Stable contact requires clean probe tips, correct overdrive, accurate planarity, controlled force, and repeatable wafer positioning. Trend data can reveal degradation before it becomes a yield event.
Intermittent contact, excessive resistance, pad damage, alignment drift, and temperature instability can create false results. Troubleshooting should separate probe-card, prober, tester, wafer, and recipe causes.
A typical flow includes wafer alignment, touchdown, parametric and functional tests, binning, map review, and data transfer. Yield, contact resistance, retest rate, throughput, and false-fail rate are key metrics.
Wafer probe testing makes temporary electrical contact to each die before packaging. It screens defects early, supports wafer maps, and provides data for process control and final-test planning.