Micro & nanoDAC - A powerful technique for nondestructive microcrack evaluation

Recent advances in microelectronics and electronic packaging technology have led to a strong need in strain and stress analysis on micro and nano scale as well. Smallest cracks, delaminations and defects are a concern and can initiate defect propagation and can also cause failure of whole components. Crack detection and evaluation for crack lengths of very small microcracks are required. The authors present an approach to deformation measurement based on local correlation analysis on captured micrographs. Incremental displacement and strain fields are extracted from SEM and AFM images picked up for different object loading states. The application of the method is demonstrated by investigations of electronic packages. Fracture mechanics has been applied to combine the experimental results with advanced fracture and reliability concepts. Displacement fields in the immediate vicinity of micro and nano crack tips and crack opening displacements as small as some nanometers h ave been measured. They are used to determine fracture parameters. The results have also been used as input parameters in parametrized finite element simulation.