ABF塑封基板叠孔的高可靠结构设计  

Highly Reliable Structural Design of Stacked Holes for ABF Plastic Package Substrates

作　　者：葛一铭 谢爽 吕晓瑞 刘建松 孔令松 GE Yiming;XIE Shuang;LYU Xiaorui;LIU Jiansong;KONG Lingsong(Beijing Microelectronics Technology Institute,Beijing 100076,China)

机构地区：[1]北京微电子技术研究所,北京100076

出　　处：《电子与封装》2024年第3期56-63,共8页Electronics & Packaging

摘　　要：在塑封倒装焊结构中,有芯基板的布线过孔结构在温度循环载荷下的疲劳开裂是影响其可靠性的重要因素。为提升军用增强型有芯基板的设计可靠性,建立了基于Ansys有限元分析软件的塑封基板叠孔疲劳寿命仿真流程,通过子模型分析方法,预测了叠孔应力集中点的疲劳寿命,研究了叠孔位置、叠孔层数、芯层厚度、布线长度等因素对温度循环可靠性的影响。结果表明,铜布线结构最大应力应变点出现在叠孔底端与布线层连接处,这与实际生产中封装样品的失效模式一致,疲劳寿命仿真结果与实验结果相吻合。芯片对角位置叠孔的疲劳寿命比中心位置叠孔下降约36%。与2层叠孔相比,4层叠孔的疲劳寿命下降约55.6%。芯层厚度每增长0.4 mm,叠孔寿命相较于芯层厚度增长前分别下降约22.1%和27.5%。相较于370μm布线结构中的叠孔,5μm布线结构中叠孔的疲劳寿命下降约22.4%。Fatigue cracking of the wiring through-hole structure of a cored substrate under temperature cyclic loading is an important factor affecting the reliability of the flip chip structure of plastic package.In order to improve the design reliability of military enhanced cored substrates,a fatigue life simulation process of the stacked holes of the plastic package substrates based on Ansys finite element analysis software is established,and the fatigue life of the stress concentration points of the stacked holes is predicted by the method of sub-model analysis,and the influences of factors such as the location of the stacked holes,the number of the stacked holes,the thickness of the core layer,and the length of the wiring on the reliability of the temperature cycling are investigated.The results show that the maximum stress-strain point of the copper wiring structure occurs at the connection between the bottom end of the stacked holes and the wiring layer,which is consistent with the failure mode of the package samples in the actual production,and the fatigue life simulation results are consistent with the experimental results.The fatigue life of the stacked holes in the diagonal position of the chip decreases by about 36%compared to the stacked holes in the center position.The fatigue life of 4-layer stacked holes decreases by about 55.6%compared to 2-layer stacked holes.For every 0.4 mm increase in core layer thickness,the fatigue life decreases by about 22.1%and 27.5%respectively,compared to that before the increase in core layer thickness.Compared to the stacked holes in the 370μm wiring structure,the fatigue life of the stacked holes in the 5μm wiring structure decreases by about 22.4%.

关 键 词：ABF基板 塑料封装 疲劳寿命 有限元分析 

分 类 号：TN305.94[电子电信—物理电子学]