Low temperature sealing: Since it has a lower melting point than gold-tin solder, it can be joined and sealed at low temperatures.
Hetero-materials can be bonded (glass & ceramic): It can bond between heterogeneous materials because of lower Young’s modulus compared to gold-tin solder.
Hermetic under “ambient” atmosphere: It is less likely to oxidize than gold-tin solder. Oxygen sealing suppresses deterioration over time of LED or LD chips.
