A new Method for Detection of Degradation in Die-Attach Materials by In-Situ Monitoring of Thermal Properties

There are many methods of detecting degradation in die-attach materials, e.g. SAM, X-ray, SEM etc. However, these methods are mainly used in offline testing and therefore involve a great amount of time and effort. The method, we present in this work, is non-destructive and enables in-situ monitoring of degradation. Voids or cracks cause the change of thermal behaviour in electronic packages, therefore the thermal behaviour is due to alter over lifetime. Therefore parametric simulation models have been developed, which enable the prediction of influence of delamination areas on transient thermal properties for different die attach materials. The simulation on example COB (chip-on-board) packages show, that an increase of delamination area causes a significant increase of transient thermal resistance. The computational results are validated with experimental measurements, which show a practical feasibility of the proposed method.