Moisture trapped within components and PBs presents a serious problem during the fabrication and assembly process. Too much moisture can lead to board failures when it is turned to steam during the reflow process. When the moisture is heated, the resulting pressure can cause packages to erupt and damage lead-frames and wire-bonded connections. This damage can be in the outer surface of the component and be visible, or within an inner layer of a multi-layer PB and be hidden. Regardless of the location, the result is the same, a defective and unusable product.