Coil component and wireless power transmission device having the same

Abstract

To provide a coil component which can increase the transmission efficiency in the center region of a charge area, while securing a large charge area.SOLUTION: A coil component 1 includes: a first magnetic body 31; a first coil C1 arranged on the first magnetic body 31; a second coil C2 arranged on the first coil C1, the outer size of the second coil being smaller than the outer size of the first coil C1; and a second magnetic body 32 arranged between the first coil C1 and the second coil C2, the outer size of the first coil being smaller than the outer size of the first coil C1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a coil component and a wireless power transmission device including the same.

Background Art

[0002] Patent Document 1 discloses a coil component for a wireless power transmission device.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the coil component described in Patent Document 1 is designed such that the wireless power transmission possible region (charge area) becomes wide, there is a problem that the transmission efficiency in the central region of the charge area decreases.

[0005] Therefore, an object of the present disclosure is to provide a coil component and a wireless power transmission device including the same in which the transmission efficiency in the central region of the charge area is increased while securing a wide charge area.

Means for Solving the Problems

[0006] A coil component according to an embodiment of the present disclosure includes a first magnetic body, a first coil disposed on the first magnetic body, a second coil disposed on the first coil and having an outer size smaller than that of the first coil, and a second magnetic body disposed between the first coil and the second coil and having an outer size smaller than that of the first coil.

Effects of the Invention

[0007] According to the present disclosure, it is possible to increase the transmission efficiency in the central region of the charging area while securing a wide charging area.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] FIG. 1 is a schematic cross-sectional view for explaining the structure of the coil component 1 according to the first embodiment of the present disclosure. Further, FIG. 2 is a schematic plan view of the coil component 1 viewed from the coil axis direction. FIG. 1 shows a schematic cross-section along a line extending in the Y direction through the center of the coil component 1 shown in FIG. 2.

[0011] As shown in FIGS. 1 and 2, the coil component 1 according to one embodiment includes a first magnetic body 31, a first coil C1 disposed on the first magnetic body 31, a second coil C2 disposed on the first coil C1, a second magnetic body 32 disposed between the first coil C1 and the second coil C2, and a magnet 40 disposed outside in the radial direction of the second coil C2. The first coil C1 is composed of coil patterns 100 and 200 provided on the surfaces 11 and 12 of a base material 10 made of a PET film or the like, respectively. The second coil C2 is composed of coil patterns 400 and 500 provided on the surfaces 21 and 22 of a base material 20 made of a PET film or the like, respectively. In FIG. 1, for convenience of explanation, there is a gap between the members constituting the coil component 1, but these constituent members may be fixed to each other using an adhesive sheet. For example, the first coil C1 may be adhesively fixed to the first magnetic body 31 via an adhesive sheet (not shown), the second magnetic body 32 may be adhesively fixed to the first coil C1 via an adhesive sheet (not shown), and the second coil C2 and the magnet 40 may be adhesively fixed to the second magnetic body 32 and the first coil C1 via an adhesive sheet (not shown).

[0012] The first coil C1 and the second coil C2 both function as power transmission coils for wireless power transmission. The coil axis directions of the first coil C1 and the second coil C2 are in the Z direction. The first magnetic body 31, the first coil C1, the second magnetic body 32, and the second coil C2 are laminated in this order in the Z direction. The first magnetic body 31 and the second magnetic body 32 may be constituted by a sheet-like magnetic material having a relative permeability of 300 or more. When the power transmission frequency using the first coil C1 and the second coil C2 is about 100 to 200 kHz, by using a magnetic material having a relative permeability of 300 or more as the material of the first magnetic body 31 and the second magnetic body 32, it becomes possible to obtain a high inductance. On the other hand, when performing information communication using a coil such as near-field communication (NFC), the communication frequency is generally in the MHz band (13.56 MHz in NFC), and when using a magnetic material having a relative permeability of 300 or more, the loss becomes large. Therefore, it is not appropriate to use such a magnetic material.

[0013] In actual use, an electronic device 60 including a power receiving coil C3 is placed on the placement surface S shown in FIG. 1, and power is wirelessly transmitted from the coil component 1 to the electronic device 60 by the coupling of the first coil C1 or the second coil C2, which is a power transmission coil, and the power receiving coil C3. The first magnetic body 31 and the second magnetic body 32 function as magnetic paths for magnetic fluxes generated by the first coil C1 and the second coil C2. The first coil C1 is mainly used to secure a wide charging area, and the second coil C2 is mainly used to improve the transmission efficiency in the central region of the charging area.

[0014] The outer dimension WC2A of the second coil C2 is smaller than the outer dimension WC1A of the first coil C1. The outer dimension WC1A is the dimension of the first coil C1 in the radial direction. As shown in FIG. 2, the outer dimension WC1A in the X direction may be smaller than the outer dimension WC1A in the Y direction. In this case, the outer dimension WC1A of the first coil C1 may be defined by the dimension in the X direction where the size is the smallest. The outer dimension WC2A is the dimension of the second coil C2 in the radial direction. In the example shown in FIG. 2, the outer shape of the second coil C2 is circular, but similar to the first coil C1, it may have a shape in which the outer dimension WC2A of the second coil C2 changes depending on the direction.

[0015] The first coil C1 and the second coil C2 may be arranged such that the first opening region D1 surrounded by the winding region of the first coil C1 and the second opening region D2 surrounded by the winding region of the second coil C2 overlap in the Z direction. The winding region of the first coil C1 is the region where the conductor pattern constituting the first coil C1 exists, and refers to the region between the innermost turn and the outermost turn. The winding region of the second coil C2 is the region where the conductor pattern constituting the second coil C2 exists, and refers to the region between the innermost turn and the outermost turn. In this case, the first coil C1 and the second coil C2 may be arranged such that their central axes coincide. The size WC1B of the first opening region D1 and the size WC2B of the second opening region D2 may be different from each other.

[0016] The size WC1B of the first opening region D1 may differ in size in the X direction and the Y direction. In this case, the size WC1B of the first opening region D1 may be defined by the smallest size in the radial direction. In the example shown in FIG. 2, the shape of the second opening region D2 is circular like the outer shape of the second coil C2, and the size in the X direction and the size in the Y direction are the same, but the size in the X direction and the size in the Y direction of the second opening region D2 may differ. In this case, the size WC2B of the second opening region D2 may be defined by the smallest size in the radial direction. The second magnetic body 32 may be arranged so as to overlap both the first and second opening regions D1 and D2.

[0017] The outer size W31 of the first magnetic body 31 is larger than the outer size WC1A of the first coil C1, and the entire first coil C1 has an overlap with the first magnetic body 31 in the Z direction. The outer size W32 of the second magnetic body 32 is smaller than the outer size WC1A of the first coil C1, and a part or the whole of the first coil C1 does not have an overlap with the second magnetic body 32 in the Z direction. Since the second magnetic body 32 is located between the first coil C1 and the mounting surface S, if the first coil C1 is completely covered by the second magnetic body 32, the efficiency of power transmission decreases. However, in this embodiment, since the outer size W32 of the second magnetic body 32 is smaller than the outer size WC1A of the first coil C1, it is suppressed from being inhibited by the second magnetic body 32, and power transmission using the first coil C1 becomes possible. The outer size W32 of the second magnetic body 32 may be smaller than the outer size WC2A of the second coil C2. In this case, a part or the whole of the second coil C2 does not have an overlap with the second magnetic body 32 in the Z direction. As shown in FIG. 2, the outer size W31 of the first magnetic body 31 may be smaller in the X direction than in the Y direction corresponding to the difference in size in the radial direction of the outer size WC1A of the first coil C1. In this case, the outer size W31 of the first magnetic body 31 may be defined by the size in the Y direction where the size is the smallest. Also, the second magnetic body 32 may be circular corresponding to the outer shape of the second coil C2.

[0018] The magnet 40 is arranged in an annular shape along the outer shape of the second coil C2 so as not to overlap with the second coil C2. Here, the annular arrangement includes not only the state of being arranged like a complete ring but also the state where a part around the second coil C2 is removed as shown in FIG. 2. The magnet 40 has at least a fixed positional relationship with the second coil C2 in the XY plane direction, and positions the second coil C2 and the power receiving coil C3 by the attractive force acting between the magnet 40 and the magnet 61 provided in the electronic device 60. In the examples shown in FIGS. 1 and 2, the magnet 40 is supported by a support 50 made of resin or the like. The magnet 40 may be arranged so that the whole overlaps with the winding region of the first coil C1. If the whole of the magnet 40 is arranged to overlap with the winding region of the first coil C1, since the first opening region D1 of the first coil C1 with a high magnetic flux density is not covered by the magnet 40, it is possible to suppress the loss due to the magnet 40.

[0019] FIG. 3 is a schematic plan view showing the shape of the conductor pattern formed on one surface 11 of the base material 10.

[0020] As shown in FIG. 3, on one surface 11 of the base material 10, a coil pattern 100 constituting a part of the first coil C1 and terminal electrodes E1, E2 are formed. The coil pattern 100 has a six-turn configuration consisting of turns 110, 120, 130, 140, 150, 160. The turn 110 is located on the outermost periphery, and the turn 160 is located on the innermost periphery. Among these, the turns 110, 120, 130, 140, 150 are radially divided into four by three spiral slits. On the other hand, the turn 160 is radially divided into two by one spiral slit. As a result, the turn 110 is divided into four at lines 111 to 114, the turn 120 is divided into four at lines 121 to 124, the turn 130 is divided into four at lines 131 to 134, the turn 140 is divided into four at lines 141 to 144, the turn 150 is divided into four at lines 151 to 154, and the turn 160 is divided into two at lines 161, 162.

[0021] Lines 111, 121, 131, 141, 151, 161 are continuous lines spirally wound in 6 turns and are located at the outermost periphery in each turn. Lines 112, 122, 132, 142, 152, 162 are continuous lines spirally wound in 6 turns and are located second from the outermost periphery in each turn. Lines 113, 123, 133, 143, 153 are continuous lines spirally wound in 5 turns and are located second from the innermost periphery in each turn. Lines 114, 124, 134, 144, 154 are continuous lines spirally wound in 5 turns and are located at the innermost periphery in each turn.

[0022] The outer peripheral ends of Lines 111 to 114 are commonly connected to the terminal electrode E1. On the other hand, the inner peripheral ends of Lines 161, 162, 153, 154 are respectively connected to the through-hole conductors 301 to 304 penetrating the base material 10.

[0023] FIG. 4 is a schematic plan view showing the shape of the conductor pattern formed on the other surface 12 of the base material 10, showing the state seen from the one surface 11 side of the base material 10, that is, the state seen through the base material 10.

[0024] As shown in FIG. 4, on the other surface 12 of the base material 10, a coil pattern 200 that constitutes the remaining part of the first coil C1 is formed. The basic pattern shape of the coil pattern 200 is the same as the pattern shape of the coil pattern 100. The coil pattern 200 has a six-turn configuration consisting of turns 210, 220, 230, 240, 250, and 260, with turn 210 located on the outermost periphery and turn 260 located on the innermost periphery. Among these, turns 210, 220, 230, 240, and 250 are radially divided into four parts by three spiral slits. On the other hand, turn 260 is radially divided into two parts by one spiral slit. As a result, turn 210 is divided into four parts at lines 211 to 214, turn 220 is divided into four parts at lines 221 to 224, turn 230 is divided into four parts at lines 231 to 234, turn 240 is divided into four parts at lines 241 to 244, turn 250 is divided into four parts at lines 251 to 254, and turn 260 is divided into two parts at lines 261 and 262.

[0025] Lines 211, 221, 231, 241, 251, and 261 are continuous lines spirally wound six turns, and are located on the outermost periphery in each turn. Lines 212, 222, 232, 242, 252, and 262 are continuous lines spirally wound six turns, and are located second from the outermost periphery in each turn. Lines 213, 223, 233, 243, and 253 are continuous lines spirally wound five turns, and are located second from the innermost periphery in each turn. Lines 214, 224, 234, 244, and 254 are continuous lines spirally wound five turns, and are located on the innermost periphery in each turn.

[0026] The outer peripheral ends of lines 211 to 214 are commonly connected to the terminal electrode E2 via through-hole conductors. On the other hand, the inner peripheral ends of lines 261, 262, 253, and 254 are connected to through-hole conductors 304, 303, 302, and 301, respectively. As a result, a first coil C1 having a configuration in which four 11-turn lines are connected in parallel is connected between the terminal electrode E1 and the terminal electrode E2. Thus, the first coil C1 is a planar spiral coil.

[0027] FIG. 5 is a schematic plan view showing the shape of a conductor pattern formed on one surface 21 of the base material 20.

[0028] As shown in FIG. 5, a coil pattern 400 constituting a part of the second coil C2 and a terminal electrode E3 are formed on one surface 21 of the base material 20. The coil pattern 400 has a six-turn configuration consisting of turns 410, 420, 430, 440, 450, and 460. The turn 410 is located on the outermost periphery, and the turn 460 is located on the innermost periphery. Each of the turns 410, 420, 430, 440, 450, and 460 is radially divided into three parts by two spiral slits. As a result, the turn 410 is divided into lines 411 to 413, the turn 420 is divided into lines 421 to 423, the turn 430 is divided into lines 431 to 433, the turn 440 is divided into lines 441 to 443, the turn 450 is divided into lines 451 to 453, and the turn 460 is divided into lines 461 to 463.

[0029] Lines 411, 421, 431, 441, 451, and 461 are continuous lines spirally wound six times and are located on the outermost periphery in each turn. Lines 412, 422, 432, 442, 452, and 462 are continuous lines spirally wound six times and are located in the middle in the radial direction in each turn. Lines 413, 423, 433, 443, 453, and 463 are continuous lines spirally wound six times and are located on the innermost periphery in each turn.

[0030] The outer peripheral ends of lines 411 to 413 are commonly connected to the terminal electrode E3. On the other hand, the inner peripheral ends of lines 461 to 463 are respectively connected to through-hole conductors 601 to 603 that penetrate the base material 20.

[0031] FIG. 6 is a schematic plan view showing the shape of the conductor pattern formed on the other surface 22 of the base material 20, showing the state as viewed from the one surface 21 side of the base material 20, that is, the state as viewed through the base material 20.

[0032] As shown in FIG. 6, a coil pattern 500 that constitutes the remaining portion of the second coil C2 is formed on the other surface 22 of the base material 20. The basic pattern shape of the coil pattern 500 is the same as the pattern shape of the coil pattern 400. The coil pattern 500 has a six-turn configuration consisting of turns 510, 520, 530, 540, 550, and 560, with turn 510 located at the outermost periphery and turn 560 located at the innermost periphery. Turns 510, 520, 530, 540, 550, and 560 are each divided into three in the radial direction by two spiral slits. As a result, turn 510 is divided into lines 511 to 513, turn 520 is divided into lines 521 to 523, turn 530 is divided into lines 531 to 533, turn 540 is divided into lines 541 to 543, turn 550 is divided into lines 551 to 553, and turn 560 is divided into lines 561 to 563.

[0033] Lines 511, 521, 531, 541, 551, and 561 are continuous lines spirally wound six times and are located at the outermost periphery in each turn. Lines 512, 522, 532, 542, 552, and 562 are continuous lines spirally wound six times and are located in the middle in the radial direction in each turn. Lines 513, 523, 533, 543, 553, and 563 are continuous lines spirally wound six times and are located at the innermost periphery in each turn.

[0034] The outer peripheral ends of lines 511 to 513 are commonly connected to the terminal electrode E4. On the other hand, the inner peripheral ends of lines 561 to 563 are respectively connected to the through-hole conductors 603, 602, 601 that penetrate the base material 20. As a result, between the terminal electrode E3 and the terminal electrode E4, a second coil C2 having a configuration in which three lines of 12 turns are connected in parallel is connected. Thus, the second coil C2 is a planar spiral coil. Further, the terminal electrode E3 is also provided on the other surface 22 of the base material 20, and the terminal electrodes E3 provided on the surfaces 21 and 22 are connected via the through-hole conductor 604. Similarly, the terminal electrode E4 is also provided on one surface 21 of the base material 20, and the terminal electrodes E4 provided on the surfaces 21 and 22 are connected via the through-hole conductor 605.

[0035] FIG. 7 is a schematic diagram for explaining an example of the planar positional relationship among the first coil C1, the second coil C2, the first magnetic body 31, and the second magnetic body 32.

[0036] In FIG. 7, the outer peripheral edge C1A of the first coil C1, the inner peripheral edge C1B of the first coil C1, the outer peripheral edge C2A of the second coil C2, and the inner peripheral edge C2B of the second coil C2 are shown by solid lines, and the outer peripheral edge 31A of the first magnetic body 31 and the outer peripheral edge 32A of the second magnetic body 32 are shown by broken lines.

[0037] In the example shown in FIG. 7, the entire outer peripheral edge C1A of the first coil C1 is located inside the outer peripheral edge 31A of the first magnetic body 31. That is, the entire first coil C1 overlaps the first magnetic body 31 in the Z direction. Further, the outer peripheral edge C2A of the second coil C2 is entirely located inside the outer peripheral edge C1A of the first coil C1. However, a part of the winding region of the second coil C2 overlaps the first opening region D1 of the first coil C1 in the Z direction. While the second coil C2 is circular, the planar shape of the first coil C1 has a longitudinal direction, and further, the first opening region D1 also has an elongated shape in the longitudinal direction of the first coil C1.

[0038] In the example shown in FIG. 7, the first opening region D1 and the second opening region D2 have an overlap in the Z direction. Specifically, a part of the first opening region D1 overlaps with the second opening region D2, and the remaining part of the first opening region D1 overlaps with the winding region of the second coil C2. Similarly, a part of the second opening region D2 overlaps with the first opening region D1, and the remaining part of the second opening region D2 overlaps with the winding region of the first coil C1.

[0039] In the example shown in FIG. 7, while both the outer peripheral edge C1A and the inner peripheral edge C1B of the first coil C1 are non-circular, the outer peripheral edge C2A of the second coil C2, the inner peripheral edge C2B of the second coil C2, and the outer peripheral edge 32A of the second magnetic body 32 are all circular. The central axis of the first coil C1 and the central axis of the second coil C2 may coincide with the center of the second magnetic body 32. In the example shown in FIG. 7, the entire second opening region D2 of the second coil C2 overlaps with the second magnetic body 32 in the Z direction. A part of the second magnetic body 32 overlaps with the winding region of the second coil C2. A part of the first opening region D1 of the first coil C1 overlaps with the second magnetic body 32 in the Z direction, and the remaining part does not overlap with the second magnetic body 32. A part of the second magnetic body 32 overlaps with the winding region of the first coil C1.

[0040] The second magnetic body 32 mainly functions as a magnetic path for the magnetic flux generated by the second coil C2. Since the second magnetic body 32 is disposed on the side opposite to the mounting surface S as viewed from the second coil C2, the larger the outer shape size W32 of the second magnetic body 32, the higher the power transmission efficiency between the second coil C2 and the power receiving coil C3. The second magnetic body 32 also functions as a magnetic path for the magnetic flux generated by the first coil C1. However, since the second magnetic body 32 is disposed closer to the mounting surface S than the first coil C1, when the outer shape size W32 of the second magnetic body 32 increases, the power transmission efficiency between the first coil C1 and the power receiving coil C3 decreases.

[0041] FIG. 8 is a graph showing the relationship between the size of the second magnetic body 32 and the magnetic field strength.

[0042] In FIG. 8, the horizontal axis indicates the ratio (W32 / WC2B) of the outer dimension W32 of the second magnetic body 32 to the size WC2B of the second opening region D2, and the vertical axis indicates the relative magnetic field strength of the first coil C1 and the second coil C2. Here, the relative magnetic field strength indicates the relative strength of the magnetic field reaching the power receiving coil C3 when a unit current is passed through the first coil C1 or the second coil C2, which is a power transmitting coil, and a value of 1 or more is required for performing good power transmission.

[0043] As shown in FIG. 8, as the outer dimension W32 of the second magnetic body 32 increases, the magnetic field strength of the second coil C2 increases. If the value of W32 / WC2B is 0.8 or more, the normalized value of the magnetic field strength of the second coil C2 becomes 1 or more. Considering this, the outer dimension W32 of the second magnetic body may be 0.8 times or more the size of the second opening region D2. In particular, when the outer dimension W32 of the second magnetic body is larger than the size of the second opening region D2, it becomes possible to obtain higher power transmission efficiency. In this case, if the central axis of the second coil C2 and the center of the second magnetic body 32 coincide, the second magnetic body 32 will overlap with the entire second opening region D2, and all of the magnetic flux passing through the second opening region D2 will pass through the second magnetic body 32, so that it becomes possible to obtain a high inductance.

[0044] On the other hand, as the outer dimension W32 of the second magnetic body 32 increases, the magnetic field strength of the first coil C1 decreases. When the value of W32 / WC2B exceeds 1.4, the normalized value of the magnetic field strength of the first coil C1 becomes less than 1. Considering this, the outer dimension W32 of the second magnetic body may be 1.4 times or less the size of the second opening region D2.

[0045] As described above, the coil component 1 according to the present embodiment includes a first coil C1 having a large outer size WC1A and a second coil C2 having an outer size WC2A smaller than that of the first coil C1, and these are arranged so as to overlap each other. Therefore, it is possible to secure a wide charging area and prevent a decrease in transmission efficiency in the central region of the charging area. Moreover, since the second magnetic body 32 is provided between the first coil C1 and the second coil C2, the power transmission efficiency of the second coil C2 is enhanced. Further, since the outer size W32 of the second magnetic body 32 is smaller than the outer size WC1A of the first coil C1, it is suppressed from being inhibited by the second magnetic body 32, and power transmission by the first coil C1 is realized.

[0046] FIG. 9 is a schematic cross-sectional view for explaining the structure of the coil component 2 according to the second embodiment of the present disclosure. FIG. 10 is a schematic diagram for explaining the planar positional relationship among the first coil C1, the second coil C2, the first magnetic body 31, and the second magnetic body 32 in the second embodiment.

[0047] As shown in FIGS. 9 and 10, the feature of the coil component 2 according to the present embodiment is that the coil axis of the first coil C1 and the coil axis of the second coil C2 do not coincide, and the position of the coil axis ZC2 of the second coil C2 with respect to the central position in the longitudinal direction of the first coil C1 is offset to one side in the longitudinal direction of the first coil C1. The coil axis of the second coil C2 may overlap the winding region of the first coil C1, or may overlap the first opening region D1 of the first coil C1. Other configurations are the same as those of the coil component 1 according to the first embodiment.

[0048] In the example shown in FIG. 10, the entire outer peripheral edge C1A of the first coil C1 is located inside the outer peripheral edge 31A of the first magnetic body 31. That is, the entire first coil C1 overlaps the first magnetic body 31 in the Z direction. Also, the outer peripheral edge C2A of the second coil C2 may be entirely located inside the outer peripheral edge C1A of the first coil C1, or a part thereof may be located outside the outer peripheral edge C1A of the first coil C1.

[0049] In the example shown in FIG. 10, the first opening region D1 and the second opening region D2 have an overlap in the Z direction. Specifically, a part of the second opening region D2 overlaps with one end of the first opening region D1 in the longitudinal direction, and the remaining part of the second opening region D2 overlaps with the winding region of the first coil C1. A part of the winding region of the second coil C2 overlaps with the first opening region D1 of the first coil C1 in the Z direction. The other end of the first opening region D1 in the longitudinal direction does not overlap with the winding region of the second coil C2.

[0050] In the example shown in FIG. 10, both the outer peripheral edge C1A of the first coil C1 and the inner peripheral edge C1B of the first coil C1 are non-circular and have a longitudinal direction, while the outer peripheral edge C2A of the second coil C2, the inner peripheral edge C2B of the second coil C2, and the outer peripheral edge 32A of the second magnetic body 32 are all circular. The coil axis of the second coil C2 coincides with the center of the second magnetic body 32, but the coil axis of the first coil C1 does not coincide with the center of the second magnetic body 32. A part of the second magnetic body 32 overlaps with the winding region of the second coil C2. One end of the first opening region D1 of the first coil C1 in the longitudinal direction overlaps with the second magnetic body 32 in the Z direction, and the remaining part does not overlap with the second magnetic body 32. A part of the second magnetic body 32 overlaps with the winding region of the first coil C1.

[0051] As described above, in the coil component 2 according to the present embodiment, since the position of the coil axis of the second coil C2 with respect to the central position in the longitudinal direction of the first coil C1 is offset, the center of the charging area can be shifted from the center of the first coil C1. Therefore, even when the power receiving coil C3 is arranged offset from the center of the coil component 2, a decrease in the power transmission efficiency to the power receiving coil C3 can be suppressed.

[0052] FIG. 11 is a schematic diagram showing the positional relationship between the smartphone and the coil component 2 when the coil component 2 according to the second embodiment is applied to the charging system of the smartphone.

[0053] As shown in FIG. 11, when the electronic device 60 including the power receiving coil C3 is a part of the smartphone 90, power is wirelessly transmitted from the coil component 2 to the electronic device 60 by coupling the first coil C1 or the second coil C2, which is the power transmission coil, with the power receiving coil C3, and the power is charged to a battery (not shown) in the smartphone 90.

[0054] In many cases, a camera lens 90c is provided on the back surface 90a side of the smartphone 90, and particularly recently, the camera lens 90c may protrude greatly from the back surface 90a. Thus, when there is a protruding portion on the back surface 90a of the smartphone 90, since the housing that houses the coil component 2 interferes with the camera lens 90c of the smartphone 90, depending on the position of the power receiving coil C3 in the smartphone 90, it may not be possible to align the coil axis of the power receiving coil C3 on the smartphone 90 side with the center of the power transmission side coil component 2. Further, even if the electronic device 60 is provided with an alignment magnet 61, the magnet 61 may not function effectively due to interference by the camera lens 90c.

[0055] However, when the coil axis of the second coil C2 in the coil component 2 is offset with respect to the first coil C1 as in the present embodiment, even if the power receiving coil C3 is disposed offset from the center of the coil component 1, a decrease in the power transmission efficiency to the power receiving coil C3 can be suppressed. That is, it is not necessary to align the coil axis of the power receiving coil C3 with the coil axis of the first coil C1, and it is only necessary to align it with the coil axis of the second coil C2 disposed offset, so that the charging efficiency of the smartphone 90 can be improved.

[0056] FIG. 12 is a block diagram of a wireless power transmission device 70 using the coil component 1 or 2.

[0057] The wireless power transmission device 70 shown in FIG. 12 includes a coil component 1 or 2 having a first coil C1 and a second coil C2, a power transmission circuit 71 connected to the first coil C1, a power transmission circuit 72 connected to the second coil C2, and a control circuit 73 for controlling the power transmission circuits 71 and 72. The control circuit 73 exclusively activates one of the power transmission circuits 71 and 72, thereby realizing power transmission using the first coil C1 or power transmission using the second coil C2.

[0058] FIG. 13 is a block diagram of a wireless power transmission device 80 using the coil component 1 or 2.

[0059] The wireless power transmission device 80 shown in FIG. 13 includes a coil component 1 or 2 having a first coil C1 and a second coil C2, a power transmission circuit 81 connected to the first coil C1 and the second coil C2, a switch 82 connected between the first coil C1 and the second coil C2 and the power transmission circuit 81, and a control circuit 83 for controlling the power transmission circuit 81 and the switch 82. The control circuit 83 connects one of the first coil C1 and the second coil C2 to the power transmission circuit 81 by switching the switch 82. Thereby, power transmission using the first coil C1 or power transmission using the second coil C2 can be performed.

[0060] As described above, the embodiments of the present disclosure have been described. However, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present disclosure, and it goes without saying that those are also included in the scope of the present disclosure.

[0061] For example, the first coil C1 and the second coil C2 may be composed of covered conductors instead of conductor patterns formed on the surface of the base material. Further, the conductor patterns provided on the surfaces 11 and 12 of the base material 10 and the surfaces 21 and 22 of the base material 20 may be provided on the surfaces 11 and 12 of the base material 10 and the surfaces 21 and 22 of the base material 20 via other material layers containing resin therebetween.

[0062] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0063] A coil component according to an embodiment of the present disclosure includes a first magnetic body, a first coil disposed on the first magnetic body, a second coil disposed on the first coil and having an outer size smaller than that of the first coil, and a second magnetic body disposed between the first coil and the second coil and having an outer size smaller than that of the first coil. According to this, it is possible to prevent a decrease in transmission efficiency in the central region of the charge area while securing a wide charge area.

[0064] In the above coil component, the first coil and the second coil are arranged such that a first opening region surrounded by the winding region of the first coil and a second opening region surrounded by the winding region of the second coil overlap, and the second magnetic body may be arranged to overlap the first and second opening regions. According to this, since more magnetic flux passes through the second magnetic body, it is possible to obtain a high inductance.

[0065] In the above coil component, the outer size of the second magnetic body may be smaller than the outer size of the second coil. According to this, it is possible to suppress a decrease in the transmission efficiency of the first coil.

[0066] In the above coil component, the outer size of the second magnetic body may be 0.8 times or more and 1.4 times or less the size of the second opening region. According to this, it is possible to achieve both the transmission efficiency of the first coil and the transmission efficiency of the second coil.

[0067] In the above coil component, the outer size of the second magnetic body may be larger than the size of the second opening region. According to this, it is possible to increase the transmission efficiency in the central region of the charge area.

[0068] In the above coil component, the second magnetic body may overlap with the entire second opening region. According to this, it becomes possible to further improve the transmission efficiency in the central region of the charge area.

[0069] In the above coil component, the second magnetic body may overlap with a part of the winding region of the first coil and may not overlap with a part of the first opening region. According to this, it becomes possible to achieve both the transmission efficiency of the first coil and the transmission efficiency of the second coil.

[0070] In the above coil component, the relative permeability of the first magnetic body may be 300 or more. According to this, it becomes possible to set the power transmission frequency using the first coil to a frequency suitable for wireless power transmission.

[0071] In the above coil component, the relative permeability of the second magnetic body may be 300 or more. According to this, it becomes possible to set the power transmission frequency using the second coil to a frequency suitable for wireless power transmission.

[0072] The above coil component may further include a magnet arranged along the outer shape of the second coil. According to this, it becomes possible to position the power receiving coil.

[0073] In the above coil component, the magnet may entirely overlap with the winding region of the first coil. According to this, it becomes possible to suppress the loss of the first coil due to the magnet.

[0074] In the above coil component, the planar shape of the first coil has a longitudinal direction, and the position of the coil axis of the second coil with respect to the central position in the longitudinal direction of the first coil may be offset to one side in the longitudinal direction. According to this, even when the power receiving coil is arranged offset from the center of the coil component, it is possible to suppress a decrease in the power transmission efficiency to the power receiving coil.

[0075] In the above coil component, the first opening region surrounded by the winding region of the first coil has an elongated shape in the longitudinal direction of the first coil, and the second opening region surrounded by the winding region of the second coil may overlap with one end of the first opening region in the longitudinal direction. Even with such a configuration, a decrease in the power transmission efficiency to the power receiving coil can be suppressed.

[0076] In the above coil component, the coil axis of the second coil may overlap with the winding region of the first coil. Even with such a configuration, a decrease in the power transmission efficiency to the power receiving coil can be suppressed.

[0077] The wireless power transmission device according to an embodiment of the present disclosure includes any one of the above coil components and a power transmission circuit connected to the first and second coils. According to this, it is possible to provide a wireless power transmission device with a wide charging area and high transmission efficiency in the central region of the charging area.

Description of Reference Numerals

[0078] 1, 2 Coil components 10, 20 Base materials 11, 12, 21, 22 Surfaces 31 First magnetic body 31A Outer peripheral edge of the first magnetic body 32 Second magnetic body 32A Outer peripheral edge of the second magnetic body 40 Magnet 50 Support 60 Electronic device 61 Magnet 70, 80 Wireless power transmission devices 71, 72, 81 Power transmission circuits 73, 83 Control circuits 82 Switch 90 Smartphone 90a Back surface of the smartphone 90c Camera lens 100, 200, 400, 500 Coil patterns 110, 120, 130, 140, 150, 160, 210, 220, 230, 240, 250, 260, 410, 420, 430, 440, 450, 460, 510, 520, 530, 540, 550, 560 turns 111~114, 121~124, 131~134, 141~144, 151~154, 161, 162, 211~214, 221~224, 231~234, 241~244, 251~254, 261, 262, 411~413, 421~423, 431~433, 441~443, 451~453, 461~463, 511~513, 521~523, 531~533, 541~543, 551~553, 561~563 lines 301~304, 601~605 through-hole conductors C1 First coil C1A Outer peripheral edge of the first coil C1B Inner peripheral edge of the first coil C2 Second coil C2A Outer peripheral edge of the second coil C2B Inner peripheral edge of the second coil C3 Power receiving coil D1 First opening region D2 Second opening region E1~E4 Terminal electrodes S Mounting surface ZC1 Coil axis of the first coil ZC2 Coil axis of the second coil

Claims

1. A first magnetic body; a first coil disposed on the first magnetic body; a second coil disposed on the first coil and having an outer size smaller than an outer size of the first coil; a second magnetic body disposed between the first coil and the second coil and having an outer size smaller than an outer size of the first coil; A coil component comprising:

2. the first coil and the second coil are arranged such that a first opening region surrounded by a winding region of the first coil and a second opening region surrounded by a winding region of the second coil overlap with each other; The second magnetic body is disposed so as to overlap the first and second opening regions. The coil component according to claim 1 .

3. The outer size of the second magnetic body is smaller than the outer size of the second coil. The coil component according to claim 2 .

4. The outer size of the second magnetic body is 0.8 times or more and 1.4 times or less than the size of the second opening region. The coil component according to claim 3 .

5. The outer size of the second magnetic body is larger than the size of the second opening region. The coil component according to claim 4 .

6. The second magnetic body overlaps the entire second opening region. The coil component according to claim 5 .

7. the second magnetic body overlaps a portion of a winding region of the first coil and does not overlap a portion of the first opening region; The coil component according to claim 2 .

8. The relative permeability of the first magnetic body is 300 or more. The coil component according to claim 1 .

9. The relative permeability of the second magnetic body is 300 or more. The coil component according to claim 8.

10. Further comprising a magnet disposed along the outer shape of the second coil. The coil component according to claim 1 .

11. The magnet entirely overlaps with a winding region of the first coil. The coil component according to claim 10.

12. The planar shape of the first coil has a longitudinal direction, a position of a coil axis of the second coil relative to a center position of the first coil in the longitudinal direction is offset to one side in the longitudinal direction; The coil component according to claim 1 .

13. a first opening region surrounded by a winding region of the first coil has an elongated shape in the longitudinal direction; a second opening region surrounded by a winding region of the second coil overlaps with one end of the first opening region in the longitudinal direction; The coil component according to claim 12.

14. A coil axis of the second coil overlaps with a winding region of the first coil. The coil component according to claim 12.

15. The coil component according to any one of claims 1 to 14, a power transmitting circuit connected to the first and second coils.

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