Power transmission unit
The power transmission unit simplifies manufacturing by integrating spirally patterned coils on a single-layer substrate and using a magnetic plate to manage magnetic flux, addressing complexity and cost issues while reducing interference.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2025-11-07
- Publication Date
- 2026-05-21
AI Technical Summary
Existing power transmission coil units require complex manufacturing processes due to the need to bond separate substrates with patterned coils, which increases production time and cost.
A power transmission unit with a single-layer dielectric substrate featuring spirally patterned first and second coils on opposing surfaces, allowing direct patterning on the substrate without the need for bonding, and utilizing a magnetic plate to manage magnetic flux.
Simplifies manufacturing by eliminating bonding steps, reduces costs, and minimizes magnetic interference with nearby devices.
Smart Images
Figure JP2025039124_21052026_PF_FP_ABST
Abstract
Description
Power transmission unit
[0001] The present disclosure generally relates to a power transmission unit. More specifically, the present disclosure relates to a power transmission unit including a coil patterned in a spiral shape.
[0002] Patent Document 1 discloses a power transmission coil unit including a first layer, a second layer, and a third layer. The first layer is made of a dielectric substrate forming a first coil having a first conductive pattern in a spiral shape. The second layer is made of a dielectric substrate forming a second coil having a second conductive pattern in the same spiral shape as the first conductive pattern. The third layer is disposed between the first layer and the second layer and has a higher dielectric tangent than those of the first and second layers.
[0003] Japanese Patent Application Laid-Open No. 2015-12137
[0004] In a power transmission coil unit (power transmission unit) such as that of Patent Document 1, simplification of manufacturing is required.
[0005] An object of the present disclosure is to provide a power transmission unit capable of simplifying manufacturing.
[0006] A power transmission unit according to an aspect of the present disclosure includes a dielectric substrate, a first coil, and a second coil. The dielectric substrate has opposing first and second surfaces and is composed of a single layer. The first coil is patterned in a spiral shape on the first surface. The second coil is patterned in a spiral shape on the second surface.
[0007] FIG. 1 is a cross-sectional view taken along line X1-X1 shown in FIGS. 3 and 4. FIG. 2 is an external perspective view of the power transmission unit according to the embodiment. FIG. 3 is a plan view of the power transmission unit described above. FIG. 4 is a bottom view of the power transmission unit described above. FIG. 5 is an explanatory diagram for explaining the position where a magnetic plate is disposed in the power transmission unit described above. FIG. 6 is a bottom view of the power transmission unit according to the first modification.
[0008] The embodiments and modifications described below are merely examples of the present disclosure. This disclosure is not limited to these embodiments and modifications, and various modifications are possible depending on the design, etc., as long as they do not depart from the technical idea of the present disclosure. The figures described in the embodiments and modifications below are schematic diagrams, and the ratios of the size and thickness of each component in the figures do not necessarily reflect the actual dimensional ratios.
[0009] (Embodiment) (1) Overview Below, an overview of the power transmission unit 100 according to this embodiment will be described with reference to Figures 1 to 4.
[0010] As shown in Figures 1 and 2, the power transmission unit 100 according to this embodiment comprises a dielectric substrate 1, a first coil 2, and a second coil 3. As shown in Figure 1, the dielectric substrate 1 has opposing first and second surfaces 11 and 12 and is made of a single layer. As shown in Figure 3, the first coil 2 is spirally patterned on the first surface 11 of the dielectric substrate 1. Similarly, as shown in Figure 4, the second coil 3 is spirally patterned on the second surface 12 of the dielectric substrate 1.
[0011] In the comparative example power transmission unit, the substrate on which the first coil is formed is bonded to the first surface of a dielectric substrate, and the substrate on which the second coil is formed is bonded to the second surface of the dielectric substrate. In other words, when manufacturing the comparative example power transmission unit, it is necessary to bond the substrate on which the first coil is formed and the substrate on which the second coil is formed to the dielectric substrate.
[0012] On the other hand, in the power transmission unit 100 of this embodiment, the first coil 2 is directly patterned on the first surface 11 of the dielectric substrate 1, and the second coil 3 is directly patterned on the second surface 12 of the dielectric substrate 1. Therefore, when manufacturing the power transmission unit 100 of this embodiment, the process of bonding the substrate on which the first coil 2 is formed and the substrate on which the second coil 3 is formed to the dielectric substrate 1 is eliminated. In other words, the power transmission unit 100 of this embodiment has the advantage of simplifying manufacturing.
[0013] (2) Detailed Configuration (2-1) Overall The detailed configuration of the power transmission unit 100 of this embodiment will be described below with reference to Figures 1 to 5.
[0014] In the following explanation, as shown in Figure 1, the direction in which the first coil 2 and the second coil 3 are aligned (facing each other) is defined as the up and down direction, the side of the first coil 2 as seen from the second coil 3 is defined as the top, and the side of the second coil 3 as seen from the first coil 2 is defined as the bottom. Unless otherwise specified, the front, back, left, and right directions indicated by arrows in Figure 2 are defined as the front, back, left, and right directions of the power transmission unit 100.
[0015] The power transmission unit 100 is used in a power supply system that provides power wirelessly using a magnetic resonance method. When the power transmission unit 100 is used as the power supply unit in the above power supply system, the power transmission unit 100 wirelessly transmits power supplied from an external power source to the other unit A1 (see Figure 5). On the other hand, when the power transmission unit 100 is used as the power receiving unit in the above power supply system, the power transmission unit 100 wirelessly transmits power supplied from the other unit A1 to the other unit A1 from the external power source.
[0016] As shown in Figures 1 and 5, the power transmission unit 100 comprises a dielectric substrate 1, a first coil 2, a second coil 3, a connection terminal 4, and a magnetic plate 5 (see Figure 5).
[0017] (2-2) Dielectric Substrate The dielectric substrate 1 is a rectangular plate member consisting of a single layer, as shown in Figure 2. The dielectric substrate 1 has a first surface 11 and a second surface 12 that face each other along the thickness direction. The first surface 11 is the upper surface of the dielectric substrate 1, and the second surface 12 is the lower surface of the dielectric substrate 1. In this disclosure, "consisting of a single layer" means that it has a single-layer structure, that is, it is composed of one layer in the thickness direction.
[0018] The dielectric substrate 1 is formed from a dielectric material. The dielectric material is, for example, glass epoxy resin.
[0019] (2-3) First coil, second coil The first coil 2 is patterned in a spiral shape on the first surface 11 of the dielectric substrate 1, as shown in Figures 2 and 3. When viewed from above, the first coil 2 of this embodiment is wound clockwise (i.e., to the right) from the outside of the spiral to the inside. In other words, the direction of the spiral (winding direction) of the first coil 2 of this embodiment is such that when viewed from above, the spiral is wound clockwise from the outside of the spiral to the inside.
[0020] Similarly, the second coil 3 is patterned in a spiral shape on the second surface 12 of the dielectric substrate 1, as shown in Figure 4. In this embodiment, the second coil 3 is wound clockwise from the outside to the inside of the spiral when viewed from below. In other words, the direction of the spiral of the second coil 3 in this embodiment is clockwise, from the outside to the inside of the spiral when viewed from below.
[0021] In other words, in this embodiment, the second coil 3 is wound counterclockwise (i.e., leftward) from the outside to the inside of the vortex when viewed from above. In short, in this embodiment, the second coil 3 is wound in a different direction from the first coil 2 when viewed along the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other. That is, in this embodiment, the direction of the vortex of the second coil 3 is different from the direction of the vortex of the first coil 2 when viewed along the opposing direction where the first surface 11 and the second surface 12 face each other. With the above configuration, the first coil 2 and the second coil 3 can each be patterned using the same pattern forming method (for example, using the same film in the etching process). Therefore, pattern formation in each of the first coil 2 and the second coil 3 becomes easier. As a result, the power transmission unit 100 of this embodiment has the advantage of being able to be manufactured more simply. In this disclosure, "when viewed through" means when the dielectric substrate 1 is viewed through, that is, when it is assumed that the dielectric substrate 1 does not exist.
[0022] The first coil 2 of this embodiment is patterned in a spiral shape so that the pattern width and pitch are uniform. Similarly, the second coil 3 of this embodiment is patterned in a spiral shape so that the pattern width and pitch are uniform. That is, each of the first coil 2 and the second coil 3 of this embodiment is patterned in an Archimedes spiral shape. In this disclosure, "pattern width" refers to the dimension in the spiral pattern along the radial direction with respect to the direction of the vortex. In other words, "pattern width" refers to the dimension in the spiral pattern along the direction perpendicular to the direction of the vortex. In this disclosure, "pitch" refers to the so-called pattern spacing, that is, the spacing between adjacent turns in a spiral pattern (for example, the spacing between the turns wound in the first rotation and the turns wound in the second rotation).
[0023] As shown in Figure 3, the first coil 2 has a first end E1 and a second end E2. The first end E1 is the inner end of the spiral-shaped first coil 2, and the second end E2 is the outer end of the spiral-shaped first coil 2. The first end E1 is an open end; that is, the first end E1 is not connected to the connection terminal 4 (see Figure 1). On the other hand, the second end E2 is connected to the connection terminal 4, as shown in Figure 1. More specifically, a lead-out portion extends from the second end E2 toward one side (the rear side) of the first surface 11, and this lead-out portion is connected to the connection terminal 4.
[0024] Similarly, the second coil 3 has a third end E3 and a fourth end E4, as shown in Figure 4. The third end E3 is the inner end of the spiral-shaped second coil 3, and the fourth end E4 is the outer end of the spiral-shaped second coil 3. The third end E3 is an open end; that is, the third end E3 is not connected to the connection terminal 4. On the other hand, the fourth end E4 is connected to the connection terminal 4, as shown in Figure 1. More specifically, a lead-out portion extends from the fourth end E4 toward one side (the rear side) of the second surface 12, and this lead-out portion is connected to the connection terminal 4.
[0025] As shown in Figure 1, the first coil 2 of this embodiment is a film formed on the first surface 11 of the dielectric substrate 1. Similarly, the second coil 3 is a film formed on the second surface 12 of the dielectric substrate 1. More specifically, each of the first coil 2 and the second coil 3 of this embodiment is copper foil.
[0026] In this embodiment, the dielectric substrate 1, the first coil 2, and the second coil 3 are formed from a double-sided copper-clad laminate. In this disclosure, a "double-sided copper-clad laminate" refers to a board in which copper foil is laminated to both sides of an insulating substrate (a so-called unclad board). In this embodiment, the first coil 2 and the second coil 3 are patterned by patterning the copper foil of the double-sided copper-clad laminate. In other words, the first coil 2 and the second coil 3 in this embodiment are the portions of the copper foil of the double-sided copper-clad laminate that were not removed by etching or the like. Furthermore, the dielectric substrate 1 in this embodiment is an insulating substrate made of a double-sided copper-clad laminate. With the above configuration, pattern formation in each of the first coil 2 and the second coil 3 becomes easier. As a result, the power transmission unit 100 of this embodiment has the advantage of being easier to manufacture. Furthermore, the power transmission unit 100 of this embodiment also has the advantage of reducing manufacturing costs.
[0027] The following describes the functions of the first coil 2 and the second coil 3, respectively.
[0028] First, let's consider the case where the power transmission unit 100 is used as a power supply unit in a power supply system. In this case, for example, an external device, such as a high-frequency oscillator, is connected to the connection terminal 4. The first coil 2 and the second coil 3 are then alternately supplied with high-frequency AC power from the high-frequency oscillator via the connection terminal 4. Subsequently, the current flowing through the first coil 2 and the second coil 3 generates a magnetic flux around them. This magnetic flux then links with the receiving unit, the other unit A1 (see Figure 5), causing an electromotive force of a magnitude corresponding to the change in linked magnetic flux to be generated in the other unit A1, and an induced current to flow. As a result, the power transmission unit 100 can supply power to the other unit A1.
[0029] Next, let's consider the case where the power transmission unit 100 is used as a receiving unit in a power supply system. In this case, for example, the load of an external power receiving device is connected to the connection terminal 4. Then, the magnetic flux generated from the receiving unit A1 (see Figure 5), which is the power supply unit, links the first coil 2 and the second coil 3, generating an electromotive force in the first coil 2 and the second coil 3 with a magnitude corresponding to the change in linked magnetic flux, and an induced current flows. The first coil 2 and the second coil 3 then alternately supply high-frequency AC power to the load via the connection terminal 4. As a result, the power transmission unit 100 can receive power from the receiving unit A1.
[0030] (2-4) Connection terminals External devices are connected to connection terminal 4. More specifically, connection terminal 4 is an SMA type coaxial connector, etc.
[0031] For example, when the power transmission unit 100 is used as a power supply unit in a power supply system, an external device, such as a high-frequency oscillator, is connected to the connection terminal 4. Also, when the power transmission unit 100 is used as a power receiving unit in a power supply system, an external device, such as a load from a power receiving device, is connected to the connection terminal 4.
[0032] (2-5) Magnetic plate The magnetic plate 5 is a plate member formed of a magnetic material. In this disclosure, "magnetic material" refers to a material that can become magnetic. For example, when the frequency of the AC power supplied to the power supply system in which the power transmission unit 100 is used is 6.78 MHz, the magnetic material is preferably Ni-Zn ferrite. In other words, it is preferable that the magnetic plate 5 is formed of Ni-Zn ferrite. In this case, the magnetic permeability of the magnetic plate 5 is approximately 100 to 1000 [H / m].
[0033] As shown in Figure 5, the magnetic plate 5 of this embodiment is arranged such that the second coil 3 is positioned between the magnetic plate 5 and the dielectric substrate 1 in the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other. In short, the magnetic plate 5 of this embodiment is arranged so as to cover the second coil 3 from below in the opposing direction where the first surface 11 and the second surface 12 face each other. With this configuration, the magnetic plate 5 can block the magnetic flux generated around the first coil 2 and the second coil 3. That is, it has the effect of reducing the radiated magnetic field strength from the first coil 2 and the second coil 3. As a result, there is an advantage that it is possible to suppress malfunctions of devices placed near the first coil 2 and the second coil 3 due to the magnetic flux generated around the first coil 2 and the second coil 3.
[0034] In this embodiment, as shown in Figure 5, the magnetic plate 5 is arranged such that it forms a gap between itself and the second coil 3 in the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other (i.e., it does not come into contact with the second coil 3).
[0035] When the power transmission unit 100 is used in a power supply system, the other unit A1 in the power supply system is brought close to the power transmission unit 100 from the opposite side (i.e., from above) of the magnetic plate 5 in the opposing direction where the first surface 11 and the second surface 12 face each other.
[0036] (3) Effects The power transmission unit 100 according to this embodiment comprises a dielectric substrate 1, a first coil 2, and a second coil 3. The dielectric substrate 1 has opposing first surfaces 11 and second surfaces 12 and is made of a single layer. The first coil 2 is spirally patterned on the first surface 11 of the dielectric substrate 1. Similarly, the second coil 3 is spirally patterned on the second surface 12 of the dielectric substrate 1. As a result, when manufacturing the power transmission unit 100 of this embodiment, the process of bonding the substrate on which the first coil 2 is formed and the substrate on which the second coil 3 is formed to the dielectric substrate 1 is eliminated. In other words, the power transmission unit 100 of this embodiment has the advantage of simplifying manufacturing.
[0037] The power transmission unit 100 according to this embodiment further includes a connection terminal 4 to which an external device is connected. The first coil 2 has a first end E1 and a second end E2. The second coil 3 has a third end E3 and a fourth end E4. The first end E1 and the third end E3 are open ends. The second end E2 and the fourth end E4 are connected to the connection terminal 4. The second coil 3 is wound in the same direction as the first coil 2 when viewed through along the opposing direction where the first surface 11 and the second surface 12 face each other. This allows the first coil 2 and the second coil 3 to be patterned using the same pattern forming method. This makes pattern forming in the first coil 2 and the second coil 3 easier. As a result, the power transmission unit 100 of this embodiment has the advantage of being easier to manufacture.
[0038] In the power transmission unit 100 according to this embodiment, the dielectric substrate 1, the first coil 2, and the second coil 3 are formed from double-sided copper-clad laminates. This makes pattern formation in each of the first coil 2 and the second coil 3 easier. As a result, the power transmission unit 100 of this embodiment has the advantage of being easier to manufacture. Furthermore, the power transmission unit 100 of this embodiment also has the advantage of reducing manufacturing costs.
[0039] The power transmission unit 100 according to this embodiment further comprises a magnetic plate 5 made of a magnetic material. The magnetic plate 5 is arranged such that the second coil 3 is positioned between the magnetic plate 5 and the dielectric substrate 1 in the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other. As a result, the magnetic plate 5 can block the magnetic flux generated around the first coil 2 and the second coil 3. That is, it has the effect of reducing the radiated magnetic field strength from the first coil 2 and the second coil 3. As a result, there is an advantage that it is possible to suppress malfunctions of devices located near the first coil 2 and the second coil 3 due to the magnetic flux generated around the first coil 2 and the second coil 3.
[0040] (4) Modifications The embodiments described above are merely one of many embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objectives of the present disclosure are achieved. The following modifications may be implemented by combining them as appropriate. Components similar to those in the embodiments described above are denoted by the same reference numerals and their description is omitted.
[0041] (4-1) First Modification In the power transmission unit 100 of the above-described embodiment, the second coil 3 is wound in a different direction from the first coil 2 when viewed through along the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other. However, in the first modification power transmission unit 100a shown in Figure 6, the second coil 3a is wound in the same direction as the first coil 2 when viewed through along the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other. In other words, in the first modification power transmission unit 100a, the direction of the vortex of the second coil 3a is the same as the direction of the vortex of the first coil 2 when viewed through along the opposing direction where the first surface 11 and the second surface 12 face each other. With this configuration, the parasitic capacitance generated between the first coil 2 and the second coil 3a becomes larger. Therefore, the distance between the first coil 2 and the second coil 3a, that is, the dimension in the thickness direction of the dielectric substrate 1 can be reduced. As a result, the power transmission unit 100a of the first modification has the advantage of being able to be made smaller.
[0042] More specifically, as shown in Figure 6, the second coil 3a of the first modified example is wound counterclockwise (i.e., leftward) from the outside to the inside of the vortex when viewed from below. In other words, the direction of the vortex of the second coil 3a in this embodiment is such that, when viewed from below, the vortex is wound counterclockwise from the outside to the inside.
[0043] (4-2) Second Modified Example In the power transmission unit 100 of the above-described embodiment, the dielectric substrate 1, the first coil 2, and the second coil 3 are formed of a double-sided copper-clad laminate. However, in the power transmission unit 100 of the second modified example, the first coil 2 is formed of a conductive ink printed on the first surface 11 of the dielectric substrate 1, and the second coil 3 is formed of a conductive ink printed on the second surface 12 of the dielectric substrate 1. That is, the first coil 2 is pattern-formed by printing conductive ink on the first surface 11 of the dielectric substrate 1, and the second coil 3 is pattern-formed by printing conductive ink on the second surface 12 of the dielectric substrate 1.
[0044] It is desirable that the power transmission unit 100 of the above-described embodiment includes a housing that houses a double-sided copper-clad laminate in which the dielectric substrate 1, the first coil 2, and the second coil 3 are formed. On the other hand, in the power transmission unit 100 of the second modified example, by printing conductive ink on the above-described housing, the first coil 2 and the second coil 3 can be directly formed on the above-described housing. Therefore, in the power transmission unit 100 of the second modified example, the above-described housing does not require an internal space for housing the first coil 2 and the second coil 3, and has the effect of being able to reduce the height of the above-described housing. That is, the power transmission unit 100 of the second modified example has the advantage of being able to reduce the height.
[0045] (4-3) Third Modified Example In the power transmission unit 100 of the above-described embodiment, the magnetic plate 5 is arranged such that the second coil 3 is positioned between the magnetic plate 5 and the dielectric substrate 1 in the facing direction (vertical direction) in which the first surface 11 and the second surface 12 face each other. However, in the power transmission unit 100 of the third modified example, the magnetic plate 5 is arranged such that the first coil 2 is positioned between the magnetic plate 5 and the dielectric substrate 1 in the facing direction (vertical direction) in which the first surface 11 and the second surface 12 face each other. In short, the magnetic plate 5 of the third modified example is arranged so as to cover the first coil 2 from above in the facing direction in which the first surface 11 and the second surface 12 face each other. That is, the magnetic plate 5 may be arranged such that the first coil 2 or the second coil 3 is positioned between the magnetic plate 5 and the dielectric substrate 1 in the facing direction (vertical direction) in which the first surface 11 and the second surface 12 face each other.
[0046] In addition, when the power transmission unit 100 of the third modification is used in the power supply system, the counterpart unit A1 in the power supply system is brought closer to the power transmission unit 100 from the side opposite to the magnetic plate 5 (i.e., downward) in the facing direction where the first surface 11 and the second surface 12 face each other.
[0047] (4-4) Other Modifications Hereinafter, other modifications of the above-described embodiments will be listed. The following modifications may be realized in appropriate combinations.
[0048] In the above-described embodiment, the dielectric material forming the dielectric substrate 1 is a glass epoxy resin, but it may be a glass fluororesin, an ABS resin, a polycarbonate, or the like.
[0049] In the above-described embodiment, the first coil 2 is a film formed on the first surface 11 of the dielectric substrate 1. However, the first coil 2 may be formed using a conductive wire such as a copper wire. Specifically, a spiral groove may be formed on the first surface 11 of the dielectric substrate 1, and the first coil 2 may be formed by fitting a copper electric wire into the spiral groove.
[0050] Similarly, in the above-described embodiment, the second coil 3 is a film formed on the second surface 12 of the dielectric substrate 1. However, the second coil 3 may be formed using a conductive wire such as a copper wire. Specifically, a spiral groove may be formed on the second surface 12 of the dielectric substrate 1, and the second coil 3 may be formed by fitting a copper electric wire into the spiral groove.
[0051] The number of turns, pattern width, pitch, etc. in each of the first coil 2 and the second coil 3 may be appropriately changed and implemented.
[0052] In the above-described embodiment, each of the first coil 2 and the second coil 3 is patterned in an Archimedean spiral shape. However, each of the first coil 2 and the second coil 3 may be patterned in a spiral shape different from the Archimedean spiral shape.
[0053] In the above-described embodiment, the spiral shapes of the first coil 2 and the second coil 3 are circular spiral shapes with concentric circles. However, the spiral shapes of the first coil 2 and the second coil 3 may also be elliptical, with the two foci of the first coil 2 and the two foci of the second coil 3 overlapping in a plan view. Alternatively, the spiral shapes of the first coil 2 and the second coil 3 may be quadrilateral spiral shapes with their central axes coinciding. Here, "quadrilateral spiral shape" refers to a spiral shape that bends in a straight line. In other words, "quadrilateral spiral shape" is a spiral shape in which two adjacent straight sections in the direction of the spiral are connected so as to bend at 90°. That is, the spiral shapes of the first coil 2 and the second coil 3 are not limited.
[0054] In the above-described embodiment, the magnetic plate 5 is arranged such that it forms a gap between itself and the second coil 3 in the opposing direction (up and down direction) where the first surface 11 and the second surface 12 face each other (i.e., it does not come into contact with the second coil 3). However, the magnetic plate 5 may be arranged so as to come into contact with the second coil 3 in the opposing direction where the first surface 11 and the second surface 12 face each other. If the magnetic plate 5 is arranged so as to come into contact with the second coil 3, the design of the first coil 2 and the second coil 3 (number of turns, pattern width, pitch, etc.) must be changed.
[0055] The magnetic plate 5 may have a conductive film made of a conductive material such as aluminum on the side opposite to the first coil 2 and the second coil 3. As a result, the radiated magnetic field strength generated by the first coil 2 and the second coil 3 toward the magnetic plate 5 can be further reduced. This has the advantage of further suppressing malfunctions of devices located near the first coil 2 and the second coil 3.
[0056] In the above-described embodiment, the power transmission unit 100 includes a magnetic plate 5, but it does not necessarily have to include a magnetic plate 5.
[0057] (Summary) The power transmission unit (100; 100a) of the first embodiment comprises a dielectric substrate (1), a first coil (2), and a second coil (3; 3a). The dielectric substrate (1) has opposing first surfaces (11) and second surfaces (12) and consists of a single layer. The first coil (2) is patterned in a spiral shape on the first surface (11). The second coil (3; 3a) is patterned in a spiral shape on the second surface (12).
[0058] This embodiment has the advantage of simplifying the manufacturing process.
[0059] The power transmission unit (100) of the second embodiment further comprises a connection terminal (4) to which an external device is connected, as in the first embodiment. The first coil (2) has a first end (E1) and a second end (E2). The second coil (3) has a third end (E3) and a fourth end (E4). The first end (E1) and the third end (E3) are open ends. The second end (E2) and the fourth end (E4) are connected to the connection terminal (4). The second coil (3) is wound in a different direction from the first coil (2) when viewed through along the opposing direction in which the first surface (11) and the second surface (12) face each other.
[0060] This embodiment has the advantage of allowing for simpler manufacturing processes.
[0061] The power transmission unit (100a) of the third embodiment further comprises a connection terminal (4) to which an external device is connected, as in the first embodiment. The first coil (2) has a first end (E1) and a second end (E2). The second coil (3a) has a third end (E3) and a fourth end (E4). The first end (E1) and the third end (E3) are open ends. The second end (E2) and the fourth end (E4) are connected to the connection terminal (4). The second coil (3a) is wound in the same direction as the first coil (2) when viewed through along the opposing direction in which the first surface (11) and the second surface (12) face each other.
[0062] This embodiment has the advantage of being able to be made smaller.
[0063] In the fourth embodiment of the power transmission unit (100; 100a), in any one of the first to third embodiments, the dielectric substrate (1), the first coil (2), and the second coil (3; 3a) are formed from double-sided copper-clad laminates.
[0064] This embodiment has the advantage of allowing for simpler manufacturing processes.
[0065] In the power transmission unit (100; 100a) of the fifth embodiment, in any one of the first to third embodiments, the first coil (2) is formed of conductive ink printed on the first surface (11). The second coil (3; 3a) is formed of conductive ink printed on the second surface (12).
[0066] This embodiment has the advantage of being able to reduce the height.
[0067] A power transmission unit (100; 100a) of the sixth embodiment further comprises a magnetic plate (5) formed of a magnetic material in any one of the first to fifth embodiments. The magnetic plate (5) is arranged such that a first coil (2) or a second coil (3; 3a) is positioned between the magnetic plate (5) and a dielectric substrate (1) in a facing direction where the first surface (11) and the second surface (12) face each other.
[0068] This embodiment has the advantage of suppressing malfunctions of devices located near the first coil (2) and the second coil (3; 3a).
[0069] The configurations relating to the second to sixth aspects are not essential to the power transmission unit (100, 100a) and can be omitted as appropriate.
[0070] 100, 100a Power transmission unit 1 Dielectric substrate 2 First coil 3, 3a Second coil 4 Connection terminal 5 Magnetic plate 11 First surface 12 Second surface E1 First end E2 Second end E3 Third end E4 Fourth end
Claims
1. A power transmission unit comprising: a dielectric substrate consisting of a single layer and having opposing first and second surfaces; a first coil formed in a spiral pattern on the first surface; and a second coil formed in a spiral pattern on the second surface.
2. The power transmission unit according to claim 1, further comprising a connection terminal to which an external device is connected, wherein the first coil has a first end and a second end, the second coil has a third end and a fourth end, each of the first end and the third end is an open end, each of the second end and the fourth end is connected to the connection terminal, and the second coil is wound in a different direction from the first coil when viewed through along the opposing direction in which the first surface and the second surface face each other.
3. The power transmission unit according to claim 1, further comprising a connection terminal to which an external device is connected, wherein the first coil has a first end and a second end, the second coil has a third end and a fourth end, each of the first end and the third end is an open end, each of the second end and the fourth end is connected to the connection terminal, and the second coil is wound in the same direction as the first coil when viewed through along the opposing direction in which the first surface and the second surface face each other.
4. The power transmission unit according to any one of claims 1 to 3, wherein the dielectric substrate, the first coil, and the second coil are formed from a double-sided copper-clad laminate.
5. The power transmission unit according to any one of claims 1 to 3, wherein the first coil is formed of conductive ink printed on the first surface, and the second coil is formed of conductive ink printed on the second surface.
6. The power transmission unit according to any one of claims 1 to 5, further comprising a magnetic plate formed of a magnetic material, wherein the magnetic plate is arranged such that the first coil or the second coil is located between the magnetic plate and the dielectric substrate in a direction in which the first surface and the second surface face each other.