Abrading – Machine – Stationary tool
Reexamination Certificate
2003-01-03
2004-09-14
Nguyen, George (Department: 3723)
Abrading
Machine
Stationary tool
C451S312000, C451S317000, C029S090010, C360S245000, C073S105000
Reexamination Certificate
active
06790133
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to magnetic disk manufacturing equipment. More particularly, the present invention relates to a suspension assembly for holding a glide and burnish slider.
BACKGROUND OF THE INVENTION
Magnetic disks are commonly used in computer hard drives. The magnetic disks are burnished and surface-tested before they are installed into the hard drive package. The glide and burnish process is performed by moving a glide/burnish slider across the surface of the hard disk. Hard disks are currently manufactured in accordance with the newer 30% format that requires smaller glide and burnishing sliders and smaller read/write heads. In this context, 30% refers to the approximate linear dimensions of the slider relative to the standard “full size” or 100% slider, which was introduced in the year 1981. A full size slider has a length of 160 mils; a width of 125 mils, and a height of 35 mils. In contrast, a 30% slider (introduced in 1994) has a length of 49 mils, a width of 39 mils, and a height of 12 mils. The length, width, and height dimensions of a 50% slider are 80 mils, 63 mils, and 17 mils, respectively, and the length, width, and height dimensions of a 70% slider are 112 mils, 88 mils, and 24 mils, respectively.
The smaller 30% glide/burnish sliders are conventionally mounted to Type-8 suspensions that are specifically configured to provide increased stability and head placement relative to older Type-2 suspensions. For example, Type-8 suspensions are shorter than Type-2 suspensions. As used herein, the “Type” is an industry-accepted term that defines specific physical, mechanical, and operating characteristics of suspensions designed for deployment in a hard disk drive. The various Type designators are also used to distinguish different classes of suspensions designed for deployment in glide/burnish applications.
Type-2, Type-4, and Type-8 suspensions are individual and progressive designs that vary according to their respective basic requirements. These basic designs are then expanded in the final assembly process to accommodate the various read/write glide or burnish sliders (e.g., 70%, 50%, or 30% sliders), according to the final intended use of the assemblies. This accommodation is accomplished by alternate design and material thickness changes in the required individual gimbal sub-assembly, subsequently attached to the original basic load beam and mount design during final suspension assembly. For example, typical gimbal material thickness is 0.002 inch for 70% sliders, 0.0015 inch for 50% sliders, and 0.0012 inch for 30% sliders. Thus, the different suspension types are produced in their own unique basic design configurations, with the addition of individual gimbal assemblies, designed to carry different sized sliders as required (or all optional combinations).
Newer test fixtures and tooling are compatible with the Type-8 suspension format, thus enabling effective glide and burnishing of hard disks with 30% sliders. However, older tooling and equipment for glide and burnishing heads are typically configured to only accommodate the outdated Type-2 suspension format (Type-2 suspension technology is approximately 20 years old). For example, a Type-2 suspension includes two mounting holes for mounting the suspension to the test fixture; two screws or bolts are used to mount each Type-2 suspension. In contrast, the later design Type-8 suspension utilizes a single mounting boss with a swage hole that receives a test fixture location pin or swaging ball to facilitate an interference fit engagement. A plurality of Type-8 suspensions can be mounted to the test fixture or drive actuator assembly using only one swage mounting ball.
Unfortunately, existing Type-2 suspension assemblies cannot be effectively retrofitted to accommodate 30% glide and burnishing sliders; the Type-2 suspensions, which are designed to hold 70% sliders, do not provide adequate stability and rigidity for the smaller 30% sliders. Consequently, users of older equipment must either purchase new equipment compatible with Type-8 glide and burnishing suspensions, or modify their existing tooling to accommodate the Type-8 suspensions. Either solution can be extremely cost prohibitive.
BRIEF SUMMARY OF THE INVENTION
A glide and burnishing suspension configured in accordance with the present invention can utilize a 70%, 50%, 30%, or smaller size glide and burnishing slider on a suspension load beam that is otherwise compatible with test fixtures designed to only accommodate Type-2 suspensions. The glide and burnishing suspension with the appropriate 70%, 50%, 30%, or smaller gimbal provides the requisite structural stability and rigidity necessary to support the above mentioned glide and burnishing sliders, i.e., the glide and burnishing suspension exhibits the stability of newer Type-8 suspensions. The glide and burnishing suspension serves as a direct retrofit replacement for existing Type-2 glide and burnishing suspensions utilized in older test equipment and/or tooling.
The above and other aspects of the present invention may be carried out in one form by a magnetic disk glide/burnish suspension loadbeam that includes at least a mounting end having mounting holes formed therein, a gimbal end opposite the mounting end, a tapered section between the mounting end and the gimbal end, and a tooling hole formed within the tapered section. The gimbal end is configured to receive a glide/burnish slider, the tapered section is Type-8/Type-20 compatible, and the tooling hole and the mounting holes are Type-2/Type-4 compatible.
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Acropolis Engineering Inc.
Gray Cary Ware & Freidenrich LLP
Nguyen George
LandOfFree
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