MASTER INFORMATION CARRIER AND METHOD FOR MANUFACTURING MAGNETIC DISK

摘要

A MASTER INFORMATION CARRIER (11) INCLUDES A HIGH-LEVEL REGION (12) AND A LOW- LEVEL REGION (13) THAT ARE FORMED ON A NON-MAGNETIC BASE (20). THE HIGH-LEVEL REGION (12) INCLUDES A FERROMAGNETIC THIN FILM PATTERN (12P) THAT CORRESPONDS TO PREFORMAT INFORMATION SIGNALS. THE MASTER INFORMATION CARRIER (11)IS BROUGHT INTO CLOSE CONTACT WITH A MAGNETIC DISK (51) BY EXHAUSTING A GAS FROM A HOLE OF THE MAGNETIC DISK (51) TO GENERATE NEGATIVE PRESSURE IN A SPACE BETWEEN THE TOW-LEVEL REGION (13) AND THE MAGNETIC DISK (51). IN THIS CASE, TO PREVENT DEFORMATION OF THE CENTRAL PORTION OF THE MASTER INFORMATION CARRIER (11), AN INNER EDGE (12A) OF THE HIGH-LEVEL REGION (12) IN THE RADIAL DIRECTION IS EXTENDED TO THE VICINITY OF A HOLE EDGE (IA) OF THE MAGNETIC DISK (51) SO THAT A PORTION OF THE HIGH-LEVEL REGION (12) COMES INTO CONTACT WITH THE VICINITY OF THE HOLE EDGE (IA). THIS CONFIGURATION CAN IMPROVE THE CLOSE CONTACT BETWEEN THE MASTER INFORMATION CARRIER (11) AND THE MAGNETIC DISK (51), THUS ACHIEVING HIGHER RELIABILITY OF MAGNETIC TRANSFER RECORDING.(FIG 1A)