Surface Electro-Static Discharge or mechanical damage: Solving the mystery of metal-to-metal shorts using an innovative failure analysis approach

This paper introduces a new failure analysis procedure to distinguish Surface Electro-Static Discharge (ESD) from mechanically induced metal-to-metal shorts. The procedure utilizes two common techniques, Transmission Electron Microscopy (TEM) material analysis and Focused Ion Beam (FIB) cross sectioning. TEM analysis of the failure mechanism enables the material structure to be studied in order to distinguish the thermal from mechanical processes. Once a mechanical process has been confirmed, the formation of the failure mechanism is imaged through a new methodology for package analysis by means of backside cross-section using the Dual Beam FIB to show the molding compound interaction with the die surface for the first time.