inductor

Abstract

The purpose of the present invention is to provide an inductor that further reduces a short circuit between conductor layers inside an element body and improves insulation. An inductor according to the present disclosure comprises: an element body 10 in which a first coil C1 configured by laminating a plurality of first conductor layers CD1 and a second coil C2 configured by laminating a plurality of second conductor layers CD2 are embedded so as to overlap each other in a lamination direction; and external electrodes 21-24 disposed on a mounting surface of the element body 10. The element body 10 has a first magnetic portion ML1 containing first metal magnetic particles MP1, a second magnetic portion ML2 containing second metal magnetic particles MP2 having an average particle diameter smaller than that of the first metal magnetic particles MP1, a first lead-out conductor TH1 led out from one end of the first coil C1 toward the external electrodes 21-24, a second lead-out conductor TH2 led out from the other end of the first coil C1 located farther from the mounting surface than the one end of the first coil C1 toward the external electrodes 21-24, a third lead-out conductor TH3 led out from one end of the second coil C2 toward the external electrodes 21-24, and a fourth lead-out conductor TH4 led out toward the external electrodes 21-24 from the other end of the second coil C2 positioned farther from the mounting surface than the one end of the second coil C2. The first magnetic portion ML1 is positioned inside at least the winding portions of the first coil C1 and the second coil C2. The second magnetic portion ML2 is positioned between the first conductor layers CD1 in the lamination direction, between the second conductor layers CD2 in the lamination direction, and between the first conductor layers CD1 and the second conductor layers in the lamination direction. The second magnetic portion ML2 positioned between the first conductor layers CD1 extends to a position overlapping the first lead-out conductor TH1 in a plan view viewed from the upper surface side of the element body and extends to be in contact with the second lead-out conductor TH2. The second magnetic portion ML2 positioned between the second conductor layers CD2 extends to a position overlapping the third lead-out conductor TH3 in a plan view viewed from the upper surface side of the element body and extends to be in contact with the fourth lead-out conductor TH4.

Description

Inductor

[0001] The present disclosure relates to an inductor.

[0002] Patent Document 1 discloses a multilayer inductor, which is a surface-mount component including an insulating substrate portion, an internal conductor built in the substrate portion, and an external electrode provided on the mounting surface of the substrate portion and electrically connected to the internal conductor.

[0003] Japanese Patent Application Laid-Open No. 2019-176109

[0004] Although the substrate portion in which the internal conductor described in Patent Document 1 is built has insulation properties, further improvement in insulation characteristics has been demanded. Specifically, it has been necessary to further reduce the possibility that a plurality of internal conductors laminated inside the substrate portion short-circuit.

[0005] In view of such problems, the main object of the present disclosure is to provide an inductor that further reduces the short-circuit between conductor layers inside the body and enhances the insulation property.

[0006] The inductor of the present disclosure comprises a base body in which a first coil, composed of multiple stacked first conductor layers, and a second coil, composed of multiple stacked second conductor layers, are embedded overlapping each other in the stacking direction, and an external electrode disposed on the mounting surface of the base body, wherein the base body comprises a first magnetic portion containing first metallic magnetic particles, a second magnetic portion containing second metallic magnetic particles having a smaller average particle size than the first metallic magnetic particles, a first lead conductor drawn out from one end of the first coil toward the external electrode, a second lead conductor drawn out from the other end of the first coil toward the external electrode, located further from the mounting surface than the one end of the first coil, a third lead conductor drawn out from one end of the second coil toward the external electrode, and a fourth lead conductor drawn out from the other end of the second coil toward the external electrode, wherein the first magnetic portion is located at least inside the winding portions of the first coil and the second coil. The second magnetic portion is located between the first conductor layers in the stacking direction, between the second conductor layers in the stacking direction, and between the first conductor layer and the second conductor layer in the stacking direction. The second magnetic portion located between the first conductor layers extends to a position where it overlaps with the first lead conductor in a plan view from the top side of the substrate, and extends to a position where it contacts the second lead conductor. The second magnetic portion located between the second conductor layers extends to a position where it overlaps with the third lead conductor in a plan view from the top side of the substrate, and extends to a position where it contacts the fourth lead conductor.

[0007] According to the inductor of this disclosure, the element has a second magnetic portion containing second metallic magnetic particles having a smaller average particle size than the first metallic magnetic particles, and the second magnetic portion is located between the first conductor layer and the second conductor layer in the stacking direction. The second magnetic portion located between the first conductor layers extends to a position where it overlaps with the first lead conductor in a plan view and extends to a position where it contacts the second lead conductor, and the second magnetic portion located between the second conductor layers extends to a position where it overlaps with the third lead conductor in a plan view from the top side of the element and extends to a position where it contacts the fourth lead conductor. As a result, short circuits between the first conductor layers, between the second conductor layers, and between the first and second conductor layers can be further reduced, and insulation can be improved.

[0008] Figure 1 is a perspective view of the inductor of the present disclosure. Figure 2 is a schematic exploded plan view of the inductor of the present disclosure. Figure 3 is a schematic plan perspective view of the inductor of the present disclosure. Figure 4A is a schematic cross-sectional view taken along the line IV-IV in Figure 3. Figure 4B is a schematic cross-sectional view of the region shown by the dashed line in Figure 4A. Figure 5A is a schematic cross-sectional view taken along the line Va-Va in Figure 3. Figure 5B is a schematic cross-sectional view taken along the line Vb-Vb in Figure 3.

[0009] The inductors of this disclosure are described below. However, this disclosure is not limited to the configurations described below and may be modified as appropriate without departing from the gist of this disclosure. Furthermore, combinations of several of the preferred configurations described below also constitute this disclosure.

[0010] The inductor of this disclosure can be used, for example, in a DC-DC converter. However, the inductor of this disclosure is also applicable to applications other than DC-DC converters.

[0011] In this specification, terms indicating relationships between elements (e.g., "parallel," "orthogonal," etc.) and terms indicating 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 base body are stacked is defined as the "stacking direction." Also, in this specification, "plan view" refers to viewing the base body 10 from the second main surface 12 side (see Figure 1).

[0012] The drawings shown below are schematic representations, and their dimensions, aspect ratios, and scales may differ from those of the actual product.

[0013] <Description of the Inductor in This Disclosure> The inductor in this disclosure will be described with reference to Figures 1 to 5. Note that the shape and arrangement of the inductor and its components are not limited to the examples shown. The inductor 1 in this disclosure comprises a base body 10 and external electrodes 21 to 24 provided on the mounting surface of the base body 10. Each component will be described in detail below under separate sections.

[0014] -Basic Body- The basic body 10 is, for example, a hexahedron shape having six faces. As an example, it may be a rectangular prism shape or a roughly rectangular prism shape. The vertices and edges of the basic body 10 may be rounded. The vertices are the parts where three faces of the basic body 10 intersect, and the edges are the parts where two faces of the basic body 10 intersect.

[0015] Figure 1 shows the long side direction, short side direction, and height direction of the inductor 1 and the element 10 as the L direction, W direction, and T direction, respectively. The long side direction L, the short side direction W, and the height direction T are mutually orthogonal.

[0016] The base body 10 shown in Figure 1 has a first main surface 11 and a second main surface 12 facing the height direction T, a first side surface 13 and a second side surface 14 facing the short side direction W, and a first end surface 15 and a second end surface 16 facing the long side direction L. The first main surface 11 of the base body 10, which corresponds to the mounting surface of the inductor 1 (the bottom surface of the base body), has a first external electrode 21, a second external electrode 22, a third external electrode 23, and a fourth external electrode 24 formed thereon.

[0017] Figure 2 is a schematic exploded perspective view showing an example of the internal structure of the inductor 1 of this disclosure. As shown in Figure 2, the base body 10 comprises a magnetic layer (first magnetic portion ML1 and second magnetic portion ML2), a first coil C1, a second coil C2, and first to fourth lead conductors TH1 to TH4. In this embodiment, as shown in Figure 2, the base body 10 is made up of stacked lamination groups G1 to G9, and first to fourth external electrodes 21 to 4 external electrodes 24 are formed on the lower side of lamination group G9. Note that the boundaries of each layer of the lamination structure of the base body 10 may disappear.

[0018] (Laminated group G1) Laminated group G1 may include a first magnetic portion ML1 as a magnetic layer. The first magnetic portion ML1 of laminated group G1 may constitute the second main surface 12 of the base body 10 (see Figure 1). Details of the first magnetic portion ML1 will be described later.

[0019] (Laminated group G2) Laminated group G2 may include a first magnetic portion ML1 as a magnetic layer and a second conductor layer CD2 as a second coil C2.

[0020] The first magnetic portion ML1 is positioned on the inside and outside of the winding portion of the second coil C2.

[0021] The second conductor layer CD2 is wound around the winding axis AX2 in a plan view. Specifically, it is wound along the outer edge of the base body 10 from a position corresponding to the fourth external electrode 24 in a plan view to a position corresponding to the connecting conductor V with the laminated group G3.

[0022] Here, the second conductor layer CD2 of the laminated group G2 is electrically connected to the fourth lead conductor TH4 at a position corresponding to the fourth external electrode 24 in the lamination direction, but is not electrically connected to the first lead conductor TH1 to the third lead conductor TH3. For this reason, a notch A may be provided at a position where there is no electrical connection to the first lead conductor TH1 to the third lead conductor TH3.

[0023] (Laminated Group G3) Laminated group G3 comprises a first magnetic portion ML1 as a magnetic layer, a second magnetic portion ML2 arranged to overlap with the second conductor layer CD2 of the above-mentioned laminated group G2, a connecting conductor V electrically connected to the second conductor layer CD2 of the above-mentioned laminated group G2, and a fourth lead conductor TH4. In this specification, "overlapping" may include not only overlapping in a manner that is strictly coincidental in a plan view, but also overlapping in a manner that covers and hides the object in a plan view. Details of the second magnetic portion ML2 will be described later.

[0024] The first magnetic portion ML1 is positioned inside and outside the second magnetic portion ML2. In other words, the first magnetic portion ML1 may be located in an inside position corresponding to the winding axis AX2 of the coil, and in an outside position between the outer edge of the second magnetic portion ML2 and the outer edge of the element 10 in a plan view.

[0025] The second magnetic portion ML2 is formed around the entire circumference of the second coil C2, extending to a position where it overlaps with the third lead conductor TH3 in a plan view, and extending to a position where it contacts the fourth lead conductor TH4. Specifically, the second magnetic portion ML2 extends in such a way that it hides the third lead conductor TH3 in a plan view, and is in contact with the fourth lead conductor TH4. The reason for designing the second magnetic portion ML2 in this way will be explained in detail later, but as shown in Figure 5A, it prevents contact between the second conductor layer CD2 of the laminated group G3 and the second conductor layer CD2 of the laminated group G5 that is connected to the third lead conductor TH3. More specifically, as shown in Figure 5A, by positioning the second magnetic portion ML2 at a location (on a straight line L1) where the second conductor layer CD2 of the laminated group G3 and the second conductor layer CD2 of the laminated group G5 are close in the lamination direction, the insulation of the inductor can be improved.

[0026] In a preferred embodiment of the second magnetic portion ML2, the second magnetic portion ML2 may be designed to be wider than the second conductor layer CD2 of the laminated group G2 in a plan view. In other words, when viewing the base body 10 from the bottom, the second magnetic portion ML2 may cover the second conductor layer CD2. Therefore, the second magnetic portion ML2 located between the second conductor layer CD2 of the laminated group G2 and the second conductor layer CD2 of the laminated group G4 can appropriately electrically insulate the second conductor layers CD2 located in the lamination direction from each other.

[0027] More preferably, the second magnetic portion ML2 may have notches A at positions corresponding to three of the first to fourth lead conductors TH1 to TH4 in the stacking direction. In the second magnetic portion ML2 of stacking group G3, notches A may be provided at positions corresponding to the first lead conductor TH1, the second lead conductor TH2, and the fourth lead conductor TH4 in the stacking direction. With notches A provided in this way, the fourth lead conductor TH4 can be placed in the notch A portion of stacking group G3, and the inductor can be miniaturized by utilizing the empty space.

[0028] In a further preferred embodiment of notch A, the notch A at the position where the second magnetic portion ML2 and the fourth leading conductor TH4 are in contact may have a smaller notch size than the other notches A. By designing the notch size in this way, the planar area of ​​the second magnetic portion ML2 at the position in contact with the fourth leading conductor TH4 can be increased, thereby improving the insulation provided by the second magnetic portion ML2.

[0029] The connecting conductor V is a conductor that electrically connects the second conductor layer CD2 of the lamination group G2 and the second conductor layer CD2 of the lamination group G4 in the lamination direction. The connecting conductor V may be arranged on a straight line along the L direction (see Figure 1) connecting the third external electrode 23 and the fourth external electrode 24 in a plan view. Furthermore, the above-mentioned second magnetic portion ML2 may be arranged around the connecting conductor V in a plan view.

[0030] The fourth lead conductor TH4 may be in electrical contact with the fourth external electrode 24, which is arranged in the stacking direction. The fourth lead conductor TH4 may also be formed in a fan shape in a plan view. Furthermore, the curved portion of the fourth lead conductor TH4 may be in contact with the second magnetic portion ML2.

[0031] The above-described embodiment of the laminated group G3 assumes that all layers of the laminated group G3 have the shape shown in Figure 2 in plan view. However, the embodiment is not limited to the above-described embodiment, and the shape of each layer in the laminated group G3 may be different in plan view. For example, there may be multiple second magnetic portions ML2 located between the second conductor layers CD2. Also, the second magnetic portion ML2 located between the second conductor layers CD2, connected to the third lead conductor TH3, and in contact with the second conductor layer CD2 (the second magnetic portion ML2 in contact with the laminated group G4) may extend to a position that overlaps with the third lead conductor TH3 in plan view. Furthermore, the second magnetic portion ML2 located between the second conductor layers CD2, connected to the fourth lead conductor TH4, and in contact with the second conductor layer CD2 (the second magnetic portion ML2 in contact with the laminated group G2) may extend to contact the fourth lead conductor TH4. By altering the planar shape of each layer in this way, the shape of the second magnetic portion ML2 can be changed to obtain more appropriate insulating properties.

[0032] (Laminated group G4) Laminated group G4 may include a first magnetic portion ML1 as a magnetic layer, a second conductor layer CD2 as a second coil C2, and a fourth lead conductor TH4.

[0033] The first magnetic portion ML1 is located on the inside and outside of the winding portion of the second conductor layer CD2.

[0034] The second conductor layer CD2 is wound around the winding axis AX2 in a plan view. Specifically, it is wound along the outer edge of the base body 10 from the position corresponding to the connecting conductor V with the laminated group G3 in a plan view to the position corresponding to the third external electrode 23.

[0035] Here, the second conductor layer CD2 of the laminated group G4 is electrically connected to the third lead conductor TH3 at a position corresponding to the third external electrode 23 in the lamination direction, but is not electrically connected to the first lead conductor TH1, the second lead conductor TH2, and the fourth lead conductor TH4. Therefore, a notch A may be provided at a position where there is no electrical connection to the first lead conductor TH1, the second lead conductor TH2, and the fourth lead conductor TH4. If a notch A is provided in this way, the fourth lead conductor TH4 can be placed in the notch A portion of the laminated group G4, and the inductor can be miniaturized by utilizing the empty space.

[0036] The fourth lead conductor TH4 may be in electrical contact with the fourth external electrode 24, which is arranged in the stacking direction. The fourth lead conductor TH4 may also be formed in a fan shape in a plan view. Furthermore, the periphery of the fourth lead conductor TH4 may be in contact with the first magnetic portion ML1 in a plan view.

[0037] (Laminated group G5) Laminated group G5 comprises a first magnetic portion ML1 as a magnetic layer, a second magnetic portion ML2 arranged to overlap with the second conductor layer CD2 of the above-mentioned laminated group G4, a third lead conductor TH3, and a fourth lead conductor TH4.

[0038] The first magnetic portion ML1 is positioned in the stacking direction, corresponding to the winding axis of the coil. In a plan view, the second magnetic portion ML2 is positioned at the outer edge of the first magnetic portion ML1.

[0039] The second magnetic portion ML2 extends to a position overlapping the first lead conductor TH1 and the second lead conductor TH2 in a plan view, and extends until it contacts the third lead conductor TH3 and until it contacts the fourth lead conductor TH4. When the second magnetic portion ML2 is designed in this way, as shown in FIGS. 5A and 5B, contact between the second conductor layer CD2 of the laminated group G4 and the first conductor layer CD1 of the laminated group G6 can be prevented. More specifically, as shown in FIGS. 5A and 5B, by arranging the second magnetic portion ML2 at a position (on the straight line L3) where the second conductor layer CD2 of the laminated group G4 and the first conductor layer CD1 of the laminated group G6 are close to each other in the lamination direction, the insulation of the inductor can be enhanced.

[0040] Further, the second magnetic portion ML2 of the laminated group G5 may extend to the outer edge of the element body 10. By extending the second magnetic portion ML2 to the outer edge of the element body 10, the insulation of the inductor 1 can be more preferably enhanced.

[0041] The third lead conductor TH3 may be in electrical contact with the third external electrode 23 arranged in the lamination direction. Also, the third lead conductor TH3 may be formed in a fan shape in a plan view. And it may be in contact with the second magnetic portion ML2 around the third lead conductor TH3.

[0042] The fourth lead conductor TH4 may be in electrical contact with the fourth external electrode 24 arranged in the lamination direction. Also, the fourth lead conductor TH4 may be formed in a fan shape in a plan view. And it may be in contact with the second magnetic portion ML2 around the fourth lead conductor TH4.

[0043] (Laminated group G6) The laminated group G6 may include a first magnetic portion ML1 as a magnetic layer, a first conductor layer CD1 as a first coil C1, a third lead conductor TH3, and a fourth lead conductor TH4.

[0044] The first magnetic portion ML1 is arranged inside and outside the winding of the second conductor layer CD2.

[0045] The first conductor layer CD1 is wound around the winding axis AX1 in a plan view. Specifically, it is wound along the outer edge of the element body 10 from the position corresponding to the second external electrode 22 to the position corresponding to the connection conductor V with the lamination group G7 in a plan view.

[0046] Here, the first conductor layer CD1 of the lamination group G6 is electrically connected to the second lead-out conductor TH2 at the position corresponding to the second external electrode 22 in the lamination direction, but is not electrically connected to the first lead-out conductor TH1, the third lead-out conductor TH3, and the fourth lead-out conductor TH4. Therefore, a notch A may be provided at a position where it is not electrically connected to the first lead-out conductor TH1, the third lead-out conductor TH3, and the fourth lead-out conductor TH4. When the notch A is provided in this way, in the lamination group G6, the third lead-out conductor TH3 and the fourth lead-out conductor TH4 can be arranged in the notch A portion, and the miniaturization of the inductor can be achieved by utilizing the vacant space.

[0047] The third lead-out conductor TH3 may be in electrical contact with the third external electrode 23 arranged in the lamination direction. Also, the third lead-out conductor TH3 may be formed in a fan shape in a plan view. And in a plan view, the periphery of the third lead-out conductor TH3 may be in contact with the first magnetic portion ML1.

[0048] The fourth lead-out conductor TH4 may be in electrical contact with the fourth external electrode 24 arranged in the lamination direction. Also, the fourth lead-out conductor TH4 may be formed in a fan shape in a plan view. And in a plan view, the periphery of the fourth lead-out conductor TH4 may be in contact with the first magnetic portion ML1.

[0049] (Lamination group G7) The lamination group G7 includes a first magnetic portion ML1 as a magnetic layer, a second magnetic portion ML2 arranged so as to overlap the second conductor layer CD2 of the above-described lamination group G2, a connection conductor V electrically connected to the second conductor layer CD2 of the lamination group G2, and the fourth lead-out conductor TH4.

[0050] The first magnetic portion ML1 is positioned both inside and outside the winding of the second magnetic portion ML2. In other words, the first magnetic portion ML1 may be located at an inside position corresponding to the winding axis AX1 of the coil, and at an outside position between the outer edge of the second magnetic portion ML2 and the outer edge of the base body 10 in a plan view.

[0051] The second magnetic portion ML2 is formed around the entire circumference of the first coil C1 and extends to a position where it overlaps with the first lead conductor TH1 in a plan view, and also extends to a position where it is in contact with the second lead conductor TH2. With this configuration, as shown in Figure 5B, contact between the first conductor layer CD1 of the laminated group G6 and the first conductor layer CD1 connected to the second lead conductor TH2 of the laminated group G8 can be prevented. More specifically, as shown in Figure 5B, the insulation of the inductor can be improved by arranging the second magnetic portion at a position where the first conductor layer CD1 of the laminated group G6 and the first conductor layer CD1 of the laminated group G8 are close in the lamination direction.

[0052] In a preferred embodiment of the second magnetic portion ML2, the second magnetic portion ML2 may be designed to be wider than the first conductor layer CD1 of the lamination group G6 in a plan view. In other words, when viewing the base body 10 from the bottom, the second magnetic portion ML2 may cover the first conductor layer CD1. Therefore, the second magnetic portion ML2, located between the first conductor layer CD1 of lamination group G6 and the first conductor layer CD1 of lamination group G8, can appropriately electrically insulate the first conductor layers CD1 located in the lamination direction from each other.

[0053] More preferably, the second magnetic portion ML2 may have notches A at positions corresponding to three of the first to fourth lead conductors TH1 to TH4 in the stacking direction. In the second magnetic portion ML2 of stacking group G7, notches A may be provided at positions corresponding to the second lead conductor TH2, the third lead conductor TH3, and the fourth lead conductor TH4 in the stacking direction. With notches A provided in this way, the second lead conductor TH2 can be placed in the notch A portion of stacking group G7, and the inductor can be miniaturized by utilizing the empty space.

[0054] In a further preferred embodiment of notch A, the notch A at the position where the second magnetic portion ML2 and the second lead conductor TH2 are in contact may have a smaller notch size than the other notches A. By designing the notch size in this way, the planar area of ​​the second magnetic portion ML2 at the position in contact with the second lead conductor TH2 can be increased, thereby improving the insulation provided by the second magnetic portion ML2.

[0055] The connecting conductor V is a conductor that electrically connects the first conductor layer CD1 of the lamination group G6 and the first conductor layer CD1 of the lamination group G8 in the lamination direction. The connecting conductor V may be arranged on a straight line along the L direction (see Figure 1) connecting the first external electrode 21 and the second external electrode 22 in a plan view. Furthermore, the second magnetic portion ML2 described above may be arranged around the connecting conductor V in a plan view.

[0056] The second lead conductor TH2 may be in electrical contact with the second external electrode 22, which is arranged in the stacking direction. The second lead conductor TH2 may also be formed in a fan shape in plan view. Furthermore, the curved portion of the second lead conductor TH2 may be in contact with the second magnetic portion ML2.

[0057] The third lead conductor TH3 may be in electrical contact with the third external electrode 23, which is arranged in the stacking direction. The third lead conductor TH3 may also be formed in a fan shape in a plan view. Furthermore, the periphery of the third lead conductor TH3 may be in contact with the first magnetic portion ML1.

[0058] The fourth lead conductor TH4 may be in electrical contact with the fourth external electrode 24, which is arranged in the stacking direction. The fourth lead conductor TH4 may also be formed in a fan shape in a plan view. Furthermore, the periphery of the fourth lead conductor TH4 may be in contact with the first magnetic portion ML1.

[0059] The above-described embodiment of the laminated group G7 is intended to have all layers of the laminated group G7 having the shape shown in Figure 2 in plan view. However, the embodiment is not limited to the above-described embodiment, and the shape of each layer in the laminated group G7 may be different in plan view. For example, there may be multiple second magnetic portions ML2 located between the first conductor layers CD1. Also, the second magnetic portion ML2 located between the first conductor layers CD1, connected to the first lead conductor TH1, and in contact with the first conductor layer CD1 (the second magnetic portion ML2 in contact with the laminated group G8) may extend to a position that overlaps with the first lead conductor TH1 in plan view. Furthermore, the second magnetic portion ML2 located between the first conductor layers CD1, connected to the second lead conductor TH2, and in contact with the first conductor layer CD1 (the second magnetic portion ML2 in contact with the laminated group G6) may extend until it is in contact with the second lead conductor TH2. By altering the planar shape of each layer in this way, the shape of the second magnetic portion ML2 can be changed to obtain more appropriate insulating properties.

[0060] (Laminated group G8) Laminated group G8 may include a first magnetic portion ML1 as a magnetic layer, a first conductor layer CD1 as a first coil C1, a second lead conductor TH2, a third lead conductor TH3, and a fourth lead conductor TH4.

[0061] The first magnetic portion ML1 is located on the inside and outside of the winding of the second conductor layer CD2.

[0062] The first conductor layer CD1 is wound around the winding axis AX1 in a plan view. Specifically, it is wound along the outer edge of the base body 10 from the position corresponding to the connecting conductor V with the laminated group G7 in a plan view to the position corresponding to the second external electrode 22.

[0063] The first conductor layer CD1 of the laminated group G8 is electrically connected to the first lead conductor TH1 at a position corresponding to the first external electrode 21 in the lamination direction, but is not electrically connected to the second lead conductor TH2, the third lead conductor TH3, and the fourth lead conductor TH4. Therefore, a notch A may be provided at a position where there is no electrical connection to the second lead conductor TH2, the third lead conductor TH3, and the fourth lead conductor TH4. If a notch A is provided in this way, the second lead conductor TH2, the third lead conductor TH3, and the fourth lead conductor TH4 can be placed in the notch A portion of the laminated group G8, and the inductor can be miniaturized by utilizing the empty space.

[0064] The second lead conductor TH2 may be in electrical contact with the second external electrode 22, which is arranged in the stacking direction. The second lead conductor TH2 may also be formed in a fan shape in plan view. Furthermore, the periphery of the second lead conductor TH2 may be in contact with the first magnetic portion ML1 in plan view.

[0065] The third lead conductor TH3 may be in electrical contact with the third external electrode 23, which is arranged in the stacking direction. The third lead conductor TH3 may also be formed in a fan shape in plan view. Furthermore, the periphery of the third lead conductor TH3 may be in contact with the first magnetic portion ML1 in plan view.

[0066] The fourth lead conductor TH4 may be in electrical contact with the fourth external electrode 24, which is arranged in the stacking direction. The fourth lead conductor TH4 may also be formed in a fan shape in a plan view. Furthermore, the periphery of the fourth lead conductor TH4 may be in contact with the first magnetic portion ML1 in a plan view.

[0067] (Laminated group G9) Laminated group G9 may include a first magnetic portion ML1 as a magnetic layer, a first lead conductor TH1, a second lead conductor TH2, a third lead conductor TH3, and a fourth lead conductor TH4.

[0068] The first magnetic portion ML1 is located on the inside and outside of the winding of the second conductor layer CD2.

[0069] The first lead conductor TH1 may be in electrical contact with the first external electrode 21, which is arranged in the stacking direction. The first lead conductor TH1 may also be formed in a fan shape in plan view. Furthermore, the periphery of the first lead conductor TH1 may be in contact with the first magnetic portion ML1 in plan view.

[0070] The second lead conductor TH2 may be in electrical contact with the second external electrode 22, which is arranged in the stacking direction. The second lead conductor TH2 may also be formed in a fan shape in plan view. Furthermore, the periphery of the second lead conductor TH2 may be in contact with the first magnetic portion ML1 in plan view.

[0071] The third lead conductor TH3 may be in electrical contact with the third external electrode 23, which is arranged in the stacking direction. The second lead conductor TH2 may be formed in a fan shape in a plan view. In a plan view, the periphery of the second lead conductor TH2 may be in contact with the first magnetic portion ML1.

[0072] The fourth lead conductor TH4 may be in electrical contact with the second external electrode 22, which is arranged in the stacking direction. The second lead conductor TH2 may be formed in a fan shape in plan view. In plan view, the periphery of the second lead conductor TH2 may be in contact with the first magnetic portion ML1.

[0073] As described above, if the base body 10 has a laminated structure comprising laminated groups G1 to G9, the design freedom of the inductor 1 is increased. For example, when manufacturing an inductor 1 having first external electrodes 21 to fourth external electrodes 24 on the bottom surface (first main surface 11) of the base body 10, it becomes easier to draw out the lead conductors to the bottom surface. The laminated structure comprising the laminated groups G1 to G9 may be laminated from the second main surface 12 side or the first main surface 11 side of the base body 10. Furthermore, the material constituting the lead conductors and / or connecting conductors V may be repeatedly printed sequentially until the desired thickness is reached, for example by screen printing, or by an inkjet method or other known method.

[0074] As described above, the base body 10 contains coils (first coil C1 and second coil C2), first to fourth lead conductors TH1 to TH4, and first magnetic portion ML1 and second magnetic portion ML2. The elements constituting the base body 10 will be described in detail below.

[0075] • Coils (First Coil and Second Coil) The coils of this embodiment include a first coil C1 and a second coil C2 that face each other in the stacking direction. The first coil C1 and the second coil C2 are magnetically coupled. In this specification, "magnetic coupling" means that the magnetic flux generated in one coil acts on the other coil.

[0076] The direction of the current flowing through the first coil C1 and the direction of the current flowing through the second coil C2 may be the same or opposite. When the direction of the magnetic flux generated by the current flowing through the first coil C1 and the direction of the magnetic flux generated by the current flowing through the second coil C2 are the same, the magnetic fluxes act to reinforce each other. On the other hand, when the direction of the magnetic flux generated by the current flowing through the first coil C1 and the direction of the magnetic flux generated by the second coil C2 are opposite, the magnetic fluxes act to destructively each other.

[0077] In a preferred configuration of the first coil C1 and second coil C2, the winding axis AX2 of the second coil C2 may be positioned on the extension of the winding axis AX1 of the first coil C1. With this configuration, the first coil C1 and the second coil C2 can be appropriately magnetically coupled.

[0078] The first coil C1 includes a plurality of first conductor layers CD1 in the stacking direction (e.g., the height direction T). Adjacent first conductor layers CD1 in the stacking direction are connected via connecting conductors V (see Figure 2). The first coil C1 may have a desired number of turns by including first conductor layers CD1 formed in two different stacking groups in the stacking direction (see Figure 2). In this embodiment, the first coil C1 may be composed of stacking group G6 and stacking group G8. Furthermore, the number of turns of the first coil C1 may be, for example, two or more by stacking the first conductor layers CD1 in the stacking direction.

[0079] It is preferable that the thickness of each first conductor layer CD1 is the same. Furthermore, it is preferable that the thickness of the first conductor layer CD1 is equal to the thickness of the second conductor layer CD2, which will be described later.

[0080] The first conductor layer CD1 may be a metallic conductor such as Ag, Cu, and / or Pd, as an example of its material. The first conductor layer CD1 may be formed, for example, by printing a conductive paste onto a magnetic layer (first magnetic portion ML1 and second magnetic portion ML2).

[0081] The second coil C2 includes a plurality of second conductor layers CD2 in the stacking direction (e.g., the height direction T). Adjacent second conductor layers CD2 in the stacking direction are connected via connecting conductors V (see Figure 2). The second coil C2 may have a desired number of turns by including second conductor layers CD2 formed in two different stacking groups in the stacking direction (see Figure 2). In this embodiment, the second coil C2 may be composed of stacking group G2 and stacking group G4. Furthermore, the number of turns of the second coil C2 may be, for example, two or more by stacking the second conductor layers CD2 in the stacking direction.

[0082] It is preferable that the thickness of the second conductor layer CD2 is the same for all of them. Furthermore, it is preferable that the thickness of the second conductor layer CD2 is the same as the thickness of the first conductor layer CD1 described above.

[0083] The second conductive layer CD2 may be a metallic conductor such as Ag, Cu, and / or Pd, as an example of its material. The second conductive layer CD2 may be formed, for example, by printing a conductive paste onto the magnetic layer (first magnetic portion ML1 and second magnetic portion ML2).

[0084] - The lead conductors (first lead conductor TH1 to fourth lead conductor TH4) electrically connect the external electrode 20 to one end or the other end of the coil (first coil C1 or second coil C2), respectively. The lead conductors may be made of the same material as the first conductor layer CD1 and the second conductor layer CD2. The lead conductors may be formed, for example, by printing a conductive paste onto the magnetic layer (first magnetic portion ML1 and second magnetic portion ML2) described above.

[0085] A preferred configuration for the lead conductors is such that the height of the lead conductors in the stacking direction is highest for the fourth lead conductor TH4, followed by the third lead conductor TH3, the second lead conductor TH2, and the first lead conductor TH1, in decreasing order. With the height of the lead conductors in the stacking direction set in this way, electrical wiring can be performed to the first external electrodes 21 to the fourth external electrodes 24, which are appropriately positioned on the mounting surface (second main surface 12), with the first coil C1 positioned above the second coil C2.

[0086] - First magnetic portion and second magnetic portion The first magnetic portion ML1 may include first metallic magnetic particles MP1 made of a magnetic material (see Figure 4B). The first metallic magnetic particles MP1 may contain Fe and / or Si. More specifically, they may be Fe particles or Fe alloy particles. Examples of Fe alloys include Fe-Si alloys, Fe-Cr alloys, Fe-Si-Cr alloys, Fe-Si-Al alloys, Fe-Si-B-P-Cu-C alloys, Fe-Si-B-Nb-Cu alloys, etc.

[0087] The average particle size of the first metallic magnetic particle MP1 is preferably 4 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less, and even more preferably 4 μm or more and 6 μm or less. The "average particle size" as used herein can be measured by the procedure described below. A sample of the inductor is cut to obtain a sample cross-section. Specifically, a sample cross-section is obtained by cutting the main body 10 (see Figure 1) through its center and the winding axis of the coil, perpendicular to the mounting surface and end face of the main body. The sample cross-section may be made flat by ion milling or the like. For the obtained cross-section, three arbitrary locations in the center of the cut surface corresponding to the central part of the main body 10 are imaged using an SEM (magnification of approximately 2000 to 3000 times). Then, in each field of view, the obtained SEM images are analyzed at three arbitrary locations in the center using image analysis software (for example, image analysis software WinROOF2021 (manufactured by Mitani Corporation)) to analyze the confirmed metallic magnetic particle DP and determine the equivalent circular diameter of the metallic magnetic particle. The average value of the obtained equivalent circle diameters is taken as the average particle size of the metallic magnetic particles. In this specification, the average particle size may mean the average particle size D50 (particle size equivalent to 50% of the cumulative percentage by volume).

[0088] The surface of the first metallic magnetic particle MP1 may be covered with a first insulating film OL1 (see Figure 4B). When the surface of the first metallic magnetic particle MP1 is covered with the first insulating film OL1, the first metallic magnetic particles MP1 are electrically insulated from each other. The first insulating film OL1 is a film produced by the oxidation of the first metallic magnetic particle MP1. The total thickness of the first metallic magnetic particle MP1 may preferably be 5 nm to 100 nm, more preferably 5 nm to 50 nm, and even more preferably 5 nm to 20 nm. The thickness of the first insulating film OL1 can be measured, for example, by taking a scan electron microscope (SEM) or transmission electron microscope (TEM) image of a cross-section obtained by polishing an inductor sample, and measuring the thickness of the first insulating film OL1 covering the surface of the metallic magnetic particle DP from the obtained SEM image. The thickness of the first insulating coating OL1 is measured by taking photographs of three arbitrary locations in the center of a cross-section cut through the center of the base body 10 and the winding axis of the coil, perpendicular to the mounting surface and end face of the base body 10. In each field of view, the thickness of the first insulating coating OL1 is measured at three arbitrary locations in the center. The average of these nine locations ((three arbitrary locations in the center of the cross-section) × (three arbitrary locations in the center of each field of view)) may be used as the thickness of the first insulating coating OL1.

[0089] The first magnetic portion ML1 has larger particle sizes of metal magnetic particles than the second magnetic portion ML2, which will be described later, resulting in a smaller void ratio between the metal magnetic particles. Therefore, the first magnetic portion ML1 has a higher packing density of metal magnetic particles and higher magnetic permeability compared to the second magnetic portion ML2, which will be described later. On the other hand, because the first magnetic portion ML1 has a higher packing density of metal magnetic particles, it has lower electrical insulation properties compared to the second magnetic portion ML2.

[0090] The second magnetic portion ML2 may include a second metallic magnetic particle MP2 composed of a magnetic material. The second metallic magnetic particle MP2 may be made of the same material as the first metallic magnetic particle MP1, or it may be made of a different material from the first metallic magnetic particle MP1, as long as it is a magnetic material.

[0091] The average particle size of the second metallic magnetic particle MP2 is preferably 1 μm or more and 4 μm or less, more preferably 1 μm or more and 3 μm or less.

[0092] The surface of the second metallic magnetic particle MP2 may be covered with a second insulating film OL2 (see Figure 4B). When the surface of the second metallic magnetic particle MP2 is covered with the second insulating film OL2, the second metallic magnetic particles MP2 are electrically insulated from each other. The second insulating film OL2 is a film produced by the oxidation of the second metallic magnetic particle MP2. The total thickness of the second metallic magnetic particle MP2 is preferably 5 nm to 100 nm, more preferably 5 nm to 50 nm, and even more preferably 5 nm to 20 nm.

[0093] The second magnetic portion ML2 has smaller particle sizes of metal magnetic particles than the first magnetic portion ML1 mentioned above, resulting in a larger void ratio between the metal magnetic particles. Therefore, the second magnetic portion ML2 has a lower packing density of metal magnetic particles and lower magnetic permeability compared to the first magnetic portion ML1. On the other hand, because the second magnetic portion ML2 has a lower packing density of metal magnetic particles, it has higher electrical insulation properties compared to the first magnetic portion ML1.

[0094] Taking advantage of the characteristics of the first magnetic portion ML1 and the second magnetic portion ML2, the inductor 1 according to this embodiment has the first magnetic portion ML1 located at least inside the windings of the first coil C1 and the second coil C2, and the second magnetic portion ML2 located between the first conductor layers CD1 in the stacking direction, between the second conductor layers CD2 in the stacking direction, and between the first conductor layer CD1 and the second conductor layer CD2 in the stacking direction.

[0095] Furthermore, by arranging the first magnetic portion ML1, which includes first metal magnetic particles MP1 having a relatively large diameter, inside the windings of the first coil C1 and the second coil C2, the magnetic permeability can be increased. As a result, the electrical characteristics of the inductor, such as its L value and DC resistance, can be improved.

[0096] Furthermore, by arranging a second magnetic portion ML2 containing second metal magnetic particles MP2, which have a relatively small diameter, between the first conductor layers CD1 in the stacking direction, between the second conductor layers CD2 in the stacking direction, and between the first conductor layer CD1 and the second conductor layer CD2 in the stacking direction, the insulation properties between the first conductor layers CD1, between the second conductor layers CD2, and between the first conductor layer CD1 and the second conductor layer CD2 can be improved.

[0097] In particular, in the inductor 1 of this embodiment, in the laminated group G3 shown in Figure 2, the second magnetic portion ML2 extends to a position where it overlaps with the third lead conductor TH3 in a plan view, and also extends to a position where it is in contact with the fourth lead conductor TH4. Therefore, in Figure 5A, the second magnetic portion ML2 is positioned at a location where the second conductor layer CD2 of laminated group G2 and the second conductor layer CD2 of laminated group G4 are close in the lamination direction (on the straight line L1 (Figure 5A) connecting these close positions). In this specification, the straight line L1 is defined as the straight line connecting the shortest distance between the second conductor layer CD2 of laminated group G2 and the second conductor layer CD2 of laminated group G4. Therefore, the insulation properties of the inductor 1 can be improved by the second magnetic portion ML2.

[0098] Similarly, in the inductor 1 of this embodiment, in the laminated group G7 shown in Figure 2, the second magnetic portion ML2 extends to a position where it overlaps with the first lead conductor TH1 in a plan view, and extends to a position where it is in contact with the second lead conductor TH2. Therefore, in Figure 5B, the second magnetic portion ML2 is positioned at a location where the first conductor layer CD1 of the laminated group G6 and the second conductor layer CD2 of the laminated group G8 are close in the lamination direction (on the straight line L2 (Figure 5B) connecting these close positions). In this specification, the straight line L2 is defined as the straight line connecting the shortest distance between the first conductor layer CD1 of the laminated group G6 and the second conductor layer CD2 of the laminated group G8. Therefore, the insulation of the inductor 1 can be improved by the second magnetic portion ML2.

[0099] Regarding a more preferred embodiment of the first magnetic portion ML1, the first magnetic portion ML1 may be arranged on the outermost side in the stacking direction of the first coil C1 and the second coil C2. Specifically, as shown in Figures 1, 2, 5A, and 5B, the first magnetic portion ML1 may be provided in the layers constituting the first main surface 11 and the second main surface 12. By providing the first magnetic portion ML1 in this way, the amount of the first magnetic portion ML1 with a high filling density of metallic magnetic particles can be increased, thereby improving electrical characteristics such as the inductor's L value and DC resistance.

[0100] Furthermore, regarding the configuration of the first magnetic portion ML1, the thickness T1 of the outermost first magnetic portion ML1 (the first magnetic portion ML1 of the laminated groups G1 and G9) may be thicker than the thicknesses T2 and T3 of the second magnetic portion ML2, as shown in Figures 5A and 5B. By setting the thickness of the first magnetic portion ML1 in this way, it is possible to increase the amount of the first magnetic portion ML1 with a higher magnetic particle filling density, thereby improving electrical characteristics such as the inductor's L value and DC resistance.

[0101] Furthermore, regarding the configuration of the second magnetic portion ML2, as shown in Figures 5A and 5B, the thickness T3 of the second magnetic portion ML2 located between the first conductor layer CD1 and the second conductor layer CD2 (the second magnetic portion ML2 corresponding to the lamination group G5) may be thicker than the thickness T2 of the second magnetic portion ML2 located between the second conductor layers CD2 (the second magnetic portion ML2 corresponding to the lamination group G3), or the thickness T2 of the second magnetic portion ML2 located between the first conductor layers CD1 (the second magnetic portion ML2 corresponding to the lamination group G7). With such a configuration, the first coil C1 and the second coil C2 can be properly insulated.

[0102] Furthermore, regarding the configuration of the second magnetic portion ML2, the second magnetic portion ML2 between two first conductor layers CD1, and the second magnetic portion ML2 between two second conductor layers CD2, may be point-symmetric with respect to the winding axes AX1 and AX2 of the first coil C1 and the second coil C2. Referring to the example shown in Figure 2, the second magnetic portion ML2 of the laminated group G3 and the second magnetic portion ML2 of the laminated group G7 are point-symmetric with respect to the winding axes AX1 and AX2 of the coils. Here, the term "point symmetry" in this specification refers not only to cases where two elements are geometrically strictly point-symmetric, but also to cases where, when one element is rotated 180°, the outer contour of that element overlaps with the outer contour of the other element, or where each side constituting the outer contour is parallel to the other side of the two elements. With this configuration, the first lead conductor TH1 to the fourth lead conductor TH4 can be properly led to the mounting surface (first main surface 11), and electrical wiring can be properly performed to the first external electrode 21 to the fourth external electrode 24.

[0103] Furthermore, with respect to the embodiment of the second magnetic portion ML2, the spacing T5 between the second magnetic portion ML2 between two first conductor layers CD1 and the second magnetic portion ML2 between the first conductor layer CD1 and the second conductor layer CD2, and the spacing T4 between the second magnetic portion ML2 between two second conductor layers CD2 and the second magnetic portion ML2 between the first conductor layer CD1 and the second conductor layer CD2 may correspond to each other. In this specification, "the spacings correspond to each other" may include embodiments in which the two spacings are identical, as well as embodiments in which there is an error of approximately ±10%. As an example, as shown in Figures 5A and 5B, the spacing T5 between the second magnetic portions ML2 between the first conductor layers CD1 and the second magnetic portion ML2 between the first conductor layer CD1 and the second conductor layer CD2, and the spacing T4 between the second magnetic portions ML2 between the second conductor layers CD2 and the second magnetic portion ML2 between the first conductor layer CD1 and the second conductor layer CD2, are all within a range of ±10%. With such a configuration, the insulating properties of the first coil C1 and the insulating properties of the second coil C2 are in a corresponding relationship, making it possible to obtain an inductor 1 with suitable insulating properties.

[0104] Furthermore, regarding the configuration of the second magnetic portion ML2, the amount of protrusion P1 (see Figure 4A) of the second magnetic portion ML2 between the first conductor layer CD1 and the second conductor layer CD2 toward the center of the element 10 may be greater than the amount of protrusion P2 of the second magnetic portion ML2 between the first conductor layers CD1 toward the center of the element 10, and the amount of protrusion P2 of the second magnetic portion ML2 between the second conductor layers CD1 toward the center of the element 10. In this specification, the amount of protrusion refers to the amount by which the second magnetic portion ML2 protrudes relative to the side surface of the second conductor layer CD2, as shown in Figure 4A. Specifically, the amount of protrusion P1 is about 60 μm or more, but the amount of protrusion P2 may be less than 60 μm, preferably 30 μm or more and less than 60 μm. With such a configuration, an inductor 1 with suitable insulating characteristics can be obtained.

[0105] -External electrodes- The external electrodes 20 are provided on the bottom surface of the base body 10. The external electrodes 20 may include a first external electrode 21, a second external electrode 22, a third external electrode 23, and a fourth external electrode 24. Providing the external electrodes 20 on the bottom surface (first main surface 11) of the base body 10 makes it possible to properly mount the inductor 1 on a mounting board or the like.

[0106] The first external electrodes 21 to the fourth external electrodes 24 may each be provided only on the first main surface 11 of the base body 10, or they may be provided spanning the first main surface 11 of the base body 10 and one or two of the surfaces adjacent to the first main surface 11 (the first side surface 13, the second side surface 14, the first end surface 15, and the second end surface 16).

[0107] The external electrode 20 may be made of various materials, such as Cu, Au, and / or Ag. The external electrode 20 may be formed by any method, but it may be a plated electrode formed by plating (e.g., electroless plating, sputtering). For example, a conductive paste containing Ag may be applied to form a baked electrode. After forming the external electrode 20, a plating layer of Ni and Sn may be further formed on the external electrode 20 using a plating method to create a multilayer structure of two or more layers.

[0108] As described above, the inductor 1 of this embodiment has a second magnetic portion ML2 containing a second metallic magnetic particle MP2 which has a smaller diameter than the first metallic magnetic particle MP1. The second magnetic portion ML2 located between the first conductor layers CD1 extends to a position that overlaps with the first lead conductor TH1 in a plan view and extends to a position that contacts the second lead conductor TH2. The second magnetic portion ML2 located between the second conductor layers CD2 extends to a position that overlaps with the third lead conductor TH3 in a plan view and extends to a position that contacts the fourth lead conductor TH4. Therefore, the likelihood of short circuits between the first conductor layers CD1, between the second conductor layers CD2, and between the first conductor layer CD1 and the second conductor layer CD2 can be further reduced, and the insulation performance can be improved.

[0109] The inductors of the following examples and comparative examples were manufactured.

[0110] (Inductor of the Example) As shown in the inductor in Figures 1 to 5B, the element 10 comprises a first magnetic portion ML1 containing first metallic magnetic particles MP1, and a second magnetic portion ML2 containing second metallic magnetic particles MP2 having a smaller diameter than the first metallic magnetic particles MP1. The first magnetic portion ML1 is located at least inside the windings of the first coil C1 and the second coil C2, and the second magnetic portion ML2 is located between the first conductor layers CD1 in the stacking direction and between the second conductor layers CD2 in the stacking direction. An inductor located between the first conductor layer CD1 and the second conductor layer CD2 in the stacking direction, wherein the second magnetic portion ML2 located between the first conductor layers CD1 extends to a position that overlaps with the first lead conductor TH1 in a plan view and extends to a position that contacts the second lead conductor TH2, and the second magnetic portion ML2 located between the second conductor layers CD2 extends to a position that overlaps with the third lead conductor TH3 in a plan view and extends to a position that contacts the fourth lead conductor TH4.

[0111] (Inductor of Comparative Example) The base body 10 comprises a first magnetic portion ML1 containing a first metallic magnetic particle MP1, and a second magnetic portion ML2 containing a second metallic magnetic particle MP2 having a smaller diameter than the first metallic magnetic particle MP1. The first magnetic portion ML1 is located at least inside the windings of the first coil C1 and the second coil C2, and the second magnetic portion ML2 is located between the first conductor layers CD1 in the stacking direction, between the second conductor layers CD2 in the stacking direction, and between the first conductor layer CD1 and the second conductor layer CD2 in the stacking direction. However, the second magnetic portion ML2 located between the first conductor layers CD1 does not extend to a position where it overlaps with the first lead conductor TH1 in a plan view, nor does it extend to a position where it touches the second lead conductor TH2, and the second magnetic portion ML2 located between the second conductor layers CD2 does not extend to a position where it overlaps with the third lead conductor TH3 in a plan view, nor does it extend to a position where it touches the fourth lead conductor TH4, in this inductor.

[0112] When the coupling coefficient between coils of the inductor manufactured as described above was measured using a network analyzer (KEYSIGHT, model number: E4990A), the result showed that the coupling coefficient between coils of the inductor of the example was 1% higher than that of the inductor of the comparative example.

[0113] Furthermore, when the manufactured inductors were inspected for electrical short circuits using an ESD device (manufactured by Hanwa Electronics Industry Co., Ltd., model number: HCE-5000) and an IR meter (manufactured by ADCMT, model number: 5451), the inductors of the example showed 0% electrical short circuits (0 out of 45 samples). On the other hand, the inductors of the comparative example showed 60% electrical short circuits (27 out of 45 samples). From these results, it was found that the inductors of the example had better insulation characteristics than the inductors of the comparative example.

[0114] The embodiments disclosed herein are illustrative in all respects and do not constitute a limiting interpretation. Therefore, the technical scope of this disclosure is not construed solely by the embodiments described above, but is defined based on the claims. Furthermore, the technical scope of this disclosure includes all modifications within the meaning and scope of equivalence to the claims.

[0115] The inductor of this disclosure can be suitably used as an electronic component that further reduces short circuits between conductor layers within the element and improves insulation.

[0116] 1 Inductor 10 Base body 11, 12 First main surface, second main surface 13, 14 First side surface, second side surface 15, 16 First end surface, second end surface 21-24 First external electrode to fourth external electrode A Notch AX1, AX2 Winding shaft C1, C2 First coil, second coil CD1, CD2 First conductor layer, second conductor layer G1-G9 Laminated group TH1-TH4 First lead conductor to fourth lead conductor ML1, ML2 First magnetic portion, second magnetic portion MP1, MP2 First metallic magnetic particle, second metallic magnetic particle OL1, OL2 First insulating coating, second insulating coating

Claims

1. An inductor comprising: a base body in which a first coil, composed of multiple stacked first conductor layers, and a second coil, composed of multiple stacked second conductor layers, are embedded overlapping each other in the stacking direction; and an external electrode disposed on the mounting surface of the base body, wherein the base body comprises: a first magnetic portion containing first metallic magnetic particles; a second magnetic portion containing second metallic magnetic particles having a smaller average particle size than the first metallic magnetic particles; a first lead conductor drawn out from one end of the first coil toward the external electrode; a second lead conductor drawn out from the other end of the first coil toward the external electrode, located further from the mounting surface than the one end of the first coil; a third lead conductor drawn out from one end of the second coil toward the external electrode; and a fourth lead conductor drawn out from the other end of the second coil toward the external electrode, located further from the mounting surface than the one end of the second coil, wherein the first magnetic portion is located at least inside the winding portions of the first coil and the second coil. The second magnetic portion is located between the first conductor layers in the stacking direction, between the second conductor layers in the stacking direction, and between the first conductor layer and the second conductor layer in the stacking direction, the second magnetic portion located between the first conductor layers extends to a position where it overlaps with the first lead conductor in a plan view from the top side of the main body, and extends to a position where it contacts the second lead conductor, and the second magnetic portion located between the second conductor layers extends to a position where it overlaps with the third lead conductor in a plan view from the top side of the main body, and extends to a position where it contacts the fourth lead conductor, in an inductor.

2. The inductor according to claim 1, wherein the second magnetic portion located between the first conductor layers comprises multiple layers, the second magnetic portion located between the first conductor layers, connected to the second lead conductor, and in contact with the first conductor layer extends to a position where it overlaps with the first lead conductor in a plan view seen from the top side of the element, and the second magnetic portion located between the first conductor layers, connected to the second lead conductor, and in contact with the first conductor layer extends until it is in contact with the second lead conductor.

3. The inductor according to claim 1 or 2, wherein the second magnetic portion located between the second conductor layers comprises multiple layers, the second magnetic portion located between the second conductor layers, connected to the third lead conductor, and in contact with the second conductor layer extends to a position where it overlaps with the third lead conductor in a plan view from the top side of the element, and the second magnetic portion located between the second conductor layers, connected to the fourth lead conductor, and in contact with the second conductor layer extends until it is in contact with the fourth lead conductor.

4. The inductor according to any one of claims 1 to 3, wherein, in a plan view taken from the top surface of the substrate, the second magnetic portion is provided so as to cover the first conductor layer and the second conductor layer.

5. The inductor according to any one of claims 1 to 4, wherein the amount of protrusion toward the center of the element in the second magnetic portion between the first conductor layer and the second conductor layer is greater than the amount of protrusion toward the center of the element in the second magnetic portion between the first conductor layers and the amount of protrusion toward the center of the element in the second magnetic portion between the second conductor layers.

6. The inductor according to any one of claims 1 to 5, wherein the first magnetic portion is also arranged on the outermost side in the stacking direction of the first coil and the second coil.

7. The inductor according to any one of claims 1 to 6, wherein the thickness of the second magnetic portion located between the first conductor layer and the second conductor layer is greater than the thickness of the second magnetic portion located between at least one of the first conductor layers and the second conductor layers.

8. In a plan view taken from the top side of the main body, the first conductor layer and the second conductor layer are provided with notches at positions among the first lead conductor to the fourth lead conductor where no electrical connection is made, as described in any one of claims 1 to 7.

9. The inductor according to any one of claims 1 to 8, wherein, in a plan view taken from the top side of the main body, the second magnetic portion located between the first conductor layers and between the second conductor layers has notches provided at positions corresponding to three locations among the first to fourth lead conductors.

10. The inductor according to claim 9, wherein the notch in the second magnetic portion located between the first conductor layers and between the second conductor layers that is in contact with any one of the first leading conductors to the fourth leading conductor has a smaller notch size than the other notches.

11. The inductor according to any one of claims 1 to 10, wherein the second magnetic portion between the first conductor layers and the second magnetic portion between the second conductor layers are point-symmetric with respect to the winding axis of the first coil and the second coil.

12. The inductor according to any one of claims 1 to 11, wherein the winding axis of the second coil is located on the extension of the winding axis of the first coil.

13. The inductor according to any one of claims 1 to 12, wherein the spacing between the second magnetic portions between the first conductor layers and the second magnetic portion between the first conductor layer and the second conductor layer corresponds to the spacing between the second magnetic portions between the second conductor layers and the second magnetic portion between the first conductor layer and the second conductor layer.

14. The inductor according to any one of claims 1 to 13, wherein the second magnetic portion between the first conductor layer and the second conductor layer is in contact with the third lead conductor and the fourth lead conductor.

15. The inductor according to any one of claims 1 to 14, wherein the second magnetic portion between the first conductor layer and the second conductor layer extends to the outer edge of the element.

16. The inductor according to any one of claims 1 to 15, wherein the first magnetic portion is provided between the outer edge of the second magnetic portion between the first conductor layers and the outer edge of the base body, and between the outer edge of the second magnetic portion between the second conductor layers and the outer edge of the base body.

17. The inductor according to any one of claims 1 to 16, wherein the permeability of the second magnetic portion is lower than the permeability of the first magnetic portion.

Images