JPS63251936A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To uniformly obtain good C/N in high-density magnetic recording and reproducing at a high speed and to permit formation of a material for which there are heretofore no available mass production means to a thinner film by using a moving vapor deposited film to form a target at the time of forming a thin ferromagnetic metallic film by sputtering vapor deposition. CONSTITUTION:The endless target 14 is constituted of titanium foil or nonmagnetic stainless steel foil, etc., and deposited with the thin ferromagnetic metallic film by evaporation on the surface opposite to a high-polymer film 10. More specifically, the target 14 is constituted of the moving vapor deposited film at the time of forming the thin ferromagnetic metallic film by the sputtering vapor deposition on the moving substrate 10. Since the ferromagnetic part of the target is thin, an electromagnetic field for trapping electrons does not change and is strong and, therefore, uniform conditions are maintained and the higher speed is obtd. Since the constituting elements are merely required to be discretely controlled and taken into the vapor deposited film, even the material which cannot be worked to a sheet is usable as a sputtering target.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium using a ferromagnetic metal thin film as a magnetic recording layer.

Conventional technology In recent years, there has been remarkable progress in increasing the density of magnetic recording.
It has become necessary to develop new technology for the combination of magnetic heads and magnetic recording media. That is, as the recording unit becomes smaller, the amount of magnetic flux decreases, so it has become essential to use materials with high magnetic flux density in order to maintain the practical level of 07N for magnetic flux differential type recording and reproduction. [
Japanese Patent Publication No. 5B-91, Japanese Unexamined Patent Publication No. 139919/1982]. Such magnetic recording media are produced by electron beam evaporation onto polymer films such as polyester films and polyimide films while cooling with a rotating support.

It is obtained by forming a ferromagnetic metal thin film using ion blating method, sputtering method, etc.
Japanese Patent Publication No. 61-47221, Japanese Patent Publication No. 57-2104
No. 52, JP-A-60-59534, JP-A-Sho 6
1-240437].

Among magnetic recording media, the electron beam evaporation method is mainly being considered for manufacturing magnetic tapes, and the sputtering method is mainly being considered for manufacturing magnetic disks. Furthermore, as sputtering methods, applications such as RF magnetron discharge, DC magnetron discharge, and facing target type are being considered [for example, Japanese Patent Laid-Open No. 61-2636
36-263638].

FIG. 2 is a block diagram of the main parts of a magnetic recording medium manufacturing apparatus to which the sputtering method is applied. In Fig. 2, 1 is a polymer film, 2 is a rotating support, 3 is an unwinding shaft, 4 is a winding shaft, 5 is a plate-shaped target of a ferromagnetic alloy, 6 is a magnetic field generator, 7 is a vacuum chamber, 8 is a vacuum exhaust system, and 9 is a free roller. There are some ideas such as making cuts in the target to increase the leakage of the magnetic field and speed up the sputtering speed.
Since a region where sputtering is concentrated, called a double loss zone, occurs over a certain period of time, the actual situation is that conditions are delicately adjusted in response to changes in sputtering speed.

Problems to be Solved by the Invention However, with the above configuration, when the recording density increases, the modulation noise may become uneven depending on the location, and there is a desire for improvement, and there is a limit to how high the speed can be increased. There are certain problems, such as the fact that materials that cannot be processed into plate shapes cannot be used as ferromagnetic metal thin films, and improvements have been desired.

The present invention has been made in view of the above-mentioned circumstances, and provides a method for manufacturing a magnetic recording medium that can manufacture a magnetic recording medium with good and uniform high-density recording and reproduction characteristics (C/N) at high speed. It is.

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 comprises a deposition film in which a target moves when a ferromagnetic metal thin film is sputter-deposited on a moving substrate. This is what I did.

Operation The method for manufacturing a magnetic recording medium of the present invention has the above-described structure, and since the ferromagnetic part of the target is thin, the magnetic field for trapping electrons does not change and is strong, so it is possible to maintain uniform conditions. , speed can be increased to the right. Furthermore, since the constituent elements can be individually controlled and incorporated into the deposited film, even materials that cannot be processed into plates can be used as sputter targets.

EXAMPLE Hereinafter, a method for manufacturing a magnetic recording medium according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of main parts of a sputter deposition apparatus used to carry out the present invention. In Figure 1, 10 is a polymer film such as polyethylene terephthalate or polyphenylene sulfide, 11 is a rotating support, 12 is a film feed shaft, 13 is a winding shaft, and 14 is an endless target, which is made of titanium foil or non-magnetic material. A ferromagnetic metal thin film is deposited on the surface facing the polymer film. 16 is a rotating roller type gas introduction nozzle, 16 and 17 are evaporation materials, 18 is an evaporation source container, 19 is a vacuum chamber, and the upper chamber 2o and the lower chamber 21 are separately vacuumed. It is designed to exhaust the inside of the tank, and the figure shows 2.
Only the vacuum evacuation system of No. 2 is shown. 23 is part of the belt, above.

It is designed to maintain the differential pressure between the lower chambers.

24 and 25 are rotating rollers, and 26 and 27 are magnetic field generators for applying magnetron discharge to sputtering. In Figure 1, the diameter of the rotating support is 60mm,
The belt is made of titanium foil with a thickness of 26 μm.
The length of each arm OA2 was 22 mm, the close distance to the rotating support was 5 mm, and the magnetic field strength was 16 Q (Os) on the surface of the endless belt. The rotating roller nozzle is
A cylinder with a diameter of 2 mm was divided into 8 equal parts, and 16 holes each having a diameter of 3 mm were arranged in the width direction of the polymer film. The method of sputtering is to place one vapor-deposited layer onto titanium foil with O,2
The deposition conditions and sputtering conditions were adjusted to keep the thickness within the range of 5 μm to 1 μm, and the circumferential speed of the endless belt was kept constant at 1 m/m1n.

A polyethylene terephthalate film with a thickness of 10 μm was used, on which 100 Al2O3 fine particles with a diameter of 10 μm were placed on average, and CoNi (N
i20wt%) was deposited in a 0.15 μm x grasshopper evaporation manner. In the comparative example, a plate-shaped target with a thickness of 10 mm was used, and the magnetic field strength was applied to a glow discharge in which 1.65 (KW) of high-frequency power of 13.56 (MH2) was input at a gas pressure of 2 x 10'' (TOrr). Sputter deposition was carried out by magnetron discharge in combination with 3o (0θ).The film feeding speed was 4.2 (m/m1nl).On the other hand, in the example,
A mixed gas of r10□=1o/1 was introduced from a rotating roller type nozzle, and the temperature was 13.5 at 4.5X10 (Torr).
6 (MHz).

Sputter deposition was performed using a 1.65 KW magnetron discharge. The film feed speed is 3°rn, which is more than 7 times faster.
It was 7 min.

40 people vacuum-deposited perfluorooctanoic acid on each.
Commercially available 8mm video [”
VX-sol, made by Kishita Denki] was modified to set the recording wavelength to 0.
．． A comparison was made of 07Mft when the diameter was 66μm. The example showed 07N which was 3.9 (dB) better than the comparative example. This is because the noise has been improved. From these comparisons, the present invention has excellent high-speed performance and good C/N ratio, and its value can be understood.

Furthermore, according to the present invention, good magnetic properties could not be uniformly obtained until now. For Co-B (because it cannot be processed into a plate, the sputtering method can only be done on a small scale in the laboratory by crushing B on a CO plate), and it is possible to obtain uniform properties at high speed. , Co-0r, Go-W,
Co-Ti and the like are also capable of increasing speed, and their advantages can be utilized regardless of whether they are in-plane or perpendicular.

Effects of the Invention As described above, according to the present invention, a good C/N can be obtained uniformly and at high speed in high-density magnetic recording and reproduction, and materials for which there was no conventional means of mass production can be made into thin films for magnetic recording. It has the excellent effect of being able to provide

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of a sputter deposition apparatus used to carry out a method for manufacturing a magnetic recording medium according to an embodiment of the present invention, and FIG. 2 is a block diagram of main parts of a conventional sputter deposition apparatus. . 10... Polymer film, 11... Rotating support, 14... Endless galley), 1
5...Gas introduction nozzle (rotating roller type). Name of agent: Patent attorney Toshio Nakao and 1 other person T4
-゛-Esorless target 1 (T5-°-1 sword) Figure 2

Claims (1)

[Claims] When sputter depositing a ferromagnetic metal thin film onto a moving substrate,
A method for manufacturing a magnetic recording medium, characterized in that the target is a moving deposited film.