JPS6289216A - Magnetic storage body - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of a protective film by forming a thin film consisting of at least >=1 kinds of materials selected from an oxide, nitride, carbide, and carbon and further coating a thin high-polymer film having an imide group on the surface of the thin film. CONSTITUTION:The thin film consisting of at least >=1 kinds of materials selected from the oxide, nitride, carbide, and carbon is formed on a metallic medium and further the thin high-polymer film having the imide group entirely different in properties from the thin film is coated thereon. The protective film is thereby laminated by which the generation of defect is decreased and the metallic medium is protected against corrosive environment such as water. On the other hand, the high-hardness film is formed on the under layer of the thin high-polymer film having the imide group, by which the mechanical reliability between the thin high-polymer film and the head is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic storage body (hereinafter referred to as a storage body) used in a magnetic recording device (magnetic disk device, magnetic drum device, magnetic tape device, etc.). Specifically, the present invention relates to a protective film on a metal magnetic thin film medium (hereinafter referred to as metal medium) of a storage body.

[Summary of the invention]

The present invention provides a memory body in which a metal medium is coated with a thin film made of at least one substance selected from oxides, nitrides, carbides, and carbon, and the surface of the memory body is further provided with a polymer having at least an imide group. By coating with a molecular thin film, a memory body and a recording/reproducing head (hereinafter referred to as a head) can be created.
At the same time, by significantly lowering the coefficient of friction between metal media, the mechanical reliability of the memory medium is increased, and at the same time, the anti-corrosion effect is dramatically improved by laminating inorganic and organic films with different properties on the metal medium. It is something that

[Prior art]

In a storage medium having a metal medium, it is essential to coat the storage medium with a protective film having sufficient mechanical reliability to withstand contact with the head and corrosion resistance to protect the metal medium from abrasion.

Conventionally, Rh, C! Covering with a metal layer such as r, N1-P, Au, etc. as a protective film is disclosed in Japanese Patent Publications No. 47-49603 and No. 4
B-14241, 4B-418, 81, 55-62
57. This has been proposed in JP-A-53-73J08 and JP-A-5B-26520, etc., but in order to ensure sufficient corrosion resistance of the memory body, the thickness of the metal layer must be 1oooK or more, and the mechanical reliability is This is extremely low. Mata Tokko Sho 4
9-29445, 52-17402. 5B-576
16. Formation of an oxide layer by both wet and dry surface treatment methods has been proposed in JP-A-57-117126, etc., but these surface treatment methods change the magnetic properties of the metal magnetic thin film medium and cannot be obtained. The mechanical reliability and corrosion resistance of the magnetic memory were also insufficient. Also, Special Publication Showa 49-26565. 50-5
0445. 51-15967, 52-18001.
54-29242. 54-34602. 55-2
9500, 57-40565. 57-58731,
58-57614. 5B-37615, Japanese Unexamined Patent Application Publication No. 1973
-47401. 51-1484061 55-108
930. Same 57-1471! +3, 57-18933
9. Oxide films such as No. 58-155654 and No. 5B-108030, and Japanese Patent Publication No. 55-59047. Unexamined Japanese Patent Publication 1973
-75931, 58-179938. 58-179
939, 58-179940, etc., have poor lubricity, and in order to ensure corrosion resistance, 1000
I had to make the film thicker than ＾thick.

Furthermore, it was difficult for the anticorrosive agent such as dihydric phenol disclosed in JP-A-57-152517 to maintain its initial anticorrosive effect over a long period of time. On the other hand, as a lubricating film,
l, JP-A-53-1432[)6, JP-A-56-4j524
Although the carbonaceous film shown in Fig. 1 shows superior lubricity compared to other protective films and improves the mechanical reliability of the memory element, repeated contact between the head and the memory element causes damage to the head and the memory element.
The coefficient of static friction with the body increases and eventually the rotating spindle motor of the storage body stops. A so-called ringing phenomenon occurred, many pinholes were formed, and there was no anti-corrosion effect. Also Surface Chemistry Vol. 5 No. 4 (1984) P78-P84
and JP-A No. 59-168952, No. 59-171.02
6. No. 59-171027, there is a publication on a polyimide coating formed by sputtering, but although this has a low coefficient of friction with the head, its long-term mechanical reliability and anti-corrosion effects are still insufficient.

[Problem that the invention seeks to solve]

As described above, the prior art has the problems of physical deterioration and ringing phenomenon of the storage body and head due to contact between the storage body and head, and failure to ensure sufficient corrosion resistance of the metal medium of the storage body.

Therefore, the present invention is intended to solve these problems, and its purpose is to treat oxides and nitrides.

The purpose of the present invention is to provide a storage medium having a metal medium that improves the corrosion resistance of a thin protective film made of at least one substance selected from carbide and carbon, improves the coefficient of friction with the head, and has excellent long-term reliability. .

[Means for solving problems]

In the storage body of the present invention, after forming a metal medium on a base, O
Forming a thin film made of at least one substance selected from oxides, nitrides, carbides, and carbon, with or without forming a film made of at least one substance selected from r, Ti, Ta, and Wb; A further feature is that the surface of the thin film is coated with a polymer thin film having at least an imide group.

Or, Ti, Ta, and Nb are coated for the purpose of ensuring the adhesion between the metal medium and oxides, nitrides, carbides, and carbon, and a film thickness of 50 to 200 mm is sufficient.

The oxides are S i O□, T i 02 , Or
203 etc., nitrides are TiN, Ta2N, AtN
, Si, N4, etc. The carbide may be SiO, TiO, etc. Carbon may be diamond-like, graphite-like, or amorphous, and the film thickness is 150λ to 800λ. The above can be formed by any method such as vacuum evaporation method, sputtering method, ion blating method, or CVD method.

Next, the polymer thin film having imide groups is formed by a sputtering method using at least one type of polymer selected from polyimide, polyimide amine, and polyimide amine as a target, and a fluororesin is further added to the polymer. ,
MoB2, WS,.

When at least one substance selected from B 27 and carbon is contained, the coefficient of friction between the obtained thin polymer film and the head is further reduced, which is more desirable. A thin polymer film containing imide groups may be formed by coating and baking a hanging monomer or pre-thalimer, and there are many commercially available materials.
For example, Trenice 2000, A'P400 (East),
DA-5ND (Musei Kagaku) etc., adjust the concentration with an appropriate solvent, apply by a known method such as spin code method, spray method, 9 uniform velocity pulling method, and heat at 150 to 230 ° C. for 1 hour to 5 days. Bake for an hour. In either method, the film thickness is 100~
500X is suitable.

[Effect]

According to the above configuration of the present invention, a thin film made of at least one substance selected from oxides, nitrides, carbides, and carbon, which has an excellent anticorrosive effect, excellent film hardness, and a low coefficient of friction, is formed on the metal medium. However, a return defect occurs in the thin film, and it is impossible to completely eliminate the defect due to the manufacturing process. Therefore, by further covering the thin film with a polymer thin film having an imide group that has completely different properties from the thin film, it is possible to layer the protective film and minimize the occurrence of defects, and the metal medium can be protected against wear due to moisture etc. While providing protection from the environment, by forming a highly hard film under the polymer thin film containing imide groups, the mechanical reliability between the polymer thin film and the head has been dramatically improved.

[Example 1] After plating NiP alloy plating as non-magnetic alloy plating on a mirror-finished disc-shaped aluminum alloy substrate to a thickness of about 20 μm, polishing the plate to a thickness of 15 μm and a surface roughness of 103 μm or less, Furthermore, as a metal magnetic thin film, Co
-N1-P alloy was plated to a thickness of approximately Q, 07 μm.

Next, using a magnetron sputtering device, 100^ of Cr and S
in, was formed continuously for 5ooK.

Furthermore, using Kapton as a target, a polyimide thin film was formed for 200 years under the following sputtering conditions.

[Example 2] A disk having a metal medium was produced in the same manner as in Example 1.

Next, with a magnetron sputtering device, a T1 of 50^ and a carbonaceous film (amorphous) of 4001 were formed, and a T knee of 21
An imidoamine thin film containing carbon lMoS2 and fluororesin was formed for 300 years under the following sputtering conditions using No. 30 polymer (TOSHI) as a target.

[Example 5] 5ooX of Or was applied to a polished N1-P alloy plated disk substrate using a magnetron sputtering device.

Then, Cr O-N i -Or alloy (co, -30a
t.

%N i , -7.5at, %Or ) for 900 years,
Further, 300X TiN was formed.

During sputtering, the oxygen partial pressure was maintained at 8×10 −'torr or less, and the above 3N was continuously formed.

Furthermore, 500 imidoamine thin films were formed in the same manner as in Example 2.

[Example 4] A disk having a metal medium similar to that in Example 1 was produced.

After diluting tetramethoxysilane in butanol, (1
-M) Acetic acid was added to obtain a hydrolyzed solution.

(The solid content concentration was calculated as SiO and was set to 0.5%.) The above hydrolyzed solution was dripped onto the entire disk surface using the spin code method (one side of the disk at a time), and the solution was heated at 11,000 rpm.
The sample was rotated for 20 seconds and pre-baked at 65°C for 10 minutes.

Next, a 0.01% diluted solution of DA-5ND was applied using the spin code method in the same manner as above, and then main firing was performed at 200°C for 2 hours to form a polysilicate film of 600m and a polyimide film of 200m. [Example 5] A disk having a metal medium similar to that in Example 1 was produced.

Next, using a magnetron sputtering device, Ta was added to 100^
, Tag! After forming 500 ml of T-1100 polymer (Toshi) under the same sputtering conditions as in Example 2, 500 ml of T-1100 polymer (Toshi) was formed.

In the examples, a disk coated with a polymer thin film having an imide group was prepared as a comparative product and quality evaluation was performed at the same time.

Comparative Example In Example 1, 200 people formed a polyimide thin film directly on a metal medium except for the formation of Or and Sin.

The quality evaluation of the disc described in the above examples and comparative examples is as follows:
ASS test and moisture resistance test were conducted. In the aSS test, the coefficient of static friction and the rate of decrease in output were determined, and the humidity test was conducted at 80℃, 8
The disk was left in an environment of 0% R, H, and the number of missing pits was checked over time, and the time when the number of missing pits increased was defined as the end of the service life.

〔Effect of the invention〕

As described above, according to the present invention, it has become possible to provide a disk compatible with high-density recording that has sufficient mechanical reliability and corrosion resistance using a U film.

The present invention is also applicable to floppy disks, magnetic tapes, and magneto-optical disks in which the substrate is made of plastic, and the material of the substrate, such as glass, is not limited to the embodiments.

that's all

Claims (4)

[Claims] (1) A metal magnetic thin film medium is coated on the substrate, a thin film made of at least one substance selected from oxides, nitrides, carbides, and carbon is coated on the metal magnetic thin film medium, and 1. A magnetic memory characterized in that its surface is coated with a thin polymer film having at least an imide group. (2) A coating made of at least one substance selected from Cr, Ti, Ta, and Nb between the metal magnetic thin film medium and a thin film made of at least one substance selected from oxides, nitrides, carbides, and carbon. 2. A magnetic storage body according to claim 1, characterized in that said magnetic storage body is formed with:. (3) The magnetism according to claim 1 or 2, wherein the polymer thin film having imide groups is made of at least one polymer selected from polyimide, polyimide amide, and polyimide amine. Memory body. (4) The polymer thin film having imide groups is made of fluororesin, Mo
The magnetic memory according to claim 1 or 2, characterized in that it contains at least one substance selected from S_2, WS_2, BN, and carbon.