TY - GEN
T1 - Fabrication of seamless roller molds using step-and-rotate curved surface photolithography and application on micro-lens array optic film
AU - Li, Wen Hui
AU - Chen, Hong Wei
AU - Hu, Ya Wen
AU - Lee, Yung Chun
AU - Hsiao, Fei Bin
PY - 2011
Y1 - 2011
N2 - This paper describes an innovative approach for fabricating seamless roller molds based on conventional photolithography. The fabricated seamless roller molds are then applied in a UV-curing roller imprinting process to replicate ball-lens-array microstructures on a polymer substrate, which finally forms a light-converging optical film to be used in back-light units of flat panel displays. The roller imprinting process has the advances such as quickly, low cost and large area. First of all, a method for spread coating of a thin photo-resist (PR) layer on a cylindrical surface of a metal roller is developed. This spread coating system relies on pneumatically driven air flow which squeezes through a narrow gap between a roller and an outer ring, and results in a uniformly coated thin PR layer on the cylindrical surface. Secondly, a step-and-rotate UV-exposure system is constructed for transforming patterns defined by a photo-mask to the coated PR layer. Continuous and seamless patterning on the whole cylindrical surface of the roller is achieved through accurate mechanical alignment and precision rotation control of the roller as well as a parallel UV light source. Finally, using the patterned and developed PR structures as a mask, a variety of microstructures with complicated and seamless patterns can be directly fabricated on the metal roller surface by either chemical etching or electroforming process, which complete the fabrication of seamless roller molds. Through UV-curable roller-imprinting, an optical film with ball-lens-array micro-structures have been fabricated and experiment results show a gain value of luminous of 1.2 has been accomplished.
AB - This paper describes an innovative approach for fabricating seamless roller molds based on conventional photolithography. The fabricated seamless roller molds are then applied in a UV-curing roller imprinting process to replicate ball-lens-array microstructures on a polymer substrate, which finally forms a light-converging optical film to be used in back-light units of flat panel displays. The roller imprinting process has the advances such as quickly, low cost and large area. First of all, a method for spread coating of a thin photo-resist (PR) layer on a cylindrical surface of a metal roller is developed. This spread coating system relies on pneumatically driven air flow which squeezes through a narrow gap between a roller and an outer ring, and results in a uniformly coated thin PR layer on the cylindrical surface. Secondly, a step-and-rotate UV-exposure system is constructed for transforming patterns defined by a photo-mask to the coated PR layer. Continuous and seamless patterning on the whole cylindrical surface of the roller is achieved through accurate mechanical alignment and precision rotation control of the roller as well as a parallel UV light source. Finally, using the patterned and developed PR structures as a mask, a variety of microstructures with complicated and seamless patterns can be directly fabricated on the metal roller surface by either chemical etching or electroforming process, which complete the fabrication of seamless roller molds. Through UV-curable roller-imprinting, an optical film with ball-lens-array micro-structures have been fabricated and experiment results show a gain value of luminous of 1.2 has been accomplished.
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U2 - 10.1109/NEMS.2011.6017457
DO - 10.1109/NEMS.2011.6017457
M3 - Conference contribution
AN - SCOPUS:80053300019
SN - 9781612847757
T3 - NEMS 2011 - 6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems
SP - 728
EP - 731
BT - NEMS 2011 - 6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems
T2 - 6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2011
Y2 - 20 February 2011 through 23 February 2011
ER -