Fabrication of light guide plate using backside exposure lithography

The microstructure of the light guide plate (LGP) is primary microlens array formed by thermal reflow of polymer disks. The back light luminescence is related to the taper angle of the LGP microstructure. From the simulation result, the smaller taper angle in the cone-like structure can lead to the higher light transmission compared to microlens. In this paper; we used the technology of back side exposure lithography to fabricate the controllable taper-angle cone-like array on the PMMA substrate for LGP application. The taper angle of cones is adjusted by the exposure dose and development. From the measurement results, the light uniformity of the cone-like microstructure is between 50-70% and suitable for the requirement of LGP.