Wafer probe process verification tools

We present some tools we have developed that ensure the good quality of the wafer probing, or wafer test, process. Most of the problems at Wafer Probe appear in the same way and by detecting their pattern, even not knowing the exact source of the problem, we can prevent the product and its yield from being affected. The most common patterns of failures are: A certain category failing consecutively, a certain test failing above statistical limits expected, based on the historical results of that product, same wafers yielding different in two different testers, and results in a lot going worse wafer by wafer. For addressing these issues, we have generated a set of programs that are run at the end of every wafer tested, in real time, and that generate alarms and tell actions to the operator when the above problems are detected.