I can't remember the resistivity of the water thats typically
required, but a common practice is to use very pure, high
resistivity water, then use a CO2 bubbler to reduce resistivity
to a point where ESD to the wafer isn't a risk. The water jets
aimed at the cutting area can generate large electrostatic
charges. The dissolved CO2 reduces them to acceptable levels.









         The high purity of the water before CO2 gets rid of the nasty
         stuff like Na+, Cl- etc.

         J Drake
         Celestica Ltd.