【摘要】：研究了稀土元素Eu對SnAgCu無鉛釬料組織與性能的影響。結果表明:微量的稀土元素Eu可以顯著提高無鉛釬料在銅基板表面的潤濕性和QFP256器件無鉛焊點力學性能,稀土的最佳添加量為0.04%左右;當稀土元素含量高于0.04%,無鉛釬料的鋪展面積和無鉛焊點拉伸力均明顯下降;對釬料的基體組織研究發(fā)現(xiàn)稀土元素的添加可以顯著細化β-Sn基體組織,金屬間化合物顆粒尺寸也明顯減小。同時在150℃時效(1000 h)過程中,SnAgCu和SnAgCu-0.04Eu兩種釬料的基體組織均發(fā)生明顯的粗化,特別是Cu6Sn5顆粒明顯較為粗大;但是相對SnAgCu釬料,SnAgCu-0.04Eu釬料的組織粗化程度明顯較小。稀土元素添加過量時,釬料的潤濕性、力學性能明顯惡化,基體組織出現(xiàn)明顯的錫須,添加微量稀土Eu時,并未發(fā)現(xiàn)錫須。含稀土SnAgCu釬料表面生長錫須,可以采用"氧化膜破裂機制"解釋這種現(xiàn)象,稀土相因為氧化體積明顯增大,那么內(nèi)部就會產(chǎn)生較大的壓應力,壓應力即為錫須生長的驅(qū)動力。
[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，

本文編號：2466912