Critical point defect detection for small‐pixel thin‐film transistor array applied to medical display

Abstract

AbstractThin‐film transistor (TFT) array testing technique has been used, which provides defect detection capability to control the yield of the TFT process. In the past, several defect inspection technologies have been developed and applied for the TFT array testing. When the TFT array pixel size is getting smaller and the resolution is higher, they also encounter the performance limitation on detecting the critical defect in this small‐pixel TFT array and facing a limited testing requirement. For medical display applications, the display pixels on an array panel are getting smaller and smaller; therefore, defect detection is getting more important and critical for managing yield with quality. In this study, a novel approach for defect detection was proposed. Here, the proposed voltage imaging technique is used for the TFT array test, and it provides better small‐pixel TFT array defect detection capability. The experimental results show that by using the voltage imaging technique, detecting critical point defect of TFT array can be effectively improved. And the detected small‐pixel size of TFT array panels can be smaller than 55 µm of an advanced medical display.