Strategies for improvement of shock performance in hard disk drives

The shock performance of hard disk drives has been a serious issue for laptop computers and AV application HDD. We investigated the nonoperational shock mechanism and studied several parameters that affect the shock performance of the head actuator assembly. It was observed that there are two important factors for the actuator to endure a high-shock level. One is the shock transmissibility and the other is the beating between the arm blade and suspension. To generalize the shock transmissibility, the concept of a shock response spectrum was introduced. The first bending natural frequency of the arm blade was found to be the most important factor in determining the shock transmissibility By applying the shock response spectrum and avoiding the beating, we could design a high-shock performance actuator In addition, a dynamic absorber is introduced to assist in controlling the amplitude and acceleration of the actuator arm.