摘要 |
A rigid magnetic memory disc (28) is disclosed having a substantially flat, central hard core substrate (12) and an overlying smoothing layer (14) deposited thereon. The smoothing layer (14) is subsequently polished to a predetermined thickness. The smoothing layer (14) should be capable of having a surface finish better than approximately ten Angstroms Ra. After the smoothing layer (14) is polished, an appropriate magnetic medium (16) and alternately, a nonmagnetic finishing layer (16) are then applied to the rigid disc substrate (10) as necessary, ultimately rendering a finished magnetic disc. The flatness of the underlying central hard core substrate (12) and the flatness and smoothness of the smoothing layer (14), the overlying magnetic medium (16) and the overlying finishing layer (18) allows the read-write head (24) to pass over the magnetic medium (16), or the finishing layer (18), if present, at both a substantially constant and substantially low flying height, thus increasing the areal density of the rigid magnetic memory disc (28). Preferably, the typical flying height of the read-write head (24) is approximately less than two and one-half microinches.
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