Probe Card Ground Noise Canceling Circuit

During wafer testing with probe cards in Automatic Test Equipment (ATE), it is challenging to maintain a stable VDD-GND voltage supplied to the Device Under Test (DUT) due to fluctuations in GND voltage caused by the return current from the DUT. Typically, due to a lack of channels, the test equipment reads and corrects the VDD voltage based on the representative GND voltage at an intermediate point where power is supplied, rather than the ground of each DUT. As a result, if there is a change in the GND voltage of each DUT, the test equipment is unable to detect and adjust for it. To overcome these limitations, this study proposes a method of configuring a circuit within the probe card that allows for the use of existing equipment functions such as current measurement and open-short testing while correcting changes in the individual DUT GND voltage of sensitive power sources. This approach aims to minimize wrong defect determination caused by changes in GND voltage during wafer testing.