Coil device

Abstract

To provide a coil device which has less damage due to coating on a substrate and is excellent in reliability of mounting strength.SOLUTION: The coil device includes a magnetic core 20 having a winding core part 22 and a flange part 24,26 formed at an end along an axial center of the winding core part 22, a wire 41,42 wound around the winding core part 22, and a terminal tool 51,52 to which a lead part of the wire 41,42 is connected. The terminals 5152 and have attachment pieces 51c and 52c attached to the flange 2426, mounting pieces 51b and 52b, and intermediate connection pieces 51e and 52e. The terminal fitting other than at least a part of the mounting piece, the magnetic core, and the wire are covered with an insulating molded body 60. Parts of the mounting pieces 51b and 52b are raised along the sidewall surface 62 of the insulating molded body 60 and are separated from the sidewall surface 62 by predetermined distances.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a coil device that is suitable for being mounted on a substrate or the like. [Background technology]

[0002] In recent years, coating technology for circuit boards on which electronic components such as coil devices are mounted has advanced for the purposes of heat dissipation, waterproofing (moisture proofing), fixing (earthquake resistance), etc. However, because the entire circuit board on which the electronic components are mounted is coated, there is a risk of damage to the coil components depending on the type of coating resin.

[0003] Furthermore, as shown in Patent Document 1 below, for example, in conventional coil devices that are covered with an insulating molding, it is difficult to image the solder fillet from above the coil device using a camera, etc., making it difficult to determine whether the coil device is securely mounted, and there is a risk that the reliability of the mounting strength cannot be ensured. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 5-43510 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coil device which causes less damage to the substrate due to coating and has excellent reliability in mounting strength. [Means for solving the problem]

[0006] In order to achieve the above object, a coil device according to one aspect of the present invention comprises: a magnetic core having a winding core portion and a flange portion formed at an end of the winding core portion along an axial center; a wire wound around the winding core; A coil device having a terminal device to which a lead portion of the wire is connected, The terminal tool is an attachment piece attached to the flange; a mounting piece to be connected to the mounting pattern electrode; an intermediate connecting piece that continuously connects the mounting piece and the mounting piece, The terminal device, the magnetic core, and the wire are covered with an insulating molding, except for at least a part of the mounting piece. A portion of the mounting piece is raised along the side wall surface of the insulating molding and is spaced a predetermined distance from the side wall surface.

[0007] In this coil device, the terminal fittings (excluding at least a portion of the mounting piece), the magnetic core, and the wire are covered with an insulating molded body. Therefore, even if a coating process is performed on the substrate after the coil device is mounted on the substrate, the insulating molded body functions as a shield, preventing the coating resin from reaching the coil device's wire windings, core, or terminal connection parts. This reduces damage to the coil device caused by the substrate coating, improving the durability of the coil device. Furthermore, because the insulating molded body covers the core, it is possible to effectively prevent damage to the core, such as cracking or chipping, and thus prevent a decrease in magnetic permeability and a decrease in noise reduction effect.

[0008] Furthermore, in this coil device, a portion of the mounting piece is raised along the side wall surface of the insulating molded body and is spaced a predetermined distance from the side wall surface. This configuration ensures a sufficient mounting area for the fillet formed on the terminal fixture during mounting, and also ensures sufficient mounting strength. Furthermore, the positions of the fillet and the terminal fixture can be easily viewed (recognized) using an imaging device such as a camera, making it easier to determine whether the coil device is securely mounted, and improving the reliability of mounting strength.

[0009] Furthermore, since the rising portion of the terminal device and the side wall surface of the insulating molding are separated (there is a gap / or an air layer between them), heat transfer from the rising portion of the terminal device to the side wall surface of the insulating molding is suppressed during installation, and thermal deterioration of the insulating molding (resin molding) is suppressed.

[0010] The mounting piece is a first mounting piece that can be arranged substantially parallel to the plane of the mounting pattern electrode; The connector may further include a second mounting piece formed continuously with the first mounting piece and bent at a predetermined angle relative to the first mounting piece. The bending angle of the second mounting piece relative to the first mounting piece is preferably within a range of 87 to 93 degrees. Preferably, the second mounting piece is erected along the side wall surface of the insulating molding and is spaced a predetermined distance from the side wall surface. This configuration further improves the reliability of mounting strength and more effectively suppresses thermal degradation of the insulating molding (resin molding).

[0011] Preferably, the side wall surface of the insulating molded body is inclined relative to the first mounting piece so that the distance between the second mounting piece and the side wall surface increases with increasing distance from the first mounting piece. This configuration facilitates creating a configuration in which the second mounting piece is spaced a predetermined distance from the side wall surface of the insulating molded body. Furthermore, this configuration also makes it possible to bend the second mounting piece to a position where it contacts the side wall surface of the insulating molded body when bending the second mounting piece relative to the first mounting piece after molding the insulating molded body. After this, the second mounting piece recovers some of its bending deformation due to springback, self-aligning to a desired predetermined angle relative to the first mounting piece, and the distance from the side wall surface is also self-aligning to a predetermined distance.

[0012] Preferably, the mounting piece is attached to an outer surface other than the outer end surface of the flange located at the end along the axis. By configuring in this way, the influence of magnetic field lines emanating in a substantially perpendicular direction from the outer end surface of the flange is less likely to reach at least the mounting piece of the terminal device, making it possible to suppress the generation of eddy currents in that portion and to suppress adverse effects of eddy currents on impedance characteristics, etc. (for example, signal loss).

[0013] Furthermore, in this coil device, the outer end surface of the flange is covered with the insulating molded body, so there is no need to hold the outer end surface of the flange with a terminal fixture or the like.

[0014] The attachment piece is a bottom surface mounting piece connected to a mounting side surface of the outer surface of the flange portion; The flange may have an anti-mounting side surface located opposite the mounting side surface, and a side mounting piece connected to an intermediate side surface located between the mounting side surface and the flange.

[0015] By having a side mounting piece in addition to a bottom mounting piece, the magnetic core can be more easily positioned by the terminal tool before the insulating molding is formed, and the magnetic core can be more firmly held by the terminal tool.

[0016] At least the outer periphery of the wire wound around the core may be covered with a protective layer, which effectively protects the wound portion and the connection portion of the wire against the resin pressure when molding the insulating molded body, and effectively prevents the wire from breaking.

[0017] Preferably, at least a portion of the mounting piece of the terminal device is exposed from the insulating molding near the boundary between the intermediate connecting piece and the mounting piece. Although a portion of the intermediate connecting piece may also be exposed from the insulating molding, by having mainly the mounting piece exposed from the insulating molding and the remaining portion being covered by the insulating molding, the coil device can be more effectively protected by the insulating molding while facilitating the mounting of the coil device.

[0018] The second mounting piece may be provided on the tip side of the first mounting piece, and in this case, it is preferable that the second mounting piece is erected along the side wall surface of the insulating molding.

[0019] The mounting piece does not necessarily have to have the side mounting piece, but preferably has a bottom mounting piece connected to the mounting side of the outer surface of the flange. The intermediate connecting piece may have an extended connecting piece that is continuous and substantially flush with the bottom mounting piece, and a leg-type connecting piece that is bent toward the mounting piece at a predetermined angle relative to the extended connecting piece. It is preferable that an end of the leg-type connecting piece is continuous with the first mounting piece.

[0020] Preferably, the terminal fixture is arranged so as not to overlap the end face of the flange when viewed along the axis. This configuration effectively suppresses adverse effects of eddy currents on impedance characteristics, etc. For the same reason, it is preferable that the connecting wire portion be formed on the intermediate connecting piece so as not to overlap the end face of the flange when viewed along the axis. [Brief explanation of the drawings]

[0021] [Figure 1A] FIG. 1A is a perspective view showing a coil device according to an embodiment of the present invention. [Figure 1B] FIG. 1B is a perspective view showing a coil device according to another embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing a main part of the coil device shown in FIG. 1A. [Figure 3A] FIG. 3A is a schematic exploded view of the coil device shown in FIG. 1A. [Figure 3B] FIG. 3B is a schematic exploded view of the coil device shown in FIG. 1B. [Figure 4] FIG. 4 is a schematic cross-sectional view of the coil device shown in FIG. 3A. [Figure 5A] FIG. 5A is a side view of the coil device shown in FIG. 1A. [Figure 5B]FIG. 5B is a side view of the coil device shown in FIG. 1B. [Figure 6] FIG. 6 is a bottom view of the coil device shown in FIG. 1A. [Figure 7] FIG. 7 is a diagram showing a process of attaching the core shown in FIG. 1A to a terminal fixture. [Figure 8] 8 is an enlarged cross-sectional view of a portion of the cross section of the terminal device shown in FIG. [Figure 9A] FIG. 9A is a schematic explanatory view for generally explaining the operation of the terminal device shown in FIG. [Figure 9B] FIG. 9B is a schematic explanatory view for generally explaining the operation of the terminal device according to the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following describes the embodiments.

[0023] First embodiment The coil device 10 according to one embodiment of the present invention shown in FIG. 1A is used, for example, as a wound common mode filter, but its use is not particularly limited, and it can also be used, for example, as a balun, a dual inductor, a normal mode filter, etc.

[0024] Coil device 10 has a drum-shaped magnetic core 20, a winding section 40 consisting of first wires 41 and 42 wound around winding core section 22 of core 20, and a flat plate member 30 arranged on top of core 20. In the description of coil device 10, the axis in a plane parallel to the main mounting surface on which coil device 10 is mounted and parallel to the winding axis of winding core section 22 of core 20 is referred to as the X-axis, the axis in a plane parallel to the main mounting surface like the X-axis and perpendicular to the X-axis is referred to as the Y-axis, and the axis parallel to the normal to the main mounting surface is referred to as the Z-axis. Furthermore, the side closer to the center of coil device 10 is referred to as the inside, and the side away from the center of coil device 10 is referred to as the outside.

[0025] 2, the core 20 has a rod-shaped winding core 22 extending in the X-axis direction, and a first flange 24 and a second flange 26 as a pair of core ends provided at both ends along the X-axis of the winding core 22. The first flange 24 and the second flange 26 have approximately the same shape, and are provided on the winding core 22 so as to be approximately parallel to each other with a predetermined gap between them in the X-axis direction.

[0026] The winding core 22 is connected to the approximate center of each of the opposing surfaces of the pair of flanges 24, 26, and is integrated with the pair of flanges 24, 26. The cross-sectional shape of the winding core 22 is rectangular in this embodiment, but may also be circular, and the cross-sectional shape is not particularly limited.

[0027] 1A is preferably disposed at the upper end in the Z-axis direction of the core 20. The plate-like member 30 is preferably joined to the anti-mounting side surfaces 24b, 26b of the first flange 24 and the anti-mounting side surfaces 24b, 26b of the second flange 26 so as to bridge these surfaces.

[0028] 3A, in this embodiment, the first flange portion 24 is configured as a rectangular parallelepiped overall, and has a mounting side surface 24a that is the lower surface in the Z axis direction, an anti-mounting side surface 24b on the opposite side, an outer end surface 24c in the X axis direction, an inner surface 24d facing the winding core portion 22, and a pair of middle side surfaces 24e, 24e located on opposite sides of each other in the Y axis direction. The middle side surfaces 24e, 24e are located between the anti-mounting side surface 24b and the mounting side surface 24a to connect them, and although they are flat in this embodiment, they may be curved surfaces, and may have steps or notches formed thereon.

[0029] In this embodiment, the second flange 26 has a shape and configuration similar to that of the first flange 24, and has a mounting side surface 26a, an anti-mounting side surface 26b, an outer end surface 26c, an inner surface 26d, and intermediate side surfaces 26e, 26e. However, the second flange 26 does not necessarily have to have the same shape or configuration as the first flange 24, and may have at least a portion different therefrom.

[0030] In this embodiment, a first wire 41 and a second wire 42 are wound around the winding core portion 22 of the core 20, forming a wire wound portion 40. Lead portions 41a, 41b, 42a, and 42b (see FIG. 6) located at both ends of each wire 41 and 42 are connected by laser welding or the like to a connecting piece 51a1 of a first terminal device 51 or a connecting piece 52a1 of a second terminal device 52, which will be described later. Note that the method of connecting each lead portion 41a, 41b, 42a, and 42b (see FIG. 6) to the connecting pieces 51a1 and 52a1 is not limited to laser welding, and may be, for example, soldering, thermocompression bonding, resistance welding, ultrasonic welding, crimping, or other connections.

[0031] 3A, the coil device 10 of this embodiment has a pair of first terminal devices 51 and a pair of second terminal devices 52. The first terminal devices 51 and the second terminal devices 52 have similar components except that they have mirror-symmetrical configurations.

[0032] The first terminal device 51 and the second terminal device 52 are each made of a conductive terminal plate or the like, and are formed by bending a single piece of conductive plate material such as a metal plate. The following description will mainly focus on the first terminal device 51. The second terminal device 52 has the same configuration as the first terminal device 51, and can be described in the same way simply by replacing the reference numeral 51 with the reference numeral 52, so a partial description of the second terminal device 52 will be omitted.

[0033] The first terminal device 51 has a connecting piece 51a1, a temporary fixing piece 51a2, a mounting piece 51b, an attachment piece 51c, and an intermediate connecting piece 51d.

[0034] 1A (for example, approximately parallel if the inclination is within ±30 degrees), and a second mounting piece 51b2 formed continuously with the first mounting piece 51b1 and bent at a predetermined angle relative to the first mounting piece 51b1. The first mounting piece 51b1 is a portion that is directly connected to the land pattern electrode 80 of the substrate via the solder 70, and the second mounting piece 51b2 is a portion that is connected to the land pattern electrode 80 via a fillet (protruding portion) of the solder 70.

[0035] As shown in FIG. 3A, the mounting piece 51c has at least a bottom mounting piece 51c1 connected to one end along the Y axis of the mounting side surface 24a or 26a of the outer surface of the flange 24 or 26. Preferably, the mounting piece 51c also has a side mounting piece 51c2 bent substantially perpendicular to the bottom mounting piece 51c1, along with the bottom mounting piece 51c1. In this embodiment, the side mounting piece 51c2 is connected to one end along the Y axis of the middle side surface 24e or 26e of the outer surface of the flange 24 or 26. The mounting piece 51c and the flange 24 or 26 are connected using, for example, an adhesive or the like.

[0036] The side mounting piece 51c2 has an area that covers almost the entire Y-axis side of one of the pair of middle side surfaces 24e or 26e, but it does not necessarily have to have the same area as the middle side surface 24e or 26e and may be larger or smaller than that. For example, the side mounting piece 51c2 may be configured so that its upper end along the Z-axis reaches at least a portion of the side surface of the flat plate member 30, as shown by the two-dot chain line in FIG. 4. This configuration also makes it easier to align the flat plate member 30 with the drum-shaped core 20.

[0037] 7, the bottom mounting piece 51c1 has an inwardly protruding piece 51c3 that extends inward along the Y axis. The inwardly protruding piece 51c3 is integrated with the bottom mounting piece 51c1 on approximately the same plane and is adapted to fit closely to the mounting side surface 24a or 26a of the flange 24 or 26 together with the bottom mounting piece 51c1.

[0038] 7, when attaching the flanges 24, 26 of the core 20 to the four terminal devices 51, 52, it is preferable to push up the inner tip of the inner protruding piece 51c3 from below along the Z axis using a jig or the like (not shown). This action causes the side mounting piece 51c2 to rotate and open outward, making it easier to position the flange 24 or 26 between the side mounting piece 51c2 of the terminal device 51 and the side mounting piece 52c2 of the terminal device 52.

[0039] 3A and 6, the bottom mounting piece 51c1 is integrally provided with a temporary fastening piece 51a2. In this embodiment, the temporary fastening piece 51a2 is disposed inward along the X-axis from the inward convex piece 51c3, and unlike the inward convex piece 51c3, the temporary fastening piece 51a2 is not flush with the bottom mounting piece 51c1 but is bent in a U-shape toward the rear side (downward along the Z-axis) of the bottom mounting piece 51c1. As shown in FIG. 6, on the rear side of the bottom mounting piece 51c1, the lead portion 41a of the wire 41 or the lead portion 42b of the wire 42 is sandwiched and temporarily fixed between the temporary fastening piece 51a2 and the bottom mounting piece 51c1.

[0040] The tip of lead portion 41a of wire 41 temporarily fixed by temporary fixing piece 51a2, or the tip of lead portion 42b of wire 42, is joined to connecting piece 51a1 located outward along the X axis from temporary fixing piece 51a2. Laser welding is preferably used to join lead portions 41a or 42b, but other means, such as thermocompression bonding, may also be used.

[0041] 3A, the intermediate connecting piece 51d of this embodiment includes an extended connecting piece 51d1 that is continuous and substantially flush with the bottom mounting piece 51c1, and a leg-type connecting piece 52d2 that is bent toward the mounting piece 51b at a predetermined angle (for example, substantially perpendicular) relative to the extended connecting piece 51d1. In this embodiment, the lower end of the leg-type connecting piece 51d2 is continuous with the first mounting piece 51b1.

[0042] In this embodiment, a connecting piece 51a1 is integrally provided at the inner end of the extended connecting piece 51d1 along the Y axis. The connecting piece 51a1 is bent in a U-shape toward the rear side (downward along the Z axis) of the extended connecting piece 51d1. As shown in Fig. 6, on the rear side of the extended connecting piece 51d1, the lead portion 41a of the wire 41 or the lead portion 42b of the wire 42 is sandwiched between the connecting piece 51a1 and the extended connecting piece 51d1 and joined by laser welding or the like.

[0043] As described above, the second terminal devices 52 have a similar configuration to the first terminal devices 51 except that they are mirror images of each other, and detailed description thereof will be omitted. As shown in Fig. 3A, the pair of first terminal devices 51 are disposed at diagonal positions at the lower end positions along the Z axis of each of the flange portions 24 and 26 of the core 20, and the pair of second terminal devices 52 are disposed at another diagonal position at the lower end positions along the Z axis of each of the flange portions 24 and 26 of the core 20.

[0044] In this embodiment, the winding section 40 is composed of, but is not limited to, two wires 41 and 42. The wires 41 and 42 are, for example, coated conductors, each having a core material made of a good conductor (e.g., copper wire) covered with an insulating coating film, and are wound around the winding core section 22 in, for example, a two-layer structure. In this embodiment, the cross-sectional area of ​​the conductor portion of each of the wires 41 and 42 is the same.

[0045] In this embodiment, the first wire 41 and the second wire 42 are wound around the winding core 22 in a normal bifilar manner, but a cross portion may be formed at a predetermined position along the winding axis direction of the winding core 22.

[0046] 7 is attached to the core 20. At least the bottom mounting pieces 51c1 and 52c1 of each of the terminal devices 51 and 52 are insulated and attached to the mounting sides 24a and 26a of the flanges 24 and 26 of the core 20. In this embodiment, each of the terminal devices 51 and 52 has side mounting pieces 51c2 and 52c2, respectively, which are attached to the four middle side surfaces of the flanges 24 and 26, respectively.

[0047] Prepared are the drum-shaped core 20 with the terminal devices 51 and 52 thus manufactured, the flat plate member 30, and the wires 41 and 42. The core 20 is made of a magnetic material, and is produced by molding and sintering magnetic powder made of a magnetic material with a relatively high magnetic permeability, such as Ni-Zn ferrite, Mn-Zn ferrite, or a metallic magnetic material.

[0048] Preferably, the plate-shaped member 30 is also made of the same or a different magnetic material as the core 20, but the plate-shaped member 30 does not necessarily have to be made of a magnetic material and may be made of, for example, a non-magnetic material. The plate-shaped member 30 may also be a member formed by applying a resin. These plate-shaped members 30 preferably have a flat surface. A pickup suction member can be attached and detached to the flat surface, improving handling.

[0049] The terminal fittings 51 and 52 are made of metal terminals such as phosphor bronze, tough pitch steel, pure copper, brass, silver, gold, or a metal alloy that can be soldered. The thickness of the terminal fittings 51 and 52 is not particularly limited, but is preferably 50 to 300 μm. A plating film may be formed on one or both sides of the terminal fittings 51 and 52. The plating film may be a single-layer or multi-layer film such as a copper-plated film, a nickel-plated film, or a tin-plated film.

[0050] The wires 41 and 42 may be made of a core made of a good conductor such as copper (Cu), covered with an insulating material such as imide-modified polyurethane, and further covered on the outermost surface with a thin resin film such as polyester. The core 20 and wires 41-42 equipped with the prepared terminal devices 51 and 52 are set in a winding machine, and the wires 41-42 are wound around the winding core 22 of the core 20 in a predetermined order. The diameter of each of the wires 41 and 42 is not particularly limited, but is preferably 10 to 300 μm.

[0051] In this embodiment, the first wire 41 and the second wire 42 are wound around the winding core 22, for example, by bifilar winding. During the winding operation, any two of the lead portions 41a, 42a, 41b, 42b of the draw-out portions, which are the wire ends of the wires 41, 42, are crimped to the back surface (the lower surface along the Z axis) of the bottom surface mounting piece 51c1 or 52c1 of the predetermined terminal device 51 or 52 shown in FIG. 6 by the temporary fixing piece 51a2 or 52a2.

[0052] After the winding operation, the remaining two of the lead portions 41a, 42a, 41b, and 42b of the wires 41 and 42 are crimped using temporary fastening pieces 51a2 and 52a2. Thereafter, the lead portions 41a, 42a, 41b, and 42b of the wires 41 and 42 are crimped using connecting pieces 51a1 and 52a1, and then connected to the respective terminal devices 51 and 52 by laser irradiation or the like. Note that two of the lead portions may be connected before winding, and the remaining two lead portions may be connected after winding.

[0053] After winding the wires 41 and 42 around the winding core 22, the flat plate members 30 are joined, as necessary, to the opposite mounting sides 24b and 26b of the flanges 24 and 26. The joining means is not particularly limited, but may be, for example, an adhesive method.

[0054] 4, for example, resin is insert-molded so that the terminal devices 51, 52 except for at least a portion of the mounting pieces 51b, 52b, the magnetic core 20 (and the flat plate member 30 if present), and the wires 41, 42 are all covered with the insulating molded body 60. During the insert molding, it is preferable to inject the resin from approximately the center of the bottom wall surface 61 of the insulating molded body 60. At the resin injection port, a portion is formed on the surface of the molded body 60 that is recessed from the surface of the surrounding molded body 60.

[0055] The insulating molded body 60 is preferably made of an insulating material, and is preferably mainly made of a resin (either a thermoplastic resin or a thermosetting resin) such as polybutylene naphthalate, liquid crystal polymer, diallyl phthalate, polybenzimidazole, or polyphenylene sulfide, but may be made of other resins or materials other than resin. The insulating molded body 60 may also contain magnetic powder, and may further contain glass components or other fillers.

[0056] In this embodiment, of the mounting pieces 51b, 52b, the second mounting pieces 51b2, 52b2 are completely exposed from the insulating molding 60, and as for the first mounting pieces 51b1, 52b1, the surfaces facing the land pattern electrodes 80 are exposed and the surfaces opposite to that surface are embedded inside the insulating molding 60. However, in another embodiment, the first mounting pieces 51b1, 52b1 may also be completely exposed from the insulating molding 60, similar to the second mounting pieces 51b2, 52b2.

[0057] In the coil device 10 according to this embodiment, it is preferable that the wire length of the first wire 41 extending from the temporary fixing piece 51a2 of the first terminal fixture 51 to the temporary fixing piece 52a2 of the second terminal fixture 52 is approximately the same as the wire length of the second wire 42 extending from the temporary fixing piece 52a2 of the second terminal fixture 52 to the temporary fixing piece 51a2 of the first terminal fixture 51, but they may be different. Also, it is preferable that the number of turns of the first wire 41 and the number of turns of the second wire 42 in the winding portion 40 are the same. This configuration further improves the mode conversion characteristics.

[0058] In the coil device 10 of this embodiment, the terminal devices 51, 52 except for at least a portion of the mounting pieces 51b, 52b, the magnetic core 20, the plate-like member 30, and the wires 41, 42 are covered with the insulating molded body 60. Therefore, even if a coating process is performed on the substrate after the coil device 10 is mounted on the substrate, the insulating molded body 60 functions as a shield, and the coating resin is prevented from reaching the wire winding portion 40 of the coil device 10, the core, or the connection portions of the connection pieces 51a, 52a of the terminals 51, 52.

[0059] This reduces damage to the coil device 10 (such as wire breakage) caused by the coating on the substrate, improving the durability of the coil device 10. Furthermore, because the insulating molding 60 covers the core 20 and the flat plate member 30, it is possible to effectively prevent damage such as cracking and chipping of the core 20 and the flat plate member 30, preventing a decrease in magnetic permeability and a decrease in noise reduction effect.

[0060] Furthermore, in this coil device 10, the mounting pieces 51c, 52c of the terminal devices 51, 52 are attached to the outer surfaces 24a, 24e, 26a, 26e other than the outer end surface 24c of the flange portions 24, 26 located at the ends along the X-axis (the axis of the winding core portion 22). Therefore, the influence of the magnetic field lines emanating from the outer end surfaces 24c, 26c of the flange portions 24, 26 in a substantially perpendicular direction (the direction along the X-axis) is less likely to reach at least the mounting pieces 51c, 52c of the terminal devices 51, 52, making it possible to suppress the generation of eddy currents in those portions and to suppress adverse effects of eddy currents on impedance characteristics and the like (for example, signal loss).

[0061] Furthermore, in this coil device 10, the outer end surfaces 24c, 26c of the flanges 24, 26 are covered with the insulating molded body 60, which preferably has a minimum thickness of 0.3 mm or more, eliminating the need to hold the outer end surfaces 24c, 26c of the flanges 24, 26 with terminal fittings 51, 52 or the like. The outer end surfaces 24c, 26c of the flanges 24, 26, as well as the outer surface portions of the core 20 and the plate-like member 30 other than the outer end surfaces 24c, 26c, and the embedded portions of the terminal fittings 51 and 52 (excluding the vicinity of the exposed portions) are covered with the insulating molded body 60, preferably with a minimum thickness of 0.3 mm or more, more preferably 0.31 to 0.45 mm. Forming the insulating molded body 60 to such a thickness effectively protects the interior of the coil device 10 from the coating material on the substrate and also contributes to a more compact size.

[0062] In this embodiment, the mounting pieces 51c, 52c have bottom mounting pieces 51c1, 52c1 connected to the mounting sides 24a, 26a of the core 20, and side mounting pieces 51c2, 52c2 connected to the middle side surface 24e of the core 20. The mounting pieces 51c, 52c have the side mounting pieces 51c2, 52c2 in addition to the bottom mounting pieces 51c1, 52c1, which makes it easier to position the core 20 with the terminal fixtures 51, 52 before molding the insulating molded body 60, and also makes the terminal fixtures 51, 52 more firmly hold the core 20.

[0063] Furthermore, in this embodiment, the outer periphery of the wires 41, 42 wound around the winding core 22 may be covered with a protective layer made of, for example, silicone resin. By forming the protective layer, the winding portion 40 and the connection portion of the wires 41, 42 can be effectively protected against the resin pressure when the insulating molded body 60 is molded, and breakage of the wires 41, 42 can be effectively prevented.

[0064] In this embodiment, as shown in FIG. 4, at least a portion of the mounting pieces 51b and 52b of the terminal devices 51 and 52 is exposed from the insulating molding 60 near the boundary between the intermediate connecting pieces 51d and 52d and the mounting pieces 51b and 52b. That is, in this embodiment, of the mounting pieces 51b and 52b, the second mounting pieces 51b2 and 52b2 are completely exposed from the insulating molding 60, and the bottom surfaces (lower surfaces along the Z axis) of the first mounting pieces 51b1 and 52b2 and their vicinity are exposed. The inner surfaces of the first mounting pieces 51b1 and 52b2 opposite the bottom surfaces are embedded in the insulating molding 60, and only the minimum necessary portions of the first mounting pieces 51b1 and 52b2 are exposed. However, in this embodiment, the surfaces opposite the bottom surfaces of the first mounting pieces 51b1 and 52b2 may also be exposed from the insulating molding 60.

[0065] By having the mounting pieces 51b and 52b mainly exposed from the insulating molding 60 and the other parts covered by the insulating molding 60, the mounting of the coil device 10 is facilitated while the protection of the coil device 10 by the insulating molding 60 functions more effectively.

[0066] Furthermore, in this embodiment, the first mounting pieces 51b1, 52b1 can be arranged approximately parallel to the plane of the mounting pattern electrode 80, and the second mounting pieces 51b2, 52b2 formed continuously with the first mounting pieces 51b1, 52b1 are bent at a predetermined angle relative to the first mounting pieces 51b1, 52b1 in a direction away from the electrode 80.

[0067] With this configuration, the first mounting pieces 51b1, 52b1 become the portions that are directly connected to the land pattern electrode 80, and the second mounting pieces 51b2, 52b2 become the portions where the fillets of the solder 70 are formed, thereby strengthening the connection between the mounting pieces 51b, 52b and the land pattern electrode 80. In addition, the fillets of the solder 70 become easier to observe, making it easier to check the quality of the joint made by the solder 70. Note that instead of the solder 70, the terminal devices 51, 52 and the land pattern electrode 80 may be connected using a conductive bonding material such as a conductive adhesive.

[0068] In this embodiment, the intermediate connecting pieces 51d, 52d include an extended connecting piece 51d1 that is continuous and approximately flush with the bottom mounting pieces 51c1, 52c1, and leg-type connecting pieces 51d1, 52d1 that are bent toward the mounting piece 51b at a predetermined angle (for example, approximately perpendicular) relative to the extended connecting piece 51d1. Ends of the leg-type connecting pieces 51d1, 52d1 are continuous with the first mounting pieces 51b1, 52b1.

[0069] At the boundaries between the leg-shaped connecting pieces 51d1, 52d1 and the first mounting pieces 51b1, 52b1, the bottom surfaces of the first mounting pieces 51b1, 52b1 are exposed from the bottom wall surface 61 of the insulating molding 60. The first mounting pieces 51b1, 52b1 extend outward along the bottom wall surface 61 of the molding 60 and are bent near the boundaries between the bottom wall surface 61 and the side wall surface 62 so as to rise from the first mounting pieces 51b1, 52b1 along the side wall surface 62.

[0070] Furthermore, in this embodiment, second mounting pieces 51b2, 52b2 are provided on the tip sides of the first mounting pieces 51b1, 52b1, and the second mounting pieces 51b2, 52b2 stand up along the side wall surface 62 of the insulating molding 60. The second mounting pieces 51b2, 52b2 are spaced a predetermined distance from the side wall surface 62 of the insulating molding 60, and a gap 65 is formed between the second mounting pieces 51b2, 52b2 and the side wall surface 62.

[0071] This configuration ensures a sufficient mounting area for the fillets of the solder 70 formed on the terminal devices 51 and 52 during mounting, and also ensures sufficient mounting strength. Furthermore, the fillets of the solder 70 and the positions of the second mounting pieces 51b2 and 52b2 of the terminal devices 51 and 52 can be easily viewed (recognized) with an imaging device such as a camera, making it easier to determine whether the coil device 10 is securely mounted, and improving the reliability of the mounting strength.

[0072] Furthermore, since the second mounting pieces 51b2, 52b2, which are the rising portions of the terminal fittings 51, 52, are spaced apart from the side wall surface 62 of the insulating molding 60 (there is a gap / or an air layer between them), heat transfer from the rising portions of the terminal fittings 51, 52 to the side wall surface 62 of the insulating molding 60 is suppressed during mounting, and thermal deterioration of the insulating molding (resin molding) 60 is suppressed.

[0073] It is preferable that gap 65 becomes wider as it gets farther from first mounting pieces 51b1, 52b1, but it may be constant. By forming gap 65, it is preferable that heat generated when forming fillets of solder 70 is less likely to be transmitted to insulating molding body 60. In this embodiment, gap (predetermined distance) 65 is, for example, 0.03 mm or more, and preferably 0.031 to 0.110 mm.

[0074] 8, the bending angle θ of the second mounting pieces 52b2, 52b2 relative to the first mounting pieces 51b2, 52b1 is preferably within a range of 87 degrees to 93 degrees, and more preferably within a range of 88.5 degrees to 91.5 degrees. That is, the angle θ is substantially 90 degrees. Furthermore, the side wall surface 62 of the insulating molding 60 is tapered relative to the first mounting pieces 51b1, 52b1 so that the distance between the second mounting pieces 51b2, 52b2 and the side wall surface 62 increases with increasing distance from the first mounting pieces 51b1, 52b1.

[0075] This configuration makes it easier to create a configuration in which the second mounting pieces 51b2, 52b2 are spaced a predetermined distance from the side wall surface 62 of the insulating molded body 60. Furthermore, this configuration makes it possible, after molding the insulating molded body 60, to bend the second mounting pieces 51b2, 52b2 relative to the first mounting pieces 51b1, 52b1 to a position where the second mounting pieces 51b2, 52b2 contact the side wall surface 62 of the insulating molded body 60. Thereafter, the second mounting pieces 51b2, 52b2 recover from the bending deformation slightly due to springback, and deform in a self-aligning manner to a preferred predetermined angle (θ is approximately 90 degrees) relative to the first mounting pieces 51b1, 52b1, and the distance from the side wall surface 62 is also self-aligningly adjusted to the predetermined distance.

[0076] 9A, in this embodiment, the second mounting pieces 51b2, 52b2 are raised at a preferable predetermined angle θ (substantially 90 degrees), which maximizes the height H of the fillets of the solder 70, improving the mounting strength and facilitating observation of the fillets of the solder 70. Note that, as shown in FIG. 9B, when the angle θ is outside the preferable range, the height of the fillets of the solder 70 becomes lower than the maximum height difference.

[0077] 5, in this embodiment, all components of the terminal devices 51, 52 are arranged so as not to overlap the end faces 24c, 26c of the flange portions 24, 26 when viewed along the X-axis. This configuration effectively suppresses adverse effects on impedance characteristics, etc., due to eddy currents caused by leakage magnetic flux from the end faces 24c, 26c.

[0078] The coil device 10 of this embodiment can be preferably used for power supply applications, and even when used for signal system applications, it is possible to suppress an increase in insertion loss (IR / insertion loss), and it can be preferably used for high-frequency signal system applications, for example, at 100 kHz or higher.

[0079] Second embodiment 1B, 3B, and 5B, the coil device 210 of this embodiment is similar to the coil device 110 of the first embodiment, except that the terminal devices 251, 252 and the insulating molded body 60 are different from the terminal devices 51, 52 and the insulating molded body 60 of the first embodiment described above. Below, the parts that are different from the first embodiment will be mainly described in detail, and a description of the parts that are in common will be omitted.

[0080] 3B, the terminal fittings 251, 252 of this embodiment are substantially identical in basic components to the terminal fittings 51, 52 of the first embodiment, and corresponding components are assigned common reference numerals, with some descriptions thereof being omitted. Specifically, the components corresponding to the reference numerals of the components of the terminal fittings 51, 52 of the first embodiment plus the numeral 200 are the components in this embodiment that correspond to the components of the terminal fittings 51, 52 of the first embodiment, and some descriptions of the corresponding components will be omitted to avoid duplication.

[0081] 5A and 5B, in this embodiment, unlike the first embodiment described above, the mounting pieces 251b and 252b are arranged closer to the inside of the coil device 210 along the Y axis. In this embodiment, the outer ends of the mounting pieces 251b and 252b along the Y axis are preferably located near or inside an imaginary plane including the middle side surfaces 24e and 26e of the flanges 24 and 26. Alternatively, the outer ends of the mounting pieces 251b and 252b along the Y axis are preferably located inside the outer surfaces of the side mounting pieces 251c2 and 252c2 along the Y axis.

[0082] In this embodiment, as shown in FIG. 3B, the lengths of the inward convex pieces 251c3 and 252c3 along the Y axis are shorter than those of the inward convex pieces 51c3 and 52c3 shown in FIG. 3A.

[0083] 5B and 5A, the width of the coil device 210 of this embodiment along the Y axis can be made smaller than the width of the coil device 10 along the Y axis. Alternatively, the thickness of the insulating molded body 60 covering the ends of the terminal devices 251 and 252 along the Y axis can be made thicker than that of the coil device 10.

[0084] Other configurations and effects of the coil device 210 of this embodiment are similar to those of the coil device 10 described above.

[0085] Third embodiment Although not shown, in the coil device of this embodiment, the resin molded body is configured as a resin case, and the resin case is in contact with parts of the terminal fittings 51, 52, but the inside of the case is hollow, and the inner surface of the case does not contact parts other than the terminal fittings 51, 52 that are in contact with the case and exposed to the outside, the core 20, and the wires 41, 42. The inner surface of the case may be in partial contact with the flat plate member 30, but need not be in contact.

[0086] The case may have a case body having a storage recess and a lid attached to the opening of the storage recess of the case body to form an internal space. For example, terminal devices 51, 52 may be attached to the lid so that at least a portion of the mounting pieces of the terminal devices 51, 52 are positioned outside.

[0087] The case may be filled with air or a predetermined gas, or may be filled with a fluid resin such as silicone resin. The fluid resin may be hardened or semi-hardened after being embedded.

[0088] The resin embedded in these cases may be composed of a component with excellent heat dissipation properties, or may contain other fillers, etc. Parts of the terminal devices 51, 52, the core 20, the wires 41, 42, and at least parts of the flat plate member disposed inside the cases may be immersed in the resin embedded in the cases.

[0089] In this embodiment, the other configurations and effects are the same as those of the first to third embodiments described above.

[0090] In the above-described embodiments, "covered by the insulating molding" means that the insulating molding 60 may be in direct contact with the insulating molding 60 and covered therewith, as shown in the first to third embodiments, or may be in direct contact with the insulating molding 60 and covered therewith, as shown in this embodiment.

[0091] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, embodiments that combine at least a part of two or more of the first to third embodiments described above are also possible. [Explanation of symbols]

[0092] 10,110,210... Coil device 20... Core 22... Winding core 24... First flange 24a... Mounting side 24b... Anti-mounting side 24c... Outer end surface 24c1... Terminal mounting surface 24c2... Terminal insulating protrusion 24c3... Notch 24d…Inside 24e… Middle side 26... Second flange 26a... Mounting side 26b... Anti-mounting side 26c… Outer end surface 26c1... Terminal mounting surface 26c3... Notch 26d… Inner 26e… Medial side 30... Flat plate member 40... Winding section 41... First wire 41a, 41b... Lead section 42... Second wire 42a, 42b... Lead section 51,251… 1st terminal fitting 51a1,251a1... Wire connection piece (connection part) 51a2,251a2...Temporary fastening piece 51b, 251b... Mounting piece 51b1, 251b1... First mounting piece 51b2, 251b2... Second mounting piece 51c,251c… Mounting piece 51c1,251c1…Bottom mounting piece 51c2,251c2…Side mounting piece 51c3,251c3… Inward convex piece 51d,251d… Intermediate connection piece 51d1,251d1… Extension connection piece 51d2,251d2… Leg type connecting piece 52,252… 2nd terminal fitting 52a, 252a… Wire connection piece (connection part) 52b, 252b... Mounting piece 52b1, 252b1... First mounting piece 52b2, 252b2... Second mounting piece 52c,252c… Mounting piece 52c1,252c1…Bottom mounting piece 52c2,252c2…Side mounting piece 52c3,252c3… Inward convex piece 52d,252d… Intermediate connection piece 52d1,252d1… Extension connection piece 52d2,252d2… Leg type connecting piece 60... Insulating molding 61... Bottom wall 62... Side wall 65... Gap 70... Solder 80... Land pattern electrode (mounting pattern electrode)

Claims

1. a magnetic core having a winding core portion and a flange portion formed at an end of the winding core portion along an axial center; a wire wound around the winding core; A coil device having a terminal device to which a lead portion of the wire is connected, The terminal tool is an attachment piece attached to the flange; a mounting piece to be connected to the mounting pattern electrode; an intermediate connecting piece that continuously connects the mounting piece and the mounting piece, The terminal device, the magnetic core, and the wire are covered with an insulating molding, except for at least a part of the mounting piece. A coil device in which a portion of the mounting piece is erected along a side wall surface of the insulating molding and is spaced a predetermined distance from the side wall surface.

2. The mounting piece is a first mounting piece that can be arranged substantially parallel to the plane of the mounting pattern electrode; a second mounting piece formed continuously with the first mounting piece and bent at a predetermined angle relative to the first mounting piece, a bending angle of the second mounting piece relative to the first mounting piece is within a range of 87 degrees to 93 degrees; 2. The coil device according to claim 1, wherein the second mounting piece is erected along a side wall surface of the insulating molding and is spaced a predetermined distance from the side wall surface.

3. 3. The coil device according to claim 2, wherein the side wall surface of the insulating molding is inclined relative to the first mounting piece so that the distance between the second mounting piece and the side wall surface increases as the distance from the first mounting piece increases.

4. The attachment piece is The coil device according to any one of claims 1 to 3, wherein the coil device is attached to an outer surface other than the outer end surface of the flange portion located at an end along the axis.

5. The attachment piece is a bottom surface mounting piece connected to a mounting side surface of the outer surface of the flange portion; The coil device according to claim 4 , further comprising: a side mounting piece connected to an anti-mounting side surface of the flange portion located opposite the mounting side surface; and an intermediate side surface located between the mounting side surface and the flange portion.

6. 4. The coil device according to claim 1, wherein at least the outer periphery of the wire wound around the core portion is covered with a protective layer.

7. 4. The coil device according to claim 1, wherein at least a portion of the mounting piece of the terminal fixture is exposed from the insulating molding near the boundary between the intermediate connecting piece and the mounting piece.

8. 4. The coil device according to claim 2, wherein the second mounting piece is provided on the tip side of the first mounting piece.

9. the mounting piece has a bottom mounting piece connected to a mounting side surface of the outer surface of the flange portion, The intermediate connecting piece has an extended connecting piece that is continuous with the bottom mounting piece and is substantially flush with the bottom mounting piece, and a leg-shaped connecting piece that is bent toward the mounting piece at a predetermined angle relative to the extended connecting piece, The coil device according to claim 8 , wherein an end of the leg-shaped connecting piece is continuous with the first mounting piece.

10. 4. The coil device according to claim 1, wherein the terminal fixture is arranged so as not to overlap an end face of the flange portion when viewed along the axis.

Images