Warpage of Fan-Out Panel Level Packaging – Experimental and Numerical Study of Geometry and Process Influence

Abstract

In order to reduce waste and cost, the trend in Fan-Out Packaging is the move to rectangular panels instead of circular wafers [1]. These panels can be made in larger formats and better utilize the space due to the rectangular shape. However, with the larger format, warpage of the panels increases and remains a challenge in Fan-Out Panel Level Packaging (FOPLP) production. Warpage occurs mainly due to the multitude of materials that undergo multiple production steps at different temperatures, which leave residual stresses induced by mismatch of thermal strains and strains due to chemical processes (e.g. cure shrinkage). These superimposed effects and the complex material behaviour still make it challenging to predict warpage numerically and control warpage during production [2], [3]. In this work, warpage of nine different variants of a 300 × 300 mm2 panels with dummy dies have been investigated experimentally and numerically. It has been shown that the numerical model can replicate warpage of the panels and the potential for numerically supported warpage adjust steps in the fabrication of the panels has been demonstrated.