ESD SPICE model and measurements for a hard disk drive

A simple lumped RLC model for a hard disk drive is developed and used in SPICE circuit simulations. Simulation results were compared with experimental measurements using a special “hybrid” disk drive to validate the SPICE model. The voltage on and between the head and disk inside the drive were modeled during an ESD event to the baseplate and/or disk. Experimental measurements and SPICE modeling show that if the disk grounded when there is a large disk-to-base resistance, then head-to-disk electrical breakdown can occur. It is concluded that an electrical model is valuable in developing an understanding of the effects of ESD on a hard disk drive.