可視化DLP列印系統開發與探討

Abstract

近年來3D列印的發展漸趨成熟，對於印列微小且精細的結構來說，光固化製程中的雙光子聚合技術已可製造達奈米等級的產品，不過設備成本高、製造時間過長且技術門檻也是一大挑戰；而單光子聚合中的數位光學處理技術(DLP)能夠兼顧高解析度與快速製造的需求。然而，儘管DLP光固化製程技術有其便利性與優勢，但在系統的應用端仍有許多改善的空間，為了製造出理想的產品，在列印前會需要進行大量且重複性高的製程參數測試，欲探討更改某項變因的影響時，往往只能等待產品印製完成且清洗風乾後才可得知結果，不僅需要花費大量的時間，有時卻仍無法找到產生問題的原因。 為改善上述問題，本研究設計並組建一套可視化的DLP上照式列印系統，使用改裝後的DLP投影機作為固化光源，配合將投射畫面縮小的光學路徑，並搭建出可三軸移動的列印平台，同時，在光路中加入可視化的即時監測架構。透過此系統建立一套上照式的對焦方法與流程，成功改善列印的穩定性，亦利用此系統對於光投影畫面的亮度分布與使用不同樹脂原料下列印的解析度做進一步的討論，接著透過MATLAB軟體模擬光源亮度的分布情形與監測系統影像做比較來進行圖檔的灰階修正，使投影畫面與樹脂成化情況更趨近於理論值，再藉由不同三維結構的製作，來探討曝光時間、樹脂配方、間隔等待時間等參數對於列印的影響，可成功印製出深寬比為4的微流道。最後利用可視化系統針對三維結構製作過程中所偵測到的問題與缺陷進行分析與討論，預期可提供3D列印技術開發所需的重要資訊，以及作為積層技術之智慧製造的一大基礎。

In recent years,the technology of 3D Printing has been fully developed. For fabricating tiny and high quality structures, the Two-photon polymerization(TPP) can already produce nano-scale products. However,this techonology requires highly technical threshold. Digital Light Processing(DLP), one of methods in single photon polymerization, can fit the need of high resolution and rapid manufacturing in a low-cost way. Therefore, this study designed and built a set of visualized DLP 3D printing system, used the modified DLP projector as the curing light source, cooperated with the optical path to shrinkage the projected image, and built a three-axis movable mechanism. At the same time, a visualized real-time monitoring structure was added to the optical path. By using this real-time monitoring system, a set of top-down focusing methods and processes were established to improve the printing stability. This study also discussed the brightness distribution of the projection source. Through MATLAB software to simulated the distribution of light source brightness and compared with the real image from the projector to perform grayscale correction of the image file. The influence of exposure time, resin formulation, interval waiting time and other parameters on printing was discussed by the fabrication of different three-dimensional structures, and a micro-channel with an aspect ratio of 4 can be successfully printed. Finally, the visualization system was also used to analyze the problems and defects detected during the production of 3D structures, which is expected to provide important information for the development of 3D printing technology.