Comprehensive Die Strengths Comparisions for Glass-Core Advanced Packaging Substrates using Different Singulation Methods - Dicing-Induced SeWaRe Failures Revisited Ten Years Later-

Near Mode- I fracture failures upon dicing on glass-core substrates for advanced packages, called SeWaRe, have been observed in recent years. In order to alleviate concerns from the industry, the authors validated the integrity of glass as the main constituent in laminated packaging substrates post-dicing. First, using 200mm bare borosilicate glass wafers, 3-point bending die strength measurements were performed after dicing at different thicknesses, into different die sizes, and using an array of singulation processes - both blade- and laser-based. When comparing across different dicing techniques, there are no correlations of die strengths to either (i) die edge chipping sizes, or (ii) sidewall roughness, Ra. Instead, the microstructural Stress Concentrator Factors of different dicing methods seem to be strong functions of dicing recipe parameters. Overall, any dicing method seems to be able to produce strong glass dies. Second, previous FEM simulations concluded that the driving force for Se WaRe failures are the severely high energy release rates, when glass core is diced with laminated dielectric layers on both sides fully extended to the die edges. The authors empirically confirmed that as long as the die edge geometry is such that the dielectric layers like ABF are pulled back from the edges, Se WaRe failures can be eliminated. Lastly, bare glass die strengths were compared to those of glass core only with laminated dielectric layers on both sides. Two different types of lamination materials were evaluated. Both cases confirmed that glass substrates with laminations are much stronger than bare glass dies. Furthermore, different techniques for creating the die edge pull-back geometries resulted in different die strengths. Therefore, a BKM dicing process for highest dies strengths has been established.