P‐70: Improvement of Material Utilization of Organic Evaporation Source for Manufacturing Large‐Sized AMOLED Devices

Abstract

We have developed a valved organic evaporation source for 4th generation substrate (730*920mm2) which enables shutoff during idling time and open process time only. So we could improve the efficiency of material utilization dramatically compared with conventional sources such as point sources or linear sources. Generally, linear source is longer than width of substrate and it makes material consumed so much. However, a valved source we developed is designed shorter than width of substrate to save material by preventing unnecessary flux out warding the substrate. In addition, it is comprised of 5 individual nozzles which have many holes in order to achieve the desired uniformity. As a result, we could obtain 30% of material utilization and 5% of non‐uniformity for a 730mm wide substrate. We expect this source can improve performance and reduce the COO (Cost of Operation).

P‐199L: Late‐News Poster: Development of Large‐Sized AMOLED Manufacturing System

“…The blue plot shows the flux rate at the beginning and the brown plot overlays the flux after 13.5 hours of continuous operation. The plot shows that the flux remained nearly unchanged after this long period indicating minimal process changes over time [1].…”

“…In this paper, we tested the material utilization with Alq 3 by measuring the variation of weights between bare wafer and deposited wafer. Through the actual evaporation tests, we were able to achieve 35.61% of material utilization within 4 th generation substrate [1] and 52.23% within 5 th generation substrate.…”

“…The mobility phase of material was THF+water (7:3) and UV wavelength used in this measurement was 340nm and 254nm [2].…”

OLED Fabrication by Using a Novel Planar Evaporation Technique

“…To measure the material utilization rate of the planar source plate directly, (5,6,11,12)tetraphenylnaphthacene (rubrene) was deposited onto the glass substrate at varying distances between the target substrate and planar source plate (T/S). We used approximately 16 mg of rubrene for each studied material in the planar source.…”

“…Most in use are evaporation systems equipped with a point source. Although the point source provides good film nonuniformity, in case the source-to-substrate distance is sufficiently long, the material utilization rate is known to be much less than 10% [4,5]. The high waste of those expensive organic materials is one major cause of the current high cost in OLEDs manufacturing.…”