Method for manufacturing coil component

Abstract

To provide a manufacturing method of a wire-wound coil component capable of precisely controlling the joint position where the end of the winding is joined to an external electrode.SOLUTION: A manufacturing method of a coil component includes a core preparation step S11 of preparing a core having a winding core and a flange connected to one end of the winding core, a metal layer forming step S12 of forming a conductive metal layer on the surface of the flange, a jig arranging step S14 of arranging a first jig at a target position on the surface of the metal layer, and a joining step S15 of deforming the end such that the end is in contact with the first jig by applying pressure and heat to the end of the winding placed on the surface of the metal layer with the second jig, and joining the deformed end to the metal layer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The invention disclosed in this specification relates to a method for manufacturing a coil component. More specifically, the invention disclosed in this specification relates to a method for manufacturing a wound-type coil component.

Background Art

[0002] Wound-type coil components have been conventionally known. A wound-type coil component includes a core, a winding wound around the core, and a plurality of external electrodes. The core has a pair of flanges and a bobbin connecting the pair of flanges. The winding is wound around the bobbin. The winding is joined to each of the plurality of external electrodes at its end. A resin exterior portion covering the winding wound around the bobbin may be formed between the pair of flanges. Conventional wound-type coil components are described in, for example, JP-A-2014-170783 (Patent Document 1) and JP-A-2003-17336 (Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-cited Documents 1 and 2, the ends of the winding are joined to the external electrodes by thermocompression bonding. As described in paragraph

[0046] of Document 1, when the winding is thermocompression bonded, the position of the winding may deviate from the target position of the external electrode. If the winding is joined to the external electrode at a position deviated from the target position, there is a risk of problems such as the joining between the winding and the external electrode becoming uncertain or the winding wound around the bobbin becoming loose.

[0005] An object of the invention disclosed in this specification is to solve or alleviate at least a part of the above-described problems. One more specific object of the invention disclosed in this specification is to accurately control the joining position where the end of the winding is joined to the external electrode in the method for manufacturing a wound coil component.

[0006] The above and other objects of the present invention will become apparent throughout the description of this specification. The invention disclosed in this specification may solve problems grasped other than the description in the column of "Problems to be Solved by the Invention".

Means for Solving the Problems

[0007] A method for manufacturing a coil component according to one or more embodiments of the present invention includes a core preparation step of preparing a core having a bobbin and a flange connected to one end of the bobbin, a metal layer formation step of forming a conductive metal layer on the surface of the flange, a jig arrangement step of arranging a first jig at a target position on the surface of the metal layer, and a joining step of deforming an end of a winding arranged on the surface of the metal layer by pressing and heating with a second jig so that the end is in contact with the first jig and joining the deformed end to the metal layer.

[0008] In the jig arrangement step, the first jig may be pushed from the surface of the metal layer toward the inside at the target position.

[0009] In the joining step, the end may be arranged at a position on the surface of the metal layer that is distal from the axis of the bobbin and farther from the first jig.

[0010] In the joining step, the first jig may be kept at a lower temperature than the second jig.

[0011] In the joining step, the second jig may apply pressure to the end of the winding by moving toward the metal layer.

[0012] In the jig configuration step, a third jig may be disposed at a position where it interferes with the trajectory of the second jig on the surface of the metal layer. In the bonding step, the second jig may move toward the metal layer to a position where it contacts the third jig.

[0013] The diameter of the winding wire may be 0.02 mm or less. In the bonding step, the thickness of the bonded portion of the winding wire may be 1 / 2 or more of the diameter of the winding wire.

[0014] The first jig has a first surface orthogonal to the surface of the metal layer, and the bonded portion may be in contact with the first jig on the first surface. The distance from the upper end of the first surface to the metal layer may be greater than the diameter of the winding wire.

[0015] The method for manufacturing a coil component according to one or more embodiments of the present invention further includes a step of forming a conductive electrode layer so as to cover the metal layer and the bonded portion.

[0016] The method for manufacturing a coil component according to one or more embodiments of the present invention further includes a step of providing an insulating exterior portion so as to cover at least a part of the wound portion wound around the bobbin.

Advantages of the Invention

[0017] According to the method for manufacturing a coil component disclosed in the present specification, the bonding position where the end of the winding wire is bonded to the external electrode can be accurately controlled.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

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Figure 3b

Figure 3c

Figure 3d

Figure 3e

Figure 3f

Figure 4a

Figure 4b

Figure 4c

Figure 4d

Figure 4e

Figure 4f

Figure 5

Figure 6

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Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0019] Hereinafter, various embodiments of the present invention will be described with reference to the drawings as appropriate. In each drawing, the same reference numerals are assigned to the common components. Note that it should be noted that each drawing is not necessarily drawn to an exact scale for convenience of explanation. The embodiments of the present invention described below do not limit the invention according to the claims. The elements described in the following embodiments are not necessarily essential for the solution means of the invention.

[0020] Referring to FIG. 1, the wound coil component 1 will be described. FIG. 1 is a perspective view showing the wound coil component 1 to which the invention disclosed in this specification is applicable. In this specification, the wound coil component 1 may sometimes be simply referred to as the coil component 1.

[0021] The coil component 1 generally has a rectangular parallelepiped shape. As shown in the figure, the coil component 1 may be mounted on the mounting substrate 2a during use. Two land portions 3a and 3b are provided on the mounting substrate 2a. The coil component 1 includes external electrodes 21 and 22, and is mounted on the mounting substrate 2a by joining each of the external electrodes 21 and 22 to the corresponding land portions 3a and 3b of the mounting substrate 2a. In the illustrated embodiment, the coil component 1 is mounted on the mounting substrate 2a in a horizontal posture.

[0022] The circuit board 2 can be mounted on various electronic devices. The electronic devices on which the circuit board 2 can be mounted include smartphones, tablets, game consoles, automotive electrical components, servers, and various other electronic devices.

[0023] In FIG. 1, an L-axis direction, a W-axis direction, and a T-axis direction that are orthogonal to each other are shown. In this specification, the directions and arrangements of the components of the coil component 1 may be described with reference to the L-axis direction, the W-axis direction, and the T-axis direction shown in FIG. 1.

[0024] In one embodiment of the present invention, the coil component 1 is configured such that the dimensions in its L-axis direction, W-axis direction, and T-axis direction are all 1.0 mm or less. Thus, the coil component 1 can be configured to have small dimensions as a wound coil component.

[0025] As shown in the figure, the coil component 1 includes a core 10, a winding 25, external electrodes 21 and 22, and an exterior portion 40.

[0026] The core 10 has a bobbin 11, a flange 12a provided at one end of the bobbin 11, and a flange 12b provided at the other end of the bobbin 11. Thus, the bobbin 11 connects the flange 12a and the flange 12b. The bobbin 11 extends along an axis Ax extending along the L-axis direction.

[0027] In the illustrated embodiment, the bobbin 11 has a substantially quadrangular prism shape. The bobbin 11 can take any shape suitable for winding the winding 25. For example, the bobbin 11 can take a polygonal prism shape such as a triangular prism shape, a pentagonal prism shape, or a hexagonal prism shape, a cylindrical shape, an elliptical cylindrical shape, or a truncated cone shape.

[0028] The flanges 12a and 12b are each arranged to generally have a rectangular parallelepiped shape. The inner surfaces of the flange 12a and the flange 12b are arranged to face each other. The inner surfaces, outer surfaces of the flange 12a and the flange 12b, and the four surfaces connecting the inner surface and the outer surface may all be flat planes or curved surfaces. In the illustrated embodiment, the four surfaces connecting the inner surface and the outer surface of the flange 12a are the upper surface 12a1, the lower surface 12a2 facing the upper surface, the first side surface 12a3 connecting the upper surface 12a1 and the lower surface 12a2, and the second side surface 12a4 facing the first side surface 12a3. The four surfaces connecting the inner surface and the outer surface of the flange 12b are the upper surface 12b1, the lower surface 12b2 facing the upper surface, the first side surface 12b3 connecting the upper surface 12b1 and the lower surface 12b2, and the second side surface 12b4 facing the first side surface 12b3. The eight corners of the flange 12a and the flange 12b may have rounded corners. The shapes of the flange 12a and the flange 12b are not limited to a rectangular parallelepiped shape, and the flange 12a and the flange 12b can be formed in various shapes.

[0029] A recess may be provided on at least one surface of the outer surface defining the flange 12a. Similarly, a recess may be provided on at least one surface of the outer surface defining the flange 12b. In the illustrated embodiment, a recess 13a is formed on the upper surface 12a1 of the flange 12a, and a recess 13b is formed on the upper surface 12b1 of the flange 12b. The recess 13a may be formed on a surface other than the upper surface 12a1 of the flange 12a. The recess 13b may be formed on a surface other than the upper surface 12b1 of the flange 12b.

[0030] The core 10 is made of a magnetic material or a non-magnetic material. As the magnetic material for the core 10, for example, ferrite and soft magnetic alloy materials can be used. As the non-magnetic material for the core 10, alumina or glass can be used. The magnetic material for the core 10 may be various crystalline or amorphous alloy magnetic materials, or a material combining a crystalline material and an amorphous material. The crystalline alloy magnetic material that can be used as the magnetic material for the core 10 is, for example, a crystalline alloy material mainly composed of Fe and containing one or more elements selected from the group consisting of Si, Al, Cr, Ni, Ti, and Zr. The amorphous alloy magnetic material that can be used as the magnetic material for the core 10 is, for example, an amorphous alloy material containing either B or C in addition to any one of Si, Al, Cr, Ni, Ti, and Zr. As the magnetic material for the core 10, pure iron composed of Fe and inevitable impurities can be used. As the magnetic material for the core 10, a material combining pure iron composed of Fe and inevitable impurities with various crystalline or amorphous alloy magnetic materials can also be used. The material of the core 10 is not limited to those explicitly stated in this specification, and any material known as the core material can be used.

[0031] A winding 25 is wound around the bobbin 11. The winding 25 has a winding portion 26, a joint portion 28a formed at one end of the winding portion 26, and a joint portion 28b formed at the other end of the winding portion 26. The winding portion 26 is wound around the surface of the bobbin 11 in a plurality of turns. The winding 25 is formed by covering the periphery of a conductor made of a metal material with excellent conductivity with an insulating coating. As the metal material for the winding 25, for example, one or more metals among Cu (copper), Al (aluminum), Ni (nickel), or Ag (silver), or an alloy containing any of these metals can be used. The diameter of the winding 25 may be 0.05 mm or less, 0.03 mm or less, or 0.02 mm or less. Thus, in order to realize the small coil component 1, a thin wire with a diameter of 0.05 mm or less can be used as the winding 25. A flat joint portion 28a is formed at one end of the winding 25, and a flat joint portion 28b is formed at the other end of the winding 25.

[0032] In the illustrated embodiment, an external electrode 21 is provided on the surface of the flange 12a, and an external electrode 22 is provided on the surface of the flange 12b. The coil component 1 may include more than two external electrodes. For example, when the coil component 1 is a magnetically coupled coil component, the coil component 1 can include four or more external electrodes. The external electrodes 21 and 22 may be provided on only one of the flanges 12a and 12b. For example, both the external electrodes 21 and 22 may be provided on the flange 12a. When both the external electrodes 21 and 22 are provided on the flange 12a, the coil component 1 is mounted on the mounting substrate 2a in a posture where the flange 12a faces the mounting substrate 2a. In this case, the coil component 1 is mounted in a vertical posture where the axis Ax of the bobbin 11 is orthogonal to the mounting substrate 2a.

[0033] The external electrode 21 has a metal layer 21a and an electrode layer 21b. The metal layer 21a is provided on the surface 13a1 of the recess 13a formed in the flange 12a. The electrode layer 21b is provided on the surface of the flange 12a so as to cover the joint portion 28a between the metal layer 21a and the winding 25. The external electrode 22 has a metal layer 22a and an electrode layer 22b. The metal layer 22a is provided on the surface 13b1 of the recess 13b formed in the flange 12b. The electrode layer 22b is provided on the surface of the flange 12b so as to cover the joint portion 28b between the metal layer 22a and the winding 25.

[0034] As the materials of the metal layers 21a and 22a and the electrode layers 21b and 22b, for example, metal materials such as Cu and Ag or alloys of these metal materials can be used. The metal layers 21a and 22a and the electrode layers 21b and 22b may be formed by drying a paste-like conductive material containing a metal material and sintering the dried conductive material. A plating layer may be formed on each surface of the electrode layers 21b and 22b. This plating layer may be configured in a two-layer structure including a nickel plating layer and a tin plating layer.

[0035] The winding 25 is joined to the external electrode 21 at the joint 28a and to the external electrode 22 at the joint 28b. That is, the winding 25 is electrically connected to the external electrode 21 at the joint 28a at one end thereof, and is electrically connected to the external electrode 22 at the joint 28b at the other end thereof.

[0036] The exterior portion 40 is provided between the flange 12a and the flange 12b so as to cover at least a part of the winding portion 26 of the winding 25. The exterior portion 40 may be formed only in a part of the space between the flange 12a and the flange 12b. For example, the exterior portion 40 may be filled only in a region on the positive side of the axis Ax in the T-axis direction in the space between the flange 12a and the flange 12b.

[0037] As the material of the exterior portion 40, various insulating materials can be used. For example, as the material of the exterior portion 40, a resin or a resin containing a filler can be used. As the filler, a magnetic material or a non-magnetic material can be used. By using ferrite powder, metal magnetic particles, alumina particles, or silica particles as the filler, the coefficient of linear expansion of the exterior portion 40 can be lowered and the mechanical strength can be increased.

[0038] Subsequently, with reference to FIGS. 2 to 7, a method for manufacturing the coil component 1 according to an embodiment of the present invention will be described. FIG. 2 is a flowchart showing an example of the method for manufacturing the coil component 1. As shown in FIG. 2, in one embodiment, the coil component 1 is manufactured through steps S11 to S18. FIGS. 3a to 3f and FIGS. 4a to 4f are diagrams for explaining the steps included in the method for manufacturing the coil component 1. FIGS. 3a to 3f show the core 10 as viewed from the direction of the L axis, and FIGS. 4a to 4f show views of the core 10 shown in FIGS. 3a to 3f as viewed from the direction of the T axis.

[0039] First, in step S11, the core 10 is prepared. As described above, the core 10 has a bobbin 11 and flanges 12a and 12b. The core 10 is manufactured, for example, by mixing the above-described magnetic or non-magnetic material powder with a lubricant, filling the mixed material into the cavity of a molding die, press-molding it to produce a compacted powder body, and sintering this compacted powder body. The sintering temperature is adjusted, for example, in the range of 600°C to 1000°C according to the material of the compacted powder body. Also, the core 10 can be manufactured by mixing the above-described magnetic or non-magnetic material powder with a resin, glass, or insulating oxide (for example, Ni-Zn ferrite or silica), molding this mixed material, and curing or sintering it. The manufacturing method of the core 10 is not limited to those explicitly described in this specification. The core 10 can be manufactured using any known method.

[0040] Next, in step S12, as shown in FIGS. 3a and 4a, a metal layer 21a is formed on the surface 13a1 of the recess 13a formed in the flange 12a, and a metal layer 22a is formed on the surface 13b1 of the recess 13b formed in the flange 12b. The metal layer 21a is formed by applying a paste-like conductive material containing a metal material (for example, silver or copper) to the surface 13a1 of the recess 13a of the flange 12a and drying and sintering this applied conductive material. Similarly, the metal layer 22a is formed by applying a paste-like conductive material containing a metal material (for example, silver or copper) to the surface 13b1 of the recess 13b of the flange 12b and drying and sintering this applied conductive material. The metal layers 21a and 22a may be formed by a sputtering method or a vapor deposition method. The formation method of the metal layers 21a and 22a is not limited to the methods explicitly described in this specification. The metal layers 21a and 22a can be formed using any known method. A plating layer may be formed on each surface of the metal layers 21a and 22a. This plating layer may be configured in a two-layer structure composed of a nickel plating layer and a tin plating layer.

[0041] Next, in step S13, as shown in FIGS. 3b and 4b, the winding 25 is wound around the surface 11a of the bobbin 11 of the core 10. As shown in the figure, the wound portion 26 of the winding 25 is wound around the bobbin 11. The winding of the winding 25 around the core 10 is performed, for example, using a known spindle type winding machine. The spindle type winding machine includes a spindle motor for rotating the core 10 and a nozzle for supplying the winding 25. The core 10 is pivotally supported by the spindle type winding machine so as to be rotatable around its central axis by the spindle motor. When the core 10 rotates by the driving force from the spindle motor, the winding 25 supplied from the nozzle is wound around the bobbin 11. The winding of the winding 25 around the core 10 may be performed using a flyer type winding machine. The winding of the winding 25 around the core 10 can be performed using any known winding machine.

[0042] One end portion 27a at one end of the winding 25 is drawn toward the flange 12a and placed on the metal layer 21a provided on the flange 12a. The end portion 27a is placed on the metal layer 21a so as to be located outside the wound portion 26 in the radial direction centered on the axis Ax. The other end portion 27b at the other end of the winding 25 is drawn toward the flange 12b and placed on the metal layer 22a provided on the flange 12b. The end portion 27b is placed on the metal layer 22a so as to be located outside the wound portion 26 in the radial direction centered on the axis Ax. Tension directed radially outward centered on the axis Ax may be applied to the end portions 27a and 27b from the tension control mechanism of the winding machine. By applying tension directed radially outward to the end portions 27a and 27b until the end portions 27a and 27b are joined to the metal layers 21a and 22a (joining will be described later), loosening of the wound portion 26 wound around the bobbin 11 can be prevented. The end portions 27a and 27b may be temporarily fixed to the metal layers 21a and 22a until they are joined to the metal layers 21a and 22a.

[0043] Next, in step S14, as shown in FIGS. 3c and 4c, the first jigs J1a, J1b and the second jigs J2a, J2b are arranged at predetermined positions. The first jigs J1a, J1b are installed at the target positions on the surfaces of the metal layers 21a, 22a respectively. The first jigs J1a, J1b may generally have a rectangular parallelepiped shape. As the material of the first jigs J1a, J1b, a material with excellent thermal conductivity including tungsten, molybdenum, etc. can be used. The first jigs J1a, J1b are gripped by a support arm (not shown) configured to be movable in three-dimensional directions (W-axis direction, L-axis direction, T-axis direction), and may be transported to the target positions on the metal layers 21a, 22a by this support arm.

[0044] The target position where the first jig J1a is arranged can be any position on the metal layer 21a. The first jig J1a may be arranged between the axis Ax and the first side surface 12a3 of the flange 12a in the perspective view of the core 10 viewed from the T-axis direction. In the embodiment shown in FIG. 4c, the first jig J1a is arranged between the axis Ax and the surface 11a of the shaft core 11 in the perspective view of the core 10 viewed from the T-axis direction. In one embodiment, the target position where the first jig J1a is arranged is a position overlapping the surface 11a of the shaft core 11 in the W-axis direction in the perspective view viewed from the T-axis. In one embodiment, the target position where the first jig J1a is arranged is a position where the radially inner surface of the first jig J1a overlaps the radially inner side of the metal layer 21a in the radial direction centered on the axis Ax.

[0045] The target position where the first jig J1b is arranged can be any position on the metal layer 22a. The first jig J1b may be arranged between the axis Ax and the second side surface 12b4 of the flange 12b in the perspective view of the core 10 viewed from the T-axis direction. In the embodiment shown in FIG. 4c, the first jig J1a is arranged between the axis Ax and the surface 11a of the shaft core 11 in the perspective view of the core 10 viewed from the T-axis direction. The first jig J1b may be arranged at a position symmetric to the first jig J1a with respect to the center of the core 10 when viewed from the T-axis direction.

[0046] Referring further to FIG. 5, the arrangement of the first jig J1b will be described. As shown in FIG. 5, the first jig J1b may be pushed in from the surface 22a1 of the metal layer 22a toward the inside of the flange 12b (the positive direction in the T-axis direction). That is, the first jig J1b may be arranged such that its lower end bites into the inside of the metal layer 22a. Similarly, the first jig J1a may also be pushed in from the surface 21a1 of the metal layer 21a toward the inside of the flange 12a (the positive direction in the T-axis direction). By biting the first jigs J1a and J1b into the inside of the metals 21a and 22a, the first jigs J1a and J1b can be fixed at the target positions of the metal layers 21a and 22a. Thereby, even when a force in the direction along the surfaces of the metal layers 21a and 22a acts on the first jigs J1a and J1b during the manufacturing process of the coil component 1, the first jigs J1a and J1b can be held at the target positions. When deforming the end portions 27a and 27b of the winding 25 by the pressure from the second jigs J2a and J2b as described later, stress acts on the first jigs J1a and J1b from the end portions 27a and 27b. By biting the first jigs J1a and J1b into the inside of the metals 21a and 22a at the target positions, even when stress acts on the first jigs J1a and J1b from the end portions 27a and 27b, the first jigs J1a and J1b can be held at the target positions.

[0047] The second jigs J2a and J2b may generally have a rectangular parallelepiped shape. The second jigs J2a and J2b may be, for example, pulse heaters that generate heat by the supplied current. The second jigs J2a and J2b may be provided with heater tips at their lower ends. In this case, the second jigs J2a and J2b are in contact with the end portions 27a and 27b at the heater tips. The heater tips may be made of a material having excellent thermal conductivity including tungsten, molybdenum, etc.

[0048] The second jig J2a may be disposed at a position facing the first jig J1a in the radial direction centered on the axis Ax. The second jig J2a is disposed outside the first jig J1a in the radial direction centered on the axis Ax. The first jig J1a has an outer surface J1a1 facing the outside in the radial direction centered on the axis Ax. The second jig J2a is disposed so as to face the outer surface J1a1 of the first jig J1a.

[0049] The second jig J2b may be disposed at a position facing the first jig J1b in the radial direction centered on the axis Ax. The second jig J2b is disposed outside the first jig J1b in the radial direction centered on the axis Ax. The first jig J1b has an outer surface J1b1 facing the outside in the radial direction centered on the axis Ax. The second jig J2b is disposed so as to face the outer surface J1b1 of the first jig J1b. The second jig J2b may be disposed at a position symmetric to the second jig J2a with respect to the center of the core 10 when viewed from the T-axis direction.

[0050] The second jigs J2a and J2b may be gripped by a support arm (not shown) configured to be movable in three-dimensional directions (W-axis direction, L-axis direction, T-axis direction) and transported to the above-described positions by this support arm. The arm for transporting the second jigs J2a and J2b may be different from the arm for transporting the first jigs J1a and J1b.

[0051] Next, in step S15, as shown in FIGS. 3D and 4D, by moving the second jigs J2a and J2b downward, the second jigs J2a and J2b are pressed against the end portions 27a and 27b of the winding 25. Due to the downward pressure from the second jigs J2a and J2b, the end portions 27a and 27b of the winding 25 are deformed into flat joint portions 28a and 28b. Further, the second jigs J2a and J2b are heated to heat the joint portions 28a and 28b. Due to the heat transmitted from the second jigs J2a and J2b, the joint portion 28a is metallically bonded to the upper surface of the metal layer 21a on its lower surface, and the joint portion 28b is metallically bonded to the upper surface of the metal layer 22a on its lower surface. In this way, the joint portions 28a and 28b are joined to the metal layers 21a and 22a. By alloying the metal atoms contained in the joint portions 28a and 28b and the metal atoms contained in the metal layers 21a and 22a at the interfaces between the joint portions 28a and 28b and the metal layers 21a and 22a due to the heat transmitted from the second jigs J2a and J2b, the joint portions 28a and 28b may be joined to the metal layers 21a and 22a.

[0052] Referring further to FIGS. 6 and 7, the deformation of the end portion 27b due to the pressure from the second jig J2b will be described. The following description regarding the deformation of the end portion 27b also applies to the deformation of the end portion 27a. However, for the sake of brevity of explanation, the deformation of the end portion 27b will be described below. As shown in FIG. 6(a), when pressure is applied downward (in the positive direction of the T-axis) from the second jig J2b to the end portion 27b disposed on the metal layer 22a, the end portion 27b deforms due to the downward pressure from the second jig J2b. Further, since the end portion 27b is heated by the second jig J2b, it becomes more flexible while receiving the downward pressure from the second jig J2b. Also, due to the heat from the second jig J2b, at least a part of at least one of the end portion 27b and the metal layer 22a melts. Since how the end portion 27b deforms due to the pressurization and heating from the second jig J2b can vary depending on various factors, it is difficult to control the position and shape of the end portion 27b after deformation. For example, depending on the shape and posture of the end portion 27b, the direction of pressure transmission from the second jig J2b to the end portion 27b changes. Therefore, simply pressing downward by the second jig J2b may cause the position of the end portion 27b after deformation to deviate from the target position. Also, depending on the contact mode between the second jig J2b and the end portion 27b, heat is transmitted to the end portion 27b in different modes. For this reason, depending on the contact mode between the second jig J2b and the end portion 27b, some parts of the end portion 27b may be more likely to melt than other parts. For this reason, simply pressing and heating the second jig J2b against the end portion 27b from above it may cause the end portion 27b to melt unevenly, resulting in the possibility that the end portion 27b after deformation is joined to the metal layer 22a at a position different from the target position. Thus, it is difficult to control the shape and position of the end portion 27b after deformation because the pressure and heat transmitted from the second jig J2b to the end portion 27b tend to be non-uniform.

[0053] In one embodiment of the present invention, a first jig J1b is disposed at a target position in the metal layer 22a, and the second jig J2b moves toward the metal layer 22a along the outer surface J1b1 of the first jig J1b, thereby applying a downward load to the end portion 27b of the winding 25. The end portion 27b of the winding 25 is deformed by the load from the second jig J2b, and this deformation is restricted by the first jig J1b disposed at the target position of the metal layer 22a. The load applied from the second jig J2b to the end portion 27b of the winding 25 is set so that the end portion 27b of the winding 25 can be deformed until it contacts the first jig J1b. For this reason, the end portion 27b of the winding 25 is deformed by the load from the second jig J2b and becomes a flat joint portion 28b that contacts the first jig J1b. In this way, the joint portion 28b is disposed at a position based on the target position where the first jig J1b is disposed. Then, the joint portion 28b is joined to the metal layer 22a at the target position by heating from the second jig J2b. Therefore, according to one embodiment of the present invention, the joint portion 28b of the winding 25 can be joined to the metal layer 22a at the target position defined by the first jig J1b.

[0054] The first jig J1b is configured such that the distance H (see FIG. 5) from the upper end of the outer surface J1b1 to the metal layer 22a is larger than the diameter d1 of the winding 25. Thereby, the first jig J1b can receive the end portion 27b that is deformed by the load from the second jig J2b.

[0055] In the embodiment shown in FIG. 4c, the first jig J1b is disposed between the end portion 27b of the winding 25 and the axis Ax of the bobbin 11. Therefore, the movement of the end portion 27b of the winding 25 in the direction approaching the axis Ax is restricted by the first jig J1b. When the end portion 27b of the winding 25 is joined to the metal layer 22a, if the end portion 27b moves toward the axis Ax, the wound portion 26 wound around the bobbin 11 will become loose. By disposing the first jig J1b between the end portion 27b placed on the metal layer 22a and the axis Ax when joining the end portion 27b of the winding 25, the end portion 27b of the winding 25 deforms in a direction away from the first jig J1b while contacting the first jig J1b (in the radial direction, a direction away from the axis Ax). As a result, the joint portion 28b is arranged at a shifted position in a direction away from the axis Ax in the radial direction compared to the position where the end portion 27b is placed. As a result, the movement of the end portion 27b in the direction approaching the axis Ax can be restricted, and thus the loosening of the wound portion 26 during joining can be suppressed.

[0056] As described above, the end portion 27b of the winding 25 deforms due to the load received from the second jig J2b and becomes a joint portion 28b having a flat shape. As shown in FIG. 7, the thickness d2 of the joint portion 28b is smaller than the diameter d1 of the end portion before deformation. The thickness d2 of the joint portion can be adjusted by setting the load applied from the second jig J2b to the end portion 27b. In one embodiment, the load applied from the second jig J2b to the end portion 27b is set such that the thickness d2 of the joint portion is 1 / 10 or more, 1 / 5 or more, 1 / 4 or more, 1 / 3 or more, or 1 / 2 or more of the diameter d1 of the end portion 27b before deformation. By setting the ratio of the thickness d2 of the joint portion to the diameter d1 of the end portion 27b to a predetermined value or more, breakage of the joint portion 28b due to excessive deformation can be prevented.

[0057] In one embodiment of the present invention, by adjusting the load applied to the end portion 27b by the second jig J2a, as shown in FIG. 6(b), the surface 28b1 of the joint portion 28b is retracted from the upper surface 12a1 of the flange 12b (a position in the positive direction of the T-axis direction from the upper surface 12a1), the end portion 27b can be deformed. Thereby, since mechanical stress from the outside is less likely to act on the joint portion 28b, the joint portion between the joint portion 28b and the metal layer 22a is less likely to break.

[0058] While heating the end portion 27b by the second jig J2b, the first jig J1b may be kept at a lower temperature than the second jig J2b. By keeping the first jig J1b at a lower temperature than the second jig J2b, heat can be conducted from the end portion 27b heated by the second jig J2b to the first jig J1b in contact with this end portion 27b, and the heat conducted from this end portion 27b can be dissipated in the first jig J1b. An uneven pattern may be formed on a part of the surface of the first jig J1b to improve the heat dissipation efficiency from the first jig J1b. The first jig J1b may be provided with fins for heat dissipation. By conducting heat from the end portion 27b to the first jig J1b, the conduction of heat from the end portion 27b to the winding portion 26 can be suppressed. If excessive heat is transferred from the heated end portion 27b to the winding portion 26, the heat may soften the conductor or the insulating coating of the winding portion 26, and the winding portion 26 may become loose. Also, if the insulating coating deteriorates due to heat, a short circuit may occur between the conductors of the winding portion 26. Therefore, by suppressing the conduction of heat from the end portion 27b to the winding portion 26 by the first jig J1b kept at a low temperature, the temperature rise of the winding portion 26 can be suppressed, and problems such as loosening of the winding portion 26 and short circuits between conductors can be suppressed. Since the first jig J1b is in contact with the end portion 27b only at the end in the direction parallel to the surface of the metal layer 22a of the end portion 27b, even if the first jig J1b is kept at a low temperature, the joint portion between the end portion 27b (or the joint portion 28b obtained by deforming the end portion 27b) and the metal layer 22a can be sufficiently heated.

[0059] In one embodiment of the present invention, by pressing the end portion 27b downward with the second jig J2b, the joint portion 28b obtained by deforming the end portion 27b can be made to bite into the metal layer 22a. In one embodiment, the joint portion 28b may bite into the metal layer 22a such that its surface 28b1 is flush with the surface of the metal layer 22a. Thereby, the joint portion 28b can be more firmly joined to the metal layer 22a. In this case, the surface including 28b1 of the surface of the joint portion 28b and the surface 22a1 of the metal layer 22a can be used as the mounting surface of the coil component 1.

[0060] The description regarding the pressurization and heating of the end portion 27b by the second jig J2b also applies to the pressurization and heating of the end portion 27a by the second jig J2a.

[0061] When the joining of the joint portion 28a and the metal layer 21a and the joining of the joint portion 28b and the metal layer 22a are completed, next, in step S16, the excess portion of the winding 25 is cut. Specifically, the portion of one end of the winding 25 that protrudes from the metal layer 21a and the portion of the winding 25 that protrudes from the metal layer 22a are cut. Thereby, as shown in FIGS. 3e and 4e, in a plan view (in the direction viewed from the T axis), the joint portion 28a at one end of the winding 25 is disposed within the metal layer 21a, and the joint portion 28b at the other end of the winding 25 is disposed within the metal layer 22a. Before cutting the winding 25, the first jigs J1a, J1b and the second jigs J2a, J2b may be retracted. The cutting of the winding 25 may be performed while pressurizing and heating the end portions 27a, 27b with the second jig J2b. By cutting the winding 25 while pressurizing the end portions 27a, 27b with the second jig J2b, at the time of cutting the winding 25, the end portions 27a, 27b are pressed against and fixed to the flanges 12a, 12b by the pressure from the second jig J2b, so that the load applied to the end portions 27a, 27b during cutting can be suppressed. Further, by cutting the winding 25 while heating the end portions 27a, 27b with the second jig J2b, the cutting portion of the winding 25 can be made flexible, whereby the load applied to the winding 25 during cutting can be suppressed.

[0062] Next, in step S17, as shown in FIGS. 3f and 4f, a conductive electrode layer 21b may be formed to cover the metal layer 21a and the joint portion 28a, and a conductive electrode layer 22b may be formed to cover the metal layer 22a and the joint portion 28b. The electrode layers 21b and 22b may be formed by applying a paste-like conductive material containing a metal material with excellent conductivity such as silver or copper so as to cover the metal layers 21a and 22a and the joint portions 28a and 28b respectively, drying the applied conductive material, and further covering the surface of the dried conductive material with a plating layer. This plating layer may have a two-layer structure of a nickel plating layer and a tin plating layer. The external electrode 21 is constituted by the electrode layer 21b and the metal layer 21a thus formed, and the external electrode 22 is constituted by the electrode layer 22b and the metal layer 22a.

[0063] Next, in step S18, an exterior portion is formed in the region between the flange 12a and the flange 12b so as to cover at least a part of the winding portion 26. The exterior portion 40 is formed, for example, by applying the above-described resin material between the flange 12a and the flange 12b by roller transfer, pre-curing the applied resin, shaping it, and further curing the shaped resin.

[0064] The coil component 1 is manufactured as described above. In the coil component 1 manufactured in this way, the joint portions 28a and 28b can be accurately arranged at the target positions defined by the first jigs J1a and J1b. Therefore, according to the above manufacturing method, problems caused by the deviation of the joint position between the winding and the external electrode from the target position are prevented or suppressed. For example, a decrease in joint strength and loosening of the winding portion due to the deviation of the joint position between the winding and the external electrode from the target position are prevented.

[0065] In the above manufacturing method, it is possible to omit a part of the steps, add steps not explicitly described, and / or change the order of the steps. As long as such omissions, additions, and order changes do not deviate from the spirit of the present invention, the processing procedures thus modified are included in the scope of the present invention. For example, the coil component 1 may not be provided with the electrode layers 21b and 22b. When the coil component 1 is not provided with the electrode layers 21b and 22b, the metal layer 21a alone becomes the external electrode 21, and the metal layer 22a alone becomes the external electrode 22. In this case, step S17 can be omitted. Also, the step of step S18 for forming the exterior part 40 can be executed before the step of step S17 for forming the electrode layers 21b and 22b.

[0066] Next, with reference to FIGS. 8 to 10, a manufacturing method of the coil component 1 according to another embodiment will be described. In the embodiment shown in FIGS. 8 to 10, in the bonding step, in addition to the first jigs J1a, J1b and the second jigs J2a, J2b, the third jigs J3a, J3b are used, which is different from the above-described embodiment. FIGS. 8 and 10 show views of the core 10 in the bonding step as seen from the direction of the L axis, and FIG. 9 shows a view of the core 10 in the bonding step as seen from the direction of the T axis.

[0067] In the embodiment shown in these figures, in the jig installation step in step S14, in addition to the first jigs J1a, J1b and the second jigs J2a, J2b, the third jigs J3a, J3b are installed on the surfaces of the metal layers 21a and 22a. As shown in FIG. 9, the third jig J3a is configured and arranged to protrude outward in the radial direction centered on the axis Ax rather than the outer surface J1a1 of the first jig J1a. Similarly, the third jig J3b is configured and arranged to protrude outward in the radial direction centered on the axis Ax rather than the outer surface J1b1 of the first jig J1b.

[0068] As shown in FIG. 10, the third jig J3b is provided at a position that interferes with the trajectory of the second jig J2b that moves along the T-axis direction. Similarly, the third jig J3a is provided at a position that interferes with the trajectory of the second jig J2a that moves along the T-axis direction. For this reason, the downward movement of the second jigs J2a and J2b is restricted by the third jigs J3a and J3b. Thereby, the thickness d2 of the joint portions 28a and 28b obtained by deforming the end portions 27a and 27b can be made equal to the dimension in the T-axis direction of the third jigs J3a and J3b. For this reason, the amount of deformation of the end portions 27a and 27b can be suppressed. When the amount of deformation of the end portions 27a and 27b increases, the strength of the joint portions 28a and 28b decreases due to metal fatigue. By suppressing the amount of deformation of the end portions 27a and 27b by the third jigs J3a and J3b, a decrease in the strength of the joint portions 28a and 28b can be suppressed.

[0069] When the diameter of the conductor of the winding 25 becomes thin, the thickness d2 of the joint portions 28a and 28b fluctuates greatly due to a slight difference in the setting of the load to be applied by the second jigs J2a and J2b. Therefore, it becomes difficult to control the thickness d2 of the joint portions 28a and 28b only by the setting of the second jigs J2a and J2b. By restricting the downward movement of the second jigs J2a and J2b by the third jigs J3a and J3b, the thickness d2 of the joint portions 28a and 28b can be made equal to the dimension in the T-axis direction of the third jigs J3a and J3b. For this reason, by using the third jigs J3a and J3b, even when the diameter of the conductor of the winding 25 becomes thin (for example, even if it is about 0.02 mm to 0.05 mm), the thickness d2 of the joint portions 28a and 28b can be accurately controlled.

[0070] When the thickness d2 of the joint portions 28a and 28b becomes thin, the difference in thickness between the portion of the winding 25 that has not been deformed by the second jigs J2a and J2b and the joint portions 28a and 28b becomes prominent. Since stress tends to concentrate at the portion where the thickness of the winding 25 changes significantly, it can cause the breakage of the winding 25. By suppressing the amount of deformation of the end portions 27a and 27b by the third jigs J3a and J3b, the difference in thickness between the portion of the winding 25 that has not been deformed by the second jigs J2a and J2b and the joint portions 28a and 28b can be accurately controlled. Therefore, it is possible to prevent the difference in thickness between the portion of the winding 25 that has not been deformed by the second jigs J2a and J2b and the joint portions 28a and 28b from unintentionally becoming large, and thereby suppress the breakage of the winding 25.

[0071] According to the above embodiment, the deformation of the end portions 27a and 27b of the winding 25 due to heating and pressurization from the second jigs J2a and J2b is restricted by the first jigs J1a and J1b disposed at the target positions on the surfaces of the metal layers 21a and 22a. Therefore, the joint portions 28a and 28b obtained by deforming the end portions 27a and 27b of the winding deformed by the second jigs J2a and J2b are disposed at the target positions defined by the first jigs J1a and J1b on the surfaces of the metal layers 21a and 22a. Thus, the winding 25 is joined to the metal layers 21a and 22a at the target positions defined by the first jigs J1a and J1b. Therefore, according to the above embodiment, the winding 25 can be joined to the metal layers 21a and 22a without deviating from the target positions defined by the first jigs J1a and J1b.

[0072] The dimensions, materials, and arrangements of the components described in this specification are not limited to those explicitly described in the embodiments, and each of these components can be deformed to have any dimensions, materials, and arrangements that can be included in the scope of the present invention. Also, components not explicitly described in this specification can be added to the described embodiments, or some of the components described in each embodiment can be omitted.

[0073] Components not explicitly described in this specification can be added to each of the above-described embodiments, or some of the components described in each embodiment can be omitted.

[0074] Expressions such as "first", "second", "third", etc. in this specification and the like are attached to identify components and do not necessarily limit the number, order, or content thereof. Also, numbers for identifying components are used contextually, and a number used in one context does not necessarily indicate the same configuration in another context. Further, it does not prevent a component identified by a certain number from also having the functions of a component identified by another number.

Explanation of Reference Signs

[0075] 1 Coil component J1a, J1b First jig J2a, J2b Second jig J3a, J3b Third jig 10 Core 11 Bobbin 12a, 12b Flange 21a, 22a Metal layer 25 Winding 28a, 28b Joint 40 Exterior part

Claims

1. A core preparation step of preparing a core having a bobbin and a flange connected to one end of the bobbin, A metal layer forming step of forming a conductive metal layer on the surface of the flange, A jig arrangement step of arranging a first jig at a target position on the surface of the metal layer, A joining step of deforming an end portion of a winding disposed on the surface of the metal layer by pressing and heating with a second jig so that the end portion is in contact with the first jig, and joining the deformed end portion to the metal layer, A method for manufacturing a coil component comprising:

2. In the jig arrangement step, the first jig is pushed into the metal layer from the surface at the target position, The method for manufacturing a coil component according to Claim 1.

3. In the joining step, the end portion is disposed at a position on the surface of the metal layer that is distal from the axis of the bobbin and farther from the first jig, The method for manufacturing a coil component according to Claim 1 or 2.

4. In the joining step, the first jig is kept at a lower temperature than the second jig, The method for manufacturing a coil component according to any one of Claims 1 to 3.

5. In the joining step, the second jig applies pressure to the end portion by moving toward the metal layer, The method for manufacturing a coil component according to any one of Claims 1 to 4.

6. In the jig arrangement step, a third jig is arranged at a position on the surface of the metal layer that interferes with the trajectory of the second jig, In the joining step, the second jig moves toward the metal layer to a position in contact with the third jig, The method for manufacturing a coil component according to Claim 5.

7. The diameter of the winding is 0.02 mm or less, The method for manufacturing a coil component according to any one of Claims 1 to 6.

8. In the joining step, the end portion of the winding is deformed into a joining portion in contact with the first jig, The thickness of the joining portion is 1 / 2 or more of the diameter of the winding, The method for manufacturing a coil component according to any one of Claims 1 to 7.

9. The first jig has a first surface orthogonal to the surface of the metal layer, The joining portion is in contact with the first jig on the first surface, The method for manufacturing a coil component according to Claim 8.

10. The distance from the upper end of the first surface to the metal layer is greater than the diameter of the winding, The method for manufacturing a coil component according to Claim 9.

11. Further comprising a step of forming a conductive electrode layer so as to cover the metal layer and the joint portion The method for manufacturing a coil component according to any one of claims 8 to 10.

12. The winding has a winding portion wound around the bobbin Further comprising a step of providing an insulating exterior portion so as to cover at least a part of the winding portion The method for manufacturing a coil component according to any one of claims 1 to 11.

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