温度循环条件下微弹簧型CCGA焊柱的热疲劳寿命仿真研究

Simulation Study on Thermal Fatigue Life of Microcoil Spring CCGA Solder Column Under Temperature Cycle

对比封装体不同的热疲劳寿命预测模型,选择适用于微弹簧型陶瓷柱栅阵列(CCGA)封装的寿命预测模型,并对焊点的热疲劳机制进行分析。利用Workbench对焊点进行在温度循环载荷作用下的热疲劳分析。对比不同热疲劳寿命预测模型的结果,表明基于应变能密度的预测模型更适用于微弹簧型CCGA。随后对等效应力、塑性应变、平均塑性应变能密度和温度随时间变化的曲线进行分析,结果表明,在温度保持阶段,焊柱通过发生塑性变形或积累能量来降低其内部热应力水平,减少热疲劳损伤累积;在温度转变阶段,焊柱的应力应变发生剧烈变化,容易产生疲劳损伤。

Compared with different thermal fatigue life prediction models of the packages, the life prediction model suitable for microcoil spring ceramic column grid array(CCGA) packaging was determined. Then the thermal fatigue mechanism of solder column was analyzed. Workbench was used to study the thermal fatigue of solder column under temperature cycle. Compared with the results of different thermal fatigue life prediction models, it showed that prediction model based on strain energy density was more suitable for microcoil spring CCGA. Then, the curves of equivalent stress, plastic strain, average plastic strain energy density and temperature with time were discussed. It indicated that the solder joints reduced its internal thermal stress level and the accumulation of thermal fatigue damage through plastic deformation or energy accumulation at temperature holding stages. At temperature transition stages, the stress and strain of solder joints changed sharply, which was intend to produce thermal fatigue damage.