Microstructure-based analysis of fine metal mask cleaning in organic light emitting diode display manufacturing

Abstract

This study proposes the unique method to analyze the cleanliness of the fine metal mask (FMM) used in OLED display manufacturing after FMM cleaning process. We developed a FMM-mimic microstructure as a substitute for the FMM, which can be used for the evaluation of cleaning efficiency. The FMM-mimic microstructure was fabricated using a combination of photolithography, reactive ion etching, anodic bonding and sand blasting processes. To demonstrate the proposed cleanliness analytical method, a 1.4 μm-thick Tris-(8-hydroxyquinoline) aluminum (Alq 3 ) film was deposited on the FMM-mimic microstructure as a contaminant by vacuum thermal evaporation. The Alq 3 -deposited FMM-mimic microstructure was cleaned by N-methyl-2-pyrrolidone (NMP) with changing cleaning time. We analyzed the residual contaminants on the FMM-mimic microstructure using a fluorescence microscope. The developed FMMmimic microstructure proves very convenient for inspecting the residual contaminant inside the gap through the transparent glass by general optical and fluorescence microscopy. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

17‐4: Ultra‐high Resolution Full‐Color OLEDs Patterned by Photo‐Lithography

“…In the case of hyper-realistic VR/AR devices that expand user interface (UI) and user experience (UX), the following requirements should be reflected to ensure effective immersion of users; i) minimum 2000 pixels per inch (PPI) to mimic the binocular parallax [3] and ii) high resolution display at UHD level to prevent screen door effects [4]. However, commercialized organic light-emitting diode (OLED) displays have limitations in implementing ultra-high resolution displays as fine metal mask (FMM) methods [5] are commonly utilized to implement pixel patterns. To this end, lots of research have been done through printing methodology including inkjet printing [6], screen printing [7], and organic vapor jet printing [8] to implement high-resolution OLED pixel array.…”