Failure analysis and case study of plastic encapsulated microelectronics

For the package size, weight and cost advantages, plastic encapsulated techniques have been widely used in the packaging industry. However, due to the inherent seal problem of the plastic materials itself and the mismatched coefficient of thermal expansion (CTE) between the epoxy moulding materials and the various interfaces, many reliability problems are worth of serious consideration. In this paper, common failure modes such as bonding pad corrosion, popcorning effect, solder bumps bridging, metallization damage are initially summarized and so are the relevant failure mechanisms. Thenfour typical cases of failure analysis were provided to explain the mechanisms. Finally, some measures are introduced to minimize such failures.