JP2002304703A - Method for magnetizing magnetic disk plane and head, recording head, and hard disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device capable of forming a higher bit density on a magnetic disk plane without affecting adversely the reproduction. SOLUTION: A head is characterized in that a head 800 used for magnetizing the disk plane of a magnetic disk having a plurality of tracks includes a recording means to generate a magnetic field in a direction roughly perpendicular to the disk plane, the recording means includes an upper pole 820 and a lower pole 830, and the upper pole 820 has a primary width and a secondary width narrower than the primary width, and the secondary width is closer to the disk plane than the primary width. The above structure is preferable especially for the process of perpendicular magnetic recording. A recording head includes a reading pole and a trailing pole having a roughly concave portion 840 along its trailing edge. This roughly concave portion induces an improved magnetic field over the recording head 800, and thus a much higher recording density is achieved in recording process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to magnetic recording, and more particularly, to a method and apparatus for magnetizing a magnetic disk surface for perpendicular magnetic recording in a hard disk drive assembly. About.

[0002]

2. Description of the Related Art Generally, a hard disk drive is used for storing electronic information. The information is recorded on concentric tracks on at least one surface of one or more magnetic recording disks. For convenience of storing and reproducing data in a regular manner, a magnetic disk is organized in blocks called sectors. These sectors are identified by cylinder (or track), head and sector number. These magnetic disks are rotatably mounted on a spin motor, and information is accessed by a recording / reproducing head. This head uses a voice coil motor (VC
M) is provided on the actuator arm that moves across the magnetic disk. The VCM is excited by an electric current to rotate the actuator and move the head.

A magnetic recording head has a magnetic resistance (magn).
eto-resistive (MR) and giant magneto-resistive
e; GMR) heads. Magnetoresistive (MR) head technology is magnetic random-access (mag)
This has been introduced to improve the recording and reproducing operations of a head used in a net-random-access storage assembly. The MR and GMR heads include a recording element for magnetizing a corresponding disk surface and another reproducing element for sensing a magnetic field of the corresponding magnetic disk. The head is connected to an electrical circuit that activates the recording element and senses the voltage across the reproducing element.

[0004] Generally, the recording element of the MR is made of a soft magnetic material.
And two magnetic poles. These two magnetic poles
Generally, it is connected to the end far away from the disk surface. The copper coil has a function of forming a magnetic field between the magnetic poles by supplying a current.

[0005] As a factor hindering the continuous progress of magnetic media data storage, the problem of the data density that can be realized on the storage medium is fundamental. Recently, an increase in data density has been realized. However, there is an increasing demand for increased data density in order to reduce power consumption and improve execution speed of components suitable for next-generation data storage equipment. Although the data density is affected by various factors, it has been erroneously considered that the design of the head assembly is the most important for increasing the data density. For example,
The increase in data density was realized with the introduction of the MR head. However, even if the dual structure of the recording / reproducing element is limited in data density, it may be caused by the inherent limitation of the degree of magnetic field change that it forms. Similarly, efforts to reduce the recording and playback elements have created marginal benefits, but inherent physical limitations have limited their benefits.

Generally, data is recorded in a sector by a vertical or horizontal magnetic recording system. In horizontal magnetic recording, the direction of magnetization is mainly formed in the same plane as that of the magnetized medium, whereas in perpendicular magnetic recording, the direction of magnetization is mainly formed perpendicular to the disk surface. Perpendicular magnetic recording is generally recognized as being superior to horizontal magnetic recording in that the opposite poles of the magnetized surface are arranged adjacent to each other to enhance the mutual magnetic polarity. I have. On the other hand, in horizontal magnetic recording, poles of the same magnetic direction are arranged adjacent to each other and only exert an effect of mutual element (demagnetization). Therefore, it is considered that high data density can be realized because perpendicular magnetic recording can generally form a small magnetization unit.

FIG. 10 shows that the conventional recording head 110 is
It is the perspective view shown on the YZ coordinate system. As shown in FIG. 10, the head has an upper pole 120 and a lower pole 140 which are formed across a magnetic field. Also,
The disk surface moves across the head in the X direction during the recording / reproducing operation. As is well known, one of the main limitations of conventional head design is that the trailing edge 130 produces a relatively low magnetic field change, especially in the case of perpendicular magnetic recording. As will be described later, the trailing edge 130 is important in that the lower the degree of change in the magnetic field, the lower the magnetization result and the lower the bit density.

In general, as the bit density increases, the bit pattern on the disk surface decreases. further,
Increasing the bit density reduces the signal perceived by the playback element. For this reason, conversely, several techniques have been applied to facilitate the function of enhancing the reduced signal. For example, attempts have been made to lift the recording / reproducing head close to the disk surface, or to add a winding (the number of windings of the copper wire wound on the magnetic core of the recording head). However, the lowering of the lift of the head lowers the stability of the system, and the addition of the winding increases the inductance of the head and lowers the speed of the recording operation.

FIG. 11 is a graph showing a tendency 200 of the degree of change in magnetic field with respect to the length of the conventional recording head 110.
In particular, this means that in the conventional perpendicular magnetic recording head, the disk surface is first magnetized on the read pole side 210 and then re-magnetized in the opposite field on the trailing pole side 220. 230 points are on the lead pole side 21
This corresponds to a peak magnetic field of 0. The 230 points occur mostly at the trailing end of the lead pole (ie, the side of the lead pole adjacent to the gap). Next, 240 points correspond to the peak magnetic field on the trailing pole side 220, and occur near the end of the trailing pole adjacent to the gap. Since the disk surface faces the lead pole, it is magnetized on the lead pole side 210 thereof.
Then, on the trailing pole side 220, it is magnetized again to a field of the opposite polarity. The 250 point is a magnetic transition point at which the disk surface is magnetized again. Incidentally, the gradient of the magnetic field change affects the ability of the recording head to proceed to the next recording operation, and a recording length corresponding to the gradient of the magnetic field change is required. In particular, the steeper the gradient of the magnetic field change along the trailing edge, the sooner the recording head can start the next recording operation. Accordingly, one aspect of the present invention is to reduce the required recording length by increasing the gradient of the magnetic field change along the trailing edge of the recording operation.

FIG. 12 shows a tendency 300 of a magnetic field change degree of the conventional recording head 110 as shown in FIG. The X axis in FIG. 12 corresponds to the position X in the length of the conventional recording head, where X = 0 is the front edge of the lower pole 140, and X = 6 is the upper pole 1
20 trailing edges. Line 310 indicates the degree of change in magnetic field when the conventional recording head 110 for performing perpendicular magnetic recording is applied. Line 320 indicates the degree of change in magnetic field applied to the conventional recording head 110 for performing horizontal magnetic recording. On the other hand, 330 points correspond to the magnetic field strength at the recording point of the trailing edge of the upper pole 120 during perpendicular magnetic recording. Next, 340 points correspond to the strength of the magnetic field at the recording point generated at the trailing edge of the head gap in horizontal magnetic recording. It is necessary to watch the residual magnetic field along the trailing edge of the recording head.

As shown in FIG. 12, the lower pole 140 corresponds to X = 0 to X = 3 microns. The gap between the lower pole 140 and the upper pole 120 is X = 3
To X = 3.15 microns, the upper pole 1
20 corresponds from X = 3.15 to X = 6.15 microns.

As described above, one of the conventional methods for increasing the bit density is to reduce the size of the recording head. Incidentally, the reducible length of the recording head is affected by the size of the formed bit pattern.

FIG. 13A shows a result of a bit pattern that appears when the width of the conventional recording head 110 is slightly larger than the limit value and narrow. This substantially horseshoe-shaped bit pattern adds additional noise during the reproduction process, which adversely affects the sensitivity of the reproduction head. Therefore, in order to avoid errors during the reproducing process, the width of the conventional recording head 110 needs to be kept slightly larger than a threshold value, that is, a value that limits the bit density that the recording head can generate.

FIG. 13B is a sectional side view of a bit pattern formed on a disk surface by a conventional recording head. In particular, FIG. 13B shows a vertical component of a bit pattern formed by a conventional recording head at a point where noise forming a substantially horseshoe-shaped bit pattern can be clearly confirmed.

[0015] In today's high quality systems, it is required that the input signal of the recorder be recorded and reproduced substantially without error (for example, when the number of lost data bits is 1).
× 10 ⁻⁶ or less). Therefore, it is highly desirable to have a linear recording density (bits per unit length) that multiplies the maximum possible area recording density (tracks per unit width). Similarly, the ratio to the number of data bits that can be read per unit time is preferably maximized.

[0016]

However, in the conventional method and apparatus for magnetizing a magnetic disk surface, if the recording head is reduced in order to realize a high bit density on the magnetic disk surface, for example, noise during reproduction is reduced. There is a problem that it has an adverse effect such as entering.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional method and apparatus for magnetizing a magnetic disk surface, and an object of the present invention is to provide a magnetic disk surface without adversely affecting reproduction time. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method and apparatus in which a higher bit density can be produced.

[0018]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a method for magnetizing a disk surface and a device such as a head, a recording head, and a hard disk.

First, according to a first aspect of the present invention, a head used for magnetization of a disk surface of a magnetic disk having a plurality of tracks includes recording means for forming a magnetic field in a direction substantially perpendicular to the disk surface. The recording means includes an upper pole and a lower pole, the upper pole having a first width and a second width smaller than the first width, wherein the second width is closer to the disk surface than the first width. To provide the head.

Further, the upper and lower poles are separated by a gap, and the upper and lower poles preferably form a magnetic field between the gaps.

Preferably, the upper pole includes a substantially concave portion and a substantially convex portion, and the substantially convex portion is adjacent to the gap and has a width substantially equal to the second width.

Preferably, the second width is not more than 0.6 microns.

Preferably, the substantially convex portion has a linear edge and a non-linear edge, wherein the linear edge is adjacent to the lower pole, and the non-linear edge is substantially parallel to the linear edge.

Preferably, the second width is between 0.2 and 0.6 microns.

Preferably, the generally recess has a depth of 0.6 to 1.0 microns.

The distance from the first width to the disk surface is the second
Preferably, it is 0.6 to 1.0 microns farther than the distance from the width to the disk surface.

According to a second aspect of the present invention, in a recording head for magnetizing a disk surface of a magnetic disk in a hard disk drive, an upper portion having a first width and a second upper portion having a smaller width than the first width. An upper pole having a width and a lower portion forming a pole tip; a magnetic field separated from the upper pole, having a direction substantially parallel to the upper pole, and substantially perpendicular to a disk surface between the upper pole and the upper pole. And a lower pole forming a gap in which the recording head is formed.

[0028] Preferably, the second width is no greater than 0.6 microns.

It is preferable that the magnetic field is formed so as to have a high density as it approaches the pole tip.

Preferably, the second width is between 0.2 and 0.5 microns.

A magnetic gradient having a negative gradient is formed over the upper pole, the magnetic gradient acting as a magnetic field, with the negative gradient increasing as the second width decreases from 0.6 microns to 0.2 microns. Preferably,

According to a third aspect of the present invention, there is provided a method for magnetizing a disk surface of a magnetic disk in a hard disk drive, comprising: a head having a coil connected to a magnetic core having an upper pole and a lower pole. Moving the magnetic field to the tracks of the magnetic disk; exciting the coil to form a magnetic field across the gap between the upper and lower poles, the magnetic field being substantially perpendicular to the disk surface, and the gap being equal to the upper and lower poles. A distance between the poles, wherein the upper pole has a first width and a second width, wherein the second width is adjacent to the gap and the disk surface and is smaller than the first width. And exposing the disk surface to a magnetic field over a recording length. The method for magnetizing a magnetic disk surface is provided.

In the step of energizing the coil to form a magnetic field between the upper pole and the lower pole, the second width is equal to 0.1.
Preferably it is less than 6 microns.

In the step of energizing the coil to form a magnetic field between the upper pole and the lower pole, the second width is equal to 0.1.
It is preferable to form a substantially convex portion having a width of 2 to 0.6 microns.

In the step of exciting the coil to form a magnetic field between the upper pole and the lower pole, the distance from the first width to the disk surface is 0.6 to 1.0.times. Greater than the distance from the second width to the disk surface. Preferably, it is as far as 0 microns.

Forming a magnetic gradient having a negative gradient over the upper pole, the magnetic gradient having the function of a magnetic field, and as the second width decreases from 0.6 microns to 0.2 microns, Preferably, the slope is even greater.

Preferably, the recording length decreases as the second width decreases from 0.6 microns to 0.2 microns.

Next, according to a fourth aspect of the present invention, a magnetic disk mounted on a housing, an actuator arm, a spin motor and having a plurality of tracks including data, and mounted on the actuator arm, A head having an upper pole and a lower pole, wherein the upper pole has an upper portion having a first width and a pole tip having a second width smaller than the first width; And a controller connected to the head for controlling recording and reproduction of data on the track.

The upper pole and the lower pole are separated by a gap, a magnetic field is formed in the gap between the upper pole and the lower pole, and the second width of the upper pole is preferably 0.6 μm or less.

The distance from the upper part to the magnetic disk is
0.6 from the distance from the pole tip to the magnetic disk
Preferably it is ~ 1.0 micron.

According to a fifth aspect of the present invention, there is provided a method of magnetizing a magnetic disk surface of a magnetic disk in a hard disk drive, wherein the magnetic disk surface is connected to a magnetic core having an upper pole and a lower pole. T
Moving the head with the coil to the track of the magnetic disk; exciting the coil to form a magnetic field across the gap between the upper and lower poles, the magnetic field being substantially perpendicular to the disk surface and the gap being A separated distance between the upper pole and the lower pole, the upper pole having an upper portion having a first width and a pole tip having a second width, wherein the pole tip is adjacent to the gap and the disk surface; A method of magnetizing a magnetic disk surface, comprising: a step of exposing the disk surface to a magnetic field over a recording length, wherein the width is smaller than the first width.

Preferably, the recording length is reduced by reducing the second width of the upper pole to between 0.2 and 0.6 microns.

According to a sixth aspect of the present invention, in a head used for magnetizing a disk surface of a magnetic disk having a plurality of tracks, a recording means for forming a magnetic field in a direction substantially perpendicular to the disk surface is provided. And a recording means including an upper pole and a lower pole, wherein the upper pole includes a substantially concave portion and a substantially convex portion.

The upper and lower poles are separated by a gap, and the upper and lower poles preferably form a magnetic field between the gaps.

Preferably, the substantially convex portion is adjacent to the gap.

Preferably, the substantially convex portion has a width of 0.6 microns or less.

Preferably, the substantially convex portion has a linear edge and a non-linear edge, wherein the linear edge is adjacent to the lower pole, and the non-linear edge is substantially parallel to the linear edge.

It is preferable that the substantially convex portion is 0.2 to 0.6 microns.

Preferably, the generally recess has a depth of 0.6 to 1.0 microns.

It is preferable that the distance from the substantially concave portion to the disk surface is 0.6 to 1.0 microns farther than the distance from the substantially convex portion to the disk surface. Subsequently, according to a seventh aspect of the present invention, there is provided a method for magnetizing a disk surface of a magnetic disk in a hard disk drive, comprising the steps of: And exciting the coil to form a magnetic field across the gap between the upper and lower poles, the magnetic field being substantially perpendicular to the disk surface and the gap being separated between the upper and lower poles. The upper pole has a substantially concave portion and a substantially convex portion adjacent to the gap; and exposing the disk surface to a magnetic field over the recording length. A method for magnetizing a disk surface is provided.

In the step of exciting the coil to form a magnetic field between the upper pole and the lower pole, the substantially convex portion is 0.6
Preferably it is less than a micron.

In the step of exciting the coil to form a magnetic field between the upper pole and the lower pole, the substantially convex portion has a height of 0.2 mm.
Preferably it has a width of ~ 0.6 microns.

In the step of exciting the coil to form a magnetic field between the upper pole and the lower pole, a substantially concave portion is formed.
Preferably it has a depth of between micron and 1.0 micron.

Forming a magnetic gradient having a magnitude, wherein the magnetic gradient has the function of a magnetic field;
It is preferable that the width of the substantially convex portion changes in inverse proportion to the width of the convex portion which varies between 0.6 μm and 0.6 μm.

It is preferable that the recording length be reduced as the width of the substantially convex portion decreases from 0.6 μm to 0.2 μm.

The apparatus includes a head used to magnetize a disk surface having a plurality of tracks, and recording means for generating a magnetic field substantially perpendicular to the disk surface, the recording means including an upper pole and a lower pole. , The upper pole has a first width and a second width smaller than the first width, and the second width is closer to the disk surface than the first width. Preferably, the second width is 0.6 microns or less.

The present invention provides a method for increasing the recording density on a magnetic disk of a hard disk drive by deforming the recording head, and an apparatus such as a head, a storage head, and a hard disk. The recording density used here refers to the number of data bits per unit area on the disk surface. Accordingly, one aspect of the present invention seeks to modify the trailing edge of the upper pole of the recording head so as to change the gradient of the magnetic field change applied to the trailing edge of the recording head to match. is there. Such a change in the shape of the degree of change in the magnetic field directly contributes to a reduction in the recording length required for magnetization,
High recording density can be achieved. Preferably, a concave area is introduced at the trailing edge of the upper pole of the recording head. The recess in the trailing edge can have a variety of shapes, but is generally part of the top pole edge so that the cross section of the top pole adjacent to the disk surface does not exceed 0.6 microns. Removing.
For example, the substantially concave portion of the upper pole is formed in a focused ion beam process.
s). Further, for example, the modified recording head is used in a perpendicular magnetic recording process of a hard disk drive assembly. Finally, here the upper pole is often referred to as the trailing pole and the lower pole as the leading pole.

[0058]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition,
In the specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a plan view of a hard disk drive 500 according to an embodiment of the present invention.

As shown in FIG. 1, the drive 500 includes at least one or more magnetic disks 502 rotated by a spindle motor 504. The drive 500 also includes a transducer 506 installed adjacent to the magnetic disk surface 508.

The transducer 506 is a magnetic disk 5
02, and by sensing its magnetic field,
Information can be recorded and reproduced on the rotating magnetic disk 502. Generally, there is one transducer 506 for each disk surface 508. Here, while one transducer 506 is shown and described, it should be understood that there is a recording transducer that magnetizes the magnetic disk 502 and a separate read transducer that senses the magnetic field of the magnetic disk 502.

The reproducing transducer is a magnetoresistive (MR)
Can be composed of materials. Some heads include a magnetoresistive (MR) material used to sense the magnetic field of the magnetic disk. The resistance of this magnetoresistive material changes linearly with changes in the magnetic field. The magnetoresistive material is connected to a power supply. A change in the magnetic field of the magnetic disk causes a corresponding change in the resistance of the magnetoresistive and a change in the voltage sensed across the magnetoresistive material. MR heads generally have higher recording densities than other types of disk drive heads.

The transducer 506 is the slider 5
10 is installed. The slider 510 is configured to form an air bearing between the transducer 506 and the disk surface 508. The slider 510
Is a head gimbal assembly
assembly (HGA) 512. The HGA 512 is installed on an actuator arm 514 having a voice coil 516. The voice coil 516 is disposed adjacent to the magnet assembly 518 to form a voice coil motor (VCM) 520. When current is supplied to the voice coil 516, the actuator arm 514 is connected to the bearing assembly 5.
A rotating torque is generated relative to 22. The rotation of the actuator arm 514 causes the transducer 50 to rotate.
6 can move across the disk surface 508.

Information is generally stored in an annular track 524 of the magnetic disk 502. Each track 524
Generally includes multiple sectors. Each sector includes a data field and a location information field. This position information field includes gray code information for identifying a sector and a track (cylinder). The above transducer 5
Reference numeral 06 records or reproduces information on a track while moving across the disk surface 508. Moving for access to another track is generally referred to as a seek route.

FIG. 2 is a schematic diagram of a system 600 that can control the hard disk drive 500 according to the present embodiment.

This system 600 has a playback / recording (R /
W) Channel circuit 604 and preamplifier circuit (pre-
The controller 6 connected to the transducer 506 by an amplifier circuit 610
02.

The controller 602 includes a digital signal processor (digital signal processor).
(DSP), a microprocessor, a microcontroller, or the like. The controller 602
The playback / recording channel 604 can read information from the magnetic disk 502 or provide a control signal to record information on the magnetic disk 502.

The above information is generally transferred from the R / W channel 604 to the host interface circuit 606. The host interface circuit 606 includes a control circuit and a buffer memory that enable the disk drive to interface with a system such as a personal computer.

The controller 602 includes a VCM driving circuit 608 for supplying a driving current to the voice coil 516.
Also connected. The controller 602 provides a control signal for controlling the movement of the transducer 506 by exciting the VCM to the drive circuit 608.

The controller 602 includes a nonvolatile memory such as a read only memory (ROM) and a flash memory 612 and a random access memory (RAM) 614.
Connected to. The memories 612 and 614 have instructions and data used by the controller 602 to execute software routines. These commands and data can be sorted and stored on the magnetic disk 502.
One of the software routines can be a search process to move the transducer 506 from one track to another. This search process may include a servo control process to ensure that the transducer 506 moves to the correct track.

FIG. 3 is a diagram showing a general sector layout of a magnetic disk of a hard disk drive.

As shown in FIG. 3, data is generally
It is stored in a sector of concentric tracks arranged in the radial direction of the magnetic disk 502. A general sector includes an automatic gain control (AGC) field 702, a tuning field 704, an index bit field 705 defining a sector, a gray code field 706 identifying a track, and a number of servo bits A, B, C. , D, and a data field 710 containing data. The sector may further include an error correction field (not shown). In operation, the head 110 moves to a certain track, reads the servo information provided in the servo field 708, and provides the servo information to the system 600.

FIG. 4 is a perspective view showing a recording head 800 according to the embodiment of the present invention. Like the conventional head as shown in FIG. 10, the recording head 800 according to the present embodiment as shown in FIG. 4 also includes an upper pole 820 and a lower pole 830. However, in the present embodiment, the upper pole 820 has the substantially concave portion 840 and the substantially convex portion 850.

The substantially concave portion 840 is formed by the upper pole 820.
Preferably at the trailing edge. Substantially concave 8
40 preferably has a depth of 0.6 to 1.0 microns in the Z-axis direction, which is a range in which saturation of magnetic flux density can be avoided.

The substantially convex portion 850 is located on the X axis (that is, on the X axis).
In FIG. 4, it has a predetermined width along the direction of the upper pole thickness). In the present embodiment, the substantially convex portion 850 is used.
Is preferably 0.2 to 0.6 microns in the X-axis direction. Specifically, it may be preferred that the width be about 0.2 microns, or even more preferable that the width be about 0.5 microns.

When the width of the above-mentioned substantially convex portion is reduced to 0.2 μm or less, the heat reduction effect becomes so remarkable that it cannot be ignored. Similarly, when the width of the substantially convex portion 850 reaches 0.6 μm,
The head 800 according to this embodiment is different from the conventional head 11.
It starts to return to a state showing zero magnetic field characteristics. Here, the substantially convex portion 850 is also called a pole tip.

One of the features of the embodiment of the present invention is as follows.
This is to reduce the magnetization length by introducing a substantially concave portion 840 into the upper pole 820. The term “magnetization length” as used herein refers to a length on the disk surface required for the recording head 800 to complete one recording operation and start a secondary recording operation. Since the magnetization length is inversely proportional to the bit density, shortening the magnetization length is an important factor in increasing the bit density.

FIG. 4 shows a substantially concave portion 84 according to this embodiment.
0, but the present invention is not limited to this example.
40 may have other shapes. As another shape, for example, there is a shape of a substantially concave portion 840 as shown in FIG. FIG. 5 is a perspective view showing the shape of an upper pole according to another embodiment. Each of the upper poles 820 has a substantially concave portion 8.
40 and a substantially convex portion 850 (that is, a pole tip). The upper pole 820 according to an embodiment of the present invention is a known technique using a focused ion beam.
On-beam (FIB) can be formed by a chamfering process.

FIG. 6 is a simplified sectional view of a recording head 1000 according to the embodiment of the present invention.

As shown in FIG. 6, the recording head 1000 according to the embodiment of the present invention has an upper pole 1010 provided with a pole tip. In addition, the upper pole 1010
Has an upper width 1050 that is wider than the lower width 1040. Further, the recording head 1000 includes the lower pole 102.
0 and a gap 1030 separating the upper pole 1010 and the lower pole 1020. In addition, the upper pole 1010 includes a substantially convex portion (that is, a pole tip) disposed adjacent to both the disk surface and the gap 1030. In this embodiment, the upper portion of the upper pole 1010 connected to the pole yoke 1060 has the width 1050 as described above. It should be noted that the length obtained by subtracting the width 1040 of the pole tip from the width 1050 of the upper portion of the upper pole is substantially the same as the width of the above-described recess in the direction along the trailing edge of the upper pole 1010. There is.

An arrow 1070 in FIG. 6 indicates a direction in which the disk surface moves across the recording head 1000 during a recording operation. Based on this direction, the lower pole 1020 becomes a leading pole and the upper pole 1010 becomes a trailing pole. Further, the recording head 1000 has copper coils 1080 _{1 to} 1080 _i for generating a magnetic field over the upper pole 1010 and the lower pole 1020.

In the embodiment of the present invention, as described with reference to FIGS. 13A and 13B, it is possible to avoid a substantially horseshoe-shaped bit pattern which is generated by various conventional recording heads and generates noise. .

FIG. 7 is a diagram showing a bit pattern formed by the recording head according to the present embodiment. The bit pattern 1110 in the present embodiment is not a substantially horseshoe shape as in a conventional bit pattern, but a substantially rectangular shape. Also, the cross section 1120 of the bit pattern formed on the disk surface has the same noise as the conventional case shown in FIG.

Next, FIG. 8 is a graph showing the tendency of the magnetic field change degree of the recording head according to the present embodiment. The intensity of the magnetic field shown in FIG.
The upper pole 820 is a micron, that is, the substantially convex portion 850 shown in FIG.
Is the case.

The X-axis in FIG. 8 corresponds to the position along the length of the recording head. Referring to FIG. 4, the position of X = 0 is the front edge of the lower pole 830 and the position of X = 6 is the upper pole 8.
20 trailing edges. Line 1210 indicates the degree of change in magnetic field over the magnetic head 800 according to the embodiment during perpendicular magnetic recording. On the other hand, line 1220 indicates the degree of change in the magnetic field over the magnetic head 800 during horizontal magnetic recording. Point 1230 is the upper pole 122 during perpendicular magnetic recording.
It corresponds to the strength of the magnetic field at the recording point of the trailing edge of 0. Point 1240 corresponds to the strength of the magnetic field at the recording point during horizontal magnetic recording that occurs at the trailing edge of the head gap.

In the recording head, the lower pole 830
Corresponds to the range of X = 0 to X = 3 microns on the X axis in FIG. Similarly, the gap between the lower pole 830 and the upper pole 820 is from X = 3 to X = 3.15 microns, and the upper pole is from X = 3.15 to X = 6.15 microns.
Equivalent to microns.

Next, comparing the tendency of the degree of change in the magnetic field of the recording head shown in FIGS. 12 and 8, particularly with respect to the perpendicular magnetic recording 1210, the configuration of the upper pole 820 according to the present embodiment in FIG. As compared with the configuration of the conventional upper pole 120, the characteristics of the degree of change in magnetic field are more excellent on the trailing side of the recording head.

Next, FIG. 9 is a graph showing a tendency of a magnetic field change degree formed by a plurality of recording heads according to the embodiment of the present invention.

The line 1310 corresponds to the conventional upper pole 1
20 corresponds to the magnetic flux density. Also, 1320
The line corresponds to the magnetic flux density generated by the recording head 820 having the substantially convex portion 850 having a width of 0.2 μm. Similarly, the width of the substantially convex portion 850 is 0.3 μm for 1330 lines, 0.4 μm for 1340 lines, and 135 μm.
In the case of the zero line, it is 0.5 microns.

As shown in FIG. 9, the correlation between the width of the substantially convex portion 850 in the upper pole 820 along the X-axis direction and the degree of change in the magnetic field is clear. In addition, the substantially convex portion 850
It can be seen that the width of the (ie, pole tip) not only changes the strength of the magnetic field applied to the recording head 800, but also affects the slope of the degree of change along the trailing edge of the head. In particular, the negative gradient of the degree of change in the magnetic field intensity increases as the size of the substantially convex portion decreases.

More specifically, the magnetic flux density increases as the width of the substantially convex portion 850 approaches 0.2 μm. In other words, this indicates that the recording head can record at a high bit density by shortening its length.

Further, the pole tip (ie, substantially convex portion)
As 850 approaches 0.6 microns, the degree of change in the magnetic field formed by the head approaches the pattern developed by the conventional recording head 110.

Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive various changes or modifications within the scope of the technical idea described in the claims, and those modifications naturally fall within the technical scope of the present invention. It is understood to belong.

[0094]

As described above, the method for magnetizing a magnetic disk surface and the apparatus such as a head, a recording head, and a hard disk according to the present invention provide an improved magnetic field change along a recording head by a substantially concave portion and a substantially convex portion. By forming the degree, a remarkably high recording density can be realized in the recording process without adversely affecting reproduction.

[Brief description of the drawings]

FIG. 1 is a plan view of a hard disk drive according to an embodiment.

FIG. 2 is a schematic diagram of a system for controlling a hard disk drive according to the embodiment;

FIG. 3 is a diagram showing a general sector layout of a magnetic disk of a hard disk drive.

FIG. 4 is a perspective view showing a recording head according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a shape of an upper pole according to another embodiment of the present invention.

FIG. 6 is a sectional view of a recording head according to an embodiment of the present invention.

FIG. 7 is a diagram showing a bit pattern formed by the recording head according to the embodiment of the present invention.

FIG. 8 is a graph of a magnetic field change degree of the recording head according to the embodiment of the present invention.

FIG. 9 is a graph showing a tendency of a plurality of magnetic field change degrees formed by the recording head according to the embodiment of the present invention.

FIG. 10 is a perspective view showing a conventional recording head.

FIG. 11 is a graph showing a tendency of a magnetic field change degree with respect to a conventional recording head length.

FIG. 12 is a graph showing a tendency of a magnetic field change degree of a conventional recording head.

FIG. 13A is a diagram showing a bit pattern formed by a conventional recording head. (B) One side sectional view of the bit pattern formed on the disk surface by the conventional recording head.

[Explanation of symbols]

 500 Hard disk drive 502 Magnetic disk 506 Transducer 600 System 602 Controller 800, 1000 Recording head 820, 1010 Upper pole 830, 1020 Lower pole 840 Substantially concave part 850 Substantially convex part 1110 Bit pattern

Continued on the front page F term (reference) 5D093 AA05 AE05 BB04 BB14 5D111 AA06 AA11 BB01 BB08 DD02 DD14 DD23 KK20

Claims (38)

[Claims] 1. A head used for magnetizing a disk surface of a magnetic disk having a plurality of tracks, comprising recording means for forming a magnetic field in a direction substantially perpendicular to the disk surface, wherein the recording means comprises an upper pole and a lower pole. Including
The head, wherein the upper pole has a first width and a second width smaller than the first width, wherein the second width is closer to the disk surface than the first width. 2. The head according to claim 1, wherein the upper and lower poles are separated by a gap, and the upper and lower poles form a magnetic field between the gaps. 3. The upper pole includes a substantially concave portion and a substantially convex portion, wherein the substantially convex portion is adjacent to the gap, and includes
3. The head according to claim 2, wherein the head has a width substantially equal to the width. 4. The head according to claim 1, wherein the second width is 0.6 μm or less. 5. The method of claim 1, wherein the substantially convex portion has a linear edge and a non-linear edge, the linear edge is adjacent to the lower pole, and the non-linear edge is substantially parallel to the linear edge. The head according to any one of 3 and 4, 6. The method of claim 1, wherein the second width is between 0.2 and 0.6 microns.
The head according to any one of the above. 7. The head according to claim 3, wherein the substantially concave portion has a depth of 0.6 to 1.0 μm. 8. The disk drive according to claim 1, wherein a distance from the first width to the disk surface is 0.6 to 1.0 microns longer than a distance from the second width to the disk surface. 8. The head according to any one of 2, 3, 4, 5, 6, and 7. 9. A recording head for magnetizing a disk surface of a magnetic disk in a hard disk drive, an upper portion having a first width and a lower portion having a second width smaller than said first width and forming a pole chip. An upper pole having a direction substantially parallel to the upper pole and forming a gap between the upper pole and the upper pole, the magnetic field being substantially perpendicular to the disk surface; A lower pole, which is provided. 10. The recording head according to claim 9, wherein the second width is 0.6 μm or less. 11. The recording head according to claim 9, wherein the magnetic field is formed so as to have a higher density as it approaches the pole tip. 12. The recording head according to claim 9, wherein said second width is 0.2 to 0.5 μm. 13. A magnetic gradient having a negative gradient over said upper pole is formed, said magnetic gradient acting as a magnetic field, and as said second width decreases from 0.6 microns to 0.2 microns. 13. The recording head according to claim 9, wherein the negative inclination is further increased. 14. A method of magnetizing a disk surface of a magnetic disk in a hard disk drive, comprising: moving a head having a coil connected to a magnetic core having an upper pole and a lower pole to a track of the magnetic disk; Exciting a coil to form a magnetic field across the gap between the upper pole and the lower pole, the magnetic field being substantially perpendicular to the disk surface;
The gap is a separated distance between the upper pole and the lower pole, the upper pole having a first width and a second width, wherein the second width is adjacent to the gap and the disk surface. And a step of exposing the disk surface to the magnetic field over a recording length, wherein the width is smaller than the first width. 15. The method of claim 14, wherein the step of energizing the coil to form the magnetic field between the upper pole and the lower pole has a width less than 0.6 microns. 3. The method for magnetizing a magnetic disk surface according to item 1. 16. A step of exciting the coil to form a magnetic field between the upper pole and the lower pole, wherein the second width forms a substantially convex portion having a width of 0.2 to 0.6 microns. 16. The method of magnetizing a magnetic disk surface according to claim 14, wherein: 17. A step of exciting the coil to form a magnetic field between the upper pole and the lower pole, wherein a distance from the first width to the disk surface is a distance from the second width to the disk surface. 16. The method of claim 14, 15, or 1 wherein the distance is 0.6-1.0 microns.
7. The method for magnetizing a magnetic disk surface according to any one of 6. 18. The method according to claim 18, further comprising the step of forming a magnetic gradient having a negative gradient across the upper pole, the magnetic gradient having a function of a magnetic field, wherein the second width is from 0.6 microns to 0.2 μm.
18. The method of magnetizing a magnetic disk surface according to claim 14, wherein the negative slope increases as the diameter decreases to 2 microns. 19. The recording length is such that the second width is 0.6.
18. The method as claimed in claim 14, wherein the length decreases as the diameter decreases from 0.2 microns to 0.2 microns.
Or a method for magnetizing a magnetic disk surface according to any one of the above items 18. 20. A magnetic disk installed on a housing, an actuator arm, and a spin motor and having a plurality of tracks including data, and a magnetic disk installed on the actuator arm and forming a magnetic field in a direction substantially perpendicular to the magnetic disk. A head having an upper portion having a first width and a pole tip having a second width smaller than the first width, the upper pole being connected to the head; A controller for controlling recording and reproduction of the data on a track. 21. The upper and lower poles are separated by a gap, a magnetic field is formed in the gap between the upper and lower poles, and the second width of the upper pole is less than 0.6 microns. 21. The hard disk drive according to claim 20, wherein: 22. The magnetic disk drive as claimed in claim 20, wherein a distance from the upper part to the magnetic disk is 0.6 to 1.0 μm longer than a distance from the pole tip to the magnetic disk. Hard disk drive according to any of the above. 23. A method of magnetizing a magnetic disk surface of a magnetic disk in a hard disk drive, comprising: connecting a head having a coil, connected to a magnetic core having an upper pole and a lower pole, to a track of the magnetic disk. Moving; exciting the coil to form a magnetic field across a gap between the upper pole and the lower pole, the magnetic field being substantially perpendicular to the disk surface; An upper pole having an upper portion having a first width and a pole tip having a second width, wherein the pole tip is adjacent to the gap and the disk surface; Wherein the second width is smaller than the first width; and Exposing the magnetic disk surface to the magnetic field. 24. The method according to claim 24, wherein the second width of the upper pole is 0.2.
24. The method as claimed in claim 23, wherein the recording length is shortened by narrowing the recording length to 0.6 microns. 25. A head used for magnetizing a disk surface of a magnetic disk having a plurality of tracks, comprising recording means for forming a magnetic field in a direction substantially perpendicular to the disk surface, wherein the recording means comprises an upper pole and a lower pole. Including
The upper pole includes a substantially concave portion and a substantially convex portion. 26. The head according to claim 25, wherein the upper and lower poles are separated by a gap, and the upper and lower poles form a magnetic field between the gaps. 27. The head according to claim 26, wherein the substantially convex portion is adjacent to the gap. 28. The method according to claim 25, wherein the substantially convex portion has a width of 0.6 μm or less.
7. The head according to any one of items 7. 29. The method of claim 29, wherein the substantially convex portion has a linear edge and a non-linear edge, the linear edge is adjacent to the lower pole, and the non-linear edge is substantially parallel to the linear edge. 25, 26, 27 or 28
The head according to any one of the above. 30. The method according to claim 25, wherein the substantially convex portion has a diameter of 0.2 to 0.6 μm.
30. The head according to any of 8 or 29. 31. The method according to claim 25, wherein the substantially concave portion has a depth of 0.6 to 1.0 microns.
The head according to any one of 27, 28, 29 and 30. 32. The disk drive according to claim 25, wherein a distance from said substantially concave portion to said disk surface is 0.6 to 1.0 microns longer than a distance from said substantially convex portion to said disk surface. The head according to any one of 27, 28, 29, 30, and 31. 33. A method of magnetizing a disk surface of a magnetic disk in a hard disk drive, comprising: moving a head having a coil connected to a magnetic core having an upper pole and a lower pole to a track of the magnetic disk; Exciting a coil to form a magnetic field across a gap between the upper pole and the lower pole, the magnetic field being substantially perpendicular to the disk surface;
Wherein the gap is a separated distance between the upper pole and the lower pole, and the upper pole has a substantially concave portion and a substantially convex portion adjacent to the gap; Exposing the magnetic disk surface to the magnetic field. 34. The method according to claim 33, wherein the step of exciting the coil to form a magnetic field between the upper pole and the lower pole has a thickness of about 0.6 μm or less. Method of magnetizing a magnetic disk surface. 35. The step of exciting the coil to form a magnetic field between the upper pole and the lower pole, wherein the substantially convex portion has a width of 0.2 to 0.6 microns. 35. The method for magnetizing a magnetic disk surface according to claim 33. 36. The step of exciting the coil to form a magnetic field between the upper pole and the lower pole, wherein the substantially concave portion has a depth of 0.6 μm to 1.0 μm. Claim 33, 34 or 3
5. The method according to claim 5, wherein the surface of the magnetic disk is magnetized. 37. Forming a magnetic gradient having a magnitude, said magnetic gradient having the function of a magnetic field, wherein said magnitude varies between 0.2 and 0.6 microns. The method for magnetizing a magnetic disk surface according to any one of claims 33, 34, 35, and 36, wherein the width of the magnetic disk changes in inverse proportion to the width of the portion. 38. The recording method according to claim 33, wherein the recording length decreases as the width of the substantially convex portion decreases from 0.6 μm to 0.2 μm.
38. The method for magnetizing a magnetic disk surface according to any one of 5, 36 and 37.