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

黃冠傑(Kuan-Chieh Huang)

指導教授 ： 吳樸偉 ； 林鵬

國立交通大學/工學院/材料科學與工程系所/碩士(2011年)

https://doi.org/10.6842/NCTU.2011.00833

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。

關鍵字

無鉛銲錫 ； 電化學 ； 電鍍 ； 凸塊下金屬層

並列摘要

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.

並列關鍵字

Solder bump ； Electrochemistry ； Electroplating ； UBM

參考文獻

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