Gideon Analytical Laboratories received two failed AUIRF7648M2 MOSFETs. These are rather new on the market and specifically designed for the automotive industry. Typically, when a MOSFET fails, all terminals short. It is the failure analyst's job to discover how the MOSFET failed in the application by combining the schematics, clues found in the failure analysis, and clues found on the PCB to give a complete picture to help resolve the client's problem.
The AUIRF7648M2 has one of the lowest gate charges as well as the lowest on-state resistance in a SO-8 package. TheDirectFET package is compatible with existing layout geometries used in power applications, PCB assembly equipment, and vapor phase, infrared or convection soldering techniques when following IR's suggested manufacturing and process methods, see AN-1035. The design maximizes thermal cooling on both sides. The package is a platform coupled with the IR rugged silicon technology which improves performance in motor drive, high-frequency DC-DC and other heavy load applications on the ICE, HEV and EV platforms.
In addition to electrical testing, radiography is used to confirm physical failure within the package. Parts are removed from the PCB and decapsulated for further optical inspection. The parts were inspected for clues in the structure of the MOSFET. The majority of the die revealed a catastrophic body diode meltdown failure but the gate region reveals a clue in how the failure was initiated, by the excessive gate voltage. The gate voltage was too high in the application and burned through the oxide separating the gate from the source. Once this occurs, the source and drain will fail.
Gideon Analytical Laboratories, Inc. can solve many application problems. We just do not say EOS and on with business because your product is at stake, not just the component. Many companies have us do all their failure analysis because their clients never see the failures.