Design for the Package-Board Transition and Its Testability Design in the Fan-Out Wafer-Level Package

A fan-out wafer level package (FOWLP) with double-sided four redistribution layers (RDLs) and the mega pillars connecting front back RDLs has been proposed for millimeter-wave applications. well-matched package-board transition designed in this paper. The simulated insertion loss is about 0.82 dB at 79 GHz, return better than 10 from 72 GHz to 86 GHz. More importantly, two different measurement methods based on port reduction technique Thru-Reflect-Line (TRL) calibration have get S parameters of transition. Moreover, feasibility verified by simulation.