TSMC Expands Glass Substrate Supply Chain for CoWoS Packaging

TSMC is expanding its supply chain for glass substrates used in CoWoS packaging. Glass substrates offer better thermal performance than organic ones, which matters for high-end AI GPUs like NVIDIA’s Rubin and Blackwell.

Glass substrates outperform organic in key metrics

CoWoS is TSMC’s advanced packaging technology for stacking chips. The company’s Kevin Zhang said CoWoS will remain the mainstay packaging for advanced AI chips.

• Warpage improvement: 16% drop
• Thermal expansion improvement: 19% drop
• Resistance improvement: 27% drop
• Inductance improvement: 42% drop

Glass substrates show a 16% drop in warpage and a 19% drop in thermal expansion compared to organic substrates. They also improve resistance by 27% and inductance by 42%.

Despite these gains, mass production of glass substrates is still distant due to conductivity challenges. The timeline remains unknown.

Glass substrates mimic silicon’s thermal performance better than organic substrates, according to DigiTimes. This makes them suitable for next-generation AI hardware.