Impact of FEM Simulation on Reliability Improvement of Packaging

摘要

An important role of packages is the protection of the chip to environmentla influences like moisture, pollutants and other chemicla active spacies. If the chip is exposed these influences for instance corrosion is resulting and it may come to early failures. The reliability of the package is affected by thermo-mechanical stress. Due to this, an essential aspect of the package design is the careful combination of materials to avoid mechanical stress and to improve the thermal resistance of the package, whcih is significant for example in power or automotive applications. For a reduction of the mechanicla stress, a good heat conductivity into the ambient and by this a small thermal resistance of the package should be aspired. Finite element analysis(FEM) can give a fast and reliable solution to investigate the influence of mechanical stress as well as the thermal behaviour of the package, depending on the material properties and on the package geometry. For the finite element analysis special boundary conditions like convection and radiation and the influence of the board have to be taken into account.