Patent ID: 6790509
Filing Date: 2004-09-14
Classification: G11B,Y10S

Abstract:
A substrate for a magnetic disc, wherein the period of microwaviness is 2 &mgr;m to 4mm, and if we let wa be the maximum height of this microwaviness measured at a measurement area for the microwaviness selected from the recording and playback areas on the substrate and Rmax be the maximum height of surface roughness measured by atomic force microscope at a measurement area for the surface roughness selected from the recording and playback areas on the substrate, when wa is expressed by x and Rmax by y, the following are satisfied:x&lE;5 nm, y&lE;12 nm, y&gE;(10/3)xâˆ’10, y&lE;(10/3)x+2, provided that wa is the difference between the highest and lowest points on a measurement curve of all measured points in a measurement area for the microwaviness.