Inductor

Abstract

This inductor comprises: a conductive member which comprises a metal material and which has a body part that extends in a conduction direction and a pair of lead-out parts that are respectively connected to both ends of the body part in the conduction direction; an exterior member which is formed using a magnetic material and which covers the conductive member; and an electrode member which is connected to the lead-out parts and at least part of which is exposed from the exterior member. The body part has a center part which includes the center of the body part in the conduction direction and a pair of wide parts which sandwich the center part and which are respectively connected to the pair of lead-out parts. The area of a cross-section of the center part intersecting the conduction direction is smaller than that of the wide parts.

Description

inductor

[0001] The present disclosure relates to inductors.

[0002] Inductors have traditionally been used in a wide range of electronic devices, such as DC-DC converters, for purposes such as stepping up and down power supply voltages and smoothing direct current. Recently, high-frequency drive DC-DC converters, in which the switching frequency in the drive circuit of the DC-DC converter device is increased, have also become known. Furthermore, with the increase in switching frequency, inductors exhibiting low inductance values ​​have also been developed. As a specific inductor structure, for example, Patent Document 1 discloses a magnetic element having a flat, current-carrying member.

[0003] WO 2006 / 070544

[0004] The above-mentioned conventional magnetic elements may not have sufficient performance as inductors.

[0005] An inductor according to one aspect of the present disclosure comprises: a current-carrying member made of a metal material, having a main body extending along a current-carrying direction and a pair of lead-out portions connected to both ends of the main body in the current-carrying direction; an exterior member formed using a magnetic material and covering the current-carrying member; and an electrode member connected to the lead-out portions and at least a portion of which is exposed from the exterior member, wherein the main body has a central portion that includes the center of the main body in the current-carrying direction, and a pair of wide portions that sandwich the central portion and are each connected to one of the pair of lead-out portions, and the central portion has a smaller cross-sectional area intersecting the current-carrying direction than the wide portions.

[0006] According to the present disclosure, higher performance inductors and the like are provided.

[0007] Fig. 1 is a schematic perspective view showing the configuration of an inductor according to an embodiment. Fig. 2 is a top view, a side view, and a bottom view of the inductor according to the embodiment. Fig. 3 is a diagram for explaining dimensions of each part of the inductor according to the embodiment. Fig. 4 is a flowchart showing a method for manufacturing the inductor according to the embodiment. Fig. 5 is a top view, a side view, and a bottom view of an inductor according to another example of the embodiment.

[0008] (Disclosure of Knowledge) The magnetic element disclosed in Patent Document 1 functions as an inductor by covering a flat current-carrying member with an exterior member. In this case, magnetic flux is formed so as to circulate around the current-carrying member in a plane intersecting the current-carrying direction. It is also known that the longer the magnetic path length of the magnetic flux, the lower the magnetic efficiency (inductance value). On the other hand, if the magnetic path length is shortened by reducing the cross-sectional area of ​​the current-carrying member intersecting the current-carrying direction to improve magnetic efficiency, the direct current resistance (DCR) of the current-carrying member increases, making the inductor more susceptible to heat generation. In other words, the inductor disclosed in Patent Document 1 may not have sufficient performance as an inductor, and an improvement is desired that reduces the DC resistance without reducing magnetic efficiency.

[0009] Therefore, in the present disclosure, by changing the cross-sectional area of ​​the cross section of the current-carrying member that intersects the current-carrying direction at each point in the current-carrying direction, it is possible to suppress the decrease in magnetic efficiency in some parts while reducing the value of DC resistance in other parts, thereby realizing an inductor that meets the above-mentioned requirements.

[0010] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0011] Note that the embodiments described below each illustrate a specific example of the present disclosure. The numerical values, shapes, materials, components, component placement positions, connection configurations, steps, and step sequences shown in the following embodiments are examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in independent claims are described as optional components.

[0012] Furthermore, in this specification, terms indicating the relationship between elements, such as parallelism, terms indicating the shape of elements, such as rectangular parallelepiped, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0013] In addition, each drawing is a schematic diagram in which emphasis, omission, or adjustment of proportions has been appropriately made to illustrate the present disclosure, and is not necessarily an exact illustration, and may differ from the actual shape, positional relationship, and proportion. In each drawing, substantially the same configuration is assigned the same reference numeral, and duplicated explanations may be omitted or simplified.

[0014] In addition, each figure shows three mutually orthogonal axes, X, Y, and Z, which are used for explanation purposes as needed. Each axis is added for explanation purposes only and does not limit the direction or posture in which the inductor is used.

[0015] (Embodiment) [Configuration] First, an inductor according to an embodiment of the present disclosure will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a schematic perspective view showing the configuration of an inductor according to the embodiment. Fig. 1 shows the general shape of a sheath member 10, which will be described later, and further shows the interior of the sheath member 10 in a see-through manner. For example, components such as a main body 40 that are hidden by being embedded in the sheath member 10 are shown with dashed lines, indicating that the main body 40 and the like can be seen through the sheath member 10.

[0016] 2A and 2B are top, side, and bottom views of the inductor according to the embodiment. More specifically, (a) of Fig. 2A shows a top view of the inductor 100 as seen from the positive side of the Z axis in Fig. 1, (b) of Fig. 2B shows a side view of the inductor 100 as seen from the positive side of the Y axis in Fig. 1, and (c) of Fig. 2B shows a bottom view of the inductor 100 as seen from the negative side of the Z axis in Fig. 1. In Fig. 2, components embedded in the exterior member 10 are shown transparently with dashed lines, as in Fig. 1.

[0017] 1 and 2 , the inductor 100 includes an exterior member 10, a main body 40, a first lead-out portion 52, a second lead-out portion 53, a first electrode member 25, and a second electrode member 35. The first lead-out portion 52 and the second lead-out portion 53 are an example of a pair of lead-out portions, and may be collectively referred to simply as lead-out portions when there is no need to distinguish them from each other.

[0018] The inductor 100 is, for example, a rectangular parallelepiped metal composite core inductor, and its approximate outer shape is determined by the shape of the exterior member 10. The exterior member 10 can be formed into any shape by molding. In other words, the inductor 100 can have any shape depending on the shape of the exterior member 10 during molding. The inductor 100 is a passive element that stores electrical energy flowing between the first electrode member 25 and the second electrode member 35 as magnetic energy in the main body 40.

[0019] The exterior member 10 is an outer shell portion of the inductor 100 that covers the main body 40 and the pair of lead-out portions 52, 53, and is, for example, a powder magnetic core that is made of a metal magnetic powder, a resin material, etc. The exterior member 10 may be made of any magnetic material, such as ferrite, or other materials.

[0020] The metal magnetic powder is a particulate material having a predetermined elemental composition, such as an Fe-Si-Al system, an Fe-Si system, an Fe-Si-Cr system, or an Fe-Si-Cr-B system. The resin material is selected from materials such as silicone that can maintain a certain shape by binding together the metal magnetic powder particles while insulating them from one another. The exterior member 10 has substantially rectangular opposing surfaces (surfaces on both sides of the X-axis) on which the first electrode member 25 and the second electrode member 35 are formed, respectively. The four sides of each opposing surface are connected by a top surface (upper surface, the surface on the positive side of the Z-axis), a bottom surface (lower surface, the surface on the negative side of the Z-axis), and two side surfaces (surfaces on both sides of the Y-axis), forming a substantially rectangular prism shape.

[0021] In this embodiment, the inductor 100 has a sheath member 10 with dimensions of, for example, 8.0 mm in the X-axis direction, 5.0 mm in the Y-axis direction, and 3.0 mm in the Z-axis direction, but is not limited to this. As with the above description of the shape, the inductor 100 can be realized with any size by adjusting the dimensions of the sheath member 10. Furthermore, the dimensions of the main body 40 and the first and second electrode members 25 and 35 may be determined according to the shape of the inductor 100.

[0022] The main body 40 has a flat plate shape with a constant thickness in a thickness direction (Z-axis direction in the figure) that intersects (e.g., perpendicular to) the current-carrying direction (X-axis direction in the figure). The main body 40 is made of a metal material selected from metals such as aluminum, copper, silver, and gold, alloys containing one or more of these metals, and materials composed of metals or alloys and other substances. The main body 40 extends along the current-carrying direction, and a pair of lead-out portions 52, 53 are connected to both ends of the main body 40. The main body 40 and the pair of lead-out portions 52, 53 are collectively referred to as a current-carrying member 60. The length in the width direction (Y-axis direction in the figure) along the plate surface that intersects (e.g., perpendicular to) the current-carrying direction and thickness direction in which the main body 40 extends and that runs parallel to the plate surface is defined as the "width" in the following description.

[0023] The main body 40 includes a central portion 41 having a constant width including the center of the main body 40, and a pair of wide portions connected to both ends of the central portion 41. Specifically, the pair of wide portions includes a first wide portion 42 connecting the central portion 41 to the first lead-out portion 52 and a second wide portion 43 connecting the central portion 41 to the second lead-out portion 53. The width (length) of the central portion 41 in the width direction is shorter than both the width (length) of the first wide portion 42 and the width (length) of the second wide portion 43. Because the main body 40 has a constant thickness, the cross-sectional area of ​​a cross section 41S of the central portion 41 intersecting the current-carrying direction (perpendicular to the current-carrying direction in the present embodiment) is smaller than both the cross-sectional area of ​​a cross section 42S of the first wide portion 42 intersecting the current-carrying direction (perpendicular to the current-carrying direction in the present embodiment) and the cross-sectional area of ​​a cross section 43S of the second wide portion 43 intersecting the current-carrying direction (perpendicular to the current-carrying direction in the present embodiment). Conversely, the cross-sectional area of ​​the first wide portion 42 and the cross-sectional area of ​​the second wide portion 43 are both larger than the cross-sectional area of ​​the central portion 41 .

[0024] For example, the central portion 41 is smaller than the average cross-sectional area of ​​a cross section of the main body portion 40 intersecting the current-carrying direction (orthogonal in the present embodiment), and the cross-sectional area of ​​the pair of wide portions 42, 43 is larger than the average cross-sectional area of ​​the main body portion 40. In other words, the width (length) of the central portion 41 in the width direction is smaller than the average width of the main body portion 40 in the width direction, and the width of the pair of wide portions 42, 43 is larger than the average width of the main body portion 40. Furthermore, for example, the cross section of the central portion 41 intersecting the current-carrying direction (orthogonal in the present embodiment) is smaller than the average cross-sectional area of ​​cross sections 52S, 53S of the current-carrying member 60 (main body portion 40 and the pair of lead-out portions 52, 53) intersecting the current-carrying direction (orthogonal in the present embodiment), and the average cross-sectional area of ​​the pair of wide portions 42, 43 is larger than the average cross-sectional area of ​​the current-carrying member 60. In other words, the width (length) of the central portion 41 in the width direction is smaller than the average width of the current-carrying member 60 in the width direction, and the width (length) of the pair of wide portions 42, 43 in the width direction is larger than the average width of the current-carrying member 60. In this way, the central portion 41 has a relatively short outer circumferential length in a cross section intersecting the current-carrying direction relative to the main body portion 40 or the entire current-carrying member 60, and the magnetic path length around it is also relatively short. On the other hand, the cross sections 42S, 43S of the pair of wide portions 42, 43 intersecting the current-carrying direction have relatively large cross-sectional areas in the cross sections intersecting the current-carrying direction relative to the main body portion 40 or the entire current-carrying member 60.

[0025] Here, the exterior member 10 is formed by pressure molding, and during this process, the packing density of the metal magnetic powder increases the closer to the center of the exterior member 10. Therefore, it can be said that the area near the center of the exterior member 10 is most effective in suppressing a decrease in magnetic efficiency when the magnetic path length is shortened. Although the center of the main body 40 may not strictly coincide with the center of the exterior member 10, it is considered that these centers are approximately overlapping. As described above, the magnetic path length of the main body 40 is relatively short near the center 41, making it easier to achieve the effect of suppressing a decrease in magnetic efficiency.

[0026] Furthermore, the pair of wide portions 42, 43 have a relatively large cross-sectional area, which facilitates reducing the DC resistance of the entire current-carrying member 60. FIG. 3 is a diagram illustrating the dimensions of each portion of an inductor according to an embodiment. FIG. 3 shows the inductor 100 in the process of being formed, viewed from the same perspective as FIG. 2B. In the inductor 100, for example, the length of the center portion 41 in the current-carrying direction is 20% to 40% of the entire length of the current-carrying member 60 (indicated by the thick double-headed arrow). More preferably, the length of the center portion 41 in the current-carrying direction is 30% of the entire length of the current-carrying member 60. By setting the length of the center portion 41 in this manner, the magnetic path length around the main body 40 near the center of the exterior member 10, where the filling density of the metal magnetic powder is relatively high, can be kept short. Meanwhile, the length of the pair of wide portions 42, 43 in the current-carrying direction is 15% to 35% of the entire length of the current-carrying member 60. More preferably, the length of the pair of wide portions 42 and 43 in the current-carrying direction may be 25% of the entire length of the current-carrying member 60 .

[0027] The first lead-out portion 52 is connected to the first electrode member 25. The second lead-out portion 53 is connected to the second electrode member 35. As will be described in detail later, in this embodiment, the main body portion 40, the pair of lead-out portions 52, 53, the first electrode member 25, and the second electrode member 35 are integrally formed without any connecting portions. In other words, the main body portion 40, the pair of lead-out portions 52, 53, and the first electrode member 25 and the second electrode member 35 are names given to each portion formed by processing a single member made of the same material.

[0028] The first electrode member 25 and the second electrode member 35 are plate-shaped portions formed using the same material as the main body 40, and at least a portion thereof is exposed from the exterior member 10. External electrical components and the like are connected to these exposed portions to form an electrical product including the inductor 100. Note that the first electrode member 25 and the second electrode member 35 may be formed separately from the main body 40 and the pair of lead-out portions 52, 53. In this case, the first electrode member 25 and the second electrode member 35 are connected to the main body 40 via the pair of lead-out portions 52, 53, and connection portions for electrical connection are formed at the connection points.

[0029] Furthermore, the first electrode member 25 and the second electrode member 35 are bent and curved at the connection points with the pair of lead-out portions 52, 53 so as to follow the opposing surfaces, which are the surfaces of the exterior member 10, and extend downward. The first electrode member 25 before bending is a first extension plate portion 26. The first extension plate portion 26 has the same thickness as the current-carrying member 60 and is formed integrally with the current-carrying member 60. The second electrode member 35 before bending is a second extension plate portion 36. The second extension plate portion 36 has the same thickness as the current-carrying member 60 and is formed integrally with the current-carrying member 60 from a single flat-plate-shaped metal material.

[0030] The first extension plate portion 26 and the second extension plate portion 36 are bent at the ridge line connecting the opposing surface and the underside to form the first contact point 27 and the second contact point 37 that extend further along the underside. By arranging the contact points of the electrode members on the underside in this manner, it becomes possible to directly connect the inductor 100 to a land (not shown) on a mounting board or the like on which the inductor 100 is mounted.

[0031] When using an integrated current-carrying member 60 and electrode member as described above, if the inductor 100 is formed by bending the first and second extension plate portions 26 and 36 on the surface of the exterior member 10, cracks (cracks, chips, etc.) may occur in the exterior member 10. Because cracks can reduce the performance and durability of the inductor 100, it is preferable to prevent cracks from occurring. In this embodiment, the first and second extension plate portions 26 and 36 are bent by pressing downward against the pair of extension portions 52 and 53 at the portions of the exterior member 10 corresponding to the bent portions, i.e., the contact portions between the exterior member 10 and the points where the pair of lead-out portions 52 and 53 connect to the first and second extension plate portions 26 and 36. The ridge lines connecting the inner surface and the opposing surface of the exterior member 10 are used as fulcrums to fulcrum the ridge lines and both end portions of the ridge lines, which are subject to a large load and are prone to cracks. In particular, when bending the flat first extension plate portion 26 and second extension plate portion 36, the longer the width of the fold, the greater the force that tries to maintain the original flat plate, and the greater the likelihood of cracks occurring.

[0032] Therefore, in this embodiment, to reduce the above-mentioned effect, the widths of the connection portions between the pair of lead-out portions 52, 53 and the first and second extension plate portions 26, 36 are also shorter than the widths of the pair of wide portions 42, 43. More specifically, in the inductor 100, the widths of the pair of lead-out portions 52, 53 and the portions of the first and second extension plate portions 26, 36 that connect to the connection portions with the pair of lead-out portions 52, 53 are shorter than the widths of the pair of wide portions 42, 43. As a result, even if the first electrode member 25 and the second electrode member 35 are formed by bending as described above, cracks are less likely to occur, making it easier to maintain the performance and durability of the inductor 100. The length of the pair of lead-out portions 52, 53 in the current-carrying direction is 0% or more and 20% or less of the overall length of the current-carrying member 60. More preferably, the length of the pair of lead-out portions 52 and 53 in the current-carrying direction may be 10% of the entire length of the current-carrying member 60 .

[0033] [Manufacturing Method] Next, a manufacturing method of the above-described inductor 100 will be described with reference to Fig. 4. Fig. 4 is a flowchart showing a manufacturing method of an inductor according to an embodiment. In manufacturing the inductor 100 according to this embodiment, first, a metal material integrally including the main body portion 40, the pair of lead-out portions 52, 53, and the first and second extension plate portions 26, 36 is prepared (preparation step S101). In the preparation step S101, a metal material including the main body portion 40, the pair of lead-out portions 52, 53, and the first and second extension plate portions 26, 36 is obtained by punching out the metal material from a flat metal plate using a mold.

[0034] Following the preparation step S101, the main body 40 and the pair of lead-out portions 52, 53 are covered with the exterior member 10 (exterior step S102). In the exterior step S102, the main body 40 and the pair of lead-out portions 52, 53 of the prepared flat-plate-shaped metal material are covered with a powder magnetic core, thereby determining the outer shape of the inductor 100.

[0035] Following the packaging step S102, the first and second elongated plate portions 26 and 36 are folded (finishing step S103). In the finishing step S103, the first and second elongated plate portions 26 and 36 are folded so as to fit the packaging member 10. Specifically, the first and second elongated plate portions 26 and 36 are folded sequentially at the ridge lines connecting the inner surface and the opposing surface of the packaging member 10 and the ridge lines connecting the opposing surface and the bottom surface, thereby sequentially forming the first and second electrode members 25 and 35, and the first and second contacts 27 and 37. In this manner, the inductor 100 according to the embodiment is manufactured.

[0036] The following describes the results of a simulation to verify the performance of the inductor 100 formed as described above. In this simulation, the inductor 100 is assumed to have a sheath member 10 measuring 8.0 mm in the X-axis direction, 5.0 mm in the Y-axis direction, and 3.0 mm in the Z-axis direction (Example). In the simulation, the current-carrying member 60 is 0.4 mm thick, and the main body 40 is 1.5 mm wide and 30% of the current-carrying member 60 in length in the current-carrying direction. The pair of wide portions 42, 43 are 2.6 mm wide and 25% of the current-carrying member 60 in length in the current-carrying direction. The pair of lead-out portions 52, 53 are 1.5 mm wide and 10% of the current-carrying member 60 in length in the current-carrying direction. For comparison, a similar simulation was also performed on an inductor having a current-carrying member 60 with a constant thickness of 0.4 mm and a width of 2.0 mm (Comparative Example).

[0037] While the inductance value of the comparative example was 40 nH, the same 40 nH was maintained in the example, while the DC resistance value was confirmed to be 8% lower in the example than in the comparative example. As a result of this verification, it was confirmed that the performance of the inductor can be improved by providing a change in cross-sectional area between the center portion 41 and the wide portion.

[0038] [Another Example] An inductor according to another example of the embodiment will be described below with reference to Fig. 5. Note that the following description will focus on differences from the description of the above embodiment, and points that are substantially the same as those in the description of the embodiment may be omitted or simplified.

[0039] 5A and 5B are top, side, and bottom views of an inductor 100a according to another embodiment of the present invention, taken from the same perspective as in FIG.

[0040] The inductor 100a differs from the inductor 100 in the configuration of its wide portions. Specifically, the inductor 100a has a main body 40a that includes a central portion 41, a first wide portion 42a, and a second wide portion 43a. The main body 40a and the lead-out portions 52, 53 form a current-carrying member 60a. While the inductor 100 uses a flat plate-shaped main body 40, the inductor 100a uses a main body 40a whose thickness, which is the length in the thickness direction, varies in the current-carrying direction. The thickness is locally larger in the first wide portion 42a and the second wide portion 43a. In other words, the thickness of the wide portions 42a, 43a is larger than the thickness of the central portion 41 and the lead-out portions 52, 53.

[0041] As described in the above embodiment, the inductor of the present disclosure is configured to reduce the magnetic path length in the center to suppress deterioration of magnetic properties, while increasing the cross-sectional area in the wide portions to reduce DC resistance. If the width of the plate-shaped current-carrying member penetrating the exterior member 10 were too wide, the exterior member 10 would be more susceptible to cracking on the upper and lower surfaces than the current-carrying member. Therefore, in another example, the thicknesses of the first wide portion 42 a and the second wide portion 43 a are locally increased to locally increase the cross-sectional area in the first wide portion 42 a and the second wide portion 43 a. Such current-carrying members can be formed by controlling the thickness, for example, by stacking metal materials in the wide portions 42 a and 43 a.

[0042] As described above, when the cross-sectional area of ​​the wide portion is increased to reduce the DC resistance in the wide portion, not only the width of the wide portion but also the thickness of the wide portion may be increased.

[0043] [Effects, etc.] As described above, the inductor 100 according to the first aspect includes a main body 40 made of a metal material and extending in the current-carrying direction, a current-carrying member 60 having a pair of lead-out portions (first lead-out portion 52 and second lead-out portion 53) connected to both ends of the main body 40 in the current-carrying direction, an exterior member 10 made of a magnetic material and covering the current-carrying member 60, and electrode members (first electrode member 25 and second electrode member 35) connected to the lead-out portions 52 and 53 and at least partially exposed from the exterior member. The main body 40 has a central portion 41 that includes the center of the main body 40 in the current-carrying direction, and a pair of wide portions 42 and 43 (first wide portion 42 and second wide portion 43) that sandwich the central portion 41 and are connected to the pair of lead-out portions 52 and 53, respectively. The cross-sectional area of ​​the center portion 41 intersecting the current flow direction is smaller than the cross-sectional area of ​​the wide portion intersecting the current flow direction (or the cross-sectional area of ​​either the first wide portion 42 or the second wide portion 43 intersecting the current flow direction).

[0044] In this inductor 100, the central portion 41 has a smaller cross-sectional area than the wide portions 42 and 43. For example, when the current-carrying member 60 has a constant thickness, the central portion 41 has a shorter cross-sectional perimeter than the wide portions 42 and 43. Therefore, the magnetic path length around the current-carrying member 60 is relatively short at the central portion 41. If the exterior member 10 is formed by pressure molding, the center of the exterior member 10 has a higher packing density of magnetic material than the other portions. This allows the center of the exterior member 10 to overlap with the vicinity of the central portion 41, which has a relatively short magnetic path length. As a result, a decrease in magnetic efficiency (inductance value) near the central portion 41 can be suppressed. Furthermore, the relatively small cross-sectional area of ​​the central portion 41 is compensated for by the relatively large cross-sectional area of ​​the wide portions 42 and 43, which has the advantage of easily reducing DC resistance. In this way, a higher-performance inductor 100 can be realized, since DC resistance can be easily reduced while suppressing a decrease in magnetic efficiency.

[0045] Furthermore, the inductor 100 according to the second aspect is the inductor 100 according to the first aspect, in which the current-carrying member 60 has a flat plate shape with a constant thickness, and the difference in cross-sectional area between the central portion 41 and the wide portions 42, 43 is obtained by the difference in the length in the width direction that intersects with the thickness direction of the current-carrying member 60; that is, in this embodiment in particular, the difference is obtained only by the difference in the length in the width direction out of the difference in the thickness (length) in the thickness direction of the current-carrying member 60 and the difference in the length in the width direction.

[0046] This allows the outer circumferential length of the cross section of the flat plate-shaped current-carrying member 60 to be shorter at the center 41 than at the wide portions 42 and 43 .

[0047] Furthermore, the inductor 100 according to a third aspect is the inductor 100 according to the first or second aspect, in which the electrode members 25 , 35 are bent on the surface of the exterior member 10 and extend along the exterior member 10 .

[0048] This makes it possible to realize an inductor 100 that includes electrode members 25, 35 that extend along the exterior member 10. If the electrode members 25, 35 extend along the exterior member 10, the movement of the electrode members 25, 35 relative to the exterior member 10 is restricted, making it easier to maintain the physical connection between the electrode members 25, 35 and the exterior member 10.

[0049] Furthermore, the inductor 100 according to the fourth aspect is the inductor 100 according to the third aspect, in which the current-carrying member 60 and the electrode members 25, 35 are integrated, and the cross-sectional area of ​​the cross section (52S, 53S) of the derivation portion (at least one of the first derivation portion 52 and the second derivation portion 53) intersecting the current-carrying direction is smaller than the cross-sectional areas 42S, 43S of the cross sections of the wide portions 42, 43 intersecting the current-carrying direction (more than either the cross-sectional areas 42S, 43S of the cross sections of the first wide portion 42 or the second wide portion 43 intersecting the current-carrying direction).

[0050] This allows the current-carrying member 60 and the electrode members 25, 35 to be formed in a single process using a single member. Here, the bend is formed by bending the portion where the current-carrying member 60 and the electrode members 25, 35 are integrated so that the electrode members 25, 35 extend along the exterior member 10. If the cross-sectional area of ​​the lead-out portions 52, 53 were relatively large, bending would be difficult, increasing the likelihood that an external force applied during bending would cause a crack in the exterior member 10. In the inductor 100 here, the cross-sectional areas of the lead-out portions 52, 53 are smaller than the cross-sectional areas 42S, 43S of the wide portions 42, 43. Therefore, the cross-sectional areas of the lead-out portions 52, 53 are relatively small, reducing the likelihood that an external force applied during bending would cause a crack in the exterior member 10. As a result, the inductor 100 is less susceptible to cracking, making it less likely that the performance and durability of the inductor 100 will be reduced.

[0051] Furthermore, the inductor 100 according to the fifth aspect is the inductor 100 according to the fourth aspect, in which the current-carrying member 60 and the electrode members 25, 35 are flat-plate shaped, and the difference in cross-sectional area between the wide portions 42, 43 and the lead-out portions 52, 53 is obtained by the difference in length in the width direction that intersects with the thickness direction of the current-carrying member 60.

[0052] This allows the cross-sectional area of ​​the lead-out portions 52 and 53 to be smaller than that of the wide portions 42 and 43 in the flat-plate-shaped current-carrying member 60 and electrode members 25 and 35 .

[0053] In addition, the inductor 100 according to the sixth aspect is the inductor 100 according to any one of the first to fifth aspects, in which the length of the central portion 41 in the current-carrying direction is 40% or less of the entire current-carrying member 60.

[0054] This allows the main body 40 to include the central portion 41 whose length in the current-carrying direction is 40% or less of the entire current-carrying member 60. If the central portion 41, i.e., the portion with a small cross-sectional area, is made longer than necessary, the DC resistance tends to increase, so the above configuration makes it easier to suppress such an increase in DC resistance.

[0055] In addition, the inductor 100 according to the seventh aspect is the inductor 100 according to any one of the first to sixth aspects, in which the length of the central portion 41 in the current-carrying direction is 20% or more of the entire current-carrying member 60.

[0056] This allows the main body 40 to include the central portion 41 whose length in the current-carrying direction is 20% or more of the entire current-carrying member 60. If the central portion 41, i.e., the portion with a small cross-sectional area, is made shorter than necessary, the magnetic efficiency is likely to decrease, so the above configuration makes it easier to suppress such a decrease in magnetic efficiency.

[0057] (Other Embodiments) Although the inductors and the like according to the embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments.

[0058] For example, the present invention also includes electrical appliances or electrical circuits that use the above-described inductor. Examples of electrical appliances include power supply devices that include the above-described inductor.

[0059] Furthermore, the present disclosure is not limited to the embodiment, and various modifications conceivable by those skilled in the art to the present embodiment and forms constructed by combining components of different embodiments may also be included within the scope of one or more aspects, as long as they do not deviate from the spirit of the present disclosure.

[0060] The inductor according to the present disclosure is useful as a high-frequency inductor.

[0061] REFERENCE SIGNS LIST 10 Exterior member 25 First electrode member 26 First extended plate portion 27 First contact point 35 Second electrode member 36 Second extended plate portion 37 Second contact point 40 Main body portion 41 Central portion 42, 42a First wide portion 43, 43a Second wide portion 52 First lead-out portion 53 Second lead-out portion 100, 100a Inductor

Claims

1. An inductor comprising: a current-carrying member made of a metallic material, having a main body extending in a current-carrying direction and a pair of lead-out portions connected to both ends of the main body in the current-carrying direction; an exterior member made of a magnetic material and covering the current-carrying member; and electrode members connected to the lead-out portions and at least a portion of which is exposed from the exterior member, wherein the main body has a central portion that includes the center of the main body in the current-carrying direction, and a pair of wide portions that sandwich the central portion and are each connected to one of the pair of lead-out portions, and wherein the cross-sectional area of ​​the central portion intersecting the current-carrying direction is smaller than the cross-sectional area of ​​the wide portions intersecting the current-carrying direction.

2. The inductor according to claim 1, wherein the current-carrying member has a flat plate shape with a thickness direction intersecting the current-carrying direction, and the difference between the cross-sectional area of ​​the central portion and the cross-sectional area of ​​the wide portion is obtained by the difference in length of the current-carrying member in a width direction intersecting the thickness direction.

3. The inductor according to claim 1, wherein the electrode member is bent on the surface of the exterior member and extends along the exterior member.

4. The inductor according to claim 3, wherein the current-carrying member and the electrode member are integrated, and the cross-sectional area of ​​the cross section intersecting the current-carrying direction of the lead-out portion is smaller than the cross-sectional area of ​​the cross section of the wide portion.

5. An inductor according to claim 4, wherein the current-carrying member and the electrode member are flat plates having a thickness direction intersecting the current-carrying direction, and the difference between the cross-sectional area of ​​the wide portion and the cross-sectional area of ​​the lead-out portion is obtained by the difference in length of the current-carrying member in the width direction intersecting the thickness direction.

6. An inductor according to any one of claims 1 to 5, wherein the length of the central portion in the current-carrying direction is 40% or less of the entire current-carrying member.

7. An inductor according to any one of claims 1 to 5, wherein the length of the central portion in the current-carrying direction is 20% or more of the entire current-carrying member.

Images