Abstract: A fluid jet cutting method and apparatus for cutting an object from a sheet. In one embodiment, a fluid jet stream is directed against a glass sheet to cut an annular disk substrate for use in a data storage device. The sheet is supported by first, second and third support members. The support surfaces of the second and third support members are respectively positioned inside central openings in the first and second support members. A vacuum pulls the sheet against the support surface of at least the second support member. Preferably, plural central openings in the first support member accommodate plural second and third support members, whereby plural substrates are cut from the sheet. The sheet preferably includes plural layers removably adhered to one another, whereby plural substrates are simultaneously formed by a single fluid jet stream. A protective layer may cover at least one surface to the sheet.

Abstract: An apparatus and method of reclaiming a disk substrate. The cost of reclaiming a disk substrate can be lower, and the quality higher, than making a new one from a blank. A layer of a data storage disk is stripped, e.g., by acid/oxidizing bath immersion. The stripped disk is polished in a carrier between polishing pads, with the relative velocity of the polishing pads as seen by the disk being precisely controlled so that an equal amount of stock is removed from each side. Preferably, several stripped disks are sorted into groups based on disk thickness, and disks from one of the groups are simultaneously polished in the carrier. Sorting improves stock removal uniformity from disk to disk. The polished disks are cleaned and, preferably, ordered in a cassette for stacking in a storage device based on disk thickness to more easily meet a mean center specification.

Abstract: An abrasive fluid jet cutting composition, method and apparatus for cutting an object from a sheet. In one embodiment, a fluid jet stream is directed against a glass sheet to cut a disk substrate for use in a data storage device. An abrasive slurry is delivered to a fluid jet head from a slurry tank. The slurry is formed by mixing water, abrasive particles, a surfactant or surfactants, and an acid or base. The head also receives a pressurized fluid from a fluid pump. The abrasive slurry and the pressurized fluid are mixed in the head to form the fluid jet stream. Preferably, the abrasive particles are 8-64 microns and may include recycled scrap. The slurry may also contain polishing particles that are smaller than the abrasive particles to affect polishing. In addition to reducing surface tension, the surfactant may cause the abrasive particles to flocculate or disperse.

Abstract: A fluid jet cutting method and apparatus for cutting an object from a sheet. In one embodiment, a fluid jet stream is directed against a glass sheet to cut an annular disk substrate for use in a data storage device. The sheet is supported by first, second and third support members. The support surfaces of the second and third support members are respectively positioned inside central openings in the first and second support members. A vacuum pulls the sheet against the support surface of at least the second support member. Preferably, plural central openings in the first support member accommodate plural second and third support members, whereby plural substrates are cut from the sheet. The sheet preferably includes plural layers removably adhered to one another, whereby plural substrates are simultaneously formed by a single fluid jet stream. A protective layer may cover at least one surface to the sheet.

Abstract: A dressing disk for dressing and reconditioning the polishing pad of a planetary disk polishing machine is fabricated by plating a nickel/diamond matrix layer onto a stainless steel disk wherein the matrix layer thickness is developed or plated to a thickness which leaves exposed about 25 percent of the fine diamond particles, thereby forming a surface that has the look and feel of medium to coarse sandpaper. The dressing disks are inserted into the holes in a disk carrier of a planetary polishing machine and driven by its central rotary drive.

Abstract: The invention is a method for improving the flatness of nonmetallic substrates and preferably glass disks. The method comprises the steps of mounting the glass disk on a support. The support preferably comprises a refractory metal having a cooling rate substantially similar to the disk. The disk is then subjected to heating to a temperature in the anneal region for the given material for a period ranging from about 0.5 hours to 12 hours or longer, and then the disk is controllably cooled. The glass disk is preferably cooled at a rate of about 0.25.degree. C./minute to 1.5.degree. C./minute to room temperature. The invention also comprises a hard disk glass memory element and a data storage and retrieval device comprising this element.

Abstract: An improved method and formulation is shown for preparing polishing media for superfinishing pure metal surfaces. A combination of hydrophobic and hydrophilic silicone surfactants is used to control the porosity and water absorption during use whereby durability is obtained and the catalyst concentration is regulated to control hardness to achieve durability without scratching the workpiece. Density is controlled by the quantity of mixture with which a closed mold is charged. To produce successful media it is also necessary to preheat the closed mold and to be certain that the resin mixture of particles, polyol and additives does not exceed 120 degrees F. prior to final mixture with isocyanate just before charging the mold and curing. Also a longer cure at a lower temperature enhances the qualities of the resulting polishing media.