JPS6378338A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a perpendicularly magnetized film having durability and good signal to noise ratio C/N in a large amt. by constituting vapor flow of neutral particles at the time of projecting the vapor flow of a ferromagnetic metallic material nearly perpendicularly onto a high-polymer film. CONSTITUTION:The vapor flow is constituted of the neutral particles at the time of projecting the vapor flow of the ferromagnetic metallic material nearly perpendicularly onto the high-polymer film 1. An electron beam vapor source 2 is disposed right under a can 4 and the trapping of charge particle components is executed in a magnetic field so that neither positive nor negative ions and electrons are incorporated into the neutral vapor flow 3. While in the conventional process for production the particles having electric charge are incorporated into the vapor flow as the high-polymer film is an insulator and such charge accumulation leads to microscopic nonuniformity and is the cause for noise with extra-short frequencies, such troubles are eliminated according to the above-mentioned method and the magnetic recording medium having the good C/N over a wide area is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a magnetic recording medium in which a ferromagnetic metal thin film is a perpendicularly magnetizable magnetic recording layer suitable for high-density magnetic recording.

Conventional technology A new perpendicular magnetic recording method is attracting attention as a magnetic recording technology that will lead to higher density in the next generation.
TIC8) vol.

MAG-13, boiled 6. p, p, 1272-1277 (1
syy)).

In perpendicular recording, an antiparallel magnetization transition perpendicular to the medium surface is formed, so the magnetization transition becomes extremely narrow and high-density recording is possible. Therefore, it is important to establish mass production technology for durable media with a high signal output-to-noise ratio (hereinafter referred to as C/N) [Applied Magnetics Seminar, 6 Perpendicular Magnetic Recording Methods 2'' ( SO December)].

Currently, the sputtering method [Japan Society of Applied Magnetics, 3'9]
Refer to the Annual Research Meeting Materials p, 31 (1985)] Electron beam evaporation method [Transactions of the Institute of Electronics and Communication Engineers f66-C.

AI, p, ss (1983)] are both Co-C
The electron beam evaporation method is being studied mainly for r-films, but
Although it requires vapor deposition at high temperatures and is inferior to sputtering in terms of vertical alignment, its high speed is a major advantage for industrialization, and improvements including measures against heat blistering are continuing.

Problems to be Solved by the Invention However, it is not possible to form the film by electron beam evaporation by simply adjusting the above-mentioned configuration, the regulation of the incident angle, the regulation of the true projection variation, the set temperature of the cylindrical can, the pretreatment of the polymer film, etc. The perpendicularly magnetized film produced by this method has an output level comparable to that obtained by sputtering, but the problem is that it produces a lot of noise, and improvements are desired. The present invention has been made in view of the above-mentioned circumstances, and provides a manufacturing method suitable for producing a large amount of perpendicularly magnetized films with good C/N.

Means for Solving the Problems The method for manufacturing a magnetic recording medium of the present invention is such that when a vapor flow of a ferromagnetic metal material is irradiated onto a polymer film at approximately perpendicular incidence, the vapor flow is composed of neutral particles. It was designed so that

Effect: The method for manufacturing a magnetic recording medium of the present invention has the above-described configuration, and since in the conventional manufacturing method, charged particles are contained in the vapor flow because the polymer film is an insulator, this charge accumulation is avoided. This makes it possible to remove microscopic non-uniformity and cause noise at extremely short wavelengths, making it possible to obtain a magnetic recording medium with good pc/H over a large area. This is what happens.

EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of main parts of a vapor deposition apparatus used to carry out the present invention. In Fig. 1, 1 is a polymer film, 2 is an electron beam evaporation source, 3 is a limited neutral vapor flow, 4 is a rotating support whose temperature can be controlled, 5 is an unwinding shaft, 6 is a winding shaft, and 7 is a winding shaft. 8 is a charged particle trap magnetic field generator; 8 is a shielding plate with slits for vapor deposition with nearly vertical components; 9
is a vacuum container, and 1o is a vacuum evacuation system.

FIG. 2 is an enlarged sectional view of an example of a magnetic recording medium that can be obtained according to the present invention, in which 11 is a polymer film, 12 is a perpendicular magnetization film, and 13 is a lubricating layer.

In the apparatus shown in Fig. 1, the rotating support is a cylindrical can (diameter 50
cm), and the electron beam evaporation source is 47 cm directly below the can.
The trapping of charged particle components is performed by a magnetic field, and the positive field is placed in a neutral vapor flow.

No negative ions or electrons were included. The incident vapor flow component was within 10 degrees.

The electron beam evaporation source was heated with a 1 sKV, 30KW Pierce type electron gun.

Aromatic polyamide with mountain-like folds (height: 100) on the surface was used as 12, and Co-Cr (Cr
20.4 wt%) perpendicular magnetization film 13.0.15) tm is disposed, and stearic acid amide 80% is deposited thereon using a vacuum evaporation method to form a lubricating layer 14. Next, I compared the C/N with a modified 8mm video deck.

The rotating drum temperature was kept constant at 146° C. in both the example in which the trapping magnetic field was adjusted and a Go—Cr film was formed with a neutral vapor flow, and the comparative example in which a Co—Cr film was formed without the trapping magnetic field.

The video head used on the modified deck has a gap length of 0.
．． 16. mm ferrite head, recording wavelength is 0.5 mm
．． Comparison was made at two points: l1m and 0.33)tm.

The example has a difference of +2.1(d) at 0.5)tm compared to the comparative example.
B), -0.33μ, the improvement was significant with +s, 7 (dB).

Furthermore, when 100 arbitrary tapes are selected and a wavelength of 0.4/jm is recorded, the C/H value at 1000 arbitrary points is:
The variation in the Example was within 1 (dB), but the variation in the Comparative Example was as large as 3.7 (dB), confirming the uniformity of the Example.

In the above embodiments, aromatic polyamide was used as the polymer film, but polyethylene terephthalate, polyphenylene, etc. Polyimide, polysulfone, etc. may also be used.

As a perpendicular magnetization film, in addition to Co-Cr film, Co-0°Co
-W, Co-Mo, Co-Ti, etc. may also be used.

Effects of the Invention As described above, according to the present invention, C/
Since the perpendicularly magnetized film can be uniformly formed over a large area due to the good quality of N,
There is an excellent effect that an excellent magnetic recording medium for perpendicular magnetic two-scythe can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of essential parts of an example of a vapor deposition apparatus used to carry out the present invention, and FIG. 2 is an enlarged sectional view of an example of a magnetic recording medium that can be manufactured according to the present invention. 1.11...Polymer film, 2...
Evaporation source, 3...neutral vapor flow, 4...rotating support, 12...perpendicular magnetization film, 13...
...Lubricating layer. Name of agent: Patent attorney Toshio Nakao and 1 other person/
--Ichitaka Nako film? ---Electron Beam Voice, Fan Fu 3-Ichisei Kanki 2

Claims (1)

[Claims] A method for producing a magnetic recording medium, characterized in that when a vapor flow of a ferromagnetic metal material is irradiated onto a polymer film at substantially perpendicular incidence, the vapor flow is composed of neutral particles.