Dynamic loading criteria for 3-1/2 inch inline HDD using multilayer piezoelectric load/unload mechanism

A 3-1/2 inch magnetic disk drive equipped with a novel load/unload mechanism using a multilayer piezoelectric actuator was developed. Using this drive, the load/unload velocity influence and the slider initial orientation influence, particularly pitch angle, for the contacts between a slider and a disk during the load/unload process were experimentally investigated. The dynamic loading criteria derived from the experimental results were clarified. Applying the derived load/unload condition to several hard disk drives, 20000 load/unload cyclic tests were completed without any head/disk interface failure. These results suggest that the load/unload mechanism, using a multilayer piezoelectric actuator, shows high head/disk interface reliability in very small head/disk spacing