JPS5866625A - Finishing method of magnetic head floating surface - Google Patents

Abstract

PURPOSE:To decrease adsorptive force caused between a magnetic head and disc, by finishing a floating surface of a magnetic head by abrasive work, further it through dry etching and roughing said surface. CONSTITUTION:A head floating surface in a ferrite core of Mn, Zn of a magnetic head, used for a magnetic disk device, is polished by abrasive work to 0.01mum in surface roughness. This floating surface is applied with ion etching of the plasma etching and the like for a time from several minutes to ten-odd minutes, and roughed to about 0.03mum in surface roughness, then the magnetic head is prepared. In this process, friction force between the magnetic head and disc, and absorptive force caused by interposition of oil and water can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for finishing a flying surface of a magnetic head used in a magnetic storage device such as a magnetic disk device or a magnetic drum device.

High W of high-density magnetic disk device? In order to measure the degree of
It is necessary to reduce the distance between the magnetic head and the magnetic disk (referred to as "lower spacing").

In recent years, contact starting and
The surface roughness of the floating surface of the magnetic head (hereinafter referred to as head) and the surface of the magnetic disk (hereinafter referred to as disk) used therein is 10 to 100A by polishing. It is a small degree of f+fi.

For this reason, if the head remains in contact with the disk surface for a long period of time, the head and disk will come into close contact with each other, and the motor that rotates the disk may become unable to rotate, or in severe cases, the head support spring may be damaged. arise. (Hereinafter, this phenomenon will be referred to as head adsorption.) Head adsorption is particularly noticeable when an adsorption layer of oil, water, etc. exists at the interface between the head and the disk.

The frictional force that acts between the disk and the head when they are sliding is also a major factor in the reliability of a contact start/stop type magnetic disk device.

That is, the smaller the frictional force, the less mechanical load is applied to the head or the disk when the head and disk are sliding in contact with each other, and scratches are less likely to occur.

The force (head adsorption force) exerted between the head disk by the above-mentioned head suction pair is not a frictional force in general. Head attraction force is the force that acts when smooth surfaces come into contact with each other, and is proportional to the area of the contact surfaces, but frictional force is not related to the area of the contact surfaces. The force moving between the head and the disk is the head adsorption force and the friction force. However, if the contact between the head and the disk is for a short time (seconds), the head adsorption force can be nullified, so the friction force (If divided by the load, it is expressed as static friction coefficient and dynamic friction coefficient), and when the contact is for a long time (on the order of days), it is expressed as head adsorption force.

An object of the present invention is to provide a method for finishing the flying surface of a magnetic head, which reduces head adsorption and Sjl force as described above in combination with a magnetic disk having a small surface roughness, thereby producing a highly reliable magnetic head. It's about r.

A magnetic head according to the present invention? ! The finishing method for the floating surface is characterized by etching the flying surface of the magnetic head which has been polished by dry etching to make the surface rough.

The dry etching referred to here is an ion etching method.
Alternatively, a plasma etching method or a reactive deep ion etching method may be used. The dry etching method makes it possible to soften the flying surface of the head and prevent head adsorption without damaging the bed gap, that is, without impairing the electromagnetic characteristics of the head. This is a feature not seen in etching using chemicals such as acids and bases.

Furthermore, since the head core has a smaller shape than the disk, even if a dry etching method using a vacuum system is used, it has very little effect on mass productivity.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Mn7. After polishing the head floating surface of the n-ferrite core to a surface roughness of 0.01 μm, ion etching was performed (305) to roughen the surface to 0.03 μm, and a support spring and coil were attached to fabricate a magnetic head. The coefficient and head adsorption force were evaluated.

Example 2 Ion etching was carried out in the same manner as in Example 1, except that ion etching was carried out for 2 minutes, 6 minutes, 8 minutes, 12 minutes, and 18 minutes, and the magnetic heads were set to 1, B, C2D, and E, respectively.

Implementation row 3 Same as Example 1, except that plasma etching was used instead of ion etching, and the surface roughness was reduced to 0.03 μmK.
A magnetic head was manufactured using m<.

Example 4 Same as Example 1 except that reactive ion etching was used instead of ion etching to reduce the surface roughness to 0.
A magnetic head was manufactured by roughening it to 0.04 μm.

Example 5 A magnetic head was manufactured in the same manner as in Example 1, except that a NiZn 7 erite core was used instead of the MnZn ferrite core.

Using the heads shown in Examples 11 to 5 above, the maximum static friction coefficient, average dynamic friction coefficient, and stick-slip 1 were measured, and the results were as shown in the table below.

Here, the maximum static friction coefficient, average friction coefficient, and stick-slip amount are defined as follows.

Maximum static friction coefficient: The value obtained by dividing the force applied to the head immediately after the disk starts rotating by the head load, and has a positive correlation with the head suction amount.

Average dynamic friction coefficient: The value obtained by dividing the average value of the force applied to the head by the head load when the disk is sliding against the head at 0.5 m/sec. The stick-slip amount is 0 for the disc.
．． It is the difference between the maximum value and the minimum value of the force applied to the head when the head slides at 5 wa/see, and is an amount that has a positive correlation with the head adsorption.

As described above, it can be seen that the heads whose floating surfaces were etched by dry etching as shown in Examples 1 to 5 had each value significantly reduced compared to the heads that were not dry etched.

Furthermore, when the head and disk are left in contact for 139 hours at a humidity of 50 degrees and a temperature of 25-0 degrees, the adsorption force acting on the head and disk is 1 of that of a non-dry etching head.
Compared to No. 02, all of the dry-etched heads shown in Examples 1 to 5 were 2.5 f or less. As described above, it has been found that the method of etching the floating surface by dry etching can greatly reduce the force acting between the head and disk, thereby making it possible to manufacture a highly reliable magnetic disk drive.

Claims (4)

[Claims] (1) A method for finishing a flying surface of a magnetic head, which comprises etching the polished flying surface of a magnetic head by dry etching. (2) A method for finishing a magnetic head flying surface according to claim 1, wherein the dry etching is an ion etching method. (3) A method for finishing a magnetic head flying surface according to claim 1, wherein the dry etching is a plasma etching method. (4) A method for finishing a magnetic head flying surface according to claim 1, wherein the dry etching is a reactive ion etching method.