TW201330027A - Magnetic element and manufacturing method thereof - Google Patents

Abstract

The present invention aims to provide a magnetic element and a manufacturing method thereof capable of reducing contact resistance in contrast to the prior art. The magnetic element comprises: an insulating substrate (11); a first coil (12); a second coil (13); a conducting layer (14) for connecting winding start ends to each other via a through hole; a first extraction electrode layer (15) electrically connected to a winding terminal of the first coil; and a second extraction electrode layer (16) electrically connected to a winding terminal of the second coil. The first coil, the second coil, the conducting layer, the first extraction electrode layer, and the second extraction electrode layer are formed integrally. Each extraction electrode layer (15,16) comprises: a side surface portion (15a,16a) formed on the side surface of the insulating substrate; an upper surface portion (15b,16b); and a lower surface portion (15c,16c).

Description

Magnetic element and method of manufacturing same

The present invention relates to a magnetic element including a coil and an extraction electrode layer drawn from the coil on the surface of the insulating base material, and a method of manufacturing the same.

An invention relating to a thin film magnetic element used as a planar inductor or the like is disclosed in the following patent documents.

Patent Document 1 or Patent Document 2 discloses a laminated structure in which coils are formed on the upper and lower surfaces of an insulating base material. However, Patent Document 1 or Patent Document 2 does not disclose the structure of the extraction electrode layer electrically connected to the coil.

On the other hand, in Patent Document 3, Patent Document 4, and Patent Document 5, a structure in which an electrode layer is taken out is disclosed. However, since it is formed separately from the coil, there is a problem that contact resistance increases. Further, in the structure in which the coils are provided on the upper and lower sides of the insulating base material, contact resistance is also generated between the respective coils and the conduction layers which are formed in the through holes formed in the insulating base material and which are electrically connected to the respective coils.

In addition, conventionally, the step of forming the coil is separated from the step of forming the extraction electrode layer, and the manufacturing efficiency is lowered.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 4-363006

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2000-243637

[Patent Document 3] Japanese Patent Laid-Open No. Hei 8-115840

[Patent Document 4] Japanese Patent Laid-Open No. Hei 9-270342

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2000-68125

Accordingly, an object of the present invention is to solve the above-described conventional problems, and in particular to provide a magnetic element capable of reducing contact resistance as compared with the related art and a method of manufacturing the same.

Further, an object of the present invention is to provide a method of manufacturing a magnetic element capable of improving the manufacturing efficiency of a coil and an extraction electrode layer.

A magnetic element according to the present invention includes: an insulating base material; and a first coil formed on an upper surface of the insulating base material; and a second coil formed on a lower surface of the insulating base material; and a conductive layer formed through the conductive layer The through hole of the insulating substrate is electrically connected between a winding start end located inside the first coil and a winding start end located inside the second coil; and the first extraction electrode layer is located at the foregoing a winding terminal on the outer side of the coil is electrically connected; and a second extraction electrode layer is electrically connected to the winding end located outside the second coil, the first coil, the second coil, the conduction layer, and the foregoing The first extraction electrode layer and the second extraction electrode layer are integrally formed, and the first extraction electrode layer has a first side surface portion formed on the first side surface of the insulating substrate, and a first upper surface portion from the first side surface unit Extending from the upper surface of the insulating base material and integrally connected to the winding end of the first coil; and the first lower surface portion extending from the first side surface portion toward the lower surface of the insulating base material, the first portion The second extraction electrode layer has a second side surface portion formed on a second side surface of the insulating base material different from the first side surface, and a second lower surface portion extending from the second side surface portion toward a lower surface of the insulating base material And connected integrally with the winding end of the second coil. Thereby, the contact resistance between the first coil and the first extraction electrode layer, between the second coil and the second extraction electrode layer, and between the respective coils and the conduction layer can be reduced as compared with the related art. Further, high inductance can be obtained by using a coil on the upper and lower sides of the insulating substrate.

In addition, each of the extraction electrode layers includes not only the upper surface portion and the lower surface portion but also a side surface portion, and is integrated with the upper surface portion and the lower surface portion to support the insulating base material from both sides, so that each of the extraction electrode layers can be used as a deformation preventing magnetic element. The support on both sides functions.

In the invention, it is preferable that the first upper surface portion and the first lower surface portion constituting the first extraction electrode layer and the second lower surface portion constituting the second extraction electrode layer are formed to be larger than the first a coil and the second coil are thick, a first magnetic layer is disposed on a front surface side of the first coil, and a second magnetic layer is disposed on a lower surface side of the second coil, the first magnetic layer and the first upper surface Each surface of the portion is formed substantially on the same surface, or the surface of the first upper surface portion protrudes away from the surface of the first magnetic layer in a direction away from the insulating substrate, and the second magnetic layer, the first lower portion, and the The surface of the second lower portion is large The surfaces formed on the same surface or the first lower portion and the second lower portion protrude from the surface of the second magnetic layer in a direction away from the insulating substrate. In the present invention, each surface of the lower surface portion and the upper surface portion is formed to be substantially flush with or protruded from each surface of the magnetic layer, whereby the first extraction electrode layer and the first extraction electrode layer can be attached to the circuit board by solder or the like. The second extraction electrode layer is appropriately connected to the circuit board, and the occurrence of defects can be prevented. Further, by using the magnetic layer, the Q value can be improved, and the magnetic layer can be used as the magnetic shield.

Further, in the invention, it is preferable that the first upper surface portion and the first lower surface portion constituting the first extraction electrode layer and the second lower surface portion constituting the second extraction electrode layer have the An inner layer having substantially the same thickness as the coil and the second coil, and an outer layer formed by overlapping the inner layer, wherein the inner layer and the outer layer are integrated. Thereby, the electrode layer can be integrally formed by the simple structure, and the contact resistance can be effectively reduced.

Further, in the invention, it is preferable that the inner layer and each of the coils are composed of a foil formed on a surface of the insulating base material and a first plating layer formed by being combined with the foil, wherein the outer layer is Forming a second plating layer formed by overlapping a plating layer, wherein the first side surface portion of the first extraction electrode layer and the second side surface portion of the second extraction electrode layer are respectively formed by the first plating layer and the second surface A laminated structure of the plating layer is formed. Thereby, the thickness of the first coil and the second coil can be increased, and the coil resistance can be reduced.

Further, in the invention, it is preferable that the first plating layer is an electroless plating layer, and the second plating layer is an electrolytic plating layer. Thus The first plating layer based on electroless plating can be appropriately formed on the first side surface and the second side surface of the edge substrate, and the first extraction electrode can be formed by using a laminated structure of the first plating layer and the second plating layer a first side surface portion of the layer and a second side surface portion of the second extraction electrode layer. Further, by forming a laminated structure of the first plating layer based on electroless plating and the second plating layer by electrolytic plating, the thickness of the plating layer can be made thick.

Further, in the invention, it is preferable that the first coil and the first upper surface portion of the first extraction electrode layer have a first foil formed on an upper surface of the insulating substrate, the second coil, and the The first lower surface portion of the first extraction electrode layer and the second lower surface portion of the second extraction electrode layer have a second foil formed on a lower surface of the insulating substrate, on the surface of the first foil and the aforementioned The surfaces of the second foil are superposed to form a plating layer, and the first extraction electrode layer has a surface from the first foil through the first side surface of the insulating substrate to the surface of the second foil. The formed plating layer constitutes the first upper surface portion, the first side surface portion, and the first lower surface portion, and the second extraction electrode layer has the first side surface from the insulating substrate until the second portion A plating layer formed on the surface of the foil body constitutes the second side surface portion and the second lower surface portion. Thereby, the thickness of the first coil and the second coil can be increased, the coil resistance can be reduced, and the first extraction electrode layer and the second extraction electrode layer can be easily and appropriately formed, the first extraction electrode layer and the second extraction electrode. Layer has a first foil The surface and the surface of the second foil are formed on the first side and the second side of the insulating substrate.

Further, in the invention, it is preferable that the first extraction electrode layer is formed to have substantially the same length as the first side surface, and the second extraction electrode layer is formed to have substantially the same length as the second side surface. The first extraction electrode layer and the second extraction electrode layer can be formed in a large area, and the contact resistance with the connection terminal of the mounting substrate can be reduced, and the electrical property between each of the extraction electrode layers and the connection terminal can be reliably and simply connection.

Further, in the invention, it is preferable that a pad is formed on an outermost surface of the first extraction electrode layer and the second extraction electrode layer. Thereby, the magnetic element can be appropriately welded to the mounting substrate.

Further, in the invention, it is preferable that the second extraction electrode layer has the second side surface portion and the second upper surface portion extending from the second side surface portion toward the upper surface of the insulating base material, and The same structure as the first upper surface portion; and the second lower portion. Thereby, since the upper surface portion and the lower surface portion are respectively provided on the first extraction electrode layer and the second extraction electrode layer, the mounting substrate can be reliably and simply mounted on either of the upper and lower surfaces of the magnetic element. The connection is made to improve the assemblability.

Further, in the invention, it is preferable that a direction in which the first coil is extended from a first end of the winding start end is a first direction, and a direction in which the second coil is extended from a first end of the winding start end a second direction opposite to the first direction, wherein the second side surface of the insulating substrate is located on a side opposite to the first side surface, the first direction and the front side The second direction is an orthogonal direction orthogonal to the longitudinal direction of the first side surface and the second side surface of the insulating base material. The number of turns of the first coil and the second coil can be made the same, and the number of turns can be increased to the maximum, and the inductance can be increased.

Further, the method for producing a magnetic element according to the present invention includes the first step of preparing a first foil body on the upper surface of the insulating base material and forming the second foil body on the lower surface thereof to be cut into a plurality of insulating members of the magnetic element, wherein a through hole is formed at a position between the regions of the insulating substrate that is a magnetic element, and a through hole is formed in a region where each magnetic element is formed; and a second step, wherein the first foil And the second foil is formed to form a first plating layer by weight, and a conductive layer based on the first plating layer is formed in the through hole, and from the surface of the first foil to the through hole Forming the first plating layer on the side wall surface and the surface of the second foil body; and the third step of forming the first foil body and the first surface on the upper surface side of the insulating base material by using a lithography technique a first coil formed by plating a layer, and a second coil having the second foil body and the first plating layer formed on a lower surface side of the insulating base material, and at this time, the first coil is located The inner winding end and the inner winding end of the second coil are integrally formed with the conduction layer, and a first extraction electrode layer is formed to form a second extraction electrode layer, and the first extraction electrode layer has a first side surface portion. Formed in the foregoing a first side surface of the edge substrate corresponding to the first side wall surface of the through hole; and a first upper surface portion extending from the first side surface portion toward the upper surface of the insulating substrate and located outside the first coil The winding end is integrated; and the first lower portion extends from the first side portion toward the lower surface of the insulating substrate; the second extraction electrode layer has a second side portion formed on the insulating substrate a second side wall surface different from the through hole corresponding to the second side surface of the first side surface; and a second lower surface portion extending from the second side surface portion toward the lower surface of the insulating base material and located at the foregoing The winding terminal on the outer side of the two coils is integrated; in the fourth step, the insulating substrate is cut to obtain a plurality of the magnetic elements.

In the present invention, each of the coil, the conduction layer, and the extraction electrode layer can be formed in the same step, and each of the coil, the conduction layer, and each of the extraction electrode layers can be integrally formed. Therefore, in the present invention, a thin inductor capable of reducing the contact resistance between the coil and the extraction electrode layer and between the coil and the conduction layer can be manufactured with higher manufacturing efficiency than conventionally.

In the present invention, it is preferable that a surface of the first plating layer and the second extraction electrode layer overlap each other on the surface of the first plating electrode layer and the second extraction electrode layer between the third step and the fourth step In the fifth step of the second plating layer, after the fifth step, the sixth step of disposing the first magnetic layer on the upper surface side of the first coil and the second magnetic layer on the lower surface side of the second coil is superposed. And the first magnetic layer and the surface of the first upper surface are substantially the same surface or the first surface The surface of the portion of the first magnetic layer protrudes away from the insulating substrate, and the surfaces of the second magnetic layer, the first lower surface, and the second lower surface are substantially the same or Each surface of the first lower surface portion and the second lower surface portion protrudes in a direction away from the insulating base material than a surface of the second magnetic material layer. According to the above, the second plating layer can be formed on the first plating layer of the first extraction electrode layer and the second extraction electrode layer, and the first upper surface portion and the first lower surface of the first extraction electrode layer can be formed. The second lower portion of the face and the second extraction electrode layer is formed thicker than each of the coils. Therefore, when the magnetic layer is superposed on the surface side of the coil, each surface of each of the magnetic layer, the first extraction electrode layer, and the second extraction electrode layer can be formed on substantially the same surface, or each of the lower surface and the upper surface portion can be formed. The structure in which the surface protrudes from each surface of each magnetic layer.

Further, in the invention, it is preferable that a pad is formed on the outermost surface of the first extraction electrode layer and the second extraction electrode layer.

Further, in the invention, it is preferable that a second upper surface portion is formed on the second extraction electrode layer together with the second side surface portion and the second lower surface portion, the second upper surface portion being from the second side surface The portion extends to the upper surface of the insulating base material and has the same structure as the first upper surface portion.

According to the magnetic element of the present invention, the contact resistance between the first coil and the first extraction electrode layer, between the second coil and the second extraction electrode layer, and between the respective coils and the conduction layer can be reduced as compared with the related art.

In addition, the method of manufacturing the magnetic element according to the present invention can be Each of the coil, the conduction layer, and each of the extraction electrode layers is formed in the same step, and each of the coil, the conduction layer, and each of the extraction electrode layers can be integrally formed. Thereby, the manufacturing efficiency can be improved.

1(a) is a plan view of a thin inductor of the present embodiment, in particular, a top view of an upper surface of a first coil and an extraction electrode layer provided on an insulating substrate, and a broken line indicating a portion disposed under an insulating substrate FIG. 1(b) is a longitudinal cross-sectional view of the thin inductor of the present embodiment taken along line AA of FIG. 1(a) and viewed from the direction of the arrow, and FIG. 1(c) is set in insulation. FIG. 2 is a partially enlarged longitudinal cross-sectional view of the thin inductor shown in FIG. 1(b), showing a plan view of a lower portion of the second coil and the lower electrode layer of the substrate.

As shown in FIG. 1(b), the thin inductor (magnetic element) 10 has an insulating base material 11, a first coil 12, a second coil 13, a conduction layer 14, a first extraction electrode layer 15, and a second extraction electrode layer 16. Magnetic sheets (magnetic layers) 17, 30.

The material of the insulating base material 11 is not particularly limited, but is preferably a glass epoxy substrate corresponding to a copper foil (foil) of each of the coils 12 and 13 to be described later.

In Fig. 1(a), the plane of the insulating substrate 11 is a square or rectangular shape, but the shape is not limited.

As shown in FIGS. 1(a) and (b), the first coil 12 is formed on the upper surface 11a of the insulating base material 11. Further, as shown in FIG. 1(b), the second coil 13 is formed on the lower surface 11b of the insulating base material 11.

As shown in Fig. 1(a), the first coil 12 is a planar coil which is bent at a right angle from the winding start end 12a of the inner side to the outer winding end 12b and simultaneously wound. As shown in Fig. 1(a), the first coil 12 extends from the first extension of the winding start end 12a in the direction α1 in the X1 direction.

Further, as shown in FIG. 1(c), the second coil 13 is a planar coil which is bent at a right angle from the winding start end 13a on the inner side to the winding end 13b on the outer side. As shown in Fig. 1(c), the second coil 13 extends from the first direction of the winding start end 13a and the direction α2 is the X2 direction.

As shown in FIG. 1(b), a through hole 11c penetrating from the upper surface 11a to the lower surface 11b is formed substantially at the center of the insulating base material 11. As shown in FIG. 1(b), a conduction layer 14 is provided in the through hole 11c. Further, the conduction layer 14 is electrically connected to the winding start end 12a of the first coil 12, and the conduction layer 14 is electrically connected to the winding start end 13a of the second coil 13.

As shown in FIG. 1(b), a first extraction electrode layer 15 is formed on the first side surface (X1 side surface) 11d side of the insulating base material 11. Further, as shown in FIG. 1(b), a second extraction electrode layer 16 is formed on the second side surface (X2 side surface) 11e side of the insulating base material 11.

As shown in FIG. 1(b), the first extraction electrode layer 15 has a first side surface portion 15a formed on the first side surface 11d of the insulating base material 11 and an upper surface 11a of the insulating base material 11 from the first side surface portion 15a. The first upper surface portion 15b extending from the winding end 12b of the first coil 12 and the first lower surface portion 15c extending from the first side surface portion 15a toward the lower surface 11b of the insulating base material 11 are formed.

As shown in FIG. 1(a), the first upper face of the first extraction electrode layer 15 15b is exposed on the upper surface 11a of the insulating base material 11. Further, as shown in FIG. 1(c), the first lower surface portion 15c of the first extraction electrode layer 15 is exposed on the lower surface 11b of the insulating base material 11.

As shown in FIG. 1(b), the second extraction electrode layer 16 has a second side surface portion 16a formed on the second side surface 11e of the insulating base material 11 and an upper surface 11a of the insulating substrate 11 from the second side surface portion 16a. The second upper surface portion 16b that extends is a second lower surface portion 16c that extends from the second side surface portion 16a toward the lower surface 11b of the insulating base material 11 and is connected to the winding end 13b of the second coil 13. In addition, in FIG. 1(a), as will be described later, since the number of turns of the first coil 12 and the second coil 13 coincides, the second side surface 11e is located on the opposite side to the first side surface 11d. However, when the thin inductor 10 is mounted on the mounting substrate 25, it may be formed at a position adjacent to the first side surface 11d depending on the position of the wiring pattern of the connection terminal 25a of the mounting substrate 25.

As shown in FIG. 1(a), the second upper surface portion 16b of the second extraction electrode layer 16 is exposed on the upper surface 11a of the insulating base material 11. Further, as shown in FIG. 1(c), the second lower surface portion 16c of the second extraction electrode layer 16 is exposed on the lower surface 11b of the insulating base material 11.

As shown in FIG. 1(b) and FIG. 2, the first coil 12 is formed on the surface of the first foil body 18 by overlapping with a first foil body (for example, a copper foil) 18 formed on the upper surface 11a of the insulating base material 11. The laminated structure of the first plating layer 19 on 18a is formed.

Further, as shown in FIG. 1(b) and FIG. 2, the second coil 13 is formed of a second foil (for example, a copper foil) formed on the lower surface 11b of the insulating base material 11. 20 is formed by superposing a laminated structure of the first plating layer 19 formed on the face 20a of the second copper foil 20.

As shown in FIG. 1(b) and FIG. 2, the first upper surface portion 15b of the first extraction electrode layer 15 has a laminated structure of the first foil body 18 and the first plating layer 19, similarly to the first coil 12. In the first upper surface portion 15b, the laminated structure of the first foil body 18 and the first plating layer 19 is regarded as the inner layer 21. Further, as shown in FIGS. 1(b) and 2, the first lower surface portion 15c of the first extraction electrode layer 15 has a laminated structure of the second foil body 20 and the first plating layer 19 in the same manner as the second coil 13. In the first lower portion 15c, the laminated structure of the second foil 20 and the first plating layer 19 is regarded as the inner layer 22.

As shown in FIG. 2, the inner layer 21 of the first upper surface portion 15b of the first extraction electrode layer 15 is substantially the same film thickness as the first coil 12, and the inner layer 22 of the first lower surface portion 15c of the first extraction electrode layer 15 is The second coil 13 has substantially the same film thickness.

As shown in FIGS. 1(b) and 2, a second plating layer 23 as an outer layer is formed on the surface of the inner layer 21 constituting the first upper surface portion 15b of the first extraction electrode layer 15. Further, a second plating layer 23 as an outer layer is formed on the surface of the inner layer 22 constituting the first lower surface portion 15c of the first extraction electrode layer 15.

Further, as shown in FIGS. 1(b) and 2, the first side surface portion 15a of the first extraction electrode layer 15 is formed by a laminated structure of the first plating layer 19 and the second plating layer 23.

In the first side surface portion 15a of the first extraction electrode layer 15, the first plating layer 19 is directly formed on the first side surface 11d of the insulating substrate 11, in the foregoing The surface of the first plating layer 19 is superposed to form a second plating layer 23.

Although the laminated structure of the first extraction electrode layer 15 has been described above, the same applies to the second extraction electrode layer 16. That is, as shown in FIG. 1(b), the second side surface portion 16a of the second extraction electrode layer 16 is a laminated structure of the first plating layer 19 and the second plating layer 23, and the second upper surface portion 16b is the first foil body. 18. The laminated structure of the first plating layer 19 and the second plating layer 23, and the second lower surface portion 16c is a laminated structure of the second foil body 20, the first plating layer 19, and the second plating layer 23.

As shown in FIG. 1(b), the conduction layer 14 is formed of the first plating layer 19.

For example, the first foils 18, 20 are copper foils, and the first plating layer 19 and the second plating layer 23 are copper plated. Thereby, the inner layers 21 and 22 are integrated with the second plating layer 23 as the outer layer.

As shown in FIGS. 1(a), (b) and 2, the first coil 12 and the first extraction electrode layer 15 are provided with a laminated structure including a common first foil 18 and a first plating layer 19, and are integrated. Further, the second coil 13 and the second extraction electrode layer 16 are provided with a laminated structure including the common second foil 20 and the first plating layer 19, and are integrated. Further, the conduction layer 14 is formed of the first plating layer 19, and is formed integrally with the first coil 12 and the second coil 13 including the first plating layer 19.

As described above, in the present embodiment, the first coil 12, the second coil 13, the first extraction electrode layer 15, the second extraction electrode layer 16, and the conduction layer 14 are integrally formed.

Thereby, the contact resistance can be reduced as compared with the conventional structure in which each of the coils 12 and 13 and each of the extraction electrode layers 15 and 16 are formed. According to this In the configuration of the embodiment, the contact resistance between each coil and each of the extraction electrode layers can be made zero. Further, in the present embodiment, the contact resistance between the coils 12 and 13 and the conduction layer 14 can be reduced, and specifically, the contact resistance between each coil and the conduction layer can be made zero.

In the present embodiment, the first coil 12 and the second coil 13 are formed above and below the insulating base material 11. Thereby, high inductance can be obtained. Further, by forming the coils 12 and 13 on the upper and lower sides of the insulating base material 11, the electrode layers 15 and 16 can be taken out from the respective coils 12 and 13 by a simple structure.

Further, in the present embodiment, the upper surface portions 15b and 16b and the lower surface portions 15c and 16c are provided in both of the first extraction electrode layer 15 and the second extraction electrode layer 16. Therefore, regardless of which of the upper and lower surfaces of the thin inductor 10 faces the mounting substrate 25, it can be electrically connected to the mounting substrate 25. That is, as shown in FIG. 2, the first lower surface portion 15c of the first extraction electrode layer 15 and the second lower surface portion 16c of the second extraction electrode layer 16 not shown in FIG. 2 and the connection terminal 25a on the surface of the mounting substrate 25 are electrically The thin inductor shown in FIG. 2 can also be electrically connected to the connection terminal 25a of the mounting substrate 25 by being reversed by 180 degrees. Thereby, the thin inductor 10 can be easily and reliably attached to the surface of the mounting substrate 25, and good assemblability can be obtained. In addition, if the second coil 13 is connected to the second extraction electrode 16 and the second lower surface portion 16c without such a function, it is considered that the solder layer 35 to be described later is provided on the first and second side surface portions 15a, In the case of the relationship between 16a and the first and second lower portions 15c, the second upper surface portion 16b may not be provided.

In addition, as shown in FIG. 1(b) and FIG. 2, each of the electrode layers 15 is taken out, 16 includes not only the upper surface portions 15b and 16b and the lower surface portions 15c and 16c but also the side surface portions 15a and 16a and integrated with the upper surface portions 15b and 16b and the lower surface portions 15c and 16c, and the insulating base is supported from both sides in the X1-X2 direction. The structure of the material 11. Thereby, each of the extraction electrode layers 15 and 16 can function as a both-side support body that suppresses deformation or the like of the thin inductor.

As shown in FIG. 1(b) and FIG. 2, the first upper surface portion 15b and the first lower surface portion 15c constituting the first extraction electrode layer 15, and the second upper surface portion 16b and the second lower surface constituting the second extraction electrode layer 16 are formed. The portion 16c is formed thicker than the first coil 12 and the second coil 13.

Therefore, a height difference can be formed between each of the upper surface portions 15b and 16b and each of the lower surface portions 15c and 16c of the first extraction electrode layer 15 and the second extraction electrode layer 16 and between the first coil 12 and the second coil 13. Further, as shown in FIGS. 1(b) and 2, the first magnetic sheet 17 is placed on the upper surface of the first coil 12 through the insulating layer (adhesive layer) 31. Further, as shown in FIGS. 1(b) and 2, the second magnetic sheet 30 is placed on the lower surface of the second coil 13 through the insulating layer (adhesive layer) 32. At this time, in the present embodiment, as shown in FIG. 1(b) and FIG. 2, the surfaces of the first magnetic sheet 17, the first upper surface portion 15b, and the second upper surface portion 16b can be arranged substantially flush with each other. The first magnetic sheet 17. Further, the second magnetic sheet 30 can be disposed such that the respective surfaces of the second magnetic sheet 30, the first lower surface portion 15c, and the second lower surface portion 16c are substantially flush with each other.

Alternatively, in the present embodiment, each surface of the first upper surface portion 15b and the second upper surface portion 16b may be formed to protrude from the surface of the first magnetic layer 17 in a direction (upward) away from the insulating base material 11. and Further, each surface of the first lower surface portion 15c and the second lower surface portion 16c may be formed to protrude from the surface of the second magnetic layer 30 in a direction (downward) away from the insulating base material 11.

As described above, each of the upper surface portion, each of the lower surface portions, and each of the magnetic layer layers is formed by substantially the same surface, or each surface of each of the upper surface portion and each of the lower surface portions protrudes outward from each surface of each of the magnetic layer layers, thereby utilizing When the thin inductor 10 is mounted on the mounting substrate 25 such as solder, mounting failure or the like is less likely to occur.

In the present embodiment, by using the magnetic sheets 17, 30, the Q value can be improved, and the magnetic sheets 17, 30 can be used as the magnetic shield. The structure of the magnetic sheets 17, 30 is not particularly limited. A structure in which a magnetic layer of FeAlN or FeN is formed on the surface of an insulating sheet such as polyethylene naphthalate, polyethylene terephthalate or polyamidamide, or FeAlN or on the surface of the insulating sheet The magnetic layer of FeN and the insulating layer of SiO ₂ or the like are alternately laminated with a predetermined number of structures, or a known ferrite sheet, a ferrite plate, a magnetic alloy thin strip, or the like.

For the insulating layers (adhesive layers) 31 and 32 to which the respective coils 12 and 13 and the magnetic sheets 17 and 30 are joined, for example, an epoxy-based low-temperature curing agent or an acryl-based low-temperature curing agent can be used.

Since the insulating layers 31 and 32 are interposed between the coils 12 and 13 and the magnetic sheets 17 and 30, the magnetic layers of the magnetic sheets 17 and 30 can be joined toward the coils 12 and 13 or the magnetic sheets 17 can be joined. The magnetic layers of 30 are joined to the outside. Further, a configuration may be adopted in which an insulating film (not shown) is formed on the surface of the magnetic layer of each of the magnetic sheets 17 and 30 by SiO ₂ , Al ₂ O ₃ , SiAlON, AlN or the like, and the insulating layers 31 and 32 are formed. The magnetic layer of the magnetic sheets 17 and 30 is pressure-bonded and joined to the coils 12 and 13 side in a state in which the above-mentioned adhesive is filled with an adhesive. With this configuration, the adhesive is crushed by pressure bonding, and the gap between the coils 12, 13 and the magnetic sheets 17, 30 is substantially the thickness of the insulating film having only the surface of the magnetic layer, and the magnetic sheets 17, 30 are held. In the insulated state of the coils 12 and 13, the thickness of the thin inductor can be further reduced, and the inductance value and the Q value can be increased.

Further, in the configuration shown in FIG. 2, the respective surfaces of the first magnetic sheet 17, the first upper surface portion 15b, and the second upper surface portion 16b are formed to be substantially the same surface, and the second magnetic sheet 30 and the first lower surface portion 15c are formed. Since the respective surfaces of the second lower surface portion 16c are formed to be substantially the same surface, the upper surface portions 15b and 16b or the respective lower surface portions 15c and 16c can be formed as a mounting surface to the mounting substrate 25, and a connection terminal with the mounting substrate 25 can be obtained. Good electrical connectivity of 25a.

As shown in FIG. 1(b) and FIG. 2, in the present embodiment, the first upper surface portion 15b and the first lower surface portion 15c of the first extraction electrode layer 15 are composed of inner layers 21, 22 and an outer layer (second plating layer). 23) The laminated structure is formed. Further, the inner layer 21 and the coils 12 and 13 are formed to have substantially the same film thickness. In addition, the second extraction electrode layer 16 has the same structure as the first extraction electrode layer 15, and the first extraction electrode layer 15 will be described below.

As shown in FIG. 2, the inner layer 21 of the first upper surface portion 15b and the first coil 12 are a laminated structure of the same first foil body 18 and the first plating layer 19, whereby the first upper surface portion 15b can be The inner layer 21 and the first coil 12 are in phase Formed with the same film thickness.

Further, as shown in FIG. 2, the inner layer 22 and the second coil 13 of the first lower surface portion 15c are a laminated structure of the same second foil body 20 and the first plating layer 19, whereby the first lower surface portion 15c can be used. The inner layer 21 and the second coil 13 are formed to have the same film thickness. The first plating layer 19 is, for example, an electroless plating layer, whereby the first plating layer 19 can be directly formed from the surface of the first foil body 18 and the second foil body 20 to the first side surface 11d of the insulating substrate 11. .

Further, the surface of the first plating layer 19 constituting the first upper surface portion 15b and the first lower surface portion 15c is superposed to form the second plating layer 23, whereby the first upper surface portion 15b and the first lower surface portion 15c can be formed. The film thickness is formed thicker than the first coil 12 and the second coil 13.

Further, the second plating layer 23 is formed to overlap the first plating layer 19 formed on the first side surface 11d, and the first side surface portion 15a is formed by a laminated structure of the first plating layer 19 and the second plating layer 23.

The second plating layer 23 is preferably an electrolytic plating layer. It may be formed as electroless, but when formed into an electrolytic plating layer, the second plating layer 23 can be formed thickly in a short time.

Further, the first plating layer 19 and the second plating layer 23 are formed of the same or homogeneous material, and are preferably integrated.

In order to provide an example of the film thickness of each layer, the film thickness of each of the foils 18 and 20 is about 35 μm, the film thickness of the first plating layer 19 is about 35 μm, and the film thickness of the second plating layer 23 is about 65 to 75 μm. .

As shown in FIGS. 1(a) and 1(c), in the present embodiment, the first extraction electrode layer 15 is the same length as the first side surface 11d of the insulating base material 11. Degree formation. Further, the second extraction electrode layer 16 is formed to have the same length as the second side surface 11e of the insulating base material 11. As shown in FIG. 1(a), the length dimension of the first extraction electrode layer 15, the first side surface 11d, the second extraction electrode layer 16, and the second side surface 11e in the Y1-Y2 direction is L1.

Further, as shown in FIG. 1(a), the first upper surface portion 15b of the first extraction electrode layer 15 and the second upper surface portion 16b of the second extraction electrode layer 16 maintain the length dimension of L1 while being along the X1-X2 direction. The width dimension of T1 is formed. Further, as shown in FIG. 1(c), the first lower surface portion 15c of the first extraction electrode layer 15 and the second lower surface portion 16c of the second extraction electrode layer 16 maintain the length dimension of L1 while being along the X1-X2 direction. The width dimension of T1 is formed.

The length dimension L1 is about 2 to 5 mm, and the width dimension T1 is about 0.35 mm.

Thereby, the first extraction electrode layer 15 and the second extraction electrode layer 16 can be formed over a large area, and the contact resistance with the connection terminal 25a of the mounting substrate 25 can be reduced, and the respective extraction electrode layers 15, 16 and the connection terminal can be provided. Reliable and simple electrical connection between 25a.

Further, as shown in FIG. 2, in the present embodiment, the pad 34 is formed on the outermost surface of the first extraction electrode layer 15. It should be noted that a pad is also formed on the outermost surface of the second extraction electrode layer 16. The pad 34 is, for example, a Ni/Au layer (Ni is a base side), a Ni/Sn layer, a Ni/solder layer, and a Ni/Ag layer. The film thickness of the pad 34 is formed to be as thin as about 5 μm.

As shown in FIG. 2, the first extraction electrode layer 15 and the connection terminal 25a of the mounting substrate 25 are joined by a solder layer 35. By taking out the electricity at the first The pad 34 is provided on the outermost surface of the pole layer 15, and the solder wettability of the outermost surface of the first extraction electrode layer 15 is improved. As shown in FIG. 2, the solder layer 35 having a rounded shape can be formed, and the first extraction electrode can be improved. Electrical connection between the layer 15 and the connection terminal 25a of the mounting substrate 25. It should be noted that the second extraction electrode layer 16 and the connection terminal 25a of the mounting substrate 25 may be joined by a rounded solder layer.

As shown in Fig. 1(a), the direction α1 of the first coil 12 from the first extension of the winding start end 12a is the X1 direction (first direction), and on the other hand, as shown in Fig. 1(c), The first extension from the winding start end 13a of the two coils 13 is the X2 direction (second direction), and the first coil 12 and the second coil 13 extend in opposite directions.

Further, the extending directions α1 and α2 are orthogonal to the longitudinal direction (Y1-Y2) of the first side surface 11d and the second side surface 11e of the insulating base material 11. Thereby, the number of turns of the first coil 12 and the second coil 13 can be made the same, and the number of turns can be increased to the maximum, and the inductance can be increased.

Fig. 3 (a) is another embodiment different from Fig. 1 (a) and Fig. 1 (c), and the right diagram of Fig. 3 (a) shows a plan view of the first coil 40, and the left diagram of Fig. 3 (a) shows A top view of the second coil 41.

As shown in Fig. 3(a), the direction α3 of the first coil 40 from the first extension of the winding start end 40a is the Y1 direction, and the direction α4 of the second coil 41 from the first extension of the winding start end 41a is Y2 direction.

As shown in the right diagram of FIG. 3(a), the winding end 40b of the first coil 40 is connected to the integrated first extraction electrode layer 42, and the first extraction electrode layer 42 is along the first side of the insulating substrate (not The length direction of the illustration) (X1- X2) is formed.

Further, as shown in the left diagram of FIG. 3(a), the winding end 41b of the second coil 41 is connected to the integrated second extraction electrode layer 43, and the second extraction electrode layer 43 is along the second side of the insulating substrate. The longitudinal direction (X1-X2) of (not shown) is formed.

In other words, the first and second coils 40 and 41 of the first coil 40 and the second coil 41 are opposite to each other in the direction α3 and α4 (Y1 to Y2), and the extending directions α3 and α4 are opposite to each other. The longitudinal direction (X1-X2) of the first side surface and the second side surface of the insulating base material is orthogonal.

As a result, as shown in FIG. 3(a), the number of turns of the first coil 40 and the second coil 41 is the same, and when the first coil 40 and the second coil 41 are overlapped, the positions of the respective turns of the first coil 40 are obtained. The position of each turn of the second coil 41 is identical, and the number of turns can be increased to the maximum.

On the other hand, Fig. 3(b) discloses a coil of a comparative example, and the right diagram of Fig. 3(b) shows a plan view of the first coil 45, and the left diagram of Fig. 3(b) shows a plan view of the second coil 46.

As shown in Fig. 3(b), the direction α5 of the first coil 45 from the first extension of the winding start end 45a is the Y1 direction, and the direction α3 of the second coil 46 from the first extension of the winding start end 46a is Y2 direction.

As shown in the right diagram of FIG. 3(b), the winding end 45b of the first coil 45 is connected to the integrated first extraction electrode layer 47, and the first extraction electrode layer 47 is along the side surface of the insulating substrate (not shown). The length direction (Y1-Y2) is formed.

In addition, as shown in the left diagram of FIG. 3(b), the winding of the second coil 46 The terminal 46b is connected to the integrated second extraction electrode layer 48, and the second extraction electrode layer 48 is formed along the longitudinal direction (Y1-Y2) of the side surface (not shown) of the insulating substrate.

In the comparative example of FIG. 3(b), the first coil 45 and the second coil 46 are in the opposite directions from the first extension of the respective winding start ends 45a and 46a, and the directions α5 and α6 (Y1-Y2) are opposite to each other. The extending directions α5 and α6 are parallel to the longitudinal direction (Y1-Y2) of the side surface of the insulating base material on which the extraction electrode layers 47 and 48 are formed.

As a result, as shown in FIG. 3(b), the number of turns of the first coil 45 and the second coil 46 is different. As shown in FIG. 3(b), when viewed from the winding start end 45a of the first coil 45, the number of turns of the Y2 side region is 3, but it is observed from the winding start end 46a of the second coil 46. Next, the number of turns of the coil in the Y2 side region is 4.

As described above, in the comparative example of FIG. 3(b), the number of turns of the first coil 45 and the second coil 46 does not coincide locally, and the number of turns cannot be increased to the maximum, as compared with the embodiment of FIG. 3(a). The inductance drops.

As a result, as shown in FIG. 3( a ), the first coil 40 and the second coil 41 are opposite to each other from the first extending end 40 a , 41 a , and the directions α3 and α4 (Y1 - Y2) are opposite to each other, and The extending directions α3 and α4 are orthogonal to the longitudinal direction (X1-X2) of the first side surface and the second side surface of the insulating base material, whereby an increase in inductance can be achieved. Further, in order to obtain the same number of turns, a thin inductor in which the electrode layer is taken out to form the minimum size may be included.

It should be noted that part of the common features of the present embodiment is A point where the coil, the conduction layer, and the extraction electrode layer are integrated. Thereby, the relationship between the winding direction of the coil and the direction in which the electrode layer is taken out is not excluded from the structure of FIG. 3(b). However, Fig. 3(a) is more preferable.

4 is a longitudinal cross-sectional view of a thin inductor of another embodiment. In FIG. 4, the same elements as those in FIG. 1(b) are denoted by the same reference numerals.

In FIG. 4, unlike FIG. 1(b), the second plating layer 23 is not formed on the first extraction electrode layer 15 and the second extraction electrode layer 16. Therefore, in FIG. 4, the upper surface portions 15b and 16b and the lower surface portions 15c and 16c of the first extraction electrode layer 15 and the second extraction electrode layer 16 are foils similarly to the first coil 12 and the second coil 13 The laminated structure of the bodies 18 and 20 and the first plating layer 19 is formed to have substantially the same film thickness. Therefore, as shown in FIG. 4, a height difference is generated between the surfaces of the magnetic sheets 17, 30 and the upper surface portions 15b, 16b of the respective extraction electrode layers 15, 16 and the surfaces of the respective lower surface portions 15c, 16c. Thereby, as shown in FIG. 3, a gap β is easily formed between each of the lower surface portions 15c and 16c of each of the extraction electrode layers 15 and 16 and the connection terminal 25a of the mounting substrate 25. The gap β is filled by the solder layer 35, and the extraction electrode layers 15 and 16 and the connection terminal 25a are electrically connected to each other through the solder layer 35.

However, in the case of the configuration of FIG. 3, the lower surface portions 15c and 16c of the respective extraction electrode layers 15 and 16 are not mounted on the mounting substrate 25 but are in a floating state, so that the connection terminal 25a can be reduced. Contact resistance between the two, and in order to obtain a reliable connection with the connection terminal 25a, as shown in FIG. 1(b) and FIG. 2, the first extraction electrode layer 15 and the second extraction electrode layer 16 are subjected to the second plating. In the cladding layer 23, the film thicknesses of the upper surface portions 15b and 16b and the lower surface portions 15c and 16c of the respective extraction electrode layers 15 and 16 are formed. The thickness of each of the coils 12 and 13 is thick, and it is preferable that the surfaces of the respective magnetic sheets 17 and 30 and the upper surface portions 15b and 16b of the respective extraction electrode layers 15 and 16 and the surfaces of the lower surface portions 15c and 16c are formed in substantially the same plane. Alternatively, it is preferable that the surfaces of the upper surface portions 15b and 16b and the respective lower surface portions 15c and 16c protrude from the surfaces of the magnetic sheets 17 and 30 in a direction away from the insulating base material 11.

Next, a method of manufacturing the thin inductor (magnetic element) of the present embodiment will be described. Each of the figures of Figure 5 is a partial longitudinal cross-sectional view of a thin inductor at the manufacturing stage. It should be noted that the same elements as those in FIG. 1 and the like are denoted by the same reference numerals.

In Fig. 5(a), an insulating substrate 51 in which a first foil body 18 is formed on the upper surface 11a of the insulating base material 11 and a second foil body 20 is formed on the lower surface 50b is prepared. The insulating substrate 51 is processed as shown in FIGS. 5(b) to 5(f), and is cut by the step of FIG. 5(f), whereby a plurality of thin patterns as shown in FIG. 1 can be obtained from the insulating substrate 51. Inductor. For example, the insulating substrate 51 is preferably a glass epoxy substrate provided with a copper foil on the upper and lower surfaces. Here, the film thickness of the first foil body 18 and the second foil body 20 is, for example, about 35 μm.

In the step of FIG. 5( b ), the through hole 52 is formed at a position between the respective regions when the insulating substrate 51 is divided into a plurality of thin inductors. A through hole 52 is formed in the insulating substrate 51 from the upper surface 51a to the lower surface 51b. The length dimension of the through hole 52 in the Y1-Y2 direction is L1 shown in Fig. 1 . Further, the width dimension T3 of the through hole 52 in the X1-X2 direction is equal to or larger than the width dimension T5 of the through hole 53, and is preferably minimized so that a plurality of thin inductors can be obtained from the insulating substrate 51. In particular, the width dimension T3 is formed larger than that formed on the side faces 11d, 11e of the respective thin inductors The film thickness T4 (see FIG. 1 (a) (b)) obtained by adding the film thickness of the first plating layer 19 and the second plating layer 23 is twice as large. Specifically, the width dimension T3 is 200 μm or more.

Further, as shown in FIG. 5(b), a through hole 53 penetrating from the upper surface 51a of the insulating substrate 51 to the lower surface 51b is formed at a substantially central position of a region where each thin inductor is formed. The through hole 53 is, for example, cylindrical or prismatic. As shown in FIG. 1(b), the width dimension T3 of the through hole 52 is formed larger than the width dimension T5 of the through hole 53.

The formation of the through hole 52 and the through hole 53 can use a lithography technique. Alternatively, not only the lithography technique, but also machining using a drill or the like can form the hole at low cost.

Next, in the step of FIG. 5(c), the first plating layer 19 is formed by electroless plating in superposition with the first foil body 18 and the second foil body 20. At this time, the conduction layer 14 based on the first plating layer 19 is formed in the through hole 53, and from the surface of the first foil body 18 to the surface of the side wall faces 52a, 52b and the second foil body 20 in the through hole 52. The aforementioned first plating layer 19 is formed. The first plating layer 19 is formed, for example, by electroless plating based on Cu. The film thickness of the first plating layer 19 is, for example, about 35 μm.

Next, in the step of FIG. 5(d), the first coil 12 composed of the first foil body 18 and the first plating layer 19 is formed on the upper surface side of each region of the thin inductor by using a lithography technique. Further, a second coil 13 composed of the second foil body 20 and the first plating layer 19 is formed on the lower surface side of each region of the thin inductor.

For example, the planar shape shown by FIG. 1(a) and FIG. 1(c) The first coil 12 and the second coil 13 are formed.

As shown in FIG. 5(d), the winding start end 12a and the conduction layer 14 located inside the first coil 12 are integrally formed, and the winding start end 13a and the conduction layer 14 located inside the second coil 13 are integrated. Formed.

Further, in the step of FIG. 5(d), the first extraction electrode layer 15 connected to the winding terminal 12b located outside the first coil 12 and the winding terminal 13b located outside the second coil 13 are formed. The second extraction electrode layer 16 (see Fig. 1 (a) (c)).

The first side wall surface 52a of the through hole 52 corresponds to the first side surface 11d of the insulating base material 11 constituting the thin inductor 10. Further, the second side wall surface 52b of the through hole 52 corresponds to the second side surface 11e of the insulating base material 11 constituting the thin inductor 10. Further, the first extraction electrode layer 15 has a first side surface portion 15a having a first plating layer 19 based on electroless plating directly formed on the first side wall surface 52a, and an insulating substrate 11 from the first side surface portion 15a. The first upper surface portion 15b extending from the upper surface thereof and the first lower surface portion 15c extending from the first side surface portion 15a toward the lower surface of the insulating base material 11. Further, the second extraction electrode layer 16 has a second side surface portion 16a having a first plating layer 19 based on electroless plating directly formed on the second side wall surface 52b, and an insulating substrate 11 from the second side surface portion 16a. The second upper surface portion 16b extending from the upper surface thereof and the second lower surface portion 16c extending from the second side surface portion 16a toward the lower surface of the insulating base material 11.

As shown in FIGS. 1(a) and (c), the first extraction electrode layer 15 and the second extraction electrode layer 16 are formed by the length dimension L1 along the Y1-Y2 direction. The length dimension L1 and the first of the insulating substrates 11 constituting each of the thin inductors 10 The lengths of the side surface 11d and the second side surface 11e in the Y1-Y2 direction are the same.

As shown in FIG. 5(d) and FIG. 1(a), the first coil 12 and the first extraction electrode layer 15 are similarly formed by a laminated structure of the first foil 18 and the first plating layer 19, and are first The winding end 12b of the coil 12 is integrally formed up to the first upper surface portion 15b of the first extraction electrode layer 15. Further, as shown in FIGS. 5(d) and 1(c), the second coil 13 and the second extraction electrode layer 16 are similarly formed by a laminated structure of the second foil 20 and the first plating layer 19, and The winding end 13b of the two coils 13 is integrally formed up to the second lower surface portion 16c of the second extraction electrode layer 16.

Next, in the step of FIG. 5(e), the second plating layer 23 is formed on the surface of the first plating layer 19 of the first extraction electrode layer 15 and the second extraction electrode layer 16 by electrolytic plating. . The second plating layer 23 is preferably formed of the same or homogenous material as the first plating layer 19. The second plating layer 23 is formed, for example, by Cu. Further, the film thickness of the second plating layer 23 is, for example, about 65 to 75 μm.

In order to form the second plating layer 23 only on the first extraction electrode layer 15 and the second extraction electrode layer 16, it is only necessary to provide a resist layer in a region other than the first extraction electrode layer 15 and the second extraction electrode layer 16 without plating. The second plating layer 23 may be used.

Thereby, the thicknesses of the upper surface portions 15b and 16b and the lower surface portions 15c and 16c of the first extraction electrode layer 15 and the second extraction electrode layer 16 can be made thicker than the first coil 12 and the second coil 13.

At this time, each of the first extraction electrode layer 15 and the second extraction electrode layer 16 The side surface portions 15a and 16a are formed by a laminated structure of the first plating layer 19 and the second plating layer 23. At this time, as shown in FIG. 5(e), the first extraction electrode layer 15 and the second extraction electrode layer 16 adjacent to each other in the through hole 52 are not in contact with each other, and space is separated.

Further, the first plating layer 19 and the second plating layer 23 are formed of the same or homogeneous material, and the first plating layer 19 and the second plating layer 23 are integrated.

Further, on the outermost surfaces of the first extraction electrode layer 15 and the second extraction electrode layer 16, a Ni/Au layer (Ni is a base side), a Ni/Sn layer, a Ni/solder layer, a Ni/Ag layer, or the like is formed. Pad 34 (see Figure 2).

Next, in the step of FIG. 5(f), insulating layers 31 and 32 are formed on the surfaces of the first coil 12 and the second coil 13. As the insulating layers 31 and 32, an epoxy-based low-temperature curing agent or a propylene-based low-temperature curing agent can be used. Further, magnetic sheets 17, 30 are adhered to the surfaces of the insulating layers 31, 32. At this time, the surfaces of the magnetic sheets 17, 30 and the upper surface portions 15b and 16b of the first extraction electrode layer 15 and the second extraction electrode layer 16 and the surfaces of the lower surface portions 15c and 16c may be formed on substantially the same plane. Further, the surfaces of the upper surface portions 15b and 16b and the lower surface portions 15c and 16c of the first extraction electrode layer 15 and the second extraction electrode layer 16 may be further away from the surface of the magnetic sheets 17, 30 in the direction away from the insulating substrate 11. protruding. As described above, at least the magnetic sheets 17 and 30 are not protruded from the surfaces of the upper surface portions 15b and 16b and the respective lower surface portions 15c and 16c as long as the solder is mounted on the circuit board without any hindrance.

Further, when the insulating substrate 51 is cut from the position of the single-dot chain line of FIG. 5(f), a plurality of thin inductors 10 can be obtained.

Fabrication of the thin inductor 10 according to the present embodiment shown in FIG. As shown in FIGS. 5(b) to 5(d), each of the coils 12, 13, the conduction layer 14, and the respective extraction electrode layers 15, 16 can be formed by the same process, and the coils 12, 13, and the conduction layers are formed. 14 and each of the extraction electrode layers 15, 16 can be integrally formed. As a result, in the present embodiment, it is possible to reduce the manufacturing efficiency of the coils 12 and 13 and the extraction electrode layers 15 and 16 and the coils 12 and 13 and the conduction layer 14 more than conventionally. A thin inductor with a contact resistance between.

Further, in the step of FIG. 5(e), the first plating layer 23 can be superposed on the first plating layer 19 of the first extraction electrode layer 15 and the second extraction electrode layer 16, and the first extraction electrode can be removed. The first upper surface portion 15b and the first lower surface portion 15c of the layer 15 and the second upper surface portion 16b and the second lower surface portion 16c of the second extraction electrode layer 16 are formed thicker than the respective coils 12 and 13. Therefore, in the step of FIG. 5(f), the magnetic sheets 17 which are substantially flush with the surfaces of the first extraction electrode layer 15 and the second extraction electrode layer 16 can be appropriately and easily provided on the surfaces of the coils 12 and 13, 30. Alternatively, the surfaces of the first extraction electrode layer 15 and the second extraction electrode layer 16 may protrude from the surfaces of the magnetic sheets 17, 30.

Further, in order to manufacture the thin inductor having the structure shown in Fig. 4, the step of Fig. 5(e) may be omitted.

Further, in the present embodiment, the second upper surface portion 16b constituting the second extraction electrode layer 16 may not be formed. By providing a resist or the like at the position of the second upper surface portion 16b without forming a plating layer, it is possible to form a thin inductor having no structure of the second upper surface portion 16b.

10‧‧‧Small inductors

11‧‧‧Insulation substrate

11c, 53‧‧‧through holes

12, 40, 45‧‧‧ first coil

12a, 13a, 40a, 41a, 45a, 46a‧‧‧ winding start

12b, 13b, 40b, 41b, 45b, 46b‧‧‧ winding terminal

13, 41, 46‧‧‧ second coil

14‧‧‧ conduction layer

15, 42, 47‧‧‧ first extraction electrode layer

15a‧‧‧First side section

15b‧‧‧First upper face

15c‧‧‧ first lower part

16, 43, 48‧‧‧ second extraction electrode layer

16a‧‧‧Second side section

16b‧‧‧Second upper face

16c‧‧‧ second lower part

17, 30‧‧‧ magnetic sheets

18‧‧‧First foil

19‧‧‧First plating layer

23‧‧‧Second plating

25‧‧‧Installation substrate

31, 32‧‧‧Insulation

34‧‧‧ solder pads

35‧‧‧ solder layer

51‧‧‧Insert substrate

52‧‧‧through holes

1] FIG. 1(a) is a plan view of a thin inductor of the present embodiment, in particular, a top view of an upper surface of a first coil and an extraction electrode layer provided on an insulating substrate, and is indicated by a broken line. FIG. 1(b) is a longitudinal cross-sectional view of the thin inductor of the embodiment, taken along the line AA shown in FIG. 1(a) and viewed from the direction of the arrow. Fig. 1 (c) is a plan view of a lower portion of the second coil and the extraction electrode layer provided under the insulating substrate.

FIG. 2 is a partially enlarged longitudinal cross-sectional view of the thin inductor shown in FIG. 1(b).

3] FIG. 3(a) and FIG. 3(b) are plan views of the first coil and the second coil.

4] Fig. 4 is a longitudinal cross-sectional view of a thin inductor according to another embodiment.

5(a) to 5(f) are process drawings (longitudinal cross-sectional views) for explaining a method of manufacturing the thin inductor of the present embodiment.

10‧‧‧Small inductors

11‧‧‧Insulation substrate

11a‧‧‧Top of insulating substrate

11b‧‧‧Under the insulating substrate

11c‧‧‧through hole

11d‧‧‧First side of the insulating substrate

11e‧‧‧Second side of the insulating substrate

12‧‧‧First coil

12a, 13a‧‧‧ winding start

12b, 13b‧‧‧ winding terminal

13‧‧‧second coil

14‧‧‧ conduction layer

15‧‧‧First take-out electrode layer

15a‧‧‧First side section

15b‧‧‧First upper face

15c‧‧‧ first lower part

16‧‧‧Second take-out electrode layer

16a‧‧‧Second side section

16b‧‧‧Second upper face

16c‧‧‧ second lower part

17‧‧‧ Magnetic sheet

18‧‧‧First foil

19‧‧‧First plating layer

20‧‧‧Second foil

23‧‧‧Second plating

30‧‧‧Second magnetic sheet

31, 32‧‧‧Insulation

L1‧‧‧ length dimensions

T1‧‧‧Width size

T4‧‧‧ film thickness

Claims (14)

A magnetic element characterized by comprising: an insulating substrate; and a first coil formed on the upper surface of the insulating substrate; and a second coil formed on a lower surface of the insulating substrate; and a conductive layer formed through the foregoing The through hole of the insulating substrate is electrically connected between the winding start end of the inner side of the first coil and the winding start end of the inner side of the second coil; and the first extraction electrode layer is located at the first a winding terminal on the outer side of the coil is electrically connected; and a second extraction electrode layer is electrically connected to a winding end located outside the second coil, the first coil, the second coil, the conduction layer, and the first An extraction electrode layer and the second extraction electrode layer are integrally formed, the first extraction electrode layer having a first side surface portion formed on a first side surface of the insulating substrate, and a first upper surface portion from the first side surface portion Extending from the upper surface of the insulating base material and integrally connected to the winding end of the first coil; and the first lower surface portion from the first side surface portion to the insulating substrate Extendingly, the second extraction electrode layer has a second side surface portion formed on a second side surface of the insulating base material different from the first side surface, and a second lower surface portion that is insulated from the second side surface portion The lower surface of the substrate extends and is integrally coupled to the winding end of the second coil. The magnetic element according to claim 1, wherein the first upper surface portion and the first lower surface portion of the first extraction electrode layer and the second lower surface portion constituting the second extraction electrode layer are Formed thicker than the first coil and the second coil; a first magnetic layer is disposed on the upper surface of the first coil, and a second magnetic layer is disposed on a lower surface side of the second coil; and the surfaces of the first magnetic layer and the first upper surface are formed substantially on the same surface. Or the surface of the first upper surface portion protrudes from the surface of the first magnetic layer further away from the insulating substrate; the surfaces of the second magnetic layer, the first lower surface, and the second lower portion are substantially the same The surface formation or the surfaces of the first lower surface portion and the second lower surface portion protrude from the surface of the second magnetic material layer in a direction away from the insulating base material. The magnetic element according to claim 2, wherein the first upper surface portion and the first lower surface portion of the first extraction electrode layer and the second lower surface portion constituting the second extraction electrode layer are The inner layer has an inner layer having substantially the same thickness as the first coil and the second coil, and an outer layer formed by overlapping the inner layer; and the inner layer is formed integrally with the outer layer. The magnetic element according to claim 3, wherein the inner layer and each of the coils are composed of a foil formed on a surface of the insulating base material and a first plating layer formed by being combined with the foil. The outer layer is formed by a second plating layer formed by overlapping the first plating layer; the first side surface portion of the first extraction electrode layer and the second side surface portion of the second extraction electrode layer are respectively The first plating layer is formed of a laminated structure of the second plating layer. The magnetic element according to claim 4, wherein the first plating layer is an electroless plating layer, and the second plating layer is an electrolytic plating layer. The magnetic element according to claim 1, wherein the first coil and the first upper surface portion of the first extraction electrode layer have a first foil formed on an upper surface of the insulating substrate, and the first The second coil, the first lower surface portion of the first extraction electrode layer, and the second lower surface portion of the second extraction electrode layer have a second foil formed on a lower surface of the insulating substrate, and the first foil body The surface of the second foil and the surface of the second foil are superposed to form a plating layer, and the first extraction electrode layer has a surface from the first foil through the first side of the insulating substrate until the second a plating layer formed on a surface of the foil to constitute the first upper surface portion, the first side surface portion, and the first lower surface portion, and the second extraction electrode layer has the first surface from the insulating substrate The plating layer formed on the side surface up to the surface of the second foil body constitutes the second side surface portion and the second lower surface portion. The magnetic element according to claim 1, wherein the first extraction electrode layer is formed to have substantially the same length as the first side surface, and the second extraction electrode layer is formed to have substantially the same length as the second side surface. The magnetic element according to claim 1, wherein a pad is formed on an outermost surface of the first extraction electrode layer and the second extraction electrode layer. The magnetic element according to claim 1, wherein the second extraction electrode layer has: the second side portion; and the second The upper surface portion is formed to extend from the second side surface portion toward the upper surface of the insulating base material, and is formed by the same structure as the first upper surface portion, and the second lower surface portion. The magnetic element according to claim 1, wherein the first coil has a first direction from the first winding end and a first direction, and the second coil has an initial direction from the winding start end. The extending direction is a second direction opposite to the first direction, and the second side surface of the insulating substrate is located on a side opposite to the first side surface, and the first direction and the second direction are The longitudinal direction of the first side surface and the second side surface of the insulating base material is orthogonal to each other. A method for producing a magnetic element, comprising: a first step of preparing a first foil body on an upper surface of an insulating base material and forming a second foil body on a lower surface thereof to be cut into a plurality of magnetic bodies The insulating substrate of the device has a through hole formed at a position between the regions of the insulating substrate which is a magnetic element, and a through hole is formed in a region where each magnetic element is formed. In the second step, the first foil and the first foil and the The second foil is formed to form a first plating layer by weight, and a conductive layer based on the first plating layer is formed in the through hole, and a surface of the first foil is formed from the surface of the first foil to the side wall of the through hole. And forming a surface of the second foil to form the first plating layer; and a third step of forming the first foil body and the first plating layer on an upper surface side of the insulating substrate by using a lithography technique Made of a coil, and a second coil having the second foil and the first plating layer formed on a lower surface side of the insulating base material, and at this time, is located inside the first coil and the second coil Each of the inner winding ends is formed integrally with the conductive layer, and a first extraction electrode layer is formed to form a second extraction electrode layer, wherein the first extraction electrode layer has a first side surface portion formed in and a first side wall surface of the through hole corresponding to the first side surface of the insulating base material; and a first upper surface portion extending from the first side surface portion toward the upper surface of the insulating base material and located at the first coil The outer winding end is integrated; and the first lower surface portion extends from the first side surface portion toward the lower surface of the insulating base material; and the second extraction electrode layer has a second side surface portion formed to be insulated from the foregoing a second side wall surface of the through hole corresponding to the second side surface of the first side surface; and a second lower surface portion extending from the second side surface portion to the lower surface of the insulating substrate Integrated with and located outside of the second coil winding terminal; a fourth step, wherein the insulating substrate is cut to obtain a plurality of the magnetic elements. The method of manufacturing a magnetic element according to claim 11, wherein the first step of the first extraction electrode layer and the second extraction electrode layer is between the third step and the fourth step a fifth step of forming a second plating layer on the surface of the plating layer, and after the fifth step, the first magnetic layer is superposed on the upper surface side of the first coil and is on the lower surface side of the second coil coincide a sixth step of providing the second magnetic layer; the surfaces of the first magnetic layer and the first upper surface are substantially the same surface, or the surface of the first upper surface is further oriented than the surface of the first magnetic layer a direction protruding away from the insulating base material; wherein each surface of the second magnetic layer, the first lower surface portion, and the second lower surface portion is substantially the same surface, or each of the first lower surface portion and the second lower surface portion The surface protrudes from the surface of the second magnetic layer in a direction away from the insulating substrate. The method of manufacturing a magnetic element according to claim 11, wherein a pad is formed on an outermost surface of the first extraction electrode layer and the second extraction electrode layer. The method of manufacturing a magnetic element according to claim 11, wherein the second extraction electrode layer forms a second upper surface portion together with the second side surface portion and the second lower surface portion, the second upper surface The portion extends from the second side surface portion toward the upper surface of the insulating base material, and has the same structure as the first upper surface portion.