Effect of lubricant thickness and viscosity and rest time on long-term stiction in magnetic thin-film rigid disks

This study makes a first attempt to address long term stiction as a function of lubricant film thickness and its viscosity, and if stiction ever approaches a constant value. Three types of lubricants are chosen in the tests. The equilibrium rest time, defined as the time for static friction force to reach its steady-state value, is reached after the head slider rests on the disk surface for a long enough time. A thicker lubricant film increases the static friction force but shortens the defined equilibrium rest time. Higher viscosity increases the static friction force and equilibrium rest time. Comparison between unlubricated and lubricated disks shows that stiction due to solid-solid asperity contact is negligible. The effect of lubricant viscous flow on the meniscus force at intermediate humidities is discussed.