An analysis of tungsten probes´ effect on yield in a production wafer probe environment

The authors summarize experiments performed to establish prove card maintenance techniques and standards. These techniques are designed to improve the probe´s contact quality when testing dice on wafers in production testing and are based on two concepts: probe contact resistance and probe mark quality. The results indicate that the best material to use is sanding paper in a circular movement with a minimum of pressure applied to the probes. This pressure should gradually increase during the sanding operation. Ceramic material is not recommended for probe maintenance because of the resulting poor probe marks. Contact resistance measurements should be performed using the same metallized surface used for production wafers. If it is necessary to exercise the probe card, it should be done before the sanding operation. The sanding should always be the last operation before solvent cleaning