Aim-an automated inspection microscope for measuring critical dimensions

Abstract

An automated system for measuring critical dimensions of hard disk heads in a production environment has been developed and put to use successfully in manufacturing. It measures features ranging in size from less than a micron to more than half a millimeter. The Automated Inspection Microscope (AIM), makes reliable measurements of these dimensions seven to nine times faster and with about twice the precision than the conventional methods which it replaced. A special purpose region building and merging algorithm produces results which are very dependable when contaminants, scratches or chips are present along with the feature to be measured. The system inspects loads of ninety six heads at a time with little or no operator intervention. This paper discusses the hardware components of the system, its programming, and its role as part of a parts tracking and inspection system. Particular attention will be given to the algorithms and techniques used in measuring the head gaps, which are are in the micron size range. © 1984 SPIE.