具有周边硅通孔的晶圆级芯片封装有限元分析

针对外围分布着硅通孔的晶圆级芯片封装结构,利用有限元分析软件ANSYS建立全局模型与次模型,在温度循环试验规范条件下将封装体与硅通孔结构分开进行仿真与探讨。了解模型受到温度载荷所产生的热力学行为。研究发现封装体在经历温度循环试验后所产生的位移呈现圆形对称分布,结构在高温时向外翘曲,在低温时向内弯曲;重布线层在与锡球交界处会产生明显的应力集中。硅通孔结构中铜垫片越接近开孔所受应力越大;硅通孔结构的重布线层部分,应力集中在转角处以及靠近钝化保护层交界处。

Finite Element Analysis of WLCSP with Periphery TSV

Aiming at the wafer level chip scale packaging(WLCSP)with un-order through silicon via(TSV)structure around the periphery of the package in un-symmetric manner,a full global model and a sub-model are established by ANSYS finite element analysis software.The package and TSV structure are simulated separately under the condition of temperature cycling test(TCT)specification.The thermodynamic behavior of the WLCSP structure under temperature load is studied.It shows that the displacement of the package presents a circular symmetrical distribution during temperature cycling test.The structure will warp outward at high temperature and bend inward at low temperature.The stress concentration occurs at the junction between the redistribution layer and the solder ball.The closer the copper gasket is to the hole in the TSV structure,the greater stress it will suffer.In the redistribution layer of the TSV structure,the stress concentrates at the corner and near the junction of passivation layer.