Wear Between Lift Tab and Load/Unload Ramp in Hard Disk Drives

A method was developed to characterize wear between the suspension lift tab and the load/unload ramp during load/unload testing in hard disk drives. The change of the friction force between the lift tab and the load/unload ramp was obtained by measuring the change of the voice coil motor (VCM) current. Scanning electron microscopy was used to evaluate the amount of wear debris deposited on the lift tab. The change of the VCM current was correlated with the area of adhering wear debris on the lift tab surface as a function of load/unload cycles and temperature. Energy-dispersive X-ray analysis was performed to identify the chemical composition of the wear debris and determine the wear mechanism.