Can OLED display printing technology be achieved?
In addition to steaming each pixel "bulb" of the OLED screen, you can also choose to "print" it. Using an inkjet printer, for example, an inkjet printer sprays ink onto paper to present a document or picture. The printed display is the use of printing method to make the organic material film of the display, which is a process method. After realizing the printing display, different panels can be printed, if the "spray" is OLED material, it is OLED display; What is "sprayed" is the quantum dot material, that is, the quantum dot display panel. Printed OLED, simply put, is through a plurality of printing nozzles on inkjet printing equipment, the polymer luminescent material solution of different colors is accurately deposited in the isolation column groove of the ITO glass substrate, and the solvent will form a thin layer with a thickness of about 100 nanometers after volatilization, forming luminous pixels.
Why is print display technology the next generation of display revolution? The vacuum evaporation process, limited by equipment and technology, is difficult to make large-size fine metal masks, resulting in the process cannot be applied to the manufacture of large-size panels. During the evaporation process, organic material gas is deposited on the glass substrate without discrimination, resulting in low material utilization. Perhaps because there is no need for a vacuum evaporation chamber, no need for a precision metal mask template, no need for color filters, etc., Panasonic at CES 2013 showed a self-developed "printing" process, and according to their own words, the world's largest 4K OLED TV (56 inches) at that time.
What are the advantages of printed OLEDs that are enough to challenge the relatively mature evaporation technology? First of all, the cost is low, in the use of raw materials for OLED panels, printing OLED is 90% cheaper than evaporation technology; Printed OLED technology can effectively improve the life of finished products; The inkjet printing process is easier to adapt to the cutting needs of large substrates than the evaporation process, which is more conducive to the trend of high-generation wire processing of large-size substrates.
According to industry insiders, the biggest bottleneck of printing OLED lies in the difference control between each tiny printing point (reducing the difference between pixels), and the research and development of equipment for very small subpixel unit printing (improving equipment accuracy). The former is the key bottleneck of the entire printing display industry, and the latter is mainly a problem for small and medium-sized display products. In other words, for printed OLEDs, ink stability is not the final big problem, equipment accuracy and stability is the real test. This problem can only be solved from the engineering point of view after the establishment of a demonstration production line.