Effect of type of foil and blade type to backside chipping in wafer level packages

This paper is to discuss the factors which contribute to the wafer backside chipping after sawing. The factors consider in this study are: Factor 1: Foil properties (adhesiveness and hardness) Factor 2: Saw blade properties (diamond grit size and concentration) Factor 3: Die size after sawing. The influences of these three factors have been discussed base on the study results. Result show that the smaller diamond grit size, stronger foils adhesiveness, the backside chipping able to be reduced. While by reducing the grit size and the diamond concentration of the blade, hardness of the foil become more important than adhesion of the foil.