Gas Absorption
Reactive chemical materials deposited inside sealed micro-electromechanical packaging cavities act as internal gas absorption structures in resonant and optical sensors. A vacuum cavity getter absorbs residual gases and outgassed molecules to maintain low internal pressure over component lifespans. Mass spectrometers measure residual gas concentrations inside test cavities during packaging qualification.
Getter operation halts once chemical saturation occurs across active surface sites.
Pressure Maintenance
Gas absorption occurs through chemical reactions between getter materials and outgassed species such as hydrogen, water vapor, and carbon monoxide. Non-evaporable getter materials bind gas molecules onto their porous matrix surfaces through irreversible chemical bonds. Residual gas analysis confirms pressure stability inside sealed device cavities under extended thermal stress.
Sorption rate testing evaluates gas pickup speed across various operating temperature levels. Saturation limit measurements define maximum outgassing volumes the getter can absorb before pressure rises.
Activation Process
Activation process heating breaks down surface oxide layers on getter materials, exposing reactive metallic surfaces to the sealed cavity environment. Thermal activation happens during wafer bonding or post-packaging baking cycles at controlled activation temperatures. Pyrometers monitor activation temperatures during wafer-level hermetic sealing operations.
Hermetic Lifespan
Hermetic lifespan of micro-machined resonators depends on the getter maintaining cavity pressures below target vacuum thresholds across decades of operational life. Loss of cavity vacuum increases mechanical damping, degrading quality factor and frequency stability in resonant MEMS components. Ring-down testing measures resonator quality factors over accelerated aging tests to verify vacuum longevity.
