A method of inspecting a thin film transistor liquid crystal substrate and correcting defects thereon, the thin film transistor liquid crystal substrate including
- scan lines,
- signal lines intersecting with the scan lines without being connected thereto, intersections of the scan lines and the signal lines corresponding to pixels of the thin film transistor liquid crystal substrate,
- a transparent pixel electrode provided at each of the intersections of the scan lines and the signal lines, and
- a plurality of thin film transistors connected to each transparent pixel electrode and the scan line and the signal line associated therewith,
- wherein one of (1) each of the scan lines and (2) each of the signal lines is divided into a plurality of separate lines at each of the intersections of the scan lines and the signal lines;
- the method comprising the steps of:
- applying a voltage pulse between a scan connection terminal wiring connecting a plurality of the scan lines together in common and a signal connection terminal wiring connecting a plurality of the signal lines together in common;
- obtaining a first differential infrared image of the plurality of scan lines and the plurality of signal lines from a first infrared image of the plurality of scan lines and the plurality of signal lines obtained with an infrared image detection system during application of the voltage pulse and a second infrared image of the plurality of scan lines and the plurality of signal lines obtained with the infrared image detection system after application of the voltage pulse, the first differential infrared image being obtained by calculating one of (1) a difference between the first infrared image and the second infrared image and (2) a quotient of the first infrared image and the second infrared image, the first differential infrared image showing a difference between a heating state of the plurality of scan lines and the plurality of signal lines during application of the voltage pulse and a heating state of the plurality of scan lines and the plurality of signal lines after application of the voltage pulse caused by a current pulse flowing between one of the plurality of scan lines and one of the plurality of signal lines through a short circuit defect existing between the one scan line and the one signal line at the intersection of the one scan line and the one signal line;
- specifying the intersection at which the short circuit defect exists based on the first differential infrared image and position data detected by position detecting means representing a position of the thin film transistor liquid crystal substrate;
- obtaining a second differential infrared image of a vicinity of the intersection at which the short circuit defect exists from a third infrared image of the vicinity obtained with the infrared image detection system during application of the voltage pulse and a fourth infrared image of the vicinity of the intersection at which the short circuit exists obtained with the infrared image detection system after application of the voltage pulse, the second differential infrared image being obtained by calculating one of (1) a difference between the third infrared image and the fourth infrared image and (2) a quotient of the third infrared image and the fourth infrared image, the second differential infrared image showing a difference between a heating state of the vicinity of the intersection at which the short circuit exists during application of the voltage pulse and a heating state of the vicinity of the intersection at which the short circuit exists after application of the voltage pulse caused by the current pulse flowing between the one scan line and the one signal line through the short circuit defect;
- calculating a displacement of a position at which the short circuit defects exists relative to a predetermined position in the vicinity of the intersection at which the short circuit exists by extracting coordinates of the position at which the short circuit defect exists in an infrared image coordinate system from the second differential infrared image and calculating a difference between the extracted coordinates of the position at which the short circuit defect exists in the infrared image coordinate system and coordinates of the predetermined position in the infrared image coordinate system based on pattern matching between the fourth infrared image and a reference infrared image including the predetermined position;
- determining at least one cutting position at which it is necessary to cut at least one of the separate lines and the thin film transistors at the intersection at which the short circuit exists to eliminate the short circuit defect based on the displacement of the position at which the short circuit defect exists relative to the predetermined position and a visible image of the vicinity of the intersection at which the short circuit exists including the predetermined position obtained with a visible image detection system having an optical axis coinciding with an optical axis of an energy beam irradiation system;
- and
- eliminating the short circuit defect by cutting the at least one of the separate lines and the thin film transistors at the at least one cutting position by irradiating an energy beam on the at least one cutting position from the energy beam irradiation system.