An ultrathin (∼100μm thick) flexible light plate fabricated using self-alignment and lift-off techniques

An ultrathin (∼100μm thick) flexible light plate was designed and fabricated on a parylene template using a combination of self-alignment and lift-off techniques. The solid-state InGaN light-emitting diodes (LEDs) (λp=465nm) was used as the light source to overcome the problem of conventional organic light-emitting devices which require perfect encapsulation against the permeation of water and oxygen. After the sidewalls of LEDs were passivated by the photodefinable polymer, the LED chip array can be further sandwiched by the indium-tin oxide (ITO) and Al electrodes to form a thin-film package with all the processing temperatures below 250°C. The ITO-coated transparent parylene template can be peeled off from the glass carrier after forming the ultrathin LED light plate. The flexible light plates present no damage even after they were flexed 1000 times around a 3-cm-diameter cylinder. The present self-alignment or mask-less process is a very promising approach to flexible backlight applications.