Probing systems are used for wafer probing in order to test the dies on a wafer as a failure analysis technique. The process is done automatically, holding the wafer on a platform and dropping a set of precision point needles onto pre-assigned probe pads on the given die. Using special interfacing software, the probe system is connected to automatic test equipment so that it can carry out electrical testing.

When the probe needles are dropped, electrical contact is made. They provide the electrical conductors needed for the die to be tested correctly. Each needle is held by a micromanipulator controlled by an analyst, which allows the needle to land on the die with accuracy and precision. Probing is done to see that the wafer has no problems that may result in low electrical yields after the wafer has been assembled into units. This saves costs for assembly and further testing.

Probing is not thought to be as efficient as electrical testing, but it must be done in order to check whether the dice are functional or meeting their critical electrical parameters. Voltage and current measurements are performed by an electrical measurement instrument attached to the probe needle through the micro manipulator in order to receive the desired information. Instruments like voltmeters and curve tracers are often attached to the probe station. Circuit excitation may also be supplied for the die circuit in this same way, whether from voltage supplies, waveform generators, or more.

A good system is able to map the failing dice and relate the position of the die on a wafer to failure modes observed. Probing systems tend to be fairly expensive, as they must be very specific, so it is usually dispensed for mature and stable products that are able to meet yield expectations despite blind assembly.