Laser vs. Blade Dicing for Direct Bonded Heterogeneous Integration (DBHi) Si Bridge
The recently introduced Direct Bonded Heterogeneous Integration (DBHi) Si bridge technology has chips connected by a bridge housed inside a cavity or trench that is precisely machined in the chip-carrier laminate. The size, thickness, and placement centrality of the bridge are critical parameters that are necessary to prevent interference with the laminate substrate trench. In this study, we compared laser and saw dicing processes for the DBHi bridge technology. Different laser dicing recipes are developed and optimized. The laser and saw dicing process are compared for dimensional tolerances, edge quality, and die strength of the bridge chips. The die strength is affected by the edge defects on the top and bottom surfaces adjacent to the edges and is measured using a three-point bend fixture in a Universal Testing Machine (UTM). The laser dicing process is improved to equalize the die strength at both the surfaces as well as to achieve equal or higher die strength than blade dicing specifically for the thinner wafer thicknesses.