JP2018006480A - Planar coil element and wireless power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar coil element capable of realizing large power supply by reducing conductor loss.SOLUTION: A planar coil element 1 includes an isolation layer 2, a first conductive pattern 3 disposed on one side of the isolation layer, and a second conductive pattern disposed on the other side of the isolation layer. The first and second conductive patterns are formed spirally with the same winding direction, in the plan view, and a pair of end crosslinking circuits 6 electrically connect the inner ends and outer ends of the first and second conductive patterns, respectively.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a planar coil element and a wireless power feeder.

  With the spread of RFID (Radio Frequency IDentification) systems that use Near Field Communication (NFC) technology and non-contact IC cards, wireless (non-contact) power supply devices that use electromagnetic induction have become widespread. I am doing. In this wireless power feeding device, a power feeding coil and a power receiving coil are arranged so as to face each other, and a current is generated in the power receiving coil by a magnetic flux generated by passing a current through the power feeding coil.

  In addition, with the recent miniaturization and thinning of portable devices, there is an increasing demand for miniaturization and thinning of the coil elements provided in the wireless power supply apparatus. Based on such a requirement, for example, a planar coil element has been devised in which a planar coil having a spiral shape in a plan view is disposed on the surface of a magnetic material sheet (see JP 2006-42519 A).

JP 2006-42519 A

  However, the planar coil element described in the above publication has a large conductor loss because the conductor thickness is small. Therefore, this planar coil element tends to generate heat due to increased conductor loss. As a result, this planar coil element has the disadvantage that it is difficult to supply a large amount of power and the charging efficiency cannot be sufficiently increased.

  The present invention has been made based on the above-described circumstances, and an object of the present invention is to provide a planar coil element and a wireless power feeding apparatus that can realize a large power supply by reducing a conductor loss.

  A planar coil element according to an aspect of the present invention, which has been made to solve the above problems, includes an insulating layer, a first conductive pattern disposed on one surface side of the insulating layer, and the other of the insulating layer. A planar coil element having a second conductive pattern disposed on a surface side, wherein the first conductive pattern and the second conductive pattern are formed in a spiral shape having the same winding direction in a plan view. A pair of end bridging circuits that electrically connect the inner end portions and the outer end portions of the one conductive pattern and the second conductive pattern are provided.

  A wireless power feeder according to another embodiment of the present invention, which has been made to solve the above problems, includes a power feeder and a power receiver, and the power feeder or the power receiver has the planar coil element.

  The planar coil element and the wireless power feeder of the present invention can realize a large power supply by reducing the conductor loss.

It is a typical top view showing the 1st conductive pattern of the plane coil element concerning one embodiment of the present invention. It is a schematic plan view which shows the 2nd conductive pattern in the state which reversed the planar coil element of FIG. 1 in the left-right direction. FIG. 2 is a partial cross-sectional view taken along line AA of the planar coil element of FIG. 1. It is a typical top view which shows the 1st conductive pattern of the planar coil element which concerns on different embodiment from the planar coil element of FIG. It is a typical top view which shows the 2nd conductive pattern in the state which reversed the planar coil element of FIG. 4 to the left-right direction. FIG. 5 is a schematic exploded perspective view showing a connection structure by an exchange bridge circuit of the planar coil element of FIG. 4. FIG. 5 is a schematic plan view showing a first conductive pattern of a planar coil element according to an embodiment different from the planar coil element of FIGS. 1 and 4. It is a typical top view which shows the 2nd conductive pattern in the state which reversed the planar coil element of FIG. 7 in the left-right direction.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.

  The planar coil element according to one aspect of the present invention includes an insulating layer, a first conductive pattern disposed on one surface side of the insulating layer, and a second surface disposed on the other surface side of the insulating layer. A planar coil element comprising a conductive pattern, wherein the first conductive pattern and the second conductive pattern are formed in a spiral shape having the same winding direction in plan view, and the first conductive pattern and the second conductive pattern It has a pair of edge bridge circuits that electrically connect the inner edges and the outer edges.

  In the planar coil element, the first conductive pattern and the second conductive pattern are formed in a spiral shape having the same winding direction in plan view, and the inner end portions and the outer end portions are electrically connected by a pair of end bridging circuits. Therefore, one coil circuit can be formed by the first conductive pattern and the second conductive pattern. Further, the planar coil element has the first conductive pattern and the second conductive pattern formed in a spiral shape having the same winding direction in plan view, so that the cross-sectional areas of the first conductive pattern and the second conductive pattern can be reduced. The apparent conductor cross-sectional area of the circuit can be increased by the addition, and as a result, the resistance of the entire circuit can be reduced. Therefore, the planar coil element can suppress heat generation by reducing the conductor loss, thereby realizing a large power supply.

  The first conductive pattern and the second conductive pattern are divided at one or a plurality of places, and a plurality of exchange bridging circuits for exchanging the divided pieces of the first conductive pattern and the second conductive pattern in series are provided. Good. In this way, by having a plurality of exchange bridging circuits for exchanging the divided pieces of the first conductive pattern and the second conductive pattern in series, the capacitor formed of the first conductive pattern and the second conductive pattern Capacitance can be reduced, and thereby deterioration of frequency characteristics can be suppressed.

  The average number of the exchange bridging circuits with respect to the number of turns of the first conductive pattern and the second conductive pattern is preferably 0.1 piece / turn or more and 10 pieces / turn or less. As described above, when the average number of the exchange bridging circuits with respect to the number of turns of the first conductive pattern and the second conductive pattern is within the above range, it is possible to easily and reliably suppress the deterioration of the frequency characteristics.

  The first conductive pattern and the second conductive pattern are each wound in a polygonal shape in plan view, and the plurality of exchange bridging circuits may connect the corners of the first conductive pattern and the second conductive pattern. . As described above, the plurality of exchange bridging circuits connect the corners of the first conductive pattern and the second conductive pattern to increase the density of the first conductive pattern and the second conductive pattern, and The fractional pieces of the second conductive pattern can be interchanged in series.

  It is preferable to have one or a plurality of intermediate bridge circuits that electrically connect intermediate portions of the first conductive pattern and the second conductive pattern. Thus, by having one or a plurality of intermediate bridging circuits that electrically connect the intermediate portions of the first conductive pattern and the second conductive pattern, variations in the thickness of the first conductive pattern and the second conductive pattern. It is possible to suppress an increase in the combined resistance value due to the above.

  The average number of the intermediate bridging circuits with respect to the number of turns of the first conductive pattern and the second conductive pattern is preferably 1 / turn to 10 / turn. As described above, when the average number of the intermediate bridge circuits with respect to the number of turns of the first conductive pattern and the second conductive pattern is within the above range, the thickness of the first conductive pattern and the second conductive pattern varies. The increase in the combined resistance value due to the can be easily and reliably suppressed.

  The first conductive pattern and the second conductive pattern may overlap in 30% or more of the total length in plan view. As described above, since the first conductive pattern and the second conductive pattern overlap in plan view, it is possible to improve the efficiency of transferring electricity while promoting downsizing.

  A wireless power feeder according to another embodiment of the present invention, which has been made to solve the above problems, includes a power feeder and a power receiver, and the power feeder or the power receiver has the planar coil element.

  Since the wireless power feeding apparatus includes the planar coil element, it is possible to reduce heat loss by reducing the conductor loss as described above, thereby realizing a large power supply.

  In the present invention, the “spiral shape” is not limited to a strict spiral shape, but includes a shape divided at one or a plurality of points in the longitudinal direction. Further, “the conductive pattern is wound in a polygonal shape in plan view” means that, for example, the bent portion of the conductive pattern constituting the corner of the polygonal shape is an arc shape in addition to the case where the conductive pattern is wound in a complete polygonal shape. And those in which the linear portion of the conductive pattern constituting one side of the polygon is partially bent.

[Details of the embodiment of the present invention]
Hereinafter, a planar coil element and a wireless power feeding apparatus according to an embodiment of the present invention will be described with reference to the drawings as appropriate.

[First embodiment]
<Planar coil element>
1 and 2, the planar coil element 1 includes an insulating layer 2, a first conductive pattern 3 provided on one surface side of the insulating layer 2, and a first conductive pattern 3 provided on the other surface side of the insulating layer 2. 2 conductive patterns 4. Moreover, the planar coil element 1 has a pair of coverlays 5 that cover the outer surface side of the first conductive pattern 3 and the outer surface side of the second conductive pattern 4 as shown in FIG. 3. In the planar coil element 1, the first conductive pattern 3 is directly stacked on one surface of the insulating layer 2, and the second conductive pattern 4 is directly stacked on the other surface of the insulating layer 2. The “outer surface side” means the opposite side of the surface that is laminated on the insulating layer 2.

  In the planar coil element 1, the first conductive pattern 3 and the second conductive pattern 4 are formed in a spiral shape having the same winding direction in plan view. The widths of the first conductive pattern 3 and the second conductive pattern 4 are substantially the same. Furthermore, the first conductive pattern 3 and the second conductive pattern 4 have substantially the same plan view shape viewed from the same direction. The planar coil element 1 has a pair of end bridging circuits 6 that electrically connect the inner ends and the outer ends of the first conductive pattern 3 and the second conductive pattern 4. The planar coil element 1 includes a first connection terminal 7 connected to the inner side in the winding direction than the inner end connected to the end bridging circuit 6 of the first conductive pattern 3, and the end of the first conductive pattern 3. It has the 2nd connecting terminal 8 connected to the outer side of a winding direction rather than the outer side edge part connected to the partial bridge circuit 6. FIG.

  In the planar coil element 1, the first conductive pattern 3 and the second conductive pattern 4 are formed in a spiral shape with the same winding direction in plan view, and the inner end portions and the outer end portions are a pair of end bridges. Since they are electrically connected by the circuit 6, one coil circuit can be formed by the first conductive pattern 3 and the second conductive pattern 4. Further, the planar coil element 1 is formed such that the first conductive pattern 3 and the second conductive pattern 4 are formed in a spiral shape having the same winding direction in plan view. By adding the four cross-sectional areas, the apparent conductor cross-sectional area of the circuit can be increased, and as a result, the resistance of the entire circuit can be reduced. Therefore, the planar coil element 1 can reduce the conductor loss and suppress the heat generation, thereby realizing a large power supply.

  The lower limit of the maximum power that can be transmitted by the planar coil element 1 is preferably 5 W, and more preferably 10 W. If the maximum power is less than the lower limit, there is a possibility that large power supply cannot be sufficiently realized. In addition, although it does not specifically limit as an upper limit of the said maximum electric power, For example, it can be set to 100W.

(Conductive pattern)
As shown in FIGS. 1 and 2, the first conductive pattern 3 and the second conductive pattern 4 are respectively wound in a polygonal shape in plan view, whereby the outer shape of the first conductive pattern 3 and the second conductive pattern 4 is It is formed in a polygonal shape. In particular, the first conductive pattern 3 and the second conductive pattern 4 are respectively wound in a square shape in plan view, whereby the outer shape of the first conductive pattern 3 and the second conductive pattern 4 is a square shape. As described above, the first conductive pattern 3 has an inner end connected to the first connection terminal 7 and an outer end connected to the second connection terminal 8. On the other hand, both ends of the second conductive pattern 4 are electrically connected to the first conductive pattern 3 by the end bridge circuit 6, but are not connected to an electronic component such as a connection terminal. The first conductive pattern 3 and the second conductive pattern 4 are formed in a polygonal shape having the same winding direction in plan view, and the inner end portions and the outer end portions are electrically connected by a pair of end bridging circuits 6. As a result, one coil circuit is formed.

  The first conductive pattern 3 and the second conductive pattern 4 overlap in plan view. The first conductive pattern 3 and the second conductive pattern 4 preferably overlap in plan view at 30% or more of the total length, more preferably overlap at 90% or more, and further overlap at 100%. preferable. If the overlapping degree in the planar view of the 1st conductive pattern 3 and the 2nd conductive pattern 4 is less than the said minimum, there exists a possibility that it may become difficult to raise the transfer efficiency of electricity, promoting the miniaturization of the said planar coil element 1. is there.

  The inner ends and the outer ends of the first conductive pattern 3 and the second conductive pattern 4 are electrically connected by a through hole. That is, the pair of end bridge circuits 6 are each formed by a through hole. Specifically, the through hole penetrates the first conductive pattern 3, the insulating layer 2 and the second conductive pattern 4, and electrically connects the first conductive pattern 3 and the second conductive pattern 4. The through hole is formed, for example, by forming a through hole penetrating the first conductive pattern 3, the insulating layer 2, and the second conductive pattern 4, and plating the through hole with copper, nickel, silver or the like. The through hole can also be formed by injecting a silver paste, a copper paste or the like into the through hole and curing it by heating. In the planar coil element 1, one end bridging circuit 6 may be formed by one through hole, but one end bridging circuit 6 is preferably formed by a plurality of through holes. The planar coil element 1 can further reduce the conductor loss by forming one end bridging circuit 6 with a plurality of through holes in this way. When one end bridge circuit 6 is formed by a plurality of through holes, the lower limit of the number of through holes forming one end bridge circuit 6 is preferably two, and more preferably three. On the other hand, the upper limit of the number of through holes is preferably 10 and more preferably 8.

  The main component of the first conductive pattern 3 and the second conductive pattern 4 is not particularly limited as long as it has conductivity, and examples thereof include copper, silver, platinum, and nickel. Moreover, the 1st conductive pattern 3 and the 2nd conductive pattern 4 may have plated the surface of gold | metal | money, silver, tin, nickel, etc. The first conductive pattern 3 and the second conductive pattern 4 may be formed by, for example, a subtractive method in which conductive layers are stacked on both surfaces of the insulating layer 2 and masked with a resist pattern or the like on the conductive layer and etched. You may form by a semi-additive method. Moreover, you may form the 1st conductive pattern 3 and the 2nd conductive pattern 4 by printing with the paste, ink, etc. which mix | blended metals, such as copper, silver, and nickel. The “main component” means a component having the largest content, for example, a component having a content of 50% by mass or more.

  The first conductive pattern 3 and the second conductive pattern 4 are formed to have substantially the same thickness. The lower limit of the average thickness of the first conductive pattern 3 and the second conductive pattern 4 is preferably 0.1 μm and more preferably 1 μm. On the other hand, the upper limit of the average thickness is preferably 230 μm, and more preferably 210 μm. If the average thickness is less than the lower limit, the conductor resistance may increase and the conductor loss may increase. If the average thickness is less than the lower limit, the strength is insufficient and the first conductive pattern 3 and the second conductive pattern may be easily broken. On the other hand, if the average thickness exceeds the upper limit, the planar coil element 1 may be contrary to the demand for thickness reduction.

  As a minimum of the number of turns of the 1st conductive pattern 3 and the 2nd conductive pattern 4, 1 roll is preferred and 2 rolls are more preferred. On the other hand, the upper limit of the number of turns is preferably 100 turns, and more preferably 80 turns. If the number of turns is less than the lower limit, there is a possibility that sufficient power transmission cannot be performed. On the other hand, if the number of turns exceeds the upper limit, the planar coil element 1 may be contrary to the demand for downsizing.

  As a minimum of the length (full length) of the 1st conductive pattern 3 and the 2nd conductive pattern 4, 50 mm is preferred and 100 mm is more preferred. On the other hand, the upper limit of the length is preferably 10,000 mm, and more preferably 8000 mm. If the length is less than the lower limit, the number of turns of the coil becomes insufficient, and there is a possibility that sufficient power transmission cannot be performed. On the other hand, if the length exceeds the upper limit, the planar coil element 1 may be contrary to the demand for downsizing. The “length of the conductive pattern” refers to the length of the central axis extending from the inner edge to the outer edge of the conductive pattern.

  As a minimum of the length of one side (straight line part) located in the outermost side of the 1st conductive pattern 3 and the 2nd conductive pattern 4, 1 mm is preferred and 5 mm is more preferred. On the other hand, the upper limit of the length of one side is preferably 100 mm, and more preferably 80 mm. If the length of one side is less than the lower limit, the number of turns of the coil becomes insufficient, and there is a possibility that sufficient power transmission cannot be performed. Conversely, if the length of the one side exceeds the upper limit, the planar coil element 1 may be contrary to the demand for downsizing.

  As a lower limit of the average distance (the average distance between adjacent circuits of the first conductive pattern 3 and the average distance between adjacent circuits of the second conductive pattern 4) in plan view of the first conductive pattern 3 and the second conductive pattern 4 Is preferably 20 μm, more preferably 50 μm. On the other hand, the upper limit of the average interval is preferably 4.5 mm, and more preferably 1 mm. If the average distance is less than the lower limit, it may be difficult to form the first conductive pattern 3 and the second conductive pattern 4 due to an etching factor or the like. Conversely, if the average interval exceeds the upper limit, the density of the first conductive pattern 3 and the second conductive pattern 4 may not be sufficiently high.

(Insulating layer)
The insulating layer 2 has electrical insulation and prevents a short circuit due to electrical contact between the first conductive pattern 3 and the second conductive pattern 4. The insulating layer 2 may not have flexibility, but is preferably flexible in that the planar coil element 1 can be configured as a flexible planar coil element. When the insulating layer 2 is flexible, examples of the main component of the insulating layer 2 include synthetic resins such as polyimide, polyethylene terephthalate, polyethylene naphthalate, liquid crystal polymer, and fluororesin. On the other hand, when the insulating layer 2 is not flexible, the main component of the insulating layer 2 is a rigid material such as glass.

  As a minimum of average thickness of insulating layer 2, 5 micrometers is preferred and 10 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the insulating layer 2 is preferably 100 μm, and more preferably 80 μm. If the average thickness of the insulating layer 2 is less than the lower limit, the insulating property may be insufficient. On the other hand, if the average thickness of the insulating layer 2 exceeds the above upper limit, there is a risk that it will violate the demand for thinning the planar coil element 1.

(Coverlay)
The pair of coverlays 5 protect the first conductive pattern 3 and the second conductive pattern 4. The pair of coverlays 5 have insulating properties. Each of the pair of coverlays 5 includes a cover film 5a and a cover film adhesive layer 5b.

  The cover film 5a has flexibility and insulation. Examples of the main component of the cover film 5a include polyimide, epoxy resin, phenol resin, acrylic resin, polyester, polyimide, polyethylene terephthalate, polyethylene naphthalate, fluororesin, and liquid crystal polymer. Among these, polyimide is preferable because of its high heat resistance. Further, the cover film 5a may contain a resin other than the main component, a weathering agent, an antistatic agent, and the like.

  As a minimum of average thickness of cover film 5a, 3 micrometers is preferred and 10 micrometers is more preferred. On the other hand, the upper limit of the average thickness is preferably 500 μm, and more preferably 150 μm. If the average thickness is less than the lower limit, the first conductive pattern 3 and the second conductive pattern 4 may not be sufficiently protected, and the insulating property of the cover film 5a may be insufficient. On the contrary, when the average thickness exceeds the upper limit, the protective effect of the first conductive pattern 3 and the second conductive pattern 4 may not be improved so much and the flexibility of the cover film 5a may be insufficient. There is.

  Although it does not specifically limit as an adhesive agent which comprises the cover film contact bonding layer 5b, The thing excellent in a softness | flexibility and heat resistance is preferable. Examples of the adhesive include various resin adhesives such as epoxy resin, polyimide, polyester, phenol resin, polyurethane, acrylic resin, melamine resin, and polyamideimide.

  The lower limit of the average thickness of the cover film adhesive layer 5b is preferably 5 μm and more preferably 10 μm. On the other hand, the upper limit of the average thickness is preferably 300 μm, and more preferably 280 μm. If the average thickness is less than the lower limit, the bonding strength of the pair of coverlays 5 to the first conductive pattern 3 and the second conductive pattern 4 may be insufficient. On the other hand, if the average thickness exceeds the upper limit, the planar coil element 1 may be contrary to the demand for thickness reduction.

[Second Embodiment]
<Planar coil element>
The planar coil element 11 shown in FIGS. 4 and 5 includes an insulating layer 2, a first conductive pattern 13 provided on one surface side of the insulating layer 2, and a first conductive pattern 13 provided on the other surface side of the insulating layer 2. 2 conductive patterns 14. In addition, the planar coil element 11 has a cover lay covering the outer surface side of the first conductive pattern 13 and a cover lay covering the outer surface side of the second conductive pattern 14 as in the planar coil element 1 of FIG. (Ray not shown) In the planar coil element 11, the first conductive pattern 13 is directly stacked on one surface of the insulating layer 2, and the second conductive pattern 14 is directly stacked on the other surface of the insulating layer 2. The planar coil element 11 includes a first connection terminal 7 connected to the inner end of the first conductive pattern 13 in the winding direction and a second connection connected to the outer end of the first conductive pattern 13 in the winding direction. And a connection terminal 8.

  The first conductive pattern 13 and the second conductive pattern 14 are formed in a spiral shape having the same winding direction in plan view. The widths of the first conductive pattern 13 and the second conductive pattern 14 are substantially the same. Further, the first conductive pattern 13 and the second conductive pattern 14 have substantially the same plan view shape viewed from the same direction. The planar coil 11 has a pair of end bridging circuits 6 that electrically connect the inner ends and the outer ends of the first conductive pattern 13 and the second conductive pattern 14. In the planar coil element 11, the first conductive pattern 13 and the second conductive pattern 14 are divided at a plurality of locations. The planar coil element 11 has a plurality of exchange bridging circuits 15 for exchanging the divided pieces of the first conductive pattern 13 and the second conductive pattern 14 in series. The planar coil element 11 has the same configuration as the planar coil element 1 of FIG. 1 except for the first conductive pattern 13, the second conductive pattern 14, and the plurality of exchange bridge circuits 15. Therefore, only the first conductive pattern 13, the second conductive pattern 14, and the plurality of exchange bridge circuits 15 will be described below.

  The planar coil element 11 includes a plurality of exchange bridging circuits 15 that replace the divided fragment 13a of the first conductive pattern 13 and the divided fragment 14a of the second conductive pattern 14 in series, thereby providing the first conductive pattern. The capacitance of the capacitor formed by the pattern 13 and the second conductive pattern 14 can be reduced, thereby suppressing the deterioration of the frequency characteristics.

(Conductive pattern)
As shown in FIGS. 4 and 5, the first conductive pattern 13 and the second conductive pattern 14 are respectively wound in a polygonal shape (square shape) in plan view, whereby the first conductive pattern 13 and the second conductive pattern are wound. The outer shape of 14 is formed in a polygonal shape (square shape). The first conductive pattern 13 and the second conductive pattern 14 form one coil circuit as in the planar coil element 1 of FIG.

  The first conductive pattern 13 and the second conductive pattern 14 are divided at a plurality of locations as described above, and in detail, are divided at substantially the same location in plan view. As a minimum of division frequency of the 1st conductive pattern 13 and the 2nd conductive pattern 14, 0.1 place / wind is preferred and 0.2 place / wind is more preferred. On the other hand, the upper limit of the dividing frequency is preferably 10 places / wind, and more preferably 5 places / wind. If the division frequency is less than the lower limit, the deterioration of the frequency characteristics due to the first conductive pattern 13 and the second conductive pattern 14 may not be sufficiently suppressed. On the other hand, if the division frequency exceeds the upper limit, it may be difficult to adjust the inductance.

  The plurality of fractional pieces 13a of the first conductive pattern 13 and the plurality of fractional pieces 14a of the second conductive pattern 14 are disposed at positions overlapping in plan view. An inner end portion of one segment 13a of the first conductive pattern 13 is a segment of the second conductive pattern 14 that overlaps the other segment 13a adjacent to the inner side of the segment 13a and in the direction in which the circuit is continuous in a plan view. The outer end of 14a is electrically connected by the exchange bridge circuit 15. Further, the outer end portion of one segment 13a of the first conductive pattern 13 has the second conductive pattern 14 that overlaps the other segment 13a adjacent to the outside of the segment 13a and in the direction in which the circuit is continuous in a plan view. The inner end of the segment 14a is electrically connected by the exchange bridge circuit 15. As a result, the planar coil element 11 has the inner end of one segment 13a of the first conductive pattern 13 and the outer end of one segment 14a of the second conductive pattern 14 connected in series, and the first The outer end of this segment 13a of the conductive pattern 13 and the inner end of the other segment 14a of the second conductive pattern 14 are connected in series. It should be noted that the inner end portion of the fraction piece 13a arranged on the innermost side among the plurality of fraction pieces 13a of the first conductive pattern 13 and the innermost side among the plurality of fraction pieces 14a of the second conductive pattern 14 are arranged. As described above, the inner end of the segment 14a is electrically connected by the end bridge circuit 6 as described above, and therefore, the replacement bridge circuit 15 is not connected to these inner ends. Similarly, the outer end portion of the segment 13a disposed on the outermost side among the plurality of segment pieces 13a of the first conductive pattern 13 and the outermost side of the segment segments 14a of the second conductive pattern 14 are arranged on the outermost side. Since the outer end portion of the provided fragment 14a is electrically connected by the end bridge circuit 6 as described above, the exchange bridge circuit 15 is not connected to these outer end portions.

With reference to FIG. 6, the structure which replaces the fraction pieces of the 1st conductive pattern 13 and the 2nd conductive pattern 14 in series is explained in full detail. In FIG. 6, the insulating layer 2 is omitted so that the connection structure between the fragment pieces can be easily understood. As shown in FIG. 6, the first conductive pattern 13 and the second conductive pattern 14 are divided at the corners of the polygonal shape, and the exchange bridge circuit 15a and the exchange bridge circuit 15b are connected to the first conductive pattern 13 and the second conductor pattern 13. The corner portions of the conductive pattern 14 are connected to each other. Specifically, a curved portion 13c curved outward in a polygonal shape in plan view is formed at the outer end portion of _one segment 13a1 of the first conductive pattern 13, and the outside of the curved portion 13c and the circuit are continuous. the inner end of the other partial fragments 13a ₂ adjacent in the direction the curved portion 13d is formed with an inwardly curved polygonal in plan view. On the other hand, minute fragments 14a ₁ of the second conductive pattern 14 overlaps with the one minute fragments 13a ₁ is arranged to the outer end portion overlaps the curved portion 13d in plan view, and the outside of the minute fragments 14a ₁ The other fragment 14a _{2 that} is adjacent to the outside of the end and in the direction in which the circuits are continuous is disposed so that the inner end overlaps the curved portion 13c in plan view. In this state, electrically by one minute fragments 13a ₁ of the curved portion 13c and the other portions overlapping in a plan view of the partial fragments 14a ₂ of the second conductive pattern 14 is one exchange crosslinking circuit 15a of the first conductive pattern 13 connected, and electrically by other partial fragments 13a ₂ of the bending portion 13d and the one minute fragments 14a ₁ of the portion other switching bridge circuit 15b overlapping in a plan view of the second conductive pattern 14 of the first conductive pattern 13 It is connected.

  In the planar coil element 11, the plurality of exchange bridging circuits 15 connect the corners of the first conductive pattern 13 and the second conductive pattern 14 as described above, whereby the first conductive pattern 13 and the second conductive pattern are connected. 14, the fraction 13 a of the first conductive pattern 13 and the fraction 14 a of the second conductive pattern 14 can be switched in series.

  The plurality of exchange bridging circuits 15 are formed by through holes similar to the pair of end bridging circuits 6. In the planar coil element 11, one exchange bridge circuit 15 may be formed by one through hole, but one exchange bridge circuit 15 is preferably formed by a plurality of through holes. In this way, the planar coil element 11 can more accurately suppress the deterioration of the frequency characteristics by forming one exchange bridge circuit 15 with a plurality of through holes. When one exchange bridge circuit 15 is formed by a plurality of through holes, the lower limit of the number of through holes forming one exchange bridge circuit 15 is preferably two and more preferably three. On the other hand, the upper limit of the number of through holes is preferably 10 and more preferably 8.

  The lower limit of the average number of exchange bridging circuits 15 with respect to the number of turns of the first conductive pattern 13 and the second conductive pattern 14 is preferably 0.1 piece / turn, and more preferably 0.2 piece / turn. On the other hand, the upper limit of the average existence number is preferably 10 pieces / turn, and more preferably 5 pieces / turn. If the average existence number is less than the lower limit, the deterioration of the frequency characteristics may not be sufficiently suppressed. On the contrary, if the average number exceeds the upper limit, it may be difficult to adjust the inductance.

  The lower limit of the number of exchange bridging circuits 15 with respect to the length of the first conductive pattern 13 and the second conductive pattern 14 is preferably 0.005 / cm, and more preferably 0.01 / cm. On the other hand, the upper limit of the number of existence is preferably 5 / cm, and more preferably 1 / cm. If the number of the existing elements is less than the lower limit, the deterioration of the frequency characteristics may not be sufficiently suppressed. On the other hand, if the number of existence exceeds the upper limit, it may be difficult to adjust the inductance.

  The lower limit of the number of exchange bridging circuits 15 with respect to the number of sides (the number of straight portions) forming the first conductive pattern 13 and the second conductive pattern 14 in a polygonal shape is preferably 0.025 / side. 05 / side is more preferable. On the other hand, the upper limit of the existence number is preferably 2.5 / side, more preferably 1.25 / side. If the number of the existing elements is less than the lower limit, the deterioration of the frequency characteristics may not be sufficiently suppressed. On the other hand, if the number of existence exceeds the upper limit, it may be difficult to adjust the inductance.

  Note that the overlapping ratio, the main component, the average thickness, the number of turns, the length (full length), the length of one side, and the average interval in plan view of the first conductive pattern 13 and the second conductive pattern 14 are shown in FIG. The planar coil element 1 can be the same.

[Third embodiment]
<Planar coil element>
7 and 8, the planar coil element 21 includes an insulating layer 2, a first conductive pattern 23 provided on one surface side of the insulating layer 2, and a first electrode provided on the other surface side of the insulating layer 2. 2 conductive patterns 24. Further, the planar coil element 21 has a cover lay that covers the outer surface side of the first conductive pattern 23 and a cover lay that covers the outer surface side of the second conductive pattern 24, as in the planar coil element 1 of FIG. Is omitted). In the planar coil element 21, the first conductive pattern 23 is directly stacked on one surface of the insulating layer 2, and the second conductive pattern 24 is directly stacked on the other surface of the insulating layer 2. The planar coil element 21 has a first connection terminal 7 connected to the inner end of the first conductive pattern 23 and a second connection terminal 8 connected to the outer end of the first conductive pattern 23.

  The first conductive pattern 23 and the second conductive pattern 24 are formed in a spiral shape having the same winding direction in plan view. The widths of the first conductive pattern 23 and the second conductive pattern 24 are substantially the same. Further, the first conductive pattern 23 and the second conductive pattern 24 have substantially the same shape in plan view when viewed from the same direction. The planar coil 11 has a pair of end bridging circuits 6 that electrically connect the inner ends and the outer ends of the first conductive pattern 23 and the second conductive pattern 24. In the planar coil element 11, the first conductive pattern 23 and the second conductive pattern 24 are divided at a plurality of locations, and the divided pieces of the first conductive pattern 23 and the second conductive pattern 24 are connected in series. A plurality of exchange bridge circuits 15 to be exchanged are provided. Further, the planar coil element 21 has a plurality of intermediate bridge circuits 25 that electrically connect intermediate portions of the first conductive pattern 23 and the second conductive pattern 24. The planar coil element 21 includes a plurality of intermediate bridging circuits 25 that electrically connect intermediate portions of the first conductive pattern 23 and the second conductive pattern 24, so that the first conductive pattern 23 and the second conductive pattern 24. An increase in the combined resistance value due to variations in the thickness of the film can be suppressed. The planar coil element 21 has the same configuration as the planar coil element 11 shown in FIGS. 4 and 5 except that the planar coil element 21 includes a plurality of intermediate bridge circuits 25. Therefore, only the plurality of intermediate bridge circuits 25 will be described below.

(Intermediate bridge circuit)
The plurality of intermediate bridging circuits 25 are arranged in a planar view radial shape with the polygonal center portion as the center. The plurality of intermediate bridge circuits 25 are arranged at a narrower pitch toward the inside of the first conductive pattern 23 and the second conductive pattern 24.

  The plurality of intermediate bridge circuits 25 are formed by through holes similar to those of the pair of end bridge circuits 6. In the planar coil element 21, one intermediate bridge circuit 25 may be formed by one through hole, but one intermediate bridge circuit 25 may be formed by a plurality of through holes. When one intermediate bridge circuit 25 is formed by a plurality of through holes, the lower limit of the number of through holes forming one intermediate bridge circuit 25 is preferably two and more preferably three. On the other hand, the upper limit of the number of through holes is preferably 10 and more preferably 8.

  The lower limit of the average number of intermediate bridge circuits 25 with respect to the number of turns of the first conductive pattern 23 and the second conductive pattern 24 is preferably 1 piece / turn, more preferably 2 pieces / turn, and further preferably 3 pieces / turn. . On the other hand, the upper limit of the average existence number is preferably 10 pieces / turn, more preferably 9 pieces / turn, and further preferably 8 pieces / turn. If the average existence number is less than the lower limit, an increase in the combined resistance value due to variations in the thickness of the first conductive pattern 23 and the second conductive pattern 24 may not be sufficiently suppressed. On the contrary, when the average number exceeds the upper limit, the effect of suppressing the increase in the combined resistance value may not be improved so much.

  The lower limit of the number of intermediate bridge circuits 25 with respect to the lengths of the first conductive pattern 23 and the second conductive pattern 24 is preferably 0.01 / mm, and more preferably 0.02 / mm. On the other hand, the upper limit of the number of existence is preferably 1 piece / mm, more preferably 0.8 piece / mm. If the number of the existing elements is less than the lower limit, an increase in the combined resistance value due to the thickness variation of the first conductive pattern 23 and the second conductive pattern 24 may not be sufficiently suppressed. On the other hand, if the number of the existing elements exceeds the upper limit, the effect of suppressing the increase in the combined resistance value may not be improved so much.

  The lower limit of the number of intermediate bridging circuits 25 with respect to the number of sides (the number of straight portions) forming the first conductive pattern 23 and the second conductive pattern 24 in a polygonal shape is preferably 0.2 / side. / Side is more preferable, and 1.5 / side is more preferable. On the other hand, the upper limit of the number of existence is preferably 2.5 pieces / side, more preferably 2.2 pieces / side, and further preferably 2 pieces / side. If the number of the existing elements is less than the lower limit, an increase in the combined resistance value due to the thickness variation of the first conductive pattern 23 and the second conductive pattern 24 may not be sufficiently suppressed. On the other hand, if the number of the existing elements exceeds the upper limit, the effect of suppressing the increase in the combined resistance value may not be improved so much.

[Fourth embodiment]
<Wireless power supply device>
The wireless power feeder includes a power feeder and a power receiver, and the power feeder or the power receiver has the planar coil element described above. In the wireless power feeding apparatus, since the planar coil element can reduce the conductor loss and suppress the heat generation, a large power supply can be realized.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  The planar coil element may have a configuration in which the configurations described in the above embodiments are appropriately combined. For example, when the planar coil element has an intermediate bridge circuit, it does not necessarily have an exchange bridge circuit. Further, when the planar coil element has an intermediate bridge circuit and / or an exchange bridge circuit, it is preferable that a plurality of these intermediate bridge circuits and / or exchange bridge circuits exist, but one intermediate bridge circuit and / or 1 There may be two exchange bridging circuits.

  The planar coil element only needs to be provided with conductive patterns on both sides of at least one insulating layer. For example, even if a plurality of conductive patterns are provided on a plurality of insulating layers opposed in a plan view. Good. In addition, the planar coil element may be formed, for example, by laminating a plurality of insulating layers in which conductive patterns are disposed only on one side. Furthermore, the end bridge circuit, the intermediate bridge circuit, and the exchange bridge circuit do not need to be formed by through holes, and may be formed by blind via holes, for example.

  The first conductive pattern and the second conductive pattern preferably overlap in the plan view over the entire length, but for example, only the end bridge circuit, the intermediate bridge circuit, and the exchange bridge circuit may overlap.

  The first conductive pattern and the second conductive pattern do not necessarily have to be wound in a polygonal shape in plan view, and may be wound in a circular shape in plan view, for example. Moreover, even when the first conductive pattern and the second conductive pattern are wound in a polygonal shape in plan view, the first conductive pattern and the second conductive pattern may be wound in, for example, a triangular shape or a pentagonal shape in plan view.

  The planar coil element may include a magnetic sheet on the outer surface side of the coverlay. By disposing the magnetic material sheet on the outer surface side of the cover lay in this way, it is possible to prevent the magnetic flux from being cut off and affecting the surrounding circuits. In particular, by using a magnetic sheet having a relative permeability of 80 or more, the inductance per unit area can be increased and further miniaturization can be achieved. As this magnetic material sheet, for example, a material in which a ferromagnetic material is dispersed in a synthetic resin can be used, and a commercially available material such as a noise suppression sheet can be used.

  As described above, the planar coil element and the wireless power feeding device of the present invention can reduce the conductor loss and realize a large power supply, and thus are suitable for wireless power feeding of portable devices.

1, 11, 21 planar coil element 2 insulating layer 3,13,23 first conductive pattern 4,14,24 second conductive patterns _{13a, 13a 1, 13a 2,} 14a, 14a 1, 14a 2 minutes fragment 13c, 13d curved 5 Coverlay 5a Cover film 5b Cover film adhesive layer 6 End bridge circuit 7, 8 Connection terminal 15, 15a, 15b Exchange bridge circuit 25 Intermediate bridge circuit

Claims (8)

A planar coil element comprising an insulating layer, a first conductive pattern disposed on one surface side of the insulating layer, and a second conductive pattern disposed on the other surface side of the insulating layer,
The first conductive pattern and the second conductive pattern are formed in a spiral shape having the same winding direction in plan view,
A planar coil element having a pair of end bridging circuits that electrically connect inner end portions and outer end portions of the first conductive pattern and the second conductive pattern.   The first conductive pattern and the second conductive pattern are divided at one or a plurality of places, and a plurality of exchange bridging circuits for exchanging the divided pieces of the first conductive pattern and the second conductive pattern in series are provided. Item 2. The planar coil element according to Item 1.   3. The planar coil element according to claim 2, wherein an average number of the exchange bridging circuits with respect to the number of windings of the first conductive pattern and the second conductive pattern is 0.1 / winding or more and 10 / winding or less.   The first conductive pattern and the second conductive pattern are each wound in a polygonal shape in plan view, and the plurality of exchange bridging circuits connect corners of the first conductive pattern and the second conductive pattern. The planar coil element according to claim 2 or claim 3.   The planar coil element according to any one of claims 1 to 4, further comprising one or a plurality of intermediate bridging circuits that electrically connect intermediate portions of the first conductive pattern and the second conductive pattern.   6. The planar coil element according to claim 5, wherein an average number of the intermediate bridge circuits with respect to the number of turns of the first conductive pattern and the second conductive pattern is 1 / turn to 10 / turn.   The planar coil element according to any one of claims 1 to 6, wherein the first conductive pattern and the second conductive pattern overlap in plan view at 30% or more of the total length. A power feeder and a power receiver,
The wireless power feeder with which this feeder or power receiver has the planar coil element of any one of Claims 1-7.

Images