Study on micromoulding of a high viewing angle LED lens

摘要： Lenses are used to mount on the light-emitting diode (LED) chip to obtain the desired light distribution patterns. In this study, a lens for large viewing angle and high uniformity LED has been developed with optical grade poly methyl methacrylate (PMMA) material. TracePro software was used to design the lens while Moldex 3D software was implemented to design the mould and the mould filling phenomena. Together with micromoulding technology and Taguchi experimental method with control parameters were mould temperature (MoT), melt temperature (MT), and injection speed, a lens with optical uniformity of 87.18% and viewing angle of 128° has been developed. The experimental results showed that MoT and MT were the main factors affecting the optical quality, each with contributions greater than 50 and 30%, respectively. Though this lens is relatively small in dimension, a draft angle is needed for successful removal of the moulded PMMA lens from the mould.