LGA焊点可靠性分析及热疲劳寿命预测  

LGA solder joint reliability and thermal fatigue life prediction

作　　者：金玲玥 孙海燕[1] 周婷 赵继聪 JIN Lingyue;SUN Haiyan;ZHOU Ting;ZHAO Jicong(School of Information Science and Technology,Nantong University,Nantong 226019,Jiangsu Province,China)

机构地区：[1]南通大学信息科学技术学院,江苏南通226019

出　　处：《电子元件与材料》2021年第9期893-899,共7页Electronic Components And Materials

基　　金：国家自然科学基金(61974077,61804084)。

摘　　要：针对栅格阵列封装焊点可靠性问题,设计了一种焊料包裹焊盘的倒凹槽焊点,利用有限元分析法和修正的Coffin-Manson寿命预测方程,对其热可靠性进行评估。经仿真和试验验证,初始倒凹槽焊点的热疲劳寿命是1201个周期,为常规焊点的2.08倍。进一步结合田口试验法,以倒凹槽焊点的热疲劳寿命为优化目标,建立L_(27)(3^(9))正交试验表,通过极差法计算出优化组合。结果表明:嵌入倒凹槽焊点内部的焊盘高度、焊点高度、塑封料的热膨胀系数、温度循环范围对倒凹槽焊点的热疲劳寿命影响较大;优化后的倒凹槽焊点的热疲劳寿命为4297个周期,是常规焊点的7.43倍,优化结构大幅提升了LGA焊点结构的热可靠性。To solve the reliability problems of the solder joints of land grid array(LGA),an inverted-groove solder joint was proposed with solder-wrapped pad.The thermal reliability of the solder was evaluated by using finite element analysis method and modified Coffin-Manson life prediction equation.The simulation and experimental results show that the thermal fatigue life of the initial inverted groove solder joint is 1201 cycles,which is 2.08 times that of the traditional solder joint.Furthermore,based on Taguchi test method,the L_(27)(3^(9)) orthogonal test table was established to optimize the thermal fatigue life of inverted groove solder joint,and the optimal combination was calculated by the range method.The results show that the height of the pad embedded in the inverted-groove solder joint,the height of the solder joint,the coefficient of thermal expansion of the epoxy molding compound and the temperature cycle range have significant effects on the thermal fatigue life of the inverted-groove solder joint.The thermal fatigue life of the optimized inverted groove solder joint is 4297 cycles,which is 7.43 times that of the traditional solder joint.The optimized structure greatly improves the thermal reliability of LGA solder joint.

关 键 词：LGA焊点 焊点形态 有限元分析 热疲劳寿命 田口试验法 

分 类 号：TN406[电子电信—微电子学与固体电子学]