Patrick McCluskey and Michael Pecht
University of Maryland
U.S. Army Research Labs
Intel Corporation, Beaverton, OR
The decreased availability of MIL-SPEC components is forcing designers of low volume complex electronic systems, such as avionics and defense electronics, to consider the use of commercial off-the-shelf plastic encapsulated microcircuits (COTS PEMs). Traditionally, designers of these long-life, high reliability systems have been reluctant to use COTS PEMs because of concerns related to their capability to survive in harsh environments over long periods of continuous or intermittent operation. Many commercial insertion studies in the last several years have now conclusively demonstrated that PEMs made using best commercial materials, processes, and quality techniques will permit devices to perform reliably in the most severe environments. However, only recently have studies focused on the reliability of PEMs in that subset of applications requiring short time operation after long periods of unpowered storage (10 to 20 years).
This paper presents the results of five critical commercial insertion studies focusing on long term storage reliability. These studies include analysis of PEMs, hermetic microcircuits, and assemblies stored for up to 28 years in various storage locations around the world. Regardless of the storage conditions, commercial grade PEMs, without screening or incoming inspection, survived assembly and extended storage, even though, in some cases, degradation was observed on the boards.
Members can get more information on this topic here.
© IEEE. Personal use of
this material is permitted. However, permission to reprint/republish
this material for advertising or promotional purposes or for creating
new collective works for resale or redistribution to servers or lists,
or to reuse any copyrighted component of this work in other works
must be obtained from the IEEE.