Overview of humidity driven reliability issues of electronics

Electronic control units, power modules, and consumer electronics are used today in a wide variety of varying climatic conditions. Varying external climatic conditions of temperature and humidity can cause an uncontrolled local climate inside the device enclosure. Uncontrolled humidity together with number of other factors including the presence of hygroscopic contamination resulting from the PCB A manufacturing process can introduce deviation from desired functionality or even intermittant or permanent failure of the device. Additional factors are the miniaturization and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in presence of water film formed due to humdity exposure and bias conditions on the PCBA surface. Aim of this paper is to provide an overview of the humidity driven reliability isues on electronics.