Flying-height adjustment of a magnetic head slider with a piezoelectric micro-actuator

The current design of magnetic disk head sliders needs two extra margins in flying height design: one for manufacturing tolerance and one for environmental variations. To reduce these margins, we have developed an adjustable flying height slider. This slider carries a piezoelectric microactuator and its flying height can be controlled. After simulating the piezoelectric deflection and flying characteristics, we designed an air-bearing surface for the slider and fabricated it by silicon microelectromechanical systems processing. Several of the fabrication problems previously reported were solved, and the slider´s change in the flying height as an electric voltage was applied to the microactuator was optically observed. The observed stroke of this flying height adjustment, 6 nm/15 V, was less than the simulated stroke because of contact between the head and the disk, but it is still large enough to reduce the two current flying-height margins.