Modelling Thermally-Induced Mechanical Faults in Power Integrated Circuits Assemblies

The structure of a Double Diffused Metal-Oxide-Semiconductor (DMOS) device is complex and consists of multiple routing metallization layers interconnected through vias embedded in Silico Dioxide (SiO ₂ ). The predominant failure mechanisms that occur after a large number (e.g. 10 ⁶ ) of active cycles are the crack formation between two adjacent signal metal lines and/or delamination of power metal plates from the SiO ₂ layer. Numerical simulation of power IC's based on finite element analysis is one of the most used simulation tools for the defect risk assessment. A novel subdivision method combined with the homogenization and nonconformal mesh of computational structure is applied to the model to efficiently simulate the complex IC structures. Results are assessed on a commonly DMOS layout substructure.