NONDESTRUCTIVE DETECTION OF DELAMINATIONS IN MULTILAYER CERAMIC CAPACITORS USING IMPROVED DIGITAL SPECKLE CORRELATION METHOD

The use of an improved digital speckle correlation method (DSCM) was d emonstrated for the in situ and nondestructive detection of delaminati ons in layered-structure microcomponents such as multilayer ceramic ca pacitors (MLCs) in surface-mount printed circuit board assemblies. The delaminations in MLCs that contributed to thermal displacements on th e MLC surface after electrical lending could be uniquely identified us ing the improved DSCM; with the help of a double-lens arrangement. The method was found to be very sensitive to tile thermal displacement of the MLS surface after electrical loading A resolution of better than 20 nm in surface deformation measurements has been achieved within 0.0 1 pixel resolutions. The delamination in a MLC, as obtained by this me thod, correlates well with destructive physical analyses performed on the respective samples. (C) 1997 John Wiley & Sons, Inc.