本研究嘗試以直徑為125μm的鉑絲當作參考電極來監測及解析微電析鎳的過程。所謂微電析鎳是在瓦茲鍍浴中，以一單軸垂直步進運動之鉑絲（直徑125μm）陽極，在銅片上以直流及脈衝方式電析微小鎳柱之過程。在微電析鎳過程中，由於鉑絲參考電極比傳統飽和甘汞參考電極更能量測陰極局部電位，藉由監測電析過程中的局部陰極電位變化，研判解析可作為陰極表面鎳析鍍物形貌改善的基礎。 鉑絲參考電極監測脈衝間歇微電析鎳的結果顯示：（1）陰極的局部及整體電位會受試片不同表面處理而改變。（2）當陰陽極間施加偏壓>5.0V（－1760±7 mVpt）以上可以析鍍出鎳柱，在5.6∼6.0V（－1919±11∼－1989±11 mVpt）時所得鎳柱組織細緻且直徑均勻。在偏壓>6.0V的鎳柱成長速度最快。（3）適當控制脈衝間歇微電析之條件可控制微鎳柱成長達成平台式結構。 鉑絲參考電極監測在不同陰陽極間距下之定電位直流下之微電析，結果顯示：（1）由定電位微電析推估而得之陰極極化曲線，對陰陽極間間距的改變較具可分辨性，此種特性可用來修正動態陰極極化掃瞄曲線結果。（2）陰極電流的大小影響鎳析鍍物的顆粒粗細，電場強度則會影響鎳析鍍物的外貌。 利用鉑絲參考電極針對鎳微電析過程進行交流阻抗之監測與解析，結果顯示：（1）鎳微電析和傳統電鍍鎳均隨外加偏壓之增大而極化電阻減小，但電雙層電容增大。（2）由於鎳微電析的電場強度（約1000V?m）約為傳統鎳電鍍（約30V?m）之30倍，因此質傳效應較顯著。（3）鎳微電析的極化電阻值（約0.01Ω?cm2）比傳統鎳電鍍之極化電阻值（約103∼10－1Ω?cm2）小。 A piece of platinum wire (diameter 125μm) was used as a reference electrode to monitor the potential variation of the cathode in the nickel micro electroplating, Ni-microelectroplating was carried out in a Watts bath using the platinum wire (diameter 125μm) as the anode and pure copper (10mm×10mm) as the cathode. The pt-anode was mounted in an epoxy resin which was driven by a micro step-motor to move perpendicularly to the cathode surface inμm. DC (direct current) and PC (pulse current) microelectroplating had been monitored by the platinum reference electrode. It was found that pt electrode is more proper than SCE (saturated calomel electrode) to be a reference for measurement the local potential of the cathode. The analysis of the variation of local potential of the cathode is helpful for choose optimal conditions to obtain a column deposit of nickel with fine grain and uniform diameter. Monitoring of the pulse-current microelectroplating of nickel by pt-reference electrode indicates the results: (1) The local and bulk potentials for the cathode are influenced by its surface treatment, and the outset potential for Ni-micro electroplating is also affected by the surface treatment. (2) Micro electroplating of nickel on copper starts initially at a bias >5V (>－1760±7 mVpt); it grows into fine grains in a constant diameter at bias between the 5.6 ~ 6.0V (in the range－1919±11∼－1989±11 mVpt), and the growth rate of the Ni-microdeposition is practically accepted. (3) A cylindrical Ni-platform is obtained by conducting the PC-microelectroplating at optimal conditions control. Monitoring of the DC-potentiostatic Ni-microelectroplating by pt-reference electrode demonstrates the following results: (1) The cathodic polarization curve results from the potentiostatic experiments is better than that from potentiodynamic cathodic polarization. (2) The magnitude of the cathodic current affects he grain size of the microdeposit, and the electric field between the cathode and the micro-anode affects the shape of the Ni-micro deposit. The exploration of electrochemical impedance spectroscopy for Ni-micro electroplating by using pt as a reference electrode exhibits: (1) The polarization resistance (Rp) decreases but the capacitance of the double layer (Cdl) increases with increasing the bias applied for both the traditional Ni-plating and Ni-microplating. (2) The electric field is much greater for the micro plating (about 1000 V/m) than for the traditional plating (about 30 V/m), thus mass-transport limiting is more remarkable. (3) The magnitude of Rp is relatively negligible as compared this microelectroplating (about 0.01Ω?cm2) with traditional electrodeposition (about 103∼10－1Ω?cm2).
