| 摘要: | 電化學微加工（Electrochemical Micro-Machining，EMM），屬於非傳統加工方法的一種，以電解現象達成加工成形之目的，其優點為加工速度快、加工不受材料硬度限制、工件無表面應力殘留及表面粗糙度佳的優勢，具有相當的發展潛力與高附加價值。然而，一般電化學微加工會因成品要求而負擔較昂貴的刀具設計費用，但遮罩式電化學加工（Through-Mask Electrochemical Machining，TMEMM）所用之刀具則不受成品形狀之影響，可在相同刀具下，透過絕緣遮罩，並依成品之形狀改變其遮罩形狀，即可完成加工，因此可省下刀具設計費用。
本研究採用紅銅作為刀具，以不鏽鋼304薄板(0.1 mm)作為工件，使用網版印刷製程製作遮罩。本研究之目的為觀察電解液流向對加工外觀的影響，並以田口統計法作為分析工具，探討遮罩式電化學加工參數（電解液濃度、操作電壓、遮罩孔洞直徑、遮罩厚度）對單孔底切與陣列孔均勻度的影響趨勢，最後再從中評估出最佳參數組合。
實驗結果可以發現，加工外觀在使用正向流模式時加工形狀較圓，而使用側向流模式時加工形狀會因電解液流向呈現橢圓形，因此本文選定正向流模式進行後續實驗。
另外，由變異數分析可以發現，影響單孔底切與陣列孔均勻度最高的實驗參數均為遮罩孔洞直徑與遮罩厚度，同時從研究中順利取得一組最佳參數，單孔底切實驗之最佳參數組合為A2B1C1D1，底切量為72 μm，陣列孔均勻度實驗之最佳參數組合為A2B3C1D3，平均偏差量為7 μm。
;Electrochemical micro-machining (EMM) is one of the non-traditional manufacturing processes, shaping workpieces by electrolysis. The advantages include high processing speed, independent of metal properties, no surface residual stress, and smooth workpiece surface with enormous potentialities and highly added values. However, normal electrochemical micro-machining will afford higher expense because of the demand of the end product. The design expense of the electrode tool can be saved if using through-mask electrochemical machining (TMEMM). The purpose of using TMEMM is that the electrode tool won’t be affected by the end product shape. Without changing the electrode tool, TMEMM can fulfill end product, with any shape by only changing the shape of the electric insulated mask.
In this study, copper is selected as the electrode tool, and a SUS 304 thin plate (0.1 mm) is taken as workpiece. Masks are made by using the screen printing process. The object of this research was to observe the effects of the electrolyte flow direction on through holes shape, and Taguchi Statistical Method is used to analyze the influences of parameters (e.g.: electrolyte concentration, applied voltage, diameter of the mask hole, and the thickness of the mask) on the undercut of single hole and uniformity of array holes, and estimate the best combination of parameters.
According to the results of the experiments, end product (drilled holes) is closer to a circle by using the forward flow mode. On the other hand, if we using the lateral flow mode, the shape of the end product will be more close to an oval profile. Therefore the forward flow mode is selected as the basis for the flowing experiments.
Furthermore, by the analysis of variance (ANOVA), it is found that the highest impact factors on the undercut of single hole and uniformity of array holes are the diameter of the mask hole and the thickness of the mask. And the best parameter combination is simultaneously acquired from the research. The best parameter combination for a small the undercut of single hole is A2B1C1D1, and the corresponding of undercut is 72 μm. The best parameter combination for the most uniformity of array holes is A2B3C1D3, and the corresponding averaged deviation is 7 μm. |
