JPH03291905A - Chip type inductance element and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an element at a low cost wherein structure is simple and mass- productivity is superior, by laminating ring type magnetic sheets on which surfaces conductor lines are formed, and forming a toroidal coil pattern by connecting the above conductor lines by using the outer peripheral edge part and the hole edge part of each sheet. CONSTITUTION:Ring type magnetic sheets 1a-1d on which surfaces conductor lines 2-34 are formed are laminated, and the above conductor lines 2-34 are connected by using the outer peripheral edge part and the hole edge part of each of the sheets 1a-1d, thereby forming a toroidal coil type pattern. The following are provided; a process wherein the conductor lines 2-34 are formed on the surfaces of the ring type magnetic material green sheets 1a-1d, a process wherein the above sheets 1a-1d are laminated and a toroidal coil type pattern is formed by connecting the above conductor lines 2-34 by using the outer peripheral edge part and the hole edge part of each of the sheets 1a-1d, a process wherein, after the above laminated body is sandwiched between protective green sheets and bonded with pressure, baking is performed en bloc, and a process wherein outer electrodes connected with both ends of the above toroidal coil type pattern are formed on the surface of the above laminated body which has been baked en bloc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chip-type inductance element used in various electronic circuits and a method for manufacturing the same.

Conventionally, this type of inductance element has a magnetic core consisting of a cylindrical or prismatic body and flanges provided at both ends of the body, and a conductor winding. An inductance element, a so-called wire-wound inductance element, is known in which a wire is wound around the body of the magnetic core and the terminal end of the conductor winding is connected to an electrode formed on the flange of the magnetic core.

Alternatively, as described in Japanese Unexamined Patent Publication No. 55-91103, magnetic material and conductive patterns are printed alternately,
An inductance element in which a coil-shaped pattern is formed by connecting the conductor patterns of each layer, a so-called multilayer inductance element, is known.

By the way, these conventional chip-type inductance elements, both of the wire-wound type and the laminated type, have a problem in that their structure and manufacturing process are complicated, making them less suitable for mass production, and resulting in high manufacturing costs.

Therefore, the object of the present invention is to have a simple structure, excellent mass productivity, and
Moreover, it is an object of the present invention to provide a chip-type inductance element that is inexpensive to manufacture and a method for manufacturing the same.

In order to solve the above-mentioned problems, the chip-type inductance element according to the present invention has a structure in which ring-shaped magnetic sheets with conductor tracks formed on their surfaces are laminated, and the outer peripheral edge and hole edge of each sheet are laminated. The conductor line is connected to form a toroidal coil pattern.

With the above configuration, the toroidal coil pattern is disposed on the surface of the ring-shaped magnetic body of the laminated structure, so when IIJ flows through the toroidal coil pattern, most of the generated magnetic flux is inside the ring-shaped magnetic body. Through this, the same function as a so-called normal cored toroidal coil is exhibited.

Furthermore, the method for manufacturing a chip-type inductance element according to the present invention includes (a) forming a conductor line on the surface of a ring-shaped magnetic green sheet; (b) laminating the sheets and forming an outer peripheral edge of each sheet; (c) sandwiching and pressing the laminate between protective green sheets and then integrally firing the laminate; d) A step of providing external electrodes connected to both ends of the toroidal coil pattern on the surface of the integrally fired laminate. According to this method, the work of forming a conductor track on the surface of a ring-shaped magnetic green sheet can be carried out independently and in parallel for each sheet. There is no longer a need to stack the parts one after the other, which shortens the process period and simplifies the manufacturing process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of a chip-type inductance element and a method for manufacturing the same according to the present invention will be described with reference to the accompanying drawings. In this example, an inductance element with a toroidal coil pattern having three turns will be explained, but the width of the conductor line,
By changing the formation position and number of windings, an inductance element with a desired number of turns can be obtained.

First, as shown in FIG. 1, rectangular ring-shaped magnetic green sheets 1a, ib, 1c+ld are prepared.

These magnetic sheets 18 to 1d are made of, for example, Fe, O,
Ferrite magnetic powder, whose main component is ferrite magnetic powder, is kneaded with a binder, a solvent, etc. to form a paste, and the paste is formed into a thin sheet with a thickness of tens to several tens of micrometers. Rectangular holes IA, IB, IC, and ID are formed in the center portions of the sheets 1a to 1d by punching or the like.

Next, conductor lines 2, 3, and 4.degree. 5 are formed on the upper and lower surfaces of the sheet la, the outer peripheral end surface, and the hole wall surface using a method such as screen printing using silver paste or the like. Conductor line 2 is sheet 1a
One terminal end extends to the outer peripheral end surface of the right front side of the sheet 1a to form an extraction electrode 2a, and the other terminal end 2b extends from the right front wall surface of the hole IA to the upper surface. The conductor line 3 is formed on the lower surface of the front side of the sheet la near the left of the center, and one terminal end 3a wraps around from the outer peripheral end surface of the front side of the sheet 1a near the left of the center to the upper surface, and the other terminal end 3
b wraps around from the left front side wall surface of hole IA to the upper surface.

The conductor line 4 is formed on the lower left rear side of the sheet la, one terminal end 4a wraps around from the outer peripheral end surface of the left central part of the sheet la to the upper surface, and the other terminal end 4b runs from the left rear wall surface of the hole IA to the upper surface. It's going around. The conductor line 5 is formed on the sheet 1a
is formed on the lower surface of the right back side of the sheet 1a, and one terminal end 5a is
The other terminal end extends to the right outer peripheral end surface of the sheet la, forming an extraction electrode 5b.

Similarly, conductor lines are formed on sheets lb, lc, and ld. Conductor tracks 12.14.1 in sheet 1b
6 are formed on the wall surface of hole IB, and each conductor line 12, 14 .
Both ends of the sheet 16 wrap around the upper or lower surface of the sheet 1b.

Conductor lines 13, 15, 17 are formed on the outer peripheral end surface of the sheet 1b, and both ends of each conductor line 13, 15, 17 extend around the upper or lower surface of the sheet 1b. sheet 1
Conductor lines 22, 24, and 26 are completely formed on the wall surface of hole IC in c, and conductor lines 23, 25, and 27 are formed on the outer peripheral end surface.

Both ends of each of the conductor lines 22 to 27 extend around the upper or lower surface of the sheet 1c. Further, conductor lines 32, 33, 34 are completely formed on the upper surface of the sheet 1d, and both ends of each conductor line 32, 33, 34 extend from the hole wall surface of the hole ID and the outer peripheral end surface of the sheet 1d to the lower surface. At this time,
The conductor lines 2, 3, 4, etc. are formed so as to be connected when the sheets 1a to 1d are stacked. For example, the conductor line 12 that can be formed on the sheet 1b is formed at a position that matches the terminal end 2b of the conductor line 2. In addition, the conductor line 13
is formed at a position shifted to the right with respect to the terminal end 3a of the conductor line 3. Here, since the work of forming the conductor lines 2, 3, 4, etc. on the surface of each sheet 18 to 1d can be carried out independently and in parallel for each sheet, magnetic material and conductor patterns can be formed as in conventional laminated inductance elements. There is no longer a need to stack the parts one after another, which shortens the process period and simplifies the manufacturing process.

Next, the sheets la to 1d on which conductor lines are formed are stacked to form a laminate 40. At this time, the terminal end 2b of the conductor line 2 formed on the sheet 1a is connected to the conductor line 12 formed on the sheet lb stacked thereon, and the conductor line 12-22-32-23- 13-
3-14-24-33-25-15-4-16-26-
34-27-17-5 to form a three-turn toroidal coil pattern.

In this way, a three-turn toroidal coil pattern is provided on the surface of the laminate 40, and both ends of the pattern are connected to the sheet l.
This becomes the extraction electrodes 2a and 5a of the conductor lines 2 and 5 formed in a.

Next, as shown in FIG. 2, plate-shaped protective green sheets 41 and 41 are stacked on top and bottom of this laminate 40.

The protective green sheet 41 may be made of a magnetic material like the sheets 18 to 1d, or may be made of an insulating material as the case may be. The laminate 40 sandwiched between the protective green sheets 41 is set in a press and then pressurized, and the green sheets 18 to 1d and 41 are pressed together. The thus compressed material is placed in a firing furnace and fired integrally at a predetermined firing temperature and time to obtain a sintered body 46.

The sintered body 46 is also used as the lead electrode 2a of the conductor line 2.5,
The conductor lines 3 and 13 are exposed on the outer peripheral end surface except for 5b.
．． Cover 23, 32, etc. with an insulating material. As the insulating material, for example, a paste made of glass powder and a binder, or a paste made of powder such as alumina is used, and the material is applied to the outer peripheral end surface of the sintered body by means such as dipping or printing and baked.

Next, as shown in FIG. 3, the sintered body 46 is formed with external electrodes 47 and 48 connected to the extraction electrodes 2a and 5b, respectively. The external electrodes 47 and 48 may be formed using metal caps, or may be formed by applying silver paste or the like and then firing it. In this way, a chip-type inductance element that can be surface-mounted on a printed wiring board or the like is obtained.

In the resulting chip-type inductance element, when current flows through its toroidal coil pattern, most of the generated magnetic flux passes through the ring-shaped magnetic material of the laminated structure, and exhibits the same function as a normal cored toroidal coil. .

Note that the chip-type inductance element and the manufacturing method thereof according to the present invention are not limited to the embodiments described above, and can be variously modified within the scope of the gist thereof.

The protective sheet 15 may have a ring shape similar to the shape of the magnetic sheet 1.

Further, a conductive pattern constituting a part of the external electrode may be formed on the surface of the protective sheet 15 before lamination.

As described above, according to the present invention, a toroidal coil pattern can be disposed on the surface of the ring-shaped magnetic material of the laminated structure, so when a current flows through this toroidal coil pattern, the generated magnetic flux is Most of the magnetic material passes through the inside of the ring-shaped magnetic body, exhibiting the same function as a so-called normal cored toroidal fill, and providing a chip-type inductance element with a simple structure.

Furthermore, when manufacturing the inductance element according to the present invention,
After forming a conductor line on the surface of a ring-shaped magnetic green sheet, if the sheets are laminated and fired together with a protective green sheet, the work of forming a conductor line on the surface of the magnetic green sheet can be done independently for each sheet. This eliminates the need to stack magnetic material and conductive patterns in sequence as in conventional multilayer inductance elements.
The process period is shortened, the manufacturing process is simplified, and a chip-type inductance element with excellent mass productivity and low manufacturing cost can be obtained.

[Brief explanation of drawings]

1 to 3 show an embodiment of the chip-type inductance element and its manufacturing method according to the present invention. FIG. 1 is an exploded perspective view of a magnetic green sheet portion, and FIG. A perspective view to be explained, and FIG. 3 is a perspective view of a completed product. 1a* 1be 1c+ ia...Ring-shaped magnetic green sheet, 2, 3, 4, 5.12.13.1
4, 15.16.17.22, 23.24.25.26
゜27, 32.33.34... Conductor line, 41...
Protective green sheet, 47.48...external electrode. District map

Claims (2)

[Claims] 1. A chip-type inductance element characterized in that ring-shaped magnetic sheets each having a conductor line formed on its surface are laminated, and the conductor line is connected at the outer peripheral edge of each sheet and at the hole edge to form a toroidal coil pattern. . 2. a step of forming a conductor line on the surface of a ring-shaped magnetic green sheet; a step of stacking the sheets and connecting the conductor lines at the outer periphery and hole edge of each sheet to form a toroidal coil pattern; , a step of sandwiching and press-bonding the laminate between protective green sheets, and then integrally firing it; and a step of providing external electrodes connected to both ends of the toroidal coil pattern on the surface of the integrally fired laminate. , A method for manufacturing a chip-type inductance element, comprising: