WO1999005673A1

WO1999005673A1 - An improved gimbal for a head of a disc drive

Info

Publication number: WO1999005673A1
Application number: PCT/US1998/008175
Authority: WO
Inventors: Richard A. Budde
Original assignee: Seagate Technology, Inc.
Priority date: 1997-07-23
Filing date: 1998-04-22
Publication date: 1999-02-04

Abstract

A base mounting portion (60) connects the gimbal spring (40) to a load beam (36) and thereby to the actuator (22) of the disc drive which positions the gimbal (40) and slider (20) over a desired track on the disc. The gimbal (40) includes opposed flexure arms (62, 64) which are formed of elongated members, each having a proximal end and a distal end which define an opening therebetween. The proximal ends of the flexure arms (62, 64) are operably coupled to the base (60), and the distal ends are cantilevered. A mounting tab (66) is positioned between the ends of the flexure arms (62, 64) and supports the slider (20). Bridge sections (76, 78) are provided which connect the distal ends (74) of the flexure arms (62, 64) to the mounting tab (66), the bridge sections (76, 78) extending at an angle relative to the flexure arms (62, 64) and being angled back toward the base section (60) of the gimbal (40).

Description

AN IMPROVED GIMBAL FOR A HEAD OF A DISC DRIVE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U. S. Provisional Patent Application Serial No. 60/053,480, filed July 23, 1997, and entitled AN IMPROVED GIMBAL FOR AN OPTICALLY-ASSISTED WINCHESTER DRIVE.

BACKGROUND OF THE INVENTION

The present invention relates to a disc drive assembly. In particular, the present invention relates to an improved suspension design for supporting a head relative

to a disc surface.

Disc drive systems are known which read data from a disc surface during

operation of a disc drive. Such disc drive systems include conventional magnetic disc drives and optical disc drive systems. Optical disc drive systems operate by focusing a laser beam onto a disc surface via an optical assembly which is used to read data from

the disc surface. Conventional magnetic disc drive systems use inductive type heads for reading or writing or magnetoresistive (MR) heads for reading data. Discs are rotated

for operation of the disc drive via a spindle motor to position discs for reading data from

or writing data to selected positions on the disc surface.

Known optical assemblies include an objective lens and a solid immersion lens

(SIL) which is positioned between the objective lens and the disc surface. The SIL is

positioned very close to the data surface of the disc and is described in U.S. Patent No.

5, 125,750 to C. Orle et al., which issued June 30, 1992, and in U.S. Patent No.

5,497,359 to Marnin et al., which issued March 5, 1996. In these optical systems, a laser

beam is focused onto the SIL using an objective lens. The SIL is preferably carried on a slider and the slider is positioned close to the disc surface. Use of an SIL increases storage density.

The slider is generally formed of a transparent material and includes an air

bearing surface to fly the SIL above the disc surface. The slider includes a leading edge and a trailing edge. Rotation of discs creates a hydrodynamic lifting force under the

leading edge of the slider to lift the leading edge of the slider to fly above the disc surface in a known manner. The slider preferably flies with a positive pitch angle in which the leading edge of the slider flies at a greater distance from the disc surface than the trailing edge via a suspension assembly which includes a load beam and gimbal

spring. The slider is coupled to the load beam via the gimbal spring. The load beam applies a load force to the slider via a load button. The load button defines an axis about which the slider pitches and rolls via the gimbal spring. The slider is preferably resilient in the pitch and roll direction to enable the slider to follow the topography of the disc.

The flexure of the gimbal spring permits the air bearing slider to pitch and roll

as the slider flies above the disc surface. It is important to maintain the proximity of the

SIL and slider relative to the disc surface to maintain the proper focus of light onto the disc surface as is known for optical disc drive systems. It is important that the flexure system including the load beam and the gimbal spring be designed to stably and

accurately support the SIL during operation of the disc drive system. In a magneto-

optic (M-O) system, a magnetic transducer element is carried on the slider to write data

to the disc surface. It is also important to accurately support and position the magnetic transducer elements relative to the disc surface during operation of an M-O system.

An actuator mechanism is coupled to the suspension assembly to locate the

SIL relative to selected disc positions for operation of the disc system. During movement of the suspension system, force is transmitted through the load beam and

gimbal spring to move the slider. Operation of the actuator mechanism, air bearing surface, and spindle motor introduce external vibration to the slider and suspension assembly. Depending upon the mass and stiffness of the suspension assembly, including the gimbal spring and load beam, external vibration may excite the load beam and gimbal

spring at a resonant frequency. Thus the input motion or external vibration may be amplified substantially, causing unstable fly characteristics and misalignment of the slider

relative to the disc surface.

External vibration or excitation of the suspension assembly and slider may introduce varied motion to the slider and suspension assembly. Depending upon the

nature and frequency of the excitation force, the slider and suspension assembly may cause torsional mode resonance, sway mode resonance, and bending mode resonance.

Torsional mode motion relates to rotation or twisting of the suspension assembly about an in-plane axis. Bending mode resonance essentially relates to up-down motion of the suspension assembly relative to the disc surface. Sway mode vibration relates to in-plane

lateral motion and twisting. It is important to limit resonance motion to assure stable fly

characteristics for the SIL. In particular, it is important to control the torsion and sway

mode resonance, since they produce a transverse motion of the slider, causing head

misalignment with respect to the data tracks on the disc surface.

The resonance frequency of the suspension assembly is related to the stiffness or elasticity and mass of the suspension system. Thus, it is desirable to design a

suspension system which limits the effect of sway mode and torsion mode resonance in

the operating frequencies of the disc drive while providing a suspension design which

permits the slider to pitch and roll relative to the load button, and which has relatively high lateral rigidity and stiffness for maintaining precise in-plane positioning of the slider along the yaw axis.

SUMMARY OF THE INVENTION Thus it is an object of the present invention to provide an improved

suspension system for a disc drive. More specifically, it is an objective to provide an improved gimbal design which limits resonance which assures stable flying

characteristics for the slider in a disc drive, especially in an optical disc drive.

A further object of this invention is to provide an improved gimbal which limits the resonance motion to assure stable flying characteristics for the gimbal. More

specifically, the objective of the invention is to limit the rotational or twisting motion of the suspension as well as the up-down motion of the suspension relative to the disc

surface.

These and other objectives of the invention are achieved by providing a gimbal spring which flexibly supports the slider relative to the disc surface. The design

incorporates a base mounting portion which connects the gimbal spring to a load beam

and thereby to the actuator of the disc drive which positions the gimbal and slider over

a desired track on the disc. The gimbal includes opposed space flexure arms which are formed of elongated members, each having a proximal end and a distal end which define

an opening therebetween, the proximal ends of the flexure arms being operably coupled

to the base, and the distal end being cantilevered. A mounting tab is positioned between

the ends of the flexure arms and supports the slider. Bridge sections are provided which connect the distal ends of the flexure arms to the mounting tab, the bridge sections

extending at an angle relative to the flexure arms and being angled back toward the base section of the gimbal. More specifically, the bridges are curved to conform to the

curvature of an optical lens mounted on the slider to be used to read information from

or store information on the surface of the disc.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic illustration of operation of an optical disc drive system.

Figure 2 is a side view of a slider supporting an SIL. Figure 3 is a top view of a suspension assembly coupled to an actuator mechanism for supporting a slider relative to a disc surface (not shown).

Figure 4 is a cross-sectional view taken along line 4—4 of Figure 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 is a simplified diagram illustrating an optical storage system using

a solid immersion lens (SIL). Optical system 10 includes an optical disc 12 having a data

surface which carries optically encoded information. Disc 12 rotates about spindle 14

and is driven by a spindle motor 16 mounted on base 18. A slider 20 is movably supported relative to disc surface 12 via an actuator mechanism 22.

The slider 20 supports an SIL 24 for focusing a laser beam of an optical

system on the disc surface for reading optically-encoded information. The actuator

mechanism 22 preferably includes a voice coil motor 26. The slider 20 is coupled to the

voice coil motor via a suspension assembly 28. The optical system includes an optical head 30 which preferably is coupled to the actuator mechanism 22 and operated thereby. The optical head 30 includes a laser beam which is focused onto the disc surface via the

SIL 24 in a known manner for operation of the optical disc drive system.

Figure 2 illustrates the slider 20 and SIL 24 construction. Preferably, the slider is formed of a transparent material, such as a cubic zirconia. The SIL 24 is bonded to the slider 20 or, alternatively, the slider 20 and SIL 24 may be formed of an integral material machined from a single piece of crystal. For example, the integrated SIL 24 and slider 20 can be formed by injection molding a single piece of transparent material such as a commercially available polycarbonate in a known manner. The slider 20 includes

an upper surface 32 and a lower air bearing surface (.ABS) 34 (surface not visible in Figure 2) which is formed in a known manner to provide a hydrodynamic lifting force to the slider 20 and the lens 24 via rotation of optical disc 12 in a known manner.

The slider 20 is supported by a suspension assembly 28 operably coupled to

the actuator mechanism. In particular, as illustrated in Figure 3, the suspension assembly

28 includes a load beam 36, a mounting plate 38, and a gimbal spring 40. The mounting plate 38 is coupled to the actuator mechanism 22 via stake 42 in a known manner.

Preferably, the load beam 36 is formed of an elongated flexible material which includes

side rails 44 and a load tab 46 having load button 48 (on a lower surface of load tab 46)

at an extended end of the load beam 36 as will be explained. Side rails 44 provide lateral

and bending stiffness and a means for connecting wires (not shown) to the slider 20.

The gimbal spring 40 is coupled to the load beam 36 and flexibly supports slider 20 relative to the load beam 36. The load button 48 applies a load force to the

upper surface 32 of the slider and defines a gimbal pivot axis 50 about which the slider

20 can pitch, and pivot axis 68 about which the slider 20 can roll, relative to the disc

surface for operation of the disc drive. The lower air bearing surface 34 of the slider 20 (not shown) faces the disc

surface so that rotation of disc 12 provides a hydrodynamic lifting force to the slider 20

which flies above the disc surface as data is read and written to the disc surface. The

load force counteracts the hydrodynamic lifting force of the ABS. The slider is lifted via the ABS surface to fly at a pitch angle relative to the disc surface. During operation of the disc drive, it is important to maintain a stable fly height for slider 20 close to the disc surface and that the slider 20 be able to pitch and roll to follow the topography of the disc surface. Thus, the gimbal spring 40 should be

designed to support the slider relative to the load beam to allow sufficient pitch and roll of the slider 20 during operation. If the pitch and roll stiffness of the gimbal spring is too

low, it will be difficult to control the fly characteristics of the slider and the gimbal will exhibit undesirable resonance behavior. If the gimbal spring 40 is too stiff in the pitch

and roll axis, then the slider will not be able to follow the topography of the disc surface.

During operation, the actuator mechanism 22 moves the suspension assembly to position the slider 20 and SIL 24 relative to selected positions on the disc surface.

Rotation of the disc supplies a lifting force to the slider 20 at the ABS surface.

Operation of the slider thus introduces vibration to the suspension system which,

depending on the construction of the suspension assembly and gimbal spring 40, may coincide with the resonance frequencies of the suspension system, causing the external

motion to be amplified. Vibration of the suspension system at the resonance frequencies

may interfere with placement and operation of the slider 20. Typical excitation forces

are fairly low-frequency, less than 10,000 Hz. Thus, it is desirable to design the gimbal spring so that its resonance frequencies are high to avoid resonance vibration at typical

operation frequencies of the disc drive. Further, as discussed, during operation of an optical disc drive, a slider 20 supports an SIL 24 above the disc surface via operation of the ABS surface and the load force of the load beam 36. Depending upon the position of the load button 48 and gimbal pivot 50, the weight of the SIL 24 may be unbalanced relative to the load position and during operation may excite the gimbal spring 40. Depending upon the design of the suspension system this vibration is amplified at the resonance frequency,

thus degrading the performance of the SIL 24. The gimbal spring 40 of the present invention is designed to provide desirable pitch and roll stiffness with desired resonance frequency as will be explained. As shown in Figure 3, the slider includes a leading edge 52 and a trailing edge

54, and the distance between the leading edge and trailing edge defines the longitudinal extent of the slider. The SIL 24 is positioned toward the trailing edge 54 of the slider

20 on a rear portion 56 of the slider 20. Since the SIL 24 is positioned along the rear portion 56, the distribution of weight between forward portion 58 and rear portion 56

is unbalanced. The load tab 46 extends from the leading edge 52 along a forward

portion 58 of the slider. The load tab 46 is sized to extend along the forward portion 58

to a center portion 59 of the slider so that the pivot axis 50 is generally at the center

portion 59 of the slider 20 for flight stability of the slider 20 during operation.

The suspension assembly illustrated in Figure 3 illustrates an embodiment of

a gimbal spring 40 of the present invention for supporting slider 20 designed to optimize pitch and roll stiffness and gimbal resonance characteristics. As shown, the gimbal

spring 40 generally includes an elongated mounting portion or base 60, spaced flexure

arms 62, 64 and a slider mounting tab 66. The gimbal spring 40 is cantileveredly

supported relative to the load beam 36 via mounting portion 60. Spaced flexure arms 62, 64 are supported by and extend from the mounting portion 60 in spaced cantilevered

relation. Slider mounting tab 66 is operably coupled to the flexure arms 62, 64 and is

fixedly secured to the slider 20 to flexibly support the slider 20 relative to the load beam

36 to gimbal (pitch and roll) relative to pivot axis 50 and 68.

The flexure arms 62, 64 are spaced relative to the width of the slider 20 a certain distance from the centerline 68, and width 70 of each of the flexure arms 62, 64

is sized to provide desired roll characteristics. If the flexure arms 62, 64 are spaced too far apart, roll stiffness increases and if spaced too close, roll stiffness is too low. If the width 70 of the flexure arms 62, 64 is too thick, roll stiffness increases and if too thin, roll stiffness is too low. Flexure arms 62, 64 include a proximal end 72 and a distal end

74. The proximal end 72 is coupled to mounting portion 60 and distal end 74 is coupled to mounting tab 66. The proximal end 72 is fixed relative to the load beam 36 and the distal end 74 flexibly supports slider 20 relative to the pivot axis 50. As shown, the distal end 74 is cantilevered beyond the pivot axis 50 of slider 20 to provide desired pitch stiffness relative to load button 48 at pivot axis 50. The extent or length of the

flexure arms 62, 64 tends to decrease the pitch stiffness based upon the width and

thickness of the flexure arms 62, 64. The extent between the proximal and distal ends

72, 74 is sufficient so that when mounting tab 66 is coupled to the upper surface of the slider 20 and load button 48 is aligned generally at the center portion 59 of the slider 20,

a portion of the flexure arms extends beyond pivot axis 50 to provide sufficient pitch stiffness for desired fly characteristics.

As shown, the length of the flexure arms 62, 64 is designed so that when the

mounting tab 60 is secured to the load beam 36 and load beam 36 is positioned so that

the load button supplies a load force to the center portion 59 of the slider, the distal end 74 extends beyond the pivot axis 50 but does not extend along the entire rear portion 56 to the trailing edge of the slider 20. The shortened length provides increased gimbal

resonance frequencies for bending or torsion of the gimbal as compared to flexure arms having a greater flexure length for movably supporting the slider relative to the pivot

axis 50. The design also provides a reduced width and offset flexure arms 62, 64 having lower roll stiffness.

As shown, mounting tab 66 couples the distal end 74 of flexure arms 62, 64 to slider 20. For an optimal disc drive system, placement of mounting tab 66 is

restricted by the SIL 24. In the embodiment shown, the SIL 24 is supported in the rear portion 56, thus interferes with placement of mounting tab 66 in alignment with the distal end 74 of flexure arms 62, 64.

Thus as shown, the distal ends 74 of flexure arms 62, 64 are coupled to a proximally spaced mounting tab 66 via bridges 76, 78. Bridges 76, 78 extend at a sloped

angle 80 to connect distal ends 74 of flexure arms 62, 64 to the proximally spaced mounting tab 66. The sloped design of bridges 76, 78 provides a direct connection

between distal end 74 of flexure arms 62, 64 and mounting tab 66 which does not require additional width between arms 62, 64. The angled relation between distal end

74 and bridges 76, 78 defines a gap 82 between flexure arms 62, 64 and bridges 76, 78

for desired flexure of the gimbal spring. Side 82 of bridges are preferably curved to the

contour of the SIL for placement close to the SIL and a side 86 of the mounting tab 66 is also curved to the contour of the SIL. The length of the flexure arms from axis 50 to

distal end 74 is very critical in providing a pitch stiffness low enough to allow proper flying characteristics. The curved shape of the flexure mounting tabs or bridges 76, 78

allows this increased length. Thus, as described, the gimbal spring 40 of the present invention is not limited to the shape of the particular mounting tab 66 shown; alternately designed mounting tabs

66 may be designed to secure the flexure arms 62, 64 relative to the slider 20. If there is not sufficient area, SIL 24 will restrict placement of the load button 42 toward the center of slider 20. Preferably, the load button 48 is formed by an etching process. The load button or dimple 48 formed by the etching process requires less surface area to

form the dimple than traditionally formed dimples. Thus, the load button 48 formed by the etching process limits the contact to the slider 20 and provides sufficient surface area to mount the mounting tab 66 and wire termination pads relative to the upper surface 31 of the slider 20.

Figure 4 is a cross-sectional view taken along line 4—4 of Figure 3 and illustrates load button 48. As shown, the load button 48 is formed by an etching process

as previously explained where material on a lower surface 80 of the load tab 46 is etched to form a dimple, and then an upper surface 82 of the load tab 46 is pressed to form recessed portion 84 and extend load button 48 by known manufacturing techniques. The

curved region 86 (shown in Figure 3) facilitates press forming recessed portion 84 to form and vertically locate extended load button 48.

Thus, as described, the bridge design of the present invention illustrates the

shape of a preferred embodiment of the gimbal spring 40 of the present invention.

In summary, in addition to significantly lower roll stiffness, the new gimbal

design also greatly increases the resonance frequencies of the gimbal resonance modes. The reduced roll stiffness is further aided by reducing the thickness of the gimbal from

0.0015" to 0.001" and reducing the width of the arms 62, 64. However, if these were

the only changes, the gimbal would probably have unacceptably low gimbal resonance frequencies. To overcome this problem, the bond or slider mounting pad 66 was moved

from the trailing edge of the lens 24 to the leading edge. This reduced the length of the gimbal arms 62, 64 and greatly increased the resonance frequencies of the gimbal modes.

If the gimbal arms 62, 64 are shortened too much, the entire length of the

gimbal arms would be on the leading edge side of the load point. It is highly desirable for pitch stiffness to have some length of the gimbal arms on both sides of the load point.

To accomplish that with this design, a unique feature was incorporated. The unique feature is the circular shape or edge to the bond pad. The circular shape follows the profile of the objective lens 24 and allows the gimbal arms 62, 64 to be extended past the load point towards the trailing edge of the slider. In Figure 3, if the straight lead

edge 69 of the bond pad 66 were extended straight out until it intersected the gimbal arms 62, 64 the region 73 would be filled in and solid. As a result, the pitch stiffness would be approximately 50% higher.

.Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form

and detail without departing from the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A gimbal spring adapted to flexibly support a slider relative to a disc

surface for operation comprising: a base mounting portion adapted to operably connect the gimbal spring

relative to a load beam and thereby to an actuation system; opposed spaced flexure arms extending from the base, said flexure arms being formed of elongated members each having a proximal end and a distal end defining an elongated extent therebetween, said proximal end being operably coupled to the base

and said distal end being cantilevered relative to the base;

a mounting tab adapted to connect to a slider, said mounting tab being positioned between the spaced flexure arms and ends of the mounting tab being spaced a distance from said flexure arms; and bridge sections adapted to connect the distal ends of the flexure arms to the mounting tab, the bridge extending from the distal end of the flexure arms toward the proximal end at a sloped angle relative to said flexure arms to connect a distal end of the

flexure arm relative to the mounting tab.

2. The gimbal spring of claim 1 wherein the gimbal spring is adapted to support a slider supporting an optical lens.

3. The gimbal spring of claim 2 wherein the mounting tabs include

opposed sides, one of said sides having concave shape to contour to an SDL.

4. The gimbal spring of claim 2 wherein said bridge includes opposed sides extending between opposed ends of the bridge, one of said sides having a concave shape to contour to an SIL.

5. In a head suspension assembly including a load beam supporting a gimbal spring having a load button at an extended end of the gimbal, a slider having a

leading edge and a trailing edge, said gimbal spring having a base mounting portion operably coupled to the load beam and a mounting tab operably coupled to the slider,

and opposed spaced flexure arms each having a proximal end and a distal end, the proximal end of the flexure arms being coupled to the base mounting and the mounting tab being operably coupled to a distal end of the flexure arms to flexibly support the slider relative to the load beam, the gimbal spring being coupled to the load beam and

adapted to support the slider so that the load button provides a load force to the slider at a pivot axis of the slider relative to the gimbal spring, wherein the improvement comprises;

the extent of the flexure arms between the proximal and distal end being sized

to extend along a portion of the slider from the leading edge of the slider to a position

distal of the pivot axis and proximal of the trailing edge of the slider.

6. The head suspension assembly of claim 5 wherein the pivot axis is

positioned in a center portion of the slider between the leading and trailing edges.

7. The head suspension assembly of claim 5 wherein the gimbal spring

is adapted to support the slider supporting an optical lens.

8. The head suspension assembly of claim 5 wherein the mounting tab

is positioned proximal of the distal end of the flexure arms and is operably coupled to

the distal end of the flexure arms by bridges extending from the distal end of the flexure arms toward the proximal end at a sloped angle relative to the flexure arm to connect a

distal end of the flexure arm relative to the mounting tab.

9. The head suspension assembly of claim 8 wherein the mounting tab includes opposed sides, one of said sides having a concave shape to contour to the perimeter of an optical lens and the mounting tab being coupled to the optical lens.

10. The head suspension assembly of claim 9 wherein the bridge includes

opposed sides extending between opposed ends of the bridge, one of said sides having a concave shape to contour to the perimeter of an optical lens.

11. The head suspension assembly of claim 5 wherein the mounting tab

is coupled to the slider at the pivot axis.

12. The head suspension assembly of claim 11 wherein the mounting tab

is an elongated rectangular shaped member having opposed ends adapted to couple to

an upper surface of the slider and extending between opposed sides of the slider where

opposed ends are aligned with opposed sides of the slider, and where the mounting tab

is depressed relative to a plane established by said flexure arms.

13. In a head suspension assembly including a load beam supporting a gimbal spring having a load button at an extended end of the gimbal, a slider having a leading edge and a trailing edge, said gimbal spring having a base mounting portion operably coupled to the load beam and a mounting tab operably coupled to the slider, and opposed spaced flexure arms each having a proximal end and a distal end, the

proximal end of the flexure arms being coupled to the base mounting and the mounting

tab being operably coupled to a distal end of the flexure arms to flexibly support the slider relative to the load beam, the gimbal spring being coupled to the load beam and adapted to support the slider so that the load button provides a load force to the slider

at a pivot axis of the slider relative to the gimbal spring, wherein the improvement comprises:

means for supporting the slider and allowing pitch and roll around and along said pivot axis.

14. A head suspension assembly as claimed in claim 13 wherein said

supporting means comprise bridge means having an edge distal from the load beam and

conformed to curvature of an optical lens.

AMENDED CLAIMS

[received by the International Bureau on 16 December 1998 ( 16.12.98) ; original claims 1 and 5 amended ; remaining claims unchanged (2 pages) ]

1. A gimbal spring adapted to flexibly support a slider relative to a disc surface for operation comprising: a base mounting portion adapted to operably connect the gimbal spring relative to a load beam and thereby to an actuation system; opposed spaced flexure arms extending from the base, said flexure arms being formed of elongated members each having a proximal end and a distal end defining an elongated extent therebetween, said proximal end being operably coupled to the base and said distal end being cantilevered relative to the base; a mounting tab adapted to connect to a slider, said mounting tab being positioned between the spaced flexure arms and ends of the mounting tab being spaced a distance from said flexure arms; and bridge sections adapted to connect the distal ends of the flexure arms to the mounting tab, the bridge extending from the distal end of the flexure arms toward the proximal end at a sloped angle relative to said flexure arms to connect a distal end of the flexure arm relative to the mounting tab; and wherein the mounting tab is an elongated rectangular shaped member having opposed ends adapted to couple to an upper surface of the slider and extending between opposed sides of the slider where opposed ends are aligned with opposed sides of the slider, and where the mounting tab is depressed relative to a plane established bv said flexure arms.

3. The gimbal spring of claim 2 wherein the mounting tabs include opposed sides, one of said sides having concave shape to contour to an SIL.

5. In a head suspension assembly including a load beam supporting a gimbal spring having a load button at an extended end of the gimbal, a slider having a leading edge and a trailing edge, said gimbal spring having a base mounting portion operably coupled to the load beam and a mounting tab operably coupled to the slider, and opposed spaced flexure arms each having a proximal end and a distal end, the proximal end of the flexure arms being coupled to the base mounting and the mounting tab being operably coupled to a distal end of the flexure arms to flexibly support the slider relative to the load beam, the gimbal spring being coupled to the load beam and adapted to support the slider so that the load button provides a load force to the slider at a pivot axis of the slider relative to the gimbal spring, wherein the improvement comprises; the extent of the flexure arms between the proximal and distal end being sized to extend along a portion of the slider from the leading edge of the slider to a position distal of the pivot axis and proximal of the trailing edge of the slider; wherein the mounting tab is an elongated rectangular shaped member having opposed ends adapted to couple to an upper surface of the slider and extending between opposed siues of the slider where opposed ends are aligned with opposed sides of the slider, and where the mounting tab is depressed relative to a plane established hv said flexure arms.