Critique of EIA SSB-1: guidelines for using plastic encapsulated microcircuits and semiconductors in military, aerospace, and other rugged applications

Abstract

Economics and availability concerns, together with internal directives, have provided a strong impetus for the military and aerospace electronics industries to use commercial plastic encapsulated microcircuits (PEMs) in their applications. To address concerns related to the reliability of commercial devices in these harsh environment applications, the G-12 Solid State Device Committee of the Government Electronics & Information Technology Association (GEIA) has developed guidelines for assessing the suitability of plastic encapsulated microcircuits and semiconductors for use in military, aerospace and other rugged applications. These guidelines were recently published in the Electronic Industries Alliance Engineering Bulletin. The concept of these guidelines is a step in the right direction, as they provide direction to industry on how to incorporate PEMs reliably. They provide an approach to assess the use of PEMs that correctly separates manufacturer quality and part reliability issues. Furthermore, the guidelines recognize that failure can occur by multiple failure mechanisms that are excited by many different environmental factors, not just temperature. However, the guidelines omit several critical elements from their evaluation plan that are present in other approaches, the reliability assessment does not directly account for component architecture in its calculations, and the approach uses constant failure rate statistics and parts count methodologies to evaluate system reliability. This last characteristic has caused some to indicate that the guidelines bear strong similarities to MIL-HDBK-217, which has been precluded from military use. This paper provides a critique of the SSB-1 Guidelines.