Finite element prediction of the lens shape of moulded optical glass lenses

Abstract

Glass moulding is a high-volume fabrication method suitable for producing optical components embedded in computer, communication, and consumer products, such as optical glass lenses in the camera modules of mobile phones. Despite the advantages of glass moulding, several difficulties encountered in the manufacturing process have yet to be overcome. The most critical issue is deviation between the formed lens and the original lens shape design. To overcome this obstacle, this study constructs a precise material model for optical glass with detailed thermal expansion, structural relaxation, and stress relaxation properties obtained from material experiments. This study also uses finite element analysis (FEA) to predict lens shape by incorporating this precise material model at 30°C above At (which is widely adopted by the industry). A subsequent verification moulding experiment demonstrates consistency between the predicted and experimental results. This study establishes and confirms a comprehensive FEA model for predicting the shape of moulded glass lenses.