Accelerated preconditioning for stack die packages

Accelerated moisture preconditioning condition for JEDEC/IPC level 2 has been proposed in this paper, especially focusing on stack die packages. The condition has been determined based on the equivalent moisture absorption rate, local moisture concentration at the point of interest, and following moisture induced delamination failure. Shadow moiré technique has been implemented to ensure the equivalent moisture concentration at the accelerated and normal soak conditions, and the results have been verified by physical failure analysis. The proposed accelerated preconditioning condition is to be applied to dramatically shorten the package qualification test time, finally reduce time to market of new package products.