即時影像監控下微陽極導引連續電鍍銅–鋅合金微柱並研究其結構與奈米硬度

Study on the Structure and Nano Hardness of Cu-Zn Alloying Micro Pillars Fabricated by Continuous Microanode-guided Electrochemical Plating Monitored with Real-time Imaging

本文以即時影像導引法自焦磷酸鹽鹼性鍍浴中，經連續式電鍍成功製備出銅鋅合金微柱，進而研究其結構及奈米硬度。過程中改變微電鍍製程之實驗參數如電極間距、兩極間偏壓和鍍浴中銅離子濃度進行電鍍，所製得之合金微柱，以感應耦合電漿質譜儀（ICP-MS）分析其組成、掃描式電子顯微鏡（SEM）觀察其形貌、X光繞射儀（XRD）解析其晶體結構、合金相，並以奈米壓痕儀測試其奈米硬度。結果顯示：偏壓在4.4 V時，若兩極間距由15增加到30μm，所得微柱之表面形貌由粗糙轉變成平滑；微柱組成中鋅含量由23.51減低到14.34at.%；由奈米壓痕測得之縱剖面硬度將獲得提升。當兩極間距固定在25μm，偏壓若由4.3增加到4.6 V，則微柱成分中鋅含量由15.88 at.%增加到34.83 at.%，且硬度增加。當兩極間距在25μm且偏壓在4.4 V時，若鍍浴中銅離子濃度由0.005 M增加到0.04 M，所得微柱之鋅含量與硬度均會降低。

Copper-zinc (Cu-Zn) alloying micro pillars were fabricated by continuous microanode-guided electroplating (CMGE) in pyrophosphate bath under real-time monitoring. Parameters such as the gap between electrodes, the applied voltage between electrodes and the copper concentration in the bath influence on the surface morphology, composition, microstructure and mechanical property of the micro pillars were investigated. Surface morphology of the micro pillars was examined by SEM, composition and microstructure were determined by ICP-MS and XRD, respectively. The nano hardness was determined by nano indentation. In the case of CMGE carried out at 4.4 V, the alloying micro pillars fabricated revealed a smooth surface morphology and their Zn-content indicated a slight decrease (i.e., from 15.88 at. % to 14.34 at. %) as the electrode gap increased from 15 μm to 30 μm. The nano hardness increased along the longitudinal section of the micro pillars. In the case with the electrode gap setting at 25 μm, the micro pillars inclined to be smoother in surface morphology and their Zn-content to increase from 15.88 at. % to 34.83 at.% with increasing the applied voltage from 4.3 V to 4.6 V. The nano hardness increased as well. Under the condition with voltage of 4.4 V and the electrode gap at 25 μm, the micro pillars fabricated were found to decrease their Zn-content and diminish the nano hardness with increasing the copper concentration from 0.005 to 0.04 M in the bath.