Electroplating Uniformity Enhancement for High Performance Fan-Out Panel Level Packaging

Fan-out panel level packaging is a promising advanced packaging technology. It can easily achieve heterogenous integration by merging functional chips into a single module. However, the electrical quality and mechanical stress balances become more challenge. In a package structure, Cu redistribution layer (RDL) not only offers an interconnection platform but also plays a key role in affecting electrical and mechanical performance of whole system. Ideally a uniform Cu trace will lead to a better reliability performance. But when process area become larger, especially in fan-out panel level packaging (FOPLP), it is difficult to improve RDL thickness uniformity within panel (WIP) by sustaining a uniform electric and fluidic distributions in a large electroplating (ECP) system. This study proposes and experiments an effective way to diminish the trace thickness variation by adding and modulating pattern design. Via this technology the thickness variation can be optimized by each product, and thus enlarging the utilization area of panels.