Underfill Injection Molding in Flip-Chip Packaging with Different Bumps Array Arrangements
The injection molding IC packaging process involves chip packaging and encapsulation techniques comprising mainly of cavity-filling and curing processes. In this paper, the complex 3D geometries and flow behaviors are simplified and modeled by a 2.5D thin-shell simulation. Important aspects of the cavity-filling process include the choosing of bumps array types, the cavity geometry, the injection process, the packing pressure, and the process temperature. The current investigation considers the filling and curing in the different bumps array types. It is shown that the applicable array arrangement provides improved filling results on the flow front, curing, shear strain-rate and velocity vector distributions. These results show the better choice using the geometry parameters in the bumps array arrangement is to consider the performances of the local and global penetrations together.
Sheng-Jye Hwang and Sen-Yung Lee
C. M. Lin et al., "Underfill Injection Molding in Flip-Chip Packaging with Different Bumps Array Arrangements", Materials Science Forum, Vol. 594, pp. 163-168, 2008