vacuum pickup A parts-handling instrument through which a vacuum force secures and holds them for placement.
vapour phase A mass soldering technique in which high-temperature vapour, condensing on the solder joints of a PCB, is the heat-transfer medium.
vapour phase (reflow) See condensation soldering.
vector photoplotter (also ‘vector plotter’, or ‘Gerber photoplotter’ after Gerber Scientific Co., which built the first commercial equipment). A CAD database is plotted on photographic film in a darkroom by drawing each line with a continuous lamp shining through an annular-ring aperture, and creating each pad by flashing the lamp through a specially sized and shaped aperture. These ‘apertures’ are thin trapezoidal pieces of plastic which are mostly opaque, but with a transparent portion that controls the size and shape of the light pattern. The apertures are mounted on an ‘aperture wheel’ which can hold up to 24 apertures. Laser photoplotters are faster and have largely replaced the vector photoplotter, except for making very large photoplots
vehicle As used when referring to fluxes and solder paste, the ‘vehicle’ is a thermally stable material that acts as a high temperature solvent during wave soldering. Sometimes it is also a weak activator. Depending on its properties, it can inhibit or induce corrosion.
via (hole) A plated-through hole used to connect two or more conductor layers of a multilayer board, in which there is no intention to insert a component lead or other reinforcing material. See through-hole via, blind via, tented via and buried via.
via tenting Covering a via with a masking material, such as a dry film polymer coating (solder mask), B-stage (prepreg), etc., in order to prevent hole access by process solutions, solder, or contamination.
void The absence of material in a localised area.
voltage breakdown The level of voltage potential across a normally nonconductive material where current begins to flow in the material or on its surface. This may be accompanied by a sudden electrostatic discharge, which can severely damage the material.
