JP7526927B2 - Inductors - Google Patents

Description

This disclosure relates to an inductor.

Inductors are passive elements that store electrical energy as magnetic energy and are used, for example, in DC-DC converter devices for the purposes of stepping up and down power supply voltages and smoothing direct currents. Inductors are mounted, for example, on the surface of a circuit board. For example, Patent Document 1 discloses an inductor that includes a main body that contains a magnetic material, a coil element that is disposed inside the main body, and a terminal metal fitting that is connected to the coil element. In the inductor described in Patent Document 1, the tip of the coil element is exposed from the main body, and a terminal metal fitting is welded to the exposed tip of the coil element.

JP 2011-243685 A

In conventional inductors, the reliability of the connection between the electrode member (terminal metal fitting) and the coil element may be low, resulting in low reliability of the inductor. In view of the above, the present disclosure aims to improve the reliability of inductors.

An inductor according to one aspect of the present disclosure includes a magnetic core including a magnetic material and having a top surface, a bottom surface, and side surfaces connected to the top surface and the bottom surface, a coil element including a coil portion embedded in the magnetic core and a lead-out portion connected to an end of the coil portion and drawn out from the side surface to an outside of the magnetic core, electrode members arranged on the side surface and the bottom surface, and a connection portion connecting the lead-out portion and the electrode member, the lead-out portion extending along the side surface outside the magnetic core, and the electrode member including a bottom plate portion arranged along the bottom surface, a connecting portion connected to the bottom plate portion and having the lead-out portion between them. the first mounting plate portion has an opposing side plate portion that faces the side surface with a gap therebetween, and a first mounting plate portion that is connected to the opposing side plate portion and extends in a direction toward the side surface, the first mounting plate portion has an edge portion that at least a portion of which contacts the pull-out portion along the extension direction of the pull-out portion, and the connection portion has a first connection portion where the pull-out portion and the edge portion of the first mounting plate portion are welded together, and when the length of the first connection portion in the extension direction of the pull-out portion is L1, the thickness of the first mounting plate portion is t1, and the cross-sectional area of the pull-out portion is S, the relationship L1 ≧ (S × 0.2)/t1 is satisfied.
An inductor according to one aspect of the present disclosure includes a magnetic core including a magnetic material and having a top surface, a bottom surface, and side surfaces connected to the top surface and the bottom surface, a coil element including a coil portion embedded in the magnetic core and an extension portion connected to an end of the coil portion and extended from the side surface to an outside of the magnetic core, electrode members disposed on the side surface and the bottom surface, and a connection portion connecting the extension portion and the electrode member, the extension portion extending along the side surface outside the magnetic core, and the electrode member including a bottom plate portion disposed along the bottom surface, the electrode member further includes an opposing side plate portion connected to the opposing side plate portion and facing the side surface with a gap therebetween, and a first mounting plate portion connected to the opposing side plate portion and extending in a direction toward the side surface, the first mounting plate portion having an edge portion that at least a portion thereof contacts the extending portion along the extending direction of the extending portion, the connecting portion having a first connecting portion formed by welding the extending portion to an edge portion of the first mounting plate portion, and the electrode member further includes a first mounting plate portion facing the first mounting plate portion with the extending portion interposed therebetween, connected to the opposing side plate portion and extending in a direction toward the side surface, the opposing side plate portion has a first region wider than the drawn-out portion and a second region wider than the drawn-out portion and narrower than the first region, the first and second disposed plate portions are connected to the first region of the opposing side plate portion, the electrode member further has a third disposed plate portion connected to the second region of the opposing side plate portion, facing the first disposed plate portion across the drawn-out portion, and disposed extending in a direction toward the side surface, and at least a portion of the third disposed plate portion is connected to the drawn-out portion. the connection portion has an edge portion that contacts the pull-out portion along the extension direction of the pull-out portion, and the connection portion further has a second connection portion in which the pull-out portion and an edge portion of the third installation plate portion are welded to each other, and when the length of the first connection portion in the extension direction of the pull-out portion is L1, the thickness of the first installation plate portion is t1, and the cross-sectional area of the pull-out portion is S, a relationship of L1 ≧ (S × 0.15)/t1 is satisfied, and when the length of the second connection portion in the extension direction of the pull-out portion is L2, and the thickness of the third installation plate portion is t3, a relationship of L2 ≧ (S × 0.05)/t3 is satisfied.

This disclosure makes it possible to improve the reliability of inductors.

1 is a perspective view of an inductor according to an embodiment; 2 is a diagram showing a state in which a connection portion is removed from the inductor shown in FIG. 1 and electrode members are separated. FIG. 2 is a front view of the inductor according to the embodiment. 1 is a side view of an inductor according to an embodiment; FIG. 2 is a top view of the inductor according to the embodiment. 2 is a perspective view of a coil element included in the inductor according to the embodiment; FIG. 7 is a cross-sectional view of an electrode member and an extension portion of the inductor according to the embodiment taken along line VII-VII in FIG. 4. 4 is a flowchart showing a method for manufacturing an inductor according to an embodiment. FIG. 11 is a perspective view of an inductor according to a first modified example of the embodiment. 10 is a diagram showing a state in which a connection portion is removed from the inductor shown in FIG. 9 and electrode members are separated. 11 is a cross-sectional view of an extended portion and an electrode member of an inductor according to a first modified example of an embodiment, as viewed from the top surface side of the inductor. FIG. FIG. 11 is a perspective view of an inductor according to a second modified example of the embodiment. 13 is a diagram showing a state in which a connection portion is removed from the inductor shown in FIG. 12 and electrode members are separated. 11 is a cross-sectional view of an extended portion and an electrode member of an inductor according to a second modified example of an embodiment, as viewed from the top surface side of the inductor. FIG. 13 is a diagram showing an inductor according to a third modified example of the embodiment, in which a connection portion is removed from the inductor and electrode members are separated. FIG.

(Background to this disclosure)
In the structure in which the electrode member is welded to the tip of the coil element as in the above-mentioned Patent Document 1, the cross-sectional area of the connection portion connecting the coil element and the electrode member is small, and the reliability of the connection between the coil element and the electrode member may be reduced. In addition, in the structure in which the electrode member is welded to the tip of the coil element, the cross-sectional area of the current path at the welded portion cannot be increased, and the direct current resistance increases, resulting in a problem of reduced reliability of the inductor. In addition, if the cross-sectional area of the current path at the welded portion cannot be increased, the temperature rise occurs when the inductor is energized, resulting in a problem of reduced reliability of the inductor. In addition, for example, when the electrode member of the inductor is connected to a circuit board or the like by reflow soldering, if the heat capacity of the inductor (especially the magnetic core) is large, the solder is difficult to melt, and the reliability of the connection between the circuit board or the inductor may be reduced.

The present disclosure has the following configuration to improve the reliability of the inductor. The following describes the embodiment in more detail with reference to the drawings.

Note that each of the embodiments described below shows a specific example of the present disclosure. The numerical values, shapes, materials, components, component placement positions, connection forms, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim are described as optional components.

In addition, in this specification, terms indicating the relationship between elements, such as "parallel," terms indicating the shape of an element, such as "cuboid," and numerical ranges are not expressions that express only a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

In addition, each figure is a schematic diagram in which emphasis, omissions, or adjustments to the ratio have been made as appropriate to illustrate the present disclosure, and is not necessarily an exact illustration, and may differ from the actual shape, positional relationship, and ratio. In each figure, the same reference numerals are used for substantially the same configuration, and duplicate explanations may be omitted or simplified.

Each figure also shows the X-axis, Y-axis, and Z-axis, which represent three mutually orthogonal directions, and these axes and the axial directions along these axes are used as necessary for explanation. Note that each axis is added for explanation purposes only, and does not limit the direction or posture in which the inductor can be used.

In addition, in this specification, the terms "top surface" and "bottom surface" in the inductor configuration do not refer to the top surface (surface on the vertically upper side) and bottom surface (surface on the vertically lower side) in an absolute spatial sense, but are used as terms defined by the relative positional relationships of the components of the inductor.

(Embodiment)
[composition]
The configuration of an inductor according to an embodiment will be described below. An inductor is a passive element that stores electrical energy flowing through a coil element as magnetic energy.

Figure 1 is a perspective view of an inductor 100 according to an embodiment. Figure 2 is a diagram showing the inductor 100 shown in Figure 1 with the connection portion 40 removed and the electrode member 30 separated. Figure 3 is a front view of the inductor 100. Figure 4 is a side view of the inductor 100. Figure 5 is a top view of the inductor 100.

In addition, in Figures 3 to 5, a front view is a view looking from the positive side to the negative side of the Y axis, a side view is a view looking from the positive side to the negative side of the X axis, and a top view is a view looking from the positive side to the negative side of the Z axis. These are the same for the other figures in the following explanation. Also, Figure 4 shows a side view of the electrode member 30 without the opposing side plate portion 35. Also, a part of Figure 5 shows a cross-sectional view of the inductor 100 shown in Figure 4 at line V-V. Also, in Figure 5, the shape of the coil element 20 viewed from the top is shown by a solid line or a dashed line.

As shown in Figures 1 to 5, the inductor 100 includes a magnetic core 10, a coil element 20 having a coil portion 21 and an extension portion 22, an electrode member 30 which is an external terminal, and a connection portion 40 which connects the extension portion 22 and the electrode member 30.

The following explanation will mainly focus on the positive half of the X-axis of inductor 100, but the negative half of the X-axis of inductor 100 has a similar structure to the positive half of the X-axis of inductor 100, and the same explanation applies.

The approximate outer shape of the inductor 100 is determined by the shape of the magnetic core 10, which is, for example, a rectangular parallelepiped powder magnetic core. The magnetic core 10 can be molded into any shape. In other words, an inductor 100 of any shape can be realized depending on the shape of the magnetic core 10 during molding. In the magnetic core 10 of this embodiment, for example, the dimension in the X-axis direction is 17 mm or more, the dimension in the Y-axis direction is 17 mm or more, and the dimension in the Z-axis direction is 7 mm or more.

The magnetic core 10 is the outer shell of the inductor 100, and covers a part of the coil element 20. The magnetic core 10 is a powder magnetic core that includes a magnetic material, for example, made of a metal magnetic powder and a resin material. The magnetic core 10 may be formed using a magnetic material. The magnetic material may be ferrite or other magnetic materials. 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 a material that can maintain a certain shape by binding the particles of the metal magnetic powder while insulating the particles of the metal magnetic powder, such as a silicone resin.

The magnetic core 10 is, for example, rectangular. The magnetic core 10 has a bottom surface 11, a top surface 12 facing away from the bottom surface 11, and four side surfaces 13a, 13b, 13c, and 13d connected to the bottom surface 11 and the top surface 12. Side surface 13a and side surface 13b are aligned in the X-axis direction and facing away from each other. Side surface 13c and side surface 13d are aligned in the Y-axis direction and facing away from each other. The bottom surface 11, top surface 12, and side surfaces 13a, 13b, 13c, and 13d are each flat planes. The pair of bottom surface 11 and top surface 12, the pair of side surfaces 13a and 13b, and the pair of side surfaces 13c and 13d are each pairs of surfaces that are in a parallel positional relationship. The bottom surface 11 and the top surface 12 extend in a direction that intersects with the side surfaces 13a, 13b, 13c, and 13d, specifically in a direction that intersects at right angles. Also, the side surfaces 13a and 13b extend in a direction that intersects with the side surfaces 13c and 13d, specifically in a direction that intersects at right angles.

The coil element 20 has a coil portion 21 embedded in the magnetic core 10 and a plurality of lead-out portions 22 exposed to the outside of the magnetic core 10.

Figure 6 is a perspective view of the coil element 20 provided in the inductor 100.

As shown in FIG. 6, the coil element 20 is composed of one coil section 21 and two lead-out sections 22. In FIG. 6, the coil section 21 is located on the positive side of the Y-axis from the dashed dotted line attached to the coil element 20, and the lead-out sections 22 are located on the negative side of the Y-axis from the dashed dotted line.

The coil element 20 is composed of, for example, a conductor. The conductor is composed of a metal wire composed 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, and an insulating coating that covers the metal wire. Specifically, the conductor is, for example, a copper wire coated with an insulating coating. The coil portion 21 and the lead-out portion 22 are names given to each portion formed, for example, by processing a single member made of the same material.

The coil portion 21 is a portion covered by the magnetic core 10. The coil portion 21 is made of a wound conductor and functions as a coil. There is no particular limit to the number of turns of the coil portion 21, and it is selected appropriately according to the performance required of the inductor 100 and constraints such as the size of the magnetic core 10, for example, from 0.5 turns to 10 turns. The cross section of the conductor constituting the coil portion 21 is, for example, a circle with a diameter of 2 mm or more, and the aspect ratio of the cross section is 1:1. The coil portion 21 is embedded in the magnetic core 10 so that the winding axis a1 of the coil portion 21 is aligned along the direction connecting the bottom surface 11 and the top surface 12 (Z-axis direction).

The coil portion 21 has two ends 21a, 21b that connect the wound portion to the side surface 13c of the magnetic core 10 (see FIG. 5). Of the two ends 21a, 21b of the coil portion 21, one end 21a is located on the positive side of the X-axis, which is closer to the right than the winding axis a1, when viewed from a direction perpendicular to the side surface 13c, and the other end 21b is located on the negative side of the X-axis, which is closer to the left than the winding axis a1. In addition, both ends 21a, 21b of the coil portion 21 are located at a height closer to the top surface 12 than the center c1 of the side surface 13c, when viewed from a direction perpendicular to the side surface 13c, and have the same height from the bottom surface 11.

As shown in FIG. 4, the draw-out portion 22 is connected to the end 21a or 21b of the coil portion 21, drawn out from the side surface 13c of the magnetic core 10, and extends along the side surface 13c. Specifically, when viewed from a direction perpendicular to the side surface 13c, the draw-out portion 22 is drawn out from a height closer to the top surface 12 than the center c1 of the side surface 13c, bends along the side surface 13c, extends in a direction connecting the bottom surface 11 and the top surface 12 (Z-axis direction), and ends before reaching the end on the bottom surface 11 side. In this embodiment, the draw-out portion 22 is drawn out from one of the four side surfaces 13c.

As shown in Figs. 1 to 5, the electrode members 30 are disposed outside the magnetic core 10 (e.g., on the bottom surface 11 side and the side surface 13c side) and are electrically connected to the draw-out portion 22 via the connection portion 40. The electrode members 30 are provided corresponding to each of the two draw-out portions 22. The electrode members 30 include a conductive material and are constituted, for example, by a metal material plate. The metal material plate is constituted by a metal material selected from metals such as aluminum, copper, silver, and gold, alloys containing one or more of these metals, and materials consisting of a metal or alloy and another substance.

The electrode member 30 has a bottom plate portion 31 arranged on the bottom surface 11 side of the magnetic core 10, an opposing side plate portion 35 connected to the bottom plate portion 31, and a first arrangement plate portion 36 and a second arrangement plate portion 37 connected to the opposing side plate portion 35. The bottom plate portion 31, the opposing side plate portion 35, the first arrangement plate portion 36, and the second arrangement plate portion 37 are names given to each part formed, for example, by processing a single member made of the same material.

The bottom plate portion 31 is disposed on the bottom surface 11 side of the magnetic core 10 so as to extend along the bottom surface 11. The bottom plate portion 31 is fixed to the magnetic core 10 via an adhesive. When the inductor 100 is mounted on the circuit board, the bottom plate portion 31 is joined to the circuit board by soldering.

The opposing side plate portion 35 is connected to the bottom plate portion 31 and faces the side surface 13c with a gap therebetween, with the drawer portion 22 in between. In other words, the opposing side plate portion 35 is positioned outboard of the drawer portion 22. In this embodiment, the opposing side plate portion 35 is positioned corresponding to one of the four side surfaces, the side surface 13c.

When viewed from a direction perpendicular to side surface 13c, opposing side plate portion 35 has outer end 35h located outside pull-out portion 22 and inner end 35i located on the winding axis a1 side, which is inside pull-out portion 22. The width w0 of opposing side plate portion 35, which is the distance between outer end 35h and inner end 35i, is wider than the width wd (diameter) of pull-out portion 22 (see FIG. 2).

The first mounting plate portion 36 is connected to the outer end portion 35h of the opposing side plate portion 35 and is disposed in a direction toward the side surface 13c of the magnetic core 10. The first mounting plate portion 36 is disposed perpendicular to the opposing side plate portion 35. The first mounting plate portion 36 also has an edge portion E1 located on the side surface 13c opposite the outer end portion 35h. At least a portion of the edge portion E1 is in contact with the pull-out portion 22 along the extension direction of the pull-out portion 22.

The second mounting plate portion 37 is connected to the inner end portion 35i of the opposing side plate portion 35 and is disposed in a direction toward the side surface 13c of the magnetic core 10. Specifically, the second mounting plate portion 37 is disposed perpendicular to the opposing side plate portion 35 and is in contact with or close to the side surface 13c.

Figure 7 is a cross-sectional view of the lead-out portion 22 and electrode member 30 of the inductor 100 taken along line VII-VII in Figure 4.

As shown in FIG. 7, the draw-out portion 22 has a covered region 23a having an insulating coating 24 on the outer circumferential surface 23 of the draw-out portion 22, and a bare region 23b where the conductor is bare without the insulating coating 24. When viewed from a direction perpendicular to the side surface 13c, the bare region 23b is formed at least in a region outside the axis a2 of the draw-out portion 22. That is, all or most of the bare region 23b is provided on the side where the first mounting plate portion 36 is arranged. For example, the length of the bare region 23b on the outer periphery of the draw-out portion 22 is 30% to 70% of the length of the outer periphery of the draw-out portion 22. It is desirable that the length of the bare region 23b be longer than the length of the covered region 23a.

The exposed region 23b is in contact with the edge E1 of the first mounting plate portion 36. A connection portion 40 is formed at the location where the exposed region 23b and the edge E1 of the first mounting plate portion 36 are in contact.

The connection portion 40 has a first connection portion 41 in which the draw-out portion 22 and the edge portion E1 of the first mounting plate portion 36 are welded. The first connection portion 41 is formed along the extension direction of the draw-out portion 22. For example, the first connection portion 41 is composed of multiple weld marks ws formed by laser seam welding, and the multiple weld marks ws are connected along the extension direction of the draw-out portion 22. All of the multiple weld marks ws may be continuously connected, or only some of the weld marks ws may be continuously connected.

The length of the first connection portion 41 in the extension direction of the draw-out portion 22 is, for example, 1.5 to 5 times the diameter of the draw-out portion 22. In addition, when the length of the first connection portion 41 in the extension direction is L1, the thickness of the first mounting plate portion 36 is t1, and the cross-sectional area of the draw-out portion 22 is S (the area hatched diagonally upward to the right), there is a relationship of L1 ≧ (S × 0.2)/t1. In the above formula, L1 × t1 corresponds to the cross-sectional area of the welded portion. Therefore, the longer the length L1 of the first connection portion 41, the larger the cross-sectional area of the welded portion.

In this embodiment, the edge E1 of the first mounting plate portion 36 is in contact with the extension direction of the lead-out portion 22. Therefore, it is possible to increase the length of the connection portion 40 formed by welding the edge E1 to the lead-out portion 22. This allows the cross-sectional area of the connection portion 40 connecting the coil element 20 and the electrode member 30 to be increased, thereby improving the reliability of the connection. In addition, the cross-sectional area of the current path in the connection portion 40 can be increased, which reduces the DC resistance and improves the reliability of the inductor. In addition, the cross-sectional area of the current path in the connection portion 40 can be increased, which suppresses temperature rise when current is applied to the inductor, thereby improving the reliability of the inductor.

[Production method]
Next, a method for manufacturing the above-mentioned inductor 100 will be described. Fig. 8 is a flowchart showing a method for manufacturing the inductor 100 according to the embodiment. Note that the manufacturing method described below is one example, and the manufacturing method of the inductor 100 is not limited to the following example. In addition, in the following description, the positive half of the inductor 100 on the X-axis side will be mainly described, but the negative half of the inductor 100 on the X-axis side can also be manufactured by a similar method, and the same description applies.

The manufacturing method of the inductor 100 first performs a step of pressure molding the magnetic core 10 together with the coil element 20 (step S11). The step S11 is performed by placing the coil element 20 having the coil portion 21 in a molding die and pressure molding the powder core. The pressure during pressure molding is, for example, 5 ton/ ^cm2 , and the thermosetting temperature is, for example, 185°C. After pressure molding, the exposed lead-out portion 22 that is not covered by the magnetic core 10 protrudes perpendicularly to, for example, the side surface 13c of the magnetic core 10.

Next, a process of forming the exposed area 23b on the outer circumferential surface 23 of the drawn-out portion 22 is performed (step S12). The exposed area 23b is formed by removing a part of the insulating coating 24 by laser irradiation or the like after step S11.

Next, a process is performed in which the drawn-out portion 22 exposed from the magnetic core 10 is bent along the side surface 13c (step S13). Specifically, the drawn-out portion 22 is bent from its base located on the side surface 13c along the side surface 13c, and is formed into a shape that extends in the direction connecting the bottom surface 11 and the top surface 12.

Next, the electrode member 30, which has been formed in advance by cutting and bending a metal plate, is attached to the magnetic core 10 using an adhesive (step S14). At this time, the electrode member 30 and the magnetic core 10 are arranged so as to have the positional relationship shown in FIG. 1, and the bottom plate portion 31 and the bottom surface 11 are attached. This step S14 brings the drawer portion 22 into contact with the edge portion E1 of the first mounting plate portion 36.

Next, a process of welding the edge E1 of the first mounting plate portion 36 and the draw-out portion 22 by laser seam welding or the like is performed (step S15). This forms the first connection portion 41 along the extension direction of the draw-out portion 22. The weld mark ws formed on the first connection portion 41 is circular, and is formed, for example, by rotating the spot of the laser beam at a predetermined radius.

Through steps S11 to S15 as described above, an inductor 100 is manufactured in which the coil element 20 and the electrode member 30 are connected by the connection portion 40.

[Effects, etc.]
As described above, the inductor 100 according to the present embodiment includes a magnetic core 10 including a magnetic material and having a bottom surface 11, a top surface 12, and a side surface 13c connected to the bottom surface 11 and the top surface 12, a coil element 20 including a coil portion 21 embedded in the magnetic core 10 and an extension portion 22 connected to an end (e.g., 21a) of the coil portion 21 and extended from the side surface 13c to the outside of the magnetic core 10, an electrode member 30 disposed on the side surface 13c and the bottom surface 11, and a connection portion 40 connecting the extension portion 22 and the electrode member 30. The extension portion 22 extends along the side surface 13c outside the magnetic core 10. The electrode member 30 includes a bottom plate portion 31 disposed along the bottom surface 11, an opposing side plate portion 35 connected to the bottom plate portion 31 and facing the side surface 13c with a gap therebetween with the extension portion 22 interposed therebetween, and a first disposed plate portion 36 connected to the opposing side plate portion 35 and disposed extending in a direction toward the side surface 13c. The first mounting plate portion 36 has an edge portion E1, at least a portion of which contacts the drawn-out portion 22 along the extension direction of the drawn-out portion 22. The connection portion 40 has a first connection portion 41 at which the drawn-out portion 22 and the edge portion E1 of the first mounting plate portion 36 are welded to each other.

In this manner, in the inductor 100 of this embodiment, the edge E1 of the first mounting plate portion 36 is in contact with the extension direction of the lead-out portion 22. Therefore, it is possible to increase the length of the first connection portion 41 formed by welding the edge E1 to the lead-out portion 22. This allows the cross-sectional area of the connection portion 40 connecting the coil element 20 and the electrode member 30 to be increased, thereby improving the reliability of the connection. Furthermore, with this configuration, the cross-sectional area of the current path in the connection portion 40 can be increased, so that the DC resistance can be reduced and the reliability of the inductor can be improved. Furthermore, since the cross-sectional area of the current path in the connection portion 40 can be increased, it is possible to suppress a temperature rise when current is applied to the inductor, thereby improving the reliability of the inductor.

The first connection portion 41 may also be formed along the extension direction of the draw-out portion 22.

According to this configuration, the length of the first connection portion 41 formed along the extension direction of the draw-out portion 22 can be increased. This allows the cross-sectional area of the connection portion 40 connecting the coil element 20 and the electrode member 30 to be increased, thereby improving the reliability of the connection. Furthermore, according to this configuration, the cross-sectional area of the current path in the connection portion 40 can be increased, which reduces the DC resistance and improves the reliability of the inductor. Furthermore, since the cross-sectional area of the current path in the connection portion 40 can be increased, it is possible to suppress a temperature rise that occurs when current is applied to the inductor, thereby improving the reliability of the inductor.

The first connection portion 41 may also be formed by connecting multiple weld marks ws.

With this configuration, the length of the first connection portion 41 can be increased, and the cross-sectional area of the connection portion 40 can be increased. This can improve the reliability of the inductor 100.

The lead-out portion 22 may have a covered region 23a having an insulating coating 24 on the outer peripheral surface 23 of the lead-out portion 22, and a bare region 23b not having the insulating coating 24, and the connection portion 40 may be formed in the bare region 23b.

This configuration can improve the reliability of the connection between the lead-out portion 22 and the electrode member 30 at the connection portion 40. This can improve the reliability of the inductor 100.

In addition, when the draw-out portion 22 is viewed in cross section, the length of the exposed region 23b at the outer periphery of the draw-out portion 22 may be 30% or more and 70% or less of the outer periphery of the draw-out portion 22.

This configuration makes it easier to form the exposed region 23b than when the entire outer periphery of the drawn-out portion 22 is made into the exposed region 23b. For example, when removing the insulating coating 24 of the drawn-out portion 22 by laser irradiation, the laser is irradiated from one direction to remove the insulating coating 24, and the exposed region 23b can be easily formed.

When viewed from a direction perpendicular to the side surface 13c, the width w0 of the opposing side plate portion 35 may be wider than the width wd of the drawer portion 22.

By widening the width w0 of the opposing side plate portion 35 in this way, for example, when connecting the electrode member 30 to a circuit board or the like by reflow soldering or the like, the heat collection ability of the electrode member 30 against the heat of a reflow furnace can be improved. This improves the melting ability of the solder during reflow, and increases the reliability of the connection between the circuit board or the like and the inductor 100.

Furthermore, when the length of the first connection portion 41 in the extension direction of the draw-out portion 22 is L1, the thickness of the first mounting plate portion 36 is t1, and the cross-sectional area of the draw-out portion 22 is S, the relationship L1 ≧ (S × 0.2)/t1 may be satisfied.

By satisfying the above relationship, the length of the first connection portion 41 can be sufficiently secured. This can improve the reliability of the inductor 100.

The electrode member 30 may further have a second mounting plate portion 37 that faces the first mounting plate portion 36 with the drawer portion 22 interposed therebetween and is connected to the opposing side plate portion 35 and extends in a direction toward the side surface 13c.

In this way, by having the electrode member 30 have the second mounting plate portion 37, for example, when connecting the electrode member 30 to a circuit board or the like by reflow soldering or the like, it is possible to improve the heat collection ability against the heat of a reflow furnace. This improves the melting ability of the solder during reflow, and increases the reliability of the connection between the circuit board or the like and the inductor 100.

The drawer section 22 may also extend along a direction connecting the bottom surface 11 and the top surface 12.

This allows the length of the first connection portion 41 to be sufficiently secured, thereby improving the reliability of the inductor 100.

(Modification of the embodiment)
In the following, inductors according to modifications of the embodiment will be described. In the following description of each modification, differences from the embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[Modification 1]
The following describes an inductor 100A according to a first modification of the embodiment. In the first modification, the inductor 100A further includes a third mounting plate portion 38 in addition to the first mounting plate portion 36 and the second mounting plate portion 37.

Figure 9 is a perspective view of an inductor 100A according to a first modified embodiment of the present invention. Figure 10 is a diagram showing the magnetic core 10 and coil element 20 of the inductor 100A shown in Figure 9 with the connection portion 40 removed and the electrode member 30A separated. Figure 11 is a cross-sectional view of the lead-out portion 22 and electrode member 30A of the inductor 100A according to the first modified embodiment, as viewed from the top surface 12 side of the inductor 100A.

The inductor 100A of the first modification includes a magnetic core 10, a coil element 20 having a coil portion 21 and an extension portion 22, an electrode member 30A that is an external terminal, and a connection portion 40 that connects the extension portion 22 and the electrode member 30A. The configuration of the magnetic core 10 is substantially the same as that of the embodiment.

The coil portion 21 has both ends that connect the wound portion to the side surface 13c of the magnetic core 10 (not shown). When viewed from a direction perpendicular to the side surface 13c, one end of the coil portion 21 is located at a height closer to the top surface 12 than the center c1 of the side surface 13c, and the other end of the coil portion 21 is located at a height closer to the bottom surface 11 than the center c1 of the side surface 13c. That is, in the first modification, the height positions of both ends of the coil portion 21 are different.

The pull-out portion 22 has a first pull-out portion 22a that connects to one end of the coil portion 21, and a second pull-out portion 22b that connects to the other end. The first pull-out portion 22a is pulled out from a position on the top surface 12 side of the height of the center c1 of the side surface 13c, and extends toward the bottom surface 11 side. The second pull-out portion 22b is pulled out from a position on the bottom surface 11 side of the height of the center c1 of the side surface 13c, and extends toward the top surface 12 side.

The electrode member 30A has a bottom plate portion 31, an opposing side plate portion 35A, a first mounting plate portion 36, and a second mounting plate portion 37, and further has a third mounting plate portion 38. The bottom plate portion 31 and the first mounting plate portion 36 are the same as in the embodiment. The bottom plate portion 31, the opposing side plate portion 35A, the first mounting plate portion 36, the second mounting plate portion 37, and the third mounting plate portion 38 are names given to each portion formed, for example, by processing a single member made of the same material.

The opposing side plate portion 35A is connected to the bottom plate portion 31 and faces the side surface 13c with a gap therebetween, with the drawer portion 22 in between. In other words, the opposing side plate portion 35A is positioned outside the drawer portion 22.

The opposing side plate portion 35A has a first region 35j that is wider than the drawn-out portion 22, and a second region 35k that is wider than the drawn-out portion 22 and narrower than the first region 35j. The first region 35j is connected to the bottom plate portion 31 and is located closer to the bottom surface 11 than the second region 35k. The second region 35k is connected to the first region 35j and is located closer to the top surface 12 than the first region 35j. The opposing side plate portion 35A has an outer end portion 35h that is located outside the drawn-out portion 22 when viewed from a direction perpendicular to the side surface 13c. In addition, the opposing side plate portion 35A has an inner end portion 35i of the first region 35j that is located closer to the winding axis a1 than the drawn-out portion 22 in the first region 35j and an inner end portion 35i of the second region 35k that is located closer to the winding axis a1 than the drawn-out portion 22 in the second region 35k when viewed from a direction perpendicular to the side surface 13c.

The second mounting plate portion 37 is connected to the inner end portion 35i of the first region 35j and is disposed in a direction toward the side surface 13c of the magnetic core 10. Specifically, the second mounting plate portion 37 is disposed perpendicular to the opposing side plate portion 35A and is in contact with or close to the side surface 13c.

The third arrangement plate portion 38 is connected to the inner end portion 35i of the second region 35k and is arranged in a direction toward the side surface 13c of the magnetic core 10. The third arrangement plate portion 38 is arranged perpendicular to the opposing side plate portion 35A and faces the first arrangement plate portion 36 with the draw-out portion 22 in between. In other words, the first arrangement plate portion 36 and the third arrangement plate portion 38 face each other when viewed from a direction perpendicular to the side surface 13c. The draw-out portion 22 is located between the first arrangement plate portion 36 and the third arrangement plate portion 38 and is sandwiched by the first arrangement plate portion 36 and the third arrangement plate portion 38.

In the inductor 100A of the first modification, the opposing side plate portion 35A has a first region 35j that is wider than the drawn-out portion 22, and a second region 35k that is wider than the drawn-out portion 22 and narrower than the first region 35j. The first arrangement plate portion 36 and the second arrangement plate portion 37 are connected to the first region 35j of the opposing side plate portion 35A. The electrode member 30A further has a third arrangement plate portion 38 that is connected to the second region 35k of the opposing side plate portion 35A, faces the first arrangement plate portion 36 across the drawn-out portion 22, and is arranged to extend in a direction toward the side surface 13c.

In this way, by having the electrode member 30A have the second mounting plate portion 37 and the third mounting plate portion 38, for example, when connecting the electrode member 30A to a circuit board or the like by reflow soldering, the heat collection ability of the reflow furnace can be improved. This improves the melting ability of the solder during reflow, and increases the reliability of the connection between the circuit board or the like and the inductor 100A. Furthermore, with this configuration, the draw-out portion 22 can be sandwiched between the first mounting plate portion 36 and the third mounting plate portion 38, improving the mechanical strength of the inductor 100A. This increases the reliability of the inductor 100A.

The pull-out portion 22 may have a first pull-out portion 22a connected to one end of the coil portion 21 and a second pull-out portion 22b connected to the other end, the first pull-out portion 22a being pulled out from a position closer to the top surface 12 than the height of the center c1 of the side surface 13c and extending toward the bottom surface 11, and the second pull-out portion 22b being pulled out from a position closer to the bottom surface 11 than the height of the center c1 of the side surface 13c and extending toward the top surface 12.

This allows for greater freedom in the pull-out position of the pull-out section 22.

[Modification 2]
An inductor 100B according to a second modification of the embodiment will be described. In the second modification, an example in which the inductor 100B includes a second connection portion 42 and the like in addition to the first connection portion 41 will be described.

Figure 12 is a perspective view of an inductor 100B according to a second modification of the embodiment. Figure 13 is a diagram showing the inductor 100B shown in Figure 12 with the connection portion 40 removed and the electrode member 30B separated. Figure 14 is a cross-sectional view of the lead-out portion 22 and electrode member 30B of the inductor 100B according to the second modification, as viewed from the top surface 12 side of the inductor 100B.

The inductor 100B of the second modification comprises a magnetic core 10, a coil element 20 having a coil portion 21 and an extension portion 22, an electrode member 30B which is an external terminal, and a connection portion 40 which connects the extension portion 22 and the electrode member 30B. The configuration of the magnetic core 10 is substantially the same as that of the embodiment, and the configuration of the coil element 20 is substantially the same as that of the first modification. In the second modification, the outer peripheral surface 23 of the extension portion 22 is not covered with an insulating coating 24, and is an exposed region 23b (not shown).

The electrode member 30B has a bottom plate portion 31, an opposing side plate portion 35A, a first mounting plate portion 36, a second mounting plate portion 37, and a third mounting plate portion 38B. The bottom plate portion 31, the opposing side plate portion 35A, the first mounting plate portion 36, and the second mounting plate portion 37 are the same as those in the first modified example.

The third arrangement plate portion 38B is connected to the inner end portion 35i of the second region 35k of the opposing side plate portion 35A and is arranged in a direction toward the side surface 13c of the magnetic core 10. The third arrangement plate portion 38B is arranged perpendicular to the opposing side plate portion 35A and faces the first arrangement plate portion 36 with the draw-out portion 22 in between. In other words, the first arrangement plate portion 36 and the third arrangement plate portion 38B face each other when viewed from a direction perpendicular to the side surface 13c. The draw-out portion 22 is located between the first arrangement plate portion 36 and the third arrangement plate portion 38B and is sandwiched by the first arrangement plate portion 36 and the third arrangement plate portion 38B.

The third mounting plate portion 38B has an edge portion E2 located on the side surface 13c opposite the inner end portion 35i. At least a portion of the edge portion E2 contacts the pull-out portion 22 along the extension direction of the pull-out portion 22. The edge portion E2 contacts the pull-out portion 22 in an area opposite the edge portion E1 when viewed from the pull-out portion 22.

The connection portion 40 has a first connection portion 41 where the draw-out portion 22 and the edge portion E1 are welded, and a second connection portion 42 where the draw-out portion 22 and the edge portion E2 are welded.

The second connection portion 42 of the second modification is also composed of a plurality of weld marks ws formed by laser seam welding, and the plurality of weld marks ws are connected along the extension direction of the pull-out portion 22. In other words, the second connection portion 42 is formed along the extension direction of the pull-out portion 22. The length of the second connection portion 42 is, for example, 1.5 to 5 times the diameter of the pull-out portion 22.

In the second modification, the connection portion 40 is composed of two connection parts, a first connection portion 41 and a second connection portion 42. Therefore, the total length of the connection portion 40, which is the total length of the first connection portion 41 and the second connection portion 42, can be increased.

On the other hand, since the second modification has two connection points, it is possible to shorten the length of each of the first connection portion 41 and the second connection portion 42 in the extension direction compared to the embodiment. Therefore, in the second modification, when the length of the first connection portion 41 in the extension direction is L1, the thickness of the first arrangement plate portion 36 is t1, and the cross-sectional area of the pull-out portion 22 is S, the relationship of L1 ≧ (S × 0.15) / t1 is satisfied, and when the length of the second connection portion 42 in the extension direction is L2, and the thickness of the third arrangement plate portion 38B is t3, the relationship of L2 ≧ (S × 0.05) / t3 may be satisfied. In the above formula, the sum of L1 × t1 and L2 × t3 corresponds to the cross-sectional area of the welded portion.

In the inductor 100B of the second modification, as in the first modification, the edge E1 of the first mounting plate portion 36 contacts the lead-out portion 22 along the extension direction. Therefore, the length of the first connection portion 41 formed by welding the edge E1 to the lead-out portion 22 can be increased.

In addition, in the inductor 100B of the second modified example, the third mounting plate portion 38B has an edge portion E2, at least a portion of which contacts the draw-out portion 22 along the extension direction of the draw-out portion 22.

In this way, in the inductor 100B of the second modified example, the edge E2 of the third mounting plate portion 38B is in contact with the extension direction of the lead-out portion 22. Therefore, it is possible to increase the length of the connection portion formed by welding the edge E2 to the lead-out portion 22. This can increase the reliability of the inductor 100B.

The connection portion 40 may further include a second connection portion 42 in which the drawer portion 22 and the edge portion E2 of the third mounting plate portion 38B are welded.

As a result, since the connection portion 40 is composed of two connection parts, the first connection portion 41 and the second connection portion 42, the length of the connection portion 40, which is the sum of the lengths of the first connection portion 41 and the second connection portion 42, can be increased. This allows the cross-sectional area of the connection portion 40 to be increased. This allows the reliability of the inductor 100B to be improved.

Furthermore, when the length of the first connection portion 41 in the extension direction of the draw-out portion 22 is L1, the thickness of the first arrangement plate portion 36 is t1, and the cross-sectional area of the draw-out portion 22 is S, the relationship L1 ≧ (S × 0.15)/t1 may be satisfied, and when the length of the second connection portion 42 in the extension direction of the draw-out portion 22 is L2, and the thickness of the third arrangement plate portion 38B is t3, the relationship L2 ≧ (S × 0.05)/t3 may be satisfied.

In this way, by having two connection points for the inductor 100B, the lengths of the first connection portion 41 and the second connection portion 42 in the extension direction of the draw-out portion 22 can be prevented from becoming longer than necessary. This makes it possible to reduce the size and height of the inductor 100B.

[Modification 3]
An inductor 100C according to a third modification of the embodiment will be described. In the third modification, an example will be described in which the two lead portions 22 are led out from the bottom surface 11 side relative to the center c1 of the side surface 13c.

Figure 15 shows the inductor 100C according to the third variation of the embodiment, with the connection portion 40 removed and the electrode member 30 separated from the inductor 100C.

The inductor 100C of the third modification includes a magnetic core 10, a coil element 20 having a coil portion 21 and an extension portion 22, an electrode member 30 which is an external terminal, and a connection portion 40 which connects the extension portion 22 and the electrode member 30. The configurations of the magnetic core 10, the electrode member 30, and the connection portion 40 are substantially the same as those of the embodiment.

The coil portion 21 has both ends that connect the wound portion to the side surface 13c of the magnetic core 10 (not shown). When viewed from a direction perpendicular to the side surface 13c, one end and the other end of the coil portion 21 are located at a height closer to the bottom surface 11 than the center c1 of the side surface 13c. In other words, in the third modification, both ends of the coil portion 21 are located at the same height.

The pull-out portion 22 has a first pull-out portion 22a that is connected to one end of the coil portion 21, and a second pull-out portion 22b that is connected to the other end. Each of the first pull-out portion 22a and the second pull-out portion 22b is pulled out from a position on the bottom surface 11 side higher than the height of the center c1 of the side surface 13c, and extends toward the top surface 12 side.

In this way, in the inductor 100C of the third modification, the lead-out portion 22 has a first lead-out portion 22a that connects to one end of the coil portion 21, and a second lead-out portion 22b that connects to the other end. Each of the first lead-out portion 22a and the second lead-out portion 22b is led out from a position on the bottom surface 11 side higher than the height of the center c1 of the side surface 13c, and extends toward the top surface 12 side.

This allows for greater freedom in the pull-out position of the pull-out portion 22. In addition, of the multiple weld marks ws in the connection portion 40, the weld mark ws closest to the bottom plate portion 31 can be brought closer to the ends 21a, 21b of the coil portion 21. This makes it possible to reduce the DC resistance between the ends 21a, 21b of the coil portion 21 and the bottom plate portion 31. Furthermore, heat generated when current is applied to the inductor 100C can be easily dissipated to the circuit board, improving the reliability of the inductor 100C.

(Other embodiments, etc.)
Although the inductors and the like according to the embodiments and each modification of the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments and each modification. As long as the gist of the present disclosure is not deviated from, the scope of the present disclosure also includes various modifications that a person skilled in the art can make to the embodiments and each modification, as well as other forms constructed by combining some of the components in the embodiments and each modification.

In the above embodiment, the bottom plate portion 31, the opposing side plate portion 35, and the first mounting plate portion 36 of the electrode member 30 are formed by processing one member made of the same material, but this is not limited thereto. For example, the electrode member 30 may be formed by connecting the bottom plate portion 31, the opposing side plate portion 35, and the first mounting plate portion 36, which are made of different members.

In the above embodiment, an example has been shown in which the coil portion 21 and the lead-out portion 22 of the coil element 20 are formed by processing one member made of the same material, but this is not limited thereto. The coil element 20 may be formed by connecting the coil portion 21 and the lead-out portion 22 made of different members.

In the above embodiment, an example in which the cross section of the lead-out portion 22 is circular is shown, but this is not limited thereto. At least a portion of the lead-out portion 22 may be expanded into a flat plate shape to facilitate connection with the electrode member 30.

In addition, for example, electrical products or electrical circuits using the above-mentioned inductors are also included in the present disclosure. Examples of electrical products include power supply devices equipped with the above-mentioned inductors and various devices equipped with such power supply devices.

The inductor disclosed herein is useful as an inductor for use in various devices and equipment.

REFERENCE SIGNS LIST 10 magnetic core 11 bottom surface 12 top surface 13a, 13b, 13c, 13d side surface 20 coil element 21 coil portion 21a, 21b end portion 22 lead portion 22a first lead portion 22b second lead portion 23 outer circumferential surface 23a coated region 23b exposed region 24 insulating coating 30, 30A, 30B electrode member 31 bottom plate portion 35, 35A opposing side plate portion 35h outer end portion 35i inner end portion 35j first region 35k second region 36 first mounting plate portion 37 second mounting plate portion 38, 38B third mounting plate portion 40 connection portion 41 first connection portion 42 second connection portion 100, 100A, 100B, 100C inductor a1 a2 Winding axis of coil portion Axis of lead-out portion c1 Center of side surface E1, E2 Edge portion L1 Length of first connection portion L2 Length of second connection portion t1 Thickness of first mounting plate portion t3 Thickness of third mounting plate portion S Cross-sectional area of lead-out portion ws Weld mark w0, wd Width

Claims (11)

a magnetic core including a magnetic material and having a top surface, a bottom surface, and a side surface connected to the top surface and the bottom surface;
a coil element including a coil portion embedded in the magnetic core and an extraction portion connected to an end of the coil portion and extracted from the side surface to the outside of the magnetic core;
Electrode members disposed on the side and bottom surfaces;
a connection portion that connects the lead portion and the electrode member;
Equipped with
The lead portion extends along the side surface outside the magnetic core,
the electrode member has a bottom plate portion disposed along the bottom surface, an opposing side plate portion connected to the bottom plate portion and facing the side surface with a gap therebetween with the lead portion interposed therebetween, and a first disposed plate portion connected to the opposing side plate portion and extending in a direction toward the side surface,
The first mounting plate portion has an edge portion, at least a part of which contacts the drawer portion along an extension direction of the drawer portion,
The connection portion includes a first connection portion in which the lead-out portion and an edge portion of the first mounting plate portion are welded to each other,
When the length of the first connection portion in the extension direction of the draw-out portion is L1, the thickness of the first arrangement plate portion is t1, and the cross-sectional area of the draw-out portion is S,
L1≧(S×0.2)/t1
The relationship is
Inductor. The first connection portion is formed along the extension direction of the lead portion.
2. The inductor of claim 1. The first connection portion is formed by connecting a plurality of weld marks.
3. The inductor according to claim 1 or 2. The lead portion has a covered region having an insulating coating on an outer circumferential surface of the lead portion, and a bare region not having the insulating coating,
The connection portion is formed in the exposed region.
The inductor according to any one of claims 1 to 3. When the lead-out portion is viewed in cross section,
The length of the exposed region on the outer periphery of the lead portion is 30% or more and 70% or less of the outer periphery of the lead portion.
5. The inductor according to claim 4. When viewed from a direction perpendicular to the side surface,
The width of the opposing side plate portion is wider than the width of the drawer portion.
The inductor according to any one of claims 1 to 5. The electrode member further includes a second mounting plate portion that faces the first mounting plate portion with the lead portion therebetween and is connected to the opposing side plate portion and extends in a direction toward the side surface.
The inductor according to any one of claims 1 to 6. a magnetic core including a magnetic material and having a top surface, a bottom surface, and a side surface connected to the top surface and the bottom surface;
a coil element including a coil portion embedded in the magnetic core and an extraction portion connected to an end of the coil portion and extracted from the side surface to the outside of the magnetic core;
Electrode members disposed on the side and bottom surfaces;
a connection portion that connects the lead portion and the electrode member;
Equipped with
The lead portion extends along the side surface outside the magnetic core,
the electrode member has a bottom plate portion disposed along the bottom surface, an opposing side plate portion connected to the bottom plate portion and facing the side surface with a gap therebetween with the lead portion interposed therebetween, and a first disposed plate portion connected to the opposing side plate portion and extending in a direction toward the side surface,
The first mounting plate portion has an edge portion, at least a part of which contacts the drawer portion along an extension direction of the drawer portion,
The connection portion includes a first connection portion in which the lead-out portion and an edge portion of the first mounting plate portion are welded to each other,
the electrode member further includes a second mounting plate portion disposed opposite the first mounting plate portion with the lead portion interposed therebetween, connected to the opposing side plate portion, and extending in a direction toward the side surface,
The opposing side plate portion has a first region having a width greater than that of the drawn-out portion, and a second region having a width greater than that of the drawn-out portion and smaller than that of the first region,
the first and second plate portions are connected to the first region of the opposing side plate portion,
the electrode member further includes a third disposed plate portion connected to the second region of the opposing side plate portion, opposed to the first disposed plate portion with the lead portion therebetween, and disposed extending in a direction toward the side surface,
the third mounting plate portion has an edge portion, at least a portion of which contacts the drawer portion along an extension direction of the drawer portion,
The connection portion further includes a second connection portion in which the lead-out portion and an edge portion of the third installation plate portion are welded to each other,
When the length of the first connection portion in the extension direction of the draw-out portion is L1, the thickness of the first arrangement plate portion is t1, and the cross-sectional area of the draw-out portion is S,
L1≧(S×0.15)/t1
The relationship is as follows:
When the length of the second connection portion in the extension direction of the draw-out portion is L2 and the thickness of the third installation plate portion is t3,
L2≧(S×0.05)/t3
The relationship is
Inductor. The drawer portion extends along a direction connecting the bottom surface and the top surface.
The inductor according to any one of claims 1 to 8 . the lead-out portion includes a first lead-out portion connected to one of the ends of the coil portion and a second lead-out portion connected to the other end of the coil portion,
The first extension portion is extended from a position on the top surface side that is higher than the height of a center of the side surface and extends toward the bottom surface side,
The second extension portion is extended from a position on the bottom surface side higher than the height of the center of the side surface and extends toward the top surface side.
10. The inductor of claim 9 . the lead-out portion includes a first lead-out portion connected to one of the ends of the coil portion and a second lead-out portion connected to the other end of the coil portion,
Each of the first and second drawer portions is drawn out from a position on the bottom surface side that is higher than the height of the center of the side surface and extends toward the top surface side.
11. The inductor of claim 10 .

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