(河南科技大学 材料科学与工程学院，洛阳 471003)
摘 要: 利用X射线衍射分析仪(XRD)和JSM-5610LV扫描电镜(SEM)研究RE含量对Sn2.5Ag0.7Cu/Cu焊点界面区显微组织、剪切强度和蠕变断裂寿命的影响。结果表明：Sn2.5Ag0.7CuxRE焊点界面区金属间化合物由靠近钎料侧Cu6Sn5和靠近Cu基板侧Cu3Sn构成；添加微量RE可细化Sn2.5Ag0.7Cu焊点内钎料合金的显微组织和改善钎焊接头界面区金属间化合物的几何尺寸及形态；当RE添加量为0.1%时，焊点的剪切强度最高，蠕变断裂寿命最长。
关键字: Sn2.5Ag0.7CuxRE/Cu焊点；显微组织；剪切强度；蠕变断裂寿命
（College of Material Science and Engineering, Henan University of Science and Technology,
Luoyang 471003, China）
Abstract:The effects of rare earth (RE) on the microstructure, shear strength and creep rupture life of the Sn2.5Ag0.7Cu/Cu solder joints were investigated by X-ray diffractometry, JSM-5610LV scanning electronic microscopy. The results show that the intermetallic compound (IMC) interfacial layer of soldered joints between Sn2.5Ag0.7CuxRE lead-free solder and copper substrate usually includes two parts of Cu6Sn5 near the solder alloy, and Cu3Sn nearside the Cu substrate. Adding tiny RE in Sn2.5Ag0.7Cu lead-free solder alloy can refine the microstructure of the solder joints and affect the size and configuration of the IMC of interfacial layer. When the RE adding content of Sn2.5Ag0.7Cu solder alloy is 0.1% in mass fraction, the shear strength of the solder joint is the highest and its creep rupture life is the longest.
Key words: Sn2.5Ag0.7CuxRE/Cu solder joints; microstructure; shear strength; creep rupture life
