Methods of manufacturing fluid-dynamic-pressure bearing and spindle motor incorporating the bearing, and spindle motor and recording-disk drive incorporating the bearing

A method in the manufacturing of a fluid-dynamic-pressure bearing which includes a stationary unit and a rotary unit having respective surfaces, the method comprising:

• assembling the stationary unit and the rotary unit such that that the respective surfaces of the stationary and rotary units confront and are spaced from one another and such that the rotary unit is rotatable relative to the stationary unit, wherein an interspace constituting a micro-gap is delimited by and between the respective surfaces;
• subsequently infusing into the micro-gap lubricating fluid in an amount by which a boundary between the lubricating fluid and the ambient atmosphere is formed in the interspace, and
• wherein the shape of the boundary is formed by capillary action between the lubricating fluid and the respective confronting surfaces of the stationary and rotary units such that a surface of the lubricating fluid at the boundary provides a capillary seal that retains the lubricating fluid in the micro-gap, and
• the stationary unit and the rotary unit are left with dry surfaces contiguous, respectively, with those portions of the respective surfaces which delimit the micro-gap;
• treating at least one of the surfaces of the stationary unit and the rotary unit, corresponding to the dry surfaces, with plasma or ultraviolet radiation;
• and
• after the at least one of the surfaces has been treated with the plasma or ultraviolet radiation, applying oil repellant to the surfaces corresponding to the dry surfaces including over the at least one of the surfaces treated with the plasma or the ultraviolet radiation,
• wherein the method further comprises forming a component of one of the units of resin, and wherein the resin component has one of the surfaces constituting the dry surfaces, and the treating of the surface of the resin component, constituting the dry surface, comprises treating the surface with ultraviolet radiation.