Multilayer inductor

Abstract

To provide a multilayer inductor in which a Q value is improved.SOLUTION: In a multilayer inductor 1, both extension directions of connection parts 37 and 37 become a direction along turning parts 31 to 36 in view of a Z direction, and more concretely, a direction slightly inclined from the turning parts 31 to 36. According to such as connection parts 37 and 38, the change of a current route in a bonding portion of the turning parts 31 to 36 becomes smooth. In the case where the current route in the bonding portion is rapidly changed (e.g., at 90 degrees), it is considered that a large signal loss occurs in the bonding portion. In such a case, the deterioration of a Q value is caused. In the multilayer inductor 1, since the current route in the bonding portion of the turning parts 31 to 36 and the connection parts 37 and 38 is generally changed, and a signal loss in the bonding portion is suppressed, a high Q value can be realized.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a stacked inductor.

Background Art

[0002] Patent Document 1 below discloses a stacked inductor provided with a coil conductor having a coil axis parallel to the mounting surface of the body. In the stacked inductor disclosed in this document, the body is composed of a plurality of insulator layers stacked along the extending direction of the coil axis, and the coil conductor is composed of a plurality of inductor conductor layers stacked through the insulator layers and via hole conductors penetrating the insulator layers.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the stacked inductor according to the above-described prior art, since the plurality of insulator layers are stacked along the extending direction of the coil axis, the length of the via hole conductor intervening between adjacent inductor conductor layers is limited to the thickness of the insulator layer, and its direction is limited to the thickness direction of the insulator layer (i.e., the extending direction of the coil axis). Therefore, it is difficult to adjust the interval between adjacent inductor conductor layers, and the degree of freedom in designing the number of coil turns is low, so it is difficult to adjust (for example, increase) the inductance value.

[0005] Therefore, the inventors can adjust the interval between adjacent inductor conductor layers by forming the body with an insulating layer parallel to the coil axis, thereby adjusting the inductance value. neatWe conducted extensive research on the technology to achieve this. As a result of this research, we found that, as with the conventional multilayer inductor mentioned above, when viewed from a direction perpendicular to the mounting surface, if the current path bends 90 degrees at the junction between the inductor conductor layer and the via hole conductor, the current path changes abruptly, causing signal loss at that junction and potentially leading to a decrease in the Q factor.

[0006] The present invention aims to provide a multilayer inductor with improved Q value. [Means for solving the problem]

[0007] A laminated inductor according to one embodiment of the present invention comprises a base body having a laminated structure in which a plurality of insulating layers are stacked, a mounting surface parallel to the insulating layers, a pair of terminal electrodes provided on the mounting surface of the base body, and a coil conductor provided inside the base body, having a coil axis parallel to the mounting surface, with both ends exposed from the mounting surface and electrically connected to the pair of terminal electrodes, wherein the coil conductor includes an outer coil portion wound on the outer circumference side and an inner coil portion wound on the inner circumference side when viewed from the extending direction of the coil axis, and the outer coil portion and the inner coil portion are wound alternately in the coil conductor However, it has multiple stages of turns arranged along the coil axis, and at least some of the stages of turns are located in a plane perpendicular to the coil axis and include a first coil portion that constitutes part of the outer coil portion and a second coil portion that constitutes part of the inner coil portion, and the ends of the first coil portions and the ends of the second coil portions of adjacent stages of turns are offset in a direction parallel to the mounting surface when viewed from the extending direction of the coil axis, and the coil conductor further has connecting portions that extend linearly between the ends of the first coil portions or between the ends of the second coil portions of adjacent stages of turns and connect each other.

[0008] In the above-described multilayer inductor, the extension direction of the connection portion is not parallel to the coil axis, but rather along the direction of the turn portion. Therefore, the current path at the junction between the turn portion and the connection portion changes gradually, thereby suppressing signal loss at the junction and improving the Q value.

[0009] In other forms of multilayer inductors, the coil conductor has three or more turns, and has multiple connection points that connect the ends of the first coil sections or the ends of the second coil sections of adjacent turns.

[0010] In other forms of laminated inductors, the amount of misalignment at both ends of the connection portion with respect to the direction of extension of the coil axis is 1 to 3 times the length of the turn portion.

[0011] In other forms of multilayer inductors, both ends of the coil conductor extend from the outer coil portion and reach the mounting surface. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a multilayer inductor with improved Q value. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic perspective view showing a multilayer inductor according to one embodiment. [Figure 2] Figure 1 is a side view of the coil conductor as seen from the X direction. [Figure 3] Figure 1 is a plan view showing the coil conductor. [Figure 4] Figure 1 is a side view of the coil conductor as seen from the Y direction. [Figure 5] This is an exploded perspective view showing the turned sections that make up the coil conductor. [Figure 6] This is a perspective exploded view showing the connections of the turn sections in a coil conductor. [Figure 7] This is a perspective exploded view showing the connections of the turn sections in a coil conductor. [Figure 8] This is a perspective exploded view showing the connections of the turn sections in a coil conductor. [Figure 9] This is a perspective exploded view showing the connections of the turn sections in a coil conductor. [Figure 10]It is a perspective exploded view showing the connection of the turn portions in the coil conductor. [Figure 11] It is a diagram showing the conductor pattern of the insulating layer in which the connection portion is formed. [Figure 12] It is a diagram showing the conductor pattern of the insulating layer in which the connection portion is formed. [Figure 13] It is a side view showing different forms of the coil conductor.

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant descriptions are omitted.

[0015] FIG. 1 shows a multilayer inductor 1 according to an embodiment. The multilayer inductor 1 includes a base body 10, a pair of terminal electrodes 20A and 20B provided on the surface of the base body 10, and a coil conductor 30 provided inside the base body 10.

[0016] The base body 10 has a substantially rectangular parallelepiped outer shape. The base body 10 has an upper surface 10a, a lower surface 10b, a pair of side surfaces 10c and 10d facing each other, and a pair of side surfaces 10e and 10f facing each other. In this embodiment, the lower surface 10b of the base body 10 is a mounting surface facing the mounting substrate on which the multilayer inductor 1 is mounted. In this embodiment, the separation distance between the side surfaces 10c and 10d is longer than the separation distance between the side surfaces 10e and 10f, and the base body 10 has a shape extending in the facing direction of the side surfaces 10c and 10d. Hereinafter, for convenience of explanation, the facing direction between the upper surface 10a and the lower surface 10b is also referred to as the Z direction, the facing direction of the side surfaces 10c and 10d is also referred to as the Y direction, and the facing direction of the side surfaces 10e and 10f is also referred to as the X direction.

[0017] The base body 10 has a laminated structure in which multiple insulating layers 12 overlap in the Z direction. The planar shape of each insulating layer 12 (i.e., the shape when viewed from the Z direction) is the same as the shape of the top surface 10a and bottom surface 10b of the base body 10 (i.e., rectangular). The insulating layers 12 are made of insulating material, and are made of resin as an example. The number of insulating layers 12 is, for example, 9 to 20 layers (12 layers as an example). The thickness of the insulating layers 12 is, for example, 0.05 to 0.4 mm (0.3 mm as an example), and all insulating layers 12 constituting the base body 10 may be of the same thickness, or some insulating layers 12 may be of different thicknesses.

[0018] A pair of terminal electrodes 20A and 20B are provided on the lower surface 10b of the base body 10. Both terminal electrodes 20A and 20B have a rectangular shape, with one terminal electrode 20A extending along the short side corresponding to the side surface 10c on the lower surface 10b, and the other terminal electrode 20B extending along the short side corresponding to the side surface 10d on the lower surface 10b. Each terminal electrode 20A and 20B may have a single-layer structure or a multi-layer structure.

[0019] The coil conductor 30 is wound around a coil axis C that extends in the X direction. That is, the coil axis C of the coil conductor 30 is parallel to the upper surface 10a and the lower surface 10b of the base body 10, and is also parallel to a pair of side surfaces 10c and 10d. As shown in Figure 2, the coil conductor 30 has a double-winding structure and is composed of an outer coil portion 40 wound on the outer circumference side when viewed from the direction of extension of the coil axis C and an inner coil portion 50 wound on the inner circumference side. The coil conductor 30 is an assembly of conductors embedded in each insulating layer 12 that constitutes the base body 10. Therefore, the portion of the coil conductor 30 that extends in the Z direction (outer pillar, inner pillar, etc., described later) is composed of multiple overlapping conductors embedded in each of the multiple insulating layers 12.

[0020] As shown in Figures 3 and 4, the coil conductor 30 is composed of multiple stages (six stages in this embodiment) of turned sections 31 to 36 arranged along the coil axis C. Each turned section 31 to 36 is wound around the coil axis C in a plane perpendicular to the coil axis C (XY plane), and adjacent turned sections 31 to 36 are parallel to each other. As shown in Figure 5, the turned sections 31 to 36 are arranged in the order of turned section 31, turned section 32, turned section 33, turned section 34, turned section 35, and turned section 36, starting from the side surface 10e. The turned section 31 closest to the side surface 10e has a coil end 30a that constitutes one end of the coil conductor 30, and the turned section 36 furthest from the side surface 10e has a coil end 30 that constitutes the other end of the coil conductor 30. b The base body 10 has a configuration in which multiple insulating layers 12 are stacked in the Z direction perpendicular to the coil axis C, so the conductor pattern provided on the insulating layer 12 has a high degree of design freedom, and the various dimensions of the turn sections 31 to 36 can be precisely set. For example, the thickness (length in the X direction) of the turn section and the distance between adjacent turn sections can be set arbitrarily. In addition, the insulating of the base body 10 layer Without changing the number of layers (12), the number of steps in the turning section can be increased or decreased as needed.

[0021] Adjacent turn sections 31-36 are connected by connecting sections 37 and 38. The connection of turn sections 31-36 via connecting sections 37 and 38 will be explained below with reference to Figures 6-12.

[0022] Figure 6 shows the connection between the turn section 31 and the turn section 32 via the connecting section 37.

[0023] The turn section 31 has a first coil section 41 that constitutes part of the outer circumferential coil section 40, and a second coil section 51 that extends continuously from the first coil section 41 and constitutes part of the inner circumferential coil section 50. The first coil section 41 includes a pair of outer pillars 41a that extend in the Z direction and are spaced apart in the Y direction, and a pair of outer crossbars 41b that extend in the Y direction and are spaced apart in the Z direction, and constitutes one turn of the outer circumferential coil. The lower end of the outer pillar 41a located on the side surface 10c of the base body 10 constitutes the coil end 30a, extends to the lower surface 10b, is exposed from the lower surface 10b, and is physically and electrically connected to the terminal electrode 20A. The second coil section 51 includes a pair of inner pillars 51a that extend in the Z direction and are spaced apart in the Y direction, and a single inner crossbar 51b that extends in the Y direction, and constitutes three-quarters of an inner circumferential coil.

[0024] The turn section 32 has a first coil section 42 that constitutes a part of the outer circumferential coil section 40, and a second coil section 52 that extends continuously from the first coil section 42 and constitutes a part of the inner circumferential coil section 50. The first coil section 42 includes one outer pillar 42a extending in the Z direction and one outer crossbar 42b extending in the Y direction, and constitutes a 1 / 2 turn of the outer circumferential coil. The second coil section 52 includes a pair of inner pillars 52a extending in the Z direction and spaced apart in the Y direction, and one inner crossbar 52b extending in the Y direction, and constitutes a 3 / 4 turn of the inner circumferential coil.

[0025] The connecting portion 37 has a linear shape. The connecting portion 37 connects the second coil portion 51 of the turn portion 31 and the second coil portion 52 of the turn portion 32, which are parts that make up the inner circumferential coil portion 50. More specifically, the connecting portion 37 extends linearly between the lower end of the inner pillar 51a located on the side 10d side of the pair of inner pillars 51a of the second coil portion 51 and the lower end of the inner pillar 52a located on the side 10c side of the pair of inner pillars 52a of the second coil portion 52, connecting them to each other. Since the height position of the lower ends (i.e., position with respect to the Z direction) of the inner pillars 51a and 52a to which the connecting portion 37 is connected is the same, the connecting portion 37 extends perpendicular to the Z direction (i.e., parallel to the lower surface 10b). The inner pillars 51a and 52a to which the connection portion 37 is connected are offset in the Y direction when viewed from the extending direction of the coil axis C. Therefore, the connection portion 37 does not extend parallel to the X direction, but rather extends intersecting the X direction. More specifically, as shown in Figure 11, when viewed from the Z direction, the connection portion 37 extends in a direction inclined by a small angle θ1 (for example, θ1 < 45 degrees) from the Y direction. The amount of offset of the connection portion 37 with respect to the extending direction of the coil axis C is 1 to 3 times (2 times in this embodiment) the length of the turn portions 31 and 32 with respect to the extending direction of the coil axis C. Since the base body 10 has a configuration in which multiple insulating layers 12 are stacked in the Z direction perpendicular to the coil axis C, the conductor pattern provided on the insulating layer 12 has a high degree of design freedom, and various dimensions, including the angle θ1 of the connection portion 37, can be precisely set.

[0026] Figure 7 shows the connection between the turn section 32 and the turn section 33 via the connecting section 38.

[0027] The turn section 33 has a first coil section 43 that constitutes a part of the outer circumferential coil section 40, and a second coil section 53 that extends continuously from the first coil section 43 and constitutes a part of the inner circumferential coil section 50. The first coil section 43 includes a pair of outer pillars 43a that extend in the Z direction and are spaced apart in the Y direction, and an outer crossbar 43b that extends in the Y direction, and constitutes a 3 / 4 turn of the outer circumferential coil. The second coil section 53 includes an inner pillar 53a that extends in the Z direction and an inner crossbar 53b that extends in the Y direction, and constitutes a 1 / 2 turn of the inner circumferential coil.

[0028] The connecting portion 38, like the connecting portion 37, has a linear shape. The connecting portion 38 connects the first coil portion 42 of the turn portion 32 and the first coil portion 43 of the turn portion 33, which are parts that constitute the outer circumferential coil portion 40. More specifically, the connecting portion 38 extends linearly between the upper end of the outer pillar 42a of the first coil portion 42 and the upper end of the outer pillar 43a of the pair of outer pillars 43a of the first coil portion 43, which is located on the side 10d side, connecting them to each other. Since the upper ends of the outer pillars 42a and 43a to which the connecting portion 38 is connected are at the same height, the connecting portion 38 extends perpendicular to the Z direction. Since the outer pillars 42a and 43a to which the connecting portion 38 is connected are offset in the Y direction when viewed from the extending direction of the coil axis C, the connecting portion 38 does not extend parallel to the X direction, but extends intersecting the X direction. More specifically, as shown in Figure 12, when viewed from the Z direction, the connecting portion 38 extends in a direction inclined by a small angle θ2 (for example, θ2 < 45 degrees) from the Y direction. The amount of displacement of the connecting portion 38 with respect to the extending direction of the coil shaft C is 1 to 3 times (2 times in this embodiment) the length of the turn portions 32 and 33 with respect to the extending direction of the coil shaft C. Various dimensions of the connecting portion 38, including the angle θ2, can be precisely set, similar to the connecting portion 37.

[0029] Figure 8 shows the connection between the turn section 33 and the turn section 34 via the connecting section 37. The turn section 34 has substantially the same shape as the turn section 32 described above. That is, the turn section 34 has a first coil section 44 that constitutes part of the outer circumferential coil section 40, and a second coil section 54 that extends continuously from the first coil section 44 and constitutes part of the inner circumferential coil section 50. The first coil section 44 includes one outer pillar 44a extending in the Z direction and one outer crossbar 44b extending in the Y direction, and constitutes a 1 / 2 turn of the outer circumferential coil. The second coil section 54 includes a pair of inner pillars 54a that extend in the Z direction and are spaced apart in the Y direction, and one inner crossbar 54b extending in the Y direction, and constitutes a 3 / 4 turn of the inner circumferential coil. The connecting section 37 that connects the turn section 33 and the turn section 34 has the same shape and dimensions as the connecting section 37 that connects the turn section 31 and the turn section 32. The connecting portion 37 that connects the turn portion 33 and the turn portion 34 connects the second coil portion 53 of the turn portion 33 and the second coil portion 54 of the turn portion 34, which are parts that constitute the inner circumference coil portion 50. The configuration in which the connecting portion 37 that connects the turn portion 33 and the turn portion 34 connects the second coil portion 53 and the second coil portion 54 is the same as the configuration in which the connecting portion 37 that connects the turn portion 31 and the turn portion 32 connects the second coil portion 51 and the second coil portion 52.

[0030] Figure 9 shows the connection between the turn section 34 and the turn section 35 via the connecting section 38. The turn section 35 has substantially the same shape as the turn section 33 described above. That is, the turn section 35 has a first coil section 45 that constitutes part of the outer circumferential coil section 40, and a second coil section 55 that extends continuously from the first coil section 45 and constitutes part of the inner circumferential coil section 50. The first coil section 45 includes a pair of outer pillars 45a that extend in the Z direction and are spaced apart in the Y direction, and an outer crossbar 45b that extends in the Y direction, and constitutes a 3 / 4 turn of the outer circumferential coil. The second coil section 55 includes an inner pillar 55a that extends in the Z direction and an inner crossbar 55b that extends in the Y direction, and constitutes a 1 / 2 turn of the inner circumferential coil. The connecting section 38 that connects the turn section 34 and the turn section 35 has the same shape and dimensions as the connecting section 38 that connects the turn section 32 and the turn section 33. The connecting portion 38 that connects the turn portion 34 and the turn portion 35 connects the first coil portion 44 of the turn portion 34 and the first coil portion 45 of the turn portion 35, which are parts that constitute the outer circumferential coil portion 40. The configuration in which the connecting portion 38 that connects the turn portion 34 and the turn portion 35 connects the first coil portion 44 and the first coil portion 45 is the same as the configuration in which the connecting portion 38 that connects the turn portion 32 and the turn portion 33 connects the first coil portion 42 and the first coil portion 43.

[0031] Figure 10 shows the connection between the turn section 35 and the turn section 36 via the connecting section 37. The turn section 36 has a first coil section 46 that constitutes part of the outer circumferential coil section 40, and does not have a portion that constitutes the inner circumferential coil section 50. The first coil section 46 includes a pair of outer pillars 46a that extend in the Z direction and are spaced apart in the Y direction, and a single outer crossbar 46b that extends in the Y direction, and constitutes a 3 / 4 turn outer coil. The lower end of the outer pillar 46a located on the side 10d of the base body 10 constitutes the coil end 30b, extending down to the bottom surface 10b, being exposed from the bottom surface 10b, and is physically and electrically connected to the terminal electrode 20B.

[0032] The connecting portion 37 that connects the turn portion 35 and the turn portion 36 has a linear shape and connects the second coil portion 55 of the turn portion 35, which constitutes the inner circumferential coil portion 50, and the first coil portion 46 of the turn portion 36, which constitutes the outer circumferential coil portion 40. More specifically, the connecting portion 37 extends linearly between the lower end of the inner pillar 55a located on the side 10d side of the pair of inner pillars 55a of the second coil portion 55 and the lower end of the outer pillar 46a located on the side 10c side of the pair of outer pillars 46a of the first coil portion 46, connecting them to each other. Since the lower ends of the inner pillar 55a and the outer pillar 46a to which the connecting portion 37 is connected are at the same height, the connecting portion 37 extends perpendicular to the Z direction. The inner pillar 55a and the outer pillar 46a to which the connecting portion 37 is connected are offset in the Y direction when viewed from the extending direction of the coil axis C. Therefore, the connecting portion 37 does not extend parallel to the X direction, but rather extends intersecting the X direction. More specifically, as shown in Figure 11, when viewed from the Z direction, the connecting portion 37 extends in a direction inclined by a small angle θ3 (for example, θ3 < 45 degrees) from the Y direction. The amount of offset of the connecting portion 37 with respect to the extending direction of the coil axis C is 1 to 3 times (2 times in this embodiment) the length of the turn portions 35 and 36 with respect to the extending direction of the coil axis C.

[0033] The coil conductor 30 is constructed by connecting the turn portions 31-36 with the connection portions 37 and 38 as described above. The coil conductor 30 is constructed by alternately winding the outer coil portion 40 and the inner coil portion 50 using the turn portions 31-36 and the connection portions 37 and 38. Therefore, when a voltage is applied to the pair of terminal electrodes 20A and 20B, and current flows from, for example, one coil end 30a to the coil conductor 30, the current flows spirally around the coil axis C and alternately through the outer coil portion 40 and the inner coil portion 50.

[0034] In the multilayer inductor 1 described above, the extension direction of the connection portions 37, 37 is along the direction of the turn portions 31-36 when viewed from the Z direction, more specifically, slightly inclined from the turn portions 31-36. With such connection portions 37, 38, the change in the current path at the junction with the turn portions 31-36 becomes gradual. If the current path at the junction changes abruptly (for example, by 90 degrees), a large signal loss may occur at the junction, which can lead to a decrease in the Q value. In the multilayer inductor 1, the current path at the junction between the turn portions 31-36 and the connection portions 37, 38 changes gently, and signal loss at the junction is suppressed, thus enabling a high Q value to be achieved.

[0035] The coil conductor 30 of the multilayer inductor 1 has two connection portions 37 and two connection portions 38, and the connection portions 37 and 38 are arranged alternately in the direction of extension of the coil axis C. In other words, in the coil conductor 30, the connection of inner coil portions by connection portions 37 (i.e., the connection of the ends of the second coil portion) and the connection of outer coil portions by connection portions 38 (i.e., the connection of the ends of the first coil portion) are alternately repeated in the direction of extension of the coil axis C. The coil conductor 30 of the multilayer inductor 1 has both ends 30a and 30b drawn out from first coil portions 41 and 46 which constitute part of the outer coil portion 40. By having both ends of the coil conductor 30 composed of the outer coil portion 40 in this way, the inner diameter of the coil is increased, and the range of obtainable inductance can be expanded to the maximum extent.

[0036] The coil conductor 30 of the multilayer inductor 1 has six stages of turns 31 to 36, but the number of stages of turns can be increased or decreased as appropriate, and the coil conductor 30 only needs to have at least two stages of turns. When the coil conductor 30 has three stages of turns, the coil conductor 30 has two connection parts (i.e., connection part 37 and connection part 38). When the coil conductor 30 has four or more stages of turns, it has three or more connection parts 37 and 38, and the connection parts 37 and connection parts 38 are arranged alternately in the direction of extension of the coil axis C.

[0037] The coil conductor 30 of the multilayer inductor 1 described above has a double-winding structure. By making the coil conductor 30 a double-winding structure, a higher inductance can be obtained compared to a single-winding structure. The coil conductor 30 is not limited to a double-winding structure, but may also be a coil conductor with a multi-winding structure of three or more windings. Figure 13 shows a coil conductor 30A having a triple-winding structure. The coil conductor 30A is composed of an outer coil portion 40 wound on the outer circumference side and an inner coil portion 50 wound on the inner circumference side when viewed from the extending direction of the coil axis C, as well as an intermediate coil portion 60 wound between the outer coil portion 40 and the inner coil portion 50. The multiple stages of turns constituting the coil conductor 30A are connected to each other by a connecting portion 37, and the outer coil portions are connected to each other by a connecting portion 38, similar to the turns 31 to 36 of the coil conductor 30 described above.

[0038] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, it is not necessary for all turn portions constituting the coil conductor to include both a first coil portion that constitutes part of the outer coil portion and a second coil portion that constitutes part of the inner coil portion; it is sufficient if at least some of the turn portions include both. [Explanation of Symbols]

[0039] 1...Multilayer inductor, 10...Base body, 20A, 20B...Terminal electrodes, 30, 30A...Coil conductors, 31~36...Turn section, 37, 38...Connection section, 40...Outer coil section, 50...Inner coil section, C...Coil shaft.

Claims

1. A base body having a laminated structure in which multiple insulating layers are stacked, and having a mounting surface parallel to the insulating layers, A pair of terminal electrodes provided on the mounting surface of the aforementioned base body, A coil conductor is provided within the aforementioned body, having a coil axis parallel to the mounting surface, with both ends exposed from the mounting surface and electrically connected to the pair of terminal electrodes. Equipped with, The coil conductor is The coil conductor includes an outer coil portion wound on the outer circumference and an inner coil portion wound on the inner circumference when viewed from the extending direction of the coil shaft, and the outer coil portion and the inner coil portion are wound alternately in the coil conductor. The coil conductor has a plurality of turned sections arranged along the coil axis, and includes a first coil section in which at least some of the turned sections are located in a plane perpendicular to the coil axis and constitute a part of the outer coil section, and a second coil section which constitutes a part of the inner coil section and is continuous with the first coil section. The coil conductor further has connecting portions that extend linearly between the ends of the first coil portion or between the ends of the second coil portion of the turn portion of adjacent stages, connecting them to each other. In the turn portion of adjacent stages, the ends of the first coil portion or the ends of the second coil portion connected by the connecting portion are offset in a direction parallel to the mounting surface when viewed from the extending direction of the coil axis. The coil conductor has three or more turns, The connection portion includes a first connection portion that connects the ends of the first coil portion of the turn portion of adjacent stages that are farther from the mounting surface, and a second connection portion that connects the ends of the second coil portion of the turn portion of adjacent stages that are closer to the mounting surface. A multilayer inductor in which each of the ends of the coil conductor extends from the end of the outer coil portion closest to the mounting surface and reaches the mounting surface.

2. The laminated inductor according to claim 1, wherein, with respect to the extending direction of the coil shaft, the amount of displacement at both ends of the connection portion is 1 to 3 times the width of the turn portion.

Images