Moisture induced package cracking in plastic encapsulated surface mount components during solder reflow process

The process compatibility and potential component reliability problems associated with surface-mount technology are investigated. Major reliability concerns observed during qualification of vendors´ surface mount ICs are reported. Moisture-induced package cracking and its implication for the corrosion resistance of the package are discussed. The application of acoustic microscopy techniques such as scanning laser acoustic microscopy (SLAM) and C-mode scanning acoustic microscopy (C-SAM) for examining internal package cracking is described. The concept of threshold (safe) moisture level in a surface-mount package and the proper procedures for determining it are discussed