Disk Coating Thickness Control by Means of Plasma Ashing
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2005-Feb-06
In the development of magnetic disk files, one approach to increasing bit density requires a decrease in magnetic media thickness and/or a decrease in the read/write head-medium spacing. The inside diameter thickness of currently available disks is roughly 0.5 - 0.6 Mu. This final thickness is obtained by coating a substrate with dispersion to an initial thickness of approximately 1.0 - 1.5 Mu and buffing the cured coating to the desired thickness. Thus, buffing is needed to remove about half the stock. This is achieved by abrading the coating with a composite material (silica or aluminum oxide) imbedded onto a constantly changing roll of paper that is held in contact with the coated surface.