Coil device

Abstract

To provide a coil device capable of improving the difference in operating characteristics of a coil depending on a mounting direction.SOLUTION: On a winding core part 14 on one side of a pair of winding core parts, a wire 100 is wound from one side along an X-axis starting from the outside and ending on the outside. On the winding core part 14 as well on the other side, another wire 110 is similarly wound from one side along the X-axis starting from the outside and ending on the outside.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a coil device suitably used for, for example, a common mode filter (common mode choke coil).

Background Art

[0002] As a common mode filter, for example, a coil device in which two wires are wound around an annular core as shown in Patent Document 1 is known. Such EMC components such as common mode filters are mounted on electronic devices to reduce noise.

[0003] In EMC components, variations in noise reduction characteristics are not preferable. However, in a conventional coil device as shown in Patent Document 1, it has been found that differences in the operating characteristics of the coil occur due to differences in the mounting direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of such a situation, the present invention has been made, and an object thereof is to provide a coil device capable of improving differences in the operating characteristics of a coil due to the mounting direction.

Means for Solving the Problems

[0006] To achieve the above object, a coil device according to a first aspect of the present invention is a pair of winding core portions arranged substantially parallel to each other along a first axis at a predetermined interval along a second axis, and wires wound along the first axis around each of the winding core portions, The positions of the start and end points of the first winding of each wire located on one side along the first axis belong to either the outer region or the inner region of each bobbin core portion as viewed from the first axis direction. The positions of the start and end points of the second winding of each wire located on the other side along the first axis belong to the region on the same side as the region to which the positions of the start and end points of the first winding belong.

[0007] In the coil device according to the first aspect of the present invention, for example, in one of the pair of bobbin cores, the wire is wound starting from the outside from one side along the first axis and ends winding on the outside, and in the other bobbin core as well, similarly, another wire is wound starting from the outside from one side along the first axis and ends winding on the outside. Or, in one of the pair of bobbin cores, the wire is wound starting from the inside from one side along the first axis and ends winding on the inside, and in the other bobbin core as well, similarly, another wire is wound starting from the inside from one side along the first axis and ends winding on the inside.

[0008] In the first aspect of the present invention, the "start and end points of winding" of the wire refer to the position where the wire wound around the bobbin core in a coil shape starts winding for the first time and contacts the bobbin core, or the position where the wire wound around the bobbin core in a coil shape ends winding and separates from the contact with the bobbin core. After the wire is wound around the bobbin core, it is difficult to determine whether it is the starting point of winding or the ending point of winding.

[0009] According to the new findings of the present inventors, it has been found that by making the start and end points of winding of the wires wound around the pair of bobbin cores belong to either the outer region or the inner region, the difference in operating characteristics due to the mounting direction can be improved. Although the reason is not necessarily clear, it can be explained as follows, for example. The start and end points of winding of the wires wound around the pair of bobbin cores belong to either the outer region or the inner region.

[0010] In a conventional coil device, when starting to wind a wire from the outside to the core part, it generally ended winding on the inside, and conversely, when starting to wind a wire from the inside to the core part, it generally ended winding on the outside. This is presumably because the connection part of the lead of the wire at the start of winding and the connection part of the lead of the wire at the end of winding were all positioned on the same side to facilitate the connection.

[0011] However, it has been found that when reversing the start and end of winding of the wire wound around the core part between the outside and the inside in this way, the symmetry of the leakage magnetic flux cannot be maintained between the start side and the end side of winding. It was speculated that this asymmetry of the leakage magnetic flux might be having an adverse effect on the characteristics of the coil device, and thus the present invention was completed.

[0012] That is, in the invention according to the first aspect of the present invention, the start and end points of winding of the wire wound around a pair of core parts respectively belong to either the outer region or the inner region. By configuring in this way, it is considered that the symmetry of the leakage magnetic flux can be ensured between the start side and the end side of winding, and as a result, the difference in operating characteristics depending on the mounting direction can be improved.

[0013] In the first aspect of the present invention, the inner region of the core part is the half region closer to the other core part when viewing the core part from the first axial direction. Also, the outer region of the core part is the half region on the side opposite to the side closer to the other core part when viewing the core part from the first axial direction.

[0014] When viewed from the first axial direction, the first start / end points and the second start / end points located within the same-side region (inner region or outer region) may be displaced from each other along the circumferential direction of the core part. It is easier to wind the wire and the arrangement of the connection part is also simpler when the first start / end points and the second start / end points located within the same-side region (inner region or outer region) are arranged at different positions rather than at the same position along the circumferential direction.

[0015] Preferably, the coil device according to the first aspect of the present invention A first connection part to which lead parts respectively extending from the start and end points of the first winding of each of the wires are connected, and a second connection part to which lead parts respectively extending from the start and end points of the second winding of each of the wires are connected, and further has: Along a third axis intersecting both the first axis and the second axis, the first connection part and the second connection part are located on opposite sides of each other when viewed from the first axis direction.

[0016] By positioning the first connection part and the second connection part on opposite sides along the third axis, it becomes easier to make the start and end points of the wires wound around the pair of bobbin parts belong to either the outer region or the inner region.

[0017] Preferably, one end of the two bobbin parts along the first axis is integrally connected by a first flange part, The other end of the two bobbin parts along the first axis is integrally connected by a second flange part. The first connection part provided on the first flange part and the second connection part provided on the second flange part are located on opposite sides of each other along the third axis when viewed from the first axis direction.

[0018] The first connection part may be attached to the first flange part by plating, or may be joined to the first flange part by adhesion or the like as a part of a metal terminal. Similarly, the second connection part may be attached to the second flange part by plating, or may be joined to the second flange part by adhesion or the like as a part of a metal terminal. joined.

[0019] Preferably, each of the first connection parts is provided on each of the first terminal electrodes, and each first terminal electrode is provided with a first dummy connection part on the side opposite to the first connection part along the third axis. Each of the second connection parts is provided on each of the second terminal electrodes, and each second terminal electrode is provided with a second dummy connection part on the side opposite to the second connection part along the third axis. More preferably, the first dummy connection part and the second connection part have mounting-side protruding pieces whose tips are located on substantially the same plane.

[0020] By configuring in this way, the mounting of the coil device onto a wiring board or the like becomes easy without tilting the coil device.

[0021] Preferably, the second dummy connection portion and the first connection portion have anti-mounting side protruding pieces whose tips are located on substantially the same plane. By configuring in this way, it becomes easy to mount a cover member having a flat surface that is substantially parallel to the mounting surface on the opposite side of the mounting surface on the anti-mounting side protruding piece. As a result, the pick-up and conveyance of the coil device becomes easy.

[0022] Preferably, the anti-mounting side protruding piece has a pair of bent pieces that respectively surround from both sides along the second axis each lead portion that is drawn out from each first winding start / end point of the wire and extends along the first axis. Also preferably, the mounting side protruding piece has a pair of bent pieces that respectively surround from both sides along the second axis each lead portion that is drawn out from each second winding start / end point of the wire and extends along the first axis.

[0023] By configuring in this way, the connection work of each lead portion becomes easy, the bending of the wire in the vicinity of the lead portion can be minimized, the stress acting on the lead portion is reduced, and the connection strength of the lead portion is improved.

[0024] The coil device according to the second aspect of the present invention is a pair of bobbin portions that are arranged substantially parallel along the first axis at a predetermined interval along the second axis, a wire wound along the first axis around each of the bobbin portions, a first connection portion to which the first lead portions of the respective wires located on one side along the first axis are respectively connected, a second connection portion to which the second lead portions of the respective wires located on the other side along the first axis are respectively connected, and is a coil device having along a third axis that intersects both the first axis and the second axis, the first connection portion and the second connection portion are located on opposite sides of each other when viewed from the first axis direction.

[0025] In the coil device according to the second aspect of the present invention, by positioning the first connection part and the second connection part on opposite sides along the third axis, it becomes easier to make the winding start and end points of the wire wound around each of the pair of core parts belong to either the outer region or the inner region.

Brief Description of the Drawings

[0026]

Figure 1A

Figure 1B

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 7A

Figure 7B

Figure 7C

Figure 8A

Figure 8B

[0027] Hereinafter, the present invention will be described based on the embodiments shown in the drawings. In the drawings, the X-axis (first axis), Y-axis (second axis), and Z-axis (third axis) are substantially perpendicular to each other.

[0028] First Embodiment A coil device 1 according to an embodiment of the present invention shown in FIG. 1A is suitably used, for example, as a common mode filter (common mode choke coil), and includes a core 10, wires 100 and 110, and terminal electrodes 60 and 80. In the present embodiment, the coil device 1 further includes a cover 50.

[0029] As shown in FIG. 2, the core 10 has two winding core portions 12 and 14 that are arranged in parallel along the X-axis direction with a predetermined interval in the Y-axis direction. One first flange portion 16a is connected to one end of the two winding core portions 12 and 14 along the X-axis, and the other second flange portion 16b is connected to the other end of the two winding core portions 12 and 14 along the X-axis. In the present embodiment, the core 10 is an annular core and may be integrally formed or may be assembled into an annular core by combining molded bodies.

[0030] Each of the bobbin cores 12 and 14 has a coil portion formed by winding wires 100 and 110 respectively. The wires 100 and 110 are not particularly limited, and for example, flat wires, round wires, stranded wires, Litz wires, braided wires, or other conductive core wires made of copper or the like, or wires in which these conductive core wires are insulated and coated can be used. The wire diameter of the wires 100 and 110 is not particularly limited, but in this embodiment, it has an outer diameter larger than the plate thickness of the terminal electrodes 60 and 80, and for example, has an outer diameter about 1.2 to 5 times the plate thickness of the terminal electrodes 60 and 80.

[0031] In this embodiment, the wires 100 and 110 are wound around the respective bobbin cores 12 and 14 in the same number of turns in mutually reverse rotation directions when viewed from the X-axis direction. For example, the wire 100 is wound clockwise around one bobbin core 12, and the wire 110 is wound counterclockwise around the other bobbin core 14. Two terminal electrodes 60 and 80 are respectively mounted on the respective flange portions 16a and 16b.

[0032] A first lead portion 101a, which is one end (the left side in FIG. 2) of the wire 100 wound around one bobbin core 12 arranged on the front side along the Y-axis in FIG. 2, is connected to the front-side terminal electrode 60 arranged on one first flange portion 16a. Also, a second lead portion 101b, which is the other end (the right side in FIG. 2) of the wire 100, is connected to the front-side terminal electrode 80 arranged on the other second flange portion 16b. Similarly, a first lead portion 111a, which is one end of the wire 110 wound around the other bobbin core 14 arranged on the back side along the Y-axis in FIG. 2, is connected to the back-side terminal electrode 60 arranged on one first flange portion 16a, and a second lead portion 111b, which is the other end of the wire 110, is connected to the back-side terminal electrode 80 arranged on the other second flange portion 16b.

[0033] The flange portions 16a and 16b arranged on opposite sides along the X-axis of the core 10 have a point-symmetrical (or line-symmetrical) configuration with respect to each other. Each of the flange portions 16a and 16b has an outer end face 24 located at an end along the X-axis of the core 10, an inner end face 25 located on the opposite side thereof, a mounting-side lower face 22, an upper face 20 located on the opposite side thereof, and first and second side faces 26 and 28 located at both ends along the Y-axis of the core 10.

[0034] The outer end face 24 of each of the flange portions 16a and 16b has a central outer end face 24a located at the central portion in the Y-axis direction and side outer end faces 30 and 32 located on both sides in the Y-axis direction thereof. The side outer end faces 30 and 32 are slightly recessed in a stepped manner along the X-axis from the central outer end face 24a, but these outer end faces 24a, 30, and 32 are substantially parallel to a plane including the Z-axis and the Y-axis. The step height along the X-axis between the central outer end face 24a and the side outer end face 30 (or 32) may be 0, but is preferably equal to or less than the plate thickness of the terminal electrodes 60 or 80.

[0035] One X-axis end or the other X-axis end of each of the winding core portions 12 and 14 is integrally connected to each of the inner end faces 25 of the flange portions 16a and 16b, respectively. A groove portion 38 extending along the Z-axis from the upper face 20 of the flange portions 16a and 16b toward the mounting-side lower face 22 is formed at the central portion in the Y-axis direction of the inner end faces 25 of the flange portions 16a and 16b. The groove portion 38 is located in the middle of the portion where the winding core portions 12 and 14 are connected to the flange portions 16a and 16b.

[0036] As shown in FIG. 3, a chamfered portion 25α is formed from below the Z-axis of the inner end face 25 of each of the flange portions 16a and 16b toward the mounting-side lower face 22, and a chamfered portion 24α is also formed from below the Z-axis of the outer end face 24 toward the mounting-side lower face 22. The presence of these chamfered portions 24α and 25α facilitates the molding (die cutting) of the core 10.

[0037] As shown in FIG. 3, in the present embodiment, the upper surfaces 20 of the flange portions 16a and 16b are lower than the maximum height along the Z-axis of the core portion 12 by a predetermined step height (preferably 0.5 to 5 times the plate thickness of the terminal electrodes 60 or 80), but the step height may not be provided. Further, the upper surfaces 20 of the flange portions 16a and 16b may be configured to be higher than the maximum height along the Z-axis of the core portion 12.

[0038] As shown in FIG. 2, at both ends of each of the flange portions 16a and 16b in the Y-axis direction, the lower ends of the Z-axis of the first side surface 26 and the second side surface 28 are cut away, and locking receiving portions 34 and 36 are respectively formed. Locking claws 54 and 55 formed at the lower ends of the respective legs 52 and 53 provided at the four corners of the cover 50 are detachably engaged with the respective locking receiving portions 34 and 36.

[0039] In order to form the notch-shaped locking receiving portions 34 and 35 below both ends of each of the flange portions 16a and 16b in the Y-axis direction, the width of the mounting-side lower surface 22 in the Y-axis direction is formed to be narrower than the width of the upper surface 20 in the Y-axis direction. However, the width of the mounting-side lower surface 22 in the Y-axis direction is larger than the width of the central outer end surface 24a in the Y-axis direction, and is determined so as to ensure a sufficient dimension for the width of the side outer end surfaces 30 and 32 on the mounting-side lower surface 22 side.

[0040] As shown in FIG. 2, the cover 50 has a flat lid portion 51 and legs 52 and 53 that branch along the X-axis from both ends of the lid portion 51 along the Y-axis and then project downward along the Z-axis. Locking claws 54 and 55 described above are integrally formed at the lower ends of the respective legs 52 and 53 along the Z-axis.

[0041] Further, the cover 50 also has a pair of convex block portions 58 that project along both sides of the X-axis at the lower part near the center of the lid portion 51 along the Y-axis. Each convex block portion 58 can abut against the central portion of the upper surface 20 of each of the flange portions 16a and 16b along the Y-axis. A plate-shaped partition portion 56 that extends along the X-axis is integrally formed on the lower surface of the lid portion 51 located at the center along the Y-axis so as to connect the pair of convex block portions 58.

[0042] The lower end of the plate-shaped partition portion 56 along the Z-axis protrudes further downward along the Z-axis than the lower end of the convex block portion 58 along the Z-axis. Both side ends of the plate-shaped partition portion 56 along the X-axis are slidably attached up and down to the groove portions 38 formed on the inner end surfaces 25 of the flange portions 16a and 16b. The partition portion 56 can effectively prevent the wires 100 and 110 wound around the respective core portions 12 and 14 in a coiled shape from contacting each other, and can ensure their insulation. Note that the upper surface of the lid portion 51 of the cover 50 is flat, and it can be adsorbed by an adsorption nozzle or the like, facilitating the conveyance of the coil device 1.

[0043] The cover 50 is made of a non-magnetic material such as resin, for example, but the resin may contain a magnetic material such as a metal magnetic body or ferrite. Also, the cover 50 may be made of a magnetic material such as a metal magnetic body or ferrite, similar to the core 10. When the cover 50 is made of a magnetic material or when the cover 50 contains a magnetic material, the cover 50 may form a closed magnetic circuit together with the core 10.

[0044] As shown in FIG. 5, the terminal electrode 60 and the terminal electrode 80 have the same shape and the same size, respectively. However, for the terminal electrode 60 attached to the first flange portion 16a shown in FIG. 2 and the terminal electrode 80 attached to the second flange portion 16b, the arrangement relationship between the connection portion and the dummy connection portion is reversed in the up and down directions along the Z-axis. Each of the terminal electrodes 60 and 80 has a terminal main piece (terminal main portion) 62 and 82, a connection portion 70 and 90, and a dummy connection portion 78 and 98, respectively, and these are formed by bending a single metal piece with a substantially constant plate thickness. Also, the dummy connection portions 78 and 98 are arranged on the opposite side along the Z-axis to the connection portions 70 and 90 with the terminal main pieces 62 and 82 interposed therebetween, and have the same shape and the same size as the connection portions 70 and 90.

[0045] In this embodiment, the connection portions 70, 90 and the dummy connection portions 78, 98 have a base piece 68, 88 and a protruding piece 76, 96. The connection portion 70 of the terminal electrode 60 is located at the upper part in the Z-axis direction and is the portion where the first lead portion 101a of the wire 100 shown in FIG. 4 or the first lead portion 111a of the wire 110 is connected. Also, as shown in FIG. 5, the connection portion 90 of the terminal electrode 80 is the portion where the second lead portion 101b of the wire 100 is connected as shown in FIG. 3 and is also the portion where the second lead portion 111b of the wire 110 shown in FIG. 4 is connected. Note that the first lead portions 101a, 111a and the second lead portions 101b, 111b are not connected to the respective dummy connection portions 78, 98.

[0046] As shown in FIG. 3, the base pieces 68, 88 located on the upper side in the Z-axis direction of the terminal electrodes 60, 80 are bent and formed substantially perpendicularly from the upper ends along the Z-axis of the terminal main pieces 62, 82 so as to be installed along the upper surfaces 20, 20 of the respective flange portions 16a, 16b. Note that the base pieces 68, 88 may be adhered to the upper surfaces 20, 20 of the respective flange portions 16a, 16b, but may be engaged with the upper surfaces 20, 20 without adhesion, or may be arranged to face the upper surfaces 20, 20 of the respective flange portions 16a, 16b with a certain interval.

[0047] Also, the other base pieces 68, 88 located on the lower side in the Z-axis direction of the terminal electrodes 60, 80 are bent and formed substantially perpendicularly from the lower ends along the Z-axis of the terminal main pieces 62, 82 so as to be installed along the mounting-side lower surfaces 22, 22 of the respective flange portions 16a, 16b. Note that the base pieces 68, 88 may be adhered to the mounting-side upper surfaces 22, 22 of the respective flange portions 16a, 16b, but may be engaged with the mounting-side lower surfaces 22, 22 without adhesion, or may be arranged to face the mounting-side lower surfaces 22, 22 of the respective flange portions 16a, 16b with a certain interval.

[0048] As shown in FIG. 5, on both sides of each base piece 68 of the terminal electrode 60 along the Y-axis, protruding pieces 76 are integrally bent and formed so as to protrude obliquely outward (upper side or lower side) of the Z-axis. Each protruding piece 76 is inclined at an acute angle with respect to the base piece 68 such that its tip approaches above the base piece 68. As shown in FIG. 4, it is possible to caul the lead part 101a or 111a on the base piece 68 of the connection part 70 (upper surface in the Z-axis direction) between the pair of protruding pieces 76. The first lead 101a (111a) of the wire 100 (110) is connected to each base piece 68 with solder 5 or the like while being sandwiched between the pair of protruding pieces 76.

[0049] Also, as shown in FIG. 5, similar to the terminal electrode 60, on both sides of each base piece 88 of the terminal electrode 80 along the Y-axis, protruding pieces 96 are integrally bent and formed so as to protrude obliquely outward (upper side or lower side) of the Z-axis. Each protruding piece 96 is inclined at an acute angle with respect to the base piece 88 such that its tip approaches above the base piece 88. Also, it is possible to caul the lead part 101b or 111b on the base piece 88 of the connection part 90 (lower surface in the Z-axis direction) between the pair of protruding pieces 96. The second lead 101b (111b) of the wire 100 (110) is connected to each base piece 88 with solder 5 or the like while being sandwiched between the pair of protruding pieces 96.

[0050] As shown in FIG. 3, each terminal main piece 62, 82 is arranged to face the outer end surfaces 24, 24 of the respective flange parts 16a, 16b, and is adhered to the side outer end surfaces 30, 32 located on both sides in the Y-axis direction of the outer end surfaces 24 of the respective flange parts 16a, 16b shown in FIG. 2 using an adhesive.

[0051] The terminal electrodes 60 and 80 are made of a metal such as tough pitch steel, phosphor bronze, brass, iron, nickel, nickel alloy, or stainless steel. The terminal electrodes 60 and 80 can be integrally formed by punching a conductive metal plate and bending and forming it without folding, for example. Further, it is preferable that plating films such as tin or an alloy containing tin are formed on the connection portions 70 and 90 and the dummy connection portions 78 and 98 as solder adhesion strengthening layers.

[0052] Next, the relationship among the wires 100 and 110, the winding core portions 12 and 14, and the terminal electrodes 60 and 80 will be described in detail. Note that the relationship among the wire 110, the winding core portion 14, and the terminal electrodes 60 and 80 is the same as the relationship among the wire 100, the winding core portion 12, and the terminal electrodes 60 and 80, except that the wire 110 is wound around the winding core portion 14 in the reverse rotation direction, and part of the description thereof will be omitted.

[0053] As shown in FIG. 1A, a wire 100 is wound around the winding core portion 12 in a plurality of turns along the X-axis in the clockwise direction. The tip of the first lead portion 101a, which is one end of the wire 100 in the X-axis direction, is connected to the upper base piece 68 of the terminal electrode 60 disposed on the front side along the Y-axis of the first flange portion 16a, and extends in the X-axis direction between the pair of protruding pieces 76. In the present embodiment, the wire 100 is inclined downward to the right from the tip of the first lead portion 101a toward the winding core portion 12 and contacts the winding core portion 12 at the first winding start / end point 102a and is wound around the winding core portion 12 in the same direction.

[0054] After the wire 100 is wound around the winding core portion 12 in a plurality of turns along the X-axis in the clockwise direction, the second lead portion 101b of the wire 100 is pulled out obliquely from the winding core portion 12 at the second winding start / end point 102b of the wire and is connected to the lower base piece 88 of the terminal electrode 80 shown in FIG. 3. On the lower surface of the base piece 88, the tip of the second lead portion 101b of the wire 100 is pulled out along the X-axis.

[0055] Note that the first start / end point 102a is the part where the winding of the coil begins when the wire 100 is wound around the core part 12 starting from the first lead part 101a. When the wire 100 is wound around the core part 12 starting from the second lead part 101b shown in FIG. 3, it is the part where the winding of the coil ends. Also, the second start / end point 102b is the part where the winding of the coil ends when the wire 100 is wound around the core part 12 starting from the first lead part 101a, and it is the part where the winding of the coil begins when the wire 100 is wound around the core part 12 starting from the second lead part 101b.

[0056] In this embodiment, the first start / end point 102a, which is the start or end of the winding of the wire 100 wound around the core part 12, is positioned to belong to the outer region 12a from the straight line along the Z-axis including the central axis O1 of the coil shown in FIG. 4. Also, the second start / end point 102b, which is the start or end of the winding of the wire 100 wound around the core part 12, is also positioned to belong to the outer region 12a. However, the first start / end point 102a and the second start / end point 102b are different in position along the Z-axis and are positioned in opposite directions with respect to the line parallel to the Y-axis including the central axis O1.

[0057] Note that the central axis O1 of the coil is the center line along the X-axis of the core part 12 shown in FIG. 1A. Also, the inner region 12b of the core part 12 is the half region closer to the other core part 14 when the core part 12 is viewed from the X-axis direction. Further, the outer region 12a of the core part 12 is the half region on the side opposite to the side closer to the other core part 14 when the core part 12 is viewed from the X-axis direction.

[0058] Similarly, as shown in FIG. 1A, a wire 110 is wound around the core part 14 in a counterclockwise direction along the X-axis in a plurality of turns (the same number of turns as the wire 100). The tip of the first lead part 111a, which is one end of the wire 110 in the X-axis direction, is connected to the upper base piece 68 of the terminal electrode 60 arranged on the back side along the Y-axis of the second flange part 16b and extends in the X-axis direction between the pair of protruding pieces 76. In this embodiment, the wire 110 is inclined downward to the left from the tip of the first lead part 111a toward the core part 12 and contacts the core part 14 at the first start / end point 112a and is wound around the core part 14 in the same direction.

[0059] After the wire 110 is wound around the bobbin core 14 in a plurality of turns along the X-axis in the counterclockwise direction, as shown in FIG. 4, the second lead portion 111b of the wire 110 is pulled out obliquely and connected toward the base piece 88 below the terminal electrode 80, leaving the bobbin core 12 at the second winding start / end point 112b of the wire. On the lower surface of the base piece 88, the tip of the second lead portion 111b of the wire 110 is pulled out along the X-axis.

[0060] Note that the first winding start / end point 112a is the portion where the winding of the coil starts when the wire 100 is wound around the bobbin core 14 from the first lead portion 111a, and is the portion where the winding of the coil ends when the wire 110 is wound around the bobbin core 14 from the second lead portion 111b. Also, the second winding start / end point 112b is the portion where the winding of the coil ends when the wire 110 is wound around the bobbin core 14 from the first lead portion 111a, and is the portion where the winding of the coil starts when the wire 110 is wound around the bobbin core 14 from the second lead portion 111b.

[0061] In the present embodiment, the first winding start / end point 112a, which is the start or end of the winding of the wire 110 wound around the bobbin core 14, is positioned so as to belong to the outer region 14a from the straight line along the Z-axis including the central axis O2 of the coil shown in FIG. 4. Also, the second winding start / end point 112b, which is the start or end of the winding of the wire 110 wound around the bobbin core 14, is also positioned so as to belong to the outer region 14a. However, the first winding start / end point 102b and the second winding start / end point 112b are different in position along the Z-axis and are positioned in opposite directions with respect to the line parallel to the Y-axis including the central axis O2. position.

[0062] Note that the central axis O2 of the coil is the center line along the X-axis of the bobbin core 14 shown in FIG. 1A. Also, the inner region 14b of the bobbin core 14 is the half region closer to the other bobbin core 12 when the bobbin core 14 is viewed from the X-axis direction. Also, the outer region 14a of the bobbin core 14 is the half region on the side opposite to the side closer to the other bobbin core 12 when the bobbin core 14 is viewed from the X-axis direction.

[0063] In the coil device 1 according to the present embodiment, for example, in one of the pair of core parts 12 and 14, the wire 100 starts to be wound from one side along the X-axis from the outside and ends winding on the outside. Similarly, in the other core part 14, another wire 110 starts to be wound from one side along the X-axis from the outside and ends winding on the outside.

[0064] That is, the first winding start / end points 102a and 102b of the wire 100 wound around the core part 12 are made to belong to the outer region 12a, and the first winding start / end points 112a and 112b of the wire 110 wound around the core part 14 are made to belong to the outer region 14a. By configuring in this way, the symmetry of the leakage magnetic flux can be ensured between the winding start side and the winding end side, and as a result, the difference in the operating characteristics depending on the mounting direction can be improved.

[0065] Also, in the present embodiment, when viewed from the X-axis direction, the first winding start / end points 102a (112a) and the second winding start / end points 102b (112b) located in the outer regions 12a (14a) on the same side are displaced from each other along the circumferential direction of the core part 12 (14). It is easier to wind the wire 100 (110) and the arrangement of the connection part 70 (90) is also simplified by arranging the first winding start / end points 102a (112a) and the second winding start / end points 102b (112b) located in the outer regions 12a (14a) on the same side at different positions rather than at the same position along the circumferential direction.

[0066] Furthermore, in the present embodiment, as shown in FIG. 4, the first connection parts 70, 70 to which the lead parts 101a, 111a extending from the first winding start / end points 102a, 112a are connected, and the second connection parts 90, 90 to which the lead parts 101b, 111b extending from the second winding start / end points 102b, 112b are connected are located on opposite sides along the Z-axis.

[0067] By positioning the first connection portions 70, 70 and the second connection portions 90, 90 on opposite sides along the Z-axis, it becomes easier to make the winding start and end points 102a, 102b, 112a, 112b of the wires 100, 110 wound around the pair of bobbin portions 12, 14 belong to the respective outer regions 12a and 14a.

[0068] Furthermore, in the present embodiment, each of the first connection portions 70, 70 is provided in each of the first terminal electrodes 60, 60, and each of the first terminal electrodes 60, 60 is provided with first dummy connection portions 78, 78 on the side opposite to the first connection portions 70, 70 along the Z-axis. Also, each of the second connection portions 90, 90 is provided in each of the second terminal electrodes 80, 80, and each of the second terminal electrodes 80, 80 is provided with a second dummy connection portion 98 on the side opposite to the second connection portions 90, 90 along the Z-axis. The first dummy connection portions 78, 78 and the second connection portions 90, 90 have protruding pieces 76, 96 on the mounting side where the tips are located on substantially the same plane. By configuring in this way, without tilting the coil device 1, it becomes easy to mount the coil device 1 on a wiring board or the like.

[0069] Also, the second dummy connection portions 98, 98 and the first connection portions 70, 70 have protruding pieces 76, 96 on the non-mounting side where the tips are located on substantially the same plane. By configuring in this way, it becomes easy to mount a cover member 50 having a flat surface substantially parallel to the mounting surface on the opposite side of the mounting surface on the protruding pieces 76, 96 on the non-mounting side. As a result, pick-up conveyance of the coil device 1 etc. becomes easy. Also, in the present embodiment, when not having the cover 50, it can be used without problem by mounting either the upper surface or the lower surface in the Z-axis direction of the coil device 1 on a circuit board or the like.

[0070] Furthermore, in the present embodiment, the tips of the lead portions 101a, 111a, 101b, and 111b each extending along the X-axis of the wires 100 and 110 are provided with a pair of bent pieces that surround from both sides along the Y-axis, which the protruding pieces 76 and 96 have. By configuring in this way, the connection wire operation of each lead portion 101a, 111a, 101b, and 111b becomes easy, and the bending of the wires 100 and 110 near the lead portions 101a, 111a, 101b, and 111b can be minimized. The stress acting on the lead portions 101a, 111a, 101b, and 111b can be reduced, and the connection strength of the lead portions 101a, 111a, 101b, and 111b to the terminal electrodes 60 and 80 is improved.

[0071] In the present embodiment, the respective wires 100 and 110 are wound around the respective core portions 12 and 14 in a line-symmetric manner to each other, and can preferably function as a common-mode filter.

[0072] Second Embodiment The coil device 2 according to another embodiment of the present invention shown in FIG. 1B is a modified example of the coil device 1 according to the above-described first embodiment, and has the same configuration and effects except as described below. Hereinafter, mainly, the parts different from the coil device 1 according to the first embodiment will be described, and the description of the overlapping parts will be omitted.

[0073] As shown in FIG. 1B, in the present embodiment, the wires 100 and 110 are wound around the core portions 12 and 14 in the opposite direction to the first embodiment.

[0074] That is, as shown in FIG. 1B, in the coil device 1 according to the present embodiment, for example, in one of the pair of core portions 12 and 14, the wire 100 starts winding from the inner side from one side along the X-axis and ends winding inside, and in the other core portion 14 as well, similarly, another wire 110 starts winding from the inner side from one side along the X-axis and ends winding inside.

[0075] That is, the first winding start / end points 102a and the second winding start / end points 102b of the wire 100 wound around the core part 12 are made to belong to the inner region 12b shown in FIG. 4, and the first winding start / end points 112a and the second winding start / end points 112b of the wire 110 wound around the core part 14 are made to belong to the inner region 14b shown in FIG. 4. By configuring in this way, also in this embodiment, symmetry of leakage magnetic flux can be ensured between the winding start side and the winding end side, and as a result, differences in operating characteristics depending on the mounting direction can be improved.

[0076] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0077] For example, in the above-described embodiments, the terminal electrodes 60 and 80 are formed of conductive plate pieces, and the connection parts 70 and 90 and the terminal main parts 62 and 82 connected to the connection parts 70 and 90 are integrally formed on the conductive plate pieces, but it is not limited thereto. For example, the terminal electrodes including at least the connection parts 70 and 90 may be formed as plating films formed on the surfaces of the flange parts 16a and 16b.

[0078] Also, in the above-described embodiments, as shown in FIG. 4, the first leads 101a and 111a and the second lead parts 101b and 111b of the wires 100 and 110 are connected to the terminal electrodes 60 or 80 by the cylinder 5, but they may be connected by methods such as laser welding, thermocompression bonding, arc welding, and resistance welding.

[0079] Furthermore, the use of the coil device 1 is not limited to a common mode filter (common mode choke coil), etc., and it can also be used as a balun transformer, pulse transformer, choke coil, signal transformer, winding product, etc. Also, in the above-described embodiments, the wires 100 and 110 are wound around the respective core parts 12 and 14 in the same number of turns in mutually reverse rotation directions when viewed from the X-axis direction, but they may be wound in different numbers of turns.

Example

[0080] Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples.

[0081] Example 1 For the coil device 1 shown in FIG. 1A (the cover 50 is not attached), computer simulations were performed on each leakage magnetic flux when the direction of current flow was changed.

[0082] FIG. 6A shows the results of performing a simulation of leakage magnetic flux by flowing current in the order of the terminal 80 indicated by reference sign b1, the terminal 80 indicated by reference sign c1, the terminal 60 indicated by reference sign d1, and the terminal 60 indicated by reference sign a1 from the terminal 60 indicated by reference sign a1 for the coil device 1 according to the first embodiment. Further, FIG. 6B shows the results of performing a simulation of leakage magnetic flux assuming a case where the mounting direction is reversed by rotating the arrangement of the terminals of the coil device 1 shown in FIG. 6A so as to be reversed about the Z axis. That is, in FIG. 6B, current is flowed in the order of the terminal 60 indicated by reference sign d1, the terminal 60 indicated by reference sign a1, the terminal 80 indicated by reference sign b1, and the terminal 80 indicated by reference sign c1 from the terminal 80 indicated by reference sign c1, and the result of the simulation of leakage magnetic flux is shown.

[0083] Further, FIG. 6C shows the results of performing a simulation of leakage magnetic flux assuming a case where the mounting surface is reversed by rotating the arrangement of the terminals of the coil device 1 shown in FIG. 6A so as to be reversed about the Y axis. That is, in FIG. 6C, current is flowed in the order of the terminal 60 indicated by reference sign a1, the terminal 60 indicated by reference sign d1, the terminal 80 indicated by reference sign c1, and the terminal 80 indicated by reference sign b1 from the terminal 80 indicated by reference sign b1, and the result of the simulation of leakage magnetic flux is shown.

[0084] In FIGS. 6A to 6C, B1, B2, B3, and B4 respectively represent the magnetic flux density of the leakage magnetic flux, and the magnetic flux density is highest for B1 and gradually decreases for B2, B3, and B4.

[0085] Example 2 For the coil device 2 shown in FIG. 1B, computer simulations were performed on each leakage magnetic flux when the direction of current flow was changed.

[0086] FIG. 7A shows the result of performing a simulation of leakage magnetic flux by passing current through the coil device 2 according to the second embodiment in the order of the terminal 60 indicated by reference sign a2, the terminal 80 indicated by reference sign b2, the terminal 80 indicated by reference sign c2, and the terminal 60 indicated by reference sign d2. Further, FIG. 7B shows the result of performing a simulation of leakage magnetic flux assuming a case where the mounting direction is reversed by rotating the arrangement of the terminals of the coil device 2 shown in FIG. 7A so as to be reversed about the Z axis. That is, in FIG. 7B, the current is passed through in the order of the terminal 80 indicated by reference sign c2, the terminal 60 indicated by reference sign d2, the terminal 60 indicated by reference sign a2, and the terminal 80 indicated by reference sign b2, and the result of the simulation of the leakage magnetic flux is shown.

[0087] Further, FIG. 7C shows the result of performing a simulation of leakage magnetic flux assuming a case where the mounting surface is reversed by rotating the arrangement of the terminals of the coil device 2 shown in FIG. 7A so as to be reversed about the Y axis. That is, in FIG. 7C, the current is passed through in the order of the terminal 80 indicated by reference sign b2, the terminal 60 indicated by reference sign a2, the terminal 60 indicated by reference sign d2, and the terminal 80 indicated by reference sign c2, and the result of the simulation of the leakage magnetic flux is shown.

[0088] In FIGS. 7A to 7C, B1a, B2a, B3a, and B4a represent the magnetic flux density of the leakage magnetic flux, respectively, and the magnetic flux density is highest for B1a and gradually decreases for B2a, B3a, and B4a.

[0089] Comparative Example 1 A computer simulation was performed for each leakage magnetic flux when the direction of passing current was changed for a conventional coil device 3 in which all lead portions were connected to a connection portion arranged on the upper surface of the flange portion. That is, in the conventional coil device 3, the winding direction of the coil was a winding method in which the start of winding of the wire wound around each winding core portion started from the outside and ended inside, or a winding method in which the start of winding started from the inside and ended outside.

[0090] FIG. 8A shows the result of performing a leakage magnetic flux simulation on the coil device 3 by flowing current in the order of the terminal 60a indicated by the symbol a3, the terminal 80a indicated by the symbol b3, the terminal 80a indicated by the symbol c3, and the terminal 60a indicated by the symbol d3. Further, FIG. 8B shows the result of performing a leakage magnetic flux simulation assuming a case where the arrangement of the terminals of the coil device 3 shown in FIG. 8A is rotated so as to be reversed about the Z axis and the mounting direction is reversed. That is, in FIG. 8B, current is flowed in the order of the terminal 80a indicated by the symbol C3, the terminal 60a indicated by the symbol d3, the terminal 60a indicated by the symbol a3, and the terminal 80 indicated by the symbol b3, and it is the result of performing a leakage magnetic flux simulation.

[0091] In FIGS. 8A and 8B, B1b, B2b, B3b, and B4b respectively represent the magnetic flux density of the leakage magnetic flux, and the magnetic flux density is highest for B1b and gradually decreases for B2b, B3b, and B4b.

[0092] Evaluation Compared with the change in the leakage magnetic flux shown in Comparative Example 1 shown in FIGS. 8A and 8B, in Example 1 shown in FIGS. 6A and 6B and Example 2 shown in FIGS. 7A and 7B, it was confirmed that even when the mounting direction was reversed, the change in the leakage magnetic flux was small. That is, it was possible to predict that in Examples 1 and 2, the change in the operating characteristics due to the difference in the mounting direction was small compared with Comparative Example 1. In addition, in Example 2, it was confirmed that the region where the leakage magnetic flux increases could also be minimized compared with Example 1. Further, in Example 1, it was confirmed that FIGS. 6A and 6B had almost the same leakage magnetic flux pattern, and even when the mounting direction was reversed, the change in the leakage magnetic flux was smaller.

[0093] In Example 1 shown in FIGS. 6A and 6C and Example 2 shown in FIGS. 7A and 7C, it was confirmed that even when the mounting surface was reversed, the change in the leakage magnetic flux was small. That is, in Example 1 and Example 2, it was possible to predict that, unlike Comparative Example 1, there would be no problem even if the mounting surface was reversed.

Description of Reference Numerals

[0094] 1, 2, 3… Coil device 5… Solder 10… Core 12, 14… Bobbin part 12a, 14a… Outer region 12b, 14b… Inner region 16a… First flange part 16b… Second flange part 20… Upper surface 22… Mounting side lower surface 24… Outer end face 24a… Central outer end face 25… Inner end face 26… First side face 28… Second side face 30, 32… Lateral outer end face 34, 36… Locking receiving part 38… Groove part 50… Cover 51… Lid part 52, 53… Leg part 54, 55… Locking claw 56… Partition part 58… Convex block part 60, 80… Terminal electrode 60a, 80a… Outer surface 60b, 80b… Inner surface 62, 82… Terminal main piece (terminal main part) 68, 88… Base piece 70, 90… Connecting wire part 76, 96… Protruding piece 78, 98… Dummy connecting wire part 100, 110… Wire 101a, 111a… First lead part 101b, 111b… Second lead part 102a, 112a… First winding start / end point 102b, 112b… Second winding start / end point

Claims

1. An annular core having a pair of bobbin portions arranged substantially parallel to the first axis at a predetermined interval along the second axis, a first flange portion connecting one end of each of the bobbin portions, and a second flange portion connecting the other end of each of the bobbin portions, a wire wound along the first axis in contact with each of the bobbin portions, a pair of first terminal electrodes disposed on the first flange portion, a pair of second terminal electrodes disposed on the second flange portion, and a coil device having: the positions of the first winding start and end points of the respective wires located on one side along the first axis belong to either the outer region or the inner region of each bobbin portion as viewed from the first axis direction, the positions of the second winding start and end points of the respective wires located on the other side along the first axis belong to the region on the same side as the region to which the positions of the first winding start and end points belong, each wire has a first lead portion drawn from the first winding start and end points toward the upper surface side of the first flange portion, and a second lead portion drawn from the second winding start and end points toward the lower surface side of the second flange portion, each of the first lead portions is connected to each first connection portion of the pair of first terminal electrodes disposed on the upper surface side of the first flange portion each of the second lead portions is connected to each second connection portion of the pair of second terminal electrodes disposed on the lower surface side of the second flange portion, the first connection portion and the second connection portion to which each wire is connected are located on opposite sides along a third axis that intersects both the first axis and the second axis as viewed from the first axis direction. A coil device.

2. The coil device according to claim 1, wherein the first winding start and end points and the second winding start and end points located in the region on the same side as viewed from the first axis direction are displaced from each other along the circumferential direction of the bobbin portion.

3. A pair of bobbin portions arranged substantially parallel to the first axis at a predetermined interval along the second axis, a core having a first flange portion connecting one end of each of the bobbin portions and a second flange portion connecting the other end of each of the bobbin portions, a wire wound along the first axis in contact with each of the bobbin portions, a pair of first terminal electrodes disposed on the first flange portion, a pair of second terminal electrodes disposed on the second flange portion, and a coil device having: the positions of the first winding start and end points of the respective wires located on one side along the first axis belong to either the outer region or the inner region of each bobbin portion as viewed from the first axis direction, The positions of the start and end points of the second winding of each wire located on the other side along the first axis belong to the area on the same side as the area to which the positions of the start and end points of the first winding belong. Each wire has a first lead portion drawn from the start and end points of the first winding toward the upper surface side of the first flange portion, and a second lead portion drawn from the start and end points of the second winding toward the lower surface side of the second flange portion. Each of the first lead portions is connected to each first connecting portion of the pair of first terminal electrodes disposed on the upper surface side of the first flange portion. Each of the second lead portions is connected to each second connecting portion of the pair of second terminal electrodes disposed on the lower surface side of the second flange portion. The first connecting portion and the second connecting portion to which each wire is connected are located on opposite sides of each other along a third axis that intersects both the first axis and the second axis when viewed from the first axis direction. Each first terminal electrode is provided with a first dummy connecting portion on the side opposite to the first connecting portion along the third axis. A coil device in which each second terminal electrode is provided with a second dummy connecting portion on the side opposite to the second connecting portion along the third axis.

4. The coil device according to claim 3, wherein the first dummy connecting portion and the second connecting portion have a mounting-side protruding piece whose tip is located on a substantially the same plane.

5. The coil device according to claim 4, wherein the second dummy connecting portion and the first connecting portion have a non-mounting-side protruding piece whose tip is located on a substantially the same plane.

6. The first lead portion extends along the first axis. The coil device according to claim 5, wherein the non-mounting-side protruding piece has a pair of bent pieces surrounding from both sides along the second axis.

7. The second lead portion extends along the first axis. The coil device according to any one of claims 4 to 6, wherein the mounting-side protruding piece has a pair of bent pieces surrounding from both sides along the second axis.

8. A pair of bobbin portions arranged substantially parallel to each other along the first axis at a predetermined interval along the second axis. An annular core having a first flange portion connecting one end of each of the bobbin portions and a second flange portion connecting the other end of each of the bobbin portions. Wires wound along the first axis around each of the bobbin portions. A pair of first terminal electrodes disposed on the first flange portion. A pair of second terminal electrodes disposed on the second flange portion, and a coil device having: Each first lead portion of each wire located on the side of the first flange portion along the first axis is connected to the first connecting portion of each first terminal electrode. The second lead portions of the respective wires located on the side of the second flange portion along the first axis of each wire are connected to the second connection portions of the respective second terminal electrodes. A coil device in which the first connection portion and the second connection portion are located on opposite sides when viewed from the first axis direction along a third axis that intersects both the first axis and the second axis.

9. A pair of bobbin portions arranged substantially parallel to each other along the first axis at a predetermined interval along the second axis. A core having a first flange portion connecting one end of each of the bobbin portions and a second flange portion connecting the other end of each of the bobbin portions. Wires wound along the first axis around each of the bobbin portions. A pair of first terminal electrodes disposed on the first flange portion. A coil device having a pair of second terminal electrodes disposed on the second flange portion, The first lead portion of each wire located on the side of the first flange portion along the first axis of each wire is connected to the first connection portion of the first terminal electrode. The second lead portions of the respective wires located on the side of the second flange portion along the first axis of each wire are connected to the second connection portions of the respective second terminal electrodes. Along a third axis that intersects both the first axis and the second axis, the first connection portion and the second connection portion are located on opposite sides when viewed from the first axis direction. Each first terminal electrode is provided with a first dummy connection portion on the side opposite to the first connection portion along the third axis. A coil device in which each second terminal electrode is provided with a second dummy connection portion on the side opposite to the second connection portion along the third axis.

10. The coil device according to claim 9, wherein the first dummy connection portion and the second connection portion have a mounting-side protruding piece whose tip is located on substantially the same plane.

Images