標題: | 電化學沉積法於超細間距微無鉛銲錫凸塊的開發 Development of Electrochemical Deposition for Extra-fine Pitch Micro Lead-free Solder Bumps |
作者: | 黃冠傑 Huang, Kuan-Chieh 吳樸偉 林鵬 材料科學與工程學系 |
關鍵字: | 無鉛銲錫;電化學;電鍍;凸塊下金屬層;Solder bump;Electrochemistry;Electroplating;UBM |
公開日期: | 2011 |
摘要: | 本研究於超細間距20μm,直徑12μm的孔洞依序電鍍銅、鎳及錫銀合金於指定規格:銅厚度5μm,鎳厚度3μm,錫銀合金5μm,作為無鉛銲錫凸塊以及凸塊下金屬層的製備。錫銀合金的成份為Sn-2.5 wt% Ag,電鍍完成後經由迴銲將凸塊熔成球形,再以高解析度電子微探儀分析其中組成,我們發現電流密度會對錫銀合金凸塊表面形貌造成巨大的影響,無鉛銲錫凸塊經由配方和參數的調整可以成功電鍍,填孔率超過99.5%,並且成分誤差控制在0.2 wt%之內。 In this study, a Cu/Ni UBM and lead-free solder for 20 μm pitch micro-bump has been attempted to fabricate via consecutive electroplating of Cu, Ni and binary SnAg in specification on a patterned wafer. The targeted thickness of Cu and Ni are 5 μm and 3 μm for the preparation of UBM, and the thickness of the SnAg solder bump is 5 μm with 2.5 wt% Ag composition. After the electroplating process, the solder undergoes a reflow process to obtaining spherically-shaped bumps. Electron Probe Micro-analyzer (EPMA) is carried out to evaluate relevant material properties. We observe a strong effect for the plating current density on the resulting bump morphologies. After adjusting relevant parameters, the formation of 5 μm Cu/3 μm Ni/5 μm Sn-2.5 wt% Ag bumps can be successfully fabricated, and the spherically-shaped solder balls are confirmed with composition variation within 0.2 wt% deviation. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079818553 http://hdl.handle.net/11536/47380 |
Appears in Collections: | Thesis |
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