Coil device

Abstract

To provide a coil device that can prevent damage of a core.SOLUTION: A coil device 1 includes an annular core including a winding core part and a flange part 22a formed at an end part in an axis direction of the winding core part, a wire 10 wound around the winding core part, and a terminal 31 attached to the flange part 22a and connected to an extraction part 12a of the wire 10. The flange part 22a includes an outer end surface 224 perpendicular to the axis direction and a bottom surface 221 facing an implementation board. The terminal 31 includes a fixing part that is disposed along the outer end surface 224, and an implementation part 36 disposed along the bottom surface 221. The fixing part includes an adhesive part 350 attached to the outer end surface 224, and a narrow part 352 having a narrower width than the adhesive part 350. At least a part of the narrow part 352 is not attached the outer end surface 224.SELECTED DRAWING: Figure 6A

Description

[Technical Field]

[0001] The present disclosure relates to a coil device. [Background technology]

[0002] Patent Document 1 discloses a coil device that functions as a common mode filter. The coil device of Patent Document 1 has an annular core, a wire wound around the core, and a terminal attached to the core. The core has a winding core portion and a flange portion formed at the axial end of the winding core portion. The flange portion has an outer end surface perpendicular to the axial direction of the winding core portion, a bottom surface facing the mounting board, and a top surface opposite the bottom surface. The wire is wound around the winding core portion, and a lead-out portion of the wire is connected to the terminal. The terminal has a fixing portion arranged along the outer end surface, a mounting portion arranged along the bottom surface, and a connecting portion arranged along the top surface and connected to the lead-out portion of the wire. The fixing portion is bonded to the outer end surface with an adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-192169 Summary of the Invention [Problem to be solved by the invention]

[0004] The coil device of Patent Document 1 has the following concerns: When the mounting section is connected to the mounting board, if the mounting board is deformed (for example, the mounting board is twisted), excessive stress is applied to the core, which may cause damage to the core.

[0005] The present disclosure provides a coil device capable of preventing damage to the core. [Means for solving the problem]

[0006] The coil device of the present disclosure is an annular core having a winding core portion and a flange portion formed at an axial end portion of the winding core portion; a wire wound around the winding core; a terminal attached to the flange and connected to the lead-out portion of the wire, the flange portion has an outer end surface perpendicular to the axial direction and a bottom surface facing a mounting substrate, the terminal has a fixing portion disposed along the outer end surface and a mounting portion disposed along the bottom surface, the fixing portion has an adhesive portion that is adhered to the outer end surface and a narrow portion that has a width narrower than that of the adhesive portion, At least a portion of the narrowed portion is not bonded to the outer end surface.

[0007] In the coil device of the present disclosure, when the mounting board is deformed (for example, the mounting board is twisted) while the mounting section is connected to the mounting board, the following effect is obtained. That is, because at least a portion of the narrow section is not bonded to the outer end surface, the narrow section is more likely to deform as the mounting board deforms. In particular, because the narrow section has a width narrower than the bonded section, it can deform more easily than the bonded section. Therefore, stress generated by deformation of the mounting board (hereinafter simply referred to as "stress") is absorbed by the terminal due to the deformation of the narrow section, and is less likely to be transmitted to the core. This makes it less likely that excessive stress will be applied to the core, preventing damage to the core.

[0008] In addition, since the adhesive portion has a width greater than the narrow portion, the adhesive area of ​​the adhesive portion is secured, and the adhesive strength between the adhesive portion and the outer end surface can be increased. In this way, the coil device of the present disclosure can increase the adhesive strength of the terminal to the core while preventing damage to the core.

[0009] The narrow portion may be closer to the mounting portion than the adhesive portion and may be continuous with the mounting portion.

[0010] The flange portion may have a side surface perpendicular to the outer end surface and the bottom surface, the fixing portion may have a first edge portion and a second edge portion farther from the side surface than the first edge portion, and the terminal may have a first notch portion formed in the first edge portion along the narrow portion.

[0011] In addition to the first cutout, the terminal may have a second cutout formed in the second edge along the narrow portion.

[0012] The narrow portion may protrude in a direction away from the outer end surface.

[0013] The mounting portion may be spaced apart from the bottom surface.

[0014] A first gap is formed between the narrow portion and the outer end surface, and a second gap is formed between the mounting portion and the bottom surface, and the maximum distance between the narrow portion and the outer end surface may be longer than the minimum distance between the mounting portion and the bottom surface.

[0015] The narrow portion may be located on the same plane as the adhesive portion.

[0016] The mounting portion may have the same width as the narrow portion.

[0017] The core may further include a cover attached to the core and covering the top surface opposite the bottom surface and the winding core portion, and the cover may have a flat plate portion parallel to the top surface. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a coil device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of the coil device of FIG. 1 with the cover omitted. [Figure 3] FIG. 3 is a perspective view of the core of FIG. [Figure 4] FIG. 4 is a perspective view of the cover of FIG. [Figure 5] FIG. 5 is a perspective view of the terminal of FIG. [Figure 6A] FIG. 6A is a side view of the coil device of FIG. 2 as seen along the X axis. [Figure 6B] FIG. 6B is a side view of the coil device of FIG. 2 as viewed along the Y axis. [Figure 7A] FIG. 7A is a perspective view of a terminal of a coil device according to a second embodiment. [Figure 7B] FIG. 7B is a perspective view of a terminal of the coil device according to the third embodiment. [Figure 8] FIG. 8 is a perspective view of a coil device according to the fourth embodiment. [Figure 9] FIG. 9 is a perspective view of the terminal of FIG. [Figure 10] FIG. 10 is a side view of the coil device of FIG. 8 as seen along the Y axis. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the contents shown in the drawings are merely schematic and illustrative for understanding the present disclosure, and the appearance and dimensional ratios may differ from the actual product. Furthermore, the present disclosure is not limited to the following embodiments.

[0020] First embodiment A coil device 1 of the first embodiment shown in Fig. 1 functions as, for example, a common mode filter or a common mode choke coil, and is mounted on a power supply circuit or the like. As shown in Figs. 1 and 2, the coil device 1 has a wire 10, a wire 13, a core 20, and terminals 31 to 34. In addition to these components, the coil device 1 further has a cover 60, although the cover 60 is not essential.

[0021] As shown in Fig. 2, wire 10 has a spirally wound portion 11 and lead portions 12a and 12b drawn out from winding portion 11. Wire 13 has a spirally wound portion 14 and lead portions 15a and 15b drawn out from winding portion 14. The material constituting wire 10 or 13 is not particularly limited, but may be, for example, copper, a copper alloy, silver, or nickel. The diameter of wire 10 or 13 is not particularly limited, but may be, for example, 10 to 200 µm.

[0022] The wire 10 or 13 is, for example, an insulating-coated wire, and has a conductive core wire coated with an insulating coating. The wire 10 or 13 is a known wound wire such as AIW (polyamideimide copper wire), UEW (polyurethane copper wire), or PEW (polyester copper wire). The wire 10 or 13 is a round wire, but may also be a square wire, twisted wire, Litz wire, braided wire, or the like. The coating is stripped from at least a portion of the lead-out portion 12a or 12b, exposing the conductive core wire. The coating is stripped from at least a portion of the lead-out portion 15a or 15b, exposing the conductive core wire.

[0023] As shown in FIG. 3, the core 20 is an annular core and includes a winding core portion 21a, a winding core portion 21b, a flange portion 22a, and a flange portion 22b. The core 20 is formed of a material containing a magnetic material and a resin. The magnetic material constituting the core 20 is not particularly limited, but may be, for example, ferrite (Ni-Zn ferrite, Mn-Zn ferrite, etc.) or a metallic magnetic material (Fe-Ni alloy, Fe-Si alloy, Fe-Si-Cr alloy, Fe-Co alloy, Fe-Si-Al alloy, amorphous iron, etc.). The resin constituting the core 20 is not particularly limited, but may be, for example, epoxy resin, phenol resin, polyester resin, polyurethane resin, polyimide resin, etc. The core 20 may be a sintered body of a metallic magnetic material.

[0024] The cross-sectional shape of winding cores 21a and 21b is rectangular, but may be other polygonal shapes (e.g., hexagonal or octagonal), circular, elliptical, etc. As shown in Fig. 2, wire 10 is wound around winding core 21a, and wire 13 is wound around winding core 21b.

[0025] As shown in Fig. 3, flange portion 22a is formed at one axial end of winding core portions 21a and 21b. Flange portion 22b is formed at the other axial end of winding core portions 21a and 21b. Flange portion 22a has a bottom surface 221, a top surface 222, an inner end surface 223, an outer end surface 224, a first side surface 225, and a second side surface 226. Similarly, flange portion 22b has a bottom surface 221, a top surface 222, an inner end surface 223, an outer end surface 224, a first side surface 225, and a second side surface 226. However, the shapes of flange portions 22a and 22b are not limited to the shapes shown in Fig. 3.

[0026] The bottom surface 221 is a surface facing a mounting board (not shown). The top surface 222 is a surface opposite the bottom surface 221 and faces the bottom surface 221. The outer end surface 224 is a surface perpendicular to the axial direction of the winding core portions 21a and 21b. The inner end surface 223 is a surface connected to the axial ends of the winding core portions 21a and 21b and faces the outer end surface 224. The first side surface 225 is a surface perpendicular to the outer end surface 224 and the bottom surface 221. The second side surface 226 is a surface perpendicular to the outer end surface 224 and the bottom surface 221 and faces the first side surface 225.

[0027] In the following description, the axis along which inner end surface 223 and outer end surface 224 face each other is referred to as the X-axis. The X-axis is an axis parallel to the axial direction of winding core portions 21a and 21b. The axis along which first side surface 225 and second side surface 226 face each other is referred to as the Y-axis. The axis along which bottom surface 221 and top surface 222 face each other is referred to as the Z-axis. The X-axis, Y-axis, and Z-axis are mutually orthogonal.

[0028] In this disclosure, the positive side of the Z axis is referred to as the "upper side," and the negative side of the Z axis is referred to as the "lower side." However, the upper side in the Z axis direction does not necessarily coincide with the upper side in the vertical direction. Also, the lower side in the Z axis direction does not necessarily coincide with the lower side in the vertical direction.

[0029] Furthermore, in the present disclosure, "equal" or "similar" does not only refer to a state in which the physical quantities of the multiple objects being compared are strictly equal or similar, but also includes a state in which there is an error of ±Δ% or less (not particularly limited, for example, Δ=7, 5, or 3) between the physical quantities of the multiple objects being compared.

[0030] Furthermore, in the present disclosure, "parallel" does not only refer to strict parallelism, but also includes a state in which there is an error of ±Δθ° (not particularly limited, for example, Δθ=3) or less from strict parallelism. Furthermore, "perpendicular" or "orthogonal" does not only refer to strict perpendicular or orthogonal, but also includes a state in which there is an error of ±Δθ° (not particularly limited, for example, Δθ=3) or less from strict perpendicular or orthogonal.

[0031] An outer end surface 224 of flange 22a is formed with protrusion 23a, recess 24a, and recess 25a. An outer end surface 224 of flange 22b is formed with protrusion 23b, recess 24b, and recess 25b. Protrusion 23a is located between recess 24a and recess 25a along the Y axis. Protrusion 23b is located between recess 24b and recess 25b along the Y axis. As shown in FIG. 2, a portion of terminal 31 is disposed in recess 24a, and a portion of terminal 32 is disposed in recess 25a. A portion of terminal 33 is disposed in recess 24b, and a portion of terminal 34 is disposed in recess 25b.

[0032] As shown in Fig. 3, a fitting recess 26a is formed in the inner end surface 223 of the flange portion 22a. Furthermore, a fitting recess 26b is formed in the inner end surface 223 of the flange portion 22b. The fitting recesses 26a and 26b are located in the center of the inner end surface 223 in the Y-axis direction and extend from the upper end to the lower end of the inner end surface 223. Parts of the cover 60 (Fig. 1) fit into the fitting recesses 26a and 26b.

[0033] 3, although it is not essential, the intersection between the bottom surface 221 and the first side surface 225 is chamfered. Also, although it is not essential, the intersection between the bottom surface 221 and the second side surface 226 is chamfered. The axial end of winding core portion 21a is connected to inner end surface 223 at a position offset upward from the center of inner end surface 223 in the Z axis direction. Also, the axial end of winding core portion 21b is connected to inner end surface 223 at a position offset upward from the center of inner end surface 223 in the Z axis direction.

[0034] As shown in Fig. 4, the cover 60 has a flat portion 61, side portions 62-63, leg portions 64a-64d, claw portions 65a-65d, protrusions 66a-66b, and a fitting protrusion 67. The cover 60 is made of a non-magnetic material such as resin. However, the cover 60 may contain a magnetic material such as a metallic magnetic material or ferrite. In this case, the cover 60 and the core 20 form a closed magnetic circuit.

[0035] As shown in Fig. 1, cover 60 is attached to core 20. Flat plate portion 61 has a flat plate shape and covers core 20 from above. Flat plate portion 61 covers, for example, top surfaces 222 of flange portions 22a and 22b, winding core portion 21a, and winding core portion 21b from above as shown in Fig. 3. Flat plate portion 61 extends parallel to top surface 222 and is positioned above and spaced apart from top surface 222.

[0036] As shown in Fig. 4, the side portion 62 extends downward from one end of the flat plate portion 61 in the Y-axis direction so as to be perpendicular to the flat plate portion 61. The side portion 63 extends downward from the other end of the flat plate portion 61 in the Y-axis direction so as to be perpendicular to the flat plate portion 61. The side portion 62 has a leg portion 64a and a leg portion 64b spaced apart from the leg portion 64a. The side portion 63 has a leg portion 64c and a leg portion 64d spaced apart from the leg portion 64c. The legs 64a to 64d extend downward.

[0037] Claw portion 65a is formed at the tip of leg portion 64a, claw portion 65b is formed at the tip of leg portion 64b, claw portion 65c is formed at the tip of leg portion 64c, and claw portion 65d is formed at the tip of leg portion 64d. Claw portions 65a to 65d protrude from the tips of legs 64a to 64d toward the inside of cover 60 along the Y axis. As shown in FIG. 1, claw portion 65a and claw portion 65c engage with bottom surface 221 of flange portion 22a. Claw portion 65b and claw portion 65d (not shown) engage with bottom surface 221 of flange portion 22b.

[0038] As shown in Fig. 4, the protrusion 66a protrudes downward from one end of the flat plate portion 61 in the X-axis direction so as to be perpendicular to the flat plate portion 61. The protrusion 66b protrudes downward from the other end of the flat plate portion 61 in the X-axis direction so as to be perpendicular to the flat plate portion 61. As shown in Fig. 1, the tip of the protrusion 66a abuts against the top surface 222 of the flange portion 22a. Although detailed illustration is omitted, the tip of the protrusion 66b abuts against the top surface 222 of the flange portion 22b.

[0039] As shown in FIG. 4, the fitting protrusion 67 protrudes downward from the center of the flat plate portion 61 so as to be perpendicular to the flat plate portion 61. The fitting protrusion 67 has a flat shape that is thin in the Y-axis direction. The fitting protrusion 67 is disposed between the winding core portions 21a and 21b shown in FIG. 3. One end of the fitting protrusion 67 in the X-axis direction fits into the fitting recess 26a. The other end of the fitting protrusion 67 in the X-axis direction fits into the fitting recess 26b. The fitting protrusion 67 is disposed between the winding portion 11 (FIG. 2) and the winding portion 14 (FIG. 2), and can ensure insulation therebetween.

[0040] As shown in Fig. 2, terminals 31 and 32 are attached to flange portion 22a, and terminals 33 and 34 are attached to flange portion 22b. Terminal 31 is connected to lead-out portion 12a of wire 10. Terminal 32 is connected to lead-out portion 15a of wire 13. Terminal 33 is connected to lead-out portion 12b of wire 10. Terminal 34 is connected to lead-out portion 15b of wire 13.

[0041] 5, terminals 31 and 34 have the same shape. Terminals 32 and 33 have the same shape. Terminals 31 and 32 have mirror-symmetric shapes. Terminals 33 and 34 have mirror-symmetric shapes.

[0042] The terminals 31 to 34 are made of a conductor such as metal. The material constituting the terminals 31 to 34 is not particularly limited, but may be, for example, copper, copper alloy, silver, or nickel. A plating film may be formed on the surface of the terminals 31 to 34. The plating film may be a single layer or multiple layers. The plating film is not particularly limited, but may be, for example, Cu plating, Ni plating, Sn plating, Ni-Sn plating, Cu-Ni-Sn plating, Ni-Au plating, or Au plating. The thickness of the terminals 31 to 34 is not particularly limited, but may be, for example, 50 to 600 μm.

[0043] Terminals 31 to 34 each have a fixed portion 35, a mounting portion 36, and a wire connection portion 37. Fixed portion 35 has an adhesive portion 350 and a narrow portion 352. Narrow portion 352 is closer to mounting portion 36 than adhesive portion 350 is, and is continuous with mounting portion 36. As shown in FIG. 6A , fixed portion 35 has an L-shape when viewed from the X-axis direction, and is disposed along outer end surface 224. Adhesive portion 350 is disposed parallel to outer end surface 224, and is adhered to outer end surface 224 with an adhesive.

[0044] More specifically, the adhesive portion 350 of terminal 31 is adhered to the bottom surface of recess 24a of flange 22a with an adhesive. The adhesive portion 350 of terminal 32 is adhered to the bottom surface of recess 25a of flange 22a with an adhesive. Although not shown in detail, the adhesive portion 350 of terminal 33 (FIG. 5) is adhered to the bottom surface of recess 24b (FIG. 3) of flange 22b with an adhesive. The adhesive portion 350 of terminal 34 (FIG. 5) is adhered to the bottom surface of recess 25b (FIG. 3) of flange 22b with an adhesive.

[0045] The shape of the adhesive portion 350 when viewed from the X-axis direction is a rectangle with its long side in the Y-axis direction and its short side in the Z-axis direction. However, the shape of the adhesive portion 350 when viewed from the X-axis direction may also be a rectangle with its long side in the Z-axis direction and its short side in the Y-axis direction. The shape of the adhesive portion 350 when viewed from the X-axis direction may also be a square or other polygon.

[0046] 6A shows an adhesive application area 72 as viewed from the X-axis direction. In the example shown in FIG. 6A, the adhesive application area 72 is formed over the entire adhesive portion 350. The adhesive application area 72 may be formed over 30% or more of the adhesive portion 350, or over 50% or more of the adhesive portion 350, or over 70% or more of the adhesive portion 350, or over 90% or more of the adhesive portion 350. Furthermore, a portion of the adhesive application area 72 may be formed outside the adhesive portion 350. As shown in FIG. 6B, the adhesive portion 350 is housed in the recess 24a or 24b and is adhered to the outer end surface 224 (the bottom surface of the recess 24a or 24b) by the adhesive 70.

[0047] 6A, the shape of narrow width portion 352 when viewed from the X-axis direction is a rectangle with its long side in the Z-axis direction and its short side in the Y-axis direction. However, the shape of narrow width portion 352 when viewed from the X-axis direction may also be a rectangle with its long side in the Y-axis direction and its short side in the Z-axis direction. Furthermore, the shape of narrow width portion 352 when viewed from the X-axis direction may be a square or other polygon.

[0048] When viewed in the X-axis direction, the narrow width portion 352 has a width (horizontal width: width in the Y-axis direction) narrower than the adhesive portion 350. Therefore, the narrow width portion 352 is configured to be weaker than the adhesive portion 350, and the rigidity of the narrow width portion 352 is lower than the rigidity of the adhesive portion 350.

[0049] At least a portion of the narrow width portion 352 (in this embodiment, the entire narrow width portion 352) is not bonded to the outer end surface 224 by adhesive. However, for example, adhesive attached to the adhesive portion 350 may inevitably reach the narrow width portion 352, causing a portion of the narrow width portion 352 to be bonded to the outer end surface 224 by adhesive. Even in such a case, it is desirable that, for example, 80% or 90% or more of the area of ​​the narrow width portion 352 is not bonded to the outer end surface 224 by adhesive.

[0050] The narrow width portion 352 is not bonded to the outer end surface 224 with an adhesive, and therefore can deform in response to the application of stress (external force). As described above, the narrow width portion 352 has a narrower width than the bonded portion 350 and has lower rigidity than the bonded portion 350. Therefore, the narrow width portion 352 can deform more easily in response to the application of stress (external force) than the bonded portion 350. This allows the narrow width portion 352 to absorb the stress applied to the fixed portion 35.

[0051] In this embodiment, the ratio W1 / W2 of the width W1 of the narrow width portion 352 to the width W2 of the adhesive portion 350 is less than 1 / 2. However, the ratio W1 / W2 of the width W1 of the narrow width portion 352 to the width W2 of the adhesive portion 350 may be W1 / W2<1, W1 / W2≦9 / 10, W1 / W2≦4 / 5, W1 / W2≦7 / 10, W1 / W2≦3 / 5, W1 / W2≦1 / 2, W1 / W2≦2 / 5, or W1 / W2≦3 / 10. In this case, the narrow width portion 352 becomes more likely to deform in response to application of stress and to absorb the stress more easily.

[0052] Furthermore, the ratio W1 / W2 of the width W1 of the narrow width portion 352 to the width W2 of the adhesive portion 350 may be 1 / 10≦W1 / W2≦4 / 5, 1 / 5≦W1 / W2≦7 / 10, 1 / 5≦W1 / W2≦3 / 5, or 3 / 10≦W1 / W2≦3 / 5. In this case, the strength of the narrow width portion 352 is ensured, and the stability of the fixing portion 35 is improved.

[0053] In the example shown in FIG. 6A, the length of the narrow portion 352 in the Z-axis direction is longer than the length of the bonding portion 350 in the Z-axis direction. However, the length of the narrow portion 352 in the Z-axis direction may be equal to or shorter than the length of the bonding portion 350 in the Z-axis direction.

[0054] In this embodiment, the ratio L1 / L2 of the length L1 of the narrow portion 352 in the Z-axis direction to the length L2 of the fixing portion 35 in the Z-axis direction is 1 / 2 < L1 / L2. The ratio L1 / L2 of the length L1 of the narrow portion 352 in the Z-axis direction to the length L2 of the fixing portion 35 in the Z-axis direction may also be 1 / 2 ≦ L1 / L2 or 3 / 5 ≦ L1 / L2. In this case, the narrow portion 352 is likely to deform in response to the application of stress and is likely to absorb stress.

[0055] The ratio L1 / L2 of the length L1 of the narrow portion 352 in the Z-axis direction to the length L2 of the fixing portion 35 in the Z-axis direction may also be L1 / L2 ≦ 1 / 2 or L1 / L2 ≦ 1 / 3. Alternatively, the ratio L3 / L2 of the length L3 of the bonding portion 350 in the Z-axis direction to the length L2 of the fixing portion 35 in the Z-axis direction may also be 2 / 3 ≦ L3 / L2. In this case, the area of the bonding portion 350 is ensured, and the bonding strength between the bonding portion 350 and the outer end surface 224 is improved.

[0056] In the example shown in FIG. 6A, the narrow portion 352 has a width (lateral width: width in the Y-axis direction) that is narrower than the mounting portion 36 when viewed from the X-axis direction. Therefore, the narrow portion 352 is configured to be more fragile than the mounting portion 36, and the rigidity of the narrow portion 352 is lower than the rigidity of the mounting portion 36.

[0057] The fixing portion 35 has a first edge portion 356 and a second edge portion 358. The first edge portion 356 is closer to the center of the flange portion 22a in the Y-axis direction than the second edge portion 358. The second edge portion 358 of the terminal 31 is farther from the first side surface 225 in the Y-axis direction than the first edge portion 356 of the terminal 31. The second edge portion 358 of the terminal 32 is farther from the second side surface 226 in the Y-axis direction than the first edge portion 356 of the terminal 32. Also, the second edge portion 358 of the terminal 31 is closer to the terminal 32 than the first edge portion 356 of the terminal 31. The second edge portion 358 of the terminal 32 is closer to the terminal 31 than the first edge portion 356 of the terminal 32.

[0058] The first edge 356 and the second edge 358 extend linearly along the Z axis, although the first edge 356 and the second edge 358 may extend obliquely with respect to the Z axis or may be curved.

[0059] A notch 38 is formed in the first edge 356 along the narrow portion 352. The notch 38 cuts out the first edge 356 so that the fixing portion 35 has an L-shape. By forming the notch 38 in the first edge 356, the narrow portion 352 is formed in the fixing portion 35.

[0060] 6B , the narrow width portion 352 is bent relative to the adhesive portion 350 and protrudes in a direction away from the outer end surface 24 (toward the positive or negative direction of the X-axis). The narrow width portion 352 has a bent portion 354. From the boundary between the adhesive portion 350 and the narrow width portion 352 to the bent portion 354, the narrow width portion 352 extends obliquely relative to the adhesive portion 350 so as to move away from the outer end surface 224. However, from the boundary between the adhesive portion 350 and the narrow width portion 352 to the bent portion 354, the narrow width portion 352 may also extend perpendicular to the adhesive portion 350 so as to move away from the outer end surface 224.

[0061] Furthermore, the narrow portion 352 extends parallel to the outer end surface 224 from the boundary between the mounting portion 36 and the narrow portion 352 to the bent portion 354. The narrow portion 352 extends linearly from the boundary between the mounting portion 36 and the narrow portion 352 to the bent portion 354. However, the narrow portion 352 may extend obliquely with respect to the outer end surface 224 from the boundary between the mounting portion 36 and the narrow portion 352 to the bent portion 354. The narrow portion 352 may also extend nonlinearly from the boundary between the mounting portion 36 and the narrow portion 352 to the bent portion 354.

[0062] A first gap 40 is formed between the narrow portion 352 and the outer end surface 224. The first gap 40 is, but is not limited to, an air gap. Therefore, the inside of the first gap 40 is not filled with adhesive or the like. The maximum distance D1 between the narrow portion 352 and the outer end surface 224 (the bottom surface of the recess 24a in FIG. 3) is, but is not limited to, greater than the thickness of the narrow portion 352. In the example shown in FIG. 6B, the maximum distance D1 between the narrow portion 352 and the outer end surface 224 is at least twice the thickness of the narrow portion 352. However, the maximum distance D1 between the narrow portion 352 and the outer end surface 224 (the bottom surface of the recess 24a in FIG. 3) may be equal to or smaller than the thickness of the narrow portion 352.

[0063] The mounting portion 36 is disposed along the bottom surface 221 so as to extend parallel to the bottom surface 221. The mounting portion 36 is perpendicular to the narrow portion 352. The mounting portion 36 is a portion that is connected to a land pattern of a mounting board (not shown) by, for example, solder or a conductive adhesive.

[0064] The mounting portion 36 is spaced apart from the bottom surface 221. Therefore, a second gap 50 is formed between the mounting portion 36 and the bottom surface 221. The second gap 50 is, but is not limited to, an air gap. Therefore, the inside of the second gap 50 is not filled with adhesive. The minimum distance D2 between the mounting portion 36 and the bottom surface 221 is, but is not limited to, smaller than the thickness of the mounting portion 36. However, the minimum distance D2 between the mounting portion 36 and the bottom surface 221 may be equal to the thickness of the mounting portion 36 or may be larger than the thickness.

[0065] The maximum distance D1 between the narrow portion 352 and the outer end surface 224 is longer than the minimum distance D2 between the mounting portion 36 and the bottom surface 221. The maximum distance D1 between the narrow portion 352 and the outer end surface 224 is not particularly limited, but may be two or more times the minimum distance D2 between the mounting portion 36 and the bottom surface 221.

[0066] As shown in Fig. 5, the shape of the mounting portion 36 when viewed in the Z-axis direction is a square, but it may also be a rectangle, another polygon, or another shape. As shown in Fig. 6A, the mounting portion 36 has the same width (horizontal width: width in the Y-axis direction) as the adhesive portion 350 when viewed in the X-axis direction. However, the width of the mounting portion 36 may be larger than the width W1 of the narrow portion 352 and smaller than the width W2 of the adhesive portion 350.

[0067] As shown in Fig. 5, the wire connection part 37 has a bottom part 370 and a pair of clamping parts 372. As shown in Fig. 6B, the bottom part 370 is disposed along the top surface 222. As shown in Fig. 5, the pair of clamping parts 372 are formed on both sides of the bottom part 370 in the Y-axis direction, and are configured to be bendable relative to the bottom part 370. The tips of the clamping parts 372 are bent.

[0068] The clamping portions 372 of terminal 31 sandwich the lead portion 12a arranged on the bottom portion 370. The clamping portions 372 of terminal 32 sandwich the lead portion 15a arranged on the bottom portion 370. The clamping portions 372 of terminal 33 sandwich the lead portion 12b arranged on the bottom portion 370. The clamping portions 372 of terminal 34 sandwich the lead portion 15b arranged on the bottom portion 370. The lead portions 12a, 12b, 15a, and 15b may be connected to the connecting portion 37 by soldering, a conductive adhesive, thermocompression bonding, ultrasonic bonding, resistance brazing, ultraviolet-curing resin bonding, laser welding, or the like, as necessary. The configuration of the connecting portion 37 is not limited to the configuration shown in FIG. 5 . For example, the clamping portions 372 may be omitted from the connecting portion 37.

[0069] Next, a method for manufacturing the coil device 1 shown in Fig. 1 will be described. First, the wire 10, wire 13, core 20, terminals 31 to 34, and cover 60 shown in Figs. 1 and 2 are prepared. The length of the core 20 in the X-axis direction is not particularly limited, but is, for example, 5.0 to 20 mm. The length of the core 20 in the Y-axis direction is not particularly limited, but is, for example, 5.0 to 15 mm. The length of the core 20 in the Z-axis direction is not particularly limited, but is, for example, 1.0 to 8.0 mm.

[0070] Next, adhesive is used to bond adhesive portion 350 of terminal 31 shown in FIG. 5 to outer end surface 224 of flange portion 22a (bottom surface of recess 24a) shown in FIG. 3. Also, adhesive is used to bond adhesive portion 350 of terminal 32 to outer end surface 224 of flange portion 22a (bottom surface of recess 25a). Also, adhesive is used to bond adhesive portion 350 of terminal 33 to outer end surface 224 of flange portion 22b (bottom surface of recess 24b). Also, adhesive is used to bond adhesive portion 350 of terminal 34 to outer end surface 224 of flange portion 22b (bottom surface of recess 25b). The adhesive is not particularly limited, but may be, for example, an epoxy adhesive.

[0071] Next, as shown in FIG. 2, wire 10 is wound around winding core 21a. Then, lead-out portion 12a is connected to connection portion 37 of terminal 31, and lead-out portion 12b is connected to connection portion 37 of terminal 33. Furthermore, wire 13 is wound around winding core 21b. Then, lead-out portion 15a is connected to connection portion 37 of terminal 32, and lead-out portion 15b is connected to connection portion 37 of terminal 34. Next, as shown in FIG. 1, cover 60 is attached to core 20. In this manner, coil device 1 can be manufactured.

[0072] In the coil device 1 of this embodiment, when the mounting portion 36 is connected to a mounting substrate (not shown), if the mounting substrate is deformed (for example, the mounting substrate is twisted), the following effect is obtained. That is, as shown in FIGS. 6A and 6B , at least a portion of the narrow portion 352 (in this embodiment, the entire narrow portion 352) is not bonded to the outer end surface 224, and therefore the narrow portion 352 is easily deformed as the mounting substrate is deformed. In particular, since the narrow portion 352 has a width W1 narrower than the adhesive portion 350, it can deform more easily than the adhesive portion 350. Therefore, stress generated by deformation of the mounting substrate (hereinafter simply referred to as "stress") is absorbed by the terminal 31 due to the deformation of the narrow portion 352 and is less likely to be transmitted to the core 20. This makes it less likely that excessive stress will be applied to the core 20, thereby preventing damage to the core 20.

[0073] Furthermore, since the adhesive portion 350 has a width W2 wider than the narrow portion 352, the adhesive area of ​​the adhesive portion 350 is ensured, and it is possible to increase the adhesive strength between the adhesive portion 350 and the outer end surface 224. In this way, with the coil device 1 of the present embodiment, it is possible to increase the adhesive strength of the terminal 31 to the core 20 and prevent damage to the core 20.

[0074] Furthermore, the narrow width portion 352 is closer to the mounting portion 36 than the adhesive portion 350 and is continuous with the mounting portion 36. Therefore, the stress is absorbed by the narrow width portion 352 before it travels from the mounting portion 36 to the adhesive portion 350. Therefore, the stress is less likely to be transmitted to the adhesive portion 350, and it is possible to prevent the stress from being transmitted to the core 20 via the adhesive portion 350.

[0075] Furthermore, the flange portion 22a has a first side surface 225 (FIG. 3) that is perpendicular to the outer end surface 224 and the bottom surface 221. The fixing portion 35 has a first edge portion 356 and a second edge portion 358 that is farther from the first side surface 225 than the first edge portion 356. The terminal 31 has a notch portion 38 formed in the first edge portion 356 along the narrow width portion 352. According to experiments conducted by the present inventors, when the notch portion 38 is formed in the first edge portion 356, stress is less likely to be transmitted to the core 20 via the narrow width portion 352 than when the notch portion 38 is formed in the second edge portion 358. This makes it possible to effectively prevent damage to the core 20.

[0076] Furthermore, the narrow width portion 352 protrudes in a direction away from the outer end surface 224. As a result, a first gap 40 is formed between the narrow width portion 352 and the outer end surface 224, making it difficult for stress to be transmitted to the core 20 via the narrow width portion 352. Furthermore, the narrow width portion 352 becomes more easily deformed, making it easier for the stress to be absorbed by the terminal 31. Therefore, in this respect as well, it is difficult for stress to be transmitted to the core 20 via the narrow width portion 352. This makes it possible to effectively prevent damage to the core 20.

[0077] Furthermore, the mounting portion 36 is spaced apart from the bottom surface 221. Therefore, a second gap 50 is formed between the mounting portion 36 and the bottom surface 221, making it difficult for stress to be transmitted to the core 20 via the mounting portion 36. This effectively prevents damage to the core 20.

[0078] Furthermore, a first gap 40 is formed between the narrow width portion 352 and the outer end surface 224, and a second gap 50 is formed between the mounting portion 36 and the bottom surface 221. The maximum distance D1 between the narrow width portion 352 and the outer end surface 224 is longer than the minimum distance D2 between the mounting portion 36 and the bottom surface 221. Therefore, the mounting portion 36 can stably support the core 20. Furthermore, stress is less likely to be transmitted to the core 20 via the narrow width portion 352, which effectively prevents damage to the core 20.

[0079] The coil device 1 further includes a cover 60 attached to the core 20 and covering the top surface 222 opposite the bottom surface 221 and the winding core portion 21a. As shown in FIG. 1, the cover 60 has a flat plate portion 61 parallel to the top surface 222. Therefore, during the manufacture of the coil device 1, the coil device 1 can be transported while the flat plate portion 61 is sucked by a suction device. The flat plate portion 61 can also protect the core 20 and the wire 10.

[0080] Second embodiment The terminals of the coil device of the second embodiment shown in Fig. 7A have the same configuration as the terminals of the coil device 1 of the first embodiment, except for the following points. Portions that overlap with the terminals of the coil device 1 of the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted. For simplicity, only terminals 31A and 32A are shown in Fig. 7A.

[0081] Terminals 31A and 32A have mounting portions 36A. When viewed in the X-axis direction, mounting portions 36A have the same width (horizontal width: width in the Y-axis direction) as narrow portions 352. However, mounting portions 36A may have a width narrower than narrow portions 352 when viewed in the X-axis direction.

[0082] This embodiment also provides the same effects as the first embodiment. Additionally, in this embodiment, the mounting portion 36A has the same width as the narrow portion 352 when viewed in the X-axis direction. This makes the mounting portion 36A more susceptible to deformation, and stress is more easily absorbed by the terminal 31A. This makes it difficult for stress to be transmitted to the core 20 (FIG. 3) via the mounting portion 36A, effectively preventing damage to the core 20.

[0083] Third embodiment The terminals of the coil device of the third embodiment shown in Fig. 7B have the same configuration as the terminals of the coil device 1 of the first embodiment, except for the following points. Portions that overlap with the terminals of the coil device 1 of the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted. For simplicity, only terminal 31B is shown in Fig. 7B.

[0084] Terminal 31B has not only notch 38 but also notch 39. Notch 39 is formed in second edge 358 along narrow portion 352. That is, in this embodiment, notch 38 and 39 are formed on both sides of narrow portion 352 in the Y-axis direction. The size of notch 39 is equal to the size of notch 38. Therefore, the shape of one side of terminal 31B relative to the center in the Y-axis direction is equal to the shape of the other side. When viewed in the X-axis direction, mounting portion 36A has the same width (horizontal width: width in the Y-axis direction) as narrow portion 352.

[0085] In this embodiment, the same effects as in the first embodiment can be obtained. Additionally, in this embodiment, in addition to the notch 38, the terminal 31B has a notch 39 formed in the second edge 358 along the narrow width portion 352. This improves the symmetry of the fixing portion 35 in the width direction (the direction in which the first edge 356 and the second edge 358 face each other). This ensures the strength (stability) of the fixing portion 35.

[0086] Fourth embodiment The coil device 1C of the fourth embodiment shown in Fig. 8 has the same configuration as the coil device 1 of the first embodiment, except for the following points. The same reference numerals are used to designate parts that overlap with the coil device 1 of the first embodiment, and detailed descriptions thereof will be omitted.

[0087] The coil device 1C has terminals 31C to 34C. As shown in Fig. 9, terminals 31C and 32C have fixed portions 35C. Although detailed illustration is omitted, terminals 33C and 34C also have fixed portions 35C. Fixed portion 35C differs from fixed portion 35 of the first embodiment in that it has a narrow portion 352C.

[0088] The narrow portion 352C is located on the same plane as the adhesive portion 350. That is, the adhesive portion 350 and the narrow portion 352C extend parallel to each other in a plane parallel to the YZ plane. The narrow portion 352C is continuous with the adhesive portion 350 without bending. The shape of the narrow portion 352C when viewed from the X-axis direction is rectangular, but it may also be a square or another polygon.

[0089] As shown in FIG. 10 , the narrow width portion 352C is disposed parallel to the outer end surface 224 (the bottom surface of the recess 24a). When viewed in the Y-axis direction, the adhesive portion 350 and the narrow width portion 352C extend linearly along the Z-axis. The adhesive portion 350 is adhered to the outer end surface 224 with the adhesive 70, while the narrow width portion 352C is not adhered to the outer end surface 224 with the adhesive 70. However, for example, the adhesive attached to the adhesive portion 350 may inevitably extend to the narrow width portion 352C, thereby adhering a portion of the narrow width portion 352C to the outer end surface 224 with the adhesive. Even in such a case, it is desirable that, for example, 80% or 90% or more of the area of ​​the narrow width portion 352C is not adhered to the outer end surface 224 with the adhesive.

[0090] The narrow width portion 352C may be in contact with the outer end surface 224. Alternatively, a minute gap (for example, a gap with a width corresponding to the thickness of the adhesive 70) may be formed between the narrow width portion 352C and the outer end surface 224.

[0091] In this embodiment, the same effects as in the first embodiment can be obtained. Additionally, in this embodiment, the narrow portion 352C is located on the same plane as the adhesive portion 350. Therefore, the narrow portion 352C does not bend relative to the adhesive portion 350, but extends parallel to the adhesive portion 350. This improves the strength of the narrow portion 352C, and allows the terminal 35C to stably support the core 20 (FIG. 3).

[0092] The present disclosure is not limited to the above-described embodiments, and various modifications can be made within the scope of the present disclosure.

[0093] For example, in each of the above embodiments, the coil device 1 is applied to a filter, but the coil device 1 may also be applied to other electronic components (for example, a transformer).

[0094] In each of the above-described embodiments, as shown in Fig. 6B, the second gap 50 between the mounting portion 36 and the bottom surface 221 is not filled with the adhesive 70. However, the adhesive 70 may be present in the second gap 50 to the extent that the effect of the present invention is not impaired.

[0095] In each of the above embodiments, the narrow width portion 352 shown in FIG. 6A may have a through-hole or slit formed therein, penetrating the narrow width portion 352 from one main surface to the other main surface of the narrow width portion 352.

[0096] The techniques described in the second and third embodiments may be applied to the coil device 1C of the fourth embodiment. In the third embodiment, the terminal 31B of Fig. 7B may be provided with the mounting portion 36 (Fig. 5) instead of the mounting portion 36A. [Explanation of symbols]

[0097] 1,1C...Coil device 10,13…wire 11, 14... Winding section 12a, 12b, 15a, 15b...Drawer part 20...Core 21a, 21b…Winling core part 22a, 22b…Tsubabe 221...Bottom 222…Top surface 223…Inner end surface 224...Outer end surface 225…1st side 226…Second side 23a, 23b...Convex part 24a, 24b, 25a, 25b...recesses 26a, 26b...fitting recess 31~34,31A,32A,31B,31C~34C...Terminal 35,35C…Fixed part 350...Adhesive part 352,352C…Narrow part 354...Bend 356...First edge 358...Second edge 36, 36A... Mounting section 37...Connection section 370…Bottom 372...Holding part 38, 39...Notch 40...First gap 50...Second gap 60...Cover 61...Flat plate part 62,63...Side 64a~64d…legs 65a~65d...claw part 66a, 66b...Convex part 67...Fitting protrusion 70...Adhesive 72…Application area

Claims

1. an annular core having a winding core portion and a flange portion formed at an axial end portion of the winding core portion; a wire wound around the winding core; a terminal attached to the flange and connected to the lead-out portion of the wire, the flange portion has an outer end surface perpendicular to the axial direction and a bottom surface facing a mounting substrate, the terminal has a fixing portion disposed along the outer end surface and a mounting portion disposed along the bottom surface, the fixing portion has an adhesive portion that is adhered to the outer end surface and a narrow portion that has a width narrower than that of the adhesive portion, At least a portion of the narrow width portion is not bonded to the outer end surface.

2. The coil device according to claim 1 , wherein the narrow portion is closer to the mounting portion than the adhesive portion and is continuous with the mounting portion.

3. the flange portion has a side surface perpendicular to the outer end surface and the bottom surface, the fixing portion has a first edge portion and a second edge portion that is farther from the side surface than the first edge portion, The coil device according to claim 1 or 2, wherein the terminal has a first notch formed in the first edge along the narrow portion.

4. The coil device according to claim 3 , wherein the terminal has, in addition to the first notch, a second notch formed in the second edge along the narrow portion.

5. The coil device according to claim 1 or 2, wherein the narrow portion protrudes in a direction away from the outer end surface.

6. The coil device according to claim 1 or 2, wherein the mounting portion is spaced apart from the bottom surface.

7. a first gap is formed between the narrow portion and the outer end surface; a second gap is formed between the mounting portion and the bottom surface; The coil device according to claim 1 or 2, wherein a maximum distance between the narrow portion and the outer end surface is longer than a minimum distance between the mounting portion and the bottom surface.

8. The coil device according to claim 1 , wherein the narrow portion is located on the same plane as the adhesive portion.

9. The coil device according to claim 1 or 2, wherein the mounting portion has the same width as the narrow portion.

10. a cover attached to the core and covering the top surface opposite the bottom surface and the winding core portion; The coil device according to claim 1 or 2, wherein the cover has a flat plate portion parallel to the top surface.

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