JPS60106023A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a base plate for a magnetic recording medium having a high characteristic by coating silanol on the base body and subjecting the base body to a heat treatment to vitrify the silanol and polishing further the glass to a specular surface. CONSTITUTION:It is difficult to make the thickness of silanol <=0.5mum in terms of a polishing technique and is difficult to make the same >=10mum in terms of coating. The thickness of the silanol by one time of coating at the present is 4,000Angstrom at the most. A glass film having several mum - several mum thickness is thereupon formed by repeating many times silanol coating and heat treatment and thereafter the film is polished and further a magnetic film is stuck thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic recording medium, particularly a recording medium for a rigid disk device.

[Background of the invention]

Conventionally, At substrates have been mainly used as substrates for rigid disks. The At substrate is Fe.

Contains many impurities such as MnmSi. When a magnetic film is deposited on an A7 substrate by sputtering or the like, defects occur due to the reaction between the impurities and At. One of the methods to reduce this defect is to anodize the At substrate surface.
There is a method in which an Os film is produced and then partially polished to form a substrate. However, even with this method, it is difficult to obtain an ideal substrate surface. Actually 3 μm AtzO
Error rate of Co-Cr film fabricated on S film is 112io"'
Met.

(Linear recording density 100kBPI) Rack retention 600TPI
(floating spacing: 0.05 μm) [Object of the Invention] An object of the present invention is to reduce the defects of the aforementioned rigid disk substrate and to provide a recording medium suitable for high-density recording.

[Summary of the invention]

The present inventors have discovered that a substrate for a magnetic recording medium with high characteristics can be obtained by applying silanol to a substrate, vitrifying the silanol by heat treatment, and then mirror-polishing the glass.

It is difficult to reduce the thickness of silanol to 0.5 μm or less from the standpoint of polishing technology, and it is difficult to increase the thickness to 10 μm or more from the viewpoint of coating. At present, the thickness of silanol with one application is at most 4000. Therefore, in practice, a glass film with a thickness of several micrometers to several tens of microns is formed by repeating silanol coating and heat treatment many times, and then this is polished and a magnetic film is activated on top of it for magnetic recording. Use as a medium.

[Embodiments of the invention]

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

Example 1 550C after coating silanol on stainless steel substrate
, and heat treatment for 1 hour, and further repeat this silanol application and heat treatment 20 times to produce a glass film with a thickness of 8 μm. Next, this glass film is polished to a thickness of 3 μm to provide a substrate for a magnetic recording medium.

A 0.7 μm thick Co-
A Zr--Mo film and a 0.3-μm-thick CO-Cr film are fabricated by sputtering, and these are used as magnetic recording media.

〔Effect of the invention〕

Using this magnetic recording medium and perpendicular magnetic recording head,
0kBPI, 600TPI, floating spacing 0.05
When we conducted a μm recording and reproducing experiment, the error rate was 10'
-11.

Example 2.3 Instead of the stainless steel substrate used in Example 1, a copper substrate,
The error rate when using At203/Ti-C substrate is also 10
-I failed at 11. This value is At/At20 mentioned earlier.
It can be seen that this is significantly improved compared to the value of 10-6 when using the a-substrate.

As described above, it has been revealed that according to the present invention, a magnetic recording medium with a low error rate can be manufactured.

Agent: Patent Attorney Akio Takahashi

Claims (1)

[Claims] 1. A magnetic recording medium characterized in that silanol is coated on a metal or ceramic substrate, heat treated to vitrify the silanol, the surface is polished, and a magnetic film is further attached.