Laser Dry Cleaning of ZrO₂ Particles from Air Bearing Surface of Magnetic Head Sliders

Abstract

Laser dry cleaning of ZrO₂ particles from air bearing surface(ABS) of magnetic head sliders has been investigated. The experimental results show that the cleaning threshold of removing ZrO₂ particles from ABS is about 100 mJ/cm². For laser fluence larger than this threshold, cleaning efficiency increases with increasing laser fluence and pulse number, but does not depend on repetition rate up to 30 Hz. The mechanisms of this laser dry cleaning are laser-induced ABS vibration, particle thermal expansion and particle vibration, which produce forces strong enough to detach ZrO₂ particles from ABS. With increasing laser fluence and pulse number, the average acceleration and vibration number of particles induced by laser increase respectively, so that it is easier to remove particles which corresponds to higher cleaning efficiency. For fixed laser fluence and pulse number, changing the repetition rate does not change the average acceleration or the vibration number of particles, therefore laser cleaning efficiency is almost the same for different repetition rates.