Multilayer coil component

Abstract

To provide a laminated coil component that can be reduced in electric resistivity.SOLUTION: A laminated coil component 1 comprises: an element body 2 which is formed by laminating a magnetic body layer including a plurality of metal magnetic particles of soft magnetic material; a first coil 8 which is arranged in the element body 2 and also constituted including a plurality of first coil conductors; a second coil 9 which is arranged in the element body 2 and also constituted including a plurality of second coil conductors; a first external electrode 4 to which respective one-end parts of the first coil 8 and second coil 9 are connected; and a second external electrode 5 to which respective other-end parts of the first coil 8 and second coil 9 are connected.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a multilayer coil component.

Background Art

[0002] Patent Document 1 discloses a multilayer coil component including a component body (element body), and one coil disposed in the component body and composed of a plurality of conductor portions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present invention aims to provide a multilayer coil component capable of reducing electrical resistivity.

Means for Solving the Problems

[0005] The multilayer coil component according to one aspect of the present invention includes an element body formed by laminating magnetic layers each containing a plurality of metal magnetic particles of a soft magnetic material, a first coil disposed in the element body and composed of a plurality of first coil conductors, a second coil disposed in the element body and composed of a plurality of second coil conductors, a first external electrode to which one end of each of the first coil and the second coil is connected, and a second external electrode to which the other end of each of the first coil and the second coil is connected.

[0006] In the multilayer coil component according to one aspect of the present invention, a first coil and a second coil are disposed in the element body. One end of each of the first coil and the second coil is connected to a first external electrode, and the other end of each of the first coil and the second coil is connected to a second external electrode. Thus, the multilayer coil component has a configuration in which the first coil and the second coil are connected in parallel. Therefore, in the multilayer coil component, compared with a configuration in which one coil is disposed in the element body, at least two current paths can be secured, so that the electrical resistivity of the DC resistance can be reduced. As a result, in the multilayer coil component, the Q (Quality factor) value can be increased, and thus the characteristics can be improved. Further, in the multilayer coil component, since the loss due to heat generation can be reduced, the quality can be improved.

[0007] In the multilayer coil component, the element body is formed by laminating magnetic body layers each containing a plurality of metal magnetic particles of a soft magnetic material. Thus, in the multilayer coil component, the DC superposition characteristics can be improved compared with an element body formed of a ferrite material.

[0008] In one embodiment, the first coil and the second coil are spaced apart in the lamination direction of the magnetic body layers in the element body, and at least in the region where the first coil and the second coil overlap when viewed from the lamination direction between the first coil and the second coil in the element body, the electrical resistivity may be higher than that of the magnetic body layer. In this configuration, the electrical resistivity between the layers of the first coil and the second coil can be made higher than that of the element material. Thereby, the withstand voltage of the multilayer coil component can be improved.

[0009] In one embodiment, a high-resistance portion having a width dimension equal to or greater than the width dimensions of the first coil conductor and the second coil conductor and having an electrical resistivity higher than that of the magnetic body layer may be disposed in the region where the first coil and the second coil overlap when viewed from the lamination direction. In this configuration, the high-resistance portion can make the electrical resistivity between the layers of the first coil and the second coil higher than that of the element material. Thereby, the withstand voltage of the multilayer coil component can be improved.

[0010] In one embodiment, in the base body, a high-resistance layer having a higher electrical resistivity than the magnetic layer may be provided between the first coil and the second coil. In this configuration, the high-resistance layer can increase the electrical resistivity between the first coil and the second coil compared to the base body material. Thereby, the withstand voltage of the multilayer coil component can be improved.

[0011] In one embodiment, the conductor in the first coil closest to the second coil and the conductor in the second coil closest to the first coil may not overlap when viewed from the stacking direction of the magnetic layers. In this configuration, the withstand voltage of the multilayer coil component can be improved.

[0012] In one embodiment, the first coil has a first connection conductor connected to the first external electrode and a second connection conductor connected to the second external electrode, and the second coil has a third connection conductor connected to the first external electrode and a fourth connection conductor connected to the second external electrode. In the stacking direction of the magnetic layers, the distance between the second connection conductor and the fourth connection conductor is shorter than the distance between the first connection conductor and the third connection conductor, and when viewed from the stacking direction, the winding directions of the first coil and the second coil are the same. In this configuration, by making the distance between the second connection conductor and the fourth connection conductor shorter than the distance between the first connection conductor and the third connection conductor in the stacking direction of the magnetic layers, the potential difference between the first coil and the second coil when current flows through the first coil and the second coil can be reduced. Therefore, the withstand voltage of the multilayer coil component can be improved. Also, since the winding directions of the first coil and the second coil are the same when viewed from the stacking direction, the directions of the magnetic fluxes are the same. Thereby, the inductance values of the first coil and the second coil can be made equivalent.

[0013] In one embodiment, the first coil has a first connection conductor connected to the first external electrode and a second connection conductor connected to the second external electrode, and the second coil has a third connection conductor connected to the first external electrode and a fourth connection conductor connected to the second external electrode. In the stacking direction of the magnetic body layer, the distance between the second connection conductor and the fourth connection conductor is shorter than the distance between the first connection conductor and the third connection conductor. When viewed from the stacking direction, the winding direction of the first coil may be opposite to the winding direction of the second coil. In this configuration, by making the distance between the second connection conductor and the fourth connection conductor shorter than the distance between the first connection conductor and the third connection conductor in the stacking direction of the magnetic body layer, the potential difference can be reduced. Therefore, the withstand voltage of the stacked coil component can be improved. Further, when viewed from the stacking direction, since the winding direction of the first coil is opposite to the winding direction of the second coil, the magnetic flux generated by the first coil and the magnetic flux generated by the second coil cancel each other out. Therefore, magnetic saturation can be suppressed, and the DC superposition characteristics can be improved.

[0014] In one embodiment, the number of first coil conductors of the first coil and the number of second coil conductors of the second coil may be the same. In this configuration, the magnetic flux generated by the first coil and the magnetic flux generated by the second coil can be effectively canceled out. Therefore, magnetic saturation can be more effectively suppressed, and the DC superposition characteristics can be improved.

[0015] In one embodiment, between the first coil and the second coil, two or more metal magnetic particles may be arranged along the stacking direction of the magnetic body layer. In this configuration, the withstand voltage between the layers of the first coil and the second coil can be improved.

Advantages of the Invention

[0016] According to one aspect of the present invention, a reduction in electrical resistivity can be achieved.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

[0018] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0019] [First Embodiment] As shown in FIG. 1, the multilayer coil component 1 according to the first embodiment includes a base body 2, and a first external electrode 4 and a second external electrode 5 respectively disposed at both ends of the base body 2.

[0020] The base body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a shape of a rectangular parallelepiped with chamfered corner portions and ridge line portions, and a shape of a rectangular parallelepiped with rounded corner portions and ridge line portions. As its outer surface, the base body 2 has a pair of end faces 2a and 2b facing each other, a pair of main faces 2c and 2d facing each other, and a pair of side faces 2e and 2f facing each other. The facing direction in which the pair of main faces 2c and 2d face each other is the first direction D1. The facing direction in which the pair of end faces 2a and 2b face each other is the second direction D2. The facing direction in which the pair of side faces 2e and 2f face each other is the third direction D3. In the present embodiment, the first direction D1 is the height direction of the base body 2. The second direction D2 is the longitudinal direction of the base body 2 and is orthogonal to the first direction D1. The third direction D3 is the width direction of the base body 2 and is orthogonal to both the first direction D1 and the second direction D2.

[0021] The pair of end faces 2a and 2b extend in the first direction D1 so as to connect between the pair of main faces 2c and 2d. The pair of end faces 2a and 2b also extend in the third direction D3 (the short side direction of the pair of main faces 2c and 2d). The pair of side faces 2e and 2f extend in the first direction D1 so as to connect between the pair of main faces 2c and 2d. The pair of side faces 2e and 2f also extend in the second direction D2 (the long side direction of the pair of end faces 2a and 2b). The main face 2d can be defined as a mounting surface facing another electronic device (for example, a circuit board or an electronic component) when mounting the laminated coil component 1 on the other electronic device.

[0022] As shown in FIG. 3, the base body 2 is configured by laminating a plurality of magnetic layers 6 and magnetic layers 7. Each of the magnetic layers 6 and magnetic layers 7 is laminated in the first direction D1. That is, the first direction D1 is the lamination direction. The base body 2 has a plurality of magnetic layers 6 and magnetic layers 7 laminated thereon. In the actual base body 2, the plurality of magnetic layers 6 and magnetic layers 7 are integrated to such an extent that the boundaries between the layers are not visible.

[0023] Each of the magnetic layers 6 and 7 contains a plurality of metal magnetic particles. The metal magnetic particles are composed of a soft magnetic alloy (soft magnetic material). The soft magnetic alloy is, for example, an Fe-Si alloy. When the soft magnetic alloy is an Fe-Si alloy, the soft magnetic alloy may contain P. The soft magnetic alloy may be, for example, an Fe-Ni-Si-M alloy. "M" contains one or more elements selected from Co, Cr, Mn, P, Ti, Zr, Hf, Nb, Ta, Mo, Mg, Ca, Sr, Ba, Zn, B, Al, and rare earth elements.

[0024] In the magnetic layers 6 and 7, the metal magnetic particles are bonded to each other. The bonding between the metal magnetic particles is realized, for example, by the bonding between the oxide films formed on the surfaces of the metal magnetic particles. In the magnetic layers 6 and 7, due to the bonding between the oxide films, the metal magnetic particles are electrically insulated from each other. The thickness of the oxide film is, for example, 5 to 60 nm or less. The oxide film may be composed of one or a plurality of layers.

[0025] The magnetic layer 7 contains a material having a higher electrical resistivity than each of the magnetic layers 6. In the present embodiment, the magnetic layer 7 contains, for example, ZrO2. The magnetic layer 7 is disposed between the magnetic layers 6 in the first direction D1. The magnetic layer 7 is disposed between the first coil 8 and the second coil 9. The magnetic layer 7 constitutes a high-resistance layer in the element body 2. Note that a plurality of magnetic layers 7 may be included.

[0026] The element body 2 contains a resin. The resin exists between the plurality of metal magnetic particles. The resin is a resin having electrical insulation properties (insulating resin). The insulating resin includes, for example, silicone resin, phenol resin, acrylic resin, or epoxy resin.

[0027] The average particle diameter of the metal magnetic particles is 0.5 to 15 μm. In the present embodiment, the average particle diameter of the metal magnetic particles is 5 μm. In the present embodiment, the "average particle diameter" means the particle diameter at 50% of the integrated value in the particle size distribution obtained by the laser diffraction / scattering method.

[0028] As shown in FIG. 1, the first external electrode 4 is disposed on the end face 2a side of the element body 2, and the second external electrode 5 is disposed on the end face 2b side of the element body 2. That is, the first external electrode 4 and the second external electrode 5 are spaced apart from each other in the direction in which the pair of end faces 2a and 2b face each other. The first external electrode 4 and the second external electrode 5 contain a conductive material (for example, Ag or Pd, etc.). The first external electrode 4 and the second external electrode 5 are configured as a sintered body of a conductive paste containing conductive metal powder (for example, Ag powder or Pd powder, etc.) and glass frit. The first external electrode 4 and the second external electrode 5 are subjected to electroplating, and a plating layer is formed on their surfaces. For electroplating, for example, Ni, Sn, etc. are used.

[0029] The first external electrode 4 is disposed on one end face 2a side. The first external electrode 4 includes five electrode portions: a first electrode portion 4a located on the end face 2a, a second electrode portion 4b located on the main face 2c, a third electrode portion 4c located on the main face 2d, a fourth electrode portion 4d located on the side face 2e, and a fifth electrode portion 4e located on the side face 2f. The first electrode portion 4a is connected to the second electrode portion 4b, the third electrode portion 4c, the fourth electrode portion 4d, and the fifth electrode portion 4e at the ridge line portion of the element body 2 and is electrically connected to each other. The first external electrode 4 is formed on five surfaces: one end face 2a, a pair of main faces 2c and 2d, and a pair of side faces 2e and 2f. The first electrode portion 4a, the second electrode portion 4b, the third electrode portion 4c, the fourth electrode portion 4d, and the fifth electrode portion 4e are integrally formed.

[0030] In this embodiment, the edges (end faces) of the second electrode portion 4b and the third electrode portion 4c of the first external electrode 4 are along, for example, the third direction D3. The edge of the second electrode portion 4b is linearly formed on the main surface 2c. The edge of the third electrode portion 4c is linearly formed on the main surface 2d. The edges of the fourth electrode portion 4d and the fifth electrode portion 4e of the first external electrode 4 are along the first direction D1. The edge of the fourth electrode portion 4d is linearly formed on the side surface 2e. The edge of the fifth electrode portion 4e is linearly formed on the side surface 2f. Note that the shape of each edge of the second electrode portion 4b, the third electrode portion 4c, the fourth electrode portion 4d, and the fifth electrode portion 4e may be curved or may be formed in a concavo-convex shape.

[0031] The second external electrode 5 is disposed on the other end face 2b side. The second external electrode 5 includes five electrode portions: a first electrode portion 5a located on the end face 2b, a second electrode portion 5b located on the main surface 2c, a third electrode portion 5c located on the main surface 2d, a fourth electrode portion 5d located on the side surface 2e, and a fifth electrode portion 5e located on the side surface 2f. The first electrode portion 5a is connected to the second electrode portion 5b, the third electrode portion 5c, the fourth electrode portion 5d, and the fifth electrode portion 5e at the ridge line portion of the element body 2 and is electrically connected to each other. The second external electrode 5 is formed on five surfaces: one end face 2b, a pair of main surfaces 2c and 2d, and a pair of side surfaces 2e and 2f. The first electrode portion 5a, the second electrode portion 5b, the third electrode portion 5c, the fourth electrode portion 5d, and the fifth electrode portion 5e are integrally formed.

[0032] In this embodiment, the edges of the second electrode portion 5b and the third electrode portion 5c of the second external electrode 5 are along, for example, the third direction D3. The edge of the second electrode portion 5b is linearly formed on the main surface 2c. The edge of the third electrode portion 5c is linearly formed on the main surface 2d. The edges of the fourth electrode portion 5d and the fifth electrode portion 5e of the second external electrode 5 are along the first direction D1. The edge of the fourth electrode portion 5d is linearly formed on the side surface 2e. The edge of the fifth electrode portion 5e is linearly formed on the side surface 2f. Note that the shape of each edge of the second electrode portion 5b, the third electrode portion 5c, the fourth electrode portion 5d, and the fifth electrode portion 5e may be curved or may be formed in an uneven shape.

[0033] As shown in FIG. 2, in the multilayer coil component 1, the first coil 8 and the second coil 9 are arranged in the element body 2. The first coil 8 and the second coil 9 are arranged to be separated from each other in the first direction D1 within the element body 2. In this embodiment, the first coil 8 is arranged on the main surface 2c side of the element body 2. Specifically, the first coil 8 is arranged in a region on the main surface 2c side of the element body 2 rather than at the center of the element body 2 in the first direction D1. The second coil 9 is arranged on the main surface 2d side of the element body 2. Specifically, the second coil 9 is arranged in a region on the main surface 2d side of the element body 2 rather than at the center of the element body 2 in the first direction D1. In the multilayer coil component 1, the first coil 8 and the second coil 9 are electrically connected in parallel.

[0034] As shown in FIG. 3, the first coil 8 is formed in a spiral shape by electrically connecting a plurality of first coil conductors 20, 21, 22, 23, 24, 25, a first connection conductor 26, and a second connection conductor 27. The first coil conductor 20 and the first connection conductor 26 are integrally formed. Adjacent first coil conductors 20, 21, 22, 23, 24, 25 are electrically connected by through-hole conductors (not shown). The first coil conductor 25 and the second connection conductor 27 are electrically connected by through-hole conductors (not shown). The first connection conductor 26 constitutes one end of the first coil 8. The first connection conductor 26 is exposed on the end face 2a of the base body 2 and is connected to the first external electrode 4 (first electrode portion 4a). The second connection conductor 27 constitutes the other end of the first coil 8. The second connection conductor 27 is exposed on the end face 2b of the base body 2 and is connected to the second external electrode 5 (first electrode portion 5a).

[0035] The second coil 9 is formed in a spiral shape by electrically connecting a plurality of second coil conductors 30, 31, 32, 33, 34, 35, a third connection conductor 36, and a fourth connection conductor 37. The second coil conductor 30 and the third connection conductor 36 are integrally formed. Adjacent second coil conductors 30, 31, 32, 33, 34, 35 are electrically connected by through-hole conductors (not shown). The second coil conductor 35 and the fourth connection conductor 37 are electrically connected by through-hole conductors (not shown). The third connection conductor 36 constitutes one end of the second coil 9. The third connection conductor 36 is exposed on the end face 2a of the base body 2 and is connected to the first external electrode 4 (first electrode portion 4a). The fourth connection conductor 37 constitutes the other end of the second coil 9. The fourth connection conductor 37 is exposed on the end face 2b of the base body 2 and is connected to the second external electrode 5 (first electrode portion 5a).

[0036] The first coil conductors 20, 21, 22, 23, 24, 25, the first connection conductor 26, the second connection conductor 27, the second coil conductors 30, 31, 32, 33, 34, 35, the third connection conductor 36 and the fourth connection conductor 37 are made of a conductive material (such as Ni or Cu) commonly used as coil conductors. The first coil conductors 20, 21, 22, 23, 24, 25, the first connection conductor 26, the second connection conductor 27, the second coil conductors 30, 31, 32, 33, 34, 35, the third connection conductor 36 and the fourth connection conductor 37 are configured as sintered bodies of a conductive paste containing the above conductive material.

[0037] As shown in FIG. 2, in the multilayer coil component 1, in the region where at least the first coil 8 and the second coil 9 overlap when viewed from the first direction D1 between the first coil 8 and the second coil 9 of the element body 2, the electrical resistivity is higher than that of the magnetic body layer 6. In the present embodiment, in the element body 2, a magnetic body layer 7 (high-resistance layer) having an electrical resistivity higher than that of the magnetic body layer 6 constituting most of the element body 2 is provided between the first coil 8 and the second coil 9.

[0038] Between the first coil 8 and the second coil 9, two or more metal magnetic particles are arranged along the first direction D1. The metal magnetic particles are arranged side by side along the first direction D1. The fact that the metal magnetic particles are arranged along the first direction D1 means that not only the entire metal magnetic particles overlap each other when viewed from the first direction D1, but also a state where the metal magnetic particles partially overlap each other when viewed from the first direction D1 is included.

[0039] In the multilayer coil component 1, the distance H1 between the first connection conductor 26 of the first coil 8 and the third connection conductor 36 of the second coil 9 is the same as the distance H2 between the second connection conductor 27 of the first coil 8 and the fourth connection conductor 37 of the second coil 9. The winding direction of the first coil 8 and the winding direction of the second coil 9 are the same. Thereby, when a current flows through the multilayer coil component 1, the direction of the magnetic flux generated in the first coil 8 and the direction of the magnetic flux generated in the second coil 9 become the same.

[0040] In the multilayer coil component 1, the conductor in the first coil 8 that is closest to the second coil 9 and the conductor in the second coil 9 that is closest to the first coil 8 do not overlap when viewed from the first direction D1. Specifically, the second connection conductor 27 of the first coil 8 and the second coil conductor 30 and the third connection conductor 36 of the second coil 9 do not overlap when viewed from the first direction D1.

[0041] As described above, in the multilayer coil component 1 according to the present embodiment, the first coil 8 and the second coil 9 are arranged in the base body 2. One end of each of the first coil 8 and the second coil 9 is connected to the first external electrode 4, and the other end of each of the first coil 8 and the second coil 9 is connected to the second external electrode 5. Thereby, the multilayer coil component 1 has a configuration in which the first coil 8 and the second coil 9 are connected in parallel. Therefore, in the multilayer coil component 1, compared with a configuration in which one coil is arranged in the base body 2, at least two current flow paths can be ensured, so that the electrical resistivity of the DC resistance can be reduced. As a result, in the multilayer coil component 1, the Q (Quality factor) value can be increased, so that the characteristics can be improved. Further, in the multilayer coil component 1, since the loss due to heat generation can be reduced, the quality can be improved.

[0042] In the multilayer coil component 1, the base body 2 is formed by laminating a magnetic body layer 6 containing a plurality of metal magnetic particles of a soft magnetic alloy. Thereby, in the multilayer coil component 1, the DC superposition characteristics can be improved compared with a base body formed of a ferrite material.

[0043] In the multilayer coil component 1 according to this embodiment, the first coil 8 and the second coil 9 are arranged separately in the lamination direction of the magnetic body layer 6 in the base body 2. In the region between the first coil 8 and the second coil 9 of the base body 2, at least the region where the first coil 8 and the second coil 9 overlap when viewed from the first direction D1 has a higher electrical resistivity than the magnetic body layer 6. Specifically, in the base body 2, a magnetic body layer 7 (high-resistance layer) having a higher electrical resistivity than the magnetic body layer 6 is provided between the first coil 8 and the second coil 9. In this configuration, the magnetic body layer 7 can make the electrical resistivity between the first coil 8 and the second coil 9 higher than that of the base material. Thereby, the withstand voltage of the multilayer coil component 1 can be improved.

[0044] In the multilayer coil component 1 according to this embodiment, the winding direction of the first coil 8 and the winding direction of the second coil 9 are the same. Thereby, when a current flows through the multilayer coil component 1, the directions of the magnetic fluxes generated in the first coil 8 and the magnetic fluxes generated in the second coil 9 become the same. Therefore, in the multilayer coil component 1, the inductance values of the first coil 8 and the second coil 9 can be made the same.

[0045] In the multilayer coil component 1 according to this embodiment, the conductor in the first coil 8 that is closest to the second coil 9 and the conductor in the second coil 9 that is closest to the first coil 8 do not overlap when viewed from the first direction D1. Specifically, the second connection conductor 27 of the first coil 8 and the second coil conductor 30 and the third connection conductor 36 of the second coil 9 do not overlap when viewed from the first direction D1. In this configuration, the withstand voltage of the multilayer coil component 1 can be improved.

[0046] In the multilayer coil component 1 of this embodiment, two or more metal magnetic particles are arranged along the first direction D1 between the first coil 8 and the second coil 9. In this configuration, the withstand voltage of the multilayer coil component 1 can be improved.

[0047] [Second Embodiment] Next, a second embodiment will be described. As shown in FIG. 4, the multilayer coil component 1A according to the second embodiment includes a base body 2A, and a first external electrode 4 and a second external electrode 5 respectively disposed at both ends of the base body 2A.

[0048] As shown in FIG. 5, the base body 2A is formed by laminating a plurality of magnetic layers 6. Each magnetic layer 6 is laminated in the first direction D1. That is, the first direction D1 is the lamination direction. The base body 2A has a plurality of laminated magnetic layers 6. In the actual base body 2A, the plurality of magnetic layers 6 are integrated to such an extent that the boundaries between the layers are not visible.

[0049] As shown in FIG. 4, in the multilayer coil component 1A, a first coil 8 and a second coil 9 are disposed in the base body 2. The first coil 8 and the second coil 9 are spaced apart from each other in the first direction D1 within the base body 2.

[0050] In the multilayer coil component 1A, a high-resistance portion 40 is disposed in the base body 2. The high-resistance portion 40 is disposed in a region where the first coil 8 and the second coil 9 overlap when viewed from the first direction D1. In this embodiment, the high-resistance portion 40 has a frame shape. The width dimension of the high-resistance portion 40 is equal to or greater than the width dimensions of the first coil conductors 20, 21, 22, 23, 24, 25 and the second coil conductors 30, 31, 32, 33, 34, 35. The high-resistance portion 40 has a higher electrical resistivity than the magnetic layer 6 of the base body 2. The high-resistance portion 40 is formed of, for example, ZrO2. The high-resistance portion 40 is not limited to a frame shape and may be rectangular or the like. When the high-resistance portion 40 is rectangular, when viewed from the first direction D1, the outer edge of the high-resistance portion 40 covers the outer edges of the first coil conductors 20, 21, 22, 23, 24, 25 and the second coil conductors 30, 31, 32, 33, 34, 35.

[0051] As described above, in the multilayer coil component 1A according to this embodiment, the first coil 8 and the second coil 9 are disposed in the base body 2A. Therefore, in the multilayer coil component 1A, it is possible to reduce the electrical resistivity of the DC resistance.

[0052] In the multilayer coil component 1A according to this embodiment, in a region where the first coil 8 and the second coil 9 overlap when viewed from the first direction D1, there is disposed a high-resistance portion 40 having a width dimension equal to or greater than those of the first coil conductors 20, 21, 22, 23, 24, 25 and the second coil conductors 30, 31, 32, 33, 34, 35, and having a higher electrical resistivity than the magnetic body layer 6. With this configuration, the high-resistance portion 40 can increase the electrical resistivity between the first coil 8 and the second coil 9 as compared with the base material. Thereby, the withstand voltage of the multilayer coil component 1A can be improved.

[0053] In the multilayer coil component 1A, a form in which the high-resistance portion 40 is formed of ZrO2 has been described as an example. However, the high-resistance portion 40 may be a void. When the high-resistance portion 40 is a void, a green sheet that becomes the magnetic body layer 6 is formed, and a through-hole is formed at a position where the high-resistance portion 40 (void) in the green sheet is to be formed by laser processing. Subsequently, a resin that disappears when the green chip in which the green sheets are laminated is fired is filled in the through-hole. By firing the green chip, the resin disappears and a void is formed.

[0054] [Third Embodiment] Subsequently, the third embodiment will be described. As shown in FIG. 6, the multilayer coil component 1B according to the third embodiment includes a base body 2B, and a first external electrode 4 and a second external electrode 5 disposed at both ends of the base body 2B, respectively.

[0055] As shown in FIG. 7, the base body 2B is configured by laminating a plurality of magnetic body layers 6. Each magnetic body layer 6 is laminated in the first direction D1. That is, the first direction D1 is the lamination direction. The base body 2B has a plurality of magnetic body layers 6 laminated thereon. In an actual base body 2B, the plurality of magnetic body layers 6 are integrated to such an extent that the boundaries between the layers are not visible.

[0056] As shown in FIG. 6, in the multilayer coil component 1B, a first coil 8 and a second coil 9B are disposed in the base body 2B. The first coil 8 and the second coil 9B are spaced apart in the first direction D1 within the base body 2B. In the present embodiment, the first coil 8 is disposed on the main surface 2c side of the base body 2B. Specifically, the first coil 8 is disposed in a region on the main surface 2c side of the base body 2B with respect to the center of the base body 2B in the first direction D1. The second coil 9B is disposed on the main surface 2d side of the base body 2B. Specifically, the second coil 9B is disposed in a region on the main surface 2d side of the base body 2B with respect to the center of the base body 2B in the first direction D1. In the multilayer coil component 1, the first coil 8 and the second coil 9B are electrically connected in parallel.

[0057] As shown in FIG. 7, the first coil 8 is formed in a spiral shape by electrically connecting a plurality of first coil conductors 20, 21, 22, 23, 24, 25, a first connection conductor 26, and a second connection conductor 27. The first coil conductor 20 and the first connection conductor 26 are integrally formed. The adjacent first coil conductors 20, 21, 22, 23, 24, 25 are electrically connected by through-hole conductors (not shown). The first coil conductor 25 and the second connection conductor 27 are electrically connected by through-hole conductors (not shown). The first connection conductor 26 constitutes one end portion of the first coil 8. The first connection conductor 26 is exposed on the end face 2a of the base body 2 and is connected to the first external electrode 4 (first electrode portion 4a). The second connection conductor 27 constitutes the other end portion of the first coil 8. The second connection conductor 27 is exposed on the end face 2b of the base body 2 and is connected to the second external electrode 5 (first electrode portion 5a).

[0058] The second coil 9B is formed in a spiral shape by electrically connecting a plurality of second coil conductors 50, 51, 52, 53, 54, 55, a third connection conductor 56, and a fourth connection conductor 57. The second coil conductor 55 and the third connection conductor 56 are integrally formed. Adjacent second coil conductors 50, 51, 52, 53, 54, 55 are electrically connected by through-hole conductors (not shown). The second coil conductor 50 and the fourth connection conductor 57 are electrically connected by through-hole conductors (not shown). The third connection conductor 56 constitutes one end portion of the second coil 9B. The third connection conductor 56 is exposed on the end face 2a of the base body 2B and is connected to the first external electrode 4 (first electrode portion 4a). The fourth connection conductor 57 constitutes the other end portion of the second coil 9B. The fourth connection conductor 57 is exposed on the end face 2b of the base body 2B and is connected to the second external electrode 5 (first electrode portion 5a).

[0059] As shown in FIG. 6, in the multilayer coil component 1B, the distance H1 between the first connection conductor 26 of the first coil 8 and the third connection conductor 56 of the second coil 9B is longer than the distance H2 between the second connection conductor 27 of the first coil 8 and the fourth connection conductor 57 of the second coil 9B. In other words, the distance H2 between the second connection conductor 27 of the first coil 8 and the fourth connection conductor 57 of the second coil 9B is shorter than the distance H1 between the first connection conductor 26 of the first coil 8 and the third connection conductor 56 of the second coil 9B. The winding direction of the first coil 8 and the winding direction of the second coil 9B are the same. Thereby, when a current flows through the multilayer coil component 1, the direction of the magnetic flux generated in the first coil 8 and the direction of the magnetic flux generated in the second coil 9 become the same.

[0060] As described above, in the multilayer coil component 1B according to the present embodiment, the first coil 8 and the second coil 9B are arranged in the base body 2B. Therefore, in the multilayer coil component 1B, it is possible to reduce the electrical resistivity of the DC resistance.

[0061] In the multilayer coil component 1B according to this embodiment, in the first direction D1, the distance H2 between the second connection conductor 27 of the first coil 8 and the fourth connection conductor 57 of the second coil 9B is shorter than the distance H1 between the first connection conductor 26 of the first coil 8 and the third connection conductor 56 of the second coil 9B. With this configuration, by making the distance H2 between the second connection conductor 27 of the first coil 8 and the fourth connection conductor 57 of the second coil 9B shorter than the distance H1 between the first connection conductor 26 of the first coil 8 and the third connection conductor 56 of the second coil 9B, the potential difference between the first coil 8 and the second coil 9B when current flows through the first coil 8 and the second coil 9B can be reduced. Therefore, the breakdown voltage of the multilayer coil component 1B can be improved.

[0062] In the multilayer coil component 1B according to this embodiment, when viewed from the first direction D1, the winding direction of the first coil 8 and the winding direction of the second coil 9B are the same. With this configuration, the directions of the magnetic fluxes of the first coil 8 and the second coil 9B become the same. As a result, the inductance values of the first coil 8 and the second coil 9B can be made equal.

[0063] In the multilayer coil component 1B, the base body 2B may have a magnetic body layer 7 (high-resistance layer) like the multilayer coil component 1, or a high-resistance portion 40 may be arranged in the base body 2B like the multilayer coil component 1A.

[0064] [Fourth Embodiment] Subsequently, the fourth embodiment will be described. As shown in FIG. 8, the multilayer coil component 1C according to the fourth embodiment includes a base body 2C, and a first external electrode 4 and a second external electrode 5 respectively arranged at both ends of the base body 2C.

[0065] As shown in FIG. 9, the base body 2C is configured by laminating a plurality of magnetic body layers 6. Each magnetic body layer 6 is laminated in the first direction D1. That is, the first direction D1 is the lamination direction. The base body 2C has a plurality of laminated magnetic body layers 6. In an actual base body 2C, the plurality of magnetic body layers 6 are integrated to such an extent that the boundaries between the layers are not visible.

[0066] As shown in FIG. 8, in the multilayer coil component 1C, a first coil 8C and a second coil 9C are arranged in the base body 2C. The first coil 8C and the second coil 9C are arranged to be separated from each other in the first direction D1 within the base body 2C. In the present embodiment, the first coil 8 is arranged on the main surface 2c side of the base body 2C. Specifically, the first coil 8C is arranged in a region on the main surface 2c side of the base body 2C rather than at the center of the base body 2C in the first direction D1. The second coil 9B is arranged on the main surface 2d side of the base body 2C. Specifically, the second coil 9B is arranged in a region on the main surface 2d side of the base body 2C rather than at the center of the base body 2C in the first direction D1. In the multilayer coil component 1C, the first coil 8C and the second coil 9C are electrically connected in parallel.

[0067] As shown in FIG. 9, the first coil 8C is configured by electrically connecting a plurality of first coil conductors 60, 61, 62, 63, 64, 65, a first connection conductor 66, and a second connection conductor 67. The first coil conductor 60 and the first connection conductor 66 are integrally formed. Adjacent first coil conductors 60, 61, 62, 63, 64, 65 are electrically connected by through-hole conductors (not shown). The first coil conductor 65 and the second connection conductor 67 are electrically connected by through-hole conductors (not shown). The first connection conductor 66 constitutes one end portion of the first coil 8C. The first connection conductor 66 is exposed on the end face 2a of the base body 2C and is connected to the first external electrode 4 (first electrode portion 4a). The second connection conductor 67 constitutes the other end portion of the first coil 8C. The second connection conductor 67 is exposed on the end face 2b of the base body 2C and is connected to the second external electrode 5 (first electrode portion 5a).

[0068] The second coil 9C is configured by electrically connecting a plurality of second coil conductors 70, 71, 72, 73, 74, 75, a third connection conductor 76, and a fourth connection conductor 77. The second coil conductor 75 and the third connection conductor 76 are integrally formed. Adjacent second coil conductors 70, 71, 72, 73, 74, 75 are electrically connected by through-hole conductors (not shown). The second coil conductor 70 and the fourth connection conductor 77 are electrically connected by through-hole conductors (not shown). The third connection conductor 76 constitutes one end portion of the second coil 9C. The third connection conductor 76 is exposed on the end face 2a of the base body 2C and is connected to the first external electrode 4 (first electrode portion 4a). The fourth connection conductor 77 constitutes the other end portion of the second coil 9C. The fourth connection conductor 77 is exposed on the end face 2b of the base body 2C and is connected to the second external electrode 5 (first electrode portion 5a).

[0069] As shown in FIG. 8, in the multilayer coil component 1C, the distance H1 between the first connection conductor 66 of the first coil 8C and the third connection conductor 76 of the second coil 9C is longer than the distance H2 between the second connection conductor 67 of the first coil 8C and the fourth connection conductor 77 of the second coil 9C. In other words, the distance H2 between the second connection conductor 67 of the first coil 8C and the fourth connection conductor 77 of the second coil 9C is shorter than the distance H1 between the first connection conductor 66 of the first coil 8C and the third connection conductor 76 of the second coil 9C. The winding direction of the first coil 8C and the winding direction of the second coil 9C are opposite (reverse). Thereby, when an electric current flows through the multilayer coil component 1C, the magnetic flux generated in the first coil 8 and the magnetic flux generated in the second coil 9 cancel each other out (offset each other).

[0070] As described above, in the multilayer coil component 1C according to the present embodiment, the first coil 8C and the second coil 9C are arranged in the base body 2C. Therefore, in the multilayer coil component 1C, it is possible to reduce the electrical resistivity of the DC resistance.

[0071] In the multilayer coil component 1C according to this embodiment, in the first direction D1, the distance H2 between the second connection conductor 67 of the first coil 8C and the fourth connection conductor 77 of the second coil 9B is shorter than the distance H1 between the first connection conductor 66 of the first coil 8C and the third connection conductor 76 of the second coil 9C. With this configuration, by making the distance H2 between the second connection conductor 67 of the first coil 8C and the fourth connection conductor 77 of the second coil 9C shorter than the distance H1 between the first connection conductor 66 of the first coil 8C and the third connection conductor 76 of the second coil 9C, the potential difference between the first coil 8C and the second coil 9C when current flows through the first coil 8C and the second coil 9C can be reduced. Therefore, the withstand voltage of the multilayer coil component 1C can be improved.

[0072] In the multilayer coil component 1C according to this embodiment, when viewed from the first direction D1, the winding direction of the first coil 8C and the winding direction of the second coil 9C are opposite. With this configuration, the magnetic flux generated in the first coil 8C and the magnetic flux generated in the second coil 9C cancel each other out. Therefore, magnetic saturation can be suppressed, and the DC superposition characteristics can be improved.

[0073] In the multilayer coil component 1C according to this embodiment, the number of the plurality of first coil conductors 60, 61, 62, 63, 64, 65 of the first coil 8C is the same as the number of the plurality of second coil conductors 70, 71, 72, 73, 74, 75 of the second coil 9C. With this configuration, the magnetic flux generated in the first coil 8C and the magnetic flux generated in the second coil 9C can be effectively canceled out. Therefore, magnetic saturation can be more effectively suppressed, and the DC superposition characteristics can be improved.

[0074] In the multilayer coil component 1C, the base body 2B may have a magnetic body layer 7 (high-resistance layer) like the multilayer coil component 1, or a high-resistance portion 40 may be arranged on the base body 2B like the multilayer coil component 1A.

[0075] As described above, the embodiments of the present invention have been described. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the gist thereof.

[0076] The number of first coil conductors and the number of second coil conductors are not limited to the values described above. When, like the laminated coil component 1B of the fourth embodiment, the winding directions of the first coil 8C and the second coil 9C are opposite and the directions of magnetic fluxes are different, it is preferable that the number of first coil conductors and the number of second coil conductors are the same.

[0077] In the laminated coil component 1, from the viewpoint of improving the withstand voltage, the distance in the first direction D1 between the first coil 8 and the second coil 9C may be increased. The same applies to the laminated coil components 1A, 1B, and 1C.

[0078] The first external electrode 4 may have only the first electrode portion 4a or may have only the second electrode portion 4b. The second external electrode 5 may also have only the first electrode portion 5a or may have only the second electrode portion 5b. The first external electrode 4 and the second external electrode 5 can adopt various shapes.

Description of Reference Numerals

[0079] 1, 1A, 1B, 1C... laminated coil components; 2, 2A, 2B, 2C... bodies; 4... first external electrode; 5... second external electrode; 6... magnetic body layer; 7... magnetic body layer (high-resistance layer); 8, 8C... first coils; 9, 9B, 9C... second coils; 20, 21, 22, 23, 24, 25, 60, 61, 62, 63, 64, 65... first coil conductors; 26, 66... first connection conductors; 27, 67... second connection conductors; 30, 31, 32, 33, 34, 35, 50, 51, 52, 53, 54, 55, 70, 71, 72, 73, 74, 75... second coil conductors; 36, 56, 76... third connection conductors; 37, 57, 77... fourth connection conductors; 40... high-resistance portion; H1, H2... distances.

Claims

1. A base body formed by laminating magnetic body layers each containing a plurality of metal magnetic particles of a soft magnetic material, A first coil disposed within the base body and composed of a plurality of first coil conductors, A second coil disposed within the base body and composed of a plurality of second coil conductors, A first external electrode to which one end of each of the first coil and the second coil is connected, A second external electrode to which the other end of each of the first coil and the second coil is connected, and The first coil and the second coil are spaced apart from each other in the lamination direction of the magnetic body layers in the base body, In the base body, in a region where at least the first coil and the second coil overlap when viewed from the lamination direction between the first coil and the second coil, the electrical resistivity is higher than that of the magnetic body layer, A laminated coil component in which a high-resistance layer having an electrical resistivity higher than that of the magnetic body layer is provided between the first coil and the second coil in the base body.

2. The laminated coil component according to claim 1, wherein a conductor closest to the second coil in the first coil and a conductor closest to the first coil in the second coil do not overlap when viewed from the lamination direction of the magnetic body layers.

3. The first coil has a first connection conductor connected to the first external electrode and a second connection conductor connected to the second external electrode, The second coil has a third connection conductor connected to the first external electrode and a fourth connection conductor connected to the second external electrode, In the lamination direction of the magnetic body layers, the distance between the second connection conductor and the fourth connection conductor is shorter than the distance between the first connection conductor and the third connection conductor, The laminated coil component according to claim 1 or 2, wherein the winding direction of the first coil is opposite to the winding direction of the second coil when viewed from the lamination direction so that the magnetic flux generated in the first coil and the magnetic flux generated in the second coil cancel each other out.

4. The laminated coil component according to claim 3, wherein the number of the first coil conductors of the first coil is the same as the number of the second coil conductors of the second coil.

5. The laminated coil component according to any one of claims 1 to 4, wherein two or more of the metal magnetic particles are arranged along the lamination direction of the magnetic body layers between the first coil and the second coil.

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