Inductor and method of manufacturing the same

Abstract

A method for manufacturing an inductor (1) includes a first step of preparing a wiring (2), a second step of forming a magnetic layer (3) from a magnetic composition containing magnetic particles, the magnetic layer (3) being formed so as to cover a second outer circumferential surface (13) of a middle portion (10) of the wiring (2) and so that a first end portion (8) and a second end portion (9) of the wiring (2) are exposed from the magnetic layer (3) by a range of 2 mm or more and less than 100 mm, and a third step of removing the first end portion (8) and the second end portion (9) of the wiring (2).

Description

TECHNICAL FIELD

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

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

[0003] As such an inductor, for example, an inductor having an internal conductor of copper or the like, and a substrate main body portion in which the internal conductor is buried and which is composed of a magnetic material is proposed (for example, refer to Patent Document 1). In the inductor of Patent Document 1, both end surfaces of the internal conductor are formed flush with both end surfaces of the substrate main body portion.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-144526 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the inductor, before being mounted on the electronic device, it is necessary to bring a probe (inspection terminal) or the like into contact with both end surfaces of the internal conductor, and to perform evaluation of magnetic characteristics such as inductance of the inductor, and / or inspection of whether or not the internal conductor is in conduction.

[0009] However, in the inductor of Patent Document 1, since at least one end surface of the internal conductor and one end surface of the substrate main body portion are formed flush with each other, it is difficult to bring the probe directly into contact with the one end surface of the internal conductor, and thus there is a problem that the above-mentioned evaluation and inspection cannot be performed.

[0010] Further, even if it is possible to bring the probe into contact with the one end surface of the internal conductor, electrical connection of the probe to the internal conductor is likely to be poor, and thus there is a problem that the above-mentioned evaluation and inspection are unreliable.

[0011] On the other hand, there is a demand to manufacture the inductor at low cost.

[0012] The present application provides an inductor and a manufacturing method thereof, which can easily and reliably perform evaluation of magnetic characteristics and conduction inspection of wiring, and can manufacture the inductor at low cost.

[0013] MEANS FOR SOLVING THE PROBLEMS

[0014] The present application (1) includes a method of manufacturing an inductor, wherein the method of manufacturing an inductor has: a first step in which a wiring is prepared; a second step in which a magnetic layer is formed from a magnetic composition containing magnetic particles, the magnetic layer being formed so as to cover an outer circumferential surface of a middle portion of the wiring and an end portion of the wiring is exposed from the magnetic layer by 2 mm or more and less than 100 mm; and a third step in which the end portion of the wiring is removed.

[0015] In the method of manufacturing an inductor, in the second step, the magnetic layer is formed so that the end portion of the wiring is exposed from the magnetic layer by 2 mm or more, and therefore, it is possible to easily bring the terminal into contact with the end portion of the wiring thereafter, and the electrical connection of the terminal to the wiring is reliable. Therefore, it is possible to easily and reliably perform evaluation of magnetic characteristics and continuity inspection of the wiring.

[0016] Further, in the second step, the magnetic layer is formed so that the end portion of the wiring is exposed from the magnetic layer by less than 100 mm, and in the third step, the end portion of the wiring is removed, and therefore, it is possible to suppress the length of the removed end portion to be within a range of less than 100 mm. Therefore, it is possible to suppress the amount of the wiring to be removed, and as a result, it is possible to manufacture the inductor at low cost.

[0017] Therefore, according to the manufacturing method, it is possible to easily and reliably perform evaluation of magnetic characteristics and continuity inspection of the wiring, and it is possible to manufacture the inductor at low cost.

[0018] The present application (2) includes the method of manufacturing an inductor described in (1), wherein a length of the wiring in a thickness direction of the inductor is 1000 μm or less.

[0019] The length of the wiring in the thickness direction of the inductor is as short as 1000 μm or less, and therefore, it is possible to manufacture a thin inductor.

[0020] On the other hand, in a method of manufacturing a thin inductor, if the end surface of the wiring and the end surface of the magnetic layer are flush, as in the inductor of Patent Document 1, it is more difficult to bring the terminal into contact with the end portion thereafter.

[0021] However, as described above, in the second step, the magnetic layer is formed so that the end portion of the wiring is exposed from the magnetic layer by 2 mm or more, and therefore, even in the case where the length of the wiring in the thickness direction of the inductor is as short as 1000 μm or less, it is possible to easily bring the terminal into contact with the end portion of the wiring thereafter.

[0022] Therefore, the terminal can be easily brought into contact with the end portion of the wiring, and it is possible to manufacture a thin inductor.

[0023] The present application (3) includes the manufacturing method of the inductor described in (1) or (2), wherein, in the second step, both end portions of the wiring are exposed from the magnetic layer.

[0024] In the second step, both end portions of the wiring are exposed from the magnetic layer, and therefore, after the second step, it is possible to easily bring each of the two terminals into contact with the two end portions of the wiring, respectively, and to reliably electrically connect the two terminals to the wiring.

[0025] The present application (4) includes the manufacturing method of the inductor described in any one of (1) to (3), wherein, in the first step, the wiring is prepared, the wiring having a conductor and an insulating layer covering an outer circumferential surface of the conductor, and the manufacturing method of the inductor further has a fourth step of exposing the conductor from the insulating layer at the end portion of the wiring after the second step and before the third step.

[0026] In the first step, the wiring is prepared, the wiring having a conductor and an insulating layer covering an outer circumferential surface of the conductor, and therefore, it is possible to suppress short-circuiting between the conductor and the magnetic layer by using the insulating layer.

[0027] In addition, in the fourth step, the conductor is exposed from the insulating layer at the end portion of the wiring, and therefore, it is possible to easily bring the terminal into contact with the conductor at the end portion of the wiring, and to reliably electrically connect the terminal to the conductor.

[0028] The present application (5) includes an inductor, wherein the inductor has: a plurality of wirings; and a magnetic layer covering a middle portion of each of the plurality of wirings, the magnetic layer containing magnetic particles, and an end portion of each of the plurality of wirings being exposed from the magnetic layer in a range of 2 mm or more and less than 100 mm.

[0029] In the inductor, the end portion of each of the plurality of wirings is exposed from the magnetic layer in a range of 2 mm or more. Therefore, it is possible to easily bring a terminal into contact with the end portion of the wiring, and to reliably electrically connect the terminal to the wiring. Therefore, it is possible to easily and reliably perform evaluation of magnetic characteristics and conduction inspection of the wiring of the inductor and the like.

[0030] In addition, the end portion of each of the plurality of wirings is exposed from the magnetic layer in a range of less than 100 mm, and therefore, the inductor is manufactured by singulating the inductor and the plurality of wirings, respectively, in a manner of removing the end portions, it is possible to suppress the amount of wiring to be removed, and as a result, it is possible to manufacture a plurality of inductors at low cost.

[0031] Effects of the Invention

[0032] According to the inductor and the manufacturing method thereof of the present application, it is possible to easily and reliably perform evaluation of magnetic characteristics and conduction inspection of the wiring, and to manufacture the inductor at low cost. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 in Figure 1 A~D Figure 1 D indicates a manufacturing process diagram of the first embodiment of the manufacturing method of the inductor of the present application. Figure 1 A~D Figure 1 B indicates the first process, Figure 1 A indicates a plan view, Figure 1 B indicates Figure 1 A's front view. Figure 1 C~D Figure 1 D indicates the second process, Figure 1 C indicates a plan view, Figure 1 D indicates a front view.

[0034] Figure 2 Next Figure 1 D, indicates a manufacturing process diagram of the first embodiment. Figure 2 E~F Figure 2 F indicates the fourth process and the evaluation inspection process, Figure 2 E indicates a plan view, Figure 2 F indicates a front view. Figure 2 G~H Figure 2 H indicates the third process, Figure 2 G indicates a plan view of the inductor, Figure 3 H indicates a front view of the inductor.

[0035] Figure 1 indicates a flowchart of the manufacturing method of the first embodiment shown in Figure 2 A~D Figure 4 H.

[0036] Figure 4 in Figure 4 A~D Figure 1 C is a detailed process diagram of the second process shown in Figure 1 C~D Figure 4 D, Figure 4 A indicates a process of preparing a wiring and a first magnetic sheet, Figure 4 B indicates a process of pressing the first magnetic sheet to the wiring and a process of preparing a second magnetic sheet and a third magnetic sheet, Figure 5 C indicates a process of pressing the second magnetic sheet and the third magnetic sheet to the first magnetic sheet and the wiring to form a magnetic sheet.

[0037] Figure 2 indicates a perspective view of the evaluation inspection process shown in Figure 2 E~F Figure 6 F.

[0038] Figure 5 indicates a perspective view of the evaluation inspection process shown in Figure 7A modification of the evaluation inspection process of the first embodiment shown in FIG. 1 is explained.

[0039] Figure 1 A modification of the inductor of the first embodiment shown in Figure 1 C and Figure 8 A modification of the inductor of the first embodiment shown in FIG. 1 is explained.

[0040] Figure 2 A modification of the inductor of the first embodiment shown in Figure 9 G is explained.

[0041] Figure 2 A modification of the inductor of the first embodiment shown in Figure 10 G is explained.

[0042] Figure 2 A modification of the inductor of the first embodiment shown in Figure 11 G is explained.

[0043] Figure 11 A modification of the inductor of the first embodiment shown in Figure 11 A to Figure 2 B is a modification in which the magnetic layer is not cut but the wiring is cut. Figure 11 G is a modification of the third process of the first embodiment shown in FIG. 1, Figure 11 A indicates a modification in which the magnetic layer is not cut but the wiring is cut. Figure 12 B indicates a modification in which the magnetic layer and the wiring are cut.

[0044] Figure 13 A modification of the third process of the second embodiment of the method of manufacturing an inductor of the present application is explained.

[0045] Figure 1 A modification of the third process of the third embodiment of the method of manufacturing an inductor of the present application is explained. DETAILED DESCRIPTION

[0046] Referring to Figure 5 A to Figure 1 , a first embodiment of a method of manufacturing an inductor of the present application and an inductor obtained by the method is explained.

[0047] <First Embodiment>

[0048] As shown in Figure 2 A to Figure 3 H, in the method of manufacturing an inductor 1, an inductor 30 having a plurality of wirings 2 and a magnetic layer 3 covering the plurality of wirings 2 is manufactured, and then, a plurality of inductors 1 is manufactured from the inductor 30.

[0049] Specifically, the manufacturing method of the inductor 1 has: a first step in which the wiring 2 is prepared; a second step in which the magnetic layer 3 is formed so as to cover the intermediate portion 10 of the wiring 2 and the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3; and a third step in which the first end portion 8 and the second end portion 9 of the wiring 2 are removed. In this manufacturing method, as shown in Figure 3 the first step, the second step, and the third step are sequentially performed.

[0050] In addition, the manufacturing method further has: a fourth step of exposing the lead wire 6 from the insulating layer 7 at the first end portion 8 and the second end portion 9 of the wiring 2 after the second step and before the third step; and an evaluation inspection step of performing evaluation of inductance of a plurality of inductors 1 and conduction inspection of a plurality of wirings 2 after the fourth step and before the third step. That is, in this manufacturing method, as shown in Figure 1 the first step, the second step, the fourth step, the evaluation inspection step, and the third step are sequentially performed.

[0051] As shown in Figure 1 A ~ Figure 1 B, in the first step, a plurality of wirings 2 are prepared. The plurality of wirings 2, for example, have a first wiring 4 and a second wiring 5.

[0052] The first wiring 4 has a lead wire 6 and an insulating layer 7 that covers the lead wire 6.

[0053] The lead wire 6 extends long in the direction of flow of electricity, for example, has a shape that is substantially a letter U in plan view. Specifically, in the first step, by placing the first wiring 4 in a shape that is substantially a letter U in plan view on a water table not shown, the lead wire 6 has the above-mentioned plan view shape. The lead wire 6 has a shape that is substantially circular in cross section with a common central axis as the first wiring 4.

[0054] The material of the lead wire 6 is, for example, a metal conductor such as copper, silver, gold, aluminum, nickel, and alloys thereof, and copper is preferable. The lead wire 6 can be a single-layer structure or a multi-layer structure in which plating (e.g., nickel plating) is performed on the surface of a core conductor (e.g., copper).

[0055] The radius R1 of the lead wire 6 is the distance from the center of the lead wire 6 to the first outer peripheral surface 12, for example, is 25 μm or more, preferably 50 μm or more, and, for example, is 2000 μm or less, preferably 250 μm or less.

[0056] The insulating layer 7 is a layer for protecting the lead wire 6 from chemicals and water and preventing the lead wire 6 from short-circuiting. The insulating layer 7 is disposed so as to cover the entire surface of the first outer peripheral surface 12, which is one example of the outer peripheral surface of the lead wire 6.

[0057] The insulating layer 7 has a roughly circular shape in cross-section, sharing a central axis (center) with the first wiring 4.

[0058] Examples of materials that can be used for insulating layer 7 include polyvinyl formal, polyester, polyesterimide, polyamide (including nylon), polyimide, polyamideimide, polyurethane, and other insulating resins. These materials can be used individually or in combination of two or more. Insulating layer 7 can be composed of a single layer or multiple layers.

[0059] The thickness T1 of the insulating layer 7 is the distance from the first outer peripheral surface 12 of the conductor 6 to the second outer peripheral surface 13, which is an example of the outer peripheral surface of the first wiring 4 (wiring 2). At any position in the circumferential direction, the thickness T1 of the insulating layer 7 is approximately uniform in the radial direction of the wiring 2, for example, 1 μm or more, preferably 3 μm or more, and for example, 100 μm or less, preferably 50 μm or less.

[0060] The radius R2 of the first wiring 4 is the sum of the radius R1 of the conductor 6 and the thickness T1 of the insulation layer 7 (R1+T1). Specifically, the radius R2 of the first wiring 4 is the length R2 from the center of the first wiring 4 to the second outer peripheral surface 13. The radius R2 of the first wiring 4 is, for example, 25 μm or more, preferably 50 μm or more, and for example, 2000 μm or less, preferably 250 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less.

[0061] The diameter D of the first wiring 4 (equivalent to the thickness of the first wiring 4 in the inductor 1) is twice the radius R2 of the first wiring 4 (2×R2). Specifically, it is, for example, 50 μm or more, preferably 100 μm or more, and for example, 4000 μm or less, preferably 1000 μm or less, more preferably 500 μm or less, further preferably 400 μm or less, and especially preferably 300 μm or less.

[0062] If the radius R2 and / or diameter D of the first wiring 4 are above the lower limit mentioned above, an excellent inductance can be obtained. If the radius and / or diameter of the first wiring 4 are below the upper limit mentioned above, a thin inductor 1 can be obtained.

[0063] like Figure 1 As shown in A, the first wiring 4 also integrally has a first end portion 8 and a second end portion 9 disposed at both ends in the direction of current flow, and a midway portion 10 located in the middle of their flow direction (between them).

[0064] The first end 8 and the second end 9 are used, for example, as electrical contacts (terminals) in the evaluation and inspection process described later.

[0065] The intermediate portion 10 links the first end portion 8 and the second end portion 9 in the flow direction. The intermediate portion 10 has a curved portion 11 in the center of the flow direction of the current, the curved portion 11 having, for example, a substantially semicircular arc shape in plan view.

[0066] In addition, the intermediate portion 10 has a first linking portion 19 linked (continuous) with the first end portion 8 and a second linking portion 29 linked (continuous) with the second end portion 9.

[0067] The first linking portion 19 is arranged and formed on a straight line with the first end portion 8 in plan view. In addition, the first linking portion 19 is arranged and formed on a straight line with the first end portion 8 in a cross section along the flow direction of the current, which is not illustrated in Figure 1 A- Figure 1 B. One end of the first linking portion 19 is connected to the first end portion 8, and the other end of the first linking portion 19 is connected to one end of the curved portion 11.

[0068] The second linking portion 29 is arranged and formed on a straight line with the second end portion 9 in plan view. In addition, the second linking portion 29 is arranged and formed on a straight line with the second end portion 9 in a cross section along the flow direction of the current, which is not illustrated in Figure 1 A- Figure 1 B. One end of the second linking portion 29 is connected to the second end portion 9, and the other end of the second linking portion 29 is connected to the other end of the curved portion 11.

[0069] The intermediate portion 10 is all portions of the wiring 2 except for the first end portion 8 and the second end portion 9. In addition, the planar area of the intermediate portion 10 is, for example, 60% or more, preferably 80% or more, and, for example, 99% or less, preferably 95% or less, in each of the plurality of wirings 2.

[0070] The center-to-center distance L2 of the first end portion 8 and the second end portion 9 in cross section (or in front view) is, for example, 20 μm or more, preferably 50 μm or more, and, for example, 3000 μm or less, preferably 2000 μm or less.

[0071] The second wiring 5 is the same shape as the first wiring 4, and has the same structure and material as the first wiring 4.

[0072] The center-to-center distance L1 of the second end portion 9 of the first wiring 4 and the first end portion 8 of the second wiring 5 is, for example, 20 μm or more, preferably 50 μm or more, and, for example, 3000 μm or less, preferably 2000 μm or less.

[0073] As Figure 4 C- Figure 4As shown in FIG. 2, in the second step, the magnetic layer 3 is formed so as to cover the second outer circumferential surface 13 of the intermediate portion 10 of the wire 2 and so as to expose the first end portion 8 and the second end portion 9 of the wire 2.

[0074] In the second step, the magnetic layer 3 is formed from a magnetic composition containing magnetic particles. Specifically, the magnetic composition contains magnetic particles and a binder.

[0075] As the magnetic material constituting the magnetic particles, for example, a soft magnetic substance, a hard magnetic substance can be cited. From the viewpoint of inductance, a soft magnetic substance is preferably cited.

[0076] As the soft magnetic substance, for example, a single metal substance containing one kind of metal element in a pure substance state, an alloy substance which is a eutectic body (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.) can be cited. These materials can be used alone or in combination.

[0077] As the single metal substance, for example, a metal monomer composed of only one kind of metal element (first metal element) can be cited. As the first metal element, an appropriate selection can be made from, for example, iron (Fe), cobalt (Co), nickel (Ni), and other metal elements which can be contained as the first metal element of the soft magnetic substance.

[0078] In addition, as the single metal substance, for example, a form including a core containing only one kind of metal element and a surface layer containing an inorganic substance and / or an organic substance which modifies part or all of the surface of the core, for example, a form of an organic metal compound containing the first metal element, a form after decomposition (thermal decomposition, etc.) of an inorganic metal compound, and the like can be cited. 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, and the like can be cited. Furthermore, the position of the layer including the inorganic substance and / or the organic substance which modifies the portion containing only one kind of metal element is not limited to the surface as described above. Furthermore, the organic metal compound and the inorganic metal compound from which the single metal substance can be obtained are not particularly limited, but can be appropriately selected from publicly known or conventional organic metal compounds and inorganic metal compounds from which the single metal substance of the soft magnetic substance can be obtained.

[0079] The alloy substance is a eutectic body 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 is not particularly limited as long as it can be used as the alloy substance of the soft magnetic substance.

[0080] The first metal element is an essential element in the alloy body, and examples thereof include iron (Fe), cobalt (Co), nickel (Ni), and the like. In addition, when the first metal element is Fe, the alloy body is an Fe-based alloy, when the first metal element is Co, the alloy body is a Co-based alloy, and when the first metal element is Ni, the alloy body is a Ni-based alloy.

[0081] The second metal element is an element (an auxiliary component) that is contained in the alloy body in an auxiliary manner, and is a metal element that is compatible (eutectic) with the first metal element, and examples thereof include iron (Fe) (in the case where the first metal element is an element other than Fe), cobalt (Co) (in the case where the first metal element is an element other than Co), nickel (Ni) (in the case where the first metal element is an element other than Ni), chromium (Cr), aluminum (Al), silicon (Si), copper (Cu), silver (Ag), manganese (Mn), calcium (Ca), barium (Ba), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), ruthenium (Ru), rhodium (Rh), zinc (Zn), gallium (Ga), indium (In), germanium (Ge), tin (Sn), lead (Pb), scandium (Sc), yttrium (Y), strontium (Sr), various rare earth elements, and the like. These elements can be used alone or in combination of two or more.

[0082] The non-metal element is an element (an auxiliary component) that is contained in the alloy body in an auxiliary manner, and is a non-metal element that is compatible (eutectic) with the first metal element, and examples thereof include boron (B), carbon (C), nitrogen (N), silicon (Si), phosphorus (P), sulfur (S), and the like. These elements can be used alone or in combination of two or more.

[0083] 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 (Fe-Si-Al alloy) (including super iron-silicon-aluminum), 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 soft magnetic ferrite such as 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), permendur alloy (Fe-Co alloy), Fe-Co-V alloy, Fe-based amorphous alloy, and the like can be given.

[0084] As an example of the alloy body, Co-based alloys such as Co-Ta-Zr, cobalt (Co)-based amorphous alloy, and the like can be given.

[0085] As an example of the alloy body, Ni-based alloys such as Ni-Cr alloy, and the like can be given.

[0086] 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 an iron-silicon-aluminum (Fe-Si-Al alloy) is further preferably given. In addition, as a 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 an iron single body or iron powder (carbonyl iron powder) is further preferably given.

[0087] The volume ratio of the magnetic particles in the magnetic composition is, for example, 40% by volume or more, preferably 50% by volume or more, and more preferably 60% by volume or more, and, for example, 95% by volume or less, and preferably 90% by volume or less.

[0088] The shape of the magnetic particles is not particularly limited, and anisotropic shapes such as flat shapes (plate shapes), needle shapes, and the like, and non-anisotropic shapes such as spherical shapes, and the like can be given. From the viewpoint of orientation, anisotropic shapes are given, and from the viewpoint of good relative permeability in the planar direction (two dimensions), flat shapes are more preferably given.

[0089] The flatness ratio of the flat magnetic particles is, for example, 8 or more, preferably 15 or more, and, on the other hand, is, for example, 500 or less, preferably 450 or less. The aspect ratio is calculated as the ratio of the average particle diameter (average length) (described later) of the flat magnetic particles to the average thickness of the flat magnetic particles.

[0090] The average particle diameter (average length) of the flat magnetic particles is, for example, 3.5 μm or more, preferably 10 μm or more, and, on the other hand, is, for example, 200 μm or less, preferably 150 μm or less. If the flat magnetic particles are flat, the average thickness thereof is, for example, 0.1 μm or more, preferably 0.2 μm or more, and, on the other hand, is, for example, 3.0 μm or less, preferably 2.5 μm or less.

[0091] Further, the average particle diameter of the non-anisotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and, on the other hand, is, for example, 200 μm or less, preferably 150 μm or less.

[0092] As the binder, for example, a resin can be given, and, as such a resin, for example, a thermosetting resin such as an epoxy resin, a phenol resin, and the like, and a thermoplastic resin such as an acrylic resin, and the like can be given. These materials can be used alone or in combination.

[0093] It is preferable to use a thermosetting resin and a thermoplastic resin in combination, and it is more preferable to use an acrylic resin, an epoxy resin, and a phenol resin in combination.

[0094] Further, if necessary, a thermosetting catalyst, inorganic particles (other than magnetic particles), organic particles, a crosslinking agent, and the like can be added to the magnetic composition as an additive.

[0095] The proportions of the binder and the additive in the magnetic composition are the remaining portions other than the proportions of the magnetic particles described above in the magnetic composition.

[0096] The magnetic composition is described in detail, for example, in Japanese Patent Application Publication No. 2014-165363, and the like.

[0097] In the second step, first, a magnetic sheet 20 of, for example, a substantially rectangular sheet shape is produced from the magnetic composition described above. Further, the magnetic sheet 20 has a flat one side and another side that are opposite to each other and parallel to each other in the thickness direction. The magnetic sheet 20 is preferably a varnish of the magnetic composition that is first prepared, is applied to a release sheet that is not shown, a pre-stage sheet is prepared, and then, is heated to be a post-stage sheet.

[0098] Next, the second outer circumferential surface 13 of each of the intermediate portions 10 (the intermediate portion 10 including the curved portion 11) of the plurality of wirings 2 is covered with the magnetic sheet 20. It is preferable that the intermediate portions 10 of the plurality of wirings 2 are embedded in the magnetic sheet 20 of the B-stage sheet. Alternatively, the intermediate portions 10 of the plurality of wirings 2 are embedded in the magnetic sheet 20 of the B-stage sheet. The magnetic sheet 20 in which the intermediate portions 10 are embedded forms the magnetic layer 3.

[0099] In detail, in the second step, as shown in Figure 4 A Figure 4 The magnetic sheet 20 is prepared (manufactured) so as to independently include the first magnetic sheet 21, the second magnetic sheet 22, and the third magnetic sheet 23, respectively. The planar shape of each of the first magnetic sheet 21, the second magnetic sheet 22, and the third magnetic sheet 23 is the same as that of the magnetic sheet 20 described above. In addition, the planar dimensions of the first magnetic sheet 21, the second magnetic sheet 22, and the third magnetic sheet 23 are the same as each other.

[0100] As shown in Figure 4 A, the plurality of wirings 2 are further placed on a water platform, not shown, in the above-described arrangement. Specifically, the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2 are arranged so as to overlap when projected in the direction of their adjacency.

[0101] As shown in Figure 4 B, next, the intermediate portion 10 of each of the plurality of wirings 2 is covered with the first magnetic sheet 21 (preferably, the first magnetic sheet 21 of the B-stage). In detail, the first magnetic sheet 21 is pressed toward the intermediate portion 10 from the one side in the thickness direction. Thereby, the entire surface of the second outer circumferential surface 13 (except for the other end edge in the thickness direction) of the intermediate portion 10 is covered with the first magnetic sheet 21. Further, the first magnetic sheet 21 after the pressing is still of the B-stage in the case where the magnetic composition contains a thermosetting resin.

[0102] In the first magnetic sheet 21, the one side in the thickness direction has a curved surface corresponding to the wiring 2 when viewed in the front (or in the cross section).

[0103] As shown in Figure 1 C, next, the second magnetic sheet 22 and the third magnetic sheet 23 (each of the second magnetic sheet 22 and the third magnetic sheet 23 is preferably of the B-stage in the case where the magnetic composition contains a thermosetting resin) are arranged on the one side and the other side in the thickness direction of the intermediate portion 10 and the first magnetic sheet 21, respectively, and are pressed with respect to the intermediate portion 10 and the first magnetic sheet 21. Further, the second magnetic sheet 22 and the third magnetic sheet 23 after the pressing are still of the B-stage in the case where the magnetic composition contains a thermosetting resin.

[0104] Thus, the magnetic sheet 20 is formed in a manner to cover the second outer peripheral surface 13 of the plurality of wirings 2, and the magnetic sheet 20 has the second magnetic sheet 22, the first magnetic sheet 21, and the third magnetic sheet 23 in this order from the one side to the other side in the thickness direction. Further, as shown in Figure 1 C, the boundaries of the second magnetic sheet 22, the first magnetic sheet 21, and the third magnetic sheet 23 are clearly drawn, but, for example, in the laminated sheet of the second magnetic sheet 22, the first magnetic sheet 21, and the third magnetic sheet 23, i.e., the magnetic sheet 20, the boundaries thereof can not be clear, and more specifically, as shown in Figure 2 D, the boundaries can not be confirmed.

[0105] The one side of the magnetic sheet 20 in the thickness direction has a flat surface.

[0106] On the other hand, the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2 are exposed from the magnetic sheet 20. Specifically, the first end portion 8 and the second end portion 9 protrude from one end surface (front end surface) 16 of the four peripheral end surfaces of the magnetic sheet 20.

[0107] Further, as shown in Figure 5 C, the length L of each of the first end portion 8 and the second end portion 9 exposed from the magnetic sheet 20 is in a range of 2 mm or more and less than 100 mm.

[0108] If the length L is less than 2 mm, as shown in Figure 2 E and Figure 1 in the evaluation inspection process (described later), the terminal 25 (described later) cannot be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 and the wiring 2 is not reliable. Therefore, the evaluation of the magnetic properties of the inductor 1 and the conduction inspection of the wiring 2 cannot be easily and reliably performed.

[0109] On the other hand, if the length L is 100 mm or more, as shown in Figure 1 G, in the third process (described later), if the first end portion 8 and the second end portion 9 of the wiring 2 are considered to be removed, the length L of the removed first end portion 8 and the second end portion 9 cannot be suppressed to be in a range of less than 100 mm. Therefore, the amount of removed wiring cannot be suppressed, and thus, the yield of the wiring 2 is reduced, and as a result, the inductor 1 cannot be manufactured at a low cost.

[0110] In detail, the range of the length L is preferably 3 mm or more, more preferably 4 mm or more, further preferably 5 mm or more, still further preferably 10 mm or more, and in addition, preferably 99 mm or less, more preferably 95 mm or less, further preferably 75 mm or less, particularly preferably 50 mm or less, most preferably 40 mm or less, and also preferably 25 mm or less.

[0111] Then, if the magnetic sheet 20 is still B-stage, it is C-staged.

[0112] As shown in Figure 2 C- Figure 2 D, thereby forming the magnetic layer 3 composed of the magnetic sheet 20 so as to expose the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2 and cover the intermediate portion 10 of each of the plurality of wirings 2.

[0113] In the second process, the inductor 30 having the plurality of wirings 2 and the magnetic layer 3 covering the intermediate portion 10 of each of the plurality of wirings 2 is obtained. In the inductor 30, the magnetic layer 2 contains the magnetic particles, and the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2 are exposed from the magnetic layer 3 in a direction orthogonal to the thickness direction of the magnetic layer 3 in a range of 2 mm or more and less than 100 mm.

[0114] As shown in Figure 2 G and Figure 2 H, the inductor 30 is a collection sheet for obtaining the inductor 1 described later, and is not the inductor 1 itself, and includes the first end portion 8 and the second end portion 9 in addition to the plurality of inductors 1. The inductor 30 is a device that is separately circulated and can be utilized in industry.

[0115] The thickness of the inductor 30 is the same as the thickness of the magnetic layer 3, and specifically, for example, is 5000 μm or less, and preferably, 1000 μm or less, and on the other hand, for example, is 100 μm or more.

[0116] As shown in Figure 2 F, in the fourth process, the conductor 6 is exposed from the insulating layer 7 at the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2.

[0117] For example, by laser processing or the like in which laser light is irradiated from the thickness direction side, at the first end portion 8 and the second end portion 9, a portion of the insulating layer 7 opposite the thickness direction one end portion of the first outer peripheral surface 12 of the conductor 6 is removed, and the thickness direction one end portion of the first outer peripheral surface 12 of the conductor 6 is exposed from the insulating layer 7.

[0118] Alternatively, the thickness direction one end portion of the first outer peripheral surface 12 of the conductor 6 can be exposed from the insulating layer 7 by polishing.

[0119] In the evaluation inspection process, for example, evaluation of the inductance of the plurality of inductors 1 and conduction inspection of the plurality of wirings 2 are performed.

[0120] Specifically, one pair of terminals 25 is disposed at the thickness direction side of the first end portion 8 and the second end portion 9, and the thickness direction other surface of the one pair of terminals 25 is brought into contact with the first outer peripheral surface 12 of the conductor 6 exposed from the insulating layer 7 at the first end portion 8 and the second end portion 9.

[0121] The shape of the terminal 25 is not particularly limited, and examples that can be given include a substantially cylindrical shape having a large flat surface on the other end surface in the thickness direction, a needle shape that extends long in the thickness direction of the inductor 30, and the like, from the viewpoint of convenience and ensuring a large contact area with the wire 6, and a substantially cylindrical shape can be given as an example.

[0122] The terminal 25 is connected to an inspection device (specifically, an LCR meter, a vector network analyzer, an impedance analyzer, or the like) via a connection line (not shown).

[0123] In the evaluation of the inductance, while a weak current is applied to one pair of terminals 25, the impedance is measured, and the measured value is substituted into a theoretical formula, whereby the inductance determined by one wiring 2 and the magnetic layer 3 around it is calculated.

[0124] In the conduction inspection of the wiring 2, whether the wiring 2 is conductive or not is confirmed by measuring the resistance between one pair of terminals 25.

[0125] As shown in Figs. 1 and 2, the inductor 30 is obtained by forming the wiring 2 and the magnetic layer 3 on the substrate 10. Figure 1 G ~ Figure 1 H, in the third step, the first end portion 8 and the second end portion 9 of the wiring 2 are removed.

[0126] Specifically, the inductor 30 is cut in a manner corresponding to each of the plurality of wirings 2 and separated from the first end portion 8 and the second end portion 9, and the inductor 1 is obtained.

[0127] At this time, not only the exposed first end portion 8 and the second end portion 9 are removed, but also the inside of the magnetic layer 3 is removed.

[0128] For example, the wiring 2 and the magnetic layer 3 are cut in a manner that a first cut line 26 is formed inward of the peripheral end surface of the magnetic layer 3 when viewed from above, and the magnetic layer 3 is cut in a manner that a second cut line 27 is formed between adjacent first wiring 4 and second wiring 5. The above cutting can be performed using, for example, cutting, laser processing, punching processing, or the like.

[0129] Thus, a plurality of inductors 1 having one wiring 2 and one magnetic layer 3 covering the entire second outer peripheral surface 13 in the flow direction are obtained. That is, the inductor 1 is cut from the inductor 30 with the first end portion 8 and the second end portion 9 remaining in the inductor 30 (cut down). That is, the inductor 1 is obtained by removing the first end portion 8 and the second end portion 9. Furthermore, the inductor 1 preferably has only one wiring 2 and one magnetic layer 3.

[0130] The inductor 1 has, for example, a rectangular flat plate shape, and specifically, a plurality (four) of flat peripheral end surfaces. The inductor 1 does not include the first end portion 8 and the second end portion 9. The inductor 1 is a separate flow-through device that can be utilized in industry.

[0131] In one of the four peripheral end surfaces 18 of the inductor 1, the end surface of the wiring 2 and the end surface of the magnetic layer 3 are formed flush.

[0132] The thickness of the inductor 1 is the same as the thickness of the magnetic layer 3 described above.

[0133] Further, in the manufacturing method of the inductor 1, as shown in Figure 2 C ~ Figure 2 D, in the second step, the magnetic layer 3 is formed in such a manner that the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3 by 2 mm or more. Therefore, as shown in Figure 2 E ~ Figure 5 F, in the evaluation and inspection step after the second step, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 and the wiring 2 is reliable. Therefore, the evaluation of the inductance of the inductor 1 and the inductor 30 and the continuity inspection of the wiring 2 can be easily and reliably performed.

[0134] In detail, since the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3 by 2 mm or more, the terminal 25 having various shapes can be brought into contact with the lead wire 6, as shown in Figure 1 F and Figure 1 for example, a needle-shaped terminal 25 (solid line) having a sharp thickness direction other end (top end) can of course be brought into contact with the lead wire 6, and a substantially cylindrical terminal 25 (dashed line) can also be brought into contact with the lead wire 6. Thus, regardless of the shape and / or size of the terminal 25 and the like, the terminal 25 can be easily and reliably brought into contact with the wiring 2. That is, the degree of freedom of the terminal 25 that can be used is high, and therefore, the inspection and evaluation using the terminal 25 can be easily performed.

[0135] On the contrary, in the case where the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3 by less than 2 mm, the needle-shaped terminal 25 (solid line) can be brought into contact with the lead wire 6, but it is difficult to bring the substantially cylindrical terminal 25 (dashed line) into contact with the lead wire 6.

[0136] Further, as shown in Figure 2 C ~ Figure 2 D, in the second step, the magnetic layer 3 is formed in such a manner that the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3 by less than 100 mm, as shown in Figure 1 G ~ Figure 2 H, in the third step, the first end portion 8 and the second end portion 9 of the wiring 2 are removed, and therefore, the length L of the removed first end portion 8 and the second end portion 9 can be suppressed to be less than 100 mm. Therefore, the amount (or length) of the wiring 2 to be removed can be suppressed, and therefore, the yield of the wiring 2 is excellent, and as a result, the inductor 1 can be manufactured at a low cost.

[0137] Thus, according to the manufacturing method, evaluation of the inductance of the inductor 1 and conduction inspection of the wiring 2 can be easily and reliably performed, and the inductor 1 can be manufactured at low cost.

[0138] Further, in the manufacturing method, in the case where the diameter D of the wiring 2 is as small as 1000 μm or less, the inductor 1 can be manufactured to be thin.

[0139] On the other hand, in the method of manufacturing the inductor 1 to be thin, if the end surface of the wiring 2 and the one end surface 16 of the magnetic layer 3 are flush, as in the inductor of Patent Document 1, it is more difficult for the terminal 25 to contact the end surface of the wiring 2 thereafter.

[0140] However, in the first embodiment, as described above, in the second process, the magnetic layer 3 is formed so that the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3 by 2 mm or more, and thus, even in the case where the diameter D of the wiring 2 is as small as 500 μm or less, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 thereafter.

[0141] Thus, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the inductor 1 can be manufactured to be thin.

[0142] Further, as described above, Figure 1 C, in the second process of the first embodiment, the first end portion 8 and the second end portion 9 of the wiring 2 are exposed from the magnetic layer 3, and thus, after the second process, in the evaluation inspection process shown in Figure 2 E, the two terminals 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, respectively, and the electrical connection of the two terminals 25 with the wiring 2 is reliable.

[0143] As shown in Figure 5 B, in the first process of the first embodiment, even if the wiring 2 having the conductor 6 and the insulating layer 7 covering the first outer surface 12 of the conductor 6 is prepared, since the conductor 6 is exposed from the insulating layer 7 at the first end portion 8 and the second end portion 9 of the wiring 2 as shown in Figure 1 F and Figure 1 C, in the fourth process, the conductor 6 is exposed from the insulating layer 7 at the first end portion 8 and the second end portion 9 of the wiring 2, and thus, the terminal 25 can be easily brought into contact with the conductor 6 at the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the conductor 6 is reliable.

[0144] In the inductor 30 of the first embodiment shown in Figure 2 C to Figure 2 D, the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2 are exposed from the magnetic layer 3 by 2 mm or more. Thus, as shown in Figure 2 E toFigure 5 As shown in FIG. 9, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the wiring 2 is reliable. Thus, the evaluation of the inductance of the inductor 1 and the conduction check of the wiring 2 can be easily and reliably performed.

[0145] Further, since the first end portion 8 and the second end portion 9 of each of the plurality of wirings 2 are exposed from the magnetic layer 3 in a range of less than 100 mm, even if the inductor 30 is singulated to manufacture the inductor 1 in a manner that the first end portion 8 and the second end portion 9 are removed in correspondence with the plurality of wirings 2, respectively, the amount of the wiring to be removed can be suppressed, and as a result, the plurality of inductors 1 can be manufactured at low cost.

[0146] Modified Example

[0147] In each of the following modified examples, the same reference numerals are assigned to the same members and processes as those of the first embodiment described above, and detailed description thereof is omitted. Further, each of the modified examples can achieve the same effects as the first embodiment except for the specifically described contents. Moreover, the first embodiment and the modified examples can be appropriately combined.

[0148] As shown in FIG. 9, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the wiring 2 is reliable. Thus, the evaluation of the inductance of the inductor 1 and the conduction check of the wiring 2 can be easily and reliably performed. Figure 6 E and Figure 1 As shown in FIG. 9, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the wiring 2 is reliable. Thus, the evaluation of the inductance of the inductor 1 and the conduction check of the wiring 2 can be easily and reliably performed.

[0149] As shown in FIG. 9, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the wiring 2 is reliable. Thus, the evaluation of the inductance of the inductor 1 and the conduction check of the wiring 2 can be easily and reliably performed. Figure 5 E and

[0150] That is, in the fourth process, the entire insulating layer 7 at the first end portion 8 and the second end portion 9 can be removed.

[0151] Further, as shown in FIG. 9, in the first embodiment, both the first end portion 8 and the second end portion 9 are exposed from the magnetic layer 3 in the second process (the inductor 30). However, only either one of the first end portion 8 and the second end portion 9 can be exposed from the magnetic layer 3, for which no illustration is shown. Figure 7 C, in the first embodiment, both the first end portion 8 and the second end portion 9 are exposed from the magnetic layer 3 in the second process (the inductor 30). However, only either one of the first end portion 8 and the second end portion 9 can be exposed from the magnetic layer 3, for which no illustration is shown.

[0152] As shown in FIG. 9, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the wiring 2 is reliable. Thus, the evaluation of the inductance of the inductor 1 and the conduction check of the wiring 2 can be easily and reliably performed. Figure 4 E and Figure 4 As shown in FIG. 9, the terminal 25 can be easily brought into contact with the first end portion 8 and the second end portion 9 of the wiring 2, and the electrical connection of the terminal 25 with the wiring 2 is reliable. Thus, the evaluation of the inductance of the inductor 1 and the conduction check of the wiring 2 can be easily and reliably performed. E and

[0153] The thickness T2 of the wire 2 of this modification example is the same as the diameter D of the wire 2 in the first embodiment.

[0154] Further, in this modification example, the corner portion of the wire 2 in cross section (for example, a corner portion formed by both outer sides of the thickness direction side and the adjacent direction (a direction in which the first wire 4 and the second wire 5 are adjacent to each other)) can also have a curved shape, for example.

[0155] Further, as shown in Figure 2 A ~ Figure 8 C, in the first embodiment, the magnetic layer 3 is formed as a laminated piece of three magnetic pieces (the first magnetic piece 21, the second magnetic piece 22, and the third magnetic piece 23), but the number thereof is not limited thereto and can be one, two, or four or more.

[0156] Further, in the second process of the first embodiment, the wire 2 is covered with the magnetic piece 20 (the magnetic layer 3) formed in a piece shape, but for example, a varnish of a magnetic composition can be applied to the wire 2, and then the magnetic layer 3 can be formed by forming the magnetic composition in a piece shape.

[0157] As shown in Figure 2 G, in the third process of one embodiment, the portion of the wire 2 that is buried in the middle portion 10 of the magnetic layer 3 is cut. That is, the inductor 30 is cut in a manner to form the first cut line 26.

[0158] However, in this modification example, as shown in Figure 9 , the portion of the wire 2 that is not buried in the magnetic layer 3 (specifically, the boundary portion of the wire 2 and the middle portion 10) can also be cut. The wire 2 is cut in a manner to form the third cut line 28 along the end surface of the inductor 30.

[0159] As shown in Figure 9 G, in the third process of one embodiment, the magnetic layer 3 is cut in a manner to singulate the plurality of wires 2, that is, to form the second cut line 27.

[0160] As shown in Figure 10 , in the modification example, the magnetic layer 3 is cut in a manner not to singulate the plurality of wires 2, that is, not to form the second cut line 27. The inductor 1 obtained by the third process has the plurality of wires 2.

[0161] In the modification example of Figure 1 , the magnetic layer 3 and the wire 2 are cut.

[0162] However, in the modification example, as shown in Figure 11 , the magnetic layer 3 can also be cut without cutting the wire 2. The wire 2 is cut in a manner to form the third cut line 28.

[0163] In one embodiment, asFigure 11 As shown in C, an inductor 30 having a plurality of the wirings 2 is manufactured.

[0164] However, as shown in Figure 11 A and Figure 11 B, in a modification, an inductor preparation sheet 15 having one wiring 2 can be manufactured.

[0165] As shown in Figure 4 A, in the third step, the wiring 2 and the magnetic layer 3 are cut in a manner to form a first cut line 26.

[0166] Or as shown in Figure 1 B, in the third step, the wiring 2 is cut in a manner to form a third cut line 28.

[0167] In the evaluation inspection step of the embodiment, both the evaluation of the inductance of the inductor 1 and the conduction inspection of the wiring 2 are implemented, but either one of them can be implemented.

[0168] Further, the proportion of the magnetic particles in the magnetic layer 3 can be uniform in the magnetic layer 3, and in addition, can be higher or lower as it is farther from each wiring 2. In order to manufacture the inductor 1 in which the proportion of the magnetic particles in the magnetic layer 3 is higher as it is farther from the wiring 2, for example, as shown in Figure 1 B, the proportion of the presence of the magnetic particles in the second magnetic sheet 22 and the proportion of the presence of the magnetic particles in the third magnetic sheet 23 are set to be higher than the proportion of the presence of the magnetic particles in the first magnetic sheet 21.

[0169] <2nd Embodiment>

[0170] In the following 2nd embodiment, for the same members and steps as those of the above-described 1st embodiment and the modification thereof, the same reference numerals are attached, and the detailed explanation thereof is omitted. In addition, the 2nd embodiment can have the same functional effects as the 1st embodiment and the modification thereof except for the specifically described contents. Also, the 1st embodiment, the modification thereof, and the 2nd embodiment can be appropriately combined.

[0171] In the 1st embodiment, as shown in Figure 1 A and manufactured in the first step, and the wiring 2 of the inductor 30 Figure 1 C) manufactured in the second step has a shape of a substantially letter U in plan view. Figure 12 Figure 1 However, the plan view shape of the wiring 2 is not limited to the above-described shape.

[0172] For example, as shown in

[0173] For example, as shown in Figure 13 ​As shown, in the second embodiment, the above-described wiring 2 has a substantially meandering shape in plan view.

[0174] The middle portion 10 of the wiring 2 also has a substantially meandering shape in plan view, and more specifically, has a curved portion 14 that is bent in plan view. The curved portion 14 is provided with a plurality of portions spaced apart from each other in the flow direction of electricity in the middle portion 10.

[0175] In the inductor 30, the first end portion 8 and the second end portion 9 are exposed from one end surface (front end surface) 16 and the other end surface (rear end surface) 17, respectively, of the four peripheral end surfaces of the magnetic layer 3, which are opposed to each other with a space therebetween.

[0176] <Third Embodiment>

[0177] In the following third embodiment, the same reference numerals are assigned to the same components and processes as those of the above-described first embodiment, the modification example thereof, and the second embodiment, and detailed description thereof is omitted. In addition, the third embodiment can achieve the same effects as the first embodiment, the modification example thereof, and the second embodiment, except for the specifically described contents. Furthermore, the first embodiment, the modification example thereof, the second embodiment, and the third embodiment can be appropriately combined.

[0178] As shown in FIG. 1, in the first embodiment, in the inductor 30, the entire middle portion 10 is buried in the magnetic layer 3 in the flow direction. Figure 1 As shown in FIG. 1, in the first embodiment, in the inductor 30, the entire middle portion 10 is buried in the magnetic layer 3 in the flow direction.

[0179] Figure 1 As shown in FIG. 1, in the first embodiment, in the inductor 30, the entire middle portion 10 is buried in the magnetic layer 3 in the flow direction.

[0180] Specifically, in the inductor 30, the curved portion 11 corresponding to the substantially central portion 18 in the flow direction in the middle portion 10 (wiring 2) is exposed from the other end surface 17 of the magnetic layer 3.

[0181] In the evaluation inspection process, the terminal 25 is not brought into contact with the curved portion 11, but is brought into contact with the first end portion 8 and the second end portion 9.

[0182] In the third process, the first end portion 8 and the second end portion 9 are removed, and on the other hand, the wiring 2 and the magnetic layer 3 are cut in a manner that the curved portion 11 is left. That is, the inductor 1 is accompanied by the curved portion 11.

[0183] Thus, the inductor 1 having the magnetic layer 3 and the wiring 2 having the curved portion 11 exposed from the magnetic layer 3 and the portion (portion other than the curved portion 11 in the middle portion 10) buried in the magnetic layer 3 is obtained.

[0184] [Embodiment] ​

[0185] The following shows examples and comparative examples, further specifically illustrating the present application. Furthermore, the present application is not limited to any of the examples and comparative examples. In addition, in the following description, the specific numerical values of the formulation ratio (content ratio), physical property values, parameters, etc. used can be replaced by the upper limit (the numerical value defined as "or less," "less than") or lower limit (the numerical value defined as "or more," "more than") of the corresponding description of the formulation ratio (content ratio), physical property values, parameters, etc. described in the above "DETAILED DESCRIPTION."

[0186] Example 1

[0187] As shown in Figure 1 A ~ Figure 1 D, the first process and the second process were sequentially performed, and the inductor 30 shown in Figure 1 C and Figure 4 D was obtained.

[0188] As shown in Figure 4 A ~ Figure 1 B, in the first process, a plurality of wires 2 having a diameter D of 220 μm (a radius R2 of 110 μm) were prepared. In detail, a plurality of wires 2 having a lead wire 6 with a radius Rl of 100 μm and an insulating layer 7 with a thickness Tl of 10 μm were prepared, and were placed on a water table not shown in a figure in a shape of a letter U in a plan view.

[0189] In addition, a laminated sheet (refer to Figure 2 A ~ Figure 2 C) of a magnetic sheet 20 containing magnetic particles and a binder (more specifically, a first magnetic sheet 21, a second magnetic sheet 22, and a third magnetic sheet 23) was attached to the lead wire 6.

[0190] As shown in ​ C, the length L of each of the first end portion 8 and the second end portion 9 was 10 mm.

[0191] As shown in ​ E ~ ​ H, thereafter, the fourth process and the third process were sequentially performed, and the inductor 1 was obtained.

[0192] Example 2 ~ Comparative Example 2

[0193] According to the description of Table 1, the same processing as in Example 1 was performed except that the length L was changed, and the inductor 30 was produced, and then the inductor 1 was obtained.

[0194] [Inspection easiness in the inspection evaluation process]

[0195] The ease of inspection of the inductor 30 during the manufacturing process of each of the examples and each of the comparative examples was evaluated in accordance with the following criteria. The results thereof are described in Table 1.

[0196] The needle-shaped terminal 25 having a diameter of 5 mm and the cylindrical terminal 25 having a diameter of 5 mm are both capable of contacting the first end portion 8 and the second end portion 9, capable of measuring the inductance of the inductor 1, and capable of performing the continuity check of the wiring 2.

[0197] The needle-shaped terminal 25 having a diameter of 5 mm is capable of contacting the first end portion 8 and the second end portion 9, capable of measuring the inductance of the inductor 1, and capable of performing the continuity check of the wiring 2. However, the cylindrical terminal 25 having a diameter of 5 mm is incapable of contacting the first end portion 8 and the second end portion 9, incapable of measuring the inductance of the inductor 1, and also incapable of performing the continuity check of the wiring 2.

[0198] The needle-shaped terminal 25 having a diameter of 5 mm and the cylindrical terminal 25 having a diameter of 5 mm are both incapable of contacting the first end portion 8 and the second end portion 9, incapable of measuring the inductance of the inductor 1, and also incapable of performing the continuity check of the wiring 2.

[0199] [Manufacturing Cost]

[0200] The removal amount of the first end portion 8 and the second end portion 9 in the third process of each of the examples and each of the comparative examples was measured, and the manufacturing cost was evaluated in accordance with the following criteria. The results thereof are described in Table 1.

[0201] The length L of each of the first end portion 8 and the second end portion 9 of the wiring 2 is 40 mm or less

[0202] The length L of each of the first end portion 8 and the second end portion 9 of the wiring 2 exceeds 40 mm and is less than 100 mm

[0203] The length L of each of the first end portion 8 and the second end portion 9 of the wiring 2 is 100 mm or more

[0204] [Table 1]

[0205]

[0206] Furthermore, the above-described application is provided as an example of an embodiment of the present application, but this is merely an example and cannot be interpreted limitatively. The modifications of the present application that can be apparent to those skilled in the art are included in the aforementioned claims.

[0207] Industrial Applicability

[0208] The inductor is mounted on, for example, an electronic device or the like.

[0209] Explanation of Reference Numerals

[0210] 1, inductor; 2, wire; 3, magnetic layer; 6, wire; 7, insulating layer; 8, 1st end; 9, 2nd end; 10, intermediate portion; 13, 2nd outer peripheral surface; 30, inductor; L, length of end; D, diameter of wire having substantially circular cross section; T2, thickness of wire having substantially rectangular cross section.

Claims

1. A method of manufacturing an inductor, characterized by comprising: a first step of preparing a wiring having a conductor and an insulating layer covering the conductor, the insulating layer being made of an insulating resin; a second step of forming a magnetic layer from a magnetic composition containing magnetic particles, the magnetic layer being formed to cover an outer peripheral surface of an intermediate portion of the wiring and to expose an end portion of the wiring by 2 mm or more and less than 100 mm from the magnetic layer; an evaluation inspection step of bringing a terminal connected to an inspection device into contact with an outer peripheral surface of the end portion of the wiring, and inspecting the wiring using the inspection device; and a third step of removing the end portion of the wiring after the evaluation inspection step.

2. The method of manufacturing an inductor according to claim 1, characterized in that a length of the wiring in a thickness direction of the inductor is 1000 μm or less.

3. The method of manufacturing an inductor according to claim 1, characterized in that both end portions of the wiring are exposed from the magnetic layer in the second step.

4. The method of manufacturing an inductor according to claim 1, characterized in that the wiring having a conductor and an insulating layer covering an outer peripheral surface of the conductor is prepared in the first step, and the method further comprises a fourth step of exposing the conductor from the insulating layer at the end portion of the wiring after the second step and before the third step.

5. An inductor, characterized by comprising: a plurality of wirings having a conductor and an insulating layer covering the conductor, the insulating layer being made of an insulating resin; and a magnetic layer covering an intermediate portion of each of the plurality of wirings, the magnetic layer containing magnetic particles, an end portion of each of the plurality of wirings being exposed from the magnetic layer by 2 mm or more and less than 100 mm, and at least a thickness direction one end portion of the conductor being exposed from the insulating layer at the end portion of each of the plurality of wirings. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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