Effects of process parameters on the replica shape in glass hot embossing

Abstract

Hot embossing is a promising replication technology for precision manufacture of glass micro optical components. However, the optical performance of thermally imprinted micro optical components is significantly deteriorated due to the warpage formed on their global surfaces. The control of surface roughness and replica thickness are also vital in practical applications. This study attempts to experimentally evaluate the effects of different process parameters (i.e., embossing temperature, embossing force, isothermal pressing time, annealing rate, maintenance force and fast cooling point) on the shape parameters (i.e., curvature radius, surface roughness and thickness) of glass replica. The results provide an important means for minimizing the warpage, reducing surface roughness and controlling replica thickness in hot embossing. In this study, a series of glass hot embossing experiments were conducted by a commercially available precision glass molding machine. The surface topography was measured on both the top and the bottom surfaces of embossed glass replicas. The thickness and diameter of the replicas were also measured. The experimental results were then analyzed for quantifying the effects of different process parameters on the shape parameters. The results of this study provide optimal process parameters for practical hot embossing applications.