Experimental study of transient heat transfer and temperature dynamics in the electronics enclosures

Uncontrolled local enclosure climate is one of the main causes of moisture related electronics failures such as electrochemical metal migration, corrosion, alternation of material properties and etc. To prevent these failures during lifespan of electronics systems, it is very important to understand well the mechanism of heat and mass transport into electronics and phase changes processes. The objective of the paper is to experimentally study the interaction of the transient heat and mass transfer and condensation-evaporation processes inside the electronics enclosures. The experiment with two empty enclosures placed inside the climatic chamber was carried out under oscillating ambient temperature. One enclosure is electronics aluminum enclosure, while the second - glass jar. The oscillating ambient temperature in the climatic chamber was used to simulate the heating and cooling regimes in order to cause condensation and evaporation processes inside the enclosures. The obtained results of relative humidity indicated the condensation on the wall surface and volumetric condensation inside the glass jar. In case of aluminum enclosure, the condensation occured only on the wall surface. The results were also analysed in terms of heat transfer based on the temperature measurements.