Inductor component

Abstract

Provided is an inductor component which can improve the inductance value. The inductor component comprises: an element body including a magnetic layer; a coil that is disposed in the element body and that has an axis; and an insulating layer that covers a portion of the outer surface of the coil. The coil has an inductor wire wound along a flat surface orthogonal to the axis. The inductor wire has a first surface and a second surface that are axially opposite to each other. At least a portion of the first surface of the inductor wire is in contact with the magnetic layer.

Description

Inductor Components

[0001] The present disclosure relates to inductor components.

[0002] A conventional inductor component is described in Japanese Patent Laid-Open No. 2021-174799 (Patent Document 1). The inductor component includes an element body including a magnetic layer and a coil disposed within the element body and having an axis. The entire outer surface of the coil is covered with an insulating material.

[0003] Japanese Patent Application Laid-Open No. 2021-174799

[0004] However, in conventional inductor components, the entire outer surface of the coil is covered with an insulating material, which makes it difficult to ensure the volume of the magnetic layer, and in some cases makes it impossible to obtain the desired inductance value.

[0005] Therefore, an object of the present disclosure is to provide an inductor component that can improve the inductance value.

[0006] In order to solve the above problem, an inductor component that is one aspect of the present disclosure comprises: a base body including a magnetic layer; a coil disposed within the base body and having an axis; and an insulating layer covering a portion of the outer surface of the coil, wherein the coil has inductor wiring wound along a plane perpendicular to the axis, the inductor wiring having first and second surfaces that face each other in the axial direction, and at least a portion of the first surface of the inductor wiring contacts the magnetic layer.

[0007] According to the above aspect, since at least a portion of the first surface of the inductor wiring is in contact with the magnetic layer, the volume of the magnetic layer can be increased compared to when the entire outer surface of the inductor wiring is covered with an insulating material, thereby improving the inductance value of the inductor component.

[0008] According to an inductor component according to one aspect of the present disclosure, the inductance value can be improved.

[0009] FIG. 1 is a schematic plan view showing a first embodiment of an inductor component. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1 . FIG. 3 is an enlarged view of part A of FIG. 2 . FIG. 4 is a schematic cross-sectional view showing a modified example of an inductor component. FIG. 5 is an explanatory diagram illustrating a manufacturing method of an inductor component. FIG. 6 is an explanatory diagram illustrating a manufacturing method of an inductor component. FIG. 7 is an explanatory diagram illustrating a manufacturing method of an inductor component. FIG. 8 is an explanatory diagram illustrating a manufacturing method of an inductor component. FIG. 9 is an explanatory diagram illustrating a manufacturing method of an inductor component. FIG. 10 is an explanatory diagram illustrating a manufacturing method of an inductor component. FIG. 11 is an explanatory diagram illustrating a manufacturing method of an inductor component.

[0010] Hereinafter, an inductor component according to one aspect of the present disclosure will be described in detail with reference to the illustrated embodiments. Note that the drawings include some schematic views and may not reflect actual dimensions or proportions.

[0011] <First embodiment> (Configuration) Fig. 1 is a schematic plan view showing a first embodiment of an inductor component. Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1. For convenience, Fig. 1 has diagonal lines indicating the location of the top surface of the covering insulating layer. For convenience, Fig. 2 omits the seed layer. Fig. 2 corresponds to an example of a "cross section perpendicular to the extending direction of the inductor wiring" as set forth in the claims.

[0012] The inductor component 1 is mounted in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, car electronics, etc., and is, for example, a component having an overall rectangular parallelepiped shape. However, the shape of the inductor component 1 is not particularly limited, and may be a cylindrical shape, a polygonal columnar shape, a truncated cone shape, or a truncated polygonal cone shape.

[0013] 1 and 2 , the inductor component 1 comprises an element body 10, a coil 15 disposed within the element body 10 and having an axis AX, a covering insulating layer 30 and an underlying insulating layer 70 covering part of the outer surface of the coil 15, a first external terminal 51 and a second external terminal 52 exposed on the first main surface 10a of the element body 10, and a covering film 60 provided on the first main surface 10a of the element body 10. The covering insulating layer 30 and the underlying insulating layer 70 correspond to examples of the "insulating layer" set forth in the claims.

[0014] The shape of the element body 10 is not particularly limited, but in this embodiment, it is a rectangular parallelepiped. The outer surfaces of the element body 10 include a first main surface 10a and a second main surface 10b, and a first side surface 10c, a second side surface 10d, a third side surface 10e, and a fourth side surface 10f located between the first main surface 10a and the second main surface 10b and connecting the first main surface 10a and the second main surface 10b. The first main surface 10a and the second main surface 10b face each other. The first side surface 10c and the second side surface 10d face each other. The third side surface 10e and the fourth side surface 10f face each other.

[0015] In the drawings, the thickness direction of the element body 10 is the Z direction, the direction from the second main surface 10b toward the first main surface 10a is the forward Z direction, and the reverse direction of the forward Z direction is the reverse Z direction. In this specification, the main surface side of the first main surface 10a or the second main surface 10b on which the external terminals 51 and 52 are provided is referred to as the upper side. In this embodiment, the forward Z direction is the upper side. In a plane of the element body 10 perpendicular to the Z direction, the longitudinal direction of the element body 10, in which the first external terminals 51 and the second external terminals 52 are aligned, is referred to as the X direction, and the width direction of the element body 10, which is perpendicular to the longitudinal direction, is referred to as the Y direction. Furthermore, the X direction, from the first side surface 10c toward the second side surface 10d, is referred to as the forward X direction, and the reverse direction of the forward X direction is referred to as the reverse X direction. In the Y direction, from the third side surface 10e toward the fourth side surface 10f is referred to as the forward Y direction, and the reverse direction of the forward Y direction is referred to as the reverse Y direction. The forward Z direction corresponds to an example of a "first direction" in the claims, and the reverse Z direction corresponds to an example of a "second direction" in the claims.

[0016] The base body 10 includes a first magnetic layer 11 and a second magnetic layer 12 arranged in that order along the forward Z direction. This "in that order" simply indicates the positional relationship between the first magnetic layer 11 and the second magnetic layer 12, and is not related to the order in which the first magnetic layer 11 and the second magnetic layer 12 are formed. The first magnetic layer 11 and the second magnetic layer 12 correspond to an example of a "magnetic layer" as defined in the claims.

[0017] The first magnetic layer 11 and the second magnetic layer 12 each contain a magnetic powder and a resin containing the magnetic powder. The resin is, for example, an organic insulating material such as epoxy, a mixture of epoxy and acrylic, or a mixture of epoxy, acrylic, and other materials. The magnetic powder is, for example, an FeSi-based alloy such as FeSiCr, an FeCo-based alloy, an Fe-based alloy such as NiFe, or an amorphous alloy thereof. The magnetic powder may be ferrite. The average particle size of the magnetic powder is preferably 5 μm or less. Note that the first magnetic layer 11 and the second magnetic layer 12 may not contain an organic resin, such as a sintered body of ferrite or magnetic powder.

[0018] The coil 15 includes an inductor wiring 150 and first and second escape wirings 21 and 22 provided within the element body 10 so that their end faces are exposed from the first main surface 10a of the element body 10. The inductor wiring refers to wiring wound in a spiral shape on a plane including an inner peripheral end 151 and an outer peripheral end 152. The coil is a component including not only the inductor wiring but also wiring (in this embodiment, the first and second escape wirings 21 and 22) that extracts the signal of the inductor wiring to the outside of the element body 10. The inductor wiring 150 is wound between the first magnetic layer 11 and the second magnetic layer 12 along a plane (XY plane) perpendicular to the axis AX of the coil 15. Specifically, the first magnetic layer 11 is located in the reverse Z direction relative to the inductor wiring 150, and the second magnetic layer 12 is located in the forward Z direction relative to the inductor wiring 150 and in a direction perpendicular to the forward Z direction.

[0019] The inductor wiring 150 is spirally wound clockwise from the outer peripheral end 152 to the inner peripheral end 151 as viewed in the Z direction. The number of turns of the inductor wiring 150 is preferably one or more. This improves the inductance value. "One or more turns" refers to a state in which, in a cross section perpendicular to the axis of the inductor wiring, the inductor wiring has portions that are adjacent in the radial direction as viewed from the axial direction and run parallel to the winding direction. "Less than one turn" refers to a state in which, in a cross section perpendicular to the axis, the inductor wiring does not have portions that are adjacent in the radial direction as viewed from the axial direction and run parallel to the winding direction. In this embodiment, the number of turns of the inductor wiring 150 is 2.5 turns.

[0020] The inductor wiring 150 has a top surface 150a and a bottom surface 150b that face each other in the axial AX direction of the coil 15. Specifically, the inductor wiring 150 has a top surface 150a facing the forward Z direction (i.e., upward) and a bottom surface 150b facing the reverse Z direction. In this specification, the top surface 150a of the inductor wiring 150 does not include the connection portions with the first and second escape wirings 21 and 22. The top surface 150a corresponds to an example of a "first surface" as defined in the claims. The bottom surface 150b corresponds to an example of a "second surface" as defined in the claims. The inductor wiring 150 has two side surfaces 150c and 150d that connect the top surface 150a and the bottom surface 150b. Specifically, the inductor wiring 150 has a first side surface 150c facing radially outward and a second side surface 150d facing radially inward.

[0021] The outer peripheral end 152 of the inductor wiring 150 is connected to the first external terminal 51 via the first escape wiring 21 that contacts the top surface of the outer peripheral end 152. The inner peripheral end 151 of the inductor wiring 150 is connected to the second external terminal 52 via the second escape wiring 22 that contacts the top surface of the inner peripheral end 151. With the above configuration, the inductor wiring 150 is electrically connected to the first external terminal 51 and the second external terminal 52.

[0022] The inductor wiring 150 is preferably made of Au, Pt, Pd, Ag, Cu, Al, Co, Cr, Zn, Ni, Ti, W, Fe, Sn, In, or a compound thereof. The inductor wiring 150 is formed by, for example, electrolytic plating. The inductor wiring 150 may also be formed by electroless plating, sputtering, vapor deposition, coating, or the like.

[0023] The first escape routing 21 extends in the forward Z direction from the top surface of the outer peripheral end 152 of the inductor routing 150 and penetrates the interior of the covering insulating layer 30 and the second magnetic layer 12. The first escape routing 21 is preferably made of Cu, Ag, Au, Fe, or a compound thereof. The first escape routing 21 includes a first via routing 212 provided on the top surface of the outer peripheral end 152 of the inductor routing 150 and penetrating the interior of the covering insulating layer 30, and a first columnar routing 211 extending in the forward Z direction from the top surface of the first via routing 212 and penetrating the interior of the second magnetic layer 12, with an end face exposed on the first main surface 10a of the element body 10. The via routing is a conductor having a smaller line width (diameter, cross-sectional area) than the columnar routing.

[0024] The second escape routing 22 extends in the forward Z direction from the top surface of the inner circumferential end 151 of the inductor routing 150 and penetrates the inside of the covering insulating layer 30 and the second magnetic layer 12. The second escape routing 22 is preferably made of Cu, Ag, Au, Fe, or a compound thereof. The second escape routing 22 includes a second via routing 222 provided on the top surface of the inner circumferential end 151 of the inductor routing 150 and penetrating the inside of the covering insulating layer 30, and a second columnar routing 221 extending in the forward Z direction from the top surface of the second via routing 222 and penetrating the inside of the second magnetic layer 12, with its end face exposed on the first main surface 10 a of the element body 10. The first and second escape routings 21 and 22 are preferably made of the same material as the inductor routing 150.

[0025] The first and second external terminals 51, 52 are provided on the first main surface 10a of the element body 10. The first and second external terminals 41, 42 are made of a conductive material, and have a three-layer structure in which, from the inside to the outside, Cu, which has low electrical resistance and excellent stress resistance, Ni, which has excellent corrosion resistance, and Au, which has excellent solder wettability and reliability, are arranged in this order.

[0026] The first external terminal 51 contacts an end face of the first escape routing 21 exposed from the first main surface 10a of the element body 10, and is electrically connected to the first escape routing 21. As a result, the first external terminal 51 is electrically connected to an outer peripheral end 152 of the inductor routing 150. The second external terminal 52 contacts an end face of the second escape routing 22 exposed from the first main surface 10a of the element body 10, and is electrically connected to the second escape routing 22. As a result, the second external terminal 52 is electrically connected to an inner peripheral end 151 of the inductor routing 150. Note that in FIG. 1 , the first and second external terminals 51, 52 are shown by two-dot chain lines for convenience.

[0027] The covering insulating layer 30 and the underlying insulating layer 70 are made of an insulating material that does not contain a magnetic material, and the insulating material is preferably made of, for example, epoxy, acrylic, phenol, polyimide, or a mixture thereof.

[0028] Fig. 3 is an enlarged view of part A in Fig. 2. As shown in Fig. 3, at least a portion of the top surface 150a of the inductor wiring 150 is in contact with at least one of the first magnetic layer 11 and the second magnetic layer 12. In this embodiment, only a portion of the top surface 150a of the inductor wiring 150 is in contact with the second magnetic layer 12.

[0029] Specifically, the base insulating layer 70 is stacked on the first magnetic layer 11 so as to cover the entire upper surface of the first magnetic layer 11. The inductor wiring 150 is stacked on the base insulating layer 70. The entire bottom surface 150b of the inductor wiring 150 is in contact with the upper surface of the base insulating layer 70.

[0030] The covering insulating layer 30 is provided on the base insulating layer 70 and covers part of the outer surface of the inductor wiring 150. The covering insulating layer 30 has a top surface portion 31 and a wall portion 32.

[0031] The wall portion 32 is provided on at least one of the first side surface 150c and the second side surface 150d of the inductor wiring 150. In this embodiment, the wall portion 32 is provided on both the first side surface 150c and the second side surface 150d. The wall portion 32 extends in the Z direction in a cross section perpendicular to the extension direction of the inductor wiring 150 (i.e., the cross section shown in FIG. 2). The wall portion 32 is in contact with the entire surface of the first side surface 150c and the entire surface of the second side surface 150d. The lower surface of the wall portion 32 is in contact with the upper surface of the base insulating layer 70. In short, the wall portion 32 is provided on an inner peripheral surface 150d1 of the innermost periphery of the inductor wiring 150, an outer peripheral surface 150c1 of the outermost periphery of the inductor wiring 150, and between the turns of the inductor wiring 150.

[0032] The innermost circumference of the inductor wiring refers to the radially inner circumference of the inductor wiring when the inductor wiring has less than one turn, and refers to the radially inner circumference of the part of the inductor wiring that forms one turn including the inner peripheral end when the inductor wiring has one or more turns. The outermost circumference of the inductor wiring refers to the radially outer circumference of the inductor wiring when the inductor wiring has less than one turn, and refers to the radially outer circumference of the part of the inductor wiring that forms one turn including the outer peripheral end when the inductor wiring has one or more turns.

[0033] The top surface portion 31 is provided on a part of the top surface 150a of the inductor wiring 150. Specifically, the top surface portion 31 is provided in a predetermined range on the top surface 150a of the inductor wiring 150 around the first escape routing 21 when viewed from the Z direction. The predetermined range is a range in which insulation between the top surface 150a of the inductor wiring and the first escape routing 21 can be ensured. In this embodiment, the shape of the predetermined range is a shape that follows the outline (rectangle) of the first escape routing 21 when viewed from the Z direction. This makes it possible to easily ensure insulation between the top surface 150a of the inductor wiring and the first escape routing 21.

[0034] Similarly, the top surface portion 31 is provided in a predetermined range on the top surface 150a of the inductor wiring 150 around the second escape routing 22 when viewed from the Z direction. The predetermined range is a range that can ensure insulation between the top surface 150a of the inductor wiring and the second escape routing 22. In this embodiment, the shape of the predetermined range is a shape that follows the outer shape (circular) of the second escape routing 22 when viewed from the Z direction. This makes it possible to easily ensure insulation between the top surface 150a of the inductor wiring and the second escape routing 22.

[0035] Of the top surface 150a of the inductor wiring 150, a portion where the top surface portion 31 of the covering insulating layer 30 is not provided is in contact with the second magnetic layer 12. With the above configuration, of the top surface 150a of the inductor wiring 150, only a portion where the top surface portion 31 of the covering insulating layer 30 is not provided is in contact with the second magnetic layer 12.

[0036] According to the inductor component 1, at least a portion of the top surface 150a of the inductor wiring 150 is in contact with either the first magnetic layer 11 or the second magnetic layer 12, and therefore the volumes of the first magnetic layer 11 and the second magnetic layer 12 can be increased compared to when the entire outer surface of the inductor wiring 150 is covered with an insulating material. As a result, the inductance value of the inductor component 1 can be improved.

[0037] In particular, in an inductor component in which the area of ​​the top surface 150a and the area of ​​the bottom surface 150b of the inductor wiring 150 are each larger than the area of ​​the innermost inner surface 150d1 of the inductor wiring 150, the above-mentioned effect of increasing the volume of the first magnetic layer 11 and the second magnetic layer 12 is greater than when only the inner surface 150d1 of the outer surface of the inductor wiring 150 is in contact with the second magnetic layer 12.

[0038] 3 , in a cross section perpendicular to the extending direction of the inductor wiring 150, the inductor wiring 150 preferably has both side surfaces 150c and 150d connecting the top surface 150a and the bottom surface 150b, and the covering insulating layer 30 preferably has a wall portion 32 provided on at least one of the both side surfaces 150c and 150d. Specifically, the covering insulating layer 30 has a first wall portion 321 provided on the first side surface 150c and a second wall portion 322 provided on the second side surface 150d. With this configuration, the inductor can suppress short circuits between the both side surfaces 150c and 150d of the wiring 150 and other conductive members.

[0039] Preferably, when the direction along the axis AX from the bottom surface 150b toward the top surface 150a of the inductor wiring 150 is defined as a first direction D1, the end surface of the wall portion 32 in the first direction D1 is located closer to the first direction D1 than the top surface 150a of the inductor wiring 150. Specifically, the first end surface 321a of the first wall portion 321 in the first direction D1 is located closer to the first direction D1 than the top surface 150a of the inductor wiring 150. The second end surface 322a of the second wall portion 322 in the first direction D1 is located closer to the first direction D1 than the top surface 150a of the inductor wiring 150. With this configuration, the inductor can more reliably suppress short circuits between the side surfaces 150c, 150d of the wiring 150 and other conductive members.

[0040] Preferably, the distance in the first direction D1 between the top surface 150a of the inductor wiring 150 and the end surface in the first direction D1 of the wall portion 32 is 5 μm or more and 20 μm or less. Specifically, the distance h1 in the first direction D1 between the top surface 150a of the inductor wiring 150 and the first end surface 321a of the first wall portion 321 is 5 μm or more and 20 μm or less. The distance h2 in the first direction D1 between the top surface 150a of the inductor wiring 150 and the second end surface 322a of the second wall portion 322 is 5 μm or more and 20 μm or less.

[0041] According to the above configuration, since the distances h1 and h2 are 5 μm or more, it is possible to prevent the inner circumferential surface 150d1 of the innermost periphery of the inductor wiring 150 from shorting via the second magnetic layer 12. Furthermore, when the inductor wiring 150 has one or more turns, as in this embodiment, it is possible to prevent shorting between adjacent turns. Since the distances h1 and h2 are 20 μm or less, the inductor wiring 150 can be formed in a desired shape. As a result, a desired inductor value can be obtained. If the distances h1 and h2 exceed 20 μm, the wall portions 32 may be inclined in the forward X direction or the reverse X direction after formation, which may prevent the inductor wiring 150 from being formed in a desired shape. Furthermore, since the distances h1 and h2 are 20 μm or less, it is possible to further increase the volume of the second magnetic layer 12.

[0042] As in this embodiment, when a plurality of wall portions 32 are present in the X direction in a cross section perpendicular to the extension direction of the inductor wiring 150, it is most preferable that the distance be 5 μm or more and 20 μm or less for all of the wall portions 32. However, this is not limited thereto, and the distance may be 5 μm or more and 20 μm or less for some of the plurality of wall portions 32 in a cross section perpendicular to the extension direction of the inductor wiring 150.

[0043] 1 and 2, the covering insulating layer 30 is preferably provided on at least a portion of the top surface 150a of the inductor wiring 150. This configuration can increase the volume of the second magnetic layer 12 while ensuring insulation between the top surface 150a and other conductive members.

[0044] Preferably, as shown in Figures 1 and 2, when the direction in the axis AX from the bottom surface 150b of the inductor wiring 150 toward the top surface 150a is defined as a first direction D1, the inductor wiring 150 further includes first and second escape wirings 21, 22 that are connected to the top surface 150a at the ends in the extension direction of the inductor wiring 150 (i.e., the inner circumferential end 151 and the outer circumferential end 152) and extend in the first direction D1 and are exposed from the outer surface of the element body 10, and the covering insulating layer 30 (i.e., the top surface portion 31) provided on a portion of the top surface 150a of the inductor wiring 150 is provided over a range of 80 μm or more from the periphery of the first and second escape wirings 21, 22 on the top surface 150a.

[0045] The above configuration can suppress the occurrence of a short circuit between the portion of the top surface 150a of the inductor wiring 150 that is in contact with the second magnetic layer 12 and the first and second escape wirings 21 and 22. Specifically, if a potential difference occurs in the conductor portion of the inductor component 1 due to ESD (Electro Static Discharge) or the like, a short circuit may occur via the magnetic powder of the second magnetic layer 12. In particular, a short circuit is likely to occur between the first and second escape wirings 21 and 22 and the inductor wiring 150 that is present around the first and second escape wirings 21 and 22 because the distance between them is relatively short. The inventors have discovered that even if a portion of the top surface 150a of the inductor wiring 150 is not covered with the covering insulating layer 30 and is brought into contact with the second magnetic layer 12, by providing the top surface portion 31 of the covering insulating layer 30 over a range of 80 μm or more from the periphery of the first and second outgoing wirings 21 and 22, the risk of short circuiting can be reduced to the same extent as when the entire top surface 150a of the inductor wiring 150 is covered with the covering insulating layer 30.

[0046] (Modification) Fig. 4 is a schematic cross-sectional view showing an inductor component 1A according to a modification, which corresponds to Fig. 3 .

[0047] As shown in Figure 4, in a cross section perpendicular to the extension direction of the inductor wiring 150, the inductor wiring 150 has both side surfaces 150c and 150d connecting the top surface 150a and the bottom surface 150b, and both side surfaces 150c and 150d of the inductor wiring located at the innermost periphery include an inner peripheral surface 150d1 of the innermost periphery and an outer peripheral surface 150c2 opposite to the inner peripheral surface 150d1, and the covering insulating layer 30 has at least a first wall portion 321 and a second wall portion 322 provided on each of the inner peripheral surface 150d1 and the outer peripheral surface 150c2, and the end face 322a in the first direction D1 of the second wall portion 322 provided on the inner peripheral surface 150d1 is located on the second direction D2 side, which is the opposite direction to the first direction D1, relative to the end face 321a in the first direction D1 of the first wall portion 321 provided on the outer peripheral surface 150c2.

[0048] Here, when the number of turns of the inductor wiring 150 is less than one, the above-mentioned "both side surfaces of the inductor wiring located at the innermost periphery" refers to both side surfaces of the inductor wiring 150 in a cross section perpendicular to the extension direction of the inductor wiring 150. When the number of turns of the inductor wiring 150 is one or more, the above-mentioned "both side surfaces of the inductor wiring located at the innermost periphery" refers to both side surfaces of the cross section of the inductor wiring including the innermost periphery, among the cross sections of the multiple inductor wirings that appear in a cross section perpendicular to the extension direction of the inductor wiring 150.

[0049] According to the above configuration, the magnetic flux can be prevented from being blocked by the second wall portion 322 of the covering insulating layer 30 in the portion where the magnetic flux turns around.

[0050] Preferably, as shown in FIG. 4, an end surface 322a in the first direction D1 of the second wall portion 322 provided on the inner circumferential surface 150d1 is located on the same plane as the top surface 150a of the inductor wiring 150.

[0051] According to the above configuration, the magnetic flux can be further prevented from being blocked by the second wall portion 322 of the covering insulating layer 30 in the portion where the magnetic flux turns around.

[0052] (Manufacturing Method) Next, a manufacturing method of the inductor component 1 will be described with reference to Figures 5A to 5J. Figures 5A to 5J correspond to the cross section II-II (Figure 2) of Figure 1. For convenience, the second escape wiring side is omitted from Figures 5A to 5J.

[0053] 5A, an insulating base layer 70 that does not contain a magnetic material is formed on a substrate 90. The substrate 90 is made of, for example, sintered ferrite and has a flat plate shape.

[0054] The insulating base layer 70 is made of, for example, a polyimide resin that does not contain a magnetic material. The insulating base layer 70 is formed by coating the polyimide resin on the substrate 90 by printing, painting, or the like. After the insulating base layer 70 is coated, it may be patterned using photolithography to leave only the polyimide resin in the region where the inductor wiring 150 is to be formed. Note that, before forming the insulating base layer 70, an insulating material that will serve as a grinding protection layer may be formed on the substrate 90.

[0055] 5B, a seed layer 81 is formed on the underlying insulating layer 70. Specifically, a material for the seed layer 81 (e.g., a titanium / copper alloy) is deposited on the upper surface of the underlying insulating layer 70 by sputtering, and then patterned by photolithography to form the seed layer 81.

[0056] As shown in FIG. 5C , wall portions 32 that will become part of the covering insulating layer are formed on the underlying insulating layer 70. The wall portions 32 are formed, for example, from a photosensitive permanent photoresist. A photosensitive permanent photoresist is a photoresist that is not removed after processing. Specifically, the photosensitive permanent photoresist is laminated on the underlying insulating layer 70, exposed to light, and developed. As a result, the material in the unexposed portions is removed, forming the wall portions 32.

[0057] 5D, electrolytic plating is performed while supplying power to the seed layer 81. As a result, an inductor wiring 150 is formed between the wall portions 32.

[0058] As shown in FIG. 5E , the top surface portion 31 of the covering insulating layer 30 is formed on a portion of the top surface 150a of the inductor wiring 150. Specifically, a dry film resist (DFR) is laminated on the top surface 150a of the inductor wiring 150, exposed to light, and developed. As a result, the material in the unexposed portion is removed to form the top surface portion 31. At this time, the dry film resist located in the portion where the top surface 150a of the inductor wiring 150 and the second magnetic layer 12 contact each other is removed. As a result, when the second magnetic layer 12 is pressure-bonded in a subsequent process, a portion of the top surface 150a of the inductor wiring 150 will contact the second magnetic layer.

[0059] 5F , a seed layer 82 is formed by sputtering so as to cover the exposed portion of the top surface 150 a of the inductor wiring 150 and the top surface portion 31 and wall portion 32 of the covering insulating layer 30. At this time, since the distance between the end face of the wall portion 32 of the covering insulating layer 30 and the top surface 150 a of the inductor wiring 150 is 20 μm or less, the sputtered film can be adhered well even to the step portion between the upper end face of the wall portion 32 and the top surface 150 a, and the seed layer 82 can be formed well.

[0060] As shown in FIG. 5G , a first via wiring 212 and a first columnar wiring 211 are formed on the outer peripheral end 152 of the inductor wiring 150. Specifically, a resist film 320 is formed on the seed layer 82, and an opening is provided in the resist film 320 at a position corresponding to the first via wiring 212. At this time, the distance between the end surface of the wall portion 32 of the covering insulating layer 30 and the top surface 150 a of the inductor wiring 150 is 20 μm or less, so that the resist film 320 can be formed into a desired shape. This allows the first via wiring 212 and the first columnar wiring 211 to also be formed into the desired shapes. Thereafter, electrolytic plating is performed while supplying power to the seed layer 82, and a plating layer is formed in the opening. This forms the first via wiring 212 and the first columnar wiring 211 in the opening.

[0061] 5H , the resist film 320 is peeled off, the exposed seed layer 82 is removed, and the second magnetic layer 12 is pressure-bonded from above the substrate 90 toward the inductor wiring 150. As a result, the inductor wiring 150, the base insulating layer 70, the covering insulating layer 30, and the first columnar wiring 211 are covered with the second magnetic layer 12.

[0062] As shown in FIG. 5I, the top surface of the second magnetic layer 12 is ground to expose the top surface of the first columnar wiring 211 .

[0063] As shown in FIG. 5J , a coating film 60 is formed on the upper surface of the second magnetic layer 12. The coating film 60 is formed of, for example, solder resist. The substrate 90 is then ground to expose the lower surface of the base insulating layer 70. The first magnetic layer 11 is then pressure-bonded from below the base insulating layer 70 toward the inductor wiring 150. This covers the lower surface of the base insulating layer 70 with the first magnetic layer 11. The lower surface of the first magnetic layer 11 is then ground to adjust the thickness of the first magnetic layer 11. Next, a first external terminal 51 is formed so as to cover the upper surface of the first columnar wiring 211. The first external terminal 51 has a three-layer structure of Cu / Ni / Au formed by, for example, electroless plating. The substrate is then singulated using a dicer or the like to manufacture the inductor component 1.

[0064] Second Embodiment Fig. 6 is a schematic cross-sectional view showing a second embodiment of an inductor component. Fig. 6 corresponds to the cross-sectional view taken along line II-II in Fig. 1. For convenience, the second escape wiring side is omitted from Fig. 6. The second embodiment differs from the first embodiment in that the top surface of the covering insulating layer and the underlying insulating layer are not provided. This difference in configuration will be described below. The other components are the same as those in the first embodiment, and the same reference numerals as those in the first embodiment are used, and their description will be omitted.

[0065] 6 , the covering insulating layer 30B has only wall portions 32 and does not have a top surface portion. As a result, the entire top surface 150a of the inductor wiring 150 is in contact with the second magnetic layer 12. The first escape wiring 21B does not have a via wiring, and the first columnar wiring 211 is directly connected to the inductor wiring 150. With this configuration, the volume of the second magnetic layer 12 can be further increased, and the inductance value of the inductor component 1B can be further improved.

[0066] In the inductor component 1B, no underlying insulating layer is provided, and the upper surface of the first magnetic layer 11 and the lower surface of the second magnetic layer 12 are in contact with each other. As a result, the entire bottom surface 150b of the inductor wiring 150 is in contact with the first magnetic layer 11. With this configuration, the thickness of the first magnetic layer 11 in the Z direction can be increased compared to when an underlying insulating layer is provided, and therefore the volume of the first magnetic layer 11 can be further increased, thereby further improving the inductance value of the inductor component 1B.

[0067] The inductor component 1B can be manufactured, for example, by not providing the top surface portion 31 in the process shown in FIG. 5E, and by removing the base insulating layer 70 after grinding the substrate 90 in the process shown in FIG. 5J.

[0068] <Third Embodiment> Fig. 7 is a schematic cross-sectional view showing a third embodiment of an inductor component. Fig. 7 corresponds to Fig. 3. The third embodiment differs from the first embodiment in that a wall portion of the insulating coating layer is not provided on the inner peripheral surface of the innermost periphery of the inductor wiring. This different configuration will be described below. The other configurations are the same as those of the first embodiment, and the same reference numerals as those of the first embodiment will be used, and description thereof will be omitted.

[0069] 7 , at least a portion of the inner circumferential surface 150d1 of the innermost periphery of the inductor wiring 150 is in contact with the second magnetic layer 12. In this embodiment, the entire inner circumferential surface 150d1 of the innermost periphery of the inductor wiring 150 is in contact with the second magnetic layer 12. With this configuration, the volume of the second magnetic layer 12 can be further increased, and therefore the inductance value of the inductor component 1C can be further improved.

[0070] The inductor component 1C can be manufactured, for example, by not providing the wall portion 32 corresponding to the position of the inner circumferential surface of the innermost periphery of the inductor wiring in the process shown in FIG. 5C.

[0071] <Fourth embodiment> Fig. 8 is a schematic plan view showing a fourth embodiment of an inductor component. Fig. 8 corresponds to Fig. 1. The fourth embodiment differs from the first embodiment mainly in the position where the top surface portion of the covering insulating layer is provided. This different configuration will be described below. The other configurations are the same as those of the first embodiment, and the same reference numerals as those of the first embodiment are used, and their description will be omitted. Note that in Fig. 8, for convenience, the position where the top surface portion of the covering insulating layer is located is shaded.

[0072] As shown in Figure 8, when the direction along the axis AX from the bottom surface of the inductor wiring 150 toward the top surface is defined as a first direction, the inductor wiring 150 further includes first and second escape wirings 21, 22 that are connected to the top surface at the ends in the extension direction of the inductor wiring 150 (i.e., the inner circumferential end 151 and the outer circumferential end 152), extend in the first direction, and are exposed from the outer surface of the base body 10, and a covering insulating layer 30 (i.e., the top surface portion 31) provided on a portion of the top surface of the inductor wiring 150 is separated from the first and second escape wirings 21, 22.

[0073] Specifically, the top surface portion 31 of the covering insulating layer 30 is provided on the entire top surface of the inductor wiring 150, excluding the regions surrounding the first and second escape wirings 21 and 22. The top surface portion 31 of the covering insulating layer 30 may be provided on a part of the top surface excluding the regions surrounding the first and second escape wirings 21 and 22, as long as it is separated from the first and second escape wirings 21 and 22. In this embodiment, the top surface portion 31 of the covering insulating layer 30 is not provided in the regions surrounding the first and second escape wirings 21 and 22. Therefore, unlike the first embodiment, the first and second escape wirings 21 and 22 do not have first and second via wirings 212 and 222. That is, the bottom surfaces of the first and second columnar wirings 211 and 221 of the first and second escape wirings 21 and 22 are in direct contact with the top surface of the inductor wiring 150.

[0074] According to the above configuration, the top surface portion 31 can be provided at a desired location between the inductor wirings 150 where a short circuit is likely to occur. Furthermore, since the first and second escape wirings 21, 22 do not have the first and second via wirings 212, 222 as shown in FIG. 1, the contact area between the first and second escape wirings 21, 22 (i.e., the first and second columnar wirings 211, 221) and the inductor wiring 150 can be increased, the adhesion strength between the first and second escape wirings 21, 22 and the inductor wiring 150 is increased, and defects such as breakage due to external stress can be suppressed.

[0075] The present disclosure is not limited to the above-described embodiments, and design modifications are possible within the scope of the present disclosure. For example, the respective features of the first to fourth embodiments may be combined in various ways.

[0076] In the above embodiment, first and second lead-out wirings, first and second external terminals, and a coating film were provided, but these components are not essential and may not be provided or may be replaced with other components.

[0077] In the above embodiment, the inductor wiring is one layer, but it may be two or more layers. In this case, the "top surface of the inductor wiring" refers to the top surface of the inductor wiring in the top layer, and the "bottom surface of the inductor wiring" refers to the bottom surface of the inductor wiring in the bottom layer.

[0078] In the above embodiment, at least a portion of the top surface of the inductor wiring is in contact with the second magnetic layer, but the entire top surface of the inductor wiring may be covered with an insulating covering layer, and at least a portion of the bottom surface of the inductor wiring may be in contact with the first magnetic layer. In this case, the top surface of the inductor wiring corresponds to an example of the "second surface" set forth in the claims, and the bottom surface of the inductor wiring corresponds to an example of the "first surface" set forth in the claims.

[0079] In the above embodiment, the wall portion of the insulating covering layer is present in the entire region between adjacent turns of the inductor wiring, but the second magnetic layer may be present between adjacent turns. Specifically, in a cross section perpendicular to the extending direction of the inductor wiring, the wall portion of the insulating covering layer may be provided on at least one of both side surfaces of the inductor wiring, and the second magnetic layer may be present between adjacent turns.

[0080] (Example) Chips were fabricated in which the distance h between the top surface of the inductor wiring and the end face in the first direction of the wall portion of the insulating coating layer was varied to 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, and 10 μm, and a humidity load test was performed on each chip. In the humidity load test, a current was passed through the chip in a high-temperature, high-humidity environment, and the insulation resistance of the inductor wiring was measured after a predetermined time. The humidity load test conditions were 85°C, 85% RH, 1 A, and 500 hours. Of the 15 chips, the number of chips with normal insulation resistance (number of good chips) was investigated. The test results are shown in Table 1.

[0081]

[0082] Chips were fabricated with the distance h between the top surface of the inductor wiring and the end face in the first direction of the wall portion of the insulating coating layer varied to 10 μm, 15 μm, 20 μm, 25 μm, and 30 μm, and the occurrence of defects in the manufacturing process was investigated. Specifically, for samples in which a seed layer was formed by sputtering after the wall portion of the insulating coating layer was formed, the film formation state of the seed layer was observed using an optical microscope. Furthermore, for samples in which a resist film was formed after the seed layer was formed, the film formation state of the resist film was observed using an optical microscope. Then, of the 15 chips, the number of chips in which the seed layer and resist film were in a normal state (number of good chips) was investigated. The investigation results are shown in Table 2.

[0083]

[0084] As shown in Table 1, when the distance h was 4 μm or less, there were chips with abnormal insulation resistance. As shown in Table 2, when the distance h was 25 μm or more, there were chips with defects in the manufacturing process.

[0085] The present disclosure includes the following aspects. <1> An inductor component comprising: an element body including a magnetic layer; a coil disposed within the element body and having an axis; and an insulating layer covering a portion of an outer surface of the coil, wherein the coil has inductor wiring wound along a plane perpendicular to the axis, the inductor wiring having a first surface and a second surface opposing each other in the axial direction, and at least a portion of the first surface of the inductor wiring is in contact with the magnetic layer. <2> The inductor component according to <1>, wherein the entire surface of the first surface of the inductor wiring is in contact with the magnetic layer. <3> The inductor component according to <1> or <2>, wherein the entire surface of the second surface of the inductor wiring is in contact with the magnetic layer. <4> The inductor component according to any one of <1> to <3>, wherein, in a cross section perpendicular to the extension direction of the inductor wiring, the inductor wiring has both side surfaces connecting the first surface and the second surface, and the insulating layer has a wall portion provided on at least one of the both side surfaces. <5> The inductor component according to <4>, wherein, when a direction in the axial direction from the second surface toward the first surface of the inductor wiring is defined as a first direction, an end face of the wall portion in the first direction is located closer to the first direction than the position of the first surface of the inductor wiring. <6> The inductor component according to <5>, wherein a distance in the first direction between the first surface of the inductor wiring and the end face of the wall portion in the first direction is 5 μm or more and 20 μm or less. <7> The inductor component according to any one of <1> to <6>, wherein at least a part of an inner circumferential surface of an innermost periphery of the inductor wiring is in contact with the magnetic layer.<8> The inductor component according to any one of <1> to <6>, wherein, in a cross section orthogonal to an extension direction of the inductor wiring, the inductor wiring has both side surfaces connecting the first surface and the second surface, the both side surfaces of the inductor wiring located at the innermost periphery include an inner circumferential surface of the innermost periphery and an outer circumferential surface facing the inner circumferential surface, the insulating layer has wall portions provided at least on each of the inner circumferential surface and the outer circumferential surface, and when a direction in the axial direction from the second surface toward the first surface of the inductor wiring is defined as a first direction, an end face in the first direction of the wall portion provided on the inner circumferential surface is located closer to a second direction opposite to the first direction than an end face in the first direction of the wall portion provided on the outer circumferential surface. <9> The inductor component according to <8>, wherein the end face in the first direction of the wall portion provided on the inner circumferential surface is located on the same plane as the first surface of the inductor wiring. <10> The inductor component according to any one of <1> to <9>, wherein the insulating layer is provided on at least a part of the first surface of the inductor wiring. <11> The inductor component according to <10>, further comprising: a lead-out wiring connected to the first surface at an end of the inductor wiring in an extending direction, extending in the first direction and exposed from an outer surface of the element body, when a first direction is a direction from the second surface toward the first surface of the inductor wiring in the axial direction. <12> The inductor component according to <10>, further comprising: a lead-out wiring connected to the first surface at an end of the inductor wiring in the extending direction, extending in the first direction and exposed from an outer surface of the element body, when the axial direction is defined as a first direction from the second surface of the inductor wiring toward the first surface of the inductor wiring; and the insulating layer provided on a part of the first surface of the inductor wiring is separated from the lead-out wiring.

[0086] 1, 1A, 1B, 1C, 1D Inductor component 10 Body 10a First main surface 10b Second main surface 10c to 10f First to fourth side surfaces 11 First magnetic layer 12 Second magnetic layer 15 Coil 21, 21B First lead-out wiring 211 First columnar wiring 212 First via wiring 22 Second lead-out wiring 221 Second columnar wiring 222 Second via wiring 30, 30B Covering insulating layer 31 Top surface 32 Wall portion 321 First wall portion 321a End surface of first wall portion 322 Second wall portion 322a End surface of second wall portion 51 First external terminal 52 Second external terminal 60 Covering film 70 Underlying insulating layer 81, 82 Seed layer 150 Inductor wiring 150a Top surface (first surface) of inductor wiring 150b Bottom surface (second surface) of inductor wiring 150c First side surface of inductor wiring 150c1 Outer surface of outermost periphery of inductor wiring 150c2 Outer surface facing inner surface of innermost periphery of inductor wiring 150d Second side surface of inductor wiring 150d1 Inner surface of innermost periphery of inductor wiring 151 Inner peripheral end 152 Outer peripheral end AX Coil axis D1 First direction D2 Second direction h1, h2 Distance

Claims

1. A body including a magnetic layer, a coil disposed in the body and having an axis, and an insulating layer covering a part of the outer surface of the coil, wherein the coil has an inductor wiring wound along a plane orthogonal to the axis, the inductor wiring has a first surface and a second surface facing each other in the axial direction, at least a part of the first surface of the inductor wiring is in contact with the magnetic layer, in a cross section orthogonal to the extending direction of the inductor wiring, the inductor wiring has both side surfaces connecting the first surface and the second surface, the insulating layer has a wall portion provided on at least one of the both side surfaces, when viewed along the axial direction, the wall portion is provided at a position deviated from the inductor wiring so as not to overlap with the inductor wiring, when the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as a first direction, an end surface of the wall portion in the first direction is located on the first direction side with respect to a position of the first surface of the inductor wiring, an inductor component.

2. A body including a magnetic layer, a coil disposed in the body and having an axis, and an insulating layer covering a part of the outer surface of the coil, wherein the coil has an inductor wiring wound along a plane orthogonal to the axis, the inductor wiring has a first surface and a second surface facing each other in the axial direction, at least a part of the first surface of the inductor wiring is in contact with the magnetic layer, in a cross section orthogonal to the extending direction of the inductor wiring, the inductor wiring has both side surfaces connecting the first surface and the second surface, both side surfaces of the inductor wiring located at the innermost circumference include an inner circumferential surface of the innermost circumference and an outer circumferential surface facing the inner circumferential surface, the insulating layer has wall portions provided at least on each of the inner circumferential surface and the outer circumferential surface, when viewed along the axial direction, the wall portions are provided at positions deviated from the inductor wiring so as not to overlap with the inductor wiring, when the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as a first direction, an end surface of the wall portion provided on the inner circumferential surface in the first direction is located on the second direction side opposite to the first direction with respect to an end surface of the wall portion provided on the outer circumferential surface in the first direction, an inductor component.

3. A body including a magnetic layer, a coil disposed in the body and having an axis, An insulating layer covering a part of the outer surface of the coil, The coil has an inductor wiring wound along a plane orthogonal to the axis, The inductor wiring has a first surface and a second surface facing each other in the axial direction, At least a part of the first surface of the inductor wiring is in contact with the magnetic layer, The insulating layer is provided at least on a part of the first surface of the inductor wiring, When the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as the first direction, a lead-out wiring connected to the first surface at an end in the extending direction of the inductor wiring and extending in the first direction and exposed from the outer surface of the element body is further provided, The insulating layer provided on a part of the first surface of the inductor wiring is provided over a range of 80 μm or more from the periphery of the lead-out wiring over the entire circumference of the lead-out wiring, an inductor component.

4. The inductor component according to any one of claims 1 to 3, wherein the entire first surface of the inductor wiring is in contact with the magnetic layer.

5. The inductor component according to any one of claims 1 to 3, wherein the entire second surface of the inductor wiring is in contact with the magnetic layer.

6. In a cross-section orthogonal to the extending direction of the inductor wiring, The inductor wiring has both side surfaces connecting the first surface and the second surface, The inductor component according to claim 2 or 3, wherein the insulating layer has a wall portion provided on at least one of the both side surfaces.

7. The inductor component according to claim 1, wherein the distance in the first direction between the first surface of the inductor wiring and the end surface in the first direction of the wall portion is 5 μm or more and 20 μm or less.

8. The inductor component according to any one of claims 1 to 3, wherein at least a part of the inner peripheral surface of the innermost circumference of the inductor wiring is in contact with the magnetic layer.

9. The inductor component according to claim 2, wherein the end surface in the first direction of the wall portion provided on the inner peripheral surface is located on the same plane as the first surface of the inductor wiring.

10. The inductor component according to claim 1 or 2, wherein the insulating layer is provided at least on a part of the first surface of the inductor wiring.

11. When the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as the first direction, a lead wiring is further provided which is connected to the first surface at an end portion in the extending direction of the inductor wiring and extends in the first direction to be exposed from the outer surface of the element body. The inductor component according to claim 3, wherein the insulating layer provided on a part of the first surface of the inductor wiring is spaced apart from the lead wiring.

12. The inductor component according to claim 6, when the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as the first direction, the end surface of the wall portion in the first direction is located on the first direction side with respect to the position of the first surface of the inductor wiring.

13. In a cross-section orthogonal to the extending direction of the inductor wiring, the inductor wiring has both side surfaces connecting the first surface and the second surface. Both side surfaces of the inductor wiring located at the innermost circumference include the inner circumferential surface of the innermost circumference and the outer circumferential surface facing the inner circumferential surface. The insulating layer has wall portions provided at least on each of the inner circumferential surface and the outer circumferential surface. The inductor component according to claim 1 or 3, when the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as the first direction, the end surface of the wall portion provided on the inner circumferential surface in the first direction is located on the second direction side opposite to the first direction with respect to the end surface of the wall portion provided on the outer circumferential surface in the first direction.

14. When the direction from the second surface to the first surface of the inductor wiring in the axial direction is defined as the first direction, a lead wiring is further provided which is connected to the first surface at an end portion in the extending direction of the inductor wiring and extends in the first direction to be exposed from the outer surface of the element body. The inductor component according to claim 10, wherein the insulating layer provided on a part of the first surface of the inductor wiring is provided over a range of 80 μm or more from the periphery of the lead wiring on the first surface.