JP7147230B2 - coil parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coil component, and more particularly to a coil component having a planar spiral coil pattern.

In recent years, attention has been paid to wireless power transmission systems that transmit power without using power cables or power cords. Since the wireless power transmission system can wirelessly supply power from the power transmission side to the power reception side, it can be applied to various products such as transportation equipment such as trains and electric vehicles, home appliances, electronic equipment, wireless communication equipment, toys, and industrial equipment. is expected. A wireless power transmission system uses a power transmission coil and a power reception coil, and wirelessly transmits power by interlinking a magnetic flux generated by the power transmission coil with the power reception coil.

As a coil component for a wireless power transmission system, Patent Documents 1 and 2 disclose a coil component in which a plurality of planar spiral coil patterns are connected in parallel. If a plurality of coil patterns are connected in parallel, a larger current can flow through the power transmitting coil and the power receiving coil, so that the power that can be wirelessly transmitted can be increased.

JP-A-2016-93088 JP 2008-205215 A

However, in the coil components described in Patent Documents 1 and 2, the pattern shapes of a plurality of coil patterns connected in parallel are substantially the same. There is a problem that a difference occurs in the impedance of the pattern, and the current bias caused by the impedance difference increases the loss.

Regarding this, in Patent Document 1, a first coil unit is formed by connecting in series a coil pattern closest to the magnetic sheet and a coil pattern farthest from the magnetic sheet, and A second coil unit is formed by connecting in series the coil pattern with the second closest distance and the coil pattern with the second farthest distance from the magnetic sheet, and these first and second coil units are connected in parallel. It has been proposed to balance the impedance by However, this method has a problem that the impedances of the first coil unit and the second coil unit do not necessarily match depending on the positional relationship between the magnetic sheet and each coil pattern.

The same is true for Patent Document 2, and a configuration is disclosed in which two coil patterns are connected in series to form one coil unit and the two coil units are connected in parallel. It is difficult to match the impedances of the two coil units only by changing the combination of the two coil patterns, and there is a problem that the current bias due to the impedance difference increases the loss.

In addition, the coil components described in Patent Documents 1 and 2 are premised on the presence of four or more coil patterns, and when connecting fewer coils in parallel, it is impossible to balance the impedance. Can not.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a coil component in which two or more coil patterns are connected in parallel, and which can further reduce the difference in impedance due to the distance from the magnetic sheet. do.

A coil component according to the present invention includes a magnetic sheet, and first and second coil patterns spirally wound over a plurality of turns and arranged so as to overlap the magnetic sheet in a plan view. The coil pattern and the second coil pattern are connected in parallel, the first coil pattern is arranged closer to the magnetic sheet than the second coil pattern, and the line length of the second coil pattern is the same as that of the first coil. It is characterized by being longer than the line length of the pattern.

According to the present invention, since the line lengths of the first coil pattern and the second coil pattern are different, the impedance of each coil pattern can be finely adjusted. As a result, the impedance difference between the first coil pattern and the second coil pattern can be made smaller, so that the impedance difference of the entire coil component can be reduced. As a result, it is possible to reduce the loss caused by the impedance difference.

In the present invention, the inner diameter of the second coil pattern may be larger than the inner diameter of the first coil pattern. According to this, since the inner diameter of the second coil pattern is larger than the inner diameter of the first coil pattern, the line length of the second coil pattern can be increased.

In the present invention, the outer diameter of the second coil pattern may be larger than the outer diameter of the first coil pattern. According to this, since the outer diameter of the second coil pattern is larger than the outer diameter of the first coil pattern, the line length of the second coil pattern can be increased.

In the present invention, the number of turns of the first coil pattern and the number of turns of the second coil pattern may be the same. Even in this case, the line length of the second coil pattern can be increased by making the inner diameter or the outer diameter of the second coil pattern larger than that of the first coil pattern.

In the present invention, the second coil pattern may have more turns than the first coil pattern. According to this, since the number of turns of the second coil pattern is larger than the number of turns of the first coil pattern, the line length of the second coil pattern can be increased.

In the present invention, the first and second coil patterns are composed of the innermost turn located on the innermost circumference, the outermost turn located on the outermost circumference, and the number of turns counted from the innermost or outermost turn. The first coil pattern has an intermediate turn that is in the middle of the whole and a center position of the line length, and the pattern width at the center position is larger than the pattern width of the innermost turn and the pattern width of the outermost turn. is larger, and the total or average pattern width of each turn from the outermost turn to the intermediate turn is larger than the total or average of the pattern width of each turn from the innermost peripheral turn to the intermediate turn. In the second coil pattern, the pattern width at the center position is larger than the pattern width of the innermost and outermost turns, and the pattern width of each turn from the innermost to intermediate turns is larger than that of the innermost and outermost turns. The total or average pattern width of each turn from the outermost turn to the intermediate turn may be larger than the total or average pattern width. According to this, since the pattern width of the innermost peripheral turn and the pattern width of the outermost peripheral turn are narrowed, the loss caused by the influence of the magnetic field can be reduced. Moreover, the total or average pattern width of each turn from the innermost turn to the intermediate turn is larger than the total or average value of the pattern width of each turn from the innermost peripheral turn to the intermediate turn. , the loss on the inner peripheral side, which is more strongly affected by the magnetic field, is further reduced. Therefore, it is possible to further reduce the AC resistance as compared with the case where the pattern width of the coil pattern is simply symmetrical on the inner and outer peripheral sides.

In the present invention, the pattern width at the center position of the first coil pattern is larger than the pattern width of the intermediate turns, and the pattern width of the second coil pattern at the center position is larger than the pattern width of the intermediate turns. It doesn't matter if it's big. According to this, since the pattern width of the portion where the influence of the magnetic field is small is increased, it is possible to reduce the DC resistance while reducing the loss due to the influence of the magnetic field.

In the present invention, the pattern width of the innermost turns of the first coil pattern is smaller than the pattern width of the outermost turns, and the pattern width of the innermost turns of the second coil pattern is smaller than the pattern width of the outermost turns. It does not matter if the pattern width of . According to this, it is possible to further reduce the loss in the innermost turn that is most strongly affected by the magnetic field.

The coil component according to the present invention further includes first and second substrates arranged so as to overlap the magnetic sheet in plan view, the first coil pattern is formed on one surface of the first substrate, and the The second coil pattern may be formed on one surface of the second substrate. According to this, it is possible to form two coil patterns having different line lengths on different substrates.

The coil component according to the present invention further comprises third and fourth coil patterns spirally wound over a plurality of turns, the third coil pattern being formed on the other surface of the first substrate, The fourth coil pattern is formed on the other surface of the second substrate, the inner peripheral end of the first coil pattern and the inner peripheral end of the third coil pattern are connected to each other, and the inner peripheral end of the second coil pattern is connected to the inner peripheral end of the third coil pattern. The peripheral end and the inner peripheral end of the fourth coil pattern may be connected to each other, and the line length of the fourth coil pattern may be longer than the line length of the third coil pattern. According to this, the first and third coil patterns connected in series form a first coil unit, and the second and fourth coil patterns connected in series form a second coil unit. In addition, it is possible to reduce the difference in inductance between these two coil units.

In the present invention, each turn constituting the first coil pattern is composed of a plurality of conductor patterns including first and second conductor patterns separated in the radial direction by spiral slits, and a third coil pattern. Each constituting turn may consist of a plurality of conductor patterns including third and fourth conductor patterns separated in the radial direction by a spiral slit. According to this, since the bias of the current density is reduced, it becomes possible to further reduce the direct current resistance and the alternating current resistance.

In the present invention, the first conductor pattern is located on the outer peripheral side of the second conductor pattern, the third conductor pattern is located on the outer peripheral side of the fourth conductor pattern, and is located on the outer peripheral side of the first conductor pattern. The inner peripheral end and the inner peripheral end of the fourth conductor pattern may be connected to each other, and the inner peripheral end of the second conductor pattern and the inner peripheral end of the third conductor pattern may be connected to each other. According to this, the current density distributions of the conductor pattern positioned on the inner peripheral side and the conductor pattern positioned on the outer peripheral side are made more uniform, so that the direct current resistance and the alternating current resistance can be further reduced.

As described above, the coil component according to the present invention can further reduce the difference in impedance due to the distance from the magnetic sheet, so it is possible to provide a coil component with small resistance loss in alternating current. Therefore, if the coil component according to the present invention is used as a power receiving coil or a power transmitting coil of a wireless power transmission system, it is possible to reduce heat generation accompanying power transmission.

FIG. 1 is a schematic cross-sectional view for explaining the configuration of a coil component 1 according to a first embodiment of the invention. FIG. 2 is a schematic plan view for explaining the pattern shape of the coil pattern 100 forming the coil unit U1. FIG. 3 is a schematic plan view for explaining the pattern shape of the coil pattern 300 forming the coil unit U1. FIG. 4 is an equivalent circuit diagram of the coil component 1. FIG. FIG. 5 is a block diagram of a wireless power transmission system using the coil component 1. As shown in FIG. FIG. 6 is a schematic cross-sectional view for explaining the configuration of a coil component 1a according to a first modification of the first embodiment. FIG. 7 is a schematic cross-sectional view for explaining the configuration of a coil component 1b according to a second modification of the first embodiment. FIG. 8 is a schematic cross-sectional view taken along line DD shown in FIGS. 2 and 3. FIG. FIG. 9 is a graph for explaining the relationship between the radial position of the conductor pattern and the pattern width. FIG. 10 is a schematic cross-sectional view for explaining the definition of intermediate turns when the total number of turns is odd. FIG. 11 is a schematic cross-sectional view for explaining the definition of intermediate turns when the total number of turns is even. FIG. 12 is a schematic plan view for explaining the definition of intermediate turns when the total number of turns is even. FIG. 13 is a schematic plan view for explaining the definition of intermediate turns when the total number of turns is odd. FIG. 14 is a schematic cross-sectional view of a coil unit according to a modification. FIG. 15 is a schematic plan view for explaining the pattern shape of the first coil pattern 100a included in the coil component 2 according to the second embodiment of the invention. FIG. 16 is a schematic plan view for explaining the pattern shape of the third coil pattern 300a included in the coil component 2 according to the second embodiment of the invention. 17 is an equivalent circuit diagram of the coil component 2. FIG.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

<First embodiment>
FIG. 1 is a schematic cross-sectional view for explaining the configuration of a coil component 1 according to a first embodiment of the invention.

As shown in FIG. 1, the coil component 1 according to this embodiment includes a magnetic sheet 3 and three coil units U1 to U3 arranged so as to overlap the magnetic sheet 3. As shown in FIG. The magnetic sheet 3 is a sheet member made of a high magnetic permeability material such as ferrite, permalloy, or composite magnetic material, and functions as a magnetic path for magnetic flux interlinking the coil units U1 to U3.

The coil units U1 to U3 are units in which coil patterns are formed on both sides of a substrate, and are arranged on the magnetic sheet 3 so that their inner diameter regions overlap when viewed from above. As for the distance from the magnetic sheet 3, the coil unit U1 is the closest and the coil unit U3 is the farthest. That is, when the distances in the coil axial direction between the magnetic sheet 3 and the coil units U1 to U3 are D1 to D3, respectively,
D1<D2<D3
is.

The coil unit U1 includes a substrate 10, a first coil pattern 100 formed on one surface 11 of the substrate 10, and a third coil pattern 300 formed on the other surface 12 of the substrate 10. . The coil unit U2 includes a substrate 20, a second coil pattern 200 formed on one surface 21 of the substrate 20, and a fourth coil pattern 400 formed on the other surface 22 of the substrate 20. . The coil unit U3 includes a substrate 30, a fifth coil pattern 500 formed on one surface 31 of the substrate 30, and a sixth coil pattern 600 formed on the other surface 32 of the substrate 30. . Materials for the substrates 10, 20, and 30 are not particularly limited, but transparent or translucent flexible materials such as PET resin can be used. Further, the substrates 10, 20, and 30 may be flexible substrates made of glass cloth impregnated with epoxy resin. Further, in the present embodiment, the coil patterns 100, 200, 300, 400, 500, 600 have the same number of turns.

As shown in FIG. 1, coil patterns 100 and 300 forming coil unit U1 have an inner diameter of φ1A and an outer diameter of φ1B, and coil patterns 200 and 400 forming coil unit U2 have an inner diameter of φ2A and an outer diameter of φ2B. , When the inner diameter of the coil patterns 500 and 600 constituting the coil unit U3 is φ3A and the outer diameter is φ3B, in this embodiment,
φ1A<φ2A<φ3A
and
φ1B<φ2B<φ3B
meets That is, the coil unit U1 closest to the magnetic sheet 3 has the smallest inner diameter φ1A and outer diameter φ1B, and the coil unit U3 farthest from the magnetic sheet 3 has the largest inner diameter φ3A and outer diameter φ3B.

Since the coil patterns 100, 200, 300, 400, 500, and 600 have the same number of turns, the coil pattern forming the coil unit U2 is longer than the line length of the coil patterns 100 and 300 forming the coil unit U1. The line lengths of 200 and 400 are longer, and the line lengths of coil patterns 500 and 600 forming coil unit U3 are longer than the line lengths of coil patterns 200 and 400 forming coil unit U2. In this embodiment, as will be described later, the coil patterns 100, 200, 300, 400, 500, and 600 have a plurality of parallel lines radially divided by spiral slits. The average line length of a plurality of divided lines of the patterns 100, 200, 300, 400, 500, 600 may be considered as the line length of each coil pattern 100, 200, 300, 400, 500, 600.

2 and 3 are schematic plan views for explaining the pattern shapes of the coil patterns 100 and 300 constituting the coil unit U1, respectively.

As shown in FIG. 2, the first coil pattern 100 is composed of a plane conductor spirally wound over a plurality of turns. In the example shown in FIG. 2, the first coil pattern 100 has a five-turn configuration consisting of turns 110 to 150, the turn 110 forming the outermost turn and the turn 150 forming the innermost turn. Each turn 110 to 150 is radially divided into four by three spiral slits. As a result, turn 110 is divided into conductor patterns 111-114, turn 120 is divided into conductor patterns 121-124, turn 130 is divided into conductor patterns 131-134, and turn 140 is divided into conductor patterns 141-144. , the turn 150 is divided into conductor patterns 151-154. Therefore, when viewed in units of divided conductor patterns, the conductor pattern 111 constitutes the outermost turn, and the conductor pattern 154 constitutes the innermost turn.

The conductor patterns 111 to 114 of the turn 110 positioned at the outermost periphery are connected to the terminal electrode E1a via the lead pattern 171 extending in the radial direction. A radially extending lead pattern 172 is provided at a position adjacent to the lead pattern 171 in the circumferential direction, and its tip end is connected to the terminal electrode E2b. On the other hand, the inner peripheral ends of conductor patterns 151-154 of turn 150 positioned at the innermost periphery are connected to through-hole conductors H1-H4, respectively.

Each of the turns 110 to 150 forming the first coil pattern 100 has a circumferential area A1 whose position in the radial direction does not change and a transition area B1 in which the position in the radial direction transitions. Five turns consisting of turns 110 to 150 are defined as boundaries. As shown in FIG. 2, in this embodiment, both the outer peripheral end and the inner peripheral end of the first coil pattern 100 are located in the transition region B1. Furthermore, when a virtual line L1 extending radially from the center point C1 of the first coil pattern 100 and passing between the lead pattern 171 and the lead pattern 172 is drawn, the transition region B1 is positioned on the virtual line L1. ing. Further, the through-hole conductor H1 and the through-hole conductor H4 are arranged at symmetrical positions with respect to the virtual line L1, and the through-hole conductors H2 and H3 are arranged at symmetrical positions with respect to the virtual line L1. are placed in

As shown in FIG. 3, the third coil pattern 300 is composed of a plane conductor spirally wound over a plurality of turns. In the example shown in FIG. 3, the third coil pattern 300 has a 5-turn configuration consisting of turns 310 to 350, with the turn 310 forming the outermost turn and the turn 350 forming the innermost turn. Each turn 310 to 350 is radially divided into four by three spiral slits. As a result, turn 310 is divided into conductor patterns 311-314, turn 320 is divided into conductor patterns 321-324, turn 330 is divided into conductor patterns 331-334, and turn 340 is divided into conductor patterns 341-344. , the turn 350 is divided into conductor patterns 351-354. Therefore, when viewed in units of divided conductor patterns, the conductor pattern 311 constitutes the outermost turn, and the conductor pattern 354 constitutes the innermost turn.

The conductor patterns 311 to 314 of the turn 310 located on the outermost periphery are connected to the terminal electrode E2a via the lead pattern 371 extending in the radial direction. A radially extending lead pattern 372 is provided at a position adjacent to the lead pattern 371 in the circumferential direction, and its tip end is connected to the terminal electrode E1b. On the other hand, the inner peripheral ends of the conductor patterns 351 to 354 of the innermost turn 350 are connected to the through-hole conductors H4, H3, H2 and H1, respectively.

Each of the turns 310 to 350 forming the third coil pattern 300 has a circumferential region A2 whose position in the radial direction does not change and a transition region B2 in which the position in the radial direction transitions. Five turns consisting of turns 310 to 350 are defined as boundaries. As shown in FIG. 3, both the outer peripheral end and the inner peripheral end of the third coil pattern 300 are located in the transition region B2 in this embodiment. Furthermore, when a virtual line L2 extending radially from the center point C2 of the third coil pattern 300 and passing between the lead pattern 371 and the lead pattern 372 is drawn, the transition region B2 is positioned on the virtual line L2. ing.

The first and third coil patterns 100, 300 having such configurations are arranged on one surface 11 and the other surface of the substrate 10, respectively, so that the center points C1, C2 overlap and the imaginary lines L1, L2 overlap. 12 is formed. As a result, the terminal electrodes E1a and E1b are overlapped, and the terminal electrodes E2a and E2b are overlapped. The terminal electrodes E1a and E1b are short-circuited through a through-hole conductor H5 that connects the lead pattern 171 and the lead pattern 372, and are used as a single terminal electrode E1. Similarly, the terminal electrodes E2a and E2b are short-circuited via a through-hole conductor H6 connecting the lead pattern 172 and the lead pattern 371, and used as a single terminal electrode E2.

Furthermore, the conductor patterns 151 and 354 are short-circuited to each other via the through-hole conductor H1, the conductor patterns 152 and 353 are short-circuited to each other via the through-hole conductor H2, and the conductor patterns 153 and 352 are short-circuited to each other via the through-hole conductor H3. 4, the first coil pattern 100 and the third coil pattern 300 are connected in series as shown in FIG. A spiral coil of turns will be constructed.

The other coil units U2 and U3 also have the same configuration as the coil unit U1 except that they have different inner and outer diameters. That is, the coil patterns 200 and 400 forming the coil unit U2 are also connected in series, and the coil patterns 500 and 600 forming the coil unit U3 are also connected in series. These coil units U1 to U3 are connected in parallel with each other as shown in FIG. This makes it possible to pass about three times as much current as when using only one coil unit.

The coil component 1 according to this embodiment can be applied to the wireless power transmission system shown in FIG. The wireless power transmission system shown in FIG. 5 is a system comprising a wireless power transmission device TX and a wireless power reception device RX. By making the coils 61 face each other, power can be transmitted wirelessly. The power transmission coil 51 is connected to a power transmission circuit 52 including a power supply circuit, an inverter circuit, a resonance circuit, and the like, and is supplied with alternating current from the power transmission circuit 52 . The power receiving coil 61 is connected to a power receiving circuit 62 including a resonance circuit, a rectifying circuit, a smoothing circuit, and the like. When the power transmission coil 51 and the power reception coil 61 are magnetically coupled by facing each other, power can be wirelessly transmitted from the wireless power transmission device TX to the wireless power reception device RX via the space 40 .

In the wireless power transmission system having such a configuration, the coil units U1 to U3 of the coil component 1 according to this embodiment can be used as the power transmitting coil 51 and the power receiving coil 61. FIG. In this case, the magnetic sheet 53 arranged on the opposite side of the space 40 when viewed from the power transmission coil 51 and the magnetic sheet 63 arranged on the opposite side of the space 40 when viewed from the power receiving coil 61 are the magnetic sheets 3 shown in FIG. corresponds to By arranging the magnetic sheets 53 and 63 (magnetic sheet 3), the inductance of the power transmitting coil 51 and the power receiving coil 61 (coil units U1 to U3) is increased, making it possible to perform more efficient power transmission.

On the other hand, if the magnetic sheet 3 exists, even if the coil units U1 to U3 have the same number of turns, the impedance of each of the coil units U1 to U3 differs due to the inductance difference according to the distance from the magnetic sheet 3. occurs. If there is an impedance difference between the coil units U1 to U3, the loss will increase due to current imbalance caused by the impedance difference. As a result, when it is used as the power receiving coil 51 or the power transmitting coil 61 of the wireless power transmission system shown in FIG.

Considering this point, in the present embodiment, a difference is provided in line length between the coil units U1 to U3. That is, by making the line length of the coil unit U1, which is closest to the magnetic sheet 3 and thus has the highest impedance, shorter than the line length of the coil unit U2, the inductance is reduced and the distance from the magnetic sheet 3 is reduced. is the farthest, and thus the line length of the coil unit U3, which has the lowest impedance, is made longer than the line length of the coil unit U2, thereby increasing the inductance. As a result, the inductance difference between the three coil units U1 to U3 is reduced, so that the current imbalance caused by the impedance difference is reduced and ideally matched. As a result, it is possible to reduce the loss of the entire circuit shown in FIG.

In this embodiment, since the impedance of each coil unit U1 to U3 is adjusted by the line length of the coil pattern, it is possible to finely adjust the impedance. Therefore, by appropriately designing the line length according to parameters such as the distance from the magnetic sheet 3 and the number of turns, it is possible to reliably reduce the impedance difference between the coil units U1 to U3.

In the example shown in FIG. 1, both the inner diameter and the outer diameter are configured to increase in order of the coil units U1, U2, and U3, but this point is not essential in the present invention. Therefore, like the coil component 1a according to the first modified example shown in FIG.
Thus, the line lengths of the coil units U1, U2, and U3 may be increased in order, and like the coil component 1b according to the second modification shown in FIG. and set the inner diameters of the coil units U1 to U3 to φ1A<φ2A<φ3A
By doing so, the line lengths of the coil units U1, U2, and U3 may be increased in this order. Furthermore, although not shown, in addition to or instead of providing a difference in the inner diameter or outer diameter of the coil units U1 to U3, the number of turns of the coil units U1, U2 and U3 may be increased in this order.

FIG. 8 is a schematic cross-sectional view taken along line DD shown in FIGS. 2 and 3. FIG. 2 and 3 correspond to the cross section of the coil unit U1, but the cross sections of the other coil units U2 and U3 are the same as those shown in FIGS. is the same as the DD section shown in FIG.

Although not particularly limited, as shown in FIG. The conductor patterns completely match in position in the planar direction. As a result, the area of the portion where the substrate 10 is covered with the conductor pattern in a plan view is reduced, so that eddy current loss can be reduced. Moreover, by overlapping each conductor pattern positioned in the circumferential area A1 and each conductor pattern positioned in the circumferential area A2, visual interference between the first coil pattern 100 and the third coil pattern 300 can be minimized. can be suppressed. That is, even if the substrate 10 is transparent or translucent, the third coil pattern 300 does not become a visual obstacle when the first coil pattern 100 is visually inspected. The first coil pattern 100 does not become a visual obstruction when inspecting the appearance. Thereby, it becomes possible to correctly perform the appearance inspection using the inspection apparatus.

Although not particularly limited, in the coil component 1 according to the present embodiment, as shown in FIG. 8, the pattern widths of the first and third coil patterns 100 and 300 are not constant and The pattern width is narrow at the center side, and the pattern width is wide at the center side.

More specifically, the pattern width of the conductor patterns 154 and 354 forming the innermost turn is W1, the pattern width of the conductor patterns 111 and 311 forming the outermost turn is W2, and the innermost or outermost turn is W2. W3 is the pattern width of the conductor patterns 133, 333 (or 132, 332) that constitute the intermediate turns whose number of turns is the middle of the whole, and the conductor pattern that is the center position of the line length of the coil pattern along the conductor pattern. When the pattern width of 124 and 324 is W4,
W1, W2<W3, W4
meets

The reason why the pattern widths W1 and W2 of the innermost and outermost turns are reduced is that the magnetic field at this portion is strong and the heat generated by the eddy current causes a large loss. That is, by reducing the pattern widths W1 and W2 of the innermost and outermost turns, the magnetic flux that interferes with the innermost and outermost turns is reduced, thereby reducing the generated eddy current. . The pattern width W1 of the innermost peripheral turn is preferably larger than the pattern thickness of the coil patterns 100 and 300 . According to this, since the eddy currents flowing in the coil patterns 100 and 300 are concentrated on both sides in the radial direction of the conductor patterns, it is possible to obtain a significant loss reduction effect by narrowing the pattern widths of the coil patterns 100 and 300. becomes possible.

Furthermore, the pattern thickness of the conductor pattern may be thinner in the innermost turn than in the outermost turn. In particular, it is preferable that the pattern thickness becomes thinner gradually or stepwise from the outermost turn to the innermost turn. According to this, the effect of reducing the loss by narrowing the pattern width becomes remarkable on the inner peripheral side, which is more strongly affected by the eddy current.

FIG. 9 is a graph for explaining the relationship between the radial position of the conductor pattern and the pattern width. In FIG. 9, the solid line indicates the pattern width of the coil units U1 to U3, and the broken line indicates the pattern width in the reference example. The reference example is an example in which the pattern width of the conductor pattern is constant.

In the example shown in FIG. 9, the pattern width W1 of the innermost peripheral turn is the smallest, and the pattern width expands gradually or stepwise from the innermost peripheral turn toward the center position of the line length. The pattern width W4 is the maximum. Then, the pattern width is gradually or stepwisely reduced from the center position of the line length toward the outermost turn, and the pattern width becomes W2 at the outermost turn. In the example shown in FIG. 9, the pattern width W1 of the innermost turn is smaller than the pattern width W2 of the outermost turn. This is because the innermost turn has a stronger magnetic field than the outermost turn, and this is reflected in the pattern width. As a result, in the example shown in FIG.
W1<W2<W3<W4
meets In the reference example, the pattern width of the conductor pattern is W0 in all turns.

Further, the center position of the line length is positioned on the outer peripheral side of the intermediate turn, and the pattern width W4 is maximized at this portion. This is because the magnetic field is weaker at the center of the line length than at the intermediate turn, and this is reflected in the pattern width. In the example shown in FIG. 9, the center position of the line length has the maximum pattern width W4, and the pattern width decreases as the distance from this point increases. The total value or average value of the pattern widths of the turns located on the outer peripheral side as viewed from the intermediate turns is larger than the total value or average value of the pattern widths of the turns located on the inner peripheral side. That is, the area F2 of the graph shown in FIG. 9 is larger than the area F1. Thus, in the example shown in FIG. 9, the pattern width is not symmetrical between the inner and outer circumferences when considering the intermediate turn as the center.

Here, when the coil pattern T has an odd number of turns (for example, 11 turns) as shown in FIG. 10, the intermediate turns are the number of turns counted from the innermost turn Ti and the outermost turn To. The turn T1 (for example, the 6th turn) with the same number of turns is applicable.

When the coil pattern T has an even number of turns (for example, 10 turns) as shown in FIG. 5th turn counted from the outer edge), or turn T3 in which the number of turns counted from the outermost turn To is half of the total number of turns (for example, the 5th turn counted from the outer edge). When the coil pattern T has an even number of turns, both the turns T2 and T3 may be regarded as intermediate turns, or either one of them may be regarded as an intermediate turn. Also, the average value of the pattern width of the turn T2 and the pattern width of the turn T3 may be regarded as the pattern width W3 of the intermediate turn.

Furthermore, as shown in FIG. 12, the pattern width of the conductor pattern at the central position of the number of turns may be regarded as the pattern width W3 of the intermediate turns. In the example shown in FIG. 12, since the total number of turns of the coil pattern T is four, the pattern width of the position T4, which is exactly the second turn counted from the inner or outer peripheral end, is the pattern width W3 of the intermediate turn. I don't mind if you look at it. This point is the same when the total number of turns is an odd number. As shown in FIG. 13, if the total number of turns of the coil pattern T is 5 turns, the number of turns is exactly 2.0 from the inner or outer peripheral end. The pattern width at the fifth turn position T5 may be regarded as the pattern width W3 of the intermediate turn.

On the other hand, when each turn is divided in the radial direction by a spiral slit as in the present embodiment, each conductor pattern may be regarded as one turn and an intermediate turn may be specified. That is, regardless of whether or not one turn is divided into a plurality of conductor patterns, the intermediate turn can be specified based on the number of conductor patterns appearing in the cross section (20 in the example shown in FIG. 8).

Regarding the center position of the line length, if each turn is not divided radially by a spiral slit, that is, if the coil pattern is a simple spiral pattern, the center position of the coil length should be exactly in the middle of the coil length along the coil pattern. This is the position. On the other hand, when each turn is radially divided by a spiral slit as in this embodiment, the entire conductor pattern is a simple spiral pattern that can be written in one stroke from the inner peripheral end to the outer peripheral end. Assuming that there is a line length, the middle position of the coil length along the coil pattern may be set as the center position of the line length. In this case, in the example shown in FIG. 2, a total of 20 conductor patterns consisting of conductor patterns 111 to 114, 121 to 124, 131 to 134, 141 to 144, and 151 to 154 are connected in a spiral, thereby forming a coil pattern. This corresponds to the central position of the line length when 100 turns are assumed to be 20 turns. Alternatively, the lengths of a plurality of conductor patterns forming each turn may be averaged, the total length may be taken as the line length, and the center position may be defined based on this.

By designing the pattern width of the coil pattern according to the intensity of the magnetic field in this way, it is possible to further reduce the AC resistance as compared with the case where the pattern width is constant.

Moreover, in the coil component according to the present embodiment, each turn is radially divided into four by the spiral slits, so that current density bias is reduced compared to the case where such slits are not provided. As a result, DC resistance and AC resistance can be reduced. Moreover, since the radial positions of the conductor portions are completely interchanged between the first coil pattern 100 and the third coil pattern 300, the difference between the inner and outer circumferences is canceled out. As a result, the current density distribution is made uniform, so that the direct current resistance and the alternating current resistance can be further reduced.

In addition, in the example shown in FIG. 8, the space S between the radially adjacent turns has a constant width. As a result, there is no wasted space in the vicinity of the inner peripheral edge or the outer peripheral edge where the pattern width is narrow, so that the pattern width can be sufficiently secured, and the direct current resistance can be reduced. However, this point is not essential in the present invention, and the space S may be changed according to the pattern width as in the modification shown in FIG. In the example shown in FIG. 14, the pitch P in the radial direction of each conductor pattern is constant, so that the narrower the pattern width, the larger the space S, and the wider the pattern width, the smaller the space S. According to this, it is possible to obtain the same inductance as when the pattern width is constant.

<Second embodiment>
15 and 16 are schematic plan views for explaining pattern shapes of a first coil pattern 100a and a third coil pattern 300a, respectively, included in the coil component 2 according to the second embodiment of the present invention.

The first and third coil patterns 100a, 300a are patterns used instead of the first and third coil patterns 100, 300 shown in FIGS. Similar patterns are used, except that the inner or outer diameters are different.

As shown in FIG. 15, a first coil pattern 100a is obtained by adding conductor patterns 161 and 162 to the first coil pattern 100 shown in FIG. It has a configuration in which H7 and H8 are provided. The conductor pattern 161 is a one-turn conductor pattern continuing from the conductor pattern 151 , and the conductor pattern 162 is a one-turn conductor pattern continuing from the conductor pattern 152 . In this embodiment, through-hole conductors H3 and through-hole conductors H8 are arranged symmetrically about imaginary line L1, and through-hole conductors H4 and through-hole conductors H7 are symmetrical about imaginary line L1. are placed in different positions. Since other basic configurations are the same as those of the first coil pattern 100 shown in FIG. 2, the same reference numerals are given to the same elements, and redundant explanations will be omitted. The coil pattern 200 included in the coil unit U2 and the coil pattern 500 included in the coil unit U3 also have the same pattern shape as the first coil pattern 100a shown in FIG. 15 except that the inner diameter or the outer diameter is different. there is

As shown in FIG. 16, a third coil pattern 300a has conductor patterns 361 and 362 added to the third coil pattern 300 shown in FIG. It has a configuration in which H4 and H3 are provided. The conductor pattern 361 is a one-turn conductor pattern continuing from the conductor pattern 351 , and the conductor pattern 362 is a one-turn conductor pattern continuing from the conductor pattern 352 . Inner peripheral ends of the conductor patterns 353 and 354 are connected to through-hole conductors H8 and H7, respectively. Since other basic configurations are the same as those of the third coil pattern 300 shown in FIG. 3, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted. The coil pattern 400 included in the coil unit U2 and the coil pattern 600 included in the coil unit U3 also have the same pattern shape as the third coil pattern 300a shown in FIG. there is

The first and third coil patterns 100a and 300a having such configurations are arranged on one surface 11 and the other surface of the substrate 10, respectively, so that the center points C1 and C2 overlap and the imaginary lines L1 and L2 overlap. 12 is formed. As a result, the conductor patterns 153 and 362 are short-circuited through the through-hole conductor H3, the conductor patterns 154 and 361 are short-circuited through the through-hole conductor H4, and the conductor patterns 161 and 354 are short-circuited through the through-hole conductor H7. Since the conductor patterns 162 and 353 are short-circuited to each other through the through-hole conductors H8, the first coil pattern 100a and the third coil pattern 300a are connected in series as shown in FIG. An 11-turn spiral coil is thus constructed.

As described above, in this embodiment, although the same pattern shape is used on the front and back sides, it is possible to realize a spiral coil with an odd number of turns.

The other coil units U2 and U3 also have the same configuration as the coil unit U1 except that they have different inner and outer diameters. That is, the coil patterns 200 and 400 forming the coil unit U2 are also connected in series to form an 11-turn spiral coil, and the coil patterns 500 and 600 forming the coil unit U3 are also connected in series to form an 11-turn spiral coil. configure. These coil units U1 to U3 are connected in parallel with each other as shown in FIG. This makes it possible to pass about three times as much current as when using only one coil unit.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. Needless to say, it is included within the scope.

For example, in each of the above embodiments, three coil units U1 to U3 are used, but the present invention is not limited to this, and any coil unit or coil pattern connected in parallel may be provided. Enough.

In each of the above-described embodiments, one coil unit is configured by connecting in series two coil patterns formed on the front and back sides of the substrate, but the present invention is not limited to this. It is sufficient if each coil unit contains at least one coil pattern.

Furthermore, in each of the above-described embodiments, each turn that constitutes the coil pattern is separated into four conductor patterns by a spiral slit. Separation is not required. Further, even when the conductor patterns are separated into a plurality of conductor patterns, the number is not limited to four.

1, 1a, 1b, 2 coil component 3 magnetic sheets 10, 20, 30 substrates 11, 21, 31 substrate one surface 12, 22, 32 substrate other surface 40 space 51 power transmission coil 51 power reception coil 52 power transmission circuit 53 Magnetic sheet 61 Power receiving coil 61 Power transmitting coil 62 Power receiving circuit 63 Magnetic sheet 100, 100a First coil pattern 200 Second coil pattern 300, 300a Third coil pattern 400 Fourth coil pattern 500 Fifth coil pattern 600 6 coil patterns 110-150, 310-350 turns 111-114, 121-124, 131-134, 141-144, 151-154, 161, 162, 311-314, 321-324, 331-334, 341- 344, 351 to 354, 361, 342 conductor patterns 171, 172, 371, 372 lead patterns A1, A2 circumferential regions B1, B2 transition regions C1, C2 center points E1, E1a, E1b, E2, E2a, E2b terminal electrode F1 , F2 Areas H1 to H8 Through-hole conductors L1, L2 Virtual line P Pitch RX Wireless power receiver S Space T Coil pattern TX Wireless power transmitter Ti Innermost turn To Outermost turns U1 to U3 Coil units W1 to W4 Pattern width

Claims (10)

a magnetic sheet;
first and second substrates arranged so as to overlap with the magnetic sheet in plan view;
a first , second, third, and fourth coil pattern spirally wound over a plurality of turns and arranged so as to overlap the magnetic sheet in a plan view;
The first coil pattern is formed on one surface of the first substrate,
The second coil pattern is formed on one surface of the second substrate,
The third coil pattern is formed on the other surface of the first substrate,
The fourth coil pattern is formed on the other surface of the second substrate,
the inner peripheral end of the first coil pattern and the inner peripheral end of the third coil pattern are connected to each other;
the inner peripheral end of the second coil pattern and the inner peripheral end of the fourth coil pattern are connected to each other;
The first and third coil patterns and the second and fourth coil patterns are connected in parallel,
The first and third coil patterns are arranged closer to the magnetic sheet than the second and fourth coil patterns,
The line length of the second coil pattern is longer than the line length of the first coil pattern,
The line length of the fourth coil pattern is longer than the line length of the third coil pattern,
The first, second, third and fourth coil patterns have circumferential regions whose positions in the radial direction do not change,
each conductor pattern positioned in the circumferential area of the first coil pattern and each conductor pattern positioned in the circumferential area of the third coil pattern overlap each other in plan view;
Each conductor pattern positioned in the circumferential area of the second coil pattern and each conductor pattern positioned in the circumferential area of the fourth coil pattern overlap each other in plan view. . 2. The coil component according to claim 1, wherein the inner diameter of said second coil pattern is larger than the inner diameter of said first coil pattern. 3. The coil component according to claim 1, wherein the outer diameter of said second coil pattern is larger than the outer diameter of said first coil pattern. 4. The coil component according to claim 2, wherein said first coil pattern and said second coil pattern have the same number of turns. 4. The coil component according to claim 1, wherein the second coil pattern has more turns than the first coil pattern. The first and second coil patterns are composed of the innermost turn located on the innermost circumference, the outermost turn located on the outermost circumference, and the number of turns counted from the innermost or outermost turn. and a center position of the line length,
In the first coil pattern, the pattern width at the center position is larger than the pattern width of the innermost turn and the pattern width of the outermost turn, and from the innermost turn to the intermediate turn. The total or average pattern width of each turn from the outermost turn to the intermediate turn is larger than the total or average pattern width of each turn of
In the second coil pattern, the pattern width at the center position is larger than the pattern width of the innermost turn and the pattern width of the outermost turn, and from the innermost turn to the intermediate turn. 5, wherein the total or average pattern width of each turn from the outermost turn to the intermediate turn is larger than the total or average pattern width of each turn of The coil component according to any one of . The first coil pattern has a pattern width at the center position larger than the pattern width of the intermediate turn,
7. The coil component according to claim 6, wherein the pattern width of the second coil pattern at the center position is larger than the pattern width of the intermediate turns. In the first coil pattern, the pattern width of the innermost turn is smaller than the pattern width of the outermost turn,
8. The coil component according to claim 6, wherein the pattern width of the innermost turns of the second coil pattern is smaller than the pattern width of the outermost turns. Each turn that constitutes the first coil pattern consists of a plurality of conductor patterns including first and second conductor patterns that are radially separated by a spiral slit,
9. Each turn constituting the third coil pattern is composed of a plurality of conductor patterns including third and fourth conductor patterns radially separated by a spiral slit. The coil component according to any one of . The first conductor pattern is located on the outer peripheral side of the second conductor pattern,
the third conductor pattern is located on the outer peripheral side of the fourth conductor pattern,
the inner peripheral end of the first conductor pattern and the inner peripheral end of the fourth conductor pattern are connected to each other;
10. The coil component according to claim 9 , wherein the inner peripheral end of said second conductor pattern and the inner peripheral end of said third conductor pattern are connected to each other.

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