Diagnosis of Hybrid Microelectronics using Transmission Acoustic Microscopy

This paper reports further progress we have made most recently on nondestructive diagnosis of hybrid microelectronic components using a 150 MHz transmission scanning acoustic microscope. Acoustic imaging of defects in production-line thin-film circuits, thick-film circuits, and multilayer chip capacitors was carried out. Contrary to the optical micrographs, the acoustic micrographs recorded show a high degree of contrast. A large differential acoustic attenuation (typically 30 db) and thus a high degree of nonuniformity was observed in the multilayer structures. For a thick-film resistor circuit the contrast in the acoustic micrograph was found to be a sensitive function of the resistance value. A simple method has also been established to determine both the defect location (in depth) and the defect type. We conclude that transmission acoustic microscopy is a highly useful and unique technique for failure analysis and quality control of hybrid microelectronics.