Thermal Drift Compensation Calibration for Sub-Millimetre Cavity Telemetry Systems
Sub-millimetre telemetry cavity accuracy requires compensating for steel expansion and polymer dielectric drift via real-time press-side calibration.
Hermetic Seal Integrity
Meaning
Gas tightness defines the ability of a joined or moulded assembly to prevent the passage of air, oxygen, vapour and moisture over a sustained period. Achieving hermetic seal integrity is mandatory for electronic housings and medical devices where internal components require protection from the environment. The quality of the seal depends on the resin choice, the bonding method and the surface finish of the mating parts.
Barrier Performance
Molecular diffusion can compromise the vacuum. Factors affecting hermetic seal integrity include the crystallinity of the plastic and the presence of micro voids at the weld line.
Joining Reliability
Ultrasonic welding or overmoulding techniques create the physical bond that must remain intact. Any contamination or grease on the sealing surface prevents the formation of a continuous molecular bridge, leading to hermetic seal integrity failure. Process variables such as melt temperature and hold pressure must be tightly controlled to ensure a perfect fusion.
Validation Method
Pressure decay testing or helium leak detection verifies that the assembly meets the required leakage rates. Maintaining hermetic seal integrity across a full production lot requires automated inspection systems. Environmental stress cracking or thermal cycling can degrade the seal over time, so accelerated aging tests are used for long term verification.