Solderability Acceleration
Accelerated degradation of board and component finishes under humid conditions simulates long-term warehouse storage before solderability testing. The practice of steam aging exposes test specimens to high-humidity steam to intentionally grow oxides and intermetallic layers. This exposure prepares the surfaces for standardized solderability tests, verifying that the components will remain solderable after extended periods in storage.
Aging Procedure
Technicians place the component leads or circuit boards in a closed chamber suspended directly above boiling deionized water. The temperature inside the chamber is maintained near the boiling point, exposing the specimens to a saturated steam environment for several hours. This high humidity and temperature accelerate the oxidation of copper and tin surfaces, mimicking up to a year of ambient storage.
After the steam cycle, the parts are dried and subjected to solderability evaluations like the dip and look or wetting balance test to check their remaining solderability.
Reliability Assurance
Inadequate solderability testing after storage simulation allows oxidized parts to enter the assembly line, causing poor solder joints. Steam aging acts as a reliable filter to identify finishes that degrade quickly before they are used in production. This test ensures that the stored components can still be safely assembled.
