ACCELERATED STRESS TESTING OF PIXEL CIRCUITS FOR AMOLED DISPLAYS

摘要

Electronics reliability testing is traditionally carried out by accelerating the failure mechanisms using high temperature and high stress, and then predicting the real-life performance with the Arrhenius model. Such methods have also been applied to OLED testing to predict lifetimes of tens of thousands of hours. However, testing the active matrix OLED thin-film transistor backplane is a unique and complex ca se where standard accelerated testing cannot be directly applied. This is because the failure mechanism of pixel circuits is governed by multiple material and device effects, which are compounded by the self-compensating nature of the circuits. In this wor k, we define and characterize the factors affecting the primary failure mechanism and develop a general method for accelerated stress testing of TFT pixel circuit s in a-Si AMOLED displays. The acceleration factors derived are based on high electric al and temperature stress, and can be used to significantly reduce the testing time required to guarantee a 30000-hour display backplane lifespan. The method can be directly applied to other types of TFT technologies like polysilicon (p-Si) and organ ic TFTs.