Coil component and method of manufacturing the same

Abstract

The present invention relates to a coil component and a manufacturing method thereof, and an inductor wiring conductor (19) is configured such that, when viewed in a cross section of the inductor wiring conductor (19) in a direction orthogonal to an extending direction, a height direction dimension (Hc) of a central portion of a top surface (25) is smaller than a height direction dimension (He) of an end portion of the top surface (25) in terms of a height direction dimension linking between the top surface (25) and a bottom surface (26).

Description

Technical Field

[0001] The disclosure relates to a coil component formed by incorporating a linear inductive wiring conductor within a body, and a method for manufacturing the same, particularly to a coil component having an inductive wiring conductor covered by a resin-containing layer, and a method for manufacturing the same. Background Technology

[0002] Patent Document 1 describes a case where an insulating resin layer covers a spirally extending linear inductive wiring conductor. Patent Document 1 illustrates a flat outer surface of the insulating resin layer.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2014-13815

[0004] However, in reality, for example Figure 27 As shown, on the outer surface of the insulating resin layer 2 covering the inductor wiring conductor 1, a convex surface 3 is locally formed to mimic the shape of the inductor wiring conductor 1.

[0005] Reference Figure 27 The inductive wiring conductor 1 is disposed on a substrate 4 made of an electrically insulating material. The inductive wiring conductor 1 is formed, for example, by electroplating. In order to supply charge during the electroplating process, a conductive seed layer (not shown) is formed on the substrate 4, and a plating material is grown on the seed layer, thereby forming the inductive wiring conductor 1. Therefore, the inductive wiring conductor 1 is in a state of partially protruding from the surface of the substrate 4.

[0006] Therefore, when an insulating resin layer 2 is provided to cover the inductive wiring conductor 1, a convex surface 3 mimicking the shape of the inductive wiring conductor 1 is formed on the outer surface of the insulating resin layer 2. More specifically, the top of the convex surface 3 is located directly above the center of the inductive wiring conductor 1 in the width direction. According to the inventor's research, the height H1 of the inductive wiring conductor 1 is, for example, 50 μm to 100 μm, but the height H2 from the bottom of the concave surface to the top of the convex surface 3 is about 20% of the height H1 of the inductive wiring conductor 1. Furthermore, in Figure 27 The height H2 of the top of convex surface 3 is shown in the slightly exaggerated illustration.

[0007] It is desirable that the height H2 of the top of the convex surface 3 of the aforementioned insulating resin layer 2 be as small as possible. This is because the convex surface 3 not only detracts from the product's aesthetics but also leads to instability in the installation posture. To eliminate the convex surface 3, additional treatments such as grinding for planarization are sometimes implemented; however, the smaller the height H2 of the top of the convex surface 3, the easier the additional treatment is, thereby reducing the cost of such treatments. Summary of the Invention

[0008] Therefore, the purpose of this disclosure is to provide a structure and a method for manufacturing a coil component that can further improve the flatness of a resin-containing surface, such as an insulating resin layer covering the inductive wiring conductor.

[0009] The coil component disclosed herein comprises: a linear inductive wiring conductor having a top surface and a bottom surface opposite to each other, a first side surface and a second side surface connecting the top surface and the bottom surface and opposite to each other; and a resin layer covering at least the top surface, the first side surface and the second side surface of the inductive wiring conductor.

[0010] In the aforementioned coil component, the inductor wiring conductor is configured such that, when viewed in a cross-section of the inductor wiring conductor in a direction orthogonal to the extension direction, the central portion of the top surface is smaller than the end portion of the top surface in terms of the height dimension connecting the top and bottom surfaces.

[0011] The method for manufacturing a coil component disclosed herein includes: a step of preparing a support substrate; a step of forming an inductor wire conductor with a linear inductor wire conductor supported on the support substrate, the inductor wire conductor having a top surface and a bottom surface facing each other, a first side surface and a second side surface connecting the top surface and the bottom surface and facing each other; a step of providing a resin-containing layer covering at least the top surface, the first side surface and the second side surface of the inductor wire conductor; and a step of removing the support substrate.

[0012] In the above-mentioned method for manufacturing coil components,

[0013] The process of forming an inductive wiring conductor includes: when viewed in a cross section of the inductive wiring conductor in a direction orthogonal to the extension direction, the central portion of the top surface is smaller than the end portion of the top surface in terms of the height dimension connecting the top and bottom surfaces.

[0014] According to the coil component of this disclosure, the resin-containing layer, which is provided to cover the inductor wiring conductor, tends to be recessed directly above the center in the width direction of the inductor wiring conductor. As a result, the height of the surface convexity that would occur if the resin-containing layer were simply provided to cover the inductor wiring conductor is offset.

[0015] Therefore, the height difference between concave and convex portions on the surface of the resin-containing layer can be reduced, thereby improving flatness. This improves the product's aesthetics and stabilizes the installation posture, and makes additional processing for eliminating convex surfaces easier or unnecessary, thus reducing the cost of such processing. Attached Figure Description

[0016] Figure 1 This is a top view showing the appearance of the magnetic resin layer of the coil component.

[0017] Figure 2 It is an enlarged representation Figure 1 The portion of the coil component shown and along Figure 1 A sectional view of line AA.

[0018] Figure 3 It is used for Figure 1 A cross-sectional view illustrating the manufacturing method of the coil component is shown, and a portion of the prepared support substrate 35 is also shown.

[0019] Figure 4 It means Figure 3 The diagram shows a cross-sectional view of the process immediately following the shown process, and shows the state in which the base layer 36 is formed on the support substrate 35.

[0020] Figure 5 It means Figure 4 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which a seed layer 38 is formed on the base layer 36.

[0021] Figure 6 It means Figure 5 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which the resist 39 is applied to the seed layer 38.

[0022] Figure 7 It means Figure 6 The diagram shows a cross-sectional view of the process immediately following the previous one, and illustrates the state in which an inductive wiring conductor 19 is formed on the seed layer 38 by electroplating and through the opening 40 of the resist 39.

[0023] Figure 8 It means Figure 7 The diagram shows a cross-sectional view of the process immediately following the previous one, indicating the state after the removal of resist 39.

[0024] Figure 9 It means Figure 8 The diagram shows a cross-sectional view of the process immediately following the shown process, indicating the state after the excess portion of the seed layer 38 has been removed.

[0025] Figure 10 It means Figure 9 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which an insulating resin layer 29 is provided in such a way as an inductive wiring conductor 19.

[0026] Figure 11 It means Figure 10 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which a first magnetic resin layer 31 is formed to cover the insulating resin layer 29.

[0027] Figure 12 It means Figure 11The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which parts of the support substrate 35 and the base layer 36 have been removed.

[0028] Figure 13 It means Figure 12 The diagram shows a cross-sectional view of the process immediately following the shown process, indicating that the coil component is completed with the second magnetic resin layer 32 in partial contact with the insulating resin layer 29 and the base layer 36.

[0029] Figure 14 It is a cross-sectional view used to illustrate the manufacturing method of the coil component and shows a portion of the prepared support substrate 35.

[0030] Figure 15 It means Figure 14 The diagram shows a cross-sectional view of the process immediately following the shown process, and shows the state in which the base layer 36a is formed on the support substrate 35.

[0031] Figure 16 It means Figure 15 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which a seed layer 38 is formed on the base layer 36a.

[0032] Figure 17 It means Figure 16 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which the resist 39 is applied to the seed layer 38.

[0033] Figure 18 It means Figure 17 The diagram shows a cross-sectional view of the process immediately following the shown process, and illustrates the state in which an inductive wiring conductor 19 is formed on the seed layer 38 by electroplating through the opening 40 of the resist 39.

[0034] Figure 19 It means Figure 18 The diagram shows a cross-sectional view of the process immediately following the previous one, indicating the state after the removal of resist 39.

[0035] Figure 20 It means Figure 19 The diagram shows a cross-sectional view of the process immediately following the shown process, indicating the state after the excess portion of the seed layer 38 has been removed.

[0036] Figure 21 It means Figure 20 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which an insulating resin layer 29 is provided in such a way as an inductive wiring conductor 19.

[0037] Figure 22 It means Figure 21 The diagram shows a cross-sectional view of the process immediately following the shown process, and illustrates the state in which the first magnetic resin layer 31 is formed to cover the insulating resin layer 29.

[0038] Figure 23 It means Figure 22 The diagram shows a cross-sectional view of the process immediately following the shown process, and indicates the state in which parts of the support substrate 35 and the base layer 36a have been removed.

[0039] Figure 24 It means Figure 23 The diagram shows a cross-sectional view of the process immediately following the shown process, indicating that the coil component is completed with the second magnetic resin layer 32 in partial contact with the insulating resin layer 29 and the base layer 36a.

[0040] Figure 25 This refers to the manufacturing method of coil components. Figure 7 The process is a cross-sectional view of the process and shows the state in which an inductive wiring conductor 19 is formed on the seed layer 38 by electroplating and through the opening 40 of the resist 39.

[0041] Figure 26 This refers to the manufacturing method of coil components. Figure 7 The process is a cross-sectional view of the process and shows the state in which an inductive wiring conductor 19 is formed on the seed layer 38 by electroplating and through the opening 40 of the resist 39.

[0042] Figure 27 It is a cross-sectional view showing that a convex surface 3 is formed on the outer surface of the insulating resin layer 2 covering the inductive wiring conductor 1.

[0043] Explanation of reference numerals in the attached figures:

[0044] 11, 11a…coil components; 19…inductor wiring conductor; 25…top surface; 26…bottom surface; 27, 28…side surfaces; 29…insulating resin; 31…first magnetic resin layer; 32…second magnetic resin layer; 38…seed layer; 38a, 38b…protrusions of the seed layer; 38c…groove of the seed layer; 39…resist; 40…opening; 43…plating bath; He…height dimension at both ends; Hc…height dimension at the center. Detailed Implementation

[0045] [First Implementation Method]

[0046] Reference Figure 1 and Figure 2 The structure of the coil component 11 in the first embodiment of the present invention will be described.

[0047] The coil component 11 includes a main body 12. The main body 12 is plate-shaped or cuboid-shaped and has a first main surface 13 and a second main surface 14 opposite each other, and four end faces 15, 16, 17, and 18 connecting the first main surface 13 and the second main surface 14. Furthermore, "main surface" and "end face" are names used for ease of explanation and are relatively defined locations. Therefore, for example, "main surface" is not limited to the largest face in a cube.

[0048] An inductive wiring conductor 19, for example, extending in a spiral shape, is disposed within the main body 12. The inductive wiring conductor 19 extends in a spiral shape in a plane parallel to the main surfaces 13 and 14. External terminal electrodes 21 and 22 are provided on the first main surface 13 of the main body 12. One end and the other end of the inductive wiring conductor 19 are electrically connected to the external terminal electrodes 21 and 22 by means of lead-out conductors 23 and 24, respectively.

[0049] The inductive wiring conductor 19 and the lead conductors 23 and 24 can be made of Au, Pt, Pd, Ag, Cu, Al, Co, Cr, Zn, Ni, Ti, W, Fe, Sn or In, or compounds thereof, but for the sake of good conductivity and low cost, Cu or Cu alloys are particularly preferred.

[0050] External terminal electrodes 21 and 22, for example, have a Cu electroless plating layer as a base layer that contacts the lead conductors 23 and 24, a Ni electroless plating layer on the Cu electroless plating layer, and an Au electroless plating layer on the Ni electroless plating layer.

[0051] Figure 2 This represents the cross-section of the inductive wiring conductor 19 in a direction orthogonal to its extension direction. (Refer to...) Figure 2 The inductive wiring conductor 19 has a top surface 25 and a bottom surface 26 facing each other, and a first side surface 27 and a second side surface 28 connecting the top surface 25 and the bottom surface 26 and facing each other. Furthermore, hereinafter, the first side surface 27 and the second side surface 28 will sometimes be collectively referred to as side surfaces 27 and 28. Figure 2 In this case, the top surface 25 is concave and curved. When the direction connecting the top surface 25 and the bottom surface 26 is taken as the height direction, the height dimension Hc of the central part of the top surface 25 is smaller than the height dimension He of the two ends of the top surface 25. That is, in terms of the height dimension, the central part of the top surface 25 is smaller than the ends of the top surface 25.

[0052] The main body 12 has an insulating resin layer 29 covering at least the top surface 25 and the side surfaces 27, 28 of the inductive wiring conductor 19. The insulating resin layer 29 is made of, for example, epoxy resin, acrylic resin, phenolic resin or polyimide, or a mixture thereof, and is an electrical insulator and a non-magnetic material.

[0053] The main body 12 also includes a first magnetic resin layer 31 and a second magnetic resin layer 32 covering the insulating resin layer 29. The magnetic resin layers 31 and 32 are composed of an organic material containing metallic magnetic powder. The metallic magnetic powder, for example, has an average particle size of 5 μm or less and is composed of an alloy containing Fe, such as an Fe-Si alloy. Furthermore, the metallic magnetic powder can be crystalline or amorphous. Alternatively, oxide magnetic powders such as ferrites can be used instead of metallic magnetic powder. As the organic material, for example, epoxy resin; a mixture of epoxy resin and acrylic resin; or a mixture of epoxy resin, acrylic resin, and other resins are used.

[0054] As described above, in the inductive wiring conductor 19, the top surface 25 is concave, and the height dimension Hc of the central portion of the top surface 25 is smaller than the height dimension He of the two ends of the top surface 25. Therefore, the insulating resin layer 29 covering the inductive wiring conductor 19 is applied in an active state along the concave direction directly above the center in the width direction of the inductive wiring conductor 19. As a result, as Figure 2 As shown, even if a convex surface is formed on the surface 29a of the insulating resin layer 29, the height H2 from the bottom of the concave surface to the top of the convex surface can be made small.

[0055] Furthermore, the surfaces of the magnetic resin layers 31 and 32 covering the insulating resin layer 29 mimic the surface 29a of the insulating resin layer 29, thus eliminating most of the unevenness. Therefore, the aesthetics of the coil component 11 as a product can be improved and the mounting posture can be stabilized. Moreover, the additional processing for eliminating convex surfaces can be made easier or eliminated, thereby reducing the cost of additional processing.

[0056] Furthermore, regarding the height dimension of the inductor wiring conductor 19 connecting the top surface 25 and the bottom surface 26, it is preferable that, when viewed from a cross-section of the inductor wiring conductor 19 in a direction orthogonal to the extension direction, the difference between the maximum and minimum values ​​of this height dimension is less than 20% of the maximum value. In this embodiment, the maximum value of the height dimension is the height dimension He at both ends, and the minimum value of the height dimension is the height dimension Hc at the center, thus forming a value such that (He-Hc) / He≤0.2. If this condition is met, the height dimension Hc at the center of the top surface 25 in the width direction can be reduced, thereby keeping the increase in the resistance value of the inductor wiring conductor 19 caused by reducing the cross-sectional area of ​​the inductor wiring conductor 19 within an acceptable range.

[0057] The difference between the maximum and minimum height dimension of the aforementioned inductive wiring conductor 19 should not be understood as the difference between the maximum and minimum values ​​obtained by measuring the height dimension at all cross-sections along the length of the inductive wiring conductor 19, but rather as the difference between the maximum and minimum values ​​measured at a specific cross-section of the inductive wiring conductor 19 in a direction orthogonal to the extension direction. This is because it is well known that if the difference is less than 20% at at least one cross-section, the increase in resistance is generally within an acceptable range. Furthermore, in actual measurement, it is desirable, for example, to use the cross-section of the main body 12 including the center point of the first main surface 13 as the aforementioned cross-section.

[0058] On the other hand, in order to achieve the aforementioned effect more reliably, in terms of the height dimension connecting the top surface 25 and the bottom surface 26 in the inductive wiring conductor 19, it is preferable that the difference between the maximum and minimum values ​​of the height dimension is more than 5% of the maximum value.

[0059] exist Figure 2 As will become clear from the following description of the manufacturing method, the component configured to contact the bottom surface 26 of the inductive wiring conductor 19 is a portion of the base layer 36 that holds the seed layer integrally formed with the inductive wiring conductor 19.

[0060] The insulating resin layer 29 and the magnetic resin layers 31 and 32 described above both contain resin, and are therefore collectively referred to as "resin-containing layers". In this embodiment, the resin-containing layer comprises an insulating resin layer 29 that forms a substrate and is in contact with the inductive wiring conductor 19, and magnetic resin layers 31 and 32 that cover the insulating resin layer 29. As another embodiment of this disclosure, the resin-containing layer may be an embodiment that only has an insulating resin layer and does not have a magnetic resin layer, or an embodiment that only has a magnetic resin layer and does not have an insulating resin layer.

[0061] The insulating resin layer 29, being non-magnetic due to the absence of magnetic material, contributes to improved electrical insulation between the inductor wiring conductor 19 and the exterior of the coil component 11, electrical insulation between adjacent turns of the inductor wiring conductor 19, and electrical insulation between the inductor wiring conductor 19 and the metallic magnetic powder in the magnetic resin layers 31 and 32. The magnetic resin layers 31 and 32 facilitate the formation of a magnetic circuit.

[0062] In this embodiment, the portion surrounding the inductive wiring conductor 19 and covering the top surface 25 and the portions covering the side surfaces 27, 28 are formed of a series of insulating resin layers 29. That is, the portions covering the top surface 25 and the portions covering the side surfaces 27, 28, which contain resin layers, are made of the same material integrally. According to this structure, the mechanical strength of the insulating resin layer 29 surrounding the inductive wiring conductor 19 relative to shear stress can be improved, thereby making it less likely for the insulating resin layer 29 to peel off and for electrical short circuits to occur between the inductive wiring conductor 19 and the metallic magnetic powder in the magnetic resin layers 31, 32.

[0063] In addition, Figure 2 The text shows along Figure 1 The cross section of line AA, but Figure 2 All of the inductive wiring conductors 19 shown satisfy the following condition: when viewed in a cross-section of the inductive wiring conductor 19 in a direction orthogonal to the extension direction, the height dimension of the central portion of the top surface 25 is smaller than the height dimension of the two ends of the top surface 25 in terms of the height dimension connecting the top surface 25 and the bottom surface 26. However, this condition may not be satisfied throughout the entire length of the inductive wiring conductor.

[0064] Next, refer to Figures 3 to 13 A preferred manufacturing method for the coil component 11 will be described. Figures 3 to 13 The diagram shows the settings. Figure 2 The manufacturing method of the inductive wiring conductor 19 shown is partially related to this method.

[0065] First, such as Figure 3 As shown, a support substrate 35 is prepared. The support substrate 35 is made of a material with high flexural strength, such as ceramic or resin.

[0066] Next, as Figure 4 As shown, a base layer 36 is provided on the support substrate 35. The base layer 36 is used to hold the seed layer 38 (described later) in a desired shape, and the base layer 36 is made of, for example, resin. The base layer 36 has protrusions 37.

[0067] Next, as Figure 5As shown, a conductive seed layer 38 is formed on the support substrate 35. In this embodiment, the seed layer 38 is formed on the support substrate 35 across a base layer 36 formed on the support substrate 35. The seed layer 38 may also be formed directly on the support substrate 35, on a base layer 36 as described above, or on an insulating layer formed on the support substrate 35. The seed layer 38 is used to supply charge when the inductive wiring conductor 19 is formed by electroplating. The seed layer 38 is preferably made of the same material as the inductive wiring conductor 19, such as Au, Pt, Pd, Ag, Cu, Al, Co, Cr, Zn, Ni, Ti, W, Fe, Sn, or In, or compounds thereof.

[0068] Furthermore, for the purpose of forming the inductive wiring conductor 19, the seed layer 38 is preferably made of the same material as the inductive wiring conductor 19, as described above. However, if the inductive wiring conductor 19 is a material such as Cu with weak adhesion to the base layer 36, which is the resin, the seed layer 38 is preferably made of a material such as Ti with strong adhesion to the resin. Moreover, the seed layer 38 is more preferably a multilayer structure consisting of a layer made of a material with strong adhesion to the resin and a layer made of the same material as the inductive wiring conductor 19.

[0069] To form the seed layer 38, methods such as electroless plating, sputtering, or laminating copper foil using thin adhesive sheets are employed. Furthermore, as long as the charge can be supplied and the function can be fully utilized during the electroplating process, the thickness of the seed layer 38 is not particularly limited, but for example, it is desirable to be less than 2 μm.

[0070] Next, as Figure 6 As shown, resist 39 is disposed on seed layer 38. Resist 39 has openings 40 corresponding to the pattern of inductive wiring conductor 19. Resist 39 is formed, for example, from dry film resist. More specifically, dry film resist is laminated onto seed layer 38 while peeling off protective film, and patterned through exposure, development, and curing processes, thereby forming resist 39 with openings 40.

[0071] Next, as Figure 7 As shown, the inductive wiring conductor 19 is formed, for example, by electroplating a conductive metal such as Cu. The conductive metal that should become the inductive wiring conductor 19 is deposited and grown on a seed layer 38 that has been supplied with charge through an opening 40 in the resist 39, thereby becoming the inductive wiring conductor 19. When the seed layer 38 is made of the same material as the inductive wiring conductor 19, the inductive wiring conductor 19 and the seed layer 38 are formed as one.

[0072] In the aforementioned electroplating process, by adjusting the concentration of additives in the plating bath used for electroplating, a shape is obtained in the inductive wiring conductor 19 such that the height dimension of the central portion of the top surface 25 is smaller than the height dimension of the two ends of the top surface 25 in terms of the height dimension connecting the top surface 25 and the bottom surface 26. More specifically, for example, an operation is performed to increase the concentration of leveling additives and decrease the concentration of brightening additives.

[0073] Next, as Figure 8 As shown, the resist 39 is removed by peeling.

[0074] Next, in Figure 8 Perform wet etching under the conditions shown, such as Figure 9 As shown, the excess portion of the seed layer 38 is removed, that is, the portion of the seed layer 38 exposed from the inductor wiring conductor 19 is removed.

[0075] Next, as Figure 10 As shown, an insulating resin layer 29, which forms part of the main body 12, is provided on the base layer 36, and the inductive wiring conductor 19 is located inside it. The insulating resin layer 29 is formed, for example, by applying resin paste using a spin coating method. At this time, if necessary, by performing a vacuum, the generation of air bubbles (bubbling) can be suppressed, and the resin paste can be smoothly filled into narrow spaces.

[0076] like Figure 10 As shown, the insulating resin layer 29, which is applied to cover the inductive wiring conductor 19, is in an active state along the concave direction directly above the center of the top surface 25 of the inductive wiring conductor 19 in the width direction. As a result, the height of the protrusion of the surface 29a, which would occur when the insulating resin layer 29 is simply configured to cover an inductive wiring conductor whose top surface is not concave, is reduced due to the aforementioned active state along the concave direction in the insulating resin layer 29.

[0077] Although not illustrated, the insulating resin layer 29 can then be patterned as needed. For example, in cases where an insulating resin layer is provided for each of multiple inductor conductors, or for each of multiple turns of an inductor conductor, the insulating resin layer is patterned after being uniformly covering the substrate layer. In this case, if a photosensitive resin is used as the resin for the insulating resin layer 29, photolithography can be used to leave resin only in the necessary areas, thereby enabling patterning. If a non-photosensitive resin is used, excess resin can be removed by UV laser or drilling if patterning is required.

[0078] As the resin constituting the insulating resin layer 29, it is preferable to use a resin that can achieve a high degree of adhesion between itself and the resin constituting the base layer 36. This reduces the risk of peeling between the insulating resin layer 29 and the base layer 36.

[0079] Next, as Figure 11 As shown, a first magnetic resin layer 31, composed of an organic material containing metallic magnetic powder, is provided, and the first magnetic resin layer 31 covers the insulating resin layer 29. The first magnetic resin layer 31 is obtained, for example, by stamping a sheet composed of an organic material containing metallic magnetic powder. Figure 11 The state shown is then formed through curing.

[0080] Next, as Figure 12 As shown, the support substrate 35 is removed, and a portion of the base layer 36 is also removed. Figure 12 In the middle, the protrusion 37 of the base layer 36 remains. In addition, for the base layer 36, even if the base layer 36 is not removed and remains as is, it is possible to reduce the risk of partially removing the inductor wiring conductor 19 due to the desire to completely remove the base layer 36, provided that the base layer 36 is left as is and does not cause particular obstruction.

[0081] Next, as Figure 13 As shown, a second magnetic resin layer 32, composed of an organic material containing metallic magnetic powder, is provided, such that the second magnetic resin layer 32 makes partial contact with the insulating resin layer 29 and the base layer 36. The second magnetic resin layer 32 is obtained, for example, by stamping a sheet composed of an organic material containing metallic magnetic powder. Figure 13 The state shown is then formed by curing. The main body 12 is formed by the second magnetic resin layer 32, the aforementioned insulating resin layer 29, and the first magnetic resin layer 31.

[0082] Figure 13 The state shown is equivalent to Figure 2 The state shown.

[0083] In addition to the above-mentioned steps, the steps of setting out lead conductors 23 and 24 are performed in parallel with the above-mentioned steps, and the steps of setting out external terminal electrodes 21 and 22 are performed, thereby completing the coil component 11.

[0084] In this way, although coil components 11 are manufactured, if multiple coil components 11 are manufactured simultaneously in the form of a base material for the above-mentioned process, a process of cutting the assembly of coil components 11 in the form of the base material by, for example, a cutting machine can be performed later.

[0085] [Second Implementation]

[0086] Figures 14-24This is a cross-sectional view used to illustrate the manufacturing method of the coil component 11a according to the second embodiment of the disclosed invention. Figures 14-24 In China, for the sake of Figures 1 to 13 The components shown are labeled with the same reference numerals as those in the accompanying drawings, and repeated descriptions are omitted.

[0087] The coil component 11a, as a finished product in the second embodiment, is constructed as follows: Figure 24 As shown. Hereinafter, a preferred manufacturing method for coil component 11a will be described.

[0088] First, as in the first embodiment, such as Figure 14 As shown, prepare the support substrate 35.

[0089] Next, as Figure 15 As shown, a base layer 36a is provided on the support substrate 35. The base layer 36a has, for example, a shape in which a groove 37c is formed between two protrusions 37a and 37b by means of photolithography or the like, coated with a photosensitive resin.

[0090] Alternatively, the base layer 36a can be omitted, and the protrusions 37a, 37b, and grooves 37c can be directly machined on the support substrate 35 itself. In this case, only mechanical processing such as cutting, dry processes such as sandblasting, and wet processes using local solvents to dissolve the support substrate 35 are required.

[0091] Next, as Figure 16 As shown, a conductive seed layer 38 is formed on the base layer 36a. The seed layer 38 is formed along the upper surface of the base layer 36a and has protrusions 38a, 38b and grooves 38c that respectively mimic the shapes of protrusions 37a, 37b and grooves 37c of the base layer 36a.

[0092] Next, as Figure 17 As shown, resist 39 is disposed on seed layer 38. Resist 39 has an opening 40 with a pattern corresponding to the pattern of inductive wiring conductor 19. The protrusions 38a and 38b of the seed layer 38 are located at the ends of the opening 40 in the width direction.

[0093] Next, as Figure 18 As shown, the inductive wiring conductor 19 is formed, for example, by electroplating a conductive metal such as Cu. The conductive metal that should become the inductive wiring conductor 19 is deposited and grown on the seed layer 38, which is supplied with charge, through the opening 40 of the resist 39, thereby becoming the inductive wiring conductor 19. The inductive wiring conductor 19 is formed integrally with the seed layer 38.

[0094] In the aforementioned electroplating process, plating growth occurs on the seed layer 38, but the protrusions 38a and 38b in the seed layer 38 are located at a higher position compared to the grooves 38c in the seed layer 38. That is, the portions in the seed layer 38 corresponding to the two ends of the top surface 25 of the inductive wiring conductor 19 are more prominent than the portions in the seed layer 38 corresponding to the center of the top surface 25. Therefore, in the formed inductive wiring conductor 19, in terms of the height dimension connecting the top surface 25 and the bottom surface 26, it is possible to obtain a shape in which the height dimension of the center of the top surface 25 is smaller than the height dimension of the two ends of the top surface 25.

[0095] Next, as Figure 19 As shown, the resist 39 is removed by peeling.

[0096] Next, in Figure 19 Perform wet etching under the conditions shown, such as Figure 20 As shown, the excess portion of the seed layer 38 is removed, that is, the portion of the seed layer 38 exposed from the inductor wiring conductor 19 is removed.

[0097] Next, as Figure 21 As shown, an insulating resin layer 29, which forms part of the main body 12, is provided on the base layer 36a, with the inductor wiring conductor 19 located inside. The insulating resin layer 29, which is provided to cover the inductor wiring conductor 19, is applied in a recessed direction directly above the center of the top surface 25 of the inductor wiring conductor 19 in the width direction. As a result, the height of the protrusion of the surface 29a, which would occur if the insulating resin layer 29 were simply set to cover the inductor wiring conductor 19, is reduced due to the aforementioned recessed direction movement of the insulating resin layer 29.

[0098] Although not illustrated, the insulating resin layer 29 can then be patterned as needed.

[0099] Next, as Figure 22 As shown, a first magnetic resin layer 31 is provided, which covers an insulating resin layer 29.

[0100] Next, as Figure 23 As shown, the support substrate 35 is removed, and a portion of the base layer 36a is also removed. Furthermore, even if the base layer 36a is not removed and remains as is, the risk of partially removing the inductor wiring conductor 19 due to the intention to completely remove the base layer 36a can be reduced, provided that it does not cause particular obstruction.

[0101] Next, as Figure 24As shown, a second magnetic resin layer 32, composed of an organic material containing metallic magnetic powder, is provided, making partial contact between the second magnetic resin layer 32 and the insulating resin layer 29 and the base layer 36a. The main body 12 is formed by the second magnetic resin layer 32, the aforementioned insulating resin layer 29, and the first magnetic resin layer 31.

[0102] Figure 24 This refers to the coil component 11a as a finished product. In the coil component 11a, compared with the coil component 11 described above, the contact area between the inductor wiring conductor 19 and the base layer 36a is increased, thus improving the tight adhesion between the inductor wiring conductor 19 and the base layer 36a, thereby improving the resistance to thermal stress and the like.

[0103] [Third Implementation Method]

[0104] Figure 25 This refers to the preferred manufacturing method of the coil component in the third embodiment of the disclosed invention, which is similar to the one described above. Figure 7 The process is a cross-sectional view of the corresponding process. Figure 25 In China, for the sake of Figure 7 The components shown are labeled with the same reference numerals as those in the accompanying drawings, and repeated descriptions are omitted.

[0105] exist Figure 25 The diagram shows a state where an inductive wiring conductor 19 is formed on a seed layer 38 via an opening 40 in the resist 39 through electroplating. During the electroplating process, a flow 44 is generated in the plating bath 43 used for electroplating, parallel to the main surface of the support substrate 35 and orthogonal to the extension direction of the inductive wiring conductor 19 to be formed. This flow in the plating bath 43 can be generated, for example, using a jet plating apparatus.

[0106] The flow in the direction of arrow 44 creates a liquid flow that penetrates deep into the opening 40 of the resist 39, as indicated by the curved arrow 45. Therefore, plating is preferentially deposited at both ends of the top surface 25 of the inductor conductor 19 to be formed. As a result, an inductor conductor 19 is obtained where the height dimension of the central portion of the top surface 25 is lower than the height dimension of the two ends of the top surface 25.

[0107] [Fourth Implementation Method]

[0108] Figure 26 This refers to the preferred manufacturing method of the coil component in the fourth embodiment of the disclosed invention, which is consistent with the foregoing. Figure 7 The process is a cross-sectional view of the corresponding process. Figure 26 In China, for the sake of Figure 7 The components shown are labeled with the same reference numerals as those in the accompanying drawings, and repeated descriptions are omitted.

[0109] exist Figure 26 The diagram shows a state where an inductive wiring conductor 19 is formed on a seed layer 38 via an opening 40 in the resist 39 through electroplating. In the electroplating process, the seed layer 38 is made smaller than the width of the opening 40 in the resist 39, and the seed layer 38 is positioned biased towards the width direction of the opening 40. Therefore, plating is preferentially performed at the ends of the top surface 25 of the inductive wiring conductor 19 to be formed. As a result, an inductive wiring conductor 19 is obtained where the height dimension of the central portion of the top surface 25 is lower than the height dimension of the two ends of the top surface 25. In this case, the seed layer 38 can be formed simply by a subtractive method (a method of patterning the seed layer with a photoresist after forming a seed layer over the entire surface and before electroplating).

[0110] Furthermore, in the third and fourth embodiments described above, the top surface 25 of the inductive wiring conductor 19 is asymmetrical. Therefore, the lowest point of the top surface 25 is not located at the center of the top surface 25 in the width direction, and the heights at one end and the other end of the top surface 25 in the width direction are different. However, the central portion of the top surface 25 is lower than both ends of the top surface 25. Thus, in terms of the height dimension connecting the top surface 25 and the bottom surface 26, the condition that the height dimension of the central portion of the top surface 25 is smaller than the height dimension of both ends of the top surface 25 is satisfied.

[0111] The above description illustrates several embodiments of the disclosure, but various other modifications are possible within the scope of this disclosure.

[0112] For example, the extension state and quantity of inductor wiring conductors in the coil component can be arbitrarily changed according to the design. Inductor wiring conductors can also extend in a straight line or a meandering shape, for example.

[0113] Furthermore, in this disclosure, regardless of the method of forming the inductive wiring conductor, in addition to the aforementioned electroplating method, chemical plating, sputtering, vapor deposition, printing, etc., may also be applied.

[0114] In addition, in the inductive wiring conductor, in terms of the height dimension connecting the top and bottom surfaces, the height dimension of the central part of the top surface is smaller than the height dimension of the two ends of the top surface. Therefore, after the inductive wiring conductor is temporarily formed, subsequent processing such as machining can be performed.

[0115] Furthermore, the embodiments described in this specification are illustrative structures, and partial substitutions or combinations of structures can be made between different embodiments.

Claims

1. A coil component, wherein, Possessing: a linear inductor wiring conductor having mutually opposed top and bottom surfaces, first and second side surfaces connecting and opposing each other between the top and bottom surfaces; and a resin-containing layer covering at least the top surface, the first side surface, and the second side surface of the inductor wiring conductor, the inductor wiring conductor is configured such that, when viewed in a cross section of the inductor wiring conductor in a direction orthogonal to an extending direction, a central portion of the top surface is smaller than end portions of the top surface in terms of a height direction dimension connecting between the top and bottom surfaces, the resin-containing layer is a series of resin-containing layers, and is formed in one operation after formation of the inductor wiring conductor such that the portion covering the top surface of the inductor wiring conductor and the portion covering the first and second side surfaces of the inductor wiring conductor are formed from a material composed of the same material in one body, and the resin-containing layer is in contact with the top surface, the first side surface, and the second side surface.

2. The coil member according to claim 1, wherein the resin-containing layer includes an electrically insulating body and a non-magnetic, insulating resin layer.

3. The coil member according to claim 1, wherein the resin-containing layer includes a magnetic resin layer composed of an organic material containing a metal magnetic powder.

4. The coil member according to claim 1, wherein the resin-containing layer includes an electrically insulating body and a non-magnetic, insulating resin layer in contact with the inductor wiring conductor, and a magnetic resin layer composed of an organic material containing a metal magnetic powder covering the insulating resin layer.

5. The coil member according to any one of claims 1 to 4, wherein a plurality of the inductor wiring conductors are present, all of the plurality of the inductor wiring conductors are configured such that, when viewed in a cross section of the inductor wiring conductor in a direction orthogonal to an extending direction, a central portion of the top surface is smaller than both end portions of the top surface in terms of the height direction dimension.

6. The coil member according to any one of claims 1 to 4, wherein a difference between a maximum value and a minimum value of the height direction dimension, when viewed in a cross section of the inductor wiring conductor in a direction orthogonal to an extending direction, is 20% or less of the maximum value.

7. A method of manufacturing a coil component, wherein Possessing: a step of preparing a support substrate; a step of forming an inductor wiring conductor in a state in which the inductor wiring conductor is supported on the support substrate, the inductor wiring conductor having mutually opposed top and bottom surfaces, first and second side surfaces connecting and opposing each other between the top and bottom surfaces; a step of providing a resin-containing layer covering at least the top surface, the first side surface, and the second side surface of the inductor wiring conductor, the resin-containing layer being formed in one operation in a series of resin-containing layers such that the portion covering the top surface of the inductor wiring conductor and the portion covering the first and second side surfaces of the inductor wiring conductor are formed from a material composed of the same material in one body, and the resin-containing layer is in contact with the top surface, the first side surface, and the second side surface; and a step of removing the support substrate, The process of forming the inductor wiring conductor includes a process of making a central portion of the top surface smaller than an end portion of the top surface in terms of a height direction dimension that links between the top surface and the bottom surface when viewed on a cross section of the inductor wiring conductor in a direction orthogonal to an extending direction.

8. The method of manufacturing a coil component according to claim 7, wherein Further provided are: a process of forming a seed layer of electric conductivity on the support substrate; and a process of disposing a resist having an opening corresponding to a pattern of the inductor wiring conductor to be formed on the seed layer, the process of forming the inductor wiring conductor includes a process of forming the inductor wiring conductor on the seed layer through electroplating via the opening of the resist, the manufacturing method further includes a process of removing the resist.

9. The manufacturing method of the coil component according to claim 8, wherein the process of forming the inductor wiring conductor through electroplating includes a process of adjusting a concentration of an additive in a plating bath used for electroplating.

10. The manufacturing method of the coil component according to claim 9, wherein the process of adjusting the concentration of the additive includes a process of increasing a concentration of a leveling additive and decreasing a concentration of a bright additive.

11. The manufacturing method of the coil component according to claim 8, wherein in the process of forming the inductor wiring conductor through electroplating, as the seed layer, a seed layer in which a portion of the inductor wiring conductor corresponding to the end portion of the top surface is more protruded than a portion corresponding to the central portion of the top surface is used.

12. The manufacturing method of the coil component according to claim 8, wherein the process of forming the inductor wiring conductor through electroplating includes a process of generating a flow in a direction orthogonal to an extending direction of the inductor wiring conductor to be formed with respect to a plating bath used for electroplating.

13. The manufacturing method of the coil component according to claim 8, wherein in the process of forming the inductor wiring conductor through electroplating, the seed layer is made smaller than a width of the opening of the resist, and the seed layer is disposed at a position deviated to one side in the width direction of the opening.

14. A coil assembly, wherein, Further provided are: an inductor wiring conductor in a linear shape having a top surface and a bottom surface that are opposed to each other, a first side surface and a second side surface that link between the top surface and the bottom surface and are opposed to each other, and a resin-containing layer that covers at least the top surface, the first side surface, and the second side surface of the inductor wiring conductor, the inductor wiring conductor is configured such that, when viewed on a cross section of the inductor wiring conductor in a direction orthogonal to an extending direction, a central portion of the top surface is smaller than an end portion of the top surface in terms of a height direction dimension that links between the top surface and the bottom surface, a portion of the resin-containing layer that covers the top surface and a portion that covers the first side surface and the second side surface are made of the same material in one piece, the resin-containing layer is in contact with the top surface, the first side surface, and the second side surface, the height direction dimension of the resin-containing layer disposed at the top surface of the inductor wiring conductor is smaller than the height direction dimension of the inductor wiring conductor.

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