Patent Publication Number: US-11024455-B2

Title: Coil component

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims the benefit of priority from Japanese Patent Application Serial Nos. 2016-254735 (filed on Dec. 28, 2016) and 2016-108346 (filed on May 31, 2016), the contents of which are hereby incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a coil component including an insulator and a coil portion provided inside the insulator. 
     BACKGROUND 
     Many electronic apparatuses include coil components. Especially for mobile devices, coil components may have a chip form and may be surface-mounted on a circuit substrate included in the mobile devices. As an example of the prior art, Japanese Patent Application Publication No. 2006-324489 discloses a chip coil including a helical conductor that is embedded in a hardened insulating resin and at least whose one end is coupled to an external electrode. The helical direction of the conductor is arranged in parallel with the surface of a substrate on which the coil is mounted. Similarly, Japanese Patent Application Publication No. 2006-032430 discloses a laminated coil component having a coiled conductor formed such that its axial core direction is oriented in parallel with the surface of a substrate. 
     As another example, Japanese Patent Application Publication No. 2014-232815 disclosed a coil component including a resin insulator, a coil-shaped inner conductor provided inside the insulator, and an external electrode electrically coupled to the internal conductor. The insulator is made in a cuboid shape with the length L, the width W, and the height H, where L&gt;W≥H. The external electrode includes a conductor provided at each end of a plane perpendicular to the height H direction of the insulator as viewed in the length L direction. The internal conductor has a coil axis that is parallel with the width W direction of the insulator. 
     SUMMARY 
     As electronic devices are downsized and become thinner, electronic components mounted on such electronic substrates are also required to have a smaller size and thickness. However, such downsizing causes a significant degradation in characteristics of such electronic components. Thus, there is a demand for a compact coil component satisfying required characteristics. 
     In view of the above, one object of the disclosure is to provide a compact coil component with superior characteristics. 
     An electronic component according one embodiment of the disclosure may include an insulator and a coil portion. The insulator may be formed of a non-magnetic material. The insulator may have a width direction in a first axial direction, a length direction in a second axial direction, and a height direction in a third axial direction. The coil portion may include a circumference section. The circumference section may be wound around the first axial direction. The coil portion may be arranged inside the insulator. The first ratio of a height to a length of the insulator may be 1.5 times or less of a second ratio of a height between first inner peripheral portions of the circumference section along the third axial direction with respect to a length between second inner peripheral portions of the circumference section along the second axial direction. 
     The second ratio may be 0.6 to 1.0. 
     The third ratio of a first area partitioned by the first and second inner peripheral portions of the circumferential section with respect to a second area of the insulator portion as viewed from the first axis direction is typically 0.22 to 0.45. 
     The insulator is formed of typically a ceramic material or resin material 
     The third ratio of a first area partitioned by the first and second inner peripheral portions of the circumferential section with respect to a second area of the insulator portion as viewed from the first axis direction may be 0.22 to 0.45. 
     The insulator may be formed of a ceramic material or resin material 
     The insulator may formed into a cuboid shape; In this case, the coil component may further comprise a plurality of external electrodes electrically connected to the coil portion. Each of the plurality of external electrodes may be provided only on one surface of the insulator. 
     The coil portion and each of the plurality of external electrodes may be electrically connected through a connecting via conductive member, the connecting via conductive member is being connected to one end of the coil portion. 
     The cross section of the connecting via conductive member orthogonal to the third axial direction may be larger than a cross section of said one end of the coil portion orthogonal to the third axial direction. 
     The plurality of external electrodes may include an inner surface facing said one particular surface of the insulator and a plurality of projections. The projections may be formed on the inner surface and penetrate said one particular surface. 
     According to one aspect of the present disclosure, a downsized coil component with superior characteristics can be obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view of an electronic component according to an embodiment of the disclosure. 
         FIG. 2  is a schematic side view of the electronic component. 
         FIG. 3  is a schematic top view of the electronic component. 
         FIG. 4  is a schematic perspective side view of the upside-down electronic component. 
         FIGS. 5A to 5F  illustrate schematic top views of electrode layers included in the electronic component. 
         FIGS. 6A to 6E  are schematic sectional views of an element unit area to illustrate a basic manufacturing flow of the electronic component. 
         FIGS. 7A to 7D  are schematic sectional views of an element unit area to illustrate a basic manufacturing flow of the electronic component. 
         FIGS. 8A to 8D  are schematic sectional views of an element unit area to illustrate a basic manufacturing flow of the electronic component. 
         FIGS. 9A to 9C  schematically show high frequency characteristics of a coil component. 
         FIG. 10  illustrates a schematic side view of the electronic component with sizes of various elements of the electronic component. 
         FIG. 11  illustrates a schematic top view of the electronic component with sizes of various elements of the electronic component. 
         FIG. 12A  is a schematic perspective view of an electronic component according to the first arrangement of another embodiment of the disclosure. 
         FIG. 12B  is an external perspective view of the electronic component of  FIG. 12A . 
         FIG. 13A  is a schematic perspective side view of the electronic component of  FIG. 12A . 
         FIG. 13B  is a schematic external side view of the electronic component of  FIG. 12B . 
         FIG. 14  is a schematic perspective top view of the electronic component of  FIG. 12A . 
         FIG. 15  is a schematic perspective side view of the upside-down electronic component of  FIG. 12A . 
         FIGS. 16A to 16F  illustrate schematic top views of electrode layers included in the electronic component. 
         FIG. 17  is a schematic perspective view of an electronic component according to the second arrangement of another embodiment of the disclosure. 
         FIG. 18  is a schematic perspective side view of the electronic component of  FIG. 17 . 
         FIG. 19  is a schematic perspective top view of the electronic component of  FIG. 17 . 
         FIG. 20  is a schematic perspective view of an electronic component according to the third arrangement of another embodiment of the disclosure. 
         FIG. 21  is a schematic perspective side view of the electronic component of  FIG. 20 . 
         FIG. 22  is a schematic perspective top view of the electronic component of  FIG. 20 . 
         FIG. 23A  is a schematic perspective view of an electronic component according to an embodiment of the disclosure. 
         FIG. 23B  is a schematic perspective view of an exemplary variation of the electronic component  100 . 
         FIG. 23C  is a schematic perspective view of another exemplary variation of the electronic component  100 . 
         FIGS. 24A-24C  each illustrate an electronic component corresponding to the electronic component  1100  according to the second embodiment. 
         FIG. 25  shows the inductance (L value) properties of each of the electronic components illustrated in  FIGS. 23A-23C  and  FIGS. 24A-24C . 
         FIG. 26  shows the Q value properties of each of the electronic components illustrated in  FIGS. 23A-23C  and  FIGS. 24A-24C . 
         FIGS. 27A-27D  are presented to compare the regions available for the internal conductors depending on the configurations of electronic components according to various embodiments of the present invention. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Embodiments of the disclosure will be described hereinafter with reference to the drawings. 
     First Embodiment—Basic Structure 
       FIG. 1  is a schematic perspective view of an electronic component according to an embodiment of the disclosure,  FIG. 2  is a schematic side view of the electronic component, and  FIG. 3  is a schematic top view of the electronic component. In these drawings, the X-axis, Y-axis and Z-axis indicate three axial directions that are perpendicular to each other. 
     An electronic component  100  according to the embodiment may be configured as a coil component that is surface-mounted on a substrate. The electronic component  100  may include an insulator  10 , an internal conductor  20 , and an external electrode  30 . 
     The insulator  10  may include a top surface  101 , a bottom surface  102 , a first end surface  103 , a second end surface  104 , a first side surface  105 , and a second side surface  106 . The insulator  10  is made in a cuboid shape that has the width in the X-axial direction, the length in the Y-axial direction and the height in the Z-axial direction. The insulator  10  may have a width of 0.05 to 0.2 mm, a length of 0.1 to 0.4 mm, and a height of 0.05 to 0.4 mm. In this embodiment, the width of the insulator  10  may be about 0.2 mm, the length may be about 0.35 mm, and the height may be about 0.2 mm. 
     The insulator  10  may include a body  11  and an upper portion  12 . The body  11  may include the internal conductor  20  thereinside and form a main part of the insulator  10 . The upper portion  12  provides the top surface  101  of the insulator  10 . The upper portion  12  may be formed as, for example, a printed layer on which a model number of the electronic component  100  is printed. 
     The body  11  and the upper portion  12  may be formed of an insulating material. The insulating material mainly contains resin. The insulating material for the body  11  may be a resin that is cured by heat, light, a chemical reaction or the like. Such resins may include, for example, polyimide, epoxy resin, liquid crystal polymer, and the like. The upper portion  12  may be formed of the above-mentioned material, or a resin film or the like. Alternatively, the insulator  10  may be formed of ceramic materials such as glass. 
     The insulator  10  may be formed of a composite material that includes a filler in a resin. As such a filler, ceramic particles such as silica, alumina, zirconia or the like may be typically used. The configuration of the ceramic particles may be, but not limited to, spherical. Alternatively it may be an acicular shape, a scale-like shape or the like. 
     The internal conductor  20  may be provided inside the insulator  10 . The internal conductor  20  may include a plurality of pillared conductive members  21  and a plurality of connecting conductive members  22 . The plurality of pillared conductive members  21  and the plurality of connecting conductive members  22  together form a coil portion  20 L. 
     The plurality of pillared conductive members  21  may be each formed in a substantially columnar shape with a central axis arranged in parallel with the Z-axial direction. The plurality of pillared conductive members  21  may include two groups of the conductors that are arranged so as to face to each other in the substantially Y-axial direction. One of the two conductor groups is first pillared conductive members  211 . The first pillared conductive members  211  are arranged in the X-axial direction at a predetermined interval The other of the two conductor groups is second pillared conductive members  212 . The second pillared conductive members  212  are also arranged in the X-axial direction at a predetermined interval. 
     The substantially columnar shape herein may include any columnar shape of which cross section perpendicular to the axis (in the direction perpendicular to the central axis) is a circle, an ellipse, or an oval. For example, the substantially columnar shape may mean any prism whose cross section is an ellipse or an oval in which the ratio of the major axis to the minor axis is 3 or smaller. 
     The first pillared conductive members  211  and the second pillared conductive members  212  may be configured to have the same radius and the same height respectively. The illustrated example includes five of the first pillared conductive members  211  and five of the second pillared conductive members  212 . As will be further described later, the first and second pillared conductive members  211 ,  212  may be formed by stacking two or more via conductive members in the Z-axial direction. 
     Note that the reason why the pillared members have the substantially same radius is to prevent increase of resistance and this may be realized by reducing variation in the dimension of the pillared members as viewed in the same direction to 10% or smaller. Moreover the reason why the pillared members have the substantially same height is to secure stacking accuracy of the layers and this may be realized by reducing a difference in the height of the pillared members to, for example, 1 μm or smaller. 
     The plurality of connecting conductive members  22  may include two groups of conductors that are formed in parallel with the XY plane and arranged so as to face to each other in the Z-axial direction. One of the two conductor group is first connecting conductive members  221  that extend along the Y-axial direction and are arranged in the X-axial direction at a predetermined interval so as to connect between the first pillared conductive members  211  and the second pillared conductive members  212  respectively. The other of the two conductor group is second connecting conductive members  222  that extend at a predetermined angle with the Y-axial direction and are arranged in the X-axial direction at a predetermined interval so as to connect between the first pillared conductive members  211  and the second pillared conductive members  212  respectively. The illustrated example includes five of the first connecting conductive members  221  and five of the second connecting conductive members  222 . 
     Referring aging to  FIG. 1 , the first connecting conductive members  221  are each connected with upper ends of a predetermined pair of the pillared conductive members  211 ,  212 , and the second connecting conductive members  222  are each connected with lower ends of a predetermined pair of the pillared conductive members  211 ,  212 . More specifically, the first and second pillared conductive members  211 ,  212  and the first and second connecting conductive members  221 ,  222  may be each connected to each other so as to form circumference sections Cn (C 1 -C 5 ) of the coil portion  20 L and such that the circumference sections Cn form a rectangular helix in the X-axial direction. In this manner, provided is the coil portion  20 L that has the central axis (a coil axis) in the X-axial direction and has an rectangular opening. 
     In this embodiment, the circumference sections Cn include five circumference sections C 1 -C 5 . The opening of each of the circumference sections C 1 -C 5  may have a substantially same shape. 
     The internal conductor  20  may further include an extended portion  23 , a comb-tooth block portion  24  and the coil portion  20 L may be connected to the external electrode  30  ( 31 ,  32 ). 
     The extended portion  23  may include a first extended portion  231  and a second extended portion  232 . The first extended portion  231  may be coupled to a lower end of the first pillared conductive member  211  that forms one end of the coil portion  20 L, and the second extended portion  232  may be coupled to a lower end of the second pillared conductive member  212  that forms the other end of the coil portion  20 L. The first and second extended portions  231 ,  232  may be provided in the XY plane in which the second connecting conductive members  222  are provided and may be arranged in parallel with the Y-axial direction. 
     The comb-tooth block portion  24  may include a first comb-tooth block  241  and a second comb-tooth block  242 . The first comb-tooth block  241  and the second comb-tooth block  242  are disposed so as to face to each other in the Y-axial direction. The first and second comb-tooth blocks  241 ,  242  may each be arranged such that their comb tooth ends face upward in  FIG. 1 . A part of the first and second comb-tooth blocks  241 ,  242  may be exposed on the end surfaces  103 ,  104  and the bottom surface  102  of the insulator  10 . The first and second extended portions  231 ,  232  may be coupled to a space between predetermined two adjacent comb teeth of the first and second comb-tooth block portions  241 ,  242  respectively (see  FIG. 3 ). At the bottom of the first and second comb-tooth block portions  241 ,  242 , conductive layers  301 ,  302  that are underlayers of the external electrode  30  may be provided respectively (see  FIG. 2 ). 
     The external electrode  30  may form an external terminal for surface mounting. The external electrode  30  may include first and second external electrodes  31 ,  32  that face to each other in the Y-axial direction. The first and second external electrodes  31 ,  32  may be formed in designated regions on the outer surface of the insulator  10 . 
     More specifically, the first and second external electrodes  31 ,  32  may each include a first portion  30  A that covers each end of the bottom surface of the insulator  10  in the Y-axial direction, and a second portion  30 B that covers the end surfaces  103 ,  104  of the insulator  10  over a predetermined height of the end surfaces  103 ,  104  as illustrated in  FIG. 2 . The first portions  30  A may be electrically connected to the bottoms of the first and second comb-tooth block portions  241 ,  242  through the conductive layers  301 ,  302  respectively. The second portion  30 B may be formed on the end surfaces  103 ,  104  of the insulator  10  so as to cover the comb teeth portions of the first and second comb-tooth block portions  241 ,  242 . 
     The pillared conductive members  21 , the connecting conductive members  22 , the extended portion  23 , the comb-tooth block portion  24 , and the conductive layers  301 ,  302  may be formed of a metal such as Cu (copper), Al (aluminum), Ni (nickel) or the like. In this embodiment, these may be formed of copper or a copper alloy plated layer. The first and second external electrodes  31 ,  32  may be formed by, for example, Ni/Sn plating. 
       FIG. 4  is a schematic side view of the upside-down electronic component  100 . As shown in  FIG. 4 , the electronic component  100  may include a film layer L 1  and electrode layers L 2 -L 6 . In the embodiment, the film layer L 1  and the electrode layers L 2 -L 6  may be stacked sequentially in the Z-axial direction from the top surface  101  to the bottom surface  102 . The number of the layers may not be particularly limited and may be six in this example. 
     The film layer L 1  and the electrode layers L 2 -L 6  may include corresponding insulator  10  and internal conductor  20 .  FIGS. 5A-5F  are schematic top views of the film layer L 1  and the electrode layers L 2 -L 6  of  FIG. 4 . 
     The film layer L 1  may be formed of the upper portion  12  that serves as the top surface  101  of the insulator  10  ( FIG. 5A ). The electrode layer L 2  may include an insulating layer  110  ( 112 ) and the first pillared conductive members  211  ( FIG. 5B ). The insulating layer  110  ( 112 ) forms a part of the insulator  10  (the body  11 ). The electrode layer L 3  may include the insulating layer  110  ( 113 ), and via conductive members V 1  that form a part of the pillared conductive members  211 ,  212  ( FIG. 5C ). The electrode layer L 4  may include the insulating layer  110  ( 114 ), the via conductive members V 1 , and via conductive members V 2  that form a part of the comb-tooth block portions  241 ,  242  ( FIG. 5D ). The electrode layer L 5  may include the insulating layer  110  ( 115 ), the via conductive members V 1 , V 2 , the extended portions  231 ,  232 , and the second connecting conductive members  222  ( FIG. 5E ). The electrode layer L 6  may include the insulating layer  110  ( 116 ) and the via conductive members V 2  (FIG.  5 F). 
     The electrode layers L 2 -L 6  may be stacked in the height direction with bonding surfaces S 1 -S 4  (see  FIG. 4 ) interposed therebetween. Accordingly, the insulating layers  110  and the via conductive members V 1 , V 2  have boundaries in the height direction. The electronic component  100  may be manufactured by a build-up method in which the electrode layers L 2 -L 6  are sequentially fabricated and layered in the stated order from the electrode layer L 2 . 
     Basic Manufacturing Process 
     A basic manufacturing process of the electronic component  100  will be now described. A plurality of the electronic components  100  may be simultaneously fabricated on a wafer and may be then diced into pieces (chips). 
       FIGS. 6 to 8  are schematic sectional views of an element unit area to illustrate a part of the manufacturing process of the electronic component  100 . More specifically, in the manufacturing process, a resin film  12 A (the film layer L 1 ) is adhered to a base plate S to form the upper portion  12  and the electrode layers L 2  to L 6  are sequentially formed thereon. As the base plate S, a silicon, glass or sapphire substrate may be used. Typically a conductive pattern that forms the internal conductor  20  may be formed by electroplating, subsequently the formed conductive pattern may be covered by an insulating resin material to form the insulating layer  110 . These steps may be repeated. 
       FIGS. 6A to 6E  and  FIGS. 7A to 7D  illustrate a manufacturing process of the electrode layer L 3 . 
     In this process, a seed layer (a feed layer) SL 1  for electroplating may be formed on the surface of the electrode layer L 2  by, for example, sputtering ( FIG. 6A ). The seed layer SL 1  may be formed of any conductive material, for example, Ti (titanium) or Cr (chromium). The electrode layer L 2  may include the insulating layer  112  and the connecting conductive members  221 . The connecting conductive members  221  may be provided under the insulating layer  112  so as to contact the resin film  12 A. 
     Subsequently a resist film R 1  may be formed on the seed layer SL 1  ( FIG. 6B ). The resist film R 1  may be exposed and developed to form a resist pattern having a plurality of openings P 1  that correspond to the via conductive members V 13  which form a part of the pillared conductive members  21  ( 211 ,  212 ) through the seed layer SL 1  ( FIG. 6C ). Subsequently a descum process may be performed to remove resist residue in the opening P 1  ( FIG. 6D ). 
     The base plate S may be then immersed in a Cu plating bath and an voltage may be applied to the seed layer SL 1  to form the plurality of via conductive members V 13  made of a Cu plating layer within the openings P 1  ( FIG. 6E ). After the resist film R 1  and the seed layer SL 1  may be removed ( FIG. 7A ), the insulating layer  113  that covers the via conductive members V 13  may be formed ( FIG. 7B ). The insulating layer  113  may be formed by printing or applying a resin material or applying a resin film on the electrode layer L 2  and then hardening the resin. After the resin is hardened, the surface of the insulating layer  113  may be polished so as to expose tips of the via conductive members V 13  by using a polishing apparatus such as a chemical mechanical polish machine (CMP machine), a grinder or the like ( FIG. 7C ).  FIG. 7C  illustrates an example of the polishing process (CMP) of the insulating layer  113  with a revolving polishing pad P. Here, the base plate S may be placed upside down on a polishing head H that is capable of spinning. As described above, the electrode layer L 3  may be formed on the electrode layer L 2  ( FIG. 7D ). 
     A fabrication method of the insulating layer  112  has not been described above, but it may be typically formed in the same manner as the insulating layer  113 , more specifically, a resin material may be printed or applied or a resin film may be applied and then cured. The cured resin may be then polished by chemical mechanical polishing (CMP), a grinder or the like. 
     In the same manner as described above, the electrode layer L 4  may be formed on the electrode layer L 3 . 
     A plurality of via conductive members (second via conductive members) that are coupled to the via conductive members V 13  (first via conductive members) may be formed on the insulating layer  113  (a second insulating layer) of the electrode layer L 3 . More specifically, a seed layer that covers the surface of the first via conductive members may be formed on the surface of the second insulating layer. A resist pattern that has openings at the position corresponding to the surface of the first via conductive members may be then formed and the second via conductive members may be formed by electroplating using the resist pattern as a mask. A third insulating layer that covers the second via conductive members may be subsequently formed on the second insulating layer. The surface of the third insulating layer may be then polished to expose tips of the second via conductive members. 
     In the above-described fabrication process of the second via conductive members, the via conductive members V 2  that form a part of the comb-tooth block portion  24  ( 241 ,  242 ) may be formed at the same time (see  FIG. 4  and  FIG. 5D ). In this case, the resist pattern has openings that correspond to the region where the via conductive members V 2  are formed in addition to the openings that correspond to the region where the second via conductive members are formed. 
       FIGS. 8A to 8D  illustrate a part of the manufacturing process of the electrode layer L 5 . 
     A seed layer SL 3  for electroplating may be firstly formed on the electrode layer L 4 , and then a resist pattern (a resist film R 3 ) that has openings P 2 , P 3  may be sequentially formed on the seed layer SL 3  ( FIG. 8A ). Subsequently a descum process may be performed to remove resist residue in the openings P 2 , P 3  ( FIG. 8B ). 
     The electrode layer L 4  may include the insulating layer  114  and via conductive members V 14 , V 24 . The via conductive members V 14  may correspond to the via members (V 1 ) that form a part of the pillared conductive members  21  ( 211 ,  212 ), and the via conductive members V 24  may correspond to the via members (V 2 ) that correspond to a part of the comb-tooth block portion  24  ( 241 ,  242 ) (see  FIGS. 5C and 5D ). The opening P 2  may face the via conductive member V 14  in the electrode layer L 4  with the seed layer SL 3  interposed therebetween, and opening P 3  may face the via conductive member V 24  in the electrode layer L 4  with the seed layer SL 3  interposed therebetween. The openings P 2  may be each formed in the shape that conforms with the corresponding connecting conductive member  222 . 
     The base plate S may be then immersed in a Cu plating bath and an voltage may be applied to the seed layer SL 3  to form via conductive members V 25  and the connecting conductive members  222  made of a Cu plating layer within the openings P 2 , P 3  ( FIG. 8C ). The via conductive members V 25  may correspond to the via members (V 2 ) that form a part of the comb-tooth block portion  24  ( 241 ,  242 ). 
     After the resist film R 3  and the seed layer SL 3  are removed, the insulating layer  115  that covers the via conductive members V 25  and the connecting conductive members  222  may be formed ( FIG. 8D ). Although it is not illustrated in the drawings, the surface of the insulating layer  115  may be polished to expose tips of the via conductive members V 25 , the seed layer and the resist pattern may be subsequently formed, and the electroplating process may be then performed. By repeating the above-described processes, the electrode layer L 5  illustrated in  FIG. 4  and  FIG. 5E  is fabricated. 
     After the conductive layers  301 ,  302  are formed on the comb-tooth block portion  24  ( 241 ,  242 ) exposed on the surface (the bottom surface  102 ) of the insulating layer  115 , the first and second external electrodes  31 ,  32  may be formed. 
     Structure In The Embodiment 
     As electronic devices are downsized in recent years, it tends to be difficult to secure coil characteristics. Characteristics of a coil component depend largely on the size, shape and the like of the coil portion included in a coil component, and a larger opening size typically leads to higher inductance characteristics. However, the downsizing of a coil component constrains the size of the insulator and the constrained insulator size results in deteriorated inductance characteristics. Therefore, this embodiment provides a compact coil component with superior characteristics by optimizing the dimensional ratio of the opening of the coil portion. 
       FIG. 9A - FIG. 9C  are schematic views of a coil component for explaining high frequency characteristics of the coil component. The coil component  200  shown in  FIG. 9A  includes insulator  210  and coil portion  220 C arranged in the insulator  210 . The insulator may have a cuboid shape. For ease of understanding, the circumference section Cn is represented by the hatched ring having a simple rectangular shape (FIG.  10  uses a similar hatched ring to represent circumference section Cn). The reference number  230  denotes external electrode. 
     In a typical downsizing process, the insulator  210  is made low-profile by bringing into closer relationship the upper side (hereinafter, referred to as the “Side A”) and the lower side (hereinafter, referred to as the “Side B”) of the circumference section Cn. The Side A and the Side B with a closer distance therebetween increases mutual interference between the magnetic flux (magnetic field) generated by the Side A and the magnetic flux generated by the Side B. For example, as shown in  FIG. 9B , when the magnetic flux φA is generated by electric current IA flowing through the Side A and the magnetic flux φB is generated by electric current IB flowing through the Side B, the direction of the magnetic flux φA is opposite to that of the magnetic flux φB. Accordingly, the closer the Side A and the Side B are to each other, the greater the mutual interference (cancellation) between the magnetic flux φA and the magnetic flux φB becomes. As a result, the superposed magnetic flux φT in the opening of the circumference section Cn becomes small, causing failure to generate an inductance as designed 
     In this embodiment, by increasing the distance between the Side A and Side B, as shown in  FIG. 9C , the mutual interference between the magnetic flux φA and the magnetic flux φB may be suppressed, the superposed magnetic flux φT for the circumference section Cn is increased, and thereby a higher inductance may be achieved. Such a higher inductance makes it possible to shorten the line length and as a result to decrease the resistance thereof, thereby attaining a higher Q value. 
     A required distance between the Side A and Side B of the circumference section Cn may be secured by increasing the hight of the insulator  210 . In so doing, it is not necessary to increase the mounting area of the coil component. Accordingly, it is possible to provide a compact coil component with superior characteristics. 
     The coil component  200  manufactured by use of a typical downsizing method has a small dimensional ratio (Hd/ld) of the inner circumferential surface corresponding to the opening (core) of the circumferential section due to the dimensional constraints in the external dimension of the chip component (See,  FIG. 9 ). On the other hand, in this embodiment, the external dimension of the chip component has been redesigned so as to heighten the dimensional ratio (Hd/ld) without changing the volume of the insulator  10 . Thus, a higher inductance may be efficiently achieved, and thereby obtaining a coil component with a high Q value. 
     More particularly, the coil component  100  in accordance with this embodiment, as shown in  FIG. 10 , may be configured such that the ratio (Ha/La) of the height (Ha) of the insulator part  10  to the length (La) of the insulator part  10  is 1.5 times or less of the ratio (Hd/ld) of the height (hd) between the inner peripheral portions of the circumference section Cn along the Z-axial direction with respect to the length (ld) between the inner peripheral portions of the circumference section Cn along the Y-axial direction. Thus, the Q value of the coil component  100  may be efficiently enhanced. 
     Here, “the length (ld) between the inner peripheral portions of the circumference section Cn along the Y-axial direction” refers to the distance along the Y-axial direction between the opposed surfaces of the first and second pillared conductive members  211 ,  212  projected to the YZ plane. Also, “the height (hd) between the inner peripheral portions of the circumference section Cn along the Z-axial direction” means the distance along the Z-axial direction between the opposed surfaces of the first and second connecting conductive members  221 ,  222  projected to the YZ plane. In measuring the length (ld) between the inner peripheral portions of the circumference section Cn, the coil component  100  is processed by cross section grinding or milling to a plane extending the center of the insulator in the Z-axial direction (the height direction). The length (ld) between the inner peripheral portions of the circumference section Cn may be obtained by measuring the distance between the first and second pillared conductive members  211 ,  212  by a scanning electron microscope (SEM) at a magnification of about 200×. In measuring the height (hd) between the inner peripheral portions of the circumference section Cn, the coil component  100  is processed by cross section grinding or milling to a plane extending the center of the insulator in the X-axial direction (the width direction). The height (hd) between the inner peripheral portions of the circumference section Cn may be obtained by measuring the distance between the first and second connecting conductive members  221 ,  222  by use of SEM. The above observation sample may be used when measuring the dimensions of other sections. 
     In this embodiment, the opening dimensional ratio (Hd/ld) of the circumference section Cn maybe, for example, 0.6 to 1.2. It should be noted that the opening dimensional ratio (Hd/ld) is not limited to the above range. Thus, it is possible to stably secure a high inductance value and Q value. 
     The ratio (Sd/Sa) of the area (Sd) partitioned by the inner circumferential portion of the circumferential section Cn with respect to the area (Sa) of the insulator portion  12  as viewed from the coil axial direction (X-axial direction) may be, for example, 0.22 to 0.45 (22% to 45%). It should be noted that the ratio (Sd/Sa) is not limited to the above range. Thus, the inductance value of the coil component  100  may be efficiently enhanced. 
     Furthermore, according to the embodiment, the first and second comb-tooth blocks  241 ,  242  may compensate for lack of stiffness of the insulator  10  due to its increased height as each of the first and second comb-tooth blocks  241 ,  242  is arranged such that their comb tooth ends face upward in  FIG. 1 . Thus, the reliability of the coil component  100  may be enhanced. 
     EXPERIMENT EXAMPLE 
     With reference to  FIGS. 10 and 11 , experiments performed by the inventors will be described. The opening of the circumference section Cn may be referred to as a core portion. 
     Test Example 1 
     A sample of coil component was produced to include an insulator formed of glass and a coil portion. Their dimensions were as follows: 
     Insulator: a length (La) 370 μm; a width (Wa) 200 μm; and a height (Ha) 215 μm
     Coil portion: a conductor dimension in the Y-axial direction (lc) 35 μm; a conductor dimension in the X-axial direction (wc) 10 μm; a conductor dimension in the Z-axial direction (hc) 35 μm; intervals between the adjacent portions of the circumference section in the X-axial direction (inter-conductor distance g) 20 μm; a core portion dimension in the Y-axial direction (ld) 200 μm; a core portion dimension in the circumference section Cn in the X-axial direction (wd) 130 μm; a core portion dimension in the Z-axial direction (hd) 85 μm   Side margin: a Y-axis margin (lb) 50 μm; an X-axis margin (wb) 30 μm; a Z-axis margin (hb) 30 μm.   

     An RF impedance analyzer (E4991A from Agilent Technologies) was used to measure the inductance value (L value) and the Q value of the produced sample at 500 MHz and at 1.8 GHz, respectively. The measured L value was 2.6 nH and the measured Q value was 27. 
     Test Example 2 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 350 μm, 200 μm, and 230 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 180 μm, 130 μm, and 100 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.7 nH and the measured Q value was 28. 
     Test Example 3 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 320 μm, 200 μm, and 250 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 150 μm, 130 μm, and 120 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.8 nH and the measured Q value was 29. 
     Test Example 4 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 305 μm, 200 μm, and 265 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 135 μm, 130 μm, and 135 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.9 nH and the measured Q value was 30. 
     Test Example 5 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 275 μm, 200 μm, and 290 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 105 μm, 130 μm, and 160 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.6 nH and the measured Q value was 29. 
     Test Example 6 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 265 μm, 200 μm, and 300 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 95 μm, 130 μm, and 170 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.3 nH and the measured Q value was 28. 
     Test Example 7 
     A sample of coil component having an insulator formed of resin and a coil portion was produced. Their dimensions were as follows: 
     Insulator: a length (La) 410 μm; a width (Wa) 200 μm; a height (Ha) 195 μm
     Coil portion: a conductor dimension in the Y-axial direction (lc) 35 μm; a conductor dimension in the X-axial direction (wc) 24 μm; a conductor dimension in the Z-axial direction (hc) 35 μm; an inter-conductor distance g 10 μm; a core portion dimension in the Y-axial direction (ld) 250 μm; a core portion dimension in the X-axial direction (wd) 160 μm; a core portion dimension in the Z-axial direction (hd) 85 μm   Side margin: a Y-axis margin (lb) 45 μm; an X-axis margin (wb) 20 μm; a Z-axis margin (hb) 20 μm.   

     The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.0 nH and the measured Q value was 31. 
     Test Example 8 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 380 μm, 200 μm, and 210 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 220 μm, 160 μm, and 100 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.2 nH and the measured Q value was 32. 
     Test Example 9 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 350 μm, 200 μm, and 230 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 190 μm, 160 μm, and 120 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.3 nH and the measured Q value was 33. 
     Test Example 10 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 320 μm, 200 μm, and 250 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 160 μm, 160 μm, and 140 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.4 nH and the measured Q value was 34. 
     Test Example 11 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 310 μm, 200 μm, and 260 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 150 μm, 160 μm, and 150 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.5 nH and the measured Q value was 34. 
     Test Example 12 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 275 μm, 200 μm, and 290 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 115 μm, 160 μm, and 180 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.3 nH and the measured Q value was 32. 
     Test Example 13 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 255 μm, 200 μm, and 315 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 95 μm, 160 μm, and 205 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.1 nH and the measured Q value was 31. 
     Test Example 14 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 310 μm, 200 μm, and 260 μm, respectively; the conductor dimension in the Y-axial direction (lc), that in the X-axial direction (wc), and that in the Z-axial direction (hc) were 30 μm, 24 μm, and 30 μm, respectively; and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 160 μm, 160 μm, and 160 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.6 nH and the measured Q value was 36. 
     Test Example 15 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 310 μm, 200 μm, and 260 μm, respectively; the conductor dimension in the Y-axial direction (lc), that in the X-axial direction (wc), and that in the Z-axial direction (hc) were 25 μm, 24 μm, and 25 μm, respectively; and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 170 μm, 160 μm, and 170 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 3.8 nH and the measured Q value was 37. 
     Test Example 16 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 310 μm, 200 μm, and 260 μm, respectively; the conductor dimension in the Y-axial direction (lc), that in the X-axial direction (wc), and that in the Z-axial direction (hc) were 20 μm, 24 μm, and 20 μm, respectively; and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 180 μm, 160 μm, and 180 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 4.2 nH and the measured Q value was 37. 
     Test Example 17 
     Another sample was produced under the same conditions as in Test Example 7 except that the length (La), width (Wa) and height (Ha) of the insulator were 310 μm, 200 μm, and 260 μm, respectively; the conductor dimension in the Y-axial direction (lc), that in the X-axial direction (wc), and that in the Z-axial direction (hc) were 15 μm, 24 μm, and 15 μm, respectively; and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 190 μm, 160 μm, and 190 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 4.8 nH and the measured Q value was 36. 
     Comparative Example 1 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 400 μm, 200 μm, and 200 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 230 μm, 130 μm, and 70 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.2 nH and the measured Q value was 22. 
     Comparative Example 2 
     Another sample was produced under the same conditions as in Test Example 1 except that the length (La), width (Wa) and height (Ha) of the insulator were 407 μm, 200 μm, and 202 μm, respectively and the core portion dimension in the Y-axial direction (ld), that in the X-axial direction (wd), and that in the Z-axial direction (hd) were 237 μm, 130 μm, and 72 μm, respectively. The inductance (L value) and Q value of the produced sample were measured under the same conditions as in Test Example 1. The measured L value was 2.3 nH and the measured Q value was 23. 
     The conditions, dimension ratios, the areas of the insulator and the coil portion as viewed from the coil axial direction (X-axial direction), the ratio of the areas, and coil characteristics of the Test Examples 1-17 and the Comparative Example 1-2 are summarized in Tables 1-3 below. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                   
                   
                   
                 Inter- 
               
               
                   
                   
                   
                 Internal 
                 conductor 
               
               
                   
                 Insulator 
                 Side Margin 
                 Conductor 
                 Distance 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 La 
                 Wa 
                 Ha 
                 lb 
                 wb 
                 hb 
                 lc 
                 wc 
                 hc 
                 g 
               
               
                   
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
                 [μm] 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Comparative Example 1 
                 glass 
                 400 
                 200 
                 200 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Comparative Example 2 
                 glass 
                 407 
                 200 
                 202 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 1 
                 glass 
                 370 
                 200 
                 215 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 2 
                 glass 
                 350 
                 200 
                 230 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 3 
                 glass 
                 320 
                 200 
                 250 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 4 
                 glass 
                 305 
                 200 
                 265 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 5 
                 glass 
                 275 
                 200 
                 290 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 6 
                 glass 
                 265 
                 200 
                 300 
                 50 
                 30 
                 30 
                 35 
                 10 
                 35 
                 20 
               
               
                 Test Sample 7 
                 resin 
                 410 
                 200 
                 195 
                 45 
                 20 
                 20 
                 35 
                 24 
                 35 
                 10 
               
               
                 Test Sample 8 
                 resin 
                 380 
                 200 
                 210 
                 45 
                 20 
                 20 
                 35 
                 24 
                 35 
                 10 
               
               
                 Test Sample 9 
                 resin 
                 350 
                 200 
                 230 
                 45 
                 20 
                 20 
                 35 
                 24 
                 35 
                 10 
               
               
                 Test Sample 10 
                 resin 
                 320 
                 200 
                 250 
                 45 
                 20 
                 20 
                 35 
                 24 
                 35 
                 10 
               
               
                 Test Sample 11 
                 resin 
                 310 
                 200 
                 260 
                 45 
                 20 
                 20 
                 35 
                 24 
                 35 
                 10 
               
               
                 Test Sample 12 
                 resin 
                 275 
                 200 
                 290 
                 45 
                 20 
                 20 
                 36 
                 24 
                 35 
                 10 
               
               
                 Test Sample 13 
                 resin 
                 255 
                 200 
                 315 
                 45 
                 20 
                 20 
                 35 
                 24 
                 35 
                 10 
               
               
                 Test Sample 14 
                 resin 
                 310 
                 200 
                 260 
                 45 
                 20 
                 20 
                 30 
                 24 
                 30 
                 10 
               
               
                 Test Sample 15 
                 resin 
                 310 
                 200 
                 260 
                 45 
                 20 
                 20 
                 25 
                 24 
                 25 
                 10 
               
               
                 Test Sample 16 
                 resin 
                 310 
                 200 
                 260 
                 45 
                 20 
                 20 
                 20 
                 24 
                 20 
                 10 
               
               
                 Test Sample 17 
                 resin 
                 310 
                 200 
                 260 
                 45 
                 20 
                 20 
                 15 
                 24 
                 15 
                 10 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 Core Portion 
                   
               
               
                   
                 Dimension 
                 Dimensional Ratio 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 ld 
                 wd 
                 hd 
                 Ha/La 
                 hd/ld 
                   
               
               
                   
                 [μm] 
                 [μm] 
                 [μm] 
                 X 
                 Y 
                 X/Y 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Comparative Example 1 
                 230 
                 130 
                 70 
                 0.5 
                 0.3 
                 1.6 
               
               
                 Comparative Example 2 
                 237 
                 130 
                 72 
                 0.5 
                 0.3 
                 1.6 
               
               
                 Test Sample 1 
                 200 
                 130 
                 85 
                 0.6 
                 0.4 
                 1.4 
               
               
                 Test Sample 2 
                 180 
                 130 
                 100 
                 0.7 
                 0.6 
                 1.2 
               
               
                 Test Sample 3 
                 150 
                 130 
                 120 
                 0.8 
                 0.8 
                 1.0 
               
               
                 Test Sample 4 
                 135 
                 130 
                 135 
                 0.9 
                 1.0 
                 0.9 
               
               
                 Test Sample 5 
                 105 
                 130 
                 160 
                 1.1 
                 1.5 
                 0.7 
               
               
                 Test Sample 6 
                 95 
                 130 
                 170 
                 1.1 
                 1.8 
                 0.6 
               
               
                 Test Sample 7 
                 250 
                 160 
                 85 
                 0.5 
                 0.3 
                 1.4 
               
               
                 Test Sample 8 
                 220 
                 160 
                 100 
                 0.6 
                 0.5 
                 1.2 
               
               
                 Test Sample 9 
                 190 
                 160 
                 120 
                 0.7 
                 0.6 
                 1.0 
               
               
                 Test Sample 10 
                 160 
                 160 
                 140 
                 0.8 
                 0.9 
                 0.9 
               
               
                 Test Sample 11 
                 150 
                 160 
                 150 
                 0.8 
                 1.0 
                 0.8 
               
               
                 Test Sample 12 
                 115 
                 160 
                 180 
                 1.1 
                 1.6 
                 0.7 
               
               
                 Test Sample 13 
                 95 
                 160 
                 205 
                 1.2 
                 2.2 
                 0.6 
               
               
                 Test Sample 14 
                 160 
                 160 
                 160 
                 0.8 
                 1.0 
                 0.8 
               
               
                 Test Sample 15 
                 170 
                 160 
                 170 
                 0.8 
                 1.0 
                 0.8 
               
               
                 Test Sample 16 
                 180 
                 160 
                 180 
                 0.8 
                 1.0 
                 0.8 
               
               
                 Test Sample 17 
                 190 
                 160 
                 190 
                 0.8 
                 1.0 
                 0.8 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE 3 
               
             
            
               
                   
                   
               
               
                   
                 Insulator 
                 Core Portion 
                 Area 
                 Core Portion Area 
                   
               
               
                   
                 Area 
                 Area 
                 Ratio 
                 as Compared to 
                 Results 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sa 
                 Sd 
                 Sd/Sa 
                 Comparative Example 1. 
                 L Value 
                 Q Value 
               
               
                   
                 [μm2] 
                 [μm2] 
                 [%] 
                 [%] 
                 [nH] 
                 — 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Comparative Example 1 
                 80000 
                 16100 
                 20 
                   
                 2.2 
                 22 
               
               
                 Comparative Example 2 
                 82214 
                 17064 
                 21 
                 1.06 
                 2.3 
                 23 
               
               
                 Test Sample 1 
                 79550 
                 17000 
                 21 
                 1.06 
                 2.6 
                 27 
               
               
                 Test Sample 2 
                 80500 
                 18000 
                 22 
                 1.12 
                 2.7 
                 28 
               
               
                 Test Sample 3 
                 80000 
                 18000 
                 23 
                 1.12 
                 2.8 
                 29 
               
               
                 Test Sample 4 
                 80825 
                 18225 
                 23 
                 1.13 
                 2.9 
                 30 
               
               
                 Test Sample 5 
                 79750 
                 16800 
                 21 
                 1.04 
                 2.6 
                 29 
               
               
                 Test Sample 6 
                 79500 
                 16150 
                 20 
                 1.00 
                 2.3 
                 28 
               
               
                 Test Sample 7 
                 79950 
                 21250 
                 27 
                 1.32 
                 3.0 
                 31 
               
               
                 Test Sample 8 
                 79800 
                 22000 
                 28 
                 1.37 
                 3.2 
                 32 
               
               
                 Test Sample 9 
                 80500 
                 22800 
                 28 
                 1.42 
                 3.3 
                 33 
               
               
                 Test Sample 10 
                 80000 
                 22400 
                 28 
                 1.39 
                 3.4 
                 34 
               
               
                 Test Sample 11 
                 80600 
                 22500 
                 28 
                 1.40 
                 3.5 
                 34 
               
               
                 Test Sample 12 
                 79750 
                 20700 
                 26 
                 1.29 
                 3.3 
                 32 
               
               
                 Test Sample 13 
                 80325 
                 19475 
                 24 
                 1.21 
                 3.1 
                 31 
               
               
                 Test Sample 14 
                 80600 
                 25600 
                 32 
                 1.59 
                 3.6 
                 36 
               
               
                 Test Sample 15 
                 80600 
                 28900 
                 36 
                 1.80 
                 3.8 
                 37 
               
               
                 Test Sample 16 
                 80600 
                 32400 
                 40 
                 2.01 
                 4.2 
                 37 
               
               
                 Test Sample 17 
                 80600 
                 36100 
                 45 
                 2.24 
                 4.8 
                 36 
               
               
                   
               
            
           
         
       
     
     As shown in Tables 2 and 3, it was confirmed that the Test Samples 1-17 having the insulator&#39;s dimensional ratio (Ha/La) equal to or less than 1.5 times the core portion&#39;s dimensional ratio (hd/ld) each had a higher Q value than the Comparative Examples 1-2 having the dimensional ratio (Ha/La) of the insulator exceeding 1.5 times the dimensional ratio (hd/ld) of the core portion. 
     Also, it was confirmed that the Test Samples 3-5 having the core portion&#39;s dimensional ratio (hd/ld) of 0.8 to 1.5 each had a Q value (of 29 or higher) higher than the Test Samples 1, 2, and 6. Likewise, it was confirmed that the Test Samples 9-11 and 14-17 having the core portion&#39;s dimensional ratio (hd/ld) of 0.6 to 1.0 each had a Q value (of 32 or higher) higher than the Test Samples 7, 8, 12, and 13. 
     Also, it was confirmed that the Test Samples 2-4 having the core portion&#39;s dimensional ratio (hd/ld) of 0.6 to 1.0 each had an L value (of 2.7 nH or higher) greater than the Test Samples 1, 5, and 6. 
     In addition, it was confirmed that the Test Samples 2-4 and 7-17 having the ratio (Sd/Sa) of the core portion&#39;s area (Sd) with respect to the insulator&#39;s area (Sa) of 22% to 45% each had a high L value of 2.7 nH or more. 
     The Test Sample 1 had a Q value higher than that of the Comparative Example 2 although their core portion areas were almost the same as each other because the core portion dimensional ratio (wd/ld) of the Test Sample 1 was greater than that of the Comparative Example 2. 
     The Test Sample 4, with the core portion&#39;s dimensional ratio (wd/ld) of about 1, had the highest Q value amonth the Test Samples 1-6. 
     Since the Test Samples 7-17 each had an insulator portion with insulating quality higher than the Test Samples 1-6 and thus the conductor dimensions of the Test Samples 7-17 may be formed to the largest extent possible, the Test Samples 7-17 may exhibit a high inductance value. Accordingly, the Q values may become 31 or higher. 
     The invention is not limited to the above described embodiments and various modification can be made. 
     For example, in the embodiments described above, the insulating layers and the via conductive members are alternately layered from the top surface side to the bottom surface side to fabricate the coil component. Alternatively the insulating layers and the via conductive members may be layered from the bottom surface side to the top surface side. 
     Each of the circumference sections of the coil portion may be layered in the coil axial direction. The production method is also applicable to the present invention. 
     In the above embodiment, the shape of the circumference section as viewed from the Z-axial direction is rectangular. Alternatively, the circumference section may be formed in a polygonal shape, and those shapes may have rounded corners to have the same advantageous effects. 
     While the coil axis of the coil component extends in the X-axial direction (width direction) in the above embodiment, the coil component may be formed such that the coil axis extends in the Z-axial direction (height direction) to obtain the same advantageous effects. 
     The insulator may provide the same advantageous effect whether it is formed of glass or resin and includes ferrite powder to the extent that the magnetic permeability thereof is 2 or less. The insulator with a relative permittivity of five or less can improve high frequency characteristics. The insulator with a relative permittivity of four or less can enhance the Q value at a high frequency by reducing the floating capacitance generated between the terminal electrodes. 
     Second Embodiment 
     While the electronic components equipped with the comb-tooth block portion have been described as the first embodiment, the comb-tooth block portion  24  is optional and the electronic components in accordance with some aspects of the present invention do not necessarily include the comb-tooth block portion  24 . Such electronic components will be described below as an exemplary variation. In the following exemplary arrangement, the ratio (Ha/La) of the height (Ha) of the insulator part  10  to the length (La) of the insulator is 1.5 times or less of the ratio (hd/ld) of the height (hd) between the inner peripheral portions of the circumference section Cn along the Z-axial direction with respect to the length (ld) between the inner peripheral portions of the circumference section Cn along the Y-axial direction. 
     The opening dimensional ratio (hd/ld) of the circumference section Cn may be, for example, 0.6 to 1.0. It should be noted that the opening dimensional ratio (Hd/ld) is not limited to the above range. Thus, it is possible to stably secure a high inductance value and Q value. 
     The ratio (Sd/Sa) of the area (Sd) partitioned by the inner circumferential portion of the circumferential section Cn with respect to the area (Sa) of the insulator portion as viewed from the coil axial direction (X-axial direction) may be, for example, 0.22 to 0.65 (22% to 65%). It should be noted that the ratio (Sd/Sa) is not limited to the above range. Thus, the inductance value of the coil component may be efficiently enhanced. 
     First Arrangement 
     The electronic components according to the first arrangement does not include any comb-tooth block portion. Thus, the coil portion may be laid out in a wider area in an insulator with a given volume as compared to the coil component having such a comb-tooth block portion and increase the opening area of the coil portion, thereby enhancing its L value and Q value. 
     The electronic component according to this arrangement enables its external electrodes to be disposed only on a single surface of the cuboid insulator thanks to absence of a comb-tooth block portion. Thus, the electronic component according to this arrangement may be a single-surface-mounted type component. The coil components according to the first embodiment is a three-surface-mounted type electronic component having its electrodes provided on the three surfaces  102 .  103 ,  104  of the rectangular insulator. However, the configuration is not limiting. The electronic component may be a single-surface-mounted type component having its external electrodes disposed only on a single surface of the insulator, as in this arrangement. Moreover, while the coil portion and the external electrodes are connected via the extended portions and the comb-tooth block portions in the first embodiment, the connections between the coil portion and the external electrodes in this arrangement are provided by connecting via conductive layers. 
     Next, the electronic components according to the first arrangement will be described with reference to  FIGS. 12-14 .  FIG. 12A  is a schematic perspective view of an electronic component according to the first arrangement of this embodiment  FIG. 12B  is an external perspective view of the electronic component of  FIG. 12A ;  FIG. 13A  is a schematic perspective side view of the electronic component of  FIG. 12A ;  FIG. 13B  is a schematic external side view of the electronic component of  FIG. 12B ; and  FIG. 14  is a schematic perspective top view of the electronic component of  FIG. 12B . In these drawings, the X-axis, Y-axis and Z-axis indicate three axial directions that are perpendicular to each other. 
     An electronic component  1100  according to this arrangement may be configured as a coil component that is surface-mounted on a substrate. The electronic component  1100  may include an insulator  1010 , an internal conductor  1020 , and an external electrode  1030 . 
     The insulator  1010  may include a top surface  1101 , a bottom surface  1102 , a first end surface  1103 , a second end surface  1104 , a first side surface  1105 , and a second side surface  1106 . The insulator  10  is made in a cuboid shape that has the width in the X-axial direction, the length in the Y-axial direction and the height in the Z-axial direction. The bottom surface  1102  may serve as a mounting surface. 
     The insulator  1010  may include a body  1011  and an upper portion  12 . The body  1011  may include the internal conductor  1020  thereinside and form a main part of the insulator  1010 . The upper portion  12  provides the top surface  1101  of the insulator  1010 . The insulator  1010  may be formed of the same material as the above embodiments. 
     The internal conductor  1020  may be provided inside the insulator  1010 . The internal conductor  1020  may include a plurality of pillared conductive members  1021 , a plurality of connecting conductive members  1022 , and a plurality of connecting via conductive layers V 1023 . The plurality of pillared conductive members  1021  and the plurality of connecting conductive members  1022  together form a coil portion  1020 L. The plurality of connecting via conductive layers V 1023  may be connected to the both ends of the coil portion  1020 L, respectively. 
     The plurality of pillared conductive members  1021  may be each formed in a substantially columnar shape with a central axis arranged in parallel with the Z-axial direction. The plurality of pillared conductive members  1021  may include two groups of the conductors that are arranged so as to face to each other in the substantially Y-axial direction. One of the two conductor groups is first pillared conductive members  10211 . The first pillared conductive members  211  are arranged in the X-axial direction at a predetermined interval The other of the two conductor groups is second pillared conductive members  10212 . The second pillared conductive members  212  are also arranged in the X-axial direction at a predetermined interval. 
     The substantially columnar shape herein may include any columnar shape of which cross section perpendicular to the axis (in the direction perpendicular to the central axis) is a circle, an ellipse, or an oval. For example, the substantially columnar shape may mean any prism whose cross section is an ellipse or an oval in which the ratio of the major axis to the minor axis is 3 or smaller. 
     The first pillared conductive members  10211  and the second pillared conductive members  10212  may be configured to have the same radius and the same height respectively. The illustrated example includes five of the first pillared conductive members  10211  and five of the second pillared conductive members  10212 . As will be further described later, the first and second pillared conductive members  10211 ,  10212  may be formed by stacking two or more via conductive members in the Z-axial direction. 
     Note that the reason why the pillared members have the substantially same radius is to prevent increase of resistance and this may be realized by reducing variation in the dimension of the pillared members as viewed in the same direction to 10% or smaller. Moreover the reason why the pillared members have the substantially same height is to secure stacking accuracy of the layers and this may be realized by reducing a difference in the height of the pillared members to, for example, 10 μm or smaller. 
     The plurality of connecting conductive members  1022  may include two groups of conductors that are formed in parallel with the XY plane and arranged so as to face to each other in the Z-axial direction. One of the two conductor group is first connecting conductive members  10221  that extend along the Y-axial direction and are arranged in the X-axial direction at a predetermined interval so as to connect between the first pillared conductive members  10211  and the second pillared conductive members  10212  respectively. The other of the two conductor group is second connecting conductive members  10222  that extend at a predetermined angle with the Y-axial direction and are arranged in the X-axial direction at a predetermined interval so as to connect between the first pillared conductive members  10211  and the second pillared conductive members  10212  respectively. The illustrated example includes five of the first connecting conductive members  10221  and five of the second connecting conductive members  10222 . 
     Referring aging to  FIG. 12 , the first connecting conductive members  10221  are each connected with upper ends of a predetermined pair of the pillared conductive members  10211 ,  10212 , and the second connecting conductive members  10222  are each connected with lower ends of a predetermined pair of the pillared conductive members  10211 ,  10212 . More specifically, the first and second pillared conductive members  10211 ,  10212  and the first and second connecting conductive members  10221 ,  10222  may be each connected to each other so as to form circumference sections Cn (C 1 -C 5 ) of the coil portion  1020 L and such that the circumference sections Cn form a rectangular helix in the X-axial direction. In this manner, provided inside the insulator  1010  is the coil portion  1020 L that has the central axis (a coil axis) in the X-axial direction and has an rectangular opening. 
     In this embodiment, the circumference sections Cn include five circumference sections C 1 -C 5 . The cross section of each of The circumference sections C 1 -C 5  may have a substantially same cross section. 
     The connecting via conductive layers V 1023  include first connecting via conductive layer V 10231  and second connecting via conductive layer V 10232 . The first connecting via conductive layer V 10231  may be coupled to a lower end of the first pillared conductive member  10211  that forms one end of the coil portion  1020 L, and the second connecting via conductive layer V 102312  may be coupled to a lower end of the second pillared conductive member  10212  that forms the other end of the coil portion  1020 L. The first and second connecting via conductive layers V 10231  and V 10232  each have a substantially circular cross-sectional shape along the plane orthogonal to the Z-axial direction. The cross section of the first and second connecting via conductive layers V 10231  and V 10232  each have the same shape and area as that of the pillared conductive member  1021 . 
     The external electrode  1030  may form an external terminal for surface mounting. The external electrode  30  may include first and second external electrodes  1031 ,  1032  that face to each other in the Y-axial direction. The first and second external electrodes  1031 ,  1032  may be formed only on the bottom surface  1102 . The bottom surface  1102  is one of the surfaces of the insulator  1010 . The external electrode  1030  may be formed outside the insulator  1010 . 
     The pillared conductive members  1021 , the connecting conductive members  1022 , and the connecting via conductive layer V 1023  may be formed of a metal such as Cu (copper), Al (aluminum), Ni (nickel) or the like. In this embodiment, these may be formed of copper or a copper alloy plated layer. The first and second external electrodes  1031 ,  1032  may be formed by, for example, Ni/Sn plating. 
       FIG. 15  is a schematic side view of the upside-down electronic component  1100 . As shown in  FIG. 15 , the electronic component  1100  may include a film layer L 1001  and electrode layers L 1002 -L 1006 . In the embodiment, the film layer L 001  and the electrode layers L 1002 -L 1006  may be stacked sequentially in the Z-axial direction from the top surface  1101  to the bottom surface  1102 . The number of the layers may not be particularly limited and may be six in this example. 
     The film layer L 1001  and the electrode layers L 1002 -L 1006  may include corresponding insulator  1010 , internal conductor  1020  and external electrode  1030 .  FIGS. 16A-16F  are schematic top views of the film layer L 1001  and the electrode layers L 1002 -L 1006  of  FIG. 15 . 
     The film layer L 1001  may be formed of the upper portion  12  that serves as the top surface  1101  of the insulator  1010  ( FIG. 16A ). The electrode layer L 1002  may include an insulating layer  10110  ( 10112 ) and the first pillared conductive members  211  ( FIG. 16B ). The insulating layer  10110  ( 10112 ) forms a part of the insulator  10110  (the body  1011 ). The electrode layer L 1003  may include the insulating layer  10110  ( 10113 ), and via conductive members V 1001  that form a part of the pillared conductive members  10211 ,  10212  ( FIG. 16C ). The electrode layer L 1004  may include the insulating layer  10110  ( 10114 ), the via conductive member V 1001 , and the second connecting conductive member  10222  ( FIG. 16D ). The electrode layer L 1005  may include the insulating layer  10110  ( 10115 ) and the connecting via conductive layers V 1023  (the first connecting via conductive layer V 10231  and the second connecting via conductive layer V 10232 )( FIG. 16E ). The electrode layer L 1006  may include the external electrodes  1030  (the first external electrode  1031  and the second external electrode  1032 ) ( FIG. 16F ). 
     The electrode layers L 1002 -L 1006  may be stacked in the height direction with bonding surfaces S 1 -S 4  (see  FIG. 15 ) interposed therebetween. Accordingly, the insulating layers  10110 , the via conductive members V 1001 , the connecting via conductive layers  1023  and the external electrodes  1030  also have boundaries in the height direction. The electronic component  1100  may be manufactured by the same build-up method as described in connection with the above embodiment in which the electrode layers L 10 a 02 -L 1006  are sequentially fabricated and layered in the stated order from the electrode layer L 1002 . 
     As described above, the electronic component  1100  according to the first arrangement may have a larger dimension (ld) of the core portion in the Y-axial direction thanks to absence of comb-tooth block portions. Thus, the coil portion  1020 L may have a larger opening area, thereby enhancing the L value and Q value. 
     Moreover, since the external electrodes  1030  serving as external terminals for surface mounting are provided only on the single surface of the electronic component  1100 , a formation of solder fillet may be prevented when solder-mounting the electronic component  1100 , thereby enabling a high-density mounting. 
     In addition, the coil portion  1020 L and the external electrodes  1030  are connected through the connecting via conductive layers V 1023 , the path of electric current from the external electrodes to the coil portion  1020  may be shortened as compared to the embodiments with comb-tooth block portions. Thus, an electronic component  1100  generating less noise and having less degradation in characteristics may be obtained. 
     Second Arrangement 
     The coil components according to the first arrangement have the connecting via conductive layers V 1023  having a substantially circular cross-sectional shape along the plane orthogonal to the Z-axial direction. However, the cross-sectional shape is not limiting. The connecting via conductive layers may have a oval cross-sectional shape, as in the second arrangement described below. Structures different from the first arrangement will be hereinafter mainly described The same reference numerals are given to the same elements as those of the first arrangement, and the description thereof will be omitted or simplified. The coil component according to this arrangement may also have a coil portion having a large opening area like the first arrangement, thereby enhancing the L value and Q value. 
     Next, the electronic components according to the second arrangement will be described with reference to  FIGS. 17-19 .  FIG. 17  is a schematic perspective view of an electronic component according to the second arrangement.  FIG. 18  is a schematic side view of the electronic component of  FIG. 17 .  FIG. 19  is a schematic top view of the electronic component of  FIG. 17 . 
     An electronic component  2100  according to this arrangement may be configured as a coil component that is surface-mounted on a substrate. The electronic component  2100  may include an insulator  2010 , an internal conductor  2020 , and an external electrode  1030 . 
     The insulator  2010  may include a body  2011  and an upper portion  12 . The body  2011  may include the internal conductor  2020  thereinside and form a main part of the insulator  2010 . 
     The insulator  2010  may include a top surface  2101 , a bottom surface  2102 , a first end surface  2103 , a second end surface  2104 , a first side surface  2105 , and a second side surface  2106 . The insulator  10  is made in a cuboid shape that has the width in the X-axial direction, the length in the Y-axial direction and the height in the Z-axial direction. 
     The internal conductor  2020  may be provided inside the insulator  2010 . The internal conductor  2020  may include a plurality of pillared conductive members  1021  and a plurality of connecting conductive members  1022 . The plurality of pillared conductive members  1021  and the plurality of connecting conductive members  1022  together form a coil portion  1020 L. The plurality of connecting via conductive layers V 2023  may be connected to the both ends of the coil portion  1020 L, respectively. 
     The connecting via conductive layers V 2023  include first connecting via conductive layer V 20231  and second connecting via conductive layer V 20232 . The first connecting via conductive layer V 20231  may be coupled to a lower end of the first pillared conductive member  10211  that forms one end of the coil portion  1020 L, and the second connecting via conductive layer V 20232  may be coupled to a lower end of the second pillared conductive member  10212  that forms the other end of the coil portion  1020 L. The first and second connecting via conductive layers V 20231  and V 20232  each have a oval cross-sectional shape along the plane orthogonal to the Z-axial direction. The cross section of the first and second connecting via conductive layers V 20231  and V 20232  each have an area larger than that of the pillared conductive member  1021 . In other words, when the pillared conductive member  1021  and the connecting via conductive layers V 2023  are projected to the XY plane, the substantially circular projection of the pillared conductive member  1021  is entirely included in the oval projection of the connecting via conductive layers V 2023 . 
     The external electrode  1030  may form an external terminal for surface mounting. The external electrode  30  may include first and second external electrodes  1031 ,  1032  that face to each other in the Y-axial direction. The first and second external electrodes  1031 ,  1032  may be formed only on the bottom surface  2102 . The bottom surface  1102  is one of the surfaces of the insulator  2010 . 
     As described above, the coil portion  1020 L and the external electrodes  1030  may contact with each other in a larger area since the connecting via conductive layers V 2023  each have a oval cross-sectional shape larger than that of the pillared conductive member  1021  that forms a part of the coil portion  1020 L. 
     Third Arrangement 
     The coil components according to the above arrangements may include one or more dummy via conductive layers in the same layer as the connective via conductive layers V 1023 , V 2023 , as in the second arrangement described below. The dummy electrodes may be configured not to electrically connect the coil portion  1020 L and the external electrodes  1030 . A plurality of dummy via conductive layers may be formed in the insulator in contact with the external electrodes  1030 . The dummy via conductive layers may increase the adhesion strength between the external electrodes  1030  and the insulator  1010 . Such dummy via conductive layers are applicable to each of the above embodiments and above arrangements. 
       FIG. 20  is a schematic perspective view of an electronic component according to the third arrangement.  FIG. 21  is a schematic side view of the electronic component of  FIG. 20 .  FIG. 22  is a schematic top view of the electronic component of  FIG. 20 . The coil component according to the third arrangement include dummy via conductive layers in addition to the elements of the first arrangement. The same numerals are given to the same elements as those of the first arrangement, and the description thereof will be omitted. 
     An electronic component  3100  according to this arrangement may be configured as a coil component that is surface-mounted on a substrate. The electronic component  3100  may include an insulator  3010 , an internal conductor  1020 , and an external electrode  1030 . 
     The insulator  3010  may include a body  3011  and an upper portion  12 . The body  3011  may include the internal conductor  1020  and dummy via conductive layers  3040  and form a main part of the insulator  3010 . 
     The insulator  3010  may include a top surface  3101 , a bottom surface  3102 , a first end surface  3103 , a second end surface  3104 , a first side surface  3105 , and a second side surface  3106 . The insulator  10  is made in a cuboid shape that has the width in the X-axial direction, the length in the Y-axial direction and the height in the Z-axial direction. 
     The dummy via conductive layers  3040  may be formed of a plurality of projections provided on the internal surface of the external electrodes  1030  that face the bottom surface  3102  of the rectangular insulator  3010 . As shown in  FIG. 21 , the plurality of projections are each configured to penetrate the bottom surface  3102  into the insulator  3010 . The tip ends of the dummy via conductive layers  3040  each face the internal conductor  1020  via the insulating material of the insulator  3010 . Accordingly, tip ends of the dummy via conductive layers  3040  does not contact with the coil portion  1020 L. 
     The dummy via conductive layers  3040  may be formed in the same layer as the connecting via conductive layers V 1023 . The plurality of dummy via conductive layers  3040  may include two groups of the conductive layers that are arranged so as to face to each other in the Y-axial direction. The first dummy via conductive layers  3041  form one group of the two conductive layers. The first dummy via conductive layers  3041  may be provided in the four corners of the first external electrode  1031  having a rectangular shape in the XY plane. The first dummy via conductive layers  3042  form the other group of the two conductive layers. The second dummy via conductive layers  3042  may be provided in the four corners of the second external electrode  1032  having a rectangular shape in the XY plane. The dummy via conductive layers  3040  are electrically insulated from the internal conductor  1020  by the insulating layer forming the insulator  3011 . 
     In this exemplary variation, the dummy via conductive layers  3030  may increase the adhesion strength between the external electrodes  1030  and the insulator  3011 . The external electrodes  1030  may be produced, for example, by electroplating, subsequently to forming a seed layer and a resist pattern having an opening in a similar manner to the production of the conductive pattern of the internal conductor in the above embodiment. The production process of the external electrodes  1030  may cause the dummy via conductive layers  3040  to be firmly adhered to the external electrodes  1030 , thereby increasing the adhesion strength between the external electrodes  1030  and the insulator  3011 . 
     Electronic Component Characteristics 
     The present invention is not limited to the above embodiments, but may be configured as shown in  FIGS. 23 and 24 .  FIGS. 23 and 24  are schematic perspective views of the electronic components according to the above embodiments.  FIGS. 23A-23C  each illustrate an electronic component having the comb-tooth block portions  24 .  FIGS. 24A-24  C each illustrate an electronic component that does not have the comb-tooth block portions  24 . The same numerals are given to the same elements as those of the above embodiments. 
     The electronic components in  FIG. 23  and  FIG. 24  each have the same external dimensions. The ratio (Ha/La) of the height (Ha) to the length (La) of the insulator is 1.5 times or less of the ratio (hd/ld) of the height (hd) between the inner peripheral portions of the circumference section Cn along the Z-axial direction with respect to the length (ld) between the inner peripheral portions of the circumference section Cn along the Y-axial direction. 
       FIG. 23A  is a schematic perspective view of the electronic component  100  according to the first embodiment.  FIG. 23B  is a schematic perspective view of the electronic component  4100 . according to the first embodiment. Unlike the electronic component  100 , the electronic component  4100  does not include the extended portion  23 . The electronic component  4100  is configured such that the external electrodes  20  and the coil portion  1020 L are connected through the connecting via conductive layers V 1023  like the second embodiment.  FIG. 23C  is a schematic perspective view of the electronic component  5100  in which the comb-tooth block portions  24  is shorter in the Y-axial direction and thus the distance between the coil portion  1020 L and the comb-tooth block portions  24  is larger as compared to the electronic component  3100  shown in  FIG. 23B . The side margin (lb) between the coil portion  20 L and the end surface of the insulator in the Y-axial direction (left-right direction) is 45 μm in each of the electronic components in  FIGS. 23A-23C . 
       FIGS. 24A-24C  each illustrate an electronic component corresponding to the electronic component  1100  according to the second embodiment (the first arrangement). Their fundamental configurations are same except for the side margins ( 1 b) in the Y-axial direction. The side margin  1 b of the electronic component  1100 A shown in  FIG. 24A  is 45μm. The side margin  1 b of the electronic component  1100 B shown in  FIG. 24B  is 20 μm. The side margin  1 b of the electronic component  1100 C shown in  FIG. 24C  is 10 μm. 
       FIG. 25  shows the inductance (L value) properties of each of the electronic components illustrated in  FIGS. 23A-23C  and  FIGS. 24A-24C .  FIG. 26  shows the Q value properties of each of the electronic components illustrated in  FIGS. 23A-23C  and  FIGS. 24A-24C . In  FIGS. 25 and 26 , the numeral  23 A,  23 B,  23 C,  24 A,  24 B, and  24 C in the abscissa each indicate the electronic components illustrated in  FIGS. 23A, 23B, 23C, 24A, 24B, and 24C , respectively. In  FIGS. 25 and 26 , the inductances and Q values of each of those electronic components are plotted. 
     As shown in  FIGS. 25 and 26 , each of the electronic components has the L value of 3 nH or more and the Q value of 30 or more. Thus, those electronic components achieved such a high inductance value and Q value. The inductance properties and Q value properties may be further enhanced by enlarging the opening (core) of the coil portion. 
       FIG. 27A-27D  are presented to compare the regions available for the internal conductors depending on the configurations of electronic components. The electronic components in  FIGS. 27A-27D  each have the external dimensions of 200 μm (width)×400 μm (length)×200 μm (height).  FIG. 27B  is a schematic external side view of the single-surface-mounting type electronic component  1100  according to the second embodiment (first arrangement).  FIG. 27C  is a schematic perspective side view of the three-surface-mounting type electronic component  100  according to the first embodiment (first arrangement).  FIG. 27D  is a schematic external side view of a conventional five-surface-mounting type electronic component  7100 . The numerals  7030  indicate external electrodes. In each of the electronic components, the external electrodes have the thickness of 10 μm. In the example shown in  FIG. 27A , the external shape of the electronic component is identical that of the insulator thereof. As described below, the proportions of the insulators in the corresponding electronic components shown in  FIGS. 27B-27D  are calculated by setting the volume of the insulator  6010  to 100%. 
     The proportion of the insulator  1010  in the single-surface-mounting type electronic component  1100  as shown in  FIG. 27B  is 95%. The proportion of the insulator  10  in the three-surface-mounting type electronic component  100  as shown in  FIG. 27C  is 84%. The proportion of the insulator in the five-surface-mounting type electronic component  7100  as shown in  FIG. 27D  is 76.95%. As the proportion of the insulator in an electronic component increases, the area in the insulator in which an internal conductor can be arranged may be increased as well. Accordingly, the single-surface-mounting type electronic component  1100  and the three-surface-mounting type electronic component  100  each have a larger area available for the internal conductor as compared to the conventional five-surface-mounting type electronic component  7100 , thereby enlarging the opening (core) of the coil portion. Thus, the L value and Q value may be enhanced.