Inductor Components

Abstract

To provide an inductor component which can prevent cracking caused by stress generated on a boundary surface between internal wiring and an insulation layer.SOLUTION: An inductor component 1A includes: an element assembly 10 including an insulation layer 15b; internal wiring 25 at least part of which is electrically connected so as to form a spirally wound coil 20, and which is provided inside the element assembly 10; and an external electrode electrically connected to the coil 20. The insulation layer 15b is provided with a groove 40 which extends in a manner inclined to a surface of the internal wiring 25, with a boundary surface between the internal wiring 25 and the insulation layer 15b serving as a starting point.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 discloses an electronic component comprising a laminate, a spiral coil provided within the laminate, the coil being composed of a plurality of coil conductor layers that overlap each other to form a circular track when viewed in a plane from the stacking direction, and a plurality of via hole conductors connecting the plurality of coil conductor layers, wherein the circular track has a plurality of first corners that protrude outward and a second corner that protrudes inward, and all of the via hole conductors are provided at the first corners.

[0003] Patent Document 2 discloses a method for manufacturing an inductor component, the method comprising the steps of preparing a photosensitive insulating paste and a conductive paste containing a filler material made of quartz, a glass material, and a resin material; applying the insulating paste to form a first insulating layer; exposing the first insulating layer to light while blocking a first portion of the first insulating layer with a mask; removing the first portion of the first insulating layer to form a groove whose depth is greater than the groove width at a position corresponding to the first portion; applying the conductive paste into the groove to form a coil conductor layer in the groove; and applying the insulating paste onto the first insulating layer and the coil conductor layer to form a second insulating layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5459327 [Patent Document 2] Patent No. 6787286 Summary of the Invention [Problem to be solved by the invention]

[0005] As the performance of various devices such as communication devices improves, higher performance is required not only for the circuit boards that make up the devices, but also for the inductor components mounted on those circuit boards. For example, for inductor components used in high frequency bands, low resistance wiring is required to achieve excellent coil characteristics.

[0006] However, the inventors have conducted research and found that when forming internal wiring (including coil wiring) on ​​an insulating layer as in Patent Document 1 during the manufacturing process of an inductor component, it is difficult to increase the thickness of the internal wiring, and as a result, it is difficult to reduce the resistance of the internal wiring, for the following reasons: (1) there is a limit to how thickly the conductive material that constitutes the internal wiring can be applied; and (2) even if it is possible to apply the conductive material that constitutes the internal wiring thickly, there is a limit to how thickly the insulating material that constitutes the insulating layer can be applied to cover the internal wiring.

[0007] In response to this, the inventors have conducted research and found that in the manufacturing process of inductor components, by forming a groove in the insulating layer whose depth is greater than the groove width, as in Patent Document 2, and then filling the groove with a conductive material while also applying a conductive material onto the insulating layer, it is possible to form thick internal wiring, and as a result, to reduce the resistance of the internal wiring.

[0008] However, the inventors of the present invention have found that, when thick internal wiring is formed as in Patent Document 2 during the manufacturing process of an inductor component, the volume ratio of the internal wiring to the element body increases, which increases the difference in thermal shrinkage between the internal wiring and the insulating layer, making it more likely that stress will occur at the interface between the internal wiring and the insulating layer. Furthermore, the inventors have found that, particularly when miniaturizing an inductor component or thickening the internal wiring, if stress occurs at the interface between the internal wiring and the insulating layer during the manufacturing process of the inductor component, thermal shock will be applied to the inductor component during the firing process, the reflow process during the mounting process of the inductor component, or physical loads (mechanical loads) will be applied to the inductor component during other processes. This stress will cause interfacial delamination between the internal wiring and the insulating layer, resulting in cracks along the internal wiring inside the element body. Furthermore, the inventors have found that if such cracks reach the surface of the element body, moisture, corrosive gases, and the like will penetrate into the element body through the cracks, thereby reducing the reliability of the inductor component.

[0009] The present invention has been made to solve the above problems, and aims to provide an inductor component that can suppress the occurrence of cracks caused by stress occurring at the interface between the internal wiring and the insulating layer. [Means for solving the problem]

[0010] The inductor component of the present invention comprises an element body including an insulating layer, at least a portion of which is electrically connected to form a spirally wound coil, and also comprises internal wiring provided inside the element body, and an external electrode electrically connected to the coil, and is characterized in that the insulating layer has a groove extending at an angle relative to the surface of the internal wiring, starting from the interface between the internal wiring and the insulating layer. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an inductor component that can suppress the occurrence of cracks due to stress occurring at the interface between the internal wiring and the insulating layer. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic perspective view showing an example of an inductor component according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a cross section of the inductor component shown in FIG. 1 taken along line a1-a2. [Figure 3] FIG. 3 is a cross-sectional view showing an example of an inductor component according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically illustrating an example of an inductor component according to a third embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view showing an example of an inductor component according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The inductor component of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate without departing from the spirit of the present invention. Furthermore, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0014] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From embodiment 2 onwards, descriptions of matters common to embodiment 1 will be omitted, and differences will be mainly described. In particular, similar effects due to similar configurations will not be mentioned one after the other for each embodiment.

[0015] In the following description, when no particular distinction is made between the embodiments, they will simply be referred to as "the inductor component of the present invention."

[0016] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0017] In this specification, terms indicating the relationship between elements (e.g., "parallel," "perpendicular," "orthogonal," etc.) and terms indicating the shape of elements not only mean the literal and strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[0018] The inductor component of the present invention comprises an element body including an insulating layer, at least a portion of which is electrically connected to form a spirally wound coil, and also comprises internal wiring provided inside the element body, and an external electrode electrically connected to the coil, and is characterized in that the insulating layer has a groove extending at an angle relative to the surface of the internal wiring, starting from the interface between the internal wiring and the insulating layer.

[0019] [Embodiment 1] An example of the inductor component of the present invention will be described below as an inductor component according to a first embodiment of the present invention.

[0020] FIG. 1 is a schematic perspective view showing an example of an inductor component according to a first embodiment of the present invention.

[0021] The inductor component 1A shown in FIG. 1 includes an element body 10, a coil 20, a first external electrode 30a, and a second external electrode 30b.

[0022] In this specification, the length direction, height direction, and width direction are defined as directions L, T, and W, respectively, as shown in Fig. 1 etc. Here, the length direction L, height direction T, and width direction W are perpendicular to each other.

[0023] 1, in inductor component 1A, the surface of element body 10 includes end faces 11a and 11b facing in length direction L, top face 12a and bottom face 12b facing in height direction T, and side faces 13a and 13b facing in width direction W. In inductor component 1A, width direction W is parallel to the coil axis direction of coil 20. That is, in inductor component 1A, the surface of element body 10 includes bottom face 12b parallel to the coil axis direction and top face 12a facing bottom face 12b in height direction T perpendicular to the coil axis direction.

[0024] In this embodiment, the coil axis direction is parallel to the width direction W unless otherwise specified.

[0025] In inductor component 1A, bottom surface 12b of element body 10 is the mounting surface. More specifically, bottom surface 12b of element body 10 is the mounting surface that faces an object to be mounted (e.g., a substrate) when inductor component 1A is mounted. Therefore, in inductor component 1A, the mounting surface of element body 10, i.e., bottom surface 12b of element body 10, is parallel to the coil axis direction.

[0026] At least one of the surfaces of the element body 10, i.e., end surface 11a, end surface 11b, top surface 12a, bottom surface 12b, side surface 13a, and side surface 13b, may be marked to make each surface easier to identify.

[0027] The end faces 11a and 11b of the element body 10 do not need to be strictly perpendicular to the length direction L. Furthermore, the top face 12a and bottom face 12b of the element body 10 do not need to be strictly perpendicular to the height direction T. Furthermore, the side faces 13a and 13b of the element body 10 do not need to be strictly perpendicular to the width direction W.

[0028] As shown in FIG. 1, the element body 10 has, for example, a rectangular parallelepiped shape.

[0029] In this specification, the rectangular parallelepiped shape may refer to any shape that can be said to be substantially rectangular parallelepiped, and includes, for example, a roughly rectangular parallelepiped shape with rounded corners and ridges as described below.

[0030] It is preferable that the corners and ridges of the element body 10 are rounded. A corner of the element body 10 is a portion where three faces of the element body 10 intersect. A ridge of the element body 10 is a portion where two faces of the element body 10 intersect.

[0031] As shown in FIG. 1, the element body 10 includes an insulating layer.

[0032] In the example shown in FIG. 1, the element body 10 is formed by laminating a plurality of insulating layers in the coil axis direction.

[0033] In the example shown in FIG. 1, the plurality of insulating layers includes insulating layer 15a, insulating layer 15b, insulating layer 15c, and insulating layer 15d.

[0034] Although not shown in FIG. 1, at least one insulating layer exists between insulating layer 15b and insulating layer 15c in the coil axis direction.

[0035] In FIG. 1, for the sake of convenience, boundaries between a plurality of insulating layers are shown, but in reality, these boundaries are not clearly visible.

[0036] Examples of insulating materials that form the insulating layer include glass materials containing borosilicate glass as a main component, ceramic materials, organic materials such as epoxy resins, fluororesins, and polymer resins, and composite materials such as glass epoxy resins. As the insulating material, materials with small dielectric constants and dielectric loss are particularly preferred.

[0037] The insulating materials constituting the plurality of insulating layers may be the same as each other, may be different from each other, or may be partially different from each other.

[0038] The dimensions of the insulating layers in the coil axis direction may be the same as each other, may be different from each other, or may be partially different from each other.

[0039] As shown in FIG. 1, the coil 20 is provided inside the element body 10 and is wound spirally along the coil axis direction.

[0040] The coil axis direction of the coil 20 is the direction in which the coil axis C of the coil 20 extends, and is parallel to the bottom surface 12b, which is the mounting surface of the element body 10, as described above.

[0041] The coil 20 is configured in a spirally wound state by electrically connecting at least a portion of the internal wiring 25 provided inside the element body 10 .

[0042] The internal wiring 25 includes a first internal wiring 25a and a second internal wiring 25b.

[0043] The first internal wiring 25a is located at the outermost position of the internal wiring 25 on the side surface 13a side of the element body 10 in the coil axis direction.

[0044] The first internal wiring 25a is connected to the first external electrode 30a.

[0045] The second internal wiring 25b is located at the outermost position of the internal wiring 25 on the side surface 13b side of the element body 10 in the coil axis direction.

[0046] The second internal wiring 25b is connected to the second external electrode 30b.

[0047] Although not shown in FIG. 1, at least one internal wire exists between the first internal wire 25a and the second internal wire 25b in the coil axis direction.

[0048] The first internal wiring 25a includes a first coil wiring 21a and a first lead wiring 22a.

[0049] The second internal wiring 25b includes a second coil wiring 21b and a second lead wiring 22b.

[0050] The coil 20 is formed by stacking and electrically connecting a plurality of coil wirings including at least a part of the internal wiring 25, more specifically, the first coil wiring 21 a and the second coil wiring 21 b, in the coil axial direction. That is, the first coil wiring 21 a and the second coil wiring 21 b each constitute the coil 20.

[0051] The first coil wiring 21a may have a single-layer structure or a multi-layer structure.

[0052] The second coil wiring 21b may have a single-layer structure or a multi-layer structure.

[0053] Although not shown in FIG. 1, at least one coil wire exists between the first coil wire 21a and the second coil wire 21b in the coil axis direction.

[0054] Examples of conductive materials that form the coil wiring include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0055] The conductive materials constituting the multiple coil wirings may be the same as each other, may be different from each other, or may be partially different from each other.

[0056] The dimensions of the multiple coil wires in the coil axis direction may be the same as each other, may be different from each other, or may be partially different.

[0057] For multiple coil wirings, the dimensions in a direction perpendicular to the direction in which the coil wiring extends when viewed from the coil axis direction, i.e., the widths when viewed from the coil axis direction, may be the same as each other, may be different from each other, or may be different in some areas.

[0058] Among the multiple coil wirings, adjacent coil wirings in the coil axis direction may be electrically connected via a connecting conductor that penetrates an insulating layer between the adjacent coil wirings in the coil axis direction. In other words, the coil 20 may be formed by stacking multiple coil wirings in the coil axis direction and electrically connecting them via a connecting conductor.

[0059] The connecting conductor may have a single-layer structure or a multi-layer structure.

[0060] Examples of conductive materials that form the connecting conductor include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0061] As described above, in the example shown in FIG. 1, the coil 20 is configured with three or more coil wirings, including the first coil wiring 21a, the second coil wiring 21b, and at least one other coil wiring. However, by adjusting the position of the connecting conductor, it is possible to configure the coil 20 with only the first coil wiring 21a and the second coil wiring 21b.

[0062] When viewed from the coil axial direction, the coil 20 may have a shape consisting of only straight portions, a shape consisting of only curved portions, or a shape consisting of straight portions and curved portions. For example, when viewed from the coil axial direction, the coil 20 may have a circular shape, an elliptical shape, or a polygonal shape.

[0063] 1, the first external electrode 30a is electrically connected to one end of the coil 20. More specifically, as shown in Fig. 1, the first coil wiring 21a constituting the coil 20 is electrically connected to the first external electrode 30a via the first escape wiring 22a. In other words, the first escape wiring 22a connects the first coil wiring 21a and the first external electrode 30a.

[0064] The first escape routing 22a may have a single-layer structure or a multi-layer structure.

[0065] 1, the second external electrode 30b is electrically connected to the other end of the coil 20. More specifically, as shown in Fig. 1, the second coil wiring 21b constituting the coil 20 is electrically connected to the second external electrode 30b via the second escape wiring 22b. In other words, the second escape wiring 22b connects the second coil wiring 21b and the second external electrode 30b.

[0066] The second escape routing 22b may have a single-layer structure or a multi-layer structure.

[0067] Examples of conductive materials that form the lead wiring include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0068] The conductive materials forming the first escape routing 22a and the second escape routing 22b may be the same as or different from each other.

[0069] In this specification, the term "draw-out wiring" refers to wiring that extends toward the external electrode while being inclined with respect to the linear portion of the coil wiring in the path where the coil wiring is electrically connected to the external electrode when viewed from the coil axis direction (for example, the example shown in Figure 1). In this case, when viewed from the coil axis direction, the coil wiring and the draw-out wiring are not on the same straight line with their connection portion as the boundary. Note that if no wiring that corresponds to the draw-out wiring defined above is found when viewed from the coil axis direction, the draw-out wiring is wiring that does not overlap the winding portion of the coil (protrudes from the winding portion of the coil) when viewed from the coil axis direction (for example, an example different from Figure 1).

[0070] As shown in FIG. 1, the first external electrode 30a is preferably exposed at least on the bottom surface 12b of the element body .

[0071] 1, the first external electrode 30a extends from part of the bottom surface 12b to part of the end surface 11a of the element body 10. In other words, in the example shown in Fig. 1, the first external electrode 30a is exposed not only on part of the bottom surface 12b of the element body 10 but also on part of the end surface 11a of the element body 10.

[0072] The first external electrode 30a may be exposed only on the bottom surface 12b of the element body .

[0073] As shown in FIG. 1, the second external electrode 30b is preferably exposed at least on the bottom surface 12b of the element body .

[0074] 1, the second external electrode 30b extends from part of the bottom surface 12b to part of the end surface 11b of the element body 10. In other words, in the example shown in Fig. 1, the second external electrode 30b is exposed not only on part of the bottom surface 12b of the element body 10 but also on part of the end surface 11b of the element body 10.

[0075] The second external electrode 30b may be exposed only on the bottom surface 12b of the element body .

[0076] As described above, the first external electrode 30a and the second external electrode 30b are provided so as to be spaced apart from each other in the direction (here, the length direction L) perpendicular to the coil axis direction.

[0077] Furthermore, if the first external electrode 30a and the second external electrode 30b are exposed on the bottom surface 12b of the element body 10, which is the mounting surface, the mountability of the inductor component 1A is likely to be improved.

[0078] In the example shown in FIG. 1, the dimension of the first external electrode 30a in the coil axis direction is smaller than the dimension of the element body 10 in the coil axis direction.

[0079] The dimension of the first external electrode 30a in the coil axis direction may be the same as the dimension of the element body 10 in the coil axis direction.

[0080] In the example shown in FIG. 1, the dimension of the second external electrode 30b in the coil axis direction is smaller than the dimension of the element body 10 in the coil axis direction.

[0081] The dimension of the second external electrode 30b in the coil axis direction may be the same as the dimension of the element body 10 in the coil axis direction.

[0082] Examples of conductive materials that can be used to form the external electrodes include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0083] The conductive materials that make up the first external electrode 30a and the second external electrode 30b may be the same as or different from each other.

[0084] The first external electrode 30a may have a single-layer structure or a multi-layer structure.

[0085] The first external electrode 30a may have, in this order from the coil 20 side, a base electrode containing the above-mentioned conductive material (for example, Ag), a Ni-plated electrode, and a Sn-plated electrode. In this case, in the first external electrode 30a, the base electrode may form an integral surface with the surface of the element body 10 (in FIG. 1, the end face 11a and bottom face 12b of the element body 10), and the Ni-plated electrode and the Sn-plated electrode may protrude from the surface of the element body 10 (in FIG. 1, the end face 11a and bottom face 12b of the element body 10) so as to cover the base electrode.

[0086] The second external electrode 30b may have a single-layer structure or a multi-layer structure.

[0087] The second external electrode 30b may have, in this order from the coil 20 side, a base electrode containing the above-mentioned conductive material (for example, Ag), a Ni-plated electrode, and a Sn-plated electrode. In this case, in the second external electrode 30b, the base electrode may form an integral surface with the surface of the element body 10 (in FIG. 1, the end face 11b and bottom face 12b of the element body 10), and the Ni-plated electrode and the Sn-plated electrode may protrude from the surface of the element body 10 (in FIG. 1, the end face 11b and bottom face 12b of the element body 10) so as to cover the base electrode.

[0088] Fig. 2 is a cross-sectional schematic diagram showing an example of a cross section taken along line a1-a2 of the inductor component shown in Fig. 1. More specifically, Fig. 2 shows a cross section including the first internal wiring 25a (the first coil wiring 21a and the first escape wiring 22a) of the inductor component 1A shown in Fig. 1 taken along the length direction L and height direction T.

[0089] As shown in FIG. 2, a groove 40 is provided in the insulating layer 15b.

[0090] As shown in FIG. 2, the groove 40 starts at the interface between the first internal wiring 25a and the insulating layer 15b and extends at an angle relative to the surface of the first internal wiring 25a.

[0091] In this specification, the aspect in which the groove extends from the interface between the internal wiring and the insulating layer as an origin at an angle with respect to the surface of the internal wiring means an aspect in which the angle between the direction in which the groove extends near the origin and the direction along the surface of the internal wiring is 30° or more. For example, in the inductor component 1A, the angle between the direction in which the groove 40 extends near the interface (origin) between the first internal wiring 25a and the insulating layer 15b and the direction along the surface of the first internal wiring 25a may be 45° or more, or may be 90°, as long as it is 30° or more.

[0092] In the inductor component 1A, the insulating layer 15b is provided with a groove 40 that starts at the interface between the first internal wire 25a and the insulating layer 15b and extends at an angle relative to the surface of the first internal wire 25a. Therefore, even if stress occurs at the interface between the first internal wire 25a and the insulating layer 15b due to differences in the amounts of thermal contraction between the first internal wire 25a and the insulating layer 15b during the manufacturing process of the inductor component 1A, the stress is released by the groove 40. As a result, even if the inductor component 1A is subjected to thermal shock during a firing process in the manufacturing process, a reflow process in the mounting process, or the like, or is subjected to physical load (mechanical load) during other processes, interfacial peeling between the first internal wire 25a and the insulating layer 15b due to stress occurring at the interface between the first internal wire 25a and the insulating layer 15b is suppressed, and as a result, the occurrence of cracks along the first internal wire 25a inside the element body 10 is suppressed.

[0093] In the inductor component 1A, for example, in order to reduce the resistance of the first internal wiring 25a and improve the coil characteristics, the dimension of the first internal wiring 25a in the coil axis direction is increased. As a result, even if stress occurs at the interface between the first internal wiring 25a and the insulating layer 15b, the stress is released by the groove 40, and as a result, the occurrence of cracks inside the base body 10 is suppressed.

[0094] Therefore, the inductor component 1A can suppress the occurrence of cracks due to stress occurring at the interface between the first internal wiring 25a and the insulating layer 15b. Furthermore, the inductor component 1A can suppress the occurrence of cracks due to stress occurring at the interface between the first internal wiring 25a and the insulating layer 15b, while reducing the resistance of the first internal wiring 25a and improving the coil characteristics.

[0095] 2, the groove 40 originates at the interface between the first internal wire 25a and the insulating layer 15b and extends at an angle relative to the surface of the first internal wire 25a, but the groove 40 may originate at the interface between the first internal wire 25a and an insulating layer other than the insulating layer 15b (e.g., the insulating layer 15a) and extend at an angle relative to the surface of the first internal wire 25a. Alternatively, the groove 40 may originate at the interface between an internal wire other than the first internal wire 25a (e.g., the second internal wire 25b) and an insulating layer (e.g., the insulating layer 15c) and extend at an angle relative to the surface of an internal wire other than the first internal wire 25a (e.g., the second internal wire 25b).

[0096] Thus, in the inductor component 1A, the groove 40 starts from the interface between the internal wiring 25 and the insulating layer (including insulating layer 15a, insulating layer 15b, insulating layer 15c, and insulating layer 15d) and extends at an angle relative to the surface of the internal wiring 25.

[0097] Therefore, the inductor component 1A can realize an inductor component that can suppress the occurrence of cracks due to stress occurring at the interface between the internal wiring 25 and the insulating layer. Furthermore, the inductor component 1A can realize an inductor component that can reduce the resistance of the internal wiring 25 and improve the coil characteristics while suppressing the occurrence of cracks due to stress occurring at the interface between the internal wiring 25 and the insulating layer.

[0098] Furthermore, in inductor component 1A, the occurrence of cracks inside element body 10 is suppressed, and therefore a decrease in reliability due to moisture, corrosive gases, etc. penetrating into element body 10 through cracks is also suppressed.

[0099] On the other hand, in the inductor component 1A, the internal wiring 25 is connected to the surface of the element body 10 via the first external electrode 30a at the first internal wiring 25a, particularly the first escape wiring 22a. Therefore, in the inductor component 1A, if a crack occurs along the internal wiring 25 inside the element body 10 due to stress generated at the interface between the internal wiring 25 and the insulating layer, it is expected that the crack will reach the surface of the element body 10 along the first internal wiring 25a, particularly the first escape wiring 22a, thereby reducing reliability.

[0100] In contrast, as shown in Fig. 2, it is preferable that the groove 40 originates at the interface between the first internal wiring 25a and the insulating layer 15b and extends at an angle with respect to the surface of the first internal wiring 25a.More preferably, as shown in Fig. 2, it is preferable that the groove 40 originates at the interface between the first escape routing 22a and the insulating layer 15b and extends at an angle with respect to the surface of the first escape routing 22a.

[0101] In the inductor component 1A, in particular, the groove 40 starts from the interface between the first escape wiring 22a and the insulating layer 15b and extends at an angle relative to the surface of the first escape wiring 22a. This allows the groove 40 to release the stress generated at the interface between the first escape wiring 22a and the insulating layer 15b, thereby not only suppressing the occurrence of cracks along the first escape wiring 22a inside the element body 10, but also making it less likely that even if a crack does occur, the crack will reach the surface of the element body 10.

[0102] The groove 40 may be straight, curved, or a combination of straight and curved shapes. In these cases, the groove 40 may be bent midway.

[0103] The position of the groove 40 relative to the internal wire 25 is not particularly limited as long as the groove 40 starts at the interface between the internal wire 25 and the insulating layer and extends at an angle relative to the surface of the internal wire 25. For example, when viewed from the coil axis direction, the groove 40 may be provided on the outer peripheral edge side of the internal wire 25 (in FIG. 2, the first lead wiring 22a of the first internal wire 25a), or on the inner peripheral edge side of the internal wire 25. Furthermore, when viewed from a direction orthogonal to the coil axis direction (here, a direction including the length direction L and the height direction T), the groove 40 may be provided on the side of the side surface 13a of the element body 10 (the front side of the paper in FIG. 2) or on the side of the side surface 13b of the element body 10 (the back side of the paper in FIG. 2) relative to the surface of the internal wire 25.

[0104] The direction in which the grooves 40 extend is not particularly limited as long as they start from the interface between the internal wiring 25 and the insulating layer and extend at an angle with respect to the surface of the internal wiring 25. For example, the grooves 40 may extend in the coil axis direction, in a direction perpendicular to the coil axis direction, or in a direction other than these.

[0105] The maximum width of the groove 40 is preferably 0.25 μm or less.

[0106] By making the maximum width of grooves 40 0.25 μm or less, the width of grooves 40 is sufficiently smaller than the size of the conductor coarse particles contained in the photosensitive conductive paste used to form internal wiring 25, as described below, and therefore the conductive material that makes up internal wiring 25 is prevented from entering grooves 40 during the firing step in the manufacturing process of inductor component 1A. When the conductive material that makes up internal wiring 25 is prevented from entering grooves 40, the shape of grooves 40 is maintained, and exposure of internal wiring 25 to the surface of element body 10 through grooves 40 is prevented, and adjacent internal wirings (coil wiring) are prevented from short-circuiting through grooves 40.

[0107] The maximum width of the groove 40 is preferably 0.020 μm or more.

[0108] The groove width is determined as follows. First, the inductor component is processed (e.g., polished, cut, etc.) until the internal wiring is exposed, thereby exposing a cross section including the interface between the internal wiring and the insulating layer. Then, by observing the cross section with a field emission scanning electron microscope (FE-SEM) or the like, the dimension of the groove formed starting from the interface between the internal wiring and the insulating layer in a direction perpendicular to the groove extension direction is measured, and this is determined as the groove width. In other words, the groove width is determined as the dimension in a direction perpendicular to the direction in which the groove length, which will be described later, is determined. The maximum value of the groove widths measured in this manner is determined as the maximum groove width.

[0109] The maximum length of the groove 40 is preferably 1.75 μm or less.

[0110] By setting the maximum length of groove 40 to 1.75 μm or less, the length of groove 40 becomes sufficiently smaller than the distance between the surface of internal wiring 25 and the surface of element body 10, and therefore even if the conductive material that makes up internal wiring 25 enters groove 40 during the firing step in the manufacturing process of inductor component 1A, internal wiring 25 is prevented from being exposed to the surface of element body 10 through groove 40. Preventing internal wiring 25 from being exposed to the surface of element body 10 through groove 40 prevents internal wiring 25 from being exposed to moisture, corrosive gases, and the like.

[0111] Furthermore, since the maximum length of the groove 40 is 1.75 μm or less, the length of the groove 40 is sufficiently smaller than the distance between adjacent internal wirings (coil wirings). Therefore, even if the conductive material constituting the internal wiring 25 enters the groove 40 during the firing process in the manufacturing process of the inductor component 1A, short-circuiting between adjacent internal wirings (coil wirings) through the groove 40 is prevented.

[0112] The inside of the groove 40 may be hollow, or may be at least partially filled with the conductive material that constitutes the internal wiring 25, or may be at least partially filled with a material that is different from both the conductive material that constitutes the internal wiring 25 and the insulating material that constitutes the insulating layer 15b.

[0113] The maximum length of the groove 40 is preferably 0.3 μm or more.

[0114] The groove length is determined as follows: By observing the cross section of the inductor component exposed when determining the groove width described above using a field emission scanning electron microscope or the like, the dimension of the groove formed starting from the interface between the internal wiring and the insulating layer in the direction in which the groove extends (the direction in which the groove moves away from the internal wiring) is measured, and this is determined as the groove length. The maximum of the groove lengths measured in this manner is determined as the maximum groove length.

[0115] When determining the width and length of the groove, the cross section of the inductor component may be observed as a cross section perpendicular to the coil axis direction, a cross section parallel to the coil axis direction, or another cross section. In the inductor component 1A shown in Figure 1, the cross section perpendicular to the coil axis direction is a cross section along the length direction L and the height direction T. In the inductor component 1A shown in Figure 1, the cross section parallel to the coil axis direction includes a cross section along the length direction L and the width direction W, and a cross section along the height direction T and the width direction W.

[0116] The method for observing the cross section of the inductor component when determining the width and length of the groove is preferably the method using the field emission scanning electron microscope described above, from the viewpoint of being able to detect the grooves with high sensitivity. Note that the method for observing the cross section of the inductor component when determining the width and length of the groove is not limited to the method using the field emission scanning electron microscope, and other methods may also be used.

[0117] In Figure 2, in order to highlight the groove 40, the width and length of the groove 40 are shown at a relatively large ratio to the size of the insulating layer surrounding the internal wiring 25 (e.g., the distance between the surface of the internal wiring 25 and the surface of the base body 10, the distance between adjacent internal wirings (coil wiring), etc.), but in reality, the size of the insulating layer surrounding the internal wiring 25 may be sufficiently larger (e.g., about 10 times) than the width and length of the groove 40.

[0118] The inductor component 1A is manufactured, for example, by the following method.

[0119] <Step of Producing Mother Laminate> First, an insulating paste layer is formed by repeatedly applying an insulating paste containing a glass material, etc., whose main component is borosilicate glass, by screen printing, etc. The insulating paste layer formed here will later become the insulating layer 15a.

[0120] Next, a photosensitive conductive paste layer is formed on the insulating paste layer by screen printing or the like using a photosensitive conductive paste primarily composed of a metal such as Ag. The photosensitive conductive paste layer is then irradiated with ultraviolet light or the like through a photomask and then developed with an alkaline solution or the like to form a coil conductor layer, an external conductor layer, and an extension conductor layer connected to the coil conductor layer and the external conductor layer on the insulating paste layer. In this manner, the coil conductor layer, the extension conductor layer, and the external conductor layer are formed in multiple locations by photolithography. The coil conductor layer formed here will later become the first coil wiring 21a. The extension conductor layer formed here will later become the first extension wiring 22a connecting the first coil wiring 21a and the first external electrode 30a. In other words, the internal conductor layer, including the coil conductor layer and the extension conductor layer formed here, will later become the first internal wiring 25a. The external conductor layer formed here will later become part of each of the first external electrode 30a and the second external electrode 30b.

[0121] In addition, when forming the coil conductor layer, the lead conductor layer, and the external conductor layer, instead of exposure using a photomask, for example, DI exposure (also called direct image exposure or direct writing) without using a photomask may be performed.

[0122] Next, a new insulating paste layer is formed on the already formed insulating paste layer, for example, by applying a photosensitive insulating paste by screen printing or the like. Furthermore, the newly formed insulating paste layer is irradiated with ultraviolet light or the like through a photomask, and then developed with an alkaline solution or the like, thereby forming via holes and openings in the insulating paste layer. In this manner, an insulating paste layer with via holes and openings provided in multiple locations is formed by photolithography. The insulating paste layer formed here includes an insulating paste layer that will later become insulating layer 15b. The via holes formed here overlap portions of the already formed coil conductor layers. The openings formed here overlap the already formed external conductor layers.

[0123] When forming the insulating paste layer provided with the via holes and openings, for example, DI exposure without using a photomask may be performed instead of exposure using a photomask.

[0124] Next, a new photosensitive conductive paste layer is formed inside the via holes and openings, for example, by applying a photosensitive conductive paste primarily composed of Ag or the like by screen printing or the like, and on the already formed insulating paste layer. The photosensitive conductive paste layer is then irradiated with ultraviolet light or the like through a photomask, and then developed with an alkaline solution or the like, thereby forming a connecting conductor layer inside the via holes and forming a new coil conductor layer connected to the connecting conductor layer on the insulating paste layer. Furthermore, a new external conductor layer connected to the already formed external conductor layer is formed inside the openings, and a new external conductor layer is formed on the external conductor layer. In this manner, the coil conductor layer, the connecting conductor layer, and the external conductor layer are formed by photolithography. The connecting conductor layer formed here will later become the connecting conductor that connects adjacent coil wirings in the coil axis direction.

[0125] When forming the coil conductor layer, the connection conductor layer, and the external conductor layer, for example, DI exposure without using a photomask may be performed instead of exposure using a photomask.

[0126] Thereafter, the above steps are repeated to form insulating paste layers, coil conductor layers, connecting conductor layers, and external conductor layers into a predetermined laminated structure. For example, the coil conductor layers formed here include a coil conductor layer that will later become the second coil wiring 21b.

[0127] When forming the coil conductor layer that will later become the second coil wiring 21b and the external conductor layer that is the same layer as the coil conductor layer, a lead-out conductor layer connected to the coil conductor layer and the external conductor layer is also formed. The lead-out conductor layer formed here will later become the second lead-out wiring 22b.

[0128] Finally, new insulating paste layers are formed by repeatedly applying an insulating paste containing a glass material, for example, whose main component is borosilicate glass, by screen printing, etc. The insulating paste layers formed here include insulating paste layers that will later become insulating layers 15c and 15d.

[0129] When forming the insulating paste layer, for example, a photomask having a groove pattern according to the inductor component of the present invention is used, thereby realizing the groove pattern according to the inductor component of the present invention in the inductor component 1A obtained later. For example, when forming the insulating paste layer that will later become the insulating layer 15b, a photomask having a groove pattern smaller than the development resolution limit of the photosensitive insulating paste is used, thereby forming grooves (grooves that do not reach complete resolution) that start at the interface between the internal conductor layer and the insulating paste layer that will later become the first internal wiring 25a and extend at an angle relative to the surface of the internal conductor layer. This allows the grooves 40 to be realized in the inductor component 1A obtained later, that start at the interface between the first internal wiring 25a and the insulating layer 15b and extend at an angle relative to the surface of the first internal wiring 25a.

[0130] The development resolution limit of the above-mentioned photosensitive insulating paste is, for example, 3 μm or less when irradiated with ultraviolet light having a light source wavelength of 365 / 405 nm.

[0131] In this way, a mother laminate is produced.

[0132] The method for forming the conductor patterns of the coil conductor layer, the lead-out conductor layer, the connection conductor layer, and the external conductor layer is not limited to the photolithography method described above, and may be, for example, a method in which a conductive paste is printed and laminated using a screen printing plate having openings in the shape of the conductor pattern, a method in which a conductor film is formed by a sputtering method, a vapor deposition method, a foil pressing method, or the like, and then the conductor film is etched to form the shape of the conductor pattern, or a method in which a negative pattern is formed by a semi-additive method, and then a plating film is formed, and then unnecessary portions of the plating film are removed by etching or the like to form the shape of the conductor pattern.

[0133] When forming the conductor patterns of the coil conductor layer, the lead conductor layer, the connection conductor layer, and the external conductor layer, forming the conductor patterns in multiple stages allows for a high aspect ratio, thereby reducing loss due to resistance at high frequencies. The method for forming the conductor patterns in multiple stages is not particularly limited, and may include, for example, a method of repeatedly overlapping conductor patterns by repeating steps using photolithography as described above, a method of repeatedly overlapping conductor patterns formed by a semi-additive method, a method of overlapping, in no particular order, a conductor pattern formed by a semi-additive method and a conductor pattern formed by etching a separately plated film, or a method of further plating a plated film formed by a semi-additive method.

[0134] The conductive material constituting the conductor patterns of the coil conductor layer, the lead-out conductor layer, the connection conductor layer, and the external conductor layer is not limited to the photosensitive conductive paste containing Ag or the like as the main metal component, but may also be a conductor containing a metal such as Ag, Au, or Cu formed by, for example, a sputtering method, a vapor deposition method, a foil pressing method, a plating method, or the like.

[0135] The method for forming the insulating paste layer is not limited to the photolithography method described above, and may be, for example, a method of pressing a sheet made of an insulating material, a method of spin-coating an insulating material, or a method of spray-coating an insulating material.

[0136] The method for forming the insulating paste layer having via holes and openings is not limited to the photolithography method described above, and may be, for example, a method in which an insulating film is formed by pressing a sheet made of an insulating material, spin coating an insulating material, spray coating an insulating material, or the like, and then the insulating film is subjected to laser processing, drilling, or the like to form via holes and openings.

[0137] The insulating material constituting the insulating paste layer is not limited to the glass material containing borosilicate glass as the main component, but may be, for example, a ceramic material, an organic material such as an epoxy resin, a fluororesin, or a polymer resin, a composite material such as a glass epoxy resin, etc. As the insulating material, a material with a small dielectric constant and dielectric loss is particularly preferable.

[0138] <Process for forming element body, coil, and external electrodes> First, the mother laminate is cut by dicing or the like to be separated into a plurality of unfired laminates.

[0139] The unsintered laminate has an insulating paste laminate portion formed by laminating insulating paste layers, a coil conductor laminate portion formed by laminating coil conductor layers so that adjacent coil conductor layers are electrically connected via connecting conductor layers, and an external conductor laminate portion formed by laminating external conductor layers.

[0140] When the green laminate is cut into individual pieces, the external conductor laminated portion is exposed at two locations on the bottom surface of at least the insulating paste laminated portion included in the cut surface of the green laminate.

[0141] Next, the unfired laminate is fired to produce a laminate.

[0142] When the green laminate is fired, the insulating paste layers become insulating layers, and the insulating paste laminate portion becomes the element body 10. When the green laminate is fired, the coil conductor layers become coil wiring, and the coil conductor laminate portion becomes the coil 20. When the green laminate is fired, one of the two external conductor laminate portions becomes part of the first external electrode 30a, and the other becomes part of the second external electrode 30b.

[0143] Next, the obtained laminate may be subjected to, for example, barrel polishing to round the corners and ridges of the element body 10.

[0144] Finally, using the two fired external conductor laminated portions as base electrodes, Ni-plated electrodes and Sn-plated electrodes are formed in this order on the surfaces of the respective base electrodes by plating. The thicknesses of the Ni-plated electrodes and Sn-plated electrodes are, for example, 2 μm or more and 10 μm or less.

[0145] In this way, the first external electrode 30a and the second external electrode 30b are formed, each having a base electrode, a Ni-plated electrode, and a Sn-plated electrode in this order from the surface side of the element body 10. In this case, in the first external electrode 30a, the base electrode may be integral with the surface of the element body 10 (in FIG. 1, the end face 11a and the bottom face 12b of the element body 10), and the Ni-plated electrode and the Sn-plated electrode may protrude from the surface of the element body 10 (in FIG. 1, the end face 11a and the bottom face 12b of the element body 10) so as to cover the base electrode. In addition, in the second external electrode 30b, the base electrode may be integral with the surface of the element body 10 (in FIG. 1, the end face 11b and the bottom face 12b of the element body 10), and the Ni-plated electrode and the Sn-plated electrode may protrude from the surface of the element body 10 (in FIG. 1, the end face 11b and the bottom face 12b of the element body 10) so as to cover the base electrode.

[0146] The method for forming the external electrode is not limited to the method of plating the external conductor laminate portion exposed on the cut surface (at least the bottom surface of the insulating paste laminate portion) of the unsintered laminate as described above, but may also be a method of exposing the external conductor laminate portion on the cut surface (at least the bottom surface of the insulating paste laminate portion) of the unsintered laminate as described above, and then immersing (dipping) the exposed portion of the external conductor laminate portion in a conductive paste, or forming a film of conductive paste on the exposed portion of the external conductor laminate portion by a sputtering method, and then plating the same.

[0147] In this way, the inductor component 1A is manufactured.

[0148] The inductor component 1A is manufactured to have, for example, a 0402 (0.4 mm×0.2 mm×0.2 mm) size. The size of the inductor component 1A is not limited to the 0402 (0.4 mm×0.2 mm×0.2 mm) size.

[0149] The groove pattern of the inductor component 1A may be realized by using a photomask having the groove pattern of the inductor component of the present invention when forming an insulating paste layer in the process of fabricating a mother laminate, as described above, or by other methods. For example, when firing an unfired laminate in the process of forming the element body, coil, and external electrodes, the gradient of the temperature drop profile may be increased to intentionally leave residual stress inside the resulting element body 10, and then a lightweight impact material may be collided with the element body 10 from a predetermined direction to form grooves 40 that start at the interface between the first internal wiring 25a and the insulating layer 15b and extend at an angle relative to the surface of the first internal wiring 25a. Alternatively, the groove pattern of the inductor component of the present invention may be formed by irradiating the insulating paste layer with a laser after it is formed.

[0150] [Embodiment 2] In the inductor component of the second embodiment of the present invention, when viewed in a cross section including the interface between the internal wiring and the insulating layer, where the starting point of the groove is located, the insulating layer is further provided with an additional groove that starts at the interface, extends along the surface of the internal wiring, and does not cross the groove. Except for this, the inductor component of the second embodiment of the present invention is similar to the inductor component of the first embodiment of the present invention.

[0151] FIG. 3 is a cross-sectional view showing an example of an inductor component according to a second embodiment of the present invention.

[0152] In the inductor component 1B shown in FIG. 3, in addition to the grooves 40, additional grooves 50 are further provided in the insulating layer 15b.

[0153] As shown in Figure 3, when viewed in a cross section including the interface between the first internal wiring 25a and the insulating layer 15b where the starting point of the groove 40 exists (in Figure 3, the outer edge of the first outgoing wiring 22a of the first internal wiring 25a), the additional groove 50 extends along the surface of the first internal wiring 25a from the interface as its starting point and does not cross the groove 40.

[0154] In this specification, when viewing a cross section including the interface between the internal wiring and the insulating layer where the groove starting point is located, the mode in which the additional groove starts at the interface between the internal wiring and the insulating layer and extends along the surface of the internal wiring means that the angle between the extension direction of the additional groove near the starting point and the direction along the surface of the internal wiring is less than 30°. For example, in inductor component 1B, the angle between the extension direction of additional groove 50 near the interface (starting point) between first internal wiring 25a and insulating layer 15b and the direction along the surface of first internal wiring 25a may be 7° or less, 0°, or a non-zero angle, as long as it is less than 30°. In other words, in inductor component 1B, the extension direction of additional groove 50 near the interface (starting point) between first internal wiring 25a and insulating layer 15b and the direction along the surface of first internal wiring 25a may or may not be strictly parallel.

[0155] In this specification, when viewed in a cross section including the interface between the internal wiring 25a and the insulating layer where the starting point of the groove is located, an aspect in which the additional groove does not cross the groove means an aspect in which the additional groove does not cross the starting point of the groove at the interface. For example, in the inductor component 1B, when viewed in a cross section including the interface between the first internal wiring 25a and the insulating layer 15b where the starting point of the groove 40 is located, one end of the additional groove 50 close to the starting point of the groove 40 (in FIG. 3, the end farther from the first external electrode 30a) may or may not be in contact with the starting point of the groove 40 (it may be separated).

[0156] In the inductor component 1B, the insulating layer 15b is provided with an additional groove 50 that starts at the interface between the first internal wiring 25a and the insulating layer 15b and extends along the surface of the first internal wiring 25a. Therefore, even if stress occurs at the interface between the first internal wiring 25a and the insulating layer 15b due to differences in the amounts of thermal contraction between the first internal wiring 25a and the insulating layer 15b during the manufacturing process of the inductor component 1B, the stress is not only released by the groove 40, but also released over a wider area by the additional groove 50. As a result, in the inductor component 1B, interfacial peeling between the first internal wiring 25a and the insulating layer 15b due to stress generated at the interface between the first internal wiring 25a and the insulating layer 15b is sufficiently suppressed, and as a result, the occurrence of cracks along the first internal wiring 25a inside the element body 10 is sufficiently suppressed.

[0157] Furthermore, in the inductor component 1B, the additional groove 50 extending along the surface of the first internal wiring 25a does not cross the groove 40, and therefore the additional groove 50 is blocked by the groove 40, which not only prevents the additional groove 50 from progressing, but also prevents a decrease in the strength of the base body 10 due to the progression of the additional groove 50.

[0158] In Fig. 3, of both ends of the additional groove 50, one end of the additional groove 50 (the end farther from the first external electrode 30a in Fig. 3) is closer to the starting point of the groove 40, but the other end of the additional groove 50 (the end closer to the first external electrode 30a in Fig. 3) may be closer to the starting point of the groove 40. Alternatively, in addition to the groove 40 whose starting point is close to one end of the additional groove 50 (the end farther from the first external electrode 30a in Fig. 3), another groove 40 whose starting point is close to the other end of the additional groove 50 (the end closer to the first external electrode 30a in Fig. 3) may be provided.

[0159] In Figure 3, when viewing a cross section including the interface between the first internal wiring 25a and the insulating layer 15b where the starting point of the groove 40 is located, the additional groove 50 starts at the interface between the first internal wiring 25a and the insulating layer 15b, extends along the surface of the first internal wiring 25a, and does not cross the groove 40. However, if the starting point of the groove 40 is located at the interface between the first internal wiring 25a and an insulating layer other than the insulating layer 15b (for example, the insulating layer 15a), when viewing a cross section including that interface, the additional groove 50 may start at the interface between the first internal wiring 25a and an insulating layer other than the insulating layer 15b (for example, the insulating layer 15a), extend along the surface of the first internal wiring 25a, and not cross the groove 40. Alternatively, if the starting point of the groove 40 is at the interface between an internal wiring other than the first internal wiring 25a (e.g., the second internal wiring 25b) and an insulating layer (e.g., the insulating layer 15c), when a cross section including the interface is viewed, the additional groove 50 may start from the interface between the internal wiring other than the first internal wiring 25a (e.g., the second internal wiring 25b) and the insulating layer (e.g., the insulating layer 15c), extend along the surface of the internal wiring other than the first internal wiring 25a (e.g., the second internal wiring 25b), and not cross the groove 40.

[0160] Thus, in inductor component 1B, when viewed in a cross section including the interface between internal wiring 25 where groove 40 starts and insulating layer (including insulating layer 15a, insulating layer 15b, insulating layer 15c, and insulating layer 15d), additional groove 50 extends along the surface of internal wiring 25 from the interface and does not cross groove 40.

[0161] As shown in Figure 3, when viewing a cross section including the interface between the first internal wiring 25a and the insulating layer 15b, where the starting point of the groove 40 is located, the additional groove 50 extends along the surface of the first internal wiring 25a from the interface and does not cross the groove 40. However, as shown in Figure 3, it is particularly preferable that when viewing a cross section including the interface between the first escape wiring 22a and the insulating layer 15b, where the starting point of the groove 40 is located, the additional groove 50 extends along the surface of the first escape wiring 22a from the interface and does not cross the groove 40.

[0162] The additional groove 50 may be straight, curved, or a combination of straight and curved shapes. In these cases, the additional groove 50 may be bent midway.

[0163] The position of the additional groove 50 relative to the internal wire 25 is not particularly limited as long as, when viewed in a cross section including the interface between the internal wire 25 and the insulating layer at which the starting point of the groove 40 exists, the additional groove 50 extends along the surface of the internal wire 25 from the interface and does not cross the groove 40. For example, when viewed from the coil axis direction, the additional groove 50 may be provided on the outer peripheral edge side of the internal wire 25 (in FIG. 3, the first lead wiring 22a of the first internal wire 25a), or on the inner peripheral edge side of the internal wire 25. Furthermore, when viewed from a direction orthogonal to the coil axis direction (here, a direction including the length direction L and the height direction T), the additional groove 50 may be provided on the side surface 13a side of the element body 10 (the front side of the paper in FIG. 3) or on the side surface 13b side of the element body 10 (the back side of the paper in FIG. 3) with respect to the surface of the internal wire 25.

[0164] When viewing a cross section including the interface between the internal wiring 25 and the insulating layer, where the starting point of the groove 40 exists, the additional groove 50 is not particularly limited in its extending direction, as long as it starts from the interface and extends along the surface of the internal wiring 25 without crossing the groove 40. For example, the additional groove 50 may extend in the coil axis direction, in a direction perpendicular to the coil axis direction, or in a direction other than these.

[0165] [Embodiment 3] In the inductor element of the third embodiment of the present invention, the width of the groove is larger on the internal wiring side relative to the direction in which the groove extends than on the opposite side from the internal wiring. Except for this, the inductor element of the third embodiment of the present invention is similar to the inductor element of the first embodiment of the present invention.

[0166] FIG. 4 is a cross-sectional view schematically illustrating an example of an inductor component according to a third embodiment of the present invention.

[0167] In the inductor component 1C shown in FIG. 4, the width of the groove 40 is greater on the first internal wiring 25a side in the direction in which the groove 40 extends than on the opposite side to the first internal wiring 25a.

[0168] In the inductor component 1C, the width of the groove 40 is larger on the first internal wiring 25a side than on the opposite side to the first internal wiring 25a in the direction in which the groove 40 extends, and therefore the width of the groove 40 is larger near the interface between the first internal wiring 25a and the insulating layer 15b, where stress caused by a difference in the amount of thermal contraction between the first internal wiring 25a and the insulating layer 15b is likely to concentrate (become large), and therefore the stress is more likely to be released by the groove 40. Furthermore, in the inductor component 1C, the width of the groove 40 is larger in a position close to the first internal wiring 25a but smaller in a position farther from the first internal wiring 25a, and therefore even with such grooves 40 provided, the strength of the element body 10 is less likely to decrease and sufficient strength is ensured.

[0169] The width of the groove 40 may gradually increase as it moves from the side opposite the first internal wiring 25a toward the first internal wiring 25a (as it approaches the first internal wiring 25a) in the direction in which the groove 40 extends, as shown in Fig. 4, or it may increase in steps. For example, the outer shape of the groove 40 may be tapered or stepped as shown in Fig. 4 so that the width is wider on the first internal wiring 25a side than on the side opposite the first internal wiring 25a.

[0170] In Figure 4, groove 40 is formed starting from the interface between the first internal wiring 25a and insulating layer 15b, but even if groove 40 is formed starting from the interface between the first internal wiring 25a and an insulating layer other than insulating layer 15b (e.g., insulating layer 15a), or if groove 40 is formed starting from the interface between an internal wiring other than the first internal wiring 25a (e.g., second internal wiring 25b) and an insulating layer (e.g., insulating layer 15c), the width of groove 40 may be larger on the internal wiring 25 side than on the opposite side of internal wiring 25 in the direction in which groove 40 extends.

[0171] [Embodiment 4] In the inductor element according to the fourth embodiment of the present invention, a plurality of grooves are provided in the insulating layer. Except for this, the inductor element according to the fourth embodiment of the present invention is similar to the inductor element according to the first embodiment of the present invention.

[0172] FIG. 5 is a cross-sectional view showing an example of an inductor component according to a fourth embodiment of the present invention.

[0173] In the inductor component 1D shown in FIG. 5, a plurality of grooves 40 are provided in the insulating layer 15b.

[0174] In the inductor component 1D, the provision of multiple grooves 40 allows for greater release of stress at the interface between the first internal wiring 25a and the insulating layer 15b than when only one groove 40 is provided, thereby further suppressing the occurrence of cracks inside the base body 10.

[0175] The number of the plurality of grooves 40 is not limited to three as shown in FIG. 5, but may be two, or may be four or more.

[0176] The shapes of the plurality of grooves 40 may be the same as or different from one another, or may be partially different. For example, the shape of the plurality of grooves 40 may be any combination selected from the group consisting of straight lines, curved lines, shapes that combine straight lines and curved lines, and shapes that are bent in the middle in these cases.

[0177] The positions of the multiple grooves 40 with respect to the internal wiring 25 may be the same as or different from one another, or may be partially different. For example, the positions of the multiple grooves 40 with respect to the internal wiring 25 may be any combination selected from the group consisting of the outer peripheral edge side of the internal wiring 25 (first internal wiring 25a in FIG. 5) when viewed from the coil axis direction, the inner peripheral edge side of the internal wiring 25 when viewed from the coil axis direction, the side surface 13a side of the element body 10 with respect to the surface of the internal wiring 25 when viewed from a direction perpendicular to the coil axis direction (the front side of the paper in FIG. 5), and the side surface 13b side of the element body 10 with respect to the surface of the internal wiring 25 when viewed from a direction perpendicular to the coil axis direction (the back side of the paper in FIG. 5).

[0178] The extending directions of the multiple grooves 40 may be the same as or different from one another, or may be partially different from one another. For example, the extending directions of the multiple grooves 40 may be any combination selected from the group consisting of the coil axis direction, a direction perpendicular to the coil axis direction, and other directions.

[0179] In the example shown in Figure 5, some (two in Figure 5) of the multiple grooves 40 are formed starting from the interface between the first escape wiring 22a and the insulating layer 15b, and the rest (one in Figure 5) are formed starting from the interface between the first coil wiring 21a and the insulating layer 15b, but all of the multiple grooves 40 may be formed starting from the interface between the first escape wiring 22a and the insulating layer 15b, or all may be formed starting from the interface between the first coil wiring 21a and the insulating layer 15b.

[0180] The maximum width of the plurality of grooves 40 is preferably 0.25 μm or less.

[0181] The maximum width of the plurality of grooves 40 is preferably 0.020 μm or more.

[0182] The maximum length of the plurality of grooves 40 is preferably 1.75 μm or less.

[0183] The maximum length of the plurality of grooves 40 is preferably 0.3 μm or more.

[0184] In the above-described embodiments 1, 2, 3, and 4, examples are shown in which the mounting surface of the element body is parallel to the coil axis direction, but in these embodiments, the mounting surface of the element body may also be perpendicular to the coil axis direction.

[0185] The present specification discloses the following:

[0186] <1> an element body including an insulating layer; an internal wiring provided inside the element body, at least a portion of which is electrically connected to form a spirally wound coil; an external electrode electrically connected to the coil, The inductor component is characterized in that the insulating layer is provided with a groove that starts at the interface between the internal wiring and the insulating layer and extends at an angle relative to the surface of the internal wiring.

[0187] <2> the external electrode includes a first external electrode electrically connected to one end of the coil; the internal wiring includes a first internal wiring connected to the first external electrode, The groove starts at the interface between the first internal wiring and the insulating layer and extends obliquely with respect to the surface of the first internal wiring. <1> The inductor component according to claim 1.

[0188] <3> the first internal wiring includes a first coil wiring that configures the coil, and a first lead-out wiring that connects the first coil wiring and the first external electrode, The groove starts at an interface between the first escape routing and the insulating layer and extends at an angle with respect to a surface of the first escape routing. <2> The inductor component according to claim 1.

[0189] <4> the insulating layer is further provided with an additional groove that starts at the interface, extends along the surface of the internal wiring, and does not cross the groove, when viewed in a cross section including the interface between the internal wiring and the insulating layer, where the starting point of the groove is present; <1> ~ <3> 10. The inductor component according to claim 9, wherein:

[0190] <5> The width of the groove is larger on the internal wiring side than on the opposite side to the internal wiring in the extending direction of the groove. <1> ~ <4> 10. The inductor component according to claim 9, wherein:

[0191] <6> The maximum width of the groove is 0.25 μm or less. <1> ~ <5> 10. The inductor component according to claim 9, wherein:

[0192] <7> The maximum length of the groove is 1.75 μm or less. <1> ~ <6> 10. The inductor component according to claim 9, wherein: [Explanation of symbols]

[0193] 1A, 1B, 1C, 1D inductor components 10 Base 11a, 11b End surfaces of element body 12a Top surface of the body 12b Bottom of the body 13a, 13b Side of the body 15a, 15b, 15c, 15d insulating layers 20 coils 21a First coil wiring 21b Second coil wiring 22a 1st lead out wiring 22b 2nd lead out wiring 25 Internal wiring 25a 1st internal wiring 25b 2nd internal wiring 30a 1st external electrode 30b 2nd external electrode 40 grooves 50 additional grooves C Coil shaft L lengthwise T Height direction W width direction

Claims

1. an element body including an insulating layer; an internal wiring provided inside the element body, the internal wiring being at least partially electrically connected to form a spirally wound coil; an external electrode electrically connected to the coil; a groove is provided in the insulating layer, the groove starting from an interface between the internal wiring and the insulating layer and extending at an angle with respect to a surface of the internal wiring; An inductor component characterized in that the groove is provided at least on the inner edge side of the internal wiring when viewed in a cross section including the insulating layer and the internal wiring perpendicular to the coil axis direction of the coil.

2. An element body including an insulating layer; an internal wiring provided inside the element body, the internal wiring being at least partially electrically connected to form a spirally wound coil; an external electrode electrically connected to the coil; a groove is provided in the insulating layer, the groove starting from an interface between the internal wiring and the insulating layer and extending at an angle with respect to a surface of the internal wiring; the insulating layer is further provided with an additional groove that, when viewed in a cross section including an interface between the insulating layer and the internal wiring at which the starting point of the groove exists, extends along a surface of the internal wiring from the interface and does not cross the groove; An inductor component, wherein the groove and the additional groove include at least a linear portion.

3. the external electrodes include a first external electrode electrically connected to one end of the coil; the internal wiring includes a first internal wiring connected to the first external electrode, 3. The inductor component according to claim 1, wherein the groove starts at an interface between the first internal wiring and the insulating layer and extends at an angle with respect to a surface of the first internal wiring.

4. the first internal wiring includes a first coil wiring that configures the coil, and a first lead wiring that connects the first coil wiring and the first external electrode, The inductor component according to claim 3 , wherein the groove starts at an interface between the first escape routing and the insulating layer and extends at an angle with respect to a surface of the first escape routing.

5. 2. The inductor component of claim 1, wherein the insulating layer further comprises an additional groove that extends along the surface of the internal wiring from the interface where the groove originates and does not cross the groove when viewed in a cross section including the interface between the internal wiring and the insulating layer where the groove originates.

6. 3. The inductor component according to claim 1, wherein the width of the groove is larger on the side of the internal wiring in the direction in which the groove extends than on the side opposite to the internal wiring.

7. 3. The inductor component according to claim 1, wherein the maximum width of the groove is 0.25 [mu]m or less.

8. 3. The inductor component according to claim 1, wherein the maximum length of the groove is 1.75 μm or less.

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