Glass to Metal Sealing

Glass-metal sealing creates a hermetic seal and an electrical path. It withstands high temperatures. Glasses of special composition are needed for sealability.

Glass to metal sealing technology has been around for decades and is still an important technology for many microelectronics products. Glass to metal sealing is used on devices ranging from glass diodes to hermetic electrical feedthroughs for vacuum packages. Ultimately glass to metal sealing is used to create a hermetic seal between two environments while allowing an electrical conductance path. The subsequent seal can withstand higher environmental and operational temperature than many other sealing technologies. To ensure “sealability” (which means the thermal contractions of the two sealing components match each other below the transformation temperature of the glass), glasses of special composition are required.