Failure Analysis Based on Vehicle-Grade Transient Voltage Suppression Diodes

Electrostatic discharge and electrical overstress are commonly encountered challenges in the utilization of electronic components. These occurrences are particularly detrimental in the manufacturing, packaging, testing, and operational settings of integrated circuits. Within the automotive sector, the vehicle-grade transient voltage suppressor (TVS) stands as a pivotal protective measure against electrostatic discharge and electrical overstress, safeguarding electronic devices across diverse automobile modules. The comprehensive understanding and meticulous analysis of the failure mechanisms of the vehicle-grade TVS are of utmost importance for ensuring its reliable performance in this domain. Therefore, in accordance with established failure analysis and detection procedures, a thorough investigation was conducted into the failure of vehicle-grade TVS devices during the temperature cycle test. Microscopic inspections revealed the presence of cracks in the device's shell, while subsequent experiments further exposed delamination and solder leakage issues. Upon further examination, including sampling, grinding, and polishing of the device, it was discovered that internal chip cracking had occurred due to the popcorn effect. Utilizing advanced techniques such as electron microscope scanning and energy spectrum analysis, it was confirmed that dendrites formed within the solder and adhered to the chip surface, a phenomenon attributed to electromigration. Internal delamination, chip fragmentation, and dendrite formation were identified as the primary factors contributing to the device's failure. This comprehensive study contributes to system-level failure analysis and detection efforts for vehicle-grade TVS devices. It also provides valuable insights for considerations related to environmental usage, the selection of plastic sealing materials, and the assessment of reliability.