High resolution phosphor screening method for full-color field emission display applications

Abstract

A polyvinyl alcohol-slurry screening technology of phosphors was studied for field emission displays with a resolution up to supervideo graphics adapter. Phosphor lines were successfully patterned as narrow as 25 μm on 6 in. glass substrates. Process conditions such as spin coating speeds, exposure time, and shadow mask layout for photolithography were related to thickness and line resolutions of phosphor. Luminance characteristics of phosphors were optimized in terms of firing processes. For ZnS:Cu, Al, ZnS:Ag, Cl, and ${\mathrm{Y}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{:Eu}$ phosphors, the firing temperature was optimized to be 400 °C. The nitrogen ambient during the cooling process improves the stability of phosphor surface.