(1. 大連理工大學(xué) 材料科學(xué)與工程學(xué)院，大連 116024；
2. 大連理工大學(xué) 遼寧省先進連接技術(shù)重點實驗室，大連 116024)
摘 要: 研究金屬離子與絡(luò)合劑摩爾濃度比、pH值及電鍍溫度對Au、Sn鍍層表面形貌及其鍍速的影響。通過分步法電鍍Au/Sn/Au三層結(jié)構(gòu)薄膜，并回流制備Au-Sn共晶凸點。結(jié)果表明：鍍Au過程中，隨著Au離子與亞硫酸鈉摩爾濃度比的增加，Au鍍層晶粒細化，并在摩爾濃度比為1:6時獲得了最快的沉積速度；當電鍍溫度較低時，鍍Au層表面呈多孔狀，隨著溫度的升高，鍍層致密性增加，晶粒也趨于圓滑。鍍Sn過程中，隨著Sn離子與焦磷酸鉀摩爾濃度比的增大，鍍層表面起伏加劇，鍍層孔洞增多。當pH值為8.0時，鍍層平整致密，隨著pH值的增高，析氫反應(yīng)加劇，Sn離子水解，導(dǎo)致鍍層質(zhì)量下降。運用分步法電鍍制備的Au/Sn/Au三層結(jié)構(gòu)薄膜均勻，回流得到了具有典型共晶組織的Au-Sn凸點。
關(guān)鍵字: 金；錫；分步法電鍍；回流；共晶組織；凸點
（1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
2. Key Laboratory of Liaoning Advanced Welding and Joining Technology,
Dalian University of Technology, Dalian 116024, China）
Abstract:The effects of molar concentration ratio of metal ion to complexing agent, pH value and electroplating temperature on the morphology and the plating rate of gold and tin films were investigated. The Au/Sn/Au triple-layer films were prepared by sequential electroplating, and the Au-Sn eutectic bumps were obtained by reflowing the triple-layer films. The results show that the grain size of gold films becomes fine with increasing molar ratio of gold ion to sodium sulfite, and the fastest plating rate is obtained when the molar concentration ratio is 1:6. The gold films are porous at a low temperature, but become dense and smooth with increasing temperature. The tin films become coarsening with more voids with increasing molar ratio. When the pH value is 8.0, the tin films are even and compact. When the pH value is further increased, the quality of tin films gets worse due to the hydrogen revolution reaction and the hydrolysis of tin ions. The Au/Sn/Au triple-layer films prepared by sequential electroplating are uniform, and the Au-Sn bumps with typical eutectic structure are obtained by reflowing the triple-layer film.
Key words: Au; Sn; sequential electroplating; reflow; eutectic structure; bump
