Design optimization and stamper fabrication of light guiding plates using silicon based micro-features

This study applies a novel fabrication process of molding stamper that combines anisotropic wet etching of silicon-on-insulator (SOI) wafers with electroforming to produce precision stampers. Micron-size features, such as trapezoidal grooves and prisms, can be accurately fabricated and distributed. Because the feature geometry and the distribution can be accurately realized using the proposed scheme, the design optimization of light guide plate (LGP) become realistic. By observing the illumination characteristics of LED edge-lit LGP, the distribution pattern of the LGP is transformed into the parameter design of 7 anchor spacing and the spacing modulation amplitude. This study manipulates the distribution parameters using the fuzzy optimization to obtain a LGP design with high illumination uniformity. The design of a LGP of 3.5 inch using LED light source is used as an illustrated example. The optical software, TracePro is applied to simulate the luminance performance. The optimization converges quickly and provides the optimum design with an average brightness of 2266 (nit) and uniformity of 90% without any use of diffusive sheets. The application demonstrates the feasibility and effectiveness of the proposed scheme.