JPH05258291A - Magnetic disc and its production - Google Patents

Abstract

PURPOSE:To enhance the durability of a magnetic disc and to increase recording density. CONSTITUTION:Protrusions 5 are formed on the surface of a substrate 1 with a wear resistant material different from the material of the substrate 1 so that the height of the protrusions 5 is made larger than that of a part on which a recording layer 2 exists. The resulting magnetic disc is slid on a magnetic head through the tops of the protrusions 5. The protrusions 5 are concentrically formed in a prescribed width and pitch or insularly formed at prescribed intervals. A protective layer 3 and a lubricative layer 4 are formed on at least the recording layer 2. The protective layer 3 on the protrusions 5 can be omitted. The durability of the parts of the disc slid on the head is enhanced and the service life is prolonged. Action under a small floating height or in a contact state is enabled and recording density is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device used in an information processing device such as a computer or a workstation, and more particularly to a magnetic disk used in a magnetic disk device having a dramatically high recording density and a method for manufacturing the same. It is a thing.

[0002]

2. Description of the Related Art A magnetic disk device is widely used as a large-capacity information storage device. However, the amount of information handled increases year by year, and the space for storing the information is narrowed. Increasing capacity is progressing at the same time.
A conventional magnetic disk (hereinafter abbreviated as a disk) is a method of recording / reproducing using a magnetic head (hereinafter abbreviated as a head) that is levitated by air resistance on a disk that rotates at a high speed. The reduction of the flying height was an essential matter. However, if the flying height is lowered to the utmost limit, the head and the disk are almost in contact with each other, and the head is in a state of moving at a relatively high speed. In the case of such continuous sliding, the recording layer formed on the disk surface is deteriorated or destroyed by heat or impact generated by the sliding, which causes an error, and in extreme cases, causes a crash.

For this reason, there is a limit to reducing the flying height of the head, which has been an obstacle to improving the recording density. Increasing the sliding reliability of the magnetic disk is an important technology for improving the recording density for the above reasons.
Various proposals have been made in the past. In particular, most of them cover the surface of the recording layer with a specific protective layer or a protective layer and a lubricating layer. For example, as described in Japanese Patent Application Laid-Open No. 1-317227, the material for the protective layer is specified or specified. Kaihei
There is an example in which the surface shape of the protective film is devised as disclosed in 1-243229. Of course, these have the effect of improving the sliding reliability of the magnetic disk, but in order to obtain sufficient durability, the thickness of the protective layer must be large to some extent, and the gap between the head and the recording layer is always the same as the protective layer. It has the drawback of being separated by the thickness. Moreover, this thickness must be a certain thickness or more so as not to reach the recording layer even if the protective layer is worn to some extent. Further, although these proposals can reduce the sliding that can be placed on a CSS (contact start stop) discrete disc at the time of starting and stopping the disc device, the head and the disc are always in contact with each other as described above. In a certain operation mode, the protective film was worn out and immediately crashed, which was insufficient.

Further, there is a magnetic disk (referred to as a discrete disk) in which a recording layer is formed by filling a magnetic layer in a groove formed by etching a non-magnetic substrate such as glass in order to increase the recording density. Are known.
This type of disk is promising for high-density recording because it can effectively suppress magnetic influence between tracks, that is, crosstalk, even if the recording tracks are sufficiently small. However, the surface that constitutes the edge of the groove and on which the head slides in opposition is formed of the substrate material left when the substrate is etched, so even if a protective film is formed on it, sufficient durability is not obtained. Absent. Since aiming at high-density recording, there is a limit to how thick the protective film can be made, and even if it is thin, sufficient durability is required. Incidentally, as one related to this type of discrete type disc, for example, Japanese Unexamined Patent Publication (Kokai) No. 2-201731 (where the surface facing the head is roughened to an appropriate roughness, C
(Which reduces sticking of the head during SS).

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and in particular, the durability of the disk against continuous sliding of the head and the disk is remarkably improved, and (EN) A magnetic disk capable of improving the life of the magnetic disk in a low flying state, and as a result, dramatically improving the recording density, and a manufacturing method thereof.

[0006]

In order to achieve the above object, a first feature of the present invention is a disc in which a sliding portion and a recording portion of the disc which come into contact with a head are separated from each other.
A hill-shaped structure (abbreviated as a hill) that also serves as a partition and a sliding portion is made of a non-magnetic material having high wear resistance different from that of the substrate, and the second feature is that the sliding portion is slightly higher than the recording portion. By doing so, the recording unit and the head do not substantially contact,
A third feature is that both the sliding portion and the recording portion are covered with at least one of the protective film and the lubricating film. The specific structure will be described with reference to FIGS.

(1) Structure of Desk FIG. 1 shows a cross-sectional structure of a typical disk of the present invention, and its features will be described below. In the figure, the disk 20 has a structure in which a recording layer 2, a protective layer 3, and a lubricating layer 4 are laminated on a non-magnetic substrate 1. The non-magnetic substrate 1 is made of a material having a uniform height in advance. A hill 5 made of a different non-magnetic material having high abrasion resistance is provided, and the recording layer 2 is not formed in this portion. The upper surface of the recording layer 2 is lower than the height of the upper surface of the hill 5 by a certain dimension.
The protective layer 3 and the lubricating layer 4 are uniformly provided on the entire surface of the disk substrate, and as a result, a portion of the recording layer 2 is recessed from the upper surface of the magnetic disk disk. The depth of this recess determines the length of the gap between the head and the recording layer during recording / reproduction, so it must be set carefully. Specifically 10
If the depth is deeper than this, the gap becomes too long and the recording density decreases, and if it is shallow, the roughness of the head and the roughness of the disk substrate may cause contact with the head even at the recording layer. Therefore, the effect of the present invention is lost.

FIG. 2 is a sectional view showing another example of the structure of the disc 20 of the present invention. In this case, the recording layer 2 has a two-layer structure of an underlayer 6 and a recording layer 2. FIG. 3 is a cross-sectional view showing a further different configuration example of the disc 20 of the present invention,
The root portion of the hill pattern 5 in FIG. 2 extends to the groove portion where the recording layer 2 is formed and is continuous, and the recording layer 2 is formed thereon with the underlying layer 6 interposed therebetween. Figure 4
3 is a cross-sectional view showing a further different configuration example of the disk 20 of the present invention, which has a configuration in which the protective layer 3 provided on the hill pattern 5 of FIG. 2 is removed, and the hill 5 is directly lubricated. Layer 4 has been formed. The depth of the recording layer 2 is the same as that in FIG. 1 in any of FIGS. 2, 3, and 4.

FIG. 5 is a fragmentary plan view of a disk 20 showing an example of the structure of the hill pattern 5 used in the present invention, which is an example of concentric circles formed in the circumferential direction. When the hill pattern 5 is formed in this way, there is also an effect of improving the characteristics of the recording layer 2. That is, increasing the number of recording tracks is one method of improving the recording density, but in the case of a recording layer continuously provided in the radial direction, a certain distance or more is set in order to prevent interference between adjacent tracks. There must be. However, if the structure shown in FIG. 5 is adopted, the recording layer 2 has a hill pattern 5
Since they are separated by and are discontinuous, the track intervals can be reduced. Further, since the recording layer 2 portion and the hill 5 portion can be clearly distinguished by a magnetic method or a method such as laser reflectance, it can be used for discriminating a track.
That is, the disc having the concentric hill pattern 5 shown in FIG. 5 as the sliding portion and the recording portion disposed in the groove between the adjacent hills is nothing but a discrete magnetic disk.
If the pitch between the recording layers adjacent to the hill 5 is set to a high density corresponding to the recording density, information can be recorded / reproduced as one track in each recording layer, and the recording density is extremely high. A magnetic disk can be realized.

FIG. 6 is a fragmentary plan view of a disk 20 showing another configuration example in which the hill pattern 5 used in the present invention has an island-shaped hill. In this case, the effect of improving the track density can be obtained. However, it has the same effect of improving the sliding resistance as in the case of FIG.

In the disk of the present invention, the distribution of the hills 5 should be arranged so that the load is distributed and received by a plurality of hills when the heads come into contact with each other.
In the case of the concentric circle pattern, it is preferable that three or more hills 5 contact each other, and in the case of the island pattern of FIG. 6, several or more hills, preferably 10 or more hills are distributed so as to receive the load. good. If the contact area of the hill 5 is large, the contact resistance between the head and the head is too large. Therefore, the contact area is 10% or less, preferably 3% or less of the contact area when the load of the head is received on a perfect plane. good. Further, it is more preferable to form minute irregularities on the surface portion of the hill 5, which can reduce sliding (contact) resistance. Further, the recessed portion on the surface of the hill 5 plays a role of a lubricating sump (when a lubricating layer is formed), and the lubricating action can be prolonged. The unevenness has, for example, an average roughness Ra of 3 to 10 nm.
Random irregularities or grooves of about 3 to 5 nm are preferable.

(2) Material Constituting Disk First, regarding the non-magnetic substrate 1 used in the present invention, a material that is lightweight, has a certain strength, can be processed flat, and is hard to be cracked. Of course, glass, ceramics, for example, a light alloy such as an aluminum alloy having a hard plating such as NiP, a hard plastic, or the like can be used.

The material forming the hill 5 is made of a non-magnetic material having a high wear resistance different from that of the substrate 1 because it directly contacts the head and forms a sliding portion. A typical example of a material satisfying such characteristics is an amorphous thin film mainly made of carbon, and amorphous hydrogenation formed by plasma-decomposing a hydrocarbon-based gas such as sputtering targeting graphite or methane. There is a carbon film.
Also, cubic BN and the like, which is also obtained by decomposing with plasma, can be used. Of course, for example, B ₄ C, Ti
Among carbides such as C, WC, ZrC, SiC and MoC and metal oxides such as TiO ₂ , TaO ₂ and Y ₂ O ₃ as long as they have high wear resistance, they can be similarly used. Among these, the so-called diamond-like carbon (diamond-like carbon), which is an amorphous hydrocarbon-based thin film and has high hardness, not only has excellent wear resistance, but also has high insulation properties and therefore good corrosion resistance, Since it has a low friction coefficient, it can be preferably used. Further, in the case of a carbon-based thin film, a pattern can be easily formed by etching with oxygen plasma, so that the material of the film forming the island-shaped or concentric (belt-shaped) hill pattern 5 having the structure shown in FIG. Good. In particular, when the layer forming this pattern is made of a material having high wear resistance such as a hard carbon film, the lubricating layer 4 can be formed as it is without forming the protective layer 3 after removing the recording layer 2 thereon. There is an effect of shortening the process.
FIG. 4 shows an example of the magnetic disk thus created. The materials constituting the hill 5 are summarized as follows: amorphous carbon thin film, diamond-like carbon, carbides (these are collectively referred to as carbon-based materials), cubic BN, and metal oxides having high wear resistance. And so on.

The recording layer 2 is, for example, CoCrTa,
CoCrPt, CoCrTi, CoCrW, CoCr
C such as V, CoCrGe, CoNi, CoNiZr, etc.
Fe-based materials such as o-based magnetic alloys, γ-Fe ₂ O ₃ , iron nitride, and Ba ferrite are used, but the present invention is not limited to the material of the recording layer 2 and is not limited to the above materials, and is not limited to thin films. Any known recording layer can be used as long as it is a material having magnetic properties sufficient for recording and reproduction.

The protective layer 3 has at least two roles. One is to protect the recording layer 2 from corrosion, and the other is to prevent abrasion due to sliding with the head. In the present invention, the portion where the recording layer 2 is present has a structure that does not come into contact with the head, but this is not the case when foreign matter is mixed in from the outside or the head has a deposit and forms a convex surface. Sliding can also occur in the recording layer portion. For this reason, the protective layer 3 is provided for the purpose of protecting the surface of the recording layer 2. However, this material must have a sliding durability, and its thickness does not hinder recording and reproduction. It must be thin. For this reason, the material forming the hill 5 described above is used in the present invention, but it is particularly preferable to use a carbon-based material composed of an amorphous carbon thin film, diamond-like carbon, or carbides. An amorphous carbon film is particularly preferable, and it is desirable that the film has a density of 1.7 to 2.1.

With respect to the lubricating layer 4, normally, in a magnetic disk, the coefficient of friction when sliding with the head is lowered,
The lubricating layer 4 is often formed for the purpose of reducing wear and making the surface water-repellent to prevent corrosion. Also in the present invention, it is desirable to form the lubricating layer 4 because the same effect can be obtained. The lubricating layer 4 has, for example, a molecular weight of 10 having a perfluoropolyether main chain.
A fluorine-containing organic polymer material of 0 to 10000, one or both ends of which are modified with an ether, an ester, a hydroxyl group, an amide group, a carboxylic acid metal salt or the like, and an end of an aliphatic polymer is also the same. It is sufficient to apply a lubricant or the like modified to the disk surface. The amount of this lubricant is preferably about 1 to 10 nm in terms of film thickness, and if it is too thick, it adheres to the head and causes dirt and head adhesion. If the protective film 3 has a sufficiently low coefficient of friction and is less likely to wear, the lubricating layer 4
Can be omitted.

(3) Disk Manufacturing Method Next, the disk manufacturing method of the present invention will be described by using the manufacturing process chart shown in FIG. 7 as a representative example of manufacturing the magnetic disk having the structure shown in FIG. To do. As shown in step (a), a non-magnetic material layer 11 forming a hill with a material different from that of the substrate is previously formed on the disk substrate 1 made of, for example, glass which has been processed and polished with good flatness. As described above, this layer is preferably made of a non-magnetic material having high wear resistance such as hard carbon. A resist 8 is applied onto this by a spinner and dried, and then a mask 9 having a desired hill pattern 5 is overlaid and irradiated with ultraviolet light for exposure.

As shown in step (b), the exposed portion is dissolved and removed by immersing it in a developing solution for a certain period of time, followed by development to obtain a resist mask pattern 8. As shown in step (c), the nonmagnetic material layer 11 forming the hill in the portion where the resist 8 is not present is selectively etched by a method suitable for the substrate material. At this time,
In order to facilitate the peeling of the resist in a later step, it is preferable that the remaining wall surface of the resist 8 be side-etched so that the lower part is bitten into a trapezoidal shape with a short base.

As shown in step (d), after cleaning the substrate, the recording layer 2 is formed by a film forming apparatus having a vacuum chamber. In addition, as shown in step (d ′), an extremely thin antioxidant film 10 may be continuously formed for the purpose of preventing the recording layer 2 from being oxidized. As shown in step (e), this substrate is dipped in a resist stripping solution to form the resist 8 and the recording film 2 deposited thereon.
Further, if there is an antioxidant film 10 as shown in the step (e ′), it is peeled off at the same time.

As shown in steps (f) and (f '), this substrate is again placed in a film forming apparatus having a vacuum chamber to form the protective layer 3 on the entire surface. If necessary, this substrate is dipped in a liquid in which a lubricant is dissolved in a certain concentration and lifted up to form a lubricating layer 4. In addition, the inclusion of a step of removing foreign matters and surface protrusions attached during the step is very effective in improving reliability. In this way, the disc having the structure shown in FIG. 1 can be obtained.

Although a positive type resist is used as the resist 8 in the above steps, it is of course possible to use a negative type resist. In this case, the mask pattern 9
Is reversed. As the resist material, those used in the photolithography process of IC or LSI can be used as they are.

As the selective etching method for the nonmagnetic material layer 11 forming the hill 5 in the step (c), oxygen plasma etching can be used when it is amorphous carbon, for example. Further, for materials other than this, for example, ion milling may be used.

Further, it is easy to form the recording layer 2 in the step (d) by magnetron sputtering using a magnetic material having a desired composition as a target, but if the required magnetic characteristics can be achieved, chemical vapor deposition is possible. Other methods such as a method (CVD) or a vapor deposition method may be used. The recording layer 2 may have a single composition, but if the underlayer 6 of, for example, Cr or its alloy is formed as shown in FIGS. 2 to 4, the crystal growth of the magnetic layer 2 thereon can be controlled, Effective in improving magnetic properties. In this case, it is preferable to adopt a method of sequentially forming the underlayer 6 and the magnetic layer 2 while transporting the substrate in a vacuum chamber, or forming a film with a film forming apparatus having a plurality of film forming chambers. .. As described above, the same method can be used for forming the thinner antioxidant layer 10 on the recording layer 2. As the anti-oxidation layer 10, a thin carbon film, a silicon oxide film, a silicon nitride film or the like is used as necessary, but a protective film formed after this can be used instead.

Further, in forming the protective layer 3 in the step (f), magnetron sputtering of graphite or another substance may be carried out, for example, but hydrocarbon gas such as methane is decomposed in plasma to obtain -150V. It is preferable to deposit the hydrogen-containing amorphous carbon film under the above bias voltage condition, and it is possible to form a dense protective layer having high wear resistance. Furthermore, since it serves as a protective film having a high insulating property, even a film as thin as about 10 nm has an effect of preventing corrosion of the recording layer. These materials can also be used as the antioxidant layer 10 which is provided very thinly when the recording layer 2 is formed as described above.

When the selective etching of the material layer 11 forming the hill 5 is stopped halfway, a magnetic disk having a structure in which the roots of the hill 5 are wide and continuous as shown in FIG. 3 is obtained.
Further, in the above step (e), the step of removing the recording layer 2 deposited on the hill 5 may be performed by mechanical processing other than using the resist stripping solution, for example, a polishing tape having abrasive grains fixed thereon is fixed. The hill portion may be scraped off by pressing the substrate with a load and rotating the substrate at a constant speed. In this case, the height of the hill needs to be slightly higher than the finally required height. If the resist 8 is easily mechanically peeled off, an adhesive film or the like is attached and peeled off again to remove the recording layer 2 and the resist 8 on the hill 5.
Can also be removed. If the lubricating layer 4 is formed in a state where the protective layer 2 on the hill 5 is removed, the magnetic disk having the structure shown in FIG. 4 is obtained.

(4) Magnetic Disk Device Next, a magnetic disk device using the magnetic disk 20 of the present invention will be described. FIG. 8 is a partially cutaway perspective view showing an example of the apparatus. At least a plurality of magnetic disks 20 are shown.
A spindle 12 on which the disk is mounted, a drive system 13 for rotating the spindle 12, a magnetic head 14 attached to each surface of the disk, a positioning mechanism 15 for radially aligning the magnetic head 14, a signal to the magnetic head, Alternatively, it comprises a signal processing mechanism 16 for reading out signals from the magnetic head and a housing 17 for accommodating the whole.

As the magnetic disk 20, the hill 5 is used.
If the discrete disk 20 in which the width of the recording layer 2 existing between the concentric hills 5 adjacent to each other is made as narrow as possible corresponding to the track width of the head is used, each recording layer has one Since information can be recorded / reproduced as tracks, a highly reliable recording / reproducing method for a magnetic disk suitable for high-density recording / reproducing can be realized.

[0028]

As described above, according to the present invention, when the magnetic head comes into contact with the magnetic disk and slides, the load is applied to the hill portion having high strength, so that the durability is enhanced. In addition, since there is no principle contact with a portion where the magnetic layer is present, there is an effect of preventing an error due to destruction of the magnetic layer and thermal demagnetization due to heat during sliding, and the reliability of the magnetic disk can be improved.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. <Example 1> A disk 20 having the cross-sectional structure shown in FIG.
An example of manufacturing according to the manufacturing method of steps (a) to (f) shown in FIG. 7 will be described. Hereinafter, the steps will be sequentially described in FIG. Step (a): Ni with a 2.5-inch diameter with a hole in the center
Amorphous carbon 11 was previously formed on the P-plated aluminum alloy substrate 1 by sputtering targeting graphite.
Was formed to a thickness of 150 nm, a positive resist solution was applied on both sides, and the film was rotated to shake off excess resist. As a result, the resist film 8 having a thickness of 1 micron was entirely coated. The substrate was prebaked at about 80 ° C. to evaporate the solvent and dry.

Step (b): Next, using an ultraviolet light exposure device,
Each surface is exposed through a mask 9 having a pattern of concentric circles having a width of 0.5 μm and a spacing of 4.5 μm. Then, the disk is chucked and rotated again, and a developing solution is sprayed and developed at the same time on both surfaces to rinse the solution. I changed to and rinsed. Further, this disc was heated to 110 ° C. and post-baked to form a resist pattern 8.

Step (c): This substrate was etched by oxygen plasma to remove the carbon film 11 in the portion where the resist 8 was not present, and the hill 5 was formed.

Step (d): 50% Cr is used as the underlayer 6 by using an apparatus capable of simultaneously sputtering both surfaces of this substrate.
A film with a thickness of nm (process diagram omitted) and Co
A recording layer 2 was formed by depositing a CrTa alloy to a thickness of 40 nm. Although the process diagram was omitted, carbon was further deposited thereon to a thickness of 10 nm. The substrate temperature during film formation was 150 ° C.

Step (e): This substrate is dipped in a resist stripping solution to form a resist 8 on which the underlying layer 6 and the recording layer 2 are formed.
It peeled off with.

Step (f): After drying this substrate, a carbon protective layer 3 was deposited to a thickness of 30 nm using an apparatus capable of simultaneously sputtering on both sides. Finally, a lubricant with a perfluoropolyether main chain and an average molecular weight of about 4000 was added to an average thickness of 5n.
m was applied to form a lubricating layer 4.

The magnetic disk 20 produced in this way
A sapphire block having one side of which was spherically polished to R30 mm was pressed with a load of 10 gf and rotated at 3000 rpm. 100
After sliding k times, the rotation of the disk was stopped and the damage of the disk was examined. In the disk, the height of the non-sliding hill is about 50 nm, while the height of the sliding hill is about 40 nm.
It was found to be worn out by about 10 nm. Also,
When I continued turning without stopping, it crashed about 1200k times.

Comparative Example 1 For comparison, a tempered glass disk substrate was prepared as the substrate 1, and film formation was sequentially performed according to Example 1 to prepare a magnetic disk having the structure shown in FIG. However, in the case of this comparative sample, the resist 8 was directly formed on the substrate 1 without forming the carbon layer 11 in Example 1, and the glass substrate in the portion without the resist 8 was exposed to light and developed to a depth of 150 nm. A groove for forming a magnetic layer was formed by etching, and the convex portion of the substrate itself left at the time of this etching process was formed as a hill 5. When the same test as in Example 1 was performed on this magnetic disk, it crashed about 500 k times.

Example 2 A magnetic disk having the same structure as in Example 1 and Comparative Example 1 was prepared, in which the thickness of the carbon sputtered film provided as the protective layer 3 was 10 nm and 20 nm, respectively, and the same test was conducted. It was The test results are shown in Table 1 together with the results at 30 nm.

[0038]

[Table 1]

It has been found that when the protective layer 3 is thin, it is more effective to form the hill portion with a carbon film.

Example 3 In Example 1, when forming the constituent material 11 of the hill 5, instead of sputtering carbon, methane was plasma decomposed to form a hydrogenated carbon film having high hardness. The methane gas pressure at this time is 50 mT.
It was orr, and the film was formed so that the substrate had a potential of about -300 to -500 V with respect to the plasma. Hereinafter, the magnetic disk 20 was prepared in the same manner as in Example 1. However, the protective layer 3 provided on the entire surface of the substrate was also formed by plasma decomposition of methane as described above, and the film thickness was set to 10 nm, 20 nm, and 30 nm. The test results at this time are shown in Table 2.

[0041]

[Table 2]

From these results, it was found that a dramatic improvement in durability could be realized as compared with the case of using a carbon sputtered film.

Example 4 A magnetic disk 20 having the structure shown in FIG. 4 was prepared without forming the protective layer 3 in Example 3. In this case, in step (d) of FIG. 7, the underlayer 6, the recording layer 2, and the protective layer 3 are sequentially formed, and then the resist 8 is peeled off to remove these layers formed on the hill 5. Were simultaneously removed, and finally the lubricating layer 4 was formed in step (f). As a result of testing this disk in the same manner as in Example 3, the number of sliding times until crash was about 2000 k times.

<Embodiment 5> The film forming step of the underlayer 6 (Cr is deposited to a thickness of 50 nm) formed in the step (d) of FIG. 7 in the above Embodiment 1 is omitted, and CoCrTa is directly formed on the substrate. The alloy was formed into a film having a thickness of 40 nm to form a recording layer 2. Other steps were performed in the same manner as in Example 1 to prepare the disk 20 having the structure of FIG. As a result of testing this disk in the same manner as in Example 1, the number of times of sliding until the crash is Example 1
It was about 1200k times.

Example 6 The carbon 11 formed in the step (a) of FIG. 7 in the above example 1 was formed into a film having a thickness of 200 nm, and the exposed portion of the exposed portion was masked with the resist 8 in the step (c). The carbon layer 11 is etched to 150 nm and the bottom is
A hill 5 was formed leaving m. Subsequent steps were performed in the same manner as in Example 1 to produce the disk 20 having the structure shown in FIG. As a result of testing this disk in the same manner as in Example 1, the number of times of sliding until crash was about 1200 k times as in Example 1.

<Embodiment 7> In Embodiment 3, the mask 9 used for exposure has a square shape of 1 micron square instead of the concentric circles, and the distance between adjacent squares is 20 micron. As a result, the pattern of the hill 5 formed in the step (c) of FIG. 7 has an island-shaped surface shape as shown in FIG. The thickness of the protective layer 3 was 10 nm. A magnetic disk was prepared and tested in the same manner as in Example 3 except for the above. As a result, the number of sliding times before the crash was 2500k.

Although the substrate 1 is made of an aluminum alloy disc in the above embodiment, the same result can be obtained even if the substrate 1 is made of a light and strong material such as tempered glass, hard plastic or ceramics. be able to.

<Embodiment 8> Using the magnetic disks 20 produced in Embodiments 1 to 7, a magnetic disk device 30 having the structure shown in the partially broken sectional perspective view of FIG. 8 was manufactured. Specifically, the spindle 12 of the rotation drive mechanism 13 having a rotation speed of 5000 rpm
, 4 to 8 magnetic disks 20 are fixed, a thin film head 14 is attached, a gimbal with a load adjusted to 5 gf is attached to the head drive system 15, and one head is placed horizontally on each side of the magnetic disk 20. I was able to press it. The drive power supply circuit and the signal processing circuit 16 were further attached thereto, and the whole was covered with a housing (cover) 17 to assemble the magnetic disk device 30. Power is supplied to this device to rotate the magnetic disk 20,
The device was stopped after being left for 00 hours. When this device was disassembled and the damage of the magnetic disk 20 was examined, no trace of sliding was observed with an optical microscope. No deposit was found on the head.

Comparative Example 2 A magnetic disk device was assembled using the magnetic disk prepared in Comparative Example 1 in the same manner as in Example 8, and power was supplied to rotate the magnetic disk. 250
An abnormal noise was generated after continuous operation for a period of time, and when the device was disassembled after being stopped, damage to the recording layer occurred on the surface of the magnetic disk, and a large amount of deposit was also found on the head.

[0050]

As described above, according to the present invention, the intended purpose can be sufficiently achieved. That is, it is possible to reduce damage to the magnetic disk due to continuous sliding by the magnetic head, and it is possible to greatly extend the life of a magnetic disk of a type that is driven by contact recording or extremely small flying height, and as a result, the recording density of the magnetic disk. Can be dramatically increased compared to the conventional one.
Further, in the example of the discrete disk, the recording tracks can be magnetically separated, which is effective in improving the track density.
Needless to say, the present invention has a great life prolonging effect even with respect to the conventional CSS magnetic disk drive system.

[Brief description of drawings]

FIG. 1 is a sectional view of a magnetic disk according to an embodiment of the present invention.

FIG. 2 is a sectional view of a magnetic disk according to another embodiment.

FIG. 3 is a sectional view of a magnetic disk according to another embodiment of the present invention.

FIG. 4 is a sectional view of a magnetic disk according to another embodiment.

FIG. 5 is a plan view showing an example of a pattern structure of hills on a disk substrate which is another embodiment.

FIG. 6 is a plan view showing a pattern structure example of a different hill.

FIG. 7 is a manufacturing process diagram for manufacturing the same disk.

FIG. 8 is a partially cutaway perspective view of the magnetic disk device.

FIG. 9 is a sectional view of a magnetic disk as a comparative example.

[Explanation of symbols]

1 ... Substrate, 2 ... Recording layer, 3 ... Protective layer, 4 ... Lubrication layer, 5 ... Hill,
6 ... Underlayer, 8 ... Resist,
9 ... Mask, 10 ... Antioxidant film,
11 ... Wear-resistant material layer forming hill, 12 ... Spindle, 13 ... Drive system, 14 ... Magnetic head, 15 ... Head positioning mechanism, 16 ... Signal processing circuit 17 ... Housing, 20 ... Magnetic disk, 30 ... Magnetic disk apparatus.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Matsunuma 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Hitachi, Ltd. Institute of Industrial Science (72) Inventor Naruhiko Fujimaki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa (72) Inventor, Ryo Kito Ryo Kito, Tochika-ku, Yokohama, Kanagawa Prefecture, Ltd. Production Technology Research Laboratory, Hitachi, Ltd. (72) Nobuo Nakagawa, Yoshida, Totsuka-ku, Yokohama, Kanagawa Address 292, Production Engineering Research Laboratory, Hitachi, Ltd. (72) Atsushi Takagaki Yoshida, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address 292 Production Engineering Research Laboratory, Hitachi, Ltd.

Claims (13)

[Claims] 1. A sliding part in which a head contacts a disk,
In a magnetic disk comprising a recording portion adjacent to a recording surface in which the head does not substantially contact and does not slide, the sliding portion has a hill-like structure higher than the recording portion. Is composed of a non-magnetic material having a high wear resistance different from that of the substrate, which allows the head to slide on a hill that serves as a sliding portion and does not substantially contact the head with the recording portion. .. 2. The discrete structure in which the hill-shaped structure forming the sliding portion is a concentric continuous pattern having a predetermined width and pitch, and the recording portion is disposed in the groove between the adjacent hill-shaped structures. 2. The magnetic disk according to claim 1, wherein the magnetic disk comprises a magnetic disk. 3. The magnetic disk according to claim 1, wherein the hill-shaped structure forming the sliding portion is formed as an island-shaped discontinuous pattern. 4. The height of the hill-like structure is formed to be 10 nm to 100 nm higher than that of a recording portion having a recording layer.
4. The magnetic disk according to any one of 1 to 3. 5. A protective layer and a lubricating layer are provided on the recording portion,
4. The magnetic disk according to claim 1, wherein at least a lubricating layer is provided on the hill-shaped structure. 6. The magnetic disk according to claim 5, wherein the protective layer is made of a carbon-based material and the lubricating layer is made of a fluorine-based lubricating layer. 7. The protective layer made of the carbonaceous material has a density of 1.7.
7. The magnetic disk according to claim 6, which is formed of an amorphous carbon film of 2.1. 8. The substrate is made of a non-magnetic disc made of glass, light alloy or ceramics, and the hill-like structure has a carbon-based material layer, a cubic BN layer, a carbide layer,
2. The magnetic disk according to claim 1, which is composed of either a metal oxide layer having high wear resistance. 9. The substrate is made of glass or aluminum alloy, and the hill is made of an amorphous carbon film, diamond-like carbon,
Cubic BN, or B ₄ C magnetic disk according to claim 1, wherein comprising constituted by either. 10. A step of forming, on a non-magnetic substrate, a non-magnetic material layer forming a hill-like structure having high wear resistance unlike the substrate, and a resist film on the non-magnetic material layer forming the hill-like structure. A step of forming a resist pattern having a predetermined width and a predetermined pitch, and a step of selectively forming a nonmagnetic material layer forming the exposed hill-shaped structure by using the resist pattern as a mask A step of etching to a depth such that the height of the hill is substantially higher than the height of the ridge, and forming a hill-like structure which is a concentric or island-shaped concavo-convex pattern on the non-magnetic substrate and becomes the sliding portion of the head. A step of forming a recording layer by forming a recording layer made of a magnetic material in a recess other than the upper part of the hill-like structure and a protective layer at least thereon, and a step of forming a lubricating layer on the entire surface of the substrate. A magnetic device comprising Method of manufacturing a disk. 11. The step of forming a non-magnetic material layer forming a hill-like structure having high wear resistance unlike the substrate is a step of forming a film by applying a plasma to a gas containing at least a hydrocarbon gas. 11. The method of manufacturing a magnetic disk according to claim 10, wherein the step of selectively etching the exposed nonmagnetic material layer using the resist pattern as a mask is a plasma etching step containing oxygen gas. 12. A magnetic disk according to claim 1, a spindle for mounting and fixing the magnetic disk, a power system and a control system for rotating the magnetic disk, a magnetic head for recording and reproducing signals, and a magnetic head for magnetic recording. A magnetic disk device comprising a positioning mechanism for moving to an arbitrary radial position on the disk surface, and a signal processing mechanism. 13. The discrete magnetic disk according to claim 2, wherein the recording layer existing between adjacent concentric hill-shaped structures corresponds to the track width of the magnetic head, and information is recorded and reproduced as one track. Recording / reproducing method for magnetic disk.