與Cu基板間界面IMC的影響
(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究Sn-0.7Cu-0.5Ni-xCe(x=0，0.1)焊料與銅基板間543 K釬焊以及453 K恒溫時效對界面金屬間化合物(IMC)的形成與生長行為的影響。結(jié)果表明：往Sn-0.7Cu-0.5Ni焊料合金中添加0.10%Ce，能抑制等溫時效過程中界面IMC的形成與生長；焊點最初形成的界面IMC為Cu6Sn5，時效10 d后，Sn-0.7Cu-0.5Ni和Sn-0.7Cu-0.5Ni-0.10Ce這2種焊料中均有Cu3Sn形成，與Sn-0.7Cu-0.5Ni/Cu焊點相比，Sn-0.7Cu-0.5Ni-0.10Ce/Cu界面IMC層較為平整；該界面IMC的形成與生長均受擴(kuò)散控制，主要取決于Cu原子的擴(kuò)散，添加稀土元素Ce能抑制Cu原子的擴(kuò)散，Sn-0.7Cu-0.5Ni和Sn-0.7Cu-0.5Ni-0.10Ce焊點界面IMC層的生長速率分別為6.15×10−18和5.38×10−18 m2/s。
關(guān)鍵字: 無鉛焊料；界面反應(yīng)；等溫時效；IMC；生長率
at Sn-0.7Cu-0.5Ni/Cu interface
（School of Materials Science and Engineering,Central South University, Changsha 410083, China）
Abstract:Intermetallic compound(IMC) formation and growth of Sn-0.7Cu-0.5Ni solder with addition 0.1% Ce were studied for Cu-substrate during soldering at 543 K and isothermal aging at 453 K. The results show that addition of 0.1% Ce into Sn-0.7Cu-0.5Ni solder inhibits the excessive formation and growth of intermetallic compounds during the soldering reaction and thereafter under aging condition. The intermetallic compound layer formed firstly at the interface is Cu6Sn5, after 10 d of aging a thin Cu3Sn layer is also observed for both solders. After several days of aging, Sn-0.7Cu-0.5Ni-0.1Ce solder gives comparatively planar intermetallic layer at the solder-substrate interface than Sn-0.7Cu-0.5Ni solder. The formation of intermetallic compounds during aging for both solders follows the diffusion control mechanism. Intermetallic growth rate constants for Sn-0.7Cu-0.5Ni and Sn-0.7Cu-0.5Ni-0.1Ce solder are 6.15×10−18 and 5.38×10−18 m2/s, respectively, which has significant effect on the growth behavior of intermetallic compounds during aging.
Key words: lead-free solder; interfacial reaction; isothermal aging；IMC; growth rate
