倒装芯片封装中非牛顿流体下填充的数值仿真  

Numerical Simulation of Non-Newtonian Underfill in Flip-Chip Packaging

作　　者：姚兴军[1] 张关华[1] 王正东[1] 章文俊 周鑫延[1] 

机构地区：[1]华东理工大学机械与动力工程学院,上海200237 [2]萨斯喀彻温大学机械工程系

出　　处：《半导体技术》2013年第1期69-73,78,共6页Semiconductor Technology

摘　　要：倒装芯片封装中的下填充工艺可以有效地提高封装连接的可靠性,因而得到了广泛应用。含有硅填料的环氧树脂是常用的下填充胶料,在下填充流动过程中表现出明显的非牛顿流体特性。利用Fluent软件对具有非牛顿流体特性胶料的下填充过程进行了三维数值模拟。采用流体体积比函数(VOF)对流动前沿界面进行追踪,再用连续表面张力(CSF)模型来计算下填充流动的毛细驱动力,并用幂函数本构方程来体现下填充胶料的非牛顿流体特性。通过数值模拟,获得了下填充流动前沿位置随时间变化的数据,这些数据与实验结果有较好的吻合度。该数值方法可较好地预测具有非牛顿流体性质胶料的下填充过程。Underfill technology is often used in flip-chip packaging as it can improve the reliability of the interconnect systems effectively. Epoxy containing silica fillers is the most common encapsulant, and it exhibits obvious non-Newtonian behavior in the underfill flow. The 3D simulation of the filling process was operated using Fluent software. Volume of fluid （VOF） technique was applied to track the flow front, and the continuum surface force （CSF） model was used to describe the capillary force when the power-law type equation was employed to model the viscosity of the underfill encapsulant. The numerical results show the variation of flow front position with respect to time agrees well with the previous experimental data. This simulation provides a reasonable flow front prediction for underfill flow of encapsulant with non-Newtonian feature.

关 键 词：倒装芯片 下填充 非牛顿流体 流体体积比函数 连续表面张力模型 

分 类 号：TN305.94[电子电信—物理电子学]