倒装芯片下填充流动二维化数值分析方法的应用

Application of Two-Dimensional Numerical Analysis Method of Underfill Flow in Flip-Chip

下填充流动是确保倒装芯片可靠性的重要封装工艺,其流场和流动过程具有明显的二维特征,通过降维得到的二维化数值分析新方法能高效地模拟下填充流动过程。针对一种焊球非均匀、非满布的典型倒装芯片,用该数值分析方法模拟了单边下填充流动的过程,并用实验对模拟结果进行了检验。实验采用了可视化的下填充流动装置,倒装芯片试样采用硅-玻璃键合(SOG)方法制作。将数值模拟结果与实验结果比较发现,无论是流动速度还是流动前沿的形态,两者均呈现出较高的吻合度。这表明:针对下填充流动的二维化数值分析方法兼具高效性和准确性,具有较高的应用价值。

Underfill flow is an important packaging process to ensure the reliability of flip-chip. The flow field and flow process have obvious two-dimensional characteristics. The new two-dimensional nu- merical analysis method from dimension reduction can efficiently simulate the underfilling process. A nu- merical simulation of a single edge underfill flow was presented for a typical flip-chip with non-uniform and non-overall arranged solder bumps. The simulation results were verified by experiments. A visualized underfill flow device was used in the experiment. The flip-chip samples were fabricated by silicon on glass （SOG） method. Numerical simulation results were compared with experiment results. The compa- ring results show that the flow velocity is highly indentical with the flow front shape. This shows that the two-dimensional numerical analysis method for the underfilling flow has high efficiency, accuracy and high practical value.