JPS5814325A - Production for magnetic recording medium - Google Patents

Abstract

PURPOSE:To mass-produce vertically magnetized recording materials efficiently, by performing all processes in the same vacuum system in the production for the vertically magnetized recording material where recording layers are provided on both sides of a substrate. CONSTITUTION:In the same vacuum system, vaporized materials 2 in vessel 2 are vapor-deposited to a substrate 1 fed from a feeding shaft 18 to form a soft magnetic layer consisting of Permalloy or the like while the substrate 1 traverses around a rotary can 14, and vaporized materials 3 in a vessel 11 are vapor-deposited to the substrate 1 to form a vertically magnetized recording layer consisting of Co-Cr or the like while the substrate traverses a rotary can 15 (i). After the substrate 1 is inverted by rolls 25 and 25, the soft magnetic layer and the vertically magnetized recording layer are formed successively on the opposite side of said side of the substrate 1 in the same method while the substrate traverses rotary cans 16 and 17 (ii), thus obtaining a recording material where vertically magnetized recording layers are provided on both sides.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing a magnetic recording medium.

In the perpendicular recording method, which has recently attracted attention as a magnetic recording method with excellent short wavelength recording characteristics, the development of media manufacturing technology has become important.

The perpendicular recording media currently used on a laboratory scale consists of forming a soft magnetic thin film such as permalloy on a non-magnetic substrate such as a plastic film, and depositing mainly Co,! : O
A so-called perpendicular recording layer containing r as a main component and having an axis of easy magnetization in the perpendicular direction is formed by a sputtering method.
A prototype disc with a double-sided configuration has also been produced, and intensive research is being conducted to improve its recording and reproducing characteristics. However, the technology for producing it on an industrial scale has not yet been established.

In view of this point, the present invention provides a method by which a large quantity of media having perpendicular recording layers on both sides can be continuously obtained.Examples thereof will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in which independent evaporation sources are provided for forming the soft magnetic layer and the perpendicular recording layer, and FIG. 2 shows the evaporation sources for the soft magnetic layer. Cases 3 and -7 are shown below, which have the excellent features described below. It is a point formed continuously.

As shown in FIG. 1, a flexible substrate 1 made of plastic or the like moves from a delivery shaft 18 along a first rotary can 14 and a second rotary can 15. As shown in FIG.

A soft magnetic layer, such as permalloy, is formed in the first opening 20 of the mask 24 that limits the incident angle while allowing heat to escape to the first rotating can 14 . Container 10. as evaporation source. Evaporation material 2. Although the electron beam heating type evaporation source is schematically shown as the electron source 6, the present invention is not limited to this, and any known thin film formation method such as thin film formation by sputtering may be used.

Next, when moving along the second rotating can 16, the evaporative material 3. Container 11. consisting of an electron source 7, e.g. Co-Cr
A perpendicular recording layer is formed in the apertures 21 using the evaporation source. Next, a soft magnetic layer is formed on the opposite surface of the substrate 1 with the openings 22 along the third rotary can 16, and while moving along the fourth rotary can 7, , a perpendicular recording layer is formed in the openings 23.

The evaporation sources are containers 12 and 13, respectively. Evaporation material 4,6° electron source 81. It is schematically shown by e. The substrate having perpendicular recording layers formed on both sides is thus rolled up by the winding shaft 1e.

The vacuum atmosphere and thin film formation method can be selected as appropriate, and a protective layer can be formed on the perpendicular recording layer as necessary.

26 is a free roller, and winding system elements such as an expander roll dancer roll are arranged as necessary.

Furthermore, when pre-treatment and post-treatment are required, it is natural to prepare an apparatus equipped with a glow treatment mechanism. FIG. 2 shows another embodiment of the present invention; It is simpler than the case. As shown in the figure,
The first rotary can 36 and the second rotary can 37 are arranged adjacently, and the first rotary can 36 and the second rotary can 3
7 is configured to rotate at substantially constant speed in opposite rotational directions (if the can diameter differs, the number of rotations will vary accordingly).

6,,-1 1st. An evaporation source for forming the soft magnetic layer is disposed approximately midway between the second rotary cans 36 and 37. This is container 30. Evaporation material 27. Although the electron source 33 is schematically shown, sputtering can also be used as in the previous embodiment. However, it is easy to control the film thickness, especially to ensure that the same film thickness is obtained on both sides of the substrate 26 (by making the openings 46° 46 formed by the masks 42, 41, 43 symmetrical and of the same area). Therefore, it is preferable to use an electron beam heating type evaporation source as the evaporation source rather than using sputtering.

The substrate 26, on which soft magnetic layers are formed on both sides using one evaporation source as described above, is transferred to a perpendicular recording layer using a vapor flow whose incident angle is limited by apertures 47 exposed from masks 41 and 40 in a rotating can 36. is formed. Thereafter, a second perpendicular recording layer is formed on the other soft magnetic layer using the openings 48 formed by masks 43 and 44 in the same manner. The evaporator 28.29 is often Co
-Or, containers 31, 32. An electron beam heated evaporation source schematically shown as an electron source 34 and 35 is used. Of course, this can also be done by sputtering. Delivery shaft 38. Winding shaft 39. Free roller 4.9.
Rolling elements such as expander rollers (not shown) are
The arrangement should be optimized in relation to mechanisms such as pre-processing and post-processing.

Using the apparatus shown in Fig. 2, an alloy of 80% Ni-20'% F was heated and evaporated with an electron beam of 10 kv16 microorganisms to form a permalloy layer of 1°6μ on a polyamide substrate (8μ−). , the incident angle is ±10″ in the 100 area, 0os
a%0r1e%f) alloy at 10kV.

At 3.3 wI (this is a refractory crucible with high thermal efficiency, it can be deposited with low power) to form a 0.4 μ Co Cr layer. The can temperature at this time is 80°
It is C. Also, the board winding speed is 1j5B/l1in.
It is.

As mentioned above, there is a 1.6μ pmalloy layer on both sides, a 0.4μ
Since the stress relationship is balanced even without special heat treatment, the stress relationship of the substrate with #l of μ CoCr layers (having an axis of easy magnetization in the perpendicular direction and a coercive force of y s o Oe) is balanced.
For example, even if you slit it to W width, it will curl 7.

recording and playback can be performed stably.

The Go-Cr layer is formed using a high-speed sputtering method.

We have confirmed the ion brating method and the electric field deposition method, but in order to use CO-Cr sputtering and permalloy electron beam evaporation together, the optimum operating vacuum degree is different from 8 X 10 Torr and I X 18 Torr or less, respectively. The equipment needed to be modified to accommodate the differential pressure.

In any case, when depositing on both sides individually as in the past, it is taken out into the atmosphere once, so there is an increase in dropouts due to contamination of dust, and strong curling causes wrinkles during transportation. However, in the embodiment shown in Figure 2, if the permalloy film thickness is the same in the longitudinal direction, curling can be completely prevented. It has the advantage of being able to

As described above, according to the present invention, a completely flat magnetic recording medium having perpendicular recording layers on both sides can be easily obtained on an industrial scale, and therefore has great industrial value.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention, and FIG. 2 shows another embodiment of the present invention, both of which are diagrams showing how a magnetic recording medium is manufactured. 1.26...Substrate, 2.3, 4, 5, 27, 2
8゜29... Evaporation material, 14, 15, 16, 17
,36.37... Rotating can, 24,40,4
1,42,43.44...Mask.

Claims (2)

[Claims] (1) A method for manufacturing a magnetic recording medium, characterized in that the step of forming perpendicular recording layers on both sides of a plastic substrate is performed continuously in the same vacuum system. (2) In the same vacuum system, a soft magnetic layer is formed on one surface of a plastic substrate that moves along two rotating cans with different rotational directions by the vapor flow from the first evaporation source, and then a soft magnetic layer is formed on it. A perpendicular recording layer is formed by the vapor flow from the second evaporation source, and then a soft magnetic layer is formed on the other surface of the substrate by the vapor flow from the first evaporation source, and then a soft magnetic layer is formed on the other surface of the substrate by the vapor flow from the first evaporation source. 19. The method of manufacturing a magnetic recording medium according to claim 18, wherein the perpendicular recording layer is formed by the vapor flow from the evaporation source of step 3.