| 摘要: | 由於微機電系統(Micro Electro Mechanical System)的蓬勃發展，各種微流量控制元件倍受重視。目前在微細加工中，以微小孔，微細槽之加工量最多，這類的微細加工，一般常以微放電加工機（MEDM）或光電化學蝕刻（photo etching）來加工，而光電化學蝕刻主要是加工平面的元件，其加工過程中容易造成錐度，形狀精度差，加工速度慢，因此實際應用上有其瓶頸。為解決此瓶頸，本實驗利用一種可精密迴轉之薄的圓盤電極來進行放電加工，由於工具電極與工件在加工過程中並未直接接觸，加工阻力小，藉由控制放電的能量，可有效而且經濟的製造出微細且細長比大的槽。雖然放電加工製作微細元件的速度快、形狀精度佳，是一種很適合快速製造三維立體微細元件的加工方法。但放電所形成的蝕坑(crater)及再凝固層(recast layer)使得放電表面品質惡化以致限制了其應用的範圍，尤其在微細元件更為嚴重。針對此問題，在本實驗中將利用電解拋光(electro polishing)，藉由在兩極間變換電解液並增加電氣能量，使正極表面形成氧化膜，再由電解液沖除產生微小的去除作用，期能獲得精細的加工表面，以符合精密加工的應用需求。 本研究乃是先以微能量放電加工微細槽，再藉電解拋光對微細槽進行精修加工的實驗。藉助於放電加工的加工速度快和電化學加工的表面平整之利，以期望快速得到表面佳且製作快速的微細元件。實驗中先由圓盤電極放電加工製造微細槽，再變換各種不同的電流波型、電流大小、電解液濃度等，以探討電解拋光對微細槽精修加工時之電解擴槽量、槽的形狀精度、表面粗糙度的影響，期望建立微細槽的精密加工技術，以供工業界參考。 Due to the vigorously development of Micro Electro Mechanical System (MEMS) nowadays, it is becoming more and more important to understand the micro-controlling elements. At the moment, it is most common to see micro-hole or micro-slit fabrication. There are several methods of the technique such as photo-etching and microelectrode discharge machinery (MEDM). However, photo etching is not only slow in process, but also create taper during the fabrication, which would cause lower accuracy. MEDM is fast with a satisfying accuracy, which is suitable for producing three-dimensional microelement. Despite that, during the MEDM, crater and recast layer are easily created and lower the excellence of the surface and also restrict its usage area, especially for micro elements. The perspective of this experiment is by using a rotating round electrode disk runs at a steady speed during the EDM process. The electrode of the tool and work piece are not in direct contact, therefore, the resistance of machinery is small. In addition, by controlling the energy of electrode discharge, a micro hole or a large ratio slender slit is presented in a productive and efficient way. This experiment is also using the electro polishing by exchanging the electrolyte between cation and anode to increase its energy. It will form an oxidize membrane on anode that will be flashed out by the electrolyte. Hence, a precise fabricated surface is formed to meet the demand of the industry standard. This research is focusing on electrode discharge machinery using micro energy between the slit, and by using electro polishing to process the precise fabrication. Combining the benefits of EDM and electrochemical polishing, it is promising to present not only fast in processing, but also fine quality surface. In this experiment, started with using the technique of EDM by using round electrode disk to produce micro slit, and according to different current waves, current size, and the concentration of electrolyte to discuss their effects on slit expansion, slit shape precision and the roughness of the surface. In this experiment, the precise fabrication technique of establishes accurate micro slit is discussed for the related industrial reference. |
