JPS61162823A - Production of magnetic disk - Google Patents

Abstract

PURPOSE:To improve the reliability owing to an increase in the number of contact start stop CSS by using the decomposed polymn. product of ammonium silicate to form an SiO2 film on a magnetic metallic oxide recording medium. CONSTITUTION:After a sputtered gamma-Fe2O3 film is formed on a disk-shaped alumi num alloy substrate, about 10% ammonium silicate soln. is coated thereon by a spin coating method. Such circular disk is heat-treated at 300 deg.C in an electric furnace. The formation of the SiO2 film by the low-temp. heat treatment is made possible n the above-mentioned manner, by which the number of CSS is increased and the trouble by a head crash is decreased. The cost reduction is made possible by using an inexpensive raw material and the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic disk used in a magnetic disk device.

[Conventional technology]

An example of the structure of a magnetic disk using r-Fe20st- as a metal oxide magnetic recording medium is shown in FIG. Figure 2 shows, for example, P and 1 of Electric Corporation Research and Practical Application Report Vol. 31 No. 9.
731-1144, which shows the 11'r surface of the magnetic disk manufactured by the conventional method, as shown in Fig. 3 (
1) is a disk-shaped aluminum alloy base material.

(2) is an underlayer of a magnetic ML recording medium made of alumite.

(3) is the r Fe2O3 thin film that becomes the magnetic recording medium, (4
Reference numeral 1 denotes a lubricating layer that prevents the plate layers of the magnetic head and the magnetic disk from interfering with each other.

Currently, magnetic disk drives employ a contact start/stop method for starting and stopping, and during starting and stopping, the magnetic head and the surface of the magnetic disk rotate while being in contact with each other. The frictional force generated between the magnetic head and the magnetic disk in this contact friction state wears out the magnetic head 2 and the magnetic disk surface, and may eventually cause scratches on the magnetic head and the magnetic medium thin film.

One method for reducing this contact friction force is to provide a lubricating layer. Conventionally, it was believed that the coupling between the magnetic medium and the slip layer of metal oxide magnetic media was sufficiently strong;
Unlike the case of metal magnetic media, as shown in FIG. 2, a lubricating layer (I/Cg) was created without providing an underlayer between the lubricating layer and the magnetic medium.

[Problem that the invention seeks to solve]

Magnetic disks produced by conventional manufacturing methods are constructed as described above, but gold-megabaride magnetic recording media have good surface density (and are difficult to chemically adsorb).

There were problems such as scratches on the magnetic recording medium 9 and when a lubricant layer was provided, the lubricant layer was likely to peel off.

One solution to this problem is to coat metal oxide magnetic recording media with a silane coupling agent such as tetrahydroxysilane and a gold coating method such as metal alkoxide. A polysilicate film, which is a condensation polymer, is formed by overturning and heat-treating. However, heat treatment (approximately 400°C) that does not alter the characteristics of the magnetic medium
) and below), these raw materials are considerably inferior in hardness and strength compared to the glass-formed 5102 film, which can only be made into a polysilicate film as described above. For example, *In the Zol-Gul method of synthesizing karas from metal alkoxides, which has been recently studied, the heat treatment temperature required to hydrolyze metal alkoxides and turn them into karass is 600-100℃.
It is said that silica glass produced by the melting method exhibits the same properties when heat treated at 900 to 1000°C.
, Uchida Ro-ji (19113), 147-164 Sadan, 4
In heat treatment at temperatures below 00°C, no glass formation can be expected.

Namely.

Even if the polysilicon film was coated by the above method, it could not provide an essential solution.

In this way, the surface of a magnetic recording medium may be scratched or the slip layer may peel off due to various reasons.

A problem has arisen in that the contact start/stop (aSS) count, which indicates the reliability of the magnetic disk, decreases. Generally (if the cssBgl number is small.

Head crush is more likely (and therefore the survival rate is 131% higher).

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a reliable method for manufacturing a magnetic disk that increases the number of contact start-stop (aSS) operations.

[Means for solving problems]

The method for manufacturing a magnetic disk of the present invention involves decomposing ammonium silicate using an 8102 film on a metal oxide magnetic recording medium! It is made of 1f1- material.

[Effect]

The 5102 membrane made of a decomposed polymer of ammonium silicate according to the present invention can be manufactured from inexpensive raw materials. Because it changes to 8102 film by low-temperature heat treatment.

It plays a lubricating and protective role, and also serves as a strong base layer when a lubricating layer is provided, and has a strong sealing force with the lubricating layer, so it is easy to peel off the lubricating layer! Prevent ll.

〔Example〕

The ammonium silicate used here does not exist as a commercially available reagent, or can be easily synthesized by the method for producing ammonium silicate in the prior art (Japanese Patent Application No. 8611, No. 4729).

The raw material is sodium silicate, etc., which is very cheap compared to metal alkoxides and silane coupling agents.

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) is an aluminum association base material.

(2) is the base tm, t3) is the metal oxide magnetic recording medium, (4) is the lubricating layer, and (5) is the 5102 film.

Example R l”820 on a disk-shaped aluminum base metal base material
! After forming the S sputtering film, an approximately 10% ammonium silicate solution was applied by spin coating (rotation tX 2 G Orpm).
It was coated to a film thickness of 500λ.

This disc-shaped disc was heat treated in an electric furnace at a temperature of t-300°C for 3 hours. According to the x-ray diffraction diagram of this film, 2θ=5
,. No notable small-angle scattering was observed below.

It was found that the 8102 film had a structure similar to that of silica glass. On this 8102 film, a lubricating layer such as PIDAX (part name, DuPont M) or Talitex (trade name, manufactured by DuPont), in this case PIDAX, was formed.

The magnetic disk obtained as described above has reduced peeling of the slip layer, and the number of aSSs in the 0-day S test is about twice that of magnetic disks made using the conventional method. In addition,@
Similarly, when no slip layer was provided, the number of aSS was approximately doubled.

Further, in the above embodiments, a spin coating method has been described, but other methods such as a dipping method may also be used (although the same effects as those obtained in the above embodiments can be obtained).

Furthermore, as another metal oxide magnetic recording medium, cro2
In this case as well, the same effects as those of the above embodiments can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, since the 5102 film is formed of a decomposed polymer of ammonium silicate on the metal oxide magnetic recording medium provided on the base material, the 5102 film can be formed by low-temperature heat treatment. Can be formed.

This has the effect of increasing the number of 088 times, reducing failures due to head crashes, reducing costs by using inexpensive lk raw materials, and providing a highly reliable magnetic disk manufacturing method.

[Brief explanation of drawings]

FIG. 41 is a VFR diagram showing a magnetic disk obtained by an embodiment of the present invention, and FIG. 2 is a sectional view of a magnetic disk produced by a conventional manufacturing method. In Figure 8, (I) is an aluminum alloy base material, (2) is an underlayer, and (3) is a metal oxide magnetic recording medium (r-Fe2
0s). (4) L lubricating layer, (5) is 8102 film. In Figure 1, the same symbols indicate the same parts, and the same numbers indicate the corresponding parts. Agent Oiwa 3III Shi'! El Figure 1: Furumiram Rei 1 Shi 1 Material 2 2 Lower layer 3: Ruo oxidation 11 m Signs of catfish 4: Pickling layer 5: St (hN 2nd tel Procedural amendment (voluntary) Dear Commissioner of the Japan Patent Office!1031 , Case.Indication Japanese Patent Application No. 80-002902 No. 2, Name of the invention Method for manufacturing magnetic disks 3, Relationship with the case of the person making the amendment Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (ω1) ) Mitsubishi Electric Corporation Representative 1 Agent Moriya Shiki Address 2-2-3-6 Marunouchi, Chiyoda-ku, Tokyo Contents of the amendment (1) Details page 11, line 13, line 5, page 1, line 20.几[r-Fe
205J is corrected to [γ-Feze5J. (2) “!I? Gansho ARK” on page 5, lines 9 and 10
6611 to APG No. 4729” to “Patent Application No. 58-221
124 specification tatami, Japanese Patent Application No. 59-'192972.'' (3) Figure 1 of the drawings will be corrected as shown in the attached sheet. 7. Inventory drawing of the sakitsuke honjo (Fig. 1) 1 or more copies 1 Fig. 1 Nialuminum 4' Drinking Neo-2 2 Underlayer 3: Metal 6 Snoring - Noting the short side %L 1 book 4: Me 5 snow layer S: 5iOzQ branch

Claims (1)

[Claims] SiO_
1. A method for manufacturing a magnetic disk, characterized in that two films are formed of a decomposed polymer of ammonium silicate.