MSD Protection Steps Per J-STD-033B.1
As packages get smaller, the risk for damage to moisture-sensitive devices increases. With the higher temperatures required for Pb-free soldering, that risk is further compounded. That’s why it’s extremely important to be aware and vigilant of MSDs.
ICs can act like a sponge. If they have semi-permeable membranes, moisture from the ambient air can get into those devices. When they get rapidly heated during reflow or rework, the result is rapid outgassing. In some cases, this excessive outgassing causes popcorning, which can damage the internal structures of a component.