用内聚力模型研究PBGA封装焊点/IMC界面的分层开裂  

STUDY ON SOLDER/IMC INTERFACE DELAMINATION OF PBGA BASED ON CZM METHOD

作　　者：徐林[1] 魏俊红[1] 安群力[1] 陈建桥[1] 

机构地区：[1]华中科技大学力学系,工程结构分析与安全评定湖北省重点实验室,武汉430074

出　　处：《固体力学学报》2014年第4期400-409,共10页Chinese Journal of Solid Mechanics

基　　金：航空科学基金项目(20110279001)资助

摘　　要：塑料球栅阵列封装PBGA的可靠性分析中,考虑封装过程中SnAgCu焊料与铜焊盘界面间产生的金属间化合物(Intermetallic compound,IMC)的影响,并引入内聚力模型(Cohesive zone model,CZM),利用ANSYS对热循环作用下焊点/IMC界面的脱层开裂情况进行研究.结果表明:热循环作用下,在封装器件中焊点承受较大的应力应变,且远离中心的外侧焊点具有比内侧焊点更大的应力应变.IMC的存在极大的降低了焊点的可靠性.界面分层最先发生在最外侧的IMC/焊点界面的两端,随着热循环次数的增加,分层逐渐沿着界面两端向里扩展.在热循环的前几个阶段,各个界面的最大损伤值增大较快,随着热循环的继续加载,界面最大损伤值逐渐趋于稳定.整个过程中四号焊点界面的损伤值始终最大.In this paper,the influence of intermetallic compounds （IMC）,which was produced between the interface of SnAgCu solder and copper in the process of encapsulation, on the plastic ball grid array （PBGA） reliability was studied. The cohesive zone model （CZM） was adopted to model the interface de- laminating between solder and IMC under thermal cycling. The finite element simulation results showed： （1） the solders of electronic packages had the higher stress and strain in the thermal cycling; （2） IMC greatly reduced the reliability of solder; （3） delamination occurred firstly at the interface between IMC and the outside solder,then extended gradually toward the interior with the increase of thermal cycles; （4） in the early stages of the thermal cycles, the maximum damage on each interface increased quickly, however, with the increase of cycles,the damage tended to be stable gradually.

关 键 词：PBGA 焊点 金属间化合物 内聚力模型 界面脱层开裂 

分 类 号：TN405[电子电信—微电子学与固体电子学]