Thermal stability modeling and evaluation of piggy-back microactuator for hard disk drives

In this paper, the thermal stability of a piggyback electrostatic microactuator integrated with head gimbal assembly (HGA) for hard disk drives (HDD) is modeled and evaluated. Firstly, the temperature stability of the microactuator in terms of dimensions is analyzed. Different microstructure materials, such as nickel, Invar, and single crystal silicon, fabricated by LIGA and LISA processes separately, are evaluated based on the finite element model. Then, the thermal deformation and thermal stress of the microactuator are simulated for two schemes of die-attach HGA integration. Lastly, the variance in operational characteristics of the microactuator caused by the thermal deformation is analyzed by electrical-mechanical couple analysis. The evaluation results demonstrate that the single crystal silicon microactuator with the four spot die-attach HGA integration has better thermal stability in operational performance.