US Patent 7585201 Water jet processing method

In a water jet processing method, when a nozzle adapted to emit water jet is moved relatively to a substrate to form a second cut line intersecting a first cut line, the relative travel speed of the nozzle is set to a second speed lower than a first normal speed by about 1/5 to 1/20 at least in a section anteroposterior to the intersection. Delay-inclination of a front edge of the second cut line is eliminated as much as possible to thereby prevent the occurrence of an insufficient processing area.