JP2007227729A - Inductance component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve miniaturization of an inductance component having a notch on a magnetic layer. <P>SOLUTION: In order to achieve this purpose, the inductance component is provided with a base 6 having a through hole 7, a coil 8A formed in the base 6 in an external periphery direction of the through hole 7, terminals 8B, 8C electrically connected to the coil, and a magnetic layer 9 formed on the internal peripheral surface of the through hole 7. The through hole 7 has a convex portion 7A in its internal peripheral surface, and one part of the base 6 is exposed from one part of the magnetic layer 9 formed on the convex portion 7A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inductance component used in, for example, a power supply circuit of a mobile phone.

  Conventionally, as shown in FIG. 32, this type of inductance component is provided with a through-hole portion 2 in the center of a sheet-like element body 1, and a coil 3A and a terminal 3B are arranged in the outer peripheral direction of the through-hole portion 2. The magnetic layer 4 is formed on the upper and lower surfaces of the element body 1 and the inner peripheral surface of the through-hole portion 2.

  Then, as shown in FIG. 33 which is a top view, a notch 4A is formed on a part of the magnetic layer 4 formed on the inner peripheral surface of the through-hole portion 2 by using a laser or a puncher, thereby A part of the eddy current was prevented from being generated in the magnetic layer 4 formed on the inner peripheral surface of the through-hole portion 2 by exposing a part thereof.

As prior art document information relating to this application, for example, Patent Document 1 is known.
JP 2005-317604 A

  Such a conventional inductance component has a problem that there is a limit to miniaturization.

  That is, in the above-described conventional configuration, when the cutout 4A is formed using a laser or a puncher, only the element body 1 existing in the outer peripheral direction of the magnetic layer 4 formed on the inner peripheral surface of the through-hole portion 2 is used. Therefore, in order to avoid accidentally cutting out the outer peripheral coil layer 3A, a sufficient distance d1 from the innermost periphery of the coil layer 3A to the outer periphery of the through-hole portion 2 needs to be taken. There was a limit.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the size of an inductance component having a notch in a magnetic layer.

  In order to achieve this object, the present invention provides an element body having a through-hole portion, a coil formed in the element body in the outer peripheral direction of the through-hole portion, and a terminal electrically connected to the coil. And a magnetic layer formed on the inner peripheral surface of the through-hole portion, the through-hole portion having a convex portion on the inner peripheral surface, and the magnetic layer formed on the convex portion. Inductance components in which a part of the element body is exposed from a part are used.

  The inductance component of the present invention has a structure in which the through hole portion has a convex portion on the inner peripheral surface thereof, so that a part of the element body is removed by removing the magnetic layer formed on the convex portion using a laser or a puncher. When exposed, the possibility of notching the coil in the outer circumferential direction can be reduced, and it is not necessary to take the distance from the innermost circumference of the coil to the outer circumference of the magnetic layer more than necessary. Can be realized.

(Embodiment 1)
Hereinafter, an inductance component according to Embodiment 1 of the present invention will be described with reference to the drawings.

  In FIG. 1, a through-hole portion 7 is provided at substantially the center of the sheet-like element body 6. A coil 8A is provided in the outer peripheral direction of the through-hole portion 7, and terminals 8B and 8C are provided on the outermost peripheral portion of the coil 8A. Vias 8D are respectively formed in the element body 6 between the planar coils 8AA and 8AB constituting the coil 8A, and a magnetic layer 9 is formed on the upper and lower surfaces of the element body 6 and the inner peripheral surface of the through-hole portion 7. Formed and configured.

  Here, the coil 8A may be a single layer, but in the present embodiment, the coil 8A is composed of two layers of planar coils 8AA and 8AB. The upper planar coil 8AA is spirally wound in the direction (inner circumferential direction) from the terminal 8C toward the through-hole portion 7, and the innermost circumferential portion of the planar coil 8AA and the innermost circumferential portion of the lower planar coil 8AB are formed. The planar coil 8AB is connected by a via 8D, and the coil 8A is configured by winding the planar coil 8AB in a spiral shape in a direction (peripheral direction) toward the terminal 8B.

  Here, the planar coils 8AA and 8AB are preferably wound in the same direction. This is to realize a large inductance value without canceling out the magnetic flux generated in the planar coil 8AA which is the upper layer of the coil 8A and the magnetic flux generated in the planar coil 8AB which is the lower layer.

  Here, as shown in FIG. 2, which is a top view, a convex portion 7A is provided on the inner peripheral surface of the through-hole portion 7, and the magnetic layer 9 is formed along this shape.

  Then, as shown in FIG. 3 which is a top view, a part of the element body 6 is exposed by forming a notch 9A to remove a part of the magnetic layer 9 formed on the convex part 7A. By doing so, the current flow through the magnetic layer 9 can be blocked by the notch 9A, and as a result, the generation of eddy currents in the magnetic layer 9 in the inner peripheral surface of the through-hole portion 7 is reduced. be able to.

  And as shown in FIG. 4, only the terminals 8B and 8C are left outside, and the whole is covered with the insulating part 10, thereby preventing unnecessary electrical connection with other components.

  With such a configuration, when the notch 9A is formed as shown in FIG. 3, it is possible to reduce the possibility of accidentally notching the coil 8A, so the through hole portion 7 extends from the innermost periphery of the coil 8A. It is not necessary to take the distance d2 to the outer periphery more than necessary, and a small inductance that prevents the generation of eddy current can be obtained.

  When the magnetic layer 9 is continuously formed from the upper surface and the lower surface of the element body 6 to the inner peripheral surface of the through hole portion 7, a magnetic gap between the upper and lower surfaces of the element body 6 and the inner peripheral surface of the through hole portion 7 is formed. Can be eliminated, and the leakage magnetic flux can be reduced.

  The coil 8A may be a single layer, but a larger inductance value can be realized by using a structure in which two or more plane coils 8AA and 8AB are stacked as shown in FIG. 4 of the present embodiment. desirable.

  The cross section of the coil 8A may be circular instead of square, but the square is desirable because the coil cross-sectional area can be increased, and the copper loss can be reduced.

  It is desirable that the planar coils 8AA and 8AB have a thickness of 10 μm or more because it can cope with a large current.

  In the present embodiment, the insulating portion 10 is also formed in the inner peripheral direction of the magnetic layer 9 formed on the inner peripheral surface of the through hole portion 7. However, instead of the insulating portion 10, a magnetic material or By filling the resin ferrite or the like, it is possible to improve the magnetic characteristics.

  Note that an epoxy resin, a silicon resin, an acrylic resin, an organic resin material of a mixture thereof, or the like can be used for the insulating portion 10. Moreover, it is desirable to mix these organic materials with an inorganic filler because heat resistance and mechanical strength can be improved.

  For the magnetic layer 9, it is desirable to use a magnetic material made of iron, nickel, cobalt or the like. In particular, in the composition ratio of the magnetic layer 9, when the iron content is 30% or more, a high saturation magnetic flux density is obtained, which is desirable as an inductor used in a power supply system. Further, it is desirable that the nickel content be near 20% because high permeability is obtained and a large inductance value can be obtained.

  In addition, the generation of eddy current can be suppressed by increasing the specific resistance value of the magnetic layer 9.

  Specifically, a configuration in which a magnetic material is mixed in a high resistance film such as zinc oxide, cerium oxide, copper oxide, iron oxide, ceramic, or a configuration in which a high resistance oxide is mixed in a magnetic material, Or the structure etc. which oxidize the magnetic material itself in the magnetic body layer 9 are mentioned.

  It should be noted that the eddy current can also be prevented from occurring by making the magnetic layer 9 a multilayer structure having the high resistance layer 9C as shown in FIG. In FIG. 5, a metal layer 9A is formed on the upper surface of the element 6 by electroless plating or the like, and a metal magnetic layer 9B is formed on the upper layer of the metal layer 9A by electrolytic plating or the like. A high resistance layer 9C is formed on the upper layer by electrolytic plating or the like, and a metal magnetic layer 9D is formed on the high resistance layer 9C by electrolytic plating or the like. Thus, by interposing the high resistance layer 9C in the magnetic layer 9, generation of eddy currents in the thickness direction of the magnetic layer 9 can be prevented.

  Here, the metal layer 9A desirably uses a metal such as copper having excellent conductivity, and the metal magnetic layers 9B and 9D desirably employ iron, nickel, cobalt, or the like from the viewpoint of magnetic properties as described above. . For the high resistance layer 9C, it is desirable to use a metal oxide such as zinc oxide, copper oxide, cerium oxide or the like having a large specific resistance value. This is because the adhesion between the metal magnetic layers 9B and 9D can be improved by using the metal oxide.

  In addition, the magnetic characteristic can be further improved by mixing the magnetic material with the metal layer 9A.

  Next, a method for manufacturing the inductance component will be described.

  First, as shown in FIG. 6, a substrate 11 such as silicon is prepared.

  Next, as shown in FIG. 7, an insulating layer 12 is formed on the substrate 11 with a photoresist.

  Thereafter, as shown in FIG. 8, the upper surface of the element body forming portion 12 </ b> B excluding the substantially central portion 12 </ b> A in the insulating layer 12 is exposed. Here, the shape of the substantially central portion 12A is set to have a convex portion 7A as shown in FIG.

  Next, as shown in FIG. 9, an insulating layer 13 is formed on the entire upper surface of the insulating layer 12 with a photoresist.

  Thereafter, as shown in FIG. 10, the upper surface of the element body forming portion 13 </ b> C excluding the substantially central portion 13 </ b> A and the coil forming portion 13 </ b> B in the insulating layer 13 is exposed. Here, the shape of the substantially central portion 13A is set so as to have the convex portion 7A as shown in FIG.

  Next, as shown in FIG. 11, the substantially central portion 12A, the substantially central portion 13A, and the coil forming portion 13B shown in FIG. 10 are removed by development.

  Then, as shown in FIG. 12, after forming an underlayer (not shown) by electroless plating or the like on the upper surface of the substrate 11 and the exposed surfaces of the element forming part 12B and the element forming part 13C, electroplating is performed. A conductor 14 is formed.

  Next, as shown in FIG. 13, the conductor 14 shown in FIG. 12 is polished from above to expose the element body forming portion 13C on the upper surface. At this time, the conductor 14 enters the portion corresponding to the coil forming portion 13B shown in FIG. 10, and these become the planar coil 8AB and the terminal 8B shown in FIG. As this polishing method, a flat element forming portion 13C can be formed by using cutting or CMP.

  Thereafter, as shown in FIG. 14, the insulating layer 15 is formed of photoresist on the entire upper surface of the planar coil 8AB and the element body forming portion 13C. By using a photoresist, it is possible to form a thin insulating layer 15 having excellent planar uniformity and having a thickness of about 10 μm to 20 μm.

  Next, as shown in FIG. 15, the upper surface of the element body forming portion 15 </ b> C excluding the substantially central portion 15 </ b> A and the via forming portion 15 </ b> B in the insulating layer 15 is exposed. Here, the shape of the substantially central portion 15A is set so as to have the convex portion 7A as shown in FIG.

  Thereafter, as shown in FIG. 16, the insulating layer 16 is formed on the entire upper surface of the insulating layer 15 with a photoresist.

  Next, as shown in FIG. 17, in the insulating layer 16, the upper surface of the element body forming portion 16C excluding the substantially central portion 16A and the coil forming portion 16B is exposed. Here, as shown in FIG. 2, the shape of the substantially central portion 16A is set so as to have the convex portion 7A.

  Thereafter, as shown in FIG. 18, the substantially central portion 15A, the via forming portion 15B, the substantially central portion 16A, and the coil forming portion 16B shown in FIG. 17 are removed by development.

  Next, as shown in FIG. 19, after forming an underlayer (not shown) by electroless plating or the like on the upper surface of the conductor 14 shown in FIG. 18 and the exposed surfaces of the element body forming portions 15C and 16C, The conductor 17 is formed by plating.

  Then, as shown in FIG. 20, the conductor 17 shown in FIG. 19 is polished from above, and the element body forming portion 16C is exposed on the upper surface. At this time, the conductor 17 entering the portion corresponding to the coil forming portion 16B shown in FIG. 17 becomes the planar coil 8AA and the terminal 8C shown in FIG. 1, and enters the portion corresponding to the via forming portion 15B shown in FIG. The conductor 17 becomes the via 8D shown in FIG.

  Next, as shown in FIG. 21, an insulating layer 18 is formed of photoresist on the entire upper surface of the planar coil 8AA and the element body forming portion 16C.

  Then, as shown in FIG. 22, the upper surface of the element body forming portion 18B except the substantially central portion 18A in the insulating layer 18 is exposed. Here, the shape of the substantially central portion 18A is set so as to have the convex portion 7A as shown in FIG.

  Next, as shown in FIG. 23, the substantially central portion 18A shown in FIG. 22 is removed by development.

  Thereafter, the conductor 14 formed in the substantially central portions 12A and 13A shown in FIG. 10 and the conductor 17 formed in 15A and 16A shown in FIG. 17 are etched using an etching agent such as nitric acid as shown in FIG. The through hole portion 7 having the convex portion 7A as shown in FIG. 2 is formed.

  Next, as shown in FIG. 25, the substrate 11 is removed by hydrofluoric acid treatment or the like.

  Thereafter, as shown in FIG. 26, a mask 19 is formed on the side where the external terminal forming portion, that is, the terminals 8B and 8C are exposed.

  Next, as shown in FIG. 27, the base layer 20 is formed on the entire exposed surfaces of the element body forming portions 12B, 13C, 15C, 16C, and 18B and the mask 19 by electroless plating or the like.

  Thereafter, as shown in FIG. 28, the base layer 20 formed on the mask 19 is simultaneously removed by peeling the mask 19 shown in FIG. Examples of the method for removing the mask 19 include a method in which the mask 19 is immersed in an organic acid or alkaline resist stripping solution, or a method in which the mask 19 is removed by ashing with oxygen plasma.

  Next, as shown in FIG. 29, the magnetic layer 9 shown in FIG. 1 is formed by electroplating using the underlayer 20 as an electrode.

  At this time, as shown in FIG. 2, the magnetic layer 9 is formed along the inner peripheral surface of the through hole portion 7 provided in the element body 6, and is also formed on the convex portion 7 </ b> A in the through hole portion 7.

  Then, in order to remove the magnetic layer 9 on the convex portion 7A, a notch 9A is provided as shown in FIG. 3 using a laser or a puncher. By providing the notch 9A, a part of the element body 6 is exposed from a part of the notch 9A.

  Thereafter, as shown in FIG. 30, the insulating layer 10 shown in FIG. 4 is formed on the entire surface of the magnetic layer 9.

  Next, as shown in FIG. 31, pastes made of a mixture of resin and metal are used as external electrodes 8CC and 8BB, and are electrically connected to terminals 8C and 8B, respectively.

  In this way, an inductance component with reduced eddy currents generated in the magnetic layer 9 formed on the inner peripheral surface of the through hole portion 7 can be formed by a simple process such as formation of the notch 9A by a laser or a puncher. it can.

  The inductance component of the present invention is characterized by being small and generating less eddy currents in the magnetic layer, and is useful in various electrical devices.

Sectional drawing of the inductance component in Embodiment 1 of this invention The top view of the inductance component in Embodiment 1 of this invention The top view of the inductance component in Embodiment 1 of this invention Sectional drawing of the inductance component in Embodiment 1 of this invention Sectional drawing of the magnetic body layer of the inductance component in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional drawing which shows the manufacturing process of the inductance components in Embodiment 1 of this invention Sectional view of a conventional inductance component Top view of conventional inductance components

Explanation of symbols

6 Element 7 Through-hole 7A Convex 8A Coil 8B, 8C Terminal 9 Magnetic layer

Claims (7)

An element body having a through hole portion, a coil formed in the element body in the outer circumferential direction of the through hole portion, a terminal electrically connected to the coil, and an inner peripheral surface of the through hole portion are formed. The through-hole portion has a convex portion on its inner peripheral surface, and a part of the element body is exposed from a portion of the magnetic layer formed on the convex portion. Inductance component. The inductance component according to claim 1, wherein the through-hole portion is provided at substantially the center of the element body. The inductance component according to claim 1, wherein the second magnetic layer is formed on at least a part of the upper surface or the lower surface of the element body. The magnetic layer includes a metal layer, a first metal magnetic layer formed on the surface of the metal layer, a high resistance layer formed on the surface of the first metal magnetic layer, and a surface of the high resistance layer. The inductance component according to claim 1, comprising: a second metal magnetic layer formed on the substrate. The inductance component according to claim 4, wherein the first metal magnetic layer is made of at least one element of iron, nickel, and cobalt. The inductance component according to claim 4, wherein the high resistance layer is made of a material having a higher specific resistance than the first metal magnetic layer and the second metal magnetic layer. The inductance component according to claim 4, wherein the metal layer is composed of at least one element of iron, nickel, and cobalt.

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