JPS582780B2 - Ferrite Cage Seizairiyoumoshikuha - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for finishing the surface of a ferrite magnetic material or a composite material containing a ferrite magnetic material.

Finishing that gives the surface of a workpiece made of a ferrite-based magnetic material or a composite material containing a ferrite-based magnetic material a bell-shaped surface, which is conventionally used in the recording/reproducing core of magnetic heads for electronic computers, magnetic heads for audio, etc. Methods include rappig and polishing methods.

In the lapping or polishing method, the roughness of the machined surface of the workpiece can be reduced to 0.0 by selecting lapping abrasive grains of appropriate particle size, lapping liquid, and lapping surface plate.
2-0.03μmRmax, machining flatness 0.1-0
．． It can be finished to 2 μm/mm.

However, when ferrite-based magnetic materials are finished by wrapping or polishing, a layer different from the inside, a so-called process-affected layer, is formed on the surface due to the force acting on the processed surface or the heat generated during processing. .

In the case of the above processing method, the thickness of the process-affected layer reaches 0.2 to several μm, which causes deterioration in the performance of the magnetic head.

Methods for removing this process-affected layer include an etching method and a mechanochemical polishing method.

The etching method is a method in which the surface of the workpiece is polished to a mirror finish by wrapping or polishing, and then immersed in a strong acid solution such as hydrochloric acid, hydrofluoric acid, or phosphoric acid. There are scratches and cracks introduced during the polishing process, and the process progresses quickly in some areas, which has the disadvantage of making the finished surface uneven, and the surface roughness after polishing is 0.2
It deteriorates to ~1 μmRmax.

Furthermore, the flatness of the peripheral portion of the mirror surface of the workpiece deteriorates due to the occurrence of machining sag, so this method cannot be used as a final finishing method for a magnetic head.

In addition, the mechanochemical polishing method is a processing method in which the workpiece is polished on tanned leather, cloth, or an elastic grindstone using a mixture of lap abrasive grains and chemical liquid, and it is possible to reduce the process-affected layer. However, it has the disadvantage that it takes a long time to process and the degree of flatness deteriorates.

The present invention is intended to eliminate the above-mentioned drawbacks, and consists of forming a metal thin film layer on the side surface of a ferrite-based magnetic material for processing, forming a workpiece, and combining it with at least one type of mechanically acting fine powder. A mixture of at least one type of chemical liquid that acts chemically is interposed between the lapping plate and the surface of the workpiece to be surface-finished, and the workpiece is placed on the lapping platen under a predetermined pressure. The surface is finished by rotation or sliding motion on the top.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, the principle of processing ferrite-based magnetic materials will be described with reference to FIG.

A chemical liquid 3 is placed in a container 5.

The workpiece 1 and the metal electrode 2 are immersed in a chemical liquid 3 and are connected to each other by a conductive wire 4.

In this groove formation, the metal electrode 2 M→M+++2e−…(1) reaction occurs.

At this time, a reaction occurs regarding Fe203, which is the main component of the ferrite magnetic material of the workpiece 1.

As a result, electrons generated when the metal electrode 2 melts flow to the workpiece 1 through the conductive wire 4, and the melting of the workpiece 1 is promoted.

In this processing method, as described above, an internal battery is formed by the chemical liquid 3, the workpiece 1, the metal electrode 2, and the conductive wire 4.

FIG. 2a shows a state in which a metal thin film 7 is formed by an amount of machining allowance a on both sides of a surface perpendicular to the surface F to be processed of the ferrite-based magnetic material 6 by a vapor deposition method, a sputtering method, or the like.

FIG. 2b schematically shows the workpiece 10, which has a structure in which an insulating material 9 and a ferrite-based high-temperature material 6 on which a metal thin film 7 is formed are joined by an adhesive 8.

FIG. 3 shows one embodiment of the present invention, which is constructed as follows.

The lap surface plate 11 is configured to rotate in the direction of arrow X.

As described above, the workpiece 10 on which the metal thin film is formed is held by the holding plate 13 via the spring 12.

A load 14 is forcefully applied to the holding plate 13 via a load rod 15.

A moving body 16 that moves in the direction of arrow Y is connected to the load rod 15, and the movement is transmitted to the workpiece 10 via the load rod 15, the holding plate 13, and the spring 12, so that the workpiece 10 moves. Move in the direction of arrow Y.

A chemical liquid 1 is contained in a tank 17 equipped with a stirring device 18.
9 and abrasive grains 20 are placed therein, and both are supplied onto the lapping surface plate 1-1 via a pot 21.

In this configuration, the chemical liquid 19 and the abrasive grains 20 are supplied while the lapping surface plate 11 is rotated in the direction of the arrow X and the workpiece 10 is slid in the direction of the arrow Y.
To perform the finishing, mechanical processing using abrasive grains 20 and electrochemical processing due to the formation of an internal battery between the ferrite-based magnetic material in the workpiece 10, the metal thin film, and the chemical liquid 19 proceed.

Therefore, finishing of the workpiece 10 is completed quickly.

An example of this method is shown below.

Mn-Zn ferrite as a workpiece, copper thin film,
When a composite material consisting of a ceramic material as an insulating material and an adhesive is processed by a predetermined amount using a tin lap platen, diamond powder, and a hydrochloric acid solution, Mn-
The surface roughness of Zn-based ferrite is 0.03μmRmax
can be obtained, and Mn-Z can be obtained for ceramic materials.
N-ferrite can be processed to an extra 0.2μm,
Furthermore, as a result of measuring the process-affected layer of the Mn-Zn-based ferrite material using electron beam diffraction, it was found that the process-affected layer was reduced compared to conventional processing methods.

In the above embodiment, diamond powder was used as the lap abrasive grain, but alumina powder, carborundum, or other abrasive grains may also be used.

Although a hydrochloric acid solution was used as the chemical solution, other electrolyte solutions may be used.

Further, although copper is used as the metal thin film, the present invention is not limited to copper, and other conductive materials that dissolve in a chemical solution and emit electrons may be used.

As explained above, as shown in Table 1 below, the present invention has the advantage of forcibly forming an internal battery consisting of a ferrite-based magnetic material, a metal thin film, and an electrolyte solution, compared to the prior art. It is possible to promote electrochemical processing, improve processing efficiency of ferrite-based magnetic materials, and reduce processing-affected layers.

It also has the effect of being able to check the amount of processing based on the presence or absence of the metal thin film layer.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the processing principle of ferrite magnetic material, Fig. 2 is an explanatory diagram showing the outline of the workpiece. FIG. 3 is an explanatory diagram showing one embodiment of the present invention. 6... Ferrite magnetic material, 7... Metal thin film, 8... Adhesive, 9... Insulating material, 10... Workpiece, 11... Wrap surface plate, 12... Spring, 13... Holding plate, 14... Load, 15... Load rod, 16... Moving body, 17... Tank, 18... Stirring device, 1
9...Chemical liquid, 20...Abrasive grain.

Claims (1)

[Claims] 1. When processing a ferrite-based magnetic material or a composite material containing a ferrite-based magnetic material, a metal thin film layer for processing is formed around the material, and at least one type of fine powder and at least one type of electrolyte solution are supplied to this. A method for finishing a ferrite-based magnetic material or a composite material containing a ferrite-based magnetic material, which is characterized by finishing the material by rotating or sliding it on a fixed surface plate under a predetermined pressure.