inductor component

Abstract

Provided is an inductor component that suppresses short-circuiting with other electronic components and suppresses a decrease in unit strength and a decrease in inductance. The inductor component includes: a unit body that contains magnetic powder and has a first main surface, a second main surface, and a side surface connecting the first main surface and the second main surface; an inductor wiring provided in the unit body; a first vertical wiring provided in the unit body, connected to a first end portion of the inductor wiring, and extending to the first main surface; a second vertical wiring provided in the unit 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 on the first main surface; and a second external terminal connected to the second vertical wiring and exposed on the first main surface. The magnetic powder has Fe as a main component, and the side surface has a plurality of oxidation regions in which an oxide film in which the magnetic powder is oxidized is exposed and a plurality of non-oxidation regions in which the magnetic powder is exposed.

Description

Technical Field

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

[0002] As a conventional inductor component, the inductor component described in Japanese Patent Application Publication No. 2020-145399 (Patent Document 1) can be cited as an example. The inductor component includes: a unit body containing metallic magnetic powder, first and second coil portions disposed inside the unit 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. Furthermore, the entire surface of the inductor component is provided with an insulating layer obtained by oxidizing the metallic magnetic powder, which prevents short circuits between the inductor component and other electronic components.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-145399 Summary of the Invention

[0006] However, the existing inductor components described above have the following problems.

[0007] Oxidized metallic magnetic powder expands, thus weakening the adhesion between the unit cell and the metallic magnetic powder and reducing the strength of the unit cell. Furthermore, there is the issue of oxidized metallic magnetic powder detaching from the unit cell, reducing the amount of metallic magnetic powder and consequently decreasing the inductance.

[0008] Therefore, the present invention provides an inductor component that can suppress short circuits with other electronic components and suppress the reduction of unit strength and inductance.

[0009] To solve the above-mentioned problems, an inductor component according to one aspect of the present invention includes:

[0010] The unit contains magnetic powder and has a first main surface and a second main surface, as well as a side surface connecting the first main surface and the second main surface.

[0011] The inductor wiring is located within the aforementioned unit.

[0012] A first vertical wiring is disposed within the aforementioned unit body, connected to the first end of the aforementioned inductor wiring, and extends to the aforementioned first main surface.

[0013] A second vertical wiring is disposed within the aforementioned unit body, connected to the first end of the aforementioned inductor wiring, and extends to the aforementioned second main surface.

[0014] The first external terminal is connected to the first vertical wiring and is exposed on the first main surface.

[0015] The second external terminal is connected to the second vertical wiring described above and is exposed on the first main surface described above;

[0016] The magnetic powder mentioned above is mainly composed of Fe.

[0017] The aforementioned side has multiple oxidized regions where the oxide film of the aforementioned magnetic powder is oxidized is exposed, and multiple non-oxidized regions where the aforementioned magnetic powder is exposed.

[0018] Here, the oxidized region refers to the region where Fe content is 65 wt% or more and O content is 24 wt% or more, and the non-oxidized region refers to the region where Fe content is 65 wt% or more and O content is less than 24 wt%.

[0019] Increasing the mounting density of components leads to shorter distances between them, resulting in external terminals of adjacent components contacting the side of the unit body. In this case, there is a risk of short circuits occurring due to the magnetic powder. According to the above method, by providing an oxide region on the side of the unit body, the resistance of the magnetic powder can be increased, suppressing short circuits. Furthermore, by providing a non-oxide region on the side of the unit body, the reduction in unit body strength and inductance can be suppressed.

[0020] In one embodiment of the inductor component, preferably:

[0021] The aforementioned unit cell contains a resin containing the aforementioned magnetic powder.

[0022] The magnetic powder in the aforementioned oxide region comprises magnetic powder that comes into contact with the aforementioned resin through the aforementioned oxide film.

[0023] According to the above embodiments, the magnetic powder in the oxide region comes into contact with the resin through the oxide film, thus enabling more effective suppression of short circuits.

[0024] In one embodiment of the inductor component, preferably:

[0025] The aforementioned unit cell contains a resin containing the aforementioned magnetic powder.

[0026] The magnetic powder in the aforementioned oxidized region comprises magnetic powder that is in direct contact with the aforementioned resin.

[0027] According to the above embodiments, the magnetic powder in the oxidation region is in direct contact with the resin. Therefore, the adhesion between the magnetic powder and the resin is improved, which can more effectively suppress the reduction of unit strength and inductance.

[0028] In one embodiment of the inductor component, preferably:

[0029] Compared with the non-oxidized region, the reflectance of the oxidized region at wavelengths of 600nm to 800nm ​​is in a greater proportion than that at wavelengths less than 600nm.

[0030] According to the above embodiment, the oxidized region reflects red more strongly than the non-oxidized region. Therefore, the oxidized region is visible as red (warm color), making it easy to determine the formation of the oxidized region and confirm whether it has short-circuit withstand capability from its appearance.

[0031] In one embodiment of the inductor component, preferably:

[0032] The oxide film is formed on the cross section of the magnetic powder.

[0033] According to the above embodiment, when the thickness of the unit body is reduced by grinding, the magnetic powder is cut off and the cross-section of the magnetic powder is exposed. However, an oxide film is formed on the cross-section of the magnetic powder, thereby improving short-circuit withstand capability.

[0034] In one embodiment of the inductor component, preferably:

[0035] The thickness of the oxide film is less than the D50 particle size of the magnetic powder.

[0036] According to the above embodiments, if oxidation is carried out excessively, it will cause problems such as a decrease in the strength of the unit and the detachment of magnetic powder. However, since the oxide film is thinner than a single magnetic powder particle, the above problems can be avoided.

[0037] In one embodiment of the inductor component, preferably:

[0038] The inductor wiring described above has a first lead-out portion, which is connected to the first end and exposed from the side.

[0039] According to the above embodiment, by providing the first lead-out portion, strength can be ensured when the inductor component is monolithically manufactured and when the unit body is cut, thereby improving the yield rate during manufacturing.

[0040] The exposed side of the first lead has an oxide region; therefore, when multiple inductor wirings are provided, the insulation resistance between adjacent first leads on the side can be increased. Furthermore, when multiple inductor components are arranged, the insulation resistance between the first leads of adjacent inductor components can be increased.

[0041] In one embodiment of the inductor component, preferably:

[0042] The aforementioned inductor wiring consists of multiple components.

[0043] Multiple inductor wirings are arranged on the same plane parallel to the first main surface mentioned above, and electrically isolated from each other.

[0044] According to the above implementation method, an inductor array can be constructed, and the inductance density can be increased.

[0045] In one embodiment of the inductor component, preferably:

[0046] The aforementioned inductor wiring consists of multiple components.

[0047] Multiple inductor wirings are arranged in a direction orthogonal to the first main plane mentioned above.

[0048] According to the above implementation method, the inductance density can be increased.

[0049] In one embodiment of the inductor component, preferably:

[0050] It further includes an insulating layer disposed on the aforementioned first main surface.

[0051] According to the above embodiment, a short circuit between the first external terminal and the second external terminal can be suppressed.

[0052] In one embodiment of the inductor component, preferably:

[0053] The first main surface described above has the aforementioned oxidized region and the aforementioned non-oxidized region.

[0054] According to the above embodiment, short circuits are suppressed by the magnetic powder on the first main surface between the first external terminal and the second external terminal through the oxidized region, and the reduction in unit strength and inductance can be suppressed by the non-oxidized region.

[0055] In one embodiment of the inductor component, preferably:

[0056] The aforementioned side surface has a first region extending from the first main surface in a direction orthogonal to the first main surface, and a second region excluding the first region.

[0057] The D50 particle size of the magnetic powder in the second region is larger than that of the magnetic powder in the first region.

[0058] In the aforementioned side view, the area of ​​the non-oxidized region is larger than that of the second region in the first region, and the area of ​​the oxidized region is larger than that of the first region in the second region.

[0059] Here, the "specified range" is set within a range shorter than the wiring length of the first vertical wiring. In addition, the "D50 particle size of the magnetic powder in the first region" and the "D50 particle size of the magnetic powder in the second region" can be measured by observing the side.

[0060] According to the above embodiment, the magnetic powder with a larger particle size is disposed around the inductor wiring, thus ensuring inductance. Conversely, the magnetic powder with a smaller particle size is contained in the first main surface and disposed in a first region within a predetermined range from the first main surface. The contact area between the particles of the smaller magnetic powder is reduced. Therefore, short circuits through the magnetic powder in the first region can be suppressed. Furthermore, in the side surface, the second region has a larger oxide area than the first region, thus short circuits through the magnetic powder in the second region can be suppressed.

[0061] In one embodiment of the inductor component, preferably:

[0062] The aforementioned unit cell has multiple magnetic layers stacked in a direction orthogonal to the first principal plane.

[0063] The magnetic layer connected to the inductor wiring is disposed along a portion of the outline of the inductor wiring.

[0064] According to the above implementation, a magnetic layer can be arranged around the inductor wiring to ensure inductance.

[0065] In one embodiment of the inductor component, preferably:

[0066] The D50 particle size of the magnetic powder in the oxidized region is larger than that of the magnetic powder in the non-oxidized region.

[0067] According to the above embodiments, magnetic powder with large particle size is easily oxidized and can easily form oxidized regions.

[0068] In one embodiment of the inductor component, preferably:

[0069] The amount of Fe in the oxidized region is greater than that in the non-oxidized region.

[0070] According to the above implementation method, the amount of Fe element in the oxidation region is large. Therefore, a large amount of Fe element can be arranged around the inductor wiring to ensure the inductance.

[0071] In one embodiment of the inductor component, preferably:

[0072] The aforementioned side also has a recess.

[0073] According to the above embodiment, the surface area of ​​the side is increased, thus improving heat dissipation.

[0074] In addition, to solve the above-mentioned problems, an inductor component according to another embodiment of the present invention includes:

[0075] The unit contains magnetic powder and has a first main surface and a second main surface, as well as a side surface connecting the first main surface and the second main surface.

[0076] The inductor wiring is located within the aforementioned unit.

[0077] A first vertical wiring is disposed within the aforementioned unit body, connected to the first end of the aforementioned inductor wiring, and extends to the aforementioned first main surface.

[0078] A second vertical wiring is disposed within the aforementioned unit body, connected to the first end of the aforementioned inductor wiring, and extends to the aforementioned second main surface.

[0079] The first external terminal is connected to the first vertical wiring and exposed on the first main surface; the second external terminal is connected to the second vertical wiring and exposed on the first main surface.

[0080] The aforementioned magnetic powder is mainly composed of Fe.

[0081] The aforementioned side has an oxidized region on the aforementioned magnetic powder where Fe content is 65 wt% or more and O content is 24 wt% or more, as well as a non-oxidized region on the aforementioned magnetic powder that is exposed.

[0082] Increasing the mounting density of components can lead to shorter distances between components, resulting in external terminals of adjacent components contacting the side of the unit body. In this case, there is a risk of short circuits due to the magnetic powder. According to the above embodiment, by providing an oxide region on the side of the unit body, the resistance of the magnetic powder can be increased, suppressing short circuits. Furthermore, by providing a non-oxidized region on the side of the unit body, the reduction in unit body strength and inductance can be suppressed.

[0083] An inductor component according to one aspect of the present invention can suppress short circuits with other electronic components and suppress the reduction of unit strength and inductance. Attached Figure Description

[0084] Figure 1 This is a plan view showing the first embodiment of the inductor component.

[0085] Figure 2A for Figure 1 A-A cross-sectional view.

[0086] Figure 2B for Figure 1 B-B cross-sectional view.

[0087] Figure 3 for Figure 2B An enlarged view of part A.

[0088] Figure 4A An explanatory diagram illustrating the manufacturing method of an inductor component.

[0089] Figure 4B An explanatory diagram illustrating the manufacturing method of an inductor component.

[0090] Figure 4C An explanatory diagram illustrating the manufacturing method of an inductor component.

[0091] Figure 4D An explanatory diagram illustrating the manufacturing method of an inductor component.

[0092] Figure 4E An explanatory diagram illustrating the manufacturing method of an inductor component.

[0093] Figure 4F An explanatory diagram illustrating the manufacturing method of an inductor component.

[0094] Figure 4G An explanatory diagram illustrating the manufacturing method of an inductor component.

[0095] Figure 4H An explanatory diagram illustrating the manufacturing method of an inductor component.

[0096] Figure 4I An explanatory diagram illustrating the manufacturing method of an inductor component.

[0097] Figure 5A This is a coordinate graph showing the amount of Fe [wt%] in the oxidized and non-oxidized regions in Examples 1 to 3.

[0098] Figure 5B This is a coordinate graph showing the amount of O element [wt%] in the oxidized and non-oxidized regions in Examples 1 to 3.

[0099] Figure 6 This is a plan view showing the second embodiment of the inductor component.

[0100] Figure 7 for Figure 6 A-A cross-sectional view.

[0101] Figure 8 for Figure 7 An enlarged view of part A.

[0102] Figure 9A An explanatory diagram illustrating the manufacturing method of an inductor component.

[0103] Figure 9BAn explanatory diagram illustrating the manufacturing method of an inductor component.

[0104] Figure 9C An explanatory diagram illustrating the manufacturing method of an inductor component.

[0105] Figure 9D An explanatory diagram illustrating the manufacturing method of an inductor component.

[0106] Figure 9E An explanatory diagram illustrating the manufacturing method of an inductor component.

[0107] Figure 9F An explanatory diagram illustrating the manufacturing method of an inductor component.

[0108] Figure 9G An explanatory diagram illustrating the manufacturing method of an inductor component.

[0109] Figure 9H An explanatory diagram illustrating the manufacturing method of an inductor component.

[0110] Figure 9I An explanatory diagram illustrating the manufacturing method of an inductor component.

[0111] Figure 9J An explanatory diagram illustrating the manufacturing method of an inductor component.

[0112] Figure 9K An explanatory diagram illustrating the manufacturing method of an inductor component.

[0113] Figure 9L An explanatory diagram illustrating the manufacturing method of an inductor component.

[0114] Figure 9M An explanatory diagram illustrating the manufacturing method of an inductor component.

[0115] Figure 10 This is an image showing a cross-section of the unit body according to the third embodiment.

[0116] Figure 11 An explanatory diagram illustrating the manufacturing method of an inductor component.

[0117] Symbol Explanation

[0118] 1, 1A Inductor Component

[0119] 10,10A unit

[0120] 10a 1st main side

[0121] 10b 2nd main side

[0122] 10c~10f Side views 1 to 4

[0123] 11 First magnetic layer

[0124] 12 Second magnetic layer

[0125] 13 Third magnetic layer

[0126] 15 Second Insulation Layer

[0127] 21, 21A First Inductor Wiring

[0128] 21a First end (inner circumferential end)

[0129] 21b Second end (outer peripheral end)

[0130] Wiring of the second inductor in 22, 22A

[0131] 22a First end (inner circumferential end)

[0132] 22b Second end (outer peripheral end)

[0133] 25-hole wiring

[0134] 31. First column of wiring (vertical wiring)

[0135] 32. Second column wiring (vertical wiring)

[0136] 33. Third column wiring (vertical wiring)

[0137] 41, 41A First External Terminal

[0138] 42, 42A 2nd external terminal

[0139] 43 3rd external terminal

[0140] 50 Third insulating layer (coating)

[0141] 51 First vertical cabling

[0142] 52 Second vertical wiring

[0143] 61 Second Insulation Layer

[0144] 71 First Insulation Layer

[0145] 81 First connection wiring

[0146] 82 Second connection wiring

[0147] 100 magnetic powder

[0148] 101 Resin

[0149] 102 oxide film

[0150] 201 First Outline Wiring

[0151] 202 No. 2 Outlet Wiring

[0152] Area A1, Section 1

[0153] Area A2, Zone 2

[0154] C concavity

[0155] The length of region L in the Z direction

[0156] R1 oxidation region

[0157] R2 non-oxidized region Detailed Implementation

[0158] The inductor component, as one embodiment of the present invention, will now be described in detail with reference to the illustrated embodiments. It should be noted that the illustrations are only partial and schematic, and may not reflect actual dimensions or ratios.

[0159] <First Embodiment>

[0160] (constitute)

[0161] Figure 1 This is a plan view showing the first embodiment of the inductor component. Figure 2A for Figure 1 A-A cross-sectional view. Figure 2B for Figure 1 B-B cross-sectional view.

[0162] The inductor component 1 is, for example, a component with an overall rectangular shape, and can be mounted on electronic devices such as computers, DVD players, digital cameras, TVs, mobile phones, and automotive electronics. However, the shape of the inductor component 1 is not particularly limited, and it can also be cylindrical, prismatic, conical, or pyramidal.

[0163] like Figure 1 , Figure 2A and Figure 2B As shown, the inductor component 1 includes: a unit body 10, a first inductor wiring 21 and a second inductor wiring 22 disposed within the unit body 10, a first columnar wiring 31, a second columnar wiring 32 and a third columnar wiring 33 disposed within the unit body 10 with their end faces exposed from the first main surface 10a of the unit body 10, and a first external terminal 41, a second external terminal 42 and a third external terminal 43 exposed in the first main surface 10a of the unit body 10. Figure 1 For convenience, the first to third external terminals 41 to 43 are represented by double-dotted lines.

[0164] In the figure, the thickness direction of inductor component 1 is defined as the Z direction, the direction along the Z direction is defined as the top side, and the direction against the Z direction is defined as the bottom side. In a plane orthogonal to the Z direction of inductor component 1, the length direction of inductor component 1 is defined as the X direction, and the width direction of inductor component 1 is defined as the Y direction.

[0165] The unit body 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 located between the first main surface 10a and the second main surface 10b and connecting the first main surface 10a and the second main surface 10b.

[0166] The first principal surface 10a and the second principal surface 10b are arranged in the Z direction and are opposite to each other, with the first principal surface 10a arranged in the same direction as the Z direction and the second principal surface 10b arranged in the opposite direction to the Z direction. The first side surface 10c and the second side surface 10d are arranged in the X direction and are opposite to each other, with the first side surface 10c arranged in the opposite direction to the X direction and the second side surface 10d arranged in the same direction as the X direction. The third side surface 10e and the fourth side surface 10f are arranged in the Y direction and are opposite to each other, with the third side surface 10e arranged in the opposite direction to the Y direction and the fourth side surface 10f arranged in the same direction as the Y direction.

[0167] The unit cell 10 has a first magnetic layer 11 and a second magnetic layer 12 stacked sequentially along the Z-direction. The first magnetic layer 11 and the second magnetic layer 12 each contain magnetic powder and a resin containing the magnetic powder. The resin is, for example, an organic insulating material formed from epoxy, phenolic, liquid crystal polymer, polyimide, acrylic, or mixtures thereof. The magnetic powder is, for example, an FeSi alloy such as FeSiCr, an FeCo alloy, an Fe alloy such as NiFe, or an amorphous alloy thereof. Therefore, compared to a magnetic layer composed of ferrite, the magnetic powder can be used to improve DC superposition characteristics, and the resin provides insulation between the magnetic powder particles, thus reducing losses (iron losses) at high frequencies.

[0168] 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 exists in the reverse Z direction of the first inductor wiring 21 and the second inductor wiring 22, and the second magnetic layer 12 exists in the Z direction and in the direction orthogonal to the Z direction of the first inductor wiring 21 and the second inductor wiring 22.

[0169] When viewed from the Z direction, the wiring 21 of the first inductor extends in a straight line along the X direction. When viewed from the Z direction, a portion of the wiring 22 of the second inductor extends in a straight line along the X direction, and the other portion extends in a straight line along the Y direction, that is, it extends in an L shape.

[0170] The thickness of the first and second inductor wirings 21 and 22 is preferably 40 μm to 120 μm, for example. As an example of the first and second inductor wirings 21 and 22, the thickness is 35 μm, the wiring width is 50 μm, and the maximum space between the wirings is 200 μm.

[0171] The first inductor wiring 21 and the second inductor wiring 22 are made of conductive materials, such as low-resistance metals like Cu, Ag, Au, and Al. In this embodiment, the inductor component 1 has only one layer of the first and second inductor wirings 21 and 22, which can achieve low backlighting of the inductor component 1. It should be noted that the inductor wiring can be composed of two layers: a seed layer and an electroplated layer. The seed layer can contain Ti or Ni.

[0172] The first end 21a of the first inductor wiring 21 is electrically connected to the first post wiring 31, and the second end 21b of the first inductor wiring 21 is electrically connected to the second post wiring 32.

[0173] That is, the first inductor wiring 21 has pad portions with large line widths at the first and second ends 21a and 21b, and is directly connected to the first and second columnar wirings 31 and 32 in the pad portions.

[0174] The first end 22a of the second inductor wiring 22 is electrically connected to the third post wiring 33, and the second end 22b of the second inductor wiring 22 is electrically connected to the second post wiring 32.

[0175] That is, the second inductor wiring 22 has a pad portion at its first end 22a, and the pad portion is directly connected to the third columnar wiring 33. The second end 22b of the second inductor wiring 22 is common to the second end 21b of the first inductor wiring 21.

[0176] When viewed from the Z direction, the first end 21a of the first inductor wiring 21 and the first end 22a of the second inductor wiring 22 are located on the first side 10c side of the unit body 10. When viewed from the Z direction, the second end 21b of the first inductor wiring 21 and the second end 22b of the second inductor wiring 22 are located on the second side 10d side of the unit body 10.

[0177] The first end 21a of the first inductor wiring 21 and the first end 22a of the second inductor wiring 22 are respectively connected to the first lead wiring 201, which is exposed from the first side 10c. The second end 21b of the first inductor wiring 21 and the second end 22b of the second inductor wiring 22 are connected to the second lead wiring 202, which is exposed from the second side 10d.

[0178] The first lead-out wiring 201 and the second lead-out wiring 202 are wirings connected to the feed line wiring during the additional electroplating process after the shapes of the first and second inductor wirings 21 and 22 are formed during the manufacturing process of the inductor component 1. Through this feed line wiring, additional electroplating can be easily performed on the inductor substrate state before the inductor component 1 is individualized, thus narrowing the distance between the wirings. Furthermore, by performing additional electroplating, the distance between the first and second inductor wirings 21 and 22 is narrowed, thereby improving the magnetic coupling of the first and second inductor wirings 21 and 22. In addition, by providing the first lead-out wiring 201 and the second lead-out wiring 202, strength can be ensured and the yield rate during manufacturing can be improved when the unit body 10 is cut during the monolithization of the inductor component 1.

[0179] The first to third columnar wirings 31 to 33 extend in the Z direction from each inductor wiring 21, 22, penetrating the interior of the second magnetic layer 12. The columnar wirings are equivalent to the "vertical wirings" described in the claims.

[0180] A first columnar wiring 31 extends from the top of the first end 21a of the first inductor wiring 21 to the first main surface 10a of the unit body 10, with the end face of the first columnar wiring 31 exposed from the first main surface 10a of the unit body 10. A second columnar wiring 32 extends from the top of the second end 21b of the first inductor wiring 21 to the first main surface 10a of the unit body 10, with the end face of the second columnar wiring 32 exposed from the first main surface 10a of the unit body 10. A third columnar wiring 33 extends from the top of the first end 22a of the second inductor wiring 22 to the first main surface 10a of the unit body 10, with the end face of the third columnar wiring 33 exposed from the first main surface 10a of the unit body 10.

[0181] Therefore, the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 extend linearly in a direction orthogonal to the first main surface 10a, from the first inductor wiring 21 and the second inductor wiring 22 to the exposed end face of the first main surface 10a. This allows for the connection of the first external terminal 41, the second external terminal 42, the third external terminal 43, the first inductor wiring 21, and the second inductor wiring 22 with a shorter distance, achieving low resistance and high inductance in the inductor component 1. The first to third columnar wirings 31 to 33 are made of a conductive material, for example, the same material as the inductor wirings 21 and 22.

[0182] It should be noted that when the first and second inductor wirings 21 and 22 are covered with an insulating layer made of a non-magnetic material, the first to third columnar wirings 31 to 33 are electrically connected to the first and second inductor wirings 21 and 22 via via wirings that penetrate the insulating layer. The via wirings are conductors with a smaller line width (diameter, cross-sectional area) than the columnar wirings. In this case, the "vertical wiring" described in the claims is composed of via wirings and columnar wirings.

[0183] The first to third external terminals 41 to 43 are disposed on the first main surface 10a of the unit body 10. The first to third external terminals 41 to 43 are formed of conductive materials, such as Cu with low resistance and excellent stress resistance, Ni with excellent corrosion resistance, and Au with excellent solder wettability and reliability, arranged in three layers from the inside to the outside.

[0184] The first external terminal 41 contacts the end face of the unit body 10 of the first columnar wiring 31 exposed from the first main surface 10a, 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 of the unit body 10 of the second columnar wiring 32 exposed from the first main surface 10a, 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, is electrically connected to the third columnar wiring 33, and is electrically connected to the first end 22a of the second inductor wiring 22.

[0185] The undersides of the first inductor wiring 21 and the second inductor wiring 22 are respectively covered by an insulating layer 61. The insulating layer 61 is made of a non-magnetic insulating material, such as an 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.

[0186] Figure 3 for Figure 2B 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. This means that magnetic powder 100 is composed of Fe monomers 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.

[0187] The third side surface 10e of the unit body 10 has: an oxidized region R1 exposed by an oxide film 102 formed by the oxidation of multiple magnetic powders 100, a non-oxidized region R2 exposed by multiple magnetic powders 100, and a recess C. 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 third side surface 10e of the unit body 10 has an oxidized region R1 on the multiple magnetic powders 100 where Fe content is 65 wt% or more and O content is 24 wt% or more, and a non-oxidized region R2 exposed by multiple magnetic powders 100.

[0188] In the compositional analysis of the oxidized region R1 and the non-oxidized region R2, analysis was performed using EDX (energy-dispersive X-ray diffraction) based on the SEM (scanning electron microscope) image of the third side 10e. Specifically, in the SEM image, images were taken at a magnification of 100x (e.g., 300x) for multiple magnetic powders, and point analysis was performed on the oxidized region R1 and the non-oxidized region R2 using EDX, or compositional analysis was performed on only the corresponding regions. Here, as noise, sometimes carbon (C) from the resin component of the magnetic layer, components from the insulating filler, metal components used in vapor deposition, etc., are detected. The composition of the magnetic powder other than these and the oxygen element (O) as the denominator are used to calculate the ratio of the corresponding composition (Fe element, O element). The boundary between the elements contained in the denominator of the magnetic powder composition and the noise is determined by pre-exposing the central part of the unit cell through cross-sectional grinding. The composition that can be detected on the cross-section of the magnetic powder exposed at this cross-section is used as a reference, and the composition that has never been detected except for the oxygen element is considered as noise.

[0189] When the inductor component 1 is monolithically formed, the recess C can be provided by detaching the magnetic powder 100 from the side of the unit body. The inner surface of the recess C is preferably hemispherical. This disperses mechanical stress within the recess, ensuring the strength of the unit body 10. By providing the recess C on the third side surface 10e, the surface area of ​​the third side surface 10e is increased, improving the heat dissipation of the inductor component 1. Therefore, it is preferable to provide the recess C on the third side surface 10e, but it is not necessary. In this case, since the detached magnetic powder 100 is present instead of the recess C, the inductance is increased.

[0190] It should be noted that the above description uses the third side 10e as an example, but the above-mentioned oxidized region R1, non-oxidized region R2 and recess C can be provided on one or more of the first side 10c, the second side 10d, the third side 10e and the fourth side 10f.

[0191] When the mounting density of components is increased, the distance between components becomes shorter, and the external terminals of adjacent components may come into contact with the sides 10c to 10f of the first to fourth sides of the unit body 10. In this case, there is a risk of short circuits occurring through the magnetic powder 100. According to the inductor component 1, by providing the oxide region R1 on the first to fourth sides 10c to 10f of the unit body 10, the resistance of the magnetic powder 100 can be increased, thus suppressing short circuits. In addition, by providing the non-oxidized region R2 on the first to fourth sides 10c to 10f, the reduction in unit body strength and inductance can be suppressed. Furthermore, since the first inductor wiring 21 and the second inductor wiring 22 are in a single layer, the inductor component 1 can be made thinner.

[0192] like Figure 3 As shown, the magnetic powder 100 in the oxide region R1 comprises magnetic powder that is in direct contact with the resin 101. Specifically, the magnetic powder 100 comprises magnetic powder that has not been pre-coated with an oxide film. According to the above configuration, the magnetic powder 100 in the oxide region R1 is in direct contact with the resin 101; therefore, the adhesion between the magnetic powder 100 and the resin 101 is improved, and the reduction in unit strength and inductance can be more effectively suppressed.

[0193] Alternatively, although not illustrated, the magnetic powder 100 in the oxide region R1 may comprise magnetic powder that is in contact with the resin 101 through the oxide film. Specifically, the magnetic powder 100 comprises magnetic powder that has been pre-coated with an oxide film. According to the above configuration, the magnetic powder 100 in the oxide region R1 contacts the resin 101 through the oxide film, thus more effectively suppressing short circuits. Furthermore, the magnetic powder 100 in the oxide region R1 may comprise magnetic powder that is partially coated with an oxide film on the surface of the resin 101, with the remaining portion not coated. That is, the magnetic powder 100 in the oxide region R1 may comprise magnetic powder that is partially in direct contact with the resin 101 and partially in contact with the resin 101 through the oxide film.

[0194] Preferably, compared to the non-oxidized region R2, the reflectance of the oxidized region R1 at wavelengths of 600nm to 800nm ​​is in a greater proportion to the reflectance at wavelengths less than 600nm. Based on this configuration, the oxidized region R1 has greater red reflectance compared to the non-oxidized region R2. Therefore, the oxidized region R1 is visible as red (warm color), and its formation can be easily determined visually or through an inspection device, allowing for confirmation of short-circuit withstand capability.

[0195] Preferably, the oxide film 102 is formed on the cross-section of the magnetic powder 100. According to the above configuration, when the thickness of the unit body 10 is reduced by grinding, the magnetic powder 100 is cut off and the cross-section of the magnetic powder 100 is exposed, but an oxide film 102 is formed on the cross-section of the magnetic powder 100, thereby improving short-circuit withstand capability.

[0196] In this regard, in known magnetic powders, insulation is sometimes improved by coating the surface with organic or inorganic substances such as phosphoric acid or SiO2. By placing such magnetic powder on the outermost surface, the insulation of the chip surface can be improved. However, if a thin inductor component is to be manufactured, the unit body (magnetic layer) needs to be ground to adjust the thickness. In this case, the surface protective film on the surface of the magnetic powder is peeled off, exposing the interior of the magnetic powder, thereby reducing short-circuit withstand capability. Therefore, in this embodiment, by forming an oxide film 102 on the exposed interior of the magnetic powder 100 where insulation withstand capability is reduced, short-circuit withstand capability is improved without unnecessary thickness increase. The oxide film 102 can also be formed on the surface that is not a cross-section of the magnetic powder 100. Furthermore, based on the above, it is conceivable that in the oxidation region R1, the portion of the magnetic powder 100 embedded in the resin 101 is not limited to being covered by an oxide film 102 formed by the oxidation of the magnetic powder 100, but can also be covered by organic or inorganic substances such as phosphoric acid or SiO2.

[0197] Preferably, the thickness of the oxide film 102 is smaller than the D50 particle size of the magnetic powder 100. According to the above configuration, if oxidation is excessive, it will cause problems such as a decrease in the strength of the unit 10 and delamination of the magnetic powder 100. However, since the oxide film 102 is thinner than a single magnetic powder particle 100, this problem can be avoided.

[0198] Here, unless otherwise specified, the D50 particle size of the magnetic powder 100 is determined based on the SEM image of a cross-section of the central portion of the unit cell 10 of the inductor component along its long side. Preferably, the SEM image contains 10 or more magnetic powder particles 100, obtained, for example, at a magnification of 2000x. By obtaining three or more such SEM images from the cross-section, the magnetic powder 100 and other particles are classified using binarization or similar methods. The equivalent circle diameter of each magnetic powder 100 within the SEM image is calculated, and the median diameter (the average diameter) when arranged sequentially according to the size of the equivalent circle diameter is taken as the D50 particle size of the magnetic powder 100. Furthermore, starting from the end with the smallest equivalent circle diameter, the number of particles is accumulated, and the equivalent circle diameter at which the number first exceeds 90% of the total is taken as the D90 particle size of the magnetic powder 100.

[0199] Preferably, the D50 particle size of the magnetic powder 100 in the oxidized region is larger than that of the magnetic powder 100 in the non-oxidized region. Based on this configuration, the larger particle size of the magnetic powder 100 facilitates oxidation, allowing for the easy formation of oxidized regions.

[0200] Preferably, the first lead wire 201 exposed on the first side surface 10c has an oxide region R1. According to the above configuration, when multiple inductor wires 21, 22 are provided, the insulation resistance between adjacent first lead wires 201, 201 in the first side surface 10c can be increased. Furthermore, when multiple inductor components 1 are arranged, the insulation resistance between adjacent first lead wires 201, 201 of the inductor components 1 can be increased. Similarly, the second side surface 10d exposed on the second lead wire 202 can also have an oxide region R1.

[0201] Preferably, there are multiple inductor wirings, and these multiple inductor wirings are arranged on the same plane parallel to the first main surface 10a and electrically separated from each other. Based on the above configuration, an inductor array can be formed, increasing the inductance density.

[0202] Preferably, the first main surface 10a of the unit body 10 has an oxidized region R1 and a non-oxidized region R2. According to the above configuration, the oxidized region R1 allows the magnetic powder 100 of the first main surface 10a to suppress short circuits 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, while the non-oxidized region R2 allows the reduction in strength and inductance of the unit body 10 to be suppressed.

[0203] (Manufacturing method)

[0204] Next, the manufacturing method of inductor component 1 will be described. Figures 4A to 4I Corresponding to Figure 1 B-B section ( Figure 2B ).

[0205] like Figure 4A As shown, a substrate 70 is prepared. The substrate 70 is made of inorganic materials such as ceramic, glass, or silicon. A first insulating layer 71 is coated on the main surface of the substrate 70, and the first insulating layer 71 is cured.

[0206] like Figure 4B As shown, a second insulating layer 61 is coated on the first insulating layer 71, a specified pattern is formed using photolithography, and then cured.

[0207] like Figure 4CAs shown, a seed layer (not shown) is formed on the first insulating layer 71 and the second insulating layer 61 by a known method such as sputtering or vapor deposition. Then, a dry film resist (DFR) 75 is attached, and a predetermined pattern is formed on the DFR 75 using photolithography. The predetermined pattern consists of through-holes corresponding to the positions of the first inductor wiring 21 and the second inductor wiring 22 on the second insulating layer 61.

[0208] like Figure 4D As shown, the seed layer is powered, and the first inductor wiring 21 and the second inductor wiring 22 are formed on the second insulating layer 61 using an electrolytic plating method. Then, the DFR 75 is stripped, and the seed layer is etched. Thus, the first inductor wiring 21 and the second inductor wiring 22 are formed on the main surface of the substrate 70.

[0209] like Figure 4E As shown, the DFR75 is attached again, and a specified pattern is formed on the DFR75 using photolithography. The specified pattern consists of through holes corresponding to the positions of the first pillar wiring 31, the second pillar wiring 32, and the third pillar wiring 33 on the first inductor wiring 21 and the second inductor wiring 22.

[0210] like Figure 4F As shown, electroplating is used to form the first pillar wiring 31, the second pillar wiring 32, and the third pillar wiring 33 on the first inductor wiring 21 and the second inductor wiring 22. Afterwards, the DFR75 is stripped. It should be noted that a seed layer can also be used in the electroplating process; in this case, the seed layer needs to be etched. Alternatively, the seed layer formed during the formation of the first inductor wiring 21 and the second inductor wiring 22 can be left unetched and powered through it, thereby forming the first pillar wiring 31, the second pillar wiring 32, and the third pillar wiring 33; in this case, the seed layer still needs to be etched.

[0211] like Figure 4G As shown, the magnetic sheet that will become the second magnetic layer 12 is pressed from above the main surface of the substrate 70 toward the first inductor wiring 21 and the second inductor wiring 22, thereby covering 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. Then, the top 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 sometimes, to reduce degradation caused by the environmental load on the magnetic powder, a surface protective film made of inorganic materials such as glass or silicon, or resin, can be used. Thus, when the magnetic powder is covered by a surface protective film, the surface protective film is peeled off by grinding, thereby oxidizing the surface of the magnetic powder.

[0212] 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. Then, other magnetic sheets serving as the first magnetic layer 11 are pressed from below the first inductor wiring 21 and the second inductor wiring 22 toward the first inductor wiring 21 and the second inductor wiring 22, thereby 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.

[0213] like Figure 4I As shown, the inductor component 1 is monolithically formed using a cutting line D. During or after monolithization, oxidized and non-oxidized regions are formed on the side of the unit cell; preferably, a recess is formed during monolithization. For example, oxidized and non-oxidized regions can be formed on the side of the unit cell by water washing and drying during monolithization. Specifically, during water washing during monolithization, the side of the unit cell also comes into contact with water. Then, by adjusting the water washing time or drying time, for example, an oxide film can be formed on the large-particle-size magnetic powder, easily forming oxidized and non-oxidized regions. Alternatively, after monolithization of the inductor component 1, the side of the unit cell can be washed with water while removing impurities, forming oxidized and non-oxidized regions. In this case, by adjusting the water washing time or drying time, for example, an oxide film can also be formed on the large-particle-size magnetic powder, easily forming oxidized and non-oxidized regions. The recess can be formed, for example, by controlling the shearing speed during monolithization, the rotation speed of the cutting blade, etc., to promote the granulation of the magnetic powder.

[0214] Subsequently, an electroless plating process is used to form a metal film on the columnar wirings 31-33, thereby forming the first external terminal 41, the second external terminal 42, and the third external terminal 43. Thus, as... Figure 2B As shown, inductor component 1 is manufactured.

[0215] (Example)

[0216] Next, in Examples 1, 2, and 3, the amounts of Fe and O elements in the oxidized and non-oxidized regions were determined. Figure 5A This is a coordinate graph showing the amount of Fe [wt%] in the oxidized and non-oxidized regions in Examples 1 to 3. Figure 5B This is a coordinate graph showing the amount of O element [wt%] in the oxidized and non-oxidized regions in Examples 1 to 3.

[0217] In Example 1, the magnetic powder was composed of FeSi, and the D50 particle size was 15 μm. In Example 2, the magnetic powder was composed of FeSi. If the Fe content in Example 1 was set to 1, then the Fe content in Example 2 was 1.2, and the D50 particle size was 16 μm. In Example 3, the magnetic powder was composed of FeSiCr. If the Fe content in Example 1 was set to 1, then the Fe content in Example 3 was 0.9, and the D50 particle size was 3 μm.

[0218] like Figure 5A As shown, in Example 1, the Fe content in the oxidized region was 72 wt%, and the Fe content in the non-oxidized region was 75 wt%. In Example 2, the Fe content in the oxidized region was 71 wt%, and the Fe content in the non-oxidized region was 90 wt%. In Example 3, the Fe content in the oxidized region was 73 wt%, and the Fe content in the non-oxidized region was 70 wt%.

[0219] like Figure 5B As shown, in Example 1, the amount of O in the oxidized region was 24 wt%, and the amount of O in the non-oxidized region was 18 wt%. In Example 2, the amount of O in the oxidized region was 26 wt%, and the amount of O in the non-oxidized region was 8 wt%. In Example 3, the amount of O in the oxidized region was 27 wt%, and the amount of O in the non-oxidized region was 23 wt%. Figure 5B In the diagram, the position of 24wt% is indicated by a dashed line.

[0220] Therefore, in the oxidized region, Fe content is 65 wt% or more and O content is 24 wt% or more. In the non-oxidized region, Fe content is 65 wt% or more and O content is less than 24 wt%.

[0221] <Second Implementation>

[0222] Figure 6 This is a plan view showing the second embodiment of the inductor component. Figure 7 for Figure 6 The A-A cross-sectional view is shown. The third embodiment differs from the first embodiment in the configuration of the inductor wiring, vertical wiring, and external terminals. This difference in configuration is explained below. It should be noted that in the third embodiment, the same symbols as in the first embodiment represent the same configurations, therefore, their description is omitted.

[0223] like Figure 6 and Figure 7As shown, the inductor component 1A includes a unit body 10, a first inductor wiring 21A and a second inductor wiring 22A, an insulating layer 15, a first vertical wiring 51 (first columnar wiring 31, via wiring 25) and a second vertical wiring 52 (second columnar wiring 32, second connecting wiring 82, via wiring 25), a first external terminal 41A and a second external terminal 42A, and a coating film 50. The first inductor wiring 21A and the second inductor wiring 22A, the insulating layer 15, and the first vertical wiring 51 and the second vertical wiring 52 are disposed within the unit body 10. The first and second external terminals 41A and 42A and the coating film 50 are disposed on the first main surface 10a of the unit body 10. The unit body 10 has a first magnetic layer 11 and a second magnetic layer 12 sequentially stacked along the Z-direction.

[0224] The first inductor wiring 21A is disposed above the second inductor wiring 22A and extends in a spiral shape along the first main surface 10a of the unit body 10. The number of turns of the first inductor wiring 21A is preferably greater than one turn. This improves inductance. For example, viewed from the Z direction, the first inductor wiring 21A is wound in a clockwise spiral shape from the outer peripheral end 21b toward the inner peripheral end 21a. The conductive material of the first inductor wiring 21A is the same as the conductive material of the first inductor wiring 21 according to the first embodiment. The outer peripheral end 21b corresponds to the "first end" as described in the scope of the claims.

[0225] The second inductor wiring 22A is a spiral-shaped wiring extending along the first main surface 10a of the unit body 10. The number of turns of the second inductor wiring 22A is preferably greater than one turn. This improves inductance. Viewed from the Z direction, the second inductor wiring 22A is wound in a clockwise spiral shape from the inner peripheral end 22a to the outer peripheral end 22b. The second inductor wiring 22A is disposed between the first inductor wiring 21A and the first magnetic layer 11. Thus, the first inductor wiring 21A and the second inductor wiring 22A are each arranged along a direction orthogonal to the first main surface 10a (Z direction). The conductive material of the second inductor wiring 22A is the same as the conductive material of the first inductor wiring 21 according to the first embodiment. The outer peripheral end 22b corresponds to the "second end" as described in the claims.

[0226] The outer peripheral end 21b of the first inductor wiring 21A is connected to the first external terminal 41A via the first vertical wiring 51 (via wiring 25 and first column wiring 31) on the upper side of its outer peripheral end 21b. The inner peripheral end 21a of the first inductor wiring 21A is connected to the inner peripheral end 22a of the second inductor wiring 22A via a via wiring (not shown) on the lower side of its inner peripheral end 21a.

[0227] The outer peripheral end 22b of the second inductor wiring 22A is connected to the second external terminal 42 via the second vertical wiring 52 (second column wiring 32, second connecting wiring 82 and via wiring 25) on the upper side of its outer peripheral end 22b. With the above configuration, the first inductor wiring 21A and the second inductor wiring 22A are connected in series and electrically connected to the first external terminal 41 and the second external terminal 42.

[0228] It should be noted that in this embodiment, the first connecting wire 81 is disposed on the same layer as the second inductor wire 22A. The first connecting wire 81 is disposed below the outer peripheral end 21b of the first inductor wire 21A (opposite to the Z direction), and is connected only to the lower surface of the first inductor wire 21A via the via wire 25. The first connecting wire 81 is not connected to the second inductor wire 22A and is electrically independent. By providing the first connecting wire 81, the outer peripheral end 21b of the first inductor wire 21A can be disposed on the same layer as the winding portion of the first inductor wire 21A, which can suppress wire breakage and the like.

[0229] The insulating layer 15 is a film-like layer formed on the first magnetic layer 11, and at least covers the first and second inductor wirings 21A and 22A. Specifically, the insulating layer 15 covers the entire bottom and side surfaces of the first and second inductor wirings 21A and 22A, and covers the top surface of the first and second inductor wirings 21A and 22A except for the portion connected to the via wiring 25. The insulating layer 15 has holes at positions corresponding to the inner periphery of the first and second inductor wirings 21A and 22A. The thickness of the insulating layer 15 between the top surface of the first magnetic layer 11 and the bottom surface of the second inductor wiring 22A is, for example, 10 μm or less.

[0230] The insulating layer 15 is made of an insulating material that does not contain magnetic materials, such as epoxy resin, phenolic resin, polyimide resin, or other resin materials. It should be noted that the insulating layer 15 may contain fillers such as silicon dioxide, in which case the strength, processability, and electrical properties of the insulating layer 15 can be improved.

[0231] The bottom surfaces of the first magnetic layer 11, the second magnetic layer 12, and the insulating layer 15 are in close contact. The second magnetic layer 12 is disposed above the first magnetic layer 11. The first and second inductor wirings 21A and 22A are disposed between the first magnetic layer 11 and the second magnetic layer 12. The second magnetic layer 12 not only covers the top of the first and second inductor wirings 21A and 22A, but also covers the inner periphery of the first and second inductor wirings 21A and 22A, which are formed along the insulating layer 15.

[0232] The first vertical wiring 51 is made of conductive material and extends in the Z direction from the first inductor wiring 21A, penetrating the interior of the second magnetic layer 12. The first vertical wiring 51 includes: a via wiring 25 extending upward from the top of the outer peripheral end 21b of the first inductor wiring 21A, and a first columnar wiring 31 extending upward from the via wiring 25 and penetrating the interior of the first magnetic layer 11.

[0233] The second vertical wiring 52 is made of a conductive material and extends in the Z direction from the second inductor wiring 22A, penetrating the interior of the insulating layer 15 and the second magnetic layer 12. The second vertical wiring 52 includes: a via wiring 25 extending upwards from the outer peripheral end 22b of the second inductor wiring 22A; a second connecting wiring 82 extending upwards from the via wiring 25 and penetrating the interior of the insulating layer 15; a via wiring 25 extending upwards from the second connecting wiring 82; and a second columnar wiring 32 extending upwards from the via wiring 25 and penetrating the interior of the second magnetic layer 12. The first and second vertical wirings 51 and 52 are made of the same material as the first inductor wiring 21A.

[0234] The first and second external terminals 41A and 42A are formed of a conductive material, such as Cu (low resistance and excellent stress resistance), Ni (excellent corrosion resistance), and Au (excellent solder wettability and reliability), arranged in three layers from the inside to the outside. The thickness of each Cu / Ni / Au layer is, for example, 5 / 5 / 0.01 μm.

[0235] A first external terminal 41A is disposed on the top of the second magnetic layer 12 (first main surface 10a), covering the end face of the first columnar wiring 31 exposed therefrom. Thus, the first external terminal 41A is electrically connected to the outer peripheral end 21b of the first inductor wiring 21A. A second external terminal 42A is disposed on the top of the second magnetic layer 12, covering the end face of the second columnar wiring 32 exposed therefrom. Thus, the second external terminal 42A is electrically connected to the outer peripheral end 22b of the second inductor wiring 22A.

[0236] Preferably, the first and second external terminals 41A and 42A are subjected to rust prevention treatment. Here, rust prevention treatment refers to coating with Ni and Au, or Ni and Sn, etc. This can suppress copper leaching and rusting caused by solder, and provide inductor component 1A with high installation reliability.

[0237] The coating 50, made of an insulating material, is disposed on top of the second magnetic layer 12 and exposes the end faces of the first and second columnar wirings 31 and 32 and the first and second external terminals 41 and 42. The coating 50 suppresses short circuits between the first external terminal 41 and the second external terminal 42. The coating is equivalent to the "insulating layer" as described in the claims. It should be noted that the coating 50 may also be formed on the underside of the first magnetic layer 11.

[0238] Figure 8 for Figure 7 An enlarged view of part A. (See image below.) Figure 8 As shown, the second side surface 10d of the unit body 10 has an oxidized region R1, a non-oxidized region R2, and a recess C. The configuration of the oxidized region R1, the non-oxidized region R2, and the recess C is the same as in the first embodiment. It should be noted that the second side surface 10d is used as an example here, but the oxidized region R1, the non-oxidized region R2, and the recess C can be provided on one or more of the first side surface 10c, the second side surface 10d, the third side surface 10e, and the fourth side surface 10f. In addition, the recess C is preferably provided on the side surface of the unit body, but it may not be provided.

[0239] According to this embodiment, by providing oxide regions R1 on the first to fourth sides 10c to 10f of the unit body 10, the resistance of the magnetic powder 100 can be increased, and short circuits can be suppressed. Furthermore, by providing non-oxidized regions R2 on the first to fourth sides 10c to 10f, the reduction in unit body strength and inductance can be suppressed. Additionally, since the first inductor wiring 21A and the second inductor wiring 22A are arranged along a direction orthogonal to the first main surface, the inductance density can be increased.

[0240] (Manufacturing method)

[0241] Next, the manufacturing method of inductor component 1A will be described. Figures 9A to 9M Corresponding to Figure 6 A-A section ( Figure 7 ).

[0242] like Figure 9A As shown, a substrate 70 is prepared. A first insulating layer 71 is coated on the main surface of the substrate 70 and cured. A second insulating layer 15 is coated on the first insulating layer 71, a predetermined pattern is formed using photolithography, and then cured.

[0243] like Figure 9BAs shown, a seed layer (not shown) is formed on the first insulating layer 71 and the second insulating layer 15 by a known method such as sputtering or vapor deposition. Then, a dry film resist (DFR) 75 is attached, and a predetermined pattern is formed on the DFR 75 using photolithography. The predetermined pattern consists of through-holes corresponding to the positions of the second inductor wiring 22A, the first connection wiring 81, and the first and second lead-out wirings 201 and 202 on the second insulating layer 15.

[0244] like Figure 9C As shown, the seed layer is powered, and the second inductor wiring 22A, the first connection wiring 81, and the first and second lead wirings 201 and 202 are formed on the second insulating layer 15 using electroplating. Afterwards, the DFR75 is stripped, and the seed layer is etched.

[0245] like Figure 9D As shown, a second insulating layer 15 is further coated to cover the exposed surfaces of the second inductor wiring 22A, the first connection wiring 81, the first and second lead wirings 201 and 202, and the first insulating layer 71. Then, using photolithography, vias 15a corresponding to the positions where the via wiring 25 is provided and through holes corresponding to the portions that become magnetic circuits are formed, and the second insulating layer 15 is cured.

[0246] like Figure 9E As shown, a seed layer (not shown) is formed on the first insulating layer 71 and the second insulating layer 15 using known methods such as sputtering or vapor deposition. Then, a DFR (Digital Framing Frame) is attached, and a predetermined pattern is formed on the DFR using photolithography. At this point, the DFR remains in the portion that becomes the magnetic circuit, protecting that portion. The predetermined pattern is a through-hole corresponding to the positions of the first inductor wiring 21A and the second connecting wiring 82 on the second insulating layer 15, and the via wiring 25 on the second inductor wiring 22A and the first connecting wiring 81. Then, power is supplied to the seed layer, and via wiring 25 is formed within the via 15a using electroplating, forming the first inductor wiring 21A and the second connecting wiring 82 on the second insulating layer 15. Finally, the DFR 75 is stripped, and the seed layer is etched.

[0247] like Figure 9F As shown, a second insulating layer 15 is further coated to cover the exposed surfaces of the first inductor wiring 21A and the first insulating layer 71. Then, using photolithography, vias 15a corresponding to the locations of the via wiring 25 and through holes corresponding to the portions forming the magnetic circuit are formed, and the second insulating layer 15 is cured. The cured second insulating layer 15 becomes... Figure 7 Insulating layer 15 is shown.

[0248] like Figure 9GAs shown, a seed layer (not shown) is formed on the first insulating layer 71 and the second insulating layer 15 using known methods such as sputtering or vapor deposition. Then, a DFR (Digital Framing Frame) is attached, and a predetermined pattern is formed on the DFR using photolithography. At this point, the DFR remains in the portion that becomes the magnetic circuit, protecting that portion. The predetermined pattern corresponds to through-holes at the positions of the via wirings 25 on the first inductor wiring 21A and the second connection wiring 82, as well as the first and second columnar wirings 31 and 32. Next, power is supplied to the seed layer, and via wirings 25 are formed within the vias 15a using electroplating. The first and second columnar wirings 31 and 32 are formed on the via wirings 25. Then, the DFR 75 is stripped, and the seed layer is etched.

[0249] like Figure 9H As shown, the magnetic sheet that will become the second magnetic layer 12 is pressed from above the first inductor wiring 21A towards the first inductor wiring 21A, and the second magnetic layer 12 is used to cover the second insulating layer 15 and the first and second columnar wirings 31 and 32. Then, the top surface of the second magnetic layer 12 is ground so that the end faces of the first columnar wiring 31 and the second columnar wiring 32 are exposed from the top surface of the second magnetic layer 12.

[0250] like Figure 9I As shown, a third insulating layer 50 is coated on top of the second magnetic layer 12. Then, using photolithography, a predetermined pattern is formed on the third insulating layer 50 and cured. The predetermined pattern is a pattern in which the third insulating layer covers the area on top of the second magnetic layer 12, excluding the areas forming the first and second external terminals 41A and 42A. The cured third insulating layer 50 becomes... Figure 7 The coating 50 is shown.

[0251] like Figure 9J 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 can be removed by peeling.

[0252] like Figure 9K As shown, other magnetic sheets that will become the first magnetic layer 11 are pressed together from below the second inductor wiring 22A toward the second inductor wiring 22A, using the first magnetic layer 11 to cover the underside of the second insulating layer 15 and the second magnetic layer 12. Then, the first magnetic layer 11 is ground to a predetermined thickness.

[0253] like Figure 9LAs shown, the first and second external terminals 41A and 42A are formed by electroless plating, covering the end faces of the first and second columnar wirings 31 and 32 exposed from the first main surface 10a. The first and second external terminals 41A and 42A are, for example, Cu / Ni / Au layers stacked sequentially from the first main surface 10a side. It should be noted that before forming the first and second external terminals 41A and 42A, a catalyst such as Pd (not shown) can be applied to the portions where the first and second external terminals 41A and 42A contact the top surface of the unit body 10 and the end faces of the first and second columnar wirings 31 and 32.

[0254] like Figure 9M As shown, the inductor component 1A is monolithically formed using the cutting line D. During or after monolithization, the process is the same as in the first embodiment, forming oxidized and non-oxidized regions on the side of the unit body; preferably, a recess is formed during monolithization. This is performed as described above. Figure 7 As shown, inductor component 1A is manufactured. It should be noted that the top of unit body 10 is covered by the third insulating layer 50, so no oxide region is formed.

[0255] <Third Implementation>

[0256] Figure 10 This is a diagram illustrating a third embodiment of an inductor component. The unit structure of the third embodiment differs from that of the first embodiment. This difference is explained below. Other structures are the same as in the first embodiment; therefore, the same reference numerals are used, and their descriptions are omitted. It should be noted that... Figure 10 Corresponding to Figure 1 The C-C section.

[0257] like Figure 10 As shown, the third side surface 10e of unit body 10A has a first region A1 extending in a predetermined range orthogonal to the first main surface 10a (Z direction) from the first main surface 10a, and a second region A2 excluding the first region A1e. The D50 particle size of the magnetic powder 100 in the second region A2 is larger than that of the magnetic powder 100 in the first region A1. Furthermore, compared to the first region A1, the area of ​​the non-oxidized region R2 is larger, and compared to the first region A1, the area of ​​the oxidized region R1 in the second region A2 is larger. This is because the large-particle-size magnetic powder 100 is easily oxidized, and the oxidized region R1 can be easily formed. As a result, the area of ​​the oxidized region R1 in the first region A1, which contains the large-particle-size magnetic powder 100, can be increased.

[0258] The aforementioned "specified range" is defined as the range where the length L of the first region A1, in the direction orthogonal to the first main surface 10a (Z direction), is shorter than the wiring length of the first columnar wiring 31. The length L is preferably less than half the wiring length of the first columnar wiring 31, and more preferably less than one-third of the wiring length of the first columnar wiring 31. Furthermore, from the viewpoint of ensuring the strength of the corners of the unit body 10, the length L is preferably more than one-tenth of the thickness of the unit body 10. The length L is, for example, 30 μm. Additionally, the aforementioned "D50 particle size of the magnetic powder 100 in the first region A1" and "D50 particle size of the magnetic powder 100 in the second region A2" can be measured, for example, by observing the third side surface 10e using SEM. The specific method for calculating the particle size by performing SEM observation is the same as the method for calculating the particle size of the magnetic powder 100 described in the first embodiment. It should be noted that the other sides 10c, 10d, and 10f are also constructed in the same way as the third side 10e.

[0259] According to this embodiment, the D50 particle size of the magnetic powder 100 in the second region A2 is larger than the D50 particle size of the magnetic powder 100 in the first region A1. Figure 10 It can be seen that the state of the second region A2 of the third side surface 10e can be maintained within the unit body 10 in the XY plane direction relative to the second region A2. Therefore, the magnetic powder 100 with a larger particle size can be disposed around the first and second inductor wirings 21 and 22. As a result, inductance can be ensured. In addition, the magnetic powder 100 with a smaller particle size is disposed in the first region A1. In the magnetic powder 100 with a smaller particle size, the contact area between particles is smaller. Therefore, short circuits of the magnetic powder 100 in the first region A1 can be suppressed. In addition, in the third side surface 10e, the area of ​​the oxide region R1 in the second region A2 is larger than that in the first region A1, so short circuits of the magnetic powder 100 in the second region A2 can be suppressed. It should be noted that in the unit body 10A, by increasing the range of the second region A2, the inductance can be further improved, and by increasing the range of the first region A1, short circuits around the first main surface of the magnetic powder 100 can be further suppressed.

[0260] For example, magnetic powders used as the non-oxidized region R2 can be categorized as those with a D50 particle size of less than 2 μm, composed of FeSiCr alloys, etc., and which readily form passivation films other than Fe-based on their surface. Figure 10 In the image, magnetic powder with a D50 particle size of 1.4 μm and a D90 particle size of 3.1 μm was used. On the other hand, examples of magnetic powders used for the oxide region R1 include those with a D50 particle size of 5 μm or larger and a high Fe content, such as FeSi alloys. Figure 10The image shows magnetic powder with a D50 particle size of 6.8 μm and a D90 particle size of 14.0 μm.

[0261] Preferably, the amount of Fe in the oxidized region R1 is greater than the amount of Fe in the non-oxidized region R2. Specifically, the oxide film in the oxidized region R1 is iron oxide. Based on the above configuration, the oxidized region R1 has a higher amount of Fe, therefore, a large amount of Fe can be arranged around the first and second inductor wirings 21 and 22, ensuring inductance.

[0262] Preferably, the unit cell 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 10 For convenience, the boundaries of the first magnetic layer 11, the second magnetic layer 12, and the third magnetic layer 13 are shown with dashed lines. The second magnetic layer 12 mainly contains large-particle magnetic powder 100, and the third magnetic layer 13 mainly contains small-particle magnetic powder 100. The second magnetic layer 12, which is connected to 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 can ensure inductance.

[0263] The manufacturing method of the inductor component at this time will be described. First Embodiment Figures 4A to 4F Same. Then, as... Figure 11 As shown, a magnetic sheet comprising large-particle-size magnetic powder 100, which serves as the second magnetic layer 12, is pressed onto the top of the first inductor wiring 21 and the second inductor wiring 22, thereby covering the first inductor wiring 21 and the second inductor wiring 22 using the second magnetic layer 12. Then, a magnetic sheet comprising small-particle-size magnetic powder 100, which serves as the third magnetic layer 13, is pressed onto the top of the magnetic sheet of the second magnetic layer 12, thereby covering the second magnetic layer 12 using the third magnetic layer 13. At this time, in the portions containing the first inductor wiring 21 and the second inductor wiring 22, the second magnetic layer 12 and the third magnetic layer 13 protrude upwards. Afterwards, a portion of the second magnetic layer 12 and the third magnetic layer 13 is ground. Then, the first embodiment... Figures 4H to 4I same.

[0264] It should be noted that the present invention is not limited to the embodiments described above, and the design can be modified without departing from the spirit of the invention. For example, the feature points of the first and third embodiments can be combined in various ways.

[0265] In the above embodiment, a first inductor wiring and a second inductor wiring are configured in the unit body, but one or more inductor wirings can also be configured. In this case, there can be four or more external terminals and post wirings.

[0266] In the above embodiments, "inductor wiring" refers to wiring that generates magnetic flux in a magnetic layer when current flows through it, thereby imparting inductance to the inductor component. Its structure, shape, and material are not particularly limited. In particular, it is not limited to straight lines or curves (spirals = two-dimensional curves) extending on a plane as in the embodiments described above; various known wiring shapes, such as meandering wiring, can be used. Furthermore, the total number of inductor wiring layers is not limited to one or two layers; it can also be a multi-layer structure with three or more layers. Additionally, the shape of the columnar wiring is rectangular when viewed from the Z-direction, but it can also be circular, elliptical, or oblong.

[0267] Furthermore, the control of oxidized and non-oxidized regions is not limited to the methods described in the above embodiments, and other formation methods can also be used. For example, the fluidity of the resin in the magnetic layer can be reduced. As a result, the magnetic powder flows simultaneously with the resin, thus reducing the likelihood of magnetic powder adhesion. Consequently, the pressure at the top of the inductor wiring increases, causing the magnetic powder to flow in areas other than the top of the inductor wiring. As a result, the filling rate of magnetic powder on the side of the cell increases, and oxidized regions can be formed on the side of the cell.

Claims

1. An inductor component comprising: The unit cell contains magnetic powder and has a first main surface, a second main surface, and a side surface connecting the first main surface and the second main surface. The inductor wiring is disposed within the unit body. A first vertical wiring is disposed within the unit 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 unit body, connected to the second end of the inductor wiring, and extends to the first main surface. The first external terminal, which is connected to the first vertical wiring and exposed on the first main surface, and The second external terminal is connected to the second vertical wiring and is exposed on the first main surface; in, The magnetic powder is mainly composed of Fe. The side has an oxidized region and a non-oxidized region. The oxidized region is the area where the oxide film of the plurality of magnetic powders is exposed. The non-oxidized region is the area where the plurality of magnetic powders are exposed. Furthermore, the oxidized region is the area where Fe content is 65 wt% or more and O content is 24 wt% or more, and the non-oxidized region is the area where Fe content is 65 wt% or more and O content is less than 24 wt%.

2. The inductor component according to claim 1, wherein, The unit cell 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 unit cell contains a resin containing the magnetic powder. The magnetic powder in the oxidation 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 reflectance of the oxidized region at wavelengths of 600nm to 800nm ​​is in a greater proportion than that 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 cross-section of the magnetic powder.

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

7. The inductor component according to any one of claims 1 to 3, wherein, The inductor wiring has a first lead that is connected to the first end and exposed from the side.

8. The inductor component according to any one of claims 1 to 3, wherein, The inductor is wired in multiple ways. Multiple inductor wirings are arranged on the same plane parallel to the first main surface and electrically isolated from each other.

9. The inductor component according to claim 7, wherein, The inductor is wired in multiple ways. Multiple inductor wirings are arranged along a direction orthogonal to the first main surface.

10. The inductor component according to any one of claims 1 to 3, wherein, It further includes an insulating layer disposed on the first main surface.

11. The inductor component according to any one of claims 1 to 3, wherein, The first main surface has the oxidized region and the non-oxidized region.

12. The inductor component according to any one of claims 1 to 3, wherein, The side surface has a first region extending from the first main surface in a direction orthogonal to the first main surface, and a second region outside the first region. The D50 particle size of the magnetic powder in the second region is larger than that of the magnetic powder in the first region. In the side view, the non-oxidized region of the first region is larger than the second region, and the oxidized region of the second region is larger than the first region.

13. The inductor component according to any one of claims 1 to 3, wherein, The unit cell has multiple magnetic layers stacked in a direction orthogonal to the first principal surface. The magnetic layer, which is connected to the inductor wiring, is configured along a portion of the outline of the inductor wiring.

14. The inductor component according to any one of claims 1 to 3, wherein, The magnetic powder in the oxidized region has a larger D50 particle size than the magnetic powder in the non-oxidized region.

15. The inductor component according to claim 14, wherein, The amount of Fe in the oxidized region is greater than the amount of Fe in the non-oxidized region.

16. The inductor component according to any one of claims 1 to 3, wherein, The side also has a recess.

17. An inductor component comprising: The unit cell contains magnetic powder and has a first main surface, a second main surface, and a side surface connecting the first main surface and the second main surface. The inductor wiring is disposed within the unit body. A first vertical wiring is disposed within the unit 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 unit body, connected to the second end of the inductor wiring, and extends to the first main surface. The first external terminal, which is connected to the first vertical wiring and exposed on the first main surface, and The second external terminal is connected to the second vertical wiring and is exposed on the first main surface; in, The magnetic powder is mainly composed of Fe. The side has an oxidized region and a non-oxidized region. The oxidized region is an area on the plurality of magnetic powders where Fe content is 65 wt% or more and O content is 24 wt% or more. The non-oxidized region is the non-oxidized area exposed by the plurality of magnetic powders.

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