inductor component

Abstract

Provided is an inductor component capable of suppressing short-circuit between external terminals while suppressing reduction in strength of a green body and reduction in inductance. The inductor component includes: a green body containing a magnetic powder and having a first main surface and a second main surface; an inductor wiring provided inside the green body; a first vertical wiring provided inside the green body, connected to a first end portion of the inductor wiring, and extending to the first main surface; a second vertical wiring provided inside the green body, connected to a second end portion of the inductor wiring, and extending to the first main surface; a first external terminal connected to the first vertical wiring and exposed at the first main surface; and a second external terminal connected to the second vertical wiring and exposed at the first main surface. The magnetic powder has Fe as a main component, and the first main surface has a plurality of oxidation regions in which oxidation films of the magnetic powder are exposed and a plurality of non-oxidation regions in which the magnetic powder is exposed.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an inductor component. BACKGROUND

[0002] In the past, as an inductor component, there has been an inductor component described in Japanese Patent Application Publication No. 2020-145399 (Patent Literature 1). The inductor component includes a green body containing a metal magnetic powder, first and second coil portions disposed inside the green body, a first external electrode electrically connected to one end of the first coil portion, and a second external electrode electrically connected to one end of the second coil portion. Further, the inductor component includes an insulating layer formed by oxidizing the metal magnetic powder on the entire surface of the green body, and the insulating layer prevents short circuit between the inductor component and other electronic components.

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2020-145399 SUMMARY

[0004] However, it is known that the inductor component described above has the following problems.

[0005] There is a problem that the adhesion between the green body and the metal magnetic powder is weakened due to expansion of the oxidized metal magnetic powder, and the strength of the green body is reduced. In addition, there is a problem that the number of metal magnetic powders is reduced due to the metal magnetic powder being detached from the green body, and the inductance is reduced.

[0006] Therefore, the present disclosure aims to provide an inductor component capable of suppressing short circuit between external terminals, while suppressing reduction in the strength of the green body and reduction in the inductance.

[0007] In order to solve the above problems, an inductor component according to one embodiment of the present disclosure includes:

[0008] a green body containing a magnetic powder, having a first main surface and a second main surface;

[0009] an inductor wiring provided inside the green body;

[0010] a first vertical wiring provided inside the green body, connected to a first end portion of the inductor wiring and extending to the first main surface;

[0011] a second vertical wiring provided inside the green body, connected to a second end portion of the inductor wiring and extending to the first main surface;

[0012] a first external terminal connected to the first vertical wiring and exposed on the first main surface; and

[0013] a second external terminal connected to the second vertical wiring and exposed on the first main surface;

[0014] The magnetic powder described above has Fe as a main component,

[0015] The first main surface has a plurality of oxidation regions in which the oxidation film of the magnetic powder described above is exposed, and a plurality of non-oxidation regions in which the magnetic powder described above is exposed.

[0016] Here, the oxidation region refers to a region in which the Fe content is 65 wt% or more and the O content is 24 wt% or more, and the non-oxidation region refers to a region in which the Fe content is 65 wt% or more and the O content is less than 24 wt%.

[0017] According to the embodiment described above, the oxidation region can suppress a short circuit between the first external terminal and the second external terminal via the magnetic powder of the first main surface, and the non-oxidation region can suppress a decrease in the strength of the green body and a decrease in the inductance.

[0018] Preferably, in one embodiment of the inductor component,

[0019] The green body described above contains a resin containing the magnetic powder described above,

[0020] The magnetic powder of the oxidation region described above contains magnetic powder that is in contact with the resin described above via the oxidation film described above.

[0021] According to the embodiment described above, the magnetic powder of the oxidation region is in contact with the resin via the oxidation film, and thus a short circuit can be more effectively suppressed.

[0022] Preferably, in one embodiment of the inductor component,

[0023] The green body described above contains a resin containing the magnetic powder described above,

[0024] The magnetic powder of the oxidation region described above contains magnetic powder that is in direct contact with the resin described above.

[0025] According to the embodiment described above, since the magnetic powder of the oxidation region is in direct contact with the resin, the adhesion of the magnetic powder to the resin is improved, and a decrease in the strength of the green body and a decrease in the inductance can be more effectively suppressed.

[0026] Preferably, in one embodiment of the inductor component, the proportion of the reflectance of a wavelength of 600 nm or more and less than 800 nm to the reflectance of a wavelength of less than 600 nm is larger in the oxidation region than in the non-oxidation region.

[0027] According to the embodiment described above, the oxidation region reflects more red light than the non-oxidation region. Thus, since the oxidation region appears red (warm color), the formation of the oxidation region can be easily grasped, and the presence of a short circuit can be confirmed from the appearance.

[0028] Preferably, in one embodiment of the inductor component, the above-described oxidation film is formed on a cut surface of the above-described magnetic powder.

[0029] According to the above-described embodiment, in a case where the thickness of the green body is reduced by grinding the green body, although the magnetic powder is cut and a cut surface of the magnetic powder is exposed, since the oxidation film is formed on the cut surface of the magnetic powder, the short circuit resistance can be improved.

[0030] Preferably, in one embodiment of the inductor component, the above-described first main surface has an overlapping region overlapping the above-described inductor wiring in a position closest to the above-described first main surface, and the above-described oxidation region is located in the above-described overlapping region, as viewed in a direction orthogonal to the above-described first main surface.

[0031] According to the above-described embodiment, as viewed in a direction orthogonal to the first main surface, the oxidation region is along the inductor wiring, and thus, when a plurality of inductor wirings are provided, the insulation resistance between adjacent inductor wirings of the first main surface can be improved. Also, when a plurality of inductor components are arranged, the insulation resistance between inductor wirings of adjacent inductor components can be improved. Also, by limiting the oxidation region, the reduction in the strength of the green body due to oxidation can be suppressed.

[0032] Preferably, in one embodiment of the inductor component, the above-described first main surface has an overlapping region overlapping the above-described inductor wiring in a position closest to the above-described first main surface, and the above-described oxidation region is located in a non-overlapping region other than the above-described overlapping region of the above-described first main surface, as viewed in a direction orthogonal to the above-described first main surface.

[0033] According to the above-described embodiment, as viewed in a direction orthogonal to the above-described first main surface, the oxidation region is located in the non-overlapping region, and thus, the insulation resistance between adjacent turns of the same inductor wiring of the first main surface can be improved. Also, when a plurality of inductor wirings are provided, the insulation resistance between adjacent inductor wirings of the first main surface can be improved. Also, when a plurality of inductor components are arranged, the insulation resistance between inductor wirings of adjacent inductor components can be improved. Also, by limiting the oxidation region, the reduction in the strength of the green body due to oxidation can be suppressed.

[0034] Preferably, in one embodiment of the inductor component, the thickness of the above-described oxidation film is smaller than the D50 of the particle diameter of the above-described magnetic powder.

[0035] According to the above-described embodiment, if the oxidation is excessively performed, problems due to the reduction in the strength of the green body and the degranulation of the magnetic powder are caused, but since the oxidation film is thinner than one particle of the magnetic powder, the above-described problems can be avoided.

[0036] Preferably, in one embodiment of the inductor component,

[0037] The second main surface has the oxidation region,

[0038] The area of the oxidation region of the second main surface is larger than the area of the oxidation region of the first main surface.

[0039] According to the above embodiment, when there is no external terminal on the second main surface, for example, the oxidation region can be formed on the entire second main surface, and short circuit of the second main surface can be suppressed.

[0040] Preferably, in one embodiment of the inductor component,

[0041] The second main surface has the oxidation region,

[0042] The thickness of the oxidation film of the second main surface is thinner than the thickness of the oxidation film of the first main surface.

[0043] According to the above embodiment, when there is no external terminal on the second main surface, short circuit of the second main surface is less likely to occur than short circuit of the first main surface, and the thickness of the oxidation film of the second main surface can be thinned, whereby the strength of the blank can be maintained.

[0044] Preferably, in one embodiment of the inductor component, the oxidation region is provided only on the first main surface.

[0045] According to the above embodiment, the area of the oxidation region can be minimized, and thus the insulation can be improved while the strength of the blank is ensured.

[0046] Preferably, in one embodiment of the inductor component,

[0047] The blank has a plurality of side surfaces between the first main surface and the second main surface and connecting the first main surface and the second main surface,

[0048] The oxidation region is provided only on the first main surface and at least one of the side surfaces.

[0049] According to the above embodiment, the area of the oxidation region can be suppressed, and thus the insulation can be improved while the strength of the blank is ensured.

[0050] Preferably, in one embodiment of the inductor component,

[0051] The blank has a side surface between the first main surface and the second main surface and connecting the first main surface and the second main surface,

[0052] Further provided is a first lead wire connected to the first end portion of the inductor wire and exposed from the side surface,

[0053] The side surface from which the first lead wire is exposed has the oxidation region.

[0054] According to the above embodiment, by providing the first lead-out wiring, it is possible to ensure strength at the time of cutting of the green body at the time of monolithicization of the inductor component, and it is possible to improve the yield at the time of manufacturing. In addition, since the side surface where the first lead-out wiring is exposed has an oxidation region, when a plurality of inductor wirings are provided, it is possible to improve the insulation resistance between adjacent first lead-out wirings of the side surface. In addition, when a plurality of inductor components are arranged, it is possible to improve the insulation resistance between first lead-out wirings of adjacent inductor components.

[0055] Preferably, in one embodiment of the inductor component, the inductor wiring is one layer.

[0056] According to the above embodiment, it is possible to thin the inductor component. In particular, since short-circuiting is suppressed by the oxidation region, it is not necessary to provide an insulating layer on the surface of the green body, it is possible to realize a thin inductor component, and it is possible to improve the efficiency of obtaining inductance.

[0057] Preferably, in one embodiment of the inductor component,

[0058] The inductor wiring has a plurality of,

[0059] The plurality of inductor wirings are arranged in the same plane parallel to the first main surface and are electrically separated from each other.

[0060] According to the above embodiment, it is possible to configure an inductor array and increase the density of inductance.

[0061] Preferably, in one embodiment of the inductor component,

[0062] The green body has a directly above portion between the upper surface on the first main surface side of the inductor wiring and the first main surface,

[0063] The D50 of the particle size of the magnetic powder is 1 / 10 or more of the thickness of the directly above portion and is 2 times or less of the thickness of the directly above portion,

[0064] The thickness of the green body is 300 μm or less.

[0065] According to the above embodiment, since the thickness of the green body is 300 μm or less, it is possible to manufacture a thin inductor component. In addition, since the D50 of the particle size of the magnetic powder is 1 / 10 or more of the thickness of the directly above portion, it is possible to improve the magnetic permeability. Since the D50 of the particle size of the magnetic powder is 2 times or less of the thickness of the directly above portion, the magnetic powder is less likely to be degranulated from the green body.

[0066] In one embodiment of the inductor component, the D50 of the particle diameter of the magnetic powder in the overlapping region is larger than the D50 of the particle diameter of the magnetic powder in a region other than the overlapping region of the first main surface, i.e., a non-overlapping region.

[0067] According to the above embodiment, since the D50 of the particle diameter of the magnetic powder in the overlapping region is large, the magnetic powder with a large particle diameter is easily oxidized, and an oxidation region can be easily formed in the overlapping region. In addition, since the D50 of the particle diameter of the magnetic powder in the overlapping region is large, the magnetic powder with a large particle diameter can be arranged around the inductor wiring, and the inductance can be ensured.

[0068] In one embodiment of the inductor component, the amount of Fe element in the oxidation region is larger than the amount of Fe element in the non-oxidation region.

[0069] According to the above embodiment, since the amount of Fe element in the oxidation region is large, a large amount of Fe element can be arranged around the inductor wiring, and the inductance can be ensured.

[0070] In one embodiment of the inductor component,

[0071] The green compact has a plurality of magnetic layers stacked in a direction orthogonal to the first main surface,

[0072] The magnetic layer in contact with the inductor wiring is arranged along a part of the outer shape of the inductor wiring.

[0073] According to the above embodiment, the magnetic layer can be arranged around the inductor wiring, and the inductance can be ensured.

[0074] In one embodiment of the inductor component, the D50 of the particle diameter of the magnetic powder in the oxidation region is larger than the D50 of the particle diameter of the magnetic powder in the non-oxidation region.

[0075] According to the above embodiment, the magnetic powder with a large particle diameter is easily oxidized, and an oxidation region can be easily formed.

[0076] In addition, to solve the above problem, an inductor component according to another aspect of the present disclosure includes:

[0077] A green compact containing a magnetic powder has a first main surface and a second main surface;

[0078] An inductor wiring is provided in the green compact;

[0079] A first vertical wiring is provided in the green compact, connected to a first end portion of the inductor wiring and extending to the first main surface;

[0080] A second vertical wiring is provided in the green body and is connected to the second end of the inductor wiring and extends to the first main surface.

[0081] A first external terminal is connected to the first vertical wiring and is exposed on the first main surface.

[0082] A second external terminal is connected to the second vertical wiring and is exposed on the first main surface.

[0083] The magnetic powder has Fe as a main component.

[0084] The first main surface has an oxidized region in which Fe is 65 wt% or more and O is 24 wt% or more on the plurality of magnetic powders and a non-oxidized region in which the plurality of magnetic powders are exposed.

[0085] According to the above-described embodiment, with the oxidized region, short circuit between the first external terminal and the second external terminal via the magnetic powder of the first main surface can be suppressed, and with the non-oxidized region, reduction in the strength of the green body and reduction in the inductance can be suppressed.

[0086] According to the inductor component of one embodiment of the present disclosure, reduction in the strength of the green body and reduction in the inductance can be suppressed while suppressing short circuit between external terminals. BRIEF DESCRIPTION OF DRAWINGS

[0087] Figure 1 is a plan view of a first embodiment of an inductor component.

[0088] Figure 2A is an A-A cross-sectional view of Figure 1

[0089] Figure 2B is a B-B cross-sectional view of Figure 1

[0090] Figure 2C is a C-C cross-sectional view of Figure 1

[0091] Figure 3 is an enlarged view of a portion A of Figure 2A

[0092] Figure 4A is an explanatory view for explaining a method of manufacturing an inductor component.

[0093] Figure 4B is an explanatory view for explaining a method of manufacturing an inductor component.

[0094] Figure 4C is an explanatory view for explaining a method of manufacturing an inductor component.

[0095] Figure 4D ​​​​is a diagram for explaining the manufacturing method of the inductor component.

[0096] Figure 4E is a diagram for explaining the manufacturing method of the inductor component.

[0097] Figure 4F is a diagram for explaining the manufacturing method of the inductor component.

[0098] Figure 4G is a diagram for explaining the manufacturing method of the inductor component.

[0099] Figure 4H is a diagram for explaining the manufacturing method of the inductor component.

[0100] Figure 4I is a diagram for explaining the manufacturing method of the inductor component.

[0101] Figure 4J is a diagram for explaining the manufacturing method of the inductor component.

[0102] Figure 5A is a diagram showing the amount of Fe element [wt%] in each of the oxidized region and the non-oxidized region in Embodiment 1 to Embodiment 3.

[0103] Figure 5B is a diagram showing the amount of O element [wt%] in each of the oxidized region and the non-oxidized region in Embodiment 1 to Embodiment 3.

[0104] Figure 6 is a plan view of the second embodiment of the inductor component.

[0105] Figure 7 is an image diagram obtained by taking an image of the inductor component from a planar direction and adjusting brightness.

[0106] Figure 8 is an image diagram corresponding to the A-A cross section of Figure 6 .

[0107] Figure 9 is a diagram for explaining the manufacturing method of the inductor component. DETAILED DESCRIPTION

[0108] Hereinafter, the inductor component according to one embodiment of the present disclosure will be described in detail using the illustrated embodiments. Note that the drawings attached hereto include some schematic diagrams, and actual dimensions, ratios, and the like are not necessarily reflected.

[0109] <1st Embodiment>

[0110] (Configuration)

[0111] Figure 1is a plan view of the first embodiment of the inductor component. Figure 2A is Figure 1 an A-A sectional view of Figure 2B is Figure 1 a B-B sectional view of Figure 2C is Figure 1 a C-C sectional view of

[0112] The inductor component 1 is mounted on electronic equipment such as a personal computer, a DVD player, a digital camera, a TV, a mobile phone, and automotive electronic equipment, for example, as a component that is a rectangular parallelepiped as a whole. However, the shape of the inductor component 1 is not particularly limited, and can be a cylindrical shape, a polygonal columnar shape, a truncated cone shape, or a polygonal truncated cone shape.

[0113] As shown in Figure 1 , Figure 2A , Figure 2B , Figure 2C , the inductor component 1 includes a blank 10, a first inductor wiring 21 and a second inductor wiring 22 provided in the blank 10, a first columnar wiring 31, a second columnar wiring 32, and a third columnar wiring 33 provided in the blank 10 so as to protrude from a first main surface 10a of the blank 10 with an end surface, and a first external terminal 41, a second external terminal 42, and a third external terminal 43 protruding from the first main surface 10a of the blank 10. Figure 1 In the drawing, the first to third external terminals 41 to 43 are indicated by double-dot chain lines for convenience.

[0114] In the drawing, the thickness direction of the inductor component 1 is set as the Z direction, the positive Z direction is set as the upper side, and the negative Z direction is set as the lower side. In a plane orthogonal to the Z direction of the inductor component 1, the length direction of the inductor component 1 is set as the X direction, and the width direction of the inductor component 1 is set as the Y direction.

[0115] The blank 10 has a first main surface 10a and a second main surface 10b, and a first side surface 10c, a second side surface 10d, a third side surface 10e, and a fourth side surface 10f that are located between the first main surface 10a and the second main surface 10b and connect the first main surface 10a and the second main surface 10b.

[0116] The first main surface 10a and the second main surface 10b are disposed on opposite sides in the Z direction, the first main surface 10a is disposed on the positive Z direction, and the second main surface 10b is disposed on the negative Z direction. The first side surface 10c and the second side surface 10d are disposed on opposite sides in the X direction, the first side surface 10c is disposed on the negative X direction, and the second side surface 10d is disposed on the positive X direction. The third side surface 10e and the fourth side surface 10f are disposed on opposite sides in the Y direction, the third side surface 10e is disposed on the negative Y direction, and the fourth side surface 10f is disposed on the positive Y direction.

[0117] The green sheet 10 has a first magnetic layer 11 and a second magnetic layer 12 stacked in order along the positive Z direction. The first magnetic layer 11 and the second magnetic layer 12 each contain a magnetic powder and a resin containing the magnetic powder. The resin is, for example, an organic insulating material composed of an epoxy-based, phenol-based, liquid crystal polymer-based, polyimide-based, acrylic-based, or a mixture containing the same. The magnetic powder is, for example, an FeSi-based alloy such as FeSiCr, an FeCo-based alloy, an Fe-based alloy such as NiFe, or an amorphous alloy thereof. Thus, compared to a magnetic layer composed of ferrite, the direct current superimposition characteristics can be improved by using the magnetic powder, and the magnetic powders are insulated from each other by the resin, so the loss (iron loss) at high frequencies can be reduced.

[0118] The first inductor wiring 21 and the second inductor wiring 22 are disposed on a plane orthogonal to the Z direction between the first magnetic layer 11 and the second magnetic layer 12. Specifically, the first magnetic layer 11 is present in the negative Z direction of the first inductor wiring 21 and the second inductor wiring 22, and the second magnetic layer 12 is present in the positive Z direction and a direction orthogonal to the positive Z direction of the first inductor wiring 21 and the second inductor wiring 22.

[0119] The first inductor wiring 21 extends linearly along the X direction when viewed in the Z direction. A portion of the second inductor wiring 22 extends linearly along the X direction when viewed in the Z direction, and the other portion extends linearly along the Y direction, in other words, extends in an L shape.

[0120] The thickness of the first and second inductor wirings 21, 22 is preferably, for example, 40 μm to 120 μm. As an example of the first and second inductor wirings 21, 22, the thickness is 35 μm, the wiring width is 50 μm, and the maximum space between the wirings is 200 μm.

[0121] The first inductor wiring 21 and the second inductor wiring 22 are composed of an electrically conductive material, for example, a low-resistance metal material such as Cu, Ag, Au, Al, or the like. In the present embodiment, the inductor component 1 has only one layer of the first and second inductor wirings 21, 22, and the height of the inductor component 1 can be reduced. Note that the inductor wiring can be composed of two layers of a seed layer and a plated layer, and the seed layer can contain Ti, Ni.

[0122] The first end portion 21a of the first inductor wiring 21 is electrically connected to the first columnar wiring 31, and the second end portion 21b of the first inductor wiring 21 is electrically connected to the second columnar wiring 32.

[0123] In other words, the first inductor wiring 21 has a pad portion with a wide line width at the first and second end portions 21a, 21b, and is directly connected to the first and second columnar wirings 31, 32 at the pad portion.

[0124] The first end portion 22a of the second inductor wiring 22 is electrically connected to the third columnar wiring 33, and the second end portion 22b of the second inductor wiring 22 is electrically connected to the second columnar wiring 32. In short, the second inductor wiring 22 has a pad portion at the first end portion 22a, and is directly connected to the third columnar wiring 33 at the pad portion. The second end portion 22b of the second inductor wiring 22 is shared with the second end portion 21b of the first inductor wiring 21.

[0125] The first end portion 21a of the first inductor wiring 21 and the first end portion 22a of the second inductor wiring 22 are located on the first side surface 10c side of the green sheet 10 when viewed in the Z direction. The second end portion 21b of the first inductor wiring 21 and the second end portion 22b of the second inductor wiring 22 are located on the second side surface 10d side of the green sheet 10 when viewed in the Z direction.

[0126] The first lead-out wiring 201 is connected to the first end portion 21a of the first inductor wiring 21 and the first end portion 22a of the second inductor wiring 22, respectively, and the first lead-out wiring 201 is exposed from the first side surface 10c. The second lead-out wiring 202 is connected to the second end portion 21b of the first inductor wiring 21 and the second end portion 22b of the second inductor wiring 22, and the second lead-out wiring 202 is exposed from the second side surface 10d.

[0127] The first lead-out wiring 201 and the second lead-out wiring 202 are wirings connected to a power supply wiring when plating is additionally performed after the shapes of the first and second inductor wirings 21, 22 are formed in the manufacturing process of the inductor component 1. The additional plating can be easily performed in the inductor substrate state before the inductor component 1 is singulated by the power supply wiring, and the distance between the wirings can be narrowed. In addition, the distance between the wirings of the first and second inductor wirings 21, 22 is narrowed by the additional plating, and thus the magnetic coupling of the first and second inductor wirings 21, 22 can be improved. In addition, by providing the first lead-out wiring 201 and the second lead-out wiring 202, the strength can be ensured at the time of cutting of the green sheet 10 at the time of singulation of the inductor component 1, and the yield at the time of manufacturing can be improved.

[0128] The first to third columnar wirings 31 to 33 extend in the Z direction from the respective inductor wirings 21, 22 and pass through the inside of the second magnetic layer 12. The "vertical wiring" described in the scope of the columnar wiring patent claim corresponds.

[0129] The first columnar wiring 31 extends from the upper surface of the first end portion 21a of the first inductor wiring 21 to the first main surface 10a of the green sheet 10, and the end surface of the first columnar wiring 31 is exposed from the first main surface 10a of the green sheet 10. The second columnar wiring 32 extends from the upper surface of the second end portion 21b of the first inductor wiring 21 to the first main surface 10a of the green sheet 10, and the end surface of the second columnar wiring 32 is exposed from the first main surface 10a of the green sheet 10. The third columnar wiring 33 extends from the upper surface of the first end portion 22a of the second inductor wiring 22 to the first main surface 10a of the green sheet 10, and the end surface of the third columnar wiring 33 is exposed from the first main surface 10a of the green sheet 10.

[0130] Therefore, the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 extend linearly from the first inductor wiring 21 and the second inductor wiring 22 in a direction orthogonal to the first main surface 10a to the end surfaces exposed from the first main surface 10a. Thus, the first external terminal 41, the second external terminal 42, and the third external terminal 43 can be connected to the first inductor wiring 21 and the second inductor wiring 22 at a shorter distance, and the inductor component 1 can be made low in resistance and high in inductance. The first to third columnar wirings 31 to 33 are composed of an electrically conductive material, for example, the same material as that of the inductor wirings 21 and 22.

[0131] Note that when the first and second inductor wirings 21 and 22 are covered with an insulating layer composed of a non-magnetic material, the first to third columnar wirings 31 to 33 can be electrically connected to the first and second inductor wirings 21 and 22 via via-hole wirings that penetrate the insulating layer. The via-hole wirings are conductors having a smaller line width (diameter, cross-sectional area) than the columnar wirings. In this case, the "vertical wirings" described in the scope of the patent claim are composed of the via-hole wirings and the columnar wirings.

[0132] The first to third external terminals 41 to 43 are provided on the first main surface 10a of the green sheet 10. The first to third external terminals 41 to 43 are composed of an electrically conductive material, for example, three layers of Cu, Ni, and Au arranged from the inside to the outside in this order, Cu being excellent in stress resistance and low in resistance, Ni being excellent in corrosion resistance, and Au being excellent in solder wettability and reliability.

[0133] The first external terminal 41 contacts the end face exposed from the first main surface 10a of the blank 10 of the first columnar wiring 31 and is electrically connected to the first columnar wiring 31. Thus, the first external terminal 41 is electrically connected to the first end 21a of the first inductor wiring 21. The second external terminal 42 contacts the end face exposed from the first main surface 10a of the blank 10 of the second columnar wiring 32 and is electrically connected to the second columnar wiring 32. Thus, the second external terminal 42 is electrically connected to the second end 21b of the first inductor wiring 21 and the second end 22b of the second inductor wiring 22. The third external terminal 43 contacts the end face of the third columnar wiring 33 and is electrically connected to the third columnar wiring 33, and is electrically connected to the first end 22a of the second inductor wiring 22.

[0134] The lower surfaces of the first inductor wiring 21 and the second inductor wiring 22 are each covered by a gold insulating layer 61. The insulating layer 61 is made of a non-magnetic insulating material, such as epoxy resin, phenolic resin, or polyimide resin. It should be noted that the insulating layer 61 may contain fillers such as silicon dioxide, which can improve the strength, processability, and electrical properties of the insulating layer 61.

[0135] Figure 3 yes Figure 2A An enlarged view of part A. (See image below.) Figure 3 As shown, the first magnetic layer 11 and the second magnetic layer 12 contain magnetic powder 100 and resin 101 containing magnetic powder 100. Magnetic powder 100 is primarily composed of Fe. "Fe is primarily composed of Fe" means that magnetic powder 100 is composed of elemental Fe or Fe-based alloys in which Fe is the most abundant element, such as FeSi, FeSiCr, FeSiAl, FeNi, etc. It should be noted that magnetic powder 100 can have an amorphous structure or a crystalline structure.

[0136] The first main surface 10a of the blank 10 has an oxidized region R1 where an oxide film 102 formed by the oxidation of multiple magnetic powders 100 is exposed, and a non-oxidized region R2 where multiple magnetic powders 100 are exposed. The oxidized region R1 refers to a region where Fe content is 65 wt% or more and O content is 24 wt% or more. The non-oxidized region R2 refers to a region where Fe content is 65 wt% or more and O content is less than 24 wt%. In other words, the first main surface 10a of the blank 10 has an oxidized region R1 where Fe content is 65 wt% or more and O content is 24 wt% or more on multiple magnetic powders 100, and a non-oxidized region R2 where multiple magnetic powders 100 are exposed.

[0137] For the composition analysis of the oxidized region Rl and the non-oxidized region R2, analysis is performed by EDX (Energy Dispersive X-ray Analysis) from the SEM (Scanning Electron Microscope) image of the first main surface 10a. Specifically, the SEM image is captured at a magnification of, for example, 300 times at which the plurality of magnetic powders 100 enter, and the oxidized region Rl and the non-oxidized region R2 are subjected to point analysis or composition analysis is performed only on the regions selected by EDX. Here, as noise, C as a resin component of the magnetic layer, components from the insulating filler, metal components used in vapor deposition and the like are sometimes detected, and the proportion of the corresponding composition (Fe element, O element) is calculated as a denominator excluding these components. For the separation of the elements included in the composition of the magnetic powder from the noise included in the denominator, the central portion of the compact is exposed by cross-section polishing in advance, and the composition detected at the cut surface of the magnetic powder exposed at the cross-section is taken as a reference, and the composition not detected here is taken as noise.

[0138] According to the above-described configuration, with the oxidized region Rl, short circuiting via the magnetic powder 100 of the first main surface 10a between the first external terminal 41 and the second external terminal 42 and between the third external terminal 43 and the second external terminal 42 can be suppressed, and with the non-oxidized region R2, reduction in the strength of the compact 10 and reduction in the inductance can be suppressed.

[0139] Specifically, since the oxidized region Rl is provided, even if the filling rate of the magnetic powder 100 is increased in order to increase the inductance, short circuiting of the first external terminal 41 and the second external terminal 42 via the magnetic powder 100 of the first main surface 10a can be suppressed. Since the oxidized region Rl is provided, the thickness of the inductor component 1 can be reduced compared to the case where a resin film having insulation is provided at the first main surface 10a. The oxidized region Rl is formed discontinuously, specifically, the oxidized region Rl is formed in spots. On the other hand, since the non-oxidized region R2 is provided, reduction in the strength of the compact 10 and deterioration in the magnetic characteristics due to the oxidized film can be suppressed.

[0140] In addition, since the first inductor wiring 21 and the second inductor wiring 22 are one layer, the inductor component 1 can be reduced in thickness. In particular, since short circuiting is suppressed by the oxidized region Rl, it is not necessary to provide an insulating layer on the surface of the compact 10, a thin inductor component 1 can be realized, and the efficiency of obtaining the inductance can be improved.

[0141] As Figure 3As shown, the magnetic powder 100 of the oxidized region Rl includes a thermomagnetic powder in direct contact with the resin 101. Specifically, the magnetic powder 100 includes a magnetic powder not coated with an oxidized film in advance. According to the above-described configuration, since the magnetic powder 100 of the oxidized region Rl is in direct contact with the resin 101, the adhesion of the magnetic powder 100 to the resin 101 is improved, and reduction in the green strength and reduction in the inductance can be more effectively suppressed.

[0142] Alternatively, although not shown, the magnetic powder 100 of the oxidized region Rl includes a magnetic powder in contact with the resin 101 via an oxidized film. Specifically, the magnetic powder 100 includes a magnetic powder coated with an oxidized film in advance. According to the above-described configuration, since the magnetic powder 100 of the oxidized region Rl is in contact with the resin 101 via an oxidized film, short circuit can be more effectively suppressed. In addition, the magnetic powder 100 of the oxidized region Rl can include a magnetic powder coated with an oxidized film on a part of the surface thereof and not coated with an oxidized film on the remaining part. That is, the magnetic powder 100 of the oxidized region Rl can include a magnetic powder in direct contact with the resin 101 on a part thereof and in contact with the resin 101 via an oxidized film on the remaining part.

[0143] It is preferable that the oxidized region Rl have a larger proportion of the reflectance of a wavelength of 600 nm or less to the reflectance of a wavelength of less than 600 nm than the non-oxidized region R2. According to the above-described configuration, the oxidized region Rl has a larger reflectance of red than the non-oxidized region R2. Therefore, since the oxidized region Rl appears red (warm color), the formation of the oxidized region Rl can be easily grasped by visual observation or an appearance inspection device or the like, and the short circuit resistance can be confirmed from the appearance.

[0144] It is preferable that the oxidized film 102 be formed on the cut surface of the magnetic powder 100. According to the above-described configuration, in a case where the green body 10 is ground to reduce the thickness of the green body, although the magnetic powder 100 is cut and the cut surface of the magnetic powder 100 is exposed, the oxidized film 102 is formed on the cut surface of the magnetic powder 100, and thus the short circuit resistance can be improved.

[0145] On the other hand, in the known magnetic powder, the surface is coated with organic or inorganic substances such as phosphoric acid and SiO2 to improve the insulation. By arranging such a magnetic powder on the surface of the core, the insulation of the surface of the core can be improved. However, if a thin inductor component is to be manufactured, the thickness of the blank (magnetic layer) needs to be adjusted by grinding. At this time, the surface protective film of the magnetic powder is peeled off, and the inside of the magnetic powder is exposed, so the short circuit resistance is reduced. Therefore, in the present embodiment, by forming the oxide film 102 on the inside of the exposed magnetic powder 100 whose insulation resistance is reduced, the short circuit resistance is improved, and the thickness is not unnecessarily increased. However, the oxide film 102 can also be formed on the surface of the non-cut surface of the non-magnetic powder 100. In addition, as shown in the above assumption, in the oxidation region R1, the portion where the magnetic powder 100 is buried in the resin 101 is not limited to the case where the oxide film 102 formed by oxidation of the magnetic powder 100 is covered, but can also be covered with organic or inorganic substances such as phosphoric acid and SiO2.

[0146] The thickness of the oxide film 102 is preferably less than the D50 of the particle diameter of the magnetic powder 100. According to the above configuration, if the oxidation is excessively performed, problems due to the reduction in the strength of the blank 10 and the degranulation of the magnetic powder 100 can occur, but since the oxide film 102 is thinner than one particle of the magnetic powder 100, the problems can be avoided.

[0147] Here, the D50 of the particle diameter of the magnetic powder 100 is determined from the SEM image of the cross section of the central portion in the long direction of the blank 10 of the inductor component, unless otherwise specified. At this time, the SEM image preferably contains 10 or more magnetic powders 100, and is taken at a magnification of 2000 times, for example. Three or more SEM images as described above are taken from the above cross section, the magnetic powders 100 and the others are classified by binarization or the like, the equivalent circle diameters of the respective magnetic powders 100 within the SEM images are calculated, and the median value (median particle diameter) when the equivalent circle diameters are arranged in order of size is taken as the D50 of the particle diameter of the magnetic powder 100. In addition, the cumulative number is started from the magnetic powders with small equivalent circle diameters, and the equivalent circle diameter when the number first exceeds 90% of the total is taken as the D90 of the particle diameter of the magnetic powder 100.

[0148] As Figure 2CAs shown, the green sheet 10 has a first directly above portion 215 between the upper surface 212 on the side of the first main surface 10a of the first inductor wiring 21 and the first main surface 10a and a second directly above portion 225 between the upper surface 222 on the side of the first main surface 10a of the second inductor wiring 22 and the first main surface 10a. The D50 of the particle diameter of the magnetic powder 100 is preferably 1 / 10 or more of the thickness of the first and second directly above portions 215, 225 and 2 times or less of the thickness of the first and second directly above portions 215, 225, and the thickness of the green sheet 10 is 300 μm or less.

[0149] According to the above-described configuration, since the thickness of the green sheet 10 is 300 μm or less, a thin inductor component 1 can be obtained. Further, since the D50 of the particle diameter of the magnetic powder 100 is 1 / 10 or more of the thickness of the first and second directly above portions 215, 225, the magnetic permeability can be improved. Since the D50 of the particle diameter of the magnetic powder 100 is 2 times or less of the thickness of the first and second directly above portions 215, 225, the magnetic powder 100 is less likely to be degranulated from the green sheet 10.

[0150] On the contrary, if the D50 of the particle diameter of the magnetic powder 100 is smaller than 1 / 10 of the thickness of the first and second directly above portions 215, 225, the magnetic permeability cannot be improved. If the D50 of the particle diameter of the magnetic powder 100 is larger than 2 times of the thickness of the first and second directly above portions 215, 225, the holding force of the resin 101 around the magnetic powder 100 becomes small, and the magnetic powder 100 is easily degranulated, as a result, when the magnetic powder 100 is degranulated, the first and second inductor wirings 21, 22 are exposed, and the strength of the green sheet 10 is reduced.

[0151] It is preferable that the D50 of the particle diameter of the magnetic powder 100 in the oxidized region be larger than the D50 of the particle diameter of the magnetic powder 100 in the non-oxidized region. According to the above-described configuration, the magnetic powder 100 with a large particle diameter is easily oxidized, and the oxidized region can be easily formed.

[0152] It is preferable that the second main surface 10b have an oxidized region Rl, and the area of the oxidized region Rl of the second main surface 10b be larger than the area of the oxidized region Rl of the first main surface 10a. According to the above-described configuration, when the external terminal is not present in the second main surface 10b, for example, the oxidized region Rl can be formed on the entire surface of the second main surface 10b, and the short circuit of the second main surface 10b can be suppressed.

[0153] Preferably, the second main surface 10b has an oxide region R1, and the thickness of the oxide film 102 on the second main surface 10b is thinner than the thickness of the oxide film 102 on the first main surface 10a. According to the above configuration, when there are no external terminals on the second main surface 10b, since short circuits on the second main surface 10b are less likely to occur than short circuits on the first main surface 10a, the thickness of the oxide film 102 on the second main surface 10b can be reduced, thereby maintaining the strength of the blank 10.

[0154] Preferably, the oxide region R1 is only provided on the first main surface 10a. With this configuration, the area of ​​the oxide region R1 can be minimized, thus improving insulation while ensuring the strength of the blank 10. For example, this structure can be achieved by attaching a protective film (tape) to the second main surface 10b during the manufacturing process.

[0155] Preferably, the oxide region R1 is only provided on the first main surface 10a and at least one side surface 10c to 10f. According to the above configuration, the area of ​​the oxide region R1 can be suppressed, thus improving the insulation while ensuring the strength of the blank 10.

[0156] Preferably, the first side 10c exposed by the first lead wire 201 has an oxide region R1. According to the above configuration, when multiple inductor wires 21 and 22 are provided, the insulation resistance between adjacent first lead wires 201 and 201 on the first side 10c can be increased. Furthermore, when multiple inductor components 1 are arranged, the insulation resistance between adjacent first lead wires 201 and 201 of the inductor components 1 can be increased. Similarly, the second side 10d exposed by the second lead wire 202 may have an oxide region R1.

[0157] Preferably, there are multiple inductor wirings, which are arranged on the same plane parallel to the first main surface 10a and electrically separated from each other. Based on this configuration, an inductor array is formed, which increases the inductance density.

[0158] Preferably, there are multiple inductor wirings arranged in a direction orthogonal to the first main surface 10a and electrically connected to each other. According to the above configuration, the inductance can be improved by stacking multiple inductor wirings.

[0159] (Manufacturing method)

[0160] Next, the manufacturing method of inductor component 1 will be described. Figures 4A-4J and Figure 1 B-B section ( Figure 2B )correspond.

[0161] like Figure 4AAs shown in FIG. 1, a base substrate 70 is prepared. The base substrate 70 is composed of, for example, an inorganic material such as ceramic, glass, silicon, or the like. A first insulating layer 71 is applied to a main surface of the base substrate 70, and the first insulating layer 71 is cured.

[0162] As shown in FIG. 2, a second insulating layer 61 is applied to the first insulating layer 71, and a prescribed pattern is formed using a photolithography method, and the second insulating layer 61 is cured. Figure 4B As shown in FIG. 3, a seed layer (not shown) is formed on the first insulating layer 71 and the second insulating layer 61 by a publicly known method such as a sputtering method or an evaporation method. Thereafter, a DFR (dry film resist) 75 is attached, and a prescribed pattern is formed in the DFR 75 using a photolithography method. The prescribed pattern is a through hole corresponding to a position at which the first inductor wiring 21 and the second inductor wiring 22 are to be provided on the second insulating layer 61.

[0163] As shown in FIG. 4, power is supplied to the seed layer, and the first inductor wiring 21 and the second inductor wiring 22 are formed on the second insulating layer 61 using an electroplating method. Thereafter, the DFR 75 is peeled off, and the seed layer is etched. In this manner, the first inductor wiring 21 and the second inductor wiring 22 are formed on the main surface of the base substrate 70. Figure 4C As shown in FIG. 5, the DFR 75 is attached again, and a prescribed pattern is formed in the DFR 75 using a photolithography method. The prescribed pattern is a through hole corresponding to a position at which the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 are to be provided on the first inductor wiring 21 and the second inductor wiring 22.

[0164] As shown in FIG. 6, the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 are formed on the first inductor wiring 21 and the second inductor wiring 22 using electroplating. Thereafter, the DFR 75 is peeled off. Note that the seed layer can be used for electroplating, in which case the seed layer needs to be etched. Alternatively, the seed layer formed when the first inductor wiring 21 and the second inductor wiring 22 are formed is not etched and remains, and the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 can be formed by supplying power via the seed layer, in which case the seed layer also needs to be etched. Figure 4D As shown in FIG. 7, the DFR 75 is attached again, and a prescribed pattern is formed in the DFR 75 using a photolithography method. The prescribed pattern is a through hole corresponding to a position at which the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 are to be provided on the first inductor wiring 21 and the second inductor wiring 22.

[0165] Figure 4E As shown in FIG. 8, the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 are formed on the first inductor wiring 21 and the second inductor wiring 22 using electroplating. Thereafter, the DFR 75 is peeled off. Note that the seed layer can be used for electroplating, in which case the seed layer needs to be etched. Alternatively, the seed layer formed when the first inductor wiring 21 and the second inductor wiring 22 are formed is not etched and remains, and the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 can be formed by supplying power via the seed layer, in which case the seed layer also needs to be etched.

[0166] As shown in FIG. 9, the DFR 75 is attached again, and a prescribed pattern is formed in the DFR 75 using a photolithography method. The prescribed pattern is a through hole corresponding to a position at which the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 are to be provided on the first inductor wiring 21 and the second inductor wiring 22. Figure 4F As shown in FIG. 10, the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 are formed on the first inductor wiring 21 and the second inductor wiring 22 using electroplating. Thereafter, the DFR 75 is peeled off. Note that the seed layer can be used for electroplating, in which case the seed layer needs to be etched. Alternatively, the seed layer formed when the first inductor wiring 21 and the second inductor wiring 22 are formed is not etched and remains, and the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 can be formed by supplying power via the seed layer, in which case the seed layer also needs to be etched.

[0167] Figure 4G ​​As shown, a magnetic sheet is formed by pressing the first inductor wiring 21 and the second inductor wiring 22 together from the top of the main surface of the substrate 70 to form the second magnetic layer 12. The second magnetic layer 12 covers the first inductor wiring 21 and the second inductor wiring 22, as well as the first pillar wiring 31, the second pillar wiring 32, and the third pillar wiring 33. Subsequently, the upper surface of the second magnetic layer 12 is ground, exposing the end faces of the first pillar wiring 31, the second pillar wiring 32, and the third pillar wiring 33. It should be noted that, in order to reduce the degradation of the magnetic powder due to environmental stress, a surface protective film formed from inorganic materials such as glass and silicon, or resin, is sometimes used. Thus, when the magnetic powder is covered by the surface protective film, the surface protective film can be peeled off by grinding, thereby oxidizing the surface of the magnetic powder.

[0168] like Figure 4H As shown, the substrate 70 and the first insulating layer 71 are removed by grinding. At this time, the first insulating layer 71 can be used as a release layer, and the substrate 70 and the first insulating layer 71 are removed by peeling. Subsequently, other magnetic sheets are pressed from below the first inductor wiring 21 and the second inductor wiring 22 to form the first magnetic layer 11, thus covering the first inductor wiring 21 and the second inductor wiring 22 with the first magnetic layer 11. Then, the first magnetic layer 11 is ground to a predetermined thickness.

[0169] like Figure 4I As shown, a protective film 75, such as adhesive tape, is attached to the lower surface of the first magnetic layer 11, and the second magnetic layer 12 is oxidized. Specifically, a baking process is performed by humidification. At this time, the baking process is carried out at a temperature and humidity that allows large-particle-size magnetic powder to oxidize easily while small-particle-size magnetic powder is not easily oxidized. This allows an oxide film to be formed on the large-particle-size magnetic powder, easily forming oxidized and non-oxidized regions. Alternatively, the surface of the second magnetic layer 12 can be washed with water and dried instead of baking. In this case, by adjusting the washing or drying time, an oxide film can be formed on the large-particle-size magnetic powder, easily forming both oxidized and non-oxidized regions.

[0170] like Figure 4J As shown, after removing the protective film 75, the inductor component 1 is monolithically assembled using the cutting line D. Subsequently, a metal film is formed on the columnar wirings 31-33 by electroless electroplating, forming the first external terminal 41, the second external terminal 42, and the third external terminal 43. Thus, as... Figure 2B Manufacturing inductor component 1.

[0171] (Example)

[0172] Next, in Example 1, Example 2, and Example 3, the amounts of Fe element and O element in the oxidized region and the non-oxidized region were found. Figure 5A is a graph showing the amounts of Fe element [wt%] in the oxidized region and the non-oxidized region in Example 1 to Example 3. Figure 5B is a graph showing the amounts of O element [wt%] in the oxidized region and the non-oxidized region in Example 1 to Example 3.

[0173] In Example 1, the magnetic powder had a composition of FeSi, and the D50 of the particle diameter of the magnetic powder was 15 μm. In Example 2, the magnetic powder had a composition of FeSi, the amount of Fe in Example 2 was 1.2 when the amount of Fe in Example 1 was set to 1, and the D50 of the particle diameter of the magnetic powder was 16 μm. In Example 3, the magnetic powder had a composition of FeSiCr, the amount of Fe in Example 3 was 0.9 when the amount of Fe in Example 1 was set to 1, and the D50 of the particle diameter of the magnetic powder was 3 μm.

[0174] As shown in Figure 5A , in Example 1, the Fe element in the oxidized region was 72 wt%, and the Fe element in the non-oxidized region was 75 wt%. In Example 2, the Fe element in the oxidized region was 71 wt%, and the Fe element in the non-oxidized region was 90 wt%. In Example 3, the Fe element in the oxidized region was 73 wt%, and the Fe element in the non-oxidized region was 70 wt%.

[0175] As shown in Figure 5B , in Example 1, the O element in the oxidized region was 24 wt%, and the O element in the non-oxidized region was 18 wt%. In Example 2, the O element in the oxidized region was 26 wt%, and the O element in the non-oxidized region was 8 wt%. In Example 3, the O element in the oxidized region was 27 wt%, and the O element in the non-oxidized region was 23 wt%. Figure 5B In Example 2, the position of 24 wt% is indicated by a dotted line.

[0176] Therefore, in the oxidized region, the Fe element was 65 wt% or more and the O element was 24 wt% or more. In the non-oxidized region, the Fe element was 65 wt% or more and the O element was less than 24 wt%.

[0177] <2nd Embodiment>

[0178] Figure 6 is a plan view showing the 2nd embodiment of the inductor component. The 2nd embodiment differs from the configuration of the green body of the 1st embodiment. The different configuration will be described below. Note that the other structures are the same as those of the 1st embodiment, and therefore the same symbols are marked, and the description thereof is omitted.

[0179] As shown in Figure 6As shown, in the inductor component 1A of the second embodiment, the first main surface 10a of the blank 10A has an overlapping region Zl in which the first and second inductor wirings 21, 22 in the position closest to the first main surface 10a overlap, and a region other than the overlapping region Zl, i.e., a non-overlapping region Z2, when viewed from a direction orthogonal to the first main surface 10a. The oxidized region Rl is located in the overlapping region Zl. The overlapping region Zl can partially include the non-oxidized region R2.

[0180] According to the above-described configuration, the oxidized region Rl is along the first and second inductor wirings 21, 22 when viewed from a direction orthogonal to the first main surface 10a, and thus the insulation resistance between the adjacent inductor wirings 21, 22 of the first main surface 10a can be improved. In addition, when a plurality of inductor components 1A are arranged, the insulation resistance between the inductor wirings of the adjacent inductor components 1A can be improved. Further, by limiting the oxidized region, the reduction in the strength of the blank due to oxidation can be suppressed.

[0181] Figure 7 is an image image of the inductor component 1A taken from the planar direction and adjusted in brightness. As shown in Figure 7 Due to the presence of the oxidized region Rl, the overlapping region Zl appears brighter than the non-overlapping region Z2. In fact, the overlapping region Zl appears red.

[0182] Figure 8 is an image image corresponding to the A-A cross section of Figure 6 As shown in Figure 8 The D50 of the particle diameter of the magnetic powder 100 in the overlapping region Zl is larger than the D50 of the particle diameter of the magnetic powder 100 in the non-overlapping region Z2. Here, the particle diameter of the magnetic powder 100 is measured from the SEM image on the first main surface 10a, not from the cross section on an arbitrary face of the inductor component. The specific method of calculating the particle diameter from the SEM image is the same as the method of calculating the particle diameter of the magnetic powder 100 described in the first embodiment.

[0183] According to the above-described configuration, since the D50 of the particle diameter of the magnetic powder 100 in the overlapping region Zl is large, the magnetic powder 100 with a large particle diameter is easily oxidized, and the oxidized region Rl can be easily formed in the overlapping region Zl. In addition, since the D50 of the particle diameter of the magnetic powder 100 in the overlapping region Zl is large, the magnetic powder 100 with a large particle diameter can be arranged around the inductor wiring, and the inductance can be ensured.

[0184] For example, as the magnetic powder used in the non-oxidized region R2, a magnetic powder having a D50 of the particle diameter of 2 μm or less, composed of FeSiCr alloy or the like, and in which a passivation film other than Fe-based is easily formed on the surface of the magnetic powder can be given. Figure 8In the image, magnetic powder with a particle size D50 of 1.4 μm and a particle size D90 of 3.1 μm was used. On the other hand, magnetic powders used in the oxide region R1 can be exemplified by having a particle size D50 of 5 μm or more and a high Fe composition ratio, such as FeSi alloys. Figure 8 The image shows magnetic powder with a particle size of D50 of 6.8 μm and a particle size of D90 of 14.0 μm.

[0185] Preferably, the amount of Fe in the oxidized region R1 is greater than the amount of Fe in the non-oxidized region R1. Specifically, the oxide film in the oxidized region R1 is iron oxide. Based on the above configuration, since the amount of Fe in the oxidized region R1 is greater, a large amount of Fe can be arranged around the first and second inductor wirings 21 and 22, thus ensuring inductance.

[0186] The preferred blank 10A has a first magnetic layer 11, a second magnetic layer 12 and a third magnetic layer 13 stacked in a direction orthogonal to the first main surface 10a. Figure 8 For convenience, the boundaries of the first magnetic layer 11, the second magnetic layer 12, and the third magnetic layer 13 are depicted with dashed lines. The second magnetic layer 12 mainly comprises large-particle magnetic powder 100, and the third magnetic layer 13 mainly comprises small-particle magnetic powder 100. The second magnetic layer 12, which is in contact with the first and second inductor wirings 21 and 22, is arranged along a portion of the outline of the first and second inductor wirings 21 and 22. According to the above configuration, the second magnetic layer 12 can be arranged around the first and second inductor wirings 21 and 22, which ensures inductance.

[0187] The manufacturing method of the inductor component 1A at this time will be described. (Compared to the first embodiment) Figures 4A-4F Similarly. Afterwards, as... Figure 9 As shown, a magnetic sheet, mainly containing large-particle-size magnetic powder 100, is pressed onto the top of the first inductor wiring 21 and the second inductor wiring 22, serving as the second magnetic layer 12, thus covering the first inductor wiring 21 and the second inductor wiring 22. Furthermore, a magnetic sheet, mainly containing small-particle-size magnetic powder 100, is pressed onto the top of the magnetic sheet of the second magnetic layer 12, serving as the third magnetic layer 13, thus covering the second magnetic layer 12. At this time, in the portions where the first inductor wiring 21 and the second inductor wiring 22 are present, the second magnetic layer 12 and the third magnetic layer 13 protrude upwards. That is, the main surfaces of the second magnetic layer 12 and the third magnetic layer 13 have an uneven shape, protruding in the overlapping region Z1 and recessed in the non-overlapping region Z2.

[0188] Subsequently, a portion of the second magnetic layer 12 and the third magnetic layer 13 is ground. At this time, as... Figure 8As shown, the grinding is performed so that the 2nd magnetic layer 12 constitutes the 1st main surface 10a in the overlapping region Zl, and the 3rd magnetic layer 13 constitutes the 1st main surface 10a in the non-overlapping region Z2. Thus, the main surface of the 2nd magnetic layer 12 is flat in the overlapping region Zl and is concave in the non-overlapping region Z2, and the 3rd magnetic layer 13 becomes a shape that fills in the concave of the main surface of the 2nd magnetic layer 12 in the non-overlapping region Z2. Thereafter, the same as the 1st embodiment. Figures 4H-4J

[0189] Note that, as viewed from the direction orthogonal to the 1st main surface 10a, the oxidized region Rl is located in the non-overlapping region Z2 and not in the non-overlapping region Zl. At this time, the non-overlapping region Z2 can partially contain the non-oxidized region R2. According to the above-described configuration, since the oxidized region Rl is in the non-overlapping region Z2, the inter-wiring insulation resistance between adjacent turns of the same inductor wiring of the 1st main surface 10a can be improved. In addition, when a plurality of inductor wirings are provided, the inter-wiring insulation resistance between adjacent inductor wirings of the 1st main surface 10a can be improved. In addition, when a plurality of inductor components are arranged, the inter-wiring insulation resistance between inductor wirings of adjacent inductor components can be improved. In addition, by limiting the oxidized region Rl, the reduction in the strength of the green body due to oxidation can be suppressed. Note that, in order to form the above-described configuration, it is sufficient to reverse the magnetic sheet of the 2nd magnetic layer 12 and the magnetic sheet of the 3rd magnetic layer 13.

[0190] In addition, as the 2nd magnetic layer 12, a magnetic sheet mainly containing a magnetic powder of a large particle size is used, and as the 3rd magnetic layer 13, a magnetic sheet mainly containing a magnetic powder of a small particle size is used, and as the 2nd magnetic layer 12, it is sufficient to use a magnetic sheet that is more easily oxidized than the magnetic sheet of the 3rd magnetic layer 13.

[0191] Note that the present disclosure is not limited to the above-described embodiments, and design changes can be made within the scope of the gist of the present disclosure. For example, the characteristic points of each of the 1st and 2nd embodiments can be variously combined.

[0192] In the above-described embodiments, two of the 1st inductor wiring and the 2nd inductor wiring are arranged in the green body, but one or three or more inductor wirings can also be arranged, in which case the external terminals and the columnar wirings are also four or more, respectively.

[0193] ​In the above embodiment, the "inductor wiring" refers to a structure, shape, material, etc. that generates magnetic flux in the magnetic layer when current flows therethrough, thereby imparting inductance to the inductor component. In particular, it is not limited to a straight line or a curve (spiral = two-dimensional curve) extending in a plane as in the embodiment, and various known wiring shapes such as meander wiring can be used. In addition, the total number of inductor wirings is not limited to one layer, and can be two or more layers. In addition, the shape of the columnar wiring is rectangular when viewed in the Z direction, but can be circular, elliptical, or oblong.

[0194] In the above embodiment, the first main surface of the blank is exposed in a portion excluding the external terminals, but can be covered with an insulating film. At this time, the insulating film is provided to the portion of the first main surface of the blank where the first to third external terminals are not provided. Thereby, the insulativity between the first to third external terminals can be improved.

[0195] In addition, the control of the oxidized region and the non-oxidized region is not limited to the method described in the above embodiment, and other formation methods can be used. For example, the fluidity of the resin of the magnetic layer can be improved. Thereby, the density of the magnetic powder in the upper portion of the inductor wiring can be improved, and the oxidized region can be formed in the upper portion of the inductor wiring.

[0196] In addition, the fluidity of the resin of the magnetic layer can be reduced. Thereby, the magnetic powder flows at the same time as the resin, and therefore locking of the magnetic powder is less likely to occur. Therefore, the pressure in the upper portion of the inductor wiring becomes high, and the magnetic powder flows to a region where there is no inductor wiring, and as a result, the packing rate of the magnetic powder in the upper portion of the inductor wiring is reduced, and the non-oxidized region can be formed in the upper portion of the inductor wiring.

[0197] In addition, the magnetic layer can be press-molded on the inductor wiring, the magnetic layer in the upper portion of the inductor wiring can be made into a convex shape, and the polishing load can be adjusted when polishing the convex portion of the magnetic layer. Thereby, the magnetic powder of the convex portion is degranulated, and therefore the non-oxidized region can be formed in the upper portion of the inductor wiring.

[0198] Symbol Explanation

[0199] 1, 1A inductor component

[0200] 10, 10A blank

[0201] 10a first main surface

[0202] 10b second main surface

[0203] 10c to 10f first to fourth side surfaces

[0204] 11 first magnetic layer

[0205] 12 2nd magnetic layer

[0206] 13 3rd magnetic layer

[0207] 21 1st inductor wiring

[0208] 21a 1st end portion

[0209] 21b 2nd end portion

[0210] 212 upper surface

[0211] 215 1st directly above portion

[0212] 22 2nd inductor wiring

[0213] 22a 1st end portion

[0214] 22b 2nd end portion

[0215] 222 upper surface

[0216] 225 2nd directly above portion

[0217] 31 1st columnar wiring (vertical wiring)

[0218] 32 2nd columnar wiring (vertical wiring)

[0219] 33 3rd columnar wiring (vertical wiring)

[0220] 41 1st external terminal

[0221] 42 2nd external terminal

[0222] 43 3rd external terminal

[0223] 61 insulating layer

[0224] 100 magnetic powder

[0225] 101 resin

[0226] 102 oxide film

[0227] 201 1st lead-out wiring

[0228] 202 2nd lead-out wiring

[0229] R1 oxidized region

[0230] R2 non-oxidized region

[0231] Z1 overlapping region

[0232] Z2 non-overlapping region

Claims

1. An inductor component comprising: The blank contains magnetic powder and has a first main surface and a second main surface; Inductor wiring is disposed within the blank body; A first vertical wiring is disposed within the blank body, connected to the first end of the inductor wiring, and extends to the first main surface; A second vertical wiring is disposed within the blank body, connected to the second end of the inductor wiring, and extends to the first main surface; The first external terminal is connected to the first vertical wiring and is exposed on the first main surface; as well as The second external terminal is connected to the second vertical wiring and is exposed on the first main surface; The magnetic powder is mainly composed of Fe. The first main surface has multiple oxidized areas where the oxide film formed by the oxidation of the magnetic powder is exposed, and multiple non-oxidized areas where the magnetic powder is exposed. The second main surface has the oxidation region. The area of ​​the oxidized region on the second main surface is greater than the area of ​​the oxidized region on the first main surface.

2. The inductor component according to claim 1, wherein, The blank contains a resin containing the magnetic powder. The magnetic powder in the oxidized region comprises magnetic powder that is in contact with the resin through the oxide film.

3. The inductor component according to claim 1, wherein, The blank contains a resin containing the magnetic powder. The magnetic powder in the oxidized region comprises magnetic powder that is in direct contact with the resin.

4. The inductor component according to any one of claims 1 to 3, wherein, Compared to the non-oxidized region, the oxidized region has a higher reflectance at wavelengths of 600nm to 800nm ​​compared to the reflectance at wavelengths less than 600nm.

5. The inductor component according to any one of claims 1 to 3, wherein, The oxide film is formed on the cut surface of the magnetic powder.

6. The inductor component according to any one of claims 1 to 3, wherein, Viewed from a direction orthogonal to the first main surface, the first main surface has an overlapping region that overlaps with the inductor wiring located closest to the first main surface, and the oxide region is located in the overlapping region.

7. The inductor component according to any one of claims 1 to 3, wherein, Viewed from a direction orthogonal to the first main surface, the first main surface has an overlapping region that overlaps with the inductor wiring located closest to the first main surface, and the oxide region is located in a non-overlapping region outside the overlapping region of the first main surface.

8. The inductor component according to any one of claims 1 to 3, wherein, The thickness of the oxide film is less than the D50 of the particle size of the magnetic powder.

9. The inductor component according to any one of claims 1 to 3, wherein, The second main surface has the oxidation region. The oxide film on the second main surface is thinner than the oxide film on the first main surface.

10. The inductor component according to any one of claims 1 to 3, wherein, The oxidation region is only located on the first main surface.

11. The inductor component according to any one of claims 1 to 3, wherein, The blank has a plurality of side surfaces located between the first main surface and the second main surface and connecting the first main surface and the second main surface. The oxidation region is only located on the first main surface and at least one of the side surfaces.

12. The inductor component according to any one of claims 1 to 3, wherein, The blank has a side surface located between the first main surface and the second main surface, connecting the first main surface and the second main surface. It further includes a first lead-out wiring that is connected to the first end of the inductor wiring and exposed from the side. The exposed side of the first lead wire has the oxide region.

13. The inductor component according to any one of claims 1 to 3, wherein, The inductor has multiple wirings. Multiple inductor wirings are arranged on the same plane parallel to the first main surface and electrically separated from each other.

14. The inductor component according to any one of claims 1 to 3, wherein, The blank has a portion located directly above the upper surface between the first main surface side of the inductor wiring and the first main surface. The particle size D50 of the magnetic powder is more than 1 / 10 of the thickness of the upper portion and less than twice the thickness of the upper portion. The thickness of the blank is less than 300 μm.

15. The inductor component according to claim 6, wherein, The particle size D50 of the magnetic powder in the overlapping region is greater than the particle size D50 of the magnetic powder in the non-overlapping region outside the overlapping region of the first main surface.

16. The inductor component according to claim 15, wherein, The wt% of Fe in the oxidized region is greater than the wt% of Fe in the non-oxidized region.

17. The inductor component according to any one of claims 1 to 3, wherein, The blank has multiple magnetic layers stacked in a direction orthogonal to the first main surface. The magnetic layer that contacts the inductor wiring is configured along a portion of the outline of the inductor wiring.

18. The inductor component according to any one of claims 1 to 3, wherein, The particle size D50 of the magnetic powder in the oxidized region is greater than that of the magnetic powder in the non-oxidized region.

19. The inductor component according to any one of claims 1 to 3, wherein, The first main surface has an oxidized region on a plurality of magnetic powders having an Fe content of 65 wt% or more and an O content of 24 wt% or more, as well as a plurality of non-oxidized regions on which the magnetic powders are exposed.

Images