CN113544803A - Inductor - Google Patents

Inductor Download PDF

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Publication number
CN113544803A
CN113544803A CN202080019742.2A CN202080019742A CN113544803A CN 113544803 A CN113544803 A CN 113544803A CN 202080019742 A CN202080019742 A CN 202080019742A CN 113544803 A CN113544803 A CN 113544803A
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China
Prior art keywords
region
wirings
wiring
particles
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CN202080019742.2A
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Chinese (zh)
Inventor
古川佳宏
奥村圭佑
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Nitto Denko Corp
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Nitto Denko Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F17/00—Fixed inductances of the signal type 
    • H01F17/04—Fixed inductances of the signal type  with magnetic core
    • H01F17/06—Fixed inductances of the signal type  with magnetic core with core substantially closed in itself, e.g. toroid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H01F1/28—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder dispersed or suspended in a bonding agent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/2823—Wires
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Soft Magnetic Materials (AREA)

Abstract

The inductor (1) comprises a plurality of wirings (2) and a magnetic layer (3), wherein the plurality of wirings (2) are arranged at intervals in a 1 st direction, each of the plurality of wirings (2) comprises a conductive wire (6) and an insulating layer (7), a 1 st direction orientation region (10) is formed between the plurality of wirings (2) adjacent to each other in a manner of including a virtual line (L2) passing through a center (C1) of the wirings (2), in the 1 st direction orientation region (10), anisotropic magnetic particles (8) are oriented along the 1 st direction, and a distance (N) between the 1 st direction orientation regions (10) is 60% or less of an interval (S) on the 1 st virtual line (L2) between the wirings (2).

Description

Inductor
Technical Field
The present invention relates to an inductor.
Background
It is known that an inductor is mounted on an electronic device or the like and used as a passive element such as a voltage conversion member.
For example, an inductor is proposed, the inductor comprising: a rectangular parallelepiped substrate main body portion formed of a magnetic material; and an internal conductor such as copper embedded in the substrate main body, wherein the cross-sectional shape of the substrate main 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, a magnetic material is covered around a wiring (internal conductor) having a rectangular shape (rectangular parallelepiped shape) in a sectional view.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 10-144526
Disclosure of Invention
Problems to be solved by the invention
In addition, it has been studied to improve inductance of an inductor by using anisotropic magnetic particles such as flat magnetic particles as a magnetic material and orienting the anisotropic magnetic particles around a wiring.
However, in the inductor of patent document 1, since the wiring is rectangular in cross section, a defect that it is difficult to orient the anisotropic magnetic particles around the wiring due to the presence of corners or the like occurs. Therefore, the improvement of the inductance may not be sufficient.
In addition, an inductor including a plurality of wirings is also desired. However, if the inductor includes a plurality of wires, magnetic flux between adjacent wires may affect each other due to anisotropic magnetic particles, and thus a defect (crosstalk) in which noise is generated may occur.
The invention provides an inductor which has good inductance and can inhibit crosstalk.
Means for solving the problems
The present invention [1] provides an inductor comprising a plurality of wirings and a magnetic layer covering the plurality of wirings, wherein the plurality of wirings are arranged at intervals in a 1 st direction, each of the plurality of wirings comprises a conductive wire and an insulating layer covering the conductive wire, the magnetic layer contains anisotropic magnetic particles and a binder, a 1 st direction orientation region is formed between the plurality of wirings adjacent to each other so as to include a virtual line passing through the center of the wirings, the anisotropic magnetic particles are oriented in the 1 st direction orientation region, and the distance of the 1 st direction orientation region is 60% or less of the interval on the virtual line between the wirings.
With this inductor, since it includes a plurality of wirings and a magnetic layer covering the plurality of wirings, anisotropic magnetic particles can be easily oriented in the outer circumferential direction at the peripheries of the plurality of wirings. Therefore, the inductance can be improved.
Further, a 1 st direction alignment region is formed so as to include a virtual line passing through centers of the plurality of wirings, in the 1 st direction alignment region, the anisotropic magnetic particles are aligned along the 1 st direction, and a distance of the 1 st direction alignment region is 60% or less of an interval on the virtual line between the wirings. That is, in the space between the wirings as a path of the magnetic flux flowing in the 1 st direction, the distance of the 1 st direction alignment region is shorter than the distance of the region other than the 1 st direction alignment region. Therefore, the influence of magnetism from one wiring to another wiring can be reduced, and crosstalk can be suppressed.
The present invention [2] is the inductor according to [1], wherein the plurality of wires each have a 1 st region in a periphery thereof, and the anisotropic magnetic particles are oriented in a peripheral direction of the wires in the 1 st region. Therefore, the inductance can be improved.
The present invention [3] is the inductor according to [2], wherein the plurality of wires further have 2 nd regions around the wires, respectively, and the anisotropic magnetic particles are not oriented in the 2 nd region in the outer peripheral direction.
Therefore, the dc superimposition characteristic can be improved.
ADVANTAGEOUS EFFECTS OF INVENTION
The inductor has good inductance and can inhibit crosstalk.
Drawings
Fig. 1A and 1B show an embodiment of an inductor according to the present invention, fig. 1A shows a plan view, and fig. 1B shows a cross-sectional view a-a of fig. 1A.
Fig. 2 is a partially enlarged view of a dotted line portion of fig. 1B.
Fig. 3A and 3B show a manufacturing process of the inductor shown in fig. 1A and 1B, fig. 3A shows a placement process, and fig. 3B shows a lamination process.
Fig. 4 is a cross-sectional view of an actual SEM photograph of the inductor shown in fig. 1A and 1B.
Fig. 5 is a cross-sectional view of a modification of the inductor of the present invention (a mode in which the center of the 2 nd area is located on the 1 st imaginary line).
Detailed Description
In fig. 1A, the left-right direction of the drawing sheet is the 1 st direction, the left side of the drawing sheet is the 1 st direction side, and the right side of the drawing sheet is the 1 st direction side. The vertical direction on the drawing sheet is the 2 nd direction (direction orthogonal to the 1 st direction), the upper side on the drawing sheet is the 2 nd direction side (one direction in the axial direction of the wiring), and the lower side on the drawing sheet is the 2 nd direction side (the other direction in the axial direction of the wiring). The paper thickness direction is the vertical direction (the thickness direction which is the direction orthogonal to the 1 st direction and the 2 nd direction), the paper near side is the upper side (the 3 rd direction side, i.e., the thickness direction side), and the paper depth side is the lower side (the 3 rd direction side, i.e., the thickness direction side). Specifically, directional arrows in the drawings shall control.
< one embodiment >
1. Inductor
An embodiment of an inductor according to the present invention is described with reference to fig. 1A to 2.
As shown in fig. 1A and 1B, the inductor 1 has a substantially rectangular shape in plan view extending in the planar direction (1 st direction and 2 nd direction).
As shown in fig. 1A to 2, the inductor 1 includes a plurality of (two) wirings 2 and a magnetic layer 3.
(Wiring)
The plurality of wirings 2 include a 1 st wiring 4 and a 2 nd wiring 5 arranged at an interval from the 1 st wiring 4 in the width direction (1 st direction).
As shown in fig. 1A and 1B, the 1 st wiring 4 extends in the 2 nd direction in an elongated manner, and has, for example, a substantially U-shape in plan view. As shown in fig. 2, the 1 st wiring 4 has a substantially circular shape in cross section.
The 1 st wiring 4 includes a wire 6 and an insulating layer 7 covering the wire 6.
The lead 6 extends long in the 2 nd direction, and has, for example, a substantially U-shape in plan view. The lead wire 6 has a substantially circular shape in cross section having a common central axis with the 1 st wiring 4.
The material of the wire 6 is, for example, a metal conductor such as copper, silver, gold, aluminum, nickel, or an alloy thereof, and copper is preferable. The lead wire 6 may have a single-layer structure or a multilayer structure in which a surface of a core conductor (e.g., copper) is plated with, for example, nickel.
The radius R1 of the lead 6 is, for example, 25 μm or more, preferably 50 μm or more, and is, for example, 2000 μm or less, preferably 200 μm or less.
The insulating layer 7 is a layer for protecting the wires 6 from chemicals, water, and preventing short-circuiting of the wires 6. The insulating layer 7 is disposed so as to cover the entire outer peripheral surface of the lead wire 6.
The insulating layer 7 has a substantially annular shape in cross section, sharing a central axis (center C1) with the 1 st wiring 4.
Examples of the material of the insulating layer 7 include insulating resins such as polyvinyl formal, polyester, polyesterimide, polyamide (including nylon), polyimide, polyamideimide, and polyurethane. These may be used alone in 1 kind, or two or more kinds may be used in combination.
The insulating layer 7 may be formed of a single layer or a plurality of layers.
The thickness R2 of the insulating layer 7 is substantially uniform at any position in the circumferential direction, and the thickness R2 is, for example, 1 μm or more, preferably 3 μm or more, and is, for example, 100 μm or less, preferably 50 μm or less in the radial direction of the wiring 2.
The ratio (R1/R2) of the radius R1 of the wire 6 to the thickness R2 of the insulating layer 7 is, for example, 1 or more, preferably 10 or more, for example, 200 or less, preferably 100 or less.
The radius (R1+ R2) of the 1 st wiring 4 is, for example, 25 μm or more, preferably 50 μm or more, and is, for example, 2000 μm or less, preferably 200 μm or less.
When the 1 st wiring 4 has a substantially U-shape, the center-to-center distance D2 of the 1 st wiring 4 is the same as the center-to-center distance D1 between the plural wirings 2 described later, and is, for example, 20 μm or more, preferably 50 μm or more, and further, for example, 3000 μm or less, preferably 2000 μm or less.
The 2 nd wiring 5 is the same shape as the 1 st wiring 4, and has the same structure, size, and material as the 1 st wiring 4. That is, the 2 nd wiring 5 includes a lead 6 and an insulating layer 7 covering the lead 6, similarly to the 1 st wiring 4.
The interval S between the 1 st wiring 4 and the 2 nd wiring 5 is the shortest distance between the outer peripheral edge of the 1 st wiring 4 and the outer peripheral edge of the 2 nd wiring 5, that is, the distance on the 1 st imaginary line L2 of the portion of the magnetic layer 3 located between the 1 st wiring 4 and the 2 nd wiring 5. Specifically, the interval S between the wirings 2(4, 5) is, for example, 20 μm or more, preferably 70 μm or more, and is, for example, 2000 μm or less, preferably 1000 μm or less.
The center-to-center distance D1 between the 1 st wiring 4 and the 2 nd wiring 5 is, for example, 20 μm or more, preferably 50 μm or more, and is, for example, 3000 μm or less, preferably 2000 μm or less.
(magnetic layer)
The magnetic layer 3 is a layer for improving inductance.
The magnetic layer 3 is disposed so as to cover the entire outer peripheral surface of the plurality of wires 2. The magnetic layer 3 forms the outer shape of the inductor 1. Specifically, the magnetic layer 3 has a substantially rectangular shape in plan view extending in the planar direction (1 st direction and 2 nd direction). The magnetic layer 3 has its other 2 nd direction side surface exposed at the 2 nd direction end edge of the plurality of wires 2.
The magnetic layer 3 is formed of a magnetic composition containing anisotropic magnetic particles 8 and a binder 9.
Examples of the magnetic material constituting the anisotropic magnetic particles (hereinafter, also simply referred to as "particles") 8 include soft magnetic bodies and hard magnetic bodies. From the viewpoint of inductance, a soft magnetic body is preferably used.
Examples of the soft magnetic material include a single metal material containing 1 metal element in a pure state, and an alloy material which is a eutectic (mixture) of 1 or more metal elements (1 st metal element) and 1 or more metal elements (2 nd metal element) and/or nonmetal elements (carbon, nitrogen, silicon, phosphorus, and the like). They can be used alone or in combination.
As the single metal body, for example, a simple metal composed of only 1 metal element (the 1 st metal element) is exemplified. The 1 st metal element is appropriately selected from, for example, iron (Fe), cobalt (Co), nickel (Ni), and metal elements that can be contained as the 1 st metal element of the soft magnetic body.
Examples of the single metal body include a form having a core containing only 1 metal element and a surface layer containing an inorganic substance and/or an organic substance which modifies part or all of the surface of the core, and forms after decomposition (thermal decomposition or the like) of an organic metal compound containing the 1 st metal element, an inorganic metal compound, and the like. More specifically, the latter form includes iron powder (may be referred to as carbonyl iron powder) obtained by thermally decomposing an organic iron compound (specifically, carbonyl iron) containing iron as the 1 st metal element, and the like. The position of the layer having an inorganic substance and/or organic substance that modifies only a portion containing 1 type of metal element is not limited to the surface described above. The organometallic compound and the inorganic metal compound that can obtain a single metal body are not particularly limited, and can be appropriately selected from known or conventional organometallic compounds and inorganic metal compounds that can obtain a single metal body of a soft magnetic body.
The alloy body is a eutectic of 1 or more metal elements (1 st metal element) and 1 or more metal elements (2 nd metal element) and/or nonmetal elements (carbon, nitrogen, silicon, phosphorus, and the like), and is not particularly limited as long as it can be used as an alloy body of a soft magnetic body.
The 1 st metal element is an essential element in the alloy body, and examples thereof include iron (Fe), cobalt (Co), nickel (Ni), and the like. In addition, if the 1 st metal element is Fe, the alloy body is an Fe-based alloy, if the 1 st metal element is Co, the alloy body is a Co-based alloy, and if the 1 st metal element is Ni, the alloy body is an Ni-based alloy.
The 2 nd metal element is an element (subcomponent) contained In the alloy body as a minor component and is a metal element that is compatible with (Co-melted with) the 1 st metal element, and examples thereof include iron (Fe) (when the 1 st metal element is other than Fe), cobalt (Co) (when the 1 st metal element is other than Co), nickel (Ni) (when the 1 st metal element is other than Ni), chromium (Cr), aluminum (Al), silicon (Si), copper (Cu), silver (Ag), manganese (Mn), calcium (Ca), barium (Ba), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), ruthenium (Ru), rhodium (Rh), zinc (Zn), gallium (Ga), indium (In), germanium (Ge), tin (Sn), lead (Pb), scandium (Sc), yttrium (Y), strontium (Sr), and various rare earth elements. They can be used alone or in combination of two or more.
The nonmetal element is an element (subcomponent) which is contained in the alloy body in a minor proportion and is compatible with (co-melted with) the 1 st metal element, and examples thereof include boron (B), carbon (C), nitrogen (N), silicon (Si), phosphorus (P), and sulfur (S). They can be used alone or in combination of two or more.
Examples of Fe-based alloys as an alloy body include magnetic stainless steel (Fe-Cr-Al-Si alloy) (including electromagnetic stainless steel), ferrosilicon-aluminum alloy (Fe-Si-Al alloy) (including super ferrosilicon-aluminum alloy), permalloy (Fe-Ni alloy), Fe-Ni-Mo alloy, Fe-Ni-Mo-Cu alloy, Fe-Ni-Co alloy, Fe-Cr-Al alloy, Fe-Ni-Cr-Si alloy, copper-silicon alloy (Fe-Cu-Si alloy), Fe-Si alloy, Fe-Si-B (-Cu-Nb) alloy, Fe-B-Si-Cr alloy, Fe-Si-Cr-Ni alloy, Fe-Cr-Si-Si alloy, Fe-Si-Si alloy, Fe-Si-alloy, alloys, and alloys, Fe-Si-Cr alloy, Fe-Si-Al-Ni-Cr alloy, Fe-Ni-Si-Co alloy, Fe-N alloy, Fe-C alloy, Fe-B alloy, Fe-P alloy, ferrite (including stainless steel ferrite, and soft ferrite such as Mn-Mg ferrite, Mn-Zn ferrite, Ni-Zn-Cu ferrite, Cu-Zn ferrite, Cu-Mg-Zn ferrite), Permitron-Fe-Co-based high-permeability alloy (Fe-Co alloy), Fe-Co-V alloy, Fe-based amorphous alloy, etc.
Examples of the Co-based alloy as an alloy body include Co-Ta-Zr and a cobalt (Co) -based amorphous alloy.
Examples of the Ni-based alloy as an alloy body include Ni — Cr alloys and the like.
Among these soft magnetic materials, an alloy body is preferable from the viewpoint of magnetic properties, an Fe-based alloy is more preferable, and an iron-silicon-aluminum alloy (Fe — Si — Al alloy) is further preferable. In addition, the soft magnetic material preferably includes a single metal body, more preferably a single metal body containing an iron element in a pure state, and further preferably a simple iron substance or an iron powder (carbonyl iron powder).
The shape of the particles 8 is, for example, a flat shape (plate shape), a needle shape, or the like from the viewpoint of anisotropy, and a flat shape from the viewpoint of good relative magnetic permeability in the planar direction (two-dimensional). In addition, the magnetic layer 3 may further contain isotropic magnetic particles in addition to the anisotropic magnetic particles 8. The isotropic magnetic particles may have a shape such as a sphere, a granule, a block, a pellet, or the like. The average particle diameter of the isotropic magnetic particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, and is, for example, 200 μm or less, preferably 150 μm or less.
The flat particles 8 have a flatness ratio (flatness) of, for example, 8 or more, preferably 15 or more, and further, for example, 500 or less, preferably 450 or less. The flattening ratio is calculated as, for example, a ratio of the average particle diameter (average length) (described later) of the particles 8 to the average thickness of the particles 8.
The average particle diameter (average length) of the particles 8 (anisotropic magnetic particles) is, for example, 3.5 μm or more, preferably 10 μm or more, and is, for example, 200 μm or less, preferably 150 μm or less. When the particles 8 are flat, the average thickness thereof is, for example, 0.1 μm or more, preferably 0.2 μm or more, and is, for example, 3.0 μm or less, preferably 2.5 μm or less.
Examples of the binder 9 include thermosetting resins and thermoplastic resins.
Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin, thermosetting polyimide resin, unsaturated polyester resin, polyurethane resin, and silicone resin. From the viewpoint of adhesiveness, heat resistance, and the like, epoxy resins and phenol resins are preferably used.
Examples of the thermoplastic resin include acrylic resins, ethylene-vinyl acetate copolymers, polycarbonate resins, polyamide resins (nylon 6, nylon 66, and the like), thermoplastic polyimide resins, saturated polyester resins (PET, PBT, and the like), and the like. Acrylic resins are preferred.
The binder 9 is preferably a combination of a thermosetting resin and a thermoplastic resin. More preferably, acrylic resin, epoxy resin and phenol resin are used in combination. This makes it possible to fix the particles 8 more reliably to the periphery of the wiring 2 in a predetermined orientation state and at a high filling rate.
The magnetic composition may further contain additives such as a thermosetting catalyst, inorganic particles, organic particles, and a crosslinking agent, if necessary.
In the magnetic layer 3, the particles 8 are aligned and uniformly arranged in the binder 9.
In cross section, the magnetic layer 3 has a peripheral region 11 and an outer region 12.
The peripheral region 11 is a peripheral region of the wirings 2, and is located around the wirings 2 so as to be in contact with the wirings 2. The peripheral region 11 has a substantially annular shape in cross section having a common central axis with the wiring 2. More specifically, the peripheral region 11 is a region of the magnetic layer 3 that has advanced radially outward from the outer peripheral surface of the wiring 2 by a value (preferably a value 1.2 times, more preferably a value 1 times, further preferably a value 0.8 times, and particularly preferably a value 0.5 times) that is equivalent to 1.5 times the radius of the wiring 2 (the average value of the distances from the center (center of gravity) C1 of the wiring 2 to the outer peripheral surface; R1+ R2).
The peripheral region 11 is disposed around each of the plurality of wirings 2, that is, around the 1 st wiring 4 and around the 2 nd wiring 5.
The peripheral region 11 includes a plurality (two) of the 1 st regions 13 and a plurality (two) of the 2 nd regions 14.
The plurality of 1 st regions 13 are circumferentially oriented regions. That is, in the 1 st region 13, the particles 8 are oriented along the circumferential direction (outer circumferential direction) of the wiring 2 (the 1 st wiring 4 or the 2 nd wiring 5).
The plurality of 1 st regions 13 are disposed on the upper side (one side in the 3 rd direction) and the lower side (the other side in the 3 rd direction) of the wiring 2 so as to face each other with the center C1 of the wiring 2 interposed therebetween. That is, the plurality of 1 st regions 13 include an upper 1 st region 15 disposed above the wiring 2 and a lower 1 st region 16 disposed below the wiring 2. Further, the center C1 of the wiring 2 is located at the center in the vertical direction between the upper 1 st region 15 and the lower 1 st region 16.
In each 1 st region 13, the direction in which the relative permeability of the particles 8 is high (for example, in the case of flat anisotropic magnetic particles, the plane direction of the particles) substantially coincides with the tangent line of a circle centered on the center C1 of the wire 2.
More specifically, the case where the angle formed by the plane direction of the particle 8 and the tangent of the circle on which the particle 8 is located is 15 degrees or less is defined as the orientation of the particle 8 in the circumferential direction.
The ratio of the number of the particles 8 oriented in the circumferential direction to the number of the particles 8 as a whole contained in the 1 st region 13 is, for example, more than 50%, preferably 70% or more, and more preferably 80% or more. That is, in the 1 st region 13, for example, less than 50% of the particles 8 not oriented in the circumferential direction may be contained, 30% or less of the particles 8 not oriented in the circumferential direction may be contained, and 20% or less of the particles 8 not oriented in the circumferential direction may be contained. The ratio of the total area of the plurality of 1 st regions 13 to the area of the entire peripheral region 11 is, for example, 40% or more, preferably 50% or more, more preferably 60% or more, and is, for example, 90% or less, preferably 80% or less.
The relative permeability in the circumferential direction of the 1 st region 13 is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and further, for example, 500 or less. The relative permeability in the radial direction is, for example, 1 or more, preferably 5 or more, and further, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. The ratio of the relative permeability in the circumferential direction to the relative permeability in the radial direction (circumferential direction/radial direction) is, for example, 2 or more, preferably 5 or more, and, for example, 50 or less. When the relative permeability is within the above range, the inductance is excellent.
The relative permeability can be measured, for example, by using an impedance analyzer (manufactured by Agilent corporation, "4291B") having a magnetic material test jig.
The plurality of 2 nd regions 14 are circumferential non-oriented regions. That is, in the 2 nd region 14, the particles 8 are not oriented in the circumferential direction (outer circumferential direction) of the wiring 2. In other words, in the 2 nd region 14, the particles 8 are oriented or not oriented in a direction other than the circumferential direction of the wiring 2 (for example, the 1 st direction, the radial direction).
The plurality of 2 nd regions 14 are arranged on one side in the 1 st direction and the other side in the 1 st direction of the wiring 2 so as to face each other with the wiring 2 interposed therebetween. That is, the plurality of 2 nd regions 14 include one 2 nd region 17 disposed on one side in the 1 st direction of the wiring 2 (the 1 st wiring 4 or the 2 nd wiring 5) and the other 2 nd region 18 disposed on the other side in the 1 st direction of the wiring 2. The one side 2 nd region 17 and the other side 2 nd region 18 are substantially line-symmetrical with respect to the 2 nd imaginary line L3.
The 2 nd virtual line L3 is a straight line passing through the center C1 of the 1 st wiring 4 or the 2 nd wiring and extending in the vertical direction.
In each 2 nd region 14, the direction in which the relative permeability of the particles 8 is high (for example, in the case of flat anisotropic magnetic particles, the plane direction of the particles) does not coincide with the tangent of a circle centered on the center C1 of the wire 2.
More specifically, a case where the angle formed by the plane direction of the particle 8 and the tangent of the circle in which the particle 8 is located exceeds 15 degrees is defined as a case where the particle 8 is not oriented in the circumferential direction.
The ratio of the number of particles 8 that are not oriented in the circumferential direction to the number of the entire particles 8 included in the 2 nd region 14 is more than 50%, preferably 70% or more, and for example, 95% or less, preferably 90% or less.
In the 2 nd region 14, for example, the particles 8 oriented in the circumferential direction may be contained. The ratio of the number of the particles 8 oriented in the circumferential direction to the number of the entire particles 8 included in the 2 nd region 14 is less than 50%, preferably 30% or less, and for example, 5% or more, preferably 10% or more.
When the particles 8 oriented in the circumferential direction are included, the particles 8 oriented in the circumferential direction are preferably disposed on the innermost side of the 2 nd region 14, that is, on the surface of the wiring 2.
The ratio of the total area of the plurality of 2 nd regions 14 to the area of the entire peripheral region 11 is, for example, 10% or more, preferably 20% or more, and is, for example, 60% or less, preferably 50% or less, and more preferably 40% or less.
The center C2 of the 2 nd region 14 does not exist on the 1 st imaginary line L2. That is, the center C2 is located on the lower side with respect to the 1 st virtual line L2, the center C2 is preferably located at a position below the 1 st virtual line L2 by an amount equivalent to 0.1 times the radius R, and the center C2 is more preferably located at a position below the 1 st virtual line L2 by an amount equivalent to 0.3 times the radius R. More specifically, the center C2 is preferably located 10 μm below the 1 st imaginary line L2, and more preferably 30 μm below the 1 st imaginary line L2.
In addition, the center C2 of the 2 nd region 14 is located between the 1 st imaginary line L2 and the 2 nd imaginary line L3. That is, the center C2 of the 2 nd region 14 does not exist on any one of the 1 st imaginary line L2 and the 2 nd imaginary line L3.
The center C2 of the 2 nd region 14 is the center of a virtual arc L1 that connects one end in the circumferential direction and the other end in the circumferential direction in the 2 nd region 14. More specifically, the center C2 of the 2 nd region 14 is the center of a virtual arc L1 that connects the radial center of one circumferential end edge and the radial center of the other circumferential end edge in the 2 nd region 14.
The 1 st imaginary line L2 is a straight line passing through the centers C1 of the plurality of wirings 2 adjacent to each other and extending in the 1 st direction.
In the 2 nd region 14, an intersection (top) 19 is formed by at least two kinds of particles 8 having different orientation directions. That is, the particles 8 (1 st particles) which are located relatively on the upper side in the 2 nd region 14 and which become oriented in the 1 st direction from the orientation in the circumferential direction as going toward the lower end side of the 2 nd region 14 in the circumferential direction of the wiring 2 and the particles 8 (2 nd particles) which are located relatively on the lower side (lower side than the 1 st particles) in the 2 nd region 14 and which become oriented in the 1 st direction from the orientation in the circumferential direction as going toward the upper end side of the 2 nd region 14 in the circumferential direction constitute at least two sides of a substantially triangular shape, thereby forming the intersection 19. Specifically, the 1 st particle and the 2 nd particle form a substantially triangular shape (preferably, an acute triangular shape) together with the particle 8 (the 3 rd particle) oriented in the circumferential direction inside the 2 nd region 14.
The intersection 19 does not exist on the 1 st imaginary line L2 passing through the centers of the 1 st wiring 4 and the 2 nd wiring 5 between them. That is, the intersection 19 is disposed below the 1 st virtual line L2 at a position spaced from the virtual arc L1. More specifically, the angle θ formed by the straight line connecting the center of the intersection 19 and the center C1 of the wiring 2 and the 1 st virtual line L2 is, for example, 15 ° or more, preferably 45 ° or more, and is, for example, 75 ° or less, preferably 60 ° or less.
In the peripheral region 11 (particularly, in each of the 1 st region 13 and the 2 nd region 14), the filling rate of the particles 8 is, for example, 40 vol% or more, preferably 45 vol% or more, and is, for example, 90 vol% or less, preferably 70 vol% or less. When the filling ratio is not less than the lower limit, the inductance is excellent.
The filling ratio can be calculated by measuring the actual specific gravity, binarizing the sectional view of the SEM photograph, and the like.
In the peripheral region 11, the plurality of 1 st regions 13 and the plurality of 2 nd regions 14 are arranged adjacent to each other in the circumferential direction. Specifically, the upper 1 st region 15, the one 2 nd region 17, the lower 1 st region 16, and the other 2 nd region 18 are continuous in this order in the circumferential direction.
The boundary (one end or the other end) in the circumferential direction between the 1 st region 13 and the 2 nd region 14 is an imaginary straight line extending radially outward from the center of the wiring 2.
The outer region 12 is a region of the magnetic layer 3 other than the peripheral region 11. The outer region 12 is disposed outside the peripheral region 11 so as to be continuous with the peripheral region 11.
In the outer region 12, the particles 8 are oriented in the in-plane direction (particularly the 1 st direction).
In the outer region 12, the direction in which the relative permeability of the particles 8 is high (for example, in the case of flat anisotropic magnetic particles, the plane direction of the particles) substantially coincides with the 1 st direction. More specifically, the case where the angle formed by the plane direction of the particle 8 and the 1 st direction is 15 ° or less is defined as the orientation of the particle 8 in the 1 st direction.
In the outer region 12, the ratio of the number of particles 8 oriented in the 1 st direction to the total number of particles 8 contained in the outer region 12 exceeds 50%, preferably 70% or more, and more preferably 90% or more. That is, in the outer region 12, less than 50% of the particles 8 not oriented in the 1 st direction may be contained, 30% or less of the particles 8 not oriented in the 1 st direction may be contained, and 10% or less of the particles 8 not oriented in the 1 st direction may be contained.
In the outer region 12, the relative permeability in the 1 st direction is, for example, 5 or more, preferably 10 or more, more preferably 30 or more, and further, for example, 500 or less. The relative permeability in the vertical direction is, for example, 1 or more, preferably 5 or more, and further, for example, 100 or less, preferably 50 or less, and more preferably 25 or less. The ratio of the relative permeability in the 1 st direction to the relative permeability in the up-down direction (1 st direction/up-down direction) is, for example, 2 or more, preferably 5 or more, and, for example, 50 or less. When the relative permeability is within the above range, the inductance is excellent.
In the outer region 12, the filling rate of the particles 8 is, for example, 40 vol% or more, preferably 45 vol% or more, and is, for example, 90 vol% or less, preferably 70 vol% or less. When the filling ratio is not less than the lower limit, the inductance is excellent.
In addition, in a region between the plurality of wirings 2 including the peripheral region 11 and the outer region 12, a 1 st direction alignment region 10 including a 1 st virtual line L2 is formed. That is, in a cross section of the inductor 1 cut along the 1 st direction and the up-down direction, the 1 st direction alignment region 10 is located between the plurality of wirings 2 and includes the 1 st virtual line L2. Specifically, the 1 st direction orientation region 10 is a region having a length of 40% (preferably 50 μm) of the radius R1 of the conductive wire 6 in the up-down direction around the 1 st virtual line L2 at the up-down direction position, and is a region in which the particles 8 are oriented in the 1 st direction.
The ratio of the number of particles 8 oriented in the 1 st direction to the number of the entire particles 8 included in the 1 st direction orientation region 10 is, for example, 85% or more, preferably 90% or more, and more preferably 95% or more. That is, in the 1 st direction orientation region 10, for example, 15% or less of the particles 8 not oriented in the 1 st direction may be contained, preferably 10% or less of the particles 8 not oriented in the 1 st direction may be contained, and more preferably 5% or less of the particles 8 not oriented in the 1 st direction may be contained.
Further, in a region adjacent to the 1 st direction one side and the 1 st direction other side of the 1 st direction alignment region 10, the particles 8 are not aligned in the 1 st direction.
The 1 st direction distance N of the 1 st direction alignment region 10 is, for example, 500 μm or less, preferably 400 μm or less, more preferably 300 μm or less, and is, for example, 10 μm or more, preferably 40 μm or more.
The 1 st direction distance N of the 1 st direction alignment region 10 is 60% or less, preferably 50% or less, more preferably 30% or less, and further, for example, 5% or more with respect to the interval S between wirings. When the ratio (N/S × 100%) is equal to or less than the upper limit, crosstalk between the wirings 2 can be suppressed.
Length T of magnetic layer 3 in direction 11For example, 5mm or more, preferably 10mm or more, and for example, 5000mm or less, preferably 2000mm or less.
Length T of magnetic layer 3 in direction 22For example, 5mm or more, preferably 10mm or more, and for example, 5000mm or less, preferably 2000mm or less.
Length (thickness) T in vertical direction of magnetic layer 33For example, 100 μm or more, preferably 200 μm or more, and for example, 2000 μm or less, preferably 1000 μm or less.
2. Method for manufacturing inductor
One embodiment of a method for manufacturing the inductor 1 is described with reference to fig. 3A and 3B. The method for manufacturing the inductor 1 includes, for example, a preparation step, a placement step, and a lamination step in this order.
In the preparation step, the plurality of wirings 2 and the two anisotropic magnetic sheets 20 are prepared.
Each of the two anisotropic magnetic sheets 20 has a sheet shape extending in the planar direction and is formed of a magnetic composition. In the anisotropic magnetic sheet 20, the particles 8 are oriented in the plane direction. Preferably, two anisotropic magnetic sheets 20 in a semi-cured state (B-stage) are used.
Examples of such anisotropic magnetic sheets 20 include soft magnetic thermosetting adhesive films and soft magnetic films described in japanese patent application laid-open nos. 2014-165363 and 2015-92544.
In the arranging step, as shown in fig. 3A, a plurality of wirings 2 are arranged on the upper surface of one anisotropic magnetic sheet 20, and another anisotropic magnetic sheet 20 is arranged to face above the plurality of wirings 2.
Specifically, the lower anisotropic magnetic sheet 21 is placed on a horizontal table, and then the plurality of wires 2 are arranged on the upper surface of the lower anisotropic magnetic sheet 21 at a desired interval in the 1 st direction.
Next, the upper anisotropic magnetic sheet 22 is disposed on the upper side of the lower anisotropic magnetic sheet 21 and on the upper side of the plurality of wires 2 in a manner spaced apart from each other.
In the lamination step, as shown in fig. 3B, two anisotropic magnetic sheets 20 are laminated so that a plurality of wirings 2 are buried.
Specifically, the upper anisotropic magnetic sheet 22 is pressed downward.
At this time, when the two anisotropic magnetic sheets 20 are in the semi-cured state, the plurality of wirings 2 are slightly sunk into the lower anisotropic magnetic sheet 21 by pressing, and the grains 8 are oriented along the plurality of wirings 2 in the sunk portions. I.e. the lower 1 st region 16 is formed.
In addition, the upper anisotropic magnetic sheet 22 covers the plurality of wirings 2 along the plurality of wirings 2, the grains 8 of the upper anisotropic magnetic sheet 22 are oriented along the plurality of wirings 2, and the upper anisotropic magnetic sheet 22 is laminated on the upper surface of the lower anisotropic magnetic sheet 21.
That is, the upper 1 st region 15 is formed by the upper anisotropic magnetic sheet 22 on the upper side of the wiring 2, and the particles 8 oriented in the lower anisotropic magnetic sheet 21 and the upper anisotropic magnetic sheet 22 collide with each other on both sides (sides) in the 1 st direction of the wiring 2 in the vicinity of the portion where the lower anisotropic magnetic sheet 21 and the upper anisotropic magnetic sheet 22 contact each other, and as a result, the 2 nd region 14 and the intersection 19 are formed.
When the anisotropic magnetic sheet 20 is in a semi-cured state, heating is performed. Thereby, the anisotropic magnetic sheet 20 is in a cured state (C stage). In addition, the contact interface 25 between the two anisotropic magnetic sheets 20 disappears, and the two anisotropic magnetic sheets 20 form one magnetic layer 3.
As a result, as shown in fig. 2, an inductor 1 including a wiring 2 having a substantially circular shape in cross section and a magnetic layer 3 covering the wiring 2 is obtained. That is, the inductor 1 is formed by laminating a plurality of (two) anisotropic magnetic sheets 20 so as to sandwich the wiring 2. Fig. 4 shows a cross-sectional view (SEM photograph) of an example of an actual inductor 1.
3. Use of
The inductor 1 is a component of an electronic device, that is, a component for manufacturing an electronic device, does not include an electronic component (a chip, a capacitor, or the like) or a mounting board on which an electronic component is mounted, and is a device that is distributed as a single component and is industrially applicable.
The inductor 1 is mounted (assembled) on, for example, an electronic device or the like. The electronic device includes a mounting substrate and an electronic component (chip, capacitor, or the like) mounted on the mounting substrate, but this case is not illustrated. The inductor 1 is mounted on a mounting board via a connecting member such as solder, is electrically connected to other electronic devices, and functions as a passive element such as a coil.
Thus, with the inductor 1, since the plurality of wirings 2 and the magnetic layer 3 covering the plurality of wirings 2 are included, the particles 8 can be easily oriented in the circumferential direction at the periphery of the plurality of wirings 2. Therefore, the magnetization easy axis of the grains 8 is the same as the direction of the magnetic lines generated around the wiring, whereby the inductance can be improved.
Further, a 1 st direction alignment region 10 is formed so as to overlap the 1 st virtual line L2, the particles 8 are aligned in the 1 st direction alignment region 10, and a distance N in the 1 st direction of the 1 st direction alignment region 10 is 50% or less of the interval S on the 1 st virtual line L2 between the wirings 2. That is, in the space between the wirings 2, which is a path of the magnetic flux flowing in the 1 st direction, the distance N of the 1 st direction alignment region 10 is shorter than the distance of the regions other than the 1 st direction alignment region 10 (i.e., the regions on both sides of the 1 st direction alignment region 10 where the particles 8 are not aligned in the 1 st direction). Therefore, the influence of magnetism from one wiring 2 (the 1 st wiring 4 or the 2 nd wiring 5) to the other wiring (the 2 nd wiring 5 or the 1 st wiring 4) can be reduced, and crosstalk can be suppressed.
In the inductor 1, the 1 st region 13, which is a circumferential direction orientation region, is provided in each of the peripheral regions 11 of the plurality of wires 2. Therefore, the inductance can be improved.
In the inductor 1, the 2 nd regions 14, which are non-oriented regions in the circumferential direction, are provided in the peripheral regions 11 of the plurality of wires 2. Therefore, the hard axis of magnetization of the grains 8 is the same as the direction of the magnetic lines generated around the wiring, and therefore the dc superposition characteristic is good.
In addition, the center C2 in the 2 nd region 14 does not exist on the 1 st imaginary line L2. Therefore, the distance of the magnetic flux from the 1 st wiring 4 to the 2 nd wiring 5 via the 2 nd region 14 can be extended. That is, the distance through which the magnetic flux passes between the wirings 2 can be substantially extended.
Therefore, the influence of magnetism from the 1 st wiring 4 to the 2 nd wiring 5 can be reduced, and crosstalk can be further suppressed.
< modification example >
Next, a modification of the embodiment shown in fig. 1A to 2 will be described. In the modification, the same members as those of the above-described one embodiment are denoted by the same reference numerals, and the description thereof is omitted.
These modifications also have the same operational effects as the above-described one embodiment and the like.
In the embodiment shown in fig. 2, the center C2 in the 2 nd region 14 does not exist on the 1 st imaginary line L2, but, for example, as shown in fig. 5, the center C2 in the 2 nd region 14 may exist on the 1 st imaginary line L2.
That is, the embodiment shown in fig. 5 is substantially line-symmetrical with respect to the 1 st imaginary line L2.
From the viewpoint of further reducing crosstalk, the embodiments shown in fig. 1A to 2 are preferable.
In the embodiment shown in fig. 2, the wiring 2 has a substantially circular shape in cross section, but the cross sectional shape is not particularly limited, and may be, for example, a substantially elliptical shape, a substantially rectangular shape (including a square and a rectangle), or a substantially irregular shape, although this is not shown. The wiring 2 may have a substantially rectangular shape, and may be bent at least at 1 side or at least at 1 corner.
In any of the above embodiments, the peripheral region 11 is a region that advances outward from the outer peripheral surface of the wiring 2 in cross section by a value corresponding to 1.5 times the average value of the longest length and the shortest length from the center of gravity C1 of the wiring 2 to the outer peripheral surface of the wiring 2 ([ longest length + shortest length ]/2).
In the embodiment shown in fig. 1A and 1B, two wires 2 are provided, but the number thereof is not limited, and 3 or more wires 2 may be provided.
In the embodiment shown in fig. 1A and 1B, each of the wirings 2 has a substantially U-shape in plan view, but the shape thereof is not limited and can be set as appropriate.
In the embodiment shown in fig. 1A and 1B, the magnetic layer 3 can also have alignment marks.
In the embodiment shown in fig. 1A and 1B, the ratio of the anisotropic magnetic particles 8 in the magnetic layer 3 may be uniform in the magnetic layer 3, or may be higher or lower as the distance from each wiring 2 increases.
Industrial applicability
The inductor of the present invention can be used as a passive element such as a voltage conversion member.
Description of the reference numerals
1. An inductor; 2. wiring; 3. a magnetic layer; 6. a wire; 7. an insulating layer; 8. anisotropic magnetic particles; 10. a 1 st direction orientation region; 13. region 1; 14. a 2 nd region; c1, center of wiring; c2, center of imaginary arc; l2, 1 st imaginary line.

Claims (3)

1. An inductor, characterized in that it comprises a first inductor,
the inductor includes a plurality of wirings and a magnetic layer covering the plurality of wirings,
the plurality of wirings are arranged at intervals from each other in the 1 st direction,
the plurality of wirings each include a conductive line and an insulating layer covering the conductive line,
the magnetic layer contains anisotropic magnetic particles and a binder,
a 1 st direction alignment region in which the anisotropic magnetic particles are aligned in the 1 st direction is formed between the plurality of wirings adjacent to each other so as to include an imaginary line passing through centers of the wirings,
the distance of the 1 st direction alignment region is 60% or less of the interval on the virtual line between the wirings.
2. The inductor according to claim 1,
the plurality of wires have 1 st regions around them, respectively, and the anisotropic magnetic particles are oriented in the 1 st region along the outer peripheral direction of the wires.
3. The inductor according to claim 2,
there are also 2 nd regions respectively around the plurality of wirings, in which 2 nd regions the anisotropic magnetic particles are not oriented in the outer circumferential direction.
CN202080019742.2A 2019-03-12 2020-02-05 Inductor Pending CN113544803A (en)

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JPH10144526A (en) 1996-11-05 1998-05-29 Murata Mfg Co Ltd Laminated chip inductor
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JP2001185421A (en) * 1998-12-28 2001-07-06 Matsushita Electric Ind Co Ltd Magnetic device and manufacuring method thereof
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