Process for fabricating ball grid array package for enhanced stress tolerance

摘要

The thermomechanical stress sensitivity of ball grid array (BGA) solder connections is significantly reduced, when the solder connections solidify in column-like contours after the reflow process—a result achieved by using the solder material in tapered openings of a thick sheet-like elastic polymer adhered to the BGA substrate and selected for its characteristics of non-wettability to solder and volumetric shrinkage greater than solder.