【作者】 黄春跃； 周德俭； 吴兆华；

【机构】 桂林电子工业学院机电与交通工程系；

【摘要】 建立了208脚、0．5mm 引脚间距四方扁平封装(QFP)器件焊点的三维有限元分析模型。采用非线性有限元分析方法对 QFP 三维焊点进行了应力应变分析。确定了热循环加载条件下 QFP 器件关键焊点内的热应力与应变分布以及最大塑性应变范围。基于所确定的最大塑性应变范围和 Coffin-Manson 公式,计算出了 QFP 关键焊点的热疲劳寿命。更多还原

【Abstract】 The solder joint reliability of a 0.5-mm lead pitch,208-pin quad flat package(QFP)component was studied by nonlinear finite element analysis(FEA)based on the 3-D model.The stress/strain distributions within the solder joint and the plastic strain range of the solder joint were determined.The thermal fatigue life of the solder joint was calculated using Coffin-Manson equation based on the calculated plastic strain range.The results show that the stress and strain distribution in the solder joint are not uniform;the interface between the lead and solder joint is the high stress and strain region,the maximum stress and stain occur at the topmost point where the solder joint intersecting with the inner side of the lead.The solder joint cracks should occur firstly at this point and propagate along the interface between the solder and the lead。更多还原