JP3349143B2 - Method of manufacturing master disk and magnetic disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a master disk for magnetically transferring magnetic information to a slave disk using a magnetic disk as a slave disk.

[0002]

2. Description of the Related Art At present, a magnetic recording / reproducing apparatus has a tendency to have a high recording density in order to realize a small and large-capacity magnetic recording / reproducing apparatus. In the field of hard disk drives, which are typical magnetic recording / reproducing devices, the areal recording density is already 3 Gb.
A device exceeding it / in2 (4.65 Mbits / mm2) has been commercialized, and after several years, the areal recording density is 10 Gbits / in2 (15.5 Mbits / mm2).
The rapid technological progress is expected as the practical application of the device 2) is expected.

[0003] The technical background that has enabled such a high recording density is to improve the performance of magnetic recording media and head-disk interfaces, and to improve the linear recording density by the emergence of new signal processing methods such as partial response. Is mentioned.

Here, the partial response is a method of intentionally giving known inter-symbol interference at the time of waveform equalization performed to avoid inter-symbol interference when the linear recording density is increased. In addition, it is characterized in that the deterioration of S / N can be prevented as compared with the conventional peak detection and integral detection.

However, in addition to the emergence of such a signal processing method, in recent years, the trend of increasing the track density has greatly exceeded the trend of increasing the linear recording density, which is a major factor in improving the areal recording density. This is due to the practical use of a magnetoresistive element type head which has much better reproduction output performance than a conventional induction type magnetic head. At present, the practical use of a magnetoresistive element type head makes it possible to reproduce a track width signal of several μm or less with a high S / N ratio.
On the other hand, it is expected that the track pitch will reach the submicron region in the near future with further improvement in head performance in the future.

In order for the magnetic head to accurately scan such a narrow track and reproduce a signal with a high S / N ratio, the tracking servo technique of the magnetic head plays an important role. Regarding such tracking servo technology, for example, see “Yamaguchi: High Accuracy Servo Technology for Magnetic Disk Drives, Journal of the Japan Society of Applied Magnetics, Vol. 20, No. 3, p. 771,
(1996)]. According to this document, in a current hard disk drive, an area in which a tracking servo signal, an address information signal, a reproduction clock signal, and the like are recorded at regular angular intervals in one round of the disk, that is, in 360 degrees. Hereinafter, referred to as a “preformat recording area”).
As a result, the magnetic head reproduces these signals at regular intervals, confirms its position, and can accurately scan the track while correcting the radial displacement of the magnetic disk as necessary. .

The preformat information signals such as the tracking servo signal, the address information signal, and the reproduction clock signal serve as reference signals for the magnetic head to accurately scan the track. Accurate track positioning accuracy is required. For example, "Uematsu, et al .: Current Status and Prospects of Mechanical Servo, HDI Technology, 93rd Meeting of the Japan Society of Applied Magnetics, 93-5, pp.3
5 (1996)], in a current hard disk drive, after a magnetic disk and a magnetic head are incorporated in the drive, a unique servo track recording device is used to assemble the magnetic disk and the magnetic head. Recording of a tracking servo signal, an address information signal, a reproduction clock signal, and the like is performed by the magnetic head.
In this case, the necessary track positioning accuracy is realized by performing preformat recording while precisely controlling the position of the unique magnetic head incorporated in the drive by an external actuator provided in the servo track recording device. .

However, the prior art in which a dedicated servo track recording device is used to perform preformat recording by a unique magnetic head built in a drive has the following problems.

First, since recording by a magnetic head is basically linear recording by relative movement between a magnetic head and a magnetic recording medium, a dedicated servo track recording device is used to precisely position the magnetic head. In the above-described method in which recording is performed while controlling, much time is required for preformat recording. Further, since the dedicated servo track recording device is considerably expensive, the cost required for preformat recording increases.

[0010] This problem becomes more serious as the track density of the magnetic recording / reproducing apparatus increases. In addition to the increase in the number of tracks in the radial direction of the disk, the time required for preformat recording also increases for the following reasons. That is, the higher the track density, the higher the accuracy of the positioning of the magnetic head is required. Therefore, it is necessary to reduce the angular interval for providing a preformat recording area for recording information signals such as a servo signal for tracking in one round of the disk. No. Therefore, the higher the recording density of the device, the larger the amount of signals to be preformat-recorded on the disk, and more time is required.

Although magnetic disk media tend to be smaller in diameter, there is still much demand for large-diameter disks of 3.5 inches or 5 inches. The larger the recording area of the disc, the larger the signal amount to be preformat-recorded. The time required for preformat recording also greatly affects the cost performance of such a large-diameter disk.

Second, since the recording magnetic field expands due to the spacing between the magnetic head and the magnetic recording medium and the shape of the tip pole of the magnetic head, the magnetization transition at the end of the track on which preformat recording has been performed is reduced. Lack of steepness.

Since the recording by the magnetic head is basically a dynamic linear recording by the relative movement between the magnetic head and the magnetic recording medium, from the viewpoint of the interface performance between the magnetic head and the magnetic recording medium, A certain amount of spacing must be provided between the magnetic head and the magnetic recording medium.
In addition, since the current magnetic head generally has a structure having two elements that separately perform recording and reproduction, the width of the trailing edge side pole of the recording gap corresponds to the recording track width,
The width of the leading edge side pole is as large as several times or more of the recording track width.

Both of the above two problems are factors that cause the recording magnetic field to spread at the end of the recording track. As a result, there arises a problem that the magnetization transition at the end of the recording track on which the preformat recording is performed lacks sharpness, or an erased area is formed on both sides of the track end. In the current tracking servo technology, the position of the magnetic head is detected based on the amount of change in the reproduction output when the magnetic head scans off the track. Therefore, not only is the magnetic head excellent in the S / N ratio when the magnetic head scans the track accurately as in the case of reproducing the data signal recorded between the servo areas, but also the magnetic head moves off the track. It is required that the reproduction output change amount during scanning, that is, the off-track characteristic is steep. Therefore, if the magnetization transition at the end of the track on which preformat recording is performed lacks sharpness as described above, it will be difficult to realize an accurate tracking servo technique in future submicron track recording.

In order to solve the two problems in the preformat recording by the magnetic head as described above, the surface of the master information carrier having a ferromagnetic thin film pattern corresponding to the preformat information signal formed on the surface of the substrate. A magnetic pattern corresponding to the ferromagnetic thin film pattern is recorded on the magnetic recording medium by magnetizing the ferromagnetic thin film pattern formed on the master information carrier after contacting the ferromagnetic thin film pattern with the surface of the magnetic recording medium. 10-4
No. 0544.

According to this preformat recording technique,
Good preformat recording can be efficiently performed without sacrificing other important performances such as the S / N ratio of the recording medium and interface performance.

According to the contents disclosed in the publication, a ferromagnetic thin film pattern corresponding to a preformat information signal such as a servo signal for tracking, an address information signal, and a reproduction clock signal is formed by a master using a conventional photolithography technique. It can be formed on the surface of the information carrier.

FIG. 3 shows one of the arrangements of the ferromagnetic thin film patterns.
Here is an example. The hatched portion (2) in the figure is an array of ferromagnetic thin films.

FIG. 4 is a partial sectional view of a magnetic transfer master disk for transferring a servo signal to a magnetic disk by a method described in the publication. 1 is a master disk base, and 2 is a ferromagnetic thin film. The ferromagnetic thin film 2 is partially embedded in the master disk substrate 1. For the ferromagnetic thin film 2, a soft magnetic material having a high saturation magnetic flux density such as cobalt or permalloy is used.

FIG. 5 illustrates the overall configuration of a conventional master disk having the above-described arrangement pattern of ferromagnetic thin films. Reference numeral 3 denotes a master disk, 5 is a land portion which comes into close contact with the surface of the magnetic disk when the magnetic disk is brought into close contact, 4 is an array pattern portion of a ferromagnetic thin film provided on the land portion 5, and 6 is a specific step from the land portion 5. This is a concave portion having

FIG. 6 is a plan view of the conventional master disk 3. The broken lines drawn concentrically are the outer diameter and the inner diameter of the magnetic disk 7 which is in close contact with the master disk 3 and on which information is transferred. Is shown. The recess 6 radially expands as a plurality of grooves from the center of the master disk 7 and is closed inside the outer diameter of the magnetic disk 7. On the other hand, the lands 5 radially spread from the center of the master disk 3 toward the outer periphery, and are connected inside the outer diameter of the magnetic disk 7.

As described above, when the magnetic disk 7 is brought into close contact with the master disk 3 at the time of transfer, the concave portion 6 closes at the outer peripheral end of the magnetic disk 7 and is released at the inner peripheral end of the magnetic disk. It forms a space.

FIG. 7 to FIG.
FIG. 4 is a diagram for explaining a process of magnetically transferring the data to the magnetic disk 7 using FIG. In these figures, reference numeral 8 denotes a magnetic disk 7
And 9 is a magnet for generating a transfer magnetic field.

In the first stage of the magnetic transfer, as shown in FIG. 7, the magnet 9 is brought close to the magnetic disk 7, and the magnetic disk 7 is rotated and scanned in the circumferential direction. By doing so, the first magnetization 10 in one direction remains in the circumferential direction on the entire surface of the magnetic disk 7, as shown by the arrow in FIG.

In the second stage of the magnetic transfer, the master disk 3 is superimposed on the magnetic disk 7 which is magnetized in one direction as shown in FIG. Next, the air between the master disk 3 and the magnetic disk 7 is exhausted from the air vent of the spindle 8. At this time, the air in the space formed by the concave portion 6 of the master disk 3 and the magnetic disk 7 is discharged, and the concave portion 6 becomes negative pressure. By doing so, the master disk and the magnetic disk come into close contact.

Next, as in the first stage, the magnet 9 is brought close to the magnetic disk 7 and rotationally scanned in the circumferential direction of the magnetic disk 7. At this time, the rotational scanning direction may be the same direction as the first stage or the reverse direction.
Is opposite to the polarity in the first stage. By doing so, as shown in FIG.
In the portion of the ferromagnetic thin film opposing the arrangement pattern portion 4,
A magnetized pattern magnetization region 11 corresponding to the arrangement is formed, and a portion of the ferromagnetic thin film of the master disk 3 other than the portion opposed to the arrangement pattern portion 4 is circumferentially unidirectional as indicated by an arrow. The second magnetization 12 remains.

The quality of a signal recorded on the magnetic disk 1 by such magnetic transfer is determined by the distance between the ferromagnetic thin film and the surface of the magnetic disk when a transfer magnetic field is applied. That is, it is determined by how well the master disk and the magnetic disk adhere.

[0028]

Here, in a hard disk drive, since the gap between the magnetic head and the magnetic disk is several tens of nanometers, there is a problem even if fine foreign matter is present on the magnetic disk. Therefore, in the process of manufacturing a magnetic disk, inspection of foreign matter on the magnetic disk is performed.

The inspection is generally performed by a method as shown in FIG. In FIG. 11, 13 is a laser beam irradiated on the surface of the magnetic disk 7, 14 is a regular reflection component of the laser beam 13 reflected by the magnetic disk 7, and 15 is a reflected scattered light scattered by a foreign matter on the magnetic disk 7. is there. Usually, the presence or absence of a foreign substance on the magnetic disk 7 is determined by detecting the reflected scattered light 15 scattered by the foreign substance with the detector 16.

However, as shown in FIG.
The laser light 13 is liable to be irregularly reflected at the inner and outer peripheral edges of the detector 1.
6 and is erroneously determined as a foreign matter. Therefore, as shown in FIG. 13, the foreign matter inspection range 17 is usually outside a predetermined distance (generally 0.1 mm to 0.5 mm) from the inner peripheral edge and a predetermined distance (generally 0.1 mm) from the outer peripheral edge. Actually, it is set to an area inside 0.5 mm or more from the center.

On the other hand, in the manufacturing process of the magnetic disk, since the outer and inner peripheral edges of the magnetic disk 1 are gripped for transportation, there is a high probability that foreign matter is attached. in spite of,
As described above, since the outer and inner peripheral ends are not included in the foreign substance inspection range, even if there is a foreign substance, no foreign substance 18 is detected on the outer and inner peripheral ends as shown in FIG. The probability that the manufactured magnetic disk 7 passes the inspection and is manufactured is very high.

FIG. 14 shows a problem in the case where transfer is performed to the magnetic disk 7 to which such foreign matter has adhered. FIG.
As shown in FIG. 4, the surface of the master disk 3 and the surface of the magnetic disk 7 cannot be brought into close contact with each other at the portion of the magnetic disk 7 to which the foreign matter 18 adheres, and are separated. In such a portion, the magnetic field on the surface of the magnetic disk 7 is disturbed,
Information from the ferromagnetic thin film array of the master disk 3 is not magnetically transferred to the magnetic disk 7 correctly.

That is, since the outer peripheral end and the inner peripheral end of the magnetic disk are not included in the foreign substance inspection range, even if foreign substances exist in these areas, the foreign substance inspection is passed, and the outer peripheral end and the inner peripheral end are removed. Transfer defects frequently occurred.

Also, in the process of manufacturing the master disk, the outer edge of the master disk is often gripped in order to transport the master disk, and there is a high probability that foreign matter will adhere to the outer edge of the master disk.

As shown in FIG. 6, in the conventional master disk, the area larger than the outer diameter of the magnetic disk 7 is
It is. Therefore, foreign matter attached to the end of the master disk 7 due to the handling of the master disk 7
It is easy to move to the land portion 5 which is a contact area with the magnetic disk 7. In particular, such a phenomenon occurs in a mucous foreign matter. Foreign matter that has migrated to the contact area hinders the contact between the master disk and the magnetic disk, causing a transfer signal defect.

Accordingly, the present invention is to provide a master disk which does not cause such transfer signal failure.

[0037]

In order to solve the above-mentioned problems, a master disk according to the present invention has a structure in which an array of ferromagnetic thin films is formed and a land portion which is in close contact with the surface of a magnetic disk.
A concave portion that does not adhere to the surface of the magnetic disk is provided, and the region where the land portion exists is limited to a region inside a predetermined distance from the outer peripheral end of the opposing magnetic disk or a region outside a predetermined distance from the inner peripheral end.

Further, the master disk of the present invention has a larger diameter than the magnetic disk facing the master disk.

[0039]

The invention described in DETAILED DESCRIPTION OF THE INVENTION 請 Motomeko 1 was formed into an array pattern corresponding to a Jo Tokoro information signal magnetic
Has a membrane, at <br/> master disk for transfer recording arrangement pattern corresponding to the information signal by applying an external magnetic field to the magnetic film is in close contact with the surface of the magnetic disk to the magnetic disk surface And the outer diameter of the magnetic disk
A base having a larger outer diameter, and the magnetic disk on the base.
Installed inside a circular area smaller than the disk outer diameter by a specified dimension
It is the radial land portion to which the arrangement of the magnetic film is formed in close contact with the magnetic disk, formed between the land portion
And the step with respect to the land is several micrometers
And radial recesses not in close contact with the magnetic disk is al few tens of micrometers, is formed in the disk center the
The magnetic disk has a radial concave portion and a continuous central concave portion, and a radial space formed when the magnetic disk is brought into close contact with the magnetic disk and surrounded by the concave portion is directed outward at an outer peripheral end of the magnetic disk. Characterized by being open to the public
You. With this configuration, it is possible to prevent the foreign matter on the outer peripheral end of the magnetic disk from hindering the close contact between the master disk and the magnetic disk.

[0040] In addition, the invention described in 請 Motomeko 2, the predetermined information
Magnetic film formed in an array pattern shape corresponding to the information signal
Using a master disk with
By applying an external magnetic field by bringing the magnetic film into close contact,
An array pattern corresponding to the information signal is displayed on the magnetic disk table.
A method for manufacturing a magnetic disk for recording and transferring data on a surface, comprising:
The star disk is larger than the outer diameter of the magnetic disk
A base having an outer diameter; and a magnetic disk on the base.
Installed inside a circular area smaller than the outer diameter by a predetermined dimension,
An array of magnetic films is formed and adheres to the magnetic disk
A radial land portion, formed between the land portion;
The level difference from the land is several micrometers to several tens of meters.
A non-adhesive magnetic disk
A radial recess, and the radial
It has a concave portion and a continuous central concave portion.
The magnetic disk and the recess formed when the magnetic disks are brought into close contact with each other.
The radial space surrounded by
The master disk is opened outwardly at the part
Close to the magnetic disk and exhaust air from the central recess.
By doing so, the magnetic disk and the master
-Generates airflow in a radial space surrounded by disc recesses
It is characterized in that transfer recording is performed in a state where the recording is performed.

Further, the invention according to claim 3 of the present invention provides:
2. The master disk according to claim 1, wherein the outer diameter of the master disk is larger than that of the magnetic disk, whereby foreign matter adhering to the outer periphery of the master disk adheres to the outer periphery of the master disk. It is possible to prevent the adhesion of the master disk and the magnetic disk from being hindered by the foreign matter.

Embodiment 1 Hereinafter, a master disk according to the present invention will be described.

FIG. 1 is a plan view of a master disk 3 according to the embodiment of the present invention. In FIG. 1, concentric large and small broken lines indicate the outer diameter and the inner diameter of the magnetic disk 7.

As shown in FIG. 1, a land portion 5 is provided on the surface of the master disk 3 so as to be in close contact with the magnetic disk 7.
Is formed, the land portion 5 has a diameter DLi whose inner diameter is larger than the inner diameter Di of the magnetic disk 7 and a diameter DLo whose outer diameter is smaller than the outer diameter Do of the magnetic disk 7.
It has become. It is desirable that these dimensional relationships be in the following ranges. DLi-Di = 0.1 to 1.0 (mm) Do-DLo = 0.1 to 1.0 (mm) That is, if the dimensional difference between DLi and Di and the dimensional difference between Do and DLo are 0.1 mm or more, Even when the magnetic disk 7 and the master disk 3 are in close contact with each other, no foreign matter adheres to the master disk, and since the dimensional difference is 1 mm or less, the signal recording area of the magnetic disk can be effectively used without narrowing. Becomes

The land 5 has a radial shape as shown in the figure, and the area other than the land 5 on the master disk 3 has a step of several micrometers to tens of micrometers with respect to the land 5. Recess 6.

The outer diameter Dm of the master disk base 1 is
Is larger than the outer diameter Do of the magnetic disk 7.

FIG. 2 is a diagram for explaining the effect of the master disk in the embodiment of the present invention. In FIG. 2, air in a space formed by the concave portion 6 of the master disk 3 and the magnetic disk 7 is exhausted by a vacuum pump 19 through a vent of the spindle 8.
The master disk 3 and the magnetic disk 7 are pressed against each other by the atmospheric pressure due to the negative pressure in those spaces, and the land 5 of the master disk 3 is
Adhere to

FIG. 4 shows a cross section of the master disk 3. As described above, the ferromagnetic thin film 2 is disposed on the land 5 provided on the master disk base 1.

That is, the master disk 3 has a plurality of fine arrays corresponding to information signals on the surface of the land portion 5 of the disk-shaped master disk base 1 made of a nonmagnetic material such as a Si substrate, a glass substrate, or a plastic substrate. The recess is formed in a pattern shape, and the ferromagnetic thin film 2 is embedded in the recess.

As the ferromagnetic thin film 2, many kinds of magnetic materials can be used regardless of the amount of hard magnetic material, semi-hard magnetic material, and soft magnetic material, and digital information signals can be transferred and recorded on a magnetic recording medium. Anything is fine. For example,
Fe, Co, an Fe—Co alloy, or the like can be used. In order to generate a sufficient recording magnetic field irrespective of the type of the magnetic recording medium on which the master information is recorded, the larger the saturation magnetic flux density of the magnetic material, the better. In particular, 2000
For a magnetic disk having a high coercive force exceeding Oersted or a flexible disk having a large magnetic layer thickness, sufficient recording may not be performed if the saturation magnetic flux density is 0.8 Tesla or less. , 0.8 Tesla or more, preferably a magnetic material having a saturation magnetic flux density of 0.1 Tesla or more.

The thickness of the ferromagnetic thin film 2 depends on the pit length, the saturation magnetization of the magnetic recording medium and the thickness of the magnetic layer. For example, the pit length is about 1 μm, and the saturation magnetization of the magnetic recording medium is about 500 em.
In the case where u / cc and the thickness of the magnetic layer of the magnetic recording medium are about 20 nm, the thickness may be about 50 nm to 500 nm.

Here, if the master disk 3 according to the present invention shown in FIG. 1 is used, as shown in FIG. 2, foreign matters 18 attached to the inner peripheral end and the outer peripheral end of the magnetic disk 7 are removed from the master disk 3. The recesses 6 correspond to these portions on the side 3, and even if the foreign matter 18 exists, the recesses 6 enter the step between the land portions 5 and the recesses 6. Therefore, the ferromagnetic thin film formed on the land portions 5. Array pattern part 4
There is no hindrance to the close contact between the disk and the magnetic disk 7. Therefore, no transfer signal failure occurs.

In the case where foreign matter attached to the outer peripheral portion of the master disk 3 is attached to an area on the master disk 3 outside the outer diameter Do of the magnetic disk 7, such foreign matter is attached to the master disk 3 and the magnetic disk 7. Does not hinder the close contact of the magnetic disk 7, and even if it adheres to the area on the master disk 3 inside the outer diameter Do of the magnetic disk 7, the land 5 does not exist on the outer periphery of the master disk 3 and the recess 6 Since only the foreign matter enters the step between the land portion 5 and the concave portion 6, the close contact between the master disk 3 and the magnetic disk 7 is not hindered. Therefore, no transfer signal failure occurs.

Further, even if foreign matter adheres to the outer peripheral portion in the process of handling the master disk 3, the foreign matter adheres to the concave portion 6. Low. That is, the close contact between the master disk 3 and the magnetic disk 7 is not hindered, and no transfer signal failure occurs.

As a method of forming the recess 6 in the master disk substrate 1 as shown in FIG. 1, when the material of the master disk substrate 1 is a silicon wafer, a physicochemical method such as a reactive ion etching or an ion milling process is used. However, it is needless to say that similar results can be obtained by other methods, for example, mechanical methods such as sandblasting.

[0056]

As described above, by using the master disk of the present invention, specific information is provided by the shape pattern of the ferromagnetic thin film array, and the ferromagnetic thin film is magnetized in close contact with the magnetic disk surface. In magnetic transfer that records the magnetization pattern corresponding to the arrangement on the surface of the magnetic disk, it is possible to eliminate the influence on the transfer signal of foreign substances at the inner and outer peripheral edges that cannot be avoided in the magnetic disk manufacturing process, and by handling the master disk The effect is large with a simple configuration that can also eliminate the influence of the foreign matter adhering to the outer peripheral edge of the master disk on the transfer signal.

[Brief description of the drawings]

FIG. 1 is a plan view of a master disk according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the effect of the master disk.

FIG. 3 is a diagram showing an example of a magnetic servo pattern of a hard disk;

FIG. 4 is a partial cross-sectional view of a magnetic transfer master.

FIG. 5 is a partial perspective view of a conventional master disk.

FIG. 6 is a plan view of the same.

FIG. 7 is a diagram illustrating a magnetic transfer process.

FIG. 8 is a diagram illustrating a magnetic transfer process.

FIG. 9 is a view for explaining magnetization of a magnetic disk in a magnetic transfer process.

FIG. 10 is a view for explaining magnetization of a magnetic disk in a magnetic transfer process.

FIG. 11 is a view for explaining the principle of foreign matter inspection.

FIG. 12 is a view for explaining a foreign substance inspection of a magnetic disk;

FIG. 13 is a view for explaining a foreign substance inspection range of a magnetic disk.

FIG. 14 is a diagram illustrating magnetic transfer using a conventional master disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Master disk base 2 Ferromagnetic thin film 3 Master disk 4 Arrangement pattern part 5 Land part 6 Concave part 7 Magnetic disk 8 Spindle 9 Magnet 10 Unidirectional magnetization A 11 Pattern magnetization area 12 Unidirectional magnetization B 13 Laser beam 14 Regular reflection light 15 Scattering Light 16 Detector 17 Inspection area 18 Foreign matter 19 Vacuum pump

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Noriyuki Furumura 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inside the company (72) Keizo Miyata 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Seiwa Toma 1006 Odaka Kadoma, Kadoma City Osaka Pref. Document JP-A-2000-67433 (JP, A) JP-A-10-269566 (JP, A) JP-A-5-81671 (JP, A) JP-A-2001-266342 (JP, A) JP-A-2001-321820 (JP) JP-A-2001-297433 (JP, A) JP-A-2000-339670 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/62-5/86

Claims (3)

(57) [Claims] [Claim 1 further comprising a magnetic film formed on the array pattern corresponding to a Jo Tokoro information signals, prior to the magnetic disk surface
Serial A sequence pattern corresponding to the information signal by the magnetic film is in close contact with applying an external magnetic field in a master disk for transferring recorded on the magnetic disk surface, an outer diameter greater than the outer diameter of the magnetic disk Substrate having
A predetermined dimension from the outer diameter of the magnetic disk on the base
A radial land portion, which is provided only inside a small circular region, and in which the arrangement of the magnetic films is formed and is in close contact with the magnetic disk ;
The step is several micrometers to tens of micrometers.
A radial recess that does not adhere to the magnetic disk ;
Formed in the center of the disk and continuous with the radial recess
A central recess, and the magnetic field formed when the magnetic disk is brought into close contact with the magnetic disk.
The radial space surrounded by the disk and the recess
A master disk, which is opened outward at an outer peripheral end of the air disk . 2. An arrangement pattern corresponding to a predetermined information signal.
Using a master disk with a magnetic film formed in a shape
The magnetic film is brought into close contact with the magnetic disk
Array pattern corresponding to the information signal by applying a field
Transfer the magnetic recording disk to the surface of the magnetic disk.
Manufacturing method, wherein the master disk is larger than an outer diameter of the magnetic disk.
A substrate having a large outer diameter;
Provided inside a circular area smaller than the outer diameter of the disc by a predetermined dimension.
And an array of the magnetic films is formed and tightly adhered to the magnetic disk.
A radial land portion to be attached and a land formed between the land portions.
The step to the land from several micrometers
Close contact with the magnetic disk which is several tens of micrometers
There is no radial recess and the disc is formed in the center of the disc.
A magnetic concave portion having a radial concave portion and a continuous central concave portion.
The magnetic disk formed when the magnetic disk is
The radial space surrounded by the concave portion is
Opened outward at the outer peripheral end, the master disk is brought into close contact with the magnetic disk, and
By exhausting air from the central recess, the magnetic
Radiation surrounded by the disc and the recess of the master disc
Transfer recording in a state where an airflow is generated in a space
A method for manufacturing a magnetic disk. 3. A magnetic disk having a hole at a central portion, and in the step of bringing the master disk into close contact with the magnetic disk, an air flow is generated in the space by exhausting air from the hole. 3. The method for manufacturing a magnetic disk according to claim 2, wherein: