SAM Theory and Case Studies in Reliability and Counterfeit Detection

This article reviews the basic principles of scanning acoustic microscopy (SAM) and presents several case studies demonstrating its use in failure analysis and counterfeit detection. The FA case studies show how SAM is used to detect delamination, cracking, and manufacturing defects in ceramic chip capacitors and resistors, voids in a full-bridge rectifier, and a radiation-induced defect in a microprocessor. In cases involving counterfeit ICs, CSAM images reveal the presence of an abnormality on component packages, evidence of relabeling, and popcorn fractures indicative of the use of excessive heat and force to dislodge components from circuit board assemblies.