微电子封装钎料时相关本构模型的有限元实现

FINITE ELEMENT IMPLEMENTATION TO TIME-DEPENDENT CONSTITUTIVE MODEL OF SOLDER IN MICRO-ELECTRONIC PACKAGING

为便于工程应用,该文对已有的关于微电子封装63Sn-37Pb钎料合金材料的时相关变形本构模型在有限元软件ABAQUS上进行了移植。在有限元移植中,鉴于该时相关本构模型的复杂性,该文对传统的隐式算法进行了适当的修正处理,对现时内变量进行了更新;自行推导了一致切线刚度矩阵,以提高有限元程序的平衡迭代效率;对63Sn-37Pb钎料合金的多种加载工况进行了数值模拟,移植后的数值模拟结果与已得到验证过的数值模拟结果的比较表明该文的有限元移植是合理成功的;最后,作为应用的一个实例,该文对该材料的剪切结构试样进行了循环加载下的有限元模拟。

An existing time-dependent deformation constitutive model of 63Sn-37Pb solder alloy in micro-electronic packaging was implemented into ABAQUS using the interface package UMAT. Due to the complexity of this model, some modifications were made upon the traditional implicit algorithm. Based on the modification, the current internal variables were updated; the consistent tangent modulus was derived to improve the efficiency of iteration. To show the validity, various loading cases were carried out. The comparison between the implemented FEA simulations based on ABAQUS and the verified numerical constitutive modeling results of the existing model shows that the implemented FEA results coincide with the numerical constitutive simulations of the existing model perfectly. As a structural FEA example for the FEA implementation, a finite element simulation was conducted for the shear structural specimen of the material under cyclic loading.