Polishing process for glass or ceramic disks used in disk drive data storage devices

A method for manufacturing a glass or ceramic disk substrate for a rotating disk drive data storage device, comprising the steps of:

• providing a glass or ceramic disk substrate in an unpolished state;
• loading said disk substrate in said unpolished state to a polishing apparatus;
• and
• polishing said disk substrate with said polishing apparatus from said unpolished state to a surface finish having a roughness no greater than 15 Å, as measured by an atomic force microscope, said polishing step being accomplished without intermediate unloading of said disk substrate.

A method for polishing a glass or ceramic disk substrate for a rotating disk drive data storage device, comprising the steps of:

• loading a glass or ceramic disk substrate to a polishing apparatus;
• and
• polishing at least one flat surface of said disk substrate with said polishing apparatus using a polishing slurry composition in a first polishing stage, said polishing apparatus operating at a first pressure during said first polishing stage;
• polishing said at least one flat surface of said disk substrate with said polishing apparatus using said polishing slurry composition in a second polishing stage, said polishing apparatus operating at a second pressure lower than said first pressure during said second polishing stage, said second polishing stage being performed after said first polishing stage and without intermediate unloading of said disk substrate.

A method for manufacturing a glass disk substrate for a rotating disk drive data storage device, comprising the steps of:

• providing a glass disk substrate in an unpolished state;
• loading said disk substrate in said unpolished state to a polishing apparatus;
• and
• polishing said disk substrate with said polishing apparatus from said unpolished state to a surface finish having a roughness no greater than 12 Å, as measured by an atomic force microscope, said polishing step being accomplished without intermediate unloading of said disk substrate.

A polishing apparatus for polishing glass or ceramic disk substrates for use in a rotating disk drive data storage device, comprising:

• a polishing well for containing a plurality of glass or ceramic disk substrates and a polishing slurry;
• a pair of opposed polishing pads for simultaneously polishing opposite surfaces of said plurality of disk substrates;
• a movable pressure plate applying a programmable amount of pressure through a first of said pair of opposed polishing pads, and moving said first pad with respect to a second of said pair of opposed pads to provide polishing action;
• a controller controlling the operation of said polishing apparatus, said controller being configured to polish said disk substrates in a plurality of stages, including a first stage wherein said polishing apparatus operates at a first pressure and first speed;
• and a second stage wherein said polishing apparatus operates as a second pressure lower than said first pressure and a second speed lower than said first speed, said first and second stages using a common polishing slurry, said second polishing stage being performed after said first polishing stage and without intermediate unloading of said disk substrate.