Study on the Assembly Technology of Die-First/Face-Down Type FO-PLP

Die shift and passive component drift were the issues of the fabrication of die-first face-down type FO-PLP. Those were investigated in the making process of 515 mm x 510 mm size test vehicle. It was found that there was a strong correlation between the die shift and the CTE of the panel after the temporary bonding adhesive film was removed and the pre-shift technique could reduce the die shift from 5 to less than 1μm. 70% of the fabricated packages were electrically connected. In addition, the cause of the passive component drift was made clear. Filler particle with a diameter larger than the gap between the component body and temporary adhesive entered the gap. The drift was greatly suppressed by using the molding compound with the smaller diameter filler and the temporary bonding film of higher adhesion.