Inductor

Abstract

This provides an inductor that allows for easy adjustment of low inductance values. [Solution] In the inductor 1, the first internal conductor 40 extends along the first direction, which is the direction in which the base portion 31 of the substrate 30 extends, and is not wound. Therefore, the inductor 1 can achieve a lower inductance value compared to a wound internal conductor. In addition, since the first conductor portion 41 and the second conductor portion 42 of the first internal conductor 40 are formed on the substrate 30 using, for example, electroplating, their thickness (length in the thickness direction of the substrate 30) can be designed without restriction, thereby allowing the inductance value to be freely adjusted.

Description

Technical Field

[0001] The present invention relates to an inductor.

Background Art

[0002] Conventionally, as one type of inductor, an inductor in which an internal conductor is configured by a linear conductor has been known. Patent Document 1 below discloses an inductor including a linear conductive layer as an internal conductor between layers of an element body having a laminated structure composed of a plurality of magnetic layers. Such an inductor can easily achieve a low inductance value (low L value) compared to an inductor in which an internal conductor is configured by a wound conductor as disclosed in Citation Document 2.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors have repeatedly studied the structure of inductors having a low L value, and newly found a technique that can be easily adjusted to a desired low L value.

[0005] One aspect of the present invention aims to provide an inductor whose low L value can be easily adjusted.

Means for Solving the Problems

[0006] An inductor according to one aspect of the present invention comprises a base body, a substrate provided within the base body having a first main surface and a second main surface parallel to each other and a base portion extending along a first direction, a first internal conductor formed within the base body on at least one of the first main surface and the second main surface of the base portion of the substrate, and a pair of external electrodes provided on the surface of the base body and connected to both ends of the first internal conductor, wherein the first internal conductor extends along the first direction when viewed from a second direction perpendicular to the first main surface of the substrate.

[0007] In the above-described inductor, the first internal conductor extends along the first direction and is not wound, thus achieving a lower inductance value compared to a wound internal conductor. Furthermore, since the first internal conductor is formed on a substrate, its thickness (length in the second direction) can be designed without restriction, thereby allowing for flexible adjustment of the inductance value. [Effects of the Invention]

[0008] According to various aspects of the present invention, an inductor that allows for easy adjustment of low L values ​​is provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing an inductor according to one embodiment. [Figure 2] This is a cross-sectional view showing the inductor in Figure 1. [Figure 3] Figure 1 is a perspective view showing the substrate and the first inner conductor located inside the inductor. [Figure 4] This is a plan view showing the substrate placed inside the inductor shown in Figure 1. [Figure 5] Figure 3 is a plan view showing (a) the first main surface side and (b) the second main surface side of the substrate shown. [Figure 6] These are plan views showing (a) the first main surface side and (b) the second main surface side of substrates relating to different configurations. [Figure 7] This is a cross-sectional view showing the configuration of Figure 6. [Figure 8] It is a plan view showing (a) the first main surface side and (b) the second main surface side of a substrate according to a different embodiment. [Figure 9] It is a cross-sectional view showing the embodiment of Figure 8. [Figure 10] It is a plan view showing (a) the first main surface side and (b) the second main surface side of a substrate according to a different embodiment. [Figure 11] It is a cross-sectional view showing the embodiment of Figure 10. [Figure 12] It is a plan view showing (a) the first main surface side and (b) the second main surface side of a substrate according to a different embodiment. [Figure 13] It is a cross-sectional view showing the embodiment of Figure 12. [Figure 14] It is a plan view showing (a) the first main surface side and (b) the second main surface side of a substrate according to a different embodiment. [Figure 15] It is a cross-sectional view showing the embodiment of Figure 14. [Figure 16] It is a plan view showing (a) the first main surface side and (b) the second main surface side of a substrate according to a different embodiment. [Figure 17] It is a cross-sectional view showing the embodiment of Figure 16. [Figure 18] It is a cross-sectional view showing inductors of different embodiments. [Figure 19] It is (a) a table and (b) a graph showing simulation results. [Figure 20] It is a perspective view showing inductors of different embodiments. [Figure 21] It is a plan view showing a substrate provided inside the element body of the inductor of Figure 20. [Figure 22] It is a plan view showing the first main surface side of the substrate shown in Figures 20 and 21. [Figure 23] It is a plan view showing the second main surface side of the substrate shown in Figures 20 and 21. [Figure 24] It is a perspective view showing inductors of different embodiments. [Figure 25] It is a plan view showing a substrate provided inside the element body of the inductor of Figure 24. [Figure 26]Figures 24 and 25 are plan views showing the first main surface of the substrate. [Figure 27] Figures 24 and 25 are plan views showing the second main surface of the substrate. [Modes for carrying out the invention]

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

[0011] The inductor according to this embodiment will be described with reference to Figure 1. As shown in Figures 1 and 2, the inductor 1 according to one embodiment comprises a base body 10, a pair of terminal electrodes 20A and 20B (external electrodes), a substrate 30, and a first internal conductor 40.

[0012] The base body 10 has a rectangular parallelepiped shape and has a pair of parallel main surfaces 10a and 10b, and four side surfaces 10c, 10d, 10e, and 10f connecting the pair of main surfaces 10a and 10b. The rectangular parallelepiped shape as used herein includes the shape of a rectangular parallelepiped with chamfered corners and edges, and the shape of a rectangular parallelepiped with rounded corners and edges. One of the pair of main surfaces 10a and 10b is the surface facing the mounting substrate on which the inductor 1 is mounted, and will be referred to as the mounting surface in the following description. Each main surface 10a and 10b has a rectangular shape with a long side and a short side, and in the following description, the side surfaces 10c and 10d connecting the short sides of the main surfaces 10a and 10b will also be referred to as the end faces.

[0013] The base body 10 is composed of a magnetic powder-containing resin, which is a type of magnetic material. The magnetic powder-containing resin is a bound powder in which magnetic powder, described later, is bound by a binder resin. The binder resin is, for example, a thermosetting epoxy resin. In this embodiment, the magnetic powder content in the bound powder is 75 to 92 vol% by volume and 95 to 99 wt% by mass. From the viewpoint of magnetic properties, the magnetic powder content in the bound powder may be 80 to 92 vol% by volume and 97 to 99 wt% by mass.

[0014] The pair of terminal electrodes 20A and 20B are L-shaped electrodes that continuously cover the respective end faces 10c and 10d of the base body 10 and the mounting surface 10b. Terminal electrode 20A includes an end face covering portion 21 that covers a part of the end face 10c of the base body and a mounting surface covering portion 22 that covers a part of the mounting surface 10b on the end face 10c side, and the end face covering portion 21 and the mounting surface covering portion 22 form an L-shaped cross section. Similarly, terminal electrode 20B also includes an end face covering portion 21 that covers a part of the end face 10d of the base body and a mounting surface covering portion 22 that covers a part of the mounting surface 10b on the end face 10d side, and the end face covering portion 21 and the mounting surface covering portion 22 form an L-shaped cross section.

[0015] The mounting surface 10b of the base body 10 is entirely covered by the covering material 12. That is, the entire area of ​​the main surface 10b covered by the covering material 12 is not exposed to the outside. The mounting surface 10b in the area between the mounting surface covering portions 22 of the pair of terminal electrodes 20A and 20B is also covered by the covering material 12. The covering material 12 is interposed between the entire mounting surface covering portions 22 of the terminal electrodes 20A and 20B and the mounting surface 10b. That is, the mounting surface covering portions 22 of the terminal electrodes 20A and 20B are covered on the covering material 12. The covering material 12 is made of an insulating material such as epoxy resin or acrylic resin, and the covering material 12 prevents short circuits between the pair of terminal electrodes 20A and 20B.

[0016] The main surface 10a of the base body 10 is entirely covered by the covering material 14. That is, the entire area of ​​the main surface 10a covered by the covering material 14 is not exposed to the outside. The covering material 14 is made of an insulating material such as epoxy resin or acrylic resin. The constituent materials of the covering material 14 that covers the main surface 10a may be the same as or different from the constituent materials of the covering material 12 that covers the mounting surface 10b.

[0017] As shown in Figure 2, the substrate 30 extends parallel to the main surfaces 10a and 10b, and as shown in Figure 3, has a first main surface 30a facing the main surface 10a side and a second main surface 30b facing the mounting surface 10b side. The first main surface 30a and the second main surface 30b are parallel to each other. The substrate 30 is placed inside the base body 10 and can be placed, for example, at an intermediate position between the main surface 10a and the mounting surface 10b. The substrate 30 extends between the side surfaces 10c and 10d and is exposed from the side surfaces 10c and 10d. The thickness of the substrate 30 is 10 to 80 μm (40 μm as an example). The substrate 30 is an insulating substrate made of insulating material. A substrate in which glass cloth is impregnated with cyanate resin (BT (bismaleimide-triazine) resin: registered trademark) can be used for the substrate 30. In addition to BT resin, polyimide, aramid, epoxy, etc. can also be used. The substrate 30 can be made of ceramic or glass. The substrate 30 can be made of mass-produced printed circuit board material, such as the resin material used in BT printed circuit boards, FR4 printed circuit boards, or FR5 printed circuit boards.

[0018] As shown in Figure 4, the substrate 30 according to this embodiment has a base portion 31 that extends along the opposing direction of the sides 10c and 10d when viewed from the thickness direction (second direction) of the substrate 30. In this embodiment, when viewed from the thickness direction of the substrate 30, the base portion 31 has a belt-like shape that extends in the opposing direction of the sides 10c and 10d and has a predetermined width. Both ends of the base portion 31 in relation to the extension direction are exposed from the sides 10c and 10d, respectively. The first direction, which is the extension direction of the base portion 31, may be the opposing direction of the sides 10c and 10d, or it may be a direction that intersects with the opposing direction of the sides 10c and 10d (i.e., a direction that is inclined to some extent from the opposing direction of the sides 10c and 10d). Furthermore, the substrate 30 according to this embodiment has a portion that extends in the opposing direction of the sides 10e and 10f when viewed from its thickness direction (i.e., a direction perpendicular to the thickness direction of the substrate 30 and the opposing direction of the sides 10c and 10d). Specifically, the substrate 30, when viewed in the thickness direction, has a portion 32 that extends from the base portion 31 in the direction opposite to the sides 10e and 10f near the side 10c, and is exposed from the side 10c. The substrate 30 also has a portion 33 that extends from the base portion 31 in the direction opposite to the sides 10e and 10f near the side 10d, when viewed in the thickness direction, and is exposed from the side 10d. Furthermore, the substrate 30 has a portion 34 that extends from the base portion 31 in the direction opposite to the sides 10e and 10f at an intermediate position between the sides 10c and 10d, when viewed in the thickness direction, and is exposed from each of the sides 10e and 10f.

[0019] In this embodiment, the ratio of the area of ​​the substrate 30 to the area of ​​the base body 10 (hereinafter also referred to as the substrate area ratio) when viewed from the thickness direction of the substrate 30 is designed to be 0.55 or less. When the substrate area ratio is 0.55 or less, a high inductance value can be expected. The inventors confirmed the relationship between the substrate area ratio and the inductance value by simulation analysis that mimics the 3D model shown below. For the simulation analysis, the Maxwell 3D conditions of ANSYS Electronics Desktop software from ANSYS Corporation were used. Specifically, the inductance value at 1 MHz was measured for each of the eight types of inductors (samples 1 to 8) with different substrate area ratios. In samples 1 to 8, the area of ​​the base body 10 when viewed from the thickness direction of the substrate 30 is a constant value of 1.8995 mm². 2 The dimensions were set to (1.45 mm in the opposing direction of sides 10c and 10d × 1.31 mm in the opposing direction of sides 10e and 10f), and only the substrate area was changed. The results are shown in table (a) and graph (b) of Figure 19. As shown in Figure 19, the inductance value decreases as the substrate area ratio increases, but it was confirmed that a singularity exists at a substrate area ratio of 0.55. That is, the slopes of the approximate lines for samples 1-3 and the approximate lines for samples 4-7 differed significantly, and the substrate area ratio at their intersection was 0.55. From these results, it was confirmed that when the substrate area ratio is 0.55 or less, a higher inductance value can be obtained compared to when the substrate area ratio exceeds 0.55.

[0020] The first internal conductor 40 is formed on the substrate 30 within the base body 10. The first internal conductor 40 according to this embodiment is composed of two conductor portions, a first conductor portion 41 formed on the first main surface 30a of the base portion 31 of the substrate 30, and a second conductor portion 42 formed on the second main surface 30b of the base portion 31. The first conductor portion 41 and the second conductor portion 42 formed on the base portion 31 extend along the first direction in which the base portion 31 extends, and in this embodiment, they extend along the opposing directions of the side surfaces 10c and 10d. Therefore, when viewed from the thickness direction of the substrate 30, the overall shape of the first internal conductor 40 is a shape that extends along the first direction in which the base portion 31 extends. Also, when viewed from the thickness direction of the substrate 30, the overall shape of the first internal conductor 40 is symmetrical with respect to a reference line L parallel to the first direction in which the base portion 31 extends.

[0021] The first conductor portion 41 and the second conductor portion 42 of the first internal conductor 40 can be made of, for example, copper, and can be formed by electroplating.

[0022] As shown in Figure 5(a), the first conductor portion 41 extends on the first main surface 30a from the side surface 10c to approximately the midpoint between the side surface 10c and the side surface 10d. The first conductor portion 41 has a first end 41a close to the side surface 10c and a second end 41b further away from the side surface 10c, and the width between the first end 41a and the second end 41b is designed to be uniform. The first conductor portion 41 has a rectangular cross-sectional shape in a cross section perpendicular to its direction of extension. Regarding the cross-sectional dimensions of the first conductor portion 41, its width is 100 to 800 μm (200 μm as an example), and its height is 40 to 400 μm (200 μm as an example). The first end 41a of the first conductor portion 41 is exposed from the side surface 10c and is electrically connected to the end face covering portion 21 of the terminal electrode 20A that covers the side surface 10c. The second end 41b of the first conductor portion 41 is rounded into a semicircular shape when viewed from the thickness direction of the substrate 30, and terminates near the midpoint between the side surface 10c and the side surface 10d.

[0023] As shown in Figure 5(b), the second conductor portion 42 extends on the second main surface 30b from side surface 10d to approximately midway between side surface 10c and side surface 10d. The second conductor portion 42 has a first end portion 42a close to side surface 10d and a second end portion 42b further away from side surface 10d, and the width between the first end portion 42a and the second end portion 42b is designed to be uniform. The second conductor portion 42 has a rectangular cross-sectional shape in a cross section perpendicular to its extension direction. The cross-sectional dimensions of the second conductor portion 42 are designed to be the same as those of the first conductor portion 41. The first end portion 42a of the second conductor portion 42 is exposed from side surface 10d and is electrically connected to the end face covering portion 21 of the terminal electrode 20B that covers side surface 10d. The second end portion 42b of the second conductor portion 42 is rounded into a semicircular shape when viewed from the thickness direction of the substrate 30 and terminates approximately midway between side surface 10c and side surface 10d.

[0024] As shown in Figure 2, the second end 41b of the first conductor portion 41 and the second end 42b of the second conductor portion 42 overlap with respect to the thickness direction of the substrate 30. The first internal conductor 40 further comprises a via conductor 45 that penetrates the substrate 30 in its thickness direction, and the second end 41b of the first conductor portion 41 and the second end 42b of the second conductor portion 42 are electrically connected by the via conductor 45. The via conductor 45 according to this embodiment has a cylindrical outer shape and exhibits a circular shape when viewed from the thickness direction of the substrate 30. The via conductor 45 is provided in a through hole provided in the substrate 30. The diameter of the via conductor 45 (i.e., the diameter of the through hole) is 20 to 60 μm (40 μm as an example). The diameter of the via conductor 45 can be designed to be no more than twice the thickness of the substrate 30. The via conductor 45 can be made of, for example, copper and can be formed by electroplating. If the diameter of the via conductor 45 is less than or equal to twice the thickness of the substrate 30, the via conductor 45 can be provided so as to reliably fill the through-hole by electroplating.

[0025] As described above, the first end 41a of the first conductor portion 41 is connected to the terminal electrode 20A on the side surface 10c, and the first end 42a of the second conductor portion 42 is connected to the terminal electrode 20B on the side surface 10d. Therefore, the first internal conductor 40 as a whole constitutes a single conductor provided between the pair of terminal electrodes 20A and 20B.

[0026] The surfaces of the first conductor portion 41 and the second conductor portion 42 of the first internal conductor 40 are entirely covered by insulators 51 and 52, as shown in Figures 2, 3, and 5. The insulators 51 and 52 provide insulation between the material constituting the base body 10 and the first conductor portion 41 and the second conductor portion 42. The insulators 51 and 52 are made of insulating material such as epoxy resin. Specifically, the first conductor portion 41 is covered by the insulator 51 on the first main surface 30a, and the second conductor portion 42 is covered by the insulator 52 on the second main surface 30b. Both the insulators 51 and 52 have a side covering portion 53 that covers the sides of the conductor portions 41 and 42 and a top covering portion 54 that covers the top surfaces of the conductor portions 41 and 42. The thickness of the side covering portion 53 of the insulators 51 and 52 is, for example, 10 to 40 μm (20 μm as an example), and the thickness of the top covering portion 54 is, for example, 1 to 40 μm (10 μm as an example). The insulating material constituting the side covering portion 53 and the insulating material constituting the top covering portion 54 may be the same or different.

[0027] In this embodiment, the side covering portions 53 of the insulators 51 and 52 are formed from a resist provided on the substrate 30. That is, the resist provided on the substrate 30 is patterned to form the side covering portions 53 that stand substantially perpendicular to the main surfaces 30a and 30b. The conductor portions 41 and 42 can be formed by electroplating to fill the space defined by the side covering portions 53. The top covering portions 54 of the insulators 51 and 52 are formed after the conductor portions 41 and 42 are formed, so as to cover the top surfaces of the conductor portions 41 and 42.

[0028] The cross-sectional shape of the conductor portions 41 and 42 (more specifically, the cross-sectional shape in a cross section perpendicular to the direction of extension) is determined by the dimensions of the plating-filled space defined by the side covering portions 53 of the insulators 51 and 52, or by the plating conditions such as the plating time. In other words, the cross-sectional shape of the conductor portions 41 and 42 can be freely adjusted by adjusting the height of the resist provided on the substrate 30, for example, or by adjusting the plating time.

[0029] As described above, in inductor 1, the first internal conductor 40 extends along the first direction, which is the direction in which the base portion 31 of the substrate 30 extends, and is not wound. Therefore, inductor 1 can achieve a lower inductance value compared to a wound internal conductor. In addition, since the first conductor portion 41 and the second conductor portion 42 of the first internal conductor 40 are formed on the substrate 30 using, for example, electroplating, their thickness (length in the thickness direction of the substrate 30) can be designed without restriction, thereby allowing for easy adjustment of the inductance value. On the other hand, in conventional inductors, in which a conductor layer is provided between layers of a laminated structure, the inductance value can only be adjusted in discrete values ​​because it is limited by the thickness of the conductor layer (or an integer multiple thereof), making fine adjustment difficult.

[0030] Furthermore, the first direction, which is the direction in which the base portion 31 of the substrate 30 extends, does not necessarily have to coincide with the opposing directions of the sides 10c and 10d, but may be a direction intersecting the opposing directions of the sides 10c and 10d. In this case, the first internal conductor 40 can also extend in a direction intersecting the opposing directions of the sides 10c and 10d. In addition, the first internal conductor 40 may meander like a meander coil as long as it extends along the first direction.

[0031] Inductor 1 can take various forms, not limited to the configuration described above. Below, we will describe inductors with configurations different from those described above, referring to Figures 6-18 and 20-27.

[0032] In the configurations shown in Figures 6 and 7, the insulators 51 and 52 extend along the entire length between the sides 10c and 10d on the base portion 31 of the substrate 30, covering the surfaces of the first conductor portion 41 and the second conductor portion 42. Insulator 51 has an insulating portion 51a that overlaps with a part of the second conductor portion 42 via the substrate 30. The top surface of insulator 51 is a smooth surface (without steps) from the portion covering the surface of the first conductor portion 41 to the insulating portion 51a. Insulator 52 has an insulating portion 52a that overlaps with a part of the first conductor portion 41 via the substrate 30. The top surface of insulator 52 is a smooth surface (without steps) from the portion covering the surface of the second conductor portion 42 to the insulating portion 52a, similar to the top surface of insulator 51. When the top surfaces of the insulators 51 and 52 are smooth, they become stable when placed on a flat surface, which improves workability in the manufacturing process and reduces internal stress in the substrate 30 and the first internal conductor 40.

[0033] In the configuration shown in Figures 8 and 9, a third conductor portion 43 is provided on the first main surface 30a, adjacent to the first conductor portion 41, and a fourth conductor portion 44 is provided on the second main surface 30b, adjacent to the second conductor portion 42, as a second internal conductor insulated from the first internal conductor 40. The third conductor portion 43 is adjacent to the first conductor portion 41 with respect to the first direction, which is the direction in which the base portion 31 extends, and has a shape that extends along the first direction. The first conductor portion 41 and the third conductor portion 43 are spaced apart and are insulated by an insulator 51 that integrally covers the first conductor portion 41 and the third conductor portion 43. The cross-sectional shape of the third conductor portion 43 may be the same as or different from the cross-sectional shape of the first conductor portion 41. The fourth conductor portion 44 is adjacent to the second conductor portion 42 with respect to the first direction, and has a shape that extends along the first direction. The second conductor portion 42 and the fourth conductor portion 44 are spaced apart and are insulated from each other by an insulator 52 that integrally covers both the second conductor portion 42 and the fourth conductor portion 44. The cross-sectional shape of the fourth conductor portion 44 may be the same as or different from the cross-sectional shape of the second conductor portion 42.

[0034] In the configurations shown in Figures 10 and 11, the first internal conductor 40 consists only of a first conductor portion 41 provided on the first main surface 30a. Neither the second conductor portion 42 nor the insulator 52 described above are provided on the second main surface 30b. The first conductor portion 41 extends along the entire length between the sides 10c and 10d, with its second end portion 41b exposed from the side 10d and electrically connected to the end face covering portion 21 of the terminal electrode 20B. Conversely, the first internal conductor 40 may consist only of a second conductor portion 42 provided on the second main surface 30b. In this case, the second conductor portion 42 extends along the entire length between the sides 10c and 10d, with its second end portion 42b exposed from the side 10c and electrically connected to the end face covering portion 21 of the terminal electrode 20A.

[0035] In the configurations shown in Figures 12 and 13, similar to the configurations shown in Figures 10 and 11, the first internal conductor 40 consists only of a first conductor portion 41 provided on the first main surface 30a. Only an insulator 52 is provided on the second main surface 30b. The first conductor portion 41 extends along the entire length between the sides 10c and 10d, with its second end portion 41b exposed from the side 10d and electrically connected to the end face covering portion 21 of the terminal electrode 20B. The insulator 52 extends along the entire length between the sides 10c and 10d.

[0036] In the configuration shown in Figures 14 and 15, no via conductor 45 is provided, and the first conductor portion 41 and the second conductor portion 42 of the first internal conductor 40 are insulated. The first conductor portion 41 extends along the entire length between the sides 10c and 10d, with its second end portion 41b exposed from the side 10d and electrically connected to the end face covering portion 21 of the terminal electrode 20B. The second conductor portion 42 extends along the entire length between the sides 10c and 10d, with its second end portion 42b exposed from the side 10c and electrically connected to the end face covering portion 21 of the terminal electrode 20A. In this case, the first conductor portion 41 and the second conductor portion 42 are connected in parallel between the terminal electrodes 20A and 20B. Since the inductor 1 functions using only one of the first conductor portion 41 and the second conductor portion 42, the other of the first conductor portion 41 and the second conductor portion 42 may be separated by a gap and spaced apart from the sides 10c and 10d (i.e., insulated from the terminal electrodes 20A and 20B).

[0037] In the configuration shown in Figures 16 and 17, the first internal conductor 40 is composed of three conductor sections, including two first conductor sections 41A and 41B formed on the first main surface 30a and one second conductor section 42 formed on the second main surface 30b. The first conductor sections 41A and 41B are adjacent with respect to the first direction, with the first conductor section 41A located on the side surface 10c and the first conductor section 41B located on the side surface 10d. Both the first conductor section 41A and the first conductor section 41B have a shape that extends along the first direction, similar to the first conductor section 41 described above. The lengths of the first conductor section 41A and the first conductor section 41B with respect to the first direction may be the same or different.

[0038] The first end 41a of the first conductor portion 41A, closest to the side surface 10c, is exposed from the side surface 10c and electrically connected to the end face covering portion 21 of the terminal electrode 20A. The second end 41b of the first conductor portion 41A, away from the side surface 10c, terminates in the middle of the base portion 31. The first end 41a of the first conductor portion 41B, closest to the side surface 10d, is exposed from the side surface 10d and electrically connected to the end face covering portion 21 of the terminal electrode 20B. The second end 41b of the first conductor portion 41B, away from the side surface 10d, terminates in the middle of the base portion 31. The second conductor portion 42 has a shape that extends along the first direction, similar to the second conductor portion 42 described above. Both ends 42a and 42b of the second conductor portion 42 are away from the side surfaces 10c and 10d and are not exposed from the side surfaces 10c and 10d. The second end 42b of the second conductor portion 42, near the side surface 10c, overlaps with the second end 41b of the first conductor portion 41A in the thickness direction of the substrate 30 and is electrically connected by a via conductor 45. The first end 42a of the second conductor portion 42, near the side surface 10d, overlaps with the second end 41b of the first conductor portion 41B in the thickness direction of the substrate 30 and is electrically connected by a via conductor 45. The first internal conductor 40, including the three conductor portions 41A, 41B, and 42, as a whole constitutes a single conductor provided between a pair of terminal electrodes 20A and 20B.

[0039] As shown in Figure 18, the inductor 1 may further include a pair of connecting conductors 60A and 60B that extend in the thickness direction within the substrate 10 and connect both ends of the first internal conductor 40 (i.e., the first end 41a of the first conductor portion 41 and the first end 42a of the second conductor portion 42) to terminal electrodes 20A and 20B provided on the mounting surface 10b. In this case, the terminal electrodes 20A and 20B may be L-shaped electrodes that continuously cover each side 10c and 10d of the substrate 10 and the mounting surface 10b, as shown in Figure 2, or they may be bottom-electrode type electrodes where the terminal electrodes 20A and 20B are provided only on the mounting surface 10b of the substrate 10, as shown in Figure 18. The first end 41a of the first conductor portion 41 can be electrically connected to the connecting conductor 60A and the terminal electrode 20A via a via conductor 46 provided on the substrate 30. The ends of the substrate 30 and the first internal conductor 40 may or may not be exposed from the sides 10c and 10d.

[0040] In the configuration shown in Figures 20-23, the substrate 30 has, when viewed from the thickness direction of the substrate 30, a base portion 31 that extends in a meandering manner, a portion 32 that extends in the opposite direction of sides 10e and 10f near side 10c and is exposed from side 10c, a portion 33 that extends in the opposite direction of sides 10e and 10f near side 10d and is exposed from side 10d, and a portion 34 that extends from the base portion 31 in the opposite direction of sides 10e and 10f at an intermediate position between side 10c and side 10d and is exposed from each of sides 10e and 10f.

[0041] In this embodiment, the base portion 31 has an inverted S-shape (a mirrored S-shape), has a predetermined width, and includes two portions 35 that are locally parallel to the opposing directions of the sides 10e and 10f. The end portion 31a of the base portion 31 on the side 10c side is integrally connected to portion 32 at the end portion 32a on the side 10f side of portion 32, and the end portion 31b of the base portion 31 on the side 10d side is integrally connected to portion 33 at the end portion 33a on the side 10e side of portion 33.

[0042] The first conductor portion 41 has an exposed portion 41c that extends in the direction opposite to the sides 10e and 10f on the portion 33 of the first main surface 30a and is exposed from the side 10d, and a meandering portion 41d that meanders along the base portion 31 on the base portion 31 of the first main surface 30a and extends to near the center of the base portion 31. The exposed portion 41c is designed to have a uniform width along its entire length, and the meandering portion 41d is also designed to have a uniform width along its entire length. Both the exposed portion 41c and the meandering portion 41d have a rectangular cross-sectional shape in a cross section perpendicular to their direction of extension. The exposed portion 41c is exposed from the side 10d and is electrically connected to the end face covering portion 21 of the terminal electrode 20B that covers the side 10d. One end of the meandering portion 41d is integrally connected to the exposed portion 41c at the end on the side surface 10e of the exposed portion 41c, and the other end of the meandering portion 41d is rounded in a semicircular shape when viewed from the thickness direction of the substrate 30 and terminates near the center of the base portion 31.

[0043] The second conductor portion 42 has an exposed portion 42c that extends in the direction opposite to the sides 10e and 10f on the portion 32 of the second main surface 30b and is exposed from the side 10c, and a meandering portion 42d that meanders along the base portion 31 on the base portion 31 of the second main surface 30b and extends to near the center of the base portion 31. The exposed portion 42c is designed to have a uniform width along its entire length, and the meandering portion 42d is also designed to have a uniform width along its entire length. Both the exposed portion 42c and the meandering portion 42d have a rectangular cross-sectional shape in a cross section perpendicular to their direction of extension. The exposed portion 42c is exposed from the side 10c and is electrically connected to the end face covering portion 21 of the terminal electrode 20A that covers the side 10c. One end of the meandering portion 42d is integrally connected to the exposed portion 42c at the end on the side surface 10f of the exposed portion 42c, and the other end of the meandering portion 42d is rounded in a semicircular shape when viewed from the thickness direction of the substrate 30 and terminates near the center of the base portion 31. The meandering portion 41d of the first conductor portion 41 and the meandering portion 42d of the second conductor portion 42 overlap each other with respect to the thickness direction of the substrate 30 near the center of the base portion 31 and are electrically connected by a via conductor 45 that penetrates the substrate 30 in its thickness direction.

[0044] In the configurations shown in Figures 24-27, the base portion 31 also exhibits an inverted S-shape (a mirrored S-shape), but its curvature is smaller than that of the base portion 31 in the configurations shown in Figures 20-23, and it includes one portion 35 that is locally parallel to the opposing directions of the sides 10e and 10f near the center of the base portion 31. In the configurations shown in Figures 24-27, as in the configurations shown in Figures 20-23, the first conductor portion 41 has an exposed portion 41c that extends on portion 33 of the first main surface 30a in the opposing directions of the sides 10e and 10f and is exposed from the side 10d, and a meandering portion 41d that meanders along the base portion 31 on the base portion 31 of the first main surface 30a and extends to near the center of the base portion 31. Furthermore, the second conductor portion 42 has an exposed portion 42c that extends in the opposite direction of the sides 10e and 10f on the portion 32 of the second main surface 30b and is exposed from the side 10c, and a meandering portion 42d that meanders along the base portion 31 on the base portion 31 of the second main surface 30b and extends to near the center of the base portion 31.

[0045] In the configurations shown in Figures 20-23 and Figures 24-27, when viewed from the thickness direction of the substrate 30, the meandering portion 41d of the first conductor portion 41 and the meandering portion 42d of the second conductor portion 42 are composed of curved portions and do not include bent portions. If a bent portion were included, it is conceivable that cracks would occur in that portion, or that the insulators 51 and 52 would be damaged or peeled off. If the meandering portion 41d of the first conductor portion 41 and the meandering portion 42d of the second conductor portion 42 are formed by bending a conductor such as a metal plate, it is conceivable that a restoring force (springback) would occur in the bent portion, making it impossible to maintain the shape.

[0046] In the configurations shown in Figures 20-23 and Figures 24-27, when viewed from the thickness direction of the substrate 30, the meandering portion 41d of the first conductor portion 41 and the meandering portion 42d of the second conductor portion 42 meander along the base portion 31. In other words, the base portion 31 meanders along the meandering portion 41d of the first conductor portion 41 and the meandering portion 42d of the second conductor portion 42. That is, the base portion 31 is provided only in the area necessary for forming the meandering portion 41d of the first conductor portion 41 and the meandering portion 42d of the second conductor portion 42, thus saving space in the base portion 31. As a result, sufficient magnetic volume can be secured for the magnetic material (magnetic powder-containing resin) constituting the base body 10. This makes L value adjustment easier and enables a wide lineup of low L value products. Furthermore, when viewed from the thickness direction of the substrate 30, the connections between the ends of the meandering portions 41d and 42d and the ends of the exposed portions 41c and 42c are located diagonally opposite each other on the base body 10, resulting in a large distance between them. This makes it difficult for the magnetic fluxes generated at the two connection points to influence each other (for example, cancel each other out). As a result, L-value adjustment becomes easier, and the L-value can be improved.

[0047] As can be seen from the above description, this specification discloses the following: [Note 1] The base body and, A substrate provided within the aforementioned body, having a first principal surface and a second principal surface parallel to each other, and having a base portion extending along the first direction, Within the substrate, a first internal conductor is formed on at least one of the first main surface and the second main surface of the base portion of the substrate, A pair of external electrodes are provided on the surface of the body and connected to both ends of the first internal conductor, respectively. Equipped with, An inductor in which, when viewed from a second direction perpendicular to the first main surface of the substrate, the first internal conductor extends along the first direction. [Note 2] The first internal conductor has a plurality of conductor portions, including a first conductor portion formed on the first main surface and a second conductor portion formed on the second main surface. The inductor as described in Appendix 1, wherein the ends of the first conductor portion and the end of the second conductor portion, which overlap in the second direction, are connected via a via conductor that penetrates the substrate. [Note 3] The inductor according to appendix 1 or 2, further comprising an insulator that overlaps the first internal conductor and the substrate. [Note 4] The inductor according to Appendix 1, further comprising a second internal conductor that overlaps with the first internal conductor by at least a portion via the substrate and is insulated from the first internal conductor. [Note 5] The first internal conductor has a plurality of conductor portions, including a first conductor portion formed on the first main surface and a second conductor portion formed on the second main surface. The ends of the first conductor portion and the end of the second conductor portion, which overlap in the second direction, are connected via a via conductor that penetrates the substrate. The inductor according to Appendix 4, wherein the second internal conductor includes at least one of a third conductor portion that partially overlaps with the second conductor portion of the first internal conductor via the substrate and is spaced apart from the first conductor portion of the first internal conductor on the first main surface, and a fourth conductor portion that partially overlaps with the first conductor portion of the first internal conductor via the substrate and is spaced apart from the second conductor portion of the first internal conductor on the second main surface. [Note 6] The inductor described in any one of the appendices 1 to 5, wherein, when viewed from the second direction, the first internal conductor is symmetrical with respect to a reference line extending along the first direction. [Note 7] An inductor according to any one of the appendices 1 to 6, wherein, when viewed from the second direction, the ratio of the area where the substrate exists to the area of ​​the base body is 0.55 or less. [Note 8] The aforementioned body has a mounting surface, and at least a portion of the external electrode is provided on the mounting surface. The inductor according to any one of the appendices 1 to 7, further comprising a pair of connecting conductors that extend within the element along the second direction and connect each of the ends of the first internal conductor to the external electrodes of the portion provided on the mounting surface. [Note 9] A base body having a pair of sides, A substrate provided within the body, having a first main surface and a second main surface parallel to each other, and a base portion that extends meanderingly between the pair of side surfaces, Within the substrate, a first internal conductor is formed on at least one of the first main surface and the second main surface of the base portion of the substrate, A pair of external electrodes are provided on the surface of the body and connected to both ends of the first internal conductor, respectively. Equipped with, An inductor in which, when viewed from a second direction perpendicular to the first main surface of the substrate, the first internal conductor extends along the base portion. [Note 10] The substrate further has a pair of portions that are exposed on each of the pair of sides and extend along the sides, The inductor according to Appendix 9, wherein the first internal conductor has a pair of exposed portions that extend along the side surfaces on the pair of portions and are exposed from the pair of side surfaces, and a meandering portion that meanders along the base portion on the base portion. [Note 11] The inductor according to appendix 9 or 10, wherein, when viewed from the second direction, the connection between the end of the meandering portion and the ends of the pair of exposed portions are in a diagonal positional relationship. [Explanation of Symbols]

[0048] 1...Inductor, 10...Element, 10a, 10b...Main surface, 10c, 10d, 10e, 10f...Side, 20A, 20B...Terminal electrodes, 30...Substrate, 30a...First main surface, 30b...Second main surface, 40...First internal conductor, 41...First conductor section, 42...Second conductor section, 43...Third conductor section, 44...Fourth conductor section, 45, 46...Via conductors, 51, 52...Insulator, 60A, 60B...Connecting conductors, L...Reference line.

Claims

1. The base body and, A substrate provided within the aforementioned body, having a first principal surface and a second principal surface parallel to each other, and having a base portion extending along the first direction, Within the substrate, a first internal conductor is formed on at least one of the first main surface and the second main surface of the base portion of the substrate, A pair of external electrodes are provided on the surface of the body and connected to both ends of the first internal conductor, respectively. Equipped with, An inductor in which, when viewed from a second direction perpendicular to the first main surface of the substrate, the first internal conductor extends along the first direction.

2. The first internal conductor has a plurality of conductor portions, including a first conductor portion formed on the first main surface and a second conductor portion formed on the second main surface. The inductor according to claim 1, wherein the ends of the first conductor portion and the end of the second conductor portion that overlap in the second direction are connected via a via conductor that penetrates the substrate.

3. The inductor according to claim 1, further comprising an insulator that overlaps the first internal conductor and the substrate.

4. The inductor according to claim 1, further comprising a second internal conductor that at least a portion overlaps the first internal conductor with the substrate and is insulated from the first internal conductor.

5. The first internal conductor has a plurality of conductor portions, including a first conductor portion formed on the first main surface and a second conductor portion formed on the second main surface. The ends of the first conductor portion and the end of the second conductor portion, which overlap in the second direction, are connected via a via conductor that penetrates the substrate. The inductor according to claim 4, wherein the second internal conductor includes at least one of a third conductor portion that partially overlaps with the second conductor portion of the first internal conductor via the substrate and is spaced apart from the first conductor portion of the first internal conductor on the first main surface, and a fourth conductor portion that partially overlaps with the first conductor portion of the first internal conductor via the substrate and is spaced apart from the second conductor portion of the first internal conductor on the second main surface.

6. The inductor according to claim 1, wherein, when viewed from the second direction, the first internal conductor is symmetrical with respect to a reference line extending along the first direction.

7. The inductor according to claim 1, wherein, when viewed from the second direction, the ratio of the area where the substrate exists to the area of ​​the base body is 0.55 or less.

8. The aforementioned body has a mounting surface, and at least a portion of the external electrode is provided on the mounting surface. The inductor according to claim 1, further comprising a pair of connecting conductors that extend within the element along the second direction and connect each of the ends of the first internal conductor to the external electrodes of the portion provided on the mounting surface.

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