Abstract: A method for manufacturing a disk includes the step of forming a first nickel-phosphorus alloy layer on an aluminum substrate, e.g., by electroless plating. A second nickel-phosphorus layer is then sputtered onto the first nickel-phosphorus layer, and a magnetic alloy is sputtered onto the second nickel-phosphorus layer. The magnetic alloy is typically sputtered immediately after the second nickel-phosphorus layer is formed without removing the disk from the sputtering apparatus between the time the second nickel-phosphorus layer is formed and the time the magnetic alloy is formed. Because of this, contaminants are not capable of lodging on or affecting the surface of the disk prior to formation of the magnetic alloy. The second nickel-phosphorus layer is typically amorphous and therefore masks any nonuniformities in the surface of the first nickel-phosphorus layer.

Abstract: A film of magnetic recording media is formed by sputtering an alloy of cobalt and platinum onto a substrate. The sputtering takes place in a chamber containing argon and nitrogen. The magnetic coercivity of the resulting film is controlled by varying the concentration of nitrogen in the sputtering chamber. By using this technique, the film coercivity is controlled without varying other important parameters such as the saturation magnetization.

Abstract: A carrier is provided to hold a centrally apertured disk while magnetic material is coated simultaneously on the two surfaces of the disk. A carrier includes a plate which contains a first opening through the plate slightly smaller than the disk diameter and a second opening partially through the plate formed about a center line offset from the center line of the first opening to form a recess around an upper portion of first opening edge. The disk is directed into the recess and first opening and then lowered into a groove at the bottom of the first opening. The groove and recess in conjunction with the disk edges block flow of plasma and impurities from one side of the disk to the other during simultaneous coating of magnetic media on the disk surfaces. A two-part plug is placed in the disk center aperture, one part containing a spring or magnet for holding the two parts together in the disk. The plug also serves as a handle by which the disk can be carried, mounted in or removed from the carrier.

Abstract: A robotic system includes a series of cassettes holding blank centrally apertured disks which are ejected in seriatim from each cassette and a plug inserted into the disk central aperture by manipulation of a robotic arm at that cassette position. Each disk is transported by the robotic arm and inserted into a series of disk-holding apertures in a carrier panel and, after processing of multiple disks in the panel, the processed disks are removed from the carrier panel by the robotic arm to a second cassette position where the plugs are removed from the processed disk and the plugs conveyed by a pair of robotic arms or by the robotic arm acting in conjunction with an auxiliary robotic arm for reinsertion into other blank disks. Sensors are provided for accurately positioning the robotic arm with respect to the position of the carrier panel to be loaded.

Abstract: A carrier is provided to hold a central apertured disk while magnetic material is plated simultaneously on the annular surfaces on both sides of the disk. The carrier contains a first opening substantially the same diameter as the disk and a second opening formed about a center line offset from the center line of the first opening so as to form a recess around a portion of the edge of the first opening. The disk is inserted into the first opening and recess to block the flow of plasma and impurities from one side of the disk to the other during the disk surface coating. A two-part plug is provided for placement in and sealing the center aperture of the disk. One plug part contains a spring or magnetic means for holding the two parts together within the disk. The plug includes a knob for handling, carrying and mounting or removing the disk from the carrier.

Abstract: A carrier is provided to hold a disk while magnetic material is plated simultaneously on the two surfaces of the disk. The carrier contains a first opening substantially the same diameter as the disk and a second opening formed about a center line offset from the center line of the first opening so as to form a recess around a portion of the edge of the first opening. The recess allows the disk to be mounted into the carrier by placing the disk in a portion of the first opening and in a portion of the recess without having a surface of the disk touch the surface of the recess. The disk is then lowered into the first opening while leaving the remainder of the carrier material adjacent the recess to block the flow of plasma and impurities from one side of the disk to the other during the coating of the surfaces of the disk with magnetic media. A plug is provided for placement in the center hole of the disk.