Improved failure analysis in 3D electronic packages by MicroCT

As an example for interconnections in 3D integrated packages we inspected through mold vias (TMV) in a stacked mold embedded package recently presented by Braun et al. [1] by novel microfocus X-ray tomography (microCT). The resulting 3D images and slices visualize the coating of the laser drilled holes as well as fill grains in the molding compound at micron resolution, revealing coating defects. In the same sample, Microvias and BGA solder joints were imaged reproducing our previous results [2, 3, 4] yet on a higher level of integration. These interconnections were checked for misalignment and land wetting, respectively, identifying the typical defect signature.