Inductor component and method of manufacturing the same

Abstract

The present application provides an inductor component, comprising a green body having a first magnetic layer and a second magnetic layer sequentially stacked along a first direction, and an inductor wiring arranged on a plane orthogonal to the first direction between the first magnetic layer and the second magnetic layer, the first magnetic layer comprising magnetic powder and a resin containing the magnetic powder, the second magnetic layer comprising flat-shaped magnetic powder and a resin containing the magnetic powder, the first magnetic layer being present in the opposite direction of the first direction of the inductor wiring, the second magnetic layer being present in the first direction of the inductor wiring and the direction orthogonal to the first direction, when observing the main surface of the second magnetic layer from the direction orthogonal to the main surface of the second magnetic layer in the first direction, the second magnetic layer has a dark area along the inductor wiring and a bright area brighter than the dark area, and the bright area is a region other than the dark area.

Description

TECHNICAL FIELD

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

[0002] In the past, as an inductor component, there are an inductor component described in Japanese Patent Application Publication No. 2016-122836 (Patent Literature 1) and Japanese Patent Application Publication No. 2019-140202 (Patent Literature 2).

[0003] The inductor component described in Japanese Patent Application Publication No. 2016-122836 has an inductor wiring, a first magnetic body main body in which the inductor wiring is buried, and a second magnetic body main body provided at the upper and lower portions of the first magnetic body main body. The first magnetic body main body contains a substantially spherical magnetic powder. The second magnetic body main body contains a metal magnetic plate.

[0004] The inductor component described in Japanese Patent Application Publication No. 2019-140202 has an inductor wiring, a first magnetic body main body in which the inductor wiring is buried, and a second magnetic body main body provided at the upper and lower portions of the first magnetic body main body. The first magnetic body main body contains a substantially spherical magnetic powder. The second magnetic body main body contains a flat-shaped magnetic powder.

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2016-122836

[0006] Patent Literature 2: Japanese Patent Application Publication No. 2019-140202

[0007] However, in the above-described conventional inductor component, a substantially spherical magnetic powder is used in the first magnetic body main body in which the inductor wiring is buried. Therefore, the permeability of the first magnetic body main body is lower than that of the second magnetic body main body containing a metal magnetic plate and a flat-shaped magnetic powder, and the inductance acquisition efficiency is not sufficient.

[0008] In addition, as a reason for using a substantially spherical magnetic powder in the first magnetic body main body that covers the inductor wiring, it is difficult to sufficiently fill the magnetic powder around the inductor wiring because the ball bearing effect and the like are not obtained in a non-spherical magnetic powder such as a flat shape.

[0009] Furthermore, it is known that in the case where the magnetic powder is not sufficiently filled, the desired inductance cannot be obtained after the manufacturing of the inductor component, the electrical characteristic screening process, and the mounting of the inductor component, and at this time, the insufficient filling of the magnetic powder is first detected. In this way, if the poor filling of the magnetic powder is detected after the manufacturing of the inductor component, the manufacturing loss of the product becomes large. SUMMARY

[0010] Accordingly, the present disclosure provides an inductor component capable of improving the acquisition efficiency of inductance, and also capable of non-destructively detecting early filling failure of magnetic powder to reduce manufacturing loss of products.

[0011] To solve the above problem, an inductor component according to an embodiment of the present disclosure includes:

[0012] a green body having a first magnetic layer and a second magnetic layer sequentially stacked along a first direction; and

[0013] an inductor wiring disposed on a plane orthogonal to the first direction between the first magnetic layer and the second magnetic layer,

[0014] the first magnetic layer includes magnetic powder and a resin containing the magnetic powder,

[0015] the second magnetic layer includes flat-shaped magnetic powder and a resin containing the magnetic powder,

[0016] the first magnetic layer exists in a direction opposite to the first direction of the inductor wiring,

[0017] the second magnetic layer exists in the first direction of the inductor wiring and a direction orthogonal to the first direction,

[0018] when the main surface of the second magnetic layer is observed from a direction orthogonal to the main surface of the second magnetic layer in the first direction, the second magnetic layer has a dark portion region along the inductor wiring, and a bright portion region brighter than the dark portion region, the bright portion region being a region other than the dark portion region.

[0019] Here, the dark portion region along the inductor wiring means that the dark portion region extends along the extension direction of the inductor wiring, and the dark portion region is adjacent to the inductor wiring or at least partially overlaps the inductor wiring when the second magnetic layer is observed from a direction orthogonal to the main surface of the second magnetic layer.

[0020] According to the above embodiment, since the second magnetic layer includes flat-shaped magnetic powder, the demagnetizing field is reduced, and a higher relative permeability is obtained. In addition, the inductor wiring is disposed between the first magnetic layer and the second magnetic layer, and the second magnetic layer exists in the first direction of the inductor wiring and a direction orthogonal to the first direction, so that the flat-shaped magnetic powder can be disposed around the inductor wiring. Thus, the filling rate of the flat-shaped magnetic powder is improved, the permeability around the inductor wiring is improved, and the acquisition efficiency of inductance is improved.

[0021] In addition, the second magnetic layer has a dark region along the inductor wiring and a bright region other than the dark region when viewed from a direction orthogonal to the main surface of the second magnetic layer, and thus the directly above the bright region appears brighter and the directly above the dark region appears darker in the main surface of the second magnetic layer. Thus, when the second magnetic layer is press-bonded to the inductor wiring to be manufactured, it is possible to confirm that the magnetic powder included in the second magnetic layer is arranged as desired. If described specifically, it is possible to determine that the long axis of the magnetic powder included in the bright region is arranged substantially in parallel to the main surface of the second magnetic layer, and the long axis of the magnetic powder included in the dark region is arranged in a direction substantially orthogonal to the main surface of the second magnetic layer. Thus, the flat-shaped magnetic powder has poor flowability compared to the substantially spherical magnetic powder, and thus there is a problem in filling property, but by confirming the brightness and darkness of the main surface of the second magnetic layer, it is possible to easily determine whether the magnetic powder of the second magnetic layer is filled in the desired arrangement, and thus it is possible to non-destructively detect filling failure of the magnetic powder early, and it is possible to reduce manufacturing loss of products.

[0022] Preferably, in one embodiment of the inductor component, the thickness of the second magnetic layer in the first direction between the main surface of the second magnetic layer and the top surface of the inductor wiring in the first direction is 3 times or less the height of the inductor wiring in the first direction.

[0023] According to the above embodiment, the thickness between the main surface of the second magnetic layer and the top surface of the inductor wiring is 3 times or less the height of the inductor wiring, and thus it is possible to easily confirm the dark region and the bright region.

[0024] Preferably, in one embodiment of the inductor component,

[0025] The above green body further has a coating film that covers the main surface of the second magnetic layer,

[0026] The dark region and the bright region cannot be distinguished through the coating film.

[0027] According to the above embodiment, since the dark region and the bright region cannot be distinguished through the coating film, it is possible to suppress excessive classification (excessive screening) at the appearance screening step after the inductor component is manufactured.

[0028] Preferably, in one embodiment of the inductor component,

[0029] The above green body further has an external terminal that is electrically connected to the inductor wiring,

[0030] The coating film is arranged at a portion of the main surface of the second magnetic layer so that the external terminal is exposed,

[0031] The main surface of the first magnetic layer in the direction opposite to the first direction becomes the outermost surface of the green sheet.

[0032] According to the above-described embodiment, by making the layer that imparts the function to a minimum, it is possible to reduce the manufacturing cost.

[0033] Preferably, in one embodiment of the inductor component, the first magnetic layer is flat-plate shaped.

[0034] According to the above-described embodiment, since the first magnetic layer is flat-plate shaped, in the first magnetic layer, the filling property of the magnetic powder does not need to be considered in relation to the inductor wiring, and the material of the magnetic powder can be freely selected. That is, the degree of freedom in the selection of the material of the magnetic powder is improved.

[0035] Preferably, in one embodiment of the inductor component, when the main surface of the first magnetic layer is observed in a direction orthogonal to the main surface in the direction opposite to the first direction of the first magnetic layer, the first magnetic layer has a first region along the inductor wiring, and a second region that cannot be distinguished from the first region in terms of brightness, the second region being a region other than the first region.

[0036] Here, the first region along the inductor wiring means that the first region extends along the extension direction of the inductor wiring, and that the first region is adjacent to the inductor wiring, or that the first region overlaps at least a part of the inductor wiring, when viewed in a direction orthogonal to the main surface of the first magnetic layer. By cannot be distinguished in terms of brightness, it is meant that the difference in brightness is 0, and that a slight difference is allowed.

[0037] According to the above-described embodiment, in the main surface of the first magnetic layer, the directly above of the first region and the directly above of the second region appear to be the same brightness. Therefore, it is possible to easily distinguish the upper and lower of the inductor component in terms of appearance.

[0038] Preferably, in one embodiment of the inductor component, a columnar wiring is further provided, the columnar wiring is connected to the inductor wiring, and extends in the first direction to penetrate the second magnetic layer.

[0039] According to the above-described embodiment, it is possible to lead the columnar wiring from the inductor wiring in a straight line, and it is possible to suppress an increase in direct current resistance and a decrease in inductance acquisition efficiency due to additional winding.

[0040] Preferably, in one embodiment of the inductor component, at least one of the inductor wiring and the columnar wiring is in contact with the magnetic powder.

[0041] According to the above-described embodiment, by eliminating unnecessary insulating portions, the efficiency of obtaining inductance can be improved. In addition, if a plurality of magnetic powders are electrically connected in a direction orthogonal to the first direction, short-circuiting can occur between different inductance lines or between turns of the same inductance line via the magnetic powders, but the long axes of the magnetic powders included in the dark regions along the inductance line are arranged in a direction substantially orthogonal to the main surface of the second magnetic layer, so even if at least one of the inductance line and the columnar line comes into contact with the magnetic powders, the possibility of short-circuiting is low.

[0042] Preferably, in one embodiment of the inductor component,

[0043] The above-described inductance line includes a side surface facing a direction orthogonal to the above-described first direction,

[0044] The above-described inductor component further includes a side surface insulating portion covering only a part of the above-described side surface.

[0045] Here, the side surface insulating portion covering only a part of the side surface of the inductance line includes not only a state in which the side surface insulating portion is in contact with only a part of the side surface of the inductance line, but also a state in which there is another component between the side surface insulating portion and a part of the side surface of the inductance line, and the side surface insulating portion covers only a part of the side surface of the inductance line together with the other component.

[0046] According to the above-described embodiment, since the side surface insulating portion is in contact with only a part of the side surface of the inductance line, for example, even in a case where a plurality of magnetic powders are electrically connected in a direction orthogonal to the first direction, the part of the side surface of the inductance line is not in contact with the magnetic powders by the side surface insulating portion. Thus, the insulating property can be ensured.

[0047] Preferably, in one embodiment of the inductor component,

[0048] The above-described inductance line includes a bottom surface facing an opposite direction of the above-described first direction,

[0049] The above-described inductor component further includes a bottom surface insulating portion in contact with the above-described bottom surface.

[0050] According to the above-described embodiment, by the bottom surface insulating portion, the bottom surface of the inductance line is not in contact with the magnetic powders of the first magnetic layer. Thus, the insulating property can be improved.

[0051] Preferably, in one embodiment of the inductor component, a height of the above-described side surface insulating portion in the above-described first direction is half or less of a height of the above-described inductance line in the above-described first direction.

[0052] Here, the height refers to a value measured in a cross section orthogonal to a direction in which the inductance line extends.

[0053] According to the above embodiment, by reducing the height of the side surface insulating portion, the volume of the magnetic layer is increased, the insulation is ensured, and the inductance acquisition efficiency is further improved.

[0054] Preferably, in one embodiment of the inductor component,

[0055] The inductor wire includes a top surface in the first direction,

[0056] The inductor component further includes a peripheral surface insulating portion in contact with the side surface and the top surface,

[0057] The peripheral surface insulating portion has a different composition from that of the side surface insulating portion and that of the bottom surface insulating portion,

[0058] The thickness of the side surface insulating portion is thicker than that of the peripheral surface insulating portion.

[0059] Here, the thickness refers to the maximum value measured in a cross section orthogonal to the direction in which the inductor wire extends.

[0060] According to the above embodiment, the insulation can be further improved.

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

[0062] The inductor wire includes a side surface in a direction orthogonal to the first direction,

[0063] In a cross section orthogonal to the direction in which the inductor wire extends,

[0064] The second magnetic layer has a side surface near region between the side surface of the inductor wire and a position separated from the side surface by a predetermined distance in a direction orthogonal to the first direction,

[0065] The long axis of the flat-shaped magnetic powder included in the side surface near region forms an angle of 45° or less with respect to the side surface.

[0066] Here, the side surface near region is a region surrounded by the side surface, the position separated from the side surface by a predetermined distance, an extension surface including the top surface, and an extension surface including the bottom surface. The distance from the side surface of the inductor wire is set as the distance from the end portion of the bottom surface side of the side surface of the inductor wire. The predetermined distance is 1 / 3 of the width of the inductor wire in the direction orthogonal to the first direction.

[0067] Further, the long axis of the magnetic powder refers to a straight line passing through the longest portion of the magnetic powder in the aforementioned cross section. By obtaining an SEM image in a cross section orthogonal to the direction in which the inductor wire extends, and binarizing the SEM image with white color as the magnetic powder and black color as the resin, the angle of the long axis of the magnetic powder with respect to the side surface of the inductor wire is measured to derive the angle of the long axis of the magnetic powder with respect to the side surface.

[0068] According to the above-described embodiment, the angle of the long axis of the magnetic powder with respect to the side surface is 45° or less, and thus in the vicinity of the side surface, the long axis of the magnetic powder is arranged substantially in parallel to the side surface of the inductor wire. Therefore, in the vicinity of the side surface, the magnetic powder and the resin are alternately arranged in the direction orthogonal to the first direction, and the inductance acquisition efficiency can be maintained and the insulation can be ensured.

[0069] Preferably, in one embodiment of the inductor component,

[0070] The above-described inductor wire includes a side surface facing a direction orthogonal to the above-described first direction,

[0071] In a cross section orthogonal to the direction in which the above-described inductor wire extends,

[0072] The angle of the long axis of the above-described flat-shaped magnetic powder included in the above-described second magnetic layer with respect to the above-described side surface increases as it moves away from the above-described side surface of the above-described inductor wire in a direction orthogonal to the above-described first direction.

[0073] Here, the angle of the long axis of the magnetic powder with respect to the side surface increasing refers to the angle changing from 0° toward 90°.

[0074] According to the above-described embodiment, in the vicinity of the side surface of the inductor wire, the long axis of the magnetic powder is arranged substantially in parallel to the side surface, and thus the magnetic powder and the resin are alternately arranged in the direction orthogonal to the first direction, and the inductance acquisition efficiency can be maintained and the insulation can be ensured.

[0075] Preferably, in one embodiment of the inductor component,

[0076] The above-described first magnetic layer includes flat-shaped magnetic powder,

[0077] The above-described inductor wire includes a bottom surface facing a direction opposite to the above-described first direction,

[0078] In a cross section orthogonal to the direction in which the above-described inductor wire extends,

[0079] The angle of the long axis of the above-described flat-shaped magnetic powder included in the above-described first magnetic layer with respect to the above-described bottom surface is 45° or less.

[0080] According to the above embodiment, the angle of the long axis of the magnetic powder with respect to the bottom surface is 45° or less, and thus the long axis of the magnetic powder is arranged substantially parallel to the bottom surface of the inductor wire. Therefore, the arrangement of the magnetic powder is parallel to the magnetic flux, and a higher relative permeability can be obtained.

[0081] Preferably, in one embodiment of the inductor component,

[0082] In a cross section at the center of the direction in which the inductor wire extends and orthogonal to the direction in which the inductor wire extends,

[0083] When the maximum Feret length of the magnetic powder is set to LF and the thickness of the magnetic powder orthogonal to the maximum Feret length is set to TF, LF / TF≥10, and the D90 of the maximum Feret length is 100 μm or less.

[0084] Here, the D90 of the maximum Feret length is obtained by acquiring SEM images in the above cross section at about three points in a 200 μm x 200 μm region and calculating the D90 thereof.

[0085] According to the above embodiment, since LF / TF≥10, the flatness of the magnetic powder can be increased, and thus a higher relative permeability can be obtained.

[0086] Further, since the D90 of the maximum Feret length is 100 μm or less, the insulating property can be ensured. For example, in the case where the maximum Feret length is excessively large, the possibility of short-circuiting between different inductor wires or between turns of the same inductor wire via the magnetic powder increases.

[0087] Preferably, in one embodiment of the inductor component, the void ratio in each of the first magnetic layer and the second magnetic layer is 1 vol% or more and 10 vol% or less.

[0088] According to the above embodiment, since the void ratio is 1 vol% or more, the residual stress and stress from external stress can be alleviated by the voids. Since the void ratio is 10 vol% or less, the decrease in inductance and the decrease in strength of the green body can be suppressed.

[0089] Preferably, in one embodiment of the inductor component,

[0090] A plurality of the inductor wires are arranged along the first direction,

[0091] The dark region is a region of the inductor wire located at the outermost side in the first direction.

[0092] According to the above-described embodiment, by layering the inductor wiring, it is possible to reduce the influence on the mounting area. Also, if the layered inductor wiring is connected in series, it is possible to increase the inductance.

[0093] Preferably, in one embodiment of the method of manufacturing the inductor component, there is provided:

[0094] a step of forming an inductor wiring on a main surface of a base substrate;

[0095] a step of pressing a magnetic sheet from above the main surface of the base substrate toward the inductor wiring, the magnetic sheet covering a top surface and a side surface of the inductor wiring, the magnetic sheet including a flat-shaped magnetic powder and a resin containing the magnetic powder; and

[0096] a step of observing the magnetic sheet from above the magnetic sheet, identifying, and checking whether the magnetic powder is filled in the side surface of the inductor wiring by light and shade.

[0097] According to the above-described embodiment, by observing the magnetic sheet from above the magnetic sheet to confirm light and shade, it is possible to easily determine whether the magnetic powder is filled in the side surface of the inductor wiring, thereby non-destructively and early detecting a filling failure of the magnetic powder at the manufacturing stage of the inductor component, and reducing manufacturing loss of products.

[0098] According to the inductor component and the method of manufacturing the inductor component as one embodiment of the present disclosure, it is possible to improve the efficiency of obtaining inductance, and non-destructively early detect a filling failure of the magnetic powder to reduce manufacturing loss of products. BRIEF DESCRIPTION OF DRAWINGS

[0099] Figure 1 is a plan view showing a first embodiment of an inductor component.

[0100] Figure 2A is an A-A cross-sectional view of Figure 1

[0101] Figure 2B is a B-B cross-sectional view of Figure 1

[0102] Figure 2C is a C-C cross-sectional view of Figure 1

[0103] Figure 3 is a simple cross-sectional view orthogonal to the direction in which the first inductor wiring extends.

[0104] Figure 4 is an image diagram corresponding to Figure 3

[0105] Figure 5 is​​​​Figure 3 An enlarged view of a portion of

[0106] Figure 6 An enlarged view of an image in a cross section orthogonal to the direction of extension of the first inductive wiring.

[0107] Figure 7A A plan view of the inductor component.

[0108] Figure 7B A simplified cross-sectional view orthogonal to the direction of extension of the first inductive wiring of the inductor component.

[0109] Figure 7C A bottom view of the inductor component.

[0110] Figure 8 An image of the inductor component taken from a planar direction and adjusted for brightness.

[0111] Figure 9A An explanatory view explaining the manufacturing method of the inductor component.

[0112] Figure 9B An explanatory view explaining the manufacturing method of the inductor component.

[0113] Figure 9C An explanatory view explaining the manufacturing method of the inductor component.

[0114] Figure 9D An explanatory view explaining the manufacturing method of the inductor component.

[0115] Figure 9E An explanatory view explaining the manufacturing method of the inductor component.

[0116] Figure 9F An explanatory view explaining the manufacturing method of the inductor component.

[0117] Figure 9G An explanatory view explaining the manufacturing method of the inductor component.

[0118] Figure 9H An explanatory view explaining the manufacturing method of the inductor component.

[0119] Figure 9I An explanatory view explaining the manufacturing method of the inductor component.

[0120] Figure 9J An explanatory view explaining the manufacturing method of the inductor component.

[0121] Figure 9K An explanatory view explaining the manufacturing method of the inductor component.

[0122] Figure 9L is a diagram for explaining a manufacturing method of an inductor component.

[0123] Figure 10 is a plan view showing a second embodiment of an inductor component.

[0124] Figure 11A is a cross-sectional view of A-A of Figure 10

[0125] Figure 11B is a cross-sectional view of B-B of Figure 10

[0126] Figure 12 is a plan view of an inductor component.

[0127] Figure 13A is a cross-sectional view showing a third embodiment of an inductor component.

[0128] Figure 13B is a plan view of an inductor component.

[0129] Explanation of Reference Numerals

[0130] 1, 1A, 1B... inductor component; 10... blank; 10a... first main surface; 11... first magnetic layer; 11a... main surface; 12... second magnetic layer; 12a... main surface; 21, 21B... first inductor wiring; 21A... inductor wiring; 210... side surface; 211... bottom surface; 212... top surface; 22... second inductor wiring; 220... side surface; 221... bottom surface; 222... top surface; 31... first columnar wiring; 32... second columnar wiring; 33... third columnar wiring; 41... first external terminal; 42... second external terminal; 43... third external terminal; 50... covering film; 61... side surface insulating portion; 62... bottom surface insulating portion; 63... peripheral surface insulating portion; 70... base substrate; 80... magnetic sheet; 100... magnetic powder; 101... resin; L... long axis; Z0... side surface vicinity region; Z1... first region; Z2... second region; Za... dark portion region; Zb... bright portion region. DETAILED DESCRIPTION

[0131] Hereinafter, an inductor component and a manufacturing method thereof as one embodiment of the present disclosure will be described in detail through an illustrated embodiment. Furthermore, the drawings contain partially schematic structures, and there are cases where actual dimensions, ratios are not reflected.

[0132] (First Embodiment)

[0133] (Structure)

[0134] Figure 1 is a plan view showing a first embodiment of an inductor component. Figure 2A is​​Figure 1 AA sectional view. Figure 2B yes Figure 1 BB cross-sectional view. Figure 2C yes Figure 1 CC section view.

[0135] The inductor component 1 is used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, and automotive electronics, and is, for example, a component with a rectangular parallelepiped shape. However, the shape of the inductor component 1 is not particularly limited, and it can also be cylindrical, polygonal cylindrical, frustum conical, or polygonal frustum conical.

[0136] like Figure 1 , Figure 2A , Figure 2B as well as Figure 2C As shown, the inductor component 1 includes: a blank body 10, a first inductor wiring 21 and a second inductor wiring 22 disposed within the blank body 10, a side insulating portion 61 and a bottom insulating portion 62 covering a portion of the first inductor wiring 21 and the second inductor wiring 22, a first columnar wiring 31, a second columnar wiring 32 and a third columnar wiring 33 embedded in the blank body 10 so that their end faces are exposed from the first main surface 10a of the blank body 10, a first external terminal 41, a second external terminal 42 and a third external terminal 43 disposed on the first main surface 10a of the blank body 10, and a coating film 50 disposed on the first main surface 10a of the blank body 10.

[0137] In the figure, the thickness direction of inductor component 1 is defined as the Z-direction, the positive Z-direction as the top, and the negative Z-direction as the bottom. 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. Figure 1 In the text, the 50-degree membrane covering is omitted from the description.

[0138] The blank 10 has a first magnetic layer 11 and a second magnetic layer 12 sequentially stacked along the positive Z direction (corresponding to the "first direction" as described in the claims). The first magnetic layer 11 and the second magnetic layer 12 respectively comprise flat magnetic powder and a resin containing the magnetic powder. The resin is, for example, an organic insulating material composed of epoxy resin, bismaleimide, liquid crystal polymer, polyimide, etc. 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.

[0139] Preferably, the magnetic powder contains 80% by weight or more of Fe and contains 2% by weight or more of Si and Al. The composition of the magnetic powder is calculated by EDX. For example, the magnification is 5000 times, and the average of 5 points is calculated. According to the above structure, by adding Si and Al, magnetostriction can be reduced, and the relative permeability can be improved.

[0140] Preferably, in each of the first magnetic layer 11 and the second magnetic layer 12, the filling rate of the magnetic powder is 50% by volume or more and 75% by volume or less. According to the above structure, since the filling rate of the magnetic powder is 50% by volume or more, the amount of the magnetic powder can be increased to improve the relative permeability. In addition, since the filling rate of the magnetic powder is 75% by volume or less, the electrical connection of the plurality of magnetic powders can be reduced, and the insulation can be ensured.

[0141] Preferably, in each of the first magnetic layer 11 and the second magnetic layer 12, the porosity is 1% by volume or more and 10% by volume or less. According to the above structure, since the porosity is 1% by volume or more, the stress from the external stress and the residual stress can be moderated by the voids. Since the porosity is 10% by volume or less, the reduction of the inductance and the reduction of the strength of the green body can be suppressed.

[0142] The first inductor wiring 21 and the second inductor wiring 22 are arranged on a plane orthogonal to the Z direction between the first magnetic layer 11 and the second magnetic layer 12. That is, the first inductor wiring 21 and the second inductor wiring 22 are arranged on the same plane. Thereby, the low height of the inductor component 1 can be achieved. In addition, the inductor array can be constituted by the first inductor wiring 21 and the second inductor wiring 22 arranged in the same plane.

[0143] If described specifically, the first magnetic layer 11 exists in the negative Z direction of the first inductor wiring 21 and the second inductor wiring 22. The second magnetic layer 12 exists in the positive Z direction of the first inductor wiring 21 and the second inductor wiring 22 and a direction orthogonal to the positive Z direction.

[0144] When viewed from the Z direction, the first inductor wiring 21 extends linearly along the X direction. When viewed from the Z direction, a part of the second inductor wiring 22 extends linearly along the X direction, and the other part extends linearly along the Y direction, that is, extends in an L shape.

[0145] The thickness of the first and second inductor wirings 21, 22 is, for example, preferably 40 μm or more and 120 μm or less. 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.

[0146] The first and second inductor wirings 21 and 22 are made 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 and 22, and thus the inductor component 1 can be made low in height.

[0147] The first end of the first inductor wiring 21 is electrically connected to the first columnar wiring 31, and the second end of the first inductor wiring 21 is electrically connected to the second columnar wiring 32. That is, the first inductor wiring 21 has a pad portion with a large line width at both ends thereof, and the first and second columnar wirings 31 and 32 are directly connected to the pad portion.

[0148] The first end of the second inductor wiring 22 is electrically connected to the third columnar wiring 33. That is, the second inductor wiring 22 has a pad portion at the first end thereof, and the third columnar wiring 33 is directly connected to the pad portion. The second end of the second inductor wiring 22 is connected to the pad portion of the second end of the first inductor wiring 21, and is electrically connected to the second columnar wiring 32. When viewed in the Z direction, the first end of the first inductor wiring 21 and the first end of the second inductor wiring 22 are located on the same side of the green sheet 10.

[0149] The first inductor wiring 21 is formed into a quadrangle in a cross section orthogonal to the extending direction. The first inductor wiring 21 includes a first side surface 210 facing the positive Y direction, a second side surface 210 facing the negative Y direction, a bottom surface 211 facing the negative Z direction, and a top surface 212 facing the positive Z direction. The first side surface 210 need not be completely opposed to the positive Y direction, and can be slightly inclined with respect to the positive Y direction, that is, the first side surface 210 is substantially opposed to the positive Y direction. Similarly, the second side surface 210 is substantially opposed to the negative Y direction, the bottom surface 211 is substantially opposed to the negative Z direction, and the top surface 212 is substantially opposed to the positive Z direction.

[0150] Similarly, the second inductor wiring 22 is formed into a quadrangle in a cross section orthogonal to the extending direction. The second inductor wiring 22 includes a first side surface 220 facing the positive Y direction, a second side surface 220 facing the negative Y direction, a bottom surface 221 facing the negative Z direction, and a top surface 222 facing the positive Z direction.

[0151] Further, a wiring extending from a connection position of the first and second inductor wirings 21, 22 to the first to third columnar wirings 31 to 33 further extends toward the outside of the chip, and this wiring is exposed on the outside of the chip. That is, the first and second inductor wirings 21, 22 have an exposed portion exposed to the outside from a side surface parallel to the stacking direction of the inductor component 1. This wiring is a wiring connected to a power supply wiring at the time of additional plating after the shape of the first and second inductor wirings 21, 22 is formed in the manufacturing process of the inductor component 1. By this power supply wiring, additional plating can be easily performed in the inductor substrate state before the inductor component 1 is singulated, and the distance between wirings can be reduced. Further, the distance between wirings of the first and second inductor wirings 21, 22 is reduced by additional plating, and thus the magnetic coupling of the first and second inductor wirings 21, 22 can be improved.

[0152] 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 first columnar wiring 31 extends upward from the upper surface of one end of the first inductor wiring 21, and the end surface of the first columnar wiring 31 is exposed from the first main surface 10a of the blank 10 (also the main surface of the second magnetic layer 12). The second columnar wiring 32 extends upward from the upper surface of the other end of the first inductor wiring 21, and the end surface of the second columnar wiring 32 is exposed from the first main surface 10a of the blank 10. The third columnar wiring 33 extends upward from the upper surface of one end of the second inductor wiring 22, and the end surface of the third columnar wiring 33 is exposed from the first main surface 10a of the blank 10.

[0153] Therefore, the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33 extend in a straight line in a direction orthogonal to the first main surface 10a from the first inductor wiring 21 and the second inductor wiring 22 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. Further, the first to third columnar wirings 31 to 33 can be drawn in a straight line from the first and second inductor wirings 21, 22, and an increase in direct current resistance and a decrease in inductance acquisition efficiency due to additional winding can be suppressed. The first to third columnar wirings 31 to 33 are composed of an electrically conductive material, for example, the same material as the inductor wirings 21, 22. Further, the first to third columnar wirings 31 to 33 can be electrically connected to the first and second inductor wirings 21, 22 via a via conductor not shown.

[0154] 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, Cu which is excellent in low resistance and stress resistance, Ni which is excellent in corrosion resistance, and Au which is excellent in solder wettability and reliability, arranged in three layers from the inside to the outside.

[0155] The first external terminal 41 is in contact with the end surface of the first columnar wiring 31 exposed from the first main surface 10a of the green sheet 10, and is electrically connected to the first columnar wiring 31. Thus, the first external terminal 41 is electrically connected to one end of the first inductor wiring 21. The second external terminal 42 is in contact with the end surface of the second columnar wiring 32 exposed from the first main surface 10a of the green sheet 10, and is electrically connected to the second columnar wiring 32. Thus, the second external terminal 42 is electrically connected to the other end of the first inductor wiring 21 and the other end of the second inductor wiring 22. The third external terminal 43 is in contact with the end surface of the third columnar wiring 33, and is electrically connected to the third columnar wiring 33 and the one end of the second inductor wiring 22.

[0156] The coating film 50 is provided in the portion of the first main surface 10a of the green sheet 10 where the first to third external terminals 41 to 43 are not provided. However, the coating film 50 can also overlap the first to third external terminals 41 to 43 by being caught on the end portions of the first to third external terminals 41 to 43. The coating film 50 is composed of, for example, an acrylic resin, an epoxy-based resin, a polyimide, or the like, which is highly electrically insulating. Thus, the insulating properties between the first to third external terminals 41 to 43 can be improved. In addition, the coating film 50 functions as a mask when the pattern of the first to third external terminals 41 to 43 is formed, and thus the manufacturing efficiency is improved. In addition, in the case where the magnetic powder is exposed from the resin, the coating film 50 can prevent the magnetic powder from being exposed to the outside by covering the exposed magnetic powder. Furthermore, the coating film 50 can contain a filler composed of an insulating material.

[0157] The side surface insulating portions 61 cover only a portion of each of the two side surfaces 210 of the first inductor wiring 21. In addition, the side surface insulating portions 61 cover only a portion of each of the two side surfaces 220 of the second inductor wiring 22. The bottom surface insulating portion 62 covers the bottom surface 211 of the first inductor wiring 21. In addition, the bottom surface insulating portion 62 covers the bottom surface 221 of the second inductor wiring 22.

[0158] Figure 3 is a schematic cross-sectional view of the center in the direction in which the first inductor wiring 21 extends and orthogonal to the direction in which the first inductor wiring 21 extends. Figure 4 is an image diagram corresponding to Figure 3 Figure 3 ​In the drawing, the magnetic powder 100 on the left side of the first inductor wiring 21 is omitted from depiction, but is the same as on the right side of the first inductor wiring 21. Also, in addition, the cross-sectional view around the second inductor wiring 22 is the same, and the description thereof is omitted.

[0159] As shown in FIG. 1, the first magnetic layer 11 and the second magnetic layer 12 include a flat-shaped magnetic powder 100 and a resin 101 containing the magnetic powder 100. In the drawing, hatching of the magnetic powder 100 and the resin 101 is omitted from depiction. In the drawing, the magnetic powder 100 is shown as a white line. The flat-shaped magnetic powder 100 has at least one short axis, that is, at least one direction in which the size is smaller than the size in another direction, and for example, in three dimensions, can be a flat powder like a circular plate, or can be a flat powder like a needle. Also, the outer surface of the magnetic powder 100 can be smooth, or can have a concave-convex. Figure 3 Figure 4 As shown in FIG. 1, the first magnetic layer 11 and the second magnetic layer 12 include a flat-shaped magnetic powder 100 and a resin 101 containing the magnetic powder 100. In the drawing, hatching of the magnetic powder 100 and the resin 101 is omitted from depiction. In the drawing, the magnetic powder 100 is shown as a white line. The flat-shaped magnetic powder 100 has at least one short axis, that is, at least one direction in which the size is smaller than the size in another direction, and for example, in three dimensions, can be a flat powder like a circular plate, or can be a flat powder like a needle. Also, the outer surface of the magnetic powder 100 can be smooth, or can have a concave-convex. Figure 3 Figure 4 As shown in FIG. 1, the first magnetic layer 11 and the second magnetic layer 12 include a flat-shaped magnetic powder 100 and a resin 101 containing the magnetic powder 100. In the drawing, hatching of the magnetic powder 100 and the resin 101 is omitted from depiction. In the drawing, the magnetic powder 100 is shown as a white line. The flat-shaped magnetic powder 100 has at least one short axis, that is, at least one direction in which the size is smaller than the size in another direction, and for example, in three dimensions, can be a flat powder like a circular plate, or can be a flat powder like a needle. Also, the outer surface of the magnetic powder 100 can be smooth, or can have a concave-convex.

[0160] According to the above-described structure, since the first magnetic layer 11 and the second magnetic layer 12 include the flat-shaped magnetic powder 100, the demagnetizing field decreases, and a higher relative permeability is obtained. Also, since the first inductor wiring 21 is disposed between the first magnetic layer 11 and the second magnetic layer 12, the flat-shaped magnetic powder 100 can be disposed around the first inductor wiring 21. Thereby, the filling rate of the flat-shaped magnetic powder 100 is increased, the permeability around the first inductor wiring 21 can be increased, and the efficiency of obtaining inductance can be increased.

[0161] Also, the side surface insulating portion 61 contacts only a part of the side surface 210 of the first inductor wiring 21. Thereby, for example, even in the case where a plurality of magnetic powders 100 are electrically connected in the Y direction, a part of the side surface 210 of the first inductor wiring 21 does not contact the magnetic powder 100 by the side surface insulating portion 61. Thereby, the insulating property can be ensured.

[0162] Also, the side surface insulating portion 61 is composed of the same material as the resin 101 of the second magnetic layer 12. Thereby, the residual stress within the green body 10 can be reduced. Also, the side surface insulating portion 61 has an interface with the resin 101, but the side surface insulating portion 61 can not have an interface with the second magnetic layer 12, that is, the side surface insulating portion 61 can be integrally continuous with the resin 101 of the second magnetic layer 12.

[0163] Also, the bottom surface insulating portion 62 contacts the bottom surface 211 of the first inductor wiring 21. Thereby, the bottom surface 211 of the first inductor wiring 21 does not contact the magnetic powder 100 of the first magnetic layer 11 by the bottom surface insulating portion 62. Therefore, the insulating property can be increased.

[0164] ​​In addition, the side surface insulating portion 61 is in contact with the bottom surface insulating portion 62. That is, the side surface insulating portion 61 is in contact with a portion of the side surface 210 close to the bottom surface 211. Thereby, the corner between the side surface 210 and the bottom surface 211 of the first inductor wiring 21 can be covered by the side surface insulating portion 61 and the bottom surface insulating portion 62, and the insulating property can be further improved. That is, in the first magnetic layer 11, the long axis L of the magnetic powder 100 is arranged substantially in parallel with the bottom surface 211 of the first inductor wiring 21 (as shown in the drawing), and thus even if the plurality of magnetic powders 100 are electrically connected in the Y direction, the corner of the first inductor wiring 21 is not in contact with the magnetic powder 100 by the side surface insulating portion 61 and the bottom surface insulating portion 62. Figure 5

[0165] In addition, the composition of the side surface insulating portion 61 is different from that of the bottom surface insulating portion 62. For example, the resin of the side surface insulating portion 61 is different from that of the bottom surface insulating portion 62. Thereby, the design range of the side surface insulating portion 61 and the bottom surface insulating portion 62 is expanded. For example, by selecting a resin with high adhesiveness to the first inductor wiring 21 for the bottom surface insulating portion 62, the reliability of the inductor component 1 can be improved. In addition, by selecting a resin with characteristics (for example, thermal expansion rate, Young's modulus) that moderate stress for the side surface insulating portion 61, the residual stress of the inductor component 1 as a whole can be moderated.

[0166] In addition, the height T61 of the side surface insulating portion 61 in the Z direction is half or less of the height T21 of the first inductor wiring 21 in the Z direction. Preferably, the height T61 is 1 / 3 or less of the height T21. The heights T61, T21 are values measured in a cross section orthogonal to the direction in which the first inductor wiring 21 extends. Thereby, by reducing the height of the side surface insulating portion 61, the volume of the second magnetic layer 12 is increased, the insulating property is ensured, and the inductance acquisition efficiency is further improved.

[0167] Figure 5 is a partial enlarged view of Figure 3 As shown in Figure 3 and Figure 5 in a cross section orthogonal to the direction in which the first inductor wiring 21 extends (in this embodiment, the YZ cross section), the second magnetic layer 12 has a side surface vicinity region Z0 between the side surface 210 of the first inductor wiring 21 and a position separated by a prescribed distance d in the Y direction from the side surface 210.

[0168] ​Specifically, the region Z0 near the side is the area enclosed on the YZ cross-section by the side surface 210, a position separated from the side surface 210 by a predetermined distance d, an extension surface including the top surface 212, and an extension surface including the bottom surface 211. The distance from the side surface 210 of the first inductor wiring 21 is the distance from the end of the side surface 210 of the first inductor wiring 21 to the bottom surface 211. The predetermined distance d is 1 / 3 of the width W21 of the first inductor wiring 21 in the Y direction.

[0169] Furthermore, the angle θ formed by the major axis L of the flat magnetic powder 100 contained in the region Z0 near the side with respect to the side surface 210 is 45° or less. The major axis L of the magnetic powder 100 refers to the straight line passing through the longest part of the magnetic powder 100 in the aforementioned YZ cross-section. The angle θ refers to the angle on the bottom surface 211 side of the angle formed by the major axis L and the side surface 210, not the angle on the top surface 212 side.

[0170] like Figure 6 As shown, the method for deriving the angle θ described above involves acquiring an SEM image of a cross-section orthogonal to the extension direction of the first inductor wiring 21, binarizing the SEM image, representing white as magnetic powder and black as resin, and measuring the angle at which the major axis L of the magnetic powder intersects the side surface 210 of the first inductor wiring 21. The angle θ of the magnetic powder 100 separated from the side surface 210 is then determined based on the angle at which the straight line extending the major axis L of the magnetic powder 100 intersects the side surface 210.

[0171] Based on the above structure, since the angle θ is less than 45°, in the region Z0 near the side, the long axis L of the magnetic powder 100 is arranged approximately parallel to the side surface 210 of the first inductor wiring 21. Therefore, by alternately arranging the magnetic powder 100 and resin 101 along the Y direction in the region Z0 near the side, the inductance acquisition efficiency can be maintained and insulation can be ensured.

[0172] Furthermore, in the aforementioned YZ cross-section, the angle θ increases as it moves away from the side 210 of the first inductor wiring 21 in the Y direction. This increase in angle θ refers to a change in angle from 0° towards 90°.

[0173] According to the above structure, since the long axis L of the magnetic powder 100 is arranged approximately parallel to the side 210 in the vicinity of the side 210 of the first inductor wiring 21, the magnetic powder 100 and resin 101 are alternately arranged along the Y direction, which can maintain the inductance acquisition efficiency and ensure insulation.

[0174] Furthermore, in the aforementioned YZ cross section, the angle between the major axis L of the magnetic powder 100 contained in the first magnetic layer 11 and the bottom surface 211 is less than 45°.

[0175] According to the above structure, since the angle of the long axis L of the magnetic powder 100 with respect to the bottom surface 211 is 45° or less, the long axis L of the magnetic powder 100 is arranged substantially in parallel with the bottom surface 211 of the first inductor wiring 21. Therefore, the arrangement of the magnetic powder 100 is parallel to the magnetic flux, and a higher relative permeability can be obtained.

[0176] In addition, in a cross section (in the present embodiment, a YZ cross section) that is in the center of the direction in which the first inductor wiring 21 extends and is orthogonal to the direction in which the first inductor wiring 21 extends, when the maximum Feret length of the magnetic powder 100 is set to LF and the thickness of the magnetic powder 100 that is orthogonal to the maximum Feret length is set to TF, LF / TF ≥ 10, and the D90 of the maximum Feret length is 100 μm or less. The D90 of the maximum Feret length is found by acquiring SEM images in the above cross section at about three points in a 200 μm x 200 μm region and calculating the D90 thereof.

[0177] According to the above structure, since LF / TF ≥ 10, the flatness of the magnetic powder 100 can be increased, and thus a higher relative permeability can be obtained. In addition, since the D90 of the maximum Feret length is 100 μm or less, insulation can be ensured. For example, in the case where the maximum Feret length is excessively large, the possibility of short-circuiting between different inductor wirings or between turns of the same inductor wiring via the magnetic powder 100 becomes high.

[0178] Figure 7A is a plan view of the inductor component 1. Furthermore, in Figure 7A , the external terminals 41 to 43 and the coating film 50 are omitted from the drawing.

[0179] As shown in Figure 7A , when the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal to the main surface 12a, the second magnetic layer 12 has a dark region Za along the first and second inductor wirings 21 and 22 and a bright region Zb that is brighter than the dark region Za, the bright region Zb being a region other than the dark region Za. In Figure 7A , the dark region Za is shown by hatching. If described specifically, the dark region Za extends along the extension direction of the first and second inductor wirings 21 and 22, and when the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal thereto, the dark region Za is adjacent to the first and second inductor wirings 21 and 22.

[0180] According to the above structure, when viewed from a direction orthogonal to the main surface 12a of the second magnetic layer 12, the second magnetic layer 12 has a dark region Za along the first and second inductor wirings 21 and 22, and a bright region Zb outside the dark region Za. Therefore, in the main surface 12a of the second magnetic layer 12, the area directly above the bright region Zb appears brighter, and the area directly above the dark region Za appears darker. Thus, when the second magnetic layer 12 is manufactured by pressing it onto the first and second inductor wirings 21 and 22, it can be confirmed that the magnetic powder 100 contained in the second magnetic layer 12 is in the desired configuration.

[0181] In more detail, it can be determined that the long axis of the magnetic powder 100 contained in the bright region Zb is substantially parallel to the main surface 12a of the second magnetic layer 12, while the long axis of the magnetic powder 100 contained in the dark region Za is arranged in a direction substantially orthogonal to the main surface 12a of the second magnetic layer 12. That is, the magnetic powder 100 contained in the bright region Zb reflects light, therefore the area directly above the bright region Zb appears brighter, while the magnetic powder 100 contained in the dark region Za is less reflective of light, therefore the area directly above the dark region Za appears darker.

[0182] Therefore, the flat magnetic powder 100 has poor flowability compared to the approximately spherical magnetic powder 100, thus posing a problem in terms of filling performance. However, by observing the brightness and darkness of the main surface 12a of the second magnetic layer 12, it is easy to determine whether the magnetic powder 100 of the second magnetic layer 12 is filled in the desired configuration. This allows for non-destructive early detection of poor filling of the magnetic powder 100 and reduces manufacturing losses. Furthermore, it is preferable to observe the brightness and darkness of the main surface 12a of the second magnetic layer 12 before setting the external terminals 41-43 and the coating film 50.

[0183] The above method for identifying light and dark is explained. For example... Figure 7A As shown, the image was taken from a direction orthogonal to the main surface 12a of the second magnetic layer 12. Specifically, a VHX-5000 from KEYENCE was used for imaging with ring illumination. Then, a specified area of ​​the acquired image was selected, and the brightness distribution within that area was depicted. The brightness distribution was set to 255 grayscale. Then, binarization was performed. The binarization threshold was approximately half the range of 255. Figure 8 This indicates the image obtained in this way. For example... Figure 8 As shown, the area directly above the bright region Zb appears brighter. On the other hand, the area directly above the dark region Za appears darker.

[0184] like Figure 7A and Figure 3As shown, at least one of the first and second inductor wirings 21 and 22 and the first to third columnar wirings 31 to 33 is in contact with the magnetic powder 100. Thus, by eliminating unnecessary insulating portions, the efficiency of obtaining inductance can be improved. In addition, if a plurality of magnetic powders 100 are electrically connected in the Y direction, the turns of the same first inductor wiring 21 (or the same second inductor wiring 22) between different first and second inductor wirings 21 and 22 can possibly be short-circuited via the magnetic powder 100, but since the long axes of the magnetic powders 100 included in the dark region Za along the first and second inductor wirings 21 and 22 are arranged in a direction substantially orthogonal to the main surface 12a of the second magnetic layer 12, the possibility of short-circuiting is low even if at least one of the first and second inductor wirings 21 and 22 and the first to third columnar wirings 31 to 33 is in contact with the magnetic powder 100.

[0185] Figure 7B is a schematic cross-sectional view of the center of the direction in which the first inductor wiring 21 extends and orthogonal to the direction in which the first inductor wiring 21 extends. In addition, in Figure 7B , the external terminals 41 to 43 and the coating film 50 are omitted.

[0186] As shown in Figure 7B , the thickness T12 of the second magnetic layer 12 in the Z direction between the main surface 12a of the second magnetic layer 12 and the top surface 212 of the first inductor wiring 21 in the first direction is 3 times or less the height T21 of the first inductor wiring 21 in the Z direction. According to the above structure, the dark region Za and the bright region Zb can be easily confirmed in the main surface 12a of the second magnetic layer 12. That is, if the thickness T12 of the second magnetic layer 12 is too thick, since the long axes of the magnetic powders 100 included in the vicinity of the main surface 12a of the second magnetic layer 12 are arranged substantially in parallel to the main surface 12a of the second magnetic layer 12, the magnetic powders 100 included in the vicinity of the main surface 12a of the second magnetic layer 12 reflect light, and it is difficult to clearly determine the dark region Za in the main surface 12a of the second magnetic layer 12.

[0187] As shown in Figure 7BAs shown, the first magnetic layer 11 is flat. According to the above structure, in the first magnetic layer 11, the filling property of the magnetic powder 100 does not need to be considered in relation to the first and second inductor wirings 21, 22, and the material of the magnetic powder 100 can be freely selected. That is, the degree of freedom in the selection of the material of the magnetic powder 100 is improved. For example, by using a spherical metal magnetic material instead of a flat metal magnetic material as the magnetic powder 100, the direct current superposition can be improved. In addition, as the magnetic powder 100, a flat magnetic powder and a spherical magnetic powder can be mixed together. In addition, by using a rigid body such as a ferrite or a metal foil as the magnetic powder 100, the strength and the magnetic permeability can be improved. Furthermore, in the second magnetic layer 12 as well, as the magnetic powder 100, a flat magnetic powder and a spherical magnetic powder can be mixed together.

[0188] Figure 7C is a plan view of the inductor component 1. As shown, the first magnetic layer 11 is flat. According to the above structure, in the first magnetic layer 11, the filling property of the magnetic powder 100 does not need to be considered in relation to the first and second inductor wirings 21, 22, and the material of the magnetic powder 100 can be freely selected. That is, the degree of freedom in the selection of the material of the magnetic powder 100 is improved. For example, by using a spherical metal magnetic material instead of a flat metal magnetic material as the magnetic powder 100, the direct current superposition can be improved. In addition, as the magnetic powder 100, a flat magnetic powder and a spherical magnetic powder can be mixed together. In addition, by using a rigid body such as a ferrite or a metal foil as the magnetic powder 100, the strength and the magnetic permeability can be improved. Furthermore, in the second magnetic layer 12 as well, as the magnetic powder 100, a flat magnetic powder and a spherical magnetic powder can be mixed together. Figure 7C As shown, when the main surface 11a of the first magnetic layer 11 is observed from a direction orthogonal to the main surface 11a in the negative Z direction of the first magnetic layer 11, the first magnetic layer 11 has a first region Z1 along the first and second inductor wirings 21, 22, and a second region Z2 that cannot be distinguished from the first region Z1 in terms of brightness, the second region Z2 being a region other than the first region Z1. In the first magnetic layer 11, the first region Z1 is shown by hatching. When observed from a direction orthogonal to the main surface 11a, the first region Z1 overlaps with the dark region Za. Figure 7C As shown, when the main surface 11a of the first magnetic layer 11 is observed from a direction orthogonal to the main surface 11a in the negative Z direction of the first magnetic layer 11, the first magnetic layer 11 has a first region Z1 along the first and second inductor wirings 21, 22, and a second region Z2 that cannot be distinguished from the first region Z1 in terms of brightness, the second region Z2 being a region other than the first region Z1. In the first magnetic layer 11, the first region Z1 is shown by hatching. When observed from a direction orthogonal to the main surface 11a, the first region Z1 overlaps with the dark region Za.

[0189] If described concretely, the first region Z1 extends along the extension directions of the first and second inductor wirings 21, 22, and when observed from a direction orthogonal to the main surface 11a of the first magnetic layer 11, the first region Z1 is adjacent to the first and second inductor wirings 21, 22. The difference in brightness between the first region Z1 and the second region Z2 does not need to be 0, and a slight difference is allowed, and the first region Z1 and the second region Z2 are provided so as to be substantially indistinguishable in terms of brightness.

[0190] That is, since the long axis of the magnetic powder 100 included in the first magnetic layer 11 is arranged substantially in parallel with the main surface 11a of the first magnetic layer 11, the magnetic powder 100 included in the first magnetic layer 11 reflects light, and it is difficult to clearly determine the first region Z1 and the second region Z2 in the main surface 11a of the first magnetic layer 11.

[0191] According to the above structure, in the main surface 11a of the first magnetic layer 11, the directly above of the first region Z1 and the directly above of the second region Z2 appear to be the same brightness. Therefore, the upper and lower of the inductor component 1 can be easily distinguished in terms of appearance.

[0192] Preferably, the covered film 50 cannot distinguish the dark area Za and the bright area Zb. According to the above structure, in the appearance screening process after the manufacturing of the inductor component 1, it is possible to suppress excessive classification (excessive screening). For example, the covered film 50 is colored. If specifically described, the covered film 50 is colored with a pigment, such as titanium oxide, carbon black, or the like, so that the color of the substrate cannot be seen. In addition, the covered film 50 is preferably a resin of epoxy, benzene, liquid crystal polymer, imide, or a resin composed of a combination of them, and can be a resin other than these. In addition, the covered film 50 can be mixed with an inorganic filler to impart insulating properties and rigidity like silicon dioxide.

[0193] Preferably, the external terminals 41 to 43 are provided to the main surface 12a of the second magnetic layer 12, and the covered film 50 is arranged to a part of the main surface 12a of the second magnetic layer 12 so that the external terminals 41 to 43 are exposed, and the main surface 12a of the second magnetic layer 12 becomes the outermost surface of the blank 10. According to the above structure, by making the layer imparting the function to be the minimum, it is possible to reduce the manufacturing cost.

[0194] (MANUFACTURING METHOD)

[0195] Next, the manufacturing method of the inductor component 1 will be described. Figures 9A-9L Corresponding to Figure 1 the C-C cross section Figure 2C ).

[0196] As shown in Figure 9A , a base substrate 70 is prepared. The hardness of the base substrate 70 is higher than the hardness of the magnetic sheet constituting the first magnetic layer 11 and the second magnetic layer 12. The base substrate 70 is composed of, for example, a ferrite, a ceramic substrate such as alumina, a resin substrate such as glass epoxy, or the like.

[0197] As shown in Figure 9B , a first insulating layer 71 is applied to the main surface of the base substrate 70 to cure the first insulating layer 71. Further, a second insulating layer is applied to the first insulating layer 71, a predetermined pattern is formed on the second insulating layer using a photolithography method, and cured, whereby a bottom surface insulating portion 62 is formed.

[0198] As shown in Figure 9C , on the first insulating layer 71 and the bottom surface insulating portion 62, a seed layer not shown is formed by a known method such as sputtering or evaporation. Thereafter, a DFR (dry film resist) 75 is laminated, and a predetermined pattern is formed on the DFR 75 using a photolithography method. The predetermined pattern is a through hole corresponding to the position where the first inductor wiring 21 and the second inductor wiring 22 are to be provided on the bottom surface insulating portion 62.

[0199] As shown in Figure 9DAs shown, a first inductor wiring 21 and a second inductor wiring 22 are formed on the bottom insulating portion 62 using electroplating via a seed layer. 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.

[0200] Next, the DFR75 is stacked again, and a predetermined pattern is formed on the DFR75 using photolithography. The predetermined pattern consists of through-holes corresponding to the positions of the first and second columnar wirings 31 and 32 and the third columnar wiring 33 on the first inductor wiring 21 and the second inductor wiring 22. Then, as... Figure 9E As shown, a first pillared wiring 31, a second pillared wiring 32, and a third pillared wiring 33 are formed on the first inductor wiring 21 and the second inductor wiring 22 using electroplating. Afterwards, the DFR75 is stripped. Alternatively, a seed layer can be used for electroplating, in which case the seed layer needs to be etched.

[0201] Subsequently, a magnetic sheet 80 comprising flat magnetic powder 100 and resin 101 containing magnetic powder 100 is pressed from above the main surface of the substrate 70 toward the first inductor wiring 21 and the second inductor wiring 22, as shown in the figure. Figure 9F As shown, a magnetic sheet 80 covers the top surface 212 and side surface 210 of the first inductive wiring 21 and the top surface 222 and side surface 220 of the second inductive wiring 22. This magnetic sheet 80 constitutes the second magnetic layer 12. Simultaneously, the resin 101 contained in the magnetic sheet 80 is pushed out from the magnetic sheet 80 so that it only covers a portion of the side surface 210 of the first inductive wiring 21 and a portion of the side surface 220 of the second inductive wiring 22, forming a side insulating portion 61. Figure 9E and Figure 9F In the image, the magnetic powder 100 is shown along its long axis.

[0202] In other words, such as Figure 9E As shown, before pressing the magnetic sheet 80, the long axis of the magnetic powder 100 of the magnetic sheet 80 is arranged along the horizontal direction (Y direction), but as... Figure 9F As shown, when the magnetic sheet 80 is pressed, the long axis of the magnetic powder 100 of the magnetic sheet 80 is aligned along the direction in which the magnetic sheet 80 deforms due to downward pressure. At this time, since the hardness of the substrate 70 is higher than that of the magnetic sheet 80, when the magnetic sheet 80 is pressed onto the first inductor wiring 21 and the second inductor wiring 22, the resin 101 contained in the magnetic sheet 80 can be effectively pushed only onto a portion of the side surface 210 of the first inductor wiring 21 and a portion of the side surface 220 of the second inductor wiring 22. Therefore, the side insulating portion 61 can be effectively formed simultaneously with the pressing of the magnetic sheet 80.

[0203] Next, the magnetic sheet 80 is observed from above, and the presence of magnetic powder 100 is identified and checked by observing the light and dark areas. Specifically, when the magnetic sheet 80 is observed from above, a dark area Za is formed along the side 210 of the first inductor wiring 21 and the side 220 of the second inductor wiring 22, and a bright area Zb is formed outside the dark area Za. Thus, by observing the magnetic sheet 80 from above to confirm the light and dark areas, it is easy to determine whether magnetic powder 100 is filled in the side 210 of the first inductor wiring 21 and the side 220 of the second inductor wiring 22. This allows for non-destructive detection of poor filling of magnetic powder 100 during the manufacturing stage of the inductor component 1, reducing manufacturing losses.

[0204] After that, as Figure 9G As shown, the magnetic sheet 80 is ground to form a second magnetic layer 12, exposing the end faces of the first columnar wiring 31, the second columnar wiring 32, and the third columnar wiring 33. Alternatively, the grinding process of the magnetic sheet 80 can be performed before the aforementioned inspection process.

[0205] After that, as Figure 9H As shown, a third insulating layer is coated on the upper surface of the second magnetic layer 12, and a predetermined pattern is formed on the third insulating layer using photolithography and then cured, thereby forming a coating film 50. The predetermined pattern consists of through holes corresponding to the end faces of the columnar wirings 31-33 and the positions on the second magnetic layer 12 where the first external terminal 41, the second external terminal 42, and the third external terminal 43 are located.

[0206] After that, as Figure 9I As shown, the substrate 70 and the first insulating layer 71 are removed by grinding. Alternatively, 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.

[0207] After that, as Figure 9J As shown, other magnetic sheets 80 are pressed onto the first inductor wiring 21 and the second inductor wiring 22 from below, covering the bottom surface 211 of the first inductor wiring 21 and the bottom surface 221 of the second inductor wiring 22. The other magnetic sheets 80 are ground to a predetermined thickness to form the first magnetic layer 11. Figure 9J In the image, the magnetic powder 100 is shown along its long axis. Before and after the magnetic sheet 80 is pressed, the long axis of the magnetic powder 100 of the magnetic sheet 80 is arranged along the horizontal direction (Y direction). In this way, the first inductor wiring 21 and the second inductor wiring 22 can be clamped by the upper and lower magnetic sheets 80, which can improve the efficiency of inductance acquisition.

[0208] After that, as shown in Figure 9K , a metal film is formed by electroless plating from the columnar wires 31 to 33 into the through holes of the coating film 50, and the first external terminal 41, the second external terminal 42, and the third external terminal 43 are formed.

[0209] After that, as shown in Figure 9L , the inductor component 1 is singulated at the cut line D, and as shown in Figure 2C , the inductor component 1 is manufactured.

[0210] (Second Embodiment)

[0211] Figure 10 is a plan view showing the second embodiment of the inductor component 1A. Figure 11A is an A-A sectional view of Figure 10 . Figure 11B is a B-B sectional view of Figure 10 . The structure of the inductor wire and the insulating portion of the second embodiment is different from that of the first embodiment. The different structure will be described below. Further, the other configurations are the same as those of the first embodiment, and therefore the same reference numerals are assigned and the description thereof is omitted.

[0212] As shown in Figure 10 , Figure 11A , and Figure 11B , the inductor component 1A of the second embodiment has one inductor wire 21A. The inductor wire 21A is a wire that is formed only on the upper side of the first magnetic layer 11, specifically, only on the bottom surface insulating portion 62 disposed on the upper surface of the first magnetic layer 11, and extends in a spiral shape along the upper surface of the first magnetic layer 11. The inductor wire 21A is a spiral shape having more than one turn. When viewed from the upper side, the inductor wire 21A is wound in a spiral shape in a clockwise direction from the inner peripheral end toward the outer peripheral end. The outer peripheral end of the inductor wire 21A is connected to the first columnar wire 31, and the inner peripheral end of the inductor wire 21A is connected to the second columnar wire 32. Further, in the drawing, the coating film and the external terminals are omitted from the depiction.

[0213] The inductor component 1A further has a peripheral surface insulating portion 63 that is in contact with the side surface 210 and the top surface 212 of the inductor wire 21A. The peripheral surface insulating portion 63 is present between the side surface insulating portion 61 and a portion of the side surface 210 of the inductor wire 21A, and the side surface insulating portion 61 covers only a portion of the side surface 210 of the inductor wire 21A together with the peripheral surface insulating portion 63.

[0214] The circumferential surface insulating portion 63 is different in composition from the side surface insulating portion 61 and the bottom surface insulating portion 62. For example, the resin of the circumferential surface insulating portion 63 is different from the resin of the side surface insulating portion 61 and the resin of the bottom surface insulating portion 62. Thereby, the design range of the circumferential surface insulating portion 63, the side surface insulating portion 61, and the bottom surface insulating portion 62 is expanded.

[0215] The thickness of the side surface insulating portion 61 is thicker than the thickness of the circumferential surface insulating portion 63. The thickness refers to the maximum value measured in a cross section orthogonal to the direction in which the inductor wiring 21A extends. Thereby, the insulating property can be further improved.

[0216] Figure 12 is a plan view of the inductor component 1A. Furthermore, in the drawing, the cover film and the external terminal are omitted to be depicted.

[0217] As shown in Figure 12 When the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal to the main surface 12a of the second magnetic layer 12, the second magnetic layer 12 has a dark region Za along the inductor wiring 21A, and a bright region Zb brighter than the dark region Za, which is a region other than the dark region Za. If described specifically, the dark region Za extends along the extension direction of the inductor wiring 21A, and when the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal to the main surface 12a of the second magnetic layer 12, the dark region Za is adjacent to the inductor wiring 21A. The bright region Zb is present between the adjacent turns in the inductor wiring 21A. That is, the dark region Za is provided along the inner circumferential surface and the outer circumferential surface of the inductor wiring 21A.

[0218] According to the above structure, when the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal to the main surface 12a of the second magnetic layer 12, the second magnetic layer 12 has a dark region Za along the inductor wiring 21A, and a bright region Zb of a region other than the dark region Za, and thus in the main surface 12a of the second magnetic layer 12, the directly above of the bright region Zb looks brighter, and the directly above of the dark region Za looks darker. Thereby, when the second magnetic layer 12 is crimped to the inductor wiring 21A to be manufactured, it is possible to confirm that the magnetic powder 100 included in the second magnetic layer 12 becomes the desired arrangement. Thus, it is possible to non-destructively detect early filling failure of the magnetic powder 100, and it is possible to reduce the manufacturing loss of products.

[0219] (Third Embodiment)

[0220] Figure 13A is a cross-sectional view showing the third embodiment of the inductor component 1B. The structure of the inductor wiring of the third embodiment is different from that of the first embodiment. The different structure will be described below. Furthermore, the other configurations are the same as those of the first embodiment, and thus the same reference numerals are given to the same components as those of the first embodiment, and the description thereof is omitted.

[0221] Figure 13A is a cross-sectional view of the center of the direction in which the first inductor wiring 21B extends and orthogonal to the direction in which the first inductor wiring 21B extends. Further, in Figure 13A , the external terminal and the coating film are omitted to be depicted.

[0222] As Figure 13A shown, the first inductor wiring 21B is formed into a triangle in a cross section orthogonal to the direction of extension. The first inductor wiring 21B includes a first side surface 210 facing the positive Y direction, a second side surface 210 facing the negative Y direction, and a bottom surface 211 facing the negative Z direction. The side surface 210 corresponds to the hypotenuse of the triangle. Although not shown, the second inductor wiring is also the same structure.

[0223] Figure 13B is a plan view of the inductor component. Further, in Figure 13B , the external terminal and the coating film are omitted to be depicted.

[0224] As Figure 13B shown, when the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal to the main surface 12a of the second magnetic layer 12, the second magnetic layer 12 has a dark region Za along the first inductor wiring 21B, and a bright region Zb brighter than the dark region Za, the bright region Zb being a region other than the dark region Za. If described specifically, the dark region Za extends along the direction of extension of the first inductor wiring 21B, and when the main surface 12a of the second magnetic layer 12 is observed from a direction orthogonal to the main surface 12a of the second magnetic layer 12, the dark region Za overlaps at least a part (in this embodiment, all) of the first inductor wiring 21B. That is, the long axis of the magnetic powder 100 included in the region along the side surface 210 is disposed along the side surface 210 inclined with respect to the horizontal direction (Y direction), and thus the magnetic powder 100 included in the region is difficult to reflect light, and the region becomes the dark region Za.

[0225] Further, 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 feature points of each of the first to third embodiments can be variously combined.

[0226] In the above-described first to third embodiments, the number of layers of the inductor wiring is one layer, but can also be a multilayer structure of two or more layers. That is, the inductor wiring can also be disposed in multiple along the positive Z direction, and at this time, the dark region is a region along the outermost inductor wiring in the positive Z direction. According to the above-described structure, by layering the inductor wiring, it is possible to reduce the influence on the mounting area. Also, if the inductor wiring after layering is connected in series, it is possible to increase the inductance.

[0227] In the first embodiment described above, two inductance wirings, the first inductance wiring and the second inductance wiring, are arranged in the green sheet, but three or more inductance wirings can be arranged, in which case, the external terminals and the columnar wiring are also four or more, respectively.

[0228] In the first embodiment described above and the second embodiment described above, the "inductance wiring" refers to a structure that imparts inductance to the inductor component by generating magnetic flux in the magnetic layer in the case where current flows, and is not particularly limited in configuration, shape, material, and the like. In particular, it is not limited to a straight line, a curved line (spiral = two-dimensional curve) that extends in a plane as in the embodiments, and various known wiring shapes such as a meandering wiring can be used.

[0229] In the first embodiment to the third embodiment described above, the side surface insulating portion, the bottom surface insulating portion, and the circumferential surface insulating portion are provided, but at least one of these insulating portions can be provided, or all of the insulating portions can not be provided.

Claims

1. An inductor component, comprising: a blank having a first magnetic layer and a second magnetic layer stacked in order along a first direction; and an inductor wiring disposed on a plane orthogonal to the first direction between the first magnetic layer and the second magnetic layer, the first magnetic layer including a magnetic powder and a resin containing the magnetic powder, the second magnetic layer including a flat-shaped magnetic powder and a resin containing the magnetic powder, the first magnetic layer being present in a direction opposite to the first direction of the inductor wiring, the second magnetic layer being present in the first direction of the inductor wiring and a direction orthogonal to the first direction, the second magnetic layer having, when the main surface of the second magnetic layer is observed from a direction orthogonal to the main surface of the second magnetic layer in the first direction, a dark region along the inductor wiring and a bright region brighter in brightness than the dark region, the bright region being a region other than the dark region, the inductor wiring including a side surface toward a direction orthogonal to the first direction, the inductor component further comprising a side surface insulating portion covering only a part of the side surface, a height of the side surface insulating portion in the first direction being half or less of a height of the inductor wiring in the first direction, and a part of the side surface of the inductor wiring not covered by the side surface insulating portion being in contact with the second magnetic layer.

2. The inductor component according to claim 1, wherein a thickness of the second magnetic layer in the first direction between the main surface of the second magnetic layer and a top surface of the inductor wiring in the first direction is three times or less of the height of the inductor wiring in the first direction.

3. The inductor component according to claim 1, wherein the blank further comprises a coating film covering the main surface of the second magnetic layer, and the dark region and the bright region cannot be distinguished through the coating film.

4. The inductor component according to claim 3, wherein the main surface of the second magnetic layer further comprises an external terminal electrically connected to the inductor wiring, the coating film is disposed on a part of the main surface of the second magnetic layer so that the external terminal is exposed, and a main surface of the first magnetic layer in a direction opposite to the first direction becomes a surface of the blank.

5. The inductor component according to any one of claims 1 to 4, wherein the first magnetic layer is a flat plate.

6. The inductor component according to claim 5, wherein the first magnetic layer has, when the main surface of the first magnetic layer is observed from a direction orthogonal to the main surface of the first magnetic layer in the first direction, a first region along the inductor wiring and a second region indistinguishable in brightness from the first region, the second region being a region other than the first region.

7. The inductor component according to any one of claims 1 to 4, further comprising a columnar wiring connected to the inductor wiring and extending in the first direction to penetrate the second magnetic layer. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8. The inductor component according to claim 7, wherein At least one of the inductor wiring and the columnar wiring is in contact with the magnetic powder.

9. The inductor component according to claim 1, wherein The inductor wiring includes a bottom surface facing in the opposite direction of the first direction, The inductor component further includes a bottom surface insulating portion in contact with the bottom surface.

10. The inductor component according to claim 9, wherein The inductor wiring includes a top surface facing in the first direction, The inductor component further includes a circumferential surface insulating portion in contact with the side surface and the top surface, The circumferential surface insulating portion is composed of a different material from the side surface insulating portion and the bottom surface insulating portion, The side surface insulating portion is thicker than the circumferential surface insulating portion.

11. The inductor component according to any one of claims 1 to 4, wherein The inductor wiring includes a side surface facing in a direction orthogonal to the first direction, In a cross section orthogonal to the direction in which the inductor wiring extends, The second magnetic layer has a side surface vicinity region between the side surface of the inductor wiring and a position separated by a prescribed distance from the side surface in the direction orthogonal to the first direction, An angle formed by a long axis of the flat-shaped magnetic powder included in the side surface vicinity region with respect to the side surface is 45° or less.

12. The inductor component according to any one of claims 1 to 4, wherein The inductor wiring includes a side surface facing in a direction orthogonal to the first direction, In a cross section orthogonal to the direction in which the inductor wiring extends, An angle formed by a long axis of the flat-shaped magnetic powder included in the second magnetic layer with respect to the side surface becomes larger as it moves away from the side surface of the inductor wiring in the direction orthogonal to the first direction.

13. The inductor component according to any one of claims 1 to 4, wherein The first magnetic layer includes flat-shaped magnetic powder, The inductor wiring includes a bottom surface facing in the opposite direction of the first direction, In a cross section orthogonal to the direction in which the inductor wiring extends, An angle formed by a long axis of the flat-shaped magnetic powder included in the first magnetic layer with respect to the bottom surface is 45° or less.

14. The inductor component according to any one of claims 1 to 4, wherein In a cross section in the center of the direction in which the inductor wiring extends and orthogonal to the direction in which the inductor wiring extends, When the maximum Feret length of the magnetic powder is set as LF and the thickness of the magnetic powder orthogonal to the maximum Feret length is set as TF, LF / TF ≥ 10, and the D90 of the maximum Feret length is 100 μm or less.

15. The inductor component according to any one of claims 1 to 4, wherein In each of the first magnetic layer and the second magnetic layer, the porosity is 1 vol% or more and 10 vol% or less.

16. The inductor component according to any one of claims 1 to 4, wherein A plurality of the inductor wirings are arranged along the first direction, The above-mentioned dark portion region is a region along the above-mentioned inductance wiring located at the outermost side in the above-mentioned first direction.

17. A method of manufacturing an inductor component, the inductor component being the inductor component according to any one of claims 1 to 16, The method of manufacturing the inductor component comprises: a step of forming an inductance wiring on a main surface of a base substrate; The magnetic sheet is pressure-bonded to the inductor wiring from above the main surface of the base substrate, and the top surface and the side surface of the inductor wiring are covered with the magnetic sheet. The above-mentioned magnetic sheet contains a flat-shaped magnetic powder and a resin containing the above-mentioned magnetic powder; and A step of identifying and inspecting whether the above-mentioned side surface of the above-mentioned inductance wiring is filled with the above-mentioned magnetic powder by light and shade, by observing the above-mentioned magnetic sheet from above the above-mentioned magnetic sheet.

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