Laser Smoothing of the Load/Unload Tabs of Magnetic Recording Head Gimbal Assemblies

Abstract

A novel technology to smooth the metal tab surfaces using a pulsed laser beam is applied to reduce the wear of the load/unload ramps used in disk drives that employ load/unload technology. The laser pulse length, pulse energy and the pulse repetition rate are so chosen that they cause the surface layer of the load/unload tab, approximately 2–3 um deep, to melt and refreeze quickly. As the surface layer melts, the surface tension of the melt removes most of the micro roughness and a smooth surface is obtained. The reduction in the micro surface roughness is confirmed by the AFM traces and a sharp decrease in the light scattered from the tab surface. In wear tests, such tabs show a remarkable improvement in the wear of the plastic load/unload ramps, allowing 5–10 × more load/unload cycles for a given amount of ramp wear.