Zone-Based Inspection and Defect Classification for LCD Manufacturing: Trivial Defect Free Procedure for TFT Glass Inspection

Inspection of thin film transistor (TFT)-patterned glass is one of the important processes for TFT-LCD panel manufacturing. Minute pattern defects and particles coexist on the glass and a few defects can cause serious quality problems. If there was a way to classify the defects by its potential fatality, it would be useful to control the product quality and loss of inspection time. This article introduces a rule-based approach of zone-based inspection and defect classification. For the zone-based processing, a defect classifier and its decision boundary were also proposed to differentiate non-fatal defects. An experimental result showed that the defect classifier was useful to select non-fatal defects and over 70% of the trivial defects could be selected with little risk of quality problems. This article also presents an application result to utilize the method in a plant. Since prejudged trivial defects have little influence on panel quality, they could be eliminated without interfering with the factor e...