JP2819214B2 - Disc and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art In a disk device used as a file device in an information processing system, a disk having a magnetic film formed on a non-magnetic disk is used as a recording medium. By the way, with the progress of downsizing of information processing apparatuses, the size of magnetic disks has also been reduced, and recently, magnetic disks having a small diameter of 1.8 inches to 1.6 inches and 1.3 inches have been put into practical use. .
The present invention relates to a disk effective for such a small-diameter disk and a method for manufacturing the disk.

[0002]

2. Description of the Related Art FIG. 7 is a view showing a sectional structure of a thin-film magnetic disk. Reference numeral 1 denotes a substrate made of a non-magnetic material such as aluminum or glass, and Cr or the like is sputtered as a base film 3 on a NiP plating layer 2 formed on the surface thereof.
Then, after a magnetic material such as CoCrTa or CoNiCr is sputtered to form a thin film magnetic film 4, carbon is sputtered as a protective film 5, and finally a lubricant 6 such as fomblin is used.
Is applied and dried to complete.

[0003] rotated at a high speed of the magnetic disk in the arrow a ₁ direction, in a state where the magnetic head 7 is floated by the wind, by a gap G, the recording / reproducing of information to the magnetic film 4 is performed.

FIG. 8 is a sectional view showing a conventional method of manufacturing a disk in the order of steps, which is also disclosed in Japanese Patent Application No. 3-336495 previously filed by the applicant of the present invention. In step (1), reference numeral 1 denotes a donut-shaped substrate made of a nonmagnetic material such as aluminum, which is formed in the same size as a magnetic disk to be manufactured. For example, 2.5
In the case of manufacturing a small-diameter magnetic disk having a diameter of 2.5 inches, the nonmagnetic disk 1 also has a diameter of 2.5 inches.

Then, in step (2), the non-magnetic disc 1
NiP plating base layer 2 is formed on both sides of
In (3), an abrasive tape is pressed against the surface of the rotating non-magnetic substrate to form fine texture grooves 8 in the circumferential direction.
To form

Next, in a step (4), a Cr layer 3 for improving the horizontal orientation of the Co alloy is formed on the texture grooves 8, and a Cr layer 3 is formed on the Cr layer 3 in the step (5). Is formed. On this magnetic film 4,
As in the step (6), a carbon film 5 is formed as a protective film, and finally a fluorine-based lubricating layer 6 is applied. Cr layer 3,
The thin film type magnetic film 4 and carbon film 5 are formed by a thin film technique such as sputtering.

The texture grooves 8 formed in the step (3)
This is for imparting magnetic anisotropy so that the electromagnetic conversion characteristics when recording / reproducing information is improved by the flying gap G formed in the rotation direction of the magnetic disk as shown in FIG.

Further, since the carbon film 5 also becomes uneven along the texture grooves 8, the magnetic head can be prevented from being attracted to the magnetic disk surface by the lubricant, and the friction between the magnetic head and the magnetic disk surface can be reduced. Becomes smaller.

[0009]

However, as described above, when the diameter of the magnetic disk is reduced to 1.89 inches or less due to the downsizing of the magnetic disk device, the thickness is also reduced to 0.1.
Since it is thinner than 635mm, it is difficult to texture the surface of the rotating disk by pressing the polishing tape on both sides to form fine grooves in the circumferential direction. In addition, when the diameter of the disk is small, handling becomes difficult, which is not suitable for mass production.

[0010]

[Table 1]

In the case of a magnetic disk having a diameter of 2.5 inches or more as shown in Table 1, recording / reproduction is performed with a conventional floating magnetic head. However, the magnetic head is gradually lowered to achieve a higher recording density. As a result, the texture grooves also tend to be miniaturized, and the necessity of the texture grooves has been questioned.

On the other hand, for a small-diameter magnetic disk of 1.89 inches or less, a contact-type magnetic head is used. Therefore, unlike the conventional case where recording / reproduction is performed with a gap in a floating state, magnetic anisotropy does not matter much. Rather, it has been pointed out that an error may occur at the time of recording / reproduction due to a minute defect due to the texture processing.

Further, in the case of a floating magnetic head, the magnetic head is pressed against the magnetic disk by a spring arm against the levitation force. The driving force of the spindle motor must be increased so that a large number of magnetic heads adhered to the magnetic disk surface can be peeled off from the magnetic disk surface by the spring force.

In order to prevent this, it is necessary to provide a texture groove so as to reduce the adhesive force. However, in the case of a contact type magnetic head, since it is in contact with a weak spring pressure even when the magnetic head is stationary, the adhesiveness is low. The problem is small, so that texture grooves for anti-sticking are not essential.

For the above reasons, the need for the conventional texture groove is small, but it is necessary to adapt the magnetic head element portion to the surface of the magnetic disk before operation, including the perpendicular magnetic recording type magnetic disk. That is, it is necessary to reliably contact the magnetic pole portion with the magnetic disk surface so that the electromagnetic conversion efficiency is improved.

For this purpose, it is necessary to perform a process of rotating the magnetic disk at a higher speed than during recording / reproducing before the operation and abrasion of the magnetic head element portion until the magnetic pole portion of the magnetic head contacts the magnetic disk surface without fail. is there. In order to perform this process smoothly, it is desirable that the surface of the protective film of the magnetic disk is rough to some extent. Also, the tip of the magnetic pole may become dirty during operation,
Even when dust is attached, if the magnetic disk surface is rough,
It is easily removed.

The technical object of the present invention is to realize a magnetic disk having a rough protective film surface without performing texture processing by a conventional method, focusing on such a problem.

[0018]

FIG. 1 is a sectional view for explaining the basic principle of a disk and a method of manufacturing the same according to the present invention. A plurality of targets A, B and C are provided corresponding to a substrate 1 on which sputtering is performed. , D are provided. And
The sputtered particles c and d scattered from the targets C and D in the direction perpendicular to the substrate 1 have a small particle size, and the targets A and B
Sputtered particles a scattered obliquely to the substrate 1 from
b has a large particle size.

According to the first aspect of the present invention, the protective film 5 formed on the thin film type magnetic film of the disk is formed of sputtered particles a (b) and c (d) having different particle diameters. is there.

According to a second aspect of the present invention, the protective film 5 formed on the thin film type magnetic film of the disk is formed of sputtered particles a (b) and c (d) having different particle sizes. In this configuration, particles a (b) having a large particle diameter are obliquely attached.

According to a third aspect of the present invention, when the protective film 5 is formed on the thin film type magnetic film of the disk, at least one target is used on one side of the substrate in one sputtering apparatus; This is a method of performing sputtering by changing the sputtering power. That is, when there are a plurality of targets A, B, C, and D corresponding to the substrate 1, the sputter power is changed according to the target, and when a single target is used, the sputter power is changed temporally.

According to a fourth aspect of the present invention, when a protective film is formed on a thin-film magnetic film of a disk, a plurality of targets having different compositions as shown in FIG. This is a method of manufacturing a disk for performing sputtering on the substrate 1 by using the method.

[0023]

According to the first aspect of the present invention, the protective film is composed of the sputtered particles a (b) and c (d) having different particle diameters.
The surface state of the protective film 5 is rougher than that of a protective film formed by depositing only sputtered particles having the same particle diameter.

As described in claim 2, the protective film 5 is composed of sputtered particles a (b) and c (d) having different particle diameters, and the particles c (d) having a small particle diameter adhere from the vertical direction. Whereas
When the particles a (b) having a large particle diameter are obliquely adhered, the protective film 5 having a rougher surface condition than the case where the sputtered particles having different sizes are simply deposited as claimed in claim 1.
Is obtained.

According to the third aspect, when there are a plurality of targets A, B, C and D corresponding to the substrate 1, for example, by changing the sputtering power of the targets A and B and the targets C and D, By changing the particle size of the sputtered particles generated from the targets A and B and the sputtered particles generated from the targets C and D, the particles a (b) having a large particle size and the particles c (d) having a small particle size can be attached to the substrate 1. Therefore, the surface of the protective film can be roughened simultaneously with the formation of the protective film.

Alternatively, when a single target is used, the surface of the protective film can be roughened by controlling the particle size of the sputtered particles to be small at first, and finally controlling the particle size of the sputtered particles to be large. Become.

According to a fourth aspect of the present invention, in a single sputtering apparatus, when a protective film is formed using a plurality of targets having different compositions, sputtered particles having a plurality of types of particle diameters can be sputtered simultaneously with the same power. It adheres and the surface of the protective film becomes rough.

[0028]

EXAMPLES Next, practical examples of how the disk and the method of manufacturing the same according to the present invention are embodied will be described with reference to examples. FIG. 2 is a front view showing a first embodiment of the target arrangement, and a longitudinal sectional view in a state where sputtering is performed by the same target arrangement. (A) As shown in the figure, a target A is arranged on the upper side, a target B is arranged on the lower side, and targets C and D are arranged in the middle. Such targets A to D are provided on both sides of the substrate 1 as shown in FIG.

The targets A to D are all surrounded by electrodes 9 except for the substrate 1 side.
By applying power to the target, the sputtered particles generated from each of the targets A to D scatter toward the substrate 1 and are deposited. When the power of the power applied to the upper and lower targets A and B is made larger than the power of the power applied to the intermediate targets C and D, the power is generated from the intermediate targets C and D as shown in FIG. Sputter particles a and b generated from upper and lower targets A and B are larger than sputter particles c and d.

By selecting the power of the power supply, the large-diameter sputter particles a and b can be reduced to the small-diameter sputter particles c and d by 2 to 2.
It can be set to about three times. In this embodiment, when the power of the targets A and B was set to 15 kW and the power of the targets C and D was set to 1 kW in an Ar gas atmosphere of about 10 mTorr, the large-diameter sputtered particles a and b became small It was about twice as large as the particles c and d. Carbon was used as targets A to D, but zirconium oxide (ZrO ₂ )
Is also effective.

Further, the sputtered particles generated from the intermediate targets C and D arrive from the direction substantially perpendicular to the substrate 1, while the sputtered particles generated from the upper and lower targets A and B are oblique to the substrate 1. It is arranged so that it comes from the direction.

Therefore, as shown in FIG. 3, sputtered particles c and d having a small particle size are formed on the magnetic film 4 of the substrate 1.
Is attached vertically on the lower sputtered particles, whereas sputter particles a and b having a larger particle diameter are adhered obliquely on the lower sputtered particles. As a result, the surface state of the protective film 5 does not become flat, but becomes uneven as shown in the figure.

Next, the substrate 1 shown in FIG. 1 may be a single substrate, but it is inferior in productivity to face several targets A to D to the single substrate. Therefore, it is efficient to support, for example, ten or more substrates in the same plane by a holder and form protective films on many substrates at once. Therefore, FIG. 2B shows an embodiment in which four targets A to D are arranged on both sides of a plurality of substrates 1.

FIG. 4 is a front view showing various embodiments of the target arrangement. (1) The figure is a rectangular annular target, and targets D, C, and A are arranged in this order from the inside so as to surround the target B at the center.

In this arrangement, sputtered particles generated from the targets C and D scatter in a direction substantially perpendicular to the substrate surface, and sputtered particles generated from the central target B and the outermost substrate A are separated from the substrate surface. Flying obliquely. The power of the applied power source makes the power of the targets B and A at the center and the outermost periphery larger than those of the targets C and D. The target shape may be a perfect circle or an ellipse.

(2) The figure is the same as the embodiment of FIG. (3) The figure shows an example in which the horizontally elongated strip-shaped targets A and B are arranged in parallel so as to sandwich the horizontally elongated strip-shaped targets C and D. On the other hand, FIG. 4D shows an example in which vertically long strip-shaped targets C and D are sandwiched between vertically long strip-shaped targets A and B.

In the case of FIGS. 3 and 4, if the power supply power applied to the inner targets C and D is reduced and the power supply power applied to the outer targets A and B is increased,
Since the size of the sputtered particles can be changed, and the sputtered particles having a large particle size fly obliquely from the outside, and the sputtered particles having a small particle size fly from a direction perpendicular to the substrate, the present invention provides a method according to claim 4. The surface of the protective film can be efficiently and uniformly roughened.

(5) FIG. 5 shows an example in which four targets A to D are arranged in the shape of a cross, and (6) FIG. 6 shows four equilateral triangle targets A to D arranged so as to form an x-shaped boundary. It is an example. In these embodiments, if the power supply power of the targets A and B is increased and the power supply powers of the other targets C and D are reduced, the protective film can be formed with sputtered particles having different particle diameters. As described above, a relatively rough protective surface can be realized.

In the above embodiment, all the targets A to D
Are identical, but FIG. 5 shows the outer targets A,
In this example, titanium (Ti) is used as B, and carbon (C) is used as targets C and D inside. Carbon has an atomic radius of 0.71 mm, whereas titanium has a radius of 1.47 mm.
Therefore, the sputtered particles having different particle diameters can be deposited without changing the power supply power of the targets A and B and the targets C and D, and the rough surface state as described in claim 1 can be realized.

Moreover, when the titanium targets A and B are arranged outside the carbon targets C and D, the carbon particles having a small particle size fly from the direction perpendicular to the substrate surface, whereas the titanium particles having a large particle size Since it comes obliquely, an excellent rough surface condition as described in claim 2 can be easily obtained.

The inner carbon targets C and D
When the power supply power of the titanium targets C and D outside the power supply power is increased, the difference between the carbon particle diameter and the titanium particle diameter is further increased, so that a more excellent roughened surface state can be realized.

In the illustrated example, the targets A, B, C and D are spaced apart from each other so that the electrodes 9 of adjacent targets are not short-circuited. Integrating via each other facilitates arrangement and support of each target. In the above embodiment,
Although there are four targets, five or more targets may be used, and the arrangement of each target may be modified in various ways.

As described in claim 3, a single target may be provided for one surface of the substrate. In this case, the surface can be roughened by first reducing the sputter power and forming a film with fine sputter particles, then increasing the sputter power and attaching large sputter particles.

The sputtering apparatus can be applied to an in-line type in which a disk moves between left and right targets, but is particularly effective for a batch type apparatus called a Varian type.

In FIG. 6, reference numeral 1a denotes a large-diameter substrate of, for example, 8 inches. A magnetic film is formed on such a large-diameter substrate 1a, and a protective film 5 is formed thereon by the method of the present invention. Then, after completing the large-diameter magnetic disk, a small-diameter substrate as shown by 1b can be extracted to obtain a small-diameter magnetic disk such as 1.89 inches. In this case, the small-diameter substrate 1b
It is necessary that the difference W between the inner and outer circumferences of the large-diameter substrate 1a is larger than the outer diameter D.

[0046]

According to the first aspect of the present invention, when sputtered particles having different particle diameters are deposited, the surface of the protective film becomes rough, and the sliding surface between the head and the disk surface is easily adjusted so that the head fits the disk surface. By abrasion, the tip of the magnetic pole can be reliably brought into contact with the disk surface. Therefore, it is effective for a small disk that does not require texture processing.

Further, as in claim 2, the protective film has a structure in which the particles c having a small particle diameter are attached from a vertical direction, while the particles a (b) having a large particle diameter are attached from an oblique direction. Then, the surface state of the protective film 5 becomes rougher.

When forming the protective film 5, a plurality of targets A, B, C, D corresponding to the substrate 1 are formed.
By changing the sputtering power of the target, the particle size of the sputter particles generated from each target is changed, and the particles a (b) having a large particle size and the particles having a small particle size are changed.
c (d) can be adhered to the substrate 1, and the surface of the protective film can be roughened in the step of forming the protective film without adding a special step. Alternatively, when the target is a single target, if the sputtering is first performed with fine particles and then the sputtering is performed with coarse particles, the surface of the protective film becomes rough.

According to a fourth aspect of the present invention, in a single sputtering apparatus, when a protective film is formed using a plurality of targets having different compositions, sputtered particles having a plurality of types of particle diameters can be sputtered simultaneously with the same power. Since the protective film adheres and has a rough surface, control is facilitated.

Further, according to the present invention, the surface of the substrate can be roughened without performing texture processing and without adding a special process, which is extremely effective in reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a basic principle of a disk and a method of manufacturing the disk according to the present invention.

FIG. 2 is a front view showing a first embodiment of the target arrangement, and a longitudinal sectional view in a state where sputtering is performed with the same target arrangement.

FIG. 3 is a cross-sectional view showing a protective film of the present invention formed by sputtering.

FIG. 4 is a front view showing various embodiments of a target arrangement.

FIG. 5 is a front view showing a combination example of a plurality of targets having different compositions.

FIG. 6 is a front view showing an example of manufacturing a plurality of small-diameter magnetic disks from a large-diameter magnetic disk on which a protective film is formed.

FIG. 7 is a diagram showing a cross-sectional structure of a conventional thin-film magnetic disk.

FIG. 8 is a sectional view showing a conventional disk manufacturing method in the order of steps.

Claims (4)

(57) [Claims] 1. A disk according to claim 1, wherein the protective film formed on the magnetic film of the disk comprises a sputtered film in which sputtered particles whose particle diameters are controlled to two or more are mixed and deposited. 2. The method according to claim 1, wherein the protective film formed on the magnetic film of the disk comprises a sputtered film on which sputtered particles having different particle diameters are deposited, and particles having a large particle diameter adhere obliquely. And disc. 3. A method according to claim 1, wherein a protective film is formed on the magnetic film of the disk .
Place the target and sputter with the first sputter power
After that, the second sputtering power larger than the first sputtering power is used.
A method for manufacturing a disk , comprising sputtering with a putter power . 4. A method for forming a protective film on a magnetic film of a disk, wherein the sputtering is performed on the substrate by using a plurality of targets having different compositions in one sputtering apparatus. Disc manufacturing method.