Algorithms for automatic disk head/slider inspection

Abstract

This paper describes algorithms for automatically inspecting the air-bearing surface (ABS) of disk sliders (heads) for certain types of defects that are global or systematic in the sense that, when they occur, they occur on every slider in a row or, in some cases, on every slider in the entire carrier. These defects are: wrong part, missing rail, geometry error, missing taper, extra taper, misplaced taper, missing poletip and misplaced pole-tip. The inspection system is in production use and has resulted in a significant improvement of the quality of shipped sliders. Here, the associated image-analysis algorithms are described in detail.