A study on nano-wear at laser-textured bump tips and the failure mechanism at the head-bump-interface

The disk laser-texture technique has been developed to provide a more controllable head-bump-interface (HBI) for low stiction and low glide. However, this new interface also introduced some new tribology issues, such as the possibility of more catastrophic failures at the HBT. This paper presents a study on nano-scaled sliding wear and fatigue wear on crater-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 /spl mu/m) and densities (spacing 10-100 /spl mu/m). Stress wear tests using altitude chambers and CSS tests were conducted for bump-size 5-15 /spl mu/m and bump-spacing 20-60 /spl mu/m to further examine the HBI wear behavior. The experimental results agreed with the analytical study on the bump design safe regime for minimum wear failure.