軟性顯示器金屬基板研究開發

Development of Stainless Steel Substrate for Flexible Display

莊勝銘(Sheng-Ming Chuang)

指導教授 ： 李碩仁

元智大學/工程學院/機械工程學系/碩士(2011年)

摘要

玻璃基材是目前最普遍之顯示器基材，但是玻璃高剛性之特性使其很難撓性化。目前市場上大部分都是以塑膠作為柔性電子基材，主要取其可撓性與表面平整性，但幾乎都是專利材料，價格貴供貨穩定性不佳。此外，塑膠不耐高溫，鍍膜需使用低溫製程，且本身阻水氣能力差，需增加阻絕層。金屬基材，其耐熱性遠高於塑膠材質，熱膨脹系數（CTE）與玻璃接近，可使用目前之高溫鍍膜製程，成本相對低溫製程低廉，亦無阻水氣的問題。
本研究以電化學微表面處理技術探討不銹鋼金屬表面的雜質層去除及粗糙度改善為應用，開發電化學機械拋光(Electrochemical Mechanical Polishing, ECMP)機台。主要設計為陽極治具與陰極磨頭機構，結合機械作用與電化學反應的加工。ECMP機台可以在 20分鐘之內，將 1 mm不鏽鋼 304表面粗糙度由Ra＝0.05 μm降低到Ra＝0.02 μm，改善不鏽鋼 304表面粗糙度不平均的問題。後續經由表面量測探討不銹鋼 304的表面粗糙度以及抗腐蝕性分析， 證實其可行性與未來機台改善目標。

關鍵字

電化學機械拋光，表面粗糙度，非傳統加工

並列摘要

The glass substrate is the most commonly used material for display products. The characteristics of high rigidity and brittleness make it difficult to be flexible. Although the ultra-thin glass is under development, its cost will not be able to meet the market requirement. Currently, the most popular materials of the substrate of flexible electronics are plastics. Most of these plastics materials are patented products. The prices of them are relatively high and the supply of the materials is sometimes unstable. In addition, the plastics can not suffer high temperature, so the coating processes are limited to lower temperature range. The water-blocking ability of plastics is poorer than metals, so the additional metal barrier layer is necessary to ensure the reliability of the products. For metal substrates, the affordability of high temperature is much better than it of plastics. The coefficient of thermal expansion (CTE) of metals is closer to the CTE of glasses than the CTE of plastics. The high temperature processes are possible for metal substrates. The cost of processes of using metal substrates is cheaper than the cost of using plastics substrates. There is also no water-blacking issue when using metal substrates.

In this study, the technique of electrochemical is applied to remove the impurities on the surface of SS304 specimen and to improve the surface roughness of the specimen. To develop an Electro-Chemical Mechanical Polishing (ECMP) machine is the first task in this study. The design of the ECMP machine needs to consider the fixture of the anode for the specimen of the size of 10 x 10 cm and the moving mechanism of the cathode to improve the process uniformity. By the effects of both mechanical polishing and electrochemical polishing, the ECMP machine can treat the SS304 specimen of the Ra of 0.05 μm before process down to the Ra of 0.02 μm after process within 20 minutes. By measuring the surface roughness of the specimens under different process parameters, the contributions for the process factors can be analysis by using Taguchi Method. The experimental results show the possibility of using ECMP to process the SS304 substrate to get high quality surface and let us understand the corrosion behavior of the SS304 substrate after treatment. Some other improvement objectives and possibilities are also discussed.

並列關鍵字

electrochemical mechanical polishing ； Surface roughness ； unconventional machining

參考文獻

[5] T. K. Chuang and et al., “Flexible Display–AMOLED on Metal Foils,” Proc. SPIE 5801, 234 (2005); doi:10.1117/12.604222.

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