Thermo mechanical fatigue and damage have been always an issue for solder joint materials used in microelectronics. Accurate damage and crack prediction is important to define the life cycle of these joints. This paper provides a finite element modeling approach used in combination with continuum damage model in order to determine damage level, update material’s constituent properties and to predict the damage initiation, damage propagation and time in Low Profile Quad Flat Package solder joint. The successive initiation and propagation of a crack is calculated by a non-linear visco-plastic finite element model. Based on the amount of damage they incur in each stage, their constitutive properties are upgraded. Mesh elements with successive damage are suppressed from the structure. The results of finite elements analysis show that they are softened and can therefore stand more stress as the elements accumulate damage leading to the decrease of damage accumulation level. The initiation site and propagation path were showed very accurately and were confirmed experimentally with scanning electron microscopy.

对于微电子学中使用的焊点材料，热机械疲劳和损坏一直是一个问题。准确的损坏和裂纹预测对于定义这些接头的生命周期很重要。本文提供了一种与连续损伤模型结合使用的有限元建模方法，以便确定损伤程度，更新材料的成分特性并预测薄型四方扁平封装焊点中的损伤发生，损伤传播和时间。裂纹的连续萌生和扩展是通过非线性粘塑性有限元模型计算的。根据它们在每个阶段所遭受的损害程度，可以升级其本构特性。从结构中抑制了具有连续损坏的网格单元。有限元分析的结果表明，它们会被软化，因此随着元素累积损伤而承受更大的应力，从而导致损伤累积水平降低。起始位点和传播路径显示得非常准确，并通过扫描电子显微镜进行了实验证实。