Inductor component, method for manufacturing inductor component, and inductor structure

Abstract

The present invention provides an inductor component with a small mounting area relative to a substrate. In the inductor component (10), the lower surface of the first magnetic layer (21) becomes a first terminal surface (F1). A first inductor wiring (31) is provided inside the first magnetic layer (21). The first inductor wiring (31) is cylindrical and extends in the vertical direction. A boundary portion (50) is connected to a first internal terminal (33) of the first inductor wiring (31). The upper surface of the second magnetic layer (61) becomes a second terminal surface (F2). A second inductor wiring (71) is provided inside the second magnetic layer (61). The second inductor wiring (71) is cylindrical and extends in the vertical direction. The second internal terminal (73) of the second inductor wiring (71) is connected to the boundary portion (50). The boundary portion (50) becomes a physical boundary between the first inductor wiring (31) and the second inductor wiring (71).

Description

Technical Field

[0001] The present disclosure relates to an inductor component, a method for manufacturing an inductor component, and an inductor structure. Background Art

[0002] In the inductor component described in Patent Document 1, a ring-shaped coil core is arranged in an insulating resin layer. In addition, an inductor wiring is arranged in the insulating resin layer. The inductor wiring is wound in a spiral shape around the direction in which the coil core extends in a ring shape. A first external terminal located at a first end side of the inductor wiring is exposed on a mounting surface on a side of the outer surface of the insulating resin layer that is mounted on a substrate. A second external terminal located at a second end side of the inductor wiring is exposed on the same mounting surface as the first external terminal.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-009833 Summary of the invention

[0004] Here, two inductor components are often mounted on a substrate so that the inductor wiring is connected in series. In this case, in the inductor component described in Patent Document 1, since both ends of the inductor wiring are exposed on the same mounting surface, it is necessary to arrange the two inductor components on the same surface of the substrate and connect the wiring inside the substrate. Therefore, in order to arrange the two inductor components on the substrate, it is necessary to ensure an area for at least two inductor components on the substrate.

[0005] In order to solve the above-mentioned problems, one embodiment of the present disclosure provides an inductor component, comprising: a substrate, including a first magnetic layer composed of a magnetic material and a second magnetic layer composed of a magnetic material stacked on the first magnetic layer, and having a first terminal surface and a second terminal surface on the opposite side of the first terminal surface in the direction in which the second magnetic layer is stacked on the first magnetic layer, that is, in the stacking direction; a first inductor wiring extending linearly in the interior of the first magnetic layer along the stacking direction; a first external terminal provided at a first end of the first inductor wiring and extending only from the first end a first internal terminal disposed at a second end of the first inductor wiring on the opposite side to the first end; a second inductor wiring extending linearly along the stacking direction inside the second magnetic layer; a second internal terminal disposed at the first end of the second inductor wiring; a second external terminal disposed at the second end of the second inductor wiring on the opposite side to the first end and exposed only from the second terminal surface; and a boundary portion connecting the first internal terminal and the second internal terminal and forming a physical boundary between the first inductor wiring and the second inductor wiring.

[0006] In order to solve the above-mentioned problems, one embodiment of the present invention provides an inductor structure, which includes an inductor component, an input wiring, and an output wiring, wherein the inductor component includes: a substrate, which includes a first magnetic layer composed of a magnetic material and a second magnetic layer composed of a magnetic material stacked on the first magnetic layer, and has a first terminal surface and a second terminal surface on the opposite side of the first terminal surface in the direction in which the second magnetic layer is stacked on the first magnetic layer, that is, in the stacking direction; a first inductor wiring extending linearly in the stacking direction inside the first magnetic layer; a first external terminal provided at a first end of the first inductor wiring and exposed only from the first terminal surface; a first internal terminal provided at a second end of the first inductor wiring on the opposite side of the first end; and a second inductor wiring. , extending linearly along the stacking direction inside the above-mentioned second magnetic layer; a second internal terminal, arranged at the first end of the above-mentioned second inductor wiring; a second external terminal, arranged at the second end of the above-mentioned second inductor wiring on the opposite side of the first end, and only exposed from the above-mentioned second terminal surface; and a boundary portion, connecting the above-mentioned first internal terminal and the above-mentioned second internal terminal, and becoming the physical boundary of the above-mentioned first inductor wiring and the above-mentioned second inductor wiring, the above-mentioned input wiring applies an input voltage to the above-mentioned first external terminal of the above-mentioned inductor component, and the above-mentioned output wiring is applied with an output voltage from the above-mentioned second external terminal of the above-mentioned inductor component, and when observed from the above-mentioned stacking direction, the connection end of the above-mentioned input wiring with the above-mentioned first external terminal and the connection end of the above-mentioned output wiring with the above-mentioned second external terminal overlap at least a part.

[0007] According to the above-mentioned structures, the first inductor wiring and the second inductor wiring extending linearly in the stacking direction are connected in series via the boundary portion, the first external terminal is exposed only from the first terminal surface located at the first end side in the stacking direction, and the second external terminal is exposed only from the second terminal surface located at the second end side in the stacking direction. Therefore, compared with mounting two inductor wirings composed of different components side by side on the same mounting surface of the substrate, the area for mounting the inductor component on the substrate can be reduced.

[0008] In order to solve the above-mentioned problems, one embodiment of the present invention provides a method for manufacturing an inductor component, comprising: a first inductor wiring forming step of forming a first inductor wiring that linearly penetrates a first magnetic layer; a second inductor wiring forming step of forming a second inductor wiring that linearly penetrates a second magnetic layer; a boundary portion forming step of forming a boundary portion that connects an end portion of the first inductor wiring with an end portion of the second inductor wiring and serves as a physical boundary between the first inductor wiring and the second inductor wiring; a first external terminal forming step of forming a first external terminal that is exposed only from a first terminal surface, the first terminal surface being located on a first end side in a stacking direction of the first magnetic layer and the second magnetic layer; and a second external terminal forming step of forming a second external terminal that is exposed only from a second terminal surface, the second terminal surface being located on a second end side in the stacking direction.

[0009] According to the above structure, the first inductor wiring and the second inductor wiring extending linearly in the stacking direction are connected in series through the boundary forming step, and the first external terminal is exposed only at the first terminal surface located at the first end side in the stacking direction, and the second external terminal is exposed only at the second terminal surface located at the second end side in the stacking direction. Therefore, compared with mounting two inductor wirings composed of different components side by side on the same mounting surface of the substrate, it is possible to manufacture an inductor component with a small mounting area on the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a cross-sectional view of the inductor component according to the first embodiment.

[0011] Figure 2 This is an enlarged cross-sectional view of the boundary portion and the vicinity of the first inductor wiring in the inductor component according to the first embodiment.

[0012] Figure 3 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0013] Figure 4 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0014] Figure 5 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0015] Figure 6 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0016] Figure 7 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0017] Figure 8It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0018] Fig. 9 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0019] Fig.10 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0020] Fig.11 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0021] Fig.12 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0022] Fig.13 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0023] Fig.14 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0024] Fig.15 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0025] Fig.16 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0026] Fig.17 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0027] Fig.18 It is an explanatory diagram of the method for manufacturing the inductor component according to the first embodiment.

[0028] Fig.19 It is a cross-sectional view of the inductor component according to the second embodiment.

[0029] Fig. 20 It is an explanatory diagram of the method for manufacturing the inductor component according to the second embodiment.

[0030] Fig.21 It is an explanatory diagram of the method for manufacturing the inductor component according to the second embodiment.

[0031] Fig. 22 It is an explanatory diagram of the method for manufacturing the inductor component according to the second embodiment.

[0032] Fig.23 It is an explanatory diagram of the method for manufacturing the inductor component according to the second embodiment.

[0033] Fig.24It is an explanatory diagram of the method for manufacturing the inductor component according to the second embodiment.

[0034] Fig.25 It is a cross-sectional view of an inductor component according to a third embodiment.

[0035] Fig.26 It is an explanatory diagram of the method for manufacturing the inductor component according to the third embodiment.

[0036] Fig. 27 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0037] Fig.28 It is an explanatory diagram of the method for manufacturing the inductor component according to the third embodiment.

[0038] Fig.29 It is an explanatory diagram of the method for manufacturing the inductor component according to the third embodiment.

[0039] Fig.30 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0040] Fig.31 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0041] Fig.32 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0042] Fig.33 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0043] Fig.34 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0044] Fig.35 It is an explanatory diagram of the manufacturing method of the inductor component according to the third embodiment.

[0045] Fig.36 It is a cross-sectional view of an inductor component according to a fourth embodiment.

[0046] Fig.37 It is an explanatory diagram of a method for manufacturing an inductor component according to a fourth embodiment.

[0047] Fig.38 It is an explanatory diagram of a method for manufacturing an inductor component according to a fourth embodiment.

[0048] Fig.39 It is an explanatory diagram of a method for manufacturing an inductor component according to a fourth embodiment.

[0049] Fig.40It is an explanatory diagram of a method for manufacturing an inductor component according to a fourth embodiment.

[0050] Fig.41 It is a cross-sectional view of an embodiment of an inductor component mounting substrate.

[0051] Fig.42 It is a cross-sectional view of an inductor component according to a modified example.

[0052] Fig.43 It is a cross-sectional view of an inductor structure according to a modified example.

[0053] Description of Reference Numerals

[0054] 10…inductor component; 21…first magnetic layer; 31…first inductor wiring; 32…first external terminal; 33…first internal terminal; 50…boundary portion; 51…solder; 52…intermetallic compound; 61…second magnetic layer; 71…second inductor wiring; 72…second external terminal; 73…second internal terminal; 81…third layer base substrate; 82…copper foil; 83…first layer base substrate; 84…adhesive layer; 90…first anti-etching layer; 400…inductor component mounting substrate; 410…substrate; 420…input wiring; 440…output wiring; F1…first terminal surface; F2…second terminal surface. DETAILED DESCRIPTION

[0055] Hereinafter, various embodiments of the inductor component and the method for manufacturing the inductor component will be described. In addition, the drawings sometimes enlarge the components for easy understanding. The size ratio of the components may be different from the actual ones or from those in other drawings. In addition, sometimes only part of the components in the drawings are marked with reference numerals.

[0056] <First embodiment>

[0057] Hereinafter, a first embodiment of an inductor component and a method for manufacturing the inductor component will be described.

[0058] like Figure 1 As shown in FIG. 1 , the inductor component 10 has a structure in which three layers are stacked in the thickness direction. In the following description, the stacking direction of each of the three layers is set as the up-down direction.

[0059] The first layer L1 has a square shape when viewed from the top and bottom. The first layer L1 is composed of the first magnetic layer 21 , the first inductor wiring 31 , and the insulating film 40 .

[0060] The first magnetic layer 21 is made of a resin containing metal magnetic powder such as iron, and is a magnetic material having magnetism as a whole. In addition, in the inductor component 10, the first end side of the first layer L1 in the vertical direction, that is, the lower side surface, becomes the first terminal surface F1. In the present embodiment, the first layer L1 becomes the lowermost layer in the vertical direction, and the first terminal surface F1 faces downward.

[0061] The first inductor wiring 31 is provided inside the first magnetic layer 21. The first inductor wiring 31 is made of a conductive material, and in the present embodiment, the ratio of copper in the composition of the first inductor wiring 31 is 99 wt% or more. Although not shown in the figure, four first inductor wirings 31 are provided in the first layer L1. When the first layer L1 is viewed from the top and bottom direction, two first inductor wirings 31 are arranged in two columns along the extending direction of a pair of opposite sides of the square.

[0062] The first inductor wiring 31 is cylindrical and extends linearly in the vertical direction, i.e., the stacking direction. The vertical dimension of the first inductor wiring 31 is the same as the vertical dimension of the first magnetic layer 21. Therefore, the first end side, i.e., the lower end face of the first inductor wiring 31 in the vertical direction is coplanar with the first terminal face F1 and is exposed only from the first terminal face F1. In the present embodiment, the lower end face of the first inductor wiring 31 functions as the first external terminal 32. That is, the first external terminal 32 is provided at the first end of the first inductor wiring 31.

[0063] In addition, the second end side, i.e., the upper end face, which is the side opposite to the first end side in the up-down direction of the first inductor wiring 31, is coplanar with the surface of the first layer L1 opposite to the first terminal surface F1, and is exposed only from the opposite surface. In the present embodiment, the upper end face of the first inductor wiring 31 functions as the first internal terminal 33. That is, the first internal terminal 33 is provided at the second end of the first inductor wiring 31.

[0064] The side surfaces 34 of the first inductor wiring 31, except for the surface provided with the first external terminal 32 and the surface provided with the first internal terminal 33, are all covered with the insulating film 40. In the present embodiment, the side surface 34 is a surface orthogonal to the first terminal surface F1. The insulating film 40 is made of an insulating material, and in the present embodiment, it is epoxy resin. The film thickness of the insulating film 40 is substantially uniform.

[0065] The second layer L2 exists on the upper surface of the first layer L1. In the present embodiment, the second layer L2 is composed of four boundary portions 50 and spaces therebetween. The boundary portion 50 is connected to the first internal terminal 33 of the first layer L1. The boundary portion 50 is substantially cylindrical. The diameter of the circle when the boundary portion 50 is viewed from the top and bottom direction is larger than the diameter of the first inductor wiring 31. Therefore, when viewed from the top and bottom direction, the boundary portion 50 completely covers the first internal terminal 33.

[0066] like Figure 2 As shown, the boundary portion 50 is composed of a solder 51 and an intermetallic compound 52. The solder 51 is composed of a conductive material and contains 50 wt % or more and 99 wt % or less of tin.

[0067] The intermetallic compound 52 is a thinner layer than the solder 51. The intermetallic compound 52 is an alloy of copper and tin. The intermetallic compound 52 is formed between the first internal terminal 33 and the solder 51. Therefore, the material of the boundary portion 50 is different from the material of the first inductor wiring 31.

[0068] like Figure 1 As shown, a third layer L3 is stacked on the upper surface of the second layer L2. The third layer L3 is a square shape when viewed from the top and bottom. The length of each side of the square of the third layer L3 when viewed from the top and bottom is consistent with the length of each side of the square of the first layer L1 when viewed from the top and bottom. In this embodiment, the third layer L3 is composed of the second magnetic layer 61 and the second inductor wiring 71.

[0069] The material of the second magnetic layer 61 is the same as that of the first magnetic layer 21. In addition, in the inductor component 10, the second end side of the third layer L3 in the vertical direction, that is, the upper side surface, becomes the second terminal surface F2 mounted on the circuit board when the inductor component 10 is mounted on the circuit board. In addition, in the present embodiment, the base 11 of the inductor component 10 is constituted by the second magnetic layer 61 of the third layer L3 and the first magnetic layer 21 of the first layer L1 described above.

[0070] A second inductor wiring 71 is provided inside the second magnetic layer 61. The second inductor wiring 71 is made of the same material as the first inductor wiring 31. Although not shown in the figure, four second inductor wirings 71 are provided in the third layer L3. Each second inductor wiring 71 is connected to the upper surface of four boundary portions 50 of the second layer L2.

[0071] The second inductor wiring 71 is a columnar shape extending linearly in the vertical direction, i.e., the stacking direction. The size of the second inductor wiring 71 in the vertical direction is substantially the same as the size of the first inductor wiring 31 in the vertical direction. The cross-sectional shape of the second inductor wiring 71 in the direction perpendicular to the vertical direction is circular. Moreover, the cross-sectional shape of the second inductor wiring 71 in the direction perpendicular to the vertical direction has a smaller diameter as it approaches the upper side in the vertical direction. Therefore, the area of ​​the cross-sectional shape of the second inductor wiring 71 in the direction perpendicular to the vertical direction has a smaller area as it approaches the upper side in the vertical direction. In addition, in the present embodiment, the area of ​​the upper end where the cross-sectional area is the smallest is consistent with the area of ​​the cross-sectional shape of the first inductor wiring 31 in the direction perpendicular to the vertical direction. In this way, the second inductor wiring 71 has a tapered shape that becomes thinner as it approaches the upper side.

[0072] The size of the second inductor wiring 71 in the vertical direction is the same as the size of the second magnetic layer 61 in the vertical direction. Therefore, the second end side of the second inductor wiring 71 in the vertical direction, that is, the upper end surface is coplanar with the second terminal surface F2 of the third layer L3. Moreover, the upper end surface of the second inductor wiring 71 in the vertical direction is exposed only from the second terminal surface F2. In this embodiment, the upper end surface of the second inductor wiring 71 in the vertical direction functions as the second external terminal 72. That is, the second external terminal 72 is provided at the second end of the second inductor wiring 71.

[0073] The first end side of the second inductor wiring 71 in the vertical direction, that is, the end face on the lower side, is coplanar with the surface of the third layer L3 on the side opposite to the second terminal surface F2. Moreover, the end face on the lower side of the second inductor wiring 71 is exposed only from the surface of the second magnetic layer 61 on the side opposite to the second terminal surface F2. In the present embodiment, the end face on the lower side of the second inductor wiring 71 functions as the second internal terminal 73. That is, the second internal terminal 73 is provided at the first end on the side opposite to the second end of the second inductor wiring 71, and is located on the boundary portion 50 side of the second inductor wiring 71.

[0074] Furthermore, the second internal terminal 73 is connected to the boundary portion 50. Furthermore, the boundary portion 50 is a physical boundary between the first inductor wiring 31 and the second inductor wiring 71. Although not shown in the figure, the intermetallic compound 52 of the boundary portion 50 is also formed between the second internal terminal 73 and the solder 51. In addition, in the present embodiment, the dimension in the vertical direction of the boundary portion 50, that is, the thickness, is consistent with the vertical distance between the first internal terminal 33 and the second internal terminal 73. The thickness of the boundary portion 50 is obtained by measuring the distance between the first internal terminal 33 and the second internal terminal 73 in a cross section orthogonal to the first terminal surface F1 including the first inductor wiring 31, the boundary portion 50, and the second inductor wiring 71. The thickness of the boundary portion 50 is not less than one tenth of the diameter of a circle including the minimum diameter of the end surface on the first end side of the second inductor wiring 71. In addition, in the present embodiment, the end surface on the second end side of the first inductor wiring 31 is a circle smaller than the end surface on the first end side of the second inductor wiring 71. Therefore, the thickness of the boundary portion 50 is equal to or greater than one tenth of the diameter of a circle including the minimum diameter of the end surface on the second end side of the first inductor wiring 31 .

[0075] The thickness of the boundary portion 50 is one-third or less of the vertical dimension of the first inductor wiring 31. The thickness of the boundary portion 50 is one-third or less of the vertical dimension of the second inductor wiring 71.

[0076] In the present embodiment, the portion having the largest cross-sectional area in the cross section perpendicular to the vertical direction of the first inductor wiring 31 and the second inductor wiring 71 is the end surface on the first end side of the second inductor wiring 71. Furthermore, the maximum range of the boundary portion 50 when viewed from the vertical direction is larger than the end surface on the first end side of the second inductor wiring 71.

[0077] Furthermore, the first inductor wiring 31 and the second inductor wiring 71 are arranged in the vertical direction, that is, the stacking direction, and the central axis of the first inductor wiring 31 extending in the vertical direction coincides with the central axis of the second inductor wiring 71 extending in the vertical direction. Therefore, when the inductor component 10 is viewed from the vertical direction, the first external terminal 32 overlaps with the second external terminal 72, and the positions of the two coincide. In addition, the size of the first inductor wiring 31 in the vertical direction coincides with the size of the second inductor wiring 71 in the vertical direction.

[0078] Next, a method for manufacturing the inductor component 10 according to the first embodiment will be described.

[0079] When manufacturing the inductor component 10, first, a third layer group in which the third layer L3 is not divided into pieces is formed. In this embodiment, the third layer group is formed using a semi-additive method. Figure 3As shown in FIG. 1 , first, a base substrate 80 with copper foil is prepared. The third base substrate 81 of the base substrate 80 with copper foil is in a plate shape. A copper foil 82 is laminated on the upper surface of the third base substrate 81 in the lamination direction.

[0080] Next, a first resist layer 90 is formed. Figure 4 As shown, the first resist layer 90 is patterned, and the first resist layer 90 covers the portion of the upper surface of the copper foil 82 of the base substrate 80 with copper foil where the second inductor wiring 71 is not formed. Specifically, first, a photosensitive dry film resist is applied to the entire upper surface of the copper foil 82. Next, the portion of the upper surface of the copper foil 82 where the second inductor wiring 71 is not formed is exposed. As a result, the exposed portion of the applied dry film resist is cured. Then, the uncured portion of the applied dry film resist is removed by stripping with a chemical solution. Thus, the cured portion of the applied dry film resist is formed as the first resist layer 90. On the other hand, the copper foil 82 is exposed in the portion of the applied dry film resist that is removed by the chemical solution and is not covered by the first resist layer 90. In addition, in this embodiment, the first resist layer 90 is formed so that the gap portion where the second inductor wiring 71 is not formed has a tapered shape that becomes thinner toward the upper side by adjusting the focus during exposure, the conditions for curing, etc. That is, when observing the cross section along the vertical direction, the first resist layer 90 is formed in an inverted tapered shape that becomes thicker toward the upper side.

[0081] Next, as a second inductor wiring forming step, the second inductor wiring 71 is formed. Figure 5 As shown in FIG. 1 , the second inductor wiring 71 is formed on a portion of the upper surface of the copper foil 82 of the base substrate 80 with copper foil where the first resist layer 90 is not formed. Therefore, the second inductor wiring 71 has a shape extending linearly in the stacking direction. Specifically, the upper surface of the copper foil 82 is immersed in an electrolytic copper plating solution to perform electrolytic copper plating, and the second inductor wiring 71 having a copper ratio of 99 wt % or more is formed on the upper surface of the copper foil 82.

[0082] Next, the first resist layer 90 is peeled off. Figure 6 As shown, a part of the first resist layer 90 is physically grasped, and the first resist layer 90 and the base substrate 80 with copper foil are peeled off to be separated. In the present embodiment, the second inductor wiring 71 has a tapered shape that becomes thinner toward the upper side.

[0083] Next, the copper foil 82 protruding around the second inductor wiring 71 is removed. Specifically, the copper foil 82 exposed from the second inductor wiring 71 is removed by etching the copper foil 82.

[0084] Next, as a second magnetic layer forming step, a resin containing magnetic powder, which is a material of the second magnetic layer 61, is applied. Figure 7 As shown, a resin containing magnetic powder is applied so as to cover the upper surface of the second inductor wiring 71. Next, the resin containing magnetic powder is pressed and consolidated by a press process to form the second magnetic layer 61.

[0085] Next, as a second external terminal forming step, the upper portion of the second magnetic layer 61 is cut. Figure 8 As shown in FIG. 1 , the upper portion of the second magnetic layer 61 is cut until the upper end surface of the second inductor wiring 71, that is, the second external terminal 72 is exposed. Thus, in the second external terminal forming step, the second external terminal 72 is formed to be exposed only from the second terminal surface F2. In addition, the second magnetic layer 61 is formed around the second inductor wiring 71, and thus the linear second inductor wiring 71 passes through the second magnetic layer 61.

[0086] Next, as a second internal terminal forming step, the base substrate 80 with copper foil is removed. Fig. 9 As shown in FIG. 1 , the base substrate 80 with copper foil is cut off until the lower end surface of the second inductor wiring 71, that is, the second internal terminal 73 is exposed. At this time, in the present embodiment, the copper foil 82 is also completely cut off, so that the lower end surface of the second inductor wiring 71 is exposed from the second magnetic layer 61. Thus, in the second internal terminal forming step, the second internal terminal 73 is formed in the third layer L3 so as to be exposed only from the surface opposite to the second terminal surface F2. In addition, the second inductor wiring 71 passes through the second magnetic layer 61.

[0087] Through the second inductor wiring forming step, the second magnetic layer forming step, the second external terminal forming step, and the second internal terminal forming step, a third layer group including a plurality of third layers L3 is formed.

[0088] On the other hand, in addition to the third layer group described above, a first layer group in which the first layer L1 is not fragmented is formed. Fig.10 As shown, first, a first-layer base substrate 83 is prepared. The first-layer base substrate 83 is in a plate shape.

[0089] Next, an adhesive layer 84 is attached to the upper surface of the first base substrate 83. Fig.11 As shown, in this embodiment, the adhesive layer 84 is a sealant that can be peeled off from the first base substrate 83 after being attached. In addition, the surface of the adhesive layer 84 opposite to the first base substrate 83 can also be bonded. That is, both sides of the adhesive layer 84 are adhesive surfaces.

[0090] Next, as a first inductor wiring forming step, a metal columnar member P is bonded to the upper surface of the adhesive layer 84. Fig.12 As shown, the metal columnar component P is a cylindrical shape extending in a straight line, and is composed of a metal portion P1 and an insulating portion P2. The metal portion P1 is cylindrical. The material of the metal portion P1 is copper. The insulating portion P2 completely covers the side surface of the metal portion P1 that is perpendicular to the surface of the side bonded to the adhesive layer 84. The thickness of the insulating portion P2 is approximately uniform. The material of the insulating portion P2 is epoxy resin. As described later, in this embodiment, the metal portion P1 becomes the first inductor wiring 31, and the insulating portion P2 becomes the insulating film 40.

[0091] Next, as a first magnetic layer forming step, a resin containing magnetic powder, which is a material of the first magnetic layer 21, is applied. Fig.13 As shown, the coating is performed so as to cover the upper end surface of the metal columnar member P. Next, the resin containing the magnetic powder is pressed and fixed by a press working to form the first magnetic layer 21 .

[0092] Next, as a first internal terminal forming step, the upper portion of the first magnetic layer 21 is cut. Fig.14 As shown in FIG. 1 , the upper portion of the first magnetic layer 21 is cut until the upper end surface of the metal columnar component P is exposed. Thus, the upper end surface of the metal columnar component P is exposed, thereby forming the first internal terminal 33 of the first inductor wiring 31. That is, in the first internal terminal forming step, the first internal terminal 33 is formed in the first layer L1 so as to be exposed only from the surface opposite to the first terminal surface F1.

[0093] Next, as a first external terminal forming step, the first base substrate 83 and the adhesive layer 84 are removed. Fig.15 As shown, the adhesive layer 84 and the first base substrate 83 are physically grasped, and the upper surface of the adhesive layer 84 is separated from the lower surface of the first magnetic layer 21 in a peeling manner. As a result, the lower surface of the metal columnar component P is exposed on the lower surface of the first magnetic layer 21, thereby forming the first external terminal 32 of the first inductor wiring 31. That is, in the first external terminal forming step, the first external terminal 32 exposed only from the first terminal surface F1 is formed. In addition, the linear first inductor wiring 31 passes through the first magnetic layer 21. Therefore, the metal part P1 is configured as the first inductor wiring 31, and the insulating part P2 covering the metal part P1 is configured as the insulating film 40. As a result, the first layer group in which the first layer L1 is not divided into pieces is formed.

[0094] Next, as a boundary forming step, the first layer group and the second layer group are connected. Fig.16 As shown in FIG. 1 , first, the heated solder 51 is placed on the upper surface of the first internal terminal 33 of the first layer group. Fig.17As shown, the third layer group is stacked on the upper side of the solder 51 so that the second internal terminal 73 of the third layer group is arranged on the upper side of the solder 51. Then, the solder 51 is cooled. Thus, the intermetallic compound 52 is formed between the solder 51 and the first internal terminal 33. Similarly, the intermetallic compound 52 is formed between the solder 51 and the second internal terminal 73. Thus, the boundary portion 50 is formed, which connects the first internal terminal 33 provided at the second end of the first inductor wiring 31 and the second internal terminal 73 provided at the first end of the second inductor wiring 71, and serves as a physical boundary between the first inductor wiring 31 and the second inductor wiring 71.

[0095] Next, if Fig.18 As shown, the integrated first layer group and the third layer group are divided into pieces by cutting along the break lines DL passing through the first magnetic layer 21 and the second magnetic layer 61. In this way, the inductor component 10 can be obtained.

[0096] Next, the operation and effects of the first embodiment described above will be described.

[0097] (1-1) According to the inductor component 10 of the first embodiment described above, the first inductor wiring 31 and the second inductor wiring 71 are connected via the boundary portion 50. Furthermore, the first external terminal 32 is exposed only from the first terminal surface F1 located at the first end side in the lamination direction of the base body 11, and the second external terminal 72 is exposed only from the second terminal surface F2 located at the second end side in the lamination direction of the base body 11. Therefore, compared with assuming that two inductor wirings composed of different components are mounted side by side on the same surface of the substrate, the area for mounting the inductor component on the substrate can be reduced.

[0098] (1-2) According to the inductor component 10 of the first embodiment, the first inductor wiring 31 and the second inductor wiring 71 are arranged in the vertical direction, that is, in the stacking direction. Therefore, in the inductor component 10, the wiring through which current flows extends in the vertical direction as a whole, and it is easier to ensure the volume of the magnetic material in the base 11 than in the case where the first inductor wiring 31 and the second inductor wiring 71 are excessively bent and not arranged in parallel.

[0099] (1-3) According to the inductor component 10 of the first embodiment, when viewed from the top and bottom, the first inductor wiring 31 overlaps with the second inductor wiring 71. Therefore, compared with assuming that two inductor wirings composed of different components are mounted side by side on the same mounting surface of the substrate, the area for mounting the inductor component on the substrate can be reduced.

[0100] (1-4) According to the inductor component 10 of the first embodiment, the first external terminal 32 overlaps the second external terminal 72 when viewed from the top and bottom. Therefore, the area required for mounting the inductor component 10 can be reduced to the area of ​​the first external terminal 32 on the first terminal surface F1 and the second terminal surface F2.

[0101] (1-5) According to the inductor component 10 of the first embodiment, the material of the first inductor wiring 31 and the second inductor wiring 71 contains the most copper. Therefore, the material cost of the first inductor wiring 31 and the second inductor wiring 71 can be relatively easily reduced. In addition, the material of the boundary portion 50 is different from that of the first inductor wiring 31 and the second inductor wiring 71. Therefore, it is possible to prevent the inductor component 10 from being damaged or the like due to the same conditions acting on the inductor component 10 during the manufacturing process.

[0102] (1-6) According to the inductor component 10 of the first embodiment, the boundary portion 50 has the intermetallic compound 52 on the first inductor wiring 31 side. Therefore, the boundary portion 50 can be reliably in close contact with the first inductor wiring 31. This also applies to the boundary portion 50 and the second inductor wiring 71.

[0103] (1-7) According to the inductor component 10 of the first embodiment, the material of the boundary portion 50 contains 50 wt% or more and 99 wt% or less of tin. Therefore, when the solder 51 of the boundary portion 50 is connected to the first internal terminal 33, an alloy containing tin and copper is formed as the intermetallic compound 52. That is, if the material of the boundary portion 50 is as described above, the intermetallic compound 52 is easily formed.

[0104] (1-8) According to the inductor component 10 of the first embodiment, the thickness of the boundary portion 50 is consistent with the distance between the first internal terminal 33 and the second internal terminal 73. Moreover, the thickness of the boundary portion 50 is at least one-tenth of the diameter of the circle of the first internal terminal 33 viewed from the direction orthogonal to the first terminal surface F1. Therefore, the thickness of the boundary portion 50 is a size corresponding to the exposed area of ​​the first internal terminal 33, so that sufficient connection strength can be obtained. In addition, the thickness of the boundary portion 50 is less than one-third of the size of the second inductor wiring 71 in the vertical direction. Therefore, the thickness of the boundary portion 50 is correspondingly small. Therefore, the size of the boundary portion 50 when viewed from the vertical direction is also correspondingly small, thereby avoiding interference with the adjacent boundary portion 50.

[0105] (1-9) According to the inductor component 10 of the first embodiment, the portion of the first inductor wiring 31, the second inductor wiring 71, and the boundary portion 50 having the largest cross-sectional area in the cross section parallel to the first terminal surface F1 is the boundary portion 50. That is, when viewed from the top and bottom direction, the maximum range of the boundary portion 50 is larger than the maximum cross-sectional area in the cross section perpendicular to the top and bottom direction of the first inductor wiring 31 and the second inductor wiring 71. Therefore, it is possible to suppress the increase in the DC resistance of the inductor component 10 due to the presence of the boundary portion 50.

[0106] (1-10) According to the inductor component 10 of the first embodiment, the first inductor wiring 31 is a columnar shape extending in a direction orthogonal to the first terminal surface F1. In addition, the second inductor wiring 71 is a columnar shape extending in a direction orthogonal to the second terminal surface F2. Moreover, the central axis of the first inductor wiring 31 coincides with the central axis of the second inductor wiring 71. Therefore, when viewed from a direction orthogonal to the first terminal surface F1, the first inductor wiring 31 and the second inductor wiring 71 are substantially completely overlapped.

[0107] (1-11) According to the inductor component 10 of the first embodiment, the cross-sectional area of ​​the second inductor wiring 71 perpendicular to the extension direction is smaller as it approaches the second terminal surface F2. Therefore, the second inductor wiring 71 can increase the area for connection with the boundary portion 50 by increasing the second internal terminal 73, so that it is easy to firmly connect with the first inductor wiring 31 and the boundary portion 50. In addition, by reducing the second external terminal 72, the area for mounting the inductor component on the substrate can be reduced. In addition, during manufacturing, when the first resist layer 90 is peeled off, it is possible to suppress the first resist layer 90 from hanging on the second inductor wiring 71.

[0108] (1-12) According to the manufacturing method of the inductor component 10 of the first embodiment described above, the first inductor wiring 31 and the second inductor wiring 71 are connected via the boundary portion 50 in the boundary portion forming step. Therefore, the inductor component 10 is manufactured in which the first external terminal 32 is exposed only from the first terminal surface F1 located at the first end side in the lamination direction of the base body 11, and the second external terminal 72 is exposed only from the second terminal surface F2 located at the second end side in the lamination direction of the base body 11. Therefore, compared with assuming that two inductor wirings composed of different components are mounted side by side on the same mounting surface on the substrate, it is possible to manufacture the inductor component 10 with a smaller mounting area on the substrate.

[0109] <Second embodiment>

[0110] Hereinafter, a second embodiment of an inductor component and a method for manufacturing the inductor component will be described.

[0111] The inductor component 110 of the second embodiment mainly differs from the first embodiment in the boundary portion and the manufacturing method. In the following description, the same reference numerals are used for the same structures as those of the first embodiment, and the description thereof is omitted or simplified.

[0112] like Fig.19 As shown in FIG. 1 , the inductor component 110 has a structure in which three layers are stacked in the thickness direction. In the following description, the stacking direction of each of the three layers is set as the up-and-down direction.

[0113] The first layer L11 is composed of the first magnetic layer 121 and the first inductor wiring 131. Furthermore, the first layer L11 of the second embodiment is different from the first layer L1 of the first embodiment in that it does not include the insulating film 40.

[0114] In the first layer L11 , the first inductor wiring 131 has a first end side in the vertical direction, that is, a lower end surface, which functions as a first external terminal 132 . The first inductor wiring 131 has a second end side in the vertical direction, that is, an upper end surface, which functions as a first internal terminal 133 .

[0115] The second layer L12 is stacked on the upper surface of the first layer L11. In the second embodiment, the second layer L12 is composed of the seed layer 151, a part of the second inductor wiring 171, and the insulating layer 155. The thickness of the second layer L12 is smaller than that of the first layer L11.

[0116] An insulating layer 155 made of resin is stacked on the upper surface of the first layer L11. A plurality of holes 156 penetrate the insulating layer 155 in the vertical direction. The holes 156 are arranged above the first internal terminals 133 of the first inductor wiring 131. Therefore, the first internal terminals 133 are exposed below the holes 156.

[0117] The first internal terminal 133 of the first inductor wiring 131, the inner peripheral surface of the hole 156 of the insulating layer 155, and the vicinity of the opening edge of the hole 156 on the upper surface of the insulating layer 155 are covered with a seed layer 151 as a boundary. The material of the seed layer 151 is copper. The thickness of the seed layer 151 is not less than 1 nm and not more than 10 μm, and is about 1 μm in this embodiment. Fig.19 , the thickness of the seed layer 151 is exaggeratedly illustrated.

[0118] The second inductor wiring 171 is connected to the upper surface of the seed layer 151. The second inductor wiring 171 is generally in the shape of a column extending in the vertical direction. The lower portion 171B of the second inductor wiring 171 that is present inside the hole 156 has a smaller diameter than the upper portion 171A that is above the hole 156. In the second embodiment, the diameter of the upper portion 171A when viewed from the vertical direction is larger than the diameter of the first inductor wiring 131 when viewed from the vertical direction.

[0119] In the present embodiment, the lower portion 171B of the second inductor wiring 171 constitutes a part of the second layer L12 . In the second embodiment, the surface of the second inductor wiring 171 that is in contact with the seed layer 151 serves as the second internal terminal 173 .

[0120] The third layer L13 is stacked on the upper surface of the second layer L12. In the second embodiment, the third layer L13 is composed of the upper portion 171A of the second inductor wiring 171 and the second magnetic layer 161. The thickness of the third layer L13 is the same as that of the first layer L11. The upper end surface of the second end side in the vertical direction of the upper portion 171A of the second inductor wiring 171 functions as the second external terminal 172. In addition, in this embodiment, the second magnetic layer 161 of the third layer L13 and the first magnetic layer 121 of the first layer L11 described above constitute the base 111 of the inductor component 110.

[0121] The vertically extending central axis of the first inductor wiring 131 coincides with the vertically extending central axis of the second inductor wiring 171. Therefore, when the inductor component 110 is viewed from the vertical direction, the first external terminal 132 is within the range of the second external terminal 172.

[0122] Next, a method for manufacturing the inductor component 110 according to the second embodiment will be described.

[0123] When manufacturing the inductor component 110, first, a first layer group in which the first layer L11 is not divided is formed. The first layer group is formed by the same process as the third layer group in the first embodiment, that is, by a semi-additive method. Although detailed description is omitted, when forming the first layer group, first, a first resist layer 90 is formed on the upper surface of the base substrate 80 with copper foil, and a first inductor wiring 131 is formed in the first inductor wiring forming process. In addition, in the first layer group of the second embodiment, unlike the third layer group of the first embodiment, when forming the first resist layer 90, the focus during exposure, the conditions for curing, etc. are adjusted so that the first inductor wiring 131 is formed in a cylindrical shape.

[0124] Next, in the boundary forming step, an insulating layer 155 and a seed layer 151 constituting the second layer are formed on the upper surface of the first layer group. Fig. 20 As shown in FIG. 1 , an insulating resin is applied to the entire upper surface of the first layer. Next, the insulating resin is cured to form an insulating layer 155. Next, a hole 156 is opened by laser processing on the upper side of the first internal terminal 133 of the first inductor wiring 131 in the insulating layer 155. Thus, the first internal terminal 133 is exposed.

[0125] Next, if Fig.21 As shown, the seed layer 151 is formed by sputtering on the entire upper surface of the first layer group. That is, the seed layer 151 is stacked on the upper surface of the insulating layer 155, the inner peripheral surface of the hole 156, and the first internal terminal 133.

[0126] Next, the second inductor wiring 171 constituting the second layer L12 and the third layer L13 is formed on the upper surface of the seed layer 151. First, the second resist layer 191 is formed. Fig. 22 As shown, the second resist layer 191 covering a portion of the upper surface of the seed layer 151 where the second inductor wiring 171 is not formed is patterned.

[0127] Next, the second inductor wiring 171 is formed. The second inductor wiring 171 is formed on the portion of the upper surface of the seed layer 151 where the second resist layer 191 is not formed. Specifically, the upper surface of the seed layer 151 is immersed in an electrolytic copper plating solution to perform electrolytic copper plating, and the second inductor wiring 171 having a copper ratio of 99 wt % or more is formed on the upper surface of the seed layer 151. As a result, the seed layer 151 serves as a boundary portion between the second inductor wiring 171 and the first inductor wiring 131.

[0128] Next, the second resist layer 191 is peeled off. Although not shown in the figure, a part of the second resist layer 191 is physically grasped and the second resist layer 191 and the first layer group are peeled off to separate them. In the present embodiment, the upper portion 171A of the second inductor wiring 171 is cylindrical.

[0129] Next, the seed layer 151 protruding around the second inductor wiring 171 is removed. Specifically, the seed layer 151 is etched to remove the seed layer 151 exposed from the second inductor wiring 171.

[0130] Next, a resin containing magnetic powder is applied as a material of the second magnetic layer 161. The resin containing magnetic powder is applied so as to also cover the upper end surface of the second inductor wiring 171. Next, the resin containing magnetic powder is pressed and consolidated by a press process to form the second magnetic layer 161.

[0131] Next, the upper portion of the second magnetic layer 161 is cut. Fig.23 As shown, the upper portion of the second magnetic layer 161 is cut until the upper end surface of the second inductor wiring 171, that is, the second external terminal 172 is exposed. Thus, the upper portion 171A of the second inductor wiring 171 and the second magnetic layer 161 constituting the third layer L13 are formed.

[0132] Next, remove the base substrate with copper foil. Fig.24 As shown, the base substrate 80 with copper foil is scraped off until the lower end surface of the first inductor wiring 131, that is, the first external terminal 132 is exposed. Next, although not shown in the figure, the inductor component 110 is obtained by dicing the substrate into pieces.

[0133] Next, the operation and effects of the second embodiment are described. According to the second embodiment, in addition to the effects of (1-1) to (1-5), (1-9) to (1-10), and (1-12) described above, the following effects are also achieved.

[0134] (2-1) According to the second embodiment, the seed layer 151 functioning as the boundary portion is made of the same material as the first internal terminal 133 , that is, copper. Therefore, the connection strength between the seed layer 151 and the first internal terminal 133 can be increased.

[0135] (2-2) According to the second embodiment, the thickness of the seed layer 151 that functions as a boundary portion is greater than 1 nm. Therefore, the seed layer 151 can reliably cover the surface of the first internal terminal 133. In addition, the thickness of the seed layer 151 that is referred to as a boundary portion is less than 10 μm. Therefore, during manufacturing, the influence of sputtering on the insulating layer 155 can be reduced.

[0136] (2-3) According to the second embodiment, the diameter of the first inductor wiring 131 when viewed from the top and bottom is smaller than the diameter of the upper portion 171A of the second inductor wiring 171 when viewed from the top and bottom. For example, in order to adjust the inductance of the entire inductor component 110, it is possible to adjust either the diameter of the first inductor wiring 131 when viewed from the top and bottom or the diameter of the upper portion 171A of the second inductor wiring 171 when viewed from the top and bottom.

[0137] <Third Embodiment>

[0138] Hereinafter, a third embodiment of an inductor component and a method for manufacturing the inductor component will be described.

[0139] In the inductor component 210 of the third embodiment, the structure of the internal terminal and the position of the boundary portion of the first inductor wiring 231 are different from those of the first and second embodiments. In the following description, for the same structure as that of the first or second embodiment, the same reference numerals are used, and the description is omitted or simplified.

[0140] like Fig.25 As shown in the figure, in the inductor component 210, the first inductor wiring 231 is composed of a wiring body 231A, a first external terminal 232, and a first internal terminal 233. The wiring body 231A is cylindrical and extends in the vertical direction. The first end side of the wiring body 231A in the extending direction, that is, the end surface of the lower side, is exposed from the lower surface of the first magnetic layer 221, that is, the first terminal surface F1. In the third embodiment, the end surface of the lower side of the wiring body 231A serves as the first external terminal 232.

[0141] On the other hand, the second end side of the extension direction of the wiring body 231A, that is, the end face on the upper side, is coplanar with the upper surface of the first magnetic layer 221. Moreover, the first internal terminal 233 is connected to the upper end face of the wiring body 231A. The first internal terminal 233 has a double-layer structure having an anticorrosion layer 233A made of nickel and a solder layer 233B made of gold in this order from the wiring body 231A side. Therefore, in the third embodiment, the first internal terminal 233 protrudes from the upper surface of the first magnetic layer 221.

[0142] The insulating layer 255 is stacked on the entire upper surface of the first magnetic layer 221. The thickness of the insulating layer 255 is slightly smaller than that of the first internal terminal 233. In the third embodiment, the first layer L21 includes the first inductor wiring 231, the first magnetic layer 221, and the insulating layer 255.

[0143] The boundary portion 250 is connected to the upper side of the first internal terminal 233. The boundary portion 250 is composed of the solder 251 and two intermetallic compounds as in the first embodiment. In the third embodiment, a first intermetallic compound is formed on the upper side of the solder layer 233B of the first internal terminal 233. The first intermetallic compound is an alloy of tin and gold. Fig.25 In the figure, the boundary portion 250 and the first internal terminal 233 are shown separately, but they can also be integrated so that the interface and boundary cannot be distinguished. In addition, the gold plating of the solder layer 233B diffuses to the boundary portion 250, but the diffusion amount of gold in the boundary portion 250 is preferably less than 1.5wt%, in which case the mechanical strength of the solder can be fully ensured.

[0144] The second internal terminal 273 of the second inductor wiring 271 is connected to the upper side of the boundary portion 250. In addition, a second intermetallic compound is formed between the second internal terminal 273 and the solder 251. The second intermetallic compound is an alloy of tin and copper. The thickness of these intermetallic compounds is extremely small compared to the thickness of the solder 251, so they are omitted from the illustration.

[0145] The second inductor wiring 271 extends in a columnar shape in the vertical direction. The vertical dimension of the second inductor wiring 271 is smaller than the vertical dimension of the first inductor wiring 231. The second end side, that is, the upper end face of the second inductor wiring 271 in the extending direction serves as the second external terminal 272. Moreover, the second magnetic layer 261 is stacked on the entire upper surface of the insulating layer 255. The second magnetic layer 261 covers the side surface of the portion of the first internal terminal 233 protruding from the upper surface of the insulating layer 255 that is orthogonal to the first terminal surface F1. In addition, the second magnetic layer 261 also covers the portion of the outer surface of the boundary portion 250 except for the portion in contact with the first internal terminal 233 and the portion in contact with the second internal terminal 273. In addition, the second magnetic layer 261 also covers the side surface of the second inductor wiring 271. In the third embodiment, the third layer L23 includes the second inductor wiring 271, the second magnetic layer 261, and the boundary portion 250. Therefore, the inductor component 210 is stacked with the first layer L21 and the third layer L23. In addition, in the inductor component 210, the boundary portion 250 is arranged inside the third layer L23. The thickness of the boundary portion 250 is set to be less than one-third of the dimension in the extension direction of the second inductor wiring 271. In addition, in this embodiment, the base 211 of the inductor component 210 is composed of the second magnetic layer 261 of the third layer L23 and the first magnetic layer 221 of the first layer L21 described above.

[0146] Next, a method for manufacturing the inductor component 210 according to the third embodiment will be described.

[0147] When manufacturing the inductor component 210, first, a first layer group in which the first layer L21 is not divided is formed. Although not shown in the figure, for the first layer group, a first resist layer 90 is formed on the upper surface of the base substrate 80 with copper foil by a semi-additive method through the same process as the third layer group in the first embodiment, and the wiring body 231A of the first inductor wiring 231 is formed. Then, as shown in FIG. Fig.26 As shown, the first magnetic layer 221 is applied, and the upper portion of the first magnetic layer 221 is cut until the upper end surface of the wiring body 231A is exposed.

[0148] Next, an insulating layer 255 is applied. Fig. 27As shown, an insulating layer 255 is formed by photolithography, and the insulating layer 255 covers the upper surface of the first magnetic layer 221 and the portion of the upper end surface of the wiring body 231A where the first internal terminal 233 is not formed. Specifically, the insulating layer 255 is patterned so as to cover the portion other than the upper end surface of the wiring body 231A. In the third embodiment, the insulating layer 255 is a solder resist.

[0149] Next, the first internal terminal 233 is formed. Fig.28 As shown, a nickel anticorrosion layer 233A is formed on the upper end surface of the wiring body 231A by nickel plating. Next, a gold solder layer 233B is formed on the upper surface of the anticorrosion layer 233A by gold plating. Thus, a first layer group is formed.

[0150] On the other hand, in addition to the above-mentioned first layer group, a third layer group is formed in which the third layer L23 is not divided into pieces and does not include the second magnetic layer 261. Fig.29 As shown, a second base substrate 285 is prepared. The second base substrate 285 is in a plate shape.

[0151] Next, the adhesive layer 286 is attached to the upper surface of the second base substrate 285. The adhesive layer 286 is a sealant that can be peeled off from the second base substrate 285 after attachment. In addition, the surface of the adhesive layer 286 opposite to the second base substrate 285 can also be bonded. That is, the surfaces on both sides of the adhesive layer 286 are adhesive surfaces. Next, the copper foil 287 is bonded to the upper surface of the adhesive layer 286.

[0152] Next, the second inductor wiring 271 is formed on the upper surface of the copper foil 287. Fig.30 As shown, a second resist layer 291 is formed by photolithography to cover a portion of the upper surface of the copper foil 287 where the second inductor wiring 271 is not formed. Next, the second inductor wiring 271 is formed on the portion of the upper surface of the copper foil 287 where the second resist layer 291 is not formed. Specifically, the upper surface of the copper foil 287 is immersed in a plating solution to perform electrolytic copper plating, and the second inductor wiring 271 having a copper ratio of 99 wt % or more is formed on the upper surface of the copper foil 287. In the third embodiment, the upper end surface of the formed second inductor wiring 271 serves as the second internal terminal 273.

[0153] Next, the second resist layer 291 is peeled off. Then, as Fig.31 As shown, the copper foil 287 protruding around the second inductor wiring 271 is etched to remove the copper foil 287. Next, the solder 251 is connected to the second internal terminal 273. Thus, the third layer group without the second magnetic layer 261 is formed.

[0154] Next, the first layer group is connected to the third layer group which does not have the second magnetic layer 261. Fig.32 As shown, first, the third layer group is stacked on the upper side of the first layer group so that the solder 251 of the third layer group is arranged on the upper side of the first internal terminal 233 of the first layer group. Then, the solder 251 is cooled. Thus, a first intermetallic compound is formed between the solder 251 and the first internal terminal 233. In addition, similarly, a second intermetallic compound is formed between the solder 251 and the second internal terminal 273. As a result, the boundary portion 250 is formed.

[0155] Next, the second base substrate 285 and the adhesive layer 286 are peeled off from the copper foil 287. Fig.33 As shown, the second base substrate 285 and a portion of the adhesive layer 286 are physically grasped, and the adhesive layer 286 is peeled off from the copper foil 287 to separate them.

[0156] Next, a resin containing magnetic powder as a material of the second magnetic layer 261 is applied from the upper side of the insulating layer 255. At this time, the resin is applied so as to completely cover the copper foil 287. Next, the resin containing magnetic powder is pressed and fixed by a press process to form the second magnetic layer 261.

[0157] Next, if Fig.34 As shown in FIG. 1 , as a second external terminal forming step, the upper portion of the second magnetic layer 261 is cut away. As a result, the upper end surface of the second inductor wiring 271 is exposed, and the second external terminal 272 of the second inductor wiring 271 is formed.

[0158] Next, as a first external terminal forming step, the base substrate 80 with copper foil is removed. Fig.35 As shown in the figure, the base substrate 80 with copper foil is cut off until the lower end surface of the first inductor wiring 231, that is, the first external terminal 232 is exposed. At this time, in the third embodiment, the copper foil 82 is also completely cut off, so that the lower end surface of the first inductor wiring 231 is exposed from the first magnetic layer 221. Then, the first layer group and the third layer group that have been integrated are cut along the fracture line passing through the first magnetic layer 221 and the second magnetic layer 261 to separate them into pieces. In this way, the inductor component 210 can be obtained.

[0159] Next, the operation and effects of the third embodiment are described. According to the third embodiment, in addition to the effects (1-1) to (1-10) described above, the following effects are achieved.

[0160] (3-1) According to the third embodiment, the second inductor wiring 271 extends in a columnar shape in the vertical direction. The vertical dimension of the second inductor wiring 271 is smaller than the vertical dimension of the first inductor wiring 231. That is, the vertical dimension of the first inductor wiring 231 is different from the vertical dimension of the second inductor wiring 271. Therefore, by adjusting the length of one wiring, the length of the entire wiring can be adjusted.

[0161] <Fourth embodiment>

[0162] Hereinafter, a fourth embodiment of an inductor component and a method for manufacturing the inductor component will be described.

[0163] The inductor component 310 of the fourth embodiment mainly differs from the first embodiment in the boundary portion and the manufacturing method. In the following description, the same reference numerals are used for the same structures as those of the first embodiment, and the description is omitted or simplified.

[0164] like Fig.36 As shown in FIG. 1 , the inductor component 310 has a structure in which three layers are stacked in the thickness direction. In the following description, the stacking direction of each of the three layers is set as the up-and-down direction.

[0165] The fourth embodiment is different from the first to third embodiments in that the second layer L32 includes a buffer layer 355 and the second internal terminal 373 of the third layer L33 has a three-layer structure.

[0166] The third layer L33 is composed of the second inductor wiring 371, the second insulating film 340 and the second magnetic layer 361. The second inductor wiring 371 is composed of a wiring body 371A, a second external terminal 372 and a second internal terminal 373. The wiring body 371A is cylindrical. The side surface of the wiring body 371A that is orthogonal to the first terminal surface F1 is covered by the second insulating film 340. The material of the second insulating film 340 is the same as that of the insulating film 40. The end surface of the second end side, i.e., the upper side, of the wiring body 371A in the extending direction is exposed from the upper surface of the second magnetic layer 361, i.e., the second terminal surface F2. In the fourth embodiment, the upper side end surface of the wiring body 371A serves as the second external terminal 372. In addition, in this embodiment, the second magnetic layer 361 of the third layer L33 and the first magnetic layer 21 of the first layer L1 described above constitute the base 311 of the inductor component 310.

[0167] On the other hand, the lower end surface of the first end side of the extension direction of the wiring body 371A is coplanar with the lower surface of the second magnetic layer 361. Moreover, the second internal terminal 373 is connected to the lower end surface of the wiring body 371A. The second internal terminal 373 has a three-layer structure having, in order from the wiring body 371A side, a base layer 373A made of copper, an anti-corrosion layer 373B made of nickel, and a solder layer 373C made of gold. Therefore, in the fourth embodiment, the second internal terminal 373 protrudes from the lower surface of the second magnetic layer 361. In addition, in Fig.36 In the figure, the second internal terminal 373 is divided into three layers, but they can also be integrated so that the interface and boundary cannot be distinguished. In addition, the gold plating of the solder layer 373C diffuses to the boundary portion 350, but the diffusion amount of gold in the boundary portion 350 is preferably less than 1.5wt%, in which case the mechanical strength of the solder can be fully ensured.

[0168] Furthermore, the second internal terminal 373 is circular when viewed from the top and bottom. Furthermore, the diameter of the circle of the second internal terminal 373 when viewed from the top and bottom is larger than the diameter of the circle of the wiring body 371A.

[0169] Moreover, the second layer L32 is sandwiched between the first layer L1 and the third layer L33. The second layer L32 is composed of a boundary portion 350 and a buffer layer 355. The boundary portion 350 is arranged between the first internal terminal 33 and the second internal terminal 373, and is connected to both. When viewed from the top and bottom direction, the boundary portion 350 is circular. When viewed from the top and bottom direction, the circle of the boundary portion 350 is smaller than the circle of the second internal terminal 373.

[0170] On the upper surface of the first layer L1, a buffer layer 355 is stacked except for the portion where the boundary portion 350 is configured. The buffer layer 355 is in contact with the upper surface of the first magnetic layer 21 and is also in contact with the lower surface of the second magnetic layer 361. The surface of the boundary portion 350 and the second internal terminal 373 is covered by the buffer layer 355. Although omitted from the illustration, the buffer layer 355 is composed of a resin containing an insulating filler composed of an inorganic material and a magnetic filler composed of a magnetic material. In this embodiment, the insulating filler is composed of a needle-shaped non-magnetic material. Specifically, the material of the insulating filler is silicon dioxide. In addition, the magnetic filler is composed of a spherical magnetic body. Specifically, the material of the magnetic filler is metal magnetic powder.

[0171] Next, a method for manufacturing the inductor component 310 according to the fourth embodiment will be described.

[0172] When manufacturing the inductor component 310 , first, a first layer group in which the first layer L1 is not divided is formed. The first layer group is formed in the same manner as when forming the first layer group in the first embodiment described above.

[0173] On the other hand, in addition to the first layer group, a third layer group in which the third layer L33 is not divided is formed. First, in the same manner as when forming the first layer group of the first embodiment described above, the wiring body 371A of the second inductor wiring 371 and the second insulating film 340 are formed using the metal columnar member P. Then, the second external terminal 372 is formed in such a manner that the end surface of the second end side, i.e., the upper side, of the wiring body 371A in the extending direction is exposed from the upper surface of the second magnetic layer 361. In addition, the lower side portion of the second magnetic layer 361 is ground so that the end surface of the first end side, i.e., the lower side, of the wiring body 371A in the extending direction is coplanar with the lower surface of the second magnetic layer 361.

[0174] Then, if Fig.37 As shown, the second internal terminal 373 is formed on the end surface of the lower side of the wiring body 371A. Specifically, first, a base layer 373A composed of copper is formed by copper plating to cover the end surface of the wiring body 371A. Next, an anticorrosion layer 373B composed of nickel is formed on the surface of the base layer 373A by nickel plating. Next, a solder layer 373C composed of gold is formed on the surface of the anticorrosion layer 373B by gold plating. Thus, a second internal terminal 373 of a three-layer structure is formed. Therefore, in the fourth embodiment, the second internal terminal 373 protrudes from the lower surface of the second magnetic layer 361. Then, the third layer group is sliced ​​by cutting, thereby forming a third layer L33 having a second internal terminal 373.

[0175] Next, a solder 351 containing tin is disposed on the surface on the upper side of the first internal terminal 33 of the first layer group. Then, the third layer L33 is stacked on the first layer group so that the second internal terminal 373 is located on the upper side of the solder 351. Thus, the solder 351 is connected to the second internal terminal 373. Then, if the solder 351 is solidified, the boundary portion 350 is formed. At this time, a first intermetallic compound containing an alloy of tin and copper is formed between the solder 351 and the first internal terminal 33. In addition, a second intermetallic compound containing an alloy of tin and gold is formed between the solder 351 and the second internal terminal 373. Thus, the boundary portion 350 containing the intermetallic compound is formed.

[0176] Then, in the fourth embodiment, as Fig.38 As shown, a resin containing an insulating filler as a material of the buffer layer 355 is applied from the upper side of the first layer L1. The resin containing the insulating filler is applied so that the upper surface of the third layer L3 is also covered. Next, the resin containing the insulating filler is pressed and consolidated by a press process to form the buffer layer 355.

[0177] Next, the upper portion of the buffer layer 355 is cut. Fig.39 As shown, the buffer layer 355 is cut until the second external terminal 372 of the second inductor wiring 371 is exposed.

[0178] Then, if Fig.40 As shown, the integrated first layer group and the third layer L33 are divided into pieces by cutting along the break lines DL passing through the boundary between the buffer layer 355 and the second magnetic layer 361. Thus, the inductor component 310 can be obtained.

[0179] Next, the operation and effects of the fourth embodiment are described. According to the fourth embodiment, in addition to the effects (1-1) to (1-8) and (1-10) described above, the following effects are achieved.

[0180] (4-1) According to the fourth embodiment, the boundary portion 350 when viewed from a direction perpendicular to the first terminal surface F1 is accommodated in the second internal terminal 373. That is, when viewed from the top and bottom directions, the boundary portion 350 is smaller than the size of the second inductor wiring 371. Therefore, the boundary portion 350 can suppress interference with other boundary portions 350 arranged in the same layer.

[0181] (4-2) According to the fourth embodiment, the side surface of the boundary portion 350 perpendicular to the first terminal surface F1 is in contact with the buffer layer 355 made of resin. Therefore, the concentration of thermal stress on the boundary portion 350 can be alleviated.

[0182] (4-3) According to the fourth embodiment, the buffer layer 355 includes an insulating filler. Furthermore, the insulating filler in the buffer layer 355 is also included in the contact surface with the boundary portion 350. Therefore, by making a part of the insulating filler penetrate the boundary portion 350, the buffer layer 355 and the boundary portion 350 can be firmly connected.

[0183] (4-4) According to the fourth embodiment, the buffer layer 355 includes a magnetic filler made of a magnetic material. The magnetic filler is also included in the first magnetic layer 21 and the second magnetic layer 361. Therefore, the linear expansion coefficients of the buffer layer 355 and the first magnetic layer 21 and the second magnetic layer 361 can be made close. Therefore, the difference in the amount of expansion due to heat becomes small, thereby reducing the residual stress.

[0184] (4-5) According to the fourth embodiment, the buffer layer 355 is in contact with the first magnetic layer 21 and the second magnetic layer 361. Therefore, the buffer layer 355 is sandwiched between the first magnetic layer 21 and the second magnetic layer 361, so that the buffer layer 355 is not easily peeled off from the boundary portion 350.

[0185] <Fifth embodiment>

[0186] Hereinafter, an embodiment of an inductor structure including the inductor component illustrated in the first to fourth embodiments as one component will be described. In addition, as an example of an inductor structure, an inductor component mounting substrate including the inductor component 10 described in the first embodiment will be described below. In addition, in this embodiment, the same reference numerals as those in the first embodiment are the same structures as those in the first embodiment, and therefore their descriptions are omitted.

[0187] like Fig.41 As shown, the inductor component mounting substrate 400 is composed of the inductor component 10 and a substrate 410 electrically connected to the inductor component 10. In the present embodiment, the inductor component 10 is built inside the substrate 410.

[0188] In the fifth embodiment, the substrate 410 is roughly divided into a first substrate layer 411 , a second substrate layer 412 , and a third substrate layer 413 .

[0189] The first substrate layer 411 is plate-shaped, and a plurality of input wirings 420 are arranged inside the first substrate layer 411. Although not shown in the figure, the first end of each input wiring 420 is connected to the high potential side terminal of the DC power supply. The second end of each input wiring 420 is exposed on the upper side of the first substrate layer 411.

[0190] A second substrate layer 412 is stacked on the upper surface of the first substrate layer 411. The second substrate layer 412 is plate-shaped as a whole, and is provided with a core member 430 and the like. In addition, an inductor component 10 is provided in the second substrate layer 412. In the present embodiment, three inductor components 10 are provided. In addition, the inductor components 10 are arranged so that the first end of each input wiring 420 is in contact with each first external terminal 32 of the inductor component 10. Therefore, the number of input wirings 420 is equal to the number of first external terminals 32. In addition, the input wiring 420 applies an input voltage to the first external terminal 32 of the inductor component 10.

[0191] A third substrate layer 413 is stacked on the upper surface of the second substrate layer 412. The third substrate layer 413 is in a plate shape as a whole. A plurality of output wirings 440 are arranged inside the third substrate layer 413. The first end of each output wiring 440 is in contact with each second external terminal 72 of the inductor component 10. Therefore, the number of output wirings 440 is equal to the number of second external terminals 72. In addition, although not shown in the figure, the second end of each output wiring 440 is connected to the low potential side terminal of the DC power supply. Moreover, the output voltage is applied to the output wiring 440 from the second external terminal 72 of the inductor component 10.

[0192] Here, the end surface of the input wiring 420 as the connection end to the first external terminal 32 and the end surface of the output wiring 440 as the connection end to the second external terminal 72 are aligned in position and size when viewed from the height direction Td. Therefore, these end surfaces completely overlap when viewed from the height direction Td.

[0193] Next, the operation and effects of the fifth embodiment are described. According to the fifth embodiment, in addition to the effects (1-1) to (1-12) described above, the following effects are achieved.

[0194] (5-1) According to the inductor component mounting substrate 400 of the fifth embodiment, the first terminal surface F1 of the inductor component 10 is stacked on the first substrate layer 411 of the substrate 410, and the second terminal surface F2 of the inductor component 10 is stacked on the third substrate layer 413 of the substrate 410. In addition, the first external terminal 32 of the inductor component 10 is connected to the input wiring 420, and the second external terminal 72 of the inductor component 10 is connected to the output wiring 440. Moreover, when viewed from the height direction Td, the end surface of the input wiring 420 as the connection end to the first external terminal 32 and the end surface of the output wiring 440 as the connection end to the second external terminal 72 overlap. Therefore, after the inductor component 10 is mounted on the substrate 410, when viewed from the top and bottom direction, the minimum area required for the substrate 410 is only the area of ​​the first external terminal 32.

[0195] The above-mentioned embodiments can be implemented by modification as follows. The embodiments and the following modification examples can be implemented in combination within the range of no technical contradiction.

[0196] In the above-mentioned embodiments, the structure of the base of the inductor component is not limited to the examples in the above-mentioned embodiments. In the first embodiment, the base 11 at least includes the first magnetic layer 21 and the second magnetic layer 61, and the first terminal surface F1 and the second terminal surface F2. For example, in addition to the first magnetic layer 21 and the second magnetic layer 61, a solder resist may be provided. In this case, the solder resist may cover the lower surface of the first magnetic layer 21 in the height direction Td and the upper surface of the second magnetic layer 61 in the height direction Td, and the outer surface of the solder resist becomes the first terminal surface F1 and the second terminal surface F2. In addition, even if the first magnetic layer 21 and the second magnetic layer 61 are separated in the base 11 as in the first embodiment, it is sufficient to stack the first magnetic layer 21 and the second magnetic layer 61.

[0197] In each of the above-described embodiments, the inductor wiring only needs to be able to provide inductance to the inductor component by causing a magnetic flux to be generated in the magnetic layer when current flows therein.

[0198] In the above-mentioned embodiments, the number of groups of the first inductor wiring and the second inductor wiring is not limited to the examples in the above-mentioned embodiments. For one inductor component, there may be less than three groups of inductor wiring, or there may be more than five groups of inductor wiring. In addition, by adjusting the position of cutting during slicing, the number of groups of inductor wiring for each inductor component can also be changed.

[0199] In each of the above embodiments, when a plurality of groups of first inductor wiring and second inductor wiring are included in one inductor component, it is not necessary for all groups to have the same size. For example, the position of the boundary portion in the vertical direction may be offset, or the size of the boundary portion when viewed from the vertical direction may be different. In this case, if the boundary portions are staggered, it is easy to avoid interference with adjacent groups of inductor wiring. For example, as in the third embodiment, if the size of the first inductor wiring 231 in the extension direction is different from the size of the second inductor wiring 271 in the extension direction, the position of the boundary portion 250 in the vertical direction can be adjusted.

[0200] In the above-mentioned embodiments, the surface extending in the direction in which the inductor wiring extends does not need to be completely covered by the magnetic layer. For example, a portion of the surface extending in the direction in which the inductor wiring extends may be exposed on the outer surface of the magnetic layer.

[0201] In each of the above embodiments, the shape of the inductor wiring may not be a cylindrical shape, but may be, for example, a quadrangular prism, other polygonal prisms, an elliptical column, or a truncated cone.

[0202] In each of the above embodiments, the shape of the inductor wiring may not be a columnar shape. For example, in the case where the shape of the inductor wiring is a regular quadrangular prism, the circle of the minimum diameter that accommodates the inductor wiring when viewed from the top and bottom directions in the inductor wiring is a square circumscribed circle. In this case, if the size of the inductor wiring in the top and bottom directions is larger than the diameter of such a circumscribed circle, it is preferred in terms of miniaturizing the inductor component as a whole. Similarly, the inductor wiring is preferably columnar in terms of extending linearly from the first terminal surface F1 toward the second terminal surface F2, but even if there are curves or spirals in part, it is sufficient as long as it extends linearly as a whole. For example, the inductor wiring only needs to extend linearly as a whole, and may be partially spirally wound or partially zigzag. For example, in the case where the shape of the inductor wiring is wound with the top and bottom directions as the winding center, the circle of the minimum diameter that accommodates the inductor wiring when viewed from the top and bottom directions in the inductor wiring is larger than the circle drawn by the rotation of the inductor wiring. In this case, it is preferable to reduce the size of the entire inductor component if the vertical dimension of the inductor wiring is larger than the diameter of a circle having the smallest diameter accommodating the inductor wiring when viewed from the vertical direction in the inductor wiring.

[0203] In each of the above embodiments, the positions of the first external terminal and the second external terminal when viewed from the top and bottom do not have to be completely consistent. When viewed from the top and bottom, the first external terminal and the second external terminal may partially overlap, or the first external terminal and the second external terminal may not overlap at all. When viewed from the top and bottom, if at least a portion of the first external terminal and the second external terminal overlap, the area occupied on the terminal side of the substrate can be reduced.

[0204] In the above-mentioned embodiments, the structures of the first external terminal and the second external terminal are not limited to the examples in the above-mentioned embodiments. For example, it is also possible to have a three-layer structure as in the second internal terminal 373 in the fourth embodiment. In this case, there is a base layer composed of copper, which makes it easy to adjust the thickness of the external terminal. In addition, there is an anti-corrosion layer composed of nickel, which can suppress electromigration. In addition, the external terminal has a solder layer composed of gold, which makes it easy to ensure solder wettability when connecting to the substrate side by solder. In addition, the solder layer can also be composed of tin.

[0205] Alternatively, one of the first and second external terminals may be a plated layer as described above, and the other of the first and second external terminals may have an end surface of the first inductor wiring or the second inductor wiring in the extending direction exposed from the terminal surface.

[0206] Furthermore, when the external terminal has a laminated structure, it is preferable to include at least one of the above-mentioned anticorrosion layer and solder layer because electromigration is suppressed by the above-mentioned layers and solder wettability is easily ensured.

[0207] When the first external terminal is a component different from the first inductor wiring, and when the second external terminal is a component different from the second inductor wiring, it is preferred that the first external terminal 32 and the second external terminal 72 are in direct contact with the respective inductor wirings. If the first external terminal 32 and the second external terminal 72 are in direct contact with the respective inductor wirings, it is not necessary to further extend wiring from the inductor wirings, so that the inductor component as a whole can achieve low resistance and low profile.

[0208] In each of the above embodiments, the first external terminal may not be coplanar with the first terminal surface F1. For example, the first external terminal may be arranged at a position recessed inward from the first terminal surface F1. Thus, when the inductor component is mounted on the substrate, the recessed space abuts against the protruding portion of the substrate, thereby facilitating positioning. This also applies to the position of the second external terminal and the second terminal surface F2.

[0209] In addition, the first external terminal may be arranged at a position protruding outward from the first terminal surface F1. Thus, when the inductor component is mounted on the substrate, the protruding position can be embedded in the recessed portion of the substrate, thereby facilitating positioning. This is also the case for the position of the second external terminal and the second terminal surface F2.

[0210] In the above-mentioned embodiments, the external shape of the inductor component is not limited to the examples in the above-mentioned embodiments, and may be, for example, a cylindrical shape or a polygonal column shape.

[0211] In the above-mentioned embodiments, the material of the magnetic layer is not limited to the examples in the above-mentioned embodiments. For example, as metal magnetic powder, nickel, chromium, copper, aluminum and alloys thereof may be used. In addition, as the resin containing the metal magnetic powder, if insulation and formability are taken into consideration, polyimide resin, acrylic resin, phenolic resin are preferred, but not limited to these, and epoxy resin or the like may also be used. In addition, in the case where the magnetic layer is composed of a resin containing metal magnetic powder, it is preferred that the magnetic layer contains 60wt% or more of metal magnetic powder relative to its total weight. In addition, in order to improve the filling property of the resin containing metal magnetic powder, it is more preferred that two or three metal magnetic powders with different particle size distributions are contained in the resin. In addition, the material of the magnetic layer may be composed of a resin containing ferrite powder instead of the metal magnetic powder, or may be composed of a resin containing both metal magnetic powder and ferrite powder.

[0212] In each of the above embodiments, the central axis of the first inductor wiring may be offset from the central axis of the second inductor wiring. Fig.42 In the example shown, in the inductor component 510, the central axis CA1 of the extension direction of the first inductor wiring 31 is offset from the central axis CA2 of the extension direction of the second inductor wiring 371. In this case, the distance from the wiring around the inductor component 510 can be ensured, and the length of the inductor wiring as a whole can be increased. In addition, when the positions of the connection end of the input wiring and the connection end of the output wiring are slightly offset, there is no need to route unnecessary wiring, so flexible design can be achieved.

[0213] The method of mounting the inductor component on the substrate is not limited to the example of the fifth embodiment. For example, the inductor component may have its first terminal surface F1 connected to the upper surface of the substrate and its second terminal surface F2 connected to another component such as a submodule.

[0214] In each of the above embodiments, the boundary portion may not contain an intermetallic compound. For example, the boundary portion may be formed only of solder. In addition, even if the boundary portion contains an intermetallic compound, it may not be formed into a layer with a substantially uniform thickness. The boundary portion only needs to be a physical boundary between the first inductor wiring and the second inductor wiring that is a component different from the first inductor wiring.

[0215] In the above-mentioned embodiments, the thickness of the boundary portion is not limited to the examples in the above-mentioned embodiments. For example, when the first inductor wiring is spiral-shaped as in the above-mentioned modification, the thickness of the boundary portion may be at least one-tenth of the diameter of a circle including the minimum diameter of the end face on the boundary portion side of the first internal terminal viewed from a direction perpendicular to the first terminal face. Even in this case, the thickness of the boundary portion is a size corresponding to the exposed area of ​​the first internal terminal, so sufficient connection strength can be obtained.

[0216] The boundary portion forming step may be performed before or after the second internal terminal forming step. In either case, the boundary portion only needs to connect the first internal terminal of the first inductor wiring and the second internal terminal of the second inductor wiring.

[0217] The material of the insulating film 40 in the first embodiment is not limited to the examples in the above embodiments. For example, the insulating film 40 may be a polyimide resin, an acrylic resin, a phenolic resin, or a combination of these resins and an epoxy resin. In addition, inorganic fillers such as silicon dioxide and barium sulfate may be mixed in these resins. This is also the case in the second insulating film 340 in the fourth embodiment.

[0218] The buffer layer 355 in the fourth embodiment preferably includes a magnetic filler made of a needle-shaped magnetic material and an insulating filler made of a spherical non-magnetic material, but may include neither or both. Alternatively, the buffer layer 355 may include a magnetic filler made of a spherical magnetic body.

[0219] The inductor structure is not limited to the above-mentioned embodiment of the inductor component mounting substrate. Fig.43In the example of the inductor structure shown in the figure, the inductor component 10 is connected to the upper surface of the substrate 610 by the first terminal surface F1 of the inductor component 10. The substrate 610 is provided with an input wiring (not shown) to which an input voltage is applied, and the input wiring is connected to the first external terminal 32 of the inductor component 10. In addition, the second terminal surface F2 of the inductor component 10 is connected to another electronic component 620 such as a submodule. The electronic component 620 is provided with an output wiring (not shown) to which an output voltage is applied, and the output wiring is connected to the second external terminal 72 of the inductor component 10. In this way, the input wiring and the output wiring may be provided in different components such as the substrate 610 and the electronic component 620.

[0220] In addition, Fig.43 In the example shown, the surface on which the inductor component 10 is mounted may be not only on the substrate 610 but also on the mounting surface side of the electronic component 620 or on the substrate. In addition, another electronic component is sandwiched between the substrate 610 and the inductor component 10.

Claims

1. An inductor component, characterized in that: have: A substrate including a first magnetic layer made of a magnetic material and a second magnetic layer made of a magnetic material stacked on the first magnetic layer, and having a first terminal surface and a second terminal surface on the opposite side of the first terminal surface in the stacking direction of the first magnetic layer and the second magnetic layer; A first inductor wiring extending linearly along the stacking direction inside the first magnetic layer; a first external terminal provided at a first end of the first inductor wiring and exposed only from the first terminal surface; a first internal terminal provided at a second end of the first inductor wiring on the opposite side to the first end; A second inductor wiring extending linearly along the stacking direction inside the second magnetic layer; a second internal terminal disposed at a first end of the second inductor wiring; a second external terminal provided at a second end of the second inductor wiring on the opposite side to the first end and exposed only from the second terminal surface; as well as a boundary portion connecting the first internal terminal and the second internal terminal and serving as a physical boundary between the first inductor wiring and the second inductor wiring, The side surfaces of the outer surface of the boundary portion other than the surface in contact with the first internal terminal and the surface in contact with the second internal terminal are in contact with a buffer layer containing resin. The first terminal surface side of the buffer layer is in contact with the first magnetic layer, The second terminal surface side of the buffer layer is in contact with the second magnetic layer, The boundary portion and the surface of the second internal terminal are covered by the buffer layer, The buffer layer is composed of a resin containing an insulating filler composed of an inorganic material and a magnetic filler composed of a magnetic material. The insulating filler is made of a needle-shaped non-magnetic material.

2. The inductor component according to claim 1, characterized in that The maximum range of the boundary portion when viewed from the stacking direction is smaller than an end surface of the first internal terminal on the boundary portion side when viewed from the stacking direction and an end surface of the second internal terminal on the boundary portion side when viewed from the stacking direction.

3. The inductor component according to claim 1, characterized in that The first inductor wiring is in the shape of a column extending in the stacking direction. The second inductor wiring is in the shape of a column extending in the stacking direction. The first inductor wiring and the second inductor wiring are arranged along the stacking direction so that at least a portion of the first inductor wiring and the second inductor wiring overlap when viewed in the stacking direction. When viewed from the stacking direction, a central axis of the first inductor wiring in an extending direction is offset from a central axis of the second inductor wiring in an extending direction.

4. The inductor component according to any one of claims 1 to 3, characterized in that: When viewed from the stacking direction, at least a portion of the first external terminal and the second external terminal overlap.

5. The inductor component according to any one of claims 1 to 4, characterized in that: The material of the first inductor wiring contains the most copper, A material of the boundary portion is different from a material of the first inductor wiring.

6. The inductor component according to claim 5, characterized in that The boundary portion has an intermetallic compound on the first inductor wiring side.

7. The inductor component according to claim 5 or 6, characterized in that: The material of the boundary portion includes 50 wt % or more and 99 wt % or less of tin.

8. The inductor component according to any one of claims 3 to 5, characterized in that: The first inductor wiring is in the shape of a column extending in the stacking direction. A distance between the first internal terminal and the second internal terminal along the stacking direction is not less than one tenth of a diameter of a circle including a minimum diameter of an end surface on the second end side of the first inductor wiring and not more than one third of a maximum dimension of the first inductor wiring in the stacking direction.

9. The inductor component according to any one of claims 1 to 4, characterized in that: The material of the first inductor wiring contains the most copper, The material of the boundary portion contains the most copper.

10. The inductor component according to claim 9, characterized in that The dimension of the boundary portion in the stacking direction, that is, the thickness, is greater than or equal to 1 nm and less than or equal to 10 μm.

11. The inductor component according to claim 1 or 3, characterized in that: A maximum range of the boundary portion when viewed in the stacking direction is larger than a maximum cross-sectional area of ​​the first inductor wiring and the second inductor wiring in a cross section perpendicular to the stacking direction.

12. The inductor component according to claim 3, characterized in that A dimension of the first inductor wiring in an extending direction is different from a dimension of the second inductor wiring in an extending direction.

13. The inductor component according to claim 3 or 12, characterized in that: A diameter of a circle including a minimum diameter of the first inductor wiring when viewed from the stacking direction is different from a diameter of a circle including a minimum diameter of the second inductor wiring when viewed from the stacking direction.

14. The inductor component according to claim 1 or 2, characterized in that: The first inductor wiring extends along the stacking direction, A cross-sectional area of ​​a cross section of the first inductor wiring that is perpendicular to the stacking direction varies depending on a position of the first inductor wiring in the stacking direction.

15. The inductor component according to claim 1, characterized in that The buffer layer includes at least one filler consisting of a magnetic material and a non-magnetic material.

16. An inductor structure, characterized in that: An inductor component, an input wiring, and an output wiring are provided. The inductor component comprises: A substrate including a first magnetic layer made of a magnetic material and a second magnetic layer made of a magnetic material stacked on the first magnetic layer, and having a first terminal surface and a second terminal surface on the opposite side of the first terminal surface in the direction in which the second magnetic layer is stacked on the first magnetic layer, that is, in the stacking direction; A first inductor wiring extending linearly along the stacking direction inside the first magnetic layer; a first external terminal provided at a first end of the first inductor wiring and exposed only from the first terminal surface; a first internal terminal provided at a second end of the first inductor wiring on the opposite side to the first end; A second inductor wiring extending linearly along the stacking direction inside the second magnetic layer; a second internal terminal disposed at a first end of the second inductor wiring; a second external terminal provided at a second end of the second inductor wiring on the opposite side to the first end and exposed only from the second terminal surface; as well as a boundary portion connecting the first internal terminal and the second internal terminal and serving as a physical boundary between the first inductor wiring and the second inductor wiring, The input wiring applies an input voltage to the first external terminal of the inductor component, The output wiring is applied with an output voltage from the second external terminal of the inductor component, When viewed from the stacking direction, at least a portion of the connection end of the input wiring to the first external terminal and the connection end of the output wiring to the second external terminal overlap. The side surfaces of the outer surface of the boundary portion other than the surface in contact with the first internal terminal and the surface in contact with the second internal terminal are in contact with a buffer layer containing resin. The first terminal surface side of the buffer layer is in contact with the first magnetic layer, The second terminal surface side of the buffer layer is in contact with the second magnetic layer, The boundary portion and the surface of the second internal terminal are covered by the buffer layer, The buffer layer is composed of a resin containing an insulating filler composed of an inorganic material and a magnetic filler composed of a magnetic material. The insulating filler is made of a needle-shaped non-magnetic material.

17. The inductor structure according to claim 16, wherein: The maximum range of the boundary portion when viewed from the stacking direction is smaller than an end surface of the first internal terminal on the boundary portion side when viewed from the stacking direction and an end surface of the second internal terminal on the boundary portion side when viewed from the stacking direction.

18. The inductor structure according to claim 16, wherein: The first inductor wiring is in the shape of a column extending in the stacking direction. The second inductor wiring is in the shape of a column extending in the stacking direction. The first inductor wiring and the second inductor wiring are arranged along the stacking direction so that at least a portion of the first inductor wiring and the second inductor wiring overlap when viewed in the stacking direction. When viewed from the stacking direction, a central axis of the first inductor wiring in an extending direction is offset from a central axis of the second inductor wiring in an extending direction.

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