| 摘要 |
PURPOSE:To finish the base plate of a magnetic disc to mirror finished surface, an extremely low roughness, by using special grinding solution. CONSTITUTION:The base plate 20 of a magnetic disc is seized under pressure between the magnetic cloths 27 and 28, and its both sides are ground at the same time to finish by rotating the grinding cloths 27 and 28 driven by the belts 33 and 34 with the colloidal silica solution 31 and 32 supplied as grinding solution through the grinding liquid supply pipes 29 and 30, which solution is a colloidal solution of ultra fine particles of silicin anhydride. In this grinding solution the silicic anhydride particles have an extremely small diameter in the range from about 0.01mum to about 0.02mum and are of round shape, giving no minute grinding scars under low pressure. It is possible to grind both sides of the base plate 20 to mirror finished surface with surface roughness, for example, below 0.005mum Rmax. |
