| 摘要: | 遮罩式微電化學加工之優點在於欲加工不同之成品只需透過改變遮罩外型即可完成不同幾何形狀之加工，然而，目前遮罩式微電化學加工的發展都僅止於靜態加工，刀具的大小需與欲加工物一致，本文主要藉由縮小刀具，再給定一穩定之移動速度，一方面可以降低刀具生產之成本，另一方面觀察成品是否可以更均勻完整，利用有限元素法創建熱流場與電場之二維模型，討論不同電解液流速、施加電壓、遮罩厚度對加工外形之影響
模擬結果顯示，電壓越大時，加工深度越深，島狀比率隨電壓增加而減小；電解液流速愈低，加工區電解液溫度愈高，島狀比率也隨之上升；遮罩厚度愈厚，遮罩之遮蔽能力愈好，局部電流密度愈小，加工深度愈淺，島狀比率愈小；移動速度越慢，加工時間更長，可使加工深度越深，越均勻，島狀比率越小。比較在相同加工深度下，固定式刀具比動態刀具有較少的加工時間，但動態刀具可使加工孔有較小的島狀比率。
;Through-mask electrochemical micro machining (TMEMM) is different from the normal Electrochemical micro machining (EMM). The design expense of the electrode tool can be saved because the electrode tool won’t be affected by the shape of the ending product. Without changing the electrode tool, TMEMM can fulfill end product with any shape by only changing the shape of the electric insulated mask. The development of through-mask electrochemical micro-machining is restricted in the static processing. The size of the tool needs to be the same as the processing zone. However, the electrode of the tool is required to be a good conductivity metal, which is expensive. Based on the cost, in this study, I try to reduce the size of the tool along with a moving speed. The electric field model with temperature field and flow field of through-mask electrochemical micro-machining with a moving tool is simulated by using finite element method. Effects of parameters, such as: applied voltage, velocity of electrolyte, mask thickness and moving speed etc…, on the resulted holes are investigated.
The simulation results show that the higher the voltage, the deeper the processing depth, and the island ratio decreases with the increase of voltage; the lower the electrolyte flow rate, the higher the electrolyte temperature in the processing zone, and the island ratio increases; the mask thickness increases. Thicker, the better the shielding ability of the mask, the smaller the local current density, the shallower the processing depth, the smaller the island ratio; the slower the moving speed, the longer the processing time, the deeper the processing depth, the more uniform, the island ratio the smaller. Compared to the same machining depth, the fixed tool has less machining time than the moving tool, but the moving tool can make the machining hole have a smaller island ratio. |
