Quantum Diamond Microscopy for Non-Destructive Failure Analysis of an Integrated Fan-Out Package-on-Package iPhone Chip

Abstract: The increasing complexity of advanced semiconductor packages, driven by chiplet architectures and 2.5D/3D integration, challenges conventional failure localization methods such as lock-in thermography (LIT) and complicates current Failure Analysis (FA) workflows. Dense redistribution layers and buried interconnects limit the ability of established techniques to understand failure mechanisms non-destructively. In this work, we validate quantum diamond microscopy (QDM) based on nitrogen-vacancy (NV) centers in diamond as a non-destructive localization method through magnetic current path imaging at the package level. Using commercial Integrated Fan-Out Package-on- Package (InFO-PoP) devices from iPhones, we showcase a complete FA workflow that includes QDM to localize a short-type failure at an Integrated Passive Device (IPD) at the package backside. We showcase that the QDM results provide invaluable information on top of conventional techniques and can significantly enhance root-cause identification in package-level FA workflows. This work demonstrates the potential of QDM for broader integration into semiconductor chip and package analysis workflows.