Patent Publication Number: US-11657952-B2

Title: Coil component

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of priority to Japanese Patent Application No. 2019-179011, filed Sep. 30, 2019, the entire content of which is incorporated herein by reference. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a coil component. 
     Background Art 
     As a coil component of the related art, a coil component that includes metal magnetic particles and a magnetic portion made of resin in which a coil conductor is buried in the magnetic portion, and an end of the coil conductor is extended to a surface of the magnetic portion is disclosed, for example, in Japanese Patent Application Laid-Open No. 2019-080073. 
     SUMMARY 
     In the coil component disclosed in Japanese Patent Application Laid-Open No. 2019-080073, an insulating film is coated on a surface of the coil conductor. When the coil component including such a coil conductor is mounted on a mounting substrate by using solder by reflow, the coil component may expand due to heating during mounting. When the coil component expands, deviation occurs at an interface between the coil conductor and the resin in the magnetic portion due to a difference in thermal expansion coefficient between the coil conductor and the resin in the magnetic portion (usually the resin has a larger thermal expansion coefficient), and thus, there is a concern that peeling at the interface occurs. 
     Thus, the present disclosure provides a coil component capable of suppressing occurrence of peeling at an interface between a coil conductor and resin in a magnetic portion due to heating during mounting. 
     A coil component according to the present disclosure includes an element body that includes a coil conductor formed by winding a conductive wire coated with an insulating film, and a magnetic portion that contains metal magnetic particles and resin, and external electrodes that are electrically connected to exposed surfaces of extended portions of the coil conductor exposed on a surface of the element body, and are arranged on the surface of the element body. The metal magnetic particles are arranged in recesses formed in a surface of the conductive wire in the extended portions of the coil conductor. 
     In the coil component according to the present disclosure, since the recesses are formed on the surfaces of the extended portions of the coil conductor and the metal magnetic particles contained in the magnetic portion are arranged in the recesses, an anchor effect occurs on the coil conductor by the metal magnetic particles, and thus, the bonding strength between the magnetic portion and the coil conductor can be improved. 
     According to the present disclosure, it is possible to provide the coil component capable of suppressing the occurrence of peeling at the interface between the coil conductor and the resin in the magnetic portion due to heating during mounting. 
     The above-mentioned objects, other objects, features, and advantages of the present disclosure will become more apparent from the following description of the embodiments for carrying out the disclosure with reference to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an external perspective view schematically illustrating an embodiment of a coil component of the present disclosure; 
         FIG.  2    is a transparent perspective view of a magnetic portion in which a coil conductor is buried in the coil component illustrated in  FIG.  1   ; 
         FIG.  3    is a sectional view taken along a line III-III of  FIG.  1    illustrating the coil component according to the present disclosure; 
         FIG.  4    is a sectional view taken along the line IV-IV in  FIG.  1    illustrating the coil component according to the present disclosure; 
         FIG.  5    is a transparent perspective view illustrating a first modification example of an element body of a coil component according to an embodiment of the present disclosure; 
         FIG.  6 A  is a transparent perspective view illustrating a second modification example of the element body of the coil component according to the embodiment of the present disclosure, and  FIG.  6 B  is a transparent perspective view seen in a direction different from  FIG.  6 A ; 
         FIG.  7 A  is a sectional view taken along a line V-V of  FIG.  1    illustrating the coil component according to the present disclosure, and  FIG.  7 B  is an enlarged sectional view of a portion a in  FIG.  7 A ; 
         FIG.  8    is an enlarged sectional view illustrating a first modification example of a structure on peripheries of extended portions of the coil conductor; 
         FIG.  9    is an enlarged sectional view illustrating a second modification example of the structure on the peripheries of extended portions of the coil conductor; 
         FIG.  10    is an enlarged sectional view illustrating a third modification example of the structure on the peripheries of the extended portions of the coil conductor; 
         FIG.  11 A  is an enlarged sectional view illustrating a fourth modification example of the structure on the peripheries of the extended portions of the coil conductor, and  FIG.  11 B  is an enlarged view illustrating a fourth modification example of the structure on the peripheries of the extended portions of the coil conductor seen from an end surface side of the element body excluding external electrodes; 
         FIGS.  12 A to  12 D  illustrate a manufacturing process diagram illustrating an embodiment in which a first molded body is manufactured in a method for manufacturing a coil component; and 
         FIGS.  13 A to  13 D  illustrate a manufacturing process diagram illustrating an embodiment of manufacturing a collective substrate in the method for manufacturing the coil component. 
     
    
    
     DETAILED DESCRIPTION 
     1. Coil Component 
     Hereinafter, a coil component of the present disclosure will be described in detail with reference to the drawings. 
       FIG.  1    is an external perspective view schematically illustrating an embodiment of a coil component of the present disclosure.  FIG.  2    is a transparent perspective view of a magnetic portion in which a coil conductor in the coil component illustrated in  FIG.  1    is buried.  FIG.  3    is a sectional view taken along a line III-III of  FIG.  1    illustrating the coil component according to the present disclosure.  FIG.  4    is a sectional view taken along a line IV-IV of  FIG.  1    illustrating the coil component according to the present disclosure.  FIG.  5    is a transparent perspective view illustrating a first modification example of an element body of the coil component according to the embodiment of the present disclosure.  FIG.  6 A  is a transparent perspective view illustrating a second modification example of the element body of the coil component according to the embodiment of the present disclosure, and  FIG.  6 B  is a transparent perspective view seen in a direction different from  FIG.  6 A .  FIG.  7 A  is a sectional view taken along a line V-V of  FIG.  1    illustrating the coil component according to the present disclosure, and  FIG.  7 B  is an enlarged sectional view of a portion a in  FIG.  7 A . 
     A coil component  10  includes a rectangular parallelepiped element body  12  and external electrodes  40 . 
     (A) Element Body 
     The element body  12  includes a magnetic portion  14  and a coil conductor  16  buried in the magnetic portion  14 . The element body  12  includes a first main surface  12   a  and a second main surface  12   b  facing in a pressing direction x, and a first side surface  12   c  and a second side surface  12   d  facing in a width direction y orthogonal to the pressing direction x, and a first end surface  12   e  and a second end surface  12   f  facing in a length direction z orthogonal to the pressing direction x and the width direction y. A dimension of the element body  12  is not particularly limited. 
     (B) Magnetic Portion 
     The magnetic portion  14  includes metal magnetic particles and a resin material. 
     The resin material is not particularly limited, but, for example, thermosetting resin may be used, or organic materials such as epoxy resin, phenol resin, polyester resin, polyimide resin, and polyolefin resin may be used. The resin material may be only one kind or two or more kinds. 
     The metal magnetic particles preferably include first metal magnetic particles and second metal magnetic particles. 
     The first metal magnetic particles have an average particle diameter of 10 μm or more. The first magnetic particles have an average particle diameter of preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. The average particle diameter of the first metal magnetic particles is set to 10 μm or more, and thus, magnetic characteristics of the magnetic portion are improved. 
     The second metal magnetic particles have an average particle diameter smaller than the average particle diameter of the first metal magnetic particles. The second metal magnetic particles have an average particle diameter of 5 μm or less. As described above, the average particle diameter of the second metal magnetic particles is set to be smaller than the average particle diameter of the first metal magnetic particles, and thus, filling properties of the metal magnetic particles in the magnetic portion  14  are further improved. Accordingly, the magnetic characteristics of the coil component  10  can be improved. 
     Here, the average particle diameter means an average particle diameter D50 (particle diameter corresponding to a cumulative percentage of 50% on a volume basis). The average particle diameter D50 can be measured by, for example, a dynamic light scattering particle size analyzer (UPA manufactured by Nikkiso Co., Ltd.). 
     The first metal magnetic particles and the second metal magnetic particles are not particularly limited, but, for example, iron, cobalt, nickel, gadolinium, or an alloy containing one or more of these metal materials. Preferably, the first metal magnetic particles and the second metal magnetic particles are iron or an iron alloy. The iron alloy is not particularly limited, but, for example, Fe—Si, Fe—Si—Cr, Fe—Ni, and Fe—Si—Al may be used. The first metal magnetic particles and the second metal magnetic particles may be only one kind, or may be two or more kinds. 
     Surfaces of the first metal magnetic particles and the second metal magnetic particles may be covered with an insulating film. The surfaces of the metal magnetic particles are covered with the insulating film, and thus, an internal specific resistance of the magnetic portion  14  can be increased. Since insulation properties are secured by covering the surfaces of the metal magnetic particles with the insulating film, a short-circuit failure with the coil conductor  16  can be suppressed. 
     Silicon oxides, phosphoric acid based glass, and bismuth based glass may be used as the material of the insulating film. In particular, an insulating film made of zinc phosphate glass which is obtained by mechanochemically treating the metal magnetic particles is preferably used. 
     A thickness of the insulating film is not particularly limited, but may be preferably 5 nm or more and 500 nm or less (i.e., from 5 nm to 500 nm), more preferably 5 nm or more and 100 nm or less (i.e., from 5 nm to 100 nm), and even more preferably 10 nm or more and 100 nm or less (i.e., from 10 nm to 100 nm). The thickness of the insulating film is further increased, and thus, the specific resistance of the magnetic portion  14  can be further increased. The thickness of the insulating film is further decreased, and thus, the amount of metal magnetic particles in the magnetic portion  14  can be further increased. Accordingly, the magnetic characteristics of the magnetic portion  14  are improved. 
     A content of the first metal magnetic particles and the second metal magnetic particles in the magnetic portion  14  is preferably 50% by volume or more, more preferably 60% by volume or more, and even more preferably 70% by volume or more with respect to the entire magnetic portion. The content of the first metal magnetic particles and the second metal magnetic particles is set in such ranges, and thus, the magnetic characteristics of the coil component of the present disclosure are improved. The content of the first metal magnetic particles and the second metal magnetic particles in the entire magnetic portion  14  is preferably 99% by volume or less, more preferably 95% by volume or less, and even more preferably 90% by volume or less. The content of the first metal magnetic particles and the second metal magnetic particles is set in such ranges, and thus, the specific resistance of the magnetic portion  14  can be further increased. 
     A region of the surface of the magnetic portion  14  that is adjacent to the coil conductor  16  may be removed. The magnetic portion  14  of the region adjacent to the coil conductor  16  is removed, and thus, a gap between the magnetic portion  14  and the coil conductor  16  is increased. Accordingly, a medium easily enters when barrel plating treatment is performed, and a plating film is formed on a wider area of the coil conductor  16 . Accordingly, the improvement of bonding strength and the reduction of a DC resistance are expected. 
     (C) Coil Conductor 
     The coil conductor  16  includes a winding portion  20  formed by winding a conductive wire containing a conductive material in a coil shape, a first extended portion  22   a  extended to one side of the winding portion  20 , and a second extended portion  22   b  extended to the other side of the winding portion  20 . 
     The winding portion  20  is formed by winding the conductive wire in two stages. The coil conductor  16  is formed by winding a rectangular conductive wire in an α-wound shape. The rectangular conductive wire has a dimension of 15 μm or more and 200 μm or less (i.e., from 15 μm to 200 μm) in the width direction y, and has a dimension of 50 μm or more and 500 μm or less (i.e., from 50 μm to 500 μm) in the pressing direction x. 
     The first extended portion  22   a  is exposed on the first end surface  12   e  of the element body  12 , and a first exposed portion  24   a  is arranged. The second extended portion  22   b  is exposed on the second end surface  12   f  of the element body  12 , and a second exposed portion  24   b  is arranged. 
     Here, the first modification example of the element body  12  of the coil component  10  according to the embodiment of the present disclosure will be illustrated. 
       FIG.  5    is a transparent perspective view illustrating the first modification example of the element body of the coil component according to the embodiment of the present disclosure. 
     An element body  112  includes a magnetic portion  114  and a coil conductor  116  buried in the magnetic portion  114 . The element body  112  includes a first main surface  112   a  and a second main surface  112   b  facing in a height direction x, a first side surface  112   c  and a second side surface  112   d  facing in a width direction y orthogonal to the height direction x, and a first end surface  112   e  and a second end surface  112   f  facing in a length direction z orthogonal to the height direction x and the width direction y. 
     The coil conductor  116  includes a winding portion  120  formed by winding a conductive wire containing a conductive material in a coil shape, a first extended portion  122   a  extended to one side of the winding portion  120 , and a second extended portion  122   b  extended to the other side of the winding portion  120 . 
     The first extended portion  122   a  is extended to and is exposed on the first main surface  112   a  of the element body  112 , and a first exposed portion  124   a  is arranged. The second extended portion  122   b  is exposed on the first main surface  112   a  of the element body  112 , and a second exposed portion  124   b  is arranged. 
     The second modification example of the element body  12  of the coil component  10  according to the embodiment of the present disclosure will be illustrated. 
       FIG.  6 A  is a transparent perspective view illustrating the second modification example of the element body of the coil component according to the embodiment of the present disclosure, and  FIG.  6 B  is a transparent perspective view seen in a direction different from  FIG.  6 A . 
     As illustrated in  FIGS.  6 A and  6 B , an element body  212  includes a magnetic portion  214  and a coil conductor  216  buried in the magnetic portion  214 . The magnetic portion  214  includes a first magnetic portion  214   a  arranged inside the element body  212  and a second magnetic portion  214   b  that covers the first magnetic portion  214   a  and the coil conductor  216 . 
     The element body  212  is formed in a substantially rectangular parallelepiped shape, and includes a first main surface  212   a  and a second main surface  212   b  facing in the height direction x, a first side surface  212   c  and a second side surface  212   d  facing in the width direction y orthogonal to the height direction x, and a first end surface  212   e  and a second end surface  212   f  facing in the length direction z orthogonal to the height direction x and the width direction y. 
     The coil conductor  216  is arranged on one surface side of the first magnetic portion  214   a , and includes a winding portion  220  formed by winding a conductive wire containing a conductive material in a coil shape, a first extended portion  222   a  extended to one side of the winding portion  220 , and a second extended portion  222   b  extended to the other side of the winding portion  220 . The first extended portion  222   a  is extended to and is exposed on the second main surface  212   b  of the element body  212  on the first end surface  212   e  side, and the second extended portion  222   b  is extended to and is exposed on the second main surface  212   b  of the element body  212  on the second end surface  212   f  side. 
     As described above, the first extended portion  222   a  may be formed and arranged on the second main surface  212   b  of the element body  212 , and the second extended portion  222   b  may be formed and arranged on the second main surface  212   b  of the element body  212 . 
     The coil conductor  16  is formed by a conductive wire  16   a  such as a metal wire or a wire. A conductive material of the coil conductor  16  is not particularly limited, but, for example, Ag, Au, Cu, Pd, and Ni may be used. Preferably, the conductive material is copper. The conductive material may be only one kind or two or more kinds. 
     An insulating film  18  is formed on a surface of the conductive wire  16   a  forming the coil conductor  16  by being coated with an insulating material. The conductive wire  16   a  forming the coil conductor  16  is coated with the insulating material, and thus, it is possible to more reliably insulate the wound portions of the coil conductor  16  from each other and the coil conductor  16  and the magnetic portion  14  from each other. 
     The insulating film  18  is not formed on each of the first exposed portion  24   a  and the second exposed portion  24   b  of the conductive wire  16   a  forming the coil conductor  16 . Accordingly, the external electrodes  40  are easily formed by plating treatment. A resistance value in electrical connection between the coil conductor  16  and the external electrodes  40  can be further decreased. 
     The insulating material of the insulating film  18  is not particularly limited, but, for example, polyurethane resin, polyester resin, epoxy resin, and polyamide-imide resin are used. Preferably, the polyamide-imide resin may be used as the insulating film  18 . 
     A thickness of the insulating film  18  is preferably 2 μm or more and 10 μm or less (i.e., from 2 μm to 10 μm). 
     As illustrated in  FIG.  7 B , a plurality of recesses  28  is formed in a surface  26   a   1  and a surface  26   a   2  of the first extended portion  22   a  of the conductive wire  16   a  in the coil conductor  16  on the first main surface  12   a  side and on the second main surface  12   b  side, respectively. The metal magnetic particles  14   a  and the insulating film  18  are arranged in the recesses  28 . Alternatively, only the metal magnetic particles  14   a  are arranged in the recesses  28 . At this time, when the metal magnetic particles  14   a  are arranged in the recesses  28 , the metal magnetic particles  14   a  may or may not penetrate the insulating film  18  formed on the surface  26   a   1  and the surface  26   a   2  of the first extended portion  22   a  on the first main surface  12   a  side and the second main surface  12   b  side, respectively. 
     Similarly, the plurality of recesses  28  is formed on a surface  26   b   1  and a surface  26   b   2  of the second extended portion  22   b  of the conductive wire  16   a  in the coil conductor  16  on the first main surface  12   a  side and the second main surface side, respectively. The metal magnetic particles  14   a  and the insulating film  18  are arranged in the recesses  28 . Alternatively, only the metal magnetic particles  14   a  are arranged in the recesses  28 . At this time, when the metal magnetic particles  14   a  are arranged in the recesses  28 , the metal magnetic particles  14   a  may or may not penetrate the insulating film  18  formed on the surface  26   b   1  and the surface  26   b   2  of the second extended portion  22   b  on the first main surface  12   a  side and the second main surface  12   b  side, respectively. 
     It is preferable that the insulating film  18  be not arranged on the exposed portions (exposed surfaces) of the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  at both the end surfaces  12   e  and  12   f , respectively, of the element body  12 . Accordingly, since the coil conductor  16  and the external electrodes  40  can be directly electrically connected to each other, an electrical connection resistance between the coil conductor  16  and the external electrodes  40  can be reduced. 
     In the metal magnetic particles  14   a  in contact with the external electrodes  40 , an average thickness of the insulating films that are in contact with the external electrodes  40  is preferably smaller than an average thickness of the insulating films that are not in contact with the external electrodes  40 . Accordingly, when the external electrodes  40  are formed by plating, the metal magnetic particles  14   a  positioned on peripheries of the first extended portion  22   a  and the second extended portion  22   b  of the coil conductor  16  exposed on the first end surface  12   e  and the second end surface  12   f , respectively, of the element body  12  can be concentratedly energized, and can be grown by plating. 
     A structure of the peripheries of the exposed surfaces of the extended portions of the coil conductor  16  exposed on the surface of the element body  12  may be a structure to be described below. 
       FIG.  8    is an enlarged sectional view illustrating a first modification example of the structure of the peripheries of the extended portions of the coil conductor  16 . 
     As illustrated in  FIG.  8   , insulating film removed portions  30  which do not include the insulating film  18  toward both the end surfaces  12   e  and  12   f  of the element body  12  are formed at the first extended portion  22   a  and the second extended portion  22   b , respectively, of the coil conductor  16 . The plurality of recesses  28  is formed on the surface  26   a   1  and the surface  26   a   2  of the first extended portion  22   a  of the coil conductor  16  on the first main surface  12   a  side and the second main surface  12   b  side, and the metal magnetic particles  14   a  are arranged in the recesses  28 . Similarly, the plurality of recesses  28  is formed on the surface  26   b   1  and the surface  26   b   2  of the second extended portion  22   b  of the coil conductor  16  on the first main surface  12   a  side and the second main surface  12   b  side, respectively, and the metal magnetic particles  14   a  are arranged in the recesses  28 . Accordingly, the metal magnetic particles  14   a  are directly arranged in the recesses  28  at the insulating film removed portions  30  without penetrating the insulating film  18 . 
     As described above, when the recesses  28  are formed in the surface of the coil conductor  16  by the metal magnetic particles  14   a , since the insulating film  18  acts as a cushion, the insulating film acts in a direction of inhibiting the formation of the recesses  28 . However, the insulating film  18  is removed, and thus, the recesses  28  can be easily formed on the surface of the coil conductor  16 . 
     It is preferable that a part of the external electrodes  40  be arranged at the insulating film removed portions  30 . Accordingly, the bonding strength between the coil conductor  16  and the external electrodes  40  can be further improved. 
       FIG.  9    is an enlarged sectional view illustrating a second modification example of the structure of the peripheries of the extended portions of the coil conductor  16 . 
     Similarly to the first modification example of the structure of the peripheries of the extended portions of the coil conductor  16 , in the second modification example of the peripheries of the extended portions of the coil conductor  16 , the insulating film removed portions  30  which do not include the insulating film  18  toward both the end surfaces  12   e  and  12   f  of the element body  12  are formed at the first extended portion  22   a  and the second extended portion  22   b , respectively, of the coil conductor  16  as illustrated in  FIG.  9   . Minute irregularities  32  are further formed on surfaces of the exposed portions of the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  on both the end surfaces  12   e  and  12   f , respectively, of the element body  12 . Accordingly, since a surface area of the coil conductor  16  and the external electrodes  40  in contact with each other can be increased, the bonding strength between the coil conductor  16  and the external electrode  40  can be further improved. 
       FIG.  10    is an enlarged sectional view illustrating a third modification example of the structure of the peripheries of the extended portions of the coil conductor  16 . 
     Similarly to the first modification example of the structure of the peripheries of the extended portions of the coil conductor  16 , in the third modification of the peripheries of the extended portion of the coil conductor  16 , the insulating film removed portions  30  which do not include the insulating film  18  toward both the end surfaces  12   e  and  12   f  of the element body  12  are formed at the first extended portion  22   a  and the second extended portion  22   b , respectively, of the coil conductor  16  as illustrated in  FIG.  10   . Indented portions  34  are formed in the element body  12  on peripheries of the exposed portions of the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  on both the end surfaces  12   e  and  12   f , respectively, of the element body  12 . The indented portions  34  are formed such that an average distance between the coil conductor  16  and the magnetic portion  14  is increased in a direction in which the first extended portion  22   a  and the second extended portion  22   b  of the coil conductor  16  are extended to both the end surfaces  12   e  and  12   f . Accordingly, since the external electrodes  40  can be arranged such that the indented portions  34  formed on the peripheries of the exposed portions of the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  on both the end surfaces  12   e  and  12   f , respectively, of the element body  12  are filled, the bonding strength between the coil conductor  16  and the external electrodes  40  can be further improved. 
       FIGS.  11 A and  11 B  are enlarged sectional views illustrating a fourth modification example of the structure of the peripheries of the extended portions of the coil conductor  16 . 
     Similarly to the first modification example of the structure of the peripheries of the extended portions of the coil conductor  16 , in the fourth modification example of the peripheries of the extended portions of the coil conductor  16 , the insulating film removed portions  30  which do not include the insulating film  18  toward both the end surfaces  12   e  and  12   f  of the element body  12  are formed at the first extended portion  22   a  and the second extended portion  22   b , respectively, of the coil conductor  16  as illustrated in  FIGS.  11 A and  11 B . Groove portions  36  are formed in both end surfaces  12   e  and  12   f  of the element body  12  and central portions of the surfaces (exposed surfaces) of the exposed portions of the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  on both the end surfaces  12   e  and  12   f , respectively, of the element body  12  in the pressing direction x with a predetermined width in the width direction y. A depth of the groove portion  36  with respect to the element body  12  is preferably 5 μm or more and 100 μm or less (i.e., from 5 μm to 100 μm). Accordingly, since the external electrodes  40  can be arranged such that the groove portions  36  formed in both end surfaces  12   e  and  12   f  of the element body  12  and the surfaces (exposed surfaces) of the exposed portions of the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  on both the end surfaces  12   e  and  12   f , respectively, of the element body  12  are filled, the bonding strength between the coil conductor  16  and the external electrode  40  can be further improved. 
     Although it has been described in  FIGS.  7 A to  11 B  that the structure of the peripheries of the exposed surfaces of the extended portions of the coil conductor  16  exposed on the surface of the element body  12  is the configuration in which the extended portions  22   a  and  22   b  of the coil conductor  16  are extended to and are exposed on both the end surfaces  12   e  and  12   f , respectively, the present disclosure is not limited thereto. The structure of the peripheries of the exposed surfaces on which the extended portions  122   a  and  122   b  are exposed on the first main surface  112   a  side as illustrated in  FIG.  5    or the structure of the peripheries of the exposed surfaces on which the extended portions  222   a  and  222   b  are exposed on the second main surface  212   b  side as illustrated in  FIGS.  6 A and  6 B  may be the same structure. 
     (D) External Electrode 
     The external electrodes  40  are arranged on the first end surface  12   e  side and the second end surface  12   f  side of the element body  12 . The external electrode  40  includes a first external electrode  40   a  and a second external electrode  40   b.    
     The first external electrode  40   a  is arranged on the surface of the first end surface  12   e  of the element body  12 . The first external electrode  40   a  may be formed so as to extend from the first end surface  12   e  and cover a part of each of the first main surface  12   a , the second main surface  12   b , the first side surface  12   c , and the second side surface  12   d , or may be formed so as to extend from the first end surface  12   e  to the second main surface  12   b  and to cover a part of each of the first end surface  12   e  and the second main surface  12   b . As illustrated in  FIG.  5   , when the first extended portion  122   a  of the coil conductor  116  is exposed on the first main surface  112   a , the first external electrode  40   a  may be formed so as to cover a part of the first main surface  112   a . As illustrated in  FIGS.  6 A and  6 B , when the first extended portion  222   a  of the coil conductor  216  is formed and is exposed on the second main surface  212   b , the first external electrode  40   a  may be formed so as to cover a part of the second main surface  212   b . In this case, the first external electrode  40   a  is electrically connected to the first extended portion  22   a  of the coil conductor  16 . 
     The second external electrode  40   b  is arranged on the surface of the second end surface  12   f  of the element body  12 . The second external electrode  40   b  may be formed so as to extend from the second end surface  12   f  and cover a part of each of the first main surface  12   a , the second main surface  12   b , the first side surface  12   c , and the second side surface  12   d , or may be formed so as to extend from the second end surface  12   f  to the second main surface  12   b  and cover a part of each of the second end surface  12   f  and the second main surface  12   b . As illustrated in  FIG.  5   , when the second extended portion  122   b  of the coil conductor  116  is exposed on the first main surface  112   a , the second external electrode  40   b  may be formed so as to cover a part of the first main surface  112   a . As illustrated in  FIGS.  6 A and  6 B , when the second extended portion  222   b  of the coil conductor  216  is formed and is exposed on the second main surface  212   b , the second external electrode  40   b  may be formed so as to cover a part of the second main surface  212   b . In this case, the second external electrode  40   b  is electrically connected to the second extended portion  222   b  of the coil conductor  16 . 
     A thickness of each of the first external electrode  40   a  and the second external electrode  40   b  is not particularly limited, but may be, for example, 1 μm or more and 50 μm or less (i.e., from 1 μm to 50 μm), and preferably 5 μm or more and 20 μm or less (i.e., from 5 μm to 20 μm). 
     The first external electrode  40   a  includes a first base electrode layer  42   a , and a first plated layer  44   a  arranged on a surface of the first base electrode layer  42   a . Similarly, the second external electrode  40   b  includes a second base electrode layer  42   b  and a second plated layer  44   b  arranged on a surface of the second base electrode layer  42   b.    
     The first base electrode layer  42   a  is arranged on the surface of the first end surface  12   e  of the element body  12 . The first base electrode layer  42   a  may be formed so as to extend from the first end surface  12   e  and cover a part of each of the first main surface  12   a , the second main surface  12   b , the first side surface  12   c , and the second side surface  12   d , and may be formed so as to extend from the first end surface  12   e  and cover a part of the second main surfaces  12   b . As illustrated in  FIG.  5   , when the first extended portion  122   a  of the coil conductor  116  is exposed on the first main surface  112   a , the first base electrode layer  42   a  may be formed so as to cover a part of the first main surface  112   a . As illustrated in  FIGS.  6 A and  6 B , when the first extended portion  222   a  of the coil conductor  216  is formed and is exposed on the second main surface  212   b , the first base electrode layer  42   a  may be formed so as to cover a part of the second main surface  212   b.    
     The second base electrode layer  42   b  is arranged on the surface of the second end surface  12   f  of the element body  12 . The second base electrode layer  42   b  may be formed so as to extend from the second end surface  12   f  and cover a part of each of the first main surface  12   a , the second main surface  12   b , the first side surface  12   c , and the second side surface  12   d , or may be formed so as to extend from the second end surface  12   f  and cover apart of the second main surface  12   b . As illustrated in  FIG.  5   , when the second extended portion  122   b  of the coil conductor  116  is exposed on the first main surface  112   a , the second base electrode layer  42   b  may be formed so as to cover a part of the first main surface  112   a . As illustrated in  FIGS.  6 A and  6 B , when the second extended portion  222   b  of the coil conductor  216  is formed and is exposed on the second main surface  212   b , the second base electrode layer  42   b  may be formed so as to cover a part of the second main surface  212   b.    
     The first base electrode layer  42   a  and the second base electrode layer  42   b  are made of a conductive material, preferably one or more metal materials selected from Au, Ag, Pd, Ni, and Cu. The first base electrode layer  42   a  and the second base electrode layer  42   b  may be formed as plating electrodes, or may be formed by applying a conductor paste or sputtering. 
     An average thickness of the first base electrode layer  42   a  and the second base electrode layer  42   b  is, for example, 10 μm. 
     The first plated layer  44   a  is arranged so as to cover the first base electrode layer  42   a . Specifically, the first plated layer  44   a  may be arranged so as to cover the first base electrode layer  42   a  arranged on the first end surface  12   e , may be arranged so as to cover the surface of the first base electrode layer  42   a  arranged on the first main surface  12   a , the second main surface  12   b , the first side surface  12   c , and the second side surface  12   d  so as to extend from the first end surface  12   e , or may be arranged so as to cover the first base electrode layer  42   a  arranged so as to extend from the first end surface  12   e  and cover a part of the second main surface  12   b . As illustrated in  FIG.  5   , when the first extended portion  122   a  of the coil conductor  116  is exposed on the first main surface  112   a , the first plated layer  44   a  may be formed so as to cover the first base electrode layer  42   a  arranged on the first main surface  112   a . As illustrated in  FIGS.  6 A and  6 B , when the first extended portion  222   a  of the coil conductor  216  is formed and is directly extended to the second main surface  212   b , the first plated layer  44   a  may be formed so as to cover the first base electrode layer  42   a  arranged on the second main surface  212   b.    
     The second plated layer  44   b  is arranged so as to cover the second base electrode layer  42   b . Specifically, the second plated layer  44   b  may be arranged so as to cover the second base electrode layer  42   b  arranged on the second end surface  12   f , may be arranged so as to cover the surface of the second base electrode layer  42   b  arranged on the first main surface  12   a , the second main surface  12   b , the first side surface  12   c , and the second side surface  12   d  so as to extend from the second end surface  12   f , or may be arranged so as to cover the second base electrode layer  42   b  arranged so as to extend from the second end surface  12   f  and cover a part of the second main surface  12   b . As illustrated in  FIG.  5   , when the second extended portion  122   b  of the coil conductor  116  is exposed on the first main surface  112   a , the second plated layer  44   b  may be formed so as to cover the second base electrode layer  42   b  arranged on the first main surface  112   a . As illustrated in  FIGS.  6 A and  6 B , when the second extended portion  222   b  of the coil conductor  216  is formed and is directly extended to the second main surface  212   b , the second plated layer  44   b  may be formed so as to cover the second base electrode layer  42   b  arranged on the second main surface  212   b.    
     Metal materials of the first plated layer  44   a  and the second plated layer  44   b  include, for example, at least one selected from Cu, Ni, Ag, Sn, Pd, an Ag—Pd alloy, or Au. 
     The first plated layer  44   a  and the second plated layer  44   b  may be formed in multiple layers. 
     The first plated layer  44   a  has a two-layer structure of a first Ni plated layer  46   a  and a first Sn plated layer  48   a  on a surface of the first Ni plated layer  46   a . The second plated layer  44   b  has a two-layer structure of a second Ni plated layer  46   b  and a second Sn plated layer  48   b  on a surface of the second Ni plated layer  46   b.    
     An average thickness of the first Ni plated layer  46   a  and the second Ni plated layer  46   b  is, for example, 5 μm. 
     An average thickness of the first Sn plated layer  48   a  and the second Sn plated layer  48   b  is, for example, 10 μm. 
     The first external electrode  40   a  and the second external electrode  40   b  may have the following configurations. 
     For example, the first base electrode layer  42   a  and the second base electrode layer  42   b  may be resin electrodes containing Ag, or may be formed by an Ag sputtered layer by sputtering, a Cu sputtered layer, or a Ti sputtered layer. When the first base electrode layer  42   a  and the second base electrode layer  42   b  are Ag-containing resin electrodes, glass frit may be contained. When the first base electrode layer  42   a  and the second base electrode layer  42   b  are formed by sputtering, a Cu sputtered layer may be formed on a Ti sputtered layer. 
     The outermost layers of the first plated layer  44   a  and the second plated layer  44   b  may be formed of only the Sn plated layers  48   a  and  48   b , respectively. 
     The Ag plated layer or the Ni plated layer may be formed on the element body  12  without forming the first base electrode layer  42   a  and the second base electrode layer  42   b.    
     (E) Protective Layer 
     In the present embodiment, a protective layer  50  is formed on the surface of the element body  12  excluding the first exposed portion  24   a  exposed on the first end surface  12   e  of the element body  12  and the second exposed portion  24   b  exposed on the second end surface  12   f . The protective layer  50  is made of, for example, a resin material having high electric insulation such as acrylic resin, epoxy resin, and polyimide. Although the protective layer  50  is provided, the present disclosure is not limited thereto, and may not necessarily be provided. 
     When a dimension of the coil component  10  in the length direction z is an L dimension, the L dimension is preferably 1.0 mm or more and 12.0 mm or less (i.e., from 1.0 mm to 12.0 mm). When a dimension of the coil component  10  in the width direction y is a W dimension, the W dimension is preferably 0.5 mm or more and 12.0 mm or less (i.e., from 0.5 mm to 12.0 mm). When a dimension of the coil component  10  in the pressing direction x is a T dimension, the T dimension is preferably 0.5 mm or more and 6.0 mm or less (i.e., from 0.5 mm to 6.0 mm). 
     2. Method for Manufacturing Coil Component 
     Next, a method for manufacturing the coil component will be described. 
     (A) Preparation of Metal Magnetic Particles 
     First, the metal magnetic particles are prepared. Here, the metal magnetic particles are not particularly limited, but, for example, Fe-based soft magnetic powders such as α-Fe, Fe—Si, Fe—Si—Cr, Fe—Si—Al, Fe—Ni, and Fe—Co may be used. A non-crystalline material having good soft magnetic properties is preferably used as the material form of the metal magnetic particles, but the present disclosure is not particularly limited, and may be a crystalline material. 
     The average particle diameter of the metal magnetic particles is not particularly limited, but two or more kinds of metal magnetic particles having different average particle diameters are preferably used. That is, the metal magnetic particles are dispersed in the resin material. Accordingly, from the viewpoint of improving filling efficiency of the metal magnetic particles, for example, the metal magnetic particles having different average particle diameters such as the first metal magnetic particles having an average particle diameter of 10 μm or more and 40 μm or less (i.e., from 10 μm to 40 μm) and the second metal magnetic particles having an average particle diameter of 1 μm or more and 20 μm or less (i.e., from 1 μm to 20 μm) are preferably used. 
     (B) Formation of Insulating Film 
     Next, the surface of the metal magnetic particles is coated with the insulating film. Here, when the insulating film is formed by a mechanical method, the surface of a magnetic powder can be coated with the insulating film by inputting the metal magnetic particles and the insulating material powder into a rotating container and compounding the particles by mechanochemical treatment. 
     (C) Production of Magnetic Sheet 
     Next, the resin material is prepared. The resin material is not particularly limited, and for example, epoxy resin, phenol resin, polyester resin, polyimide resin, and polyolefin resin can be used. 
     Subsequently, a magnetic sheet having a thickness of 50 μm or more and 300 μm or less (i.e., from 50 μm to 300 μm) is produced by mixing the metal magnetic particles coated with the insulating film and other filler components (glass material, ceramic powder, and ferrite powder) with the resin material, forming the mixture into a slurry, performing molding by using a doctor blade method, drying the molded filler, and dispersing the filler components into the resin material. 
     (D) Production of Collective Substrate 
     Next, the α-wounded coil conductor  16  formed by winding the rectangular conductive wire coated with the insulating film  18  is prepared by using Cu as the conductive wire. If necessary, the insulating film  18  in a region of 50 μm from an end of the coil conductor  16  is removed with a nipper-shaped clip. Accordingly, the insulating film removed portion  30  that is a portion not covered with the insulating film  18  is formed in an annular shape with an extending direction of the coil conductor  16  as a central axis. The insulating film  18  can be removed by being burned off by heating, or may be dissolved by a chemical solution or a laser. At this time, the recesses  28  may be provided in advance in the first extended portion  22   a  and the second extended portion  22   b  of the coil conductor  16 . 
     Subsequently, the element body  12  in which the coil conductor  16  is buried is manufactured. 
       FIGS.  12 A to  12 D  illustrate a manufacturing process diagram illustrating an embodiment of manufacturing a first molded body in the method for manufacturing the coil component.  FIGS.  13 A to  13 D  illustrate a manufacturing process diagram illustrating an embodiment of manufacturing a collective substrate in the method for manufacturing the coil component. 
     First, as illustrated in  FIG.  12 A , a first mold  60  is prepared, and the coil conductors  16  are arranged in a matrix on the first mold  60 . 
     Next, a first magnetic sheet  70   a  of the mixture containing the first metal magnetic particles, the second metal magnetic particles, and the resin material is layered on the coil conductors  16  as illustrated in  FIG.  12 B , and a second mold  62  is arranged on an upper surface side of the first magnetic sheet  70   a  as illustrated in  FIG.  12 C . As illustrated in  FIG.  12 D , primary press molding is performed on the first magnetic sheet  70   a  while sandwiching the first magnetic sheet  70   a  between the coil conductors  16  on the first mold  60 , and the second mold  62 . Due to this primary press molding, a first molded body  72  is produced by burying at least a part of the coil conductors  16  in the sheet and filling the coil conductors  16  with the mixture. 
     Subsequently, as illustrated in  FIG.  13 A , the first molded body  72  is arranged on the first mold  60  by separating the first molded body  72  in which the coil conductors  16  obtained by the primary press molding is buried from the second mold  62  and turning over the first molded body  72 . Another second magnetic sheet  70   b  is layered on the surface on which the coil conductors  16  are exposed. Subsequently, as illustrated in  FIG.  13 B , a third mold  64  is arranged on an upper surface side of the second magnetic sheet  70   b . As illustrated in  FIG.  13 C , secondary pressing is performed on the second magnetic sheet  70   b  while sandwiching the second magnetic sheet  70   b  between the first molded body  72  on the first mold  60  and the third mold  64 . 
     Protrusions  64   a  and  64   b  are arranged on the third mold  64  at portions corresponding to the extended portions. In the secondary pressing, the protrusions  64   a  and  64   b  can apply a pressure to the peripheries of the extended portions with the second magnetic sheet interposed therebetween. Accordingly, in the secondary pressing illustrated in  FIG.  13 C , the metal magnetic particles  14   a  and the insulating film  18  are buried in the surfaces of the first extended portion  22   a  and the second extended portion  22   b  of the coil conductor  16 . 
     In the secondary pressing, the metal magnetic particles can be arranged so as to be buried by adjusting the pressure during pressurization or providing the recesses on the surfaces of the extended portions in advance. 
     Subsequently, after the secondary pressing, the collective substrate (second molded body)  74  in which all the coil conductors  16  are buried in the first magnetic sheet  70   a  and the second magnetic sheet  70   b  by separating the third mold  64  is produced as illustrated in  FIG.  13 D . 
     (E) Production of Element Body 
     Subsequently, after the collective substrate  74  is produced by separating the first mold  60  and the third mold  64  as illustrated in  FIG.  13 D , the collective substrate  74  is cut along a cutting line by using a cutting tool such as a dicer, and is divided into individual elements. Accordingly, the element body  12  in which the coil conductors  16  are buried such that the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  are exposed from both the end surfaces of the element body  12  is produced. The division of the collective substrate  74  into the element bodies  12  can be performed by using a dicing blade, various laser devices, dicers, various blades, and molds. In a preferred aspect, a cut surface of each element body  12  is barrel polished. 
     Subsequently, the protective layer  50  is formed on the entire surface of the element body obtained above. The protective layer  50  can be formed by electrodeposition coating, a spray method, or a dip method. 
     The insulating films  18  on the peripheries of the coil conductor  16  at which the first exposed portion  24   a  and the second exposed portion  24   b  are arranged, the metal magnetic particles  14   a , the insulating film coated on the metal magnetic particles  14   a , and the protective layer  50  are removed and the metal magnetic particles  14   a  are melted by irradiating the periphery of the element body  12  coated with the protective layer  50  obtained above at which the first exposed portion  24   a  and the second exposed portion  24   b  of the coil conductor  16  are arranged with laser. The protective layer  50  can be removed by blasting or polishing other than the laser irradiation. 
     (F) Formation of External Electrode 
     Subsequently, the first external electrode  40   a  is formed on the first end surface  12   e  of the element body  12 , and the second external electrode  40   b  is formed on the second end surface  12   f  of the element body  12 . 
     First, the base electrode layer is formed by performing Cu plating on the element body  12  by electrolytic barrel plating. Subsequently, the external electrode  40  is formed by forming the Ni plated layer on the surface of the base electrode layer by Ni plating and further forming the Sn plated layer by Sn plating. Accordingly, the first exposed portion  24   a  of the coil conductor  16  is electrically connected to the first external electrode  40   a , and the second exposed portion  24   b  of the coil conductor  16  is electrically connected to the second external electrode  40   b.    
     The coil component  10  is manufactured as described above. 
     The metal magnetic particles  14   a  of the magnetic portion  14  may be arranged in the recesses formed in the surface of the conductive wire  16   a  of the coil conductor  16  at the winding portion  20  inside the element body  12 . 
     The metal magnetic particles  14   a  of the magnetic portion  14  are arranged in the recesses  28  formed on the surface of the first exposed portion  24   a  and the surface of the second exposed portion  24   b  of the coil conductor  16  from which the insulating film  18  is removed, and thus, an anchor effect due to the metal magnetic particles  14   a  occurs. Accordingly, the bonding strength between the magnetic portion  14  and the coil conductor  16  can be improved. 
     Since the coil conductor  16  and the external electrode  40  are directly bonded, the contact resistance can be reduced. 
     As described above, although the embodiment of the present disclosure is disclosed in the above description, the present disclosure is not limited thereto. 
     That is, various changes of the mechanism, shape, material, quantity, position, and arrangement can be implemented on the embodiment described above without departing from the technical idea and scope of the present disclosure, and are included in the present disclosure.