- 學位論文
彩色光阻薄膜於真空乾燥製程模擬
Modeling of the vacuum drying process for color resistor thin film
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摘要
薄膜塗佈加工是現在精密工業中常見的技術，而其中膜厚的控制乃是一重要課題；本研究主要探討在彩色濾光片製造過程中，彩色光阻薄膜塗佈後利用真空幫浦抽氣方式，驅使薄膜內的溶劑蒸發散逸，在這段過程中，建立溶劑在氣液介面及真空腔體內部的輸送模型，利用數值模擬的方法，分析其過程中膜厚隨時間的變化。 本論文將分為幾部份，首先第一部分探討真空抽氣幫浦，研究其工作原理，抽氣曲線等特性並將之與真空腔體抽出的氣體量作一連結；第二部份由質量平衡的觀點，建立在真空腔體內及薄膜內部的質量輸送模型，在氣液介面的揮發通量，我們嘗試由氣液兩相雙膜理論及氣相擴散主導兩方式來描述之，此外，並考慮由於薄膜內溶劑蒸發而使液膜溫度下降之效應；第三部份基於前面所建立的輸送模型，將此過程以聯立的微分方程式描述之，利用數值模擬的方式，我們可以得到在此抽氣過程中腔軆壓力，氣液相溶劑濃度，腔體內一維的濃度分布，液膜厚度等等參數隨抽氣時間之變化情形，最後我們將利用數值模擬所得到的結果，與目前彩色濾光片廠實際製造時的總壓力對時間關係圖做一比較，發現以氣相擴散主導方式所得到之模擬結果與實際製程較為接近，而蒸發冷卻效應以數值模擬方式發現對製程影響不大，然而改變抽氣速率對於此製程卻有顯著的影響，由數值模擬的結果，發現降低抽氣速率至一半，將無法在此製程預定的46秒內完成，然而增加抽氣速率至1.5倍，將會使此製程耗時縮短至約一半的20秒內完成，提高單位時間生產量。
並列摘要
The film coating processing is the common technology in modern precision industry，and the controlling of the film thickness is an important issue. This thesis focuses on the simulation of the vacuum drying process in the color resistor coating applied in the color filter manufacturing. The driving force of this process is the vacuum pumping. By decreasing the concentration of solvent in gaseous phase，the solvent evaporation rate will increase. We built the mathematical model of the mass transfer at the interface of the thin film and in the vacuum chamber. By the mathematical simulation， we can analyze the film thickness changing with pumping time. In the first part，we study the working principle of the vacuum pump and the pressure dropping curve. We try to link it to the output term in the mass balance equation. In the second part，we built up the mass transfer model based on the mass balance concept. For the evaporation flux at the interface，we introduce two kind of expressions，one is the two film theory，the other is the model of gaseous diffusion governing mode. We also consider the evaporation cooling effect. In the third part, we simulated this process based on the model above，and the mathematical model is a system of ODES. Compare with the actual process data from the factory，we find the model of gaseous diffusion governing mode is closer to the actual process，and the evaporation cooling effect is not so evident. But from the simulation result，the pumping speed play an important role in this process，if we increase the pumping speed to 1.5 times，we can reduce the process time from 46s to 20s，and that can improve the throughput of the color filter factory.
參考文獻
[27]蘇青森 真空技術 東華書局(1988)
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