Fabrication and Characterization of Stress-Relief Layers for Gas Barrier Coatings

• Main Authors: Yung-Sheng Wang, 王詠聖
• Other Authors: Dong-Sing Wuu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/71620121211714028189

碩士 === 國立中興大學 === 材料科學與工程學系所 === 100 === Recent technical developments have succeeded in promoting the thinness and flexibility of organic light emitting diodes (OLED); however, OLED devices are readily susceptible to the moisture and oxygen. This has led to new challenges in device packaging. Using thin films for packaging is regarded as a feasible method with considerable potential. Multi-layer stack structures comprising inorganic materials stagger the pinholes and micro-defects between layers, thereby minimizing penetration of moisture. Organic materials form long-chain structures that are less effective against moisture; therefore, we employed these materials as a stress-relief layer to prevent the structure of the packaging which destroys by internal stress. This thesis employed a plasma-enhanced chemical vapor deposition (PECVD) system in conjunction with UV light curing equipment to fabricate silicon nitride (SiNx), silicon oxide (SiOx) and a UV light curing polymer. At the beginning, extensive parameters studies of the dependence on respective silicon nitride and silicon oxide growth are considered to be done to develop an optimal condition or recipe for the barrier growth. After obtaining suitable parameters, various pairs of multilayer stacks containing silicon oxide and silicon oxide are prepared to discuss the transmission rates of water vapor and fracture toughness. We also determined how the thickness of the UV light curing polymer layer influences the surface roughness, visible light transmittance, and water vapor transmission rate (WVTR) of the overall packaging structure. Within the optimized barrier structure, the WVTR reached 1.28×10-7 g/m2/day (60 °C and 90 % RH during 1200 hours). The low internal stress stack structure exhibited surface roughness of 0.198 nm and visible light transmittance above 90 %. These results demonstrate the potential and effectiveness of applying stress adjusted packaging structures to OLED devices.