Non-destructive defect depth determination at fully packaged and stacked die devices using Lock-in Thermography

This paper will present a new non-destructive approach for the 3D localization of thermally active buried defects in single chip and stacked die architectures by use of Lock-in Thermography (LIT). The basic principles concerning the thermal wave propagation through different material layers and the resulting phase shift will be presented and discussed. Based on that, the LIT application for 3D defect localization will be evaluated at both fully packaged single chip and stacked die devices by comparing theoretical and experimental data.