Method and system for machine vision-based feature detection and mark verification in a workpiece or wafer marking system

A system for inspecting machine readable marks on one side of a wafer without requiring transmission of radiant energy from another side of the wafer and through the wafer, the wafer having articles which may include die, chip scale packages, circuit patterns and the like, the marking occurring in a wafer marking system and within a designated region relative to an article position, the articles having a pattern on a first side, the system comprising:

• means for imaging the first side of the wafer to obtain an image;
• means for imaging a mark on the second side of the wafer to obtain an image;
• means for establishing correspondence between a portion of a first side image and a portion of a second side image;
• and
• means for superimposing image data from the first and second sides to determine at least the position of the mark relative to an article.