製作微流道之電化學加工用銅電極絕緣材料被覆製程研究

STUDY OF INSULATING MATERIAL COATING PROCESSES FOR COPPER ELECTRODES USING IN MICRO FLOW CHANNELS FABRICATION

楊金水(Chin - Shui Yang)

指導教授 ： 李碩仁

元智大學/工程學院/機械工程學系/碩士(2009年)

摘要

本研究展現一種放電加工用電極的創新製程。該電極將用於製造質子交換膜燃料電池流場板上之微流道。
首先以銑製加工方法於銅質電極上製作彎曲形狀的流道，然後於電極上被覆一層電絕緣材料。本研究以實驗探討二種絕緣材料與被覆製程。第一種方法是以大氣電漿噴塗氧化鋁陶瓷粉末於電極表面。第二種方法是以電漿輔助化學氣相沉積法PACVD 又叫 PECVD
電極表面產生類鑽碳膜。
為了於流道板上產生微小之流道，只允許電極上最高部位可以導電，該最高部位於放電加工時用以放電加工產生對應之微流道。因此，電極上最高部位被覆之電絕緣材料再以車製加工方法加以移除，使絕緣材料底下之銅質顯露出來。此外，為了避免於車製加工過程中，造成緊臨車製區域之絕緣材料剝離，本研究也採用易熔金屬，首先將電極置於模具內，然後加熱易熔金屬使成為熔融狀態後，澆灌於模具內，俟易熔金屬降溫成固態後，再加以車製加工，移除電極上最高部位之絕緣材料，之後再加熱熔化易熔金屬，並取出電極。
本研究使用自製之微電化學加工機加工，該機由陰極進給裝置、陰陽極夾治具、電源供應系統、電解液噴流、過濾裝置與抗腐蝕鋼骨加工基台等五大部分所組成。運用該機於厚度600µm之304不鏽鋼片上加工，以成功製作出深度500µm，寬度200µm之微流道，並且獲得量產電極與流道板之製作程序與有關之技術參數。

關鍵字

熱噴塗層 ； 類鑽碳膜 ； PECVD ； 微電化學加工

並列摘要

A procedure was presented in this study was an innovative fabrication process of the metallic copper electrode. This electrode was employed to fabricate the micro flow channels of a flow field plate of a PEM fuel cell by the electrochemical micro machining (EMM) process. The shap and geometries of copper electrode was fabricated by milling process. Then, the electrode was coated with an electric insulated thin film. In order to understand the adhesion between the copper electrode and insulated thin film, two kinds of insulated materials and coating processes were studied in this thesis. First, the electrode was coated with the alumina powder (Al2O3) by atmospheric-pressure plasma spray. Second, a Diamond Like Carbon thin film coated on the electrode by the Plasma Enhanced Chemical Vapor Deposition (PECVD) process.
Due to the following flow channel EMM fabrication process, the insulated thin film on the top surface of the electrode was removed by the lathing process. Meanwhile, a proper molding process was employed to prevent the insulated thin film peeling off on the side wall of the electrode during lathing process.
In the flow channel EMM fabrication process, an EMM machine center was conducted. It includes cathode feeding apparatus, cathode/anode fixture electric power system, electrolyte flow and filter, and anti-corrosion structure of the center.
The results of flow channel fabrication process showed that the 600µm thick SUS304 stainless steel flow field plate had an uniform flow field. The dimensions of each flow channel were 500µm of depth and 200µm of width.

並列關鍵字

Hot Spray Coating ； Diamond Like Carbon film ； PECVD ； Micro Electrochemical Machining

參考文獻

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