A reliability test on PBGA packaging through piezoresistive stress sensor

Plastic packaging is the mainstream on microelectronic packaging technology at present. As the continuous requirements for smaller but higher density products, failure and reliability issues on MEMS/MOEMS packaging because of the hygroscopic swelling mismatch stress become more and more serious. To this end, this paper presented the stress monitoring methodologies as well as the reliability tests on a typical PBGA (Plastic Ball-Grid-Array) packaging due to hygroscopic effects through the measurements with the piezoresistive stress sensors. It is concluded from the experiments in this work that the hygroscopic mismatch stress is significant for the packaging, and the Weibull reliability model is suitable for the PBGA packaging. In addition, piezoresistive sensors were proven useful for monitoring the stress on the chip inside the packaging structure.