Patent Publication Number: US-9424981-B2

Title: Inductor element

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to inductor elements, and particularly relates to an inductor element that is applied as an antenna coil for near field communication. 
     2. Description of the Related Art 
     An example of this type of element is disclosed in Patent Document 1. According to this related art, an antenna coil includes a magnetic core and a coil that is wound therearound in the longitudinal direction of the magnetic core. The antenna coil is fabricated by winding, around a ferrite core, a resin film that is made of polyimide or the like and has a coil pattern printed thereon. 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-35464 
     BRIEF SUMMARY OF THE INVENTION 
     However, according to the related art, a resin film is simply wound around a ferrite core, and thus the operation performance of the element is limited. 
     Accordingly, a major object of the present invention is to provide an inductor element that has enhanced operation performance. 
     An inductor element according to the present invention is an inductor element that includes a multilayer body including three or more sheets that are stacked one on top of another, each of the sheets having a principal surface provided with a plurality of linear conductors; and a plurality of via-hole conductors or side-surface conductors that are disposed with the multilayer body so as to connect the plurality of linear conductors to one another and form an inductor. The plurality of linear conductors have a pattern that is common among at least two sheets adjacent to each other in a stacking direction. 
     Preferably, the three or more sheets include one or more first sheets and a plurality of second sheets (SH 3  and SH 4 ), each of the first sheets having a principal surface provided with a plurality of first linear conductors that are arranged at a predetermined interval in a first direction and that extend in a direction having a first angle with respect to the first direction, each of the second sheets having a principal surface provided with a plurality of second linear conductors that are arranged at the predetermined interval in a second direction and that extend in a direction having a second angle with respect to the second direction. 
     In a certain aspect, the first direction and the second direction match each other and the first sheets and the second sheets are stacked such that sheets of the same type are stacked one on top of another. Accordingly, the first linear conductors and the second linear conductors are alternately arranged along the principal surfaces when viewed from the stacking direction. A difference between a distance in the first direction from one end to another end of each of the first linear conductors and a distance in the second direction from one end to another end of each of the second linear conductors corresponds to the predetermined interval. 
     In another aspect, the one or more first sheets and the plurality of second sheets disposed between an inner side of the first linear conductors and an inner side of the second linear conductors are magnetic sheets. 
     In still another aspect, the one or more first sheets and the plurality of second sheets that are different from the one or more magnetic sheets disposed between an inner side of the first linear conductors and an inner side of the second linear conductors are nonmagnetic sheets. 
     According to the present invention, with a pattern of a plurality of linear conductors being common among at least two sheets, a plurality of protrusions having a pattern corresponding to this pattern are formed on a principal surface of an inductor element. Accordingly, the heat dissipation performance is enhanced. Further, with sheets provided with a plurality of linear conductors having a common pattern being adjacent to each other in a stacking direction, the plurality of linear conductors arranged in the stacking direction are connected in parallel to each other. Accordingly, DC resistance components of the inductor element are reduced, and the operation performance of the element is enhanced. 
     The above-described object and other objects, features, and advantages of the present invention will become more apparent from the detailed description of an embodiment that will be given with reference to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an exploded view of an inductor element according to this embodiment. 
         FIG. 2A  is a plan view illustrating an example of a nonmagnetic sheet SH 1   a  or SH 1   b  included in the inductor element,  FIG. 2B  is a plan view illustrating an example of a magnetic sheet SH 3  included in the inductor element, and  FIG. 2C  is a plan view illustrating an example of a nonmagnetic sheet SH 4  included in the inductor element. 
         FIG. 3  is a perspective view illustrating an appearance of the inductor element according to this embodiment. 
         FIG. 4  is a diagram illustrating the structure of an A-A cross section of the inductor element illustrated in  FIG. 3 . 
         FIG. 5A  is a diagram illustrating a part of a manufacturing process of the nonmagnetic sheet SH 1   a , and  FIG. 5B  is a diagram illustrating another part of the manufacturing process of the nonmagnetic sheet SH 1   a.    
         FIG. 6A  is a diagram illustrating another part of the manufacturing process of the nonmagnetic sheet SH 1   a , and  FIG. 6B  is a diagram illustrating still another part of the manufacturing process of the nonmagnetic sheet SH 1   a.    
         FIG. 7A  is a diagram illustrating a part of a manufacturing process of the nonmagnetic sheet SH 1   b , and  FIG. 7B  is a diagram illustrating another part of the manufacturing process of the nonmagnetic sheet SH 1   b.    
         FIG. 8A  is a diagram illustrating another part of the manufacturing process of the nonmagnetic sheet SH 1   b , and  FIG. 8B  is a diagram illustrating still another part of the manufacturing process of the nonmagnetic sheet SH 1   b.    
         FIG. 9A  is a diagram illustrating a part of a manufacturing process of a magnetic sheet SH 2 ,  FIG. 9B  is a diagram illustrating another part of the manufacturing process of the magnetic sheet SH 2 , and  FIG. 9C  is a diagram illustrating still another part of the manufacturing process of the magnetic sheet SH 2 . 
         FIG. 10A  is a diagram illustrating a part of a manufacturing process of the magnetic sheet SH 3 , and  FIG. 10B  is a diagram illustrating another part of the manufacturing process of the magnetic sheet SH 3 . 
         FIG. 11A  is a diagram illustrating another part of the manufacturing process of the magnetic sheet SH 3 , and  FIG. 11B  is a diagram illustrating still another part of the manufacturing process of the magnetic sheet SH 3 . 
         FIG. 12A  is a diagram illustrating a part of a manufacturing process of the nonmagnetic sheet SH 4 , and  FIG. 12B  is a diagram illustrating another part of the manufacturing process of the nonmagnetic sheet SH 4 . 
         FIG. 13A  is a diagram illustrating another part of the manufacturing process of the nonmagnetic sheet SH 4 , and  FIG. 13B  is a diagram illustrating still another part of the manufacturing process of the nonmagnetic sheet SH 4 . 
         FIG. 14A  is a diagram illustrating a part of a manufacturing process of the inductor element,  FIG. 14B  is a diagram illustrating another part of the manufacturing process of the inductor element, and  FIG. 14C  is a diagram illustrating still another part of the manufacturing process of the inductor element. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a coil antenna element  10  according to this embodiment includes nonmagnetic sheets SH 0 , SH 1   a , SH 1   b , SH 4 , and SH 5 , and magnetic sheets SH 2  and SH 3 , each of which has rectangular principal surfaces. These sheets are stacked in order of “SH 0 ”, “SH 1   a ”, “SH 1   b ”, “SH 2 ”, “SH 3 ”, “SH 4 ”, and “SH 5 ”, and thereby a rectangular parallelepiped multilayer body  12  is fabricated. A long side and a short side of a rectangle that forms a principal surface of the multilayer body  12  extend along an X-axis and a Y-axis, respectively, and a thickness of the multilayer body  12  increases along a Z-axis. A lower surface of the multilayer body  12  is provided with conductor terminals  14   a  and  14   b , which are located at both ends in the X-axis direction. 
     The sheets SH 0 , SH 1   a , SH 1   b , and SH 2  to SH 5  have principal surfaces of the same size. The sheets SH 0 , SH 1   a , SH 1   b , SH 4 , and SH 5  are made of a nonmagnetic ferrite, whereas the sheets SH 2  and SH 3  are made of a magnetic ferrite. Further, one principal surface and the other principal surface of the multilayer body  12  or the sheets SH 0 , SH 1   a , SH 1   b , and SH 2  to SH 5  are respectively referred to as an “upper surface” and a “lower surface” if necessary. 
     As illustrated in  FIG. 2A , a plurality of linear conductors  16  are disposed on the upper surfaces of the nonmagnetic sheets SH 1   a  and SH 1   b . Also, as illustrated in  FIG. 2B , a plurality of linear conductors  18   a  are disposed on the upper surface of the magnetic sheet SH 3 . Further, as illustrated in  FIG. 2C , a plurality of linear conductors  18   b  are disposed on the upper surface of the nonmagnetic sheet SH 4 . No linear conductors exist on the upper surface of the magnetic sheet SH 2 , and a magnetic body is present over the entire upper surface. Likewise, no linear conductors exist on the upper surfaces of the nonmagnetic sheets SH 0  and SH 5 , and a nonmagnetic body is present over the entire upper surfaces. 
     The linear conductors  16  extend in a slanting direction with respect to the Y-axis and are arranged at an interval of a distance D 1  in the X-axis direction. Both ends in the length direction of each linear conductor  16  reach both edges in the Y-axis direction of the upper surface of the nonmagnetic sheet SH 1   a  or SH 1   b . The two linear conductors  16  on both end sides in the X-axis direction are located on inner sides of both ends in the X-axis direction of the upper surface of the nonmagnetic sheet SH 1   a  or SH 1   b.    
     The linear conductors  18   a  extend along the Y-axis and are arranged at an interval of the distance D 1  in the X-axis direction. Both ends in the length direction of each linear conductor  18   a  reach both edges in the Y-axis direction of the upper surface of the magnetic sheet SH 3 . The two linear conductors  18   a  on both end sides in the X-axis direction are located on inner sides of both ends in the X-axis direction of the upper surface of the magnetic sheet SH 3 . 
     The linear conductors  18   b  extend along the Y-axis and are arranged at an interval of the distance D 1  in the X-axis direction. Both ends in the length direction of each linear conductor  18   b  reach both edges in the Y-axis direction of the upper surface of the nonmagnetic sheet SH 4 . The two linear conductors  18   b  on both end sides in the X-axis direction are located on inner sides of both ends in the X-axis direction of the upper surface of the nonmagnetic sheet SH 4 . 
     The arrangement of the linear conductors  18   b  on the nonmagnetic sheet SH 4  matches the arrangement of the linear conductors  18   b  on the magnetic sheet SH 3 . Thus, the linear conductors  18   b  completely overlap the linear conductors  18   a  when viewed from the Z-axis direction. 
     In contrast, regarding the nonmagnetic sheet SH 1   a  or SH 1   b , a distance in the X-axis direction from one end to the other end of each linear conductor  16  corresponds to “D 1 ”. In other words, the difference between the distance in the X-axis direction from one end to the other end of each linear conductor  16  and a distance in the X-axis direction from one end to the other end of each linear conductor  18   a  (or  18   b ) corresponds to “D 1 ”. 
     The position of one end of each linear conductor  16  is adjusted to a position that overlaps one end of a corresponding one of the linear conductors  18   a  or  18   b  when viewed from the Z-axis direction. The number of linear conductors  16  is smaller by one than the number of linear conductors  18   a  (=the number of linear conductors  18   b ). 
     Thus, when viewed from the Z-axis direction, the most part of each linear conductor  16  is sandwiched between two adjacent linear conductors  18   a  (or two adjacent linear conductors  18   b ). That is, when viewed from the Z-axis direction, the linear conductors  16  and  18   a  (or  18   b ) are alternately arranged in the X-axis direction. 
     On the upper surfaces of the nonmagnetic sheets SH 1   a  and SH 1   b , plate-like conductors  20   a  and  20   b  are also disposed. The plate-like conductor  20   a  is disposed at a position that is a little toward the negative side of the positive end in the X-axis direction and at the positive edge in the Y-axis direction. The plate-like conductor  20   b  is disposed at a position that is a little toward the positive side of the negative end in the X-axis direction and at the negative edge in the Y-axis direction. A distance from the plate-like conductor  20   a  to one end of the linear conductor  16  that is at the most positive side in the X-axis direction corresponds to “D 1 ”, and also a distance from the plate-like conductor  20   b  to the other end of the linear conductor  16  that is at the most negative side in the X-axis direction corresponds to “D 1 ”. 
     As illustrated in  FIG. 1 , the plate-like conductors  20   a  disposed on the individual nonmagnetic sheets SH 1   a  and SH 1   b  are connected to the conductor terminal  14   a  via a via-hole conductor  22   a . Also, the plate-like conductors  20   b  disposed on the individual nonmagnetic sheets SH 1   a  and SH 1   b  are connected to the conductor terminal  14   b  via a via-hole conductor  22   b.    
     Referring to  FIG. 3 , a plurality of via-hole conductors (or side-surface conductors)  24   a  that extend in the Z-axis direction are disposed on a side surface on the positive side in the Y-axis direction of the multilayer body  12 . Also, a plurality of via-hole conductors (or side-surface conductors)  24   b  that extend in the Z-axis direction are disposed on a side surface on the negative side in the Y-axis direction of the multilayer body  12 . 
     The number of via-hole conductors  24   a  is the same as the number of linear conductors  18   a  (or linear conductors  18   b ), and the number of via-hole conductors  24   b  is the same as the number of linear conductors  18   a  (or linear conductors  18   b ). The individual via-hole conductors  24   a  and  24   b  are arranged at an interval of the distance D 1  in the X-axis direction. Further, the via-hole conductor  24   a  that is on the most positive side in the X-axis direction is connected to the plate-like conductors  20   a , and the via-hole conductor  24   b  that is on the most negative side in the X-axis direction is connected to the plate-like conductors  20   b.    
     Accordingly, the linear conductors  16  disposed on the nonmagnetic sheet SH 1   b , the linear conductors  18   a  disposed on the magnetic sheet SH 3 , and the via-hole conductors  24   a  and  24   b  form a coil conductor (winding body). A magnetic body is disposed on an inner side of the coil conductor. Further, two linear conductors  16  that overlap each other when viewed from the Z-axis direction are connected in parallel to each other with a nonmagnetic body interposed therebetween. Also, two linear conductors  18   a  and  18   b  that overlap each other when viewed from the Z-axis direction are connected in parallel to each other with a nonmagnetic body interposed therebetween. 
     Referring to  FIG. 4 , a plurality of protrusions CN 1  are disposed on the upper surface of the inductor element  10 . The protrusions CN 1  are arranged at an interval of the distance D 1  in the X-axis direction and extend along the Y-axis. Also, a plurality of protrusions CN 2  are disposed on the lower surface of the inductor element  10 . The protrusions CN 2  are arranged at an interval of the distance D 1  in the X-axis direction and extend in a slanting direction with respect to the Y-axis. 
     The protrusions CN 1  and CN 2  are formed as a result of stacking a plurality of sheets having a common conductor pattern. The protrusions CN 1  and CN 2  are formed at the time when firing (described below) is completed. As a result of forming the protrusions CN 1  and CN 2  in this way, the heat dissipation performance of the inductor element  10  is enhanced. Further, as a result of connecting in parallel two linear conductors  16  (or  18   a  and  18   b ) that overlap each other when viewed from the Z-axis direction, DC resistance components of the inductor element  10  are reduced. Accordingly, the operation performance of the inductor element  10  can be enhanced. 
     The nonmagnetic sheet SH 1   a  is fabricated in the manner illustrated in  FIG. 5A ,  FIG. 5B ,  FIG. 6A , and  FIG. 6B . First, a ceramic green sheet made of a nonmagnetic ferrite material is prepared as a mother sheet BS 1   a  (see  FIG. 5A ). Here, a plurality of broken lines extending in the X-axis direction and the Y-axis direction indicate cutting positions. 
     Subsequently, a plurality of through-holes HL 1   a  are formed at positions near intersections of the broken lines in the mother sheet BS 1  (see  FIG. 5B ), and the through-holes HL 1   a  are filled with a conductive paste PS 1   a  (see  FIG. 6A ). The conductive paste PS 1   a  that has filled the through-holes HL 1   a  forms the via-hole conductor  22   a  or  22   b.    
     After filling with the conductive paste PS 1   a  has been completed, a coil pattern CP 1   a  that forms the linear conductors  16  and the plate-like conductors  20   a  and  20   b  is printed on one principal surface of the mother sheet BS 1   a  (see  FIG. 6B ). 
     The nonmagnetic sheet SH 0  is fabricated by forming through-holes that are the same as the through-holes HL 1   a  illustrated in  FIG. 5B  in a mother board, filling the through-holes with a conductive paste, and printing the conductor terminals  14   a  and  14   b  on the lower surface of the mother board. 
     The nonmagnetic sheet SH 1   b  is fabricated in the manner illustrated in  FIG. 7A ,  FIG. 7B ,  FIG. 8A , and  FIG. 8B . First, a ceramic green sheet made of a nonmagnetic ferrite material is prepared as a mother sheet BS 1   b  (see  FIG. 7A ). Here, a plurality of broken lines extending in the X-axis direction and the Y-axis direction indicate cutting positions. 
     Subsequently, a plurality of through-holes HL 1   b _ 1  are formed near intersections of the broken lines in the mother sheet BS 1   b , and a plurality of through-holes HL 1   b _ 2  are formed along the broken lines extending in the X-axis direction in the mother sheet BS 1   b  (see  FIG. 7B ). The through-holes HL 1   b _ 1  are filled with a conductive paste PS 1   b _ 1 , and the through-holes HL 1   b _ 2  are filled with a conductive paste PS 1   b _ 2  (see  FIG. 8A ). The conductive paste PS 1   b _ 1  forms the via-hole conductor  22   a  or  22   b , and the conductive paste PS 1   b _ 2  forms the via-hole conductors  24   a  or  24   b.    
     After filling with the conductive paste PS 1   b _ 1  or PS 1   b _ 2  has been completed, a coil pattern CP 1   b  that forms the linear conductors  16  and the plate-like conductors  20   a  and  20   b  is printed on one principal surface of the mother sheet BS 1   b  (see  FIG. 8B ). 
     The magnetic sheet SH 2  is fabricated in the manner illustrated in  FIG. 9A  to  FIG. 9C . First, a ceramic green sheet made of a magnetic ferrite material is prepared as a mother sheet BS 2  (see  FIG. 9A ). Here, a plurality of broken lines extending in the X-axis direction and the Y-axis direction indicate cutting positions. Subsequently, a plurality of through-holes HL 2  are formed along the broken lines extending in the X-axis direction in the mother sheet BS 2  (see  FIG. 9B ), and the through-holes HL 2  are filled with a conductive paste PS 2  that forms the via-hole conductors  24   a  or  24   b  (see  FIG. 9C ). 
     The magnetic sheet SH 3  is fabricated in the manner illustrated in  FIG. 10A ,  FIG. 10B ,  FIG. 11A , and  FIG. 11B . First, a ceramic green sheet made of a magnetic ferrite material is prepared as a mother sheet BS 3  (see  FIG. 10A ). Here, a plurality of broken lines extending in the X-axis direction and the Y-axis direction indicate cutting positions. 
     Subsequently, a plurality of through-holes HL 3  are formed along the broken lines extending in the X-axis direction in the mother sheet BS 3  (see  FIG. 10B ), and the through-holes HL 3  are filled with a conductive paste PS 3  that forms the via-hole conductors  24   a  or  24   b  (see  FIG. 11A ). After filling with the conductive paste PS 3  has been completed, a coil pattern CP 3  that forms the linear conductors  18   a  is printed on one principal surface of the mother sheet BS 3  (see  FIG. 11B ). 
     The nonmagnetic sheet SH 4  is fabricated in the manner illustrated in  FIG. 12A ,  FIG. 12B ,  FIG. 13A , and  FIG. 13B . First, a ceramic green sheet made of a nonmagnetic ferrite material is prepared as a mother sheet BS 4  (see  FIG. 12A ). Here, a plurality of broken lines extending in the X-axis direction and the Y-axis direction indicate cutting positions. 
     Subsequently, a plurality of through-holes HL 4  are formed along the broken lines extending in the X-axis direction in the mother sheet BS 4  (see  FIG. 12B ), and the through-holes HL 4  are filled with a conductive paste PS 4  that forms the via-hole conductors  24   a  or  24   b  (see  FIG. 13A ). After filling with the conductive paste PS 4  has been completed, a coil pattern CP 4  that forms the linear conductors  18   b  is printed on one principal surface of the mother sheet BS 4  (see  FIG. 13B ). 
     The mother sheets BS 1   a , BS 1   b , and BS 2  to BS 4  that have undergone the above-described steps, a mother sheet BS 0  corresponding to the nonmagnetic sheet SH 0 , and a mother sheet BS 5  corresponding to the nonmagnetic sheet SH 5  are press-bonded to one another with being stacked in the manner illustrated in  FIG. 14A . According to  FIG. 14A , the mother sheets BS 0 , BS 1   a , BS 1   b , and BS 2  to BS 5  are stacked in this order. At this time, the stacking positions of the individual sheets are adjusted so that the broken lines assigned to the individual sheets overlap one another when viewed from the Z-axis direction. 
     The multilayer body obtained through the press-bonding is cut along the above-described broken lines into individual pieces before firing (see  FIG. 14B ). After that, the individual pieces undergo a series of processes including barrel polishing, firing, and plating (see  FIG. 14C ), and accordingly the inductor element  10  is completed. 
     As is understood from the description given above, the multilayer body  12  includes the nonmagnetic sheets SH 1   a  and SH 1   b  each having the upper surface provided with the plurality of linear conductors  16 ; the magnetic sheet SH 3  having the upper surface provided with the plurality of linear conductors  18   a ; and the nonmagnetic sheet SH 4  having the upper surface provided with the plurality of linear conductors  18   b , which are stacked one on top of another. The plurality of via-hole conductors  24   a  and  24   b  are disposed in the multilayer body  12  so as to connect these linear conductors to one another and form an inductor. Here, the plurality of linear conductors have a pattern that is common among at least two sheets adjacent to each other in the stacking direction. 
     With a pattern of a plurality of linear conductors being common among at least two sheets, the plurality of protrusions CN 1  and CN 2  having a pattern corresponding to this pattern are formed on the principal surfaces of the inductor element  10 . Accordingly, the heat dissipation performance is enhanced. Further, with sheets provided with a plurality of linear conductors having a common pattern being adjacent to each other in the stacking direction, a plurality of linear conductors arranged in the stacking direction are connected in parallel to each other. Accordingly, DC resistance components of the inductor element  10  are reduced, and the operation performance of the inductor element  10  is enhanced. 
     More specifically, the plurality of linear conductors  16  that are arranged at an interval of the distance D 1  in the X-axis direction and that extend in a slanting direction with respect to the Y-axis are disposed on the upper surfaces of the nonmagnetic sheets SH 1   a  and SH 1   b . Also, the plurality of linear conductors  18   a  or  18   b  that are arranged at an interval of the distance D 1  in the X-axis direction and that extend in the Y-axis direction are disposed on the upper surfaces of the magnetic sheet SH 3  and the nonmagnetic sheet SH 4 . 
     Here, the nonmagnetic sheets SH 1   a  and SH 1   b  and the magnetic sheet SH 3  and the nonmagnetic sheet SH 4  are stacked such that sheets of the same type are stacked one on top of another and that the linear conductors  16  and  18   a  (or  18   b ) are alternately arranged along the upper surfaces when viewed from the Z-axis direction. The difference between the distance in the X-axis direction from one end to the other end of each linear conductor  16  and the distance in the X-axis direction from one end to the other end of each linear conductor  18   a  (or  18   b ) corresponds to the distance D 1 . Further, the via-hole conductors  24   a  that extend from one ends of the linear conductors  16  in the Z-axis direction and the via-hole conductors  24   b  that extend from the other ends of the linear conductors  16  in the Z-axis direction are disposed in the multilayer body  12 . 
     With a plurality of sheets having a common conductor pattern being stacked one on top of another, the plurality of protrusions CN 1  that are arranged at an interval of the distance D 1  in the X-axis direction and that extend in the Y-axis direction are formed on the upper surface of the inductor element  10 . Accordingly, the heat dissipation performance is enhanced. Further, with the via-hole conductors  24   a  and  24   b  that respectively extend from one ends and the other ends of the linear conductors  16  in the Z-axis direction being disposed, a coil conductor is formed, and two linear conductors  16  or two linear conductors  18   a  and  18   b  that exist at the same position viewed from the Z-axis direction are connected in parallel to each other. Accordingly, DC resistance components of the inductor element  10  are reduced, and the operation performance of the element can be enhanced. 
     In this embodiment, the nonmagnetic sheets SH 1   a  and SH 1   b  that have a common conductor pattern are stacked one on top of another, and also the magnetic sheet SH 3  and the nonmagnetic sheet SH 4  that have another common conductor pattern are stacked one on top of another. However, the heat dissipation performance is enhanced if at least one of the nonmagnetic sheets SH 1   a  and SH 4  exists. Thus, one of the nonmagnetic sheets SH 1   a  and SH 4  may be used, and the other may be omitted. 
     In this embodiment, the linear conductors  16  extend in a slanting direction with respect to the Y-axis, whereas the linear conductors  18   a  and  18   b  extend in the Y-axis direction. However, the linear conductors  18   a  and  18   b  may extend in a slanting direction as long as the difference between the distance in the X-axis direction from one end to the other end of each linear conductor  16  and the distance in the X-axis direction from one end to the other end of each linear conductor  18   a  (or  18   b ) is adjusted to D 1 . 
     Further, in this embodiment, the via-hole conductor  24   a  that exists on the most positive side in the X-axis direction is connected to the conductor terminal  14   a  via the plate-like conductors  20   a  and the via-hole conductor  22   a , and the via-hole conductor  24   b  that exists on the most negative side in the X-axis direction is connected to the conductor terminal  14   b  via the plate-like conductors  20   b  and the via-hole conductor  22   b  (see  FIG. 1 ,  FIG. 2A , and  FIG. 3 ). However, in a case where side-surface conductors of the inductor element  10  are mounted as terminal electrodes on a printed wiring board, the plate-like conductors  20   a  and  20   b , the via-hole conductors  22   a  and  22   b , and the conductor terminals  14   a  and  14   b  are not necessary. 
     The present invention has been described and illustrated in detail. It is obvious that the description and illustration have been given merely as illustration and an example, and should not be interpreted as limitation. The spirit and scope of the present invention are limited only by the description of the attached claims. 
       10  inductor element 
     SH 0 , SH 1   a , SH 1   b , SH 4 , SH 5  nonmagnetic sheet 
     SH 2 , SH 3  magnetic sheet 
       16 ,  18   a ,  18   b  linear conductor 
       22   a ,  22   b ,  24   a ,  24   b  via-hole conductor