Abstract: A method for the preparation of a mold for use in molding high density information discs includes treating the exposed surfaces of the mold with a solvent to remove any foreign matter therefrom. This step is followed by treating the exposed surfaces of the mold with a cleaning and drying agent to remove any remaining solvent. This is followed by applying a coating of an antistatic agent to the surfaces of the mold. The method is completed by applying a coating of a mold lubricant to the surfaces of the mold.
Abstract: An improved apparatus and method of molding a high density information disc which includes maintaining the molding composition at an elevated temperature between the extrusion step and the record pressing step, such that the resultant disc is of improved quality. A heated shot cup is provided to maintain the extruded molding composition at the elevated temperature and in which the same is molded into a preform from which the disc is pressed.
Abstract: Polyvinyl chloride base molding compositions containing conductive carbon particles which have been treated with a fatty acid chloride have reduced melt viscosities, improved processabilities, and increased electrical conductivities, as well as improved dispersion of the carbon particles in the molding compositions. High density information discs having improved playback performance can be readily molded from these compositions.
Abstract: A method of applying thin metal sensitizing deposits to the exposed silicon areas of a silicon substrate having areas of exposed silicon and silicon oxide, including the steps of immersing the silicon substrate in a basic, aqueous solution containing a metal salt of the metal to be deposited, particularly a nickel, cobalt, or platinum salt, and thereafter reducing the metal ion of the salt to the elemental metal by use of the exposed silicon as the reducing agent.
Type:
Grant
Filed:
February 28, 1980
Date of Patent:
October 27, 1981
Assignee:
RCA Corporation
Inventors:
Richard Denning, Mark A. Spak, Barry Polhemus
Abstract: An etching solution for etching composite structures of silicon nitride on silicon oxide on silicon substrates which etches the silicon nitride at a rate equal to or faster than the silicon oxide which comprises concentrated aqueous hydrogen fluoride in a high boiling, organic solvent.
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