Trenched Trailing Pad Air Bearing Surface Structure for Improved Thermal Actuation Efficiency

The thermally actuated flying height control (TFC) technology makes accurate flying height control possible. However, one concern is how to have a proper balance between flying height stability and thermal actuation efficiency, as high air-bearing stiffness at the slider's trailing pad increases the flying height stability but reduces thermal actuation efficiency. A trenched trailing pad ABS structure is explored to solve the abovementioned dilemma. The effects of pad shape, trench depth, and width on the thermal actuation efficiency were investigated. Results indicate that the trenched trailing pad structure significantly improves the actuation efficiency as compared to the conventional ABS. The new structure also improves the ease of fabricating relatively small pad sizes by adopting a multiple etching process which allows the photoresist mask outline to be extended beyond the slider's ABS boundary to provide more footprint and stability to the photoresist pattern.