Ultrasonic Vibration Drilling of Microholes in Glass

Microholes with a diameter of 10 μm were drilled in glass by ultrasonic vibration cutting using a microtool fabricated by wire electrodischarge grinding. The workpiece was vibrated in order to realize high-precision tool rotation. Cutting was performed in the ductile regime at a depth of cut of 0.05 μm, leaving neither fractures nor cracks around the rim of the hole. The application of ultrasonic vibrations resulted in (1) a decrease in the required cutting force, (2) an extension of the tool life, (3) an increase in the permissible penetration and tool length and (4) smoother machined surfaces.