Behaviour of Moisture Sensitive Devices

Humidity is an essential and integral part of human life, of which electrical equipment and devices are already an integral part. The moisture problem is mainly associated with components in non-hermetic plastic packages. Understanding the behavior of these components is a basic prerequisite for proper handling during the manufacturing process. By proper handling of the components, various moisture-related defects can be avoided. For these reasons, moisture sensitive devices (MSD) are divided into different moisture sensitivity levels (MSL), which indicate their floor life. The main danger associated with moisture does not lie in its absorption itself, but in the mechanical stress caused by the rapid expansion of the evaporated water in a relatively short time during the reflow soldering process. Defects associated with delamination and cracks of the component packages are one of the most common defects in surface mounting technology. If the absorbed moisture does not cause mechanical defects during production within the Surface Mount Technology (SMT), it can further accelerate the degradation phenomena of the device. The results of this work clearly show that components exposed to environments with higher relative humidity (RH) absorb more moisture than the same components at lower RH. By reducing RH, the risk associated with defects caused by mishandling MSDs can also be reduced.