Rigid magnetic recording media are used for recording and retrieving digital data in computer disc drive devices. During fabrication of thin-film magnetic recording discs, hereinafter magnetic discs or discs, there are two important handling requirements that must be met in fabricating high quality discs. First, the work area must be free of contaminants, such as dust and other air-borne particles; second, the discs must be protected from physical damage that may occur as the discs are being handled.
Typically, the fabrication of the magnetic discs is done is a clean room, where the level of contamination is kept very low. The discs may be kept under laminar flow hoods during much of the processing, and handling and exposure to human operators is minimized.
Fabricating magnetic discs involves many steps: unloading the disc substrates from a carrier cartridge, placing the substrates into a flow-through sputtering pallet which is oriented in a vertical plane and contains numerous disc holding grooves, where thin-film layers forming the recording medium are deposited on the substrate, transferring the discs from the film-deposition apparatus to one or more stations where the disc surfaces are lubricated, and then packaged for shipment. It is essential during the disc-handling steps, that the disc surfaces be protected from any surface damage. A variety of disc-handling devices, such as mandrels, have been proposed or developed for use in transferring individual discs or groups of discs. See, for example, U.S. Pat. Nos. 4,865,509; 4,290,734; 4,957,406; 4,787,806; 4,735,540; 4,645,401; and 5,131,800. Many of these devices involve moving parts, which introduce the possibility of mechanical breakdown and abrasion of the disc surfaces due to moving parts. Other devices which have a unitary construction may have difficulty in handling discs without damage, due to thickness and/or radial-dimension variations among discs, or variations in the spacing between adjacent discs.
USPTO Backgrounds
USPTO Backgrounds