Common mode choke coil

Abstract

The common mode choke coil includes a base body, first to second coils, etc. The first coil includes first to third coil conductors arranged on the surfaces of first to third insulating layers, the first to third coil conductors are electrically connected and stacked on the first to third insulating layers in the height direction, the second coil includes fourth to sixth coil conductors arranged on the surfaces of fourth to sixth insulating layers, the fourth to sixth coil conductors are electrically connected and stacked on the fourth to sixth insulating layers in the height direction, the second coil conductor and the third coil conductor are electrically connected via a first outer via hole conductor arranged at a position overlapping with the outer peripheral side ends of the second and third coil conductors when viewed from the height direction, and a first dummy conductor is provided on the surface of at least one insulating layer of the first, fourth, fifth and sixth insulating layers other than between the second insulating layer and the third insulating layer, overlapping with the first outer via hole conductor when viewed from the height direction and electrically insulated from all the coil conductors.

Description

Technical Field

[0001] The present invention relates to a common mode choke coil. Background Art

[0002] As a type of noise filter for circuits, a common mode choke coil is known. For example, in Patent Document 1, a common mode choke coil is disclosed, including a laminate formed by stacking a plurality of insulating layers, a first coil and a second coil provided inside the laminate, and a first external electrode, a second external electrode, a third external electrode, and a fourth external electrode provided on the outer surface of the laminate, the first external electrode and the second external electrode being electrically connected to one end and the other end of the first coil, respectively, the third external electrode and the fourth external electrode being electrically connected to one end and the other end of the second coil, respectively, the first coil including at least a first spiral conductor, a second spiral conductor, and a third spiral conductor connected to each other via a via conductor in the stacking direction of the laminate, the second coil including at least a fourth spiral conductor, a fifth spiral conductor, and a sixth spiral conductor connected to each other via a via conductor in the stacking direction of the laminate, the first spiral conductor being adjacent to the second spiral conductor and the fourth spiral conductor in the stacking direction, and the fourth spiral conductor being adjacent to the first spiral conductor and the fifth spiral conductor, and the distance between the first spiral conductor and the fourth spiral conductor among the distances between the adjacent spiral conductors in the stacking direction being smaller than the other distances.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-140170

[0004] In the common mode choke coil described in Patent Document 1, Figure 2 , Figure 3 , Figure 7 As described in, for example, the outer peripheral ends of any two of the first spiral conductor, the second spiral conductor, and the third spiral conductor are electrically connected to each other via the via-hole conductor. However, when manufacturing such a common mode choke coil, even if the outer peripheral ends of the spiral conductors are connected to the via-hole conductors by laminating and crimping a plurality of insulating layers provided with spiral conductors, it is sometimes difficult to apply pressure in the lamination direction to the portion where the outer peripheral ends of the spiral conductors overlap with the via-hole conductors. Therefore, in such a common mode choke coil, the connectivity between the outer peripheral ends of the spiral conductors and the via-hole conductors becomes insufficient, and there is a risk of the coil being disconnected. Summary of the invention

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a common mode choke coil having excellent connectivity between an outer peripheral end portion of a coil conductor and a via-hole conductor.

[0006] The common mode choke coil of the present invention is characterized in that it comprises: a body formed by stacking a plurality of insulating layers in a height direction; a first coil arranged inside the body; a second coil arranged inside the body and electrically insulated from the first coil; a first external electrode arranged on the surface of the body and electrically connected to one end of the first coil; a second external electrode arranged on the surface of the body and electrically connected to the other end of the first coil; a third external electrode arranged on the surface of the body and electrically connected to one end of the second coil; and a fourth external electrode arranged on the surface of the body and electrically connected to the other end of the second coil, wherein the first coil comprises: a first coil conductor arranged on the surface of the first insulating layer, a second coil conductor arranged on the surface of the second insulating layer, and a third coil conductor arranged on the surface of the third insulating layer, wherein the first coil conductor, the second coil conductor and the third coil conductor are stacked in the height direction together with the first insulating layer, the second insulating layer and the third insulating layer, and the first coil conductor, the second coil conductor and the third coil conductor are electrically connected, The second coil includes: a fourth coil conductor provided on the surface of a fourth insulating layer, a fifth coil conductor provided on the surface of a fifth insulating layer, and a sixth coil conductor provided on the surface of a sixth insulating layer, the fourth coil conductor, the fifth coil conductor, and the sixth coil conductor being stacked together with the fourth insulating layer, the fifth insulating layer, and the sixth insulating layer in the height direction, and the fourth coil conductor, the fifth coil conductor, and the sixth coil conductor being electrically connected, the second coil conductor being electrically connected to the third coil conductor via a first outer via-hole conductor, the first outer via-hole conductor being provided at a position overlapping with outer peripheral ends of the second coil conductor and the third coil conductor when viewed from the height direction, and a first dummy conductor being further provided on the surface of at least one of the first insulating layer, the fourth insulating layer, the fifth insulating layer, and the sixth insulating layer being provided at a position other than between the second insulating layer and the third insulating layer, the first dummy conductor overlapping with the first outer via-hole conductor when viewed from the height direction, and the first dummy conductor being electrically insulated from all the coil conductors.

[0007] According to the present invention, it is possible to provide a common mode choke coil having excellent connectivity between the outer peripheral end portion of the coil conductor and the via-hole conductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic perspective view showing an example of the common mode choke coil of the present invention.

[0009] Figure 2 Yes means Figure 1An exploded schematic plan view of an example of the internal structure of the blank shown.

[0010] Figure 3 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment A1 - A2 in FIG.

[0011] Figure 4 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment B1 - B2 in FIG.

[0012] Figure 5 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment C1-C2 in FIG.

[0013] Figure 6 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment D1 - D2 in FIG.

[0014] Figure 7 It means Figure 1 A schematic cross-sectional view of the portion corresponding to the line segment E1 - E2 in FIG.

[0015] Figure 8 It is a schematic perspective view showing another example of the common mode choke coil of the present invention.

[0016] Explanation of reference numerals: 1, 2…common mode choke coil; 10…blank; 10a…first end face; 10b…second end face; 10c…first main face; 10d…second main face; 10e…first side face; 10f…second side face; 11, 14, 15…glass ceramic layer; 11a…first insulating layer; 11b…second insulating layer; 11c…third insulating layer; 11d…fourth insulating layer; 11e…fifth insulating layer; 11f…sixth insulating layer; 11g…seventh insulating layer; 11h…eighth insulating layer; 11i…ninth insulating layer insulation layer; 12, 13…ferrite layer; 21…first external electrode; 22…second external electrode; 23…third external electrode; 24…fourth external electrode; 31…first coil; 32…second coil; 41a…first coil conductor; 41b…second coil conductor; 41c…third coil conductor; 41d…fourth coil conductor; 41e…fifth coil conductor; 41f…sixth coil conductor; 41g…seventh coil conductor; 41h…eighth coil conductor; 51…first lead-out electrode; 52…second lead-out electrode; 53… third lead electrode; 54…fourth lead electrode; 61b, 61c, 61e, 61f, 71a, 71b, 71c, 71d, 71e, 71f, 71g, 71h, 81a, 81b, 81c, 81d, 81e, 81f…pad portion; 101b, 101f, 111a, 111c, 111e, 111h, 121a, 121b, 121c, 121d, 121e, 121f…via conductor; 201a…first outer via conductor; 201b…second outer via-hole conductor; 202a…first inner via-hole conductor; 202b…second inner via-hole conductor; 202c…third inner via-hole conductor; 202d…fourth inner via-hole conductor; 300a…first dummy conductor; 300b…second dummy conductor; 300c…third dummy conductor; 300d…fourth dummy conductor; AR1, AR2, AR3, AR4…area; L…length direction; P…center of insulating layer; Q…straight line; S1, S2…connecting portion; T…height direction; W…width direction. DETAILED DESCRIPTION

[0017] The common mode choke coil of the present invention is described below. In addition, the present invention is not limited to the following structure, and can be appropriately changed without departing from the scope of the present invention. In addition, the scheme obtained by combining multiple preferred structures described below is also the present invention.

[0018] [Common mode choke coil]

[0019] Figure 1 It is a schematic perspective view showing an example of the common mode choke coil of the present invention.

[0020] like Figure 1As shown, the common mode choke coil 1 includes a base body 10, a first external electrode 21, a second external electrode 22, a third external electrode 23, and a fourth external electrode 24. Figure 1 Although not shown, the common mode choke coil 1 further includes a first coil and a second coil provided inside the base body 10 as described later.

[0021] In this manual, if Figure 1 As shown in FIG. 1 , the length direction, the height direction, and the width direction are respectively defined by L, T, and W. Here, the length direction L, the height direction T, and the width direction W are orthogonal to each other.

[0022] The blank 10 is substantially rectangular parallelepiped and has a first end face 10a and a second end face 10b facing each other in the longitudinal direction L, a first main face 10c and a second main face 10d facing each other in the height direction T, and a first side face 10e and a second side face 10f facing each other in the width direction W.

[0023] When the common mode choke coil 1 is mounted on a substrate, the first principal surface 10 c or the second principal surface 10 d of the base body 10 serves as a mounting surface.

[0024] The first end face 10a and the second end face 10b of the blank 10 do not need to be strictly orthogonal to the length direction L. In addition, the first main face 10c and the second main face 10d of the blank 10 do not need to be strictly orthogonal to the height direction T. Furthermore, the first side face 10e and the second side face 10f of the blank 10 do not need to be strictly orthogonal to the width direction W.

[0025] It is preferred that the corners and ridges of the blank 10 are rounded. The corners of the blank 10 are the portions where three surfaces of the blank 10 intersect. The ridges of the blank 10 are the portions where two surfaces of the blank 10 intersect.

[0026] The green body 10 is formed by stacking a plurality of insulating layers in the height direction T. More specifically, the green body 10 has a ferrite layer 12, a glass ceramic layer 11, and a ferrite layer 13 in order from the first main surface 10c toward the second main surface 10d. That is, the green body 10 has a structure in which the glass ceramic layer 11 is sandwiched by the ferrite layer 12 and the ferrite layer 13 in the height direction T.

[0027] The glass ceramic layer 11 has a multilayer structure in which a plurality of insulating layers are stacked as will be described later.

[0028] It is preferable that the glass ceramic material constituting the glass ceramic layer 11 includes a glass material containing at least K, B, and Si.

[0029] The glass material preferably contains: 0.5 weight % or more and 5 weight % or less of K calculated as K2O, 10 weight % or more and 25 weight % or less of B calculated as B2O3, 70 weight % or more and 85 weight % or less of Si calculated as SiO2, and 0 weight % or more and 5 weight % or less of Al calculated as Al2O3.

[0030] The glass ceramic material preferably contains SiO2 (quartz) and Al2O3 (alumina) as fillers in addition to the above-mentioned glass material. In this case, the glass ceramic material preferably contains 60% by weight or more and 66% by weight or less of the glass material, 34% by weight or more and 37% by weight or less of SiO2 as a filler, and 0.5% by weight or more and 4% by weight or less of Al2O3 as a filler. By including SiO2 as a filler in the glass ceramic material, the high-frequency characteristics of the common mode choke coil 1 are improved. In addition, by including Al2O3 as a filler in the glass ceramic material, the mechanical strength of the blank 10 is improved.

[0031] The ferrite layer 12 and the ferrite layer 13 may each have a single-layer structure or a multi-layer structure.

[0032] Ferrite materials constituting the ferrite layer 12 and the ferrite layer 13 are preferably Ni-Cu-Zn ferrite materials. When the ferrite layer 12 and the ferrite layer 13 are made of Ni-Cu-Zn ferrite materials, the inductance of the common mode choke coil 1 is improved.

[0033] The Ni-Cu-Zn ferrite material preferably contains 40 mol% to 49.5 mol% Fe2O3, 5 mol% to 35 mol% ZnO, 6 mol% to 12 mol% CuO, and 8 mol% to 40 mol% NiO. These oxides may contain inevitable impurities.

[0034] Ni-Cu-Zn based ferrite materials may also contain additives such as Mn3O4, Co3O4, SnO2, Bi2O3, and SiO2.

[0035] The first external electrode 21 is provided on the surface of the body 10. More specifically, the first external electrode 21 extends over a portion of each of the first principal surface 10c, the first side surface 10e, and the second principal surface 10d of the body 10.

[0036] The second external electrode 22 is provided on the surface of the body 10. More specifically, the second external electrode 22 extends over a portion of each of the first main surface 10c, the second side surface 10f, and the second main surface 10d of the body 10. In addition, the second external electrode 22 is provided at a position opposite to the first external electrode 21 in the width direction W.

[0037] The third external electrode 23 is provided on the surface of the body 10. More specifically, the third external electrode 23 extends over a portion of the first main surface 10c, the first side surface 10e, and the second main surface 10d of the body 10 at a position separated from the first external electrode 21 in the longitudinal direction L.

[0038] The fourth external electrode 24 is provided on the surface of the body 10. More specifically, the fourth external electrode 24 extends over a portion of each of the first main surface 10c, the second side surface 10f, and the second main surface 10d of the body 10 at a position separated from the second external electrode 22 in the length direction L. In addition, the fourth external electrode 24 is provided at a position opposite to the third external electrode 23 in the width direction W.

[0039] Each of the first external electrode 21 , the second external electrode 22 , the third external electrode 23 , and the fourth external electrode 24 may have a single-layer structure or a multi-layer structure.

[0040] When the first external electrode 21, the second external electrode 22, the third external electrode 23 and the fourth external electrode 24 are respectively single-layer structures, the constituent materials of each external electrode include, for example, Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0041] When the first external electrode 21, the second external electrode 22, the third external electrode 23 and the fourth external electrode 24 are respectively multilayer structures, each external electrode may also have, from the surface side of the blank 10, for example, a base electrode layer containing Ag, a Ni plating layer, and a Sn plating layer in sequence.

[0042] Figure 2 Yes means Figure 1 An exploded schematic plan view of an example of the internal structure of the blank shown. Figure 3 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment A1 - A2 in FIG. Figure 4 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment B1 - B2 in FIG. Figure 5 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment C1-C2 in FIG. Figure 6 It means Figure 1 Schematic cross-sectional view of the portion corresponding to the line segment D1 - D2 in FIG. Figure 7 It means Figure 1 A schematic cross-sectional view of the portion corresponding to the line segment E1 - E2 in FIG.

[0043] like Figure 2 , Figure 3 , Figure 4, Figure 5 , Figure 6 and Figure 7 As shown, the glass ceramic layer 11 constituting the body 10 is formed by stacking a plurality of insulating layers including a first insulating layer 11a, a second insulating layer 11b, a third insulating layer 11c, a fourth insulating layer 11d, a fifth insulating layer 11e, a sixth insulating layer 11f, a seventh insulating layer 11g, and an eighth insulating layer 11h in the height direction T. In the body 10, more specifically, in the glass ceramic layer 11, the seventh insulating layer 11g, the fourth insulating layer 11d, the third insulating layer 11c, the second insulating layer 11b, the fifth insulating layer 11e, the sixth insulating layer 11f, the first insulating layer 11a, and the eighth insulating layer 11h are stacked in sequence in the height direction T. In the body 10, the seventh insulating layer 11g is located on the first main surface 10c side, and the eighth insulating layer 11h is located on the second main surface 10d side.

[0044] It is preferable that the constituent materials of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e, the sixth insulating layer 11f, the seventh insulating layer 11g, and the eighth insulating layer 11h are the same.

[0045] In the glass ceramic layer 11, at least one insulating layer without a conductor portion such as a coil conductor, a lead electrode, a via conductor, or a dummy conductor described later may be laminated on at least one of the first main surface 10c side of the seventh insulating layer 11g and the second main surface 10d side of the eighth insulating layer 11h. For example, in the glass ceramic layer 11, a ninth insulating layer 11i may be laminated on the second main surface 10d side of the eighth insulating layer 11h.

[0046] The ninth insulating layer 11i is preferably formed of the same material as the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e, the sixth insulating layer 11f, the seventh insulating layer 11g and the eighth insulating layer 11h.

[0047] A first coil 31 and a second coil 32 are provided inside the green body 10 , more specifically, inside the glass ceramic layer 11 .

[0048] The first coil 31 includes a first coil conductor 41 a , a second coil conductor 41 b , a third coil conductor 41 c , and a seventh coil conductor 41 g .

[0049] The first coil conductor 41a is provided on the surface of the first insulating layer 11a. The first coil conductor 41a is provided in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the first insulating layer 11a, and the inner peripheral end is located near the center of the first insulating layer 11a. The outer peripheral end of the first coil conductor 41a is connected to the first lead-out electrode 51 led out from the first external electrode 21. The pad portion 71a is located at the inner peripheral end of the first coil conductor 41a.

[0050] In the first insulating layer 11 a , a via-hole conductor 111 a penetrating in the height direction T is provided at a position overlapping with the pad portion 71 a when viewed in the height direction T.

[0051] A pad portion 81a is provided on the surface of the first insulating layer 11a at a position near the center of the first insulating layer 11a and separated from the pad portion 71a when viewed in the height direction T. In addition, a via hole conductor 121a penetrating in the height direction T is provided in the first insulating layer 11a at a position overlapping with the pad portion 81a when viewed in the height direction T.

[0052] The second coil conductor 41b is disposed on the surface of the second insulating layer 11b. The second coil conductor 41b is disposed in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the second insulating layer 11b, and the inner peripheral end is located near the center of the second insulating layer 11b. The pad portion 61b is located at the outer peripheral end of the second coil conductor 41b. The pad portion 71b is located at the inner peripheral end of the second coil conductor 41b.

[0053] In the second insulating layer 11 b , a via-hole conductor 101 b penetrating in the height direction T is provided at a position overlapping with the pad portion 61 b ​​when viewed in the height direction T.

[0054] A pad portion 81b is provided on the surface of the second insulating layer 11b at a position separated from the pad portion 71b and near the center of the second insulating layer 11b when viewed from the height direction T. In addition, a via hole conductor 121b penetrating in the height direction T is provided in the second insulating layer 11b at a position overlapping with the pad portion 81b when viewed from the height direction T.

[0055] The third coil conductor 41c is provided on the surface of the third insulating layer 11c. The third coil conductor 41c is provided in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the third insulating layer 11c, and the inner peripheral end is located near the center of the third insulating layer 11c. The pad portion 61c is located at the outer peripheral end of the third coil conductor 41c. The pad portion 71c is located at the inner peripheral end of the third coil conductor 41c.

[0056] In the third insulating layer 11 c , a via-hole conductor 111 c penetrating in the height direction T is provided at a position overlapping with the pad portion 71 c when viewed in the height direction T.

[0057] A pad portion 81c is provided on the surface of the third insulating layer 11c at a position separated from the pad portion 71c and near the center of the third insulating layer 11c when viewed from the height direction T. In addition, a via hole conductor 121c penetrating in the height direction T is provided in the third insulating layer 11c at a position overlapping with the pad portion 81c when viewed from the height direction T.

[0058] The seventh coil conductor 41g is provided on the surface of the seventh insulating layer 11g. The seventh coil conductor 41g is provided in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the seventh insulating layer 11g, and the inner peripheral end is located near the center of the seventh insulating layer 11g. The outer peripheral end of the seventh coil conductor 41g is connected to the second lead electrode 52 led out from the second external electrode 22. The pad portion 71g is located at the inner peripheral end of the seventh coil conductor 41g.

[0059] The second coil 32 includes a fourth coil conductor 41d, a fifth coil conductor 41e, a sixth coil conductor 41f, and an eighth coil conductor 41h.

[0060] The fourth coil conductor 41d is provided on the surface of the fourth insulating layer 11d. The fourth coil conductor 41d is provided in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the fourth insulating layer 11d, and the inner peripheral end is located near the center of the fourth insulating layer 11d. The outer peripheral end of the fourth coil conductor 41d is connected to the fourth lead-out electrode 54 led out from the fourth external electrode 24. The pad portion 71d is located at the inner peripheral end of the fourth coil conductor 41d.

[0061] A pad portion 81d is provided on the surface of the fourth insulating layer 11d at a position separated from the pad portion 71d and near the center of the fourth insulating layer 11d when viewed from the height direction T. In addition, a via hole conductor 121d penetrating in the height direction T is provided in the fourth insulating layer 11d at a position overlapping with the pad portion 81d when viewed from the height direction T.

[0062] The fifth coil conductor 41e is provided on the surface of the fifth insulating layer 11e. The fifth coil conductor 41e is provided in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the fifth insulating layer 11e, and the inner peripheral end is located near the center of the fifth insulating layer 11e. The pad portion 61e is located at the outer peripheral end of the fifth coil conductor 41e. The pad portion 71e is located at the inner peripheral end of the fifth coil conductor 41e.

[0063] In the fifth insulating layer 11 e , a via-hole conductor 111 e penetrating in the height direction T is provided at a position overlapping with the pad portion 71 e when viewed in the height direction T.

[0064] On the surface of the fifth insulating layer 11e, a pad portion 81e is provided near the center of the fifth insulating layer 11e and at a position separated from the pad portion 71e when viewed from the height direction T. In addition, in the fifth insulating layer 11e, a via-hole conductor 121e penetrating in the height direction T is provided at a position overlapping with the pad portion 81e when viewed from the height direction T.

[0065] The sixth coil conductor 41f is disposed on the surface of the sixth insulating layer 11f. The sixth coil conductor 41f is disposed in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the sixth insulating layer 11f, and the inner peripheral end is located near the center of the sixth insulating layer 11f. The pad portion 61f is located at the outer peripheral end of the sixth coil conductor 41f. The pad portion 71f is located at the inner peripheral end of the sixth coil conductor 41f.

[0066] In the sixth insulating layer 11 f , a via-hole conductor 101 f penetrating in the height direction T is provided at a position overlapping with the pad portion 61 f when viewed in the height direction T.

[0067] A pad portion 81f is provided on the surface of the sixth insulating layer 11f at a position separated from the pad portion 71f and near the center of the sixth insulating layer 11f when viewed from the height direction T. In addition, a via hole conductor 121f penetrating in the height direction T is provided in the sixth insulating layer 11f at a position overlapping with the pad portion 81f when viewed from the height direction T.

[0068] The eighth coil conductor 41h is provided on the surface of the eighth insulating layer 11h. The eighth coil conductor 41h is provided in a spiral shape, and when viewed from the height direction T, the outer peripheral end is located near the outer edge of the eighth insulating layer 11h, and the inner peripheral end is located near the center of the eighth insulating layer 11h. The outer peripheral end of the eighth coil conductor 41h is connected to the third lead-out electrode 53 led out from the third external electrode 23. The pad portion 71h is located at the inner peripheral end of the eighth coil conductor 41h.

[0069] In the eighth insulating layer 11 h , a via-hole conductor 111 h penetrating in the height direction T is provided at a position overlapping with the pad portion 71 h when viewed in the height direction T.

[0070] When viewed from the height direction T, the pad portion 61b, the pad portion 61c, the pad portion 61e, the pad portion 61f, the pad portion 71a, the pad portion 71b, the pad portion 71c, the pad portion 71d, the pad portion 71e, the pad portion 71f, the pad portion 71g, the pad portion 71h, the pad portion 81a, the pad portion 81b, the pad portion 81c, the pad portion 81d, the pad portion 81e and the pad portion 81f may be respectively Figure 2 The circular shape shown may also be a polygonal shape.

[0071] The first coil conductor 41a, the second coil conductor 41b, the third coil conductor 41c, the fourth coil conductor 41d, the fifth coil conductor 41e, the sixth coil conductor 41f, the seventh coil conductor 41g, the eighth coil conductor 41h, the first lead electrode 51, the second lead electrode 52, the third lead electrode 53, the fourth lead electrode 54, the pad portion 61b, the pad portion 61c, the pad portion 61e, the pad portion 61f, the pad portion 71a, the pad portion 71b, the pad portion 71c, the pad portion 71d, the pad portion 71e, the pad portion 71f, the pad portion 71g, the pad portion 71h, and the pad portion 71 The materials constituting portion 81a, pad portion 81b, pad portion 81c, pad portion 81d, pad portion 81e, pad portion 81f, via-hole conductor 101b, via-hole conductor 101f, via-hole conductor 111a, via-hole conductor 111c, via-hole conductor 111e, via-hole conductor 111h, via-hole conductor 121a, via-hole conductor 121b, via-hole conductor 121c, via-hole conductor 121d, via-hole conductor 121e and via-hole conductor 121f include, for example, Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0072] The seventh insulating layer 11g, the fourth insulating layer 11d, the third insulating layer 11c, the second insulating layer 11b, the fifth insulating layer 11e, the sixth insulating layer 11f, the first insulating layer 11a, and the eighth insulating layer 11h are sequentially stacked in the height direction T, so that the first coil conductor 41a, the second coil conductor 41b, the third coil conductor 41c, and the seventh coil conductor 41g are stacked together with the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the seventh insulating layer 11g in the height direction T and are electrically connected. More specifically, it is as follows.

[0073] First, the pad portion 71g of the seventh coil conductor 41g is electrically connected to the pad portion 71c of the third coil conductor 41c via the via hole conductor 121d, the pad portion 81d, and the via hole conductor 111c in sequence. Here, the via hole conductor 121d and the via hole conductor 111c are arranged at a position overlapping with the inner peripheral end of the third coil conductor 41c and the seventh coil conductor 41g when viewed from the height direction T, that is, at a position overlapping with the pad portion 71c and the pad portion 71g when viewed from the height direction T, and constitute the first inner via hole conductor 202a. Therefore, it can also be said that the third coil conductor 41c and the seventh coil conductor 41g are electrically connected via the first inner via hole conductor 202a, more specifically, via the first inner via hole conductor 202a and the pad portion 81d.

[0074] Next, the pad portion 61c of the third coil conductor 41c is electrically connected to the pad portion 61b of the second coil conductor 41b via the via hole conductor 101b. Here, the via hole conductor 101b is provided at a position overlapping with the outer peripheral end portions of the second coil conductor 41b and the third coil conductor 41c when viewed from the height direction T, that is, at a position overlapping with the pad portion 61b and the pad portion 61c when viewed from the height direction T, and constitutes the first outer via hole conductor 201a. Therefore, it can also be said that the second coil conductor 41b and the third coil conductor 41c are electrically connected via the first outer via hole conductor 201a.

[0075] Next, the pad portion 71b of the second coil conductor 41b is electrically connected to the pad portion 71a of the first coil conductor 41a via the via hole conductor 121e, the pad portion 81e, the via hole conductor 121f, the pad portion 81f, and the via hole conductor 111a in sequence. Here, the via hole conductor 121e, the via hole conductor 121f, and the via hole conductor 111a are arranged at a position overlapping with the inner peripheral end of the first coil conductor 41a and the second coil conductor 41b when viewed from the height direction T, that is, at a position overlapping with the pad portion 71a and the pad portion 71b when viewed from the height direction T, and constitute the second inner via hole conductor 202b. Therefore, it can also be said that the first coil conductor 41a and the second coil conductor 41b are electrically connected via the second inner via hole conductor 202b, more specifically, via the second inner via hole conductor 202b, the pad portion 81e, and the pad portion 81f.

[0076] As described above, the first coil conductor 41 a , the second coil conductor 41 b , the third coil conductor 41 c , and the seventh coil conductor 41 g are electrically connected to form the first coil 31 .

[0077] like Figure 2 and Figure 6As shown, one end of the first coil 31 , more specifically, an outer peripheral end of the first coil conductor 41 a is electrically connected to the first external electrode 21 via the first lead-out electrode 51 .

[0078] like Figure 2 and Figure 6 As shown, the other end of the first coil 31 , more specifically, the outer peripheral end of the seventh coil conductor 41 g is electrically connected to the second external electrode 22 via the second lead-out electrode 52 .

[0079] The seventh insulating layer 11g, the fourth insulating layer 11d, the third insulating layer 11c, the second insulating layer 11b, the fifth insulating layer 11e, the sixth insulating layer 11f, the first insulating layer 11a and the eighth insulating layer 11h are sequentially stacked in the height direction T, so that the fourth coil conductor 41d, the fifth coil conductor 41e, the sixth coil conductor 41f and the eighth coil conductor 41h are stacked together with the fourth insulating layer 11d, the fifth insulating layer 11e, the sixth insulating layer 11f and the eighth insulating layer 11h in the height direction T and are electrically connected. More specifically, as described below.

[0080] First, the pad portion 71d of the fourth coil conductor 41d is electrically connected to the pad portion 71e of the fifth coil conductor 41e via the via hole conductor 121c, the pad portion 81c, the via hole conductor 121b, the pad portion 81b, and the via hole conductor 111e in sequence. Here, the via hole conductor 121c, the via hole conductor 121b, and the via hole conductor 111e are arranged at a position overlapping with the inner peripheral end of the fourth coil conductor 41d and the fifth coil conductor 41e when viewed from the height direction T, that is, at a position overlapping with the pad portion 71d and the pad portion 71e when viewed from the height direction T, and constitute the third inner via hole conductor 202c. Therefore, it can also be said that the fourth coil conductor 41d and the fifth coil conductor 41e are electrically connected via the third inner via hole conductor 202c, more specifically, via the third inner via hole conductor 202c, the pad portion 81c, and the pad portion 81b.

[0081] Next, the pad portion 61e of the fifth coil conductor 41e is electrically connected to the pad portion 61f of the sixth coil conductor 41f via the via hole conductor 101f. Here, the via hole conductor 101f is provided at a position overlapping with the outer peripheral end portions of the fifth coil conductor 41e and the sixth coil conductor 41f when viewed from the height direction T, that is, at a position overlapping with the pad portion 61e and the pad portion 61f when viewed from the height direction T, and constitutes the second outer via hole conductor 201b. Therefore, it can also be said that the fifth coil conductor 41e and the sixth coil conductor 41f are electrically connected via the second outer via hole conductor 201b.

[0082] Next, the pad portion 71f of the sixth coil conductor 41f is electrically connected to the pad portion 71h of the eighth coil conductor 41h via the via hole conductor 121a, the pad portion 81a, and the via hole conductor 111h in sequence. Here, the via hole conductor 121a and the via hole conductor 111h are arranged at a position overlapping with the inner peripheral end of the sixth coil conductor 41f and the eighth coil conductor 41h when viewed from the height direction T, that is, at a position overlapping with the pad portion 71f and the pad portion 71h when viewed from the height direction T, and constitute the fourth inner via hole conductor 202d. Therefore, it can also be said that the sixth coil conductor 41f and the eighth coil conductor 41h are electrically connected via the fourth inner via hole conductor 202d, more specifically, via the fourth inner via hole conductor 202d and the pad portion 81a.

[0083] As described above, the fourth coil conductor 41d, the fifth coil conductor 41e, the sixth coil conductor 41f, and the eighth coil conductor 41h are electrically connected to form the second coil 32. The second coil 32 is electrically insulated from the first coil 31.

[0084] like Figure 2 and Figure 7 As shown, one end of the second coil 32 , more specifically, the outer peripheral end of the eighth coil conductor 41 h is electrically connected to the third external electrode 23 via the third lead-out electrode 53 .

[0085] like Figure 2 and Figure 7 As shown, the other end of the second coil 32 , more specifically, the outer peripheral end of the fourth coil conductor 41 d is electrically connected to the fourth external electrode 24 via the fourth lead-out electrode 54 .

[0086] The coil axes of the first coil 31 and the second coil 32 extend in the height direction T, respectively, passing through the center of gravity of the shapes of the coils when viewed in the height direction T.

[0087] When viewed from the height direction T, the outer shapes of the first coil 31 and the second coil 32 may be Figure 2 The shape composed of straight lines and curves shown may be a circle or a polygon.

[0088] In the common mode choke coil 1, the seventh insulating layer 11g, the fourth insulating layer 11d, the third insulating layer 11c, the second insulating layer 11b, the fifth insulating layer 11e, the sixth insulating layer 11f, the first insulating layer 11a and the eighth insulating layer 11h, which are provided with the above-mentioned coil conductor and other conductive parts, are stacked in sequence in the height direction T. However, due to the stacking in such an order, the common mode attenuation Scc21 which is an indicator of the noise removal performance is likely to become large.

[0089] In the common mode choke coil 1, a first dummy conductor 300a is provided on the surface of at least one of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f, which is provided at a position other than between the second insulating layer 11b and the third insulating layer 11c, and which overlaps with the first outer via hole conductor 201a (via hole conductor 101b) when viewed from the height direction T and is electrically insulated from all the coil conductors. Thus, in a state where a plurality of insulating layers provided with conductor portions such as coil conductors are stacked, a connection portion S1 (see FIG. 1 ) where the land portion 61b of the second coil conductor 41b overlaps with the land portion 61c of the first outer via hole conductor 201a and the third coil conductor 41c overlaps. Figure 4 ) The area located in the height direction T becomes denser corresponding to the amount of the first dummy conductor 300a. Therefore, if the obtained laminate is crimped, it is easy to apply pressure in the height direction T to the connection portion S1. As a result, the connection between the pad portion 61b of the second coil conductor 41b and the first outer via hole conductor 201a is excellent, and the connection between the pad portion 61c of the third coil conductor 41c and the first outer via hole conductor 201a is excellent. That is, the disconnection of the first coil 31 is prevented.

[0090] The first dummy conductor 300 a preferably overlaps the entire first outer via-hole conductor 201 a when viewed from the height direction T, but may overlap a portion of the first outer via-hole conductor 201 a .

[0091] Arrangement modes of the first dummy conductor 300 a include the following first mode, second mode, third mode, and fourth mode.

[0092] (First method)

[0093] All of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f are provided at positions other than between the second insulating layer 11b and the third insulating layer 11c, and the first dummy conductor 300a is provided on the surfaces of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f. Figure 2 and Figure 4 As shown, it is a preferred method. In the first method, compared with the second method described later, more first dummy conductors 300a are provided, so when a plurality of insulating layers provided with conductor parts such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection part S1. As a result, the connection between the land part 61b of the second coil conductor 41b and the first outer via hole conductor 201a is better, and the connection between the land part 61c of the third coil conductor 41c and the first outer via hole conductor 201a is better.

[0094] (Second method)

[0095] All of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f are provided at positions other than between the second insulating layer 11b and the third insulating layer 11c, and the first dummy conductor 300a is provided on the surface of a portion of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f. As a second embodiment, for example, the following embodiment is cited: the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f are provided at positions other than between the second insulating layer 11b and the third insulating layer 11c, and the first dummy conductor 300a is provided on the surfaces of the fourth insulating layer 11d and the fifth insulating layer 11e.

[0096] (Third Method)

[0097] Some of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f are provided at positions other than between the second insulating layer 11b and the third insulating layer 11c, and the first dummy conductor 300a is provided on the surface of all of the insulating layers in the above-mentioned part of the insulating layers. As a third embodiment, for example, the following embodiment is cited: Figure 2 In a state where the second insulating layer 11b and the fifth insulating layer 11e are exchanged, that is, in a state where the first insulating layer 11a, the fourth insulating layer 11d, and the sixth insulating layer 11f are provided at positions other than between the second insulating layer 11b and the third insulating layer 11c, the first dummy conductor 300a is provided on the surfaces of the first insulating layer 11a, the fourth insulating layer 11d, and the sixth insulating layer 11f. In this case, the fifth insulating layer 11e is provided at a position between the second insulating layer 11b and the third insulating layer 11c, but a via-hole conductor penetrating in the height direction T and constituting a part of the first outer via-hole conductor 201a is provided in the fifth insulating layer 11e.

[0098] (Fourth Method)

[0099] A portion of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f is provided at a position other than between the second insulating layer 11b and the third insulating layer 11c, and the first dummy conductor 300a is provided on a surface of another portion of the insulating layers. Figure 2In a state where the second insulating layer 11b and the fifth insulating layer 11e are exchanged, that is, the first insulating layer 11a, the fourth insulating layer 11d and the sixth insulating layer 11f are arranged at a position other than between the second insulating layer 11b and the third insulating layer 11c, the first dummy conductor 300a is arranged on the surface of the fourth insulating layer 11d and the sixth insulating layer 11f.

[0100] The first dummy conductor 300a may be provided on the surface of the insulating layer in the region opposite to the third insulating layer 11c with respect to the second insulating layer 11b among the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f. In this case, it is preferable that the first dummy conductor 300a is provided on the surface of the insulating layer adjacent to the second insulating layer 11b, Figure 2 In the figure, the connection portion S1 is formed on the surface of the fifth insulating layer 11e. Thus, when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S1. As a result, the connection between the land portion 61b of the second coil conductor 41b and the first outer via hole conductor 201a is better, and the connection between the land portion 61c of the third coil conductor 41c and the first outer via hole conductor 201a is better.

[0101] The first dummy conductor 300a may be provided on the surface of the insulating layer in the region opposite to the second insulating layer 11b with respect to the third insulating layer 11c among the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f. In this case, it is preferred that the first dummy conductor 300a be provided on the surface of the insulating layer adjacent to the third insulating layer 11c, Figure 2 In the figure, the connection portion S1 is formed on the surface of the fourth insulating layer 11d. Thus, when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S1. As a result, the connection between the land portion 61b of the second coil conductor 41b and the first outer via hole conductor 201a is further improved, and the connection between the land portion 61c of the third coil conductor 41c and the first outer via hole conductor 201a is further improved.

[0102] The first dummy conductor 300a may be provided on the surface of the insulating layer in the region opposite to the third insulating layer 11c relative to the second insulating layer 11b, and on the surface of the insulating layer in the region opposite to the second insulating layer 11b relative to the third insulating layer 11c, among the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f. In this case, it is preferred that the first dummy conductor 300a is provided on the surface of the insulating layer adjacent to the second insulating layer 11b, on the surface of the insulating layer adjacent to the second insulating layer 11b, and on the surface of the insulating layer adjacent to the third insulating layer 11c. Figure 2The surface of the fifth insulating layer 11e and the surface of the insulating layer adjacent to the third insulating layer 11c are provided on the surface of the fifth insulating layer 11e and the surface of the insulating layer adjacent to the third insulating layer 11c. Figure 2 In the figure, the connection portion S1 is formed on the surface of the fourth insulating layer 11d. Thus, when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S1. As a result, the connection between the land portion 61b of the second coil conductor 41b and the first outer via hole conductor 201a is further improved, and the connection between the land portion 61c of the third coil conductor 41c and the first outer via hole conductor 201a is further improved.

[0103] Preferably, when the configuration mode of the first dummy conductor 300a is the first mode, when a straight line Q is defined which passes through the center P of the insulating layer and extends in the long side direction of the insulating layer when viewed from the height direction T, a second dummy conductor 300b is further provided on the surface of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e and the sixth insulating layer 11f. The second dummy conductor 300b is line-symmetrical with the first outer via conductor 201a with respect to the straight line Q and is electrically insulated from all the coil conductors. In this case, it can also be said that the first dummy conductor 300a and the second dummy conductor 300b are line-symmetrical with respect to the straight line Q when viewed from the height direction T. That is, it can also be said that the second dummy conductor 300b is provided in an area AR2 (refer to FIG. 1 ) which is line-symmetrical with the area AR1 where the connection portion S1 and the first dummy conductor 300a are provided. Figure 5 ).

[0104] If the first dummy conductor 300a is provided on the surface of the first insulating layer 11a, the fourth insulating layer 11d, the fifth insulating layer 11e, and the sixth insulating layer 11f as in the first embodiment, then combined with the presence of the first outer via conductor 201a, the length of the green body 10 in the height direction T becomes larger in the region AR1, so the common mode choke coil 1 may be partially deformed. The influence of such deformation in the region AR1 is likely to spread to the vicinity of the region AR1. In contrast, if the second dummy conductor 300b is provided in the region AR2 located near the region AR1, the length of the region AR2 in the height direction T becomes larger and is likely to be consistent with the length in the height direction T of the region AR1. As a result, the influence of the deformation in the region AR1 is mitigated, thereby suppressing the deformation of the common mode choke coil 1.

[0105] exist Figure 2 In FIG. 1 , the center P and the straight line Q are shown in the first insulating layer 11 a , taking the insulating layers as a representative example. However, the center P and the straight line Q exist at the same positions in other insulating layers as well.

[0106] exist Figure 2In the figure, the long side direction of the insulating layer corresponds to the length direction L, and the short side direction of the insulating layer corresponds to the width direction W. When viewed from the height direction T, the long side direction of the insulating layer may also correspond to the width direction W, and the short side direction of the insulating layer may also correspond to the length direction L. In addition, when the insulating layer is square when viewed from the height direction T, the long side direction and the short side direction of the insulating layer are not distinguished.

[0107] The second dummy conductor 300b may also be disposed on the surface of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e and the sixth insulating layer 11f, or may be disposed on the surface of a portion of the insulating layers among the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e and the sixth insulating layer 11f.

[0108] In the common mode choke coil 1, it is preferred that a third dummy conductor 300c is provided on the surface of at least one of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d, which is provided at a position other than between the fifth insulating layer 11e and the sixth insulating layer 11f, and which overlaps with the second outer via-hole conductor 201b (via-hole conductor 101f) when viewed from the height direction T and is electrically insulated from all the coil conductors. Thus, in a state where a plurality of insulating layers provided with conductor portions such as coil conductors are stacked, a connection portion S2 (see FIG. 1 ) where the pad portion 61e of the fifth coil conductor 41e and the pad portion 61f of the second outer via-hole conductor 201b and the sixth coil conductor 41f overlap. Figure 5 ) is located in the height direction T and the area corresponding to the amount of the third dummy conductor 300c becomes denser. Therefore, if the obtained laminate is crimped, it is easy to apply pressure in the height direction T to the connection portion S2. As a result, the pad portion 61e of the fifth coil conductor 41e and the second outer via hole conductor 201b have excellent connectivity, and the pad portion 61f of the sixth coil conductor 41f and the second outer via hole conductor 201b have excellent connectivity. That is, the disconnection of the second coil 32 is prevented.

[0109] The third dummy conductor 300 c preferably overlaps the entire second outer via-hole conductor 201 b when viewed in the height direction T, but may overlap a portion of the second outer via-hole conductor 201 b .

[0110] Arrangement modes of the third dummy conductor 300 c include the following fifth mode, sixth mode, seventh mode, and eighth mode.

[0111] (Fifth Method)

[0112] All of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d are provided at positions other than between the fifth insulating layer 11e and the sixth insulating layer 11f, and the third dummy conductor 300c is provided on the surfaces of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d. Figure 2 and Figure 5 As shown, it is a preferred mode. In the fifth mode, compared with the sixth mode described later, more third dummy conductors 300c are provided, so when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S2. As a result, the connection between the pad portion 61e of the fifth coil conductor 41e and the second outer via hole conductor 201b is better, and the connection between the pad portion 61f of the sixth coil conductor 41f and the second outer via hole conductor 201b is better.

[0113] (Sixth Method)

[0114] All of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d are provided at positions other than between the fifth insulating layer 11e and the sixth insulating layer 11f, and the third dummy conductor 300c is provided on the surface of a portion of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d. As a sixth embodiment, for example, the following embodiment is cited: the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d are provided at positions other than between the fifth insulating layer 11e and the sixth insulating layer 11f, and the third dummy conductor 300c is provided on the surfaces of the first insulating layer 11a and the second insulating layer 11b.

[0115] (Seventh Method)

[0116] A portion of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d is provided at a position other than between the fifth insulating layer 11e and the sixth insulating layer 11f, and the third dummy conductor 300c is provided on the surface of all of the insulating layers in the portion of the insulating layers. Figure 2In the state where the second insulating layer 11b and the fifth insulating layer 11e are exchanged, that is, the first insulating layer 11a, the third insulating layer 11c, and the fourth insulating layer 11d are provided at positions other than between the fifth insulating layer 11e and the sixth insulating layer 11f, the third dummy conductor 300c is provided on the surfaces of the first insulating layer 11a, the third insulating layer 11c, and the fourth insulating layer 11d. In this case, the second insulating layer 11b is provided at a position between the fifth insulating layer 11e and the sixth insulating layer 11f, but a via-hole conductor penetrating in the height direction T and constituting a part of the second outer via-hole conductor 201b is provided in the second insulating layer 11b.

[0117] (Eighth Method)

[0118] A portion of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d is provided at a position other than between the fifth insulating layer 11e and the sixth insulating layer 11f, and the third dummy conductor 300c is provided on a surface of another portion of the insulating layers. Figure 2 In a state where the second insulating layer 11b and the fifth insulating layer 11e are exchanged, that is, the first insulating layer 11a, the third insulating layer 11c and the fourth insulating layer 11d are arranged at a position other than between the fifth insulating layer 11e and the sixth insulating layer 11f, the third dummy conductor 300c is arranged on the surface of the first insulating layer 11a and the third insulating layer 11c.

[0119] The third dummy conductor 300c may be provided on the surface of the insulating layer in the region opposite to the sixth insulating layer 11f with respect to the fifth insulating layer 11e among the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d. In this case, it is preferred that the third dummy conductor 300c is provided on the surface of the insulating layer adjacent to the fifth insulating layer 11e, Figure 2 In the example, the connection portion S2 is formed on the surface of the second insulating layer 11b. Thus, when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S2. As a result, the connection between the pad portion 61e of the fifth coil conductor 41e and the second outer via hole conductor 201b is further improved, and the connection between the pad portion 61f of the sixth coil conductor 41f and the second outer via hole conductor 201b is further improved.

[0120] The third dummy conductor 300c may be provided on the surface of the insulating layer in the region opposite to the fifth insulating layer 11e with respect to the sixth insulating layer 11f among the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c and the fourth insulating layer 11d. In this case, it is preferred that the third dummy conductor 300c is provided on the surface of the insulating layer adjacent to the sixth insulating layer 11f, Figure 2 In the figure, the first insulating layer 11a is on the surface of the first insulating layer 11a. Thus, when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S2. As a result, the connection between the pad portion 61e of the fifth coil conductor 41e and the second outer via hole conductor 201b is better, and the connection between the pad portion 61f of the sixth coil conductor 41f and the second outer via hole conductor 201b is better.

[0121] The third dummy conductor 300c may be provided on the surface of the insulating layer in the region opposite to the sixth insulating layer 11f with respect to the fifth insulating layer 11e, and on the surface of the insulating layer in the region opposite to the fifth insulating layer 11e with respect to the sixth insulating layer 11f, among the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, and the fourth insulating layer 11d. In this case, it is preferred that the third dummy conductor 300c is provided on the surface of the insulating layer adjacent to the fifth insulating layer 11e, on the surface of the insulating layer adjacent to the fifth insulating layer 11e, and on the surface of the insulating layer adjacent to the sixth insulating layer 11f. Figure 2 The surface of the second insulating layer 11b and the surface of the insulating layer adjacent to the sixth insulating layer 11f are provided on the surface of the second insulating layer 11b and the surface of the insulating layer adjacent to the sixth insulating layer 11f. Figure 2 In the figure, the first insulating layer 11a is on the surface of the first insulating layer 11a. Thus, when a plurality of insulating layers provided with conductor portions such as coil conductors are stacked and crimped, it is easier to apply pressure in the height direction T to the connection portion S2. As a result, the connection between the pad portion 61e of the fifth coil conductor 41e and the second outer via hole conductor 201b is better, and the connection between the pad portion 61f of the sixth coil conductor 41f and the second outer via hole conductor 201b is better.

[0122] Preferably, when the configuration mode of the third dummy conductor 300c is the fifth mode, when a straight line Q is defined that passes through the center P of the insulating layer and extends in the long side direction of the insulating layer when viewed from the height direction T, a fourth dummy conductor 300d is further provided on the surface of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e and the sixth insulating layer 11f. The fourth dummy conductor 300d is line-symmetrical with the second outer via conductor 201b with respect to the straight line Q and is electrically insulated from all the coil conductors. In this case, it can also be said that the third dummy conductor 300c and the fourth dummy conductor 300d are line-symmetrical with respect to the straight line Q when viewed from the height direction T. That is, it can also be said that the fourth dummy conductor 300d is provided in an area AR4 (refer to FIG. 1 ) that is line-symmetrical with the area AR3 where the connection portion S2 and the third dummy conductor 300c are provided. Figure 4 ).

[0123] If the third dummy conductor 300c is provided on the surface of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c and the fourth insulating layer 11d as in the fifth embodiment, then combined with the presence of the second outer via-hole conductor 201b, the length of the green body 10 in the height direction T becomes larger in the region AR3, so the common mode choke coil 1 may be partially deformed. The influence of such deformation in the region AR3 is likely to spread to the vicinity of the region AR3. In contrast, if the fourth dummy conductor 300d is provided in the region AR4 located near the region AR3, the length of the region AR4 in the height direction T becomes larger and is likely to be consistent with the length in the height direction T of the region AR3. As a result, the influence of the deformation in the region AR3 is mitigated, thereby suppressing the deformation of the common mode choke coil 1.

[0124] The fourth dummy conductor 300d may also be disposed on the surface of the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e and the sixth insulating layer 11f, or may be disposed on the surface of a portion of the insulating layers among the first insulating layer 11a, the second insulating layer 11b, the third insulating layer 11c, the fourth insulating layer 11d, the fifth insulating layer 11e and the sixth insulating layer 11f.

[0125] It is preferred that the first outer via-hole conductor 201a and the second outer via-hole conductor 201b are point-symmetrical with respect to the center P of the insulating layer when viewed from the height direction T. In this case, the influence of deformation in the region AR1 and the influence of deformation in the region AR3 effectively cancel each other out, thereby suppressing deformation of the common mode choke coil 1. In addition, in the common mode choke coil 1, when there are a region AR2 in which the second dummy conductor 300b is provided and a region AR4 in which the fourth dummy conductor 300d is provided in addition to the region AR1 and the region AR3, these four regions are evenly arranged with respect to the center P of the insulating layer when viewed from the height direction T, thereby further suppressing deformation of the common mode choke coil 1.

[0126] It is preferable that the first outer via-hole conductor 201 a and the second outer via-hole conductor 201 b do not overlap each other when viewed from the height direction T, but they may overlap each other.

[0127] None of the first dummy conductor 300a, the second dummy conductor 300b, the third dummy conductor 300c and the fourth dummy conductor 300d may be provided on the surface of the seventh insulating layer 11g, or at least one of the first dummy conductor 300a, the second dummy conductor 300b, the third dummy conductor 300c and the fourth dummy conductor 300d may be provided.

[0128] None of the first dummy conductor 300a, the second dummy conductor 300b, the third dummy conductor 300c and the fourth dummy conductor 300d may be provided on the surface of the eighth insulating layer 11h, or at least one of the first dummy conductor 300a, the second dummy conductor 300b, the third dummy conductor 300c and the fourth dummy conductor 300d may be provided.

[0129] Examples of the constituent material of the first dummy conductor 300 a , the second dummy conductor 300 b , the third dummy conductor 300 c , and the fourth dummy conductor 300 d include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0130] It is preferred that the constituent materials of the first dummy conductor 300a, the second dummy conductor 300b, the third dummy conductor 300c, and the fourth dummy conductor 300d are the same. In this case, it is preferred that the constituent materials of the first dummy conductor 300a, the second dummy conductor 300b, the third dummy conductor 300c, and the fourth dummy conductor 300d are the same as the constituent materials of the conductor portion such as the coil conductor provided on the surface of the same insulating layer. Thus, the conductor portion such as the coil conductor and the dummy conductor can be formed on the surface of the same insulating layer at the same timing, thereby improving manufacturing efficiency.

[0131] In the common mode choke coil 1, the first coil 31 is composed of four coil conductors, namely, a first coil conductor 41a, a second coil conductor 41b, a third coil conductor 41c and a seventh coil conductor 41g, but can also be composed of three coil conductors respectively arranged on the surfaces of three insulating layers, or can be composed of more than five coil conductors respectively arranged on the surfaces of more than five insulating layers.

[0132] In the common mode choke coil 1, the second coil 32 is composed of four coil conductors, namely, a fourth coil conductor 41d, a fifth coil conductor 41e, a sixth coil conductor 41f and an eighth coil conductor 41h, but can also be composed of three coil conductors respectively arranged on the surfaces of three insulating layers, or can be composed of more than five coil conductors respectively arranged on the surfaces of more than five insulating layers.

[0133] In the common mode choke coil 1 , the base body 10 is composed of the ferrite layer 12 , the glass ceramic layer 11 , and the ferrite layer 13 , but may be composed of only the glass ceramic layer 11 , or may have other structures as exemplified below.

[0134] Figure 8 It is a schematic perspective view showing another example of the common mode choke coil of the present invention.

[0135] like Figure 8 As shown, in the common mode choke coil 2, the base body 10 has a glass ceramic layer 14, a ferrite layer 12, a glass ceramic layer 11, a ferrite layer 13, and a glass ceramic layer 15 in order from the first main surface 10c toward the second main surface 10d. As a result, in the base body 10, structural defects such as peeling between the glass ceramic layer 11 and the ferrite layer 12 and peeling between the glass ceramic layer 11 and the ferrite layer 13 are suppressed.

[0136] The glass ceramic layer 14 and the glass ceramic layer 15 may each have a single-layer structure or a multi-layer structure.

[0137] The glass ceramic material constituting glass ceramic layer 14 and glass ceramic layer 15 is preferably the same as the glass ceramic material constituting glass ceramic layer 11 .

[0138] [Manufacturing method of common mode choke coil]

[0139] The common mode choke coil of the present invention is produced, for example, by the following method.

[0140] <Production of glass ceramic materials>

[0141] First, K2O, B2O3, SiO2, and Al2O3 are weighed and mixed in a predetermined ratio. Next, the obtained mixture is fired to melt it. Then, the obtained melt is rapidly cooled to produce a glass material.

[0142] The composition of the preferred glass material is: K is greater than 0.5 weight % and less than 5 weight % when converted to K2O, B is greater than 10 weight % and less than 25 weight % when converted to B2O3, Si is greater than 70 weight % and less than 85 weight % when converted to SiO2, and Al is greater than 0 weight % and less than 5 weight % when converted to Al2O3.

[0143] Then, SiO2, Al2O3, etc. are added as fillers to the glass material to produce a glass ceramic material.

[0144] <Production of glass ceramic sheets>

[0145] First, a glass ceramic slurry is prepared by mixing a glass ceramic material, an organic binder such as a polyvinyl butyral resin, an organic solvent such as ethanol or toluene, a plasticizer, etc. Next, the glass ceramic slurry is formed into a sheet of a predetermined thickness by a doctor blade method, and then punched into a predetermined shape to prepare a glass ceramic sheet.

[0146] <Production of ferrite materials>

[0147] First, Fe2O3, ZnO, CuO and NiO are weighed to a predetermined ratio. Each oxide may contain inevitable impurities. Next, these oxides are wet mixed and then crushed. At this time, additives such as Mn3O4, Co3O4, SnO2, Bi2O3, SiO2, etc. may also be added. Then, the obtained crushed material is dried and pre-fired. In this way, a powdered ferrite material is produced.

[0148] The composition of the ferrite material is preferably: Fe2O3 is 40 mol% to 49.5 mol%, ZnO is 5 mol% to 35 mol%, CuO is 6 mol% to 12 mol%, and NiO is 8 mol% to 40 mol%.

[0149] <Production of ferrite sheets>

[0150] First, a ferrite material, an organic binder such as a polyvinyl butyral resin, an organic solvent such as ethanol or toluene, etc. are mixed and then crushed to produce a ferrite slurry. Next, the ferrite slurry is formed into a sheet of a predetermined thickness by a doctor blade method or the like, and then punched into a predetermined shape to produce a ferrite sheet.

[0151] <Formation of Conductor Pattern>

[0152] Conductive paste such as Ag paste is applied to each glass ceramic sheet by screen printing or the like to form a conductive paste such as Ag paste. Figure 2 The coil conductor pattern corresponding to the coil conductor shown in FIG. Figure 2 The lead-out electrode conductor pattern corresponding to the lead-out electrode shown in FIG. Figure 2 The pad portion shown in the figure corresponds to the pad portion conductor pattern, and Figure 2 The via hole conductor pattern corresponding to the via hole conductor shown in FIG. Figure 2 The dummy conductor shown corresponds to the conductor pattern for the dummy conductor. When forming the conductor pattern for the via hole conductor, a via hole is formed in advance by irradiating a predetermined portion of the glass ceramic sheet with laser light, and the via hole is filled with a conductive paste.

[0153] <Production of laminated blocks>

[0154] First, follow Figure 2 The glass ceramic sheets on which the conductor patterns are formed are stacked in the height direction in the order shown. A predetermined number of glass ceramic sheets on which the conductor patterns are not formed may be further stacked on both sides in the height direction of the stacked body.

[0155] Next, a predetermined number of ferrite sheets are stacked on both sides of the stacked body of glass ceramic sheets in the height direction. A predetermined number of glass ceramic sheets may be further stacked on both sides of the stacked body in the height direction.

[0156] Then, the laminated body of the glass ceramic sheet and the ferrite sheet is pressure-bonded by a hot isotropic pressing (WIP) process or the like to produce a laminated body block.

[0157] <Making of blank and coil>

[0158] First, the stacked body block is cut into a specified size using a cutting machine or the like, thereby making a monolithic chip. Next, the monolithic chip is fired. At this time, the glass ceramic sheet and the ferrite sheet become insulating layers respectively, and the conductor pattern for the coil conductor, the conductor pattern for the lead electrode, the conductor pattern for the pad portion, the conductor pattern for the via conductor and the conductor pattern for the dummy conductor become the coil conductor, the lead electrode, the pad portion, the via conductor and the dummy conductor respectively. In this way, a blank formed by stacking a plurality of insulating layers in the height direction, a first coil arranged inside the blank, and a second coil arranged inside the blank and electrically insulated from the first coil are made. Here, the first lead electrode connected to one end of the first coil and the third lead electrode connected to one end of the second coil are exposed on the first side of the blank. The second lead electrode connected to the other end of the first coil and the fourth lead electrode connected to the other end of the second coil are exposed on the second side of the blank.

[0159] The green body may be rounded at its corners and edges by, for example, performing barrel grinding.

[0160] <Formation of external electrodes>

[0161] First, a conductive paste containing Ag and glass material is applied to at least four locations on the first side of the blank where the first lead electrode is exposed, the second side of the blank where the second lead electrode is exposed, the first side of the blank where the third lead electrode is exposed, and the second side of the blank where the fourth lead electrode is exposed. Next, a base electrode layer is formed on the surface of the blank by sintering the obtained coatings. Then, a Ni plating layer and a Sn plating layer are sequentially formed on the surface of each base electrode layer by electroplating. In this way, a first external electrode electrically connected to one end of the first coil, a second external electrode electrically connected to the other end of the first coil, a third external electrode electrically connected to one end of the second coil, and a fourth external electrode electrically connected to the other end of the second coil are formed.

[0162] According to the above, manufacturing Figure 1 , Figure 2 The common mode choke coil of the present invention is exemplified in etc.

[0163] [Example]

[0164] Hereinafter, embodiments of the common mode choke coil of the present invention will be described in more detail. However, the present invention is not limited to these embodiments.

[0165] [Example 1]

[0166] The common mode choke coil of Example 1 was manufactured by the following method.

[0167] <Production of glass ceramic materials>

[0168] First, K2O, B2O3, SiO2, and Al2O3 are weighed to a predetermined ratio and mixed in a platinum crucible. Next, the resulting mixture is melted by firing at a temperature of 1500°C to 1600°C. Then, the resulting melt is rapidly cooled to produce a glass material.

[0169] Next, the glass material is pulverized so that the average particle size D 50 The glass powder is prepared by making the average particle size D 50 The average particle size D is 0.5 μm or more and 2.0 μm or less. 50 The particle size is equivalent to 50% of the cumulative percentage based on volume. Then, SiO2 powder and Al2O3 powder are added to the glass powder to produce a glass ceramic material.

[0170] <Production of glass ceramic sheets>

[0171] First, glass ceramic material, organic binder such as polyvinyl butyral resin, organic solvent such as ethanol or toluene, plasticizer and PSZ medium are put into a ball mill for mixing, thereby preparing glass ceramic slurry. Next, the glass ceramic slurry is formed into a sheet with a thickness of 20 μm or more and 30 μm or less by a scraper method, and then punched into a rectangular shape to prepare a glass ceramic sheet.

[0172] <Production of ferrite materials>

[0173] First, Fe2O3, ZnO, CuO and NiO are weighed to a predetermined ratio. Next, these oxides, pure water and a dispersant are put into a ball mill together with a PSZ medium and mixed, and then crushed. Then, the obtained crushed product is dried and pre-fired at 700°C to 800°C for 2 hours to 3 hours. In this way, a powdered ferrite material is produced.

[0174] <Production of ferrite sheets>

[0175] First, a ferrite material, an organic binder such as a polyvinyl butyral resin, an organic solvent such as ethanol or toluene, and a PSZ medium are mixed in a ball mill and then crushed to prepare a ferrite slurry. Next, the ferrite slurry is formed into a sheet by a doctor blade method and then punched into a rectangular shape to prepare a ferrite sheet.

[0176] <Formation of Conductor Pattern>

[0177] Ag paste is applied to each glass ceramic sheet by screen printing to form Figure 2 The coil conductor pattern corresponding to the coil conductor shown in FIG. Figure 2 The lead-out electrode conductor pattern corresponding to the lead-out electrode shown in FIG. Figure 2 The pad portion shown in the figure corresponds to the pad portion conductor pattern, and Figure 2 The via hole conductor pattern corresponding to the via hole conductor shown in FIG. Figure 2 The dummy conductor shown corresponds to the conductor pattern for the dummy conductor. When forming the conductor pattern for the via hole conductor, a via hole is formed in advance by irradiating a predetermined portion of the glass ceramic sheet with laser light, and the via hole is filled with a conductive paste.

[0178] <Production of laminated blocks>

[0179] First, follow Figure 2 The glass ceramic sheets on which the conductor pattern is formed are stacked in the height direction in the order shown. A predetermined number of glass ceramic sheets on which the conductor pattern is not formed are further stacked on both sides in the height direction of the stack.

[0180] Next, a predetermined number of ferrite sheets are stacked on both sides of the stacked body of glass ceramic sheets in the height direction.

[0181] Then, the laminated body of the glass ceramic sheet and the ferrite sheet was pressed and bonded by hot isotropic pressing to produce a laminated body block. The pressing conditions were a temperature of 80° C. and a pressure of 100 MPa.

[0182] <Making of blank and coil>

[0183] First, the stacked body block is cut into a specified size using a cutting machine, thereby making a monolithic chip. Next, the monolithic chip is fired for more than 1 hour and less than 2 hours at a temperature above 860°C and below 920°C. At this time, the glass ceramic sheet and the ferrite sheet become insulating layers respectively, and further, the conductor pattern for the coil conductor, the conductor pattern for the lead electrode, the conductor pattern for the pad portion, the conductor pattern for the via conductor, and the conductor pattern for the dummy conductor become the coil conductor, the lead electrode, the pad portion, the via conductor, and the dummy conductor respectively. In this way, a blank in which multiple insulating layers are stacked in the height direction, a first coil arranged inside the blank, and a second coil arranged inside the blank and electrically insulated from the first coil are made. Here, the first lead electrode connected to one end of the first coil and the third lead electrode connected to one end of the second coil are exposed on the first side of the blank. The second lead electrode connected to the other end of the first coil and the fourth lead electrode connected to the other end of the second coil are exposed on the second side of the blank.

[0184] Next, the green body is placed in a rotary drum machine together with the medium, and the green body is subjected to drum grinding, thereby rounding the corners and ridges.

[0185] <Formation of external electrodes>

[0186] First, a conductive paste containing Ag and glass material is applied to at least four locations on the first side of the blank where the first lead electrode is exposed, the second side of the blank where the second lead electrode is exposed, the first side of the blank where the third lead electrode is exposed, and the second side of the blank where the fourth lead electrode is exposed. Next, a base electrode layer is formed on the surface of the blank by sintering the obtained coatings at 800°C. Then, a Ni plating layer and a Sn plating layer are sequentially formed on the surface of each base electrode layer by electroplating. In this way, a first external electrode electrically connected to one end of the first coil, a second external electrode electrically connected to the other end of the first coil, a third external electrode electrically connected to one end of the second coil, and a fourth external electrode electrically connected to the other end of the second coil are formed.

[0187] Based on the above, a common mode choke coil of Example 1 was manufactured. The common mode choke coil of Example 1 had a length of 0.65 mm in the longitudinal direction, a length of 0.50 mm in the width direction, and a length of 0.30 mm in the height direction.

[0188] [Comparative Example 1]

[0189] The common mode choke coil of Comparative Example 1 was manufactured in the same manner as the common mode choke coil of Example 1 except that the dummy conductor pattern was not formed. The size of the common mode choke coil of Comparative Example 1 was also the same as that of the common mode choke coil of Example 1.

[0190] [evaluate]

[0191] The DC resistance between the first external electrode and the second external electrode and the DC resistance between the third external electrode and the fourth external electrode were measured for the common mode choke coil of Example 1 and the common mode choke coil of Comparative Example 1. When the DC resistance between the first external electrode and the second external electrode was infinite, it was determined that the first coil was broken, and when the DC resistance between the third external electrode and the fourth external electrode was infinite, it was determined that the second coil was broken.

[0192] As a result, regarding the common mode choke coil of Example 1, there were no samples in which the first coil and the second coil were judged to be disconnected, and the occurrence rate of disconnection was 0 ppm.

[0193] On the other hand, for the common mode choke coil of Comparative Example 1, the sample judged to have a disconnection in the first coil was judged to have a disconnection in the second coil as well, and the disconnection rate was about 30ppm. Figure 4 In the cross section shown, the first outer via conductor is separated from the pad portion to be connected thereto. Figure 5 In the cross section shown, the second outer via conductor is separated from the pad portion to be connected thereto.

Claims

1. A common mode choke coil, characterized in that: have: The blank is formed by stacking a plurality of insulating layers in the height direction; A first coil is arranged inside the blank; A second coil, disposed inside the blank and electrically insulated from the first coil; A first external electrode is disposed on the surface of the blank and is electrically connected to one end of the first coil; A second external electrode is disposed on the surface of the green body and is electrically connected to the other end of the first coil; a third external electrode, disposed on the surface of the green body and electrically connected to one end of the second coil; as well as a fourth external electrode, disposed on the surface of the blank and electrically connected to the other end of the second coil, The first coil includes: a first coil conductor disposed on a surface of a first insulating layer, a second coil conductor disposed on a surface of a second insulating layer, and a third coil conductor disposed on a surface of a third insulating layer. The first coil conductor, the second coil conductor, and the third coil conductor are stacked together with the first insulating layer, the second insulating layer, and the third insulating layer in the height direction, and the first coil conductor, the second coil conductor, and the third coil conductor are electrically connected, The second coil includes: a fourth coil conductor disposed on a surface of a fourth insulating layer, a fifth coil conductor disposed on a surface of a fifth insulating layer, and a sixth coil conductor disposed on a surface of a sixth insulating layer. The fourth coil conductor, the fifth coil conductor, and the sixth coil conductor are stacked together with the fourth insulating layer, the fifth insulating layer, and the sixth insulating layer in the height direction, and the fourth coil conductor, the fifth coil conductor, and the sixth coil conductor are electrically connected, The second coil conductor is electrically connected to the third coil conductor via a first outer via-hole conductor, and the first outer via-hole conductor is provided at a position overlapping with outer peripheral ends of the second coil conductor and the third coil conductor when viewed from the height direction. A first dummy conductor is further provided on the surface of at least one of the first insulating layer, the fourth insulating layer, the fifth insulating layer, and the sixth insulating layer, which is provided at a position other than between the second insulating layer and the third insulating layer, wherein the first dummy conductor overlaps with the first outer via conductor when viewed from the height direction, and the first dummy conductor is electrically insulated from all the coil conductors, The first dummy conductor is electrically insulated from the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode.

2. The common mode choke coil according to claim 1, characterized in that All of the first insulating layer, the fourth insulating layer, the fifth insulating layer, and the sixth insulating layer are provided at positions other than between the second insulating layer and the third insulating layer. The first dummy conductor is disposed on surfaces of the first insulating layer, the fourth insulating layer, the fifth insulating layer, and the sixth insulating layer.

3. The common mode choke coil according to claim 2, characterized in that When a straight line is defined which passes through the center of the insulating layer when viewed from the height direction and extends in the long side direction of the insulating layer, A second dummy conductor is also provided on the surfaces of the first insulating layer, the second insulating layer, the third insulating layer, the fourth insulating layer, the fifth insulating layer and the sixth insulating layer. The second dummy conductor is symmetrical with the first outer via conductor relative to the straight line, and the second dummy conductor is electrically insulated from all the coil conductors.

4. The common mode choke coil according to any one of claims 1 to 3, characterized in that The fifth coil conductor is electrically connected to the sixth coil conductor via a second outer via-hole conductor, and the second outer via-hole conductor is provided at a position overlapping with outer peripheral ends of the fifth coil conductor and the sixth coil conductor when viewed from the height direction. A third dummy conductor is also provided on the surface of at least one of the first insulating layer, the second insulating layer, the third insulating layer and the fourth insulating layer, which is arranged at a position other than between the fifth insulating layer and the sixth insulating layer. When observed from the height direction, the third dummy conductor overlaps with the second outer via hole conductor, and the third dummy conductor is electrically insulated from all the coil conductors.

5. The common mode choke coil according to claim 4, characterized in that All of the first insulating layer, the second insulating layer, the third insulating layer, and the fourth insulating layer are provided at positions other than between the fifth insulating layer and the sixth insulating layer. The third dummy conductor is disposed on surfaces of the first insulating layer, the second insulating layer, the third insulating layer, and the fourth insulating layer.

6. The common mode choke coil according to claim 5, characterized in that When a straight line is defined which passes through the center of the insulating layer when viewed from the height direction and extends in the long side direction of the insulating layer, A fourth dummy conductor is also provided on the surfaces of the first insulating layer, the second insulating layer, the third insulating layer, the fourth insulating layer, the fifth insulating layer and the sixth insulating layer. The fourth dummy conductor is symmetrical with the second outer via conductor relative to the straight line, and the fourth dummy conductor is electrically insulated from all the coil conductors.

7. The common mode choke coil according to any one of claims 4 to 6, characterized in that The first outer via-hole conductor and the second outer via-hole conductor are symmetrical with respect to the center point of the insulating layer when viewed from the height direction.

8. The common mode choke coil according to any one of claims 1 to 7, characterized in that The first coil further includes a seventh coil conductor disposed on a surface of a seventh insulating layer, The second coil further includes an eighth coil conductor disposed on a surface of an eighth insulating layer.

9. The common mode choke coil according to claim 8, characterized in that In the blank, the seventh insulating layer, the fourth insulating layer, the third insulating layer, the second insulating layer, the fifth insulating layer, the sixth insulating layer, the first insulating layer, and the eighth insulating layer are sequentially stacked in the height direction.

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