Patent ID: 6937753

Claim:
An automated system for inspecting a substrate, including a wafer in any form including whole patterned wafers, sawn wafers, broken wafers, and wafers of any kind on film frames, dies, die in gel paks, die in waffle paks, multi-chip modules often called MCMs, JEDEC trays, Auer boats, and other wafer and die package configurations for defects, the system comprising: a wafer test plate; a wafer provider for providing a wafer to the test plate; a visual inspection device for visual inputting of a plurality of known good quality wafers during training and for visual inspection of other unknown quality wafers during inspection; a low angle illuminator for providing darkfield illumination to the unknown quality wafers during inspection at an angle of less than 6° from the wafer test plate, wherein the low angle illuminator includes four pair of lasers, each pair being positioned at approximately 90 degree spacing around the wafer test plate; and a microprocessor having processing and memory capabilities for developing a model of a good quality wafer and comparing unknown quality wafers to the model.