Encapsulation of a Flexible OLED Using a Sealing Line

摘要

Encapsulation of the flexible OLED devices requires a low temperature process and great barrier characteristics against the permeation of water vapor and oxygen. We suggest a new OLED encapsulation method for the flexible OLED device using a sealing line instead of the TFE encapsulation. For the experiments, polyimide substrate with Cu layer was used. First, 0.5 mm width Cu pattern was formed on the polyimide substrate and sealing material was printed on it, followed by the heating. For the sealing line, two different designs are compared. First, a mixture of LMPA and epoxy was investigated to develope the LMPA-epoxy double line structure. In this case, control of the spreadability of the epoxy was a key issue, as the epoxy spread out on the polyimide substrate when the viscosity was low, therefore, various ways were tried to control the spreadability of the polymer. Secondly, LMPA single line was manufactured and the reliability characteristics such as adhesion, bending characteristics and WVTR(water vapor transmission ratio) were investigated and compared with the double line structure.