Layered coil and layered coil array

Abstract

Provided are a layered coil and a layered coil array that reduce reductions in electrical characteristics. The present invention comprises an element assembly 10 at which magnetic layers are layered, a first coil 21 and a second coil 22 that are provided on the inside of the element assembly 10 and respectively include a plurality of first coil conductor layers 51 and a plurality of second coil conductor layers in the layering direction, a first external electrode 31 and a second external electrode 32 that are electrically connected to the first coil 21, and a third external electrode 33 and a fourth external electrode 34 that are electrically connected to the second coil 22. The first through fourth external electrodes are arranged at a bottom surface of the element assembly 10. The second coil 22 is provided at a position that is further from the bottom surface of the element assembly 10 than the first coil 21 in the layering direction. A first lead-out conductor 41 is provided on the inside of the element assembly 10 and connects the first external electrode 31 and an end of the first coil 21 that is an end of the first coil conductor layer 51 that is closest to the bottom surface, a second lead-out conductor 42 is provided on the inside of the element assembly 10 and connects the second external electrode 32 and another end of the first coil 21, a third lead-out conductor 43 is provided on the inside of the element assembly and connects the third external electrode 33 and an end of the second coil 22 that is an end of the second coil conductor layer 52 that is closest to the bottom surface, and a fourth lead-out conductor 44 is provided on the inside of the element assembly 10 and connects the fourth external electrode 34 and another end of the second coil 22. The second external electrode 32 and the third external electrode 33 are electrically connected.

Description

Stacked coil and stacked coil array

[0001] The present disclosure relates to stacked coils and stacked coil arrays.

[0002] In recent years, as equipment becomes more sophisticated, DC-DC converters in voltage conversion circuits have become more efficient at large currents, and the rated current of the power inductors used in these devices has also increased.As a method for achieving high current efficiency, a multi-phase system is being adopted, in which the output current from multiple inductors is added to increase the current.In this system, the output side of each inductor is electrically connected on the output circuit board.

[0003] Patent Document 1, which shows an example of the above-mentioned inductor, describes a stacked coil array for a DC-DC converter, which includes an element body including a magnetic layer containing magnetic particles, a first coil and a second coil built into the element body, and a first external electrode, a second external electrode, a third external electrode and a fourth external electrode provided on the surface of the element body and electrically connected to either one of the ends of the first coil and the second coil, respectively, wherein a non-magnetic layer is provided between the first coil and the second coil, and the first coil and the second coil are each formed by connecting a plurality of coil conductors in a stacking direction, and the above-mentioned The present invention discloses a stacked coil array for a DC-DC converter, in which an end drawn out from one of a plurality of coil conductors that is closest to the second coil is connected to the first external electrode, and the other end of the first coil is connected to the second external electrode, an end drawn out from one of the plurality of coil conductors of the second coil that is closest to the first coil is connected to the third external electrode, and the other end of the second coil is connected to the fourth external electrode, and the first external electrode and the third external electrode are connected to output terminals of switching elements of the DC-DC converter.

[0004] Japanese Patent Application Laid-Open No. 2020-61415

[0005] In the process of mounting the coil array described in Patent Document 1 on an output circuit board or the like, an unexpected voltage may be generated due to static electricity or the like, which may cause a large potential difference between the coils provided in the element body. The potential difference between the coils may then cause a short circuit near the coils closest to each other, reducing the insulation resistance between the coils and degrading the electrical characteristics of the coils.

[0006] A primary object of the present disclosure is to provide a stacked coil and a stacked coil array that reduce degradation of electrical characteristics.

[0007] a first coil provided inside the element body and including a plurality of first coil conductor layers in a stacking direction, and a second coil provided in the stacking direction and including a plurality of second coil conductor layers; a first external electrode and a second external electrode electrically connected to the first coil; a third external electrode and a fourth external electrode electrically connected to the second coil, wherein the first to fourth external electrodes are disposed on a bottom surface of the element body, and the second coil is provided at a position farther from the bottom surface of the element body than the first coil in the stacking direction; a first lead conductor provided inside the element body and connecting the first external electrode to an end of the first coil that is closest to the bottom surface; a second lead conductor provided inside the element body and connecting the other end of the first coil to the second external electrode; and a third lead conductor provided inside the element body and connecting the third external electrode to an end of the second coil that is closest to the bottom surface and a fourth lead conductor provided inside the element body and connecting the other end of the second coil and the fourth external electrode, wherein the second external electrode and the third external electrode are electrically connected.

[0008] a first coil provided inside the element body and including a plurality of first coil conductor layers in the stacking direction, a second coil provided in the stacking direction and including a plurality of second coil conductor layers in the stacking direction, a third coil provided in the stacking direction and including a plurality of third coil conductor layers in the stacking direction, a fourth coil provided in the stacking direction and including a plurality of fourth coil conductor layers in the stacking direction, a first external electrode and a second external electrode electrically connected to the first coil, a third external electrode and a fourth external electrode electrically connected to the second coil, a fifth external electrode and a sixth external electrode electrically connected to the third coil, and a seventh external electrode and an eighth external electrode electrically connected to the fourth coil, wherein the first to eighth external electrodes are disposed on a bottom surface of the element body, the second coil is provided at a position farther from the bottom surface of the element body in the stacking direction than the first coil, and the fourth coil is provided at a position farther from the bottom surface of the element body in the stacking direction than the third coil, a first lead conductor provided inside the element body and connecting the first external electrode to an end of the first coil of the first coil conductor layer that is closest to the bottom surface; a second lead conductor provided inside the element body and connecting the other end of the first coil to the second external electrode; a third lead conductor provided inside the element body and connecting the third external electrode to an end of the second coil of the second coil conductor layer that is closest to the bottom surface; a fourth lead conductor provided inside the element body and connecting the other end of the second coil to the fourth external electrode; a fifth lead conductor provided inside the element body and connecting the fifth external electrode to an end of the third coil of the third coil that is closest to the bottom surface; a sixth lead conductor provided inside the element body and connecting the other end of the third coil to the sixth external electrode; a seventh lead conductor provided inside the element body and connecting the seventh external electrode to an end of the fourth coil of the fourth coil that is closest to the bottom surface; an eighth lead conductor provided inside the element body and connecting the other end of the fourth coil and the eighth external electrode, wherein the second external electrode and the third external electrode are electrically connected,The sixth external electrode and the seventh external electrode are electrically connected to each other.

[0009] According to the present disclosure, it is possible to provide a stacked coil and a stacked coil array that reduce the deterioration of electrical characteristics. Specifically, because the second external electrode and the third external electrode are directly connected, even if an unexpected voltage is generated in the stacked coil or the like, it is possible to prevent short-circuiting between the coils within the element body and reduce the occurrence of a decrease in insulation resistance between the coils. Therefore, it is possible to reduce the deterioration of the electrical characteristics of the stacked coil or the like.

[0010] FIG. 1 is a perspective view schematically illustrating an example of a laminated coil according to a first embodiment. FIG. 2 is a perspective view schematically illustrating an example of the internal structure of the laminated coil according to the first embodiment. FIG. 3 is a perspective view of the internal structure shown in FIG. 2 , with the first coil, first lead conductor, and second lead conductor extracted. FIG. 4 is a perspective view of the internal structure shown in FIG. 2 , with the second coil, third lead conductor, and fourth lead conductor extracted. FIG. 5 is an exploded perspective view of the internal structure shown in FIG. 2 . FIG. 6 is a cross-sectional view taken along the arrow VI-VI in FIG. 5 . FIG. 7 is a perspective view schematically illustrating an example of the internal structure of a modified example of the first embodiment. FIG. 8A is a perspective view (top view) schematically illustrating an example of the internal structure of a laminated coil according to a second embodiment. FIG. 8B is a perspective view (bottom view) schematically illustrating an example of the internal structure of a laminated coil according to the second embodiment. FIG. 9 is an exploded perspective view of a portion of the internal structure of the laminated coil according to the second embodiment. Fig. 10 is a perspective view (top view) schematically showing an example of the internal structure of the stacked coil of the third embodiment. Fig. 11 is an exploded perspective view of a portion of the internal structure of the stacked coil of the third embodiment. Fig. 12A is a perspective view schematically showing an example of the internal structure of a stacked coil array of the present disclosure. Fig. 12B is a perspective view schematically showing an example of the internal structure of a stacked coil array of the present disclosure. Fig. 12C is a perspective view schematically showing an example of the internal structure of a stacked coil array of the present disclosure.

[0011] The stacked coil and stacked coil array of the present disclosure will be described below. Note that the present disclosure is not limited to the following configurations and may be modified as appropriate without departing from the gist of the present disclosure. Furthermore, a combination of multiple individual preferred configurations described below also constitutes the present disclosure.

[0012] The stacked coil and stacked coil array of the present disclosure are used in, for example, DC-DC converters, but can also be used in applications other than DC-DC converters.

[0013] In this specification, terms indicating the relationship between elements (e.g., "parallel," "orthogonal," etc.) and terms indicating the shape of elements do not only mean the strict literal form, but also mean a range of substantial equivalence, for example, a range including a difference of about a few percent. Note that in this specification, the direction in which the magnetic layers and conductor layers that make up the element body are stacked is referred to as the "stacking direction."

[0014] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0015] First Embodiment of Stacked Coil First, a first embodiment of a stacked coil according to the present disclosure will be described with reference to Figures 1 to 6. Figure 1 is a perspective view schematically illustrating an example of a stacked coil according to the first embodiment. Figure 2 is a perspective view schematically illustrating an example of the internal structure of the stacked coil according to the first embodiment. Figure 3 is a perspective view of the internal structure shown in Figure 2, with the first coil, the first lead conductor, and the second lead conductor extracted. Figure 4 is a perspective view of the internal structure shown in Figure 2, with the second coil, the third lead conductor, and the fourth lead conductor extracted. Figure 5 is an exploded perspective view of the internal structure shown in Figure 2. Figure 6 is a cross-sectional view taken along the arrows IV-IV in Figure 5. Note that the shape and arrangement of the stacked coil and its components are not limited to those shown in the figures.

[0016] 1 and 2 includes an element body 10, a first coil 21, a second coil 22, a first external electrode 31, a second external electrode 32, a third external electrode 33, a fourth external electrode 34, a first lead conductor 41, a second lead conductor 42, a third lead conductor 43, and a fourth lead conductor 44. Each of these components will be described in detail below.

[0017] -Element body- The element body 10 has, for example, a rectangular parallelepiped or approximately rectangular parallelepiped shape having six sides. The corners and ridges of the element body 10 may be rounded. A corner is a portion where three sides of the element body 10 intersect, and a ridge is a portion where two sides of the element body 10 intersect.

[0018] 1 and 2, the length direction, width direction, and height direction of the laminated coil 1 and the element body 10 are indicated as L direction, W direction, and T direction, respectively. The length direction L, width direction W, and height direction T are perpendicular to one another. The mounting surface of the laminated coil 1 is, for example, a surface (LW surface) parallel to the length direction L and width direction W.

[0019] 1 has a first main surface 11 and a second main surface 12 that face each other in a height direction T, a first end surface 13 and a second end surface 14 that face each other in a length direction L that is perpendicular to the height direction T, and a first side surface 15 and a second side surface 16 that face each other in a width direction W that is perpendicular to the length direction L and the height direction T. In the example shown in FIG. 1 , the first main surface 11 of the element body 10 corresponds to the bottom surface of the element body 10.

[0020] The element body 10 includes a magnetic layer S (see FIG. 5). The element body 10 preferably has a layered structure. Specifically, the element body 10 preferably includes multiple magnetic layers S in a stacking direction (for example, height direction T). In this embodiment, as shown in FIG. 5, the element body 10 may be configured by stacking magnetic layer groups G1 to G11, each including at least one magnetic layer S. Note that the boundaries between the layers in the layered structure of the element body 10 do not need to be clearly defined.

[0021] The magnetic layer group G1 has, as an example, two magnetic layers S, and constitutes the second main surface 12 of the element body 10.

[0022] The magnetic layer group G2 has, as an example, four magnetic layers S. The magnetic layers S are provided with second coil conductor layers 52, and these four second coil conductor layers 52 form one winding of the second coil 22.

[0023] As an example, the magnetic layer group G3 has one magnetic layer S. The magnetic layer S is provided with a conductor layer (via conductor) for connecting the second coil conductor layer 52 of the magnetic layer group G2 to the second coil conductor layer 52 of the magnetic layer group G4, and a fourth lead conductor 44 for electrically connecting the second coil conductor layer 52 to the fourth external electrode 34.

[0024] The magnetic layer group G4 has, as an example, four magnetic layers S. Second coil conductor layers 52 are provided on the magnetic layers S, and these four second coil conductor layers 52 form another winding of the second coil 22. In addition, fourth lead conductors 44 are provided at corners of the magnetic layer group G4.

[0025] As an example, the magnetic layer group G5 has two magnetic layers S. The magnetic layer S is provided with a third lead conductor 43 for electrically connecting the second coil conductor layer 52 and the third external electrode 33, and a fourth lead conductor 44 for electrically connecting the second coil conductor layer 52 and the fourth external electrode 34.

[0026] As an example, the magnetic layer group G6 has four magnetic layers S. The magnetic layers S are provided with first coil conductor layers 51, and these four first coil conductor layers 51 form one winding of the first coil 21. In addition, the magnetic layer group G6 has the above-mentioned fourth lead conductor 44 and third lead conductor 43 provided at one corner of each magnetic layer S.

[0027] As an example, the magnetic layer group G7 has one magnetic layer S. The magnetic layer S is provided with a conductor layer (via conductor) for connecting the first coil conductor layer 51 of the magnetic layer group G6 to the first coil conductor layer 51 of the magnetic layer group G8, and a second lead conductor 42 for electrically connecting the first coil conductor layer 51 to the second external electrode 32. In addition, the magnetic layer group G7 is provided with the above-mentioned fourth lead conductor 44 and third lead conductor 43 at corners on one side of each magnetic layer S.

[0028] As an example, the magnetic layer group G8 has four magnetic layers S. First coil conductor layers 51 are provided on the magnetic layers S, and these four first coil conductor layers 51 form another winding of the first coil 21. In addition, in the magnetic layer group G8, the above-mentioned fourth lead conductor 44 and third lead conductor 43 are provided at one corner of each magnetic layer S. Furthermore, a second lead conductor 42 is provided at the other corner of each magnetic layer S.

[0029] The magnetic layer group G9 includes, as an example, two magnetic layers S. The magnetic layers S are provided with a first lead conductor 41, a second lead conductor 42, a third lead conductor 43, and a fourth lead conductor 44 at their corners.

[0030] As an example, the magnetic layer group G10 has two magnetic layers S. The magnetic layer S is provided with a first extraction conductor 41, a fourth extraction conductor 44, and a conductor wiring H1 for directly connecting the second external electrode 32 and the third external electrode 33.

[0031] The magnetic layer group G11 includes, as an example, two magnetic layers S. The magnetic layers S are provided with a first external electrode 31, a second external electrode 32, a third external electrode 33, and a fourth external electrode .

[0032] The element body 10 having a laminated structure increases the degree of freedom in designing the laminated coil 1. For example, when manufacturing a laminated coil 1 that includes the first external electrode 31, the second external electrode 32, the third external electrode 33, and the fourth external electrode 34 on the bottom surface (first main surface 11) of the element body 10, it becomes easier to draw out the first coil 21 and the second coil 22 to the bottom surface side.

[0033] The magnetic layer S contains magnetic particles made of a magnetic material. The magnetic particles may be ferrite particles or particles (metal magnetic particles) of a metal magnetic material such as Fe, Co, Ni, or an alloy containing at least one of these. The magnetic particles are preferably Fe particles or Fe alloy particles. Preferred Fe alloys include Fe-Si based alloys, Fe-Si-Cr based alloys, Fe-Si-Al based alloys, Fe-Si-B-P-Cu-C based alloys, and Fe-Si-B-Nb-Cu based alloys.

[0034] The surfaces of the metal magnetic particles made of the above-mentioned metal magnetic material are preferably covered with an insulating coating. Covering the surfaces of the metal magnetic particles with an insulating coating can improve the insulation between the metal magnetic particles. Methods for forming the insulating coating on the surfaces of the metal magnetic particles include the sol-gel method and the mechanochemical method. The material constituting the insulating coating is preferably an oxide of P, Si, or the like. The insulating coating may also be an oxide film formed by oxidizing the surfaces of the metal magnetic particles. The thickness of the insulating coating is preferably 1 nm or more and 50 nm or less, more preferably 1 nm or more and 30 nm or less, and even more preferably 1 nm or more and 20 nm or less. For example, a cross section obtained by polishing a sample of a stacked coil array can be photographed with a scanning electron microscope (SEM), and the thickness of the insulating coating covering the surfaces of the metal magnetic particles can be measured from the obtained SEM photograph.

[0035] The average particle size of the metal magnetic particles in the magnetic layer S is preferably 1 μm or more and 30 μm or less, more preferably 1 μm or more and 20 μm or less, and even more preferably 1 μm or more and 10 μm or less. The average particle size of the metal magnetic particles in the magnetic layer can be measured by the procedure described below. A cross section obtained by cutting a sample of a laminated coil is photographed using an SEM at multiple locations (e.g., five locations) in an area (e.g., 130 μm × 100 μm). The obtained SEM images are analyzed using image analysis software (e.g., image analysis software WinROOF2021 (manufactured by Mitani Shoji Co., Ltd.)) to determine the circle-equivalent diameter of the metal magnetic particles. The average value of the obtained circle-equivalent diameters is taken as the average particle size of the metal magnetic particles.

[0036] Furthermore, when forming the element body 10, a heat treatment is performed. In this case, the metal magnetic particles contained in the element body 10 have an oxide film on their surfaces. This oxide film originates from the metal magnetic particles and is formed by the heat treatment. In the element body 10, adjacent metal magnetic particles are bonded to each other via the oxide film.

[0037] The base body 10 may include a non-magnetic layer between the first coil 21 and the second coil 22. By providing a non-magnetic layer between the first coil 21 and the second coil 22, it is possible to improve the insulation between the first coil 21 and the second coil 22 and prevent a short circuit between them.

[0038] The non-magnetic layer may contain a glass ceramic material, a non-magnetic ferrite material, or the like as a non-magnetic material. The non-magnetic layer preferably contains a non-magnetic ferrite material as a non-magnetic material. As the non-magnetic ferrite material, Fe is preferably Fe ２ O ３ A non-magnetic ferrite material having a composition of 40 mol % to 49.5 mol % in terms of Cu, 6 mol % to 12 mol % in terms of CuO, and the remainder being ZnO can be used. The non-magnetic material can contain Mn as an additive as needed. ３ O ４ , Co ３ O ４ , SnO ２ , Bi ２ O ３ and SiO ２ The non-magnetic layer may contain Zn--Cu ferrite, and may contain trace amounts of unavoidable impurities.

[0039] The thickness of the nonmagnetic layer can be measured using the procedure described below. A laminated coil sample is placed vertically and the sample is hardened with resin so that the LT plane is exposed. Polishing is completed using a polishing machine at a depth of approximately half of the sample's width in the W direction, exposing a cross section parallel to the LT plane. After polishing, the polished surface is processed by ion milling (Hitachi High-Tech Corporation IM4000 ion milling device) to remove any sagging of the internal conductor due to polishing. The approximate center of the nonmagnetic layer in the polished sample is photographed using an SEM, and the thickness of the approximate center of the nonmagnetic layer is measured from the obtained SEM photograph, which is defined as the thickness of the nonmagnetic layer.

[0040] The base body 10 may include a nonmagnetic portion between the multiple first coil conductor layers 51 that make up the first coil 21, or between the multiple second coil conductor layers 52 that make up the second coil 22. In this case, the nonmagnetic portion is provided in at least one location between adjacent coil conductor layers of the first coil conductor layer 51 and the second coil conductor layer 52. By providing a nonmagnetic portion between adjacent coil conductor layers, it is possible to prevent magnetic flux from leaking between the coil conductor layers.

[0041] The non-magnetic layer and the non-magnetic portion preferably have the same composition, for example, the non-magnetic layer and the non-magnetic portion preferably are made of Zn—Cu ferrite.

[0042] A first coil 21 and a second coil 22 are provided inside the element body 10. The first coil 21 and the second coil 22 are preferably magnetically coupled. One end of the first coil 21 and one end of the second coil 22 may be electrically connected as described below. Two coils including only the first coil 21 and the second coil 22 may be provided inside the element body 10, or three or more coils including the first coil 21 and the second coil 22 may be provided inside the element body 10.

[0043] -First Coil- The first coil 21 includes multiple first coil conductor layers 51 in the stacking direction (e.g., height direction T). Adjacent first coil conductor layers 51 are connected to each other through via conductors. The first coil 21 may have 1.75 turns by including first coil conductor layers 51 formed in two different magnetic layer groups in the stacking direction (see FIG. 3). The number of turns is not limited to 1.75 as shown in the illustrated example, and may be, for example, 2 or more, by stacking the first coil conductor layers 51 in the stacking direction.

[0044] The first coil conductor layers 51 preferably have the same thickness. The thickness of the first coil conductor layers 51 is also preferably equal to the thickness of the second coil conductor layers 52, which will be described later.

[0045] The first coil conductor layer 51 may be made of a metal conductor such as Ag, Cu, and / or Pd, and may be formed by printing a conductive paste on the magnetic layer S, for example.

[0046] FIG. 3 is a perspective view of the internal structure shown in FIG. 2, in which the first coil 21, the first lead conductor 41, and the second lead conductor 42 are extracted.

[0047] The first coil conductor layer 51 may include avoidance portions 60 that are arranged inside the second, third, and fourth lead conductors 42, 43, and 44 in a plan view from the stacking direction (e.g., the height direction T) in order to avoid the second, third, and fourth lead conductors 42, 43, and 44, and straight portions 65 that are connected to the avoidance portions 60. By providing the avoidance portions 60, the outer dimensions of the first coil can be increased to improve the coil characteristics, and interference between the second, third, and fourth lead conductors 42, 43, and 44 and the first coil conductor layer 51 can be reduced, allowing wiring to be appropriately drawn from the first coil 21 to the external electrode.

[0048] The avoidance portion 60 of the first coil conductor layer 51 only needs to be arranged inside the second extraction conductor 42 in a plan view from the stacking direction (e.g., the height direction T) so as to avoid at least the second extraction conductor 42. In other words, the first coil conductor layer 51 only needs to include the avoidance portion 60 for avoiding at least the second extraction conductor 42, and does not need to include the avoidance portion 60 for avoiding at least one of the third extraction conductor 43 and the fourth extraction conductor 44.

[0049] —Second Coil— The second coil 22 is provided at a position farther from the bottom surface (first main surface 11 ) of the element body 10 than the first coil 21 .

[0050] The second coil 22 includes multiple second coil conductor layers 52 in the stacking direction (e.g., the height direction T). Adjacent second coil conductor layers 52 are connected to each other via conductors. The second coil 22 may have a number of turns of 1.75 by including second coil conductor layers 52 formed in two different magnetic layer groups in the stacking direction (see FIG. 4 ). The number of turns is not limited to 1.75 as shown in the illustrated example, and may be, for example, two or more, by stacking the first coil conductor layers 51 in the stacking direction. The number of layers of the second coil conductor layers 52 may be the same as or different from the number of layers of the first coil conductor layers 51.

[0051] The second coil conductor layers 52 preferably have the same thickness. The thickness of the second coil conductor layers 52 is also preferably equal to the thickness of the first coil conductor layers 51.

[0052] The second coil conductor layer 52 may be made of a metal conductor such as Ag, Cu, and / or Pd. The second coil conductor layer 52 may be made of the same material as or a different material from the first coil conductor layer 51. The second coil conductor layer 52 may be formed, for example, by printing a conductive paste on the magnetic layer S.

[0053] FIG. 4 is a perspective view of the internal structure shown in FIG. 2, in which the second coil 22, the third lead conductor 43, and the fourth lead conductor 44 are extracted.

[0054] 4 , the second coil conductor layer 52 may include avoidance portions 60 that are arranged inside each of the fourth extraction conductors 44 in a plan view from the stacking direction (e.g., the height direction T) in order to avoid the fourth extraction conductors 44, and straight portions 65 that are connected to the avoidance portions 60. By providing the avoidance portions 60, the outer shape of the second coil can be increased to improve the coil characteristics, and interference with the fourth extraction conductor 44 can be reduced, allowing wiring to be appropriately drawn from the second coil 22 to the external electrode.

[0055] -External Electrodes- The external electrodes include a first external electrode 31, a second external electrode 32, a third external electrode 33, and a fourth external electrode 34. The first external electrode 31 and the second external electrode 32 are provided on the bottom surface (first main surface 11) of the element body 10 and are electrically connected to the first coil 21. The third external electrode 33 and the fourth external electrode 34 are provided on the bottom surface (first main surface 11) of the element body 10 and are electrically connected to the second coil 22. In the multilayer coil 1, the bottom surface (first main surface 11) of the element body 10 can be used as a mounting surface. That is, mounting on the bottom surface of the multilayer coil 1 becomes possible.

[0056] The first external electrode 31 acts as an input electrode for the first coil 21. The first external electrode 31 may be provided only on the first main surface 11 of the element body 10, or may be provided across the first main surface 11 of the element body 10 and at least one of the first end surface 13 and the second side surface 16.

[0057] The second external electrode 32 acts as an output electrode for the first coil 21. The second external electrode 32 may be provided only on the first main surface 11 of the element body 10, or may be provided across the first main surface 11 of the element body 10 and at least one of the second end surface 14 and the second side surface 16.

[0058] The third external electrode 33 acts as an output electrode for the second coil 22. The third external electrode 33 may be provided only on the first main surface 11 of the element body 10, or may be provided across the first main surface 11 of the element body 10 and at least one of the second end surface 14 and the first side surface 15.

[0059] The fourth external electrode 34 acts as an input electrode for the second coil 22. The fourth external electrode 34 may be provided only on the first main surface 11 of the element body 10, or may be provided across the first main surface 11 of the element body 10 and at least one of the first end surface 13 and the first side surface 15.

[0060] Because the external electrodes are configured as described above, when a current is supplied from the first external electrode 31 to the multilayer coil 1, the current flows in the first coil 21 in a clockwise direction when the first coil 21 is viewed in a plan view as shown in the perspective view of Fig. 2 . When a current is supplied from the fourth external electrode 34 to the second coil 22, the current flows in a counterclockwise direction when the second coil 22 is viewed in a plan view as shown in the perspective view of Fig. 2 . In other words, the direction of the current flowing in the first coil 21 is opposite to the direction of the current flowing in the second coil 22. In other words, when viewed from the output electrodes (the second external electrode 32 and the third external electrode 33), the winding direction of the first coil 21 is opposite to the winding direction of the second coil 22. Therefore, magnetic flux is generated from the top to the bottom at the central axis of the first coil 21, and magnetic flux is generated from the bottom to the top at the center axis of the second coil 22, so the coils are wound so that the magnetic flux of the first coil 21 and the magnetic flux of the second coil 22 cancel each other out. This makes it possible to obtain optimal characteristics as an inductor used in a multi-phase DC-DC converter.

[0061] In the laminated coil 1 of the present disclosure, the second external electrode 32 and the third external electrode 33 are directly connected. More specifically, in the laminated coil 1 of the first embodiment, the second lead conductor 42 and the third lead conductor 43, which will be described later, are directly connected. By directly conducting the output end of the first coil 21 and the output end of the second coil 22 in this manner, the generation of a potential difference between the two coils before mounting on a substrate is reduced. This makes it possible to reduce the possibility of an unexpected voltage occurring in the laminated coil before mounting on a substrate, causing a short circuit between the coils provided in the element body 10 and deteriorating the electrical characteristics of the inductor.

[0062] In a preferred arrangement of the external electrodes, the second external electrode 32 and the third external electrode 33 that constitute the output electrodes of the laminated coil 1 are arranged along one side that constitutes the outer edge of the element body 10. In other words, the second external electrode 32 and the third external electrode 33 are not arranged along a diagonal line of the element body 10 in a plan view. By arranging the external electrodes in this way, the output electrode and the input electrode can be aligned on the same side of the element body, and the wiring on the substrate to the laminated coil 1 can be simplified.

[0063] The first external electrode 31, the second external electrode 32, the third external electrode 33, and the fourth external electrode 34 may each be made of a conductive material such as Ag, Cu, and / or Pd. More preferably, the surfaces of these external electrodes may be provided with a plating layer of one or more materials selected from Ni, Sn, Cu, and Au. Providing a plating layer of the above material allows for proper mounting on a mounting board.

[0064] The thickness of each of the first external electrode 31, the second external electrode 32, the third external electrode 33 and the fourth external electrode 34 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

[0065] The thickness of the external electrodes such as the first external electrode 31 can be measured using the procedure described in "Thickness of the Nonmagnetic Layer." That is, the sample is polished using the method described above, and the external electrode portion is photographed using an SEM. In the obtained SEM photograph, one location at approximately the center of the external electrode is measured, and this is defined as the thickness of the external electrode.

[0066] -Lead Conductors- The lead conductors include a first lead conductor 41, a second lead conductor 42, a third lead conductor 43, and a fourth lead conductor 44. The first lead conductor 41, the second lead conductor 42, the third lead conductor 43, and the fourth lead conductor 44 are provided inside the element body 10.

[0067] The first extraction conductor 41 connects the end of the first coil 21, of the first coil conductor layer 51 that is closest to the bottom surface (first main surface 11) of the element body 10, to the first external electrode 31. The first extraction conductor 41 preferably extends along the stacking direction (e.g., the height direction T). The first extraction conductor 41 may have a stacked structure.

[0068] The second extraction conductor 42 connects the other end of the first coil 21 and the second external electrode 32. The second extraction conductor 42 preferably extends along the stacking direction (e.g., the height direction T). The second extraction conductor 42 may have a stacked structure.

[0069] The third lead conductor 43 connects the end of the second coil 22, of the second coil conductor layer 52 that is closest to the bottom surface (first main surface 11) of the element body 10, to the third external electrode 33. The third lead conductor 43 preferably extends along the stacking direction (e.g., the height direction T). The third lead conductor 43 may have a stacked structure.

[0070] The fourth extraction conductor 44 connects the other end of the second coil 22 and the fourth external electrode 34. The fourth extraction conductor 44 preferably extends along the stacking direction (e.g., the height direction T). The fourth extraction conductor 44 may have a stacked structure.

[0071] As described above, the second lead conductor 42 and the third lead conductor 43 are directly connected by the conductor wiring H1. This prevents the coils provided in the element body 10 from shorting out due to an unexpected voltage occurring in the multilayer coil, and reduces the occurrence of a decrease in insulation resistance between the coils. This reduces the deterioration of the electrical characteristics of the inductor.

[0072] The conductor wiring H1 may be made of a conductive material such as Ag, Cu, and / or Pd, similar to the first coil conductor layer 51, the second coil conductor layer 52, and the external electrodes. The conductor wiring H1 may be made of the same material as the first coil conductor layer 51, the second coil conductor layer 52, and the external electrodes, or may be made of a different material.

[0073] The size of the conductor wiring H1 may be such that the second lead conductor 42 and the third lead conductor 43 can be directly connected. For example, the size of the conductor wiring H1 is such that the conductive paste constituting the conductor wiring H1 can be easily printed, and the thickness in the stacking direction is preferably 10 μm to 100 μm, and the width perpendicular to the stacking direction is preferably 50 μm to 300 μm. In other words, the thickness of the conductor wiring H1 is preferably equal to or less than the width of the conductor wiring H1. Note that in this specification, the "width" refers to the width at the widest position in a cross section parallel to the LT plane, similar to that used to measure the thickness of the non-magnetic layer, taking into account that the width varies depending on the position.

[0074] Furthermore, the thickness D1 of the conductor wiring H1 is preferably equal to or less than the thickness D2 of the portion constituting one winding of the first coil 21 (or the second coil 22) (see FIG. 6 ). The width L1 of the conductor wiring H1 is preferably equal to or less than the width L2 of the portion constituting one winding of the first coil 21 (or the second coil 22) (see FIG. 2 ). By setting the conductor wiring H1 to this size, interference with the magnetic flux of the first coil 21 and the second coil 22 can be reduced, allowing for an appropriate direct connection between the second lead conductor 42 and the third lead conductor 43. One reason for designing the thickness of the conductor wiring H1 as described above is that, while a large current flows through the first coil 21 or the second coil 22 during operation as a DC-DC converter, low resistance is required. However, the conductor wiring H1, whose primary purpose is to reduce potential differences due to static electricity before mounting, barely allows current to flow through it. This reduces degradation of the stacked coil's characteristics.

[0075] Here, a preferred arrangement of the first to fourth lead conductors 41 to 44 is such that the second and third lead conductors 42 and 43, which are electrically connected to the output electrodes of the laminated coil 1, are arranged along one side that constitutes the outer edge of the element body 10. In other words, the second and third lead conductors 42 and 43 are not arranged along a diagonal line of the element body 10 in a plan view. By arranging the lead conductors in this manner, the output electrodes and input electrodes can be aligned in the same direction.

[0076] <Modification of the First Embodiment of the Stacked Coil> Next, a stacked coil according to a modification of the first embodiment will be described with reference to Fig. 7. Fig. 7 is a perspective view schematically showing an example of the internal structure of a modification of the first embodiment. This modification differs from the stacked coil of the first embodiment in that the coil conductor layers do not have an avoidance portion 60. The following description will focus on the differences from the stacked coil described in the first embodiment.

[0077] -First Coil- In this modification, the first coil conductor layer 51 of the first coil 21 is wound so as not to overlap, in plan view, with the third external electrode 33 and the fourth external electrode 34. In other words, the first coil conductor layer 51 of the first coil 21 is wound so as to be spaced apart from the third extraction conductor 43 and the fourth extraction conductor 44, in plan view.

[0078] - Second Coil - In this modification, the third lead conductor 43 and the fourth lead conductor 44, which are electrically connected to the ends of the second coil 22, are arranged outside the first coil conductor layer 51 of the first coil 21. In other words, the third lead conductor 43 and the fourth lead conductor 44, which are electrically connected to the ends of the second coil 22, are arranged so as not to overlap with the first coil 21 in a planar view. On the other hand, the second coil conductor layer 52 of the second coil 22 is arranged so as to overlap with the first lead conductor 41 and the second lead conductor 42 in a planar view.

[0079] According to the first coil 21 and the second coil 22, the second coil 22 can be disposed above the first coil 21 without providing an avoidance portion, which simplifies the manufacture of the laminated coil.

[0080] Second Embodiment of Multilayer Coil Next, a multilayer coil according to a second embodiment will be described with reference to FIGS. 8A, 8B, and 9. FIG. 8A is a perspective view (top view) schematically illustrating an example of the internal structure of the multilayer coil according to the second embodiment. FIG. 8B is a perspective view (bottom view) schematically illustrating an example of the internal structure of the multilayer coil according to the second embodiment. FIG. 9 is an exploded perspective view of a portion of the internal structure of the multilayer coil according to the second embodiment. The multilayer coil according to the second embodiment differs from the multilayer coil according to the first embodiment and the modified example of the first embodiment in that an insulating layer 70 is further provided on the first main surface 11 of the base body 10 and that the second external electrode 32 and the third external electrode 33 are directly connected without using the conductor wiring described in the first embodiment. The following description will focus on the differences from the multilayer coil according to the above-described embodiments.

[0081] -Element Body- In this embodiment, the magnetic layer groups G1 to G8 shown in FIG. 5 are stacked, and the magnetic layer groups G9 and G10 shown in FIG. 9 are stacked on the bottom side of the magnetic layer group G8.

[0082] The magnetic layer group G9 includes, as an example, two magnetic layers S. The magnetic layers S are provided with a first lead conductor 41, a second lead conductor 42, a third lead conductor 43, and a fourth lead conductor 44 at their corners.

[0083] The magnetic layer group G10, for example, has two magnetic layers S. The magnetic layers S are provided with electrode wiring H2 for directly connecting the first external electrode 31 and the fourth external electrode 34 to the second external electrode 32 and the third external electrode 33.

[0084] - Insulating Layer - The insulating layer 70 is a layer laminated on the first main surface 11 of the element body 10 (see FIGS. 1 and 9), and an example thereof is photoresist. The insulating layer 70 has openings formed in positions facing the first external electrode 31, the second external electrode 32, the third external electrode 33, and the fourth external electrode 34. The openings are filled with conductive members M that are electrically connected to the external electrodes.

[0085] For example, the conductive member M may be made of one or more plating materials selected from Ni, Sn, Cu, and Au, taking into consideration the bonding property with the mounting substrate.

[0086] In a preferred aspect of this embodiment, the planar area of ​​the conductive member M is preferably different from the planar area of ​​the external electrodes 31 to 34. This makes it possible to design the planar area of ​​the conductive member M to correspond to the size of the electrodes on the mounting board, even if the size of the electrodes on the mounting board differs from the size of the external electrodes. More preferably, the planar area of ​​the conductive member M is smaller than the planar area of ​​the external electrodes 31 to 34. This makes it possible to correctly align the position of the conductive member M with the insulating layer, even if the position of the external electrodes is shifted due to compression or firing of the element body.

[0087] -External electrode- In the laminated coil of this embodiment, the second external electrode 32 and the third external electrode 33 are electrically connected by electrode wiring H2 that directly connects the second external electrode 32 and the third external electrode 33, without using conductor wiring that directly connects the second extraction conductor 42 and the third extraction conductor 43.

[0088] In the electrode wiring H2, it is preferable that the width dimension L4 perpendicular to the direction in which the second external electrode 32 extends toward the third external electrode 33 is approximately the same as the width dimension L3 of the second external electrode 32 and the width dimension L3 of the third external electrode (see Figure 8B).

[0089] Even if the second external electrode 32 and the third external electrode 33 are electrically connected by the electrode wiring H2 that directly connects them as in the multilayer coil of the second embodiment, it is possible to prevent the coils provided in the element body 10 from shorting out due to an unexpected voltage being generated in the multilayer coil, and to reduce the occurrence of a decrease in insulation resistance between the coils. Therefore, it is possible to reduce the deterioration of the electrical characteristics of the inductor.

[0090] <Third Embodiment of Multilayer Coil> Next, a multilayer coil according to a third embodiment will be described with reference to Figs. 10 and 11. Fig. 10 is a perspective view (top view) schematically showing an example of the internal structure of the multilayer coil according to the third embodiment, and Fig. 11 is an exploded perspective view of a portion of the internal structure of the multilayer coil according to the third embodiment. The multilayer coil according to the third embodiment differs from the multilayer coils according to the above-described embodiments in that it includes conductor wiring that directly connects the second lead conductor and the third lead conductor, and electrode wiring that directly connects the second external electrode and the third external electrode. The following description will focus on the differences from the multilayer coil according to the above-described embodiments.

[0091] -Element Body- In this embodiment, the magnetic layer groups G1 to G9 shown in FIG. 5 are stacked, and the magnetic layer groups G10 and G11 shown in FIG. 11 are stacked on the bottom side of the magnetic layer group G9.

[0092] As an example, the magnetic layer group G10 has two magnetic layers S. The magnetic layer S is provided with a first extraction conductor 41, a fourth extraction conductor 44, and a conductor wiring H1 for directly connecting the second external electrode 32 and the third external electrode 33.

[0093] As an example, the magnetic layer group G11 has two magnetic layers S. The magnetic layer S is provided with a first external electrode 31, a fourth external electrode 34, and electrode wiring H2 for directly connecting the second external electrode 32 and the third external electrode 33.

[0094] Further, an insulating layer 70 is provided below the magnetic layer group G11. The insulating layer 70 is as described in the second embodiment.

[0095] The multilayer coil of this embodiment includes conductor wiring H1 that directly connects the second lead conductor 42 and the third lead conductor 43, and electrode wiring H2 that directly connects the second external electrode 32 and the third external electrode 33. By using both the conductor wiring H1 and the electrode wiring H2 in this way, the second external electrode 32 and the third external electrode 33 can be electrically connected with lower resistance, and it is possible to reduce the deterioration of the electrical characteristics of the inductor due to a short circuit between the coils provided in the element body 10 caused by an unexpected voltage being generated in the multilayer coil.

[0096] In a preferred aspect of this embodiment, the width of the conductor wiring H1 connecting the second extraction conductor 42 and the third extraction conductor 43 may be narrower than the width of the electrode wiring connecting the second external electrode 32 and the third external electrode 33. In other words, the planar area of ​​the conductor wiring H1 in a planar view may be smaller than the planar area of ​​the electrode wiring H2. By making the width (or planar area) of the conductor wiring H1 relatively small, it is possible to reduce the amount of reduction in the volume of the magnetic particles in the magnetic layer S in a planar view. Therefore, it is possible to reduce the effect on the inductance value.

[0097] <Description of Stacked Coil Array> Next, the stacked coil array of the present disclosure will be described with reference to Figures 12A to 12C. Figures 12A, 12B, and 12C are perspective views each showing a schematic example of the internal structure of the stacked coil array of the present disclosure.

[0098] The stacked coil array 100 of the present disclosure may include a third coil and a fourth coil inside the base body 10, in addition to the first coil 21 and the second coil 22 described in the stacked coil above. The third coil has substantially the same structure as the first coil 21, and the fourth coil has substantially the same structure as the second coil 22. That is, the second coil is provided at a position farther from the bottom surface of the base body 10 in the stacking direction than the first coil, and the fourth coil is provided at a position farther from the bottom surface of the base body 10 in the stacking direction than the third coil. The third coil and the fourth coil are provided adjacent to the first coil 21 and the second coil 22. In other words, the third coil and the fourth coil are provided in a direction perpendicular to the stacking direction of the stacked coil with respect to the first coil 21 and the second coil 22.

[0099] The multilayer coil array 100 of the present disclosure may include a fifth external electrode 35 and a sixth external electrode 36 electrically connected to the third coil. Among the ends of the third coil, the end of the third coil conductor layer closest to the bottom surface may be connected to the fifth external electrode 35 by a fifth lead conductor 45. Furthermore, the other end of the third coil conductor layer may be connected to the sixth external electrode 36 by a sixth lead conductor 46.

[0100] The stacked coil array 100 of the present disclosure may include a seventh external electrode 37 and an eighth external electrode 38 electrically connected to the fourth coil. The fourth coil may be located farther from the bottom surface of the element body 10 in the stacking direction than the third coil. Of the ends of the fourth coil, the end of the fourth coil conductor layer closest to the bottom surface may be connected to the seventh external electrode 37 by a seventh lead conductor 47. Furthermore, the other end of the fourth coil conductor layer is connected to the eighth external electrode 38 by the eighth lead conductor 48.

[0101] Here, as a characteristic configuration of the multilayer coil array 100 of the present disclosure, the second external electrode 32 and the third external electrode 33 may be electrically connected, and the sixth external electrode 36 and the seventh external electrode 37 may be electrically connected. For example, in the multilayer coil array shown in Fig. 12, the second external electrode 32 and the third external electrode 33 are directly connected by conductor wiring H1, and the sixth external electrode 36 and the seventh external electrode 37 are directly connected by conductor wiring H1. Therefore, it is possible to prevent a short circuit between the first coil 21 and the second coil 22 and / or the third coil and the fourth coil.

[0102] 12B as an example, the multilayer coil array 100 is configured such that the third external electrode 33 and the sixth external electrode 36 are directly connected. In the illustrated example, the third external electrode 33 and the sixth external electrode 36 are directly connected by electrode wiring H2. With this configuration, in addition to preventing a short circuit between the first coil 21 and the second coil 22 in the vicinity where they are closest to each other, it is also possible to prevent a short circuit between the first coil and the third coil (or the fourth coil) and between the second coil and the third coil (or the fourth coil).

[0103] 12C shows an example of a multilayer coil array 100 in which the third lead conductor 43 and the sixth lead conductor 46 are directly connected to each other. In the illustrated example, the third lead conductor 43 and the sixth lead conductor 46 are directly connected to each other by a conductor wiring H1. Even with this configuration, in addition to preventing a short circuit between the first coil 21 and the second coil 22, it is also possible to prevent a short circuit between the first coil and the third coil (or the fourth coil) and between the second coil and the third coil (or the fourth coil).

[0104] 12A to 12C illustrate a configuration in which six coils are provided inside an element body, but the present invention is not limited to this example, and the stacked coil array 100 may have four coils provided inside one element body, or may have four or more coils provided inside one element body. In this way, by providing a stacked coil array 100 in which multiple coils are provided inside an element body, it is possible to use the stacked coil array 100 in large current applications, and by forming the coils into an array, it is possible to reduce the mounting area and / or mounting costs.

[0105] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. For example, the second lead conductor and the third external electrode may be connected. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments, but should be defined by the claims. The technical scope of the present disclosure also includes all modifications within the meaning and scope of the claims.

[0106] The stacked coil and stacked coil array of the present disclosure are as follows. <1> An element body having magnetic layers stacked one on top of the other, a first coil provided inside the element body and including a plurality of first coil conductor layers in the stacking direction, a second coil provided with a plurality of second coil conductor layers in the stacking direction, a first external electrode and a second external electrode electrically connected to the first coil, and a third external electrode and a fourth external electrode electrically connected to the second coil, wherein the first to fourth external electrodes are arranged on a bottom surface of the element body, and the second coil is provided at a position farther from the bottom surface of the element body than the first coil in the stacking direction, a first lead conductor provided inside the element body and connecting the first external electrode to an end of the first coil that is closest to the bottom surface, a second lead conductor provided inside the element body and connecting the other end of the first coil to the second external electrode, and a third lead conductor provided inside the element body and connecting the third external electrode to an end of the second coil that is closest to the bottom surface, A multilayer coil comprising: a fourth lead conductor provided inside the element body and connecting the other end of the second coil and the fourth external electrode, wherein the second external electrode and the third external electrode are electrically connected. <2> The multilayer coil according to <1>, wherein the second lead conductor and the third lead conductor are directly connected by conductor wiring. <3> The multilayer coil according to <1> or <2>, wherein the second external electrode and the third external electrode are directly connected by electrode wiring. <4> The multilayer coil according to <1>, comprising: conductor wiring directly connecting the second lead conductor and the third lead conductor; and electrode wiring directly connecting the second external electrode and the third external electrode. <5> The multilayer coil according to any one of <1> to <4>, wherein the width of the conductor wiring connecting the second lead conductor and the third lead conductor is narrower than the width of the electrode wiring connecting the second external electrode and the third external electrode.<6> An element body having stacked magnetic layers; a first coil provided inside the element body and including a plurality of first coil conductor layers in the stacking direction; a second coil including a plurality of second coil conductor layers in the stacking direction; a third coil including a plurality of third coil conductor layers in the stacking direction; a fourth coil including a plurality of fourth coil conductor layers in the stacking direction; first and second external electrodes electrically connected to the first coil; a third and fourth external electrodes electrically connected to the second coil; a fifth and sixth external electrodes electrically connected to the third coil; and a seventh and eighth external electrodes electrically connected to the fourth coil, wherein the first to eighth external electrodes are disposed on a bottom surface of the element body; the second coil is provided at a position farther from the bottom surface of the element body than the first coil in the stacking direction; and the fourth coil is provided at a position farther from the bottom surface of the element body than the third coil in the stacking direction. a first lead conductor provided inside the element body and connecting the first external electrode to an end of the first coil of the first coil conductor layer that is closest to the bottom surface; a second lead conductor provided inside the element body and connecting the other end of the first coil to the second external electrode; a third lead conductor provided inside the element body and connecting the third external electrode to an end of the second coil of the second coil conductor layer that is closest to the bottom surface; a fourth lead conductor provided inside the element body and connecting the other end of the second coil to the fourth external electrode; a fifth lead conductor provided inside the element body and connecting the fifth external electrode to an end of the third coil of the third coil that is closest to the bottom surface; a sixth lead conductor provided inside the element body and connecting the other end of the third coil to the sixth external electrode; a seventh lead conductor provided inside the element body and connecting the seventh external electrode to an end of the fourth coil of the fourth coil that is closest to the bottom surface; an eighth lead conductor provided inside the element body and connecting the other end of the fourth coil and the eighth external electrode, wherein the second external electrode and the third external electrode are electrically connected, and the sixth external electrode and the seventh external electrode are electrically connected.<7> The multilayer coil array according to <6>, wherein the third external electrode and the sixth external electrode are directly connected. <8> The multilayer coil array according to <6> or <7>, wherein the third lead conductor and the third lead conductor are directly connected.

[0107] The stacked coil and stacked coil array of the present disclosure can be suitably used as electronic components that can reduce degradation of electrical characteristics.

[0108] REFERENCE SIGNS LIST 1 laminated coil 10 element body 11 first main surface 12 second main surface 13 first end surface 14 second end surface 15 first side surface 16 second side surface 21 first coil 22 second coil 31 first external electrode 32 second external electrode 33 third external electrode 34 fourth external electrode 35 fifth external electrode 36 sixth external electrode 37 seventh external electrode 38 eighth external electrode 41 first lead conductor 42 second lead conductor 43 third lead conductor 44 fourth lead conductor 45 fifth lead conductor 46 sixth lead conductor 47 seventh lead conductor 48 eighth lead conductor 51 first coil conductor layer 52 second coil conductor layer 60 avoidance portion 65 straight portion 70 insulating layer 100 laminated coil array G1 to G11 magnetic layer group H1 conductor wiring H2 Electrode wiring L1 to L4 Width dimension M Conductive member S Magnetic layer

Claims

1. A base body with a magnetic layer laminated thereon, a first coil provided inside the base body and including a plurality of first coil conductor layers in the lamination direction, a second coil including a plurality of second coil conductor layers in the lamination direction, a first external electrode and a second external electrode electrically connected to the first coil, a third external electrode and a fourth external electrode electrically connected to the second coil, and the first to fourth external electrodes are disposed on the bottom surface of the base body, the second coil is provided at a position farther from the bottom surface of the base body than the first coil in the lamination direction, a first lead conductor provided inside the base body and connecting an end of the first coil conductor layer closest to the bottom surface among the ends of the first coil and the first external electrode, a second lead conductor provided inside the base body and connecting the other end of the first coil and the second external electrode, a third lead conductor provided inside the base body and connecting an end of the second coil conductor layer closest to the bottom surface among the ends of the second coil and the third external electrode, a fourth lead conductor provided inside the base body and connecting the other end of the second coil and the fourth external electrode, and the second external electrode and the third external electrode are electrically connected, a multilayer coil.

2. The second lead conductor and the third lead conductor are directly connected by a conductor wiring, The multilayer coil according to Claim 1.

3. The second external electrode and the third external electrode are directly connected by an electrode wiring The multilayer coil according to Claim 1.

4. A conductor wiring directly connecting the second lead conductor and the third lead conductor, and an electrode wiring directly connecting the second external electrode and the third external electrode, The multilayer coil according to Claim 1.

5. The width of the conductor wiring connecting the second lead conductor and the third lead conductor is narrower than the width of the electrode wiring connecting the second external electrode and the third external electrode The multilayer coil according to Claim 4.

6. A base body with a magnetic layer laminated thereon, a first coil provided inside the base body and including a plurality of first coil conductor layers in the lamination direction, a second coil including a plurality of second coil conductor layers in the lamination direction, a third coil including a plurality of third coil conductor layers in the lamination direction, a fourth coil including a plurality of fourth coil conductor layers in the lamination direction, a first external electrode and a second external electrode electrically connected to the first coil, a third external electrode and a fourth external electrode electrically connected to the second coil; a fifth external electrode and a sixth external electrode electrically connected to the third coil; a seventh external electrode and an eighth external electrode electrically connected to the fourth coil, and the first to eighth external electrodes are disposed on the bottom surface of the element body; the second coil is provided at a position farther from the bottom surface of the element body than the first coil in the stacking direction; the fourth coil is provided at a position farther from the bottom surface of the element body than the third coil in the stacking direction; a first lead conductor provided inside the element body and connecting an end of the first coil conductor layer closest to the bottom surface among the ends of the first coil and the first external electrode; a second lead conductor provided inside the element body and connecting the other end of the first coil and the second external electrode; a third lead conductor provided inside the element body and connecting an end of the second coil conductor layer closest to the bottom surface among the ends of the second coil and the third external electrode; a fourth lead conductor provided inside the element body and connecting the other end of the second coil and the fourth external electrode; a fifth lead conductor provided inside the element body and connecting an end of the third coil conductor layer closest to the bottom surface among the ends of the third coil and the fifth external electrode; a sixth lead conductor provided inside the element body and connecting the other end of the third coil and the sixth external electrode; a seventh lead conductor provided inside the element body and connecting an end of the fourth coil conductor layer closest to the bottom surface among the ends of the fourth coil and the seventh external electrode; an eighth lead conductor provided inside the element body and connecting the other end of the fourth coil and the eighth external electrode; the second external electrode and the third external electrode are electrically connected; and the sixth external electrode and the seventh external electrode are electrically connected, a stacked coil array.

7. The stacked coil array according to claim 6, wherein the third external electrode and the sixth external electrode are directly connected.

8. The stacked coil array according to claim 6, wherein the third lead conductor and the sixth lead conductor are directly connected.