Warpage analysis of high-density FC-PBGA device during package process

This paper focuses on the warpage of high-density FC- PBGA device during packaging process. The finite element analysis software ANSYS Workbench is used to simulate the warpage of high-density FC-PBGA device in the process of bump reflow, underfill, and heat-sink adhesion. At the same time, influence of various package parameters on the warpage is analyzed. The simulation results show that the device has the largest amount of warpage and warpage shows the shape of "cry face" after bump reflow. The underfill and heatsink adhesion have certain effect on improving warpage, while the chip size and chip thickness have great influence on warpage. With the increasing of chip thickness, the warpage decreases accordingly. The larger the chip size is, the more serious the warpage shows. In addition, different materials of substrate have relevant effect on the value of warpage. After the processes of bump reflow and underfill, the substrate with smaller CTE of Core material presents minimum warpage.