JPS62283422A - Production of perpendicular magnetic recording medium - Google Patents

Abstract

PURPOSE:To manufacture a medium having durability by maintaining a sputtering pressure at <=2X10<-3>Torr at the time of producing a CoCr perpendicular magnetic recording medium by a sputtering method. CONSTITUTION:The result of a test by a scratching testing machine indicates that the strength of the CoCr film increases with a decrease in the sputtering pressure. The medium formed by sputtering under the pressure higher than 2-3X10<-3>Torr pressure as a boundary wears down and has the decreased output in a short period. The medium having the high durability is, therefore, obtd. by the sputtering under <=2X10<-3>Torr pressure.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method of manufacturing a perpendicular magnetic recording medium.

[Prior art and its problems]

Conventionally, a CoCr alloy film has been a promising material for realizing high-density magnetic recording using the perpendicular magnetic recording method. This alloy film is usually formed on a plastic carrier film mainly by vacuum evaporation and sputtering, and because the magnetic layer is a continuous body, a dramatic improvement in recording density is expected.

However, the magnetic layer manufactured in this manner has the disadvantage of poor durability.

In addition, if wear occurs in a part of the CoCr magnetic layer for some reason, this will trigger the wear to progress and cause a crash in a short period of time, creating a major barrier to practical application. Ta.

[Means for solving problems]

The present invention aims to eliminate these drawbacks by controlling the conditions for forming the CoCr film in the sputtering method.
The mechanical strength of the magnetic layer is increased. This makes it possible to obtain a perpendicular magnetic recording medium with practical durability.

Generally, thin films are created by sputtering.

Sputter pressure and substrate during sputtering (here:

It is known that the fine structure of the carrier film for holding the magnetic film changes depending on the temperature, and the mechanical properties change accordingly.

The present inventor paid attention to this point and evaluated the relationship between the sputtering pressure and the film strength of the CoCr film using a scratch tester, and found that there was a large correlation.

That is, as shown in FIG. 1, the film strength increases as the S/'Py pressure decreases.

Furthermore, we created a vertical medium in which only the sputtering pressure was changed,
When the driver was attached to a commercially available 3.5-inch driver and recorded and played back, the time required for the average output to reach 80% of the initial output, that is, the number of scratches, was measured by a professional, and as shown in Figure 2, spatter was observed. It can be seen that the lower the pressure, the more durable it is.

Furthermore, after the average output reaches the initial output of 80, 40
Figure 3 shows the time it takes to reach the goal.

It is noteworthy that the media that was stirred at pressures higher than 2 to 3 X 10 Torr wore out in a short period of time and the output decreased, whereas the media that were stirred at lower pressures It takes quite a long time for the output to decrease.

i.e. less than lXl0 -3 Torr, at least 2X1
It goes without saying that media that is exposed to pressures below 0-3 Torr is less prone to wear, and even if some wear occurs, it is unlikely to lead to a hesode crush over a long period of time. This not only improves the durability of the media, but also makes the head less likely to be damaged by abrasion particles from the media.

Embodiments of the present invention will be described below with reference to the drawings.

<Example 1> A CoCr film was deposited on a 50 μm polyimide film at 1.
It was made to a thickness of 0.3 μm at a pressure of 10 Torr.

Let this sample be A1.

Comparative Example 2> Under the same conditions as Example 1, only the suction pressure was 5 x 1 O-
It was created as 3 Torr. This sample is called ya2.

Samples 1 and 2 were attached to a commercially available 3.5-inch driver, and a non-square test was conducted.

FIG. 4 shows the changes in the average output of samples Boiled 1 and Boiled 2. It can be seen that the durability has clearly improved.

In addition, although the CoCr single-layer medium was described in the embodiment, the same effect can be obtained with respect to CoCr stains in a two-layer medium, and the present invention is not limited to the two embodiments.

Furthermore, in single-layer media and dual-layer media, similar effects can be obtained by adding a protective film and lubricant on the CoCr film, so the present invention is not limited to the seven examples.

In addition, in this embodiment, the RF magnetronometry was used to perform the S/E and the evening, but the RF snow? Ivy, DC's
Similar effects can be obtained using ivy r DC magnetron snow and ivy method odor, so the invention is not limited to these two embodiments.

〔Effect of the invention〕

As described above, according to the present invention, a perpendicular magnetic recording medium with practical durability can be obtained by setting the sputtering pressure of the CoCr film to 2X10 Torr or less, preferably 1X10 Torr or less in the Sun-Sunta method. Ta.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between sputtering pressure and film strength. FIG. 2 is a diagram showing the relationship between the pressure and the moss wear test, and shows the number of rotations (number of revolutions) required for the average output to drop to a factor of 80 of the initial output. FIG. 3 is a diagram showing the relationship between sputtering pressure and no wear test, and shows the number of rotations (*number of rotations) required for the average output to decrease from 80% to 40% of the initial output. FIG. 4 is a diagram showing output changes with respect to the magnetic recording medium according to the present invention and the conventional example. Figure 1 0.5 1 2345 10

Claims (1)

[Claims] 1. In the method of manufacturing a CoCr perpendicular magnetic recording medium by sputtering, the sputtering pressure is set to 2×10^-^3
1. A method for manufacturing a perpendicular magnetic recording medium, characterized in that the magnetic recording medium is made less than Torr.