Circuit cards are being assembled using moisture sensitive devices. MSD
s are components that are encapsulated with a moisture permeable material (typically an epoxy material). Because the epoxy material is permeable, these devices are classified as moisture sensitive, which simply means that they absorb moisture after they are opened from their sealed packaging, and the amount of moisture absorbed increases with time. To avoid component damage
or possible field failure caused by moisture expansion and cracking during the reflow soldering process, the moisture content in these components must be tracked and controlled. Typically that can be accomplished using a manual process. However, that is susceptible to human error. Raytheon determined that an automated tracking and control system was needed.