EHD printing technology to help OLED panel production yield to 100%

Cui Jinxian, a professor at Jeju University in South Korea, and Pems announced the successful development of panel electrode repair technology with a width of 3 μm using electrohydrodynamics (EHD) printing technology, which is expected to raise the OLED panel production yield to 100% . According to the report of South Korea Electronics News (ETNews), Cui Jinxian research team (AMM Lab) and Pems, professors of Jeju University, have announced the successful development of the panel electrode repair technology with the width of 3 micrometers using electrohydrodynamic (EHD) printing technology. Use of this technology can be OLED display yield to 100%. Cui Jinxian said that OLED panels now yield up to about 70%, while the team developed the technology can be used to repair the remaining 30% of the product, equal to the OLED panel production yield can be pulled up to 100%. EHD printing is a kind of ink-jet printing, belonging to the nanometer and the micron level graph printing technology. It is more advantageous than traditional ink jetting to present fine line patterns, and it is possible to use a variety of materials in the polymer series without the limitations of existing quantitative discharge and micro-patterning techniques. The electrode repair phase in the panel process is a technique of reconnecting the broken electrode pattern. Since the defect portion of the electrode pattern can be locally repaired, it is a high added value technology for the production panel. In particular, the panel industry has been quite distressed by the low yield of electrode patterns on large-size and high-performance panels over 40T, which is good news for the development of this new technology. Two large panel areas TFT liquid crystal display (LCD), and OLED production must be repaired process. TFTLCD panel will be in the TFT array process, color filter process and the final stage of the Cell process, the implementation of pattern detection and poor pattern repair. OLED panel is repaired in the Cell stage and the module stage that the parts have been assembled. When the panel size is less than 5T, the module with low yield will be discarded directly, which will be lower than the cost of the repair. But for 5T panel above, the repair is more cost-effective than obsolescence, and the need for repair is higher. The OLED panel must use tiny electrodes with a width less than 5 microns and can not be visually recognized. Therefore, the electrode repair technology developed by Jeju University together with Pems up to 3 microns is expected to be applied to OLED panel manufacturing in the future. Cui Jinxian said that the use of non-contact printing process to repair the electrode width of 3 microns below the technology, in South Korea and the world belong to the initiative. In addition to the constant temperature and pressure in the environment to build printing equipment, the initial investment costs are low, before and after the process will not produce harmful substances, it is also a green process technology. This technology will be subsidized by the 2014 Technical Support Project, which is headed by South Korea's Ministry of Industry, Trade and Industry, and will be commercialized by Pems.