Design of robust packages by deliberate release of elastic energy to avoid interfacial crack propagation

Thermo-mechanical stress caused by the mismatch of coefficients of thermal expansion (CTE) and temperature changes remain a major concern for the reliability of semiconductor components. Over the last decade a lot of effort was spent to find solutions for avoiding delamination in packages by increasing adhesion at critical package interfaces. Cohesive zone element simulation allows the prediction of delamination behaviour and locating critical areas prone to unstable crack propagation. Exposed pad packages demand a more sophisticated method to detect cracks and delamination at the side wall of lead frames. In order to fulfil the requirements for future exposed pad packages for automotive applications, a simulation based approach is necessary to quantify the adhesion strength that is required to avoid delamination at critical interfaces.