Method for contact magnetic transfer of servo pattern to hard magnetic recording disk

摘要

A contact magnetic transfer method for forming a pattern of magnetized servo regions in the magnetic recording layer of a rigid magnetic recording disk uses a flexible master disk and a differential gas pressure to press the patterns of the master disk against the slave disk. The master disk is a flexible plastic film with islands of magnetic shielding material extending above the film surface, the islands forming a pattern representative of the servo pattern to be formed in the recording layer of the disk. The plastic film is sealed at the outer periphery of the opening of a pressure chamber with the islands located outside the chamber. The previously DC-magnetized slave disk is brought into gentle contact with the islands and gas pressure inside the chamber is increased to slightly above atmospheric. This controlled pressure presses the islands into contact with the slave disk, at which time a magnet magnetizes the regions of the recording layer not aligned with the islands in the direction opposite to the original DC-magnetized direction. The magnet is located on a rotatable stage within the chamber beneath the plastic film and mounted so that the length of the gap is in the radial direction corresponding to the radius of the slave disk.