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.