为了实现球栅阵列(BGA)封装焊点寿命的快速工程估算,建立了焊点的简化应力分布解析模型,利用蠕变寿命预测模型求解得到其热疲劳寿命.在需要精确预计焊点寿命时,建立了BGA封装焊点的三维有限元模型,利用ANSYS中的Anand方程得到焊点应力分布,利用Darveaux寿命预测模型预测焊点热疲劳寿命.采用ANSYS的二次开发功能将解析和有限元方法综合在主程序中.不论是快速估算还是精确预计,用户只需输入封装及焊点的尺寸、材料参数以及温度循环参数即可得到焊点寿命.结果表明,解析模型对参数变化更敏感,有限元的结果则较平稳.%To quickly estimate the soldered joint lifetime of the ball grid array package, the analytical model of the simplified stress distribution was founded and the thermal fatigue lifetime was calculated by the creep lifetime prediction model. When the precise results were needed, the three dimensional finite element model was founded and the stress distribution in soldered joint was calculated by Anand constructive function of ANSYS, then the thermal fatigue lifetime was given by the Darveaux model. The analytical method and the finite element method were integrated to a main program by the secondary development function of ANSYS. With this program, the lifetime of the soldered joint can be quickly estimated or precisely predicted with the packaging and soldered joint dimension, material parameters and the thermal cycle parameters. Results of the case show that the analytical model results are more sensitive to the variation of the parameters, while the analyzed results by finite element model are stable.
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