JPH03250425A - Method for manufacturing magnetic recording media - Google Patents

Abstract

PURPOSE:To obtain a Co-Cr perpendicular magnetization film at <=100 deg.C film heating temp. by specifying the gas emission amt. from a traveling polymer film during the process of electron beam vapor deposition of the Co-Cr perpendicular magnetization film on the polymer film. CONSTITUTION:The polymer film 5 is released from a roll 6 in a vacuum chamber, introduced along a heater roller 7 to a deposition can 8. A Co-Cr perpendicular magnetization film is formed on the deposition can 8 with a vapor flow from a vapor source 10 heated by an accelerated electron beam 9 and partly shielded with a mask 11 which is provided to limit the incident angle range of the beam. Then the film is rolled up by a roller 12. In this process, traveling direction of the film can be controlled to both directions along the heater roller 7 to degas the film. The amt. of gas emitted from the film repeatedly traveled is specified to 3X10<-4> (Torr.l/sec). Thereby, high-performance perpendicular magnetization film can be obtained by electron beam vapor deposition even at low temp.

Description

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

Conventional technology Perpendicular recording, which utilizes antiparallel residual magnetization perpendicular to the substrate surface, is expected to produce high output in high-density recording. This system uses a magnetic recording medium with a magnetic recording layer made of perpendicularly magnetizable material such as a Co-Cr film, a perpendicular head with a strong perpendicular magnetic field, and a ring-type magnetic head that has been widely used. have been combined, and recently, instead of the micrometer-order permalloy thin film that was needed in the early days,
It has been shown that high-density recording can be achieved with a ring-type magnetic head even with a permalloy film of about 100 ml (for example, Journal of the Magnetics Society Op Japan).
agnetics 5ociety of Japan
) Vo113, Supplement ASl, 21
28 (1989)], it is getting closer to practical application. From the perspective of a media manufacturer, C is applied directly to the polymer film.

It is most desirable to be able to put it into practical use by forming a perpendicularly magnetized film such as a Cr thin film. Further, regarding the film forming speed, electron beam evaporation method or a high speed film forming method similar thereto is most preferable.

In order to improve the performance of a Co-Cr film using the electron beam evaporation method as a perpendicularly magnetized film, in addition to raising the substrate temperature to 20Q°C or higher, irradiation with an ion gun has been devised. 7, (IEEE Transactionson M
agnetics) Vol, MAG-25, A5.4
183-4185 (1989)) It has become possible to obtain properties close to those known by the Nupa Sotaring method.

Problems to be Solved by the Invention However, in order to obtain good characteristics with the method of forming a perpendicularly magnetized film using electron beam evaporation, it is necessary to expose the substrate to high temperatures. Polymer film must be used. Recently, lowering the temperature using Co-0 based perpendicular magnetization film has been reported and attracting attention, but C
c. since it does not match the high-density recording characteristics of the o-Cr perpendicularly magnetized film.

There is a demand for lowering the temperature of -Cr perpendicularly magnetized films.

The present invention was made in view of the above circumstances, and
The present invention provides a manufacturing method in which an r-based perpendicular magnetization film can be obtained by heating the film at 100° C. or less.

Means for solving the problem The means for solving the above problem is to reduce the amount of gas released from the polymer film when forming a Co-Cr perpendicularly magnetized film on a moving polymer film by electron beam evaporation. 3
x 1o −4 [Torr-e leakage].

Function: The method for manufacturing a magnetic recording medium of the present invention has the above-described configuration, so that the initial layer of Co-Cr crystal growth becomes in-plane magnetized.
This can prevent the recording performance of the ring head from deteriorating. In other words, C, which is important in crystal growth even in the initial stage,
This is because the presence of gas molecules that disturb the vertical alignment of the axis with respect to the substrate surface can be ignored.

EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings. FIG. 1 is an enlarged sectional view of a magnetic recording medium manufactured by the manufacturing method of the present invention. In Figure 1, 1 is polyethylene terephthalate.

A polymer film such as polyethylene naphthalate may be used, but an aramid film or a polyimide film may be used for mechanical strength rather than heat resistance.

2 is a fine particle coating layer placed for the purpose of improving durability.
When the polymer film of the claim is provided with this layer, it is of course aimed at the amount of gas released including this layer.

3 is Co-Cr, Co-Ni-Cr.

Co-Cr-Nb, Co-Cr-Ta, Co
-Pt-Cr,C.

It is a Co--Cr based perpendicular magnetization film such as Cr--Rh, 4 is a protective lubricating layer, and 6 is a back coat layer.

FIG. 2 is a block diagram of the main parts of a vapor deposition apparatus used to carry out the manufacturing method of the present invention. In FIG. 2, the polymer film 6
is a part of the vapor flow emitted from the evaporation source 1o, which is sent out from the take-up shaft 6 (which has a heating mechanism), is guided to the evaporation can 8 via the heating roller, and is heated by the accelerated electron beam 9. The structure is such that a perpendicularly magnetized film of Co--Cr yarn is formed by the vapor flow passing through a mask 11 that limits the incident angle range of the yarn, and is then wound up on a winding shaft 12.

In Figure 2, 13 is a vacuum container, 14 is an upper chamber that includes degassing and winding, 15 is a lower chamber that occupies a space for vapor deposition, 16 and 17 are vacuum exhaust systems, and 18 is an electron The beam generator 19 is a free roller.

In Figure 2, the diameter of the Nather roller is 300, and the holding angle is i3.
000 The vapor deposition can has a diameter of 50α, and the diameter is 26
The evaporation surface was placed on 1, and comparative evaluations were made between the examples and comparative examples described below. Winding control was made bidirectional so that it could be moved repeatedly along the heating roller for degassing.

The deposition can temperature is kept constant at 30°C, and the auxiliary roller is set at 70°C.
It can be controlled in the range of ~290'C,
The amount of gas released was varied by repeated running, and under different gas release conditions, Co-Cr (Cr20.5 wt%) was actually deposited with a 0.2 μm electron beam with components within an incident angle of 10 degrees (3800 people/5ec). Approximately 60 people applied a commercially available perfluoropolyether (Fuonblin Z-25C made by Montageson) on top of the ring head (cap length 0.1
5 μm, i-layer amorphanu type) with a bit length of 0.2 μm, and the reproduction sensitivity was compared.

The polymer film is polyethylene terephthalate.

Films of polyphenylene sulfide, polyethylene naphthalate, polyether ether ketone, aramid, and polyimide with a thickness of 11 μm and an average surface roughness of 40 to 4
There were 6 people. 0 (dB) on polyimide film,
After depositing a 100-layer Vermalon film thin film using high-frequency sputtering method, a 0.2-μm thick film was deposited using high-frequency sputtering method.
A Co-Cr (Cr20.4wt%) perpendicular magnetization film is arranged,
This is the value of the playback output of a tape with 6o of Fonblin Z-25 inserted. FIG. 3 shows the results of plotting the reproduction output distribution using the amount of gas released as a parameter.

From Figure 3, 3 X 10-'-4 [Torr-1/5e
c) It can be seen that it can be controlled within 1 (dB) as long as the following values are maintained. Note that the deposition rate is 3800 (8/5) in this example.
ec), but as expected, 1oo entered/East~
As the speed decreases to 500 people/required, the effect of gas release becomes severe, and the speed decreases to 3X10'-4 [Torr-
l/sec), there will be variations in the playback output.

Since the present invention is premised on mass production scale, 3000 (
(person/5ec) is considered to be the lower limit. If it is within that range, 3
It can be said that a magnetic field of ×10 −4 [Torr−1 /5 ec) can be applied. Although FIG. 3 does not include those provided with a fine particle coating layer, they may be treated in the same manner.

Another means for solving the problem is to set the evaporation rate on the side where electron beam evaporation is started to be 300 (input/5 ec) or less. In the method for manufacturing a magnetic recording medium of the present invention, the initial crystallinity is improved by the above-described structure, and it is possible to improve the performance of the perpendicularly magnetized film while maintaining the high speed of electron beam evaporation in total. Figure 4 shows the primary mask on the evaporation start side used to carry out the present invention.In addition to the mask provided near the can for regulating the incident angle, it is provided on the side near the evaporation source to effectively The deposition rate is P in the figure.
It can be varied by adjusting
(person/sec), and the critical 300 (person/sec)
5ec) The following shall be achieved. The deposition starting side may be 1/10 to 1/30 of the total film thickness. The can temperature ranges from 0℃ to 45℃, and the amount of Ganu bath is 5x1
o -4 [Torr-d/5ec) ~7X10
'-4 [TorrJ/5ec). C
o-Cr (Cr20.7 wt%) was deposited with an electron beam at an incident angle of 6 degrees or less, and the playback output of the tape was compared using the same criteria as in Figure 3, using the formation rate of the initial growth layer as a parameter. Figure 5 shows the results. Shown in the figure. It was separately confirmed that similar results were obtained with materials other than Co- and -Cr, and that the effects of the present invention could be maintained as long as the incident angle was within 40 degrees.

Effects of the Invention As described above, the present invention has the excellent effect that a high-performance perpendicular magnetization film can be obtained by electron beam evaporation even at low temperatures.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of a magnetic recording medium obtained by an example of the present invention, FIG. 2 is a diagram showing the main part of a vapor deposition apparatus used to carry out the manufacturing method of the present invention, and FIG. 3 is a gas release FIG. 4 is a diagram showing the main parts of the apparatus used to carry out another embodiment of the present invention, and FIG. 5 is a diagram showing the correlation between initial formation speed and relative output. 1.6... Polymer film, 2... Fine particle coating layer, 3... Co-0r perpendicular magnetization film, 4...
Old...Protective lubricant layer, 7...Heating roller, 8...
Mouth... Evaporation can, 1°... Evaporation source, 21...
Mountain first mask.

Claims (2)

[Claims] (1) When forming a Co-Cr-based perpendicularly magnetized film on a moving polymer film by electron beam evaporation, the amount of gas released by the polymer film is 3×10^-^4 [Torr・l
/sec]. (2) A magnetic recording medium characterized in that when forming a Co-Cr-based perpendicularly magnetized film on a moving polymer film, the evaporation rate on the side where electron beam evaporation is started is 300 (Å/sec) or less manufacturing method.