Fabrication of Flexible Display Backplane using Fully Roll to Roll Patterning process

Fabrication of Flexible Display Backplane using Fully Roll to Roll Patterning process

"Hwan Keon Lee/ Sang-Jin LEE"
LG Display

The roll-to-roll (R2R) process, which has been attentioned as a future technology in the printing electronics industry decades ago, has recently been actively studied. Currently, for a mono pattern layer such as a touch sensor, R2R process has been applied to the actual mass production. However, due to the distortion of flexible substrate1) used in R2R process, the fabrication of multi-layer pattern has many difficulty problems, especially alignment between stacked layers. The technologies that we have proposed to overcome such issues are imprinting and digital photo-lithography. Imprinting has received a lot of attention becase of benefits as low cost and possible for ultra fine patterns. And digital photo-lithography is the patterning technology that can compensate for substrate deformation, it’s very important for patterning on non-rigid substrates. In this study, imprinting lithography and digital photo-lithography were used for display backplane. We applied alignment system and thin glass imprint mold to improve alignment accuracy of imprinting. And we developed digital photo-lithography for R2R process. As a result, the 20-inch display-backplane on a polyimide film was fabricated through fully R2R process.