Coil components

Abstract

This invention provides a coil component that achieves high power transmission efficiency when used in a wireless power transmission device. The outer width Wx2out of the coil pattern (100) is larger than the outer width Wy2out, and the inner width Wx2in is larger than the inner width Wy2in. The outer dimensions of the coil pattern (100) are Wy2out > Wy1out, and Wy2in > Wy1in. The inner ratio Rin defined by Wy2in / Wy1in is Wy2out > Wy1out. This is larger than the outer ratio Rout defined by Wy2out / Wy1out. Based on this shape, when used in a wireless power transmission device, high power transmission efficiency can be achieved even when the central axis of the transmitting coil and the central axis of the receiving coil are offset in the x-direction, and the reduction in power transmission efficiency when the central axes of the transmitting coil and the receiving coil are aligned is suppressed.

Description

Technical Field

[0001] The present invention relates to a coil component, and in particular to a coil component that can be used in a wireless power transmission device. Background Art

[0002] As a coil component that can be used in a wireless power transmission device, there is known a coil component described in Patent Document 1. The coil component described in Patent Document 1 has a horizontally long power transmission coil so that power can be transmitted even when the relative positions of the power transmission coil and the power reception coil are offset in the horizontal direction.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-93795 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] However, the coil component described in Patent Document 1 has a problem in that the power transmission efficiency is reduced when the relative positions of the power transmission coil and the power reception coil are not offset, that is, when the central axes of the power transmission coil and the power reception coil coincide with each other.

[0008] Therefore, an object of the present invention is to provide a coil component which, when used in a wireless power transmission device, can achieve high power transmission efficiency even when the central axis of the power transmission coil coincides with the central axis of the power reception coil.

[0009] Technical means for solving technical problems

[0010] The coil component of the present invention is characterized in that it comprises: a substrate; and a spiral first coil pattern arranged on a surface of the substrate, the outer shape and inner shape of the first coil pattern are both larger in width in a first direction than in a second direction orthogonal to the first direction, the outer shape of the first coil pattern comprises: a pair of first outer shape intervals, whose width in the second direction is the first outer shape width; and a second outer shape interval, which is located between the pair of first outer shape intervals in the first direction, and whose width in the second direction is the second outer shape width larger than the first outer shape width, the inner shape of the first coil pattern comprises: a pair of first inner shape intervals, whose width in the second direction is the first inner shape width; and a second inner shape interval, which is located between the pair of first inner shape intervals in the first direction, and whose width in the second direction is the second inner shape width larger than the first inner shape width, the inner shape ratio which is the ratio of the second inner shape width to the first inner shape width is greater than the outer shape ratio which is the ratio of the second outer shape width to the first outer shape width.

[0011] According to the present invention, since the outer shape and inner shape of the first coil pattern are expanded in the first direction, when used in a wireless power transmission device, even when the central axis of the power transmission coil and the central axis of the power receiving coil are offset in the first direction, high power transmission efficiency can be obtained. In addition, since the width of the outer shape and inner shape of the first coil pattern in the second direction is expanded in the substantially central portion in the first direction, and the inner shape ratio is greater than the outer shape ratio, it is possible to suppress the reduction in power transmission efficiency when the central axis of the power transmission coil and the central axis of the power receiving coil are aligned.

[0012] In the present invention, the ratio of the inner aspect ratio to the outer aspect ratio may be equal to or greater than 1.2. This can more effectively suppress a decrease in power transmission efficiency when the central axis of the power transmission coil coincides with the central axis of the power reception coil.

[0013] In the present invention, the inner width of the coil pattern in the first direction may be greater than the second inner width. Thus, even when the central axes of the power transmission coil and the power reception coil are greatly offset in the first direction, high power transmission efficiency can be achieved.

[0014] In the present invention, each of the plurality of turns constituting the first coil pattern may include: first and second winding regions, whose extension direction from the outer peripheral end to the inner peripheral end changes by 180°; a third winding region, whose extension direction is consistent with the first direction; a fourth winding region, whose extension direction has a predetermined slope relative to the first direction, and straightly connects one end of the first winding region with one end of the third winding region; and a fifth winding region, whose extension direction has a predetermined slope relative to the first direction, and straightly connects one end of the second winding region with the other end of the third winding region. Thus, the change in power transmission efficiency corresponding to the offset between the central axis of the power transmission coil and the central axis of the power receiving coil can be suppressed to a small value.

[0015] In the present invention, in each of the plurality of turns, the length of each of the fourth and fifth winding regions may be shorter than the length of the third winding region. This can suppress an increase in the overall size and expand the internal shape.

[0016] In the present invention, each of the plurality of turns may be divided into a plurality of lines in the radial direction by a spiral slit. Thereby, the density distribution of the current flowing in the first coil pattern is made uniform, and the DC resistance or AC resistance can be reduced.

[0017] The coil component of the present invention may also be provided with a spiral second coil pattern provided on another surface of the substrate, each of the plurality of turns constituting the second coil pattern is divided into a plurality of wires in the radial direction by a spiral slit, the innermost circumference turn constituting the first coil pattern includes a first wire and a second wire located on the outer peripheral side compared to the first wire, the innermost circumference turn constituting the second coil pattern includes a third wire and a fourth wire located on the outer peripheral side compared to the third wire, the inner peripheral end of the first wire and the inner peripheral end of the fourth wire are connected to each other via a first connecting portion provided through the substrate, and the inner peripheral end of the second wire and the inner peripheral end of the third wire are connected to each other via a second connecting portion provided through the substrate. Thus, the inner and outer peripheral difference of the first coil pattern and the inner and outer peripheral difference of the second coil pattern cancel each other out, thereby further reducing the DC resistance or AC resistance.

[0018] Effects of the Invention

[0019] As described above, when the coil component of the present invention is used in a wireless power transmission device, even when the central axis of the power transmission coil coincides with the central axis of the power reception coil, high power transmission efficiency can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic cross-sectional view showing the structure of a coil component 1 according to one embodiment of the present invention.

[0021] Figure 2 It is a plan view for explaining the pattern shape of the first coil pattern 100 , and shows a state viewed from the side of one surface 11 of the substrate 10 .

[0022] Figure 3 It is a plan view for explaining the pattern shape of the second coil pattern 200 , and shows a state viewed from the side of one surface 11 of the substrate 10 .

[0023] Figure 4 It is the equivalent circuit diagram of the coil component.

[0024] Figure 5 It is a schematic plan view for explaining the outer shape and inner shape of the first coil pattern 100 .

[0025] Figure 6 It is a schematic plan view for explaining the shape of the winding regions 191 to 198 .

[0026] Figure 7 This is a schematic plan view for explaining the positional relationship between the central axis of the power transmission coil and the central axis of the power reception coil when the coil component 1 is used as a power transmission coil of a wireless power transmission device.

[0027] Figure 8It is a schematic plan view showing an example in which a coil component 1 a of a comparative example is used as a power transmission coil of a wireless power transmission device instead of the coil component 1 .

[0028] Fig. 9 It is a graph comparing the power transmission efficiency of the coil component 1 according to the embodiment and the coil component 1 a according to the comparative example, and shows the relationship between the offset amount of the power receiving coil 3 and the degree of magnetic coupling.

[0029] Fig.10 This is a table showing the measurement results of Examples.

[0030] Explanation of symbols:

[0031] 1.1a Coil components

[0032] 2 Portable electronic devices

[0033] 3 Receiving coil

[0034] 4 Frame

[0035] 10 substrates

[0036] 11 One surface of the substrate

[0037] 12 The other surface of the substrate

[0038] 20 Magnetic Sheets

[0039] 100 first coil pattern

[0040] 200 second coil pattern

[0041] 110, 120, 130, 140, 150, 160, 210, 220, 230, 240, 250, 260 turns

[0042] Lines 111-114, 121-124, 131-134, 141-144, 151-154, 161, 162, 211-214, 221-224, 231-234, 241-244, 251-254, 261, 262

[0043] 171~178 appearance range

[0044] 181~188 inner shape interval

[0045] 191~198 Winding area

[0046] 301~304 connection part

[0047] A1~A4、B1~B4 line group

[0048] C1, C2 center point

[0049] E1, E2 terminal electrodes

[0050] L1, L2 imaginary lines

[0051] P1, P2 pattern width DETAILED DESCRIPTION

[0052] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0053] Figure 1 It is a schematic cross-sectional view showing the structure of a coil component 1 according to one embodiment of the present invention.

[0054] like Figure 1 As shown, the coil component 1 of this embodiment includes a substrate 10, a first coil pattern 100 formed on one surface 11 of the substrate 10, and a second coil pattern 200 formed on the other surface 12 of the substrate 10. The details will be described later. The inner peripheral end of the first coil pattern 100 and the inner peripheral end of the second coil pattern 200 are connected via a plurality of connecting portions (in Figure 1 In addition, when the coil component 1 of the present embodiment is used as a power transmission coil of a wireless power transmission device, the power receiving coil is arranged in a manner opposite to one surface 11 of the substrate 10. In this case, it is preferred to arrange a magnetic sheet 20 composed of a magnetic body such as ferrite on the other surface 12 side of the substrate 10.

[0055] The material of the substrate 10 is not particularly limited, and a transparent or translucent flexible insulating material such as PET resin can be used. Alternatively, the substrate 10 may be a flexible substrate in which epoxy resin is impregnated in glass cloth.

[0056] Figure 2 It is a plan view for explaining the pattern shape of the first coil pattern 100 , and shows a state viewed from the side of one surface 11 of the substrate 10 .

[0057] The first coil pattern 100 is a 6-turn structure consisting of turns 110, 120, 130, 140, 150, and 160, with turn 110 located at the outermost circumference and turn 160 located at the innermost circumference. Among them, turns 110, 120, 130, 140, and 150 are divided into four wires in the radial direction by three spiral slits. On the other hand, turn 160 is divided into two wires in the radial direction by one spiral slit. As a result, turn 110 is divided into four wires 111 to 114, turn 120 is divided into four wires 121 to 124, turn 130 is divided into four wires 131 to 134, turn 140 is divided into four wires 141 to 144, turn 150 is divided into four wires 151 to 154, and turn 160 is divided into two wires 161 and 162.

[0058] The wires 111, 121, 131, 141, 151, and 161 are continuous wires wound in a spiral shape for 6 turns and are located at the outermost circumference in each turn. The wires 112, 122, 132, 142, 152, and 162 are continuous wires wound in a spiral shape for 6 turns and are located at the second outer circumference in each turn. The wires 113, 123, 133, 143, and 153 are continuous wires wound in a spiral shape for 5 turns and are located at the second inner circumference in each turn. The wires 114, 124, 134, 144, and 154 are continuous wires wound in a spiral shape for 5 turns and are located at the innermost circumference in each turn.

[0059] Although not particularly limited, in this embodiment, the pattern width P2 of the lines 131 to 134, 141 to 144, 151 to 154, 161, and 162 is narrower than the pattern width P1 of the lines 111 to 114, 121 to 124. Here, the “pattern width” refers to the width of the planar conductor in the radial direction.

[0060] The outer ends of the first coil pattern 100 are formed by the outer ends of the wires 111 to 114, which are commonly connected to the terminal electrode E1. On the other hand, the inner ends of the first coil pattern 100 are formed by the inner ends of the wires 161, 162, 153, and 154, which are respectively connected to the connecting portions 301 to 304.

[0061] like Figure 2 As shown, when an imaginary line L1 extending radially is drawn from the center point C1 of the first coil pattern 100, the connection portion 301 and the connection portion 304 are arranged at positions symmetrical to each other with respect to the imaginary line L1, and the connection portion 302 and the connection portion 303 are arranged at positions symmetrical to each other with respect to the imaginary line L1.

[0062] Figure 3 It is a plan view for explaining the pattern shape of the second coil pattern 200 , and shows a state viewed from one surface 11 side of the substrate 10 , that is, a state viewed through the substrate 10 .

[0063] like Figure 3 As shown, the pattern shape of the second coil pattern 200 is the same as the pattern shape of the first coil pattern 100. Therefore, the first coil pattern 100 and the second coil pattern 200 can be manufactured using the same mask, thereby significantly reducing the manufacturing cost.

[0064] The second coil pattern 200 is a 6-turn structure consisting of turns 210, 220, 230, 240, 250, and 260, with turn 210 located at the outermost circumference and turn 260 located at the innermost circumference. Among them, turns 210, 220, 230, 240, and 250 are divided into four wires in the radial direction by three spiral slits. On the other hand, turn 260 is divided into two wires in the radial direction by one spiral slit. As a result, turn 210 is divided into four wires 211 to 214, turn 220 is divided into four wires 221 to 224, turn 230 is divided into four wires 231 to 234, turn 240 is divided into four wires 241 to 244, turn 250 is divided into four wires 251 to 254, and turn 260 is divided into two wires 261 and 262.

[0065] Wires 211, 221, 231, 241, 251, 261 are continuous wires wound in a spiral shape for 6 turns and are located at the outermost circumference in each turn. Wires 212, 222, 232, 242, 252, 262 are continuous wires wound in a spiral shape for 6 turns and are located at the second outer circumference in each turn. Wires 213, 223, 233, 243, 253 are continuous wires wound in a spiral shape for 5 turns and are located at the second inner circumference in each turn. Wires 214, 224, 234, 244, 254 are continuous wires wound in a spiral shape for 5 turns and are located at the innermost circumference in each turn.

[0066] Although not particularly limited, in the present embodiment, the pattern width P2 of the lines 231 to 234 , 241 to 244 , 251 to 254 , 261 , and 262 is narrower than the pattern width P1 of the lines 211 to 214 and 221 to 224 .

[0067] The outer peripheral end of the second coil pattern 200 is composed of the outer peripheral ends of the wires 211 to 214, which are commonly connected to the terminal electrode E2. On the other hand, the inner peripheral end of the second coil pattern 200 is composed of the inner peripheral ends of the wires 261, 262, 253, and 254, which are respectively connected to the connecting parts 304, 303, 302, and 301.

[0068] like Figure 3 As shown, when an imaginary line L2 extending radially is drawn from the center point C2 of the second coil pattern 200, the connection portion 301 and the connection portion 304 are arranged at positions symmetrical to each other with respect to the imaginary line L2, and the connection portion 302 and the connection portion 303 are arranged at positions symmetrical to each other with respect to the imaginary line L2.

[0069] The first and second coil patterns 100 and 200 having such a structure are formed on the front and back surfaces of the substrate 10 so that the center points C1 and C2 overlap and the imaginary lines L1 and L2 overlap.

[0070] Figure 4: is an equivalent circuit diagram of the coil component 1 according to the present embodiment.

[0071] like Figure 4 As shown, the wire group A1 of 6 turns consisting of wires 111, 121, 131, 141, 151, 161 and the wire group B4 of 5 turns consisting of wires 214, 224, 234, 244, 254 are connected in series via a connection portion 301, forming a continuous wire wound with a total of 11 turns. The wire group A2 of 6 turns consisting of wires 112, 122, 132, 142, 152, 162 and the wire group B3 of 5 turns consisting of wires 213, 223, 233, 243, 253 are connected in series via a connection portion 302, forming a continuous wire wound with a total of 11 turns. The wire group A3 of 5 turns consisting of wires 113, 123, 133, 143, 153 and the wire group B2 of 6 turns consisting of wires 212, 222, 232, 242, 252, 262 are connected in series via the connection portion 303, forming a continuous wire wound with a total of 11 turns. The wire group A4 of 5 turns consisting of wires 114, 124, 134, 144, 154 and the wire group B1 of 6 turns consisting of wires 211, 221, 231, 241, 251, 261 are connected in series via the connection portion 304, forming a continuous wire wound with a total of 11 turns.

[0072] Thus, four wires with 11 turns are connected in parallel between the terminal electrode E1 and the terminal electrode E2. Thus, the density distribution of the current flowing in the first and second coil patterns 100 and 200 is uniformized, thereby reducing the DC resistance or AC resistance. Moreover, in the present embodiment, the wire group A1 located on the outermost circumference is connected to the wire group B4 located on the innermost circumference, the wire group A2 located on the second outer circumference is connected to the wire group B3 located on the second inner circumference, the wire group A3 located on the second inner circumference is connected to the wire group B2 located on the second outer circumference, and the wire group A4 located on the innermost circumference is connected to the wire group B1 located on the outermost circumference. Thus, the inner and outer circumference difference of the first coil pattern 100 and the inner and outer circumference difference of the second coil pattern 200 cancel each other, thereby further reducing the DC resistance or AC resistance. Moreover, since the wire groups A1, A2, B1, and B2 are set to a 6-turn structure and the wire groups A3, A4, B3, and B4 are set to a 5-turn structure, regardless of whether the pattern shapes of the first and second coil patterns 100 and 200 formed on the front and back sides of the substrate 10 are the same, the total number of turns can always be set to an odd number.

[0073] Figure 51 is a schematic top view for explaining the outer shape and inner shape of the first coil pattern 100. Here, the "outer shape" refers to the shape along the outer peripheral edge of the line 111 located at the outermost periphery, and the "inner shape" refers to the shape along the inner peripheral edge of the line 162 located at the innermost periphery. As described above, since the shapes of the first coil pattern 100 and the second coil pattern 200 are the same, the shape of the first coil pattern 100 described below is also applicable to the shape of the second coil pattern 200.

[0074] like Figure 5 As shown, the outer shape of the first coil pattern 100 includes outer shape sections 171 to 178, and the inner shape of the first coil pattern 100 includes inner shape sections 181 to 188. The areas sandwiched by the outer shape sections 171 to 178 and the inner shape sections 181 to 188 are winding areas 191 to 198 where the first coil pattern 100 is wound.

[0075] Among them, the winding regions 191 and 192 are regions where the extension direction of each line from the outer peripheral end to the inner peripheral end (or from the inner peripheral end to the outer peripheral end) changes by 180°. For example, in the winding region 191, as indicated by the symbol D1, the extension direction of the line extending in the +x direction changes by 90° and extends in the -y direction, and then the extension direction changes by 90° and extends in the -x direction. Similarly, in the winding region 192, as indicated by the symbol D2, the extension direction of the line extending in the -x direction changes by 90° and extends in the +y direction, and then the extension direction changes by 90° and extends in the +x direction.

[0076] As indicated by symbol D3, the winding region 193 is a region where each line extends linearly along the -x direction. The winding region 194 is located between the winding region 191 and the winding region 193, and is a region connecting one end of the line located in the winding region 191 and one end of the line located in the winding region 193. In the winding region 194, as indicated by symbol D4, each line extends linearly with respect to the -x direction at a prescribed slope (for example, with a slope of about 45° inclined to the -y direction). The winding region 195 is located between the winding region 192 and the winding region 193, and is a region connecting one end of the line located in the winding region 192 and the other end of the line located in the winding region 193. In the winding region 195, as indicated by symbol D5, each line extends linearly with respect to the -x direction at a prescribed slope (for example, with a slope of about 45° inclined to the +y direction).

[0077] As indicated by symbol D6, winding region 196 is a region where each line extends straightly at a predetermined inclination relative to the +x direction (for example, at a slope of about 30° in the -y direction). Winding region 196 is a transition region as a boundary between each turn, and each turn is inclined at intervals of 1 turn in the -y direction. Winding region 197 is located between winding region 191 and winding region 196, and is a region connecting the other end of the line located in winding region 191 and one end of the line located in winding region 196. In winding region 197, as indicated by symbol D7, each line extends straightly at a predetermined inclination relative to the +x direction (for example, at a slope of about 45° in the -y direction). Winding region 198 is located between winding region 192 and winding region 196, and is a region connecting the other end of the line located in winding region 192 and the other end of the line located in winding region 196. In the winding region 198 , as indicated by reference symbol D8 , each line extends linearly at a predetermined slope (eg, a slope of about 45° in the +y direction) with respect to the +x direction.

[0078] Figure 6 It is a schematic plan view for explaining the shape of the winding regions 191 to 198 .

[0079] like Figure 6 As shown, when the outer width of the winding regions 191 to 198 in the x direction is set to Wx2out and the outer width of the winding regions 191 to 198 in the y direction is set to Wy2out, the coil component of this embodiment satisfies:

[0080] Wx2out>Wy2out.

[0081] That is, the outer shape of the coil component 1 has a horizontally long shape with a larger outer shape in the x direction than in the y direction. Here, the outer shape width Wx2out is defined by the distance in the x direction between the outer shape interval 171 and the outer shape interval 172. In addition, the outer shape width Wy2out is defined by the distance in the y direction between the outer shape interval 173 and the outer shape interval 176.

[0082] Furthermore, when the inner width of the winding regions 191 to 198 in the x direction is Wx2in and the inner width of the winding regions 191 to 198 in the y direction is Wy2in, the coil component of the present embodiment satisfies:

[0083] Wx2in>Wy2in.

[0084] That is, the inner shape of the coil component 1 has a horizontally long shape in which the inner shape in the x direction is larger than the inner shape in the y direction. Here, the inner shape width Wx2in is defined by the distance in the x direction between the inner shape interval 181 and the inner shape interval 182. In addition, the inner shape width Wy2in is defined by the distance in the y direction between the inner shape interval 183 and the inner shape interval 186.

[0085] Furthermore, the coil component of the present embodiment has a shape in which a part of the winding area is deformed in a manner that bulges in the +y direction or the -y direction. Specifically, the winding area 193 is deformed in the -y direction relative to the winding areas 191 and 192, and the winding area 196 is deformed in the +y direction relative to the winding areas 191 and 192. Between the winding areas 191 and 192 and the winding area 193, winding areas 194 and 195 whose deformation amount changes linearly from the outer peripheral end to the inner peripheral end (or from the inner peripheral end to the outer peripheral end) are arranged. Similarly, between the winding areas 191 and 192 and the winding area 196, winding areas 197 and 198 whose deformation amount changes linearly from the outer peripheral end to the inner peripheral end (or from the inner peripheral end to the outer peripheral end) are arranged.

[0086] As described above, the winding regions 193 to 195 have a shape deformed in a manner of bulging in the -y direction, and the winding regions 196 to 198 have a shape deformed in a manner of bulging in the +y direction. In contrast, the winding regions 191 and 192 do not have a shape deformed in the +y direction or the -y direction. Therefore, when the outer width of the winding regions 191 and 192 in the y direction is set to Wy1out, the following is satisfied:

[0087] Wy2out>Wy1out.

[0088] Here, the outer shape width Wy1out is defined by the width of the outer shape sections 171 and 172 in the y direction.

[0089] Similarly, when the inner width of the winding regions 191 and 192 in the y direction is set to Wy1in, the following is satisfied:

[0090] Wy2in>Wy1in.

[0091] Here, the inner width Wy1in is defined by the width in the y direction of the inner shape sections 181 and 182. Furthermore, the outer width in the x direction of the outer shape sections 173 to 175 (or outer shape sections 176 to 178) is Wx1out, and the inner width in the x direction of the inner shape sections 183 to 185 (or inner shape sections 186 to 188) is Wx1in.

[0092] Here, when the ratio of the outer width Wy2out to the outer width Wy1out is defined as the outer ratio Rout (= Wy2out / Wy1out), and the ratio of the inner width Wy2in to the inner width Wy1in is defined as the inner ratio Rin (= Wy2in / Wy1in), the following conditions are satisfied:

[0093] Rin>Rout.

[0094] That is, the ratio of the inner shape of the coil component 1 to bulge in the y direction is greater than the ratio of the outer shape of the coil component 1 to bulge in the y direction. Thus, since the increase of the outer shape width Wy2out is suppressed and the inner shape width Wy2in is sufficiently increased, the increase of the overall size of the coil component 1 can be suppressed and the inner shape can be expanded.

[0095] Figure 7 This is a schematic plan view for explaining the positional relationship between the central axis of the power transmission coil and the central axis of the power reception coil when the coil component 1 of the present embodiment is used as a power transmission coil of a wireless power transmission device.

[0096] exist Figure 7 In the example shown, the coil component 1 is embedded in the center portion of the frame 4 in the x direction. When the portable electronic device 2 is placed in the placement area surrounded by the frame 4, the portable electronic device 2 is charged wirelessly. Such wireless power transmission is performed via the coil component 1 of this embodiment and the power receiving coil 3 built into the portable electronic device 2.

[0097] The inner dimension of the frame 4 in the y direction is designed to be substantially the same as or slightly larger than the outer dimension of the portable electronic device 2 in the y direction. Therefore, when the portable electronic device 2 is placed on the frame 4, the position of the portable electronic device 2 in the y direction relative to the frame 4 is not greatly offset and is positioned at the center. In contrast, the inner dimension of the frame 4 in the x direction is designed to be much larger than the outer dimension of the portable electronic device 2 in the x direction. Therefore, when the portable electronic device 2 is placed on the frame 4, the position of the portable electronic device 2 in the x direction relative to the frame 4 is greatly different depending on the placement position.

[0098] Here, if Figure 7 As shown in (a), when the portable electronic device 2 is placed in the approximate center of the x direction, since the central axis of the coil component 1 serving as the power transmitting coil is approximately consistent with the central axis of the power receiving coil 3, the magnetic flux generated by the coil component 1 interlinks with the power receiving coil 3, thereby transmitting power wirelessly.

[0099] On the other hand, Figure 7As shown in (b), when the portable electronic device 2 is placed offset in the +x direction (right direction), or as Figure 7 As shown in (c), when the portable electronic device 2 is placed offset in the -x direction (left direction), the center axis of the coil component 1 as the power transmission coil is offset from the center axis of the power receiving coil 3. However, since the outer width Wx2out of the coil component 1 of this embodiment is larger than the outer width Wy2out, and the inner width Wx2in is larger than the inner width Wy2in, even if the center axis of the coil component 1 and the center axis of the power receiving coil 3 are offset in the x direction, the magnetic flux generated from the coil component 1 can be linked to the power receiving coil 3. Therefore, even if the portable electronic device 2 is placed in any area of ​​the frame 4, wireless power transmission can be performed correctly.

[0100] Here, as a comparative example Figure 8 As shown, when a coil component 1a is used in which a portion of the winding area is deformed in a manner that does not bulge in the +y direction and the -y direction, that is, a coil component 1a having a shape in which the outer shape and the inner shape are simply expanded in the x direction, the power transmission efficiency is sometimes reduced when the central axis of the coil component 1a is roughly consistent with the central axis of the power receiving coil 3.

[0101] Fig. 9 : is a graph comparing the power transmission efficiency of the coil component 1 of the present embodiment and the coil component 1a of the comparative example, and shows the relationship between the offset amount of the power receiving coil 3 and the degree of magnetic coupling. Fig. 9 The characteristics indicated by the solid line in FIG. 1 represent the characteristics of the coil component 1 of this embodiment. Fig. 9 The characteristics indicated by the dotted line in FIG. 1 represent the characteristics of the coil component 1 a of the comparative example.

[0102] like Fig. 9 As shown, in the coil component 1 of the present embodiment, a flat magnetic coupling degree is obtained in a wide range regardless of the offset in the x direction, whereas in the coil component 1a of the comparative example, the magnetic coupling degree is greatly reduced when the offset in the x direction is small (i.e., when the central axis of the coil component 1a and the power receiving coil 3 are substantially aligned). This phenomenon occurs for the following reasons. That is, since the density of the magnetic flux passing through the inner diameter region of the coil becomes particularly high at the edge of the inner diameter region, in the coil component 1a of the comparative example, when the offset in the x direction is small, the edge of the inner diameter region of the coil component 1a that overlaps with the inner diameter region of the power receiving coil 3 is insufficient.

[0103] Considering this, in the coil component 1 of the present embodiment, since the central portion in the x direction of the winding region is deformed so as to bulge in the +y direction and the -y direction, Figure 7As shown in (a), even when the central axis of the coil component 1 is substantially consistent with the central axis of the power receiving coil 3, the edge of the inner diameter area of ​​the coil component 1 overlapping with the inner diameter area of ​​the power receiving coil 3 increases. Fig. 9 As shown, flat characteristics can be obtained in a wide range.

[0104] As described above, when the coil component 1 of the present embodiment is used as a power transmission coil of a wireless power transmission device, wireless power transmission can be performed correctly even when the center axis of the coil component 1 and the center axis of the power receiving coil 3 are offset in the x direction. In order to fully obtain such an effect, it is preferred to design the inner width Wx2in to be larger than the inner width Wy2in. Moreover, since the magnetic coupling degree of the coil component 1 of the present embodiment will not be significantly reduced even when the center axis of the coil component 1 is roughly consistent with the center axis of the power receiving coil 3, a flat characteristic can be obtained. In particular, in the present embodiment, since Rin>Rout is satisfied, a sufficient magnetic coupling degree can be obtained when the center axis of the coil component 1 is roughly consistent with the center axis of the power receiving coil 3.

[0105] In order to make the inner diameter ratio Rin larger than the outer diameter ratio Rout, for example, the winding width defined by the distance in the y direction between the outer shape section 176 and the inner shape section 186 may be increased. In this case, if the pattern width of each turn is simply increased, there is a risk of increasing eddy current loss, but in this embodiment, since each turn is divided into a plurality of lines in the radial direction by a spiral slit, the pattern width of each line is made thinner, and the increase of eddy current loss can be suppressed.

[0106] In addition, since the coil component 1 of the present embodiment has each line extending straight in the oblique direction in the winding regions 194, 195, 197, and 198, it is possible to suppress the change in the degree of magnetic coupling relative to the change in the offset in the x direction of the power receiving coil 3. This is because, when there are lines extending in the y direction in the winding regions 194, 195, 197, and 198, the degree of magnetic coupling changes sharply with only a slight change in the offset in the x direction, whereas, in the coil component 1 of the present embodiment, since there are no lines extending in the y direction in the winding regions 194, 195, 197, and 198, and each line extends straight in the oblique direction, the degree of magnetic coupling does not change sharply even if the offset in the x direction changes.

[0107] Furthermore, in the coil component 1 of the present embodiment, the length of each wire in the winding regions 194, 195, 197, and 198 is shorter than the length of each wire in the winding regions 193 and 196. This is because the winding regions 194, 195, 197, and 198 are intervals required to expand the diameter in the y direction, and if the intervals are long, the size of the coil component 1 may become larger than necessary.

[0108] Furthermore, in the coil component 1 of the present embodiment, since the pattern width P2 is narrower than the pattern width P1, the loss caused by the heat generated by the eddy current can also be reduced. That is, by reducing the pattern width P1 on the inner circumference side, the magnetic flux that interferes with the line on the inner circumference side with high magnetic flux density is reduced, thereby reducing the generated eddy current.

[0109] Furthermore, the pattern thickness of the conductor pattern may be thinner at the innermost turn than at the outermost turn. It is particularly preferred that the pattern thickness gradually or stepwise becomes thinner from the outermost turn toward the innermost turn. Thus, the effect of reducing the loss caused by narrowing the pattern width becomes significant on the inner side which is more strongly affected by the eddy current.

[0110] As mentioned above, although the preferred embodiment of the present invention has been described, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention, and these modifications are naturally included in the scope of the present invention.

[0111] For example, in the above embodiment, the first and second coil patterns 100 and 200 are respectively formed on the front and back surfaces of the substrate 10, but this is not essential in the present invention. In addition, the current flowing between the terminal electrodes E1 and E2 can be increased by overlapping a plurality of groups consisting of the first and second coil patterns 100 and 200 and connecting them in parallel.

[0112] Furthermore, in the above-described embodiment, each turn of the first and second coil patterns 100 and 200 is divided into four lines by the spiral slits, but such division is not essential in the present invention. Furthermore, even when division is performed, the number of divisions is not limited to four.

[0113] [Example]

[0114] A coil component of Example 1 having the same structure as the coil component 1 of the above-described embodiment was produced, and a sintered ferrite having a relative magnetic permeability of 1000 and a thickness of 0.5 mm was arranged on the other surface 12 side of the substrate 10, and a power receiving coil was arranged on the one surface 11 side of the substrate 10. The power receiving coil was a circular coil having an outer shape of 40 mm and an inner shape of 10 mm, and was separated from the coil component of Example 1 by 4 mm, and a sintered ferrite having a relative magnetic permeability of 1000 and a thickness of 0.5 mm was arranged on the side opposite to the coil component of Example 1. The outer shape width and the inner shape width in Example 1 are as follows.

[0115] Overall width Wx2out: 80mm

[0116] Overall width Wx1out: 40mm

[0117] Overall width Wy2out: 60mm

[0118] Overall width Wx1out: 50mm

[0119] Inner width Wx2in: 32mm

[0120] Inner width Wx1in: 20.1mm

[0121] Inner width Wy2in: 12mm

[0122] Inner width Wx1in: 2mm

[0123] Therefore, the outer ratio Rout is 1.2, the inner ratio Rin is 6, and the value of Rin / Rout is 5.00.

[0124] For the coil component of Example 1 having such parameters, the degree of magnetic coupling was measured when the power receiving coil was arranged with its central axes aligned, and when the power receiving coil was arranged with its central axis shifted by 20 mm in the x direction.

[0125] A coil component of Example 2 was prepared having the same parameters as in Example 1 except that the inner width was as follows, and the degree of magnetic coupling was measured under the same conditions as in Example 1.

[0126] Inner width Wx2in: 37mm

[0127] Inner width Wx1in: 22.2mm

[0128] Inner width Wy2in: 17mm

[0129] Inner width Wx1in: 7mm

[0130] Therefore, the internal aspect ratio Rin is 2.43 and the value of Rin / Rout is 2.02.

[0131] A coil component of Example 3 was prepared having the same parameters as in Example 1 except that the inner width was as follows, and the degree of magnetic coupling was measured under the same conditions as in Example 1.

[0132] Inner width Wx2in: 50mm

[0133] Inner width Wx1in: 27.6mm

[0134] Inner width Wy2in: 30mm

[0135] Inner width Wx1in: 20mm

[0136] Therefore, the internal aspect ratio Rin is 1.5 and the value of Rin / Rout is 1.25.

[0137] A coil component of Example 4 was prepared having the same parameters as in Example 1 except that the inner width was as follows, and the degree of magnetic coupling was measured under the same conditions as in Example 1.

[0138] Inner width Wx2in: 53mm

[0139] Inner width Wx1in: 28.8mm

[0140] Inner width Wy2in: 33mm

[0141] Inner width Wx1in: 23mm

[0142] Therefore, the internal aspect ratio Rin is 1.43 and the value of Rin / Rout is 1.2.

[0143] A coil component of Example 5 was prepared having the same parameters as in Example 1 except that the inner width was as follows, and the degree of magnetic coupling was measured under the same conditions as in Example 1.

[0144] Inner width Wx2in: 60mm

[0145] Inner width Wx1in: 31.7mm

[0146] Inner width Wy2in: 40mm

[0147] Inner width Wx1in: 30mm

[0148] Therefore, the internal aspect ratio Rin is 1.33 and the value of Rin / Rout is 1.11.

[0149] Production with Figure 8The magnetic coupling degree of the coil component of Comparative Example 1 having the same structure as the coil component 1a of Comparative Example shown was measured under the same conditions as those of Example 1. The outer width and inner width of Comparative Example 1 are as follows.

[0150] Overall width Wx2out: 80mm

[0151] Overall width Wy2out: 60mm

[0152] Inner width Wx2in: 60mm

[0153] Inner width Wy2in: 40mm

[0154] The measurement results are shown in Fig.10 .like Fig.10 As shown, in the coil component of Comparative Example 1, when the central axis is aligned with the coil axis of the power receiving coil (in Fig.10 In contrast, in the coil components of Examples 1 to 5, such a reduction in magnetic coupling is suppressed, and in particular, in the coil components of Examples 1 to 4 where the value of Rin / Rout is 1.2 or more, no reduction in magnetic coupling occurs.

Claims

1. A coil component, characterized in that: have: substrate; and a spiral first coil pattern provided on one surface of the substrate, The outer shape and inner shape of the first coil pattern are both such that the width in a first direction is greater than the width in a second direction orthogonal to the first direction, the outer shape is a shape along the outer peripheral edge of a line located at the outermost periphery, and the inner shape is a shape along the inner peripheral edge of a line located at the innermost periphery of the first coil pattern. The first coil pattern has an outer shape having: a pair of first outer shape sections, whose width in the second direction is a first outer shape width; and a second outer shape interval, which is located between the pair of first outer shape intervals in the first direction, and has a second outer shape width in the second direction that is larger than the first outer shape width, The inner shape of the first coil pattern has: a pair of first inner shape intervals, whose width in the second direction is the first inner shape width; and a second inner shape interval, which is located between the pair of first inner shape intervals in the first direction, and whose width in the second direction is the second inner shape width larger than the first inner shape width, An inner shape ratio, which is a ratio of the second inner shape width to the first inner shape width, is greater than an outer shape ratio, which is a ratio of the second outer shape width to the first outer shape width.

2. The coil component according to claim 1, characterized in that The ratio of the inner aspect ratio to the outer aspect ratio is 1.2 or more.

3. The coil component according to claim 1, characterized in that The width of the inner shape of the coil pattern in the first direction is greater than the width of the second inner shape.

4. The coil component according to any one of claims 1 to 3, characterized in that: Each of the plurality of turns constituting the first coil pattern includes: a first winding region whose extending direction from the outer peripheral end to the inner peripheral end changes by 180°; a second winding region whose extending direction from the outer peripheral end to the inner peripheral end changes by 180°; and a third winding region whose extending direction is consistent with the first direction; a fourth winding region, the extension direction of which has a predetermined slope relative to the first direction, and which connects one end of the first winding region and one end of the third winding region in a straight line; and a fifth winding region, the extending direction of which has a predetermined slope with respect to the first direction and which linearly connects one end of the second winding region and the other end of the third winding region.

5. The coil component according to claim 4, characterized in that In each of the plurality of turns, the length of each of the fourth and fifth winding regions in the extending direction of the first coil pattern is shorter than the length of each of the third winding region in the extending direction of the first coil pattern.

6. The coil component according to claim 4, characterized in that Each of the plurality of turns is divided into a plurality of lines in a radial direction by a spiral slit.

7. The coil component according to claim 6, characterized in that It also includes a spiral second coil pattern provided on the other surface of the substrate, Each of the plurality of turns constituting the second coil pattern is divided into a plurality of lines in the radial direction by a spiral slit. The innermost turn constituting the first coil pattern includes a first line and a second line located on an outer peripheral side than the first line. The innermost turn constituting the second coil pattern includes a third wire and a fourth wire located on an outer peripheral side than the third wire. The inner peripheral end of the first wire and the inner peripheral end of the fourth wire are connected to each other via a first connection portion provided through the substrate. The inner peripheral end of the second wire and the inner peripheral end of the third wire are connected to each other via a second connection portion provided through the substrate.

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