Novel end-point solution for improvement in die strength and yields with plasma dicing after grind in volume production

Abstract

A key driving force within the consumer electronics industry has always been to fit more functionality into a smaller area, and with the evolution of mobile communications and wearable devices, there are no signs of this requirement diminishing. This drives the need for smaller and thinner die for integration into smaller and thinner packages, and yet these chips need to be robust enough to withstand relatively harsh operating conditions in everyday use. While conventional mechanical blade dicing will continue to be the most cost-effective method to singulate die in the majority of cases, there are a growing number of applications where plasma dicing can either offer economic or die quality benefits when compared to blade dicing or other alternatives like LASER dicing. In some cases, plasma dicing even enables die singulation which is technically impossible using conventional methods, particularly where wafer thickness is approaching ∼20μm. Recent product teardown reports [1] have shown evidence of plasma dicing in a leading smartphone, and while plasma dicing after grind is at the early stages of adoption for volume production, the trend toward thinner, smaller die distinguishes it as an increasingly attractive alternative to mechanical saw or laser solutions. This paper gives a brief introduction to the potential benefits of plasma dicing and the design challenges of integrating this relatively new technology into existing volume production schemes, including CoO analysis comparing blade, laser and plasma dicing for different die sizes, and then focus on how end-point process control is essential to ensure die strength and device yields.