JPH08130144A - Manufacturing for chip-type inductor - Google Patents

Abstract

PURPOSE: To provide a manufacturing method for a chip-type inductor with uniform frequency characteristics in impedance in mass production without a decrease in impedance according to the stress, by preventing stress to a magnetic body when compression is caused in a baking step. CONSTITUTION: In a manufacturing method, a kneaded material 8 made of magnetic raw powder and binder is fed under pressure to an extrusion molding machine 5, in which a linear conductor is covered with an outer coating of kneaded material 8 to mold a bar-shaped body 9. After that the bar-shaped body 9 is baked to form a chip-type inductor. In these steps, the linear conductor is coated with an organic material before the molding step, in which the outer coating body around the linear conductor is formed from the kneaded material 8, and the organic coating material is removed at a baking step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type inductor using a fired magnetic core, which is used for removing harmonics and electromagnetic interference noise generated from signal lines.

[0002]

2. Description of the Related Art Conventionally, in order to remove harmonic noise, a conductive wire such as a platinum wire is previously inserted into a molding die, and then a kneading material obtained by kneading a binder and ferrite powder is supplied to the molding die. A molded body containing a conductive wire is extruded from the die of the mold, and the molded body is fired to form a linear conductive wire 1 as shown in FIG.
An inductor is known in which an inductor main body 2 having a built-in capacitor is created and external electrodes 3 are formed at both ends thereof.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
There is a problem that stress is applied to the magnetic core due to contraction when the kneading material is hardened, the impedance value is reduced according to the stress, and the frequency characteristic of the impedance value varies during mass production.

It is an object of the present invention to eliminate the above-mentioned problems in a chip-type inductor containing a wire conductor and a coil conductor.

[0005]

In order to achieve the above-mentioned object, the invention according to claim 1 forms a jacket with a kneading material which surrounds a linear conductor wire and kneads a magnetic material powder and a binder. In the method for manufacturing a chip-shaped inductor formed and fired, an organic material is coated on the outer periphery of the linear conductor before surrounding the linear conductor and forming a jacket with a kneading material. , Characterized by eliminating organic matter.
According to a second aspect of the present invention, a winding core is formed from a kneading material obtained by kneading a magnetic material powder and a binder, and a conducting wire having an outer periphery coated with an organic substance is wound around the winding core in a coil shape, and then the conducting wire is wound. An envelope is formed of the kneading material surrounding the turned core.
It is characterized in that it is formed by firing, and the organic substance disappears during firing. In the invention according to claim 2, it is preferable that the organic material is a material having a high friction coefficient. According to a fourth aspect of the present invention, a winding core is formed from a kneading material obtained by kneading a magnetic material powder and a binder, an organic material is applied to the winding core, and then the conductive wire is wound into a coil shape, and the conductive wire is wound. It is characterized in that the wound core is surrounded to form an outer cover by the kneading material and then fired, and the organic matter disappears during firing. According to a fifth aspect of the present invention, a winding core is formed from a kneading material obtained by kneading a magnetic material raw material powder and a binder, a conductive wire is wound around the winding core in a coil shape, and then an organic substance is applied to the conductive wire and the winding core. It is characterized in that it surrounds a winding core around which the conductor wire is wound to form an outer cover from the kneading material and then fires it, and the organic matter disappears during firing. In the invention according to claim 1, 2, 3, 4 or 5, it is preferable that the conducting wire is a bundled wire.

[0006]

In the invention according to claim 1, the outer cover shrinks when fired, but organic substances present between the outer cover and the conductive wire disappear and a void is formed. The shrinkage is absorbed, and no stress is applied to the outer body by the conductive wire. . In the invention according to claim 2, 4 or 5, the organic substance coating the outer periphery of the conductor wire, the organic substance applied to the core, or the conductor wire wound in a coil shape and the organic substance applied to the core disappears during firing. Since voids are formed there, the shrinkage is absorbed by the voids even if the sheath is shrunk by firing, and stress due to shrinkage is not applied to the sheath. In the invention described in claim 1, 2, 3, 4 or 5, if the conductor wire is a bundle wire, the conductor wire is more easily bent than a single conductor wire having the same cross-sectional area. It is effectively absorbed in the voids due to the disappearance of organic matter through the deformation. Claim 2
In the invention described above, when the organic material coating the outer circumference of the conductive wire is a material having a high friction coefficient, it is possible to prevent the winding of the conductive wire wound around the winding core when forming the jacket.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a method of manufacturing the chip inductor shown in FIG. First, the conductor 4 coated with an organic material such as rubber or plastic is inserted into the through hole 6 of the extrusion molding machine 5, and the kneading material 8 in which the magnetic material powder B and the binder S are evenly kneaded by the kneading machine 7 is extruded. When pressure-fed into the molding machine 5, an outer jacket body made of the kneading material 8 surrounding the conductor wire 4 is formed from the die die, and the rod body 9 is fed. The rod 9 is cut according to the size of the firing furnace or the shape of the setter to be laid under it, fired at 600 to 1000 ° C., for example 900 ° C., and cut with a cutter according to the size of each inductor. The individual inductor bodies 2 thus cut are barrel-polished with barrel powder and water to have rounded corners. Next, the silver paste is applied to both end faces of the inductor body 2 and the end portions of the outer peripheral surface continuing to the inductor body 2 and baked to form the external electrodes 3,
3 is formed. As a result, the terminals 10 and 10 of the lead wire 1 and the external electrode 3 are connected. The silver layer of the external electrode 3 is nickel plated and solder plated. Since the organic substance disappears and a void is formed by the firing, even if the envelope shrinks, the shrinkage is absorbed by the void, the stress due to the shrinkage is not applied to the envelope, and the impedance decreases. do not do.

FIG. 2 is an explanatory view of a method for manufacturing the chip inductor shown in FIG. The chip inductor of FIG. 3 is one in which external electrodes 3 are formed at both ends of an inductor body 2 having a coil-shaped conductor 1a built therein. The manufacturing method will be described. When the kneading material 8 obtained by uniformly kneading the magnetic material powder B and the binder S by the kneading machine 7 is pressure fed into the extrusion molding machine 5a, the kneading material is formed from the die part of the die. A rod 11 which is a winding core is delivered, and a conductor 4 coated with an organic substance is wound around the rod 11 by a winding machine 12 in a coil shape. When the rod 11 around which the conducting wire 4 is wound is inserted into an extrusion molding machine 5b into which the kneading material 8 is fed under pressure and moved, the rod 11 around which the conducting wire 4 is wound is surrounded by the kneading material. A body is formed. This is cut according to the size of the firing furnace or the shape of the setter to be laid below, and 600 to 1000 is cut.
Baking at a temperature of 900 ° C., for example, and cutting with a cutter according to the size of each inductor. The individual inductor bodies 2 thus cut are barrel-polished with barrel powder and water in the same manner as described above, so that the corner portions are rounded. Next, the silver paste is applied to both end faces of the inductor body 2 and the end portions of the outer peripheral surface continuing to the same, and baked to form the external electrodes 3 and 3. When a material having a high friction coefficient such as rubber is used as the organic material, the conductor wire 4 wound around the rod body 11 can prevent the collapse of the winding when the outer cover is formed, and in mass production. , The impedance value does not vary.

In FIG. 2, instead of using the conductor 4 coated with an organic substance, an organic substance is applied to the rod body 11 (not shown) delivered from the die of the die of the extrusion molding machine 5a (not shown), and then the conductor 1 is attached. It may be wound by the winding machine 12 and inserted into the extrusion molding machine 5b and moved, or the extrusion molding machine 5a.
The conductor 1 is wound around the rod 11 delivered from the die part of the die by the winding machine 12, and then the conductor 1 and the rod 11 are coated with an organic substance (not shown) and inserted into the extrusion molding machine 5b. You may move it. In any case, the same effect as that of the above embodiment can be obtained. In the above-mentioned embodiment, when a bundled wire is used for the conductive wire 1, it is easier to bend than when a single conductive wire 1 having the same cross-sectional area is used. Therefore, the organic matter disappeared between the conductive wire 1 and the rod 11 during firing. The contraction of the outer cover is more effectively absorbed in the void due to the bending of the conductive wire.

[0010]

EFFECTS OF THE INVENTION According to the present invention, since the stress is not applied to the magnetic material due to the shrinkage during the firing of the magnetic material, the impedance value does not decrease according to the stress, and the mass production is achieved. In this case, there is an effect that the frequency characteristic of impedance does not vary.

[Brief description of drawings]

FIG. 1 is an explanatory view of a method for manufacturing a chip inductor according to the present invention.

FIG. 2 is an explanatory view of another method for manufacturing a chip inductor according to the present invention.

FIG. 3 is a perspective view of another chip-type inductor described above.

FIG. 4 is a perspective view of an example of a conventional chip inductor.

[Explanation of symbols]

1 conductor 1a
Coiled conductor 2 Inductor body 3
External electrode 4 Conductive wire having organic matter 5, 5a, 5b Extrusion molding machine 8
Kneading material 9 Rod which is a jacket 11 Rod which is a winding core

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuhiro Umeyama 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Electric Co., Ltd. (72) Inventor Kenichiro Nogi 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Company

Claims (6)

[Claims] 1. A method for manufacturing a chip-shaped inductor, comprising enclosing a linear conductor and forming an outer cover with a kneading material obtained by kneading a magnetic material powder and a binder, followed by firing, and enclosing the linear conductor. Then, before forming an outer cover with a kneading material, the outer periphery of the linear conductor is coated with an organic substance, and at the time of firing,
A method for manufacturing a chip-type inductor, characterized in that organic substances disappear. 2. A winding core is formed from a kneading material obtained by kneading a magnetic material powder and a binder, and a conductive wire whose outer periphery is coated with an organic material is wound around the winding core in a coil shape, and then the conductive wire is wound. A method for manufacturing a chip-type inductor, comprising surrounding a winding core to form an outer cover with the kneading material, and then firing, wherein the organic substance disappears during firing. 3. The method for manufacturing a chip inductor according to claim 2, wherein the organic substance is a material having a high friction coefficient. 4. A winding core is formed from a kneading material obtained by kneading a magnetic material raw material powder and a binder, and an organic substance is applied to the winding core.
It is characterized in that the conductive wire is wound in a coil shape, the winding core around which the conductive wire is wound is surrounded to form an outer cover body by the kneading material, and then firing is performed, and the organic matter disappears during firing. Chip inductor manufacturing method. 5. A winding core is formed from a kneading material obtained by kneading a magnetic material raw material powder and a binder, a conductive wire is wound around the winding core in a coil shape, and an organic substance is applied to the conductive wire and the winding core. A method for manufacturing a chip-type inductor, comprising surrounding a winding core around which a conductive wire is formed to form an outer cover from the kneading material, and then firing, wherein the organic matter disappears during firing. 6. The method of manufacturing a chip inductor according to claim 1, wherein the conductive wire is a bundled wire.