JPS59152611A - Manufacture of chip inductor - Google Patents

Abstract

PURPOSE:To realize a mass-production of a chip inductor with a core flange part without cracked portion by a method wherein, one a winding core composed of a magnetic material, magnetic sheets whose width is smaller than the length of the winding core are wound and flange parts are formed to both ends of the winding core and the core is baked. CONSTITUTION:On a winding core 12, composed of a magnetic material, required number of magnetic sheets 13, whose width is smaller than the length of the winding core 12, are wound. After the winding core 12 is cut to the required length, it is baked and the core 14 is obtained. A conductor 17 is wound between flange parts 15 and 16 of the core 14 formed in such a way as mentioned above. The end 17a of the conductor 17 is positioned outside the flange part. Then internal electrodes 18, 19 are provided to both ends of the core 14 and finally a magnetic ferrite 20 and external electrodes 21 are provided. Because the flange parts 15, 16 are formed by winding the magnetic sheets 13, breaking caused by shaving is avoided so that this method is useful to be applied for mass-production.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a chip inductor.

Conventional structure and its problems The chip inductor is a square core rod or a round core rod, which is fired using a ferrite mainly made of F.203 as a magnetic material, and a heat-resistant insulator and resin are applied in this order. After winding the coated conductor wire to form a coil body, the coil body is heated to remove the coating resin and A(I-Pd) is applied to both ends of the core.
The coil element is manufactured by attaching electrodes to make internal electrodes, applying an exterior coating of magnetic powder to the coil body by pressure molding, and then firing this.

Conventionally, a square core rod 1-! was created by pressure molding or extrusion molding of magnetic powder. Or the coil body was created by winding it around a round core rod 2.

Figures 1 and 2 show the state in which the conductor wire 3 is wound around these.
This is shown in the figure.

A side view of these is shown in FIG.

When a conductor wire is wound around these magnetic bars 1 and 2, the following problems are considered to occur. That is, in the square core rod 1, when the wire is wound, the ferrite heat-resistant insulator and the resin, ie, the magnetic layer, separate from each other at the corner 1a, and the AIIJ-Pcl wire is exposed, and the conductor wire 3 is short-circuited when tightly wound. There is a danger that the conductor wire 3 may be cut at the corner where the magnetic layer comes off, and damage to the conductor wire 3 is likely to occur. On the other hand, although the round core rod 2 does not have the above problem, the conducting wire 3 tends to slip and it is difficult to make the magnetic path 3a for creating a closed magnetic path reliably and uniformly on the left and right sides, and there is a risk of increased magnetic flux leakage. be. Further, it is difficult to make the distance 3b constant, and it is difficult to adjust the inductance or obtain a constant inductance by making the number of turns the same. moreover,
In order to obtain high inductance, the best way to obtain high inductance is to tightly wind the conductor with multilayer windings since the length of the core is short. There is a risk of short circuit. In addition, both square wick 1 and fire wick 2 are multilayer wound (
In the case of three-layer winding (Fig. 4), as shown in Fig. 4, when the conductor wire 4 is pulled to create a magnetic path, the wire 5 at the end of the third layer collapses, causing the entire wire to loosen and the adhesion to deteriorate. There is a risk that the product may become distorted or become a distorted multi-layered roll.

Furthermore, as shown in Figure 6, the magnetic layer is peeled off from both ends of the cores 1 and 2 and the internal electrodes are dipped in Aq-Pd paste 6 to form internal electrodes. It is uneven and there is a risk of blocking the magnetic path.

Therefore, as shown in Figure 6,! One has been devised in which the edges and center of the t7 are shaved to form flanges 8 and 9. In this case, the conductor wire 1o can be wound between the flanges 8 and 9 as shown in FIG.
It is possible to prevent the internal electrode 11 from collapsing, and the adhesion position of the internal electrode 11 is restricted by the flanges 8 and 9, so that the end 1 of the conductor wire 10
The oaK internal electrode 11 is in contact with it.

However, since the flanges 8 and 9 are formed by cutting the winding core 7, the flanges 8 and 9 are prone to overhang, which poses an obstacle to mass production.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a method for manufacturing a Chi-nobu inductor that can mass-produce Chi-nobu inductors having a winding core provided with an incomplete flange.

Structure of the Invention In order to achieve the above object, the present invention provides flanges at both ends by wrapping a magnetic sheet having a width narrower than the length of the core body made of a magnetic material. The flange, which constitutes the winding core, is formed by obtaining a winding core element having a magnetic material, and then firing the winding core element and wrapping a magnetic sheet around the flange, which constitutes the winding core. In production, the occurrence of defective products is extremely rare.

DESCRIPTION OF EMBODIMENTS A method of manufacturing a Chi-nobu inductor according to an embodiment of the present invention will be described below with reference to the drawings.・In this embodiment, as shown in FIG. 8, a magnetic wire 13 whose width is narrower than the length of the winding core body 12 is attached to the winding core body 12 made of a magnetic material.
Wrap the required number of layers. The core body 12 is then cut to a required length and then fired to obtain the core 14 shown in FIG. 9. Then, the magnetic sheet 13 wound around the winding core body 12
A conductor wire 17 is wound between the flanges 15 and 16 of the winding core 14 formed by. Note that the end portion 17a of the conductor wire 17 is located outside the collar portion.

After that, internal electrodes 18 and 19 are provided at the ends of the winding core 14,
Finally, a magnetic ferrite 20 and an external electrode 21 are provided to complete the chip inductor shown in FIG.

Since the flange portions 15 and 16 are formed by winding the magnetic sheet 13, there is no chipping caused by scraping, which is convenient for mass production.

The winding core element 12 can be formed to the length required for one chip inductor and the magnetic sheet 13 can be wound around it, or the core body 12 can be formed to the length required for multiple chip inductors as shown in FIG. A required number of magnetic sheets 13 may be wound around the core body 12 and then cut.

Effects of the Invention As described above, the present invention forms a flange by wrapping a narrow magnetic sheet around a winding core body made of a magnetic material.
It is possible to mass-produce chip inductors that do not cause misalignment or deformation of the conductor wires without having to cover the flange.

[Brief explanation of drawings]

Figures 1 and 2 are perspective views of the inside of a conventional chip inductor, Figure 3 is a front view of the same, Figure 4 is a sectional view of the same essential parts, and Figure 5
The figure is a front view showing how internal electrodes are provided in the same chip inductor, Figure 6 is a perspective view of the winding core in another conventional chip inductor, Figure 7 is a sectional view of the main parts inside the same, and Figure 8 is the main part of this chip inductor. FIG. 9 is a process diagram showing a method for manufacturing a chip inductor according to an embodiment of the invention, FIG. 9 is a half-sectional view of the chip inductor manufactured by the same extravagant method, and FIG. 10 is a perspective view thereof. 12... Core element, 13... Magnetic sheet, 14... Winding core, 15.16...
Flange portion, 17... Conductor wire, 18... Internal electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person2 Figure 6 Figure 8 Figure 9 2θ Figure 1O Figure 2θ

Claims (1)

[Claims] By winding a magnetic sheet □ whose width is narrower than the length of the core element made of a magnetic material, a core element having flanges at both ends is obtained. is fired to form a winding core, two conductor wires are wound between the flanges of the winding core, and the ends of the conductor wires are positioned outside the flanges of the winding core, and then A method of manufacturing a chip inductor, comprising providing an electrode connected to the conductor wire at the end of the core.