Reliability and mechanical durability tests of flexible OLED with ALD coating. Issue 7 (22nd October 2015) - Jimbo, Yasuhiro
Abstract: To improve the reliability and mechanical durability of a flexible organic light‐emitting diode display, the entire flexible display is coated with an aluminum oxide film by atomic layer deposition (ALD). Because the step coverage of ALD is excellent, the AlOx film was deposited not only on the front and back surfaces but also on the side surfaces of the display. A high‐temperature and high‐humidity preservation test, repetitive bending tests, and a pencil hardness test were conducted on the flexible display with ALD‐AlOx coating. The display survived 500 h of a 65°C, 95% preservation test, endured a 100, 000‐time repetitive bending test with a curvature radius of 4 mm, and was found to have a pencil hardness of 4H. Abstract : We fabricated flexible organic light‐emitting diode displays with an aluminum oxide coating formed by atomic layer deposition (ALD). The display with the ALD‐AlOx coating survived preservation testing at 65°C, 95% relative humidity for more than 500 h without deterioration. No display defect was observed in the display subjected to 100, 000‐time repetitive bending with a curvature radius of 4 mm. Furthermore, the ALD‐AlOx coating improved the pencil hardness of the display from 3H to 4H.