Inductor components

Abstract

To provide an inductor component that can reduce the stress at a border part between a coil wiring layer and an external electrode.SOLUTION: An inductor component 1 includes: an element assembly 10; a coil provided in the element assembly and wound in a spiral shape along an axis AX; and a first external electrode 30 and a second external electrode 40. The element assembly has: a first end surface 15 and a second end surface 16 facing each other; a first side surface and a second side surface, a bottom surface 17 connected between the end surfaces and between the side surfaces, and a top surface 18 facing the bottom surface. The coil with a shaft parallel to the bottom surface and intersecting with the first side surface and the second side surface has a plurality of coil wiring layers stacked along the shaft. The coil wiring layers each have a first coil wiring layer 51 connected to the first external electrode. When viewed from an axis direction, the first coil wiring layer includes a top surface part 510 facing the top surface, and a connection part 511 connected between the first external electrode and the top surface part. The connection part includes at least one curve line part of a first curve line part 511a, a second curve line part 511b, and a third curve line part 511c.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Conventionally, as an inductor component, there is one described in U.S. Patent No. 10923259 (Patent Document 1). This inductor component has a base body, a coil provided in the base body and wound spirally along an axis, and a first external electrode and a second external electrode provided on the base body and electrically connected to the coil. The coil has a plurality of coil wiring layers laminated along the axis, and the plurality of coil wiring layers have a first coil wiring layer connected to the first external electrode. When viewed from the axial direction, the first coil wiring layer has a top surface portion facing the top surface of the base body and a connection portion connected between the first external electrode and the top surface portion, and the connection portion is formed linearly.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, miniaturization of inductor components has been attempted, and in order to improve Q characteristics, an increase in the thickness of coil wiring layers has been attempted. In such a situation, the volume ratio of the coil wiring layer in the base body becomes large, and in the conventional inductor components as described above, it has been found that due to the difference in the thermal expansion coefficients of the base body and the coil wiring layer, the thermal stress applied to the connection portion of the coil wiring layer during firing or mounting becomes large. And because the thermal stress applied to the connection portion becomes large, it has been found that the stress at the boundary portion between the connection portion and the external electrode becomes large.

[0005] Therefore, the object of this disclosure is to provide an inductor component that can reduce stress at the boundary between the coil wiring layer and the external electrode. [Means for solving the problem]

[0006] To solve the aforementioned problems, an inductor component according to one aspect of this disclosure is provided. The base body and, A coil provided within the aforementioned body and wound spirally along an axis, A first external electrode and a second external electrode are provided on the base body and electrically connected to the coil. Equipped with, The body includes a first end face and a second end face that face each other, a first side surface and a second side surface that face each other, a bottom surface connected between the first end face and the second end face and between the first side surface and the second side surface, and a top surface facing the bottom surface. The shaft is parallel to the bottom surface and intersects the first side surface and the second side surface. The coil has a plurality of coil wiring layers stacked along the axis, and the plurality of coil wiring layers have a first coil wiring layer connected to the first external electrode. Viewed from the axial direction, the first coil wiring layer has a top surface portion facing the top surface and a connecting portion connected between the first external electrode and the top surface portion, and the connecting portion includes at least one curved portion.

[0007] According to the above embodiment, since the connection portion includes a curved portion, the stress on the connection portion can be reduced even if thermal stress is applied to the inductor component during firing or mounting. Furthermore, the stress on the connection portion can be reduced even if bending stress is applied to the inductor component during mounting. As a result, the stress at the boundary between the connection portion and the external electrode can be reduced.

[0008] An inductor component, which is one aspect of this disclosure, The base body and, A coil provided within the aforementioned body and wound spirally along an axis, A first external electrode and a second external electrode are provided on the base body and electrically connected to the coil. Equipped with, The body includes a first end face and a second end face that face each other, a first side surface and a second side surface that face each other, a bottom surface connected between the first end face and the second end face and between the first side surface and the second side surface, and a top surface facing the bottom surface. The shaft is parallel to the bottom surface and intersects the first side surface and the second side surface. The coil has a plurality of coil wiring layers stacked along the axis, and the plurality of coil wiring layers have a second coil wiring layer connected to the second external electrode. Viewed from the axial direction, the second coil wiring layer has a first external electrode facing portion that faces the first external electrode, and a connecting portion that is connected between the second external electrode and the first external electrode facing portion and faces the bottom surface, the connecting portion including at least one curved portion.

[0009] According to the above embodiment, since the connection portion includes a curved portion, the stress on the connection portion can be reduced even if thermal stress is applied to the inductor component during firing or mounting. Furthermore, the stress on the connection portion can be reduced even if bending stress is applied to the inductor component during mounting. As a result, the stress at the boundary between the connection portion and the external electrode can be reduced. [Effects of the Invention]

[0010] According to an inductor component in one aspect of this disclosure, it is possible to reduce stress at the boundary between the coil wiring layer and the external electrode. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing a first embodiment of an inductor component. [Figure 2] This is a perspective front view of the inductor component, seen from the first side. [Figure 3] This is a plan view of an exploded inductor component. [Figure 4] This is a front view of the first coil wiring layer as seen from the axial direction. [Figure 5] It is a front view seen from the axial direction of the second coil wiring layer. [Figure 6] It is a front view seen from the axial direction of the first coil wiring layer showing a second embodiment of the inductor component. [Figure 7] It is a front view seen from the axial direction of the first coil wiring layer showing a third embodiment of the inductor component. [Figure 8] It is a front view seen from the axial direction of the second coil wiring layer showing a fourth embodiment of the inductor component.

Mode for Carrying Out the Invention

[0012] Hereinafter, an inductor component which is an aspect of the present disclosure will be described in detail with reference to the illustrated embodiments. Note that the drawings include some schematic ones and may not reflect actual dimensions and ratios.

[0013] (First Embodiment) FIG. 1 is a perspective view showing a first embodiment of the inductor component. FIG. 2 is a perspective front view seen from the first side of the inductor component. FIG. 3 is an exploded plan view of the inductor component. As shown in FIGS. 1, 2, and 3, the inductor component 1 includes a body 10, a coil 20 provided in the body 10 and wound spirally along the axis AX, and a first external electrode 30 and a second external electrode 40 provided on the body 10 and electrically connected to the coil 20. For the sake of convenience, in FIG. 2, the body and the coil are drawn transparently so that the structure can be easily understood, but they may be semi-transparent or opaque.

[0014] The inductor component 1 is electrically connected to the wiring of a circuit board (not shown) via the first and second external electrodes 30 and 40. The inductor component 1 is used, for example, as a coil for impedance matching (matching coil) of a high-frequency circuit, and is used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, automotive electronics, and medical and industrial machines. However, the use of the inductor component 1 is not limited to this, and it can also be used, for example, in tuning circuits, filter circuits, rectifier smoothing circuits, etc.

[0015] The base body 10 is formed in a substantially rectangular parallelepiped shape. The surface of the base body 10 includes a first end face 15 and a second end face 16 that face each other, a first side face 13 and a second side face 14 that face each other, a bottom face 17 connected between the first end face 15 and the second end face 16 and between the first side face 13 and the second side face 14, and a top face 18 facing the bottom face 17. The bottom face 17 is the face facing the mounting substrate side when the inductor component 1 is mounted on a mounting substrate (not shown).

[0016] As shown in the figure, the X direction is orthogonal to the first end face 15 and the second end face 16, and is the direction from the first end face 15 toward the second end face 16. The Y direction is orthogonal to the first side face 13 and the second side face 14, and is the direction from the second side face 14 toward the first side face 13. The Z direction is orthogonal to the bottom face 17 and the top face 18, and is the direction from the bottom face 17 toward the top face 18. The X direction is also referred to as the length direction of the base body 10, the Y direction is also referred to as the width direction of the base body 10, and the Z direction is also referred to as the height direction of the base body 10. The X direction, the Y direction, and the Z direction are directions orthogonal to each other, and when arranged in the order of X, Y, Z, they form a left-handed system.

[0017] The base body 10 is formed by laminating a plurality of insulating layers 11. The insulating layer 11 is made of, for example, a material mainly composed of borosilicate glass, or a material such as ferrite or resin. The lamination direction of the insulating layers 11 is a direction (Y direction) parallel to the first and second end faces 15, 16 and the bottom face 17 of the base body 10. That is, the insulating layer 11 is in a layer shape spreading in the XZ plane. In the present application, the “parallel” is not limited to a strict parallel relationship, and also includes a substantial parallel relationship considering the range of actual variations. Note that in the case of the base body 10, the interfaces between the plurality of insulating layers 11 may not be clear due to firing or the like. In FIG. 3, the direction from top to bottom is taken as the lamination direction (Y direction).

[0018] The first external electrode 30 and the second external electrode 40 are made of a conductive material such as Ag, Cu, Au, or alloys mainly composed of these materials. The first external electrode 30 has an L-shape formed from the first end face 15 to the bottom face 17. The first external electrode 30 is embedded in the base body 10 so as to be exposed from the first end face 15 and the bottom face 17. The first external electrode 30 consists of a first end face portion 31 extending along the first end face 15 and a first bottom face portion 32 connected to the first end face portion 31 and extending along the bottom face 17.

[0019] The second external electrode 40 is L-shaped and extends from the second end face 16 to the bottom face 17. The second external electrode 40 is embedded in the base body 10 so as to be exposed from the second end face 16 and the bottom face 17. The second external electrode 40 consists of a second end face portion 41 that extends along the second end face 16 and a second bottom face portion 42 that is connected to the second end face portion 41 and extends along the bottom face 17.

[0020] The first external electrode 30 has a structure in which a plurality of first external electrode conductor layers 33 embedded in the base body 10 (insulating layer 11) are stacked. The second external electrode 40 has a structure in which a plurality of second external electrode conductor layers 43 embedded in the base body 10 (insulating layer 11) are stacked. The first external electrode conductor layer 33 extends along the first end face 15 and the bottom face 17, and the second external electrode conductor layer 43 extends along the second end face 16 and the bottom face 17.

[0021] This allows the first and second external electrodes 30 and 40 to be embedded within the base body 10, thus enabling miniaturization of the inductor component compared to a configuration where the external electrodes are attached externally to the base body 10. Furthermore, the coil 20 and the external electrodes 30 and 40 can be formed in the same process, and by reducing variations in the positional relationship between the coil 20 and the external electrodes 30 and 40, variations in the electrical characteristics of the inductor component 1 can be reduced.

[0022] As shown in Figure 2, the coil 20 is made of the same conductive material as the first and second external electrodes 30 and 40. The coil 20 is wound spirally along the lamination direction of the insulating layer 11. The first end of the coil 20 is connected to the first external electrode 30, and the second end of the coil 20 is connected to the second external electrode 40. In this embodiment, the coil 20 and the first and second external electrodes 30 and 40 are integrated and there is no clear boundary between them, but this is not limited to this, and a boundary may exist if the coil and the external electrodes are formed from different materials or using different manufacturing methods.

[0023] The coil 20 is wound along axis AX such that axis AX is parallel to the bottom surface 17 and axis AX intersects the first side surface 13 and the second side surface 14. The axis AX of the coil 20 coincides with the lamination direction (Y direction) of the insulating layer 11. The axis AX of the coil 20 represents the central axis of the helical shape of the coil 20.

[0024] The coil 20 has a winding portion 20a, a first lead portion 20b connected between the first end of the winding portion 20a and the first external electrode 30, and a second lead portion 20c connected between the second end of the winding portion 20a and the second external electrode 40. In this embodiment, the winding portion 20a and the first and second lead portions 20b, 20c are integrated and there is no clear boundary between them, but this is not limited to this, and a boundary may exist if the winding portion and the lead portions are formed from different materials or using different manufacturing methods.

[0025] The winding section 20a is wound spirally along the axis AX. In other words, the winding section 20a refers to the spirally wound portion where the coils 20 overlap each other when viewed from a direction parallel to the axis AX. The first and second lead-out sections 20b and 20c refer to the portions that are separated from the overlapping section.

[0026] When viewed from the axis AX of coil 20, the shape of coil 20 is symmetrical with respect to a straight line passing through the axis AX of coil 20 and parallel to the Z direction. This suppresses variations in the characteristics of inductor component 1.

[0027] As shown in Figure 3, the coil 20 has a plurality of coil wiring layers 51 to 53 stacked along axis AX, and a plurality of via wiring layers 61 and 62 located between adjacent coil wiring layers in the direction of axis AX and connecting adjacent coil wiring layers in the direction of axis AX. The plurality of coil wiring layers 51 to 53 are each provided in the insulating layer 11, and the plurality of via wiring layers 61 and 62 are each provided in the insulating layer 11.

[0028] Multiple coil wiring layers 51-53 are each wound along a plane and electrically connected in series to form a helix. Each of the multiple coil wiring layers 51-53 is formed by winding on the main surface (XZ plane) of the insulating layer 11 perpendicular to the axis AX direction (Y direction). The number of turns for each coil wiring layer 51-53 is less than one turn, but may be one turn or more.

[0029] Multiple via wiring layers 61 and 62 penetrate the insulating layer 11 in the thickness direction (Y direction). Adjacent coil wiring layers in the stacking direction are electrically connected in series via the via wiring layers. In this way, the multiple coil wiring layers 51 to 53 are electrically connected in series to each other, forming a helix.

[0030] Specifically, the first coil wiring layer 51, the third coil wiring layer 53, and the second coil wiring layer 52 are stacked in order along the Y direction. The end of the first coil wiring layer 51 is connected to the first external electrode conductor layer 33 of the first external electrode 30. The end of the second coil wiring layer 52 is connected to the second external electrode conductor layer 43 of the second external electrode 40.

[0031] The first via layer 61 is located between the first coil layer 51 and the third coil layer 53, connecting the end of the first coil layer 51 to the end of the third coil layer 53. The second via layer 62 is located between the third coil layer 53 and the second coil layer 52, connecting the end of the third coil layer 53 to the end of the second coil layer 52.

[0032] Figure 4 is a front view of the first coil wiring layer 51 as seen from the direction of axis AX. As shown in Figure 4, as seen from the direction of axis AX, the first coil wiring layer 51 is connected to the first end face portion 31 of the first external electrode 30. The first coil wiring layer 51 has a top surface portion 510 facing the top surface 18 and a connecting portion 511 connected between the first external electrode 30 (first end face portion 31) and the top surface portion 510. The connecting portion 511 includes at least one curved portion 511a, 511b, 511c. A curved portion corresponds to, for example, a circular arc.

[0033] According to the above configuration, since the connection portion 511 includes curved portions 511a, 511b, and 511c, the stress on the connection portion 511 can be reduced even if thermal stress is applied to the inductor component 1 during firing or mounting. Furthermore, the stress on the connection portion 511 can be reduced even if bending stress is applied to the inductor component 1 during mounting. This reduces the stress at the boundary between the connection portion 511 and the first external electrode 30. For example, the occurrence of cracks at the boundary between the connection portion 511 and the first external electrode 30 can be prevented.

[0034] As shown in Figure 4, when viewed from the direction of axis AX, the top surface 510 includes a straight section parallel to the top surface 18. In this embodiment, the top surface 510 is formed in a straight line consisting only of the straight section. This makes it easier to manufacture the top surface 510 and suppresses variations in the inductor component 1.

[0035] Viewed from the axial AX direction, the connection portion 511 has, in order from the top surface portion 510 toward the first external electrode 30, a first curved portion 511a that is convex radially outward of the coil 20, a straight portion 511d parallel to the first end face 15, a second curved portion 511b that is convex radially outward of the coil 20, and a third curved portion 511c that is convex radially inward of the coil 20. The first curved portion 511a is connected to the top surface portion 510. The third curved portion 511c is connected to the first end face portion 31 of the first external electrode 30. The boundaries between the first curved portion 511a, the second curved portion 511b, the third curved portion 511c, and the straight portion 511d are shown by dotted lines in Figure 4. According to the above configuration, the connection portion 511 includes a first curved portion 511a, a second curved portion 511b, and a third curved portion 511c. Therefore, even if thermal stress or bending stress is applied to the inductor component 1 during mounting, the stress on the connection portion 511 can be reduced. The number of curved portions 511a, 511b, 511c, and straight portion 511d may be increased or decreased.

[0036] As shown in Figure 4, preferably, the length of all straight sections 511d is 40% or less of the length of all curved sections 511a, 511b, and 511c. Here, the length of the straight sections 511d and the lengths of the curved sections 511a, 511b, and 511c refer to the magnitude in the direction of extension of the centerline of the connection section 511, respectively. The centerline is shown by the dashed line in Figure 4. With the above configuration, even if thermal stress or bending stress is applied to the inductor component 1, the stress on the connection section 511 can be further reduced because the ratio of the straight sections 511d is small. As a result, the stress at the boundary between the connection section 511 and the first external electrode 30 can be further reduced.

[0037] As shown in Figure 4, when viewed from the direction of axis AX, the first curved portion 511a connected to the top surface portion 510 is convex radially outward of the coil. With this configuration, the area of ​​the inner diameter of the coil 20 increases at the first curved portion 511a connected to the top surface portion 510. In other words, the inner diameter of the coil 20 increases at the corners of the coil 20. This improves the inductance characteristics and Q characteristics.

[0038] As shown in Figure 4, viewed from the direction of axis AX, the connection portion 511 includes a straight portion 511d and at least one curved portion between the straight portion 511d and the first external electrode 30. Specifically, the connection portion 511 includes a second curved portion 511b and a third curved portion 511c between the straight portion 511d and the first external electrode 30. This configuration allows for a reduction in the stress on the connection portion 511 because the curved portion is located near the first external electrode 30, which is prone to thermal and bending stresses. Preferably, the straight portion 511d faces the first end face 15. This arrangement allows the inner diameter of the coil 20 to be increased and the inductance to be improved. Preferably, at least one curved portion between the straight portion 511d and the first external electrode 30 is convex radially inward of the coil 20. Specifically, the third curved portion 511c is convex radially inward of the coil 20. This allows the third curved portion 511c to be separated from the first end face 15, thereby further reducing the stress on the connection portion 511. Preferably, at least one curved section between the straight section 511d and the first external electrode 30 is directly connected to the first external electrode 30. Specifically, the third curved section 511c is directly connected to the first external electrode 30. This allows the stress on the connection section 511 to be further reduced because the third curved section 511c is separated from the first end face 15.

[0039] Figure 5 is a front view of the second coil wiring layer 52 as seen from the axial AX direction. As shown in Figure 5, as seen from the axial AX direction, the second coil wiring layer 52 is connected to the second end face portion 41 of the second external electrode 40. The second coil wiring layer 52 has a top surface portion 520 facing the top surface 18 and a connecting portion 521 connected between the second external electrode 40 (second end face portion 41) and the top surface portion 520. The connecting portion 521 includes at least one curved portion 521a, 521b, 521c. A curved portion corresponds to, for example, a circular arc.

[0040] According to the above configuration, since the connection portion 521 includes curved portions 521a, 521b, and 521c, the stress on the connection portion 521 can be reduced even if thermal stress is applied to the inductor component 1 during firing or mounting. Furthermore, the stress on the connection portion 521 can be reduced even if bending stress is applied to the inductor component 1 during mounting. This reduces the stress at the boundary between the connection portion 521 and the second external electrode 40. For example, the occurrence of cracks at the boundary between the connection portion 521 and the second external electrode 40 can be prevented.

[0041] As shown in Figure 5, when viewed from the direction of axis AX, the top surface 520 includes a straight section parallel to the top surface 18. In this embodiment, the top surface 520 is formed in a straight line consisting only of the straight section. This makes it easier to manufacture the top surface 520 and suppresses variations in the inductor component 1.

[0042] Viewed from the axial AX direction, the connection portion 521 has, in order from the top surface portion 520 toward the second external electrode 40, a first curved portion 521a that is convex radially outward of the coil 20, a straight portion 521d parallel to the first end face 15, a second curved portion 521b that is convex radially outward of the coil 20, and a third curved portion 521c that is convex radially inward of the coil 20. The first curved portion 521a is connected to the top surface portion 520. The third curved portion 521c is connected to the second end face portion 41 of the second external electrode 40. The boundaries between the first curved portion 521a, the second curved portion 521b, the third curved portion 521c, and the straight portion 521d are shown by dotted lines in Figure 5. According to the above configuration, the connection portion 521 includes a first curved portion 521a, a second curved portion 521b, and a third curved portion 521c. Therefore, even if thermal stress or bending stress is applied to the inductor component 1 during mounting, the stress on the connection portion 521 can be reduced. The number of curved portions 521a, 521b, 521c, and straight portion 521d may be increased or decreased.

[0043] As shown in Figure 5, preferably, the length of all straight sections 521d is 40% or less of the length of all curved sections 521a, 521b, and 521c. Here, the length of the straight sections 521d and the lengths of the curved sections 521a, 521b, and 521c refer to the magnitude in the direction of extension of the centerline of the connection section 521, respectively. The centerline is shown by the dashed line in Figure 5. With the above configuration, even if thermal stress or bending stress is applied to the inductor component 1, the stress on the connection section 521 can be further reduced because the ratio of the straight sections 521d is small. As a result, the stress at the boundary between the connection section 521 and the second external electrode 40 can be further reduced.

[0044] As shown in Figure 5, when viewed from the direction of axis AX, the first curved portion 521a connected to the top surface portion 520 is convex radially outward of the coil. With this configuration, the area of ​​the inner diameter of the coil 20 increases at the first curved portion 521a connected to the top surface portion 520. In other words, the inner diameter of the coil 20 increases at the corners of the coil 20. This improves the inductance characteristics and Q characteristics.

[0045] As shown in Figure 5, viewed from the direction of axis AX, the connection portion 521 includes a straight portion 521d and at least one curved portion between the straight portion 521d and the second external electrode 40. Specifically, the connection portion 521 includes a second curved portion 521b and a third curved portion 521c between the straight portion 521d and the second external electrode 40. This configuration allows for a reduction in the stress on the connection portion 521 because the curved portion is located near the second external electrode 40, which is prone to thermal and bending stresses. Preferably, the straight portion 521d faces the second end face 16. This arrangement allows the inner diameter of the coil 20 to be increased and the inductance to be improved. Preferably, at least one curved portion between the straight portion 521d and the second external electrode 40 is convex radially inward of the coil 20. Specifically, the third curved portion 521c is convex radially inward of the coil 20. This allows the third curved portion 521c to be separated from the second end face 16, thereby further reducing the stress on the connection portion 521. Preferably, at least one curved section between the straight section 521d and the second external electrode 40 is directly connected to the second external electrode 40. Specifically, the third curved section 521c is directly connected to the second external electrode 40. This allows the third curved section 521c to be separated from the second end face 16, thereby further reducing the stress on the connection section 521.

[0046] Next, we will explain the manufacturing method of the inductor component 1.

[0047] As shown in Figure 3, the inductor component 1 is manufactured by alternately stacking the first to third coil wiring layers 51-53 and the first and second via wiring layers 61 and 62 together with the insulating layer 11, starting from top to bottom in the figure. The coil wiring layers 51-53 are provided on the insulating layer 11, for example by screen printing. The via wiring layers 61 and 62 are provided on the insulating layer 11 by creating openings, for example by photolithography or laser printing, and then providing the vias at these openings, for example by screen printing.

[0048] (Second Embodiment) Figure 6 is a front view of the first coil wiring layer as seen from the axial direction, showing a second embodiment of the inductor component. The second embodiment differs from the first embodiment in the shape of the connection portion of the first coil wiring layer of the coil. This differing configuration will be described below. Other configurations are the same as in the first embodiment, and are denoted by the same reference numerals as in the first embodiment, and their descriptions will be omitted.

[0049] As shown in Figure 6, in the coil 20A of the inductor component 1A of the second embodiment, the connection portion 511A of the first coil wiring layer 51A is formed in a curved shape when viewed from the direction of axis AX. Curved shape means that it does not include a straight section and is composed of at least one curved section. With the above configuration, even if thermal stress or bending stress is applied to the inductor component 1A, the stress on the connection portion 511A can be further reduced because the connection portion 511A does not include a straight section. As a result, the stress at the boundary between the connection portion 511A and the first external electrode 30 can be further reduced.

[0050] Preferably, the connecting portion 511A is composed of at least four curved portions. Specifically, viewed from the direction of axis AX, the connecting portion 511A has, in order from the top surface portion 510 toward the first external electrode 30, a first curved portion 511a that is convex radially outward of the coil 20A, a second curved portion 511b that is convex radially inward of the coil 20A, a third curved portion 511c that is convex radially outward of the coil 20A, and a fourth curved portion 511d that is convex radially inward of the coil 20A. The first curved portion 511a is connected to the top surface portion 510. The fourth curved portion 511d is connected to the first external electrode 30.

[0051] With the above configuration, since the connection portion 511A is formed in a meandering shape, even if thermal stress or bending stress is applied to the inductor component 1A, the stress on the connection portion 511A can be further reduced. In addition, the degree of freedom in winding the coil 20A is increased, enabling a design with higher Q characteristics. The number of curved sections in the connection portion may also be increased.

[0052] Although not shown in the diagram, preferably, the connection portion 521 of the second coil wiring layer 52 (see Figure 5) may also be formed in a curved shape when viewed from the direction of axis AX. This allows for a reduction in stress on the connection portion because the connection portion does not contain any straight sections, even when thermal stress or bending stress is applied to the inductor component. This further reduces the stress at the boundary between the connection portion and the second external electrode 40.

[0053] Preferably, the connection portion 521 (see Figure 5) of the second coil wiring layer 52 may be composed of at least four curved sections. This allows the connection portion to be formed in a meandering shape, thereby reducing the stress on the connection portion even when thermal stress or bending stress is applied to the inductor component. Furthermore, it increases the degree of freedom in the coil winding method, enabling a design with higher Q characteristics.

[0054] (Third embodiment) Figure 7 is a front view of the first coil wiring layer as seen from the axial direction, showing a third embodiment of the inductor component. The third embodiment differs from the first embodiment in the shape of the connection portion of the first coil wiring layer of the coil. This differing configuration is described below. Other configurations are the same as in the first embodiment, and are denoted by the same reference numerals as in the first embodiment, and their descriptions are omitted.

[0055] As shown in Figure 7, in the coil 20B of the inductor component 1B of the third embodiment, the third curved portion 511c of the first coil wiring layer 51B is connected to the first bottom surface portion 32 of the first external electrode 30 when viewed from the axial AX direction. The third curved portion 511c is convex radially inward of the coil 20B. The third curved portion 511c corresponds to an example of the "second curved portion" described in the claims. The first curved portion 511a, the second curved portion 511b, and the straight portion 511d of the first coil wiring layer 51B have the same configuration as the first curved portion 511a, the second curved portion 511b, and the straight portion 511d of the first coil wiring layer 51 described in the first embodiment.

[0056] According to the above configuration, the third curved portion 511c connected to the first bottom portion 32 is convex radially inward of the coil 20B, so the third curved portion 511c can be positioned away from the first end portion 31 as shown by arrow A. This makes it possible to suppress the generation of stray capacitance between the third curved portion 511c and the first end portion 31.

[0057] Furthermore, since the third curved section 511c can be positioned away from the first end face section 31, the space between the third curved section 511c and the first end face section 31 becomes wider, as shown by arrow A. As a result, when the coil wiring layer and external electrodes are manufactured by photolithography, the flow of the developer improves, and the developability is enhanced.

[0058] Although not shown in the diagram, preferably, similarly, when viewed from the direction of axis AX, the third curved portion 521c (see Figure 5) of the second coil wiring layer 52 is connected to the second bottom surface portion 42 of the second external electrode 40. The third curved portion 521c is convex radially inward of the coil.

[0059] According to the above configuration, the third curved section connected to the second bottom section 42 is convex radially inward of the coil, so the third curved section can be positioned away from the second end section 41. This suppresses the generation of stray capacitance between the third curved section and the second end section 41.

[0060] Furthermore, since the third curved section can be positioned away from the second end face section 41, the space between the third curved section and the second end face section 41 becomes wider. As a result, when the coil wiring layer and external electrodes are manufactured by photolithography, the flow of the developer solution improves, and the developability is enhanced.

[0061] (Fourth Embodiment) Figure 8 is a front view of the second coil wiring layer as seen from the axial direction, showing a fourth embodiment of the inductor component. The fourth embodiment differs from the first embodiment in the shape of the second coil wiring layer of the coil. This differing configuration will be described below. Other configurations are the same as in the first embodiment, and are denoted by the same reference numerals as in the first embodiment, and their descriptions will be omitted.

[0062] As shown in Figure 8, in the coil 20C of the inductor component 1C of the fourth embodiment, the second coil wiring layer 52C is connected to the second external electrode 40. Viewed from the axial direction AX, the second coil wiring layer 52C has a first external electrode facing portion 523 that faces the first external electrode 30, and a connecting portion 521C that is connected between the second external electrode 40 and the first external electrode facing portion 523. The connecting portion 521C faces the bottom surface 17. The connecting portion 521C includes at least one curved portion 521a, 521b, 521c.

[0063] According to the above configuration, since the connection portion 521C includes curved portions 521a, 521b, and 521c, the stress on the connection portion 521C can be reduced even if thermal stress is applied to the inductor component 1C during firing or mounting. Furthermore, the stress on the connection portion 521C can be reduced even if bending stress is applied to the inductor component 1C during mounting. This reduces the stress at the boundary between the connection portion 521C and the second external electrode 40. For example, the occurrence of cracks at the boundary between the connection portion 521C and the second external electrode 40 can be prevented.

[0064] As shown in Figure 8, viewed from the direction of axis AX, the connection portion 521C has, in order from the first external electrode opposing portion 523 toward the second external electrode 40, a first curved portion 521a that is convex radially outward of the coil 20C, a straight portion 521d parallel to the bottom surface 17, a second curved portion 521b that is convex radially outward of the coil 20C, and a third curved portion 521c that is convex radially inward of the coil 20C. The first curved portion 521a is connected to the first external electrode opposing portion 523. The third curved portion 521c is connected to the second bottom surface portion 42 of the second external electrode 40. With the above configuration, since the connection portion 521C includes the first curved portion 521a, the second curved portion 521b, and the third curved portion 521c, even if thermal stress or bending stress is applied to the inductor component 1C during mounting, the stress on the connection portion 521C can be reduced. The number of curved sections 521a, 521b, 521c and straight sections 521d may be increased or decreased.

[0065] Preferably, as in the first embodiment, the length of all straight sections 521d is 40% or less of the length of all curved sections 521a, 521b, and 521c. With the above configuration, even if thermal stress or bending stress is applied to the inductor component 1C, the stress on the connection section 521C can be further reduced because the proportion of straight sections 521d is small. As a result, the stress at the boundary between the connection section 521C and the second external electrode 40 can be further reduced.

[0066] Although not shown, preferably, as viewed from the axial AX direction, the first coil wiring layer connected to the first external electrode 30 has a second external electrode facing portion that faces the second external electrode 40, and a connecting portion that connects the first external electrode 30 and the second external electrode facing portion. The connecting portion faces the bottom surface 17. The connecting portion includes at least one curved portion.

[0067] According to the above configuration, since the connection portion includes a curved section, the stress on the connection portion can be reduced even if thermal stress is applied to the inductor component during firing or mounting. Furthermore, the stress on the connection portion can be reduced even if bending stress is applied to the inductor component during mounting. As a result, the stress at the boundary between the connection portion and the first external electrode 30 can be reduced. For example, the occurrence of cracks at the boundary between the connection portion and the first external electrode 30 can be prevented.

[0068] This disclosure is not limited to the embodiments described above, and design modifications are possible without departing from the gist of this disclosure. For example, the features of each of the first to fourth embodiments may be combined in various ways. The number of coil wiring layers may be increased or decreased, and the number of via wiring layers may also be increased or decreased. Furthermore, the top surface and connection portion of the coil wiring layer may include straight sections or be formed in a curved shape.

[0069] In the above embodiment, the first external electrode and the second external electrode are L-shaped electrodes composed of an end face portion and a bottom face portion, respectively, but they may also be bottom electrodes composed of a bottom face portion.

[0070] This disclosure includes the following aspects. <1> The base body and, A coil provided within the aforementioned body and wound spirally along an axis, A first external electrode and a second external electrode are provided on the base body and electrically connected to the coil. Equipped with, The body includes a first end face and a second end face that face each other, a first side surface and a second side surface that face each other, a bottom surface connected between the first end face and the second end face and between the first side surface and the second side surface, and a top surface facing the bottom surface. The shaft is parallel to the bottom surface and intersects the first side surface and the second side surface. The coil has a plurality of coil wiring layers stacked along the axis, and the plurality of coil wiring layers have a first coil wiring layer connected to the first external electrode. Viewed from the axial direction, the first coil wiring layer has a top surface portion facing the top surface and a connecting portion connected between the first external electrode and the top surface portion, and the connecting portion includes at least one curved portion, an inductor component. <2> The base body and, A coil provided within the aforementioned body and wound spirally along an axis, A first external electrode and a second external electrode are provided on the base body and electrically connected to the coil. Equipped with, The body includes a first end face and a second end face that face each other, a first side surface and a second side surface that face each other, a bottom surface connected between the first end face and the second end face and between the first side surface and the second side surface, and a top surface facing the bottom surface. The shaft is parallel to the bottom surface and intersects the first side surface and the second side surface. The coil has a plurality of coil wiring layers stacked along the axis, and the plurality of coil wiring layers have a second coil wiring layer connected to the second external electrode. Inductor component, as viewed from the axial direction, the second coil wiring layer has a first external electrode facing portion that faces the first external electrode, and a connecting portion connected between the second external electrode and the first external electrode facing portion and facing the bottom surface, wherein the connecting portion includes at least one curved portion. <3> Viewed from the axial direction, the connecting portion includes a straight section, and the total length of all the straight sections is 40% or less of the total length of all the curved sections. <1> or <2> The inductor components listed below. <4> Viewed from the axial direction, the at least one curved portion includes a first curved portion connected to the top surface, and the first curved portion is convex radially outward of the coil. <1> The inductor components listed below. <5> Viewed from the axial direction, the connecting portion is formed in a curved shape. <1> or <2> The inductor components listed below. <6> Viewed from the axial direction, the connecting portion is composed of at least four curved portions. <5> The inductor components listed below. <7> The first external electrode is composed of a first end face portion extending along the first end face and a first bottom face portion connected to the first end face portion and extending along the bottom face. Viewed from the axial direction, the at least one curved portion includes a second curved portion connected to the first bottom portion, and the second curved portion is convex radially inward of the coil. <1> or <4> The inductor components listed below. <8> Viewed from the axial direction, the connecting portion includes a straight portion, and includes at least one curved portion between the straight portion and the first external electrode. <1> The inductor components listed below. <9> The straight portion is facing the first end face, <8> The inductor components listed below. <10> The at least one curved portion between the straight portion and the first external electrode is convex radially inward of the coil. <9> The inductor components listed below. <11> The at least one curved portion between the straight portion and the first external electrode is directly connected to the first external electrode. <10> The inductor components listed below. [Explanation of Symbols]

[0071] 1, 1A, 1B, 1C inductor components 10 Base Body 11 Insulating layer 13 First aspect 14 Second aspect 15 First end surface 16 Second end face 17. Bottom 18 Top surface 20, 20A, 20B, 20C coils 20a Winding section 20b 1st drawer 20c 2nd drawer 30 1st external electrode 31 First end section 32 1st bottom part 33 First outer electrode conductor layer 40 2nd external electrode 41 Second end section 42 2nd bottom part 43. Second external electrode conductor layer 51, 51A, 51B First coil wiring layer 52, 52C Second coil wiring layer 53 Third coil wiring layer 61, 62 First and second via wiring layers 510, 520 Top section 511, 511A, 511B, 521, 521C connection section 511a, 521a 1st curve section 511b, 521b 2nd curve section 511c, 521c 3rd curve section 511d, 521d Straight section 511e 4th curve section 523 First external electrode opposing part AX axis

Claims

1. The base body and, A coil provided within the aforementioned body and wound spirally along an axis, A first external electrode and a second external electrode are provided on the aforementioned body and electrically connected to the coil. Equipped with, The body includes a first end face and a second end face that face each other, a first side surface and a second side surface that face each other, a bottom surface connected between the first end face and the second end face and between the first side surface and the second side surface, and a top surface facing the bottom surface. The shaft is parallel to the bottom surface and intersects the first side surface and the second side surface. The coil has a plurality of coil wiring layers stacked along the axis, and the plurality of coil wiring layers have a first coil wiring layer connected to the first external electrode. Viewed from the axial direction, the first coil wiring layer has a top surface portion facing the top surface and a connecting portion that deviates from the spiral winding pattern of the coil and connects the first external electrode to the top surface portion. Viewed from the axial direction, the connecting portion is composed of at least four curved portions formed in a meandering manner. Inductor components.

2. The inductor component according to claim 1, wherein, viewed from the axial direction, the connecting portion includes a straight portion.

3. The inductor component according to claim 1, wherein, viewed from the axial direction, the at least one curved portion includes a first curved portion connected to the top surface, and the first curved portion is convex radially outward of the coil.

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