Coil component and electronic device

In an embodiment, a coil component includes: a core 10 having a pillar part 24, and a hollow space 22 around the pillar part 24; a coil conductor 40 having a spiral part 42 placed around the pillar part 24, and a lead part 48a or 48b led out from the spiral part 42 toward the bottom face 28 of the core 10, which lead part includes an end part 46a or 46b extending in parallel with the bottom face 28 and serves as an external terminal 49a or 49b; and an insulated terminal 60 electrically insulated from the coil conductor 40, which is provided on at least the bottom face 28; wherein the total base area of the bottom part 72 of the dummy terminal 60, on the bottom face 28, is greater than the total base area of the external terminals 49a, 49b.

BACKGROUND

Field of the Invention

The present invention relates to a coil component and an electronic device.

Description of the Related Art

As applications of coil components widen, there is a demand for coil components offering high durability against vibration and impact. For example, it is known that a coil component would offer improved mounting strength when mounted on a circuit board if, on its core in which a coil conductor is housed, a dummy terminal is installed (refer to Patent Literature 1, for example).

BACKGROUND ART LITERATURES

SUMMARY

However, the coil component described in Patent Literature 1 may suffer a deformed or displaced coil conductor, or the coil conductor may have a broken wire in some cases, when large vibration or impact is applied to the coil component.

The present invention was created in light of the aforementioned problems, and its object is to improve durability against vibration and impact.

Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.

The present invention is a coil component, comprising: a core having a pillar part, and a hollow space around the pillar part, inside (the core forms an outer part and inside is the pillar and the hollow space around that); a coil conductor having a spiral part placed in the hollow space around the pillar part (a space remaining in the hollow space after placing therein the coil conductor may also be referred to as “a hollow space” depending on the context), and a lead part which is led out from the spiral part toward the principal outer surface constituting the bottom face of the core, and which includes an end part that extends in parallel with the bottom face of the core and serves as an external terminal; and a terminal electrically insulated from the coil conductor (hereinafter referred to as “dummy terminal” or “insulated terminal”), which is installed on the core in a manner covering at least the bottom face of the core; wherein the total base area of the bottom part of the dummy terminal on the bottom face of the core is greater than the total base area of the external terminal.

The aforementioned constitution may be such that, of the lead part of the coil conductor, the connection part that connects the spiral part with the end part is bonded to at least the core with an adhesive.

The aforementioned constitution may be such that the external terminal of the coil conductor is bonded to the bottom face of the core with an adhesive.

The aforementioned constitution may be such that there are multiple dummy terminals, and the external terminal of the coil conductor is placed on the first side of the bottom face of the core, while the bottom parts of the multiple dummy terminals are placed on the opposing second side and third side of the bottom face of the core.

The aforementioned constitution may be such that the dummy terminal is shaped to have: the bottom part positioned on the bottom face of the core; a top part positioned on the top face opposite the bottom face, of the core; and a side part coupling the bottom part and the top part.

The aforementioned constitution may be such that the dummy terminal has an opening that extends from the top part to the side part, and an adhesive is filled in the opening.

The aforementioned constitution may be such that the dummy terminal is shaped as a box that has: the bottom part positioned on the bottom face of the core; a top part positioned on the top face opposite the bottom face, of the core; three side parts coupling the bottom part and the top part; and an opening in which the core is stored.

The aforementioned constitution may be such that the dummy terminal is shaped so that its top part is larger than its bottom part in area.

The aforementioned constitution may be such that the top part of the dummy terminal covers all of the top face of the core.

The aforementioned constitution may be such that the dummy terminal is shaped to have: the bottom part positioned on the bottom face of the core; and a side part coupled to the bottom part and positioned on a side face that intersects the bottom face, of the core.

The present invention is an electronic device equipped with a coil component according to any of the foregoing, and a circuit board on which the coil component is mounted.

The aforementioned constitution may be such that the coil conductor has two of the lead parts, and one of the two lead parts is led out from the spiral part on the top face side of the core, while the other lead part is led out from the spiral part on the bottom face side of the core, where a higher voltage is applied to a first pad on the circuit board to which the external terminal of the one lead part is connected, than that to a second pad on the circuit board to which the external terminal of the other lead part is connected.

According to the present invention, durability against vibration and impact can be improved.

DESCRIPTION OF THE SYMBOLS

DETAILED DESCRIPTION OF EMBODIMENTS

Examples of the present invention are explained below by referring to the drawings.

FIG. 1Ais a perspective view,FIG. 1Bis a plan view from the bottom face side, andFIG. 1Cis a perspective cross-sectional view along A-A inFIG. 1A, of the coil component100pertaining to Example 1. It should be noted that, in the following explanations, the vertical direction is specified on the assumption that, when the coil component100is mounted on a circuit board, the circuit board is positioned vertically below the coil component100. Also, while a solder is applied to the end parts46a,46bof the coil conductor40and the bottom part72of the dummy terminal60, the solder is not illustrated in the drawings, except forFIGS. 3C, 4, 12B and 12C. As shown inFIGS. 1A through 1C, the coil component100in Example 1 is an inductor element comprising a core10, a coil conductor40, and a dummy terminal60.

The core10is formed by a top core12and a bottom core14, which are joined with an adhesive made of a thermosetting resin, etc., for example. The core10has a top part16, a bottom part18, and a side part20, as well as a hollow space22inside. The core10has a rectangular shape whose one side is approx. 13 mm to 17 mm long in plan view, and which has rounded corners and a height of 6 mm to 8.5 mm, for example. The core10is open on one side face side so that the hollow space22is exposed to the exterior. The core10has a pillar part24inside the hollow space22. The pillar part24extends vertically between the top part16and the bottom part18. It should be noted that a glass film of approx. 5 μm to 50 μm in thickness may be provided on the outer surface of the core10. This improves the insulation property and anti-rust property.

FIGS. 2A and 2Bare perspective views of the top core12, whileFIGS. 2C and 2Dare perspective views of the bottom core14.FIGS. 2A and 2Care perspective views from above, whileFIGS. 2B and 2Dare perspective views from below. As shown inFIGS. 2A and 2B, the top core12has a lid17that constitutes the top part16, and a side part20a, and a hollow space22ais formed inside. A cylindrically-shaped pillar part24ais formed inside the hollow space22a. The corners of the lid part17along the side part20aand pillar part24aare chamfered to rounded shapes. This improves durability against vibration and impact. The height of the side part20ais roughly the same as that of the pillar part24a, which is approx. 3 mm to 5 mm, for example. The diameter of the pillar part24ais approx. 5 mm to 8 mm, for example. The top core12is formed by a magnetic material; or specifically, it is formed by a ferrite material or metal magnetic material, for example.

As shown inFIGS. 2C and 2D, the bottom core14has a base part19that constitutes the bottom part18, and a side part20b, and a hollow space22bis formed inside. A cylindrically-shaped pillar part24bis formed inside the hollow space22b. The corners of the base part19along the side part20band pillar part24bare chamfered to rounded shapes. The height of the side part20bis roughly the same as that of the pillar part24b, which is shorter than the height of the side part20aand pillar part24aof the top core12, and is approx. 2 mm to 2.5 mm, for example. The diameter of the pillar part24b, which is roughly the same as that of the pillar part24aof the top core12, is approx. 5 mm to 8 mm, for example. The bottom core14is formed by a magnetic material; or specifically, it is formed by a ferrite material or metal magnetic material identical to the material of the top core12, for example.

As shown inFIGS. 1A through 1C and 2A through 2D, the side part20aof the top core12is joined to the side part20bof the bottom core14to form the side part20of the core10, while the pillar part24aof the top core12is joined to the pillar part24bof the bottom core14to form the pillar part24of the core10. It should be noted that the bottom core14may be formed only by the flat-shaped base part19on which the side part20band pillar part24bare not formed, and the core10may be formed by joining the side part20aand pillar part24aof the top core12to the flat-shaped base part19of the bottom core14.

Next, the coil conductor40is explained usingFIGS. 3A through 3Cin addition toFIGS. 1A through 1C.FIGS. 3A through 3Care perspective views of the coil conductor40.FIG. 3Ais a perspective view from above, andFIG. 3Bis a perspective view from below, of the coil conductor40, whileFIG. 3Cis a perspective view showing a solder80provided to end parts46a,46b. The coil conductor40has a spiral part42which is placed around the pillar part24inside the hollow space22of the core10, as well as lead parts48a,48bwhich are led out from the spiral part42toward the bottom face28of the core10, and include a pair of end parts46a,46bextending in parallel with the bottom face28of the core10. Also, the lead part48aincludes a connection part44athat connects the spiral part42with the end part46a, while the lead part48bincludes a connection part44bthat connects the spiral part42with the end part46b. The lead part48ais led out from the spiral part42on the top part16side of the core10, while the lead part48bis led out from the spiral part42on the bottom part18side of the core10.

An adhesive82is provided between the spiral part42and the core10, and the spiral part42and the core10are bonded together with the adhesive82. The adhesive82is a thermosetting resin, for example. By using a thermosetting resin for the adhesive82, the heat resistance and bonding strength can be improved. The width W of the coil conductor40is approx. 2.0 mm to 3.2 mm, for example. The coil conductor40is constituted by a conductive wire (such as copper (Cu) wire) covered with an insulating sheath (such as polyamide imide). The coil conductor40is a flat wire coil, for example, but it may also be a round wire coil. A solder80used for mounting the coil component100on a circuit board is provided to the base faces of the end parts46a,46b. The solder80has a composition of Sn-3Ag-0.75Cu, for example. As a result, the end parts46a,46bserve as external terminals49a,49bon which the solder80used for mounting the coil component100on a circuit board is provided. The solder80may be provided not only to the base faces of the end parts46a,46b, but also to parts of the connection parts44a,44bon their end part46a,46bsides. This way, the coil component100can be mounted on a circuit board more securely.

Next, the dummy terminal60is explained usingFIG. 4in addition toFIGS. 1A through 1C.FIG. 4is a perspective view of the dummy terminal60. The dummy terminal60is electrically insulated from the coil conductor40and has virtually no contribution to the electrical characteristics of the coil component100. The dummy terminal60extends from the top face26, to the bottom face28, via the side face30, of the core10, and is installed on the core10. It should be noted that the bottom face28of the core10constitutes the principal outer surface of the core10, while the top face26is the face opposite the bottom face28and the side face30is the face connecting to the top face26and the bottom face28. As a result, the dummy terminal60has a shape (roughly U-shape) that has a top part70positioned on the top face26, a bottom part72positioned on the bottom face28, and a side part74coupling the top part70and the bottom part72and positioned on the side face30, of the core10.

The dummy terminal60is positioned on the side face30of the core10opposite the side on which the lead parts48a,48bof the coil conductor40are led out, and is installed on the core10. An adhesive82is provided between the side part74of the dummy terminal60and the core10, and the side part74and the core10are bonded together with the adhesive82. It should be noted that the top part70and the core10may be bonded together with the adhesive82. The dummy terminal60is formed by a copper (Cu) or copper (Cu) alloy plated with nickel (Ni) and tin (Sn), for example, but it may also be formed by other metal. The solder80used for mounting the coil component100on a circuit board is provided on the base face of the bottom part72of the dummy terminal60. The solder80may be provided not only to the base face of the bottom part72of the dummy terminal60, but also to parts of the side part74of the dummy terminal60on its bottom part72side. This way, the coil component100can be mounted on a circuit board more securely.

The width W of the dummy terminal60is approx. 5 mm to 9 mm, for example, and larger than the width W of the coil conductor40. The base area S1(cross-hatched portion inFIG. 1B) of the bottom part72of the dummy terminal60is larger than the total sum of the base areas (such as the base areas of the end parts46a,46b) S2a, S2b(cross-hatched portions inFIG. 1B) of the external terminals49a,49b(S1>S2a+S2b).

As described above, according to Example 1, the total base area S1of the bottom part72of the dummy terminal60is larger than the total base area (S2a+S2b) of the external terminals49a,49b(S1>S2a+S2b). If the total base area S1of the bottom part72of the dummy terminal60is small, the external terminals49a,49bmay receive a considerable mechanical stress from the impact that generates when the coil component100is mounted on a circuit board, or vibration that generates after the mounting, and the coil conductor40may be damaged as a result. By increasing the total base area S1of the bottom part72of the dummy terminal60, however, more of the mechanical stress from vibration or impact is distributed over the dummy terminal60, and the mechanical stress applied to the external terminals49a,49bcan be reduced. Consequently, durability of the coil component100against vibration or impact applied to it, can be improved.

It should also be noted that, although the coil component100generates heat as it operates, the generated heat can effectively be dissipated or released through the bottom part of the dummy terminal60, i.e., the property, of the coil component100, of dissipating heat to the circuit board on which it is mounted, can be improved by increasing the total base area S1of the bottom part72of the dummy terminal60.

Also, according to Example 1, the external terminals49a,49bof the coil conductor40are placed on a side32side of the bottom face28of the core10, while the bottom part72of the dummy terminal60is placed on a side34side opposite the side32, of the bottom face28of the core10, as shown inFIG. 1B. This way, the mechanical stress from vibration or impact can be distributed more effectively to the external terminals49a,49band to the dummy terminal60, so durability improves further.

From the viewpoint of reducing the mechanical stress applied to the external terminals49a,49b, the total base area of the bottom part72of the dummy terminal60is preferably 1.5 times or more, or more preferably twice or more, or most preferably three times or more, the total base area of the external terminals49a,49b.

As shown inFIG. 1C, the bottom part72of the dummy terminal60may not be bonded to the core10with an adhesive. Since the bottom face28of the core10is a mounting surface which is mounted on a circuit board, not bonding the bottom part72of the dummy terminal60to the core10with an adhesive prevents contamination of the base faces of the external terminals49a,49bof the coil conductor40due to the adhesive, and mounting failure can be prevented as a result.

Preferably the thickness of the solder80provided to the end parts46a,46bof the coil conductor40is greater than the thickness of the solder80provided to the bottom part72of the dummy terminal60. This prevents the external terminals49a,49bof the coil conductor40from not being connected to the pads on the circuit board when the coil component100is mounted on a circuit board. To provide an example, preferably the thickness of the solder80provided to the end parts46a,46bof the coil conductor40is 3 μm to 30 μm. This is to ensure wettability of solder. Also, preferably the difference between the thickness of the solder80provided to the end parts46a,46bof the coil conductor40, and the thickness of the solder80provided to the bottom part72of the dummy terminal60, is 20 μm or less. This is to ensure balanced wettability of solder at the time of mounting.

FIG. 5is a perspective view of a coil component200pertaining to Example 2. As shown inFIG. 5, the coil component200in Example 2 is such that, of the lead parts48a,48bof the coil conductor40, the connection parts44a,44bare bonded at least to the core10with an adhesive84. For example, the connection part44ais bonded to the core10and the spiral part42with the adhesive84, while the connection part44bis bonded to the core10with the adhesive84. For the adhesive84, a thermosetting resin, photosetting resin, or any of various other adhesive materials may be used; however, the heat resistance and bonding strength can be improved by using a thermosetting resin. The remaining constitutions are the same as those in Example 1 and therefore not explained.

According to Example 2, the connection parts44a,44bof the coil conductor40are bonded at least to the core10with the adhesive84. This prevents the connection parts44a,44bfrom deforming, even when a mechanical stress is applied externally to the connection parts44a,44b. As a result, durability against vibration or impact can be improved.

From the viewpoint of preventing the connection parts44a,44bfrom deforming, preferably the connection part44aincluded in the lead part48athat has been led out from the spiral part42on the top part16side of the core10, is bonded to the core10and spiral part42with the adhesive84.

FIG. 6is a perspective view of a coil component300pertaining to Example 3. As shown inFIG. 6, the coil component300in Example 3 is such that the end parts46a,46bof the coil conductor40are bonded to the bottom face28of the core10with the adhesive84. In other words, the external terminals49a,49bof the coil conductor40are bonded to the bottom face28of the core10with the adhesive84. The remaining constitutions are the same as those in Example 1 and therefore not explained.

According to Example 3, the external terminals49a,49bof the coil conductor40are bonded to the bottom face28of the core10with the adhesive84. This prevents the external terminals49a,49bfrom deforming, even when a mechanical stress is applied externally to the external terminals49a,49b. As a result, durability against vibration or impact can be improved. It should be noted that, to prevent a mounting failure from occurring due to the adhesive84, preferably the adhesive84is kept from oozing out of the space between the external terminals49a,49bof the coil conductor40and the bottom face28of the core10.

FIG. 7Ais a perspective view,FIG. 7Bis a perspective cross-sectional view along A-A inFIG. 7A, andFIG. 7Cis a perspective view of a dummy terminal62, of a coil component400pertaining to Example 4. As shown inFIGS. 7A through 7C, the coil component400in Example 4 is such that the dummy terminal62has an opening76that extends from the top part70to the side part74. In other words, the opening76is formed over a position that includes the corners of the dummy terminal62between the top part70and the side part74. The opening76is filled with an adhesive86. Accordingly, the adhesive86not only bonds the dummy terminal62and the core10, but it is also applied on the side face of the dummy terminal62at the opening76. The adhesive86may be a thermosetting resin or photosetting resin, or any other adhesive material. The remaining constitutions are the same as those in Example 1 and therefore not explained.

According to Example 4, the dummy terminal62has the opening76that extends from the top part70to the side part74. The opening76is filled with the adhesive86. By thus filling the adhesive86in the opening76provided in the dummy terminal62, the side face portion of the opening76contributes to bonding, and the bonding area between the dummy terminal62and the core10increases as a result. This allows for secure bonding of the dummy terminal62to the core10. Secure bonding of the dummy terminal62to the core10helps achieve the effect of distributing the mechanical stress from vibration or impact to the external terminals49a,49band to the dummy terminal62. As a result, durability of the coil component400against vibration or impact applied to it, can be improved.

Additionally, filling the adhesive86in the opening76provided in the dummy terminal62makes it possible to confirm, from the exterior, that the dummy terminal62is bonded to the core10with the adhesive86. This allows for easy inspection, based on appearance, of the dummy terminal62for non-attachment of adhesive and other defects.

Also, according to Example 4, the opening76extends from the top part70, to the side part74, of the dummy terminal62. This mitigates the stress that generates in the dummy terminal62when the dummy terminal62is fitted onto the core10. It also improves the ease of bending the top part70of the dummy terminal62with respect to its side part74.

FIG. 8Ais a perspective view, andFIG. 8Bis a plan view from the bottom face side, of a coil component500pertaining to Example 5. As shown inFIGS. 8A and8B, the coil component500in Example 5 is such that multiple dummy terminals60a,60bare installed on the core10. The dummy terminals60a,60bare provided, in a manner opposing each other, on the side faces of the core10, which intersect the side face of the core10on which the lead parts48a,48bof the coil conductor40have been led out. This means that the external terminals49a,49bof the coil conductor40are placed on the side defined by the side32side of the bottom face28of the core10, while the bottom parts72a,72bof the dummy terminals60a,60bare placed on the side defined by the side36,38of the bottom face28of the core10, respectively, which intersect the side32and are opposed to each other. The total sum (S1a+S1b) of the base areas S1a, S1b(cross-hatched portions) of the bottom parts72a,72bof the dummy terminals60a,60bis larger than the total sum of the base areas S2a, S2b(cross-hatched portions) of the external terminals49a,49b(S1a+S1b>S2a+S2b). The remaining constitutions are the same as those in Example 1 and therefore not explained.

According to Example 5, multiple dummy terminals60a,60bare provided. Even in this case, durability of the coil component500against vibration or impact applied to it can be improved, just like in Example 1, by making the total base area (S1a+S1b) of the bottom parts72a,72bof the multiple dummy terminals60a,60blarger than the total base area (S2a+S2b) of the external terminals49a,49b.

Also, according to Example 5, the external terminals49a,49bof the coil conductor40are placed on the side32side of the bottom face28of the core10, while the bottom parts72a,72bof the multiple dummy terminals60a,60bare placed on the opposing sides36,38of the bottom face28of the core10, respectively. Because of this, the mechanical stress from vibration or impact applied to the coil component500can be effectively distributed to the external terminals49a,49band to the dummy terminals60a,60b, and therefore durability improves further. It should be noted that, from the viewpoint of distributing mechanical stress, preferably the bottom parts72a,72bof the dummy terminals60a,60bare provided in symmetry with respect to the center line between the sides36,38.

FIG. 9Ais a perspective view, andFIG. 9Bis a perspective cross-sectional view along A-A inFIG. 9A, of a coil component600pertaining to Example 6. As shown inFIGS. 9A and 9B, the coil component600in Example 6 is such that the top part70of the dummy terminal60has a larger shape compared to the bottom part72. In other words, the area of the top part70of the dummy terminal60is larger than the area of the bottom part72. The remaining constitutions are the same as those in Example 1 and therefore not explained.

In Example 1, the bottom part72of the dummy terminal60had a shape of a larger area compared to the top part70; as in Example 6, however, the top part70of the dummy terminal60may have a shape having a larger area compared to the bottom part72. When the top part70of the dummy terminal60has a larger area than the bottom part72, the electric field generated by the coil conductor40can be effectively shielded by connecting the dummy terminal60to ground.

It should be noted that, from the viewpoint of shielding the electric field, preferably the top part70of the dummy terminal60covers at least one-half, or more preferably at least two-thirds, or most preferably all, of the top face26of the core10.

FIG. 10Ais a perspective view,FIG. 10Bis a plan view from the bottom face side, andFIG. 10Cis a perspective view of a dummy terminal64, of a coil component700pertaining to Example 7. As shown inFIGS. 10A through 10C, the coil component700in Example 7 is such that the dummy terminal64is shaped as a box that has a top part70, a bottom part72, and three side parts74that couple the top part70and the bottom part72. The core10is stored inside the box-shaped dummy terminal64. In other words, all of the top face26of the core10is covered by the top part70of the dummy terminal64. Also, all of the side face30of the core10is covered by the side parts74of the dummy terminal64. The remaining constitutions are the same as those in Example 1 and therefore not explained.

According to Example 7, the dummy terminal64is shaped as a box that has a top part70positioned on the top face26, a bottom part72positioned on the bottom face28, and three side parts74coupling the top part70and the bottom part72and positioned on the side face30, of the core10, as well as an opening in which the core10is stored. Because the core10is thus stored in the box-shaped dummy terminal64, durability of the coil component700against vibration or impact applied to it can be improved further. Additionally, covering the top face26and side face30of the core10with the dummy terminal64allows the heat generated by the coil conductor40to dissipate better.

Also, according to Example 7, the top part70of the dummy terminal64covers all of the top face26of the core10. As a result, the electric field generated by the coil conductor40can be shielded more effectively.

FIG. 11Ais a perspective cross-sectional view, andFIG. 11Bis a perspective view of a dummy terminal66, of a coil component800pertaining to Example 8. As shown inFIGS. 11A and 11B, the coil component800in Example 8 has a shape (roughly L-shape) that has a bottom part72positioned on the bottom face28, and a side part74coupled to the bottom part72and positioned on the side face30, of the core10. The remaining constitutions are the same as those in Example 1 and therefore not explained.

In Example 1, the dummy terminal60illustrated was shaped to have a top part70, a bottom part72, and a side part74coupled to the top part70and the bottom part72, while in Example 7, the dummy terminal64illustrated as shaped as a box having a top part70, a bottom part72, and three side parts74coupled to the top part70and the bottom part72. However, the present invention is not limited to the foregoing and, as shown in Example 8, the dummy terminal66may be shaped to have a bottom part72and a side part74coupled to the bottom part72.

FIG. 12Ais a plan view,FIG. 12Bis a cross-sectional view along A-A inFIG. 12A, andFIG. 12Cis a cross-sectional view along B-B inFIG. 12A, of an electronic device900pertaining to Example 9. As shown inFIGS. 12A through 12C, the electronic device900in Example 9 is a DC-DC converter, for example, equipped with the coil component100in Example 1 and a circuit board90on which the coil component100is mounted.

The external terminal49aof the coil component100is connected to a signal pad92aon the circuit board90via the solder80, while the external terminal49bis connected to a signal pad92bon the circuit board90via the solder80. The bottom part72of the dummy terminal60is connected to a ground pad92con the circuit board90via the solder80. When the coil component100is mounted on the circuit board90, the solder80provided to the end parts46a,46bmelts before the solder80provided to the bottom part72of the dummy terminal60does. This is because almost all of the bottom part72of the dummy terminal60is contacting the core10which is a magnetic material, and therefore the temperature of the solder80provided to the end parts46a,46brises faster. A higher voltage is applied to the pad92athan to the pad92b. For example, a voltage of 50 V is applied to the pad92a, while a voltage of 5 V is applied to the pad92b.

As described above, according to Example 9 a higher voltage is applied to the pad92ato which the external terminal49aof the lead part48athat has been led out from the spiral part42on the top face26side of the core10is connected, than to the pad92bto which the external terminal49bof the lead part48bthat has been led out from the spiral part42on the bottom face28side of the core10is connected. The electric field strength generating on the lead part48aside to which the pad92aunder a higher voltage is connected, is greater than the electric field strength generating on the lead part48bside to which the pad92bunder a lower voltage is connected. For this reason, the fact that the lead part48ais led out from the spiral part42on the top face26side of the core10means the location where greater electric field strength generates is positioned near the top part70of the dummy terminal60, and this in turn allows for effective shielding of the electric field.

It should be noted that, while the electronic device900illustrated in Example 9 was equipped with the coil component100in Example 1, it may be equipped with the coil component in any of Examples 2 through 8.

The foregoing described examples of the present invention in detail; however, the present invention is not limited to these specific examples, and various modifications and changes can be added so long as they do not deviate from the key points of the present invention as described in “What Is Claimed Is.”

In the present disclosure where conditions and/or structures are not specified, a skilled artisan in the art can readily provide such conditions and/or structures, in view of the present disclosure, as a matter of routine experimentation. Also, in the present disclosure including the examples described above, any ranges applied in some embodiments may include or exclude the lower and/or upper endpoints, and any values of variables indicated may refer to precise values or approximate values and include equivalents, and may refer to average, median, representative, majority, etc. in some embodiments. Further, in this disclosure, “a” may refer to a species or a genus including multiple species, and “the invention” or “the present invention” may refer to at least one of the embodiments or aspects explicitly, necessarily, or inherently disclosed herein. The terms “constituted by” and “having” refer independently to “typically or broadly comprising”, “comprising”, “consisting essentially of”, or “consisting of” in some embodiments. In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments.

The present application claims priority to Japanese Patent Application No. 2017-088776, filed Apr. 27, 2017, the disclosure of which is incorporated herein by reference in its entirety including any and all particular combinations of the features disclosed therein.