Fabrication Of A Seamless Roller Mold By UV-photolithography For Roll Imprinting

In1995, Nanoimprint Technology was firstly proposed as a technology for the manufactureing of micro-and nano-scale patterns by Professor Stephen Y.Cou. It attracts interest from researchers from all over the word because of its high resolution, flexibleility technology and short processing cycle. In1998, roller imprinting was further proposed. Roller imprinting technology inherits the advantage of flat imprint technology and overcomes the shortcomings of discontinuous replication. As a low-cost and high-efficiency imprint techniques, roller imprinting has broad application prospects.The roller mold is the critical part of the roller imprint system. This thesis developed methods to fabricate roller mold by UV photolithography. To design and fabricate the roller mold, several devices were developed, including a dip coating device, an auxiliary device for UV exposure and a device for micro electroforming Ni. The fabrication process of the roller mold is as follows:Firstly, a certain thickness of uniform photoresist film was coated on the roller by the method of dip coating; secondly, micro structures of photoresist were obtained by stepped rotating lithography and development; at last, micro structures of Ni were fabricated on the roller by micro electroforming Ni. The roller molds had been applied to the roller imprinting system, and continuous micro structures are successfully imprinted.A number of experimental and theoretical studies are conducted to improve the manufacturing process, including the dip coating process, the stepped rotating lithography process and the micro electroforming process.1) To obtain a certain thickness of uniform photoresist film, the dip-coating process is numerically simulated and experimented with a particular emphasis on finding the free surface location at different velocities. Good agreement is obtained between computational results and experimental results. Multiple dip coating method is adopted to obtain a uniform and relatively thick film on a rod.2) The analysis results showed that diffraction which is mainly caused by the gap between the mask and photo-resist has most effect on the precision of stepped rotating lithography.Through our research, it is proved that the manufacturing process of roller mold based on UV lithography is feasible, and a further discuss of influence factors on the precision of microstructures was made, which can can provide an experimental foundation on the follow-up optimization.