Coil Device

Abstract

To provide a coil device in which a floating capacitance is reduced.SOLUTION: A coil device 1 includes: a first wire 60; a second wire 79; and a drum core 20 that includes a winding core part 30 around which the first wire 60 and a second wire 70 are wound. The drum core includes: a first flange part 40 that is formed at one end along a first shaft of the winding core part; and a second flange part 50 that is formed at the other end along the first shaft of the winding core part. In the first flange part, a first terminal 81 and a second terminal 82 connected to the first wire are formed. In the second flange part, a third terminal 91 and a fourth terminal 92 connected to the second wire are formed. The first wire includes a first coil part of a winding width W1 wound around the winding core part, and the second wire includes a second coil part of a winding width W2 wound around the winding core part. The first coil part is arranged on the first flange part 40 side so as to be separated by a separation distance W3 from the second coil part, a relationship of W3>W1 or W3>W2 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coil device that can be used as, for example, a noise filter. [Background technology]

[0002] A noise filter having two coils on the winding core of a core has been disclosed (Patent Document 1). In this noise filter, each coil is wound on a different winding section of the winding core, which makes it easy to equalize the path lengths of each coil and makes it possible to equalize the characteristics of the two coils.

[0003] However, in such a noise filter, the lead wire from one coil is close to the other coil, which generates excess stray capacitance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Application No. 2006-261572 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coil device with reduced stray capacitance. [Means for solving the problem]

[0006] In order to achieve the above object, a coil device according to the present invention comprises: A coil device including a first wire, a second wire, and a drum core having a winding core portion around which the first wire and the second wire are wound, The drum core has a first flange portion formed at one end of the winding core portion along the first axis and a second flange portion formed at the other end of the winding core portion along the first axis, The first flange portion is formed with a first terminal and a second terminal to be connected to the first wire, a third terminal and a fourth terminal connected to the second wire are formed on the second flange; the first wire has a first coil portion wound so as to be pressed against the winding core portion, the first coil portion has a first winding width W1 defined by a component of a distance along the first axis between a first outer winding portion closest to the first flange portion and a first inner winding portion farthest from the first flange portion in the first coil portion, the second wire has a second coil portion wound so as to be pressed against the winding core portion, the second coil portion has a second winding width W2 defined by a component of a distance along the first axis between a second outer winding portion closest to the second flange portion and a second inner winding portion farthest from the second flange portion in the second coil portion, the first coil portion is disposed near the first flange portion and separated from the second coil portion by a separation distance W3 defined by a component of the distance between the first inner winding portion and the second inner winding portion in the direction along the first axis, It is characterized in that the relationship W3>W1 or W3>W2 is satisfied.

[0007] With this configuration, both ends of each wire are connected to terminals located on the flange near the coil portion, and each wire is pulled out while maintaining a sufficient distance from the coil portion formed by the other wire. Furthermore, a sufficient distance is ensured between the coil portions. By ensuring a sufficient distance between one wire and the other wire, it is possible to reduce the stray capacitance of the coil device.

[0008] Preferably, a first connection position for connecting to the first wire of the first terminal and a second connection position for connecting to the first wire of the second terminal are arranged on a first direction side along a second axis perpendicular to the first axis of the first flange portion, and a third connection position for connecting to the second wire of the third terminal and a fourth connection position for connecting to the second wire of the fourth terminal are arranged on the first direction side along the second axis of the second flange portion.

[0009] By arranging the connection position between the wire and the terminal in one direction along the second axis in this way, it becomes easier to mount on a circuit board, etc., and it also becomes easier to adopt a configuration that forms a closed magnetic circuit using a plate core, etc.

[0010] Preferably, the first connection position is located on the opposite side of the second connection position, across a connection portion where the first flange portion is connected to the winding core portion, in a third axis direction perpendicular to the first axis and the second axis, and the third connection position is located on the opposite side of the fourth connection position, across a connection portion where the second flange portion is connected to the winding core portion, in the third axis direction.

[0011] This configuration allows both ends of each wire to be pulled out away from the coil formed on the winding core on both sides in the third axis direction, thereby reducing the stray capacitance of each coil.

[0012] Preferably, the first wire is bent at a first winding end, which is one end of the first coil portion, toward the first connection position so as to move away from the first coil portion; the first wire is bent at a second winding end, which is the other end of the first coil portion, toward the second connection position so as to move away from the first coil portion; the second wire is bent at a third winding end, which is one end of the second coil portion, toward the third connection position so as to move away from the second coil portion; and the second wire is bent at a fourth winding end, which is the other end of the second coil portion, toward the fourth connection position so as to move away from the second coil portion.

[0013] By bending the wire at the winding end and drawing it out so that it is spaced apart from the coil portion in this way, a sufficient distance can be maintained between the drawing portion and the coil portion, making it possible to reduce stray capacitance.

[0014] Preferably, the first terminal is a first terminal first portion having a plane perpendicular to the second axis; and a first terminal second portion disposed on the opposite side of the first terminal first portion across the first flange portion in the second axis direction, the first terminal second portion having a plane parallel to the first terminal first portion; a first connecting portion connecting the first terminal first portion and the first terminal second portion; The second terminal is a second terminal first portion having a plane perpendicular to the second axis; and a second terminal second portion disposed on the opposite side of the second terminal first portion across the first flange portion in the second axis direction, the second terminal second portion having a plane parallel to the second terminal first portion; a second connecting portion connecting the second terminal first portion and the second terminal second portion, The third terminal is a third terminal first portion having a plane perpendicular to the second axis; and a third terminal second portion disposed on the opposite side of the third terminal first portion across the second flange portion in the third axis direction, the third terminal second portion having a plane parallel to the third terminal first portion; a third connection portion connecting the third terminal first portion and the third terminal second portion, The fourth terminal is a fourth terminal first portion having a plane perpendicular to the second axis; and a fourth terminal second portion disposed on the opposite side of the fourth terminal first portion across the second axis direction from the second flange portion, the fourth terminal second portion having a plane parallel to the fourth terminal first portion; and a fourth connection portion connecting the fourth terminal first portion and the fourth terminal second portion.

[0015] With this configuration, the terminal can grip the flange portion from both sides in the second axial direction, making it easy to assemble the coil device and enabling the manufacture of a sturdy coil device.

[0016] Preferably, the first terminal second portion, the second terminal second portion, the third terminal second portion, and the fourth terminal second portion are arranged on the same plane perpendicular to the second axis on the second direction side opposite to the first direction along the second axis, and are configured to be mountable.

[0017] This configuration allows for easy mounting by grounding the second direction side along the second axis to a substrate, etc. Also, the connection position is located on the opposite side of the flange from the mounting surface, making mounting to a substrate, etc., stable.

[0018] Preferably, the winding core has a flat surface on the first direction side along the second axis. In this way, the winding core does not have an intermediate flange or the like that separates the coil portions, which reduces the influence of magnetic flux that sneaks between the coil portions.

[0019] Preferably, the rotor has a plate core that magnetically connects the first flange and the second flange, and with this configuration, a closed magnetic circuit can be formed by the drum core and the plate core.

[0020] Preferably, the planar core has a flat bottom surface facing the winding core portion. By having such a flat bottom surface of the planar core, the influence of magnetic flux sneaking between the coil portions can be reduced. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic perspective view showing the configuration of a coil device according to one embodiment of the present invention. [Figure 2A] FIG. 2A is a plan view of the coil device shown in FIG. [Figure 2B] FIG. 2B is a side view of the coil device shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. 2A. [Figure 4] FIG. 4 is a schematic perspective view showing a configuration of a part of the coil device shown in FIG. [Figure 5A]FIG. 5A is a plan view of a coil device according to another embodiment of the present invention. [Figure 5B] FIG. 5B is a side view of the coil device shown in FIG. 5A. [Figure 6] FIG. 6 is a graph showing the relationship between the stray capacitance between the coil portions of the coil devices according to the example and the comparative example and the frequency of the applied voltage. [Figure 7] FIG. 7 is a graph showing the relationship between the stray capacitance and the frequency of the applied voltage for the entire coil device according to the example and the comparative example. [Figure 8] FIG. 8 is a graph showing the relationship between the stray capacitance and the frequency of the applied voltage for one coil portion of the coil device according to the embodiment. [Figure 9] FIG. 9 is a graph showing the relationship between the stray capacitance and the frequency of the applied voltage for the other coil portion of the coil device according to the embodiment. [Figure 10] FIG. 10 is a graph showing the relationship between the stray capacitance and the frequency of the applied voltage for the entire coil device according to the embodiment. [Figure 11] FIG. 11 is a graph showing the relationship between the stray capacitance between the coil portions of the coil devices according to the example and the comparative example and the frequency of the applied voltage. [Figure 12] FIG. 12 is a graph showing the relationship between the stray capacitance and the frequency of the applied voltage for the entire coil device according to the example and the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0023] First embodiment (Overall configuration of the coil device) As an embodiment of the coil device according to the present embodiment, the overall configuration of a differential mode inductor having a function as, for example, a noise filter will be described.

[0024] As shown in Figure 1, the coil device 1 of this embodiment has an approximately rectangular parallelepiped shape overall, and includes a first wire 60, a second wire 70, a drum core 20 having a winding core portion 30 around which the first wire 60 and the second wire 70 are wound, and a plate core 10.

[0025] The coil device 1 has outer dimensions of, for example, an X-axis length of 4.3 to 4.7 mm, a Z-axis height of 2.6 to 3.0 mm, and a Y-axis width of 3.0 to 3.4 mm, but the size of the coil device 1 is not limited to this.

[0026] The drum core 20 includes a winding core 30 extending along the Y axis, a first flange 40 provided at one end of the winding core 30, and a second flange 50 provided at the other end of the winding core 30. In this specification, the direction from the second flange 50 to the first flange 40 in the winding core 30 is sometimes referred to as the positive direction of the Y axis, and the opposite direction is sometimes referred to as the negative direction. In the drawings, the X axis, Y axis, and Z axis are approximately perpendicular to each other. In this embodiment, the first axis corresponds to the Y axis, and the second axis corresponds to the Z axis.

[0027] As shown in FIG. 3, the winding core 30 has a substantially rectangular YZ cross section. As shown in FIG. 1, the winding core 30 has a rectangular parallelepiped shape with a flat surface 30a, a first side surface 30b, a second side surface 30c, and a bottom surface 30d on its outer surface. The first side surface 30b and the second side surface 30c form the outer surfaces on both sides of the X axis. In this specification, the direction from the second side surface 30c toward the first side surface 30b is sometimes referred to as the positive direction of the X axis, and the opposite direction is sometimes referred to as the negative direction. The flat surface 30a and the bottom surface 30d form the outer surfaces on both sides of the Z axis. In this specification, the direction from the bottom surface 30d toward the flat surface 30a is sometimes referred to as the positive direction of the Z axis, and the opposite direction is sometimes referred to as the negative direction. In this embodiment, the first direction of the Z axis is the positive direction, and the second direction is the negative direction.

[0028] 2A, the first flange 40 and the second flange 50 have substantially the same shape and are formed symmetrically across the winding core 30. The first flange 40 is composed of a first main body portion 41 connected to the winding core 30, a first sub-body portion 42 extending from the main body portion 41 in the positive direction of the X axis, and a second sub-body portion 43 extending from the main body portion 41 in the negative direction of the X axis.

[0029] As shown in FIG. 1, the first main body section 41 has a substantially rectangular parallelepiped shape with the Z-axis direction as the height direction, the X-axis direction as the width direction, and the Y-axis direction as the depth direction. The first main body section 41 is formed with substantially the same width as the winding core section 30. The first main body section top surface 41a of the first main body section 41 protrudes from the flat surface 30a of the winding core section 30 and is substantially parallel to the XY plane, and the first main body section bottom surface 41f of the first main body section 41 faces the first main body section top surface 41a and is substantially parallel to the XY plane. The first main body section top surface 41a and the first main body section bottom surface 41f are substantially perpendicular to the first main body section front surface 41b, which is positioned in the positive direction of the Y axis. Furthermore, as shown in FIG. 2A, the first main body section back surface 41c of the first main body section 41 is connected to the winding core section 30. The first side surface 41d of the first main barrel section 41 forms the extending base end portion of the first sub-barrel section 42, and the second side surface 41e of the first main barrel section forms the extending base portion of the second sub-barrel section 43.

[0030] As shown in FIG. 1, the first sub-body section 42 has a generally rectangular parallelepiped shape with its height direction in the Z-axis direction, its width direction in the X-axis direction, and its depth direction in the Y-axis direction. As shown in FIG. 2A, the negative X-axis direction of the first sub-body section 42 is connected to the first main body section first side surface 41d. The first sub-body section top surface 42a of the first sub-body section 42 is recessed in the negative Z-axis direction relative to the first main body section top surface 41a. The first sub-body section bottom surface 42f, which faces the first sub-body section top surface 42a of the first sub-body section 42, is flush with the first main body section bottom surface 41f. The first sub-body section front surface 42b, which constitutes the outer surface of the first sub-body section 42 in the positive Y-axis direction, is disposed generally parallel to the first main body section front surface 41b and is recessed relative to the first main body section first side surface 41d41b of the first main body section 41. The first sub-body dummy surface 42c of the first sub-body 42 is flush with the first main body dummy surface 41c. The first sub-body side surface 42d of the first sub-body 42 intersects the first sub-body top surface 42a, the first sub-body bottom surface, the first sub-body front surface 42b, and the first sub-body dummy surface 42c, and is disposed parallel to the first main body first side surface 41d.

[0031] The second sub-body section 43 has a generally rectangular parallelepiped shape with its height direction in the Z-axis direction, its width direction in the X-axis direction, and its depth direction in the Y-axis direction. The positive direction of the X-axis of the second sub-body section 43 is connected to the first main body section second side surface 41e, and is configured plane-symmetrical with the first sub-body section 42. The second sub-body section 43 is configured with a second sub-body section top surface 43a corresponding to the first sub-body section top surface 42a, a second sub-body section bottom surface corresponding to the first sub-body section bottom surface 42f, a second sub-body section front surface 43b and a second sub-body section back surface 43c corresponding to the first sub-body section front surface 42b and the first sub-body section back surface 42c, and a second sub-body section side surface 43e corresponding to the first sub-body section side surface 42d.

[0032] 2A, the third flange 50 is also composed of a second main body section 51 located in the opposite direction to the second main body section 41 across the winding core section 30 in the Y-axis direction, a third sub-body section 52 extending in the same positive direction of the X-axis as the first sub-body section 42, and a fourth sub-body section 53 extending in the same negative direction of the X-axis as the second sub-body section 43. The second main body section 51 is composed of a second main body section top surface 51a, a second main body section front surface 51b, a second main body section back surface 51c, a second main body section first side surface 51d, a second main body section second side surface 51e, and a second main body section bottom surface 51f (FIG. 1). The third sub-body section 52 is composed of a third sub-body section top surface 52a, a third sub-body section front surface 52b, a third sub-body section dorsal surface 52c, a third sub-body section side surface 52d, and a third sub-body section bottom surface 52f (FIG. 3). The fourth sub-body section 53 is composed of a fourth sub-body section top surface 53a, a fourth sub-body section front surface 53b, a fourth sub-body section dorsal surface 53c, a fourth sub-body section side surface 53e, and a fourth sub-body section bottom surface 53f (FIG. 1) corresponding to the third sub-body section bottom surface 52f.

[0033] As shown in FIG. 1 , a first terminal 81 and a second terminal 82 are formed on the first flange 40. The first terminal 81 is arranged in the first sub-body section 42, and the second terminal 82 is arranged in the second sub-body section 43. A third terminal 91 and a fourth terminal 92 are formed on the second flange 50. The third terminal 91 is arranged in the third sub-body section 52, and the fourth terminal 92 is arranged in the fourth sub-body section 53. The first terminal 81 and the second terminal 82 are arranged symmetrically with respect to a plane across the first main body section 41 in the X-axis direction, and the first terminal 81 and the third terminal 91 are arranged symmetrically with respect to a plane across the winding core section 30 in the Y-axis direction. Furthermore, the second terminal 82 and the fourth terminal 91 are arranged symmetrically with respect to a plane across the winding core section 30 in the Y-axis direction.

[0034] As shown in Fig. 4, the first terminal 81 is generally U-shaped and includes a first terminal first portion 81a and a first terminal second portion 81f, which form a pair of arms of the U-shape, and a first connecting portion 81b connecting the pair of arms. The first terminal first portion 81a has a plane perpendicular to the Z-axis. The first terminal second portion 81f has a plane parallel to the first terminal first portion 81a and is disposed on the opposite side of the first terminal first portion 81a across the Z-axis, with the first flange 40 shown in Fig. 3 sandwiched between them. The first terminal first portion 81a, the first terminal second portion 81f, and the first connecting portion 81b are formed by bending a single metal plate. The first terminal 81 is fixed to the first sub-body section 42 with the first terminal first portion 81a and the first terminal second portion 81f sandwiching the first sub-body section top surface 42a and the first sub-body section bottom surface 42f of the first sub-body section 42 shown in Fig. 3, and the inner surface of the first connecting portion 81b abutting against the first sub-body section front surface 42b. The terminal and the flange may be bonded using a non-conductive adhesive.

[0035] 2A, first terminal first portion 81a of first terminal 81 has first holding piece 81c and second holding piece 81d on the side portion facing first main body first side surface 41d. As shown in Fig. 4, first holding piece 81c and second holding piece 81d are bent at the connection portion with first terminal first portion 81a so as to abut against the outer surface of first terminal first portion 81a.

[0036] As shown in FIG. 2A, in this embodiment, the first terminal 81 is connected to the first wire 60 by clamping the first connection portion 63 of the first lead-out portion 61 between the first holding piece 81c, the second holding piece 81d and the first terminal first portion 81a.

[0037] Similar to the first terminal 81, the second terminal 82 is U-shaped and includes a second terminal first portion 82a corresponding to the first terminal first portion 81a, a second terminal second portion 82f corresponding to the first terminal second portion 82f, and a second connecting portion 82b corresponding to the first connecting portion 81b connecting the pair of arm portions. The second terminal 82 is fixed to the second sub-body portion 43 and connected to the second connecting portion 64.

[0038] As shown in Fig. 4, like the first terminal 81, the third terminal 91 is also U-shaped and includes a third terminal first portion 91a corresponding to the first terminal first portion 81a, a third terminal second portion 91f corresponding to the first terminal second portion 81f, and a third connecting portion 91b corresponding to the first connecting portion 81b. As shown in Fig. 3, the third terminal 91 is fixed to the third sub-body portion 52 in a state in which the third sub-body portion top surface 52a and the third sub-body portion bottom surface 52f of the third sub-body portion 52 are sandwiched between them. As shown in Fig. 2A, like the first terminal 81, the third terminal 91 is connected to the third connection portion 73 of the second wire 60.

[0039] Like the third terminal, the fourth terminal 92 is U-shaped and includes a fourth terminal first portion 92a corresponding to the first terminal first portion 81a, a fourth terminal second portion 92f corresponding to the first terminal second portion 81f, and a fourth linking portion 92b corresponding to the first linking portion 81b. The fourth terminal 92 is fixed to the second sub-body portion 53 and connected to the fourth connecting portion 74.

[0040] In this embodiment, the portion of the first terminal 81 that is connected to the first connection portion 63 is referred to as the first connection position. Similarly to the first terminal 81, the portions of the second terminal 82, the third terminal 91, and the fourth terminal 92 that are connected to the second connection portion 64, the third connection portion 73, and the fourth connection portion 74 are referred to as the second connection position, the third connection position, and the fourth connection position, respectively.

[0041] As shown in FIG. 2A , the first wire 60 forms a first coil portion 60a that is wound so as to be pressed against the winding core 30. Specifically, a first winding end 65a of the first coil portion 60a is disposed at a corner portion that is the boundary between the flat surface 30a and the first side surface 30b of the winding core 30. The first coil portion 60a is wound from the first winding end 65a along the outer surface of the winding core 30, in the order of the first side surface 30b, the bottom surface, the second side surface 30c, and the flat surface 30a, from the vicinity of the first flange 40 toward the second flange 50, and a second winding end 66a of the first coil portion 60a is disposed at a corner portion that is the boundary between the flat surface 30a and the second side surface 30c. As shown in FIG. 3 , the first coil portion 60a is disposed closer to the first flange 40 than a center position 33 of the winding core 30.

[0042] 2A, the first wire 60 has a first lead-out portion 61 between the first winding end 65a and the first connection portion 63. The first wire 60 is bent at the first winding end 65a and led out from the first coil portion 60a toward the first connection position 81a1. In this embodiment, the first winding end 65a is located in the first outer winding portion 65 of the first coil portion 60a, closest to the first connection position 81a1 of the first terminal 81 with the first wire 60.

[0043] The first wire 60 has a second lead-out portion 62 between the second winding end 66a and the second connection portion 64. The first wire 60 is bent at the second winding end 66a and led out from the first coil portion 60a toward the second connection position 82a1. In this embodiment, the second winding end 66a is located in the first inner winding portion 66 of the first coil portion 60a, which is farthest from the second connection position 82a1 of the second terminal 82 with the first wire 60.

[0044] As shown in FIG. 2A , the second wire 70 forms a second coil portion 70a that is wound so as to be pressed against the winding core portion 30. Specifically, a fourth winding end 76a of the second coil portion 70a is disposed at a corner portion that is the boundary between the flat surface 30a and the second side surface 30c of the winding core portion 30. The second coil portion 70a is wound from the fourth winding end 76a along the outer surface of the winding core portion 30, in the order of the flat surface 30a, the first side surface 30b, the bottom surface, and the second side surface 30c, from the vicinity of the second flange portion 50 toward the first flange portion 40, and a third winding end 75a of the second coil portion 70a is disposed at a corner portion that is the boundary between the flat surface 30a and the first side surface 30b. As shown in FIG. 3 , the second coil portion 70a is disposed closer to the second flange portion 50 than the center position 33.

[0045] 2A , the second wire 70 has a fourth lead-out portion 72 between the fourth winding end 76a and the fourth connection portion 74. The second wire 70 is bent at the fourth winding end 76a and led out from the second coil portion 70a toward the fourth connection position 92a1. In this embodiment, the fourth winding end 76a is located in the second outer winding portion 76 of the second coil portion 70a, closest to the fourth connection position 92a1 of the fourth terminal 92 with the second wire 70.

[0046] The second wire 70 has a third lead-out portion 71 between the third winding end portion 75a and the third connection portion 73. The second wire 70 is bent at the third winding end portion 75a and led out from the second coil portion 70a toward the third connection position 91a1. In this embodiment, the third winding end portion 75a is located in the second inner winding portion 75 of the second coil portion 70a, closest to the third connection position 91a1 of the third terminal 91 with the second wire 70.

[0047] 2B, the first winding width W1 of the first coil portion 60a is determined by the component along the Y axis of the distance between the first outer winding portion 65 closest to the first flange 40 and the first inner winding portion 66 farthest from the first flange 40 in the first coil portion 60a. In addition, the second winding width W2 of the second coil portion 70a is determined by the component along the Y axis of the distance between the second outer winding portion 76 closest to the second flange 50 and the second inner winding portion 75 farthest from the second flange 50 in the second coil portion 70a.

[0048] As shown in Fig. 3, in this embodiment, the first coil portion 60a and the second coil portion 70a are each formed of a single layer of winding. As shown in Fig. 2B, the first winding end portion 65a is arranged in the first outer winding portion 65, and the second winding end portion 66a is arranged in the first inner winding portion 66. Furthermore, the third winding end portion 75a is arranged in the second inner winding portion 75, and the fourth winding end portion 76a is arranged in the second outer winding portion 76.

[0049] The first coil portion 60a and the second coil portion 70a may be formed by stacking multiple layers of winding. When the first coil portion is formed by an even number of layers of winding, for example, the first winding end portion 65a and the second winding end portion 66a are located in the first outer winding portion, and the folded portion between the first and second layers of the first coil portion is located in the first outer winding portion.

[0050] In this embodiment, although there may be a gap between the end windings and the outer surface of the winding core 30, it is preferable that the end windings contact the outer surface of the winding core. If the coil is formed of multiple layers of winding, the end windings are disposed on the outside of the layer closest to the winding core. In this case, it is preferable that the end windings contact the layer closest to the winding core.

[0051] 2B, in this embodiment, the separation distance W3 between the first coil portion 60a and the second coil portion 70a is determined by the component along the Y axis of the distance between the first inner winding portion 66 and the second inner winding portion 75. The first coil portion 60a is disposed near the first flange portion 40 and separated from the second coil portion 70a by the separation distance W3.

[0052] In this embodiment, the first coil portion 60a and the second coil portion 70a are spaced apart so that the relationships W3 > W1 and W3 > W2 are satisfied. By ensuring a sufficient distance between one wire and the other, the stray capacitance between the first coil portion 60a and the second coil portion 70a is reduced, thereby enabling the reduction of the stray capacitance of the coil device 1. The lengths of W1, W2, and W3 are not limited as long as they satisfy these relationships. For example, W1 can be 0.74 to 0.78 mm, W2 can be 0.73 to 0.75 mm, and W3 can be 1.14 to 1.18 mm. While it is sufficient to satisfy either the relationship W3 > W1 or W3 > W2, satisfying both relationships facilitates the matching of the characteristics of the first coil portion 60a and the second coil portion 70a, facilitating the manufacture of a coil device suitable for use as a common mode filter.

[0053] In this embodiment, the first coil portion and the second coil portion have approximately the same number of turns, but they may differ depending on the application. Note that "approximately the same number of turns" means that the ratio of the number of turns is in the range of 0.75 to 1 / 0.75, and preferably 1.

[0054] In this embodiment, the lengths of the first, second, third, and fourth lead-out portions vary depending on the shapes and dimensions of the winding core portion, the first flange portion, and the second flange portion, but are preferably short. Also, it is preferable that the lead-out portions are far from the coil portions.

[0055] 2A , in this embodiment, the first lead portion 61 of the first wire 60 is led from the first winding end portion 65a of the first coil portion 60a toward the first sub-torso portion 42 of the first flange portion 40, where the first terminal 81 is disposed. The second lead portion 62 of the first wire 60 is led from the second winding end portion 66a of the first coil portion 60a toward the second sub-torso portion 43 of the first flange portion 40, where the second terminal 82 is disposed. The first coil portion 60a is located near the first flange portion 40 along the Y-axis and spaced apart from the second coil portion 70a. Therefore, the first lead portion 61 and the second lead portion 62 are led out without straddling the second coil portion 70a, which reduces stray capacitance generated between the first lead portion 61 and the second lead portion 62 and the second coil portion 70a.

[0056] 2A , in this embodiment, the third lead portion 71 of the second wire 70 is led from the third winding end portion 75a of the second coil portion 70a toward the first sub-body portion 52 of the second flange portion 50, where the third terminal 91 is disposed. The fourth lead portion 72 of the second wire 70 is led from the fourth winding end portion 76a of the second coil portion 70a toward the second sub-body portion 53 of the second flange portion 50, where the fourth terminal 92 is disposed. The second coil portion 70a is located near the second flange portion 50 along the Y-axis and spaced apart from the first coil portion 60a. Therefore, the third lead portion 71 and the fourth lead portion 72 are led out without straddling the first coil portion 60a, which reduces stray capacitance generated between the third lead portion 71 and the fourth lead portion 72 and the first coil portion 60a.

[0057] As shown in FIG. 2A, in this embodiment, the first connection portion 63 is disposed at the first connection position 81a1, and the second connection portion 64 is disposed at the second connection position 82a1. The first connection position 81a1 and the second connection position 82a1 are both disposed on the positive side (first direction side) of the first flange portion 40 along the Z axis. The third connection portion 73 is disposed at the third connection position 91a1, and the fourth connection portion 74 is disposed at the fourth connection position 92a1. The third connection position 91a1 and the fourth connection position 92a1 are both disposed on the positive side (first direction side) along the Z axis. The first connection position 81a1 to the fourth connection position 92a1 are disposed on the same plane perpendicular to the Z axis.

[0058] In this way, by arranging all connection positions on the positive side along the Z axis, it becomes easier to mount the capacitor on a circuit board, etc., with the negative side facing the mounting surface. Furthermore, it also becomes easier to adopt a configuration in which a closed magnetic circuit is formed using the planar core 10.

[0059] 2A, in this embodiment, the first connection position 81a1 is located on the opposite side of the second connection position 82a1 in the X-axis direction to the connection portion 41c1 where the first flange portion 40 is connected to the winding core portion 30. The third connection position 91a1 is located on the opposite side of the fourth connection position 92a1 in the X-axis direction to the connection portion 51c1 where the second flange portion 50 is connected to the winding core portion 30.

[0060] That is, in this embodiment, both ends of each wire can be pulled out so as to be spaced apart on both sides in the X-axis direction from the coil portion formed on the winding core portion 30. This makes it possible to reduce the stray capacitance that occurs between the coil portion and the pulled-out portion in the wire.

[0061] 2A, in this embodiment, the first winding end portion 65a is disposed at the corner where the flat surface 30a and the side surface 30b of the winding core portion 30 meet. That is, of the four corners where the surfaces of the winding core portion 30 meet, the first winding end portion 65a is disposed at the corner closest to the first connection position 81a1 of the first terminal 81. The first wire 60 is bent at the first winding end portion 65a and drawn out toward the first connection position 81a1 so as to be away from the first coil portion 60a. Drawing out the wire in this manner makes it possible to shorten the first drawn-out portion 61, thereby reducing stray capacitance generated between the first coil portion 60a and the first drawn-out portion 61.

[0062] 2A, in this embodiment, the second winding end portion 66a is disposed at the corner where the flat surface 30a and the side surface 30c of the winding core portion 30 meet. That is, of the four corners where the surfaces of the winding core portion 30 meet, the second winding end portion 66a is disposed at the corner closest to the second connection position 82a1 of the second terminal 82. The first wire 60 is bent at the second winding end portion 66a and drawn out toward the second connection position 82a1 so as to be away from the first coil portion 60a. Drawing out the wire in this manner makes it possible to shorten the second lead portion 62, thereby reducing stray capacitance generated between the first coil portion 60a and the second lead portion 62.

[0063] 2A , in this embodiment, the third winding end portion 75a is disposed at the corner where the flat surface 30a and the side surface 30b of the winding core portion 30 meet. That is, of the four corners where the surfaces of the winding core portion 30 meet, the third winding end portion 75a is disposed at the corner closest to the third connection position 91a1 of the third terminal 91. The second wire 70 is bent at the third winding end portion 75a and drawn out toward the third connection position 91a1 of the third terminal 91 so as to be away from the second coil portion 70a. Drawing out the wire in this manner makes it possible to shorten the third lead portion 71, thereby reducing the stray capacitance generated between the second coil portion 70a and the third lead portion 71.

[0064] 2A , in this embodiment, the fourth winding end portion 76a is located at the corner where the flat surface 30a and the side surface 30c of the winding core portion 30 meet. That is, of the four corners where the surfaces of the winding core portion 30 meet, the fourth winding end portion 76a is located at the corner closest to the fourth connection position 92a1 of the fourth terminal 92. The second wire 70 is bent at the fourth winding end portion 76a and drawn out toward the fourth connection position 92a1 of the fourth terminal 92 so as to be away from the second coil portion 70a. Drawing out the wire in this manner makes it possible to shorten the fourth lead portion 72, thereby reducing stray capacitance generated between the second coil portion 70a and the fourth lead portion 72.

[0065] In this embodiment, the winding core has a generally rectangular parallelepiped shape with a generally square cross section perpendicular to the Y axis, but is not limited to this. For example, the cross section perpendicular to the Y axis of the winding core may be a circle or a polygon other than a rectangle. Even if the cross section perpendicular to the Y axis of the winding core is not a square, it is preferable that the wire is drawn out toward the terminal connection position by arranging the winding end portions so that the distance between each lead-out portion is short.

[0066] As shown in FIG. 4, in this embodiment, the first terminal 81 has a U-shape and includes a first terminal first portion 81a, a first terminal second portion 81f, and a first connecting portion 81b connecting the first terminal first portion 81a and the first terminal second portion 81f. The second terminal 82, the third terminal 91, and the fourth terminal 92 have the same structure as the first terminal 81. As shown in FIG. 1, these terminals can be attached by sandwiching the first flange 40 or the second flange 50 from both sides in the Z-axis direction. Therefore, the terminals can be easily and firmly attached to the flanges, improving the strength of the coil device.

[0067] As shown in FIG. 4 , in this embodiment, the first terminal second portion 81f, the second terminal second portion 82f, the third terminal second portion 91f, and the fourth terminal second portion 92f are all disposed on the negative side along the Z axis. The first terminal second portion 81f, the second terminal second portion 82f, the third terminal second portion 91f, and the fourth terminal second portion 92f are all disposed on the same XY plane. The negative sides along the Z axis of the first terminal second portion 81f, the second terminal second portion 82f, the third terminal second portion 91f, and the fourth terminal second portion 92f are flat, allowing for easy mounting on a substrate or the like. Furthermore, the mounting surface is disposed on the opposite side of the flange in the Z axis direction from the position where the terminal is connected to the wire, thereby stably mounting on a substrate or the like.

[0068] 2B , in this embodiment, the positive side along the Z axis of the winding core 30 is a flat surface 30a. That is, in the winding core 30, the outer surfaces are flush with each other from the portion where the first coil portion 60a is disposed to the portion where the second coil portion 70a is disposed, and no intermediate flange or the like is formed between the first coil portion 60a and the second coil portion 70a to separate them. Because the positive side along the Z axis of the winding core 30 is a flat surface 30a, magnetic flux is less likely to enter between the first coil portion 60a and the second coil portion 70a, which reduces the effect of magnetic flux on the characteristics of the coil device.

[0069] As shown in Fig. 1, in this embodiment, the planar core 10 is disposed on the positive side of the drum core 20 along the Z axis. The planar core bottom surface 10a of the planar core 10 is bonded to the first main barrel portion top surface 41a of the first main barrel portion 41 of the first flange portion 40 and the second main barrel portion top surface 51a of the second main barrel portion 51 of the second flange portion 50. The planar core 10 magnetically connects the first flange portion 40 and the second flange portion 50. A closed magnetic circuit is formed by the first flange portion 40, the winding core portion 30, the second flange portion 50, and the planar core 10, making it possible to reduce magnetic loss.

[0070] 1, in this embodiment, the bottom surface 10a of the planar core 10 is a flat surface facing the winding core portion 30. In other words, in this embodiment, no protrusions are formed between the first coil portion 60a and the second coil portion 70a to allow magnetic flux to flow around. Because the bottom surface 10a of the planar core 10 is flat, magnetic flux is less likely to enter between the first coil portion 60a and the second coil portion 70a, reducing the effect of magnetic flux on the characteristics of the coil device.

[0071] (Manufacturing method of coil device 1) Next, a method for manufacturing the coil device 1 according to one embodiment of the present invention will be specifically described.

[0072] In manufacturing the coil device 1, first, the drum core 20, the plate-shaped member 10, the first wire 60, the second wire 70, and the terminals 81, 82, 91, and 92 are prepared. The drum core 20 and the plate core 10 are each made of a different magnetic material, and although it is preferable that these materials are the same, they may also be made of different magnetic materials.

[0073] Examples of magnetic materials include magnetic materials with relatively high magnetic permeability, such as Ni-Zn ferrite, Mn-Zn ferrite, or metallic magnetic materials, and the drum core and plate core are produced by molding and sintering powder of these magnetic materials. The drum core 20 shown in Figure 1 has a winding core portion 30, a first flange portion 40, and a second flange portion 50 molded integrally.

[0074] Next, the first terminal 81 and the second terminal 82 are attached to the first flange 40. Furthermore, the third terminal 91 and the fourth terminal 92 are attached to the second flange 50. At this time, a non-conductive adhesive may be interposed between the terminals and the flange to bond them together.

[0075] The terminal is formed into the shape shown in Fig. 4 by bending a strip-shaped metal plate whose main components are copper alloys such as phosphor bronze and brass, phosphorus, copper, tin, iron, zinc, etc. Furthermore, a known plating layer of nickel, tin, etc. may be formed on the surface of the terminal opposite to the flange. Note that the terminal is not limited to a metal plate, and may be formed by applying a metal paste to the flange and baking it.

[0076] 1, the first wire 60 is wound around the winding core 30 to form the first coil portion 60a. The wire can be wound by a known method, such as winding with an automatic winding device or manual winding.

[0077] 2A, the first winding end 65a of the first wire 60 is pressed against a predetermined corner that is the boundary between the flat surface 30a and the first side surface 30b, and the first lead-out portion 61 is bent and drawn out toward the first terminal first portion 81a of the first terminal 81. The first connecting portion 63, which is the wire end of the first lead-out portion 61, is connected to the first terminal first portion 81a.

[0078] The second winding end 66a of the first wire 60 is pressed against a predetermined corner that is the boundary between the flat surface 30a and the second side surface 30c, and the second lead-out portion 62 is bent and drawn out toward the first clamping portion 82a of the second terminal 82. The second connecting portion 64, which corresponds to the wire end of the second lead-out portion 62, is connected to the first clamping portion 82a.

[0079] Similar to the first wire 60, the second wire 70 is wound around the winding core 30 to form a second coil portion 70a.

[0080] The fourth winding end 76a of the second wire 70 is pressed against a predetermined corner that is the boundary between the flat surface 30a and the second side surface 30c, and the fourth lead-out portion 71 is bent and drawn out toward the first clamping portion 92a of the fourth terminal 92. The fourth connecting portion 74, which corresponds to the wire end of the fourth lead-out portion 71, is connected to the first clamping portion 92a of the fourth terminal 92.

[0081] The third winding end 75a of the second wire 70 is pressed against a predetermined corner that is the boundary between the flat surface 30a and the first side surface 30b, and the third lead-out portion 71 is bent and drawn out toward the first clamping portion 91a of the third terminal 91. The third connecting portion 73, which corresponds to the wire end of the third lead-out portion 71, is connected to the first clamping portion 91a.

[0082] The method for connecting the wire and the terminal is not particularly limited, but for example, the wire connection portion can be sandwiched between the first holding piece, the second holding piece, and the first clamping portion, and a heater chip or the like pressed against the clamping portion to thermocompress the wire connection portion to connect the wire and the terminal. Note that the insulating material covering the core of the wire melts with the heat during thermocompression, so there is no need to remove the coating from the wire. The wire and the terminal can be connected, for example, by wrapping the first connection portion around the first holding piece, or by using a joining material such as solder, laser welding, or the like.

[0083] Second embodiment The coil device 1a according to this embodiment differs from the first embodiment only in the arrangement of the winding end portions, and so a description of the common parts will be omitted and the following description will focus mainly on the different parts. The parts not described below are the same as those described in the first embodiment.

[0084] 5A, in this embodiment, the first winding end portion 65a is disposed at a corner that is the boundary between the first side surface 30b and the bottom surface of the winding core portion 30. The first drawn-out portion 61 is bent at the first winding end portion 65a and drawn out toward a first connection position 81a1 with the first connecting portion 63 of the first terminal 81.

[0085] 5B, second winding end portion 66a is disposed at the corner that is the boundary between second side surface 30c and bottom surface 30d of winding core portion 30. Second lead-out portion 62 is bent at second winding end portion 62 and drawn out toward second connection position 82a1 with second connection portion 64 of second terminal 82. Therefore, second lead-out portion 62 is drawn out so as to straddle first coil portion 60a in the negative direction of the X axis.

[0086] 5A, third winding end portion 75a is disposed at the corner that is the boundary between first side surface 30b and flat surface 30a of winding core portion 30. Third lead-out portion 71 is bent at third winding end portion 75a and is drawn out toward third connection position 91a1 with third connection portion 73 of third terminal 91. Therefore, third lead-out portion 71 is drawn out so as to straddle second coil portion 70a in the positive direction of the Z axis.

[0087] The fourth winding end 76a is disposed at the corner that is the boundary between the second side surface 30c and the flat surface 30a of the winding core 30. The fourth drawn-out portion 72 is bent at the fourth winding end 76a and drawn out toward a fourth connection position 92a1 with the fourth connecting portion 74 of the fourth terminal 92.

[0088] In this embodiment, by arranging the winding end portions in this manner, it is possible to make the angle at which the wire is bent at the winding end portions smaller than in Embodiment 1. Therefore, the coil device 1a of this embodiment has a shape that makes it easy to wind using an automatic winding device.

[0089] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0090] For example, the winding end portions may be positioned in the middle of the outer surface rather than at the corners of the outer surface of the winding core. Specifically, the third winding end portion 75a of the second wire 70 shown in Fig. 2A may be positioned at the middle of the X axis of the flat surface 30a of the winding core 30. Furthermore, the fourth winding end portion 76a of the second wire 70 may be positioned at the middle of the X axis of the flat surface 30a. [Example]

[0091] (Drawer replacement test) A coil device 1a according to the second embodiment shown in FIG. 5A was designated Example 1. In the coil device 1a according to Example 1, the first winding width W1 was 0.74 mm, the second winding width W2 was 0.73 mm, and the separation distance W3 between the coil portions was 1.18 mm. A conventional coil device was designated Comparative Example 1. The coil device according to Comparative Example 1 is similar to Example 1 except that the lead-out positions of the first lead-out portion 61 and the fourth lead-out portion 72 are swapped. That is, in Comparative Example 1, the first lead-out portion 61 of the first wire 60 is led out to the fourth terminal 92 on the second flange portion 50 side, and the fourth lead-out portion 72 of the second wire 70 is led out to the first terminal 81 on the first flange portion 40 side. In the coil device of Comparative Example 1, the first winding width W1 was 0.75 mm, the second winding width W2 was 0.71 mm, and the separation distance W3 between the coil portions was 1.18 mm.

[0092] The electrostatic capacitance (stray capacitance) between the first coil portion 60a and the second coil portion 70a was measured for the coil device according to Example 1 and the coil device according to Comparative Example 1. The results are shown in FIG.

[0093] Furthermore, the capacitance of the entire coil device was measured using the coil device according to Example 1 and the coil device according to Comparative Example 1. The results are shown in FIG.

[0094] The stray capacitance between the first coil portion and the second coil portion shown in Fig. 6 was 0.203 pF on average for each sample in Example 1 and 0.666 pF on average for each sample in Comparative Example 1 when the frequency of the applied voltage was 1 GHz. Furthermore, the stray capacitance of the entire coil device shown in Fig. 7 was 0.257 pF on average for each sample in Example 1 and 0.294 pF on average for each sample in Comparative Example 1 when the frequency of the applied voltage was 1 GHz.

[0095] From these results, it was found that by interchanging the lead-out positions of the first lead-out portion 61 and the fourth lead-out portion 72, it was possible to reduce the stray capacitance of the coil device.

[0096] (End winding change test) The coil device 1 according to the first embodiment shown in FIG. 2A was used as Example 2. In the coil device 1 according to Example 2, the first winding width W1, the second winding width W2, and the coil portion separation distance W3 were the same as those of the coil device according to Example 1. The capacitance (stray capacitance) of the first coil portion 60a of the coil device according to Example 1 and the capacitance (stray capacitance) of the first coil portion 60a of the coil device according to Example 2 were measured. The results are shown in FIG. 8.

[0097] Furthermore, the capacitance (stray capacitance) of the first coil portion 60b of the coil device according to Example 1 and the capacitance (stray capacitance) of the second coil portion 60b of the coil device according to Example 2 were measured. The results are shown in FIG.

[0098] Moreover, the electrostatic capacitance (stray capacitance) of the entire coil device of the coil device according to Example 1 and the electrostatic capacitance (stray capacitance) of the entire coil device of the coil device according to Example 2 were measured. The results are shown in FIG.

[0099] The stray capacitance of the first coil portion shown in Fig. 8 was 0.257 pF on average for each sample in Example 1 and 0.251 pF on average for each sample in Example 2 when the frequency of the applied voltage was 1 GHz. Also, the stray capacitance of the second coil portion shown in Fig. 9 was 0.263 pF on average for each sample in Example 1 and 0.256 pF on average for each sample in Example 2 when the frequency of the applied voltage was 1 GHz. Also, as shown in Fig. 10, the stray capacitance of the entire coil device was 0.257 pF on average for each sample in Example 1 and 0.244 pF on average for each sample in Example 2 when the frequency of the applied voltage was 1 GHz.

[0100] Based on these results, it was possible to reduce the stray capacitance of the coil device by changing the arrangement of the first, second, third, and fourth winding ends and shortening the lead-out section.

[0101] (Coil distance change test) Regarding the coil device 1 according to the first embodiment shown in FIG. 2A, a coil device was prepared in which the first winding width W1 was 0.76 mm, the second winding width W2 was 0.75 mm, and the coil portion separation distance W3 was 1.16 mm. Example 3 For the coil device according to Example 2 and the coil device according to Comparative Example 2, the electrostatic capacitance (stray capacitance) between the first coil portion 60a and the second coil portion 70a was measured. The results are shown in Figure 11.

[0102] Also, a coil device according to a similar second embodiment and Example 3 The capacitance of the entire coil device was measured using the coil device described above, and the results are shown in Figure 12.

[0103] As shown in FIG. 11, the stray capacitance between the first coil portion and the second coil portion is 0.203 pF on average for each sample in Example 2 when the frequency of the applied voltage is 1 GHz. Example 3 12, the stray capacitance of the entire coil device was 0.244 pF on average for each sample in Example 2 when the frequency of the applied voltage was 1 GHz. Example 3 The average capacitance for each sample was 0.311pF.

[0104] From these results, it was found that by making the separation distance W3 of the coil parts longer than the first winding width W1 or the second winding width W2, it was possible to reduce the stray capacitance of the coil device. [Explanation of symbols]

[0105] 1, 1a... Coil device 10 Plate core 10a Bottom of plate core 20... Drum Core 30... Winding core 30a...Top surface (flat surface) 30b···First side 30c···Second side view 30d···Bottom 33···Central position 40··· Part 1 41···The 1st Main Body 41a···Top surface of the first main body 41b...1st main body front 41c··· First main body dorsal side 41c1···Continuation part 41d···First Main Torso Part, First Side View 41e···First Main Torso Part, Second Side 41f···First Main Body Bottom Surface 42···1st Deputy Body 42a···Top surface of the first secondary torso 42b...1st trunk front 42c··· First torso dorsal side 42d...1st trunk side 42f···First torso bottom surface 43···Second Deputy Body 43a··· Top surface of the second secondary torso 43b···Second trunk front 43c···Second dorsal side of the torso 43e···Second Sub-Torso Side View 43f···Second Substructure Bottom 50··· Part 2 51···Second Main Body 51a···Top surface of the second main body 51b···Second main body front 51c···Second Main Torso Rear 51c1···Continuation part 51d···Second Main Torso Part, First Side View 51e···Second Main Body, Second Side 51f···Second Main Body Bottom Surface 52···The third deputy body 52a···Top surface of the third sub-torso 52b···The front of the third body part 52c··· Third torso dorsal side 52d···Third side view of the torso 52f··· Third torso bottom surface 53...Fourth sub-body 53a...4th sub-body top surface 53b....Fourth sub-body front 53c...4th sub-torso back 53e...4th sub-body side 53f...Fourth sub-body bottom surface 60···First wire 60a···First coil section 61...1st drawer 62...2nd drawer 63...1st connection section 64...Second connection section 65...First outer winding part 65a... End of the first volume 66...First inner winding part 66b... End of the second volume 70...Second wire 70a Second coil section 71...Third drawer 72...4th drawer 73...Third connection section 74...4th connection section 75...Second inner winding part 75a...End of volume 3 76...Second outer winding part 76a...End of volume 4 81...1st terminal 81a...1st terminal 1st part 81a1···First connection position 81b...1st connection part 81c...1st holding piece 81d...Second holding piece 81f...1st terminal 2nd part 82...2nd terminal 82a...2nd terminal 1st part 82a1···First connection position 82b...Second connection part 82c...1st holding piece 82d...Second holding piece 82f...2nd terminal 2nd part 91...3rd terminal 91a...Third terminal first part 91a1···First connection position 91b...Third connection part 91c...1st holding piece 91d...Second holding piece 91f... 3rd terminal 2nd part 92...4th terminal 92a...4th terminal 1st part 92a1···First connection position 92b...4th connection part 92c...1st holding piece 91d...Second holding piece 92f...4th terminal 2nd part

Claims

1. A coil device including a first wire, a second wire, and a drum core having a winding core portion around which the first wire and the second wire are wound, the drum core has a first flange portion formed at one end of the winding core portion along the first axis, and a second flange portion formed at the other end of the winding core portion along the first axis, The first flange portion is formed with a first terminal and a second terminal to be connected to the first wire, a third terminal and a fourth terminal connected to the second wire are formed on the second flange; the first wire has a first coil portion wound so as to be pressed against the winding core portion, the first coil portion has a first winding width W1 defined by a component of a distance along the first axis between a first outer winding portion closest to the first flange portion and a first inner winding portion farthest from the first flange portion in the first coil portion, the second wire has a second coil portion wound so as to be pressed against the winding core portion, the second coil portion has a second winding width W2 defined by a component of a distance along the first axis between a second outer winding portion closest to the second flange portion and a second inner winding portion farthest from the second flange portion in the second coil portion, the first coil portion is disposed near the first flange portion and separated from the second coil portion by a separation distance W3 defined by a component of the distance between the first inner winding portion and the second inner winding portion in the direction along the first axis, The relationships W3>W1 and W3>W2 are satisfied, W3 is 1.14 to 1.18 mm, A coil device characterized in that the ratio of the number of turns of the first coil portion to the second coil portion is within a range of 0.75 to 1 / 0.

75.

2. a first connection position of the first terminal connected to the first wire and a second connection position of the second terminal connected to the first wire are disposed on a first direction side of the first flange portion along a second axis perpendicular to the first axis, The coil device according to claim 1, wherein a third connection position for connecting the third terminal to the second wire and a fourth connection position for connecting the fourth terminal to the second wire are arranged on the first direction side along the second axis of the second flange portion.

3. the first connection position is disposed on the opposite side of the second connection position across a connection portion where the first flange portion is connected to the winding core portion in a third axis direction perpendicular to the first axis and the second axis, The coil device according to claim 2 , wherein the third connection position is located on the opposite side of the fourth connection position across a connection portion where the second flange portion is connected to the winding core portion in the third axial direction.

4. the first wire is bent at a first winding end portion, which is one end of the first coil portion, toward the first connection position so as to be away from the first coil portion; the first wire is bent at a second winding end portion, which is the other end of the first coil portion, toward the second connection position so as to be away from the first coil portion; the second wire is bent at a third winding end, which is one end of the second coil portion, toward the third connection position so as to be away from the second coil portion; The coil device according to claim 2 or 3, wherein the second wire is bent at a fourth winding end, which is the other end of the second coil portion, toward the fourth connection position so as to move away from the second coil portion.

5. The first terminal is a first terminal first portion having a plane perpendicular to the second axis; and a first terminal second portion disposed on the opposite side of the first terminal first portion across the first flange portion in the second axis direction, the first terminal second portion having a plane parallel to the first terminal first portion; a first connecting portion connecting the first terminal first portion and the first terminal second portion, The second terminal is a second terminal first portion having a plane perpendicular to the second axis; and a second terminal second portion disposed on the opposite side of the second terminal first portion across the first flange portion in the second axis direction, the second terminal second portion having a plane parallel to the second terminal first portion; a second connecting portion connecting the second terminal first portion and the second terminal second portion, The third terminal is a third terminal first portion having a plane perpendicular to the second axis; and a third terminal second portion disposed on the opposite side of the third terminal first portion across the second axial direction from the second flange portion, the third terminal second portion having a plane parallel to the third terminal first portion; a third connection portion connecting the third terminal first portion and the third terminal second portion, The fourth terminal is a fourth terminal first portion having a plane perpendicular to the second axis; and a fourth terminal second portion disposed on the opposite side of the second flange portion from the fourth terminal first portion in the second axis direction, the fourth terminal second portion having a plane parallel to the fourth terminal first portion; 5. The coil device according to claim 2, further comprising: a fourth connecting portion that connects the fourth terminal first portion and the fourth terminal second portion.

6. A coil device as described in any one of claims 2 to 5, wherein the first terminal second portion, the second terminal second portion, the third terminal second portion, and the fourth terminal second portion are arranged on the same plane perpendicular to the second axis on the second direction side opposite to the first direction along the second axis, and are configured to be mountable.

7. The coil device according to any one of claims 2 to 6, wherein the winding core portion has a flat surface on the side facing the first direction along the second axis.

8. 8. The coil device according to claim 1, further comprising a plate core that magnetically connects the first flange portion and the second flange portion.

9. The coil device according to claim 8 , wherein the planar core has a flat bottom surface facing the winding core portion.

10. The first wire has a first pull-out portion that is pulled out from a first winding end that is one end of the first coil portion and connects to the first terminal, and a second pull-out portion that is pulled out from a second winding end that is the other end of the first coil portion and connects to the second terminal, the second wire has a third lead-out portion that is drawn out from a third winding end that is one end of the second coil portion and connects to the third terminal, and a fourth lead-out portion that is drawn out from a fourth winding end that is the other end of the second coil portion and connects to the fourth terminal, the first winding end is located in the first outer winding portion of the first coil portion, the second winding end is located in the first inner winding portion of the first coil portion, the third winding end is located in the second inner winding portion of the second coil portion, The coil device according to any one of claims 1 to 9, wherein the fourth winding end is located in the second outer winding portion of the second coil part.

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