Editing Wafer testing (section)

==Wafer prober==
[[File:Wafer prober service configuration.jpg|thumb|right|350px|8-inch semiconductor wafer prober, shown with cover panels, tester and probe card elements removed. Wafer is visible on the left side.]]

Both WPT and WFT are performed using a wafer handler called a [[wafer prober]]. The wafer prober brings an array of microscopic needles or probes called a [[probe card]] into electrical contact with the wafer (vacuum-mounted on a wafer chuck). WPT and WFT use different probe cards, the WFT card contacts a chip's bond pads. After each test the prober moves the wafer to the next testing location. The wafer prober is responsible for loading and unloading the wafers from their carrier (or cassette) and is equipped with automatic pattern recognition optics capable of aligning the wafer with sufficient accuracy to ensure accurate registration between the [[contact pad]]s on the wafer and the tips of the probes.