氣囊輪輔助墨水轉印滾壓製程之研發及應用

Abstract

使用滾輪製作微結構是目前最能夠高速且連續製作的方法，但是使用滾輪熱壓成型製作微結構，加熱冷卻的過程會使材料收縮產生翹曲；而使用滾輪紫外光固化成型製作微結構，在基材上會有殘留層。為了解決翹曲與殘留層的問題，本研究開發氣囊輪輔助墨水轉印滾壓製程來製作微結構。 本研究應用氣體均勻加壓的優點，設計氣囊加壓滾輪，藉氣體使壓力均勻分佈於轉印基材上，模具採用PDMS軟模製作，加上以高含水性的發泡PVA供墨滾輪，使用捲對捲連續送料系統，可於180 μm厚的PC塑膠基材表面製作出寬幅250 mm均勻的微米陣列孔洞結構，孔洞直徑130 μm，間距200 μm。實驗結果發現氣囊滾輪比傳統的金屬滾輪及橡膠滾輪有更大的操作窗，更易成型微結構，並且沒有殘留層。本研究也改變孔洞大小及間距的模具進行測試，發現模具與基材真實接觸面的轉印壓力，是影響微結構成型的主因之一。 接著應用本研究開發的設備進行彩色濾光片的製作，目前彩色濾光片多使用曝光顯影製程，手續繁雜且昂貴，本研究設備無殘留層且連續轉印的特性，適合用在彩色濾光片黑色矩陣及彩色色塊的印製上。本研究利用多道手續的轉印，將黑色、紅色、綠色及藍色光阻轉印製PC薄膜上，透過機台上架設的數位顯微鏡，可以準確地對位各色塊轉印位置。本論文製作出230 x 400 mm2大小的彩色濾光片，每個色塊大小為130 x 300 μm2，經由量測色塊的亮度差異小於7 %，印證氣囊輪輔助墨水轉印滾壓製程具有應用於產業的潛力。

Roller imprinting has attracted grate attention due to its rapid, continuous nature; it is especially good for mass production. But there are still some problems need to be improved, such as warpage im roller hot embossing or residual layer. In roller UV inprinting This study is devoted to developing gasbag-roller-assisted ink roller imprinting process and its application. The technique combines ink roller imprinting technique, gasbag-roller press and PDMS (Polydimethylsiloxane) flexible mold to replicate patterns on the polymeric film. Due to the isotropic pressure provided by the gasbag roller, the contact area between the mold and the substrate is increased and the uniformity of the imprinting pressure is enhanced. The photoresist is coated onto the PDMS mold roller surface by PVA (Polyvinyl acetate) foam roller. The polymer film is fed in-between gasbag-roller and PDMS mold roller, and the photoresist is then transferred from PDMS mold to PC (polycarbonate) film. Finally, the photoresist is cured by UV light. The micro-hole array is successfully fabricated on the PC film. The gasbag-roller-assisted ink roller imprinting technique is further employed to manufacture color filter, which consists of black matrix and RGB (red, green, blue) color block structures. The black matrix is imprinted on PC film first. The red, blue, and green blocks with dimension of 130 × 300 μm2 are precisely imprinted on the PC film after the roller/film alignments are verified with a high-resolution camera. The color filters with dimension of 250 × 400 mm2 have been fabricated. The variation in brightness between colors is less than 7%. This proves the potential of applying gasbag-roller-assisted ink roller imprinting technique on industry.