Inductor component

Abstract

The invention provides an inductor component which can further improve insulation reliability between coil wiring layers. This inductor component is provided with: an insulating body; and a coil disposed inside the body and wound along the axis, the coil including: a first coil wiring layer extending in a direction intersecting a first direction parallel to the axis; and a second coil wiring layer disposed at a distance from the first coil wiring layer in the axial direction and extending in a direction intersecting the axial direction, the first coil wiring layer and the second coil wiring layer having facing portions facing each other via an interlayer insulating portion, which is a part of the body. In a cross-section orthogonal to the extending direction of the first coil wiring layer in the facing portion, a first upper surface of the first coil wiring layer on the interlayer insulating portion side is formed of a concave curved surface that is oriented in the direction opposite the second coil wiring layer in the axial direction from both edge portions of the first upper surface.

Description

Technical Field

[0001] The present invention relates to inductor components. Background Art

[0002] Conventionally, as an inductor component, there is a structure described in Patent Document 1, for example. The inductor component described in Patent Document 1 includes a coil arranged in an insulating body. The coil is composed of, for example, a plurality of coil wiring layers stacked via an insulating layer. These coil wiring layers are electrically connected via a through-hole conductor provided in the insulating layer.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-194976

[0004] The inductor component of Patent Document 1 has room for improvement from the viewpoint of further improving the insulation reliability between two coil wiring layers stacked in the body. Summary of the invention

[0005] Therefore, an object of the present invention is to provide an inductor component in which the insulation reliability between two stacked coil wiring layers is further improved in order to solve the above-mentioned problems.

[0006] An inductor component of one technical solution of the present invention comprises: an insulating blank; and a coil, arranged inside the blank and wound along an axis, the coil comprising: a first coil wiring layer, extending in a direction intersecting with a first direction parallel to the axis; and a second coil wiring layer, arranged at a distance from the first coil wiring layer in the first direction and extending in a direction intersecting with the first direction, the first coil wiring layer and the second coil wiring layer having opposing portions opposed to each other via an interlayer insulating portion, which is a part of the blank, and in a cross section of the opposing portion that is orthogonal to the extension direction of the first coil wiring layer, a first upper surface of the first coil wiring layer located on the interlayer insulating portion side is formed by concave surfaces extending from two edges of the first upper surface in the first direction toward a direction opposite to the second coil wiring layer.

[0007] According to the inductor component of the present invention, the insulation reliability between the two stacked coil wiring layers can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A It is a schematic perspective view of an inductor component according to an embodiment of the present invention.

[0009] Figure 1B yes Figure 1A Schematic exploded perspective view of the inductor components.

[0010] Figure 2 is with Figure 1A A schematic cross-sectional view orthogonal to the axial direction of an inductor component.

[0011] Figure 3 yes Figure 2 A schematic cross-sectional view taken along line III-III is shown.

[0012] Figure 4 yes Figure 3 A schematic enlarged cross-sectional view of the juxtaposition portion shown.

[0013] Figure 5A is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0014] Figure 5B is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0015] Figure 5C is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0016] Figure 5D is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0017] Fig. 6A Yes means Figure 1A A schematic cross-sectional view of another example of a method for manufacturing an inductor component.

[0018] Figure 6B Yes means Figure 1A A schematic cross-sectional view of another example of a method for manufacturing an inductor component.

[0019] Fig. 7A is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0020] Figure 7B is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0021] Figure 7C is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0022] Fig.7D is an example Figure 1A Schematic process cross-sectional view of a method for manufacturing an inductor component.

[0023] Fig. 7E is an example Figure 1ASchematic process cross-sectional view of a method for manufacturing an inductor component.

[0024] Figure 8 This is a diagram showing an electron microscope image of a parallel portion of an inductor component according to an example.

[0025] Fig. 9 It is a figure which shows the electron microscope image of the connection part of the inductor component of Example.

[0026] Fig.10 It is a schematic cross-sectional view of a parallel portion and a connecting portion in an inductor component of a reference example.

[0027] Fig.11 It is a figure which shows the electron microscope image of the parallel-installed part of the inductor component of a reference example.

[0028] Fig.12 It is a figure which shows the electron microscope image of the connection part of the inductor component of a reference example.

[0029] Description of Reference Numerals

[0030] 1…inductor component; 10…body; 11…insulating layer; 11b…first insulating layer; 11c…intermediate insulating layer; 11d…second insulating layer; 15…first end surface; 16…second end surface; 17…bottom surface; 18…top surface; 20…coil; 21…first coil wiring layer; 22…second coil wiring layer; 23 to 25…coil wiring layer; 21a…first upper surface; 21b…first lower surface; 21c…first side surface; 22a …second upper surface; 22b…second lower surface; 22c…second side surface; 26…connecting conductor; 30…first external electrode; 40…second external electrode; 101…parallel portion; 102…connecting portion; 110…interlayer insulating portion; 111b~111d…hole; A…stacking direction; AX…axis; L…axial direction; p1, p2…edge; s1…first interface; s2…second interface; v…imaginary line; w1~w4…wiring width. DETAILED DESCRIPTION

[0031] Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the embodiment. In addition, substantially the same components are marked with the same reference numerals in the accompanying drawings. For the purpose of illustration, the dimensions of the elements in the accompanying drawings are sometimes exaggerated and may not be in scale.

[0032] In addition, for convenience of description, the terms “upper”, “lower”, “right”, “left”, and “side” indicating directions are used assuming a state in normal use, but are not intended to limit the state of use of the inductor component of the present disclosure.

[0033] Implementation Method

[0034] (Overview of Inductor Components)

[0035] Figure 1A It is a perspective view showing an embodiment of an inductor component. Figure 1B yes Figure 1A Exploded perspective view of the inductor components.

[0036] like Figure 1A as well as Figure 1B As shown, the inductor component 1 includes an insulating body 10, a coil 20 provided inside the body 10, and a first external electrode 30 and a second external electrode 40 electrically connected to the coil 20. The inductor component 1 is electrically connected to wiring of a circuit board (not shown) via the first external electrode 30 and the second external electrode 40. Figure 1A In FIG. 1 , the blank 10 is depicted transparently so that the structure can be easily understood.

[0037] like Figure 1A The blank 10 has a first end surface 15 , a second end surface 16 opposite to the first end surface 15 , a bottom surface 17 connected between the first end surface 15 and the second end surface 16 , and a top surface 18 opposite to the bottom surface 17 .

[0038] The base body 10 has a structure in which a plurality of insulating layers 11 are stacked in the thickness direction of each insulating layer 11, that is, in the stacking direction A. In this example, Figure 1A The first end face 15, the second end face 16, the bottom face 17, and the top face 18 of the green body 10 shown are parallel to the stacking direction A. The bottom face 17 side serves as a mounting surface of the inductor component 1 on a circuit board or the like. In this specification, the term "parallel" only requires being substantially parallel, and also includes being approximately parallel in consideration of a realistic range of deviation.

[0039] The insulating layer 11 contains, for example, a glass component and a filler component. The insulating layer 11 may be formed using a photosensitive insulating paste. Thus, the insulating layer 11 can be patterned by photolithography. In addition, due to firing or the like, interfaces between the plurality of insulating layers 11 may be unclear.

[0040] The first external electrode 30 and the second external electrode 40 include a conductive material such as Ag or Cu. The first external electrode 30 and the second external electrode 40 may also be composed of a conductive material and glass particles. In the example shown in the figure, the first external electrode 30 is an L-shaped electrode that extends from a portion of the first end surface 15 across a portion of the bottom surface 17. The second external electrode 40 is an L-shaped electrode that extends from a portion of the second end surface 16 across a portion of the bottom surface 17.

[0041] The coil 20 includes a conductive material. The coil 20 may be made of the same material as the first external electrode 30 and the second external electrode 40, for example. The coil 20 is wound in a spiral along the axis AX. When the coil 20 is observed from the axial direction L, it is formed, for example, in a roughly oblong shape. "Axial direction L" refers to a direction parallel to the axis (central axis of the spiral) AX around which the coil 20 is wound. The axial direction L is sometimes referred to as the "first direction". In this example, the axial direction L of the coil 20 refers to the same direction as the stacking direction A of the insulating layer 11. In addition, the shape of the coil 20 observed from the axial direction L is not limited to an oblong shape, and may also be a circle, an ellipse, a rectangle, other polygons, and the like.

[0042] One end of the coil 20 is connected to the first external electrode 30, and the other end of the coil 20 is connected to the second external electrode 40. In the example shown in the figure, the coil 20 is formed integrally with the first external electrode 30 and the second external electrode 40, and there is no clear boundary. In addition, the coil and the external electrode may be formed of different materials and different methods.

[0043] The coil 20 has a plurality of coil wiring layers 21 to 25 arranged at a distance in the axial direction L. A connection conductor 26 is arranged between two adjacent coil wiring layers. In the present embodiment, the plurality of coil wiring layers 21 to 25 and the plurality of connection conductors 26 are arranged (buried) inside a corresponding one of the insulating layers 11 .

[0044] The coil wiring layers 21 to 25 extend in directions that intersect (here, are orthogonal) the axial direction (the first direction parallel to the axis AX) L, respectively. In this specification, "orthogonal" only needs to be substantially orthogonal, and also includes the case where it is approximately orthogonal to the axial direction L in consideration of the range of actual deviations. In the illustrated example, the number of windings of each coil wiring layer 21 to 25 is less than 1 turn. In this embodiment, at least a portion of one of the two coil wiring layers adjacent to each other in the axial direction L (for example, the coil wiring layer 21) is opposed to the other coil wiring layer (for example, the coil wiring layer 22) via a portion of the blank 10, namely, the interlayer insulation portion. Figure 1A as well as Figure 1B In the example shown, two adjacent coil wiring layers include portions that are opposed to each other via an interlayer insulating portion and extend in the same direction. In this specification, the portion of two adjacent coil wiring layers in the axial direction L that is opposed via an interlayer insulating portion is referred to as an "opposed portion". The portion of the opposed portion where the two coil wiring layers are opposed to each other via an interlayer insulating portion and extend in the same direction (arranged side by side) is referred to as a "parallel portion".

[0045] The connection conductors 26 are respectively configured to electrically connect in series a portion of one coil wiring layer and a portion of the other coil wiring layer in two coil wiring layers adjacent in the axial direction L. In this specification, a portion where two coil wiring layers adjacent in the axial direction L are electrically connected to each other via a connection conductor is referred to as a "connection portion".

[0046] Thus, the plurality of coil wiring layers 21 to 25 are electrically connected in series via corresponding connection conductors 26, and form, for example, a spiral coil 20. The bottom coil wiring layer 21 is connected to the first external electrode 30. The top coil wiring layer 25 is connected to the second external electrode 40.

[0047] The following describes a more detailed structure of the opposing portion (parallel portion) and the connecting portion, taking two coil wiring layers 21 and 22 adjacent in the axial direction L as an example. In the following description, the layer located on the lower side in the stacking direction A of the two adjacent coil wiring layers (here, the coil wiring layer 21) is referred to as the "first coil wiring layer", and the layer located on the first coil wiring layer (here, the coil wiring layer 22) is referred to as the "second coil wiring layer".

[0048] (Joint Department)

[0049] Figure 2 yes Figure 1A The schematic cross-sectional view of the inductor component 1 shown in the figure, which is perpendicular to the axial direction L, shows a cross section including the upper surface of the second coil wiring layer. Figure 3 yes Figure 2 The schematic enlarged cross-sectional view taken along line III-III shows a parallel portion and a connection portion in the inductor component 1 . Figure 4 It only means Figure 3 An enlarged cross-sectional view of the parallel arrangement portion shown. Figure 3 as well as Figure 4 A cross section perpendicular to the extending direction of the first and second coil wiring layers is shown. Figure 3 as well as Figure 4 The X direction shown is a direction orthogonal to the extending direction of the first and second coil wiring layers and the axial direction L.

[0050] exist Figure 3 as well as Figure 4 In the figure, only four insulating layers 11a to 11d of the plurality of insulating layers 11 constituting the blank 10 are shown. The insulating layers 11a to 11d are stacked in sequence along the stacking direction A (here, the axial direction L). In the example shown in the figure, for convenience, the thicknesses of the insulating layers 11a to 11d are made substantially the same, but the thicknesses of the insulating layers 11a to 11d can be appropriately set. For example, the insulating layer 11d can also be thicker than the insulating layer 11b.

[0051] The parallel portion 101 includes a first coil wiring layer 21 , a second coil wiring layer 22 , and an interlayer insulating portion 110 located between the coil wiring layers 21 and 22 .

[0052] like Figure 4 As shown, the first coil wiring layer 21 is arranged inside the insulating layer (hereinafter, "first insulating layer") 11b. Here, the first coil wiring layer 21 is arranged in the first hole 111b formed in the first insulating layer 11b. The first hole 111b is, for example, a through hole that penetrates the first insulating layer 11b in the axial direction L. In addition, the first hole 111b can also be a bottomed hole (groove).

[0053] The second coil wiring layer 22 is arranged inside the insulating layer (hereinafter, "second insulating layer") 11d. Here, the second coil wiring layer 22 is arranged in the second hole 111d formed in the second insulating layer 11d. The second hole 111d is a through hole that penetrates the second insulating layer 11d in the axial direction L, for example.

[0054] The interlayer insulating portion 110 is, for example, a part of an insulating layer (hereinafter, referred to as an "intermediate insulating layer") 11c. In addition, the interlayer insulating portion 110 may include other interposed layers.

[0055] The first coil wiring layer 21 and the second coil wiring layer 22 each have, for example, a substantially rectangular (e.g., inverted trapezoidal) cross-sectional shape. The first coil wiring layer 21 has: a first upper surface 21a located on the upper side (the second coil wiring layer 22 side) in the axial direction L, a first lower surface 21b located on the lower side (the side opposite to the first upper surface 21a) in the axial direction L, and a first side surface 21c connecting the first upper surface 21a and the first lower surface 21b. Similarly, the second coil wiring layer 22 has: a second upper surface 22a located on the upper side (the side opposite to the first coil wiring layer 21) in the axial direction L, a second lower surface 22b located on the lower side (the first coil wiring layer 21 side) in the axial direction L, and a second side surface 22c connecting the second upper surface 22a and the second lower surface 22b.

[0056] The first upper surface 21a of the first coil wiring layer 21 and the second lower surface 22b of the second coil wiring layer 22 face each other with the intermediate insulating layer 11c (interlayer insulating portion 110) interposed therebetween. Figure 4 In the illustrated example, at least a portion of the first upper surface 21 a and at least a portion of the second lower surface 22 b are in contact with the intermediate insulating layer 11 c (interlayer insulating portion 110 ).

[0057] In this embodiment, Figure 4In the cross section shown, the first upper surface 21a of the first coil wiring layer 21 is formed of a concave curved surface directed downward in the axial direction L (in the opposite direction to the second coil wiring layer 22) from both edges p1 and p2 of the first upper surface 21a.

[0058] In addition, the first upper surface 21a of the first coil wiring layer 21 is located below the upper surface of the first insulating layer 11b in the axial direction L. That is, the entire first upper surface 21a of the first coil wiring layer 21 is located inside the first hole 111b of the first insulating layer 11b. Figure 4 In the cross section shown, the "upper surface of the first insulating layer 11b" is, for example, the first interface s1 between the first insulating layer 11b and the intermediate insulating layer 11c. When the first interface s1 is not easily visually confirmed due to firing or the like, as described later, the first surface 261a ( Figure 3 ) is regarded as the “height of the first interface s1”.

[0059] The first upper surface 21a of the first coil wiring layer 21 is located below the upper surface of the first insulating layer 11b in the axial direction L, thereby making it easy to ensure the thickness of the interlayer insulating portion 110 in the axial direction L. For example, the minimum thickness tm of the interlayer insulating portion 110 in the axial direction L can be made larger than the thickness T of the intermediate insulating layer 11c. Figure 4 In the example shown, the minimum thickness tm is the distance from the edge of the second lower surface 22b to the first upper surface 21a, but the position (the position in the X direction) at which the minimum thickness tm is obtained can vary depending on the shape of the second lower surface 22b. The "thickness T of the intermediate insulating layer 11c" refers to, for example, the distance along the axial direction L between the first interface s1 between the intermediate insulating layer 11c and the first insulating layer 11b and the second interface s2 between the intermediate insulating layer 11c and the second insulating layer 11d. When the interfaces s1 and s2 are unclear, for example, the distance along the axial direction L between the first surface 216a and the second surface 221a in the connecting portion 102 (see Figure 3 ) is regarded as “thickness T”.

[0060] exist Figure 4 In the example shown, at least a portion of the interlayer insulating portion 110 (intermediate insulating layer 11c) has a protruding portion protruding toward the insulating layer 11b. The first upper surface 21a of the first coil wiring layer 21 is in contact with the protruding portion of the interlayer insulating portion 110. The "protruding portion" includes, for example, a portion of the interlayer insulating portion 110 that is located within the first hole 111b of the insulating layer 11b and above the first coil wiring layer 21 (on the insulating layer 11d side). The protruding portion may also include a portion located between the above-mentioned imaginary line v and the first upper surface 21a of the first coil wiring layer 21.

[0061] On the other hand, the first lower surface 21b of the first coil wiring layer 21 is, for example, substantially flat. The first lower surface 21b may be substantially coplanar with the lower surface of the first insulating layer 11b.

[0062] The first side surface 21c of the first coil wiring layer 21 is smooth. The "smooth" surface is not limited to a flat surface, but includes a curved surface. In addition, as long as it is substantially smooth, for example, the first side surface 21c means that it does not have a protrusion protruding in a direction intersecting the axial direction L (see the following description). Figure 10 to Figure 12 ) face.

[0063] exist Figure 4 In the cross section illustrated in the example, the thickness of the central portion of the bottom of the concave surface in the first coil wiring layer 21 along the axial direction L is smaller than the thickness of the portions located on both sides of the central portion in the X direction (for example, the portion located near the first side surface 21c). As a result, the portion located on the inner diameter side of the coil where the current is easily concentrated in the first coil wiring layer 21 can be made thicker than the central portion. The "portion located on the inner diameter side of the coil" refers to, for example, a portion located near the side surface of one of the two first side surfaces 21c located in the first coil wiring layer 21, which is located on the inner side of the coil 20.

[0064] In the present embodiment, the width w2 of the first upper surface 21a of the first coil wiring layer 21 is greater than the width w1 of the first lower surface 21b. In this specification, the width of the upper surface (or lower surface) of the coil wiring layer refers to the width of the upper surface (or lower surface) in the direction (X direction) orthogonal to the axial direction L. Therefore, the shape of the cross section orthogonal to the extension direction of the first coil wiring layer 21 is roughly an inverted trapezoid.

[0065] The second coil wiring layer 22 may also have the same cross-sectional shape as the first coil wiring layer 21. In this example, the second upper surface 22a of the second coil wiring layer 22 is formed by a concave curved surface and is located below the upper surface of the second insulating layer 11d. The second lower surface 22b is, for example, substantially flat, and the second side surface 22c is substantially smooth. The width w4 of the second upper surface 22a is greater than the width w3 of the second lower surface 22b. In addition, Figure 4 In the figure, the second lower surface 22b is shown to be roughly flat, but when the upper surface of the intermediate insulating layer 11c has a curved surface reflecting the concave curved surface of the first coil wiring layer 21, the second lower surface 22b has a concave curved surface that is gentler than the concave curved surface of the first coil wiring layer 21.

[0066] In the present embodiment, in the parallel portion 101, the width w2 of the first upper surface 21a of the first coil wiring layer 21 is larger than the width w3 of the second lower surface 22b of the opposed second coil wiring layer 22. In this example, in the X direction, the second lower surface 22b of the second coil wiring layer 22 is located between the two edges p1 and p2 of the first upper surface 21a of the first coil wiring layer 21. In other words, when viewed from the axial direction L, in the parallel portion 101, the second lower surface 22b of the second coil wiring layer 22 is located on the inner side of the two edges p1 and p2 of the first upper surface 21a of the first coil wiring layer 21. By making the second lower surface 22b as a whole face opposite to the portion that is recessed (deeper) than the edges p1 and p2 of the first upper surface 21a of the first coil wiring layer 21, the distance between the first upper surface 21a and the second lower surface 22b along the axial direction L can be increased. Therefore, the interlayer insulating portion 110 can be further thickened. For example, the minimum thickness tm of the interlayer insulating portion 110 in the axial direction L (here, the distance from the edge of the second lower surface 22b to the first upper surface 21a) can be made larger than the distance tp from the edges p1 and p2 of the first upper surface 21a to the second interface s2 along the axial direction L. In addition, since the edges p1 and p2 are located below the first interface s1, the distance tp is larger than the thickness T of the intermediate insulating layer 11c (tm>tp>T).

[0067] exist Figure 4 In the example shown, the first upper surface 21a of the first coil wiring layer 21 is a concave surface, and the second lower surface 22b of the second coil wiring layer 22 is approximately flat. Therefore, the thickness of the interlayer insulation portion 110 in the axial direction L increases from the two edge portions p1, p2 sides of the second lower surface 22b of the first coil wiring layer 21 toward the central portion side. As an example, the thickness t1 of the first portion of the interlayer insulation portion 110 located between the central portion (including the lowest portion located at the bottom) of the first upper surface 21a of the first coil wiring layer 21 and the second lower surface 22b of the second coil wiring layer 22 is greater than the thickness t1 of the second portion located closer to the edge portions p1, p2 than the first portion of the interlayer insulation portion 110 in the axial direction L.

[0068] (Connection 102)

[0069] like Figure 3 As shown, the connection portion 102 includes a first coil wiring layer 21 , a second coil wiring layer 22 , and a connection conductor (via conductor layer) 26 that electrically connects the coil wiring layers 21 and 22 .

[0070] The connecting conductor 26 is arranged inside the intermediate insulating layer 11c. Here, the connecting conductor 26 is arranged in the third hole 111c that penetrates the intermediate insulating layer 11c in the thickness direction. The connecting conductor 26 can also be columnar. The lower end of the connecting conductor 26 is connected to the first upper surface 21a of the first coil wiring layer 21, and the upper end of the connecting conductor 26 is connected to the second lower surface 22b of the second coil wiring layer 22.

[0071] In this embodiment, Figure 3 In the cross section of the connecting portion 102 shown, the width of the upper edge of the first hole 111b formed in the first insulating layer 11b (width in the X direction) is greater than the width of the lower edge of the third hole 111c formed in the intermediate insulating layer 11c. In addition, the width of the upper edge of the third hole 111c is greater than the width of the lower edge of the second hole 111d formed in the second insulating layer 11d. With such a structure, when positional offset (alignment offset of the photomask) occurs during patterning of the insulating layers 11b to 11d, the connection area between the first coil wiring layer 21 and the second coil wiring layer 22 and the connecting conductor 26 can be ensured.

[0072] The maximum widths of the first hole 111b to the third hole 111c (here, the width of the upper edge) may also be substantially the same. Figure 3 In the cross section shown, the shape of the conductor formed by the first coil wiring layer 21, the connection conductor 26, and the second coil wiring layer 22 can be made close to a rectangular shape. This can suppress the line width of the coil 20 and reduce the DC resistance Rdc of the coil 20.

[0073] like Figure 3 As shown, the conductor composed of the first coil wiring layer 21, the connecting conductor 26 and the second coil wiring layer 22 may also have a step difference that reflects the inner wall of the holes 111b~111d provided in each insulating layer 11b~11d. For example, the side surface of the conductor has an upward first surface 261a at the interface between the first insulating layer 11b and the intermediate insulating layer 11c. The first surface 261a contacts the upper edge of the first hole 111b and can correspond to the upper surface of the first insulating layer 11b, that is, the first interface s1. Therefore, it is also possible to extend the imaginary line v( Figure 4 ) is regarded as the first interface s1. Similarly, the side surface of the conductor has a second surface 221a facing upward at the interface between the intermediate insulating layer 11c and the second insulating layer 11d. The second surface 221a can correspond to the upper surface of the intermediate insulating layer 11c, that is, the second interface s2. An imaginary line extending the second surface 221a in the X direction can also be regarded as the second interface s2.

[0074] exist Figure 3In the example shown, the connection conductor 26 has: a main portion located in the third hole 111c of the intermediate insulating layer 11c; and a lower portion 261 extending downward from the third hole 111c and filling the portion of the first hole 111b of the first insulating layer 11b located above the first coil wiring layer 21. The first surface 261a mentioned above is the upper surface of the lower portion 261. The lower portion 261 of the connection conductor 26 is connected to the first upper surface 21a of the first coil wiring layer 21. The first upper surface 21a of the first coil wiring layer 21 is formed by a concave surface, so that the connection area with the connection conductor 26 can be increased. Therefore, the connection resistance of the connection portion 102 can be reduced. The upper surface of the main portion of the connection conductor 26 can also be located at a position lower than the upper surface of the intermediate insulating layer 11c and formed by a concave surface. The "upper surface of the intermediate insulating layer 11c" is, for example, the second interface s2 between the intermediate insulating layer 11c and the second insulating layer 11d.

[0075] The second coil wiring layer 22 has a lower portion 221 extending downward from the second hole 111d in the connection portion 102 and located in the third hole 111c of the intermediate insulating layer 11c. The second surface 221a is the upper surface of the lower portion 221. The lower portion 221 is connected to the concave surface of the connecting conductor 26 in the third hole 111c. Thus, the connection area between the connecting conductor 26 and the second coil wiring layer 22 can be increased.

[0076] Furthermore, when the conductors composed of the first coil wiring layer 21 , the connection conductor 26 , and the second coil wiring layer 22 are integrated by firing, the interface between the layers may become unclear.

[0077] (Method for manufacturing inductor component)

[0078] Next, a method for manufacturing the inductor component 1 will be described.

[0079] Figure 5A to Figure 5D , Figure 6A to Figure 6B ,as well as Figure 7A to Figure 7D are cross-sectional views showing the steps of manufacturing the inductor component. Figure 3 The corresponding cross-sectional view shows the formation area of ​​the connection part and the parallel part. Here, the first coil wiring layer and the second coil wiring layer are used as examples for explanation, but other coil wiring layers can also be formed by the same method.

[0080] Formation of the first coil wiring layer 21

[0081] like Figure 5AAs shown, for example, a negative-type photosensitive insulating paste is used to form a first insulating material layer 1101 on the insulating material layer 1100. The first insulating material layer 1101 is formed by applying the insulating paste on the upper surface of the insulating material layer 1100. The insulating paste is applied by screen printing, for example.

[0082] The photosensitive insulating paste includes, for example, a glass material, a filler material, and a photosensitive organic component. Filler means inorganic particles that exist as particles without softening in the firing temperature domain. As fillers, various ceramic materials can be used. The filler material is, for example, quartz (crystallized quartz). In addition to quartz, the filler material may also be, for example, crystallized glass, alumina, titanium dioxide, zirconium oxide, cerium oxide, etc. The glass material is, for example, borosilicate glass. As a glass material, in addition to borosilicate glass, for example, it may also be a glass containing SiO2, B2O3, K2O, Li2O, CaO, ZnO, Bi2O3, and / or Al2O3, such as SiO2-B2O3-K2O glass, SiO2-B2O3-Li2O-CaO glass, SiO2-B2O3-Li2O-CaO-ZnO glass, and Bi2O3-B2O3-SiO2-Al2O3 glass. These inorganic components may also be combined in two or more kinds. Alternatively, a positive photosensitive insulating paste may be used.

[0083] Then, if Figure 5B As shown, a portion of the first insulating material layer 1101 is removed by a photolithography process or the like, thereby forming a first hole 111b that penetrates the first insulating material layer 1101 in the thickness direction. The first hole 111b is configured to extend in a direction orthogonal to the axial direction L. In addition, as the first hole 111b, a groove (bottomed hole) may be formed instead of a through hole.

[0084] Then, if Figure 5C As shown, the conductive layer 211 is formed by depositing a conductive material inside the first hole 111b and on the first insulating material layer 1101. As an example, the conductive layer 211 is formed by applying a conductive paste using screen printing or the like. Alternatively, the conductive layer 211 may be formed by coating using a micro dispenser, a spin coater, a slit coater, or the like.

[0085] Afterwards, if Figure 5D As shown, the coil wiring layer 21 is obtained by processing the conductive layer 211. The coil wiring layer 21 is located below the upper surface of the first insulating material layer 1101 and has an upper surface formed by a concave surface. There is no particular limitation on the processing method of the conductive layer 211, and laser processing can be used, for example.

[0086] The method for forming the first coil wiring layer 21 is not limited to Figure 5C as well as Figure 5D The method shown in Fig. 6A As shown, after the first hole 111b is formed, a conductive portion 212 having a pattern along the first hole 111b is formed. The conductive portion 212 has: a portion (hereinafter referred to as the "main portion") 212a located in the first hole 111b, and a portion (hereinafter referred to as the "cover portion") 212b extending upward from the first hole 111b. The width of the cover portion 212b is greater than the width of the first hole 111b. The peripheral edge of the cover portion 212b may also be in contact with the upper surface of the first insulating material layer 1101. The conductive portion 212 may also be formed, for example, by screen printing of a conductive paste, or by, for example, a photolithography process. Figure 5C The conductive layer 211 shown is formed by processing.

[0087] Then, if Figure 6B As shown, the conductive portion 212 is processed by laser processing, for example, to remove the entire cover portion 212b and the upper portion of the main portion 212a of the conductive portion 212. In this way, the coil wiring layer 21 having an upper surface formed of a concave curved surface is obtained.

[0088] ·Formation of the connection conductor 26

[0089] After the coil wiring layer 21 is formed, as Fig. 7A As shown, an intermediate insulating material layer 1102 is formed on the first insulating material layer 1101 and the first coil wiring layer 21. The intermediate insulating material layer 1102 is formed by the same method using the same insulating paste as the first insulating material layer 1101. Thereafter, a third hole 111c is formed in the region where the connection portion is formed in the intermediate insulating material layer 1102, for example, by a photolithography process, to expose a portion of the first coil wiring layer 21. The third hole 111c is not formed in the parallel portion.

[0090] Then, if Figure 7B As shown, a connection conductor 26 is formed in the third hole 111c. The connection conductor 26 can also be formed by the same material and method as the first coil wiring layer 21. Thus, a connection conductor 26 is obtained, which is located below the upper surface of the intermediate insulating material layer 1102 and has an upper surface formed by a concave surface.

[0091] Formation of the second coil wiring layer 22

[0092] Then, if Figure 7CAs shown in FIG. 1 , a second insulating material layer 1103 is formed on the intermediate insulating material layer 1102 and on the connecting conductor 26. The second insulating material layer 1103 is also formed by the same method using the same insulating paste as the first insulating material layer 1101. Thereafter, a second hole 111d is formed in the second insulating material layer 1103, for example, by a photolithography process, to expose a portion of the connecting conductor 26. The second hole 111d is configured to extend in a direction orthogonal to the axial direction L.

[0093] Then, if Fig.7D As shown, a second coil wiring layer 22 is formed in the second hole 111d. The second coil wiring layer 22 can also be formed by the same material and method as the first coil wiring layer 21. Thus, a second coil wiring layer 22 is obtained, which is located below the upper surface of the second insulating material layer 1103 and has an upper surface formed by a concave surface. The second coil wiring layer 22 is electrically connected to the connecting conductor 26 at the connecting portion, and in the opposing portion (here, the parallel portion), it is opposed to the first coil wiring layer 21 via the intermediate insulating material layer 1102.

[0094] In this way, the steps of forming the insulating layer and the steps of forming the coil wiring layer or the connecting conductor are repeated for a predetermined number of times. Then, the obtained laminate is fired. Fig. 7E As shown, insulating layers 11a to 11d containing glass components and filler components are formed from insulating material layers 1101 to 1103. The organic components contained in the insulating paste can be eliminated by firing. Therefore, the insulating layers 11a to 11d after firing may not contain substantially any organic components. In this way, the inductor component 1 is manufactured.

[0095] (Effect)

[0096] According to the inductor component 1 of this embodiment, Figure 4 As shown, in a cross section orthogonal to the extension direction of the first coil wiring layer 21, the first upper surface 21a of the first coil wiring layer 21 located on the interlayer insulation portion 110 side is formed by a concave curved surface from the two edges p1 and p2 of the first upper surface 21a in the axial direction L toward the direction opposite to the second coil wiring layer 22. With such a structure, it is possible to suppress the increase in the thickness of the blank 10 and increase the thickness of the interlayer insulation portion 110, thereby improving the insulation reliability between the first coil wiring layer 21 and the second coil wiring layer 22. Therefore, for example, it is possible to suppress the undesirable situation that the desired inductance cannot be obtained due to conduction between the coil wiring layers, and the yield rate is reduced.

[0097] In addition, according to the above structure, by forming the first upper surface 21a of the first coil wiring layer 21 by a concave surface, the thickness of the portion of the first coil wiring layer 21 located on the inner diameter side of the coil where the current is easily concentrated can be made larger than the thickness of the central portion of the bottom including the concave surface. As a result, the increase in the resistance of the coil 20 at high frequencies can be suppressed. In addition, the central portion of the first coil wiring layer 21 becomes thinner due to the depression of the concave surface, but the depression of the central portion where the current is not easily concentrated does not affect the resistance at high frequencies. Therefore, by forming a concave surface, the increase in the resistance of the coil 20 at high frequencies can be suppressed, and the interlayer insulation portion 110 can be thickened to improve the insulation reliability.

[0098] In addition, according to the inductor component 1, as Figure 4 As shown, the width w2 of the first upper surface 21a of the first coil wiring layer 21 is larger than the width w1 of the first lower surface 21b of the first coil wiring layer 21. According to such a structure, by expanding the width of the first upper surface 21a side forming the concave curved surface, the area of ​​the concave curved surface can be increased, and the cross-sectional area of ​​the first coil wiring layer 21 can be suppressed from being reduced. The area of ​​the concave curved surface can be increased, so it is easy to make the concave curved surface opposite to the second coil wiring layer 22. Therefore, the concave curved surface can be utilized to more reliably improve the insulation between the coil wiring layers. In addition, the wiring cross-sectional area of ​​the first coil wiring layer 21 can be suppressed from being reduced, so the thickness of the first coil wiring layer 21 will not increase, and the increase in the resistance of the first coil wiring layer 21 can be suppressed. As a result, the effect of reducing the DC resistance Rdc of the coil 20 is obtained.

[0099] Furthermore, in the inductor component 1, as Figure 4 As shown, in the portion where the first coil wiring layer 21 and the second coil wiring layer 22 are arranged side by side, the width w2 of the first upper surface 21a of the first coil wiring layer 21 is greater than the width w3 of the second lower surface 22b of the second coil wiring layer 22. With such a structure, it is easy to make the second lower surface 22b of the second coil wiring layer 22 face the deeper portion (the portion located further below) of the first upper surface 21a of the first coil wiring layer 21. Therefore, the distance between the coil wiring layers 21 and 22 can be made larger, that is, the interlayer insulating portion 110 can be made thicker.

[0100] When the parallel portion 101 is viewed from above in the axial direction L, the second lower surface 22b of the second coil wiring layer 22 may be located inside the two edges p1 and p2 of the first upper surface 21a of the first coil wiring layer 21. With such a structure, the thickness of the interlayer insulating portion 110 can be further increased.

[0101] In the inductor component 1, the base body 10 is composed of a plurality of insulating layers 11 stacked in the axial direction L. The plurality of insulating layers 11 include: a first insulating layer 11b, a second insulating layer 11d, and an intermediate insulating layer 11c located between the first insulating layer 11b and the second insulating layer 11d in the axial direction L. The first coil wiring layer 21 is arranged inside the first insulating layer 11b, and the second coil wiring layer 22 is arranged inside the second insulating layer 11d. The intermediate insulating layer 11c includes an interlayer insulating portion 110. At least a portion of the interlayer insulating portion 110 has a portion protruding toward the first insulating layer 11b. The first upper surface 21a of the first coil wiring layer 21 is in contact with the portion of the interlayer insulating portion 110 protruding toward the first insulating layer 11b. In addition, the first upper surface 21a is located in the axial direction L, lower than the upper surface (first interface s1) of the first insulating layer 11b, that is, on the side opposite to the second coil wiring layer 22 than the upper surface of the first insulating layer 11b. In this way, by positioning the first upper surface 21a of the first coil wiring layer 21 below the upper surface of the first insulating layer 11b, the distance between the first upper surface 21a of the first coil wiring layer 21 and the second lower surface 22b of the second coil wiring layer 22 can be increased. Therefore, the total thickness of the blank 10 can be suppressed, and the interlayer insulating portion 110 can be further thickened, which can further improve the insulation reliability between the coil wiring layers.

[0102] Each insulating layer 11 (including the interlayer insulating portion 110) is formed using a photosensitive material (insulating paste) containing a filler material and a glass material. The insulating layer 11 may also be a fired product of such an insulating paste. The fired insulating layer 11 may contain a glass component and a filler component. By using a photosensitive insulating paste, each insulating layer 11 can be processed using photolithography. By using photolithography, the positional offset (mask alignment offset) between the stacked multiple insulating layers 11 can be suppressed to be sufficiently small relative to the line width of each coil wiring layer.

[0103] (Examples and Reference Examples)

[0104] As an example, manufacturing Figure 1A to Figure 4 The inductor component 1 shown is a cross-sectional view of a parallel portion and a connecting portion. Figure 8 This is an electron microscope image showing an example of a cross section of the parallel portion of the inductor component 1 . Fig. 9 This is an electron microscope image showing an example of a cross section of a connection portion of the inductor component 1 .

[0105] from Figure 8 As can be seen from the cross-section of the parallel arrangement portion 101 shown in FIG. 1 , the upper surface of the first coil wiring layer 21 is formed by a concave curved surface. In addition, the side surfaces of the first coil wiring layer 21 and the second coil wiring layer 22 are substantially smooth. Fig. 9As can be seen from the cross section of the connecting portion 102 shown, the conductor formed by the first coil wiring layer 21 , the connecting conductor 26 , and the second coil wiring layer 22 has a substantially rectangular shape.

[0106] For comparison, an inductor component of a reference example was produced and similarly observed in cross section.

[0107] Fig.10 1 is a schematic cross-sectional view showing a parallel portion and a connection portion in an inductor component of a reference example. Fig.10 As shown, in the parallel portion 901 of the reference example, a coil wiring layer 92 is arranged on the coil wiring layer 91 via an interlayer insulating portion 910. The coil wiring layer 91 has: a portion (hereinafter, "main portion") 91a located in a through hole formed in the first insulating layer 11b, and a portion (hereinafter, "cover portion") 91b located above the first insulating layer 11b. The width of the cover portion 91b is larger than the width of the main portion 91a. The coil wiring layer 92 also has: a main portion 92a arranged in a through hole of the second insulating layer 11d, and a cover portion 92b located above the second insulating layer 11d. The interlayer insulating portion 910 is a part of the intermediate insulating layer 11c. In the connecting portion 902, a connecting conductor 96 connecting the coil wiring layer 91 and the coil wiring layer 92 is arranged in a hole penetrating the intermediate insulating layer 11c.

[0108] In the reference example, the intermediate insulating layer 11c is formed to cover the cover 91b of the coil wiring layer 91, so sometimes the portion of the intermediate insulating layer 11c located on the cover 91b is thinner than the other portions of the intermediate insulating layer 11c. As a result, there is a case where the thickness t of the interlayer insulating portion 910 is smaller than the thickness T of the intermediate insulating layer 11c.

[0109] Fig.11 as well as Fig.12 : is an electron microscope image showing the cross section of the parallel portion and the connection portion in the inductor component of the reference example. Fig.11 As can be seen from the cross section shown in FIG. 1 , in the reference example, the upper surface of the coil wiring layer 91 (the upper surface of the cover portion 91b) is substantially flat. Fig.11 as well as Fig.12 It can be seen that the protrusions 920 based on the cover parts 91b and 92b are formed on the side surfaces of the coil wiring layers 91 and 92. The protrusions 920 protrude in a direction perpendicular to the axial direction L.

[0110] The inductor component 1 of the embodiment can have the following advantages over the inductor component of the reference example.

[0111] Reference Fig.10As described above, in the inductor component of the reference example, due to the thin film of the intermediate insulating layer 11c, the interlayer insulating portion 910 between the coil wiring layers becomes thinner, and sometimes the desired insulation cannot be obtained. In contrast, in the inductor component 1 of the embodiment, the upper surface of the first coil wiring layer 21 is located below the upper surface of the first insulating layer 11b, and the upper surface of the coil wiring layer 21 is a concave surface, so that the interlayer insulating portion 110 with a desired thickness can be formed more reliably. For example, the thickness of the interlayer insulating portion 110 can also be made larger than the thickness T of the intermediate insulating layer 11c. Therefore, the insulation between the coil wiring layers can be improved without increasing the thickness of each insulating layer 11.

[0112] In addition, if Figure 8 as well as Fig. 9 As shown, in the inductor component 1, no protrusions are formed on the side surfaces of the coil wiring layers 21 and 22 as in the reference example (see Fig.11 , Fig.12 ), is smooth. Therefore, it is possible to suppress the reduction of the effective inner diameter of the coil caused by the protrusion. In addition, it is possible to suppress the increase in the AC resistance Rac caused by the protrusion. In the reference example, there is a situation where the cover parts 91b, 92b (protrusion 920) hinder the magnetic flux of the inner diameter part of the coil, and the Q characteristic is reduced. In contrast, according to the inductor component 1 of the embodiment, the side surfaces of the coil wiring layers 21, 22 are smooth, so it is possible to suppress the reduction of the Q characteristic caused by the protrusion.

[0113] Furthermore, in the reference example, Fig.10 As shown, it is not easy to increase the proportion of the cross-sectional area of ​​the conductor composed of the two coil wiring layers 91 and 92 in the connecting portion 902 and the connecting conductor 96 in the cross-sectional area of ​​the rectangle 90 composed of the maximum width (for example, the width of the cover 92b) and the height of the conductor. In contrast, in the embodiment, the conductor of the connecting portion 102 is roughly rectangular, which can make the above ratio higher than the reference example. Therefore, the line width can be suppressed and the wiring cross-sectional area can be increased, so the DC resistance Rdc can be reduced.

[0114] (Variation Example)

[0115] In addition, the present invention is not limited to the above-mentioned embodiment, and design changes can be made within the scope not departing from the gist of the present invention.

[0116] In the inductor component of the present invention, the first upper surface 21a of the first coil wiring layer 21 only needs to have an upper surface formed of a concave curved surface, thereby achieving an effect of improving the insulation reliability of the interlayer insulating portion 110. Figure 3In the example shown, the entire first upper surface 21a of the first coil wiring layer 21 is located below the upper surface of the first insulating layer 11b, but it is also possible that only a portion of the first upper surface 21a of the first coil wiring layer 21 is located above the upper surface of the first insulating layer 11b. Alternatively, the first coil wiring layer 21 may also have a cover portion located on the first insulating layer 11b, and the upper surface of the cover portion is formed by a concave curved surface.

[0117] The connection conductor 26 and the second coil wiring layer 22 may each have a portion located above the upper surfaces of the insulating layers 11c and 11d. The upper surfaces of the connection conductor 26 and the second coil wiring layer 22 may not be concave surfaces, but may be substantially flat, for example.

[0118] The shape, arrangement, number (number of layers) of the coil wiring layer, the connection conductor, and the insulation layer are not limited to Figure 1A as well as Figure 1B For example, in Figure 1A as well as Figure 1B In the example shown, the coil 20 is a structure formed by stacking a plurality of coil wiring layers with a winding number less than 1 turn, but the winding number of the coil wiring layer can also be more than 1 turn. That is, each coil wiring layer can also be a planar spiral shape. Figure 1A as well as Figure 1B In the embodiment, the axial direction L of the coil (the stacking direction A of the insulating layer) is parallel to the bottom surface (mounting surface) of the inductor component, but the axial direction L of the coil may also be a direction orthogonal to the bottom surface and the top surface of the inductor component. Furthermore, the shape and arrangement of the first and second external electrodes are not particularly limited.

[0119] The materials and forming methods of the components of the inductor component are not particularly limited to the above examples. For example, a coloring material such as cobalt may be added to the blank to reduce the transmittance of the product. This can reduce the visibility of the internal coil. In addition, the coil wiring layer and the connecting conductor may be made of different materials.

[0120] The above description can be expressed as follows.

[0121] The inductor component of the first technical solution comprises: an insulating blank; and a coil, which is arranged inside the above-mentioned blank and wound along an axis, and the above-mentioned coil comprises: a first coil wiring layer, which extends in a direction intersecting with a first direction parallel to the above-mentioned axis; and a second coil wiring layer, which is arranged at a distance from the above-mentioned first coil wiring layer in the above-mentioned first direction and extends in a direction intersecting with the above-mentioned first direction, and the above-mentioned first coil wiring layer and the above-mentioned second coil wiring layer have opposing portions that are opposed to each other via a part of the above-mentioned blank, namely, an interlayer insulating portion, and in a cross-section of the above-mentioned opposing portion that is orthogonal to the extension direction of the above-mentioned first coil wiring layer, the first upper surface of the above-mentioned first coil wiring layer located on the side of the above-mentioned interlayer insulating portion is formed by concave curved surfaces from the two edges of the above-mentioned first upper surface in the above-mentioned first direction toward the direction opposite to the above-mentioned second coil wiring layer.

[0122] In the inductor component of the second technical solution, according to the inductor component of the first technical solution, in a cross-section in the opposing portion that is perpendicular to the extension direction of the first coil wiring layer, a width of the first upper surface of the first coil wiring layer in a direction perpendicular to the first direction is greater than a width of the first lower surface of the first coil wiring layer located on the side opposite to the interlayer insulating portion in a direction perpendicular to the first direction.

[0123] In the inductor component of the third technical solution, according to the inductor component of the first technical solution or the second technical solution, the opposing portion includes a parallel portion in which the first coil wiring layer and the second coil wiring layer extend in the same direction via the interlayer insulating portion, and in a cross-section in the parallel portion that is perpendicular to the extension direction of the first coil wiring layer, a width of the first upper surface in a direction perpendicular to the first direction is greater than a width of the second lower surface of the second coil wiring layer located on the side of the interlayer insulating portion in a direction perpendicular to the first direction.

[0124] In the inductor component of the fourth technical solution, according to the inductor component of the third technical solution, in the cross-section in the parallel portion that is orthogonal to the extension direction of the first coil wiring layer, the thickness of the interlayer insulating portion in the first direction increases from the two edge sides of the second lower surface toward the center side.

[0125] In the inductor component of the fifth technical solution, according to the inductor component of the third technical solution or the fourth technical solution, when viewed from the first direction, in the parallel portion, the second lower surface of the second coil wiring layer is located on the inner side of the two edge portions of the first upper surface of the first coil wiring layer.

[0126] In the inductor component of the sixth technical solution, according to any one of the inductor components of the first technical solution to the fifth technical solution, in a cross-section orthogonal to the above-mentioned extension direction of the above-mentioned first coil wiring layer, the above-mentioned first coil wiring layer has: the above-mentioned first upper surface, the first lower surface of the above-mentioned first coil wiring layer located on the side opposite to the above-mentioned interlayer insulating portion, and a side surface connecting the above-mentioned first upper surface and the above-mentioned first lower surface, and the above-mentioned side surface of the above-mentioned first coil wiring layer is smooth.

[0127] In the inductor component of the seventh technical solution, according to any one of the inductor components of the first technical solution to the sixth technical solution, there is also a connecting conductor that electrically connects a portion of the above-mentioned first coil wiring layer and a portion of the above-mentioned second coil wiring layer, and the above-mentioned connecting conductor is arranged inside the hole that penetrates the above-mentioned interlayer insulating portion in the above-mentioned first direction.

[0128] In the inductor component according to an eighth aspect, according to any one of the inductor components of the first to seventh aspects, the interlayer insulating portion includes a filler material and a glass material.

[0129] In the inductor component of the ninth technical solution, according to any one of the inductor components of the first technical solution to the eighth technical solution, the above-mentioned blank is composed of a plurality of insulating layers stacked in the above-mentioned first direction, and the above-mentioned plurality of insulating layers include: a first insulating layer; a second insulating layer; and an intermediate insulating layer, which is located between the above-mentioned first insulating layer and the above-mentioned second insulating layer in the above-mentioned first direction, the above-mentioned first coil wiring layer is arranged inside the above-mentioned first insulating layer, and the above-mentioned second coil wiring layer is arranged inside the above-mentioned second insulating layer, and the above-mentioned intermediate insulating layer includes the above-mentioned interlayer insulating portion located between the above-mentioned first coil wiring layer and the above-mentioned second coil wiring layer, at least a portion of the above-mentioned interlayer insulating portion has a portion protruding toward the above-mentioned first insulating layer side, the above-mentioned first upper surface of the above-mentioned first coil wiring layer is in contact with the portion of the above-mentioned interlayer insulating portion protruding toward the above-mentioned first insulating layer side, and is located in the above-mentioned first direction at a position on the side opposite to the above-mentioned second coil wiring layer than the upper surface of the above-mentioned first insulating layer.

[0130] [Industrial Applicability]

[0131] The inductor component of the present invention has high insulation between coil wiring layers, and is therefore used, for example, as an impedance matching coil (matching coil) for high-frequency circuits, and is used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, automotive electronics, and medical / industrial machinery. The inductor component of the present invention can also be appropriately applied to tuning circuits, filter circuits, rectifier smoothing circuits, and the like.

Claims

1. An inductor component, wherein: have: Insulating body; and The coil is arranged inside the blank and wound along the axis. The coil has: a first coil wiring layer extending in a direction intersecting a first direction parallel to the axis; as well as a second coil wiring layer arranged at a distance from the first coil wiring layer in the first direction and extending in a direction intersecting the first direction, The first coil wiring layer and the second coil wiring layer have opposing portions that face each other via an interlayer insulating portion that is a part of the base body. In the cross-section orthogonal to the extension direction of the first coil wiring layer in the opposing portion, the first upper surface of the first coil wiring layer located on the interlayer insulation portion side is formed by a concave curved surface extending from the two edges of the first upper surface in the first direction toward a direction opposite to the second coil wiring layer.

2. The inductor component according to claim 1, wherein In a cross-section orthogonal to the extension direction of the first coil wiring layer in the opposing portion, a width of the first upper surface of the first coil wiring layer in a direction orthogonal to the first direction is greater than a width of the first lower surface of the first coil wiring layer located on the side opposite to the interlayer insulating portion in a direction orthogonal to the first direction.

3. The inductor component according to claim 1 or 2, wherein: The facing portion includes a parallel portion where the first coil wiring layer and the second coil wiring layer extend in the same direction via the interlayer insulating portion. In the cross-section orthogonal to the extension direction of the first coil wiring layer in the parallel portion, the width of the first upper surface in the direction orthogonal to the first direction is greater than the width of the second lower surface of the second coil wiring layer located on the interlayer insulating portion side in the direction orthogonal to the first direction.

4. The inductor component according to claim 3, wherein: In the cross section of the parallel portion perpendicular to the extending direction of the first coil wiring layer, the thickness of the interlayer insulating portion in the first direction increases from both edge portions of the second lower surface toward the center portion.

5. The inductor component according to claim 3 or 4, wherein: In the parallel portion, the second lower surface of the second coil wiring layer is located inside the both edge portions of the first upper surface of the first coil wiring layer when viewed in plan from the first direction.

6. The inductor component according to any one of claims 1 to 5, wherein: In a cross section orthogonal to the extending direction of the first coil wiring layer, The first coil wiring layer includes: the first upper surface, a first lower surface of the first coil wiring layer located on the side opposite to the interlayer insulating portion, and a side surface connecting the first upper surface and the first lower surface. The side surface of the first coil wiring layer is smooth.

7. The inductor component according to any one of claims 1 to 6, wherein: further comprising a connection conductor that electrically connects a portion of the first coil wiring layer and a portion of the second coil wiring layer, The connecting conductor is arranged inside a hole that penetrates the interlayer insulating portion in the first direction.

8. The inductor component according to any one of claims 1 to 7, wherein: The interlayer insulating portion includes a filler material and a glass material.

9. The inductor component according to any one of claims 1 to 8, wherein: The blank is composed of a plurality of insulating layers stacked in the first direction, The plurality of insulating layers comprises: a first insulating layer; a second insulating layer; as well as an intermediate insulating layer, located between the first insulating layer and the second insulating layer in the first direction, The first coil wiring layer is arranged inside the first insulating layer, The second coil wiring layer is arranged inside the second insulating layer, The intermediate insulating layer includes the interlayer insulating portion located between the first coil wiring layer and the second coil wiring layer. At least a portion of the interlayer insulating portion has a portion protruding toward the first insulating layer. The first upper surface of the first coil wiring layer contacts a portion of the interlayer insulating portion protruding toward the first insulating layer, and is located on the opposite side of the upper surface of the first insulating layer to the second coil wiring layer in the first direction.

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