| 摘要 |
PROBLEM TO BE SOLVED: To improve a metal mold, so that a plastic disk substrate which has high surface precision enough for practical use can be manufactured as a disk substrate adopted for a magnetic recording medium of a fixed magnetic disk drive. SOLUTION: This metal mold for molding a plastic disk substrate has cooling waterways 1c formed dispersively inside, the cooling waterways are so patterned that the distance (h) from the surface of a stamper 1b is 5 to 30 mm and the groove width (d) is 5 to 20 mm, and the pattern of the cooling waterways, is formed as concentric annular grooves. A disk substrate molded by this metal mold has an extremely small surface waving and floating characteristics of a magnetic head as the magnetic recording medium of the fixed magnetic disk drive are improved.
|
