Mechanics of Interfacial Delamination in IC Packages Undergoing Solder Reflow

When plastic packages undergo solder reflow after being subjected to moisture preconditioning, hygrothermal stresses are induced in the package. If these stresses are excessive popcorning failure will occur. It has been shown that popcorning failure is usually preceeded by delamination of either the pad/encapsulant interface or the die-attach-layer/pad interface. Fracture mechanics methodology has been shown to be a useful technique for analysing and predicting the onset of delamination. This paper describes an investigation on the mechanics of delamination at interfaces in typical plastic IC packages.