Inductor Components

Abstract

To improve a shear strength between a via wiring line and an internal wiring line in an inductor component.SOLUTION: An inductor component includes: a first internal wiring line; a second internal wiring line; an interlayer insulation film disposed between the first internal wiring line and the second internal wiring line and having a first main surface on the first internal wiring line side, a second main surface on the second internal wiring line side, and a via passing through between the first main surface and the second main surface; and a via wiring line inserted into the via and electrically connecting the first internal wiring line and the second internal wiring line to each other. In a first cross-section including a central axis of the via wiring line, the first main surface includes a first portion in contact with the first internal wiring line. The second main surface includes a second portion parallel to the first portion. A straight line that includes the first portion is defined as a first reference line, and a straight line that includes the second portion is defined as a second reference line. The interlayer insulation film includes a protrusion. The protrusion is in contact with the second internal wiring line and is located on the second internal wiring line relative to the second reference line.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] The present disclosure relates to inductor components. [Background technology]

[0002] An example of an electronic component is described in JP 2020-107877 A (Patent Document 1). A conventional electronic component has, for example, two internal wirings, an insulating layer having a via arranged between the internal wirings, and a via wiring inserted into the via. The via wiring electrically connects the two internal wirings. The via has a tapered shape in which the diameter decreases in the depth direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-107877 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional electronic components, the shear strength between the via wiring and the internal wiring is insufficient, and connection reliability may decrease.

[0005] An object of the present disclosure is to provide an inductor component that has excellent shear strength between via wiring and internal wiring. [Means for solving the problem]

[0006] In order to solve the above problems, an inductor component according to one aspect of the present disclosure comprises: A first internal wiring; A second internal wiring; an interlayer insulating layer disposed between the first internal wiring and the second internal wiring, the interlayer insulating layer having a first main surface on the first internal wiring side, a second main surface on the second internal wiring side, and a via penetrating between the first main surface and the second main surface; a via wiring that is inserted into the via and electrically connects the first internal wiring and the second internal wiring, In a first cross section including a central axis of the via wiring, the first main surface includes a first portion in contact with the first internal wiring; the second major surface includes a second portion parallel to the first portion; A straight line including the first portion is defined as a first reference line, A straight line including the second portion is defined as a second reference line, The interlayer insulating layer has a protrusion that is in contact with the second internal wiring and is located on the second internal wiring side with respect to the second reference line.

[0007] According to this aspect, the shear strength between the via wiring and the internal wiring can be increased. Effect of the Invention

[0008] According to an inductor component according to one aspect of the present disclosure, the shear strength between the via wiring and the internal wiring is improved. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective plan view showing a first embodiment of an inductor component. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3A] FIG. 3 is an enlarged view of part A in FIG. 2. [Figure 3B] FIG. 3B is an enlarged view of part B in FIG. 3A. [Figure 3C] FIG. 3B is an enlarged view of part C in FIG. 3A. [Figure 4A] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4B] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4C] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4D] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4E]5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4F] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4G] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4H] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4I] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4J] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4K] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. [Figure 4L] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing an inductor component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an inductor component according to one aspect of the present disclosure will be described in detail with reference to the illustrated embodiments. Note that the drawings include some schematic views and may not reflect actual dimensions or ratios.

[0011] (composition) Fig. 1 is a perspective plan view showing one embodiment of an inductor component. Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1. Fig. 2 shows an XZ cross section including a central axis AX of a via wiring. The XZ cross section is an example of a first cross section including the central axis AX. For convenience, Fig. 2 omits protrusions of an interlayer insulating layer, narrowed and convex portions of a via wiring, a concave portion of a first pad portion, and a seed layer, which will be described later. These are shown in Fig. 3A and subsequent figures.

[0012] In the figure, the thickness direction of inductor component 1 is defined as the Z direction. In a plane perpendicular to the Z direction of inductor component 1, the longitudinal direction of inductor component 1, in which first external terminal 51 and second external terminal 52 are arranged, is defined as the X direction. The width direction of inductor component 1, which is perpendicular to the longitudinal direction, is defined as the Y direction. The XZ cross-sectional view is obtained by cutting inductor component 1 at a plane formed by a straight line extending in the X direction and a straight line extending in the Z direction and including the central axis AX of the via wiring.

[0013] The inductor component 1 is mounted in, for example, electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, car electronics, etc., and is, for example, a component having an overall rectangular parallelepiped shape. However, the shape of the inductor component 1 is not particularly limited, and may be a cylindrical shape, a polygonal columnar shape, a truncated cone shape, or a polygonal truncated cone shape.

[0014] 1 and 2, the inductor component 1 has an element body 10, an inductor wiring 100, an insulating layer 30, a first vertical wiring 21, a second vertical wiring 22, a first external terminal 51, and a second external terminal 52. For convenience, the external terminals are depicted by two-dot chain lines in Fig. 1. In Fig. 1, the element body 10 and the covering film 60 are depicted as transparent so that the structure can be easily understood, but they may be translucent or opaque.

[0015] The element body 10 has a first magnetic layer 11, a substrate 70 disposed on the first magnetic layer 11, and a second magnetic layer 12 disposed on the substrate 70. The first magnetic layer 11, the substrate 70, and the second magnetic layer 12 are stacked along the central axis AX direction of the via wiring 212 so as to sandwich the inductor wiring 100 and the insulating layer 30. In other words, the inductor wiring 100 and the insulating layer 30 are provided within the element body 10. The element body 10 has a three-layer structure of the first magnetic layer 11, the substrate 70, and the second magnetic layer 12, but may have a two-layer structure of the first magnetic layer 11 and the second magnetic layer 12.

[0016] Hereinafter, the upward direction refers to the direction from the first magnetic layer 11 to the second magnetic layer 12 in the direction of the central axis AX (or Z direction) of the first via wiring 212. The upper surface of an element refers to the upward surface of the element. The downward direction refers to the direction from the second magnetic layer 12 to the first magnetic layer 11 in the direction of the central axis AX of the first via wiring 212. The lower surface of an element refers to the downward surface of the element.

[0017] The width direction is the direction perpendicular to the central axis AX direction of the first via wiring 212, and is also referred to as the Y direction as described above. The width of an element is the length of an element in the width direction. The height direction is the direction parallel to the central axis AX direction of the first via wiring 212, and is also referred to as the Z direction as described above. The height of an element is the length of an element in the height direction.

[0018] An inductor wiring refers to a curve (two-dimensional curve) that extends on a plane, and may be a curve with more than one turn, a curve with less than one turn, or a curve that may have a straight line in some parts.

[0019] The first magnetic layer 11 and the second magnetic layer 12 each have a resin and a metal magnetic powder as a magnetic body contained in the resin. Therefore, compared to a magnetic layer made of ferrite, the metal magnetic powder can improve the DC bias characteristics, and the resin insulates the metal magnetic powder from each other, thereby reducing loss (iron loss) at high frequencies.

[0020] The resin includes, for example, any of epoxy, polyimide, phenol, and vinyl ether resins. This improves insulation reliability. More specifically, the resin is epoxy, a mixture of epoxy and acrylic, or a mixture of epoxy, acrylic, and other materials. This ensures insulation between the metal magnetic powder, thereby reducing loss (iron loss) at high frequencies.

[0021] The average particle size of the metal magnetic powder is, for example, 0.1 μm or more and 5 μm or less. In the manufacturing stage of the inductor component 1, the average particle size of the metal magnetic powder can be calculated as a particle size corresponding to 50% of the integrated value in the particle size distribution obtained by the laser diffraction and scattering method. The metal magnetic powder is, for example, an FeSi-based alloy such as FeSiCr, an FeCo-based alloy, an Fe-based alloy such as NiFe, or an amorphous alloy thereof. The content of the metal magnetic powder is preferably 20 vol% or more and 70 vol% or less with respect to the entire magnetic layer. When the average particle size of the metal magnetic powder is 5 μm or less, the DC superposition characteristics are further improved, and the iron loss at high frequencies can be reduced by the fine powder. When the average particle size of the metal magnetic powder is 0.1 μm or more, uniform dispersion in the resin is facilitated, and the manufacturing efficiency of the first magnetic layer 11 and the second magnetic layer 12 is improved. Note that instead of or in addition to the metal magnetic powder, a ferrite magnetic powder such as NiZn-based or MnZn-based may be used.

[0022] The substrate 70 is laminated on the first magnetic layer 11. The substrate 70 is flat and serves as a base in the manufacturing process of the inductor component 1. The substrate 70 is made of a sintered body such as a magnetic substrate made of NiZn-based or MnZn-based ferrite, or a non-magnetic substrate made of alumina or glass. The thickness of the substrate 70 is, for example, 300 μm or more and 1000 μm or less.

[0023] The inductor wiring 100 is provided on the upper surface of the substrate 70 and extends in a direction parallel to the upper surface of the substrate 70. The inductor wiring 100 is wound in a spiral shape around the axis of the inductor wiring 100 on the upper surface of the substrate 70. The inductor wiring 100 has a spiral shape with more than one turn. When viewed from above, the inductor wiring 100 is wound in a spiral shape in a clockwise direction from the outer circumferential end to the inner circumferential end. Note that the inductor wiring 100 may be a curve with less than one turn, or may have a straight line in part.

[0024] The thickness of the inductor wiring 100 is, for example, 40 μm or more and 120 μm or less. Specifically, the inductor wiring 100 has a thickness of 45 μm, a wiring width of 50 μm, and a space between the wirings of 10 μm. The space between the wirings may be 3 μm or more and 20 μm or less.

[0025] The inductor wiring 100 has a spiral portion 120, a first pad portion 111, and a second pad portion 112. The first pad portion 111 is connected to a first vertical wiring 21, and the second pad portion 112 is connected to a second vertical wiring 22. The spiral portion 120 extends from the first pad portion 111 and the second pad portion 112 along a direction parallel to the upper surface of the substrate 70, with the first pad portion 111 as the outer circumferential end and the second pad portion 112 as the inner circumferential end, and is wound in a spiral shape.

[0026] The first vertical wiring 21 and the second vertical wiring 22 extend from the inductor wiring 100 in the direction of the central axis AX and penetrate the element body 10. The first vertical wiring 21 includes a first via wiring 212 extending upward from the upper surface of the first pad portion 111 of the inductor wiring 100 and penetrating the inside of the interlayer insulating layer 31, and a first columnar wiring 211 extending upward from the first via wiring 212 and penetrating the inside of the second magnetic layer 12. The second vertical wiring 22 includes a second via wiring 222 extending upward from the upper surface of the second pad portion 112 of the inductor wiring 100 and penetrating the interlayer insulating layer 31, and a second columnar wiring 221 extending upward from the second via wiring 222 and penetrating the inside of the second magnetic layer 12.

[0027] The inductor wiring 100 corresponds to an example of a "first internal wiring" recited in the claims. The first columnar wiring 211 corresponds to an example of a "second internal wiring" recited in the claims.

[0028] The inductor wiring 100 is made of a conductive material, for example, a metallic material with low electrical resistance such as Cu, Ag, Au, Fe, or an alloy containing these. This can reduce the DC resistance of the inductor component 1. The first vertical wiring 21 and the second vertical wiring 22 are made of the same conductive material as the inductor wiring 100.

[0029] The insulating layer 30 covers at least a part of the inductor wiring 100. The insulating layer 30 has an interlayer insulating layer 31, a resin wall 32, and a base insulating layer 33. The interlayer insulating layer 31 covers the upper surface of the inductor wiring 100, the resin wall 32 covers the side surface of the inductor wiring 100, and the base insulating layer 33 covers the lower surface of the inductor wiring 100. Specifically, the resin wall 32 is provided on the same surface as the inductor wiring 100, and is provided between the turns of the inductor wiring 100 and on the outer diameter side and inner diameter side of the inductor wiring 100. The interlayer insulating layer 31 covers the upper surface of the inductor wiring 100, and has vias at positions corresponding to the first and second pad portions 111 and 112 of the inductor wiring 100. The interlayer insulating layer 31 is provided so as to fill the gap between the upper ends of the adjacent resin walls 32. The insulating layer 30 is composed of two interlayer insulating layers 31, a resin wall 32, and a base insulating layer 33, but may be composed of one, two, or four or more insulating layers.

[0030] The interlayer insulating layer 31, the resin wall 32, and the base insulating layer 33 are made of an insulating material that does not contain a magnetic material, and include, for example, any of epoxy, polyimide, phenol, and vinyl ether resins. This improves the insulation reliability. The base insulating layer 33 may include a non-magnetic filler such as silica. The thickness of the base insulating layer 33 is, for example, 10 μm or less.

[0031] The first external terminal 51 is provided on the upper surface of the second magnetic layer 12, and covers an end face of the first columnar wiring 211 exposed from the upper surface. This allows the first external terminal 51 to be electrically connected to the first pad portion 111 of the inductor wiring 100. The second external terminal 52 is provided on the upper surface of the second magnetic layer 12, and covers an end face of the second columnar wiring 221 exposed from the upper surface. This allows the second external terminal 52 to be electrically connected to the second pad portion 112 of the inductor wiring 100.

[0032] The first external terminal 51 and the second external terminal 52 are made of a conductive material. The first external terminal 51 and the second external terminal 52 have a three-layer structure in which metal layers made of Cu, which has low electrical resistance and excellent stress resistance, Ni, which has excellent corrosion resistance, and Au, which has excellent solder wettability and reliability, are laminated from the inside to the outside in this order.

[0033] FIG. 3A is an enlarged view of the A portion in FIG. 2. FIG. 3A shows a part of the first cross section including the central axis AX of the via wiring. The interlayer insulating layer 31 has a first main surface 31X on the first pad portion 111 side, a second main surface 31Y on the first columnar wiring 211 side, and a via 31Z penetrating between the first main surface 31X and the second main surface 31Y. The first main surface 31X includes a first portion 31Xa in contact with the first pad portion 111. The first main surface 31X further includes a third portion 31Xb not in contact with the first pad portion 111. The third portion 31Xb is located at the end of the first main surface 31X on the via 31Z side. The second main surface 31Y includes a second portion 31Ya parallel to the first main surface 31X.

[0034] The interlayer insulating layer 31 has a protrusion 312 in contact with the first columnar wire 211. When a straight line including the first portion 31Xa is defined as a first reference line S1 and a straight line including the second portion 31Ya is defined as a second reference line S2, the protrusion 312 is in contact with the first columnar wire 211 and is located closer to the first columnar wire 211 than the second reference line S2 of the interlayer insulating layer 31. In FIG. 3A, the first reference line S1 and the second reference line S2 are each indicated by a dotted line.

[0035] The protrusion 312 is disposed on the side of the first columnar wiring 211 and bites into the first columnar wiring 211. This enhances the adhesion between the interlayer insulating layer 31 and the first columnar wiring 211, thereby improving the shear strength between the first columnar wiring 211 and the first via wiring 212. In particular, even when an external force is applied in the width direction, peeling between the interlayer insulating layer 31 and the first columnar wiring 211 is prevented. This improves the connection reliability of the inductor component 1.

[0036] By providing the protrusion 312 on the first columnar wiring 211 side of the interlayer insulating layer 31, the shear strength between the first columnar wiring 211 and the first via wiring 212 can be improved more than in the case where the shape of the via 31Z is devised. Also, by providing the protrusion 312 on the first columnar wiring 211 side of the interlayer insulating layer 31, the shear strength between the first columnar wiring 211 and the first via wiring 212 can be improved more than in the case where a recess is formed on the second main surface 31Y side of the interlayer insulating layer 31. In addition, when the recess on the second main surface 31Y side of the interlayer insulating layer 31 is formed by grinding the interlayer insulating layer 31, the risk of residue generation increases.

[0037] The interlayer insulating layer 31 has a protrusion 312 located on the first columnar wiring 211 side of the second reference line S2, and a main body portion 311 located on the first pad portion 111 side of the second reference line S2. The protrusion 312 and the main body portion 311 are integrally formed. In this case, there is no need to perform a separate process for forming the protrusion 312, and therefore the manufacturing cost is reduced.

[0038] "Protrusion 312 and main body 311 are integrally formed" means that protrusion 312 and main body 311 are formed in contact with each other without a clear interface being visible between them.

[0039] The via 31Z has a first opening end 31Za on the side of the first pad portion 111 and a second opening end 31Zb on the side of the first columnar wiring 211. The via 31Z has an inner surface that connects the first opening end 31Za and the second opening end 31Zb.

[0040] The protrusion 312 includes the second opening end 31Zb of the via 31Z and constitutes a part of the inner surface of the via 31Z. This further enhances the adhesion between the interlayer insulating layer 31 and the first columnar wiring 211, and further improves the shear strength between the first columnar wiring 211 and the first via wiring 212.

[0041] The inner surface of the via 31Z is inclined so that the width of the via 31Z in a direction perpendicular to the central axis AX (X direction in the XZ cross section) increases from the first pad portion 111 toward the first columnar wiring 211. Only a portion of the inner surface of the via 31Z may be inclined as described above.

[0042] Fig. 3B shows an enlarged view of the periphery of the protrusion 312. Fig. 3B is an enlarged view of part B in Fig. 3A. The maximum height H1 of the protrusion 312 in the direction of the central axis AX may be 5% or more and 30% or less of the distance H0 between the first reference line S1 and the second reference line S2 in the direction of the central axis AX (hereinafter referred to as the thickness H0 of the interlayer insulating layer 31). When the maximum height H1 is 5% or more of the thickness H0 of the interlayer insulating layer 31, the effect of improving the shear strength by the protrusion 312 is easily obtained. When the maximum height H1 is 30% or less of the thickness H0 of the interlayer insulating layer 31, the shape of the first columnar wiring 211 is less likely to be affected. The maximum height H1 of the protrusion 312 may be 10% or more, or may be 15% or more of the thickness H0 of the interlayer insulating layer 31. The maximum height H1 of the protrusion 312 may be 28% or less, or may be 25% or less of the thickness H0 of the interlayer insulating layer 31. The maximum height H1 of the protrusion 312 is the distance from the second reference line S2 to the highest point of the protrusion 312.

[0043] The maximum width W1 of the protrusion 312 in a direction perpendicular to the central axis AX may be 1% or more and 80% or less of the thickness H0 of the interlayer insulating layer 31. When the maximum width W1 is 1% or more of the thickness H0 of the interlayer insulating layer 31, the effect of improving the shear strength by the protrusion 312 is easily obtained. When the maximum width W1 is 80% or less of the thickness H0 of the interlayer insulating layer 31, the shape of the first columnar wiring 211 is less likely to be affected. The maximum width W1 of the protrusion 312 may be 5% or more, or may be 10% or more of the thickness H0 of the interlayer insulating layer 31. The maximum width W1 of the protrusion 312 may be 50% or less, or may be 40% or less of the thickness H0 of the interlayer insulating layer 31. The maximum width W1 of the protrusion 312 refers to the maximum of the widths of the protrusion 312 in a direction parallel to the second reference line S2. Typically, the maximum width W1 of the protrusion 312 is the width of the protrusion 312 at the second reference line S2.

[0044] (Wedge part) 3A, the first via wiring 212 has a wedge portion 212a sandwiched between the interlayer insulating layer 31 and the first pad portion 111 in a direction parallel to the central axis AX. More specifically, the wedge portion 212a is disposed between the first pad portion 111 and a third portion 31Xb that does not contact the first pad portion 111 of the first main surface 31X. This generates an anchor effect of the wedge portion 212a on the interlayer insulating layer 31 and the first pad portion 111, and also improves the adhesion between the first via wiring 212 and the first pad portion 111. This further improves the connection reliability.

[0045] Fig. 3C shows an enlarged view of the periphery of the wedge portion 212a. Fig. 3C is an enlarged view of part C in Fig. 3A. When a straight line including the first opening end 31Za of the via 31Z and parallel to the central axis AX is defined as a third reference line S3, the wedge portion 212a is located on the opposite side of the central axis AX with respect to the third reference line S3 of the first via wiring 212. In Fig. 3C, the third reference line S3 is indicated by a dotted line.

[0046] The third portion 31Xb is inclined with respect to the first reference line S1 so that the distance between the third portion 31Xb and the first reference line S1 in the direction parallel to the central axis AX increases toward the central axis AX. This makes it easier for a plating solution to enter between the third portion 31Xb and the first pad portion 111 when the first via wiring 212 is formed by plating, thereby suppressing the generation of voids in the wedge portion 212a. The voids may cause breakage of the plating coating, in this case, the first via wiring 212. Only a part of the third portion 31Xb may be inclined so that the distance between the third portion 31Xb and the first reference line S1 in the direction parallel to the central axis AX increases.

[0047] The height H2 of the wedge portion 212a may be 10% or more and 30% or less of the thickness H0 of the interlayer insulating layer 31. When the height H2 is 10% or more of the thickness H0 of the interlayer insulating layer 31, the above-mentioned anchor effect is easily obtained. When the height H2 is 30% or less of the thickness H0 of the interlayer insulating layer 31, when the first via wiring 212 is formed by plating, the plating solution is easily inserted between the third portion 31Xb and the first pad portion 111, so that the generation of voids in the wedge portion 212a is easily suppressed. In addition, poor circulation of the plating solution is suppressed, so that a plating film with high crystallinity is easily formed. The height H2 of the wedge portion 212a may be 15% or more and may be 20% or more of the thickness H0 of the interlayer insulating layer 31. The height H2 of the wedge portion 212a may be 30% or less of the thickness H0 of the interlayer insulating layer 31, and may be 25% or less. The height H2 of the wedge portion 212a is the distance from the first opening end 31Za to the intersection of the third reference line S3 and the first pad portion 111.

[0048] (Concave, convex) 3A and 3C, the first pad portion 111 has a recess 111a recessed from the first reference line S1. The first via wiring 212 has a protrusion 212b that fits into the recess 111a. This increases the contact area between the first pad portion 111 and the first via wiring 212, further improving adhesion.

[0049] In this embodiment, the entire end of the interlayer insulating layer 31 on the via 31Z side is raised upward to form the protrusion 312. At this time, an inclined third portion 31Xb is also formed, and a gap (gap 40 shown in FIG. 4F and FIG. 4G) is generated between the interlayer insulating layer 31 and the first pad portion 111, and the inner surface of the via 31Z has a tapered shape that widens toward the upward direction. A part of the first via wiring 212 enters this gap to form a wedge portion 212a. The entire end of the interlayer insulating layer 31 is a region at the end that is sandwiched between the first main surface 31X and the second main surface 31Y.

[0050] In Fig. 2, cross sections of two via wirings 212, 222 are shown in a cross section including the central axis AX, but it is sufficient that at least one of the two, the first via wiring 212, satisfies the various configurations described above and shown in Figs. 3A to 3C. In other cross sections including the central axis AX, the various configurations described above and shown in Figs. 3A to 3C may or may not be satisfied. It is sufficient that at least one of the multiple via wirings included in the inductor component 1 satisfies the various configurations described above and shown in Figs. 3A to 3C.

[0051] (Manufacturing method) Next, a method for manufacturing the inductor component 1 will be described with reference to Figures 4A to 4L. Figures 4A to 4L are diagrams corresponding to the first pad portion 111 and the first vertical wiring 21 of the inductor wiring 100 in Figure 2.

[0052] As shown in Fig. 4A, a base insulating layer 33 that does not contain a magnetic material is formed on a substrate 70. The substrate 70 is made of, for example, sintered ferrite and has a flat plate shape.

[0053] The base insulating layer 33 is made of, for example, a polyimide resin or an inorganic material that does not contain a magnetic material. After the polyimide resin is coated on the substrate 70 by printing, painting, or the like, the polyimide resin is left in the region where the inductor wiring 100 is to be formed by patterning using a photolithography method. This forms the base insulating layer 33. The insulating film made of an inorganic material is formed on the substrate 70 by, for example, a dry process such as deposition, sputtering, or CVD.

[0054] 4B, a seed layer 81 is formed on the underlying insulating layer 33. Specifically, a material for the seed layer 81 (e.g., a titanium / copper alloy) is deposited on the upper surface of the underlying insulating layer 33 by sputtering, and then patterned by a subtractive method to form the seed layer 81.

[0055] As shown in FIG. 4C, the resin wall 32 is formed on the base insulating layer 33. The resin wall 32 is formed, for example, by a photosensitive permanent photoresist. The photosensitive permanent photoresist is a photoresist that is not removed after processing. Specifically, the material of the resin wall 32 is printed on the substrate 70 and exposed to light. Thereafter, development is performed using an organic solvent such as PGMEA (propylene glycol monomethyl ether acetate pegmia) and an alkaline developer such as TMAH (tetramethyl ammonium hydroxide). As a result, the material in the unexposed portion is removed, and the resin wall 32 is formed.

[0056] 4D, a first pad portion 111 and a spiral portion 120 are formed on the seed layer 81. Specifically, plating is grown on the seed layer 81 by electrolytic plating. As a result, the first pad portion 111 and the spiral portion 120 are formed between the resin walls 32.

[0057] As shown in FIG. 4E, a photosensitive insulating layer 310 is disposed, which covers the spiral portion 120 and has a through hole exposing the upper surface of the first pad portion 111. Specifically, a photosensitive insulating film is laminated so as to cover the first pad portion 111 and the spiral portion 120. The photosensitive insulating film is also made of a photosensitive permanent photoresist. Next, the photosensitive insulating film is exposed to light and photocured. Thereafter, development is performed to form the photosensitive insulating layer 310 having a through hole, and a part of the first pad portion 111 is exposed from the photosensitive insulating layer 310.

[0058] FIG. 4F is an enlarged view showing the periphery of the through hole formed in the photosensitive insulating layer 310. As shown in FIG. 4F, a recess 111a is formed in the portion of the first pad portion 111 exposed from the photosensitive insulating layer 310. The recess 111a is formed by an etching process. At this time, by isotropic etching, a gap 40 is formed between the photosensitive insulating layer 310 and the first pad portion 111 together with the recess 111a. The gap 40 causes the end of the photosensitive insulating layer 310 to peel off from the first pad portion 111. When the peeled portion of the photosensitive insulating layer 310 is thermally cured, it rises upward to form a protrusion 312. The gap 40 is filled with plating, forming a wedge portion 212a.

[0059] The height H1 and width W1 of the protrusion 312 are controlled by the amount of etching of the first pad portion 111. The amount of etching is set appropriately according to the size of the protrusion 312. For example, if the first pad portion 111 is formed by copper plating, an agent that preferentially dissolves copper oxide over copper may be used for etching. Alternatively, the amount of etching may be adjusted by appropriately adjusting the processing time and temperature. The height H2 of the wedge portion 212a is also controlled by the amount of etching of the first pad portion 111.

[0060] FIG. 4G is an enlarged view of the periphery of the through-hole formed in the photosensitive insulating layer 310, similar to FIG. 4F. As shown in FIG. 4G, an interlayer insulating layer 31 having a protrusion 312 is formed. Specifically, the photosensitive insulating layer 310 is heated to thermally harden it. At this time, since the outer surface side of the photosensitive insulating layer 310 is easily contracted and the photosensitive insulating layer 310 has a peeled portion, the end of the photosensitive insulating layer 310 on the through-hole side rises upward, forming the protrusion 312. According to this method, the main body 311 and the protrusion 312 are integrally formed, so that the manufacturing cost is reduced. The heating is performed, for example, at 150° C. or more and 200° C. or less for about one hour.

[0061] The protrusion 312 constitutes a part of the inner surface of the through hole, that is, the via 31Z. The peeled portion of the photosensitive insulating layer 310 forms a third portion 31Xb on the first main surface 31X of the interlayer insulating layer 31 that does not contact the first pad portion 111.

[0062] As shown in FIG. 4H, a seed layer 82 is formed by sputtering on the inner surface of the via 31Z, the exposed portion of the upper surface of the first pad portion 111, the interlayer insulating layer 31, and the upper surface of the resin wall 32. When the height of the gap 40 (height H2 of the wedge portion 212a) is 10% or more and 30% or less of the thickness H0 of the interlayer insulating layer 31, it becomes easy to form a seed layer on the third portion 31Xb forming the gap 40 and the upper surface of the first pad portion 111. This suppresses the generation of voids in the plating film in the subsequent plating process. The voids can cause breakage of the plating film, here the first via wiring 212 and the first columnar wiring 211.

[0063] As shown in FIG. 4I, first via wiring 212 and first columnar wiring 211 are formed in a portion corresponding to the exposed portion of the upper surface of first pad portion 111. Specifically, a resist film 320 is formed on seed layer 82, and an opening is provided in resist film 320 at a position corresponding to first via wiring 212. Plating is grown on seed layer 82 by electrolytic plating to form a plating layer in the above-mentioned opening. As a result, first via wiring 212 and first columnar wiring 211 are formed in the opening.

[0064] As shown in FIG. 4J, the resist film 320 is peeled off, the exposed seed layer 82 is removed, and the second magnetic layer 12 is formed on the interlayer insulating layer 31. Furthermore, the first magnetic layer 11 is formed on the lower surface of the substrate 70. The first magnetic layer 11 and the second magnetic layer 12 are formed by pressing a magnetic layer onto the interlayer insulating layer 31 or the lower surface of the substrate 70. Before pressing the second magnetic layer 12, a part of the substrate 70 is ground to adjust the thickness. The substrate 70 may be removed.

[0065] As shown in FIG. 4K, the second magnetic layer 12 is ground to expose the top surface of the first columnar wiring 211.

[0066] 4L, a first external terminal 51 is formed on the top surface of the first columnar wiring 211, and a coating film 60 is formed to cover the other portion of the second magnetic layer 12. The coating film 60 is formed of, for example, a solder resist. After that, the inductor component 1 is manufactured by dividing the resultant into individual pieces using a dicer or the like.

[0067] The present disclosure is not limited to the above-described embodiments, and design modifications are possible without departing from the gist of the present disclosure.

[0068] In the above embodiment, the inductor wiring 100 is a single layer, but a plurality of inductor wirings 100 may be laminated in the direction of the central axis AX. Also, a plurality of inductor wirings 100 may be arranged in a direction perpendicular to the direction of the central axis AX.

[0069] In the embodiment, the protrusion 312 and the main body 311 are integrally formed, but the protrusion 312 and the main body 311 may be formed separately. The protrusion 312 formed separately from the main body 311 may be disposed on the first columnar wire 211 side of the main body 311.

[0070] In the above embodiment, the protrusion 312 is provided at the second opening end 31Zb of the via 31Z, but it may be provided at a location away from the second opening end 31Zb of the via 31Z.

[0071] In the above embodiment, one protrusion 312 is provided at the second opening end 31Zb of the via 31Z, but a plurality of protrusions may be provided.

[0072] In the embodiment, the first columnar wiring 211 is exemplified as the "second internal wiring" in the claims, but the "second internal wiring" in the claims may be a second inductor wiring.

[0073] In the embodiment, the first via wiring 212 has both the wedge portion 212a and the protrusion portion 212b, but the first via wiring 212 does not have to have either the wedge portion 212a or the protrusion portion 212b, and may have either one of them.

[0074] In the above embodiment, the first pad portion 111 has the recess 111a, but the first pad portion 111 does not necessarily have to have the recess 111a.

[0075] In the above embodiment, the first main surface 31X of the interlayer insulating layer 31 includes a third portion 31Xb at the end on the via 31Z side that does not contact the first pad portion 111, but the first main surface 31X of the interlayer insulating layer 31 does not have to include the third portion 31Xb.

[0076] In the embodiment, the entire third portion 31Xb of the interlayer insulating layer 31 is inclined so that the distance from the first reference line S1 increases toward the central axis AX, but a part of the third portion 31Xb may be inclined, that is, the third portion 31Xb may have an inclined portion. The third portion 31Xb does not have to have an inclined portion.

[0077] In the embodiment, the inner surface of the via 31Z is inclined so that the width of the via 31Z increases from the first pad portion 111 toward the first columnar wire 211, but a part of the inner surface of the via 31Z may be inclined, that is, the inner surface of the via 31Z may have an inclined portion. The inner surface of the via 31Z may have an inclined portion where the width of the via 31Z decreases from the first pad portion 111 toward the first columnar wire 211. The inner surface of the via 31Z may extend in a direction along the central axis AX.

[0078] The present disclosure includes the following aspects. <1> A first internal wiring; A second internal wiring; an interlayer insulating layer disposed between the first internal wiring and the second internal wiring, the interlayer insulating layer having a first main surface on the first internal wiring side, a second main surface on the second internal wiring side, and a via penetrating between the first main surface and the second main surface; a via wiring that is inserted into the via and electrically connects the first internal wiring and the second internal wiring, In a first cross section including a central axis of the via wiring, the first main surface includes a first portion in contact with the first internal wiring; the second major surface includes a second portion parallel to the first portion; A straight line including the first portion is defined as a first reference line, A straight line including the second portion is defined as a second reference line, The interlayer insulating layer is in contact with the second internal wiring and has a protrusion located on the second internal wiring side of the second reference line. <2> In the first cross section, the via has a first opening end on the first internal wiring side and a second opening end on the second internal wiring side; The protrusion includes the second open end of the via and constitutes a part of the inner surface of the via. <1> 2. An inductor component according to claim 1 . <3> a maximum height of the protrusion in the central axis direction is 5% to 30% of a distance between the first reference line and the second reference line in the central axis direction; <1> or <2> 2. An inductor component according to claim 1 . <4> a maximum width of the protrusion in a direction perpendicular to the central axis is 1% to 80% of a distance between the first reference line and the second reference line in the central axis direction; <1> from <3> 2. An inductor component according to claim 1 . <5> the interlayer insulating layer has the protrusion and a main body portion located on the first internal wiring side of the second reference line, The protrusion and the main body are integrally formed. <1> from <4> 2. An inductor component according to claim 1 . <6> In the first cross section, the via wiring has a wedge portion sandwiched between the interlayer insulating layer and the first internal wiring in a direction parallel to the central axis; <1> from <5> 2. An inductor component according to claim 1 . <7> the via has a first opening end on the first internal wiring side and a second opening end on the second internal wiring side; A straight line including the first opening end and parallel to the central axis is defined as a third reference line, the wedge portion is located on an opposite side of the central axis with respect to the third reference line of the via wiring, a height of the wedge portion from the first opening end to an intersection of the third reference line and the first internal wiring is 10% or more and 30% or less of a distance in the central axis direction between the first reference line and the second reference line; <6> 2. An inductor component according to claim 1 . <8> In the first cross section, the first main surface includes a third portion at an end portion on the via side that is not in contact with the first internal wiring, the wedge portion is disposed between the third portion and the first internal wiring. <6> or <7> 2. An inductor component according to claim 1 . <9> In the first cross section, the third portion has an inclined portion in which the distance between the third portion and the first reference line in a direction parallel to the central axis increases toward the central axis, <8> 2. An inductor component according to claim 1 . <10> In the first cross section, an inner surface of the via has an inclined portion whose width increases in a direction perpendicular to the central axis of the via from the first internal wiring toward the second internal wiring; <1> from <9> 2. An inductor component according to claim 1 . <11> the first internal wiring has a recess recessed from the first reference line, The via wiring has a protrusion that fits into the recess. <1> from <10> 2. An inductor component according to claim 1 . <12> Further, the magnetic recording medium includes an element body including a magnetic layer, the first internal wiring and the second internal wiring are provided within the element body, At least one of the first internal wiring and the second internal wiring is an inductor wiring. <1> from <11> 2. An inductor component according to claim 1 . [Explanation of symbols]

[0079] 1. Inductor components 10 Base 11 First magnetic layer 12 Second magnetic layer 21 1st vertical wiring 211 1st pillar wiring 212 First via wiring 212a Wedge 212b Convex 22 2nd vertical wiring 221 2nd pillar wiring 222 2nd via wiring 30 Insulating layer 31 Interlayer insulation layer 31X 1st main surface 31Xa Part 1 31Xb 3rd part 31Y 2nd main surface 31Ya 2nd part 31Z Via 31Za 1st opening end 31Zb 2nd open end 311 Main body 312 Protrusion 32 Resin Wall 33 Undercoat insulation layer 40 Gap 51 First external terminal 52 Second external terminal 60 Coating membrane 70 Substrate 81,82 Seed layer 100 Inductor wiring 111 First pad section 111a Recess 112 Second pad section 120 Spiral Section 310 Photosensitive insulating layer 320 Resist film AX center axis S1 1st reference line S2 2nd reference line S3 Third Reference Line

Claims

1. A first internal wiring; A second internal wiring; an interlayer insulating layer disposed between the first internal wiring and the second internal wiring, the interlayer insulating layer having a first main surface on the first internal wiring side, a second main surface on the second internal wiring side, and a via penetrating between the first main surface and the second main surface; a via wiring that is inserted into the via and electrically connects the first internal wiring and the second internal wiring, In a first cross section including a central axis of the via wiring, the first main surface includes a first portion in contact with the first internal wiring; the second major surface includes a second portion parallel to the first portion; A straight line including the first portion is defined as a first reference line, A straight line including the second portion is defined as a second reference line, The interlayer insulating layer is in contact with the second internal wiring and has a protrusion located on the second internal wiring side of the second reference line.

2. In the first cross section, the via has a first opening end on the first internal wiring side and a second opening end on the second internal wiring side; The inductor component according to claim 1 , wherein the protrusion includes the second open end of the via and forms a part of an inner surface of the via.

3. 3 . The inductor component according to claim 1 , wherein a maximum height of the protrusion in the central axis direction is 5% to 30% of a distance in the central axis direction between the first reference line and the second reference line.

4. 3. The inductor component according to claim 1, wherein the maximum width of the protrusion in a direction perpendicular to the central axis is 1% or more and 80% or less of the distance in the central axis direction between the first reference line and the second reference line.

5. the interlayer insulating layer has the protrusion and a main body portion located on the first internal wiring side of the second reference line, The inductor component according to claim 1 , wherein the projection and the main body are integrally formed.

6. In the first cross section, 3 . The inductor component according to claim 1 , wherein the via wiring has a wedge portion sandwiched between the interlayer insulating layer and the first internal wiring in a direction parallel to the central axis.

7. the via has a first opening end on the first internal wiring side and a second opening end on the second internal wiring side; A straight line including the first opening end and parallel to the central axis is defined as a third reference line, the wedge portion is located on an opposite side of the central axis with respect to the third reference line of the via wiring, 7. The inductor component of claim 6, wherein a height of the wedge portion from the first opening end to an intersection of the third reference line and the first internal wiring is greater than or equal to 10% and less than or equal to 30% of a distance in the central axis direction between the first reference line and the second reference line.

8. In the first cross section, the first main surface includes a third portion at an end portion on the via side that is not in contact with the first internal wiring, The inductor component according to claim 6 , wherein the wedge portion is disposed between the third portion and the first internal wiring.

9. In the first cross section, The inductor component according to claim 8 , wherein the third portion has an inclined portion in which a distance between the third portion and the first reference line in a direction parallel to the central axis increases toward the central axis.

10. In the first cross section, 3. The inductor component according to claim 1, wherein an inner surface of the via has an inclined portion whose width increases in a direction perpendicular to the central axis of the via from the first internal wiring toward the second internal wiring.

11. the first internal wiring has a recess recessed from the first reference line, The inductor component according to claim 1 , wherein the via wiring has a protrusion that fits into the recess.

12. Further, the magnetic recording medium includes an element body including a magnetic layer, the first internal wiring and the second internal wiring are provided within the element body, 3. The inductor component according to claim 1, wherein at least one of the first internal wiring and the second internal wiring is an inductor wiring.

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