环氧塑封料泊松比对球栅阵列封装可靠性的影响

The Influence of Epoxy Molding Compound Poisson’s Ratio on the Reliability of Ball Grid Array Packaging

随着电子封装行业的迅猛发展,业界对封装结构可靠性的要求也越来越严格。目前大多数人将泊松比视为定值,这将在一定程度上影响可靠性评估。为了进一步提高可靠性,适当考虑材料泊松比对封装结构的影响具有重要的工程实践意义。该文利用有限元分析法,通过设计芯片仿真和板级封装仿真,分别探究了环氧塑封料泊松比对芯片翘曲、芯片界面应力以及板级封装焊点寿命的影响。通过分析可知:环氧塑封料泊松比可变对封装结构的翘曲具有较大的影响,而且有可能造成芯片界面分层、芯片达到应力极限而损坏,此外也需要适当考虑泊松比对焊点寿命的影响。随着芯片不断向着大尺寸方向发展,研究材料泊松比将具有更为重要的意义。

With the rapid development of the electronic packaging industry,the industry’s requirements for the reliability of packaging structures are becoming more and more stringent.At present,most people regard Poisson’s ratio as a fixed value,which will affect reliability prediction to a certain extent.In order to further improve the reliability,it is of important engineering practical significance to properly consider the influence of the material Poisson’s ratio on the package structure.This paper uses finite element method(FEM),through design chip simulation and board-level packaging simulation,to explore the effects of Poisson’s ratio of epoxy molding compound on the chip warpage,chip interface stress,and the impact of board-level packaging solder joint life.Through analysis,it can be known that the variable EMC Poisson’s ratio has a greater impact on the warpage of the package structure,and it may cause the chip interface to be delamination and the chip to reach the stress limit and damage.In addition,it is necessary to properly consider the influence of Poisson’s ratio on the fatigue life of solder joints.Especially with the continuous development of chips in the direction of large size,the study of material Poisson’s ratio will have more important significance.