An investigation of corrosion on integrated circuits via pressure-temperature-humidity-bias stressing

Pressure-temperature-humidity-bias (PTHB) is a consistent, repeatable stress capable of reducing qualification and evaluation cycle time through acceleration of moisture- and bias-induced failure mechanisms. Moreover, PTHB is more capable of finding susceptibility to corrosion than either THB or autoclave stressing, as illustrated by the historical monitor and precondition stressing results. Therefore, PTHB was implemented as the primary humidity stress in environmental stressing for device qualification and evaluation and for the monitor program. Specifically, bond-pad corrosion of a memory device was investigated. The mold compound was found to be inferior with respect to prevention of corrosion failures. All memory devices which were previously assembled with this mold compound have been converted to other mold compounds with lower extractable chloride content