Patent Publication Number: US-11024459-B2

Title: Method of manufacturing coil component

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of priority to Japanese Patent Application 2016-196821 filed Oct. 5, 2016, the entire content of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a method of manufacturing a coil component, and more particularly to a method of connecting a wire and a metal terminal to each other. 
     BACKGROUND 
     As a technique of interest related to the present disclosure, for example, there has been known a technique described in Japanese patent 4184394.  FIG. 16  and  FIG. 17  are drawings cited from Japanese patent 4184394, and correspond to FIG. 2 and FIG. 4 in Japanese patent 4184394, respectively.  FIG. 9  and  FIG. 10  show one flange portion  1  which forms a portion of a core provided to a coil component, a metal terminal  2  disposed on the flange portion  1 , and an end portion of a wire  3  connected to the metal terminal  2 . 
     As shown in  FIG. 16  and  FIG. 17 , the wire  3  includes: a conductive wire portion  4  made of a conductor; and an insulating resin coating  5  which covers a peripheral surface of the conductive wire portion  4 . The metal terminal  2  includes: a base portion  7  disposed on an outer end surface  6  side of the flange portion  1 ; and a receiving portion  9  extending from the base portion  7  by way of a bent portion  8  and receiving the end portion of the wire  3 . The metal terminal  2  further includes: a welding portion  11  extending from the receiving portion  9  by way of a first folding portion  10  and welded to the conductive wire portion  4  of the wire  3 ; and a holding portion  13  extending from the receiving portion  9  by way of a second folding portion  12  and positioning the wire  3  by holding the wire  3 . 
     With respect to the above-mentioned welding portion  11 , a state of the welding portion  11  before a welding step is performed is shown in  FIG. 16 , and a state of the welding portion  11  after the welding step is performed is shown in  FIG. 17 . In  FIG. 17 , a melted ball  14  formed by welding is shown. The melted ball  14  is formed in such a manner that molten metal formed by welding is formed into a ball shape by surface tension, and the molten metal is solidified by being cooled while keeping a ball shape. 
     The detail of a step of connecting the wire  3  to the metal terminal  2  is described hereinafter. In a stage before such a connecting step is performed, in the metal terminal  2 , the welding portion  11  and the holding portion  13  are in a state where the welding portion  11  and the holding portion  13  are opened with respect to the receiving portion  9  so that neither the welding portion  11  nor the holding portion  13  face the receiving portion  9 .  FIG. 16  shows a state where the welding portion  11  is opened with respect to the receiving portion  9  although the holding portion  13  faces the receiving portion  9 . 
     Firstly, the wire  3  is placed on the receiving portion  9  of the metal terminal  2 . To fix this state temporarily, the holding portion  13  is folded with respect to the receiving portion  9  by way of the second folding portion  12  such that the wire  3  is sandwiched between the receiving portion  9  and the holding portion  13 . 
     Next, as shown in  FIG. 16 , a portion of the insulating resin coating  5  of the wire  3  disposed on a more distal end side than the holding portion  13  is removed. For example, a laser beam is irradiated to the insulating resin coating  5  for removing the insulating resin coating  5 . As can be clearly understood from  FIG. 16 , a portion of the insulating resin coating  5  which is in contact with the receiving portion  9  is left without being removed. 
     Next, the welding portion  11  is folded with respect to the receiving portion  9  by way of the first folding portion  10  thus bringing about a state where the wire  3  is sandwiched between the welding portion  11  and the receiving portion  9 . 
     Then, the conductive wire portion  4  of the wire  3  and the welding portion  11  are welded to each other. To be more specific, laser welding is applied. A laser beam is irradiated to the welding portion  11  so that the conductive wire portion  4  of the wire  3  and the welding portion  11  are melted to each other. A liquefied molten portion is formed into a ball shape by surface tension. Thereafter, the molten portion is solidified while keeping a ball shape so that the melt ball  14  is formed. 
     SUMMARY 
     In the technique described in Japanese patent 4184394, to temporarily fix the wire  3  before welding is performed, a state is brought about where the holding portion  13  faces the receiving portion  9  by bending the holding portion  13  by way of the second folding portion  12  thus bringing about a state where the wire  3  is sandwiched between the holding portion  13  and the receiving portion  9 . However, in such a step, there is a possibility that the position of the wire  3  is displaced. 
     Further, in the above-mentioned temporary fixing step, after the state where the wire  3  is sandwiched between the holding portion  13  and the receiving portion  9  is brought about, a compression bonding step is performed so as to bring the holding portion  13  and the receiving portion  9  into close contact with each other. Also in this compression bonding step, there is a possibility that the position of the wire  3  is displaced. 
     The present disclosure has been made in view of such circumstances, and it is an object of the present disclosure to provide a method of manufacturing a coil component capable of making the above-mentioned positional displacement of a wire only minimally occur. 
     According to a first aspect of the present disclosure, there is provided a method of manufacturing a coil component which includes: a wire; and a metal terminal having a connecting portion which is electrically connected to an end portion of the wire. 
     To overcome the above-mentioned technical drawbacks, the method of manufacturing a coil component according to the present disclosure includes: preparing the metal terminal having the connecting portion on which a positioning groove for receiving and positioning a portion of the wire is formed; a positioning step of positioning the wire by fitting the wire in the positioning groove; a temporary fixing step of temporarily fixing the wire to the connecting portion; and a welding step of welding the wire and the metal terminal to each other by irradiating a laser beam. 
     In the present disclosure, the positioning groove formed on the connecting portion of the metal terminal functions so as to make undesired positional displacement of the wire difficult. 
     It is preferable that the wire include: a conductive wire portion made of a conductor and an insulating resin coating which covers a peripheral surface of the conductive wire portion, and the temporary fixing step include a thermocompression bonding step where the wire is adhered to the positioning groove using the melted insulating resin coating as an adhesive agent by applying heat and pressure to the wire positioned by being fitted in the positioning groove. By performing the temporary fixing step in this manner, the wire can be temporarily fixed by making use of the insulating resin coating which the wire includes as an adhesive agent. 
     In the above-mentioned preferred mode of the present disclosure, it is preferable that the metal terminal which includes a receiving portion on which a positioning groove is formed and a contact portion extending from the receiving portion via a bending scheduled portion in the connecting portion, the temporary fixing step further includes a contacting step where, after the above-mentioned thermocompression bonding step is finished, the connecting portion is bent via the bending scheduled portion such that the contact portion faces the receiving portion with the wire interposed therebetween and is brought into contact with the wire, and a laser beam be irradiated to the contact portion in the welding step. With such a configuration, the contact portion can perform temporary fixing of the wire with more certainty. 
     In the above-mentioned preferred mode of the present disclosure, a direction that the positioning groove extends and a direction that the bending scheduled portion extends are parallel to each other, and the positioning groove and the bending scheduled portion be not located on the same line. With such a configuration, bending at the bending scheduled portion does not overlap with the positioning groove and hence, positioning of the wire fitted in the positioning groove becomes stable. 
     In the above-mentioned temporary fixing step, in place of the thermocompression bonding step or in addition to the thermocompression bonding step, it may be possible to perform a step of preparing a pressing segment where the pressing segment and the connecting portion sandwich the wire positioned by being fitted in the positioning groove, and a step of fixing the wire by pressing the wire toward the connecting portion by the pressing segment. The pressing segment is disposed on a manufacturing facility side so that it is unnecessary to provide the previously mentioned contact portion to the metal terminal. When the contact portion is not provided to the metal terminal, the shape of the metal terminal can be further simplified. 
     It is preferable that the positioning groove be formed in a V shape in cross section. By forming the positioning groove in a V shape in cross section, it is possible to perform positioning of the wire with high accuracy with respect to a direction orthogonal to the direction that the positioning groove extends. 
     It is preferable that the positioning groove be located within a region where welding is scheduled in the welding step. With such a configuration, it is possible to acquire a state where the positioning groove does not remain after the welding step is finished. 
     According to the present disclosure, positioning displacement of the wire is minimally generated due to the formation of the positioning groove and hence, welding of the connecting portion of the metal terminal and the wire can be performed with a proper positional relationship. Accordingly, it is possible to prevent the occurrence of a connection defect of the wire or a defect of appearance of a product which may be caused when the positional displacement of the wire is generated as much as possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view showing an external appearance of one example of a coil component manufactured by a manufacturing method according to the present disclosure. 
         FIG. 2  is a perspective view showing a coil component  20  shown in  FIG. 1  as viewed from a bottom surface side. 
         FIG. 3  is a bottom surface view showing a portion of the coil component  20  shown in  FIG. 1  and  FIG. 2 , wherein a metal terminal  41 , a portion of a flange portion  23  of a core on which the metal terminal  41  is disposed, and a wire  35  which is connected to the metal terminal  41  are shown. 
         FIG. 4  is a cross-sectional view of the metal terminal  41  taken along line IV-IV in  FIG. 3 . 
         FIG. 5  is a plan view for describing a manufacturing method according to a first embodiment of the present disclosure, particularly, a connecting step of connecting the metal terminal and the wire  35  shown in  FIG. 3  to each other, wherein a developed state of the metal terminal  41  before the metal terminal  41  is bent is shown. 
         FIG. 6  is a cross-sectional view taken along line VI-VI in  FIG. 5 . 
         FIG. 7  is a plan view showing a state where the wire  35  is positioned on a connecting portion  49  of the metal terminal  41  shown in  FIG. 5 . 
         FIG. 8  is a cross-sectional view taken along line VIII-VIII in  FIG. 7 . 
         FIG. 9  is a plan view showing a state where the wire  35  is temporarily fixed onto the connecting portion  49  of the metal terminal  41  after the step shown in  FIG. 7  is finished. 
         FIG. 10  is a cross-sectional view taken along line IX-IX in  FIG. 9 . 
         FIG. 11  is a plan view showing a state where, after the step shown in  FIG. 9  is finished, the connecting portion  49  is bent such that a contact lug  51  overlaps with a receiving portion  50 , and the wire  35  is sandwiched between the receiving portion  50  and the contact lug  51 . 
         FIG. 12  is a plan view for describing a manufacturing method according to a second embodiment of the present disclosure, particularly, a connecting step of connecting a metal terminal  41   a  and a wire  35  to each other, wherein the metal terminal  41   a  is shown. 
         FIG. 13  is a plan view showing a state where the wire is positioned on a connecting portion  49   a  of the metal terminal  41   a  shown in  FIG. 12 . 
         FIG. 14  is a plan view showing a state where, after the step shown in  FIG. 13  is finished, the wire  35  is temporarily fixed onto the connecting portion  49   a  of the metal terminal  41   a , and a state where the wire  35  is pressed toward the connecting portion  49   a  by a pressing segment  63 . 
         FIG. 15  is a plan view showing a state where the wire  35  and the metal terminal  41   a  are welded to each other after the step shown in  FIG. 14  is finished. 
         FIG. 16  is a perspective view showing a flange portion  1  of a core provided to a coil component disclosed in Japanese patent 4184394, a metal terminal  2  disposed on the flange portion  1 , and a wire  3  connected to the metal terminal  2 , wherein  FIG. 16  shows a state of these portions before a welding step is performed. 
         FIG. 17  is a perspective view showing a state of the portions shown in  FIG. 16  after the welding step is performed. 
     
    
    
     DETAILED DESCRIPTION 
     The structure of a coil component  20  which is manufactured by a manufacturing method according to the present disclosure is described mainly with reference to  FIG. 1  and  FIG. 2 . To be more specific, the coil component  20  shown in  FIG. 1  and  FIG. 2  forms a common mode choke coil as one example of a coil component. 
     The coil component  20  includes a core  22  having a winding core portion  21 . The core  22  has a drum shape, and includes a first flange portion  23  and a second flange portion  24  which are formed on end portions of the winding core portion  21  respectively. The core  22  is made of a magnetic material such as ferrite, for example. 
     The flange portions  23 ,  24  respectively have: an inner end surface  25 ,  26  which faces a winding core portion  21  side and at which each end portion of the winding core portion  21  is positioned; and an outer end surface  27 ,  28  which faces the outside on a side opposite to the inner end surface  25 ,  26 . Further, the flange portions  23 ,  24  respectively have a bottom surface  29 ,  30  which faces a printed circuit board (not shown in the drawing) side when the coil component  20  is actually mounted. 
     Recesses  31 ,  32  each having a cutout shape are formed on both end portions of the bottom surface  29  of the first flange portion  23  respectively. In the same manner, recesses  33 ,  34  each having a cutout shape are formed on both end portions of the bottom surface  30  of the second flange portion  24  respectively. 
     The coil component  20  further includes first and second wires  35 ,  36  which are spirally wound around the winding core portion  21 . As shown in  FIG. 9  and  FIG. 10  described later, each of the wires  35 ,  36  has: a conductive wire portion  37  made of a conductor; and an insulating resin coating  38  which covers a periphery of the conducive wire portion  37 . The conductive wire portion  37  is formed of a copper wire, for example. The insulating resin coating  38  is made of a resin such as polyurethane, polyimide, polyesterimide or polyamideimide, for example. 
     When the coil component  20  is a common mode choke coil, the wires  35 ,  36  are wound in the same direction. In this case, the wires  35 ,  36  may be wound in a double-layered manner such that either one of the wires is wound on an inner layer side, and the other wire is wound on an outer layer side, or may be wound by bifilar winding such that the wires are disposed alternately and parallel to each other in an axial direction of the winding core portion  21 . 
     The coil component  20  further includes first to fourth metal terminals  41  to  44 . Out of these first to fourth metal terminals  41  to  44 , the first and third metal terminals  41 ,  43  are fixed to the first flange portion  23  by way of an adhesive agent. The second and fourth metal terminals  42 ,  44  are fixed to the second flange portion  24  by way of an adhesive agent. 
     The first metal terminal  41  and the fourth metal terminal  44  have the same shape, and the second metal terminal  42  and the third metal terminal  43  have the same shape. The first metal terminal  41  and the third metal terminal  43  have shapes which are in plane symmetry with each other, and the second metal terminal  42  and the fourth metal terminal  44  have shapes which are in plane symmetry with each other. Accordingly, the detailed description is made with respect to one of first to fourth metal terminals  41  to  44 , for example, the first metal terminal  41 , and the detailed description of the second, third and fourth metal terminals  42 ,  43  and  44  is omitted. 
     In  FIG. 3  to  FIG. 11 , the metal terminal  41  or a portion of the metal terminal  41  is shown. 
     Usually, the metal terminal  41  is manufactured by applying sheet metal working to one metal sheet made of a copper-based alloy such as phosphor bronze or tough pitch copper, for example. However, the metal terminal  41  may be manufactured by other manufacturing methods such as casting, for example. 
     The metal terminal  41  includes: a base portion  45  extending along the outer end surface  27  of the flange portion  23 ; and a mounting portion  47  extending from the base portion  45  along the bottom surface  29  of the flange portion  23  by way of a first bent portion  46  which covers a ridge portion of the flange portion  23  where the outer end surface  27  and the bottom surface intersect with each other. When the coil component  20  is mounted on a printed circuit board not shown in the drawing, the mounting portion  47  forms a portion which is electrically and mechanically connected to a conductive land on the printed circuit board by soldering or the like. 
     The metal terminal  41  includes a connecting portion  49  extending from the mounting portion  47  by way of a second bent portion  48 . Due to the formation of the second bent portion  48 , the metal terminal  41  has an S-shaped bent shape. The connecting portion  49  has both a function of positioning the wire  35  by receiving the wire  35  and a function of electrically and mechanically connecting the wire  35  to the metal terminal  41 . 
     To be more specific, the connecting portion  49  includes: a receiving portion  50  which receives the wire  35 ; and a contact lug  51  which extends by way of a joint portion  52  folded from the receiving portion  50  so as to overlap with the receiving portion  50  and is brought into contact with the wire  35  so as to position the wire  35  between the contact lug  51  and the receiving portion  50 . The connecting portion  49  is positioned in the recess  31  formed on the first flange portion  23 . 
     A positioning groove  61  for receiving and positioning a portion of the wire  35  is formed on a receiving portion  50  side of the connecting portion  49 . The positioning groove  61  is shown in  FIG. 5  to  FIG. 10 . The positioning groove  61  extends toward the inside from a distal end of the receiving portion  50  of the connecting portion  49 . The positioning groove  61  defines a space having a triangular pyramid shape. As clearly shown in  FIG. 6 , the closer the positioning groove  61  to the distal end of the receiving portion  50 , the deeper a depth of the positioning groove  61  becomes, while as clearly shown in  FIG. 5 , the closer the positioning groove  61  to the distal end of the receiving portion  50 , the wider a width of the positioning groove  61  becomes. The positioning groove  61  has an isosceles triangular planar shape as clearly shown in  FIG. 5 , and has a V-shaped cross section as clearly shown in  FIG. 10 . 
     The depth and the width of the positioning groove  61  can be arbitrarily set provided that the positioning groove  61  can perform a function of receiving and positioning a portion of the wire  35  in the positioning groove  61 . For example, it is preferable to set the depth and the width of the positioning groove  61  such that a portion of the wire  35  having the sizes which are ⅓ to ½ inclusive of a diameter of the wire  35  can be received in the positioning groove  61  at a deepest and widest portion of the positioning groove  61 . 
     It is unnecessary to form the positioning groove  61  over the whole length of the receiving portion  50  of the connecting portion  49 . That is, it is unnecessary to form the positioning groove  61  such that the positioning groove  61  traverses the receiving portion  50  in the longitudinal direction. The positioning groove  61  is formed only in a limited region of a distal end portion of the receiving portion  50  of the connecting portion  49 . Further, as described previously, the positioning groove  61  defines a space having a triangular pyramid shape. Accordingly, when the wire  35  pulled out from a wire nozzle (not shown in the drawing) is received in the positioning groove  61 , as shown in  FIG. 8 , the wire  35  is inclined with respect to an extending surface of the receiving portion  50  so that a gap  62  is formed on a proximal end side of the receiving portion  50 . 
     In this embodiment, as clearly shown in  FIG. 10 , the positioning groove  61  is formed by applying coining which decreases a thickness of a portion of the metal sheet to a metal sheet used for forming the metal terminal  41 . However, the positioning groove  61  may be formed by applying embossing where a portion of the metal sheet is extruded while maintaining a thickness of the metal sheet to a substantially fixed thickness. 
     The reference symbols  45 ,  46 ,  47 ,  48 ,  49 ,  50 ,  51 ,  52  and  61  which are used for indicating the base portion, the first bent portion, the mounting portion, the second bent portion, the connecting portion, the receiving portion, the contact lug, the joint portion, and the positioning groove in the previously described first metal terminal  41  may be also used for indicating the corresponding base portions, the corresponding first bent portions, the corresponding mounting portions, the corresponding second bent portions, the corresponding connecting portions, the corresponding receiving portions, the corresponding contact lugs, the corresponding joint portions, and corresponding positioning grooves in the second, third and fourth metal terminals  42 ,  43  and  44 . 
     There may be a case where the reference symbols  45 ,  46 ,  47 ,  48 ,  49 ,  50 ,  51  and  52  used for indicating the base portion, the first bent portion, the mounting portion, the second bent portion, the connecting portion, the receiving portion, the contact lug and the joint portion of the above-mentioned first metal terminal  41  respectively are also used for indicating the base portions, the first bent portions, the mounting portions, the second bent portions, the connecting portions, the receiving portions, the contact lugs, and the joint portions of the second, third and fourth metal terminals  42 ,  43  and  44  which correspond to the above-mentioned portions of the first metal terminal  41 . 
     In a stage before the wire  35  is connected to the first metal terminal  41 , as shown in  FIG. 5 , the metal terminal  41  is in a state where the contact lug  51  is developed with respect to the receiving portion  50  in the connecting portion  49 . In such a state, an end portion of the wire  35  which is wound around the winding core portion  21  is pulled out onto the receiving portion  50  of the connecting portion  49  of the metal terminal  41  by a wire nozzle, and is positioned on the receiving portion  50  of the connecting portion  49 . In this case, as shown in  FIG. 7  and  FIG. 8 , the wire  35  is positioned such that the wire  35  is fitted in the positioning groove  61 . 
     Next, the wire  35  is temporarily fixed to the receiving portion  50  of the connecting portion  49 . For this temporary fixing, the thermocompression bonding step is performed where heat and pressure are applied to the wire  35  in a state where the wire  35  is placed on the receiving portion  50 . In the thermocompression bonding step, for example, a heater chip  53  which heats a region indicated by a dotted line in  FIG. 7  is used. When the wire  35  on the receiving portion  50  of the connecting portion  49  is pressed while being heated by the heater chip  53 , the insulating resin coating  38  is melted or softened. As a result, as shown in  FIG. 9  and  FIG. 10 , a melted/softened material  54  derived from the insulating resin coating  38  functions as an adhesive agent so that the wire  35  is adhered to the positioning groove  61  on the receiving portion  50  by way of the melted/softened material  54 . At this stage of operation, as a result of pressurizing in the thermocompression bonding step, the conductive wire portion  37  of the wire  35  is generally formed into a flat shape in cross section as shown in  FIG. 10 . 
     In the temporary fixing step, a place where the wire  35  is adhered may not always be the positioning groove  61 . The wire  35  may be adhered to an area in the vicinity of the positioning groove  61  on the receiving portion  50 . 
     It is preferable that, as a result of the above-mentioned thermocompression bonding step, as shown in  FIG. 10  clearly, the conductive wire portion  37  be brought into a state where a portion of the insulating resin coating  38  positioned on a side opposite to a receiving portion  50  side is removed so that the conductive wire portion  37  is exposed from the insulating resin coating  38 . To acquire such a state where the conductive wire portion  37  is exposed from the insulating resin coating  38  in the thermocompression bonding step, for example, the thermocompression bonding step is performed under the following conditions. 
     First, as the heater chip  53 , a heater chip having an area sufficient to cover the wire  35  and the receiving portion  50  of the connecting portion  49  is used, and a contact surface of the heater chip  53  is a planar surface having a smooth surface. When the insulating resin coating  38  is made of polyamideimide, a temperature which falls within a range of from 400° C. to 550° C. inclusive is adopted as a thermocompression bonding temperature, and a thermocompression bonding time is set to 2 seconds or less. In this case, the insulating resin coating  38  is removed only at a portion where the heater chip  53  is brought into contact with the insulating resin coating  38 . On the other hand, at portions of the insulating resin coating  38  where the heater chip  53  and the insulating resin coating  38  are not brought into contact with each other, melting of the insulating resin coating  38  due to the heat conduction is not completed so that the insulating resin coating  38  contributes to bonding between the wire  35  and the receiving portion  50  of the connecting portion  49  in a state where the insulating resin coating  38  remains in an incomplete melted state. 
     When the exposure of the conductive wire portion  37  from the insulating resin coating  38  is insufficient, the insulating resin coating  38  may be removed by irradiation of a laser beam, for example. The exposure of the conductive wire portion  37  from the insulating resin coating  38  is not always necessary, and succeeding steps may be performed in a state where the exposure of the conductive wire portion  37  from the insulating resin coating  38  is insufficient or in a state where there is no exposure of the conductive wire portion  37  from the insulating resin coating  38 . 
     A portion of the wire  35  projecting from the receiving portion  50  of the connecting portion  49  is removed by cutting simultaneously with the above-mentioned thermocompression bonding step. 
     Next, a contacting step is performed where the joint portion  52  is bent at a bending scheduled portion  55  indicated by a dotted chain line in  FIG. 9 . Due to such bending in the contacting step, as shown in  FIG. 11 , the contact lug  51  is brought into contact with the wire  35  and, at the same time, the contact lug  51  is made to overlap with the receiving portion  50  in a state where the contact lug  51  faces the receiving portion  50  with the wire  35  sandwiched therebetween. When the contact lug  51  is brought into contact with the wire  35 , it is preferable that the contact lug  51  be brought into contact with the conductive wire portion  37  exposed from the insulating resin coating  38 . 
     In the above-mentioned contacting step, in a state where a portion of the metal terminal  41  ranging from the base portion  45  to the mounting portion  47  is fixed, the contact lug  51  of the connecting portion  49  in a state shown in  FIG. 9  is pushed up by a tool from a back side to a front side of a paper surface on which  FIG. 9  is drawn so that, firstly, the metal terminal  41  is brought into a state where the contact lug  51  is bent by 90 degrees about the bending scheduled portion  55 . Next, the tool is brought into contact with and is pressed to the contact lug  51  from a lateral side so that the contact lug  51  is bent at 90 degrees thus further bending the contact lug  51  by 90 degrees about the bending scheduled portion  55 . With such operations, a state shown in  FIG. 11  is obtained so that the contact lug  51  and the wire  35  are brought into contact with each other. 
     In this embodiment, although a direction that the positioning groove  61  extends and a direction that the bending scheduled portion  55  extends are parallel to each other, the positioning groove  61  and the bending scheduled portion  55  are not positioned on the same line. With such a configuration, bending at the bending scheduled portion  55  does not overlap with the positioning groove  61  and hence, positioning of the wire fitted in the positioning groove  61  becomes stable. 
     The positioning groove  61  is not formed to extend in the bending direction of the bending scheduled portion  55  over the whole width of the bending scheduled portion  55 . With such a configuration, it is possible to prevent the metal terminal  41  from being erroneously bent at the position of the positioning groove  61  at the time of bending the metal terminal  41  so that the metal terminal  41  can be bent at the bending scheduled portion  55  with certainly. 
     After the contact lug  51  and the wire  35  are brought into contact with each other as described above, preferably, a caulking step is performed so as to bring the receiving portion  50  and the contact lug  51  into close contact with each other. In the caulking step, it is preferable that the receiving portion  50  and the contact lug  51  be bonded to each other by pressure bonding in a state where a heater heated to 500° C., for example, is brought into pressure contact with the contact lug  51 , and the wire  35  is sandwiched between the receiving portion  50  and the contact lug  51 . According to this caulking step, it is possible to bring a close contact state between the contact lug  51  and the wire  35  with certainty against a spring back phenomenon which is liable to occur at the time of bending the connecting portion  49  of the metal terminal  41 . Further, the formation of gaps between the wire  35 , the receiving portion  50  and the contact lug  51  can be substantially eliminated. 
     Next, a welding step is performed. In the welding step, it is preferable that a laser beam be irradiated to a surface of the contact lug  51  on a side opposite to a surface of the contact lug  51  which is adhered to the wire  35 . In  FIG. 11 , a laser beam irradiation position  56  is shown. As one example, a laser beam having a wavelength of 1064 nm is irradiated for several milliseconds to a portion of the contact lug  51  displaced inward by 0.1 mm from a distal end of the contact lug  51 . 
     In the above-mentioned laser welding step, as shown in  FIG. 4 , the receiving portion  50  and the contact lug  51  are integrally formed with each other by way of a melted ball  57  at a position different from the joint portion  52 . The melted ball  57  is formed by laser welding. In this embodiment, the receiving portion  50  and the contact lug  51  are integrally formed with each other by way of the melted ball  57  at respective distal end portions of the receiving portion  50  and the contact lug  51 . Further, as shown in  FIG. 4 , it is possible to bring about a state where the whole periphery of the end portion of the wire  35  is covered by the melted ball  57 . That is, the end portion of the wire  35  is positioned in the melted ball  57 . The wire  35  has a small thickness at a boundary portion between a portion deformed by thermocompression bonding and a non-deformed portion so that the wire  35  is liable to be easily broken at the boundary portion. In view of the above, it is preferable that the whole portion of the wire  35  deformed by thermocompression bonding be enclosed in the melted ball  57 . With such a configuration, the wire  35  has no thin portion so that the wire  35  is minimally broken. 
     In this embodiment, the above-mentioned positioning groove  61  is positioned within a region where welding is scheduled in the welding step. With such a configuration, it is possible to acquire a state where the positioning groove  61  does not remain after the welding step is finished. 
     The receiving portion  50  and the contact portion  51  of the metal terminal  41  are respectively formed such that a width on a proximal side is narrower than a width of a distal end portion. By adopting such a shape, it is possible to make the temperature elevation brought about by the welding step only minimally transferred to a core  22  side. 
     In the above-mentioned welding step, a laser beam may be irradiated to a portion of the contact lug  51  other than the surface of the contact lug  51  on a side opposite to the surface of the contact lug  51  which is adhered to the wire  35 . For example, a laser beam may be irradiated to a surface of the receiving portion  50  which is adhered to the wire  35 . 
     Although the description has been made with respect to the connection between the first metal terminal  41  and the first wire  35 , substantially the same steps are performed also with respect to the connections between other metal terminals  42  to  44  and the wire  35  or  36  so that the coil component  20  shown in FIG.  1  and  FIG. 2  is completed. 
     Next, a second embodiment of the present disclosure is described with reference to  FIG. 12  to  FIG. 15 . The second embodiment is characterized in that a contact portion is not formed on a connecting portion of a metal terminal compared to the first embodiment.  FIG. 12  corresponds to  FIG. 5 ,  FIG. 13  corresponds to  FIG. 7 ,  FIG. 14  corresponds to  FIG. 9 , and  FIG. 15  partially corresponds to  FIG. 3 . In  FIG. 12  to  FIG. 15 , constitutional elements corresponding to the constitutional elements shown in  FIG. 5 ,  FIG. 7 ,  FIG. 9  and  FIG. 3  are given the same symbols, and the repeated description of these constitutional elements is omitted. 
     Also in the second embodiment, the description is made with respect to a first metal terminal  41   a . In  FIG. 12 , a portion of a second bent portion  48  which the metal terminal  41   a  includes is shown. The metal terminal  41   a  of the second embodiment also includes the configuration of the metal terminal  41  of the first embodiment ranging from the base portion  45  to the second bent portion  48 . 
     A connecting portion  49   a  of the metal terminal  41   a  includes only a portion corresponding to the receiving portion  50  in the first embodiment. A positioning groove  61  is formed on the connecting portion  49   a . The positioning groove  61  has substantially the same shape as the positioning groove  61  of the first embodiment, and is formed at substantially the same position as the positioning groove  61  of the first embodiment. 
     As shown in  FIG. 13 , an end portion of a wire  35  wound around a winding core portion is pulled out onto the connecting portion  49   a  of the metal terminal  41   a  by a wire nozzle, and is positioned on the connecting portion  49   a . In such a state, the wire  35  is positioned such that the wire  35  is fitted in the positioning groove  61 . 
     Next, the wire  35  is temporarily fixed to the connecting portion  49   a . For this temporary fixing, a thermocompression bonding step is performed in the same manner as in the case in the first embodiment. In  FIG. 13 , a region to be heated by a heater chip  53  is shown by a dotted line. When the wire  35  on the connecting portion  49   a  is pressed while being heated by the heater chip  53 , the insulating resin coating  38  is melted or softened. As a result, as shown in  FIG. 14 , a melted/softened material  54  derived from the insulating resin coating  38  functions as an adhesive agent so that the wire  35  is adhered to the connecting portion  49   a  by way of the melted/softened material  54 . 
     A portion of the wire  35  projecting from the connecting portion  49   a  is removed by cutting simultaneously with the above-mentioned thermocompression bonding step. 
     In  FIG. 14 , a pressing segment  63  is shown. The pressing segment  63  is disposed on a manufacturing facility side, and is provided for fixing the wire  35  by pressing the wire  35  toward the connecting portion  49   a . Preferably, the pressing segment  63  has a spring property and is resiliently brought into contact with the wire  35 . The following welding step is performed in a state where the pressing segment  63  presses the wire  35 . 
     A state where the pressing segment  63  presses the wire  35  may be taken at a stage where the above-mentioned temporary fixing step is performed. In this case, temporary fixing may be realized only by pressing the wire  35  by the pressing segment  63  without performing the thermocompression bonding step in the temporary fixing step. 
     Next, the welding step is performed. In the welding step, a laser beam is irradiated to a portion of the connecting portion  49   a  which is adhered to the wire  35 . In  FIG. 15 , a melted ball  57   a  generated after welding is performed is shown. The melted ball  57   a  is formed in such a manner that a conductive wire portion  37  of the wire  35  and the connecting portion  49   a  are melted to each other, and a liquefied melted portion is formed into a ball shape by surface tension and, thereafter, the melted portion is solidified by being cooled while keeping a ball shape. 
     Also in the second embodiment, the positioning groove  61  is positioned within a region where welding is scheduled in the welding step. Accordingly, the positioning groove  61  does not remain after the welding step is finished. 
     In the second embodiment, the description has been made with respect to the connection between the first metal terminal  41   a  and the first wire  35 . However, substantially the same steps are performed also with respect to the connections between other metal terminals and the wire. 
     Although the description has been made with respect to the coil component manufactured by the manufacturing method of the present disclosure based on the specific embodiment, the embodiment is merely described exemplarily, and various other modifications are conceivable. 
     For example, although not shown in  FIG. 1  and  FIG. 2 , a plate-like core which extends between a pair of first and second flange portions  23 ,  24  may be provided in a state where a main surface of the core on one side is brought into contact with respective ceiling surfaces of the first and second flange portions  23 ,  24 . In this case, when both a drum-shaped core  22  and the plate-like core are made of a magnetic material such as ferrite, a closed magnetic circuit is formed by the drum-shaped core  22  and the plate-like core. 
     The drum-shaped core  22  may be made of a non-magnetic material such as a resin, for example. 
     A coil component which is manufactured by the manufacturing method of the present disclosure may be a coil component having no core. 
     The number of wires which the coil component has and the number of metal terminals which the coil component has may be changed corresponding to a function of the coil component. 
     Although the present disclosure has been described with reference to the first embodiment and the second embodiment, the configuration of one embodiment may be partially replaced with the configuration of the other embodiment, or the configuration of one embodiment and the configuration of the other embodiment may be combined with each other.