Microdrive mechanical design considerations

A newly introduced miniature disk drive (called a "microdrive") provides 340 Mbytes of data storage in a CompactFlash type 2 form factor (36.4 × 42.8 × 5 mm). Although micromechanical components were considered, the drive uses miniaturized conventional designs throughout. The drive contains a single 27.4-mm-diameter disk with a 0.38-mm glass substrate and two picoheads. The 4500-rpm spindle motor is an outer stator design used to maximize coil volume and minimize payload mass and inertia. The stacked-arm rotary actuator has high resonance frequencies because of its small size and mass. A modified load-unload system uses an asymmetric ramp to improve volumetric efficiency and a capacitive power-off retract system. A dual-lever inertia latch is employed with a high-density inertial body to achieve a sufficient inertial response. The electronics card uses direct-chip-attach modules on a 10-cm2 circuit board.