Micro-LED Display Testing for Electrode Shorts and Sub-Element Substitution

The patent applies preliminary action by performing a short-circuit detection test before the main functional pre-test. A test voltage is applied to the cathode electrode to detect electrical shorts between the anode and cathode electrodes of light-emitting elements. This preliminary detection identifies defective elements that should be excluded from subsequent functional testing, improving overall reliability without significantly complicating the testing process.

The patent uses an intermediary test voltage application method to distinguish electrical shorts from other functional defects. By applying a test voltage specifically to the cathode electrode and measuring the resulting current, the system can identify electrical shorts between electrodes. This intermediary detection step provides precise defect classification, enabling accurate determination of which light-emitting elements have electrical shorts versus other types of functional defects, thereby maintaining image quality through appropriate substitution.

The patent segments the testing process into two distinct stages: (1) a rapid short-circuit detection stage using test voltage applied to the cathode electrode, and (2) a functional pre-test stage for elements that pass the short-circuit detection. This segmentation allows the high-precision short-circuit detection to be performed efficiently on all elements first, filtering out defective elements before conducting more time-consuming functional tests, thereby minimizing overall testing time while maintaining high detection accuracy.