JP3050998B2 - Magnetic disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk in which a magnetic head levitates and travels, and more particularly, to prevent a magnetic head from being started poorly due to an adsorption phenomenon, improve friction characteristics, and obtain stable electric characteristics. The present invention relates to a magnetic disk in which

[0002]

2. Description of the Related Art Generally, a magnetic recording device such as a flexible disk device (FDD) or a hard disk device (HDD) is frequently used as an external device such as a computer. These FDDs, HDDs, and the like include a magnetic head for recording, reproducing, and erasing information, and a magnetic disk that moves relative to the magnetic head and records predetermined information at a desired position. It is installed. In a disk-shaped magnetic disk used in a magnetic recording device of a computer, a magnetic head reads and writes signals. When the magnetic disk is stopped, the magnetic head comes into contact with the surface of the magnetic disk, and when the magnetic disk rotates, the magnetic head floats by the buoyancy due to the principle of gas bearings, and in this state the signal is written and read. An operation referred to as so-called CSS (contact start / stop) is performed.

Therefore, a magnetic recording apparatus composed of a magnetic disk and a magnetic head as described above reduces the flying height of the magnetic head with respect to the magnetic disk, that is, reduces spacing loss to achieve higher density recording. Is required. Therefore, conventionally, high flatness and smoothness have been required for a magnetic disk, while flying stability is required for a magnetic head, and in order to maintain good flying stability, the flat surface of the medium facing surface is required. Degree and smoothness have been required. Therefore, in the magnetic disk and the magnetic head in the conventional magnetic recording apparatus, the medium facing surface is mirror-finished. However, the above-mentioned mirror-finished magnetic disk surface and the medium facing surface of the magnetic head have a problem that a strong adsorption phenomenon occurs due to the lubricant on the medium facing surface of the magnetic disk and the magnetic head and moisture in the atmosphere. Had. And
If such an attraction phenomenon occurs and the attraction force between the magnetic head and the magnetic disk exceeds the torque force of the drive rotation motor of the magnetic recording apparatus, there is a risk that startup failure may occur.

Therefore, in order to solve the above-mentioned problems, a method of providing roughness on the surface of the magnetic head facing the medium has been adopted in some cases. However, in many cases, the surface of the magnetic disk has a texture. It is common to provide a groove in the circumferential direction called a so-called "circumferential groove" to prevent suction. For example, a technique for providing a spiral groove (JP-A-1-140422) and a technique for providing concentric grooves are known.

Here, the structure of a conventional general magnetic disk will be described with reference to the drawings. FIG. 32 (a)
FIG. 32B shows an example of a conventional magnetic disk. This magnetic disk 10 has a disc-shaped substrate 2 made of Al, Al alloy, glass, or the like, having a through hole 1 formed in the center, and A magnetic disk substrate C composed mainly of a coating film 3 of Ni-P or the like coated on the entire surface of the substrate 2 is mainly used. On the coating film 3 of the magnetic disk substrate C, a laminated film shown in FIG. Is formed. As an example of the laminated film formed on the Ni—P coating film 3, a configuration shown in FIG. 32B can be adopted. In FIG. 32B, the laminated film includes a Cr film 4 having a thickness of about 1500 °, a Co—Ni layer having a thickness of about 700 ° formed on the Cr film 4, and a Co—Ni layer.
A magnetic layer 5 made of a -Cr, Co-Cr-Ta layer, etc., a protective film 6 made of C having a thickness of about 300 ° laminated on the magnetic layer 5, and a lubricating film 7 coated on the protective film 6. It is composed of

Further, a process for forming a texture is performed on the coating film 3 made of Ni-P or the like.
Texture 8 is provided. This texture 8
Generally, a large number of concavo-convex groove-shaped rings are formed on the upper surface of the coating film 3 in a concentric manner with the maximum height Ra of the surface roughness from the roughness center line being 0.002 to 0.1 μm. It is. Therefore, the magnetic layer 4 laminated on the texture 8
On the surface of the protective film 5, an uneven groove having a shape matching the uneven groove of the texture 8 is formed.

[0007] As an example of the texture processing method, there is a method in which a polishing tape with specially adjusted abrasive grains is pressed against a substrate rotating at a constant angular speed with an appropriate pressure. The texture 8 formed by the above-described method has two effects, namely, the effect of preventing the magnetic head from sticking between the medium facing surface and the surface of the magnetic disk, and the effect of obtaining magnetic anisotropy. The texture 8 having the two effects has an advantage that it can be achieved by processing under the same conditions simultaneously in one step of the above-described texture processing. Therefore, the effect of reducing the attraction phenomenon between the medium facing surface of the magnetic head and the surface of the magnetic disk due to the texture 8 provided on the substrate of the conventional magnetic disk having the above configuration is in contact with the magnetic disk. The adsorption phenomenon is avoided by reducing the contact area between the magnetic head in the state and the surface of the magnetic disk.
Further, in addition to the above-mentioned effects, the texture 8 gives magnetic anisotropy to the magnetic film 4 coated on the surface thereof, and has a high coercive force in the circumferential direction which is convenient for magnetic recording. In addition, it is possible to provide a magnetic disk having excellent resolution and low DC erasing noise.

Therefore, as described above, the texture 8 prevents the magnetic head from sticking to the medium facing surface and the surface of the magnetic disk in the CSS operation, and increases the coercive force using magnetic anisotropy for high-density recording. It has two functions; a rough texture is preferable to prevent the magnetic head from sticking to the medium facing surface and the surface of the magnetic disk, and a fine and uniform texture is required to obtain the flying stability of the magnetic head. It is preferred. And
The stopped state and the flying state of the magnetic head will be described in detail below. When the magnetic disk is started, the magnetic head is pressed against the surface of the magnetic disk by the spring pressure of the spring plate member supporting itself. When the magnetic disk starts rotating from this state, the magnetic head slides while being in contact with the rotating magnetic disk.

Next, as the rotational speed of the magnetic disk increases, an air flow flows between the medium facing surface of the magnetic head and the surface of the magnetic disk to form an air rigid film and lift the magnetic head. When this force overcomes the spring pressure on the magnetic head, the magnetic head gently flies from the surface of the magnetic disk, and maintains the magnetic height while maintaining the flying height determined by the shape of the magnetic head, the spring pressure, and the peripheral speed of the magnetic disk. Levitating with respect to the disk. That is, the magnetic head slides over the surface of the magnetic disk while being held down by the spring pressure from the start of rotation of the magnetic disk to the start of floating of the magnetic head. For this reason, conventionally, the surface of the magnetic disk or the medium facing surface of the magnetic head is worn, and in some cases, the frictional force is abnormally increased, causing the magnetic disk surface to be destroyed (crash), and the recorded contents of the magnetic disk can be read. Sometimes disappeared. If the frictional force between the magnetic head and the magnetic disk abnormally rises to a value equal to or higher than the rotational torque of the magnetic disk, the magnetic disk will no longer rotate, which may lead to failure of the magnetic recording device. Therefore, the texture 8 is preferably a coarse texture for the purpose of reducing the adsorption phenomenon, and fine for obtaining a stable electromagnetic property, and
It can be seen that a uniform texture is preferred.

[0010]

However, in recent years, as the development of magnetic recording devices with higher performance has progressed, the flying height of magnetic heads has been reduced in order to achieve higher density recording. In order to cope with this, the miniaturization and uniformity of the texture on the magnetic disk have become indispensable factors, and there have been remarkable advances in the technology for fineness and uniformity of the texture. The miniaturization and uniformization of such textures promotes the phenomenon of attraction between the surface of the magnetic disk and the medium facing surface of the magnetic head, making it more difficult and more difficult to reduce the phenomenon of attraction between the surface of the magnetic disk and the medium facing surface of the magnetic head. Had the problem of doing so.

Therefore, in order to avoid such a problem,
The present inventors filed a patent application for a magnetic disk as shown in FIG. 31 on June 3, 1992 in Japanese Patent Application No. 4-143008. The magnetic disk D is provided with a plurality of protruding portions 11 using photolithographic etching or the like at a portion other than the portion where the magnetic head is flying and flying, that is, at a portion where a CSS operation is performed (hereinafter, referred to as a CSS region 11a). Part where recording and reproduction are performed (hereinafter referred to as data area 12a)
And a fine and uniform texture 12 is provided.

Such a magnetic disk can cope with a low flying height of the magnetic head to some extent. However, in the boundary area between the CSS area 11a and the data area 12a, there is a considerable difference between the heights of the protruding portions 11 and the textures 12, so that a difference is formed.・ CSS area 11 provided with
Also in a, since the magnetic head runs at a low flying height,
When the magnetic head travels in this boundary region, there is a problem that it is difficult to maintain the flying stability.

The formation density of the protruding portions 11... Formed in the CSS area 11a is optimized to optimize the attraction between the magnetic head and the magnetic disk and the sliding resistance. It was unclear by the above invention.

Therefore, the magnetic disk of the present invention has been made in view of the above-mentioned problems, and in the case where the magnetic head of the magnetic disk is in the CSS area, it is possible to reduce the adsorption phenomenon between the medium facing surface of the magnetic head and the magnetic disk surface. The magnetic head enables low flying, and the data area of the magnetic disk ensures stable recording / reproducing characteristics without damaging the surface of the magnetic disk and the medium facing surface of the magnetic head. It is intended to provide a magnetic disk capable of low flying height.

[0015]

The magnetic disk according to claim 1 Means for Solving the Problems In order to solve the above problems, reading and writing of information is performed by the magnetic head, when it is rotated together
In a magnetic disk in which a magnetic layer, a protective layer and a lubricating layer are coated on a substrate , a CSS for floating a magnetic head on at least one of the front surface and the back surface of the substrate of the magnetic disk
Projecting portion projecting on the inner peripheral side corresponding to the region is a large number, the cardiac circular or spiral grooves formed on the outer <br/> peripheral portion corresponding to the data area for recording and reproducing data And corresponds to a CSS area on the magnetic disk.
The height of the protruding portion provided on the inner peripheral portion is 5 nm or more and 80 n.
m and the height of the protruding portion is H (mm), 1 mm ²
When the number of the projecting portions per contact is N, each projecting portion is
The average area A (mm ² ) of (10 ⁻⁵ / N · H) ² ≦ A
Range near Rukoto of ≦ 15 × 10 ^-2 / N and said.

According to a second aspect of the present invention, there is provided a magnetic disk, wherein the density of the protruding portions according to the first aspect is reduced.
Note that the range was 111 to 11100 pieces / mm ^2.
Sign.

[0017]

[0018]

[0019]

[0020]

The magnetic disk of the present invention is divided into two parts, a part for performing a CSS operation and a part for performing recording and reproduction.
The portion for performing the CSS operation is provided on the inner peripheral portion of the magnetic disk, which is disadvantageous for a magnetic recording device having a low peripheral speed of the magnetic disk and a small output signal, and the portion for performing recording and reproducing is provided on the outer peripheral portion of the magnetic disk.

According to the magnetic disk according to the first aspect of the present invention, by providing a plurality of protruding portions in the CSS area on the inner peripheral side thereof, during rotation of the magnetic disk, between the protruding portions. A positive pressure region is generated, and an airflow resulting from the region is generated. Then, this air current acts on the magnetic head, and causes the magnetic head to fly quickly. An airflow is generated by rotation even in a normal magnetic disk having no protrusion, but in a magnetic disk having a protrusion, a positive pressure generated due to an air compression effect between the protrusions at the start of rotation. As a result, a strong airflow can be immediately generated, and the magnetic head flies faster than before. Therefore, the time when the magnetic head comes into contact with the magnetic disk at the start of rotation of the magnetic disk and rubs it is shortened,
The risk of damage to the magnetic disk is reduced. Furthermore, by keeping the height of the projections constant, the flying stability of the magnetic head can be more reliably ensured.

When the magnetic head is in contact with the CSS area of the magnetic disk when the magnetic disk is stopped, the magnetic head is moved through the plurality of projecting portions formed on the CSS area. Contact Then, since the conventional mirror-to-mirror contact is eliminated, the phenomenon that the magnetic head is attracted to the magnetic disk does not occur. Therefore, the failure of the magnetic recording device which has conventionally occurred due to the magnetic head adsorption phenomenon does not occur.

Further, by providing concentric or spiral grooves in the data area, it is possible to reduce the difference in height from the protruding portions formed in the CSS area. In this way, it is possible to reduce the difference in the boundary between the CSS area and the data area, which has been regarded as a problem of the magnetic disk having the texture formed thereon, and to fly the magnetic head at the boundary between the CSS area and the data area. It is possible to ensure the stability. Therefore, stable magnetic recording characteristics can be guaranteed .

Further, when a texture is used in the data area as in the prior art, it is difficult to adjust the surface roughness of the texture, and there is a problem that a head crash or the like occurs during the floating operation of the magnetic head. However, in the magnetic recording apparatus according to the present invention, since a concentric or spiral groove is formed in the data area of the magnetic disk, problems such as head crash can be avoided. Further, the magnetic film of the magnetic disk is not limited to a magnetic film that does not require magnetic anisotropy, and a magnetic film that requires magnetic anisotropy can be used, and the coercive force required for a magnetic recording device can be reduced. It is possible to get.

[0025]

[0026]

Under the above conditions, the above C
When the height of each projecting portion in the SS region and each projecting portion pattern in the data region is H (mm), and the number of the projecting portions per 1 mm ² is N, the average area A of each projecting portion is shown. (Mm ² )
^Is formed within the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N, whereby the flying stability of the magnetic head is extremely excellent with respect to the surface area of the medium facing surface of the magnetic head. That is, the magnetic recording characteristics can be maintained and stable magnetic recording characteristics can be achieved.

[0028]

[0029]

[0030]

Therefore, according to the magnetic disk of the present invention,
In the CSS area on the inner peripheral side, the suction and sliding resistance (frictional force) with the magnetic head can be reduced,
The durability is improved by the CSS, and in the data area on the outer peripheral side, the flying stability of the magnetic head flying and flying over the data area can be improved, and the magnetic head can be further lowered. . Further, since the height can be adjusted in the boundary region between the CSS region and the data region, the difference in the boundary region can be reduced, and the flying stability of the magnetic head traveling on the boundary region can be improved. In addition, stabilization of magnetic recording characteristics can be guaranteed.

[0032]

The first embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows Embodiment 1 of a magnetic disk employing the structure of the present invention. The magnetic disk 20 of this example has a configuration in which a magnetic film, a protective film, or a plurality of intermediate films as needed are coated on the surface or both front and back surfaces of a disk-shaped substrate A made of metal, glass, or resin. It is used as a magnetic recording medium such as a magnetic recording device of a computer.

Therefore, the magnetic disk 20 according to the first embodiment of the present invention will be described. In the magnetic disk according to the first embodiment, a predetermined area on the radially inner side shown in FIG. 1 is a CSS area 21a, and a predetermined area on the radially outer peripheral side of the CSS area 21a is a data area 22a.

The magnetic disk 20 of the first embodiment is
In the CSS region 21a, protruding portions 21 having a height of 5 nm or more and 80 nm or less are provided, and in the data region 22a, concentric grooves 22 having a height of 5 nm or more are provided.
The height of each of the projecting portions 21 and the grooves 22 is H (mm), and the number of the projecting portions 21 per 1 mm ² is N.
, The average area A of the projecting portions 21.
(Mm ² ) is within the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N, and the data area 22 a
Are provided with a height of 5 nm or more, and the total area of the grooves 22.
Outer peripheral data area 2 of the magnetic disk which is the formation substrate of
It is designed to be 15% or less of the total area of 2a.

In the magnetic disk 20 of the first embodiment, the total area of the grooves 22... Must be 15% or less of the total area of the data area 22a. The height of the protruding portions 21... And the groove 22 in the CSS area and the data area is H
(Mm) Assuming that the number of the projecting portions per 1 mm ² is N, the average upper area A (m
m ² ) is equivalent to the definition of the formation density of the protruding portions 21... satisfying (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N. Defined protruding part 21 ...
Are formed as a continuous shape of the grooves 22..., And this is expressed by the area of the protruding surface with respect to the area of the formation region, and the protruding surface of the groove 22. It is 15% or less with respect to the entire area.

A method of manufacturing the magnetic disk 20 having the above-described configuration will be described with reference to FIGS. In order to manufacture the magnetic disk 20 of the first embodiment, a disk-shaped substrate 23 made of Al, an Al alloy, glass, or the like is prepared, and the substrate 23 is chamfered or surface-processed. A coating film 24 such as -P is formed as shown in FIG.

Next, the surface of the coating film 24 is polished at the stage shown in FIG. In this step, in the CSS region 21a on the surface of the coating film 24, the projecting portions 21A having the above-described shape are formed. The data area 22
a has concentric grooves 22A.
.. are formed. And the grooves 22A... Are formed by a photolithography technique including the steps shown in FIG.

Therefore, the projecting portions 21 and the grooves 22 are formed by the photolithography technique shown in FIG.
The method for forming (1) will be described in detail below. First,
As shown in FIG. 3B, a photoresist 29 is placed on the upper surface of the covering film 24, and the CSS region 21a and the data region 22a are provided thereon with the protrusions 21. A photomask 30 with a large number of cutouts is placed as shown in FIG. Then, after exposing this to light including ultraviolet rays, by developing,
.. Are formed as shown in FIG. 3 (d) and are etched as shown in FIG. 3 (e), and then the photoresist is peeled off as shown in FIG. 3 (f). By performing the processing, the magnetic disk substrate A is formed. The photoresist 29 shown in FIG. 3 when describing the method of forming the projecting portions 21 and the grooves 22 is an example of a positive type. However, the photoresist 29 shown in FIG. Is also good. At this time, the photomask 30 placed on the upper surface of the resist 29 is opposite to the positive type, and
The photomask 30 is left only in the shape portion of FIG.

Next, FIG.
A base film 25 made of Cr or the like as shown in FIG. Further, Co-Ta is formed on the underlayer 25.
A magnetic film 26 made of a Cr film or the like is coated as shown in FIG. 2E by means such as sputtering, and a protective film 27 made of carbon or the like is further formed by a means such as sputtering as shown in FIG.
Then, the magnetic disk 20 is completed by forming a film as shown in FIG.

In the manufacturing method, the projecting portions 21A... And the grooves 22A... Are formed after the polishing shown in FIG. 2B, so that each film formed thereon is .. And groove 22A.
..Cover of the surface of magnetic disk 20 as a result of being coated on
In the SS area 21a and the data area 22a, projecting portions 21 and grooves 22 are formed in the same shape as the projecting portions 21A and grooves 22A.

In this embodiment, the projecting portions 21A... And the grooves 22A... Are formed during the lamination of many films.
Is performed after the formation of the protective film 27 in the final step, and the protrusions 21... And the grooves 22... Having the above-described shapes are formed in the CSS region 21a and the data region 22a on the upper surface of the protective film 27. You may. In this case, the protective film 2
7 are provided on the inner peripheral side CSS region 21a on the upper surface of the base 7.
Are formed, and a stamper in which a large number of the grooves 22 are formed is pressed against the outer peripheral side data area 22a, and a large number of the projecting portions 21 and the grooves 22 are formed at once. May be transferred. If the protective film 27 is a hard film, a step of forming a new intermediate film is incorporated before the step of forming the protective film 27, and the projecting portions 21... And the grooves 22 are formed, and the protruding portions 21.
Can be formed at once. And furthermore,
The protruding portions 21... And the grooves 22... May be formed by an appropriate processing method such as electric discharge machining, laser machining, or the like, in addition to the photo-etching as described above. is not.

The height H of the projecting portion 21 provided in the CSS area 21a on the inner peripheral portion of the magnetic disk 20 is set to 5
nm or more. The reason is based on the following test data. (Test Example 1) CSS of inner side of magnetic disk 20
The following test was performed to define the lower limit of the height H of the projecting portion 21 provided in the region 21a. First, as the magnetic disk, the glass substrate A 'is subjected to photoetching to form prism-shaped protruding portions 21' in a regular triangular arrangement such that the mutual distance L is equal as shown in FIG. As shown in FIG. 5, an underlayer 25 'made of Cr, a magnetic layer 26' made of a Co alloy, and a protective layer 27 'made of C are sequentially provided on the glass substrate A' as shown in FIG. By forming a lubricating layer 28 'having a thickness of 1 nm, the average surface area 9
A magnetic disk was manufactured by forming a protruding portion 21 ′ of μm ² (9 × 10 ⁻⁶ mm ² ) in the shape of a prism. And this projecting part 2
The height H ′ of 1 ′ was used as a parameter.

As the magnetic head, a mini monolithic type ferrite head was used. Then, it is mounted on the HDD using the magnetic disk 20 'and the magnetic head,
A drive mounting CSS test was performed and the magnetic disk 20 '
An experiment was conducted to investigate the relationship between the height H 'of the protruding portion 21' and the friction coefficient with respect to the sliding resistance between the magnetic head and the magnetic head. FIG. 6 shows the test results. As for the friction coefficient, the static friction coefficient is obtained by dividing the starting torque of the magnetic disk 20 'by the radius of the magnetic disk 20', and the dynamic friction coefficient is calculated by the inertia method from the rotation falling profile of the magnetic disk 20 '. I asked. Those that achieved 30,000 CSS operations were indicated as “passed” and those that did not achieve were indicated as “failed”. The drive start conditions of the HDD used in Test Example 1 were set to a friction coefficient of 1.2 or less.

As is clear from FIG. 6 showing the test results, the height H 'of the protruding portion 21' which satisfies the friction coefficient of 1.2 or less in the HDD drive starting condition and is "passed".
Is 5 nm, and it has been found that when the height H ′ of the projecting portion 21 ′ is 5 nm or less, it does not function as a projecting portion.

The upper limit of the height H 'of the projecting portion 21' is determined by the restriction of the flying height of the magnetic head required for obtaining the electromagnetic conversion characteristics. Generally, it is sufficient if the dot height is lower than the flying height of the magnetic head, but in practice, it is lower than the flying height. Therefore, the following test was performed to determine the upper limit of the height H ′ of the projecting portion. (Test Example 2) First, several types of magnetic disks having the same configuration as that of the magnetic disk used in the above Test Example 1 and having different heights H 'of the protruding portions 21' provided on the inner peripheral side. Discs 20 ′... Were prepared. Then, the magnetic head of the mini monolithic type having the AE sensor mounted thereon is levitated above the magnetic disk 20 ′..., And when the flying height is gradually reduced, the magnetic head and the magnetic disk 2
0 ′... Are in contact with each other, and the flying height when the AE signal is generated is defined as the flying height. The flying height and the height H ′ of the protruding portion 21 ′ are measured. FIG. Indicated.

As a result of the test described above, the projecting portion 21 ′
When the height H ′ was 100 nm or more, the flying attitude of the magnetic head fluctuated, and stable flying was not obtained. Then, as shown in FIG.
When the height H 'of 1' was 80 nm or less, the magnetic head stably floated. In other words, the above results are not
It can be said that the lower the height H 'of 1', the lower the flying height of the magnetic head.

Therefore, it can be seen from Test Examples 1 and 2 that the height H of the protruding portion 21 provided in the inner peripheral side CSS region 21a of the magnetic disk 20 is appropriately 5 nm or more and 80 nm or less. If the thickness is less than 5 nm, it is not possible to prevent the magnetic head from sticking to the surface of the projecting portion 21 provided in the inner peripheral CSS region 21a of the magnetic disk 20, and if the thickness is more than 80 nm, the flying stability of the magnetic head cannot be maintained. That is, it is difficult to cope with the low flying height of the magnetic head.

As is clear from Test Examples 1 and 2,
In the magnetic disk 20 of the first embodiment, the magnetic disk 2
The height H of the protruding portion 21 provided in the inner peripheral portion CSS region 21a and the data region 22a is set to 5 nm or more, more preferably 80 nm in order to maintain the flying stability of the magnetic head.
By performing the following, the magnetic disk 20 of the first embodiment is
Can maintain the flying stability of the magnetic head and can cope with the low flying of the magnetic head.

The relationship between the height H of the projecting portion 21 provided in the CSS region 21a and the average area A of the projecting portion 21 will be described with reference to FIGS. . FIG. 8 shows an ideal shape of the projecting portion 21,
FIG. 9 is a diagram showing the bearing curve and its amplitude distribution, and FIG. 9 is a diagram showing a shape of a projecting portion 210 of a configuration example in which the ideal projecting portion 21 is slightly deformed, its bearing curve and its amplitude distribution diagram. FIG. 3 is a top view of the configuration of the projecting portion 210 and a diagram showing an average area of the projecting portion 210;
FIG. 10 is a diagram showing the shape of a conventional texture, its bearing curve, and its amplitude distribution for comparison with these.

The C on the inner peripheral side of the magnetic disk 20 of the present invention
The relationship between the height H of the projecting portion 21 provided in the SS region 21a and the average area A of the projecting portion 21 is the same as that of the ideal projecting portion 21 having a rectangular cross section shown in FIG. When represented by the bearing curve shown in (b) and the amplitude distribution shown in FIG. 8 (c), the height of the peak of the amplitude distribution, that is, the peak height of the average amplitude distribution is determined by the The height H, and the area when the upper surface of the projecting portion 21 is a perfect plane at the average height is the average upper area A of the projecting portion 21, and is formed to be equal to or greater than the average height of the projecting portion 21. The change in the area due to the fine unevenness or the like is not considered as the average area A of the projecting portion 21.

Therefore, according to the above definition, FIG.
In addition, in a configuration example of the protruding portion 210 showing the cross-sectional shape, the bearing curve and the amplitude distribution are as shown in FIGS. 9B and 9C. The height H of the projecting portion 210 in this configuration example is the distance h between the peaks of the upper and lower amplitude distributions in FIG. 9C. Further, since the projecting portion 210 has fine irregularities formed on the surface thereof as shown in FIG. 9A, the contact portion of the surface with the magnetic head is formed by the projecting portion 210. formed on the upper surface
The sum of the contact area of only the protrusions of the irregularities is the sum of the surface areas of the irregularities formed on the upper surface of the protruding portion 210 shown in FIG. ,
When the average area A of the projecting portion 210 is defined, FIG.
As shown in the shaded area in (d), in which the area of the horizontal section in the average height H of the projecting portion 210 and the average on the area A of the projecting portion 210.

Further, FIG. 10A shows the general shape of the texture, FIG. 10B shows the bearing curve thereof, and FIG. 10C shows the amplitude distribution thereof.
21 is described as a comparative example of data for the protruding portion. As is clear from FIG. 10C, there is only one peak of the amplitude distribution in the texture, and the characteristics are completely different from those of the protrusions 21 and 210 described above. The texture is not regarded as a part of the protruding portions 21 and 210 even if the protruding portions 21 and 210 are defined in a broad definition.

Therefore, the height H of the protrusion 21 formed in the CSS area of the magnetic disk 20 of the present embodiment as described above is set to 5 nm or more in the CSS area 21a, and the height H of each protrusion 21 is set. Where H (mm) and the number of the projecting portions 21 per 1 mm ² are N,
The reason why the average area A (mm ² ) of 1 is within the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N will be described below. The reason why the formation density of the projecting portion 21 is defined as above is based on test data of Test Examples 3 to 5 as described below. Test Examples 3 to 5 will be described.

(Test Example 3) First, as a magnetic disk, a glass substrate A 'was subjected to photo-etching with the same configuration as the magnetic disk 20' of Test Examples 1 and 2 above, and FIG.
Are formed in a regular triangular arrangement so that the distance L between them is equal to each other, and a base layer 25 'made of Cr is formed on the glass substrate A'. , C
o alloy-based magnetic layer 26 was a material to provide a ', a protective layer 27 which is a material C' in this order, further forming a lubricant layer 28 'having a thickness of 0.5 nm, 80 nm height H (80 × 10 ^{- 6} m
m) and two types of magnetic disks 2 provided with respective 30 nm (30 × 10 ⁻⁶ ) prismatic protrusions 21 ′.
0 ′... Were produced. And the magnetic disk 2
The number N of the projecting portions 21 'at 0' and the average area A thereof were used as parameters.

As the magnetic head, a mini monolithic type ferrite head was used. Then, using the magnetic disk 20 'having the above-described structure and the magnetic head, the number N of the projecting portions 21 of the magnetic disk 20' and the average area A
A test was conducted to investigate the relationship between the pressure and the adsorption force. The attraction force is a force when the magnetic head is separated from the magnetic disk 20 'in a vertical direction perpendicular to the contact surfaces, and is a value in an initial state before the CSS operation is performed.
Then, 0.5 g or more was evaluated as a large adsorption force, and less than 0.5 g was evaluated as a small adsorption force.

FIG. 11 shows a suction force measuring device 50 used in Test Example 3, and FIG. 12 shows the number N of the projecting portions 21 ′ when the height H of the projecting portions 21 ′ is 80 nm. FIG. 13 shows the results of Test Example 3 showing the relationship between the average upper area A and the attraction force. FIG. 13 shows the number N of the protrusions 21 ′ and the average when the height H of the protrusions 21 ′ was 30 nm. The results of Test Example 3 showing the relationship between the upper area A and the attraction force are shown.

An outline of a method of measuring the attraction force by the attraction force measuring device 50 will be described below with reference to FIG.
First, the magnetic disk 20 'is mounted and fixed on a predetermined sample table 51. Then, a load cell for load measurement and an appropriate connection material 64 such as a wire are provided at a predetermined position of the CSS area 21′a of the magnetic disk 20 ′ fixed to the sample table 51.
Is brought into contact with the magnetic head 52 by the predetermined contact force. The contact force between the magnetic head 52 and the magnetic disk 20 ′ is caused by operating a micro feed 54 such as a micrometer head disposed on the fine moving table 53, and the load applying member fixed to the vertical moving member 55 of the fine moving table 53. 56
Is moved in the vertical direction indicated by the double-headed arrow W in the figure. Thereafter, the load applying member 56 is moved to the magnetic head 5.
Then, the load cell 57 is moved in the direction indicated by the arrow V in the drawing in this state, so that the magnetic head 52 is moved from the magnetic disk 20 ′ in a predetermined direction perpendicular to the mutual contact surface. Separate at speed. And
The force at this time is recorded on a pen recorder 59 as a recorder via a load-voltage converter 58 to measure the attraction force.

The vertical movement of the load cell 57 is as follows.
The rotational driving force of an appropriate driving means 60 such as a motor is transmitted to a lead screw 62 in a state controlled by a desired speed control means 61, and the lead screw 62 is rotated in a desired direction in a rotation direction indicated by a double arrow Z in the drawing. The nut 63 engaged with the lead screw 62 is moved in a desired vertical direction indicated by a double-headed arrow X in FIG.

When the height H of the projecting portion 21 'of the magnetic disk 20' measured by the measuring device having the above configuration is 80 nm, the number N of the projecting portions 21 'and the average upper area A Between the pressure and the suction force, and the height H of the set portion 21 '
12 and 13 showing the relationship between the number N of the protruding portions 21 ', the average upper area A, and the attraction force when is set to 30 nm. It has been found that there is a powerful area. There are two types of large attraction forces, large attraction force (1) and large attraction force (2). One area of the large attraction force (1) has a large attraction force due to a large contact area between the magnetic head and the magnetic disk 20 ′, and the other area of the attraction force (2) has a large attraction force (2). ′ Is elastically deformed, and the magnetic disk 20 ′ has a magnetic head and a projection 21 ′ and a projection 21 ′.
The other parts also come into contact with each other, thereby increasing the contact area and increasing the attraction force. Therefore, the function of the protruding portion 21 'is not exhibited in each of these areas having a large suction force.

Further, comparing the test result of FIG. 12 with the test result of FIG. 13, the value of the height H of the projecting portion 21 ′
It can be seen that the area of the large attraction force (2) is different. Assuming that the height of the projecting portion 21 ′ is H (mm) and the number of projecting portions 21 ′ per 1 mm ² is N, the average area A (mm ² ) of the projecting portion 21 ′ is as follows: 10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N It was found that the adsorbing force was reduced only in the range.

Further, the relationship between the number N of the projecting portions 21 'provided on the magnetic disk having the same configuration as the magnetic disk 20', the average area A of the projecting portions, and the maximum coefficient of friction is examined. A test was conducted to confirm the numerical definition of the formation density of the protruding portions 21 'formed in the CSS area of the magnetic disk 20'. (Test Example 4) First, as a magnetic disk, a glass substrate A 'was subjected to photoetching in the same manner as in Test Example 3 described above, and prismatic protrusions 21'. Are formed in a regular triangular arrangement so that the intervals L are equal to each other, and an underlayer 25 made of Cr and a magnetic layer 26 'made of a Co alloy material and a material made of C are formed on the glass substrate A'. protective layer 27 'of the sequentially arranged, further lubricating layer 28 having a thickness of 1 nm' forming the average over an area 9 .mu.m ^2, height 30nm
The magnetic disk 20 'having the prismatic protrusions 21'... Was manufactured. The number N of the projecting portions 21 'per 1 mm ^{2 of the} magnetic disk 20' was used as a parameter.

As the magnetic head, a mini monolithic type ferrite head was used. Then, the disk is mounted on the HDD using the magnetic disk 20 ′ having the above configuration and the magnetic head, and a drive mounting CSS test is performed.
A test was conducted to investigate the relationship between the number N of protrusions 21 'per 1 mm ^{2 of the} magnetic disk 20' and the maximum friction coefficient. The maximum coefficient of friction is measured by using a load cell as a load, using a sliding resistance (frictional force) when the magnetic disk 20 'is rotated once at a rotation speed of 1 rpm after performing a predetermined number of CSS operations. The maximum load was calculated by dividing the maximum load by the load load of the magnetic head. Then, a case where the maximum friction coefficient exceeded 1 was evaluated as “fail”, and a case where the maximum friction coefficient was 1 or less was evaluated as “pass”. FIG. 14 shows the test results of Test Example 4.

As is clear from FIG. 14 showing the test results, the maximum coefficient of friction is H (H), as in the results of Test Example 3 described above. mm) Assuming that the number of protrusions 21 ′ per 1 mm ² is N, the average upper area A of the protrusions 21 ′ (mm ² )
Was found to be the optimum range only when it is within the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N.

Further, the relationship between the number N of the projecting portions 21 'provided on the magnetic disk having the same configuration as the magnetic disk 20', the average area A of the projecting portions 21 ', and the maximum coefficient of friction was investigated. And a C test of the magnetic disk is performed.
A test was performed to confirm the numerical definition of the formation density of the projecting portions 21 'formed in the SS region. (Test Example 5) First, as a magnetic disk, a glass substrate A 'was subjected to photoetching in the same manner as in Test Examples 3 and 4 to obtain an average surface area of 9 μm ² and a height of 60 nm.
4 are formed in an equilateral triangular arrangement such that the distance L between them becomes equal to 556 / mm ² as shown in FIG. 4, and Cr is formed on the glass substrate A ′. Underlayer 25 'made of material, magnetic layer 2 made of Co alloy material
6 ′, a protective layer 27 ′ made of C and a lubricating layer 28 ′ are sequentially provided, while a data area 22′a having a radius of 25 mm or more is provided.
A magnetic disk 20 'having a configuration in which a prismatic protruding portion 22' having a height of 30 nm and an average surface area of 9 μm ² was formed in the same manner as the protruding portion 21 'provided on the inner peripheral portion was manufactured. The thickness of the lubricating layer 28 'of the magnetic disk 20' was used as a parameter.

As the magnetic head 20 ', a mini monolithic type ferrite head was used. Then, a test was conducted to investigate the relationship between the thickness of the lubricating layer 28 'and the dynamic friction coefficient in the drag test using the magnetic disk 20' having the above-described configuration and the magnetic head. The dynamic friction coefficient was determined by the same method as the maximum friction coefficient of Test Example 4 described above. The result is shown in FIG. The value of the dynamic friction coefficient in FIG. 15 is shown in the range of fluctuation up to 100,000 passes. When the allowable range of the dynamic friction coefficient is set to 1.0 or less, it is found that the appropriate range of the thickness of the lubricating layer 28 'is 0.5 nm or more and 10 nm or less.

As described above, according to Test Example 1 to Test Example 5, according to the magnetic disk 20 of the first embodiment, the CSS characteristics and the adsorbability can be remarkably improved as compared with the conventional magnetic disk, and The design parameters of the projecting portion 21 formed in the inner peripheral portion CSS region 21a can be reliably defined within the optimum range. The design parameters of the protruding portion 21 are extremely practical in forming the protruding portion 21 in the CSS area 21a of the magnetic disk 20, avoiding sticking to the surface of the magnetic disk, and floating the magnetic head. It is possible to form the projecting portion 21 that can guarantee the stability with high accuracy and reliability.

The above Test Examples 3 to 5 are tests for defining the formation density on the magnetic disk 20 of the projecting portion 21 provided in the CSS area 21a on the inner peripheral side of the magnetic disk 20. Although an example is shown, the same test as in Test Examples 4 and 5 was performed on the groove 22 provided in the data area 22a on the outer peripheral side of the magnetic disk 20. Was obtained. That is, the data area 22 in the outer peripheral portion
a in the groove 22 provided in the groove 22a.
m and the height of each protruding portion pattern 22 is H (m
m) Assuming that the number of the projecting portion patterns 22 per 1 mm ² is N, the average upper area A of the groove 22 (mm
² ) is formed within the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N, it is possible to reliably maintain the flying stability of the magnetic head in the data area 22a. Can,
It is possible to guarantee stabilization of magnetic recording characteristics.

The magnetic disk in the magnetic recording apparatus of the first embodiment has a cylindrical projection 21 in the CSS area.
Are formed in the data area 22a, and concentric grooves 22 are formed in the data area 22a. The shape of the protruding portions 21 formed in the CSS area is as shown in FIG. Not only the cylindrical shape but also a protruding shape such as a hexagonal column shape as shown in FIG. 17 and a truncated cone shape as shown in FIG. As long as the forming conditions are satisfied, the same effects as those of the cylindrical projecting portion 21 used in the first embodiment can be obtained. Also in the concentric groove 22 formed in the data area 22a, a spiral groove 222 as shown in FIG. 19 or a stitch-like projecting surface 223 as shown in FIG. To the data area 2
Also in the magnetic disks 20a and 20b formed in 2a, if the groove 222 or the protruding surface 223 satisfies the conditions such as the formation density and the formation height shown in the first embodiment, the above embodiment The same effect as that of the first magnetic disk can be obtained.

Further, the protrusion 21 formed in the CSS area 21a of the magnetic disk 20 of the first embodiment.
.. Can be variously changed to a protruding portion having a cross-sectional shape as shown in FIGS. 21 and 22. A protruding portion 70 having a predetermined height H shown in FIG.
The underlayer 25, the magnetic layer 26, and the protective layer 27 described in describing the configuration of the magnetic disk 20 of the first embodiment are formed on the surface of the above, and a photoresist is coated on the protective layer 27.
Exposure is performed using a photomask having a predetermined shape, development, etching, and the like are performed, and photoetching for removing the photoresist from the substrate is performed, thereby forming a projecting portion 27A having a desired shape. The lubricating layer 28 described above is formed with a predetermined thickness on the surface of the protective layer 27 provided with the portion 27A.

The projecting portion 80 having a predetermined height H shown in FIG.
Using a substrate 24b made of the same material as the protective layer 27,
A photoresist is applied to the substrate 24b, exposed using a photomask having a predetermined shape, developed, etched, and the like, and subjected to photoetching for removing the photoresist from the substrate. After that, the underlayer 25 and the magnetic layer 26 described in the description of the configuration example of the magnetic disk of the first embodiment are formed on the surface of the substrate 24b provided with the protruding portions 24B with a predetermined thickness. Then, the underlayer 25 and the magnetic layer 26 on the surface of the projecting portion 24B are removed by an appropriate means such as a mechanical method or a chemical method, and thereafter, the above-described lubricating layer 28 is formed with a predetermined thickness. is there. In addition, FIG.
1. Of course, the protruding portions 70 and 80 shown in FIG. 22 can be applied not only to the CSS region but also to a groove or a protruding surface formed in the data region with a similar cross-sectional structure. is there.

The magnetic disk 20 according to the first embodiment may have a structure in which the lubricating layer 28 is not formed on the surfaces of the protrusions, grooves, or protrusions formed in the CSS area and the data area of the magnetic disk 20 according to the first embodiment. The same effect as the magnetic disk can be obtained.

As described above, according to the magnetic disk of this embodiment, excellent technical effects can be attained by ensuring that the design parameters of the projecting portions formed on the magnetic disk are within the above-mentioned optimum range. It is possible to reliably form a magnetic disk having the above with high accuracy, and to improve the yield.

Further, the magnetic recording apparatus according to the second embodiment will be described in detail below. (Embodiment 2) The magnetic disk 100 of the embodiment 2 is shown in FIG.
As shown in FIG. 3, the CSS region 110 on the inner peripheral side thereof
a, a large number of dot-shaped protrusions 110 are provided to protrude from the surface axis of the magnetic disk toward the outer periphery. The shape of the protruding portion 110 has a height of 5 nm or more and, as described in the first embodiment, a cross-sectional area orthogonal to the height direction, such as a cylindrical shape as shown in FIG. Is not limited to a fixed one, and depending on the specification,
When the height of the protrusions 110 changes due to wear, the average surface area A of the protrusions 110 in contact with the magnetic head indicates the height of each of the protrusions 110 as H (mm), and the height of each protrusion 110 per mm ^2. Assuming that the number of the parts 110 is N, if it satisfies the formula of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N, a hexagonal column as shown in FIG. Alternatively, various types can be employed as long as they are projecting, such as a truncated cone as shown in FIG.

On the other hand, in the data area 120a of the magnetic disk 100 of the present embodiment, a large number of projecting portions 120 having a predetermined shape are provided so as to protrude from the surface axis of the magnetic disk 100 toward the outer periphery. ing. The shape of the protruding portion 120 has a height of 5 nm or more, more preferably 80 nm or less, and has a constant cross-sectional area perpendicular to the height direction like a V-shaped one as shown in FIG. The average surface area A of the projecting pattern 120 abutting on the magnetic head is not limited to that of the projecting pattern 120. Where H is the height of H (mm) and N is the number of the projecting portion patterns 120 per 1 mm ² , the following equation is obtained: (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N As long as it satisfies, various things such as a rectangular shape as shown in FIG. 26 and an X shape as shown in FIG. 27 can be adopted. The magnetic disk 100 of the second embodiment having the above configuration can be manufactured by the same manufacturing process as the magnetic disk 20 of the first embodiment as described above.

Further, the magnetic disk 10 of the second embodiment
If the shape of the projecting portion patterns 120 formed on 0 is V-shaped as shown in FIG.
The following special effects can be obtained. FIG.
The V-shaped projection 23 shown in FIG.
a, 32a are joined in a V-shape, and a plane triangular space region sandwiched between the air guide portions 32a, 32a is called an air compression portion 32b.

Therefore, the V-shaped projecting portion 32 as described above is used.
When the magnetic disk 100 starts rotating, the projecting portion 32 also moves in the air. Since the air that has entered the air guide portion 32b of the projecting portion 32 is compressed from both sides by the air guide portions 32a, 32a, a positive pressure region having a high air pressure is provided above the projecting portion 32. Occur.

Data area 120a of magnetic disk 100
Are rotated while forming a positive pressure region above each other, so that a large air flow is generated, and the lift generated by the air flow causes the data region 120a of the magnetic disk 100 to be moved. To levitate. Here, the projecting portions 33, 34 having the shape shown in FIGS. 16 to 17 without the air compression portion 32b such as the projecting portion 32,
In the magnetic disk on which the protrusions 32 are formed, the airflow can be generated by the rotation of the magnetic disk 100 on which the protrusions 32 are formed. If so,
At the time of the rotation operation, a strong air flow can be immediately generated by the positive pressure generated by the air compression effect of the projecting portion 32. Therefore, not only the conventional magnetic disk having no projecting portion but also FIG. 18 are formed, the flying stability of the magnetic head can be more reliably maintained than that of the magnetic disk, and the lower flying of the magnetic head can be guaranteed.

Further, a modified example of the projecting portion that can obtain the same effect as the above-described effect of the V-shaped projecting portion pattern 32 of FIG. 24 will be described below. The protruding portion pattern 36 having the shape shown in FIG. 25 is different from the magnetic disk 20 on which the protruding portion pattern 36 of this example is formed below the air compressing portion 36b of the protruding portion pattern 36. Grooves 2 for assisting air compression
This is an example in which 0a is formed. The depth of the groove 20a is formed so as to be deep below the front side 36A in the rotation direction of the magnetic disk 20 and shallow below the rear side 36B in the rotation direction of the magnetic disk 20 in the protrusion pattern 36. Have been.

By adopting the configuration shown in FIG. 25, the volume of the air compression section 36b is increased, and the air guide sections 36a, 3
Since the amount of air compressed by 6a can be increased, a higher positive pressure can be generated than in the configuration shown in FIG. 7, and the magnetic head can fly faster.

The configuration example of the shape shown in FIG. 26 is a modified example of the projecting portion patterns 32 and 36 shown in FIGS. 24 and 25, and the projecting portion pattern 37 is an air guide portion 37a.
The area 37a is formed in a U-shape formed by connecting the walls 37A with a wall 37A, and a region surrounded by the air guides 37a, 37a and the wall 37A is an air compressor 37b. The projecting portion 32 described above is also provided by the projecting portion pattern 37 having this configuration.
The same effect as described above can be obtained.

The protruding portion pattern 38 having the shape shown in FIG.
Is formed by connecting the air guides 38a, 38a in an X-shape, and the end of the air guide 38a and another air guide 38a
An air compression portion 38b is formed between the end portion and the end portion. With the projecting portion pattern 38 having this configuration, the same effect as that of the projecting portion patterns 32 and 37 described above can be obtained.

The projecting portion pattern 39 having the shape shown in FIG.
A short air guide 39 is provided at both ends of the horizontally long wall 39A.
a and 39a are extended at right angles. With the projecting portion pattern 39 having this configuration, the same effects as those of the projecting portion patterns 32, 37, and 38 described above can be obtained.

As described above, the shape of the projecting portion pattern 120 formed in the data area 22a maintains the flying stability of the magnetic head flying and running on the data area 120a, and stabilizes the magnetic recording characteristics. The height is 5 nm or more, more preferably 80 nm
The average surface area A of the projecting portion pattern 120 that is in contact with the magnetic head is H (mm), the height of the projecting portion pattern 120 is H (mm), and the number of projecting portions 120 per 1 mm ² is N. In some cases, if the expression (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N is satisfied, and the flying stability of the magnetic head can be maintained and the magnetic characteristics can be guaranteed, Needless to say, the shape is not limited to the shape shown above.

The protrusions 110 formed in the CSS area 110a of the magnetic disk 100 of the second embodiment are similar to those of the first embodiment shown in FIGS.
Various modifications can be made to the projecting portion having the cross-sectional shape as shown in FIG. 2, and such a cross-sectional shape as shown in FIGS. 21 and 22 is applied to the projecting portion pattern 120 formed in the data area 120a. Of course you can do that.
Further, even in the case where the lubricating film 28 is not formed on the protruding portions 110 and the protruding portion patterns 120, the second embodiment can be used.
The same effect as that of the magnetic disk 100 can be obtained.

Next, the relationship between the arrangement state and the size of the protrusion patterns 120... Formed in the outer peripheral data area 120 a of the magnetic disk 100 will be described. When the protrusion patterns 120... Having the above-described shapes are provided in the data area 120 a of the magnetic disk 100, the protrusion patterns 120 are formed concentrically on the inner peripheral side. In addition, along the rotation direction of the magnetic disk 100 as shown in FIG.
A configuration in which the size of the protrusions 4 is sequentially reduced from the outer peripheral side to the inner peripheral side is an example of the arrangement configuration of the projecting portion patterns 120.

FIG. 30 shows another example of the arrangement of the projection patterns 40 to 44. In this example, the projecting portion patterns 40, 41,
42 and 43 are sequentially arranged.
0 to 44 are arranged in a staggered manner in the circumferential direction of the magnetic disk 20. As described above, there are various arrangement methods for the arrangement of the projecting portion patterns 40 to 44, and any arrangement method may be applied.

In the magnetic recording apparatus according to the second embodiment having the above-described configuration, the CSS area and the data area of the magnetic disk and the boundary between the CSS area and the data area are also provided, as in the first embodiment. In addition to maintaining the flying stability of the magnetic head, the magnetic film that composes the magnetic disk is not limited to a magnetic film that does not require magnetic anisotropy, and a magnetic film that requires magnetic anisotropy can be used. The coercive force required for the recording device can be obtained.

[0088]

According to the magnetic disk according to the first aspect of the present invention, by providing a plurality of protruding portions in the CSS area on the inner peripheral side, during rotation of the magnetic disk,
A positive pressure region is generated between the projecting portions, and an airflow resulting from the positive pressure region is generated. Then, this air current acts on the magnetic head, and causes the magnetic head to fly quickly.
An airflow is generated by rotation even in a normal magnetic disk having no protrusion, but in a magnetic disk having a protrusion, a positive pressure generated due to an air compression effect between the protrusions at the start of rotation. As a result, a strong airflow can be immediately generated, and the magnetic head flies faster than before.
Therefore, the time when the magnetic head contacts and rubs the magnetic disk at the start of rotation of the magnetic disk is shortened, and the possibility of damage to the magnetic disk is reduced. further,
The height of the protrusion is set within a range of 5 to 80 nm.
Therefore, the coefficient of friction with the magnetic head is suppressed to an appropriate range.
At the same time as the magnetic head flies
Since the levitation traveling can be performed without occurrence of entanglement, the levitation stability of the magnetic head can be more reliably ensured.

Further, when the magnetic head is in contact with the CSS area of the magnetic disk when the magnetic disk is stopped, the magnetic head moves to the height formed on the CSS area.
It comes into contact with the magnetic disk through a plurality of protrusions of 5 to 80 nm . Then, since the conventional mirror-to-mirror contact is eliminated, the phenomenon that the magnetic head is attracted to the magnetic disk does not occur. Therefore, the failure of the magnetic recording device which has conventionally occurred due to the magnetic head adsorption phenomenon does not occur.

Further, by providing concentric or spiral grooves in the data area, it is possible to reduce the difference in height from the protruding portions formed in the CSS area. In this way, it is possible to reduce the difference in the boundary between the CSS area and the data area, which has been regarded as a problem of the magnetic disk having the texture formed thereon, and to fly the magnetic head at the boundary between the CSS area and the data area. It is possible to ensure the stability. Therefore, stable magnetic recording characteristics can be guaranteed. The height of the projecting portion provided in the CSS area and the projecting portion pattern provided in the data area are as follows:
Arbitrary design adjustments are possible.

In the case where a texture is used in the data area as in the prior art, it is difficult to adjust the surface roughness of the texture, and there is a problem that a head crash or the like occurs during the floating operation of the magnetic head. However, in the magnetic recording apparatus according to the present invention, since a concentric or spiral groove is formed in the data area of the magnetic disk, problems such as head crash can be avoided. Further, the magnetic film of the magnetic disk is not limited to a magnetic film that does not require magnetic anisotropy, and a magnetic film that requires magnetic anisotropy can be used, and the coercive force required for a magnetic recording device can be reduced. It is possible to get.

Further, the magnetic disk substrate
0.5 nm or more and 10 nm or less on the side in contact with the pad
It is repeated many times because of the lubrication layer of
Levitating running and sliding operation of the magnetic head with respect to the magnetic disk
Kinematic friction coefficient also increases by CSS operation including
Without causing adsorption or damage,
We can provide more secure magnetic disks
You.

Further, in the present invention, the density of the protruding portion is set to 1
By setting the range of 11 to 1110 pieces / mm ² ,
The value of the large friction coefficient can be suppressed, and the effect of the lubricating layer
Less likely to cause adsorption or damage in conjunction with the fruit
We can provide more secure magnetic disks
You.

Under the above conditions, the above C
When the height of each projecting portion in the SS region and each projecting portion pattern in the data region is H (mm), and the number of the projecting portions per 1 mm ² is N, the average area A of each projecting portion is shown. (Mm ² )
^Is formed within the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N, whereby the magnetic head of the magnetic head is
It is possible to suppress the suction force to the disk to a small range.
Can, for the medium facing surface of the magnetic head, it is possible to maintain the CSS characteristics of the very good magnetic heads, it is possible to allow stable magnetic recording characteristics.

[0095]

[0096]

[0097]

Therefore, according to the magnetic disk of the present invention,
In the CSS area on the inner peripheral side, the suction and sliding resistance (frictional force) with the magnetic head can be reduced,
The durability is improved by the CSS, and in the data area on the outer peripheral side, the floating stability of the magnetic head flying and flying over this data area can be improved, and the magnetic head can be further lowered. . Further, since the height can be adjusted in the boundary region between the CSS region and the data region, the difference in the boundary region can be reduced, and the flying stability of the magnetic head traveling on the boundary region can be improved. In addition, stabilization of magnetic recording characteristics can be guaranteed.

[Brief description of the drawings]

FIG. 1A is a schematic diagram showing a magnetic disk according to a first embodiment of the present invention. FIG.
It is a sectional side view of (a). FIG. 1C is an enlarged view of a main part of FIG. 1B.

FIG. 2 is a diagram for explaining a method of manufacturing the magnetic disk according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a forming process of forming a protruding portion provided on the magnetic disk according to the first embodiment of the present invention by a photolithography technique;

FIG. 4 is a diagram for explaining an arrangement state of protruding portions provided in the CSS area of the magnetic disk in Test Examples 1 to 6 of the first embodiment.

FIG. 5 is a diagram for explaining a cross-sectional shape of a protruding portion provided in a CSS region of a magnetic disk in Test Examples 1 to 6 of Example 1.

FIG. 6 is a diagram illustrating test results in Test Example 1 of Example 1.

FIG. 7 is a diagram illustrating test results in Test Example 2 of Example 1.

FIG. 8A is a diagram showing an ideal shape of a protruding portion provided on a magnetic disk according to the present invention. FIG.
FIG. 9B is a diagram showing a bearing curve in the magnetic disk provided with the protruding portion shown in FIG. FIG.
FIG. 9C is a diagram showing an amplitude distribution in the magnetic disk provided with the protruding portions shown in FIG.

FIG. 9A is a diagram illustrating an example of a configuration of a protruding portion provided on a magnetic disk according to the present invention. FIG.
FIG. 10B is a diagram showing a bearing carp in the magnetic disk provided with the protruding portion shown in FIG. FIG.
FIG. 10C is a diagram showing an amplitude distribution in the magnetic disk provided with the protruding portions shown in FIG.

FIG. 10 (a) is a diagram showing the shape of a texture conventionally provided and used on the surface of a magnetic disk. FIG. 10B is a diagram showing a bearing curve in a magnetic disk provided with a texture as shown in FIG. FIG. 10C is a diagram showing an amplitude distribution in a magnetic output provided with a texture as shown in FIG. 10A.

FIG. 11 is a schematic diagram illustrating an apparatus for measuring the attraction force of a magnetic head on a magnetic disk in Test Example 3 of the magnetic disk of Example 1.

FIG. 12 is a diagram showing test results of Test Example 3 in Example 1.

FIG. 13 is a diagram illustrating test results of Test Example 3 in Example 1.

FIG. 14 is a diagram showing test results of Test Example 4 in Example 1.

FIG. 15 is a diagram showing test results of Test Example 5 in Example 1.

FIG. 16 is a diagram illustrating a configuration example of a protruding portion provided on the magnetic disks according to the first and second embodiments.

FIG. 17 is a diagram illustrating a configuration example of a protruding portion provided on the magnetic disks according to the first and second embodiments;

FIG. 18 is a diagram illustrating a configuration example of a protruding portion provided on the magnetic disks according to the first and second embodiments.

FIG. 19 is a diagram illustrating an example of a spiral groove provided in a data area according to the first embodiment.

FIG. 20 is a diagram illustrating a configuration of a stitch-shaped protruding surface provided in a data area according to the first embodiment.

FIG. 21 is a diagram illustrating a side cross section of a configuration example of the protruding portions of the magnetic disks according to the first and second embodiments.

FIG. 22 is a diagram illustrating a side cross section of a configuration example of a protruding portion of the magnetic disk according to the first and second embodiments.

FIG. 23A is a schematic configuration diagram of a magnetic disk according to a second embodiment. FIG. 23B is a cross-sectional view of FIG. FIG. 23 (c) is an enlarged view of a main part of FIG. 23 (b).

FIG. 24 is a diagram illustrating an example of a configuration of a protruding portion pattern provided in a data area of the magnetic disk of the second embodiment.

FIG. 25 is a diagram illustrating a configuration example of a protruding portion pattern provided in a data area of a magnetic disk according to a second embodiment;

FIG. 26 is a diagram illustrating a configuration example of a protruding portion pattern provided in a data area of a magnetic disk according to a second embodiment;

FIG. 27 is a diagram illustrating an example of a configuration of a protruding portion pattern provided in a data area of a magnetic disk according to a second embodiment;

FIG. 28 is a diagram illustrating a configuration example of a protruding portion pattern provided in a data area of a magnetic disk according to a second embodiment;

FIG. 29 is a diagram illustrating an example of an array of protrusions on the magnetic disk according to the second embodiment;

FIG. 30 is a diagram illustrating an example of an array of protruding portions patterns on the magnetic disk according to the second embodiment;

FIG. 31 (a) is a schematic configuration diagram showing a magnetic disk having a configuration in which a plurality of protrusions are provided in a CSS area and a texture is formed in a data area. FIG.
1 (b) is a side sectional view of FIG. 31 (a). FIG.
FIG. 31 (c) is an enlarged view of a main part of FIG. 31 (b).

FIG. 32A is a schematic diagram showing a side cross section of a magnetic disk substrate in a conventional magnetic disk. FIG.
FIG. 2B is a diagram showing a cross-sectional structure of a laminated film laminated on the surface of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Magnetic disk 20 'Magnetic disk 21 Projecting part 21' Projecting part 21'a Inner peripheral part (CSS area) 21a Inner peripheral part (CSS area) 22 Projecting part 22 'Projecting part 22a Outer peripheral part ( 22'a Outer peripheral side (data area) 70 Projected section 80 Projected section 100 Magnetic disk 110 Projected section 110a Inner peripheral section (CSS area) 120 Groove 120a Outer peripheral section (data area) 220 Protruded section Surface (groove) 220 'bottom surface H height of protrusion A magnetic disk substrate A' magnetic disk substrate B magnetic disk substrate C magnetic disk substrate

Claims (2)

(57) [Claims] A magnetic head reads and writes information, is driven to rotate, and forms a protective layer on a substrate with a magnetic layer.
In a magnetic disk coated with a layer and a lubricating layer , at least one of the front and back surfaces of the magnetic disk substrate
And the inner circumference corresponding to the CSS area where the magnetic head flies
A large number of protruding protrusions are formed in the part, and data recording and reproduction
Same heart circle on the outer peripheral portion corresponding to the data area to be shaped or spiral groove is formed, the inner peripheral portion corresponding to CSS region in the magnetic disk
The height of the protruding portion provided on the side is 5 nm or more and 80 nm or less.
It is a lower, the projecting portion height H (mm), 1mm ² per
When the number of the projecting portions is N, the flatness of each projecting portion is
The leveling area A (mm ² ) is in the range of (10 ⁻⁵ / N · H) ² ≦ A ≦ 15 × 10 ⁻² / N , and the thickness of the lubricating layer is 0.5 nm or more,
A magnetic disk having a thickness of 10 nm or less . 2. The density of the protruding portions is 111 to 1110.
According to claim 1, characterized in that it is in the range of / mm ²
Magnetic disk.