U.S. patent application number 14/102442 was filed with the patent office on 2015-06-11 for perpendicular magnetic recording head having a trailing side taper angle which is less than a leading side taper angle.
This patent application is currently assigned to HGST NETHERLANDS B.V.. The applicant listed for this patent is HGST Netherlands B.V.. Invention is credited to Kazue Kudo, Hiromi Shiina, Shouji Tokutake, Yosuke Urakami.
Application Number | 20150162024 14/102442 |
Document ID | / |
Family ID | 53190724 |
Filed Date | 2015-06-11 |
United States Patent
Application |
20150162024 |
Kind Code |
A1 |
Kudo; Kazue ; et
al. |
June 11, 2015 |
PERPENDICULAR MAGNETIC RECORDING HEAD HAVING A TRAILING SIDE TAPER
ANGLE WHICH IS LESS THAN A LEADING SIDE TAPER ANGLE
Abstract
In one embodiment, a perpendicular magnetic recording head
includes a main pole configured to write data to a magnetic medium,
a leading-side magnetic shield positioned on a leading side of the
main pole in a down-track direction adjacent a media-facing surface
of the head, and a trailing-side magnetic shield positioned on a
trailing side of the main pole in the down-track direction adjacent
the media-facing surface of the head, wherein a trailing side taper
is provided on the trailing side of the main pole in the down-track
direction, wherein a leading shield taper is provided on a main
pole side of the leading-side magnetic shield, and wherein an angle
of the trailing side taper relative to a line extending along an
element height direction is less than or equal to an angle of the
leading shield taper relative to the line extending along the
element height direction.
Inventors: |
Kudo; Kazue; (Odawara-shi,
JP) ; Shiina; Hiromi; (Hitachi-shi, JP) ;
Tokutake; Shouji; (Odawara-shi, JP) ; Urakami;
Yosuke; (Odawara-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HGST Netherlands B.V. |
Amsterdam |
|
NL |
|
|
Assignee: |
HGST NETHERLANDS B.V.
Amsterdam
NL
|
Family ID: |
53190724 |
Appl. No.: |
14/102442 |
Filed: |
December 10, 2013 |
Current U.S.
Class: |
360/75 ;
204/192.2; 360/125.03 |
Current CPC
Class: |
G11B 5/3116 20130101;
C23C 14/35 20130101; G11B 5/39 20130101; G11B 5/11 20130101 |
International
Class: |
G11B 5/11 20060101
G11B005/11; C23C 14/35 20060101 C23C014/35 |
Claims
1. A perpendicular magnetic recording head, comprising: a main pole
configured to write data to a magnetic medium, wherein a leading
pole taper is provided on a leading side of the main pole; a
leading-side magnetic shield positioned on a leading side of the
main pole in a down-track direction adjacent a media-facing surface
of the perpendicular magnetic recording head; and a trailing-side
magnetic shield positioned on a trailing side of the main pole in
the down-track direction adjacent the media-facing surface of the
perpendicular magnetic recording head, wherein a trailing side
taper is provided on the trailing side of the main pole in the
down-track direction, wherein a leading shield taper is provided on
a main pole side of the leading-side magnetic shield, and wherein
an angle of the trailing side taper relative to a line extending
along an element height direction is less than or equal to an angle
of the leading shield taper relative to the line extending along
the element height direction, wherein a step is provided on the
leading side of the main pole at an end of the leading pole taper
in the element height direction, the step increasing a thickness of
the main pole in the down-track direction.
2. The perpendicular magnetic recording head as recited in claim 1,
further comprising a non-magnetic bump positioned between the
trailing side of the main pole and a leading side of the
trailing-side magnetic shield at a position away from the
media-facing surface of the perpendicular magnetic recording
head.
3. The perpendicular magnetic recording head as recited in claim 1,
wherein a leading pole taper angle of the leading pole taper
relative to the line extending along the element height direction
is constant.
4. The perpendicular magnetic recording head as recited in claim 3,
wherein the leading pole taper angle is in a range between about
30.degree. and about 60.degree..
5. The perpendicular magnetic recording head as recited in claim 1,
wherein a height in the element height direction of the leading
pole taper from the media-facing surface of the perpendicular
magnetic recording head is greater than or equal to a height in the
element height direction of the leading-side magnetic shield from
the media-facing surface of the perpendicular magnetic recording
head.
6. The perpendicular magnetic recording head as recited in claim 2,
wherein some or all of the trailing side taper is provided by the
non-magnetic bump.
7. The perpendicular magnetic recording head as recited in claim 1,
wherein the step has a concave cross-sectional shape when viewed
from the media-facing surface of the perpendicular magnetic
recording head.
8. The perpendicular magnetic recording head as recited in claim 1,
wherein a trailing side taper angle of the trailing side taper
relative to the line extending along the element height direction
is in a range between about 5.degree. and about 30.degree..
9. (canceled)
10. The perpendicular magnetic recording head as recited in claim
21, wherein some or all of the trailing side taper is provided by
the non-magnetic bump.
11. The perpendicular magnetic recording head as recited in claim
1, wherein a height in the element height direction of the trailing
side taper is less than or equal to a height of the trailing-side
magnetic shield in the element height direction from the
media-facing surface of the perpendicular magnetic recording
head.
12. The perpendicular magnetic recording head as recited in claim
1, further comprising a side magnetic shield positioned on both
sides of the main pole in a cross-track direction, wherein at least
one of the side magnetic shield and the leading-side magnetic
shield comprises a multi-layered structure.
13. A magnetic data storage system, comprising: at least one
perpendicular magnetic recording head as recited in claim 1; a
magnetic medium; a drive mechanism for passing the magnetic medium
over the at least one perpendicular magnetic recording head; and a
controller electrically coupled to the at least one perpendicular
magnetic recording head for controlling operation of the at least
one perpendicular magnetic recording head.
14. A method for forming a perpendicular magnetic recording head,
the method comprising: forming a leading-side magnetic shield;
forming a leading shield taper on an upper side of the leading-side
magnetic shield, the leading shield taper being located at a
position along the upper side of the leading-side magnetic shield
away from a media-facing surface of the perpendicular magnetic
recording head in an element height direction such that the leading
shield is not tapered at the media-facing surface of the
perpendicular magnetic recording head; forming a main pole above
the leading-side magnetic shield, wherein the leading-side magnetic
shield is positioned below a leading side of the main pole in a
down-track direction adjacent the media-facing surface of the
perpendicular magnetic recording head; forming a trailing side
taper on a trailing side of the main pole in the down-track
direction; and forming a trailing-side magnetic shield above a
trailing side of the main pole in the down-track direction adjacent
the media-facing surface of the perpendicular magnetic recording
head, wherein an angle of the trailing side taper relative to a
line extending along the element height direction is less than or
equal to an angle of the leading shield taper relative to the line
extending along the element height direction.
15. The method as recited in claim 14, further comprising forming a
leading pole taper on a leading side of the main pole, wherein a
leading pole taper angle of the leading pole taper relative to the
line extending along the element height direction is constant, and
wherein the leading pole taper angle is in a range between about
30.degree. and about 60.degree..
16. The method as recited in claim 15, wherein a height in the
element height direction of the leading pole taper from the
media-facing surface of the perpendicular magnetic recording head
is greater than or equal to a height in the element height
direction of the leading-side magnetic shield from the media-facing
surface of the perpendicular magnetic recording head.
17. The method as recited in claim 14, wherein a trailing side
taper angle of the trailing side taper relative to the line
extending along the element height direction is in a range between
about 5.degree. and about 30.degree..
18. The method as recited in claim 17, further comprising forming a
non-magnetic bump between the trailing side of the main pole and a
leading side of the trailing shield at a position away from the
media-facing surface of the perpendicular magnetic recording head,
wherein some or all of the trailing side taper is provided by the
non-magnetic bump.
19. The method as recited in claim 14, wherein a height in the
element height direction of the trailing side taper is less than or
equal to a height of the trailing-side magnetic shield in the
element height direction from the media-facing surface of the
perpendicular magnetic recording head.
20. The method as recited in claim 15, further comprising forming a
step on the leading side of the main pole at an end of the leading
pole taper in the element height direction, the step increasing a
thickness of the main pole in the down-track direction.
21. A perpendicular magnetic recording head, comprising: a main
pole configured to write data to a magnetic medium; a leading-side
magnetic shield positioned on a leading side of the main pole in a
down-track direction adjacent a media-facing surface of the
perpendicular magnetic recording head; a trailing-side magnetic
shield positioned on a trailing side of the main pole in the
down-track direction adjacent the media-facing surface of the
perpendicular magnetic recording head; and a non-magnetic bump
positioned between the trailing side of the main pole and a leading
side of the trailing-side magnetic shield at a position away from
the media-facing surface of the perpendicular magnetic recording
head, wherein a trailing side taper is provided on the trailing
side of the main pole in the down-track direction, wherein a
leading pole taper is provided on a leading side of the main pole,
wherein a leading shield taper is provided on a main pole side of
the leading-side magnetic shield, and wherein an angle of the
trailing side taper relative to a line extending along an element
height direction is less than or equal to an angle of the leading
shield taper relative to the line extending along the element
height direction.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to perpendicular magnetic
recording heads, and more particularly, this invention relates to a
perpendicular magnetic recording head having a structure with a
trailing side taper angle which is less than a leading side taper
angle.
BACKGROUND
[0002] The heart of a computer is a magnetic hard disk drive (HDD)
which typically includes a rotating magnetic disk, a slider that
has read and write heads, a suspension arm above the rotating disk
and an actuator arm that swings the suspension arm to place the
read and/or write heads over selected circular tracks on the
rotating disk. The suspension arm biases the slider into contact
with the surface of the disk when the disk is not rotating but,
when the disk rotates, air is swirled by the rotating disk adjacent
an air bearing surface (ABS) of the slider causing the slider to
ride on an air bearing a slight distance from the surface of the
rotating disk. When the slider rides on the air bearing the write
and read heads are employed for writing magnetic impressions to and
reading magnetic signal fields from the rotating disk. The read and
write heads are connected to processing circuitry that operates
according to a computer program to implement the writing and
reading functions.
[0003] The volume of information processing in the information age
is increasing rapidly. In particular, HDDs have been desired to
store more information in its limited area and volume. A technical
approach to this desire is to increase the capacity by increasing
the recording density of the HDD. To achieve higher recording
density, further miniaturization of recording bits is effective,
which in turn typically requires the design of smaller and smaller
components.
[0004] High recording performance, high reliability, and low
manufacturing cost are extremely useful attributes for magnetic
recording heads used in HDDs. Japanese Unexamined Patent
Application Publication No. 2008-300027 discloses a perpendicular
magnetic recording head that is able to provide these attributes.
The perpendicular magnetic recording head, according to this
publication, includes at least a main pole, a lower shield
positioned below the main pole, and side shields positioned on
sides thereof.
[0005] Recording reliability is obtained due to the shields being
disposed below and to the sides of the main pole which prevent
erroneous reading of adjacent or nearby tracks, such as erroneous
reading due to adjacent track interference (ATI), far track
interference (FTI), etc. High reliability is realized by increasing
the laminate of the magnetic body of the main pole.
[0006] It is well known that to produce magnetic heads at a low
cost depends greatly on the manufacturing method utilized. Low
manufacturing costs may be accomplished by embedding the main pole
in a groove produced via an etching process performed on an upper
surface of the lower shield. In order to perform this etching
process, U.S. Patent Application Publication Nos. 2011/0151279 and
2011/0134569 disclose a structure in which a taper is provided on a
trailing side and a leading side of the main pole in a down-track
direction.
[0007] However, even with this structure, there is concern that
erroneous reading of an adjacent track or nearby tracks due to ATI
or FTI may occur. Accordingly, a magnetic head which alleviates
these concerns would be very beneficial.
SUMMARY
[0008] In one embodiment, a perpendicular magnetic recording head
includes a main pole configured to write data to a magnetic medium,
a leading-side magnetic shield positioned on a leading side of the
main pole in a down-track direction adjacent a media-facing surface
of the perpendicular magnetic recording head, and a trailing-side
magnetic shield positioned on a trailing side of the main pole in
the down-track direction adjacent the media-facing surface of the
perpendicular magnetic recording head, wherein a trailing side
taper is provided on the trailing side of the main pole in the
down-track direction, wherein a leading shield taper is provided on
a main pole side of the leading-side magnetic shield, and wherein
an angle of the trailing side taper relative to a line extending
along an element height direction is less than or equal to an angle
of the leading shield taper relative to the line extending along
the element height direction.
[0009] In another embodiment, a method for forming a perpendicular
magnetic recording head includes forming a leading-side magnetic
shield, forming a leading shield taper on an upper side of the
leading-side magnetic shield, forming a main pole above the
leading-side magnetic shield, wherein the leading-side magnetic
shield is positioned above a leading side of the main pole in a
down-track direction adjacent a media-facing surface of the
perpendicular magnetic recording head, forming a trailing side
taper on a trailing side of the main pole in the down-track
direction, and forming a trailing-side magnetic shield above a
trailing side of the main pole in the down-track direction adjacent
the media-facing surface of the perpendicular magnetic recording
head, wherein an angle of the trailing side taper relative to a
line extending along an element height direction is less than or
equal to an angle of the leading shield taper relative to the line
extending along the element height direction.
[0010] Any of these embodiments may be implemented in a magnetic
data storage system such as a disk drive system, which may include
a magnetic head, a drive mechanism for passing a magnetic medium
(e.g., hard disk) over the magnetic head, and a controller
electrically coupled to the magnetic head.
[0011] Other aspects and advantages of the present invention will
become apparent from the following detailed description, which,
when taken in conjunction with the drawings, illustrate by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a fuller understanding of the nature and advantages of
the present invention, as well as the preferred mode of use,
reference should be made to the following detailed description read
in conjunction with the accompanying drawings.
[0013] FIG. 1 is a simplified drawing of a magnetic recording disk
drive system.
[0014] FIG. 2A is a schematic representation in section of a
recording medium utilizing a longitudinal recording format.
[0015] FIG. 2B is a schematic representation of a conventional
magnetic recording head and recording medium combination for
longitudinal recording as in FIG. 2A.
[0016] FIG. 2C is a magnetic recording medium utilizing a
perpendicular recording format.
[0017] FIG. 2D is a schematic representation of a recording head
and recording medium combination for perpendicular recording on one
side.
[0018] FIG. 2E is a schematic representation of a recording
apparatus adapted for recording separately on both sides of the
medium.
[0019] FIG. 3A is a cross-sectional view of one particular
embodiment of a perpendicular magnetic head with helical coils.
[0020] FIG. 3B is a cross-sectional view of one particular
embodiment of a piggyback magnetic head with helical coils.
[0021] FIG. 4A is a cross-sectional view of one particular
embodiment of a perpendicular magnetic head with looped coils.
[0022] FIG. 4B is a cross-sectional view of one particular
embodiment of a piggyback magnetic head with looped coils.
[0023] FIG. 5A shows a portion of a perpendicular magnetic
recording head according to one embodiment.
[0024] FIG. 5B shows a portion of a perpendicular magnetic
recording head according to another embodiment.
[0025] FIG. 6 shows a media-facing surface view of a portion of a
perpendicular magnetic recording head according to one
embodiment.
[0026] FIG. 7 shows an image of a manufactured perpendicular
magnetic recording head according to one embodiment.
[0027] FIG. 8 shows results of testing on a manufactured
perpendicular magnetic recording head according to one
embodiment.
[0028] FIG. 9 shows results of testing on a manufactured
perpendicular magnetic recording head according to one
embodiment.
[0029] FIG. 10 shows a flowchart of a method according to one
embodiment.
DETAILED DESCRIPTION
[0030] The following description is made for the purpose of
illustrating the general principles of the present invention and is
not meant to limit the inventive concepts claimed herein. Further,
particular features described herein can be used in combination
with other described features in each of the various possible
combinations and permutations.
[0031] Unless otherwise specifically defined herein, all terms are
to be given their broadest possible interpretation including
meanings implied from the specification as well as meanings
understood by those skilled in the art and/or as defined in
dictionaries, treatises, etc.
[0032] It must also be noted that, as used in the specification and
the appended claims, the singular forms "a," "an" and "the" include
plural referents unless otherwise specified.
[0033] The following description discloses several preferred
embodiments of disk-based storage systems and/or related systems
and methods, as well as operation and/or component parts
thereof.
[0034] Due to the concerns over adjacent track and nearby track
erroneous reading occurring due to adjacent track interference
(ATI) and/or far track interference (FTI) in conventional magnetic
heads which utilize a structure which includes a taper on a
trailing side and a leading side in a down-track direction of a
main pole, a perpendicular magnetic recording head as described
according to various embodiments herein, alleviate the adjacent
track and nearby track erroneous reading.
[0035] In one general embodiment, a perpendicular magnetic
recording head includes a main pole configured to write data to a
magnetic medium, a leading-side magnetic shield positioned on a
leading side of the main pole in a down-track direction adjacent a
media-facing surface of the perpendicular magnetic recording head,
and a trailing-side magnetic shield positioned on a trailing side
of the main pole in the down-track direction adjacent the
media-facing surface of the perpendicular magnetic recording head,
wherein a trailing side taper is provided on the trailing side of
the main pole in the down-track direction, wherein a leading shield
taper is provided on a main pole side of the leading-side magnetic
shield, and wherein an angle of the trailing side taper relative to
a line extending along an element height direction is less than or
equal to an angle of the leading shield taper relative to the line
extending along the element height direction.
[0036] In another general embodiment, a method for forming a
perpendicular magnetic recording head includes forming a
leading-side magnetic shield, forming a leading shield taper on an
upper side of the leading-side magnetic shield, forming a main pole
above the leading-side magnetic shield, wherein the leading-side
magnetic shield is positioned above a leading side of the main pole
in a down-track direction adjacent a media-facing surface of the
perpendicular magnetic recording head, forming a trailing side
taper on a trailing side of the main pole in the down-track
direction, and forming a trailing-side magnetic shield above a
trailing side of the main pole in the down-track direction adjacent
the media-facing surface of the perpendicular magnetic recording
head, wherein an angle of the trailing side taper relative to a
line extending along an element height direction is less than or
equal to an angle of the leading shield taper relative to the line
extending along the element height direction.
[0037] Referring now to FIG. 1, there is shown a disk drive 100 in
accordance with one embodiment of the present invention. As shown
in FIG. 1, at least one rotatable magnetic disk 112 is supported on
a spindle 114 and rotated by a drive mechanism, which may include a
disk drive motor 118. The magnetic recording on each disk is
typically in the form of an annular pattern of concentric data
tracks (not shown) on the disk 112.
[0038] At least one slider 113 is positioned near the disk 112,
each slider 113 supporting one or more magnetic read/write heads
121. As the disk rotates, slider 113 is moved radially in and out
over disk surface 122 so that heads 121 may access different tracks
of the disk where desired data are recorded and/or to be written.
Each slider 113 is attached to an actuator arm 119 by means of a
suspension 115. The suspension 115 provides a slight spring force
which biases slider 113 against the disk surface 122. Each actuator
arm 119 is attached to an actuator 127. The actuator 127 as shown
in FIG. 1 may be a voice coil motor (VCM). The VCM comprises a coil
movable within a fixed magnetic field, the direction and speed of
the coil movements being controlled by the motor current signals
supplied by controller 129.
[0039] During operation of the disk storage system, the rotation of
disk 112 generates an air bearing between slider 113 and disk
surface 122 which exerts an upward force or lift on the slider. The
air bearing thus counter-balances the slight spring force of
suspension 115 and supports slider 113 off and slightly above the
disk surface by a small, substantially constant spacing during
normal operation. Note that in some embodiments, the slider 113 may
slide along the disk surface 122.
[0040] The various components of the disk storage system are
controlled in operation by control signals generated by controller
129, such as access control signals and internal clock signals.
Typically, control unit 129 comprises logic control circuits,
storage (e.g., memory), and a microprocessor. The control unit 129
generates control signals to control various system operations such
as drive motor control signals on line 123 and head position and
seek control signals on line 128. The control signals on line 128
provide the desired current profiles to optimally move and position
slider 113 to the desired data track on disk 112. Read and write
signals are communicated to and from read/write heads 121 by way of
recording channel 125.
[0041] The above description of a typical magnetic disk storage
system, and the accompanying illustration of FIG. 1 is for
representation purposes only. It should be apparent that disk
storage systems may contain a large number of disks and actuators,
and each actuator may support a number of sliders.
[0042] An interface may also be provided for communication between
the disk drive and a host (integral or external) to send and
receive the data and for controlling the operation of the disk
drive and communicating the status of the disk drive to the host,
all as will be understood by those of skill in the art.
[0043] In a typical head, an inductive write head includes a coil
layer embedded in one or more insulation layers (insulation stack),
the insulation stack being located between first and second pole
piece layers. A gap is formed between the first and second pole
piece layers by a gap layer at an air bearing surface (ABS) of the
write head. The pole piece layers may be connected at a back gap.
Currents are conducted through the coil layer, which produce
magnetic fields in the pole pieces. The magnetic fields fringe
across the gap at the ABS for the purpose of writing bits of
magnetic field information in tracks on moving media, such as in
circular tracks on a rotating magnetic disk.
[0044] The second pole piece layer has a pole tip portion which
extends from the ABS to a flare point and a yoke portion which
extends from the flare point to the back gap. The flare point is
where the second pole piece begins to widen (flare) to form the
yoke. The placement of the flare point directly affects the
magnitude of the magnetic field produced to write information on
the recording medium.
[0045] FIG. 2A illustrates, schematically, a conventional recording
medium such as used with magnetic disc recording systems, such as
that shown in FIG. 1. This medium is utilized for recording
magnetic impulses in or parallel to the plane of the medium itself.
The recording medium, a recording disc in this instance, comprises
basically a supporting substrate 200 of a suitable non-magnetic
material such as glass, with an overlying coating 202 of a suitable
and conventional magnetic layer.
[0046] FIG. 2B shows the operative relationship between a
conventional recording/playback head 204, which may preferably be a
thin film head, and a conventional recording medium, such as that
of FIG. 2A.
[0047] FIG. 2C illustrates, schematically, the orientation of
magnetic impulses substantially perpendicular to the surface of a
recording medium as used with magnetic disc recording systems, such
as that shown in FIG. 1. For such perpendicular recording the
medium typically includes an under layer 212 of a material having a
high magnetic permeability. This under layer 212 is then provided
with an overlying coating 214 of magnetic material preferably
having a high coercivity relative to the under layer 212.
[0048] FIG. 2D illustrates the operative relationship between a
perpendicular head 218 and a recording medium. The recording medium
illustrated in FIG. 2D includes both the high permeability under
layer 212 and the overlying coating 214 of magnetic material
described with respect to FIG. 2C above. However, both of these
layers 212 and 214 are shown applied to a suitable substrate 216.
Typically there is also an additional layer (not shown) called an
"exchange-break" layer or "interlayer" between layers 212 and
214.
[0049] In this structure, the magnetic lines of flux extending
between the poles of the perpendicular head 218 loop into and out
of the overlying coating 214 of the recording medium with the high
permeability under layer 212 of the recording medium causing the
lines of flux to pass through the overlying coating 214 in a
direction generally perpendicular to the surface of the medium to
record information in the overlying coating 214 of magnetic
material preferably having a high coercivity relative to the under
layer 212 in the form of magnetic impulses having their axes of
magnetization substantially perpendicular to the surface of the
medium. The flux is channeled by the soft underlying coating 212
back to the return layer (P1) of the head 218.
[0050] FIG. 2E illustrates a similar structure in which the
substrate 216 carries the layers 212 and 214 on each of its two
opposed sides, with suitable recording heads 218 positioned
adjacent the outer surface of the magnetic coating 214 on each side
of the medium, allowing for recording on each side of the
medium.
[0051] FIG. 3A is a cross-sectional view of a perpendicular
magnetic head. In FIG. 3A, helical coils 310 and 312 are used to
create magnetic flux in the stitch pole 308, which then delivers
that flux to the main pole 306. Coils 310 indicate coils extending
out from the page, while coils 312 indicate coils extending into
the page. Stitch pole 308 may be recessed from the ABS 318.
Insulation 316 surrounds the coils and may provide support for some
of the elements. The direction of the media travel, as indicated by
the arrow to the right of the structure, moves the media past the
lower return pole 314 first, then past the stitch pole 308, main
pole 306, trailing shield 304 which may be connected to the wrap
around shield (not shown), and finally past the upper return pole
302. Each of these components may have a portion in contact with
the ABS 318. The ABS 318 is indicated across the right side of the
structure.
[0052] Perpendicular writing is achieved by forcing flux through
the stitch pole 308 into the main pole 306 and then to the surface
of the disk positioned towards the ABS 318.
[0053] FIG. 3B illustrates a piggyback magnetic head having similar
features to the head of FIG. 3A. Two shields 304, 314 flank the
stitch pole 308 and main pole 306. Also sensor shields 322, 324 are
shown. The sensor 326 is typically positioned between the sensor
shields 322, 324.
[0054] FIG. 4A is a schematic diagram of one embodiment which uses
looped coils 410, sometimes referred to as a pancake configuration,
to provide flux to the stitch pole 408. The stitch pole then
provides this flux to the main pole 406. In this orientation, the
lower return pole is optional. Insulation 416 surrounds the coils
410, and may provide support for the stitch pole 408 and main pole
406. The stitch pole may be recessed from the ABS 418. The
direction of the media travel, as indicated by the arrow to the
right of the structure, moves the media past the stitch pole 408,
main pole 406, trailing shield 404 which may be connected to the
wrap around shield (not shown), and finally past the upper return
pole 402 (all of which may or may not have a portion in contact
with the ABS 418). The ABS 418 is indicated across the right side
of the structure. The trailing shield 404 may be in contact with
the main pole 406 in some embodiments.
[0055] FIG. 4B illustrates another type of piggyback magnetic head
having similar features to the head of FIG. 4A including a looped
coil 410, which wraps around to form a pancake coil. Also, sensor
shields 422, 424 are shown. The sensor 426 is typically positioned
between the sensor shields 422, 424.
[0056] In FIGS. 3B and 4B, an optional heater is shown near the
non-ABS side of the magnetic head. A heater (Heater) may also be
included in the magnetic heads shown in FIGS. 3A and 4A. The
position of this heater may vary based on design parameters such as
where the protrusion is desired, coefficients of thermal expansion
of the surrounding layers, etc.
[0057] In order to combat ATI and FTI in a magnetic recording head,
the laminate of the magnetic body on a media-facing side of the
main pole may be increased. Furthermore, a taper is provided on a
trailing side and a leading side of a down-track direction of the
main pole, and in particular a taper angle of the leading side
where the geometric width is narrow may be about 30.degree. or more
and about 60.degree. or less.
[0058] By making a length of the leading side taper in a specific
range, for example, between about 300 nm and about 450 nm, a
configuration is provided in which there is an area with a thick
film (magnetic body) on the leading side of the main pole (a
thickness of the main pole at the rear end portion may be longer,
for example, about 500 nm). In addition, erroneous reading from
adjacent or nearby tracks due to ATI or FTI, etc., is prevented
using the above described structure.
[0059] The taper angle of the trailing side where the geometric
width is wider may be less than the taper angle of the leading side
taper. In other words, the taper angle may be set to about
5.degree. or more and about 30.degree. or less. In this structure
magnetic flux on the trailing side is controlled, which prevents
oversaturation of an adjacent shield.
[0060] Furthermore, a non-magnetic bump may be provided between the
main pole and the shields, and a taper angle is formed on the
shield side of the bump; in particular, by maintaining the taper
angle of the trailing side, a linear rear surface is formed on the
shield. Also, by making the taper length 350 nm or longer, for
example, a structure is obtained in which even if the taper is set
small, the distance between the main pole and the adjacent shield
is 100 nm or more. As a result of this configuration, a
perpendicular magnetic recording head according to one embodiment
is provided with a trailing side taper angle that is less than a
leading side taper angle.
[0061] Now referring to FIGS. 5A-5B, portions of two perpendicular
magnetic recording heads 500, 550, respectively, are shown
according to two embodiments. Each perpendicular magnetic recording
head 500, 550 includes a main pole 502, a trailing-side magnetic
shield 504 on a trailing side of the main pole 502, a leading-side
magnetic shield 506 on a leading side of the main pole 502, and a
non-magnetic insulating layer 522 positioned between the main pole
502 and the leading-side magnetic shield 506. Each of these layers
has a portion thereof which is positioned adjacent a media-facing
surface 530 of the perpendicular magnetic recording head 500,
550.
[0062] In some embodiments, a slider substrate 524 or some other
substrate or base layer may be positioned below portions of the
insulating layer 522 and the leading-side magnetic shield 506. For
each perpendicular magnetic recording head 500, 550, a trailing
side taper 508 is provided on the leading side of the trailing-side
magnetic shield 504 in a down-track direction 526 relative to a
trailing side of the main pole 502 and/or a trailing side of a
non-magnetic bump 514, which begins at a position away from the
media-facing surface 530 in the element height direction 528. Also,
a leading shield taper 510 is provided on a main pole-facing side
of the leading-side magnetic shield 506 in the down-track direction
526, which begins at a position away from the media-facing surface
530 in the element height direction 528. The position at which each
taper 508, 510 begins may be the same in the element height
direction 528 or different, according to various embodiments.
[0063] As shown in FIGS. 5A-5B, an asymmetric relationship may be
satisfied where a trailing side taper angle .beta. of the trailing
side taper 508, which may be an angle of taper for the
trailing-side magnetic shield 504, the non-magnetic bump 514,
and/or the trailing side of the main pole 502 (as shown in FIG.
5B), is less than or equal to a leading shield taper angle .alpha.
of the leading shield taper 510.
[0064] Due to the structures of each perpendicular magnetic
recording head 500, 550 it is possible to increase a thickness of
the magnetic body that forms the main pole 502 adjacent the
media-facing side of the main pole 502, and to prevent erroneous
reading of adjacent or nearby tracks due to ATI, FTI, etc.
[0065] Referring again to FIGS. 5A-5B, in another embodiment, a
leading pole taper 512 may be provided on the leading side of the
main pole 502 in the down-track direction 526. The leading pole
taper 512 has a leading pole taper angle .gamma. that may be more
than, equal to, or less than the leading shield taper angle
.alpha.. In one embodiment, the leading shield taper angle .alpha.
and/or the leading pole taper angle .gamma. may be in a range
between about 30.degree. and about 60.degree.. As shown in FIG. 8,
some experiments were carried out on this arrangement, and the
results are shown.
[0066] As shown in FIG. 5B, a constant leading shield taper angle
.alpha. may be used that is equal to the leading pole taper angle
.gamma. such that the distance between the leading-side magnetic
shield 506 and the main pole 502 may be maintained as a constant,
in one embodiment. In other embodiments, the leading shield taper
angle .alpha. may change along a line extending along the element
height direction 528 perpendicular to the media-facing surface 530
of the perpendicular magnetic recording head 500, which would
result in a non-constant distance between the leading-side magnetic
shield 506 and the main pole 502 in the down-track direction.
[0067] According to another embodiment, as shown in FIG. 5B, the
main pole 502 may have a trailing pole taper 516 on a trailing side
of the main pole 502 in the down-track direction 526. The trailing
pole taper 516 may have a trailing pole taper angle .delta. that is
in a range between about 5.degree. and about 30.degree.. This is in
order to ensure that the thickness of the main pole 502 at a
position beyond the tapering in the element height direction 528 is
sufficiently thick in the down-track direction 526, as would be
understood by one of skill in the art, to provide a sufficiently
strong magnetic field when energized. This results in a high
magnetic field being obtained due to the increase in the leading
pole taper angle .gamma.. With this structure, magnetic flux is
controlled on the trailing side of the main pole 502, which has the
effect of preventing oversaturation of the adjacent trailing-side
magnetic shield 504.
[0068] According to another embodiment, as shown in FIG. 5B, the
main pole 502 may have a trailing pole taper 516 on a trailing side
of the main pole 502 in the down-track direction 526. The trailing
pole taper 516 may have a trailing pole taper angle .delta. that is
in a range between about 5.degree. and about 30.degree.. In one
embodiment, the trailing pole taper angle .delta. may be about
equal to the trailing side taper angle .beta..
[0069] In another embodiment, the trailing side taper angle .beta.
may be in a range from about 5.degree. to about 30.degree.. As
shown in FIG. 9, performance of the perpendicular magnetic
recording head is greatest when the trailing side taper angle is
about 20.degree., but any value between about 5.degree. and about
30.degree. also produce great performance. Referring again to FIGS.
5A-5B, having the trailing side taper angle .beta. in this range
results in an improved slope of the track edge when the low angle
trailing side taper angle .beta. has sufficient strength with
respect to the medium.
[0070] For shingled magnetic recording (SMR) where width of the
main pole 502 is typically wider than in conventional recording and
may have a wide side gap and low bevel angle (about 20.degree. or
less), a trailing side taper angle .beta. of about 15.degree. or
more and about 20.degree. or less may be used, in one approach.
[0071] In another approach, each perpendicular magnetic recording
head 500, 550 may include a non-magnetic bump 514 that is
positioned between a trailing side of the main pole 502 and the
leading side of the trailing-side magnetic shield 504. Any suitable
material known in the art may be used for the non-magnetic bump
514, such as alumina (Al.sub.2O.sub.3), MgO, etc. In this approach,
the non-magnetic bump 514 may be positioned along all (as shown in
FIG. 5A) or only a part (as shown in FIG. 5B) of the trailing side
taper 508. In particular, by using a non-magnetic bump 514 that is
positioned along all of the trailing side taper 508, a linear rear
surface of the main pole 502 is possible, which reduces complexity
in manufacturing.
[0072] In another embodiment, a height H3 in the element height
direction 528 of the leading pole taper 512 of the main pole 502
may be determined by a height H4 in the element height direction of
the leading-side magnetic shield 506, such that the overall height
H3 of the leading pole taper 512 is less than or equal to an
overall height H4 (from the media-facing surface 530) of the
leading-side magnetic shield 506. This structure results in a
region with a thick film (magnetic body) on the leading side of the
main pole 502 (with a thickness of the main pole 502 at a position
beyond the tapering being between about 250 nm and about 1000 nm,
such as about 500 nm).
[0073] In another approach, a height H3 in the element height
direction 528 of the leading pole taper 512 from the media-facing
surface 530 may be greater than or equal to a height H4 in the
element height direction of the leading-side magnetic shield 506
from the media-facing surface 530.
[0074] In one approach, a height H2 of the trailing pole taper 516
in the element height direction 528 may be less than or equal to a
height H1 of the trailing-side magnetic shield 504 in the element
height direction 528. In this approach, even when a gentle taper is
used, the distance between the main pole 502 and the trailing-side
magnetic shield 504 may be 100 nm or more, as shown in FIG. 5B.
[0075] Referring again to FIGS. 5A-5B, according to another
embodiment, a step 518 may be provided on the leading side of the
main pole 502 at the end of the leading pole taper 512 in the
element height direction 528, the step increasing the thickness of
the main pole 502 in the down-track direction 526. As a result of
this step 518, the main pole 502 at a position beyond the tapering
may be substantially thicker than the main pole 502 adjacent the
media-facing surface 530 of the perpendicular magnetic recording
head 500, 550.
[0076] In a further embodiment, the step 518, which is located on
the leading side of the main pole 502 at the end of the leading
pole taper 512 in the element height direction 528, may be provided
with a concave shape when viewed from the media-facing side. This
concave shape may appear as shown in FIG. 7 in one embodiment.
[0077] In another embodiment, as shown in FIG. 6, a side magnetic
shield 520 may be provided on both sides of the main pole 502 in a
cross-track direction. In this embodiment, the side magnetic shield
520 and/or the leading-side magnetic shield 506 may have a
multi-layered structure, as indicated by the striation lines
running through the layers. In a further embodiment, the
leading-side magnetic shield 506 may comprise an antiferromagnetic
coupling multi-layered film, which has an effect of reducing FTI
further.
[0078] A method for forming a perpendicular magnetic head is now
described according to one embodiment. The method may be performed
in any desired environment, including those described herein and
others.
[0079] In this method, the leading-side magnetic shield is formed,
which may act as a base for the formation of other layers thereon,
such as in pattern plating or the like (in pattern plating, the
desired pattern is formed using a resist or the like, and a plating
film is formed within the pattern). The leading-side magnetic
shield may be formed above a substrate in one approach. The
leading-side magnetic shield may comprise NiFe, CoFe, or some other
suitable material known in the art.
[0080] Next, the substrate is removed by Ar ion milling, and an
alumina film, or the like, is formed by sputtering, or the like,
for planarization of the leading-side magnetic shield. Then,
planarization is carried out by chemical mechanical polishing (CMP)
or the like. Next, a hard mask is formed thereon using any suitable
material, for example NiCr/Ta, by sputtering or the like.
[0081] After the hard mask is formed, the resist is coated and the
shape of the main pole is patterned therein. After patterning, a
groove shape is formed in the shield film and the alumina film by
Ar ion milling, RIE, etc. At this time the leading-side magnetic
shield has a taper due to the difference in area of the aperture
and the difference in etching rate, thus causing an angle to be
formed.
[0082] Next, a non-magnetic film, such as alumina, is formed to a
desired film thickness as a side gap, wherein a thickness of the
non-magnetic film determines the thickness of the side gap. After
forming a plating underlayer, a resist is patterned thereon, and
the main pole is plated using the resist pattern.
[0083] After removing the resist, planarization is carried out,
such as via CMP, to adjust a thickness of the main pole. Then,
another non-magnetic film is formed over the whole surface, such as
by sputtering, a resist pattern is placed in desired positions to
form a desired pattern, Ar ion milling of the non-magnetic film and
the main pole is carried out, and a slope is formed on an upper
surface of the main pole. Then, after forming a magnetic gap film,
a substrate film is sputtered, and a soft magnetic film is formed
on the trailing side of the main pole to form the trailing-side
magnetic shield.
[0084] Any of the various layers and films described above may have
any suitable material utilized according to their individual
functions and/or purposes, as would be known to one of skill in the
art.
[0085] Now referring to FIG. 10, a method 1000 for forming a
perpendicular magnetic recording head is shown according to one
embodiment. Method 1000 may be performed in accordance with the
present invention in any of the environments depicted in FIGS. 1-9,
among others, in various embodiments. Of course, more or less
operations than those specifically described in FIG. 10 may be
included in method 1000, as would be understood by one of skill in
the art upon reading the present descriptions.
[0086] Each of the steps of the method 1000 may be performed by any
suitable component of the operating environment. As shown in FIG.
10, method 1000 may initiate with operation 1002, where a
leading-side magnetic shield is formed of any suitable material
known in the art. In operation 1004, a leading shield taper is
formed on an upper side of the leading-side magnetic shield, the
side which will eventually face the main pole.
[0087] In operation 1006, a main pole is formed above the
leading-side magnetic shield. The leading-side magnetic shield is
positioned above a leading side of the main pole in a down-track
direction adjacent a media-facing surface of the perpendicular
magnetic recording head. Any suitable formation technique and
material may be used for the main pole as would be known to one of
skill in the art.
[0088] In operation 1008, a trailing side taper is formed on a
trailing side of the main pole in the down-track direction.
[0089] In operation 1010, a trailing-side magnetic shield is formed
above a trailing side of the main pole in the down-track direction
adjacent the media-facing surface of the perpendicular magnetic
recording head. The trailing pole taper is less than or equal to
the leading shield taper.
[0090] In another embodiment, a leading pole taper may be formed on
a leading side of the main pole. A leading pole taper angle of the
leading pole taper relative to an element height direction may be
constant, with the leading pole taper angle being in a range
between about 30.degree. and about 60.degree..
[0091] According to another embodiment, a height in an element
height direction of the leading pole taper from the media-facing
surface of the perpendicular magnetic recording head may be greater
than or equal to a height in the element height direction of the
leading-side magnetic shield from the media-facing surface of the
perpendicular magnetic recording head.
[0092] Also, in some approaches, a trailing side taper angle of the
trailing side taper relative to an element height direction may be
in a range between about 5.degree. and about 30.degree..
[0093] In another embodiment, method 1000 may further include
forming a non-magnetic bump between the trailing side of the main
pole and a leading side of the trailing shield at a position away
from the media-facing surface of the perpendicular magnetic
recording head. In this embodiment, some or all of the trailing
side taper is provided by the non-magnetic bump.
[0094] According to another embodiment, a height in an element
height direction of the trailing side taper may be less than or
equal to a height of the trailing-side magnetic shield in the
element height direction from the media-facing surface of the
perpendicular magnetic recording head.
[0095] In another embodiment, a step may be formed on the leading
side of the main pole at an end of the leading pole taper in an
element height direction. The step increases a thickness of the
magnetic pole in the down-track direction.
[0096] While various embodiments have been described above, it
should be understood that they have been presented by way of
example only, and not limitation. Thus, the breadth and scope of an
embodiment of the present invention should not be limited by any of
the above-described exemplary embodiments, but should be defined
only in accordance with the following claims and their
equivalents.
* * * * *