JPH0261816A - Magnetic storage body, manufacturing method, and magnetic storage device - Google Patents

Abstract

PURPOSE:To improve corrosion resistance and durability and to reduce coefficient of friction against a head by laminating specified five-layered coating film on a substrate. CONSTITUTION:The medium consists of the substrate and the five-layered coating film laminated thereon. The five layers are metal magnetic medium, an oxide film of the element which constitutes this magnetic medium, a film of at least one material selected from carbides, oxides, nitrides and carbon, a condensation polymerization film of organic metal compound the molecule of which as a hydrolytic group in one end and at least one kind of functional group among amino groups and imino groups in the other end, and at least one metal salt of fatty acid with Li, Na, K, Cs or Mg. By this method, not only corrosion resistance but durability of the medium is improved because the metal magnetic medium is not affected by heat or humidity. The medium can be minimized and a coefficient of friction against a head is reduced. Reliability of a magnetic recording device using this medium is also improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to magnetic storage devices (magnetic disk devices, magnetic drum devices, and magnetic tape devices) and magnetic storage bodies (hereinafter referred to as storage devices) used in the 6N storage devices. body) and its manufacturing method.

[Prior Art] A storage body having a metal magnetic medium (hereinafter referred to as a metal medium) has sufficient mechanical reliability to withstand contact with a recording/reproducing head (hereinafter referred to as a head). Corrosion resistance is required to withstand corrosive environments such as moisture and chlorine.

Conventionally, the substrates used are AI2 alloy substrates, glass plates, ceramic plates, etc., which have been subjected to alumite treatment or non-magnetic plating treatment such as N1-P coating, and then polished to give them a mirror finish or surface finish. After non-magnetic plating such as N1-P, N1-Cu-P and coating with Cr, Bi, etc., a ferromagnetic metal medium is coated, and further SiO2 (including polysilicic acid), 7
)t[N, c, 5iiN4 and AI2□03 solid solution is coated with a protective film, and after the presence or absence of an intermediate layer using a coupling agent, a liquid lubricant such as perfluoropolyether, higher alcohol, or fatty acid is coated. A thin layer of solid lubricant is coated.

Although the above-mentioned memory bodies have a certain level of durability and have already begun to appear on the market, they have major drawbacks.

A magnetic storage device equipped with the above storage body was heated at 40℃80%R.
If left in an environment of H., galling points will occur in one or two places on one memory body, leading to a defect error. Furthermore, repeated contact between the storage body and the head increased the coefficient of friction between them, often causing the spindle motor to stop.

[Problems to be Solved by the Invention] Conventional techniques have had the problem of not being able to sufficiently ensure the corrosion resistance of the metal medium, and also not being able to sufficiently ensure the mechanical reliability between the storage body and the head.

The present invention solves the above problems, and its purpose is to dramatically improve the corrosion resistance of metal media in environments containing moisture, chlorine, etc. It is an object of the present invention to manufacture and provide a highly reliable memory body that has a significantly reduced coefficient of friction, maintains its effect for a long period of time, and to provide a magnetic memory device using the memory body.

[Means for Solving the Problems] The present invention provides a method in which a metal medium is coated on a substrate, a thin film of an oxide of an element constituting the metal medium is coated on the metal medium,
Next, a thin film made of at least one substance selected from carbide, nitride, oxide, or carbon is coated, and the first molecule has a hydrolyzable group on one side and at least one amino group or imino group on the other side. A polycondensation film of organometallic compounds having various functional groups is coated, and fatty acids and Li, Na, K
, Ca, and Mg.

The metal media can be coated using materials and methods similar to those of the prior art. C01Fe, Ni, Cr, Ta, P
, a coating is formed using a dry film forming method such as a wet plating method or a sputtering method using a metal made of a noble metal element or the like.

The oxides of elements constituting the metal medium include Co3O4, F
ex Ox, CrO3, Ta205. Dry film-forming methods such as PVD and CVD, which are typified by P2O5, wet film-forming methods such as thermal decomposition of organometallic compounds, or oxidation treatment methods in which the metal medium is exposed to plasma of a gas containing oxygen gas. or,
It is also possible to grow and form an oxide film by thermal oxidation or a surface oxidation treatment method using an oxidizing agent such as hydrogen peroxide, and the appropriate thickness is 50 to 200.

Carbides, nitrides, oxides are Aj2, B, Y, Si, T
It is a compound of elements selected from i, Zr, Hf, Nb, Ta, Cr, Mo, and W, and the mixing and lamination thereof are arbitrary. The carbon may be graphite, diamond, or amorphous (including i-carbon) alone, mixed, or laminated, and a film thickness of 100 to 400 carbon is appropriate for each. The above-mentioned compounds and carbon can be coated by a PVD method or CVD method such as a sputtering method or an ion blasting method, and the oxide can also be coated by a thermal decomposition method of an organometallic compound.

An organometallic compound having a hydrolyzable group on one side of the molecule and at least one functional group such as an amino group or an imino group on the other side is represented by the following formula.

R' e −M −(OR) m −42 where R
゛ is an organic group having at least one functional group such as an amino group or an imino group, and R is an alkyl group having 1 to 5 carbon atoms. Also, M is Si, Ti, Zr, Nb, Hf, Nb
, Ta, etc., and m is the valence of each metal element. Further, β is an integer from 1 to (m-1).

Representative organometallic compounds are shown below.

Nt(*-(CH2) x-NH-(CH213-3i
-(OCR, l 3CH.

NH2-(CH2) 2-NH-((:Hz) z-3
L-fOcH3) 2NH2-fcHz) a-NH-
[H to CH21t-NH-fcHil 2-3i-fO
a) s All of these are diluted with a soluble solvent such as alcohol, and then applied and baked to form a polycondensation film by a known method such as a spray method, a spinner method, a dipping method, or a pyrosol method. The concentration is determined by the thickness of the film that cannot be obtained, and a film thickness of a single molecule is sufficient, and a film thickness of about 200 molecules or less is not problematic. Also, firing is at 60°C to 200°C15
Minutes to 20 minutes is sufficient.

Metal salts of fatty acids and Li, Na, K, Ca, Mg include stearate metal salts, oleate metal salts, etc., but the fatty acids are not limited to being linear, branched, saturated, or unsaturated. These are dissolved and diluted in a soluble solvent such as methanol, and formed by a wet method such as a spinner method, dipping method, spray method, or pyrosol method, or vacuum evaporation method, and are heat-treated as necessary. A thickness of several tens of angstroms or less is sufficient.

[Function 1] According to the present invention, a metal medium having poor corrosion resistance is coated with a thin film of an oxide of an element constituting the insulating metal medium having excellent adhesion to the metal medium.

Since it is literally difficult to make the thin film thin and pinhole-free, thin films made of different compounds or carbon are laminated. This lamination makes it possible to drastically reduce the occurrence of pinholes in the case of the same film thickness, and protects the metal medium from erosion factors such as moisture and chlorine.

Next, the hydrolyzable group on one side of the molecule undergoes a dehydration condensation reaction with the OH or COOH groups present on the surface of the compound and carbon thin film, and the amino or imino group on the other side undergoes a dehydration condensation reaction with the fluorinated group that is then coated. Strong affinity with carboxyl groups of polyether polymers. As a result, even if the impact friction of the head is repeated, the metal salt of fatty acid, which has excellent lubricating ability, is not removed from the surface of the storage medium and maintains its effect for a long period of time.

As described above, it has become possible to manufacture and provide a memory body with excellent long-term mechanical reliability and storage reliability, and furthermore, by using this memory body, the long-term reliability of a magnetic memory device has been significantly improved.

[Example 1] After applying non-metallic N1-P alloy plating to a thickness of approximately 15 μm on a mirror-finished disc-shaped aluminum alloy substrate, polishing was performed to obtain a surface roughness of Ra = 70 to 120, Rmax
= 700 to 1500 people 1 The surface was processed to have a grain size, and Co-N1-P alloy plating was applied to a thickness of about 0.05 μm.

Sample A was then fired at 250° C. for 1 hour in an air atmosphere. Sample B is p) (92H20,z I
It was immersed in a 1% Vo aqueous solution (liquid temperature 60'C) for 1 hour.

Sample C was prepared by using a reactive etching device and using oxygen as the introduced gas at 0.2 t or r 0.5 W/
Sample D
A magnetron sputtering device was used, and the introduced gas was a mixture of Ar and oxygen (pressure ratio 49:1) at 5X10-'torr.
RF applied discharge (4W/cm") was applied to the Ni target in an atmosphere of do.

Samples A, B, C, and E were deposited using a magnetron sputtering device using the target and conditions listed in Table 1 at a power density of 4 W/cm. Samples D and E were deposited using the following treatment solution ( Using the dipping method (liquid temperature 25°C)
After coating at a speed of 10 am/min), it was baked at 200°C for 10 minutes to coat a 200 mm thick oxide-based thin film.

Treatment liquid composition Next, the organometallic compound shown in Table 2 was dissolved in Freon 113 and methanol (mixing volume ratio 3:1) at a concentration of 0005 W/V% (liquid temperature 25°C), dipping method (10 cm/
min ) and then at 110° C. for 10 minutes.

Furthermore, 0.03 W/V% of the fatty acid metal salt shown in Table 2 was added to a mixed solvent of methanol and Freon 113 (volume ratio 1:3).
(liquid temperature: 20℃), dipping method (10℃)
cm/min), and then baked at 80° C. for 10 minutes, and coated on a surface of 20 cm/min. The film thickness was measured by the step measurement method or the ellipsometry method.

Table 2 Table 1 Memory body manufactured by the above manufacturing method and 3370 type thin film head (Flyhide 0.15μm, 9m/5e
A magnetic storage device was produced using c) and evaluated by the following test. The results are shown in Table 3.

(1) C5Sii 1-year test C3S operation (rise and fall time 10 seconds)
Determine the change in appearance before and after, the coefficient of static friction, and the rate of decrease in output.

(2) Corrosion Resistance Test The product was left in an environment of 80°C, 190% R, H, and the number of missing pits was measured after the time had elapsed, and the time when the number of missing pits increased was determined to be the end of its life.

[Effect of the Invention 1] A 6N memory device using a thin film type memory body as a memory body compatible with high recording density has been on the market for some time, but its use has been limited to a limited number of people due to concerns about long-term reliability.

According to the present invention, even if the storage medium is used under heating, the metal medium will not be affected in any way in practical terms, and the mechanical reliability will be improved even when using heads that are becoming increasingly hard and have low fly bite. Since it is expensive, even if it is further miniaturized and installed in a magnetic storage device used in harsh environments, there will hardly be any noticeable deterioration in the characteristics of both the storage body and the head.

As described above, manufacturing of highly durable memory bodies compatible with high recording density,
By providing and using the storage body, it has become possible to provide a highly reliable magnetic storage device.

that's all Applicant: Seiko Epson Corporation Agent: Patent attorney Kisanbe Suzuki (and 1 other person) Table 3

Claims (3)

[Claims] (1) A metal magnetic medium is coated on a substrate, a thin film of an oxide of an element constituting the metal magnetic medium is coated on the metal magnetic medium, and then a thin film of an oxide of an element selected from carbide, nitride, oxide, or carbon is coated. A thin film made of at least one substance is coated, and then a polycondensation film of an organometallic compound having a hydrolyzable group on one side of the molecule and at least one functional group such as an amino group or an imino group on the other side. is coated, and further fatty acids and L
1. A magnetic memory body characterized by being coated with at least one metal salt of i, Na, K, Ca, and Mg. (2) A process of coating a metal magnetic medium on a substrate, a process of coating the metal magnetic medium with a thin film of an oxide of an element constituting the metal magnetic medium, and then a process of coating a thin film of an oxide of an element constituting the metal magnetic medium, and then a process of coating a metal magnetic medium with a thin film of an oxide of an element constituting the metal magnetic medium, and then a process of coating a metal magnetic medium with a thin film of an oxide of an element constituting the metal magnetic medium. A step of coating a thin film consisting of at least one substance selected from the following: an organometallic compound having a hydrolyzable group on one side of the molecule and at least one functional group such as an amino group or an imino group on the other side; A method for manufacturing a magnetic memory body, comprising the steps of coating a polycondensation film and further coating with at least one metal salt of a fatty acid and Li, Na, K, Ca, or Mg. (3) A magnetic storage device characterized by using the magnetic storage body according to item 1.