MAGNETIC DISK AND TREATMENT OF MAGNETIC DISK

摘要

PROBLEM TO BE SOLVED: To obtain a magnetic disk stably having a recording capacity of >=100MB by specifying the thickness and surface roughness of a magnetic recording layer and a method for treatment of this magnetic disk. SOLUTION: The thickness of the magnetic recording layer is confined to <=1μm and the roughness (Ra) of its surface is confined to <=4.1nm in both of the application direction of a magnetic liquid and the direction perpendicular to the application direction. The method of polishing is executed by rotating a magnetic disk 1 in an arrow direction, pressing the rear surface of a polishing tape 2 to a back up roller 3 and guide rolls 4 and 5 and pressing the magnetic recording surface of the magnetic disk 1 to the polishing layer of the polishing tape 2 by the air pressure from a slit air nozzle 6. The magnetic disk 1 is subjected to a burnishing treatment with the polishing tape 2 having the polishing layer having Ra of <=0.20μm in the circumferential arrow direction of the magnetic disk 1 by respective rolls 3 to 5 simultaneously therewith. As a result, the noises of the magnetic disk and the variations in the circumferential direction of the disk are decreased and the high output is obtd.