Non-Destructive Fault Localization in Fan Out Wafer Level Packages Using Electro Optical Terahertz Pulse Reflectometry

Here, we demonstrate how electro optical terahertz pulse refiectometry (EOTPR), a time-domain refiectometry technique that utilizes terahertz frequency electrical pulses to identify device faults, can be used to quickly and non-destructively isolate faults in advanced fan-out wafer level (FOWL) packages. We present a case study to show how EOTPR can accurately locate faults in the densely spaced redistribution layers (RDLs) of the package.