JPH0428012A - Magnetic disk, its manufacturing method, and magnetic disk device - Google Patents

Abstract

PURPOSE:To improve the reliability of head sliding by providing plural pieces of specific projections arranged intermittently in a circumferential direction within the slider sliding width of a magnetic head. CONSTITUTION:An Ni-P plating film 2 is formed as an underlying film on a substrate 1 consisting of an aluminum alloy disk. An intermediate film 3 consisting of chromium, a magnetic film 4 of a Co-Ni system and a protective film 5 consisting of carbon are successively formed by sputtering thereon. Finally, a multilayered structure coated with a lubricant 6 is formed. The projections 11 which have 5 to 50nm height and 0.1 to 10mum width and are arranged intermittently in the circumferential direction are provided so as to exist at plural pieces within the slider sliding width of the magnetic head. The head sliding characteristic is improved in this way.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the surface properties of thin film magnetic disks.

In particular, the magnetic head flying characteristics of thin-film magnetic disks and CSS
The present invention relates to a magnetic disk having a surface texture suitable for (contact start/stop) characteristics and anti-sliding characteristics such as magnetic head adhesion, a method for manufacturing the same, and a magnetic disk device.

[Prior Art] Conventionally, as a substrate for a magnetic disk on which a magnetic thin film is formed using a thin film forming technique such as sputtering, plating, or ion blating, there is, for example, a substrate for a magnetic disk formed by using a thin film forming technique such as sputtering, plating, or ion blating.
As described in Japanese Patent No. 626, Ni-
A P-plated film is applied, which is then subjected to grinding, lapping, and polishing using abrasive grains of various particle sizes to achieve a surface roughness in the range of 0.006 to 0.010μ■Ra. It's here. A magnetic film, a protective film, and a lubricating film are formed on this substrate to create a magnetic disk.

The surface roughness of the substrate of this magnetic disk is 0.006 μmR
In the following cases, the lubricant or adsorbed moisture that exists in the minute gap between the head and the magnetic disk (hereinafter simply referred to as disk) during the contact start/stop operation of the magnetic head (hereinafter simply referred to as head) The surface tension of the magnetic head increases the adhesion force and friction coefficient of the head, which may cause damage to the support system of the magnetic head or the surface of the magnetic disk.

Furthermore, when the surface roughness is 0.010 μmRa or more, signal errors in electrical characteristics increase rapidly.

When the flying gap of the magnetic head is 0.15μ, the number of contacts with the head increases. From the above, by setting the surface roughness of the substrate in the range of 0.006 to 0.010 μmRa, it is possible to reduce the coefficient of friction between the magnetic disk and the magnetic head and the adhesive force of the magnetic head. There are fewer defects that can cause signal errors, and it is possible to reduce the number of protrusions on the disk surface that impair the flying stability of the magnetic head.

[Problem to be solved by the invention] However, the above-mentioned conventional technology
It is insufficient to clearly understand the microscopic changes in the surface of the magnetic head and magnetic disk due to the number of 8S cycles, and there is no consideration given to the surface properties of the head and disk that affect CSS characteristics. There was a problem in setting the optimal surface texture.

Therefore, an object of the present invention is to solve such conventional problems, and the first object is to provide a magnetic disk with improved head sliding characteristics such as head flying characteristics, CSS characteristics, and head adhesion characteristics. The second object is to provide a manufacturing method thereof, and the third object is to provide a magnetic disk device incorporating such a magnetic disk.

[Means for Solving the Problems] In order to achieve the above object, the present inventors observed and measured the sliding surfaces of actual heads and disks, and further determined the cross-sectional shape of the sliding surfaces and the sliding surface from the cross-sectional observation. Various dynamic conditions were investigated. From the results, we obtained the knowledge to form an optimal sliding surface.The present invention was made based on the knowledge thus obtained.
The technical background and means of achieving the objective will be explained below.

In order to observe this sliding surface, we repeated the CSS test several thousand times and compared the surface conditions before and after the CSS test.As a surface condition observation and measurement method, we used a surface roughness meter Talystep to measure the head sliding force direction. Measure the cross-sectional shape in the right angle direction.
The measurement point was further moved in the head sliding direction by several microns (μm), and the cross-sectional shape was again measured in the perpendicular direction. The load curve was determined. From this load curve, the load ratio at a cutting depth of 10 nm (this load ratio is
BRIO (hereinafter referred to as O) was determined and compared before and after the C8S test. In addition, in order to observe changes in the surface state, we used a field emission scanning electron microscope, and to examine the surface of the disk, we created a cross-sectional sample of the disk.
A cross-sectional observation of the extreme surface layer was conducted to examine changes due to sliding.

This time, from the above observation and measurement results, the surface quality of a disk with good C8S characteristics is such that the disk surface that is in contact with the head slider surface due to head sliding is several times within the sliding width of the head slider (for example, 400 μm). The range is from 1 to several 10 points, and the contact area, that is, the load ratio BR
IO was found to be between 0.01% and 10%. In addition, from the head flying characteristics, the height of the protrusion in the surface unevenness (Here, the height from the center line to the peak is referred to as RP) R
p was 5 to 50 n@, preferably 20 to 30 n. If the load ratio is lower than 0.01%, the head sliding will cause severe sliding wear on the contact area with the head slider on the disk surface, causing significant damage to the lubricant and protective film on the disk surface layer. This results in damage to the magnetic medium. On the other hand, if the load ratio is higher than 10%, the contact area with the head slider increases, the coefficient of friction increases, and the frictional resistance force during head sliding increases, supporting the head on the head arm. This may result in damage to the gimbal, inability to rotate the disk, or even a head crash.

As mentioned above, the protrusion height is set to 5 to 50 nm, preferably 2 nm.
An example of forming a surface with a uniform thickness of 0 nm to 30 nm and a load ratio BRIO of 0.01 to 10% with good productivity is shown below.

The surface structure of the magnetic disk is AΩ, as shown in Figure 1.
Ni-, P plating 2 is applied as a base film on the alloy substrate 1, and after polishing the plated surface, fine grooves called texturing are formed, and a chromium film 3, for example, is formed as an intermediate layer on the surface. It is formed of a magnetic film 4, a protective film 5, and a lubricating film 6. here,
The thickness of the chromium film 3 is several 10100 nm, for example, 100 nm.
~300nm), and if a minute protrusion exists on the underlying Ni-P plating surface, the protrusion grows in a state of acceleration according to the slope of the protrusion, as shown in Figure 2, and a singularity point is formed. It was found that 11 were formed. For example, Ni-P
It was found that on the surface of the chromium film 3 (deposited by sputtering) on the ugly protrusion where the height Rp of the plating surface 2 is 20n, the protrusion height becomes a singular point 11 of approximately 30rv+~40n■. .

Therefore, it has been found that it is necessary to form a nucleus on the surface of the Ni--P plating 2, which will become the growth point 11 of the chromium film 3 described above. Methods for forming this nucleus include scratching using abrasive grains, cutting using a cutting tool, collision with fine particles, and sputtering (dry etching) using energy beams using ion beams or electron beams.
There is a method of forming it by action, etc.

The means for achieving the object of the present invention based on the above knowledge will be specifically explained below.

The first object of the present invention is as follows.

(1) A magnetic disk with a height of 5 to 50 nu (preferably 10 to 30 n
), width 0.1-10. (2) A magnetic disk having a plurality of protrusions disposed intermittently in the circumferential direction within the sliding width of the slider of the magnetic head; The area of the magnetic disk contact surface in contact with the moving surface is 0.01 to 10% of the slider sliding surface of the magnetic head (
1) Achieved by the magnetic disk described above.

The second object of the present invention is as follows.

(3) a step of forming a non-magnetic underlayer on a non-magnetic disk substrate; and a step of surface-processing the non-magnetic underlayer; Size: 5 to 50 nm (preferably 10 to 30 nm), width: 0
．． A surface processing step of the non-magnetic base film to form nuclei for providing protrusions having a diameter of 1 to 10 μm and arranged intermittently in the circumferential direction, and a step of forming an intermediate layer on the non-magnetic base film. forming a magnetic film on the intermediate layer; and forming a protective film on the magnetic film.
0rv+), a width of 0.1 to 10 μm, and a plurality of protrusions disposed intermittently in the circumferential direction within the sliding width of a slider of a magnetic head. (4) A step of sequentially laminating a nonmagnetic base film, an intermediate layer, a magnetic film, and a protective film on the nonmagnetic disk substrate.

The surface processing step of the protective film has a height of 5 to 50 nm (preferably 10 to 30 nm) and a cap of 0.1 to 10 μm on the protective film; A magnetic disk manufacturing method comprising a surface processing step of forming protrusions arranged intermittently in the local direction,
(5) The surface processing step of the non-magnetic base film is performed by polishing using abrasive grains, cutting using a cutting tool, or dry etching using an energy beam (3).
), and (6), the surface processing step of the protective film is performed by polishing using abrasive grains, cutting using a cutting tool, or dry etching using an energy beam. ) can be achieved by the magnetic disk manufacturing method described in each of the above methods.

The third object of the present invention is as follows: (7) A plurality of magnetic disks are fixed at predetermined intervals on the same axis that can rotate 0 times, and a magnetic head held by a slider is mounted on each of the magnetic disks. The magnetic disk is mounted via a head arm that can reciprocate in the radial direction of the magnetic disk, and the slider slides on the surface of the magnetic disk at a constant rotational speed of the magnetic disk and floats at a predetermined distance to drive the magnetic disk. In the apparatus, the area of the magnetic disk contact surface in contact with the slider sliding surface of the magnetic head is defined as:
With a magnetic disk device consisting of 0.01 to 10%,
In addition, (8) a magnetic disk with a height of 5 to 50 nm (preferably, a thickness of 10 ~30
n) 1 width 0.1~10. The magnetic disk device according to (7) above, wherein a plurality of protrusions arranged intermittently in the circumferential direction are provided within the sliding width of the slider, further comprising (9), The magnetic disk device according to (7) or (8) above, wherein the nonmagnetic disk substrate is an aluminum alloy disk, the nonmagnetic underlayer is a Ni-P plating film, and the intermediate layer is a chromium sputtered film, and also.

(10) The above-mentioned (
This is achieved by the magnetic disk device described in 8) or (9), respectively.

[Function] As shown in FIG. 3, both surfaces of a polished Ni-P plated alloy substrate 9 having a surface roughness of 0.002μ1iRa or less are supported by a pressing jig 8 with a cross tape 7 made of non-woven fabric. Press the contact roller against the board surface,
Between the cross tape 7 and the board surface.

For example, a diamond slurry liquid is supplied to the supply port 10 as the abrasive grains.
The substrate 9 is rotated while being supplied to the substrate surface. Fine irregularities are formed on both sides of the substrate 9, as shown in the surface roughness in FIG. When the chrome ivy film 3 is formed to a thickness of 200 to 300 nm, the height becomes 5 to 50 nm as shown in Figure 2.
A singular point 11 (preferably 20 to 30 nm) is formed.

On this sputtered chromium film 3, a magnetic film 4, a protective film 5,
When the lubricating film 6 is formed one after another, the protrusions at the singular points 11 are reflected and retained on the surface of the subsequent laminated film, thereby creating a magnetic disk with a predetermined surface texture.

As a result, when the magnetic head slides on the surface of this magnetic disk by C8S, the slider surface of the magnetic head moves over the protrusion formed on the disk surface, reflecting the shape of the singular point 11, as shown in 5yA. Since the head mainly slides, there are few contact points between the head and the disk, the head adhesive force is small, and even if the number of C8S is increased, the increase in the head tangential force is only +1. Further, since the height of the protrusion on the disk surface due to the singular point 11 is stable at 5 to 50 nm (preferably 20 to 30 nm), the head flying characteristics are also good.

Note that instead of forming the singular point 11 in the intermediate layer 3 and reflecting this shape on the subsequent laminated film as described above, the protective film 5 which is the outer layer of the laminated film is used as described in (4) of the previous section. A similar surface quality can be achieved by applying the same surface treatment to the surface.

[Example] An embodiment of the present invention will be described below with reference to one drawing.

Example 1 Fig. 1 is a block diagram schematically showing the cross-sectional structure of a magnetic disk, and Fig. 2 shows how the shape of the singular point 11 of the intermediate layer 3 changes as the laminated film is formed on the substrate. FIG. 2 is a cross-sectional structural diagram of a main part of a magnetic disk showing how it is reflected in a laminated film.

The magnetic disk of the present invention includes a substrate 1 made of an aluminum alloy disk, a Ni--P plating film 2 formed as a base film, a chromium intermediate film 3, a Co--Ni magnetic film 4. A carbon protective film 5 is sequentially formed by sputtering, and finally a lubricant 6 is applied to form a multilayer structure.

The surface of the Ni-P plating film 2 was polished to a mirror finish in advance to a surface roughness of 0.002 μmRa or less by double-sided polishing, and the surface processing method shown in FIG. 1 disc 9 while supplying diamond slurry with a uniform abrasive grain size (3μ in this example) from the supply port 10 between the disc 9 and the cross tape 7.
By rotating the cross tape 7 and sliding it back and forth in the radial direction of the disk 9, fine irregularities are formed in the circumferential direction of the disk.

In this example, the surface roughness was 0.009 μmRa. This surface processing causes protrusions (singular point 11) on the intermediate layer 3 after this.
This is a necessary step for forming nuclei to provide a nucleation process, and the fine protrusions on the machined surface serve as the nucleations.

A chromium film 3 with a thickness of 200 to 400 ni+ is formed as an intermediate layer on the Ni-P plating film 2 thus obtained by sputtering, and as shown in FIG. A singular point 11 is formed. These singular points 11 are ridge-shaped with a width of 0.1 to lOμ and a length of 100 to 200μ in the circumferential direction of the disk 9, and a unit length of 100μ in the radial direction of the disk 9. There were several locations.

Also, in the radial direction of the disk 9, the slider I of the magnetic head
II (400 μm in this example), and measure the surface at a distance corresponding to the slider length of the magnetic head about 4 cm in the circumferential direction, that is, 3 mm in the area of 400 μm x 4 layers. In a dimensional load curve,
The load ratio at a depth of 10n+sL from the top to the cut surface was in the range of 0.01 to 10%.

On the surface of this chromium sputtered film 3, a Co-Ni magnetic film with a thickness of about 50 nm is further formed by snobbing, and a carbon film is further formed as a protective film 5 with a thickness of about 50 nm.
Formed. A fluorine-based lubricant film 6 was applied to this surface to form a magnetic disk.

Using this magnetic disk, a CSS test was conducted with a Mn-Zn magnetic head at a flying gap (Hf+y)=0.2μ+w. As a result, as shown in FIG. 6, the head tangential force hardly increased with respect to the number of C8S.

As a result of observing the disk surface after C8S using a field emission scanning electron microscope, it was found that the surface of the slider 12 of the head was affected by the singularity 11 of the chromium sputtered film 3 formed on the Ni-P plated substrate, as shown in FIG. It was found that they were supported by the reflected fine convexities on the surface and were sliding in contact.

Therefore, since the head slider 12 surface and the disk surface are in contact with each other at a minute hill with a height of 10 to 30 nm, the adhesive force due to the surface tension of lubricant and adsorbed moisture is small.
There is almost no damage to the head support gimbal or disk surface during contact start. In addition, since the height of the fine convex portions is uniform at 10 to 30 nm, there is no problem with the head flying gap (HfIy) of 0.2 μm, which causes problems in flying. The head tangential force shown in Figure 6 was measured using a well-known method, that is, by measuring the strain that appears in the head arm that supports the head when the head slider 12 slides on the disk surface in the C8S test. It is. Therefore, an increase in the head tangential force means that the sliding resistance of the head slider 12 is correspondingly large.

<Comparative Example> As Comparative Example 1, after the mirror surface of the Ni-P plated substrate 9 was surface-treated with the same diamond slurry as in Example 1, a diamond slurry with a finer particle size of 1 μm (1/1 of Example 1) was processed. Surface roughness of 0.002 due to particle size of 3)
The surface was processed to μmRa. The above-mentioned example 1 is placed on this disk 9.
A C8S test was conducted on a magnetic disk in which a multilayer film was formed using the same method as described above. The results are shown in FIG. 6 as in Example 1, and the head tangential force in this comparative example is C8
As the number of S cycles increases, the number of errors suddenly increases, resulting in damage to the head support system and a situation in which the disk stops rotating. As a result of observing this disk in the same manner as described above, it was found that the chromium sputtered film 3 had few singular points and was very small.

The three-dimensional load ratio was also high, exceeding 10%.

In addition, as Comparative Example 2, when the abrasive grain size of the diamond slurry was increased to 6μ, which is twice that of Example 1, Ni
- The surface roughness of the P-plated surface is severe, and this shape is reflected on the multilayer coating surface that is subsequently formed, deteriorating the head flying characteristics. Also, many defects that cause signal errors occur due to the effects of scratches, etc. Ta. The three-dimensional load ratio on this magnetic disk surface was low, less than 0.01%.

Note that in this example, the singular point 11 did not appear in the chromium sputtered film 3.

Example 2 This example is a surface processing method for providing a nucleus for forming a singular point 11 on a chromium sputtered film 3 on a Ni-P plated substrate 9 whose both sides are mirror-finished in the same way as in Example 1. Processing was performed using a cutting tool instead of the abrasive grains in Example 1.

As shown in FIG.
was formed. This protrusion 14 is the core.

It has an intermittent length in the circumferential direction of the substrate, and has a height of 5 to 10 nu.
The convex hills were formed at a pitch of 50 to 100 μI in the radial direction of the substrate.

As in Example 1, a sputtered chromium film 3 was formed as an intermediate layer to a thickness of 300 nm on this processed surface, resulting in a height of 10 nm.
A singular point 11 of ~30 nm occurs, and the magnetic film 4, the protective film 5,
A lubricating film 6 was formed, a magnetic disk was prepared, and similar tests were conducted. As a result, similar to Example 1, good results were obtained.

Example 3 In this example, the surface processing dimensions of the Ni-P plating film 2 are as follows:
A processing method using an energy beam instead of processing using a diamond cutting tool as in Example 2 was used to form minute convex portions 14 that serve as nuclei for forming singular points 11 in sputtered chromium film 3.

A focused beam of argon ions was used as the energy beam, and the surface to be processed was irradiated with this to perform etching using a well-known sputtering technique.

Figure 8 shows this situation, and the height is 10n@.

The width of the convex hill is 0.2μ, and the length in the circumferential direction of the substrate 9 is 100μ.
Intermittent core protrusions 14 of ~200 μm were formed at a pitch of 50 to 100 μm in the radial direction.

Thereafter, as a result of sputtering chromium as the intermediate layer 3, a singular point 11 consisting of minute convex portions was formed as in Examples 1 and 2, and this was used to conduct magnetic Manufactured a disc. The thus obtained magnetic disk also had no head adhesion or C8S as in Example 1-2.
We were able to obtain good results regarding the characteristics.

Example 4 This example provides (
This shows an example of the content described in 4).

The Ni--P plated substrate 9 has a mirror surface and is coated with a chromium intermediate layer 3 by a well-known method. Magnetic film 4. A method in which the protective film 5 is sequentially formed by sputtering, and only on the surface of the protective film 5, fine irregularities are formed on the surface of the Ni-P plating film 2 for nucleation in Examples 1 to 3 described above. By applying the same surface processing method as above, a protrusion 1 corresponding to the singular point 11 is formed on the protective film 5.
4 was directly formed.

That is, fine convex portions are formed directly on the surface of the protective film 5 using abrasive grains, a diamond tool, or an energy beam machining method, so that the three-dimensional load ratio to the head slider surface is 0.00 at a cutting depth of 10 nm. 01-10
% was created. When this magnetic disk was examined for head adhesion and C8S characteristics, it showed good results similar to the above-mentioned examples, and the head flying characteristics were also good. Additionally, defects on the board that can cause signal errors in electrical characteristics are significantly reduced.

Electrical characteristics were greatly improved, and a high-performance, highly reliable magnetic disk device was obtained.

Embodiment 5 FIG. 9 is a partially sectional perspective view showing a magnetic disk device 85 constructed using the magnetic disks 80 manufactured according to Examples 1 to 4 described above.

A plurality of magnetic disks 80 are mounted and fixed on the same rotating shaft at predetermined intervals, and magnetic heads 81 for recording and reading information are installed on both sides of each disk.

FIG. 10 is an explanatory diagram schematically showing the relationship between the disk 80 and the head 81 in the disk device shown in FIG. When the disk is at rest or in the initial rotation state, it is pressed onto the disk surface by the gimbal's elastic force and is in contact or sliding state, but when the disk is in a high-speed rotation state The head 81 is in a flying state with a flying height of, for example, a submicron of 0.2 μm due to the effect of the air flow with the disk 80 .

FIG. 11 shows an example of a head slider 12 on which a magnetic head is mounted, and the dimensions of the sliding surface 82 of the slider 12 are a width W of 0.4 m and a length Q of 4 m. The head slider is installed so that the length ρ direction is the same as the circumferential direction of the disk.

The magnetic disk device 85 having the above device configuration has improved sliding characteristics of the head slider 12 on the surface of the magnetic disk 80 and flying characteristics of the magnetic head 81, and can realize highly reliable driving characteristics. Ta.

[Effects of the Invention] According to the present invention, as described above, the surface quality of the magnetic disk is optimized to have uniform and fine convex portions. This optimized fine convex part supports the head slider sliding surface,
As a result, the head adhesion force caused by the surface tension of the lubricant and adsorbed moisture applied to the magnetic disk surface is reduced, and there is almost no increase in the head tangential force due to the number of C8Ss, which has the effect of greatly improving the head sliding reliability. be.

Further, the height of the fine convex portion is 5 to 50, preferably 20 to 50.
Since the thickness is uniform at 30 nm, the head flying property is good, there are few defects such as scratches, signal errors are greatly improved, and an excellent magnetic disk device can be realized.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional structure diagram of a magnetic disk showing one embodiment of the present invention, FIG. 2 is a detailed cross-sectional view of the magnetic disk, and FIG.
The figure is a schematic diagram showing an example of a surface processing apparatus used when surface processing the Ni-P plating film of the base film, which is an embodiment of the present invention. Fig. 5 is a cross-sectional view showing the contact state between the magnetic disk surface and the magnetic head slider surface, and Fig. 6 is a cross-sectional diagram showing the contact state between the magnetic disk surface and the magnetic head slider surface. A characteristic diagram showing changes in the head tangential force, FIG. 7 is a cross-sectional view when surface processing the Ni-P plating film of the base film according to another embodiment of the present invention with a cutting tool, and FIG. 8 is a diagram showing a further embodiment of the present invention. A cross-sectional view of a Ni-P plating film of a base film according to a different embodiment when the surface is processed with an energy beam, FIG. 9 is a partial cross-sectional perspective view of a magnetic disk device of the present invention, and FIG. 10 is a cross-sectional view of a magnetic disk device of the present invention. A schematic diagram showing the relationship between the disk and the head, and FIG. 11 is an external view of the head slider. <Explanation of symbols> 1... Base plate (aluminum alloy disk), 2... Ni
-P plating film, 3... Intermediate layer (chromium film), 4... Magnetic film, 5... Protective film, 6... Lubricating film, 7... Cross tape, 8... Press cure Tool, 9... Disc, 10... Abrasive grain (diamond slurry) supply port, 11
...Singularity, 12...Head slider 13...Bite, 14...Protrusion. 80...Magnetic disk, 81...Head, 82...Slider sliding surface. 84...Head arm, 85...Magnetic disk device.

Claims (1)

[Claims] 1. A magnetic disk with a height of 5 to 50 nm and a width of 0.1 to 50 nm is formed on the surface of a magnetic disk formed by sequentially laminating a nonmagnetic base film, an intermediate layer, a magnetic film, and a protective film on a nonmagnetic disk substrate. A magnetic disk comprising a plurality of protrusions having a diameter of 10 μm and arranged intermittently in the circumferential direction so that a plurality of protrusions exist within the sliding width of a slider of a magnetic head. 2. The magnetic disk according to claim 1, wherein the area of the magnetic disk contact surface in contact with the slider sliding surface of the magnetic head is 0.01 to 10% of the slider sliding surface of the magnetic head. 3. forming a non-magnetic base film on a non-magnetic disk substrate; and surface-processing the non-magnetic base film, comprising:
The intermediate layer to be formed on the non-magnetic base film in the next step has a height of 5 mm.
~50 nm, width 0.1 to 10 μm, and a surface processing step of the non-magnetic base film to form nuclei for providing protrusions arranged intermittently in the circumferential direction, and formation on the non-magnetic base film. forming an intermediate layer on the surface of the magnetic disk, forming a magnetic film on the intermediate layer, and forming a protective film on the magnetic film. . A method for manufacturing a magnetic disk comprising a plurality of protrusions having a diameter of 1 to 10 μm and arranged intermittently in the circumferential direction within the sliding width of a slider of a magnetic head. 4. A step of sequentially laminating a non-magnetic base film, an intermediate layer, a magnetic film, and a protective film on a non-magnetic disk substrate, and a surface processing step of the protective film, wherein the surface processing step of the protective film A method for manufacturing a magnetic disk comprising a surface processing step of forming protrusions having a height of 5 to 50 nm and a width of 0.1 to 10 μm and arranged intermittently in the circumferential direction of the disk. 5. The method of manufacturing a magnetic disk according to claim 3, wherein the surface processing step of the non-magnetic base film is performed by polishing using abrasive grains, cutting using a cutting tool, or dry etching using an energy beam. 6. The method of manufacturing a magnetic disk according to claim 4, wherein the surface processing step of the protective film is performed by polishing using abrasive grains, cutting using a cutting tool, or dry etching using an energy beam. 7. A plurality of magnetic disks are fixed at predetermined intervals on a rotatable coaxial shaft, and a magnetic head held by a slider on each of the magnetic disks is movable back and forth in the radial direction of the magnetic disk. In a magnetic disk drive that is mounted via an arm and in which the slider slides on the magnetic disk surface and floats at a predetermined distance due to a constant rotational speed of the magnetic disk, the slider sliding surface of the magnetic head and The area of the contact surface of the magnetic disk in contact with the sliding surface of the slider of the magnetic head is set to 0.
A magnetic disk device consisting of 01 to 10%. 8. A magnetic disk having a height of 5 to 50 nm, a width of 0.1 to 10 μm, and a circumference of 5 to 50 nm in height and 0.1 to 10 μm in width, 8. The magnetic disk drive according to claim 7, wherein a plurality of protrusions are arranged intermittently in the direction within a sliding width of the slider. 9. The non-magnetic disk substrate is an aluminum alloy disk;
9. The magnetic disk device according to claim 7, wherein the non-magnetic base film is a Ni-P plating film and the intermediate layer is a sputtered chromium film. 10. The magnetic disk device according to claim 8 or 9, further comprising a lubricating film laminated on the protective film.