Automatic inspection method for macro defects in TFT-LCD color filter fabrication process

Abstract

Defect inspection of thin film transistor liquid crystal displays (TFT-LCDs) is divided into two steps: detection and judgment. This letter proposes an automatic detection and judgment method for macro defects in the TFT-LCD color filter (CF) fabrication process using the diffraction pattern shift and chromaticity, respectively. The proposed method is verified via experiments using sampled CF glasses with macro defects, which were judged as PASS (no defect) in the CF fabrication process by a human operator who inspects CF glasses using conventional inspection systems, but were rejected in the module process. Seventeen rejected glasses were used in the experiments. All macro defects, including non-uniformity under 300 angstrom, were detected and are judged as REJECT (defect) using the proposed method.