회전구동 정전형 마이크로 액추에이터를 이용한 고트랙밀도 HDD 용 이단 구동 시스템

This paper presents the design, fabrication, and testing results of a dual stage actuator system for a fine positioning of magnetic heads in magnetic disk drives. A novel rotary microactuator which is electrostatically driven and utilized as a secondary actuator was designed. The stator and rotor electrodes in the microactuator was revised to have the optimal shapes and hence produces much higher rotational torque compared with the conventional comb-shape electrodes. The microactuators were successfully fabricated using SoG(silicon on glass) processing technology, which is known as being cost-effective. The fabricated microactuator has the structural thickness of 45㎛ with the gap width of approximately 3㎛. The dynamic characteristic of microactuatorlslider assembly was investigated, and its natural frequency and DC gain were measured to be 304㎑ and 32㎛/V, respectively. The microactuatorlslider assembly was integrated into a HDD model V10 of Samsung Electronics Co. and a dual servo algorithm was tested to explore the tracking performance of dual stage actuator system where the LDV signals instead of magnetic head signals were used. Experimental res ults indicate that this system achieves the tracking accuracy of 30㎛. This value corresponds to a track density of 85,000 track per inch(TPI), which is about 3 times greater than that of current hard disk drives.