A Methodology to Integrate Thermo-Mechanical Reliability Predictions into Co-design of Flip-Chip-On-Lead Devices

Flip-Chip-On-Lead (FCOL) interconnect based plastic packages are increasingly used in power semiconductor devices. The technology offers high design flexibility from a bump size, bump pattern, and leadframe layout point of view. Design flexibility allows the device to meet functionality, electrical and thermal performance requirements through co-design. Given the complexity of mechanical reliability, and sensitivity to design features, lack of a robust approach to assess mechanical reliability risks can cause delays in development, qualification, and ramp. This study presents a methodology to develop co-design capability for mechanical failure modes. The approach utilizes thermo-mechanical simulations correlated with empirical data to develop failure thresholds. Devices designed within the thresholds are expected to be robust through qualification and ramp.