温循载荷作用下电路板焊点的寿命评估

摘要

针对某CQFP封装形式的电路板在温循载荷作用下焊点开裂的现象，利用焊料的蠕变本构模型对其采用有限元方法进行分析计算，发现结构的最大蠕变应变位于引线边角焊点的上表面处，与试验现象符合。同时，采用应变疲劳模型对结构的寿命进行评估，计算的循环次数和试验吻合较好，为故障现象的机理研究及改进提供了一定的理论和方法支撑。%In light of the cracking phenomenon of the solder joints on CQFP package circuit board under the cycle temperature load, this paper analyzes and calculated it according to the solder creep constitutive model and the method of finite elements, then find out that the maximum creep is located at the corner solder wire on the surface, which is coincided with the experimental phenomena, and so is the result of the life assessment of structure under the strain fatigue model. The methods and results of this paper provide the research of fault mechanism and its improvement with theory and method supports.