The big screen

The methods of chip testing, including screening and statistical techniques to find out the duds on a wafer, are discussed. Screening is a method to find out the chips that are likely to fail based on measurements, such as power consumption. The method involves discarding some suspects without conclusive evidence that they will fail in operation. An advantage of large number of test measurements to detect outliers and suspect parts is that it does not age the part in the way that accelerated life-testing testing techniques such as burn-in do. There is an important distinction between binning a die based on its neighborhood, which use no information from the die, and with statistical post-processing, which use information from the die itself. The adaptive testing improves the ability of screening by linking the causes of failures to oddities in the way that a chip responds to certain tests.