SUMMARY AND CONCLUSIONS

The thrust of this paper was to address the use of PEMs in military applications by reviewing their strengths and limitations relative to HSMs, comparing reliability data on the same microcircuit families manufactured in both package systems, describing the systematic approach for producing reliable PEMs, and outlining the conditions and best practices for achieving optimum use of PEMs in the system application. It was stated that within the reliable operating and storage envelope, PEMs are as reliable as HSMs, and therefore should be considered for the appropriate military applications. The key to successful use of PEMs is gained through matching the application conditions to the capability of PEMs. For some highly critical applications more characterization of PEM reliability is required to determine limitations and establish confidence, especially where radiation hardness and prolonged storage are requirements. However, PEMs have demonstrated acceptable reliability in a multitude of commercial/industrial applications for many years. Hence, there exists today a substantial amount of data and wealth of experience from which to support the use of PEMs by the military in similar applications. Finally, it is emphasized that procuring PEMs from a qualified supplier, one having extensive experience in both hermetic Military/Aerospace microcircuits and PEMs used in rugged environments, such as automotive, is as important as defining the envelope for reliable use.