COIL COMPONENT

Abstract

Coil component (40; 40a) having the following features: a wire (61, 62) having a substantially coiled shape, wherein the wire comprises a central conductor (63, 64) having a linear shape and an insulating coating layer (65, 66) covering a circumferential surface of the central conductor; and a terminal electrode (71-74) having a connecting part (79) which is electrically connected to the central conductor at an end section of the wire;wherein the connecting part of the terminal electrode has a receiving part (80) which receives the end section of the wire, and a welding part (82) which extends from the receiving part over a folding part (81) to face the receiving part, wherein the wire is arranged between the receiving part and the welding part and the central conductor of the wire is welded to the welding part in a section from which the insulating coating layer has been removed, and wherein a distal end section (67) of the wire (61, 62) projects from a space between the receiving part and the welding part with respect to the section from which the insulating coating layer has been removed, wherein the insulating coating layer remains at least on a region of the distal end section which is opposite a region in contact with the receiving part.

Description

The present disclosure relates to a coil component including a substantially coiled wire, and more particularly to the structure of a connection between the wire and a terminal electrode.An example of a technique of interest to the present disclosure is described in JP 4 184 394 B2. FIGS. 8, 9 and 10 cited from JP 4 184 394 B2 correspond to FIGS. 2, 4 and 5 in JP 4 184 394 B2. FIGS. 8 to 10 show the following components: a flange 1 constituting a part of a core included in a coil component; a terminal electrode 2 positioned on the flange 1; and an end portion of a wire 3 connected to the terminal electrode 2.As illustrated in FIGS. 8 and 10, the wire 3 includes a center conductor 4 having a substantially linear shape and an insulation coating layer 5 covering the circumferential surface of the center conductor 4. The terminal electrode 2 has a base 7 and a receiving part 9. The base 7 is positioned on the same side as an outer end face 6 of the flange 1. the receiving part 9 extends from the base 7 via a bending part 8 and receives an end portion of the wire 3. The terminal electrode 2 further includes a welding part 11 and a holding part 13. the welding part 11 extends from the receiving part 9 via a first folding-back part 10 and is to be welded to the center conductor 4 of the wire 3. The holding part 13 extends from the receiving part 9 via a second folding-back part 12 in order to hold and position the wire 3 in its position.The state of the welding part 11 before being subjected to a welding step and the state of the welding part 11 after being subjected to the welding step are illustrated in FIGS. 8, 9, and 10, respectively. A welding ball 14 formed as a result of this welding is illustrated in FIGS. 9 and 10.The welding step is performed as follows. Before the welding step, the welding part 11 and the holding part 13 of the terminal electrode 2 are in their unfolded state with respect to the receiving part and do not face the receiving part 9. FIG. 8 shows a state in which, although the holding part 13 faces the receiving part 9, the welding part 11 is in its unfolded state with respect to the receiving part 9.First, the wire 3 is placed on the receiving part 9 of the terminal electrode 2. In order to temporarily attach the wire 3 in this state, the holding part 13 is folded at the second folding-back part 12 toward the receiving part 9 such that the wire 3 is disposed between the receiving part 9 and the holding part 13.Next, as illustrated in FIG. 8, the insulation coating layer 5 is removed in the portion of the wire 3 that is closer to the distal end of the wire 3 relative to the holding part. At this time, for example, laser beam irradiation is used to remove the insulation coating layer 5. As also clearly shown in FIG. 10, the portion of the insulation coating layer 5 in contact with the receiving member 9 is allowed to remain unexposed.Next, the welding part 11 is folded toward the receiving part 9 at the first folding-back part 10, causing the wire 3 to be disposed between the welding part 11 and the receiving part 9.Next, the center conductor 4 of the wire 3 and the welding part 11 are welded together. Specifically, laser welding is performed. A laser beam is applied to the welding part 11, causing the center conductor 4 of the wire 3 and the welding part 11 to fuse together, thereby welding the center conductor 4 and the welding part 11 together.During the welding step, when the welding part 11 of the terminal electrode 2 and the center conductor 4 of the wire 3 melt and liquify as described above, the resulting surface tension causes the shape of the melted portion to approach the shape of a ball. Consequently, the welding ball 11 is formed as described above. When the welding part 11 of the terminal electrode 2 and the center conductor 4 of the wire 3 melt and liquify, this may cause the molten metal 15 to protrude beyond the receiving part 9 of the terminal electrode 2 and reach the bending part 8 or the base 7, as indicated by the blackened portion in FIG. 11.Excessive welding, for example, welding, which causes the molten metal 15 to protrude beyond the receiving part 9 of the terminal electrode 2 and reach the bending part or the base 7 may adversely affect the terminal electrode 2. For example, this may cause undesired melting or deformation to occur in a portion of the bent part 8 of the terminal electrode 2, which may make it impossible for the terminal electrode 2 to function properly.US 2008 / 0003864 A1 discloses a coil component including a connection part that is not excessively welded to a terminal electrode. The end portion of a lead wire of a common mode filter is laser welded while being held by a holding piece and a surface of the terminal electrode.In JP H03-110 090 A, it relates to securing melting and bonding and stabilizing the bonding strength by irradiating the insulating coating in the bonding part of a metal element with a laser beam and removing the insulating coating, then placing the metal element to be bonded on the bonding part and irradiating the bonding part with the laser beam from above.Accordingly, an object of the present disclosure is to provide a coil component having a structure that can reduce the above-mentioned excessive welding.This object is achieved by the coil component according to claim 1.An embodiment of the present disclosure is directed to a coil component including a wire having a substantially coiled shape and a terminal electrode. The wire includes a center conductor having a linear shape and an insulation coating layer covering the circumferential surface of the center conductor. The terminal electrode has a connection part electrically connected to the center conductor in an end portion of the wire.The connection part of the terminal electrode includes a receiving part that receives the end portion of the wire, and a welding part that extends from the receiving part via a folding-back part to face the receiving part. The wire is disposed between the receiving part and the welding part. The center conductor of the wire is welded to the welded part in a portion from which the insulation coating layer is removed.In the coil component configured as described above, the distal end portion of the wire protrudes from the space between the receiving part and the welding part with respect to the portion from which the insulation coating layer is removed, the insulation coating layer remaining on at least a portion of the distal end portion that is opposite to the portion in contact with the receiving part.Using the above-mentioned characteristic configuration ensures that when the welding part of the terminal electrode and the central conductor of the wire melt and liquify and the resultant liquefied metal is about to pass beyond the receiving part of the terminal electrode, the liquefied metal is repelled by the insulation coating layer protruding from the space between the receiving part and the welding part and covering the distal end portion of the wire.According to another embodiment of the present disclosure, the insulation coating layer remains on the entire periphery of the distal end portion of the wire. This configuration ensures that the liquefied metal is repelled by the insulation coating layer covering the distal end portion of the wire.According to another embodiment of the present disclosure, the insulation coating layer of the wire is present not only in the distal end portion of the wire but also in a portion of the wire that is in contact with the receiving part. The insulation coating layer existing in the portion of the wire that is in contact with the receiving part also serves to reduce excessive welding.The coil component according to another embodiment of the present disclosure may not include a core. However, in the case where the coil component includes a core, the core includes a core part and a flange provided in an end portion of the core part. The wire is wound around the core part in a substantially coiled manner.According to another embodiment of the present disclosure, the flange includes a bottom surface facing a fixing plate when the coil component is fixed to the fixing plate, and the terminal electrode is disposed such that at least a part of the terminal electrode extends along the bottom surface. This configuration enables the coil component to be configured as a surface-mount coil component.According to another embodiment of the present disclosure, the insulation coating layer is made of a material capable of withstanding a temperature applied to the insulation coating layer when the center conductor and the welded part are welded together. This configuration prevents undesirable melting or decomposition of the portion of the insulation coating layer that needs to remain.The coil component according to an exemplary embodiment of the present disclosure has a structure such that the liquefied metal generated when the welding part of each of the terminal electrodes and the center conductor of the wire melt can be repelled by the insulation coating layer covering the distal end portion of the wire. This reduces undesirable deformation or melting that occurs at the terminal electrode due to excessive welding.Other functions, elements, characteristics, and advantages of the present disclosure will become apparent from the following detailed description with reference to the accompanying drawings.Preferred exemplary embodiments of the present invention are explained in more detail below with reference to the attached drawings. The following are shown: FIGS. 1A and 1B are external perspective views of a coil component according to a first embodiment of the present disclosure, wherein FIG. 1A is a view viewed from a relatively higher position above the coil component and FIG. 1B is a view thereof viewed from a relatively lower position below the coil component; FIG. 2 is an external bottom view of the coil component illustrated in FIG. 1 ; FIG. 3 is a bottom view corresponding to FIG. 2 illustrating a state before welding wires to terminal electrodes; FIG. 4 is an enlarged bottom view of the portion near a terminal electrode of the coil component illustrated in FIG. 1 ; FIGS. 5A and 5B are sectional views of the portion illustrated in FIG. 4, in which FIG. 5A is a sectional view taken along a line A-A in FIG. 4, and FIG. 5B is a sectional view taken along a line B-B in FIG. 4 ; FIGS. 6A and 6B are perspective views of a coil component according to a second embodiment of the present disclosure illustrating only a core and terminal electrodes, with illustration of wires included in the coil component omitted, FIG. 6A is a view from a relatively higher position above the coil component, and FIG. 6B is a view from a relatively lower position below the coil component; FIGS. 7A and 7B are external perspective views of a coil component according to a third embodiment of the present disclosure, wherein FIG. 7A is a view from a relatively higher position above the coil component and FIG. 7B is a view from a relatively lower position below the coil component; FIG. 8 is a perspective view of a flange illustrating a part of a core included in the coil component described in JP 4 184 394 B2, a terminal electrode positioned on the flange, and an end portion of a wire connected to the terminal electrode, illustrating a state before welding; FIG. 9 is a perspective view of the portion illustrated in FIG. 8, illustrating the state of the portion after the welding is performed; FIG. 10 is a sectional view of the portion illustrated in FIG. 9 ; and FIG. 11 is an illustration corresponding to FIG. 10 for explaining the problem to be addressed by the present disclosure.A coil component 40 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1A to 5B. More specifically, the coil component 40 illustrated in these figures constitutes a common mode choke coil that is an example of a coil component.The coil component 40 includes a core 42 having a substantially drum-like shape and having a core part 41. The core 42 includes first and second flanges 43 and 44 each provided at an end portion of the core part 41. The core 42 is made of, for example, a magnetic material such as ferrite. Although it can be deduced from FIGS. 1A and 1B that the core part 41 has the shape of a substantially quadrangular prism, alternatively, the core part 41 may have a substantially cylindrical or polygonal prism shape.The flanges 43 and 44 each have an inner end surface 45 and 46 facing the core part 41 and on which both end portions of the core part 41 are positioned, and an outer end surface 47 and 48 facing the inner end surface 45 and 46, respectively. Further, the flanges 43 and 44 each have a bottom surface 49 and 50, respectively, that faces a mounting plate (not shown) when the coil component 40 is mounted on the mounting plate, a top surface 51 and 52, respectively, that faces the bottom surface 49 and 50, respectively, a first side surface 53 and 54, respectively, and a second side surface 55 and 56, respectively, that faces the first side surface 53 and 54, respectively.In the first flange 43, the bottom surface 49, the top surface 51, the first side surface 53, and the second side surface 55 respectively connect the inner end surface 45 to the outer end surface 47. the first side surface 53 and the second side surface 55 extend to connect the bottom surface 49 to the top surface 51.Similarly, in the second flange 44, the bottom surface 50, the top surface 52, the first side surface 54, and the second side surface 56 respectively connect the inner end surface 46 to the outer end surface 48. the first side surface 54 and the second side surface 56 extend to connect the bottom surface 50 to the top surface 52.The first flange 43 has recesses 57 and 58 in the form of cut-outs, which are respectively located in an end section of the first and second side surfaces 53 and 55 close to the bottom surface 49.Likewise, the second flange 44 has depressions 59 and 60 in the form of cut-outs, which are respectively located in an end section of the first and second side surfaces 54 and 56 close to the bottom surface 50.The coil component 40 further includes first and second wires 61 and 62 wound on the core part 41 in a substantially coiled manner. As illustrated in FIGS. 3, 5A, and 5B, the wires 61 and 62 include center conductors 63 and 64, respectively, having a substantially linear shape, and insulation coating layers 65 and 66, respectively, covering the circumferential surfaces of the center conductors 63 and 64. The center conductors 63 and 64 are each formed by, for example, a copper wire. The insulation coating layers 65 and 66 are made of a material capable of withstanding temperatures applied to the insulation coating layers 65 and 66 in a welding step described later, for example, resin, e.g., polyurethane, polyimide, polyesterimide, or polyamideimide.If the coil component 40 is a common mode choke coil, the wires 61 and 62 are wound in the same direction. At this time, the wires 61 and 62 may be wound either in a two-layer manner such that one of the wires is on the inner layer side and the other is on the outer layer side, or in a double-core manner such that the wires are alternately arranged and wound in parallel to each other in the axial direction of the core part 41.The coil component 40 further includes first to fourth terminal electrodes 71 to 74, In the first to fourth terminal electrodes 71 to 74, the first and third terminal electrodes 71 and 73 are attached to the first flange 43 using an adhesive. The second and fourth terminal electrodes 72 and 74 are bonded to the second flange 44 using an adhesive.The first terminal electrode 71 and the fourth terminal electrode 74 have substantially an identical shape, and the second terminal electrode 72 and the third terminal electrode 73 have substantially an identical shape. The first terminal electrode 71 and the third terminal electrode 73 are substantially plane-symmetric, and the second terminal electrode 72 and the fourth terminal electrode 74 are substantially plane-symmetric. Accordingly, any one of the first to fourth terminal electrodes 71 to 74, for example, the first terminal electrode 71, will be described in detail below, and a detailed description of the second, third, and fourth terminal electrodes 72, 73, and 74 will not be provided.The terminal electrode 71 is normally manufactured by, for example, sheet-metal working a single metal sheet made of a copper-based alloy such as phosphor bronze or electrolytic toughness copper. However, the terminal electrode 71 may be formed by another method such as casting.The terminal electrode 71 includes a base 75 and a fixing part 77. the base 75 extends along the outer end surface 47 of the flange 43. the fixing part 77 extends from the base 75 along the bottom surface 49 of the flange 43 via a first bending part 76 covering the edge portion where the outer end surface 47 and the bottom surface 49 of the flange 43 meet, that is, the base 75 is positioned on the same side as the outer end surface 47 of the flange 43, and the fixing part 77 extends over the first bending part 76 to be positioned on the same side as the bottom surface 49 of the flange 43.Further, the terminal electrode 71 has a connection part 79 extending from the base 75 via a second bending part 78. The connection part 79 includes a receiving part 80 and a welding part 82. the receiving part 80 receives an end portion of the wire 61. The welding part 82 extends from the receiving part 80 via a folding-back part 81 to overlap the receiving part 80 and is welded to an end portion of the wire 61. The connecting part 79 is positioned in the recess 57 provided in the first flange 43.As described above, the connecting part 79 has both the function of receiving and positioning the wire 61 and the function of welding the wire 61.Reference numerals 75, 76, 77, 78, 79, 80, 81, and 82, which are used to denote the base, the first bending part, the fixing part, the second bending part, the connecting part, the receiving part, the folding-back part, and the welding part of the first terminal electrode 71, respectively, are also used to denote the corresponding first bending part, fixing part, second bending part, connecting part, receiving part, folding-back part, and welding part of each of the second, third, and fourth terminal electrodes 72, 73, and 74, respectively.One end of the first wire 61 is connected to the first terminal electrode 71 and the other end of the first wire 61 is connected to the second terminal electrode 72. One end of the second wire 62 is connected to the third terminal electrode 73, and the other end of the second wire 62 is connected to the fourth terminal electrode 74. The process of connecting the first wire 61 to the first terminal electrode 71 will be described below as a representative example.Before connecting the wire 61, the connecting part 79 has the welding part 82 of the terminal electrode 71 in its unfolded state with respect to the receiving part 80 as illustrated in FIG. 3. In this state, the end portion of the wire 61 is positioned at the receiving part 80 of the terminal electrode 71.Next, the wire 61 is temporarily attached to the receiving part 80. For example, the insulation coating layer 65 of the wire 61 is heated to soften, followed by applying a charge to the resulting insulation coating layer 65, bringing the wire 61 into close contact with the receiving part 80, thereby temporarily attaching the wire 61 to the receiving part 80. At this time, the wire 61 is positioned such that, at the point when a welding step described below is completed, a distal end portion 67 of the wire 61 protrudes from the space between the receiving part 80 and the welding part 82.Next, the wire 61 is irradiated with a laser beam to eliminate the insulation coating layer 65 on the portion of the wire 61 opposite to the portion in contact with the receiving part 80, thereby exposing the center conductor 63 of the wire 61. FIG. 3 illustrates a state in which the center conductor 63 of the wire 61 is exposed. As shown in FIG. 3, the insulation coating layer 65 remains on the distal end portion 67 of the wire 61.Next, as seen from FIGS. 1A and 1B, FIGS. 2 and 4, the folding-back part 81 is folded such that the welding part 82 faces the receiving part 80 and overlaps the same with the end portion of the wire 61 interposed therebetween, whereby the welding part 82 is brought into close proximity to or contact with the exposed center conductor 63.Next, a laser beam is applied to the welding part 82, thereby welding the welding part 82 and the exposed center conductor 63 of the wire 61 together. As a result of this laser welding, a welding ball 83 illustrated in FIGS. 1A and 1B, 2, 4, and 5A and 5B is formed.As clearly shown in FIGS. 5A and 5B, at the point where the above-mentioned welding step is completed, the distal end portion 67 of the wire 61 protrudes from the space between the receiving part 80 and the welding part 82. At this time, it suffices that the distal end portion 67 protrudes from the above-mentioned space when the coil component 40 is viewed from the front as illustrated in FIGS. 5A and 5B. Accordingly, the distal end portion 67 of the wire 61 may not be visible when the coil component 40 is viewed from below, as illustrated in FIG. 2.At the point when the welding step is completed, the insulation coating layer 65 still remains on the distal end portion 67 of the wire 61. although the insulation coating layer 65 preferably remains on the entire circumference of the center conductor 63, it suffices if the insulation coating layer 65 remains on at least the region opposite to the region in contact with the receiving part 80. In order to ensure that the insulation coating layer 65 remains as described above, the insulation coating layer 65 is preferably made of a material capable of withstanding temperatures applied to the insulation coating layer 65 in the welding step described above.As described above, the distal end portion 67 of the wire 61 protrudes from the space between the receiving part 80 and the welding part 82, and the insulation coating layer 65 remains on at least a portion of the distal end portion 67 opposite to the portion in contact with the receiving part 80. This configuration ensures that when the welding part 82 and the center conductor 63 of the wire 61 melt and liquify, and the resultant liquefied metal is about to pass beyond the receiving part 80, the liquefied metal is repelled by the insulation coating layer 65 covering the distal end portion 67 of the wire 61. This reduces undesirable deformation or melting that occurs at the terminal electrode 71 due to excessive welding.The above concludes the process of connecting the first wire 61 to the first terminal electrode 71. The same process is performed for the second, third, and fourth terminal electrodes 72, 73, and 74 to complete the coil component 40 illustrated in FIGS. 1A, 1B, and 2. Although laser welding is used for the connection between the welding part 82 and the center conductor 63 of the wire 61 in the foregoing description, this is not to be considered as restrictive. Other methods, for example arc welding, may be used for the joint.Although not illustrated in FIGS. 1A to 3, the coil component 40 may be provided with a plate core extending between the pair of flanges 43 and 44 with its one main surface in contact with the respective top surfaces 51 and 52 of the first and second flanges 43 and 44. If the drum-shaped core 42 and the plate core are both made of a magnetic material such as ferrite, the drum-shaped core 42 and the plate core form a closed magnetic circuit.Next, a coil component according to a second embodiment of the present disclosure will be described with reference to FIGS. 6A and 6B. In FIGS. 6A and 6B, wires are not illustrated, and only the substantially drum-shaped core 42 and the terminal electrodes 71 and 72 of the coil component are illustrated. In FIGS. 6A and 6B, elements corresponding to the elements illustrated in FIGS. 1A to 3 are denoted by the same reference numerals to avoid repetitive description.The coil component according to the second embodiment, which forms a single coil, includes a single terminal electrode provided for each of the first and second flanges 43 and 44, that is, a total of two terminal electrodes 71 and 72, and a single wire (not illustrated).More specifically, the first flange 43 has the recess 58 in the form of a cut-out located in an end portion of the side surface 55 near the bottom surface 49.Similarly, the second flange 44 includes the recess 59 in the form of a cut-out located in an end portion of the side surface 54 near the bottom surface 50.The coil component according to the second embodiment further includes the first and second terminal electrodes 71 and 72. the first terminal electrode 71 is attached to the first flange 43 using an adhesive. The second terminal electrode 72 is attached to the second flange 44 using an adhesive.The first terminal electrode 71 includes the base 75 and the fixing part 77. the base 75 extends along the outer end surface 47 of the flange 43. the fixing part 77 extends from the base 75 across the first bending part 67 covering the edge portion where the outer end surface 47 and the bottom surface 49 of the flange 43 meet, along the bottom surface 49 of the flange 43. further, the terminal electrode 71 includes the connecting part 79 extending from the base 75 across the second bending part 78. The connecting part 79 includes the receiving part 80 and the welding part 82. The welding part 82 extends from the receiving part 80 via the folding-back part 81 to overlap the receiving part 80 and is to be welded to an end portion of the wire. The connecting part 79 is positioned in the recess 58 provided in the first flange 43.The first terminal electrode 71 and the second terminal electrode 72 have substantially an identical shape. Accordingly, reference numerals 75, 76, 77, 78, 79, 80, 81, and 82, which are respectively used to denote the base, the first bending part, the fixing part, the second bending part, the connecting part, the receiving part, the folding-back part, and the welding part of the first terminal electrode 71, are also respectively used to denote the corresponding first bending part, fixing part, second bending part, connecting part, receiving part, folding-back part, and welding part of the second terminal electrode 72.The second terminal electrode 72 includes the base 75 and the fixing part 77. the base 75 extends along the outer end surface 48 of the flange 44. the fixing part 77 extends from the base 75 across the first bending part 76 covering the edge portion where the outer end surface 48 and the bottom surface 50 of the flange 44 meet, along the bottom surface 50 of the flange 44. further, the terminal electrode 72 includes the connection part 79 extending from the base 75 across the second bending part 78 (not illustrated in FIGS. 6A and 6B ). The connecting part 79 includes the receiving part 80 and the welding part 82. The welding part 82 extends from the receiving part 80 via the folding-back part 81 to overlap the receiving part 80 and is to be welded to an end portion of the wire. The connecting part 79 is positioned in the recess 59 provided in the second flange 44.An end portion of the wire (not illustrated) is connected to the connection part 79 of the first terminal electrode 71 provided in the first flange 43, more specifically, to the welding part 82, for example, by laser welding. Similarly, the other end portion of the wire is connected to the connection part 79 of the second terminal electrode 72 provided in the second flange 44, more specifically, to the welding part 82, for example, by laser welding. The welding ball 83 formed as a result of this laser welding is illustrated in FIGS. 6A and 6BAlthough no wire is illustrated in FIGS. 6A and 6B, also in the second embodiment, the distal end portion of the wire protrudes from the space between the receiving part and the welding part, with the insulation coating layer remaining on the distal end portion.Next, with reference to FIGS. 7A and 7B, a coil component 40 aaccording to a third embodiment of the present disclosure will be described. In FIGS. 7A and 7B, elements corresponding to the elements illustrated in FIGS. 1A to 3 are denoted by the same reference numerals to avoid repetition of the description.The characteristic feature of the coil component 40 aillustrated in FIGS. 7A and 7B is that the coil component 40 aincludes no core. The coil component 40 aincludes the wire 61 having a substantially coiled shape. The wire 61 has a center conductor having a substantially linear shape and an insulation coating layer covering the peripheral surface of the center conductor. The coil component 40 afurther includes a pair of terminal electrodes 71 and 72.The terminal electrodes 71 and 72, which have a substantially identical shape, include the base 75 and the fixing part 77 extending from the base 75 across the first bending part 76. Further, the terminal electrodes 71 and 72 each include the connection part 79 extending from the base 75 via the second bending part 78. The connection part 79 includes the receiving part 80 and the welding part 82. the receiving part 80 receives an end portion of the wire 61. The welding part 82 extends from the receiving part 80 via the folding-back part 81 to overlap the receiving part 80 and is welded to an end portion of the wire 61.An end portion of the wire 61 is connected to the connection part 79 of the first terminal electrode 71, more specifically, to the welding part 82, for example, by laser welding. Likewise, the other end portion of the wire is connected to the connection part 79 of the second terminal electrode 72, more specifically, to the welding part 82, for example, by laser welding. The welding ball 83 formed as a result of this laser welding is illustrated in FIGS. 7A and 7B.Only a small portion of the distal end portion 67 of the wire 61 is shown in FIGS. 7A and 7B. Also in the third embodiment, the distal end portion 67 of the wire 61 protrudes from the space between the receiving part 80 and the welding part 82, leaving the insulation coating layer on the distal end portion.Although the coil component according to specific embodiments of the present disclosure has been described above, it is to be noted that the above-mentioned embodiments are for illustrative purposes only and structural portions in different embodiments may be interchanged or combined with each other.

Claims

A coil component (40; 40a) comprising: a wire (61, 62) having a substantially coiled shape, the wire comprising a center conductor (63, 64) having a linear shape and an insulation coating layer (65, 66) covering a peripheral surface of the center conductor; and a terminal electrode (71-74) having a connection part (79) electrically connected to the center conductor in an end portion of the wire; wherein the connection part of the terminal electrode includes a receiving part (80) receiving the end portion of the wire and a welding part (82) extending from the receiving part via a folding-back part (81) to face the receiving part, wherein the wire is disposed between the receiving part and the welding part and the center conductor thereof is welded to the welding part in a portion from which the insulation coating layer is removed, and wherein a distal end portion (67) of the wire (61, 62) with respect to the portion from which the insulation coating layer is removed protrudes from a space between the receiving part and the welding part, wherein the insulation coating layer remains on at least a portion of the distal end portion opposite to a portion in contact with the receiving part.The coil component (40; 40a) according to claim 1, wherein the insulation coating layer (65, 66) remains on an entire periphery of the distal end portion (67) of the wire (1).The coil component (40; 40a) according to claim 1 or 2, wherein the insulation coating layer (65, 66) of the wire (61, 62) is present in a portion of the wire that is in contact with the receiving part (80).The coil component (40; 40a) according to any one of claims 1 to 3, further comprising: a core (42) including a core part (41) and a flange (43, 44) provided in an end portion of the core part, wherein the wire (61, 62) is wound around the core part in a substantially coiled manner.The coil component (40; 40a) according to claim 4, wherein the flange (43, 44) comprises a bottom surface (49, 50) facing a mounting plate when the coil component is mounted to the mounting plate, and wherein the terminal electrode (71-74) is arranged such that at least a part of the terminal electrode extends along the bottom surface.The coil component (40; 40a) according to any one of claims 1 to 5, wherein the insulation coating layer (65, 66) is made of a material capable of withstanding a temperature applied to the insulation coating layer when the center conductor (63, 64) and the welded part (82) are welded together.

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