AN EXPERIMENTAL-STUDY OF THE PARAMETERS THAT DETERMINE TAKE-OFF VELOCITY AND CSS PERFORMANCE OF THIN-FILM DISKS

Measurements of take-off velocities under various conditions were carried out in order to explain the fact that a 70 percent microslider gave better performance on CSS than a 100 percent mini slider. It was found that take-off speeds increased as the radii of CSS tracks decreased. On a 65 mm disk, use of a mini slider could result in 40 percent higher take-off velocity when the CSS track was moved from a 2-5 mm radius to 18 mm radius. The main contributor to this increase was found to be clamping effect. Clamping force changed the local curvature of a disk within the 2 mm range, and it over-shadowed surface roughness of a disk. It was also demonstrated that stable sliders, such as a microslider or a slider with a high load, were less vulnerable to clamping effect. CSS tests confirmed that higher clamping force could drastically deteriorate CSS durability.