CN1550003A - Recording heads using magnetic fields generated locally from high current densities in a thin film wire - Google Patents

Recording heads using magnetic fields generated locally from high current densities in a thin film wire Download PDF

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Publication number
CN1550003A
CN1550003A CNA028168011A CN02816801A CN1550003A CN 1550003 A CN1550003 A CN 1550003A CN A028168011 A CNA028168011 A CN A028168011A CN 02816801 A CN02816801 A CN 02816801A CN 1550003 A CN1550003 A CN 1550003A
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China
Prior art keywords
conductor
magnetic
write head
electric current
magnetic field
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CNA028168011A
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Chinese (zh)
Inventor
T・W・科林顿
T·W·科林顿
塞格勒
M·A·塞格勒
罗特美涅
R·E·罗特美涅
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Seagate Technology LLC
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Seagate Technology LLC
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Publication of CN1550003A publication Critical patent/CN1550003A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/012—Recording on, or reproducing or erasing from, magnetic disks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/1278—Structure or manufacture of heads, e.g. inductive specially adapted for magnetisations perpendicular to the surface of the record carrier
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/17—Construction or disposition of windings
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
    • G11B5/3109—Details
    • G11B5/313—Disposition of layers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/74—Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
    • G11B5/743—Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B13/00—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for
    • G11B13/04—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties
    • G11B13/045—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties combined recording by magnetic and optic means
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B2005/0002—Special dispositions or recording techniques
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B2005/0002—Special dispositions or recording techniques
    • G11B2005/0005—Arrangements, methods or circuits
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B2005/0002—Special dispositions or recording techniques
    • G11B2005/0005—Arrangements, methods or circuits
    • G11B2005/0021—Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G11B5/09—Digital recording

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
  • Magnetic Heads (AREA)

Abstract

A method of recording information bits in a magnetic storage medium (58), the method comprising positioning a first conductor (50) adjacent to a magnetic recording medium (58), the conductor having a width and a length, wherein a distance between the first conductor and the magnetic recording medium is less than or equal to the width and the length, and passing a first current through the conductor of sufficient magnitude to produce a magnetic field in the magnetic medium greater than one Tesla and having a magnetic field gradient in a cross track direction and a down track direction greater than 100 Oe/nm over a bit dimension. Magnetic recording heads (48) and disc drives (10) that record data in accordance with the method are also included.

Description

Use the write head in the local magnetic field that produces of high current density in the film wire
The cross reference of relevant application
The application requires the interests of No. the 60/315th, 467, the U.S. Provisional Application that proposes August 21 calendar year 2001.
Invention field
The present invention relates to the write head that uses with magnetic storage medium, especially, relate to this write head that utilizes single conductor, described single conductor is used to induct and supplies axially or the magnetic write field of perpendicular magnetic recording, and relates to a kind of method of using this write head to come record data.
Background of invention
Generally all know the axial and vertical recording head that uses with magnetic storage medium.Axially write head utilizes the utmost point that writes of a pair of opposition, and at the lower surface place of write head, this tip to the utmost point is approaching mutually.Two utmost points connect by yoke (yoke) at the place, top, and yoke can be made by the Ferrite Material similar to extremely employed material.Make a multi-turn coil be arranged in the vicinity of one of two antipodes.When making electric current pass through coil, the magnetic flux of inducting in yoke has produced and has crossed over the separately magnetic field that writes the gap of two utmost points.A part of magnetic flux of crossing over the gap passes through magnetic storage medium, thereby causes head field to change than the magnetic state in the magnetic storage medium of magnetic medium coercive force larger part.Select sufficiently high medium coercive force, so that only cross the head field in the narrow gap between the utmost point, revise the information bit on the storage medium.
The concentric magnetic track recording information bits that separates by boundary belt in the dish upper edge.The width of magnetic track adds does not have the width of information stores boundary belt therein to define track density.Bit length definition linear density along magnetic track.Total memory capacity directly is proportional to the long-pending of track density and linear density.Believe the recording density that may have axial record is limited in about 50 to 100 megabit/square inches that because than the high record density place, super paramagnetic effect causes the instability of the magnetic in the magnetic storage medium.
Advised overcoming the recording density restriction of axial record with perpendicular recording.The vertical recording head that uses with magnetic storage medium can comprise a pair of magnetic-coupled utmost point, comprises that the magnetic flux that the master with little bottom surface area writes the utmost point and has a big bottom surface area returns the utmost point.Coil with multiturn coiling is positioned at and the main extremely vicinity place that writes, is used for the magnetic field of between this utmost point and soft bottom, inducting.Soft bottom be positioned at magnetic storage medium hard recording layer below, strengthen the amplitude of the field that main pole produces.This also allows to use the storage medium of higher coercivity.Therefore, can in medium, store more stable position.In recording process, the electric current energizing quantity in the coil is given main pole, and main pole produces magnetic field.In soft bottom, produce this image, to strengthen the field strength that produces in the magnetic medium.Form magnetic flux from writing the pole tip end,, and return the utmost point by magnetic flux and return main pole by soft bottom.It is enough far away that main pole is left in the position of returning the utmost point, so that main pole and return the magnetization that edge flux (fringe flux) between the utmost point does not influence magnetic medium.
Position-surface density in magnetic recording continues to increase and is devoted to increase the memory capacity of hard disk drive, magnetic is changed (position) size (magnetic transition (bit) dimensions), and accompany along with the write head critical characteristic shift onto below 100 nanometers.Make a kind of stable of recording medium similarly make great efforts to require on the magnetic the dielectric material of hard (high coercivity) at higher area density place.Traditionally, the saturation magnetization of the magnetic material by increasing the inductive write head, or 4 π M sValue has reached and can be written into hard medium, therefore supports to put on the magnetic field of medium.Though at M for the increase write head sThe effort of investigation of materials aspect obtained some success, but increment rate is not enough to keep the annual growth of disk storage meta area density.Write hardening gradually medium similarly to make great efforts be the coercivity that reduces medium during ablation process partly.Generally, this is by to (by the optics, or more generally, pass through electric magnetization) of medium spot heating to reduce that its coercivity relevant with temperature realizes during the ablation process.Till now, this technology much is subject to the proof of concept nature laboratory demonstration, and is needing many technical raisings aspect magnetic head design and the disk material two.Therefore, for the coercive write head that can overcome magnetic medium a kind of demand is arranged, described magnetic medium has the advantage of manufacturability, is applicable to follow-on and more very follow-on recording technique.
Brief summary of the invention
The invention provides a kind of method of recording information bits in magnetic storage medium, described method comprises the vicinity that first conductor is placed on magnetic recording media, described conductor has width and length, wherein the distance between first conductor and the magnetic recording media is less than or equal to width and length, and make the conductor of first electric current by enough amplitudes in magnetic medium, producing magnetic field, and has on a position size magnetic field gradient on the upper and lower track direction of direction (down track direction) of magnetic track intersecting greater than 100 oersteds/nanometer greater than a tesla (Tesla).Current density in the conductor can be greater than 10 9Ampere/centimetre 2, and the length of conductor can be less than 100 nanometers.Can apply electric current as the one or more pulses of predetermined clock in cycle length.By using additional conductor, the ferromagnetic thin film that is close to and/or yoke and coil can increase magnetic field.First conductor can have the thickness less than distance between conductor and the magnetic recording media.
The present invention also comprises the write head that uses with magnetic storage medium, comprises first conductor with width and length; Be used for first conductor is placed on the device of the vicinity of magnetic recording media, wherein the distance between first conductor and the magnetic recording media is less than or equal to width and length; And a kind of device, be used for making first conductor of first electric current by enough amplitudes to have on a position size magnetic field gradient on the upper and lower track direction of direction of magnetic track greater than 100 oersteds/nanometer to produce greater than the magnetic field of a tesla at magnetic medium and to intersect.Write head may further include second conductor parallel with first conductor; The ferromagnetic layer of contiguous first conductor; A magnetic yoke structure; Be used to reduce the coercive a kind of device of medium; Or the combination of these structures.
Another aspect of the present invention comprises disk drive storage system, comprises shell; Be used for supporting being placed on a kind of device of the magnetic storage medium of shell; And be used for write head is placed on the contiguous a kind of device of described rotatable magnetic storage medium, write head comprises first conductor with width and length, wherein the distance between first conductor and the magnetic recording media is less than or equal to width and length; And a kind of device, be used for making first conductor of first electric current by enough amplitudes to have on a position size magnetic field gradient on the upper and lower track direction of direction of magnetic track greater than 100 oersteds/nanometer to produce greater than the magnetic field of a tesla at magnetic medium and to intersect.Write head may further include second conductor parallel with first conductor; The ferromagnetic layer of contiguous first conductor; A magnetic yoke structure; Be used to reduce the coercive a kind of device of medium; Or the combination of these structures.First conductor can have a thickness less than the distance between conductor and the magnetic recording media.
The invention provides a kind of magnetic recording method and equipment, can produce magnetic field that the order of magnitude is a tesla, have at least 100 oersteds/nanometer field gradient and near and surpass the data rate of a GHz.The local field that the electric current of utilization of the present invention from conductor produces is implemented in and writes data bit in the magnetic recording media.Produce local magnetic field in air-supported the place that is less than or equal to the largest conductor size leaving conductor.
The accompanying drawing summary
Fig. 1 is the diagrammatic representation that can use the disk drive of the write head that constitutes according to the present invention;
Fig. 2 is the skeleton view of the conductor of explanation operation of the present invention;
Fig. 3 is the skeleton view of another conductor of explanation operation of the present invention;
Fig. 4 is the curve map that the live of explanation operation of the present invention flows the Distribution of Magnetic Field of film wire;
Fig. 5 is the timing diagram of explanation operation of the present invention;
Fig. 6 is the diagrammatic representation of the axial write head of formation according to the present invention;
Fig. 7 is the diagrammatic representation of another axial write head of formation according to the present invention;
Fig. 8 is the diagrammatic representation of the write head that constitutes according to the present invention current-carrying conductor that is used for vertically writing;
Fig. 9 is the diagrammatic representation of the write head that constitutes according to the present invention another current-carrying conductor of being used for vertically writing;
Figure 10 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 11 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 12 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 13 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 14 is the diagrammatic representation that is used for the write head that axially writes of formation according to the present invention;
Figure 15 is the diagrammatic representation that is used for another write head that axially writes of formation according to the present invention;
Figure 16 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 17 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 18 is the diagrammatic representation that is used for another write head that axially writes of formation according to the present invention;
Figure 19 is the diagrammatic representation that is used for another write head that axially writes of formation according to the present invention;
Figure 20 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 21 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 22 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 23 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 24 is the diagrammatic representation that is used for another write head that vertically writes of formation according to the present invention;
Figure 25 is the diagrammatic representation that is used for another write head that vertically writes that comprises OAMR (optics assisted magnetic recording) string tie structure of formation according to the present invention;
Figure 26 is the diagrammatic representation that is used for another write head that vertically writes that comprises OAMR string tie structure of formation according to the present invention;
Figure 27 is the diagrammatic representation that is used for another write head that vertically writes that comprises OAMR string tie structure of formation according to the present invention;
Figure 28 is the diagrammatic representation that can be used for further specifying write head of the present invention;
Figure 29 is the curve map that the live of the structure among Figure 28 flows the Distribution of Magnetic Field of film wire;
Figure 30 is another width of cloth curve map that the live of the structure among Figure 28 flows the Distribution of Magnetic Field of film wire;
Figure 31 is the curve map that the live of the structure among Figure 28 flows the Distribution of Magnetic Field of film wire; And
Figure 32 is another width of cloth curve map that the live of the structure among Figure 28 flows the Distribution of Magnetic Field of film wire.
Detailed description of the present invention
With reference to the accompanying drawings, Fig. 1 is the diagrammatic representation that can use according to the present invention the write head that constitutes and disk drive 10 that can the method according to this invention record data.Disk drive 10 includes a certain size and is configured to comprise the shell 12 (remove upper part, can see lower part in this figure) of each parts of disk drive.Disk drive 10 comprises Spindle Motor 14 in the enclosure, is used at least one magnetic storage medium 16 of rotational shell, can constitute magnetic storage medium 16 and be used for axially or perpendicular magnetic recording.Comprise at least one arm 18 in the shell 12, arm 18 has first end 20 that has write head or slider 22, and is installed in second end 24 that can rotate around the axis on the axle by bearing 26.Actuator motor 28 is positioned at second terminal 24 places of arm, be used to arm 18 is pivoted and make write head 22 be positioned at dish 16 desired sector or magnetic track.Adjust actuator motor 28 by not shown at this and many in the art controllers of knowing.
The invention provides a kind of method and apparatus, be used for producing local magnetic field by the high current density of film wire, the magnetic flux density, magnetic field gradient and the data rate that consequently are used for magnetic recording will all be enough.We call an ampere magnetic head to this magnetic recording head, because we can calculate the magnetic field that is produced by the open-and-shut geometric live current wire of using Amp.For example, thickness t (along the z axle) than the little thin lead of its width w (along the x axle) be loaded with electric current I (by current density, J, J=I/tw), (leave in the little distance of the edge of lead or surface ratio w) generation magnetic field, provide its amplitude and be in the place on nearly its surface:
H ≅ μ o I 2 w = μ o J · t 2 - - - ( 1 )
μ wherein 0(=4 π * 10 -7Wb/Am) be permeability of free space.
Fig. 2 is the skeleton view of the conductor 30 of explanation work of the present invention.Electric current I by conductor on the direction of arrow 32 expressions produces magnetic field H near conductor.Conductor has width w and thickness t.In the drawings, vertical direction is designated as the z direction, and horizontal direction is designated as the x direction.
Fig. 3 is the skeleton view of another conductor 34 of explanation operation of the present invention.Electric current I by conductor on the direction of arrow 36 expressions produces magnetic field H near conductor.
For the magnetic field amplitude of the film wire resemble Fig. 2, formula 1 is to estimate preferably.Do not describe this formula what done, but for recording process of equal importance be Distribution of Magnetic Field, the magnetic field gradient that is associated with this provenance especially.Big magnetic field gradient allows write head at lower track with cross on the both direction of magnetic track and write magnetic track with the steeper transformation between the phase ortho position, that is, with bit length and inter-track every comparing, transformation is than lacking.
Fig. 4 is the curve map that the live that is calculated of explanation operation of the present invention flows the Distribution of Magnetic Field of film wire.The square-section of conductor that the width that is had is shown is ten times of thickness is as item 38.The axial magnetic field that the electric current of conductor produces is flow through in curve 40 expression near conductor.The vertical magnetic field that the electric current of conductor produces is flow through in curve 42 expression near conductor.As shown in FIG. 4, the magnetic field that electric current produced in the lead is basically by the Karlqvist field distribution.
Field wire is that the centre of guiding line is substantially parallel or axially in the film wire plane, they have bigger vertical component near edge.For this live current wire, with the equal length scale of its width on, therefore the minimizing of its field amplitude suitably selects lead geometric configuration and size can obtain the needed big field gradient of magnetic recording.In fact, the field distribution of live stream film wire is the field distribution that the utmost point resembles the axial magnetic head of inductive.The live conductance wire loop described in Fig. 3 produces perpendicualr field, is given approx near its amplitude of center:
H ≅ μ o I 2 a - - - ( 2 )
Wherein 2a is the interior diameter of ring, described ring have conductor thickness t＜＜2a, width w be less than 2a or equally matched with 2a.Magnetic flux density near the ring center is bigger, and outside interior ring diameter, also have, with a or the equal length scale of w on, reduce fast.Formula 1 and 2 both illustrate, for fixed current, field amplitude increases inversely with conductor size, therefore an ampere magnetic head has inverted scalability.The typical prime amplifier that is used to coil the activation record magnetic head can provide the electric current up to 100 milliamperes approximately.Therefore range of current is fixed basically, and the lead that is loaded with electric current so only is about 100 nanometers or more hour can produces sizable (＞1 tesla) at its lateral dimension.For example, at the I=100 milliampere, w=100 nanometer (and/or a=100 nanometer), and during the t=30 nanometer, we are in J=3.3 * 10 9Ampere/centimetre 2The current density place obtain H ≅ 0.63 T (≡ 6.3 kilo-oersteds).For the I=100 ampere, w=25 nanometer (and/or a=25 nanometer) and t=8 nanometer, we are in J=5 * 10 10Ampere/centimetre 2The current density place obtain H ≅ 2.5 T . Generally, magnetic head to medium at interval (htms) should be less than or equal to the width and the length of lead approx, but more than or equal to the thickness of lead.The width of lead and length are the loss minimums that makes field intensity when the conductive line surfaces of leaving magnetic field intensity maximum (local field) moves more than or equal to the purpose of htms.Field amplitude with conductor size w and the equal length scale of l on reduce so that for htms less than w, the loss l minimum in the amplitude.On the other hand, the effect less than the conductor thickness of htms is that all current concentrations are got as far as possible near medium.Thicker lead makes current unit remove from medium, causes the field amplitude loss significantly of these unit, and this is the invalid operating position of electric current.Generally, conductor width is determined lower track bit resolution (definition), and should equal bit length approx, and conductor length is determined intersection magnetic track resolution simultaneously, and should equal the track width in the magnetic medium approx.We with following formula sum up we the invention in these design features:
T≤htms≤w, l ≈ bit length, track width, respectively.(3)
Nearest experiment shows that the current density of this amplitude order of magnitude is available really in the membrane structure of this size calibration.Show, use continuous current offset, the order of magnitude of length and width is that the current density of 100 nanometers or littler film wire heap is above 10 amperes/centimetre 2These heaps be basically separate by thin insulation course (～100 nanometer thickness), but at the thick metal film of the mutual electric contact in single point place, to form metal stack near 100 nanometer diameters and length.
We can design and make (and less) lead with similar geometry shape and size at suggestion, to be loaded with sizable current density, surpass 10 10Ampere/centimetre 2For example, the low-resistivity such as gold, silver or copper (ρ), the high conductivity material that are used for lead, make ohm (IR, R=ρ l/tw) heat is minimum, and can use weak point-time-scaled (discontinuous) current impulse (limiting extended period τ m) by the medium dynamic response, with the energy that further reduces to consume in the lead, flow the basic restriction of ability for the live of lead.Because will the less conductor size and the geometric configuration of single turn be discussed for write head below, the inductance of this lead will be minimum, less than picohenry, have the quite short response time of the psec order of magnitude.Also have, in most of metals, intrinsic electronic response time (relaxation time τ e) be inferior-psec (sub-picosecond), therefore, not limiting factor.Therefore, can easily be applied to these leads to the current impulse of psec extended period and the not loss of integrality of (at a high speed) signal.
The ampere wires write head has many advantages, such as using simply single-unit material for lead, resembles gold, silver or copper.As formula 1 and 2 predictions, the essentially no border of the upper limit of field amplitude is compared with the dynamics of magnetic material in the recording medium, and the response time of this magnetic head should be extremely short.In fact, the dynamics that can use the high speed performance of ampere magnetic head to come the activation record medium allows data rate to develop into and substantially exceeds a GHz.Therefore, when the size scale of magnetic recording head continues to dwindle, and in the restriction of available techniques the time, the live current wire becomes and produces and a kind of viable method of modulation local magnetic field, and described local magnetic field is for needed by writing magnetic transformation to the surface density of the magnetic recording of future development and data rate in recording medium preferably.
In Fig. 4, we from the width w that had than big many (w=10t) live current wire of thickness t provide normalized field amplitude (as along the Width that is parallel to lead, the x axle, the function of position) sketch.On the width of lead, the axial field component is quite smooth, except having bigger derivative (derivative) near edge's axial field component.Vertical component broad ways have a few and nearly all have bigger derivative.In fact, as previously pointed out, this field distribution comes down to undistinguishable for the field distribution in the gap of crossing axial inductive write device and the field distribution that equals the gap of conductor width.For example, by supposing the field peak value and the conductor width w=100 nanometer of 1 tesla, lead that can drawing for estimate 2 relevant axially and vertical (time-magnetic track) field gradient, the gradient of generation at least 200 oersteds/nanometer, this can be equally matched with the gradient of inductive write device.In the conductor loop design of here discussing, the intersection magnetic track field gradient of same magnitude is clear and definite (seeing Fig. 8,9,10,20,21,25 and 26), and has suitable geometric configuration, should can obtain with any ampere magnetic head of advising.Therefore, the lead that can design really as local field source produces needed field distribution of recording process and field gradient.The field amplitude that lead can produce finally is subjected to it and can bears and the restriction that do not have the current density of " thawing ".Formula 1 is not described the coboundary in the field amplitude.This determines by many designs and operating parameter that finally certain some conduct that we are discussed below wherein obtain high method from lead.
Fig. 5 is a view, and the timing diagram of the potential pulse of operating period of the present invention is described.The a series of time clock of curve 44 expressions.The a series of current impulses of curve 46 expressions.Do not set up the actual upper bound of the current density in the lead as yet, but all be suitable in the structure of ampere magnetic head, shown that the density of using the steady current biasing is greater than 10 in geometric configuration and size scale 9Ampere/centimetre 2In order to make the current capacity maximum of lead, it should be good conduction and heat conductor, resembles copper, silver or golden, and good heat conductor should be arranged around it.The length that is used to produce the lead in big magnetic field should be lacked as much as possible, because any unwanted extra length all can increase resistance.To the electrically contacting part and should make of lead by materials such as resembling gold, silver or copper, allowing the removing heat that produces in the lead effectively, and the size of contact portion to compare with lead be great.In addition, should handle assembly embed such as aluminium nitride, have can design the big heat conductivity of trying one's best, in the electric material of going up insulation, further to disperse the heat in the lead.Yet on some point, ohm heat on lead can need to make current cycle ground by do not damage lead to allow heat radiation really.The extended period that is applied to the electric current on the lead is short more, and it is just high more to apply current density.With technology of the present invention be can realize producing near 100 milliamperes, have with Fig. 5 in describe time-prime amplifier of the time proximity relation of nanosecond time scale, we the suggestion with Fig. 5 in the alike a kind of scheme of scheme, be used for electric current is put on ampere magnetic head so that the current density maximum that it can bear.
Only require that current impulse has the extended period τ of the required time of the magnetization that equals switchable dielectric Pulse(magnetic response/switching time τ m≤ τ Pulse).Time clock period τ Clock(inverse of～data rate ,～GHz) will be long as pulse duration at least because per two clock period will produce two pulses of inverse current polarity, so we obtain τ Clock〉=τ PulsePass through τ 0=τ Clock-τ PulseProvide zero current time τ 0, or cool time, will determine this time by employed current density and pulse duration.The lower boundary of setting up magnetic switching time preferably is for less than a nanosecond, and can be near the psec that be used for relevant magnetization rotation.If therefore the current impulse of extended period of using the psec order of magnitude, produces higher field so that obtain higher current density, then to compare with the actual clock period can be (the τ that extremely lacks to pulse duration Clock≈ τ Pulse).In this case, the ampere magnetic head will write by make track (footpront) in medium, and the field distribution that a position in its medium will be whole magnetic head surpasses a class " snapshot " at the coercivity place of medium at it.If τ Clock=τ PulseBe attainable, then an ampere magnetic head will resemble and operate traditional inductive write device, wherein when dragging the charging magnetic head when crossing the length of medium on the clock period, define a position, make the pole reversal of magnetic head then in the next one clock period.
The field distribution of Fig. 4 shows the difference place in the space, and lead produces " from-axle (off-axis) " field direction (vector), and wherein " from-axle " is meant have the isoplanar (axially) component and both vectors of Different Plane (component).Can require " from-axle " magnetic vector to be used for a kind of method of relevant rotation of magnetic recording process as the magnetization of the medium of inducting.To set up preferably and be, when making along the symmetry of given spatial axes by in order making when the reverse magnetic field that applies of this magnetization is destroyed, coherently to carry out along this magnetization oppositely, the chien shih magnetization is reverse when minimum.This also can provide by the current impulse of a series of timings, in order that during single ablation process, a plurality of field pulses are put on medium, with strengthen according to write saltus step the writing of time-consuming and needed field amplitude.As mentioned above, can on extremely short time scale (～psec), apply magnetic field from lead, thus during single ablation process applied field pulse train easily.Can easily be attached to this sequence in the timing scheme of describing among Fig. 5, wherein will during a clock period, apply a plurality of train pulses (have identical polarity, but may have different amplitudes and extended period).Therefore, our suggestion uses an ampere magnetic head to write for this " from-axle " vector field method, or changes and apply single magnetic field by whenever writing magnetic field, or by during single ablation process, applying magnetic field pulse sequence.The extended period of current impulse can be than the clock period much shorter.
Fig. 6 is the diagrammatic representation of the axial write head 48 of formation according to the present invention.Magnetic head comprise have the square-section, between two heat conduction and heat radiation devices 52 and 54, and be connected to the linear conductor 50 of this two heating radiator on electric.The area of section of heating radiator is more much bigger than the area of section of conductor 50.Current source 56 offers heating radiator and conductor to electric current.In operation, magnetic head be placed on magnetic recording media 58 near, and separate by air bearing (air bearing) 60 and medium.Electric current in conductor produces magnetic field H, and this magnetic field has the magnetization that enough intensity influences magnetic recording media.Current density in the current density ratio conductor 50 in heating radiator is much smaller.In the structure of Fig. 6, make the conductor orientation, so that the direction that is used to measure thickness is parallel to the surface of recording medium.This is called parallel-oriented.
Fig. 7 is the diagrammatic representation of another axial write head 62 of formation according to the present invention.Magnetic head comprise have the square-section, between two heat conduction and heat radiation devices 66 and 68, and be connected to the linear conductor 64 of this two heating radiator on electric.Current source 70 offers heating radiator and conductor to electric current.In operation, magnetic head be placed on magnetic recording media 72 near, and separate by air bearing (air bearing) 74 and medium.Electric current in conductor produces magnetic field H, and this magnetic field has the magnetization that enough intensity influences magnetic recording media.In the structure of Fig. 7, make the conductor orientation, so that be used to measure the surface of the direction of thickness perpendicular to recording medium.This is called vertical orientated.
As previous discussion, the current density in lead surpasses 10 10Ampere/centimetre 2The time, the field amplitude of field amplitude and inductive magnetic recording head is equally matched, H～2 teslas.Therefore, in Fig. 6 and 7, we describe can be used as the lead geometric configuration that axial write head uses.Direction of current flow is determined magnetic field orientating, and we show two possible orientations in Fig. 6 and 7.Make this current reversal be accompanied by magnetic direction oppositely, therefore, modulated electric current produces and can be used for corresponding modulation of a series of opposite polarity magnetic transition of record in recording medium, as shown in Fig. 6 and 7.As mentioned above, for example, can constitute contact mat by gold, silver or copper, play electric contact of Low ESR and low thermal resistance heating radiator effect.The length (1) of a lead that is used to produce should be littler than the size of these contact mats, and equally matched with conductor width, so hot-fluid can flow to heating radiator by low thermal resistance, prevents damage lead when applying high current density.The Distribution of Magnetic Field of the live in Fig. 4, represented stream film wire with sketch in fact with have with the axial inductive magnetic head of the equal gap size of conductor width to write the Distribution of Magnetic Field that the gap produces be undistinguishable.Among Fig. 6 and 7 the main difference of two kinds of structures be film wire width among Fig. 6 be perpendicular to sliding shoe air abutment surface (ABS) (promptly, parallel with the wafer surface during magnetic head is made), and in Fig. 7, conductor width is parallel to the air abutment surface.Every kind of wire orientation all is feasible, and two kinds of lead geometric configuratioies of hint (conclusivelying show in some design) are to use together with given ampere magnetic head design in whole explanation.By considering describing in above-mentioned field distribution and Fig. 2 and 3, and conclusive size and field amplitude by considering that given magnetic head design needs, can determine optimal wire orientation.Also have, because the standard head manufacturing needs a process of lapping of sliding shoe, so grinding control (resolution (resolution)) will determine to use which kind of wire orientation.For example, in the lead plane parallel in the situation of ABS, by process of lapping come pilot thickness (T＜＜W), process of lapping may be or may not be a kind of feasible means of pilot thickness.Therefore, under the situation of the geometric configuration of ampere magnetic head and conclusive feature, desired field distribution and field gradient should be available at chosen axis suitably.
Fig. 8 is the diagrammatic representation that is used for the current-carrying conductor 76 that vertically writes at write head constructed according to the invention, conductor generally has the square-section, and make it form the shape of a ring, so that the electric current in the conductor that provides by external current source 78 produces magnetic field H, and this magnetic field has the magnetization that enough intensity influences magnetic recording media 80.This has produced perpendicular magnetization zone M in magnetic recording media.We schematically describe to be applicable to a kind of lead geometric configuration of the perpendicular recording among Fig. 8.Circular rings is in the write field of ring center, high magnetic flux density zone and appointment and the difference that allows maximum between the magnetic flux density that the outside produced of the low relatively ring of magnetic flux density.
Fig. 9 is the diagrammatic representation of another current 82 of being used for vertically writing at write head constructed according to the invention.Conductor generally has the square-section, and makes its shape that forms a ring, so that the electric current in the conductor that provides by external current source 84 produces magnetic field, and this magnetic field has the magnetization that enough intensity influences magnetic recording media 86.The straight-flanked ring geometric configuration of Fig. 9 has than the easy advantage that manufactures write head of circular rings, when the planar quadrature of air seating plane (ABS) in magnetic head is made and wafer, makes the garden shape structure at ABS place be difficult to manufacturing.Yet it is so big not resemble circular rings in the write field amplitude of ring center and the write field amplitude outside ring.
Figure 10 is the diagrammatic representation that is used for another write head 88 that vertically writes constructed according to the invention.Write head 88 comprises the U-shape conductor 90 that generally has the square-section.Conductor is connected to first and second conductive heat sinks 92 and 94 that receive the electric current that external current source 96 provides, has the magnetic field H that enough intensity influences the magnetization of magnetic recording media 98 with generation.The straight-flanked ring geometric configuration of Figure 10 has than the easy advantage that manufactures write head of circular rings, when the planar quadrature of air seating plane (ABS) in magnetic head is made and wafer, makes the garden shape structure at ABS place be difficult to manufacturing.When magnetic medium moves with respect to magnetic head, in medium, produce the zone of magnetization M.
Figure 11 is the diagrammatic representation that is used for another write head 100 that vertically writes constructed according to the invention.Write head 100 comprises first and second linear conductors 102 and 104, and each conductor generally has the square-section.First end of conductor 102 is connected to first conductive heat sink 106, and second end of conductor 102 is connected to second conductive heat sink 108.First end of conductor 104 is connected to the 3rd conductive heat sink 110, and second end of conductor 104 is connected to second conductive heat sink 108.Connect heating radiator 106 and 110 and receive the electric current that provides by external current source 112 to produce magnetic field H, this magnetic field has the magnetization that enough intensity influences magnetic recording media 114.
Figure 12 is the diagrammatic representation that is used for another write head 116 that vertically writes constructed according to the invention.Write head 116 comprises first and second linear conductors 118 and 120, and each conductor generally has the square-section.First end of conductor 118 is connected to first conductive heat sink 122, and second end of conductor 118 is connected to second conductive heat sink 124.First end of conductor 120 is connected to the 3rd conductive heat sink 126, and second end of conductor 120 is connected to second conductive heat sink 124.Connect the electric current generation magnetic field H that heating radiator 122 and 124 receives to be provided by external current source 128, this magnetic field has the magnetization that enough intensity influences magnetic recording media 130.
Figure 10,11 and 12 write head are the modification of the straight-flanked ring that divides in conjunction with electric contacting part, described electric contacting part branch are designed to the heating radiator that can flow in the situation of low thermal resistance from the hot-fluid that ohm is warm in the lead.Figure 11 and 12 frame geometry allow the conductor length between the heating radiator the shortest, make electrical impedance and thermal resistance both for minimum.As describing in Figure 11 and 12, have the main perpendicualr field (H) between the mobile couple of conductor generation lead of loop current, and magnetic direction is reverse outside loop, but has littler magnetic flux.
Figure 13 is the diagrammatic representation that is used for another write head 132 that vertically writes constructed according to the invention.Write head 132 comprises the single conductor 134 with leading edge 136 and back edge 138, is installed between first and second heating radiators, and adds electric first and second heating radiators 140 and 142 of being connected to.External current source 144 offers conductor to electric current.Can also be being used for the perpendicular recording of magnetic medium 146 such as the single lead write head of in Figure 13, describing, and be the easiest manufacturing.
Figure 14 is the diagrammatic representation that is used for the write head that axially writes 148 constructed according to the invention.Magnetic head 148 comprises the linear conductor 150 with square-section.Conductor is placed between first and second ferromagnetic thin films 152 and 154.The field distribution in the gap of crossing over axial write device has been duplicated in the field distribution of lead.Therefore, magnetic flux density increases and field distribution is constant substantially.Can be placed on lead in the space in the write head, to produce the extremely identical field distribution with write head.First end of conductor 150 is connected electrically to first conductor 156, and second end of conductor 150 is connected electric second conductor 158 of receiving.Conductor 156 and 158 is connected to external current source 160.The electric current I that flows in conductor 150 produces magnetic field H, and this magnetic field has the axial region that enough intensity produces the magnetization M in the magnetic recording media 162.
Figure 15 is the diagrammatic representation that is used for the write head that axially writes constructed according to the invention.Magnetic head 164 comprises the linear conductor 166 with square-section.Conductor is placed between first and second ferromagnetic thin films 168 and 170.First end of conductor 166 is connected electrically to first conductor 172, and second end of conductor 166 is connected electric second conductor 174 of receiving.Conductor 172 and 174 is connected to external current source 176.The electric current I that flows in conductor 166 produces magnetic field H, and this magnetic field has the axial region that enough intensity produces the magnetization M in the magnetic recording media 178.
Figure 16 is the diagrammatic representation that is used for another write head 180 that vertically writes constructed according to the invention.Write head 180 comprises first and second linear conductors 182 and 184, and each conductor generally has the square-section.First end of conductor 182 is connected to first conductive heat sink 186, and second end of conductor 182 is connected to second conductive heat sink 188.First end of conductor 184 is connected to the 3rd conductive heat sink 190, and second end of conductor 184 is connected to second conductive heat sink 188.Ferromagnetic material layers 192 is placed between the linear conductor.Connect heating radiator 186 and 190 and receive the electric current that provides by external current source to produce magnetic field H, this magnetic field has the magnetization that enough intensity influences magnetic recording media 194.In Figure 16, make the surface of the orientation of conductor perpendicular to recording medium.
Figure 17 is the diagrammatic representation that is used for another write head 196 that vertically writes constructed according to the invention.Write head 196 comprises first and second linear conductors 198 and 200, and each conductor generally has the square-section.First end of conductor 198 is connected to first conductive heat sink 202, and second end of conductor 198 is connected to second conductive heat sink 204.First end of conductor 200 is connected to the 3rd conductive heat sink 206, and second end of conductor 200 is connected to second conductive heat sink 204.Ferromagnetic material layers 2082 is placed between the linear conductor.Connect heating radiator 202 and 206 and receive the electric current that provides by external current source to produce magnetic field H, this magnetic field has the magnetization that enough intensity influences magnetic recording media 210.In Figure 17, make the orientation of conductor be parallel to the surface of recording medium.
In Figure 14 and 15 and 16 and 17, we provide the design of axial and vertical ampere magnetic head, wherein combine soft, high 4 π M sFerromagnetic (F) material support from the ampere magnetic head the field.Thin magnetic film will have and the equal size of lead, because bigger demagnetizing field, this will cause the quite big shape anisotropy of the magnetization.Therefore, this " soft " magnetic material effect on magnetic is also harder than the performance of its bulk, institute so that material is magnetized, essential enough greatly from the field of ampere magnetic head, to obtain the overlapping advantage of field from lead and magnetic material.On this meaning, ampere magnetic head and magnetic material will have equal contribution for write field.Certainly, can be similarly magnetic material be attached in vertical design discussed here any.
Figure 18 is the diagrammatic representation that is used for another write head 212 that axially writes constructed according to the invention.Write head 212 comprises the yoke 214 that forms the first and second pole tip ends 216 and 218.Coil 220 is installed in the yoke, with in yoke, induct magnetic field and be created in the magnetic field H of extending between the pole tip end of the electric current in the induced coil.Linear conductor 224 with square-section is placed in the space between the pole tip end.First end of linear conductor is connected to second conductor 226, and second end of linear conductor is connected to the 3rd conductor 228.The second and the 3rd conductor is connected to external current source 230.The axial region of magnetization M in the magnetic flux induced magnetism recording medium 232 between the pole tip end.The field distribution of the magnetic flux that the electric current that flows through in conductor produces is identical with the field distribution of the magnetic flux of crossing over the generation of pole tip end basically.Current density in the current density ratio coil in conductor is much bigger.
Figure 19 is the diagrammatic representation that is used for another write head 234 that axially writes constructed according to the invention.Write head 234 comprises the yoke 236 that forms the first and second pole tip ends 238 and 240.Coil 242 is installed in the yoke, with in yoke, induct magnetic field and be created in the magnetic field H of extending between the pole tip end of the electric current in the induced coil.Linear conductor 244 with square-section is placed between the pole tip end.First end of linear conductor is connected to second conductor 246, and second end of linear conductor is connected to the 3rd conductor 248.The second and the 3rd conductor is connected to external current source 250.The axial region of magnetization M in the magnetic flux induced magnetism recording medium 252 between the pole tip end.As in the write head of Figure 18, the field distribution of the magnetic flux that the electric current that flows through in conductor produces is identical with the field distribution of the magnetic flux of crossing over the generation of pole tip end basically.Current density in the current density ratio coil in conductor is much bigger.
Traditionally, passed through the saturation magnetization of the magnetic material of increase inductive write head, or 4 π M sValue, and obtain being written into hard medium, therefore support to put on the magnetic field of medium.Though at M for increase utmost point material sInvestigation of materials effort aspect obtained some successes, the annual growth of the plane density but the speed that increases is nowhere near in the support disc storer.We provide a kind of method, thereby ampere magnetic head is combined with the inductive write device, with the local field amplitude of supporting to surmount to some extent than the available local field amplitude of design new material.In Figure 18 and 19, show this two kinds of designs that axially write, wherein film wire is placed in the gap of the axial write device of inductive, on electric, insulate to cause lead and yoke in conjunction with magnetic head.As shown in the figure, when simultaneously in lead and coil, applying electric current, be in the same place from adding of axial write device of inductive and ampere magnetic head, to increase magnetic flux density partly.For example, have a lead if having the inductive write device of the saturation magnetization of 2.4 teslas, this lead is loaded with electric current I=100 milliampere, and that crosses over width w=100 nanometer and thickness t=30 nanometers writes (J=3.3 * 10, gap 9Ampere/centimetre 2), we obtain the total magnetic field of about 3 teslas H ≅ 0.63 The complementary field of tesla.
Figure 20 is the diagrammatic representation that is used for the write head that vertically writes 254 constructed according to the invention.Write head 254 comprise have write the utmost point 258 and return the utmost point 260 yoke 256.Place coil 262 and make the magnetic flux of inducting in the yoke.Make conductor 264 form to center on and write a ring of the utmost point, and be connected to external current source 266 with square-section.The combination results magnetic field H of the electric current in coil 262 and the conductor 264, the magnetization of this influence of magnetic field magnetic recording media 268.
Figure 21 is the diagrammatic representation that is used for another write head 270 that vertically writes constructed according to the invention.Magnetic head 270 comprise have write the utmost point 274 and return the utmost point 276 yoke 272.Place coil 278 and make the magnetic flux of inducting in the yoke.Make conductor 280 form to center on and write a ring of the utmost point, and be connected to external current source 282 with square-section.The combination results magnetic field H of the electric current in coil 278 and the conductor 280, the magnetization of this influence of magnetic field magnetic recording media 284.
Figure 22 is the diagrammatic representation that is used for another write head 286 that vertically writes constructed according to the invention.Magnetic head 286 comprise have write the utmost point 290 and return the utmost point 292 yoke 288.Place coil 294 and make the magnetic flux of inducting in the yoke.First linear conductor 296 that placement has the square-section makes it a contiguous side that writes the utmost point.Second linear conductor 298 that placement has the square-section makes it the contiguous opposite side that writes the utmost point.First end of first linear conductor is connected to first heating radiator 300.Second end of first linear conductor is connected to second heating radiator 302.First end of second linear conductor is connected to the 3rd heating radiator 304.Second end of second linear conductor is connected to second heating radiator 302. Heating radiator 300 and 304 is connected to external current source.The combination results magnetic field H of the electric current in coil 294 and two linear conductors 296 and 298, the magnetization of this influence of magnetic field magnetic recording media 306.
Figure 23 is the diagrammatic representation that is used for another write head 308 that vertically writes constructed according to the invention.Magnetic head 308 comprise have write the utmost point 312 and return the utmost point 314 yoke 310.Place coil 316 and make the magnetic flux of inducting in the yoke.First linear conductor 318 that placement has the square-section makes it a contiguous side that writes the utmost point.Second linear conductor 320 that placement has the square-section makes it the contiguous opposite side that writes the utmost point.First end of first linear conductor is connected to first heating radiator 322.Second end of first linear conductor is connected to second heating radiator 324.First end of second linear conductor is connected to the 3rd heating radiator 326.Second end of second linear conductor is connected to second heating radiator 324.Heating radiator 324 and 326 is connected to external current source.The combination results magnetic field H of the electric current in coil 316 and two linear conductors 318 and 320, the magnetization of this influence of magnetic field magnetic recording media 328.
In Figure 20-23, we describe to have " list-utmost point " the vertical inductive write device through the ampere magnetic head of combination.In this case, lead will become ring and around one pole, producing a perpendicualr field that adds the perpendicualr field that sends from surface extremely partly to, by supporting available field amplitude with the similar manner of above-mentioned discussion of axial simulation for it.
Figure 24 is the diagrammatic representation that is used for another write head 330 that vertically writes constructed according to the invention.Magnetic head 330 comprise have write the utmost point 334 and return the utmost point 336 yoke 332.Place coil 338 and make the magnetic flux of inducting in the yoke.First linear conductor 340 that placement has the square-section makes it a contiguous side that writes the utmost point.First end of first linear conductor is connected to first heating radiator 342.Second end of first linear conductor is connected to second heating radiator 344.The combination results magnetic field H of the electric current in coil 338 and the linear conductor 340, the magnetization of this influence of magnetic field magnetic recording media 346.
Figure 21,22,23 and 24 is modification of making the design of better simply Figure 20, and under Figure 22,23 and 24 situation, we show a kind of method that is used in conjunction with the heating radiator of high current density.The simplest enforcement through the magnetic head of combination is represented in the design of Figure 24.Principle of work is based on such fact, that is, the single pole inductive magnetic head uses perpendicualr field to write the magnetic saltus step in its rear edge, because the decline of the utmost point that this edge is a medium " to be seen ".Therefore, be enough to be supported in partly the field of rear edge, opposed with the design on the whole pole-face at ABS place is long-pending that Figure 21,22 and 23 is carried out, although having, these designs produce big advantage for given electric current.As a result, as describing in Figure 24, we can be in conjunction with the lead of adjacent rear edge, so that the perpendicualr field that produces in the antemarginal lead edge near the utmost point is supported write field.Also need to keep the big field gradient of rear edge, as indicated in Fig. 4, the steep perpendicualr field distribution of lead is overlapped in the field distribution of the utmost point.In fact, this all is real for above-mentioned all designs.
The big field gradient of the lead and the utmost point make they not electric the contact and as much as possible near become imperative, otherwise overlapping they the field buttressing effect will disappear owing to space loss.Electrical isolation is not shown in Figure 14-24 clearly, and to be in a ratio of minimum insulation course also be suitable but have thickness and conductor width between them.Owing to constitute the wafer that is orthogonal to ABS, so the insulation course (axially with vertical two kinds of designs) that leading edge that makes lead and the utmost point and back edge are separated is placed to such an extent that be parallel to wafer surface, therefore, can suitably place by the thickness of about 1 nanometer is extremely all even, cause for 50 nanometers or the bigger utmost point and the field space loss minimum of conductor size.Also have, for example, the resistivity of utmost point material general (maybe can be designed to) is than big one to two the amplitude order of magnitude of resistivity of copper (and have equal size, this is interpreted as bigger electrode resistance), so electrically contacting of the lead and the utmost point may not can produce any tangible lead leakage current.Therefore, the lead and the utmost point can be placed close together arbitrarily, have in fact eliminated any space loss.
The another kind of method that writes down on than the high coercivity medium is the temperature of magnetic material of raising partly and temporarily, has therefore reduced its coercivity relevant with temperature applying the moment that magnetic field writes a transformation.A kind of method of heating is to come excitable media with the high-energy-density electromagnetic radiation.A kind of technology of so carrying out comprises uses optical laser to encourage a metal " antenna ", and this antenna has a small-bore, is used for the high-energy-density electromagnetic radiation through excitation is coupling in the near field.Near-field thermal radiation spreads on the length scale of the aperture size order of magnitude, makes the medium spot heating, and reduces coercivity during ablation process.Optical antenna must combine with an inductive write device, so that radiation field is spatially temporary transient consistent with write field.This technology is called optics assisted magnetic recording (Optically Assisted Magnetic Recording (OAMR)).Do not show the work design of this magnetic head as yet, and to make this device will be very difficult.
Figure 25 is the diagrammatic representation that is used for another write head 348 that vertically writes that comprises OAMR string tie structure constructed according to the invention.Magnetic head 348 comprises the ring 350 of the conductor 352 with square-section, and is placed between two string tie segmentations 354 and 356.Electric current in ring produces magnetic field, and this magnetic field is used for writing of adjacent magnetic recording media.The string tie segmentation forms an antenna, uses this antenna to increase the temperature of the magnetic recording media in the zone that will write.
Figure 26 is the diagrammatic representation that is used for another write head 358 that vertically writes that comprises OAMR string tie structure constructed according to the invention.Magnetic head 358 comprises ring 360, and this ring comprises the pair of conductors 362 and 364 that is connected to two string tie segmentations 366,368 and 370. Segmentation 366 and 370 is connected to external current source, and electric current produces the magnetic field that is used to write adjacent magnetic recording media in ring.
Figure 27 is the diagrammatic representation that is used for another write head 372 that vertically writes that comprises OAMR string tie structure constructed according to the invention.Magnetic head 372 comprises ring 374, and this ring comprises the pair of conductors 376 and 378 that is connected to two string tie segmentations 380,382,384 and 386.Be electrically connected segmentation 382 and 384 by conductor 388. Segmentation 380 and 386 is connected to external current source, and electric current produces the magnetic field that is used to write adjacent magnetic recording media in ring.
The design of Figure 25 combines vertical ampere magnetic head and optical antenna, especially, combines the antenna that is called as the string tie antenna.From sending the radiation field of laser instrument excitation between two parts of the string tie of placing ampere wires, radiation field and magnetic field take place in medium simultaneously then.This idea is to replace the inductive write head of above-mentioned OAMR design simply with the ampere magnetic head.In conjunction with design be not limited to the conductor loop of Figure 25, or be used for the perpendicular recording of this situation, but can be more generally in conjunction with all amperes magnetic head discussed here.Discussed above and used the ampere magnetic head to produce some advantages of field, additional advantage can be greater flexibility and the design of making combination easily.For example, copper and silver are that material is selected preferably for an antenna and an ampere magnetic head both, so can make the lead of ampere magnetic head and optical antenna integrated, describe a kind of so method with the realization of string tie antenna in Figure 26.In Figure 27, we describe a kind of design of combination, and it has distinct string tie, and this has improved heat transfer efficiency than the design shown in Figure 25, are cost with some magnetic field amplitude still.In Figure 25-27, in the explanation string tie antenna structure, should be appreciated that, in write head of the present invention, can also use the antenna structure of other variation.
The more detailed analysis of live current wire further shows as the feature of the presently claimed invention that is used for the local field source of magnetic recording.Figure 28 is the diagrammatic representation that can be used to further specify the write head of operation of the present invention.The write head 400 of Figure 28 comprises film wire 402, and film wire 402 is connected electrically to two contact portions 404 and 406 that also play the heating radiator effect, and is placed between them.Use current source 408 that electric current is offered lead and contact portion.Lead is placed on magnetic head air abutment surface 410 near.Can be with myopia in the size of high density recording and easily make structure among Figure 28.
For the specific device geometric configuration of in Figure 28, schematically describing, use finite element moulding (FEM) (finite element modeling) technology to calculate local magnetic field and distribute.In the example of moulding, make the lower track direction width w of intersection track direction length 1,30 nanometers and 5 nanometers with 100 nanometers thickness copper conductor 402 each end of lead with along x direction 500 nanometers, contact along y direction 300 nanometers with along the copper contact portion 404,406 of z direction 750 nano-scales.Lead directly and ABS surface 410 put together, and be placed on along the center of z direction.Drive 100 milliamperes electric current by lead, in lead, produce about 6 * 10 10Ampere/centimetre 2Current density.On the current density that this current density has just been reported in article, for example, locate to drive 1.8 * 10 of DC (direct current) biasing continuously by 10 nanometer diameter carbon nano-tube (nanotube) at high temperature (250 ℃) 10Ampere/centimetre 2Current density.
In lead (30 nanometers * 5 nanometers) and contact portion (750 nanometers * 300 nanometers, 500 nanometers * 300 nanometers or 500 nanometers * 750 nanometers, depend on sense of current) between the big-difference of area of section cause the big-difference of their current densities separately, therefore, cause big-difference between the magnetic field that their produce.This causes producing big magnetic field partly by lead, and this reduces sharp in the amplitude that surpasses the lead boundary.
Figure 29 is the curve map that the live of structure among Figure 28 flows the Distribution of Magnetic Field of film wire.Figure 29 illustrates the lower track field distribution of axial field 412 and perpendicualr field 414, is at the center of conductor length and leaves ABS and do not have the distance of conductive line surfaces 20 nanometers (along the y direction) at the place, hypothesis medium bottom of soft magnetism lower floor to measure.The peak amplitude that can see the axial component in magnetic field is about 6000 oersteds, have peak field's gradient (slope) of about 160 oersteds/nanometer, and perpendicualr field is respectively about 4000 oersteds and 140 oersteds/nanometer.
Figure 30 is another curve map that the live of structure among Figure 28 flows the Distribution of Magnetic Field of film wire.Figure 30 illustrate when at thickness be 35 nanometers and normalization magnetoconductivity be μ=50, when placing soft magnetism lower floor (SUL) under the hypothetical record layer 20 nanometer, medium below the ABS, the lower track field distribution of axial field 416 and perpendicualr field 418.Therefore, at the top of SUL, or equivalently,, measure the data of Figure 30 in the bottom of recording layer.SUL is suitable for perpendicular magnetic recording, can be clear that from data, has strengthened perpendicualr field when suppressing vertical component.Have an appointment now the peak value perpendicualr field of 7500 oersteds and peak field's gradient of about 270 oersteds/nanometer.
Figure 31 is another curve map that the live of structure among Figure 28 flows the Distribution of Magnetic Field of film wire.Figure 31 be illustrated in the place, bottom of hypothesis medium with no soft magnetism lower floor and in field amplitude for maximum lower track position, from the intersection magnetic track field distribution (with reference to Figure 29 and 30) of the axial field 420 and the perpendicualr field 422 of ABS 20 nano measurements.
Figure 32 illustrate when soft magnetism lower floor (SUL) is placed on have 35 nano thickness and normalization magnetoconductivity be μ=50, below the ASB below the hypothetical record layer 20 nanometer, medium the time, the intersection magnetic track field distribution of axial field 424 and perpendicualr field 426.In the specific examples of perpendicualr field component, show 100 oersteds are arranged/field gradient that nanometer is so big along intersecting track direction with SUL.
The present invention forces at big-difference in the current density between lead and the contact portion, and this causes the needed sizable intersection magnetic track field gradient of high density magnetic recording.For example, suppose that the average current density of the contact portion in the above-mentioned molding structure of current density ratio in the lead is big 100 times.Also have, the effect of jumbo contact portion with quite low current density is as the high heat conduction and heat radiation device of the heat that produces in can the venting lead.In addition, the conductor length of being advised (1≤100 nanometer) is equally matched or littler than it with the electronics mean free path (～100 nanometer) in the typical metal, and this will help to make ohm heat (because the itinerant electron scattering result causes) minimum in the lead.These field distribution and their corresponding amplitudes and gradient are for reach 100 megabit/inches by area density 2To write be enough big, certainly,, can also expand this to higher area density by using less conductor size and/or producing other device geometric configuration big field amplitude, discussed here by using for the same current that is applied.The moulding result shows the survivability of the present invention as the write head that is used for high density magnetic recording.
(its medium is lithographic to figuratum medium, or in addition, in the array of the ordering of the isolated area (island) of magnetic material, determine, described magnetic material has size and the space that is suitable for desired position-area density) will be the ideal material that is used for ampere magnetic head, determine the position shape because be largely by the pattern of medium rather than by magnetic head.Therefore, can loosen producing the needed Distribution of Magnetic Field in position, so that only need define its space distribution preferably, make it to magnetize an isolated area and can not magnetize adjacent isolated area.Field pulse extended period has relation very in short-term especially using track (footprint) method that writes for this, and by on isolated area, applying the isolated area magnetization that magnetic field makes figuratum magnetic medium equably near-instantaneous.
Use the ampere magnetic head that many advantages are arranged.Can make magnetic head with traditional material, manufacture process and lithography technique.Especially, the film wire material can be simple individual element gold, silver or copper or or the like.The lead geometric complexity is lower, and should use known procedure directly to make.Compare with magnetic material, the dynamic response of magnetic head should be exceedingly fast, and makes higher data speed more reliable.In fact, the dynamics that can use the high speed capability of ampere magnetic head to come the activation record medium allows to make data rate to bring up to preferably above GHz (megahertz).There is the possibility that produces the magnetic field higher than the available magnetic field of any other method.The magnetic field that produces by the live current wire when conductor size is dwindled has increased fixed current, and therefore the ampere magnetic head has reverse scalability (reverse scalability).The low-complexity of conductor structure makes them be fit to combine with various forms of current techniques and these technology are brought up to above they current limit.At last, for many reasons of mentioning just now, the manufacturing of ampere magnetic head should be relatively not expensive, makes it become feasible magnetic recording head in a kind of future.Therefore, when the calibration of the size of magnetic recording head continue to dwindle and limited field in available techniques in the time, the live current wire becomes and produces and a kind of feasible method of modulation local magnetic field, and described local magnetic field is that to write magnetic transition needed by making magnetic recording bring up to the area density of advanced technology in the future and data rate preferably in recording medium.
The invention provides a kind of method, be used for producing local magnetic field from the live current wire at magnetic recording head.The geometric configuration that can define lead is to produce the axial or vertical magnetic field with respect to the plane of magnetic recording media.The strict size of lead and its geometric configuration determine to use the size scale of the magnetic potential that this method writes, and only the lithography technique by standard comes exclusive size.Suitable high current density and signal frequency are being put under the situation of the lead that is defined by lithography, can produce local magnetic field respectively and modulate by sufficiently high frequency with enough magnetic fluxs, with by make magnetic recording bring up to preferably the area density of advanced technology in the future and data rate information stores in recording medium.
When having described specific embodiment of the present invention here for illustrative purposes of the present invention rather than in order to limit purpose of the present invention, those skilled in the art that will appreciate that, can make many modifications of details, material and configuration for parts under the condition that does not depart from the scope of the present invention that defines in appending claims.

Claims (26)

1. a kind of method of recording information bits in magnetic storage medium, described method comprises:
Place first conductor (50) and make it contiguous magnetic recording media (58), described conductor has width and length, and wherein the distance between first conductor and the described magnetic recording media is less than or equal to described width and length; And
Make the electric current of enough amplitudes flow through described conductor in magnetic medium, producing magnetic field, and on a position size, have magnetic field gradient on track direction and the lower track direction intersecting greater than 100 oersteds/nanometer greater than 1 tesla.
2. the method for claim 1 is characterized in that, described width and length equal bit length and the track width in the magnetic recording media approx.
3. the method for claim 1 is characterized in that, described first electric current is less than 100 milliamperes.
4. the method for claim 1 is characterized in that, the current density in described first conductor is greater than 10 9Ampere/centimetre 2
5. the method for claim 1 is characterized in that, each in the length of first conductor, width and the thickness is all less than 100 nanometers.
6. the method for claim 1 further comprises:
Place ferromagnetic material layers (152) and make it contiguous first conductor; And
Use ferromagnetic material layers to increase magnetic field.
7. the method for claim 1 further comprises:
Writing the utmost point (290) and returning described first conductor of placement between the utmost point (292) in yoke (288);
Make second electric current flow through coil (294) in yoke, to produce magnetic flux; And
Use the magnetic flux in the yoke to increase magnetic field.
8. the method for claim 1 further comprises:
Placement antenna (354,356) makes it with described first conductor vicinity and combines; And
Use antenna that magnetic medium is heated.
9. the method for claim 1 further comprises:
Place second conductor (184) and make it contiguous magnetic recording media and be parallel to described first conductor, described second conductor has width and thickness, and wherein width is greater than thickness; And
Make second electric current flow through second conductor to increase magnetic field.
10. the method for claim 1 is characterized in that, described first electric current comprises that the extended period is less than the predetermined clock current impulse of cycle length.
11. the method for claim 1 is characterized in that, in the time cycle of extended period of predetermined clock cycle length, described first electric current comprises a plurality of current impulses.
12. the method for claim 1 is characterized in that, described first conductor has the thickness that is less than or equal to the distance between described first conductor and the described magnetic recording media.
13. the method for claim 1 is characterized in that, the step that described first electric current flows through described conductor is comprised:
Make described first electric current flow through first contact portion (52) of first end that is connected to described first conductor;
And
Make described first electric current flow through second contact portion (54) of second end that is connected to described first conductor;
Wherein the average current density in described first conductor is bigger 1000 times than the average current density in each of first and second contact portions.
14. a kind of write head with magnetic storage medium uses comprises:
First conductor (50) with width and length;
Device (18) is used to place first conductor and makes it contiguous magnetic recording media, and wherein the distance between first conductor and the described magnetic recording media is less than or equal to described width and length; And
Device (56), be used for making first electric current of enough amplitudes to flow through first conductor producing magnetic field at magnetic medium, and on a position size, have magnetic field gradient on track direction and the lower track direction intersecting greater than 100 oersteds/nanometer greater than 1 tesla.
15. write head as claimed in claim 14 further comprises:
The ferromagnetic material layers (152) of contiguous described first conductor.
16. write head as claimed in claim 14 further comprises:
Have the yoke (288) that writes the utmost point (290) and return the utmost point (292), wherein be placed on and write the utmost point and return between the utmost point stating first conductor; And
Coil (294) is used for producing magnetic flux in yoke.
17. write head as claimed in claim 14 further comprises:
The antenna (354,356) contiguous with described first conductor.
18. write head as claimed in claim 14, it is characterized in that, be used to place device that described first conductor makes it contiguous described magnetic recording media and further place distance between described first conductor so that described first conductor and the described magnetic recording media more than or equal to the thickness of described first conductor.
19. write head as claimed in claim 14 is characterized in that, the device that described first electric current flows through described first conductor is comprised:
Be connected to first contact portion (52) of first end of described first conductor; And
Be connected to second contact portion (54) of second end of described first conductor;
Wherein the area of section of each in first and second contact portions is bigger 1000 times than the area of section of described first conductor.
20. a disk drive storage system comprises:
Shell (12);
Support is placed on the device of the magnetic storage medium in the shell; And
Device (18), be used to place write head and make it contiguous described rotatable magnetic storage medium, described write head comprises first conductor (50) with width and length, and the distance between wherein said first conductor and the described magnetic recording media is less than or equal to described width and length; And a kind of device, be used for making first electric current of enough amplitudes to flow through described first conductor producing magnetic field at magnetic medium, and on a position size, have magnetic field gradient on track direction and the lower track direction intersecting greater than 100 oersteds/nanometer greater than 1 tesla.
21. disk drive storage system as claimed in claim 20 is characterized in that, described write head further comprises:
The ferromagnetic material layers (152) of contiguous described first conductor.
22. disk drive storage system as claimed in claim 20 is characterized in that, described write head further comprises:
Have the yoke (288) that writes the utmost point (290) and return the utmost point (292), wherein be placed on and write the utmost point and return between the utmost point stating first conductor; And
Coil (294) is used for producing magnetic flux in yoke.
23. disk drive storage system as claimed in claim 20 is characterized in that, described write head further comprises:
The antenna (354,356) contiguous with described first conductor.
24. disk drive storage system as claimed in claim 20 is characterized in that, described write head further comprises:
Second conductor of placing parallelly (184) with described first conductor.
25. disk drive storage system as claimed in claim 20, it is characterized in that, be used to place described first conductor of the further placement of device that write head makes it contiguous described rotatable magnetic storage medium, so that the distance between described first conductor and the described magnetic storage medium is more than or equal to the thickness of described first conductor.
26. disk drive storage system as claimed in claim 20 is characterized in that, the device that described first electric current flows through described first conductor is comprised:
Be connected to first contact portion (52) of first end of described first conductor; And
Be connected to second contact portion (54) of second end of described first conductor;
Wherein the area of section of each in first and second contact portions is bigger 1000 times than the area of section of described first conductor.
CNA028168011A 2001-08-28 2002-02-27 Recording heads using magnetic fields generated locally from high current densities in a thin film wire Pending CN1550003A (en)

Applications Claiming Priority (2)

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US31546701P 2001-08-28 2001-08-28
US60/315,467 2001-08-28

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CN1829291B (en) * 2004-12-01 2012-11-14 三菱电机株式会社 Sensing apparatus, method for sensing energy field and camera

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