Method of detecting defects in TFT-arrays and a TFT-array testing system incorporating the same
AssigneeYieldBoost Tech, Inc.
InventorKyo Young Chung
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Abstract
A system and method for detecting defects in TFT-array panels is provided that improves defect detection accuracy by adjusting the thresholding parameters used to classify defective pixels in accordance with the standard deviation of the measured pixel voltages. The present invention is particularly suited for the testing of TFT-array panels that contain more pixels than can be measured by the sensor of the TFT-array tester in a single measurement. The system and method of the present invention calculates a reference pixel voltage at each pixel based on a low frequency component of the measured pixel voltage, and adjusts the thresholding parameters based on the calculated reference pixel voltage.
Claims26
A method of detecting defects in an electrode array, wherein the electrode array defines a plurality of pixels, comprising:
- applying a test signal to the pixels;
- measuring a voltage at each pixel;
- deriving a low frequency voltage from the measured voltage to yield a reference pixel voltage for each pixel;
- calculating thresholding parameters for each pixel based on the reference pixel voltage;
- and
- determining if a pixel is defective based on its respective calculated thresholding parameters.
A system for detecting defects in an electrode array, wherein the electrode array defines a plurality of pixels, comprising:
- an electrode array tester;
- and
- a controller, wherein the controller:
- controls the electrode array tester so that a test signal is applied to the plurality of pixels,
- determines a voltage at each pixel from pixel voltages measured by the electrode array tester,
- derives a low frequency voltage from the measured voltage to yield a reference pixel voltage for each pixel;
- calculates thresholding parameters for each pixel based on the reference pixel voltage;
- and
- determines if a pixel is defective based on its respective calculated thresholding parameters.
Dependencies are inferred from the claim text.