Micromachining of polyimide foils for the fabrication of embossing masters for rotary hot embossing processes

In this paper, we report about the microstructuring of polyimide foils for the fabrication of embossing masters for rotary hot embossing processes. The polyimide masters are fabricated by structuring of a commercial polyimide foil with standard microfabricationtechniques such as photolithography and dry etching. Also a simple and cost efficient methodfor the fixation of the patterned polyimide foils to an embossing cylinder is presented. A series of embossing experiments was performed to characterise the structured polyimide foils with regard to their suitability as embossing masters. The parameters for the hot embossing process were investigated as well as the aspect ratios and the surface ratios of the embossing masters. With the fabricated polyimide masters, hot embossing was successfully performed in COC substrates. The developed method represents a cost efficient way for the fabrication of masters for rotary hot embossing combined with the advantage of rather short fabrication time.