阅读说明：本技术 电感部件和电感部件的制造方法 (Inductance component and method for manufacturing inductance component ) 是由 今枝大树 吉冈由雅 山本和志 于 2021-05-31 设计创作，主要内容包括：本发明在于能够抑制电感部件制造时、安装时进行的外观检查的精度的降低。电感部件(10)具备：主体(BD),其包括磁性层(20)；电感布线(40),其设置于主体(BD)内；以及垂直布线(60),其与电感布线(40)连接,并且从与电感布线(40)连接的连接部分延伸至主体(BD)的第1主面(21)。主体(BD)的第2主面(22)位于隔着电感布线(40)而与第1主面(21)相反一侧。第1主面(21)由绝缘性的第1表层(31)覆盖,并且第2主面(22)由绝缘性的第2表层(32)覆盖。第1表层(31)和第2表层(32)分别含有着色剂。(The invention aims to suppress the reduction of the precision of appearance inspection when manufacturing and mounting an inductance component. An inductance component (10) is provided with: a main Body (BD) including a magnetic layer (20); an inductance wiring (40) provided in the main Body (BD); and a vertical wiring (60) which is connected to the inductance wiring (40) and extends from a connection portion connected to the inductance wiring (40) to the 1 st main surface (21) of the main Body (BD). The 2 nd main surface (22) of the Body (BD) is located on the opposite side of the 1 st main surface (21) with the inductance wiring (40) therebetween. The 1 st main surface (21) is covered by an insulating 1 st surface layer (31), and the 2 nd main surface (22) is covered by an insulating 2 nd surface layer (32). The 1 st skin layer (31) and the 2 nd skin layer (32) each contain a colorant.)

1. An inductance component, comprising:

a body including a magnetic layer and having a1 st major surface and a2 nd major surface;

an inductor wiring provided in the main body; and

a vertical wiring connected to the inductance wiring and extending from a connection portion connected to the inductance wiring to the 1 st main surface,

the 2 nd main surface is located on the opposite side of the 1 st main surface with the inductor wiring interposed therebetween,

the 1 st main surface is coated with an insulating 1 st surface layer, and the 2 nd main surface is coated with an insulating 2 nd surface layer,

the 1 st skin layer and the 2 nd skin layer each contain a colorant.

2. The inductive component of claim 1,

the 1 st skin layer is a different color than the 2 nd skin layer.

3. Inductive component according to claim 1 or 2,

the first skin layer contains a colorant that is different from the colorant contained in the second skin layer.

4. An inductive component according to any one of claims 1 to 3,

the 1 st surface layer covers only the 1 st main surface out of the side surfaces of the main body.

5. The inductive component according to any of claims 1 to 4,

the 2 nd surface layer covers only the 2 nd main surface out of the side surfaces of the main body.

6. The inductive component according to any one of claims 1 to 5,

at least one of the 1 st skin layer and the 2 nd skin layer includes an inorganic filler.

7. The inductive component according to any one of claims 1 to 6,

the interval between the 1 st main surface and the 2 nd main surface is 0.3mm or less,

the magnetic layer contains at least one of iron and an alloy containing iron as a magnetic powder,

the average particle diameter of the magnetic powder is 1-5 [ mu ] m.

8. The inductive component according to any of claims 1 to 7,

the thickness of the 1 st surface layer is 3 μm or more and 10 μm or less.

9. The inductive component according to any one of claims 1 to 8,

the 2 nd skin layer is thinner than the 1 st skin layer.

10. The inductive component according to any one of claims 1 to 9,

the 2 nd surface layer has higher shielding property than the 1 st surface layer.

11. The inductive component according to any one of claims 1 to 10,

the content of the colorant per unit volume of the 2 nd skin layer is greater than the content of the colorant per unit volume of the 1 st skin layer.

12. The inductive component according to any one of claims 1 to 11,

the 2 nd skin layer comprises a black colorant.

13. The inductive component according to any one of claims 1 to 12,

at least one of the 1 st surface layer and the 2 nd surface layer has a surface roughness of 2 μm or less.

14. The inductance component according to any one of claims 1 to 13,

the inductance component is provided with external terminals which are connected to the vertical wirings and are exposed at the 1 st surface layer,

the external terminal is in contact with both the main body and the 1 st surface layer.

15. The inductive component of claim 14,

the external terminal is a laminated body in which a plurality of layers are laminated,

the laminate includes a layer having a copper ratio of 99 wt% or less and a nickel ratio of 0.1 wt% or more.

16. The inductive component of claim 14,

the external terminal is a laminated body in which a plurality of layers are laminated,

the laminate includes a layer containing a displacement catalyst.

17. A method for manufacturing an inductance component having inductance wiring provided in a body including a magnetic layer, the method comprising:

forming the inductance wiring;

forming a vertical wiring connected to the inductance wiring;

forming the main body such that the inductance wiring and the vertical wiring are provided in the main body and the vertical wiring reaches a1 st main surface of the main body;

providing an insulating 1 st surface layer containing a colorant on the 1 st main surface; and

and a step of providing an insulating 2 nd surface layer containing a colorant on the 2 nd main surface, when the 2 nd main surface is a main surface located on the opposite side of the 1 st main surface with the inductance wiring interposed therebetween, among the main surfaces of the main body.

Technical Field

The present invention relates to an inductance component and a method of manufacturing the inductance component.

Background

Patent document 1 describes an example of an inductance component, which includes: the inductor includes a body having a magnetic layer and an inductor wiring disposed within the body. The main body has a1 st main surface and a2 nd main surface, and the 2 nd main surface is located on the opposite side of the 1 st main surface with the inductor wiring interposed therebetween. In addition, a1 st vertical wiring extending from a connecting portion connected to the inductance wiring to the 1 st main surface and a2 nd vertical wiring extending from a connecting portion connected to the inductance wiring to the 2 nd main surface are provided in the main body.

The side surface of the main body of the inductance component including the 1 st main surface and the 2 nd main surface is covered with an insulating surface layer.

Patent document 1: japanese patent No. 6024243

The surface of the surface layer of the inductor member covering the main body may be polished. There is a damage caused by polishing at this time, that is, a polishing mark remains on the surface of the surface layer. Further, if an irregularly shaped scratch such as a grinding mark remains on the surface, the accuracy of the appearance inspection performed during the manufacture and mounting of the inductance component may be reduced.

Disclosure of Invention

An inductance component according to an aspect of the present disclosure includes: a body including a magnetic layer and having a1 st major surface and a2 nd major surface; an inductor wiring provided in the main body; and a vertical wiring connected to the inductance wiring and extending from a connection portion connected to the inductance wiring to the 1 st main surface. The 2 nd main surface is located on the opposite side of the 1 st main surface with the inductor wiring interposed therebetween. The 1 st main surface is covered with an insulating 1 st surface layer, and the 2 nd main surface is covered with an insulating 2 nd surface layer. The 1 st skin layer and the 2 nd skin layer each contain a colorant.

According to the above configuration, the 1 st surface layer of the 1 st main surface of the coated body and the 2 nd surface layer of the 2 nd main surface of the coated body contain the colorant, respectively. Therefore, even when scratches having an irregular shape remain on the surface of the 1 st surface layer or the 2 nd surface layer when polishing or the like is applied, the scratches are not conspicuous. This flaw is less likely to affect the accuracy of the appearance inspection performed during the manufacture and mounting of the inductance component.

A manufacturing method according to one aspect of the present disclosure is a manufacturing method of an inductance component in which an inductance wiring is provided in a body including a magnetic layer. The manufacturing method comprises: forming the inductance wiring; forming a vertical wiring in connection with the inductance wiring; forming the main body such that the inductance wiring and the vertical wiring are provided in the main body and the vertical wiring reaches a1 st main surface of the main body; a step of providing an insulating 1 st surface layer containing a colorant on the 1 st main surface; and a step of providing an insulating 2 nd surface layer containing a colorant on the 2 nd main surface when a main surface of the main body located on a side opposite to the 1 st main surface with the inductance wiring interposed therebetween is set as the 2 nd main surface.

According to the inductance component manufactured by the manufacturing method, the same effect as the inductance component can be obtained.

According to the inductance component and the method for manufacturing the inductance component, the accuracy of the appearance inspection performed at the time of manufacturing or mounting the inductance component can be suppressed from being lowered.

Drawings

Fig. 1 is a perspective view schematically showing an embodiment of an inductance component.

Fig. 2 is a cross-sectional view of the inductive component.

Fig. 3 is a cross-sectional view of the inductive component.

Fig. 4 is a partially enlarged cross-sectional view of the inductance component.

Fig. 5 is a flowchart illustrating an embodiment of a method for manufacturing an inductance component.

Fig. 6 is an explanatory view of the manufacturing method.

Fig. 7 is an explanatory view of the manufacturing method.

Fig. 8 is an explanatory view of the manufacturing method.

Fig. 9 is an explanatory view of the manufacturing method.

Fig. 10 is an explanatory view of the manufacturing method.

Fig. 11 is an explanatory view of the manufacturing method.

Fig. 12 is an explanatory view of the manufacturing method.

Fig. 13 is an explanatory view of the manufacturing method.

Fig. 14 is an explanatory view of the manufacturing method.

Fig. 15 is an explanatory view of the manufacturing method.

Fig. 16 is an explanatory view of the manufacturing method.

Fig. 17 is an explanatory view of the manufacturing method.

Fig. 18 is an explanatory view of the manufacturing method.

Fig. 19 is a cross-sectional view schematically showing an inductance component according to a modification.

Fig. 20 is a sectional view of the inductance component.

Fig. 21 is a partially enlarged cross-sectional view of an inductance component according to a modification.

Description of the reference numerals

10. 10a … inductive component; 20 … a magnetic layer; 21 … major face 1; 22 … major face 2; 31. 31a … skin layer 1; 311 … surface; 32. 32a … skin layer No. 2; 321 …; 40. 40A, 40B … inductive wiring; 60. 60A1, 60A2, 60B1, 60B2 … vertical wiring; 70 … external terminals; 71-73 … layers; BD … main body.

Detailed Description

Hereinafter, an embodiment of an inductance component and a method of manufacturing the inductance component will be described with reference to fig. 1 to 18. In addition, the drawings may show the components in an enlarged manner for easy understanding. The size ratio of the constituent elements may be different from the actual case or from those in other drawings. Note that, although hatching is indicated in the cross-sectional view, hatching may be omitted in some cases to facilitate understanding of some of the constituent elements.

As shown in fig. 1, the main body BD of the inductance component 10 includes a magnetic layer 20 made of a magnetic material. The magnetic layer 20 contains magnetic powder. The average particle diameter of the magnetic powder contained in the magnetic layer 20 is preferably "1 μm" or more and "5 μm" or less. The average particle diameter referred to herein is, for example, the intermediate diameter "D50".

The following methods are examples of the method for measuring the average particle diameter. In a cross section passing through the center of the main body BD as shown in fig. 3, images of cross sections of the magnetic layer 20 including 30 or more particles of magnetic powder are acquired at 3 locations different from each other. An image of the cross section is acquired by SEM (scanning electron microscope) with the magnification adjusted to an appropriate size (for example, 1000 times). Then, from the above image, the particle diameter of the magnetic powder was calculated as a converted value based on the area. The value (cumulative 50%) located at the center of each particle diameter in ascending order is the average particle diameter.

The magnetic layer 20 is made of, for example, a resin containing metal magnetic powder. In the case where the magnetic layer 20 is composed of a resin containing a metal magnetic powder, the magnetic layer 20 preferably contains at least one of iron and an alloy containing iron as the metal magnetic powder.

The magnetic layer 20 may contain a metal magnetic powder other than iron-based metals such as iron and alloys containing iron. Examples of the metal magnetic powder other than the iron-based metal include nickel, chromium, copper, aluminum, and alloys thereof. In the case where the magnetic layer 20 contains magnetic powder of a metal other than an iron-based metal, the magnetic layer 20 may further contain magnetic powder of an iron-based metal, or may not contain magnetic powder of an iron-based metal.

The magnetic layer 20 preferably contains "60 wt% (mass%) or more of metal magnetic powder with respect to the total weight thereof. In order to improve the filling property of the resin containing the metal magnetic powder, it is further preferable to contain two or three kinds of metal magnetic powder having different particle size distributions in the resin.

Examples of the resin containing the metal magnetic powder include resin materials such as epoxy resins. In consideration of insulation properties and moldability, a polyimide resin, an acrylic resin, or a phenol resin is preferably used as the resin.

The magnetic layer 20 may be made of a resin containing ferrite powder instead of the metal magnetic powder, or may be made of a resin containing both the metal magnetic powder and the ferrite powder. For example, the magnetic layer 20 may be a sintered body of ferrite, which is a substrate solidified by sintering ferrite powder.

In the example shown in fig. 1, the main body BD has a rectangular parallelepiped shape. The shape of the main body BD is not limited to a rectangular parallelepiped, and may be, for example, a cylindrical shape or a polygonal shape. The upper surface of fig. 3 of the side surface of the main body BD is referred to as "1 st main surface 21". Of the side surfaces of the main body BD, the main surface located on the opposite side of the 1 st main surface 21 with the inductance line 40 described later interposed therebetween is referred to as a "2 nd main surface 22". The portion of the side surface of the main body BD other than the 1 st main surface 21 and the 2 nd main surface 22 is referred to as a "non-main surface 23". That is, the side surface of the main body BD includes the 1 st main surface 21, the 2 nd main surface 22, and the non-main surface 23.

As shown in fig. 3, when the vertical direction in the drawing, which is the direction perpendicular to the 1 st main surface 21, is taken as the thickness direction X1, and the dimension of the main body BD in the thickness direction X1 is taken as the thickness T1 of the main body BD, the thickness T1 of the main body BD is "0.15 mm" or more and "0.3 mm" or less. In other words, the interval between the 1 st main surface 21 and the 2 nd main surface 22 is "0.15 mm" or more and "0.3 mm" or less. For example, in the cross section of the main body BD shown in fig. 3, the average value of the thicknesses measured at 3 positions at the center and both ends in the longitudinal direction thereof is derived as the thickness T1 of the main body BD.

As described above, the inductance component 10 is very thin. For example, the aspect ratio, which is a value obtained by dividing the area of the surface (upper surface in the drawing) of the 1 st main surface 21 by the thickness T1 of the main body BD, is less than "0.5". For example, when the length of the 1 st main surface 21 in the left-right direction in fig. 3 is "1.2 mm", and the length of the 1 st main surface 21 in the direction perpendicular to the paper surface in fig. 3 is "0.6 mm", the area of the surface of the 1 st main surface 21 is "0.72 mm²". Therefore, by setting the thickness T1 of the main body BD to "0.15 mm" or more and "0.3 mm" or less, the aspect ratio can be made less than "0.5".

As shown in fig. 1 and 3, the inductance component 10 includes: an insulating 1 st surface layer 31 covering the 1 st main surface 21 of the main body BD and an insulating 2 nd surface layer 32 covering the 2 nd main surface 22. In the present embodiment, the 1 st surface layer 31 covers only the 1 st main surface 21 of the side surfaces of the main body BD. However, the 1 st surface layer 31 does not cover the portion of the 1 st main surface 21 where the vertical wiring 60 is exposed and the periphery of the portion. The 2 nd surface layer 32 covers only the 2 nd main surface 22 of the side surfaces of the main body BD. In other words, the non-principal surface 23, which is a portion of the side surface of the main body BD other than the 1 st principal surface 21 and the 2 nd principal surface 22, is not covered with the insulating layer. In other words, the non-main surface 23 of the magnetic layer 20 is exposed to the outside.

An inductance wiring 40 and an insulating layer 50 in contact with the inductance wiring 40 are provided in the main body BD. The insulating layer 50 is disposed on the opposite side of the 1 st main surface 21 with the inductance wiring 40 interposed therebetween. The insulating layer 50 is located inward of the 2 nd main surface 22 in the thickness direction X1, and the insulating layer 50 is located between the portion of the magnetic layer 20 constituting the 2 nd main surface 22 and the inductance wiring 40.

The insulating layer 50 is a nonmagnetic insulator. The insulating layer 50 has higher insulation than the magnetic layer 20. The insulating layer 50 contains, for example, polyimide resin, acrylic resin, epoxy resin, phenol resin, or liquid crystal polymer. In order to improve the insulating performance of the insulating layer 50, the insulating layer 50 may contain an insulating filler such as a silica filler. In the present embodiment, the nonmagnetic insulator is a structure including a material having a resistivity of "1M Ω · cm" or more and a relative permeability of "1".

The inductance component 10 includes: a plurality of vertical wirings 60 connected to the inductance wiring 40, and a plurality of external terminals 70 provided on the 1 st main surface 21. In the present embodiment, the number of external terminals 70 provided on the 1 st main surface 21 is the same as the number of vertical wirings 60. Each vertical wiring 60 is provided in the main body BD and extends from a connection portion with the inductance wiring 40 toward the 1 st main surface 21. The vertical wiring 60 is connected to only the external terminal 70 corresponding to the vertical wiring 60 among the external terminals 70. That is, of both ends of the vertical wiring 60, the end opposite to the end to which the inductance wiring 40 is connected to the external terminal 70. In addition, the external terminal 70 is exposed outside the inductance wiring 40.

Next, the inductance wiring 40 will be explained.

The inductance wiring 40 is made of a conductive material. The inductance wiring 40 contains at least one of copper, silver, gold, and aluminum as a conductive material, for example. For example, the inductance wire 40 may contain an alloy containing at least two of copper, silver, gold, and aluminum as the conductive material. In the present embodiment, as shown in fig. 4, the inductance wiring 40 includes: a seed layer 401 for wiring, which is a seed layer in contact with the insulating layer 50, and a conductive layer 402 on the opposite side of the insulating layer 50 with the seed layer 401 for wiring interposed therebetween. The seed layer 401 for wiring includes copper as an example of a conductive material. When a portion of the seed layer 401 for wiring having the largest dimension in the thickness direction X1 is defined as a maximum thickness portion and a dimension of the maximum thickness portion in the thickness direction X1 is defined as a thickness of the seed layer 401 for wiring, the thickness of the seed layer 401 for wiring is "30 nm" or more and "500 nm" or less. The conductive layer 402 contains copper and sulfur, for example. In the case where the conductive layer 402 contains copper and sulfur, for example, in the conductive layer 402, the ratio of copper is preferably "99 wt%" or more and the ratio of sulfur is preferably "0.1 wt%" or more and less than "1.0 wt%". The inductance wiring 40 may not include the seed layer 401 for wiring.

As shown in fig. 3, when the dimension of the inductor wiring 40 in the thickness direction X1 is set to be the thickness T2 of the inductor wiring 40, the thickness T2 of the inductor wiring 40 is "40 μm" or more and "55 μm" or less.

The seed layer 401 for wiring may have a structure including at least one of a layer containing titanium and a layer containing tungsten as a layer. By forming the seed layer 401 for wiring in a multilayer structure in this manner, the adhesion between the inductor wiring 40 and the insulating layer 50 can be further improved.

As shown in fig. 2 and 3, the inductance wiring 40 is provided along a predetermined plane 100 in the main body BD. The predetermined plane 100 is a virtual plane formed by a portion of the insulating layer 50 in surface contact with the inductance wiring 40. In the present embodiment, the predetermined plane 100 is a plane parallel to the 1 st main surface 21, but a virtual plane not parallel to the 1 st main surface 21 may be the predetermined plane 100. Fig. 3 is a cross-sectional view of the inductance component 10 cut in a direction perpendicular to a line LN1 indicated by a one-dot chain line in fig. 2.

The inductor wiring 40 includes a1 st land 41, a2 nd land 42, and a wiring body 43 connecting the 1 st land 41 and the 2 nd land 42. Each of the pads 41 and 42 is a connection portion of the inductance wiring 40 to the vertical wiring 60.

Fig. 4 is a partially enlarged view of fig. 3. In fig. 4, a cross section of the 1 st pad 41 in the inductance wiring 40 in a direction orthogonal to an extending direction of the inductance wiring 40 from the 1 st pad 41 is illustrated. Here, a direction orthogonal to the thickness direction X1 among the directions along the cross section is taken as a width direction X2. The width direction X2 is also a direction along the prescribed plane 100.

As shown in fig. 2, the wiring main body 43 is formed in a spiral shape around the central axis 20z of the main body BD on a predetermined plane 100. Specifically, in a plan view, the wiring main body 43 is spirally wound from the radially outer end 43b toward the radially inner end 43a in a counterclockwise direction in the drawing.

Here, the number of turns of the inductance wiring is determined based on the imaginary vector. The starting point of the virtual vector is arranged on a virtual central line which passes through the center of the wiring width of the inductance wiring and extends in the extending direction of the inductance wiring. When viewed from the thickness direction X1, the imaginary vector is in contact with an imaginary center line extending in the extending direction of the inductor wiring. When the starting point is moved to the other end of the virtual center line from a state where the starting point of the virtual vector is arranged at one end of the virtual center line, the number of turns is defined as "1.0 turn" when the angle of rotation of the virtual vector in the direction of rotation is "360 °. Therefore, for example, when the orientation of the virtual vector is rotated by "180 °", the number of turns becomes "0.5 turns".

In the present embodiment, the orientation of the virtual vector virtually arranged on the wiring main body 43 of the inductance wiring 40 is rotated by "540 °. Therefore, in the present embodiment, the number of turns of the wiring main body 43 wound becomes "1.5 turns".

The 2 nd land 42 is connected to an outer peripheral end portion 43b of the wiring main body 43. The 1 st dummy wiring 44 extending along the predetermined plane 100 toward the outer edge of the main body BD is connected to the 2 nd pad 42. The 1 st dummy wiring 44 is exposed at the non-main surface 23 of the inductance component 10. The 1 st land 41 is disposed on the predetermined plane 100, similarly to the wiring main body 43 and the 2 nd land 42. The 1 st pad 41 is connected to an inner peripheral end 43a of the wiring main body 43.

A2 nd dummy wiring 45 extending along the predetermined plane 100 toward the outer edge of the main body BD is connected to a portion between the outer peripheral end 43b and the inner peripheral end 43a of the wiring main body 43, where the portion is wound by "0.5 turns" from the outer peripheral end 43 b. The 2 nd dummy wiring 45 is exposed at the non-main surface 23 of the inductance component 10.

Incidentally, in the present embodiment, the inductance wiring line provided in the main body BD is only the inductance wiring line 40 located above the predetermined plane 100. In other words, no inductor wiring is provided on an imaginary plane between the upper surface of the inductor wiring 40 and the 1 st main surface 21 and an imaginary plane between the plane 100 and the 2 nd main surface 22 of fig. 3, respectively. In other words, the inductance wiring provided in the main body BD is only the inductance wiring 40 disposed on the predetermined plane 100. Therefore, in the inductance component 10 of the present embodiment, it can be said that the number of layers of the inductance wiring is only 1.

Next, the external terminal 70 will be explained.

As shown in fig. 3 and 4, the external terminal 70 is in contact with both the main body BD and the 1 st surface layer 31. That is, the 1 st surface layer 31 is provided with a through hole 312 that exposes the 1 st main surface 21 of the main body BD to the outside. The external terminal 70 is formed by filling the through hole 312. Therefore, the external terminal 70 is in contact with all of the 1 st main surface 21, the peripheral wall of the through hole 312, and the surface 311 of the 1 st surface layer 31.

The external terminal 70 is a laminate in which a plurality of layers are laminated. In the example shown in fig. 3 and 4, the external terminal 70 is a laminate in which three layers 71, 72, 73 are laminated. Of the layers 71 to 73, the layer 71 located closest to the inductance wiring 40 in the thickness direction X1 is in contact with both the 1 st main surface 21 and the peripheral wall of the through hole 312.

The laminate includes, for example, the following layers.

(A) A layer comprising a displacement catalyst.

(B) A layer produced by electroless plating.

As a method for forming the layer containing the substitution catalyst, for example, a method of bringing a portion (magnetic powder) exposed from the through hole 312 in the magnetic layer 20 into contact with a treatment liquid containing the substitution catalyst formed on the electroless copper plating layer formed on the vertical wiring 60 can be cited. Thus, the surface portion of the electroless copper plating is replaced with a replacement type catalyst such as palladium to form a layer containing the catalyst. Thereafter, a layer containing the substitution catalyst is immersed in a plating solution such as electroless nickel plating, thereby forming an electroless nickel plating layer on the layer containing the substitution catalyst.

In addition, as a method not using a substitution type catalyst, a basic catalyst process method can be cited. In this case, a catalyst (for example, lead ions) is also deposited on the 1 st surface layer 31, and a layer containing the catalyst is also formed on the 1 st surface layer 31. Therefore, a layer is also formed on the 1 st surface layer 31 by electroless plating. Therefore, it is necessary to remove unnecessary layers on the 1 st skin layer 31.

The layer generated by electroless plating is, for example, a conductive layer in which the ratio of copper is "99 wt%" or less and the ratio of nickel is "0.1 wt%" or more. The ratio referred to herein is a ratio with respect to the weight of the entire layer formed by electroless plating. For example, the ratio can be calculated based on the content of each element with respect to the entire layer generated by electroless plating. Specifically, by performing ICP analysis on this layer, the ratio can be calculated. "ICP" is a shorthand for "Inductively Coupled Plasma".

Next, the 1 st skin layer 31 and the 2 nd skin layer 32 will be explained.

As shown in fig. 4, the thickness Tl1 of the 1 st skin layer 31 and the thickness Tl2 of the 2 nd skin layer 32 are thinner than the thickness T1 of the main body BD. For example, the thickness Tl1 of the first surface layer 31 is not less than "3 μm" and not more than "10 μm". Also, for example, the thickness Tl2 of the 2 nd skin layer 32 is thinner than the thickness Tl1 of the 1 st skin layer 31.

The surface roughness of the 1 st surface layer 31 is, for example, "2 μm" or less. The surface roughness of the 2 nd surface layer 32 is, for example, "2 μm" or less. The "surface roughness" referred to herein is an arithmetic mean deviation "Ra". For example, the arithmetic mean deviation can be derived by measuring the surfaces of the surface layers 31 and 32 using a laser microscope with the angle of view as a predetermined angle. The predetermined angle is preferably, for example, an angle "5 times" or more the average particle diameter of the magnetic powder contained in the magnetic layer 20.

The 1 st skin layer 31 and the 2 nd skin layer 32 are each made of resin. Examples of the resin constituting each of the surface layers 31 and 32 include polyimide resin, epoxy resin, phenol resin, and liquid crystal polymer. The 1 st surface layer 31 and the 2 nd surface layer 32 may be formed of a material in which at least two of polyimide resin, epoxy resin, phenol resin, and liquid crystal polymer are mixed. In addition, the 1 st skin layer 31 and the 2 nd skin layer 32 may contain an inorganic filler in order to reduce the thermal expansion coefficient of the 1 st skin layer 31 and the 2 nd skin layer 32. Examples of the inorganic filler to be contained in the 1 st surface layer 31 and the 2 nd surface layer 32 include silica, barium sulfate, titanium oxide, and alumina powder. In addition, the 1 st surface layer 31 and the 2 nd surface layer 32 do not contain magnetic powder, respectively.

The 1 st skin layer 31 and the 2 nd skin layer 32 each contain a colorant. The 1 st skin layer 31 and the 2 nd skin layer 32 may contain a pigment, a dye, a pigment, or the like as a colorant. As the color tone of the colorant, for example, a color index is given. Examples of the colorant contained in the 1 st surface layer 31 and the 2 nd surface layer 32 include phthalocyanine pigments, colored barium sulfate, titanium oxide, and carbon black. Since the 1 st surface layer 31 and the 2 nd surface layer 32 are insulating layers, the colorant contained therein is preferably insulating.

In the present embodiment, the 1 st skin layer 31 is different in color from the 2 nd skin layer 32. For example, when the color of the 2 nd surface layer 32 is black, the color of the 1 st surface layer 31 may be white. Even when the color tones of the surface layers 31 and 32 are of the same color system, the color tone of the 1 st surface layer 31 and the color tone of the 2 nd surface layer 32 are different from each other in density, whereby the color tone of the 1 st surface layer 31 and the color tone of the 2 nd surface layer 32 are different from each other. The "color" as used herein is determined by chroma, and brightness, which are three attributes of color. Further, "the color of the 1 st skin layer 31 is different from the color of the 2 nd skin layer 32" means that at least one of the following (C), (D), and (E) is satisfied.

(C) The chroma of the 1 st skin layer 31 is different from the chroma of the 2 nd skin layer 32.

(D) The 1 st skin 31 has a different chromaticity from the 2 nd skin 32.

(E) The brightness of the 1 st skin 31 is different from that of the 2 nd skin 32.

For example, the 2 nd surface layer 32 preferably has higher barrier properties than the 1 st surface layer 31. By making the content of the colorant per unit volume of the 2 nd surface layer 32 larger than the content of the colorant per unit volume of the 1 st surface layer 31, the barrier property of the 2 nd surface layer 32 can be made higher than that of the 1 st surface layer 31. In addition, by making the 2 nd surface layer 32 different in color from the 1 st surface layer 31, the 2 nd surface layer 32 can be made to have higher blocking properties than the 1 st surface layer 31.

An example of a method of evaluating the level of the shielding property will be described. That is, the colored base layer is observed by visual observation or a solid microscope under white light through the layer to be evaluated, and the colored base layer is not observed by visual observation or a solid microscope under white light through the layer to be evaluated. Then, the degree of discoloration of the underlayer was obtained in the case where the underlayer was confirmed directly and in the case where the underlayer was confirmed through the layer to be evaluated. Then, the degree of discoloration of the underlayer at this time was evaluated as the level of the light-shielding property of the layer. In the case of the present embodiment, the degree of discoloration when the foundation layer was confirmed through the 1 st skin layer 31, which is one of the evaluation objects, was taken as the 1 st degree of discoloration. The degree of discoloration when the foundation layer was confirmed through the 2 nd skin layer 32, which is one of the evaluation targets, was defined as the 2 nd degree of discoloration. In this case, the 2 nd color change degree is larger than the 1 st color change degree, and the 2 nd surface layer 32 has higher barrier property than the 1 st surface layer 31.

In addition, in the 1 st skin layer 31, the ratio of the colorant is preferably "1 wt%" or more and "5 wt%" or less. The denominator in this case is the sum of the total weight of the 1 st skin layer 31, i.e., the content of the resin, the content of the filler, and the content of the colorant of the 1 st skin layer 31. If the ratio of the colorant is less than "1 wt%", the color of the 1 st surface layer 31 may be too light. On the other hand, if the ratio of the colorant is "5 wt%" or more, the light transmittance may deteriorate. Consider the case where photolithography is implemented when the inductive component 10 is manufactured. In this case, if the light transmittance of the 1 st surface layer 31 is deteriorated, the patterning accuracy is deteriorated, and there is a possibility that the yield of the inductance component 10 is lowered. Therefore, in order to suppress deterioration of the light transmittance to an allowable range, the 1 st surface layer 31 having a colorant ratio of "5 wt%" or less is preferably provided on the 1 st main surface 21.

For example, the ratio of the coloring agent can be derived by composition analysis of the 1 st surface layer 31 by ICP. For example, the ratio of the colorant can be confirmed by imaging 3 or more portions of the 1 st surface layer 31 with an FE-SEM (field emission scanning electron microscope) at a magnification of "5000 times" or more, and performing EDX analysis. In this case, the total content is defined after removing the deposition coating material and noise components used in the pretreatment for observation of FE-SEM. Examples of the vapor deposition coating material and the noise component include platinum. Further, "EDX" is a shorthand for "Energy discrete X-ray spectroscopy".

In the inductance component 10 shown in fig. 1, no terminal is provided on the 2 nd surface layer 32 side. Therefore, even when photolithography is performed during the manufacture of the inductance component 10, the light transmittance of the 2 nd surface layer 32 is low, and the reduction in the patterning accuracy can be eliminated. Therefore, the ratio of the colorant of the 2 nd skin layer 32 may be higher than the ratio of the colorant of the 1 st skin layer 31.

For example, the 2 nd surface layer 32 may contain a black colorant in order to improve the barrier property of the 2 nd surface layer 32. Examples of the black coloring agent include carbon black, ketjen black, perylene black, titanium oxide, iron oxide, cobalt oxide, anthraquinone, and other black pigments. Further, the 2 nd surface layer 32 may be colored black by including a plurality of colorants having different colors in the 2 nd surface layer 32. The resistivity of the 2 nd surface layer 32 is preferably set to "10M Ω · cm" or more.

Next, the operation and effect of the present embodiment will be described.

(1) In some cases, at least one of the 1 st surface layer 31 covering the 1 st main surface 21 and the 2 nd surface layer 32 covering the 2 nd main surface 22 may be polished at the time of manufacturing the inductance component 10 or at the time of mounting the inductance component 10. In this case, polishing marks may remain on the surface. In addition, when the inductance component 10 is manufactured or when the inductance component 10 is stored, the irregular shape damage may occur on the surfaces 311 and 321 of the 1 st surface layer 31 and the 2 nd surface layer 32.

In the present embodiment, the 1 st surface layer 31 covering the 1 st main surface 21 and the 2 nd surface layer 32 covering the 2 nd main surface 22 each contain a colorant. Therefore, even if the surface is scratched, the scratch is not noticeable as compared with the case where the 1 st skin layer 31 and the 2 nd skin layer 32 do not contain a colorant. This damage is unlikely to affect the accuracy of the appearance inspection performed during the manufacture and mounting of the inductance component 10.

Here, when the damage formed on the surface is conspicuous, the following may occur by the appearance inspection.

In the appearance inspection, an inspection related to the shape and size of the external terminal exposed to the surface layer may be performed. Such an inspection is performed using an inspection apparatus. Therefore, if such damage is present in the vicinity of the external terminal, there is a possibility that the shape and size of the external terminal cannot be accurately measured by the inspection apparatus. In this way, the shape and size of the external terminal cannot be accurately measured regardless of whether the shape and size of the external terminal are actually appropriate, and therefore, it is possible to determine that the inductance component is defective.

In the visual inspection, the surface of the surface layer may be inspected for unevenness. Such inspection is also performed using an inspection apparatus. When the surface of the surface layer is damaged as described above, the damage is also regarded as a single dent in the inspection apparatus, and it may be determined that the degree of surface unevenness is large. In this case, the degree of unevenness obtained by the inspection device may exceed the allowable range regardless of whether the actual degree of unevenness falls within the allowable range, and the inductance component may be determined to be defective.

In this regard, in the present embodiment, since the damage to the surface layer is not conspicuous, the damage is not easily detected by the inspection device in the above-described visual inspection. Therefore, the reduction in the inspection accuracy of the appearance inspection can be suppressed.

(2) The 1 st skin layer 31 is made of a different color than the 2 nd skin layer 32. Thus, when the surface 311 of the 1 st skin layer 31 is the 1 st surface 311 and the surface 321 of the 2 nd skin layer 32 is the 2 nd surface 321, the 1 st surface 311 provided with the external terminals 70 and the 2 nd surface 321 not provided with the external terminals 70 can be easily distinguished. In addition, identifiers for identifying the 1 st surface 311 and the 2 nd surface 321 may not be provided on the 1 st surface 311 and the 2 nd surface 321.

(3) The dimensions of the inductive component 10 also typically include a surface layer covering the sides of the main body BD. Therefore, the larger the surface covered with the surface layer in the side surface of the main body BD, the higher the proportion of the volume of the surface layer in the volume of the inductance component 10. That is, the volume of the main body BD needs to be made small. The small volume of the main body BD means that the proportion of the magnetic layer 20 in the inductance component 10 is low. In addition, the lower the proportion of the magnetic layer 20 in the inductance component 10, the greater the inductance of the inductance component 10 can be made.

Therefore, by configuring the 1 st surface layer 31 to cover only the 1 st main surface 21 of the side surfaces of the main body BD, the volume of the main body BD can be increased as compared with the case where the non-main surface 23 of the side surfaces of the main body BD, which is continuous with the 1 st main surface 21, is also covered by the 1 st surface layer 31. As a result, the ratio of the magnetic layer 20 in the inductance component 10 can be suppressed from decreasing, and the inductance of the inductance component 10 can be increased.

In addition, by configuring the 2 nd surface layer 32 to cover only the 2 nd main surface 22 of the side surfaces of the main body BD, the volume of the main body BD can be increased as compared with the case where the non-main surface 23 of the side surfaces of the main body BD, which is connected to the 2 nd main surface 22, is also covered by the 2 nd surface layer 32. As a result, the ratio of the magnetic layer 20 in the inductance component 10 can be suppressed from decreasing, and the inductance of the inductance component 10 can be increased.

(4) When the 1 st surface layer 31 contains the inorganic filler, the thermal expansion coefficient of the 1 st surface layer 31 can be reduced, and the occurrence of bending of the inductance component 10 including the 1 st surface layer 31 can be suppressed. In addition, the insulation of the 1 st surface layer 31 can be improved.

In addition, when the 2 nd surface layer 32 contains an inorganic filler, the thermal expansion coefficient of the 2 nd surface layer 32 can be reduced, and the occurrence of bending of the inductance component 10 including the 2 nd surface layer 32 can be suppressed. In addition, the insulation of the 2 nd surface layer 32 can be improved.

(5) When the thickness T1 of the main body BD is thicker than "0.3 mm", the inductance component 10 may be increased in size, and the degree of freedom in mounting the inductance component 10 may be lowered. In this regard, in the present embodiment, the thickness T1 is "0.3 mm" or less. Therefore, the inductance component 10 can ensure sufficient strength and suppress a reduction in the degree of freedom of mounting the inductance component 10.

When the thickness T1 of the main body BD is small, the irregularities on the side surfaces of the main body BD are likely to be conspicuous if the particle diameter of the magnetic powder contained in the magnetic layer 20 is large. That is, when the thickness T1 of the main body BD is "0.3 mm" or less, if the average particle size of the magnetic powder contained in the magnetic layer 20 is larger than "5 μm", the ratio of the particle size of the magnetic powder to the thickness T1 of the main body BD becomes high, and the unevenness of the side surface of the main body BD is easily conspicuous. Therefore, the average particle diameter of the magnetic powder contained in the magnetic layer 20 is preferably set to "1 μm" or more and "5 μm" or less. This can suppress the increase in the ratio, and further, the unevenness of the side surface of the main body BD is not easily conspicuous.

Further, by including an iron-based magnetic powder as the magnetic powder in the magnetic layer 20, the dc bias characteristics of the inductance component 10 can be improved.

In the case of a thin inductance component having a thickness T1 of "0.3 mm" or less, the thicknesses of the respective layers to be laminated are not uniform, and therefore the sum of the thicknesses of the irregularities of the thicknesses of the inductance component is relatively large with respect to the thickness of the inductance component. Therefore, in order to suppress such unevenness to a constant range, it is necessary to provide a step of polishing the surface of at least one of the 1 st surface layer 31 and the 2 nd surface layer 32 as a step of adjusting the thickness of the inductance component 10 after the layers are laminated.

(6) When the main body BD contains magnetic powder, unevenness is likely to occur on the 1 st main surface 21. Therefore, if the thickness Tl1 of the 1 st surface layer 31 is less than "3 μm", the 1 st surface layer 31 becomes too thin, and unevenness is likely to occur on the surface 311 of the 1 st surface layer 31. That is, the flatness of the surface 311 of the 1 st skin layer 31 tends to be low. Therefore, by setting the thickness Tl1 of the 1 st surface layer 31 to "3 μm" or more, the flatness of the surface 311 of the 1 st surface layer 31 can be improved, and the degree of unevenness of the surface 311 can be reduced.

When the thickness Tl1 of the 1 st surface layer 31 is made thicker than "10 μm", the ratio of the layer containing no magnetic powder in the inductance component 10 becomes high, and the inductance of the inductance component 10 is not easily increased. Therefore, by setting the thickness Tl1 of the 1 st surface layer 31 to "10 μm" or less, the proportion of the layer containing no magnetic powder in the inductance component 10 can be suppressed from increasing. As a result, the inductance of the inductance component 10 can be increased.

(7) Since no external terminal is provided on the 2 nd skin layer 32 side, the 2 nd skin layer 32 may be made thinner than the 1 st skin layer 31. By making the 2 nd surface layer 32 thin in this manner, the proportion of the layer containing no magnetic powder in the inductance component 10 can be suppressed from increasing. As a result, the inductance of the inductance component 10 can be increased.

(8) By making the 2 nd surface layer 32 have higher barrier properties than the 1 st surface layer 31, damage to the surface 321 of the 2 nd surface layer 32 can be made less conspicuous even if the 2 nd surface layer 32 is thinner than the 1 st surface layer 31.

(9) By containing the black colorant in the 2 nd surface layer 32, the barrier property of the 2 nd surface layer 32 can be improved.

(10) By setting the surface roughness of the 1 st surface layer 31 to "2 μm" or less, the amount of light reflected at the surface 311 of the 1 st surface layer 31 can be stabilized. As a result, the reduction in the inspection accuracy can be suppressed in the above-described appearance inspection.

In addition, by setting the surface roughness of the 2 nd surface layer 32 to "2 μm" or less, the amount of light reflected at the surface 321 of the 2 nd surface layer 32 can be stabilized. As a result, the reduction in the inspection accuracy can be suppressed in the above-described appearance inspection.

Next, an example of the method for manufacturing the inductance component 10 will be described with reference to fig. 5 to 18. The manufacturing method of the present embodiment is a method using a semi-additive method for forming the inductance wiring 40.

As shown in fig. 5, in the initial step S11, a base insulating layer 210 is formed on a substrate 200. As shown in fig. 6, the substrate 200 has a plate shape. The material of the substrate 200 may be, for example, ceramic. In fig. 6, the upper surface of the substrate 200 is referred to as a front surface 201, and the lower surface of the substrate 200 is referred to as a rear surface 202. Further, the base insulating layer 210 is formed on the substrate 200 as a whole covering the surface 201 of the substrate 200. The base insulating layer 210 is made of the same nonmagnetic material as the insulating layer 50 constituting the inductance component 10. The base insulating layer 210 can be formed, for example, by applying a polyimide varnish containing trifluoromethyl and silsesquioxane to the surface 201 of the substrate 200 by spin coating.

If the formation of the base insulating layer 210 is finished, the process proceeds to the next step S12. In step S12, as shown in fig. 6, the insulating layer 211 for patterning is formed on the base insulating layer 210. At least the upper portion of the pattern insulating layer 211 in fig. 6 constitutes the insulating layer 50 of the inductance component 10. For example, the insulating layer 211 for patterning can be formed by patterning a nonmagnetic insulating resin on the insulating base layer 210 by a photolithography technique. In this case, the insulating layer 211 for pattern is formed using a polyimide varnish of the same type as the material used for forming the insulating base layer 210.

When the formation of the insulating layer 211 for pattern is completed, the process proceeds to the next step S13. In step S13, a seed layer 220 is formed. That is, as shown in fig. 7, the seed layer 220 is formed so as to cover the entire upper surface of the insulating layer 212 at the time of manufacturing, which is composed of the base insulating layer 210 and the insulating layer 211 for pattern. The seed layer 220 containing copper is formed, for example, by sputtering. For example, in step S13, the seed layer 220 is formed to a thickness of about "200 nm". A part of the seed layer 220 located on the pattern insulating layer 211 serves as a wiring seed layer 401 constituting the inductance wiring 40.

If the formation of the seed layer 220 is finished, the process proceeds to the next step S14. In step S14, the seed layer 220 is entirely coated with photoresist. For example, a photoresist is coated on the seed layer 220 by spin coating. Next, exposure using an exposure device is performed. Thus, a portion of the photoresist corresponding to a position where the conductive layer 402 is formed can be removed by a developing process described later, and the other portion is cured. In addition, when a negative resist is used as the photoresist, the exposed portion of the photoresist is cured, and the other portions can be removed. On the other hand, when a positive resist is used as the photoresist, the exposed portion of the photoresist can be removed, and the remaining portion can be cured. By controlling the exposed portion of the photoresist, a portion attached to the insulating layer 212 at the time of manufacturing can be partially cured. Next, by a development treatment using a developer, as shown in fig. 7, a portion of the photoresist corresponding to a position where the conductive layer 402 is formed is removed. In addition, the cured portion of the photoresist remains on the seed layer 220 as the 1 st protective film 230A. By patterning the 1 st protective film 230A on the seed layer 220 in this manner, the wiring pattern PT is formed. The wiring pattern PT has an opening shape corresponding to the shape of the inductance wiring 40 of the inductance component 10.

When the formation of the wiring pattern PT is completed, the process proceeds to the next step S15. In step S15, a conductive material is supplied into the wiring pattern PT, whereby the conductive layer 402 as shown in fig. 8 is formed. For example, by performing electrolytic copper plating using an aqueous copper sulfate solution, copper and a slight amount of sulfur mainly precipitate on the exposed portion of the seed layer 220. Thereby, the conductive layer 402 is formed. Since a copper sulfate aqueous solution is used, the conductive layer 402 contains sulfur. The inductance wiring 40 is formed by the conductive layer 402 and a portion of the seed layer 220 which is in contact with the conductive layer 402. That is, a portion of the seed layer 220 which is in contact with the conductive layer 402 serves as the seed layer 401 for wiring.

When the formation of the conductive layer 402 is completed, the process proceeds to the next step S16. In step S16, the 1 st protective film 230A is removed by a process using a stripping liquid, as shown in fig. 9. When the removal of the 1 st protective film 230A is completed, a portion of the seed layer 220 in contact with the 1 st protective film 230A is removed. For example, a portion of the seed layer 220 in contact with the 1 st protective film 230A is removed by wet etching. Thus, only the portion of the seed layer 220 to be the seed layer 401 for wiring remains.

When the removal processing in step S16 ends, the process proceeds to the next step S17. In step S17, a photoresist is applied to hide the inductance wiring 40. The photoresist is applied, for example, by spin coating. Next, exposure using an exposure device is performed. Thus, the photoresist can be removed at a portion corresponding to the position where the vertical wiring 60 is formed by a developing process described later, and the other portion is cured. Next, as shown in fig. 10, the photoresist is subjected to a developing treatment using a developer to remove a portion of the photoresist which adheres to the insulating layer 211 for a pattern. In addition, a cured portion of the photoresist remains on the insulating layer 212 as the 2 nd protective film 230B at the time of manufacturing. By patterning the 2 nd protective film 230B on the insulating layer 212 at the time of manufacturing in this manner, the vertical pattern PT1, which is a pattern for forming the vertical wiring 60, is formed.

If the formation of the vertical pattern PT1 ends, the process proceeds to the next step S18. In step S18, as shown in fig. 11, the vertical wiring 60 is formed. For example, by performing electrolytic copper plating using a copper sulfate aqueous solution, the vertical wiring 60 can be formed in the vertical pattern PT 1. In this case, the inductor wiring 40 is supplied with power through the dummy wirings 44 and 45, and copper as a conductive material is supplied into the vertical pattern PT 1. In the case where the copper sulfate aqueous solution is used in this manner, the vertical wiring 60 contains a slight amount of sulfur.

When the formation of the vertical wiring 60 is completed, the process proceeds to the next step S19. In step S19, the 2 nd protective film 230B is removed as shown in fig. 12 by a process using a stripping liquid.

When the removal processing in step S19 ends, the process proceeds to the next step S20. In step S20, the 1 st magnetic sheet 25A illustrated in fig. 13 is pressed from above in the figure. Thereby, the inductance wiring 40 and the vertical wiring 60 are embedded in the 1 st magnetic sheet 25A. The 1 st magnetic sheet 25A pressed from the upper side in the drawing in step S20 may be a single-layer sheet or a laminate in which a plurality of layers are laminated. Next, as shown in fig. 14, the upper side of the 1 st magnetic sheet 25A in the figure is ground until the end portion of the two ends of the vertical wiring 60 on the side not in contact with the inductance wiring 40 is visible from the upper side in the figure.

When the pressing of the 1 st magnetic sheet 25A and the grinding of the 1 st magnetic sheet 25A are finished, the process proceeds to the next step S21. In step S21, as shown in fig. 14, the 1 st surface layer 31 is formed on the upper surface of the 1 st magnetic sheet 25A in the figure. In the present embodiment, the 1 st skin layer 31 containing a colorant is formed. For example, the 1 st surface layer 31 can be formed by coating a non-magnetic insulating resin on the 1 st magnetic sheet 25A. In this state, the vertical wiring 60 is also covered with the 1 st surface layer 31. Therefore, through holes 312 are formed in the 1 st surface layer 31 at positions where the external terminals 70 are formed. For example, the through-holes 312 can be formed by irradiating the 1 st surface layer 31 with laser light. In addition, when the 1 st surface layer 31 is formed, the 1 st surface layer 31 may be formed by patterning a non-magnetic insulating resin on the 1 st magnetic sheet 25A by a photolithography technique. In this case, since the 1 st surface layer 31 having the through-hole 312 can be formed by the photolithography technique, the step of forming the through-hole 312 using a laser can be omitted.

When the formation of the 1 st skin layer 31 is completed, the process proceeds to the next step S22. In step S22, the substrate 200 and the base insulating layer 210 are removed by grinding as shown in fig. 15. At this time, a part of the insulating layer 211 for pattern may be removed. By this process, the remaining insulating layer 211 for pattern becomes the insulating layer 50 of the inductance component 10.

When the grinding is finished, the process proceeds to the next step S23. In step S23, the 2 nd magnetic sheet 25B illustrated in fig. 16 is pressed from below in the figure. Thereby, the inductance wiring 40 is sandwiched between the 1 st magnetic sheet 25A and the 2 nd magnetic sheet 25B. The 2 nd magnetic sheet 25B pressed from below in the drawing in step S23 may be a single-layer sheet or a laminate in which a plurality of layers are laminated. The lower side of the 2 nd magnetic sheet 25B in the drawing is ground, whereby the main body BD of the inductance component 10 is configured.

When the pressing of the 2 nd magnetic sheet 25B and the grinding of the 2 nd magnetic sheet 25B are finished, the process proceeds to the next step S24. In step S24, as shown in fig. 17, the 2 nd surface layer 32 is formed on the lower surface of the 2 nd magnetic sheet 25B in the drawing. For example, the 2 nd surface layer 32 can be formed by coating a non-magnetic insulating resin on the 2 nd magnetic sheet 25B. In the case where the through-holes are provided in the 2 nd skin layer 32, the through-holes may be formed by laser after the application of the insulating resin. In addition, the 2 nd surface layer 32 having the through-holes can also be formed by patterning the non-magnetic insulating resin on the 2 nd magnetic sheet 25B by the photolithography technique.

When the formation of the 2 nd skin layer 32 is completed, the process proceeds to the next step S25. In step S25, as shown in fig. 18, the external terminal 70 is formed. Thereby, a series of processes constituting the manufacturing method of the inductance component 10 is ended.

The above-described manufacturing method is an example of a case where the inductance component 10 is manufactured one by one. However, the method of manufacturing the inductance component 10 is not limited thereto. For example, the portions to be the plurality of inductance components 10 may be arranged in a matrix on the substrate 200, and may be singulated by dicing or the like at step S25 or less. After the application of the nonmagnetic insulating resin and after the pressing of the magnetic sheet, a curing step such as heating may be performed as necessary.

In addition, according to the manufacturing method as described above, the following effects can be obtained.

(11) By containing the colorant in the 1 st surface layer 31 and the 2 nd surface layer 32, the inductance component 10 which is less likely to be damaged by the 1 st surface layer 31 and the 2 nd surface layer 32 can be manufactured. This can suppress a reduction in inspection accuracy in the appearance inspection. Therefore, the yield of the inductance component 10 can be stabilized.

The above embodiment can be modified and implemented as follows. The above-described embodiment and the following modifications can be implemented in combination with each other within a range not technically contradictory.

The inductance component may be provided with a plurality of inductance wirings in the main body BD. Fig. 19 and 20 illustrate the inductance component 10A in which two inductance wirings 40A, 40B that are not in contact with each other are provided in the main body BD. Fig. 20 is a view showing a cross section in a case where the inductance component 10A shown in fig. 19 is cut in a direction orthogonal to a line LN2 shown by a one-dot chain line. The 1 st end of the 1 st inductor line 40A of the inductor lines 40A and 40B is connected to the vertical line 60A1, and the 2 nd end of the 1 st inductor line 40A is connected to the vertical line 60A 2. In addition, the vertical wiring 60B1 is connected to the 1 st end of the 2 nd inductor wiring 40B, and the vertical wiring 60B2 is connected to the 2 nd end of the 2 nd inductor wiring 40B. The vertical wirings 60A1, 60A2, 60B1, and 60B2 extend from the connection portions with the inductance wirings 40A and 40B to the first main surface 1 21 of the main body BD. The inductance component 10A includes the same number of external terminals 70 as the number of vertical wirings extending to the 1 st main surface 21. The vertical wirings 60a1, 60a2, 60B1, and 60B2 are connected to only the external terminals 70 individually corresponding to the external terminals 70.

The 1 st main surface 21 of the inductance component 10A is covered with the 1 st surface layer 31A. The 2 nd main surface 22 of the inductance component 10A is covered with the 2 nd surface layer 32A. The 1 st surface layer 31A contains a colorant in the same manner as the 1 st surface layer 31 of the inductance component 10 described in the above embodiment. In addition, the 2 nd surface layer 32A contains a colorant, similarly to the 2 nd surface layer 32 of the inductance component 10 described in the above embodiment.

The inductance wiring may have a shape different from the shapes described in the above embodiment and the modifications. The inductance wiring is not particularly limited in structure, shape, material, and the like as long as it can provide inductance to the inductance component by generating magnetic flux all around when current flows. The inductance wiring may have various known wiring shapes such as a spiral shape having not less than "1 turn", a curved shape having less than "1.0 turn", and a meandering shape.

For example, as shown in fig. 21, the inductance component 10 may be configured such that a part of the side surface of the main body BD other than the main surface 23 connected to the 1 st main surface 21 is also covered with the 1 st surface layer 31.

For example, as shown in fig. 21, the inductance component 10 may be configured such that a part of the side surface of the main body BD other than the main surface 23 connected to the 2 nd main surface 22 is also covered with the 2 nd surface layer 32.

In the above embodiment, the vertical wiring 60 of the inductance component 10 extends in the thickness direction X1. However, in the inductance component 10, the extending direction of the vertical wiring 60 may be different from the thickness direction X1.

The laminate constituting the external terminal 70 preferably contains at least one metal selected from copper, nickel, gold, and tin, for example. Further, for example, the laminate may contain an alloy composed of at least two of copper, nickel, gold, and tin.

For example, the outermost layer among the layers constituting the external terminal 70 may be a mother solder layer for improving solder wettability. The mother solder layer preferably contains gold, tin, or the like. In addition, the mother solder layer may include at least one alloy of an alloy containing gold and an alloy containing tin. The outermost layer may be a layer that suppresses oxidation of the external terminal 70.

Further, for example, a layer positioned in the middle among the plurality of layers may be the corrosion-inhibiting layer. The corrosion-inhibiting layer preferably contains nickel, for example. In addition, the corrosion-inhibiting layer may also include an alloy including nickel.

The external terminal may not be a laminate in which a plurality of layers are laminated.

The external terminal may not contact the 1 st main surface 21 of the main body BD as long as it is connected to the vertical wiring 60.

The inductance component may not include an external terminal. In this case, of both ends of the vertical wiring, an end portion on the opposite side to the end portion connected to the inductance wiring is exposed to the outside.

It is not always necessary to make the surface roughness of the 1 st surface layer 31 "2 μm" or less.

It is not always necessary to make the surface roughness of the 2 nd surface layer 32 "2 μm" or less.

The 2 nd surface layer 32 may not contain a black colorant as long as the 2 nd surface layer 32 can have higher shielding property than the 1 st surface layer 31.

The content of the colorant per unit volume of the 2 nd surface layer 32 may not be more than the content of the colorant per unit volume of the 1 st surface layer 31 as long as the barrier property of the 2 nd surface layer 32 can be made higher than the barrier property of the 1 st surface layer 31.

The shielding property of the 2 nd surface layer 32 may not be higher than that of the 1 st surface layer 31.

The 2 nd skin layer 32 may not be thinner than the 1 st skin layer 31. For example, when the inductance component is configured to include the vertical wiring extending from the connection portion to the inductance wiring to the 2 nd main surface 22, the thickness Tl2 of the 2 nd surface layer 32 is preferably set to be approximately the same as the thickness Tl1 of the 1 st surface layer 31, or the thickness Tl2 of the 2 nd surface layer 32 is preferably set to be thicker than the thickness Tl1 of the 1 st surface layer 31.

The thickness Tl1 of the 1 st surface layer 31 may be less than "3 μm" as long as the degree of unevenness of the surface 311 of the 1 st surface layer 31 can be within an allowable range.

The thickness Tl1 of the 1 st surface layer 31 may be made thicker than "10 μm" as long as the inductance of the inductance component 10 can be sufficiently ensured.

The average particle size of the magnetic powder contained in the magnetic layer 20 may be larger than "5 μm" as long as the degree of unevenness of the side surface of the main body BD having the magnetic layer 20 can be suppressed to an allowable range.

The thickness T1 of the main body BD of the inductance component 10 may be made thicker than "0.3 mm".

The 1 st surface layer 31 may contain no inorganic filler.

The 2 nd surface layer 32 may not contain an inorganic filler.

The color of the 1 st skin layer 31 may be the same as the color of the 2 nd skin layer 32.

The inductance component may be configured differently from the inductance component 10 as long as it includes an inductance wiring, a vertical wiring connected to the inductance wiring, a1 st surface layer, and a2 nd surface layer. For example, the inductance component may include: a main body in which a1 st magnetic layer, an insulating layer, and a2 nd magnetic layer are laminated in this order in a thickness direction X1. In this case, the inductance wiring is sandwiched between either the 1 st magnetic layer and the insulating layer or the 2 nd magnetic layer and the insulating layer. The 1 st magnetic layer itself may be a laminate in which a plurality of layers are laminated. Similarly, the 2 nd magnetic layer itself may be a laminate in which a plurality of layers are laminated. In the inductance component having such a configuration, the 1 st main surface of the body is formed by the 1 st magnetic layer, and the 2 nd main surface of the body is formed by the 2 nd magnetic layer.

The inductance component may be a structure in which the inductance wiring is covered with an insulating layer.

The inductance component may have a structure without the insulating layer 50.

The inductance component may be configured such that the 1 st main surface 21 is covered with the 1 st surface layer 31 and the 2 nd main surface 22 is covered with the 2 nd surface layer 32, and the non-main surface 23 of the main body BD may be covered with another surface layer. The surface layer covering the non-principal surface 23 may contain a colorant or may not contain a colorant as long as it is an insulating layer. In the method for manufacturing the inductance component, it is preferable to provide the step of forming the surface layer covering the non-main surface 23 separately from the step of providing the 1 st surface layer 31 on the 1 st main surface 21 and the step of providing the 2 nd surface layer 32 on the 2 nd main surface 22.

The inductance component may be manufactured by another manufacturing method without using the semi-additive method. For example, the inductance component may be manufactured using a sheet lamination process, a printing lamination process, or the like. The inductor wiring may be formed by a thin film method such as sputtering or vapor deposition, a thick film method such as printing or coating, or a plating process such as full-additive plating or subtractive plating.