(重庆大学 材料科学与工程学院，重庆 400044)
摘 要: 研究不同回流焊工艺下得到的球栅阵列(BGA)焊点在正弦振动疲劳试验中的失效行为。借助扫描电镜观察在不同加热因子下形成的Sn-Cu金属间化合物的形态和厚度，运用有限元模拟分析球栅阵列焊点在正弦振动下的应力集中和分布。结果表明：当金属间化合物层的形态和厚度不同时，裂纹的萌生和扩展机理不同；随着金属间化合物层厚度的增加，焊点的振动疲劳寿命先是缓慢提高，随后急剧下降；当金属间化合物层的厚度为1.5~3.0 μm时，接头的振动疲劳寿命达到最大值。
关键字: 金属间化合物；球栅阵列；振动；疲劳寿命
（School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China）
Abstract:The sinusoidal vibration failure behavior of ball grid array(BGA) solder joints reflowed with different temperature profiles was studied. The morphologies and thickness of Sn-Cu intermetallic compound (IMC) formed under diverse heating factor were observed by scanning electron microscopy. The stress concentration and distribution of BGA solder joints under the sinusoidal vibration were analyzed by finite element simulation. The results show that the origin and propagation of cracks mechanism differs when the morphologies and thickness of IMC layer are different. The vibration fatigue lifetime of solder joints increases gradually at first and then drops rapidly with the increase of the thickness of IMC layer, reaching the maximum when the thickness of IMC layer is about 1.5-3.0 μm.
Key words: intermetallic compound; ball grid array; vibration; fatigue lifetime
