Non contact wafer testing is an alternative to mechanical probing of ICs during the wafer testing step in semiconductor device fabrication.
A certain amount of over-travel is required after the first probe makes contact with the wafer, for two reasons: There are numerous types of mechanical probes available commercially: their shape can be in the form of a cantilever, spring, or membrane, and they can be bent into shape, stamped, or made by microelectromechanical systems processing.
Using mechanical probes has certain drawbacks: Alternatives to mechanical probing of ICs have been explored by various groups (Slupsky,[4] Moore,[5] Scanimetrics,[6] Kuroda[7]).
These methods use tiny RF antennae (similar to RFID tags, but on a much smaller scale) to replace both the mechanical probes and the metal probe pads.
If the antennae on the probe card and IC are properly aligned, then a transmitter on the probe card can send data wirelessly to the receiver on the IC via RF communication.