JPS61208624A - Manufacture of both side recording type magnetic recording medium and both side simultaneous sputtering device - Google Patents

Abstract

PURPOSE:To improve the recording and reproducing characteristic by evacuating air in a vacuum tank, sealing an inactive gas and impressing a negative voltage to a target so as to form a magnetic thin film at the same time at both relative position of both front and rear sides of a base. CONSTITUTION:After the vacuum state in a vacuum tank 30 is adjusted to a predetermined state, when a prescribed negative voltage is applied to the 1st target and the 2nd target, glow discharge takes place between the 1st target 1 and the 1st opposite electrode 3 and between the 2nd target 2 and the 2nd opposite electrode 4 and the inactive gas sealed in the vacuum tank 30 is ionized. The evaporated substance passes through a throughhole 8 made to the opposite electrodes 3, 4 and the plasma produced by the glow discharge, reaches a base 7 and is adhered to both the front and rear sides of the base 7 at the same time. In carrying the base 7 by driving a winding roller 6, the thin film of the evaporated substance is formed onto both the front and rear sides of the base 7. Thus, a stable head touch is obtained and an excellent recording and reproducing characteristic is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a double-sided recording type magnetic recording medium in which magnetic layers are formed on both the front and back sides of a substrate, such as a single-sided recording type floppy disk, and a double-sided recording type magnetic recording medium. The present invention relates to a double-sided simultaneous sputtering apparatus suitable for manufacturing magnetic recording media.

[Conventional technology]

FIG. 11 shows an example of a conventionally known manufacturing apparatus for this type of magnetic recording medium.

In this figure, 30 is a vacuum chamber, 31 is a first can roller, 32 is a second can roller, 33 is a first target disposed below the first can roller 31,
34 is a second target placed above the second can roller 32;

35 is a holding roller disposed outside the first canning roller 31; 36 is a take-up roller disposed outside the second canning roller 32; 37 is a roller wound around the holding roller 35; It is a long tape-shaped substrate.

The vacuum chamber 30 is provided with a vacuum pump 38 for discharging air within the vacuum chamber, and an inert gas supply port 40 connected to an inert gas, for example, an argon gas cylinder (not shown) through a pipe 39. It is being

41 is a valve installed in the pipe 39.

The first can roller 31 and the second can roller 32 constitute an anode facing the targets 33 and 34.

The first target 33 and the second target 34
is a substance to be deposited on the substrate 37.

For example, if it is a magnetic recording medium for perpendicular magnetic recording, it is G.

-Cr alloy, and constitutes a cathode facing the first can roller 31 and the second can roller 32.

The substrate 37 is made of a synthetic resin sheet with excellent heat resistance, such as a polyimide sheet, and as shown in FIG. It is wound around the upper half circumference, and then around the upper half circumference of the second can roller 32, and its leading edge is wound around the take-up roller 36.

This winding roller 36 is connected to a drive motor (not shown), and pulls out the substrate 37 from the holding roller 35 at a required speed, and winds the double-sided magnetic recording medium on which the magnetic layer is formed into a roll. It is supposed to be taken.

The conventional double-sided simultaneous sputtering apparatus described above has three vacuum pumps.
8 to discharge the air in the vacuum chamber, and then inert gas is supplied from the inert gas supply port 40 to adjust the degree of vacuum in the vacuum chamber 30 to a predetermined value.

When a predetermined negative voltage is applied to the first target 33 and the second target 34, the voltage between the first can roller 31 and the first target 33 and the second can roller 3
A glow discharge occurs between 2 and the second target 34,
Inert gas ionizes. Subsequently, the positive ions are accelerated by a strong electric field in the dark part of the cathode, collide with the first target 33 and the second target 34, and knock out atoms or molecules of the substance constituting these targets 33 and 34. These evaporated substances pass through the plasma generated by the glow discharge and reach the substrate 37.
adheres to the surface of Therefore, by driving the take-up roller 36 to transfer the substrate 37, a thin film of the vapor deposited substance is formed on both the front and back surfaces of the f+ temporary 37, in the case of this embodiment, Co--C.
A thin film of r alloy can be formed.

Next, FIG. 12 shows another example of a conventionally known manufacturing apparatus for this type of magnetic recording medium.

In this figure, 42 is a counter electrode, 43 is a target,
44 indicates the board, and 51st! Components similar to those shown in FIG. 1 are designated by the same reference numerals.

The counter electrode 42 constitutes an anode facing the target 43, similar to the can rollers 31 and 32 in the first conventional example, and is formed in a flat plate shape having approximately the same area as a substrate 44, which will be described in detail later. .

At both left and right ends of the substrate 44, a rotating shaft 44a extending in a direction parallel to the counter electrode 42 and the target 43;
44b are arranged in series, and by rotationally driving these rotating shafts 44a and 44b.

The facing electrode 42 and the surface facing the target 43 can be continuously reversed.

The double-sided sputtering apparatus of the second conventional example, like the south side sputtering apparatus of the first conventional example, adjusts the conditions inside the vacuum chamber 30 to apply a negative voltage to the target 43 and drives the one-rotation shafts 44a and 44b. By rotating the substrate 44 in this manner, a thin film of the vapor deposition material can be formed on both the front and back surfaces of the substrate 44. - [Problems with the prior art] Among the conventional double-sided sputtering apparatuses described above, the first conventional double-sided sputtering apparatus can use a long tape-shaped substrate as a substrate, so it has high productivity and can perform double-sided recording. It is suitable for manufacturing molded magnetic recording media, etc. However, the second double-sided sputter portion is composed of a first sputter portion constituted by the first can roller 31 and the first target 33, and a second sputter portion constituted by the second can roller 32 and the second target 34. Since the sputtered portions are formed at different positions, thin films cannot be formed on both the front and back surfaces of the same portion of the substrate 37 at the same time. That is, vapor deposition is first performed on the back surface of the substrate 37 in a first sputtering portion composed of the first can roller 31 and the first target 33 located upstream of the substrate 37 wound up by the first take-up roller 36. The material is then deposited on the surface of the substrate 37 in a second sputtering section composed of the second can roller 32 and the first target 34 . In the double-sided sputtering apparatus of the first conventional example, the substrate 37 is brought into close contact with the outer circumferential surface of the cylindrical can roller 31, 32, and the deposition substance is deposited on the surface of the cylindrical can roller 31, 32, thereby forming a thin film only on one side of the substrate. This is to prevent warping and wrinkles that would otherwise occur. however.

Warpage and wrinkles that occur when a thin film is formed only on one side of a substrate cannot be completely prevented even by such measures, and in particular, in the case of the first conventional example above, after forming a thin film on one side, , a thin film was also formed on the back side, so
There was a problem that warping and wrinkles were more likely to occur. As a result, the product yield is poor and productivity is low, and a magnetic disk taken out from a warped original sheet experiences large vibrations during one revolution, resulting in the problem that recorded and reproduced signals are likely to deteriorate. .

Furthermore, among the conventional double-sided sputtering apparatuses described above, the second conventional double-sided sputtering apparatus rotates the substrate 44 so as to turn it upside down, so that the growth of the thin film becomes intermittent and the direction of crystal growth is disturbed. This phenomenon occurs. This problem becomes particularly problematic when the method is applied to the manufacture of floppy disks for perpendicular magnetic recording, in which it is preferable to align the crystal growth direction perpendicular to the substrate.

[Means for solving problems]

In order to solve the problems of the prior art and provide a double-sided magnetic recording medium that is free from single repeats and wrinkles, the present invention aims to provide a first target and a second target made of magnetic material facing each other in a vacuum chamber. provided between these two targets, at least one counter electrode having a through hole capable of penetrating the target particles ejected from the target, and a substrate provided close to the counter electrode; After evacuating the air in the vacuum chamber and filling it with an inert gas, a negative voltage is applied to the target to simultaneously form magnetic thin films at mutually symmetrical positions on both the front and back surfaces of the substrate, and A first target and a second target are disposed facing each other in a vacuum chamber, a substrate is interposed between these two targets, and a space between the first target and the substrate and the second target is provided. A counter electrode is provided between at least one of the target and the substrate, the counter electrode having a through hole through which the vapor deposition material ejected from the target can penetrate. .

〔Example〕

Examples of the present invention will be described below.

FIG. 1 is a sectional view showing a first example of implementation of a double-sided simultaneous sputtering apparatus according to the present invention, in which 1 indicates a first target;
2 is the second target, 3 is the first counter electrode, 4 is the second
, 5 is a holding roller, 6 is a take-up roller, 7 is a substrate which is wound around the holding roller 5 in a roll shape, and whose drawn end is wound around the take-up roller; The same reference numerals are used for the same members as shown in FIG.

The first target l and the second target 2 are
They are formed of the material to be formed on the surface of the substrate 7, and are placed opposite each other inside the vacuum chamber 30.

The first counter electrode 3 and the second counter electrode 4 are 1
For example, it is formed of a good conductor such as copper, and the first
A through hole 8 is provided through which atoms ejected from the target 1 and the second target 2 can pass. The shape, number 1 distribution density, and arrangement of the through holes 8 opened in the first counter electrode 3 and the second counter electrode 4 are determined by the type of substance to be vapor-deposited, the type of substrate on which the thin film is formed, and the necessary It can be arbitrarily designed depending on the thickness of the thin film to be used. For example, as shown in FIG. 2, the tortoise-shell-shaped through holes 8a may be opened vertically and horizontally, or as shown in FIG. You can also place them at equal intervals.

Furthermore, as shown in FIG. 4, a small diameter round through hole 8e
IJ: You can place them at equal intervals above, below, left and right.

As shown in FIG. 5, one or more large diameter round holes 8d
The first opposing electrode 3 and the second opposing electrode 4, which may have an opening, are arranged between the first target 1 and the second target 2 in parallel with each other.

The holding roller 5 is arranged on one side of the counter electrodes 3 and 4, and the winding roller 6 is arranged on one side of the counter electrodes 3 and 4.
, 4. A take-up roller 6, which is inserted through the center of the opposing electrodes 3 and 4, is connected to a drive motor (not shown) at the lead-out end 7a of the substrate 7.
The tape is wound up while applying a constant tension to the pull-out end 7a.

The double-sided simultaneous sputtering apparatus of the first embodiment has a vacuum chamber 30
After adjusting the vacuum state inside to a predetermined state, a predetermined negative voltage is applied to the first target 1 and the second target 2.

Between the first target 1 and the first counter electrode 3.

A glow discharge occurs between the second target 3 and the second counter electrode 4, and the inert gas sealed in the vacuum chamber 30 is ionized. As a result, these positive ions are accelerated by the strong electric field in the dark part of the cathode.

These evaporated substances collide with the first target 1 and the second target 2 and knock out atoms or molecules of substances constituting these targets 1.2. It reaches the substrate 7 through the through hole 8 formed in the substrate 7, and is attached to both the front and back surfaces of the substrate 7 at the same time. Therefore, by driving the first take-up roller 6 and transporting the substrate 7, a thin film of the vapor deposition material can be formed on both the front and back surfaces of the substrate 7. in this case,
After the vapor deposition substance passes through the counter electrode 413.4, it passes through the counter electrode 3.
．． 4, so it goes around to the back side of board 7.

A uniform thin film is formed.

In the case of the double-sided simultaneous sputtering apparatus of the first embodiment.

Since thin films can be formed simultaneously on both the front and back surfaces of the same portion of the substrate 7, wrinkles and warpage do not occur in the substrate.

Hereinafter, a method for manufacturing a double-sided recording type perpendicular magnetic recording magnetic recording medium using the double-sided simultaneous sputtering apparatus of the first embodiment will be described.

First, as the targets 1 and 2, targets made of Go-Cr alloy are installed in the vacuum chamber 30, and as the substrate 7, a polyimide sheet is placed on the holding roller 51 and the take-up roller 6.
Wind it around.

Next, the vacuum pump 38 is operated to exhaust the air in the vacuum chamber 30, and then the valve 41 of the inert gas supply port 40 is opened to supply inert gas of about 10-'' torr to the vacuum chamber 3.
Supply within 0.

Subsequently, a negative voltage of 2 to 5 kV is applied to the target 1.2, and between the first target 1 and the first counter electrode 3 and between the second target 2 and the second counter electrode 4. Causes glow discharge (plasma).

At such times, positive ions in the plasma are accelerated by the strong magnetic field in the dark part of the cathode and collide with targets 1 and 2, causing Co
-Cr molecules are ejected, pass through the plasma and the counter electrodes 3 and 4, and are deposited on both the front and back surfaces of the substrate 7 at the same time. With this, the 61st! As shown in I, a thin layer rs11.12 of Co--Cr alloy is formed on both the front and back surfaces of the substrate 7.

The magnetic recording medium 13 in which the Go-Cr alloy thin films 11 and 12 are formed on both the front and back surfaces of the substrate in this manner is stored in a vacuum chamber 3.
The magnetic disk 14 is taken out from scratch, passed through a suitable media punching device, and formed into a magnetic disk 14 of a desired shape.

As shown in FIG. 7, the magnetic disk 14 is formed into a bag shape using a vinyl chloride sheet or the like.

It is rotatably housed in a jacket 17 having a spindle insertion hole 15 at the center and a head insertion hole 16 at its outer periphery, thereby forming a floppy disk for perpendicular magnetic recording.

In the above embodiment, two opposing electrodes 3.4 are arranged in parallel between the targets 1.2, and the lead end 7a of the substrate 7 is inserted between these two opposing electrodes 3, 4. As shown in FIG. 8, one counter electrode 10 formed in exactly the same manner as the counter electrode 3 (4) is provided between two targets 1.2, and this The lead end 7a of the substrate 7 may also be arranged along the electrode 10. In this case as well, thin films can be simultaneously formed on both the front and back surfaces of the same portion of the substrate 7, as in the simultaneous open-face sputtering apparatus of the first embodiment.

Further, in the above embodiment, a long tape-like substrate is used as the substrate, and a thin film is continuously formed on both the front and back surfaces of the substrate while being wound up with a take-up roller. However, as shown in FIG. 9, two opposing electrodes 20.
21, a substrate 22 is fixed between them, and this fixed substrate 2
It is also possible to form thin films on both the front and back surfaces of 2.

Furthermore, as shown in FIG. 10, two targets 1,
Between 2 and 2, the counter voltage [! One opposing electrode 23 formed in exactly the same manner as 3(4) is provided, and this opposing ffi electrode 23
The substrate 22 can also be fixed to.

In this case as well, thin films can be formed on both the front and back surfaces of the substrate 22 at the same time, similar to the double-sided simultaneous sputtering apparatus of the third embodiment.

〔Effect of the invention〕

As explained above, the simultaneous open-face sputtering apparatus of the present invention can deposit thin films on the front and back surfaces of a substrate at the same time. Never, therefore,
Product yield is good and productivity is high, and magnetic recording media manufactured using this double-sided simultaneous sputtering device are free from warping.

A floppy disk stamped from this disk does not vibrate when driven one revolution, provides stable head touch, and provides excellent recording and reproducing characteristics.

[Brief explanation of drawings]

1111 is a sectional view of a double-sided simultaneous sputtering apparatus showing the first embodiment of the present invention, FIGS. 2 to 5 are plan views of a counter electrode applied to the open-sided simultaneous sputtering apparatus of FIG. 1, and FIG. 6 is a cross-sectional view of a magnetic recording medium manufactured by the double-sided simultaneous sputtering apparatus of the first embodiment, FIG. 7 is a perspective view showing an example of a floppy disk, and FIG. 9 is a cross-sectional view of a double-sided simultaneous sputtering apparatus showing a third embodiment of the present invention, and FIG. 10 is a sectional view of a double-sided simultaneous sputtering apparatus showing a fourth embodiment of the present invention. 11 is a sectional view showing an example of a conventionally known double-sided sputtering apparatus, and FIG. 12 is a sectional view showing another example of a conventionally known double-sided sputtering apparatus. 1: first target, 2: second target. 3: first counter electrode, 4: second counter electrode, 5: holding roller, 61 take-up roller, 7: substrate, 30: vacuum chamber, 38
:Vacuum pump, 40:Inert gas supply 0.41:Valve Figure 1 I:Important target 8:Through hole 2;$2
t>9-) fvk-"-Vacuum pump 3: *tt> Counter electrode 4°2 non-5 colors";O-ra 6:@defeating roller?Two unit rejection Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. A first target and a second target made of a magnetic material are provided facing each other in a vacuum chamber, and a vapor deposition material ejected from the target is passed through the gap between these two targets. At least one counter electrode with a possible through-hole is provided, a substrate is provided adjacent to the counter electrode, and after the air in the vacuum chamber is evacuated and an inert gas is filled, the target is A method for manufacturing a double-sided recording film type magnetic recording medium, characterized in that a voltage is applied to simultaneously form magnetic thin films at mutually symmetrical positions on both the front and back sides of the substrate. 2. A first target and a second target are disposed facing each other in a vacuum chamber, a substrate is interposed between these two targets, and the space between the first target and the substrate and the second target is Double-sided simultaneous sputtering characterized in that a counter electrode having a through hole through which a vapor deposition material ejected from the target can penetrate is provided on at least one side between the second target and the substrate. Device.