NUMERICAL CONTACT AND STICTION ANALYSES OF GAUSSIAN ISOTROPIC SURFACES FOR MAGNETIC HEAD SLIDER DISK CONTACT/

Numerical contact and stiction models are used to study the effect of surface roughness and lubricant film thickness on asperity contact and stiction at magnetic head slider/disk interface (HDI). Isotropic Gaus sian surfaces having expected values of the r.m.s. roughness R(q) and the correlation length beta are generated by computer for the contact and stiction analyses. The analysis shows that for a given load, the contact area depends on R(q) and 1/beta. The stiction increases with increasing lubricant thickness and decreasing R(q) but is independent of beta. The stiction between two surfaces can be assessed by their b earing ratio: the surface having a higher bearing ratio for a given fi lm thickness is expected to have a higher stiction. Peak-to-mean dista nce, R(p), is shown to be a more relevant parameter than R(q) to relat e stiction. The relationship between the critical film thickness and t he surface roughness is also studied. For a given surface, the critica l film thickness should be less than 0.25R(p).