Common mode choke coil

Abstract

The present invention provides a common mode choke coil. In a common mode choke coil wound with two wires twisted together, good mode conversion characteristics can be obtained. In a common mode choke coil (1) including a twisted wire portion (19), the number of times the first wire (4) is closer to the outside than the second wire (5) on the first side surface (10) of the winding core 2 is the same as the number of times the second wire (4) is closer to the outside than the first wire (4) on the second side surface (11) opposite to the first side surface (10), and the number of times the first wire (4) is closer to the outside than the second wire (5) on the top surface (8) of the winding core (2) is the same as the number of times the second wire (5) is closer to the outside than the first wire (4) on the bottom surface (9) opposite to the top surface (8).

Description

[0001] This application is a divisional application of the application with application number 2019 1 0058 211.3, application date January 22, 2019, and invention name “Common Mode Choke Coil” Technical Field

[0002] The present invention relates to a common mode choke coil, and more particularly to a common mode choke coil having a structure in which two wires twisted together are wound around a winding core. Background Art

[0003] The common mode choke coil involved in the present invention is described in, for example, Japanese Patent Publication No. 2014-216525 (Patent Document 1). The common mode choke coil described in Patent Document 1 has a structure in which a twisted wire portion in which a first wire and a second wire are twisted together are wound around a winding core. According to Patent Document 1, it is described that if the first wire and the second wire are formed into a twisted wire portion, the stray capacitance between the first wire and the second wire can be reduced, and the reduction in the coupling coefficient between the coil formed by the first wire and the coil formed by the second wire can be suppressed.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2014-216525

[0005] Patent Document 1 describes that the number of turns of the first thread and the second thread twisted together is two or more (see, for example, claim 3). However, Patent Document 1 does not describe in detail a specific method of twisting the first thread and the second thread.

[0006] In the case of a normal twisted pair cable, the strength of the wire itself is ensured to a certain extent. However, in the case of a wire used for a small coil component, unlike the case of the above-mentioned twisted pair cable, the greater the number of twisted turns, the higher the possibility of wire breakage. Therefore, in practice, the number of twisted turns has to be reduced to about several turns per turn.

[0007] Therefore, there is a possibility that the electrical balance between the first wire and the second wire may deteriorate. To be more specific, for example, there is a case where, in the circumference of the winding core having a quadrilateral cross section, the number of times the first wire is on the outside (or on the bottom) on the top surface is inconsistent with the number of times the second wire is on the outside (or on the bottom) on the bottom surface opposite to the top surface, and the number of times the first wire is on the outside (or on the bottom) on the first side surface is inconsistent with the number of times the second wire is on the outside (or on the bottom) on the second side surface opposite to the first side surface.

[0008] As a result, a difference can be generated between the stray capacitance formed in relation to the first line and the stray capacitance formed in relation to the second line. In this case, the inductance and capacitance that are affected by the signals passing through the first line and the second line respectively disappear equally, which may cause the mode conversion characteristics of the common mode choke coil to deteriorate. Summary of the invention

[0009] Therefore, an object of the present invention is to provide a method of twisting a first wire and a second wire in a common mode choke coil, which can improve the mode conversion characteristics.

[0010] The present invention relates to a common mode choke coil, comprising: a winding core having a shape extending along a central axis and having a circumferential surface formed around the central axis, the circumferential surface including a first surface and a second surface opposite to each other, and a third surface and a fourth surface adjacent to the first surface and the second surface and opposite to each other; a first wire and a second wire, which are wound in the same direction around the circumferential surface, are not electrically connected to each other, and have twisted wire portions that are twisted together.

[0011] In such a common mode choke coil, in order to solve the above-mentioned technical problem, the present invention is characterized in that, in a certain turn including the above-mentioned twisted wire portion, the number of times the first wire is closer to the outside than the second wire on the above-mentioned first surface is the same as the number of times the second wire is closer to the outside than the first wire on the above-mentioned second surface, and the number of times the first wire is closer to the outside than the second wire on the above-mentioned third surface is the same as the number of times the second wire is closer to the outside than the first wire on the above-mentioned fourth surface.

[0012] In this specification, the following positional relationship between the first line and the second line is referred to as “having symmetry”: as described above, in two opposing surfaces, the number of times the first line is outside the second line on one surface is the same as the number of times the second line is outside the first line on the other surface.

[0013] Furthermore, the first surface, the second surface, the third surface, and the fourth surface are determined relatively, and the correspondence relationship with the top surface, the bottom surface, and the two side surfaces constituting the peripheral surface of the winding core can be arbitrarily selected.

[0014] In the present invention, it is preferred that, among the multiple turns including the above-mentioned twisted wire portion, the number of times the first wire is closer to the outside than the second wire on the first surface is the same as the number of times the second wire is closer to the outside than the first wire on the second surface, and the number of times the first wire is closer to the outside than the second wire on the third surface is the same as the number of times the second wire is closer to the outside than the first wire on the fourth surface.

[0015] According to this configuration, the number of turns having symmetry with respect to the positional relationship between the first wire and the second wire increases, and thus the equality of the inductance and capacitance of each of the first wire and the second wire can be further improved.

[0016] Here, the first and second wires are symmetrical and preferably pass through substantially all the turns. In addition, the first and second wires do not just "pass through all the turns", but "substantially pass through all the turns" because, for example, it is difficult to twist the first and second wires as specified at the beginning and end of the winding of the wire.

[0017] In the present invention, the number of twists of the twisted wire portion on the first, second, third and fourth surfaces is preferably 2 or less. According to this structure, the residual stress applied to the wire for twisting can be reduced, thereby improving the mechanical strength and long-term reliability of the wire.

[0018] In the present invention, the cross-sectional shape of the winding core perpendicular to the central axis of the winding core is typically a quadrilateral. However, the following modified examples can also be adopted.

[0019] First, the cross-sectional shape of the first surface perpendicular to the central axis of the winding core can be formed into a curved shape protruding outward.

[0020] Second, the cross-sectional shape of the first surface perpendicular to the central axis of the winding core can be formed into a curved shape protruding outward.

[0021] In addition, in each of the above-mentioned first and second variants, the cross-sectional shape of the second surface along the surface orthogonal to the central axis of the winding core can be a straight line shape, and the first and second surfaces can also be symmetrical with respect to the cross-sectional shape orthogonal to the central axis of the winding core.

[0022] According to the present invention, the inductance and capacitance that are affected by the signals passing through the first line and the second line can be made close to each other. Therefore, it is possible to realize electrical characteristics excellent in mode conversion characteristics in the common mode choke coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view of the common mode choke coil 1 according to the first embodiment of the present invention.

[0024] Figure 2 yes Figure 1 A bottom view of the common mode choke coil 1 is shown.

[0025] Figure 3 It is along Figure 1 The line III-III indicates Figure 1 FIG. 2 is a diagram showing a twisting pattern of a first wire 4 and a second wire 5 wound around a winding core 2 included in a common mode choke coil 1 .

[0026] Figure 4 (A) shows the state where the first thread 4 and the second thread 5 are twisted together. Figure 4 (B) means Figure 1 and Figure 2 A diagram showing a schematic diagram of the first line 4 and the second line 5 used in FIG.

[0027] Figure 5 The circumference of the winding core 2 is schematically shown in a state where the circumference of the winding core 2 is unfolded. Figure 1 FIG. 2 is a diagram showing a twisting method of the first wire 4 and the second wire 5 of the common mode choke coil 1.

[0028] Figure 6 1 and 1 are diagrams showing the twisting pattern of the first wire 4 and the second wire 5 of the common mode choke coil of the comparative example. Figure 5 The corresponding figure.

[0029] Figure 7 It is a cross-sectional view of a winding core 2a included in a common mode choke coil according to a second embodiment of the present invention.

[0030] Figure 8 It is a cross-sectional view of a winding core 2 b included in a common mode choke coil according to a third embodiment of the present invention.

[0031] Fig. 9 It is a cross-sectional view of a winding core 2c included in a common mode choke coil according to a fourth embodiment of the present invention.

[0032] Fig.10 It is a cross-sectional view of a winding core 2d included in a common mode choke coil according to a fifth embodiment of the present invention.

[0033] Description of Reference Numerals

[0034] 1…common mode choke coil; 2, 2a, 2b, 2c, 2d…winding core; 4…first line; 5…second line; 8…top surface; 9…bottom surface; 10…first side surface; 11…second side surface. DETAILED DESCRIPTION

[0035] Reference Figure 1 to Figure 5 , a common mode choke coil 1 according to a first embodiment of the present invention will be described.

[0036] The common mode choke coil 1 includes a cylindrical core 3 having a winding core 2. The common mode choke coil 1 also includes a first wire 4 and a second wire 5 arranged around the winding core 2. Figure 1 to Figure 3 In order to clearly distinguish the first line 4 from the second line 5, the first line 4 is painted black and the second line 5 is hollow, and they are shown separately.

[0037] The cylindrical core 3 is made of a non-conductive material, more specifically, a non-magnetic body such as alumina, a magnetic body such as Ni-Zn ferrite, or a resin. As the resin, there are, for example, a resin containing magnetic powders such as metal powder and ferrite powder, a resin containing non-magnetic powders such as silica powder, and a resin containing no filler such as powder. The wires 4 and 5 are made of, for example, copper wires having a diameter of 0.02 mm or more and 0.080 mm or less, which are covered with an electrically insulating resin such as polyurethane, imide-modified polyurethane, polyimide ester, or polyamide-imide.

[0038] As per Figure 3 As is clear, the winding core 2 has a shape extending along the central axis, and its cross-sectional shape orthogonal to the central axis is a quadrilateral. In more detail, the winding core 2 is formed with a peripheral surface around its central axis, and the peripheral surface includes a top surface 8 and a bottom surface 9 that are opposite to each other, and a first side surface 10 and a second side surface 11 that are adjacent to the top surface 8 and the bottom surface 9 and opposite to each other. That is, the first side surface 10, the second side surface 11, the top surface 8, and the bottom surface 9 constitute an example of the first surface, the second surface, the third surface, and the fourth surface, respectively.

[0039] The cylindrical core 3 has a first flange 12 and a second flange 13 connected to the first end and the second end of the winding core 2, respectively. The first flange 12 is provided with a first terminal electrode 14 and a third terminal electrode 16, and the second flange 13 is provided with a second terminal electrode 15 and a fourth terminal electrode 17. The terminal electrodes 14 to 17 are provided along the surfaces of the flange 12 and the flange 13 that face the same direction as the bottom surface 9 of the winding core 2. The terminal electrodes 14 to 17 are formed, for example, by baking a conductive paste, plating a conductive metal, pasting a conductive metal sheet, etc. When baking a conductive paste is applied to the formation of the terminal electrodes 14 to 17, for example, a conductive paste containing silver and using silver as a conductive component is used and the conductive paste is baked. In addition, as required, after baking the conductive paste, for example, copper, nickel and tin are plated in sequence.

[0040] The ends of the first wire 4 are connected to the first terminal electrode 14 and the second terminal electrode 15, respectively, and the ends of the second wire 5 are connected to the third terminal electrode 16 and the fourth terminal electrode 17. For example, thermocompression bonding or laser welding is used for these connections.

[0041] The common mode choke coil 1 may further include a plate-like core 18. Similar to the cylindrical core 3, the plate-like core 18 is made of, for example, a non-magnetic material such as alumina, a magnetic material such as Ni-Zn ferrite, or a resin. In the case of the plate-like core 18, as the above-mentioned resin, there are resins containing magnetic powders such as metal powder and ferrite powder, resins containing non-magnetic powders such as silica powder, and resins that do not contain fillers such as powders. When the cylindrical core 3 and the plate-like core 18 are made of magnetic materials, the plate-like core 18 is provided so as to connect the first flange 12 and the second flange 13, whereby the cylindrical core 3 and the plate-like core 18 cooperate to form a closed magnetic circuit.

[0042] Most of the first wire 4 and the second wire 5, except for the ends connected to the above-mentioned terminal electrodes 14 to 17 and their vicinities, become twisted wire portions twisted together. Usually, the first wire 4 and the second wire 5 are twisted together while being wound around the winding core 2. The first wire 4 and the second wire 5 including the twisted wire portions are spirally wound in the same direction around the winding core 2 with substantially the same number of turns. As described above, the first wire 4 and the second wire 5 are covered with insulation and are thus not electrically connected to each other.

[0043] Furthermore, the first wire 4 and the second wire 5 may have other portions that are not twisted with each other, except for the ends connected to the above-mentioned terminal electrodes 14 to 17 and the vicinity thereof.

[0044] Figure 4 Used for Figure 1 and Figure 2 The twisted wire portion 19 composed of two wires 4 and 5 is illustrated in a schematic diagram form. Figure 4 In (A), the twisted portion 19 in which the first thread 4 and the second thread 5 are twisted together is enlarged and represented by a front view. Figure 4 In (B), Figure 4 The first line 4 and the second line 5 shown in (A) are schematically shown in an angular form. Figure 4 In (A) and (B), in order to clearly distinguish the first line 4 from the second line 5, the first line 4 is shaded and the second line 5 is illustrated with a hollow shape.

[0045] In addition, Figure 4 In (A) and (B), the twisted portion 19 is shown as a Z-twist, but the twisted portion may be an S-twist with the opposite twisting direction, or the Z-twist and the S-twist may be mixed. Figure 4 In (A) and (B), the first yarn 4 and the second yarn 5 are twisted closely together, but the first yarn 4 and the second yarn 5 may be twisted partially with a gap therebetween.

[0046] exist Figure 4In (A) and (B), the peripheral surface of the winding core 2 is intended to exist on the opposite side of the paper. Figure 4 As shown, in the twisted portion of the first wire 4 and the second wire 5 observed from the direction opposite to the circumferential surface of the winding core 2, the first wire 4 and the second wire 5 are twisted 360 degrees within the range of the length L. That is, the number of twisting turns of the first wire 4 and the second wire 5 is 1 within the range of the length L. In addition, within the range of the length L, the second wire 5 shown in hollow is located above the first wire 4 shown in shaded.

[0047] The winding core 2 is shown in cross section. Figure 3 In, also with Figure 4 The first line 4 and the second line 5 are schematically shown in an angular form in the same manner as in (B). Figure 3 As is clear, the first wire 4 and the second wire 5 are arranged side by side in the horizontal direction on four ridges formed between the first side surface 10, the top surface 8, the second side surface 11, and the bottom surface 9 of the winding core 2. This stabilizes the winding state of the first wire 4 and the second wire 5 on the winding core 2, thereby contributing to stabilization of the electrical characteristics of the common mode choke coil 1.

[0048] In addition, Figure 5 , the twisting method of the first wire 4 and the second wire 5 is schematically shown in a state where the peripheral surface of the winding core 2 is unfolded in the order of the first side surface 10, the top surface 8, the second side surface 11, and the bottom surface 9. Figure 5 , the first line 4 is indicated by a thick line, and the second line 5 is indicated by a double line. In addition, in the intersection portion between the first line 4 and the second line 5, the line located on the upper side is indicated by a solid line, and the line located on the lower side is indicated by a dotted line.

[0049] Reference Figure 5 On the first side surface 10, the first thread 4 and the second thread 5 are twisted 360 degrees, and the number of twisting turns is 1 which is a multiple of 0.5. In addition, the first thread 4 is closer to the outside than the second thread 5 once, and the second thread 5 is closer to the outside than the first thread 4 once.

[0050] Next, on the top surface 8, the first thread 4 and the second thread 5 are twisted 540 degrees, and the number of twist turns is 1.5 which is a multiple of 0.5. In addition, the first thread 4 is outside the second thread 5 twice, and the second thread 5 is outside the first thread 4 once.

[0051] Next, on the second side surface 11, the first thread 4 and the second thread 5 are twisted 360 degrees, and the number of twist turns is 1, which is a multiple of 0.5. In addition, the first thread 4 is closer to the outside than the second thread 5 once, and the second thread 5 is closer to the outside than the first thread 4 once.

[0052] Next, on the bottom surface 9, the first thread 4 and the second thread 5 are twisted 540 degrees, and the number of twist turns is 1.5 which is a multiple of 0.5. In addition, the first thread 4 is outside the second thread 5 once, and the second thread 5 is outside the first thread 4 twice.

[0053] Based on this, the following characteristics can be found.

[0054] Regarding the first side surface 10 and the second side surface 11 facing each other, the number of times the first line 4 is located outside the second line 5 on the first side surface 10 is the same as the number of times the second line 5 is located outside the first line 4 on the second side surface 11 , which is 1.

[0055] From a different point of view, the number of times the first line 4 is located outside the second line 5 on the second side surface 11 is the same as the number of times the second line 5 is located outside the first line 4 on the first side surface 10 , which is one time.

[0056] On the other hand, regarding the top surface 8 and the bottom surface 9 facing each other, the number of times the first line 4 is located outside the second line 5 on the top surface 8 is the same as the number of times the second line 5 is located outside the first line 4 on the bottom surface 9, which is 2 times.

[0057] From a different point of view, the number of times the first line 4 is located outside the second line 5 on the bottom surface 9 is the same as the number of times the second line 5 is located outside the first line 4 on the top surface 8 , which is one time.

[0058] In addition, if the top surface 8 and the bottom surface 9 are considered, the number of times the first line 4 is closer to the outside than the second line 5 and the number of times the second line 5 is closer to the outside than the first line 4 are both 3 times in total. Similarly, if the first side surface 10 and the second side surface 11 are considered, the number of times the first line 4 is closer to the outside than the second line 5 and the number of times the second line 5 is closer to the outside than the first line 4 are both 2 times in total.

[0059] Furthermore, when winding the wires 4 and 5 around the circumference of the winding core 2 while realizing such a twisting method, it is preferable to use a winding device that can change the number of twisting turns per unit length for each of the first side surface 10, the top surface 8, the second side surface 11, and the bottom surface 9. More specifically, the winding device can change the twisting speed and the winding speed for each of the first side surface 10, the top surface 8, the second side surface 11, and the bottom surface 9.

[0060] As described above, if the positional relationship between the first wire 4 and the second wire 5 on one surface and the positional relationship between the first wire 4 and the second wire 5 on the other surface are symmetrical between two surfaces facing each other, the inductance and capacitance that are affected by the signals passing through the first wire 4 and the second wire 5 can be made equal to each other. Therefore, in the common mode choke coil 1, electrical characteristics with excellent mode conversion characteristics can be realized.

[0061] In addition, in a certain turn of the twisted portion including the first wire 4 and the second wire 5 twisted together, as described above, if the first wire 4 and the second wire 5 are symmetrical, it is an embodiment within the scope of the present invention. However, the more the number of turns in which the twisted first wire 4 and the second wire 5 are symmetrical increases, the more the equality of the inductance and capacitance of each of the first wire 4 and the second wire 5 can be improved. Therefore, it is more preferred that the first wire 4 and the second wire 5 are symmetrical in a plurality of turns including the twisted portion as described above, and it is further preferred that the first wire 4 and the second wire 5 are symmetrical in substantially all turns including the twisted portion as described above.

[0062] Figure 6 is with Figure 5 The corresponding figure shows the twisting method of the first wire 4 and the second wire 5 in the common mode choke coil of the comparative example. Figure 6 In, equivalent to Figure 5 The same reference numerals are used for the components shown, and duplicate descriptions are omitted. In this comparative example, the twisted first yarn 4 and the second yarn 5 do not have symmetry.

[0063] That is, regarding the first side surface 10 and the second side surface 11 facing each other, the number of times the first line 4 is located outside the second line 5 on the first side surface 10 is 1, but the number of times the second line 5 is located outside the first line 4 on the second side surface 11 is 0.

[0064] On the other hand, regarding the top surface 8 and the bottom surface 9 facing each other, the first line 4 is located outside the second line 5 once on the top surface 8, but the second line 5 is located outside the first line 4 twice on the bottom surface 9.

[0065] Furthermore, if the top surface 8 and the bottom surface 9 are considered, the number of times the first line 4 is closer to the outside than the second line 5 is 2 times, but the number of times the second line 5 is closer to the outside than the first line 4 is 4 times. On the other hand, if the first side surface 10 and the second side surface 11 are considered, the number of times the first line 4 is closer to the outside than the second line 5 is 2 times, but the number of times the second line 5 is closer to the outside than the first line 4 is 0 times.

[0066] Thus, if the number of times one of the first wire 4 and the second wire 5 is closer to the outside than the other between the mutually opposing surfaces is different, a difference will occur in the stray capacitance generated in each of the first wire 4 and the second wire 5. As a result, the inductance and capacitance that are affected by the signals passing through the first wire 4 and the second wire 5 are different, and therefore, the mode conversion characteristics of the common mode choke coil are deteriorated.

[0067] In the first embodiment described above, the cross-sectional shape of the winding core 2 perpendicular to the central axis of the winding core 2 is a quadrilateral whose sides extend in straight lines. However, the following cross-sectional shape may also be adopted. Figure 7 to Figure 10 The modified example shown. Figure 7 to Figure 10 In, equivalent to Figure 3 The same reference numerals are used to designate the components shown, and duplicate descriptions are omitted.

[0068] exist Figure 7 In the winding core 2a shown, the cross-sectional shape of the top surface 8 perpendicular to the central axis of the winding core 2a forms a curved shape protruding outward. The top surface 8 of the winding core 2a is not parallel to the linear bottom surface 9, but faces the bottom surface 9.

[0069] exist Figure 8 In the winding core 2b shown, the cross-sectional shape of the top surface 8 orthogonal to the central axis of the winding core 2b forms a curved shape protruding outward. Therefore, the cross-sectional shape of the winding core 2b is a pentagon. The top surface 8 of the winding core 2b is curved so as not to be parallel to the bottom surface 9 of the straight line shape, but to be opposite to the bottom surface 9.

[0070] exist Fig. 9 In the winding core 2c shown, not only the cross-sectional shape of the top surface 8 orthogonal to the central axis of the winding core 2c forms a curved shape protruding outward, but also the cross-sectional shape of the bottom surface 9 orthogonal to the central axis of the winding core 2c forms a curved shape protruding outward. Therefore, when observed in the cross-sectional shape orthogonal to the central axis, the top surface 8 and the bottom surface 9 are symmetrical. In addition, the top surface 8 of the winding core 2c is not parallel to the bottom surface 9, but is opposite to the bottom surface 9.

[0071] In addition, it can also be, as Fig. 9 In the modified example of the winding core 2 c shown, the curvature of the top surface 8 and the curvature of the bottom surface 9 are different.

[0072] exist Fig.10 In the winding core 2d shown, not only the cross-sectional shape of the top surface 8 perpendicular to the central axis of the winding core 2d forms a curved shape protruding outward, but also the cross-sectional shape of the bottom surface 9 perpendicular to the central axis of the winding core 2d forms a curved shape protruding outward. Therefore, the cross-sectional shape of the winding core 2d is hexagonal. Therefore, when observing the cross-sectional shape perpendicular to the central axis, the top surface 8 and the bottom surface 9 are symmetrical. In addition, the top surface 8 of the winding core 2d is not parallel to the bottom surface 9, but is opposite to the bottom surface 9.

[0073] In addition, it can also be, as Fig.10 In the modified example of the winding core 2 d shown, the curvature of the top surface 8 is different from the curvature of the bottom surface 9 .

[0074] exist Figure 7 to Figure 10In the figure, the winding cores 2a to 2d are shown without arc chamfering at the corners where the sides intersect, but they may also be Figure 3 The same is true for the winding core 2 shown, where the corners where the sides intersect are chamfered.

[0075] As mentioned above Figure 7 to Figure 10 As shown in the embodiment, if the peripheral surface of the winding core 2a to 2d is given a curved shape or a bent shape, the cross-sectional shape presented at the position of the ridgeline of the peripheral surface is a corner portion, and the sharpness of the corner is reduced. This reduces the stress applied to the wire, thereby suppressing the occurrence of damage such as cracks in the wire, and helps to improve the reliability of the common mode choke coil.

[0076] In addition, if Figure 7 and Figure 8 As in the illustrated embodiment, if the top surface 8 and the bottom surface 9 are formed asymmetrically, the resistance to deflection caused by the stress transmitted from the bottom surface 9 can be improved.

[0077] In addition, in reference Figure 7 to Figure 10 In the described embodiment, a curved shape protruding outward or a bent shape protruding outward is given to the top surface 8, or to the top surface 8 and the bottom surface 9, but it may also be possible that, on this basis, a curved shape protruding outward or a bent shape protruding outward is given to the side surfaces 10 and 11.

[0078] As mentioned above, although this invention was demonstrated regarding the embodiment shown in figure, other various modification examples are possible within the scope of this invention.

[0079] For example, in Figure 1 to Figure 3 In the embodiment, although the twisted wire portion of the first wire 4 and the second wire 5 is wound in one layer on the winding core 2, it is also possible to wind in two or more layers. When winding in two or more layers, it is preferred that the first wire 4 and the second wire 5 twisted together have symmetry in each layer.

[0080] However, when two or more layers are wound, it is sufficient that the twisted first wire 4 and the second wire 5 have symmetry in any of the layers. For example, when the outermost layer has symmetry, the influence of the common mode choke coil 1 from the surroundings to the mounting substrate, adjacent components, etc. can be made equal in the first wire 4 and the second wire 5. On the other hand, when the inner layer has symmetry, the influence of the first wire 4 and the second wire 5 in the adjacent relatively inner layer or relatively outer layer can be made equal in the first wire 4 and the second wire 5.

[0081] In addition, the above-mentioned embodiments are merely examples, and it is needless to say that parts of the structures can be replaced or combined between different embodiments.

Claims

1. A common mode choke coil comprising: A winding core having a shape extending along a central axis and having a peripheral surface formed around the central axis, the peripheral surface including a first surface and a second surface facing each other, and a third surface and a fourth surface adjacent to the first surface and the second surface and facing each other; The first wire and the second wire are wound around the circumference in the same direction, are not electrically connected to each other, and have twisted wire portions that are twisted together. In a certain turn including the twisted portion, the number of times the first thread is located outside the second thread on the first surface is the same as the number of times the second thread is located outside the first thread on the second surface, and the number of times the first thread is located outside the second thread on the third surface is the same as the number of times the second thread is located outside the first thread on the fourth surface, The number of times the first line is located on the outer side on the first surface is different from the number of times the first line is located on the outer side on the second surface.

2. The common mode choke coil according to claim 1, wherein In the multiple turns including the twisted wire portion, the number of times the first wire is closer to the outside than the second wire on the first surface is the same as the number of times the second wire is closer to the outside than the first wire on the second surface, and the number of times the first wire is closer to the outside than the second wire on the third surface is the same as the number of times the second wire is closer to the outside than the first wire on the fourth surface.

3. The common mode choke coil according to claim 1, wherein The number of twist turns of the twisted yarn portion on the first surface, the second surface, the third surface, and the fourth surface is 2 or less, respectively.

4. The common mode choke coil according to any one of claims 1 to 3, wherein The winding core has a quadrilateral cross-sectional shape perpendicular to the central axis.

5. The common mode choke coil according to claim 1, wherein The cross-sectional shape of the second surface perpendicular to the central axis is a linear shape.

6. The common mode choke coil according to claim 1, wherein The first surface and the second surface are symmetrical with respect to a cross-sectional shape perpendicular to the central axis.

7. A common mode choke coil comprising: A winding core having a shape extending along a central axis and having a peripheral surface formed around the central axis, the peripheral surface including a first surface and a second surface facing each other, and a third surface and a fourth surface adjacent to the first surface and the second surface and facing each other; The first wire and the second wire are wound around the circumference in the same direction, are not electrically connected to each other, and have twisted wire portions that are twisted together. In a certain turn including the twisted portion, the number of times the first thread is located outside the second thread on the first surface is the same as the number of times the second thread is located outside the first thread on the second surface, and the number of times the first thread is located outside the second thread on the third surface is the same as the number of times the second thread is located outside the first thread on the fourth surface, The cross-sectional shape of the first surface perpendicular to the central axis is a curved shape or a bent shape protruding outward.

8. The common mode choke coil according to claim 7, wherein In the multiple turns including the twisted wire portion, the number of times the first wire is closer to the outside than the second wire on the first surface is the same as the number of times the second wire is closer to the outside than the first wire on the second surface, and the number of times the first wire is closer to the outside than the second wire on the third surface is the same as the number of times the second wire is closer to the outside than the first wire on the fourth surface.

9. The common mode choke coil according to claim 7, wherein The number of twist turns of the twisted yarn portion on the first surface, the second surface, the third surface, and the fourth surface is 2 or less, respectively.

10. The common mode choke coil according to claim 7, wherein The cross-sectional shape of the second surface perpendicular to the central axis is a linear shape.

11. The common mode choke coil according to claim 7, wherein The first surface and the second surface are symmetrical with respect to a cross-sectional shape perpendicular to the central axis.

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