Tuning of through glass via (TGV) shapes for glass-core substrates

Glass-core substrates are emerging as next generation packaging base material offering significant benefits compared to traditional organic-based substrates. The possibility to tune modulus and to change the CTE (coefficient of thermal expansion) of the glass, matching that of silicon, plays a crucial role in minimizing stress induced by CTE mismatches, particularly for large form factors [1] . Additionally, glass is a comparatively cheap material available in various sizes and thicknesses. Another serious advantage of glass is the increased dimensional stability enabling downscaling, a critical feature supporting the shrinking of electronic devices [2] . The high-temperature resilience of glass substrates paves the way for advanced integrated power delivery systems, critical in high-power electronics. Low electrical loss enhances high-speed signaling, crucial for high-frequency applications [3] , [4] . The ability to realize a higher density of through vias, potentially tenfold that of organic substrates, ensures complex circuit designs supporting improving routing and signaling [5] .