CORWIL was recently approached by a medical customer who had developed a tiny wearable device that included a small bare die with innovative packaging. The product required a very small and strong die due to the customer’s very tight and unconventional package requirements. The die were on a 300mm wafer and had tight streets and low-k dialectrics.
Knowing that the backside and edge quality were key, the CORWIL team used Dice Before Grind (DBG) to reduce die breakage and chipping typically caused by the conventional method. DBG reverses the usual process of fully dicing the wafer after grinding. In DBG, the wafer is first trenched, or partial-cut, to a depth greater than the final target thickness. The wafer is then thinned to the final target resulting in die separation. After grind, the wafer goes to the in-line DBG Mounter, which mounts the wafer and gently peels off the protective grinding tape, completing the process.
Since the die are singulated at the final target thickness, wafer-level breakage is greatly reduced. Additionally, as a result of the die separation occurring during the grinding process, the backside chipping associated with thin-wafer dicing is kept to a minimum. DBG can also provide improved die strength depending on the application. For these reasons, DBG is an excellent process for processing wafers with high-quality backside requirements.
