Improvement of sensitivity of ultrasonic beam induced resistance change (SOBIRCH) method with ultrasound resonance in mold resin

In some cases of failure analysis of semiconductor devices, package state analysis without mold decapsulation is required. The ultrasonic beam induced resistance change (SOBIRCH) method has been proposed to carry out the analysis without decapsulation. In the previous research, it was suggested by numerical simulation that ultrasonic resonance in mold resin improves the sensitivity of the SOBIRCH. In this report, the sensitivity improvement with ultrasound resonance was verified experimentally.