JP2001014673A - Magnetic transfer method and magnetic transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer high-grade transfer patterns from a master carrier for magnetic transfer to a slave medium regardless of the positions of magnetic patterns by magnetic transfer. SOLUTION: This magnetic transfer method consists of disposing a disposing a piece of a permanent magnet 8 by directing the end faces 9a and 9b of both magnetic poles toward a slave medium surface in such a manner that a magnetic field formed between both magnetic poles is impressed to the track direction of the slave medium surface when the slave medium 4 or the permanent magnet 8 is rotated in the track direction and the magnetic field is impressed to the surface of the slave medium and previously causing the initial DC magnetization of slave medium magnetization in the track direction, then bringing a master carrier for magnetic transfer and the slave medium 4 subjected to the initial DC magnetization into tight contact with each other and executing the magnetic transfer by impressing the magnetic field for transfer of the direction opposite to the initial DC magnetization direction of the slave medium surface in the track direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording a large amount of information at a time on a magnetic recording medium,
The present invention relates to a method for transferring recorded information to a magnetic recording medium having a high recording density.

[0002]

2. Description of the Related Art The amount of information handled by personal computers and the like has been dramatically increased due to the progress of use of digital images and the like. Due to the increase in the amount of information, there is a demand for a large-capacity, inexpensive magnetic recording medium for recording information and a short recording and reading time. High-density recording media such as hard disks, ZIP
In a high-density floppy (registered trademark) disk-type magnetic recording medium represented by (Iomega Co., Ltd.), the information recording area is composed of narrow tracks as compared with a general floppy disk. In order to scan the head and perform signal recording and reproduction at a high S / N ratio, it is necessary to perform accurate scanning using tracking servo technology.

Therefore, in a large-capacity magnetic recording medium such as a hard disk or a removable magnetic recording medium, a tracking servo signal, an address information signal, a reproduction clock signal, and the like are recorded at intervals within one rotation of the disk. The so-called pre-format has been done. The magnetic head can read the preformatted signal and correct its own position to accurately travel on the track.

The current preformat is manufactured by recording disks one by one and one track by using a dedicated servo recording device. There is a problem that the servo recording device is expensive, and it takes a long time to manufacture the preformat, so that it takes a long time to manufacture, which also affects the manufacturing cost. Therefore, a method of performing magnetic transfer without preformatting one track at a time has been proposed. For example, JP-A-63-183623, JP-A-10-4
Japanese Patent No. 0544 and Japanese Patent Application Laid-Open No. 10-269566 introduce a transfer technique. However, in the magnetic transfer method, no practical proposal has been made, including the conditions of the magnetic field applied during transfer and specific means for generating the magnetic field.

As a recording method for solving such a conventional problem, Japanese Unexamined Patent Publication (Kokai) No. 63-183623 and Japanese Unexamined Patent Publication (Kokai) No. 10-45544 discloses a method of forming a concavo-convex shape corresponding to an information signal on the surface of a substrate. The surface of the magnetic transfer master carrier in which the ferromagnetic thin film is formed on at least the convex surface of the uneven shape is brought into contact with the surface of the sheet-shaped or disk-shaped magnetic recording medium on which the ferromagnetic thin film or the ferromagnetic powder coating layer is formed, Alternatively, there has been proposed a method of recording a magnetization pattern corresponding to an uneven shape on a magnetic recording medium by applying an AC bias magnetic field or a DC magnetic field to excite a ferromagnetic material forming the surface of the convex portion.

In this method, the surface of the convex portion of the magnetic transfer master carrier is brought into close contact with the magnetic recording medium to be pre-formatted, that is, the slave medium, and at the same time, the ferromagnetic material constituting the convex portion is excited. This is a method by transfer to form a predetermined format. Recording can be performed statically without changing the relative position between the magnetic transfer master carrier and the slave medium, and accurate preformat recording is possible. It has the feature of. In addition, the time required for recording is very short. That is, in the method of recording from the above-described magnetic head, there is a problem that usually several minutes to several tens of minutes are required, and the time required for transfer becomes longer in proportion to the recording capacity. In this case, the transfer can be completed in one second or less regardless of the recording capacity and the recording density.

Referring to FIG. 1, transfer of a preformat pattern on a magnetic transfer master carrier will be described. FIG. 1A is a plan view schematically illustrating a magnetic layer surface of a magnetic transfer master carrier, and FIG. 1B is a cross-sectional view illustrating a transfer process. In a predetermined area of a track of the magnetic transfer master carrier 1, a preformat area 2 and a data area 3 in which patterns of a tracking servo signal and an address signal to be transferred are formed are formed. The preformat information can be transferred as recording information 7 to the slave medium side by applying a transfer external magnetic field 6 in the track direction 5 by bringing the slave medium 4 into close contact with the slave medium 4, so that the slave medium can be manufactured efficiently. Can be done. However, it has been clarified that when the transfer is performed by such a method, the information signal quality may be poor, and the servo operation may be inaccurate in some cases.

[0008]

SUMMARY OF THE INVENTION According to the present invention, the servo operation of a slave medium manufactured by transferring a preformat pattern by applying an external magnetic field while closely adhering a magnetic transfer master carrier and a slave medium becomes inaccurate. It is an object of the present invention to provide a stable transfer method and apparatus by preventing such a situation.

[0009]

According to the present invention, a master carrier for magnetic transfer, in which a magnetic layer is formed at a portion corresponding to an information signal on the surface of a substrate, is brought into close contact with a slave medium comprising a magnetic recording medium to be transferred. In the magnetic transfer method in which a transfer magnetic field is applied, the end faces of both magnetic poles of one permanent magnet face the slave medium surface, and the magnetic field formed between the two magnetic poles rotates the slave medium or the permanent magnet in the track direction. In this case, the magnetic recording medium is arranged so as to be applied in the track direction of the slave medium surface, a magnetic field is applied to the slave medium surface, the slave medium magnetization is initially DC-magnetized in the track direction in advance, and then the magnetic transfer master carrier is formed. A magnetic transfer in which a transfer medium is applied in a track direction opposite to the initial DC magnetization direction of the slave medium by closely adhering to the slave medium having the initial DC magnetization and performing magnetic transfer. It is the law.

A magnetic transfer master in which a magnetic layer is formed in a portion corresponding to an information signal on a surface of a substrate and a magnetic recording medium which is a slave medium receiving the transfer are brought into close contact with each other to apply a transfer magnetic field. In the method, a magnetic field is applied in the track direction on the surface of the slave medium, the magnetization of the slave medium is initially DC-magnetized in the track direction in advance, and then the master carrier for magnetic transfer is brought into close contact with the slave medium with the initial DC magnetization. With the end faces of both magnetic poles of one permanent magnet facing the slave medium surface, a magnetic field formed between the two magnetic poles is applied to the slave surface, and either the close contact member or the permanent magnet is rotated, and the slave This is a magnetic transfer method for performing magnetic transfer by applying a transfer magnetic field in a track direction opposite to the initial DC magnetization direction to a medium. The end faces of both magnetic poles of one permanent magnet are arranged facing the slave medium surface, and the magnetic field strength distribution of the magnetic field formed between the two magnetic poles in the track direction of the slave medium surface is greater than the coercive force _{Hcs of the} slave medium. The above magnetic transfer method has at least one magnetic field intensity portion at a position in the track direction.

When the end faces of both magnetic poles of one permanent magnet are disposed on at least one of the upper surface and the lower surface of the slave medium, the magnetic field intensity distribution in the track direction of the slave medium surface in the magnetic field formed by both magnetic poles is The magnetic field having a magnetic field strength portion _{equal to} or higher than the coercive force _Hcs of the slave medium in only one direction at the track direction position, and the magnetic field intensity in the opposite direction is less than the coercive force _{Hcs of the} slave at any track direction position. This is a transfer method.

The end faces of both magnetic poles of one permanent magnet are arranged facing the slave medium surface, and among the magnetic fields formed between the magnetic poles, the maximum value of the optimum transfer magnetic field strength range in the track direction magnetic field strength distribution is determined. Exceeding magnetic field intensity does not exist at any track direction position, and there is at least one portion in one track direction where the magnetic field intensity is within the optimum transfer magnetic field intensity range, and the magnetic field intensity in the opposite track direction is In the above magnetic transfer method, the value is less than the minimum value of the optimum transfer magnetic field strength range at any track direction position.
Optimal transfer magnetic field intensity is 0.6 × H _cs ~1.3 × H _cs The magnetic transfer method is.

A transfer magnetic field is applied by bringing a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on the surface of the substrate into close contact with a slave medium composed of a magnetic recording medium to be transferred. In a magnetic transfer device, 1
When the magnetic field formed between the two magnetic poles turns the slave medium or the permanent magnet in the track direction with the end faces of both magnetic poles of the two permanent magnets facing the slave medium surface, the magnetic field is generated in the track direction of the slave medium surface. Is applied, initial DC magnetizing means for initial DC magnetization of the slave medium in the track direction in advance, adhesion means for bringing the slave medium into close contact with the master carrier for magnetic transfer, and a direction opposite to the initial DC magnetization direction of the slave medium surface. This is a magnetic transfer device having a transfer magnetic field applying unit for applying a transfer magnetic field in a track direction.

A magnetic transfer apparatus for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on the surface of a substrate and a slave medium comprising a magnetic recording medium to be transferred. An initial DC magnetizing means for applying a magnetic field in the track direction of the surface of the slave medium to initially DC magnetize the magnetization of the slave medium carrier in the track direction in advance, and a contacting means for bringing the master medium for magnetic transfer into close contact with the slave medium having the initial DC magnetization. The end faces of both magnetic poles of one permanent magnet are disposed on at least one of the upper surface and the lower surface of the slave medium with facing the slave medium surface, and the slave medium or the permanent magnet is rotated in the track direction, and the The transfer magnetic field in the track direction opposite to the initial DC magnetization direction is applied by the magnetic field formed by both magnetic poles. A magnetic transfer device having a transfer magnetic field applying means. When the end faces of both magnetic poles of one permanent magnet are disposed on at least one of the upper surface and the lower surface of the slave medium with the end faces facing the slave medium surface, the magnetic field intensity distribution in the track direction of the magnetic field generated by the two magnetic poles is The above magnetic transfer apparatus has at least one magnetic field intensity portion having a coercive force _Hcs or more in a track direction position.

The magnetic field strength of the magnetic field generated by the magnetic poles of one permanent magnet in the track direction when the end faces of both magnetic poles are arranged on at least one of the upper surface and the lower surface of the slave medium with the end faces facing the slave medium surface. The distribution has a magnetic field intensity portion _{equal to} or higher than the coercive force _Hcs of the slave medium in only one direction in the track direction.
_The above magnetic transfer apparatus, wherein the _{cs is} less than _cs .

When the end faces of both magnetic poles of one permanent magnet are arranged on at least one of the upper surface and the lower surface of the slave medium with the end surfaces facing the slave medium surface, the magnetic field strength of the magnetic field generated by the magnetic pole of the permanent magnet in the track direction In the distribution, a magnetic field intensity exceeding the maximum value of the optimum transfer magnetic field strength range does not exist in any track direction position, and at least one portion having a magnetic field strength within the optimum transfer magnetic field strength range exists in one track direction. In the above magnetic transfer apparatus, the magnetic field strength in the opposite track direction is less than the minimum value of the optimum transfer magnetic field strength range at any track direction position. Optimum transfer magnetic field strength is 0.6 × H _cs
1.3 is the magnetic transfer apparatus of a × H _cs.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have found that when a transfer magnetic field is applied from the outside while a magnetic transfer master carrier and a slave medium are brought into close contact with each other, a portion where transfer is unstable and signal quality is reduced is generated. The present inventors have found that the reason is that the signal quality is degraded due to an inappropriate magnetic field applied at the time of transfer, and have arrived at the present invention. In magnetic transfer from the magnetic transfer master carrier to the slave carrier, when an external magnetic field higher than the holding force _Hcs of the slave medium is applied,
It has generally been considered that the magnetization state of the slave is all magnetized in the applied direction, so that the pattern to be originally transferred is not recorded. For example, JP-A-10-40
No. 544, also in paragraph number 0064,
It is described that it is preferable that the holding force be equal to or less than the holding force of the magnetic recording medium.

However, according to the study of the present inventors, the principle of the magnetic transfer in this method is as shown in FIG. 1, in which the convex magnetic layer portion of the magnetic transfer master carrier 1 substantially in contact with the slave medium 4. In this case, the transfer external magnetic field 6 becomes a magnetic field 6 a absorbed by the convex portion thereof, and does not have a magnetic field strength that can be recorded in the magnetic layer of the slave medium 4 in contact therewith. The magnetic layer of the slave medium 4 corresponding to the concave portion which is not formed has a recordable magnetic field intensity, and is magnetized in the direction of the transfer external magnetic field 6 as shown in FIG. It has been found that the pattern can be transferred as the recording information 7 to the slave medium 4.

Therefore, at the time of transfer from the magnetic transfer master carrier to the slave medium, the portion in contact with the slave medium has a large magnetic field entering the pattern portion of the magnetic transfer master carrier. Is the coercive force H _cs
It is considered that the reversal does not occur even if a higher transfer magnetic field is applied. Then, by applying a transfer magnetic field having a specific relationship strength as compared with the coercive force _{Hcs of the} slave medium, a slave medium with high signal quality can be obtained. The present inventors have generated various magnetic field patterns, repeated experiments, found application conditions for stably realizing clear transfer, and have accomplished the present invention.

In order to realize clear transfer in any pattern, the slave medium is _{subjected to} an initial DC magnetization with a sufficiently large magnetic field in one direction and a coercive force _Hcs or more, preferably 1.2 times _Hcs or more. A transfer magnetic field having a specific strength, that is, a magnetic field in an optimum transfer magnetic field strength range is applied. A preferable transfer magnetic field is 0.6 × H _cs ≦ transfer magnetic field ≦ 1.3 × H _cs . The direction is applied in a direction opposite to the direction of the initial DC magnetization. Also, transfer magnetic field is more preferably 0.8～1.2H _cs, more preferably 1 to 1.
Is a 1H _cs.

A magnetic recording medium for performing preformatting for servo is generally a disk-shaped recording medium, and records information along a track drawn concentrically from the center of rotation. In such a disk-shaped magnetic recording medium, a magnetic field application method of transferring a radial pattern is performed by applying a magnetic field in the track direction of the slave medium surface, that is, in the tangential direction of the circular arc at an arbitrary track direction position, and then preliminarily tracks the slave medium magnetization. Initial DC magnetization in the direction.

Next, the master carrier for magnetic transfer is brought into close contact with the slave medium which has been subjected to the initial DC magnetization, and a transfer magnetic field is applied in the track direction on the surface of the slave medium to perform magnetic transfer. It is necessary that the direction of the initial DC magnetization and the transfer magnetic field applied for performing the magnetic transfer are opposite to each other on the slave medium surface.

Therefore, in order to apply a magnetic field under the above-mentioned applied magnetic field condition over the entire surface of the disk-shaped medium, a magnetic field intensity distribution such that at least one magnetic field intensity portion in the track direction at least _{equal to} the coercive force _Hcs of the slave medium is provided. Is generated in a part of the track direction, and the slave medium or the magnetic field is rotated one turn in the track direction to realize the initial DC magnetization.

Further, has a coercive force H _cs or more field intensity portion of the slave medium in track direction position in only one direction, the opposite direction of the coercive force H _cs of the magnetic field strength slave medium at any track direction position By generating a magnetic field having a magnetic field intensity distribution such that the magnetic field intensity is less than a portion in the track direction and rotating the slave medium or the magnetic field once in the track direction, a magnetic field for initial DC magnetization of the slave medium magnetization in the track direction is applied in advance. can do.

A magnetic field intensity exceeding the maximum value of the optimum transfer magnetic field intensity range does not exist in any of the track direction positions, and at least one portion having a magnetic field intensity within the optimum transfer magnetic field intensity range in one track direction is provided. A magnetic field having a magnetic field intensity distribution such that the magnetic field intensity in the opposite track direction is less than the minimum value of the optimum transfer magnetic field intensity range at any position in the track direction is generated in a part of the track direction. It can also be realized by applying a transfer magnetic field in the track direction of the slave medium surface by rotating the master carrier and the initial DC magnetized slave carrier in the track direction while keeping them close together, or by rotating the magnetic field in the track direction. it can.

A transfer method and a transfer device will be described below with reference to the drawings. FIG. 2 is a view for explaining a transfer method and a transfer apparatus in which both magnetic poles of one permanent magnet are arranged on the slave medium surface with their end faces facing the slave medium surface.
FIG. 2A shows an example in which the slave medium is rotated while a magnetic field is applied on the upper surface of the slave medium 4 with the end faces 9a and 9b of both magnetic poles of the permanent magnet 8 facing the slave medium 4. From the end faces 9a and 9b of both magnetic poles of the single permanent magnet 8 provided on the upper surface of the slave medium 4, as shown in FIG.
Is applied, the slave medium or the permanent magnet is rotated in the track direction with respect to the center axis of the slave medium, and the surface of the slave medium as shown in FIG. A magnetic field having a peak 11 exceeding the coercive force _Hcs is applied to perform initial DC magnetization. In the example shown in FIG. 2, one permanent magnet is provided on the upper surface of the slave medium. However, the permanent magnet may be provided on the lower surface or on both surfaces.

Next, the pattern of the magnetic transfer master carrier can be transferred to the slave medium by bringing the slave medium into close contact with the magnetic transfer master carrier and applying a magnetic field in the direction opposite to the initial DC magnetization. In the present invention, the magnet used to apply a magnetic field to the slave medium or the closely adhered body of the slave medium and the magnetic transfer master carrier may be a U-shaped, horseshoe-shaped, arc-shaped, elliptical-arc-shaped magnet, or the like. The end faces of the magnetic poles are not limited to those parallel to the slave medium surface, but may be inclined.

FIG. 3 is a view for explaining an example of a permanent magnet in which the end faces of both magnetic poles of the permanent magnet are arranged facing the slave medium surface and a magnetic field can be applied to the slave medium by both magnetic poles. In the permanent magnet 8 shown in FIG. 3A, both end faces of the permanent magnet shown in FIG. 2 are parallel to the slave medium, while the end faces 9a and 9b of both magnetic poles are opposed to the slave medium face. it is obtained by inclined at an angle of inclination theta ₁ of the outward outward. The outward inclination angle θ ₁ is preferably 30 ° or less, and more preferably 10 ° or less.

The permanent magnet 8 shown in FIG. 3B is a permanent magnet in which the central axes of both magnetic poles are not parallel but intersect, while the permanent magnet shown in FIG. 2 is a U-shaped permanent magnet. Yes,
End faces 9 a and 9 b of both magnetic poles are parallel to slave medium 4. The relationship between the end faces of both magnetic poles and the slave medium 4 is the same as that shown in FIG. 2 except that the action surface for applying a magnetic field to the slave medium is the same as that shown in FIG. Has the effect of

The permanent magnet 8 shown in FIG.
The end faces 9a and 9b of both poles of the permanent magnet shown in FIG. 3B have an inward inclination angle θ ₂ inclined inward with respect to the surface of the slave medium 4. The inward inclination angle θ ₂ that forms the slave surface is preferably 90 ° or less, and more preferably 30 ° or less. In the permanent magnet shown in FIG. 3 (C), the central axes of both magnetic poles intersect, but the end faces of both magnetic poles of a U-shaped magnet whose central axes are parallel are inward. It may have an inclination angle.

The permanent magnet 8 shown in FIG. 3D has an elliptical shape as a whole, and the end faces 9 a and 9 b of both poles of the permanent magnet are inclined inward with respect to the surface of the slave medium 4. Has an inclination angle θ ₃ of. The inward inclination angle θ ₃ that forms the slave surface is 9 in the same manner as that shown in FIG.
It is preferably 0 ° or less, more preferably 30 ° or less.

The permanent magnet used for initial DC magnetization and magnetic transfer preferably has a size approximately equal to or greater than the distance from one end track to the other end track of the slave medium. It is preferable that the slave medium has a size approximately equal to or larger than the radial distance from the outermost track to the innermost track of the slave medium. By using the one having such a size, either the slave medium, the closely adhered body of the slave medium and the magnetic transfer master carrier, or the permanent magnet is moved in one direction over the entire length of the track or is rotated only once. Thus, a uniform magnetic field can be applied to the slave medium surface. In addition, the intensity of the magnetic field applied using a permanent magnet must be uniform at all track positions, and the magnitude of the variation should preferably be within ± 5% at all track positions, more preferably within ± 2.5%. Is more preferred.

FIG. 4 is a view for explaining a method of applying a magnetic field to a close contact body between the slave medium and the master carrier for magnetic transfer. FIG. 4A is a diagram illustrating the application of a magnetic field, and FIG. 4B is a diagram illustrating the strength of the magnetic field provided by the application of the magnetic field in FIG. When the transfer magnetic field 13 is applied to the contact body 12 with the end face of the magnetic pole of the U-shaped permanent magnet 8 facing the surface of the contact body 12 that is brought into close contact with the slave medium 4 and the magnetic transfer master carrier 1, By rotating the body or the permanent magnet in the track direction with respect to its central axis, a magnetic field in a direction opposite to the magnetization direction of the initial DC magnetization is provided.

The peak 14 having a small intensity in the magnetic field has no effect on the transfer of the pattern from the magnetic transfer master carrier to the slave medium, and only the peak 15 having a large intensity contributes to the magnetic transfer. . The peak 15 having a large intensity can form a good pattern irrespective of the shape of the pattern by applying a magnetic field within the optimum transfer magnetic field intensity range from the magnetic transfer master carrier to the slave medium. In addition, not only the permanent magnet shown in FIG. 4 but also various kinds of permanent magnets shown in FIG. 3 can be used to form a preferable transfer pattern by setting the strength of the transfer magnetic field to an appropriate magnitude. Become.

In the above description, a case has been described in which a permanent magnet is provided on one side of the slave medium surface to apply a magnetic field. However, permanent magnets are provided not only on one side of the slave medium surface but on both surfaces. It may be what you did.

The apparatus used for the magnetic transfer method shown in FIG. 4 is provided with a mechanism capable of arbitrarily adjusting the distance between the slave medium surface and the permanent magnet, so that the distance between the slave medium and the permanent magnet can be reduced. By adjusting the distance, the desired magnetic field strength can be obtained on the slave medium surface.

The method for producing the magnetic transfer master carrier used in the magnetic transfer of the present invention will be described. As a substrate for a magnetic transfer master carrier, a non-magnetic metal or alloy such as silicon, quartz plate, glass, and aluminum, a ceramic, a synthetic resin, or the like is a plate-like body having a smooth surface, and is used in etching and film forming processes. What has resistance to processing environments, such as temperature, can be used. A photoresist is applied to a substrate with a smooth surface, and is exposed and developed using a photomask according to the pattern of the preformat, or the photoresist is directly scribed. A corresponding pattern is formed.

Next, in the etching step, the substrate is etched in accordance with the pattern by an etching means for the substrate such as reactive etching, physical etching using argon plasma, etching using a liquid, or the like. The depth of the hole formed by etching is set to a depth corresponding to the thickness of the magnetic layer formed as the transfer information recording portion, and is preferably 20 nm or more and 1000 nm or less. If the thickness is too large, the spread width of the magnetic field increases, which is not desirable.

It is preferable that the hole to be formed has a uniform depth so that the bottom surface is formed by a plane parallel to the surface of the substrate. The hole preferably has a rectangular cross section in the track direction perpendicular to the surface.

Next, a vacuum deposition method such as a vacuum evaporation method, a sputtering method, and an ion plating method is used for the magnetic material.
A magnetic material is formed up to the surface of the substrate with a thickness corresponding to the hole formed by the plating method. The magnetic characteristics of the transfer information recording section are as follows: the coercive force (Hc) is 199 kA / m (2500 Oe).
Hereinafter, it is preferably 5 to 1500 Oe, and the saturation magnetic flux density (Bs) is 0.3 T (tesla) or more, preferably 0.5 T or more. Next, the photoresist is removed by a lift-off method, and the surface is polished to remove any flash, and the surface is planarized.

In the above description, a method of forming a hole in a substrate and depositing a magnetic material in the formed hole has been described. However, a film of a magnetic material is deposited at a predetermined position on the substrate by a photofabrication method. After forming the projections of the transfer information recording portion and, between the projections, a non-magnetic material is deposited or filled,
The surface of the transfer information recording section and the surface of the non-magnetic material section may be coplanar.

As a magnetic material that can be used for the magnetic layer, cobalt, iron, or an alloy thereof having a high magnetic flux density can be used. Specifically, Co,
CoPtCr, CoCr, CoPtCrTa, CoPt
CrNbTa, CoCrB, CoNi, Fe, FeC
o, FePt and the like. The thickness of the magnetic layer is 20 to 1000 nm, preferably 30 to 500 nm. If it is too thick, the recording resolution decreases.

In particular, it is clear that the magnetic flux density is large and the magnetic medium has magnetic anisotropy in the same direction as the slave medium, for example, in the in-plane direction for in-plane recording and in the perpendicular direction for perpendicular recording. It is preferable for the transfer to be performed. It is preferable that the magnetic material has fine magnetic particles or an amorphous structure from the viewpoint that a sharp edge can be formed.

In order to form the magnetic material with magnetic anisotropy, it is preferable to provide a non-magnetic underlayer, and it is necessary that the crystal structure and lattice constant are the same as those of the magnetic layer. Specifically, as such an underlayer, C
r, CrTi, CoCr, CrTa, CrMo, NiA
1, Ru, or the like can be formed by sputtering.

Further, a protective film such as a diamond-like carbon film may be provided on the magnetic layer, and a lubricant may be provided. More preferably, a 5 to 30 nm diamond-like carbon film and a lubricant are present as a protective film. The reason why it is necessary to provide a lubricant thereon is that friction occurs when correcting a displacement occurring in the process of contact with the slave, and durability is insufficient without a lubricant layer.

The magnetic transfer master carrier of the present invention can be used not only for transferring magnetically recorded information to a disk-type magnetic recording medium such as a hard disk or a large-capacity removable magnetic recording medium, but also for a card-type magnetic recording medium or a tape-type magnetic recording medium. It can also be used to transfer magnetically recorded information to a medium.

[0047]

The present invention will be described below with reference to examples. Example 1 and Comparative Example 1 (Preparation of Magnetic Transfer Master Carrier) In a vacuum film forming apparatus, the pressure was reduced to 1.33 × 10 ⁻⁵ Pa (10 ⁻⁷ Torr) at room temperature, and argon was introduced thereinto. 0.4 Pa (3 × 1
0 ^-3 Torr) on a silicon substrate.
An FeCo film having a thickness of 0 nm was formed to obtain a 3.5-type disk-shaped master carrier for magnetic transfer. Coercive force Hc is 8 kA / m
(100 Oe), and the magnetic flux density Ms is 28.9T (2300T).
0 Gauss). Radial lines of 10μ width from the center of the disk to the position of 20mm to 40mm in the radial direction from the center of the disk.
At the innermost peripheral position of 10 μm.

(Preparation of Slave Medium) In a vacuum film forming apparatus, the pressure was reduced to 1.33 × 10 ⁻⁵ Pa (10 ⁻⁷ Torr) at room temperature, and then argon was introduced to obtain 0.4 Pa (3 × 10 −3 Torr).
Under a condition of 10 ⁻³ Torr, the glass plate was heated to 200 ° C., and CoCrPt 25 nm, Ms: 5.7 T (450
0Gauss), the coercive force H _cs: 199kA / m (250
A 3.5-inch disk-shaped magnetic recording medium (0 Oe) was produced.

(Initial DC magnetization method) The coercive force _{Hcs of the} slave medium at the surface of the slave medium
The permanent magnet was arranged as shown in FIG. 2 so as to be 388 kA / m (5000 Oe) twice as large as that of FIG.

(Magnetic Transfer Test Method) The slave medium which was initially DC-magnetized and the magnetic transfer master carrier were brought into close contact with each other.
Using the apparatus having a permanent magnet shown in FIG. 4, magnetic transfer was performed by applying a voltage in the direction opposite to the magnetization of the slave medium. Also, the close contact between the magnetic transfer master carrier and the slave medium
Pressure was applied from above the aluminum plate across the rubber plate.

(Electromagnetic Conversion Characteristic Evaluation Method) The transfer signal of the slave medium was evaluated using an electromagnetic conversion characteristic measuring device (SS-60 manufactured by Kyodo Electronics). The head has a reproducing head gap: 0.31 μm, a reproducing track width: 1.8 μm,
Recording head gap: 0.4 μm, recording track width:
A 3.0 μm MR head was used.

The read signal was frequency-decomposed by a spectroanalyzer, and the difference (C / N) between the peak intensity (C) of the primary signal and the extrapolated medium noise (N) was measured. Of C / N at each magnetic field strength, the maximum value is set to 0 dB, and the relative value (△ C /
N) and the results are shown in Table 1. Note that the C / N value is-
In the case of 20 dB or less, the signal quality of the magnetic transfer is not at a practical level, and is indicated by *.

[0053]

Table 1 The ratio of the peak intensity of H _cs 199 kA / m magnetic field for transfer of the slave medium kA / m Hcs △ C / N (dB) 59.7 0.3 * 99.5 0.5 -15.8 119 0.6-5.2 159 0.8 -1.9 179 0.9 -1.2 199 1.0 0.0 219 1.1 -0.3 239 1.2 -3.5 259 1.3 -3.5 279 1.4 -4.9 298 1.5 -8.6 318 1.6 -16.3 398 2.0 *

[0054] the slave medium of Example 2 and Comparative Example 2 coercivity H _cs is 199kA / m (2500Oe), the peak magnetic field strength 239 kA / m (3000
Oe), that is, the coercive force _Hcs of the slave medium is 1.2.
Example 1 except that the initial DC magnetization of the slave medium was performed at twice the magnetic field strength, and then the magnetic transfer was performed by closely contacting the initial DC-magnetized slave medium and the magnetic transfer master carrier.
After magnetic transfer was performed in the same manner as in Example 1, the measurement was performed in the same manner as in Example 1. The results are shown in Table 2. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution shown in FIG.

[0055]

TABLE 2 The ratio of the peak intensity of H _cs 199 kA / m magnetic field for transfer of the slave medium kA / m Hcs △ C / N (dB) 59.7 0.3 * 99.5 0.5 -12.8 119 0.6 -3.1 159 0.8 -0.2 179 0.9 0.0 199 1.0 -0.2 219 1.1 -0.3 239 1.2 -2.9 259 1.3 -3.5 279 1.4 -6.8 298 1.5 -19.2 318 1.6 * 398 2.0 *

[0056] The slave medium in Comparative Example 3 coercivity H _cs is 199kA / m (2500Oe), the peak magnetic field strength 159 kA / m (2000
Oe), that is, 0.8 of the coercive force _Hcs of the slave medium.
Example 1 except that the initial DC magnetization of the slave medium was performed at twice the magnetic field strength, and then the magnetic transfer was performed by closely contacting the initial DC-magnetized slave medium and the magnetic transfer master carrier.
After performing the magnetic transfer in the same manner as in Example 1, the measurement was performed in the same manner as in Example 1. The results are shown in Table 3. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution shown in FIG.

[0057]

[Table 3] H _{cs of} slave medium 199 kA / m Ratio to peak intensity kA / m Hcs of transfer magnetic field ΔC / N (dB) 59.7 0.3 * 99.5 0.5 * 119 0.6 * 159 0.8 * 179 0.9 * 199 1.0 * 219 1.1 * 239 1.2 * 259 1.3 * 279 1.4 * 298 1.5 * 318 1.6 * 398 2.0 *

[0058] Example 3 and Comparative Example 4 Example 1 coercivity H _cs which was prepared in the same manner as is 159kA
A slave medium / m (2000 Oe), the peak magnetic field strength 318 kA / m (4000 Oe), i.e. perform initial DC magnetization of the slave medium at twice the field strength of H _cs coercivity of the slave medium, then initial DC The magnetic transfer was performed in the same manner as in Example 1 except that the magnetized slave medium and the master carrier for magnetic transfer were brought into close contact with each other, and magnetic transfer was performed using the apparatus shown in FIG. The measurement was performed in the same manner, and the results are shown in Table 4. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution shown in FIG.

[0059]

[Table 4] H _{cs of} slave medium 159 kA / m Ratio of peak intensity of transfer magnetic field to kA / m Hcs ΔC / N (dB) 47.7 0.3 * 79.6 0.5 -10.2 95 0.5 0.6 -2.3 127 0.8 -0.9 143 0.9 -0.2 159 1.0 0.00.0 175 1.1 -0.9 191 1.2 -1.1 207 1 3.3-3.1 223 1.4-9.6 239 1.5-16.5 255 255 1.6 * 318 2.0 *

[0060] peak magnetic field strength to the slave medium of Example 4 and Comparative Example 5 coercivity H _cs is 159kA / m (2000Oe) is 191kA / m (2400O
e) In other words, the initial DC magnetization of the slave medium was performed in the same manner as in Example 1 except that the initial DC magnetization of the slave medium was performed at a magnetic field strength of 1.2 times the coercive force _Hcs of the slave medium. Magnetic transfer was performed with the master carrier in close contact, and the measurement was performed in the same manner as in Example 1. The results are shown in Table 5. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution shown in FIG.

[0061]

Table 5 H _{cs of} slave medium 159 kA / m Ratio of peak intensity of transfer magnetic field to kA / m Hcs ΔC / N (dB) 47.7 0.3 * 79.6 0.5 -12.4 95 0.5 0.6 -4.3 127 0.8 -0.9 143 0.9 -0.1 159 1.0 0.0 175 1.1 0.0 191 1.2 -1.3 207 1. 3-9.2 223 1.4-19.6 239 1.5 * 255 1.6 * 318 2.0 *

[0062] Comparative Example 6 Example 1 coercivity H _cs which was prepared in the same manner as is 159kA
A slave medium / m (2000 Oe), the peak magnetic field strength 127 kA / m (1600 Oe), i.e. perform initial DC magnetization of the slave medium at 0.8 times the magnetic field strength H _cs coercivity of the slave medium, then After the magnetic transfer was performed in the same manner as in Example 1 with the slave medium that had been subjected to the initial DC magnetization closely contacted with the master carrier for magnetic transfer, measurement was performed in the same manner as in Example 1, and the results are shown in Table 6. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution shown in FIG.

[0063]

[Table 6] slave medium H _cs 159 kA / m magnetic field for transfer ratio of the peak intensity kA / m Hcs of △ C / N (dB) 47.7 0.3 * 79.6 0.5 * 95.5 0 6.6 * 127 0.8 * 143 0.9 * 159 1.0 * 175 1.1 * 191 1.2 * 207 1.3 * 2231.4 * 2391.5 * 2551.6 * 3182 0.0 *

[0064]

According to the present invention, in magnetic transfer from a magnetic transfer master carrier to a slave medium, a high-quality transfer magnetic field having a specific strength is applied to _Hcs of the slave medium, thereby achieving high quality regardless of the position and shape of the pattern. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining transfer of a preformat pattern on a magnetic transfer master carrier.

FIG. 2 is a diagram illustrating a method of applying a magnetic field in which two permanent magnets are arranged adjacent to one surface of a slave medium surface.

FIG. 3 is a diagram illustrating an example of a permanent magnet in which both magnetic poles are arranged so that end faces of both magnetic poles face a slave medium surface and a magnetic field can be applied to the slave medium by both magnetic poles;

FIG. 4 is a diagram for explaining a method of transferring from a magnetic transfer master carrier to a slave medium.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Master carrier for magnetic transfer, 2 ... Preformatted area, 3 ... Data area, 4 ... Slave medium, 5 ... Track direction, 6 ... External magnetic field for transfer, 6a ... Magnetic field absorbed by a convex part, 7 ... Recording information , 8: permanent magnets, 9a, 9b: end faces of both magnetic poles, 10: magnetic field in the track direction, 11: peak, 1
2: Close contact body, 13: Transfer magnetic field, 14: Small intensity peak, 15: High intensity peak

Claims (12)

[Claims] 1. A magnetic device for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a slave medium comprising a magnetic recording medium to be transferred. In the transfer method, when the magnetic field formed between the two magnetic poles turns the slave medium or the permanent magnet in the track direction with the end faces of both magnetic poles of one permanent magnet facing the slave medium surface, the slave medium surface After applying a magnetic field to the surface of the slave medium and initial DC magnetization of the slave medium magnetization in the track direction in advance, the master carrier for magnetic transfer and the slave medium with the initial DC magnetization are applied. A magnetic transfer method, wherein the magnetic transfer is performed by applying a transfer magnetic field in a track direction opposite to an initial DC magnetization direction of a slave medium in close contact with the slave medium. 2. A magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a magnetic recording medium serving as a slave medium receiving transfer are brought into close contact with each other.
In the magnetic transfer method of applying a transfer magnetic field, a magnetic field is applied in the track direction of the slave medium surface, the slave medium magnetization is initially DC-magnetized in the track direction, and then the magnetic transfer master carrier and the initial DC-magnetized slave medium are separated. With the end faces of both magnetic poles of one permanent magnet facing the slave medium surface, a magnetic field formed between the two magnetic poles is applied to the slave surface with respect to the adhered body, and the permanent body or the permanent magnet is contacted. And performing a magnetic transfer by applying a transfer magnetic field in a track direction opposite to the initial DC magnetization direction to the slave medium. 3. An end face of both magnetic poles of one permanent magnet is arranged facing a slave medium surface, and a magnetic field strength distribution of a magnetic field formed between the two magnetic poles in a track direction of the slave medium surface is maintained in the slave medium. 2. The magnetic transfer method according to claim 1, wherein the magnetic transfer method has at least one magnetic field strength portion having a magnetic force _Hcs or more at a position in the track direction. 4. The magnetic field strength in the track direction of the slave medium surface out of the magnetic field formed by the two magnetic poles when the end faces of both magnetic poles of one permanent magnet are disposed on at least one of the upper surface and the lower surface side of the slave medium. The distribution has a magnetic field intensity portion _{equal to} or higher than the coercive force _Hcs of the slave medium in only one direction at the track direction position, and the magnetic field intensity in the opposite direction is less than the slave coercive force _Hcs at any track direction position. The magnetic transfer method according to claim 1, wherein: 5. An end face of both magnetic poles of one permanent magnet is arranged facing a slave medium surface, and among magnetic fields formed between the two magnetic poles, in a track direction magnetic field strength distribution, a maximum of an optimum transfer magnetic field strength range. There is no magnetic field strength exceeding the value in any of the track direction positions, and at least one portion having a magnetic field strength within the optimum transfer magnetic field strength range in one track direction.
3. A magnetic field intensity in a track direction which is present in more than one place and is opposite to the minimum value in the optimum transfer magnetic field intensity range at any position in the track direction.
3. The magnetic transfer method according to item 1. 6. An optimum transfer magnetic field intensity is 0.6 × H _cs -1.
The magnetic transfer method according to claim 5, wherein the value is 3 × H _cs . 7. A transfer magnetic field is applied by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a slave medium made of a magnetic recording medium to be transferred. In the magnetic transfer device, the end faces of both magnetic poles of one permanent magnet are directed to the slave medium surface,
When the magnetic field formed between the magnetic poles rotates the slave medium or the permanent magnet in the track direction, a magnetic field is applied in the track direction on the surface of the slave medium, so that the slave medium magnetization is initially DC-magnetized in the track direction. Initial DC magnetizing means, an adhesion means for bringing the slave medium into close contact with the magnetic transfer master carrier, and a transfer magnetic field applying means for applying a transfer magnetic field in a track direction opposite to the initial DC magnetization direction of the slave medium surface. Characteristic magnetic transfer device. 8. A magnetic field for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a slave medium comprising a magnetic recording medium to be transferred. In the transfer device, a magnetic field is applied in the track direction of the slave medium surface, and an initial DC magnetizing means for initial DC magnetization of the slave medium carrier in the track direction in advance, and the master carrier for magnetic transfer is brought into close contact with the initial DC magnetized slave medium. The contact means is disposed on at least one of the upper surface and the lower surface of the slave medium with the end faces of both magnetic poles of one permanent magnet facing the slave medium surface, and the slave medium or the permanent magnet is rotated in the track direction, and the permanent A magnetic field formed by both poles of the magnet applies a transfer magnetic field in a track direction opposite to the initial DC magnetization direction. A magnetic transfer apparatus comprising: a transfer magnetic field applying unit. 9. A magnetic field intensity in a track direction of a magnetic field generated by the two magnetic poles when the end faces of both magnetic poles of one permanent magnet are arranged on at least one of the upper surface and the lower surface of the slave medium with the end surfaces facing the slave medium surface. _8. The magnetic transfer apparatus according to claim 7, wherein the magnetic recording apparatus has at least one magnetic field intensity portion having a distribution higher than the coercive force _Hcs of the slave medium in the track direction. 10. A magnetic field generated by magnetic poles of one permanent magnet in a track direction when end faces of both magnetic poles are disposed on at least one of an upper surface and a lower surface of the slave medium with facing the slave medium surface. The magnetic field strength distribution has a magnetic field strength portion higher than the coercive force _{Hcs of the} slave medium in only one direction in the track direction, and the magnetic field strength in the opposite direction is less than the coercive force _{Hcs of the} slave medium at any position in the track direction. The magnetic transfer apparatus according to claim 7, wherein 11. A magnetic field generated by the magnetic poles of one permanent magnet in the track direction when the end faces of both magnetic poles are disposed on at least one of the upper surface and the lower surface of the slave medium with facing the slave medium surface. In the magnetic field strength distribution, no magnetic field strength exceeding the maximum value of the optimum transfer magnetic field strength range exists in any of the track direction positions, and at least one portion of the magnetic field strength within the optimum transfer magnetic field strength range becomes one track direction in one track direction. 9. The magnetic transfer apparatus according to claim 8, wherein the magnetic field intensity in the track direction that exists and is opposite to this is less than the minimum value of the optimum transfer magnetic field intensity range at any position in the track direction. 12. An optimum transfer magnetic field strength of 0.6 × H _cs or _less .
The magnetic transfer apparatus according to claim 11, wherein the value is 1.3 x _Hcs .