Patent Grant
7466517
The present invention relates generally to laminates, and in particular to an integral, continuous laminate, such as may be comprised in a suspension.
Suspensions for small disc drives have typically been made in a three piece form or a four piece form. In a typical three piece construction, a thick arm is welded to a thin beam in a pre-load region, and a gimballed portion is mounted to the thin beam. In a typical four piece construction, a thick arm is attached to a pre-load bend region which in turn is attached to a beam with formed rails, onto which a gimballed portion is mounted.
Data storage devices have tended to be made smaller, yet with greater storage capacity, over time. Some applications have led to interest in “micro” disc drives, such as those that are one inch or smaller, and a fraction of an ounce, such as might be well suited to hand-held or otherwise easily portable devices, such as small music players, PDAs, digital still and video cameras, or external computer memory, for example. Adapting data storage technology to excel in current applications poses considerable technical challenges.
Embodiments of the present invention provide unforeseen advantages over typical suspensions, including promising application in novel data storage systems.
One embodiment of the present invention provides a unified suspension that includes an integral, continuous laminate, which has a thick actuator arm portion, a thin pre-load portion, and a beam portion, all formed of the same single laminate. The pre-load portion is integrally connected to the actuator arm portion, is thinner than the actuator arm portion, and is configured to apply a pre-load force. The beam portion is integrally connected to the pre-load portion, and is configured for attaching a gimbal to it. This integral, continuous laminate substantially lowers the mass of the suspension, provides excellent shock, resonance and lift tab performance, lowers power consumption requirements, and simplifies the complexity and cost of manufacturing components for a suspension and for assembling the components of the suspension together and into a larger system of which the suspension is a part.
Another embodiment of the present invention pertains to a suspension that includes an integral, continuous laminate and a gimbal. The integral, continuous laminate includes an actuator arm portion, a pre-load portion, a beam portion, and a lift tab portion. The pre-load portion is integrally connected to the actuator arm portion, and is thinner than the actuator arm portion. The beam portion is integrally connected to the pre-load portion, and includes means for attaching the gimbal to it. The lift tab portion is integrally connected to the beam portion. The actuator arm portion, the pre-load portion, the beam portion, and the lift tab portion jointly form a single integral and continuous component. The gimbal is mounted on the beam portion.
Another embodiment of the present invention pertains to a data storage system. The data storage system includes a deck, a media surface configured to be rotatably mounted adjacent to the deck, a suspension being rotatably mounted on the deck, and a head-bearing slider. The suspension includes an integral, continuous laminate and a gimbal mounted on the laminate, with the slider being mounted on the gimbal. This configures the slider to be suspended from the gimbal above the media surface. The integral, continuous laminate is selectively etched to form an actuator arm portion, a pre-load portion, and a beam portion. The pre-load portion is integrally connected to the actuator arm portion, and the beam portion is integrally connected to the pre-load portion. The pre-load portion is thinner than the actuator arm portion, and is configured to apply a pre-load force toward the media surface. The beam portion is configured for attaching the gimbal to it.
Other features and benefits that characterize various embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings.
Suspension 1 is thereby ideal for use, for example, in a “micro” drive, and in applications in which extremely low mass, low power consumption, and good shock performance are high priorities. In addition, suspension 1 includes only two parts: integral laminate 10 and gimbal 20, requiring only one attachment step such as a weld between compatible sections, or some other means for attaching gimbal 20 to beam portion 16 of laminate 10, in this illustrative embodiment. The inherent ease and simplicity of manufacture of laminate 10, as a single, integral part, therefore provide for substantial cost savings.
Laminate 10 is integral, for example, in the sense that it is a single, whole component, or that it was manufactured as a single piece, in this illustrative embodiment. Laminate 10 is also continuous, for example, in the sense that its length can be traversed along a continuous path, without having to pass by a discontinuity, or a section where two separate components were joined together at a seam, in this embodiment. The continuous laminate is stronger and lighter in a given section than a comparable section with a seam or attachment mechanism in an otherwise similarly configured, typical laminate. The actuator arm portion 12, the pre-load portion 14, the beam portion 16, and the lift tab portion 18 thereby jointly form a single integral and continuous component, in this embodiment.
Pre-load portion 14 is thinner than actuator arm portion 12, in this illustrative embodiment. Pre-load portion 14 is configured to apply a pre-load force on the beam portion 16, in a downward direction as indicated by vector 22, for example, in this embodiment. Beam portion 16 is configured for attaching gimbal 20 to it. A head-bearing slider (not depicted in
The integral, continuous laminate 10 includes an upper layer 30 made of a metal, a central layer 32 made of a polymer, and a lower layer 34 made of the metal, in this illustrative embodiment. For example, the metal forming the upper and lower layers 30, 34 may consist of stainless steel, while the central layer 32 may consist of polyimide, in this embodiment. This combination of layers forming laminate 10 provides substantial performance advantages. For example, the stainless steel provides excellent strength and rigidity on the outer layers of laminate 10, while the polyimide provides a strong central layer with high durability and a low coefficient of thermal expansion, among other advantages. Other types of materials may be used in the layers of the laminate 10, such as titanium, carbon fiber, various other polymers or resins, or other materials.
Certain portions of these three layers of laminate 10 are selectively removed, in this illustrative embodiment. Such selective removal may have been achieved by selective etching, for example. In particular, the upper layer 30 and the central layer 32 of the laminate are selectively removed in the pre-load portion 14 and in the beam portion 16, in this embodiment. In contrast, the actuator arm portion 12 and the lift tab portion 18 include all three layers of the laminate through much of their area, making them thicker than the pre-load portion 14 and the beam portion 16, in this embodiment. The greater thickness of laminate 10 in actuator arm portion 12 advantageously provides the appropriate stiffness for higher natural frequencies of the suspension 1, in this embodiment. At the same time, the relative thinness of the pre-load portion 14, etched down to the thin bottom stainless steel layer 34 of the laminate 10, advantageously provides a very low spring rate for pre-load portion 14, in this embodiment.
The beam region 16 is also etched down to the thin bottom stainless steel layer 34 of the laminate 10, in this illustrative embodiment. Additionally, stiffening rails 24, 26 are formed on the edges of beam region 16, providing low mass and high stiffness, contributing thereby to advantageous operative shock and resonance performance of the suspension 1, in this embodiment. The rails 24, 26 are defined by the lateral edges of beam portion 16 disposed at an angle relative to a axially centroidal section 28 of the beam portion 16. The axially centroidal section 28 runs generally along the long axis of beam portion 16, generally from the central section of pre-load portion 14 on one end to the central section of lift tab 18 on the other end, that is, generally along the centroid of beam portion 16. Whereas the axially centroidal section 28 can be defined as being relatively flat, rails 24, 26 are both angled upward from that flat dimension of axially centroidal section 28, thereby providing enhanced stiffness and rigidity to beam portion 16, particularly in the up-and-down dimension, in this embodiment, with reference to vector 21 defined as the up direction, and again to vector 22 defined as the down direction.
In some sections of laminate 10, the upper layer, the central layer, and the lower layer are all selectively removed in one or more sections in the integral, continuous laminate 10, thereby defining mass reduction features 40 in laminate 10, in this illustrative embodiment. (Reference number 40 indicates a representative sampling among a larger number of mass reduction features in integral, continuous laminate 10.) Mass reduction features 40 occur in the actuator arm portion 12, the pre-load portion 14, and the beam portion 16, in this embodiment. Mass reduction features 40 reduce the overall mass of suspension 1, while they are placed in regions of laminate 10 that are relatively unimportant compared to the mechanical stresses experienced by laminate 10, such that the removal of the material in the mass reduction features 40 doesn't have a significant effect on the stiffness and rigidity of suspension 1. Additionally, mass reduction features 40 provide better shock performance, particularly mass reduction features 40 in beam region 16, in this embodiment.
Lift tab portion 18 is integrally connected on one end to the beam portion 16, while a section of the lift tab portion 18 extends upwardly from the beam portion 16, in this illustrative embodiment. The lift tab portion 18 is configured to controllably provide an upward force on beam portion 16, sufficient to selectively lift suspension 1, along with a head-bearing slider mounted on a gimbal 20, attached to beam portion 16, away from a media surface. (“Upward” is again defined as indicated by upward vector 21, in this illustrative embodiment.) Forming the lift tab portion 18 also from the structure of laminate 10, including all three layers 30, 32, 34, provides lift tab portion 18 of laminate 10 with excellent stiffness, such as would not possible where very thin beams are used for a lift tab. The high stiffness of lift tab 18 is highly advantageous in ensuring good shock-resistant performance, particularly in an application in which suspension 1 is incorporated into a storage device in a mobile or portable device. Suspension 1 thereby incorporates a thin beam portion 16 with a particularly low mass and good shock and resonance performance, while maintaining high stiffness in the lift tab portion 18, in a single continuous, integral laminate 10 with a simplified manufacturing process and reduced cost, in this embodiment.
Lift tab portion 218 demonstrates a substantial aspect of the embodiment of
Some experimental measurements were taken in a performance test, in which embodiments similar to those of
As is apparent from these results, the embodiments have dramatically lower mass than the representative conventional suspension; they have a greater overall spring rate, lower values for static shock to lift-off and first bend, greater values for first torsion and second torsion, lower values for sway, and dramatically greater values for lift tab stiffness. These results indicate some of the unexpected advantages of the integral, continuous laminate of the respective embodiments. For example, the greatly superior lift tab stiffness demonstrates the surprising advantages from combining different numbers of laminate layers along the axial length of the lift tab portion of the integral, continuous laminate, as described herein.
In
Slider 320 has a read/write head mounted thereon, configured thereby to be suspended above disc surface 328. The read/write head on head-bearing slider 320 is capable of reading data from and writing data to disc surface 328, in this illustrative embodiment. The read/write heads may be of any type known in the art, including magnetic, magnetoresistive, giant magnetoresistive (GMR), optical, and so forth, in various embodiments. In different embodiments, a wide variety of numbers of discs, with a corresponding number of read/write heads and head-bearing sliders, may occur.
Suspension 310 includes an integral, continuous laminate, and a gimbal (not individually depicted in
As described with respect to the other embodiments discussed above, the integral, continuous laminate of suspension 310 includes an upper layer comprising a metal, a central layer comprising a polymer, and a lower layer comprising the metal, in this illustrative embodiment. The upper layer and the central layer are selectively removed, such as by selective etching, in the pre-load portion and in the beam portion, to achieve desired characteristics of rigidity, stiffness, and low mass, among various other advantages such as those described with respect to the embodiments of
The present invention therefore includes unexpected and novel advantages as detailed herein and as can be further appreciated from the claims, figures, and description by those skilled in the art. Although some of the embodiments are described in reference to a data storage system, the present invention has various other embodiments with application to other applications of suspensions and of laminates.
It is to be understood that even though numerous characteristics and advantages of various illustrative embodiments of the invention have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention, to the full extent indicated by the broad, general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to a family of systems, devices, and means encompassed by and equivalent to the examples of embodiments described, without departing from the scope and spirit of the present invention. Further, still other applications for various embodiments, including embodiments pertaining to integral, continuous laminates and data storage systems, are possible.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5187625 | Blaeser et al. | Feb 1993 | A |
| 5296983 | Blanc et al. | Mar 1994 | A |
| 5712748 | Masse | Jan 1998 | A |
| 5734524 | Ruiz | Mar 1998 | A |
| 5835310 | Battu | Nov 1998 | A |
| 5856896 | Berg | Jan 1999 | A |
| 5936806 | Pan et al. | Aug 1999 | A |
| 5955176 | Erpelding et al. | Sep 1999 | A |
| 6046884 | Crane | Apr 2000 | A |
| 6046887 | Uozumi et al. | Apr 2000 | A |
| 6078473 | Crane et al. | Jun 2000 | A |
| 6108170 | Crawforth | Aug 2000 | A |
| 6147840 | Khan | Nov 2000 | A |
| 6157520 | Mangold | Dec 2000 | A |
| 6191915 | Takagi et al. | Feb 2001 | B1 |
| 6201666 | Resh | Mar 2001 | B1 |
| 6215622 | Ruiz et al. | Apr 2001 | B1 |
| 6266214 | Khan | Jul 2001 | B1 |
| 6271995 | Fontana et al. | Aug 2001 | B1 |
| 6288873 | Lundquist et al. | Sep 2001 | B1 |
| 6295185 | Stefansky | Sep 2001 | B1 |
| 6324130 | Hatam-Tabrizi | Nov 2001 | B1 |
| 6351353 | Sluzewski et al. | Feb 2002 | B1 |
| 6366430 | Narayan | Apr 2002 | B1 |
| 6377425 | Khan | Apr 2002 | B1 |
| 6381099 | Mei | Apr 2002 | B1 |
| 6385011 | Chang | May 2002 | B1 |
| 6388842 | Murphy | May 2002 | B1 |
| 6388843 | Takagi et al. | May 2002 | B1 |
| 6392843 | Murphy | May 2002 | B1 |
| 6396667 | Zhang | May 2002 | B1 |
| 6417993 | Kant | Jul 2002 | B1 |
| 6424498 | Patterson | Jul 2002 | B1 |
| 6441385 | Khlif | Aug 2002 | B1 |
| 6449127 | Crane | Sep 2002 | B1 |
| 6496327 | Xia | Dec 2002 | B2 |
| 6507463 | Boutaghou | Jan 2003 | B1 |
| 6522503 | Takadera | Feb 2003 | B2 |
| 6556383 | Murphy | Apr 2003 | B2 |
| 6587309 | Nojima | Jul 2003 | B2 |
| 6594115 | Takagi | Jul 2003 | B2 |
| 6597541 | Nishida | Jul 2003 | B2 |
| 6602362 | Tomioka | Aug 2003 | B2 |
| 6627909 | Khlif | Sep 2003 | B2 |
| 6636382 | Shiraishi | Oct 2003 | B2 |
| 6636388 | Stefansky | Oct 2003 | B2 |
| 6650505 | Narayan et al. | Nov 2003 | B2 |
| 6661618 | Fujiwara et al. | Dec 2003 | B2 |
| 6661619 | Nishida et al. | Dec 2003 | B2 |
| 6662069 | Khlif | Dec 2003 | B1 |
| 6687095 | McReynolds et al. | Feb 2004 | B2 |
| 6697226 | Narayan et al. | Feb 2004 | B1 |
| 6700744 | Nishida et al. | Mar 2004 | B2 |
| 6710295 | Tam | Mar 2004 | B1 |
| 6714386 | Polycarpou | Mar 2004 | B1 |
| 6721133 | Takagi | Apr 2004 | B2 |
| 6731465 | Crane | May 2004 | B2 |
| 6731472 | Okamoto | May 2004 | B2 |
| 6735050 | Takagi et al. | May 2004 | B2 |
| 6738226 | Bhattacharya et al. | May 2004 | B1 |
| 6747849 | Le et al. | Jun 2004 | B1 |
| 6765759 | Bhattacharya et al. | Jul 2004 | B2 |
| 6765760 | Saito et al. | Jul 2004 | B2 |
| 6768612 | Hanya et al. | Jul 2004 | B2 |
| 6785094 | Arya et al. | Aug 2004 | B2 |
| 6798618 | Takagi et al. | Sep 2004 | B2 |
| 6801402 | Subrahmanyam et al. | Oct 2004 | B1 |
| 6807029 | Someya et al. | Oct 2004 | B2 |
| 6813119 | Okamoto et al. | Nov 2004 | B2 |
| 6898841 | Shiraishi | May 2005 | B2 |
| 6995954 | Coon | Feb 2006 | B1 |
| 7114238 | Shiraishi | Oct 2006 | B2 |
| 7158348 | Erpelding et al. | Jan 2007 | B2 |
| 7224554 | Wright | May 2007 | B2 |
| 7359157 | Takagi et al. | Apr 2008 | B2 |
| 7375927 | Miller | May 2008 | B1 |
| 7388733 | Swanson et al. | Jun 2008 | B2 |
| 20020109943 | Crane et al. | Aug 2002 | A1 |
| 20020181155 | Takagi et al. | Dec 2002 | A1 |
| 20030007289 | Shiraishi | Jan 2003 | A1 |
| 20030035245 | Shiraishi | Feb 2003 | A1 |
| 20030074782 | Shiraishi | Apr 2003 | A1 |
| 20030202283 | Arya et al. | Oct 2003 | A1 |
| 20030202284 | Arya | Oct 2003 | A1 |
| 20030202285 | Arya et al. | Oct 2003 | A1 |
| 20040228037 | Wada et al. | Nov 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| 9106634 | Apr 1997 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20060285253 A1 | Dec 2006 | US |
