[0380] In addition, a release pad 46 was prepared, consisting of two layers of release film OT-A110 (manufactured by Sekisui Chemicals Co., Ltd.).

[0381] The release shim 46 has a thickness (total thickness of the release film OT-A110) of 110 μm, comprising a first layer 47 with a thickness of 15 μm, a second layer 48 with a thickness of 80 μm, and a third layer 49 with a thickness of 15 μm. The tensile storage modulus E' of the first layer 47 and the third layer 49 at 110 °C is 190 MPa, and the materials of the first layer 47 and the third layer 49 contain polybutylene terephthalate as a main component. The tensile storage modulus E' of the second layer 48 at 110 °C is 5.6 MPa, and the material of the second layer 48 contains ethylene-methyl methacrylate copolymer as a main component.

[0382] Next, using a flatbed press 42, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release pad 46 are sandwiched in the middle in this order.

[0383] like Figure 2 As shown in B, the wiring 2 and the first magnetic sheet 51 were then hot-pressed using a flatbed press 42 under the pressure conditions of 2 MPa, 110°C and 60 seconds.

[0384] SEM images of the cross-sections of wiring 2 and the first magnetic sheet 51 after the second process are shown below. Figure 17 A.

[0385] (Step 3)

[0386] In the third process, firstly, release Figure 2 The pressure is applied by the flatbed press 42 shown in Figure B, and then, as... Figure 2As shown in FIG. 42, the first release sheet 41, the wiring 2, the first magnetic sheet 51, the second release sheet 45, and the release gasket 46 were taken out from the flat press 42. Next, the first release sheet 41 was peeled off from the other side surface of the first magnetic sheet 51 and the other end edge E4 of the wiring 2 in the thickness direction. In addition, the second release sheet 45 and the release gasket 46 were peeled off from the one side surface of the first magnetic sheet 51.

[0387] (4th process, 5th process, and 6th process)

[0388] The second magnetic sheet 52 and the third magnetic sheet 53 were prepared.

[0389] Specifically, five sheets of the same formula (60 vol% of the anisotropic magnetic particles 8) as the outer sheet 55 in the first magnetic sheet 51 were prepared, and the second magnetic sheet 52 composed of the laminated sheets was prepared as a B-stage sheet.

[0390] In addition, four sheets of the same formula (60 vol% of the anisotropic magnetic particles 8) as the outer sheet 55 in the first magnetic sheet 51 and one sheet of the same formula (50 vol% of the anisotropic magnetic particles 8) as the inner sheet 54 in the first magnetic sheet 51 were laminated and prepared, and the third magnetic sheet 53 composed of the laminated sheets was prepared as a B-stage sheet.

[0391] As shown in FIG. 43, next, the first release sheet 41, the wiring 2, the third magnetic sheet 53, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 (PET film) were sequentially arranged toward the one side in the thickness direction between the first plate 43 and the second plate 44. Figure 3 D. As shown in FIG. 44, next, the first release sheet 41, the wiring 2, the third magnetic sheet 53, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 (PET film) were sequentially arranged toward the one side in the thickness direction between the first plate 43 and the second plate 44.

[0392] As shown in FIG. 45, next, the first release sheet 41, the wiring 2, the third magnetic sheet 53, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 (PET film) were sequentially arranged toward the one side in the thickness direction between the first plate 43 and the second plate 44. Figure 3 E. As shown in FIG. 46, next, the third magnetic sheet 53, the wiring 2, the first magnetic sheet 51, and the second magnetic sheet 52 were heat-pressed by the flat press 42 under a pressing condition of 2 MPa, 170°C, and 900 seconds. Thus, the thermosetting components in the first binder 91, the second binder 92, and the third binder 93 were C-staged.

[0393] Thus, the circumference of the wiring 2 was covered with the magnetic layer 3 composed of the C-staged first magnetic sheet 51, the second magnetic sheet 52, and the third magnetic sheet 53, and the inductor 1 was manufactured. Figure 1 A ~B. As shown in FIG. 47, the inductor 1 was manufactured. Figure 1 As shown in FIG. 48, next, the first release sheet 41, the wiring 2, the third magnetic sheet 53, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 (PET film) were sequentially arranged toward the one side in the thickness direction between the first plate 43 and the second plate 44.

[0394] Figure 3 F. As shown in FIG. 49, next, the first release sheet 41, the wiring 2, the third magnetic sheet 53, the first magnetic sheet 51, the second magnetic sheet 52, and the second release sheet 45 (PET film) were sequentially arranged toward the one side in the thickness direction between the first plate 43 and the second plate 44.

[0395] A cross-sectional SEM photograph of the inductor 1 is shown in Figure 17 B.

[0396] Example 2

[0397] Example of manufacturing the inductor based on the modified example of the first embodiment

[0398] In Example 2, the inductor 1 was manufactured based on the modified example of the first embodiment shown in Figs. 2A to 2D and Figs. 3A to 3D. Specifically, the first process, the second process, the fourth process, the third process, the fifth process, and the sixth process were sequentially performed, and otherwise, the processes were performed similarly to Example 1. Figure 4 A ~ Figure 6 The inductor 1 was manufactured by sequentially laminating the first magnetic sheet 51, the first adhesive layer, the first release sheet 41, the wiring 2, the second adhesive layer, the second magnetic sheet 52, the second release sheet 45, and the release gasket 46 on the first plate 43, and then pressing the laminated body with the second plate 44.

[0399] The inductor 1 was manufactured by sequentially laminating the first magnetic sheet 51, the first adhesive layer, the first release sheet 41, the wiring 2, the second adhesive layer, the second magnetic sheet 52, the second release sheet 45, and the release gasket 46 on the first plate 43, and then pressing the laminated body with the second plate 44. Figure 7 A ~ Figure 7 B. The SEM photograph of the cross section of the inductor 1 is shown in Fig. 4B. Figure 18

[0400] Examples 3 to 5

[0401] The inductor 1 was manufactured by changing the formulation of the first magnetic sheet 51 according to Table 1, and otherwise, the processes were performed similarly to Example 1.

[0402] Comparative Example 1

[0403] On the thickness direction side of the first plate 43, the first release sheet 41 composed of PET having a thickness of 50 μm, the third magnetic sheet 53 of the C-stage, the first adhesive layer of the B-stage, the wiring 2 identical to that of Example 1, the second adhesive layer of the B-stage, the second magnetic sheet 52 of the C-stage, the second release sheet 45 composed of TPX, and the release gasket 46 composed of two sheets of release film OT-A110 (manufactured by Shikoku Chemicals Corporation) were sequentially arranged, and the laminated body composed of them was sandwiched with the first plate 43 and the second plate 44.

[0404] Further, neither the first adhesive layer nor the second adhesive layer contained the anisotropic magnetic particles 8, and was a B-stage sheet composed of a thermosetting resin. The thickness of the first adhesive layer and the second adhesive layer was 2 μm, respectively.

[0405] The formulation of the second magnetic sheet 52 of the C-stage and the third magnetic sheet 53 of the C-stage was completely cured as described in Table 1.

[0406] Next, the inductor 1 was manufactured by hot-pressing the above laminated body using the flat press machine 42 under the pressing conditions of a pressing pressure of 2 MPa, 170°C, and 900 seconds.

[0407] The SEM photograph of the cross section of the inductor 1 of Comparative Example 1 is shown in Fig. 5B. Figure 19

[0408] The SEM photograph of the cross section of the inductor 1 of Comparative Example 1 is shown in Fig. 5B. Figure 19 ​​As can be seen, a void is formed between the second arc surface 24 of the wiring 2 and the first magnetic sheet 51 (magnetic layer 3) and between the first direction both end edges E2, E3 of the wiring 2 and the first magnetic sheet 51 (magnetic layer 3).

[0409] Comparative Example 2

[0410] A first release sheet 41 composed of PET having a thickness of 50 μm, a third magnetic sheet 53 of C-stage, a first pressure-sensitive adhesive layer, the wiring 2 identical to that of Example 1, a second pressure-sensitive adhesive layer, a second magnetic sheet 52 of C-stage, a second release sheet 45 composed of TPX, and a release gasket 46 composed of two release films OT-A110 (manufactured by Shikoku Chemicals Corporation) laminated were arranged in this order in the thickness direction of the first plate 43, and the laminate composed of them was sandwiched by the first plate 43 and the second plate 44.

[0411] Further, neither the first pressure-sensitive adhesive layer nor the second pressure-sensitive adhesive layer contains the anisotropic magnetic particles 8, but is composed of a pressure-sensitive adhesive tape (adhesive tape) composed of an acrylic pressure-sensitive adhesive (adhesive). The thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is 5 μm, respectively.

[0412] The formulation of the second magnetic sheet 52 of C-stage and the third magnetic sheet 53 of C-stage is as described in Table 1, and both are completely cured cured bodies.

[0413] Next, using the flat press 42, the laminate was heat-pressed by the flat press 42 under a pressing pressure of 2 MPa, 110°C, and 60 seconds, and the inductor 1 was produced.

[0414] A void is formed between the second arc surface 24 of the wiring 2 and the first magnetic sheet 51 (magnetic layer 3) and between the first direction both end edges E2, E3 of the wiring 2 and the first magnetic sheet 51 (magnetic layer 3).

[0415] <Fill Factor>

[0416] The fill factor 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 was recognized as the anisotropic magnetic particles 8, and black was recognized as the binder 9, and then the fill factor (existence ratio) of the anisotropic magnetic particles 8 was calculated from the proportion of the cross-sectional area of white in the first region 11.

[0417] The results are shown in Table 1.

[0418] <Inductance>

[0419] The ends of the transmission direction of the conductor 6 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: 4294A) to obtain the inductance. The inductance of the inductor 1 was evaluated based on the following criteria.

[0420] ◎: inductance is 110 H or more

[0421] O: inductance is 90 H or more and less than 110 H

[0422] Δ: inductance is 60 H or more and less than 90 H

[0423] X: inductance is less than 60 H

[0424] The results are shown in Table 1.

[0425] [Table 1]

[0426]

[0427] Furthermore, the above-described application is provided as an example of an embodiment of the present application, but this is merely an example and is not to be construed limitatively. Variations of the present application that are apparent to those skilled in the art are included in the foregoing claims.

[0428] Industrial Applicability

[0429] An inductor is mounted, for example, on an electronic device or the like.

[0430] Explanation of Reference Numerals

[0431] 1: inductor; 2: wiring; 3: magnetic layer; 4: peripheral region; 6: conductor; 7: insulating layer; 8: anisotropic magnetic particle; 9: binder; 41: first release sheet; 51: first magnetic sheet; 52: second magnetic sheet; 53: third magnetic sheet; 81: first anisotropic magnetic particle (one example of first magnetic particle); 82: second anisotropic magnetic particle (one example of second magnetic particle); 83: third anisotropic magnetic particle (one example of third magnetic particle); 91: first binder; 92: second binder; 93: third binder.

Claims

1. A method of manufacturing an inductor, characterized by comprising: a first step in which a wiring having a shape in cross section that is substantially circular and including a conductor and an insulating layer covering the conductor is disposed on one side in a thickness direction of a substrate; a second step in which a first magnetic sheet containing first magnetic particles and a first binder that disperses the first magnetic particles is disposed on the one side in the thickness direction of the substrate in a manner so as to cover an area of more than 180° in a circumferential surface of the wiring in cross section; and a fourth step in which a second magnetic sheet containing second magnetic particles that include second anisotropic magnetic particles oriented in a surface direction and a second binder that disperses the second magnetic particles covers a side of the first magnetic sheet in the thickness direction away from the one side of the substrate that covers the area of the circumferential surface.

2. The method of manufacturing an inductor according to claim 1, characterized in that: the first magnetic particles include first anisotropic magnetic particles oriented in the surface direction in the first magnetic sheet.

3. The method of manufacturing an inductor according to claim 1, characterized in that: the substrate is a release sheet, the method of manufacturing an inductor further comprises: a third step in which the substrate is removed; and a fifth step in which a third magnetic sheet containing third magnetic particles and a third binder that disperses the third magnetic particles is disposed on the other side in the thickness direction of the first magnetic sheet in a manner so as to cover a portion of the circumferential surface exposed from the other side in the thickness direction of the first magnetic sheet.

4. The method of manufacturing an inductor according to claim 3, characterized in that: the third magnetic particles include third anisotropic magnetic particles oriented in the surface direction in the third magnetic sheet.

5. The method of manufacturing an inductor according to claim 3, characterized in that: the first step, the second step, and the third step are sequentially performed, and then the fourth step and the fifth step are simultaneously performed.

6. The method of manufacturing an inductor according to claim 3, characterized in that: the first binder in the second step and the third binder in the fifth step each contain a B-stage thermosetting component, and the method of manufacturing an inductor further comprises a sixth step in which the B-stage thermosetting component of the first binder and the B-stage thermosetting component of the third binder are simultaneously C-staged.

7. The method of manufacturing an inductor according to claim 1, characterized in that: the substrate is a third magnetic sheet containing third magnetic particles and a third binder that disperses the third magnetic particles, the third binder contains a cured product of a thermosetting component.

8. The method of manufacturing an inductor according to claim 7, characterized in that: the third magnetic particles include third anisotropic magnetic particles oriented in the surface direction in the third magnetic sheet. ​

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