Prediction of the thermo-mechanical material behavior of PEN foil during photolithographic processing

Flexible substrates (polymers) for plastic electronic products are far less stable to environmental factors, like heat and moisture, than currently used non-flexible substrates (silicon). This introduces problems during the lithography process of these products. This study presents a thermo-mechanical model of PEN foil; an organic material often used as flexible substrate for plastic electronics. The model is validated with experimental foil behavior during a loading experiment and with the experimental bending behavior in a foil-on-carrier situation. These kind of models are useful as they can be used to predict and to optimize lithographic process steps.