Method for making magnetic disks with uneven distribution of bonded/unbonded lubricating molecules
 A magnetic disk having improved tribological characteristics in the data zone of the disk surface while retaining a low sliding stiction in the landing zone is disclosed. It contains the conventional elements of a substrate, a magnetic recording layer, a protective overcoat, and a lubricant layer on the protective overcoat. However, the lubricant layer is UV irradiated under a photo mask to cause a radially inner zone and a radially outer zone. The photo mask is designed so that the radially outer zone of the lubricant layer has a ratio of bonded/unbonded lubricant molecules greater than that in the radially inner zone. The reduced proportion of mobile lubricant molecules in the data zone prevents the lubricant molecules from being collected by the magnetic head. On the other hand, a large proportion of the lubricant molecules in the landing zone remained mobile. This allowed the sliding stiction in the landing zone to stay at the desiredly low value. All these were achieved with a uniform-thickness lubricating layer, thus ensuring thermodynamically stability. 
Trace Storage Tech. Corp.
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Y10S G11B G11B
additional inventional inventional
Jason S. Moon-Sun Philip Yu-Kun
Lin Lin Yong Chen