| 摘要 |
PROBLEM TO BE SOLVED: To realize a washing method of a hard substrate in order to obtain such a magnetic recording medium that a <= several tens ofÅlow flying height of a head at a surface of the hard substrate for the magnetic recording medium is realized. SOLUTION: A low frequency ultrasonic wave washing step is incorporated in a washing method of a hard substrate having a texture formed on a surface of a Ni-P film formed on a hard member plate. For example, a washing method wherein the surface of the substrate is scrubbing washed, ultrasonically washed by a 20-50 kHz low frequency ultrasonic wave in an alkaline detergent solution, successively washed with warm pure water, a pure water and an ultra pure water in this order and finally dryed by using IPA vapor is applied.
|
