- 學位論文
浸沾式光阻塗佈與步進式光微影技術應用於微結構滾輪製作之探討
Photoresist Dip-coating and Stepped Lithographic Technique for Directly Fabricating Rigid Microstructures onto Metal Rollers
摘要
滾輪微壓印兼具製程快速且大量連續生產之製程優點，漸漸吸引越來越多的專家或研究團隊紛紛的投入Roll-to-Roll (R to R)相關製程技術。然而微結構滾輪模具製作是相當關鍵的技術，各式製作微結構滾輪之方法，大都製程繁瑣，需要高檔昂貴之設備；一般壓印微結構滾輪是以微結構薄金屬板包覆在滾輪上，緊密附著不易，在滾壓時常有模具位移、翹曲等問題；若以軟性模具進行壓印，則有強度不足、不耐高溫等問題。 本研究致力於滾輪模具製作技術之開發，將結合浸沾式塗佈技術、步進式光微影技術及無電鍍鎳技術，提供一個「簡化製程」、「降低成本」的連續式剛性微結構滾輪製作技術。研究中自行開發之浸沾式光阻塗佈機台，使濕式光阻能塗佈於滾輪上。另外，利用薄膜厚度量測儀搭配自行組裝之量測載台，以「精準」、「快速」的方式進行滾輪上之光阻厚度及均勻性的量測，並透過表面輪廓儀來驗證其可行性。 實驗結果顯示，利用本研究所開發之浸沾式光阻塗佈機台能均勻的將濕式正型光阻(EPG-510)塗佈於表面鍍鎳之實心（直徑為80 mm、長度為120 mm）及空心（外徑為80 mm、內徑為60 mm、長度為120 mm）滾輪上，且光阻均勻度，以容器口徑愈大，其均勻度愈好；而光阻厚度，則以拉昇速度越慢，塗佈之厚度愈薄。此外，燒杯口徑為153 mm，拉昇速度為7.5 mm/min下，能均勻塗佈光阻厚度約為1,400 nm。接著進一步開發步進式曲面曝光機台，能有效的在滾筒型之基材上定義線寬為5 μm、20 μm、40 μm及20×20 μm之矩形陣列之連續式光阻結構，且微結構平行於滾輪的軸線方向，並透過步進角度改變，成功於滾輪上定義出週期不同之連續式微米級的光柵光阻結構。最後運用無電鍍鎳技術，直接在滾輪上製作連續式剛性微結構。
並列摘要
The Roll-to-Roll process has been attracting more attention in recent years as a result of its rapid, continuous production for mass production. However, the fabrication of microstructures on roller surface is the key technique. Most of the microstructured-roller fabrication methods are very complicated and costly, needing high-end facilities. Furthermore, mold slippery and warping problems are frequently encountered due to the weak adhesion between molds and rollers. Soft rollers with microstructures have problems of poor strength durability and temperature endurance. Methods for directly fabricating microstructures onto rollers should be developed. This study proposes an approach for fabrication of rigid microstructure on metal rollers. This process integrates the photoresist dip-coating process, the stepped lithographic process, and electroless nickel plating process to fabricate the continuous microstructures onto the metal rollers. The mechanism of dip-coating, which is composed of a motor, a lifting platform, a container and a roller fixture, is carried out in this study. This study employed on in-house built apparatus for rapid and precise measurement of photoresist-coated thickness, which is composed of a X-Y stage, a rotating stage and a spectrometer. The measured film thickness has been compared those measured with surface profiler. The dip-coating of photoresist onto roller is carried out by pulling the roller out of the glass beaker containing photoresist. The experimental results show that the photoresist (EPG-510) can be uniformly coated onto the nickel-plated roller surface (the diameter is 80 mm, and length is 120 mm) using dip-coating process. It is found that the film uniformity improves if the diameter of the beaker gets large. The thickness can be controlled with the pulling speed; thickness increases with the speed of lifting the roller out from the photoresist bath. The average minimum film thickness of the photoresist is 1,400 nm with 7.5 mm/min of beaker lifting speed in the beaker of 153 mm diameter. Using the stepped rotating lithography technique, the photoresist patterns with 5 μm, 20 μm, 40 μm line widths and 20×20 μm rectangle array have been successfully fabricated onto the nickel-plated roller. In addition, the microstructures with various pitches can be fabricated by adjusting the stepped rotating degree in this work. Subsequently, the roller is treated with electroless nickel plating process. Finally, the residual PR is removed by acetone. After that, a roller with continuous rigid nickel microstructures can be obtained.