電鍍法製備覆晶封裝用銅-錫銀凸塊之研究

Preparation Of Cu-SnAg Bump For Flip Chip Package Using Electroplating Process

劉彥君(Yen-Chun Liu)

指導教授 ： 施幸祥

大同大學/工程學院/化學工程學系所/碩士(2010年)

摘要

本研究利用不同的電鍍銅添加劑進行銅電鍍製程+錫銀電鍍進行製造符合覆晶封裝的銅+錫銀凸塊，生成凸塊高度100μm、直徑100μm的銅-錫銀(Cu-SnAg)合金 (Cu 70μm + SnAg 30μm) 凸塊，電鍍實驗條件可分為定電流，添加不同的電鍍Cu添加劑進行電鍍製程，在完成銅電鍍之後進行相同條件的錫銀電鍍，而後完成各階段的電鍍後以光學顯微鏡觀察表面狀況，並以濕蝕刻（wet etching）方式進行蝕刻將表面的乾膜光阻及UBM Cu/Ti以化學藥液去除乾淨，而後將凸塊進行迴銲（Reflow）的製程，完成製程後將凸塊以掃描式電子顯微鏡(Scanning Electron Microscopy，SEM)觀察經電鍍、蝕刻製程後凸塊內部微觀結構以及進行剪應力測試分析凸塊接合強度，確認表面球級的情況。由實驗結果可以發現到，添加不同的銅添加劑對凸塊結構會構成影響，且銅電鍍後表面粗糙度會有所不同，凸塊推力測試顯示凸塊與基板之剪應力（Shear test）強度約介150～230Nt/mm2，符合業界剪應力測試標準，而電鍍結構也符合工業上覆晶封裝製程所要求的規範。

關鍵字

銅-錫銀凸塊 ； 覆晶封裝 ； 電鍍法 ； 剪應力測試

並列摘要

The study is to manufacturing Cu-SnAg alloy bump for filp-chip bonding using different copper additives in the constant-current Cu+SnAg electroplating process. Both the height and diameter of the bump are 100μm.(Cu 70μm + SnAg 30μm).
After every electroplating process, the bump’s surfaces are observed by optical microscopy. Dry film surface and the UBM Cu/Ti are removed by wet-etching and specific chemical solutions. Then the Cu-SnAg bump is treated by reflow process and investigates by SEM and shear test to realize and analyses the microstructure and bonding strength.
The result can be found that adding different Cu-additives in the Cu-electroplating process will affect the surface roughness, microstructure and shear strength of the bump. The value of the shear strength is between 150 and 230 Nt/mm2. They all coincide with the industry standards and pass the requirement.

並列關鍵字

Cu-SnAg Bump ； Flip-Chip ； Electroplating ； shear test

參考文獻

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