環形PDMS軟模結合氣囊滾輪複製UV樹脂連續陽極氧化鋁奈米結構製程研發

Combination of Circular PDMS Mold and Gasbag Roller to Replicate Continuous Anodic Aluminum Oxide Nano Structures by UV Resin on PC Film

李昀珩(Yun-Heng Lee)

指導教授 ： 楊申語

國立臺灣大學/工學院/機械工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.02661

摘要

表面奈米結構之薄膜廣泛應用於抗反射、生物醫學檢測以及自潔等，其製造以滾壓複製最快捷。滾輪壓印具有快速、連續、大面積的優點，目前奈米結構滾輪模具的製作，大多以電子束、離子束加工方式，加工面積小且設備昂貴；或是以電鑄模具包覆於滾輪上，滾壓時易產生模具翹曲與位移；而剛性滾輪於滾壓時模具與基材僅有切線接觸，使得滾壓速度受限。本論文提出環形陽極氧化鋁奈米結構滾輪模具，經過澆鑄製作出連續奈米結構之無縫環形PDMS軟模，結合氣囊滾輪，當充入適當滾輪內部氣囊壓力，並以適當壓力施加於滾輪軸上，氣囊滾輪可使滾壓模具與基材間接觸面積大幅增加，壓力均勻度提升，可更有效在PC膜上製作奈米結構。
本研究使用純度99.9%環形鋁管材製作陽極氧化鋁(Anodic Aluminum Oxide，AAO)模具，鋁管之外徑、內徑分別為66mm及60mm，高度為50mm，於管材內管壁直接製作陽極氧化鋁奈米孔洞結構，並確認其結構於圓周各角度上之生成狀況皆相同。以80V、180V的外加電壓，搭配適當之酸液，獲得具奈米孔洞結構的環形氧化鋁模具，其奈米孔洞間距分別為220nm及430nm，奈米孔洞大小分別為160nm及230nm。利用微鑄造成型法將AAO奈米結構複製於無縫環形PDMS軟模外圍，將其套於氣囊滾輪上進行UV樹脂滾壓。
利用感壓軟片實驗證實，氣囊滾輪有效的增加滾輪與基材間之接觸長度以及壓力均勻度，可延長曝光範圍；探討具不同奈米尺寸模具以及兩種不同黏度之紫外光固化樹脂下進行滾壓，在適當氣囊內部壓力以及外部施加壓力配合下可成功將陽極氧化鋁奈米結構完整且大面積的複製於PC基材上。
為驗證其光學抗反射、疏水性能，將具奈米結構之PC膜進行反射率、接觸角之量測，經光譜儀量測結果其反射率由原先的14.77%降低至2%；經表面接觸角量測儀分析後，接觸角度從原始的77.5°增加至124.1°。

關鍵字

氣囊滾輪 ； 陽極氧化鋁 ； 奈米壓印 ； 紫外光固化樹脂

並列摘要

Nanostructured thin films have been widely applied for anti-reflective components, bio-sensing and self-cleaning surfaces. The roller molds for production of nanostructured films mostly are made by expensive processes, such as e-beam or focused ion beam, or by wrapping the electroplated mold on the roller. Cost and complication are problems. Furthermore, the contact between the rigid roller and the substrate is nearly a line; the brief contact prevent perfect replication at high rolling speed. This study develops an effective, fast, and low-cost method to fabricate seamless anodic aluminum oxide (AAO) roller mold. Circular PDMS (polydimethylsiloxane) mold with nanostructures is then cast from the AAO roller mold and used as the mold. A facility combining UV-based imprinting technique, gasbag-roller and circular PDMS mold, has been designed and implemented to replicate nanostructures on the surface of polycarbonate (PC) continuously. The gasbag-roller is employed to increase the contact area and to ensure the conformity of contact between the mold and the substrate.
The AAO roller mold is made by 2-step anodization process from a 99.9% purity circular aluminum tube, and the nano-pores are fabricated in the internal wall of the tube. The outer and inner diameters are 66mm and 60mm respectively, and the length is 50mm. The SEM photos show that the fabricated nanopores are similar as observed from all degrees of the surface.The alumina oxide membranes with nanopores of 220 nm and 430 nm in pitch and 160nm and 230nm in nanopore size are fabricated with anodization voltages of 80 V and 180 V, respectively. Nano pillars have been fabricated on the surface of circular PDMS mold by micro-casting. The circular PDMS mold with nanostructures is sustained by a gasbag roller.
With aid of pressure sensitive films, it is verified that the combination of the gasbag-roller and the PDMS mold not only increases the contact area between roller and substrate, but also enhances the pressure uniformity over the contact area. The quality and speed of replication thus can be greatly improved. The effects of mold and viscosity of UV curable resin in the roller imprinting process have been investigated. The nanostructures can be successfully fabricated on the PC film with appropriate inner gas pressure in the gasbag and external pressure applied on the shaft.
The antireflection and the hydrophobic effect of the fabricated PC film have been measured. The reflection has been dropped from 14.77% in the bare PC film to 2% in the PC film with AAO nanostructures. The contact angle has increase from 77.5° in the bare PC film to 124.1° in the PC film with AAO nanostructures. The results prove that an effective replication facility and process has been developed for fast and effective replication of nanostructures.

並列關鍵字

gasbag roller ； Anodic Aluminum Oxide ； nano imprinting ； UV resin

參考文獻

[9] 吳景棠，氣囊輪紫外光樹脂滾壓製程技術之研發及應用，國立台灣大學博士論文，民國99年7月。

[11] 江亮霆，乾膜光阻應用於微結構滾輪製作之探討，國立台灣大學機械工程學研究所碩士論文，96年6月。

[33] 黃培穎，氣體輔助軟模壓印技術之研發應用於製作SU-8脊梁式光波導元件，國立台灣大學碩士論文，民國95年6月。

[1] M. T. Gale, “Replication techniques for diffractive optical elements”, Microelectronic Engineering, 34 pp. 321-339, 1997.

[2] H. Lee, S. Hong, K. Yang and K. Choi, “Fabrication of 100nm metal lines on flexible plastic substrate using ultraviolet curing nanoimprint lithography,” Applied Physics Letters, Vol. 88, 143112, 2006.