Rolling bearings used for transporting wafers and liquid crystals in the film-forming process of semiconductor and LC panel manufacturing are required to minimize the particles (originating from both lubricant and bearing material) they generate while in operation. The research reported in this paper focuses on the particle generation under different rotational conditions of ball bearings and ball screws coated with various solid lubricants and operating in a vacuum environment. The results of the tests indicated that a specially composed and applied polytetrafluoroethylene (PTFE) coating was superior in minimizing particle generation by ball bearings and ball screws. Observation of the bearing interior surfaces indicated that particle generation is primarily caused by wear of cage-pocket surfaces, while sudden and large increases in wear are the result of the balls making direct surface-to-surface contact with the raceways and cages due to erosion of the solid lubricant coatings.Presented at the 53rd Annual Meeting in Detroit, Michigan May 17–21, 1998