Inductor component

Abstract

To provide an inductor component capable of further improving insulation reliability between coil wiring layers.SOLUTION: An inductor component comprises an element assembly of insulation property and a coil which is disposed inside of the element assembly and wound around an axis. The coil includes a first coil wiring layer extending in a direction crossing a first direction in parallel with the axis and a second coil wiring layer which is disposed while being spaced apart from the first coil wiring layer in an axial direction and extends in a direction crossing the axial direction. The first coil wiring layer and the second coil wiring layer include opposite parts which are opposed to each other via an inter-layer insulation part which is a portion of the element assembly. On a cross section orthogonal to an extension direction of the first coil wiring layer in the opposite part, a first top face positioned in the first coil wiring layer at the side of the inter-layer insulation part is formed from a concave surface turned from both edges of the first top face in an opposite direction of the second coil wiring layer in the axial direction.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an inductor component.

Background Art

[0002] Conventionally, as an inductor component, for example, there is one described in Patent Document 1. The inductor component described in Patent Document 1 includes a coil disposed in an insulating element 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 via conductors provided in the insulating layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is room for improvement in the inductor component of Patent Document 1 from the viewpoint of further enhancing the insulation reliability between two coil wiring layers stacked in the element body.

[0005] Therefore, an object of the present invention is to solve the above problems and provide an inductor component capable of further enhancing the insulation reliability between two stacked coil wiring layers.

Means for Solving the Problems

[0006] An inductor component according to one aspect of the present invention includes an insulating base body and a coil disposed inside the base body and wound along an axis. The coil includes 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 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 facing each other through an interlayer insulating portion that is part of the base body. In a cross-section orthogonal to the extending direction of the first coil wiring layer in the opposing portion, a first upper surface located on the interlayer insulating portion side of the first coil wiring layer is formed of a concave curved surface that extends in a direction opposite to the second coil wiring layer in the first direction from both edge portions of the first upper surface.

Advantages of the Invention

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

Brief Description of the Drawings

[0008]

Figure 1A

Figure 1B

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 5D

Figure 6A

Figure 6B

Figure 7A

Figure 7B

Figure 7C

Figure 7D

Figure 7E

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited by this embodiment. Also, substantially the same members in the drawings are denoted by the same reference numerals. For the purpose of illustration, the dimensions of each element in the drawings may be exaggerated and are not necessarily to scale.

[0010] In the following, for the sake of convenience of explanation, terms indicating directions such as "up", "down", "right", "left", "side", etc. are used assuming the state during normal use, but this does not mean limiting the use state of the inductor component according to the present disclosure.

[0011] 《Embodiment》 (Overview of Inductor Component) FIG. 1A is a perspective view showing an embodiment of the inductor component. FIG. 1B is an exploded perspective view of the inductor component of FIG. 1A.

[0012] As shown in FIGS. 1A and 1B, the inductor component 1 includes an insulating base body 10, a coil 20 provided inside the base 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 the wiring of a circuit board (not shown) via the first external electrode 30 and the second external electrode 40. In FIG. 1A, the base body 10 is drawn transparently so that its structure can be easily understood.

[0013] As shown in FIG. 1A, the base body 10 is formed, for example, in a substantially rectangular parallelepiped shape. The surface of the base body 10 has a first end face 15, a second end face 16 facing the first end face 15, a bottom face 17 connected between the first end face 15 and the second end face 16, and a top face 18 facing the bottom face 17.

[0014] The base body 10 has a structure in which a plurality of insulating layers 11 are stacked in the stacking direction A, which is the thickness direction of each insulating layer 11. In this example, the first end face 15, the second end face 16, the bottom face 17, and the top face 18 of the base body 10 shown in FIG. 1A are planes parallel to the stacking direction A. Also, the bottom face 17 side serves as the mounting face of the inductor component 1 on a circuit board or the like. In this specification, "parallel" only needs to be substantially parallel and includes the case of being substantially parallel considering the range of actual variations.

[0015] The insulating layer 11 contains, for example, a glass component and a filler component. The insulating layer 11 may be a layer formed using a photosensitive insulating paste. Thereby, patterning of the insulating layer 11 can be performed by photolithography. Note that the interfaces between the plurality of insulating layers 11 may not be clear due to firing or the like.

[0016] The first external electrode 30 and the second external electrode 40 contain a conductive material such as Ag or Cu. The first external electrode 30 and the second external electrode 40 may be composed of a conductive material and glass particles. In the illustrated example, the first external electrode 30 has an L shape provided across a part of the first end face 15 to a part of the bottom face 17. The second external electrode 40 has an L shape provided across a part of the second end face 16 to a part of the bottom face 17.

[0017] The coil 20 contains a conductive material. The coil 20 may be composed of, for example, the same material as the first external electrode 30 and the second external electrode 40. The coil 20 is wound spirally along the axis AX. The coil 20 is formed in a substantially oval shape, for example, when viewed from the axial direction L. The “axial direction L” is a direction parallel to the axis (central axis of the helix) AX around which the coil 20 is wound. The axial direction L may also be referred to as the “first direction”. In this example, the axial direction L of the coil 20 indicates the same direction as the stacking direction A of the insulating layers 11. Note that the shape of the coil 20 when viewed from the axial direction L is not limited to an oval shape, and may be a circular shape, an elliptical shape, a rectangular shape, or other polygons.

[0018] 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 illustrated example, the coil 20, the first external electrode 30, and the second external electrode 40 are integrally formed, and there is no clear boundary. Note that the coil and the external electrode may be formed of different materials or by different manufacturing methods.

[0019] The coil 20 has a plurality of coil wiring layers 21 to 25 arranged at a distance in the axial direction L. Between two adjacent coil wiring layers, connection conductors 26 are respectively arranged. In the present embodiment, each of the plurality of coil wiring layers 21 to 25 and the plurality of connection conductors 26 is arranged (embedded) inside a corresponding one insulating layer 11.

[0020] Each of the coil wiring layers 21 to 25 extends in a direction intersecting (here, orthogonal) to the axial direction (the first direction parallel to the axis AX) L. In this specification, "orthogonal" means that it is substantially orthogonal, and includes the case where it is substantially orthogonal to the axial direction L in consideration of the range of actual variations. In the illustrated example, the number of turns of each of the coil wiring layers 21 to 25 is less than one turn. In the present embodiment, at least a part of one of the two coil wiring layers adjacent in the axial direction L (for example, the coil wiring layer 21) faces the other coil wiring layer (for example, the coil wiring layer 22) through a layer insulation part that is a part of the base body 10. In the examples shown in FIGS. 1A and 1B, two adjacent coil wiring layers face each other through a layer insulation part and include portions extending in the same direction. In this specification, a portion where two adjacent coil wiring layers in the axial direction L face each other through a layer insulation part is called an "opposing portion". Among the opposing portions, a portion where two coil wiring layers face each other through a layer insulation part and extend in the same direction (are juxtaposed) is called a "juxtaposed portion".

[0021] Each of the connection conductors 26 is arranged to electrically connect in series a part of one of the two coil wiring layers adjacent in the axial direction L and a part of the other coil wiring layer. In this specification, a portion where two adjacent coil wiring layers in the axial direction L are electrically connected to each other through a connection conductor is called a "connection portion".

[0022] In this way, the plurality of coil wiring layers 21 to 25 are electrically connected in series to each other via one corresponding connection conductor 26, and constitute, for example, a spiral (helical) coil 20. The lowermost coil wiring layer 21 is connected to the first external electrode 30. The uppermost coil wiring layer 25 is connected to the second external electrode 40.

[0023] Hereinafter, taking two adjacent coil wiring layers 21 and 22 in the axial direction L as an example, a more detailed structure of the facing portion (juxtaposed portion) and the connection portion will be described. In the following description, the layer located on the lower side in the stacking direction A among two adjacent coil wiring layers (here, the coil wiring layer 21) is referred to as the "first coil wiring layer", and the layer located above the first coil wiring layer (here, the coil wiring layer 22) is referred to as the "second coil wiring layer".

[0024] (Juxtaposed portion) FIG. 2 is a schematic cross-sectional view orthogonal to the axial direction L in the inductor component 1 shown in FIG. 1A, showing a cross-section including the upper surface of the second coil wiring layer. FIG. 3 is a schematic enlarged cross-sectional view taken along line III-III shown in FIG. 2, showing the juxtaposed portion and the connection portion in the inductor component 1. FIG. 4 is an enlarged cross-sectional view showing only the juxtaposed portion shown in FIG. 3. FIGS. 3 and 4 show cross-sections orthogonal to the extending direction of the first and second coil wiring layers. The X direction shown in FIGS. 3 and 4 is a direction orthogonal to the extending direction of the first and second coil wiring layers and the axial direction L.

[0025] In FIGS. 3 and 4, only four insulating layers 11a to 11d among the plurality of insulating layers 11 constituting the base body 10 are shown. The insulating layers 11a to 11d are stacked in this order along the stacking direction A (here, the axial direction L). In the illustrated example, the thicknesses of the insulating layers 11a to 11d are made approximately the same for convenience, but the thicknesses of the insulating layers 11a to 11d can be set as appropriate. For example, the insulating layer 11d may be thicker than the insulating layer 11b.

[0026] The juxtaposed portion 101 has the first coil wiring layer 21, the second coil wiring layer 22, and an interlayer insulating portion 110 located between these coil wiring layers 21 and 22.

[0027] As shown in FIG. 4, the first coil wiring layer 21 is disposed inside an insulating layer (hereinafter referred to as the "first insulating layer") 11b. Here, the first coil wiring layer 21 is disposed within a 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. Note that the first hole 111b may be a blind hole (groove).

[0028] The second coil wiring layer 22 is disposed inside an insulating layer (hereinafter referred to as the "second insulating layer") 11d. Here, the second coil wiring layer 22 is disposed within a second hole 111d formed in the second insulating layer 11d. The second hole 111d is, for example, a through hole that penetrates the second insulating layer 11d in the axial direction L.

[0029] The interlayer insulating portion 110 is, for example, a part of an insulating layer (hereinafter referred to as the "intermediate insulating layer") 11c. Note that the interlayer insulating portion 110 may include other intervening layers.

[0030] Each of the first coil wiring layer 21 and the second coil wiring layer 22 has, for example, a substantially rectangular (e.g., trapezoidal in reverse) 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 (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 (opposite to the first coil wiring layer 21 side) 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.

[0031] 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. In the example shown in FIG. 4, at least a part of the first upper surface 21a and at least a part of the second lower surface 22b are in contact with the intermediate insulating layer 11c (interlayer insulating portion 110).

[0032] In this embodiment, in the cross-section shown in FIG. 4, the first upper surface 21a of the first coil wiring layer 21 is formed as a concave curved surface that extends downward (in the direction opposite to the second coil wiring layer 22) in the axial direction L from both edge portions p1 and p2 of the first upper surface 21a.

[0033] Also, 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. Note that 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 in the cross-section shown in FIG. 4. When the first interface s1 is difficult to visually recognize due to firing or the like, as will be described later, a virtual line v obtained by extending the first surface 261a (FIG. 3) in the connection portion 102 in the X direction can be regarded as the "height of the first interface s1".

[0034] Since 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, it is 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. The minimum thickness tm is, in the example shown in FIG. 4, the distance from the edge portion of the second lower surface 22b to the first upper surface 21a, but the position (the position in the X direction) where the minimum thickness tm is obtained may 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 each interface s1, s2 is not clear, for example, the distance along the axial direction L between the first surface 216a and the second surface 221a in the connection portion 102 (see FIG. 3) can be regarded as the "thickness T".

[0035] In the example shown in FIG. 4, at least a part of the interlayer insulating portion 110 (intermediate insulating layer 11c) has a protruding portion that protrudes toward the insulating layer 11b side. 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 within the first hole 111b of the insulating layer 11b and located above the first coil wiring layer 21 (on the side of the insulating layer 11d) of the interlayer insulating portion 110. The protruding portion may include a portion located between the virtual line v described above and the first upper surface 21a of the first coil wiring layer 21.

[0036] 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 flush with the lower surface of the first insulating layer 11b.

[0037] The first side surface 21c of the first coil wiring layer 21 is smooth. The "smooth" surface includes not only a flat surface but also a curved surface. Also, it only needs to be generally smooth. For example, it refers to a surface where the first side surface 21c does not have a protruding portion (see FIGS. 10 to 12 described later) protruding in a direction intersecting the axial direction L.

[0038] In the cross section illustrated in FIG. 4, the thickness along the axial direction L of the central portion including the bottom of the concave curved surface of the first coil wiring layer 21 is smaller than the thickness of the portions located on both sides of the central portion in the X direction (for example, the portions located near the first side surface 21c). Thereby, the portion of the first coil wiring layer 21 located on the coil inner diameter side where current tends to concentrate can be made thicker than the central portion. The "portion located on the coil inner diameter side" refers to, for example, the portion located near the side surface on the inner side of the coil 20 among the two first side surfaces 21c of the first coil wiring layer 21.

[0039] In the present embodiment, 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. In this specification, the width of the upper surface (or lower surface) of the coil wiring layer refers to the width in the direction (X direction) orthogonal to the axial direction L of the upper surface (or lower surface). Therefore, the shape of the cross section orthogonal to the extending direction of the first coil wiring layer 21 is generally trapezoidal in reverse.

[0040] 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 as 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 generally smooth. The width w4 of the second upper surface 22a is larger than the width w3 of the second lower surface 22b. In FIG. 4, although the second lower surface 22b is shown as being substantially flat, 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 may have a concave curved surface that is gentler than the concave curved surface of the first coil wiring layer 21.

[0041] In the present embodiment, in the juxtaposed 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 opposing 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 both edge portions p1 and p2 of the first upper surface 21a of the first coil wiring layer 21. In other words, when viewed in plan from the axial direction L, in the juxtaposed portion 101, the second lower surface 22b of the second coil wiring layer 22 is located inside both edge portions p1 and p2 of the first upper surface 21a of the first coil wiring layer 21. By opposing the entire second lower surface 22b to the portion of the first upper surface 21a of the first coil wiring layer 21 that is recessed (deeper) than the edge portions p1 and p2, the distance along the axial direction L between the first upper surface 21a and the second lower surface 22b can be increased. Therefore, the interlayer insulating portion 110 can be made thicker. 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 along the axial direction L from the edge portions p1 and p2 of the first upper surface 21a to the second interface s2. Since the edge portions 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).

[0042] In the example shown in FIG. 4, the first upper surface 21a of the first coil wiring layer 21 is a concave curved surface, and the second lower surface 22b of the second coil wiring layer 22 is substantially flat. Therefore, the thickness of the interlayer insulating portion 110 in the axial direction L increases from both edge portions p1 and p2 sides of the second lower surface 22b of the first coil wiring layer 21 toward the central portion side. As an example, among the interlayer insulating portion 110, the thickness t1 of the first portion located between the central portion (the portion including the lowermost portion located at the lowest position) 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 larger than the thickness in the axial direction L of the second portion located on the edge portions p1 and p2 sides rather than the first portion of the interlayer insulating portion 110.

[0043] (Connection portion 102) As shown in FIG. 3, the connection portion 102 includes the first coil wiring layer 21, the second coil wiring layer 22, and a connection conductor (via conductor layer) 26 that electrically connects these coil wiring layers 21 and 22.

[0044] The connection conductor 26 is disposed inside the intermediate insulating layer 11c. Here, the connection conductor 26 is disposed in a third hole 111c that penetrates the intermediate insulating layer 11c in the thickness direction. The connection conductor 26 may be columnar. The lower end portion of the connection conductor 26 is connected to the first upper surface 21a of the first coil wiring layer 21, and the upper end portion of the connection conductor 26 is connected to the second lower surface 22b of the second coil wiring layer 22.

[0045] In the present embodiment, in the cross section of the connection portion 102 shown in FIG. 3, the width of the upper edge portion (the width in the X direction) of the first hole 111b formed in the first insulating layer 11b is larger than the width of the lower edge portion of the third hole 111c formed in the intermediate insulating layer 11c. Also, the width of the upper edge portion of the third hole 111c is larger than the width of the lower edge portion of the second hole 111d formed in the second insulating layer 11d. With such a configuration, even when misalignment (alignment misalignment 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 connection conductor 26 can be ensured.

[0046] The maximum widths (here, the widths of the upper edge portions) of the first hole 111b to the third hole 111c may be substantially the same. In this case, in the cross section shown in FIG. 3, the shape of the conductor composed of the first coil wiring layer 21, the connection conductor 26, and the second coil wiring layer 22 can be made closer to a rectangle. Thereby, while suppressing the line width of the coil 20, it becomes possible to reduce the DC resistance Rdc of the coil 20.

[0047] As shown in FIG. 3, the conductor composed of the first coil wiring layer 21, the connection conductor 26, and the second coil wiring layer 22 may have steps reflecting the inner walls of the holes 111b to 111d provided in the respective insulating layers 11b to 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 is in contact with the upper edge portion of the first hole 111b and may correspond to the upper surface of the first insulating layer 11b, that is, the first interface s1. Therefore, it is also possible to regard a virtual line v (FIG. 4) obtained by extending the first surface 261a in the X direction as the first interface s1. Similarly, the side surface of the conductor has an upward second surface 221a at the interface between the intermediate insulating layer 11c and the second insulating layer 11d. The second surface 221a may correspond to the upper surface of the intermediate insulating layer 11c, that is, the second interface s2. It is also possible to regard a virtual line obtained by extending the second surface 221a in the X direction as the second interface s2.

[0048] In the example shown in FIG. 3, 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 that extends downward from the third hole 111c and fills a portion of the first hole 111b of the first insulating layer 11b that is located above the first coil wiring layer 21. The first surface 261a described 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. Since the first upper surface 21a of the first coil wiring layer 21 is formed as a concave curved surface, 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 may be located below the upper surface of the intermediate insulating layer 11c and may be formed as a concave curved 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.

[0049] In the connection portion 102, the second coil wiring layer 22 has a lower portion 221 that extends downward from the second hole 111d and is located in the third hole 111c of the intermediate insulating layer 11c. The second surface 221a described above is the upper surface of the lower portion 221. The lower portion 221 is connected to the concave curved surface of the connection conductor 26 within the third hole 111c. Thereby, the connection area between the connection conductor 26 and the second coil wiring layer 22 can be increased.

[0050] Note that when the conductor composed of the first coil wiring layer 21, the connection conductor 26, and the second coil wiring layer 22 is integrated by firing, the interfaces of the respective layers may not be clearly defined.

[0051] (Method for manufacturing an inductor component) Next, a method for manufacturing the inductor component 1 will be described.

[0052] FIGS. 5A to 5D, FIGS. 6A to 6B, and FIGS. 7A to 7D are cross-sectional process diagrams showing a method for manufacturing an inductor component, respectively. These figures are cross-sectional views corresponding to FIG. 3 and show the formation regions of the connection portion and the juxtaposed portion. Here, the first coil wiring layer and the second coil wiring layer will be described as examples, but other coil wiring layers can also be formed in the same manner.

[0053] · Formation of the first coil wiring layer 21 As shown in FIG. 5A, for example, using a negative photosensitive insulating paste, a first insulating material layer 1101 is formed on the insulating material layer 1100. The first insulating material layer 1101 is formed by applying an insulating paste on the upper surface of the insulating material layer 1100. The insulating paste is applied, for example, by screen printing.

[0054] The photosensitive insulating paste contains, for example, a glass material, a filler material, and a photosensitive organic component. The filler means inorganic particles that do not soften in the firing temperature range and exist as particles. Various ceramic materials can be used as the filler. The filler material is, for example, quartz (crystalline quartz). In addition to quartz, the filler material may be, for example, crystallized glass, alumina, titania, zirconia, ceria, etc. The glass material is, for example, borosilicate glass. In addition to borosilicate glass, the glass material may contain, for example, SiO 2 , B 2 O 3 , K 2 O, Li 2 O, CaO, ZnO, Bi 2 O 3 , and / or Al 2 O 3 and other glasses containing, for example, SiO 2 -B 2 O 3 -K 2 O-based glass, SiO 2 -B 2 O 3 -Li 2 O-CaO-based glass, SiO 2 -B 2 O 3 -Li 2 O-CaO-ZnO-based glass, and Bi 2 O 3 -B 2 O 3 -SiO 2 -Al 2 O 3It may be glass. These inorganic components may be combined in two or more kinds. Note that a positive photosensitive insulating paste may be used.

[0055] Next, as shown in FIG. 5B, a part of the first insulating material layer 1101 is removed by a photolithography process or the like to form a first hole 111b that penetrates the first insulating material layer 1101 in the thickness direction. The first hole 111b is arranged to extend in a direction orthogonal to the axial direction L. Note that, as the first hole 111b, a groove (bottomed hole) may be formed instead of a through hole.

[0056] Subsequently, as shown in FIG. 5C, a 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 by screen printing or the like. Alternatively, the conductive layer 211 may be formed by application using a microdispenser, a spin coater, a slit coater, or the like.

[0057] Thereafter, as shown in FIG. 5D, by processing the conductive layer 211, a coil wiring layer 21 is obtained that is located below the upper surface of the first insulating material layer 1101 and has an upper surface formed as a concave curved surface. The processing method of the conductive layer 211 is not particularly limited, but for example, laser processing can be used.

[0058] The method for forming the first coil wiring layer 21 is not limited to the method shown in FIGS. 5C and 5D. As shown in FIG. 6A, after forming the first hole 111b, a conductive portion 212 having a pattern along the first hole 111b may be formed. The conductive portion 212 has a portion (hereinafter referred to as the "main portion") 212a located within the first hole 111b and a portion (hereinafter referred to as the "lid portion") 212b extending upward from the first hole 111b. The width of the lid portion 212b is larger than the width of the first hole 111b. The peripheral portion of the lid portion 212b may be in contact with the upper surface of the first insulating material layer 1101. The conductive portion 212 may be formed, for example, by screen printing a conductive paste, or may be formed by processing the conductive layer 211 shown in FIG. 5C, for example, by a photolithography process or the like.

[0059] Next, as shown in FIG. 6B, by processing the conductive portion 212, for example, by laser processing, the entire lid portion 212b of the conductive portion 212 and the upper portion of the main portion 212a are removed. In this way, a coil wiring layer 21 having an upper surface formed as a concave curved surface is obtained.

[0060] · Formation of the connection conductor 26 After forming the coil wiring layer 21, as shown in FIG. 7A, an intermediate insulating material layer 1102 is formed on the first insulating material layer 1101 and on the first coil wiring layer 21. The intermediate insulating material layer 1102 is formed in the same manner using the same insulating paste as the first insulating material layer 1101. Thereafter, a third hole 111c that exposes a part of the first coil wiring layer 21 is formed, for example, by a photolithography process, in a region of the intermediate insulating material layer 1102 where the connection portion is to be formed. The third hole 111c is not formed in the juxtaposed portion.

[0061] Subsequently, as shown in FIG. 7B, a connection conductor 26 is formed in the third hole 111c. The connection conductor 26 may be formed using the same material as the first coil wiring layer 21 and in the same manner. Thereby, a connection conductor 26 that is located below the upper surface of the intermediate insulating material layer 1102 and has an upper surface formed as a concave curved surface is obtained.

[0062] · Formation of the second coil wiring layer 22 Next, as shown in FIG. 7C, a second insulating material layer 1103 is formed on the intermediate insulating material layer 1102 and the connection conductor 26. The second insulating material layer 1103 is also formed in the same manner using the same insulating paste as the first insulating material layer 1101. Thereafter, a second hole 111d that exposes a part of the connection conductor 26 is formed in the second insulating material layer 1103, for example, by a photolithography process. The second hole 111d is arranged to extend in a direction orthogonal to the axial direction L.

[0063] Subsequently, as shown in FIG. 7D, a second coil wiring layer 22 is formed in the second hole 111d. The second coil wiring layer 22 may be formed in the same manner using the same material as the first coil wiring layer 21. As a result, a second coil wiring layer 22 is obtained that is located below the upper surface of the second insulating material layer 1103 and has an upper surface formed as a concave curved surface. The second coil wiring layer 22 is electrically connected to the connection conductor 26 at the connection portion, and faces the first coil wiring layer 21 via the intermediate insulating material layer 1102 at the opposing portion (here, the juxtaposed portion).

[0064] In this way, the process of forming the insulating layer and the process of forming the coil wiring layer or the connection conductor are repeated a predetermined number of times. Thereafter, the obtained laminate is fired. As a result, as shown in FIG. 7E, insulating layers 11a to 11d containing a glass component and a filler component are formed from the insulating material layers 1101 to 1103. The organic components contained in the insulating paste may disappear by firing. Therefore, the fired insulating layers 11a to 11d may not substantially contain organic components. In this way, the inductor component 1 is manufactured.

[0065] (Effect) According to the inductor component 1 of the present embodiment, as shown in FIG. 4, in a cross section orthogonal to the extending direction of the first coil wiring layer 21, the first upper surface 21a located on the side of the interlayer insulating portion 110 of the first coil wiring layer 21 is formed of a concave curved surface that extends in the axial direction L from both edge portions p1 and p2 of the first upper surface 21a in a direction opposite to the second coil wiring layer 22. With such a configuration, it is possible to increase the thickness of the interlayer insulating portion 110 while suppressing an increase in the thickness of the element body 10, so that the insulation reliability between the first coil wiring layer 21 and the second coil wiring layer 22 can be improved. Therefore, for example, it is possible to suppress problems such as conduction between the coil wiring layers, failure to obtain a desired inductance, and a decrease in yield.

[0066] Further, according to the above configuration, since the first upper surface 21a of the first coil wiring layer 21 is formed of a concave curved surface, the thickness of the portion of the first coil wiring layer 21 located on the inner diameter side of the coil where current tends to concentrate can be made larger than the thickness of the central portion including the bottom of the concave curved surface. Thereby, an increase in the resistance of the coil 20 at high frequencies can be suppressed. Although the central portion of the first coil wiring layer 21 becomes thinner due to the recess by the concave curved surface, the recess in the central portion where current concentration hardly occurs does not significantly affect the resistance at high frequencies. Therefore, by forming the concave curved surface, it becomes possible to increase the thickness of the interlayer insulating portion 110 to improve the insulation reliability while suppressing an increase in the resistance of the coil 20 at high frequencies.

[0067] Also, according to the inductor component 1, as shown in FIG. 4, 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. With such a configuration, by widening the width on the side of the first upper surface 21a that forms the concave surface, it is possible to increase the area of the concave surface while suppressing a decrease in the cross-sectional area of the first coil wiring layer 21. Since the area of the concave surface can be increased, it becomes easier to oppose the concave surface to the second coil wiring layer 22. Therefore, the insulation between the coil wiring layers can be more reliably enhanced by utilizing the concave surface. Also, since it is possible to suppress a decrease in the wiring cross-sectional area of the first coil wiring layer 21, an increase in the resistance of the first coil wiring layer 21 can be suppressed without increasing the thickness of the first coil wiring layer 21. As a result, the effect of reducing the DC resistance Rdc of the coil 20 can be obtained.

[0068] Furthermore, in the inductor component 1, as shown in FIG. 4, in the juxtaposed portion of the first coil wiring layer 21 and the second coil wiring layer 22, 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 second coil wiring layer 22. With such a configuration, it becomes easier to oppose the second lower surface 22b of the second coil wiring layer 22 to a deeper portion (a portion located more downward) 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 insulation portion 110 can be made thicker.

[0069] In a plan view of the juxtaposed portion 101 as viewed from 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 configuration, the thickness of the interlayer insulation portion 110 can be further increased.

[0070] 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 disposed inside the first insulating layer 11b, and the second coil wiring layer 22 is disposed inside the second insulating layer 11d. The intermediate insulating layer 11c includes an interlayer insulating portion 110. At least a part of the interlayer insulating portion 110 has a portion protruding toward the first insulating layer 11b side. 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 side. The first upper surface 21a is also located below the upper surface (the first interface s1) of the first insulating layer 11b in the axial direction L, that is, on the side opposite to the second coil wiring layer 22 with respect to the upper surface of the first insulating layer 11b. Thus, 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, while suppressing the total thickness of the base body 10, the interlayer insulating portion 110 can be made thicker, and the insulation reliability between the coil wiring layers can be further enhanced.

[0071] 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 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 the photosensitive insulating paste, each insulating layer 11 can be processed using photolithography. By using photolithography, the misalignment (mask alignment misalignment) between the stacked plurality of insulating layers 11 can be suppressed to be sufficiently small with respect to the line width of each coil wiring layer.

[0072] (Examples and Reference Examples) As an example, the inductor component 1 shown in FIGS. 1A to 4 was manufactured, and cross-sectional observations of the juxtaposed portion and the connection portion were performed. FIG. 8 is an electron microscope image showing an example of a cross section of the juxtaposed portion of the inductor component 1. FIG. 9 is an electron microscope image showing an example of a cross section of the connection portion of the inductor component 1.

[0073] From the cross section of the juxtaposed portion 101 shown in FIG. 8, it can be seen that the upper surface of the first coil wiring layer 21 is formed as a concave curved surface. Also, the side surfaces of the first coil wiring layer 21 and the second coil wiring layer 22 are substantially smooth. Further, from the cross section of the connection portion 102 shown in FIG. 9, it can be seen that the conductor composed of the first coil wiring layer 21, the connection conductor 26, and the second coil wiring layer 22 generally has a rectangular shape.

[0074] For comparison, an inductor component of a reference example was fabricated and cross-sectional observation was similarly performed.

[0075] FIG. 10 is a schematic cross-sectional view showing the juxtaposed portion and the connection portion in the inductor component of the reference example. As shown in FIG. 10, in the juxtaposed portion 901 of the reference example, a coil wiring layer 92 is disposed 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, “lid portion”) 91b located above the first insulating layer 11b. The width of the lid portion 91b is larger than the width of the main portion 91a. Similarly, the coil wiring layer 92 has a main portion 92a disposed in a through hole of the second insulating layer 11d and a lid 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 connection portion 902, a connection conductor 96 that connects the coil wiring layer 91 and the coil wiring layer 92 is disposed in a hole penetrating the intermediate insulating layer 11c.

[0076] In the reference example, since the intermediate insulating layer 11c is formed so as to cover the lid portion 91b of the coil wiring layer 91, the portion of the intermediate insulating layer 11c located above the lid portion 91b may be thinner than other portions of the intermediate insulating layer 11c. As a result, the thickness t of the interlayer insulating portion 910 may be smaller than the thickness T of the intermediate insulating layer 11c.

[0077] FIG. 11 and FIG. 12 are electron microscope images showing cross-sections of the juxtaposed portion and the connection portion in the inductor component of the reference example. From the cross-section shown in FIG. 11, it can be seen that in the reference example, the upper surface of the coil wiring layer 91 (the upper surface of the lid portion 91b) is substantially flat. Further, as can be seen from FIGS. 11 and 12, protrusions 920 are formed on the side surfaces of the coil wiring layers 91 and 92 by the lid portions 91b and 92b. The protrusions 920 protrude in a direction orthogonal to the axial direction L.

[0078] The inductor component 1 of the embodiment can have the following advantages over the inductor component of the reference example.

[0079] As described above with reference to FIG. 10, in the inductor component of the reference example, due to the thinning of the intermediate insulating layer 11c, the interlayer insulating portion 910 between the coil wiring layers becomes thin, and the desired insulation may not be obtained. On the other hand, 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 curved surface. Therefore, the interlayer insulating portion 110 having a desired thickness can be more reliably formed. It is also possible to make the thickness of the interlayer insulating portion 110, for example, larger than the thickness T of the intermediate insulating layer 11c. Therefore, the insulation between the coil wiring layers can be enhanced without increasing the thickness of each insulating layer 11.

[0080] Further, as shown in FIGS. 8 and 9, in the inductor component 1, protrusions (see FIGS. 11 and 12) as in the reference example are not formed on the side surfaces of the coil wiring layers 21 and 22, and the side surfaces are smooth. For this reason, it is possible to suppress a decrease in the effective coil inner diameter due to the protrusions. In addition, an increase in the AC resistance Rac due to the protrusions can be suppressed. In the reference example, the lid portions 91b and 92b (protrusions 920) inhibit the magnetic flux in the coil inner diameter portion, and the Q characteristic may deteriorate. On the other hand, according to the inductor component 1 of the embodiment, since the side surfaces of the coil wiring layers 21 and 22 are smooth, it is possible to suppress a decrease in the Q characteristic due to the protrusions.

[0081] Furthermore, in the reference example, as shown in FIG. 10, it is difficult to increase the ratio of the cross-sectional area of the conductor composed of the two coil wiring layers 91 and 92 and the connection conductor 96 in the connection portion 902 to the cross-sectional area of the rectangle 90 composed of the maximum width (for example, the width of the lid portion 92b) and height of the conductor. On the other hand, in the embodiment, the conductor of the connection portion 102 is substantially rectangular, and the above ratio can be made higher than that in the reference example. Therefore, since the wiring cross-sectional area can be increased while suppressing the line width, it becomes possible to reduce the DC resistance Rdc.

[0082] (Modification example) Note that the present invention is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present invention.

[0083] The inductor component of the present invention only needs to have an upper surface in which the first upper surface 21a of the first coil wiring layer 21 is formed as a concave curved surface, and thereby has an effect of enhancing the insulation reliability of the interlayer insulation portion 110. In the example shown in FIG. 3, 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 only a part of the first upper surface 21a of the first coil wiring layer 21 may be located above the upper surface of the first insulating layer 11b. Alternatively, the first coil wiring layer 21 may have a lid portion located on the first insulating layer 11b, and the upper surface of the lid portion may be formed as a concave curved surface.

[0084] The connection conductor 26 and the second coil wiring layer 22 may also each have a portion located above the upper surfaces of the insulating layers 11c and 11d. Further, the upper surfaces of the connection conductor 26 and the second coil wiring layer 22 do not have to be concave curved surfaces, and may be, for example, substantially flat.

[0085] The shape, arrangement, number (number of stacked layers), etc. of the coil wiring layer, connection conductor, and insulating layer are not limited to the examples shown in FIGS. 1A and 1B. For example, in the examples shown in FIGS. 1A and 1B, the coil 20 had a configuration in which a plurality of coil wiring layers with less than one turn were stacked, but the number of turns of the coil wiring layer may be one turn or more. That is, each coil wiring layer may have a planar spiral shape. Also, in FIGS. 1A and 1B, 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 be a direction perpendicular 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.

[0086] The materials and formation methods of the respective components of the inductor component are not particularly limited to the above-described examples. For example, a coloring material such as cobalt may be added to the base body to reduce the transmittance of the product. Thereby, the visibility of the internal coil can be reduced. Also, it is possible to make the materials of the coil wiring layer and the connection conductor different.

[0087] The above description can also be expressed as follows.

[0088] The inductor component of the first aspect is an insulating base body and a coil disposed inside the base body and wound along an axis, and the coil is 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 first direction and extending in a direction intersecting the first direction, and the first coil wiring layer and the second coil wiring layer have opposing portions facing each other through an interlayer insulating portion that is part of the base body, In a cross section orthogonal to the extending direction of the first coil wiring layer in the facing portion, a first upper surface located on the interlayer insulating portion side of the first coil wiring layer is formed of a concave curved surface that extends in a direction opposite to the second coil wiring layer in the first direction from both edge portions of the first upper surface.

[0089] The inductor component of the second aspect is In the inductor component of the first aspect, In a cross section orthogonal to the extending direction of the first coil wiring layer in the facing portion, the width in the direction orthogonal to the first direction of the first upper surface of the first coil wiring layer is larger than the width in the direction orthogonal to the first direction of a first lower surface located on the side opposite to the interlayer insulating portion of the first coil wiring layer.

[0090] The inductor component of the third aspect is In the inductor component of the first aspect or the second aspect, The facing portion includes a juxtaposed portion in which the first coil wiring layer and the second coil wiring layer extend in the same direction with the interlayer insulating portion therebetween. In a cross section orthogonal to the extending direction of the first coil wiring layer in the juxtaposed portion, the width in the direction orthogonal to the first direction of the first upper surface is larger than the width in the direction orthogonal to the first direction of a second lower surface located on the interlayer insulating portion side of the second coil wiring layer.

[0091] The inductor component of the fourth aspect is In the inductor component of the third aspect, In a cross section orthogonal to the extending direction of the first coil wiring layer in the juxtaposed portion, the thickness of the interlayer insulating portion in the first direction increases from both edge portions sides of the second lower surface toward the central portion side.

[0092] The inductor component of the fifth aspect is In the inductor component of the third aspect or the fourth aspect, When viewed in plan from the first direction, in the juxtaposed portion, the second lower surface of the second coil wiring layer is located inside both edge portions of the first upper surface of the first coil wiring layer.

[0093] The inductor component of the sixth aspect is In any one of the inductor components of the first aspect to the fifth aspect, In a cross-section orthogonal to the extending direction of the first coil wiring layer, The first coil wiring layer has a first upper surface, a first lower surface located on the side opposite to the interlayer insulating portion of the first coil wiring layer, 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.

[0094] The inductor component of the seventh aspect is In any one of the inductor components of the first aspect to the sixth aspect, It further includes a connection conductor that electrically connects a part of the first coil wiring layer and a part of the second coil wiring layer. The connection conductor is disposed inside a hole that penetrates the interlayer insulating portion in the first direction.

[0095] The inductor component of the eighth aspect is In any one of the inductor components of the first aspect to the seventh aspect, The interlayer insulating portion includes a filler material and a glass material.

[0096] The inductor component of the ninth aspect is In any one of the inductor components of the first aspect to the eighth aspect, The base body is composed of a plurality of insulating layers stacked in the first direction. The plurality of insulating layers are A first insulating layer, A second insulating layer, In the first direction, an intermediate insulating layer located between the first insulating layer and the second insulating layer, and includes. The first coil wiring layer is disposed inside the first insulating layer. The second coil wiring layer is disposed 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 part of the interlayer insulating portion has a portion protruding toward the first insulating layer side, and the first upper surface of the first coil wiring layer is in contact with the portion of the interlayer insulating portion protruding toward the first insulating layer side and is located on the side opposite to the second coil wiring layer from the upper surface of the first insulating layer in the first direction.

Industrial Applicability

[0097] Since the inductor component of the present invention has high insulation between coil wiring layers, for example, it is used as a coil for impedance matching (matching coil) in a high-frequency circuit and is used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, car electronics, and medical and industrial machines. The inductor component of the present invention can also be suitably applied to tuning circuits, filter circuits, rectifying and smoothing circuits, and the like.

Explanation of Signs

[0098] 1 Inductor component 10 Element body 11 Insulating layer 11b First insulating layer 11c Intermediate insulating layer 11d Second insulating layer 15 First end face 16 Second end face 17 Bottom face 18 Top face 20 Coil 21 First coil wiring layer 22 Second coil wiring layer 23 - 25 Coil wiring layers 21a First upper surface 21b First lower surface 21c First side face 22a Second upper surface 22b Second lower surface 22c Second side face 26 Connection conductor 30 First external electrode 40 Second external electrode 101 juxtaposition part 102 connection part 110 interlayer insulation part 111b~111d holes A stacking direction AX axis L-axis direction p1, p2 edges s1 first interface s2 second interface v virtual line w1~w4 wiring widths

Claims

1. An insulating body; a coil disposed inside the element and wound along an axis, The coil is a first coil wiring layer extending in a direction intersecting a first direction parallel to the axis; a second coil wiring layer disposed 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 element body, An inductor component, wherein in a cross section at the opposing portion perpendicular to the extension direction of the first coil wiring layer, a first upper surface located on the interlayer insulation side of the first coil wiring layer is formed with a concave curved surface extending from both edges of the first upper surface in the opposite direction to the second coil wiring layer in the first direction.

2. The inductor component of claim 1, wherein in a cross section in the opposing portion perpendicular to the extension direction of the first coil wiring layer, the width of the first upper surface of the first coil wiring layer in a direction perpendicular to the first direction is larger than the width of a first lower surface of the first coil wiring layer located on the opposite side of the interlayer insulation portion.

3. the opposing portion includes a juxtaposition portion in which the first coil wiring layer and the second coil wiring layer extend in the same direction with the interlayer insulating portion interposed therebetween, 3. An inductor component as described in claim 1 or 2, wherein in a cross section in the juxtaposition portion perpendicular to the extension direction of the first coil wiring layer, the width of the first upper surface in a direction perpendicular to the first direction is greater than the width of a second lower surface located on the interlayer insulation side of the second coil wiring layer in a direction perpendicular to the first direction.

4. The inductor component of claim 3, wherein in a cross section in the juxtaposed portion perpendicular to the extension direction of the first coil wiring layer, the thickness of the interlayer insulation portion in the first direction increases from both edge sides of the second lower surface toward the central portion.

5. The inductor component of claim 3 , wherein, when viewed in a plane from the first direction, in the juxtaposition portion, the second lower surface of the second coil wiring layer is located inside the two edges of the first upper surface of the first coil wiring layer.

6. In a cross section perpendicular to the extending direction of the first coil wiring layer, the first coil wiring layer has the first upper surface, a first lower surface located on the side of the first coil wiring layer opposite the interlayer insulating portion, and a side surface connecting the first upper surface and the first lower surface, The inductor component according to claim 1 , wherein the side surface of the first coil wiring layer is smooth.

7. a connection conductor electrically connecting a portion of the first coil wiring layer and a portion of the second coil wiring layer, the connection conductor is disposed inside a hole penetrating the interlayer insulating portion in the first direction. The inductor component according to claim 1 .

8. The inductor component according to claim 1 , wherein the interlayer insulating portion includes a filler material and a glass material.

9. the element body is composed of a plurality of insulating layers stacked in the first direction, The plurality of insulating layers include A first insulating layer; A second insulating layer; 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 disposed inside the first insulating layer, the second coil wiring layer is disposed 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, 3. The inductor component of claim 1, wherein the first upper surface of the first coil wiring layer is in contact with a portion of the interlayer insulation portion that protrudes toward the first insulating layer, and is located on the opposite side of the second coil wiring layer in the first direction from the upper surface of the first insulating layer.

Images