Validation of the Finite Element Model and Vibration Characteristic of the Piezoelectric Head Gimbal Assembly

The dual-stage head gimbal assembly of the hard disk drive utilizes the piezoelectric actuator to supplement the voice coil motor for the precision head positioning. Vibration characteristic of the head gimbal assembly system is analyzed by using the finite element method. The modal characteristic of the piezoelectric head gimbal assembly is measured by the laser doppler vibrometer and compared with the finite element result to validate the finite element model. The natural frequencies and vibration mode shapes are determined via the frequency response functions by measuring the system response at the side of the head slider and the top of the load beam. The crucial vibration modes that may cause the off-track positioning of the read/write head are reported. The comparison of natural frequencies and mode shapes show agreement of the finite element model and experiment testing.