Comprehensive Die Strengths Comparisons for Glass Using Different Singulation Methods for Advanced Packaging Glass-Core Substrates

Failures on glass-core substrates for advanced packaging upon dicing, called SeWaRe, have been observed in recent years. In order to alleviate concerns for the industry, first the authors validated the integrity of glass as the main constituent in laminated packaging substrates. 3-point bending based die strength measurements on bare borosilicate glass after dicing were performed using 200mm sized glass wafers of different thicknesses dicing into different die sizes, 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 simulations concluded that the driving force for SeWaRe failures are the severely high energy release rate when glass core is diced with dielectric layers on both sides fully extended to the die edges. Using samples with ABF laminated on both side of glass core, the authors then empirically confirmed that as long as a die edge geometry, where the dielectric layers are pulled back, exists, SeWaRe failures can be eliminated.