MULTI-CHANNEL INTERFEROMETRIC MEASUREMENTS OF SLIDER FLYING HEIGHT AND PITCH

A multichannel interferometer which measures relative displacements from the top of the slider and disk is used to make concurrent measurements of absolute slider flying height and pitch. This technique is applied to actual disks and sliders and is not subject to limitations of low spacing and surface textures which are problematic for white light interferometry and modeling. It is applicable to both constant speed operation and dynamic events including takeoff and landing. It has the bandwidth necessary for dynamic measurements of the interface, depending on the sampling rates used when acquiring data. These features combine to make this an excellent tool for various aspects of head-disk interface development including low flying heights, slider stability, and tribology. The results obtained with this technique are compared with those of white light interferometry and modeling for absolute flying height and pitch measurements