Coil device

Abstract

To provide a coil device having high mounting reliability.SOLUTION: A coil device 1 has: a coil 10 having a winding part 11 around which a wire 14 is wound, and a lead-out part 12a lead out from the winding part 11; a core 20 having a winding core part 21 provided with the winding part 11, and a flange part 22a formed on an end in a first direction parallel to a shaft core of the winding core part 21; and a terminal tool 30a fixed to at least a first surface 221 of the flange part. The first surface 221 has a step part 23, a first region 24 which is positioned between one end in a second direction vertical to a first direction of the flange part 22a and the step part 23, and a second region 25 which is positioned between the other end in the second direction of the flange part 22a and the step part 23, and is recessed to the first region 24. The terminal tool 30a has a mounting part 31 which is arranged in the first region 24 and can be connected to the substrate, a line connection part 32 that is arranged in the second region 25 and to which the lead-out part 12a is connected, and a connection part 33 which is arranged in the step part 23 and is connected to the mounting part 31 and the line connection part 32.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a coil device having a terminal tool.

Background Art

[0002] Conventionally, a coil device in which a terminal tool is provided on a flange portion of a core has been known (Patent Document 1). In the coil device of Patent Document 1, the terminal tool has a mounting portion that can be connected to a substrate and a connection portion to which a lead-out portion of the coil is connected. The mounting portion is connected to the substrate via a connecting material such as solder. The lead-out portion is connected to the connection portion by, for example, solder or laser welding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the mounting portion and the connection portion are close to each other as in the coil device of Patent Document 1, when connecting the lead-out portion to the connection portion, the heat applied to the connection portion (for example, heat from solder or laser welding) can reach the mounting portion. In particular, in a small coil device, if excessive heat is propagated to the mounting portion, the connection reliability between the mounting portion and the substrate may decrease, and the mounting reliability of the coil device may decrease.

[0005] In view of such a situation, the present disclosure has been made, and its object is to provide a coil device with high mounting reliability.

Means for Solving the Problems

[0006] To achieve the above object, the coil device of the present disclosure includes a coil having a winding portion formed by winding a wire and a lead-out portion drawn from the winding portion, A core having a winding core portion on which the winding portion is provided, and a flange portion formed at the end of the winding core portion in a first direction parallel to the axis of the winding core portion, It has at least a terminal that is fixed to the first surface of the flange, The first surface has a stepped portion, a first region located between the stepped portion and one end of the flange portion in a second direction perpendicular to the first direction, and a second region located between the stepped portion and the other end of the flange portion in the second direction and the stepped portion, which is recessed relative to the first region. The terminal device has a mounting portion located in the first region and connectable to a substrate, a connecting portion located in the second region to which the lead portion is connected, and a connecting portion located in the stepped portion and continuous with the mounting portion and the connecting portion.

[0007] In the coil device of this disclosure, a stepped portion is formed on the first surface of the flange portion. The terminal has a mounting portion and a connecting portion, as well as a connecting portion positioned on the stepped portion and continuous with the mounting portion and the connecting portion. Therefore, when mounting the coil device to a substrate, for example, a fillet can be formed in the connecting portion, and the mounting portion and further the connecting portion can be connected to the substrate via a connecting material. This improves the reliability of the connection between the mounting portion and the substrate, and enables the realization of a coil device with high mounting reliability. Furthermore, when connecting the lead portion to the connecting portion, the connecting portion can prevent excessive heat from reaching the mounting portion. Therefore, in this respect as well, the reliability of the connection between the mounting portion and the substrate can be improved.

[0008] The length of the mounting portion in the second direction may be longer than the length of the connecting portion in the second direction. In this case, it becomes easier to secure the area of ​​the mounting portion, and consequently the contact area between the mounting portion and the substrate, thereby improving the reliability of the connection between the mounting portion and the substrate.

[0009] The length of the mounting portion in the second direction may be at least half the length of the flange portion in the second direction. In this case as well, it becomes easier to secure the area of ​​the mounting portion, and consequently the contact area between the mounting portion and the substrate, thereby improving the reliability of the connection between the mounting portion and the substrate. Furthermore, when the mounting portion is connected to the substrate, the stability of the coil device relative to the substrate can be improved (wobbling can be prevented).

[0010] The mounting portion may extend along the second direction from the stepped portion or its vicinity to one end of the flange portion, and the connecting portion may extend along the second direction from the stepped portion or its vicinity to the other end of the flange portion. In this case, it becomes easier to secure the area of ​​the mounting portion, and consequently the bonding area between the mounting portion and the substrate, thereby improving the reliability of the connection between the mounting portion and the substrate. Furthermore, it becomes easier to secure the area of ​​the connecting portion, improving the connection strength of the lead portion to the connecting portion, and increasing the degree of freedom in the connection position of the lead portion to the connecting portion.

[0011] The flange portion comprises a first flange portion formed at one end of the winding core portion in the first direction and a second flange portion formed at the other end of the winding core portion in the first direction. The terminal device comprises a first terminal device and a second terminal device, and a single first terminal device may be fixed to the first flange portion, and a single second terminal device may be fixed to the second flange portion. By fixing a single first terminal device (second terminal device) to the first flange portion (second flange portion), it becomes easier to secure the area of ​​the mounting portion, and consequently the contact area between the mounting portion and the substrate, compared to the case where multiple first terminal devices (second terminal devices) are fixed to the first flange portion (second flange portion), thereby improving the reliability of the connection between the mounting portion and the substrate.

[0012] The stepped portion has a first stepped portion and a second stepped portion, the first flange portion has the first stepped portion, and the second flange portion has the second stepped portion, and the first stepped portion and the second stepped portion may be located on opposite sides in the second direction with respect to the axis of the winding core portion. In this case, compared to the case where the first stepped portion and the second stepped portion are located on the same side in the second direction with respect to the axis of the winding core portion, the stability of the coil device with respect to the substrate can be improved (wobbling can be prevented) when the coil device is mounted on the substrate.

[0013] At least a portion of the terminal may be connected to the first surface via an adhesive layer. In this case, it is possible to prevent the terminal from detaching from the core.

[0014] The mounting portion is connected to the first region via the adhesive layer, and the connecting portion is not connected to the second region via the adhesive layer, and a gap may be formed between the connecting portion and the second region. In this case, even if there is a manufacturing error in the dimensions of the terminal, that manufacturing error can be absorbed by the gap. This improves the mounting stability of the terminal to the flange.

[0015] The flange portion has an outer end surface opposite to the inner end surface to which the winding core portion is connected in the first direction, and the terminal may be continuous with the mounting portion and have an auxiliary mounting portion arranged on the outer end surface. In this case, for example, the mounting portion and further to the auxiliary mounting portion can be connected to the substrate via a connecting material while forming a fillet in the auxiliary mounting portion. This can reinforce the connection strength between the mounting portion and the substrate.

[0016] The stepped portion is inclined with respect to the first and second regions, and the connecting portion may extend diagonally along the stepped portion with respect to the mounting portion and the connecting portion. In this case, the mounting portion and the connecting portion are separated along the second direction according to the inclination angle of the connecting portion. This makes it less likely for excessive heat to reach the mounting portion when connecting the lead portion to the connecting portion. Furthermore, by inclining the connecting portion, it becomes easier to secure the area of ​​the connecting portion, and the amount of fillet formed in the connecting portion can be increased.

[0017] The flange portion has an outer end surface opposite to the inner end surface to which the winding core portion is connected in the first direction, a part of the joint portion protrudes outward in the first direction from the outer end surface, and the lead portion may be connected to the joint portion via a connecting material outside the outer end surface in the first direction. For example, when connecting the lead portion to the joint portion by laser welding, by irradiating the joint portion with a laser outside the outer end surface in the first direction from the outer end surface, it is possible to prevent the laser from hitting the flange portion and avoid damage to the core.

[0018] The mounting portion includes a projection that protrudes inward in the first direction from the connecting portion, and the length of the projection in the second direction is at least half the length of the flange portion in the second direction. In this case, the area of ​​the mounting portion can be expanded according to the area of ​​the projection. This expands the contact area between the mounting portion and the substrate, thereby improving the connection reliability between the mounting portion and the substrate.

[0019] The lead portion may be drawn out from a position outside the winding core in the second direction, along the first direction, toward the connecting portion. In this case, the lead portion can be drawn out toward the connecting portion at a position spaced apart from the mounting portion. Therefore, when mounting the coil device on a circuit board, it is possible to prevent connecting materials such as solder from adhering to the lead portion, thereby preventing the occurrence of short-circuit defects.

[0020] The distance along the first direction between the end of the winding portion in the first direction and the flange portion may be equal to or greater than the wire diameter of the wire. In this case, since the winding portion and the flange portion are separated in the first direction, when the coil device is mounted on the substrate, it is possible to prevent the connecting material from adhering to the winding portion, thereby preventing the occurrence of short - circuit defects.

Brief Description of the Drawings

[0021] [Figure 1] FIG. 1 is a perspective view of a coil device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of the core shown in FIG. 1. [Figure 3] FIG. 3 is a perspective view of the terminal shown in FIG. 1. [Figure 4] FIG. 4 is a side view of the coil device shown in FIG. 1 as viewed from the X - axis direction. [Figure 5] FIG. 5 is a plan view of the coil device shown in FIG. 1. [Figure 6] FIG. 6 is a side view of the coil device shown in FIG. 1 as viewed from the Y - axis direction.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present disclosure will be described while referring to the drawings. Note that the content shown in the drawings is merely schematic and exemplary for the purpose of understanding the present disclosure, and the appearance, dimensional ratios, etc. may be different from the actual object. Also, the present disclosure is not limited to the following embodiments.

[0023] The coil device 1 shown in FIG. 1 functions as, for example, an inductor and is mounted on the power supply etc. of various electrical devices. The coil device 1 has a coil 10, a core 20, and terminal fittings 30a and ʺ30bʺ. The coil device 1 may have a core 40 in addition to these members.

[0024] The coil 10 has a winding section 11 formed by winding a wire 14 into a coil shape, and lead-out sections 12a and 12b drawn out from the winding section 11. The wire 14 may be an insulated coated wire, for example, a copper wire coated with an insulating coating 13. The diameter of the wire 14 is not particularly limited, but is for example 10 to 300 μm. The coating 13 may be removed at the lead-out sections 12a and 12b.

[0025] As shown in Figure 2, the core 20 is a drum core and has a winding core portion 21 and flange portions 22a and 22b. The material of the core 20 is a metal or a magnetic material such as ferrite, but is not particularly limited. In the drawing, the X axis is the axis corresponding to the axial direction of the winding core portion 21. The Y axis is the axis corresponding to the direction perpendicular to the axial direction of the winding core portion 21 when the core 20 is viewed from above. The Z axis is an axis perpendicular to the X and Y axes. Hereafter, for each of the X, Y, and Z axes, the direction toward the center of the core 20 is referred to as "inside", and the direction away from the center of the core 20 is referred to as "outside". The size of the core 20 is not particularly limited, but for example, the length of the core 20 in the X axis direction is 1 to 6 mm, the length of the core 20 in the Y axis direction is 0.5 to 3 mm, and the length of the core 20 in the Z axis direction is 0.5 to 3 mm.

[0026] A winding section 11 (Figure 1) is provided on the winding core 21. The cross-sectional shape of the winding core 21 perpendicular to the axial direction is not particularly limited, but is circular or polygonal (e.g., octagonal). A flange 22a is formed on one end of the winding core 21 in the X-axis direction, and a flange 22b is formed on the other end of the winding core 21 in the X-axis direction. The flanges 22a and 22b have symmetrical shapes. In the following, to avoid redundant descriptions, matters common to both flanges 22a and 22b may be described only for flange 22a.

[0027] The flange portion 22a has at least a mounting surface 221, a non-mounting surface 222, an inner end surface 223, and an outer end surface 224. Similarly, the flange portion 22b has at least a mounting surface 221, a non-mounting surface 222, an inner end surface 223, and an outer end surface 224. The mounting surface 221 and the non-mounting surface 222 are located on opposite sides with respect to the Z-axis direction. The inner end surface 223 and the outer end surface 224 are located on opposite sides with respect to the X-axis direction. The winding core portion 21 is connected to the inner end surface 223.

[0028] The mounting surface 221 has a stepped portion 23, a first region 24 on one side of the stepped portion 23 in the Y-axis direction, and a second region 25 on the other side of the stepped portion 23 in the Y-axis direction. The first region 24 is located between one end of the mounting surface 221 in the Y-axis direction and the stepped portion 23. Most of the first region 24 is a flat surface (a surface parallel to the XY plane). The second region 25 is located between the other end of the mounting surface 221 in the Y-axis direction and the stepped portion 23. The second region 25 is recessed relative to the first region 24, and a recess 26 is formed in the second region 25. Therefore, the second region 25 is located closer to the non-mounting surface 222 than the first region 24. Most of the second region 25 is a flat surface (a surface parallel to the XY plane).

[0029] The stepped portion 23 is continuous with the first region 24 and the second region 25, and is located between the first region 24 and the second region 25 with respect to the Y-axis direction. The stepped portion 23 is inclined with respect to the first region 24 and the second region 25. The inclination angle θ of the stepped portion 23 with respect to the first region 24 (second region 25) is 0° < θ ≤ 90°. However, the inclination angle θ may also be 0° < θ < 90°, 45° < θ ≤ 90°, or 45° < θ < 90°. The stepped portion 23 extends along the X-axis from the position of the inner end face 223 to the position of the outer end face 224.

[0030] The length L1 in the Y-axis direction of the first region 24 may be greater than the length L2 in the Y-axis direction of the second region 25. Also, the length L1 in the Y-axis direction of the first region 24 may be greater than the sum of the length L2 in the Y-axis direction of the second region 25 and the length L3 in the Y-axis direction of the stepped portion 23. For example, the length L1 in the Y-axis direction of the first region 24 is 1 / 2 or more of the length L4 in the Y-axis direction of the mounting surface 221 (flange portion 22a), or greater than 1 / 2.

[0031] A notch (chamfer) 27 may be formed on the outer edge of the mounting surface 221. The notch 27 is formed in a stepped shape, but the shape of the notch 27 is not particularly limited. In the example shown in Figure 2, the notch 27 is formed on all four sides of the rectangle formed by the mounting surface 221 in plan view, but it may be formed on any one, two, or three sides. The notch 27 has the function of preventing cracks, chips, etc. from occurring on the outer edge of the flange 22a. The notch 27 may also be formed on the non-mounting surface 222.

[0032] The stepped portion 23 of the flange portion 22a and the stepped portion 23 of the flange portion 22b are located on opposite sides of the Y-axis with respect to the axis of the winding core portion 21. That is, the stepped portion 23 of the flange portion 22a is located on the positive Y-axis side of the axis of the winding core portion 21, while the stepped portion 23 of the flange portion 22b is located on the negative Y-axis side of the axis of the winding core portion 21.

[0033] Under this configuration, compared to the case where the stepped portion 23 of flange portion 22a and the stepped portion 23 of flange portion 22b are located on the same side in the Y-axis direction with respect to the axis of the winding core portion 21, the stability of the coil device 1 with respect to the substrate (not shown; the same applies hereinafter) can be improved (the coil device 1 can not wobble to one side in the Y-axis direction) when the coil device 1 is mounted on the substrate. Note that the stepped portion 23 of flange portion 22a and the stepped portion 23 of flange portion 22b may be located on the same side in the Y-axis direction with respect to the axis of the winding core portion 21.

[0034] The first region 24 of the flange portion 22a is offset to the negative Y-axis side relative to the axis of the winding core portion 21, while the first region 24 of the flange portion 22b is offset to the positive Y-axis side relative to the axis of the winding core portion 21. Similarly, the second region 25 of the flange portion 22a is offset to the positive Y-axis side relative to the axis of the winding core portion 21, while the second region 25 of the flange portion 22b is offset to the negative Y-axis side relative to the axis of the winding core portion 21. Therefore, in plan view, the shape of the core 20 is point-symmetric (180-degree rotational symmetry). However, the first region 24 of the flange portion 22a and the first region 24 of the flange portion 22b may be located on the same side in the Y-axis direction with respect to the axis of the winding core portion 21. Similarly, the second region 25 of the flange portion 22a and the second region 25 of the flange portion 22b may be located on the same side in the Y-axis direction with respect to the axis of the winding core portion 21.

[0035] As shown in Figure 3, terminal 30a has a mounting portion 31, a connecting portion 32, and a linking portion 33. In addition to these, terminal 30a may also have an auxiliary mounting portion 34 and a protruding portion 35. Similarly, terminal 30b has a mounting portion 31, a connecting portion 32, and a linking portion 33. In addition to these, terminal 30b may also have an auxiliary mounting portion 34 and a protruding portion 35. At least a part of terminal 30a may be made of a conductor such as metal. The same applies to terminal 30b. The thickness of terminals 30a and 30b is not particularly limited, but is 50 to 300 μm. Terminals 30a and 30b have the same shape. In the following, to avoid redundant descriptions, items common to terminals 30a and 30b may be described only for terminal 30a. In this embodiment, "identical" or "equal" is not limited to strictly equal, but rather allows for errors of, for example, ±5% or ±10%.

[0036] As shown in Figures 2 and 3, the mounting portion 31 is the part connected to the substrate and is positioned in the first region 24 of the mounting surface 221. The mounting portion 31 is connected to the substrate via a connecting material such as solder or conductive adhesive. The mounting portion 31 may be positioned only in the first region 24, or a part of the mounting portion 31 may be exposed outside the first region 24 (for example, the stepped portion 23). The mounting portion 31 has a surface parallel to the first region 24 and is fixed in a position facing the first region 24. In this embodiment, "parallel" is not limited to strictly parallel, but rather allows for errors of, for example, ±5 degrees or ±10 degrees. Similarly, "perpendicular" or "orthogonal" is not limited to strictly perpendicular, but rather allows for errors of, for example, ±5 degrees or ±10 degrees.

[0037] The mounting portion 31 is bonded to the first region 24 via an adhesive (for example, an epoxy adhesive). This forms an adhesive layer between the mounting portion 31 and the first region 24, preventing the terminal 30a from detaching from the flange portion 22a. A gap may be formed between the mounting portion 31 and the first region 24 at the location of the notch 27.

[0038] As shown in Figure 4, the Y-axis length L5 of the mounting portion 31 may be longer than the Y-axis length L6 of the connecting portion 32. Furthermore, the Y-axis length L5 of the mounting portion 31 may be longer than the sum of the Y-axis length L6 of the connecting portion 32 and the Y-axis length L7 of the connecting portion 33. In this case, it becomes easier to secure the area of ​​the mounting portion 31, and consequently the bonding area between the mounting portion 31 and the substrate, thereby improving the reliability of the connection between the mounting portion 31 and the substrate.

[0039] The Y-axis length L5 of the mounting portion 31 may be equal to or less than the Y-axis length L1 of the first region 24 (Figure 2). That is, the Y-axis length L5 of the mounting portion 31 may be 1 / 2 or more of the Y-axis length L4 of the mounting surface 221 (flange portion 22a), or it may be greater than 1 / 2. Alternatively, the Y-axis length L5 of the mounting portion 31 may be 1 / 2 or more of the total Y-axis length of the terminal fitting 30a, or it may be greater than 1 / 2. In this case, when the mounting portion 31 is connected to the substrate, the stability of the coil device 1 with respect to the substrate can be improved (wobbling can be prevented).

[0040] The mounting portion 31 may extend from the stepped portion 23 (or near the stepped portion 23) to one end of the flange portion 22a on the negative Y-axis side. In this case, it becomes easier to secure the area of ​​the mounting portion 31, and consequently the contact area between the mounting portion 31 and the substrate, thereby improving the reliability of the connection between the mounting portion 31 and the substrate. However, a gap may be formed between one end of the mounting portion 31 on the negative Y-axis side and one end of the flange portion 22a on the negative Y-axis side.

[0041] As shown in Figure 3, the mounting portion 31 may include a protrusion 35 that protrudes inward in the X-axis direction from the connecting portion 33. The protrusion length of the protrusion 35 in the X-axis direction may be 5% to 25% of the total length of the mounting portion 31 (including the protrusion 35) in the X-axis direction. The length of the protrusion 35 in the Y-axis direction may be 1 / 2 or more of the Y-axis length L4 of the mounting surface 221 (flange portion 22a) shown in Figure 4, or it may be greater than 1 / 2. Alternatively, the length of the protrusion 35 in the Y-axis direction may be 1 / 2 or more of the total length of the terminal 30a in the Y-axis direction, or it may be greater than 1 / 2. In this case, the area of ​​the mounting portion 31 can be expanded according to the area of ​​the protrusion 35. This expands the bonding area between the mounting portion 31 and the substrate, improving the connection reliability between the mounting portion 31 and the substrate. Furthermore, since the adhesive area between the mounting portion 31 and the mounting surface 221 can be expanded, the adhesive reliability between the terminal 30a and the mounting surface 221 can be improved.

[0042] As shown in Figure 5, the projection 35 may be located outside the outer edge of the flange 22a, more specifically, outside the intersection of the mounting surface 221 and the inner end surface 223, in the X-axis direction. That is, the projection 35 may not be exposed outside the outer edge of the flange 22a, and may be located inside the outer edge of the flange 22a. In this case, the winding portion 11 or the lead portion 12a is less likely to come into contact with the projection 35, thereby preventing damage to the wire 14. A portion of the projection 35 may be located on the notch 27.

[0043] The total length L8 of the mounting portion 31 (including the protruding portion 35) in the X-axis direction is greater than, but may be equal to, the length of the connecting portion 33 in the X-axis direction. Also, the total length L8 of the mounting portion 31 in the X-axis direction is less than, but may be equal to, or greater than, the length L9 of the mounting surface 221 (flange portion 22a) in the X-axis direction. The outer end of the mounting portion 31 in the X-axis direction is located inward in the X-axis direction from the outer edge of the flange portion 22a, or more specifically, from the intersection of the mounting surface 221 and the outer end surface 224. However, the outer end of the mounting portion 31 in the X-axis direction may be exposed outside the outer edge of the flange portion 22a. In this case, the area of ​​the mounting portion 31 can be secured.

[0044] As shown in Figures 3 and 4, the auxiliary mounting portion 34 is continuous with the mounting portion 31 and is positioned on the outer end surface 224. The auxiliary mounting portion 34 is connected to the outer end of the mounting portion 31 in the X-axis direction and is perpendicular to the mounting portion 31. The length of the auxiliary mounting portion 34 in the Y-axis direction is equal to the length L5 of the mounting portion 31 in the Y-axis direction, but may be smaller. As shown in Figure 6, a gap 70 is formed between the auxiliary mounting portion 34 and the outer end surface 224. However, at least a portion of the auxiliary mounting portion 34 may be in contact with the outer end surface 224. Alternatively, adhesive may be filled into the gap 70 to ensure the adhesive strength between the terminal 30a and the flange portion 22a. A fillet of a connecting material such as solder or conductive adhesive is formed in the auxiliary mounting portion 34. In this way, by connecting the auxiliary mounting portion 34 to the substrate via a connecting material, the connection strength between the mounting portion 31 and the substrate can be reinforced.

[0045] As shown in Figures 4 and 5, the connecting portion 32 is the portion to which the lead portion 12a or 12b is connected, and is located in the second region 25 of the mounting surface 221. The connecting portion 32 may be located only in the second region 25, or a part of the connecting portion 32 may be exposed outside the second region 25 (for example, in the stepped portion 23). The connecting portion 32 has a surface parallel to the second region 25 and is fixed facing the second region 25.

[0046] Unlike the mounting portion 31, the connecting portion 32 is not bonded to the mounting surface 221 (second region 25) via adhesive. Therefore, a gap 50 (Figure 4) is formed between the connecting portion 32 and the second region 25. By forming a gap 50 between the connecting portion 32 and the second region 25 in this way, even if there is a manufacturing error in the dimensions of the terminal fitting 30a, that manufacturing error can be absorbed by the gap 50. This improves the mounting stability of the terminal fitting 30a to the flange portion 22a.

[0047] However, the connecting portion 32 may be bonded to the mounting surface 221 (second region 25) via an adhesive, similar to the mounting portion 31. Alternatively, at least a portion of the connecting portion 32 may be in contact with the mounting surface 221 (second region 25) without being bonded with an adhesive.

[0048] The connecting portion 32 may extend from the vicinity of the stepped portion 23 (or from the stepped portion 23) to the other end of the flange portion 22a on the positive Y-axis side. In this case, it becomes easier to secure the area of ​​the connecting portion 32, improving the connection strength of the lead portion 12a to the connecting portion 32, and increasing the degree of freedom in the connection position of the lead portion 12a to the connecting portion 32. However, a gap may be formed between the other end of the connecting portion 32 on the positive Y-axis side and the other end of the flange portion 22a on the positive Y-axis side.

[0049] The length L6 in the Y-axis direction of the connecting section 32 is greater than the length L7 in the Y-axis direction of the connecting section 33, but it may be equal to or less than L7. The length in the X-axis direction of the connecting section 32 is equal to the length L9 in the X-axis direction of the mounting surface 221, but it may be less than or greater than L9.

[0050] The inner end of the splice section 32 in the X-axis direction may be located inward in the X-axis direction from the outer edge of the flange section 22a, or more specifically, from the intersection of the mounting surface 221 and the inner end surface 223. That is, the inner end of the splice section 32 in the X-axis direction may be located inward from the outer edge of the flange section 22a without being exposed outside the outer edge of the flange section 22a. In this case, the winding section 11 or the lead-out section 12a is less likely to come into contact with the inner end of the splice section 32 in the X-axis direction, thereby preventing damage to the wire 14. The inner end of the splice section 32 in the X-axis direction may also be located inward in the X-axis direction from the notch 27.

[0051] A portion of the connecting portion 32 may protrude outward in the X-axis direction from the connecting portion 33, perpendicular to the connecting portion 33. A portion of the connecting portion 32 (the outer end of the connecting portion 32 in the X-axis direction) may protrude outward in the X-axis direction from the outer end surface 224. The length of the connecting portion 32 protruding from the outer end surface 224 in the X-axis direction may be 10% to 50% of the total length of the connecting portion 32 in the X-axis direction. In this case, the area of ​​the connecting portion 32 can be secured. However, the outer end of the connecting portion 32 in the X-axis direction may be positioned inward in the X-axis direction from the outer end surface 224.

[0052] The lead portion 12a is connected to the joint portion 32 by, for example, soldering, laser welding, thermocompression bonding, ultrasonic bonding, resistance brazing, or UV-curing resin bonding. The same applies to the lead portion 12b. In this embodiment, since the lead portion 12a is connected to the joint portion 32 by laser welding, a weld ball 60 is formed at the connection position of the lead portion 12a. The lead portion 12a may also be connected to the joint portion 32 via the weld ball 60, outside the outer end face 224 in the X-axis direction. In this case, when connecting the lead portion 12a to the joint portion 32, the laser can be irradiated toward the joint portion 32, outside the outer end face 224 in the X-axis direction. This prevents the laser from hitting the flange portion 22a and avoids damage to the core 20.

[0053] The connecting portion 33 is positioned along the stepped portion 23 and is continuous with the mounting portion 31 and the connecting portion 32. The connecting portion 33 may be positioned only on the stepped portion 23, or a part of the connecting portion 33 may be exposed to the outside of the stepped portion 23 (for example, the second region 25). When the coil device 1 is mounted on the substrate, a fillet of a connecting material such as solder or conductive adhesive is formed on the connecting portion 33. The connecting portion 33 has a surface parallel to the stepped portion 23 and is positioned facing the stepped portion 23. The connecting portion 33, like the connecting portion 32, is not bonded to the mounting surface 221 (stepped portion 23) via adhesive. Therefore, a gap 50 (Figure 4) is formed between the connecting portion 33 and the mounting surface 221 (stepped portion 23). The gap 50 between the connecting portion 33 and the stepped portion 23 is continuous with the gap 50 between the connecting portion 32 and the second region 25.

[0054] The connecting portion 33 may be bonded to the mounting surface 221 (step portion 23) via adhesive, similar to the mounting portion 31. Alternatively, at least a part of the connecting portion 33 may be in contact with the mounting surface 221 (step portion 23) without being bonded with adhesive.

[0055] The connecting portion 33 extends diagonally along the stepped portion 23 toward the mounting portion 31 and the connecting portion 32. In this case, the mounting portion 31 and the connecting portion 32 are separated along the Y-axis according to the inclination angle of the connecting portion 33. This makes it less likely for excessive heat to reach the mounting portion 31 when connecting the lead portion 12a to the connecting portion 32, and ensures the ease of connection of the mounting portion 31 to the connecting material (e.g., solder wettability). Furthermore, by inclining the connecting portion 33, it becomes easier to secure the area of ​​the connecting portion 33, and the amount of fillet formed in the connecting portion 33 can be increased.

[0056] The inclination angle of the connecting portion 33 with respect to the mounting portion 31 and / or the connecting portion 32 is equal to the inclination angle of the stepped portion 23 with respect to the first region 24 and / or the second region 25, but may be smaller or larger than this. The inclination angle θ of the connecting portion 33 with respect to the mounting portion 31 (connecting portion 32) is 0° < θ ≤ 90°. However, the inclination angle θ may also be 0° < θ < 90°, 45° < θ ≤ 90°, or 45° < θ < 90°.

[0057] The length of the connecting portion 33 in the X-axis direction is smaller than the length L9 of the mounting surface 221 in the X-axis direction, but may be equal to or greater than it. The length of the connecting portion 33 in the X-axis direction is not particularly limited, but for example, it is between 1 / 3 and 1 times the length L9 of the mounting surface 221 in the X-axis direction. The connecting portion 33 is located inside the outer edge of the flange portion 22a. More specifically, the connecting portion 33 is located outside the intersection of the mounting surface 221 and the inner end surface 223 in the X-axis direction, and inside the intersection of the mounting surface 221 and the outer end surface 224 in the X-axis direction. However, a part of the connecting portion 33 may be exposed outside the outer edge of the flange portion 22a. The connecting portion 33 may also be located inside the notch 27 formed on the outer edge of the mounting surface 221.

[0058] The lead portion 12a may be drawn out toward the splice portion 32 from a position outside the winding core portion 21 in the Y-axis direction (outer circumferential surface on the positive Y-axis side of the winding core portion 21) in a direction parallel to the X-axis. Similarly, the lead portion 12b may be drawn out toward the splice portion 32 from a position outside the winding core portion 21 in the Y-axis direction (outer circumferential surface on the negative Y-axis side of the winding core portion 21) in a direction parallel to the X-axis. In this case, the lead portion 12a can be drawn toward the splice portion 32 at a position spaced apart from the mounting portion 31. Therefore, when mounting the coil device 1 on the substrate, it is possible to prevent the connecting material from adhering to the lead portion 12a. This prevents the dissolution of the coating 13 on the lead portion 12a and prevents the occurrence of short-circuit defects.

[0059] Near the weld ball 60, the coating 13 of the lead-out portion 12a positioned (placed) on the joint portion 32 is peeled off. At a position away from the weld ball 60, the coating 13 of the lead-out portion 12a positioned (placed) on the joint portion 32 may remain without being peeled off. Similarly, near the weld ball 60, the coating 13 of the lead-out portion 12b positioned (placed) on the joint portion 32 is peeled off. At a position away from the weld ball 60, the coating 13 of the lead-out portion 12b positioned (placed) on the joint portion 32 may remain without being peeled off.

[0060] The length L10 in the X-axis direction between the end of the winding portion 11 in the X-axis direction and the flange portion 22b (the same applies to the flange portion 22a) is not particularly limited, but is, for example, 1 or more times the wire diameter of the wire 14, or 2 or more times. In this case, since the winding portion 11 and the flange portion 22b are spaced apart in the X-axis direction, it is possible to prevent connecting materials such as solder from adhering to the winding portion 11 when mounting the coil device 1 on a substrate, thereby preventing the occurrence of short-circuit defects.

[0061] As shown in Figure 6, a gap 80 is formed between the lead-out portion 12a and the mounting surface 221 (second region 25). However, the lead-out portion 12a may be extended along the inner end surface 223, the mounting surface 221, and the connecting wire portion 32 so that no gap 80 is formed between it and the mounting surface 221. The same applies to the lead-out portion 12b.

[0062] As shown in Figure 1, the core 40 has a rectangular parallelepiped shape (plate shape). The core 40 may be made of the same material as the core 20, or it may be made of a different material. The core 40 is attached to the core 20 by adhesive. More specifically, the core 40 is fixed to the non-mounted surface 222 of the flange portion 22a and the non-mounted surface 222 of the flange portion 22b. Notches may be formed on the outer edges of the main surface of the core 40 to which the non-mounted surface 222 is fixed, and on the outer edge of the main surface on the opposite side. This is to prevent cracks, chips, etc. from occurring on the outer edge of the core 40.

[0063] Next, the manufacturing method of the coil device 1 will be described. First, the wire 14, core 20, and terminals 30a and 30b shown in Figure 1 are prepared. Next, the mounting portion 31 of the terminal 30a is bonded to the mounting surface 221 of the flange portion 22a with adhesive, fixing the terminal 30a to the mounting surface 221. Also, the mounting portion 31 of the terminal 30b is bonded to the mounting surface 221 of the flange portion 22b with adhesive, fixing the terminal 30b to the mounting surface 221. Next, the wire 14 is wound around the winding core portion 21 to form the winding portion 11. Next, for example, by laser welding, the lead portion 12a is connected to the connecting portion 32 of the terminal 30a, and the lead portion 12b is connected to the connecting portion 32 of the terminal 30b. More specifically, the lead-out portion 12a or 12b is connected to the outer end of the joint portion 32 in the X-axis direction (the portion of the joint portion 32 that protrudes outward in the X-axis direction beyond the outer end surface 224). Next, if necessary, the core 40 is bonded to the non-mounted surface 222 of the flange portion 22a and the non-mounted surface 222 of the flange portion 22b with adhesive. In this manner, the coil device 1 can be manufactured.

[0064] As shown in Figure 1, in the coil device 1 of this embodiment, when mounting the coil device 1 to a substrate, for example, a fillet can be formed in the connecting portion 33, and the mounting portion 31 and further the connecting portion 33 can be connected to the substrate via a connecting material. This improves the reliability of the connection between the mounting portion 31 and the substrate, and enables the realization of a coil device 1 with high mounting reliability. Furthermore, when connecting the lead portion 12a to the connecting portion 32, the connecting portion 33 can prevent excessive heat from reaching the mounting portion 31. This prevents a decrease in the ease of connection (e.g., solder wettability) of the mounting portion 31 to the connecting material, and improves the reliability of the connection between the mounting portion 31 and the substrate.

[0065] Furthermore, since excessive heat is less likely to be transferred from the connecting portion 32 to the mounting portion 31, deterioration of the adhesive layer between the mounting portion 31 and the mounting surface 221 (first region 24) can be prevented. This improves the adhesive strength (adhesion reliability) between the terminal portion 30a (terminal fitting 30b) and the flange portion 22a (flange portion 22b).

[0066] Furthermore, in this embodiment, a single terminal 30a is fixed to the flange portion 22a, and a single terminal 30b is fixed to the flange portion 22b. Therefore, compared to the case where multiple terminals 30a (terminals 30b) are fixed to the flange portion 22a (flange portion 22b), it becomes easier to secure the area of ​​the mounting portion 31, and consequently the contact area between the mounting portion 31 and the substrate, thereby improving the reliability of the connection between the mounting portion 31 and the substrate.

[0067] This disclosure is not limited to the embodiments described above, and can be modified in various ways within the scope of this disclosure.

[0068] In the above embodiment, an example of applying the coil device 1 to an inductor was described, but the coil device 1 may also be applied to a coil device other than an inductor (for example, a transformer).

[0069] In the above embodiment, the core 40 may be omitted from the coil device 1. [Explanation of Symbols]

[0070] 1... Coil device 10... Coil 11...Route 12a, 12b…Drawer part 13...Coating 14…Wire 20,40...cores 21...Core section 22a, 22b…Tsubabe 221…Implementation aspects 222...Unimplemented aspects 223…Inner end surface 224...Outer end surface 23... Stepped section 24...First area 25…Second area 26…recess 27... Notch 30a,30b…terminal fitting 31…Implementation Department 32...Connection section 33...Connection part 34... Auxiliary implementation section 35...Protrusion 50, 70, 80... gaps 60... Welding ball

Claims

1. A coil having a winding section formed by winding a wire, and a pull-out section drawn out from the winding section, A core having a winding core portion on which the winding portion is provided, and a flange portion formed at the end of the winding core portion in a first direction parallel to the axis of the winding core portion, It has at least a terminal that is fixed to the first surface of the flange, The first surface has a stepped portion, a first region located between the stepped portion and one end of the flange portion in a second direction perpendicular to the first direction, and a second region located between the stepped portion and the other end of the flange portion in the second direction and the stepped portion, which is recessed relative to the first region. The terminal device has a mounting portion located in the first region and connectable to a substrate, a connecting portion located in the second region to which the lead portion is connected, and a connecting portion located in the stepped portion and continuous with the mounting portion and the connecting portion. The first region is formed at one end of the flange in the second direction, and the second region is formed at the other end of the flange in the second direction. The stepped portion is inclined with respect to the first region and the second region. The connecting portion extends diagonally along the stepped portion with respect to the mounting portion and the connecting wire portion. A gap is formed between the connecting portion and the stepped portion. The length of the mounting portion in the second direction is longer than the length of the connecting portion in the second direction. Coil device.

2. The coil device according to Claim 1, wherein the length of the connecting portion in the direction perpendicular to the axis of the winding core portion is the same as or longer than the length of the connecting wire portion in the direction perpendicular to the axis of the winding core portion.

3. The coil device according to claim 1 or 2, wherein the length of the mounting portion in the second direction is 1 / 2 or more of the length of the flange portion in the second direction.

4. The mounting portion extends along the second direction from the stepped portion or its vicinity to one end of the flange portion, The coil device according to claim 1 or 2, wherein the connecting portion extends along the second direction from the stepped portion or its vicinity to the other end of the flange portion.

5. The flange portion consists of a first flange portion formed at one end of the core portion in the first direction and a second flange portion formed at the other end of the core portion in the first direction. The aforementioned terminal consists of a first terminal and a second terminal. A single first terminal is fixed to the first flange portion. The coil device according to claim 1 or 2, wherein a single second terminal is fixed to the second flange portion.

6. The stepped portion has a first stepped portion and a second stepped portion. The first flange portion has the first stepped portion, The second flange portion has the second stepped portion, The coil device according to claim 5, wherein the first stepped portion and the second stepped portion are located on opposite sides in the second direction with respect to the axis of the winding core portion.

7. The coil device according to claim 1 or 2, wherein at least a portion of the terminal is connected to the first surface via an adhesive layer.

8. The mounting portion is connected to the first region via the adhesive layer, The aforementioned joint portion is not connected to the second region via the adhesive layer. The coil device according to claim 7, wherein a gap is formed between the connecting portion and the second region.

9. The flange portion has an outer end surface opposite to the inner end surface to which the winding core portion is connected in the first direction. The coil device according to claim 1 or 2, wherein the terminal is continuous with the mounting portion and has an auxiliary mounting portion arranged on the outer end face.

10. The coil device according to claim 1 or 2, wherein the connecting portion protrudes from the stepped portion to a part of the second region.

11. The flange portion has an outer end surface opposite to the inner end surface to which the winding core portion is connected in the first direction. A portion of the connecting wire portion protrudes outward in the first direction from the outer end surface. The coil device according to claim 1 or 2, wherein the extension portion is connected to the connecting portion via a connecting member on an outward side in the first direction from the outer end face.

12. The mounting portion includes a protrusion that protrudes inward in the first direction from the connecting portion. The coil device according to claim 1 or 2, wherein the length of the protruding portion in the second direction is 1 / 2 or more of the length of the flange portion in the second direction.

13. The coil device according to claim 1 or 2, wherein the draw-out portion is drawn out from a position outside the winding core portion in the second direction, along the first direction, toward the connecting portion.

14. The coil device according to claim 1 or 2, wherein the distance along the first direction between the end of the winding portion in the first direction and the flange portion is equal to or greater than the wire diameter of the wire.

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