Coil component

Abstract

The present invention relates to a coil component in which, in a cross-section orthogonal to the extension direction of a second wiring part, there are a first region in which an adhesion layer and an element body layer are in direct contact and a second region in which a main body part and the element body layer are in direct contact, so that, for example, even if the electrical resistivity of the adhesion layer is higher than the electrical resistivity of the main body part, the electrical resistivity of the main body part is lower than that of the first region. Thus, the resistance due to the high-frequency current of the skin effect can be reduced, and a high self-resonant frequency can be achieved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a coil component. BACKGROUND

[0002] A coil component disclosed in Japanese Patent Application Publication No. 2014-232815 has a body having a laminated structure composed of a plurality of insulating layers and a coil conductor provided in the body, and a wiring portion (for example, a strip conductor) constituting the coil conductor is formed by plating. SUMMARY

[0003] PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] The inventors and others have arrived at the following insight: by interposing an adhesion layer between a main portion of the wiring portion of the coil conductor and the insulating layer constituting the body, the adhesion between the wiring portion and the insulating layer becomes higher. However, in the case where the resistivity of the adhesion layer is higher than the resistivity of the main portion, when the coil component is applied to a high-frequency circuit, high-frequency current easily flows to the adhesion layer having high resistivity due to the skin effect, and thus, a decrease in self-resonance frequency can occur.

[0005] According to various aspects of the present disclosure, a coil component is provided that achieves an increase in self-resonance frequency.

[0006] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0007] One aspect of the present disclosure provides a coil component including: a body composed of a plurality of insulating layers laminated; and a coil conductor provided in the body and including a wiring portion extending in a direction orthogonal to a laminating direction of the body and overlapping a first insulating layer among the plurality of insulating layers in the laminating direction, the wiring portion having a main portion and an adhesion layer interposed at a portion of an interface between the main portion and the first insulating layer in a cross section orthogonal to the extending direction of the wiring portion, and a first region in which the adhesion layer directly contacts the first insulating layer and a second region in which the main portion directly contacts the first insulating layer being present.

[0008] In the coil component, in the cross section orthogonal to the extending direction of the wiring portion, the first region in which the adhesion layer directly contacts the first insulating layer and the second region in which the main portion directly contacts the first insulating layer are present, and thus, for example, even in the case where the resistivity of the adhesion layer is higher than the resistivity of the main portion, a decrease in resistance due to high-frequency current caused by the skin effect is achieved, and thus, a high self-resonance frequency can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 FIG. 1 is a perspective view of a coil component according to an embodiment.

[0010] Figure 2 FIG. 2 is a cross-sectional view of the coil component according to the embodiment. Figure 1A perspective view of the coil conductor.

[0011] Figure 3 is a perspective view of the coil member. Figure 1 An exploded perspective view of the structure of each layer of the coil member shown in

[0012] Figure 4 is a perspective view of the coil member. Figure 3 A view of the structure of the wiring portion of the first elementary layer shown in

[0013] Figure 5 is a view of the structure of the wiring portion of the second elementary layer shown in Figure 4 A V-V line sectional view of the second wiring portion shown in

[0014] Figure 6 is a view of the structure of the wiring portion of the third elementary layer shown in Figure 3

[0015] Figure 7 is a view of the structure of the wiring portion of the fourth elementary layer shown in Figure 3

[0016] Figure 8 is a VIII-VIII line sectional view of the first wiring portion shown in Figure 7

[0017] Figure 9 is a view of the structure of the wiring portion of the fifth elementary layer shown in Figure 3

[0018] Figure 10 is a view of the structure of the wiring portion of the fifth elementary layer shown in Figure 3

[0019] Figure 11 is a flowchart showing the order of the manufacturing method of the coil member shown in Figure 1

[0020] Figure 12 is a side view of the coil member shown in Figure 1 DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the attached drawings. Also, in the explanation of the drawings, the same or equivalent elements are marked with the same reference numerals, and repeated explanation will be omitted.

[0022] The coil member of the present embodiment will be explained with reference to Figure 1 Figure 1 , 2 ​​​​​​​​As shown, the coil component 1 of one embodiment is configured to include a base body 2, a pair of bottom electrodes 3, 4, and a coil conductor 5. The coil conductor 5 is provided in the base body 2 and is configured to include a plurality of second wiring portions 6, a plurality of pairs of leg portions 8, and a plurality of first wiring portions 7, as described later. Specifically, the coil conductor 5 includes five second wiring portions 6, five pairs of leg portions 8, and four first wiring portions 7. The coil conductor 5 has a coil axis in the second direction D2, which is described later, and rotates around the coil axis. The coil conductor 5 of this embodiment rotates around the coil axis by substantially 4.5 turns. The number of turns of the coil conductor 5 can be appropriately increased or decreased. Along with this, the number of pairs of leg portions 8, the number of first wiring portions 7, and the number of second wiring portions 6 can also be increased or decreased.

[0023] The base body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a shape of a rectangular parallelepiped in which the corner portions and the edge line portions are chamfered and a shape of a rectangular parallelepiped in which the corner portions and the edge line portions are rounded. The base body 2 has, as an outer surface, a pair of end surfaces 2a, 2b, a pair of major surfaces 2c, 2d, and a pair of side surfaces 2e, 2f. The end surfaces 2a, 2b face each other. The major surfaces 2c, 2d face each other. The side surfaces 2e, 2f face each other. Hereinafter, the facing direction of the end surfaces 2a, 2b is referred to as a first direction D1, the facing direction of the side surfaces 2e, 2f is referred to as a second direction D2, and the facing direction of the major surfaces 2c, 2d is referred to as a third direction D3. The first direction D1, the third direction D3, and the second direction D2 are substantially orthogonal to each other.

[0024] The end surfaces 2a, 2b extend in the third direction D3 so as to join the major surfaces 2c, 2d. The end surfaces 2a, 2b also extend in the second direction D2 so as to join the side surfaces 2e, 2f. The major surfaces 2c, 2d extend in the first direction D1 so as to join the end surfaces 2a, 2b. The major surfaces 2c, 2d also extend in the second direction D2 so as to join the side surfaces 2e, 2f. The side surfaces 2e, 2f extend in the first direction D1 so as to join the end surfaces 2a, 2b. The side surfaces 2e, 2f also extend in the third direction D3 so as to join the major surfaces 2c, 2d.

[0025] The major surface 2d is a mounting surface of the base body 2, which is a surface that faces another electronic device, such as a circuit substrate or a laminated electronic component, when the coil component 1 is mounted to the other electronic device, which is not shown. The end surfaces 2a, 2b are surfaces that are continuous from the mounting surface, that is, the major surface 2d.

[0026] The length of the base body 2 in the first direction D1 is longer than the length of the base body 2 in the third direction D3 and the length of the base body 2 in the second direction D2. The length of the base body 2 in the third direction D3 is shorter than the length of the base body 2 in the second direction D2. That is, in this embodiment, the end faces 2a, 2b, the main faces 2c, 2d, and the side faces 2e, 2f are rectangular. The length of the base body 2 in the third direction D3 can be equal to or longer than the length of the base body 2 in the second direction D2.

[0027] Furthermore, in this embodiment, "equal" can mean not only equal, but also values ​​that include minor differences or manufacturing errors within a predetermined range. For example, multiple values ​​are defined as equal as long as they are within ±5% of the average of the multiple values.

[0028] like Figure 3 As shown, the substrate 2 has a structure formed by stacking multiple substrate layers (insulating layers) on a third direction D3. In this embodiment, the substrate 2 is composed of nine substrate layers 21 to 29. That is, the stacking direction of the substrate 2 is consistent with the third direction D3. Wiring portions 6, 7, 8a to 8f constituting the coil conductor 5 are embedded in substrate layers 22 to 28. As explained by the manufacturing method described later, the substrate 2 can be manufactured by sequentially stacking substrate layers 22 to 29 on substrate layer 21. In the actual substrate 2, the multiple substrate layers 21 to 29 can be integrated to the point where the boundaries between the layers are indistinguishable, or they can be integrated to the point where the boundaries between the layers are distinguishable.

[0029] Each substrate layer 21-29 is primarily composed of an insulating material, such as a resin material. The resin material may include, for example, at least one selected from liquid crystal polymers, polyimide resins, crystalline polystyrene, epoxy resins, acrylic resins, bismaleimide resins, and fluorine resins. The resin material may also be a transparent material, in which case the substrate 2 is transparent, allowing the coil conductor 5 to be identified from the outside of the substrate 2. The resin material may or may not contain fillers. Fillers may be, for example, inorganic fillers. Examples of inorganic fillers include silicon dioxide. Furthermore, each substrate layer 21-29 may also be composed of a magnetic material. Magnetic materials may include, for example, Ni-Cu-Zn ferrite materials, Ni-Cu-Zn-Mg ferrite materials, or Ni-Cu ferrite materials. Magnetic materials may also include, for example, Fe alloys. Each substrate layer 21-29 may also contain non-magnetic materials, which may be glass-ceramic materials or dielectric materials. Each wiring section 6, 7, 8a to 8f is made of a conductive material (e.g., Cu).

[0030] The substrate layer 21 is composed solely of the aforementioned insulating material. The substrate layer 21 is located at the bottom of the substrate 2 and forms the main surface 2c.

[0031] As Figure 3 and Figure 4 shown, the bulk layer 22 has a plurality of second wiring portions 6 (lower wiring portions) buried therein, and the bulk layer 22 of the present embodiment includes five second wiring portions 6. The plurality of second wiring portions 6 each extend in parallel along the first direction Dl, and have the same length in the first direction Dl. The plurality of second wiring portions 6 are arranged at equal intervals in the second direction D2. The plurality of second wiring portions 6 are arranged separately from the end surfaces 2a, 2b and the side surfaces 2e, 2f of the bulk 2. One end portion 6a of the extension direction of each second wiring portion 6 is located in the vicinity of the end surface 2a, and the other end portion 6b is located in the vicinity of the end surface 2b. Since the bulk layer 22 is stacked directly above the bulk layer 21 constituting the main surface 2c, the plurality of second wiring portions 6 are located on the main surface 2c side of the bulk 2. In the following description, the bulk layer 22 is also referred to as a first bulk layer.

[0032] As Figure 5 shown, each second wiring portion 6 has a substantially rectangular cross section in a cross section orthogonal to the extension direction thereof (i.e., the first direction Dl), and has four corners including two corners 6k that are in contact with the bulk layer 21 (first insulating layer). In addition, each second wiring portion 6 is constituted by a main body portion 9 and a close-contact layer 10 in a cross section orthogonal to the extension direction thereof. The main body portion 9 has a substantially rectangular cross section, and is composed of a metal material. Specifically, the main body portion 9 is composed of Cu, and more specifically, is composed by plating Cu. The close-contact layer 10 is interposed at a portion of the interface between the main body portion 9 and the bulk layer 21. The close-contact layer 10 has a thin layer-like cross section, and is composed of a metal material. Specifically, the close-contact layer 10 is composed of a material having a higher close-contact force with the bulk layer 21 than the material constituting the main body portion 9, and more specifically, is composed of Cr. By interposing the close-contact layer 10 at the interface between the main body portion 9 and the bulk layer 21, the close-contact force of the second wiring portion 6 with the bulk layer 21 is improved compared to the case where the close-contact layer 10 is not interposed. In the case where the main body portion 9 is formed by electroplating, the close-contact layer 10 can be used as a seed layer. At this time, as necessary, a coating layer that coats the surface of the close-contact layer 10 or the bulk layer 21 can also be formed by Cu sputtering.

[0033] As Figure 5 shown, the second direction length Wl of the close-contact layer 10 is shorter than the second direction length W2 of the main body portion 9. Therefore, there is a first region Rl where the close-contact layer 10 is in direct contact with the bulk layer 21, and a second region R2 where the main body portion 9 is in direct contact with the bulk layer 21. More specifically, there is one first region Rl, and a pair of second regions R2 sandwiching the first region Rl in the second direction D2. Therefore, both of the corners 6k of the second wiring portion 6 that are in contact with the bulk layer 21 correspond to the second region R2, and are composed of the main body portion 9 (i.e., composed of Cu of the main body portion 9).

[0034] AsFigure 3 and Figure 6 As shown in FIG. 10, the wiring portions 8a to 8d (pillar conductors) are buried in the bulk layers 23 to 26, respectively, and constitute a pillar portion 8 extending in the third direction D3. The wiring portions 8a to 8d are provided at the same position in any of the bulk layers 23 to 26, and overlap each other in the third direction D3. In the following description, the bulk layers 23 to 26 are all referred to as the second bulk layer.

[0035] Each of the wiring portions 8a to 8d is composed of a plurality of pairs of portions arranged in the first direction Dl, and in the present embodiment, is composed of five pairs. Specifically, each of the wiring portions 8a to 8d is arranged in two rows in the second direction D2, and is arranged at equal intervals in the second direction D2. In the following description, the row on the end surface 2a side of each of the wiring portions 8a to 8d arranged in two rows is referred to as the first row 8A, and the row on the end surface 2b side is referred to as the second row 8B. The wiring portions 8a to 8d of the first row 8A are arranged at positions corresponding to one end portion 6a of the second wiring portion 6, and the wiring portions 8a to 8d of the second row 8B are arranged at positions corresponding to the other end portion 6b of the second wiring portion 6. In the present embodiment, each of the wiring portions 8a to 8d has a substantially rectangular shape (for example, a substantially square shape) as viewed in the third direction D3. Each of the wiring portions 8a to 8d can also have a circular shape, an elliptical shape, or a polygonal shape other than a quadrangular shape as viewed in the third direction D3.

[0036] As shown in FIG. 11, the first wiring portion 7 is buried in the bulk layer 27, and in the present embodiment, the bulk layer 27 contains four first wiring portions 7. In the following description, the bulk layer 27 is referred to as the third bulk layer. Each of the first wiring portions 7 has a pair of end portions 7a, 7b and an inclined portion 7c interposed between the pair of end portions 7a, 7b. The pair of end portions 7a, 7b and the inclined portion 7c are continuous, and the pair of end portions 7a, 7b are located on both sides of the inclined portion 7c in the first direction Dl. The pair of end portions 7a, 7b is composed of the first end portion 7a located at a position close to the end surface 2a of the bulk 2 and the second end portion 7b located at a position close to the end surface 2b of the bulk 2. As viewed in the third direction D3, the pair of end portions 7a, 7b are offset from each other in the second direction D2. In the present embodiment, as viewed in the third direction D3, the first end portion 7a is located closer to the side surface 2f than the second end portion 7b. The inclined portion 7c extends in a direction inclined at a prescribed angle with respect to the first direction Dl, and connects the pair of end portions 7a, 7b offset from each other in the second direction D2. The angle of inclination with respect to the first direction Dl is the same for all of the first wiring portions 7. That is, the inclined portions 7c of the first wiring portions 7 have a parallel relationship with each other. In the present embodiment, the four first wiring portions 7 are composed of the first wiring portion 7A, the first wiring portion 7B, the first wiring portion 7C, and the first wiring portion 7D arranged in this order from the side close to the side surface 2f. Figure 3 Figure 7 As shown in FIG. 11, the first wiring portion 7 is buried in the bulk layer 27, and in the present embodiment, the bulk layer 27 contains four first wiring portions 7. In the following description, the bulk layer 27 is referred to as the third bulk layer. Each of the first wiring portions 7 has a pair of end portions 7a, 7b and an inclined portion 7c interposed between the pair of end portions 7a, 7b. The pair of end portions 7a, 7b and the inclined portion 7c are continuous, and the pair of end portions 7a, 7b are located on both sides of the inclined portion 7c in the first direction Dl. The pair of end portions 7a, 7b is composed of the first end portion 7a located at a position close to the end surface 2a of the bulk 2 and the second end portion 7b located at a position close to the end surface 2b of the bulk 2. As viewed in the third direction D3, the pair of end portions 7a, 7b are offset from each other in the second direction D2. In the present embodiment, as viewed in the third direction D3, the first end portion 7a is located closer to the side surface 2f than the second end portion 7b. The inclined portion 7c extends in a direction inclined at a prescribed angle with respect to the first direction Dl, and connects the pair of end portions 7a, 7b offset from each other in the second direction D2. The angle of inclination with respect to the first direction Dl is the same for all of the first wiring portions 7. That is, the inclined portions 7c of the first wiring portions 7 have a parallel relationship with each other. In the present embodiment, the four first wiring portions 7 are composed of the first wiring portion 7A, the first wiring portion 7B, the first wiring portion 7C, and the first wiring portion 7D arranged in this order from the side close to the side surface 2f.​

[0037] The first end portion 7a of the first wiring portion 7 overlaps one of the wiring portions 8a to 8d and one end portion 6a of one of the second wiring portions 6 in the first column 8A, as viewed in the third direction D3. The second end portion 7b of the first wiring portion 7 overlaps one of the wiring portions 8a to 8d and one end portion 6b of one of the second wiring portions 6 in the second column 8B, as viewed in the third direction D3. In the present embodiment, the second end portion 7b of the first wiring portion 7A overlaps the first wiring portion 8a to 8d from the side 2f and the end portion 6b of the first second wiring portion 6 from the side 2f, and the first end portion 7a overlaps the second wiring portion 8a to 8d from the side 2f and the end portion 6a of the second second wiring portion 6 from the side 2f. The second end portion 7b of the first wiring portion 7B overlaps the second wiring portion 8a to 8d from the side 2f and the end portion 6b of the second second wiring portion 6 from the side 2f, and the first end portion 7a overlaps the third wiring portion 8a to 8d from the side 2f and the end portion 6a of the third second wiring portion 6 from the side 2f. The second end portion 7b of the first wiring portion 7C overlaps the third wiring portion 8a to 8d from the side 2f and the end portion 6b of the third second wiring portion 6 from the side 2f, and the first end portion 7a overlaps the fourth wiring portion 8a to 8d from the side 2f and the end portion 6a of the fourth second wiring portion 6 from the side 2f. The second end portion 7b of the first wiring portion 7C overlaps the fourth wiring portion 8a to 8d from the side 2f and the end portion 6b of the fourth second wiring portion 6 from the side 2f, and the first end portion 7a overlaps the fifth wiring portion 8a to 8d from the side 2f and the end portion 6a of the fifth second wiring portion 6 from the side 2f.

[0038] Similar to the second wiring section 6, each first wiring section 7 has a generally rectangular cross-section in a section orthogonal to its extending direction, and has four corners including two corners 7k that are in contact with the substrate layer 26 (first insulating layer). Furthermore, similar to the second wiring section 6, each first wiring section 7 is constructed by including a main body 9 and an adhesive layer 10 in a cross-section orthogonal to its extending direction. The main body 9 has a generally rectangular cross-section and is made of a metallic material. Specifically, the main body 9 is made of Cu, and more specifically, it is constructed by Cu plating. The adhesive layer 10 is disposed at a portion of the interface between the main body 9 and the substrate layer 26. The adhesive layer 10 has a thin, layered cross-section and is made of a metallic material. Specifically, the adhesive layer 10 is made of a material whose adhesion to the substrate layer 26 is higher than that of the main body 9, and more specifically, it is made of Cr. By providing an adhesion layer 10 at the interface between the main body 9 and the substrate layer 26, the adhesion force of the first wiring portion 7 to the substrate layer 26 is improved compared to the case where the adhesion layer 10 is not provided. When the main body 9 is formed by electroplating, the adhesion layer 10 can be used as a seed layer. At this time, if necessary, a coating layer covering the surface of the adhesion layer 10 or the substrate layer 26 can also be formed by Cu sputtering.

[0039] like Figure 8 As shown, the second-direction length W1 of the adhering layer 10 is shorter than the second-direction length W2 of the main body 9. Therefore, there is a first region R1 where the adhering layer 10 is directly connected to the substrate layer 21, and a second region R2 where the main body 9 is directly connected to the substrate layer 26. More specifically, there is one first region R1 and a pair of second regions R2 sandwiched between the first region R1 in the second direction D2. Therefore, the two corner portions 7k that are connected to the substrate layer 26 of the first wiring portion 7 are both equivalent to the second regions R2 and are constituted by the main body 9 (i.e., constituted by the Cu of the main body 9).

[0040] Additionally, a pair of wiring portions 8e (first lead-out wiring portions) are embedded in the substrate layer 27. One of the pair of wiring portions 8e is positioned to overlap with one of the wiring portions 8a-8d in the first column 8A, and the other of the pair of wiring portions 8e is positioned to overlap with one of the wiring portions 8a-8d in the second column 8B. In this embodiment, one of the pair of wiring portions 8e overlaps with the first wiring portion 8a-8d from the side 2f among the wiring portions 8a-8d in the first column 8A, and also overlaps with the end 6a of the first second wiring portion 6 from the side 2f, forming the end 5a of the coil conductor 5. The other of the pair of wiring portions 8e overlaps with the fifth wiring portion 8a-8d from the side 2f among the wiring portions 8a-8d in the second column 8B, and also overlaps with the end 6b of the fifth second wiring portion 6 from the side 2f, forming the end 5b of the coil conductor 5.

[0041] like Figure 3 and Figure 9As shown, a pair of wiring portions 8f (second lead-out wiring portions) are embedded in the bulk layer 28. The pair of wiring portions 8f are provided at positions overlapping the pair of wiring portions 8e of the bulk layer 27, respectively. The wiring portions 8f of the pair of wiring portions 8f on the end surface 2a side and the side surface 2f side constitute the end portion 5a of the coil conductor 5, and the wiring portions 8f on the end surface 2b side and the side surface 2e side constitute the end portion 5b of the coil conductor 5. In the following description, the bulk layer 28 is referred to as the fourth bulk layer.

[0042] As shown, a pair of wiring portions 8f (second lead-out wiring portions) are embedded in the bulk layer 28. The pair of wiring portions 8f are provided at positions overlapping the pair of wiring portions 8e of the bulk layer 27, respectively. The wiring portions 8f of the pair of wiring portions 8f on the end surface 2a side and the side surface 2f side constitute the end portion 5a of the coil conductor 5, and the wiring portions 8f on the end surface 2b side and the side surface 2e side constitute the end portion 5b of the coil conductor 5. In the following description, the bulk layer 28 is referred to as the fourth bulk layer. Figure 3 Figure 10 As shown, a pair of bottom surface electrodes 3, 4 (terminal electrodes) are provided in the bulk layer 29. From the viewpoint of the manufacturing sequence, the bulk layer 29 is positioned on the uppermost side of the bulk 2, and constitutes the main surface 2d. In other words, the pair of bottom surface electrodes 3, 4 are provided on the main surface 2d of the bulk 2. In the following description, the bulk layer 29 is referred to as the fifth bulk layer. The pair of bottom surface electrodes 3, 4 each have a rectangular shape as viewed from the third direction D3. The pair of bottom surface electrodes 3, 4 can also have the same shape and the same size. The pair of bottom surface electrodes 3, 4 according to the present embodiment are arranged in the first direction Dl, and the bottom surface electrode 3 on the end surface 2a side of the bulk 2 overlaps the wiring portion 8f on the end surface 2a side and the side surface 2f side of the pair of wiring portions 8f of the bulk layer 28, and the bottom surface electrode 4 on the end surface 2b side of the bulk 2 overlaps the wiring portion 8f on the end surface 2b side and the side surface 2e side of the pair of wiring portions 8f of the bulk layer 28. The pair of bottom surface electrodes 3, 4 are embedded in the interior of the bulk 2 (more specifically, the interior of the bulk layer 29), and are exposed from the main surface 2d. The pair of bottom surface electrodes 3, 4 can also have a part or all of them provided on the main surface 2d of the bulk 2.

[0043] The coil component 1 can be manufactured by the manufacturing method shown in the flowchart of Figure 11 .

[0044] First, as a first step S1, the first bulk layer 22 is laminated on the bulk layer 21. Specifically, a plurality of second wiring portions 6 are formed on the bulk layer 21, and then the second wiring portions 6 are embedded by a resin material constituting the first bulk layer 22. More specifically, prescribed resist partition walls are provided on the bulk layer 21, and after the main body portions 9 are formed by electroplating using the adhesion layer 10 as a seed layer between the partition walls, the resist partition walls are removed, thereby obtaining the second wiring portions 6.

[0045] Next, as a second step S2, the second bulk layers 23 to 26 are sequentially laminated on the first bulk layer 22. In the case where the second bulk layers 23 to 26 are multiple layers as in the present embodiment, the second step S2 is repeated a plurality of times. That is, in the case where the number of the second bulk layers is N, the second step S2 is repeated N times. In the case where the second bulk layer is a single layer, the second step S2 is performed only once, and does not need to be repeated. ​

[0046] Then, as the third step S3, a third substrate layer 27 is laminated on the second substrate layers 23-26 (specifically, on the uppermost second substrate layer 26). Specifically, a plurality of first wiring portions 7 and a pair of wiring portions 8e are formed on the second substrate layer 26, and then the first wiring portions 7 and wiring portions 8e are embedded in the resin material constituting the third substrate layer 27. The first wiring portions 7 are obtained as follows: a predetermined resist partition wall is provided on the second substrate layer 26, and the main body portion 9 is formed between the partition walls by electroplating the close-fitting layer 10 as a seed layer, and then the resist partition wall is removed.

[0047] Then, as the fourth step S4, a fourth substrate layer 28 is stacked on the third substrate layer 27. Finally, as the fifth step S5, a fifth substrate layer 29 is stacked on the fourth substrate layer 28. The bottom electrodes 3 and 4 can be pre-positioned on the fifth substrate layer 29 before stacking, or they can be positioned on the fifth substrate layer 29 after stacking.

[0048] Next, refer to Figure 1 , 2 Sections 1 and 12 will describe the support section 8 of this embodiment.

[0049] In this embodiment, the support column 8 is formed by stacking the wiring columns 8a to 8d of each of the base layers 23 to 26. The support column 8 is composed of multiple pairs arranged in pairs along the first direction D1, and in this embodiment, it is composed of five pairs. Similar to the wiring columns 8a to 8d, the five pairs of support columns 8 are neatly arranged along the second direction D2 as two columns: a first column 8A and a second column 8B.

[0050] like Figure 12 As shown, the support portion 8 is connected to both ends 6a and 6b of the second wiring portion 6. Specifically, end 6a of the second wiring portion 6 is connected to one end of the support portion 8 (the end on the main surface 2c side), and end 6b of the second wiring portion 6 is also connected to one end of the support portion 8. The support portion 8 extends from both ends 6a and 6b of the second wiring portion 6 toward the main surface 2d of the body 2. In other words, one second wiring portion 6 is mounted on two support portions 8.

[0051] In this embodiment, one end of the first support portion 8 from the side 2f of the first column 8A is connected to the end 6a of the first second wiring portion 6 from the side 2f, and the other end is connected to the bottom electrode 3 disposed on the main surface 2d via wiring portions 8e and 8f constituting the end 5a of the coil conductor 5. One end of the second to fifth support portions 8 from the side 2f of the first column 8A is connected to the end 6a of the second to fifth second wiring portions 6 from the side 2f, respectively, and the other end is connected to the first end 7a of the first to fourth first wiring portions 7 from the side 2f, respectively.

[0052] In addition, in the present embodiment, one end portion of the first to fourth leg portions 8 of the second column 8B counted from the side surface 2f side is connected to the end portion 6b of the first to fourth second wiring portions 6 counted from the side surface 2f side, and the other end portion is connected to the second end portion 7b of the first to fourth first wiring portions 7 counted from the side surface 2f side. One end portion of the fifth leg portion 8 of the second column 8B counted from the side surface 2f side is connected to the end portion 6b of the fifth second wiring portion 6 counted from the side surface 2f side, and the other end portion is connected to the bottom surface electrode 4 provided on the main surface 2d via the wiring portions 8e, 8f provided on the end portion 5b of the coil conductor 5.

[0053] Here, when the above-described coil member 1 is applied to a high frequency circuit, due to the skin effect, a high frequency current flows concentratedly near the surfaces of the wiring portions 6, 7, and in the cross sections of the wiring portions 6, 7, the high frequency current flows concentratedly near the outer edges. Therefore, by reducing the resistance of the outer edges in the cross sections of the wiring portions 6, 7, the resistance of the wiring portions 6, 7 can be effectively reduced. Figure 5 8 In the cross sections of the wiring portions 6, 7 shown in FIG. 6, the high frequency current flows concentratedly near the outer edges. Therefore, by reducing the resistance of the outer edges in the cross sections of the wiring portions 6, 7, the resistance of the wiring portions 6, 7 can be effectively reduced.

[0054] In the present embodiment, the resistivity of the material (i.e., Cr) constituting the adhesion layer 10 is higher than the resistivity of the material (i.e., Cu) constituting the main body portion 9. Therefore, as described above, by designing the second direction length Wl of the adhesion layer 10 to be shorter than the second direction length W2 of the main body portion 9, and by the presence of the first region Rl where the adhesion layer 10 directly contacts the bulk layer 21, 26 (first insulating layer) and the second region R2 where the main body portion 9 directly contacts the bulk layer 21, 26, reduction of the resistance of the outer edges in the cross sections of the wiring portions 6, 7 is achieved. In the coil member 1, by achieving reduction of the resistance in the wiring portions 6, 7, a high self-resonance frequency is achieved.

[0055] In addition, as shown in FIG. 6, the corner portions 6k, 7k of the wiring portions 6, 7 which contact the bulk layer 21, 26 are constituted by the main body portion 9, and the resistance of the corner portions 6k, 7k is reduced as compared to the case where the corner portions 6k, 7k are constituted by the adhesion layer 10. Due to the skin effect, in particular, a high frequency current is concentrated in such corner portions 6k, 7k, and therefore, by constituting the corner portions 6k, 7k by the main body portion 9 constituted by a material having a lower resistivity, further reduction of the resistance in the wiring portions 6, 7 is achieved. Figure 5 8 In addition, as shown in FIG. 6, the corner portions 6k, 7k of the wiring portions 6, 7 which contact the bulk layer 21, 26 are constituted by the main body portion 9, and the resistance of the corner portions 6k, 7k is reduced as compared to the case where the corner portions 6k, 7k are constituted by the adhesion layer 10. Due to the skin effect, in particular, a high frequency current is concentrated in such corner portions 6k, 7k, and therefore, by constituting the corner portions 6k, 7k by the main body portion 9 constituted by a material having a lower resistivity, further reduction of the resistance in the wiring portions 6, 7 is achieved.

[0056] ​​Further, the first region R1 and the second region R2 are not limited to the above-described manner, and various modifications can be made. For example, the first region R1 can be configured to be equidistant from the pair of corners 6k, 7k, or can be disposed closer to one corner 6k, 7k. In this case, it can also be a manner in which one corner 6k, 7k is formed of the adhesion layer 10, and only the other corner 6k, 7k is formed of the main body portion 9. In the cross section of each wiring portion 6, 7, the first region R1 can be one, or can be a plurality. Similarly, in the cross section of each wiring portion 6, 7, the second region R2 can be one, or can be a plurality.

[0057] The present application is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the spirit thereof.

[0058] For example, the structure in which the first region and the second region exist does not necessarily need to have both the first wiring portion 7 and the second wiring portion 6, and can be a manner in which only either one of the first wiring portion 7 and the second wiring portion 6 is provided.

Claims

1. A coil component, wherein, have: The base body, which consists of multiple stacked insulating layers; and A coil conductor is disposed within the body and includes a wiring portion extending in a direction orthogonal to the stacking direction of the body and overlapping with a first insulating layer of the plurality of insulating layers in the stacking direction. The wiring portion has a main body and a bonding layer disposed on a portion of the interface between the main body and the first insulating layer in a cross section orthogonal to the extension direction. There is a first region where the bonding layer is directly in contact with the first insulating layer and a second region where the main body is directly in contact with the first insulating layer.

2. The coil component according to claim 1, wherein, The resistivity of the close-fitting layer of the wiring section is higher than that of the main body section.

3. The coil component according to claim 1 or 2, wherein, The wiring portion has a pair of corner portions in a cross section orthogonal to the extension direction, which are connected to the first insulating layer, and each of the two corner portions is composed of the main body portion.

4. The coil component according to any one of claims 1 to 3, wherein, The insulating layer constituting the substrate is made of resin.

5. The coil component according to any one of claims 1 to 4, wherein, The bonding layer of the wiring section is made of Cr.

6. The coil component according to any one of claims 1 to 5, wherein, The main body of the wiring section is made of Cu.

7. The coil component according to any one of claims 1 to 6, wherein, The substrate has a mounting surface orthogonal to the stacking direction. The coil conductor includes a plurality of first wiring portions extending parallel to the mounting surface, a plurality of second wiring portions extending parallel to the mounting surface at a distance farther from the mounting surface than the first wiring portions, and a plurality of pairs of support portions extending from both ends of each of the plurality of second wiring portions toward the mounting surface along the stacking direction. The wiring section is the second wiring section.

Images