inductor

Abstract

An inductor (1) has a wire (2) and a magnetic layer (3) covering the wire (2), the wire (2) has a conductor wire (6) and an insulating layer (7), the magnetic layer (3) contains anisotropic magnetic particles (8) and a binder (9), in a peripheral region (11) of the wire (2), the magnetic layer (3) has an orientation region (13), the peripheral region (11) is a region that, when sectioned, advances from the outer surface of the wire (2) to the outside by a value of 1.5 times the average of the longest length and the shortest length from the center of gravity of the wire (2) to the outer surface of the wire (2), and the inductor (1) has a convex portion (10) due to the wire (2) on the upper surface.

Description

Technical Field

[0001] This invention relates to an inductor. Background Technology

[0002] Inductors are known to be passive components mounted in electronic devices and used as voltage conversion components.

[0003] For example, an inductor is proposed comprising: a rectangular substrate body formed of a magnetic material; and an internal conductor, such as copper, embedded within the substrate body, wherein the cross-sectional shape of the substrate body and the cross-sectional shape of the internal conductor are similar (see Patent Document 1). That is, in the inductor of Patent Document 1, the wiring (internal conductor), which is rectangular in cross-section (cubic parallelepiped), is surrounded by a magnetic material.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 10-144526 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, inductors require further improvements in inductance.

[0009] In addition, the inductor is mounted on the desired wiring board. At this time, since the internal conductor of Patent Document 1 is covered by a magnetic material, it is necessary to perform a path processing from the thickness direction of the inductor to expose the internal conductor and conduct through the exposed internal conductor.

[0010] However, in the inductor of Patent Document 1, when the path is processed from the thickness direction, the position of the internal conductor cannot be identified. That is, an opening 41 (path) is formed at a position away from the area where the internal conductor 40 is located (see...). Figure 8 ), it is difficult for pathway processing to succeed with a 100% probability.

[0011] The present invention provides an inductor with good inductance and reliable path processing capability.

[0012] Solution for solving the problem

[0013] The present invention [1] includes an inductor having wiring and a magnetic layer covering the wiring, the wiring having conductors and an insulating layer covering the conductors, the magnetic layer containing anisotropic magnetic particles and an adhesive, the magnetic layer having an orientation region in the peripheral region of the wiring in which the anisotropic magnetic particles are oriented along the periphery of the wiring, the peripheral region being a region that, in cross-section, extends outward from the outer surface of the wiring by a value equivalent to 1.5 times the average of the longest and shortest lengths from the centroid of the wiring to the outer surface of the wiring, and having a protrusion in the thickness direction of the inductor caused by the wiring.

[0014] According to this inductor, there are anisotropic magnetic particles in the periphery of the wiring, and the orientation region is oriented along the surrounding area, so the inductance is good.

[0015] Furthermore, since the inductor has a protrusion on one side in the thickness direction caused by wiring, the wiring can be reliably exposed if a path is processed on the protrusion. Therefore, path processing can be reliably achieved.

[0016] The present invention [2] includes the inductor described in [1], wherein the wiring is arranged in a plurality of spaced-apart in an orthogonal direction orthogonal to the thickness direction, the plurality of wiring being continuous across the magnetic layer.

[0017] According to this inductor, since a continuous magnetic layer is arranged between multiple wirings in a direction orthogonal to the multiple wirings, the inductance is good.

[0018] The present invention [3] includes the inductor described in [1] or [2], wherein the cross-sectional shape of the wiring is circular.

[0019] Because the cross-sectional shape of the wiring is circular, there are no corners. Therefore, it is easy to orient anisotropic magnetic particles along the periphery (circumferential direction) of the wiring. Thus, an oriented region can be reliably formed, and inductance can be reliably improved.

[0020] The effects of the invention

[0021] The inductor according to the present invention has good inductance and can reliably realize path processing. Attached Figure Description

[0022] Figure 1 In Figure 1 A- Figure 1 B represents the first embodiment of the inductor of the present invention. Figure 1 A represents the top view. Figure 1 B indicates Figure 1 Sectional view of A.

[0023] Figure 2 express Figure 1 A magnified view of the dashed section of B.

[0024] Figure 3 In Figure 3 A- Figure 3 B indicates Figure 1 A- Figure 1 The manufacturing process diagram of the inductor shown in B is as follows. Figure 3 A represents the configuration process. Figure 3 B indicates the stacking process.

[0025] Figure 4 Indicates to Figure 1 The inductor shown in B is a cross-sectional view of the circuit fabrication process.

[0026] Figure 5 express Figure 1 A- Figure 1 Example of a modified inductor shown in B (with a single wiring configuration).

[0027] Figure 6 A partially enlarged cross-sectional view showing the second embodiment of the inductor of the present invention.

[0028] Figure 7 Indicates to Figure 6 The inductor shown is a cross-sectional view of the circuit fabrication process.

[0029] Figure 8 This is a cross-sectional view showing the process of fabricating a path for a conventional inductor. Detailed Implementation

[0030] exist Figure 1 In diagram A, the left-right direction of the paper is direction 1, the left side of the paper is one side of direction 1, and the right side of the paper is the other side of direction 1. The up-down direction of the paper is direction 2 (orthogonal to direction 1), the upper part of the paper is one side of direction 2 (one direction along the axis of the wiring), and the lower part of the paper is the other side of direction 2 (the other direction along the axis of the wiring). The paper thickness direction is the up-down direction (orthogonal to directions 1 and 2, i.e., the thickness direction), the front side of the paper is the upper side (one side of direction 3, i.e., the thickness direction), and the depth side of the paper is the lower side (the other side of direction 3, i.e., the other side of the thickness direction). Specifically, the directional arrows in each diagram are used as a reference.

[0031] <First Embodiment>

[0032] 1. Inductor

[0033] Reference Figure 1 A- Figure 2 This describes one embodiment of the first embodiment of the inductor of the present invention.

[0034] like Figure 1 A and Figure 1 As shown in Figure B, the inductor 1 has a generally rectangular shape when viewed from above, extending along the planar directions (the first direction and the second direction).

[0035] Inductor 1 has multiple (two) wirings 2 and a magnetic layer 3.

[0036] The plurality of wirings 2 include a first wiring 4 and a second wiring 5, the second wiring 5 being arranged at intervals from the first wiring 4 in the width direction (the first direction; the orthogonal direction orthogonal to the thickness direction).

[0037] like Figure 1 A and Figure 1 As shown in Figure B, the first wiring 4 extends relatively long in the second direction, for example having a roughly U-shaped form when viewed from above. Additionally, the first wiring 4 has a roughly circular shape when viewed in cross-section.

[0038] The first wiring 4 has a conductor 6 and an insulating layer 7 covering the conductor 6.

[0039] The conductor 6 extends relatively long in the second direction, for example, having a roughly U-shaped form when viewed from above. Additionally, the conductor 6 has a roughly circular shape when viewed in cross-section, sharing a central axis with the first wiring 4.

[0040] The material of the conductor 6 is a metallic conductor such as copper, silver, gold, aluminum, nickel, and their alloys, with copper being a preferred example. The conductor 6 can be a single-layer structure or a multi-layer structure formed by plating (e.g., nickel plating) on ​​the surface of the core conductor (e.g., copper).

[0041] The radius R1 of the conductor 6 is, for example, 25 μm or more, preferably 50 μm or more, and also, for example, 2000 μm or less, preferably 200 μm or less.

[0042] Insulation layer 7 is used to protect conductor 6 from chemicals and water and to prevent short circuits in conductor 6. Insulation layer 7 is configured to cover the entire outer circumference of conductor 6.

[0043] The insulating layer 7 has a roughly circular shape in cross-section, sharing a central axis (center C1) with the first wiring 4.

[0044] Materials used as insulating layer 7 include, for example, insulating resins such as polyvinyl formal, polyester, polyesterimide, polyamide (including nylon), polyimide, polyamideimide, and polyurethane. One of these materials may be used alone, or two or more may be used in combination.

[0045] The insulating layer 7 can be composed of a single layer or multiple layers.

[0046] For the thickness R2 of the insulating layer 7, at any position in the circumferential direction, the thickness R2 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.

[0047] The ratio (R1 / R2) of the radius R1 of the conductor 6 to the thickness R2 of the insulation layer 7 is, for example, 1 or more, preferably 10 or more, for example, 200 or less, and preferably 100 or less.

[0048] The radius (R1+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 200 μm or less.

[0049] When the first wiring 4 is approximately U-shaped, the center-to-center distance D2 of the first wiring 4 is the same as the center-to-center distance D1 between the plurality of wirings 2 described later, for example, 20 μm or more, preferably 50 μm or more, and for example, 3000 μm or less, preferably 2000 μm or less.

[0050] The second wiring 5 has the same shape as the first wiring 4 and includes the same structure, dimensions, and materials as the first wiring 4. That is, like the first wiring 4, the second wiring 5 includes a conductor 6 and an insulating layer 7 covering the conductor 6.

[0051] Multiple wirings 2 (first wiring 4 and second wiring 5) are continuous with a magnetic layer 3 described later. That is, a magnetic layer 3 extending in a first direction is disposed between the first wiring 4 and the second wiring 5, and the magnetic layer 3 is in contact with both the first wiring 4 and the second wiring 5.

[0052] The center-to-center distance D1 between the first wiring 4 and the second wiring 5 is, for example, 20 μm or more, preferably 50 μm or more, and also, for example, 3000 μm or less, preferably 2000 μm or less.

[0053] Magnetic layer 3 is a layer used to improve inductance.

[0054] The magnetic layer 3 is configured to cover the entire outer peripheral surface of the plurality of wirings 2. The magnetic layer 3 forms the shape of the inductor 1. Specifically, the magnetic layer 3 has a generally rectangular shape in plan view that extends along the surface direction (first direction and second direction). In addition, the magnetic layer 3 exposes the second-direction edge of the plurality of wirings 2 on its other side in the second direction.

[0055] The magnetic layer 3 is formed from a magnetic composition containing anisotropic magnetic particles 8 and a binder 9.

[0056] As materials constituting the anisotropic magnetic particles (hereinafter, also simply referred to as "particles") 8, soft magnetic materials and hard magnetic materials are examples. From the viewpoint of inductance, soft magnetic materials are preferred.

[0057] Examples of soft magnetic materials include, for instance, a single metallic body containing one metallic element in its pure state, or an alloy body, such as a eutectic mixture (mixture) of one or more metallic elements (first metallic element) and one or more metallic elements (second metallic element) and / or non-metallic elements (carbon, nitrogen, silicon, phosphorus, etc.). These materials can be used alone or in combination.

[0058] As a single metallic substance, an example is a metallic element composed of only one metallic element (the first metallic element). The first metallic element can be appropriately selected from, for example, iron (Fe), cobalt (Co), nickel (Ni), and other metallic elements that can be contained as the first metallic element of a soft magnetic body.

[0059] Furthermore, examples of single metallic bodies include, for instance, a core containing only one metallic element and a surface layer containing partially or completely inorganic and / or organic matter that modifies the surface of the core; organometallic compounds containing the first metallic element; and forms resulting from the decomposition (thermal decomposition, etc.) of inorganic metal compounds. More specifically, examples of the latter include iron powder (sometimes called carbonyl iron powder) resulting from the thermal decomposition of an organoiron compound containing iron as the first metallic element (specifically, carbonyl iron). Furthermore, the location of the layer containing inorganic and / or organic matter that modifies the portion containing only one metallic element is not limited to the surface described above. Moreover, there are no particular limitations on the organometallic compounds or inorganic metal compounds from which single metallic bodies can be obtained; rather, appropriate selections can be made from known or conventional organometallic compounds or inorganic metal compounds that can produce single metallic bodies with soft magnetic properties.

[0060] The alloy body is a fusion of one or more metallic elements (first metallic element) and one or more metallic elements (second metallic element) and / or non-metallic elements (carbon, nitrogen, silicon, phosphorus, etc.). There are no special restrictions as long as the elements can be used as alloy bodies that are soft magnetic bodies.

[0061] The first metallic element is an essential element of the alloy, such as iron (Fe), cobalt (Co), and nickel (Ni). Furthermore, if the first metallic element is Fe, the alloy is an Fe-based alloy; if the first metallic element is Co, the alloy is a Co-based alloy; and if the first metallic element is Ni, the alloy is a Ni-based alloy.

[0062] The second metallic element is an auxiliary element (auxiliary component) contained in the alloy body and is compatible (eutectic) with the first metallic element. Examples include iron (Fe) (when the first metallic element is other than Fe), cobalt (Co) (when the first metallic element is other than Co), nickel (Ni) (when the first metallic element is other than Ni), chromium (Cr), aluminum (Al), silicon (Si), copper (Cu), silver (Ag), manganese (Mn), calcium (Ca), barium (Ba), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), ruthenium (Ru), rhodium (Rh), zinc (Zn), gallium (Ga), indium (In), germanium (Ge), tin (Sn), lead (Pb), scandium (Sc), yttrium (Y), strontium (Sr), and various rare earth elements. These elements can be used alone or in combination of two or more.

[0063] Nonmetallic elements are elements (auxiliary components) that are contained in the alloy body as an auxiliary component, and are compatible (eutectic) with the first metallic element. Examples include boron (B), carbon (C), nitrogen (N), silicon (Si), phosphorus (P), and sulfur (S). These elements can be used alone or in combination of two or more.

[0064] Examples of Fe-based alloys as alloy bodies include, for example, 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 alloys, Fe-Si-Cr-Ni alloys, Fe-Si-Cr alloys, Fe-Si-Al-Ni-Cr alloys, Fe-Ni-Si-Co alloys, Fe-N alloys, Fe-C alloys, Fe-B alloys, Fe-P alloys, ferrites (including stainless steel ferrites, as well as soft magnetic ferrites such as Mn-Mg ferrites, Mn-Zn ferrites, Ni-Zn ferrites, Ni-Zn-Cu ferrites, Cu-Zn ferrites, and Cu-Mg-Zn ferrites), Permingt cobalt-based alloys (Fe-Co alloys), Fe-Co-V alloys, Fe-based amorphous alloys, etc.

[0065] Examples of Co-based alloys include Co-Ta-Zr and cobalt (Co)-based amorphous alloys.

[0066] Examples of Ni-based alloys, such as Ni-Cr alloys, are examples of alloy bodies.

[0067] Among these soft magnetic materials, from the perspective of magnetic properties, alloy materials are preferred, Fe-based alloys are more preferred, and iron-silicon-aluminum (Fe-Si-Al alloys) are even more preferred. Furthermore, as soft magnetic materials, single metallic materials are preferred, single metallic materials containing iron in a pure substance state are more preferred, and elemental iron or iron powder (carbonyl iron powder) are even more preferred.

[0068] Regarding the shape of the particles 8, from an anisotropic viewpoint, examples include flat (plate-like) and needle-like shapes; from the viewpoint of having good relative magnetic permeability in the planar direction (two-dimensional), a flat shape is also an example. Furthermore, in addition to containing anisotropic magnetic particles 8, the magnetic layer 3 may further contain isotropic magnetic particles. The isotropic magnetic particles may also have shapes such as spherical, granular, blocky, or pellet-like. The average particle size of the isotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and also, for example, 200 μm or less, preferably 150 μm or less.

[0069] Furthermore, the flatness ratio (flatness) of the flattened particles 8 is, for example, 8 or more, preferably 15 or more, and also, for example, 500 or less, preferably 450 or less. The flatness ratio is calculated, for example, as the aspect ratio obtained by dividing the average particle size (average length) of the particles 8 (described later) by the average thickness of the particles 8.

[0070] The average particle size (average length) of the particles 8 (anisotropic magnetic particles) is, for example, 3.5 μm or more, preferably 10 μm or more, and also, for example, 200 μm or less, preferably 150 μm or less. If the particles 8 are flat, their average thickness is, for example, 0.1 μm or more, preferably 0.2 μm or more, and also, for example, 3.0 μm or less, preferably 2.5 μm or less.

[0071] Examples of adhesives 9 include thermosetting resins and thermoplastic resins.

[0072] Examples of thermosetting resins include epoxy resins, phenolic resins, melamine resins, thermosetting polyimide resins, unsaturated polyester resins, polyurethane resins, and silicone resins. From the viewpoint of adhesion and heat resistance, epoxy resins and phenolic resins are preferred.

[0073] Examples of thermoplastic resins include, for example, acrylic resins, ethylene-vinyl acetate copolymers, polycarbonate resins, polyamide resins (nylon 6, nylon 66, etc.), thermoplastic polyimide resins, and saturated polyester resins (PET, PBT, etc.). Acrylic resins are preferred.

[0074] As the adhesive 9, a combination of thermosetting resin and thermoplastic resin is preferred. A combination of acrylic resin, epoxy resin and phenolic resin is more preferred. This allows the particles 8 to be more reliably fixed around the wiring 2 in a predetermined orientation and with a high filling rate.

[0075] In addition, depending on the requirements, the magnetic composition may also contain additives such as thermosetting accelerators, inorganic particles, organic particles, and crosslinking agents.

[0076] In the magnetic layer 3, particles 8 are oriented and uniformly disposed within the adhesive 9. The magnetic layer 3 extends from the upper surface (one side in the thickness direction) of the inductor 1 to the lower surface (the other side in the thickness direction). When projected along the planar direction, the magnetic layer 3 includes wiring 2. That is, the upper surface of the magnetic layer 3 is located above the upper end of the wiring 2, and the lower surface of the magnetic layer 3 is located below the lower end of the wiring 2.

[0077] The magnetic layer 3 has a peripheral region 11 and an outer region 12 when viewed in cross-section.

[0078] The peripheral region 11 is located around the wiring 2 and is in contact with the wiring 2. The peripheral region 11 has a generally annular shape in cross-section, sharing a central axis with the wiring 2. More specifically, the peripheral region 11 is a region in the magnetic layer 3 that extends radially outward from the outer peripheral surface of the wiring 2 by a value equivalent to 1.5 times the radius R of the wiring 2 (preferably 1.2 times, more preferably 1 times, further preferably 0.8 times, and particularly preferably 0.5 times).

[0079] The surrounding area 11 is arranged around each of the multiple cablings 2, namely around the first cabling 4 and the second cabling 5.

[0080] The surrounding area 11 has multiple (two) oriented regions 13 and multiple (two) non-oriented regions 14.

[0081] Multiple orientation regions 13 are circumferential orientation regions. That is, in the orientation region 13, the particles 8 are oriented in the circumferential direction (around) of the wiring 2 (first wiring 4 or second wiring 5).

[0082] Multiple orientation regions 13 are arranged opposite to each other on the upper side (on one side of the third direction) and the lower side (on the other side of the third direction) of the wiring 2, separated by the center C1 of the wiring 2. That is, the multiple orientation regions 13 have an upper orientation region 15 arranged on the upper side of the wiring 2 and a lower orientation region 16 arranged on the lower side of the wiring 2. In addition, the center C1 of the wiring 2 is located at the center in the vertical direction between the upper orientation region 15 and the lower orientation region 16.

[0083] In each orientation region 13, the direction in which the relative permeability of the particle 8 is higher (e.g., the surface direction of the particle in the case of a flat anisotropic magnetic particle) is roughly in the same direction as the tangent of the circle centered on the center C1 of the wiring 2.

[0084] More specifically, the case where the angle between the face direction of particle 8 and the tangent of the circle in which particle 8 is located is less than 15 degrees is defined as particle 8 being oriented along the circumferential direction.

[0085] The proportion of the number of particles 8 oriented in the circumferential direction relative to the total number of particles 8 contained in the orientation region 13 is, for example, more than 50%, preferably more than 70%, and more preferably more than 80%. That is, the orientation region 13 may, for example, contain less than 50% of particles 8 that are not oriented in the circumferential direction, preferably less than 30% of particles 8 that are not oriented in the circumferential direction, and more preferably less than 20% of particles 8 that are not oriented in the circumferential direction.

[0086] The ratio of the total area of ​​the multiple orientation regions 13 to the area of ​​the entire surrounding region 11 is, for example, 40% or more, preferably 50% or more, more preferably 60% or more, and for example, 90% or less, preferably 80% or less.

[0087] The relative permeability in the circumferential direction of the orientation region 13 is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and also, for example, 500 or less. The relative permeability in the radial direction is, for example, 1 or more, preferably 5 or more, and also, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. Furthermore, the ratio of the relative permeability in the circumferential direction to the relative permeability in the radial direction (circumferential / radial) is, for example, 2 or more, preferably 5 or more, and also, for example, 50 or less. If the relative permeability is within the above range, the inductance is excellent.

[0088] Relative permeability can be measured, for example, using an impedance analyzer (manufactured by Agilent, “4291B”) equipped with a magnetic material testing device.

[0089] Multiple non-oriented regions 14 are circumferentially non-oriented regions. That is, in non-oriented regions 14, particles 8 are not oriented along the circumferential direction of wiring 2. In other words, in non-oriented regions 14, particles 8 are oriented or unoriented in a direction other than the circumferential direction of wiring 2 (e.g., radial).

[0090] Multiple non-oriented regions 14 are arranged opposite to each other on one side of the first direction and the other side of the first direction of the wiring 2, separated by the wiring 2. That is, the multiple non-oriented regions 14 have a one-sided non-oriented region 17 arranged on one side of the first direction of the wiring 2 (first wiring 4 or second wiring 5) and a other-sided non-oriented region 18 arranged on the other side of the first direction of the wiring 2. The one-sided non-oriented region 17 and the other-sided non-oriented region 18 are approximately linearly symmetrical about a straight line passing through the center C1 in the vertical direction.

[0091] In each non-oriented region 14, the direction in which the relative permeability of particle 8 is higher (e.g., the face direction of the particle in the case of a flat anisotropic magnetic particle) is not aligned with the direction of the tangent to the circle centered at the center C1 of wiring 2. More specifically, a case where the angle between the face direction of particle 8 and the tangent to the circle in which particle 8 is located exceeds 15° is defined as particle 8 not being oriented along the circumferential direction.

[0092] The proportion of the number of particles 8 that are not oriented in the circumferential direction to the total number of particles 8 contained in the non-oriented region 14 is more than 50%, preferably more than 70%, and for example, less than 95%, preferably less than 90%.

[0093] The non-oriented region 14 may also include particles 8 oriented, for example, in a circumferential direction. The number of particles 8 oriented in the circumferential direction is less than 50% of the total number of particles 8 contained in the non-oriented region 14, preferably less than 30%, and in addition, for example, more than 5%, preferably more than 10%.

[0094] Furthermore, in the case of including particles 8 oriented in a circumferential direction, it is preferable that the particles 8 oriented in the circumferential direction are disposed at the innermost side of the non-oriented region 14, i.e., the surface of the wiring 2.

[0095] The ratio of the total area of ​​the plurality of non-oriented regions 14 to the overall area of ​​the surrounding region 11 is, for example, 10% or more, preferably 20% or more, and also, for example, 60% or less, preferably 50% or less, and more preferably 40% or less.

[0096] In the peripheral region 11 (particularly in the regions of the oriented region 13 and the non-oriented region 14), the filling rate of the particles 8 is, for example, 40% by volume or more, preferably 45% by volume or more, and also, for example, 90% by volume or less, preferably 70% by volume or less. If the filling rate is above the aforementioned lower limit, the inductance is excellent.

[0097] The fill rate can be calculated by measuring the actual specific gravity, binarizing the cross-sectional view of the SEM image, etc.

[0098] In the peripheral region 11, multiple oriented regions 13 and multiple non-oriented regions 14 are arranged adjacent to each other in the circumferential direction. Specifically, the upper oriented region 15, one side non-oriented region 17, the lower oriented region 16, and the other side non-oriented region 18 are consecutive in this order in the circumferential direction. Furthermore, the circumferential boundary (one end edge or the other end edge) between the oriented region 13 and the non-oriented region 14 is an imaginary straight line extending radially outward from the center of the wiring 2.

[0099] The outer region 12 is the region in the magnetic layer 3 other than the peripheral region 11. The outer region 12 is disposed outside the peripheral region 11 in a manner that is continuous with the peripheral region 11.

[0100] In the outer region 12, particles 8 are oriented along the surface direction (especially the first direction).

[0101] In the outer region 12, the direction in which the relative permeability of particle 8 is higher (e.g., the face direction of the particle in the case of a flat anisotropic magnetic particle) is approximately aligned with the first direction. More specifically, the case where the angle between the face direction of particle 8 and the first direction is less than 15° is defined as the orientation of particle 8 along the first direction.

[0102] In the outer region 12, the number of particles 8 oriented along the first direction is more than 50% of the total number of particles 8 contained in the outer region 12, preferably more than 70%, and more preferably more than 90%. That is, the outer region 12 may contain less than 50% of particles 8 not oriented along the first direction, preferably less than 30% of particles 8 not oriented along the first direction, and more preferably less than 10% of particles 8 not oriented along the first direction.

[0103] In the outer region 12, the relative permeability in the first direction is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and also, for example, 500 or less. The relative permeability in the vertical direction is, for example, 1 or more, preferably 5 or more, and also, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. Furthermore, the ratio of the relative permeability in the first direction to the relative permeability in the vertical direction (first direction / vertical direction) is, for example, 2 or more, preferably 5 or more, and also, for example, 50 or less. If the relative permeability is within the above range, the inductance is excellent.

[0104] In the outer region 12, the filling rate of particles 8 is, for example, 40% by volume or more, preferably 45% by volume or more, and also, for example, 90% by volume or less, preferably 70% by volume or less. If the filling rate is above the lower limit mentioned above, the inductance is excellent.

[0105] The upper surface of the magnetic layer 3 forms the upper surface of the inductor 1. That is, the upper surface of the inductor 1 is formed by the magnetic layer 3.

[0106] The upper surface of the magnetic layer 3, i.e. the upper surface of the inductor 1, has multiple (two) protrusions 10.

[0107] Multiple protrusions 10 are formed by wirings 2 (4, 5), respectively. When projected along the thickness direction, each protrusion 10 includes the wiring 2. The top view shape of the protrusion 10 is similar to the top view shape of the wiring 2. That is, the protrusion 10 has, for example, a roughly U-shaped top view.

[0108] The protrusion 10 protrudes in an arc shape along the arc shape of the wiring 2 opposite to the upper surface of the inductor 1. Therefore, the protrusion 10 has an arc shape that gently protrudes upwards in a side cross-sectional view. More specifically, the arc shape of the protrusion 10 is an arc shape with a central angle α centered on C1, and the protrusion 10 has an arc shape corresponding to the arc portion of the central angle α of the wiring 2. α is, for example, 15 degrees or more, preferably 30 degrees or more, and also, for example, 150 degrees or less, preferably 90 degrees or less. Particles 8 are also filled inside the protrusion 10.

[0109] On the upper surface of the magnetic layer 3, the vertical distance (height difference) H1 between the uppermost end A1 of the protrusion 10 and the midpoint M1 between the wiring 2 is 5 μm or more, preferably 10 μm or more. Furthermore, the vertical distance H1 is, for example, 50 μm or less, preferably 40 μm or less. If the vertical distance H1 is above or below the aforementioned lower limit, the protrusion 10 is easily identified, and the protrusion 10 can be reliably processed. On the other hand, if the vertical distance H1 is below or below the aforementioned upper limit, the distance for processing the path can be shortened, and the wiring 2 can be reliably exposed.

[0110] The lower surface of the magnetic layer 3 forms the lower surface of the inductor 1. That is, the lower surface of the inductor 1 is formed by the magnetic layer 3.

[0111] The lower surface of the magnetic layer 3, i.e., the lower surface of the inductor 1, is flat. Specifically, on the lower surface of the magnetic layer 3, the vertical distance H2 between the lowermost point A2 in the wiring region A and the midpoint M2 between the wiring 2 is, for example, 30 μm or less, preferably 20 μm or less, and more preferably less than 5 μm. If the vertical distance H2 is below the aforementioned upper limit, the inductor 1 can be mounted on the upper surface of the wiring substrate without tilting it, resulting in excellent mounting performance.

[0112] The wiring region A is the area that overlaps with wiring 2 (first wiring 4 or second wiring 5) when projected along the thickness direction. Midpoints M1 and M2 are both located at the center of the first direction on the straight line connecting the centers (centroids) C1 of two adjacent wirings 2.

[0113] The length T1 of the magnetic layer 3 in the first direction is, for example, 5 mm or more, preferably 10 mm or more, and also, for example, 5000 mm or less, preferably 2000 mm or less.

[0114] The length T2 of the magnetic layer 3 in the second direction is, for example, 5 mm or more, preferably 10 mm or more, and also, for example, 5000 mm or less, preferably 2000 mm or less.

[0115] The vertical length (especially the thickness at the midpoint M1) T3 of the magnetic layer 3 is, for example, 100 μm or more, preferably 200 μm or more, and also, for example, 2000 μm or less, preferably 1000 μm or less.

[0116] The ratio of the thickness (diameter) of the wiring 2 to the vertical length T3 of the magnetic layer 3 (wiring diameter / T3) is, for example, 0.1 or more, preferably 0.2 or more, for example, 0.9 or less, preferably 0.7 or less.

[0117] The ratio of the thickness of the protrusion 10 (the vertical distance from the upper edge of the wiring 2 to A1) to the vertical length T3 of the magnetic layer 3 (i.e., protrusion / T3) is, for example, 0.1 or more, preferably 0.2 or more, for example, 0.9 or less, and preferably 0.7 or less.

[0118] 2. Inductor manufacturing method

[0119] Reference Figure 3 A and Figure 3 B will be used to illustrate one embodiment of the manufacturing method of inductor 1. The manufacturing method of inductor 1 includes, for example, a preparation step, an arrangement step, and a stacking step in sequence.

[0120] In the preparation process, multiple wiring 2 and two anisotropic magnetic sheets 20 are prepared.

[0121] Two anisotropic magnetic sheets 20 are each sheet-like and extend along the surface direction, formed from a magnetic composition. In the anisotropic magnetic sheets 20, the particles 8 are oriented along the surface direction. Preferably, two anisotropic magnetic sheets 20 in a semi-cured state (stage B) are used.

[0122] Examples of such anisotropic magnetic sheets 20 include soft magnetic thermosetting adhesive films and soft magnetic films as described in Japanese Patent Application Publication Nos. 2014-165363 and 2015-92544.

[0123] In the configuration process, such as Figure 3 As shown in Figure A, a plurality of wirings 2 are arranged on the upper surface of an anisotropic magnetic sheet 20, and another anisotropic magnetic sheet 20 is arranged above the plurality of wirings 2 in a manner opposite to one anisotropic magnetic sheet 20.

[0124] Specifically, the lower anisotropic magnetic sheet 21 is placed on a flat upper surface platform 23, and then a plurality of wirings 2 are arranged on the upper surface of the lower anisotropic magnetic sheet 21 at a desired interval in the first direction.

[0125] Next, the upper anisotropic magnetic sheet 22 is arranged opposite to the lower anisotropic magnetic sheet 21 and the upper side of the plurality of wirings 2 at intervals.

[0126] In the lamination process, such as Figure 3 As shown in B, two anisotropic magnetic sheets 20 are stacked by embedding multiple wiring 2.

[0127] Specifically, a flexible pressing member 24 is used to press the upper anisotropic magnetic sheet 22 downwards. That is, the lower surface of the pressing member 24 is brought into contact with the upper surface of the upper anisotropic magnetic sheet 22, and the pressing member 24 is pressed downwards towards the lower anisotropic magnetic sheet 21.

[0128] Thus, the upper anisotropic magnetic sheet 22 is disposed along the wiring 2 on the upper surface of the wiring 2 and the lower anisotropic magnetic sheet 21, resulting in the formation of a protrusion 10 on the upper surface of the inductor 1 due to the wiring 2. That is, the outer periphery shape of the wiring 2 is depicted on the upper surface of the upper anisotropic magnetic sheet 22.

[0129] At this time, with the two anisotropic magnetic sheets 20 in a semi-cured state, by pressing, multiple wires 2 are slightly sunk into the lower anisotropic magnetic sheet 21. In the sunken portion, the particles 8 are oriented along the multiple wires 2. That is, the lower orientation region 16 is formed.

[0130] In addition, the upper anisotropic magnetic sheet 22 covers multiple wirings 2 along multiple wirings 2, the particles 8 of the upper anisotropic magnetic sheet 22 are oriented along multiple wirings 2, and the upper anisotropic magnetic sheet 22 is stacked on the upper surface of the lower anisotropic magnetic sheet 21.

[0131] That is, on the upper side of the wiring 2, an upper orientation region 15 is formed by the upper anisotropic magnetic sheet 22, and on both sides (lateral) of the wiring 2 in the first direction, near the contact between the lower anisotropic magnetic sheet 21 and the upper anisotropic magnetic sheet 22, particles 8 oriented along the lower anisotropic magnetic sheet 21 and the upper anisotropic magnetic sheet 22 collide, resulting in the formation of a non-oriented region 14.

[0132] Furthermore, while the anisotropic magnetic sheet 20 is in a semi-cured state, it is heated. As a result, the anisotropic magnetic sheet 20 becomes cured (stage C). In addition, the contact interface 29 between the two anisotropic magnetic sheets 20 disappears, and the two anisotropic magnetic sheets 20 form a magnetic layer 3.

[0133] Therefore, as Figure 2 As shown, an inductor 1 is obtained, comprising a wiring 2 that is approximately circular in cross-section and a magnetic layer 3 covering the wiring 2. That is, the inductor 1 is formed by stacking multiple (two) anisotropic magnetic sheets 20 with the wiring 2 in between.

[0134] 3. Uses

[0135] Inductor 1 is a component of an electronic device, that is, a component used to manufacture electronic devices. It does not contain electronic components (chips, capacitors, etc.) or wiring boards for mounting electronic components. Instead, it is a device that circulates as a single component and can be used in industry.

[0136] Inductor 1 is monolithically manufactured as needed, including a wiring 2, and then, for example, mounted (assembled) in an electronic device. The electronic device includes a wiring substrate and electronic components (chips, capacitors, etc.) mounted on the wiring substrate, which are not shown. Furthermore, inductor 1 is mounted on the wiring substrate by means of connecting members such as solder, and is electrically connected to other electronic devices, functioning as a passive component such as a coil.

[0137] During installation, inductor 1 is fabricated to allow for conduction with electronic equipment. Specifically, as follows: Figure 4 As shown, multiple openings 30 are formed on the upper part of the inductor 1.

[0138] The opening 30 is formed in such a way that the wire 6 is exposed. Specifically, the opening 30 is generally circular when viewed from above, and has a conical shape when viewed from the side, with the opening area narrowing as it moves downward.

[0139] The first-direction distance (misalignment distance) L between the center (centroid) C1 of the conductor 6 and the first-direction center C2 of the opening 30 is, for example, less than 1 / 2 of the first-direction length (diameter) of the conductor 6, preferably less than 1 / 4. Specifically, the first-direction distance L is, for example, less than 2000 μm, preferably less than 200 μm. If the first-direction distance L is less than or equal to the above upper limit, the conductor 6 can be reliably exposed and conduction is possible.

[0140] Furthermore, in inductor 1, there is an orientation region 13 (circumferential orientation region) around the wiring 2 where particles 8 are oriented along the periphery of the wiring 2. Therefore, the easy magnetization axis of the particles 8 is in the same direction as the magnetic field lines generated around the wiring. Thus, the inductance is good.

[0141] Furthermore, in inductor 1, there is a non-oriented region 14 (circumferential non-oriented region) around the wiring 2 that is not oriented along the circumferential direction of wiring 2. Therefore, the direction of the non-magnetizing axis of particle 8 is the same as that of the magnetic field lines generated around the wiring. As a result, the DC superposition characteristics are good.

[0142] Furthermore, the upper surface of the inductor 1 has a protrusion 10 created by the wiring 2. Therefore, if the protrusion 10 is processed to form a path, the wire 6 can be reliably exposed. Thus, path processing can be reliably achieved with 100% probability.

[0143] In general, in components where wiring is embedded in a roughly circular cross-section, if the location of the passage (opening 30) deviates from the shape of the wiring, the circular wire 6 is not easily exposed during cross-section, thus reducing the yield of the passage processing. However, in this inductor 1, although the cross-sectional shape of the wiring 2 is circular, the wiring 2 is reliably located on the underside of the protrusion 10, thus enabling reliable passage processing.

[0144] Furthermore, multiple wirings 2 are arranged at intervals in the first direction, and these multiple wirings 2 are continuous with a magnetic layer 3 between them. Therefore, a magnetic layer 3 is arranged between the multiple wirings 2. As a result, the amount of magnetic layer 3 increases, and the inductance is further improved.

[0145] Furthermore, the magnetic layer 3 extends continuously from the upper surface to the lower surface of the inductor 1, and both the upper and lower surfaces of the inductor 1 are formed by the magnetic layer 3. According to this inductor 1, the inductor 1 is completely filled with the magnetic layer 3, except for the area where the wiring 2 exists. Therefore, the inductance is excellent.

[0146] 4. Variations

[0147] Reference Figure 5 ,illustrate Figure 1 A- Figure 2 The illustration shows a variation of one embodiment. Furthermore, in the variation, components identical to those in the above embodiment are labeled with the same reference numerals, and their descriptions are omitted.

[0148] exist Figure 1 In the embodiment shown in B, the wiring 2 has a shape that is roughly the letter U when viewed from above, but its shape is not limited and can be set appropriately.

[0149] In addition, Figure 1 A- Figure 1 In the embodiment shown in B, there are two wirings 2, but their number is not limited; for example, they can be set to one or more than three.

[0150] For example, in Figure 5The diagram shows an inductor 1 with one wiring 2. In the protrusion 10, the vertical distance H1 between the uppermost end A1 of the protrusion 10 and a point M′1 located 50 μm away from the uppermost end A1 along the surface direction is 30 μm or less (preferably 20 μm or less, more preferably less than 5 μm). That is, instead of the midpoint M1, the point M′1 located 50 μm away from the uppermost end A1 along the surface direction is set as the reference for the height of the protrusion.

[0151] The lower surface of the magnetic layer 3 is flat, and the reference for this flatness is the same as the reference for the protrusion 10 on the upper surface of the magnetic layer 3. That is, instead of the midpoint M2, the reference is set at a location M′2 50 μm away along the surface direction.

[0152] In addition, Figure 1 A and Figure 1 In the embodiment shown in B, the proportion of anisotropic magnetic particles 8 in the magnetic layer 3 can also be uniform in the magnetic layer 3, and can also be increased or decreased as it moves away from each wiring 2.

[0153] <Second Implementation>

[0154] Reference Figure 6 and Figure 7 This section describes a second embodiment of the inductor of the present invention. Furthermore, in the second embodiment, components identical to those in the first embodiment are labeled with the same reference numerals, and their descriptions are omitted. The second embodiment can also achieve the same effects as the first embodiment. Additionally, variations of the first embodiment can also be applied in the second embodiment.

[0155] In the first embodiment, the cross-sectional shape of the wiring 2 is approximately circular, but it can also be approximately rectangular (including squares and rectangles), approximately elliptical, or approximately irregular. In one embodiment of the second embodiment, as... Figure 6 As shown, the cross-sectional shape of wiring 2 is approximately rectangular, and the cross-sectional shape of protrusion 10 is approximately rectangular.

[0156] Wiring 2 (first wiring 4 and second wiring 5) includes a conductor 6 and an insulating layer 7 covering the conductor 6.

[0157] The conductor 6 is generally rectangular in cross-section, and its length in the first direction is longer than its length in the second direction. The length of the conductor 6 in the first direction is, for example, 30 μm or more, preferably 50 μm or more, and also, for example, 3000 μm or less, preferably 1000 μm or less. The length of the conductor 6 in the second direction is, for example, 5 μm or more, preferably 10 μm or more, and also, for example, 500 μm or less, preferably 300 μm or less.

[0158] The insulating layer 7 has a frame shape that is roughly rectangular in cross-section and shares a central axis (center C1) with the wiring 2.

[0159] The magnetic layer 3 has a peripheral region 11 and an outer region 12 when viewed in cross-section.

[0160] The peripheral region 11 is located around the wiring 2 in a manner that contacts the multiple wiring 2. The peripheral region 11 has a generally rectangular shape in cross-section, sharing a central axis with the wiring 2. More specifically, the peripheral region 11 is a region in the magnetic layer 3 that extends outward from the outer peripheral surface of the wiring 2 by a value equivalent to 1.5 times the average of the longest and shortest lengths ([longest length + shortest length] / 2) from the centroid C1 of the wiring 2 to the outer peripheral surface of the wiring 2.

[0161] The surrounding area 11 has multiple (two) oriented regions 13 and multiple (two) non-oriented regions 14. These regions are the same as regions 13 and 14 in the first embodiment.

[0162] The inductor 1 in the second embodiment is also the same as that in the first embodiment, referring to... Figure 7 As shown, the opening 30 is formed through a passage processing.

[0163] Industrial availability

[0164] The inductor of the present invention can be used, for example, as a passive element such as a voltage conversion component.

[0165] Explanation of reference numerals in the attached figures

[0166] 1. Inductor; 2. Wiring; 3. Magnetic layer; 6. Conductor; 7. Insulating layer; 8. Anisotropic magnetic particles; 10. Protrusion; 13. Orientation region.

Claims

1. An inductor, characterized in that, The inductor has wiring and a magnetic layer covering the wiring. The wiring has conductors and an insulating layer covering the conductors. The magnetic layer contains anisotropic magnetic particles and a binder. In the peripheral region of the wiring, the magnetic layer has an orientation region in which the anisotropic magnetic particles are oriented along the periphery of the wiring. The surrounding area is defined as the region, in cross-section, extending outward from the outer surface of the wiring by a value equivalent to 1.5 times the average of the longest and shortest lengths from the centroid of the wiring to its outer surface. The inductor has a protrusion on one side in the thickness direction caused by the wiring. The wiring is arranged in multiple ways at intervals in an orthogonal direction orthogonal to the thickness direction. The vertical distance between the uppermost end of the protrusion and the midpoint of the wiring in one of the thickness directions of the inductor is greater than 5 μm.

2. The inductor according to claim 1, characterized in that, The plurality of wirings are continuous across the magnetic layer.

3. The inductor according to claim 1, characterized in that, The cross-sectional shape of the wiring is circular.

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