Inductor

Abstract

This inductor (100) comprises: a magnetic core (10) having side surfaces (13a-13d); a coil element having a pull-out part (22) that is pulled from the side surface (13c) to outside of the magnetic core (10); and a plate-shaped electrode member (30) that is disposed on the side surface (13d) and a bottom surface (11), and is electrically connected to the coil element. The magnetic core (10) has a convex part (131d) that protrudes in a direction perpendicular to at least one of the side surface (13d) and a top surface (12), and a recess part (132d) that surrounds the convex part (131d) and is recessed inside the magnetic core (10) from the convex part (131d), and the electrode member (30) has a locking part (38) having an opening (38a) that penetrates the electrode member (30) in the thickness direction corresponding to the convex part (131d), the locking part (38) being locked to a locking surface (135d) that connects the convex part (131d) and the recess part (132d) by entering the recess part (132d).

Description

Technical Field

[0001] The present disclosure relates to an inductor.

Background Art

[0002] An inductor, which is a passive element that stores electrical energy as magnetic energy, is used, for example, in a DC-DC converter device or the like for the purpose of boosting and bucking a power supply voltage and smoothing a direct current. The inductor is mounted on the surface of, for example, a circuit board. For example, Patent Document 1 discloses an inductor including a main body portion containing a magnetic material, a coil element disposed inside the main body portion, and a terminal fitting connected to the coil element. In the inductor described in Patent Document 1, the terminal fitting is attached to the main body portion with an adhesive, and the terminal fitting and the tip of the coil element exposed from the main body portion are welded.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional inductor, the connection reliability between an electrode member, which is a terminal fitting, and a magnetic core may be low depending on the usage environment, and thus the reliability of the inductor may be low. In view of the above, an object of the present disclosure is to improve the reliability of an inductor.

Means for Solving the Problems

[0005] An inductor according to one aspect of the present disclosure comprises a magnetic core containing a magnetic material and having a bottom surface, a top surface, and a side surface connected to the bottom surface and the top surface; a coil element having a coil portion embedded in the magnetic core and a lead portion connected to the end of the coil portion and drawn out from the side surface to the outside of the magnetic core; and a plate-shaped electrode member disposed on the side surface and the bottom surface and electrically connected to the coil element via the lead portion, wherein the magnetic core has a convex portion projecting in a direction perpendicular to at least one of the side surface and the top surface, and a recess surrounding the convex portion and being recessed in the magnetic core more recessed than the convex portion; and the electrode member has a locking portion having an opening that penetrates the electrode member in the thickness direction corresponding to the convex portion, and the locking portion is engaged with a locking surface that connects the convex portion and the recess by entering into the recess. [Effects of the Invention]

[0006] According to this disclosure, the reliability of the inductor can be improved. [Brief explanation of the drawing]

[0007] [Figure 1] This is a first perspective view of an inductor according to an embodiment. [Figure 2] This is a second perspective view of the inductor according to the embodiment. [Figure 3] This is a top view of a part of the inductor according to the embodiment. [Figure 4] This is a side view of a part of the inductor according to an embodiment. [Figure 5] This is another side view of a part of the inductor according to the embodiment. [Figure 6] This figure illustrates the protrusion of an inductor according to a modified embodiment. [Modes for carrying out the invention]

[0008] (Background leading to this disclosure) As described in Patent Document 1 above, in a structure where the terminal fitting is fixed to the main body only with adhesive, vibrations can cause the relatively heavy magnetic core to shake, potentially causing the magnetic core to detach from the electrode member soldered to the circuit board, and the welded portion to come loose as well.

[0009] This disclosure has the following configuration to improve the reliability of the inductor. The embodiments will be described in more detail below with reference to the drawings.

[0010] The embodiments described below are all specific examples of this disclosure. The numerical values, shapes, materials, components, arrangement positions of components, connection configurations, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0011] Furthermore, in this specification, terms indicating relationships between elements such as parallelism, terms indicating the shape of elements such as rectangular prisms, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0012] Furthermore, each figure is a schematic diagram that has been appropriately emphasized, omitted, or had its proportions adjusted to illustrate this disclosure, and is not necessarily a strict representation; it may differ from the actual shape, positional relationships, and proportions. In each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0013] Furthermore, each figure shows the X, Y, and Z axes, representing three mutually orthogonal directions, and these axes and the axial directions along them are used for explanatory purposes as needed. Note that these axes are included for explanatory purposes only and do not limit the direction or orientation in which the inductor is used.

[0014] In addition, in this specification, the terms "top surface" and "bottom surface" in the configuration of the inductor do not refer to the top surface (the vertically upward side surface) and the bottom surface (the vertically downward side surface) in the absolute spatial recognition, but are used as terms defined by the relative positional relationship of the components of the inductor.

[0015] (Embodiment) [Configuration] The configuration of the inductor according to the embodiment will be described. An inductor is a passive element that stores electrical energy flowing through a coil element as magnetic energy.

[0016] FIG. 1 is a first perspective view of the inductor according to the embodiment as viewed from the top surface side. FIG. 2 is a second perspective view of the inductor shown in FIG. 1 as viewed from the bottom surface side.

[0017] As shown in FIGS. 1 and 2, the inductor 100 includes a magnetic core 10, a coil element having a coil portion 21 and a lead portion 22, an electrode member 30 which is an external terminal, and a connection portion connecting the lead portion 22 and the electrode member 30.

[0018] In the following description, mainly, the plus half of the X-axis in the inductor 100 will be described, but the minus half of the X-axis in the inductor 100 also has the same structure as the plus half of the X-axis in the inductor 100, and the same description applies.

[0019] 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-shaped compacted magnetic core. Note that the magnetic core 10 can be molded into an arbitrary shape by molding. That is, an inductor 100 of an arbitrary shape can be realized depending on the shape at the time of molding the magnetic core 10. In the magnetic core 10 of the present 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.

[0020] The magnetic core 10 is the outer shell portion of the inductor 100 and covers a part of the coil element (coil portion 21). The magnetic core 10 contains a magnetic material and is a compacted magnetic core made of, for example, metallic magnetic powder and resin material. The magnetic core 10 can be formed using a magnetic material. Ferrite may be used as the magnetic material, or other magnetic materials may be used. For the metallic magnetic powder, particulate materials having a predetermined elemental composition such as Fe-Si-Al, Fe-Si, Fe-Si-Cr, or Fe-Si-Cr-B are used. For the resin material, a material that can maintain a certain shape by insulating the particles of the metallic magnetic powder while binding them together is selected, such as a silicone resin.

[0021] The magnetic core 10 is, for example, shaped like a rectangular parallelepiped. The magnetic core 10 has a base surface 11, a top surface 12 facing away from the base surface 11, and four sides 13a, 13b, 13c, and 13d that connect the base surface 11 and the top surface 12. Sides 13a and 13b are aligned in the X-axis direction and face away from each other. Side 13c (also called the second side) and side 13d (also called the first side) are aligned in the Y-axis direction and face away from each other. The base surface 11, the top surface 12, and the sides 13a, 13b, 13c, and 13d are each substantially flat planes. The pairs of the base surface 11 and the top surface 12, the pairs of side 13a and 13b, and the pairs of side 13c and 13d are each pairs of planes that are in a parallel positional relationship. The bottom surface 11 and the top surface 12, and the sides 13a, 13b, 13c, and 13d extend in intersecting directions, specifically in orthogonal directions. Also, the sides 13a and 13b, and the sides 13c and 13d extend in intersecting directions, specifically in orthogonal directions.

[0022] The coil element has a coil portion 21 consisting of a single wire embedded in the magnetic core 10, and a plurality of lead portions 22 corresponding to both ends of the wire and exposed to the outside of the magnetic core 10. In other words, the coil element according to this embodiment consists of one coil portion 21 and two lead portions 22. In Figure 1, the embedded coil portion 21 is shown by a dashed line.

[0023] The coil element is composed of, for example, a conductor. The conductor is composed of a metal wire made of a metallic material selected from, for example, metals such as aluminum, copper, silver, and gold, alloys containing one or more of these metals, and materials made of metals or alloys and other substances, and an insulating coating covering the metal wire. Specifically, the conductor is, for example, a copper wire covered with an insulating coating. The coil section 21 and the lead section 22 are, for example, designations given to the respective parts formed by processing a single component made of the same material.

[0024] The coil portion 21 is the part covered by the magnetic core 10. The coil portion 21 is composed of a wound conductor and functions as a coil. There are no particular limitations on the number of turns of the coil portion 21; for example, it can be selected appropriately from 0.5 turns to 10 turns, depending on the performance required of the inductor 100 and constraints such as the size of the magnetic core 10. The conductor constituting the coil portion 21 has a cross-section that is, for example, a flat rectangular wire with each side measuring 3.2 mm × 2.4 mm. The coil portion 21 is wound vertically with the surfaces including the long side of the conductor's cross-section overlapping. This coil portion 21 is embedded in the magnetic core 10 such that the winding axis of the coil portion 21 is aligned with the direction (Z-axis direction) connecting the bottom surface 11 and the top surface 12.

[0025] The coil portion 21 has an end (not shown) that connects from the wound portion to the side surface 13c of the magnetic core 10. Of the ends of the coil portion 21, one end is positioned on the positive side of the X-axis, which is to the right and outward of the winding axis when viewed from a direction perpendicular to the side surface 13c, and the other end is positioned on the negative side of the X-axis, which is to the left and outward of the winding axis. Furthermore, when viewed from a direction perpendicular to the side surface 13c, the ends of the coil portion 21 are positioned at a height closer to the bottom surface 11 than the center of the side surface 13c, and are at the same height from the bottom surface 11.

[0026] The extension portion 22 is connected to the end of the coil portion 21, extends outward from the side surface 13c of the magnetic core 10, and extends along the side plate portion 35 or the side surface 13c. Specifically, the extension portion 22 is extended from a height closer to the bottom surface 11 than the center of the side surface 13c, the surface including the long side of the cross-section of the extension portion 22 bends so that it faces the side surface 13c and is parallel to the side plate portion 35 of the electrode member 30, extends in the direction connecting the bottom surface 11 and the top surface 12 (Z-axis direction), and is terminated before reaching the end on the top surface 12 side. In this embodiment, the extension portion 22 is extended from one of the four side surfaces 13c.

[0027] As shown in Figures 1 and 2, the electrode members 30 are positioned outside the magnetic core 10 (for example, on the bottom surface 11 side and on the side surfaces 13c and 13d) and are electrically connected to the lead-out sections 22 via connecting parts. The electrode members 30 are provided corresponding to each of the two lead-out sections 22. The electrode members 30 include a conductive material and are composed of, for example, a metal plate. The metal plate is 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 consisting of metals or alloys and other substances.

[0028] The electrode member 30 has a bottom plate portion 31 positioned on the bottom surface 11 side of the magnetic core 10, a side plate portion 35 connected to the bottom plate portion 31 and positioned on the side surface 13c side of the magnetic core 10, and a locking portion 38 connected to the bottom plate portion 31 and positioned on the side surface 13d side of the magnetic core 10. The side plate portion 35 has a first protruding plate portion 36i and a second protruding plate portion 36ii connected to the side plate portion 35. The bottom plate portion 31, the side plate portion 35, the locking portion 38, the first protruding plate portion 36i, and the second protruding plate portion 36ii are, for example, designations given to each part formed by processing a single member made of the same material.

[0029] The bottom plate portion 31 is positioned 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 may be fixed to the magnetic core 10 via adhesive. The bottom plate portion 31 is joined to the circuit board by solder when the inductor 100 is mounted on the circuit board. The bottom plate portion 31 may have a portion that protrudes outward from the magnetic core 10 when viewed from the top surface 12 side (plan view in the Z-axis direction), which is preferable because it allows the protruding portion to be heated more easily by the preheating of the reflow oven when soldering in a reflow oven, improving solderability.

[0030] The side plate portion 35 is connected to the bottom plate portion 31 and is positioned along the side surface 13c of the magnetic core 10. In this embodiment, the side plate portion 35 extends from the bottom plate portion 31 toward the top surface 12. The side plate portion 35 also has an opening that penetrates in the thickness direction, through which the drawer portion 22 can pass, and the drawer portion 22 is passed through this opening and positioned along the side surface 13c. When viewed from the X-axis direction, the side plate portion 35 is positioned between the side surface 13c of the magnetic core 10 and the drawer portion 22, and when viewed from the Y-axis direction, it is positioned around the drawer portion 22. The side plate portion 35 is positioned corresponding to one of the four side surfaces 13c. The side plate portion 35 may be fixed to the magnetic core 10 via adhesive.

[0031] The first protruding plate portion 36i and the second protruding plate portion 36ii are connected to the opening edge of the side plate portion 35 and protrude away from the side surface 13c of the magnetic core 10. The first protruding plate portion 36i and the second protruding plate portion 36ii protrude perpendicularly to the side plate portion 35, or from the opening edge of the side plate portion 35 toward the drawer portion 22. In addition, the first protruding plate portion 36i and the second protruding plate portion 36ii have edges located on the opposite side from the side surface 13c, and at least a portion of these edges is in contact with the drawer portion 22 along the extending direction of the drawer portion 22.

[0032] The lead-out portion 22 has a covered area on its outer circumferential surface that has an insulating coating, and an exposed area where the metal wire is exposed without an insulating coating. All or most of the exposed area is located on the side where the first protruding plate portion 36i and the second protruding plate portion 36ii are located.

[0033] The edges of the first protruding plate portion 36i and the second protruding plate portion 36ii are in contact with the exposed region. A connection portion is formed at the location where the exposed region and the edges of the first protruding plate portion 36i and the second protruding plate portion 36ii are in contact.

[0034] As shown in Figure 1, the connection is formed by welding the pull-out portion 22 to the edges of the first protruding plate portion 36i and the second protruding plate portion 36ii. For example, such a connection is 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. The plurality of weld marks ws may all be continuously connected, or some of the weld marks ws may be continuously connected.

[0035] The length of the connection portion in the extension direction of the extension portion 22 is, for example, greater than the length of the long side in the cross-section of the conductor of the extension portion 22, and less than or equal to five times the length of the long side. The longer the length of the connection portion, the larger the cross-sectional area of ​​the welded area.

[0036] In this embodiment, the edges of the first protruding plate portion 36i and the second protruding plate portion 36ii are in contact along the extending direction of the lead portion 22. Therefore, it is possible to increase the length of the connection portion formed by welding the edge portion and the lead portion 22. This makes it possible to increase the cross-sectional area of ​​the connection portion connecting the coil element 20 and the electrode member 30, thereby improving the reliability of the connection. In addition, since the cross-sectional area of ​​the current path in the connection portion can be increased, the DC resistance can be reduced, thereby improving the reliability of the inductor. Furthermore, since the cross-sectional area of ​​the current path in the connection portion can be increased, it is possible to suppress the temperature rise that occurs when the inductor is energized, thereby improving the reliability of the inductor.

[0037] The following explanation primarily describes the negative half of the X-axis in inductor 100, but the positive half of the X-axis in inductor 100 has a similar structure to the negative half of the X-axis inductor 100, and the same explanation applies to it.

[0038] As shown in Figure 2, the electrode member 30 has a locking portion 38 along the side surface 13d. More specifically, the locking portion 38 is connected to the bottom plate portion 31 and is positioned along the side surface 13d of the magnetic core 10. In this embodiment, the locking portion 38 extends from the bottom plate portion 31 toward the top surface 12 and is positioned between the outermost and innermost parts of the side surface 13d of the magnetic core 10 when viewed from the X-axis direction. The locking portion 38 is positioned corresponding to one of the four side surfaces 13d. An opening 38a is formed in the locking portion 38. The opening 38a is a rectangular through-hole provided that penetrates the electrode member 30 in the thickness direction (in this case, the Y-axis direction). The opening 38a corresponds to a protrusion 131d formed on the side surface 13d, and the locking portion 38 is positioned so that the protrusion 131d penetrates the opening 38a. The locking portion 38 may be fixed to the magnetic core 10 via adhesive. Such a locking portion 38 is used to fix the magnetic core 10 and the electrode member 30 by locking the side surface of the protrusion 131d on the top surface 12 side with the inner surface of the opening 38a on the top surface 12 side (facing the bottom surface 11 side). In other words, the electrode member 30 is fixed to the magnetic core 10 by locking to the protrusion 131d by the locking portion 38, welding at the connection portion, and (if applicable, adhesion of the bottom plate portion 31, the side plate portion 35, and the locking portion 38). Such a protrusion 131d is formed, for example, on the bottom surface 11 side of the center of the magnetic core 10, as shown in the figure.

[0039] Here, Figure 3 is a top view of a part of the inductor according to the embodiment. In Figure 3, a part of the inductor 100 is shown from the top surface 12 side (plan view in the Z-axis direction), centered on the locking portion 38. As shown in Figure 3, the protrusion 131d has a shape that protrudes vertically from the side (here, in the positive Y-axis direction). Around the protrusion 131d, a recess 132d is formed so as to surround the protrusion 131d. The locking portion 38 is positioned inside the magnetic core 10 beyond the outermost surface of the protrusion 131d because the protrusion 131d penetrates the opening 38a. The locking portion 38 then contacts the recess 132d to prevent it from penetrating further inside the magnetic core 10. At a position corresponding to the locking surface 135d, which is the side surface of the protrusion 131d on the top surface 12 side to which the locking portion 38 is locked, a part 134d of the recess 132d is further recessed into the magnetic core 10.

[0040] Therefore, the recess 132d has a portion 134d that is recessed further into the magnetic core 10 than the other portion 133d. The portion 134d of the recess 132d has a curved surface in which the depth of the recess into the magnetic core 10 changes smoothly. The locking portion 38 has a crimping portion 38b that is bent into a smooth curved shape to follow the curved surface. The crimping portion 38b is bent so as to fit into the portion 134d of the recess 132d, improving the resistance of the locking portion 38 to tension in the Z-axis direction. Furthermore, as shown in Figure 4, the rectangular shape of the opening 38a is deformed by the provision of the crimping portion 38b.

[0041] Figure 4 is a side view of a part of the inductor according to the embodiment. Figure 4 shows a part of the inductor 100 as seen from the side 13d (plan view in the Y-axis direction), centered on the locking portion 38. As shown in Figure 4, one side of the rectangular shape of the opening 38a corresponding to the locking surface 135d is tightened and narrowed in the X-axis direction, becoming shorter than the opposite side. Specifically, if the length of the side corresponding to the locking surface 135d is L5, then L5 is shorter than the length L6 of the opposite side. As a result, the rectangular shape of the opening 38a becomes a so-called trapezoidal shape, and the inner surface on the side 13a side and the inner surface on the side 13b side of the opening 38a contact the convex portion 131d, thereby improving the resistance of the locking portion 38 to displacement in the Y-axis direction.

[0042] Furthermore, in order to ensure secure locking by the locking portion 38, the length of the locking surface 135d of the protrusion 131d in the direction along the plate surface of the electrode member 30 is sufficiently long. For example, the locking portion 38 is designed such that the length L5 of the side corresponding to the locking surface 135d is sufficiently large relative to the thickness L4 of the locking portion 38 (thickness of the electrode member 30) shown in Figure 3. L5 is, for example, more than twice the length of L4.

[0043] Returning to the explanation of Figure 2, the bottom plate portion 31 has a bottom crimping portion 31a. The bottom crimping portion 31a tightens and narrows the length of the bottom plate portion 31 in the Y-axis direction, thereby making the locking of the locking portion 38 to the protrusion 131d stronger. In order to form the bottom crimping portion 31a on the bottom surface 11, the magnetic core 10 has a bottom recess 11a formed inside the magnetic core 10 at a position on the bottom surface 11 that overlaps with the bottom plate portion 31 of the electrode member 30. The bottom plate portion 31 then enters the inside of the magnetic core 10 along the concave shape of the bottom recess 11a and is curved, thereby forming the bottom crimping portion 31a.

[0044] The width of the electrode member 30 in the bottom plate portion 31 (the length of the electrode member 30 in the X-axis direction that extends in the Y-axis direction) is such that, for example, the width L2 at the position of the bottom crimping portion 31a is narrower than the rest (for example, length L1). As a result, the bottom crimping portion 31a can be formed with less stress, and the reduction in the length of the bottom plate portion 31 when the bottom crimping portion 31a is formed is efficiently transmitted to the crimping portion 38b, etc., resulting in a stronger fixation of the electrode member 30 to the magnetic core 10.

[0045] Here, Figure 5 is another side view of a part of the inductor according to the embodiment. Figure 5 shows a part of the inductor 100 as seen from the side 13b (plan view in the X-axis direction), focusing on the locking portion 38 and the bottom plate portion 31. As shown in Figure 5, the magnetic core 10 has a recessed void portion 11b formed inside the magnetic core 10 at the boundary connecting the bottom surface 11 and the side surface 13d, and at a position overlapping with the electrode member 30. The formation of the void portion 11b provides play, making it less likely for the narrowing of the bottom plate portion 31 by the bottom crimping portion 31a to be hindered at the boundary portion, thus making it possible to more efficiently apply the effect of the bottom crimping portion 31a to the locking portion 38.

[0046] Returning to the explanation of Figure 2, the area of ​​the bottom plate portion 31 on the side 13c side (part 31b in the figure) relative to the bottom crimp portion 31a is larger than the area of ​​the side 13d side (part 31c in the figure) relative to the bottom crimp portion 31a. If the width of the bottom crimp portion 31a is narrowed, a portion with high electrical resistance will be formed between the portion 31b side and the portion 31c side. Therefore, by ensuring a larger portion 31b on the side of the drawer portion 22 relative to this portion with high electrical resistance, it is possible to suppress the deterioration of the current-carrying characteristics.

[0047] [Manufacturing method] Next, the manufacturing method of the inductor 100 described above will be explained. The inductor 100 according to the embodiment is manufactured as follows. Note that the manufacturing method of the inductor 100 is not limited to the following example.

[0048] In the manufacturing method of the inductor 100, the first step is to pressure-molde the magnetic core 10 together with the coil element. This step is performed by placing the coil element having the coil portion 21 into a molding die and pressure-molding the compacted magnetic core. The pressure applied during pressure molding is, for example, 5 tons / cm². 2 The thermosetting temperature is, for example, 185°C. After pressure molding, the exposed pull-out portion 22, which is not covered by the magnetic core 10, protrudes perpendicularly to the side surface 13c of the magnetic core 10, for example.

[0049] Next, a process is carried out to form an exposed region on the outer surface of the pull-out portion 22. The exposed region is formed by removing a portion of the insulating film after pressure molding using laser irradiation or the like.

[0050] Next, the extension portion 22 exposed from the magnetic core 10 is bent along the side surface 13c. Specifically, the extension portion 22 is shaped to extend from its base located on the side surface 13c in the direction connecting the bottom surface 11 and the top surface 12, and the surface including the long side of the cross-section of the extension portion 22 faces the side surface 13c.

[0051] Next, a process is carried out to prepare an electrode member 30 having a bottom plate portion 31, a side plate portion 35, and a locking portion 38 by punching and bending a metal material sheet. In this process, the first protruding plate portion 36i and the second protruding plate portion 36ii of the side plate portion 35 are bent in advance in a direction away from the side surface 13c of the magnetic core 10. It is also preferable to pre-bend the boundary between the bottom plate portion 31 and the side plate portion 35, and the boundary between the bottom plate portion 31 and the locking portion 38, so that the internal angle is approximately 100° to 110°.

[0052] Next, the electrode members 30 are positioned on the magnetic core 10 as shown in Figure 1. The bottom plate portion 31 is placed on the bottom surface 11 of the magnetic core 10, the side plate portion 35 is bent along the side surface 13c of the magnetic core 10, and the locking portion 38 is bent along the side surface 13d of the magnetic core 10. At this time, the pull-out portion 22 is passed through the opening of the side plate portion 35, and the pull-out portion 22 is in contact with the edges of the first protruding plate portion 36i and the second protruding plate portion 36ii. Also, the protrusion portion 131d is passed through the opening 38a of the locking portion 38. Furthermore, if any or all of the bottom plate portion 31, side plate portion 35, and locking portion 38 of the electrode members 30 are to be bonded to the magnetic core 10, a thermosetting adhesive that is viscous when uncured is applied to the parts where the electrode members 30 and the magnetic core 10 come into contact. The adhesive is not cured in this step, but in a later step described later.

[0053] Next, the edges of the first protruding plate portion 36i and the second protruding plate portion 36ii are welded to the pull-out portion 22 by laser seam welding or the like. Specifically, a connection portion is formed along the extension direction of the pull-out portion 22. The weld mark ws formed at the connection portion is circular in shape and is formed, for example, by rotating the spot of the laser beam by a predetermined radius. At this time, welding is performed with the bottom plate portion 31 of the electrode member 30 pressed against the bottom surface 11 of the magnetic core 10, the side plate portion 35 of the electrode member 30 pressed against the side surface 13c of the magnetic core 10, and the locking portion 38 of the electrode member 30 pressed against the side surface 13d of the magnetic core 10. As a result, the pull-out portion 22 and the electrode member 30 are electrically connected, and the electrode member 30 is mechanically fixed to the magnetic core 10.

[0054] Next, the locking portion 38 is bent so that it fits into a part 134d of the recess 132d of the magnetic core 10. This forms a crimped portion 38b and narrows the opening 38a of the locking portion 38.

[0055] Next, the bottom plate portion 31 is bent so that it fits into the bottom recess 11a of the magnetic core 10. This forms the bottom crimp portion 31a and narrows the electrode member 30. By narrowing the electrode member 30 in this order, starting with the crimp portion 38b and then the bottom crimp portion 31a, the entire electrode member 30 is tightened against the magnetic core 10, firmly fixing the electrode member 30 and the magnetic core 10 together. If the electrode member 30 and the magnetic core 10 are to be bonded together, a heat treatment is performed after this step to cure the adhesive. By narrowing the area using the crimping portion 38b and the bottom crimping portion 31a, followed by curing of the adhesive, the viscosity of the uncured adhesive allows for efficient tightening of the electrode member 30 to the magnetic core 10 by the crimping portion 38b and the bottom crimping portion 31a until the adhesive hardens. After the adhesive hardens, the adhesive force of the adhesive further strengthens the fixing force between the electrode member 30 and the magnetic core 10. In this way, the inductor 100 is manufactured.

[0056] [Effects, etc.] As described above, the inductor 100 according to the first aspect of this embodiment includes a magnetic core 10 containing a magnetic material and having a bottom surface 11, a top surface 12, and side surfaces 13a to 13d connected to the bottom surface 11 and the top surface 12; a coil element having a coil portion 21 embedded in the magnetic core 10 and a lead portion 22 connected to the end of the coil portion 21 and extended to the outside of the magnetic core 10 from the side surface 13c; and a plate arranged on the side surfaces 13c, 13d and the bottom surface 11 and electrically connected to the coil element via the lead portion 22. The magnetic core 10 comprises a shaped electrode member 30, and the magnetic core 10 has a convex portion 131d that protrudes in a direction perpendicular to at least one of the side surface 13d and the top surface 12, and a recess 132d that surrounds the convex portion 131d and is recessed in the magnetic core 10 more recessed than the convex portion 131d, and the electrode member 30 has a locking portion 38 that has an opening 38a that penetrates the electrode member 30 in the thickness direction corresponding to the convex portion 131d, and the locking portion 38 that fits into the recess 132d and locks into a locking surface 135d that connects the convex portion 131d and the recess 132d.

[0057] In such an inductor 100, the locking portion 38 of the electrode member 30 is locked to the protrusion 131d of the magnetic core 10, thereby preventing the magnetic core 10 from falling out of the electrode member 30. In particular, the force acting in the direction that would cause the magnetic core 10 to move away from the electrode member 30 in the direction in which the locking surface 135d and the inner surface of the opening 38a overlap is suppressed by the locking, thus enabling the realization of an inductor 100 with high resistance to the direction in which the locking surface 135d and the inner surface of the opening 38a overlap. In this way, the detachment of the magnetic core 10 from the electrode member 30 is suppressed, and the connection reliability between the electrode member 30 and the coil element partially embedded in the magnetic core 10 is increased, resulting in a more reliable inductor.

[0058] Furthermore, the inductor 100 according to the second aspect of this disclosure is the inductor 100 according to the first aspect, wherein the protrusion 131d protrudes in a direction perpendicular to the side surface 13d.

[0059] According to this, an inductor 100 with high resistance to the direction parallel to the side surface 13d can be realized.

[0060] Furthermore, the inductor 100 according to the third aspect of this disclosure is the inductor 100 according to the second aspect, wherein the protrusion 131d protrudes in a direction perpendicular to the side surface 13d and is formed on the bottom surface 11 side of the center of the magnetic core 10 in the direction connecting the bottom surface 11 and the top surface 12.

[0061] According to this, since the electrode member 30 is fixed to the bottom surface 11 side of the center of gravity of the magnetic core 10, the self-resonant frequency of the inductor 100 with respect to vibration can be increased. Therefore, the magnetic core 10 becomes less likely to vibrate relative to the electrode member 30, and the detachment of the magnetic core 10 from the electrode member 30 is suppressed.

[0062] The inductor 100A relating to the fourth aspect will be described later.

[0063] Furthermore, the inductor 100 according to the fifth aspect of this disclosure has a locking surface 135d of the protrusion 131d such that the length in the direction along the plate surface of the electrode member 30 is at least twice the length in the thickness direction of the electrode member 30, and otherwise it is the same as the inductor 100 described in the first to third aspects or the inductor 100A described in the fourth aspect.

[0064] According to this, in fixing the electrode member 30 to the magnetic core 10 by locking it to the protrusion 131d via the locking portion 38, sufficient resistance can be provided to prevent damage to the protrusion 131d on the side surface 13d.

[0065] Furthermore, the inductor 100 according to the sixth aspect of this disclosure has a portion 134d of the recess 132d that is directly connected to the locking surface 135d, which is recessed further into the magnetic core 10 than the other portion 133d, and the locking portion 38 has a crimped portion 38b that is bent to correspond to the portion 134d of the recess 132d, and the crimped portion 38b is inserted further into the magnetic core 10 than the other portion 133d of the recess 132d, and otherwise it is the same as the inductor 100 described in the first to third and fifth aspects, or the inductor 100A described in the fourth aspect.

[0066] According to this, the area of ​​the inner surface of the opening 38a that is locked to the locking surface 135d can be partially expanded in the depth direction of 134d. Furthermore, since the end side of the locking portion 38 is constructed three-dimensionally more than the opening 38a, rigidity is improved, so an inductor that can withstand even larger forces that could cause the magnetic core 10 to fall out can be realized.

[0067] Furthermore, the inductor 100 according to the seventh aspect of this disclosure is the inductor 100 according to the sixth aspect, wherein a portion 134d of the recess 132d has a curved surface in which the depth to the inside of the magnetic core 10 in the recessed shape changes smoothly, and the crimping portion 38b has a smooth curved shape that follows the curved surface.

[0068] According to this, compared to the case where the crimped portion 38b is formed by bending the electrode member 30, the electrode member 30 is less likely to be damaged at the crimped portion 38b.

[0069] Furthermore, the inductor 100 according to the eighth aspect of this disclosure is the inductor 100 according to the sixth or seventh aspect, wherein the opening 38a is rectangular in shape when viewed from the thickness direction, and the length of the side corresponding to the locking surface 135d among the four sides of the rectangular shape is shorter than the length of the side opposite to that side.

[0070] According to this, a trapezoidal opening 38a can be formed. The force applied when the locking portion 38 is locked, which causes the locking surface 135d and the inner surface of the opening 38a to overlap, can be used to align the opening 38a with the protrusion 131d. In addition, since the opening 38a can be tightened in a direction that sandwiches the protrusion 131d, it is possible to prevent the opening 38a from falling off the protrusion 131d.

[0071] Furthermore, the inductor 100 according to the ninth aspect of this disclosure has a bottom surface recess 11a in the magnetic core 10 that is concave inside the magnetic core 10 at a position on the bottom surface 11 that overlaps with the electrode member 30, and the electrode member 30 has a bottom surface crimping portion 31a that fits into the bottom surface recess 11a and is bent in accordance with the bottom surface recess 11a, and is otherwise the same as the inductor 100 described in the first to third and fifth to eighth aspects, or the inductor 100A described in the fourth aspect.

[0072] According to this, the length of the bottom plate portion 31 in the in-plane direction of the bottom surface 11 can be reduced by the bottom crimping portion 31a. As a result, the electrode member 30 can be tightened in a direction that reduces the distance between the locking portion 38 and the connection point to the pull-out portion 22, so that the locking of the locking portion 38 to the protrusion 131d can be made stronger.

[0073] Furthermore, the inductor 100 according to the tenth aspect of this disclosure is the inductor 100 according to the ninth aspect, wherein the width of the position of the bottom crimping portion 31a in the portion of the electrode member 30 that is located on the bottom surface 11 is the narrowest.

[0074] According to this, the stress required to form the bottom crimped portion 31a can be reduced.

[0075] Furthermore, the inductor 100 according to the 11th aspect of this disclosure is the inductor 100 according to the 9th or 10th aspect, wherein, among the sides 13a to 13d, the side 13d closest to the protrusion 131d is designated as the first side, and the side 13c furthest from it is designated as the second side, the lead portion 22 and the electrode member 30 are welded to the second side and electrically connected, and the area of ​​the portion of the electrode member 30 located on the bottom surface 11 on the second side is larger than the area of ​​the portion of the electrode member 30 located on the first side than the bottom crimp portion 31a.

[0076] According to this, a large electrode area can be provided on the drawer portion 22 side without having to go through a relatively high electrical resistance area due to the narrow width of the bottom crimping portion 31a.

[0077] Furthermore, the inductor 100 according to the twelfth aspect of this disclosure is the inductor 100 according to any one of the ninth to eleventh aspects, wherein the magnetic core 10 has a recessed void 11b inside the magnetic core 10 at the boundary connecting the bottom surface 11 and the side surface 13d, and at a position overlapping with the electrode member 30.

[0078] According to this, compared to the case where the gap portion 11b is not provided, the snagging when pulling the locking portion 38 towards the bottom plate portion 31 by forming the bottom crimp portion 31a can be reduced. In other words, the force that tightens the electrode member 30 in the direction that reduces the distance between the locking portion 38, which is created by the formation of the bottom crimp portion 31a, and the connection point to the pull-out portion 22 can be transmitted to the locking portion 38 with less loss.

[0079] (Modified example of the embodiment) The following describes inductors relating to modified embodiments. In the following descriptions of each modified embodiment, the differences from the embodiment will be the main focus, and the commonalities will be omitted or simplified.

[0080] [Differentiation] A modified version of the embodiment of inductor 100A will be described. In this modified version, an example will be described in which inductor 100A has a protrusion on the top surface 12 side.

[0081] Figure 6 is a diagram illustrating a modified version of the embodiment, specifically the protruding portion of the inductor. Figure 6 shows a perspective view of the X-axis positive and Y-axis positive ends of the modified inductor 100A.

[0082] The modified inductor 100A differs from the embodiment in that a protrusion 121 is formed on the top surface 12 instead of the protrusion 131d formed on the side surface 13d of the inductor 100 in the embodiment. The protrusion 121 is surrounded by a recess 122 and penetrates an opening 38d formed in a locking portion 38c that extends from the side surface 13d to the top surface 12. The locking portion 38c is locked to the protrusion 121 by the locking portion 38c being locked to the side surface of the protrusion 121 on the negative side in the Y-axis direction by the inner surface of the opening 38d on the positive side in the Y-axis direction. This makes it difficult for the locking portion 38c to come off the magnetic core 10, and the electrode member 30 and the magnetic core 10 are firmly fixed together. In this modified inductor 100A, a crimping portion 38e may also be formed. The recess 122 is further recessed into the magnetic core 10 at a position corresponding to the locking surface, which is the side surface 13c side of the protrusion 121 to which the locking portion 38c is locked. Therefore, the recess 122 has a portion that is recessed further into the magnetic core 10 than the other portions. The portion of the recess 122 has a curved surface in which the depth of the recess into the magnetic core 10 changes smoothly. The crimping portion 38e is a portion of the locking portion 38c that is bent into a smooth curved shape to follow the curved surface. The crimping portion 38e is bent so as to fit into a portion of the recess 122, improving the resistance of the locking portion 38c to tension in the Y-axis direction. Furthermore, because the crimping portion 38e is provided, the opening 38d has a trapezoidal shape when viewed from the top surface 12 side.

[0083] Thus, the inductor 100A according to the fourth aspect of this embodiment has a protrusion 121 that protrudes perpendicular to the top surface, and is otherwise the same as the inductor 100 according to the first aspect.

[0084] Such an inductor 100A can be realized as an inductor 100 with high resistance in the direction parallel to the top surface 12.

[0085] (Other embodiments, etc.) The embodiments and modified versions of the inductors, etc., described above have been explained, but the disclosure is not limited to the embodiments and modified versions described above. Without departing from the spirit of the disclosure, various modifications that a person skilled in the art could conceive of to the embodiments and modified versions, as well as other forms constructed by combining some of the components of the embodiments and modified versions, are also included in the scope of the disclosure.

[0086] In the above embodiment, an example was shown in which the bottom plate portion 31, side plate portion 35, first protruding plate portion 36i and second protruding plate portion 36ii, and locking portion 38 of the electrode member 30 are formed by processing a single member made of the same material, but the embodiment is not limited to this. For example, the electrode member 30 may be formed by connecting the bottom plate portion 31, side plate portion 35, first protruding plate portion 36i and second protruding plate portion 36ii, and locking portion 38, which are made of different members.

[0087] In the above embodiment, an example was shown in which the coil portion 21 and the lead portion 22 of the coil element are formed by processing a single member made of the same material, but the embodiment is not limited to this. The coil element may also be formed by connecting a coil portion 21 and a lead portion 22 made of different members.

[0088] In the above embodiment, an example was shown in which the conductor has a rectangular cross-section, but it is not limited to this. The conductor may have a circular cross-section, and at least a portion of the lead-out portion 22 may be flattened to facilitate connection with the electrode member 30.

[0089] In the above embodiment, the drawer portion 22 is shown as being pulled out from a height on the bottom surface 11 side of the center of the side surface 13c and extending toward the top surface 12 side, but it is not limited to this. The drawer portion 22 may also be pulled out from a height on the top surface 12 side of the center of the side surface 13c and extending toward the bottom surface 11 side. In this case, the side plate portion 35 may be interposed between the drawer portion 22 and the side surface 13c without an opening, and the edge of the side plate portion 35 may be provided with a first protruding plate portion 36i and a second protruding plate portion 36ii.

[0090] In the above embodiment, an example was shown in which the first protruding plate portion 36i and the second protruding plate portion 36ii are arranged on both sides in the extension direction of the pull-out portion 22, but the embodiment is not limited to this. The first protruding plate portion 36i and the second protruding plate portion 36ii may be arranged only on one side in the extension direction of the pull-out portion 22.

[0091] In the above embodiment, an example was shown in which the side plate portion 35 is provided with two protruding plate portions, a first protruding plate portion 36i and a second protruding plate portion 36ii, but the embodiment is not limited to this. The protruding plate portion may be one or three.

[0092] Furthermore, electrical products or circuits using the above-described inductors are also included in this disclosure. Examples of electrical products include power supply devices equipped with the above-described inductors, and various devices equipped with such power supply devices. [Industrial applicability]

[0093] The inductor relating to this disclosure is useful as an inductor for use in various devices and equipment. [Explanation of Symbols]

[0094] 10 magnetic core 11. Base 11a Bottom recess 11b Cavity 12 Top surface 13a, 13b, 13c, 13d side 21 Coil section 22 Drawer section 30 Electrode members 31 Bottom plate part 31a Bottom crimping section 31b, 31c part 35 Side plate part 36i 1st protruding plate part 36ii 2nd protruding plate part 38, 38c locking part 38a, 38d opening 38b, 38e Crimping section 100, 100A inductor 121, 131d convex part 122, 132d recess 133d Other parts 134d part 135d Locking surface ws welding marks

Claims

1. A magnetic core comprising a magnetic material and having a bottom surface, a top surface, and sides connected to the bottom surface and the top surface, A coil element having a coil portion embedded in the magnetic core, and a lead portion connected to the end of the coil portion and extended out from the side to the outside of the magnetic core, The system comprises a plate-shaped electrode member arranged on the side and bottom surfaces and electrically connected to the coil element via the pull-out portion, The magnetic core has a convex portion that protrudes perpendicularly from at least one of the side surface and the top surface, and a concave portion that surrounds the convex portion and is recessed further inside the magnetic core than the convex portion. The electrode member has a locking portion having an opening that penetrates the electrode member in the thickness direction corresponding to the protrusion, and the locking portion engages with a locking surface that connects the protrusion and the recess by engaging with the recess. Of the aforementioned recesses, a portion that is directly connected to the locking surface is recessed further into the magnetic core than the other portions. The locking portion has a crimping portion that is bent to correspond to a part of the recess, The crimped portion is positioned further inward into the magnetic core than the other parts of the recess. Inductor.

2. The aforementioned protrusions are projecting in a direction perpendicular to the side surface. The inductor according to claim 1.

3. The aforementioned protrusions project in a direction perpendicular to the side surface and are formed on the bottom side of the magnetic core in the direction connecting the bottom surface and the top surface. The inductor according to claim 2.

4. The aforementioned protrusion is projecting in a direction perpendicular to the top surface. The inductor according to claim 1.

5. In the locking surface of the protrusion, the length in the direction along the plate surface of the electrode member is at least twice the length of the electrode member in the thickness direction. The inductor according to claim 1.

6. A magnetic core comprising a magnetic material, having a bottom surface, a top surface, and sides connected to the bottom surface and the top surface, A coil element having a coil portion embedded in the magnetic core, and a lead portion connected to the end of the coil portion and extended out from the side to the outside of the magnetic core, The system comprises a plate-shaped electrode member arranged on the side and bottom surfaces and electrically connected to the coil element via the pull-out portion, The magnetic core has a convex portion that protrudes perpendicularly from at least one of the side surface and the top surface, and a concave portion that surrounds the convex portion and is recessed further inside the magnetic core than the convex portion. The electrode member has a locking portion having an opening that penetrates the electrode member in the thickness direction corresponding to the protrusion, and the locking portion engages with a locking surface that connects the protrusion and the recess by engaging with the recess. Of the aforementioned recesses, a portion that is directly connected to the locking surface is recessed further into the magnetic core than the other portions. The locking portion has a crimping portion that is bent to correspond to a part of the recess, The crimped portion is positioned further inward of the magnetic core than the other parts of the recess. A portion of the recess has a curved surface in which the depth into the magnetic core in the concave shape changes smoothly. The crimped portion has a smooth, curved shape that conforms to the curved surface. Inductor.

7. A magnetic core comprising a magnetic material, having a bottom surface, a top surface, and sides connected to the bottom surface and the top surface, A coil element having a coil portion embedded in the magnetic core, and a lead portion connected to the end of the coil portion and extended out from the side to the outside of the magnetic core, The system comprises a plate-shaped electrode member arranged on the side and bottom surfaces and electrically connected to the coil element via the pull-out portion, The magnetic core has a convex portion that protrudes perpendicularly from at least one of the side surface and the top surface, and a concave portion that surrounds the convex portion and is recessed further inside the magnetic core than the convex portion. The electrode member has a locking portion having an opening that penetrates the electrode member in the thickness direction corresponding to the protrusion, and the locking portion engages with a locking surface that connects the protrusion and the recess by engaging with the recess. Of the aforementioned recesses, a portion that is directly connected to the locking surface is recessed further into the magnetic core than the other portions. The locking portion has a crimping portion that is bent to correspond to a part of the recess, The crimped portion is positioned further inward of the magnetic core than the other parts of the recess. The opening is rectangular in shape when viewed from the thickness direction, Of the four sides of the aforementioned quadrilateral shape, the length of the side corresponding to the locking surface is shorter than the length of the side opposite to that side. Inductor.

8. The magnetic core has a bottom surface recess that is concave inside the magnetic core at a position on the bottom surface that overlaps with the electrode member. The electrode member has a bottom crimping portion that fits into the bottom recess and is bent to correspond to the bottom recess. The inductor according to claim 1.

9. Of the electrode members, the width of the crimped portion on the bottom surface is narrowest in the portion located on the bottom surface. The inductor according to claim 8.

10. If, among the aforementioned sides, the side closest to the protrusion is designated as the first side, and the side furthest from it is designated as the second side, The aforementioned extraction portion and the electrode member are electrically connected by welding on the second side surface. Of the electrode member, the area on the second side of the portion positioned on the bottom surface, relative to the position of the bottom crimping portion, is larger than the area on the first side of the portion positioned on the bottom crimping portion. The inductor according to claim 8.

11. The magnetic core has a recessed void at the boundary connecting the bottom surface and the side surface, and at a position overlapping with the electrode member. The inductor according to any one of claims 8 to 10.

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