JPH01205718A - Production of magnetic recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a high density magnetic recording medium.

Conventional technology Generally, ferromagnetic metals or alloys are vacuum deposited.

Magnetic recording media, which are made by depositing on a polymer film by sputtering or by bonding magnetic powder together with a binder component on a substrate, come into violent sliding contact with a magnetic head during recording and reproduction, which can cause the magnetic layer to wear out. Although ferromagnetic metal thin film layers formed by vacuum evaporation have characteristics suitable for high-density recording, they are susceptible to wear and damage due to high-speed sliding contact with magnetic heads, and have poor durability. there were. For this reason, efforts have been made to improve wear resistance by providing various protective film layers on the magnetic layer. (Japanese Patent Application Laid-Open No. 59-12723), and a diamond-shaped hard carbon film is provided (Japanese Patent Application Laid-open No. 59-12723).
2) and other methods have been proposed.

Problems to be Solved by the Invention However, in order to ensure a sufficient C/N ratio in a shorter wavelength region in the magnetic recording medium having the above-mentioned configuration, it is necessary to make the diamond-like hard carbon film thinner.

On the other hand, if the carbon film is made too thin, the durability will not be sufficient.

In view of these problems, it is an object of the present invention to provide a method for manufacturing a magnetic recording medium that can provide sufficient durability with a film thickness that cannot be obtained by conventional manufacturing methods.

Means for Solving the Problems In order to solve the above-mentioned problems, the method for manufacturing a magnetic recording medium of the present invention involves forming a diamond-shaped hard carbon thin film on a ferromagnetic metal thin film, and then sputter-etching the carbon thin film. A lubricant layer is formed on the upper layer.

Function: A diamorado-like hard carbon film is formed once using the above manufacturing method and then processed to a predetermined film thickness by sputter etching, so a film with no defects can be produced even if it is thin, ensuring sufficient durability with C/N. You can get a good balance.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. The figure is an enlarged cross-sectional view of a magnetic recording medium obtained by a manufacturing method according to an embodiment of the present invention. In the figure, 1 is a polymer film such as polyethylene terephthalate, polyphenylene sulfide, polyether sulfonate, polyamideimide, etc. If necessary, a film with an undercoat layer containing fine protrusions such as fine particles or water-soluble polymer protrusions is used. You can. 2 is Co −N i , Co
-Cr.

It is a ferromagnetic metal thin film such as Co-Ti, Co-Mo, Co-0, Co-Ni-0, etc., and can be formed by electron beam evaporation, ion blating, sputtering, or the like. Next, a diamond-shaped hard carbon film 3 is formed to a thickness of 300 to SOO by using hydrocarbon gas plasma or sputtering using graphite as a target. r,
This is the preferred thickness for ensuring high output by minimizing spacing loss during high-density recording by performing cis-butter etching with a discharge gas such as A r 102.
The diamond-shaped hard carbon film 3 is reprocessed to be thinner in the range of o8 to 160. Thereafter, a lubricant layer 4 of fatty acid, fatty acid amide, perfluorocarboxylic acid, perfluoropolyether, etc. is applied by vacuum evaporation, solution coating, etc., and the tape or disk shape is processed into a magnetic recording medium.

Examples will now be described in more detail in comparison with comparative examples. A polyethylene terephthalate film with a thickness of 10 μm was placed along a cylindrical can with a diameter of 1 m, and Co-N1 (Ni: 20 wt%) was injected onto the film at a minimum incident angle of 42 degrees in oxygen at exlo (Torr).
．． After 11 μm electron beam evaporation, transfer to another vacuum device, arrange 4 graphite targets in series, and apply 13.56 (MHz), 1 (%) to 1 target.
KW) high frequency power is input, Ar+H2=0.04(
Torr), aa by high frequency sputtering using a discharge gas of Ar:H2=1:3.

A diamond-like hard carbon film is formed. Next, graphite electrodes were arranged in 6 projection rows, and a voltage of +4 ts o (V) was applied to the graphite electrodes, so that A r
+02=0.02 (To r r ), Ar
The hard carbon film was sputter etched under the conditions of 202-1+ and 2, and part of it was etched by reactive sputter etching with Co2.
The aim was to achieve high-speed etching. The hard carbon film was made to have a thickness of 110 by sputter etching. The hard carbon film thus obtained formed a portion of fine dome-like irregularities. Methyl caprate was deposited on this upper layer by 40 people using a vacuum deposition method, and then processed into an 8 mm wide magnetic tape. On the other hand, in the comparative example, only the high frequency sputtering part was operated, and one graphite target
(MHz) and eoo(w) were introduced and 120 diamond-shaped hard carbon films were formed under the same conditions as in the example. Both tapes were compared and evaluated using 8mm video.

In the example, after 100 runs at 40°C and 80% RH, the luminance signal output was -0.3 to -o, + (dB), while in the comparative example, after 28 runs, The running performance deteriorated, and at that point the output was -1.3 to -1.5 (dB). 4
Repeat the condensation cycle at 0°C and 20°C every 4 hours, 3
When the tape was left for a week, the output of the example showed no change from the initial stage, while the output of the comparative example varied from -0.6 to -+.
It was unstable at 9 (dB).

Effects of the Invention As described above, the manufacturing method of the present invention has the excellent effect of manufacturing a high-density magnetic recording medium with excellent storage characteristics and durability.

[Brief explanation of the drawing]

The figure is an enlarged sectional view of a magnetic recording medium obtained by the method of the present invention. 3...Diamond-like hard carbon film, 4...
...Lubricant layer. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Polymer film? - Dokui surname, small genus, thin section, ? ---Dia Sodan 组R Page 4L end material ---1 To many; t no P''

Claims (1)

[Claims] Manufacturing a magnetic recording medium characterized by forming a diamond-shaped hard carbon thin film on a ferromagnetic metal thin film, then sputter etching the hard carbon thin film to a predetermined thickness, and forming a lubricant layer on the hard carbon thin film. Method.