JP7411590B2 - Inductor parts and their manufacturing method - Google Patents

Description

The present invention relates to an inductor component and a method for manufacturing the same.

Conventionally, as an inductor component, there is one described in Japanese Unexamined Patent Publication No. 2013-225718 (Patent Document 1). This inductor component includes an insulating substrate, a spiral conductor formed on the main surface of the insulating substrate, an insulating resin layer covering the spiral conductor, an upper core and a lower core covering the top and back sides of the insulating substrate, and a pair of and a terminal electrode. The insulating substrate is a general printed circuit board material made of glass cloth impregnated with epoxy resin, and the size of the insulating substrate is 2.5 mm x 2.0 mm x 0.3 mm. The upper core and lower core are resin containing metal magnetic powder.

Furthermore, Japanese Patent Laid-Open No. 2007-305824 (Patent Document 2) describes a sheet-like element body, a planar coil constituting a coil formed inside the element body, and a terminal formed on the outermost periphery of the coil. The inductor components provided are described. The element body is a stack of insulating layers made of photoresist. A portion of the terminal is made of magnetic material. A magnetic middle leg made of a magnetic material is formed in the inner circumferential direction of the coil in the element body. Note that this inductor component is formed by laminating an element body and the like on a substrate made of silicon or the like, and then removing the substrate by treatment with hydrofluoric acid or the like.

JP2013-225718A Japanese Patent Application Publication No. 2007-305824

By the way, in Patent Document 1, a spiral conductor is formed on an insulating substrate made of a printed circuit board material on the order of several hundred μm, and there is a limit to reducing the height of the entire inductor component. Further, for example, when considering removing the insulating substrate by etching or polishing as in Patent Document 2 in order to achieve a lower height in the structure of Patent Document 1, in Patent Document 1 the spiral conductor is removed from the insulating substrate. Since the spiral conductor is formed directly above the spiral conductor, there is a high possibility that a portion of the bottom surface of the spiral conductor will also be removed when the insulating substrate is removed. In this way, if even the spiral conductor is removed, the direct current resistance (Rdc) will increase (deteriorate), and the amount of spiral conductor removed will inevitably vary depending on the removal process during mass production. , and may cause variations in Rdc.

Further, in Patent Document 1, the spiral conductor is covered with an insulating resin layer, and in Patent Document 2, the element body is a photoresist (non-magnetic material), so the insulating resin layer and photoresist cover the entire part. It accounts for a large proportion of the total. Therefore, components have become smaller and lower in profile, including magnetic materials (the core of Patent Document 1, magnetic terminals and magnetic middle legs of Patent Document 2) and wiring (spiral conductors of Patent Document 1, flat surfaces of Patent Document 2). There is a possibility that a sufficient area for forming the coil (coil) cannot be secured, and that both inductance (L) and Rdc cannot be secured sufficiently. That is, there is a possibility that one or both of L and Rdc will be sacrificed due to the reduction in size and height.

As described above, conventional inductor components cannot be said to have a configuration suitable for miniaturization and low profile.

Therefore, an object of the present disclosure is to provide an inductor component suitable for reduction in size and height, and a method for manufacturing the same.

In order to solve the above problems, an inductor component that is one aspect of the present disclosure includes:
an insulating layer that does not contain magnetic material;
a spiral wiring formed on a first main surface of the insulating layer and wound on the first main surface;
and a magnetic layer in contact with at least a portion of the spiral wiring.

Here, the spiral wiring is a curve (two-dimensional curve) formed on a plane, and may be a curve with more than one turn, or a curve with less than one turn. , may have a straight line in part.

According to the inductor component of the present disclosure, since the spiral wiring is formed on the first main surface of the insulating layer, the substrate can be removed (etching, polishing, etc.) from the second main surface side (lower side) of the insulating layer. The spiral wiring is protected against the following processing processes. This makes it possible to suppress an increase in direct current resistance (Rdc) and variations in Rdc during mass production.

Furthermore, since the magnetic layer is in contact with the spiral wiring, the proportion of the insulating layer in the entire inductor component is reduced, and an area for forming the spiral wiring and the magnetic layer can be secured. Thereby, the trade-off relationship between inductance (L) and Rdc can be improved.

Therefore, an inductor component suitable for reduction in size and height can be realized.

Further, in one embodiment of the inductor component, the magnetic layer is in contact with a side surface of the spiral wiring at a contact portion with the spiral wiring.

According to the embodiment, the proportion of the insulating layer is reduced.

Further, in one embodiment of the inductor component, the magnetic layer is in contact with the upper surface of the spiral wiring at a contact portion with the spiral wiring.

According to the embodiment, the proportion of the insulating layer is reduced.

Further, in one embodiment of the inductor component, the magnetic layer is in contact with the spiral wiring from a side surface to an upper surface at a contact portion with the spiral wiring.

According to the embodiment, the proportion of the insulating layer is further reduced.

Further, in one embodiment of the inductor component, the thickness of the insulating layer is thinner than the thickness of the spiral wiring.

According to the embodiment, the proportion of the insulating layer is further reduced.

Further, in one embodiment of the inductor component, the thickness of the insulating layer is 10 μm or less.

According to the embodiment, the proportion of the insulating layer is further reduced.

Moreover, in one embodiment of the inductor component, the insulating layer has a shape along the spiral wiring.

According to the embodiment, since no insulating layer is provided in the region where the spiral wiring is not formed, the ratio of the insulating layer is further reduced.

Additionally, in one embodiment of the inductor component,
further comprising: a columnar wiring penetrating the inside of the magnetic layer in a direction normal to the first main surface; and an external terminal formed outside the magnetic layer;
The spiral wiring and the columnar wiring are in direct contact with each other, and the columnar wiring and the external terminal are in direct contact with each other.

According to the embodiment, since there is no via conductor, it is possible to reduce the height of the inductor component, reduce Rdc, and improve connection reliability.

Further, in one embodiment of the inductor component, the spiral wiring has only one layer.

According to the embodiment, the height of the inductor component can be reduced.

Further, in one embodiment of the inductor component, all side surfaces of the spiral wiring are in contact with the magnetic layer.

According to the embodiment, the proportion of the insulating layer is further reduced.

Further, in one embodiment of the inductor component, the entire upper surface of the spiral wiring is in contact with the magnetic layer except for a portion that contacts the columnar wiring.

According to the embodiment, the proportion of the insulating layer is further reduced.

Additionally, in one embodiment of the inductor component,
The spiral wiring has a spiral shape having more than one turn,
In a region running parallel to the spiral wiring over one circumference, side surfaces of the spiral wiring are covered with the insulating layer.

According to the embodiment, the insulation and voltage resistance of the spiral wiring can be improved.

Further, in one embodiment of the method for manufacturing an inductor component,
a step of preparing a substrate;
forming an insulating layer containing no magnetic material on the substrate;
forming a spiral wiring on the first main surface so as to be wound on the first main surface of the insulating layer;
forming a magnetic layer on the insulating layer so as to contact at least a portion of the spiral wiring;
and removing the substrate.

According to the embodiment, the spiral wiring is protected by the insulating layer when the substrate is removed, and an increase in Rdc and variation in Rdc during mass production can be suppressed. Further, since the magnetic layer is in contact with the spiral wiring, the ratio of the insulating layer to the entire inductor component is reduced, and the trade-off relationship between L and Rdc can be improved. Therefore, it is possible to manufacture an inductor component suitable for reduction in size and height.

Further, in one embodiment of the method for manufacturing an inductor component, the insulating layer is removed leaving a portion along the spiral wiring.

According to the embodiment, the proportion of the insulating layer is further reduced.

Further, in one embodiment of the method for manufacturing an inductor component,
After the spiral wiring is formed and before the magnetic layer is formed, a columnar wiring is formed extending from the spiral wiring in the normal direction of the first main surface, and the magnetic layer is formed so that the upper end of the columnar wiring is exposed. Form.

According to the embodiment, since there is no via conductor, it is possible to reduce the height of the inductor component, reduce Rdc, and improve connection reliability.

According to an inductor component and a method for manufacturing the same that are one aspect of the present disclosure, an inductor component suitable for reduction in size and height can be realized.

FIG. 2 is a perspective plan view showing an inductor component according to the first embodiment. FIG. 2 is a sectional view showing an inductor component according to the first embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. It is an explanatory view explaining the manufacturing method of the inductor component concerning a 1st embodiment. FIG. 7 is a cross-sectional view showing an inductor component according to a second embodiment. FIG. 7 is a cross-sectional view showing an inductor component according to a third embodiment. FIG. 7 is a transparent perspective view showing an inductor component according to a fourth embodiment. It is a sectional view showing an inductor component concerning a 4th embodiment.

Hereinafter, one aspect of the present disclosure will be described in detail with reference to illustrated embodiments.

(First embodiment)
(composition)
FIG. 1 is a perspective plan view showing a first embodiment of an inductor component. FIG. 2 is a sectional view taken along line XX in FIG.

The inductor component 1 is mounted in electronic equipment such as a personal computer, a DVD player, a digital camera, a TV, a mobile phone, and a car electronics, and is, for example, a rectangular parallelepiped-shaped component as a whole. However, the shape of the inductor component 1 is not particularly limited, and may be a cylinder, a polygonal column, a truncated cone, or a truncated polygon.

As shown in FIGS. 1 and 2, the inductor component 1 includes a magnetic layer 10, an insulating layer 15, a spiral wiring 21, columnar wiring 31, 32, external terminals 41, 42, and a coating film 50. have

The insulating layer 15 has a first main surface 15a that is an upper surface and a second main surface 15b that is a lower surface. The normal direction of the insulating layer 15 to the first main surface 15a is defined as the Z direction in the figure, with the forward Z direction being the upper side and the reverse Z direction being the lower side.

The insulating layer 15 is a layer shaped along the spiral wiring 21 when viewed from above. In this way, since the insulating layer 15 is not provided in the region where the spiral wiring 21 is not formed, the proportion of the insulating layer 15 in the entire inductor component 1 is further reduced. Note that in the drawing, the insulating layer 15 is combined in the region between the spiral wires 21, but may be divided in the region between the spiral wires 21. Further, the insulating layer 15 may not be shaped along the spiral wiring 21 but may be a flat layer.

The thickness of the insulating layer 15 is preferably thinner than the spiral wiring 21, so that the ratio of the insulating layer 15 is further reduced. Further, the thickness of the insulating layer 15 is preferably 10 μm or less, and the ratio of the insulating layer 15 is further reduced.

The insulating layer 15 is made of an insulating material that does not contain a magnetic substance, and is made of a resin material such as an epoxy resin, a phenol resin, or a polyimide resin, or an inorganic material such as a silicon or aluminum oxide film or a nitride film. Since the insulating layer 15 does not contain a magnetic substance, the flatness of the first main surface 15a of the insulating layer 15 is ensured, and the spiral wiring 21 can be formed satisfactorily on the first main surface 15a. Can prevent conduction between wires. Note that the insulating layer 15 preferably has a structure that does not contain filler, and in this case, the insulating layer 15 can be made thinner and its flatness can be improved. On the other hand, when the insulating layer 15 contains a non-magnetic filler such as silica, the strength, workability, and electrical characteristics of the insulating layer 15 can be improved.

The spiral wiring 21 is formed on the first main surface 15a of the insulating layer 15, and is wound on the first main surface 15a. The spiral wiring 21 has a spiral shape in which the number of turns exceeds one turn. The spiral wiring 21 is spirally wound clockwise from the outer peripheral end 21b toward the inner peripheral end 21a when viewed from above.

The thickness of the spiral wiring 21 is preferably larger than the thickness of the insulating layer 15, for example, preferably 40 μm or more and 120 μm or less. As an example of the spiral wiring 21, the thickness is 45 μm, the wiring width is 40 μm, and the space between wires is 10 μm. The space between wirings is preferably 3 μm or more and 20 μm or less.

The spiral wiring 21 is made of a conductive material, for example, a low electrical resistance metal material such as Cu, Ag, or Au. In this embodiment, the inductor component 1 includes only one layer of spiral wiring 21, and the height of the inductor component 1 can be reduced. In other words, the spiral wiring 21 has pad portions at both ends (inner peripheral end 21a and outer peripheral end 21b) whose line width is slightly larger than that of the spiral shaped portion, and is directly connected to the columnar wirings 31 and 32 at the pad portions. There is.

The magnetic layer 10 is formed to cover the first main surface 15a and the second main surface 15b of the insulating layer 15 on which the spiral wiring 21 is formed. The magnetic layer 10 is in contact with at least a portion of the spiral wiring 21, and specifically, in the contact portion with the spiral wiring 21, the magnetic layer 10 is in contact with the spiral wiring 21 from the side surface to the top surface. In particular, in this embodiment, only the bottom surface of the spiral wire 21 is in contact with the insulating layer 15, all the side surfaces of the spiral wire 21 are in contact with the magnetic layer 10, and the top surface of the spiral wire 21 is in contact with the columnar wire 31. , 32 are in contact with the magnetic layer 10. Therefore, the proportion of the insulating layer 15 can be further reduced.

The magnetic layer 10 includes a first magnetic layer 11 , a second magnetic layer 12 , an inner magnetic path section 13 , and an outer magnetic path section 14 . Note that in FIG. 1, a part of the magnetic layer 10 is shown as transparent. The first magnetic layer 11 and the second magnetic layer 12 are located at positions sandwiching the spiral wiring 21 from both sides in the Z direction. Specifically, the first magnetic layer 11 is located above the spiral wiring 21 , and the second magnetic layer 12 is located below the spiral wiring 21 . As shown in FIG. 1, the inner magnetic path section 13 and the outer magnetic path section 14 are arranged inside and outside the spiral wiring 21, respectively, and as shown in FIG. 12. In this way, the magnetic layer 10 forms a closed magnetic path with respect to the spiral wiring 21.

The magnetic layer 10 is made of a magnetic material, for example, a resin containing powder of a magnetic material. Examples of the resin constituting the magnetic layer 10 include epoxy resin, phenol resin, and polyimide resin. Examples of the magnetic material powder include FeSi alloy such as FeSiCr, FeCo alloy, and NiFe. It is a powder of a metal magnetic material such as an Fe-based alloy or an amorphous alloy thereof, or a powder of ferrite. The content of the magnetic material is preferably 50 vol% or more and 85 vol% or less with respect to the entire magnetic layer 10. The particles of the magnetic material powder preferably have a substantially spherical shape, and preferably have an average particle size of 5 μm or less. Furthermore, the magnetic layer 10 may be a ferrite substrate or the like. Note that when the magnetic material is made of resin, it is preferable to use the same material as the insulating layer 15, and in this case, the adhesion between the insulating layer 15 and the magnetic layer 10 can be improved.

The columnar wires 31 and 32 are wires that penetrate inside the magnetic layer 10 in the direction normal to the first main surface 15a of the insulating layer 15. In this embodiment, the first columnar wiring 31 extends upward from the upper surface of the inner peripheral end 21 a of the spiral wiring 21 and penetrates inside the first magnetic layer 11 . The second columnar wiring 32 extends upward from the upper surface of the outer peripheral end 21 b of the spiral wiring 21 and penetrates inside the first magnetic layer 11 . The columnar wirings 31 and 32 are made of the same material as the spiral wiring 21.

The external terminals 41 and 42 are terminals formed outside the magnetic layer 10. In this embodiment, the spiral wiring 21 and the first and second columnar wirings 31 and 32 are in direct contact, the first columnar wiring 31 and the first external terminal 41 are in direct contact, and the second columnar wiring 32 and the second columnar wiring 32 are in direct contact with each other. External terminal 42 is in direct contact. Therefore, since there is no via conductor having a smaller cross-sectional area than the first and second columnar wirings 31 and 32, it is possible to reduce the height of the inductor component 1, reduce Rdc, and improve connection reliability. However, the spiral wiring 21 may be connected to the first and second columnar wirings 31 and 32 via via conductors having a smaller cross-sectional area than the first and second columnar wirings 31 and 32.

The external terminals 41 and 42 are made of a conductive material, such as 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, from the inside to the outside. It has a three-layer configuration arranged in this order.

The first external terminal 41 is provided on the upper surface of the first magnetic layer 11 and covers the end surface of the first columnar wiring 31 exposed from the upper surface. The second external terminal 42 is provided on the upper surface of the first magnetic layer 11 and covers the end surface of the second columnar wiring 32 exposed from the upper surface.

Preferably, the external terminals 41 and 42 are subjected to anti-rust treatment. Here, the rust prevention treatment means coating with Ni and Au, or Ni and Sn, or the like. Thereby, copper eating by solder and rust can be suppressed, and an inductor component 1 with high mounting reliability can be provided.

The coating film 50 is made of an insulating material, covers the upper surface of the first magnetic layer 11 and the lower surface of the second magnetic layer 12, and exposes the end surfaces of the columnar wirings 31, 32 and the external terminals 41, 42. The coating film 50 can ensure insulation on the surface of the inductor component 1. Note that the coating film 50 does not need to be formed on the lower surface side of the second magnetic layer 12.

According to the inductor component 1, the spiral wiring 21 is formed on the first main surface 15a of the insulating layer 15, so that the substrate can be removed (etched) from the second main surface 15b side (lower side) of the insulating layer 15. The spiral wiring 21 is protected against processing processes (such as polishing, polishing, etc.). This makes it possible to suppress an increase in direct current resistance (Rdc) and variations in Rdc during mass production.

Further, since the magnetic layer 10 is in contact with the spiral wiring 21, the proportion of the insulating layer 15 in the entire inductor component 1 is reduced, and a region for forming the spiral wiring 21 and the magnetic layer 10 can be secured. Thereby, the trade-off relationship between inductance (L) and Rdc can be improved.

Therefore, it is possible to realize an inductor component 1 suitable for reduction in size and height.

Further, since the insulating layer 15 does not contain a magnetic material, particularly a magnetic powder, the flatness and insulation properties of the main surfaces 15a and 15b of the insulating layer 15 can be improved. Therefore, it is possible to suppress a decrease in the formation accuracy, insulation properties, and withstand voltage of the spiral wiring 21.

Furthermore, since the columnar wirings 31 and 32 penetrating the inside of the magnetic layer 10 are included, the wirings are drawn out directly from the spiral wiring 21 in the Z direction. This means that the spiral wiring 21 is drawn out to the top surface of the inductor component over the shortest distance, reducing unnecessary wiring routing in three-dimensional mounting where the board wiring is connected from the top surface of the inductor component 1. It means that you can. Therefore, the inductor component 1 has a configuration that can sufficiently accommodate three-dimensional mounting, and the degree of freedom in circuit design can be improved.

Further, in the inductor component 1, since no wiring is drawn out from the spiral wiring 21 in the side direction, the area of the inductor component 1 viewed from the Z direction, that is, the mounting area can be reduced. Therefore, the inductor component 1 can achieve a reduction in the mounting area required for both surface mounting and three-dimensional mounting, and can improve the degree of freedom in circuit design.

Furthermore, in the inductor component 1, the columnar wires 31 and 32 penetrate inside the magnetic layer 10 and extend in the normal direction to the plane around which the spiral wire 21 is wound. In this case, in the columnar wirings 31 and 32, the current does not flow in the direction along the plane around which the spiral wiring 21 is wound, but in the Z direction.

Here, as the size of the inductor component 1 becomes smaller, the magnetic layer 10 also becomes relatively smaller, but the magnetic flux density becomes higher, especially in the inner magnetic path section 13, and magnetic saturation becomes more likely. However, since the magnetic flux caused by the current in the Z direction flowing through the columnar wirings 31 and 32 does not pass through the inner magnetic path section 13, the influence on the magnetic saturation characteristics, that is, the DC superimposition characteristics can be reduced. On the other hand, when the wire is pulled out from the spiral wiring to the side (direction along the plane on which the spiral wiring is wound) by the lead-out part as in the conventional technology, the magnetic flux generated by the current flowing in the lead-out part is Since a part of it passes through the inner magnetic path section and the outer magnetic path section, it is impossible to avoid the influence on the magnetic saturation characteristics and DC superposition characteristics.

Note that since the columnar wirings 31 and 32 penetrate inside the first magnetic layer 11, the opening in the magnetic layer 10 can be made smaller when the wiring is drawn out from the spiral wiring 21, and a closed magnetic circuit structure can be easily obtained. Can be done. Thereby, noise propagation to the substrate side can be suppressed.

Furthermore, since the spiral wiring 21 is wound on a plane along the insulating layer 15, the inner magnetic path portion 13 can be made large even when the thickness is reduced, and the thin inductor component 1 has high magnetic saturation characteristics. can be provided. On the other hand, for example, if an inductor component in which the spiral wiring is wound perpendicularly to the plane along the insulating layer 15 is used, the inductor component can be further thinned, that is, the thickness of the board can be thinned. , the area of the coil diameter (magnetic layer) is reduced. As a result, magnetic saturation characteristics deteriorate, and sufficient current cannot be applied to the inductor.

Furthermore, as shown in FIG. 2, the inductor component 1 includes a coating film 50 that covers the surface of the first magnetic layer 11 or the second magnetic layer 12 and exposes the end faces of the columnar wirings 31 and 32. Here, the above-mentioned "exposure" includes not only the outward exposure of the inductor component 1 but also the exposure to other members.

Specifically, the coating film 50 covers the upper surface of the first magnetic layer 11 except for the external terminals 41 and 42. In this way, the end surfaces of the columnar wirings 31 and 32 connected to the external terminals 41 and 42 are exposed from the coating film 50. Therefore, insulation between adjacent external terminals 41 and 42 (column wirings 31 and 32) can be ensured. Thereby, voltage resistance and environmental resistance of the inductor component 1 can be ensured. Further, depending on the shape of the coating film 50, the formation area of the external terminals 41 and 42 formed on the surface of the magnetic layer 10 can be set arbitrarily, so that the degree of freedom in mounting can be increased, and External terminals 41 and 42 can be easily formed.

Note that in the inductor component 1, as shown in FIG. 2, the surfaces of the external terminals 41 and 42 are located outside the surface of the first magnetic layer 11 in the Z direction. Specifically, the external terminals 41 and 42 are embedded in the coating film 50, and the surfaces of the external terminals 41 and 42 are not flush with the surface of the first magnetic layer 11. At this time, the positional relationship between the surface of the magnetic layer 10 and the surfaces of the external terminals 41 and 42 can be set independently, and the degree of freedom in the thickness of the external terminals 41 and 42 can be increased. According to this configuration, the height position of the surface of the external terminals 41 and 42 in the inductor component 1 can be adjusted. For example, when the inductor component 1 is embedded in a board, the height position of the surface of the external terminals of other embedded components It is possible to match the height position. Therefore, by using the inductor component 1, it is possible to streamline the laser focusing process when forming vias on the substrate, and it is possible to improve the manufacturing efficiency of the substrate.

Furthermore, in the inductor component 1, as shown in FIG. 1, the area of the external terminals 41, 42 that cover the end faces of the columnar wirings 31, 32 is larger than the area of the columnar wirings 31, 32, as seen from the Z direction. Therefore, the bonding area during mounting is increased, and the mounting reliability of the inductor component 1 is improved. Further, when mounting on a board, an alignment margin can be secured for the bonding position between the board wiring and the inductor component 1, and mounting reliability can be improved. At this time, since mounting reliability can be improved regardless of the volume of the columnar wirings 31 and 32, the volume of the first magnetic layer 11 is reduced by reducing the cross-sectional area of the columnar wirings 31 and 32 when viewed from the Z direction. It is possible to suppress a decrease in the characteristics of the inductor component 1, thereby suppressing a decrease in characteristics of the inductor component 1.

The spiral wiring 21, the columnar wiring 31, 32, and the external terminals 41, 42 are preferably conductors made of copper or a copper compound. Thereby, it is possible to provide an inductor component 1 that is inexpensive and can reduce direct current resistance. Furthermore, by using copper as the main material, it is possible to improve the bonding force and conductivity between the spiral wiring 21, the columnar wirings 31 and 32, and the external terminals 41 and 42.

Note that columnar wiring may be provided so as to extend from the spiral wiring to the lower surface of the inductor component. At this time, an external terminal connected to the columnar wiring may be provided on the lower surface of the inductor component.

Although the inductor component 1 has one spiral wire, it is not limited to this configuration, and may include two or more spiral wires wound on the same plane. Since the inductor component 1 has a high degree of freedom in forming the external terminals 41 and 42, this effect is even more pronounced in inductor components with a large number of external terminals.

Spiral wiring is a curve (two-dimensional curve) formed on a plane and has more than one turn, but it may also have less than one turn, or a part of the spiral wiring may have less than one turn. It may have a straight line.

(Production method)
Next, a method for manufacturing the inductor component 1 will be explained.

As shown in FIG. 3A, a substrate 61 is prepared. The substrate 61 is a flat substrate made of, for example, a ceramic material such as glass or ferrite, or a printed wiring board material such as resin containing glass cloth. Since the thickness of the substrate 61 does not affect the thickness of the inductor component, it is sufficient to use a thickness that is easy to handle for reasons such as warping during processing.

As shown in FIG. 3B, an insulating layer 62 containing no magnetic material is formed on a substrate 61. The insulating layer 62 is made of, for example, a polyimide resin that does not contain a magnetic material, and is formed by coating the polyimide resin on the upper surface (first main surface) of the substrate 61 by printing, coating, or the like. Note that the insulating layer 62 may be formed as a thin film of an inorganic material such as a silicon oxide film on the upper surface of the substrate 61 by a dry process such as vapor deposition, sputtering, or CVD.

As shown in FIG. 3C, the insulating layer 62 is patterned by photolithography to leave a region where the spiral wiring will be formed. That is, the insulating layer 62 is removed leaving only the portion along the spiral wiring. The insulating layer 62 is provided with an opening 62a through which the substrate 61 is exposed. As shown in FIG. 3D, a Cu seed layer 63 is formed on the substrate 61, including on the insulating layer 62, by sputtering, electroless plating, or the like.

As shown in FIG. 3E, a dry film resist (DFR) 64 is pasted on the seed layer 63. As shown in FIG. 3F, the DFR 64 is patterned by photolithography to form a through hole 64a in a region where a spiral wiring is to be formed, and the seed layer 63 is exposed from the through hole 64a.

As shown in FIG. 3G, a metal film 65 is formed on the seed layer 63 in the through hole 64a by electrolytic plating. As shown in FIG. 3H, after forming the metal film 65, a DFR 64 is further attached.

As shown in FIG. 3I, the DFR 64 is patterned by photolithography to form a through hole 64a in a region where a columnar wiring is to be formed, and the metal film 65 is exposed from the through hole 64a. As shown in FIG. 3J, a metal film 66 is further formed on the metal film 65 in the through hole 64a by electrolytic plating.

As shown in FIG. 3K, the DFR 64 is removed, and as shown in FIG. 3L, the exposed portion of the seed layer 63 where the metal film 65 is not formed is removed by etching. Thereby, the spiral wiring 21 is formed on the first main surface so as to be wound on the upper surface (first main surface) of the insulating layer 62, and the spiral wiring 21 is formed in the normal direction of the first main surface from the spiral wiring 21. Extending columnar wirings 31 and 32 are formed. That is, the columnar wirings 31 and 32 are formed after the spiral wiring 21 is formed and before the magnetic layer is formed.

As shown in FIG. 3M, a magnetic sheet 67 made of a magnetic material is pressure-bonded to the upper surface side of the substrate 61 (spiral wiring formation side). As a result, the magnetic layer 10 is placed on the insulating layer 15 so as to be in contact with at least a portion of the spiral wiring 21 (other than the side surface of the spiral wiring 21 and the portion that contacts the columnar wirings 31 and 32 on the top surface of the spiral wiring 21). Form.

As shown in FIG. 3N, the magnetic sheet 67 is polished to expose the upper ends of the columnar wirings 31 and 32 (metal film 66). As shown in FIG. 3O, a solder resist (SR) 68 as a coating film 50 is formed on the upper surface (first main surface) of the magnetic sheet 67.

As shown in FIG. 3P, the SR 68 is patterned by photolithography to form a through hole 68a in which the columnar wirings 31 and 32 (metal film 66) and the magnetic layer 10 (magnetic sheet 67) are exposed in the region where the external terminal is to be formed. do.

As shown in FIG. 3Q, the substrate 61 is removed by polishing. As shown in FIG. 3R, a magnetic sheet 67 made of a magnetic material is pressed onto the removal side of the substrate 61 and polished to an appropriate thickness.

As shown in FIG. 3S, a Cu/Ni/Au metal film 69 is formed by electroless plating to grow from the columnar wirings 31 and 32 (metal film 66) into the through hole 68a of the SR 68. The metal film 69 forms a first external terminal 41 connected to the first columnar wiring 31 and a second external terminal 42 connected to the second columnar wiring 32. Further, an SR 68 as a coating film 50 is formed on the lower surface on the opposite side from the external terminals 41 and 42. As shown in FIG. 3T, the inductor component 1 is manufactured by cutting into pieces, performing barrel polishing if necessary, and removing burrs.

According to the method for manufacturing the inductor component 1, the spiral wiring 21 is protected by the insulating layer 15 when the substrate 61 is removed, and an increase in Rdc and variation in Rdc during mass production can be suppressed. Further, since the magnetic layer 10 is in contact with the spiral wiring 21, the ratio of the insulating layer 15 to the entire inductor component 1 is reduced, and the trade-off relationship between L and Rdc can be improved. Therefore, it is possible to manufacture an inductor component 1 suitable for reduction in size and height.

Furthermore, since the insulating layer 15 is removed leaving only the portion along the spiral wiring 21, the proportion of the insulating layer is further reduced.

Further, since the columnar wirings 31 and 32 extending from the spiral wiring 21 are formed and the magnetic layer 10 is formed so that the upper ends of the columnar wirings 31 and 32 are exposed, there is no via conductor, so the height of the inductor component 1 can be reduced. , it is possible to reduce Rdc and improve connection reliability.
Note that the method for manufacturing the inductor component 1 described above is just an example, and the construction methods and materials used in each step may be replaced with other known methods as appropriate. For example, in the above description, the insulating layer 62, DFR 64, and SR 68 are patterned after coating, but the insulating layer 62 may be directly formed in necessary portions by coating, printing, mask vapor deposition, lift-off, or the like. Further, although polishing was used to remove the substrate 61 and thin the magnetic sheet 67, other physical processes such as blasting and laser, or chemical processes such as hydrofluoric acid treatment may be used.

(Example)
Next, an example of the inductor component 1 will be described.

The spiral wiring 21, the columnar wirings 31, 32, and the external terminals 41, 42 are made of a low-resistance metal such as Cu, Ag, or Au. Preferably, by using copper plating formed by SAP (Semi Additive Process), the spiral wiring 21 with low resistance and narrow pitch can be formed at low cost. Note that the spiral wiring 21, the columnar wiring 31, 32, and the external terminals 41, 42 may be formed by a plating method other than SAP, such as a sputtering method, a vapor deposition method, or a coating method.

In this embodiment, the spiral wiring 21 and the columnar wirings 31 and 32 are formed by SAP copper plating, and the external terminals 41 and 42 are formed by electroless Cu plating. Note that the spiral wiring 21, the columnar wirings 31 and 32, and the external terminals 41 and 42 may all be formed by the same method.

The magnetic layer 10 (the first magnetic layer 11, the second magnetic layer 12, the inner magnetic path section 13, and the outer magnetic path section 14) is made of, for example, a resin containing powder of a magnetic material, and is preferably made of approximately spherical metal. Contains magnetic materials. Therefore, the filling property of the magnetic path of the magnetic material can be improved. Thereby, the magnetic path can be made small, and a compact inductor component 1 can be provided. However, the magnetic layer may be a resin containing powder of a magnetic material such as ferrite, or may be a sintered ferrite substrate or a green sheet of a magnetic material.

In this embodiment, the resin constituting the magnetic layer 10 is an organic insulating material made of, for example, epoxy resin, bismaleimide, liquid crystal polymer, or polyimide. Further, the magnetic material powder of the magnetic layer 10 is a metallic magnetic substance with an average particle size of 5 μm or less. The metal magnetic material is, for example, a FeSi-based alloy such as FeSiCr, a FeCo-based alloy, a Fe-based alloy such as NiFe, or an amorphous alloy thereof. The content of the magnetic material is preferably 50 vol% or more and 85 vol% or less based on the entire magnetic layer 10.

As mentioned above, by using a magnetic material with a small average particle size of 5 μm or less, it is possible to suppress the eddy current generated in the metal magnetic material, and the inductor component 1 has low loss even at high frequencies of several tens of MHz. can be obtained.

Furthermore, by using an Fe-based magnetic material, it is possible to obtain greater magnetic saturation characteristics than ferrite or the like.

In addition, by increasing the filling amount of magnetic material to 50 vol% or more, magnetic permeability can be increased, and the number of turns of spiral wiring required to obtain the desired inductance value can be reduced. loss can be reduced. Furthermore, when the filling amount is 85 vol% or less, the volume of the organic insulating resin is sufficiently large compared to the magnetic material, and the fluidity of the magnetic material can be ensured, so the filling property is improved and the effective magnetic permeability and the magnetic material itself are improved. Strength can be improved.

On the other hand, when used at low frequencies, there is no need to be concerned about eddy current loss as it is at high frequencies, so the average particle size of the metal magnetic material may be increased to provide higher magnetic permeability. For example, it is preferable to use a magnetic material in which large particles with an average particle size of 100 to 30 μm and some small particles (10 μm or less) coexist so as to fill the gaps between the large particles. By doing so, the filling amount can be increased and a magnetic material with high magnetic permeability at frequencies such as 1 to 10 MHz can be realized. However, at frequencies of 1 MHz or higher, the relative magnetic permeability is preferably 70 or lower in order to suppress the influence of eddy current loss.

In this embodiment, the coating film 50 is formed of a photosensitive resist or solder resist made of an organic insulating resin such as polyimide, phenol, or epoxy resin.

Furthermore, the antirust treatment applied to the surfaces of the external terminals 41 and 42 is plating with Ni, Au, Sn, or the like.

The insulating layer 15 is made of an insulating resin that does not contain a magnetic material, particularly a magnetic powder. Therefore, since it does not contain a magnetic material having a grain size of, for example, 5 μm, the flatness and insulation properties of the main surfaces 15a and 15b of the insulating layer 15 can be improved. Therefore, it is possible to suppress a decrease in the formation accuracy, insulation properties, and withstand voltage of the spiral wiring 21. Further, since the spiral wiring 21 is not covered with the insulating layer 15, the inductance value can be increased by increasing the volume of the magnetic material considering the same chip size. The thickness of the insulating layer 15 is preferably thinner than the spiral wiring 21, and the thickness of the insulating layer 15 is preferably 10 μm or less.

In this example, the thickness of the spiral wiring 21 is 45 μm, the wiring width is 40 μm, and the space between the wires is 10 μm.

Note that the space between wirings is preferably 3 μm or more and 20 μm or less. By setting the inter-wiring space to 20 μm or less, the wiring width can be increased, and the direct current resistance can be lowered. By setting the space between the wires to 3 μm or more, sufficient insulation between the wires can be maintained.

Moreover, the wiring thickness is preferably 40 μm or more and 120 μm or less. By setting the wiring thickness to 40 μm or more, the direct current resistance can be sufficiently lowered. By setting the wiring thickness to 120 μm or less, the wiring aspect does not become extremely large, and process variations can be suppressed.

In this embodiment, the number of turns of the spiral wiring 21 is 2.5 turns. The number of turns is preferably 5 turns or less. If the number of turns is 5 or less, the loss due to the proximity effect can be reduced for high frequency switching operations from 50 MHz to 150 MHz. On the other hand, when used in low frequency switching operation such as 1 MHz, 2.5 turns or more is preferable. By increasing the number of turns, the inductance can be increased and the inductor ripple current can be reduced.

In this embodiment, the thickness of the first magnetic layer 11 is 117.5 μm, and the thickness of the second magnetic layer 12 is 67.5 μm. The thickness of the first magnetic layer 11 and the second magnetic layer 12 is preferably 10 μm or more and 200 μm or less, respectively. If the thickness of the first and second magnetic layers 11 and 12 is too thin, the spiral wiring 21 may be exposed due to process variations during grinding of the first and second magnetic layers 11 and 12. Further, when the thickness of the first and second magnetic layers 11 and 12 is thinner than the average grain size of the magnetic material contained in the first and second magnetic layers 11 and 12, the effective magnetic permeability decreases significantly due to grain shedding. By setting the thickness of the first and second magnetic layers 11 and 12 to 200 μm or less, the inductor component can be made thinner.

Further, the thickness of the first magnetic layer 11 is preferably thicker than the thickness of the second magnetic layer 12. In the inductor component 1, the first magnetic layer 11 is larger than the second magnetic layer 12 in terms of the area of the external terminals 41 and 42 when viewed from the normal direction (Z direction). That is, in the inductor component 1, the magnetic flux in the first magnetic layer 11 is more easily blocked by the external terminals 41 and 42 than the magnetic flux in the second magnetic layer 12. Therefore, by increasing the thickness on the first magnetic layer 11 side and increasing the distance from the external terminals 41 and 42 to reduce the influence of the external terminals 41 and 42, it is possible to reduce the variation in the magnetic layer thickness (chip thickness) of the inductance. It is possible to reduce sensitivity and provide an inductor component having inductance with narrow deviation. Additionally, in general, the area of the land pattern on the side of the substrate where the inductor component 1 is mounted and built in is larger on the first magnetic layer 11 side where the external terminals 41 and 42 have a larger area, and the number of surrounding electronic components is also larger. Cheap. Therefore, by increasing the thickness of the first magnetic layer 11 to reduce magnetic flux leakage, it is possible to effectively reduce the negative effects of magnetic flux leakage, such as eddy current loss due to the land pattern and noise input to surrounding electronic components. Can be done.

The thickness of the external terminals 41 and 42 including anti-rust treatment is 5 μm thick for electroless copper plating, 5 μm thick for Ni plating, and 0.1 μm thick for Au plating. Further, the thickness of the coating film 50 is 5 μm. These thicknesses and sizes may be selected from the viewpoint of convenient chip thickness and mounting reliability.

As described above, according to this embodiment, a thin inductor having a chip size of 1210 (1.2 mm x 1.0 mm) and a thickness of 0.300 mm can be provided.

(Second embodiment)
FIG. 4 is a cross-sectional view showing a second embodiment of the inductor component. The second embodiment differs from the first embodiment in the arrangement of insulating layers. This different configuration will be explained below. The other configurations are the same as those in the first embodiment, are given the same reference numerals as in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 4, in the inductor component 1A of the second embodiment, the spiral wiring 21 has a spiral shape having more than one turn. In a region where the wires run parallel to each other over one circumference of the spiral wire 21, the side surfaces of the spiral wire 21 are covered with an insulating layer 15. That is, the insulating layer 15 covers the lower surface of the spiral wiring 21 as in the first embodiment, and further exists between the wirings of the spiral wiring 21 in a region exceeding one circumference. Note that the thickness of the insulating layer 15 existing between the wires of the spiral wire 21 may be the same as the wire thickness of the spiral wire 21, or may be larger or smaller than the wire thickness of the spiral wire 21.

Thereby, when the space between the spiral wiring lines 21 is narrow, it is possible to eliminate the possibility that an electrical short circuit path is created between the spiral wiring lines 21 via a magnetic material such as a magnetic metal. Therefore, the insulation and voltage resistance of the spiral wiring 21 can be improved, and a highly reliable inductor component 1A can be provided.

Note that in areas where the wires of the spiral wire 21 do not run parallel to each other, for example, at both ends of the spiral wire 21, on the outer side surface of the outermost periphery of the spiral wire 21, and on the inner side surface of the innermost periphery of the spiral wire 21, the spiral wire The side surface of 21 may be covered with the insulating layer 15 or may be in direct contact with the magnetic layer 10 .

To explain the method for manufacturing the inductor component 1A, for example, after the step shown in FIG. 3L of the first embodiment, an insulating layer 15 may be provided between the spiral wires 21.

(Third embodiment)
FIG. 5 is a cross-sectional view showing a third embodiment of the inductor component. The third embodiment differs from the first embodiment in the number of layers of spiral wiring. This different configuration will be explained below. The other configurations are the same as those in the first embodiment, are given the same reference numerals as in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 5, the inductor component 1B of the second embodiment is formed on the insulating layers 15A, 15B and the first main surface 15a of the insulating layers 15A, 15B, similarly to the inductor component 1 of the first embodiment. spiral wirings 21 and 22, and a magnetic layer 10 that contacts at least a portion of the spiral wirings 21 and 22.

On the other hand, in the inductor component 1B, the spiral wiring includes a plurality of first spiral wirings 21 and second spiral wirings 22, and further includes a via conductor that connects the first spiral wiring 21 and the second spiral wiring 22 in series. . Two layers of spiral wiring 21 and 22 are electrically connected in series between first and second external terminals 41 and 42.

Specifically, the second spiral wiring 22 is stacked in the Z direction (above) the first spiral wiring 21. The first spiral wiring 21 is spirally wound in a counterclockwise direction from an outer peripheral end 21b toward an inner peripheral end 21a when viewed from above. The second spiral wiring 22 is spirally wound in a counterclockwise direction from an inner peripheral end 22a toward an outer peripheral end 22b when viewed from above.

The first spiral wiring 21 is formed on the first main surface 15a of the first insulating layer 15A. The second spiral wiring 22 is formed on the first main surface 15a of the second insulating layer 15B. The second insulating layer 15B is stacked in the Z direction (above) the first insulating layer 15A.

The outer peripheral end 22b of the second spiral wiring 22 is connected to the second external terminal 42 via the second columnar wiring 32 above the outer peripheral end 22b. The inner peripheral end of the second spiral wiring 22 is connected to the inner peripheral end of the first spiral wiring 21 via a via conductor below the inner peripheral end. The via conductor penetrates the inside of the second insulating layer 15B in the normal direction of the first main surface 15a.

The outer peripheral end 21b of the first spiral wiring 21 is connected to the first external terminal 41 via the via conductor 25, the end wiring 26, and the first columnar wiring 31 above the outer peripheral end 21b. The via conductor 25 penetrates the inside of the second insulating layer 15B in the normal direction of the first main surface 15a. The end wiring 26 is formed on the second insulating layer 15B on the same plane as the second spiral wiring 22.

In the inductor component 1B, since the first spiral wiring 21 and the second spiral wiring 22 are connected in series, the inductance value can be improved by increasing the number of turns. Furthermore, since the first and second columnar wirings 31 and 32 can be drawn out from the outer peripheral ends of the first and second spiral wirings 21 and 22, it is possible to increase the inner diameter of the first and second spiral wirings 21 and 22. It is possible to improve the inductance value.

Furthermore, since the first spiral wiring 21 and the second spiral wiring 22 are laminated in the normal direction, the area of the inductor component 1B seen from the Z direction, that is, the mounting area, can be reduced relative to the number of turns, and the inductor component Miniaturization of 1B can be achieved.

Note that the spiral wiring is not limited to two layers, and may have multiple layers. Further, the spiral wiring on the upper layer side may be formed on the magnetic layer instead of on the insulating layer because it is not affected by processing processes such as substrate removal from below (etching, polishing). Specifically, in the configuration of FIG. 5, the insulating layer 15B may not exist, and the magnetic layer 10 may be arranged instead. Further, in the region where the wires of the first spiral wire 21 run parallel to each other as in the second embodiment, the side surface of the first spiral wire 21 is covered with the insulating layer 15 (insulating layer 15B). Good too. In this case, the first spiral wiring 21 contacts the magnetic layer 10 on the inner side surface.

To explain the method for manufacturing the inductor component 1B, a substrate is prepared, a first insulating layer 15A is formed on the substrate, and a first spiral wiring 21 is formed on the first main surface 15a of the first insulating layer 15A. , the magnetic layer 10 is formed so as to contact at least a portion of the first spiral wiring 21, specifically, the side surface of the first spiral wiring 21. Furthermore, after polishing the magnetic layer 10 to expose the upper surface of the first spiral wiring 21, a second insulating layer 15B is formed on the first spiral wiring 21 and the magnetic layer 10, and a second insulating layer 15B is formed on the first spiral wiring 21 and on the magnetic layer 10. A second spiral wiring 22 is formed on the first main surface 15a of the layer 15B, and the magnetic layer 10 is formed in contact with at least a portion of the second spiral wiring 22. After that, the substrate is removed.

(Fourth embodiment)
FIG. 6 is a transparent perspective view showing a fourth embodiment of the inductor component. FIG. 7 is a sectional view taken along line XX in FIG. The fourth embodiment differs from the first embodiment in the configuration of the spiral wiring. This different configuration will be explained below. Note that in the fourth embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so the explanation thereof will be omitted.

As shown in FIGS. 6 and 7, the inductor component 1C includes an insulating layer 15 and spiral wirings 21B to 21B formed on the first main surface 15a of the insulating layer 15, similarly to the inductor component 1 of the first embodiment. 24B, and a magnetic layer 10 that contacts at least a portion of each of the spiral wirings 21B to 24B.

On the other hand, in the inductor component 1C, the first spiral wiring 21B, the second spiral wiring 22B, the third spiral wiring 23B, and the fourth spiral wiring 24B have a semi-elliptical arc shape when viewed from the Z direction. That is, the first to fourth spiral wires 21B to 24B are curved wires wound approximately half a turn. Further, the spiral wirings 21B to 24B include a straight portion in the middle portion. As described above, in the present disclosure, "spiral wiring wound in a planar shape" refers to a curve formed in a planar shape (two-dimensional curve), even if the number of turns is less than one round. In some cases, it may have a straight portion.

The first and fourth spiral wirings 21B and 24B are connected at both ends to a first columnar wiring 31 and a second columnar wiring 32 located outside, and are connected to the inductor component 1C from the first columnar wiring 31 and the second columnar wiring 32. It has a curved shape that draws an arc toward the center.

The second and third spiral wirings 22B and 23B are connected at both ends to the first columnar wiring 31 and the second columnar wiring 32 located inside, and are connected to the inductor component 1C from the first columnar wiring 31 and the second columnar wiring 32. It has a curved shape that draws an arc toward the veranda.

Here, in each of the first to fourth spiral wirings 21B to 24B, the range surrounded by the curve drawn by the spiral wirings 21B to 24B and the straight line connecting both ends of the spiral wirings 21B to 24B is defined as an inner diameter portion. At this time, when viewed from the Z direction, the inner diameter portions of any of the spiral wires 21B to 24B do not overlap.

On the other hand, the first and second spiral wirings 21B and 22B are close to each other. That is, the magnetic flux generated in the first spiral wiring 21B goes around the adjacent second spiral wiring 22B, and the magnetic flux generated in the second spiral wiring 22B goes around the adjacent first spiral wiring 21B. This also applies to the third and fourth spiral wirings 23B and 24B, which are close to each other. Therefore, the magnetic coupling between the first spiral wiring 21B and the second spiral wiring 22B and the magnetic coupling between the third spiral wiring 23B and the fourth spiral wiring 24B become stronger.

Note that in the first and second spiral wirings 21B and 22B, when current flows simultaneously from one end on the same side to the other end on the opposite side, the mutual magnetic fluxes are strengthened. This means that if one end of the first spiral wiring 21B and the second spiral wiring 22B on the same side are both input sides for a pulse signal, and each other end on the opposite side is set as an output side of a pulse signal, This means that the first spiral wiring 21B and the second spiral wiring 22B are positively coupled. On the other hand, for example, in one of the first spiral wiring 21B and the second spiral wiring 22B, one end is an input and the other end is an output, and the other spiral wiring has one end as an output and the other end as an input. For example, the first spiral wiring 21B and the second spiral wiring 22B can be negatively coupled. This also applies to the third and fourth spiral wirings 23B and 24B.

The first columnar wiring 31 connected to one end side of the first and third spiral wirings 21B and 23B, and the second columnar wiring 32 connected to the other end side of the second and fourth spiral wirings 22B and 24B, Each of them penetrates the inside of the first magnetic layer 11 and is exposed on the upper surface. A second columnar wiring 32 is connected to the other end of the first and third spiral wirings 21B and 23B via a via conductor 25, and a via conductor 25 is connected to one end of the second and fourth spiral wirings 22B and 24B. The first columnar wirings 31 connected thereto penetrate through the inside of the second magnetic layer 12 and are exposed at the bottom surface. Via conductor 25 penetrates inside insulating layer 15 . The first columnar wiring 31 is connected to the first external terminal 41. The second columnar wiring 32 is connected to the second external terminal 42 .

According to this configuration, for example, the inductor component 1C is embedded in the substrate, the pulse signal input line is arranged on the upper surface side of the first magnetic layer 11, and the pulse signal output line is arranged on the lower surface side of the second magnetic layer 12. By arranging them, each of the set of first and second spiral wirings 21B and 22B and the set of third and fourth spiral wirings 23B and 24B can be more easily negatively coupled.

In addition, in the inductor component 1C, the wiring further extends toward the outside of the chip from the connection position with the columnar wirings 31 and 32 of the spiral wirings 21B to 24B, but this is because additional copper is added after forming the copper wiring in SAP. This is the wiring that is connected to the power supply wiring when performing electrolytic plating. With this power supply wiring, even if the SAP power supply film is removed, additional copper electrolytic plating can be easily performed, and the distance between the wirings can be narrowed. In addition, by performing additional copper electrode plating after SAP formation, the distance between the first and second spiral wirings 21B and 22B and the distance between the third and fourth spiral wirings 23B and 24B can be reduced, resulting in high magnetic coupling. can be obtained.

Note that the number of spiral wires is not limited to four, and may be one to three, or five or more. Further, both ends of the spiral wiring may be connected to columnar wiring that penetrates the magnetic layer on the same side of the magnetic layer, or at one end, a columnar wiring that penetrates the magnetic layer on the first main surface side, It may be connected to both columnar wirings penetrating the magnetic layer on the second main surface side.

To explain the method for manufacturing the inductor component 1C, a substrate is prepared, an insulating layer 15 is formed on the substrate, and spiral wirings 21B to 24B and spiral wirings 21B to 24B are formed on the first main surface 15a of the first insulating layer 15. A first columnar wiring 31 is formed on one end of the spiral wiring 24B, and a magnetic layer 10 is formed so as to contact at least a portion of each of the spiral wirings 21B to 24B. After that, the substrate is removed. Further, an opening is made in the first insulating layer 15 below the other end of the spiral wirings 21B to 24B from the second main surface 15b side using a laser drill or the like, and a via conductor 25 and a second columnar wiring 32 are formed. Then, the magnetic layer 10 is formed on the second main surface 15b side of the first insulating layer 15, and the first columnar wiring 31 and the second columnar wiring 32 are exposed by polishing the magnetic layer 10 from the upper side and the lower side, After the coating film 50 is formed and opened, the first external terminal 41 and the second external terminal 42 may be formed.

Note that the present disclosure is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present disclosure. For example, the features of the first to fourth embodiments may be combined in various ways.

The magnetic layer may contact only the side surface of the spiral wiring at the contact portion with the spiral wiring, or the magnetic layer may contact only the top surface of the spiral wiring at the contact portion with the spiral wiring. good. Even in these cases, the proportion of the insulating layer can be reduced compared to a structure in which the side and top surfaces of the spiral wiring are covered with an insulating layer.

1, 1A, 1B, 1C Inductor parts 10 Magnetic layer 11 First magnetic layer 12 Second magnetic layer 13 Inner magnetic path section 14 Outer magnetic path section 15 Insulating layer 15A First insulating layer 15B Second insulating layer 15a First main surface 15b Second main surface 21 First spiral wiring 22 Second spiral wiring 21B First spiral wiring 22B Second spiral wiring 23B Third spiral wiring 24B Fourth spiral wiring 25 Via conductor 26 End wiring 31 First columnar wiring 32 Second Columnar wiring 41 First external terminal 42 Second external terminal 50 Covering film 61 Substrate

Claims (9)

an insulating layer that does not contain magnetic material;
a spiral wiring formed on a first main surface of the insulating layer and wound on the first main surface;
a magnetic layer in contact with a part of the spiral wiring,
The spiral wiring has only one layer,
The number of turns of the spiral wiring is less than one turn, and the spiral wiring includes a straight portion in the middle portion,
The insulating layer has a shape that follows the spiral wiring and a shape that corresponds to the lower surface of the spiral wiring ,
The magnetic layer is in contact with the spiral wiring from a side surface to an upper surface at a contact portion with the spiral wiring . The inductor component according to claim 1 , wherein the thickness of the insulating layer is thinner than the thickness of the spiral wiring. The inductor component according to claim 2 , wherein the insulating layer has a thickness of 10 μm or less. further comprising: a columnar wiring penetrating the inside of the magnetic layer in a direction normal to the first main surface; and an external terminal formed outside the magnetic layer;
The inductor component according to claim 1, wherein the spiral wiring and the columnar wiring are in direct contact with each other, and the columnar wiring and the external terminal are in direct contact with each other. 5. The inductor component according to claim 1, wherein all side surfaces of the spiral wiring are in contact with the magnetic layer. 5. The inductor component according to claim 4 , wherein the entire upper surface of the spiral wiring contacts the magnetic layer except for the portion that contacts the columnar wiring. a step of preparing a substrate;
forming an insulating layer containing no magnetic material on the substrate;
A spiral wiring having only one layer on the first main surface and having a number of turns less than one turn and including a straight portion on the first main surface so as to be wound on the first main surface of the insulating layer. A process of forming wiring,
forming a magnetic layer on the insulating layer so as to contact a part of the spiral wiring;
and a step of removing the substrate,
The insulating layer has a shape that follows the spiral wiring and a shape that corresponds to the lower surface of the spiral wiring ,
The method for manufacturing an inductor component, wherein the magnetic layer is in contact with the spiral wiring from a side surface to an upper surface at a contact portion with the spiral wiring. 8. The method for manufacturing an inductor component according to claim 7 , wherein the insulating layer is removed leaving a portion along the spiral wiring. After the spiral wiring is formed and before the magnetic layer is formed, a columnar wiring is formed extending from the spiral wiring in the normal direction of the first main surface, and the magnetic layer is formed so that the upper end of the columnar wiring is exposed. The method for manufacturing an inductor component according to claim 7 or 8 .

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