Silicate glass-to-glass hermetic bonding for encapsulation of next-generation optoelectronics: a review

Many of the new organic–inorganic hybrid materials for next generation optoelectronics have organic components sensitive to oxygen, moisture, and temperature, requiring hermetic encapsulation. Silicate glasses offer the wide optical transmission window needed for the optimal functioning of optoelectronic devices. The low oxygen and moisture permeability required for hermetic encapsulation can be achieved by glass-to-glass bonding with or without an intermediate layer. However, most of the traditional glass bonding techniques require processing at high temperatures not compatible with the new hybrid device materials that are temperature sensitive. In this work, we review the current state of knowledge in low-temperature (<150 °C) silicate glass-to-glass bonding. Hermeticity and bond strength testing methods are described and opportunities for hermetic electrical feedthroughs using silicate glass-to-metal bonding are discussed.