JP2019186235A - Coil component and wireless electric power transmission circuit with the same - Google Patents

Abstract

To provide a coil component having a spiral-shaped flat surface conductor, capable of reducing a loss caused by an influence of a magnetic field.SOLUTION: In a coil pattern 100 wound in spiral over a plurality of turns, a pattern width W4 at a center position is larger than a pattern width W1 of an innermost peripheral turn 154 and a pattern width W2 of an outermost peripheral turn 111, and a total value or a mean value of the pattern width of each turn from the outermost peripheral turn 111 to an intermediate turn 133 is larger than the total value or the mean value of the pattern width of each turn from the innermost peripheral turn 154 to an intermediate turn 113. According to the present invention, sine each conductive pattern is designed in the pattern width in accordance with intensity of a magnetic field, AC resistance can be more reduced as compared with the case where the pattern width of the coil pattern is simply formed symmetrically at an inner peripheral side and an outer peripheral side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil component, and more particularly to a coil component having a spiral planar conductor. The present invention also relates to a wireless power transmission circuit using such a coil component.

  As a coil component used in various electronic devices, in addition to a coil component in which a wire (coated conductor) is wound around a magnetic core, a coil in which a spiral planar conductor is formed over a plurality of turns on the surface of a substrate. Parts are known. For example, Patent Document 1 discloses a coil component in which a spiral planar conductor is wound over a plurality of turns and the pattern width of several turns located on the inner peripheral side and the outer peripheral side is narrowed. Since the coil patterns located on the inner and outer peripheral sides are strongly affected by the magnetic field, as described in Patent Document 1, if the pattern width in this portion is narrowed, the loss due to the influence of the magnetic field is reduced. It becomes possible to reduce.

  In Patent Document 1, the pattern width of the coil pattern is symmetric on the inner peripheral side and the outer peripheral side. That is, the pattern width of the nth turn counted from the inner periphery side is the same as the pattern width of the nth turn counted from the outer periphery side.

JP-A-11-040438

  However, since the strength of the magnetic field is different between the inner circumference side and the outer circumference side of the coil pattern, the loss cannot be reduced sufficiently by simply making the pattern width of the coil pattern symmetrical between the inner circumference side and the outer circumference side. For this reason, there was a problem that the AC resistance could not be reduced sufficiently.

  Therefore, an object of the present invention is to provide a coil component capable of further reducing the AC resistance by more effectively reducing the loss caused by the influence of the magnetic field, and a wireless power transmission path including the coil component. And

  A coil component according to the present invention includes a substrate and a first coil pattern formed on one surface of the substrate and wound in a spiral shape over a plurality of turns, and the first coil pattern has the innermost circumference. The innermost turn, the outermost turn located on the outermost periphery, the intermediate turn having the intermediate number of turns counted from the innermost turn or the outermost turn, and the center position of the track length. However, 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 the total or average value of the pattern widths of each turn from the innermost turn to the intermediate turn Is characterized in that the total value or the average value of the pattern widths of each turn from the outermost turn to the intermediate turn is larger.

  According to the present invention, since the pattern width of the innermost turn and the pattern width of the outermost turn are reduced, it is possible to reduce the loss due to the influence of the magnetic field. Moreover, the total value or average value of the pattern widths of each turn from the outermost turn to the intermediate turn is larger than the total value or average value of the pattern widths of each turn from the innermost turn to the intermediate turn. Further, the loss on the inner peripheral side that is more strongly affected by the magnetic field is further reduced. For this reason, it is possible to further reduce the AC resistance without making the pattern width narrower than necessary compared to the case where the pattern width of the coil pattern is simply symmetric between the inner peripheral side and the outer peripheral side.

  In the present invention, the pattern width at the center position may be larger than the pattern width of the intermediate turn. According to this, since the pattern width of the portion where the influence of the magnetic field is small is enlarged, it is possible to reduce the direct current resistance while reducing the loss due to the influence of the magnetic field.

  In the present invention, the pattern width of the innermost turn may be smaller than the pattern width of the outermost turn. According to this, it is possible to further reduce the loss in the innermost turn that is most strongly affected by the magnetic field.

  In the present invention, the space between the radially adjacent turns may be a constant width. According to this, since a sufficient pattern width can be secured, the direct current resistance can be reduced.

  In the present invention, the pitch in the radial direction of a plurality of turns may be constant. This makes it possible to obtain the same inductance as when the pattern width is constant.

  In the present invention, the pattern width of the innermost turn may be larger than the pattern thickness of the first coil pattern. According to this, the effect of reducing the loss by narrowing the pattern width of the innermost peripheral turn becomes remarkable.

  In the present invention, the pattern thickness of the innermost turn may be thinner than the pattern thickness of the outermost turn. Also in this case, the effect of reducing the loss by reducing the pattern width of the innermost turn is significant.

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

  The coil component according to the present invention further includes a second coil pattern formed on the other surface of the substrate and wound in a spiral shape over a plurality of turns, and includes an inner peripheral end of the first coil pattern and a second coil pattern. The inner peripheral ends of the coil patterns are connected to each other, and the second coil pattern is counted from the innermost peripheral turn located at the innermost periphery, the outermost peripheral turn located at the outermost periphery, and the innermost peripheral turn or the outermost peripheral turn. The second coil pattern is located at the center position more than the pattern width of the innermost turn and the pattern width of the outermost turn. The pattern width is larger, and the pattern width of each turn from the outermost turn to the middle turn is greater than the total or average of the pattern widths of each turn from the innermost turn to the middle turn. It may be greater towards the value or average value. According to this, since the coil pattern is formed on both surfaces of the substrate, the total number of turns can be increased.

  In the present invention, each turn constituting the second coil pattern is composed of a plurality of conductor patterns including third and fourth conductor patterns separated in the radial direction by spiral slits, and the first conductor pattern is The third conductor pattern is positioned on the outer peripheral side of the fourth conductor pattern, and the third conductor pattern is positioned on the outer peripheral side of the fourth conductor pattern. The inner peripheral ends 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, since the current density distribution of the conductor pattern located on the inner peripheral side and the conductor pattern located on the outer peripheral side is made more uniform, the direct current resistance and the alternating current resistance can be further reduced.

  The coil component according to the present invention may further include a magnetic sheet that overlaps the first coil pattern in plan view. According to this, the inductance can be increased.

  A wireless power transmission circuit according to the present invention includes the above-described coil component and a resonance circuit connected to the coil component, and the pattern thickness of the first coil pattern is at the resonance frequency of the current flowing through the first coil pattern. It is characterized by being smaller than the skin depth. According to the present invention, since the pattern thickness of the first coil pattern is smaller than the skin depth, the effect of reducing the loss by narrowing the pattern width of the innermost turn and the outermost turn becomes remarkable. Thereby, it can be preferably used as a power transmission side circuit or a power reception side circuit of the wireless power transmission system.

  As described above, according to the present invention, loss due to the influence of a magnetic field is more effectively reduced, and therefore, a coil component with reduced AC resistance and a wireless power transmission circuit including the coil component are provided. Is possible.

FIG. 1 is a schematic plan view for explaining the pattern shape of the first coil pattern 100 included in the coil component 1 according to the first embodiment of the present invention. FIG. 2 is a schematic plan view for explaining the pattern shape of the second coil pattern 200 included in the coil component 1 according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view along the line DD shown in FIGS. 1 and 2. FIG. 4 is an equivalent circuit diagram of the coil component 1. FIG. 5 is a graph for explaining a first example showing the relationship between the radial position of the conductor pattern and the pattern width. FIG. 6 is a schematic cross-sectional view for explaining the definition of the intermediate turn when the total number of turns is an odd number. FIG. 7 is a schematic cross-sectional view for explaining the definition of the intermediate turn when the total number of turns is an even number. FIG. 8 is a schematic plan view for explaining the definition of the intermediate turn when the total number of turns is an even number. FIG. 9 is a schematic plan view for explaining the definition of the intermediate turn when the total number of turns is an odd number. FIG. 10 is a schematic cross-sectional view of a coil component according to a modification. FIG. 11 is a graph for explaining a second example showing the relationship between the radial position of the conductor pattern and the pattern width. FIG. 12 is a graph for explaining a third example showing the relationship between the radial position of the conductor pattern and the pattern width. FIG. 13 is a graph for explaining a fourth example showing the relationship between the radial position of the conductor pattern and the pattern width. FIG. 14 is a graph for explaining a fifth example showing the relationship between the radial position of the conductor pattern and the pattern width. FIG. 15 is a block diagram of a wireless power transmission system using the coil component 1. FIG. 16 is an equivalent circuit diagram when two coil components 1 are connected in parallel. FIG. 17 is a schematic plan view for explaining the pattern shape of the first coil pattern 300 included in the coil component 2 according to the second embodiment of the present invention. FIG. 18 is a schematic plan view for explaining the pattern shape of the second coil pattern 400 included in the coil component 2 according to the second embodiment of the present invention. FIG. 19 is an equivalent circuit diagram of the coil component 2. FIG. 20 is a table showing simulation conditions of the example. FIG. 21 is a table showing the simulation results of the example.

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

<First Embodiment>
1 and 2 are schematic plan views for explaining pattern shapes of the first coil pattern 100 and the second coil pattern 200 included in the coil component 1 according to the first embodiment of the present invention, respectively. FIG. 3 is a schematic cross-sectional view taken along the line DD shown in FIGS. 1 and 2.

  As shown in FIG. 3, the coil component 1 according to the present embodiment is formed on the substrate 10, the first coil pattern 100 formed on one surface 11 of the substrate 10, and the other surface 12 of the substrate 10. 2nd coil pattern 200 is provided. Although it does not specifically limit about the material of the board | substrate 10, Transparent or semi-transparent flexible materials, such as PET resin, can be used. The substrate 10 may be a flexible substrate in which a glass cloth is impregnated with an epoxy resin.

  As shown in FIG. 1, the first coil pattern 100 is constituted by a planar conductor wound in a spiral shape over a plurality of turns. In the example shown in FIG. 1, the first coil pattern 100 has a five-turn configuration including turns 110 to 150, the turn 110 forms the outermost turn, and the turn 150 forms the innermost turn. Each turn 110 to 150 is divided into four in the radial direction by three spiral slits. Accordingly, the turn 110 is divided into conductor patterns 111 to 114, the turn 120 is divided into conductor patterns 121 to 124, the turn 130 is divided into conductor patterns 131 to 134, and the turn 140 is divided into conductor patterns 141 to 144. The turn 150 is divided into conductor patterns 151 to 154. Accordingly, when viewed in divided conductor pattern units, the conductor pattern 111 constitutes the outermost periphery turn, and the conductor pattern 154 constitutes the innermost periphery turn.

  The conductor patterns 111 to 114 of the turn 110 located on the outermost periphery are connected to the terminal electrode E1a via a lead pattern 161 extending in the radial direction. In addition, a drawing pattern 162 extending in the radial direction is provided at a position adjacent to the drawing pattern 161 in the circumferential direction, and a tip portion thereof is connected to the terminal electrode E2b. On the other hand, the inner peripheral ends of the conductor patterns 151 to 154 of the turn 150 located on the innermost periphery are connected to the through-hole conductors H1 to H4, respectively.

  Each of the turns 110 to 150 constituting the first coil pattern 100 has a circumferential area A1 in which the 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. 1, in the present 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 161 and the lead pattern 162 is drawn, the transition region B1 is located on the virtual line L1. ing. Further, the through-hole conductor H1 and the through-hole conductor H4 are arranged at positions that are symmetric with respect to the virtual line L1, and the through-hole conductor H2 and the through-hole conductor H3 are positions with respect to each other about the virtual line L1. Is arranged.

  As shown in FIG. 2, the second coil pattern 200 is configured by a planar conductor wound in a spiral shape over a plurality of turns. In the example illustrated in FIG. 2, the second coil pattern 200 has a five-turn configuration including the turns 210 to 250, the turn 210 forms the outermost turn, and the turn 250 forms the innermost turn. Each turn 210 to 250 is divided into four in the radial direction by three spiral slits. Accordingly, the turn 210 is divided into conductor patterns 211 to 214, the turn 220 is divided into conductor patterns 221 to 224, the turn 230 is divided into conductor patterns 231 to 234, and the turn 240 is divided into conductor patterns 241 to 244. The turn 250 is divided into conductor patterns 251 to 254. Therefore, when viewed in divided conductor pattern units, the conductor pattern 211 constitutes the outermost periphery turn, and the conductor pattern 254 constitutes the innermost periphery turn.

  The conductor patterns 211 to 214 of the turn 210 located on the outermost periphery are connected to the terminal electrode E2a via a lead pattern 261 extending in the radial direction. Further, a drawing pattern 262 extending in the radial direction is provided at a position adjacent to the drawing pattern 261 in the circumferential direction, and a tip portion thereof is connected to the terminal electrode E1b. On the other hand, the inner peripheral ends of the conductor patterns 251 to 254 of the turn 250 located on the innermost periphery are connected to the through-hole conductors H4, H3, H2, and H1, respectively.

  Each of the turns 210 to 250 constituting the second coil pattern 200 has a circumferential region A2 in which the position in the radial direction does not change and a transition region B2 in which the position in the radial direction transitions. As a boundary, five turns including turn 210 to turn 250 are defined. As shown in FIG. 2, in the present embodiment, both the outer peripheral end and the inner peripheral end of the second coil pattern 200 are located in the transition region B2. Furthermore, when a virtual line L2 extending radially from the center point C2 of the second coil pattern 200 and passing between the lead pattern 261 and the lead pattern 262 is drawn, the transition region B2 is located on the virtual line L2. ing.

  The first and second coil patterns 100 and 200 having such a configuration have one surface 11 and the other surface of the substrate 10 such that the center points C1 and C2 overlap and the virtual lines L1 and L2 overlap each other. 12 is formed. Thereby, the terminal electrodes E1a and E1b overlap and the terminal electrodes E2a and E2b overlap. The terminal electrodes E1a and E1b are short-circuited through a through-hole conductor H5 that connects the lead pattern 161 and the lead pattern 262, and are used as a single terminal electrode E1. Similarly, the terminal electrodes E2a and E2b are short-circuited through a through-hole conductor H6 that connects the lead pattern 162 and the lead pattern 261, and are used as a single terminal electrode E2.

  Furthermore, the conductor patterns 151 and 254 are short-circuited via the through-hole conductor H1, the conductor patterns 152 and 253 are short-circuited via the through-hole conductor H2, and the conductor patterns 153 and 252 are mutually short-circuited via the through-hole conductor H3. Since the conductor patterns 154 and 251 are short-circuited to each other through the through-hole conductor H4, the first coil pattern 100 and the second coil pattern 200 are connected in series as shown in FIG. A spiral coil of turns is formed.

  Although not particularly limited, as shown in FIG. 3, each conductor pattern located in the circumferential region A1 of the first coil pattern 100 and each of the conductor patterns located in the circumferential region A2 of the second coil pattern 200. The positions of the conductor patterns in the plane direction are completely the same. Thereby, since the area of the part where the board | substrate 10 is covered with a conductor pattern by planar view becomes small, it becomes possible to reduce an eddy current loss. In addition, since each conductor pattern located in the circumferential region A1 and each conductor pattern located in the circumferential region A2 overlap, visual interference between the first coil pattern 100 and the second coil pattern 200 is minimized. Can be suppressed. That is, even if the substrate 10 is transparent or translucent, the second coil pattern 200 does not become a visual obstacle when the first coil pattern 100 is visually inspected. When the visual inspection is performed, the first coil pattern 100 does not become a visual obstacle. Thereby, it is possible to correctly execute the appearance inspection using the inspection apparatus.

  Furthermore, as shown in FIG. 3, the coil component 1 according to the present embodiment has a pattern width that is not constant in the first and second coil patterns 100 and 200 but is narrow on the inner peripheral side and the outer peripheral side. The pattern width is wide on the side.

More specifically, the pattern width of the conductor patterns 154 and 254 constituting the innermost turn is W1, the pattern width of the conductor patterns 111 and 211 constituting the outermost turn is W2, and the innermost turn or the outermost turn. The conductor pattern which becomes the center position of the line length of the coil pattern along the conductor pattern 133, 233 (or 132, 232) constituting the intermediate turn whose number of turns is the middle of the whole, W3, and the conductor pattern When the pattern width of 124 and 224 is W4,
W1, W2 <W3, W4
Meet.

  The reason why the pattern widths W1 and W2 of the innermost turn and the outermost turn are reduced is that the magnetic field in this portion is strong and a large loss occurs due to heat generated by the eddy current. That is, by reducing the pattern widths W1 and W2 of the innermost turn and the outermost turn, the magnetic flux that interferes with the innermost turn and the outermost turn is reduced, so that the generated eddy current can be reduced. . It is preferable that the pattern width W1 of the innermost turn is larger than the pattern thickness of the coil patterns 100 and 200. According to this, since the eddy current flowing through the coil patterns 100 and 200 is concentrated on both sides in the radial direction of the conductor pattern, the effect of reducing the loss by narrowing the pattern width of the coil patterns 100 and 200 can be obtained remarkably. Is possible.

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

  FIG. 5 is a graph for explaining a first example showing the relationship between the radial position of the conductor pattern and the pattern width. In FIG. 5, the solid line indicates the pattern width of the coil component 1 in the present embodiment, and the broken line indicates the pattern width in the comparative example. The comparative example is an example in which the pattern width of the conductor pattern is constant.

As shown in FIG. 5, in the present embodiment, the pattern width W1 of the innermost turn is the smallest, and the pattern width is gradually or stepwise expanded from the innermost turn toward the center position of the line length. The pattern width W4 at the center position of the line length is maximized. Then, the pattern width gradually or stepwise decreases from the center position of the line length toward the outermost turn, and the pattern width becomes W2 in the outermost turn. In the example shown in FIG. 5, 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. Thereby, in this embodiment,
W1 <W2 <W3 <W4
Meet. In the comparative example, the pattern width of the conductor pattern is W0 in all turns.

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

  Here, the intermediate turns are counted from the innermost turn Ti and the outermost turn To when the number of turns of the coil pattern T is an odd number (for example, 11 turns) as shown in FIG. This corresponds to the turn T1 (for example, the sixth turn) having the same number of turns.

  Further, as shown in FIG. 7, when the number of turns of the coil pattern T is an even number (for example, 10 turns), the number of turns counted from the innermost turn Ti is the turn T2 (for example, the inner number of turns). The fifth turn counted from the peripheral end), or the turn T3 (for example, the fifth turn counted from the outer peripheral end) in which the number of turns counted from the outermost turn To corresponds to half of the total number of turns corresponds. When the number of turns of the coil pattern T is an even number, both the turn T2 and the turn T3 may be regarded as intermediate turns, or one of them may be regarded as an intermediate turn. Further, 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. 8, the pattern width of the conductor pattern at the center position of the number of turns may be regarded as the pattern width W3 of the intermediate turn. In the example shown in FIG. 8, since the total number of turns of the coil pattern T is 4, the pattern width at the position T4, which is exactly the second turn counted from the inner peripheral end or the outer peripheral end, is the pattern width W3 of the intermediate turn. You can consider it. The same applies to the case where the total number of turns is an odd number. As shown in FIG. 9, if the total number of turns of the coil pattern T is 5, then the number of turns is exactly 2. The pattern width at the position T5 corresponding to the fifth turn 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 one turn is divided into a plurality of conductor patterns, the intermediate turns may be specified based on the number of conductor patterns (20 in the example shown in FIG. 3) appearing in the cross section.

  As for the center position of the track length, if each turn is not radially divided by a spiral slit, that is, if the coil pattern is a simple spiral pattern, it is exactly the middle of the coil length along the coil pattern. This is the case. On the other hand, when each turn is divided in the radial direction by a spiral slit as in this embodiment, the entire conductor pattern is a simple spiral pattern that can be drawn with one stroke from the inner peripheral edge to the outer peripheral edge. In the case where it is assumed that there is, the middle position of the coil length along the coil pattern corresponds to the center position of the line length. That is, in the example shown in FIG. 1, a total of 20 conductor patterns composed of the conductor patterns 111 to 114, 121 to 124, 131 to 134, 141 to 144, 151 to 154 are connected in a spiral shape. This corresponds to the center position of the line length when it is assumed that the number of turns is 20 turns.

  As described above, the coil component according to the present embodiment designs the pattern width of the coil pattern in accordance with the strength of the magnetic field, and therefore, when the pattern width of the coil pattern is simply symmetric between the inner peripheral side and the outer peripheral side. As compared with the above, it is possible to further reduce the AC resistance.

  In addition, since the coil component according to the present embodiment is divided into four in the radial direction by the spiral slits, the current density bias is reduced as compared with the case where no such slits are provided. As a result, direct current resistance and alternating current resistance can be reduced. Moreover, since the radial positions of the conductor portions are completely interchanged between the first coil pattern 100 and the second coil pattern 200, the difference between the inner and outer circumferences is canceled out. Thereby, since the current density distribution is made uniform, the direct current resistance and the alternating current resistance can be further reduced.

  Further, in the present embodiment, as shown in FIG. 3, the space S between the turns adjacent in the radial direction is a constant width. As a result, there is no useless space in the vicinity of the inner peripheral end or the outer peripheral end having a narrow pattern width, so that a sufficient pattern width can be secured and the direct current resistance is 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. 10, the pitch P in the radial direction of each conductor pattern is constant, so that the space S is larger as the pattern width is narrower, and the space S is smaller as the pattern width is wider. According to this, it is possible to obtain the same inductance as when the pattern width is constant.

FIG. 11 is a graph for explaining a second example showing the relationship between the radial position of the conductor pattern and the pattern width. In the example shown in FIG. 11, the pattern width W1 of the innermost turn and the pattern width W2 of the outermost turn are the same. As this example illustrates, in the present invention, it is not essential that the pattern width W1 of the innermost turn is narrower than the pattern width W2 of the outermost turn. That means
W1 = W2
It does not matter.

  FIG. 12 is a graph for explaining a third example showing the relationship between the radial position of the conductor pattern and the pattern width. In the example shown in FIG. 12, the pattern width W1 of the innermost turn and the pattern width W2 of the outermost turn are the same, and this pattern width is maintained over a plurality of turns. As illustrated in this example, in the present invention, a conductor pattern having a minimum pattern width may be continuous over a plurality of turns.

  FIG. 13 is a graph for explaining a fourth example showing the relationship between the radial position of the conductor pattern and the pattern width. In the example shown in FIG. 13, the same pattern width as the pattern width W4 at the center of the line length is maintained over a plurality of turns. As this example illustrates, in the present invention, the conductor pattern having the maximum pattern width may be continuous over a plurality of turns.

FIG. 14 is a graph for explaining a fifth example showing the relationship between the radial position of the conductor pattern and the pattern width. In the example shown in FIG. 14, the same pattern width as the pattern width W4 at the center of the line length is maintained over a plurality of turns including intermediate turns. As this example illustrates, in the present invention, the conductor pattern having the maximum pattern width may include an intermediate turn. That means
W3 = W4
It does not matter.

  The coil component 1 according to the present embodiment can be applied to the wireless power transmission system shown in FIG. The wireless power transmission system illustrated in FIG. 15 is a system including a wireless power transmission device TX and a wireless power reception device RX, and via a space 40, a power transmission coil 21 included in the wireless power transmission device TX and a power reception included in the wireless power reception device RX. By making the coils 31 face each other, power can be transmitted wirelessly. The power transmission coil 21 is connected to a power transmission circuit 22 including a power supply circuit, an inverter circuit, a resonance circuit, and the like, and an alternating current is supplied from the power transmission circuit 22. The power receiving coil 31 is connected to a power receiving circuit 32 including a resonance circuit, a rectifier circuit, a smoothing circuit, and the like. If the power transmission coil 21 and the power reception coil 31 are faced to each other and magnetically coupled to each other, power can be transmitted wirelessly 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 component 1 according to the present embodiment can be used as the power transmission coil 21 and the power reception coil 31. In this case, the magnetic sheet 23 is preferably disposed on the opposite side of the space 40 as viewed from the power transmission coil 21, and the magnetic sheet 33 is preferably disposed on the opposite side of the space 40 as viewed from the power receiving coil 31. . If the magnetic sheets 23 and 33 are disposed, the inductance of the power transmission coil 21 and the power reception coil 31 can be increased, and more efficient power transmission can be performed. Note that when the magnetic sheet 23 or the magnetic sheet 33 is used, the magnetic field of the power transmission coil 21 or the power reception coil 31 is increased, so that the increase in the AC resistance of the power transmission coil 21 or the power reception coil 31 due to the influence of the magnetic field becomes significant. By applying the coil component 1 according to the form to the power transmission coil 21 and the power reception coil 31, the AC resistance can be efficiently reduced.

  Here, when the angular frequency of the current flowing through the power transmission coil 21 and the power reception coil 31 is ω, the electrical resistivity of the coil patterns 100 and 200 is ρ, and the absolute permeability of the coil patterns 100 and 200 is μ, the coil pattern 100, The skin depth d of the current flowing through 200 can be expressed by the following equation. The angular frequency ω can be expressed by 2πf, where f is the resonance frequency.

  In this case, the pattern thickness of the coil patterns 100 and 200 is preferably smaller than the skin depth d. When the pattern thickness of the coil patterns 100 and 200 is smaller than the skin depth d, eddy currents flowing through the coil patterns 100 and 200 are concentrated on both sides in the radial direction of the conductor pattern. For this reason, the effect of reducing the loss by narrowing the pattern width of the coil patterns 100 and 200 becomes remarkable. As an example, when the resonance frequency is 100 kHz, the skin depth d of the copper line coil is about 0.2 mm. In this case, the pattern thickness of the coil patterns 100 and 200 is less than 0.2 mm, for example, about 50 to 100 μm. If so, it is possible to obtain a significant loss reduction effect by narrowing the pattern width.

  Further, when the two coil patterns 100 and 200 are insufficient in reducing the necessary AC resistance, a plurality of coil components 1 according to the present embodiment (two in the example shown in FIG. 16) are used as shown in FIG. By connecting in parallel, the AC resistance can be further reduced. It should be noted that even when a plurality of general pattern coils are connected in parallel, the loss caused by the influence of the magnetic field also increases, so it is difficult to effectively reduce the AC resistance value. However, in the coil according to the present invention, Since the loss resulting from the influence of the magnetic field can be reduced, the AC resistance reduction effect becomes more prominent when a plurality of devices are connected in parallel.

<Second Embodiment>
17 and 18 are schematic plan views for explaining pattern shapes of the first coil pattern 300 and the second coil pattern 400 included in the coil component 2 according to the second embodiment of the present invention, respectively.

  As shown in FIG. 17, in the first coil pattern 300, conductor patterns 361 and 362 are added to the first coil pattern 100 shown in FIG. 1, and through-hole conductors are respectively formed at the inner peripheral ends of the conductor patterns 361 and 362. It has a configuration in which H7 and H8 are provided. The conductor pattern 361 is a one-turn conductor pattern continuous from the conductor pattern 151, and the conductor pattern 362 is a one-turn conductor pattern continuous from the conductor pattern 152. In the present embodiment, the through-hole conductor H3 and the through-hole conductor H8 are arranged at positions that are symmetric with respect to the virtual line L1, and the through-hole conductor H4 and the through-hole conductor H7 are symmetric with respect to the virtual line L1. It is arranged at the position. The other basic configuration is the same as that of the first coil pattern 100 shown in FIG.

  As shown in FIG. 18, in the second coil pattern 400, conductor patterns 461 and 462 are added to the second coil pattern 200 shown in FIG. 2, and through-hole conductors are respectively formed at the inner peripheral ends of the conductor patterns 461 and 462. It has a configuration in which H4 and H3 are provided. The conductor pattern 461 is a one-turn conductor pattern continuous from the conductor pattern 251, and the conductor pattern 462 is a one-turn conductor pattern continuous from the conductor pattern 252. The inner peripheral ends of the conductor patterns 253 and 254 are connected to the through-hole conductors H8 and H7, respectively. Since the other basic configuration is the same as that of the second coil pattern 200 shown in FIG. 2, the same components are denoted by the same reference numerals, and redundant description is omitted.

  The first and second coil patterns 300 and 400 having such a configuration have one surface 11 and the other surface of the substrate 10 such that the center points C1 and C2 overlap and the virtual lines L1 and L2 overlap each other. 12 is formed. As a result, the conductor patterns 153 and 462 are short-circuited through the through-hole conductor H3, the conductor patterns 154 and 461 are short-circuited through the through-hole conductor H4, and the conductor patterns 361 and 254 are connected through the through-hole conductor H7. Since the conductor patterns 362 and 253 are short-circuited to each other through the through-hole conductor H8, the first coil pattern 300 and the second coil pattern 400 are connected in series as shown in FIG. An 11-turn spiral coil is formed.

  As described above, in the present embodiment, it is possible to realize an odd-turn spiral coil, although the same pattern shape is used on both sides.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in each of the above embodiments, each turn constituting the coil pattern is separated into four conductor patterns by a spiral slit. In the present invention, each turn constituting the coil pattern is divided into a plurality of conductor patterns. It is not essential to separate. Moreover, even if it is a case where it isolate | separates into a some conductor pattern, the number is not limited to four.

  Assuming three coil parts (Example 1, Example 2 and Comparative Example) having the same structure (5 turns × 4 divisions) as the coil part 1 according to the first embodiment, the resonance frequency is 100 kHz by simulation. In this case, the AC resistance and inductance were calculated. The material of the conductor pattern was copper (Cu), and the pattern width, pattern thickness, and space in each sample were as shown in FIG. In FIG. 20, Turn1 is the outermost turn, and Turn20 is the innermost turn. The coil pattern had an inner diameter of 10.285 mm and an outer diameter of 23.63 mm.

  The simulation results are shown in FIG. As shown in FIG. 21, the samples of Examples 1 and 2 had a lower AC resistance value than the sample of the comparative example. In particular, it was confirmed that the AC resistance value in the sample of Example 1 was significantly improved as compared with the sample of the comparative example. On the other hand, regarding the inductance, the sample of Example 2 and the sample of the comparative example had the same value.

DESCRIPTION OF SYMBOLS 1, 2 Coil components 10 Board | substrate 11 One surface 12 of a board | substrate The other surface 21 of a board | substrate Power transmission coil 22 Power transmission circuit 23 Magnetic sheet 31 Power reception coil 32 Power reception circuit 33 Magnetic sheet 40 Space 100,300 1st coil pattern 200,400 Second coil patterns 110 to 150, 210 to 250 turns 111 to 114, 121 to 124, 131 to 134, 141 to 144, 151 to 154, 211 to 214, 221 to 224, 231 to 234, 241 to 244, 251 254, 361, 362, 461, 642 Conductor pattern 161, 162, 261, 262 Lead pattern A1, A2 Circumferential region B1, B2 Transition region C1, C2 Center point E1, E1a, E1b, E2, E2a, E2b Terminal electrode F1, F2 regions H1-H8 through-hole conductor L1, L2 Virtual line P Pitch RX Wireless power receiving device S Space T Coil pattern TX Wireless power transmitting device Ti Innermost turn To Outermost turn W1-W4 Pattern width

Claims (12)

A substrate,
A first coil pattern formed on one surface of the substrate and spirally wound over a plurality of turns, and
The first coil pattern has an innermost turn located on the innermost circumference, an outermost circumference turn located on the outermost circumference, and the number of turns counted from the innermost turn or the outermost turn in the middle. Having an intermediate turn and the center position of the track length,
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,
The total value or average value of the pattern widths of each turn from the outermost turn to the intermediate turn is greater than the total value or average value of the pattern widths of each turn from the innermost turn to the intermediate turn. Coil parts characterized by that.   The coil component according to claim 1, wherein a pattern width at the center position is larger than a pattern width of the intermediate turn.   The coil component according to claim 1 or 2, wherein a pattern width of the innermost turn is smaller than a pattern width of the outermost turn.   The coil component according to any one of claims 1 to 3, wherein a space between turns adjacent in the radial direction has a constant width.   The coil component according to any one of claims 1 to 3, wherein a pitch in a radial direction of the plurality of turns is constant.   The coil component according to any one of claims 1 to 5, wherein a pattern width of the innermost turn is larger than a pattern thickness of the first coil pattern.   The coil component according to any one of claims 1 to 6, wherein a pattern thickness of the innermost peripheral turn is thinner than a pattern thickness of the outermost peripheral turn.   8. Each turn constituting the first coil pattern is composed of a plurality of conductor patterns including first and second conductor patterns separated in a radial direction by a spiral slit. The coil component according to any one of the above. A second coil pattern formed on the other surface of the substrate and spirally wound over a plurality of turns;
The inner peripheral end of the first coil pattern and the inner peripheral end of the second coil pattern are connected to each other,
The second coil pattern has an innermost turn located on the innermost circumference, an outermost turn located on the outermost circumference, and the number of turns counted from the innermost turn or the outermost turn in the middle. Having an intermediate turn and the center position of the track length,
The second coil pattern has a pattern width at the center position larger than a pattern width of the innermost turn and a pattern width of the outermost turn, and from the innermost turn to the intermediate turn. The total value or the average value of the pattern widths of the respective turns from the outermost turn to the intermediate turn is larger than the total value or the average value of the pattern widths of the respective turns. Coil parts. Each turn constituting the second coil pattern is composed of a plurality of conductor patterns including third and fourth conductor patterns separated in a radial direction by a spiral slit,
The first conductor pattern is located on the outer peripheral side than the second conductor pattern,
The third conductor pattern is located on the outer peripheral side than the fourth conductor pattern,
An inner peripheral end of the first conductor pattern and an inner peripheral end of the fourth conductor pattern are connected to each other,
The coil component according to claim 9, wherein an inner peripheral end of the second conductor pattern and an inner peripheral end of the third conductor pattern are connected to each other.   The coil component according to any one of claims 1 to 10, further comprising a magnetic sheet overlapping the first coil pattern in plan view. A coil component according to any one of claims 1 to 11, and a resonance circuit connected to the coil component,
A wireless power transmission circuit, wherein a pattern thickness of the first coil pattern is smaller than a skin depth at a resonance frequency of a current flowing through the first coil pattern.

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