Method of making integral transducer-suspension assemblies for longitudinal recording

An integral combination magnetic transducer and suspension assembly suitable for use in both contact recording and in winchester-type applications is described. A generally rectangular elongate flat suspension member includes a ring-type inductive read/write transducer formed integrally with the suspension member and is embedded in one end of the suspension member. The ring-type inductive transducer is suitable for horizontal recording applications. The transducer magnetic poletips and magnetic gap are formed and positioned such that the poletips and gap are essentially co-planar with the air bearing surface of a slider-shaped protrusion extending from the lower surface of the end of the suspension member adjacent a moving media during operation. The air bearing surface presented to the disk has most of its area covered with a wear layer to minimize wear of the slider surface and poletips.

CROSS-REFERENCE TO RELATED U.S. PATENTS 
Hinkel et al, U.S. Pat. No. 4,624,048, issued on Nov. 25, 1986 and assigned 
to the assignee of the present invention, to show a process for making 
magnetic head sliders useful with the present invention. 
Jacobs, U.S. Pat. No. 4,251,841, issued on Feb. 17, 1981 and assigned to 
the assignee of the present invention, to show a wafer-substrate material 
useful with the present invention. 
Cuzner, et al, U.S. Pat. No. 3,849,800, issued on Nov. 19, 1974 and 
assigned to the assignee of the present invention, to show a rotary 
actuator useful in a drive using the present invention. 
Watrous, U.S. Pat. No. 4,167,765, issued on Sep. 11, 1979 and assigned to 
the assignee of the present invention to show a suspension system useful 
with the present invention. 
The above U.S. patents are incorporated by reference herein. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to moving magnetic storage devices 
and their recording elements and more particularly to 
transducer-suspension structures which are suitable for batch fabrication 
and a method for making the structures. 
2. Description of the Related Art 
Moving magnetic storage devices, especially magnetic disk drives, are the 
memory device of choice. This is due to their expanded non-volatile memory 
storage capability together with a relatively low cost. Accurate retrieval 
of the stored memory from these devices becomes critical, requiring the 
magnetic transducer to be positioned as close to the media as possible. 
Optimally, the transducer should actually touch the media. 
Disk files are information storage devices which utilize at least one 
rotatable magnetic media disk with concentric data tracks containing data 
information, a read/write transducer for reading the data from or writing 
the data to the various tracks, a slider for holding the transducer 
adjacent to the track generally in a flying mode above the media, a 
suspension for resiliently holding the slider and the transducer over the 
data tracks, and a positioning actuator connected to the 
transducer/suspension combination for moving the transducer across the 
media to the desired data track and maintaining the transducer over the 
data track center line during a read or a write operation. The transducer 
is attached to the air bearing slider which supports the transducer above 
the track of the disk by a cushion of air that is generated by the 
rotating disk. Alternatively, the transducer may also operate in contact 
with the disk. The suspension provides desired slider loading and 
dimensional stability between the slider and the actuator arm. The 
suspension is required to maintain the transducer and the slider adjacent 
to the data surface of the disk with as low a loading force as possible. 
The actuator positions the transducer over the correct track according to 
the data desired on a read operation or to the correct track for placement 
of the data during a write operation. The actuator is controlled to 
position the transducer over the correct track by shifting the combination 
generally transverse to the direction along the track. 
In conventional disk drives, the transducer and the slider are formed 
separately from the suspension and then attached through a manual, 
operator controlled precision operation. Typically, these components are 
small and the positioning of each relative to the other must be exact. 
During operation, the transducer must be exactly positioned relative to 
the data track, which in turn means that the suspension must be exactly 
positioned onto the slider. The suspension must provide flexibility to 
pitch and roll motion for the slider relative to the direction of motion 
of the rotating disk and yet also provide resistance to yaw motion. Any 
error in the placement of the suspension relative to the slider may result 
in the destruction of both components. Even if the suspension and the 
slider are correctly positioned, electrical conductor leads to the 
transducer must then be connected to the transducer. The conductor leads 
are directed along the suspension and connected to an amplifier placed on 
the suspension or on the actuator. The conductor leads must not add to the 
spring stiffness of the slider while providing good electrical 
interconnection. The conductor leads are generally bonded by soldering or 
ultrasonic bonding, for example, to both the transducer output terminals 
and the amplifier by an operator. Again, errors can cause destruction of 
the entire combination. Touching the media presents unique problems in 
wear and, during operation of the disk file, the possibility of creating a 
"crash" of the media. To reduce the wear problem and "crash" potential, it 
has been recognized that the mass of the suspension system must be reduced 
to a minimum. Minimal mass optimizes any physical "impact" the head has 
upon the media and thereby reduces the possibility of damage and wear. 
To this end there have been disclosed a variety of mechanisms which utilize 
a "reed" approach to producing the transducer-slider-suspension. 
Structured to work in a perpendicular recording environment, these devices 
permit the head and suspension to be easily manufactured laving: (i) 
precise throat height control, (ii) precise formation of air bearings to 
achieve specified flying heights, (iii) bonding of sliders to suspensions, 
and, (iv) easy routing of conductor leads. 
U.S. Pat. Nos. 5,041,932; 5,073,242; and 5,111,351 entitled "Integrated 
Magnetic Read/Write Head/Flexure/Conductor Structure" granted to Harold J. 
Hamilton disclose an integral magnetic transducer/suspension/conductive 
structure having the form of an elongate dielectric flexure or suspension 
body with a magnetic read/write transducer embedded within at one end 
thereof. In a preferred embodiment, Hamilton discloses an elongate, 
dielectric flexure body of aluminum oxide having a magnetic pole structure 
and helical coil integrally formed at one end of the flexure body with 
embedded copper conductor leads running the length of the flexure body to 
provide electrical connection for the transducer. The integral structure 
is fabricated utilizing conventional vapor deposition and photolithography 
techniques. The integral transducer/suspension structure disclosed by 
Hamilton may be used in a contact recording system or in a system where 
the transducer flies above the storage medium on a cushion of air. 
As noted earlier, contact recording permits higher signals and greater 
resolution unregulated by variations in flying height. Unfortunately, the 
wear associated with contact recording is usually not acceptable. Still 
another disadvantage is the requirement, in a perpendicular head, of two 
perpendicular planes which create processing problems. All of this has 
made the prior art perpendicular recording head unsuitable for high 
density recording. 
SUMMARY OF THE INVENTION 
It is therefore a primary object of the present invention to provide an 
enhanced magnetic moving storage device having a head structure that 
includes an enhanced transducer configuration. 
It is another object of the present invention to create a head-suspension 
structure which is suitable for longitudinal recording. 
It is another object of the present invention to make such a longitudinal 
head resistant to wear and to variations in air bearing contours. 
Still another object of this invention is to create a longitudinal head 
which is suitable for batch processing in planes parallel to the surface 
of the initial wafer or substrate. 
It is a further object of this invention to produce a suspension system 
which allows anisotropic stiffening and shaping for maximum actuator 
bandwidth. 
The present invention provides a combination suspension and transducer 
magnetic head for use with longitudinal recording media which can be used 
for contact recording as well as for flying above the media. Preferably a 
release layer is first deposited on a substrate and then individual thin 
film layers of the transducer are deposited. The coils are horizontal with 
a vertical or almost vertical second pole piece relative to the first pole 
piece. The backgap is displaced horizontally from the poletips. The 
transducers are deposited on a wafer in rows and columns. The suspension 
layers are then deposited on the transducer rows again preferably on 
release layers between the suspension layers and the substrate. The 
substrate is removed by attacking the release layers to leave a 
combination suspension and transducer produced by batch fabrication. 
The horizontal head is fabricated with sidewall gap technology. The 
suspension is preferably created by deposited alumina and is formed by 
etching the alumina into the desired shapes followed by separating the 
alumina from the substrate surface. Removal of the completed reed assembly 
from the substrate is preferably accomplished utilizing a release layer. 
Additionally, the planar deposition arrangement for the present invention 
permits all processing of the head and the suspension to be performed on a 
wafer surface. This allows batch production of the head and the suspension 
as one unit. 
Still another advantage of the present invention is the use of wear 
resistant material on the head structure. This protects the poletip 
regions of the head and may be localized through patterning of the 
suspension surface to create a favorable air bearing loading condition for 
the head and suspension.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred embodiments of the present invention are preferable for use 
in high density direct access storage devices such as found in large 
information storage systems as well as in the single disk files typically 
used in personal computers. The devices, e.g., disk drives or files, may 
use magnetic memory disks as the media. 
Referring now to FIG. 1, a linear actuator 10 and a segment of an 
associated disk 12 of a data recording disk file is shown. The linear 
actuator 10 includes a voice coil motor, which comprises a coil 14 movable 
within the magnetic field of a fixed permanent magnet assembly (not 
shown). The magnet assembly includes a core within the coil 14 and an 
outer structure supported by a housing 16. One end of an actuator arm 20 
is attached to the movable coil 14. Attached to the other end of the 
actuator arm 20 is a plurality of support arms 21, each of which support a 
combination transducer-slider-suspension reed assembly 22 produced 
according to the procedure set forth herein. The combination assembly 22 
includes a suspension section 26 and transducer-slider 24 formed at one 
end integral with the suspension section 26. The suspension section 26 
supports the transducer-slider 24 above the surface of the disk 12 on a 
bearing or cushion of air generated by the rotation of the disk 12. 
Alternatively, the suspension section 26 may support the transducer-slider 
24 in contact with the disk media 12. The air bearing or air bearing 
surface (ABS) refers to the surface of the slider parallel to and adjacent 
the disk surface. It includes both configurations where the slider is 
designed to fly above the disk, sometimes referred to as a winchester-type 
drive, and where the slider is designed to contact the recording media, 
the disk 12, during operation. 
The actuator arm 20 includes a plurality of the arms 21 with each arm 21 
supporting the combination reed assembly 22, each combination assembly 22 
associated with each surface of the disk 12. Therefore, disk 12 also has a 
combination assembly 22 mounted to an arm 21 of the actuator arm 20 on the 
underside of the disk 12. Further, other combination assemblies are 
associated with the top and bottom sides of other disks, the transducer 
access of which is controlled by the actuator 10. 
The suspension section 26 of the combination transducer-slider-suspension 
assembly 22 provides a load to the transducer-slider 24 which is generally 
perpendicular to the surface of the disk 12. This perpendicular load 
maintains the transducer-slider assembly 24 in contact with the data 
surface of the disk 12 when the disk 12 is not in rotation. During 
operation of the disk drive a lifting force is generated between the 
transducer-slider 24 ABS and the rotating disk 12 opposing the 
perpendicular load applied to the transducer-slider 24 causing the 
transducer-slider 24 to fly above the disk surface. Alternatively, in 
contact recording, during rotation of the disk 12, the transducer-slider 
24 remains in contact with the media for reading or recording data. 
During operation, the transducer-slider 24 is moved to the desired track of 
the plurality concentric data tracks defined on the data surface of the 
disk 12 by means of the coil 14. The coil 14 is controlled by positioning 
signals to move within the magnetic field of the magnet assembly. Because 
it is desired to provide rapid access of the transducer-slider 24 from one 
track to another track for read or write operations, it is necessary that 
the transducer be properly positioned over the desired track and reach 
that track in a minimum amount of time. It should be noted that while the 
actuator 10 illustrated in FIG. 1 is a linear actuator which moves the 
combination assembly 22 in a precise direction transverse to the data 
tracks, other types of conventional disk files utilize a rotary actuator 
such as is shown in the aforementioned U.S. Pat. No. 3,849,800 and in FIG. 
2 herein. The combination reed assembly 22 must provide radial stiffness, 
and have substantial flexibility in the pitch and roll directions as it 
rides above the data surface of the disk 12. If desired, an integrated 
circuit amplifier assembly 28 may also be produced on the suspension 
section 26 of the combination assembly 22. 
Referring now to FIG. 2, a data recording disk file including a housing 25 
in which is mounted a rotary actuator 27, an associated disk 34 and a 
drive means 32 for rotating the disk 34 is shown. The rotary actuator 27 
moves a combination reed assembly 30 of the present invention in an 
arcuate path over the disk 34. The rotary actuator 27 includes a voice 
coil motor, which comprises a coil 36 movable within the magnetic field of 
a fixed permanent magnet assembly 38. An actuator arm 29 is attached to 
the movable coil 36. The other end of the actuator arm 39 is attached to 
the combination transducer-suspension assembly 30 of the present invention 
produced according to the procedure set forth herein. 
Referring now to FIGS. 3A, 3B, 4A and 4B, a preferred embodiment of the 
combination suspension/transducer-slider reed assembly according to the 
principles of the present invention is illustrated. The combination 
suspension/transducer-slider structure 30 comprises an elongated generally 
rectangular body of a dielectric material such as aluminum oxide (Al.sub.2 
O.sub.3) or silicon dioxide (SiO.sub.2), for example, having a relatively 
uniform thickness along most of its length forming a suspension section 37 
and a somewhat greater thickness at one end, the left hand end as shown, 
wherein a magnetic read/write transducer or head 40 is formed and a slider 
air bearing surface (ABS) is patterned on a lower side thereof. As 
mentioned above, the term ABS refers to the side of the slider which is 
generally parallel to and adjacent the media surface in both 
winchester-type disk files and contact recording applications. As shown in 
FIG. 3A, the ABS comprises a shaped protrusion 33 formed on the lower side 
of the reed assembly body 31, preferably forming a contact pad for contact 
recording applications. Alternatively, the shaped protrusion 33 can form a 
slider having an ABS patterned to generate a lifting force when relative 
motion exists between the reed assembly 30 and the media to allow the 
slider to fly closely above the media surface. The surface of the shaped 
protrusion 33 is coated with a wear layer 35 of suitable material, such as 
diamond-like carbon, for example, to minimize wear and damage when the 
reed assembly contacts the media surface. Although protrusion 33 as shown 
in the figures comprises a simple structure, other embodiments of the 
present invention can include a multiple-stepped protrusion which allows 
the wear layer 35 to continue to provide wear protection to the slider 
surface even after the magnetic yoke poletips have been exposed at the 
ABS, either by wear or by a brief post-fabrication lapping process 
intended to reduce the magnetic separation between the head and the disk 
surface caused by the thickness of the wear-resistance layer in the pole 
tip region. 
The read/write head 40 is formed integrally with the suspension section 37 
to provide the combination reed assembly 30. In the preferred embodiment, 
the read/write head 40 comprises a ring-type head utilized in horizontal 
recording applications, but can alternatively comprise a probe-type head 
for perpendicular recording applications. The read/write head 40 includes 
a magnetic circuit comprising an upper magnetic yoke 43 magnetically 
coupled to a lower yoke 45 at a front stud 53 and a back-gap stud 55. The 
lower yoke 45 is broken to form a horizontal gap 47 between the two pole 
pieces formed by the break in the lower yoke 45. The lower yoke 45 is 
shaped to provide the gap 47 near the surface of protrusion 33 with the 
poletips substantially co-planar so as to be closely adjacent the 
recording media. Inductively coupled to the magnetic yoke structure is a 
horizontal spiral coil 41, with the ends of the coil connecting through 
lead conductors 49 extending the length of the suspension section 37 to 
terminal bonding pads 51. 
In a preferred embodiment, the combination reed assembly 30 comprises a 
body 31 of Al.sub.2 O.sub.3 having a length of 12 millimeters (mm), a 
width of 0.5 mm and a thickness of 35 micrometers (.mu.m) for that portion 
of the body 31 forming suspension section 37 and maximum thickness of 50 
.mu.m for the read/write head section 33. The reed assembly 30 is 
fabricated utilizing well-known deposition and photolithography techniques 
on a base substrate, as described in greater detail below, utilizing a 
release layer to separate the finished reed assembly from the substrate. 
The upper and lower magnetic yokes 43 and 45 are of nickel-iron alloy 
(NiFe), generally referred to as permalloy, or other suitable magnetic 
material, such as iron (Fe), nickel (Ni) and cobalt (Co) or their alloys, 
and are preferably plated as is well-known in the art. Similarly, the coil 
windings 41, lead conductors 49 and terminal bonding pads 51 are also 
formed of copper (Cu) or gold (Au), for example, by plating techniques. 
Manufacturability of this embodiment is greatly simplified in that the 
complete reed assembly 30 is fabricated in layers parallel to the 
supporting substrate by conventional, well-known techniques. 
Referring now to FIGS. 5A and 5B, cross sectional views of two further 
embodiments for the poletip configuration of the present invention are 
shown. FIG. 5A illustrates one embodiment of a horizontal poletip 
configuration read/write head 40A. This embodiment is fabricated using a 
free standing side wall technique such as described by Lazzari et al., "A 
New Thin Film Head Generation I.C. Head," IEEE Transactions on Magnetics, 
Volume 25, No. 5, page 3190, 1989. Pole pieces 42A and 44A are spaced 
apart by a magnetic gap 46A. This permits the horizontal head 40A to read 
and write magnetic signals and to communicate these signals via coils 48A 
to circuitry (not shown) of its associated disk drive. 
In a similar fashion, the horizontal head 40B shown in FIG. 5B utilizes 
pole pieces 42B and 44B separated by a gap 46B. Horizontal head 40B 
communicates via coils 48B. The pole piece 42B is slanted and can be 
fabricated without the use of a free standing sidewall such as required 
for the embodiment shown in FIG. 5A. 
FIGS. 6A-6F are cross-sectional views illustrating the processing steps 
involved in the fabrication of a preferred embodiment of the present 
invention incorporating the horizontal head shown in FIG. 5B. A seed layer 
57 is first deposited by sputter deposition, for example, on the substrate 
52. The next step is the deposition of a layer of photoresist 50 onto the 
substrate 52 over the seed layer 57 and then etching or otherwise forming 
a resist pattern having a slope 54. The substrate 52, as shown, represents 
a substrate and release layer as described in greater detail with 
reference to FIG. 7 below. A first pole piece layer 56 of NiFe, for 
example, and a separation layer 58 of copper (Cu), for instance, are 
deposited onto the seed layer 57, as is shown in FIG. 6B. The separation 
layer 58 provides separation between the two pole pieces of the head. The 
only requirement for the separation layer 58 is that it be of a 
non-magnetic material. The slope 54 of the resist pattern causes the 
layers 56 and 58 to be formed with a slope 60. Preferably the first pole 
piece layer 56 and the Cu layer 58 are sequentially plated onto the 
substrate 52. A layer 62 of a magnetic gap material is then deposited over 
the layers 56 and 58 after the resist pattern of the photoresist 50 is 
removed as is shown in FIG. 6C. FIG. 6D shows that the unneeded material 
of the magnetic gap layer 62 is then removed through a resist mask and 
etch step, for example (not shown), to provide a gap layer 62 covering 
only the slope 60 (see FIG. 6B) of the layers 56 and 58. A photoresist 
pattern 64 for deposition of the second pole piece is then provided as is 
shown in FIG. 6E. A layer of NiFe, for example, is then deposited, again 
preferably by plating, and the resist pattern 64 removed to form a second 
pole piece 68 as is shown in FIG. 6F. The first pole piece layer 56 
determines the throat height for the resultant poletip structure 70, as is 
shown in FIG. 6F. The poletip structure 70 comprises a first pole piece 
formed by the NiFe layer 56 and a second pole piece formed by the NiFe 
layer 68 having a gap therebetween formed by the gap layer 62. The 
separation layer 58 thickness is determined by the minimum required 
separation distance between the first pole piece formed by NiFe layer 56 
and the later deposited second pole piece 68. While FIG. 6F illustrates 
the gap layer 62 slanted at the angle formed by slope 60, the slanted gap 
layer is not restricted to the slope as shown. That is, the slope of the 
slanted gap layer can be at any angle between 90 degrees, i.e., 
perpendicular and .+-.70.degree. with respect to the plane of the 
substrate 52. 
An important consideration in the process shown in FIGS. 6A-6F is the 
material utilized for seed layer 57 required for the deposition of both 
pole piece layers 56 and 68. Preferably a plating process is used and a 
single seed layer 57 can be used for plating both pole pieces. However, if 
the seed layer material used is magnetic, it must not be present in the 
magnetic gap 65 to prevent magnetically shorting the gap 65. If the seed 
layer is non-magnetic and deposited over the magnetic gap 65 and is 
greater than a fraction of a microinch, it generally should be removed to 
minimize the magnetic head/disk separation. If the non-magnetic seed layer 
is of a material suitable for use as a wear layer, the need for deposition 
of a separate wear layer can be eliminated. 
Referring now to FIG. 7, a cross-sectional view illustrating the various 
process layers utilized in the fabrication of a preferred embodiment of 
the present invention is shown. One objective of the present invention is 
to fabricate horizontal type heads and encapsulate these heads in a 
suspension structure fabricated by thin film deposition of a dielectric 
material, such as Al.sub.2 O.sub.3 (alumina), for example. The suspension 
shape is patterned around the horizontal head using conventional etching 
techniques well known to those in the art. The completed head and 
suspension assembly is separated from the substrate using a release or 
sacrificial layer between the substrate and dielectric suspension 
material. All processing is performed in planes parallel to the wafer 
substrate surface. 
With continuing reference to FIG. 7, a process carrier substrate 81 can be 
of any suitable material known to those in the art, such as 
alumina-titanium-carbide (AlTiC) or silicon, for example. A sacrificial or 
release layer 83 is then formed on the substrate 81. The release layer 83 
serves several purposes. The release layer 83 is the sacrificial layer 
which is eventually dissolved to free the finished suspension-transducer 
assembly 80 from the substrate 81. The release layer 83 can also be 
patterned to shape a subsequently deposited wear layer. The release layer 
83 can, for instance, be an electrically conductive material and thereby 
serve as a seed or plating base layer for the subsequent layers deposited 
utilizing plating techniques, such as the pole pieces of the transducer. 
Likely candidates for the release layer 83 are NiFe or Cu which could be 
deposited through a sputtering or plating process. A barrier layer 85 is 
then formed over the release layer 83. 
The barrier layer 85 similarly serves several functions in the production 
process. The barrier layer 85 is used to isolate the subsequently 
deposited layers from the release layer 83. For instance, the magnetic 
poletip structure 70 and head 90 formed as described with reference to 
FIGS. 6A to 6F can be the subsequently deposited layers. Thus pole pieces 
71 and 73 of FIG. 7 can be formed in the same manner as discussed for the 
pole pieces 68 and 56, respectively, of FIGS. 6A-6F. The barrier layer 85 
serves as an etch stop to protect the pole pieces from any etchant which 
may be later used to dissolve the release layer 83. Additionally, the 
barrier layer 85 may be used as the seed layer for plating of the pole 
pieces 71 and 73, as described above, for example. Even more, the barrier 
layer 85 may be used as a wear layer to protect the pole pieces during 
operation in close proximity to a rotating magnetic media. In this 
capacity, it is preferable that the barrier layer 85 be an electrically 
conductive material which could assist in promoting a longer lifetime in a 
contact recording mode. If the barrier layer 85 is not to be used also as 
a wear layer, it is desirable to remove it after the release layer 83 is 
dissolved. 
A thin film deposition process for fabrication of the pole piece structure 
70 utilized in the embodiment shown in FIG. 7 has been described with 
reference to FIGS. 6A-6F. While the described process only concerned the 
formation of the poletips and the magnetic gap therebetween, it is 
understood by those skilled in the art fabrication of the poletip 
structure 70 is not an isolated process, but is integrated with the 
fabrication of the entire magnetic head 90. For example, the entire lower 
pole piece or lower yoke 73 is typically formed in one plating operation 
rather than just forming the lower poletip 56 and later forming the 
remainder of the lower yoke 73. On the other hand, because of various 
difficulties well-known in the art which can be encountered during its 
fabrication, the upper poletip 68 is formed in a separate plating step and 
the remainder of the upper pole piece or upper yoke 71 plated and 
"stitched" to the upper poletip 68 in a subsequent process step after the 
coil windings 77 and lead conductors 79 have been formed. Alternatively, 
the entire upper pole piece 71 including poletip 68 can be placed in a 
single process step subsequent to the plating of the coil windings 77 and 
lead conductors 79. Similarly, the formation of the dielectric layer 75 
including the separation layer 58 in which the coil windings 77 are 
embedded can be accomplished in a single step or series of steps prior to 
the plating of the upper poletip 68. However, if a non-magnetic electrical 
conductive material such as Cu is utilized as the separation layer 58, it 
will be necessary to form the dielectric layer separately because the coil 
windings 77 must be embedded in an insulating material. 
When fabrication of the transducer 90 is complete, a layer of a suitable 
dielectric material, such as alumina, for example, is deposited over the 
magnetic transducer 70 to provide the transducer suspension assembly 80 to 
support the transducer 70 in sensing relationship with the magnetic media 
(as shown in FIGS. 1 and 2). The suspension section 87 includes coil turns 
77 and associated conductor leads 79 embedded in the layer or layers that 
form the suspension section 87. Contact studs 78 are formed in the 
suspension section 87 at the external termination points of the conductors 
79 at the end opposite the transducer 90. 
Preferential aspects of the present invention are the use of an 
electrically conductive release layer 83 as the primary seed layer, with 
possibly a thin electrically conductive barrier layer 85 on top to provide 
a wear layer for the completed poletip structure 70. The wear layer could 
thereby be thin without any lapping process. In this embodiment, the pole 
pieces 71 and 73 are preferably formed by a plated Permalloy process. A 
light lapping of the pole pieces may be required to insure a planar or 
level poletip structure 70 from this fabrication process. 
Referring now to FIGS. 8A-8D, perspective views of preferred embodiments of 
the present invention wherein the reed assembly body is fabricated in 
desired shapes to provide specific suspension characteristics are shown. 
Since the reed assembly is fabricated on a substrate with thin film 
technology, it is possible to locally shape and stiffen the suspension. 
The topographical shape of the suspension system can be as shown in the 
aforementioned Watrous U.S. Pat. No. 4,167,765 or in any of the other 
planar view shapes commonly used. The planar shape of the suspension 
should not be taken as a limiting factor in this invention. In FIG. 8A a 
reed assembly body 92 comprises an elongate structure having a generally 
rectangular (parallel piped) shape in which the suspension characteristics 
are determined primarily by the material and the length, width and 
thickness of the structure. In FIG. 8B, the reed assembly body 94 
comprises a suspension section 91 in which the width of the body is 
changed to form a trapezoidal section 93 necking down to the transducer 
section 95. In this embodiment, the suspension characteristics are 
primarily determined by the change in width between the suspension section 
91 and the transducer section 95 and the rate of width change; i.e., the 
length of trapezoidal section 93. FIGS. 8C and 8D illustrate the reed 
assembly of FIG. 8A wherein one or more longitudinal ribs 97 or one or 
more transverse grooves, respectively, have been formed on the upper 
surface of the suspension section of the reed assembly body 96 and 98, 
respectively. In these embodiments, the number and dimensions of the ribs 
97 or grooves 99, respectively, effectuate selective stiffening or a 
decrease in the stiffness of the reed assembly suspension. 
Referring now also to FIGS. 9A and 9B, side views of the reed assembly 
suspension section illustrating one processing technique employed to 
create the localized patterning to fabricate a thin film suspension system 
in a plane parallel to the top plane of the process carrier substrate to 
effectuate the selective stiffening shown in FIG. 8D is shown. As 
illustrated in FIG. 9A, a release layer 100 is formed on a substrate 102. 
The thickness of the release layer 100 is varied locally to provide 
thinner portions 104 and thicker portions 106 to provide a mold having the 
desired suspension patterning in reverse relief. This is accomplished, for 
instance, by plating two layers of the release material. The second layer 
is patterned by photoresist, or by plating a thick layer of the release 
material and then locally milling or etching areas of the release layer 
100. This approach is also useful for creating the ABS contour mold. A 
suspension material 108 is deposited onto the release layer 100 mold to 
selectively vary the thickness of the suspension material 108. The 
suspension material 108, when separated from the release layer 100, 
becomes the suspension portion 110 of a thin film transducer-suspension 
reed assembly as is shown in FIG. 9B. 
A second approach is illustrated in FIGS. 9C and 9D to locally etch or 
pattern a layer of suspension material 111 deposited onto a release layer 
112. The release layer 112 in formed by depositing a release material onto 
a substrate 114. The top of the suspension layer 110 is patterned with 
photoresist and etched at portions 116 to provide a suspension layer that 
is flexible along its length. The top of the suspension layer is etched at 
portions 116 while it is still attached to the release layer 112 and the 
substrate 114. After the release layer 112 is dissolved, a contoured 
suspension portion 118 is obtained. By using a combination of the 
techniques shown in FIGS. 9A and 9C, both the top and bottom surfaces of a 
suspension system can be featured as desired in a batch process. Using the 
illustrated techniques, suspension structures can be obtained with 
localized patterning to increase or decrease localized stiffness as well 
as provide desired air bearing surface contouring. 
Referring now to FIG. 10, a side view in section of a transducer-suspension 
combination assembly 120 incorporating the horizontal transducer shown in 
FIG. 5A is shown. The assembly 120 includes a horizontal transducer 122 
which can be produced according to the side-wall process described by 
Lazzari referenced herein above. A wear layer 124 and coils 126 can be 
produced in the same process. Conductor leads 128 and stud pads 130 can be 
provided as discussed with reference to FIG. 7 along the length of a thin 
film suspension section 132. The suspension section 132 can include one or 
more stiffening portions 134 and 136 to support the transducer 122, and a 
contoured air bearing surface portion 136 which will control the flying 
height of the transducer 122. 
The conductor leads 128 are preferably plated copper. The conductor leads 
128 are routed along the suspension structure 132 to the stud pads 130. 
The conductor leads are configured in a stripline arrangement since the 
suspension 132 is thin and the stress symmetry required is compatible with 
a stripline design. The suspension section 132 is preferably produced by 
depositing alumina or other suitable material onto the release layer of 
FIG. 9A. Standard stud and pad technology is used to produce the stud pad 
130 to complete the thin film head/suspension reed assembly 120. A thick 
deposition of alumina can be used to ensure complete encapsulation of the 
transducer 122 followed by a lapping operation to planarize the top 
surface of the transducer-suspension assembly. 
The alumina suspension material is preferably sputtered to a thickness of 
from 20 to 50 micrometers. The suspension shape is formed by etching the 
overcoat and undercoat of alumina. After the suspension shape is formed, 
the release layer is dissolved to free the head/suspension devices for 
use. 
The described head-suspension structure embodiment is suitable for 
longitudinal recording and is resistant to wear along its poletips and the 
air bearing surface contours. This structure can be batch processed in 
planes parallel to the starting wafer surface and allows for anisotropic 
stiffening for maximum actuator bandwidth. Production of these 
suspension/transducer assemblies is facilitated since an extensive lap 
process is avoided. 
While the invention has been particularly shown and described with 
reference to preferred embodiments thereof, it will be understood by those 
skilled in the art that various changes in form and detail may be made 
therein without departing from the spirit and scope of the invention. For 
instance, a transducer may be produced onto the wafer such as is described 
in U.S. Pat. No. 4,190,872, assigned to the assignee of the present 
invention. The wafer may be made of material such as is the subject matter 
of the Jacobs U.S. Pat. No. 4,251,841, entitled "Magnetic Head Slider 
Assembly" and assigned to the assignee of the present invention. Although 
the suspension portions of the present invention are preferably composed 
of sputter-deposited alumina, it is recognized that other methods of 
deposition may be employed and that other materials may be utilized, 
including other suitable oxides, nitrides, carbonides, glasses, amorphous 
carbon, diamond-like carbon or laminated combinations of suitable 
conducting and insulating materials. The suspension section according to 
the preferred embodiments could be a dual layer of a polyimide material 
and a metal layer deposited thereon to provide sufficient resiliency and 
stiffness as required by a suspension assembly. It should be noted that 
the suspension assembly could be produced in a single layer if the correct 
thickness and stiffness were obtained in the single layer. It is also well 
understood that many electrically conductive materials are available to 
form the conductive circuitry and the transducer leads. Copper or gold is 
the preferred conductive material but many others are available as is well 
known in the art. While air bearing suspensions are discussed herein, the 
present invention also includes contact recording wherein the air bearing 
surface is any suitable surface that can be placed in contact with the 
media during operation. It should also be evident that the linear actuator 
could be a rotary styled actuator without departing from the present 
invention.