JPS6117280A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent a magnetic disk from being damaged when starting a rotation of the magnetic disk by forming a slider surface of a magnetic head to a rough surface, so that an attraction of the slider surface of the magnetic head and the magnetic disk is not generated, even if the time when the magnetic disk does not rotate becomes long. CONSTITUTION:A slider surface of a magnetic head is usually finished to a specular surface, but in this case, on the contrary, it is formed to a rough surface. It is difficult to execute etching of the slider surface using hard carbon, by means of a chemical treatment, therefore, the slider surface is formed to a rough surface by executing an ion etching under a mixed atmosphere of argon and oxygen or an oxygen atmosphere. The etching conditions are to use a Kaufmann type 4-inch caliber gun, an accelerating voltage 1kV, a beam current density 1.2mA/cm<2>, and Ar 8X10<-5>Torr+O2 8X10<-5>Torr. In this way, the slider surface of the magnetic head can be formed to a rough surface until the magnetic disk and the slider surface of the magnetic head do not cause an attraction.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a magnetic head for a contact start/stop type magnetic disk or a contact running type magnetic disk. This is what I did.

[Prior art]

Conventionally, the material for the slider surface of a magnetic head was Ni.
ZH ferrite, Mn ZH ferrite, A11I0
3-TiC sintered products or hard carbon (glassy carbon) have been used, and these have been mirror-finished and put into practical use.However, as devices become more densely recorded, the height at which the magnetic head flies above the magnetic disk has decreased. As the diameter has become smaller than 0.3 μm, there are many opportunities for the flying stability of the magnetic head to be impaired when disturbances occur, or for the slider surface of the magnetic head to come into contact with the magnetic disk surface during contact start/stop operations. In this case, if the slider surface is made of a material with a large coefficient of friction or a material whose hardness is significantly greater than that of the magnetic disk, there is a possibility that the magnetic disk surface will wear out or a head crash will occur.

For example, ferrite has a moderate hardness but a large friction coefficient, and ATOs-TiC sintered material has a moderate friction coefficient but has a large hardness, so neither of them is suitable as a material for the slider surface. On the other hand, hard carbon has moderate values for both hardness and coefficient of friction, making it suitable as a material for the slider surface. Conventionally, hard carbon was used for the slider surface and mirror-finished material was used. It was getting worse.

However, since the magnetic disk surface is also finished smooth, in such conventional magnetic heads, when the magnetic disk is not rotating for a long time, adhesion occurs between the magnetic disk surface and the slider surface of the magnetic head. The coefficient of friction increases. By applying an appropriate amount of liquid lubricant to the disk medium surface, as shown in the characteristic of symbol 1 in Fig. 1,
The coefficient of friction can be reduced. However, the amount of lubricant that is generally used is much larger than the amount that gives the lowest friction coefficient, so in this case, the lubricant causes adsorption, which actually increases the friction coefficient. . When a magnetic disk and a magnetic head are attracted to each other, the magnetic disk begins to rotate with the magnetic head attached to it, but since the magnetic head is supported by a spring in the drive system, the elasticity of the spring has a large effect on the attraction force. Since the magnetic head is separated from the magnetic disk at nine o'clock and pulled back by the elasticity of the spring, the surface of the magnetic disk may be damaged when it collides with the magnetic disk due to its inertia.

[Object and structure of the invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic head that prevents the magnetic disk from adhering to the slider surface of the magnetic head.

In order to achieve this object, the present invention roughens the surface of the slider surface of the magnetic head until the magnetic disk and the slider surface of the magnetic head no longer attract each other. The present invention will be described in detail below.0 [Example] The surface of a magnetic herad slider is usually mirror-finished, but in this invention, it was roughened. Since etching of the slider surface using hard carbon is difficult by chemical treatment, the surface of the slider was roughened by ion etching in a mixed atmosphere of argon and oxygen or in an oxygen atmosphere.

Motzing conditions were as follows: Kaufmann type 4-inch diameter gun, acceleration voltage IKV, beam current density 1.2 mA/a.
d, Ar8X10 Torr+028X10T
It was orr. FIG. 2(b) shows the roughness curve of the hard carbon slider surface after etching for 1 hour under the above conditions, and FIG. 2(e) shows the roughness curve of the slider surface after etching for 3 hours. Moreover, (a) is a roughness curve in the case of mirror finishing only. From each roughness curve, the maximum height Rmax is 0:01 μm or less in (,) and 0.01 μm in (b).
03 firth, (c) is 0.04 μm.

The friction coefficients of the magnetic herad slider with the surface roughness corresponding to (b) and (e) in FIG. 2 are shown by symbols 2 and 3 in FIG. 1, respectively. In this way, the coefficient of friction of the magnetic head of a hard carbon slider is significantly reduced by roughening its surface by ion beam etching, and does not change depending on the amount of liquid lubricant on the magnetic disk surface. . Here, the maximum height Rma where the effect of surface roughening on adsorption appears
The lower limit of x varies depending on the amount of lubricant applied, but Rmax
Since the friction coefficient gradually begins to decrease at 0.01 μm or more, it can be said that the friction coefficient is 0.01 μm or more. Also Rm
It has been confirmed that the upper limit of ax does not affect the flying characteristics even if it is equal to the flying clearance of the head as long as the unevenness is uniformly processed. Therefore, if the slider surface is roughened until the disk medium and the magnetic head slider surface no longer attract each other in an environment with humidity of 60% and room temperature within this range, the coefficient of friction will be small regardless of the environmental conditions. No adsorption occurs.

In addition, Rmax was reduced to 0.03 using SSO with a lubricant application amount of 5, a protective film plated disk, and ion beam etching.
When a contact start/stop test was attempted using a magnetic head (load: 6 gf) with a hard carbon slider of μm diameter, there was no damage to the head medium even after 20,000 tests, and there was no damage to the head or medium due to the hard carbon slider and the roughness of the rider surface. The curve did not change much compared to before the test.

Although an example of surface roughening by ion beam etching has been described here, similar surface roughening processing is also possible by ion etching such as parallel plate plasma etching.

〔Effect of the invention〕

As explained above, in this invention, the slider surface of the magnetic head is roughened, so even if the magnetic disk does not rotate for a long time, the slider surface of the magnetic head and the magnetic disk will stick to each other. This has the effect of not damaging the magnetic disk when it starts rotating.

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between the amount of lubricant applied and the coefficient of friction.
FIG. 2 is a graph showing the roughness of the slider surface depending on etching conditions.

Claims (1)

[Claims] To record and reproduce data on magnetic disks,
A magnetic head using hard carbon for the slider surface, which has a slider surface that has been roughened to the point where the magnetic disk and the slider surface of the magnetic head no longer attract each other when the magnetic disk starts rotating.