Printed circuit boards shall absorb moisture to the point of equilibrium. This shall occur as long as there is a source of moisture. Relative humidity provides an ample source of moisture for the absorption process. It is common for contract manufacturers to maintain a controlled environment that often relies on humidity to minimize static charge build up. Electro-static discharge (ESD) is damaging to assembled electronic components. Humidifiers are employed to maintain a 50% relative humidity environment. However, in minimizing one problem another is introduced. The humidity that is introduced to minimize ESD is absorbed into the printed circuit board and components alike.
In a production setting on a manufacturing shop floor, (more…)