JP2006048765A - Magnetic disk and magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact magnetic disk wherein a use environment has high heat dissipation even at a high temperature, and thermal fluctuation of recording, head clashing, or the like is difficult to occur. <P>SOLUTION: The magnetic disk having a diameter of 1.8 inches or less is provided with a first concentric-circular or a helical groove formed on a surface covered with the lubricant layer of a magnetic recording layer to pass an air flow through both sides of each recording track. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic disk and a magnetic disk device.

In recent years, portable electronic devices have been increasingly reduced in size and functionality. For this reason, a storage device mounted on a portable electronic device is required to be reduced in size and capacity, and a magnetic disk device has been studied as one of such storage devices.

  In a small magnetic disk device, for example, a small magnetic disk having a diameter of 1.8 inches or less is used.

  However, it is known that the power consumption per unit recording capacity of a small magnetic disk increases when it is smaller than 2.5 inches. As a result, the amount of heat generated per unit capacity increases, and thermal fluctuations in recording, head crashes, and the like are likely to occur. This accelerates as the use environment gets hotter. However, since a small magnetic disk device is used for in-vehicle use or mobile use, the use environment temperature is often high. For this reason, it is desirable to improve the heat dissipation in the small magnetic disk device.

A conventional magnetic disk device having a normal size includes, for example, a device in which a groove is provided in a hollow wall that partially surrounds the disk in the device to form an air flow path (see, for example, Patent Document 1).
Japanese Patent Application No. 2002-230750

  An object of the present invention is to provide a small magnetic disk and a magnetic disk that are excellent in heat dissipation even in a high usage environment, and are less susceptible to thermal fluctuations of recording and head crashes.

The present invention, first, is a magnetic disk having a disk diameter of 1.8 inches or less,
A substrate,
A deposited layer disposed on the substrate and including a magnetic recording layer;
Comprising a lubricating layer covering the deposited layer,
There is provided a magnetic disk characterized in that the surface of the deposited layer covered with the lubricating layer has concentric or spiral first grooves that allow airflow to pass on both sides of each recording track.

Secondly, the present invention includes a substrate, a deposited layer disposed on the substrate and including a magnetic recording layer, and a lubricating layer covering the deposited layer, and is covered with the lubricating layer of the deposited layer On the surface, a magnetic disk having concentric or spiral first grooves that allow airflow to pass on both sides of each recording track;
A magnetic head arranged to face the lubricating layer;
There is provided a magnetic disk device comprising a drive mechanism for rotating the magnetic disk in a direction along the recording track with respect to the magnetic head.

  The present invention provides a small magnetic disk and a magnetic disk that are excellent in heat dissipation even in a high temperature environment and are less susceptible to thermal fluctuations of recording and head crashes.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same referential mark is attached | subjected to the component which exhibits the same or similar function, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a plan view schematically showing a magnetic disk according to the first embodiment of the present invention. FIG. 2 is an enlarged plan view showing a part of the magnetic disk of FIG. FIG. 3 is a sectional view taken along line III-III of the magnetic disk of FIG. In the figure, a double-headed arrow D1 indicates a first direction that is a track direction, and a double-headed arrow D2 is a second direction that intersects the first direction D1 (here, a direction perpendicular to the first direction D1, that is, a radius Direction).

  The magnetic disk 10 includes a substrate 1 as shown in FIG. A deposited layer 2 is formed on the substrate 1. The deposited layer 2 is covered with a lubricating layer 3 made of a lubricant.

  The deposited layer 2 includes a magnetic recording layer 22. Here, as an example, a stacked body of a base layer 21, a magnetic recording layer 22, and a protective layer 23 is formed as the deposition layer 2.

  As shown in FIGS. 1 and 2, the magnetic disk 10 has a structure in which a data area Ad and a servo area As are provided on one main surface of the substrate 1.

  As shown in FIGS. 2 and 3, the portion corresponding to the data area Ad of the deposited layer 2 includes a plurality of recording tracks TR and a plurality of first groove portions G1. In FIG. 1, only those located on the innermost and outermost circumferences of the first groove part G1 are illustrated, and those located between the first groove parts G1 are omitted. The recording track TR and the first groove G1 are formed in a spiral shape or a concentric shape. Further, the recording track TR and the first groove portion G1 are formed such that one first groove portion G1 and one or a plurality of recording tracks TR are alternately arranged in the second direction D2.

  2 and 3, as an example, the recording track TR and the first groove portion G1 are formed so that one first groove portion G1 and one recording track TR are alternately arranged in the second direction D2. . Here, as an example, the magnetic recording layer 22 is patterned to form the first groove part G1 having grooves having an opening width B and arranged at the groove interval C. Furthermore, here, as an example, the first groove part G1 other than the innermost and outermost first groove part G1 is formed only in the data area Ad and not in the servo area As.

  The servo area As is adjacent to the data area Ad in the first direction D1. The servo area As includes, for example, an AGC (Automatic Gain Control) part P1, an address part P2, a pad part P3, a burst part P4, and a pad part P5. In the example shown in FIG. 2, the magnetic disk 10 is moved in the left direction relative to the magnetic head (not shown) at the time of writing and reading information. Therefore, the AGC part P1, the address part P2, the pad part P3, the burst part P4, and the pad part P5 are sequentially arranged from the left side to the right side in the drawing.

  The AGC part P1 outputs a signal that can be used as a reference for amplifying signals from the address part P2, the burst part P4, the recording track TR, etc. to an appropriate magnitude, for example, a high level signal. The AGC unit P1 is continuous in the second direction D2, and is configured to output a signal having a constant intensity even when the magnetic head is moved in the second direction D2. The AGC unit P1 is not necessarily provided. However, when the AGC unit P1 is provided, when the signals from the address unit P2, the burst unit P4, the recording track TR, and the like are amplified, the magnetic field depends on the signal strength from the AGC unit P1. The gain of the disk device can be changed. Therefore, writing and reading of information can be performed with higher accuracy.

  The address part P2 holds address information corresponding to each recording track TR. Each portion corresponding to each recording track TR of the address portion P2 includes, for example, a first signal level portion PH that outputs a high level signal and a second signal level portion PL that outputs a low level signal in a first direction. It has a structure arranged along D1, and the arrangement pattern of the first signal level part PH and the second signal level part PL is determined corresponding to the address information. Further, in the address part P2, the first signal level part PH and the second signal level part PL adjacent in the second direction D2 have a boundary between the adjacent recording tracks TR and along the first direction D1. .

  The pad portion P3 is not necessarily provided, but the provision of the pad portion P3 is advantageous in separating the signal from the address portion P2 and the signal from the burst portion P4. Similarly, the pad portion P5 is not necessarily provided. However, when the pad portion P5 is provided, it is advantageous in separating the signal from the burst portion P4 and the signal from the recording track TR.

  The burst part P4 gives information on the relative position between the magnetic head and the selected recording track TR in the second direction D2. The burst part P4 includes, for example, first to fourth regions P41 to P44 arranged in the first direction D1. In each of the first to fourth regions P41 to P44, for example, the first signal level unit PH that outputs a high level signal and the second signal level unit PL that outputs a low level signal are in the second direction. Arranged at D2.

  For example, a layer structure similar to that of the recording track TR can be employed for the first signal level portion PH. For example, the second signal level portion PL may have the same layer structure as that of the recording track TR, or may have the same layer structure as that of the first groove portion G1. Alternatively, the same layer structure as that of the recording track TR may be adopted for a part of the second signal level part PL, and the same layer structure as that of the first groove part G1 may be adopted for another part of the second signal level part PL. Good.

  When the same layer structure as that of the recording track TR is adopted for the first signal level portion PH and the second signal level portion PL, for example, the magnetization of the magnetic recording layer 22 by the first signal level portion PH and the second signal level portion PL. These signal levels can be made different by differentiating the directions. Further, when the same layer structure as that of the recording track TR is adopted for the first signal level portion PH and the same layer structure as that of the first groove portion G1 is adopted for the second signal level portion PL, after the magnetic recording layer 22 is formed. There is no need to record various information in the servo area As.

  The magnetic disk of the present invention has a disk diameter of 1.8 inches or less. On the other hand, if the diameter of the magnetic disk is smaller than 0.1 inch, manufacture becomes difficult. Therefore, in the present invention, a disk having a diameter of 0.1 inch or more is preferable.

  In the magnetic disk 10 according to this aspect, the first groove portion G1 has a function of contacting the airflow by rotating the disk and transferring the heat of the disk to the airflow. LSIs and motors are heat sources, but their heat is also transferred to the airflow through the disk. The air flow passes heat to the housing portion of the magnetic disk device and contributes to heat dissipation. Concentric or spiral grooves can efficiently cool the recording track portion by rotating the disk.

  When the distance C (groove interval) between the first groove portions D1 adjacent to each other in the second direction D2 is larger than 300 nm, the above effect does not appear remarkably. On the other hand, if it is smaller than 5 nm, the recording track width becomes small, and it becomes easy to be affected by thermal expansion and the like, and the head tracking becomes difficult. Preferably, the groove interval is 200 nm or less and 30 nm or more.

  The depth of the first groove part G1 is in the range of not less than 0.5 nm and not more than 50 nm. If it is shallower than 0.5 nm, the heat dissipation effect on the airflow is almost the same as that of the flat plate. On the other hand, if it is deeper than 50 nm, the HDI becomes unstable and the head crashes easily. Preferably they are 1 nm or more and 30 nm or less.

  The width B of the opening of the first groove part G1 is in the range of 2 nm to 200 nm. When it is narrower than 2 nm, the heat dissipation effect on the airflow is almost the same as that of the flat plate. On the other hand, if it is larger than 200 nm, the HDI becomes unstable and head crashes easily. Preferably they are 5 nm or more and 100 nm or less.

  Further, it is preferable that the width of the opening of the first groove G1 is wider than that of the bottom. Thereby, the flow of airflow becomes smoother and cooling efficiency increases.

  Next, materials that can be used for the magnetic disk 10 will be described.

  As the substrate 1, for example, a glass substrate, an Al-based alloy substrate, a ceramic substrate, a carbon substrate, a Si single crystal substrate having an oxidized surface, and a substrate in which a NiP layer is formed on the surface of these substrates can be used. Amorphous glass or crystallized glass can be used for the glass substrate. Examples of the amorphous glass include soda lime glass and aluminosilicate glass. Examples of crystallized glass include lithium-based crystallized glass. As the ceramic substrate, for example, a sintered body mainly composed of aluminum oxide, aluminum nitride, silicon nitride, or the like, or a fiber reinforced one of these sintered bodies can be used. In order to form the NiP layer on the surface of the substrate, for example, plating or sputtering can be used. The diameter of the substrate 1 is, for example, 1 inch (2.54 cm).

  The deposited layer 2 includes a magnetic recording layer 22. Typically, the deposited layer 2 further includes an underlayer 21 and a protective layer 23.

  The underlayer 21 can include a soft magnetic layer. For example, when the magnetic recording layer 22 is a perpendicular magnetic recording layer, the soft magnetic layer allows a recording magnetic field from the write magnetic pole to pass through the magnetic recording layer 22 and records it to a return yoke disposed in the vicinity of the write magnetic pole. It plays the role of refluxing the magnetic field. That is, the soft magnetic layer plays a part of the function of the recording head and plays a role of improving the recording efficiency by applying a steep vertical magnetic field to the magnetic recording layer 22.

  For this soft magnetic layer, for example, a high magnetic permeability material containing at least one of Fe, Ni, and Co is used. Examples of such materials include FeCo alloys such as FeCo and FeCoV, FeNi alloys such as FeNi, FeNiMo, FeNiCr, and FeNiSi, FeAl alloys such as FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu, and FeAlO, and FeSi alloys, FeTa FeTa alloys such as FeTaC and FeTaN, and FeZr alloys such as FeZrN.

  For the soft magnetic layer, a material having a microcrystalline structure such as FeAlO, FeMgO, FeTaN, FeZrN or the like containing 60 atomic% or more of Fe or a granular structure in which fine crystal particles are dispersed in a matrix can be used.

  As another material of the soft magnetic layer, a Co alloy containing Co and at least one of Zr, Hf, Nb, Ta, Ti, and Y can be used. The Co content in the soft magnetic layer is, for example, 80 atomic% or more. When such a Co alloy is formed by sputtering, an amorphous layer is easily formed. Amorphous soft magnetic materials do not have magnetocrystalline anisotropy, crystal defects, and grain boundaries, and thus exhibit very excellent soft magnetism. Further, by using an amorphous soft magnetic material, it is possible to reduce the noise of the medium. Examples of the amorphous soft magnetic material include CoZr, CoZrNb, and CoZrTa alloys.

  The underlayer 21 can further include another layer between the soft magnetic layer and the substrate 1 in order to improve the crystallinity of the soft magnetic layer or improve the adhesion between the soft magnetic layer and the substrate 1. For such a layer, for example, Ti, Ta, W, Cr, Pt, alloys containing these, oxides thereof, nitrides thereof, and the like can be used.

  The underlayer 21 can further include a nonmagnetic layer between the soft magnetic layer and the magnetic recording layer 22. The role of this nonmagnetic layer is to block the exchange coupling interaction between the soft magnetic layer and the magnetic recording layer 22 and to control the crystallinity of the magnetic recording layer 22. Examples of the material for the nonmagnetic layer include Ru, Pt, Pd, W, Ti, Ta, Cr, Si, alloys containing these, oxides thereof, and nitrides thereof.

  A plurality of soft magnetic layers are provided to prevent spike noise, and an Ru layer having a thickness of, for example, about 0.5 nm to 1.5 nm is interposed between the soft magnetic layers so that the soft magnetic layers are antiferromagnetically coupled to each other. May be. Furthermore, the soft magnetic layer may be exchange-coupled with a hard magnetic film having in-plane anisotropy such as CoCrPt, SmCo, or FePt or a pinning layer made of an antiferromagnetic material such as IrMn or PtMn. In this case, in order to control the exchange coupling force, a magnetic layer such as a Co layer or a nonmagnetic layer such as a Pt layer may be disposed above and below the Ru layer.

  When the magnetic recording layer 22 is a perpendicular magnetic recording layer, for example, a material containing Co as a main component and further containing Pt and an oxide can be used. This material can further contain Cr. Examples of the oxide contained in this material include silicon oxide and titanium oxide.

  In the magnetic recording layer 22, the magnetic crystal grains may form a columnar structure. In the magnetic recording layer 22 having such a structure, the orientation and crystallinity of the magnetic crystal grains are good. Therefore, according to such a magnetic recording layer 22, a signal / noise ratio (S / N ratio) suitable for high-density recording can be obtained.

  In obtaining the above structure, the amount of oxide is important. The oxide content may be, for example, in the range of 3 mol% to 12 mol% or in the range of 5 mol% to 10 mol% with respect to the total amount of Co, Pt, and Cr. If the oxide content in the magnetic recording layer 22 is in the above range, the oxide is precipitated around the magnetic particles, and the magnetic particles can be isolated and refined. When the oxide content exceeds the above range, the oxide remains in the magnetic particles, the orientation and crystallinity of the magnetic particles may be impaired, and further oxides may be deposited on the upper and lower sides of the magnetic particles. As a result, a columnar structure in which the magnetic particles penetrate the magnetic recording layer 22 up and down may not be formed. On the other hand, when the oxide content is less than the above range, the magnetic particles may be insufficiently isolated and refined. As a result, noise during recording and reproduction increases, and a signal / noise ratio (S / N ratio) suitable for high-density recording may not be obtained.

  The Pt content of the magnetic recording layer 22 is, for example, in the range of 10 atomic% to 25 atomic%. When the Pt content is within the above range, the uniaxial magnetic anisotropy constant Ku necessary for the perpendicular magnetic recording layer can be obtained, and the crystallinity and orientation of the magnetic particles are improved. As a result, thermal fluctuation characteristics and recording / reproduction characteristics suitable for high-density recording can be obtained. When the Pt content exceeds the above range, a layer having an fcc structure is formed in the magnetic particles, and the crystallinity and orientation may be impaired. On the other hand, if the Pt content is less than the above range, Ku suitable for high-density recording cannot be obtained, and therefore thermal fluctuation characteristics suitable for high-density recording may not be obtained.

  The Cr content of the magnetic recording layer 22 may be, for example, in the range of 0 atomic% to 16 atomic%, or may be in the range of 10 atomic% to 14 atomic%. When the Cr content is within the above range, high magnetization can be maintained without lowering the uniaxial magnetic anisotropy constant Ku of the magnetic particles. As a result, recording / reproduction characteristics suitable for high density recording and sufficient thermal fluctuation characteristics can be obtained. If the Cr content exceeds the above range, the Ku of the magnetic particles becomes small, so that the thermal fluctuation characteristics may be deteriorated and the crystallinity and orientation of the magnetic particles may be deteriorated. As a result, the recording / reproducing characteristics may be deteriorated.

  The magnetic recording layer 22 can further include one or more elements selected from B, Ta, Mo, Cu, Nd, W, Nb, Sm, Tb, Ru, and Re. When these elements are added, the miniaturization of the magnetic particles can be promoted, or the crystallinity and orientation of the magnetic particles can be improved. Therefore, recording / reproduction characteristics and thermal fluctuation characteristics suitable for higher density recording can be obtained. The total content of these additive elements is, for example, 8 atomic% or less. When the total content of additive elements exceeds 8 atomic%, phases other than the hcp phase are formed in the magnetic particles, and the crystallinity and orientation of the magnetic particles may be disturbed. As a result, recording / reproducing characteristics and thermal fluctuation characteristics suitable for high-density recording may not be obtained.

  Examples of other materials that can be used for the magnetic recording layer 22 include a CoPt alloy, a CoCr alloy, a CoPtCr alloy, CoPtO, CoPtCrO, CoPtSi, and CoPtCrSi. As the magnetic recording layer 22, a multilayer film of an alloy layer mainly composed of at least one selected from the group consisting of Pt, Pd, Rh, and Ru and a Co layer may be used. Further, as the magnetic recording layer 22, a layer obtained by adding Cr, B or O to at least one layer of these multilayer films can be used. Examples of such a multilayer film include a CoCr / PtCr film, a CoB / PdB film, and a CoO / RhO film.

  The thickness of the magnetic recording layer 22 may be, for example, in the range of 5 nm to 60 nm or in the range of 10 nm to 40 nm. The magnetic recording layer 22 having a thickness within this range is suitable for high recording density. If the magnetic recording layer 22 is thin, the reproduction output tends to be too low and the noise component tends to be higher. On the other hand, if the magnetic recording layer 22 is thick, the reproduction output is too high and the waveform tends to be distorted.

  The coercive force of the magnetic recording layer 22 is, for example, 237000 A / m (3000 Oe) or more. When the coercive force is small, the thermal fluctuation resistance tends to be inferior. Further, the perpendicular squareness ratio of the magnetic recording layer 22 is, for example, 0.8 or more. If the vertical squareness ratio is small, the thermal fluctuation resistance tends to be inferior.

The protective layer 24 serves to prevent corrosion of the magnetic recording layer 22 and prevent damage to the surface of the magnetic head when it contacts the magnetic disk. Examples of the material of the protective layer 24 include a material containing C, SiO ₂ , and ZrO ₂ . The thickness of the protective layer 24 is, for example, in the range of 1 nm to 10 nm. When the thickness of the protective layer 24 is within the above range, the distance between the magnetic head and the magnetic disk can be reduced. This is advantageous from the viewpoint of high density recording.

  Each layer included in the above-described deposition layer 2 can be formed by a method such as sputtering, vacuum evaporation, or electrolytic plating.

  As the material of the lubricating layer 3, for example, a lubricant such as perfluoropolyether, fluorinated alcohol, and fluorinated carboxylic acid can be used. The lubricating layer 3 can be formed, for example, by applying a lubricant to the protective layer 23.

  Next, the second aspect of the present invention will be described.

  FIG. 4 is a plan view schematically showing a magnetic disk according to the second aspect of the present invention. The magnetic disk 10 has the same structure as the magnetic disk 10 shown in FIGS. 1 to 3 except that the shapes of the data area Ad and the servo area As are changed and the second groove portion G2 is further provided in the deposited layer 2. have.

  Specifically, in the magnetic disk 10 of FIG. 4, the boundary between the data area Ad and the servo area As is spiral. In FIG. 4, as an example, the boundary between the data area Ad and the servo area As is a left-handed spiral shape.

  In this example, the second groove portion G2 is provided on the boundary between the data area Ad and the servo area As, and has a left-handed spiral shape. The second groove part G2 may be provided in the servo area As.

  In this example, one end of each second groove part G2 is connected to the innermost first groove part G1. Moreover, the other end of each 2nd groove part G2 is connected to the 1st groove part G1 of the outermost periphery in this example. Each second groove G2 may not be connected to the innermost first groove G1 or the outermost first groove G1. Moreover, each 2nd groove part G2 may be divided | segmented into the some part between the 1st groove part G1 of the innermost periphery, and the 1st groove part G1 of the outermost periphery.

  When the magnetic disk 10 is rotated in the clockwise direction in the drawing, the airflow flows well along G2.

  The above effect can also be obtained when the second groove G2 has a right-handed spiral shape and the magnetic disk 10 is rotated counterclockwise.

  Next, a magnetic disk device equipped with the magnetic disk 10 according to the first and second aspects will be described.

FIG. 5 is a perspective view schematically showing an example of a recording disk device on which the magnetic disk 10 according to the first and second aspects can be mounted.
This magnetic disk apparatus includes the magnetic disk 10 according to the first or second aspect, the spindle 20, the pivot 30, the magnetic head assembly 40, the voice coil motor 50, and the like. These are arranged in the housing 60.

  The magnetic disk 10 is rotatably supported by a spindle 20, and a motor (not shown) that operates in response to a control signal from a control circuit included in a control unit (not shown) is connected to the spindle 20. . In the magnetic disk device shown in FIG. 5, the rotation of the magnetic disk 10 can be controlled thereby.

  A pivot 30 is disposed in the vicinity of the outer periphery of the magnetic disk 10, and this pivot 30 supports the magnetic head assembly 40 in a swingable manner via ball bearings (not shown) disposed at two upper and lower portions thereof. ing. A coil (not shown) is wound around the bobbin portion of the magnetic head assembly 40. The coil, a permanent magnet disposed opposite to the coil, and a counter yoke form a magnetic circuit and a voice coil. A motor 50 is configured. The voice coil motor 50 is also connected to the control unit, so that the head slider 401 at the tip of the magnetic head assembly 40 can be positioned on a desired recording track TR of the magnetic disk 10.

  The magnetic head assembly 40 includes, for example, an actuator arm 402 including a bobbin portion that holds a drive coil. One end of a suspension 403 is attached to the actuator arm 402, and a head slider 401 is attached to the other end of the suspension 403. A piezoelectric element for performing minute position control is installed at the tip of the actuator arm 402.

  A magnetic head is incorporated in the head slider 401. This magnetic head is, for example, a composite head, and includes a single magnetic pole structure write head and a read head using a shielded MR element such as a GMR element or a TMR element.

  Lead wires (not shown) for signal writing and reading are formed on the suspension 403, and these lead wires are electrically connected to electrodes of the magnetic head incorporated in the head slider 401, respectively. . In this magnetic disk apparatus, information recording and reproduction are performed in a state where the magnetic disk 10 is rotated and the head slider 401 is floated from the magnetic disk 10 by the airflow generated thereby. In the magnetic disk apparatus shown in FIG. 5, the motor connected to the spindle 20 and the voice coil motor 50 constitute a drive mechanism. A microprocessor for generating a tracking signal based on a signal from the servo area As is installed in the magnetic disk device.

  Although the magnetic disk device using the floating magnetic head has been described above, a contact magnetic head may be used as the magnetic head.

  FIG. 6 is a sectional view schematically showing a part of a magnetic disk apparatus using a contact type magnetic head. In FIG. 6, reference numeral 4010 indicates a head slider body, and reference numeral 4011 indicates a write magnetic pole.

  A head slider 401 shown in FIG. 6 is a contact type head slider. As shown in FIG. 6, when the contact-type head slider 401 is used, heat can be radiated through the head, which is convenient for cooling.

  FIG. 5 shows an example in which the disk is provided on a motor rotating shaft in which only the lower part is fixed. In FIG. 7, a magnetic disk is provided on a motor rotating shaft in which the upper and lower parts are fixed and a motor base 704 is provided in the lower part. A sectional view of a disk device is shown. As shown in the figure, in this example, a rotating shaft 701 for rotating the magnetic disk 10 provided with a bearing 702 and attached to the disk fixing plate 705 by a fixing screw 706 is connected to the vertical direction of the apparatus housing 60 and the physical direction. If the structure is such that heat is dissipated from the upper and lower sides of the device housing 60, the cooling efficiency is further increased.

  Examples of the present invention will be described below.

Example 1
The magnetic disk 10 shown in FIGS. 1 to 3 was produced by the following method.
First, a soft magnetic layer having a thickness of 100 nm and a Pd layer having a thickness of 30 nm were sequentially formed as a base layer 21 on a glass substrate 1 having a diameter of 0.85 inches. Next, a perpendicular magnetic recording layer having a granular structure made of a mixture of CoCrPt and SiO ₂ was formed on the underlayer 21 as the magnetic recording layer 22. The thickness of the magnetic recording layer 22 was 20 nm.

Next, in order to pattern the magnetic recording layer 22, the following steps were performed.
That is, first, an SiO ₂ film having a thickness of 50 nm was formed on the magnetic recording layer 22. A resist film is formed on the SiO ₂ film by spin coating, and a Ni mold (stamper) provided with a convex portion at a position corresponding to the first groove portion G1 and the second signal level portion PL is pressed against the resist film. It was. Thereby, a concave pattern having a shape corresponding to the convex pattern of the Ni mold was formed on the resist film.

  As the Ni mold, one formed using electron beam lithography and plating was used. The height of the convex portion of the Ni mold was 50 nm. In addition, among the convex portions of the Ni mold, the width of each circumferential convex portion corresponding to the first groove portion G1 was 50 nm, and the interval between adjacent circumferential convex portions was 100 nm.

Next, the resist layer and the SiO ₂ film were etched by RIE (Reactive Ion Etching) method. This etching was performed until the surface of the magnetic recording layer 22 was exposed at the position of the recess formed in the resist layer. As a result, an SiO ₂ pattern opened at a position corresponding to the concave pattern of the resist layer was obtained.

Subsequently, the magnetic recording layer 22 was etched at a position corresponding to the opening of the SiO ₂ pattern by Ar ion milling, and this SiO ₂ pattern was also etched. The magnetic recording layer 22 was patterned as described above.

Next, an SiO ₂ film as an embedded layer 23 was formed on the surface of the substrate 1 on the magnetic recording layer 22 side, and then etched back. Next, a diamond-like carbon layer was sequentially formed as the protective layer 24.

  As a result of measurement using an AFM (Atomic Force Microscope), the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 corresponds to the recording track TR of the protective layer 24. It was 3 nm lower than the part that was made.

  Thereafter, the lubricant layer 3 was formed by applying a monomolecular adsorptive lubricant onto the protective layer 24. As described above, the magnetic disk 10 shown in FIGS. 1 to 3 was completed. In the magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 3 nm, and the interval was 110 nm. The width of the surface of the first groove is 40 nm, and the width of the surface is wider than the bottom.

  Next, the magnetic disk 10 was mounted on the magnetic disk apparatus of FIG. 5, and an accelerated life test was performed under the following conditions.

In other words, the head slider 401 used here is one that floats 10 nm from the magnetic disk 10. The dimension of the magnetic detection unit of the read head in the second direction D2 was 100 nm, and the dimension of the write magnetic pole of the write head in the second direction D2 was 120 nm. Under the conditions of a temperature of 60 ° C. and a humidity of 80%, the magnetic disk 10 was continuously driven by rotating at 3600 rpm. As a result, the bit error rate became 10 ⁻⁵ or more after about 500 hours from the start of the test.

(Example 2)
A magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in Example 1 except that the glass substrate 1 having a diameter of 1 inch was used. As a result of measurement by AFM, the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 is 3 nm from the portion corresponding to the recording track TR of the protective layer 24. It was low. Further, in the magnetic disk 10, on the surface covered with the lubricating layer 3, the groove depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 3 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 450 hours from the start of the test.

(Example 3)
First, a soft magnetic layer having a thickness of 100 nm and a Pd layer having a thickness of 30 nm were sequentially formed as a base layer 21 on a glass substrate 1 having a diameter of 0.85 inches. Next, a perpendicular magnetic recording layer having a granular structure made of a mixture of CoCrPt and SiO ₂ was formed on the underlayer 21 as the magnetic recording layer 22. The thickness of the magnetic recording layer 22 was 20 nm.

Next, in order to pattern the magnetic recording layer 22, the following steps were performed.
That is, first, a 70 nm thick SiO ₂ film was formed on the magnetic recording layer 22. A resist film is formed on the SiO ₂ film by spin coating, and a Ni mold (stamper) provided with a convex portion at a position corresponding to the first groove portion G1 and the second signal level portion PL is pressed against the resist film. It was. Thereby, a concave pattern having a shape corresponding to the convex pattern of the Ni mold was formed on the resist film.

  As the Ni mold, one formed using electron beam lithography and plating was used. The height of the convex portion of the Ni mold was 50 nm. Further, among the convex portions of the Ni mold, the width of each ring-shaped convex portion corresponding to the first groove portion G1 was 50 nm, and the interval between adjacent circumferential convex portions was 100 nm.

Next, the resist layer and the SiO ₂ film were etched by RIE (Reactive Ion Etching) method. This etching was performed until the surface of the magnetic recording layer 22 was exposed at the position of the recess formed in the resist layer. As a result, an SiO ₂ pattern opened at a position corresponding to the concave pattern of the resist layer was obtained.

Subsequently, the magnetic recording layer 22 was etched at a position corresponding to the opening of the SiO ₂ pattern by Ar ion milling, and this SiO ₂ pattern was also etched. The magnetic recording layer 22 was patterned as described above.

  Next, a diamond-like carbon layer was sequentially formed as a protective layer 24 on the surface of the substrate 1 on the magnetic recording layer 22 side.

  As a result of measurement using an AFM (Atomic Force Microscope), the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 corresponds to the recording track TR of the protective layer 24. It was 30 nm lower than the part that was made.

  Thereafter, the lubricant layer 3 was formed by applying a monomolecular adsorptive lubricant onto the protective layer 24. The magnetic disk 10 was completed as described above. In this magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion that allows air current to flow on both sides of each recording track was 30 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 550 hours from the start of the test.

Example 4
The magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in the first embodiment. In this example, the radius of the innermost recording track TR was set to 4.7 mm as in the first embodiment. Further, as a result of measurement by AFM, the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 is changed by changing the etching back condition from that in the first embodiment. The protective layer 24 was 10 nm lower than the portion corresponding to the recording track TR. Further, in the magnetic disk 10, on the surface covered with the lubricating layer 3, the groove depth of the concentric first groove portion through which airflow passes on both sides of each recording track was 10 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 600 hours from the start of the test.

(Example 5)
A magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in Example 1 except that the glass substrate 1 having a diameter of 1.8 inches was used. As a result of measurement by AFM, the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 is 3 nm from the portion corresponding to the recording track TR of the protective layer 24. It was low. Further, in the magnetic disk 10, on the surface covered with the lubricating layer 3, the groove depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 3 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 500 hours from the start of the test.

(Example 6)
A magnetic disk 10 was prepared by the same method as described in Example 1 except that a Ni master having a spiral groove pattern was used instead of using a Ni master having a circumferential groove pattern. As a result of measurement by AFM, the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 is 3 nm from the portion corresponding to the recording track TR of the protective layer 24. It was low. Further, in the magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the spiral first groove portion through which airflow passes on both sides of each recording track was 3 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 500 hours from the start of the test.

(Comparative Example 1)
A magnetic disk was manufactured by the same method as described in Example 1 except that the magnetic recording layer 22 was not patterned. In this example, various information in the servo area is written using a servo writer.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 150 hours from the start of the test.

(Comparative Example 2)
A magnetic disk was manufactured by the same method as described in Example 2 except that the magnetic recording layer 22 was not patterned. In this example, various information in the servo area is written using a servo writer.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 1700 hours from the start of the test.

(Comparative Example 3)
A magnetic disk was manufactured by the same method as described in Example 5 except that the magnetic recording layer 22 was not patterned. In this example, various information in the servo area is written using a servo writer.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 300 hours from the start of the test.

(Comparative Example 4)
A magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in Example 1 except that the glass substrate 1 having a diameter of 2.0 inches was used. As a result of measurement by AFM, the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 is 3 nm from the portion corresponding to the recording track TR of the protective layer 24. It was low. Further, in the magnetic disk 10, on the surface covered with the lubricating layer 3, the groove depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 3 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 500 hours from the start of the test.

(Comparative Example 5)
A magnetic disk was fabricated by the same method as described in Comparative Example 4 except that the magnetic recording layer 22 was not patterned. In this example, various information in the servo area is written using a servo writer.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 480 hours from the start of the test.

  From the results of Examples 1 and 6 and Comparative Examples 1 to 5, in a disk having a diameter of 1.8 inches or less, a deposited layer disposed on a substrate and including a magnetic recording layer, and a lubricating layer covering the deposited layer The surface of the deposited layer covered with the lubricating layer has concentric or spiral first grooves that allow air current to flow on both sides of each recording track, compared with a magnetic disk without the grooves. As a result, it was found that the life of the disk device at high temperature was excellent.

(Example 7)
The magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in the first embodiment. As a result of measurement by AFM, the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 is 3 nm from the portion corresponding to the recording track TR of the protective layer 24. It was low. Further, in the magnetic disk 10, on the surface covered with the lubricating layer 3, the groove depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 3 nm, and the interval was 110 nm.

Except that this magnetic disk 10 was used and a contact type slider head was used as the slider head 401, an accelerated life test similar to that described in Example 1 was performed. As a result, the bit error rate became 10 ⁻⁵ or more after about 550 hours from the start of the test.

(Example 8)
A magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in Example 1 except that the following Ni mold was used. That is, in this example, the height of the convex portion of the Ni mold was set to 50 nm as in Example 1. In this example, among the convex portions of the Ni mold, the width of each ring-shaped convex portion corresponding to the first groove portion G1 was set to 50 nm as in the first embodiment. However, in this example, among the convex portions of the Ni mold, the interval between the ring-shaped convex portions corresponding to the first groove portion G1 was 280 nm.

The produced recording track TR had a width of 290 nm, the bottom of the first groove G1 was 30 nm, and the bottom of the first groove G1 was 4 nm lower than the portion of the protective layer 24 corresponding to the recording track TR.

  Thereafter, the lubricant layer 3 was formed by applying a monomolecular adsorptive lubricant onto the protective layer 24. As described above, the magnetic disk 10 shown in FIGS. 1 to 3 was completed. In this magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 4 nm, and the interval was 290 nm.

  Next, the magnetic disk 10 was mounted on the magnetic disk apparatus of FIG. 5, and an accelerated life test was performed under the following conditions.

In other words, the head slider 401 used here is one that floats 10 nm from the magnetic disk 10. The dimension of the magnetic detection unit of the read head in the second direction D2 was 290 nm, and the dimension of the write magnetic pole of the write head in the second direction D2 was 300 nm. As a result, the bit error rate became 10 ⁻⁵ or more after about 480 hours from the start of the test.

Example 9
A magnetic disk 10 shown in FIGS. 1 to 3 was produced by the same method as described in Example 1 except that the following Ni mold was used. That is, in this example, the height of the convex portion of the Ni mold was set to 50 nm as in Example 1. In this example, among the convex portions of the Ni mold, the width of each ring-shaped convex portion corresponding to the first groove portion G1 was set to 50 nm as in the first embodiment. However, in this example, among the convex portions of the Ni mold, the interval between the ring-shaped convex portions corresponding to the first groove portion G1 was set to 320 nm.

The produced recording track TR had a width of 330 nm, the bottom of the first groove G1 was 30 nm, and the bottom of the first groove G1 was 4 nm lower than the portion of the protective layer 24 corresponding to the recording track TR.

  Thereafter, the lubricant layer 3 was formed by applying a monomolecular adsorptive lubricant onto the protective layer 24. As described above, the magnetic disk 10 shown in FIGS. 1 to 3 was completed. In the magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 4 nm, and the interval was 330 nm.

  Next, the magnetic disk 10 was mounted on the magnetic disk apparatus of FIG. 5, and an accelerated life test was performed under the following conditions.

In other words, the head slider 401 used here is one that floats 10 nm from the magnetic disk 10. The dimension of the magnetic detection unit of the read head in the second direction D2 was 320 nm, and the dimension of the write magnetic pole of the write head in the second direction D2 was 340 nm. As a result, the bit error rate became 10 ⁻⁵ or more after about 400 hours from the start of the test.

(Example 10)
A magnetic disk 10 shown in FIG. 4 was produced by the same method as described in Example 1 except that the following Ni mold was used.

  That is, in this example, the boundary between the portion corresponding to the data area Ad of the Ni mold and the portion corresponding to the servo area As is spiral. The height of the convex portion of the Ni mold was 50 nm. Of the convex portions of the Ni mold, the width of each ring-shaped convex portion corresponding to the first groove G1 was 50 nm, and the interval between adjacent ring-shaped convex portions was 100 nm. Moreover, the convex part corresponding to the 2nd groove part G2 was made into the right-handed spiral shape, and the width | variety was 50 nm.

In the manufactured magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 3 nm, and the interval was 110 nm. The depth of the right-hand spiral second groove G2 was 3 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk was used. At that time, the disk was rotated to the left. As a result, the bit error rate became 10 ⁻⁵ or more after about 600 hours from the start of the test.

(Example 11)
An accelerated life test was performed in the same manner as in Example 11 except that the disc was rotated to the right instead of rotating to the left. As a result, the bit error rate became 10 ⁻⁵ or more after about 500 hours from the start of the test.

  From the results of Examples 1, 10, and 11, when the second groove portion G2 is provided and the magnetic disk 10 is rotated in a predetermined direction, the life of the disk device at a high temperature is higher than when the second groove portion G2 is not provided. It was found to be excellent.

(Example 12)
As shown in the cross-sectional view of FIG. 7, the rotating shaft for rotating the magnetic disk is physically in contact with the vertical direction of the apparatus housing so that heat is generated from the upper and lower sides of the apparatus casing. It is structured to dissipate heat.

When an acceleration test similar to that of Example 1 was performed, the bit error rate became 10 ⁻⁵ or more after about 650 hours from the start of the test, and the life of the disk device at a high temperature compared to contact with only one side of the housing was increased. I found it excellent.

(Example 13)
The bottom of the first groove G1 is changed by 0.5 nm lower than the portion corresponding to the recording track TR of the protective layer 24 by changing the etch back conditions. Further, in the magnetic disk 10, the surface covered with the lubricating layer 3 Then, the magnetic disk 10 was manufactured in the same manner as in Example 2 except that the depth of the concentric first groove portion through which the air flow was passed on both sides of each recording track was 0.5 nm. An accelerated life test similar to that described in Example 2 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 300 hours from the start of the test.

(Example 14)
By changing the etch back conditions, the bottom of the first groove G1 is made 0.3 nm lower than the portion corresponding to the recording track TR of the protective layer 24. Further, in this magnetic disk 10, the surface covered with the lubricating layer 3 Then, the magnetic disk 10 was manufactured in the same manner as in Example 2 except that the groove depth of the concentric first groove portion through which airflow was passed on both sides of each recording track was 0.3 nm. An accelerated life test similar to that described in Example 2 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 220 hours from the start of the test.

(Example 15)
The magnetic disk 10 was fabricated in the same manner as in Example 1 except that the etch back conditions were changed and the width of the bottom and the surface of the first groove G1 were made the same. An accelerated life test similar to that described in Example 2 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 400 hours from the start of the test. By comparison with Example 2, it was found that the surface having a wider surface than the bottom is superior in the life of the disk device at a high temperature.

(Example 16)
A soft magnetic layer having a thickness of 100 nm and a Pd layer having a thickness of 30 nm were sequentially formed as a base layer 21 on a glass substrate 1 having a diameter of 0.85 inches. Next, a perpendicular magnetic recording layer having a granular structure made of a mixture of CoCrPt and SiO ₂ was formed on the underlayer 21 as the magnetic recording layer 22. The thickness of the magnetic recording layer 22 was 30 nm.

Next, in order to pattern the magnetic recording layer 22, the following steps were performed.
That is, first, an SiO ₂ film having a thickness of 50 nm was formed on the magnetic recording layer 22. A resist film is formed on the SiO ₂ film by spin coating, and a Ni mold (stamper) provided with a convex portion at a position corresponding to the first groove portion G1 and the second signal level portion PL is pressed against the resist film. It was. Thereby, a concave pattern having a shape corresponding to the convex pattern of the Ni mold was formed on the resist film.

  As the Ni mold, one formed using electron beam lithography and plating was used. The height of the convex portion of the Ni mold was 50 nm. Further, among the convex portions of the Ni mold, the width of each ring-shaped convex portion corresponding to the first groove portion G1 was 50 nm, and the interval between adjacent circumferential convex portions was 100 nm.

Next, the resist layer and the SiO ₂ film were etched by RIE (Reactive Ion Etching) method. This etching was performed until the surface of the magnetic recording layer 22 was exposed at the position of the recess formed in the resist layer. As a result, an SiO ₂ pattern opened at a position corresponding to the concave pattern of the resist layer was obtained.

Subsequently, the magnetic recording layer 22 and a part of the underlayer 21 were etched at a position corresponding to the opening of the SiO ₂ pattern by Ar ion milling, and this SiO ₂ pattern was also etched. As described above, part of the magnetic recording layer 22 and the base layer 21 was patterned.

  Next, a diamond-like carbon layer was sequentially formed as a protective layer 24 on the surface of the substrate 1 on the magnetic recording layer 22 side.

  As a result of measurement using an AFM (Atomic Force Microscope), the width of the recording track TR is 110 nm, the width of the bottom of the first groove G1 is 30 nm, and the bottom of the first groove G1 corresponds to the recording track TR of the protective layer 24. It was 50 nm lower than the part where it was.

  Thereafter, the lubricant layer 3 was formed by applying a monomolecular adsorptive lubricant onto the protective layer 24. The magnetic disk 10 was completed as described above. In the magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion that allows airflow to pass on both sides of each recording track was 50 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 500 hours from the start of the test.

(Example 17)
A magnetic disk was manufactured in the same manner as in Example 15 except that the milling conditions were changed and the bottom of the first groove portion G1 was 55 nm lower than the portion corresponding to the recording track TR of the protective layer 24.

  Thereafter, the lubricant layer 3 was formed by applying a monomolecular adsorptive lubricant onto the protective layer 24. The magnetic disk 10 was completed as described above. In the magnetic disk 10, on the surface covered with the lubricating layer 3, the depth of the concentric first groove portion through which airflow passes on both sides of each recording track was 55 nm, and the interval was 110 nm.

An accelerated life test similar to that described in Example 1 was performed except that this magnetic disk 10 was used. As a result, the bit error rate became 10 ⁻⁵ or more after about 280 hours from the start of the test.

1 is a plan view schematically showing a magnetic disk according to a first aspect of the present invention. FIG. 2 is an enlarged plan view showing a part of the magnetic disk in FIG. 1. FIG. 3 is a sectional view taken along line III-III of the magnetic disk of FIG. 2. The top view which shows schematically the magnetic disc which concerns on the 2nd aspect of this invention. The perspective view which shows roughly an example of the recording disk apparatus which can mount the magnetic disk which concerns on a 1st and 2nd aspect. 1 is a cross-sectional view schematically showing a part of a magnetic disk apparatus using a contact type magnetic head. FIG. 3 is a cross-sectional view schematically showing a part of a magnetic disk device in which a rotating shaft for rotating the magnetic disk physically contacts the vertical direction of the device housing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Deposition layer, 3 ... Lubrication layer, 10 ... Magnetic disk, 20 ... Spindle, 21 ... Underlayer, 22 ... Magnetic recording layer, 23 ... Embedded layer, 24 ... Protective layer, 30 ... Pivot, 40 ... Magnetic head assembly, 50 ... Voice coil motor, 60 ... Case, 401 ... Head slider, 402 ... Actuator arm, 403 ... Suspension, 4010 ... Head slider body, 4011 ... Write magnetic pole, 701 ... Fixed shaft, 702 ... Bearing 703 ... Magnetic fluid seal, 704 ... Motor base, 705 ... Disk fixing plate, 706 ... Fixing screw, Ad ... Data area, As ... Servo area, D1 ... First direction, D2 ... Second direction, G1 ... First groove, G2 ... second groove, P1 ... AGC, P2 ... address, P3 ... pad, P4 ... burst, P5 ... pad, P41 ... first Pass, P42 ... second region, P43 ... third region, P44 ... fourth region, PH ... first signal level portion, PL ... second signal level portion, TR ... recording track.

Claims (11)

A magnetic disk having a disk diameter of 1.8 inches or less,
A substrate,
A deposited layer disposed on the substrate and including a magnetic recording layer;
Comprising a lubricating layer covering the deposited layer,
The magnetic disk according to claim 1, wherein concentric or spiral first grooves that allow air current to flow on both sides of each recording track are provided on the surface of the deposited layer covered with the lubricating layer.   The magnetic disk according to claim 1, wherein an interval between adjacent grooves of the first groove portion is 5 nm or more and 300 nm or less.   3. The magnetic disk according to claim 1, wherein a depth of the groove of the first groove is not less than 0.5 nm and not more than 50 nm.   The magnetic disk according to claim 1, wherein a width of the opening of the groove of the first groove portion is 2 nm or more and 200 nm or less.   The magnetic disk according to claim 1, wherein the width of the opening of the groove of the first groove is wider than the width of the bottom.   6. The magnetic disk according to claim 1, wherein the surface of the deposited layer covered with the lubricating layer is further provided with a second spiral groove that crosses the recording track. A magnetic disk according to any one of claims 1 to 6, and
A magnetic head arranged to face the lubricating layer;
A magnetic disk device comprising: a drive mechanism for rotating the magnetic disk with respect to the magnetic head in a direction along the recording track. The surface of the deposited layer covered with the lubricating layer is further provided with a spiral second groove that crosses the recording track,
The drive mechanism rotates the magnetic disk counterclockwise when the second groove portion is clockwise, and rotates the magnetic disk clockwise when the second groove portion is counterclockwise. The magnetic disk device according to claim 7. 7. The rotating shaft for rotating the magnetic disk according to claim 1 is in physical contact with the vertical direction of the apparatus housing so that heat is dissipated from the top and bottom of the apparatus casing. Magnetic disk unit.   The magnetic disk device according to claim 7, wherein the magnetic head is a floating magnetic head.   The magnetic disk device according to claim 7, wherein the magnetic head is a contact type magnetic head.

Images