Reliability and failure analyses of thermally cycled ball grid array assemblies

Reliability of ball grid arrays (BGAs) was assessed as part of a consortium effort led by the Jet Propulsion Laboratory. Nearly 200 test vehicles, eac h with four packages, were assembled and tested using an experiment design, The most critical variables incorporated in for the experiment were packag e types, ceramic and plastic; board materials, FR-4 and polyimide; surface finishes, OSP, HASL, and Ni/Au; solder volumes, low standard, and high; and environmental conditions. Thermal cycling test results to 3000 cycles for ceramic packages with 625 i nputs/outputs (I/Os) and depopulated full array plastic packages with 313 I /Os were presented in a previous paper [1], This paper will present the mos t current thermal cycling test results (>6000 cycles) for plastic OMPAC and SuperBGA packages with 352 I/Os and 560 I/Os, Failure mechanisms detected by electrical continuity interruptions as well as optical and scanning elec tron microscopy results will also be compared for ceramic and plastic packa ge assemblies.