Thermal Deformation of Micro-structure Diffuser Plate in LED Backlight Unit

In this research, the thermal deformations and thermal warpages of micro-structure diffuser plate in LED backlight unit subjected to long lighting state were studied. The thermal deformations and warpages were obtained by adopting finite element method. In order to obtain more accurate finite element solutions, instead of using the data collected from the existed literatures, the Young’s modulus, Poisson’s ratio, and thermal expansion coefficient of the micro-structure diffuser plate were proposed to be measured by using micro tensile test and thermomechanical analyzer, respectively, in advance. Then the measured mechanical properties were be used as the input data for finite element simulations. By comparing the finite element results with the experimental results measured by using strain gauges, it can be seen that the differences were within in 3 %. In this research, the thermal warpage phenomena of micro-structure diffuser plate corresponding to different temperature were discussed. Also, the difference of the thermal deformation between conventional diffuser plate and micro-structure diffuser plate were compared.