Abstract
Flexible substrates are light, thin, and not restricted to the environments or spaces, and hence, are commonly applied to mobile devices, such as, RFIDs, electronic books, and ultra-thin displays. In particular, plastic substrates are most commonly used, because they are transparent, reliable, and suitable for Roll-to-Roll processes. However, there still remain several issues by using plastic substrates. This research will propose solutions to address these problems. Study 1：In Roll-to-Roll processes, roller molds are generally manufactured by ultra-precision machining, but this process is not able to produce many special patterns. This research applied both soft-lithography and electro-chemistry to reproduce two-dimensional patterns onto the stainless roller mold, and successfully fabricated a roller mold with diameter of 1.5mm – 38mm, and no restrictions on the patterns. Study 2：Anti-reflection thin-film can be applied to several consumer electronic devices, such as flat panel displays, cameras, and solar cells. Traditionally, it is fabricated by multi-thin film techniques, but the process is unstable and produces low quality thin-film. Many researchers have used nanostructures on silicon or gallium nitride as an alternative, but nanostructures on the plastic thin-film were barely reported. This research applied dry-etching technique to produce nanoscale arrays, and treated by electroforming and hot-pressing PMMA to produce anti-reflection thin-film. By comparing with unstructured PMMA, its anti-reflection rate was reduced from 4.25% to 0.5%, which was better than products of 3M (1.1%). Study 3：The micro-structures on the optical thin-film is becoming more complex than ever, and some structures were already not able to produce by current lithography or ultra-precision machining techniques. Therefore, this research applied the backside exposure technique to produce large-inclined area with three-dimensional micro-structures by controlling the thickness of the substrates. Furthermore, the fabrication processes did not require additional exposure equipment, and no further heat flow treatment was required. Study 4：The micro-structures on the large-area flexible substrates have become increasingly important, but it is difficult to produce structures on large-area flexible substrates by using lithography. Therefore, this research applied electrochemical deposition technique to define patterns on the electrodes, followed by electroless deposition technique to increase thickness and eventually produced micro-structures on flexible substrates. In addition, it was able to produce 50 pieces of electrodes with the same micro-structures in one lithography process. With the same method, it was also able to produce two-dimensional patterns on the roller mold for Roll-to-Roll equipment. In this thesis, it is able to produce any patterns on the roller mold, by using Roll-to-Roll process to produce large-area micro-structures on the flexible substrates. By reducing the cost, economical consumer electronic devices can be developed. Moreover, high-efficiency nanoscale anti-reflection thin-film and large-area 3D micro-structures optical components can be applied to flexible displays industry.