Glossary Table V
| Vapor Phase Soldering: Process in which an electrically non-conducting liquid is heated to its boiling temperature, creating a chemically inert vapor phase. Soldering begins when a printed circuit board is brought in contact with the vapor. The vapor condenses on the surface of the board and continues until the board reaches the temperature of the vapor. The solder paste liquefies due to its melting temperature being below that of the vapor phase. The warming of the board with vapor provides a completely oxidation-free melting point. The boiling point of the liquid determines the soldering temperature. |
| Very Fine Pitch (VFP): Center-to-center lead distance of surface mount packages that are between 0.012 and 0.020 inches. |
| Via: A plated-through hole used for interconnection of conductors on different sides or layers of a PCB. |
| Vision: One or more cameras used to center SMT components for accurate placement on a printed circuit board. |
| Voids: Cavities inside solder joints formed by gases that are released during reflow or by flux residues that fail to escape from the solder before it solidifies. |