Study on Development and Application of Gas-Assisted Hot Embossing Process using Anodic Aluminum Oxide Templates
Date Issued
2009
Date
2009
Author(s)
Deng, Wei-Chih
Abstract
This paper reports the development of a gas-assisted hot embossing process using anodic aluminum oxide templates for fabricating nano-holes structures on polycarbonate (PC) film. In the gas-assisted hot embossing process, N¬2 is used as the pressing medium. The distribution of gas pressure is uniform, the process is advantageous to large-area imprint. The Si and glass-based materials can be used as embossing mold. The fabrication of AAO template is easy. In this thesis, the alumina membranes with 80nm and 170nm pitches were fabricated via a two-step anodization, employing 0.1 M oxalic acid as an electrolyte with an anodization voltage of 40 V and 80V. The pore diameter(10nm~100nm) can be controlled by adjusting time and temperature of pore enlargement. By using gas-assisted hot embossing process, the nanostructures can be uniformly fabricated onto the surface of polymer substrates. The filling height of nanostructure can be controlled by controlling the temperature and pressure. The results show that the reflection rate is significantly affected by height of submicron structures. The reflection rate of average 3.16% in the wavelength range from 400 to 600nm is the lowest. In this situation, the height is 350nm, which is fabricated under the processing parameter of 25kg/cm2 gas pressure and 150℃ temperature. The contact angle of PDMS mold, replicated from AAO template, is increased from 114°to 145°The results prove that the gas-assisted hot embossing process with AAO templates is a practicable method to fabricate submicron structures for AR applications in the visible spectral range. In addition, the submicron structures height with the best anti-reflection performance can be obtained by controlling the processing parameter.
Subjects
Anodic Aluminum Oxide
Gas-Assisted Hot Embossing
anti-reflective
Type
thesis
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