JP4316573B2 - Degaussing mask medium and perpendicular recording medium magnetic transfer / demagnetization method - Google Patents

Description

  The present invention relates to a demagnetization mask medium and a perpendicular recording medium magnetic transfer / demagnetization method, and more particularly, to a configuration for an initial demagnetization method of a data area in a magnetic transfer system in which servo information is recorded collectively on a perpendicular magnetic recording medium. The present invention relates to a degaussing mask medium and a perpendicular recording medium magnetic transfer / demagnetization method.

  In recent years, as the recording density of magnetic recording devices has increased, there is a concern about the increase in servo write time and the deterioration of servo recording accuracy in servo information recording by conventional head recording.

Thus, a magnetic transfer system that records servo information in a batch using a mask medium on which servo information has been patterned in advance has attracted attention.
According to this magnetic transfer system, time cost can be greatly reduced because of batch recording, and high-precision servo recording can be expected because of static recording.

  On the other hand, with respect to the magnetic recording medium, perpendicular recording is progressing in place of the conventional in-plane recording medium, and there are a magnetic transfer system in which a magnetic field is applied horizontally to the medium and a perpendicular application system.

  The transfer method in which a magnetic field is applied vertically is a method in which an initializing magnetic field is applied in a direction perpendicular to the medium surface, and then a mask medium is brought into close contact, and a magnetic field is applied in a direction opposite to the initialization to transfer a servo pattern.

  At this time, the region other than the transfer portion covers a wide range, and the magnetization remains uniformly in the initialization magnetic field direction or the transfer magnetic field direction. In other words, a desired servo pattern is transferred to the servo area, but the data area is DC demagnetized (DC erased).

  If this DC erase portion is concentrated in a wide area, a strong magnetic field is generated from the portion in the vertical direction. Generally, in a perpendicular recording magnetic disk apparatus, when recording data with a head, the magnetic field is adversely affected. It has become a problem to deteriorate.

Therefore, it is desirable that the data portion is AC erased so that a magnetic field in one direction is not concentrated.
For example, in a conventional servo information recording method using head recording, AC erase is performed using a write head on a data area between servo pattern transfer portions in a vertical recording medium (see, for example, Patent Document 1). .
JP 2002-230734 A

  However, in the present situation where almost no perpendicular magnetic recording medium is commercially available, the demagnetization method of the perpendicular magnetic recording medium mounted on the commercially available perpendicular magnetic recording apparatus is unknown, and in the magnetic transfer system also in the literature, There is a problem that an appropriate demagnetization method has not been proposed.

  Even in the magnetic transfer method, if the write erase is used to perform the AC erase on the data area between the servo pattern transfer portions, the feature of the magnetic transfer method, which is a significant reduction in time cost, is lost. There is a problem of being broken.

  Accordingly, an object of the present invention is to collectively perform degaussing on a data area between servo pattern transfer portions with a simple configuration.

FIG. 1 is a diagram illustrating the basic configuration of the present invention. Means for solving the problems in the present invention will be described with reference to FIG.
In order to solve the above-described problem, the present invention provides a demagnetization mask medium 3 in which the base material 4 is made of a transparent member transparent to laser light used for demagnetization, and the perpendicular recording medium 1 The mask portion 5 that completely covers the servo pattern transfer portion 2 is made of a magnetic film, and no magnetic film is present in the user data portion of the perpendicular recording medium 1 .

  In this way, by configuring the mask portion 5 that completely covers the servo pattern transfer portion 2 of the perpendicular recording medium 1 from the magnetic film, the servo pattern transfer portion 2 can be magnetically shielded, and therefore the magnetic field can be collectively collected. Thus, even if the data portion is demagnetized by application, the transfer data of the servo pattern transfer portion 2 is not demagnetized, so that the demagnetization process can be performed in a short time and at a low cost.

Further, since a transparent member is used as the base material 4 constituting the demagnetization mask medium 3 in this case, demagnetization by laser irradiation, which will be described later, and demagnetization by magnetic field application can be performed together. A close state can be realized.

  Further, the mask part 5 that completely covers the servo pattern transfer part 2 is created using mask data automatically generated from the servo pattern data, thereby simplifying the process of creating the mask part 5, thereby enabling the servo pattern transfer. A solid pattern that fills the inside of the contour portion of the portion 2 is formed.

  In this case, the mask portion 5 may be configured to have a margin portion of 10% or less of the shortest width of the contour portion of the servo pattern transfer portion 2 at both ends of the mask portion 5, whereby the servo pattern transfer portion The servo information 2 is not erroneously erased due to a mask alignment error.

Further, as a perpendicular recording medium magnetic transfer / demagnetization method, a perpendicular magnetic surface of the perpendicular recording medium 1 is perpendicularly applied by applying a magnetic field in a state of being in close contact with the perpendicular recording medium 1 using a mask medium on which servo information is previously patterned. After the servo pattern is transferred in the direction, the perpendicular recording medium is used in the state where the demagnetization mask medium 3 described above is used and the mask portion 5 of the demagnetization mask medium 3 and the transfer pattern portion are aligned and brought into close contact with each other. It is only necessary to demagnetize the vertical vertical magnetization in the user data portion of the perpendicular recording medium 1 by applying a magnetic field in the horizontal direction of 1 medium and irradiating laser light from the demagnetization mask medium side in the vertical direction of the medium surface .

  In this case, it is desirable that initialization is performed so that the magnetization direction of the perpendicular recording medium 1 is opposite to the magnetization direction of the servo pattern transfer unit 2 before transferring the servo information. Can be improved.

  In this case, the magnetic field application and the laser irradiation may be performed simultaneously, or may be performed by a sequential method in which one is performed first and the other is performed subsequently.

  By providing the perpendicular recording medium 1 in which the servo pattern is recorded by the above-described perpendicular recording medium magnetic transfer / demagnetization method and the vertical and vertical magnetizations of the data portion are demagnetized, an inexpensive perpendicular recording medium 1 is provided. can do.

  In addition, by mounting such a perpendicular recording medium 1, a magnetic disk device having a high recording density can be provided at a low cost.

  According to the present invention, since the degaussing of the data area between the servo pattern transfer portions can be performed at once, the servo pattern transfer that makes full use of the advantages of the magnetic transfer method becomes possible, thereby enabling high density recording. A possible perpendicular recording medium or a magnetic disk device equipped with the perpendicular recording medium can be provided at low cost.

In the present invention, a servo pattern is transferred in the direction perpendicular to the medium surface of the perpendicular recording medium by applying a magnetic field in a state of being in close contact with the perpendicular recording medium 1 using a mask medium in which servo information is patterned in advance, and then the servo is transferred. Using a demagnetization mask medium whose mask part completely covers the pattern transfer part is made of a magnetic film, aligning the mask part of the demagnetization mask medium and the transfer pattern part and bringing them into close contact or in close proximity with each other, the perpendicular recording medium A magnetic field is applied in the medium horizontal direction and laser light is irradiated from the demagnetization mask medium side in the medium surface vertical direction to demagnetize the vertical vertical magnetization in the user data portion of the perpendicular recording medium.

  In this case, it is desirable that initialization is performed so that the magnetization direction of the perpendicular recording medium is opposite to the magnetization direction of the servo pattern transfer unit 2 before the servo information is transferred.

  The mask part that completely covers the servo pattern transfer part is preferably created using mask data automatically generated from the servo pattern data, and the inside of the contour part of the servo pattern transfer part thus created is filled. A solid pattern, in particular, a solid pattern configured to have a margin portion of 10% or less of the shortest width of the contour portion of the servo pattern transfer portion at both ends of the mask portion is used.

Here, with reference to FIG. 2 and FIG. 6, the perpendicular recording medium magnetic transfer / demagnetization method of Reference Example 1 , which is a premise of the present invention, will be described.
FIG. 2 is an explanatory diagram of the configuration of the servo recording mask medium, in which the upper diagram is a schematic plan view and the lower diagram is a schematic sectional view of the main part.
In this servo recording mask medium 10, a groove 13 having a depth of several hundreds of nanometers for forming a servo pattern 12 is formed on a silicon substrate 11 using a resist pattern (not shown), and then a magnetic material having a high magnetic permeability. After a body film, for example, a CoFe film 14 is deposited by sputtering, unnecessary portions are removed by lift-off, and the CoFe film 14 is embedded in the groove 13.

  The servo pattern 12 is arranged so as to draw arcs corresponding to the servo sectors, and each arc is composed of fine servo data patterns 15. A resist pattern is formed by exposure.

FIG. 3 is an explanatory diagram of the configuration of the servo unit mask medium. The upper diagram is a schematic plan view, and the lower diagram is a schematic sectional view of the main part.
In the servo unit mask medium 20, a groove 23 having a depth of several hundreds of nanometers is formed on a silicon substrate 21 at a position where the servo pattern 12 is masked by using a resist pattern (not shown), and then a magnetic material having high permeability. After the body film, for example, the CoFe film 24 is deposited by sputtering, unnecessary portions are removed by lift-off, and the mask pattern 22 is formed by embedding the CoFe film 24 in the groove 23.

  In this case, the thickness of the CoFe film 24 is preferably as thick as possible for the magnetic shield effect. However, if the thickness is too large, the flatness of the surface is lost, and it becomes difficult to make it adhere to the perpendicular magnetic recording medium. The depth is such that the demagnetization condition is optimized by the balance between them.

  The mask pattern 22 is composed of a mask data pattern along the outer contour of the servo data, and margin areas 26 of 10% or less of the width of the mask area 25 are provided on both sides of the mask area 25 as necessary. Provide.

  That is, since the pattern density is high in the servo part and is basically zero in the data part, this feature is used to mask all the drawing data by searching the start position and end position of the servo pattern part. It is only necessary to automatically recognize the power region (arc-shaped band range) and automatically generate mask data.

Next, a perpendicular recording medium magnetic transfer / demagnetization process using the above-described servo recording mask medium and servo section mask medium will be described.
4 First, electromagnets 32 and 33 for applying a perpendicular magnetic field to the surface of the perpendicular magnetic recording medium 40 are provided for the perpendicular magnetic recording medium 40 fixed to the spindle motor 31, and the perpendicular magnetic recording medium 40 is provided. The magnetic recording layer 41 is initialized in the vertical direction (upward in the drawing) by applying a magnetic field twice or more of the coercive force _Hc of the magnetic recording layer 41.

Next, after the magnetic recording layer 41 is brought into close contact with the initialization surface of the servo recording mask medium 10 on the side where the CoFe film 24 is provided, the current flowing through the electromagnets 32 and 33 is reversed to be initialized. The servo pattern 12 is formed by transferring the servo pattern 12 to the magnetic recording layer 41 by applying a magnetic field in the direction opposite to the forming direction.
In this case, the magnetic field strength is set to be the same as the coercive force Hc of the magnetic recording layer 41, for example.

Next, the mask pattern 22 provided on the servo unit mask medium 20 is aligned and brought into close contact with the servo pattern writing area 42 of the magnetic recording layer 41 so as to completely cover the servo pattern writing area 42. After that, while rotating the perpendicular magnetic recording medium at a low speed, a magnetic field is applied in the horizontal direction of the medium surface using the electromagnet 34 to demagnetize the magnetic field of the data portion 43 in a random state close to AC erase.

The magnetic field strength in this case is, for example, 1 to 2 times the coercive force Hc of the magnetic recording layer 41.
The alignment in this case is performed by providing alignment marks on both the magnetic recording layer 41 and the servo unit mask medium 20 and optically confirming the alignment.

  In this demagnetization process, the servo pattern writing area 42 is magnetically shielded by the mask pattern 22 that is in close contact with the servo pattern writing area 42, so that the information in the servo pattern writing area 42 is not demagnetized.

  In the figure, for the sake of illustration, the electromagnet 34 is sized to cover a part of one servo pattern writing area 42, but may be sized to cover the whole or a small electromagnet. Demagnetization may be performed while moving 34 in the radial direction of the perpendicular magnetic recording medium 40.

Thus, in the reference example 1 of the present invention, since the demagnetization is performed collectively using the servo unit mask medium 20 having the mask pattern 22, as compared with the method of demagnetizing the data unit with the conventional drive magnetic head, A simple extension of the transfer process is required, and time costs can be reduced.

Next, a perpendicular recording medium magnetic transfer / demagnetization method according to Reference Example 2 , which is a premise of the present invention, will be described with reference to FIGS.
FIG. 7 is an explanatory diagram of the configuration of the servo unit mask medium used in Reference Example 2. The upper diagram is a schematic plan view, and the lower diagram is a schematic sectional view of an essential part.
The servo unit mask medium 50 is formed by applying a photoresist to a transparent glass substrate 51, exposing and developing a data pattern along the outer contour of servo data automatically generated from a servo pattern in advance, and then shielding the mask pattern 52. As necessary, margin areas 54 of 10% or less of the width of the mask area 53 are provided on both sides of the mask area 53 as needed.

Next, a perpendicular recording medium magnetic transfer / demagnetization process using the above-described servo recording mask medium and servo section mask medium will be described.
First, in exactly the same manner as in Reference Example 1 described above, an electromagnet for applying a perpendicular magnetic field to the surface of the perpendicular magnetic recording medium 40 is provided on the perpendicular magnetic recording medium 40 fixed to the spindle motor 31 so as to be perpendicular. initialize the magnetic recording layer 41 in the vertical direction by applying a magnetic field of more than twice the coercivity H _c of the magnetic recording layer 41 of the magnetic recording medium 40.

Next, after the magnetic recording layer 41 is brought into close contact with the initialization surface of the above-described servo recording mask medium on which the CoFe film is provided, the current flowing in the electromagnet is reversed to reverse the magnetic field in the direction opposite to the initialization direction. Is applied to transfer the servo pattern to the magnetic recording layer 41 to form the servo pattern writing area 42.
Magnetic field strength in this case is, for example, be the same as the coercive force H _c of the magnetic recording layer 41.

Next, the mask pattern 52 provided on the servo unit mask medium 50 is aligned with the servo pattern writing area 42 of the magnetic recording layer 41 so as to completely cover the servo pattern writing area 42, and then perpendicular Demagnetization is performed by irradiating the laser beam 35 while rotating the magnetic recording medium at a low speed so that the magnetic field of the data portion 43 is in a random state close to AC erase.
The alignment in this case is performed by providing alignment marks on both the magnetic recording layer 41 and the servo unit mask medium 20 and optically confirming the alignment.

In this demagnetization process, a laser power of 85 mJ / cm ² or more is irradiated using a pulse laser.
As the laser to be used, the second harmonic, the third harmonic of the YAG laser, or various lasers such as an excimer laser, an Ar laser, and a ruby laser can be used.

In this demagnetization process, the servo pattern writing area 42 covered with the mask pattern 52 is shielded from the laser beam 35, so that the previously transferred servo pattern is held as it is.
On the other hand, since the laser beam 35 is irradiated to the data portion 43 where the light shielding portion does not exist, heat is applied to that portion, and the magnetic film constituting the magnetic recording layer 41 reaches the Curie point, so that the medium is close to AC erase. It becomes a magnetized state.

Based on the above, the perpendicular recording medium magnetic transfer / demagnetization method according to the first embodiment of the present invention will now be described with reference to FIGS.
9. FIG. 9 is an explanatory diagram of the configuration of the servo unit mask medium used in Example 1. The upper diagram is a schematic plan view, and the lower diagram is a schematic sectional view of the main part.
The servo unit mask medium 60 is a resist pattern (not shown) by exposing and developing a pattern obtained by inverting the data pattern along the outer contour of the servo data automatically generated from the servo pattern in advance on the transparent glass substrate 61. After forming a groove 63 having a depth of several hundreds of nanometers to form a mask pattern 62 using this resist pattern, a high permeability magnetic film, for example, a CoFe film 64 is deposited by sputtering. The unnecessary portion is removed by lift-off, and the CoFe film 64 is embedded in the groove 63.
In this case as well, margin areas 66 of 10% or less of the width of the mask area 65 are provided on both sides of the mask area 65 as necessary.

Next, a perpendicular recording medium magnetic transfer / demagnetization process using the above-described servo recording mask medium and servo section mask medium will be described.
First, in exactly the same manner as in Reference Example 1 described above, an electromagnet for applying a perpendicular magnetic field to the surface of the perpendicular magnetic recording medium 40 is provided on the perpendicular magnetic recording medium 40 fixed to the spindle motor 31 so as to be perpendicular. initialize the magnetic recording layer 41 in the vertical direction by applying a magnetic field of more than twice the coercivity H _c of the magnetic recording layer 41 of the magnetic recording medium 40.

Next, after the magnetic recording layer 41 is brought into close contact with the initialization surface of the above-described servo recording mask medium on which the CoFe film is provided, the current flowing in the electromagnet is reversed to reverse the magnetic field in the direction opposite to the initialization direction. Is applied to transfer the servo pattern to the magnetic recording layer 41 to form the servo pattern writing area 42.
In this case, the magnetic field strength is set to be the same as the coercive force Hc of the magnetic recording layer 41, for example.

Next, the mask pattern 62 provided on the servo unit mask medium 60 is positioned and brought into close contact with the servo pattern writing area 42 of the magnetic recording layer 41 so as to completely cover the servo pattern writing area 42. After that, a magnetic field is applied in the horizontal direction of the medium surface using the electromagnet 34 while rotating the perpendicular magnetic recording medium at a low speed, and the magnetic field of the data portion 43 is in a random state close to AC erase by irradiating the laser beam 35. To demagnetize.

The alignment in this case is performed by providing alignment marks on both the magnetic recording layer 41 and the servo unit mask medium 20 and optically confirming the alignment.
Further, the magnetic field strength in this case is, for example, with a 1 to 2 times the coercive force H _c of the magnetic recording layer 41 is irradiated with 85 mJ / cm ² or more laser power using a pulsed laser.

In this demagnetization process, the servo pattern writing area 42 which is light-shielding and covered with the mask pattern 62 made of a magnetic film is shielded from the laser beam 35 and is also shielded magnetically. The servo pattern is retained as it is.
On the other hand, since the laser beam 35 is applied to the data portion 43 where the light shielding portion and the magnetic shield portion do not exist and a horizontal magnetic field is applied, the medium magnetization state close to AC erase can be achieved in a shorter demagnetization process. Become.

Next, a magnetic disk device according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 11 is a conceptual plan view of the magnetic disk apparatus according to the second embodiment of the present invention. A servo pattern is formed by the perpendicular recording medium magnetic transfer / demagnetization method according to any of the first to third embodiments. The transferred perpendicular magnetic recording medium 40 is attached to the rotation shaft of the spindle motor 71 and is fixed by the disc clamp ring 72.

  A slider 75 having a magnetic sensor is attached to the tip of the head arm 73 via a suspension 74 and performs a seeking operation in the radial direction of the perpendicular magnetic recording medium 40.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations and conditions described in the embodiments, and various modifications are possible. For example, in each embodiment, a mask is used. Although a margin area is provided in the pattern, it is not always necessary if alignment is performed with high accuracy.

  In each of the above embodiments, the initialization process is performed in order to clarify the contrast of the servo pattern, but this initialization process is not necessarily required.

Further, Oite in Example 1 above, although the mask pattern is formed by burying a magnetic film, in the same manner as in Reference Example 2, it may be one deposited on a substrate using a lift-off.

In the first embodiment, the magnetic field application and the laser irradiation are performed at the same time. However, the magnetic field application is not necessarily performed at the same time. The laser irradiation may be performed after the magnetic field is applied first, or after the laser irradiation. A magnetic field may be applied.

It is explanatory drawing of the fundamental structure of this invention. FIG. 5 is a diagram illustrating a configuration of a servo recording mask medium. FIG. 5 is a configuration explanatory diagram of a servo unit mask medium according to Reference Example 1 of the present invention. It is explanatory drawing of the perpendicular recording medium magnetic transfer / demagnetization process to the middle of the reference example 1 of this invention. FIG. 5 is an explanatory diagram of a perpendicular recording medium magnetic transfer / demagnetization process up to the middle of FIG. 4 and subsequent steps in Reference Example 1 of the present invention. FIG. 6 is an explanatory diagram of a perpendicular recording medium magnetic transfer / demagnetization process in FIG. 5 and subsequent drawings of Reference Example 1 of the present invention. It is a structure explanatory drawing of the servo part mask medium of the reference example 2 of this invention . It is explanatory drawing of the perpendicular recording medium magnetic transfer / demagnetization process of the reference example 2 of this invention. FIG. 3 is a configuration explanatory diagram of a servo unit mask medium according to the first embodiment of the present invention . It is explanatory drawing of the perpendicular recording medium magnetic transfer / demagnetization process of Example 1 of this invention. FIG. 5 is a conceptual plan view of a magnetic disk device according to a second embodiment of the present invention.

DESCRIPTION OF SYMBOLS 1 Vertical recording medium 2 Servo pattern transfer part 3 Demagnetizing mask medium 4 Base material 5 Mask part 10 Servo recording mask medium 11 Silicon substrate 12 Servo pattern 13 Groove 14 CoFe film 15 Servo data pattern 20 Servo part mask medium 21 Silicon substrate 22 mask pattern 23 groove 24 CoFe film 25 mask area 26 margin area 31 spindle motor 32 electromagnet 33 electromagnet 34 electromagnet 35 laser beam 40 perpendicular magnetic recording medium 41 magnetic recording layer 42 servo pattern writing area 43 data section 50 servo section mask medium 51 Transparent glass substrate 52 Mask pattern 53 Mask region 54 Margin region 60 Servo part mask medium 61 Transparent glass substrate 62 Mask pattern 63 Groove 64 CoFe film 65 Mask region 66 Margin region 71 Spindle motor 72 Disc clamp ring 73 Head arm 74 Suspension 75 Slider

Claims (2)

The base material is made of a transparent member that is transparent to the laser beam used for demagnetization, and the mask portion that completely covers the servo pattern transfer portion of the perpendicular recording medium is made of a magnetic film, and user data of the perpendicular recording medium A demagnetizing mask medium characterized in that no magnetic film is present on the portion. After transferring the servo pattern in the medium surface vertical direction of the perpendicular recording medium by applying a magnetic field in the medium surface vertical direction in a state of being in close contact with the perpendicular recording medium, using a mask medium in which servo information is patterned in advance, The medium of the perpendicular recording medium in the horizontal direction in a state where the demagnetization mask medium according to claim 1 is used and the mask part of the demagnetization mask medium and the servo pattern transfer part are aligned and brought into close contact with each other. And applying a magnetic field to the medium and irradiating a laser beam perpendicularly to the medium surface from the demagnetization mask medium side to demagnetize the vertical vertical magnetization in the user data portion of the perpendicular recording medium. Transfer / demagnetization method.

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