COIL COMPONENT AND DEVICE FOR WIRELESS ENERGY TRANSMISSION WITH THIS COMPONENT

Abstract

A coil component (100), comprising: a substrate (101) and a planar spiral coil pattern (CP1, CP2) arranged on a surface of the substrate (101), wherein the coil pattern (CP1, CP2) has a higher roundness in its inner shape (ID) than in its outer shape (OD), wherein the outer shape (OD) of the coil pattern (CP1, CP2) has a first and a second section (311, 312) extending in a first direction, a third section (313) extending in a second direction perpendicular to the first direction, a fourth section (314) arranged between the first and the second section (311, 312) extending straight and obliquely to the first direction, and a fifth section (315) arranged between the second and the third section (312, 313) being curved such that its direction of extension changes from the first direction to the second direction, where the first, fourth, second, fifth and third sections (311, 314, 312, 315, 313) follow one another in this order, wherein the inner shape (ID) of the coil pattern (CP1, CP2) has a sixth section (316) corresponding to the first section (311) and extending in the first direction, a seventh section (317) corresponding to the third section (313) and extending in the second direction (312), an eighth section (318) corresponding to the fourth section (314) and extending straight and obliquely to the first direction, and a ninth section (319) corresponding to the fifth section (315) and curved such that its direction of extension changes from the first direction to the second direction, where the sixth, eighth, ninth and seventh sections (316, 318, 319, 317) follow one another in this order and where the ninth section (319) is not connected to the eighth section (318) by a section extending in the first direction.

Description

BACKGROUND OF THE INVENTION--Field of the Invention

[0001] The present disclosure relates to a coil component and a device for wireless energy transmission using the coil component. --Description of the state of the art

[0002] JP 2014-093795A discloses a wireless power transmission device equipped with a coil component whose width is greater than its height. When the coil component with such a shape is used as a power transmission coil, power transmission can be carried out efficiently even if the position of a power receiving coil is shifted in the lateral direction.

[0003] However, the coil component described in JP 2014-093795A has the problem that there is a large difference in magnetic field strength between peripheral directional positions in an opening area where the magnetic field is strongest. Publications US 2015 / 0130291A1, DE 102020104530A1, and US 2003 / 0179067A1 describe further devices with coil components for energy transmission. SHORT DESCRIPTION

[0004] The aim of the present disclosure is to provide a coil component in which a magnetic field can be formed over a wide area and the difference in magnetic field strength between the peripheral directional positions of the opening area is small.

[0005] A coil component according to one embodiment of the present disclosure comprises a substrate and a planar helical coil pattern provided on the surface of the substrate. The coil pattern exhibits a higher degree of roundness in its inner shape than in its outer shape.

[0006] According to one embodiment of the present disclosure, this enables the provision of a coil component that is capable of generating a magnetic field over a wide area and reducing the difference in magnetic field strength between peripheral directional positions of the opening area. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The aforementioned features and advantages of the present disclosure will become clearer from the following description of certain preferred embodiments in conjunction with the accompanying drawings, in which: Fig. 1 a schematic view to illustrate the configuration of a wireless power transmission device according to an embodiment of the present disclosure; Fig. 2 a schematic view to illustrate the basic configuration of a coil component 100 that can be used as an energy transmission coil 10; Fig. 3A is a schematic representation to explain a definition of the inner form ID; Fig. 3B is a schematic representation to explain a definition of the outer form OD; Fig. 4 is a schematic representation showing an example where the corner areas of the inner shape ID are slightly curved; Fig. 5 a schematic cross-sectional view to illustrate the structure of the coil component 100 according to one embodiment; Fig. 6 is a schematic top view showing the pattern shape of the first coil pattern CP1; Fig. 7 is a schematic top view showing the pattern shape of the second coil pattern CP2; Fig. 8 is a schematic top view showing a state in which the first and second coil patterns CP1 and CP2 overlap as seen from the side of surface 101A of substrate 101; Fig. 9 is a graph to illustrate the line width of the lines that form the first coil pattern CP1, and the empty space width between the lines; Fig. 10 is a schematic top view showing the pattern shape of the first coil pattern CP1 according to a first modification; Fig. 11 is a schematic top view showing the pattern shape of the second coil pattern CP2 according to the first modification; Fig. 12 is a schematic top view showing a state in which the in Fig. 10 first coil patterns CP1 and the one shown in Fig. 11 shown second coil patterns CP2 overlap; Fig. 13 is a schematic top view showing the pattern shape of the first coil pattern CP1 according to a second modification; Fig. 14 is a schematic top view showing the pattern shape of the second coil pattern CP2 according to the second modification, and Fig. 15 is a schematic top view showing a state in which the first and second coil patterns CP1 and CP2 overlap according to the second modification as seen from the side of surface 101A of substrate 101. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0008] Preferred embodiments of the present disclosure are explained in detail below with reference to the accompanying drawings.

[0009] Fig. Figure 1 is a schematic view to illustrate the configuration of a wireless power transmission device according to an embodiment of the present disclosure.

[0010] The in Fig. The wireless power transmission device shown in Figure 1 comprises a power transmission coil 10 and a power receiving coil 20, which are magnetically coupled to each other, a power transmission circuit 11 connected to the power transmission coil 10, and a power receiving circuit 21 connected to the power receiving coil 20. The power transmission circuit 11 is connected to a power supply 12, and the power receiving circuit 21 is connected to a battery 22. The power receiving coil 20, the power receiving circuit 21, and the battery 22 are integrated into a mobile device, such as a smartphone. The power transmission coil 10, the power transmission circuit 11, and the power supply 12 are integrated into a device in which a mobile device is placed, such as a center console in the interior of a car.The relative position between the energy transfer coil 10 and the energy receiving coil 20 varies depending on the position where the mobile phone is placed, so the energy transfer coil 10 must generate a magnetic field over a wide area in order to transfer energy adequately regardless of the placement position of the mobile phone.

[0011] Fig. Figure 2 is a schematic view to illustrate the basic configuration of a coil component 100 that can be used as an energy transmission coil 10.

[0012] As in Fig. As shown in Figure 2, the coil component 100 comprises a substrate 101 made of a PET layer and a planar helical coil pattern CP provided on the surface of the substrate 101. The coil pattern CP is formed by a conductor pattern wound in a plurality of turns. An inner shape ID is defined by a line segment along the inner peripheral side edge of a conductor pattern 102 located at the innermost periphery, and an outer shape OD is defined by a line segment along the outer peripheral side edge of a conductor pattern 103 located at the outermost periphery. The inner shape ID and the outer shape OD are each closed line segments.

[0013] The innermost conductor pattern 102 ends at the inner peripheral end, so that, as in Fig. As shown in Figure 3A, the inner shape ID encloses a virtual line L1. The virtual line L1 is a straight line obtained by extending a line segment L2, which runs along the inner peripheral side edge of the conductor pattern 102 from the outer periphery to an inner periphery, beyond the inner peripheral end 104 and to the conductor pattern 102 that exists at a position beyond the inner peripheral end 104. Similarly, the outermost conductor pattern 103 terminates at an outer peripheral end 105, so that, as shown in Fig. Figure 3B shows the outer shape OD enclosing a virtual line L3. The virtual line L3 is a straight line obtained by extending a line segment L4, which runs along the outer peripheral side edge of the conductor pattern 103 from the inner periphery to the outer periphery, beyond the outer peripheral end 105 and to the conductor pattern 103 that is present at a position beyond the outer peripheral end 105.

[0014] The roundness of the inner shape ID of the coil pattern CP is higher than the roundness of the outer shape OD of the coil pattern CP. The roundness is defined by 4Sπ / L. 2Assuming that the area of ​​the closed line segment (graphic) is equal to S and the peripheral length is equal to L, and that the closer the roundness is to 1, the more a target shape approximates a true circle. In the present embodiment, the inner shape ID has a high roundness, thus improving the uniformity of a magnetic field passing through an opening region 106 (region surrounded by the innermost conductor pattern 102) of the coil pattern CP in the peripheral direction. If the coil component 100 is considered as the one in Fig. By using the energy transfer coil 10 shown in Figure 1, the magnetic coupling between the energy transfer coil 10 and the energy receiving coil 20 is improved without any displacement of their relative position. To further increase the roundness of the inner shape ID, the corner regions of the inner shape ID can be slightly curved, as shown in Figure 1. Fig. 4 shown.

[0015] On the other hand, the outer shape OD in the present embodiment has a low roundness, and a magnetic field can be extended to a desired area, unlike when the outer shape OD is close to a true circle. Consequently, if the coil component 100 is considered as the one in Fig. When using the energy transfer coil 10 shown in Figure 1, magnetic coupling is achieved even with a shift in the relative position between the energy transfer coil 10 and the energy receiving coil 20. However, if the roundness of the outer shape OD is too low, the uniformity of the magnetic field distribution outside the coil pattern CP deteriorates significantly, so the roundness of the outer shape OD can be higher than the roundness (= 0.785) of a square.

[0016] The following section describes the pattern shape of the coil pattern CP in more detail.

[0017] Fig. Figure 5 is a schematic cross-sectional view to illustrate the structure of the coil component 100 according to one embodiment.

[0018] The in Fig. The coil component 100 shown in Figure 5 comprises a first coil pattern CP1, which is provided on one surface 101A of the substrate 101, and a second coil pattern CP2, which is provided on the other surface 101B of the substrate 101. If the coil component 100 is considered as shown in Figure 5, the coil component 100 is a coil pattern CP1 provided on one surface 101A of the substrate 101. Fig. The energy transfer coil 10 shown in Figure 1 can be covered on one side in the axial direction with a magnetic foil 107. In this case, the energy receiving coil 20 is arranged on the side of the energy transfer coil 10 opposite the magnetic foil 107.

[0019] Fig. Figure 6 is a schematic top view showing the pattern shape of the first coil pattern CP1.

[0020] As in Fig. As shown in Figure 6, the first coil pattern CP1 has a six-turn configuration formed by turns 110, 120, 130, 140, 150, and 160, with turn 110 located at the outermost periphery and turn 160 at the innermost periphery. Turns 110, 120, 130, 140, and 150 are each radially subdivided into four parts by three helical slots. Turn 160 is radially subdivided into two parts by a helical slot. Specifically, winding 110 is subdivided into four lines 111 to 114, winding 120 into four lines 121 to 124, winding 130 into four lines 131 to 134, winding 140 into four lines 141 to 144, winding 150 into four lines 151 to 154 and winding 160 into two lines 161 and 162.

[0021] Cables 111, 121, 131, 141, 151, and 161 are continuous cables wound in a spiral of six turns, each located at the outermost periphery in the corresponding turn. Cables 112, 122, 132, 142, 152, and 162 are continuous cables wound in a spiral of six turns, each being the second cable in the corresponding turn from the outermost peripheral cable. Cables 113, 123, 133, 143, and 153 are continuous cables wound in a spiral of five turns, each being the second cable in the corresponding turn from the innermost peripheral cable. The lines 114, 124, 134, 144 and 154 are continuous lines wound spirally in five turns, and are located at the innermost periphery in the corresponding turn.

[0022] The outer peripheral ends of conductors 111 to 114 are connected to a first terminal electrode E1. The inner peripheral ends of conductors 161, 162, 153 and 154 are each connected to through conductors 301 to 304 that penetrate the substrate 101.

[0023] The inner shape ID and the outer shape OD of the first coil pattern CP1 are each an octagon, and the interior angles of the corner regions contained in the inner and outer shapes ID and OD are all less than 180°. The outer shape OD of the first coil pattern CP1 is larger in the X direction (first direction) than in the Y direction (second direction), while the inner shape ID of the first coil pattern CP1 is essentially the same size in both the X and Y directions. Consequently, the roundness of the inner shape ID of the first coil pattern CP1 is greater than the roundness of the outer shape OD of the first coil pattern CP1.

[0024] Fig. Figure 7 is a schematic top view of the pattern shape of the second coil pattern CP2, showing a state viewed from the side of surface 101A of substrate 101 through substrate 101.

[0025] The second coil pattern CP2 has the same pattern shape as the first coil pattern CP1. However, the second coil pattern CP2 need not have the exact same shape as the first coil pattern CP1, and any size difference due to manufacturing defects or tolerances can be disregarded. The second coil pattern CP2 has a six-turn configuration, formed from turns 210, 220, 230, 240, 250, and 260, with turn 210 at the outermost periphery and turn 260 at the innermost periphery. Turns 210, 220, 230, 240, and 250 are each radially subdivided into four parts by three helical slots. Turn 260 is radially subdivided into two parts by one helical slot.Specifically, winding 210 is subdivided into four lines 211 to 214, winding 220 into four lines 221 to 224, winding 230 into four lines 231 to 234, winding 240 into four lines 241 to 244, winding 250 into four lines 251 to 254 and winding 260 into two lines 261 and 262.

[0026] Lines 211, 221, 231, 241, 251, and 261 are continuous lines wound in a spiral of six turns, each located at the outermost periphery in the corresponding turn. Lines 212, 222, 232, 242, 252, and 262 are continuous lines wound in a spiral of six turns, each being the second line in the corresponding turn from the outermost peripheral line. Lines 213, 223, 233, 243, and 253 are continuous lines wound in a spiral of five turns, each being the second line in the corresponding turn from the innermost peripheral line. The lines 214, 224, 234, 244 and 254 are continuous lines wound spirally in five turns, each located at the innermost periphery in the corresponding turn.

[0027] The outer peripheral ends of conductors 211 to 214 are connected to a second terminal electrode E2. The inner peripheral ends of conductors 261, 262, 253, and 254 are each connected to the through conductors 304, 303, 302, and 301, respectively. Thus, four conductors, each with 11 turns, are connected in parallel between the first and second terminal electrodes E1 and E2. The second terminal electrode E2 can be located on surface 101A of substrate 101. In this case, the outer peripheral ends of conductors 211 to 214, located on surface 101B of substrate 101, are connected to the second terminal electrode E2, located on surface 101A of substrate 101, via through conductors that penetrate substrate 101.

[0028] Fig. Figure 8 is a schematic top view illustrating a state in which the first and second coil patterns CP1 and CP2 overlap as seen from the side of surface 101A of substrate 101.

[0029] As in Fig. As shown in Figure 8, the planar positions of the conductors forming the first coil pattern CP1 and the conductors forming the second coil pattern CP2 are essentially the same, except for a transition region located between the first and second terminal electrodes E1, E2 and the through conductors 301 to 304. Furthermore, the first and second terminal electrodes E1 and E2 are arranged side by side in the X-direction, facilitating their connection with the Fig. The energy transmission circuit 11 shown in 1 is facilitated.

[0030] Fig. Figure 9 is a graph illustrating the line width of the lines forming the first coil pattern CP1 and the empty space width between the lines.

[0031] As described above, the first coil pattern CP1 is formed from turns 110, 120, 130, 140 and 150, each with four conductors, and turn 160 with two conductors. As in Fig. As shown in Figure 6, the virtual lines Lx and Ly, which extend from a center point 108 of the first coil pattern CP1 in the X and Y directions respectively, each intersect 22 lines. Fig. Figure 9 represents a conductor width Wx of the conductors crossing the virtual line Lx, a gap width Sx between them, and a magnetic field strength Mx on them, as well as a conductor width Wy of the conductors crossing the virtual line Ly, a gap width Sy between them, and a magnetic field strength My on them. In this diagram, the conductor number of the outermost conductor 111 is defined as "1", and the conductor number of the innermost conductor 162 is defined as "22". The gap widths Sx and Sy are each defined by the gap width between a target conductor and a conductor adjacent to the inner peripheral side of the target conductor.

[0032] As in Fig. As shown in Figure 9, for the radially arranged 22 conduits, the conduit widths Wx and Wy increase from the inner periphery to the outer periphery at both a first position where the virtual line Lx is crossed and a second position where the virtual line Ly is crossed. The increase in conduit widths Wx and Wy from the inner periphery to the outer periphery occurs stepwise. Specifically, the increase occurs in four steps at the first position where the virtual line Lx is crossed and in five steps at the second position where the virtual line Ly is crossed. That is, the number of steps in which the conduit width Wy increases at the second position is greater than the number of steps in which the conduit width Wx increases at the first position. The reason for the increase in conduit widths Wx and Wy from the inner periphery to the outer periphery is as follows: As shown in Fig. As shown in Figure 9, the magnetic field strength is highest on the innermost conductor and decreases from the innermost conductor towards the outer periphery, so it is necessary to reduce loss by decreasing the conductor width in an area with high magnetic field strength and to reduce DC resistance by increasing the conductor width in an area with low magnetic field strength.Furthermore, the reason for the number of steps in which the line width Wy increases at the second position where the virtual line Ly is crossed is as follows: the outer shape OD of the first coil pattern CP1 is larger in the X direction than in the Y direction, which means that in the same turn the magnetic field strength at the second position crossing the virtual line Ly is higher than at the first position crossing the virtual line Lx, so that it is necessary to fine-tune the ratio between a loss and a DC resistance by increasing the number of steps that increase the line width Wy.

[0033] The outer shape OD of the first coil pattern CP1 is, as described above, larger in the X direction than in the Y direction. Consequently, in each turn, the conductor width Wx at the first position crossing the first virtual line Lx is larger than the conductor width Wy at the second position crossing the second virtual line Ly. Thus, the gap width Sx at a third position crossing the first virtual line Lx can be constant in the radial direction, and the gap width Sy at a fourth position crossing the second virtual line Ly can also be constant in the radial direction. Furthermore, the gap width Sx at the third position crossing the first virtual line Lx is larger than the gap width Sy at the fourth position crossing the second virtual line Ly. This prevents the conductor width Wx at the first position crossing the virtual line Lx from increasing excessively, thus suppressing any loss at the first position.Furthermore, in each turn of the coil pattern CP1, the difference D1 between the conductor width Wx at the first position and the conductor width Wy at the second position is smaller than the difference D2 between the void width Sx at the third position adjacent to the first position and the void width Sy at the fourth position adjacent to the second position. This can prevent extreme variation in conductor width within the same turn, thereby making it possible to reduce DC resistance.

[0034] While the pattern shape of the first coil pattern CP1 has been described as follows, the second coil pattern CP2 has the same pattern shape. Thus, according to the present embodiment, the coil component 100 has the first and second coil patterns CP1 and CP2, and the inner shape ID has a higher roundness than the outer shape OD, making it possible to improve the peripheral uniformity of a magnetic field on the innermost windings 160 and 260 and to form a magnetic field over a wide area, particularly in the X direction.

[0035] The Fig. 10 and Fig. Figure 11 are schematic top views showing the pattern shape of the first and second coil pattern CP1 and CP2 respectively according to a first modification. Fig. Figure 12 is a schematic top view showing a state in which the in Fig. 10 first coil patterns CP1 and the one shown in Fig. The 11 depicted second coil patterns CP2 overlap each other.

[0036] The first and second coil patterns CP1 and CP2, according to the first modification, exhibit an essentially elliptical inner shape, with the corner regions of the inner shape ID being gently curved. This increases the roundness of the inner shape ID, further improving the peripheral uniformity of a magnetic field on the innermost winding.

[0037] Fig. Figure 13 is a schematic top view showing the pattern shape of the first coil pattern CP1 according to a second modification.

[0038] The first coil pattern CP1 according to the in Fig. The second modification shown in 13 differs from the one in Fig. The first coil pattern CP1 shown in Figure 6 is modified by radially dividing the turns 110, 120, 130, 140, and 150 into five parts by four spiral slots. Specifically, turn 110 is divided into five conductors 111 to 115, turn 120 into five conductors 121 to 125, turn 130 into five conductors 131 to 135, turn 140 into five conductors 141 to 145, turn 150 into five conductors 151 to 155, and turn 160 into two conductors 161 and 162.

[0039] Cables 111, 121, 131, 141, 151, and 161 are continuous cables wound in a spiral of six turns, each located at the outermost periphery in the corresponding turn. Cables 112, 122, 132, 142, 152, and 162 are continuous cables wound in a spiral of six turns, each being the second cable in the corresponding turn from the outermost peripheral cable. Cables 113, 123, 133, 143, and 153 are continuous cables wound in a spiral of five turns, each being the third cable in the corresponding turn from the outermost peripheral cable. Lines 114, 124, 134, 144 and 154 are continuous lines wound in a spiral of five turns, and are, counting from the innermost peripheral line, the second line in the respective turn.The cables 115, 125, 135, 145 and 155 are continuous cables wound spirally in five turns, each located at the innermost periphery in the corresponding turn.

[0040] The outer peripheral ends of conductors 111 to 115 are connected to the first terminal electrode E1. The inner peripheral ends of conductors 161, 162, 153, 154 and 155 are each connected to through conductors 301 to 305 that penetrate the substrate 101.

[0041] The outer shape OD of the first coil pattern CP1 has a first and a second section 311 and 312 extending in the X direction, a third section 313 extending in the Y direction, a fourth section 314 located between the first and second sections 311 and 312 and extending obliquely to the X direction, and a fifth section 315 located between the second and third sections 312 and 313, curved so that its direction of extension changes from the X direction to the Y direction. Specifically, there are two first sections 311, two third sections 313, four second sections 312, four fourth sections 314, and four fifth sections 315. The boundaries between the fourth section 314 and the first and second sections 311 and 312 are not rounded but angular.The interior angles of the corner regions contained in the outer form OD are less than 180° except for the corner region at the boundary between the second section 312 and the fourth section 314, and the interior angle of the corner region between the second section 312 and the fourth section 314 is greater than 180°.

[0042] On the other hand, the inner shape ID of the first coil pattern CP1 has a sixth section 316, corresponding to the first section 311 and extending in the X direction; a seventh section 317, corresponding to the third section 313 and extending in the Y direction; an eighth section 318, corresponding to the fourth section 314 and extending obliquely to the X direction; and a ninth section 319, corresponding to the fifth section 315 and curved such that its direction of extension changes from the X direction to the Y direction. The boundary between the sixth section 316 and the eighth section 318 is not rounded but angular. The inner shape ID of the first coil pattern CP1 does not have a section corresponding to the second section 312, and thus the ninth section 319 is not connected to the eighth section 318 by a section extending in the X direction.Consequently, the roundness of the inner shape ID is higher than that of the outer shape OD. The interior angles of the corner regions contained in the inner shape ID are less than 180°, with the exception of the corner region at the boundary between the eighth section 318 and the ninth section 319, and the interior angle of the corner region between the eighth section 318 and the ninth section 319 is greater than 180°.

[0043] Fig. Figure 14 is a schematic top view of the pattern shape of the second coil pattern CP2 according to the second modification, showing a state viewed from the side of surface 101A of substrate 101 through substrate 101.

[0044] The second coil pattern CP2 has the same pattern shape as the first coil pattern CP1. However, the second coil pattern CP2 need not have the exact same shape as the first coil pattern CP1, and any size difference due to manufacturing defects or tolerances can be disregarded. The second coil pattern CP2 has a six-turn configuration formed from turns 210, 220, 230, 240, 250, and 260, with turn 210 at the outermost periphery and turn 260 at the innermost periphery. Turns 210, 220, 230, 240, and 250 are each radially subdivided into five parts by four helical slots. Turn 260 is radially subdivided into two parts by a helical slot.Specifically, winding 210 is subdivided into five lines 211 to 215, winding 220 into five lines 221 to 225, winding 230 into five lines 231 to 235, winding 240 into five lines 241 to 245, winding 250 into five lines 251 to 255 and winding 260 into two lines 261 and 262.

[0045] Lines 211, 221, 231, 241, 251, and 261 are continuous lines wound in a spiral of six turns, each located at the outermost periphery in the corresponding turn. Lines 212, 222, 232, 242, 252, and 262 are continuous lines wound in a spiral of six turns, each being the second line in the corresponding turn from the outermost peripheral line. Lines 213, 223, 233, 243, and 253 are continuous lines wound in a spiral of five turns, each being the third line in the corresponding turn from the outermost peripheral line. Lines 214, 224, 234, 244 and 254 are continuous lines wound in a spiral pattern with five turns, and are, counting from the innermost peripheral line, the second line in the respective turn.The lines 215, 225, 235, 245 and 255 are continuous lines wound spirally in five turns, each located at the innermost periphery in the corresponding turn.

[0046] The outer peripheral ends of leads 211 to 215 are connected to the second terminal electrode E2. The inner peripheral ends of leads 261, 262, 253, 254, and 255 are each connected to the through conductors 305, 304, 303, 302, and 301, respectively. Thus, four leads with 11 turns each and one lead with 10 turns are connected in parallel between the first and second terminal electrodes E1 and E2. The second terminal electrode E2 can be placed on the surface 101A of the substrate 101. In this case, the outer peripheral ends of the conductors 211 to 215, which are provided on the surface 101B of the substrate 101, are connected to the second terminal electrode E2, which is attached to the surface 101A of the substrate 101, via through conductors that penetrate the substrate 101.

[0047] Fig. Figure 15 is a schematic top view showing a state in which the first and second coil patterns CP1 and CP2 overlap according to the second modification as seen from the side of surface 101A of substrate 101.

[0048] As in Fig. As shown in Figure 15, in the second modification the planar positions of the conductors forming the first coil pattern CP1 and the conductors forming the second coil pattern CP2 are essentially the same, with the exception of a transition area located between the first and second terminal electrodes E1, E2 and the through conductors 301 to 304. Furthermore, the first and second terminal electrodes E1 and E2 are arranged side by side in the X-direction, facilitating their connection with the Fig. The energy transmission circuit 11 shown in 1 is facilitated.

[0049] As illustrated in the second modification, the inner shape ID and the outer shape OD of the coil pattern can differ significantly in form. In the second modification, the outer shape OD of the first coil pattern CP1 has bent sections where the leads are bent at the boundary between the first and fourth sections 311 and 314, at the boundary between the fourth and second sections 314 and 312, at the boundary between the second and fifth sections 312 and 315, and at the boundary between the fifth and third sections 315 and 313. The inner shape ID of the coil pattern CP1 has bent sections where the leads are bent at the boundary between the sixth and eighth sections 316 and 318, at the boundary between the eighth and ninth sections 318 and 319, and at the boundary between the ninth and seventh sections 319 and 317.This means that in the second modification, the inner shape ID of the first coil pattern CP1 has fewer bent points than the outer shape OD of the first coil pattern CP1. As a result, the inner shape ID has a more rounded shape than the outer shape OD and thus exhibits a higher degree of roundness.

[0050] A coil component according to the present disclosure comprises a substrate and a planar helical coil pattern provided on the surface of the substrate. The coil pattern exhibits a higher degree of roundness in its inner shape than in its outer shape. This makes it possible to provide a coil component capable of generating a magnetic field over a wide area and reducing the difference in magnetic field strength between peripheral directional positions of the opening area.

[0051] The roundness of the outer shape of the coil pattern can be greater than that of a square. This makes it possible to achieve a uniform magnetic field distribution outside the coil pattern.

[0052] The outer shape of the coil pattern can have a first and a second section extending in a first direction, a third section extending in a second direction perpendicular to the first direction, a fourth section positioned between the first and second sections and extending obliquely to the first direction, and a fifth section positioned between the second and third sections and curved in such a way that its direction of extension changes from the first direction to the second direction.The inner shape of the coil pattern can have a sixth section corresponding to the first section and extending in the first direction, a seventh section corresponding to the third section and extending in the second direction, an eighth section corresponding to the fourth section and extending obliquely to the first direction, and a ninth section corresponding to the fifth section and curved so that its direction of extension changes from the first direction to the second direction. The ninth section cannot be connected to the eighth section by a section extending in the first direction. This makes it possible to further increase the roundness of the inner shape.

[0053] The conductor width of the coil pattern can increase from the inner periphery to the outer periphery. This makes it possible to reduce losses on the inner peripheral side, where the magnetic field strength is high, and DC resistance on the outer peripheral side, where the magnetic field strength is low.

[0054] The outer shape of the coil pattern can be larger in the first direction than in the second direction, which is perpendicular to the first direction, and the conductor width in each turn of the coil pattern can be larger at a first position, which intersects a first virtual line extending in the first direction and passing through the center of the coil pattern, than at a second position, which intersects a second virtual line extending in the second direction and passing through the center of the coil pattern. This makes it possible to reduce DC resistance.

[0055] The conductor width of the coil pattern can increase stepwise by a multiple of times from the inner periphery to the outer periphery at the first position, and can increase stepwise by a greater number of times from the inner periphery to the outer periphery at the second position than at the first position. Thus, it is possible to fine-tune the ratio between loss and DC resistance at the second position, which has a higher magnetic field strength than the first position.

[0056] The gap width between the lines forming the coil pattern can be larger at a third position, which crosses the first virtual line, than at a fourth position, which crosses the second virtual line. This makes it possible to reduce losses at the first position.

[0057] In each turn of the coil pattern, the difference between the conductor width at the first position and the conductor width at the second position can be smaller than the difference between the void width at the third position and the void width at the fourth position. This prevents extreme variation in conductor width within the same turn and thus reduces the DC resistance.

[0058] A device for wireless power transmission according to the present disclosure comprises the coil component described above and a power transmission circuit connected to the coil component. Thus, magnetic coupling can be achieved even if there is a shift in the relative position between the coil component used as the power transmission coil and a power receiving coil. Furthermore, the magnetic coupling between the coil component used as the power transmission coil and the power receiving coil can be improved even if there is no shift in the relative position between them.

Claims

[1] A coil component (100), comprising: a substrate (101) and a planar spiral coil pattern (CP1, CP2) arranged on a surface of the substrate (101), wherein the coil pattern (CP1, CP2) has a higher roundness in its inner shape (ID) than in its outer shape (OD), wherein the outer shape (OD) of the coil pattern (CP1, CP2) has a first and a second section (311, 312) extending in a first direction, a third section (313) extending in a second direction perpendicular to the first direction, a fourth section (314) arranged between the first and the second section (311, 312) extending straight and obliquely to the first direction, and a fifth section (315) arranged between the second and the third section (312, 313) being curved such that its direction of extension changes from the first direction to the second direction, where the first, fourth, second, fifth and third sections (311, 314, 312, 315, 313) follow one another in this order, wherein the inner shape (ID) of the coil pattern (CP1, CP2) has a sixth section (316) corresponding to the first section (311) and extending in the first direction, a seventh section (317) corresponding to the third section (313) and extending in the second direction (312), an eighth section (318) corresponding to the fourth section (314) and extending straight and obliquely to the first direction, and a ninth section (319) corresponding to the fifth section (315) and curved such that its direction of extension changes from the first direction to the second direction, where the sixth, eighth, ninth and seventh sections (316, 318, 319, 317) follow one another in this order and where the ninth section (319) is not connected to the eighth section (318) by a section extending in the first direction. [2] The coil component (100) as claimed in claim 1, wherein the roundness of the outer shape (OD) of the coil pattern (CP1, CP2) is higher than the roundness of a square. [3] The coil component (100) as claimed in claim 1 or 2, wherein a conductor width of the coil pattern (CP1, CP2) increases from an inner periphery to an outer periphery. [4] The coil component (100) as claimed in claim 3, wherein the outer shape (OD) of the coil pattern (CP1, CP2) is larger in a first direction than in a second direction perpendicular to the first direction, and wherein the conductor width in each turn (110-150, 210-250) of the coil pattern (CP1, CP2) at a first position which crosses a first virtual line extending in the first direction and passing through a midpoint (108) of the coil pattern (CP1, CP2) is larger than at a second position which crosses a second virtual line extending in the second direction and passing through the midpoint (108) of the coil pattern (CP1, CP2). [5] The coil component (100) as claimed in claim 4, wherein the conductor width of the coil pattern (CP1, CP2) at the first position increases stepwise a multiple times from the inner periphery to the outer periphery and wherein the conduction width of the coil pattern (CP1, CP2) at the second position increases stepwise from the inner periphery to the outer periphery a number of times greater than the number of times of increase at the first position. [6] The coil component (100) as claimed in claim 4 or 5, wherein a void width between the conductors forming the coil pattern (CP1, CP2) at a third position crossing the first virtual line is larger than at a fourth position crossing the second virtual line. [7] The coil component (100) as claimed in claim 6, wherein in each turn (110-150, 210-250) of the coil pattern (CP1, CP2) the difference between the conductor width at the first position and the conductor width at the second position is smaller than the difference between the void width at the third position and the void width at the fourth position. [8] A coil component (100), comprising: a substrate (101) and a planar spiral coil pattern (CP1, CP2) arranged on a surface of the substrate (101), wherein the coil pattern (CP1, CP2) has a higher roundness in its inner shape (ID) than in its outer shape (OD), where the conductor width of the coil pattern (CP1, CP2) increases from an inner periphery to an outer periphery, wherein the outer shape (OD) of the coil pattern (CP1, CP2) is larger in a first direction than in a second direction, which is perpendicular to the first direction, wherein the conductor width in each turn (110-150, 210-250) of the coil pattern (CP1, CP2) is larger at a first position that crosses a first virtual line extending in the first direction and passing through a midpoint (108) of the coil pattern (CP1, CP2) than at a second position that crosses a second virtual line extending in the second direction and passing through the midpoint (108) of the coil pattern (CP1, CP2), wherein the conductor width of the coil pattern (CP1, CP2) at the first position increases stepwise a multiple times from the inner periphery to the outer periphery and wherein the conduction width of the coil pattern (CP1, CP2) at the second position increases stepwise from the inner periphery to the outer periphery a number of times greater than the number of times of increase at the first position. [9] The coil component (100) as claimed in claim 8, wherein at least one outermost step in each of the first and second positions has a plurality of conductors. [10] A device for wireless power transmission, comprising: the coil component (100) according to one of claims 1 to 9 and a power transmission circuit (11) connected to the coil component (100).

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