Can OLED display printing technology be realized?
In addition to the steaming up of each pixel "bulb" of the OLED screen , you can also choose to "print" it out. An example is an inkjet printer that ejects ink onto a paper to present a document or picture. The printed display is a process for making a film of an organic material using a printing method. After the printing display is realized, different panels can be printed. If the "spraying" is an OLED material, it is an OLED display; the "spraying" is a quantum dot material, that is, a quantum dot display panel. Printing OLED, in short, is to deposit a solution of different color polymer luminescent materials in the isolation column groove of the ITO glass substrate through a plurality of printing nozzles on the inkjet printing device, and the solvent will volatilize to form a thickness of about 100 nm. The thin layer constitutes a pixel that can emit light.
Why is print display technology the next generation of display revolution? Vacuum evaporation process, limited by equipment and technology, it is difficult to make large-size fine metal masks, which makes the process unsuitable for the manufacture of large-sized panels. During the evaporation process, the organic material gas is deposited on the glass substrate without any difference, resulting in low material utilization. Perhaps because vacuum evaporation chambers are not needed, precision metal masks are not needed, color filters are not needed, etc. At the CES show in 2013, Panasonic demonstrated a self-developed “printing” process, and They themselves said that it was the world's largest 4K OLED TV (56 inches).
What are the advantages of printed OLEDs to challenge relatively mature evaporation technology? First, the cost is low. In the use of raw materials for OLED panels, printing OLEDs can save 90% compared with evaporation technology; printing OLED technology can effectively improve the life of finished products; The process of ink printing is easier to adapt to the cutting of large substrates than the evaporation process, which is more conducive to the trend of processing large-sized substrates with high-generation lines.
According to industry sources, the biggest bottleneck in printed OLEDs is the differential control between each tiny printed dot (reducing the difference between pixels) and the development of devices for very small sub-pixel units (improving device accuracy). The former is a key bottleneck in the entire print display industry, while the latter is mainly a problem for small and medium size display products. In other words, for printing OLEDs, ink stability is not a final big problem, and equipment accuracy and stability are the real test. This problem must be solved in engineering only after the establishment of a demonstration production line.