稀土元素Eu对SnAgCu钎料组织与性能影响

发布时间：2019-04-27 10:47

【摘要】：研究了稀土元素Eu对SnAgCu无铅钎料组织与性能的影响。结果表明:微量的稀土元素Eu可以显著提高无铅钎料在铜基板表面的润湿性和QFP256器件无铅焊点力学性能,稀土的最佳添加量为0.04%左右;当稀土元素含量高于0.04%,无铅钎料的铺展面积和无铅焊点拉伸力均明显下降;对钎料的基体组织研究发现稀土元素的添加可以显著细化β-Sn基体组织,金属间化合物颗粒尺寸也明显减小。同时在150℃时效(1000 h)过程中,SnAgCu和SnAgCu-0.04Eu两种钎料的基体组织均发生明显的粗化,特别是Cu6Sn5颗粒明显较为粗大;但是相对SnAgCu钎料,SnAgCu-0.04Eu钎料的组织粗化程度明显较小。稀土元素添加过量时,钎料的润湿性、力学性能明显恶化,基体组织出现明显的锡须,添加微量稀土Eu时,并未发现锡须。含稀土SnAgCu钎料表面生长锡须,可以采用"氧化膜破裂机制"解释这种现象,稀土相因为氧化体积明显增大,那么内部就会产生较大的压应力,压应力即为锡须生长的驱动力。
[Abstract]:The effect of rare earth element Eu on the microstructure and properties of SnAgCu lead-free solder was studied. The results show that the wettability of lead-free solder on the surface of copper substrate and the mechanical properties of lead-free solder joint of QFP256 device can be significantly improved by trace amount of rare earth element Eu. The optimal addition of rare earth is about 0.04%. When the content of rare earth elements is higher than 0.04%, the spreading area of lead-free solder and the tensile force of lead-free solder joint decrease obviously. The matrix structure of filler metal was studied. It was found that the addition of rare earth elements could obviously refine the matrix structure of 尾-Sn and decrease the particle size of intermetallic compound. At the same time, during aging at 150 鈩，

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