以微陽極導引電鍍法製備銅螺旋微米結構與其機械性質分析

On the Microhelix Structures of Copper Prepared by Microanode Guided Electroplating and their Mechanical properties

顧乃華(Nai-Hua Gu)

指導教授 ： 林景崎

國立中央大學/工學院/機械工程學系/碩士(2015年)

摘要

本研究使用微陽極導引電鍍法在銅片基材上電鍍微米尺度之銅螺旋結構物。採用直徑為 75 μm 之白金絲，經樹脂鑲埋後露出 角 錐狀、圓盤狀兩種不同形狀微陽極，在含硫酸銅溶液之鍍浴中，控制微陽極與銅片間偏壓在3.4 V，並維持微陽極與銅基材（ 或螺旋結構物） 頂端之間距在 30 μm，進行微陽極導引電鍍。結果顯示：在圓盤狀微陽極電鍍所得之微螺旋的線徑均勻度較佳，隨電鍍時間增長下，粗細不均的現象較不明顯。 藉由商用 COMSOL軟體來模擬兩種不同形狀微陽極導引電鍍過程之電場分布，得知在使用圓盤形微陽極微電鍍過程，其電場分佈較適合生長線徑均勻之微螺旋。 以圓盤形微陽極導引電鍍法在製作銅螺旋之微結構時，依據 COMSOL 軟體之電場強度模擬結果與實際實驗交互比對，可以推測可行的析鍍電場強度範圍需要高於 10 kV/m 以上，此工作範圍將決定銅微螺旋之直徑與螺距之大小。當螺旋直徑由 230 μm 增加到 470 μm，微螺旋線徑會逐漸下降，且螺旋線徑均勻 度上升；螺距由 145 μm 增加到 250 μm 時，微螺旋線徑也會逐漸下降，螺旋線徑均勻度上升。本研究製程在螺旋之直徑為 390、 470 μm，螺距於215、 250 μm，可以得到均勻的銅微螺旋結構，其螺旋線徑變化量小於 10%。
若改變鍍浴中銅離子濃度使其電導率介於 5、 10、 15 及 20 S/m 之間，以圓盤形微陽極導引電鍍銅螺旋結構，結果發現鍍液之電導率 5 S/m 時，獲得之銅螺旋結構最均勻 ，其螺旋線徑增加量可低於 15%，隨著鍍液之電導率上升至 20 S/m，其螺旋線徑增加量將高達 76.3%。經微力壓縮實驗與奈米壓痕試驗來研究微螺旋之機械性質，所得銅微螺旋之硬度、楊氏模數與彈性常數接隨電鍍浴電導率上升而提高，電導率 20 S/m 之鍍液析鍍出之銅微米螺旋結構的硬度為 0.355 GPa，楊氏模數為 5.445 GPa，彈簧之彈性常數為0.775 mN/μm。

關鍵字

微陽極導引電鍍 ； 銅微米螺旋結構 ； 奈米壓痕

並列摘要

The copper microhelix was prepared by microanode guiding electroplating (MAGE) technique. A microanode was made of platinum (75 μm in diameter). The copper microhelix structure was deposited at a potential of 3.4 V. The initial gap between microanode and the top of the coils was set at a distance of 30 μm. We used two different shape of microanode (cone-liked and disk-liked) to do the electroplating. We observed that the line diameter of helix structure made with disk like microanode didn’t increase with time, and then used commercial software (COMSOL Multiphylics) to simulate the electric field of two type of microanode and verified the result of experiment. The result was that the disk like microanode had better electric filed distribution. We found that the electric field should higher than 10 kV/m when deposited the copper microhelix. This working range could decide the wire diameter of the copper microhelix. The larger helix diameter (390, 470 μm) and higher pitch (215, 250 μm) could have better wire diameter (the amount of change is less than 10%).
Then we used the disk like microanode to do the copper helix structure deposition in the bath with conductivity of 5, 10, 15, and 20 S/m, than analysed the mechanical properties with microforce compression test and nanoindentation test. In the result, copper helix structure had the best hardness (0.355 mN/μm2), Young’s modulus (5.445 GPa), and spring constant (0.775 mN/μm) at
conductivity of 20 S/m.

並列關鍵字

Microanode guided electroplating ； Copper microhelix structure ； Nanoindentation

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