Resistor-capacitor approach for modelling of temperature and humidity response inside electronic enclosures

Moisture is an important factor to reliability, functionality and durability of electronic devices. Nowadays, modelling tools have become an integral part of electronics design, because they are less expensive for searching the optimal design of moisture control. CFD and FEM are very time consuming due to their computational effort, therefore it is desirable to have a method such as well-known Resistor-Capacitor (RC) approach which is faster and has less spatial resolution.

The paper concerns the development of an in-house code using the RC approach for simulating coupled heat and moisture transport inside electronic enclosure under non-isothermal conditions. Thereafter, the simulations results were compared with corresponding experiments in order to validate the developed code.

Based on comparison with experiments, a new configuration RC model was developed for a more accurate humidity prediction. In general new RC model had the adsorption and desorption mechanisms included as a lumped capacitance for describing the surface of a wall on its both sides. Such modification improved the agreement with experiments.