JPH03252922A - Magnetic disk device, magnetic recording medium and production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To maintain floating stability for a long time by providing lots of specified projections having flat surfaces on the surface of a magnetic disk. CONSTITUTION:The surface of the magnetic disk is divided to concentrically and radially provide recessed parts thereon, leaving projections 7 having flat surfaces with at least an interval of 0.2-50 mum so that the whole surface of a slider mounted on any position on the disk can be brought into contact with the projections while the disk 14 is rotated once. Thereby, frictional force and absorption between a magnetic head and the disk can be reduced, which maintains floating stability of the magnetic head all over the whole surface of the magnetic recording medium and prevents variation in output due to variation in the floating height.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, a magnetic recording medium used therein, and a method for manufacturing the magnetic recording medium.

[Conventional technology]

In recent years, the importance of magnetic disk drives as external storage devices for computer systems has been increasing, and the recording density thereof has been significantly improved year by year.

In order to improve the recording density of magnetic disk devices, it is better to reduce the flying height of the magnetic head during recording and reproduction.
In order to ensure flying stability of the magnetic head at this time, the surface of the magnetic recording medium is required to be as flat as possible.

Incidentally, the frictional force generated between the magnetic head and the magnetic recording medium when starting and stopping a magnetic disk device causes wear of both, causing deterioration of characteristics such as writing characteristics and reading characteristics. Furthermore, if moisture is present between the magnetic head and the magnetic recording medium while the magnetic recording medium is stationary, the two will be strongly attracted to each other. This may cause damage to the magnetic head or magnetic recording medium. Such frictional force and adsorption force tend to increase as the surface of the magnetic recording medium becomes flatter, which conflicts with the above-mentioned requirement for flying stability of the magnetic head as the recording density increases.

In order to reduce such frictional force and adsorption force, it is known to form minute irregularities on the surface of a magnetic recording medium.

As an example, Japanese Patent Laid-Open No. 1-134720 discloses providing island-like protrusions on the surface of a magnetic recording medium.

JP-A-1-122028 discloses that a metal alkoxide solution is applied to the surface of a magnetic layer of a magnetic recording medium and rapidly heated to form a protective layer having irregularities on the surface of the magnetic layer.

JP-A No. 57-20925 discloses that the surface of the magnetic layer or protective layer has a diameter of 0.03 to 0.1 mm and a height of about 0.0 mm.
It is shown that a cylindrical protrusion of 5 μm is provided.

[Problem to be solved by the invention]

All of the above conventional techniques aim to reduce the flying height of the magnetic head with respect to the magnetic recording medium, and in this case, to prevent the magnetic head supporting slider from adhering to the magnetic recording medium.

No consideration is given to maintaining the flying stability of the magnetic head over a long period of time.

An object of the present invention is to provide a magnetic recording medium that can maintain flying stability of a magnetic head.

Another object of the present invention is to provide a magnetic disk device equipped with a magnetic recording medium that achieves the above object.

Still another object of the present invention is to increase the flying height of the magnetic head by 0.2.
It is an object of the present invention to provide a magnetic disk device that can be made to be smaller than .mu.m and maintain flying stability for a long period of time, and a magnetic recording medium therefor.

[Means to solve the problem]

The magnetic disk device of the present invention essentially includes at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate, opposed to the rotating magnetic disk with a small gap, and supported by a slider. In a magnetic disk device comprising a magnetic head, a rotating means for rotating the magnetic disk, and a magnetic head positioning means for moving and positioning the magnetic head to a predetermined position on the magnetic disk, the following is provided on the surface of the magnetic disk. (stomach)
It is characterized by having a large number of convex portions with flat surfaces.

(a) The convex portions are divided on the same circumference and the same radius of the magnetic disk, and there are concave portions between the convex portions, and the distance between the closest convex portions of the magnetic disk is 0. .2-5
(b) The convex portion is arranged so that when the slider is placed at an arbitrary position on the magnetic disk and the magnetic disk is rotated once, the convex portion comes into contact with the entire surface of the slider. There is.

The present invention provides a large number of convex portions with flat surfaces on the surface of a magnetic recording medium, and makes the convex portions meet the requirements (a) and (b) above, thereby reducing the flying height of the magnetic head. It is based on the investigation of the fact that stability can be sustained.

By meeting the requirement (b) above, dust adhering to the magnetic head and slider can be scraped off by the convex portion.

By meeting the requirement (a) above, it becomes possible to discharge dust scraped from the magnetic head and slider to the outside of the slider by utilizing the depressions between the convex portions on the surface of the magnetic recording medium.

Due to the effects based on (a) and (b), it becomes possible to set the flying height of the magnetic head to be extremely small, and moreover, it becomes possible to maintain the flying height of the magnetic head almost constant.

Note that in this specification, a magnetic disk and a magnetic recording medium are the same.

The inventors studied various uneven shapes formed on magnetic recording media, and found that in order to ensure long-term flying stability of the magnetic head, a magnetic layer and a surface protective layer are formed on the substrate. It has been found that when providing the surface of the protective layer with a concavo-convex shape, it is extremely important that the arrangement of the concave-convex shape has the effect of quickly removing fine dust attached to the magnetic head or magnetic recording medium.

Prior art Japanese Patent Application Laid-Open No. 1-134720, Japanese Patent Application Laid-open No. 1-1999-
Neither Japanese Patent Publication No. 122028 nor Japanese Patent Application Laid-Open No. 57-20925 discloses that the unevenness of the surface of a magnetic recording medium has a dust removal effect. In addition, it does not have a concave-convex shape or a concave-convex arrangement that has a dust removal effect.

In the present invention, it is desirable that the convex portions on the surface of the magnetic recording medium have a flat surface, and in particular, it is desirable that all the convex portions be maintained at a substantially constant height.

If the surface of the convex part is sharp or there are sharp protrusions on a flat convex part surface, the flying stability of the magnetic head will deteriorate, and in the worst case, the magnetic head and the magnetic recording medium may come into contact with each other. This may cause damage to the magnetic recording medium or magnetic head.

Furthermore, the non-uniformity of the uneven shape affects the flying stability of the magnetic head, and there is a problem that the flying height tends to change even if the magnetic head and the magnetic recording medium do not come into contact with each other.

Therefore, it is desirable that the convex portions be arranged regularly or almost regularly.

Fluctuations in the flying height of the magnetic head cause output fluctuations during recording and reproduction, contributing to a decrease in the S/N ratio.

Furthermore, depending on the fluctuation of the flying height, the output of the servo signal for positioning the magnetic head will also fluctuate.

Another problem is that the positioning accuracy of the magnetic head is reduced. Such problems due to fluctuations in the flying height of the magnetic head become particularly noticeable as the flying height is reduced to increase the recording density of the magnetic disk device, for example, when the flying height is set to 0.2 μm or less.

As a guideline for the flatness of the convex surface, measure an arbitrary length in the circumferential direction of the magnetic disk surface with a stylus roughness meter, for example 100.
When measuring the height of a protrusion with a length of μm (height from the center line of the top surface of the protrusion to the center line of the adjacent recess), the protrusion with a height exceeding 30% of the maximum height of the protrusion It is desirable not to have it on the surface of the convex portion.

Also, assuming that the height of the convex portion is approximately constant, when measuring the height of the convex portion of an arbitrary length, for example, 100 μm, using a stylus type roughness meter, the height of the convex portion is 50% or more of the maximum height of the convex portion. Regarding the height of the convex portions, it is desirable that there be no convex portions with a height exceeding 30% or less than 30% of the average height.

It is desirable that the distance between the closest convex portions of the magnetic disk, that is, the magnetic recording medium, be 0.2 to 50 μm.

The number of convex parts is 400 pieces/mm2 or more, and 250,000 pieces/mm2 or more.
It is desirable that the number of particles does not exceed 0 pieces/mm2.

If the convex portions are sparsely present, air flow is likely to be disturbed, and the flying height of the magnetic head is likely to fluctuate. On the other hand, if the convex portions are present too densely, dust will be difficult to discharge.

The size of each convex portion is preferably 0.1 μm or more and 10 Pm or less in the radial width of the magnetic disk, and 0.5 μm or more and lnwn or less in the circumferential width of the magnetic disk.

If the width in the radial direction is smaller than 0.1 μm, when dust collides with the convex portion, the convex portion may not have sufficient strength and may be damaged. If the width of the convex portion in the radial direction is larger than 10 μm, it will be difficult for dust to move to both the left and right sides of the convex portion, and there is a risk that the dust will be trapped.

If the width of the convex portion in the circumferential direction is smaller than 0.5 μm, the strength will be weak when dust collides with it, and if it is larger than 1 m+, it may be difficult for dust to be discharged in the radial direction of the magnetic disk.

The height of the convex portion is higher than 5 nm and lower than 40 nm,
It is desirable to have a substantially constant height within that range.

Further, it is desirable that the convex portions be provided such that the area ratio of the total area of the convex portions per square millimeter is 0.1% or more and 80% or less within the convex formation region on the surface of the magnetic disk.

It is desirable that the convex portions be arranged regularly or almost regularly on the surface of the magnetic disk so that the deviation in the area ratio of the convex portions on the same circumference is within 20% per square millimeter.

If the distribution of the convex portions varies significantly, there is a risk that the flying height of the magnetic head will fluctuate.

In order to facilitate the discharge of dust to the outside of the magnetic disk using the recesses between the convex portions on the surface of the magnetic disk, it is desirable that the bottom surfaces of the recesses be as flat as possible.

As a guideline to ensure that the bottom surface of the recess is a flat surface, a convex portion with a height exceeding 30% of the maximum convex height at an arbitrary length measured with a stylus roughness meter, for example, 100 μm, is placed in the recess. It is desirable not to have one.

Furthermore, in order to facilitate the discharge of dust toward the outer periphery of the magnetic disk, it is desirable to arrange the protrusions so that they are sequentially shifted toward the outer periphery with respect to the magnetic head when the magnetic disk is rotated.

According to the present invention, the gap between the magnetic disk and the magnetic head can be set to an unprecedentedly small gap of 0.02 to 0.2 μm, and the flying height can be stably maintained.

The convex portions on the surface of the magnetic disk can be formed, for example, by the following methods (1) and (2).

■Protrusions are formed directly on the surface of the substrate or on the surface of a substrate that has an underlayer. ■Protrusions are formed on the surface of the magnetic layer. ■Protrusions are formed on the surface of the protective layer.

When the flying height of the magnetic head is significantly reduced to 0.02 to 0.2 μm, unevenness on the surface of the magnetic layer tends to affect the reduction in the S/N ratio. Therefore, in order to significantly reduce the flying height of the magnetic head, it is desirable to form the magnetic layer with a flat surface and form a convex portion on the surface protective layer thereon.

However, even if a convex part is formed on the substrate surface or the magnetic layer surface as in (2) above, if the shape of the formed convex part is substantially maintained up to the magnetic disk surface, the flying height will be stable. It is effective enough for maintenance.

The substrate of a general magnetic recording medium is an aluminum alloy disk,
It consists of a hard base layer formed on top of it. If a hard disk material such as glass or ceramics is used instead of aluminum alloy, the base layer may be omitted6.
In the present invention, these materials are collectively referred to as a substrate. A magnetic layer is formed on the substrate, and an intermediate layer may be formed between the two for the purpose of improving adhesion and improving the characteristics of the magnetic layer. A protective layer and, if necessary, a lubricating layer are formed on the magnetic layer to constitute a magnetic recording medium.

In the present invention, the protective layer and the lubricating layer are collectively referred to as a surface protective layer.

The protective layer is not limited to just one layer, but may be formed in multiple layers.

The following (a) to (d) are methods for manufacturing magnetic recording media.
The method is preferred.

(a) A method for manufacturing a magnetic recording medium comprising a lubricating layer and a protective layer below the lubricating layer as a surface protective layer, in which a mask pattern is formed on the surface of the protective layer, and the protective layer is coated within the thickness of the mask. After etching according to the pattern, the mask pattern is removed to form a convex portion with a desired shape and two dimensions, and then the lubricant layer is formed thereon.

(b) In a method for manufacturing a magnetic recording medium comprising a lubricating layer and a protective layer below the lubricating layer as a surface protective layer, a mask pattern is formed on the surface of the protective layer by lithography technology, and the protective layer is formed within a range of its film thickness. After etching according to the mask pattern, the mask pattern is removed to form a convex portion of desired size and shape, and then the lubricant layer is formed thereon.

(c) A method for manufacturing a magnetic recording medium comprising a lubricating layer and a protective layer below the lubricating layer as a surface protective layer, in which a film of a substance that can be hardened by light, laser, or charged particle beam irradiation is applied to the surface of the protective layer. desired dimensions by selectively irradiating the film surface with light, laser, or a beam of charged particles to partially cure it, and then removing the uncured portion.

A shaped convex portion is formed, and then the lubricant layer is formed thereon.

(d) In a method of manufacturing a magnetic recording medium by forming a lubricating layer and a two-layer protective layer as a surface protective layer, after forming the two protective layers, a mask pattern is formed on the surface, and the second layer, which is the upper layer, is formed. After etching the protective layer of the eye according to the mask pattern, the mask pattern is removed to form convex portions with desired dimensions and shapes on the surface of the first protective layer, and then a first lubricant layer is formed. Form.

In addition to the above-mentioned three patent publications, the following are conventional techniques for forming unevenness on the surface of a magnetic recording medium.

JP-A-55-84045: A protective layer with a surface roughness of 20 to 50 nm is formed on a mirror substrate.

JP-A-58-53026: The surface of the protective layer is irradiated with gas ions to be etched to a surface roughness of 50 to 1100 nm.

JP-A-62-22241: Forming irregularities on a protective layer within a range not exceeding the thickness of the protective layer.

JP-A-62-231427: Concentric grooves are formed on the surface of the protective layer.

JP-A-62-222435: A cured film protective layer of metal alkoxide is partially irradiated with a laser to form irregularities.

JP-A-63-188821: A silicone oil film is formed as a protective layer and partially cured with an excimer laser to form spiral, concentric or spot-like irregularities.

JP-A-1-13227: A concentric protective layer is formed which is larger in thickness than the lubricating layer and smaller than the protective layer.

JP-A-62-107427: A lubricating film (protective layer) mainly made of carbon is roughened by polishing.

JP-A-63-191312: The surface of the protective layer is polished in the circumferential direction to form irregularities.

JP-A-61-120344: After forming a protective layer containing a material harder than the magnetic head, a portion is sputter-etched to form minute protrusions.

JP-A-63-29320: A hard substance is fixed in the form of islands on a magnetic layer.

JP-A-61-216114: Forming irregularities on a plasma polymerized protective layer of an organic compound.

Japanese Unexamined Patent Publication No. 62-24423: An unevenness is formed on the protective layer within a range not exceeding the thickness of the protective layer.

JP-A-63-168830: The surface of a protective layer having a two-layer structure is plasma etched to form irregularities.

JP-A-1-109527: unevenness is formed on a low hardness protective layer on the surface of a magnetic recording medium using a stamp.

None of these techniques discloses forming unevenness to discharge dust attached to the magnetic head supporting slider to the outside of the magnetic disk, nor does it have such a function.

[Effect]

According to the present invention, firstly, by providing the surface of the surface protective layer with the convex portion, only the curved portion directly faces the magnetic head, reducing the area ratio of the magnetic recording medium in contact with the magnetic head. , it is possible to reduce the frictional force and attraction force with the magnetic head. Second, by arranging the convex portions formed on the surface protective layer regularly or almost regularly, fluctuations in the flying height of the magnetic head are reduced, and the flying stability of the magnetic head is improved by disposing them over the entire surface of the magnetic recording medium. can be ensured, and output fluctuations due to fluctuations in flying height can be prevented. Thirdly, when the magnetic layer is formed on a substrate processed to be flat, the magnetic layer also becomes substantially flat, and output fluctuations during recording and reproduction due to unevenness of the magnetic layer can be reduced.

As described above, according to the present invention, it is possible to reduce the frictional force and adsorption force with the magnetic head, prevent output fluctuations, and ensure the stability of the magnetic head. It is possible to obtain a magnetic recording medium that can cope with the reduction in flying height of a magnetic head that accompanies an increase in recording density, and a magnetic disk device using the same.

Furthermore, fourthly, by arranging the convex portions provided on the first surface protective layer in such a manner that fine dust attached to the magnetic head or magnetic recording medium can be quickly removed.

The flying stability of the magnetic head can be ensured over a long period of time without causing the magnetic head to crash due to minute dust particles.

As described above, according to the present invention, it is possible to ensure stable flying of the magnetic head over a long period of time, so it has high recording and reproducing accuracy, can cope with the reduction in the flying height of the magnetic head accompanying the increase in recording density, and can maintain stable flying over a long period of time. A durable magnetic recording medium and a magnetic disk device using the same can be obtained.

〔Example〕

The present invention will be specifically explained below.

It is desirable that the convex portions provided on the surface of the surface protective layer satisfy the requirements (a) and (b) described in the claims and are regularly arranged. Thereby, the flying height of the magnetic head can be stably controlled over the entire surface of the magnetic recording medium, and output fluctuations due to fluctuations in the flying height can be suppressed. In particular, at least at any point on the same circumference with respect to the rotation center of the magnetic recording medium, if the area ratio of the convex parts per unit area, for example, per square millimeter, is approximately constant, the magnetic head can be moved to a certain track. When the magnetic recording medium is rotated while remaining stationary, the magnetic head always approaches the convex portion at approximately the same area ratio within the size range of the slider, and fluctuations in flying height can be suppressed to a low level. Furthermore, if the area ratio of the convex portion per unit area, for example, per square millimeter, is made to be approximately constant over the entire surface of the convex forming portion, even when the magnetic recording medium is rotated and the magnetic head is moved, The magnetic head always faces the convex portion at approximately the same area ratio within the size range of the slider, so that fluctuations in the amount of Il can be suppressed to a low level over the entire surface. However, depending on the rotation of the magnetic recording medium, the linear velocity differs between the inner and outer peripheries, so if necessary, the area ratio of the convex portions may be continuously changed little by little from the inner periphery to the outer periphery. good.

The convex portions provided on the surface of the surface protective layer are discontinuous at least on the same circumference of the magnetic recording medium. This is because when the magnetic head is stationary and the magnetic recording medium is rotated, the magnetic head will intermittently touch the protrusion when viewed from a certain point, and this makes it easy to prevent even if minute dust adheres to the magnetic head. This is because it will be removed.

Furthermore, the protrusions provided on the surface of the surface protective layer are in the form of discontinuous lines or pits, and at least a portion of the non-protrusions extends from the inner circumference to the outer circumference of the magnetic recording medium within the movement area of the magnetic head. It is desirable that it be smoothly continuous. This is because even if minute dust enters between the magnetic head and the magnetic recording medium, the minute dust is likely to be removed toward the outer circumferential side by centrifugal force along the non-convex portion.

The most suitable arrangement of the convex portions that satisfies all of the above conditions is as follows. For example, linear or pit-shaped protrusions made of a part of a concentric circle or a spiral arc are regularly arranged over the entire surface of the rotation center of the magnetic recording medium or the center of a pattern intentionally arranged from the rotation center. The protrusions are arranged so that at least part of the portion without protrusions continues smoothly from the inner circumference to the outer circumference of the magnetic recording medium within the movement area of the magnetic head. To give a more specific example, for example, the width is 2 μm.
, on an arc concentric with the rotation center of the magnetic recording medium with a pitch of 6 μm, arc-shaped convex portions corresponding to, for example, 0.02 degrees in the center angle are arranged at intervals of 0.03 degrees in the rotation direction of the magnetic disk. They are formed over the entire surface, sequentially shifted toward the inner circumferential side by 2 μm. An example of the arrangement pattern of the convex portions shown here is schematically shown in FIG. In this specific example, when a slider is placed on a magnetic disk and the magnetic disk is rotated, the convex portions are sequentially shifted toward the outer circumferential side and touch the entire surface of the slider, which is highly effective in removing dust attached to the slider. In addition, the cut portion of the convex portion 7 is a magnetic recording medium (
Since the magnetic disk (magnetic disk) 14 continues linearly from the inner circumference to the outer circumference, even if minute dust enters between the magnetic head and the magnetic recording medium, the minute dust is easily removed toward the outer circumference by centrifugal force. In reality, the shape is such that a large number of arcuate convex portions are arranged over the entire surface as shown in FIG.

FIG. 9 shows the arrangement of the convex portions of this specific example on an actual scale at a position of radius 50III11 of the magnetic disk for an area of 200 μm square.

In this example, - the area ratio of convex parts per square millimeter is approximately 22% over the entire surface of the magnetic disk, and - the number of convex parts per square millimeter is approximately 6,500 at a position with a radius of 501 m. .

Variations of this specific example include the arrangement shown in Fig. 5 in which the size and pitch of the protrusions are changed, and the arrangement shown in Fig. 5 in which the arrangement of the protrusions is shifted diagonally.
There is an example as shown in Figure 0.

As another example, it is preferable that pit-like convex portions are regularly arranged over the entire surface at portions corresponding to the vertices of a regular lattice pattern. To give a more specific example, pit-shaped protrusions with a diameter of 2 μm, for example, are arranged over the entire surface at portions corresponding to the intersections of a square lattice with a pitch of 4 μm, for example. An example of the arrangement pattern of the convex portions shown here is schematically shown in FIG. In reality, the shape is such that a large number of pit-like convex portions 7 are arranged over the entire surface as shown in FIG.

The lattice pattern used here may be any pattern regularly drawn, such as a triangular lattice or a hexagonal lattice, in addition to the above-mentioned square lattice. When the convex parts are arranged in this way,
When the slider is stationary and the magnetic recording medium is rotated,
Since the convex portions intermittently touch the entire surface of the slider, it is highly effective in removing minute dust adhering to the slider. In addition, in this example, the gaps between the convex parts are linearly continuous from the inner circumference to the outer circumference of the magnetic recording medium, so even if minute dust enters between the magnetic head and the magnetic recording medium, the centrifugal force As a result, fine dust is easily removed to the outer circumferential side. In this example, the area ratio of protrusions per square millimeter is approximately 20% over the entire surface of the magnetic disk, and the number of protrusions per square millimeter is approximately 6 over the entire surface of the magnetic disk.
There are 2,500 pieces.

In addition to the above, there are also protrusions arranged so as to have the function of removing minute dust attached to the magnetic head and the function of removing minute dust interposed between the magnetic recording medium and the magnetic head in the direction of the outer circumference of the magnetic recording medium. Any other arrangement may be used as long as it is a section.

It is desirable that the height of the convex portions provided on the surface of the surface protective layer be substantially constant in the range of 5 nm or more and 40 nm or less. When the height of the convex portion is lower than 5 nm, the effect of reducing the frictional force and attraction force between the magnetic head and the magnetic recording medium becomes small. If the height of the convex portion is higher than 40 nm, the distance between the magnetic head and the magnetic layer of the concave portion between the convex portions increases during recording and reproduction, resulting in a decrease in output and a loss of flying stability of the magnetic head. Furthermore, if the heights of the convex portions are uneven, the high portions become protrusions, which is unfavorable for flying stability.

The width in the radial direction of the convex portion provided on the surface of the surface protective layer is 0.
．． The thickness is desirably 1 μm or more and 10 μm or less, preferably 0.3 μm or more and 3 μm or less. If the width of the convex portion is smaller than 0.3 μm, it may be difficult to obtain accuracy when forming the convex portion. When the width of the convex portion is larger than 3 μm,
There is a possibility that the effect of reducing the frictional force and attraction force between the magnetic head and the magnetic recording medium will be reduced.

The area ratio of the convex portions provided on the surface of the surface protective layer is 0.1
% or more and 80% or less, preferably 0.5% or more and 70%
The following are desirable. If the area ratio of the convex portion is less than 0.5%, the magnetic head is supported by a small area, so that the convex portion is likely to wear out and the long-term sliding durability is reduced. Further, if the area ratio of the convex portion becomes small, there is a possibility that the floating-E stability of the head will be impaired. When the area ratio of the convex portions exceeds 70%, the effect of reducing the frictional force and attraction force between the magnetic head and the magnetic recording medium becomes small.

The range in which the convex portions of the surface protective layer are formed may be the entire surface of the magnetic recording medium, but depending on the specifications of the magnetic disk device in which the magnetic recording medium is installed, a contact start/stop (CSS) zone is provided exclusively. in case of,
It may be formed only in that part. The reason for this is that, as mentioned above, the frictional force and adsorption force with the magnetic head, the influence of fine dust, etc. are problems that occur mainly when starting and stopping the magnetic disk drive, and the magnetic head does not float stably. This is because the effect of forming the convex portion is relatively small in this state.

The material for the protective layer is preferably one with high hardness from the viewpoint of wear resistance. Examples of such materials include AQ, S
i, Ti, V, Cr, Zr, Nb.

It is desirable to use metal oxides such as Mo, Hf, Ta, and W, nitride dicarbide, and C, BN, etc. alone or in combination of two or more thereof. When viewed as a magnetic disk device, it is desirable that the hardness of the protective layer material of the magnetic recording medium is equal to or higher than the hardness of the slider material of the magnetic head to be combined. This is because when abrasion occurs due to sliding, abrasion of the protective layer tends to cause deterioration of the characteristics of the magnetic recording medium, but minute abrasion on the slider side has relatively little effect on the characteristics of the magnetic head.

A specific example of such a combination is, for example, a combination of the above-mentioned protective layer material and an Mn-Zn ferrite slider.

A specific method for forming the magnetic recording medium according to the present invention is as follows. A magnetic layer and a protective layer are formed on a mirror-finished nonmagnetic disk-shaped substrate. An intermediate layer may be formed between the substrate and the magnetic layer. A method for forming convex portions on the surface of the protective layer is to form a desired mask pattern on the surface of the protective layer using, for example, lithography technology, and then perform etching, selectively and uniformly etching only the portions not covered by the mask pattern. It is preferable to remove the mask pattern after removing the mask pattern to a certain depth with a thickness equal to or less than that of the protective layer. The etching method used here is selected from tri-etching such as ion milling, reactive plasma treatment, wet etching, etc. depending on the material of the protective layer. In addition, the protective layer used here can be formed by forming an upper protective layer material of a certain height on a lower protective layer of a constant thickness by forming the above pattern under the condition that only the upper layer is etched as a uniform single layer structure. A convex portion can be formed.

Another method for forming convex portions is to apply light or light to the surface of the protective layer.
A material that can be hardened by laser or charged particle beam irradiation is formed into a film, and light is applied to the surface of this film.

It can also be formed in the same way by regularly irradiating a desired position with an L-nose or a beam of charged particles to partially cure it, and then removing the uncured portion.

In addition to the above methods, other methods may be used as long as the shape of the convex portions finally obtained is the desired shape6.
For example, a photodegradable organometallic gas is introduced onto a mirror-finished nonmagnetic disk with a magnetic layer and a protective layer formed thereon, and a laser beam is periodically and regularly directed onto the disk. A convex portion having a similar shape can also be formed by a method of selectively depositing metal by irradiation (laser CVD method).

If necessary, a lubricating layer is formed on the protective layer having the convex portions formed on the surface as described above to form a magnetic recording medium.

Note that in the above manufacturing method, a method is shown in which a convex portion is formed on the surface of a protective layer, but after forming a convex portion on a mirror-finished substrate by a similar method, the intermediate layer, magnetic layer, and protective layer are formed. If the lubricant layer and the lubricant layer are each formed to have a constant thickness, the shape of the convex portion formed on the substrate is substantially maintained up to the surface of the magnetic disk, so it is possible to obtain a magnetic recording medium having a similar surface shape.

FIG. 8 is a schematic diagram showing the configuration of a magnetic disk device according to an embodiment of the present invention.

The magnetic disk device includes components 11 to 18 shown in FIG. 8 and a voice coil motor control circuit.

Reference numeral 11 is a base, and reference numeral 12 is a spindle.

A plurality of disc-shaped magnetic disks 14 are attached to one spindle as shown in the figure.

In Figure 8, five magnetic disks 1 are mounted on one spindle.
Although an example in which four sheets are provided is shown, the number is not limited to five.

Further, a plurality of magnetic disks 14 may be installed on one spindle 12 in this way.

Reference numeral 13 denotes a motor for driving the spindle 12 and rotating the magnetic disk, that is, a magnetic disk rotation control means.

Reference numeral 15 indicates a data magnetic head, and reference numeral 15a indicates a positioning magnetic head.

Reference numeral 16 is a carriage, reference numeral 17 is a voice coil, and reference numeral 18 is a magnet.

The voice coil 17 and magnet 18 constitute a voice coil motor.

And code 16. Code 17. The element 18 positions the head. Therefore the code 16.17.18
collectively referred to as the magnetic head positioning mechanism.

The voice coil 17 and the magnetic heads 15 and 15a are connected via a voice coil motor control circuit.

In FIG. 8, the host device is, for example, a computer system, which has a function of processing information recorded on a magnetic disk device. In this recording and reproducing method, the magnetic head and the magnetic recording medium are in contact before the start of operation, but a space is created between the magnetic head and the magnetic recording medium by rotating the magnetic recording medium, and recording and reproducing is performed in this state. Do this. At the end of the operation, the rotation of the magnetic recording medium stops, and the magnetic head and the magnetic recording medium are brought into contact again.

This is the contact start/stop method, hereinafter referred to as CS.
This is called the S method.

FIGS. 9, 10, and 1 are plan views of the surface of a magnetic recording medium, showing examples of the arrangement of convex portions. 9 and 10 show the present invention, and FIG. 11 shows a comparative example.

The square frame indicates a 200 μm square area on the surface of the magnetic recording medium.

The comparative example in FIG. 11 shows an example in which convex portions are formed continuously in the circumferential direction.

The present invention will be explained in more detail with reference to more specific examples below.

<Example 1> An N1-P base film was formed to a thickness of 15 μm on the surface of an aluminum alloy disk with an outer diameter of 5.25 inches by electroless plating, and the base film was polished to 1-0 μm. Mirror finishing was performed so that the average roughness (Ra) was 3 nm or less and the maximum roughness (Pmax) was 7 nm or less as measured using a surface roughness meter.

On the substrate thus obtained, a Cr intermediate layer was formed to a thickness of 0.2 μm, a Co--Ni magnetic layer was formed to a thickness of 40 nm, and a C protective layer was formed to a thickness of 20 nm by sputtering. A positive resist (Tokyo Ohka, 0FPR800) is applied to the surface of the C protective layer.
．． It was coated to a thickness of 5 μm, exposed with a photomask formed in the shape shown in Figure 4 so that only the convex portions do not transmit light, and then developed. A mask pattern was formed in which the resist remained only on the convex portions.

The entire surface of this disk is irradiated with an argon ion beam for 30 seconds using an ion milling device to uniformly etch the areas where no mask pattern is formed, and then the mask pattern is removed using a resist removal solution to protect the disk. Regularly arranged protrusions were formed on the surface of the layer.

A perfluoropolyether lubricant was applied as an IA lubricant layer to a thickness of about 5 nm on the surface of the disk thus obtained to produce a magnetic recording medium. The height of the formed convex portions was determined using a scanning tunneling microscope (Scanning Tunneling Microscope) at arbitrary 10 points on the surface of the magnetic recording medium.
As a result of measurement using a stylus type surface roughness meter (STM) and a stylus type surface roughness meter, the height of the convex portion was 10 at all measurement points.
It was nm. When the surface of the magnetic recording medium obtained by Auger electron spectroscopy was measured, CO and Ni were not detected, confirming that there was no exposed portion of the magnetic layer. The size of the protrusions and the spacing between the protrusions are as shown in FIG.

A schematic diagram of the cross-sectional structure in the radial direction of the magnetic recording medium of this example is shown in FIG. 1E. In FIG.

Reference numeral 1 indicates an aluminum alloy disk, 2 indicates a base layer, 3 indicates an intermediate layer, 4 indicates a magnetic layer, 5 indicates a protective layer, and 6 indicates a lubricating layer. The disk 1 and the base layer 2 constitute a substrate. In this example, the area ratio of the convex portions is approximately 22% over the entire surface.

<Example 2> Using a photomask having the shape shown in Figure 5 so that only the convex portions do not allow light to pass through, the thickness of the C protective layer was set to 30 nm, and ion milling was performed to form the convex portions. A magnetic recording medium was produced in the same manner as in Example 1, except that the etching time was changed to 1 minute. The height of the convex portion was measured at ten arbitrary points on the surface of the magnetic recording medium using a scanning tunneling microscope and a stylus surface roughness meter. As a result, the height of the convex portion was 20 nm at all measurement points. The size of the protrusions and the spacing between the protrusions are as shown in FIG. FIG. 7 shows an example of the results of measuring the convex portions on the surface of the magnetic recording medium according to this example in the radial direction using a stylus type surface roughness meter. In this example, the area ratio of the convex portions is approximately 19% over the entire surface.

<Example 3> Example 1 except that a photomask having the shape shown in FIG. 6 and formed so that only the curved portions do not transmit light was used.
A magnetic recording medium was fabricated in the same manner as described above. The height of the hill was measured at ten arbitrary points on the surface of the magnetic recording medium using an STM and a stylus surface roughness meter. As a result, the height of the convex portion was 10 nm at all measurement points. The size of the protrusions and the spacing between the protrusions are as shown in FIG.

FIG. 2 shows a schematic diagram of the cross-sectional structure in the radial direction of the magnetic recording medium of this example. In this example, the area ratio of the convex portions is approximately 20% over the entire surface.

<Example 4> Magnetic recording was performed in the same manner as in Example 1, except that SiC was formed as a protective layer to a thickness of 20 nm by sputtering, and the etching time by ion milling to form convex portions was changed to 20 seconds. A medium was prepared.

A stylus type surface roughness meter measures any 10 points on the surface of a magnetic recording medium.
As a result of measuring the height of the convex portion at each point, the height of the convex portion was 10 nm at all measurement points.

<Example 5> As a protective layer, a C film (so-called 1-C) formed to a thickness of 20 nm by plasma CVD using a methane-hydrogen mixed gas as a raw material was used, and etching was performed by ion milling to form convex portions. A magnetic medium was produced in the same manner as in Example 1, except that the time was changed to ↓ minutes. As a result of measuring the height of the convex portion at 10 arbitrary points on the surface of the magnetic recording medium using a stylus type surface roughness meter, the height of the convex portion at any measurement point was 10.
It was nm.

<Example 6> On the same substrate as in Example 1, a 0.2 μm thick Cr intermediate layer, a 40 nm thick Co-Ni magnetic layer, a 10 nm thick SiC first protective layer, and a 10 nm thick SiC layer were formed by sputtering. C was formed as a second protective layer to a thickness of lonm. A mask pattern was formed on the surface of the second protective layer C in the same manner as in Example 1, and after exposure to oxygen plasma for 1 minute using an oxygen asher device, the mask pattern was removed using a resist removal solution.

Analysis of the obtained disk surface revealed that in areas where there was no mask pattern, C disappeared due to oxygen plasma etching and SiC was exposed, and C remained in a convex shape only in areas where the mask pattern was present. I understand. As a result of measuring the height of the convex portion at 10 arbitrary points on the disk surface using a stylus type surface roughness meter, the height of the convex portion at any measurement point was 10 nm.
This shows that 83C was hardly etched by the oxygen plasma.

A perfluoropolyether lubricant was applied as a lubricant layer to a thickness of about 5 nm on the surface of the disk thus obtained to produce a magnetic recording medium.

<Example 7> On the same substrate as in Example 1, a Cr intermediate layer was formed to a thickness of 0.2 μm, a Co-Nj magnetic layer was formed to a thickness of 40 nm, and a SiC layer was formed as a protective layer to a thickness of 10 nm by sputtering. Si
After spin-coating a tetrahydroxysilane solution to a thickness of approximately 15 nm on the surface of the C protective layer, an Ar laser focused to a spot diameter of 2 μm was selectively irradiated only to the curved portion in the pattern shown in Figure 4. After the tetrahydroxysilane in the irradiated area is changed to SiO2 and cured, the tetrahydroxysilane in the uncured area is washed and removed to form convexes regularly arranged on the surface of the protective layer as shown in Figure 4. The division was formed.

A magnetic recording medium was prepared by applying a perfluoropolyether lubricant to a thickness of about 5 nm as a lubricant layer on the surface of the disk thus obtained. The height of the formed convex portions was measured at ten arbitrary points on the surface of the magnetic recording medium using a stylus type surface roughness meter. As a result, the height of the convex portions at all measurement points was 10 nm.

In this example, the area ratio of the convex portions is approximately 2 over the entire surface.
It is 2%.

<Example 8> As a substrate, the average roughness (R
a) A magnetic recording medium was prepared in the same manner as in Example 1, except that a tempered glass disk with an outer diameter of 5.25 inches that was mirror-finished to have a roughness of 2 nm or less and a maximum roughness (R-ax) of 5 nm or less was used. was created. As a result of measuring the height of the convex portion at ten arbitrary points on the surface of the magnetic recording medium using a stylus type surface roughness meter, the height of the convex portion was 10 nm at all measurement points.

<Example 9> A mask pattern was directly formed on the same substrate as in Example 1 in the same manner as in Example 1, and after irradiating the entire surface with an argon ion beam for 10 seconds using an ion milling device, the mask pattern was removed. As a result, regularly arranged convex portions were formed on the surface of the substrate. As a result of measuring the height of the convex portion at ten arbitrary points on the substrate surface using a stylus type surface roughness meter, the height of the convex portion was 10 nm at all measurement points.

An intermediate layer was formed on this substrate in the same manner as in Example 1.

A magnetic layer and a protective layer were formed by sputtering, and a perfluoropolyether lubricant was applied as a lubricant layer on the protective layer to a thickness of about 5 nm to produce a magnetic recording medium.

A stylus type surface roughness meter measures any 10 points on the surface of a magnetic recording medium.
As a result of measuring the height of the convex portion at each measurement point, the height of the convex portion was 10 nm at all measurement points, indicating that the shape of the convex portion formed on the substrate was substantially maintained up to the surface of the magnetic recording medium. confirmed.

FIG. 3 shows a schematic diagram of the cross-sectional structure in the radial direction of the magnetic recording medium of this example.

Comparative Example 1> On the same substrate as in Example 1, an intermediate layer, a magnetic layer, and a protective layer were formed by sputtering in the same manner as in Example 1. A magnetic recording medium was prepared by applying a fluoropolyether lubricant to a thickness of about 5 nm. No convex portions were formed.

Comparative Example 2> The same substrate as in Example 1 was polished by pressing a puff containing abrasive grains without rotating it to form continuous grooves along the circumferential direction. The surface of the substrate thus obtained had an average roughness (Ra) of 10 nm and a maximum roughness (R-ax) of 35 nm as measured using a stylus type surface roughness meter.

An intermediate layer was formed on this substrate in the same manner as in Example 1.

A magnetic layer and a protective layer were formed by sputtering, and a perfluoropolyether lubricant was applied as a lubricant layer on the protective layer to a thickness of about 5 nm to produce a magnetic recording medium.

<Comparative Example 3> On the same substrate as in Example 2, a 0.2 μm thick Cr intermediate layer, 40 nm thick Co-N magnetic layer, and 40 nm thick C protective layer were formed by sputtering. did. While rotating this disc, a puff containing abrasive grains was pressed against it to polish the C protective layer to a thickness of about 1 nm, thereby forming grooves along the circumferential direction. Then, a perfluoropolyether lubricant was applied as a lubricant layer to a thickness of about 5 nm on the surface of the disk to prepare a magnetic recording medium.

The surface of the magnetic recording medium thus obtained had an average roughness (Ra) of 10 nrn and a maximum roughness (
R, ax) was 30 nm.

Comparative Example 4 On the same substrate as in Example 1, a Cr intermediate layer was formed to a thickness of 0.2 μm, a Co-Ni magnetic layer was formed to a thickness of 40 nm, and a C layer was formed as a protective layer to a thickness of 30 nm by sputtering. This disk was reverse sputtered in a sputtering device to form a C protective layer of about 10%
It was etched to a thickness of nm.

A perfluoropolyether lubricant was applied as a lubricant layer to a thickness of about 5 nm on the surface of the obtained disk to prepare a magnetic recording medium.

The surface of the magnetic recording medium thus obtained was measured with a stylus surface roughness meter to have an average roughness (Ra) of 8 nm and a maximum roughness (Rm
ax) l 5 nm.

Comparative Example 5 A magnetic recording medium was produced in the same manner as in Example 1, except that a photomask having concentric circular portions with a width of 2 μm and a pitch of 10 μm so as not to transmit light was used.

The surface of the magnetic recording medium was observed using an electron microscope, and the width was 2μ.
It was confirmed that concentric protrusions with a pitch of 10 μm and a pitch of 10 μm were formed on the entire surface. As a result of measuring the height of the convex portion at 10 arbitrary points on the surface of the magnetic recording medium using STM and a stylus type surface roughness meter, the height of the convex portion at any measurement point was 10n.
It was m. The arrangement of the convex portions in this comparative example is as shown in FIG.

In this example, the area ratio of the convex portions is 20 over the entire surface.
%.

Regarding the magnetic recording media obtained in the above Examples and Comparative Examples, a magnetic disk drive shown in FIG. We conducted an internal appearance inspection within the CSS area, (1) Measurement of adhesion force and frictional force with the magnetic head, (2) Measurement of the minimum guaranteed flying height of the magnetic head, and a magnetic recording/reproduction test. The flying height of the magnetic head during steady rotation is 0.1μ.
I went with m.

Show the test results on the surface work.

As shown in Table 1, in Comparative Example 1 in which no unevenness was formed, the initial attraction force and frictional force were large, and the increase after C3S was also large. For this reason, linear sliding marks were generated on the surface after C8S, and this damage significantly deteriorated the characteristics in the flying characteristics test and the recording/reproducing test.

In Comparative Example 2, in which unevenness was formed on the substrate by a polishing method, the deterioration in characteristics after C8S was smaller than in Comparative Example 1, but there was still considerable deterioration in characteristics, and the flying characteristics were poor even in the initial stage, resulting in errors in recording and reproducing tests. is occurring. This is thought to be because in Comparative Example 2, local protrusions were likely to grow during the polishing process, and it is believed that these areas caused pit-like peeling after C8S. Furthermore, in Comparative Example 2, since the substrate has irregularities, the magnetic layer formed thereon also has irregularities, and the S/N ratio is low even in the initial stage.

In Comparative Example 3 in which unevenness was formed on the protective layer by a polishing method, similar to Comparative Example 2, defects in flying characteristics and errors that were thought to be caused by local protrusions during the polishing process occurred at the beginning.

In Comparative Example 3, since the magnetic layer is almost flat, the initial S/N ratio is higher than in Comparative Example 2, but it is still insufficient. This is because the flying stability of the magnetic head is not sufficient because the shape of the unevenness formed on the protective layer is non-uniform.

Further, the characteristics deteriorated significantly after CSS, and this is considered to be because the flying stability of the magnetic head was further impaired due to the occurrence of peeled parts and the like.

In Comparative Example 4, in which unevenness was formed on the protective layer by reverse sputtering,
Although no errors are observed in the initial stage, the flying characteristics are still insufficient, and the S/N ratio is also slightly low.

This is because, as in Comparative Example 3, the shape of the unevenness formed on the protective layer is non-uniform, so the flying stability of the magnetic head is not sufficient.

In addition, there was considerable characteristic deterioration after C8S, but in order to find out the cause of this, we analyzed the peeled part after C3S and found that the peeling was caused by minute dust biting in. Therefore, it is considered that in Comparative Example 4, the flying stability of the magnetic head was further impaired and the characteristics were deteriorated due to the generation of peeling portions due to the presence of minute dust between the magnetic head and the magnetic recording medium. In addition, in the case of Comparative Examples 2 and 3, when the peeled portions after CSS were analyzed, it was similarly found that there were areas where fine dust had penetrated and peeled off.

Comparative example 5 in which concentric regular convex portions were formed on the protective layer
Although the initial characteristics are good, the characteristics deteriorate significantly after CSS. In order to find out the cause of this, we analyzed the peeled part after C8S and found that fine dust had accumulated around the peeled part, and a part of it got stuck in, causing peeling. Therefore, it is considered that in Comparative Example 5, the flying stability of the magnetic head was impaired and the characteristics were deteriorated.

On the other hand, the magnetic recording medium according to this example shows good characteristics before C8S, and the deterioration of characteristics after C8S is also small. This is because the regular uneven shape formed in this example does not have local protrusions, so the flying stability of the magnetic head is good.

In particular, as in Examples 1 to 8, an intermediate layer, a magnetic layer, and a protective layer are formed on a flat substrate, and minute dust attached to the head or magnetic recording medium is immediately removed from the surface of the protective layer. When a lubricant layer is formed on the protective layer by providing regularly arranged minute irregularities that can be removed, the frictional force and adsorption force with the magnetic head are low, and the recording and reproducing characteristics are good. The flying stability of the magnetic head is guaranteed, and a magnetic recording medium with little deterioration of characteristics over a long period of time can be obtained.

Further, as in Example 9, a fine unevenness having the above effect is provided on the substrate, and an intermediate layer and a magnetic layer are formed thereon.

Even when a protective layer and a lubricant layer are formed, the S/N ratio is slightly lowered from Example 1 to Example 8 due to the unevenness of the magnetic layer, but the size of the unevenness is small. , the amount of decrease in the S/N ratio is small, and other characteristics are good.

As described above, according to this embodiment, by providing the surface of the magnetic recording medium with regularly arranged microscopic irregularities so that microscopic dust attached to the magnetic head or the magnetic recording medium can be quickly removed, It is possible to obtain a magnetic recording medium that has low frictional force and adsorption force with the magnetic head, has good recording and reproducing characteristics, guarantees flying stability of the magnetic head, and has little characteristic deterioration over a long period of time.

〔Effect of the invention〕

According to the present invention, it is possible to provide a magnetic recording medium that has low frictional force and adsorption force with the magnetic head, guarantees flying stability of the magnetic head even at a low flying height, and has good reproducibility with little characteristic deterioration over a long period of time. be able to.

[Brief explanation of drawings]

1, 2, and 3 are perspective views showing a cross-sectional structure in the radial direction of a magnetic recording medium according to an embodiment of the present invention,
FIG. 4, FIG. 5, and FIG. 6 are partial plan views showing the arrangement of convex portions formed on the surface of a magnetic recording medium according to an embodiment of the present invention;
FIG. 7 is a graph showing an example of the results of measuring the convex bottom of a magnetic recording medium according to an embodiment of the present invention in the radial direction using a stylus type surface roughness meter, and FIG. 9, 10, and 11 are plan views showing an example of two distributions of shapes of convex portions on the surface of a magnetic recording medium. Engineering ・Aluminum alloy disc, 2... base layer, 3...
Intermediate layer, 4... Magnetic layer, 5... Protective layer, 6... Lubricating layer, 7... Convex portion, 13... Magnetic disk rotation control means, 14... Magnetic recording medium (magnetic disk) 15・Magnetic Herad. Figure Figure Figure Figure Figure Figure Figure -1 [φ2μm 20 Figure (μm) 0 Figure

Claims (1)

[Claims] 1. At least one magnetic disk having a magnetic layer and a surface protective layer on a substrate, facing the rotating magnetic disk with a small gap,
A magnetic disk device comprising: a magnetic head supported by a slider; a rotating means for rotating the magnetic disk; and a magnetic head positioning means for moving and positioning the magnetic head to a predetermined position on the magnetic disk. . A magnetic disk device characterized in that the surface of the magnetic disk has a large number of flat-surfaced convex portions having the following (a) and (b). (a) The convex portions are divided on the same circumference and the same radius of the magnetic disk, and there are concave portions between the convex portions, and the distance between the closest convex portions of the magnetic disk is 0. .2-5
It is 0 μm. (b) The convex portion is arranged so that when the slider is placed at an arbitrary position on the magnetic disk and the magnetic disk is rotated once, the convex portion comes into contact with the entire surface of the slider. 2. at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate, facing the rotating magnetic disk with a small gap;
A magnetic disk device comprising: a magnetic head supported by a slider; a rotating means for rotating the magnetic disk; and a magnetic head positioning means for moving and positioning the magnetic head to a predetermined position on the magnetic disk. . A disk device characterized in that the surface of the magnetic disk has a large number of convex portions having a flat surface and a substantially constant height as described in (a) and (b) below. (a) The convex portions are divided on the same circumference and the same radius of the magnetic disk, and there are concave portions between the convex portions, and the distance between the closest convex portions of the magnetic disk is 0. .2-5
(b) The convex portion is arranged so that when the slider is placed at an arbitrary position on the magnetic disk and the magnetic disk is rotated once, the convex portion comes into contact with the entire surface of the slider. There is. 3. At least one magnetic disk having a magnetic layer and a surface protective layer on a substrate, facing the rotating magnetic disk with a minute gap of 0.02 to 0.2 μm, and supported by a slider. A magnetic disk device comprising: a magnetic head that rotates the magnetic disk; a rotating means that rotates the magnetic disk; and a magnetic head positioning device that moves and positions the magnetic head to a predetermined position on the magnetic disk. A magnetic disk device characterized by having a large number of convex portions having a flat surface and a substantially constant height, and having the following (a) and (b). (a) The convex portions are divided on the same circumference and the same radius of the magnetic disk, and there are concave portions between the convex portions, and the distance between the closest convex portions of the magnetic disk is 0. .2-5
(b) The convex portion is arranged so that when the slider is placed at an arbitrary position on the magnetic disk and the magnetic disk is rotated once, the convex portion comes into contact with the entire surface of the slider. There is. 4. At least one magnetic disk having a magnetic layer and a surface protective layer on a substrate, facing the rotating magnetic disk with a minute gap of 0.02 to 0.2 μm, and supported by a slider. A magnetic disk device comprising: a magnetic head that rotates the magnetic disk; a rotating means that rotates the magnetic disk; and a magnetic head positioning device that moves and positions the magnetic head to a predetermined position on the magnetic disk. A magnetic disk device characterized in that the layer surface has a flat surface and the surface of the magnetic disk has a large number of convex portions having a flat surface and a substantially constant height, which have the following (a) and (b). . (a) The convex portions are divided on the same circumference and the same radius of the magnetic disk, and there are concave portions between the convex portions, and the distance between the closest convex portions of the magnetic disk is 0. .2-5
(b) The convex portion is arranged so that when the slider is placed at an arbitrary position on the magnetic disk and the magnetic disk is rotated once, the convex portion comes into contact with the entire surface of the slider. There is. 5. In claims 1 to 4, the size of each convex portion is 0.1 μm or more in the radial width of the magnetic disk,
10 μm or less, 0.5 in the circumferential width of the magnetic disk
A magnetic disk device characterized in that the size is greater than or equal to μm and less than or equal to 1 mm. 6. The magnetic disk device according to claim 1, wherein the height of the convex portion is higher than 5 nm and lower than 40 nm, and has a substantially constant height within that range. 7. Claims 1 to 6 are characterized in that an area ratio of the total area of the convex parts per square millimeter within the convex part forming area on the surface of the magnetic disk is 0.1% or more and 80% or more. magnetic disk device. 8. In claims 1 to 7, on the surface of the magnetic disk,
A magnetic disk drive characterized in that the convex portions are regularly arranged so that the deviation of the area ratio of the convex portions on the same circumference is within 20% per square millimeter. 9. A magnetic disk device according to any one of claims 1 to 8, wherein the bottom surface of the recess located between the projections is a substantially flat surface. 10. In claims 1 to 9, the number of the convex portions is 200.
A magnetic disk device characterized in that the number of magnetic disks is at least 250,000 pieces/mm^2 and does not exceed 250,000 pieces/mm^2. 11. The magnetic disk according to any one of claims 1 to 10, wherein the convex portion is arranged so as to be sequentially shifted toward the outer circumferential side with respect to the magnetic head supporting slider when the magnetic disk is rotated. Device. 12. In a magnetic recording medium comprising at least a magnetic layer and a surface protective layer on a substrate made of a non-magnetic disk, the surface protective layer has a large number of convex portions with a flat surface comprising the following (a) and (b). A magnetic recording medium characterized by comprising: (B) The convex portions are divided on the same circumference and the same radius, and there are concave portions between the convex portions, and the distance between the closest convex portions is 0.2 to 50 μm, ( (b) The protrusions are arranged so that when the magnetic head supporting slider is placed at an arbitrary position on the surface protective layer and the substrate is rotated once, the protrusions come into contact with the entire surface of the slider. 13. In a magnetic recording medium comprising at least a magnetic layer and a surface protective layer on a substrate made of a non-magnetic disk, the surface protective layer has a large number of flat and substantially constant surfaces comprising the following (a) and (b). A magnetic recording medium characterized by having a convex portion having a certain height. (B) The convex portions are divided on the same circumference and the same radius, and there are concave portions between the convex portions, and the distance between the closest convex portions is 0.2 to 50 μm, ( (b) The protrusions are arranged so that when the magnetic head supporting slider is placed at an arbitrary position on the surface protective layer and the substrate is rotated once, the protrusions come into contact with the entire surface of the slider. 14. A magnetic recording medium comprising at least a magnetic layer and a surface protective layer on a substrate made of a non-magnetic disk, the surface protective layer comprising a lubricating layer and a protective layer located below the surface protective layer. A magnetic recording medium comprising a large number of convex portions having a flat surface and a substantially constant height, and having the following (a) and (b). (B) The convex portions are divided on the same circumference and the same radius, and there are concave portions between the convex portions, and the distance between the closest convex portions is 0.2 to 50 μm, ( (b) The protrusions are arranged so that when the magnetic head supporting slider is placed at an arbitrary position on the surface protective layer and the substrate is rotated once, the protrusions come into contact with the entire surface of the slider. 15. A magnetic recording medium according to claims 12 to 14, wherein the surface of the magnetic layer is a flat surface, and the protrusion is provided on the surface protective layer. 16. A magnetic recording medium according to claims 12 to 14, wherein the convex portion is provided on the surface of the magnetic layer, and the shape of the convex portion is maintained up to the surface protective layer. 17. The magnetic recording medium according to claim 14, wherein the protrusion is provided on the surface of the protective layer, and the shape of the protrusion is maintained up to the lubricant layer thereon. 18. Claims 12 to 17, wherein the size of each convex portion is 0.1 μm or more in width in the radial direction of the substrate, and 10
μm or less, 0.5 μm or more in width in the circumferential direction of the substrate, 1 m
A magnetic recording medium characterized in that the magnetic recording medium is less than m. 19. In claims 12 to 18, the height of the convex portion is 5.
A magnetic recording medium characterized in that it has a height that is higher than 40 nm and lower than 40 nm, and that is approximately constant within that range. 20. Claims 12 to 19 are characterized in that an area ratio of the total area of the protrusions per square millimeter within the protrusion formation region on the surface of the surface protective layer is 0.1% or more and 80% or less. magnetic recording media. 21. In claims 12 to 20, the protrusions are regularly arranged on the surface of the surface protective layer so that the deviation of the area ratio of the protrusions on the same circumference is within 20% per square millimeter. A magnetic recording medium characterized by: 22. A magnetic recording medium according to any one of claims 12 to 21, wherein the bottom surface of the recess between the projections is a substantially flat surface. 23. In claims 12 to 22, the number of the convex portions is 2.
00 pieces/mm^2 or more, 250,000 pieces/mm^
A magnetic recording medium characterized in that the magnetic recording medium does not exceed 2. 24. Claims 12 to 23 provide that when the magnetic recording medium is rotated, the convex portions are arranged so as to be sequentially shifted toward the outer circumferential side with respect to a magnetic head supporting slider positioned above the magnetic recording medium. Features of magnetic recording media. 25. A substrate for a magnetic recording medium comprising a non-magnetic disc, comprising a number of convex portions with a flat surface comprising the following (a) and (b) on the substrate, and the height of the convex portions is 5 nm or more. , 4
1. A substrate for a magnetic recording medium, having a height of 0 nm or less and a substantially constant height within that range. (a) The convex portions are divided on the same circumference and the same radius, there are concave portions between the convex portions, and the distance between the closest convex portions is 0.2 to 50 μm; (b) The convex portion is arranged so that when the magnetic head supporting slider is placed at an arbitrary position on the substrate and the substrate is rotated once, the convex portion comes into contact with the entire surface of the slider. 26. In claim 25, the area ratio of the total area of the protrusions per square millimeter within the protrusion forming region on the surface of the substrate is 0.1% or more and 80% or less, and on the same circumference. A substrate for a magnetic recording medium, characterized in that the convex portions are regularly arranged so that a deviation in the area ratio of the convex portions is within 20% per square millimeter. 27. In claim 25 or 26, the size of each convex portion is 0.1 μm or more in width in the radial direction of the substrate, and 1 μm or more.
0 μm or less, 0.4 μm or more in width in the circumferential direction of the substrate, 1
mm or less, and the number of the protrusions is 200 pieces/mm^
2 or more and 250,000 pieces/mm^2 or less. 28. On a substrate consisting of a non-magnetic disk with a flat surface,
In a method for manufacturing a magnetic recording medium comprising at least a magnetic layer and a surface protective layer, and a lubricating layer and a protective layer below the protective layer as the surface protective layer, a mask pattern is formed on the surface of the lower protective layer; After etching the layer according to the mask pattern within the film thickness range, the mask pattern is removed to form the protrusion according to claim 13, and then the lubricant layer is formed thereon. A method of manufacturing a magnetic recording medium, characterized in that: 29. On a substrate consisting of a non-magnetic disk with a flat surface,
A method for producing a magnetic recording medium comprising at least a magnetic layer and a surface protective layer, and a lubricating layer and a protective layer thereunder as the surface protective layer, including forming a mask pattern on the surface of the lower protective layer by lithography technology. , by etching the protective layer according to the mask pattern within the range of its film thickness and then removing the mask pattern, the protrusion according to claim 13 is formed, and then the lubricant layer is etched thereon. 1. A method of manufacturing a magnetic recording medium, comprising: forming a magnetic recording medium. 30. On a substrate consisting of a non-magnetic disk with a flat surface,
A method for producing a magnetic recording medium comprising at least a magnetic layer and a surface protective layer, and a lubricating layer and a protective layer thereunder as the surface protective layer, wherein a beam of light, a laser, or a charged particle is applied to the surface of the lower protective layer. Claims can be made by forming a film of a substance that can be cured by irradiation, selectively irradiating the surface of the film with a beam of light, laser, or charged particles to partially cure it, and then removing the uncured portion. 14. A method for manufacturing a magnetic recording medium, comprising forming the convex portion according to item 13, and then forming the lubricant layer thereon. 31. On a substrate consisting of a non-magnetic disk with a flat surface,
In a method of manufacturing a magnetic recording medium by forming at least a magnetic layer and a surface protective layer, and forming a lubricating layer and two protective layers below the lubricating layer as the surface protective layer, after forming the two protective layers, the surface By forming a mask pattern on the surface of the first protective layer, etching the second protective layer corresponding to the upper layer according to the mask pattern, and removing the mask pattern, the surface of the first protective layer is etched. A method of manufacturing a magnetic recording medium, comprising forming the convex portions described in .