Effect of Package Singulation Parameters on Dual Flat Non-leaded Package Delamination

Abstract

With the evolution of electronic and automotive field, the reliability requirement of package is getting stringent. The package is required to withstand the extreme conditions while maintaining good electrical performance. Interfacial delamination is one of the key factors that impacts the reliability of electronic package. When the delamination occurs between lead frame (LF) and epoxy molding compound (EMC), the moisture will ingress into the package and cause bond pad or wedge corrosion, which leads to electrical failure.To verify the robustness of Dual Flat Non-leaded (DFN) package, the effects of package singulation parameters on package delamination performance were investigated in this study, dicing blade types, saw method, spindle speed, feed speed, and cooling water flow rate. As the result shown, the blade with small grit size had better cutting quality and induced less stress than large grit size blade. Reducing the cutting stress was beneficial to improve the delamination performance. And the cutting methods also influenced on delamination performance. The chopper cut and normal cut method were used in the same type of package to compare the delamination performance. The results of C-SAM shown the normal cut had better delamination performance than chopper cut. In addition, the delamination performance deteriorated with increasing spindle speed, which was related to the adverse impact of blade at high spindle speed and heat generation of friction. And the feed rate also had a small effect on delamination. Besides, hundred-degree celsius temperature of heat will be generated during blade cutting, which will reduce the adhesion strength and cause the expand and contract of EMC and LF. Therefore, cooling the blade with high cooling water rate could help in delamination.In summary, the effect of package singulation on delamination defects was investigated in this paper. The delamination performance could be optimized by selecting suitable EMC, LF surface treatment & design, dicing blade, cutting method and singulation parameters.