PLASTIC ENCAPSULATED MICROCIRCUIT RELIABILITY PREDICITION - WHY

Reliability prediction models for microcircuits have been a function o f steady-state temperature. Failure rates generated From accelerated t emperature tests were extrapolated to predict system reliability at sy stem use temperatures. This is now known to be completely inaccurate. Attempts are now being made to predict the reliability of plastic enca psulated microcircuits (PEMs) based on accelerated temperature/humidit y testing. Failure rates generated due to corrosion failure mechanisms at these high stress levels are then extrapolated and used to predict system reliability at used temperature/humidity conditions. This pape r discusses the fallacy of this approach. A new concept for the assura nce of PEM corrosion resistance is proposed. It will be shown that tod ay's best commercial practice suppliers have already addressed the des ign, materials, and processing issues of molded packaged microcircuits , and corrosion is no longer a mechanism of concern to the user. (C) 1 998 Published by Elsevier Science Ltd. All rights reserved.