Simulation of hot imprint process of periodic microstructure using elasto-plastic material model

Hot imprint process for thermoplastic polymers is one of the technologies for manufacturing of micro-fluidic and micro-optical components. It combines both microscale resolution and high throughput. In a hot imprint process a rigid stamp is pressed onto a polymer substrate so that micro-patterns can be replicated. Polycarbonate is one of the most important engineering materials in this process. However, nonlinear relationship between temperature and elasto-plastic behavior of this material has not been very well understood until now. This paper explores the development and application of finite element model for studying of polycarbonate substrate behavior under thermal load in order to evaluate temperature and displacement fields as well as stresses formed during hot imprint process. The model of this process includes heat transfer, structural mechanics as well as contact analysis and supports nonlinear structuralthermal analysis with contact, large deformations, and the use of temperature-dependent elastoplastic material formulation. The thermal loads are applied by means of convective boundary conditions. Simulations were performed with COMSOL Multiphysics software using heat transfer transient and structural plane strain parametric analysis types.