Authors: Reza Ghaffarian, Ph.D. Company: Jet Propulsion Laboratory, California Institute of Technology Date Published: 9/17/2017
Abstract: This paper presents the reliability of fine pitch plastic ball grid arrays (FPBGAs) with 228 (0.5-pitch) or 432 balls (0.4- mm pitch) with either tin-lead or SAC305 balls as well as the reliability of a flip-chip ball grid array (FCBGA) with 1924 tin-lead balls and 1-mm pitch— all assembled with eutectic tin-lead solder onto printed circuit boards (PCBs). Surface finishes for PCBs were electroless nickel electroless palladium immersion gold (ENEPIG) and tin-lead hot air solder level (HASL). These assemblies were subject to 200 thermal shock cycles (TSC, –65°C to 150°C). The TSC test results presented include daisy-chain resistances, SEM/Xsection images, and dye and pry destructive failure analyses for HASL and ENEPIG surface finishes.