Lock-in Thermography judgment for short/leakage/high resistance defects in advanced Fan-Out packages

Fan-Out (FO) technologies are used for consumer electronic products generally due to the small and very thin features. Thinner packages are required by mobile industry and Fan-Out (FO) provides a good solution. The failure analysis (FA) case of devices with short defect is illustrated in this paper. The test vehicle is examined by curve tracer (I-V), optical inspection, IR inspection, Lock-in Thermography (LIT), 3D X-ray, then the destructive analysis such as Focus Ion Beam (FIB) and Scanning Electron Microscope (SEM) were used to confirm the defect mode. Physical failure analysis was performed on all cases and the results would be linked with the LIT fault isolation results. Through our studies, we can sum up the finding into the isolation judgment.