Assembly reliability of Ball Grid Array and chip scale packages for high reliability applications

Abstract

Different aspects of advanced surface mount package technology have been investigated for aerospace applications. Three key areas included the assembly reliability of conventional Surface Mount, Ball Grid Arrays (BGAs), and Chip Scale Packages. Reliability of BGAs was assessed as part of a consortium effort led by the Jet Propulsion Laboratory. Nearly 200 test vehicles, each with four packages, were assembled and tested using an experiment design. The most critical variables incorporated in the experiment were package type, board material, surface finish, solder volume, and environmental conditions. The BGA test vehicles were subjected to thermal environments representative of aerospace applications. The test vehicles were monitored continuously to detect electrical failure and their failure mechanisms were characterized. A Microtype BGA consortium with industry-wide support was also organized to address technical issues regarding the interplay of package type, I/O counts, PWB (Printed Wiring Board) materials, and manufacturing variables on quality and reliability of board level assembly. This paper presents the most current thermal cycling test results (>4000 cycles) for ceramic and plastic BGA packages as well as their failure mechanisms. The board level reliability of CSP assembly will also be reviewed and projected for a specific environmental condition.