An Experimental Study of Head Stack Assembly Dynamics Impact on Head Disc Interaction

As head-disk clearance has been reduced to nearly 1 nm, air bearing slider dynamic stability becomes increasingly important. This paper presents an experimental study about the coupling effects of Head Gimbal Assembly (HGA) dynamics and arm vibration on Head Disk Interaction (HDI). HDI dynamics was evaluated on a disc with defect. It was found that a much bigger vibration of the slider was observed when suspension local bending mode and arm bending mode are closed to each other than the situation that the two modes are separated. It is proved that both HGA and arm are related to HDI dynamics in a hard disc drive. This study is helpful to characterize system dynamics for robust HDI design.