hermeticity

Hermeticity refers to being airtight, meaning something is sealed in a way that prevents air or gas from entering or escaping. This is often achieved through a process called hermetic sealing.1

In industry, hermetic seals are crucial for maintaining specific environments within products. For example, in lightbulbs, metal wires are sealed through glass to keep an inert atmosphere inside. This concept is also applied in microelectronics, though hermeticity isn't always a requirement in that field.2

The success of a glass seal depends on factors like the glass's viscosity and temperature, how the materials expand and contract when cooled, and how well the molten glass wets and adheres to other components. A significant challenge is managing the thermal contraction mismatch between different materials, which can cause stress and fracture if not handled properly.2