Advanced 3D failure characterization in multi-layered PCBs

The non-destructive inspection of printed circuit boards (PCBs) represents an issue of constant importance in microelectronics. In this study, the detection of delaminations in modern PCBs by scanning acoustic microscopy (SAM) is described. It is shown that, even though the acoustic analysis is complicated due to the multi-layered build-up, delamination/delaminations can be located within the PCB by (1) utilizing the resulting curvatures of the layers for the detection, (2) analysing the generated SAM 2D data in combination with novel 3D data and (3) using Elastic Finite Integration Technique (EFIT) based simulations. Complementary destructive physical cross-sectioning corroborates the obtained results.