Patterning over the inner curved surface is important because it allows to obtain seamless flexible imprinting stamps However most of the available methods now are suitable for the roller mold with small size In this study a completely modified lithography technique is proposed to fabricate microstructure on a hollow mold with 200 mm in inner diameter and 150 mm in length A spray coating method is adopted A photoresist film with thickness varying from 5 0 to 6 0 ?m is achieved After that excimer laser machining method is employed to fabricate a slender photo-mask which can be implemented for UV patterning on the inner surface of a hollow cylinder On this photo-mask array hexagonal grids with 30 ?m linewidth and totally 145 mm long are prepared Finally a 405 nm UV laser diode scans with constant speed over the photo-mask and hence transfer the pattern on the photomask to the resist film The exposure step is relatively time-saving If the scanning speed is 30 mms-1 it takes more than one hour a little to pattern the whole roller mold (around 940 cm2 area) Although a seamless flexible stamp has still not achieved this study demonstrates the potential and possibility of the proposed technique
An Opto-mechanical System for Ultra-violet Lithography on the Inner Surface of Hollow Cylinder
黃智, 阮. (Author). 2017 8月 21
學生論文: Master's Thesis