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 demonstrated for the in situ and nondestructive detection of delaminations in layered-structure microcomponents such as multilayer ceramic capacitors (MLCs) in surface-mount printed circuit board assemblies. The delaminations in MLCs that contributed to thermal displacements on the MLC surface after electrical loading could be uniquely identified using the improved DSCM, with the help of a double-lens arrangement. The method was found to be very sensitive to the thermal displacement of the MLS surface after electrical loading. A resolution of better than 20 nm in surface deformation measurements has been achieved within 0.01 pixel resolutions. The delamination in a MLC, as obtained by this method, correlates well with destructive physical analyses perfonned on the respective samples. © 1997 John Wiley & Sons, Inc.