JP2019192691A - Coil component - Google Patents

Abstract

To improve AC resistance by reducing a loss caused by an influence of a magnetic field.SOLUTION: A coil component comprises: a coil pattern 100 formed on a surface 11 of a flat plate part 10, and wound in a spiral shape over a plurality of turns with a cylindrical part 20 as a center; and a coil pattern 200 formed on an outer peripheral surface 21 of the cylindrical part 20, and wound in a helical shape over the plurality of turns with the axis of the cylindrical part 20 as a center. A visible width viewed from a z direction of the coil pattern 200 is thinner than that viewed from the z direction of the coil pattern 100. According to the present invention, since the invention provides the coil pattern 200 wound in the helical shape, an inner diameter region of the coil pattern 100 can be enlarged. Further, since the coil pattern 200 has a thin visible width viewed from the z direction, a magnetic field in the z direction is hardly received. Thus, the coil component with low AC resistance can be provided.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.

  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 peripheral side and the outer peripheral side are strongly affected by the magnetic field, as described in Patent Document 1, if the pattern width in this portion is narrowed, the AC resistance caused by the magnetic field effect is reduced. It is possible to reduce the increase in

  However, when the pattern width of the conductor pattern located on the inner peripheral side and the outer peripheral side is too thin, there is a problem that the direct current resistance increases. In order to solve this problem, as described in Patent Document 2, a method of winding a conductor helically around the inner peripheral portion of the coil pattern is conceivable.

JP-A-11-040438 Japanese Patent Laid-Open No. 2007-221652

  However, the coil component described in Patent Document 2 is not a coil component of a type in which a conductor pattern is formed on a substrate, but a coil component of a type in which a wire (coated conductor) is wound around a bulk magnetic core. Since the wire used for such a coil component has a circular cross section, there is a problem that even a helically wound portion is easily affected by a magnetic field along the axial direction of the coil pattern.

  Therefore, an object of the present invention is to provide a coil component that can improve AC resistance by further reducing loss due to the influence of a magnetic field.

  The coil component according to the present invention is formed on a flat plate portion and a substrate having a cylindrical portion protruding from the flat plate portion and one surface of the flat plate portion, and is wound in a spiral shape over a plurality of turns around the cylindrical portion. A first coil pattern and a second coil pattern formed on one of the inner peripheral surface and the outer peripheral surface of the cylindrical portion and helically wound over a plurality of turns around the axis of the cylindrical portion; The conductor pattern constituting the second coil pattern is narrower than the conductor pattern constituting the first coil pattern when viewed from the direction perpendicular to the one surface of the flat plate portion. .

  According to the present invention, since the second coil pattern wound helically is provided, the inner diameter region of the first coil pattern wound spirally is secured while ensuring the total number of turns. Can be enlarged. Moreover, since the conductor pattern constituting the second coil pattern is thinner than the conductor pattern constituting the first coil pattern in plan view, the second coil pattern is unlikely to receive a magnetic field along the axial direction. Thereby, since the loss resulting from the influence of a magnetic field is reduced, it becomes possible to provide a coil component with a low AC resistance.

  In the present invention, the conductor pattern constituting the first coil pattern has a pattern width parallel to one surface of the flat plate portion larger than a pattern thickness perpendicular to the one surface of the flat plate portion, and the second coil The conductor pattern constituting the pattern has a pattern width parallel to one of the inner peripheral surface and the outer peripheral surface of the cylindrical portion that is greater than the pattern thickness perpendicular to one of the inner peripheral surface and the outer peripheral surface of the cylindrical portion. It doesn't matter. According to this, it is possible to confirm a sufficient pattern width while reducing the loss due to the influence of the magnetic field.

  In the present invention, the first coil pattern has an innermost turn located on the innermost circumference and an outermost turn located on the outermost circumference, and the second coil pattern is located at one end in the axial direction. The lowermost turn connected to the innermost turn of the first coil pattern and the uppermost turn located at the other end in the axial direction may be used. According to this, the first coil pattern and the second coil pattern are connected in series, and both can be easily connected on the surface of the substrate.

  The coil component according to the present invention includes a third coil pattern formed on the other surface of the flat plate portion and spirally wound around the cylindrical portion over a plurality of turns, an inner peripheral surface of the cylindrical portion, A fourth coil pattern formed on the other outer peripheral surface and helically wound over a plurality of turns around the axis of the cylindrical portion may be further provided. According to this, since the total number of turns becomes larger, a larger inductance can be obtained.

  In the present invention, the third coil pattern has an innermost circumferential turn located on the innermost circumference and an outermost circumferential turn located on the outermost circumference, and the fourth coil pattern is located at one end in the axial direction. The lowermost turn connected to the innermost turn of the third coil pattern and the uppermost turn located at the other end in the axial direction, and the second coil pattern and the fourth coil pattern are connected. It does not matter. According to this, the first to fourth coil patterns are connected in series, and the third coil pattern and the fourth coil pattern can be easily connected on the surface of the substrate. Here, the uppermost turns of the second coil pattern and the fourth coil pattern may be connected to each other.

  In the present invention, the pattern width of the outermost turn and the uppermost turn may be narrower than the pattern width of any other turn constituting the first and second coil patterns. According to this, since the pattern width of the portion where the magnetic field is strong is narrow, it is possible to further reduce the loss due to the influence of the magnetic field.

  In the present invention, the first or second coil pattern includes intermediate turns in which the number of turns counted from the outermost peripheral turn or the uppermost turn is intermediate between the total number of turns of the first and second coil patterns, It has a central position of the total line length of the second coil pattern, and the pattern width at the intermediate turn and the central position may be larger than the pattern width of the outermost peripheral turn and the uppermost turn. According to this, it is possible to reduce the direct current resistance because the pattern width of the portion where the influence of the magnetic field is small is enlarged while reducing the increase in the alternating current resistance due to the loss due to the influence of the magnetic field.

  In the present invention, the total value or average value of the pattern width of each turn from the outermost turn to the intermediate turn is larger than the total value or average value of the pattern width of each turn from the uppermost turn to the intermediate turn. It doesn't matter. According to this, the loss on the inner peripheral side that is more strongly affected by the magnetic field is further reduced. For this reason, compared with the case where the pattern width of the coil pattern is simply symmetrical between the inner peripheral side and the outer peripheral side, the AC resistance can be further reduced.

  In the present invention, each turn constituting the first coil pattern is composed of a plurality of conductor patterns separated in the radial direction by a spiral slit, and each turn constituting the second coil pattern is a helical slit. It may consist of a plurality of conductor patterns separated in the axial direction. 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. Here, if the number of conductor patterns constituting each turn of the first coil pattern is the same as the number of conductor patterns constituting each turn of the second coil pattern, the innermost circumference of the first coil pattern Each conductor pattern composing the turn and each conductor pattern composing the lowermost turn of the second coil pattern can be connected to each other, thereby facilitating pattern layout and further reducing AC resistance. It becomes.

  The coil component according to the present invention may further include a first magnetic member that covers the other surface of the flat plate portion, or may further include a second magnetic member disposed in the inner diameter region of the cylindrical portion. It does not matter. According to this, the inductance can be further increased.

  As described above, the coil component according to the present invention is less susceptible to the influence of the magnetic field in the inner peripheral portion, so that the AC resistance can be further reduced as compared with the conventional coil component.

FIG. 1 is a schematic cross-sectional view for explaining the configuration of a coil component 1 according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view for explaining the pattern shape of the coil pattern 100. FIG. 3 is a schematic plan view for explaining the pattern shape of the coil pattern 300. FIG. 4 is a schematic perspective view showing the cylindrical portion 20 and the coil patterns 200 and 400 formed on the surface thereof. FIG. 5 is a development view showing the cylindrical portion 20 and the coil patterns 200 and 400 formed on the surface thereof. FIG. 6 is a schematic diagram for explaining a method of connecting the coil patterns 100, 200, 300, and 400. FIG. 7 is an equivalent circuit diagram of the coil component 1. FIG. 8 is a view for explaining the shape of the conductor pattern formed on the flat plate portion 10 and the conductor pattern formed on the tubular portion 20. FIG. 9 is a schematic cross-sectional view along the line DD shown in FIGS. 2 and 3. FIG. 10 is a graph for explaining the relationship between the radial position and axial position of the conductor pattern and the pattern width. FIG. 11 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. 12 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. 13 is a schematic plan view for explaining the definition of the intermediate turn when the total number of turns is an even number. FIG. 14 is a schematic plan view for explaining the definition of the intermediate turn when the total number of turns is an odd number. FIG. 15 is a schematic cross-sectional view of a coil unit according to a modification. FIG. 16 is a block diagram of a wireless power transmission system using the coil component 1. FIG. 17 is a schematic cross-sectional view for explaining the configuration of the coil component 2 including the coil units U1 and U2. FIG. 18 is an equivalent circuit diagram of the coil component 2. FIG. 19 is a schematic cross-sectional view for explaining the configuration of the coil component 3 according to a modification. FIG. 20 is a partially enlarged view of the coil component 3. FIG. 21 is a table showing the simulation conditions of the example. FIG. 22 is a table showing simulation results of the example.

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

  FIG. 1 is a schematic cross-sectional view for explaining the configuration of a coil component 1 according to a preferred embodiment of the present invention.

  As shown in FIG. 1, the coil component 1 according to the present embodiment includes a first magnetic member M1, a second magnetic member M2, and a coil unit U1. The magnetic members M1 and M2 are made of a high magnetic permeability material such as ferrite, permalloy, or a composite magnetic material, and function as a magnetic path of magnetic flux interlinking with the coil unit U1.

  The coil unit U1 includes a substrate having a flat plate portion 10 and a cylindrical portion 20, and first to fourth coil patterns 100, 200, 300, and 400 formed on the surface of the substrate. Specifically, the first coil pattern 100 is formed on one surface 11 of the flat plate portion 10, the second coil pattern 200 is formed on the outer peripheral surface 21 of the cylindrical portion 20, and the other surface of the flat plate portion 10. 12, a third coil pattern 300 is formed, and a fourth coil pattern 400 is formed on the inner peripheral surface 22 of the cylindrical portion 20. The material of the substrate formed of the flat plate portion 10 and the cylindrical portion 20 is not particularly limited, but a transparent or translucent flexible material such as PET resin can be used. The flat plate portion 10 and the cylindrical portion 20 may be a flexible substrate in which a glass cloth is impregnated with an epoxy resin. The flat plate portion 10 and the cylindrical portion 20 may be separate members or may be integrated.

  As for the flat plate part 10 of the board | substrate, the surfaces 11 and 12 comprise the xy plane. On the other hand, the cylindrical portion 20 of the substrate protrudes from the flat plate portion 10 in the z direction. The axial direction of the cylindrical portion 20 is also the z direction, whereby the outer peripheral surface 21 and the inner peripheral surface 22 of the cylindrical portion 20 have an angle of 90 ° with respect to the surfaces 11 and 12 of the flat plate portion 10. Yes. The first and third coil patterns 100 and 300 are spirally wound over a plurality of turns around the cylindrical portion 20, and the second and fourth coil patterns 200 and 400 include the cylindrical portion. It is wound helically over a plurality of turns around the axis. The first magnetic member M <b> 1 is disposed so as to cover the other surface 12 of the flat plate portion 10, and the second magnetic member M <b> 21 is disposed in the inner diameter region of the cylindrical portion 20. In the present invention, it is not essential to provide the magnetic members M1 and M2, but the inductance can be increased by providing the magnetic members M1 and M2.

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

  As shown in FIG. 2, the first coil pattern 100 is constituted by a planar conductor wound in a spiral shape over a plurality of turns. In the example illustrated in FIG. 2, the first coil pattern 100 has a four-turn configuration including the turns 110 to 140, the turn 110 forms the outermost turn, and the turn 140 forms the innermost turn. Each of the turns 110 to 140 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 Accordingly, when viewed in divided conductor pattern units, the conductor pattern 111 constitutes the outermost periphery turn, and the conductor pattern 144 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 171 extending in the radial direction. Further, a drawing pattern 172 extending in the radial direction is provided at a position adjacent to the drawing pattern 171 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 141 to 144 of the turn 140 located on the innermost periphery constitute connection nodes N11 to N14, respectively.

  Each of the turns 110 to 140 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. Four turns consisting of turns 110 to 140 are defined as boundaries. As shown in FIG. 2, 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. Further, 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 located on the virtual line L1. ing. Further, the connection node N11 and the connection node N14 are arranged at positions that are symmetric with respect to the virtual line L1, and the connection node N12 and the connection node N13 are arranged at positions that are symmetric with respect to the virtual line L1. Yes.

  As shown in FIG. 3, the third coil pattern 300 is configured by a planar conductor wound in a spiral shape over a plurality of turns. In the example shown in FIG. 3, the third coil pattern 300 has a four-turn configuration including the turns 310 to 340, the turn 310 forms the outermost turn, and the turn 340 forms the innermost turn. Each turn 310 to 340 is divided into four in the radial direction by three spiral slits. Accordingly, the turn 310 is divided into conductor patterns 311 to 314, the turn 320 is divided into conductor patterns 321 to 324, the turn 330 is divided into conductor patterns 331 to 334, and the turn 340 is divided into conductor patterns 341 to 344. The Accordingly, when viewed in divided conductor pattern units, the conductor pattern 311 constitutes the outermost periphery turn, and the conductor pattern 344 constitutes the innermost periphery turn.

  The conductor patterns 311 to 314 of the turn 310 located on the outermost periphery are connected to the terminal electrode E2a via a lead pattern 371 extending in the radial direction. In addition, a drawing pattern 372 extending in the radial direction is provided at a position adjacent to the drawing pattern 371 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 341 to 344 of the turn 340 located on the innermost periphery constitute connection nodes N34, N33, N32, and N31, respectively.

  Each of the turns 310 to 340 constituting the third coil pattern 300 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. Four turns including a turn 310 to a turn 340 are defined as boundaries. As shown in FIG. 3, in the present embodiment, the outer peripheral end and the inner peripheral end of the third coil pattern 300 are both located in the transition region B2. Further, 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 located on the virtual line L2. ing. Further, the connection node N31 and the connection node N34 are arranged at positions that are symmetric with respect to the virtual line L2, and the connection node N32 and the connection node N33 are arranged at positions that are symmetric with respect to the virtual line L2. Yes.

  The first and third coil patterns 100 and 300 having such a configuration are arranged so that the center points C1 and C2 overlap and the virtual lines L1 and L2 overlap, respectively, the one surface 11 and the other of the flat plate portion 10. Formed on the surface 12. 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 T5 connecting 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 through a through-hole conductor T6 connecting the lead pattern 172 and the lead pattern 371, and used as a single terminal electrode E2.

  4 and 5 are a schematic perspective view and a developed view showing the cylindrical portion 20 and coil patterns 200 and 400 formed on the surface thereof, respectively.

  As shown in FIGS. 4 and 5, the second coil pattern 200 formed on the outer peripheral surface 21 of the cylindrical portion 20 is constituted by a planar conductor wound helically over a plurality of turns. In the example shown in FIGS. 4 and 5, the second coil pattern 200 includes turns 210 and is divided into four in the axial direction by three spiral slits. Thereby, the turn 210 is divided into conductor patterns 211 to 214. Of these, the lowermost conductor pattern 214 constitutes the lowermost turn, and the uppermost conductor pattern 211 constitutes the uppermost turn.

  End portions below the conductor patterns 211 to 214 constitute connection nodes N21 to N24, respectively. Connection nodes N21 to N24 are connected to connection nodes N11 to N14 included in first coil pattern 100, respectively. The connection between the connection nodes N11 to N14 and the connection nodes N21 to N24 can be made on the surface 11 of the flat plate portion 10 and the outer peripheral surface 21 of the cylindrical portion 20 as shown in FIG. On the other hand, the upper end portions of the conductor patterns 211 to 214 are connected to through-hole conductors H1 to H4 provided so as to penetrate the cylindrical portion 20, respectively.

  The 4th coil pattern 400 formed in the inner peripheral surface 22 of the cylindrical part 20 is comprised by the planar conductor wound helically over multiple turns. In the example shown in FIGS. 4 and 5, the fourth coil pattern 400 includes a turn 410, and is divided into four in the axial direction by three spiral slits. Thereby, the turn 410 is divided into conductor patterns 411 to 414. Among these, the lowermost conductor pattern 411 constitutes the lowermost turn, and the uppermost conductor pattern 414 constitutes the uppermost turn.

  End portions below the conductor patterns 411 to 414 constitute connection nodes N41 to N44, respectively. The connection nodes N41 to N44 are located on the back side of the connection nodes N21 to N24, respectively, and in FIG. 4 and FIG. Connection nodes N41 to N44 are connected to connection nodes N31 to N34 included in third coil pattern 300, respectively. The connection between the connection nodes N31 to N34 and the connection nodes N41 to N44 can be made on the surface 12 of the flat plate portion 10 and the inner peripheral surface 22 of the cylindrical portion 20 as shown in FIG. On the other hand, the upper ends of the conductor patterns 411 to 414 are connected to the through-hole conductors H1 to H4, respectively.

  As a result, the conductor patterns 211 and 411 are short-circuited via the through-hole conductor H1, the conductor patterns 212 and 412 are short-circuited via the through-hole conductor H2, and the conductor patterns 213 and 413 are short-circuited via the through-hole conductor H3. The conductor patterns 214 and 414 are short-circuited with each other through the through-hole conductor H4.

  Therefore, when attention is paid to the conductor pattern 141 located on the outermost side among the four conductor patterns 141 to 144 constituting the turn 140 of the first coil pattern 100, first, the second pattern is connected via the connection nodes N11 and N21. Connected to the conductor pattern 211 of the coil pattern 200, then connected to the conductor pattern 411 of the fourth coil pattern 400 via the through-hole conductor H1, and finally connected to the third via the connection nodes N41 and N31. Of the four conductor patterns 341 to 344 constituting the turn 340 of the coil pattern 300, the coil pattern 300 is connected to the conductor pattern 344 located on the innermost side.

  Further, when attention is paid to the conductor pattern 144 located on the innermost side among the four conductor patterns 141 to 144 constituting the turn 140 of the first coil pattern 100, first, the second through the connection nodes N14 and N24. Connected to the conductor pattern 214 of the coil pattern 200 of the second coil pattern, then connected to the conductor pattern 414 of the fourth coil pattern 400 via the through-hole conductor H4, and finally connected to the third conductor pattern via the connection nodes N44 and N34. Of the four conductor patterns 341 to 344 constituting the turn 340 of the coil pattern 300, the coil pattern 300 is connected to the conductor pattern 341 located on the outermost side.

  The same applies to the other conductor patterns 142 and 143 constituting the turn 140 of the first coil pattern 100, and the turn 340 of the third coil pattern 300 via the conductor patterns 212 and 412 and the conductor patterns 213 and 413, respectively. Are connected to other conductor patterns 343 and 342.

  As described above, the end of the first coil pattern 100 is connected to the end of the second coil pattern 200, and the end of the third coil pattern 300 is connected to the end of the fourth coil pattern 400. In addition, since the end portion of the second coil pattern 200 and the end portion of the fourth coil pattern 400 are connected to each other, the terminal electrode is not drawn out partway. The terminal electrode E2 with E1 can be connected in series. That is, since it is not necessary to use a lead pattern connected to a portion other than the outer peripheral ends of the coil patterns 100 and 300, an increase in thickness and deterioration of electrical characteristics due to the use of the lead pattern can be prevented.

  As a result, the first to fourth coil patterns 100, 200, 300, and 400 are connected in series as shown in FIG. 7, and a total of 10 turns × 4 parallel spiral coils are formed. Here, since the number of divisions (four divisions) of each coil pattern 100, 200, 300, 400 is the same, a plurality of conductor patterns constituting each coil pattern 100, 200, 300, 400 are re-branched or merged. These can be connected as they are. As a result, the pattern layout becomes easy and the current density is made uniform, so that the AC resistance can be further reduced.

  FIG. 8 is a view for explaining the shape of the conductor pattern formed on the flat plate portion 10 and the conductor pattern formed on the tubular portion 20.

  As shown in FIG. 8, the conductor pattern (for example, conductor pattern 142) constituting the first coil pattern 100 has a pattern width Wa larger than the pattern thickness Ha (Wa> Ha). Similarly, the conductor pattern (for example, conductor pattern 212) constituting the second coil pattern 200 has a pattern width Wb larger than the pattern thickness Hb (Wb> Hb). Here, the “pattern width” means a width in a direction parallel to the substrate. In the conductor pattern constituting the first coil pattern 100, the width in the xy direction indicates the second coil pattern 200. In the conductor pattern, the width in the z direction is indicated. “Pattern thickness” means the thickness in the direction perpendicular to the substrate, and the conductor pattern constituting the first coil pattern 100 indicates the thickness in the z direction, and constitutes the second coil pattern 200. In the conductor pattern, it refers to the thickness in the xy direction. The same applies to the third and fourth coil patterns 300 and 400.

  In the present embodiment, since the outer peripheral surface 21 and the inner peripheral surface 22 of the cylindrical portion 20 are perpendicular to the surfaces 11 and 12 of the flat plate portion 10, they are perpendicular to the surfaces 11 and 12 of the flat plate portion 10. When viewed from the direction (z direction), the direction defining the pattern width Wa is the same as the direction defining the pattern thickness Hb, and Wa> Hb. That is, the visual recognition width seen from the z direction of the conductor pattern constituting the second coil pattern 200 is narrower than the visual recognition width seen from the z direction of the conductor pattern constituting the first coil pattern 100.

  Here, when the magnetic flux φ is generated by the current flowing through the coil component 1 (or when the magnetic flux φ generated by another coil component is linked to the coil component 1), the main direction component of the magnetic flux φ is in the vicinity of the flat plate portion 10. Is the plane direction (xy direction), and in the vicinity of the cylindrical portion 20 is the vertical direction (z direction). For this reason, in a general coil component using a spiral conductor pattern, the interference between the magnetic flux φ and the conductor pattern becomes stronger at the inner peripheral portion where the z-direction component of the magnetic flux φ increases, resulting in a large loss due to heat generated by the eddy current. Will occur. On the other hand, in this embodiment, several turns located in the inner periphery of the coil component 1 are formed in the cylindrical portion 20, thereby reducing the size (Hb) of the conductor pattern viewed from the z direction. As a result, the interference between the magnetic flux φ and the conductor pattern in the inner peripheral portion can be greatly reduced, and an increase in AC resistance due to eddy current loss can be prevented. Moreover, since the pattern width Wb is sufficiently secured, the direct current resistance can be sufficiently reduced.

  As described above, in the coil component 1 according to the present embodiment, the cylindrical portion 20 is disposed on the inner peripheral portions of the first and third coil patterns 100 and 300 formed of the spiral conductor pattern, and the helical portion is formed on the surface thereof. Since the second and fourth coil patterns 200 and 400 made of the conductor pattern are formed, the interference between the magnetic flux φ and the conductor pattern is greatly reduced in the inner peripheral portion where the magnetic flux density is high and the z-direction component of the magnetic flux is large. It becomes possible to reduce. Thereby, since generation | occurrence | production of an eddy current is suppressed, it becomes possible to prevent the increase in alternating current resistance by an eddy current effectively. In addition, since the inner diameters of the first and third coil patterns 100 and 300 are enlarged as compared with a case where all the conductor patterns are spiral, it is possible to increase the inductance.

  Here, the pattern width of the first to fourth coil patterns 100, 200, 300, and 400 may be constant, but is a schematic cross-sectional view taken along the line DD shown in FIGS. As shown in FIG. 9, the pattern widths of the first to fourth coil patterns 100, 200, 300, and 400 are not constant, the pattern width is narrow on the inner peripheral side and the outer peripheral side, and the pattern width is set on the central side. You can make it wider.

More specifically, the pattern width of the conductor patterns 211 and 414 constituting the uppermost turn is counted from W1, and the pattern width of the conductor patterns 111 and 311 constituting the outermost turn is counted from W2, the uppermost turn or the outermost turn. Thus, the conductor pattern 133 constituting an intermediate turn whose number of turns is intermediate between the total number of turns of the first and second coil patterns 100 and 200 (or the total number of turns of the third and fourth coil patterns 300 and 400). , 333 (or 132,332) having a pattern width W3, the total line length of the first and second coil patterns 100, 200 along the conductor pattern (or the total line of the third and fourth coil patterns 300, 400) When the pattern width of the conductor patterns 124 and 324 at the center position is W4,
W1, W2 <W3, W4
Meet.

  The reason why the pattern widths W1 and W2 of the uppermost 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 uppermost turn and the outermost turn, the magnetic flux that interferes with the uppermost turn and the outermost turn is reduced, so that the eddy current generated can be reduced. The pattern width W1 of the uppermost turn is preferably larger than the pattern thickness. According to this, since the eddy currents flowing through the coil patterns 200 and 400 are concentrated on both sides in the axial direction of the conductor pattern, the loss reduction effect by narrowing the pattern width of the coil patterns 200 and 400 is remarkably obtained. 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. 10 is a graph for explaining the relationship between the radial position and axial position of the conductor pattern and the pattern width. In FIG. 10, the solid line shows an example in which the pattern width is changed according to the radial position and the axial position, and the broken line shows an example in which the pattern width is constant.

In the example shown by the solid line in FIG. 10, the pattern width W1 of the uppermost turn is the smallest, the pattern width gradually or stepwise increases from the uppermost turn toward the center position of the line length, The pattern width W4 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 by the solid line in FIG. 10, the pattern width W1 of the uppermost turn is smaller than the pattern width W2 of the outermost turn. This is because the uppermost turn has a stronger magnetic field than the outermost turn, and this is reflected in the pattern width. Thus, in the example shown by the solid line in FIG.
W1 <W2 <W3 <W4
Meet. On the other hand, in the example indicated by the broken line, the pattern width of the conductor pattern is W0 in all turns.

  Further, the center position of the line length is located on the outer peripheral side of the intermediate turn, and in the example indicated by the solid line, 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 example shown by the solid line, 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. As described above, in the example shown by the solid line in FIG. 10, the pattern width is not symmetric between the inner peripheral side and the outer peripheral side when the intermediate turn is considered as the center.

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

  Further, as shown in FIG. 12, 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 uppermost turn Ti is a turn T2 (for example, an inner circumference) corresponding to half of the total number of turns. The fifth turn counted from the end) or the turn T3 (for example, the fifth turn counted from the outer circumferential 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. 13, 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. 13, since the total number of turns of the coil pattern T is 4, the pattern width at the position T4 that 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. This also applies to the case where the total number of turns is an odd number, and as shown in FIG. 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 appearing in the cross section (20 in the example shown in FIG. 9).

  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. 9, a total of 20 conductor patterns consisting of the conductor patterns 111 to 114, 121 to 124, 131 to 134, 141 to 144, 211 to 214 are connected in a spiral shape or a helical shape. This corresponds to the center position of the line length when it is assumed that the total number of turns of the coil patterns 100 and 200 is 20.

  Thus, if the pattern width of the coil pattern is designed according to the strength of the magnetic field, the AC resistance can be further reduced as compared with the case where the pattern width is constant.

  In addition, the coil component according to the present embodiment is divided into four in the radial direction by a spiral or helical slit, so that the current density bias is reduced as compared with the case where such a slit is not provided. Is done. 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 third coil pattern 300, the inner and outer circumference differences are offset. Thereby, since the current density distribution is made uniform, the direct current resistance and the alternating current resistance can be further reduced.

  In the example shown in FIG. 9, the space S between turns adjacent in the radial direction or the axial direction is set to 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. 15, the pitch P in the radial direction or the axial 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. ing. According to this, it is possible to obtain the same inductance as when the pattern width is constant.

  Although not particularly limited, as shown in FIGS. 9 and 15, each conductor pattern located in the circumferential area A <b> 1 of the first coil pattern 100 and the circumferential area A <b> 2 of the third coil pattern 300. The position of each conductor pattern located in the plane direction is completely the same. As a result, the area of the portion where the flat plate portion 10 of the substrate is covered with the conductor pattern is reduced in plan view, and eddy current loss can be reduced. 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 third coil pattern 300 is minimized. Can be suppressed. That is, even if the flat plate portion 10 of the substrate is transparent or translucent, the third coil pattern 300 does not become a visual obstacle when the first coil pattern 100 is visually inspected. When the appearance inspection of the coil pattern 300 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.

  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. 16 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 51 included in the wireless power transmission device TX and a power reception included in the 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 an alternating current is supplied from the power transmission circuit 52. The power receiving coil 61 is connected to a power receiving circuit 62 including a resonance circuit, a rectifier circuit, a smoothing circuit, and the like. If the power transmission coil 51 and the power reception coil 61 are opposed to each other and magnetically coupled to 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 component 1 according to the present embodiment can be used as the power transmission coil 51 and the power reception coil 61. In this case, the magnetic member 53 disposed on the opposite side of the space 40 as viewed from the power transmission coil 51 and the magnetic member 63 disposed on the opposite side of the space 40 as viewed from the power receiving coil 61 are the magnetic member M1 illustrated in FIG. , M2. If the magnetic members 53 and 63 (magnetic members M1 and M2) are arranged, inductances of the power transmission coil 51 and the power reception coil 61 are increased, and more efficient power transmission can be performed.

  Moreover, when the allowable current value of the coil is insufficient in the first to fourth coil patterns 100, 200, 300, and 400, a plurality (two in the example shown in FIG. ) Are coaxially stacked and connected in parallel as shown in FIG. 18, the coil resistance value can be further reduced and the allowable current value of the coil can be increased. In this case, one cylindrical part 20 is inserted into the other cylindrical part 20 by providing a difference between the diameter of the cylindrical part 20 constituting the coil unit U1 and the diameter of the cylindrical part 20 constituting the coil unit U2. can do.

  Further, since the distance between the magnetic member M1 and the coil unit U2 is longer than the distance between the magnetic member M1 and the coil unit U1, even if the number of turns of the coil units U1 and U2 is the same, the inductance is equal to that of the coil unit U2. As a result, there is a difference in impedance between the coil units U1 and U2. If there is an impedance difference between the coil units U1 and U2, the loss increases due to a current bias caused by the impedance difference. Considering this point, it is preferable to increase the inductance by making the line length of the coil unit U2 having a small impedance longer than the line length of the coil unit U1. According to this, since the inductance difference between the two coil units U1 and U2 is reduced, the current bias due to the impedance difference is reduced and ideally matches. As a result, the loss of the entire circuit shown in FIG. 18 can be reduced.

  On the other hand, when the required inductance is insufficient, a plurality (two in the example shown in FIG. 17) of coil units U1 and U2 are coaxially stacked and connected in series as in the coil component 2 shown in FIG. It doesn't matter.

  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, the cylindrical portion 20 is provided perpendicular to the flat plate portion 10, but this point is not essential in the present invention. Accordingly, the angle θ formed by the flat plate portion 10 and the tubular portion 20 may be less than 90 ° as in the coil component 3 according to the modification shown in FIG. Even in this case, as shown in FIG. 20, the visual recognition width V of the second coil pattern 200 viewed from the z direction is larger than the visual recognition width Wa of the first coil pattern 100 viewed from the z direction. If it is thin, the interference between the second coil pattern 200 and the magnetic flux φ can be reduced. The visual recognition width V of the second coil pattern 200 viewed from the z direction is preferably narrower. From this viewpoint, the angle θ is preferably closer to 90. Actually, the angle θ is preferably 45 ° or more, and more preferably 60 ° or more.

  In each of the above embodiments, each turn constituting the coil pattern is separated into four conductor patterns by a spiral slit. However, 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 two coil components (Examples 1 and 2) having the same structure as the coil component 1 according to the above embodiment, the AC resistance and the inductance when the frequency is 100 kHz were calculated by simulation. In addition, a comparative example having the same configuration as that of Example 1 is assumed except that all the conductor patterns are wound in a spiral shape without using the cylindrical portion 20, and an alternating current when the frequency is 100 kHz by simulation is assumed. 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. 21, Turn1 is the outermost turn and Turn20 is the uppermost turn. Moreover, in Example 1 and 2, the diameter of the cylindrical part 20 was 22 mm. In the comparative example, the inner diameter and the outer diameter of the coil were adjusted so that the inductance values were almost the same as those in Examples 1 and 2.

  The result of the simulation is shown in FIG. As shown in FIG. 22, the samples of Examples 1 and 2 had lower AC resistance values than the samples of the comparative examples. In particular, it was confirmed that the AC resistance value in the sample of Example 2 was significantly improved as compared with the sample of the comparative example.

1-3 Coil parts 10 Flat plate portion 11, 12 Flat plate surface 20 Tubular portion 21 Tubular portion outer peripheral surface 22 Tubular portion inner peripheral surface 40 Space 51 Power transmission coil 52 Power transmission circuit 53 Magnetic member 61 Power reception coil 62 Power reception Circuit 63 Magnetic member 100 First coil pattern 200 Second coil pattern 300 Third coil pattern 400 Fourth coil patterns 110-140, 210, 310-340, 410 Turns 111-114, 121-124, 131- 134, 141-144, 211-214, 311-314, 321-324, 331-334, 341-344, 411-414 Conductor patterns 171, 172, 371, 372 Draw patterns A1, A2 Circumferential regions B1, B2 Transition Region C1, C2 Center point E1, E1a, E1b, E2, E2a, E2b F1, F2 regions H1-H4 through-hole conductors L1, L2 virtual lines M1, M2 magnetic members N11-N14, N21-N24, N31-N34, N41-N44 connection node P pitch RX wireless power receiving device S space T coil pattern TX wireless Power transmission device Ti Innermost turn To Outermost turn U1, U2 Coil units W1-W4 Pattern width θ Angle φ Magnetic flux

Claims (11)

A substrate having a flat plate portion and a cylindrical portion protruding from the flat plate portion;
A first coil pattern formed on one surface of the flat plate portion and spirally wound around the cylindrical portion over a plurality of turns;
A second coil pattern formed on one of the inner peripheral surface and the outer peripheral surface of the cylindrical part and wound helically over a plurality of turns around the axis of the cylindrical part,
The conductor pattern constituting the second coil pattern is narrower than the conductor pattern constituting the first coil pattern when viewed from a direction perpendicular to the one surface of the flat plate portion. Coil parts to play. The conductor pattern constituting the first coil pattern has a pattern width parallel to the one surface of the flat plate portion larger than a pattern thickness perpendicular to the one surface of the flat plate portion,
The conductor pattern constituting the second coil pattern has a pattern width parallel to the one of the inner peripheral surface and the outer peripheral surface of the cylindrical portion, and The coil component according to claim 1, wherein the coil component is larger than a pattern thickness perpendicular to the one. The first coil pattern has an innermost turn located on the innermost circumference and an outermost turn located on the outermost circumference.
The second coil pattern is located at one end in the axial direction, connected to the innermost turn of the first coil pattern, and an uppermost turn located at the other end in the axial direction. The coil component according to claim 1 or 2, characterized by comprising: A third coil pattern formed on the other surface of the flat plate portion and spirally wound over a plurality of turns around the cylindrical portion;
A fourth coil pattern formed on the other of the inner peripheral surface and the outer peripheral surface of the tubular portion and wound helically over a plurality of turns around the axis of the tubular portion. The coil component according to claim 3. The third coil pattern has an innermost circumferential turn located on the innermost circumference and an outermost circumferential turn located on the outermost circumference,
The fourth coil pattern is located at the one end in the axial direction, connected to the innermost turn of the third coil pattern, and an uppermost part located at the other end in the axial direction Has a turn and
The coil component according to claim 4, wherein the second coil pattern and the fourth coil pattern are connected.   6. The pattern width of the outermost turn and the uppermost turn is narrower than the pattern width of any other turn constituting the first and second coil patterns. The coil component according to claim 1. The first or second coil pattern includes an intermediate turn in which the number of turns counted from the outermost turn or the uppermost turn is intermediate between the total number of turns of the first and second coil patterns; And the center position of the total line length of the second coil pattern,
The coil component according to claim 6, wherein a pattern width at the intermediate turn and the central position is larger than a pattern width of the outermost peripheral turn and the uppermost turn.   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 uppermost turn to the intermediate turn. The coil component according to claim 7. Each turn constituting the first coil pattern is composed of a plurality of conductor patterns separated in a radial direction by spiral slits,
9. The coil component according to claim 1, wherein each turn constituting the second coil pattern includes a plurality of conductor patterns separated in an axial direction by a helical slit. .   The coil component according to any one of claims 1 to 9, further comprising a first magnetic member that covers the other surface of the flat plate portion.   The coil component according to any one of claims 1 to 10, further comprising a second magnetic member disposed in an inner diameter region of the cylindrical portion.

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