Research On Resin Filling Mechanism And Demolding Mechanism Of R2R Imprinting

Bubble defect is a serious problem in the filling process of roll-to-roll ultraviolet imprint lithography process.To investigate the air bubble trapping in micro cavities,a numerical simulation method is proposed based on sliding mesh and open-channel model.Such considerations in the model make it possible to include both the rotation of roller and the flow of resin,which is different from the conventional methods.Through simulation analysis,a parameter,which is termed Filling Angle here,is found to be a significant factor in imprinting process.With this parameter,the relationships between resin accumulation,rotation velocity and bubble defects are studied.And the differences in resin filling at different rotation velocities are also investigated.The experimental observations were in good agreement with the theoretical calculations.The results provide a deep understanding of the filling process,which can be a good theoretical guidance to eliminate the bubble defect.Demolding process of roll-to-roll ultraviolet imprint lithography process is also a widespread concerned process.In demolding process,the copied and transferred microstructures on the substrate are always easily bended,fractured and collapsed.The research of this article is to introduce a film of resin residual layer into roll-to-roll ultraviolet imprint lithography process to improve the quality of demolding process.Through simulation analysis,the study shows that the introduction of the residual layer effectively reduces the stress on microstructure,also raised the adhesive strength between the PET base and microstructure,thus integrity of the microstructure is improved.At the same time,experiment results also shows that,compared with demolding process with no resin residual layer,residual layer is obviously beneficial to improve the integrity of microstructure.