Support magnetic disk substrate and magnetic disk unit using the support member composed of Forsterite and an iron based component
AssigneeKYOCERA Corporation
InventorsMasahiro Okumura, Shozi Hino, Shinichi Yamaguchi
Life of this patent
Estimating the term…
Abstract
A magnetic disk substrate support member of glass or ceramic for supporting at least one magnetic disk substrate. The support member defines a contact surface which is flat to within 3 .mu.m or less. The support member and the magnetic disk substrate mutually define a contact area in which the support member and the magnetic disk substrate define a ratio of between 50% and 95%. The support member may be a spacer or a shim. The magnetic disk substrate may be arranged on a substantially cylindrical hub and fixed to a rotary shaft via the spacer or shim and supported by a clamp.
Claims8
A magnetic disk substrate support member for supporting at least one magnetic disk substrate, the support member made of a ceramic material comprising a Forsterite component and an iron-based component in the amount of 20% to 60% by weight of the ceramic material, the support member having an electric conductivity of less than 10.sup.7 .OMEGA..cndot. cm in terms of volume specific resistance.
A magnetic disk unit comprising:
- at least one magnetic disk substrate;
- and
- a magnetic disk substrate support member for supporting the magnetic disk substrate, the support member made of a ceramic material comprising a Forsterite component and an iron-based component in the amount of 20% to 60% by weight of the ceramic material, the support member having an electric conductivity of less than 10.sup.7 .OMEGA..cndot. cm in terms of volume specific resistance.
Dependencies are inferred from the claim text.