Experimental study of humidity distribution inside electronic enclosure and effect of internal heating
Abstract
Corrosion reliability of electronic products is a key factor for electronics industry, and today there is a large demand for performance reliability in a wide range of temperature and humidity during day and night time periods. Corrosion failures are still a challenge due to the combined effects of temperature, humidity and corrosion accelerating species in the atmosphere. Moreover the surface region of printed circuit board assemblies is often contaminated by various aggressive chemical species.This study describes the overall effect of the exposure to severe climate conditions and internal heat cycles on the humidity and temperature profile inside typical electronic enclosures. Defined parameters include external temperature and humidity conditions, temperature and time of the internal heat cycle, thermal mass, and ports/openings size. The effect of the internal humidity on electronic reliability has been tested by measuring the leakage current on inter-digitated test comb patterns which are pre-contaminated with sodium chloride and placed inside the enclosure.Results showed that exposure to cycling temperature leads to a significant change of internal water vapour concentration, where the maximum value was function of the opening size and the presence of thermal mass inside the enclosure. A pumping effect was observed and the increase of the level of absolute humidity at each cycle lead to condensation, corresponding to a sudden increase in leakage current of the test patterns pre-contaminated with sodium chloride. The changes of internal temperature and humidity can lead to water condensation and evaporation cycles which can cause electrical failures
Info
Conference Paper, 2016
UN SDG Classification
DK Main Research Area
Science/Technology
