Head stack assembly having a coil portion for damping vibrations which includes elongated openings in the plastic portion

摘要

A disk drive includes an enclosure having a base, a spindle motor fixed to the base, a disk mounted on the spindle motor, a pivot bearing cartridge, and a head stack assembly. The pivot bearing cartridge includes a shaft fixed to the enclosure, and the head stack assembly is connected to the pivot bearing cartridge for rotation relative to the shaft. The head stack assembly includes a body portion having a bore which surrounds the pivot bearing cartridge, a plurality of actuator arms with each arm cantilevered from the body portion, and a coil portion. The coil portion is cantilevered from the body portion in an opposite direction from the plurality of arms and provides damping of vibrations induced in the head stack assembly. The coil portion includes a plastic portion having a thickness, and a coil embedded in the plastic portion. The plastic portion includes a plurality of openings where each opening extends through the entire thickness of the plastic portion. Each opening is also located inside the coil and is substantially elongated in the direction in which the coil portion is cantilevered.