PDMS環模結合氣囊滾輪複製UV樹脂微奈米結構製程的研發及應用

Combination of Circular PDMS Mold and Gasbag Roller to Replicate Micro/Nano Structures of UV Resin on PC Film

莊岱融(Tai-Jung Chuang)

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(2011年)

https://doi.org/10.6342/NTU.2011.02408

摘要

滾輪壓印可連續複製微結構，是微結構元件主要的製造方法。但由於傳統的微結構滾輪製作方式是以電鑄鎳模包覆於滾輪上，滾壓時易產生模具翹曲與位移，加上剛性滾輪於滾壓時模具與基材僅有切線接觸，導致滾壓速度無法太快。因此本論文提出環形PDMS軟模結合氣囊滾輪來複製UV樹脂微結構於PC膜上，透過氣囊滾輪撐開外圍具有微結構的環形PDMS軟模，並施加壓力於滾輪軸上時，滾輪模具與基材間的接觸長度從原始的線接觸轉變為面接觸，能有效的提升滾壓時壓力的均勻度和微結構成型速度。
本研究首先將氣囊滾輪組件、施壓組件、移動平台組件和UV鹵素燈這四個單元結合，組立成一部氣囊滾輪紫外光樹脂滾壓機台。氣囊滾輪的製作方式是切削鋁合金啞鈴狀滾輪，外層包覆一撓性佳並具有高延展性的矽膠材料形成一個密閉腔體；環形PDMS軟模的製作方式主要利用大面積熱壓成型結合PDMS微鑄造技術將V溝微結構製作在環形PDMS軟模的外圍。
經感壓軟片實驗證實氣囊滾輪有效地增加滾輪與基材間之接觸長度與壓力均勻度，可增長曝光時間，與剛性滾輪滾壓結果比較，可大幅提升微結構成型速度。在適當之滾壓參數配合下即可成功地將V溝微結構完整且大面積的複製於PC基材上，結構轉寫高度與模具微結構相比，結構複製率可達87%。
本研究進一步將陽極氧化鋁 (AAO)奈米結構以微鑄造技術製作在環形PDMS軟模上，經自組裝的紫外光樹脂滾壓機台，成功地在PC塑膠基材製作奈米柱，有奈米柱之PC膜經表面接觸角量測儀分析後，接觸角度從原始的86.4°增加到108.1°，有效的增加表面疏水效果，其光學性能光譜儀反射率分析後發現在500nm的波長下反射率從原始的9%降至6%。本研究也將菲涅爾結構複製到PC膜上經由光強度計量測，聚焦後的光強度增加了三倍。

關鍵字

PDMS環模 ； 氣囊滾輪 ； UV壓印

並列摘要

Replicating microstructure by roller imprinting is one of the most effective methods to produce the components with nano micro-structures on surface. However, there are two challenges: how to better prepare the roller mold and how to increase the contact area between roller and substrate. The contact between the rigid roller and the substrate is nearly a line; the brief contact prevent perfect replication at high rolling speed. On the other hand, the conventional method producing the microstructure on the roller mold is done by wrapping the electroplated Ni mold on the roller. Warp and deformation of mold easily occur during rolling imprinting.
In this research, a circular PDMS (polydimethylsiloxane) mold and a gasbag-roller imprinting facility are developed. The gasbag with controlled inner gas pressure is employed to sustain the circular PDMS flexible mold with microstructure. When a external pressure is applied on the shaft of gasbag-roller, the contact area between the roller and the substrate has been increased significantly from original line contact to area contact. This allows ample contact area and time between a gasbag-roller and substrate for the micro-structures on the mold to be completely replicated and cured.
With aid of pressure sensitive films, it is discovered 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 contact pressure over the contact area. The quality and speed of replication thus can be greatly improved. A V-cut microstructure has been fabricated on the circular PDMS mold by micro-casting, and used for the gasbag-roller sustained circular PDMS mold. Experimental result show that over a large operational window of inner gas and external pressures the replication can be perfect.
The imprinting facility and process have been employed to replicate AAO nanostructures on the PC film for antireflection and hydrophobic effect. The reflection has been droped from 9% in the bare PC film to 6% in the PC film with AAO nanostructures. The contact angle has increase from 86.4 o in the bare PC film to 108.1o in the PC film with AAO nanostructures. Fresnel microstructures are also replicated for the function of light-focusing. The light intensity has increased threefold as measured by the optical power meter. The results prove that an effective replication facility and process has been developed for fast and effective replication of micro- and nano-structures.

並列關鍵字

Circular PDMS mold ； Gasbag-roller ； UV imprinting

參考文獻

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