Environmental Stress
Environmental test profiles of this type expose electronic assemblies to alternating high and low humidity levels at controlled temperatures. By simulating real-world shifts, atmospheric humidity cycling forces moisture into and out of protective seals. The process stops applying when the equipment resides in permanently dry or hermetically sealed chambers.
Moisture ingress can cause catastrophic electrical shorting. High stress environments accelerate the physical breakdown of insulation material.
Testing Chamber
Specialized environmental chambers generate the necessary temperature ramping and relative humidity percentages. These automated chambers use deionized water to prevent sensor contamination during prolonged exposure. Programmed schedules transition between saturation levels.
Air circulation must remain uniform across all test pieces.
Failure Mode
Delamination of conformal coatings and corrosion of internal copper traces occur when moisture becomes trapped. During rapid temperature drops, condensation forms on exposed surfaces. This liquid water bridges conductors.
Current leakage increases as a direct consequence of this bridging action.
Verification Cycle
Verification occurs by measuring insulation resistance at scheduled points throughout the test sequence. Technicians perform these measurements to verify the sealing integrity of the enclosure. The test standard defines the acceptable loss of performance.
Any drop below the designated threshold represents a failure.
