JP7498909B2 - Coil component, electronic device, and method for manufacturing coil component - Google Patents

Description

The present invention relates to coil components, electronic devices, and methods for manufacturing coil components.

Coil components are known in which the end of a conductor wire is joined to a part of a metal plate in order to electrically connect the conductor wire that forms the winding portion to a terminal electrode made of a metal plate (for example, Patent Documents 1 to 3).

JP 2008-10752 A JP 2018-41852 A JP 2018-56399 A

In the coil components described in Patent Documents 1 to 3, it is not possible to confirm whether the conductor is joined at a sufficient length to the joint where the conductor and the metal plate are joined. If the conductor is not joined at a sufficient length, the reliability of the electrical connection and mechanical connection between the conductor and the terminal electrode decreases.

The present invention was developed in consideration of the above problem, and aims to make it possible to check whether the conductor wires are joined at a sufficient length.

The present invention is a coil component comprising: a base portion; a winding portion formed from a conductor wound around a portion of the base portion; a terminal electrode formed from a metal plate on the surface of the portion of the base portion and connected to the conductor drawn out from the winding portion; and a joint portion at which an end of the conductor is joined to a portion of the metal plate and electrically connects the conductor and the terminal electrode, wherein a tip of the conductor protrudes from the joint portion by a length of 0.05 mm or more when viewed in plan on the surface of the base portion on which the joint portion is provided, and the tip of the conductor protruding from the joint portion has a core wire covered with an insulating coating.

In the above configuration, a tip end of the conductor may overlap the terminal electrode and protrude from the joint when the surface of the base portion on which the joint is provided is viewed in plan .

In the above configuration, the tip end of the conductor can be configured to be within a range that overlaps with the base portion and protrudes from the joint when the surface of the base portion on which the joint is provided is viewed in a planar view.

In the above configuration, the terminal electrode can be configured to have a locking portion that locks the conductor.

In the above configuration, the base portion is a core including a winding core portion and a flange portion provided at the axial end of the winding core portion, the terminal electrode is disposed on the flange portion, the conductor is wound around the winding core portion to form the winding portion and is drawn out from the winding core portion to the terminal electrode disposed on the flange portion, and the joint portion can be formed on the flange portion.

The present invention is an electronic device comprising the coil component described above and a circuit board on which the coil component is mounted.

The present invention is a method for manufacturing a coil component, comprising the steps of: placing a terminal metal plate having a metal plate body and joining claws extending from the metal plate body on a base portion; winding a conductor around a part of the base portion to form a wound portion; and joining the conductor and the joining claws so that a tip of the conductor is positioned outside the joining claws to form a joint that electrically connects the conductor and the terminal metal plate, wherein when the surface of the base portion on which the joint is formed is viewed in a plane, the tip of the conductor protrudes from the joint by a length of 0.05 mm or more , and the tip of the conductor protruding from the joint has its core wire covered with an insulating coating.

In the above configuration, after the step of forming the joint, a step of cutting off a part or all of the tip of the conductor protruding from the joint can be included.

The above configuration may include a step of locking the conductor with a locking claw of the terminal metal plate so that the tip of the conductor is positioned outside the connecting claw.

The present invention makes it possible to check whether the conductor wires are joined at a sufficient length.

FIG. 1 is a diagram showing a coil component according to a first embodiment of the present invention. FIG. 2 is a perspective view showing a coil component according to a second embodiment of the present invention. 3A is a view of the coil component of FIG. 2 as seen from the side indicated by the arrow F1, and FIG. 3B is a view as seen from the side indicated by the arrow F2. 4A and 4B are cross-sectional views of the flange portion of the coil component of FIG. FIG. 5 is a diagram for explaining the terminal metal plate of the coil component of FIG. 2. As shown in FIG. FIG. 6 is a diagram showing an example of a joint portion. 7A and 7B are diagrams (part 1) for explaining a method for manufacturing a coil component according to a second embodiment of the present invention. 8A and 8B are diagrams (part 2) for explaining a method for manufacturing a coil component according to the second embodiment of the present invention. FIG. 9 is a perspective view showing a coil component according to a third embodiment of the present invention. FIG. 10 is a diagram for explaining a joint portion of the coil component shown in FIG. FIG. 11 is a diagram showing an electronic device including a coil component according to the second embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings as appropriate. Components common to multiple drawings are given the same reference numerals throughout the multiple drawings. Please note that the drawings are not necessarily drawn to scale for ease of explanation.

1 is a diagram showing a coil component 500 according to a first embodiment of the present invention. As shown in FIG. 1, the coil component 500 includes a base portion 1, a winding portion 2, a terminal electrode 4, and a joint portion 5. The winding portion 2 is formed by winding a conductor 3 around a part of the base portion 1. The terminal electrode 4 is made of a metal plate 6 and is provided on the surface of a part of the base portion 1. The joint portion 5 is formed by joining an end of the conductor 3 to a part of the metal plate 6, and electrically joins the conductor 3 and the terminal electrode 4. A tip surface 7, which is a cross section at the tip of the conductor 3, is exposed from the joint portion 5. The tip surface 7 is a cross section of the tip of the conductor 3, and can be visually recognized as having a shape almost identical to the cross-sectional shape of the conductor 3, or as a trace of the cross section of the conductor 3. In addition, when the conductor 3 and the metal plate 6 are formed of materials with different components, the tip surface 7 can be identified from the difference in components.

In this way, the tip surface 7, which is the cross section at the tip of the conductor 3, is exposed from the joint 5, so it can be confirmed that the conductor 3 is joined to the joint 5 at a sufficient length.

A coil part 600 according to a second embodiment of the present invention will be described with reference to Fig. 2, Fig. 3(a) and Fig. 3(b), and Fig. 4(a) and Fig. 4(b). Fig. 2 is a perspective view showing a coil part 600 according to a second embodiment of the present invention. Fig. 3(a) is a view of the coil part 600 from the arrow F1 side in Fig. 2, and Fig. 3(b) is a view of the coil part 600 from the arrow F2 side in Fig. 2. In Figs. 3(a) and 3(b), a part of the winding part 30 is omitted in order to clearly show the winding core part 12. Fig. 4(a) is a cross-sectional view of the coil part 600 at the flange part 14, and Fig. 4(b) is a cross-sectional view of the flange part 16. As shown in Figures 2, 3(a) and 3(b), and 4(a) and 4(b), the coil component 600 is a common mode filter that includes a drum core 10, a winding portion 30, terminal electrodes 40, 42, 44, and 46, and joint portions 70, 72, 74, and 76.

The drum core 10 includes a winding core 12, a flange 14 provided at one end of the winding core 12 in the axial direction, and a flange 16 provided at the other end of the winding core 12 in the axial direction. The winding core 12 has, for example, a substantially rectangular cross-sectional shape, but may also have a polygonal shape such as a hexagon or octagon, or may have a circular or elliptical shape. The flanges 14 and 16 have, for example, a rectangular parallelepiped shape with a recess. The drum core 10 is formed of, for example, a Ni-Zn ferrite material, but may also be formed of other materials. For example, the drum core 10 may be formed of a Mn-Zn ferrite material, a soft magnetic alloy material such as a Fe-Si-Cr, Fe-Si-Al, or Fe-Si-Cr-Al, a magnetic metal material such as Fe or Ni, an amorphous magnetic metal material, or a nanocrystalline magnetic metal material.

The dimensions of the coil part 600 are, for example, 3.2 mm in length, 2.5 mm in width, and 2.5 mm in height. Here, the length of the coil part 600 is the dimension in the axial direction of the winding core part 12 of the drum core 10 (X direction in FIG. 2), the width is the dimension in the direction perpendicular to the X direction and parallel to the mounting surface (Y direction in FIG. 2), and the height is the dimension in the direction perpendicular to the X direction and the Y direction (Z direction in FIG. 2). The dimensions of the drum core 10 are, for example, 3.0 mm in length (dimension in the X direction in FIG. 2), 2.5 mm in width (dimension in the Y direction in FIG. 2), and 1.6 mm in height (dimension in the Z direction in FIG. 2). The dimensions of the winding core part 12 of the drum core 10 are, for example, 1.6 mm in width (dimension in the Y direction in FIG. 2) and 0.8 mm in height (dimension in the Z direction in FIG. 2).

The winding section 30 includes two conductors 32 and 34. The conductor 32 is wound around the winding core 12, one end of which is electrically connected to the terminal electrode 40, and the other end of which is electrically connected to the terminal electrode 46. The conductor 34 is wound around the winding core 12, one end of which is electrically connected to the terminal electrode 42, and the other end of which is electrically connected to the terminal electrode 44. The conductor 32 is wound around the winding core 12 on the conductor 34. The conductors 32 and 34 have a structure in which the peripheral surface of a core wire 36 made of, for example, copper is covered with an insulating coating 38 made of polyamideimide. The core wire 36 may be made of a metal other than copper, and may be made of, for example, silver, palladium, or a silver-palladium alloy. The insulating coating 38 may be made of an insulating material other than polyamideimide, and may be made of a resin material such as polyesterimide or polyurethane. The diameter of the conductors 32 and 34 is, for example, 0.05 mm. Conductive wires 32 and 34 are wound around winding core 12 the same number of turns.

The flange portion 14 has a lower surface 14A, an upper surface 14B, an end surface 14C, an end surface 14D, a side surface 14E, and a side surface 14F. The flange portion 16 has a lower surface 16A, an upper surface 16B, an end surface 16C, an end surface 16D, a side surface 16E, and a side surface 16F. The lower surface 14A and the lower surface 16A are the surfaces that face the circuit board when the coil component 600 is mounted on the circuit board. The side surface 14F and the side surface 16F are the surfaces to which the winding core portion 12 is connected.

A recess 18 is formed on the end face 14C of the flange 14, and a recess 20 is formed on the end face 14D. The recesses 18 and 20 are formed at a position that straddles the center of the end faces 14C and 14D in the vertical direction. The recesses 18 and 20 are formed, for example, so as to connect to the bottom surface portion from the end faces 14C and 14D via a tapered surface. The tapered surface and bottom surface of the recesses 18 and 20 are considered to be parts of the end faces 14C and 14D, respectively. The angle of the tapered surface of the end faces 14C and 14D is appropriately set depending on the direction in which the conductors 32 and 34 are drawn out. Similar to the recesses 18 and 20 formed on the flange 14, a recess 22 is formed on the end face 16C of the flange 16, and a recess 24 is formed on the end face 16D. The thickness of the flanges 14 and 16 is, for example, 0.6 mm. The depth of the recesses 18, 20, 22, and 24 is, for example, 0.5 mm, and the width of the bottom surface is, for example, 0.7 mm.

Terminal electrodes 40 and 42 are provided on flange portion 14. Terminal electrodes 44 and 46 are provided on flange portion 16. Terminal electrode 40 is made of terminal metal plate 50, and terminal electrode 42 is made of terminal metal plate 52. Terminal electrode 44 is made of terminal metal plate 54, and terminal electrode 46 is made of terminal metal plate 56. Terminal metal plates 50, 52, 54, and 56 are Sn-plated phosphor bronze plates, but other metals such as brass plates or tough pitch copper plates may also be used.

The terminal metal plate 50 extends from the lower surface 14A of the flange 14 through the side surface 14E to the upper surface 14B and into the recess 18 provided in the end surface 14C, and is attached to the flange 14. The terminal metal plate 52 extends from the lower surface 14A of the flange 14 through the side surface 14E to the upper surface 14B and into the recess 20 provided in the end surface 14D, and is attached to the flange 14. Similarly, the terminal metal plate 54 extends from the lower surface 16A of the flange 16 through the side surface 16E to the upper surface 16B of the flange 16 and into the recess 24 provided in the end surface 16D, and is attached to the flange 16. The terminal metal plate 56 extends from the lower surface 16A of the flange 16 through the side surface 16E to the upper surface 16B of the flange 16 and into the recess 22 provided in the end surface 16C, and is attached to the flange 16.

The terminal metal plate 50 will be described with reference to FIG. 5. FIG. 5 is a diagram for explaining the terminal metal plate 50 of the coil component 600. Note that since the terminal metal plates 52, 54, and 56 have the same structure as the terminal metal plate 50, only the terminal metal plate 50 will be described, and the description of the terminal metal plates 52, 54, and 56 will be omitted.

5, the terminal metal plate 50 includes a metal plate body 60, a locking claw 62 extending from the metal plate body 60, and a connecting claw 64 extending from the metal plate body 60 and spaced apart from the locking claw 62. The metal plate body 60 is attached to the surface of the flange 14 by pressing one end against the lower surface 14A of the flange 14 and pressing the other end against the upper surface 14B. The locking claw 62 and the connecting claw 64 are disposed in a recess 18 provided in the end surface 14C. The locking claw 62 is provided to sandwich and lock the conductor 32 between the metal plate body 60. The connecting claw 64 is provided to be joined to the conductor 32 by, for example, welding, and to electrically connect the conductor 32 and the terminal metal plate 50.

2, 3(a) and 3(b), and 4(a) and 4(b), one end of the conductor 32 and the joint claw 64 of the terminal metal plate 50 are joined by, for example, welding. This forms a ball-shaped joint 70, which electrically connects the conductor 32 and the terminal electrode 40. The other end of the conductor 32 and the joint claw 64 of the terminal metal plate 56 are joined by, for example, welding. This forms a ball-shaped joint 76, which electrically connects the conductor 32 and the terminal electrode 46. Similarly, one end of the conductor 34 and the joint claw 64 of the terminal metal plate 52 are joined to form a ball-shaped joint 72, which electrically connects the conductor 34 and the terminal electrode 42. The other end of the conductor 34 and the joint claw 64 of the terminal metal plate 54 are joined to form a ball-shaped joint 74, which electrically connects the conductor 34 and the terminal electrode 44. Joints 70, 72, 74, and 76 are welds if they are formed by welding, such as laser welding or arc welding.

The conductor 32 is held in place by being sandwiched between the winding portion 30 and the joint 70 and a locking portion 90 formed by bending the locking claws 62 of the terminal metal plate 50 and a base portion 80 formed by the metal plate body 60 of the terminal metal plate 50. The conductor 32 is held in place by being sandwiched between the winding portion 30 and the joint 76 and a locking portion 96 formed by bending the locking claws 62 of the terminal metal plate 56 and a base portion 86 formed by the metal plate body 60 of the terminal metal plate 56.

Similarly, the conductor 34 is held in place by being sandwiched between the winding portion 30 and the joint 72, and a locking portion 92 formed by bending the locking claw 62 of the terminal metal plate 52, and a base portion 82 formed by the metal plate body 60 of the terminal metal plate 52. The conductor 34 is held in place by being sandwiched between the winding portion 30 and the joint 74, and a locking portion 94 formed by bending the locking claw 62 of the terminal metal plate 54, and a base portion 84 formed by the metal plate body 60 of the terminal metal plate 54.

The conductor 32 has a predetermined length protruding from the joint 70 from the tip surface 32a, which is the cross section of one tip, and a predetermined length protruding from the joint 76 from the tip surface 32b, which is the cross section of the other tip. That is, one tip surface 32a of the conductor 32 is exposed from the joint 70, and the other tip surface 32b is exposed from the joint 76. Similarly, the conductor 34 has a predetermined length protruding from the tip surface 34a, which is the cross section of one tip, from the joint 72, and a predetermined length protruding from the tip surface 34b, which is the cross section of the other tip, from the joint 74. Therefore, one tip surface 34a of the conductor 34 is exposed from the joint 72, and the other tip surface 34b is exposed from the joint 74. The length of the parts of the conductors 32 and 34 protruding from the joints 70, 72, 74, and 76 is preferably 0.05 mm or more in terms of image processing. Also, to miniaturize the coil components, it is preferable for this length to be short, preferably 0.3 mm or less.

Figure 6 is a diagram showing an example of a joint 70. Note that the joints 72, 74, and 76 have the same structure as the joint 70, so only the joint 70 will be described, and the explanation of the joints 72, 74, and 76 will be omitted. As shown in Figure 6, the joint 70 is formed in a hemispherical shape on the base 80. Note that the hemispherical shape is not limited to a perfect hemispherical shape, but also includes a shape close to a hemispherical shape. By having the tip of the conductor 32 protrude from the hemispherical joint 70, the length of the protruding part is less likely to affect the dimensions of the coil component. In addition, the influence of reflection from the joint 70 when the tip of the conductor 32 is image-processed can be reduced, and the tip of the conductor 32 can be easily detected even if the protruding length is short.

In this way, in the coil component 600, the tip surfaces 32a and 32b of the conductor 32 are exposed from the joints 70 and 76, so that it is possible to confirm by visual inspection and image identification inspection with an inspection device that the conductor 32 is joined to the joints 70 and 76 at a sufficient length. Similarly, the tip surfaces 34a and 34b of the conductor 34 are exposed from the joints 72 and 74, so that it is possible to confirm by visual inspection and image identification inspection with an inspection device that the conductor 34 is joined to the joints 72 and 74 at a sufficient length. Conventionally, the tip surface of the conductor is contained within the joint and cannot be visually inspected from the outside, so that it is not possible to confirm the actual length of the conductor joined within the joint. For this reason, it was not possible to inspect the degree of electrical and mechanical connection between the conductor and the terminal electrode, and it was not possible to improve reliability. As in the coil component 600, the structure in which the tip surfaces 32a and 32b of the conductor 32 are exposed from the joints 70 and 76 can improve the reliability of the electrical connection and mechanical connection between the conductor 32 and the terminal electrodes 40 and 46, and the structure in which the tip surfaces 34a and 34b of the conductor 34 are exposed from the joints 72 and 74 can improve the reliability of the electrical connection and mechanical connection between the conductor 34 and the terminal electrodes 42 and 44.

As shown in FIG. 3(a), preferably, the tip of the conductor 32 protrudes from the joints 70 and 76. This makes it easy to check that the conductor 32 is of sufficient length to be joined to the joints 70 and 76. The same applies to the conductor 34.

As shown in FIG. 3(a), preferably, the tip of the conductor 32 protrudes from the joints 70 and 76 within a range that overlaps the drum core 10 when the surface of the drum core 10 on which the joints 70 and 76 are provided is viewed in plan. This prevents the tip of the conductor 32 from coming into contact with other members. The same applies to the conductor 34.

Next, a method for manufacturing the coil component 600 will be described. First, the drum core 10 is formed. For example, a binder is mixed with Ni-Zn ferrite material, and the mixture is compression molded in a molding die to obtain a drum-shaped molded body. If necessary, the molded body may be deburred. This molded body is sintered at a predetermined firing temperature to obtain a drum core 12 and flanges 14 and 16. Next, the terminal metal plates 50 and 52 are attached and arranged on the flange 14 of the drum core 10 by bending, crimping, etc. The terminal metal plates 54 and 56 are attached and arranged on the flange 16 of the drum core 10 by bending, crimping, etc. The conductor 34 is wound around the outer periphery of the winding core 12 of the drum core 10 the required number of times, and the conductor 32 is wound around the winding core 12 on the outside of the conductor 34 the required number of times to form the winding part 30. The conductor 32 and the conductor 34 are wound the same number of times. The ends of the conductor 32 are pulled out onto the terminal metal plates 50 and 56, and joined to electrically connect the conductor 32 to the terminal metal plates 50 and 56. Similarly, the ends of the conductor 34 are pulled out onto the terminal metal plates 52 and 54, and joined to electrically connect the conductor 34 to the terminal metal plates 52 and 54.

The method for manufacturing the coil component 600 will be described in detail with reference to Figs. 7(a) to 8(b). Figs. 7(a) to 8(b) are diagrams for explaining the method for manufacturing the coil component 600. Note that Figs. 7(a) to 8(b) illustrate and explain the vicinity of one end of the conductor 32 that is joined to the terminal metal plate 50, but the vicinity of the other end of the conductor 32 and the vicinity of both ends of the conductor 34 are the same, so their explanations will be omitted here.

As shown in FIG. 7(a), the terminal metal plate 50 having a metal plate body 60 and a locking claw 62 and a joining claw 64 extending from the metal plate body 60 is placed on the flange portion 14 of the drum core 10 by bending or the like. The conductor wires 32 and 34 are wound around the winding core portion 12 of the drum core 10 to form the winding portion 30. One end side of the conductor wire 32 is pulled out onto the metal plate body 60 of the terminal metal plate 50 using a jig 100 such as a clamp. Next, the insulating coating 38 of the portion of the conductor wire 32 that is sandwiched between the metal plate body 60 and the joining claw 64 is removed to expose the core wire 36. The insulating coating 38 can be removed, for example, by irradiating it with laser light.

As shown in FIG. 7(b), both the locking claws 62 and the connecting claws 64 are bent at room temperature, and the conductor 32 is clamped and fixed between the metal plate body 60, the locking claws 62, and the connecting claws 64.

As shown in FIG. 8(a), the conductor 32 is cut so that the tip of the conductor 32 is positioned outside the connecting claw 64. A commonly used method can be used to cut the conductor 32. For example, the conductor 32 may be cut by pressing using the terminal metal plate 50 and a jig used to bend the locking claw 62 and connecting claw 64. In this case, the bending of the locking claw 62 and connecting claw 64 and the cutting of the conductor 32 can be performed at the same time, reducing the manufacturing process.

As shown in FIG. 8(b), the conductor 32 and the joint claw 64 are joined in a state where the tip of the conductor 32 is located outside the joint claw 64. This forms a joint 70, which electrically connects the conductor 32 and the terminal metal plate 50. The conductor 32 and the joint claw 64 can be joined by welding such as laser welding or arc welding, but other methods such as thermocompression bonding, ultrasonic bonding, or solder bonding may also be used. As an example, the conductor 32 and the joint claw 64 can be joined by irradiating the joint claw 64 with laser light to melt the joint claw 64. When the joint claw 64 melts, the molten part rises, and the joint 70, which is a welded part that is rounded overall, is formed. Since the conductor 32 and the joint claw 64 are joined in a state where the tip of the conductor 32 is located outside the joint claw 64, a predetermined length portion of the tip surface 32a of the conductor 32 protrudes from the joint 70. Then, a portion of the tip of the conductor 32 protruding from the joint 70 may be cut off to shorten the length by which the tip of the conductor 32 protrudes from the joint 70, so that the tip of the conductor 32 protrudes from the joint 70 within the range that overlaps the drum core 10.

In the manufacturing method of this embodiment, an example is shown in which the insulating coating 38 is removed from the portion of the conductor 32 that corresponds to the joining claw 64, but depending on the material of the insulating coating 38, the step of removing the insulating coating 38 may not be necessary.

According to the manufacturing method of the coil component 600, as shown in Figs. 8(a) and 8(b), the tip of the conductor 32 is positioned outside the joining claw 64, and the conductor 32 and the joining claw 64 are joined to form a joining portion 70 that electrically connects the conductor 32 and the terminal metal plate 50. This allows the position of the conductor 32 relative to the joining claw 64 to be confirmed visually or with an inspection device that uses image recognition before joining the conductor 32 and the joining claw 64. This allows the joining to be performed reliably while confirming that a sufficient length of the conductor 32 is welded to the joining portion 70.

After forming the joint 70, a part of the tip of the conductor 32 protruding from the joint 70 may be cut to shorten the length by which the tip of the conductor 32 protrudes from the joint 70. For example, a part of the tip of the conductor 32 may be cut so that the tip of the conductor 32 protrudes from the joint 70 within the range that overlaps the drum core 10. This prevents the tip of the conductor 32 from contacting other members. Note that when cutting the conductor 32 in FIG. 8(a), the conductor 32 may be cut short in advance so that the tip of the conductor 32 protrudes from the joint 70 within the range that overlaps the drum core 10.

As shown in FIG. 7(b), preferably, the terminal metal plate 50 has a locking claw 62 extending from the metal plate body 60 separately from the joining claw 64 in addition to the joining claw 64, and the locking claw 62 locks the conductor 32 so that the tip of the conductor 32 is positioned outside the joining claw 64. This effectively prevents the position of the conductor 32 from moving relative to the joining claw 64 before and after the joining of the conductor 32 and the joining claw 64.

Figure 9 is a perspective view showing a coil part 700 according to a third embodiment of the present invention. Figure 10 is a diagram for explaining the joint 70 of the coil part 700. As shown in Figures 9 and 10, in the coil part 700, the tip of the conductor 32 does not protrude from the joints 70 and 76. One tip surface 32a of the conductor 32 is flush with the surface of the joint 70. The other tip surface 32b of the conductor 32 is also flush with the surface of the joint 76, but is not shown here. Similarly to the conductor 32, the tip of the conductor 34 does not protrude from the joints 72 and 74, and the tip surfaces 34a and 34b are flush with the surfaces of the joints 72 and 74, but is not shown here. The other configurations of the coil part 700 are the same as those of the coil part 600, so their description is omitted.

In the coil component 700, as shown in FIG. 10, the tip surface 32a of the conductor 32 is flush with the surface of the joint 70. Because the tip surface 32a of the conductor 32 and the surface of the joint 70 are made of different materials, even though they are flush with each other, the two can be distinguished based on differences in color, surface irregularities, and reflections. Therefore, even in this case, it is possible to confirm that the conductor 32 is joined to the joint 70 at a sufficient length by visual inspection and inspection with an inspection device that uses image recognition. In addition, the tip of the conductor 32 can be effectively prevented from coming into contact with other members.

The configuration in which the tip surface 32a of the conductor 32 is flush with the surface of the joint 70 can be obtained by forming the joint 70 as shown in FIG. 8(b) and then cutting off all of the tip of the conductor 32 protruding from the joint 70. Therefore, the tip surface 32a of the conductor 32 and the surface of the joint 70 being flush with each other is not limited to being completely flush, but also includes cases in which there is a step on the order of a manufacturing error in cutting the conductor 32.

Fig. 11 is a diagram showing an electronic device 800 including a coil component 600 according to a second embodiment of the present invention. As shown in Fig. 11, the electronic device 800 includes a circuit board 102 and a coil component 600 mounted on the circuit board 102. The coil component 600 is mounted on the circuit board 102 by joining the terminal electrodes 40, 42, 44, and 46 (only the terminal electrodes 40 and 46 are shown in Fig. 11) to the electrodes 104 of the circuit board 102 with solder 106.

In the electronic device 800, the coil component 600 is mounted on the circuit board 102. This makes it possible to obtain the electronic device 800 having the coil component 600, which allows confirmation that the conductors 32 and 34 are joined to the joints 70, 72, 74, and 76 with sufficient length. In other words, the electronic device 800 can be an electronic device in which a coil component is mounted with reduced joint defects, and can be an electronic device with improved reliability.

Note that while the electronic device 800 is shown as having the coil component 600 mounted on the circuit board 102, it may also be having the coil component 700 mounted thereon.

In the second and third embodiments, the coil component is a common mode filter, but this is not limited to this. The coil component may be other coil components, such as a single-line coil component. Although the base part is a drum core 10 having flanges 14 and 16 at both ends of the winding core part 12, this is not limited to this, and may be, for example, a core (T core) having a flange only at one end of the winding core part, or a non-core.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

REFERENCE SIGNS LIST 1 Base portion 2 Winding portion 3 Conductor 4 Terminal electrode 5 Joint portion 6 Metal plate 7 Tip surface 10 Drum core 12 Winding core portion 14, 16 Flange portion 18, 20, 22, 24 Recess 30 Winding portion 32, 34 Conductor 32a, 32b, 34a, 34b Tip surface 36 Core wire 38 Insulating coating 40, 42, 44, 46 Terminal electrode 50, 52, 54, 56 Terminal metal plate 60 Metal plate body 62 Locking claw 64 Joining claw 70, 72, 74, 76 Joint portion 80, 82, 84, 86 Base portion 90, 92, 94, 96 Locking portion 500, 600, 700 Coil component 800 Electronic device

Claims (9)

A base portion;
a winding portion formed of a conductive wire wound around a portion of the base portion;
a terminal electrode formed of a metal plate on a surface of a portion of the base portion and connected to the conductive wire drawn from the winding portion;
a joint portion at which an end of the conductor wire and a part of the metal plate are joined to electrically connect the conductor wire and the terminal electrode,
a tip end of the conductive wire protrudes from the joint by a length of 0.05 mm or more when the surface of the base portion on which the joint is provided is viewed in plan view,
A coil component, wherein a core wire of a tip portion of the conductor protruding from the joint portion when viewed in a plan view is covered with an insulating coating. The coil component according to claim 1, wherein the tip of the conductor overlaps the terminal electrode and protrudes from the joint when the surface of the base part on which the joint is provided is viewed in plan. The coil component according to claim 1, wherein the tip of the conductor is within a range that overlaps with the base portion and protrudes from the joint when the surface of the base portion on which the joint is provided is viewed in plan. The coil component according to any one of claims 1 to 3, wherein the terminal electrode has a locking portion that locks the conductor. the base portion is a core including a winding core portion and a flange portion provided at an end portion in an axial direction of the winding core portion,
The terminal electrode is disposed on the flange portion,
the conductive wire is wound around the winding core to form the winding portion and is led out from the winding core to the terminal electrode disposed on the flange portion,
The coil component according to claim 1 , wherein the joint portion is formed on the flange portion. The coil component according to any one of claims 1 to 5,
and a circuit board on which the coil component is mounted. a step of disposing a terminal metal plate having a metal plate body and a joining claw extending from the metal plate body on a base portion;
a step of winding a conductive wire around a portion of the base portion to form a winding portion;
and joining the conductor to the joining claws so that the tip end of the conductor is positioned outside the joining claws to form a joining portion that electrically connects the conductor to the terminal metal plate,
a tip portion of the conductor protruding from the joint by a length of 0.05 mm or more when the surface of the base portion on which the joint is formed is viewed in a plan view, and the tip portion of the conductor protruding from the joint is formed such that a core wire is covered with an insulating coating. The method for manufacturing a coil component according to claim 7, further comprising a step of cutting off a part or all of the tip of the conductor protruding from the joint after the step of forming the joint. The method for manufacturing a coil component according to claim 7 or 8, further comprising a step of locking the conductor with a locking claw of the terminal metal plate so that the tip of the conductor is positioned outside the joining claw.

Images