A STUDY ON NANO-WEAR AT LASER-TEXTURED BUMP TIPS AND THE FAILURE-MECHANISM AT THE HEAD-BUMP-INTERFACE

Disk laser-texture technique has been developed to provide a more cont rollable head-bump-interface (HBI) for low stiction and low glide, how ever, this new interface also introduced some new tribology issues, su ch as more catastrophic failures might occur at the HBI. This paper pr esents a study on the nano-scaled sliding wear and fatigue wear an cra ter-type laser-bumps. To understand the failure mechanism, the cyclic loading-unloading, impacts, and stress during CSS cycles were analyzed for bumps having different rim-sizes (2-14 mu m) and densities (spaci ng 10-100 mu m). Stress wear tests using altitude chambers and CSS tes ts mere conducted for bump-size 5-15 mu m and bump-spacing 20-60 mu m to further examine the HBI wear behavior. The experimental results agr eed with the analytical study on bump design safe regime for minimum w ear failure.