Stacked coils and stacked coil arrays

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

Technical Field

[0001] The present disclosure relates to a multilayer coil and a multilayer coil array.

Background Art

[0002] In recent years, due to the high functionality of devices, the DC-DC converters in voltage conversion circuits have been evolving towards high current and high efficiency, and the rated current of the power inductors used in these devices has also been increasing. As a method for achieving high current and high efficiency, a multi-phase method that adds the output currents from multiple inductors to increase the current is being adopted. In this method, the output sides of the inductors are electrically connected on the output circuit board of each inductor.

[0003] Patent Document 1, which shows an example of the above inductor, includes a body containing a magnetic layer containing magnetic particles, a first coil and a second coil built into the body, and first external electrodes, second external electrodes, third external electrodes, and fourth external electrodes provided on the surface of the body and electrically connected to any one of the ends of the first coil and the second coil, respectively. It is a multilayer coil array for a DC-DC converter, in which a non-magnetic layer is provided between the first coil and the second coil, the first coil and the second coil are each formed by connecting a plurality of coil conductors in the stacking direction, and the end portion drawn from the coil conductor closest to the second coil among the plurality of coil conductors of the first coil is connected to the first external electrode, and the other end portion of the first coil is connected to the second external electrode, and the end portion drawn from the coil conductor closest to the first coil among the plurality of coil conductors of the second coil is connected to the third external electrode, and the other end portion of the second coil is connected to the fourth external electrode, and the first external electrode and the third external electrode are connected to the output terminals of the switching elements of the DC-DC converter. A multilayer coil array for a DC-DC converter is disclosed.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-61415 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] During the process of mounting the coil array described in Patent Document 1 onto an output circuit board or the like, unexpected voltages may be generated due to static electricity, etc., potentially causing a large potential difference between the coils provided within the device. This potential difference could lead to a short circuit near where the coils are closest, reducing the insulation resistance between the coils and potentially degrading the electrical characteristics of the coils.

[0006] The primary object of this disclosure is to provide a multilayer coil and a multilayer coil array that reduce the degradation of electrical characteristics. [Means for solving the problem]

[0007] The laminated coil of this disclosure is A base body with stacked magnetic layers, A first coil is provided inside the aforementioned body, and includes a plurality of first coil conductor layers in the stacking direction, and a second coil includes 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, The device comprises a third external electrode and a fourth external electrode electrically connected to the second coil, The first to fourth external electrodes are arranged on the bottom surface of the body. The second coil is provided at a position further from the bottom surface of the base body than the first coil in the stacking direction. A first lead conductor is provided inside the body and connects the end of the first coil conductor layer closest to the bottom surface with the first external electrode, A second lead conductor is provided inside the aforementioned body and connects the other end of the first coil to the second external electrode, A third lead conductor is provided inside the main body and connects the end of the second coil conductor layer closest to the bottom surface with the third external electrode, The body comprises a fourth lead conductor provided inside the main body, which connects the other end of the second coil to the fourth external electrode, The second external electrode and the third external electrode are electrically connected.

[0008] Furthermore, the stacked coil array of this disclosure is A base body with stacked magnetic layers, The above-mentioned body is provided with a first coil comprising a plurality of first coil conductor layers in the stacking direction, a second coil comprising a plurality of second coil conductor layers in the stacking direction, a third coil comprising a plurality of third coil conductor layers in the stacking direction, and a fourth coil comprising 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, The third and fourth external electrodes are electrically connected to the second coil, The third coil is electrically connected to a fifth external electrode and a sixth external electrode, The fourth coil is electrically connected to a seventh external electrode and an eighth external electrode, The first to eighth external electrodes are arranged on the bottom surface of the body. The second coil is provided at a position further from the bottom surface of the base body than the first coil in the stacking direction. The fourth coil is provided at a position further from the bottom surface of the base body than the third coil in the stacking direction. A first lead conductor is provided inside the body and connects the end of the first coil conductor layer closest to the bottom surface with the first external electrode, A second lead conductor is provided inside the aforementioned body and connects the other end of the first coil to the second external electrode, A third lead conductor is provided inside the main body and connects the end of the second coil conductor layer closest to the bottom surface with the third external electrode, The body comprises a fourth lead conductor provided inside the main body, which connects the other end of the second coil to the fourth external electrode, A fifth lead conductor is provided inside the body and connects the end of the third coil conductor layer closest to the bottom surface with the fifth external electrode, A sixth lead conductor is provided inside the aforementioned body and connects the other end of the third coil to the sixth external electrode, A seventh lead conductor is provided inside the body and connects the end of the fourth coil conductor layer closest to the bottom surface with the seventh external electrode, The body comprises an eighth lead conductor provided inside the main body, which connects the other end of the fourth coil to the eighth external electrode, The second external electrode and the third external electrode are electrically connected, The sixth external electrode and the seventh external electrode are electrically connected. [Effects of the Invention]

[0009] This disclosure provides a multilayer coil and a multilayer coil array that reduce the degradation of electrical characteristics. Specifically, because the second external electrode and the third external electrode are directly connected, even if an unexpected voltage occurs in the multilayer coil, it prevents short circuits between the coils within the element and reduces the phenomenon of reduced insulation resistance between coils. Therefore, the degradation of the electrical characteristics of the multilayer coil can be reduced. [Brief explanation of the drawing]

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

MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, the multilayer coil and the multilayer coil array of the present disclosure will be described. Note that the present disclosure is not limited to the following configurations, and may be appropriately changed without departing from the gist of the present disclosure. Also, combinations of a plurality of the individual preferred configurations described below are also within the scope of the present disclosure.

[0012] The stacked coils and stacked coil arrays of this disclosure are used, for example, in DC-DC converters. The stacked coils and stacked coil arrays of this disclosure are also applicable to applications other than DC-DC converters.

[0013] In this specification, terms describing relationships between elements (e.g., "parallel," "orthogonal," etc.) and terms describing the shape of elements mean not only strictly defined aspects but also substantially equivalent ranges, such as ranges with differences of a few percent. In this specification, the direction in which the magnetic layer and conductive layer constituting the element are stacked is referred to as the "stacking direction."

[0014] The drawings shown below are schematic representations, and their dimensions, aspect ratios, and scales may differ from those of the actual product.

[0015] <First embodiment of a laminated coil> First, a first embodiment of the laminated coil of this disclosure will be described with reference to Figures 1 to 6. Figure 1 is a schematic perspective view showing an example of the laminated coil of the first embodiment, Figure 2 is a schematic perspective view showing an example of the internal structure of the laminated coil of the first embodiment, Figure 3 is a perspective view showing the first coil, first lead conductor, and second lead conductor extracted from the internal structure shown in Figure 2, Figure 4 is a perspective view showing the second coil, third lead conductor, and fourth lead conductor extracted from the internal structure shown in Figure 2, Figure 5 is an exploded perspective view of the internal structure shown in Figure 2, and Figure 6 is a cross-sectional view in the direction of the arrow IV-IV in Figure 5. Note that the shape and arrangement of the laminated coil and each component are not limited to the examples shown.

[0016] The laminated coil 1 shown in Figures 1 and 2 comprises a base 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 component will be described in detail below.

[0017] -Base model- The base body 10 is, for example, a rectangular prism shape or a roughly rectangular prism shape having six faces. The corners and edges of the base body 10 may be rounded. The corners are the parts where three faces of the base body 10 intersect, and the edges are the parts where two faces of the base body 10 intersect.

[0018] Figures 1 and 2 show the length, width, and height directions of the laminated coil 1 and the base body 10 as the L, W, and T directions, respectively. The length direction L, the width direction W, and the height direction T are orthogonal to each other. The mounting surface of the laminated coil 1 is, for example, a surface parallel to the length direction L and the width direction W (LW surface).

[0019] The body 10 shown in Figure 1 has a first main surface 11 and a second main surface 12 that are opposite to the height direction T, a first end surface 13 and a second end surface 14 that are opposite to the length direction L which is perpendicular to the height direction T, and a first side surface 15 and a second side surface 16 that are opposite to the width direction W which is perpendicular to both the length direction L and the height direction T. In the example shown in Figure 1, the first main surface 11 of the body 10 corresponds to the bottom surface of the body 10.

[0020] The base body 10 includes a magnetic layer S (see Figure 5). Preferably, the base body 10 has a laminated structure. Specifically, it is preferable that the base body 10 includes a plurality of magnetic layers S in the stacking direction (e.g., the height direction T). In this embodiment, as shown in Figure 5, it may be constructed by stacking magnetic layer groups G1 to G11, each containing at least one magnetic layer S. Note that the boundaries between each layer of the laminated structure of the base body 10 do not need to be clearly visible.

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

[0022] Magnetic layer group G2 has, for example, four magnetic layers S. A second coil conductor layer 52 is provided in each magnetic layer S, and these four second coil conductor layers 52 constitute one winding of the second coil 22.

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

[0024] The magnetic layer group G4 has, for example, four magnetic layers S. A second coil conductor layer 52 is provided in the magnetic layer S, and these four second coil conductor layers 52 constitute the other windings of the second coil 22. In addition, a fourth lead conductor 44 is provided at the corner of the magnetic layer group G4.

[0025] Magnetic layer group G5, as an example, 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] Magnetic layer group G6 has, for example, four magnetic layers S. A first coil conductor layer 51 is provided in each magnetic layer S, and these four first coil conductor layers 51 constitute one winding of the first coil 21. In addition, the magnetic layer group G6 has the aforementioned fourth lead conductor 44 and third lead conductor 43 provided at one corner of each magnetic layer S.

[0027] Magnetic layer group G7, for example, has one magnetic layer S. This magnetic layer S is provided with a conductor layer (via conductor) for connecting the first coil conductor layer 51 of magnetic layer group G6 and the first coil conductor layer 51 of magnetic layer group G8, and a second lead conductor 42 for electrically connecting the first coil conductor layer 51 and the second external electrode 32. In addition, the magnetic layer group G7 has the aforementioned fourth lead conductor 44 and third lead conductor 43 provided at one corner of each magnetic layer S.

[0028] Magnetic layer group G8 has, for example, four magnetic layers S. A first coil conductor layer 51 is provided in each magnetic layer S, and these four first coil conductor layers 51 constitute the other windings of the first coil 21. In addition, the magnetic layer group G8 has the aforementioned fourth lead conductor 44 and third lead conductor 43 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] Magnetic layer group G9 has, 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] The magnetic layer group G10 has, for example, two magnetic layers S. The magnetic layers S are provided with a first lead conductor 41 and a fourth lead conductor 44, and a conductor wiring H1 for directly connecting the second external electrode 32 and the third external electrode 33.

[0031] Magnetic layer group G11, for example, has 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 34.

[0032] Having a laminated structure in the base body 10 increases the design flexibility of the laminated coil 1. For example, when manufacturing a laminated coil 1 with a first external electrode 31, a second external electrode 32, a third external electrode 33, and a fourth external electrode 34 on the bottom surface (first main surface 11) of the base body 10, it becomes easier to pull out the first coil 21 and the second coil 22 towards the bottom surface.

[0033] The magnetic layer S contains magnetic particles made of a magnetic material. The magnetic particles may be particles of metallic magnetic materials such as Fe, Co, Ni, and alloys containing at least one of these (metallic magnetic particles) or ferrite particles. Preferably, the magnetic particles are Fe particles or Fe alloy particles. As for the Fe alloy, Fe-Si alloys, Fe-Si-Cr alloys, Fe-Si-Al alloys, Fe-Si-BP-Cu-C alloys, Fe-Si-B-Nb-Cu alloys, etc. are preferred.

[0034] The surface of the metallic magnetic particles made of the aforementioned metallic magnetic material is preferably covered with an insulating film. Covering the surface of the metallic magnetic particles with an insulating film increases the insulating properties between the metallic magnetic particles. Methods for forming the insulating film on the surface of the metallic magnetic particles include the sol-gel method and the mechanochemical method. The material constituting the insulating film is preferably an oxide such as P or Si. Alternatively, the insulating film may be an oxide film formed by the oxidation of the surface of the metallic magnetic particles. The thickness of the insulating film is preferably 1 nm to 50 nm, more preferably 1 nm to 30 nm, and even more preferably 1 nm to 20 nm. For example, the thickness of the insulating film covering the surface of the metallic magnetic particles can be measured from the obtained SEM image of a cross-section obtained by polishing a sample of a stacked coil array.

[0035] The average particle size of the metallic magnetic particles in the magnetic layer S is preferably 1 μm to 30 μm, more preferably 1 μm to 20 μm, and even more preferably 1 μm to 10 μm. The average particle size of the metallic 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., 5 locations) (e.g., 130 μm × 100 μm), and the obtained SEM images are analyzed using image analysis software (e.g., image analysis software WinROOF2021 (manufactured by Mitani Corporation)) to determine the equivalent circle diameter of the metallic magnetic particles. The average value of the obtained equivalent circle diameters is taken as the average particle size of the metallic magnetic particles.

[0036] Furthermore, heat treatment is applied when forming the base body 10. In this case, the metallic magnetic particles contained in the base body 10 have an oxide film on their surface. This oxide film originates from the metallic magnetic particles and is formed by the heat treatment. In the base body 10, adjacent metallic magnetic particles are joined 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, the insulation between the first coil 21 and the second coil 22 can be improved, and short circuits between them can be prevented.

[0038] The non-magnetic layer may contain glass ceramic materials and non-magnetic ferrite materials as non-magnetic materials. Preferably, the non-magnetic layer contains a non-magnetic ferrite material. As the non-magnetic ferrite material, a non-magnetic ferrite material having a composition in which Fe is 40 mol% to 49.5 mol% when converted to Fe2O3, Cu is 6 mol% to 12 mol% when converted to CuO, and the remainder is ZnO can be used. The non-magnetic material may contain Mn3O4, Co3O4, SnO2, Bi2O3, SiO2, etc. as additives as needed, and may contain trace amounts of unavoidable impurities. Preferably, the non-magnetic layer contains Zn-Cu ferrite.

[0039] The thickness of the non-magnetic layer can be measured using the following procedure. The laminated coil sample is placed vertically, and the area around the sample is sealed with resin. At this time, the LT surface is exposed. Polishing is completed with a polishing machine to a depth of approximately 1 / 2 in the W direction of the sample, exposing a cross section parallel to the LT surface. To remove any sagging of the internal conductor caused by polishing, the polished surface is processed after polishing using ion milling (Hitachi High-Tech Corporation IM4000 ion milling device). The approximate center of the non-magnetic layer in the polished sample is photographed with an SEM, and the thickness of the approximate center of the non-magnetic layer is measured from the obtained SEM image and defined as the thickness of the non-magnetic layer.

[0040] The element 10 may include non-magnetic portions between the multiple first coil conductor layers 51 constituting the first coil 21, or between the multiple second coil conductor layers 52 constituting the second coil 22. In this case, the non-magnetic portions are provided at least at one location between adjacent coil conductor layers among the first coil conductor layers 51 and the second coil conductor layers 52. By providing non-magnetic portions between adjacent coil conductor layers, leakage of magnetic flux into the space between coil conductor layers can be prevented.

[0041] It is preferable that the non-magnetic layer and the non-magnetic portion have the same composition. For example, it is preferable that the non-magnetic layer and the non-magnetic portion are composed of Zn-Cu ferrite.

[0042] Inside the base body 10 are a first coil 21 and a second coil 22. Preferably, the first coil 21 and the second coil 22 are magnetically coupled. In addition, one end of the first coil 21 and one end of the second coil 22 may be electrically connected as described later. The base body 10 may contain only two coils, including the first coil 21 and the second coil 22, or it may contain three or more coils, including the first coil 21 and the second coil 22.

[0043] -Coil 1- The first coil 21 includes a plurality of first coil conductor layers 51 in the stacking direction (e.g., the height direction T). Adjacent first coil conductor layers 51 are connected to each other 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 Figure 3). The number of turns is not limited to 1.75 as shown in the example, and may be 2 or more by stacking the first coil conductor layers 51 in the stacking direction.

[0044] It is preferable that the thickness of each first coil conductor layer 51 is the same. Furthermore, it is preferable that the thickness of the first coil conductor layer 51 is equivalent to the thickness of the second coil conductor layer 52, which will be described later.

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

[0046] Figure 3 is a perspective view showing the first coil 21, the first lead conductor 41, and the second lead conductor 42 extracted from the internal structure shown in Figure 2.

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

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

[0049] -Coil 2- The second coil 22 is positioned further away from the bottom surface (first main surface 11) of the base body 10 than the first coil 21.

[0050] The second coil 22 includes a plurality of 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 via conductors. The second coil 22 may have 1.75 turns by including second coil conductor layers 52 formed in two different magnetic layer groups in the stacking direction (see Figure 4). The number of turns is not limited to 1.75 as shown in the example, and may be 2 or more by stacking the first coil conductor layers 51 in the stacking direction. The number of stacked second coil conductor layers 52 may be the same as or different from the number of stacked first coil conductor layers 51.

[0051] It is preferable that the thickness of each second coil conductor layer 52 is the same. Furthermore, it is preferable that the thickness of the second coil conductor layer 52 is the same as the thickness of the first coil conductor layer 51.

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

[0053] Figure 4 is a perspective view showing the second coil 22, the third lead conductor 43, and the fourth lead conductor 44 extracted from the internal structure shown in Figure 2.

[0054] As shown in Figure 4, the second coil conductor layer 52 may include avoidance portions 60 positioned inside each of the fourth lead conductors 44 in a plan view from the stacking direction (e.g., the height direction T) to avoid the fourth lead conductors 44, and straight portions 65 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 lead conductors 44 can be reduced, allowing the wiring to be properly drawn out from the second coil 22 toward the external electrodes.

[0055] -External electrode- 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 base 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 base body 10 and are electrically connected to the second coil 22. In the stacked coil 1, the bottom surface (first main surface 11) of the base body 10 can be used as the mounting surface. That is, mounting on the bottom surface of the stacked coil 1 becomes possible.

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

[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 base body 10, or it may be provided spanning the first main surface 11 and at least one of the second end surface 14 and the second side surface 16 of the base body 10.

[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 base body 10, or it may be provided spanning the first main surface 11 and at least one of the second end surface 14 and the first side surface 15 of the base body 10.

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

[0060] As described above, the external electrodes are configured such that when current is supplied from the first external electrode 31 to the laminated coil 1, current flows through the first coil 21 in a clockwise direction when viewed in a plan view, as shown in the perspective view of the first coil 21 in Figure 2. Also, when current is supplied from the fourth external electrode 34, current flows through the second coil 22 in a counterclockwise direction when viewed in a plan view, as shown in the perspective view of the second coil 22 in Figure 2. In other words, the direction of the current flowing through the first coil 21 and the direction of the current flowing through the second coil 22 are opposite. To put this configuration in other words, when viewed from the output side electrodes (second external electrode 32 and third external electrode 33), the winding direction of the first coil 21 and the winding direction of the second coil 22 are opposite. Therefore, since magnetic flux is generated in the central axis of the first coil 21 from the top to the bottom, and magnetic flux is generated in the second coil 22 from the bottom to the top, the coils are wound in such a way 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 for use as an inductor in a multi-phase DC-DC converter.

[0061] Furthermore, in the laminated coil 1 of this 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 connecting the output end of the first coil 21 and the output end of the second coil 22 in this way, the generation of a potential difference between the two coils before board mounting is reduced. Therefore, it is possible to reduce the likelihood of a short circuit between coils provided in the base body 10 and a deterioration in the electrical characteristics of the inductor caused by an unexpected voltage being generated in the laminated coil before board mounting.

[0062] A preferred arrangement of external electrodes is such that the second external electrode 32 and the third external electrode 33, which constitute the output electrode of the laminated coil 1, are arranged along one side that forms the outer edge of the base body 10. In other words, the second external electrode 32 and the third external electrode 33 are not arranged along the diagonal of the base 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 base 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 composed of a conductive material such as Ag, Cu, and / or Pd. More preferably, a plating layer of one or more materials selected from Ni, Sn, Cu, and Au may be provided on the surface of these external electrodes. By providing a plating layer of the above materials, the electrodes can be properly mounted on a mounting substrate.

[0064] The thickness 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 external electrodes, such as the first external electrode 31, can be measured using the procedure described in "Thickness of the Non-magnetic Layer". That is, the sample is polished using the method described above, and the external electrode area is photographed with an SEM. In the obtained SEM image, one measurement is taken approximately in the center of the external electrode, and this measurement is defined as the thickness of the external electrode.

[0066] -Draw-out conductor- 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 located inside the main body 10.

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

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

[0069] The third lead conductor 43 connects the end of the second coil conductor layer 52 closest to the bottom surface (first main surface 11) of the base body 10 with 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 lead conductor 44 connects the other end of the second coil 22 to the fourth external electrode 34. Preferably, the fourth lead conductor 44 extends along the stacking direction (e.g., the height direction T). The fourth lead 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. Therefore, it is possible to prevent the coils provided within the element 10 from short-circuiting due to the generation of an unexpected voltage in the laminated coil, and to reduce the phenomenon of a decrease in the insulation resistance between coils. Therefore, the deterioration of the electrical characteristics of the inductor can be reduced.

[0072] The material of the conductor wiring H1 may be 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. Furthermore, the conductor wiring H1 may use the same material as the first coil conductor layer 51, the second coil conductor layer 52, and the external electrodes, or it may use a different material.

[0073] The size of the conductor wiring H1 may be such that it can directly connect the second lead conductor 42 and the third lead conductor 43. For example, the size of the conductor wiring H1 is such that it is easy to print the conductive paste that constitutes the conductor wiring H1, and it is preferable that the thickness in the lamination direction is 10 μm or more and 100 μm or less, and the width dimension perpendicular to the lamination direction is 50 μm or more and 300 μm or less. In other words, it is preferable that the thickness of the conductor wiring H1 is less than or equal to the width dimension of the conductor wiring H1. In this specification, "width dimension" refers to the width dimension at the position where the width dimension is widest in a cross section parallel to the LT surface, similar to the thickness measurement of the non-magnetic layer, taking into consideration that the width dimension varies depending on the position.

[0074] Furthermore, it is preferable that the thickness D1 of the conductor wiring H1 be less than or equal to the thickness D2 of the portion constituting one winding in the first coil 21 (or second coil 22) (see Figure 6). Also, it is preferable that the width dimension L1 of the conductor wiring H1 be less than or equal to the width dimension L2 of the portion constituting one winding in the first coil 21 (or second coil 22) (see Figure 2). By setting the size of the conductor wiring H1 in this way, interference with the magnetic flux of the first coil 21 and the second coil 22 is reduced, and the second lead conductor 42 and the third lead conductor 43 can be properly directly connected. Another reason for designing the thickness of the conductor wiring H1 as described above is that the first coil 21 or the second coil 22 requires low resistance because a large current flows through it when it operates as a DC-DC converter, but the conductor wiring H1 is mainly intended to reduce the potential difference due to static electricity before mounting, so almost no current flows through it. This reduces the degradation of the characteristics of the laminated coil.

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

[0076] <Modified example of the first embodiment of the laminated coil> Next, a modified laminated coil of the first embodiment will be described with reference to Figure 7. Figure 7 is a schematic perspective view showing an example of the internal structure of a modified version of the first embodiment. This modified version differs from the laminated coil of the first embodiment described above in that the coil conductor layer does not have a bypass portion 60. The following description will focus on the differences from the laminated coil described in the first embodiment.

[0077] -Coil 1- In this modified example, the first coil conductor layer 51 of the first coil 21 is wound so as not to overlap with the third external electrode 33 and the fourth external electrode 34 in a plan view. In other words, the first coil conductor layer 51 of the first coil 21 is wound spaced apart from the third lead conductor 43 and the fourth lead conductor 44 in a plan view.

[0078] -Coil 2- In this modified example, the third lead conductor 43 and the fourth lead conductor 44, which are electrically connected to the ends of the second coil 22, are located 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 plan 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 plan view.

[0079] With the first coil 21 and second coil 22 described above, the second coil 22 can be positioned above the first coil 21 without providing a clearance section, thus simplifying the manufacturing of the laminated coil.

[0080] <Second embodiment of a laminated coil> Next, the laminated coil of the second embodiment will be described with reference to Figures 8A, 8B, and 9. Figure 8A is a schematic perspective view (top view) showing an example of the internal structure of the laminated coil of the second embodiment, Figure 8B is a schematic perspective view (bottom view) showing an example of the internal structure of the laminated coil of the second embodiment, and Figure 9 is an exploded perspective view of a part of the internal structure of the laminated coil of the second embodiment. The laminated coil of the second embodiment differs from the laminated coil of the first embodiment and its modified form described above 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 laminated coil described in the above embodiments.

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

[0082] Magnetic layer group G9 has, 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] Magnetic layer group G10, as an example, has two magnetic layers S. The magnetic layers S are provided with a first external electrode 31 and a fourth external electrode 34, and electrode wiring H2 for directly connecting 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 base body 10 (see Figures 1 and 9), and photoresist is one example. The insulating layer 70 also has openings at positions facing the first external electrode 31, second external electrode 32, third external electrode 33, and fourth external electrode 34. Conductive members M that are electrically connected to the external electrodes are embedded in these openings.

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

[0086] In a preferred embodiment of this design, the planar area of ​​the conductive member M is preferably different from the planar area of ​​the external electrodes 31 to 34. This allows the planar area of ​​the conductive member M to be designed to correspond to the size of the electrodes on the mounting substrate, even if the size of the electrodes on the mounting substrate 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 allows the position of the conductive member M to be correctly aligned with the insulating layer, even if the position of the external electrodes shifts due to compression or firing of the base material.

[0087] -External electrode- In this embodiment, the laminated coil does not use conductor wiring to directly connect the second lead conductor 42 and the third lead conductor 43, but rather 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.

[0088] In the electrode wiring H2, the width dimension L4 perpendicular to the direction in which the second external electrode 32 is directed toward the third external electrode 33 is preferably about 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 electrode wiring H2 that directly connects the second external electrode 32 and the third external electrode 33, as in the laminated coil of the second embodiment, it is possible to prevent the coils provided in the element 10 from short-circuiting due to the generation of an unexpected voltage in the laminated coil, thereby reducing the phenomenon of a decrease in the insulation resistance between the coils. Therefore, it is possible to reduce the deterioration of the electrical characteristics of the inductor.

[0090] <Third embodiment of a laminated coil> Next, the laminated coil of the third embodiment will be described with reference to Figures 10 and 11. Figure 10 is a schematic perspective view (top view) showing an example of the internal structure of the laminated coil of the third embodiment, and Figure 11 is an exploded perspective view of a part of the internal structure of the laminated coil of the third embodiment. The laminated coil of the third embodiment differs from the laminated coil of the above-described embodiment 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 laminated coil described in the above-described embodiment.

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

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

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

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

[0095] The laminated coil of this embodiment includes a conductor wiring H1 that directly connects the second lead conductor 42 and the third lead conductor 43, and an 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 the likelihood of the coils provided in the element 10 short-circuiting due to the generation of an unexpected voltage in the laminated coil and the resulting deterioration of the inductor's electrical characteristics can be reduced.

[0096] In a preferred embodiment of this design, the width dimension of the conductor wiring H1 connecting the second lead conductor 42 and the third lead conductor 43 may be narrower than the width dimension 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 may be smaller than the planar area of ​​the electrode wiring H2. By making the width dimension (or planar area) of the conductor wiring H1 relatively small, the reduction in the volume of magnetic particles in the magnetic layer S in a planar view can be reduced. Therefore, the influence on the inductance value can be reduced.

[0097] <Explanation of stacked coil arrays> Next, the stacked coil array of this disclosure will be described with reference to Figures 12A to C. Figures 12A, 12B, and 12C are schematic perspective views showing an example of the internal structure of the stacked coil array of this disclosure.

[0098] The stacked coil array 100 of this 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 described 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 further from the bottom surface of the base body 10 than the first coil in the stacking direction, and the fourth coil is provided at a position further from the bottom surface of the base body 10 than the third coil in the stacking direction. Furthermore, 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 stacked coil array 100 of this disclosure may include a fifth external electrode 35 and a sixth external electrode 36 electrically connected to 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. 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 this 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 positioned further from the bottom surface of the element 10 than the third coil in the stacking direction. 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. The other end of the fourth coil conductor layer may be connected to the eighth external electrode 38 by an eighth lead conductor 48.

[0101] Herein, a characteristic configuration of the stacked coil array 100 of this disclosure is that 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 stacked coil array shown in Figure 12, the second external electrode 32 and the third external electrode 33 are directly connected by a conductor wiring H1, and the sixth external electrode 36 and the seventh external electrode 37 are directly connected by a conductor wiring H1. Therefore, it is possible to prevent short circuits between the first coil 21 and the second coil 22 and / or between the third coil and the fourth coil.

[0102] In the stacked coil array 100 shown in Figure 12B as an example, 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 short circuits in the vicinity where the first coil 21 and the second coil 22 are closest, it is also possible to prevent short circuits between the first coil and the third coil (or fourth coil), and between the second coil and the third coil (or fourth coil).

[0103] In the stacked coil array 100 shown in Figure 12C as an example, the third lead conductor 43 and the sixth lead conductor 46 are directly connected. In the illustrated example, the third lead conductor 43 and the sixth lead conductor 46 are directly connected by conductor wiring H1. Even with this configuration, in addition to preventing short circuits between the first coil 21 and the second coil 22, it is also possible to prevent short circuits between the first coil and the third coil (or fourth coil), and between the second coil and the third coil (or fourth coil).

[0104] The stacked coil array 100 shown in Figures 12A-C illustrates a configuration in which six coils are provided inside a base body. However, the example is not limited to this; a stacked coil array 100 may also be provided with four coils inside a single base body, or with four or more coils inside a single base body. By providing a stacked coil array 100 with multiple coils inside a base body in this way, it is possible to use it for high-current applications and reduce the mounting area and / or mounting cost by using an array.

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

[0106] The embodiments of the stacked coil and stacked coil array of this disclosure are as follows: <1> A base body with stacked magnetic layers, A first coil is provided inside the aforementioned body and includes a plurality of first coil conductor layers in the stacking direction, and a second coil includes 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, The device comprises a third external electrode and a fourth external electrode electrically connected to the second coil, The first to fourth external electrodes are arranged on the bottom surface of the body. The second coil is provided at a position further from the bottom surface of the base body than the first coil in the stacking direction. A first lead conductor is provided inside the body and connects the end of the first coil conductor layer closest to the bottom surface with the first external electrode, A second lead conductor is provided inside the aforementioned body and connects the other end of the first coil to the second external electrode, A third lead conductor is provided inside the main body and connects the end of the second coil conductor layer closest to the bottom surface with the third external electrode, The body comprises a fourth lead conductor provided inside the main body, which connects the other end of the second coil to the fourth external electrode, The second external electrode and the third external electrode are electrically connected. Stacked coil. <2> The second lead conductor and the third lead conductor are directly connected by a conductor wiring. <1> The laminated coil described above. <3> The second external electrode and the third external electrode are directly connected by electrode wiring. <1> or <2> The laminated coil described above. <4> A conductor wiring that directly connects the second lead conductor and the third lead conductor, The device comprises electrode wiring that directly connects the second external electrode and the third external electrode, <1> The laminated coil described above. <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. <1> ~ <4> A laminated coil as described in one of the following: <6> A base body with stacked magnetic layers, A first coil is provided inside the aforementioned body, comprising a plurality of first coil conductor layers in the stacking direction, a second coil comprising a plurality of second coil conductor layers in the stacking direction, a third coil comprising a plurality of third coil conductor layers in the stacking direction, and a fourth coil comprising 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, The third and fourth external electrodes are electrically connected to the second coil, The third coil is electrically connected to a fifth external electrode and a sixth external electrode, The fourth coil is electrically connected to a seventh external electrode and an eighth external electrode, The first to eighth external electrodes are arranged on the bottom surface of the body. The second coil is provided at a position further from the bottom surface of the base body than the first coil in the stacking direction. The fourth coil is provided at a position further from the bottom surface of the base body than the third coil in the stacking direction. A first lead conductor is provided inside the body and connects the end of the first coil conductor layer closest to the bottom surface with the first external electrode, A second lead conductor is provided inside the aforementioned body and connects the other end of the first coil to the second external electrode, A third lead conductor is provided inside the main body and connects the end of the second coil conductor layer closest to the bottom surface with the third external electrode, The body comprises a fourth lead conductor provided inside the main body, which connects the other end of the second coil to the fourth external electrode, A fifth lead conductor is provided inside the body and connects the end of the third coil conductor layer closest to the bottom surface with the fifth external electrode, A sixth lead conductor is provided inside the aforementioned body and connects the other end of the third coil to the sixth external electrode, A seventh lead conductor is provided inside the body and connects the end of the fourth coil conductor layer closest to the bottom surface with the seventh external electrode, The body comprises an eighth lead conductor provided inside the main body, which connects the other end of the fourth coil to the eighth external electrode, The second external electrode and the third external electrode are electrically connected, The sixth external electrode and the seventh external electrode are electrically connected. Stacked coil array. <7> The third external electrode and the sixth external electrode are directly connected. <6> A stacked coil array as described above. <8> The third lead conductor is directly connected to the third lead conductor. <6> or <7> A stacked coil array as described above. [Industrial applicability]

[0107] The stacked coils and stacked coil arrays of this disclosure can be suitably used as electronic components that can reduce the degradation of electrical characteristics. [Explanation of Symbols]

[0108] 1. Laminated coil 10 Base Body 11. First Main Surface 12 Second Main Surface 13 First end surface 14 Second end face 15 First aspect 16 Second aspect 21. First coil 22 Second Coil 31 1st external electrode 32 2nd external electrode 33 Third external electrode 34 4th external electrode 35 5th external electrode 36 6th external electrode 37 7th external electrode 38 8th external electrode 41 First Lead Conductor 42 Second Lead Conductor 43 Third Lead Conductor 44 Fourth Drawer 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 part 65 Straight section 70 Insulating layer 100-layer coil array G1-G11 Magnetic Layer Group H1 Conductor Wiring H2 electrode wiring L1~L4 Width dimensions M conductive material S magnetic layer

Claims

1. A base body with stacked magnetic layers, A first coil is provided inside the aforementioned body, and includes a plurality of first coil conductor layers in the stacking direction, and a second coil includes 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, The device comprises a third external electrode and a fourth external electrode electrically connected to the second coil, The first to fourth external electrodes are arranged on the bottom surface of the base body. The second coil is provided at a position further from the bottom surface of the base body than the first coil in the stacking direction. A first lead conductor is provided inside the main body and connects the end of the first coil conductor layer closest to the bottom surface with the first external electrode, A second lead conductor is provided inside the aforementioned body and connects the other end of the first coil to the second external electrode, A third lead conductor is provided inside the main body and connects the end of the second coil conductor layer closest to the bottom surface with the third external electrode, The body comprises a fourth lead conductor provided inside the main body, which connects the other end of the second coil to the fourth external electrode, The second external electrode and the third external electrode are electrically connected. Stacked coil.

2. The second lead conductor and the third lead conductor are directly connected by a conductor wiring. The laminated coil according to claim 1.

3. The second external electrode and the third external electrode are directly connected by electrode wiring. The laminated coil according to claim 1.

4. A conductor wiring that directly connects the second lead conductor and the third lead conductor, The device comprises electrode wiring that directly connects the second external electrode and the third external electrode, The laminated 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 laminated coil according to claim 4.

6. A base body with stacked magnetic layers, A first coil is provided inside the aforementioned body, comprising a plurality of first coil conductor layers in the stacking direction, a second coil comprising a plurality of second coil conductor layers in the stacking direction, a third coil comprising a plurality of third coil conductor layers in the stacking direction, and a fourth coil comprising 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, The third and fourth external electrodes are electrically connected to the second coil, The third coil is electrically connected to a fifth external electrode and a sixth external electrode, The fourth coil is electrically connected to a seventh external electrode and an eighth external electrode, The first to eighth external electrodes are arranged on the bottom surface of the base body. The second coil is provided at a position further from the bottom surface of the base body than the first coil in the stacking direction. The fourth coil is provided at a position further from the bottom surface of the base body than the third coil in the stacking direction. A first lead conductor is provided inside the main body and connects the end of the first coil conductor layer closest to the bottom surface with the first external electrode, A second lead conductor is provided inside the aforementioned body and connects the other end of the first coil to the second external electrode, A third lead conductor is provided inside the main body and connects the end of the second coil conductor layer closest to the bottom surface with the third external electrode, The body comprises a fourth lead conductor provided inside the main body, which connects the other end of the second coil to the fourth external electrode, A fifth lead conductor is provided inside the main body and connects the end of the third coil conductor layer closest to the bottom surface with the fifth external electrode, A sixth lead conductor is provided inside the aforementioned body and connects the other end of the third coil to the sixth external electrode, A seventh lead conductor is provided inside the body and connects the end of the fourth coil conductor layer closest to the bottom surface with the seventh external electrode, The body comprises an eighth lead conductor provided inside the main body, which connects the other end of the fourth coil to the eighth external electrode, The second external electrode and the third external electrode are electrically connected, A stacked coil array in which the sixth external electrode and the seventh external electrode are electrically connected.

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

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

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